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Sample records for ligand-modified micellar-enhanced ultrafiltration

  1. Use of ligand-modified micellar-enhanced ultrafiltration to selectively separate copper ions from wastewater streams

    SciTech Connect

    Shadizadeh, S.B.

    1992-12-31

    The selective removal of target ions from an aqueous solution containing ions of like charge by ligand-modified micellar-enhanced ultrafiltration (LM-MEUF), is presented. In LM-MEUF, surfactant and specially tailored ligand are added to the contaminated stream. The surfactant forms aggregates called micelles, the hydrocarbon core of which the ligand complexed with the target species will solubilize. The surfactant is chosen to have the same charge type as the target ion; therefore, other ions (with similar charge) will not associate with the micelle, which makes the separation of the target ion selective. The solution is then processed by ultrafiltration, using a membrane with pore size small enough to block the passage of the micelles. In this study the divalent copper is the target ion in the solution containing divalent calcium. The surfactant is cetylpyridinium chloride (CPC) and the ligand is 4-hexadecyloxybenzyliminodiacetic acid (C{sub 16}BIDA). Experiments were conducted with batch stirred cells and the results have been compared to separation that take place under a variety of conditions in the LM-MEUF process. Rejections of copper of up to 99.8% are observed, with almost no rejection of calcium, showing that LM-MEUF has excellent selectivity and separation efficiency.

  2. An equilibrium model for ligand-modified micellar-enhanced ultrafiltration. Selective separation of metal ions using iminoacetic substituted polyamines and a theoretical model for the titration behavior of polyamines

    SciTech Connect

    Dharmawardana, Udeni Rajaratna

    1992-01-01

    This thesis consists of three chapters. Chapter 1, An equilibrium model for ligand-modified micellar-enhanced ultrafiltration, describes a theoretical model and experimental investigations which used the semi-equilibrium-dialysis method with N-n-dodecyl iminodiacetic acid as the ligand. In Chapter 2, Selective separation of metal ions using iminoacetic substituted polyamines, polyamines with a substituted ligand group are synthesized and used in investigating selective separation of copper ions from aqueous solution. In Chapter 3, A theoretical model for the titration behavior of polyamines, a novel approach to explain the titration behavior of polymeric amines based on the binding behavior of counterions is described. The application of this study is to the investigation of inexpensive and efficient methods of industrial waste water treatment.

  3. Produced water treatment by micellar-enhanced ultrafiltration.

    PubMed

    Deriszadeh, Ali; Husein, Maen M; Harding, Thomas G

    2010-03-01

    A water treatment approach combining ultrafiltration (UF) and micellar-enhanced ultrafiltration (MEUF) techniques was used for the removal of organic contaminants in field produced water samples from Canada and the United States. Free oil droplets and suspended solids were separated by initial UF treatments while MEUF was necessary for the removal of dissolved organics. It was shown that the amphiphilic characteristics of some organics commonly existing in produced water contributed to lowering the critical micelle concentration (CMC) of the surfactant employed. Lower surfactant concentrations could, therefore, be employed leading to lower fouling and back contamination and higher permeate flux. In addition, the incorporation of organic contaminants into the structure of cetylpyridinium chloride (CPC) micelles resulted in larger size and higher dissolution capacity of the "mixed micelles". The performance of polymeric and ceramic membranes of different molecular weight cutoffs (MWCOs) was evaluated by analyzing the permeate flux, recovery ratio, and solute percent rejection as functions of trans-membrane pressure (TMP). A mathematical model based on Darcy's law and the resistance in-series model successfully described the flux decline as a function of TMP for the two field samples and the two membranes studied.

  4. Removal characteristics of anionic metals by micellar-enhanced ultrafiltration.

    PubMed

    Baek, Kitae; Kim, Bo-Kyong; Cho, Hyun-Jeong; Yang, Ji-Won

    2003-05-30

    Surfactant-based separation of Fe(CN)(6)(3-) and CrO(4)(2-) using regenerated cellulose membrane was studied in order to assess the potential of micellar-enhanced ultrafiltration for the remediation of wastewater or groundwater polluted with ferriccyanide and chromate. In the ferriccyanide/octadecylamine acetate (ODA) and chromate/ODA systems, removal of ferriccyanide increased from 73 to 92% and to 98%, and that of chromate from 64 to 97% and to >99.9% as the molar ratio of ODA to ferriccyanide and to chromate increased from 1 to 2 and to 3, respectively. In the ferriccyanide/chromate/ODA system, while the removal of ferriccyanide increased from 62 to 72% and to 93%, the removal of chromate from 20 to 38% and to 68% as the molar ratio of ferriccyanide:chromate:ODA increased from 1:1:1 to 1:1:2 and to 1:1:4, respectively. With the molar ratio of 1:1:6, the removal was >99.9 and 98% for chromate and ferriccyanide, respectively. Ferriccyanide ions were more easily bound to ODA micelles because the binding power of ferriccyanide was greater than that of chromate.

  5. Removal of phenol from synthetic waste water using Gemini micellar-enhanced ultrafiltration (GMEUF).

    PubMed

    Zhang, Wenxiang; Huang, Guohe; Wei, Jia; Li, Huiqin; Zheng, Rubing; Zhou, Ya

    2012-10-15

    Comprehensive studies were conducted on the phenol wastewater ultrafiltration (UF) with the help of various concentrations of cationic Gemini surfactant (N1-dodecyl-N1,N1,N2,N2-tetramethyl-N2-octylethane-1,2-diaminium bromide, CG), conventional cationic surfactant (dodecyl trimethyl ammonium bromide, DTAB), anionic surfactant (sodium dodecyl sulfate, SDS) and nonionic surfactant ((dodecyloxy)polyethoxyethanol, Brij35). A flat sheet module with polyethersulfone (PES) membrane was employed in this investigation. The effects of feed concentration (phenol and surfactant) on the retention of phenol and surfactant, permeate flux and membrane fouling by micelles were evaluated. The distribution coefficient (D), the loading of the micelles (L(m)) and the equilibrium distribution constant (K) were also utilized to estimate the micellar-enhanced ultrafiltration ability for phenol. Scanning electron microscope (SEM), Fourier transform infrared spectrometer with attenuated total reflectance accessory (ATR-FTIR) and mercury porosimeter were applied to analyze membrane surface morphology, membrane material characteristics and membrane fouling for the original and fouled membranes. Based on the above analysis, the performance of the selected Gemini surfactant was proved superior in the following aspects: retention of phenol/surfactant (peak value is 95.8% for phenol retention), permeate flux and membrane fouling with respect to other conventional surfactants possessing equal alkyl chain length. These results demonstrated that CG surfactant with exceptional structure has favorable prospects in the treatment of phenol wastewater by the micellar-enhanced ultrafiltration.

  6. Micellar-enhanced ultrafiltration membrane (MEUF) of Batik wastewater using Cetylpyridinium chloride surfactant

    NASA Astrophysics Data System (ADS)

    Aryanti, Nita; Pramudono, Bambang; Prawira, Christ Nadya P.; Renardi, Rheza; Fatikhatul K. Ika, S.

    2015-12-01

    In batik production, reactive dyes such as remazol, indigosol, naphtol and rapid are used in the dying process. Batik wastewater contains high level of reactive dyes, wax and sodium salts and is characterized with high Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) as well as high concentration of phenol and Ammonia. Micellar-Enhanced Ultrafiltration Membrane (MEUF) is one of promising technology to separate low molecular weight substances such as dyes. The MEUF process involves combination of ultrafiltration membrane and surfactant at concentration higher than surfactant's Critical Micelle Concentration (CMC). This technique combines high selectivity of reverse osmosis membrane and high flux of ultrafiltration membrane but with lower pressure. Ultrafiltration of batik waste water without surfactant (UF) and with addition of surfactant (MEUF) were studied in order to compare the performance of both systems. The Batik wastewater were obtained from batik industry in Semarang and Surakarta, Central Java, Indonesia. Cetyl Pyridinium Chloride at concentration of 2 and 4 times of its CMC were used. Flatsheet ultrafiltration membrane was made from Polyethersulphone (12% w/w), N-methyl Pyrrolidone (83% w/w) and Polyethylene Glycol (5% w/w). The performance of the UF and MEUF were evaluated based on flux profiles and rejections (COD, TSS, concentration of Ammonia). The results showed that the MEUF had superior performance than the UF. Concentration of COD, TSS, phenol and ammonia were reduced significantly. The rejection of COD were 92.74% and 94.15%. Moreover, the MEUF was capable to reduce the TSS with the rejection of 86.26% and 65%. The concentration of ammonia in permeate were 0.43 ppm and below 0.01 ppm.

  7. Micellar-enhanced ultrafiltration and air stripping for surfactant-contaminant separation and surfactant reuse

    SciTech Connect

    Lipe, K.M.; Sabatini, D.A.; Hasegawa, M.A.; Harwell, J.H.

    1996-05-01

    Micellar-enhanced ultrafiltration (MEUF) and air stripping were evaluated for surfactant-contaminant separation and surfactant recovery. Two linear alkyl diphenyloxide disulfonate (DPDS) surfactants were evaluated with the contaminants naphthalene and trichloroethylene. A separation model developed from micellar partitioning principles showed a good correlation to batch MEUF studies, whereas flux analysis highlighted concentration polarization effects in relation to hydrophobe length. MEUF effectively concentrated the surfactant-contaminant system (93 to 99% retention); however, this did not result in surfactant-contaminant separation. Batch and continuous flow air stripping models were developed based upon air/water ratio, surfactant concentration, and micellar partitioning; model predictions were validated by experimental data. Sensitivity analyses illustrated the decline in contaminant-surfactant separation with increasing surfactant concentration (e.g., TCE removal efficiency declines from 83% to 37% as C-16 DPDS concentration increases from 0 to 55 mM). This effect is greater for more hydrophobic contaminants (naphthalene vs. TCE) and surfactants with greater solubilization potential (C16-DPDS vs. C-12 DPDS). The resulting design equations can account for this effect and thus properly size air strippers to achieve the desired removal efficiency in the presence of surfactant micelles. Proper selection and design of surfactant-contaminant separation and surfactant recovery systems are integral to optimizing surfactant-enhanced subsurface remediation.

  8. Removal of arsenic from groundwater by micellar-enhanced ultrafiltration (MEUF).

    PubMed

    Iqbal, Javed; Kim, Ho-Jeong; Yang, Jung-Seok; Baek, Kitae; Yang, Ji-Won

    2007-01-01

    The removal characteristics of arsenate using micellar-enhanced ultrafiltration (MEUF) were investigated. Among four different cationic surfactants used, hexadecylpyridinium chloride (CPC) showed the highest removal efficiency of arsenic (96%), and the removal efficiency with hexadecyltrimethylammonium bromide (CTAB) was 94%. But the removal efficiency with benzalkonium chloride (BC) was the lowest (57%) due to higher critical micelle concentration (CMC) of BC than those of other surfactants. Over 80% of arsenic was removed with octadecylamine acetate (ODA). On the effect of solution pH on the arsenic removal, since the valance of arsenate decreases from trivalent to monovalent as pH decreases, the removal was reduced at lower pH. The presence of 0.45mM of nitrate and 0.01mM of phosphate reduced the removal efficiency by 5-8%. This decrease was because of the competition between the arsenate, nitrate and phosphate for the binding sites of the surfactant micelle. Similar decrease in the removal of arsenate was observed with CPC, CTAB and ODA in the presence of these anions. In cross-flow filtration, the removal efficiency of arsenic was similar to that in the dead-end system. However, the decline in flux was less than that in dead-end filtration. In order to lower the concentration of the surfactant in the effluent, the effluent was treated with powdered activated carbon (PAC) before discharging to the environment. Over 98% surfactant was removed with 1gl(-1) of PAC. In conclusions, the MEUF is considered as a feasible process using CPC or CTAB to remove the arsenate from groundwater compared with the other solid based adsorbent processes.

  9. Micellar-enhanced ultrafiltration of copper ions using sodium dodecyl sulfate and its mixture with Brij 35, Tween 80 and Triton X-100.

    PubMed

    Zhao, Baowei; Li, Ruirui; Zhong, Jinkui; Zhang, Li

    2013-01-01

    The performance of copper ion removal using sodium dodecyl sulfate (SDS) and its mixtures with Brij 35, Tween 80 (TW80) and Triton X-100 (TX100) by micellar-enhanced ultrafiltration (MEUF) was investigated. The effects of the molar ratio of nonionic surfactant to SDS on the critical micelle concentration (CMC) of SDS/Brij 35, SDS/TW80 and SDS/TX100, the removal efficiency of Cu(2+), the residual concentration of SDS in the permeate solution and the permeate flux were tested. The results showed that the CMCs of the mixed surfactants were sharply less than that of pure SDS. The removal efficiencies of Cu(2+) were up to the maximum values 98.3 and 95.8% when the molar ratios of Brij 35 and TW80 to SDS were 0.3, and it was 93.5% given 0.7 molar ratio of TX100 to SDS. The concentration of SDS in the permeate decreased dramatically with the addition of nonionic surfactant, and the permeate flux decreased slightly as the molar ratio increased. Compared with the performance by single SDS, the mixed SDS/Brij 35, SDS/TW80 and SDS/TX100 at an optimum composition could result in not only higher rejection of Cu(2+) but also much less dosage of surfactant and concentration of SDS in the permeate.

  10. Removal of Radioactive Cations and Anions from Polluted Water using Ligand-Modified Colloid-Enhanced Ultrafiltration

    SciTech Connect

    Dr. John F. Scamehorn; Dr. Richard W. Taylor; Dr. Cynthia E. Palmer

    2001-12-17

    The purpose of this project was to develop, optimize, and evaluate new separation methods for removal of hazardous (radionuclides and toxic non-radioactive contaminants) metal ions from either ground water or aqueous waste solutions produced during Decontamination and Decommissioning operations at DOE sites. Separation and concentration of the target ions will result in a substantial reduction in the volume of material requiring disposal or long-term storage. The target metal ions studied were uranium, thorium, lead, cadmium, and mercury along with chromium (as chromate). The methods tested use membrane ultrafiltration in conjunction with water-soluble polymers or surfactants with added metal-selective chelating agents. Laboratory scale tests showed removal of 99.0-99.9% of each metal tested in a single separation stage. The methods developed for selective removal of radionuclides (UO22+, Th4+) and toxic heavy metals (Pb2+, Cd2+, Hg2+) are applicable to two DOE focus areas; decontamination of sites and equipment, and in remediation of contaminated groundwater. Colloid-enhanced ultrafiltration methods have potential to be substantially less expensive than alternative methods and can result in less waste. Results of studies with varying solution composition (concentration, acidity) and filtration parameters (pressure, flow rate) have increased our understanding of the fundamental processes that control the metal ion separation and colloid recovery steps of the overall process. Further laboratory studies are needed to improve the ligand/colloid recovery step and field demonstration of the technology is needed to prove the applicability of the integrated process. A number of graduate students, post-doctoral associates, and research associates have received training and research experience in the areas of separation science, colloid chemistry, and metal ion coordination chemistry of radionuclides and toxic metals. These scientists, some with positions in industry and

  11. A study of colloid-enhanced ultrafiltration. Final report, March 1984--December 1993

    SciTech Connect

    Scamehorn, J.F.; Christian, S.D.

    1994-02-01

    Over the past nine years of funding by DOE Office of Basic Energy Sciences, the authors have developed a whole family of methods under the umbrella of colloid-enhanced ultrafiltration techniques. These methods can be used for removal of either dissolved organics or multivalent ions from water or both simultaneously. They have gone from very fundamental studies of the ultrafiltration process to a field test using actual polluted groundwater. The orientation of this research has been the ultimate development of a workable, economical process. To do this, the authors have tried to understand the underlying fundamental phenomena involved in the separation and in potential solutions to technological bottlenecks and developed new scientific knowledge in the process. However, the thrust of the investigations have been focused on bringing the technology to a successful adoption by industry. This report summarizes the following: micellar-enhanced ultrafiltration; polyelectrolyte-enhanced ultrafiltration; ion-expulsion ultrafiltration; ligand-modified micellar-enhanced ultrafiltration; polyelectrolyte/surfactant-enhanced ultrafiltration, supporting research, and relation to energy. 61 refs.

  12. Online naphazoline quality control by micellar-enhanced spectrofluorimetry.

    PubMed

    Peralta, Cecilia Mariana; Silva, Raúl Alejandro; Fernández, Liliana Patricia; Masi, Adriana Noemí

    2011-01-01

    The aim of this study was to develop a method for online spectrofluorimetric quality control of naphazoline (NPZ) in pharmaceuticals and raw drugs. A combination of a flow-injection analysis (FIA) system with micellar-enhanced fluorescence detection is presented as a powerful alternative for the rapid and sensitive analysis of naphazoline. Since NPZ shows low native fluorescence, the use of an anionic surfactant, such as sodium dodecyl sulphate (SDS), provides a considerable enhancement of fluorescence intensity and the nature of the technique allows a possible and easy adaptation to a FIA system. Using λ(exc) = 280 nm and λ(em) = 326 nm, a good linear relationship (LOL) was obtained in the range 0.003-10 µg mL(-1) with a detection limit (LOD) of 3 × 10(-4) µg mL(-1) (s/n = 3). Parameters related to the nature of the analytical signal and to the FIA manifold were optimized. Satisfactory recoveries were obtained in the analysis of commercial pharmaceutical formulations. The proposed method is simple, accurate and allows for high-speed sampling and considerably shorter analysis times. In addition, it requires inexpensive equipment and reagents and has easy operational conditions and no side effects, thus avoiding environmental pollution through toxic waste. PMID:21538792

  13. Online naphazoline quality control by micellar-enhanced spectrofluorimetry.

    PubMed

    Peralta, Cecilia Mariana; Silva, Raúl Alejandro; Fernández, Liliana Patricia; Masi, Adriana Noemí

    2011-01-01

    The aim of this study was to develop a method for online spectrofluorimetric quality control of naphazoline (NPZ) in pharmaceuticals and raw drugs. A combination of a flow-injection analysis (FIA) system with micellar-enhanced fluorescence detection is presented as a powerful alternative for the rapid and sensitive analysis of naphazoline. Since NPZ shows low native fluorescence, the use of an anionic surfactant, such as sodium dodecyl sulphate (SDS), provides a considerable enhancement of fluorescence intensity and the nature of the technique allows a possible and easy adaptation to a FIA system. Using λ(exc) = 280 nm and λ(em) = 326 nm, a good linear relationship (LOL) was obtained in the range 0.003-10 µg mL(-1) with a detection limit (LOD) of 3 × 10(-4) µg mL(-1) (s/n = 3). Parameters related to the nature of the analytical signal and to the FIA manifold were optimized. Satisfactory recoveries were obtained in the analysis of commercial pharmaceutical formulations. The proposed method is simple, accurate and allows for high-speed sampling and considerably shorter analysis times. In addition, it requires inexpensive equipment and reagents and has easy operational conditions and no side effects, thus avoiding environmental pollution through toxic waste.

  14. Ultrafiltration of micellar solutions containing phenols

    SciTech Connect

    Adamczak, H.; Materna, K.; Urbanski, R.; Szymanowski, J.

    1999-10-15

    Micellar-enhanced ultrafiltration represents a potentially attractive tool for the removal of different contaminants from wastewaters. The ultrafiltration of micellar solutions containing phenol or 4-nitrophenol was studied. Sodium dodecyl sulfate (SDS), hexadecylrimethyl ammonium sulfate, alkyl polyglucoside Glucopon 215 SC UP, and oxyethylated methyl dodecanoates with the average degree of oxyethylation equal to 5 and 9 were used as surfactants and NaHCO{sub 3} as an electrolyte and alkalizing agent. Filtration and phenol rejection depends on the presence of NaHCO{sub 3} and the type of surfactant. NaHCO{sub 3} depresses to the filtration rate, especially in the case of SDS and hydrophobic oxyethylated methyl dodecanoate. The highest filtration rates are obtained for hexadecyltrimethyl ammonium bromide (CTAB) and alkyl polyglucoside micellar solutions. The best separations, both of phenol and 4-nitrophenol (almost 100% rejection), are obtained for CTAB micellar solutions at the pH range from 3 to 11. Nonionic surfactants are not effective enough for the separation of phenol and 4-nitrophenol. SDS solutions permit only the separation of phenol.

  15. Isothermic hemodialysis and ultrafiltration.

    PubMed

    Rosales, L M; Schneditz, D; Morris, A T; Rahmati, S; Levin, N W

    2000-08-01

    The increase in patient temperature during hemodialysis is explained by hemodynamic compensation during ultrafiltration and hypovolemia that leads to peripheral vasoconstriction and reduced heat losses. We analyzed 51 stable high-efficiency hemodialysis treatments in 27 patients during isothermic dialysis in which body temperature was maintained at a constant level (+/-0.1 degrees C) using the temperature-control option of the Blood Temperature Monitor (BTM; Fresenius Medical Care, Bad Homburg, Germany). Hemodialysis was delivered using ultrapure water (limulus amebocyte lysate test < 0. 06 endotoxin units/mL) at mean blood flows of 410 +/- 40 mL/min. During treatments lasting 178 +/- 23 minutes, 4.8% +/- 1.4% of postdialysis body weight (W%) and 9.5% +/- 2.5% of postdialysis body water were removed using mean ultrafiltration rates of 1.1 +/- 0.3 L/h. Dialysate temperatures significantly decreased from 35.9 degrees C +/- 0.3 degrees C to 35.6 degrees C +/- 0.6 degrees C during hemodialysis. During these treatments, 187 +/- 69 kJ of thermal energy were removed from the patients through the extracorporeal circulation using cool dialysate. Extracorporeal heat flow was 17 +/- 6 W. Energy expenditure (H) estimated from anthropometric data was 65 +/- 12 W. Thus, 28% +/- 10% of estimated energy expenditure (H%) was removed during isothermic dialysis. A highly significant correlation was observed between H% and W% (H% = -5.6 * W%; r(2) = 0.91; P < 0.0001). This result is in support of the volume hypothesis of intradialytic heat accumulation and provides a rule of thumb to estimate extracorporeal cooling requirements for isothermic dialysis. Approximately 6% of H must be removed through the extracorporeal circulation for each percent of ultrafiltration-induced body-weight change. The importance of body temperature control during hemodialysis increases with increased ultrafiltration requirements.

  16. Ligand modified nanoparticles increases cell uptake, alters endocytosis and elevates glioma distribution and internalization

    PubMed Central

    Gao, Huile; Yang, Zhi; Zhang, Shuang; Cao, Shijie; Shen, Shun; Pang, Zhiqing; Jiang, Xinguo

    2013-01-01

    Nanoparticles (NPs) were widely used in drugs/probes delivery for improved disease diagnosis and/or treatment. Targeted delivery to cancer cells is a highly attractive application of NPs. However, few studies have been performed on the targeting mechanisms of these ligand-modified delivery systems. Additional studies are needed to understand the transport of nanoparticles in the cancer site, the interactions between nanoparticles and cancer cells, the intracellular trafficking of nanoparticles within the cancer cells and the subcellular destiny and potential toxicity. Interleukin 13 (IL-13) peptide can specifically bind IL-13Rα2, a receptor that is highly expressed on glioma cells but is expressed at low levels on other normal cells. It was shown that the nanoparticels modification with the IL-13 peptide could improve glioma treatment by selectively increasing cellular uptake, facilitating cell internalization, altering the uptake pathway and increasing glioma localization. PMID:23982586

  17. Novel properties and potential applications of functional ligand-modified polyoxotitanate cages.

    PubMed

    Li, Ning; Matthews, Peter D; Luo, He-Kuan; Wright, Dominic S

    2016-09-28

    Functional ligand-modified polyoxotitanate (L-POT) cages of the general type [TixOy(OR)z(L)m] (OR = alkoxide, L = functional ligand) can be regarded as molecular fragments of surface-sensitized solid-state TiO2, and are of value as models for studying the interfacial charge and energy transfer between the bound functional ligands and a bulk semiconductor surface. These L-POTs have also had a marked impact in many other research fields, such as single-source precursors for TiO2 deposition, inorganic-organic hybrid material construction, photocatalysis, photoluminescence, asymmetric catalysis and gas adsorption. Their atomically well-defined structures provide the basis for the understanding of structure/property relationships and ultimately for the rational design of new cages targeting specific uses. This highlight focuses on recent advances in L-POTs research, with emphasis on their novel properties and potential applications. PMID:27332621

  18. Alkaline detergent recycling via ultrafiltration

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-06-01

    The metal finishing industry uses alkaline cleaners and detergents to remove oils and dirt from manufactured parts, often before they are painted or plated. The use of these cleaners has grown because environmental regulations are phasing out ozone depleting substances and placing restrictions on the use and disposal of many hazardous solvents. Lawrence Livermore National Laboratory is examining ultrafiltration as a cleaning approach that reclaims the cleaning solutions and minimizes wastes. The ultrafiltration membrane is made from sheets of polymerized organic film. The sheets are rolled onto a supporting frame and installed in a tube. Spent cleaning solution is pumped into a filter chamber and filtered through the membrane that captures oils and dirt and allows water and detergent to pass. The membrane is monitored and when pressure builds from oil and dirt, an automatic system cleans the surface to maintain solution flow and filtration quality. The results show that the ultrafiltration does not disturb the detergent concentration or alkalinity but removed almost all the oils and dirt leaving the solution in condition to be reused.

  19. Ultrafiltration of equine digital lamellar tissue.

    PubMed

    Underwood, Claire; Collins, Simon N; van Eps, Andrew W; Allavena, Rachel E; Medina-Torres, Carlos E; Pollitt, Christopher C

    2014-11-01

    There are no experimentally validated pharmacological means of preventing laminitis; however, locally acting pharmaceutical agents with the potential to prevent laminitis have been identified. Demonstrating therapeutic drug concentrations in lamellar tissue is essential for evaluating the efficacy of these agents. The aim of this study was to develop an experimental technique for repeatedly sampling lamellar interstitial fluid. A technique for placing ultrafiltration probes was developed in vitro using 15 cadaver limbs. Subsequently, lamellar ultrafiltration probes were placed in one forelimb in six living horses. Interstitial fluid was collected continuously from the probes as ultrafiltrate for 4 (n = 4) or 14 days (n = 2). The rate of ultrafiltrate collection was calculated every 12 h. Biochemical analyses were performed on ultrafiltrate collected on night 1 (12-24 h post-implantation) and night 4 (84-96 h post-implantation). Sections surrounding the probe and control tissue from the contralateral limb were harvested, stained with H&E and Masson's trichrome and scored based on the tissue response to the probe. Ultrafiltration probes were placed in the lamellar tissue in all six horses. Ultrafiltrate was collected from these probes at 55 (30-63) μL/h (median [interquartile range]). Fluid production decreased significantly with time from night 3 onwards (P < 0.05). There was no significant change in the constituents of the ultrafiltrate between nights 1 and 4 (P > 0.05). The technique was well tolerated. This study demonstrates that ultrafiltration can be used to sample equine digital lamellar interstitial fluid, and has potential for measuring lamellar drug levels. PMID:25439438

  20. Evaluation of Ultrafiltration for Spacecraft Water Reuse

    NASA Technical Reports Server (NTRS)

    Pickering, Karen D.; Wiesner, Mark R.

    2001-01-01

    Ultrafiltration is examined for use as the first stage of a primary treatment process for spacecraft wastewater. It is hypothesized that ultrafiltration can effectively serve as pretreatment for a reverse osmosis system, removing the majority of organic material in a spacecraft wastewater. However, it is believed that the interaction between the membrane material and the surfactant found in the wastewater will have a significant impact on the fouling of the ultrafiltration membrane. In this study, five different ultrafiltration membrane materials are examined for the filtration of wastewater typical of that expected to be produced onboard the International Space Station. Membranes are used in an unstirred batch cell. Flux, organic carbon rejection, and recovery from fouling are measured. The results of this evaluation will be used to select the most promising membranes for further study.

  1. 21 CFR 177.2910 - Ultra-filtration membranes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... up to 12 percent yttrium oxide (CAS Reg. No. 1314-36-9). (3) Ultra-filtration membranes that consist... up to 5 percent yttrium oxide (CAS Reg. No. 1314-36-9). (4) Ultrafiltration membranes that consist...

  2. 21 CFR 177.2910 - Ultra-filtration membranes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... up to 12 percent yttrium oxide (CAS Reg. No. 1314-36-9). (3) Ultra-filtration membranes that consist... up to 5 percent yttrium oxide (CAS Reg. No. 1314-36-9). (4) Ultrafiltration membranes that consist...

  3. 21 CFR 177.2910 - Ultra-filtration membranes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... up to 12 percent yttrium oxide (CAS Reg. No. 1314-36-9). (3) Ultra-filtration membranes that consist... up to 5 percent yttrium oxide (CAS Reg. No. 1314-36-9). (4) Ultrafiltration membranes that consist...

  4. Microfiltration and Ultrafiltration Membranes for Drinking Water

    EPA Science Inventory

    This article provides a concise and abbreviated summary of AWWA Manual of Practice M53, Microfiltration and Ultrafiltration Membranes for Drinking Water, to serve as a quick point of reference. For convenience, the article’s organization matches that of M53, as follows: • wate...

  5. Tangential Ultrafiltration of Aqueous "Saccharomyces Cerevisiae" Suspensions

    ERIC Educational Resources Information Center

    Silva, Carlos M.; Neves, Patricia S.; Da Silva, Francisco A.; Xavier, Ana M. R. B.; Eusebio, M. F. J.

    2008-01-01

    Experimental work on ultrafiltration is presented to illustrate the practical and theoretical principles of this separation technique. The laboratory exercise comprises experiments with pure water and with aqueous "Saccharomyces cerevisiae" (from commercial Baker's yeast) suspensions. With this work students detect the characteristic phenomena…

  6. Ligand-modified polyelectrolyte-enhanced ultrafiltration with electrostatic attachment of ligands. 2. Use of diethylenetriaminepentaacetic acid/cationic polyelectrolyte mixtures to remove both cations and anions from aqueous streams

    SciTech Connect

    Tuncay, M. Univ. of Oklahoma, Norman, OK ); Christian, S.D.; Tucker, E.E.; Taylor, R.W.; Scamehorn, J.F. )

    1994-12-01

    A mixture of a cationic polyelectrolyte, poly(diallyldimethylammonium chloride) or PDADMAC, and the anionic ligand diethylenetriaminepentaacetic acid (DTPA) can be added to aqueous streams as a water-soluble colloid to bind simultaneously divalent cations, such as Cu[sup 2+] and Pb[sup 2+], and anions, such as CrO[sub 4][sup 2[minus

  7. Development and Demonstration of Ultrafiltration Simulants

    SciTech Connect

    Russell, Renee L.; Billing, Justin M.; Peterson, Reid A.; Rinehart, Donald E.; Smith, Harry D.

    2009-02-24

    According to Bechtel National, Inc. (BNI) Test Specification 24590-PTF-TSP-RT-06-006, Rev 0, Simulant Development to Support the Development and Demonstration of Leaching and Ultrafiltration Pretreatment Processes,” simulants for boehmite, gibbsite, and filtration are to be developed that can be used in subsequent bench and integrated testing of the leaching/filtration processes for the waste treatment plant (WTP). These simulants will then be used to demonstrate the leaching process and to help refine processing conditions which may impact safety basis considerations (Smith 2006). This report documents the results of the filtration simulant development.

  8. Reverse osmosis and ultrafiltration solve separation problems

    SciTech Connect

    Gooding, C.H.

    1985-01-07

    Membrane separation is discussed and analyzed in this paper. The analysis reviews the basic principles, suggests approaches to design, and briefly discusses some of the membranes and equipment available. The potential for energy saving through the use of membrane separation is enormous compared with other separation techniques, particularly evaporation. The author describes the evaporative methods in some detail. The reverse osmosis system (RO) is also described. In lowerpressure ultrafiltration systems, the energy savings are greater using this option. RO may have advantages over evaporation in terms of product quality, and because RO is not a thermal process, it can be used to concentrate temperature-sensitive materials without loss of quality.

  9. From the Lindlar catalyst to supported ligand-modified palladium nanoparticles: selectivity patterns and accessibility constraints in the continuous-flow three-phase hydrogenation of acetylenic compounds.

    PubMed

    Vilé, Gianvito; Almora-Barrios, Neyvis; Mitchell, Sharon; López, Núria; Pérez-Ramírez, Javier

    2014-05-12

    Site modification and isolation through selective poisoning comprise an effective strategy to enhance the selectivity of palladium catalysts in the partial hydrogenation of triple bonds in acetylenic compounds. The recent emergence of supported hybrid materials matching the stereo- and chemoselectivity of the classical Lindlar catalyst holds promise to revolutionize palladium-catalyzed hydrogenations, and will benefit from an in-depth understanding of these new materials. In this work, we compare the performance of bare, lead-poisoned, and ligand-modified palladium catalysts in the hydrogenation of diverse alkynes. Catalytic tests, conducted in a continuous-flow three-phase reactor, coupled with theoretical calculations and characterization methods, enable elucidation of the structural origins of the observed selectivity patterns. Distinctions in the catalytic performance are correlated with the relative accessibility of the active site to the organic substrate, and with the adsorption configuration and strength, depending on the ensemble size and surface potentials. This explains the role of the ligand in the colloidally prepared catalysts in promoting superior performance in the hydrogenation of terminal and internal alkynes, and short-chain alkynols. In contrast, the greater accessibility of the active surface of the Pd-Pb alloy and the absence of polar groups are shown to be favorable in the conversion of alkynes containing long aliphatic chains and/or ketone groups. These findings provide detailed insights for the advanced design of supported nanostructured catalysts.

  10. Synthesis of liver-targeting dual-ligand modified GCGA/5-FU nanoparticles and their characteristics in vitro and in vivo.

    PubMed

    Cheng, Mingrong; Gao, Xiaoyan; Wang, Yong; Chen, Houxiang; He, Bing; Li, Yingchun; Han, Jiang; Zhang, Zhiping

    2013-01-01

    Nanoparticle drug delivery systems using polymers hold promise for clinical applications. We synthesized dual-ligand modified chitosan (GCGA) nanoparticles using lactic acid, glycyrrhetinic acid, and chitosan to target the liver in our previous studies. We then synthesized the GCGA/5-FU nanoparticles by conjugating 5-fluorouracil (5-FU) onto the GCGA nanomaterial, which had a mean particle size of 239.9 nm, a polydispersity index of 0.040, a zeta potential of +21.2 mV, and a drug loading of 3.90%. GCGA/5-FU nanoparticles had good slow release properties, and the release process could be divided into five phases: small burst release, gentle release, second burst release, steady release, and slow release. Inhibitory effects of GCGA/5-FU on tumor cells targeted the liver, and were time and dose dependent. GCGA nanoparticles significantly prolonged the efficacy of 5-FU on tumor cells, and alleviated the resistance of tumor cells to 5-FU. GCGA/5-FU nanoparticles were mostly concentrated in the liver, indicating that the GCGA nanoparticles were liver targeting. GCGA/5-FU nanoparticles significantly suppressed tumor growth in orthotopic liver transplantation mouse model, and improved mouse survival.

  11. Ultrafiltration. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-12-01

    The bibliography contains citations concerning ultrafiltration, the separation of colloids or fine solid materials by filtration through microporous or semi-permeable materials. Citations discuss the use of the ultrafiltration process for removing dissolved toxic metals from groundwater, production of food-grade protein, treating kraft black liquor from pulp and paper processing, decontamination of low-level radioactive waste water, desalination, and hemodialysis. Topics also include ultrafiltration equipment and membrane descriptions. Procedures for preventing fouling and the cleaning of the filtration materials and membranes are also presented. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  12. Ultrafiltration. (Latest citations from the NTIS Bibliographic database). Published Search

    SciTech Connect

    Not Available

    1993-12-01

    The bibliography contains citations concerning ultrafiltration, the separation of colloids or fine solid materials by filtration through microporous or semi-permeable materials. Citations discuss the use of the ultrafiltration process for removing dissolved toxic metals from groundwater, production of food-grade protein, treating kraft black liquor from pulp and paper processing, decontamination of low-level radioactive waste water, desalination, and hemodialysis. Topics also include ultrafiltration equipment and membrane descriptions. Procedures for preventing fouling and the cleaning of the filtration materials and membranes are also presented. (Contains a minimum of 116 citations and includes a subject term index and title list.)

  13. Ultrafiltration. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    Not Available

    1994-12-01

    The bibliography contains citations concerning ultrafiltration, the separation of colloids or fine solid materials by filtration through microporous or semi-permeable materials. Citations discuss the use of the ultrafiltration process for removing dissolved toxic metals from groundwater, production of food-grade protein, treating kraft black liquor from pulp and paper processing, decontamination of low-level radioactive waste water, desalination, and hemodialysis. Topics also include ultrafiltration equipment and membrane descriptions. Procedures for preventing fouling and the cleaning of the filtration materials and membranes are also presented. (Contains a minimum of 133 citations and includes a subject term index and title list.)

  14. Ultrafiltration. (Latest citations from the NTIS database). Published Search

    SciTech Connect

    Not Available

    1993-01-01

    The bibliography contains citations concerning ultrafiltration, the separation of colloids or fine solid materials by filtration through microporous or semi-permeable materials. Citations discuss the use of the ultrafiltration process for removing dissolved toxic metals from groundwater, production of food-grade protein, treating kraft black liquor from pulp and paper processing, decontamination of low-level radioactive waste water, desalination, and hemodialysis. Topics also include ultrafiltration equipment and membrane descriptions. Procedures for preventing fouling and the cleaning of the filtration materials and membranes are also presented. (Contains a minimum of 113 citations and includes a subject term index and title list.)

  15. An osmolyte-based micro-volume ultrafiltration technique.

    PubMed

    Ghosh, Raja

    2014-12-01

    This paper discusses a novel, simple, and inexpensive micro-volume ultrafiltration technique for protein concentration, desalting, buffer exchange, and size-based protein purification. The technique is suitable for processing protein samples in a high-throughput mode. It utilizes a combination of capillary action, and osmosis for drawing water and other permeable species from a micro-volume sample droplet applied on the surface of an ultrafiltration membrane. A macromolecule coated on the permeate side of the membrane functions as the osmolyte. The action of the osmolyte could, if required, be augmented by adding a supersorbent polymer layer over the osmolyte. The mildly hydrophobic surface of the polymeric ultrafiltration membrane used in this study minimized sample droplet spreading, thus making it easy to recover the retained material after separation, without sample interference and cross-contamination. High protein recoveries were observed in the micro-volume ultrafiltration experiments described in the paper. PMID:25284741

  16. Role of Diuretics and Ultrafiltration in Congestive Heart Failure

    PubMed Central

    Shchekochikhin, Dmitry; Al Ammary, Fawaz; Lindenfeld, JoAnn; Schrier, Robert

    2013-01-01

    Volume overload in heart failure (HF) results from neurohumoral activation causing renal sodium and water retention secondary to arterial underfilling. Volume overload not only causes signs and symptoms of congestion, but can impact myocardial remodeling and HF progression. Thus, treating congestion is a cornerstone of HF management. Loop diuretics are the most commonly used drugs in this setting. However, up to 30% of the patients with decompensated HF present with loop-diuretic resistance. A universally accepted definition of loop diuretic resistance, however, is lacking. Several approaches to treat diuretic-resistant HF are available, including addition of distal acting thiazide diuretics, natriuretic doses of mineralocorticoid receptor antagonists (MRAs), or vasoactive drugs. Slow continuous veno-venous ultrafiltration is another option. Ultrafiltration, if it is started early in the course of HF decompensation, may result in prominent decongestion and a reduction in re-hospitalization. On the other hand, ultrafiltration in HF patients with worsening renal function and volume overload after aggressive treatment with loop diuretics, failed to show benefit compared to a stepwise pharmacological approach, including diuretics and vasoactive drugs. Early detection of congested HF patients for ultrafiltration treatment might improve decongestion and reduce readmission. However, the best patient characteristics and best timing of ultrafiltration requires further evaluation in randomized controlled studies. PMID:24276318

  17. The Role of Ultrafiltration in Patients with Decompensated Heart Failure

    PubMed Central

    Kamath, Sandeep A.

    2011-01-01

    Congestion, due in large part to hypervolemia, is the primary driver of heart failure (HF) admissions. Relief of congestion has been traditionally achieved through the use of loop diuretics, but there is increasing concern that these agents, particularly at high doses, may be deleterious in the inpatient setting. In addition, patients with HF and the cardiorenal syndrome (CRS) have diminished response to loop diuretics, making these agents less effective at relieving congestion. Ultrafiltration, a mechanical volume removal strategy, has demonstrated promise in achieving safe and effective volume removal in patients with cardiorenal syndrome and diuretic refractoriness. This paper outlines the rationale for ultrafiltration in CRS and the available evidence regarding its use in patients with HF. At present, the utility of ultrafiltration is restricted to selected populations, but a greater understanding of how this technology impacts HF and CRS may expand its use. PMID:21151532

  18. Radiocarbon dating of VIRI bone samples using ultrafiltration

    NASA Astrophysics Data System (ADS)

    Minami, Masayo; Yamazaki, Kana; Omori, Takayuki; Nakamura, Toshio

    2013-01-01

    Ultrafiltration can effectively remove low-molecular-weight (LMW) contaminants from bone gelatin to extract high-molecular-weight (HMW) proteins that are derived from original bone collagen, though it cannot remove HMW collagen crosslinked with humic acids. Therefore, ultrafiltration is often used to obtain more accurate 14C dates of bones. However, ultrafiltration may introduce new contaminants to bone gelatins, mainly from ultrafilters used. To study the effects of ultrafiltration on 14C age, we analyzed the C/N ratio, δ13CPDB and δ15NAIR values, and 14C ages of acid-soluble bone collagen obtained by decalcification, gelatin extracted from acid-insoluble bone collagen, and the HMW gelatin and LMW fractions produced during ultrafiltration of the extracted gelatin. Bone samples from the Fifth International Radiocarbon Intercomparison (VIRI) were used: VIRI-E (mammoth), -F (horse), -G (human), and -I (whale). In this study, carbon and nitrogen content and gelatin yields were used to evaluate collagen preservation in the VIRI bone samples. Radiocarbon ages, δ13CPDB and δ15NAIR values of unfiltered and HMW gelatins were obtained and compared with the published consensus values. The LMW fraction was found to exhibit different values from those of the other fractions, indicating the possible presence of extraneous contamination. The Vivaspin™ 6 ultrafilters used in this study were analyzed and radiocarbon dated both before and after cleaning. We present evidence to suggest that LMW fraction contaminants could be derived from the ultrafilters rather than humic substances. Excessively long ultrafiltration time was suspected to have contaminated the bone samples with material from the ultrafilter, because those samples exhibited older 14C ages than did those filtered for shorter durations. The results in this study indicate that 14C ages of unfiltered gelatin extracted from well-preserved bones can be sufficiently accurate, and that care should be taken not to

  19. Thin Stillage Fractionation Using Ultrafiltration: Resistance in Series Model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fractionation of thin stillage using ultrafiltration was conducted to evaluate membranes as an alternative to evaporators in the ethanol industry. Two regenerated cellulose membranes with molecular weight cut offs of 10,000 and 100,000 kDa, respectively, were evaluated. Total solids (suspended and...

  20. 21 CFR 177.2910 - Ultra-filtration membranes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ultra-filtration membranes. 177.2910 Section 177.2910 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only as Components of Articles Intended for Repeated Use...

  1. Cross-flow Ultrafiltration Scaling Considerations

    SciTech Connect

    Duignan, M

    2006-04-10

    One legacy of the nuclear age is radioactive waste and it must be stabilized to be stored in a safe manner. An important part of the stabilization process is the separation of radioactive solids from the liquid wastes by cross-flow ultrafiltration. The performance of this technology with the wastes to be treated was unknown and, therefore, had to be obtained. However, before beginning a filter study the question of experimental scale had to be addressed. Of course, carrying out experiments using full-size equipment is always ideal, but rarely practical when dealing with plant size processes. Flow loops that will handle millions of liters of slurries, which are either highly caustic or acidic, with flow rates of 10,000 lpm make full-scale tests prohibitively expensive. Moreover, when the slurries happen to be radioactive such work is also very dangerous. All of these considerations lend themselves to investigations at smaller scales and in many situations can be treated with computational analyses. Unfortunately, as scale is reduced it becomes harder to provide prototypic results and the two and three phase multi-component mixtures challenge accurate computational results. To obtain accurate and representative filter results the use of two scales were chosen: (1) Small-scale--would allow the testing with actual radioactive waste samples and compare results with simulated wastes that were not radioactive. For this scale the feed tank held 6 liters of waste and it had a single cross-flow filter tube 0.61 m long. (2) Pilot-scale--would be restricted to use simulated non-radioactive wastes. At this larger scale the feed tank held 120 liters of waste and the filter unit was prototypic to the planned plant facility in pore size (0.1 micron), length (2.29 m), diameter (0.0127 m inside and 0.0159 m outside diameter), and being multi-tubed. The small-scale apparatus is convenient, easy to use, and can test both radioactive and non-radioactive wastes; therefore, there is a

  2. Phosphate balance in peritoneal dialysis patients: role of ultrafiltration.

    PubMed

    Granja, Carlos Andres; Juergensen, Peter; Finkelstein, Fredric O

    2009-01-01

    Current National Kidney Foundation's Disease Outcome Quality Initiative (K/DOQI) clinical practice guidelines for bone metabolism and disease in chronic kidney disease (CKD) recommend maintenance of serum phosphorus levels below 5.5 mg/dl. About 40% of patients maintained on chronic peritoneal dialysis (CPD) have phosphate levels above 5.5 mg%. The present study was designed to examine the relative contribution of ultrafiltration to phosphate removal in CPD patients. 24-hour dialysate collections were obtained in 28 CPD patients and the diffuse and ultrafiltration (UF) contributions to phosphate removal determined. 11% of phosphate removal was accounted for by UF. There was a highly significant correlation between UF rate and the % of phosphate removed by UF. The results of this study underscore the importance of individualizing the peritoneal dialysis prescription. PMID:19494614

  3. Concentration polarization model for hollow-fiber membrane ultrafiltration

    SciTech Connect

    Yeh, H.M. ); Cheng, T.W. )

    1994-02-01

    The concentration polarization model has been applied to analyze the permeate flux of hollow-fiber membrane ultrafiltration. Comparison of theoretical prediction with experimental data has been made under various transmembrane pressures, feed velocities, and solution concentrations. Both theoretical prediction and experimental results show that average permeate flux increases as transmembrane pressure or feed velocity increases, but decreases when solution concentration increases. 24 refs., 9 figs.

  4. Purification of densonucleosis virus by tangential flow ultrafiltration.

    PubMed

    Grzenia, David L; Carlson, Jonathan O; Czermak, Peter; Han, Binbing; Specht, Rachel K; Wickramasinghe, S Ranil

    2006-01-01

    Purification at commercial scale of viruses and virus vectors for gene therapy applications and viral vaccines is a major separations challenge. Tangential flow ultrafiltration has been developed for protein purification. Here tangential flow ultrafiltration of parvoviruses has been investigated. Because these virus particles are small (18-26 nm), removal of host cell proteins will be challenging. The results obtained here indicate that 30, 50, and 100 kDa membranes reject the virus particles, whereas 300 kDa membranes allow some virus particles to pass into the permeate. The decrease in permeate flux for the 300 kDa ultrafiltration membrane is much greater than for the 30, 50, and 100 kDa membranes, indicating possible entrapment of virus particle in the membrane pores. The permeate flux and level of protein rejection is strongly affected by the cell culture growth medium. The results indicate that when developing a new process, it is essential that the cell culture and purification operations be developed in parallel.

  5. Control of fouling formation in membrane ultrafiltration by ultrasound irradiation.

    PubMed

    Naddeo, Vincenzo; Belgiorno, Vincenzo; Borea, Laura; Secondes, Mona Freda N; Ballesteros, Florencio

    2015-01-01

    The increasing application of membrane filtration in water and wastewater treatment necessitates techniques to improve performance, especially in fouling control. Ultrasound is one promising technology for this purpose as cavitational effects facilitate continuous cleaning of the membrane. This research studied the ultrafiltration of lake water in systems with constant permeate flux under medium frequency (45 kHz) ultrasound irradiation. Fouling was investigated by monitoring transmembrane pressure (TMP) using continuous or intermittent ultrasound irradiation and dead-end or crossflow operation. Best performance was observed with continuous ultrasound irradiation in crossflow mode. Intermittent irradiation reduced the rate of TMP build-up but nevertheless allowed irreversible fouling to develop.

  6. Ultrafiltration treatment for liquid laundry wastes from nuclear power stations

    SciTech Connect

    Kichik, V.A.; Maslova, M.N.; Svittsov, A.A.; Kuleshov, N.F.

    1988-03-01

    The authors conduct a comprehensive analysis of the waste constituents--radioactive and organic--of the laundry water resulting from the on-site laundering and decontamination of clothing worn in nuclear power plants. The primary isotope contaminants consist of niobium and zirconium 95, manganese 54, cobalt 60, iron 59, and cesium 134 and 137. A variety of filter and adsorbent materials used in an ultrafiltration process are comparatively tested for their effectiveness in removing not only these isotopes but also the organic contaminants in the process of recycling the water. Those materials consist of copper hexacyanoferrate, polyacrylophosphonic acid, and several metal-polymer complexes.

  7. Accuracy assessment on the analysis of unbound drug in plasma by comparing traditional centrifugal ultrafiltration with hollow fiber centrifugal ultrafiltration and application in pharmacokinetic study.

    PubMed

    Zhang, Lin; Zhang, Zhi-Qing; Dong, Wei-Chong; Jing, Shao-Jun; Zhang, Jin-Feng; Jiang, Ye

    2013-11-29

    In present study, accuracy assessment on the analysis of unbound drug in plasma was made by comparing traditional centrifugal ultrafiltration (CF-UF) with hollow fiber centrifugal ultrafiltration (HFCF-UF). We used metformin (MET) as a model drug and studied the influence of centrifugal time, plasma condition and freeze-thaw circle times on the ultrafiltrate volume and related effect on the measurement of MET. Our results demonstrated that ultrafiltrate volume was a crucial factor which influenced measurement accuracy of unbound drug in plasma. For traditional CF-UF, the ultrafiltrate volume cannot be well-controlled due to a series of factors. Compared with traditional CF-UF, the ultrafiltrate volume by HFCF-UF can be easily controlled by the inner capacity of the U-shaped hollow fiber inserted into the sample under enough centrifugal force and centrifugal time, which contributes to a more accurate measurement. Moreover, the developed HFCF-UF method achieved a successful application in real plasma samples and exhibited several advantages including high precision, extremely low detection limit and perfect recovery. The HFCF-UF method offers the advantage of highly satisfactory performance in addition to being simple and fast in pretreatment, with these characteristics being consistent with the practicability requirements in current scientific research.

  8. Ultra-filtration measurement using CT imaging technology

    NASA Astrophysics Data System (ADS)

    Lu, Junfeng; Lu, Wenqiang

    2009-02-01

    As a functional unit in the hemodialysis process, dialyzer captured quite a few medical research interests since 1980s. In the design of dialyzer or in the ongoing hemodialysis process, to estimate the ultra-filtration amount of a dialyzer, the sideway loss of the running blood flow through hollow fibers or filtration channels should be measured. This further leads to the measurement of the blood flow inside the dialyzer. For this measurement, a non-invasive method is highly desired because of the high-dense bundled hollow fibers or packed channels inside the dialyzer. As non-invasive measurement tools, CT (Computed Tomography) technologies were widely used for tissue, bone, and cancerous clinical analyses etc …. Thus, in this paper, a CT system is adopted to predict the blood flow inside a hollow fiber dialyzer. In view of symmetric property of the hollow fiber dialyzer, the largest cutting plane that parallels to the cylindrical dialyzer was analyzed by the CT system dynamically. And then, a noninvasive image analysis method used to predict the ultra-filtration amount is proposed.

  9. Treatment of laundry wastewater using polyethersulfone/polyvinylpyrollidone ultrafiltration membranes.

    PubMed

    Sumisha, A; Arthanareeswaran, G; Lukka Thuyavan, Y; Ismail, A F; Chakraborty, S

    2015-11-01

    In this study, laundry wastewater filtration was studied using hydrophilic polyvinylpyrollidone (PVP) modified polyethersulfone (PES) ultrafiltration membranes. The performances of PES/PVP membranes were assessed using commercial PES membrane with 10kDa in ultrafiltration. Operating parameters The influence of transmembrane pressure (TMP) and stirring speed on laundry wastewater flux was investigated. A higher permeate flux of 55.2L/m(2)h was obtained for modified PES membrane with high concentration of PVP at TMP of 500kPa and 750rpm of stirring speed. The separation efficiencies of membranes were also studied with respect to chemical oxygen demand (COD), total dissolved solids (TDS), turbidity and conductivity. Results showed that PES membrane with 10% of PVP had higher permeate flux, flux recovery and less fouling when compared with other membranes. Higher COD and TDS rejection of 88% and 82% were also observed for modified membranes due to the improved surface property of membranes. This indicated that modified PES membranes are suitable for the treatment of surfactant, detergent and oil from laundry wastewater.

  10. Fractionation of proteins with two-sided electro-ultrafiltration.

    PubMed

    Käppler, Tobias; Posten, Clemens

    2007-03-10

    Downstream processing is a major challenge in bioprocess industry due to the high complexity of bio-suspensions itself, the low concentration of the product and the stress sensitivity of the valuable target molecules. A multitude of unit operations have to be joined together to achieve an acceptable purity and concentration of the product. Since each of the unit operations leads to a certain product loss, one important aim in downstream-research is the combination of different separation principles into one unit operation. In the current work a dead-end membrane process is combined with an electrophoresis operation. In the past this concept has proven successfully for the concentration of biopolymers. The present work shows that using different ultrafiltration membranes in a two-sided electro-filter apparatus with flushed electrodes brought significant enhancement of the protein fractionation process. Due to electrophoretic effects, the filtration velocity could be kept on a very high level for a long time, furthermore, the selectivity of a binary separation process carried out exemplarily for bovine serum albumin (BSA) and lysozyme (LZ) could be greatly increased; in the current case up to a value of more than 800. Thus the new two-sided electro-ultrafiltration technique achieves both high product purity and short separation times.

  11. Fluctuation of Ultrafiltration Coefficient of Hemodialysis Membrane During Reuse

    NASA Astrophysics Data System (ADS)

    Arif, Idam; Christin

    2010-12-01

    Hemodialysis treatment for patient with kidney failure is to regulate body fluid and to excrete waste products of metabolism. The patient blood and the dialyzing solution (dialysate) are flowed counter currently in a dialyzer to allow volume flux of fluid and diffusion of solutes from the blood to the dialysate through a semipermiable membrane. The volume flux of fluid depends on the hydrostatic and the osmotic pressure difference between the blood and the dialysate. It also depends on the membrane parameter that represents how the membrane allows the fluid and the solutes to move across as a result of the pressure difference, known as the ultrafiltration coefficient Kuf. The coefficient depends on the number and the radius of membrane pores for the movement of the fluids and the solutes across the membrane. The measured membrane ultrafiltration coefficient of reused dialyzer shows fluctuation between one uses to another without any significant trend of change. This indicates that the cleaning process carried out before reuse does not cause perfect removal of clots that happen in the previous use. Therefore the unblocked pores are forced to work hardly to obtain targeted volume flux in a certain time of treatment. This may increase the unblocked pore radius. Reuse is stopped when there is indication of blood leakage during the hemodialysis treatment.

  12. Concentrating membrane proteins using ultrafiltration without concentrating detergents.

    PubMed

    Feroz, Hasin; Vandervelden, Craig; Ikwuagwu, Bon; Ferlez, Bryan; Baker, Carol S; Lugar, Daniel J; Grzelakowski, Mariusz; Golbeck, John H; Zydney, Andrew L; Kumar, Manish

    2016-10-01

    Membrane proteins (MPs) are of rapidly growing interest in the design of pharmaceutical products, novel sensors, and synthetic membranes. Ultrafiltration (UF) using commercially available centrifugal concentrators is typically employed for laboratory-scale concentration of low-yield MPs, but its use is accompanied by a concomitant increase in concentration of detergent micelles. We present a detailed analysis of the hydrodynamic processes that control detergent passage during ultrafiltration of MPs and propose methods to optimize detergent passage during protein concentration in larger-scale membrane processes. Experiments were conducted using nonionic detergents, octyl-β-D glucoside (OG), and decyl-β-D maltoside (DM) with the bacterial water channel protein, Aquaporin Z (AqpZ) and the light driven chloride pump, halorhodopsin (HR), respectively. The observed sieving coefficient (So ), a measure of detergent passage, was evaluated in both stirred cell and centrifugal systems. So for DM and OG increased with increasing filtrate flux and decreasing shear rates in the stirred cell, that is, with increasing concentration polarization (CP). Similar effects were observed during filtration of MP-detergent (MPD) micelles. However, lower transmission was observed in the centrifugal system for both detergent and MPD systems. This is attributed to free convection-induced shear and hence reduced CP along the membrane surface during centrifugal UF. Thus to concentrate MPs without retention of detergent, design of UF systems that promote CP is required. Biotechnol. Bioeng. 2016;113: 2122-2130. © 2016 Wiley Periodicals, Inc. PMID:27563851

  13. Peritoneal ultrafiltration in patients with advanced decompensated heart failure.

    PubMed

    Iadarola, Gian Maria; Lusardi, Paola; La Milia, Vincenzo; Amici, Gianpaolo; Santarelli, Stefano; Virga, Giovambattista; Basile, Carlo; Bertoli, Silvio; Bonofiglio, Renzo; Del Rosso, Goffredo; Feriani, Mariano; Galli, Emilio; Gallieni, Maurizio; Gambaro, Giovanni; Sandrini, Massimo; Sisca, Sergio; Cancarini, Giovanni

    2013-01-01

    The aim of the Best Practice guidelines on peritoneal ultrafiltration (UF) in patients with treatment-resistant advanced decompensated heart failure (TR-AHDF) is to achieve a common approach to the management of decompensated heart failure in those situations in which all conventional treatment options have been unsuccessful, and to stimulate a closer cooperation between nephrologists and cardiologists. The standardization of the case series of different centers would allow a better definition of the results published in the literature, without which they are nothing more than anecdotes. TR-AHDF is characterized by the persistence of severe symptoms even when all possible pharmacological and surgical options have been exhausted. These patients are often treated with methods that allow extracorporeal UF - slow continuous ultrafiltration (SCUF) and continuous renal replacement therapy (CRRT) - which have to be performed in hospital facilities. Peritoneal ultrafiltration (PUF) can be considered a treatment option in patients with TR-AHDF when, despite the fact that all treatment options have been used, patients meet the following criteria: • stage D decompensated heart failure (ACC/AHA classification); • INTERMACS level 4 decompensated heart failure; • INTERMACS frequent flyer profile; • chronic renal failure (estimated glomerular filtration rate <50 ml/min per 1.73 m2: KDOQI classification stage 3 chronic kidney disease); • no obvious contraindications to peritoneal UF. PUF treatment modes are derived from the treatment regimens proposed by various authors to obtain systemic UF in patients with severe decompensated heart failure, using manual and automated incremental peritoneal dialysis involving various glucose concentrations in addition to the single icodextrin exchange. These guidelines also identify a minimum set of tests and procedures for the follow-up phase, to be supplemented, according to the center's resources and policy, with other tests that

  14. Concentration and separation of biological organisms by ultrafiltration and dielectrophoresis

    DOEpatents

    Simmons, Blake A.; Hill, Vincent R.; Fintschenko, Yolanda; Cummings, Eric B.

    2010-10-12

    Disclosed is a method for monitoring sources of public water supply for a variety of pathogens by using a combination of ultrafiltration techniques together dielectrophoretic separation techniques. Because water-borne pathogens, whether present due to "natural" contamination or intentional introduction, would likely be present in drinking water at low concentrations when samples are collected for monitoring or outbreak investigations, an approach is needed to quickly and efficiently concentrate and separate particles such as viruses, bacteria, and parasites in large volumes of water (e.g., 100 L or more) while simultaneously reducing the sample volume to levels sufficient for detecting low concentrations of microbes (e.g., <10 mL). The technique is also designed to screen the separated microbes based on specific conductivity and size.

  15. Utilizing ultrafiltration to remove alkaline phosphatase from clinical analyzer water.

    PubMed

    Bôle, Julien; Mabic, Stéphane

    2006-01-01

    Alkaline phosphatase (ALP) conjugated to antibodies is often used in enzyme immunoassays (EIAs). These assays are notably sensitive to experimental conditions. A possible source of interference is bacterial ALP, which is released when bacterial contamination occurs in clinical analyzers. Preliminary experiments led to the selection of a detection kit, ALP source, and specific types of tubes for collecting water samples and performing assays. The release of ALP from various strains of bacteria identified in pure water was demonstrated (10-30 x 10(6) cfu/mL released 6-10 microU/microL). It was shown that ultrafiltration is totally efficient in removing ALP from water, while residual ALP activity (2.21 microU/microL after filtration of an ALP solution of 6.22 microU/microL) was observed after filtration using a 0.22-mum filter.

  16. The case for treating refractory congestive heart failure with ultrafiltration.

    PubMed

    Canaud, Bernard; Bowry, Sudhir K; Tetta, Ciro; Gatti, Emanuele

    2014-01-01

    Extracellular fluid retention and congestion is a fundamental manifestation of heart failure (HF) and cardiorenal syndrome (CRS). Patients are normally hospitalized and treated with diuretics, but their outcomes are often poor as severe congestion and diuretics resistance is the primary cause of HF-related hospital admissions and readmissions. Isolated ultrafiltration (UF), which can be considered as a 'mechanical diuretic and natriuretic' tool, offers promise in achieving safe and effective fluid volume removal in HF patients with CRS who are resistant to stepwise guided diuretic therapy. This paper outlines the rationale for machine-driven isolated UF in CRS and the available clinical evidence regarding its use in patients with HF. In addition, this article summarizes some future clinical perspectives for expanding the use of UF therapy in HF patients in order to improve outcomes. PMID:25196568

  17. Peritoneal ultrafiltration in end-stage chronic heart failure

    PubMed Central

    Fröhlich, Hanna; Katus, Hugo A.; Täger, Tobias; Lossnitzer, Nicole; Grossekettler, Leonie; Kihm, Lars; Zeier, Martin; Remppis, Andrew; Frankenstein, Lutz; Schwenger, Vedat

    2015-01-01

    Background Cardiorenal syndrome type 2 (CRS-2) is common in end-stage chronic heart failure (CHF). Peritoneal ultrafiltration (pUF) may entail clinical functional improvement and a reduction in hospitalizations. Methods Thirty-nine consecutive end-stage CHF patients with stable CRS-2 were initiated on ambulatory pUF after interdisciplinary cardiological/nephrological evaluation and prospectively followed for 1 year. All-cause hospitalization was the primary end point. Secondary end points included mortality, treatment alteration and change in weight, NYHA functional class or quality of life (QoL). Outcomes were compared both within the pUF cohort (365 prior to initiation) and with 39 matched CHF patients receiving standard medical treatment. Results Compared with pretreatment, there was a trend to a reduction in 1-year hospitalization days in the pUF group (P = 0.07). One-year mortality was 33% in the pUF group and 23% in the matched control cohort. pUF was stopped in eight patients (18%) due to recurrent peritonitis (n = 3), insufficient ultrafiltration (n = 3) or cardiac recompensation (n = 1). Compared with standard medical treatment, pUF significantly improved volume overload (P < 0.05), NYHA functional class (P < 0.001) and mental health (P < 0.05). Moreover, hospitalization days for all causes as well as cardiovascular hospitalization days were significantly reduced during the interim periods in the pUF group (P < 0.05 and P < 0.001, respectively). Conclusions pUF is effective in improving the clinical condition of end-stage CHF patients suffering from CRS-2. Randomized controlled trials are needed to clarify the effects of pUF on hospitalization and mortality in these patients. PMID:25815181

  18. PORTABLE ULTRAFILTRATION DEVICE FOR CONCENTRATION PATHOGENS FROM LARGE VOUME SAMPLES OF DRINKING WATER

    EPA Science Inventory

    Symposium Paper in proceedings of Water Security Congress, Washington, D.C., 12 Sep 2006 - Development and testing of several potential protocols utilizing ultrafiltration to collect and concentrate microorganisms from large volume water samples.

  19. Class and Home Problems. The Lambert W Function in Ultrafiltration and Diafiltration

    ERIC Educational Resources Information Center

    Foley, Greg

    2016-01-01

    Novel analytical solutions based on the Lambert W function for two problems in ultrafiltration and diafiltration are described. Example problems, suitable for incorporation into an introductory module in unit operations, membrane processing, or numerical methods are provided in each case.

  20. Seawater ultrafiltration: role of particles on organic rejections and permeate fluxes.

    PubMed

    Massé, Anthony; Thi, Hanh Nguyen; Roelens, Guillaume; Legentilhomme, Patrick; Jaouen, Pascal

    2013-01-01

    The role of natural compounds of seawater and added particles on mechanisms of membrane fouling and organic matter rejection has been investigated. Ultrafiltration (100 kDa) has been conducted in both dead-end (out/in) and tangential (in/out) modes on polysulfone hollow fibre membranes. The permeate fluxes are approximately three times higher for tangential ultrafiltration than for dead-end ultrafiltration without differences between settled and non-settled seawaters (NS-SWs) (51-55 L h(-1) m(-2) for tangential and 17-22 L h(-1) m(-2) for dead-end ultrafiltration). Adding bentonite or kieselguhr from 0.13 to 1.13 g L(-1) of suspended solids to NS-SW does not act significantly on permeate fluxes of dead-end contrary to tangential ultrafiltration. For the latter, an addition of particles induces a slight drop of permeate fluxes. Original particles of reconstituted seawater could increase the cake porosity, whereas bentonite and kieselguhr, compounds smaller than original particles, could participate in the formation of a compact cake. The total organic carbon removal was equal to approximately 80% whatever the mode of ultrafiltration may be and the suspended solid concentration ranged from 0.13 to 1.13 g L(-1). Dissolved organic carbon (DOC) and colloidal organic carbon rejection rates were greater for tangential ultrafiltration (37-49%) compared with dead-end ultrafiltration (30-44%) at different concentrations of added particles. Bentonite or kieselguhr addition induced a slight decrease of DOC removal. In the case of particles addition, the worst DOC rejection is found for bentonite.

  1. Ultrafiltration behavior of major ions (Na, Ca, Mg, F, Cl, and SO4) in natural waters.

    PubMed

    Guo, L; Hunt, B J; Santschi, P H

    2001-04-01

    Aquatic colloids, including macromolecules and microparticles, with sizes ranging between 1 nm to 1 micron, play important roles in the mobility and bioavailability of heavy metals and other contaminants in natural waters. Cross-flow ultrafiltration has become one of the most commonly used techniques for isolating aquatic colloids. However, the ultrafiltration behavior of chemical species remains poorly understood. We report here the permeation behavior of major ions (Na, Ca, Mg, F, Cl, and SO4) in natural waters during ultrafiltration using an Amicon 1 kDa ultrafiltration membrane (S10N1). Water samples across a salinity gradient of 0-20@1000 were collected from the Trinity River and Galveston Bay. The permeation behavior of major ions was well predicted by a permeation model, resulting in a constant permeation coefficient for each ion. The value of the model-derived permeation coefficient (Pc) was 0.99 for Na, 0.97 for Cl, and 0.95 for F, respectively, in Trinity River waters. Values of Pc close to 1 indicate that retention of Na, Cl, and F by the 1 kDa membrane during ultrafiltration was indeed minimal (< 1-5%). In contrast, significant (14-36%) retention was observed for SO4, Ca, and Mg in Trinity River waters, with a Pc value of 0.64, 0.82, and 0.86 for SO4, Ca and Mg, respectively. However, these retained major ions can further permeate through the 1 kDa membrane during diafiltration with ultrapure water. The selective retention of major ions during ultrafiltration may have important implications for the measurement of chemical and physical speciation of trace elements when using cross-flow ultrafiltration membranes to separate colloidal species from natural waters. Our results also demonstrate that the percent retention of major ions during ultrafiltration decreases with increasing salinity or ionic strength. This retention is largely attributed to electrostatic repulsion by the negatively charged cartridge membrane.

  2. Ultrafiltration behavior of major ions (Na, Ca, Mg, F, Cl, and SO4) in natural waters.

    PubMed

    Guo, L; Hunt, B J; Santschi, P H

    2001-04-01

    Aquatic colloids, including macromolecules and microparticles, with sizes ranging between 1 nm to 1 micron, play important roles in the mobility and bioavailability of heavy metals and other contaminants in natural waters. Cross-flow ultrafiltration has become one of the most commonly used techniques for isolating aquatic colloids. However, the ultrafiltration behavior of chemical species remains poorly understood. We report here the permeation behavior of major ions (Na, Ca, Mg, F, Cl, and SO4) in natural waters during ultrafiltration using an Amicon 1 kDa ultrafiltration membrane (S10N1). Water samples across a salinity gradient of 0-20@1000 were collected from the Trinity River and Galveston Bay. The permeation behavior of major ions was well predicted by a permeation model, resulting in a constant permeation coefficient for each ion. The value of the model-derived permeation coefficient (Pc) was 0.99 for Na, 0.97 for Cl, and 0.95 for F, respectively, in Trinity River waters. Values of Pc close to 1 indicate that retention of Na, Cl, and F by the 1 kDa membrane during ultrafiltration was indeed minimal (< 1-5%). In contrast, significant (14-36%) retention was observed for SO4, Ca, and Mg in Trinity River waters, with a Pc value of 0.64, 0.82, and 0.86 for SO4, Ca and Mg, respectively. However, these retained major ions can further permeate through the 1 kDa membrane during diafiltration with ultrapure water. The selective retention of major ions during ultrafiltration may have important implications for the measurement of chemical and physical speciation of trace elements when using cross-flow ultrafiltration membranes to separate colloidal species from natural waters. Our results also demonstrate that the percent retention of major ions during ultrafiltration decreases with increasing salinity or ionic strength. This retention is largely attributed to electrostatic repulsion by the negatively charged cartridge membrane. PMID:11317897

  3. Ultrafiltration – an alternative method to polyethylene glycol precipitation for macroprolactin detection

    PubMed Central

    Beda-Maluga, Karolina; Pisarek, Hanna; Romanowska, Irena; Komorowski, Jan; Świętosławski, Jacek

    2015-01-01

    Introduction The aim of the study was to evaluate two methods of macroprolactin (MaPRL) detection – precipitation with polyethylene glycol (PEG) and ultrafiltration and to compare these techniques with “gold standard” – gel filtration chromatography (GFC). Material and methods The study was conducted on 245 patients – 45 with organic and 200 with functional hyperprolactinaemia. In all the subjects MaPRL was detected by precipitation with PEG and ultrafiltration. Additionally, gel filtration chromatography was performed in some of the serum samples. Results Macroprolactinaemia was detected in 27 patients – 8 with prolactinoma and 19 with functional hyperprolactinaemia. Assessing positive and negative results for MaPRL, we observed high diagnostic agreement (95.9%) and positive correlation (r = 0.506, p < 0.001) between the methods. The results of precipitation and ultrafiltration positive for MaPRL were concordant in 63%. The dominance of MaPRL detected with precipitation and/or ultrafiltration was confirmed by GFC in 76% of cases (all patients with functional hyperprolactinaemia). Among 6 examined patients with prolactinoma, GFC showed four false-positive results – 1 case of precipitation and 3 cases of ultrafiltration. Conclusions Efficacy of MaPRL detection with precipitation and ultrafiltration is comparable especially in cases of functional hyperprolactinaemia. In patients with prolactinoma, precipitation seems to be a more efficient separation method. PMID:26528343

  4. Noncasein nitrogen analysis of ultrafiltration and microfiltration retentate.

    PubMed

    Zhang, H; Metzger, L E

    2011-04-01

    Previous research has suggested that the standard noncasein nitrogen (NCN) measurement method for milk overestimates the NCN content of microfiltration (MF) retentate. The objective of this study was to develop a modified method to more accurately measure the NCN content of ultrafiltration and MF retentate products. The standard method is based on precipitation of casein micelles at their isoelectric point (4.6) with acetic acid. In the standard method, a 10-mL milk sample and 75 mL of 38°C water are placed in a 100-mL volumetric flask. One milliliter of 10% acetic acid solution is added and the flask is incubated at 38°C for 10 min. Subsequently, 1 mL of 1N sodium acetate solution is added and mixed. After cooling the contents to 20°C, the flask is made up to 100mL with water, mixed, and then filtered (Whatman No. 1 filter paper). The N content of the filtrate is then determined by Kjeldahl analysis and referred to as NCN. A method was developed that used a 50-mL centrifugal tube instead of a volumetric flask. This modification facilitated measurement of the pH after addition of acetic acid. Subsequently, the sample was centrifuged (800×g at 25°C) for 10 min to facilitate filtration with a smaller pore size filter paper (Whatman no. 6). In this study, we evaluated the effect of pH after addition of 1% acetic acid and pH of the final filtrate on NCN analysis. Four pH levels after acetic acid addition (4.0, 4.2, 4.4, and 4.6) and 2 pH levels after sodium acetate addition (4.6 and 4.8) were evaluated. As the pH after acetic acid addition was increased from 4.0 to 4.6, the NCN content significantly decreased. Sodium dodecyl sulfate PAGE results also indicated that the casein fractions present in the filtrate were significantly decreased when the pH was increased from 4.0 to 4.6. The NCN content slightly decreased but the difference was not significant when the final pH of the filtrate was increased from 4.6 to 4.8. Subsequently, the NCN contents of several

  5. Adsorption combined with ultrafiltration to remove organic matter from seawater.

    PubMed

    Tansakul, Chatkaew; Laborie, Stéphanie; Cabassud, Corinne

    2011-12-01

    Organic fouling and biofouling are the major severe types of fouling of reverse osmosis (RO) membranes in seawater (SW) desalination. Low pressure membrane filtration such as ultrafiltration (UF) has been developed as a pre-treatment before reverse osmosis. However, UF alone may not be an effective enough pre-treatment because of the existence of low-molecular weight dissolved organic matter in seawater. Therefore, the objective of the present work is to study a hybrid process, powdered activated carbon (PAC) adsorption/UF, with real seawater and to evaluate its performance in terms of organic matter removal and membrane fouling. The effect of different PAC types and concentrations is evaluated. Stream-activated wood-based PAC addition increased marine organic matter removal by up to 70% in some conditions. Moreover, coupling PAC adsorption with UF decreased UF membrane fouling and the fouling occurring during short-term UF was totally reversible. It can be concluded that the hybrid PAC adsorption/UF process performed in crossflow filtration mode is a relevant pre-treatment process before RO desalination, allowing organic matter removal of 75% and showing no flux decline for short-term experiments. PMID:21996607

  6. Biodegradation of Microcystins during Gravity-Driven Membrane (GDM) Ultrafiltration

    PubMed Central

    Kohler, Esther; Villiger, Jörg; Posch, Thomas; Derlon, Nicolas; Shabarova, Tanja; Morgenroth, Eberhard; Pernthaler, Jakob; Blom, Judith F.

    2014-01-01

    Gravity-driven membrane (GDM) ultrafiltration systems require little maintenance: they operate without electricity at ultra-low pressure in dead-end mode and without control of the biofilm formation. These systems are already in use for water purification in some regions of the world where adequate treatment and distribution of drinking water is not readily available. However, many water bodies worldwide exhibit harmful blooms of cyanobacteria that severely lower the water quality due to the production of toxic microcystins (MCs). We studied the performance of a GDM system during an artificial Microcystis aeruginosa bloom in lake water and its simulated collapse (i.e., the massive release of microcystins) over a period of 21 days. Presence of live or destroyed cyanobacterial cells in the feed water decreased the permeate flux in the Microcystis treatments considerably. At the same time, the microbial biofilms on the filter membranes could successfully reduce the amount of microcystins in the filtrate below the critical threshold concentration of 1 µg L−1 MC for human consumption in three out of four replicates after 15 days. We found pronounced differences in the composition of bacterial communities of the biofilms on the filter membranes. Bacterial genera that could be related to microcystin degradation substantially enriched in the biofilms amended with microcystin-containing cyanobacteria. In addition to bacteria previously characterized as microcystin degraders, members of other bacterial clades potentially involved in MC degradation could be identified. PMID:25369266

  7. Ultrafiltration of charge-stabilized dispersions at low salinity.

    PubMed

    Roa, Rafael; Menne, Daniel; Riest, Jonas; Buzatu, Pompilia; Zholkovskiy, Emiliy K; Dhont, Jan K G; Wessling, Matthias; Nägele, Gerhard

    2016-05-18

    We present a comprehensive study of cross-flow ultrafiltration (UF) of charge-stabilized suspensions, under low-salinity conditions of electrostatically strongly repelling colloidal particles. The axially varying permeate flux, near-membrane concentration-polarization (CP) layer and osmotic pressure profiles are calculated using a macroscopic diffusion-advection boundary layer method, and are compared with filtration experiments on aqueous suspensions of charge-stabilized silica particles. The theoretical description based on the one-component macroion fluid model (OCM) accounts for the strong influence of surface-released counterions on the renormalized colloid charge and suspension osmotic compressibility, and for the influence of the colloidal hydrodynamic interactions and electric double layer repulsion on the concentration-dependent suspension viscosity η, and collective diffusion coefficient Dc. A strong electro-hydrodynamic enhancement of Dc and η, and likewise of the osmotic pressure, is predicted theoretically, as compared with their values for a hard-sphere suspension. We also point to the failure of generalized Stokes-Einstein relations describing reciprocal relations between Dc and η. According to our filtration model, Dc is of dominant influence, giving rise to an only weakly developed CP layer having practically no effect on the permeate flux. This prediction is quantitatively confirmed by our UF measurements of the permeate flux using an aqueous suspension of charged silica spheres as the feed system. The experimentally detected fouling for the largest considered transmembrane pressure values is shown not to be due to filter cake formation by crystallization or vitrification.

  8. Separation of proteases from yellowfin tuna spleen by ultrafiltration.

    PubMed

    Li, Zhenyu; Youravong, Wirote; H-Kittikun, Aran

    2006-12-01

    Separation of protease, trypsin and chymotrypsin from yellowfin tuna spleen extract by ultrafiltration (UF) using regenerated cellulose membranes with molecular weight cut off (MWCO) 30 and 100 kDa was studied. The 100 kDa membrane had a higher transmission of enzymes than that of the 30 kDa membrane. The enzyme transmission varied from 0.01 to 0.18 and from 0.6 to 0.8 for the 30 kDa membrane and 100 kDa membrane, respectively. The protein transmission was about 0.8 for both membranes. Increasing cross-flow rate and transmembrane pressure (TMP) increased permeate flux. The limiting fluxes at cross-flow rate 120, 240 and 360 L/h for the 30 kDa membrane were 17.3, 43.9 and 54.7 L/m2h, respectively and the limiting fluxes at the same flow rate for 100 kDa membrane were 34.1, 51.1 and 68.4 L/m2h, respectively. The separation of these proteases was achieved using the 30 kDa membrane. The purities of proteases were increased more than ten times at TMP 1.5 bar and cross-flow rate 360 L/h by diafiltration using 30 kDa membrane. PMID:16314093

  9. Effect of ozone on biopolymers in biofiltration and ultrafiltration processes.

    PubMed

    Siembida-Lösch, Barbara; Anderson, William B; Wang, Yulang Michael; Bonsteel, Jane; Huck, Peter M

    2015-03-01

    The focus of this full-scale study was to determine the effect of ozone on biopolymer concentrations in biofiltration and ultrafiltration (UF) processes treating surface water from Lake Ontario. Ozonation was out of service for maintenance for 9 months, hence, it was possible to investigate ozone's action on biologically active carbon contactors (BACCs) and UF, in terms of biopolymer removal. Given the importance of biopolymers for fouling, this fraction was quantified using a chromatographic technique. Ozone pre-treatment was observed to positively impact the active biomass in biofilters. However, since an increase of the active biomass did not result in higher biopolymer removal, active biomass concentration cannot be a surrogate for biofiltration performance. It was evident that increasing empty bed contact time (EBCT) from 4 to 19 min only had a positive effect on biopolymer removal through BACCs when ozone was out of service. However, as a mass balance experiment showed, ozone-free operation resulted in higher deposition of biopolymers on a UF membrane and slight deterioration in its performance. PMID:25540836

  10. Investigation of membrane fouling in ultrafiltration using model organic compounds.

    PubMed

    Kweon, J H; Lawler, D F

    2005-01-01

    Natural organic matter (NOM) is known to be the worst foulant in the membrane processes, but the complexities of NOM make it difficult to determine its effects on membrane fouling. Therefore, simple organic compounds (surrogates for NOM) were used in this research to investigate the fouling mechanisms in ultrafiltration. Previous research on NOM components in membrane processes indicated that polysaccharides formed an important part of the fouling cake. Three polysaccharides (dextran, alginic acid, and polygalacturonic acid) and a smaller carbohydrate (tannic acid) were evaluated for their removal in softening (the treatment process in the City of Austin). Two polysaccharides (dextran and alginic acid) were selected and further investigated for their effects on membrane fouling. The two raw organic waters (4 mg/L C) showed quite different patterns of flux decline indicating different fouling mechanisms. Softening pretreatment was effective to reduce flux decline of both waters. The SEM images of the fouled membrane clearly showed the shapes of deposited foulants. The high resolution results of the XPS spectra showed substantially different spectra of carbon, C(1s), in the membrane fouled by two raw organic waters. The XPS was beneficial in determining the relative composition of each fouling material on the membrane surface.

  11. Summary of the ultrafiltration, reverse osmosis, and adsorbents project

    NASA Astrophysics Data System (ADS)

    Colvin, C. M.; Roberts, R. C.; Williams, M. K.

    1983-01-01

    The design for a medium size (40 gal/min) ultrafiltration (UF) membrane unit includes a schematic diagram, capital and operating costs, a list and discussion of the radioisotopes tested and the results achieved, operating parameters, and characteristics of the available membrane configurations. The plant design for a reverse osmosis (RO) membrane unit includes a conceptual diagram, specifications for a RO unit producing 40 gal/min of permeated product, a list of radioisotopes tested on RO units and the rejections achieved, a discussion of the principal of RO, a discussion of the upper limits of cation and anion concentrations (there are no lower limits), a discussion of membrane configurations and porosities, a discussion of factors affecting membranes, a section on calculating the membrane area needed for a particular application, and capital and operating cost calculations. The design for an ion exchange pilot plant includes a schematic diagram; flow, resin, and column specifications; impurity limits; and operating and capital costs. A short theoretical discussion and process description are also included. The design retains flexibility so that application to a specific stream can be determined.

  12. Calcium release from milk concentrated by ultrafiltration and diafiltration.

    PubMed

    Li, Y; Corredig, M

    2014-09-01

    The present work studied the solubilization of Ca during acidification in milk concentrated by ultrafiltration (UF) and diafiltration (DF). The effect of heating milk at 80°C for 15min was also evaluated. In addition to measuring buffering capacity, the amount of Ca released as a function of pH was determined. The area of the maximum peak in buffering capacity observed at pH ~5.1, related to the presence of colloidal Ca phosphate, was significantly affected by casein volume fraction but did not increase proportionally with casein concentration. In addition, a lower buffering capacity and less solubilized Ca were measured in 2× DF milk compared with 2× UF milk. Heat treatment did not change the buffering capacity or Ca release in 1× and 2× concentrated milk. On the other hand, at a higher volume fraction (4×), more Ca was present in the soluble phase in heated 4× UF and DF milk compared with unheated milk. This is the first comprehensive study on the effect of concentration, distinguishing the effect of UF from that of DF, before and after heating, on Ca solubilization. PMID:25022683

  13. Reduced fouling of ultrafiltration membranes via surface fluorination

    SciTech Connect

    Sedath, R.H.; Yates, S.F.; Li, N.N.

    1993-03-01

    Surface fluorination can affect significantly the performance of an ultrafiltration membrane used to concentrate a food-related stream. Membranes fluorinated and tested as flat sheets exhibit higher initial fluxes, and do not foul as rapidly as untreated membranes. This improvement is linked to increased surface hydrophilicity, as shown in decreased contact angle with water. This increased hydrophilicity, in turn, is linked to the addition of fluorine and oxygen to the surface. The pilot plant study did-not show the difference in membrane flux and fouling observed in the flat sheet study. Instead, fluorinated and unfluorinated modules behaved similarly. Fouling by potato waste feed was severe and resulted in formation of an extensive gel layer within the module on the membrane surface. XPS, SEM and FTIR indicate that buildup of organic material occurred on both fluorinated and unfluorinated membranes, but SEM indicates that a fibrous mat of material was observed only on the nonfluorinated membrane. We conclude that in the pilot study, membrane fouling and gel formation were so extensive that the surface interaction effect was overwhelmed.

  14. Removal of phenolic compounds in water by ultrafiltration membrane treatments.

    PubMed

    Acero, Juan L; Benítez, F Javier; Leal, Ana I; Real, Francisco J

    2005-01-01

    The ultrafiltration (UF) of aqueous solutions containing mixtures of three phenolic compounds (gallic acid, acetovanillone, and esculetin) was studied in a tangential UF laboratory system. These substances were selected as model pollutants present in the tannic fraction of the cork processing wastewaters. The two membranes used were a polyethersulfone membrane (Biomax5K) and a regenerated cellulose membrane (Ultracel5K), both with a molecular weight cut-off (MWCO) of 5000 Da. Previous experiments for the characterization of the membranes led to values for the water hydraulic permeability of 70.3 and 18.1 L/h x m2 x bar for the Biomax5K and Ultracel5K membranes, respectively. During the UF experiments, the permeate flow rate remained almost constant with processing time and the evolution of the pollutants concentrations varied depending on the nature of the membranes and the substances. The influence of the main operating variables (tansmembrane pressure and feed flow rate) on the permeate flux was established, and values for the apparent and intrinsic rejection coefficients were evaluated. Cork processing wastewater UF experiments were also conducted under similar operating conditions to those applied to the ultrapure water solutions. Removals of chemical oxygen demand, aromatic and tannic contents, and color were determined in these experiments, and the elimination of the three model compounds in the wastewater was also followed, with the evaluation of their apparent rejection coefficients.

  15. Direct ultrafiltration performance and membrane integrity monitoring by microbiological analysis.

    PubMed

    Ferrer, O; Casas, S; Galvañ, C; Lucena, F; Bosch, A; Galofré, B; Mesa, J; Jofre, J; Bernat, X

    2015-10-15

    The feasibility of substituting a conventional pre-treatment, consisting of dioxi-chlorination, coagulation/flocculation, settling and sand filtration, of a drinking water treatment plant (DWTP) by direct ultrafiltration (UF) has been assessed from a microbiological standpoint. Bacterial indicators, viral indicators and human viruses have been monitored in raw river, ultrafiltered and conventionally pre-treated water samples during two years. Direct UF has proven to remove bacterial indicators quite efficiently and to a greater extent than the conventional process does. Nevertheless, the removal of small viruses such as some small bacteriophages and human viruses (e.g. enteroviruses and noroviruses) is lower than the current conventional pre-treatment. Membrane integrity has been assessed during two years by means of tailored tests based on bacteriophages with different properties (MS-2, GA and PDR-1) and bacterial spores (Bacillus spores). Membrane integrity has not been compromised despite the challenging conditions faced by directly treating raw river water. Bacteriophage PDR-1 appears as a suitable microbe to test membrane integrity, as its size is slightly larger than the considered membrane pore size. However, its implementation at full scale plant is still challenging due to difficulties in obtaining enough phages for its seeding.

  16. Adsorption combined with ultrafiltration to remove organic matter from seawater.

    PubMed

    Tansakul, Chatkaew; Laborie, Stéphanie; Cabassud, Corinne

    2011-12-01

    Organic fouling and biofouling are the major severe types of fouling of reverse osmosis (RO) membranes in seawater (SW) desalination. Low pressure membrane filtration such as ultrafiltration (UF) has been developed as a pre-treatment before reverse osmosis. However, UF alone may not be an effective enough pre-treatment because of the existence of low-molecular weight dissolved organic matter in seawater. Therefore, the objective of the present work is to study a hybrid process, powdered activated carbon (PAC) adsorption/UF, with real seawater and to evaluate its performance in terms of organic matter removal and membrane fouling. The effect of different PAC types and concentrations is evaluated. Stream-activated wood-based PAC addition increased marine organic matter removal by up to 70% in some conditions. Moreover, coupling PAC adsorption with UF decreased UF membrane fouling and the fouling occurring during short-term UF was totally reversible. It can be concluded that the hybrid PAC adsorption/UF process performed in crossflow filtration mode is a relevant pre-treatment process before RO desalination, allowing organic matter removal of 75% and showing no flux decline for short-term experiments.

  17. Effect of ozone on biopolymers in biofiltration and ultrafiltration processes.

    PubMed

    Siembida-Lösch, Barbara; Anderson, William B; Wang, Yulang Michael; Bonsteel, Jane; Huck, Peter M

    2015-03-01

    The focus of this full-scale study was to determine the effect of ozone on biopolymer concentrations in biofiltration and ultrafiltration (UF) processes treating surface water from Lake Ontario. Ozonation was out of service for maintenance for 9 months, hence, it was possible to investigate ozone's action on biologically active carbon contactors (BACCs) and UF, in terms of biopolymer removal. Given the importance of biopolymers for fouling, this fraction was quantified using a chromatographic technique. Ozone pre-treatment was observed to positively impact the active biomass in biofilters. However, since an increase of the active biomass did not result in higher biopolymer removal, active biomass concentration cannot be a surrogate for biofiltration performance. It was evident that increasing empty bed contact time (EBCT) from 4 to 19 min only had a positive effect on biopolymer removal through BACCs when ozone was out of service. However, as a mass balance experiment showed, ozone-free operation resulted in higher deposition of biopolymers on a UF membrane and slight deterioration in its performance.

  18. Investigation of membrane fouling in ultrafiltration using model organic compounds.

    PubMed

    Kweon, J H; Lawler, D F

    2005-01-01

    Natural organic matter (NOM) is known to be the worst foulant in the membrane processes, but the complexities of NOM make it difficult to determine its effects on membrane fouling. Therefore, simple organic compounds (surrogates for NOM) were used in this research to investigate the fouling mechanisms in ultrafiltration. Previous research on NOM components in membrane processes indicated that polysaccharides formed an important part of the fouling cake. Three polysaccharides (dextran, alginic acid, and polygalacturonic acid) and a smaller carbohydrate (tannic acid) were evaluated for their removal in softening (the treatment process in the City of Austin). Two polysaccharides (dextran and alginic acid) were selected and further investigated for their effects on membrane fouling. The two raw organic waters (4 mg/L C) showed quite different patterns of flux decline indicating different fouling mechanisms. Softening pretreatment was effective to reduce flux decline of both waters. The SEM images of the fouled membrane clearly showed the shapes of deposited foulants. The high resolution results of the XPS spectra showed substantially different spectra of carbon, C(1s), in the membrane fouled by two raw organic waters. The XPS was beneficial in determining the relative composition of each fouling material on the membrane surface. PMID:16003967

  19. Dynamics and rheology of fouling cakes formed during ultrafiltration

    SciTech Connect

    Datta, S.; Gaddis, J.L.

    1997-01-01

    The solute cake which forms on a membrane surface during ultrafiltration processes is well known for its fouling characteristics. The dynamics and rheology of the cake are investigated and observed under the action of cross-flow shear. Experiments with slurries having 300 nm diameter particles of titanium dioxide indicate average volume concentrations of 0.56 or 0.57 and show that this cake indeed {open_quote}flows{close_quote} with a creeping velocity under applied shear. The cake thickness reaches a steady state when the solute advection towards the membrane balances the solute mass carried away at the trailing edge by the creeping cake. The viscosity-shear rate dependence of this layer is determined experimentally and the {open_quote}creeping velocity{close_quote} of the cake is calculated assuming the transverse drag force is determined from the Kozeny-Carman equation. Upon instantaneous compression the cake compresses while maintaining its mass distribution. The change in cake resistance allows interpretation of the pressure modified concentration. The volume concentration, determined from the mathematical modeling, is shown to lie between 0.54 to 0.65. Observations show that the top few layers of this cake move freely with the shearing flow due to the lifting action of normal stresses in the cake under external shear. Volume concentrations up to 0.65 are indicated from the analysis.

  20. Screening for inhibitors of dihydrofolate reductase using pulsed ultrafiltration mass spectrometry.

    PubMed

    Nikolic, D; van Breemen, R B

    1998-04-01

    A method of screening combinatorial libraries for inhibitors of eukaryotic dihydrofolate reductase has been developed using pulsed ultra-filtration electrospray mass spectrometry, which is a continuous-flow affinity separation system for extracting and identifying high affinity ligands in combinatorial libraries. In this application, pulsed ultrafiltration conditions were optimized for the isolation and identification of inhibitors of dihydrofolate reductase from a 22 compound library containing six known inhibitors of the enzyme including trimethoprim, aminopterin, methotrexate, pyrimethamine, folic acid, and folinic acid, and 16 compounds without known affinity. In order to optimize the screening method, sources of non-specific binding were identified and minimized. A significant source of non-specific binding for this set of library compounds was hydrophobic interaction with the surfaces of the ultrafiltration chamber. After affinity separation of bound (high affinity) versus free (low affinity) library compounds during pulsed ultrafiltration, receptor-bound ligands were released and eluted using either organic solvent or acidified mobile phase. Although 80% methanol easily disrupted the receptor-ligand complexes, organic solvent had the undesirable effect of releasing non-specifically bound compounds from the chamber and thereby increasing the background noise. Interference from non-specific binding was minimized by releasing bound ligands using a low pH mobile phase eluent instead of organic solvent. Under the conditions used, pulsed ultrafiltration mass spectrometry selectively identified the two library compounds with the highest affinity for dihydrofolate reductase, methotrexate and aminopterin.

  1. Identification of the Allergenic Ingredients in Reduning Injection by Ultrafiltration and High-Performance Liquid Chromatography

    PubMed Central

    Wang, Fang; Li, Cun-yu; Zheng, Yun-feng; Li, Hong-yang; Xiao, Wei; Peng, Guo-ping

    2016-01-01

    Reduning injection is a traditional Chinese medicine injection which has multiple functions such as clearing heat, dispelling wind, and detoxification. Although Reduning injection was widely utilized, reports of its allergenicity emerged one after another. However, there is little research on its allergenic substances. The aim of this study is to evaluate the sensitization of Reduning injection and explore the underlying cause of the anaphylactic reaction. The main ingredients in Reduning injection were analyzed before and after ultrafiltration. Ultrafiltrate Reduning injection, unfiltered Reduning injection, egg albumin, Tween-80, and nine effective components in Reduning injection were utilized to sensitize guinea pigs. The serum 5-hydroxytryptamine level was used to assess the sensitization effect of Reduning injection. We found a significant decrease in Tween-80 content comparing to other components in the injection after ultrafiltration. Unfiltered Reduning injection, Tween-80, chlorogenic acid, and cryptochlorogenin acid caused remarkable anaphylactoid reaction on guinea pigs while ultrafiltration Reduning resulted in a significantly lower degree of sensitization. Our results suggest that ultrafiltration could significantly reduce the sensitization of Reduning injection, which is likely due to the decrease of Tween-80. We also conjectured that the form of chlorogenic acid and cryptochlorogenin acid within the complex solution mixture may also affect the sensitizing effect. PMID:27144180

  2. Cardiorenal Syndrome: Ultrafiltration Therapy for Heart Failure—Trials and Tribulations

    PubMed Central

    2013-01-01

    Summary Heart failure remains the leading cause of hospitalization in older patients and is considered a growing public health problem with a significant financial burden on the health care system. The suboptimal efficacy and safety profile of diuretic-based therapeutic regimens coupled with unsatisfactory results of the studies on novel pharmacologic agents have positioned ultrafiltration on the forefront as an appealing therapeutic option for patients with acute decompensated heart failure (ADHF). In recent years, substantial interest in the use of ultrafiltration has been generated due to the advent of dedicated portable devices and promising results of trials focusing both on mechanistic and clinical aspects of this therapeutic modality. This article briefly reviews the proposed benefits of ultrafiltration therapy in the setting of ADHF and summarizes the major findings of the currently available studies in this field. The results of more recent trials on cardiorenal syndrome that present a counterpoint to previous observations and highlight certain limitations of ultrafiltration therapy are then discussed, followed by identification of major challenges and unanswered questions that could potentially hinder its more widespread use. Future studies are warranted to shed light on less well characterized aspects of ultrafiltration therapy and to further define its role in ADHF and cardiorenal syndrome. PMID:23723339

  3. Cross-flow ultrafiltration of micellar surfactant solutions

    SciTech Connect

    Markels, J.H.; Lynn, S.; Radke, C.J.

    1995-09-01

    A steady-state fouling-resistance and osmotic-pressure model is used to predict flux in the laminar, cross-flow ultrafiltration of micellar cetyl (=hexadecyl)pyridinium chloride (CPC) solutions at 0.01-M NaCl background electrolyte. The model assumes a constant overall hydraulic resistance including the effect of surfactant fouling and native membrane resistance. Measurements of osmotic pressures of CPC solutions at 0.01-M NaCl as a function of surfactant concentration describe the effect of concentration polarization on permeate flux. Two types of asymmetric polyethersulfone membranes are used: 5,000 molecular weight cutoff (MWCO) membranes that allow partial monomer permeation, but quantitatively reject all micelles; 50,000 MWCO membranes that allow some micelle permeation. For the former, the intrinsic rejection coefficient for monomer, measured separately, is sufficient to describe surfactant rejection, without adjustable parameters. Predictions of the volumetric flux of the permeate, including the value of the limiting flux, agree well with the experimental results over the entire range of pressure drop, axial velocity, and bulk surfactant concentration. For the 50,000 MWCO membranes the data are described using a best-fit value of the overall surfactant rejection coefficient. For the first time, unusual behavior is observed experimentally in which the flux levels off with increasing pressure drop across the membrane, only to increase sharply again at higher applied pressure drop. Both effects are in accord with the proposed model. No gel layer need be postulated to explain the flux behavior of either membrane type.

  4. Application of ultrafiltration technique for the quality improvement of dahi.

    PubMed

    Meena, P K; Gupta, V K; Meena, G S; Raju, P N; Parmar, P T

    2015-12-01

    Ultrafiltered milk (UF1 and UF2), ultrafiltrate retentate added milk (UF3 and UF4) and SMP added milk (UF0) were used for dahi preparation in the present study. Treatments were evaluated for rheological, textural and sensorial characteristics. Significant increase (p < 0.01) in values of firmness, stickiness, work of shear, work of adhesion and sensory scores, but significant decrease (p < 0.01) in whey syneresis values were observed with treatments UF1, UF2, UF3 and UF4 as compared to UF0. Principal component analysis (PCA) revealed that first four principal components (PC) explained 87.39 % relationship between samples and attributes. PC1 accounted for 48.34 % of data variance was characterized by protein content, firmness, work of shear, body & texture and opposed by total carbohydrates, stickiness, syneresis and work of adhesion. Total carbohydrates content (r = -0.982, P < 0.01), whey syneresis (r = -0.783, P < 0.01), stickiness (r = -0.729, P < 0.01) and work of adhesion (r = -0.684, P < 0.01) are negatively while body and texture (r = +0.600, P < 0.01), firmness (r = +0.574, P < 0.05) and work of shear (r = +0.538, P < 0.05) of dahi are highly positively correlated with protein content.

  5. Ultrafiltration of charge-stabilized dispersions at low salinity.

    PubMed

    Roa, Rafael; Menne, Daniel; Riest, Jonas; Buzatu, Pompilia; Zholkovskiy, Emiliy K; Dhont, Jan K G; Wessling, Matthias; Nägele, Gerhard

    2016-05-18

    We present a comprehensive study of cross-flow ultrafiltration (UF) of charge-stabilized suspensions, under low-salinity conditions of electrostatically strongly repelling colloidal particles. The axially varying permeate flux, near-membrane concentration-polarization (CP) layer and osmotic pressure profiles are calculated using a macroscopic diffusion-advection boundary layer method, and are compared with filtration experiments on aqueous suspensions of charge-stabilized silica particles. The theoretical description based on the one-component macroion fluid model (OCM) accounts for the strong influence of surface-released counterions on the renormalized colloid charge and suspension osmotic compressibility, and for the influence of the colloidal hydrodynamic interactions and electric double layer repulsion on the concentration-dependent suspension viscosity η, and collective diffusion coefficient Dc. A strong electro-hydrodynamic enhancement of Dc and η, and likewise of the osmotic pressure, is predicted theoretically, as compared with their values for a hard-sphere suspension. We also point to the failure of generalized Stokes-Einstein relations describing reciprocal relations between Dc and η. According to our filtration model, Dc is of dominant influence, giving rise to an only weakly developed CP layer having practically no effect on the permeate flux. This prediction is quantitatively confirmed by our UF measurements of the permeate flux using an aqueous suspension of charged silica spheres as the feed system. The experimentally detected fouling for the largest considered transmembrane pressure values is shown not to be due to filter cake formation by crystallization or vitrification. PMID:27113088

  6. Enhanced starch hydrolysis using α-amylase immobilized on cellulose ultrafiltration affinity membrane.

    PubMed

    Konovalova, Viktoriia; Guzikevich, Kateryna; Burban, Anatoliy; Kujawski, Wojciech; Jarzynka, Karolina; Kujawa, Joanna

    2016-11-01

    In order to prepare ultrafiltration membranes possessing biocatalytic properties, α-amylase has been immobilized on cellulose membranes. Enzyme immobilization was based on a covalent bonding between chitosan and a surface of cellulose membrane, followed by an attachment of Cibacron Blue F3G-A dye as affinity ligand. Various factors affecting the immobilization process, such as enzyme concentration, pH of modifying solution, zeta-potential of membrane surface, and stability of immobilized enzyme were studied. The applicability of immobilized α-amylase has been investigated in ultrafiltration processes. The immobilization of α-amylase on membrane surface allows to increase the value of mass transfer coefficient and to decrease the concentration polarization effect during ultrafiltration of starch solutions. The enzyme layer on the membrane surface prevents a rapid increase of starch concentration due to the amylase hydrolysis of starch in the boundary layer. The presented affinity immobilization technique allows also for the regeneration of membranes from inactivated enzyme.

  7. Efficient and predictable recovery of viruses from water by small scale ultrafiltration systems.

    PubMed

    Winona, L J; Ommani, A W; Olszewski, J; Nuzzo, J B; Oshima, K H

    2001-11-01

    Current methods to concentrate viruses from large volumes of water are prone to inconsistent results and are costly and complex procedurally. Ultrafiltration can utilize size exclusion rather than adsorption and (or) elution to concentrate viruses and, therefore, may offer greater flexibility in developing methods that can provide more consistent recoveries among different viruses and widely varying water conditions. Two small scale ultrafiltration systems (hollow fiber and tangential flow) were tested with a virus suspended in 2 L of reagent grade, tap, ground, or surface water. Three model viruses were used (bacteriophages PP7 and T1 and poliovirus) to compare and characterize the recovery of viruses with the two ultrafiltration systems. Pretreatment of the ultrafilters with blocking agents and the use of elution agents can serve to prevent viral adsorption to the filter surface or to elute bound virus and keep viral agents suspended in the retentate. The use of a blocking and elution step concentrated viruses (>60% recovery) from widely varying water qualities, including surface water, such that a single method can be used to efficiently concentrate viruses from all of the water types tested. Both ultrafiltration systems appear to be able to efficiently recover viruses; however, the hollow fiber systems provided slightly better results in the 2-L volumes tested.

  8. Ultrafiltrate and microdialysis DL probe in vitro recoveries: electrolytes and metabolites

    NASA Technical Reports Server (NTRS)

    Janle, E. M.; Cregor, M.

    1996-01-01

    UF ultrafiltration and DL microdialysis probes are well-suited for sampling interstitial concentrations of ions and metabolites in peripheral tissue. The first step in utilization of membrane sampling techniques is to determine the recovery characteristics of the probes in vitro.

  9. Solution of Algebraic Equations in the Analysis, Design, and Optimization of Continuous Ultrafiltration

    ERIC Educational Resources Information Center

    Foley, Greg

    2011-01-01

    Continuous feed and bleed ultrafiltration, modeled with the gel polarization model for the limiting flux, is shown to provide a rich source of non-linear algebraic equations that can be readily solved using numerical and graphical techniques familiar to undergraduate students. We present a variety of numerical problems in the design, analysis, and…

  10. Improved solubility and emulsification of wet-milled corn germ protein recovered by ultrafiltration-diafiltration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated ultrafiltration-diafiltration (UFDF) as a means to improve the extractability of wet-milled corn germ protein and determined its effects on the functional properties of the recovered protein product. Wet germ (WG) and finished germ (FG) proteins (Pr) were extracted by using 0.1M...

  11. Ultrafiltration by a compacted clay membrane-II. Sodium ion exclusion at various ionic strengths

    USGS Publications Warehouse

    Hanshaw, B.B.; Coplen, T.B.

    1973-01-01

    Several recent laboratory studies and field investigations have indicated that shales and compacted clay minerals behave as semipermeable membranes. One of the properties of semipermeable membranes is to retard or prevent the passage of charged ionic species through the membrane pores while allowing relatively free movement of uncharged species. This phenomenon is termed salt filtering, reverse osmosis, or ultrafiltration. This paper shows how one can proceed from the ion exchange capacity of clay minerals and, by means of Donnan membrane equilibrium concept and the Teorell-Meyer-Siever theory, develop a theory to explain why and to what extent ultrafiltration occurs when solutions of known concentration are forced to flow through a clay membrane. Reasonable agreement between theory and laboratory results were found. The concentration of the ultrafiltrate was always greater than predicted because of uncertainty in values of some parameters in the equations. Ultrafiltration phenomena may be responsible for the formation of some subsurface brines and mineral deposits. The effect should also be taken into consideration in any proposal for subsurface waste emplacement in an environment containing large quantities of clay minerals. ?? 1973.

  12. Nutrient Recovery from the Dry Grind Process Using Sequential Micro and Ultrafiltration of Thin Stillage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effectiveness of microfiltration (MF) and ultrafiltration (UF) for nutrient recovery from a thin stillage stream was determined. When a stainless steel MF membrane (0.1 um pore size) was used, the content of solids increased from 7.0% to 22.8% with a mean permeate flux rate of 45 L/m**2/h (LMH)...

  13. Effects of electric fields on the removal of ultraviolet filters by ultrafiltration membranes.

    PubMed

    Chen, Xin; Deng, Huiping

    2013-03-01

    Ultraviolet (UV) filters represent a new class of micropollutants in water. To effectively remove these substances and minimize fouling during ultrafiltration, an electro-ultrafiltration process was used to separate benzophenone-3 (BP-3) from water by applying an electric field across the membrane. The effects of the electric field on the filtration performance, including resistance and retention, modification of polyvinylidene fluoride (PVDF) membrane and possible intermediates produced during electro-ultrafiltration, were studied thoroughly. The results clearly indicate that the combination of the electric field with ultrafiltration could increase BP-3 rejection and reduce filtration resistance. The membrane had a rougher surface and the pore size increased due to the modifications of PVDF membrane induced by the electric field. The decrease in contact angle demonstrated the improvement of hydrophilicity in the PVDF membrane surface after the electrofiltration treatment. The mechanism of BP-3 degradation in the electrofiltration was examined theoretically by calculating the frontier electron densities of the BP-3 molecule. The C3 atom in the BP-3 structure was demonstrated to be the most reactive site, which was consistent with the intermediate results identified by gas chromatography-mass spectrometry (GC-MS) analysis. PMID:23237763

  14. Pretreatment of spent sulphite liquor via ultrafiltration and nanofiltration for bio-based succinic acid production.

    PubMed

    Pateraki, Chrysanthi; Ladakis, Dimitrios; Stragier, Lutgart; Verstraete, Willy; Kookos, Ioannis; Papanikolaou, Seraphim; Koutinas, Apostolis

    2016-09-10

    Ultrafiltration and nanofiltration of spent sulphite liquor (SSL) has been employed to evaluate the simultaneous production of lignosulphonates and bio-based succinic acid using the bacterial strains Actinobacillus succinogenes and Basfia succiniciproducens. Ultrafiltration with membranes of 10, 5 and 3kDa molecular weight cut-off results in significant losses of lignosulphonates (26-50%) in the permeate stream, while nanofiltration using membrane with 500Da molecular weight cut-off results in high retention yields of lignosulphonates (95.6%) in the retentate stream. Fed-batch bioreactor cultures using permeates from ultrafiltrated SSL resulted in similar succinic acid concentration (27.5g/L) and productivity (0.4g/L/h) by both strains. When permeates from nanofiltrated SSL were used, the strain B. succiniciproducens showed the highest succinic acid concentration (33.8g/L), yield (0.58g per g of consumed sugars) and productivity (0.48g/L/h). The nanofiltration of 1t of thick spent sulphite liquor could lead to the production of 306.3kg of lignosulphonates and 52.7kg of succinic acid, whereas the ultrafiltration of 1t of thick spent sulphite liquor using a 3kDa membrane could result in the production of 237kg of lignosulphonates and 71.8kg of succinic acid when B. succiniproducens is used in both cases. PMID:27374402

  15. Hemodialysis: evidence of enhanced molecular clearance and ultrafiltration volume by using pulsatile flow.

    PubMed

    Runge, T M; Briceño, J C; Sheller, M E; Moritz, C E; Sloan, L; Bohls, F O; Ottmers, S E

    1993-09-01

    We describe several in vitro experiments showing evidence that pulsatile flow hemodialysis enhances ultrafiltration volume and molecular clearance as compared with steady flow hemodialysis. A new pulsatile pump and a conventional roller pump were compared using different hollow fiber dialyzers and a simulated blood solution containing urea, aspartame and vitamin B-12 at different flow rates and configurations. Ultrafiltration volume and concentration of urea, aspartame and B-12 were measured and molecular clearance (K) calculated. Ultrafiltration volume markedly increased with pulsatile flow. After 10 min K for urea with pulsatile flow was higher in all experiments even when ultrafiltration was prevented. Clearance of aspartame and B-12 also increased with pulsatile flow. We propose three mechanisms by which pulsatile flow is more efficient than steady flow hemodialysis: greater fluid energy, avoidance of molecular channeling and avoidance of membrane layering. We hypothesize that using pulsatile flow in hemodialysis can significantly shorten the duration of dialysis sessions for most of the patients, and consequently reduce the duration of the procedure and its cost.

  16. Integrated downstream processing of lactoperoxidase from milk whey involving aqueous two-phase extraction and ultrasound-assisted ultrafiltration.

    PubMed

    Nandini, K E; Rastogi, Navin K

    2011-01-01

    The present work involves the adoption of an integrated approach for the purification of lactoperoxidase from milk whey by coupling aqueous two-phase extraction (ATPE) with ultrasound-assisted ultrafiltration. The effect of system parameters of ATPE such as type of phase system, polyethylene glycol (PEG) molecular mass, system pH, tie line length and phase volume ratio was evaluated so as to obtain differential partitioning of contaminant proteins and lactoperoxidase in top and bottom phases, respectively. PEG 6000-potassium phosphate system was found to be suitable for the maximum activity recovery of lactoperoxidase 150.70% leading to 2.31-fold purity. Further, concentration and purification of enzyme was attempted using ultrafiltration. The activity recovery and purification factor achieved after ultrafiltration were 149.85% and 3.53-fold, respectively. To optimise productivity and cost-effectiveness of integrated process, influence of ultrasound for the enhancement of permeate flux during ultrafiltration was also investigated. Intermittent use of ultrasound along with stirring (2 min acoustic and 2 min stirring) resulted in increased permeate flux from 0.94 to 2.18 l/m(2) h in comparison to the ultrafiltration without ultrasound. The use of ultrasound during ultrafiltration resulted in increase in flux, but there was no significant change in activity recovery and purification factor. The integrated approach involving ATPE and ultrafiltration may prove to be a feasible method for the downstream processing of lactoperoxidase from milk whey.

  17. Enzyme hydrolysis of plasma proteins in a CSTR ultrafiltration reactor: Performances and modeling.

    PubMed

    Bressollier, P; Petit, J M; Julien, R

    1988-05-01

    By investigating the effects of four operating variables-volume (V), Ultrafiltration flux (J), enzyme concentration (E), and substrate concentration (S)-on capacity (K) and conversion rate (epsilon) of a hollow fiber CSTR, the performances of the CSTR and the kinetic constants of the reaction were determined. A model which takes into account the course of fractional conversion (X) according to the modified space-time parameter, tau (integrated form of V, J, S, and E), was devised by employing the relationship to integrate the equation for the reaction rate of the CSTR and the expression of the modified space time. Correlation of this model and the experimentally obtained results demonstrates that the characteristics for an ultrafiltration membrane reactor for enzymatic hydrolysis by alcalase of plasma proteins are close to those of an ideal CSTR. Optimal scaling up, however, remains dependent on the compromise which may be obtained between capacity and the conversion rate.

  18. Hydrophobic asymmetric ultrafiltration PVDF membranes: an alternative separator for VFB with excellent stability.

    PubMed

    Wei, Wenping; Zhang, Huamin; Li, Xianfeng; Zhang, Hongzhang; Li, Yun; Vankelecom, Ivo

    2013-02-14

    Polyvinylidene fluoride (PVDF) ultrafiltration membranes were investigated for the first time in vanadium redox flow battery (VFB) applications. Surprisingly, PVDF ultrafiltration membranes with hydrophobic pore walls and relatively large pore sizes of several tens of nanometers proved able to separate vanadium ions and protons efficiently, thus being suitable as a VFB separator. The ion selectivity of this new type of VFB membrane could be tuned readily by controlling the membrane morphology via changes in the composition of the membrane casting solution, and the casting thickness. The results showed that the PVDF membranes offered good performances and excellent stability in VFB applications, where it could, performance-wise, truly substitute Nafion in VFB applications, but at a much lower cost. PMID:23223708

  19. Recovery of ionic liquid via a hybrid methodology of electrodialysis with ultrafiltration after biomass pretreatment.

    PubMed

    Liang, Xiaocong; Fu, Yan; Chang, Jie

    2016-11-01

    Hybrid membrane-based methodology of electrodialysis (ED) with ultrafiltration (UF) was employed to recover the IL BmimBr (1-Butyl-3-methylimidazolium bromide) after biomass fractionation. Ultrafiltration was used to remove the residual lignin in IL solutions. Influence of molecular weight interception of UF treatment, initial IL concentration in dilute section, applied voltage and flow rate in each section of ED module were studied in detail. In this study, the highest overall IL recovery ratio reached 75.2% and the current efficiency of ED process approached 79.1%. Besides, the highest IL recovery performance of specific energy consumption was about 514.1g/kw·h. Insight gained from this study suggests a potential methodology for IL recovery after the pretreatment process for biomass. PMID:27589823

  20. Hydrophobic asymmetric ultrafiltration PVDF membranes: an alternative separator for VFB with excellent stability.

    PubMed

    Wei, Wenping; Zhang, Huamin; Li, Xianfeng; Zhang, Hongzhang; Li, Yun; Vankelecom, Ivo

    2013-02-14

    Polyvinylidene fluoride (PVDF) ultrafiltration membranes were investigated for the first time in vanadium redox flow battery (VFB) applications. Surprisingly, PVDF ultrafiltration membranes with hydrophobic pore walls and relatively large pore sizes of several tens of nanometers proved able to separate vanadium ions and protons efficiently, thus being suitable as a VFB separator. The ion selectivity of this new type of VFB membrane could be tuned readily by controlling the membrane morphology via changes in the composition of the membrane casting solution, and the casting thickness. The results showed that the PVDF membranes offered good performances and excellent stability in VFB applications, where it could, performance-wise, truly substitute Nafion in VFB applications, but at a much lower cost.

  1. Preparation of PES ultrafiltration membranes with natural amino acids based zwitterionic antifouling surfaces

    NASA Astrophysics Data System (ADS)

    Xu, Chen; Liu, Xiaojiu; Xie, Binbin; Yao, Chen; Hu, Wenhan; Li, Yi; Li, Xinsong

    2016-11-01

    In this report, a simple and facile approach to enhance the antifouling property of poly(ether sulfone) (PES) ultrafiltration membrane was developed by grafting natural amino acids onto surface. First of all, poly(ether sulfone) composite membranes blended with poly(glycidyl methacrylate) were fabricated by phase inversion method followed by grafting of different types of natural amino acids onto the membrane surface through epoxy ring opening reaction. The analysis of attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FTIR) and X-ray photoelectron spectroscopy (XPS) verified the substantial enrichment of amino acids onto the surface of PES membranes. The hydrophilicity of the PES membranes was improved after grafting amino acids. The mechanical property and morphologies of the PES membranes proved that their basic performances were not obviously affected by grafting reaction, and these parameters were all still in the typical range for ultrafiltration membranes. The antifouling property of the grafted PES membranes against bovine serum albumin (BSA) and lysozyme (Lyz) was investigated in detail. It was found that PES membranes incorporated with neutral amino acids exhibited higher fouling resistance to both BSA and Lyz than the parent PES membrane. It can be ascribed to the formation of zwitterionic structure on the surface consisting of protonated secondary amino cations and carboxyl anions. Meanwhile, PES membranes grafted with charged amino acids had better antifouling properties against protein with same electric charges and improved adsorption related to protein with opposite electric charges. Furthermore, the ultrafiltration performance of the zwitterionic PES membranes was evaluated. The results showed that the modified membranes possessed of enhanced pure water flux, relative flux recovery and mildly lower rejection. The Darcy's Law analysis illustrated that the acidic amino acid grafted PES membranes had much lower permeation

  2. A general diagram for estimating pore size of ultrafiltration and reverse osmosis membranes

    NASA Technical Reports Server (NTRS)

    Sarbolouki, M. N.

    1982-01-01

    A slit sieve model has been used to develop a general correlation between the average pore size of the upstream surface of a membrane and the molecular weight of the solute which it retains by better than 80%. The pore size is determined by means of the correlation using the high retention data from an ultrafiltration (UF) or a reverse osmosis (RO) experiment. The pore population density can also be calculated from the flux data via appropriate equations.

  3. Preparation of ultrafiltration membrane by phase separation coupled with microwave irradiation

    SciTech Connect

    Suryani, Puput Eka; Purnama, Herry; Susanto, Heru

    2015-12-29

    Preparation of low fouling ultrafiltration membrane is still a big challenge in the membrane field. In this paper, polyether sulfone (PES) ultrafiltration membranes were prepared by non-solvent-induced phase separation (NIPS) coupled with microwave irradiation. Polyethylene glycol (PEG) and polyethylene glycol methacrylate (PEGMA) were used as additives to improve membrane hydrophilicity. In this study, the concentration of additive, irradiation time and microwave power was varied. The membranes were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy, while the performances were tested by adsorptive and ultrafiltration fouling experiments. The results show that the irradiation time and irradiation power are very important parameter that influence the membrane characteristic. In addition, type and concentration of additive are other important parameters. The results suggest that microwave irradiation is the most important parameter influencing the membrane characteristic. Both pure water flux and fouling resistance increase with increasing irradiation time, power irradiation, and additive concentration. PES membrane with addition of 10% w/w PEG and irradiated by 130 W microwave power for 180 seconds is the best membrane performance.

  4. Selective separation of Eu{sup 3+} using polymer-enhanced ultrafiltration

    SciTech Connect

    Norton, M.V.

    1994-03-01

    A process to selectively remove {sup 241}Am from liquid radioactive waste was investigated as an actinide separation method applicable to Hanford and other waste sites. The experimental procedures involved removal of Eu, a nonradioactive surrogate for Am, from aqueous solutions at pH 5 using organic polymers in conjunction with ultrafiltration. Commercially available polyacrylic acid (60,000 MW) and Pacific Northwest Laboratory`s (PNL) synthesized E3 copolymer ({approximately}10,000 MW) were tested. Test solutions containing 10 {mu}g/mL of Eu were dosed vath each polymer at various concentrations in order to bind Eu (i.e., by complexation and/or cation exchange) for subsequent rejection by an ultrafiltration coupon. Test solutions were filtered with and without polymer to determine if enhanced Eu separation could be achieved from polymer treatment. Both polymers significantly increased Eu removal. Optimum concentrations were 20 {mu}g/mL of polyacrylic acid and 100 {mu}g/mL of E3 for 100% Eu rejection by the Amicon PM10 membrane at 55 psi. In addition to enhancement of removal, the polymers selectively bound Eu over Na, suggesting that selective separation of Eu was possible. This suggests that polymer-enhanced ultrafiltration is a potential process for separation of {sup 241}Am from Hanford tank waste, further investigation of binding agents and membranes effective under very alkaline and high ionic strength is warranted. This process also has potential applications for selective separation of toxic metals from industrial process streams.

  5. Supported mesoporous carbon ultrafiltration membrane and process for making the same

    DOEpatents

    Strano, Michael; Foley, Henry C.; Agarwal, Hans

    2004-04-13

    A novel supported mesoporous carbon ultrafiltration membrane and process for producing the same. The membranes comprise a mesoporous carbon layer that exists both within and external to the porous support. A liquid polymer precursor composition comprising both carbonizing and noncarbonizing templating polymers is deposited on the porous metal support. The coated support is then heated in an inert-gas atmosphere to pyrolyze the polymeric precursor and form a mesoporous carbon layer on and within the support. The pore-size of the membranes is dependent on the molecular weight of the noncarbonizing templating polymer precursor. The mesoporous carbon layer is stable and can withstand high temperatures and exposure to organic chemicals. Additionally, the porous metal support provides excellent strength properties. The composite structure of the membrane provides novel structural properties and allows for increased operating pressures allowing for greater membrane flow rates. The invention also relates to the use of the novel ultrafiltration membrane to separate macromolecules from solution. An example is shown separating bovine serum albumin from water. The membrane functions by separating and by selective adsorption. Because of the membrane's porous metal support, it is well suited to industrial applications. The unique properties of the supported mesoporous carbon membrane also allow the membrane to be used in transient pressure or temperature swing separations processes. Such processes were not previously possible with existing mesoporous membranes. The present invention, however, possesses the requisite physical properties to perform such novel ultrafiltration processes.

  6. Preparation of ultrafiltration membrane by phase separation coupled with microwave irradiation

    NASA Astrophysics Data System (ADS)

    Suryani, Puput Eka; Purnama, Herry; Susanto, Heru

    2015-12-01

    Preparation of low fouling ultrafiltration membrane is still a big challenge in the membrane field. In this paper, polyether sulfone (PES) ultrafiltration membranes were prepared by non-solvent-induced phase separation (NIPS) coupled with microwave irradiation. Polyethylene glycol (PEG) and polyethylene glycol methacrylate (PEGMA) were used as additives to improve membrane hydrophilicity. In this study, the concentration of additive, irradiation time and microwave power was varied. The membranes were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy, while the performances were tested by adsorptive and ultrafiltration fouling experiments. The results show that the irradiation time and irradiation power are very important parameter that influence the membrane characteristic. In addition, type and concentration of additive are other important parameters. The results suggest that microwave irradiation is the most important parameter influencing the membrane characteristic. Both pure water flux and fouling resistance increase with increasing irradiation time, power irradiation, and additive concentration. PES membrane with addition of 10% w/w PEG and irradiated by 130 W microwave power for 180 seconds is the best membrane performance.

  7. Plasma ultrafiltrates from Fanconi Anemia patients induces chromosomal breakages in donor lymphocytes

    SciTech Connect

    Emerit, I.; Levy, A.; Pagano, G.

    1994-09-01

    The present study investigated the occurrence, if any, of transferable clastogenic activity in the plasma from Fanconi Anemia (FA) patients and their families. A total of 13 FA homozygotes, 25 parents, and 12 siblings were studied for their: (a) spontaneous and DEB-induced chromosomal instability, and (b) induction of chromosomal breaks in peripheral blood lymphocytes (PBL) from healthy donors, following exposure to plasma ultrafiltrates from FA subjects, their parents or siblings. Plasma was ultrafiltered through membranes with a cutoff at 10,000 daltons (YM 10 Amicon) and 0.25 ml-aliquote added to PBL from 14 healthy donors. DEB test provided FA confirmatory diagnosis. The occurrence of clastogenic factors (CF) was evident in all FA patients, except for one. In two out of three patients, who died during this study, very high CF levels were observed. Clastogenic activity was significantly higher in male than in female patients (p<0.05). No correlation was observed between CF data and spontaneous or DEB-induced chromosomal instability. Ultrafiltrates from parents and siblings showed less CF than FA homozygotes; however, concentration by ultrafiltration through YM 2 (3x to 5x) led to excess clastogenic activity. The control plasmas were lacking CF even after an 8x concentration. The present data suggest that CF formation in the plasma of FA patients is consistent with an in vivo prooxident state in FA.

  8. Enhanced starch hydrolysis using α-amylase immobilized on cellulose ultrafiltration affinity membrane.

    PubMed

    Konovalova, Viktoriia; Guzikevich, Kateryna; Burban, Anatoliy; Kujawski, Wojciech; Jarzynka, Karolina; Kujawa, Joanna

    2016-11-01

    In order to prepare ultrafiltration membranes possessing biocatalytic properties, α-amylase has been immobilized on cellulose membranes. Enzyme immobilization was based on a covalent bonding between chitosan and a surface of cellulose membrane, followed by an attachment of Cibacron Blue F3G-A dye as affinity ligand. Various factors affecting the immobilization process, such as enzyme concentration, pH of modifying solution, zeta-potential of membrane surface, and stability of immobilized enzyme were studied. The applicability of immobilized α-amylase has been investigated in ultrafiltration processes. The immobilization of α-amylase on membrane surface allows to increase the value of mass transfer coefficient and to decrease the concentration polarization effect during ultrafiltration of starch solutions. The enzyme layer on the membrane surface prevents a rapid increase of starch concentration due to the amylase hydrolysis of starch in the boundary layer. The presented affinity immobilization technique allows also for the regeneration of membranes from inactivated enzyme. PMID:27516322

  9. Application of ultrafiltration in the pulp and paper industry: metals removal and whitewater reuse.

    PubMed

    Oliveira, C R; Silva, C M; Milanez, A F

    2007-01-01

    In the pulp and paper industry, the water use minimization is a constant target. One way to reduce water use is to recycle the effluent in a closed-cycle concept. In paper mills, the main source of liquid effluent is the so-called whitewater, which is the excess water, originated from pulp stock dewatering and other fibre contaminated water. This research studied the reuse of paper mill whitewater after membrane ultrafiltration (UF) in the paper machine and in the pulp bleach plant of an integrated mill. Contaminant removal and flux behaviour of the UF system were evaluated. The treatment by ultrafiltration was technically feasible and the treated whitewater had good potential to be reused in some processes in the paper machine. The reuse of ultrafiltered whitewater in the bleaching plant was not recommended because of the high level of soluble calcium present in this stream. Therefore, a combined treatment of the whitewater using the principle of precipitation and ultrafiltration was proposed showing good results and enabling the use of the treated whitewater in the bleach plant.

  10. Structure and activity of a new low-molecular-weight heparin produced by enzymatic ultrafiltration.

    PubMed

    Fu, Li; Zhang, Fuming; Li, Guoyun; Onishi, Akihiro; Bhaskar, Ujjwal; Sun, Peilong; Linhardt, Robert J

    2014-05-01

    The standard process for preparing the low-molecular-weight heparin (LMWH) tinzaparin, through the partial enzymatic depolymerization of heparin, results in a reduced yield because of the formation of a high content of undesired disaccharides and tetrasaccharides. An enzymatic ultrafiltration reactor for LMWH preparation was developed to overcome this problem. The behavior, of the heparin oligosaccharides and polysaccharides using various membranes and conditions, was investigated to optimize this reactor. A novel product, LMWH-II, was produced from the controlled depolymerization of heparin using heparin lyase II in this optimized ultrafiltration reactor. Enzymatic ultrafiltration provides easy control and high yields (>80%) of LMWH-II. The molecular weight properties of LMWH-II were similar to other commercial LMWHs. The structure of LMWH-II closely matched heparin's core structural features. Most of the common process artifacts, present in many commercial LWMHs, were eliminated as demonstrated by 1D and 2D nuclear magnetic resonance spectroscopy. The antithrombin III and platelet factor-4 binding affinity of LMWH-II were comparable to commercial LMWHs, as was its in vitro anticoagulant activity.

  11. Modular extracorporeal life support: effects of ultrafiltrate recirculation on the performance of an extracorporeal carbon dioxide removal device.

    PubMed

    Scaravilli, Vittorio; Kreyer, Stefan; Linden, Katharina; Belenkiy, Slava; Jordan, Bryan; Pesenti, Antonio; Zanella, Alberto; Chung, Kevin; Cannon, Jeremy; Cancio, Leopoldo C; Batchinsky, Andriy I

    2014-01-01

    The combination of extracorporeal carbon dioxide removal (ECCO2R) and hemofiltration is a possible therapeutic strategy for patients needing both lung and renal support. We tested the effects of the recirculation of ultrafiltrate on membrane lung (ML) CO2 removal (VCO2ML). Three conscious, spontaneously breathing sheep were connected to a commercially produced ECCO2R device (Hemolung; Alung Technologies, Pittsburgh, PA) with a blood flow of 250 ml/min and a gas flow of 10 L/min. A hemofilter (NxStage, NxStage Medical, Lawrence, MA) was interposed in series after the ML. Ultrafiltrate flow was generated and recirculated before the ML. We tested four ultrafiltrate flows (0, 50, 100, and 150 ml/min) for 25 min each, eight times per animal, resulting in 24 randomized test repetitions. We recorded VCO2ML, hemodynamics and ventilatory variables, and natural lung CO2 transfer (VCO2NL) and collected arterial and circuitry blood samples. VCO2ML was unchanged by application of ultrafiltrate recirculation (40.5 ± 4.0, 39.7 ± 4.2, 39.8 ± 4.2, and 39.2 ± 4.1 ml/min, respectively, at ultrafiltrate flow of 0, 50, 100, and 150 ml/min). Minute ventilation, respiratory rate, VCO2NL, and arterial blood analyses were not affected by ultrafiltrate recirculation. In the tested configuration, ultrafiltrate recirculation did not affect VCO2ML. This modular technology may provide a suitable platform for coupling CO2 removal with various forms of blood purification.

  12. Investigation of conventional membrane and tangential flow ultrafiltration artifacts and their application to the characterization of freshwater colloids.

    PubMed

    Morrison, Matthew A; Benoit, Gaboury

    2004-12-15

    Artifacts associated with the fractionation of colloids in a freshwater sample were investigated for conventional membrane filtration (0.45 microm cutoff), and two tangential flow ultrafiltration cartridges (0.1 microm cutoff and 3000 MW cutoff). Membrane clogging during conventional filtration removed some colloids smaller than 0.1 microm in diameter, much smaller than the nominal size of the filter. For certain constituents (e.g., Fe), filter clogging had a significant effect on filtrate concentrations, while artifacts associated with tangential flow ultrafiltration using a 0.1 microm cutoff were minimal. Artifacts occurred during tangential flow ultrafiltration with a 3000 MW cutoff, but did not deviate from predicted changes in concentration based on a standard permeation model. Comparison of filtrate concentrations for membrane filtration (at 1.0 and 0.45 microm) and tangential flow ultrafiltration (at 0.1 microm) for a large number of samples from Connecticut rivers shows that significant and consistent differences exist between their separation characteristics. Results for organic carbon, Fe, Mn, Al, Cu, and Pb demonstrate the magnitude of the effects of the fractionation technique on filtrate element concentration, show variability by element and flow condition, and highlight the importance of larger colloids to freshwater metal speciation. One implication of the research is that tangential flow ultrafiltration with large size cutoff membranes (e.g., approximately 0.1 microm) may be superior to conventional filtration with filters in the same size discrimination range, and potentially more appropriate for the fractionation of natural water samples.

  13. Effects of zero-balanced ultrafiltration on procalcitonin and respiratory function after cardiopulmonary bypass.

    PubMed

    Song, L O U; Yinglong, L I U; Jinping, L I U

    2007-09-01

    The abnormal conditions to which blood is subjected during cardiopulmonary bypass (CPB) trigger an activation of the inflammatory response and cause pulmonary dysfunction. It has been suggested that high-volume, zero-balanced ultrafiltration (ZBUF) facilitates clearance of inflammatory mediators and improves post-operative pulmonary function. Procalcitonin, a newly discovered inflammatory mediator, has been found to be increased after CPB and has been proven to be an appropriate parameter for predicting pulmonary dysfunction secondary to CPB. The aim of this study was to investigate the effects of zero-balanced ultrafiltration (ZBUF) on procalcitonin (PCT) and respiratory function of infants with Tetralogy of Fallot (TOF) after CPB. Twenty infants with TOF undergoing open-heart total surgical correction were randomly assigned to two groups. The trial group was given ZBUF (50 ml/kg) and conventional ultrafiltration (CUF), while the control group was given CUF only. Plasma PCT and pulmonary function were monitored and compared between the two groups before the operation (T1), before rewarming (T2), at the end of the operation (T3), and at 12 h, 24 h and 48 h after the operation (T4-T6). PCT was decreased in the trial group between 12 h and 48 h post-operatively, but the differences did not reach statistical significance. The trial group's pulmonary compliance was higher at 12 h post-operatively (p < 0.05). Oxygenation index was increased in the trial group at the end of the operation and 12 h post-operatively (p > 0.05). Intubation time was shorter in the trial group (P < 0.01). A positive correlation was found between peak PCT concentration and intubation time. ZBUF appeared to improve ventilation and shorten intubation time. The improved respiratory function may be due to the lower plasma PCT. PMID:18416220

  14. Fouling and cleaning characteristics of ultrafiltration of hydrophobic dissolved organic matter by a polyvinyl chloride hollow fiber membrane.

    PubMed

    Guo, Xiaoyan; Gao, Wei; Li, Jihui; Hu, Wanli

    2009-06-01

    Ultrafiltration membrane fouling is a significant problem in drinking water treatment. Many researchers believe that hydrophobic natural organic matter is the main foulant. In this research, fulvic acid, tannin, and aniline were used to represent hydrophobic acid, neutral, and base, respectively, to investigate modified polyvinyl chloride ultrafiltration membrane fouling characteristics. Four kinds of cleaning methods were used in this study: flushing, backwashing, flushing and backwashing, and chemical cleaning with 0.5% sodium hydroxide. Each was performed on the three hydrophobic dissolved organic matters (acid, neutral, and base) to identify the fouling mechanisms of polyvinyl chloride ultrafiltration membrane. Results showed that hydrophobic base fouled membranes the most and hydrophobic acid the least based on cleaning difficulty.

  15. [Diuretic resistance and mechanical ventilation in decompensated cor pulmonale: successful treatment by slow continuous ultrafiltration].

    PubMed

    Ries, W; Schenzer, A; Lüken, J; Ries, C; Machraoui, A

    2012-08-01

    We report on a 53-year-old male patient who presented with severe dyspnea at rest and massive volume overload because of decompensated cor pulmonale. Furthermore he suffered from stage 3 chronic kidney disease. As there was diuretics resistance and carbon dioxide narcosis, he had to be intubated and ventilated. The massive volume overload could be successfully treated with slow continuous ultrafiltration (SCUF) with removal of a volume of 27.5 l within 3 days. The SCUF therapy is an effective and gentle method to treat even an excessive volume overload based on diuretics resistance.

  16. Improving the antifouling property of polysulfone ultrafiltration membrane by incorporation of isocyanate-treated graphene oxide.

    PubMed

    Zhao, Haiyang; Wu, Liguang; Zhou, Zhijun; Zhang, Lin; Chen, Huanlin

    2013-06-21

    In this paper, isocyanate-treated graphene oxide (iGO), which can be well dispersed in organic solvent, was prepared in a simple manner and showed excellent compatibility with polysulfone (PSF). iGO-PSF ultrafiltration membranes were prepared by the classical phase inversion method. The separation performance and the antifouling property of the prepared membranes were investigated in detail. The antifouling property of the prepared membranes was found to be greatly enhanced by the addition of iGO, and we attributed the enhanced antifouling property to the improved hydrophilicity, the more negative zeta potential and the improved smoothness of the membrane surface.

  17. Investigation of ultrafiltration rejection of surfactant micelles by dynamic light scattering

    SciTech Connect

    Singh, R.

    1996-05-01

    The absence of nonionic surfactant micelles in ultrafiltration membrane (molecular weight cut-off = 10,000) permeates is verified with the aid of a dynamic light-scattering (DLS) technique. DLS is also used to determine the hydrodynamic radii of micelles at concentrations above the critical micelle concentration. An empirical relationship between the micelle diameter, diffusion coefficient, and a pseudomolecular weight is plotted. The relationship can be used to screen high molecular weight cut-off membranes for surfactant-based UF applications.

  18. Effect of enhanced coagulation by KMnO(4) on the fouling of ultrafiltration membranes.

    PubMed

    Yu, Wen-Zheng; Gregory, John; Liu, Ting; Yang, Yan-lin; Sun, Min; Li, Gui-bai

    2011-01-01

    Pre-coagulation enhanced by KMnO(4) before ultrafiltration (KCUF) was compared with normal pre-coagulation by alum (CUF) in the ultrafiltration of water from the Songhua River, China. The trans-membrane pressure (TMP) with KCUF was much lower than that when alum alone was used. With KCUF a slower increment of TMP occurred, even under conditions of high river water turbidity. The results also showed that the removal of COD, UV(254) and TOC was appreciably higher after adding 0.5mg/L KMnO(4) compared with CUF. Although assimilable organic carbon (AOC) was increased by permanganate treatment, the AOC of the permeate from KCUF was nearly the same as that from CUF, showing that the cake layer on the surface of KCUF membrane could adsorb small molecules more effectively than that of CUF. This result was confirmed by the apparent molecular weight (MW) distribution measured by size exclusion chromatography (SEC). It was shown that flocs formed by KMnO(4) and alum were larger than those formed only by alum, causing higher removal of flocs and higher permeation flux. Lower NOM was found in the permeate from the KCUF systems because oxidation and adsorption of organic matter on the flocs occurred. The membrane was partly clogged by organic matter or other materials including some small flocs.

  19. A hybrid microbial fuel cell membrane bioreactor with a conductive ultrafiltration membrane biocathode for wastewater treatment.

    PubMed

    Malaeb, Lilian; Katuri, Krishna P; Logan, Bruce E; Maab, Husnul; Nunes, S P; Saikaly, Pascal E

    2013-10-15

    A new hybrid, air-biocathode microbial fuel cell-membrane bioreactor (MFC-MBR) system was developed to achieve simultaneous wastewater treatment and ultrafiltration to produce water for direct reclamation. The combined advantages of this system were achieved by using an electrically conductive ultrafiltration membrane as both the cathode and the membrane for wastewater filtration. The MFC-MBR used an air-biocathode, and it was shown to have good performance relative to an otherwise identical cathode containing a platinum catalyst. With 0.1 mm prefiltered domestic wastewater as the feed, the maximum power density was 0.38 W/m(2) (6.8 W/m(3)) with the biocathode, compared to 0.82 W/m(2) (14.5 W/m(3)) using the platinum cathode. The permeate quality from the biocathode reactor was comparable to that of a conventional MBR, with removals of 97% of the soluble chemical oxygen demand, 97% NH3-N, and 91% of total bacteria (based on flow cytometry). The permeate turbidity was <0.1 nephelometric turbidity units. These results show that a biocathode MFC-MBR system can achieve high levels of wastewater treatment with a low energy input due to the lack of a need for wastewater aeration. PMID:24016059

  20. Coupling of ultrafiltration and enzymatic hydrolysis aiming at valorizing shrimp wastewater.

    PubMed

    Tonon, Renata V; dos Santos, Bianca A; Couto, Cinthia C; Mellinger-Silva, Caroline; Brígida, Ana Iraidy S; Cabral, Lourdes M C

    2016-05-01

    The objective of this work was to obtain a protein hydrolysate from the wastewater generated during shrimp cooking, by coupling ultrafiltration and enzymatic hydrolysis processes. Initially, the effluent was concentrated by ultrafiltration, reaching a protein concentration factor of 3.2. The concentrated effluent was then enzymatically hydrolyzed, aiming at obtaining peptides with antioxidant capacity. The effects of some process variables--temperature (55-75 °C), pH (7-9) and enzyme/substrate (E/S) ratio (0.1-2.5%)--on the degree of hydrolysis and the antioxidant capacity were evaluated. The increase in temperature and pH resulted in lower degree of hydrolysis and higher antioxidant capacity. The conditions selected as the most suitable were: temperature of 75 °C, pH of 9.0 and E/S ratio of 0.1%. The hydrolysates produced at these conditions were also evaluated for total amino acid content and electrophoretic profile, showing a suitable amount of essential amino acids that covers the recommended daily needs.

  1. Pilot-scale investigation of drinking water ultrafiltration membrane fouling rates using advanced data analysis techniques.

    PubMed

    Chen, Fei; Peldszus, Sigrid; Peiris, Ramila H; Ruhl, Aki S; Mehrez, Renata; Jekel, Martin; Legge, Raymond L; Huck, Peter M

    2014-01-01

    A pilot-scale investigation of the performance of biofiltration as a pre-treatment to ultrafiltration for drinking water treatment was conducted between 2008 and 2010. The objective of this study was to further understand the fouling behaviour of ultrafiltration at pilot scale and assess the utility of different foulant monitoring tools. Various fractions of natural organic matter (NOM) and colloidal/particulate matter of raw water, biofilter effluents, and membrane permeate were characterized by employing two advanced NOM characterization techniques: liquid chromatography - organic carbon detection (LC-OCD) and fluorescence excitation-emission matrices (FEEM) combined with principal component analysis (PCA). A framework of fouling rate quantification and classification was also developed and utilized in this study. In cases such as the present one where raw water quality and therefore fouling potential vary substantially, such classification can be considered essential for proper data interpretation. The individual and combined contributions of various NOM fractions and colloidal/particulate matter to hydraulically reversible and irreversible fouling were investigated using various multivariate statistical analysis techniques. Protein-like substances and biopolymers were identified as major contributors to both reversible and irreversible fouling, whereas colloidal/particulate matter can alleviate the extent of irreversible fouling. Humic-like substances contributed little to either reversible or irreversible fouling at low level fouling rates. The complementary nature of FEEM-PCA and LC-OCD for assessing the fouling potential of complex water matrices was also illustrated by this pilot-scale study.

  2. Equilibrium dialysis and ultrafiltration investigations of perchlorate removal from aqueous solution using poly(diallyldimethylammonium) chloride.

    PubMed

    Roach, Jim D; Tush, Daniel

    2008-02-01

    Use of perchlorate salts in military activities and the aerospace industry is widespread. These salts are highly water-soluble and are, to a large extent, kinetically inert as aqueous species. As a groundwater contaminant, perchlorate is now being detected in an increasing number of locations and is believed to interfere with the uptake of iodide by the thyroid, which can result in decreased hormone production. The United States Environmental Protection Agency (US EPA) has established a reference dose for perchlorate of 0.0007 mg/kg/day, which translates to a drinking water equivalent level of 24.5 ppb. This study investigated the application of polyelectrolyte-enhanced ultrafiltration (PEUF) for the selective removal of perchlorate from aqueous solution through equilibrium dialysis and ultrafiltration experiments. Using poly(diallyldimethylammonium) chloride, the effectiveness and efficiency of PEUF in the removal of perchlorate from other aqueous solution components was investigated by testing parameters such as polyelectrolyte concentration, pH, and ionic strength. Removal of perchlorate from synthetic groundwater initially containing 10.3 ppm perchlorate and also containing chloride, sulfate, and carbonate was also examined. Perchlorate separations of greater than 95% were achieved, even in the presence of 10-fold excesses of competing ions. PMID:17915279

  3. Fractionation of sugar beet pulp into pectin, cellulose, and arabinose by arabinases combined with ultrafiltration.

    PubMed

    Spagnuolo, M; Crecchio, C; Pizzigallo, M D; Ruggiero, P

    1999-09-20

    Incubation of beet pulp with two arabinases (alpha-L-arabinofuranosidase and endo-arabinase), used singularly or in combination at different units of activity per gram of beet pulp, caused the hydrolysis of arabinan, which produced a hydrolyzate consisting mainly of arabinose. Pectin and a residue enriched with cellulose were subsequently separated from the incubation mixture. The best enzymatic hydrolysis results were obtained when 100 U/g of beet pulp of each enzyme worked synergistically with yields of 100% arabinose and 91.7% pectin. These yields were higher than those obtained with traditional chemical hydrolysis. The pectin fraction showed a low content of neutral sugar content and the cellulose residue contained only a small amount of pentoses. Semicontinuous hydrolysis with enzyme recycling in an ultrafiltration unit was also carried out to separate arabinose, pectin, and cellulose from beet pulp in 7 cycles of hydrolysis followed by ultrafiltration. The yields of separation were similar to those obtained in batch experiments, with an enzyme consumption reduced by 3.5 times and some significant advantages over batch processes.

  4. Effect of PAC addition on immersed ultrafiltration for the treatment of algal-rich water.

    PubMed

    Zhang, Yan; Tian, Jiayu; Nan, Jun; Gao, ShanShan; Liang, Heng; Wang, Meilian; Li, Guibai

    2011-02-28

    The aim of this study was to evaluate the effect of powdered activated carbon (PAC) addition on the treatment of algal-rich water by immersed ultrafiltration (UF), in terms of permeate quality and membrane fouling. Experiments were performed with a hollow-fiber polyvinyl chloride ultrafiltration membrane at a laboratory scale, 20-25°C and 10 L/(m(2) h) constant permeate flux. UF could achieve an absolute removal of Microcystis aeruginosa cells, but a poor removal of algogenic organic matter (AOM) released into water, contaminants responsible for severe membrane fouling. The addition of 4 g/L PAC to the immersed UF reactor significantly alleviated the development of trans-membrane pressure and enhanced the removal of dissovled organic carbon (by 10.9±1.7%), UV(254) (by 27.1±1.7%), and microcystins (expressed as MC-LR(eq), by 40.8±4.2%). However, PAC had little effect on the rejection of hydrophilic high molecular weight AOM such as carbohydrates and proteins. It was also identified that PAC reduced the concentrations of carbohydrates and proteins in the reactor due to decreased light intensity, as well as the MC-LR(eq) concentration by PAC adsorption. PMID:21216530

  5. Fractionation of sugar beet pulp into pectin, cellulose, and arabinose by arabinases combined with ultrafiltration

    SciTech Connect

    Spangnuolo, M.; Crecchio, C.; Pizzigallo, M.D.R.; Ruggiero, P.

    1999-09-20

    Incubation of beet pulp with two arabinases ({alpha}-L-arabinofuranosidase and endo-arabinase), used singularly or in combination at different units of activity per gram of beet pulp, caused the hydrolysis of arabinasn, which produced a hydrolyzate consisting mainly of arabinose. Pectin and a residue enriched with cellulose were subsequently separated from the incubation mixture. The best enzymatic hydrolysis results were obtained when 100 U/g of beet pulp of each enzyme worked synergistically with yields of 100% arabinose and 91.7% pectin. These yields were higher than those obtained with traditional chemical hydrolysis. The pectin fraction showed a low content of neutral sugar content and the cellulose residue contained only a small amount of pentoses. Semicontinuous hydrolysis with enzyme recycling in an ultrafiltration unit was also carried out to separate arabinose, pectin, and cellulose from beet pulp in 7 cycles of hydrolysis followed by ultrafiltration. The yields of separation were similar to those obtained in batch experiments, with an enzyme consumption reduced by 3.5 times and some significant advantages over batch processes.

  6. Evaluation of an Ultrafiltration-Based Procedure for Simultaneous Recovery of Diverse Microbes in Source Waters

    PubMed Central

    Kahler, Amy M.; Johnson, Trisha B.; Hahn, Donghyun; Narayanan, Jothikumar; Derado, Gordana; Hill, Vincent R.

    2015-01-01

    In this study, hollow-fiber ultrafiltration (UF) was assessed for recovery of Escherichia coli, Clostridium perfringens spores, Cryptosporidium parvum oocysts, echovirus 1, and bacteriophages MS2 and ΦX174 from ground and surface waters. Microbes were seeded into twenty-two 50-L water samples that were collected from the Southeastern United States and concentrated to ∼500 mL by UF. Secondary concentration was performed for C. parvum by centrifugation followed by immunomagnetic separation. Secondary concentration for viruses was performed using centrifugal ultrafilters or polyethylene glycol precipitation. Nine water quality parameters were measured in each water sample to determine whether water quality data correlated with UF and secondary concentration recovery efficiencies. Average UF recovery efficiencies were 66%–95% for the six enteric microbes. Average recovery efficiencies for the secondary concentration methods were 35%–95% for C. parvum and the viruses. Overall, measured water quality parameters were not significantly associated with UF recovery efficiencies. However, recovery of ΦX174 was negatively correlated with turbidity. The recovery data demonstrate that UF can be an effective method for concentrating diverse microbes from ground and surface waters. This study highlights the utility of tangential-flow hollow fiber ultrafiltration for recovery of bacteria, viruses, and parasites from large volume environmental water samples. PMID:26530003

  7. A hybrid microbial fuel cell membrane bioreactor with a conductive ultrafiltration membrane biocathode for wastewater treatment.

    PubMed

    Malaeb, Lilian; Katuri, Krishna P; Logan, Bruce E; Maab, Husnul; Nunes, S P; Saikaly, Pascal E

    2013-10-15

    A new hybrid, air-biocathode microbial fuel cell-membrane bioreactor (MFC-MBR) system was developed to achieve simultaneous wastewater treatment and ultrafiltration to produce water for direct reclamation. The combined advantages of this system were achieved by using an electrically conductive ultrafiltration membrane as both the cathode and the membrane for wastewater filtration. The MFC-MBR used an air-biocathode, and it was shown to have good performance relative to an otherwise identical cathode containing a platinum catalyst. With 0.1 mm prefiltered domestic wastewater as the feed, the maximum power density was 0.38 W/m(2) (6.8 W/m(3)) with the biocathode, compared to 0.82 W/m(2) (14.5 W/m(3)) using the platinum cathode. The permeate quality from the biocathode reactor was comparable to that of a conventional MBR, with removals of 97% of the soluble chemical oxygen demand, 97% NH3-N, and 91% of total bacteria (based on flow cytometry). The permeate turbidity was <0.1 nephelometric turbidity units. These results show that a biocathode MFC-MBR system can achieve high levels of wastewater treatment with a low energy input due to the lack of a need for wastewater aeration.

  8. Characterization and ultrafiltration of semiconductor indium phosphide (InP) wastewater for recycling.

    PubMed

    Wu, M; Sun, D D; Tay, J H

    2005-01-01

    This research work investigated the physical and chemical properties of a new type of wastewater produced from the semiconductor industry. The wastewater generated from indium phosphide (InP) wafer backgrinding and sawing processes was characterized in term of its particle size distribution (PSD), zeta potential, suspended and dissolved solids, total organic carbon, and turbidity. The wastewater contained high concentration of fine InP dusts with a size ranging from 0.07 - 1.44 mm. In spite of its high concentration of suspended solids resulting in high turbidity up to 371 NTU, the wastewater contained very low organic matters (TOC < 2.2 mg l(-1)) and other inorganic impurities (SO4(2-) < 0.21 mg l(-1) and Na+ < 0.16 mg l(-1)). Based on the experimental data collected, the treatment technologies using chemical precipitation and ultrafiltration were applied to the wastewater. Both processes could effectively remove InP particles from the wastewater, however the coagulants in chemical precipitation introduced other ionic contents into the process resulting in difficulties of water recycling in the later stage. In comparison, ultrafiltration was more promising for InP wastewater treatment and recycling. Based on the results of this study, a full-scale UF system was built in a local semiconductor plant and it has successfully reclaimed water from the InP wastes for the past six months without any quality issue being raised.

  9. Polyacrylonitrile-based zwitterionic ultrafiltration membrane with improved anti-protein-fouling capacity

    NASA Astrophysics Data System (ADS)

    Meng, Hong; Cheng, Qiang; Li, Chunxi

    2014-06-01

    The adhesion of proteins to the surface and pores of ultrafiltration membrane is one of the most important causes of membrane fouling, consequently lead to deterioration of membrane performance. In the present study, a polyacrylonitrile (PAN)-based zwitterionic ultrafiltration membrane was developed to improve its anti-protein-fouling capacity. 3-Dimethylaminopropylamine was first grafted onto the hydrolyzed PAN membrane by activation. Subsequently, carboxylic zwitterions were produced on the membrane surface by quaternization with 3-bromopropionic acid. The zwitterionic membranes were rigorously characterized in terms of chemical composition, morphology, and surface properties indicating that the zwitterion could successfully be bonded onto the PAN membrane without having significant effects on the membrane morphology. The anti-protein-fouling properties of the membrane were tested using static protein adsorption and dynamic-filtration experiments. The experimental results show that, although the hydrophilicity of the zwitterionic membrane decreased, the flux recovery rate of the zwitterion-grafted membrane was much higher than that of the hydrolyzed PAN membrane. Therefore, the formation of zwitterionic hydration layer may effectively prevent the adsorption interaction between protein and membrane surface, which is beneficial for the improvement of the anti-protein-fouling capacity.

  10. Pre-treatment for ultrafiltration: effect of pre-chlorination on membrane fouling

    PubMed Central

    Yu, Wenzheng; Xu, Lei; Graham, Nigel; Qu, Jiuhui

    2014-01-01

    Microbial effects are believed to be a major contributor to membrane fouling in drinking water treatment. Sodium hypochlorite (NaClO) is commonly applied in membrane cleaning, but its potential use as a pretreatment for controlling operational fouling has received little attention. In this study, the effect of adding a continuous low dose of NaClO (1 mg/l as active Cl) in combination with alum, before ultrafiltration, was compared with only alum as pretreatment. The results showed that the addition of NaClO substantially reduced membrane fouling both in terms of the rate of TMP development and the properties of the membrane cake layer. Although the size of nano-scale primary coagulant flocs changed little by the addition of NaClO, the cake layer on the membrane had a greater porosity and a substantially reduced thickness. NaClO was found to inactivate bacteria in the influent flow, which reduced both microbial proliferation and the production of proteins and polysaccharides in the cake layer and contributed significantly to improving the overall ultrafiltration performance. NaClO dosing had no adverse impact on the formation of currently regulated disinfection by-product compounds (THMs and HAAs). PMID:25269375

  11. Pre-treatment for ultrafiltration: effect of pre-chlorination on membrane fouling

    NASA Astrophysics Data System (ADS)

    Yu, Wenzheng; Xu, Lei; Graham, Nigel; Qu, Jiuhui

    2014-10-01

    Microbial effects are believed to be a major contributor to membrane fouling in drinking water treatment. Sodium hypochlorite (NaClO) is commonly applied in membrane cleaning, but its potential use as a pretreatment for controlling operational fouling has received little attention. In this study, the effect of adding a continuous low dose of NaClO (1 mg/l as active Cl) in combination with alum, before ultrafiltration, was compared with only alum as pretreatment. The results showed that the addition of NaClO substantially reduced membrane fouling both in terms of the rate of TMP development and the properties of the membrane cake layer. Although the size of nano-scale primary coagulant flocs changed little by the addition of NaClO, the cake layer on the membrane had a greater porosity and a substantially reduced thickness. NaClO was found to inactivate bacteria in the influent flow, which reduced both microbial proliferation and the production of proteins and polysaccharides in the cake layer and contributed significantly to improving the overall ultrafiltration performance. NaClO dosing had no adverse impact on the formation of currently regulated disinfection by-product compounds (THMs and HAAs).

  12. Appropriateness of mechanistic and non-mechanistic models for the application of ultrafiltration to mixed waste

    SciTech Connect

    Foust, Henry; Ghosehajra, Malay

    2007-07-01

    This study asks two questions: (1) How appropriate is the use of a basic filtration equation to the application of ultrafiltration of mixed waste, and (2) How appropriate are non-parametric models for permeate rates (volumes)? To answer these questions, mechanistic and non-mechanistic approaches are developed for permeate rates and volumes associated with an ultrafiltration/mixed waste system in dia-filtration mode. The mechanistic approach is based on a filtration equation which states that t/V vs. V is a linear relationship. The coefficients associated with this linear regression are composed of physical/chemical parameters of the system and based the mass balance equation associated with the membrane and associated developing cake layer. For several sets of data, a high correlation is shown that supports the assertion that t/V vs. V is a linear relationship. It is also shown that non-mechanistic approaches, i.e., the use of regression models to are not appropriate. One models considered is Q(p) = a*ln(Cb)+b. Regression models are inappropriate because the scale-up from a bench scale (pilot scale) study to full-scale for permeate rates (volumes) is not simply the ratio of the two membrane surface areas. (authors)

  13. INVESTIGATION OF CONVENTIONAL MEMBRANE AND TANGENTIAL FLOW ULTRAFILTRATION ARTIFACTS AND THEIR APPLICATION TO THE CHARACTERIZATION OF FRESHWATER COLLOIDS

    EPA Science Inventory

    Artifacts associated with the fractionation of colloids in a freshwater sample were investigated for conventional membrane filtration (0.45 micron cutoff), and two tangential flow ultrafiltration cartridges (0.1 micron cutoff and 3000 MW cutoff). Membrane clogging during conventi...

  14. Cascade ultrafiltration and competing ligand exchange for kinetic speciation of aluminium, iron, and nickel in fresh water.

    PubMed

    Hassan, Nouri M; Murimboh, John D; Sekaly, Amina L R; Mandal, Rupasri; Chakrabarti, Chuni L; Grégoire, D Conrad

    2006-04-01

    Kinetic speciation of nickel, aluminium, and iron in fresh water has been investigated by cascade ultrafiltration followed by competing ligand exchange of the ultrafiltered fractions. Graphite furnace atomic absorption spectrometry was used to measure the kinetics of metal complex dissociation. Dissolved metal species were fractionated by cascade ultrafiltration. Metal speciation in each ultrafiltered fraction was then characterized as free metal ions, "labile" metal complexes (with dissociation rate constants >/=10(-3) s(-1)), "slowly labile" metal complexes (with dissociation rate constants >10(-6) s(-1)), and "inert" metal complexes (with dissociation rate constants <10(-6) s(-1)). The experimental results were compared with the predictions of a computer-based equilibrium speciation model, the Windermere humic aqueous model (WHAM) V. Cascade ultrafiltration coupled with kinetic speciation of the metal species in each molecular weight cut-off (MWCO) fraction provided a more comprehensive picture and insight into the physical and the chemical characteristics of the metal species than either ultrafiltration or measurement of dissociation kinetics alone.

  15. A high-performance liquid chromatographic assay with improved selectivity for cisplatin and active platinum (II) complexes in plasma ultrafiltrate.

    PubMed

    Andrews, P A; Wung, W E; Howell, S B

    1984-11-15

    cis-Diamminedichloroplatinum(II) (DDP) was measured in plasma ultrafiltrate following derivatization with sodium diethyldithiocarbamate (DDTC) by quantitation against a nickel chloride internal standard. A chloroform extract containing the Pt(DDTC)2 and Ni(DDTC)2 complexes was separated by reversed-phase high-performance liquid chromatography on a C18 radial compression column. The complex was eluted with methanol/water, 4/1, at a flow rate of 1.5 ml/min, and was detected at 254 nm. The limit of sensitivity was 0.1 microgram/ml DDP in the ultrafiltrate. This analytical approach was validated by comparison to graphite furnace atomic absorption spectrophotometric determinations of duplicate samples. There was clearly a component of the ultrafiltrable platinum present that was resistant to derivatization by DDTC. Evidence is presented that this component, presumably Pt(II) complexed with endogenous small molecules, is non cytotoxic and, hence, that this method may be selective for "active Pt(II)." This method offers an advantage over atomic absorption determination of total platinum in ultrafiltrate which does not discriminate between active and inactive forms, and over off-line FAA detection of parent DDP in HPLC eluates which ignores other active forms. Using this technique we have measured the pharmacokinetics of DDTC-reactive Pt(II) in humans after either i.v. infusion or infusion of DDP into the peritoneal cavity of patients with ovarian carcinoma. PMID:6099065

  16. REMOVAL OF MICROBIAL CONTAMINANTS IN DRINKING WATER: KOCH MEMBRANE SYSTEMS, HF-82-35-PMPW™ ULTRAFILTRATION MEMBRANE

    EPA Science Inventory

    Two Koch Membrane Systems HF-82-35-PMPW ultrafiltration membrane cartridges were tested for removal of viruses, bacteria, and protozoan cysts at NSF’s Drinking Water Treatment Systems Laboratory. The ETV testing was conducted as part of a series of evaluations of the Expeditiona...

  17. Ceramic membrane fouling during ultrafiltration of oil/water emulsions: roles played by stabilization surfactants of oil droplets.

    PubMed

    Lu, Dongwei; Zhang, Tao; Ma, Jun

    2015-04-01

    Oil/water (O/W) emulsion stabilized by surfactants is the part of oily wastewater that is most difficult to handle. Ceramic membrane ultrafiltration presently is an ideal process to treat O/W emulsions. However, little is known about the fouling mechanism of the ceramic membrane during O/W emulsion treatment. This paper investigated how stabilization surfactants of O/W emulsions influence the irreversible fouling of ceramic membranes during ultrafiltration. An unexpected phenomenon observed was that irreversible fouling was much less when the charge of the stabilization surfactant of O/W emulsions is opposite to the membrane. The less ceramic membrane fouling in this case was proposed to be due to a synergetic steric effect and demulsification effect which prevented the penetration of oil droplets into membrane pores and led to less pore blockage. This proposed mechanism was supported by cross section images of fouled and virgin ceramic membranes taken with scanning electron microscopy, regression results of classical fouling models, and analysis of organic components rejected by the membrane. Furthermore, this mechanism was also verified by the existence of a steric effect and demulsification effect. Our finding suggests that ceramic membrane oppositely charged to the stabilization surfactant should be applied in ultrafiltration of O/W emulsions to alleviate irreversible membrane fouling. It could be a useful rule for ceramic membrane ultrafiltration of oily wastewater.

  18. Evaluation of Hollow-Fiber Ultrafiltration Primary Concentration of Pathogens and Secondary Concentration of Viruses from Water

    EPA Science Inventory

    In this study, tangential hollow-fiber ultrafiltration (HFUF) was evaluated for virus and Cryptosporidium parvum concentration. Recovery of viruses at a low filtration rate was found to be significantly greater than at a higher filtration rate, with the recoveries of bacteriopha...

  19. Ultrafiltration of highly concentrated antibody solutions: Experiments and modeling for the effects of module and buffer conditions.

    PubMed

    Binabaji, Elaheh; Ma, Junfen; Rao, Suma; Zydney, Andrew L

    2016-05-01

    Although ultrafiltration is currently used for the concentration and formulation of nearly all biotherapeutics, obtaining the very high target concentrations for monoclonal antibody products is challenging. The objective of this work was to examine the effects of the membrane module design and buffer conditions on both the filtrate flux and maximum achievable protein concentration during the ultrafiltration of highly concentrated monoclonal antibody solutions. Experimental data were obtained using both hollow fiber and screened cassettes and in the presence of specific excipients that are known to alter the solution viscosity. Data were compared with predictions of a recently developed model that accounts for the complex thermodynamic and hydrodynamic behavior in these systems, including the effects of back-filtration arising from the large pressure drop through the module due to the high viscosity of the concentrated antibody solutions. Model calculations were in good agreement with experimental data in hollow fiber modules with very different fiber length and in screened cassettes having different screen geometries. These results provide important insights into the key factors controlling the filtrate flux and maximum achievable protein concentration during ultrafiltration of highly concentrated antibody solutions as well as a framework for the development of enhanced ultrafiltration processes for this application. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:692-701, 2016.

  20. Novel cellobiose 2-epimerases for the production of epilactose from milk ultrafiltrate containing lactose.

    PubMed

    Krewinkel, Manuel; Kaiser, Jana; Merz, Michael; Rentschler, Eva; Kuschel, Beatrice; Hinrichs, Jörg; Fischer, Lutz

    2015-06-01

    A selected number of enzymes have recently been assigned to the emerging class of cellobiose 2-epimerases (CE). All CE convert lactose to the rare sugar epilactose, which is regarded as a new prebiotic. Within this study, the gene products of 2 potential CE genes originating from the mesophilic bacteria Cellulosilyticum lentocellum and Dysgonomonas gadei were recombinantly produced in Escherichia coli and purified by chromatography. The enzymes have been identified as novel CE by sequence analysis and biochemical characterizations. The biochemical characterizations included the determination of the molecular weight, the substrate spectrum, and the kinetic parameters, as well as the pH and temperature profiles in buffer and food matrices. Both identified CE epimerize cellobiose and lactose into the C2 epimerization products glucosylmannose and epilactose, respectively. The epimerization activity for lactose was maximal at pH 8.0 or 7.5 and 40°C in defined buffer systems for the CE from C. lentocellum and the CE from D. gadei, respectively. In addition, biotransformations of the foodstuff milk ultrafiltrate containing lactose were demonstrated. The CE from D. gadei was produced in a stirred-tank reactor (12 L) and purified using an automatic system. Enzyme production and purification in this scale indicates that a future upscaling of CE production is possible. The bioconversions of lactose in milk ultrafiltrate were carried out either in a batch process or in a continuously operated enzyme membrane reactor (EMR) process. Both processes ran at an industrially relevant low temperature of 8°C to reduce undesirable microbial growth. The enzyme was reasonably active at the low process temperature because the CE originated from a mesophilic organism. An epilactose yield of 29.9% was achieved in the batch process within 28 h of operation time. In the continuous EMR process, the epilactose yield in the product stream was lower, at 18.5%. However, the enzyme productivity

  1. Physicochemical and Microbiological Properties of Yogurt-cheese Manufactured with Ultrafiltrated Cow's Milk and Soy Milk Blends.

    PubMed

    Lee, Na-Kyoung; Mok, Bo Ram; Jeewanthi, Renda Kankanamge Chaturika; Yoon, Yoh Chang; Paik, Hyun-Dong

    2015-01-01

    The objective of this study was to develop yogurt-cheese using cow's milk, ultrafiltrated cow's milk, and soy milk. The addition of soy milk and ultrafiltrated milk increased the amount of protein in the yogurt-cheese. Yogurt-cheeses were made using cheese base using 10% and 20% soy milk with raw and ultrafiltrated cow's milk, and stored at 4℃ during 2 wk. The yield of yogurt-cheeses made with added soy milk was decreased and the cutting point was delayed compared to yogurt-cheese made without soy milk. Yogurt-cheese made using ultrafiltrated cow's milk showed the highest yield. However, yogurt-cheese made with added soy milk had higher protein content and titratable acidity than yogurt-cheese made using raw and ultrafiltrated cow's milk. Fat and lactose contents in the yogurt-cheese made with added soy milk were lower. Yogurt-cheeses made with added soy milk contained several soy protein bands corresponding to the sizes of α2-, β-, and κ-casein band. Yogurt-cheese made with added soy milk had similar elasticity to yogurt-cheese made without soy milk but had lower cohesiveness. There was no significant difference in the number of lactic acid bacteria in the different cheeses, as all had over 8.0 Log CFU/g. Considering these data and the fact that proteins and fats of vegetable origin with high biological value were observed as well as unsaturated fats, yogurt-cheese made with added soy milk can be considered to be a functional food.

  2. Physicochemical and Microbiological Properties of Yogurt-cheese Manufactured with Ultrafiltrated Cow's Milk and Soy Milk Blends

    PubMed Central

    Lee, Na-Kyoung; Mok, Bo Ram; Jeewanthi, Renda Kankanamge Chaturika; Yoon, Yoh Chang; Paik, Hyun-Dong

    2015-01-01

    The objective of this study was to develop yogurt-cheese using cow’s milk, ultrafiltrated cow’s milk, and soy milk. The addition of soy milk and ultrafiltrated milk increased the amount of protein in the yogurt-cheese. Yogurt-cheeses were made using cheese base using 10% and 20% soy milk with raw and ultrafiltrated cow’s milk, and stored at 4℃ during 2 wk. The yield of yogurt-cheeses made with added soy milk was decreased and the cutting point was delayed compared to yogurt-cheese made without soy milk. Yogurt-cheese made using ultrafiltrated cow’s milk showed the highest yield. However, yogurt-cheese made with added soy milk had higher protein content and titratable acidity than yogurt-cheese made using raw and ultrafiltrated cow’s milk. Fat and lactose contents in the yogurt-cheese made with added soy milk were lower. Yogurt-cheeses made with added soy milk contained several soy protein bands corresponding to the sizes of α2-, β-, and κ-casein band. Yogurt-cheese made with added soy milk had similar elasticity to yogurt-cheese made without soy milk but had lower cohesiveness. There was no significant difference in the number of lactic acid bacteria in the different cheeses, as all had over 8.0 Log CFU/g. Considering these data and the fact that proteins and fats of vegetable origin with high biological value were observed as well as unsaturated fats, yogurt-cheese made with added soy milk can be considered to be a functional food. PMID:26761829

  3. Bisphenol A removal by combination of powdered activated carbon adsorption and ultrafiltration

    NASA Astrophysics Data System (ADS)

    Wang, Rongchang; Tong, Hao; Xia, Siqing; Zhang, Yalei; Zhao, Jianfu

    2010-11-01

    Bisphenol A (BPA) removal from surface water in the presence of natural organic matter (NOM) by combination of powdered activated carbon (PAC) adsorption and ultrafiltration (UF) was investigated in this study. It was especially focused on the effects of various factors on BPA removal, such as PAC dosage, NOM concentration and pH value. BPA removal by UF+PAC process increased sharply from 4% to 92%, when PAC dosage increased from 0 to 120 mg/L. The optimal PAC dosage was determined to be 30 mg/L. The results also showed that BPA retention was slightly favored in the presence of NOM. As pH increased from 7.0 to 10.5, BPA removal substantially decreased from 90% to 59%. PAC+UF process is recommended to be used as an emergence facility in drinking water treatment, especially when an accidental spilling of deleterious substance, e.g., BPA, in the water resources happens.

  4. Effects of protein concentration and detergent on endotoxin reduction by ultrafiltration.

    PubMed

    Jang, Hyun; Kim, Hyo-Seung; Moon, Seung-Cheol; Lee, Young-Rae; Yu, Kang-Yeoul; Lee, Byeong-Kil; Youn, Hyun Zo; Jeong, Young-Ju; Kim, Byeong-Soo; Lee, Sung-Ho; Kim, Jong-Suk

    2009-07-31

    Lipopolysaccharide (LPS), found in the outer membrane of Gram negative bacteria, only exerts its toxic effects when in free form. LPS has three major parts, lipid A, the toxic component, along with a core polysaccharide and O-specific polysaccharide. LPS monomers are known to have molecular masses between 10 to 30 kDa. Under physiological conditions, LPS exists in equilibrium between monomer and vesicle forms. LPS removal by 100 kDa ultrafiltration was more efficient (99.6% of LPS removed) with a low concentration of protein (2.0 mg/ml) compared to a high concentration (20.1 mg/ml). In the presence of different detergents (0.5% Tween 20, 1.0% taurodeoxycholate and 1.0% Triton X-100), LPS removal was more efficient at low protein concentrations (2.0 mg/ml) compared to high protein concentrations (20.1 mg/ml).

  5. New conductive copolymer membranes via track-etched PC templates for biological media ultra-filtration

    NASA Astrophysics Data System (ADS)

    Berthelot, T.; Baudin, C.; Balanzat, E.; Clochard, M.-C.

    2007-12-01

    New microstructurated copolymer membranes have been synthesized using a track-etched polycarbonate (PC) matrix. These membranes proved to be an important device in the field of ultra-filtration and synthetic membranes. These novel structures were obtained by irradiating at various angles (+30°, -30°). Such architecture is expected to improve not only the exchange properties but also, the behaviour under high flow pressure during their use as nanofiltration membranes. Membrane functionalization was performed with an amino acid as a simple biological model. Transmission and ATR-FTIR spectroscopies show that the doping state of copolymer dramatically influences the amino acid coupling rate. UV-vis spectroscopy indicates that the copolymer may be self-doped.

  6. Optimized Porous Anodic Alumina Membranes for Water Ultrafiltration of Pathogenic Bacteria (E. coli).

    PubMed

    Zimer, Alexsandro Mendes; Machado, Maria Manuela P; Dalla Costa Júnior, Lázaro José; Ike, Priscila Tomie Leme; Iemma Mônica R C; Yamamoto, Cíntia Fumi; Ferreira, Cauê Favero; Souza, Dulce H F; de Oliveira, Cauê Ribeiro; Pereira, Ernesto Chaves

    2016-06-01

    In this paper, we present the optimization of porous anodic alumina membranes for ultrafiltration prepared by anodically oxidized aluminum foils. The membranes were characterized by field-emission scanning electron microscopy to measure the pore diameter and the membrane thicknesses. The liquid fluxes were estimated through gas permeability measurements using Darcy's and Forchheimerś equations. A 2(3) factorial design we used to optimize the membrane properties: pore diameter, membrane thickness, and liquid flux using as control variables the applied current density, solution composition and concentration. It was observed that the most import variables to control the pore diameter were current density and electrolyte composition. After the anodization both, metallic aluminum substrate and the barrier layer of alumina were removed using adequate solutions to obtain the free standing membrane. Then, Escherichia coli a common bacterial contamination of drinking water was removed using these PAA membranes with 100% of efficiency to obtain bacteria-free water. PMID:27427747

  7. Syneresis rate of cow's, ewe's, and goat's curd. Effect of thermal treatment and ultrafiltration.

    PubMed

    Calvo, M M; Espinoza, N A

    1999-03-01

    The influences of ultrafiltration (UF), the intensity of heat treatment (70 degrees C for 5 or 30 min) applied to milk prior to UF processing, and species on the syneresis rate of curd from cow's, ewe's, and goat's milk were analyzed. The influence of the species was significant (P < 0.05) in the syneresis rate. The syneresis rate depended significantly on the intensity of the heat treatment applied before UF and the degree of concentration; these two parameters showed significant (P < 0.05) differences in the syneresis rate depending on the species studied. These results could indicate a possible difference in the structure of the curd formed. The differences in the curd structure could be due to the different relative composition of the retentates of the different species as well as the possible effect of the UF process on the physicochemical composition of milk.

  8. Cheese whey protein recovery by ultrafiltration through transglutaminase (TG) catalysis whey protein cross-linking.

    PubMed

    Wen-Qiong, Wang; Lan-Wei, Zhang; Xue, Han; Yi, Lu

    2017-01-15

    In whey ultrafiltration (UF) production, two main problems are whey protein recovery and membrane fouling. In this study, membrane coupling protein transglutaminase (TG) catalysis protein cross-linking was investigated under different conditions to find out the best treatment. We found that the optimal conditions for protein recovery involved catalyzing whey protein cross-linking with TG (40U/g whey proteins) at 40°C for 60min at pH 5.0. Under these conditions, the recovery rate was increased 15-20%, lactose rejection rate was decreased by 10%, and relative permeate flux was increase 30-40% compared to the sample without enzyme treatment (control). It was noticeable that the total resistance and cake resistance were decreased after enzyme catalysis. This was mainly due to the increased particle size and decreased zeta potential. Therefore, membrane coupling enzyme catalysis protein cross-linking is a potential means for further use.

  9. Ultrafiltration by a compacted clay membrane-I. Oxygen and hydrogen isotopic fractionation

    USGS Publications Warehouse

    Coplen, T.B.; Hanshaw, B.B.

    1973-01-01

    Laboratory experiments were carried out to determine the magnitude of the isotopic fractionation of distilled water and of 0.01 N NaCl forced to flow at ambient temperature under a hydraulic pressure drop of 100 bars across a montmorillonite disc compacted to a porosity of 35 per cent by a pressure of 330 bars. The ultrafiltrates in both experiments were depleted in D by 2.5%. and in O18 by 0.8%. relative to the residual solution. No additional isotopic fractionation due to a salt filtering mechanism was observed at NaCl concentrations up to 0.01 N. Adsorption is most likely the principal mechanism which produces isotopic fractionation, but molecular diffusion may play a minor role. The results suggest that oxygen and hydrogen isotopic fractionation of ground water during passage through compacted clayey sediments should be a common occurrence, in accord with published interpretations of isotopic data from the Illinois and Alberta basins. ?? 1973.

  10. Optimized Porous Anodic Alumina Membranes for Water Ultrafiltration of Pathogenic Bacteria (E. coli).

    PubMed

    Zimer, Alexsandro Mendes; Machado, Maria Manuela P; Dalla Costa Júnior, Lázaro José; Ike, Priscila Tomie Leme; Iemma Mônica R C; Yamamoto, Cíntia Fumi; Ferreira, Cauê Favero; Souza, Dulce H F; de Oliveira, Cauê Ribeiro; Pereira, Ernesto Chaves

    2016-06-01

    In this paper, we present the optimization of porous anodic alumina membranes for ultrafiltration prepared by anodically oxidized aluminum foils. The membranes were characterized by field-emission scanning electron microscopy to measure the pore diameter and the membrane thicknesses. The liquid fluxes were estimated through gas permeability measurements using Darcy's and Forchheimerś equations. A 2(3) factorial design we used to optimize the membrane properties: pore diameter, membrane thickness, and liquid flux using as control variables the applied current density, solution composition and concentration. It was observed that the most import variables to control the pore diameter were current density and electrolyte composition. After the anodization both, metallic aluminum substrate and the barrier layer of alumina were removed using adequate solutions to obtain the free standing membrane. Then, Escherichia coli a common bacterial contamination of drinking water was removed using these PAA membranes with 100% of efficiency to obtain bacteria-free water.

  11. Treatment of laundry wastes by the combination of ultrafiltration and reverse osmosis

    SciTech Connect

    Lee, K.W.; Park, S.C.; Park, H.H.; Kim, J.H.

    1993-12-31

    Fundamental and pilot-scale experiments were conducted to develop a laundry waste treatment system for a nuclear research center. The system is composed of a preconcentration step with reverse osmosis (RO) unit, a volume reduction step with ultrafiltration (UF) unit, and the final purification step with RO unit. At the RO process, the waste was concentrated over the critical micelle concentration on the basis of surfactant concentration. The performance of the UF process was investigated by adsorption experiments of radionuclides on the micellar surface and the separation of the micelles. Under the experimental conditions studied, the overall volume reduction factor over the entire processes was 250 and the average decontamination factors of C{sup 60} and Cs{sup 137} were 110 and 20 respectively.

  12. Processing used nuclear fuel with nanoscale control of uranium and ultrafiltration

    NASA Astrophysics Data System (ADS)

    Wylie, Ernest M.; Peruski, Kathryn M.; Prizio, Sarah E.; Bridges, Andrea N. A.; Rudisill, Tracy S.; Hobbs, David T.; Phillip, William A.; Burns, Peter C.

    2016-05-01

    Current separation and purification technologies utilized in the nuclear fuel cycle rely primarily on liquid-liquid extraction and ion-exchange processes. Here, we report a laboratory-scale aqueous process that demonstrates nanoscale control for the recovery of uranium from simulated used nuclear fuel (SIMFUEL). The selective, hydrogen peroxide induced oxidative dissolution of SIMFUEL material results in the rapid assembly of persistent uranyl peroxide nanocluster species that can be separated and recovered at moderate to high yield from other process-soluble constituents using sequestration-assisted ultrafiltration. Implementation of size-selective physical processes like filtration could results in an overall simplification of nuclear fuel cycle technology, improving the environmental consequences of nuclear energy and reducing costs of processing.

  13. Improved Therapeutic Profiles of PLA2-Free Bee Venom Prepared by Ultrafiltration Method

    PubMed Central

    Lee, Hyunkyoung; Pyo, Min-Jung; Bae, Seong Kyeong; Heo, Yunwi; Kim, Choul Goo; Kang, Changkeun

    2015-01-01

    Bee venom (BV) has long been used in traditional Eastern and Western medicine for chronic inflammation, pain and skin therapy. Human exposure to BV, however, often causes unwanted adverse effects and is even fatal in some cases. Phospholipase A2 (PLA2) of BV is now suspected to play a key role in these adverse effects. We investigated the potential use of PLA2-free bee venom (PBV) as a replacement for BV in cosmetic products. PBV prepared by molecular weight cut-off ultrafiltration exhibits a superior profile in comparison with regular BV, by inhibiting elastase activity and suppressing the induction of nitric oxide (NO) and metalloproteinase-9 (MMP-9), while retaining the effects of cell proliferation and protection against ultraviolet B (UVB)-induced damage in human dermal fibroblast cells. PBV thus appears to be more promising than BV as a cosmetic ingredient with a reduced potential for adverse reactions in the recipient. PMID:25874031

  14. Modeling the improvement of ultrafiltration membrane mass transfer when using biofiltration pretreatment in surface water applications.

    PubMed

    Netcher, Andrea C; Duranceau, Steven J

    2016-03-01

    In surface water treatment, ultrafiltration (UF) membranes are widely used because of their ability to supply safe drinking water. Although UF membranes produce high-quality water, their efficiency is limited by fouling. Improving UF filtrate productivity is economically desirable and has been attempted by incorporating sustainable biofiltration processes as pretreatment to UF with varying success. The availability of models that can be applied to describe the effectiveness of biofiltration on membrane mass transfer are lacking. In this work, UF water productivity was empirically modeled as a function of biofilter feed water quality using either a quadratic or Gaussian relationship. UF membrane mass transfer variability was found to be governed by the dimensionless mass ratio between the alkalinity (ALK) and dissolved organic carbon (DOC). UF membrane productivity was optimized when the biofilter feed water ALK to DOC ratio fell between 10 and 14.

  15. Cheese whey protein recovery by ultrafiltration through transglutaminase (TG) catalysis whey protein cross-linking.

    PubMed

    Wen-Qiong, Wang; Lan-Wei, Zhang; Xue, Han; Yi, Lu

    2017-01-15

    In whey ultrafiltration (UF) production, two main problems are whey protein recovery and membrane fouling. In this study, membrane coupling protein transglutaminase (TG) catalysis protein cross-linking was investigated under different conditions to find out the best treatment. We found that the optimal conditions for protein recovery involved catalyzing whey protein cross-linking with TG (40U/g whey proteins) at 40°C for 60min at pH 5.0. Under these conditions, the recovery rate was increased 15-20%, lactose rejection rate was decreased by 10%, and relative permeate flux was increase 30-40% compared to the sample without enzyme treatment (control). It was noticeable that the total resistance and cake resistance were decreased after enzyme catalysis. This was mainly due to the increased particle size and decreased zeta potential. Therefore, membrane coupling enzyme catalysis protein cross-linking is a potential means for further use. PMID:27542447

  16. Ultrafiltration Failure and Impaired Sodium Sieving During Long-Term Peritoneal Dialysis: More Than Aquaporin Dysfunction?

    PubMed

    Morelle, Johann; Sow, Amadou; Hautem, Nicolas; Devuyst, Olivier; Goffin, Eric

    2016-01-01

    Fifteen years ago, our group reported the case of a 67-year-old man on peritoneal dialysis for 11 years, in whom ultrafiltration failure and impaired sodium sieving were associated with an apparently normal expression of aquaporin-1 (AQP1) water channels in peritoneal capillaries. At that time, AQP1 dysfunction was suggested as the cause of impaired free-water transport. However, recent data from computer simulations, and structural and functional analysis of the peritoneal membrane of patients with encapsulating peritoneal sclerosis, demonstrated that changes in the peritoneal interstitium directly alter osmotic water transport. In light of these insights, we challenge the initial hypothesis and provide several lines of evidence supporting the diagnosis of encapsulating peritoneal sclerosis in this patient and suggesting that severe peritoneal fibrosis accounted for the loss of osmotic conductance developed during the course of peritoneal dialysis. PMID:27006441

  17. Method for concentration and separation of biological organisms by ultrafiltration and dielectrophoresis

    SciTech Connect

    Simmons, Blake A.; Hill, Vincent R.; Fintschenko, Yolanda; Cummings, Eric B.

    2012-09-04

    Disclosed is a method for monitoring sources of public water supply for a variety of pathogens by using a combination of ultrafiltration techniques together dielectrophoretic separation techniques. Because water-borne pathogens, whether present due to "natural" contamination or intentional introduction, would likely be present in drinking water at low concentrations when samples are collected for monitoring or outbreak investigations, an approach is needed to quickly and efficiently concentrate and separate particles such as viruses, bacteria, and parasites in large volumes of water (e.g., 100 L or more) while simultaneously reducing the sample volume to levels sufficient for detecting low concentrations of microbes (e.g., <10 mL). The technique is also designed to screen the separated microbes based on specific conductivity and size.

  18. Integrated coagulation-trickling filter-ultrafiltration processes for domestic wastewater treatment and reclamation.

    PubMed

    Zhao, Qing-Liang; Zhong, Hui-Yuan; Liu, Jin-Li; Liu, Yu

    2012-01-01

    More and more research effort has been put into the development of affordable and high-efficiency wastewater reclamation technology for small communities. In this study, an integrated chemically enhanced primary treatment (CEPT), trickling filter (TF) and ultrafiltration (UF) process was developed with success. Coagulant produced from fly ash was used to enhance primary treatment, while trickling filter packed with coal cinder through four-layer structure without aeration was employed for further removal of COD and ammonium-nitrogen from the CEPT effluent. 95 and 88% removal of COD and ammonium were achieved, while total phosphorus (TP) and suspended solid (SS) were found to be removed completely at a coagulant dosage of 2.5 mL/L in the CEPT-TF-UF system. The product water can meet the standard of Reuse of Recycling Water for Urban Water Quality Standard for Urban Miscellaneous Water Consumption (GB/T 18920-2002, China).

  19. Effects of Conventional Ultrafiltration on Renal Performance During Adult Cardiopulmonary Bypass Procedures

    PubMed Central

    Kuntz, Rick A.; Holt, David W.; Turner, Scott; Stichka, Lee; Thacker, Bryan

    2006-01-01

    Abstract: Ultrafiltration has been used successfully in a variety of applications in the perioperative setting to assist in hemoconcentration and volume reduction. This study was designed to investigate the effects of aggressive conventional hemofiltration on bypass urine production, fluid balance, and renal performance in the 24 hours after bypass procedures in the adult population. A prospective, randomized study was designed to determine the effects of conventional ultrafiltration (CUF) during bypass while monitoring urine dynamics intraoperatively and in the 24-hour post-bypass period. Study group 1 (CUF, n = 49) was compared to control group 2 (non-CUF, n _ 47) by monitoring urine values, volume additions, and packed red cell (PRC) use throughout the procedure. The mean total CUF volume removed from group 1 was 5781 ± 2612. There were no differences in prebypass, total bypass, or total operating room (OR) urine between the two groups. The 24-hour urine totals were significantly higher in group 2 (2389 ± 895) than in group 1 (2035 ± 895). The ending bypass hematocrit was also lower in group 2 (26 ± 2.0) than in group 1 (30 ± 6.0). OR PRC additions were higher in group 2 (395 ± 699) than group 1 (204 ± 300). The non-CUF control group 2 experienced significantly greater ending fluid balance (3006 ± 868) compared with group 1 (744 ± 1271). No significant differences in pre- or postoperative creatinine values were observed. Aggressive CUF can be safely used during cardiopulmonary bypass in the adult population to reduce fluid accumulation and elevate bypass hematocrit without effecting bypass or intraoperative urine production. PMID:16921688

  20. Tangential flow ultrafiltration for detection of white spot syndrome virus (WSSV) in shrimp pond water.

    PubMed

    Alavandi, S V; Ananda Bharathi, R; Satheesh Kumar, S; Dineshkumar, N; Saravanakumar, C; Joseph Sahaya Rajan, J

    2015-06-15

    Water represents the most important component in the white spot syndrome virus (WSSV) transmission pathway in aquaculture, yet there is very little information. Detection of viruses in water is a challenge, since their counts will often be too low to be detected by available methods such as polymerase chain reaction (PCR). In order to overcome this difficulty, viruses in water have to be concentrated from large volumes of water prior to detection. In this study, a total of 19 water samples from aquaculture ecosystem comprising 3 creeks, 10 shrimp culture ponds, 3 shrimp broodstock tanks and 2 larval rearing tanks of shrimp hatcheries and a sample from a hatchery effluent treatment tank were subjected to concentration of viruses by ultrafiltration (UF) using tangential flow filtration (TFF). Twenty to 100l of water from these sources was concentrated to a final volume of 100mL (200-1000 fold). The efficiency of recovery of WSSV by TFF ranged from 7.5 to 89.61%. WSSV could be successfully detected by PCR in the viral concentrates obtained from water samples of three shrimp culture ponds, one each of the shrimp broodstock tank, larval rearing tank, and the shrimp hatchery effluent treatment tank with WSSV copy numbers ranging from 6 to 157mL(-1) by quantitative real time PCR. The ultrafiltration virus concentration technique enables efficient detection of shrimp viral pathogens in water from aquaculture facilities. It could be used as an important tool to understand the efficacy of biosecurity protocols adopted in the aquaculture facility and to carry out epidemiological investigations of aquatic viral pathogens.

  1. Enhancing effect of serum ultrafiltrate on the activity of cephalosporins against gram-negative bacilli.

    PubMed Central

    Leggett, J E; Craig, W A

    1989-01-01

    A few studies have suggested that the inhibitory effect of serum on activity of broad-spectrum cephalosporins is less than that predicted by the degree of protein binding. Microdilution MICs of ceftriaxone, cefoperazone, moxalactam, and ceftizoxime were therefore determined against ATCC and clinical strains of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus in Mueller-Hinton broth containing either human albumin (as 0, 2.5, or 5% solution) or heat-inactivated human serum (as 0, 25, 50, or 95% solution). Arithmetic linear dilutions were used to improve accuracy. For standard bacterial strains, MICs in the presence of 5% albumin were higher than in broth alone by multiples of 10.9 to 21 for ceftriaxone, 5.5 to 16.4 for cefoperazone, 1.9 to 3.7 for moxalactam, and 1.1 to 1.4 for ceftizoxime, as expected by their protein binding. MICs in the presence of 95% serum were similar to those in 5% albumin for all four drugs against S. aureus and P. aeruginosa but were 2.2- to 4.8-fold lower (P less than 0.001) against E. coli and K. pneumoniae. Similar findings were observed at lower protein concentrations and with clinical isolates, except that for some strains of P. aeruginosa MICs were lower in serum than in albumin. Individual sera from five subjects gave comparable results. The addition of serum ultrafiltrate to albumin-containing solutions reduced MICs of ceftriaxone and cefoperazone 1.6- to 7.4-fold against E. coli and K. pneumoniae (P less than 0.01) but did not alter the MICs for S. aureus. Serum may contain an ultrafiltrable component(s) that enhances the activity of third-generation cephalosporins against many gram-negative bacilli. PMID:2496656

  2. Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor.

    PubMed

    Holloway, Ryan W; Regnery, Julia; Nghiem, Long D; Cath, Tzahi Y

    2014-09-16

    A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications. PMID:25113310

  3. B-type natriuretic peptide-directed ultrafiltration improves care in acutely hospitalized dialysis patients.

    PubMed

    Tapolyai, Mihály; Uysal, Aşkin; Maeweathers, Gail; Bahta, Elias; Dossabhoy, Neville R

    2009-01-01

    In an observational study in 19 consecutive acutely hospitalized dialysis patients, ultrafiltration (UF) volume was determined by B-type natriuretic peptide (BNP) levels. Patients were ultrafiltrated daily until they achieved a target BNP level <500 pg/mL. The UF volumes ranged from 2 to 5 L per session. All patients were male veterans aged 68+/-11 years (mean +/- SD), 74% were diabetic, 47% were African Americans, 58% underwent prevalent dialysis, and 53% had an arteriovenous fistula. Left ventricular ejection fraction on 2-dimensional echocardiography was 43.8%+/-27.9% (n=16). The admission BNP was 2412+/-1479 pg/mL (range, 561-5000 pg/mL) and BNP at hospital discharge was 1245+/-1173 pg/mL (range, 345-5000 pg/mL) (nonparametric Wilcoxon P=.0013). Admission weight was 88.9+/-27.9 kg and at discharge was 78.1+/-25.6 kg (P=.0002). The number of antihypertensive medications taken was 3.8+/-2.0 at admission and 2.3+/-1.7 at discharge (P=.0005). The number of patients with >2 blood pressure medications decreased from 14 to 6 (Fisher exact test, P=.02). The systolic/diastolic/mean arterial blood pressure decreased from admission to discharge (153.6+/-43.8/80.6+/-21.8/102.4+/-27.3 to 132.1+/-27.9/68.9+/-14.6/89.9+/-16.5 mm Hg; P=.0222/.0139/.0329, respectively). Although all patients were volume-overloaded at admission according to BNP criteria (>500), only 42% were identified as having heart failure. BNP-directed UF is safe because it minimizes symptomatic hypotension, identifies occult congestive heart failure in a large number of patients, and significantly reduces blood pressure in addition to reducing body weight and number of medications used. PMID:19522962

  4. Removal of trace organic chemicals and performance of a novel hybrid ultrafiltration-osmotic membrane bioreactor.

    PubMed

    Holloway, Ryan W; Regnery, Julia; Nghiem, Long D; Cath, Tzahi Y

    2014-09-16

    A hybrid ultrafiltration-osmotic membrane bioreactor (UFO-MBR) was investigated for over 35 days for nutrient and trace organic chemical (TOrC) removal from municipal wastewater. The UFO-MBR system uses both ultrafiltration (UF) and forward osmosis (FO) membranes in parallel to simultaneously extract clean water from an activated sludge reactor for nonpotable (or environmental discharge) and potable reuse, respectively. In the FO stream, water is drawn by osmosis from activated sludge through an FO membrane into a draw solution (DS), which becomes diluted during the process. A reverse osmosis (RO) system is then used to reconcentrate the diluted DS and produce clean water suitable for direct potable reuse. The UF membrane extracts water, dissolved salts, and some nutrients from the system to prevent their accumulation in the activated sludge of the osmotic MBR. The UF permeate can be used for nonpotable reuse purposes (e.g., irrigation and toilet flushing). Results from UFO-MBR investigation illustrated that the chemical oxygen demand, total nitrogen, and total phosphorus removals were greater than 99%, 82%, and 99%, respectively. Twenty TOrCs were detected in the municipal wastewater that was used as feed to the UFO-MBR system. Among these 20 TOrCs, 15 were removed by the hybrid UFO-MBR system to below the detection limit. High FO membrane rejection was observed for all ionic and nonionic hydrophilic TOrCs and lower rejection was observed for nonionic hydrophobic TOrCs. With the exceptions of bisphenol A and DEET, all TOrCs that were detected in the DS were well rejected by the RO membrane. Overall, the UFO-MBR can operate sustainably and has the potential to be utilized for direct potable reuse applications.

  5. On-line micellar-enhanced spectrofluorimetric determination of rhodamine dye in cosmetics.

    PubMed

    Wang, Chien Chun; Masi, Adriana N; Fernández, Liliana

    2008-03-15

    A simple FI-fluorimetric analytical methodology for the continuous and sequential determination of rhodamine B (RhB) in cosmetic products has been developed and evaluated in terms of sensibility and selectivity. The influence of several surfactant solutions on RhB fluorescence signal has been studied; particular attention was paid in the aggregation behavior of RhB-SDS system. Linear response has been obtained in the range of 1.6 x 10(-9) and 1 x 10(-6) mol L(-1), with a detection limit of 5 x 10(-10) mol L(-1). The novel technique provides a simple dissolution of sample, on-line filtration with sampling rate higher than 100 samples h(-1) and has been satisfactorily applied to the RhB determination in commercial lipsticks.

  6. A Modified EPA Method 1623 that Uses Tangential Flow Hollow-Fiber Ultrafiltration and Heat Dissociation Steps to Detect Waterborne Cryptosporidum and Giardia spp.

    EPA Science Inventory

    This protocol describes the use of a tangential flow hollow-fiber ultrafiltration sample concentration system and a heat dissociation as alternative steps for the detection of waterborne Cryptosporidium and Giardia species using EPA Method 1623.

  7. Ultrafiltration, a useful method for isolation of intermediates in native chemical ligation exemplified with the total synthesis of Sortase AΔN59.

    PubMed

    Deng, Fang-kun

    2015-04-01

    In this paper, ultrafiltration was employed to facilitate the isolation of intermediates in native chemical ligation. Depending on the molecular weight cutoff of the membrane used, molecules with different sizes could be purified, separated, or concentrated by the ultrafiltration process. Total chemical synthesis of the polypeptide chain of the enzyme Sortase AΔN59 was used as an example of the application of ultrafiltration in chemical protein synthesis. Sortase A is a ligase that catalyzes transpeptidation reactions between proteins that have C-terminal LPXTG recognition sequence and Gly5- on the peptidoglycan of bacterial cell walls. Ultrafiltration technique facilitated synthesis of Sortase AΔN59 and was a promising tool in isolation of intermediates in native chemical ligation.

  8. Novel Use of an Ultrafiltration Device as an Alternative Method for Fluid Removal in Critically Ill Pediatric Patients with Cardiac Disease: A Case Series

    PubMed Central

    Chakravarti, Sujata; Al-Qaqaa, Yasir; Faulkner, Meghan; Bhatla, Puneet; Argilla, Michael; Ramirez, Michelle

    2016-01-01

    Fluid overload (FO) is a common complication for pediatric patients in the intensive care unit. When conventional therapy fails, hemodialysis or peritoneal dialysis is classically used for fluid removal. Unfortunately, these therapies are often associated with cardiovascular or respiratory instability. Ultrafiltration, using devices such as the Aquadex™ system (Baxter Healthcare, Deerfield, IL, USA), is an effective tool for fluid removal in adult patients with congestive heart failure. As compared to hemodialysis, ultrafiltration can be performed using smaller catheters, and the extracorporeal volume and minimal blood flow rates are lower. In addition, there is no associated abdominal distension as is seen in peritoneal dialysis. Consequently, ultrafiltration may be better tolerated in critically ill pediatric patients. We present three cases of challenging pediatric patients with FO in the setting of congenital heart disease in whom ultrafiltration using the Aquadex™ system was successfully utilized for fluid removal while cardiorespiratory stability was maintained. PMID:27433308

  9. Photochemical modification of poly(ether sulfone) ultrafiltration membranes by UV-assisted graft polymerization for the prevention of biofouling

    NASA Astrophysics Data System (ADS)

    Pieracci, John Paul

    Membranes are widely used by the biotechnology industry in the separation and recovery of proteins from biological solutions. Fouling of membrane surfaces by irreversible protein adsorption during ultrafiltration causes loss of membrane permeability and can reduce membrane selectivity and lead to significant product loss through denaturation. In this work, low fouling poly(ether sulfone) (PES) ultrafiltration membranes were produced by ultraviolet (UV) assisted graft polymerization of hydrophilic vinyl monomers using a newly developed photochemical dip modification technique. This technique was developed to make the UV modification process more easily adaptable to continuous membrane manufacturing processes. A method was also developed to measure and track the degree of polymer grafting on the membrane surface using attenuated total reflection Fourier transform infrared spectroscopy (FTIR/ATR). Grafting the hydrophilic monomer N-vinyl-2-pyrrolidinone (NVP) onto the membrane surface increased surface wettability and produced membranes with the high wettability of regenerated cellulose membranes. The enhanced surface wettability significantly decreased irreversible adsorptive fouling during the filtration of the protein bovine serum albumin (BSA). In order to maintain the rejection of BSA after modification, PES chain scission was tightly controlled by regulating the UV wavelength range and the light intensity used. The UV reactor system was operated with 300 nm UV lamps and a benzene filter used to remove high energy wavelengths below 275 nm that were determined to cause severe loss of BSA rejection due to pore enlargement from extensive chain scission. Dip modification caused membrane permeability to decrease due to the grafted chains blocking the membrane pores. The use of a chain transfer agent during modification followed by ethanol cleaning increased modified membrane permeability, but BSA rejection was severely decreased. The resultant membranes produced by

  10. [Separation and determination of hesperidin in huoxiangzhengqi water by hollow fiber ultrafiltration-high performance liquid chromatography].

    PubMed

    An, Jing; Zhang, Fucheng; Lu, Yanfang; Jiang, Ye

    2011-02-01

    A simple hollow fiber based centrifuge ultrafiltration pretreatment procedure has been developed for the analysis of active components with high polarity in Chinese traditional and herbal drugs which usually contain macromolecule impurities. The procedure combined with HPLC was applied to the determination of hesperidin in Huoxiangzhengqi water. Sample solutions were purified by our patent hollow fiber centrifuge ultrafiltration device. Under the effect of the centrifgual force, micromolecules were removed from solution samples, thus it increased the service life of the column. The accuracy and repeatability of this method have also been improved. The separation was carried out on a Promosil C18 column (4.6 mm x 150 mm, 5 microm) with methanol -0.5% acetic acid solution (35:65) as mobile phase at a flow rate of 1.0 mL x min(-1). The detector wavelength was 283 nm and the column temperature was 30 degrees C. A good linear relation was obtained in the range of 4.69 - 150 mg x L(-1) (r = 0.999 7) and the average recovery was 103.0% with RSD of 1.9%. This method is simple, rapid and accurate, and it provides a simple and cheap ultrafiltration means for the analysis of the polar components in Chinese traditional and herbal drugs.

  11. Response surface-optimized removal of Reactive Red 120 dye from its aqueous solutions using polyethyleneimine enhanced ultrafiltration.

    PubMed

    Dasgupta, J; Singh, M; Sikder, J; Padarthi, V; Chakraborty, S; Curcio, S

    2015-11-01

    Retention of toxic dyes with molecular weights lower than the molecular weight cut-off (MWCO) of the ultrafiltration membranes can be improved through selective binding of the target dyes to a water-soluble polymer, followed by ultrafiltration of the macromolecular complexes formed. This method, often referred to as polymer enhanced ultrafiltration (PEUF), was investigated in the present study, using polyethyleneimine (PEI) as the chelating agent. Model azo dye Reactive Red 120 was selected as the poorly biodegradable, target contaminant, because of its frequent recalcitrant presence in colored effluents, and its eventual ecotoxicological impacts on the environment. The effects of the governing process factors, namely, cross flow rate, transmembrane pressure polymer to dye ratio and pH, on target dye rejection efficiency were meticulously examined. Additionally, each parameter level was statistically optimized using central composite design (CCD) from the response surface methodology (RSM) toolkit, with an objective to maximize performance efficiency. The results revealed high dye retention efficiency over 99%, accompanied with reasonable permeate flux over 100L/m(2)h under optimal process conditions. The estimated results were elucidated graphically through response surface (RS) plots and validated experimentally. The analyses clearly established PEUF as a novel, reasonably efficient and economical route for recalcitrant dye treatment.

  12. Removal of radionuclides in drinking water by membrane treatment using ultrafiltration, reverse osmosis and electrodialysis reversal.

    PubMed

    Montaña, M; Camacho, A; Serrano, I; Devesa, R; Matia, L; Vallés, I

    2013-11-01

    A pilot plant had been built to test the behaviour of ultrafiltration (UF), reverse osmosis (RO), and electrodialysis reversal (EDR) in order to improve the quality of the water supplied to Barcelona metropolitan area from the Llobregat River. This paper presents results from two studies to reduce natural radioactivity. The results from the pilot plant with four different scenarios were used to design the full-scale treatment plant built (SJD WTP). The samples taken at different steps of the treatment were analysed to determine gross alpha, gross beta and uranium activity. The results obtained revealed a significant improvement in the radiological water quality provided by both membrane techniques (RO and EDR showed removal rates higher than 60%). However, UF did not show any significant removal capacity for gross alpha, gross beta or uranium activities. RO was better at reducing the radiological parameters studied and this treatment was selected and applied at the full scale treatment plant. The RO treatment used at the SJD WTP reduced the concentration of both gross alpha and gross beta activities and also produced water of high quality with an average removal of 95% for gross alpha activity and almost 93% for gross beta activity at the treatment plant.

  13. Toxicity removal efficiency of decentralised sequencing batch reactor and ultra-filtration membrane bioreactors.

    PubMed

    Libralato, Giovanni; Volpi Ghirardini, Annamaria; Avezzù, Francesco

    2010-08-01

    As a consequence of the Water Framework Directive and Marine Strategy Framework Directive, there is now more focus on discharges from wastewater treatment plants both to transitional and marine-coastal waters. The constraint to encourage sustainable water policy to prevent water deterioration and reduce or stop discharges has entailed new requirements for existing wastewater treatment plants in the form of advanced wastewater treatment technologies as further suggested by the Integrated Pollution and Prevention Control Bureau. A whole toolbox of physico-chemical and ecotoxicological parameters to investigate commercial and mixed domestic and industrial discharges was considered to check the efficiency of an Activated-Sludge Sequencing Batch Reactor (AS-SBR) and two Ultra-Filtration Membrane Biological Reactors (UF-MBRs) on a small scale decentralised basis. All discharges were conveyed into Venice lagoon (Italy), one of the widest impacted Mediterranean transitional environment. The UF-MBRs were able to provide good quality effluents potentially suitable for non-potable reuse, as well as reducing specific inorganic micro-pollutants concentration (e.g. metals). Conversely, the AS-SBR showed unpredictable and discontinuous removal abilities. PMID:20619431

  14. ACE-I Inhibitory Activity from Phaseolus lunatus and Phaseolus vulgaris Peptide Fractions Obtained by Ultrafiltration.

    PubMed

    Betancur-Ancona, David; Dávila-Ortiz, Gloria; Chel-Guerrero, Luis Antonio; Torruco-Uco, Juan Gabriel

    2015-11-01

    The involvement of angiotensin-I-converting enzyme (ACE-I) as one of the mechanisms controlling blood pressure is being studied to find alternative means of control of hypertension on human beings. On the market there are synthetic drugs that can control it, but these can cause undesirable health side effects. In this work was assessed the fractionation by ultrafiltration of the Lima bean (Phaseolus lunatus) and Jamapa bean (Phaseolus vulgaris), protein hydrolysates obtained with Alcalase(®) and Flavourzyme(®) on ACE-I inhibitory activity. Four membranes of different molecular cutoffs (10, 5, 3, and 1 kDa) were used. Fractions that had a higher inhibitory activity in both legumes were denominated as E (<1 kDa) with IC50 of 30.3 and 51.8 μg/mL values for the P. lunatus with Alcalase and Flavourzyme, respectively, and for the Phaseolus vulgaris with Alcalase and Flavourzyme with about 63.8 and 65.8 μg/mL values, respectively. The amino acid composition of these fractions showed residues in essential amino acids, which make a good source of energy and amino acids. On the other hand, the presence of hydrophobic amino acids such as V and P is a determining factor in the ACE-I inhibitor effect. The results suggest the possibility of obtaining and utilizing these peptide fractions in the development and innovation of a functional product that helps with treatment and/or prevention of hypertension.

  15. Selective separation and concentration of antihypertensive peptides from rapeseed protein hydrolysate by electrodialysis with ultrafiltration membranes.

    PubMed

    He, Rong; Girgih, Abraham T; Rozoy, Elodie; Bazinet, Laurent; Ju, Xing-Rong; Aluko, Rotimi E

    2016-04-15

    Rapeseed protein isolate was subjected to alcalase digestion to obtain a protein hydrolysate that was separated into peptide fractions using electrodialysis with ultrafiltration membrane (EDUF) technology. The EDUF process (6h duration) led to isolation of three peptide fractions: anionic (recovered in KCl-1 compartment), cationic (recovered in KCl-2 compartment), and those that remained in the feed compartment, which was labeled final rapeseed protein hydrolysate (FRPH). As expected the KCl-1 peptides were enriched in negatively-charged (43.57%) while KCl-2 contained high contents of positively-charged (28.35%) amino acids. All the samples inhibited angiotensin converting enzyme (ACE) and renin activities in dose-dependent manner with original rapeseed protein hydrolysate having the least ACE-inhibitory IC50 value of 0.0932±0.0037 mg/mL while FRPH and KCl-2 had least renin-inhibitory IC50 values of 0.47±0.05 and 0.55±0.06 mg/mL, respectively. Six hours after oral administration (100 mg/kg body weight) to spontaneously hypertensive rats, the FRPH produced the maximum systolic blood pressure reduction of -51 mmHg.

  16. Separation and characterization of alpha-chain subunits from tilapia (Tilapia zillii) skin gelatin using ultrafiltration.

    PubMed

    Chen, Shulin; Tang, Lanlan; Su, Wenjin; Weng, Wuyin; Osako, Kazufumi; Tanaka, Munehiko

    2015-12-01

    Alpha-chain subunits were separated from tilapia skin gelatin using ultrafiltration, and the physicochemical properties of obtained subunits were investigated. As a result, α1-subunit and α2-subunit could be successfully separated by 100 kDa MWCO regenerated cellulose membranes and 150 kDa MWCO polyethersulfone membranes, respectively. Glycine was the most dominant amino acid in both α1-subunit and α2-subunit. However, the tyrosine content was higher in α2-subunit than in α1-subunit, resulting in strong absorption near 280 nm observed in the UV absorption spectrum. Based on the DSC analysis, it was found that the glass transition temperatures of gelatin, α1-subunit and α2-subunit were 136.48 °C, 126.77 °C and 119.43 °C, respectively. Moreover, the reduced viscosity and denaturation temperature of α1-subunit were higher than those of α2-subunit, and the reduced viscosity reached the highest when α-subunits were mixed with α1/α2 ratio of approximately 2, suggesting that α1-subunit plays a more important role in the thermostability of gelatin than α2-subunit.

  17. Prevention of PVDF ultrafiltration membrane fouling by coating MnO2 nanoparticles with ozonation.

    PubMed

    Yu, Wenzheng; Brown, Matthew; Graham, Nigel J D

    2016-01-01

    Pre-treatment is normally required to reduce or control the fouling of ultrafiltration (UF) membranes in drinking water treatment process. Current pre-treatment methods, such as coagulation, are only partially effective to prevent long-term fouling. Since biological activities are a major contributor to accumulated fouling, the application of an oxidation/disinfection step can be an effective complement to coagulation. In this study, a novel pre-treatment method has been evaluated at laboratory scale consisting of the addition of low dose ozone into the UF membrane tank after coagulation and the use of a hollow-fibre membrane coated with/without MnO2 nanoparticles over a test period of 70 days. The results showed that there was minimal fouling of the MnO2 coated membrane (0.5 kPa for 70 days), while the uncoated membrane experienced both reversible and irreversible fouling. The difference was attributed to the greatly reduced presence of bacteria and organic matter because of the catalytic decomposition of ozone to hydroxyl radicals and increase of the hydrophilicity of the membrane surface. In particular, the MnO2 coated membrane had a much thinner cake layer, with significantly less polysaccharides and proteins, and much less accumulated organic matter within the membrane pores. PMID:27436142

  18. Exergy analysis of an industrial-scale ultrafiltrated (UF) cheese production plant: a detailed survey

    NASA Astrophysics Data System (ADS)

    Nasiri, Farshid; Aghbashlo, Mortaza; Rafiee, Shahin

    2016-05-01

    In this study, a detailed exergy analysis of an industrial-scale ultrafiltrated (UF) cheese production plant was conducted based on actual operational data in order to provide more comprehensive insights into the performance of the whole plant and its main subcomponents. The plant included four main subsystems, i.e., steam generator (I), above-zero refrigeration system (II), Bactocatch-assisted pasteurization line (III), and UF cheese production line (IV). In addition, this analysis was aimed at quantifying the exergy destroyed in processing a known quantity of the UF cheese using the mass allocation method. The specific exergy destruction of the UF cheese production was determined at 2330.42 kJ/kg. The contributions of the subsystems I, II, III, and IV to the specific exergy destruction of the UF cheese production were computed as 1337.67, 386.18, 283.05, and 323.51 kJ/kg, respectively. Additionally, it was observed through the analysis that the steam generation system had the largest contribution to the thermodynamic inefficiency of the UF cheese production, accounting for 57.40 % of the specific exergy destruction. Generally, the outcomes of this survey further manifested the benefits of applying exergy analysis for design, analysis, and optimization of industrial-scale dairy processing plants to achieve the most cost-effective and environmentally-benign production strategies.

  19. Prevention of PVDF ultrafiltration membrane fouling by coating MnO2 nanoparticles with ozonation

    NASA Astrophysics Data System (ADS)

    Yu, Wenzheng; Brown, Matthew; Graham, Nigel. J. D.

    2016-07-01

    Pre-treatment is normally required to reduce or control the fouling of ultrafiltration (UF) membranes in drinking water treatment process. Current pre-treatment methods, such as coagulation, are only partially effective to prevent long-term fouling. Since biological activities are a major contributor to accumulated fouling, the application of an oxidation/disinfection step can be an effective complement to coagulation. In this study, a novel pre-treatment method has been evaluated at laboratory scale consisting of the addition of low dose ozone into the UF membrane tank after coagulation and the use of a hollow-fibre membrane coated with/without MnO2 nanoparticles over a test period of 70 days. The results showed that there was minimal fouling of the MnO2 coated membrane (0.5 kPa for 70 days), while the uncoated membrane experienced both reversible and irreversible fouling. The difference was attributed to the greatly reduced presence of bacteria and organic matter because of the catalytic decomposition of ozone to hydroxyl radicals and increase of the hydrophilicity of the membrane surface. In particular, the MnO2 coated membrane had a much thinner cake layer, with significantly less polysaccharides and proteins, and much less accumulated organic matter within the membrane pores.

  20. Ultrafiltration/nanofiltration for the tertiary treatment of leather industry effluents.

    PubMed

    Streit, Katia F; Ferreira, Jane Zoppas; Bernardes, Andréa M; Norberta De Pinho, Maria

    2009-12-15

    Biologically treated effluents from the leather industry pose severe problems for the environment due in part to both the inorganic charge and the high nitrogen content associated with the organic charge. Pressure-driven membrane processes, namely ultrafiltration/nanofiltration (UF/NF) technology, were investigated for their selective retention of the organics and permeation of the inorganic fraction. Permeation experiments were carried out with two model solutions representative of a treated tannery effluent. UF and NF of these model solutions were assessed in terms of both their inorganic/organic fractionation capability and their permeation productivity. The UF membranes with MWCOs ranging from 10,000 to 1000 Da yield retentate streams enriched in organic compounds and permeate streams enriched in salts. Despite their high capacity for pure water permeation, they displayed low permeation fluxes, as the result of concentration polarization and fouling phenomena. NF 200 and NF 270 membranes associated fractionation capability with high permeation rates. Furthermore, these membranes demonstrated the highest permeate fluxes -30 kg/h/m(2) and 16 kg/h/m(2) for different model solutions, at the transmembrane pressure of 8 bar. Although these membranes had lower hydraulic permeabilities relative to the other membranes tested, they exhibited the best characteristics in terms of minimization of colloidal fouling.

  1. Modified Ultrafiltration During Cardiopulmonary Bypass and Postoperative Course of Pediatric Cardiac Surgery

    PubMed Central

    Ziyaeifard, Mohsen; Alizadehasl, Azin; Massoumi, Gholamreza

    2014-01-01

    Context: The use of cardiopulmonary bypass (CPB) provokes the inflammatory responses associated with ischemic/reperfusion injury, hemodilution and other agents. Exposure of blood cells to the bypass circuit surface starts a systemic inflammatory reaction that may causes post-CPB organ dysfunction, particularly in lungs, heart and brain. Evidence Acquisition: We investigated in the MEDLINE, PUBMED, and EMBASE databases and Google scholar for every available article in peer reviewed journals between 1987 and 2013, for related subjects to CPB with conventional or modified ultrafiltration (MUF) in pediatrics cardiac surgery patients. Results: MUF following separation from extracorporeal circulation (ECC) provides well known advantages in children with improvements in the hemodynamic, pulmonary, coagulation and other organs functions. Decrease in blood transfusion, reduction of total body water, and blood loss after surgery, are additional benefits of MUF. Conclusions: Consequently, MUF has been associated with attenuation of morbidity after pediatric cardiac surgery. In this review, we tried to evaluate the current evidence about MUF on the organ performance and its effect on post-CPB morbidity in pediatric patients. PMID:25478538

  2. Recovery of diverse microbes in high turbidity surface water samples using dead-end ultrafiltration.

    PubMed

    Mull, Bonnie; Hill, Vincent R

    2012-12-01

    Dead-end ultrafiltration (DEUF) has been reported to be a simple, field-deployable technique for recovering bacteria, viruses, and parasites from large-volume water samples for water quality testing and waterborne disease investigations. While DEUF has been reported for application to water samples having relatively low turbidity, little information is available regarding recovery efficiencies for this technique when applied to sampling turbid water samples such as those commonly found in lakes and rivers. This study evaluated the effectiveness of a DEUF technique for recovering MS2 bacteriophage, enterococci, Escherichia coli, Clostridium perfringens, and Cryptosporidium parvum oocysts in surface water samples having elevated turbidity. Average recovery efficiencies for each study microbe across all turbidity ranges were: MS2 (66%), C. parvum (49%), enterococci (85%), E. coli (81%), and C. perfringens (63%). The recovery efficiencies for MS2 and C. perfringens exhibited an inversely proportional relationship with turbidity, however no significant differences in recovery were observed for C. parvum, enterococci, or E. coli. Although ultrafilter clogging was observed, the DEUF method was able to process 100-L surface water samples at each turbidity level within 60 min. This study supports the use of the DEUF method for recovering a wide array of microbes in large-volume surface water samples having medium to high turbidity.

  3. Prevention of PVDF ultrafiltration membrane fouling by coating MnO2 nanoparticles with ozonation

    PubMed Central

    Yu, Wenzheng; Brown, Matthew; Graham, Nigel. J. D.

    2016-01-01

    Pre-treatment is normally required to reduce or control the fouling of ultrafiltration (UF) membranes in drinking water treatment process. Current pre-treatment methods, such as coagulation, are only partially effective to prevent long-term fouling. Since biological activities are a major contributor to accumulated fouling, the application of an oxidation/disinfection step can be an effective complement to coagulation. In this study, a novel pre-treatment method has been evaluated at laboratory scale consisting of the addition of low dose ozone into the UF membrane tank after coagulation and the use of a hollow-fibre membrane coated with/without MnO2 nanoparticles over a test period of 70 days. The results showed that there was minimal fouling of the MnO2 coated membrane (0.5 kPa for 70 days), while the uncoated membrane experienced both reversible and irreversible fouling. The difference was attributed to the greatly reduced presence of bacteria and organic matter because of the catalytic decomposition of ozone to hydroxyl radicals and increase of the hydrophilicity of the membrane surface. In particular, the MnO2 coated membrane had a much thinner cake layer, with significantly less polysaccharides and proteins, and much less accumulated organic matter within the membrane pores. PMID:27436142

  4. Evaluation and validation of virus removal by ultrafiltration during the production of diaspirin crosslinked haemoglobin (DCLHb).

    PubMed

    Azari, M; Boose, J A; Burhop, K E; Camacho, T; Catarello, J; Darling, A; Ebeling, A A; Estep, T N; Pearson, L; Guzder, S; Herren, J; Ogle, K; Paine, J; Rohn, K; Sarajari, R; Sun, C S; Zhang, L

    2000-06-01

    Virus retention during ultrafiltration through A/G Technology filter cartridges was investigated to characterize the removal process and validate the degree of virus titre reduction during the filtration of red blood cell haemolysates performed as part of the production of diaspirin crosslinked haemoglobin (DCLHb). When viruses were suspended in phosphate buffered saline solution, retention was greater with larger sized viruses and smaller filter pore size. Virus titre was maintained at starting levels in the filter retentate circuit during the course of filtration, suggesting that the virus removal mechanism is predominantly size exclusion. Evaluation of specific processing variables indicated that the retention of phiX174 virus was increased in the presence of red blood cell haemolysate or at high membrane crossflow rates and transmembrane pressures, while the retention of EMC virus was less sensitive to variations in these parameters. Using these results to design a validation protocol, log reduction values of >7.9 were demonstrated for the retention of human immunodeficiency virus, pseudorabies virus and bovine viral diarrhoea viruses, 7.6 for hepatitis A virus, and 4.2 for porcine parvovirus. It was also shown that the retention of viruses was maintained during repetitive use of the same filter cartridge. PMID:10885615

  5. Evaluation of novel large cut-off ultrafiltration membranes for adenovirus serotype 5 (Ad5) concentration.

    PubMed

    Nestola, Piergiuseppe; Martins, Duarte L; Peixoto, Cristina; Roederstein, Susanne; Schleuss, Tobias; Alves, Paula M; Mota, José P B; Carrondo, Manuel J T

    2014-01-01

    The purification of virus particles and viral vectors for vaccine and gene therapy applications is gaining increasing importance in order to deliver a fast, efficient, and reliable production process. Ultrafiltration (UF) is a widely employed unit operation in bioprocessing and its use is present in several steps of the downstream purification train of biopharmaceuticals. However, to date few studies have thoroughly investigated the performance of several membrane materials and cut-offs for virus concentration/diafiltration. The present study aimed at developing a novel class of UF cassettes for virus concentration/diafiltration. A detailed study was conducted to evaluate the effects of (i) membrane materials, namely polyethersulfone (PES), regenerated cellulose (RC), and highly cross-linked RC (xRC), (ii) nominal cut-off, and (iii) UF device geometry at different production scales. The results indicate that the xRC cassettes with a cut-off of approximately 500 kDa are able to achieve a 10-fold concentration factor with 100% recovery of particles with a process time twice as fast as that of a commercially available hollow fiber. DNA and host cell protein clearances, as well as hydraulic permeability and fouling behavior, were also assessed.

  6. Performance enhancement of polyvinyl chloride ultrafiltration membrane modified with graphene oxide.

    PubMed

    Zhao, Yuanyuan; Lu, Jiaqi; Liu, Xuyang; Wang, Yudan; Lin, Jiuyang; Peng, Na; Li, Jingchun; Zhao, Fangbo

    2016-10-15

    A novel polyvinyl chloride (PVC) membrane was modified with graphene oxide (GO) via phase inversion method to improve its hydrophilicity and mechanical properties. The GO presented a large amount of hydrophilic groups after the modification through the modified Hummers method. It was observed that with the addition of low fraction of GO powder, the GO/PVC hybrid membranes exhibited a significant enhancement in hydrophilicity, water flux, and mechanical properties. With optimal dosage (0.1wt%), the pure water flux of GO/PVC membrane increased from 232.6L/(m(2)hbar) to 430.0L/(m(2)hbar) and the tensile strength increased from 231.3cN to 305.3cN. The improved properties of the PVC/GO hybrid membranes are mainly attributed to the strong hydrophilicity of functional groups on the GO surface, indicating that GO has a promising candidate for modification of PVC ultrafiltration membranes in wastewater treatment.

  7. Surface modification of ultrafiltration membranes by grafting glycine-functionalized PVA based on polydopamine coatings

    NASA Astrophysics Data System (ADS)

    Li, Fang; Ye, Jianfeng; Yang, Linming; Deng, Chunhua; Tian, Qing; Yang, Bo

    2015-08-01

    Due to the ease of processing and stability during filtration, polydopamine (PD) coatings with grafted hydrophilic polymers have recently received significant attention. In this study, glycine-functionalized PVA was synthesized and grafted to a PD-coated ultrafiltration (UF) membrane to improve its performance during wastewater filtration. The membranes were modified by grafting PD with glycine-functionalized PVA (PD-g-PVA), and the resultant materials were characterized using surface morphology analyses, contact angle measurements, flux, oil/water emulsion separation tests, and grafted layer stability tests. The performance of the PD-g-PVA membrane was compared to that of the membrane modified with PD-g-polyethylene glycol (PEG). After grafting the PD-g-PVA, the surface roughness of the membranes decreased significantly. The grafted PVA layer, which was stable under acidic and alkaline conditions, protected the PD layer. The filtration experiments with an oil/water emulsion indicated that modifying the glycine-functionalized PVA by grafting can significantly improve the antifouling ability of membranes.

  8. Novel Applications of Modified Ultrafiltration and Autologous Priming Techniques to Reduce Blood Product Exposure on ECMO

    PubMed Central

    Neal, James R.; Blau, Caitlin L.; Cornelius, Amanda M.; Pike, Roxann B.; Dearani, Joseph A.; Mora, Bassem N.

    2016-01-01

    Abstract: Patients needing the assistance of extracorporeal membrane oxygenation (ECMO) are at risk of hemodilution and, in some instances, may require exposure to large amounts of allogeneic blood products. Patient outcomes can be improved by taking steps to reduce transfusions and hemodilution. Currently, modified ultrafiltration (MUF) is used across the world to reduce hemodilution after cardiopulmonary bypass (CPB). Another common technique during bypass initiation is autologous priming. By applying modified versions of these techniques, ECMO patients may potentially benefit. Usually, patients requiring immediate transition from CPB to ECMO are not stable enough to tolerate MUF. Through alterations of the CPB and ECMO circuit tubing, MUF can be performed once on ECMO. Another technique to potentially lower the transfusion requirements for ECMO patients is a complete circuit blood transfer during an ECMO circuit exchange. While selective component changes are preferred if possible, occasionally a complete circuit change must be done. To minimize hemodilution or prevent priming with blood products, the original ECMO circuit's blood can be transferred to the new ECMO circuit before connecting to the patient. Both of these techniques, in our opinion, helped to reduce the number of transfusions that our ECMO patients have seen during these critical time periods. PMID:27134305

  9. Spectroscopic study of humic acids fractionated by means of tangential ultrafiltration

    NASA Astrophysics Data System (ADS)

    Francioso, O.; Sánchez-Cortés, S.; Casarini, D.; Garcia-Ramos, J. V.; Ciavatta, C.; Gessa, C.

    2002-05-01

    Different chemical and spectroscopic techniques—diffuse reflectance infrared Fourier transform (DRIFT), surface-enhanced Raman spectroscopy (SERS), and 1H, 13C nuclear magnetic resonance (NMR) have been applied to investigate a peat humic acid (HA) separated by tangential ultrafiltration into different nominal molecular weight (NMW) fractions. Each fraction analyzed showed a characteristic DRIFT and NMR pattern. High nominal molecular weight fractions were mainly characterized by long chains of methyl and methylene groups and poorly substituted aromatic rings, while in low nominal molecular weight fractions (L-NMW), phenolic and oxygen-containing groups were predominant. A comparative study on fractions before and after treatment with 0.5 M HCl was carried out. Purified fractions showed either an increase in the carboxylate and phenolic OH groups or an improvement in signal-to-noise ratio of their NMR spectra. The SERS study of NMW fractions allowed significative information on structure and conformation of these fractions. In particular, L-NMW fractions showed a great structural modification, when different alkaline extractants or treatment with HCl were used. Humic-like substances obtained by catechol and gallic acid polymerization on metal surface were investigated using SERS. The SERS spectra of these polymers were compared and discussed with those of NMW HA fractions.

  10. Plasma deposition of silver nanoparticles on ultrafiltration membranes: antibacterial and anti-biofouling properties

    PubMed Central

    Cruz, Mercedes Cecilia; Ruano, Gustavo; Wolf, Marcus; Hecker, Dominic; Vidaurre, Elza Castro; Schmittgens, Ralph; Rajal, Verónica Beatriz

    2015-01-01

    A novel and versatile plasma reactor was used to modify Polyethersulphone commercial membranes. The equipment was applied to: i) functionalize the membranes with low-temperature plasmas, ii) deposit a film of poly(methyl methacrylate) (PMMA) by Plasma Enhanced Chemical Vapor Deposition (PECVD) and, iii) deposit silver nanoparticles (SNP) by Gas Flow Sputtering. Each modification process was performed in the same reactor consecutively, without exposure of the membranes to atmospheric air. Scanning electron microscopy and transmission electron microscopy were used to characterize the particles and modified membranes. SNP are evenly distributed on the membrane surface. Particle fixation and transport inside membranes were assessed before- and after-washing assays by X-ray photoelectron spectroscopy depth profiling analysis. PMMA addition improved SNP fixation. Plasma-treated membranes showed higher hydrophilicity. Anti-biofouling activity was successfully achieved against Gram-positive (Enterococcus faecalis) and -negative (Salmonella Typhimurium) bacteria. Therefore, disinfection by ultrafiltration showed substantial resistance to biofouling. The post-synthesis functionalization process developed provides a more efficient fabrication route for anti-biofouling and anti-bacterial membranes used in the water treatment field. To the best of our knowledge, this is the first report of a gas phase condensation process combined with a PECVD procedure in order to deposit SNP on commercial membranes to inhibit biofouling formation. PMID:26166926

  11. Characteristics of Filter Cake Exfoliation in Upward Ultrafiltration of Nanoparticle Suspensions

    PubMed Central

    Mukai, Yasuhito; Nishio, Aya

    2011-01-01

    Downward and upward ultrafiltration (UF) was performed using the suspensions of nanosized colloidal silica with different particle diameters and their filtration rates were compared. In downward UF, the filtration rate decreases as the particle diameter decreases because the specific filtration resistance of the filter cake becomes significantly higher. In contrast, the filtration rate in upward UF increases with the decrease in the particle diameter because the filter cake consisting of small particles is exfoliated much more easily under the influence of gravity than that of large ones. In order to evaluate the characteristics of the filter cake exfoliation, the steady filtration rate in the upward mode was measured. The steady filtration rate has a tendency to decrease with particle concentration as well as mean particle diameter. Therefore, when the small particles are added into a given concentration of large particle suspension, the mean particle diameter decreases and the total particle concentration increases due to the dosage of small particles. This results in a maximum of the steady filtration rate at a certain dosage of small particles. Moreover, an estimation equation was proposed for predicting the steady filtration rate in upward UF of colloidal silica suspensions with various mean particle diameters and total particle concentrations. PMID:24957496

  12. Effect of gamma-ray irradiation at low doses on the performance of PES ultrafiltration membrane

    NASA Astrophysics Data System (ADS)

    Zhang, Xue; Niu, Lixia; Li, Fuzhi; Yu, Suping; Zhao, Xuan; Hu, Hongying

    2016-10-01

    The influence of gamma irradiation on the performance of polyether sulfone (PES) ultrafiltration (UF) membrane was investigated at low absorbed doses (0-75 kGy) using a cobalt source. The performance of the UF membranes was tested using low level radioactive wastewater (LLRW) containing three types of surfactants (anionic, cationic and nonionic surfactants). The physical and chemical properties of membrane surface were analyzed, and relationships between these properties and separation performance and fouling characteristics were determined. At 10-75 kGy irradiation, there were no significant changes observed in the membrane surface roughness or polymer functional groups, however the contact angle decreased sharply from 92° to ca. 70° at irradiation levels as low as 10 kGy. When membranes were exposed to the surfactant-containing LLRW, the flux decreased more sharply for higher dosed irradiated membranes, while flux in virgin membranes increased during the filtration processes. The study highlights that fouling properties of membrane may be changed due to the changes of surface hydrophilicity at low dose irradiation, while other surface properties and retentions remain stable. Therefore, a membrane fouling test with real or simulated wastewater is recommended to fully evaluate the membrane irradiation resistance.

  13. Pilot-scale ultrafiltration testing for the F and H area effluent treatment facility

    SciTech Connect

    Kessler, J.L.

    1984-09-25

    An F and H Area Effluent Treatment Facility (F/H ETF) is being designed to treat low activity aqueous effluents which are produced from F and H Area daily operations. The treatment scheme for the F/H ETF will include pretreatment (pH adjustment and filtration) followed by Reverse Osmosis and/or Ion Exchange to remove dissolved species. Several alternative treatment processes are being considered for the F/H ETF. One of the alternatives in the pretreatment step is tubular Ultrafiltration (UF), using a dynamically formed zirconium oxide membrane supported on a porous stainless steel backing. Pilot-scale testing with a single membrane module (13 ft/sup 2/ area) and 200-Area effluent simulant has demonstrated that UF is a viable filtration option for the F/H ETF. UF testing at TNX has defined the operating conditions necessary for extended operation and also demonstrated excellent filtration performance (filtrate SDI <1). UF operates at a 100 GFD (gallons/ft/sup 2//day) flux and will provide excellent pretreatment for both reverse osmosis and ion exchange. 2 refs.

  14. Modification of ultrafiltration membrane with nanoscale zerovalent iron layers for humic acid fouling reduction.

    PubMed

    Ma, Baiwen; Yu, Wenzheng; Jefferson, William A; Liu, Huijuan; Qu, Jiuhui

    2015-03-15

    Nanoscale zerovalent iron (NZVI) was layered onto ultrafiltration (UF) membrane surface and tested for antifouling properties using humic acid (HA). Scanning electron microscopy showed that a relatively homogeneous layer was formed across the membrane surface by NZVI particles. Strong adhesion was observed between NZVI and UF membrane used. HA was significantly removed and membrane flux was increased in the presence of NZVI layer. Increased loadings of NZVI onto the membrane surface increased resistance to fouling while slightly reducing the clean water permeability of the membrane. However, the pore size of the layer formed by pristine NZVI was large, resulting in more chances of HA molecules getting to the membrane surface even blocking the membrane pores at the beginning. Membrane loaded with NZVI layer performed much better under acidic conditions. During NZVI synthesis, specific surface area of NZVI particle increased with increasing the ratio of ethanol (Vethanol/Vsolution), which also gradually decreased the average pore size of NZVI layer. As a result, the corresponding membrane flux steadily increased. Additionally, the results for permeate samples under different conditions showed that large molecular weight (MW, >30 kDa) and medium MW HA molecules (3-30 kDa) were removed much faster than those of small MW HA molecules (<3 kDa). PMID:25613411

  15. Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing.

    PubMed

    Wardrip, Nathaniel C; Arnusch, Christopher J

    2016-01-01

    Minimization and management of membrane fouling is a formidable challenge in diverse industrial processes and other practices that utilize membrane technology. Understanding the fouling process could lead to optimization and higher efficiency of membrane based filtration. Here we show the design and fabrication of an automated three-dimensionally (3-D) printed microfluidic cross-flow filtration system that can test up to 4 membranes in parallel. The microfluidic cells were printed using multi-material photopolymer 3-D printing technology, which used a transparent hard polymer for the microfluidic cell body and incorporated a thin rubber-like polymer layer, which prevents leakages during operation. The performance of ultrafiltration (UF), and nanofiltration (NF) membranes were tested and membrane fouling could be observed with a model foulant bovine serum albumin (BSA). Feed solutions containing BSA showed flux decline of the membrane. This protocol may be extended to measure fouling or biofouling with many other organic, inorganic or microbial containing solutions. The microfluidic design is especially advantageous for testing materials that are costly or only available in small quantities, for example polysaccharides, proteins, or lipids due to the small surface area of the membrane being tested. This modular system may also be easily expanded for high throughput testing of membranes.

  16. Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing.

    PubMed

    Wardrip, Nathaniel C; Arnusch, Christopher J

    2016-01-01

    Minimization and management of membrane fouling is a formidable challenge in diverse industrial processes and other practices that utilize membrane technology. Understanding the fouling process could lead to optimization and higher efficiency of membrane based filtration. Here we show the design and fabrication of an automated three-dimensionally (3-D) printed microfluidic cross-flow filtration system that can test up to 4 membranes in parallel. The microfluidic cells were printed using multi-material photopolymer 3-D printing technology, which used a transparent hard polymer for the microfluidic cell body and incorporated a thin rubber-like polymer layer, which prevents leakages during operation. The performance of ultrafiltration (UF), and nanofiltration (NF) membranes were tested and membrane fouling could be observed with a model foulant bovine serum albumin (BSA). Feed solutions containing BSA showed flux decline of the membrane. This protocol may be extended to measure fouling or biofouling with many other organic, inorganic or microbial containing solutions. The microfluidic design is especially advantageous for testing materials that are costly or only available in small quantities, for example polysaccharides, proteins, or lipids due to the small surface area of the membrane being tested. This modular system may also be easily expanded for high throughput testing of membranes. PMID:26968008

  17. Effect of coagulation on fouling rate and cleanability of ultrafiltration membranes

    SciTech Connect

    Ying, W.; Tansel, B.

    1996-11-01

    Among the membrane filtration techniques, continuous cross-flow ultrafiltration (UF) is an innovative method to separate solid/liquid or liquid/liquid phases at a lower pressure of 5--150 psi compared to reverse osmosis (RO) in which the applied pressure is an order of magnitude higher. Recently, attempts have been made to combine processes of UF and other treatments for many applications. However, there is very little knowledge about the filtration process which combined coagulation and UF, and very few attempts have been made to apply coagulated UF to the treatment of fuel oil contaminated water. During the UF treatment of organic contaminants rapid declines in flux will occur due to the membrane fouling. Oil as a foulant plants an important role in the flux decrease. However, there are very limited pretreatment processes which can effectively remove fuel oil from water and hence solve the fouling problem. The purpose of the study was to examine the effectiveness of a simple method for reducing UF membrane fouling which is caused by fuel oils in feed water. In this simple method, a coagulant was added into the feed water contaminated by fuel oils during the cross-flow UF treatment (coagulated UF). In this investigation, turbidity and petroleum hydrocarbon removal efficiency, permeate flux and membrane fouling potential were evaluated by a series of batch experiments. The mechanisms by which the membrane fouling was significantly reduced by coagulation were discussed.

  18. Preparation and characterization of thermally stable copoly(phthalazinone biphenyl ether sulfone) hollow fiber ultrafiltration membranes

    NASA Astrophysics Data System (ADS)

    Liu, Peng; Zhang, Shouhai; Wang, Yutian; Lu, Yan; Jian, Xigao

    2015-04-01

    Novel thermally stable copoly(phthalazinone biphenyl ether sulfone) (PPBES) hollow fiber ultrafiltration (UF) membranes were successfully fabricated by the dry/wet phase inversion technique. The effects of polymer dope formulation (i.e., the PPBES concentration, different types and contents of additives) and fiber spinning conditions (i.e., air gap distance, coagulation bath temperature) on the morphologies and separation performance of PPBES hollow fiber UF membranes were investigated, respectively. It was found that the water flux of hollow fiber membrane decreased with the increase of PPBES concentration or EGME content in casting solution, while the rejection of PEG increased. However, the PPBES hollow fiber UF prepared with LiCl as inorganic small molecule additive exhibited different phenomena. In addition, the decrease of air gap distance or the increase of coagulation bath temperature could improve the water flux of UF membrane while reduce the rejection of PEG. Moreover, the thermal stability of the PPBES hollow fiber UF membranes was investigated. The water flux of PPBES membrane increased dramatically from 155 to 428 L m-2 h-1 without significant decrease of rejection when the temperature of feed solution increased from 20 °C to 95 °C.

  19. Fabrication of catalytic membranes for the treatment of drinking water using combined ozonation and ultrafiltration.

    PubMed

    Karnik, Bhavana S; Davies, Simon H; Baumann, Melissa J; Masten, Susan J

    2005-10-01

    The removal of disinfection byproducts and their precursors was investigated using a combined ozonation-ultrafiltration system. A commercial membrane was coated 20 or 40 times with iron oxide nanoparticles (4-6 nm in diameter). With this membrane, the concentration of dissolved organic carbon was reduced by >85% and the concentrations of simulated distribution system total trihalomethanes and simulated distribution system halo acetic acids decreased by up to 90% and 85%, respectively. When the coated membrane was used, the concentrations of aldehydes, ketones, and ketoacids in the permeate were reduced by >50% as compared to that obtained with the uncoated membranes. Hydroxyl or other radicals produced at the iron oxide coated membrane surface as a result of ozone decomposition are believed to have enhanced the degradation of the natural organic matter, thereby reducing the concentration of disinfection byproducts. While increasing the number of times the membrane was coated from 20 to 40 did not significantly reduce the concentrations of most of the parameters measured, it did result in a significant decrease in the concentrations of ozonation byproducts. Increasing the sintering temperature from 500 to 900 degrees C also resulted in an improvement in the removal of the ozonation byproducts.

  20. Structure and rheological behavior of casein micelle suspensions during ultrafiltration process

    NASA Astrophysics Data System (ADS)

    Pignon, F.; Belina, G.; Narayanan, T.; Paubel, X.; Magnin, A.; Gésan-Guiziou, G.

    2004-10-01

    The stability and mechanism underlying the formation of deposits of casein micelles during ultrafiltration process were investigated by small-angle and ultra small-angle x-ray scattering (SAXS and USAXS). The casein micelle dispersions consisted of phospho-caseinate model powders and the measurements probed length scales ranging from 1 to 2000 nm. Rheometric and frontal filtration measurements were combined with SAXS to establish the relationship between the rheological behavior of deposits (shear and/or compression) and the corresponding microstructure. The results revealed two characteristic length scales for the equilibrium structure with radius of gyrations Rg, about 100 and 5.6 nm pertaining to the globular micelles and their non-globular internal structure, respectively. The SAXS measurements further indicated that the increase of temperature from 20 to 70 °C or the decrease of pH from 6.6 to 6 lead to agglomeration of the globular micelles. In situ scattering measurements showed that the decrease of permeation flows is directly related to the deformation and compression of the micelles in the immediate vicinity of the membrane.

  1. Novel Applications of Modified Ultrafiltration and Autologous Priming Techniques to Reduce Blood Product Exposure on ECMO.

    PubMed

    Neal, James R; Blau, Caitlin L; Cornelius, Amanda M; Pike, Roxann B; Dearani, Joseph A; Mora, Bassem N

    2016-03-01

    Patients needing the assistance of extracorporeal membrane oxygenation (ECMO) are at risk of hemodilution and, in some instances, may require exposure to large amounts of allogeneic blood products. Patient outcomes can be improved by taking steps to reduce transfusions and hemodilution. Currently, modified ultrafiltration (MUF) is used across the world to reduce hemodilution after cardiopulmonary bypass (CPB). Another common technique during bypass initiation is autologous priming. By applying modified versions of these techniques, ECMO patients may potentially benefit. Usually, patients requiring immediate transition from CPB to ECMO are not stable enough to tolerate MUF. Through alterations of the CPB and ECMO circuit tubing, MUF can be performed once on ECMO. Another technique to potentially lower the transfusion requirements for ECMO patients is a complete circuit blood transfer during an ECMO circuit exchange. While selective component changes are preferred if possible, occasionally a complete circuit change must be done. To minimize hemodilution or prevent priming with blood products, the original ECMO circuit's blood can be transferred to the new ECMO circuit before connecting to the patient. Both of these techniques, in our opinion, helped to reduce the number of transfusions that our ECMO patients have seen during these critical time periods. PMID:27134305

  2. Determination of marbofloxacin in plasma and synovial fluid by ultrafiltration followed by HPLC-MS/MS.

    PubMed

    Montesano, Camilla; Curini, Roberta; Sergi, Manuel; Compagnone, Dario; Celani, Gianluca; Varasano, Vincenzo; Petrizzi, Lucio; Amorena, Michele

    2016-05-10

    A rapid LC-MS/MS method for the determination of marbofloxacin in plasma and synovial fluid is presented in this study. The method uses a rapid sample preparation which only requires an ultrafiltration step with centrifugal filter devices. The optimized procedure allows a minimal need of sample (175 μL), particularly useful for synovial fluid samples which amount is rather limited; it is simple, rapid and easily applicable providing anyhow a satisfactory clean up, demonstrated by post-infusion experiments. On the other hand to maximize the speed of the analysis an ultrafast chromatographic separation has been obtained by selecting a column of 20 mm; the reduced run-time is suitable for processing numerous samples on a daily basis. Linearity was assessed in the range 5-2500 ng mL(-1); ofloxacin was used as internal standard. LOD and LOQ were respectively 1 and 5 ng/mL. The method was successfully applied to a set of samples generated during an experimental veterinary study.

  3. Prevention of PVDF ultrafiltration membrane fouling by coating MnO2 nanoparticles with ozonation.

    PubMed

    Yu, Wenzheng; Brown, Matthew; Graham, Nigel J D

    2016-01-01

    Pre-treatment is normally required to reduce or control the fouling of ultrafiltration (UF) membranes in drinking water treatment process. Current pre-treatment methods, such as coagulation, are only partially effective to prevent long-term fouling. Since biological activities are a major contributor to accumulated fouling, the application of an oxidation/disinfection step can be an effective complement to coagulation. In this study, a novel pre-treatment method has been evaluated at laboratory scale consisting of the addition of low dose ozone into the UF membrane tank after coagulation and the use of a hollow-fibre membrane coated with/without MnO2 nanoparticles over a test period of 70 days. The results showed that there was minimal fouling of the MnO2 coated membrane (0.5 kPa for 70 days), while the uncoated membrane experienced both reversible and irreversible fouling. The difference was attributed to the greatly reduced presence of bacteria and organic matter because of the catalytic decomposition of ozone to hydroxyl radicals and increase of the hydrophilicity of the membrane surface. In particular, the MnO2 coated membrane had a much thinner cake layer, with significantly less polysaccharides and proteins, and much less accumulated organic matter within the membrane pores.

  4. Polyethersulfone/polyacrylonitrile blended ultrafiltration membranes: preparation, morphology and filtration properties.

    PubMed

    Pasaoglu, Mehmet Emin; Guclu, Serkan; Koyuncu, Ismail

    2016-01-01

    Polyethersulfone (PES)/polyacrylonitrile (PAN) membranes have been paid attention among membrane research subjects. However, very few studies are included in the literature. In our study, asymmetric ultrafiltration (UF) membranes were prepared from blends of PES/PAN with phase inversion method using water as coagulation bath. Polyvinylpyrrolidone (PVP) with Mw of 10,000 Da was used as pore former agent. N,N-dimethylformamide was used as solvent. The effects of different percentage of PVP and PES/PAN composition on morphology and water filtration properties were investigated. Membrane performances were examined using pure water and lake water filtration studies. Performances of pure water were less with the addition of PAN into the PES polymer casting solutions. However, long-term water filtration tests showed that PES/PAN blend membranes anti-fouling properties were much higher than the neat PES membranes. The contact angles of PES/PAN membranes were lower than neat PES membranes because of PAN addition in PES polymer casting solutions. Furthermore, it was found that PES/PAN blend UF membranes' dynamic mechanical analysis properties in terms of Young's modules were less than neat PES membrane because of decreasing amount of PES polymer. PMID:27508379

  5. Recovery of nickel from aqueous solutions by complexation-ultrafiltration process with sodium polyacrylate and polyethylenimine.

    PubMed

    Shao, Jiahui; Qin, Shu; Davidson, Joshua; Li, Wenxi; He, Yiliang; Zhou, H Susan

    2013-01-15

    The recovery of nickel from aqueous dilute solutions by complexation-ultrafiltration process with sodium polyacrylate (PAAS) and polyethylenimine (PEI) was studied. Experiments were performed as a function of aqueous pH, polymer/Ni(2+) ratio and background electrolyte concentration. At optimum experimental conditions, the nickel removal rate reaches 99.5% using PAAS and 93.0% using PEI as the complexation agent. The nickel removal rate was found to decrease as the adding salt NaCl concentration increases for both complexation agents. A series of experiments implied that the mechanism could be the compressing electric double layer other than the competitive complexation. Diafiltration technique was further performed to regenerate complexation agents and recover nickel. The nickel removal rates were found to be close to those obtained with the original PEI and PAAS. Finally, Langmuir-type binding isotherm equation was employed to evaluate the extent of nickel bound to PAAS and PEI. The overall results from the two-step process of complexation-UF and decomplexation-UF separation showed that it could be a promising method for nickel removal and recovery from aqueous solutions. PMID:23177250

  6. Chemical and cellular antioxidative properties of threadfin bream (Nemipterus spp.) surimi byproduct hydrolysates fractionated by ultrafiltration.

    PubMed

    Wiriyaphan, Chompoonuch; Xiao, Hang; Decker, Eric A; Yongsawatdigul, Jirawat

    2015-01-15

    Protein hydrolysate from frame, bone and skin (FBSH) of threadfin bream was prepared using Virgibacillus sp. SK33 proteinase and fractionated using sequential ultrafiltration membranes with molecular weight cut-offs (MWCO) of 30, 5 and 1 kDa, respectively. Four fractions, namely FBSH-I (>30 kDa), FBSH-II (5-30 kDa), FBSH-III (1-5 kDa), and FBSH-IV (<1 kDa), were obtained. All fractions were rich in Lys, Glu/Gln, Gly, Pro, Ala, Asp/Asn, and Arg. FBSH-III and FBSH-IV showed the highest surface hydrophobicity measured by 8-anilino-1-naphthalenesulfonic acid (ANS) probe (p<0.05). FBSH-III showed the highest antioxidant activity and cytoprotective effects against tert-butyl hydroperoxide (TBHP)-induced cytotoxicity of Caco-2 cells. In addition, FBSH-III inhibited lactate dehydrogenase (LDH) leakage and intracellular reactive species (ROS) production in a dose-dependent manner. FBSH-III retained antioxidant activity and cytoprotective capacity after in vitro simulated gastrointestinal digestion. These results suggested that FBSH-III might potentially be nutraceutical peptides with antioxidative properties. PMID:25148952

  7. A new way to apply ultrasound in cross-flow ultrafiltration: application to colloidal suspensions.

    PubMed

    Hengl, N; Jin, Y; Pignon, F; Baup, S; Mollard, R; Gondrexon, N; Magnin, A; Michot, L; Paineau, E

    2014-05-01

    A new coupling of ultrasound device with membrane process has been developed in order to enhance cross-flow ultrafiltration of colloidal suspensions usually involved in several industrial applications included bio and agro industries, water and sludge treatment. In order to reduce mass transfer resistances induced by fouling and concentration polarization, which both are main limitations in membrane separation process continuous ultrasound is applied with the help of a vibrating blade (20 kHz) located in the feed channel all over the membrane surface (8mm between membrane surface and the blade). Hydrodynamic aspects were also taking into account by the control of the rectangular geometry of the feed channel. Three colloidal suspensions with different kinds of colloidal interaction (attractive, repulsive) were chosen to evaluate the effect of their physico-chemical properties on the filtration. For a 90 W power (20.5 W cm(-2)) and a continuous flow rate, permeation fluxes are increased for each studied colloidal suspension, without damaging the membrane. The results show that the flux increase depends on the initial structural properties of filtered dispersion in terms of colloidal interaction and spatial organizations. For instance, a Montmorillonite Wyoming-Na clay suspension was filtered at 1.5 × 10(5)Pa transmembrane pressure. Its permeation flux is increased by a factor 7.1, from 13.6 L m(-2)h(-1) without ultrasound to 97 L m(-2)h(-1) with ultrasound.

  8. Antioxidant activities of bambara groundnut (Vigna subterranea) protein hydrolysates and their membrane ultrafiltration fractions.

    PubMed

    Arise, Abimbola K; Alashi, Adeola M; Nwachukwu, Ifeanyi D; Ijabadeniyi, Oluwatosin A; Aluko, Rotimi E; Amonsou, Eric O

    2016-05-18

    In this study, the bambara protein isolate (BPI) was digested with three proteases (alcalase, trypsin and pepsin), to produce bambara protein hydrolysates (BPHs). These hydrolysates were passed through ultrafiltration membranes to obtain peptide fractions of different sizes (<1, 1-3, 3-5 and 5-10 kDa). The hydrolysates and their peptide fractions were investigated for antioxidant activities. The membrane fractions showed that peptides with sizes <3 kDa had significantly (p < 0.05) reduced surface hydrophobicity when compared with peptides >3 kDa. This is in agreement with the result obtained for the ferric reducing power, metal chelating and hydroxyl radical scavenging activities where higher molecular weight peptides exhibited better activity (p < 0.05) when compared to low molecular weight peptide fractions. However, for all the hydrolysates, the low molecular weight peptides were more effective diphenyl-1-picrylhydrazyl (DPPH) radical scavengers but not superoxide radicals when compared to the bigger peptides. In comparison with glutathione (GSH), BPHs and their membrane fractions had better (p < 0.05) reducing power and ability to chelate metal ions except for the pepsin hydrolysate and its membrane fractions that did not show any metal chelating activity. However, the 5-10 kDa pepsin hydrolysate peptide fractions had greater (88%) hydroxyl scavenging activity than GSH, alcalase and trypsin hydrolysates (82%). These findings show the potential use of BPHs and their peptide fraction as antioxidants in reducing food spoilage or management of oxidative stress-related metabolic disorders. PMID:27156453

  9. Using Zero Balance Ultrafiltration with Dialysate as a Replacement Fluid for Hyperkalemia during Cardiopulmonary Bypass

    PubMed Central

    Heath, Michele; Raghunathan, Karthik; Welsby, Ian; Maxwell, Cory

    2014-01-01

    Abstract: Avoiding or managing hyperkalemia during cardiac surgery, especially in a patient with chronic renal insufficiency, can be challenging. Hyperkalemic cardioplegia solution is usually administered to achieve and maintain an electrical arrest of the heart. This solution eventually mixes in with the systemic circulation, contributing to elevated systemic potassium levels. Administration of packed red blood cells, hemolysis, tissue damage, and acidosis are also common causes of hyperkalemia. Current strategies to avoid or manage hyperkalemia include minimizing the volume of cardioplegia administered, shifting potassium from the extracellular into the intracellular space (by the administration of sodium bicarbonate when the pH is low and/or dextrose–insulin when effects relatively independent of serum pH are desired), using zero-balanced ultrafiltration (Z-BUF) with normal saline as the replacement fluid (to remove potassium from the body rather than simply shift the electrolyte across cellular membranes), and, occasionally, hemodialysis (1). We report the application of Z-BUF using an electrolyte-balanced, low potassium dialysate solution rather than isotonic saline to avoid a high chloride load and the potential for hyperchloremic acidosis to successfully treat hyperkalemia while on cardiopulmonary bypass. PMID:26357794

  10. Biofilm increases permeate quality by organic carbon degradation in low pressure ultrafiltration.

    PubMed

    Chomiak, A; Traber, J; Morgenroth, E; Derlon, N

    2015-11-15

    We investigated the influence of biofouling of ultrafiltration membranes on the removal of organic model foulants and ultimately on the quality of permeate. Gravity Driven Membrane ultrafiltration (GDM) membrane systems were operated with modified river water during five weeks without control of the biofilm formation. Three GDM systems were studied: two systems with biofilms exposed to (A) variable or (B) constant load of organic foulants, and (C) one system operated without biofilm and exposed to constant foulant loading. Biodegradable dextran or non-biodegradable polystyrene sulfonate model foulants were tested. Substrate biodegradability was confirmed by Size Exclusion Chromatography (SEC) and by degradation batch tests (D). The GDM systems (A) and (B) were fed with pre-filtered river water supplemented with dextran (Dex) of 1, 150 or 2000 kDa, or polystyrene sulfonate (PSS) of 1 or 80 kDa at concentrations of 2-3.5 mgC L(-1). In exp. (C) the feed water consisted of deionized water with 25 mgC L(-1) of either PSS 1, 80 kDa or Dex 2000 kDa. The biofilm formation on UF membrane surfaces controlled the foulant permeation and thus the permeate quality. Biofilms exposed to continuous foulant loading (exp. B) degraded low molecular weight (LMW) biodegradable foulants (1 kDa Dex), which improved the permeate quality. For high molecular weight (HMW) substrates (150, 2000 kDa Dex), the improvement of the permeate quality was observed after 7 days of biofilm formation, and resulted from the foulant hydrolysis followed by degradation. For non-biodegradable foulants, an improvement of 20% of the retention was observed for the polystyrene (1, 80 kDa PSS) due to the presence of biofilms on membrane surfaces. For variable foulant loading (exp. A) the biofilms hydrolysed the large biodegradable foulants but did not degraded them fully, which resulted a deterioration of the permeate quality (except for the LMW dextran (1 kDa) that was fully degraded). Overall, the "biofilm

  11. Biofilm increases permeate quality by organic carbon degradation in low pressure ultrafiltration.

    PubMed

    Chomiak, A; Traber, J; Morgenroth, E; Derlon, N

    2015-11-15

    We investigated the influence of biofouling of ultrafiltration membranes on the removal of organic model foulants and ultimately on the quality of permeate. Gravity Driven Membrane ultrafiltration (GDM) membrane systems were operated with modified river water during five weeks without control of the biofilm formation. Three GDM systems were studied: two systems with biofilms exposed to (A) variable or (B) constant load of organic foulants, and (C) one system operated without biofilm and exposed to constant foulant loading. Biodegradable dextran or non-biodegradable polystyrene sulfonate model foulants were tested. Substrate biodegradability was confirmed by Size Exclusion Chromatography (SEC) and by degradation batch tests (D). The GDM systems (A) and (B) were fed with pre-filtered river water supplemented with dextran (Dex) of 1, 150 or 2000 kDa, or polystyrene sulfonate (PSS) of 1 or 80 kDa at concentrations of 2-3.5 mgC L(-1). In exp. (C) the feed water consisted of deionized water with 25 mgC L(-1) of either PSS 1, 80 kDa or Dex 2000 kDa. The biofilm formation on UF membrane surfaces controlled the foulant permeation and thus the permeate quality. Biofilms exposed to continuous foulant loading (exp. B) degraded low molecular weight (LMW) biodegradable foulants (1 kDa Dex), which improved the permeate quality. For high molecular weight (HMW) substrates (150, 2000 kDa Dex), the improvement of the permeate quality was observed after 7 days of biofilm formation, and resulted from the foulant hydrolysis followed by degradation. For non-biodegradable foulants, an improvement of 20% of the retention was observed for the polystyrene (1, 80 kDa PSS) due to the presence of biofilms on membrane surfaces. For variable foulant loading (exp. A) the biofilms hydrolysed the large biodegradable foulants but did not degraded them fully, which resulted a deterioration of the permeate quality (except for the LMW dextran (1 kDa) that was fully degraded). Overall, the "biofilm

  12. Ultrafiltration in patients with decompensated heart failure and diuretic resistance: an Asian centre’s experience

    PubMed Central

    Teo, Loon Yee Louis; Lim, Choon Pin; Neo, Chia Lee; Teo, Lee Wah; Ng, Swee Ling Elaine; Chan, Laura Lihua; Kaushik, Manish; Sim, Kheng Leng David

    2016-01-01

    INTRODUCTION Diuretics are the mainstay of therapy for restoring the euvolaemic state in patients with decompensated heart failure. However, diuretic resistance remains a challenge. METHODS We conducted a retrospective cohort study to examine the efficacy and safety of ultrafiltration (UF) in 44 hospitalised patients who had decompensated heart failure and diuretic resistance between October 2011 and July 2013. RESULTS Among the 44 patients, 18 received UF (i.e. UF group), while 26 received diuretics (i.e. standard care group). After 48 hours, the UF group achieved lower urine output (1,355 mL vs. 3,815 mL, p = 0.0003), greater fluid loss (5,058 mL vs. 1,915 mL, p < 0.0001) and greater weight loss (5.0 kg vs. 1.0 kg, p < 0.0001) than the standard care group. The UF group also had a shorter duration of hospitalisation (5.0 days vs. 9.5 days, p = 0.0010). There were no differences in the incidence of 30-day emergency department visits and rehospitalisations for heart failure between the two groups. At 90 days, the UF group had fewer emergency department visits (0.2 vs. 0.8, p = 0.0500) and fewer rehospitalisations for heart failure (0.3 vs. 1.0, p = 0.0442). Reduction in EQ-5D™ scores was greater in the UF group, both at discharge (2.7 vs. 1.4, p = 0.0283) and 30 days (2.5 vs. 0.3, p = 0.0033). No adverse events were reported with UF. CONCLUSION UF is an effective and safe treatment that can improve the health outcomes of Asian patients with decompensated heart failure and diuretic resistance. PMID:26778634

  13. The composition and compression of biofilms developed on ultrafiltration membranes determine hydraulic biofilm resistance.

    PubMed

    Derlon, Nicolas; Grütter, Alexander; Brandenberger, Fabienne; Sutter, Anja; Kuhlicke, Ute; Neu, Thomas R; Morgenroth, Eberhard

    2016-10-01

    This study aimed at identifying how to improve the level of permeate flux stabilisation during gravity-driven membrane filtration without control of biofilm formation. The focus was therefore on understanding (i) how the different fractions of the biofilms (inorganics particles, bacterial cells, EPS matrix) influence its hydraulic resistance and (ii) how the compression of biofilms impacts its hydraulic resistance, i.e., can water head be increased to increase the level of permeate flux stabilisation. Biofilms were developed on ultrafiltration membranes at 88 and 284 cm water heads with dead-end filtration for around 50 days. A larger water head resulted in a smaller biofilm permeability (150 and 50 L m(-2) h(-1) bar(-1) for biofilms grown at 88 cm and 284 cm water head, respectively). Biofilms were mainly composed of EPS (>90% in volume). The comparison of the hydraulic resistances of biofilms to model fouling layers indicated that most of the hydraulic resistance is due to the EPS matrix. The compressibility of the biofilm was also evaluated by subjecting the biofilms to short-term (few minutes) and long-term variations of transmembrane pressures (TMP). A sudden change of TMP resulted in an instantaneous and reversible change of biofilm hydraulic resistance. A long-term change of TMP induced a slow change in the biofilm hydraulic resistance. Our results demonstrate that the response of biofilms to a TMP change has two components: an immediate variation of resistance (due to compression/relaxation) and a long-term response (linked to biofilm adaptation/growth). Our results provide relevant information about the relationship between the operating conditions in terms of TMP, the biofilm structure and composition and the resulting biofilm hydraulic resistance. These findings have practical implications for a broad range of membrane systems.

  14. Intermittent operation of ultra-low pressure ultrafiltration for decentralized drinking water treatment.

    PubMed

    Peter-Varbanets, Maryna; Gujer, Willi; Pronk, Wouter

    2012-06-15

    River water was treated by ultrafiltration at a relatively low transmembrane pressure (40 mbar). As observed before, flux stabilization occurred after several days of operation although no back-flushing or cross flow was applied. Interruptions in flux were applied by temporary offset of the transmembrane pressure. After restoration of the transmembrane pressure, the initial flux was higher than the stable flux level, and the flux recovery depended on the standstill time. Furthermore, if a short cross flow was applied after standstill, the flux was restored to an even higher level. In all cases, the flux decreased again during operation to reach finally the same stable level as before standstill. In order to evaluate the influence of intermittent operation as practiced for water treatment on a household level, daily interruptions of flux were applied. An optimum of total daily water production rate was obtained at 21 h of operation and 3 h of standstill per day. A model was developed which can describe the impact of intermittent operation on the flux depending on the duration of the standstill and operating periods. This enables the prediction of production capacity of the system operated intermittently. The flux increase during standstill could be explained by a relaxation and expansion of the biofouling layer, while the higher flux after forward-flushing was caused by this layer being partially sloughed off. Household water treatment with the process presented here will generally be operated on a discontinuous basis. The results show that such operation schemes do not compromise the permeability of the system, but actually lead to higher fluxes after standstill. PMID:22497767

  15. Ultrafiltration of wastewater: effects of particles, mode of operation, and backwash effectiveness.

    PubMed

    Bourgeous, K N; Darby, J L; Tchobanoglous, G

    2001-01-01

    The effects that wastewater quality and mode of operation have on the performance of an asymmetric, hollow fiber, polysulfone, ultrafiltration (UF) membrane with a molecular weight cutoff of 100,000 Daltons were investigated. Performance was assessed through monitoring membrane flux, transmembrane pressure, effluent biochemical oxygen demand, and operational cost of the experimental system while treating filtered secondary, secondary, and filtered primary effluents. Fluxes achieved for filtered secondary (129-173 l/m2 h), secondary (101-158 l/m2 h), and filtered primary (20-41 l/m2 h) effluents were compared to those obtained at three other locations where similar UF systems were operated. A conceptual model of the impact of an insufficient backwash and of operating the UF system at constant flux on membrane performance is presented to explain the differences in fluxes. Employing pre-membrane granular filtration to remove a portion of the problematic particles in secondary effluent prior to UF led to optimal operational conditions. The costs associated with the operation of pre-membrane granular filtration were offset by the increase in production achieved. Although the use of recirculation could increase maintainable flux when treating a concentrated feed (e.g., filtered primary effluent), the associated costs were high. Improved UF performance was found to result from allowing flux to decline naturally, rather than using a constant flux mode of operation. The effluents produced when filtered secondary and secondary effluents were the feeds would be equivalent to an oxidized, coagulated, clarified, and filtered wastewater as per Title 22 California Wastewater Reclamation Criteria. PMID:11257896

  16. Theoretical analysis of excipient concentrations during the final ultrafiltration/diafiltration step of therapeutic antibody.

    PubMed

    Miao, Fudu; Velayudhan, Ajoy; DiBella, Elsie; Shervin, Jaclyn; Felo, Michael; Teeters, Mark; Alred, Patricia

    2009-01-01

    Diafiltration of a protein solution into a new buffer is a common final step in biopharmaceutical manufacturing. However, the excipient concentrations in the retentate are not always equal to their corresponding concentrations in the new buffer (diafiltration buffer). This phenomenon was observed repeatedly during diafiltration of different therapeutic monoclonal antibodies in which the concentrations of histidine and either sorbitol or sucrose (depending on which was chosen for the diafiltration buffer) in the retentate were lower than in the diafiltration buffer. Experimental studies and theoretical analyses of the ultrafiltration/diafiltration (UF/DF) step were carried out to determine the primary causes of the phenomenon and to develop a mathematical model capable of predicting retentate excipient concentrations. The analyses showed that retentate histidine concentration was low primarily because of repulsive charge interactions between positively-charged histidine molecules and positively-charged protein molecules, and that volume exclusion effects were secondary for like-charged molecules. The positively-charged protein molecules generate an electrical potential that cause an uneven distribution of charged histidine molecules. This interaction was used to construct a mathematical model based on the Poisson-Boltzmann equation. The model successfully predicted the final histidine concentration in the diafiltered product (retentate) from the UF/DF development and production runs, with good agreement across a wide range of protein and histidine concentrations for four therapeutic monoclonal antibodies. The concentrations of uncharged excipients (sorbitol or sucrose) were also successfully predicted using previously established models, with volume exclusion identified as the primary cause of differences in uncharged excipient concentrations in the retentate and diafiltration buffer.

  17. Applying polarity rapid assessment method and ultrafiltration to characterize NDMA precursors in wastewater effluents.

    PubMed

    Chen, Chao; Leavey, Shannon; Krasner, Stuart W; Mel Suffet, I H

    2014-06-15

    Certain nitrosamines in water are disinfection byproducts that are probable human carcinogens. Nitrosamines have diverse and complex precursors that include effluent organic matter, some anthropogenic chemicals, and natural (likely non-humic) substances. An easy and selective tool was first developed to characterize nitrosamine precursors in treated wastewaters, including different process effluents. This tool takes advantages of the polarity rapid assessment method (PRAM) and ultrafiltration (UF) (molecular weight distribution) to locate the fractions with the strongest contributions to the nitrosamine precursor pool in the effluent organic matter. Strong cation exchange (SCX) and C18 solid-phase extraction cartridges were used for their high selectivity for nitrosamine precursors. The details of PRAM operation, such as cartridge clean-up, capacity, pH influence, and quality control were included in this paper, as well as the main parameters of UF operation. Preliminary testing of the PRAM/UF method with effluents from one wastewater treatment plant gave very informative results. SCX retained 45-90% of the N-nitrosodimethylamine (NDMA) formation potential (FP)-a measure of the precursors-in secondary and tertiary wastewater effluents. These results are consistent with NDMA precursors likely having a positively charged amine group. C18 adsorbed 30-45% of the NDMAFP, which indicates that a substantial portion of these precursors were non-polar. The small molecular weight (MW) (<1 kDa) and large MW (>10 kDa) fractions obtained from UF were the primary contributors to NDMAFP. The combination of PRAM and UF brings important information on the characteristics of nitrosamine precursors in water with easy operation.

  18. Effects of sodium hypochlorite exposure mode on PES/PVP ultrafiltration membrane degradation.

    PubMed

    Causserand, Christel; Pellegrin, Bastien; Rouch, Jean-Christophe

    2015-11-15

    Drinking water production plants using membrane filtration processes report membrane failure issues. According to the literature, membrane degradation is often induced by exposure to sodium hypochlorite, an oxidant widely used during in-place cleanings. The present study focused on quantifying the effect of membrane exposure mode to hypochlorite on properties modifications of a PES/PVP ultrafiltration membrane widely used for drinking water production. For this purpose effects of sodium hypochlorite concentration, contact duration and exposure mode (static or dynamic) were investigated. The pH of the hypochlorite solution was set to 8 as it was demonstrated in numerous previous works that the pH range 7-8 leads to the most severe modification in the membrane characteristics. Membrane degradation was monitored at molecular scale by attenuated total reflectance infrared spectroscopy and at macroscopic scale by pure water permeability and elongation at break measurements. The results obtained in static (soaking) and dynamic (filtration and filtration/backwashing cycles) hypochlorite exposure modes indicated that PES/PVP membrane degradation progress was predominantly governed by hypochlorite oxidation rate. In the tested conditions, mechanical stress (pressure differentials) did not significantly contribute to membrane ageing. The correlation between molecular and macroscopic characterizations demonstrated that PVP degradation is responsible for the membrane integrity loss. A linear relationship between the loss of ductility of the membrane and the progress of the PVP degradation was obtained whatever the exposure mode. Thanks to experiments conducted at various hypochlorite concentrations and exposure durations, the hypochlorite dose parameter (hypochlorite concentration times contact time), widely used in the literature, was demonstrated to be inappropriate to describe the degradation rate: the hypochlorite concentration impact was shown to be dominating the

  19. Optimisation of sample treatment for arsenic speciation in alga samples by focussed sonication and ultrafiltration.

    PubMed

    Salgado, S García; Quijano Nieto, M A; Bonilla Simón, M M

    2006-02-28

    A procedure for arsenic species fractionation in alga samples (Sargassum fulvellum, Chlorella vulgaris, Hizikia fusiformis and Laminaria digitata) by extraction is described. Several parameters were tested in order to evaluate the extraction efficiency of the process: extraction medium, nature and concentration (tris(hydroxymethyl)aminomethane, phosphoric acid, deionised water and water/methanol mixtures), extraction time and physical treatment (magnetic stirring, ultrasonic bath and ultrasonic focussed probe). The extraction yield of arsenic under the different conditions was evaluated by determining the total arsenic content in the extracts by ICP-AES. Arsenic compounds were extracted in 5mL of water by focussed sonication for 30s and subsequent centrifugation at 14,000xg for 10min. The process was repeated three times. Extraction studies show that soluble arsenic compounds account for about 65% of total arsenic. An ultrafiltration process was used as a clean-up method for chromatographic analysis, and also allowed us to determine the extracted arsenic fraction with a molecular weight lower than 10kDa, which accounts for about 100% for all samples analysed. Speciation studies were carried out by HPLC-ICP-AES. Arsenic species were separated on a Hamilton PRP-X100 column with 17mM phosphate buffer at pH 5.5 and 1.0mLmin(-1) flow rate. The chromatographic method allowed us to separate the species As(III), As(V), MMA and DMA in less than 13min, with detection limits of about 20ng of arsenic per species, for a sample injection volume of 100muL. The chromatographic analysis allowed us to identify As(V) in Hizikia (46+/-2mugg(-1)), Sargassum (38+/-2mugg(-1)) and Chlorella (9+/-1mugg(-1)) samples. The species DMA was also found in Chlorella alga (13+/-1mugg(-1)). However, in Laminaria alga only an unknown arsenic species was detected, which eluted in the dead volume.

  20. Hollow-fiber ultrafiltration for simultaneous recovery of viruses, bacteria and parasites from reclaimed water.

    PubMed

    Liu, Pengbo; Hill, Vincent R; Hahn, Donghyun; Johnson, Trisha B; Pan, Yi; Jothikumar, Narayanan; Moe, Christine L

    2012-01-01

    Hollow-fiber ultrafiltration (UF) is a technique that has been reported to be effective for recovering a diverse array of microbes from water, and may also be potentially useful for microbial monitoring of effluent from water reclamation facilities. However, few data are available to indicate the potential limitations and efficacy of the UF technique for treated wastewater. In this study, recovery efficiencies were determined for various options available for performing the tangential-flow UF technique, including hollow-fiber ultrafilter (i.e., dialyzer) type, ultrafilter pre-treatment (i.e., blocking), and elution. MS2 and ΦX174 bacteriophages, Clostridium perfringens spores, Escherichia coli, and Cryptosporidium parvum oocysts were seeded into 10-L reclaimed water samples to evaluate UF options. Then a single UF protocol was established and studied using seeded and non-seeded 100-L samples from two water reclamation facilities in Georgia, USA. Baxter Exeltra Plus 210 and Fresenius F200NR dialyzers were found to provide significantly higher microbial recovery than Minntech HPH 1400 hemoconcentrators. The selected final UF method incorporated use of a non-blocked ultrafilter for UF followed by elution using a surfactant-based solution. For 10-L samples, this method achieved recovery efficiencies of greater than 50% recovery of seeded viruses, bacteria, and parasites. There was no significant difference in overall microbial recovery efficiency when the method was applied to 10- and 100-L samples. In addition, detection levels for pathogens in seeded 100-L reclaimed water samples were 1000 PFU HAV, 10,000 GI norovirus particles, <500 Salmonella and <200 Cryptosporidium oocysts. These data demonstrate that UF can be an effective technique for recovering diverse microbes in reclaimed water to monitor and improve effluent water quality in wastewater treatment plants.

  1. Ultrafiltration improves ELISA and Endopep MS analysis of botulinum neurotoxin type A in drinking water.

    PubMed

    Raphael, Brian H; Lautenschlager, Matthew; Kahler, Amy; Pai, Suresh; Parks, Bryan A; Kalb, Suzanne R; Maslanka, Susan E; Shah, Sanjiv; Magnuson, Matthew; Hill, Vincent R

    2012-09-01

    The objective of this study was to adapt and evaluate two in vitro botulinum neurotoxin (BoNT) detection methods, including the Botulinum Toxin ELISA and the Endopep MS (a mass spectrometric-based endopeptidase method), for use with drinking water samples. The method detection limits (MDL) of the ELISA and Endopep MS were 260 pg/mL and 21 pg/mL of BoNT/A complex toxin, respectively. Since toxin could be present in water samples at highly dilute concentrations, large volume (100-L) samples of municipal tap water from five US municipalities having distinct water compositions were dechlorinated, spiked with 5 μg BoNT/A, and subjected to tangential-flow ultrafiltration (UF) using hollow fiber dialyzers. The recovery efficiency of BoNT/A using UF and quantified by ELISA ranged from 11% to 36% while efficiencies quantified by MS ranged from 26% to 55%. BoNT/A was shown to be stable in dechlorinated municipal tap water stored at 4°C for up to four weeks. In addition, toxin present in UF-concentrated water samples was also shown to be stable at 4°C for up to four weeks, allowing holding of samples prior to analysis. Finally, UF was used to concentrate a level of toxin (7 pg/mL) which is below the MDL for direct analysis by both ELISA and Endopep MS. Following UF, toxin was detectable in these samples using both in vitro analysis methods. These data demonstrate that UF-concentration of toxin from large volume water samples followed by use of existing analytical methods for detection of BoNT/A can be used in support of a monitoring program for contaminants in drinking water.

  2. Intermittent operation of ultra-low pressure ultrafiltration for decentralized drinking water treatment.

    PubMed

    Peter-Varbanets, Maryna; Gujer, Willi; Pronk, Wouter

    2012-06-15

    River water was treated by ultrafiltration at a relatively low transmembrane pressure (40 mbar). As observed before, flux stabilization occurred after several days of operation although no back-flushing or cross flow was applied. Interruptions in flux were applied by temporary offset of the transmembrane pressure. After restoration of the transmembrane pressure, the initial flux was higher than the stable flux level, and the flux recovery depended on the standstill time. Furthermore, if a short cross flow was applied after standstill, the flux was restored to an even higher level. In all cases, the flux decreased again during operation to reach finally the same stable level as before standstill. In order to evaluate the influence of intermittent operation as practiced for water treatment on a household level, daily interruptions of flux were applied. An optimum of total daily water production rate was obtained at 21 h of operation and 3 h of standstill per day. A model was developed which can describe the impact of intermittent operation on the flux depending on the duration of the standstill and operating periods. This enables the prediction of production capacity of the system operated intermittently. The flux increase during standstill could be explained by a relaxation and expansion of the biofouling layer, while the higher flux after forward-flushing was caused by this layer being partially sloughed off. Household water treatment with the process presented here will generally be operated on a discontinuous basis. The results show that such operation schemes do not compromise the permeability of the system, but actually lead to higher fluxes after standstill.

  3. Clearance of extractables and leachables from single-use technologies via ultrafiltration/diafiltration operations.

    PubMed

    Magarian, Nicholas; Lee, Kate; Nagpal, Kunal; Skidmore, Ken; Mahajan, Ekta

    2016-05-01

    Quantifying the clearance of extractables and leachables (E/L) throughout ultrafiltration/diafiltration (UFDF) operations allows for greater flexibility in the implementation of single-use technologies in steps upstream of the UFDF process. A proof-of-concept study was completed in which the clearance of 7 E/L from single-use technologies (trimethylsilanol, hexanoic acid, butyrolactone, t-butyl alcohol, caprolactam, acetonitrile, and benzyl alcohol) in four representative proteins were measured and monitored during the UFDF process using quantitative NMR. This study demonstrated that the defined E/L spiked into a variety of protein solutions can be cleared to <1 ppm by 9 diavolumes from a maximum initial load concentration of 1,000 ppm. However, in some cases a rebound effect was observed in the recovered pool to >1 ppm, which is explained in detail. The overall clearance trend observed for both buffer control and protein-containing solutions resembled the ideal clearance trend where no apparent interactions were observed between E/L with the protein, UFDF system, or with other defined E/L which may be present in the system. Additionally, the UFDF system is capable of clearing these potential E/L from single-use technologies below 1 ppm irrespective of initial concentrations in the load (1,000 or 100 ppm), independently from the type of protein. In general, mass recoveries were within ±15% of each spiked compound in protein solutions and their respective buffer controls, suggesting spiked E/L do not interact strongly with protein. By demonstrating the product independent clearance trends of the spiked E/L across UFDF, these results will contribute to the simplification of the E/L toxicology assessment and allow modular manufacturing approach for single-use technologies in biopharmaceutical manufacturing. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:718-724, 2016. PMID:27071939

  4. Towards field trace metal speciation using electroanalytical techniques and tangential ultrafiltration.

    PubMed

    Monteiro, Adnívia Santos Costa; Parat, Corinne; Rosa, André Henrique; Pinheiro, José Paulo

    2016-05-15

    In this work we propose a trace metal speciation methodology to determine the total, free and ultrafiltered (<1 KDa) metal fractions using electrochemical methods (SCP and AGNES) and tangential ultrafiltration (UF) experiments that can easily be carried out on-site. We tested our methodology spiking Cadmium ions into two natural waters samples from Itapanhau and Sorocabinha rivers in Sao Paulo State, Brazil. The limits of detection (LOD) was 1.6×10(-9) M for the total Cd(2+) determination performed by Stripping Chronopotentiometry (SCP) in the source and acidified ultrafiltered solution and 1.9×10(-9) M for the free Cd(2+) determination using Absence of gradients and Nernstian equilibrium stripping (AGNES), using a thin mercury film electrode. The total metal determination was performed by SCP in acidified samples and the results compared with graphite furnace atomic absorption spectroscopy (GF-AAS). The SCP results were adequate with a 96% of recovery from the known metal spike for the 12 samples tested. For the Itapanhau sample the free metal determined by AGNES and the ultrafiltered fraction are identical, while for the Sorocabinha the free metal in the source is significantly smaller than the ultrafiltered fraction, indicating that this sample must be rich in metal complexes with small inorganic ligands that are able to permeate the 1kDa membrane. The proposed metal speciation methodology validated in the laboratory combining UF and SCP/AGNES is able to be used in on-site experiments providing valid information regarding the total and free metal concentrations and additionally some insight on the role of small inorganic ligands to the metal complexation.

  5. Effect of ultrafiltration of yeast extracts on their ability to promote lactic acid bacteria growth.

    PubMed

    Gaudreau, H; Champagne, C P; Conway, J; Degré, R

    1999-11-01

    Five yeast extracts (YE) were fractionated by ultrafiltration (UF) with 1, 3, and 10 kDa molecular weight cutoff membranes, concentrated by freeze-drying, and the resulting powders of yeast extract filtrates (YEF) were evaluated for their growth-promoting properties on nine cultures of lactic acid bacteria (LAB). There was an increase in alpha-amino nitrogen content of the YEF powders as the pore size of the UF membranes used to filter the YE solutions decreased. The source of YE had a much greater effect than UF on the growth of LAB. This was also the case for the YEF contents in total and alpha-amino nitrogen. Growth curves of the LAB showed that maximum growth rate (mumax) data were on average 30% higher with bakers' YE than with brewers' YE, while maximum optical density (ODmax) values were on average 16% higher with bakers' YE. This could be related to the higher nitrogen content of the bakers' YE used in this study. Modification by UF of the YE had no significant influence on the growth of 4 of the 9 LAB strains. The three strains of Lactobacillus casei were negatively influenced by UF, as they did not grow as well in the media containing the YEF obtained after filtering with 1 and 3 kDa membranes. On a total solids basis, the 2.5 x retentates from the 10 kDa membrane gave, on average, 4% lower mumax and 5% lower ODmax values as compared to cultures where the corresponding YEF was used as medium supplement. This could also be partially related to the different nitrogen contents of the filtrates and retentates.

  6. Vascular refilling is independent of volume overload in hemodialysis with moderate ultrafiltration requirements.

    PubMed

    Kron, Susanne; Schneditz, Daniel; Leimbach, Til; Aign, Sabine; Kron, Joachim

    2016-07-01

    Introduction Blood volume changes and vascular refilling during hemodialysis (HD) and ultrafiltration (UF) have been assumed to depend on volume overload (Vo ). It was the aim to study the magnitude of vascular refilling in stable HD patients with moderate volume expansion in everyday dialysis using novel technical approaches. Methods Patients were studied during routine dialysis and UF based on clinical dry weight assessment. Pre-dialysis Vo was independently measured by bioimpedance spectroscopy. Vascular refilling volume (Vref ) was calculated as: Vref  = Vuf  - ΔV, where ΔV is the absolute blood volume change determined by on-line dialysate dilution using a commercial on-line hemodiafiltration machine incorporating a relative blood volume monitor, and where Vuf is the prescribed UF volume. Findings Thirty patients (dry weight: 81.0 ± 17.8 kg) were studied. Pre-dialysis Vo was 2.46 ± 1.45 L. Vuf was 2.27 ± 0.71 L, specific UF rate was 6.45 ± 2.43 mL/kg/h, and since ΔV was 0.66 ± 0.31 L, Vref was determined as 1.61 ± 0.58 L, corresponding to a constant refilling fraction (Fref ) of 70.6 ± 10.6%. Vref strongly correlated with Vuf (r(2)  = 0.82) but was independent of Vo and other volumes. Fref was also independent of Vo and other volumes normalized for various measures of body size. Discussion While vascular refilling and Fref is independent of Vo in treatments with moderate UF requirements, intravascular volume depletion increases with increasing UF requirements. The relationship between blood volume and Vo needs to be more closely examined in further studies to optimize volume control in everyday dialysis.

  7. Characterization and comparative performance of lentiviral vector preparations concentrated by either one-step ultrafiltration or ultracentrifugation.

    PubMed

    Papanikolaou, Eleni; Kontostathi, Georgia; Drakopoulou, Ekati; Georgomanoli, Maria; Stamateris, Evangelos; Vougas, Kostas; Vlahou, Antonia; Maloy, Andrew; Ware, Mark; Anagnou, Nicholas P

    2013-07-01

    Gene therapy utilizing lentiviral vectors (LVs) constitutes a real therapeutic alternative for many inherited monogenic diseases. Therefore, the generation of functional vectors using fast, non-laborious and cost-effective strategies is imperative. Among the available concentration methods for VSV-G pseudotyped lentiviruses to achieve high therapeutic titers, ultracentrifugation represents the most common approach. However, the procedure requires special handling and access to special instrumentation, it is time-consuming, and most importantly, it is cost-ineffective due to the high maintenance expenses and consumables of the ultracentrifuge apparatus. Here we describe an improved protocol in which vector stocks are prepared by transient transfection using standard cell culture media and are then concentrated by ultrafiltration, resulting in functional vector titers of up to 6×10(9) transducing units per millilitre (TU/ml) without the involvement of any purification step. Although ultrafiltration per se for concentrating viruses is not a new procedure, our work displays one major novelty; we characterized the nature and the constituents of the viral batches produced by ultrafiltration using peptide mass fingerprint analysis. We also determined the viral functional titer by employing flow cytometry and evaluated the actual viral particle size and concentration in real time by using laser-based nanoparticle tracking analysis based on Brownian motion. Vectors generated by this production method are contained in intact virions and when tested to transduce in vitro either murine total bone marrow or human CD34(+) hematopoietic stem cells, resulted in equal transduction efficiency and reduced toxicity, compared to lentiviral vectors produced using standard ultracentrifugation-based methods. The data from this study can eventually lead to the improvement of protocols and technical modifications for the clinical trials for gene therapy.

  8. Ozonation and ultrafiltration for the treatment of olive mill wastewaters: effect of key operating conditions and integration schemes.

    PubMed

    Martins, Rui C; Ferreira, Ana M; Gando-Ferreira, Licínio M; Quinta-Ferreira, Rosa M

    2015-10-01

    With the objective of reaching suitable techniques for olive mill wastewater treatment, ozonation and ultrafiltration were studied individually and combined. A continuous reactor was run for the treatment of a phenolic mixture mimicking an actual olive mill wastewater (OMW) by ozonation. The effect of the main operating parameters was analysed (pH, liquid flow rate and ozone inlet concentration). The increase of pH and ozone dose improved ozonation efficiency. As expected, the highest residence time led to higher steady-state degradation (35 % of chemical oxygen demand (COD) abatement). Even if the rise on ozone inlet gas concentration was able to remove COD in a higher extent, it should be taken into consideration that with the lowest oxidant load (15 g O3/m(3)), the maximum steady-state biochemical oxygen demand (BOD5)/COD ratio was reached which would reduce the process costs. These operating conditions (pH 9, 1 mL/min of liquid flow rate and 15 g O3/m(3)) were applied to an actual OMW leading to 80 % of phenolic content abatement and 12 % of COD removal at the steady state. Regarding ultrafiltration, it was concluded that the best total phenolic content (TPh) and COD abatement results (55 and 15 %) are attained for pH 9 and using a transmembrane pressure drop of 1 bar. Among the integration schemes that were tested, ultrafiltration followed by ozonation was able to reach 93 and 20 % of TPh and COD depletion, respectively. Moreover, this sequence led to an effluent with a BOD5/COD ratio of about 0.55 which means that it likely can be posteriorly refined in a municipal wastewater treatment plant. PMID:26013744

  9. ETV REPORT - PHYSICAL REMOVAL OF CRYPTOSPORIDIUM OOCYSTS AND GIARDIA CYSTS IN DRINKING WATER, LEOPOLD MEMBRANE SYSTEMS ULTRABAR ULTRAFILTRATION SYSTEM WITH 60 INCH MARK III ELEMENT AT PITTSBURG, PA - NSF/00/10/EPADW395

    EPA Science Inventory

    Verification testing of the Leopold Ultrabar Mark III Ultrafiltration Systems was conducted from February 3-March9, 1999. The performance claim evaluated during field testing of the Leopold Ultrabar Mark III Ultrafiltration system was that the system is capable of a minimum 3 log...

  10. The role of exopolysaccharides in fouling phenomenon during ultrafiltration of microalgae (Chlorellasp. and Porphyridium purpureum): advantage of a swirling decaying flow.

    PubMed

    Morineau-Thomas, O; Jaouen, P; Legentilhomme, P

    2002-04-01

    Ultrafiltration of two microalgae species, Chorellasp. and Porphyridium purpureum, has been performed in two filtration units of different configurations: a module generating a classical tangential-plane flow and another one inducing a swirling decaying flow. The swirling motion is generated by a unique tangential inlet at the bottom of an annulus. Permeation flux obtained in each ultrafiltration unit depends on the filtered species, and specific deposits are associated to each species and module. Enhancement in permeation flux in the swirling configuration compared with that obtained in the plane unit can reach 40% during the ultrafiltration of Porphyridium purpureum and is negligible for the suspensions of Chlorella sp. The experimental data revealed the significant role of the soluble compounds in the medium culture in terms of flux limitation. It seems that the soluble products and their interactions with the microalgal cells are strongly involved in the fouling mechanism.

  11. Inhibition of glyceraldehyde 3-phosphate dehydrogenase by plasma and serum ultrafiltrates due in part to a low-molecular-weight, nonpeptide material.

    PubMed

    Schwartz, P L; Turfus, I M

    1975-05-01

    In an attempt to verify the existence in the blood of a diabetogenic peptide (somantin) derived from growth hormone, ultrafiltrates from plasma and serum from normal and diabetic subjects were prepared. The freeze-dried residues of these ultrafiltrates inhibited glyceraldehyde 3-phosphate dehydrogenase as somantin is claimed to do. However, the behavior of the inhibitory material on gel filtration on Sephadex G-10 indicated a molecular weight well below 700, rather than the considerably larger size claimed for somantin. The inhibitory material did not adsorb to Dowex 50W cation exchange resin at pH 2.5, while over 95 percent of ninhydrin-positive material was retained. Acid hydrolysis of the inhibitory material did not abolish its activity. Because of the presence of this low-molecular-weight, nonpeptide inhibitory material, inhibition of glyceraldehyde 3-phosphate dehydrogenase by a simple ultrafiltrate of plasma or serum is probably not a definitive measure of somantin. PMID:1128227

  12. AMS radiocarbon dating of Middle and Upper Palaeolithic bone in the British Isles: improved reliability using ultrafiltration

    NASA Astrophysics Data System (ADS)

    Jacobi, R. M.; Higham, T. F. G.; Bronk Ramsey, C.

    2006-07-01

    Recent research at the Oxford Radiocarbon Accelerator Unit (ORAU) has shown that ultrafiltration of gelatin from archaeological bone can, in many instances, remove low molecular weight contaminants. These can sometimes be of a different radiocarbon age and, unless removed, may severely influence results, particularly when dating bones greater than two to three half-lives of 14C. In this study this methodology is applied to samples of Late Middle and Early Upper Palaeolithic age from the British Isles. In many instances the results of redating invite serious reconsideration of the chronology for these periods. Copyright

  13. Study to determine the technical and economic feasibility of reclaiming chemicals used in micellar polymer and low tension surfactant flooding. Final report. [Ultrafiltration membranes and reverse osmosis membranes

    SciTech Connect

    Stephens, R.H.; Himmelblau, A.; Donnelly, R.G.

    1978-02-01

    Energy Resources Company has developed a technology for use with enhanced oil recovery to achieve emulsion breaking and surfactant recovery. By using ultrafiltration membranes, the Energy Resources Company process can dewater an oil-in-water type emulsion expected from enhanced oil recovery projects to the point where the emulsion can be inverted and treated using conventional emulsion-treating equipment. By using a tight ultrafiltration membrane or a reverse osmosis membrane, the Energy Resources Company process is capable of recovering chemicals such as surfactants used in micellar polymer flooding.

  14. Recovery of Bacillus licheniformis Alkaline Protease from Supernatant of Fermented Wastewater Sludge Using Ultrafiltration and Its Characterization

    PubMed Central

    Bezawada, Jyothi; Yan, S.; John, Rojan P.; Tyagi, R. D.; Surampalli, R. Y.

    2011-01-01

    Investigation on recovery of alkaline protease from B. licheniformis ATCC 21424 fermented wastewater sludge was carried out by centrifugation and ultrafiltration. Optimization of ultrafiltration parameters (transmembrane pressure (TMP) and feed flux) was carried out with 10 kDa membrane. TMP of 90 kPa and feed flux of 714 L/h/m2 gave highest recovery (83%) of the enzyme from the centrifuged supernatant. The recovered enzyme had given maximum activity at temperature of 60°C and at pH 10. It was stable between pH 8 to 10 and retained 97% activity at 60°C after 180 min of incubation. Enzyme activity was significantly augmented by metal ions like Ca2+ and Mn2+. Protease inhibitors like phenylmethyl sulphonyl fluoride (PMSF) and diisopropyl fluorophosphates (DFPs) completely inhibited the enzyme activity. The partially purified protease showed excellent stability and compatibility with various commercial detergents. The detergent (Sunlight) removed the blood stains effectively along with the enzyme as additive. PMID:21876816

  15. Influence of hydrophobic/hydrophilic fractions of extracellular organic matters of Microcystis aeruginosa on ultrafiltration membrane fouling.

    PubMed

    Zhou, Shiqing; Shao, Yisheng; Gao, Naiyun; Li, Lei; Deng, Jing; Tan, Chaoqun; Zhu, Mingqiu

    2014-02-01

    Fouling is a major obstacle to maintain the efficiency of ultrafiltration-based drinking water treatment process. Algal extracellular organic matters (EOMs) are currently considered as one of the major sources of membrane fouling. The objective of this study was to investigate the influence of different hydrophobic/hydrophilic fractions of EOM extracted from Microcystis aeruginosa on ultrafiltration membrane fouling at lab scale. The experimental data indicated that EOM exhibited similar flux decline trends on polyethersulfone (PES) and regenerated cellulose (RC) membranes but caused greater irreversible fouling on PES membrane than RC membrane due to its hydrophobic property. It was also observed that charged hydrophilic (CHPI) and neutral hydrophilic (NHPI) fractions caused greater flux decline over hydrophobic (HPO) and transphilic (TPI) fractions. For PES membrane, the order of the irreversible fouling potentials for the four fractions was HPO>TPI>CHPI>NHPI, while the irreversible fouling potentials of RC membrane were tiny and could be ignored. Fluorescence excitation-emission matrix (EEM) spectra and Fourier transform infrared (FTIR) spectra suggested that protein-like, polysaccharide-like and humic-like substances were the major components responsible for membrane fouling. The results also indicated that the irreversible fouling increased as the pH decreased. The addition of calcium to feed solutions led to more severe flux decline and irreversible fouling.

  16. [Investigation of the copper content in blood serum and its ultrafiltrate in the conditions of experimental space flight simulation].

    PubMed

    Piruzian, L A; Protasova, O V; Maksimova, I A; Morukov, B V; Protasov, S V; Ushakov, I B

    2013-01-01

    In experiment MARS-500 on remote space flight simulation, atomic emission spectral analysis with inductively coupled argon plasma was used to measure serum copper and its ultrafiltration fraction. It was shown that, in contrast to baseline data, the Cu serum level varied within the normal physiological boundaries throughout the entire simulation experiment. These variations were sync in all the serum samples. In several periods in the experiment reductions in serum Cu within the baseline range were equivalent to simultaneous reductions in ceruloplasmin. Amount of the free Cu (ultrafiltration) fraction, i.e. not bound to proteins in blood serum, was constant at all times. Since the simulation experiment is not a perfect analogy of space flight because of nonreproducibility of some factors, ionizing radiation specifically, we should take into consideration shifts in the serum copper balance caused by the action of space radiation on human organism. Radiation-induced imbalance is not only a marker of disturbed oxidase function of blood but also points to a mechanism of potential pathological outcome of toxic excessive copper accumulated in the brain, liver and kidney.

  17. LDL and HDL transfer rates across peripheral microvascular endothelium agree with those predicted for passive ultrafiltration in humans

    PubMed Central

    Michel, C. Charles; Nanjee, M. Nazeem; Olszewski, Waldemar L.; Miller, Norman E.

    2015-01-01

    The mechanisms by which LDLs and HDLs cross the vascular endothelium from plasma into interstitial fluid are not understood, and have never been studied in humans in vivo. We determined whether the plasma-to-lymph clearance rates of LDL and HDL conform with those predicted by passive ultrafiltration through intercellular pores, or if it is necessary to invoke an active process such as receptor-mediated transcytosis. Plasma and afferent peripheral lymph were collected under steady-state conditions from 30 healthy men, and assayed for seven globular proteins of molecular radii 2.89–8.95 nm, complement C3, and apo AI, apo AII, and apo B. Plasma-to-lymph clearance rates of the seven proteins fitted the relation expected for molecules of their size when transported through two populations of pores of radius 4.95 and 20.1 nm. The same model parameters were then found to accurately predict the clearance rates of both HDL and LDL. The apparent clearance of complement C3, previously shown to be secreted by cultured endothelium, exceeded that predicted by the model. We conclude that the transport of HDL and LDL from plasma into interstitial fluid across the peripheral vascular endothelium in healthy humans can be explained by ultrafiltration without invoking an additional active process such as transcytosis. PMID:25398615

  18. Evaluation of Membrane Ultrafiltration and Residual Chlorination as a Decentralized Water Treatment Strategy for Ten Rural Healthcare Facilities in Rwanda

    PubMed Central

    Huttinger, Alexandra; Dreibelbis, Robert; Roha, Kristin; Ngabo, Fidel; Kayigamba, Felix; Mfura, Leodomir; Moe, Christine

    2015-01-01

    There is a critical need for safe water in healthcare facilities (HCF) in low-income countries. HCF rely on water supplies that may require additional on-site treatment, and need sustainable technologies that can deliver sufficient quantities of water. Water treatment systems (WTS) that utilize ultrafiltration membranes for water treatment can be a useful technology in low-income countries, but studies have not systematically examined the feasibility of this technology in low-income settings. We monitored 22 months of operation of 10 WTS, including pre-filtration, membrane ultrafiltration, and chlorine residual disinfection that were donated to and operated by rural HCF in Rwanda. The systems were fully operational for 74% of the observation period. The most frequent reasons for interruption were water shortage (8%) and failure of the chlorination mechanism (7%). When systems were operational, 98% of water samples collected from the HCF taps met World Health Organization (WHO) guidelines for microbiological water quality. Water quality deteriorated during treatment interruptions and when water was stored in containers. Sustained performance of the systems depended primarily on organizational factors: the ability of the HCF technician to perform routine servicing and repairs, and environmental factors: water and power availability and procurement of materials, including chlorine and replacement parts in Rwanda. PMID:26516883

  19. Unmodified starch as water-soluble binding polymer for chromium ions removal via polymer enhanced ultrafiltration system

    PubMed Central

    2014-01-01

    Background In this study the removal of Chromium (III) and Chromium (VI) ions are investigated via polymer enhanced ultrafiltration under important process parameters. This study proposes the use of unmodified starch as a novel polymer in the ultrafiltration process and its performance on the removal of chromium ions was compared with a commonly used polymer, polyethylene glycol. Methods The experiments were carried out at 1.5 bar and different pH values by using 10 kDa hollow fiber membrane operating in a cross-flow mode. Results The best chromium ions removal obtained approached 99% for Chromium (III) ion by unmodified starch at alkaline pH region and at pH 7 for Chromium (VI) ions retention by polyethylene glycol. Permeate flux behavior are fluctuated for both chromium ions tested at high metal ion concentrations. Low concentration of unmodified starch is applied to reduce gelatinization behavior. Conclusions The findings suggest that binding of chromium ions by unmodified starch is related to granule structure which is probably a principal indicator of the non-ionic behavior of unmodified starch. PMID:24618019

  20. Integration of polyelectrolyte enhanced ultrafiltration and chemical reduction for metal-containing wastewater treatment and metal recovery.

    PubMed

    Yu, Jui-Hsuan; Chou, Yi-Hsuan; Liang, Yang-Min; Li, Chi-Wang

    2015-01-01

    Chemical reduction was firstly employed to treat synthetic wastewaters of various compositions prepared to simulate the retentate stream of polyelectrolyte enhanced ultrafiltration (PEUF). With fixed Cu:polyethylenimine (PEI) monomer:dithionite molar ratio, increasing copper concentration increases copper removal efficiency. Under fixed Cu:dithionite molar ratio and fixed Cu concentration, increasing PEI monomer:copper molar ratio decreases copper removal efficiency. The formation of nano-sized copper particles, which readily pass through 0.45 μm filter used for sample pretreatment before residual copper analysis, might be the reason behind the decreasing copper removal efficiency observed. Particle size analysis shows that the size of copper particles, which are formed through reduction reaction, increases with decreasing pH value and increasing reaction time. As ultrafiltration is capable of removing these nano-sized particles, integration of chemical reduction and PEUF is proposed to simultaneously achieve regeneration of polyelectrolyte and recovery of copper in one process. Results show that the proposed process could achieve almost complete copper removal without being affected by reaction pH. PMID:26398024

  1. Evaluation of Membrane Ultrafiltration and Residual Chlorination as a Decentralized Water Treatment Strategy for Ten Rural Healthcare Facilities in Rwanda.

    PubMed

    Huttinger, Alexandra; Dreibelbis, Robert; Roha, Kristin; Ngabo, Fidel; Kayigamba, Felix; Mfura, Leodomir; Moe, Christine

    2015-10-01

    There is a critical need for safe water in healthcare facilities (HCF) in low-income countries. HCF rely on water supplies that may require additional on-site treatment, and need sustainable technologies that can deliver sufficient quantities of water. Water treatment systems (WTS) that utilize ultrafiltration membranes for water treatment can be a useful technology in low-income countries, but studies have not systematically examined the feasibility of this technology in low-income settings. We monitored 22 months of operation of 10 WTS, including pre-filtration, membrane ultrafiltration, and chlorine residual disinfection that were donated to and operated by rural HCF in Rwanda. The systems were fully operational for 74% of the observation period. The most frequent reasons for interruption were water shortage (8%) and failure of the chlorination mechanism (7%). When systems were operational, 98% of water samples collected from the HCF taps met World Health Organization (WHO) guidelines for microbiological water quality. Water quality deteriorated during treatment interruptions and when water was stored in containers. Sustained performance of the systems depended primarily on organizational factors: the ability of the HCF technician to perform routine servicing and repairs, and environmental factors: water and power availability and procurement of materials, including chlorine and replacement parts in Rwanda. PMID:26516883

  2. Characterization of natural low-methoxyl pectin from sunflower head extracted by sodium citrate and purified by ultrafiltration.

    PubMed

    Kang, Jiaqi; Hua, Xiao; Yang, Ruijin; Chen, Ying; Yang, Hui

    2015-08-01

    Sunflower head pectin was extracted by 0.6% (w/v) sodium citrate under 85°C, 3.5h with a solid to liquid ratio of 1:40, giving the maximum uronic acid yield of 16.90% (w/w). The extract was purified by an ultrafiltration membrane with the molecular weight cut-off of 8000 Da and dried by spray-drying to obtain SFHP(A) powders with particle diameters of 2-5 μm. In comparison to the SFHP(B) extracted by ammonium oxalate and isolated by alcohol, SFHP(A) had a close DM (22.56%) but a considerably lower DAm (3.42%). HPSEC-MALLS analysis suggested that SFHP(A) has undergo a deeper degradation resulting in smaller Mw and Mn. HPAEC-PAD showed that SFHP(A) contains more neutral sugars since the degraded RG fragments have been retained during ultrafiltration. Finally, pectin aggregation in aqueous was investigated by FEG-SEM, which reveals that pectin network structure is constructed by microfilaments via coiling, intertwining and crosslinking.

  3. Characterization of natural low-methoxyl pectin from sunflower head extracted by sodium citrate and purified by ultrafiltration.

    PubMed

    Kang, Jiaqi; Hua, Xiao; Yang, Ruijin; Chen, Ying; Yang, Hui

    2015-08-01

    Sunflower head pectin was extracted by 0.6% (w/v) sodium citrate under 85°C, 3.5h with a solid to liquid ratio of 1:40, giving the maximum uronic acid yield of 16.90% (w/w). The extract was purified by an ultrafiltration membrane with the molecular weight cut-off of 8000 Da and dried by spray-drying to obtain SFHP(A) powders with particle diameters of 2-5 μm. In comparison to the SFHP(B) extracted by ammonium oxalate and isolated by alcohol, SFHP(A) had a close DM (22.56%) but a considerably lower DAm (3.42%). HPSEC-MALLS analysis suggested that SFHP(A) has undergo a deeper degradation resulting in smaller Mw and Mn. HPAEC-PAD showed that SFHP(A) contains more neutral sugars since the degraded RG fragments have been retained during ultrafiltration. Finally, pectin aggregation in aqueous was investigated by FEG-SEM, which reveals that pectin network structure is constructed by microfilaments via coiling, intertwining and crosslinking. PMID:25766806

  4. Coupling ultrafiltration with an activated carbon cloth for the treatment of highly coloured wastewaters: a techno-economic study.

    PubMed

    Métivier-Pignon, H; Faur-Brasquet, C; Jaouen, P; Le Cloirec, P

    2003-06-01

    This work investigates the coupling of a membrane technique, ultrafiltration, with a recent adsorbent, activated carbon cloth for the treatment of industrial highly coloured wastewaters. A first experimental part shows the high treatment ability of this process for fountain-pen inks effluents arising from the rinsing of vats in which inks were produced. Whereas ultrafiltration enables more than 97% of colour removal, COD and DOC are not completely retained and a residual value of 1,700 mg l(-1) of DOC is obtained in the permeate. The second step of the process, activated carbon cloth, allows residual organic matter to be removed and a complete discolouring of the permeate. Adsorption capacities of COD and DOC are high, equal to 500 and 250 mg g(-1) respectively. Furthermore, this adsorbent induces a complete removal of glycol compounds (acting as antifreeze) which were not retined by a nanofiltration technique. A second part is an evaluation of the economic feasibility of such an integrated process. Only direct costs are considered at this phase of the study, and are divided into fixed costs (equipment, depreciation, maintenance), variable costs (electricity and consumption) and labour costs. The technical-economic study is carried out for two configurations: a low capacity unit (the UF membrane area is 2.4 m2) and an industrial capacity unit (with a 100 m2 UF membrane). Costs per treated m3 are respectively 111 and 32 euros, with costs partitioning which are dependent on the unit capacity.

  5. Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment

    PubMed Central

    Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P.; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

    2015-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEONLA-BSA, which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEONLA-BSA particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEONLA-BSA changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment. PMID:26287178

  6. Floc characterization and membrane fouling of polyferric-polymer dual/composite coagulants in coagulation/ultrafiltration hybrid process.

    PubMed

    Rong, Hongyan; Gao, Baoyu; Li, Junchao; Zhang, Bei; Sun, Shenglei; Wang, Yan; Yue, Qinyan; Li, Qian

    2013-12-15

    Papermaking sludge and spent pickling liquor were recycled to synthesize a macromolecular lignin-acrylamide polymer (LA) and polyferric chloride (PFC), respectively. The dual-coagulant PFC-LA (PFC and LA were dosed orderly), composite coagulant PFCLA (PFC and LA premixed before dosed) and PFC were used in coagulation/ultrafiltration hybrid process in surface water treatment. The objectives of this paper are to comparatively investigate final water quality after coagulation and coagulation/ultrafiltration process and floc properties, including floc size, strength, recoverability and floc structure, with or without LA addition. Additionally, the relationship between membrane fouling and floc characteristics was discussed. The results showed that best final water quality was obtained by PFC-LA, sequentially followed by PFCLA and PFC. Floc size, growth rate, strength and recoverability as well as fractal dimension were also in the order of PFC-LA>PFCLA>PFC. The maximum permeate fluxes before and after backwash operation were obtained by PFC-LA, which gave the largest and most compact flocs. Coagulation suspension after breakage resulted in much more serious membrane fouling for PFC, whereas permeate flux slightly decreased when LA was used in combination with PFC. PMID:24144372

  7. Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment.

    PubMed

    Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

    2015-08-14

    Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEON(LA-BSA), which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEON(LA-BSA) particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEON(LA-BSA) changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment.

  8. Slow continuous ultrafiltration (SCUF)--the safe and efficient treatment for patients with cardiac failure and fluid overload.

    PubMed

    Wei, S S; Lee, W T; Woo, K T

    1995-06-01

    Slow Continuous ultrafiltration (SCUF) was first used in 1980 as an alternative mode of fluid removal for patients with oliguric acute renal dysfunction from whatever causes. The advantage of this treatment is that haemodynamic parameters remain stable in the presence of significant removal of fluid. We are describing our experience in 7 patients [age: 57 +/- 9 years; 4 male, 3 female] with cardiac failure and fluid overload who had undergone 8 sessions of SCUF. All of them had renal impairment and were resistant to diuretics. Blood lines were attached to a Kawasumi Renak-E dialyser (Cuprophane membrane) in series using Gambro AK10 dialysis blood pump. The following parameters were monitored: Blood pump (Qb): 175 +/- 26 ml/min, time (T): 393 +/- minutes. Venous pressure averaged a55 +/- 24 mmHg. We achieved ultrafiltration of 2,189 +/- 699 ml/session or 5.5 +/- 1.7 ml/hr. There was no significant change in blood pressure [systolic pre: 143 +/- 14, post: 136 +/- 13 mmHg, not significant; diastolic pre: 87 +/- 10, post: 83 + 10 mmHg, not significant and pulse rate [pre: 87 +/- 9 vs post: 84 +/- 2 per minute, not significant. Heparin dosage averaged 274 +/- 26 IU/hr during the SCUF. We conclude that SCUF is beneficial to diuretic resistant patients with cardiac failure and fluid overload in whom dialysis treatment is not required.

  9. Fabrication of TiO2-modified polytetrafluoroethylene ultrafiltration membranes via plasma-enhanced surface graft pretreatment

    NASA Astrophysics Data System (ADS)

    Qian, Yingjia; Chi, Lina; Zhou, Weili; Yu, Zhenjiang; Zhang, Zhongzhi; Zhang, Zhenjia; Jiang, Zheng

    2016-01-01

    Surface hydrophilic modification of polymer ultrafiltration membrane using metal oxide represents an effective yet highly challenging solution to improve water flux and antifouling performance. Via plasma-enhanced graft of poly acryl acid (PAA) prior to coating TiO2, we successfully fixed TiO2 functional thin layer on super hydrophobic polytetrafluoroethylene (PTFE) ultrafiltration (UF) membranes. The characterization results evidenced TiO2 attached on the PTFE-based UF membranes through the chelating bidentate coordination between surface-grafted carboxyl group and Ti4+. The TiO2 surface modification may greatly reduce the water contact angle from 115.8° of the PTFE membrane to 35.0° without degradation in 30-day continuous filtration operations. The novel TiO2/PAA/PTFE membranes also exhibited excellent antifouling and self-cleaning performance due to the intrinsic hydrophilicity and photocatalysis properties of TiO2, which was further confirmed by the photo-degradation of MB under Xe lamp irradiation.

  10. Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment.

    PubMed

    Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

    2015-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEON(LA-BSA), which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEON(LA-BSA) particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEON(LA-BSA) changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment. PMID:26287178

  11. Ultrafiltration by a compacted clay membrane. I - Oxygen and hydrogen isotopic fractionation. II - Sodium ion exclusion at various ionic strengths.

    NASA Technical Reports Server (NTRS)

    Coplen, T. B.; Hanshaw, B. B.

    1973-01-01

    Laboratory experiments were carried out to determine the magnitude of the isotopic fractionation of distilled water and of 0.01N NaCl forced to flow at ambient temperature under a hydraulic pressure drop of 100 bars across a montmorillonite disk compacted to a porosity of 35% by a pressure of 330 bars. The ultrafiltrates in both experiments were depleted in D by 2.5% and in O-18 by 0.8% relative to the residual solution. No additional isotopic fractionation due to a salt-filtering mechanism was observed at NaCl concentrations up to 0.01N. Adsorption is most likely the principal mechanism which produces isotopic fractionation, but molecular diffusion may play a minor role. The results suggest that oxygen and hydrogen isotopic fractionation of ground water during passage through compacted clayey sediments should be a common occurrence, in accord with published interpretations of isotopic data from the Illinois and Alberta basins. It is shown how it is possible to proceed from the ion exchange capacity of clay minerals and, by means of the Donnan membrane equilibrium concept and the Teorell-Meyer-Siever theory, develop a theory to explain why and to what extent ultrafiltration occurs when solutions of known concentration are forced to flow through a clay membrane.

  12. Studies on preparation of medium fat liquid dairy whitener from buffalo milk employing ultrafiltration process.

    PubMed

    Khatkar, Sunil Kumar; Gupta, Vijay Kumar; Khatkar, Anju Boora

    2014-09-01

    A study was conducted to develop good quality medium fat liquid dairy whitener from buffalo milk employing ultrafiltration (UF) process. The buffalo skim milk was UF concentrated to 4.05 to 4.18 (23.63 ± 0.30 % TS) fold and standardized to 10 % fat (on Dry Matter Basis) (i.e. formulation) and homogenized at 175.76 kg/cm(2). The addition of 0.4 % mixture of monosodium and disodium phosphate (2:1 w/w) improved the heat stability of homogenized formulation to an optimum of 66 min. The bland flavour of homogenized formulation with added 0.4 % mixture of monosodium phosphate and disodium phosphate (2:1 w/w) and 18 % sugar (on DMB) (i.e. medium fat liquid dairy whitener) was improved significantly (P < 0.01) with the addition of 0.2 % potassium chloride, but heat stability of medium fat liquid dairy whitener got reduced substantially (i.e. 19 min). With subsequent heat treatment to 85 °C for 5 min, heat stability of medium fat liquid dairy whitener got improved to reasonable level of 27 min. Whitening ability in terms of L* value of medium fat liquid dairy whitener in both tea and coffee was significantly (P < 0.01) better when homogenized at 175.76 kg/cm(2) vis-à-vis 140.61 kg/cm(2). Standardized medium fat liquid dairy whitener had significantly (P < 0.01) greater protein content (i.e. approximately 2.43 times) compared to market dairy whitener samples. At 2 % solids level, standardized medium fat liquid dairy whitener in tea/coffee fetched significantly (P < 0.01) better sensory attributes and instrumental whitening ability compared to market sample at 3 % solids level. There could be clear 33 % solids quantity saving in case of developed product compared to market dairy whitener sample.

  13. Analytical fractionation of aquatic humic substances and their metal species by means of multistage ultrafiltration.

    PubMed

    Aster, B; Burba, P; Broekaert, J A

    1996-03-01

    The molecular-size fractionation of aquatic humic substances (HS) and their metal species by means of a novel sequential-stage ultrafiltration (UF) device equipped with five appropriate ultramembranes (1, 5, 10, 50 and 100 kD) is described. First of all, the concentration dynamics of macromolecules, particulary HS, during five-stage UF and its subsequent washing step has been modelled. Based on these results, the fractionation of aquatic HS (from ground and bog water) by means of multistage UF has been optimized for an analytical scale (10 ml sample, 1 mg/ml HS, 10 ml washing solution, pH 6.0). The molecular size-distribution of selected aquatic HS (BOC 1/2 from the "DFG-Versuchsfeld Bocholt", VM 5 from "Venner Moor", Germany) studied by five-stage UF exhibited strong systematic influences of the procedure used for their isolation. The molecular-size distribution of HS obtained by on-line UF and gel permeation chromatography (GPC) showed a satisfactory agreement in the range 1-50 kD. Moreover, when interrupting multistage UF for > 48 h a slow transformation in the HS samples has been found as gradually additional HS fractions of < 1 kD have been formed. Besides unloaded HS molecules, the molecular-size distribution of freshly formed metal species of HS (1.0 mg metal/g HS of Al(III), Cd(II), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), Zn(II), each) has been characterized by multistage UF as a function of pH-value, degree of loading and complexation time. Metal determinations as carried out by flame AAS, showed that considerable metal fractions in HS especially are present in molecules > 50 kD, which seemed to be rather acid-inert. With complexation times of < 2 days a transient shift of the molecular size distribution of both HS and their metal species (e.g., Al(III), Fe(III) to higher values (> 10 kD) has been found.

  14. Optimisation of sample treatment for arsenic speciation in alga samples by focussed sonication and ultrafiltration.

    PubMed

    Salgado, S García; Quijano Nieto, M A; Bonilla Simón, M M

    2006-02-28

    A procedure for arsenic species fractionation in alga samples (Sargassum fulvellum, Chlorella vulgaris, Hizikia fusiformis and Laminaria digitata) by extraction is described. Several parameters were tested in order to evaluate the extraction efficiency of the process: extraction medium, nature and concentration (tris(hydroxymethyl)aminomethane, phosphoric acid, deionised water and water/methanol mixtures), extraction time and physical treatment (magnetic stirring, ultrasonic bath and ultrasonic focussed probe). The extraction yield of arsenic under the different conditions was evaluated by determining the total arsenic content in the extracts by ICP-AES. Arsenic compounds were extracted in 5mL of water by focussed sonication for 30s and subsequent centrifugation at 14,000xg for 10min. The process was repeated three times. Extraction studies show that soluble arsenic compounds account for about 65% of total arsenic. An ultrafiltration process was used as a clean-up method for chromatographic analysis, and also allowed us to determine the extracted arsenic fraction with a molecular weight lower than 10kDa, which accounts for about 100% for all samples analysed. Speciation studies were carried out by HPLC-ICP-AES. Arsenic species were separated on a Hamilton PRP-X100 column with 17mM phosphate buffer at pH 5.5 and 1.0mLmin(-1) flow rate. The chromatographic method allowed us to separate the species As(III), As(V), MMA and DMA in less than 13min, with detection limits of about 20ng of arsenic per species, for a sample injection volume of 100muL. The chromatographic analysis allowed us to identify As(V) in Hizikia (46+/-2mugg(-1)), Sargassum (38+/-2mugg(-1)) and Chlorella (9+/-1mugg(-1)) samples. The species DMA was also found in Chlorella alga (13+/-1mugg(-1)). However, in Laminaria alga only an unknown arsenic species was detected, which eluted in the dead volume. PMID:18970494

  15. High-flux Thin-film Nanofibrous Composite Ultrafiltration Membranes Containing Cellulose Barrier Layer

    SciTech Connect

    Ma, H.; Yoon, K; Rong, L; Mao, Y; Mo, Z; Fang, D; Hollander, Z; Gaiteri, J; Hsiao , B; Chu, B

    2010-01-01

    A novel class of thin-film nanofibrous composite (TFNC) membrane consisting of a cellulose barrier layer, a nanofibrous mid-layer scaffold, and a melt-blown non-woven substrate was successfully fabricated and tested as an ultrafiltration (UF) filter to separate an emulsified oil and water mixture, a model bilge water for on-board ship bilge water purification. Two ionic liquids: 1-butyl-3-methylimidazolium chloride and 1-ethyl-3-methylimidazolium acetate, were chosen as the solvent to dissolve cellulose under mild conditions. The regenerated cellulose barrier layer exhibited less crystallinity (determined by wide-angle X-ray diffraction, WAXD) than the original cotton linter pulps, but good thermal stability (determined by thermal gravimetric analysis, TGA). The morphology, water permeation, and mechanical stability of the chosen TFNCmembranes were thoroughly investigated. The results indicated that the polyacrylonitrile (PAN) nanofibrous scaffold was partially imbedded in the cellulose barrier layer, which enhanced the mechanical strength of the top barrier layer. The permeation flux of the cellulose-based TFNCmembrane was significantly higher (e.g. 10x) than comparable commercial UFmembranes (PAN10 and PAN400, Sepro) with similar rejection ratios for separation of oil/water emulsions. The molecular weight cut-off (MWCO) of TFNC membranes with cellulose barrier layer was evaluated using dextran feed solutions. The rejection was found to be higher than 90% with a dextran molecular weight of 2000 KDa, implying that the nominal pore size of the membrane was less than 50 nm. High permeation flux was also observed in the filtration of an emulsified oil/water mixture as well as of a sodium alginate aqueous solution, while high rejection ratio (above 99.5%) was maintained after prolonged operation. A variation of the barrier layer thickness could dramatically affect the permeation flux and the rejection ratio of the TFNCmembranes, while different sources of cellulose

  16. Preconcentration of low levels of americium and plutonium from waste waters by synthetic water-soluble metal-binding polymers with ultrafiltration

    SciTech Connect

    Smith, B.F.; Gibson, R.R.; Jarvinen, G.D.; Robison, T.W.; Schroeder, N.C.; Stalnaker, N.D.

    1997-12-31

    A preconcentration approach to assist in the measurement of low levels of americium and plutonium in waste waters has been developed based on the concept of using water-soluble metal-binding polymers in combination with ultrafiltration. The method has been optimized to give over 90% recovery and accountability from actual waste water.

  17. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - PHYSICAL REMOVAL OF PARTICULATE CONTAMINANTS IN DRINKING WATER: POLYMEM UF 120 S2 ULTRAFILTRATION MEMBRANE MODULE, LUXENBURG, WISCONSIN

    EPA Science Inventory

    Verification testing of the Polymem UF120 S2 Ultrafiltration Membrane Module was conducted over a 46-day period at the Green Bay Water Utility Filtration Plant, Luxemburg, Wisconsin. The ETV testing described herein was funded in conjunction with a 12-month membrane pilot study f...

  18. [Ultrafiltration as a fast and simple method for determination of free and protein bound prilocaine concentration. Clinical study following high-dose plexus anesthesia].

    PubMed

    Bachmann-Mennenga, B; Biscoping, J; Schürg, R; Sinning, E; Hempelmann, G

    1991-05-01

    Ultrafiltration as a Fast and Simple Method to Separate Free and Protein Bound Concentrations of Local Anesthetics/Pharmacokinetic studies following high-dose anesthesia of the axillary plexus. As many other drugs amide-type local anesthetics are protein bound in plasma. The extent of binding varies between local anesthetics. The free, non protein-bound fraction of these drugs is mainly responsible for cardiovascular and central-nervous side effects. If high doses are necessary for regional anesthetic procedures it seems reasonable to determine the pharmacological active, non protein-bound fraction in addition to the total concentration of the local anesthetic drug. Analyses of protein binding was performed using an ultrafiltration method which is discussed in this paper. Total (HPLC) and unbound plasma levels (combination of ultrafiltration and HPLC) of the local anesthetic drug in central venous blood were studied in 20 healthy orthopedic patients, undergoing plastic surgery of the upper limb (elbow, forearm, hand), over a time period of 90 min, when performing axillary plexus block with 30 ml prilocaine (CAS 721-50-6) 2% (= 600 mg). Separation of the local anesthetic fractions was achieved using the ultrafiltration system MPS-1, equipped with a YMT-membrane. These membranes have a narrow pore size retaining molecules larger than 30000 Dalton. Ultrafiltration was accomplished by subjecting 1.2 ml of plasma to centrifugation at 2000 x g for 60 min at 30 degrees C using a clinical centrifuge equipped with a 35 degree angle head rotor. The plasma samples were adjusted to physiological pH (7.40) with a sodium-potassium-phosphate buffer. The tightness of the used membrane was controlled by a micromethod for protein estimation (sensitivity 10 micrograms/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Zenon Environmental, Inc.: ZenoGem{trademark} biological and ultrafiltration technology. Innovative technology evaluation report; Superfund innovative technology evaluation

    SciTech Connect

    1999-04-01

    Zenon Environmental Inc. (Zenon), of Burlington, Ontario, Canada had developed an innovative wastewater treatment technology called the ZenoGem{trademark} technology. The ZenoGem{trademark} technology integrates biological treatment with membrane-based ultrafiltration to treat wastewater with high concentrations of organic contaminants that cause elevated concentrations of chemical oxygen demand (COD). The Superfund Innovative Technology Evaluation (SITE) demonstration occurred between September and December 1994 at the Nascolite Superfund site (Nascolite) in Millville, Cumberland County, New Jersey. During the SITE demonstration, critical and noncritical measurements were evaluated. Critical measurements consisted of sample analyses and process measurements that directly impacted meeting the project`s primary technical objective. Critical measurements included collection of liquid and air samples for MMA and VOC analyses; liquid samples to evaluate COD; and flow rate measurements of the influent and effluent liquid streams. Noncritical, or system condition measurements, provided information on operating ranges, reliability, variability, cost-effectiveness, and full-scale remediation potential of the technology.

  20. Screening and determination of potential xanthine oxidase inhibitors from Radix Salviae Miltiorrhizae using ultrafiltration liquid chromatography-mass spectrometry.

    PubMed

    Liu, Yang; Liu, Shu; Liu, Zhiqiang

    2013-04-01

    Xanthine oxidase (XOD) inhibitors play an important role in the treatment of gout and many other diseases related to the superoxide anion metabolism. In this study, an ultrafiltration-liquid chromatography-mass spectrometry (UF-LC-MS) method was developed for the screening and identification of potential XOD inhibitors from Radix Salviae Miltiorrhizae extract. Eleven lipophilic diterpenoid quinines were identified as XOD inhibitors from the extract. The relationship between the structure and activity of the detected compounds was estimated on the basis of the UF-LC-MS data. The results demonstrate that the 1,2-naphthoquinone group is necessary for the XOD inhibitory activity of the compounds, and that furan and hydroxyl on the alicyclic ring could enhance the activity of the compounds at different levels. These results may explain and support the medical use of the extract of Radix S. Miltiorrhizae for the prevention and treatment of hyperuricemia and gout.

  1. Treatment of a waste oil-in-water emulsion from a copper-rolling process by ultrafiltration and vacuum evaporation.

    PubMed

    Gutiérrez, Gemma; Lobo, Alberto; Benito, José M; Coca, José; Pazos, Carmen

    2011-01-30

    A process is proposed for the treatment of a waste oil-in-water (O/W) emulsion generated in an industrial copper-rolling operation. The use of demulsifier agents improves the subsequent treatment by techniques such as ultrafiltration (UF) or evaporation. The effluent COD is reduced up to 50% when the O/W emulsion is treated by UF using a flat 30 nm TiO(2) ceramic membrane (ΔP = 0.1 MPa) and up to 70% when it is treated by vacuum evaporation, after an emulsion destabilization pretreatment in both cases. Increases in the UF permeate flux and in the evaporation rate are observed when a chemical demulsifier is used in the pretreatment step. A combined process consisting of destabilization/settling, UF, and vacuum evaporation can yield a very high-quality aqueous effluent that could be used for process cooling or emulsion reformulation.

  2. Central treatment of different emulsion wastewaters by an integrated process of physicochemically enhanced ultrafiltration and anaerobic-aerobic biofilm reactor.

    PubMed

    Zhang, Weijun; Xiao, Ping; Wang, Dongsheng

    2014-05-01

    The feasibility of an integrated process of ultrafiltration (UF) enhanced by combined chemical emulsion breaking with vibratory shear and anaerobic/aerobic biofilm reactor for central treatment of different emulsion wastewaters was investigated. Firstly, it was found that calcium chloride exhibited better performance in oil removal than other inorganic salts. Chemical demulsification pretreatment could efficiently improve oil removal and membrane filtration in emulsion wastewater treatment by VSEP. According to aerobic batch bioassay, UF permeate exhibited good biodegradability and could be further treated with biological process. Additionally, pilot test indicated that anaerobic-aerobic biofilm exhibited an excellent ability against rise in organic loading and overall chemical oxygen demand (COD) removal efficiency of biological system was more than 93% of which 82% corresponded to the anaerobic process and 11% to the aerobic degradation. The final effluent of integrated process could meet the "water quality standards for discharge to municipal sewers" in China.

  3. Fouling characterization and control for harvesting microalgae Arthrospira (Spirulina) maxima using a submerged, disc-type ultrafiltration membrane.

    PubMed

    Kanchanatip, Ekkachai; Su, Bo-Rung; Tulaphol, Sattrawut; Den, Walter; Grisdanurak, Nurak; Kuo, Chi-Chang

    2016-06-01

    This study characterized the fouling of a novel circular-disc ultrafiltration membrane in a submerged bioreactor system to harvest Arthrospira maxima cells. Flux-stepping study showed that the value of critical flux was below the smallest flux tested at 28.8lm(-2)h(-1), and that the membrane was to operate above the critical flux to sustain the necessary rate of cell concentration. The membrane with similar pore size but greater pore density experienced not only lesser degree of total resistance, but also possessed smaller fraction of irreversible resistance. Membrane fouling was mainly attributed to fragmented cells rather than to soluble or extracellular polymeric substances. Furthermore, flux recovery studies demonstrated that membrane relaxation and surface cleaning could partially recover fluxes for both low (6gl(-1)) and high (40gl(-1)) cell densities, whereas backwashing could fully recover fluxes. Calculation of energy consumption and cell harvesting productivity also favoured membrane filtration with backwashing. PMID:26946437

  4. Ultrafiltration and Microarray for Detection of Microbial Source Tracking Marker and Pathogen Genes in Riverine and Marine Systems.

    PubMed

    Li, Xiang; Harwood, Valerie J; Nayak, Bina; Weidhaas, Jennifer L

    2016-01-04

    Pathogen identification and microbial source tracking (MST) to identify sources of fecal pollution improve evaluation of water quality. They contribute to improved assessment of human health risks and remediation of pollution sources. An MST microarray was used to simultaneously detect genes for multiple pathogens and indicators of fecal pollution in freshwater, marine water, sewage-contaminated freshwater and marine water, and treated wastewater. Dead-end ultrafiltration (DEUF) was used to concentrate organisms from water samples, yielding a recovery efficiency of >95% for Escherichia coli and human polyomavirus. Whole-genome amplification (WGA) increased gene copies from ultrafiltered samples and increased the sensitivity of the microarray. Viruses (adenovirus, bocavirus, hepatitis A virus, and human polyomaviruses) were detected in sewage-contaminated samples. Pathogens such as Legionella pneumophila, Shigella flexneri, and Campylobacter fetus were detected along with genes conferring resistance to aminoglycosides, beta-lactams, and tetracycline. Nonmetric dimensional analysis of MST marker genes grouped sewage-spiked freshwater and marine samples with sewage and apart from other fecal sources. The sensitivity (percent true positives) of the microarray probes for gene targets anticipated in sewage was 51 to 57% and was lower than the specificity (percent true negatives; 79 to 81%). A linear relationship between gene copies determined by quantitative PCR and microarray fluorescence was found, indicating the semiquantitative nature of the MST microarray. These results indicate that ultrafiltration coupled with WGA provides sufficient nucleic acids for detection of viruses, bacteria, protozoa, and antibiotic resistance genes by the microarray in applications ranging from beach monitoring to risk assessment.

  5. Ultrafiltration and Microarray for Detection of Microbial Source Tracking Marker and Pathogen Genes in Riverine and Marine Systems.

    PubMed

    Li, Xiang; Harwood, Valerie J; Nayak, Bina; Weidhaas, Jennifer L

    2016-03-01

    Pathogen identification and microbial source tracking (MST) to identify sources of fecal pollution improve evaluation of water quality. They contribute to improved assessment of human health risks and remediation of pollution sources. An MST microarray was used to simultaneously detect genes for multiple pathogens and indicators of fecal pollution in freshwater, marine water, sewage-contaminated freshwater and marine water, and treated wastewater. Dead-end ultrafiltration (DEUF) was used to concentrate organisms from water samples, yielding a recovery efficiency of >95% for Escherichia coli and human polyomavirus. Whole-genome amplification (WGA) increased gene copies from ultrafiltered samples and increased the sensitivity of the microarray. Viruses (adenovirus, bocavirus, hepatitis A virus, and human polyomaviruses) were detected in sewage-contaminated samples. Pathogens such as Legionella pneumophila, Shigella flexneri, and Campylobacter fetus were detected along with genes conferring resistance to aminoglycosides, beta-lactams, and tetracycline. Nonmetric dimensional analysis of MST marker genes grouped sewage-spiked freshwater and marine samples with sewage and apart from other fecal sources. The sensitivity (percent true positives) of the microarray probes for gene targets anticipated in sewage was 51 to 57% and was lower than the specificity (percent true negatives; 79 to 81%). A linear relationship between gene copies determined by quantitative PCR and microarray fluorescence was found, indicating the semiquantitative nature of the MST microarray. These results indicate that ultrafiltration coupled with WGA provides sufficient nucleic acids for detection of viruses, bacteria, protozoa, and antibiotic resistance genes by the microarray in applications ranging from beach monitoring to risk assessment. PMID:26729716

  6. The removal of organic precursors of DBPs during three advanced water treatment processes including ultrafiltration, biofiltration, and ozonation.

    PubMed

    Zha, Xiao-Song; Ma, Lu-Ming; Wu, Jin; Liu, Yan

    2016-08-01

    The removal efficiency of organic matter, the formation potential of trihalomethanes (THMFP), and the formation potential of haloacetic acids (HAAFP) in each unit of three advanced treatment processes were investigated in this paper. The molecular weight distribution and the components of organic matter in water samples were also determined to study the transformation of organic matter during these advanced treatments. Low-molecular-weight matter was the predominant fraction in raw water, and it could not be removed effectively by ultrafiltration and biofiltration. The dominant species of disinfection by-product formation potential (DBPFP) in raw water were chloroform and monochloroacetic acid (MCAA), with average concentrations of 107.3 and 125.9 μg/L, respectively. However, the formation potential of chloroform and MCAA decreased to 36.2 and 11.5 μg/L after ultrafiltration. Similarly, biological pretreatment obtained high removal efficiency for DBPFP. The total THMFP decreased from 173.8 to 81.8 μg/L, and the total HAAFP decreased from 211.9 to 84.2 μg/L. Separate ozonation had an adverse effect on DBPFP, especially for chlorinated HAAFP. Numerous low-molecular-weight compounds such as aldehydes, ketones, and alcohols were generated during the ozonation, which have been proven to be important precursors of HAAs. However, the ozonation/biological activated carbon (BAC) combined process had a better removal efficiency for DBPFP. The total DBPFP decreased remarkably from 338.7 to 113.3 μg/L after the O3/BAC process, far below the separated BAC of process B (189.1 μg/L). PMID:27180835

  7. Effect of aluminum speciation on fouling mechanisms by pre-coagulation/ultrafiltration process with different NOM fractions.

    PubMed

    Sun, Weiguang; Nan, Jun; Yao, Meng; Xing, Jia; Tian, Jiayu

    2016-09-01

    Ultrafiltration is an emerging technology for drinking water production, but the membrane fouling is still a challenge. This study was carried out to investigate the effect of aluminum speciation on UF membrane fouling behavior by different NOM fractions-humic substances and proteins, as represented by humic acid (HA) and bovine serum albumin (BSA), respectively. The interesting results showed that the total fouling resistance of the mixture of HA-BSA-kaolinite solution without coagulant demonstrated a slight decrease in comparison with those of the individually filtered substances, indicating a mitigatory fouling effect. The hydrolysis of aluminum products was various as pH and membrane fouling was related to aluminum speciation. The average size of flocs dramatically increased and fractal dimension of flocs decreased with the increasing of pH value independent on water quality, which indicated that aluminum speciation had a significant impact on floc properties. For the mixture of HA-BSA-kaolinte, the slightly larger of flocs average size in comparison with the individual organic fraction after coagulation was probably attributing that BSA was encapsulated by HA to enlarge the molecular length and floc size further increased. The membrane performance also showed that coagulation effluent of HA-BSA-kaolinite mitigated membrane fouling. The strong linear relationship was observed between flocs fractal dimension and final membrane flux in this research. From the results, the control of flocs fractal dimension should be considered as a new technique for traditional hybrid coagulation/ultrafiltration system, which resulted in minimized total and irreversible fouling and has a meaningful engineering application value. PMID:27230150

  8. Ultrafiltration and Microarray for Detection of Microbial Source Tracking Marker and Pathogen Genes in Riverine and Marine Systems

    PubMed Central

    Li, Xiang; Harwood, Valerie J.; Nayak, Bina

    2016-01-01

    Pathogen identification and microbial source tracking (MST) to identify sources of fecal pollution improve evaluation of water quality. They contribute to improved assessment of human health risks and remediation of pollution sources. An MST microarray was used to simultaneously detect genes for multiple pathogens and indicators of fecal pollution in freshwater, marine water, sewage-contaminated freshwater and marine water, and treated wastewater. Dead-end ultrafiltration (DEUF) was used to concentrate organisms from water samples, yielding a recovery efficiency of >95% for Escherichia coli and human polyomavirus. Whole-genome amplification (WGA) increased gene copies from ultrafiltered samples and increased the sensitivity of the microarray. Viruses (adenovirus, bocavirus, hepatitis A virus, and human polyomaviruses) were detected in sewage-contaminated samples. Pathogens such as Legionella pneumophila, Shigella flexneri, and Campylobacter fetus were detected along with genes conferring resistance to aminoglycosides, beta-lactams, and tetracycline. Nonmetric dimensional analysis of MST marker genes grouped sewage-spiked freshwater and marine samples with sewage and apart from other fecal sources. The sensitivity (percent true positives) of the microarray probes for gene targets anticipated in sewage was 51 to 57% and was lower than the specificity (percent true negatives; 79 to 81%). A linear relationship between gene copies determined by quantitative PCR and microarray fluorescence was found, indicating the semiquantitative nature of the MST microarray. These results indicate that ultrafiltration coupled with WGA provides sufficient nucleic acids for detection of viruses, bacteria, protozoa, and antibiotic resistance genes by the microarray in applications ranging from beach monitoring to risk assessment. PMID:26729716

  9. Effect of coagulation on fouling potential and removal of algal organic matter in ultrafiltration pretreatment to seawater reverse osmosis.

    PubMed

    Alizadeh Tabatabai, S Assiyeh; Schippers, Jan C; Kennedy, Maria D

    2014-08-01

    This paper investigated the effect of coagulation on fouling potential and removal of algal organic matter (AOM) in seawater ultrafiltration (UF) systems. AOM harvested from a strain of bloom forming marine diatom, Chaetoceros affinis, was coagulated with ferric chloride under different coagulation modes and conditions. The effect of coagulation on fouling potential was determined with the Modified Fouling Index-Ultrafiltration (MFI-UF). Removal of AOM was studied for three different modes of coagulation, namely, coagulation followed by sedimentation, coagulation followed by sedimentation and filtration through 0.45 μm, and inline coagulation followed by filtration through 150 kDa UF membranes. Liquid chromatography - organic carbon detection was used to determine the removal of AOM with particular emphasis on biopolymers. AOM (as biopolymers) had a high fouling potential as measured by MFI-UF, which strongly depended on filtration flux. Moreover, the developed cake/gel layer on the membrane was fairly compressible during filtration; manifested as higher fouling potential at higher filtration flux and non-linear development of pressure in filtration tests. Coagulation substantially reduced fouling potential and compressibility of the AOM cake/gel layer. The impact of coagulation was particularly significant at coagulant doses >1 mg Fe/L. Coagulation also substantially reduced the flux-dependency of AOM fouling potential, resulting in linear development of pressure in filtration tests at constant flux. This was attributed to adsorption of biopolymers on precipitated iron hydroxide and formation of Fe-biopolymer aggregates, such that the fouling characteristics of iron hydroxide precipitates prevailed and AOM fouling characteristics diminished. At low coagulant dose, inline coagulation/UF was more effective in removing AOM than the other two coagulation modes tested. At high coagulant dose where sweep floc conditions prevailed, AOM removal was considerably higher

  10. Meta-Analysis of Ultrafiltration versus Diuretics Treatment Option for Overload Volume Reduction in Patients with Acute Decompensated Heart Failure

    PubMed Central

    Barkoudah, Ebrahim; Kodali, Sindhura; Okoroh, Juliet; Sethi, Rosh; Hulten, Edward; Suemoto, Claudia; Bittencourt, Marcio Sommer

    2015-01-01

    Introduction Although diuretics are mainly used for the treatment of acute decompensated heart failure (ADHF), inadequate responses and complications have led to the use of extracorporeal ultrafiltration (UF) as an alternative strategy for reducing volume overloads in patients with ADHF. Objective The aim of our study is to perform meta-analysis of the results obtained from studies on extracorporeal venous ultrafiltration and compare them with those of standard diuretic treatment for overload volume reduction in acute decompensated heart failure. Methods MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials databases were systematically searched using a pre‑specified criterion. Pooled estimates of outcomes after 48 h (weight change, serum creatinine level, and all-cause mortality) were computed using random effect models. Pooled weighted mean differences were calculated for weight loss and change in creatinine level, whereas a pooled risk ratio was used for the analysis of binary all-cause mortality outcome. Results A total of nine studies, involving 613 patients, met the eligibility criteria. The mean weight loss in patients who underwent UF therapy was 1.78 kg [95% Confidence Interval (CI): −2.65 to −0.91 kg; p < 0.001) more than those who received standard diuretic therapy. The post-intervention creatinine level, however, was not significantly different (mean change = −0.25 mg/dL; 95% CI: −0.56 to 0.06 mg/dL; p = 0.112). The risk of all-cause mortality persisted in patients treated with UF compared with patients treated with standard diuretics (Pooled RR = 1.00; 95% CI: 0.64–1.56; p = 0.993). Conclusion Compared with standard diuretic therapy, UF treatment for overload volume reduction in individuals suffering from ADHF, resulted in significant reduction of body weight within 48 h. However, no significant decrease of serum creatinine level or reduction of all-cause mortality was observed. PMID:25626761

  11. Effect of ultrafiltration process on physico-chemical, rheological, microstructure and thermal properties of syrups from male and female date palm saps.

    PubMed

    Makhlouf-Gafsi, Ines; Baklouti, Samia; Mokni, Abir; Danthine, Sabine; Attia, Hamadi; Blecker, Christophe; Besbes, Souhail; Masmoudi, Manel

    2016-07-15

    This study investigates the effect of the ultrafiltration process on physicochemical, rheological, microstructure and thermal properties of syrups from male and female date palm sap. All the studied syrups switched from pseudoplastic rheological behaviour (n=0.783) to Newtonian behaviour (n∼1) from 10 to 50 °C respectively and present similar thermal profiles. Results revealed that the ultrafiltration process significantly affects the rheological behaviour of the male and female syrups. These differences on rheological properties are attributed to the variation of chemical composition between sap and sap permeate syrups. Furthermore, the effect of temperature on viscosity of the syrups was investigated during heating and cooling processes at the same shear rate (50s(-1)). This study provides idea of the stability of the syrup by evaluating the area between heating and cooling curves. Actually, the syrup prepared from male sap permeate is the most stable between the four studied syrups. PMID:26948603

  12. Ultrafiltration of skimmed goat milk increases its nutritional value by concentrating nonfat solids such as proteins, Ca, P, Mg, and Zn.

    PubMed

    Moreno-Montoro, Miriam; Olalla, Manuel; Giménez-Martínez, Rafael; Bergillos-Meca, Triana; Ruiz-López, María Dolores; Cabrera-Vique, Carmen; Artacho, Reyes; Navarro-Alarcón, Miguel

    2015-11-01

    Goat milk has been reported to possess good nutritional and health-promoting properties. Usually, it must be concentrated before fermented products can be obtained. The aim of this study was to compare physicochemical and nutritional variables among raw (RM), skimmed (SM), and ultrafiltration-concentrated skimmed (UFM) goat milk. The density, acidity, ash, protein, casein, whey protein, Ca, P, Mg, and Zn values were significantly higher in UFM than in RM or SM. Dry extract and fat levels were significantly higher in UFM than in SM, and Mg content was significantly higher in UFM than in RM. Ultrafiltration also increased the solubility of Ca and Mg, changing their distribution in the milk. The higher concentrations of minerals and proteins, especially caseins, increase the nutritional value of UFM, which may therefore be more appropriate for goat milk yogurt manufacturing in comparison to RM or SM. PMID:26342988

  13. Effect of ultrafiltration process on physico-chemical, rheological, microstructure and thermal properties of syrups from male and female date palm saps.

    PubMed

    Makhlouf-Gafsi, Ines; Baklouti, Samia; Mokni, Abir; Danthine, Sabine; Attia, Hamadi; Blecker, Christophe; Besbes, Souhail; Masmoudi, Manel

    2016-07-15

    This study investigates the effect of the ultrafiltration process on physicochemical, rheological, microstructure and thermal properties of syrups from male and female date palm sap. All the studied syrups switched from pseudoplastic rheological behaviour (n=0.783) to Newtonian behaviour (n∼1) from 10 to 50 °C respectively and present similar thermal profiles. Results revealed that the ultrafiltration process significantly affects the rheological behaviour of the male and female syrups. These differences on rheological properties are attributed to the variation of chemical composition between sap and sap permeate syrups. Furthermore, the effect of temperature on viscosity of the syrups was investigated during heating and cooling processes at the same shear rate (50s(-1)). This study provides idea of the stability of the syrup by evaluating the area between heating and cooling curves. Actually, the syrup prepared from male sap permeate is the most stable between the four studied syrups.

  14. Presence of biofilms on ultrafiltration membrane surfaces increases the quality of permeate produced during ultra-low pressure gravity-driven membrane filtration.

    PubMed

    Derlon, Nicolas; Mimoso, Joao; Klein, Theresa; Koetzsch, Stefan; Morgenroth, Eberhard

    2014-09-01

    This study evaluates the effect of the presence of biofilms on membrane surfaces on the quality of permeate produced during Gravity-driven membrane ultrafiltration. GDM ultrafiltration is applied to the decentralized production of drinking water. A second objective was to evaluate to what extent permeate quality is enhanced by pre-treating feed-water (using a packed bed biofilm reactor or a slow sand filter). The influence of the ageing of the biofilm on the permeate quality was evaluated and compared to the effect of virgin membranes. Permeate quality was evaluated in terms of Assimilable Organic Carbon (AOC) content and dissolved organic carbon fractions (e.g. biopolymers). Our results indicate that virgin ultrafiltration membrane remove a small fraction of the AOC and biopolymers (rejection <10%). The presence of a young and thin biofilm on the surface of the ultrafiltration membranes increases the permeate quality due to the degradation of AOC (>80%). However, over long-term the hydrolysis of the organic matter that accumulated on membrane surfaces increases the AOC content of the permeate, thus deteriorating the permeate quality. Pre-treatment of the feed-water help to control the biofilm accumulation and thus to limit the deterioration of the permeate quality. Permeate flux stabilised at average values of 7.5-8.9 L m(-2) h(-1). But the presence of pre-treatment helped to increase permeate flux (+12 and 19%, with the packed bed biofilm reactor and with the slow sand filter, respectively). Overall our study demonstrates that tolerating the presence of biofilm on membrane surface has a beneficial effect on the quality of permeate even if its quantity is decreased.

  15. Impacts of epichlorohydrin-dimethylamine on coagulation performance and membrane fouling in coagulation/ultrafiltration combined process with different Al-based coagulants.

    PubMed

    Bu, Fan; Gao, Baoyu; Li, Ruihua; Sun, Shenglei; Yue, Qinyan

    2016-09-01

    Two kinds of aluminum-based coagulants and epichlorohydrin-dimethylamine (DAM-ECH) were used in the treatment of humic acid-kaolin simulated water by coagulation-ultrafiltration (C-UF) hybrid process. Coagulation performance, floc characteristics, including floc size, compact degree, and strength were investigated in this study. Ultrafiltration experiments were conducted by a dead-end batch unit to implement the resistance analyses to explore the membrane fouling mechanisms. Results showed that DAM-ECH aid significantly increased the UV254 and DOC removal efficiencies and contributed to the formation of larger and stronger flocs with a looser structure. Aluminum chloride (Al) gave rise to better coagulation performance with DAM-ECH compared with poly aluminum chloride (PACl). The consequences of ultrafiltration experiments showed that DAM-ECH aid could reduce the membrane fouling mainly by decreasing the cake layer resistance. The flux reductions for PACl, Al/DAM-ECH (dosing both Al and DAM-ECH) and PACl/DAM-ECH (dosing both PACl and DAM-ECH) were 62%, 56% and 44%, respectively. Results of this study would be beneficial for the application of PACl/DAM-ECH and Al/DAM-ECH composite coagulants in water treatment processes.

  16. Comparison of epichlorohydrin-dimethylamine with other cationic organic polymers as coagulation aids of polyferric chloride in coagulation-ultrafiltration process.

    PubMed

    Sun, Shenglei; Gao, Baoyu; Yue, Qinyan; Li, Ruihua; Song, Wen; Bu, Fan; Zhao, Shuang; Jia, Ruibao; Song, Wuchang

    2016-04-15

    Epichlorohydrin-dimethylamine (DAM-ECH) copolymer was acquired by polycondensation of hazardous reagents: epichlorohydrin (analytical reagent, A.R.) and dimethylamine (A.R.) with ethanediamine (A.R.) as cross-linker. Its coagulation and membrane performance as coagulation aid of polyferric chloride (PFC) was evaluated by comparing with other two cationic coagulation aids: poly dimethyl diallyl ammonium chloride (PDMDAAC) and polyacrylamide (PAM) in humic acid-kaolin (HA-Kaolin) simulated water treatment. Firstly, optimum dosages of PFC&DAM-ECH, PFC&PDMDAAC and PFC&PAM were identified according to their coagulation performance. Then their impacts (under optimum dosages) on membrane fouling of regenerated cellulose (RC) ultra-membrane disc in coagulation-ultrafiltration (C-UF) process were reviewed. Results revealed that small addition of DAM-ECH was the effective on turbidity and DOC removal polymer. Furthermore, in the following ultra-filtration process, external membrane fouling resistance was demonstrated to be the dominant portion of the total membrane fouling resistance under all circumstances. Meanwhile, the internal membrane fouling resistance was determined by residual of micro-particles(1) that cannot be intercepted by cake layer or ultrafiltration membrane.

  17. Impacts of epichlorohydrin-dimethylamine on coagulation performance and membrane fouling in coagulation/ultrafiltration combined process with different Al-based coagulants.

    PubMed

    Bu, Fan; Gao, Baoyu; Li, Ruihua; Sun, Shenglei; Yue, Qinyan

    2016-09-01

    Two kinds of aluminum-based coagulants and epichlorohydrin-dimethylamine (DAM-ECH) were used in the treatment of humic acid-kaolin simulated water by coagulation-ultrafiltration (C-UF) hybrid process. Coagulation performance, floc characteristics, including floc size, compact degree, and strength were investigated in this study. Ultrafiltration experiments were conducted by a dead-end batch unit to implement the resistance analyses to explore the membrane fouling mechanisms. Results showed that DAM-ECH aid significantly increased the UV254 and DOC removal efficiencies and contributed to the formation of larger and stronger flocs with a looser structure. Aluminum chloride (Al) gave rise to better coagulation performance with DAM-ECH compared with poly aluminum chloride (PACl). The consequences of ultrafiltration experiments showed that DAM-ECH aid could reduce the membrane fouling mainly by decreasing the cake layer resistance. The flux reductions for PACl, Al/DAM-ECH (dosing both Al and DAM-ECH) and PACl/DAM-ECH (dosing both PACl and DAM-ECH) were 62%, 56% and 44%, respectively. Results of this study would be beneficial for the application of PACl/DAM-ECH and Al/DAM-ECH composite coagulants in water treatment processes. PMID:27295439

  18. Controlling Legionella and Pseudomonas aeruginosa re-growth in therapeutic spas: implementation of physical disinfection treatments, including UV/ultrafiltration, in a respiratory hydrotherapy system.

    PubMed

    Leoni, E; Sanna, T; Zanetti, F; Dallolio, L

    2015-12-01

    The study aimed to assess the efficacy of an integrated water safety plan (WSP) in controlling Legionella re-growth in a respiratory hydrotherapy system located in a spa centre, supplied with sulphurous water, which was initially colonized by Legionella pneumophila. Heterotrophic plate counts, Pseudomonas aeruginosa, Legionella spp. were detected in water samples taken 6-monthly from the hydrotherapy equipment (main circuit, entry to benches, final outlets). On the basis of the results obtained by the continuous monitoring and the changes in conditions, the original WSP, including physical treatments of water and waterlines, environmental surveillance and microbiological monitoring, was integrated introducing a UV/ultrafiltration system. The integrated treatment applied to the sulphurous water (microfiltration/UV irradiation/ultrafiltration), waterlines (superheated stream) and distal outlets (descaling/disinfection of nebulizers and nasal irrigators), ensured the removal of Legionella spp. and P. aeruginosa and a satisfactory microbiological quality over time. The environmental surveillance was successful in evaluating the hazard and identifying the most suitable preventive strategies to avoid Legionella re-growth. Ultrafiltration is a technology to take into account in the control of microbial contamination of therapeutic spas, since it does not modify the chemical composition of the water, thus allowing it to retain its therapeutic properties. PMID:26608761

  19. Controlling Legionella and Pseudomonas aeruginosa re-growth in therapeutic spas: implementation of physical disinfection treatments, including UV/ultrafiltration, in a respiratory hydrotherapy system.

    PubMed

    Leoni, E; Sanna, T; Zanetti, F; Dallolio, L

    2015-12-01

    The study aimed to assess the efficacy of an integrated water safety plan (WSP) in controlling Legionella re-growth in a respiratory hydrotherapy system located in a spa centre, supplied with sulphurous water, which was initially colonized by Legionella pneumophila. Heterotrophic plate counts, Pseudomonas aeruginosa, Legionella spp. were detected in water samples taken 6-monthly from the hydrotherapy equipment (main circuit, entry to benches, final outlets). On the basis of the results obtained by the continuous monitoring and the changes in conditions, the original WSP, including physical treatments of water and waterlines, environmental surveillance and microbiological monitoring, was integrated introducing a UV/ultrafiltration system. The integrated treatment applied to the sulphurous water (microfiltration/UV irradiation/ultrafiltration), waterlines (superheated stream) and distal outlets (descaling/disinfection of nebulizers and nasal irrigators), ensured the removal of Legionella spp. and P. aeruginosa and a satisfactory microbiological quality over time. The environmental surveillance was successful in evaluating the hazard and identifying the most suitable preventive strategies to avoid Legionella re-growth. Ultrafiltration is a technology to take into account in the control of microbial contamination of therapeutic spas, since it does not modify the chemical composition of the water, thus allowing it to retain its therapeutic properties.

  20. Comparison of epichlorohydrin-dimethylamine with other cationic organic polymers as coagulation aids of polyferric chloride in coagulation-ultrafiltration process.

    PubMed

    Sun, Shenglei; Gao, Baoyu; Yue, Qinyan; Li, Ruihua; Song, Wen; Bu, Fan; Zhao, Shuang; Jia, Ruibao; Song, Wuchang

    2016-04-15

    Epichlorohydrin-dimethylamine (DAM-ECH) copolymer was acquired by polycondensation of hazardous reagents: epichlorohydrin (analytical reagent, A.R.) and dimethylamine (A.R.) with ethanediamine (A.R.) as cross-linker. Its coagulation and membrane performance as coagulation aid of polyferric chloride (PFC) was evaluated by comparing with other two cationic coagulation aids: poly dimethyl diallyl ammonium chloride (PDMDAAC) and polyacrylamide (PAM) in humic acid-kaolin (HA-Kaolin) simulated water treatment. Firstly, optimum dosages of PFC&DAM-ECH, PFC&PDMDAAC and PFC&PAM were identified according to their coagulation performance. Then their impacts (under optimum dosages) on membrane fouling of regenerated cellulose (RC) ultra-membrane disc in coagulation-ultrafiltration (C-UF) process were reviewed. Results revealed that small addition of DAM-ECH was the effective on turbidity and DOC removal polymer. Furthermore, in the following ultra-filtration process, external membrane fouling resistance was demonstrated to be the dominant portion of the total membrane fouling resistance under all circumstances. Meanwhile, the internal membrane fouling resistance was determined by residual of micro-particles(1) that cannot be intercepted by cake layer or ultrafiltration membrane. PMID:26775103

  1. Preparative isolation and analysis of alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root using ultrafiltration combined with high-performance liquid chromatography and high-speed countercurrent chromatography.

    PubMed

    Chen, Miao; Liu, Liangliang; Chen, Xiaoqing

    2014-07-01

    A simple, rapid, and effective assay based on ultrafiltration combined with high-performance liquid chromatography and high-speed countercurrent chromatography was developed for screening and purifying alcohol dehydrogenase inhibitors from Glycyrrhiza uralensis root extract. Experiments were carried out to optimize binding conditions including alcohol dehydrogenase concentration, incubation time, temperature, and pH. By comparing the chromatograms, three compounds were found possessing alcohol dehydrogenase binding activity in Glycyrrhiza uralensis root. Under the target-guidance of ultrafiltration combined with the high-performance liquid chromatography experiment, liquiritin (1), isoliquiritin (2), and liquiritigenin (3) were separated by high-speed countercurrent chromatography using ethyl acetate/methanol/water (5:1:4) as the solvent system. The alcohol dehydrogenase inhibitory activities of these three isolated compounds were assessed; compound 2 showed strongest inhibitory activity with an IC50 of 8.95 μM. The results of the present study indicated that the combinative method using ultrafiltration, high-performance liquid chromatography and high-speed countercurrent chromatography could be widely applied for the rapid screening and isolation of enzyme inhibitors from complex mixtures.

  2. Evaluation of synthetic water-soluble metal-binding polymers with ultrafiltration for selective concentration of americium and plutonium

    SciTech Connect

    Smith, B.F.; Gibson, R.R.; Jarvinen, G.D.; Jones, M.M.; Lu, M.T.; Robison, T.W.; Schroeder, N.C.; Stalnaker, N.

    1997-12-31

    Routine counting methods and ICP-MS are unable to directly measure the new US Department of Energy (DOE) regulatory level for discharge waters containing alpha-emitting radionuclides of 30 pCi/L total alpha or the 0.05 pCi/L regulatory level for Pu or Am activity required for surface waters at the Rocky Flats site by the State of Colorado. This inability indicates the need to develop rapid, reliable, and robust analytical techniques for measuring actinide metal ions, particularly americium and plutonium. Selective separation or preconcentration techniques would aid in this effort. Water-soluble metal-binding polymers in combination with ultrafiltration are shown to be an effective method for selectively removing dilute actinide ions from acidic solutions of high ionic strength. The actinide-binding properties of commercially available water-soluble polymers and several polymers which have been reported in the literature were evaluated. The functional groups incorporated in the polymers were pyrrolidone, amine, oxime, and carboxylic, phosphonic, or sulfonic acid. The polymer containing phosphonic acid groups gave the best results with high distribution coefficients and concentration factors for {sup 241}Am(III) and {sup 238}Pu(III)/(IV) at pH 4 to 6 and ionic strengths of 0.1 to 4.

  3. Polyaniline-Coated Carbon Nanotube Ultrafiltration Membranes: Enhanced Anodic Stability for In Situ Cleaning and Electro-Oxidation Processes.

    PubMed

    Duan, Wenyan; Ronen, Avner; Walker, Sharon; Jassby, David

    2016-08-31

    Electrically conducting membranes (ECMs) have been reported to be efficient in fouling prevention and destruction of aqueous chemical compounds. In the current study, highly conductive and anodically stable composite polyaniline-carbon nanotube (PANI-CNT) ultrafiltration (UF) ECMs were fabricated through a process of electropolymerization of aniline on a CNT substrate under acidic conditions. The resulting PANI-CNT UF ECMs were characterized by scanning electron microscopy, atomic force microscopy, a four-point conductivity probe, cyclic voltammetry, and contact angle goniometry. The utilization of the PANI-CNT material led to significant advantages, including: (1) increased electrical conductivity by nearly an order of magnitude; (2) increased surface hydrophilicity while not impacting membrane selectivity or permeability; and (3) greatly improved stability under anodic conditions. The membrane's anodic stability was evaluated in a pH-controlled aqueous environment under a wide range of anodic potentials using a three-electrode cell. Results indicate a significantly reduced degradation rate in comparison to a CNT-poly(vinyl alcohol) ECM under high anodic potentials. Fouling experiments conducted with bovine serum albumin demonstrated the capacity of the PANI-CNT ECMs for in situ oxidative cleaning, with membrane flux restored to its initial value under an applied potential of 3 V. Additionally, a model organic compound (methylene blue) was electrochemically transformed at high efficiency (90%) in a single pass through the anodically charged ECM. PMID:27525344

  4. Microalgae recovery by ultrafiltration using novel fouling-resistant PVDF membranes with in situ PEGylated polyethyleneimine particles.

    PubMed

    Hwang, Taewoon; Kotte, Madhusudhana Rao; Han, Jong-In; Oh, You-Kwan; Diallo, Mamadou S

    2015-04-15

    In this article, we report the preparation, characterization and microalgae recovery potential of a new family of fouling-resistant polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes embedded with hydrophilic and PEGylated polymeric particles. To optimize membrane performance for microalgae harvesting, we investigate the effects of three hydrophilic additives (Pluronic F-127, polyvinylpyrrolidone and polyethylene glycol) on the morphology, pore size, bulk composition, surface composition, wettability and surface charge, flux and fouling resistance of the mixed matrix PVDF membranes with in situ PEGylated polyethyleneimine (PEI) particles. Our filtration experiments show that a mixed matrix PVDF membrane with PEGylated PEI particles and Pluronic F-127 additive (PNSM-1) has an algae retention of 100% with a permeate flux of 96 L/m(2)/hr that is larger (by ∼50%) than that of a commercial and hydrophilic PVDF UF membrane with a molecular weight cut-off of 30 kDa using a suspension of Chlorella sp. KR-1 microalgae with 1.2-1.4 g/L of dry biomass. The algae and water flux recovery rates of our new PNSM-1 are equal to∼ 94% and 100%, respectively, following a simulated membrane wash with deionized water and two subsequent water and microalgae filtration cycles.

  5. Preparation and characterization of a novel PVDF ultrafiltration membrane by blending with TiO2-HNTs nanocomposites

    NASA Astrophysics Data System (ADS)

    Zeng, Guangyong; He, Yi; Yu, Zongxue; Zhan, Yingqing; Ma, Lan; Zhang, Lei

    2016-05-01

    Novel polyvinylidene fluoride (PVDF) ultrafiltration membranes were prepared by blending with different contents of titanium dioxide-halloysite nanotubes (TiO2-HNTs) composites into the PVDF matrix. The effects of TiO2-HNTs content on the membrane performances, such as hydrophilicity, rejection ratio and antifouling properties were investigated in detail. X-ray diffraction (XRD), thermo-gravimetric analyzer (TGA) and scanning electron microscope (SEM) analyses showed that TiO2 was loaded on the surface of HNTs successfully and homogeneously by sol-gel method. The morphologies and microstructure of the membranes were characterized by SEM and atomic force microscopy (AFM). The contact angle (CA) tests indicated that the hydrophilicity of membranes was significantly increased with the addition of TiO2-HNTs. The pure water flux of 3%TiO2-HNTs/PVDF was increased by 264.8% and 35.6%, respectively, compared with pure PVDF membrane and 3%TiO2/PVDF membrane, although the rejection of bovine serum albumin (BSA) was slightly decreased. More importantly, TiO2-HNTs/PVDF membrane exhibited an excellent anti-fouling performance, which was attributed to the hydrophobic contaminants being resisted by hydrophilic nanoparticles. It can be expected that this work may provide some references to solve the dispersion of nanoparticle in the membrane and improve the anti-fouling performance of membrane in the field of wastewater treatment.

  6. Membrane flux dynamics in the submerged ultrafiltration hybrid treatment process during particle and natural organic matter removal.

    PubMed

    Zhang, Wei; Zhang, Xiaojian; Li, Yonghong; Wang, Jun; Chen, Chao

    2011-01-01

    Particles and natural organic matter (NOM) are two major concerns in surface water, which greatly influence the membrane filtration process. The objective of this article is to investigate the effect of particles, NOM and their interaction on the submerged ultrafiltration (UF) membrane flux under conditions of solo UF and coagulation and PAC adsorption as the pretreatment of UF. Particles, NOM and their mixture were spiked in tap water to simulate raw water. Exponential relationship, (J(P)/J(P0) = a x exp{-k[t-(n-1)T]}), was developed to quantify the normalized membrane flux dynamics during the filtration period and fitted the results well. In this equation, coefficient a was determined by the value of J(P)/J(P0) at the beginning of a filtration cycle, reflecting the flux recovery after backwashing, that is, the irreversible fouling. The coefficient k reflected the trend of flux dynamics. Integrated total permeability (SigmaJ(P)) in one filtration period could be used as a quantified indicator for comparison of different hybrid membrane processes or under different scenarios. According to the results, there was an additive effect on membrane flux by NOM and particles during solo UF process. This additive fouling could be alleviated by coagulation pretreatment since particles helped the formation of flocs with coagulant, which further delayed the decrease of membrane flux and benefited flux recovery by backwashing. The addition of PAC also increased membrane flux by adsorbing NOM and improved flux recovery through backwashing. PMID:22432326

  7. Integrated membrane systems incorporating coagulation, activated carbon and ultrafiltration for the removal of toxic cyanobacterial metabolites from Anabaena circinalis.

    PubMed

    Dixon, M B; Richard, Y; Ho, L; Chow, C W K; O'Neill, B K; Newcombe, G

    2011-01-01

    The use of integrated membrane systems (a train of treatment processes incorporating one or more membranes) is increasing globally as the technology is very effective for the production of high quality drinking water. In this investigation a laboratory scale integrated membrane system (IMS) featuring coagulation, powdered activated carbon (PAC) and ultrafiltration (UF) was investigated for the removal of an Australian strain of the cyanobacteria Anabaena circinalis and the cyanotoxin it produced. Three coagulants were compared, aluminium chlorohydrate (ACH), aluminium sulphate (alum) and an engineered aluminium coagulant referred to as high performance aluminium chlorohydrate (HPAC). PAC (Acticarb PS1000) was tested to determine adsorption of extracellular saxitoxin. Removal of A. circinalis cells was 100% by UF alone and the removal of cells prior to the membrane by coagulation reduced fouling attributed to algogenic organic material. Alum was the least efficient coagulant for removal of cells while ACH and HPAC were similar. Saxitoxin removal reached a maximum of 80% using ACH and PAC. The UF-IMS was challenged using a natural bloom of A. circinalis that occurred in the Myponga Reservoir in South Australia. PMID:21508543

  8. Evaluation of hollow-fiber ultrafiltration primary concentration of pathogens and secondary concentration of viruses from water.

    PubMed

    Rhodes, Eric R; Hamilton, Douglas W; See, Mary Jean; Wymer, Larry

    2011-09-01

    Tangential flow hollow-fiber ultrafiltration (HFUF) was evaluated for virus and Cryptosporidium parvum concentration from water. Recovery of viruses at a low filtration rate was found to be significantly greater than at a higher filtration rate, with the recoveries of bacteriophage MS2 at high and low filtration rates shown to be 64.7% and 98.7%, respectively. Poliovirus recoveries from tap water were similar to MS2, with recoveries of 62.9% and 104.5% for high and low filtration rates, respectively. C. parvum, which was only tested at high filtration rates, had an average recovery was 105.1%. In addition to the optimization of the primary concentration technique, this study also compared several secondary concentration procedures. The highest recovery (89.5%) of poliovirus from tap water concentrates was obtained when a beef extract-celite method was used and the virus was eluted from the celite with phosphate buffered saline, pH 9.0. When HFUF primary concentration and the optimal secondary concentration methods were combined, an average recovery of 97.0 ± 35.6% or 89.3 ± 19.3%, depending on spike level, was achieved for poliovirus. This study demonstrated that HFUF primary concentration method is effective at recovering MS2, poliovirus and C. parvum from large volumes of water and that beef extract-celite method is an effective secondary concentration method for the poliovirus tested.

  9. Continuous production of cyclodextrins in an ultrafiltration membrane reactor, catalyzed by cyclodextrin glycosyltransferase from Bacillus circulans DF 9R.

    PubMed

    Rodríguez Gastón, Jorgelina A; Costa, Hernán; Ferrarotti, Susana A

    2015-01-01

    Cyclodextrins (CDs) are cyclic oligosaccharides of wide industrial application, whose synthesis is catalyzed by Cyclodextrin glycosyltransferase (CGTase) from starch. Here, CDs were produced using CGTase from Bacillus circulans DF 9R in continuous process and an ultrafiltration membrane reactor. The batch process was conducted as a control. This method allowed increasing the yield from 40 to 55.6% and the productivity from 26.1 to 99.5 mg of CD per unit of enzyme. The method also allowed obtaining a high-purity product. The flow rate remained at 50% of its initial value after 24 h of process, improving the results described in the literature for starch hydrolysis processes. CGTase remained active throughout the process, which could be explained by the protective effect of the substrate and reaction products on CGTase stability. In addition, batch processes were developed using starches from different sources. We concluded that any of the starches studied could be used as substrate for CD production with similar yields and product specificity.

  10. Characterization of charge properties of an ultrafiltration membrane modified by surface grafting of poly(allylamine) hydrochloride.

    PubMed

    Dejeu, J; Lakard, B; Fievet, P; Lakard, S

    2009-05-01

    A polyethersulfone ultrafiltration membrane was functionalized by a cationic polyelectrolyte, the poly(allylamine) hydrochloride (PAH). The influence of the time of adsorption of PAH on the membrane charge properties was studied. Several characterization techniques were used to investigate the membrane modification. Tangential and transmembrane streaming potential measurements were conducted to characterize the outer and inner surfaces of the membrane, respectively. Both techniques indicated that the surface modification of the membrane was efficient. The charge of the outer surface was reversed (from negative values for the unmodified membrane to positive values for the modified membrane) and the charge of the inner surface was neutralized after adsorption of the cationic polyelectrolyte onto the pore walls. The modification of both the outer surface of the membrane and the pore walls was also put in evidence with membrane potential measurements. It was found that the charge of the PAH-modified membrane is affected by the time of immersion in PAH solution. Experimental data seem to show a fast modification of the membrane for the first 15 min; nevertheless, the modification was more pronounced after 24 h of PAH adsorption. Diffusion experiments carried out with unmodified and modified membranes for four salts (KCl, NaCl, MgCl, and CaCl(2)) showed a decrease in the salt permeability after functionalization of the membrane. The permeability decrease was greater for 2:1 salts than for 1:1 salts. This decrease was explained by electrostatic interactions. PMID:19215937

  11. Permeability-Selectivity Analysis of Microfiltration and Ultrafiltration Membranes: Effect of Pore Size and Shape Distribution and Membrane Stretching.

    PubMed

    Siddiqui, Muhammad Usama; Arif, Abul Fazal Muhammad; Bashmal, Salem

    2016-01-01

    We present a modeling approach to determine the permeability-selectivity tradeoff for microfiltration and ultrafiltration membranes with a distribution of pore sizes and pore shapes. Using the formulated permeability-selectivity model, the effect of pore aspect ratio and pore size distribution on the permeability-selectivity tradeoff of the membrane is analyzed. A finite element model is developed to study the effect of membrane stretching on the distribution of pore sizes and shapes in the stretched membrane. The effect of membrane stretching on the permeability-selectivity tradeoff of membranes is also analyzed. The results show that increasing pore aspect ratio improves membrane performance while increasing the width of pore size distribution deteriorates the performance. It was also found that the effect of membrane stretching on the permeability-selectivity tradeoff is greatly affected by the uniformity of pore distribution in the membrane. Stretching showed a positive shift in the permeability-selectivity tradeoff curve of membranes with well-dispersed pores while in the case of pore clustering, a negative shift in the permeability-selectivity tradeoff curve was observed. PMID:27509528

  12. Seasonal variation of organic matter concentration and characteristics in the Maji ya Chai River (Tanzania): Impact on treatability by ultrafiltration.

    PubMed

    Aschermann, Geert; Jeihanipour, Azam; Shen, Junjie; Mkongo, Godfrey; Dramas, Laure; Croué, Jean-Philippe; Schäfer, Andrea

    2016-09-15

    Many waters in Tanzania exhibit high concentrations of organic matter and dissolved contaminants such as fluoride. Due to bacteria and virus removal, ultrafiltration (UF) is an attractive option for drinking water treatment, and when coupled with adsorbents, may compete with other established processes like nanofiltration (NF) for lower contaminant concentrations. The results presented here examine the characteristics and treatability of tropical natural organic matter (NOM) by UF as a function of seasonal variation. The Tanzanian river Maji ya Chai was sampled monthly during one year. The composition of NOM in Maji ya Chai River is influenced strongly by precipitation. Total organic carbon (TOC), specific ultraviolet absorbance (SUVA) and concentration of allochthonous organics substances (such as humic substances (HS)) are elevated in periods following high precipitation, while TOC is lower and contains more biopolymers in the dry seasons. UF experiments with two regenerated cellulose membranes of different molecular weight cut-off (MWCO, 5 and 10 kDa) were conducted. UF is able to remove 50-95% of TOC with a seasonal variability of 10-20%. Due to the remaining NOM in the water that would contribute to disinfection by-product formation and bacterial regrowth, the physically disinfected water is more applicable for point of use systems than distribution or storage.

  13. Identification of lipopeptides in Bacillus megaterium by two-step ultrafiltration and LC-ESI-MS/MS.

    PubMed

    Ma, Yunxiao; Kong, Qing; Qin, Chong; Chen, Yulin; Chen, Yujie; Lv, Ruihuan; Zhou, Guanghui

    2016-12-01

    A two-step ultrafiltration and liquid chromatography-electronic spray ionization-tandem mass spectrometry (LC-ESI-MS/MS) were applied to investigate the nature of lipopeptides in the methanol extract harvested from marine Bacillus megaterium. The structure of lipopeptide homologs were characterized by using collision-induced dissociation mass spectrometry analysis. Collectively, two kinds of linear fengycin A and B with a double bond were characterized for the first time besides the popular cyclic fengycin A and B with the difference in the amino acid at position 6 of the peptide moiety. It is worth noting that two kinds of linear isoforms of surfactins and two kinds of cyclic isoforms of esperin with a smaller peptide ring formed by the fifth L-Asp and β-hydroxy fatty acid were also separated and identified in addition to the all seven kinds of cyclic isoforms of surfactins. Only one analogue (bacillomycin D) of iturin family was identified in this research. To our best knowledge, this is the first report that more than 40 variants of lipopeptides from one strain of Bacillus were identified using our potent purification and identification methods. PMID:27639854

  14. Effects of chemical sanitization using NaOH on the properties of polysulfone and polyethersulfone ultrafiltration membranes.

    PubMed

    Teella, Achyuta; Zydney, Andrew L; Zhou, Hongyi; Olsen, Cathryn; Robinson, Craig

    2015-01-01

    Membranes used in bioprocessing applications are typically sanitized before use to insure aseptic operation. However, there is almost no information in the literature on the effects of this preuse sanitization step on the properties of the membrane. Experiments were performed with commercially available hollow fiber polysulfone (PSf) and polyethersulfone (PES) membranes with different nominal molecular weight cutoffs. Data were obtained for the membrane hydraulic permeability, dextran retention coefficients, zeta potential (surface charge), and extent of protein adsorption both before and after sanitization with 0.5 N NaOH at 45°C for 30 min. Changes in chemical composition were examined using ATR-FT-IR and XPS. Sanitization caused a large increase in the net negative charge for all membranes. There was a small reduction in hydraulic permeability and a significant increase in dextran retention for the polyethersulfone membranes, consistent with a reduction in the effective pore size. Spectroscopic analyses suggest that this change is likely due to the base-catalyzed hydrolysis of the lactam ring in polyvinylpyrrolidone (PVP) that is typically is used as a wetting/pore-forming agent in PSf and PES membranes. Preuse sanitization also appeared to have a small effect on protein adsorption, although the extent of adsorption was quite low for both the virgin and sanitized membranes. The observed changes in membrane properties could have a significant impact on the ultrafiltration performance, demonstrating the importance of standardizing the sanitization procedures even in process development and scale-down validation studies. PMID:25367682

  15. Fouling propensity and separation efficiency of epoxidated polyethersulfone incorporated cellulose acetate ultrafiltration membrane in the retention of proteins

    NASA Astrophysics Data System (ADS)

    Jayalakshmi, A.; Rajesh, S.; Mohan, D.

    2012-10-01

    Epoxidated polyethersulfone (EPES) incorporated cellulose acetate (CA) ultrafiltration membranes were prepared by diffusion induced precipitation technique in the absence and presence of pore former polyethyleneglycol-600. Effect of blend ratio on the compatibility, thermal stability, mechanical strength, hydrophilicity, morphology, pure water flux, protein adsorption resistance, protein separation efficiency and fouling propensity of the CA/EPES blend membranes was evaluated. Addition of EPES results in the formation of thin separating layer and spongy sub layer in CA/EPES blend membranes. The efficiency of these membranes in the separation of commercially important proteins such as bovine serum albumin, egg albumin, pepsin and trypsin was studied and found to be enhanced as compared to CA membranes. The fouling-resistant capability of the membranes was studied by bovine serum albumin as the model foulant and flux recovery ratio of the membranes were calculated. Attempts have been made to correlate the changes in membrane morphology with pure water flux, hydraulic resistance, thermal and mechanical stability, separation efficiency and antifouling property of the CA/EPES membranes. The optimal combination of CA and EPES, thus allows the preparation of high performance UF membranes which are sufficiently dense to retain proteins and at the same time give economically viable fluxes.

  16. A coagulation-powdered activated carbon-ultrafiltration--multiple barrier approach for removing toxins from two Australian cyanobacterial blooms.

    PubMed

    Dixon, Mike B; Richard, Yann; Ho, Lionel; Chow, Christopher W K; O'Neill, Brian K; Newcombe, Gayle

    2011-02-28

    Cyanobacteria are a major problem for the world wide water industry as they can produce metabolites toxic to humans in addition to taste and odour compounds that make drinking water aesthetically displeasing. Removal of cyanobacterial toxins from drinking water is important to avoid serious illness in consumers. This objective can be confidently achieved through the application of the multiple barrier approach to drinking water quality and safety. In this study the use of a multiple barrier approach incorporating coagulation, powdered activated carbon (PAC) and ultrafiltration (UF) was investigated for the removal of intracellular and extracellular cyanobacterial toxins from two naturally occurring blooms in South Australia. Also investigated was the impact of these treatments on the UF flux. In this multibarrier approach, coagulation was used to remove the cells and thus the intracellular toxin while PAC was used for extracellular toxin adsorption and finally the UF was used for floc, PAC and cell removal. Cyanobacterial cells were completely removed using the UF membrane alone and when used in conjunction with coagulation. Extracellular toxins were removed to varying degrees by PAC addition. UF flux deteriorated dramatically during a trial with a very high cell concentration; however, the flux was improved by coagulation and PAC addition. PMID:21227576

  17. Comparison of traditional and molecular analytical methods for detecting biological agents in raw and drinking water following ultrafiltration

    USGS Publications Warehouse

    Francy, D.S.; Bushon, R.N.; Brady, A.M.G.; Bertke, E.E.; Kephart, C.M.; Likirdopulos, C.A.; Mailot, B.E.; Schaefer, F. W.; Lindquist, H.D. Alan

    2009-01-01

    Aims: To compare the performance of traditional methods to quantitative polymerase chain reaction (qPCR) for detecting five biological agents in large-volume drinking-water samples concentrated by ultrafiltration (UF). Methods and Results: Drinking-water samples (100 l) were seeded with Bacillus anthracis, Cryptospordium parvum, Francisella tularensis, Salmonella Typhi, and Vibrio cholerae and concentrated by UF. Recoveries by traditional methods were variable between samples and between some replicates; recoveries were not determined by qPCR. Francisella tularensis and V. cholerae were detected in all 14 samples after UF, B. anthracis was detected in 13, and C. parvum was detected in 9 out of 14 samples. Numbers found by qPCR after UF were significantly or nearly related to those found by traditional methods for all organisms except for C. parvum. A qPCR assay for S. Typhi was not available. Conclusions: qPCR can be used to rapidly detect biological agents after UF as well as traditional methods, but additional work is needed to improve qPCR assays for several biological agents, determine recoveries by qPCR, and expand the study to other areas. Significance and Impact of the Study: To our knowledge, this is the first study to compare the use of traditional and qPCR methods to detect biological agents in large-volume drinking-water samples. ?? 2009 The Society for Applied Microbiology.

  18. Molecular Mechanisms of Ultrafiltration Membrane Fouling in Polymer-Flooding Wastewater Treatment: Role of Ions in Polymeric Fouling.

    PubMed

    Liu, Guicai; Yu, Shuili; Yang, Haijun; Hu, Jun; Zhang, Yi; He, Bo; Li, Lei; Liu, Zhiyuan

    2016-02-01

    Polymer (i.e., anionic polyacrylamide (APAM)) fouling of polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes and its relationships to intermolecular interactions were investigated using atomic force microscopy (AFM). Distinct relations were obtained between the AFM force spectroscopy measurements and calculated fouling resistance over the concentration polarization layer (CPL) and gel layer (GL). The measured maximum adhesion forces (Fad,max) were closely correlated with the CPL resistance (Rp), and the proposed molecular packing property (largely based on the shape of AFM force spectroscopy curve) of the APAM chains was related to the GL resistance (Rg). Calcium ions (Ca(2+)) and sodium ions (Na(+)) caused more severe fouling. In the presence of Ca(2+), the large Rp corresponded to high foulant-foulant Fad,max, resulting in high flux loss. In addition, the Rg with Ca(2+) was minor, but the flux recovery rate after chemical cleaning was the lowest, indicating that Ca(2+) created more challenges in GL cleaning. With Na(+), the fouling behavior was complicated and concentration-dependent. The GL structures with Na(+), which might correspond to the proposed molecular packing states among APAM chains, played essential roles in membrane fouling and GL cleaning.

  19. Identification of lipopeptides in Bacillus megaterium by two-step ultrafiltration and LC-ESI-MS/MS.

    PubMed

    Ma, Yunxiao; Kong, Qing; Qin, Chong; Chen, Yulin; Chen, Yujie; Lv, Ruihuan; Zhou, Guanghui

    2016-12-01

    A two-step ultrafiltration and liquid chromatography-electronic spray ionization-tandem mass spectrometry (LC-ESI-MS/MS) were applied to investigate the nature of lipopeptides in the methanol extract harvested from marine Bacillus megaterium. The structure of lipopeptide homologs were characterized by using collision-induced dissociation mass spectrometry analysis. Collectively, two kinds of linear fengycin A and B with a double bond were characterized for the first time besides the popular cyclic fengycin A and B with the difference in the amino acid at position 6 of the peptide moiety. It is worth noting that two kinds of linear isoforms of surfactins and two kinds of cyclic isoforms of esperin with a smaller peptide ring formed by the fifth L-Asp and β-hydroxy fatty acid were also separated and identified in addition to the all seven kinds of cyclic isoforms of surfactins. Only one analogue (bacillomycin D) of iturin family was identified in this research. To our best knowledge, this is the first report that more than 40 variants of lipopeptides from one strain of Bacillus were identified using our potent purification and identification methods.

  20. The evaluation of hollow-fiber ultrafiltration and celite concentration of enteroviruses, adenoviruses and bacteriophage from different water matrices.

    PubMed

    Rhodes, Eric R; Huff, Emma M; Hamilton, Douglas W; Jones, Jenifer L

    2016-02-01

    The collection of waterborne pathogen occurrence data often requires the concentration of microbes from large volumes of water due to the low number of microorganisms that are typically present in environmental and drinking waters. Hollow-fiber ultrafiltration (HFUF) has shown promise in the recovery of various microorganisms. This study has demonstrated that the HFUF primary concentration method is effective at recovering bacteriophage φX174, poliovirus, enterovirus 70, echovirus 7, coxsackievirus B4 and adenovirus 41 from large volumes of tap and river water with an average recovery of all viruses of 73.4% and 81.0%, respectively. This study also evaluated an effective secondary concentration method using celite for the recovery of bacteriophage and enteric viruses tested from HFUF concentrates of both matrices. Overall, the complete concentration method (HFUF primary concentration plus celite secondary concentration) resulted in a concentration factor of 3333 and average recoveries for all viruses from tap and river waters of 60.6% and 60.0%, respectively.

  1. Contribution of Fe3O4 nanoparticles to the fouling of ultrafiltration with coagulation pre-treatment

    PubMed Central

    Yu, Wenzheng; Xu, Lei; Graham, Nigel; Qu, Jiuhui

    2015-01-01

    A coagulation (FeCl3)-ultrafiltration process was used to treat two different raw waters with/without the presence of Fe3O4 nanoparticle contaminants. The existence of Fe3O4 nanoparticles in the raw water was found to increase both irreversible and reversible membrane fouling. The trans-membrane pressure (TMP) increase was similar in the early stages of the membrane runs for both raw waters, while it increased rapidly after about 15 days in the raw water with Fe3O4 nanoparticles, suggesting the involvement of biological effects. Enhanced microbial activity with the presence of Fe3O4 nanoparticles was evident from the measured concentrations of extracellular polymeric substances (EPS) and deoxyribonucleic acid (DNA), and fluorescence intensities. It is speculated that Fe3O4 nanoparticles accumulated in the cake layer and increased bacterial growth. Associated with the bacterial growth is the production of EPS which enhances the bonding with, and between, the coagulant flocs; EPS together with smaller sizes of the nano-scale primary particles of the Fe3O4-CUF cake layer, led to the formation of a lower porosity, more resilient cake layer and membrane pore blockage. PMID:26268589

  2. Towards a better hydraulic cleaning strategy for ultrafiltration membrane fouling by humic acid: Effect of backwash water composition.

    PubMed

    Chang, Haiqing; Liang, Heng; Qu, Fangshu; Ma, Jun; Ren, Nanqi; Li, Guibai

    2016-05-01

    As a routine measurement to alleviate membrane fouling, hydraulic cleaning is of great significance for the steady operation of ultrafiltration (UF) systems in water treatment processes. In this work, a comparative study was performed to investigate the effects of the composition of backwash water on the hydraulic cleaning performance of UF membranes fouled by humic acid (HA). Various types of backwash water, including UF permeate, Milli-Q water, NaCl solution, CaCl2 solution and HA solution, were compared in terms of hydraulically irreversible fouling index, total surface tension and residual HA. The results indicated that Milli-Q water backwash was superior to UF permeate backwash in cleaning HA-fouled membranes, and the backwash water containing Na(+) or HA outperformed Milli-Q water in alleviating HA fouling. On the contrary, the presence of Ca(2+) in backwash water significantly decreased the backwash efficiency. Moreover, Ca(2+) played an important role in foulant removal, and the residual HA content closely related to the residual Ca(2+) content. Mechanism analysis suggested that the backwash process may involve fouling layer swelling, ion exchange, electric double layer release and competitive complexation. Ion exchange and competitive complexation played significant roles in the efficient hydraulic cleaning associated with Na(+) and HA, respectively.

  3. Rapid screening natural-origin lipase inhibitors from hypolipidemic decoctions by ultrafiltration combined with liquid chromatography-mass spectrometry.

    PubMed

    Xiao, Shun; Yu, Runru; Ai, Ni; Fan, Xiaohui

    2015-02-01

    Lipase inhibitors generate hypolipidemic effect that is helpful to control or treat some obesity diseases by inactivating catalytic activity of human pancreatic lipase, a key enzyme involved in triglyceride hydrolysis in vivo. Many traditional Chinese medicine (TCM) formulae have been effectively used to treat obesity and other fat related diseases for centuries and modern biological experiments demonstrate therapeutic effect of these formulae can be linked to their lipid-lowering capability in blood. These observations suggest that these hypolipidemic decoctions (HDs) could be a promising resource of natural-origin lipase inhibitors. This work described a rapid approach for screening lipase inhibitors from four widely used HDs, including Wu-Ling-San (WLS), Ze-Xie decoction (ZX), Xiao-Xian-Xiong decoction (XXX) and Xiao-Chai-Hu decoction (XCH), by ultrafiltration combing with high performance liquid chromatography-mass spectrometry (HPLC-MS). Our results showed sixteen natural-origin lipase inhibitors were discovered and identified by high resolution and multistage mass spectrometry. Inhibitory activities of two compounds were confirmed by a functional assay of lipase, which validated the reliability of our approach. Molecular docking simulation was then performed to investigate potential mechanism of action for these compounds. Together we present an efficient method for rapid screening lipase inhibitors from complex natural products, which can be easily accommodated to other important enzymatic system with therapeutic values.

  4. Contribution of Fe3O4 nanoparticles to the fouling of ultrafiltration with coagulation pre-treatment

    NASA Astrophysics Data System (ADS)

    Yu, Wenzheng; Xu, Lei; Graham, Nigel; Qu, Jiuhui

    2015-08-01

    A coagulation (FeCl3)-ultrafiltration process was used to treat two different raw waters with/without the presence of Fe3O4 nanoparticle contaminants. The existence of Fe3O4 nanoparticles in the raw water was found to increase both irreversible and reversible membrane fouling. The trans-membrane pressure (TMP) increase was similar in the early stages of the membrane runs for both raw waters, while it increased rapidly after about 15 days in the raw water with Fe3O4 nanoparticles, suggesting the involvement of biological effects. Enhanced microbial activity with the presence of Fe3O4 nanoparticles was evident from the measured concentrations of extracellular polymeric substances (EPS) and deoxyribonucleic acid (DNA), and fluorescence intensities. It is speculated that Fe3O4 nanoparticles accumulated in the cake layer and increased bacterial growth. Associated with the bacterial growth is the production of EPS which enhances the bonding with, and between, the coagulant flocs; EPS together with smaller sizes of the nano-scale primary particles of the Fe3O4-CUF cake layer, led to the formation of a lower porosity, more resilient cake layer and membrane pore blockage.

  5. Recovery of Whey Proteins and Enzymatic Hydrolysis of Lactose Derived from Casein Whey Using a Tangential Flow Ultrafiltration Module

    NASA Astrophysics Data System (ADS)

    Das, Bipasha; Bhattacharjee, Sangita; Bhattacharjee, Chiranjib

    2013-09-01

    In this study, ultrafiltration (UF) of pretreated casein whey was carried out in a cross-flow module fitted with 5 kDa molecular weight cut-off polyethersulfone membrane to recover whey proteins in the retentate and lactose in the permeate. Effects of processing conditions, like transmembrane pressure and pH on permeate flux and rejection were investigated and reported. The polarised layer resistance was found to increase with time during UF even in this high shear device. The lactose concentration in the permeate was measured using dinitro salicylic acid method. Enzymatic kinetic study for lactose hydrolysis was carried out at three different temperatures ranging from 30 to 50 °C using β-galactosidase enzyme. The glucose formed during lactose hydrolysis was analyzed using glucose oxidase-peroxidase method. Kinetics of enzymatic hydrolysis of lactose solution was found to follow Michaelis-Menten model and the model parameters were estimated by Lineweaver-Burk plot. The hydrolysis rate was found to be maximum (with Vmax = 5.5091 mmol/L/min) at 30 °C.

  6. Permeability-Selectivity Analysis of Microfiltration and Ultrafiltration Membranes: Effect of Pore Size and Shape Distribution and Membrane Stretching

    PubMed Central

    Siddiqui, Muhammad Usama; Arif, Abul Fazal Muhammad; Bashmal, Salem

    2016-01-01

    We present a modeling approach to determine the permeability-selectivity tradeoff for microfiltration and ultrafiltration membranes with a distribution of pore sizes and pore shapes. Using the formulated permeability-selectivity model, the effect of pore aspect ratio and pore size distribution on the permeability-selectivity tradeoff of the membrane is analyzed. A finite element model is developed to study the effect of membrane stretching on the distribution of pore sizes and shapes in the stretched membrane. The effect of membrane stretching on the permeability-selectivity tradeoff of membranes is also analyzed. The results show that increasing pore aspect ratio improves membrane performance while increasing the width of pore size distribution deteriorates the performance. It was also found that the effect of membrane stretching on the permeability-selectivity tradeoff is greatly affected by the uniformity of pore distribution in the membrane. Stretching showed a positive shift in the permeability-selectivity tradeoff curve of membranes with well-dispersed pores while in the case of pore clustering, a negative shift in the permeability-selectivity tradeoff curve was observed. PMID:27509528

  7. Removal of Trace Pharmaceuticals from Water using coagulation and powdered activated carbon as pretreatment to ultrafiltration membrane system.

    PubMed

    Sheng, Chenguang; Nnanna, A G Agwu; Liu, Yanghe; Vargo, John D

    2016-04-15

    In this study, the efficacy of water treatment technologies: ultra-filtration (UF), powdered activated carbon (PAC), coagulation (COA) and a combination of these technologies (PAC/UF and COA/UF) to remove target pharmaceuticals (Acetaminophen, Bezafibrate, Caffeine, Carbamazepine, Cotinine, Diclofenac, Gemfibrozil, Ibuprofen, Metoprolol, Naproxen, Sulfadimethoxine, Sulfamethazine, Sulfamethoxazole, Sulfathiazole, Triclosan and Trimethoprim) was investigated. Samples of wastewater from municipal WWTPs were analyzed using direct aqueous injection High Performance Liquid Chromatography with Tandem Quadrupole Mass Spectrometric (LC/MS/MS) detection. On concentration basis, results showed an average removal efficiency of 29%, 50%, and 7%, respectively, for the UF, PAC dosage of 50ppm, and COA dosage of 10ppm. When PAC dosage of 100ppm was used as pretreatment to the combined PAC and UF in-line membrane system, a 90.3% removal efficiency was achieved. The removal efficiency of UF in tandem with COA was 33%, an increase of 4% compared with the single UF treatment. The adsorption effect of PAC combined with the physical separation process of UF revealed the best treatment strategy for removing pharmaceutical contaminant from water. PMID:26867086

  8. Seasonal variation of organic matter concentration and characteristics in the Maji ya Chai River (Tanzania): Impact on treatability by ultrafiltration.

    PubMed

    Aschermann, Geert; Jeihanipour, Azam; Shen, Junjie; Mkongo, Godfrey; Dramas, Laure; Croué, Jean-Philippe; Schäfer, Andrea

    2016-09-15

    Many waters in Tanzania exhibit high concentrations of organic matter and dissolved contaminants such as fluoride. Due to bacteria and virus removal, ultrafiltration (UF) is an attractive option for drinking water treatment, and when coupled with adsorbents, may compete with other established processes like nanofiltration (NF) for lower contaminant concentrations. The results presented here examine the characteristics and treatability of tropical natural organic matter (NOM) by UF as a function of seasonal variation. The Tanzanian river Maji ya Chai was sampled monthly during one year. The composition of NOM in Maji ya Chai River is influenced strongly by precipitation. Total organic carbon (TOC), specific ultraviolet absorbance (SUVA) and concentration of allochthonous organics substances (such as humic substances (HS)) are elevated in periods following high precipitation, while TOC is lower and contains more biopolymers in the dry seasons. UF experiments with two regenerated cellulose membranes of different molecular weight cut-off (MWCO, 5 and 10 kDa) were conducted. UF is able to remove 50-95% of TOC with a seasonal variability of 10-20%. Due to the remaining NOM in the water that would contribute to disinfection by-product formation and bacterial regrowth, the physically disinfected water is more applicable for point of use systems than distribution or storage. PMID:27288671

  9. Continuous, online measurement of the absolute plasma refill rate during hemodialysis using feedback regulated ultrafiltration: preliminary results.

    PubMed

    Brummelhuis, Walter J; van Schelven, Leonard J; Boer, Walther H

    2008-01-01

    Methods to continuously measure absolute refill during dialysis are not available. It would be useful to have such a method because it would allow investigating the mechanism of refill the effect of interventions. We designed a feedback algorithm that adjusts ultrafiltration rate (QUF) according to hemoglobin (Hb) concentration changes in such a way that relative blood volume (BV) remains constant within a narrow target range. In this situation, the generated QUF quantitatively reflects refill. Refill patterns were studied in five hypotension prone patients. In addition, on separate occasions, we studied the effect of antiembolism stockings (AES) and infusion of hydroxy-ethylated starch (HAES) on refill in these patients. Refill during the first hour fell significantly from 21 +/- 3 ml/min to 9 +/- 2 ml/min (p < 0.05). In the second hour, refill decreased further and became zero in four out of five patients. Neither AES nor HAES measurably affected refill. The marked and rapid fall in refill in the early stages of dialysis suggests untimely depletion of the interstitial compartment and underestimation of dry weight. We propose that continuous, online measurement of refill patterns may be of value for accurate estimation of dry weight in dialysis patients. PMID:18204322

  10. Microalgae recovery by ultrafiltration using novel fouling-resistant PVDF membranes with in situ PEGylated polyethyleneimine particles.

    PubMed

    Hwang, Taewoon; Kotte, Madhusudhana Rao; Han, Jong-In; Oh, You-Kwan; Diallo, Mamadou S

    2015-04-15

    In this article, we report the preparation, characterization and microalgae recovery potential of a new family of fouling-resistant polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes embedded with hydrophilic and PEGylated polymeric particles. To optimize membrane performance for microalgae harvesting, we investigate the effects of three hydrophilic additives (Pluronic F-127, polyvinylpyrrolidone and polyethylene glycol) on the morphology, pore size, bulk composition, surface composition, wettability and surface charge, flux and fouling resistance of the mixed matrix PVDF membranes with in situ PEGylated polyethyleneimine (PEI) particles. Our filtration experiments show that a mixed matrix PVDF membrane with PEGylated PEI particles and Pluronic F-127 additive (PNSM-1) has an algae retention of 100% with a permeate flux of 96 L/m(2)/hr that is larger (by ∼50%) than that of a commercial and hydrophilic PVDF UF membrane with a molecular weight cut-off of 30 kDa using a suspension of Chlorella sp. KR-1 microalgae with 1.2-1.4 g/L of dry biomass. The algae and water flux recovery rates of our new PNSM-1 are equal to∼ 94% and 100%, respectively, following a simulated membrane wash with deionized water and two subsequent water and microalgae filtration cycles. PMID:25659965

  11. Complexation studies with lanthanides and humic acid analyzed by ultrafiltration and capillary electrophoresis-inductively coupled plasma mass spectrometry.

    PubMed

    Kautenburger, Ralf; Beck, Horst Philipp

    2007-08-01

    For the long-term storage of radioactive waste, detailed information about geo-chemical behavior of radioactive and toxic metal ions under environmental conditions is necessary. Humic acid (HA) can play an important role in the immobilisation or mobilisation of metal ions due to complexation and colloid formation. Therefore, we investigate the complexation behavior of HA and its influence on the migration or retardation of selected lanthanides (europium and gadolinium as homologues of the actinides americium and curium). Two independent speciation techniques, ultrafiltration and capillary electrophoresis coupled with inductively coupled plasma mass spectrometry (CE-ICP-MS) have been compared for the study of Eu and Gd interaction with (purified Aldrich) HA. The degree of complexation of Eu and Gd in 25 mg l(-1) Aldrich HA solutions was determined with a broad range of metal loading (Eu and Gd total concentration between 10(-6) and 10(-4) mol l(-1)), ionic strength of 10 mM (NaClO4) and different pH-values. From the CE-ICP-MS electropherograms, additional information on the charge of the Eu species was obtained by the use of 1-bromopropane as neutral marker. To detect HA in the ICP-MS and separate between HA complexed and non complexed metal ions in the CE-ICP-MS, we have halogenated the HA with iodine as ICP-MS marker. PMID:17459403

  12. Separation Properties of Wastewater Containing O/W Emulsion Using Ceramic Microfiltration/Ultrafiltration (MF/UF) Membranes

    PubMed Central

    Nakamura, Kazuho; Matsumoto, Kanji

    2013-01-01

    Washing systems using water soluble detergent are used in electrical and mechanical industries and the wastewater containing O/W emulsion are discharged from these systems. Membrane filtration has large potential for the efficient separation of O/W emulsion for reuses of treated water and detergent. The separation properties of O/W emulsions by cross-flow microfiltration and ultrafiltration were studied with ceramic MF and UF membranes. The effects of pore size; applied pressure; cross-flow velocity; and detergent concentration on rejection of O/W emulsion and flux were systematically studied. At the condition achieving complete separation of O/W emulsion the pressure-independent flux was observed and this flux behavior was explained by gel-polarization model. The O/W emulsion tended to permeate through the membrane at the conditions of larger pore size; higher emulsion concentration; and higher pressure. The O/W emulsion could permeate the membrane pore structure by destruction or deformation. These results imply the stability of O/W emulsion in the gel-layer formed on membrane surface play an important role in the separation properties. The O/W emulsion was concentrated by batch cross-flow concentration filtration and the flux decline during the concentration filtration was explained by the gel- polarization model. PMID:24958621

  13. Towards a better hydraulic cleaning strategy for ultrafiltration membrane fouling by humic acid: Effect of backwash water composition.

    PubMed

    Chang, Haiqing; Liang, Heng; Qu, Fangshu; Ma, Jun; Ren, Nanqi; Li, Guibai

    2016-05-01

    As a routine measurement to alleviate membrane fouling, hydraulic cleaning is of great significance for the steady operation of ultrafiltration (UF) systems in water treatment processes. In this work, a comparative study was performed to investigate the effects of the composition of backwash water on the hydraulic cleaning performance of UF membranes fouled by humic acid (HA). Various types of backwash water, including UF permeate, Milli-Q water, NaCl solution, CaCl2 solution and HA solution, were compared in terms of hydraulically irreversible fouling index, total surface tension and residual HA. The results indicated that Milli-Q water backwash was superior to UF permeate backwash in cleaning HA-fouled membranes, and the backwash water containing Na(+) or HA outperformed Milli-Q water in alleviating HA fouling. On the contrary, the presence of Ca(2+) in backwash water significantly decreased the backwash efficiency. Moreover, Ca(2+) played an important role in foulant removal, and the residual HA content closely related to the residual Ca(2+) content. Mechanism analysis suggested that the backwash process may involve fouling layer swelling, ion exchange, electric double layer release and competitive complexation. Ion exchange and competitive complexation played significant roles in the efficient hydraulic cleaning associated with Na(+) and HA, respectively. PMID:27155423

  14. Polyaniline-Coated Carbon Nanotube Ultrafiltration Membranes: Enhanced Anodic Stability for In Situ Cleaning and Electro-Oxidation Processes.

    PubMed

    Duan, Wenyan; Ronen, Avner; Walker, Sharon; Jassby, David

    2016-08-31

    Electrically conducting membranes (ECMs) have been reported to be efficient in fouling prevention and destruction of aqueous chemical compounds. In the current study, highly conductive and anodically stable composite polyaniline-carbon nanotube (PANI-CNT) ultrafiltration (UF) ECMs were fabricated through a process of electropolymerization of aniline on a CNT substrate under acidic conditions. The resulting PANI-CNT UF ECMs were characterized by scanning electron microscopy, atomic force microscopy, a four-point conductivity probe, cyclic voltammetry, and contact angle goniometry. The utilization of the PANI-CNT material led to significant advantages, including: (1) increased electrical conductivity by nearly an order of magnitude; (2) increased surface hydrophilicity while not impacting membrane selectivity or permeability; and (3) greatly improved stability under anodic conditions. The membrane's anodic stability was evaluated in a pH-controlled aqueous environment under a wide range of anodic potentials using a three-electrode cell. Results indicate a significantly reduced degradation rate in comparison to a CNT-poly(vinyl alcohol) ECM under high anodic potentials. Fouling experiments conducted with bovine serum albumin demonstrated the capacity of the PANI-CNT ECMs for in situ oxidative cleaning, with membrane flux restored to its initial value under an applied potential of 3 V. Additionally, a model organic compound (methylene blue) was electrochemically transformed at high efficiency (90%) in a single pass through the anodically charged ECM.

  15. Ultra-wetting graphene-based PES ultrafiltration membrane - A novel approach for successful oil-water separation.

    PubMed

    Prince, J A; Bhuvana, S; Anbharasi, V; Ayyanar, N; Boodhoo, K V K; Singh, G

    2016-10-15

    Oil pollution in water and separation of oil from water are receiving much attention in recent years due to the growing environmental concerns. Membrane technology is one of the emerging solutions for oil-water separation. However, there is a limitation in using polymeric membrane for oil water separation due to its surface properties (wetting behaviour), thermal and mechanical properties. Here, we have shown a simple method to increase the hydrophilicity of the polyethersulfone (PES) hollow fibre ultrafiltration (UF) membrane by using carboxyl, hydroxyl and amine modified graphene attached poly acrylonitrile-co-maleimide (G-PANCMI). The prepared membranes were characterized for its morphology, water and oil contact angle, liquid entry pressure of oil (LEPoil), water permeability and finally subjected to a continuous 8 h filtration test of oil emulsion in water. The experimental data indicates that the G-PANCMI play an important role in enhancing the hydrophilicity, permeability and selectivity of the PES membrane. The water contact angle (CAw) of the PES membrane is reduced from 63.7 ± 3.8° to 22.6 ± 2.5° which is 64.5% reduction while, the oil contact angle was increased from 43.6 ± 3.5° to 112.5 ± 3.2° which is 158% higher compared to that of the PES membrane. Similarly, the LEPoil increased 350% from 50 ± 10 kPa of the control PES membrane to 175 ± 25 kPa of PES-G-PANCMI membrane. More importantly, the water permeability increased by 43% with >99% selectivity. Based on our findings we believe that the development of PES-G-PANCMI membrane will open up a solution for successful oil-water separation. PMID:27475120

  16. Study on an integrated process combining ozonation with ceramic ultra-filtration for decentralized supply of drinking water.

    PubMed

    Zhu, Jia; Fan, Xiao J; Tao, Yi; Wei, De Q; Zhang, Xi H

    2014-09-19

    An integrated process was specifically developed for the decentralized supply of drinking water from micro-polluted surface water in the rural areas of China. The treatment process combined ozonation with ceramic ultra-filtration (UF), coagulation for pre-treatment and granular activated carbon filtration. A flat-sheet ceramic membrane was used with a cut-off of 60 nm and the measurement of 254 mm (length) × 240 mm (width) × 6 mm (thickness). Ozonation and ceramic UF was set up whthin one reactor. The experimental results showed that the removal efficiencies of the dissolved organic carbon (DOC) and the formation potential of trihalomethanes (THMs), haloacetic acids (HAAs) and ammonia were 80%, 76%, 70% and 90%, respectively; that the turbidity of the product water was below 0.2 NTU and the particle count number (particles larger than 2 μm) was less than 50 counts per mL. The result also showed that all the pathogenic microorganisms were retained by the ceramic and that UF. Ozonation played a critical role in the control of membrane fouling and the removal of contaminants. Exactly, the membrane fouling can be controlled in situ with 3 mg L(-1) ozone at the permeate flux of 80 L m(-2) h(-1), yet the required dosage of ozone was dependent on the quality of the raw water. Therefore, this study is able to provide a highly compacted system for decentralized supply of high-quality drinking water in terms of both chemical and microbiological safety for the rural areas in China.

  17. Development of High-Antifouling PPSU Ultrafiltration Membrane by Using Compound Additives: Preparation, Morphologies, and Filtration Resistant Properties.

    PubMed

    Liu, Jie; Zhong, Zhencheng; Ma, Rui; Zhang, Weichen; Li, Jiding

    2016-01-01

    In this study, flat sheet asymmetric polyphenylsulfone (PPSU) ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS) method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was achieved by establishing a bridge between the membrane preparation parameters and separation performances. All prepared membranes were characterized by using a scanning electron microscope (SEM), contact angle analysis, porosity, maximum pore size, water and BSA solution permeability studies. The performance efficiency of the membrane was evaluated by using BSA as a model foulant in terms of permeability, solute rejection (R), Rm (membrane inherent resistance), Rc (cake layer resistance), and Rp (pore plugging resistance). The results showed that when the compound additives were used, the inter-connected pores were observed, maximum pore size, contact angle and membrane filtration resistance decreased, while the porosity increased. When PVP compound additives were added, the water flux increased from 80.4 to 148.1 L/(m²·h), the BSA rejection increased from 53.2% to 81.5%. A similar trend was observed for membranes with added PEG compound additives; the water flux and BSA rejection simultaneously increased. The filtration resistance decreased as a result of compound additives. The uniformity of membrane and the number of effective pores could be enhanced by adding compound additives through the cooperation of different additives.

  18. Development of High-Antifouling PPSU Ultrafiltration Membrane by Using Compound Additives: Preparation, Morphologies, and Filtration Resistant Properties.

    PubMed

    Liu, Jie; Zhong, Zhencheng; Ma, Rui; Zhang, Weichen; Li, Jiding

    2016-01-01

    In this study, flat sheet asymmetric polyphenylsulfone (PPSU) ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS) method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was achieved by establishing a bridge between the membrane preparation parameters and separation performances. All prepared membranes were characterized by using a scanning electron microscope (SEM), contact angle analysis, porosity, maximum pore size, water and BSA solution permeability studies. The performance efficiency of the membrane was evaluated by using BSA as a model foulant in terms of permeability, solute rejection (R), Rm (membrane inherent resistance), Rc (cake layer resistance), and Rp (pore plugging resistance). The results showed that when the compound additives were used, the inter-connected pores were observed, maximum pore size, contact angle and membrane filtration resistance decreased, while the porosity increased. When PVP compound additives were added, the water flux increased from 80.4 to 148.1 L/(m²·h), the BSA rejection increased from 53.2% to 81.5%. A similar trend was observed for membranes with added PEG compound additives; the water flux and BSA rejection simultaneously increased. The filtration resistance decreased as a result of compound additives. The uniformity of membrane and the number of effective pores could be enhanced by adding compound additives through the cooperation of different additives. PMID:27338487

  19. Consecutive chemical cleaning of fouled PVC membrane using NaOH and ethanol during ultrafiltration of river water.

    PubMed

    Tian, Jia-yu; Chen, Zhong-lin; Yang, Yan-ling; Liang, Heng; Nan, Jun; Li, Gui-bai

    2010-01-01

    Chemical cleaning of fouled hollow-fiber polyvinyl chloride (PVC) membrane with the consecutive use of NaOH and ethanol during ultrafiltration of river water was investigated in the study. Results showed that through the chemical cleaning with 1% NaOH for 30min, a negative cleaning efficiency of -14.6% was observed for the PVC membrane. This might be due to the increase of membrane hydrophobicity, which was reflected by the increase of contact angle from 69.7 degrees to 87.6 degrees . On the other hand, the cleaning efficiency of 85.1% was obtained by the consecutive cleaning with 30min of 1% NaOH and 30min of ethanol. Individual ethanol cleaning could remove 48.5% of the irreversible resistance, indicating that NaOH cleaning also made its contribution (36.6%) to the removal of membrane foulants. Scanning electronic microscopy (SEM) and atomic force microscopy (AFM) analyses demonstrated that both NaOH and ethanol were not only able to eliminate the foulants on membrane surface, but also able to remove the in-pore fouling of the PVC membrane. The synergetic effects for removing membrane foulants were observed between the NaOH and ethanol. Furthermore, ethanol could also restore the hydrophilicity of the membrane by decreasing the contact angle from 87.6 degrees to 71.4 degrees . Considering that ethanol is easy to be used and reclaimed, the consecutive chemical cleaning by alkali and ethanol is recommended for PVC membrane in filtration of surface water.

  20. Development of High-Antifouling PPSU Ultrafiltration Membrane by Using Compound Additives: Preparation, Morphologies, and Filtration Resistant Properties

    PubMed Central

    Liu, Jie; Zhong, Zhencheng; Ma, Rui; Zhang, Weichen; Li, Jiding

    2016-01-01

    In this study, flat sheet asymmetric polyphenylsulfone (PPSU) ultrafiltration membranes with enhanced antifouling properties were prepared with a non-solvent induced phase separation (NIPS) method through compound additives containing a polymeric pore-forming agent, a small molecular non-solvent and a surfactant. The formation processes of the porous asymmetric membranes with different kinds of additives were studied in detail, and the microstructure controllable preparation of membrane was achieved by establishing a bridge between the membrane preparation parameters and separation performances. All prepared membranes were characterized by using a scanning electron microscope (SEM), contact angle analysis, porosity, maximum pore size, water and BSA solution permeability studies. The performance efficiency of the membrane was evaluated by using BSA as a model foulant in terms of permeability, solute rejection (R), Rm (membrane inherent resistance), Rc (cake layer resistance), and Rp (pore plugging resistance). The results showed that when the compound additives were used, the inter-connected pores were observed, maximum pore size, contact angle and membrane filtration resistance decreased, while the porosity increased. When PVP compound additives were added, the water flux increased from 80.4 to 148.1 L/(m2·h), the BSA rejection increased from 53.2% to 81.5%. A similar trend was observed for membranes with added PEG compound additives; the water flux and BSA rejection simultaneously increased. The filtration resistance decreased as a result of compound additives. The uniformity of membrane and the number of effective pores could be enhanced by adding compound additives through the cooperation of different additives. PMID:27338487

  1. Ultra-wetting graphene-based PES ultrafiltration membrane - A novel approach for successful oil-water separation.

    PubMed

    Prince, J A; Bhuvana, S; Anbharasi, V; Ayyanar, N; Boodhoo, K V K; Singh, G

    2016-10-15

    Oil pollution in water and separation of oil from water are receiving much attention in recent years due to the growing environmental concerns. Membrane technology is one of the emerging solutions for oil-water separation. However, there is a limitation in using polymeric membrane for oil water separation due to its surface properties (wetting behaviour), thermal and mechanical properties. Here, we have shown a simple method to increase the hydrophilicity of the polyethersulfone (PES) hollow fibre ultrafiltration (UF) membrane by using carboxyl, hydroxyl and amine modified graphene attached poly acrylonitrile-co-maleimide (G-PANCMI). The prepared membranes were characterized for its morphology, water and oil contact angle, liquid entry pressure of oil (LEPoil), water permeability and finally subjected to a continuous 8 h filtration test of oil emulsion in water. The experimental data indicates that the G-PANCMI play an important role in enhancing the hydrophilicity, permeability and selectivity of the PES membrane. The water contact angle (CAw) of the PES membrane is reduced from 63.7 ± 3.8° to 22.6 ± 2.5° which is 64.5% reduction while, the oil contact angle was increased from 43.6 ± 3.5° to 112.5 ± 3.2° which is 158% higher compared to that of the PES membrane. Similarly, the LEPoil increased 350% from 50 ± 10 kPa of the control PES membrane to 175 ± 25 kPa of PES-G-PANCMI membrane. More importantly, the water permeability increased by 43% with >99% selectivity. Based on our findings we believe that the development of PES-G-PANCMI membrane will open up a solution for successful oil-water separation.

  2. The role of hydrodynamic conditions and pH on algal-rich water fouling of ultrafiltration.

    PubMed

    Zhang, Yan; Tang, Chuyang Y; Li, Guibai

    2012-10-01

    The aim of this paper was to study the membrane fouling phenomena by eutrophic water using Microcystis aeruginosa under various operational conditions (flux and air flow rate) and solution chemistry (pH). All the experiments were performed in a lab scale employing the polyvinyl chloride ultrafiltration membrane with nominal cut-off of 10 kDa. A slight fouling appeared at the flux not more than 10 L/m²/h, and the trend of trans-membrane pressure (TMP) development varied as a function of flux from linear to exponential with the increase of cell concentration. This paper also studied an important consideration of aeration in algal fouling: shear force. Besides alleviating membrane fouling, the shear produced by the bubbling should take responsible for the breakup of cells and the release of intracellular organic matters which caused the rate of the TMP increase closed to that without aeration. The optimum aeration intensity was observed to be 2.5 m³/m²/h in this experimental condition. As another important parameter considered in the study, the pH value of the raw water changed the physical and chemical reaction between the membrane and foulants or themselves. The results showed that the final TMP reduced with the pH increase due to the electro-static repulsion strengthening between the macromolecules which developed a looser gel. The most severe fouling was obtained at pH 5.0 near to the iso-electric point of algal solution, where electrostatic repulsion between algal cells was weakest. Furthermore, low pH value had a negative impact on cell integrity which gave rise to much more dissolved algogenic organic matter in the solution. It also played a part role on the membrane fouling.

  3. Exploring the synergetic effects of graphene oxide (GO) and polyvinylpyrrodione (PVP) on poly(vinylylidenefluoride) (PVDF) ultrafiltration membrane performance

    NASA Astrophysics Data System (ADS)

    Chang, Xiaojing; Wang, Zhenxing; Quan, Shuai; Xu, Yanchao; Jiang, Zaixing; Shao, Lu

    2014-10-01

    Membrane surface and cross-sectional morphology created during membrane formation is one of the most essential factors determining membrane separation performance. However, the complicated interactions between added nanoparticles and additives influencing membrane morphology and performance during building membrane architectures had been generally neglected. In this study, asymmetric PVDF composite ultrafiltration (UF) membranes containing graphene oxides (GO) were prepared by using N-methyl pyrrolidone (NMP) as solvent and polyvinylpyrrodione (PVP) as the pore forming reagent. In the first time, the effects of mutual interactions between GO and PVP on membranes surface compositions, morphology and performance were investigated in detail. The variation in chemical properties of different membranes and hydrogen bonds in the membrane containing GO and PVP were confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR). Atomic force microscopy (AFM), scanning electron microscopy (SEM), and contact angle (CA) were utilized to clarify the synergetic effects of GO and PVP on morphologies and surface hydrophilicity of membranes. Besides, water flux, bovine serum albumin (BSA) rejection and attenuate coefficient were also determined to investigate filtration performance of various membranes. Compared with pure PVDF membrane, the comprehensive performance of PVDF/GO/PVP membrane has been obviously improved. The surface hydrophilicity and anti-fouling performance were enhanced by the synergistic effects of incorporated GO and PVP. When the PVP content was 0.25 wt.% and the GO content was 0.5 wt.%, the optimized performance can be obtained due to the formation of hydrogen bonds between GO and PVP.

  4. Assessing the role of feed water constituents in irreversible membrane fouling of pilot-scale ultrafiltration drinking water treatment systems.

    PubMed

    Peiris, R H; Jaklewicz, M; Budman, H; Legge, R L; Moresoli, C

    2013-06-15

    Fluorescence excitation-emission matrix (EEM) approach together with principal component analysis (PCA) was used for assessing hydraulically irreversible fouling of three pilot-scale ultrafiltration (UF) systems containing full-scale and bench-scale hollow fiber membrane modules in drinking water treatment. These systems were operated for at least three months with extensive cycles of permeation, combination of back-pulsing and scouring and chemical cleaning. The principal component (PC) scores generated from the PCA of the fluorescence EEMs were found to be related to humic substances (HS), protein-like and colloidal/particulate matter content. PC scores of HS- and protein-like matter of the UF feed water, when considered separately, showed reasonably good correlations with the rate of hydraulically irreversible fouling for long-term UF operations. In contrast, comparatively weaker correlations for PC scores of colloidal/particulate matter and the rate of hydraulically irreversible fouling were obtained for all UF systems. Since, individual correlations could not fully explain the evolution of the rate of irreversible fouling, multi-linear regression models were developed to relate the combined effect of HS-like, protein-like and colloidal/particulate matter PC scores to the rate of hydraulically irreversible fouling for each specific UF system. These multi-linear regression models revealed significant individual and combined contribution of HS- and protein-like matter to the rate of hydraulically irreversible fouling, with protein-like matter generally showing the greatest contribution. The contribution of colloidal/particulate matter to the rate of hydraulically irreversible fouling was not as significant. The addition of polyaluminum chloride, as coagulant, to UF feed appeared to have a positive impact in reducing hydraulically irreversible fouling by these constituents. The proposed approach has applications in quantifying the individual and synergistic

  5. Highly integrated hybrid process with ceramic ultrafiltration-membrane for advanced treatment of drinking water: a pilot study.

    PubMed

    Guo, Jianning; Wang, Lingyun; Zhu, Jia; Zhang, Jianguo; Sheng, Deyang; Zhang, Xihui

    2013-01-01

    This article presents a highly integrated hybrid process for the advanced treatment of drinking water in dealing with the micro-polluted raw water. A flat sheet ceramic membrane with the pore size of 50∼60 nm for ultrafiltration (UF) is used to integrate coagulation and ozonation together. At the same time, biological activated carbon filtration (BAC) is used to remove the ammonia and organic pollutants in raw water. A pilot study in the scale of 120 m(3)/d has been conducted in Southern China. The mainly-analyzed parameters include turbidity, particle counts, ammonia, total organic carbon (TOC), UV254, biological dissolved organic carbon (BDOC), dissolved oxygen (DO) as well as trans-membrane pressure (TMP). The experiments demonstrated that ceramic UF-membrane was able to remove most of turbidity and suspended particulate matters. The final effluent turbidity reached to 0.14 NTU on average. BAC was effective in removing ammonia and organic matters. Dissolved oxygen (DO) is necessary for the biodegradation of ammonia at high concentration. The removal efficiencies reached to 90% for ammonia with the initial concentration of 3.6 mg/L and 76% for TOC with the initial concentration of 3.8 mg/L. Ozonation can alter the molecular structure of organics in terms of UV254, reduce membrane fouling, and extend the operation circle. It is believed the hybrid treatment process developed in this article can achieve high performance with less land occupation and lower cost compared with the conventional processes. It is especially suitable for the developing countries in order to obtain high-quality drinking water in a cost-effective way.

  6. Cross flow ultrafiltration of Cr (VI) using MCM-41, MCM-48 and Faujasite (FAU) zeolite-ceramic composite membranes.

    PubMed

    Basumatary, Ashim Kumar; Kumar, R Vinoth; Ghoshal, Aloke Kumar; Pugazhenthi, G

    2016-06-01

    This work describes the removal of Cr (VI) from aqueous solution in cross flow mode using MCM-41, MCM-48 and FAU zeolite membranes prepared on circular shaped porous ceramic support. Ceramic support was manufactured using locally available clay materials via a facile uni-axial compaction method followed by sintering process. A hydrothermal technique was employed for the deposition of zeolites on the ceramic support. The porosity of ceramic support (47%) is reduced by the formation of MCM-41 (23%), MCM-48 (22%) and FAU (33%) zeolite layers. The pore size of the MCM-41, MCM-48 and FAU membrane is found to be 0.173, 0.142, and 0.153 μm, respectively, which is lower than that of the support (1.0 μm). Cross flow ultrafiltration experiments of Cr (VI) were conducted at five different applied pressures (69-345 kPa) and three cross flow rates (1.11 × 10(-7) - 2.22 × 10(-7) m(3)/s). The filtration studies inferred that the performance of the fabricated zeolite composite membranes is optimum at the maximum applied pressure (345 kPa) and the highest rejection is obtained with the lowest cross flow rate (1.11 × 10(-7) m(3)/s) for all three zeolite membrane. The permeate flux of MCM-41, MCM-48 and FAU zeolite composite membranes are almost remained constant in the entire duration of the separation process. The highest removal of 82% is shown by FAU membrane, while MCM-41 and MCM-48 display 75% and 77% of Cr (VI) removal, respectively for the initial feed concentration of 1000 ppm with natural pH of the solution at an applied pressure of 345 kPa. PMID:27031807

  7. [Formation and Variation of Brominated Disinfection By-products in A Combined Ultrafiltration and Reverse Osmosis Process for Seawater Desalination].

    PubMed

    Yang, Zhe; Sun, Ying-xue; Shi, Na; Hu, Hong-ying

    2015-10-01

    The characteristics of dissolved organic matter (DOM) and brominated disinfection by-products ( Br-DBPs ) during a seawater desalination ultrafiltration (UF) combined reverse osmosis (RO) process were studied. The seawater contained high level of bromide ion (45.6-50.9 mg x L(-1)) and aromatic compounds with specific ultraviolet absorbance ( SUVA) of 3.6-6.0 L x (mg x m)(-1). The tryptophan-like aromatic protein, fulvic acid-like and soluble microbial by-product-like were the main fluorescent DOM in the seawater. After pre-chlorination of the seawater, the concentrations of DBPs was significantly increased in the influent of UF, which was dominantly the Br-DBPs. Bromoform (CHBr3) accounted for 70.48% - 91.50% of total trihalomethanes (THMs), dibromoacetic acid (Br2CHCO2H) occupied 81.14% - 100% of total haloacetic acids (HAAs) and dibromoacetonitrile (C2HBr2N) occupied 83.77% - 87.45% of total haloacetonitriles ( HANs). The removal efficiency of THMs, HAAs and HANs by the UF membrane was 36.63% - 40.39%, 73.83% - 95.38% and 100%, respectively. The RO membrane could completely remove the HAAs, while a little of the THMs was penetrated. The antiestrogenic activity in the seawater was 0.35 - 0.44 mg x L(-1), which was increased 32% - 69% after the pre-chlorination. The DBPs and other bio-toxic organics which formed during the UF-RO process were finally concentrated in the UF concentrate and RO concentrate.

  8. Fouling of nanofiltration, reverse osmosis, and ultrafiltration membranes by protein mixtures: the role of inter-foulant-species interaction.

    PubMed

    Wang, Yi-Ning; Tang, Chuyang Y

    2011-08-01

    Protein fouling of nanofiltration (NF), reverse osmosis (RO), and ultrafiltration (UF) membranes by bovine serum albumin (BSA), lysozyme (LYS), and their mixture was investigated under cross-flow conditions. The effect of solution chemistry, membrane properties, and permeate flux level was systematically studied. When the solution pH was within the isoelectric points (IEPs) of the two proteins (i.e., pH 4.7-10.4), the mixed protein system experienced more severe flux decline compared to the respective single protein systems, which may be attributed to the electrostatic attraction between the negatively charged BSA and positively charged LYS molecules. Unlike a typical single protein system, membrane fouling by BSA-LYS mixture was only weakly dependent on solution pH within this pH range, and increased ionic strength was found to enhance the membrane flux as a result of the suppressed BSA-LYS electrostatic attraction. Membrane fouling was likely controlled by foulant-fouled-membrane interaction under severe fouling conditions (elevated flux level and unfavorable solution chemistry that promotes fouling), whereas it was likely dominated by foulant-clean-membrane interaction under mild fouling conditions. Compared to nonporous NF and RO membranes, the porous UF membrane was more susceptible to dramatic flux decline due to the increased risk of membrane pore plugging. This study reveals that membrane fouling by mixed macromolecules may behave very differently from that by typical single foulant system, especially when the inter-foulant-species interaction dominates over the intra-species interaction in the mixed foulant system.

  9. Assessing the role of feed water constituents in irreversible membrane fouling of pilot-scale ultrafiltration drinking water treatment systems.

    PubMed

    Peiris, R H; Jaklewicz, M; Budman, H; Legge, R L; Moresoli, C

    2013-06-15

    Fluorescence excitation-emission matrix (EEM) approach together with principal component analysis (PCA) was used for assessing hydraulically irreversible fouling of three pilot-scale ultrafiltration (UF) systems containing full-scale and bench-scale hollow fiber membrane modules in drinking water treatment. These systems were operated for at least three months with extensive cycles of permeation, combination of back-pulsing and scouring and chemical cleaning. The principal component (PC) scores generated from the PCA of the fluorescence EEMs were found to be related to humic substances (HS), protein-like and colloidal/particulate matter content. PC scores of HS- and protein-like matter of the UF feed water, when considered separately, showed reasonably good correlations with the rate of hydraulically irreversible fouling for long-term UF operations. In contrast, comparatively weaker correlations for PC scores of colloidal/particulate matter and the rate of hydraulically irreversible fouling were obtained for all UF systems. Since, individual correlations could not fully explain the evolution of the rate of irreversible fouling, multi-linear regression models were developed to relate the combined effect of HS-like, protein-like and colloidal/particulate matter PC scores to the rate of hydraulically irreversible fouling for each specific UF system. These multi-linear regression models revealed significant individual and combined contribution of HS- and protein-like matter to the rate of hydraulically irreversible fouling, with protein-like matter generally showing the greatest contribution. The contribution of colloidal/particulate matter to the rate of hydraulically irreversible fouling was not as significant. The addition of polyaluminum chloride, as coagulant, to UF feed appeared to have a positive impact in reducing hydraulically irreversible fouling by these constituents. The proposed approach has applications in quantifying the individual and synergistic

  10. Evaluation of enantioselective binding of propanocaine to human serum albumin by ultrafiltration and electrokinetic chromatography under intermediate precision conditions.

    PubMed

    Martínez-Gómez, María Amparo; Escuder-Gilabert, Laura; Villanueva-Camañas, Rosa María; Sagrado, Salvador; Medina-Hernández, María José

    2012-03-15

    Stereoselectivity in protein binding can have a significant effect on the pharmacokinetic and pharmacodynamic properties of chiral drugs. In this paper, the enantioselective binding of propanocaine (PRO) enantiomers to human serum albumin (HSA), the most relevant plasmatic protein in view of stereoselectivity, has been evaluated by incubation and ultrafiltration of racemic PRO-HSA mixtures and chiral analysis of the bound and unbound fractions by electrokinetic chromatography using HSA as chiral selector. Experimental conditions for the separation of PRO enantiomers using HSA as chiral selector and electrokinetic chromatography have been optimised. Affinity constants and protein binding in percentage (PB) were obtained for both enantiomers of PRO, as well as the enantioselectivity (ES) to HSA. Data were obtained in two independent working sessions (days). The influence of the session and fraction processed factors were examined. A univariate direct-estimation approach was used facilitating outliers' identification and statistical comparison. Non-linear fitting of data was used to verify the stoichiometry and affinity estimations obtained by the direct approach. Robust statistics were applied to obtain reliable estimations of uncertainty, accounting for the factors (day and processed fraction), thus representing intermediate precision conditions. Mimicking in vivo experimental conditions, information unapproachable by in vivo experiments was obtained for PRO enantiomers interacting with HSA. For the first (E1) and the second (E2) eluted PRO enantiomers the results were: 1:1 stoichiometry, medium affinity constants, logK(E1)=3.20±0.16 and log K(E2)=3.40±0.14, medium protein binding percentage, PB=48.7 and 60.1% for E1 and E2, respectively, and moderate but significant enantioselectivity, ES=K(E2)/K(E1)=1.5±0.3.

  11. Antibacterial activity of Enterococcus faecium derived from Koopeh cheese against Listeria monocytogenes in probiotic ultra-filtrated cheese

    PubMed Central

    Hassanzadazar, Hassan; Ehsani, Ali; Mardani, Karim

    2014-01-01

    Viability of probiotic bacteria in food during maintenance and time of consuming in food has become a challenge in food hygiene and technology and is important for representing their beneficial health effects. The aim of this study was to determine the survival of probiotic Enterococcus faecium derived from Koopeh cheese added to industrial Iranian ultra-filtrated (UF) cheese and screening for antimicrobial activity of Enterococcus faecium against Listeria monocytogenes during two months of cheese ripening. Physiochemical and standard microbial methods were used for isolation of Enterococcus strains in cheese samples. The initial number of lactic acid bacteria (LAB) as starter culture was 6 Log g-1 in control samples. The counts started to decrease slightly after day seven (p < 0.05) and dropped to 5 Log g-1 at the end of 60 days. The count of LAB in the test groups decreased to 11 Log g-1 on the day 60 of ripening. The number of Enterococcus faecium was 6 Log g-1 on the day 60. The count of Listeria monocytogenes after 60 days of ripening in blank sample decreased 1 Log but in test samples with protective strain decreased 3 Log in 30 days and reached to zero at 45 days. There were not significant (p < 0.05) changes in chemical parameters such as fat, protein and total solid of UF cheese treatment groups. The results showed that Enterococcus faecium of Koopeh cheese was suitable for development of an acceptable probiotic UF cheese and could be adapted to industrial production of UF cheese. PMID:25568714

  12. Application of ultrafiltration and stable isotopic amendments to field studies of mercury partitioning to filterable carbon in lake water and overland runoff

    USGS Publications Warehouse

    Babiarz, C.L.; Hurley, J.P.; Krabbenhoft, D.P.; Gilmour, C.; Branfireun, B.A.

    2003-01-01

    Results from pilot studies on colloidal phase transport of newly deposited mercury in lake water and overland runoff demonstrate that the combination of ultrafiltration, and stable isotope amendment techniques is a viable tool for the study of mercury partitioning to filterable carbon. Ultrafiltration mass balance calculations were generally excellent, averaging 97.3, 96.1 and 99.8% for dissolved organic carbon (DOC), total mercury (HgT), and methylmercury (MeHg), respectively. Sub nanogram per liter quantities of isotope were measurable, and the observed phase distribution from replicate ultrafiltration separations on lake water agreed within 20%. We believe the data presented here are the first published colloidal phase mercury data on lake water and overland runoff from uncontaminated sites. Initial results from pilot-scale lake amendment experiments indicate that the choice of matrix used to dissolve the isotope did not affect the initial phase distribution of the added mercury in the lake. In addition there was anecdotal evidence that native MeHg was either recently produced in the system, or at a minimum, that this 'old' MeHg partitions to the same subset of DOC that binds the amended mercury. Initial results from pilot-scale overland runoff experiments indicate that less than 20% of newly deposited mercury was transported in the filterable fraction (<0.7 ??m). There is some indication of colloidal phase enrichment of mercury in runoff compared to the phase distribution of organic carbon, but the mechanism of this enrichment is unclear. The phase distribution of newly deposited mercury can differ from that of organic carbon and native mercury, suggesting that the quality of the carbon (available ligands), not the quantity of carbon, regulates partitioning. Further characterization of DOC is needed to clarify the underlying mechanisms. ?? 2002 Elsevier Science B.V. All rights reserved.

  13. Trace elements in organic- and iron-rich surficial fluids of the boreal zone: Assessing colloidal forms via dialysis and ultrafiltration

    NASA Astrophysics Data System (ADS)

    Vasyukova, E. V.; Pokrovsky, O. S.; Viers, J.; Oliva, P.; Dupré, B.; Martin, F.; Candaudap, F.

    2010-01-01

    On-site size fractionation of about 40 major and trace elements (TE) was performed on waters from boreal small rivers and their estuaries in the Karelia region of North-West Russia around the "Vetreny Belt" mountain range and in Paanajärvi National Park (Northern Karelia). Samples were filtered in the field using a progressively decreasing pore size (5 μm, 2.5 (3) μm, 0.22 (0.45) μm, 100 kDa, 10 and 1 kDa) by means of frontal filtration and ultrafiltration (UF) techniques and employing in-situ dialysis with 10 and 1 kDa membranes followed by ICP-MS analysis. For most samples, dialysis yields a systematically higher (factor of 2-3) proportion of colloidal forms compared to UF. Nevertheless, dialysis is able to provide a fast and artefact-free in-situ separation of colloidal and dissolved components. Similar to previous studies in European subarctic zones, poor correlation of iron concentration with that of organic carbon (OC) in (ultra)filtrates and dialysates reflect the presence of two pools of colloids composed of organic-rich and Fe-rich particles. All major anions and silica are present as dissolved species (or solutes) passing through the 1-kDa membrane. Size-separation ultrafiltration experiments show the existence of larger or smaller pools of colloidal particles different for each of the considered elements. The effect of rock lithology (acidic versus basic) on the colloidal speciation of TE is seen solely in the increase of Fe and some accompanying TE concentrations in catchment areas dominated by basic rocks compared to granitic catchments. Neither the ultrafiltration pattern nor the relative proportions of colloidal versus truly dissolved TE are affected by the lithology of the underlying rocks: within ±10% uncertainty, the two colloidal (10 kDa-0.22 μm and 1-10 kDa) and the truly dissolved (<1 kDa) pools show no difference in percentage of TE distribution between two types of bedrock lithology. The same conclusion is held for organic- and Fe

  14. Phenytoin free fraction determination: comparison of an improved direct serum injection high-performance liquid chromatographic method to ultrafiltration coupled with fluorescence polarization immunoassay.

    PubMed

    Gurley, B J; Marx, M; Olsen, K

    1995-08-18

    Recent developments in restricted-access media (RAM) liquid chromatography make the simultaneous determination of total and free phenytoin concentrations possible by direct injection of drug-containing serum samples. A comparison of phenytoin free fraction determination by ultrafiltration coupled with fluorescence polarization immunoassay (TDX) to an improved direct injection RAM-HPLC method is presented. Our improved method differs from those previously reported with regard to column type, mobile-phase composition, and column temperature. Replicate samples analyzed by each method yielded similar values for serum phenytoin free fraction. PMID:8548029

  15. Combination of preparative HPLC and HSCCC methods to separate phosphodiesterase inhibitors from Eucommia ulmoides bark guided by ultrafiltration-based ligand screening.

    PubMed

    Shi, Shu-Yun; Peng, Mi-Jun; Zhang, Yu-Ping; Peng, Sheng

    2013-05-01

    Phosphodiesterase (PDE) inhibitors are widely used because of their various pharmacological properties, and natural products are considered the most productive source of PDE inhibitors. In this work, a new ultrafiltration-high-performance liquid chromatography (HPLC)-diode-array detection-mass spectrometry based ligand screening was developed for the first screening of PDE inhibitors from Eucommia ulmoides bark, and then the target bioactive compounds were prepared by combination of stepwise preparative HPLC and high-speed countercurrent chromatography (HSCCC) methods. Experiments were conducted to optimize the parameters in ultrafiltration, stepwise preparative HPLC, and HSCCC to allow rapid and effective screening and isolation of active compounds from complex mixtures. Seven lignans with purity over 97 % were isolated and identified by their UV, electrospray ionization mass spectrometry, and NMR data as (+)-pinoresinol-4,4'-di-O-β-D-glucopyranoside (1), (+)-pinoresinol-4-O-β-D-glucopyranosyl(1 → 6)-β-D-glucopyranoside (2), (+)-medioresinol-4,4'-di-O-β-D-glucopyranoside (3), (+)-syringaresinol-4,4'-di-O- β-D-glucopyranoside (4), (-)-olivil-4'-O-β-D-glucopyranoside (5), (-)-olivil-4-O-β-D- glucopyranoside (6), and (+)-pinoresinol-4-O-β-D-glucopyranoside (7). Compound 2 was first isolated from the genus Eucommia. Lignan diglucopyranosides (compounds 1-4) shower a greater inhibitory effect than lignan monoglucopyranosides (compounds 5-7). The method developed could be widely applied for high-throughput screening and preparative isolation of PDE inhibitors from natural products.

  16. Possibilities for recycling cellulases after use in cotton processing: part II: Separation of cellulases from reaction products and released dyestuffs by ultrafiltration.

    PubMed

    Azevedo, Helena; Bishop, David; Cavaco-Paulo, Artur

    2002-04-01

    The adsorption and activity of a total cellulase (Trichoderma reesei) was measured and compared on undyed and dyed cotton fabrics. Recovery of enzymes from the reaction mixture and by desorption from the cotton substrate was evaluated. About 80% of the initial protein could be recovered. The removal of released products (soluble reducing sugars and dyes) from the treatment liquor and subsequent concentration of cellulase proteins was performed using an ultrafiltration membrane. Strong protein-dye interactions made it impossible to separate efficiently the dyes from the enzyme-containing treatment liquors. The use of surfactants did not enhance cellulase desorption from cotton fabric. Although anionic surfactants have a deactivating effect on cellulases, this effect seems to be reversible, since after ultrafiltration the cellulase activity was similar to that of enzymes desorbed with buffer only. Humicola insolens cellulases were shown to be much more sensitive to anionic surfactant than T. reesei cellulases. The use of cellulases that bind reversibly to cellulose is suggested for achieving more efficient cellulase recycling and for reducing backstaining by dye-cellulase complexes.

  17. Use of Enterococcus faecalis and Bacillus atrophaeus as surrogates to establish and maintain laboratory proficiency for concentration of water samples using ultrafiltration.

    PubMed

    Mapp, Latisha; Klonicki, Patricia; Takundwa, Prisca; Hill, Vincent R; Schneeberger, Chandra; Knee, Jackie; Raynor, Malik; Hwang, Nina; Chambers, Yildiz; Miller, Kenneth; Pope, Misty

    2015-11-01

    The U.S. Environmental Protection Agency's (EPA) Water Laboratory Alliance (WLA) currently uses ultrafiltration (UF) for concentration of biosafety level 3 (BSL-3) agents from large volumes (up to 100-L) of drinking water prior to analysis. Most UF procedures require comprehensive training and practice to achieve and maintain proficiency. As a result, there was a critical need to develop quality control (QC) criteria. Because select agents are difficult to work with and pose a significant safety hazard, QC criteria were developed using surrogates, including Enterococcus faecalis and Bacillus atrophaeus. This article presents the results from the QC criteria development study and results from a subsequent demonstration exercise in which E. faecalis was used to evaluate proficiency using UF to concentrate large volume drinking water samples. Based on preliminary testing EPA Method 1600 and Standard Methods 9218, for E. faecalis and B. atrophaeus respectively, were selected for use during the QC criteria development study. The QC criteria established for Method 1600 were used to assess laboratory performance during the demonstration exercise. Based on the results of the QC criteria study E. faecalis and B. atrophaeus can be used effectively to demonstrate and maintain proficiency using ultrafiltration.

  18. [Blood gas and acid-base changes and rhythmologic tolerance of acetate and bicarbonate hemodialysis using a standard dialyser with high sodium and control of ultrafiltration].

    PubMed

    Westeel, P F; Coevoet, B; Bens, J L; Neuville, M; Morinière, P; Fievet, P; Dkhissi, H; Fournier, A

    1983-01-01

    In order to demonstrate a possible superiority of bicarbonate dialysis (HDB) over acetate dialysis (HDA) in conditions of standard dialysis (4 hours on a 1 m2 cuprophan dialyser) but with a bath rich in sodium (143 mEq/l) and control of ultrafiltration, we have compared 2 sequences of 3 runs of HDA and HDB with these conditions in 8 patients as regards their acido-basic and cardiologic parameters (continuous monitoring of ECG by Holter, regular measurement of blood pressure). Acid base balance study in AHD led to the distinction of 2 groups according to wether their plasma bicarbonate increased or decreased during the run. Rythmological tolerance was the same in BHD and AHD, wether all patients or both groups were considered. Heart rate was however slightly but significantly higher during AHD than during BHD, in the patients whose plasma bicarbonate decreased. In conclusion, the benefit of HDB is not remarkable when HDA is performed not only in standard conditions but also with a bath rich in sodium and with control of ultrafiltration.

  19. Characterization of the Natural Organic Matter (NOM) in groundwater contaminated with (60)Co and (137)Cs using ultrafiltration, Solid Phase Extraction and fluorescence analysis.

    PubMed

    Caron, François; Siemann, Stefan; Riopel, Rémi

    2014-12-01

    Spot samples of shallow groundwaters have been taken between the years 2004 and 2010 near a site formerly used for the dispersal of radioactive liquid wastes. Three sampling points, one clean (upstream), and two downstream of the contamination source, were processed by ultrafiltration (5000 Da cut-off) and Solid Phase Extraction (SPE) to determine the association of selected artificial radionuclides ((60)Co, (137)Cs) with Natural Organic Matter (NOM). The last two sampling episodes (2008 and 2010) also benefited from fluorescence analysis to determine the major character of the NOM. The fluorescence signals are reported as humic-like, fulvic-like and protein-like, which are used to characterize the different NOM types. The NOM from the clean site comprised mostly fine material, whereas the colloidal content (retained by ultrafiltration) was higher (e.g., 15-40% of the Total Organic Carbon - TOC). Most of the 137Cs was present in the colloidal fraction, whereas (60)Co was found in the filtered fraction. Fluorescence analysis, on the other hand, indicated a contrasting behavior between the clean and contaminated sites, with a dominance of protein-like material, a feature usually associated with human impacts. Finally, SPE removed almost quantitatively the protein-like material (>90%), whereas it removed a much smaller fraction of the (137)Cs (<28%). This finding indicates that the (137)Cs preferential binding occurs with a fraction other than the protein-like NOM, likely the fulvic-like or humic-like portion. PMID:24476752

  20. Rétention de sels simples par une membrane chargée d'ultrafiltration à base d'alumine gamma

    NASA Astrophysics Data System (ADS)

    Benalla, R.; Persin, M.; Toreis, N.; Sarrazin, J.; Larbot, A.; Bouhaouss, A.

    1999-09-01

    Filtration of different electrolytes solutions was performed by means of a γ alumina ultrafiltration membrane. The experimental determination of the rejection rate for the salts leads to their phenomenologic parameters σ and P. The observed rejection are in agreement with a Donnan mechanism of exclusion of the coion outside of the membrane pore. Une membrane d'ultrafiltration en alumine γ a été utilisée pour la filtration de différentes solutions salines. Les rétentions des différents sels ont été d'abord mesurées à l'aide de cette membrane puis les coefficients de réflexion σ et les perméabilités P pour chaque sel ont été déterminées. La rétention des sels peut être expliquée par un mécanisme d'exclusion de type Donnan.

  1. Characterization of the Natural Organic Matter (NOM) in groundwater contaminated with (60)Co and (137)Cs using ultrafiltration, Solid Phase Extraction and fluorescence analysis.

    PubMed

    Caron, François; Siemann, Stefan; Riopel, Rémi

    2014-12-01

    Spot samples of shallow groundwaters have been taken between the years 2004 and 2010 near a site formerly used for the dispersal of radioactive liquid wastes. Three sampling points, one clean (upstream), and two downstream of the contamination source, were processed by ultrafiltration (5000 Da cut-off) and Solid Phase Extraction (SPE) to determine the association of selected artificial radionuclides ((60)Co, (137)Cs) with Natural Organic Matter (NOM). The last two sampling episodes (2008 and 2010) also benefited from fluorescence analysis to determine the major character of the NOM. The fluorescence signals are reported as humic-like, fulvic-like and protein-like, which are used to characterize the different NOM types. The NOM from the clean site comprised mostly fine material, whereas the colloidal content (retained by ultrafiltration) was higher (e.g., 15-40% of the Total Organic Carbon - TOC). Most of the 137Cs was present in the colloidal fraction, whereas (60)Co was found in the filtered fraction. Fluorescence analysis, on the other hand, indicated a contrasting behavior between the clean and contaminated sites, with a dominance of protein-like material, a feature usually associated with human impacts. Finally, SPE removed almost quantitatively the protein-like material (>90%), whereas it removed a much smaller fraction of the (137)Cs (<28%). This finding indicates that the (137)Cs preferential binding occurs with a fraction other than the protein-like NOM, likely the fulvic-like or humic-like portion.

  2. Influence of Surface Properties of Filtration-Layer Metal Oxide on Ceramic Membrane Fouling during Ultrafiltration of Oil/Water Emulsion.

    PubMed

    Lu, Dongwei; Zhang, Tao; Gutierrez, Leo; Ma, Jun; Croué, Jean-Philippe

    2016-05-01

    In this work, ceramic ultrafiltration membranes deposited with different metal oxides (i.e., TiO2, Fe2O3, MnO2, CuO, and CeO2) of around 10 nm in thickness and similar roughness were tested for O/W emulsion treatment. A distinct membrane fouling tendency was observed, which closely correlated to the properties of the filtration-layer metal oxides (i.e., surface hydroxyl groups, hydrophilicity, surface charge, and adhesion energy for oil droplets). Consistent with the distinct bond strength of the surface hydroxyl groups, hydrophilicity of these common metal oxides is quite different. The differences in hydrophilicity consequently lead to different adhesion of these metal oxides toward oil droplets, consistent with the irreversible membrane fouling tendency. In addition, the surface charge of the metal oxide opposite to that of emulsion can help to alleviate irreversible membrane fouling in ultrafiltration. Highly hydrophilic Fe2O3 with the lowest fouling tendency could be a potential filtration-layer material for the fabrication/modification of ceramic membranes for O/W emulsion treatment. To the best of our knowledge, this is the first study clearly showing the correlations between surface properties of filtration-layer metal oxides and ceramic membrane fouling tendency by O/W emulsion.

  3. Ultrafiltration liquid chromatography combined with high-speed countercurrent chromatography for screening and isolating potential α-glucosidase and xanthine oxidase inhibitors from Cortex Phellodendri.

    PubMed

    Li, Sainan; Liu, Chunming; Guo, Liping; Zhang, Yuchi; Wang, Jing; Ma, Bing; Wang, Yueqi; Wang, Yumeng; Ren, Junqi; Yang, Xiaojing; Qin, Yao; Tang, Ying

    2014-09-01

    Cortex Phellodendri is a typical Chinese herb with a large number of alkaloids existing in all parts of it. The most common methods for screening and isolating alkaloids are mostly labor intensive and time consuming. In this study, a new assay based upon ultrafiltration liquid chromatography was developed for the rapid screening of ligands for α-glucosidase and xanthine oxidase. The C. Phellodendri extract was found to contain two alkaloids with both α-glucosidase- and xanthine oxidase binding activities and one lactone with α-glucosidase-binding activity. Subsequently, with the help of high-speed countercurrent chromatography, the specific binding ligands including palmatine, berberine, and obaculactone with purities of 97.38, 96.12, and 96.08%, respectively, were successfully separated. An optimized low-toxicity two-phase solvent system composed of ethyl acetate/n-butanol/ethanol/water (3.5:1.7:0.5:5, v/v/v/v) was used to isolate the three compounds mentioned above from C. Phellodendri. The targeted compounds were identified by liquid chromatography coupled with mass spectrometry and NMR spectroscopy. Therefore, ultrafiltration liquid chromatography combined with high-speed countercurrent chromatography is not only a powerful tool for screening and isolating α-glucosidase and xanthine oxidase inhibitors in complex samples but is also a useful platform for discovering bioactive compounds for the prevention and treatment of diabetes mellitus and gout.

  4. Influence of Surface Properties of Filtration-Layer Metal Oxide on Ceramic Membrane Fouling during Ultrafiltration of Oil/Water Emulsion.

    PubMed

    Lu, Dongwei; Zhang, Tao; Gutierrez, Leo; Ma, Jun; Croué, Jean-Philippe

    2016-05-01

    In this work, ceramic ultrafiltration membranes deposited with different metal oxides (i.e., TiO2, Fe2O3, MnO2, CuO, and CeO2) of around 10 nm in thickness and similar roughness were tested for O/W emulsion treatment. A distinct membrane fouling tendency was observed, which closely correlated to the properties of the filtration-layer metal oxides (i.e., surface hydroxyl groups, hydrophilicity, surface charge, and adhesion energy for oil droplets). Consistent with the distinct bond strength of the surface hydroxyl groups, hydrophilicity of these common metal oxides is quite different. The differences in hydrophilicity consequently lead to different adhesion of these metal oxides toward oil droplets, consistent with the irreversible membrane fouling tendency. In addition, the surface charge of the metal oxide opposite to that of emulsion can help to alleviate irreversible membrane fouling in ultrafiltration. Highly hydrophilic Fe2O3 with the lowest fouling tendency could be a potential filtration-layer material for the fabrication/modification of ceramic membranes for O/W emulsion treatment. To the best of our knowledge, this is the first study clearly showing the correlations between surface properties of filtration-layer metal oxides and ceramic membrane fouling tendency by O/W emulsion. PMID:27035544

  5. Effect of ultrafiltration on thermal variables, skin temperature, skin blood flow, and energy expenditure during ultrapure hemodialysis.

    PubMed

    van der Sande, Frank M; Rosales, Laura M; Brener, Zohar; Kooman, Jeroen P; Kuhlmann, Martin; Handelman, Garry; Greenwood, Roger N; Carter, Mary; Schneditz, Daniel; Leunissen, Karel M; Levin, Nathan W

    2005-06-01

    The cause of the increase in core temperature (CT) during hemodialysis (HD) is still under debate. It has been suggested that peripheral vasoconstriction as a result of hypovolemia, leading to a reduced dissipation of heat from the skin, is the main cause of this increase in CT. If so, then it would be expected that extracorporeal heat flow (Jex) needed to maintain a stable CT (isothermic; T-control = 0, no change in CT) is largely different between body temperature control HD combined with ultrafiltration (UF) and body temperature control HD without UF (isovolemic). Consequently, significant differences in DeltaCT would be expected between isovolemic HD and HD combined with UF at zero Jex (thermoneutral; E-control = 0, no supply or removal of thermal energy to and from the extracorporeal circulation). During the latter treatment, the CT is expected to increase. In this study, changes in thermal variables (CT and Jex), skin blood flow, energy expenditure, and cytokines (TNF-alpha, IL-1 receptor antagonist, and IL-6) were compared in 13 patients, each undergoing body temperature control (T-control = 0) HD without and with UF and energy-neutral (E-control = 0) HD without and with UF. CT increased equally during energy-neutral treatments, with (0.32 +/- 0.16 degrees C; P = 0.000) and without (0.27 +/- 0.29 degrees C; P = 0.006) UF. In body temperature control treatments, the relationship between Jex and UF tended to be significant (r = -0.51; P = 0.07); however, there was no significant difference in cooling requirements regardless of whether treatments were done without (-17.9 +/- 9.3W) or with UF (-17.8 +/- 13.27W). Changes in energy expenditure did not differ among the four treatment modes. There were no significant differences in pre- and postdialysis levels of cytokines within or between treatments. Although fluid removal has an effect on thermal variables, no single mechanism seems to be responsible for the increased heat accumulation during HD.

  6. Reactive iron sulfide (FeS)-supported ultrafiltration for removal of mercury (Hg(II)) from water.

    PubMed

    Han, Dong Suk; Orillano, Maria; Khodary, Ahmed; Duan, Yuhang; Batchelor, Bill; Abdel-Wahab, Ahmed

    2014-04-15

    This study investigated removal of Hg(II) from water using FeS(s) with batch and continuous contact filtration systems. For the batch system, kinetic experiments showed that removal of Hg(II) by FeS(s) was rapid at lower concentration (500 μM), but at higher concentration (1000 and 1250 μM), more time was required to achieve greater than 99% removal. The concentration of iron released to the solution remained relatively low, typically below 3 μM. This would theoretically present less than 1% of the Hg(II) removed. Thus, a simple exchange of Hg(II) for Fe(II) in the solid (FeS(s)) does not explain the results, but if the Fe(II) released could react to form another solids, low concentrations of Fe do not preclude a mechanism in which Hg(II) reacts to form HgS and release Fe(II). A continuous contact dead-end ultrafiltration (DE/UF) system was developed to treat water containing Hg(II) by applying a FeS(s) suspension with stirred or non-stirred modes. A major reason for applying stirring to the system was to investigate the role of "shear" flow in rejection of Hg(II)-contacted FeS(s) by a UF membrane and the stability of Hg on the FeS(s). The Hg(II)-contacted FeS(s) was completely rejected by the DE/UF system and mercury was strongly retained on the FeS(s) particles. Almost no release of Hg(II) (≈0 mM) from the FeS(s) solids was observed when they were contacted with 0.1M-thiosulfate, regardless of whether the system was operated in stirred or non-stirred mode. However, rapid oxidation of FeS(s) was observed in the stirred system but not in the non-stirred system. Determining the mechanism of oxidation requires further study, but it is important because oxidation reduces the ability of the solids to remove additional Hg(II).

  7. Combining cross flow ultrafiltration and diffusion gradients in thin-films approaches to determine trace metal speciation in freshwaters

    NASA Astrophysics Data System (ADS)

    Liu, Ruixia; Lead, Jamie R.; Zhang, Hao

    2013-05-01

    Cross flow ultrafiltration (CFUF) and diffusive gradients in thin films (DGT) with open pore gel (OP) and restricted pore gel (RP) were used to measure trace metal speciation in selected UK freshwaters. The proportions of metals present in particulate forms (>1 μm) varied widely between 40-85% Pb, 60-80% Al, 7-56% Mn, 10-49% Cu, 0-55% Zn, 20-38% Cr, 20-30% Fe, 6-25% Co, 5-22% Cd and <7% Ni. In the colloidal fraction (2 kDa-1 μm) values varied between 53-91% Pb, 33-55% Al, 21-55% Cu, 20-44% Fe, 34-36% Cr, 20-40% Cd, 7-28% Co and Ni, 2-32% Zn and <8% Mn. Wide variations were also observed in the ultrafiltered fraction (<2 kDa). These results indicated that colloids indeed influenced the occurrence and transport of Al, Fe, Cr, Co, Ni, Cu, Zn, Cr and Pb metals in rivers, while inorganic or organic colloids did not exert an important control on Mn transport in the selected freshwaters. Of total species, total labile metal measured by DGT-OP accounted for 1.4-50% for Al, Fe, Co, Ni, Cu, Cd and Pb in all selected waters. Of these metals total labile Pb concentration was the lowest with value less than 1.4% although this value slightly increased after deducting particulate fractions. In some waters, a majority of total Mn, Zn and Cr is DGT labile, in which the DGT labile Mn fraction accounted for 98-118% of the total dissolved phase. In most cases, the inorganic labile concentration measured by DGT-RP was lower than the total labile metal concentration. By the combination of CFUF and DGT techniques, the concentrations of total labile and inorganic labile metal species in CFUF-derived truly dissolved phase were measured in four water samples. 100% of ultrafiltered Mn species was found to be total DGT labile. The proportions of total labile metal species were lower than those of ultrafiltered fraction for Al, Fe, Co, Ni, Cu, Cd and Pb in all selected waters, and Cr and Zn in some cases, indicating a large amount of natural complexing ligands with smaller size for the

  8. Reactive iron sulfide (FeS)-supported ultrafiltration for removal of mercury (Hg(II)) from water.

    PubMed

    Han, Dong Suk; Orillano, Maria; Khodary, Ahmed; Duan, Yuhang; Batchelor, Bill; Abdel-Wahab, Ahmed

    2014-04-15

    This study investigated removal of Hg(II) from water using FeS(s) with batch and continuous contact filtration systems. For the batch system, kinetic experiments showed that removal of Hg(II) by FeS(s) was rapid at lower concentration (500 μM), but at higher concentration (1000 and 1250 μM), more time was required to achieve greater than 99% removal. The concentration of iron released to the solution remained relatively low, typically below 3 μM. This would theoretically present less than 1% of the Hg(II) removed. Thus, a simple exchange of Hg(II) for Fe(II) in the solid (FeS(s)) does not explain the results, but if the Fe(II) released could react to form another solids, low concentrations of Fe do not preclude a mechanism in which Hg(II) reacts to form HgS and release Fe(II). A continuous contact dead-end ultrafiltration (DE/UF) system was developed to treat water containing Hg(II) by applying a FeS(s) suspension with stirred or non-stirred modes. A major reason for applying stirring to the system was to investigate the role of "shear" flow in rejection of Hg(II)-contacted FeS(s) by a UF membrane and the stability of Hg on the FeS(s). The Hg(II)-contacted FeS(s) was completely rejected by the DE/UF system and mercury was strongly retained on the FeS(s) particles. Almost no release of Hg(II) (≈0 mM) from the FeS(s) solids was observed when they were contacted with 0.1M-thiosulfate, regardless of whether the system was operated in stirred or non-stirred mode. However, rapid oxidation of FeS(s) was observed in the stirred system but not in the non-stirred system. Determining the mechanism of oxidation requires further study, but it is important because oxidation reduces the ability of the solids to remove additional Hg(II). PMID:24530550

  9. ETV REPORT - PHYSICAL REMOVAL OF CRYPTOSPORIDIUM OOCYSTS AND GIARDIA CYSTS IN DRINKING WATER AQUASOURCE NORTH AMERICA ULTRAFILTRATION SYSTEM A35 AT PITTSBURGH, PA. - NSF00/07/EPADW395

    EPA Science Inventory

    Verification testing of the Aquasource Ultrafiltration Treatment System Model A35 was conducted from 12/1 - 12/31/98. The treatment system underwent microbial challenge testing on 1/22/99 and demonstrated a 5.5 log10 removal of Giardia cysts and a 6.5 log10 removal of Cryptospori...

  10. Determination of useful lifetime of immobilized beta-galactosidase for hydrolysis of lactose in permeate obtained from ultrafiltration of cottage cheese whey

    SciTech Connect

    Scott, T.C.; Hill, C.G. Jr.; Amundson, C.H.; Scott, C.D.

    1986-01-01

    Beta-galactosidase immobolized on a porous silica carrier was used to effect the hydrolysis of lactose in permeate that results from the ultrafiltration of cottage cheese whey. Results obtained from analyzing kinetics of the immobilized enzyme have led to the formulation of a model that can be used to assess catalyst performance when utilizing a specified reactor operating strategy. The model predicts a lifetime of 90 days for the catalyst bed when starting production at 30 degrees and maintaining a constant production rate by raising the operating temperature as a function of time-on-stream. The useful lifetime of the catalyst was not significantly affected by the extent of lactose conversion carried out in the reactor. This model has the potential for use in optimization of reactor operating conditions for industrial applications of the immobilized enzyme.

  11. Role of transparent exopolymer particles on membrane fouling in a full-scale ultrafiltration plant: feed parameter analysis and membrane autopsy.

    PubMed

    Discart, V; Bilad, M R; Van Nevel, S; Boon, N; Cromphout, J; Vankelecom, I F J

    2014-12-01

    Ultrafiltration (UF) is widely used for water purification, but membrane fouling remains an important issue. In this study, the role of transparent exopolymer particles (TEPs), recently put forward as possible major foulants, was investigated in the fouling process of a full-scale UF installation. Algae, TEPs and other parameters in the UF feed were monitored and correlated during an 8 months long full-scale operation. Results revealed a complex fouling mechanism involving interactions mainly between algae, Fe (flocculant) and TEPs. Algae related parameters rather that TEP concentrations correlated stronger with irreversible fouling rates, suggesting that the overall role of TEPs in membrane fouling seems limited for this application. Finally, membrane autopsy showed the formation of a thick Fe-rich fouling layer on top of the fouled membranes, which could mostly be removed via cleaning-in-place. It remained partly irremovable in the form of some Fe-organic complexes. PMID:25285761

  12. Effects of endogenous small molecular compounds on the rheological properties, texture and microstructure of soymilk coagulum: Removal of phytate using ultrafiltration.

    PubMed

    Wang, Ruican; Guo, Shuntang

    2016-11-15

    This study aims to clarify the roles played by endogenous small molecular components in soymilk coagulation process and the properties of gels. Soymilk samples with decreasing levels of small molecules were prepared by ultrafiltration, to reduce the amount of phytate and salts. CaSO4-induced coagulation process was analyzed using rheological methods. Results showed that removal of free small molecules decreased the activation energy of protein coagulation, resulting in accelerated reaction and increased gel strength. However, too fast a reaction led to the drop in storage modulus (G'). Microscopic observation suggested that accelerated coagulation generated a coarse and non-uniform gel network with large pores. This network could not hold much water, leading to serious syneresis. Endogenous small molecules in soymilk were vital in the fine gel structure. Coagulation rate could be controlled by adjusting the amount of small molecules to obtain tofu products with the optimal texture. PMID:27283662

  13. Screening of Potential Xanthine Oxidase Inhibitors in Gnaphalium hypoleucum DC. by Immobilized Metal Affinity Chromatography and Ultrafiltration-Ultra Performance Liquid Chromatography-Mass Spectrometry.

    PubMed

    Zhang, Hong-Jian; Hu, Yi-Juan; Xu, Pan; Liang, Wei-Qing; Zhou, Jie; Liu, Pei-Gang; Cheng, Lin; Pu, Jin-Bao

    2016-01-01

    In this study, a new method based on immobilized metal affinity chromatography (IMAC) combined with ultrafiltration-ultra performance liquid chromatography-mass spectrometry (UF-UPLC-MS) was developed for discovering ligands for xanthine oxidase (XO) in Gnaphalium hypoleucum DC., a folk medicine used in China for the treatment of gout. By IMAC, the high flavonoid content of G. hypoleucum could be determined rapidly and efficiently. UF-UPLC-MS was used to select the bound xanthine oxidase ligands in the mixture and identify them. Finally, two flavonoids, luteolin-4'-O-glucoside and luteolin, were successfully screened and identified as the candidate XO inhibitors of G. hypoleucum. They were evaluated in vitro for XO inhibitory activity and their interaction mechanism was studied coupled with molecular simulations. The results were in favor of the hypothesis that the flavonoids of G. hypoleucum might be the active content for gout treatment by inhibiting XO. PMID:27649136

  14. Water-soluble metal-binding polymers with ultrafiltration: A technology for the removal, concentration, and recovery of metal ions from aqueous streams

    SciTech Connect

    Smith, B.F.; Robison, T.W.; Jarvinen, G.D.

    1997-12-31

    The use of water-soluble metal-binding polymers coupled with ultrafiltration (UF) is a technology under development to selectively concentrate and recover valuable or regulated metal-ions from dilute process or waste waters. The polymers have a sufficiently large molecular size that they can be separated and concentrated using commercially available UF technology. The polymers can then be reused by changing the solution conditions to release the metal-ions, which are recovered in a concentrated form for recycle or disposal. Pilot-scale demonstrations have been completed for a variety of waste streams containing low concentrations of metal ions including electroplating wastes (zinc and nickel) and nuclear waste streams (plutonium and americium). Many other potential commercial applications exist including remediation of contaminated solids. An overview of both the pilot-scale demonstrated applications and small scale testing of this technology are presented.

  15. Electrocatalytic Oxidation of Formate with Nickel Diphosphane Dipeptide Complexes. Effect of Ligands Modified with Amino Acids

    SciTech Connect

    Galan, Brandon R.; Reback, Matthew L.; Jain, Avijita; Appel, Aaron M.; Shaw, Wendy J.

    2013-09-03

    A series of nickel bis-diphosphine complexes with dipeptides appended to the ligands were investigated for the catalytic oxidation of formate. Typical rates of ~7 s-1 were found, similar to the parent complex (~8 s-1), with amino acid size and positioning contributing very little to rate or operating potential. Hydroxyl functionalities did result in lower rates, which were recovered by protecting the hydroxyl group. The results suggest that the overall dielectric introduced by the dipeptides does not play an important role in catalysis, but free hydroxyl groups do influence activity suggesting contributions from intra- or intermolecular interactions. These observations are important in developing a fundamental understanding of the affect that an enzyme-like outer coordination sphere can have upon molecular catalysts. This work was funded by the US DOE Basic Energy Sciences, Chemical Sciences, Geoscience and Biosciences Division (BRG, AJ, AMA, WJS), the US DOE Basic Energy Sciences, Physical Bioscience program (MLR). Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

  16. Development of a rapid method for simultaneous recovery of diverse microbes in drinking water by ultrafiltration with sodium polyphosphate and surfactants.

    PubMed

    Hill, Vincent R; Polaczyk, Amy L; Hahn, Donghyun; Narayanan, Jothikumar; Cromeans, Theresa L; Roberts, Jacquelin M; Amburgey, James E

    2005-11-01

    The ability to simultaneously concentrate diverse microbes is an important consideration for sample collection methods that are used for emergency response and environmental monitoring when drinking water may be contaminated with an array of unknown microbes. This study focused on developing a concentration method using ultrafilters and different combinations of a chemical dispersant (sodium polyphosphate [NaPP]) and surfactants. Tap water samples were seeded with bacteriophage MS2, Escherichia coli, Enterococcus faecalis, Cryptosporidium parvum, 4.5-microm microspheres, Salmonella enterica serovar Typhimurium, Bacillus globigii endospores, and echovirus 1. Ten-liter tap water samples were concentrated to approximately 250 ml in 12 to 42 min, depending on the experimental condition. Initial experiments indicated that pretreating filters with fetal bovine serum or NaPP resulted in an increase in microbe recovery. The addition of NaPP to the tap water samples resulted in significantly higher microbe and microsphere recovery efficiencies. Backflushing of the ultrafilter was found to significantly improve recovery efficiencies. The effectiveness of backflushing was improved further with the addition of Tween 80 to the backflush solution. The ultrafiltration method developed in this study, incorporating the use of NaPP pretreatment and surfactant solution backflushing, was found to recover MS2, C. parvum, microspheres, and several bacterial species with mean recovery efficiencies of 70 to 93%. The mean recovery efficiency for echovirus 1 (49%) was the lowest of the microbes studied for this method. This research demonstrates that ultrafiltration can be effective for recovering diverse microbes simultaneously in tap water and that chemical dispersants and surfactants can be beneficial for improving microbial recovery using this technique.

  17. Removal of high-salinity matrices through polymer-complexation-ultrafiltration for the detection of trace levels of REEs using inductively coupled plasma mass spectrometry.

    PubMed

    Duan, Hualing; Lin, Jijun; Gong, Zhenbin; Huang, Jiahua; Yang, Shifeng

    2015-10-01

    The polymer-complexation-ultrafiltration (PCUF) technique was applied to separate trace levels of rare earth elements (REEs), including scandium, yttrium and the lanthanides, from high-salinity matrices prior to their determination by inductively coupled plasma mass spectrometry (ICP-MS). The REEs were converted into REE-polymer complexes using the water-soluble polymer polyacrylic acid (PAA) at a specified pH, retained on the ultrafiltration membrane of centrifugal filter units, and finally eluted using diluted nitric acid to achieve separation from matrices with relatively high levels of various inorganic ions, such as sodium, potassium, calcium, magnesium, and chlorine ions. Numerous factors affecting the PCUF efficiency were optimized. The optimal conditions included the addition of 30 mg L(-1) of PAA, a pH of 7.5, a reaction time of 40 min at room temperature, and 5.0 mL of 3% nitric acid (v/v) eluent. Under these conditions, the analytes were quantitatively separated and recovered, with a resulting relative standard deviation (RSD) of less than 4.0% (0.05 µg L(-1), n=5) and standard addition recoveries between 89.2% (La) and 95.8% (Sm) for matrices of various salinities. The blank samples for the method ranged from 0.0003 µg L(-1) (Dy) to 0.0031 µg L(-1) (Sc), and the limits of quantification (LOQs, 10σ) were between 0.0006 µg L(-1) (Dy) and 0.0026 µg L(-1) (Sc). Furthermore, the salinity of the sample exhibited no effect on the REE-polymer complex formation process. Finally, the method was successfully applied for the determination of trace levels of dissolved Sc, Y, and lanthanides in coastal and estuarine seawater samples. PMID:26078161

  18. Mixed Matrix PVDF Membranes With in Situ Synthesized PAMAM Dendrimer-Like Particles: A New Class of Sorbents for Cu(II) Recovery from Aqueous Solutions by Ultrafiltration.

    PubMed

    Kotte, Madhusudhana Rao; Kuvarega, Alex T; Cho, Manki; Mamba, Bhekie B; Diallo, Mamadou S

    2015-08-18

    Advances in industrial ecology, desalination, and resource recovery have established that industrial wastewater, seawater, and brines are important and largely untapped sources of critical metals and elements. A Grand Challenge in metal recovery from industrial wastewater is to design and synthesize high capacity, recyclable and robust chelating ligands with tunable metal ion selectivity that can be efficiently processed into low-energy separation materials and modules. In our efforts to develop high capacity chelating membranes for metal recovery from impaired water, we report a one-pot method for the preparation of a new family of mixed matrix polyvinylidene fluoride (PVDF) membranes with in situ synthesized poly(amidoamine) [PAMAM] particles. The key feature of our new membrane preparation method is the in situ synthesis of PAMAM dendrimer-like particles in the dope solutions prior to membrane casting using low-generation dendrimers (G0 and G1-NH2) with terminal primary amine groups as precursors and epichlorohydrin (ECH) as cross-linker. By using a combined thermally induced phase separation (TIPS) and nonsolvent induced phase separation (NIPS) casting process, we successfully prepared a new family of asymmetric PVDF ultrafiltration membranes with (i) neutral and hydrophilic surface layers of average pore diameters of 22-45 nm, (ii) high loadings (∼48 wt %) of dendrimer-like PAMAM particles with average diameters of ∼1.3-2.4 μm, and (iii) matrices with sponge-like microstructures characteristics of membranes with strong mechanical integrity. Preliminary experiments show that these new mixed matrix PVDF membranes can serve as high capacity sorbents for Cu(II) recovery from aqueous solutions by ultrafiltration.

  19. Uranium aqueous speciation in the vicinity of the former uranium mining sites using the diffusive gradients in thin films and ultrafiltration techniques.

    PubMed

    Drozdzak, Jagoda; Leermakers, Martine; Gao, Yue; Elskens, Marc; Phrommavanh, Vannapha; Descostes, Michael

    2016-03-24

    The performance of the Diffusive Gradients in Thin films (DGT) technique with Chelex(®)-100, Metsorb™ and Diphonix(®) as binding phases was evaluated in the vicinity of the former uranium mining sites of Chardon and L'Ecarpière (Loire-Atlantique department in western France). This is the first time that the DGT technique with three different binding agents was employed for the aqueous U determination in the context of uranium mining environments. The fractionation and speciation of uranium were investigated using a multi-methodological approach using filtration (0.45 μm, 0.2 μm), ultrafiltration (500 kDa, 100 kDa and 10 kDa) coupled to geochemical speciation modelling (PhreeQC) and the DGT technique. The ultrafiltration data showed that at each sampling point uranium was present mostly in the 10 kDa truly dissolved fraction and the geochemical modelling speciation calculations indicated that U speciation was markedly predominated by CaUO2(CO3)3(2-). In natural waters, no significant difference was observed in terms of U uptake between Chelex(®)-100 and Metsorb™, while similar or inferior U uptake was observed on Diphonix(®) resin. In turn, at mining influenced sampling spots, the U accumulation on DGT-Diphonix(®) was higher than on DGT-Chelex(®)-100 and DGT-Metsorb™, probably because their performance was disturbed by the extreme composition of the mining waters. The use of Diphonix(®) resin leads to a significant advance in the application and development of the DGT technique for determination of U in mining influenced environments. This investigation demonstrated that such multi-technique approach provides a better picture of U speciation and enables to assess more accurately the potentially bioavailable U pool. PMID:26944993

  20. Mixed Matrix PVDF Membranes With in Situ Synthesized PAMAM Dendrimer-Like Particles: A New Class of Sorbents for Cu(II) Recovery from Aqueous Solutions by Ultrafiltration.

    PubMed

    Kotte, Madhusudhana Rao; Kuvarega, Alex T; Cho, Manki; Mamba, Bhekie B; Diallo, Mamadou S

    2015-08-18

    Advances in industrial ecology, desalination, and resource recovery have established that industrial wastewater, seawater, and brines are important and largely untapped sources of critical metals and elements. A Grand Challenge in metal recovery from industrial wastewater is to design and synthesize high capacity, recyclable and robust chelating ligands with tunable metal ion selectivity that can be efficiently processed into low-energy separation materials and modules. In our efforts to develop high capacity chelating membranes for metal recovery from impaired water, we report a one-pot method for the preparation of a new family of mixed matrix polyvinylidene fluoride (PVDF) membranes with in situ synthesized poly(amidoamine) [PAMAM] particles. The key feature of our new membrane preparation method is the in situ synthesis of PAMAM dendrimer-like particles in the dope solutions prior to membrane casting using low-generation dendrimers (G0 and G1-NH2) with terminal primary amine groups as precursors and epichlorohydrin (ECH) as cross-linker. By using a combined thermally induced phase separation (TIPS) and nonsolvent induced phase separation (NIPS) casting process, we successfully prepared a new family of asymmetric PVDF ultrafiltration membranes with (i) neutral and hydrophilic surface layers of average pore diameters of 22-45 nm, (ii) high loadings (∼48 wt %) of dendrimer-like PAMAM particles with average diameters of ∼1.3-2.4 μm, and (iii) matrices with sponge-like microstructures characteristics of membranes with strong mechanical integrity. Preliminary experiments show that these new mixed matrix PVDF membranes can serve as high capacity sorbents for Cu(II) recovery from aqueous solutions by ultrafiltration. PMID:26222014

  1. Uranium aqueous speciation in the vicinity of the former uranium mining sites using the diffusive gradients in thin films and ultrafiltration techniques.

    PubMed

    Drozdzak, Jagoda; Leermakers, Martine; Gao, Yue; Elskens, Marc; Phrommavanh, Vannapha; Descostes, Michael

    2016-03-24

    The performance of the Diffusive Gradients in Thin films (DGT) technique with Chelex(®)-100, Metsorb™ and Diphonix(®) as binding phases was evaluated in the vicinity of the former uranium mining sites of Chardon and L'Ecarpière (Loire-Atlantique department in western France). This is the first time that the DGT technique with three different binding agents was employed for the aqueous U determination in the context of uranium mining environments. The fractionation and speciation of uranium were investigated using a multi-methodological approach using filtration (0.45 μm, 0.2 μm), ultrafiltration (500 kDa, 100 kDa and 10 kDa) coupled to geochemical speciation modelling (PhreeQC) and the DGT technique. The ultrafiltration data showed that at each sampling point uranium was present mostly in the 10 kDa truly dissolved fraction and the geochemical modelling speciation calculations indicated that U speciation was markedly predominated by CaUO2(CO3)3(2-). In natural waters, no significant difference was observed in terms of U uptake between Chelex(®)-100 and Metsorb™, while similar or inferior U uptake was observed on Diphonix(®) resin. In turn, at mining influenced sampling spots, the U accumulation on DGT-Diphonix(®) was higher than on DGT-Chelex(®)-100 and DGT-Metsorb™, probably because their performance was disturbed by the extreme composition of the mining waters. The use of Diphonix(®) resin leads to a significant advance in the application and development of the DGT technique for determination of U in mining influenced environments. This investigation demonstrated that such multi-technique approach provides a better picture of U speciation and enables to assess more accurately the potentially bioavailable U pool.

  2. A mass balance approach for calculation of recovery and binding enables the use of ultrafiltration as a rapid method for measurement of plasma protein binding for even highly lipophilic compounds

    PubMed Central

    Wang, Changguang; Williams, Noelle S.

    2012-01-01

    The aim of this study is to further validate the use of ultrafiltration (UF) as a method for determining plasma protein binding (PPB) by demonstrating that non-specific binding (NSB) is not a limitation, even for highly lipophilic compounds, because NSB sites on the apparatus are passivated in the presence of plasma. Mass balance theory was used to calculate recovery of 20 commercial and seven investigational compounds during ultrafiltration in the presence and absence of plasma. PPB was also measured using this mass balance approach for comparison to PPB determined by rapid equilibrium dialysis (RED) and as found in the literature. Compound recovery during UF was dramatically different in the presence and absence of plasma for compounds with high NSB in PBS only. A comparison of PPB calculated by ultrafiltration with literature values or calculated by RED gave concordant results. Discrepancies could be explained by changes in pH, insufficient time to equilibrium, or compound instability during RED, problems which were circumvented by ultrafiltration. Therefore, NSB, as measured by the traditional incubation of compound in PBS, need not be an issue when choosing UF as a PPB assay method. It is more appropriate to calculate compound recovery from the device in plasma as measured by mass balance to determine the suitability of the method for an individual compound. The speed with which UF can be conducted additionally avoids changes in pH or compound loss that can occur with other methods. The mass balance approach to UF is thus a preferred method for rapid determination of PPB. PMID:23312388

  3. An In-Vitro Comparison between Hemobag® and Non-Hemobag® Ultrafiltration Methods of Salvaging Circuit Blood Following Cardiopulmonary Bypass

    PubMed Central

    Delaney, Ed; Rosinski, David; Ellis, Harvey; Samolyk, Keith A.; Riley, Jeffrey B.

    2010-01-01

    Abstract: Ultrafiltration of the residual cardiopulmonary bypass circuit blood has become one of the most advantageous procedures to maximize autologous whole blood recovery and coagulation management in cardiovascular surgery. In this invitro study, the Hemobag® technique (HB) was compared to the most common non-Hemobag® method (NHB) of hemoconcentrating residual circuit blood. The residual bovine blood from 10 identical extracorporeal circuits was processed by the recirculating HB technique or by a venous reservoir NHB concentration method. Blood component concentrations and hemolysis levels were measured before and after processing. The HB method yielded significantly higher hemoglobin, hematocrit, fibrinogen, albumin, and total protein levels in the final product. There was no significant difference in final product platelet and white blood cell counts, or hemolysis index. HB processing times were substantially shorter at all residual circuit volumes tested. The HB technique resulted in significantly less wasted red blood cells at the end of processing. The recirculating HB method to process residual extracorporeal circuit blood is consistent and superior to the most common single pass concentrating method. PMID:20648897

  4. Behavior of pharmaceuticals and drugs of abuse in a drinking water treatment plant (DWTP) using combined conventional and ultrafiltration and reverse osmosis (UF/RO) treatments.

    PubMed

    Boleda, M A Rosa; Galceran, M A Teresa; Ventura, Francesc

    2011-06-01

    The behavior along the potabilization process of 29 pharmaceuticals and 12 drugs of abuse identified from a total of 81 compounds at the intake of a drinking water treatment plant (DWTP) has been studied. The DWTP has a common treatment consisting of dioxychlorination, coagulation/flocculation and sand filtration and then water is splitted in two parallel treatment lines: conventional (ozonation and carbon filtration) and advanced (ultrafiltration and reverse osmosis) to be further blended, chlorinated and distributed. Full removals were reached for most of the compounds. Iopromide (up to 17.2 ng/L), nicotine (13.7 ng/L), benzoylecgonine (1.9 ng/L), cotinine (3.6 ng/L), acetaminophen (15.6 ng/L), erythromycin (2.0 ng/L) and caffeine (6.0 ng/L) with elimination efficiencies ≥ 94%, were the sole compounds found in the treated water. The advanced treatment process showed a slightly better efficiency than the conventional treatment to eliminate pharmaceuticals and drugs of abuse.

  5. Integrated in-line coagulation-aerated ultrafiltration for drinking-water production: A case study from laboratory to pilot plant.

    PubMed

    Rojas-Serrano, Fátima; Pérez, Jorge I; Gómez, Miguel A

    2015-01-01

    A pilot-scale study was made for drinking-water production from low-quality influents with in-line coagulation as pre-treatment of aerated ultrafiltration. Optimum flocculation parameters were previously determined in the laboratory, searching for large and strong flocs that could resist aeration without increasing the membrane fouling. Nevertheless, the comparison of the jar tests and the pilot-scale results showed that the former could help pre-dimensioning the flocculation facilities but could not precisely reproduce the behavior of the flocs in the membrane tank. The optimum coagulant dosage enabled the highest dissolved organic carbon (DOC) removal without affecting membrane fouling. Additionally, as opposed to the jar-test results, long retention times led to the lowest fouling rates while the velocity gradient affected neither the effluent quality nor the membrane fouling. These findings suggested that the influence of the flocculation parameters was masked by aeration inside the membrane tank but, even so, 43% and 82% DOC and UVA254 removals, respectively, were reached. Furthermore, the growth of the total membrane resistance with time was logarithmic instead of linear, confirming the suitability of the pre-treatment for low-quality influents.

  6. Dual layer hollow fiber PVDF ultra-filtration membranes containing Ag nano-particle loaded zeolite with longer term anti-bacterial capacity in salt water.

    PubMed

    Shi, Huyan; Xue, Lixin; Gao, Ailin; Zhou, Qingbo

    2016-01-01

    Dual layer polyvinylidene fluoride (PVDF), antibacterial, hollow fiber, ultra-filtration composite membranes with antibacterial particles (silver (Ag) nano-particles loaded zeolite (Z-Ag)) in the outer layer were prepared with high water flux and desired pore sizes. The amounts of Ag(+) released from the composite membranes, freshly made and stored in water and salt solution, were measured. The result indicated that dual layer PVDF antibacterial hollow fiber containing Z-Ag (M-1-Ag) still possessed the ability of continuous release of Ag(+) even after exposure to water with high ionic content, showing a longer term resistance to bacterial adhesion and antibacterial activity than membrane doped with Z-Ag(+) (M-1). Results from an anti-adhesion and bacteria killing test with Escherichia coli supported that the antibacterial efficiency of dual hollow fiber PVDF membranes with Z-Ag was much higher than those with Z-Ag(+) after long time storage in water or exposure to phosphate buffered saline (PBS) solution. This novel hollow fiber membrane may find applications in constructing sea water pretreatment devices with long term antifouling capability for the desalination processes.

  7. Effect of hydraulically reversible and hydraulically irreversible fouling on the removal of MS2 and φX174 bacteriophage by an ultrafiltration membrane.

    PubMed

    ElHadidy, Ahmed M; Peldszus, Sigrid; Van Dyke, Michele I

    2014-09-15

    The effect of membrane fouling on the removal of enteric virus surrogates MS2 and φX174 bacteriophage by an ultrafiltration membrane was assessed under simulated full-scale drinking water treatment operating conditions. Filtration experiments of up to 8 days using either river or lake water ascertained how the membrane fouling layer affected virus removal. Organic carbon fractionation techniques identified potential foulants, including biopolymers, in the feed water and in the permeate. Hydraulically irreversible fouling could greatly improve the removal of both viruses at moderate and severe fouling conditions by up to 2.5 logs. Hydraulically reversible fouling increased virus removal only slightly, and increased removal of >0.5 log for both phage were only obtained under severe fouling conditions. The increase in virus removal due to irreversible and reversible fouling differed between the two water sources. As the degree of fouling increased, differences between the removal of the two phage decreased. Maintenance cleaning partially removed membrane foulants, however virus removal following maintenance cleaning was lower than that of the fouled membrane, it remained higher than that of the clean membrane.

  8. Isolation of α-Amylase Inhibitors from Kadsura longipedunculata Using a High-Speed Counter-Current Chromatography Target Guided by Centrifugal Ultrafiltration with LC-MS.

    PubMed

    Cen, Yin; Xiao, Aiping; Chen, Xiaoqing; Liu, Liangliang

    2016-01-01

    In this study, a high-speed counter-current chromatography (HSCCC) separation method target guided by centrifugal ultrafiltration with high-performance liquid chromatography-mass spectrometry (CU-LC-MS) was proposed. This method was used to analyze α-amylase inhibitors from Kadsura longipedunculata extract. According to previous screening with CU-LC-MS, two screened potential α-amylase inhibitors was successfully isolated from Kadsura longipedunculata extract using HSCCC under the optimized experimental conditions. The isolated two target compounds (with purities of 92.3% and 94.6%) were, respectively, identified as quercetin-3-O-rhamnoside (1) and protocatechuic acid (2) based on the MS, UV, and ¹H-NMR spectrometry data. To verify the inhibition of screened compounds, the inhibitory activities of quercetin-3-O-rhamnoside (1) and protocatechuic acid (2) on α-amylase were tested, and it demonstrated that the experimental IC50 values of quercetin-3-O-rhamnoside (1) and protocatechuic acid (2) were 28.8 and 12.5 μmol/L. These results proved that the hyphenated technique using CU-LC-MS and HSCCC was a rapid, competent, and reproductive method to screen and separate potential active compounds, like enzyme inhibitors from the extract of herbal medicines.

  9. Production of Chondroitin Sulphate from Head, Skeleton and Fins of Scyliorhinus canicula By-Products by Combination of Enzymatic, Chemical Precipitation and Ultrafiltration Methodologies

    PubMed Central

    Blanco, María; Fraguas, Javier; Sotelo, Carmen G.; Pérez-Martín, Ricardo I.; Vázquez, José Antonio

    2015-01-01

    This study illustrates the optimisation of the experimental conditions of three sequential steps for chondroitin sulphate (CS) recovery from three cartilaginous materials of Scyliorhinus canicula by-products. Optimum conditions of temperature and pH were first obtained for alcalase proteolysis of head cartilage (58 °C/pH 8.5/0.1% (v/w)/10 h of hydrolysis). Then, similar optimal conditions were observed for skeletons and fin materials. Enzymatic hydrolysates were subsequently treated with a combination of alkaline hydroalcoholic saline solutions in order to improve the protein hydrolysis and the selective precipitation of CS. Ranges of 0.53–0.64 M (NaOH) and 1.14–1.20 volumes (EtOH) were the levels for optimal chemical treatment depending on the cartilage origin. Finally, selective purification and concentration of CS and protein elimination of samples obtained from chemical treatment, was assessed by a combination of ultrafiltration and diafiltration (UF-DF) techniques at 30 kDa. PMID:26023837

  10. Comparison of two treatments for the removal of selected organic micropollutants and bulk organic matter: conventional activated sludge followed by ultrafiltration versus membrane bioreactor.

    PubMed

    Sahar, E; Ernst, M; Godehardt, M; Hein, A; Herr, J; Kazner, C; Melin, T; Cikurel, H; Aharoni, A; Messalem, R; Brenner, A; Jekel, M

    2011-01-01

    The potential of membrane bioreactor (MBR) systems to remove organic micropollutants was investigated at different scales, operational conditions, and locations. The effluent quality of the MBR system was compared with that of a plant combining conventional activated sludge (CAS) followed by ultrafiltration (UF). The MBR and CAS-UF systems were operated and tested in parallel. An MBR pilot plant in Israel was operated for over a year at a mixed liquor suspended solids (MLSS) range of 2.8-10.6 g/L. The MBR achieved removal rates comparable to those of a CAS-UF plant at the Tel-Aviv wastewater treatment plant (WWTP) for macrolide antibiotics such as roxythromycin, clarithromycin, and erythromycin and slightly higher removal rates than the CAS-UF for sulfonamides. A laboratory scale MBR unit in Berlin - at an MLSS of 6-9 g/L - showed better removal rates for macrolide antibiotics, trimethoprim, and 5-tolyltriazole compared to the CAS process of the Ruhleben sewage treatment plant (STP) in Berlin when both were fed with identical quality raw wastewater. The Berlin CAS exhibited significantly better benzotriazole removal and slightly better sulfamethoxazole and 4-tolyltriazole removal than its MBR counterpart. Pilot MBR tests (MLSS of 12 g/L) in Aachen, Germany, showed that operating flux significantly affected the resulting membrane fouling rate, but the removal rates of dissolved organic matter and of bisphenol A were not affected. PMID:21330721

  11. Ultrafiltration coupled with high-performance liquid chromatography and quadrupole-time-of-flight mass spectrometry for screening lipase binders from different extracts of Dendrobium officinale.

    PubMed

    Tao, Yi; Cai, Hao; Li, Weidong; Cai, Baochang

    2015-08-01

    Pancreatic lipase plays essential roles in the digestion, transport, and processing of dietary lipids in humans. Inhibition of pancreatic lipase leading to the decrease of lipid absorption may be used for treating obesity. In the present study, a new approach of ultrafiltration coupled with high-performance liquid chromatography and quadrupole-time-of-flight mass spectrometry was established for rapidly detecting lipase binders from different extracts of medicinal plants. Rutin, a model inhibitor of lipase, was selected to optimize the screening conditions, including ion strength, temperature, pH, and incubation time. Meanwhile, the specificity of the approach was investigated by using denatured lipase and inactive compound emodin. The optimal screening conditions were as follows: ion strength 75 mM, temperature 37 °C, pH 7.4, and incubation time 10 min. Furthermore, linearity, accuracy, precision, and matrix effect of the approach were well validated. Finally, lipase binders were screened from different extracts of Dendrobium officinale by applying the established approach and were subsequently subjected to traditional lipase inhibitory assay. Eleven lipase inhibitors were identified, eight of which, namely naringenine, vicenin II, schaftoside, isoschaftoside, isoquercetrin, kaempferol 3-O-β-D-glucopyranoside, vitexin 2″-O-glucoside, and vitexin 2″-O-rhamnoside, were reported for the first time. In addition, docking experiments were performed to determine the preferred binding sites of these new lipase inhibitors. PMID:26018630

  12. Ultrafiltration membrane fouling by extracellular organic matters (EOM) of Microcystis aeruginosa in stationary phase: influences of interfacial characteristics of foulants and fouling mechanisms.

    PubMed

    Qu, Fangshu; Liang, Heng; Wang, Zhaozhi; Wang, Hui; Yu, Huarong; Li, Guibai

    2012-04-01

    This paper focused on the membrane fouling caused by extracellular organic matters (EOM) which was extracted from lab-cultured Microcystis aeruginosa in stationary phase. The characteristics of EOM such as molecular weight distribution, hydrophobicity and fluorescence were measured. It was found that high molecular weight (MW) and hydrophilic organics accounted for the major parts of algal EOM which was comprised of protein-like, polysaccharide-like and humic-like substances. Ultrafiltration (UF) experiments were carried out in a stirring cell and hydrophobic polyethersulfone (PES) membranes which carried negative charge were used. Prefiltration, calcium addition and XAD fractionation were employed to change the interfacial characteristics of EOM. Then the effects of these interfacial characteristics on flux decline, reversibility and mass balance of organics were compared. Algal EOM proved to cause serious membrane fouling during UF. The fraction of algal EOM between 0.45 μm and 100 kDa contributed a significant portion of the fouling. Hydrophobic organics in EOM tended to adhere to membrane surface causing irreversible fouling, while the cake layer formed by hydrophilic organics caused greater resistance to water flow due to hydrophilic interaction such as hydrogen bond and led to faster flux decline during UF. The results also indicated that the algal EOM was negatively charged and the electrostatic repulsion could prevent organics from adhering to membrane surface. In term of fouling mechanisms, cake layer formation, hydrophobic adhesion and pore plugging were the main mechanisms for membrane fouling caused by algal EOM. PMID:22178303

  13. Parameter Identification of an Ultrafiltration Model for Organics Removal in a Full-Scale Wastewater Reclamation Plant with Sparse and Incomplete Monitoring Data.

    PubMed

    Sun, Fu; Zeng, Siyu; Huang, Yunqing; He, Miao

    2016-01-01

    Ultrafiltration (UF) has become one of the dominant treatment processes for wastewater reclamation in China. Modeling is an effective instrument to understand and optimize UF systems. To this end, a previously developed UF model for organics removal was applied to the UF process in a typical, full-scale wastewater reclamation plant (WRP) in China. However, the sparse and incomplete field monitoring data from the studied WRP made the traditional model analysis approaches hardly work in this case. Therefore, two strategies, namely Strategy 1 and Strategy 2, were proposed, following a regional sensitivity analysis approach, for model parameter identification. Strategy 1 aimed to identify the model parameters and the missing model input, i.e. sampling times, simultaneously, while Strategy 2 tried to separate these two processes to reduce the dimension of the identification problem through an iteration procedure. With these two strategies, the model performed well in the Qinghe WRP with the absolute relative errors between the simulated and observed total organic carbon (TOC) generally below 10%. The four model parameters were all sensitive and identifiable, and even the sampling times could be roughly identified. Given the incomplete model input, these results were encouraging and added to the trustworthiness of model when it was applied to the Qinghe WRP.

  14. F and H Area Effluent Treatment Facility (F/H ETF): ultrafiltration and hyperfiltration systems testing at Carre, Inc. with simulated F and H area effluents

    SciTech Connect

    Ryan, J.P.

    1984-05-23

    The F and H Area Effluent Treatment Facility is essentially a four-stage process that will decontaminate the waste water that is currently being discharged to seepage basins in the Separations Areas. The stages include pretreatment, reverse osmosis, ion exchange, and evaporation. A series of tests were performed at Carre, Inc. (Seneca, SC) from March 5 through March 13, to determine the usefulness of ultrafiltration (UF) in the pretreatment stage of the ETF. The results of that testing program indicate that UF would be an excellent means of removing entrained activity from the 200 Area process effluents. Hyperfiltration (HF) was also tested as a means of providing an improved concentration factor from the reverse osmosis stage. The results show that the membranes that were tested would not reject salt well enough at high salt concentrations to be useful in the final reverse osmosis stage. However, there are several membranes which are commercially available that would provide the needed rejection if they could be applied (dynamically) on the Carre support structure. This avenue is still being explored, as theoretically, it could eliminate the need for the F/H ETF evaporator.

  15. Investigation of the pore structure and morphology of cellulose acetate membranes using small-angle neutron scattering. 2: Ultrafiltration and reverse-osmosis membranes

    SciTech Connect

    Kulkarni, S.; Krause, S. ); Wignall, G.D. . Solid State Div.)

    1994-11-07

    Pore structure in cellulose acetate ultrafiltration (UF) and reverse-osmosis (RO) membranes has been studied using small-angle neutron scattering. Scattering experiments were carried out on dry membranes as well as on membranes swollen with deuterated solvents (D[sub 2]O and CD[sub 3]OD). In addition, the RO membranes were studied both before and after annealing (a process of heating a membrane in a water bath at [approximately]75 C to improve its separation properties). The pore surface in UF membranes was found to be smooth and nonfractal, as evidenced by the fourth power law behavior at high Q. Values of average pore sizes obtained for dry and solvent swollen membranes agree well with pore sizes obtained by other methods. For cellulose acetate RO membranes in their dry state, the unannealed membrane appears to consist of two discrete pore size distributions in the intermediate and high Q region while the annealed membrane contains a much wider distribution of pore sizes. These results give a good account of the changes occurring in the structure of RO membranes as a result of annealing, and agree well with the prediction of other authors.

  16. Impact of temperature on feed-flow characteristics and filtration performance of an upflow anaerobic sludge blanket coupled ultrafiltration membrane treating municipal wastewater.

    PubMed

    Ozgun, Hale; Tao, Yu; Ersahin, Mustafa Evren; Zhou, Zhongbo; Gimenez, Juan B; Spanjers, Henri; van Lier, Jules B

    2015-10-15

    The objective of this study was to assess the operational feasibility of an anaerobic membrane bioreactor (AnMBR), consisting of an upflow anaerobic sludge blanket (UASB) reactor coupled to an ultrafiltration membrane unit, at two operational temperatures (25°C and 15°C) for the treatment of municipal wastewater. The results showed that membrane fouling at 15°C was more severe than that at 25°C. Higher chemical oxygen demand (COD) and soluble microbial products (SMP) concentrations, lower mean particle diameter, and higher turbidity in the UASB effluent at lower temperature aggravated membrane fouling compared to the 25°C operation. However, the overall AnMBR treatment performance was not significantly affected by temperature, which was attributed to the physical membrane barrier. Cake resistance was found responsible for over 40% of the total fouling in both cases. However, an increase was observed in the contribution of pore blocking resistance at 15°C related to the larger amount of fine particles in the UASB effluent compared to 25°C. Based on the overall results, it is concluded that an AnMBR, consisting of a UASB coupled membrane unit, is not found technically feasible for the treatment of municipal wastewater at 15°C, considering the rapid deterioration of the filtration performance. PMID:26141423

  17. Pilot-scale study on the treatment of basal aquifer water using ultrafiltration, reverse osmosis and evaporation/crystallization to achieve zero-liquid discharge.

    PubMed

    Loganathan, Kavithaa; Chelme-Ayala, Pamela; Gamal El-Din, Mohamed

    2016-01-01

    Basal aquifer water is deep groundwater found at the bottom of geological formations, underlying bitumen-saturated sands. Some of the concerns associated with basal aquifer water at the Athabasca oil sands are the high concentrations of hardness-causing compounds, alkalinity, and total dissolved solids. The objective of this pilot-scale study was to treat basal aquifer water to a quality suitable for its reuse in the production of synthetic oil. To achieve zero-liquid discharge (ZLD) conditions, the treatment train included chemical oxidation, polymeric ultrafiltration (UF), reverse osmosis (RO), and evaporation-crystallization technologies. The results indicated that the UF unit was effective in removing solids, with UF filtrate turbidity averaging 2.0 NTU and silt density index averaging 0.9. Membrane autopsies indicated that iron was the primary foulant on the UF and RO membranes. Laboratory and pilot-scale tests on RO reject were conducted to determine the feasibility of ZLD crystallization. Due to the high amounts of calcium, magnesium, and bicarbonate in the RO reject, softening of the feed was required to avoid scaling in the evaporator. Crystals produced throughout the testing were mainly sodium chloride. The results of this study indicated that the ZLD approach was effective in both producing freshwater and minimizing brine discharges.

  18. Parameter Identification of an Ultrafiltration Model for Organics Removal in a Full-Scale Wastewater Reclamation Plant with Sparse and Incomplete Monitoring Data.

    PubMed

    Sun, Fu; Zeng, Siyu; Huang, Yunqing; He, Miao

    2016-01-01

    Ultrafiltration (UF) has become one of the dominant treatment processes for wastewater reclamation in China. Modeling is an effective instrument to understand and optimize UF systems. To this end, a previously developed UF model for organics removal was applied to the UF process in a typical, full-scale wastewater reclamation plant (WRP) in China. However, the sparse and incomplete field monitoring data from the studied WRP made the traditional model analysis approaches hardly work in this case. Therefore, two strategies, namely Strategy 1 and Strategy 2, were proposed, following a regional sensitivity analysis approach, for model parameter identification. Strategy 1 aimed to identify the model parameters and the missing model input, i.e. sampling times, simultaneously, while Strategy 2 tried to separate these two processes to reduce the dimension of the identification problem through an iteration procedure. With these two strategies, the model performed well in the Qinghe WRP with the absolute relative errors between the simulated and observed total organic carbon (TOC) generally below 10%. The four model parameters were all sensitive and identifiable, and even the sampling times could be roughly identified. Given the incomplete model input, these results were encouraging and added to the trustworthiness of model when it was applied to the Qinghe WRP. PMID:27529845

  19. Contribution of effluent organic matter (EfOM) to ultrafiltration (UF) membrane fouling: isolation, characterization, and fouling effect of EfOM fractions.

    PubMed

    Zheng, Xing; Khan, Muhammad Tariq; Croué, Jean-Philippe

    2014-11-15

    EfOM has been regarded as a major organic foulant resulting in UF membrane fouling in wastewater reclamation. To investigate fouling potential of different EfOM fractions, the present study isolated EfOM into hydrophobic neutrals (HPO-N), colloids, hydrophobic acids (HPO-A), transphilic neutrals and acids (TPI), and hydrophilics (HPI), and tested their fouling effect in both salt solution and pure water during ultrafiltration (UF). Major functional groups and chemical structure of the isolates were identified using Fourier transform infrared spectroscopy (FT-IR) and solid-state carbon nuclear magnetic resonance ((13)C NMR) analysis. The influence of the isolation process on the properties of EfOM fractions was minor because the raw and reconstituted secondary effluents were found similar with respect to UV absorbance, molecular size distribution, and fluorescence character. In membrane filtration tests, unified membrane fouling index (UMFI) and hydraulic resistance were used to quantify irreversible fouling potential of different water samples. Results show that under similar DOC level in feed water, colloids present much more irreversible fouling than other fractions. The fouling effect of the isolates is related to their size, chemical properties, and solution chemistry. Further investigations have identified that the interaction between colloids and other fractions also influences the performance of colloids in fouling phenomena.

  20. Removal characteristics and fluctuation of norovirus in a pilot-plant by an ultrafiltration membrane for the reclamation of treated sewage.

    PubMed

    Yasui, Nobuhito; Suwa, Mamoru; Sakurai, Kensuke; Suzuki, Yutaka; Tsumori, Jun; Kobayashi, Kentaro; Takabatake, Hiroo; Lee, Sun Tae; Yamashita, Naoyuki; Tanaka, Hiroaki

    2016-11-01

    When ultrafiltration (UF) membrane processes that are able to effectively reduce viruses are installed in a waste water reclamation system, the security of sanitation safety for water-borne diseases is essential. It is important to understand the behaviour of enteric viruses such as Adenovirus, Rotavirus and Norovirus (NV), the detection rate of which is relatively high in sewage. This study focused on the UF membrane process for the reclaimed water treatment process, and investigated the removal performance in NV type GI and GII in the UF membrane process by performing coagulation and sedimentation as the pre-treatment process in a pilot-plant by considering the concentration fluctuation of the influent. The removal ratio of GI and GII by the UF membrane process alone was 3.3 ± 0.7 Log in GI and 3.6 ± 1.0 Log in GII, and no clear difference in the removal ratio by NV species type was observed. The removal ratio of NV GII was increased by about 0.6 Log on average (4.2 ± 1.1 Log) compared with the UF membrane process only when the coagulation and sedimentation process were conducted as pre-treatment. However, there was no significant difference in the removal of NV GI by conducting the coagulation and sedimentation process.

  1. Amphiphilic thiol functional linker mediated sustainable anti-biofouling ultrafiltration nanocomposite comprising a silver nanoparticles and poly(vinylidene fluoride) membrane.

    PubMed

    Park, Sung Yong; Chung, Jae Woo; Chae, Young Kee; Kwak, Seung-Yeop

    2013-11-13

    We develop sustainable anti-biofouling ultrafiltration membrane nanocomposites by covalently immobilizing silver nanoparticles (AgNPs) onto poly(vinylidene fluoride) (PVDF) membrane mediated by a thiol-end functional amphiphilic block copolymer linker. Field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDXS) measurements reveal that the AgNPs are highly bound and dispersed to the PVDF membrane due to the strong affinity of the AgNPs with the thiol-modified block copolymeric linkers, which have been anchored to the PVDF membrane. The membrane performs well under water permeability and particle rejection measurements, despite the high deposition of AgNPs on the surface of membrane. The Ag-PVDF membrane nanocomposite significantly inhibits the growth of bacteria on the membrane surface, resulting in enhanced anti-biofouling property. Importantly, the AgNPs are not released from the membrane surface due to the robust covalent bond between the AgNPs and the thiolated PVDF membrane. The stability of the membrane nanocomposite ensures a sustainable anti-biofouling activity of the membrane. PMID:24144007

  2. Integrated in-line coagulation-aerated ultrafiltration for drinking-water production: A case study from laboratory to pilot plant.

    PubMed

    Rojas-Serrano, Fátima; Pérez, Jorge I; Gómez, Miguel A

    2015-01-01

    A pilot-scale study was made for drinking-water production from low-quality influents with in-line coagulation as pre-treatment of aerated ultrafiltration. Optimum flocculation parameters were previously determined in the laboratory, searching for large and strong flocs that could resist aeration without increasing the membrane fouling. Nevertheless, the comparison of the jar tests and the pilot-scale results showed that the former could help pre-dimensioning the flocculation facilities but could not precisely reproduce the behavior of the flocs in the membrane tank. The optimum coagulant dosage enabled the highest dissolved organic carbon (DOC) removal without affecting membrane fouling. Additionally, as opposed to the jar-test results, long retention times led to the lowest fouling rates while the velocity gradient affected neither the effluent quality nor the membrane fouling. These findings suggested that the influence of the flocculation parameters was masked by aeration inside the membrane tank but, even so, 43% and 82% DOC and UVA254 removals, respectively, were reached. Furthermore, the growth of the total membrane resistance with time was logarithmic instead of linear, confirming the suitability of the pre-treatment for low-quality influents. PMID:26259629

  3. Studies on a novel approach for the separation of L-phenylalanine amino acid from fermentation broth using a newly developed charged ultrafiltration membrane. I. Single solute system

    SciTech Connect

    Agarwal, A.K.; Huang, R.Y.M. )

    1994-01-01

    A newly developed thin-film composite (TFC) ultrafiltration membrane made of sulfonated poly(phenylene oxide) (SPPO) was used to establish the feasibility of separating L-phenylalanine from the fermentation broth containing a number of dissolved inorganic and organic solutes as an alternative approach to the currently used complex and uneconomical conventional ion-exchange schemes. It was found that the rejection of inorganic salts in a single component system was highly dependent on the feed solution concentration and varied inversely with it. The pH of the feed solution was found to have a strong effect on the rejection of L-phenylalanine, changing it from - 10 to 90%. This rejection behavior was identical for the two TFC-SPPO membrane samples which had molecular weight cutoff ratings of 10,000 and 20,000, respectively, although the permeate flux of the latter sample was almost twice that of the former sample. It was found that glucose molecules were not rejected by the membrane. 11 refs., 18 figs., 2 tab.

  4. Parameter Identification of an Ultrafiltration Model for Organics Removal in a Full-Scale Wastewater Reclamation Plant with Sparse and Incomplete Monitoring Data

    PubMed Central

    Sun, Fu; Zeng, Siyu; Huang, Yunqing; He, Miao

    2016-01-01

    Ultrafiltration (UF) has become one of the dominant treatment processes for wastewater reclamation in China. Modeling is an effective instrument to understand and optimize UF systems. To this end, a previously developed UF model for organics removal was applied to the UF process in a typical, full-scale wastewater reclamation plant (WRP) in China. However, the sparse and incomplete field monitoring data from the studied WRP made the traditional model analysis approaches hardly work in this case. Therefore, two strategies, namely Strategy 1 and Strategy 2, were proposed, following a regional sensitivity analysis approach, for model parameter identification. Strategy 1 aimed to identify the model parameters and the missing model input, i.e. sampling times, simultaneously, while Strategy 2 tried to separate these two processes to reduce the dimension of the identification problem through an iteration procedure. With these two strategies, the model performed well in the Qinghe WRP with the absolute relative errors between the simulated and observed total organic carbon (TOC) generally below 10%. The four model parameters were all sensitive and identifiable, and even the sampling times could be roughly identified. Given the incomplete model input, these results were encouraging and added to the trustworthiness of model when it was applied to the Qinghe WRP. PMID:27529845

  5. Isolation of α-Amylase Inhibitors from Kadsura longipedunculata Using a High-Speed Counter-Current Chromatography Target Guided by Centrifugal Ultrafiltration with LC-MS.

    PubMed

    Cen, Yin; Xiao, Aiping; Chen, Xiaoqing; Liu, Liangliang

    2016-01-01

    In this study, a high-speed counter-current chromatography (HSCCC) separation method target guided by centrifugal ultrafiltration with high-performance liquid chromatography-mass spectrometry (CU-LC-MS) was proposed. This method was used to analyze α-amylase inhibitors from Kadsura longipedunculata extract. According to previous screening with CU-LC-MS, two screened potential α-amylase inhibitors was successfully isolated from Kadsura longipedunculata extract using HSCCC under the optimized experimental conditions. The isolated two target compounds (with purities of 92.3% and 94.6%) were, respectively, identified as quercetin-3-O-rhamnoside (1) and protocatechuic acid (2) based on the MS, UV, and ¹H-NMR spectrometry data. To verify the inhibition of screened compounds, the inhibitory activities of quercetin-3-O-rhamnoside (1) and protocatechuic acid (2) on α-amylase were tested, and it demonstrated that the experimental IC50 values of quercetin-3-O-rhamnoside (1) and protocatechuic acid (2) were 28.8 and 12.5 μmol/L. These results proved that the hyphenated technique using CU-LC-MS and HSCCC was a rapid, competent, and reproductive method to screen and separate potential active compounds, like enzyme inhibitors from the extract of herbal medicines. PMID:27617987

  6. Contribution of effluent organic matter (EfOM) to ultrafiltration (UF) membrane fouling: isolation, characterization, and fouling effect of EfOM fractions.

    PubMed

    Zheng, Xing; Khan, Muhammad Tariq; Croué, Jean-Philippe

    2014-11-15

    EfOM has been regarded as a major organic foulant resulting in UF membrane fouling in wastewater reclamation. To investigate fouling potential of different EfOM fractions, the present study isolated EfOM into hydrophobic neutrals (HPO-N), colloids, hydrophobic acids (HPO-A), transphilic neutrals and acids (TPI), and hydrophilics (HPI), and tested their fouling effect in both salt solution and pure water during ultrafiltration (UF). Major functional groups and chemical structure of the isolates were identified using Fourier transform infrared spectroscopy (FT-IR) and solid-state carbon nuclear magnetic resonance ((13)C NMR) analysis. The influence of the isolation process on the properties of EfOM fractions was minor because the raw and reconstituted secondary effluents were found similar with respect to UV absorbance, molecular size distribution, and fluorescence character. In membrane filtration tests, unified membrane fouling index (UMFI) and hydraulic resistance were used to quantify irreversible fouling potential of different water samples. Results show that under similar DOC level in feed water, colloids present much more irreversible fouling than other fractions. The fouling effect of the isolates is related to their size, chemical properties, and solution chemistry. Further investigations have identified that the interaction between colloids and other fractions also influences the performance of colloids in fouling phenomena. PMID:25173435

  7. Removal characteristics and fluctuation of norovirus in a pilot-plant by an ultrafiltration membrane for the reclamation of treated sewage.

    PubMed

    Yasui, Nobuhito; Suwa, Mamoru; Sakurai, Kensuke; Suzuki, Yutaka; Tsumori, Jun; Kobayashi, Kentaro; Takabatake, Hiroo; Lee, Sun Tae; Yamashita, Naoyuki; Tanaka, Hiroaki

    2016-11-01

    When ultrafiltration (UF) membrane processes that are able to effectively reduce viruses are installed in a waste water reclamation system, the security of sanitation safety for water-borne diseases is essential. It is important to understand the behaviour of enteric viruses such as Adenovirus, Rotavirus and Norovirus (NV), the detection rate of which is relatively high in sewage. This study focused on the UF membrane process for the reclaimed water treatment process, and investigated the removal performance in NV type GI and GII in the UF membrane process by performing coagulation and sedimentation as the pre-treatment process in a pilot-plant by considering the concentration fluctuation of the influent. The removal ratio of GI and GII by the UF membrane process alone was 3.3 ± 0.7 Log in GI and 3.6 ± 1.0 Log in GII, and no clear difference in the removal ratio by NV species type was observed. The removal ratio of NV GII was increased by about 0.6 Log on average (4.2 ± 1.1 Log) compared with the UF membrane process only when the coagulation and sedimentation process were conducted as pre-treatment. However, there was no significant difference in the removal of NV GI by conducting the coagulation and sedimentation process. PMID:26979931

  8. Dual layer hollow fiber PVDF ultra-filtration membranes containing Ag nano-particle loaded zeolite with longer term anti-bacterial capacity in salt water.

    PubMed

    Shi, Huyan; Xue, Lixin; Gao, Ailin; Zhou, Qingbo

    2016-01-01

    Dual layer polyvinylidene fluoride (PVDF), antibacterial, hollow fiber, ultra-filtration composite membranes with antibacterial particles (silver (Ag) nano-particles loaded zeolite (Z-Ag)) in the outer layer were prepared with high water flux and desired pore sizes. The amounts of Ag(+) released from the composite membranes, freshly made and stored in water and salt solution, were measured. The result indicated that dual layer PVDF antibacterial hollow fiber containing Z-Ag (M-1-Ag) still possessed the ability of continuous release of Ag(+) even after exposure to water with high ionic content, showing a longer term resistance to bacterial adhesion and antibacterial activity than membrane doped with Z-Ag(+) (M-1). Results from an anti-adhesion and bacteria killing test with Escherichia coli supported that the antibacterial efficiency of dual hollow fiber PVDF membranes with Z-Ag was much higher than those with Z-Ag(+) after long time storage in water or exposure to phosphate buffered saline (PBS) solution. This novel hollow fiber membrane may find applications in constructing sea water pretreatment devices with long term antifouling capability for the desalination processes. PMID:27148717

  9. Mechanism of pretreatment using magnetic poly(glycidyl methacrylate) resin in an ultrafiltration membrane system used in algae-rich water treatment.

    PubMed

    Liu, Yu; Chen, Wei; Dong, Changlong; Liu, Cheng; Liu, Hai Cheng

    2015-01-01

    Ultrafiltration (UF) membrane fouling brought by algae-rich water controlling has been the research focus in recent years. The pretreatment of magnetic poly(glycidyl methacrylate) (m-PGMA) for sedimental tank effluent was investigated as well as its performance in combined UF processes. The optimal dose of m-PGMA was found to be 5 mL/L, which can bring a significant improvement to the removal efficiency of natural organic matter. With regards to membrane fouling, the use of m-PGMA also resulted in lowered irreversible and reversible membrane resistances in comparison with results obtained when operating without m-PGMA. In addition, four classic filtration models were introduced to analyse the fouling mechanisms. The proportion of standard blocking of pores has been weakened in the mechanism of membrane fouling when the pretreatment of m-PGMA exists. A very loose cake layer and relieved pore blockage were observed by scanning electron microscopy during m-PGMA/UF process.

  10. Pilot-scale study on the treatment of basal aquifer water using ultrafiltration, reverse osmosis and evaporation/crystallization to achieve zero-liquid discharge.

    PubMed

    Loganathan, Kavithaa; Chelme-Ayala, Pamela; Gamal El-Din, Mohamed

    2016-01-01

    Basal aquifer water is deep groundwater found at the bottom of geological formations, underlying bitumen-saturated sands. Some of the concerns associated with basal aquifer water at the Athabasca oil sands are the high concentrations of hardness-causing compounds, alkalinity, and total dissolved solids. The objective of this pilot-scale study was to treat basal aquifer water to a quality suitable for its reuse in the production of synthetic oil. To achieve zero-liquid discharge (ZLD) conditions, the treatment train included chemical oxidation, polymeric ultrafiltration (UF), reverse osmosis (RO), and evaporation-crystallization technologies. The results indicated that the UF unit was effective in removing solids, with UF filtrate turbidity averaging 2.0 NTU and silt density index averaging 0.9. Membrane autopsies indicated that iron was the primary foulant on the UF and RO membranes. Laboratory and pilot-scale tests on RO reject were conducted to determine the feasibility of ZLD crystallization. Due to the high amounts of calcium, magnesium, and bicarbonate in the RO reject, softening of the feed was required to avoid scaling in the evaporator. Crystals produced throughout the testing were mainly sodium chloride. The results of this study indicated that the ZLD approach was effective in both producing freshwater and minimizing brine discharges. PMID:26433363

  11. Micellar Enhanced Spectrofluorimetric Method for the Determination of Ponatinib in Human Plasma and Urine via Cremophor RH 40 as Sensing Agent

    PubMed Central

    Darwish, Hany W.; Bakheit, Ahmed H.; Abdelhameed, Ali Saber; AlKhairallah, Amer S.

    2015-01-01

    An impressively simple and precise spectrofluorimetric procedure was established and validated for ponatinib (PTB) quantitation in biological fluids such as human plasma and human urine. This method depends on examining the fluorescence characteristics of PTB in a micellar system of Cremophor RH 40 (Cr RH 40). Cr RH 40 enhanced the intrinsic fluorescence of PTB distinctly in aqueous water. The fluorescence spectra of PTB was recorded at 457 nm following its excitation at 305 nm. Maximum fluorescence intensity was attained by addition of 0.7 mL of Cr RH 40 and one mL of phosphate buffer to PTB aliquots and then dilution with distilled water. There is a linear relationship between the fluorescence intensity of PTB and its concentration over the range 5–120 ngmL−1, with limit of detection and limit of quantification equal to 0.905 ngmL−1 and 2.742 ngmL−1, respectively. The accuracy and the precisions of the proposed method were checked and gave adequate results. The adopted method was applied with a great success for PTB quantitation in different biological matrices (spiked human plasma and urine) giving high recovery values. PMID:26880920

  12. Effects of different pretreatments on the performance of ceramic ultrafiltration membrane during the treatment of oil sands tailings pond recycle water: a pilot-scale study.

    PubMed

    Loganathan, Kavithaa; Chelme-Ayala, Pamela; El-Din, Mohamed Gamal

    2015-03-15

    Membrane filtration is an effective treatment method for oil sands tailings pond recycle water (RCW); however, membrane fouling and rapid decrease in permeate flux caused by colloids, organic matter, and bitumen residues present in the RCW hinder its successful application. This pilot-scale study investigated the impact of different pretreatment steps on the performance of a ceramic ultrafiltration (CUF) membrane used for the treatment of RCW. Two treatment trains were examined: treatment train 1 consisted of coagulant followed by a CUF system, while treatment train 2 included softening (Multiflo™ system) and coagulant addition, followed by a CUF system. The results indicated that minimum pretreatment (train 1) was required for almost complete solids removal. The addition of a softening step (train 2) provided an additional barrier to membrane fouling by reducing hardness-causing ions to negligible levels. More than 99% removal of turbidity and less than 20% removal of total organic carbon were achieved regardless of the treatment train used. Permeate fluxes normalized at 20 °C of 127-130 L/m(2) h and 111-118 L/m(2) h, with permeate recoveries of 90-93% and 90-94% were observed for the treatment trains 1 and 2, respectively. It was also found that materials deposited onto the membrane surface had an impact on trans-membrane pressure and influenced the required frequencies of chemically enhanced backwashes (CEBs) and clean-in-place (CIP) procedures. The CIP performed was successful in removing fouling and scaling materials such that the CUF performance was restored to baseline levels. The results also demonstrated that due to their low turbidity and silt density index values, permeates produced in this pilot study were suitable for further treatment by high pressure membrane processes.

  13. Probing the roles of Ca(2+) and Mg(2+) in humic acids-induced ultrafiltration membrane fouling using an integrated approach.

    PubMed

    Wang, Long-Fei; He, Dong-Qin; Chen, Wei; Yu, Han-Qing

    2015-09-15

    Membrane fouling induced by natural organic matter (NOM) negatively affects the performance of ultrafiltration (UF) technology in producing drinking water. Divalent cation is found to be an important factor that affects the NOM-induced membrane fouling process. In this work, attenuated total reflection-Fourier transformation infrared spectroscopy (ATR-FTIR) coupled with quartz crystal microbalance (QCM), assisted by isothermal titration calorimetry (ITC), is used to explore the contribution of Mg(2+) and Ca(2+), the two abundant divalent cations in natural water, to the UF membrane fouling caused by humic acid (HA) at a molecular level. The results show that Ca(2+) exhibited superior performance in accelerating fouling compared to Mg(2+). The hydrophobic polyethersulfone (PES) membrane exhibited greater complexation with HA in the presence of Mg(2+) and Ca(2+), compared to the hydrophilic cellulose membrane, as evidenced by the more intense polysaccharide C-O, aromatic C=C and carboxylic C=O bands in the FTIR spectra. The QCM and ITC measurements provide quantitative evidence to support that Ca(2+) was more effective than Mg(2+) in binding with HA and accumulating foulants on the membrane surfaces. The higher charge neutralization capacity and more favorable binding ability of Ca(2+) were found to be responsible for its greater contribution to the NOM-induced membrane fouling than Mg(2+). This work offers a new insight into the mechanism of cation-mediated NOM-induced membrane fouling process, and demonstrates that such an integrated ATR-FTIR/QCM/ITC approach could be a useful tool to explore other complicated interaction processes in natural and engineered environments. PMID:26094086

  14. Influence of N-phthaloyl chitosan on poly (ether imide) ultrafiltration membranes and its application in biomolecules and toxic heavy metal ion separation and their antifouling properties

    NASA Astrophysics Data System (ADS)

    Kanagaraj, P.; Nagendran, A.; Rana, D.; Matsuura, T.; Neelakandan, S.; Karthikkumar, T.; Muthumeenal, A.

    2015-02-01

    N-phthaloyl chitosan (NPHCs), which could be dissolved in various organic solvents, is synthesized for the modification of poly (ether imide) (PEI) ultrafiltration membrane. Blend membrane with 2 wt% NPHCs exhibited higher pure water flux (112.2 l m-2 h-1), higher water content (63.4%) and lower hydraulic resistance (3 kPa/l m-2 h-1). The top surface morphology of the control PEI membrane changed from a dense surface to visible pores with the increase in NPHCs concentration. The surface roughness of PEI membranes increased with an increase in NPHCs concentration in the casting solution. Application studies were carried out to find the rejection and permeate flux of proteins such as bovine serum albumin (BSA), egg albumin (EA), pepsin and trypsin and toxic heavy metal ions such as Cr(III), Zn(II), Cd(II) and Pb(II). The result shows that the flux and separation performances are dependent upon the content of NPHCs. Furthermore, the blend membranes were subjected to the determination of pore statistics and MWCO. It was found that the blending of NPHCs into the PEI membrane had a visible effect upon MWCO and pore size. The significant effect of hydrophilicity of NPHCs on the fouling of PEI/NPHCs blend membranes by BSA was also discussed. It was found that the blend membranes with 2 wt% NPHCs content had a higher FRR (88.6%), higher reversible fouling (23.7%) and lower irreversible fouling (11.4%) which explained their improved antifouling properties. Thus, the modified chitosan proved to play an important role in the improvement of UF membrane performance.

  15. Manipulating Migration Behavior of Magnetic Graphene Oxide via Magnetic Field Induced Casting and Phase Separation toward High-Performance Hybrid Ultrafiltration Membranes.

    PubMed

    Xu, Zhiwei; Wu, Tengfei; Shi, Jie; Wang, Wei; Teng, Kunyue; Qian, Xiaoming; Shan, Mingjing; Deng, Hui; Tian, Xu; Li, Cuiyu; Li, Fengyan

    2016-07-20

    Hybrid membranes blended with nanomaterials such as graphene oxide (GO) have great opportunities in water applications due to their multiple functionalities, but they suffer from low modification efficiency of nanomaterials due to the fact that plenty of the nanomaterials are embedded within the polymer matrix during the blending process. Herein, a novel Fe3O4/GO-poly(vinylidene fluoride) (Fe3O4/GO-PVDF) hybrid ultrafiltration membrane was developed via the combination of magnetic field induced casting and a phase inversion technique, during which the Fe3O4/GO nanocomposites could migrate toward the membrane top surface due to magnetic attraction and thereby render the surface highly hydrophilic with robust resistance to fouling. The blended Fe3O4/GO nanocomposites migrated to the membrane surface with the magnetic field induced casting, as verified by X-ray photoelectron spectroscopy, elemental analysis, and energy dispersive X-ray spectroscopy. As a result, the novel membranes exhibited significantly improved hydrophilicity (with a contact angle of 55.0°) and water flux (up to 595.39 L m(-2) h(-1)), which were improved by 26% and 206%, 12% and 49%, 25% and 154%, and 11% and 33% compared with those of pristine PVDF membranes and PVDF hybrid membranes blended with GO, Fe3O4, and Fe3O4/GO without the assistance of magnetic field during membrane casting, respectively. Besides, the novel membranes showed high rejection of bovine serum albumin (>92%) and high flux recovery ratio (up to 86.4%). Therefore, this study presents a novel strategy for developing high-performance hybrid membranes via manipulating the migration of nanomaterials to the membrane surface rather than embedding them in the membrane matrix. PMID:27355273

  16. [Enhanced radiosensitivity of H22 ascitic tumor to 12C6+ ions radiation in ultra-filtration extract mixture from Astragalus mongholicus-treated mice].

    PubMed

    Wang, Bin-bin; Wang, Xiao-hu; Liu, Kai; Sun, Shao-bo; Song, Peng; Li, Ying-dong

    2015-12-01

    This study was designed to investigate the impact of ultra-filtration extract mixture from Astragals mongholicus (UEMAM) o radiosensitivity of H22 ascitic tumor in mice to 12C6+ ions radiation. The H22 ascitic tumor model was established in mice by intraperitoneal injection of 0.2 mL H22 ascitic cells. The animals were subsequently divided into 4 groups randomly, treated with normal saline, UEMAM, heavy ion beam radiotherapy and UEMAM plus heavy ion beam radiotherapy, respectively. The body weights, abdomen circumference of the mice were measured and the mouse behavior was monitored every day; survival time was recorded to evaluate life extension effect; flow cytometry technique was used to detect H22 cell apoptosis and cell cycle; protein levels of p53, Bax, Bcl-2 and cleaved Caspase-3 were analyzed by Western blot; the single cell gel electrophoresis was used to detect the level of deoxyribonucleic acid damage (DNA damage). The results suggest that UEMAM significantly increased survival time, and decreased body weights and abdomen circumference over the saline control group. The treatment increased cell apoptosis, cycle arrest and DNA damage compared to the saline control group. UEMAM significantly enhanced the therapeutic effect of heavy ion beam radiation in survival time, and decreased body weights and abdomen circumference in the tumor-baring mice. The combination increased cell apoptosis, cycle arrest and DNA damage compared to the radiotherapy group. The results of Western blot suggest that the treatment significantly enhanced p53-induced apoptotic signals. The experiment discovered that UEMAM could improve radiosensitivity of H22 ascitic tumor through activation of p53-mediated apoptotic signal pathway. PMID:27169282

  17. Combined coagulation-disk filtration process as a pretreatment of ultrafiltration and reverse osmosis membrane for wastewater reclamation: an autopsy study of a pilot plant.

    PubMed

    Chon, Kangmin; Kim, Seung Joon; Moon, Jihee; Cho, Jaeweon

    2012-04-15

    The effects of the combined coagulation-disk filtration (CC-DF) process on the fouling characteristics and behavior caused by interactions between effluent organic matter (EfOM) and the membrane surfaces of the ultrafiltration (UF) and reverse osmosis (RO) membranes in a pilot plant for municipal wastewater reclamation (MWR) were investigated. The feed water from secondary effluents was treated by the CC-DF process used as a pretreatment for the UF membrane to mitigate fouling formation and the permeate from the CC-DF process was further filtered by two UF membrane units in parallel arrangement and fed into four RO modules in a series connection. The CC-DF process was not sufficient to mitigate biofouling but the UF membrane was effective in mitigating biofouling on the RO membrane surfaces. Fouling of the UF and RO membranes was dominated by hydrophilic fractions of EfOM (e.g., polysaccharide-like and protein-like substances) and inorganic scaling (e.g., aluminum, calcium and silica). The desorbed UF membrane foulants included more aluminum species and hydrophobic fractions than the desorbed RO membrane foulants, which was presumably due to the residual coagulants and aluminum-humic substance complexes. The significant change in the surface chemistry of the RO membrane (a decrease in surface charge and an increase in contact angle of the fouled RO membranes) induced by the accumulation of hydrophilic EfOM onto the negatively charged RO membrane surface intensified the fouling formation of the fouled RO membrane by hydrophobic interaction between the humic substances of EfOM with relatively high hydrophobicity and the fouled RO membranes with decreased surface charge and increased contract angle.

  18. Sporocidal properties of peracetic acid and hydrogen peroxide, alone and in combination, in comparison with chlorine and formaldehyde for ultrafiltration membrane disinfection.

    PubMed

    Alasri, A; Valverde, M; Roques, C; Michel, G; Cabassud, C; Aptel, P

    1993-01-01

    The sporocidal properties of peracetic acid, hydrogen peroxide, chlorine, and formaldehyde were compared in vitro using a dilution-neutralization micromethod. A combination of peracetic acid and hydrogen peroxide was also tested to assess their interactions. The activities of these agents, which are widely used as disinfectants, were evaluated against Bacillus spore isolates found on stored membranes and collection cultures. Peracetic acid and chlorine exhibited an excellent antimicrobial activity, with a destruction of 10(5) spores/mL after 5 min of contact. Generally the effects of the biocides tested were time dependent. The sporocidal activities of hydrogen peroxide and formaldehyde were the lowest. The combination of peracetic acid and hydrogen peroxide, tested by a checkerboard micromethod, was found to be synergistic. The minimal sporocidal concentration (MSC) was established in terms of time for each biocide. The lowest MSC values for peracetic acid, hydrogen peroxide, chlorine, and formaldehyde were 168-336 ppm (1-2 h of contact), 5625-11250 ppm (5-7 h), 168-336 ppm (2-3 h), and 1875-3750 ppm (5-30 min), respectively. The MSC of a biocide combination of peracetic acid and hydrogen peroxide showed that synergy was maintained with increasing contact time and that the MSC could be reduced by two to eight times when compared with those of the biocides alone. Optimal concentrations and contact times of those chemicals that were promising in vitro were then tested for their ability to disinfect ultrafiltration membranes. The sporocidal activities of peroxide compounds and chlorine were confirmed and the synergism between peracetic acid and hydrogen peroxide was also maintained.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8439874

  19. Effect of annatto addition and bleaching treatments on ultrafiltration flux during production of 80% whey protein concentrate and 80% serum protein concentrate.

    PubMed

    Adams, Michael C; Zulewska, Justyna; Barbano, David M

    2013-04-01

    The goals of this study were to determine if adding annatto color to milk or applying a bleaching process to whey or microfiltration (MF) permeate influenced ultrafiltration (UF) flux, diafiltration (DF) flux, or membrane fouling during production of 80% whey protein concentrate (WPC80) or 80% serum protein concentrate (SPC80). Separated Cheddar cheese whey (18 vats using 900 kg of whole milk each) and MF permeate of skim milk (18 processing runs using 800 kg of skim milk each) were produced to make WPC80 and SPC80, respectively. The 6 treatments, replicated 3 times each, that constituted the 18 processing runs within either whey or MF permeate UF were as follows: (1) no annatto; (2) no annatto+benzoyl peroxide (BPO); (3) no annatto+hydrogen peroxide (H2O2); (4) annatto; (5) annatto+BPO; and (6) annatto+H2O2. Approximately 700 kg of whey or 530 kg of MF permeate from each treatment were heated to 50°C and processed in 2 stages (UF and DF) with the UF system in batch recirculation mode using a polyethersulfone spiral-wound UF membrane with a molecular weight cutoff of 10,000 Da. Addition of annatto color had no effect on UF or DF flux. The processes of bleaching whey or MF permeate with or without added color improved flux during processing. Bleaching with H2O2 usually produced higher flux than bleaching with BPO. Bleaching with BPO increased WPC80 flux to a greater extent than it did SPC80 flux. Though no differences in mean flux were observed for a common bleaching treatment between the WPC80 and SPC80 production processes during the UF stage, mean flux during WPC80 DF was higher than mean flux during SPC80 DF for each bleaching treatment. Water flux values before and after processing were used to calculate a fouling coefficient that demonstrated differences in fouling which were consistent with flux differences among treatments. In both processes, bleaching with H2O2 led to the largest reduction in fouling. No effect of annatto on fouling was observed. The

  20. Coagulation and oxidation for controlling ultrafiltration membrane fouling in drinking water treatment: Application of ozone at low dose in submerged membrane tank.

    PubMed

    Yu, Wenzheng; Graham, Nigel J D; Fowler, Geoffrey D

    2016-05-15

    Coagulation prior to ultrafiltration (UF) is widely applied for treating contaminated surface water sources for potable supply. While beneficial, coagulation alone is unable to control membrane fouling effectively in many cases, and there is continuing interest in the use of additional, complementary methods such as oxidation in the pre-treatment of raw water prior to UF. In this study, the application of ozone at low dose in the membrane tank immediately following coagulation has been evaluated at laboratory-scale employing model raw water. In parallel tests with and without the application of ozone, the impact of applied ozone doses of 0.5 mg L(-1) and 1.5 mg L(-1) (approximately 0.18 mg L(-1) and 0.54 mg L(-1) consumed ozone, respectively) on the increase of trans-membrane pressure (TMP) was evaluated and correlated with the quantity and nature of membrane deposits, both as a cake layer and within membrane pores. The results showed that a dose of 0.5 mgO3 L(-1) gave a membrane fouling rate that was substantially lower than without ozone addition, while a dose of 1.5 mgO3 L(-1) was able to prevent fouling effects significantly (no increase in TMP). Ozone was found to decrease the concentration of bacteria (especially the concentration of bacteria per suspended solid) in the membrane tank, and to alter the nature of dissolved organic matter by increasing the proportion of hydrophilic substances. Ozone decreased the concentration of extracellular polymeric substances (EPS), such as polysaccharides and proteins, in the membrane cake layer; the reduced EPS and bacterial concentrations resulted in a much thinner cake layer, although the suspended solids concentration was much higher in the ozone added membrane tank. Ozone also decreased the accumulation and hydrophobicity of organic matter within the membrane pores, leading to minimal irreversible fouling. Therefore, the application of low-dose ozone within the UF membrane tank is a potentially important

  1. Development of a method to screen and isolate potential xanthine oxidase inhibitors from Panax japlcus var via ultrafiltration liquid chromatography combined with counter-current chromatography.

    PubMed

    Li, Sainan; Tang, Ying; Liu, Chunming; Li, Jing; Guo, Liping; Zhang, Yuchi

    2015-03-01

    Panax japlcus var is a typical Chinese herb with a large number of saponins existing in all parts of it. The common methods of screening and isolating saponins are mostly labor-intensive and time-consuming. In this study, a new assay based on ultrafiltration-liquid chromatography-mass spectrometry (UF-LC-MS) was developed for the rapid screening and identifying of the ligands for xanthine oxidase from the extract of P. japlcus. Six saponins were identified as xanthine oxidase inhibitors from the extract. Subsequently, the specific binding ligands, namely, 24 (R)-majoroside R1, chikusetsusaponin IVa, oleanolic acid-28-O-β-D-glucopyranoside, notoginsenoside Fe, ginsenoside Rb2 and ginsenoside Rd (the purities of them were 95.74%, 96.12%, 93.19%, 94.83%, 95.07% and 94.62%, respectively) were separated by high-speed counter-current chromatography (HSCCC). The component ratio of the solvent system of HSCCC was calculated with the help of a multiexponential function model was optimized. The partition coefficient (K) values of the target compounds and resolutions of peaks were employed as the research indicators, and exponential function and binomial formulas were used to optimize the solvent system and flow rate of the mobile phases in a two-stage separation. An optimized two-phase solvent system composed of ethyl acetate, isopropanol, 0.1% aqueous formic acid (1.9:1.0:1.3, v/v/v, for the first-stage) and that composed of methylene chloride, acetonitrile, isopropanol, 0.1% aqueous formic acid (5.6:1.0:2.4:5.2, v/v/v/v, for the second-stage) were used to isolate the six compounds from P. japlcus. The targeted compounds isolated, collected and purified by HSCCC were analyzed by high performance liquid chromatography (UPLC), and the chemical structures of all the six compounds were identified by UV, MS and NMR. The results demonstrate that UF-LC-MS combined with HSCCC might provide not only a powerful tool for screening and isolating xanthine oxidase inhibitors in complex

  2. Coagulation and oxidation for controlling ultrafiltration membrane fouling in drinking water treatment: Application of ozone at low dose in submerged membrane tank.

    PubMed

    Yu, Wenzheng; Graham, Nigel J D; Fowler, Geoffrey D

    2016-05-15

    Coagulation prior to ultrafiltration (UF) is widely applied for treating contaminated surface water sources for potable supply. While beneficial, coagulation alone is unable to control membrane fouling effectively in many cases, and there is continuing interest in the use of additional, complementary methods such as oxidation in the pre-treatment of raw water prior to UF. In this study, the application of ozone at low dose in the membrane tank immediately following coagulation has been evaluated at laboratory-scale employing model raw water. In parallel tests with and without the application of ozone, the impact of applied ozone doses of 0.5 mg L(-1) and 1.5 mg L(-1) (approximately 0.18 mg L(-1) and 0.54 mg L(-1) consumed ozone, respectively) on the increase of trans-membrane pressure (TMP) was evaluated and correlated with the quantity and nature of membrane deposits, both as a cake layer and within membrane pores. The results showed that a dose of 0.5 mgO3 L(-1) gave a membrane fouling rate that was substantially lower than without ozone addition, while a dose of 1.5 mgO3 L(-1) was able to prevent fouling effects significantly (no increase in TMP). Ozone was found to decrease the concentration of bacteria (especially the concentration of bacteria per suspended solid) in the membrane tank, and to alter the nature of dissolved organic matter by increasing the proportion of hydrophilic substances. Ozone decreased the concentration of extracellular polymeric substances (EPS), such as polysaccharides and proteins, in the membrane cake layer; the reduced EPS and bacterial concentrations resulted in a much thinner cake layer, although the suspended solids concentration was much higher in the ozone added membrane tank. Ozone also decreased the accumulation and hydrophobicity of organic matter within the membrane pores, leading to minimal irreversible fouling. Therefore, the application of low-dose ozone within the UF membrane tank is a potentially important

  3. Low-sodium Cheddar cheese: Effect of fortification of cheese milk with ultrafiltration retentate and high-hydrostatic pressure treatment of cheese.

    PubMed

    Ozturk, M; Govindasamy-Lucey, S; Jaeggi, J J; Johnson, M E; Lucey, J A

    2015-10-01

    Low-sodium cheeses often exhibit an acidic flavor due to excessive acid production during the manufacturing and the initial stage of ripening, which is caused by ongoing starter culture activity facilitated by the low salt-in-moisture levels. We proposed that this excessive starter-induced acidity could be prevented by the fortification of cheese milk with ultrafiltration (UF) retentates (to increase curd buffering), and by decreasing microbial activity using the application of high-hydrostatic pressure (HHP) treatment (that is, to reduce residual starter numbers). Camel chymosin was also used as a coagulant to help reduce bitterness development (a common defect in low-sodium cheeses). Three types of low-Na (0.8% NaCl) Cheddar cheeses were manufactured: non-UF fortified, no HHP applied (L-Na); UF-fortified (cheese milk total solids = 17.2 ± 0.6%), no HHP applied (L-Na-UF); and UF-fortified, HHP-treated (L-Na-UF-HHP; 500 MPa for 3 min applied at 1 d post-cheese manufacture). Regular salt (2% NaCl) non-UF fortified, non-HHP treated (R-Na) cheese was also manufactured for comparison purposes. Analysis was performed at 4 d, 2 wk, and 1, 3, and 6 mo after cheese manufacture. Cheese functionality during ripening was assessed using texture profile analysis and dynamic low-amplitude oscillatory rheology. Sensory Spectrum and quantitative descriptive analysis was conducted with 9 trained panelists to evaluate texture and flavor attributes using a 15-point scale. At 4 d and 2 wk of ripening, L-Na-UF-HHP cheese had ~2 and ~4.5 log lower starter culture numbers, respectively, than all other cheeses. Retentate fortification of cheese milk and HHP treatment resulted in low-Na cheeses having similar insoluble calcium concentrations and pH values compared with R-Na cheese during ripening. The L-Na-UF cheese exhibited significantly higher hardness values (measured by texture profile analysis) compared with L-Na cheese until 1 mo of ripening; however, after 1 mo, all low-Na cheeses

  4. Low-sodium Cheddar cheese: Effect of fortification of cheese milk with ultrafiltration retentate and high-hydrostatic pressure treatment of cheese.

    PubMed

    Ozturk, M; Govindasamy-Lucey, S; Jaeggi, J J; Johnson, M E; Lucey, J A

    2015-10-01

    Low-sodium cheeses often exhibit an acidic flavor due to excessive acid production during the manufacturing and the initial stage of ripening, which is caused by ongoing starter culture activity facilitated by the low salt-in-moisture levels. We proposed that this excessive starter-induced acidity could be prevented by the fortification of cheese milk with ultrafiltration (UF) retentates (to increase curd buffering), and by decreasing microbial activity using the application of high-hydrostatic pressure (HHP) treatment (that is, to reduce residual starter numbers). Camel chymosin was also used as a coagulant to help reduce bitterness development (a common defect in low-sodium cheeses). Three types of low-Na (0.8% NaCl) Cheddar cheeses were manufactured: non-UF fortified, no HHP applied (L-Na); UF-fortified (cheese milk total solids = 17.2 ± 0.6%), no HHP applied (L-Na-UF); and UF-fortified, HHP-treated (L-Na-UF-HHP; 500 MPa for 3 min applied at 1 d post-cheese manufacture). Regular salt (2% NaCl) non-UF fortified, non-HHP treated (R-Na) cheese was also manufactured for comparison purposes. Analysis was performed at 4 d, 2 wk, and 1, 3, and 6 mo after cheese manufacture. Cheese functionality during ripening was assessed using texture profile analysis and dynamic low-amplitude oscillatory rheology. Sensory Spectrum and quantitative descriptive analysis was conducted with 9 trained panelists to evaluate texture and flavor attributes using a 15-point scale. At 4 d and 2 wk of ripening, L-Na-UF-HHP cheese had ~2 and ~4.5 log lower starter culture numbers, respectively, than all other cheeses. Retentate fortification of cheese milk and HHP treatment resulted in low-Na cheeses having similar insoluble calcium concentrations and pH values compared with R-Na cheese during ripening. The L-Na-UF cheese exhibited significantly higher hardness values (measured by texture profile analysis) compared with L-Na cheese until 1 mo of ripening; however, after 1 mo, all low-Na cheeses

  5. N-substituted monodentate alcohols as ligands modifying structure, properties and thermal stability of Mo(IV) complexes

    NASA Astrophysics Data System (ADS)

    Jurowska, Anna; Szklarzewicz, Janusz; Hodorowicz, Maciej; Tomecka, Monika; Lipkowski, Janusz; Nitek, Wojciech

    2015-02-01

    The reaction of N-substituted alcohols (2-aminoethanol, 3-amino-1-propanol and 2-hydroxyethylhydrazine) with K3Na[Mo(CN)4O2]ṡ6H2O in water-ethanol solution results in isolation of three new complexes of formulae: (PPh4)2[Mo(CN)4O(amet)]ṡ3H2O (1), (amet = 2-aminoethanol), (PPh4)2[Mo(CN)4O(ampro)]ṡ3H2O (2) (ampro = 3-amino-1-propanol) and (PPh4)2[Mo(CN)4O(ethyd)]ṡ3H2O (3) (ethyd = 2-hydroxyethylhydrazine). The isolated salts were characterized by elemental analysis, single crystal X-ray structure measurements, IR and UV-Vis spectroscopy and cyclic voltammetry. The complexes crystalize in triclinic space group with distorted octahedral geometry of the anion. The obtained salts belongs to a very rare group of complexes with monodentate terminal N-donating alcohols. The thermal stability is described for all complexes and compared with crystal structure parameters.

  6. An Improvement Delivery of siRNA by IRQ Ligand-Modified Double Membranous Nano-Carrier

    NASA Astrophysics Data System (ADS)

    Mudhakir, Diky; Tan, Erdal; Akita, Hidetaka; Harashima, Hideyoshi

    2010-10-01

    In the present study, the enhancement of siRNA delivery into cytosol from the IRQ-modified multi-envelope type nano-device (IRQ-MEND) was investigated. It is known that IRQ-MEND efficiently enters cells by clathrin-mediated endocytosis and caveolar endocytosis pathways, resulting in gene silencing. In the present study, we controlled the number of layers of IRQ-MEND encapsulating siRNA by using double membranous nano-device strategy. This vector design overcomes intracellular barriers such as endosomal membrane, resulting drastically enhance transgene expression. In addition, the contribution of uptake mechanism of IRQ-modified nano-carrier to transgene expression was studied. The use of hypertonic treatment inhibited gene silencing, but it was not suppressed by the addition of filipin. These results indicate that low pH is important to induce the transgene expression. In conclusion, delivery of cytosolic siRNA can be enhanced by the use of double-membranous nano-carrier system which utilizes a clathrin-mediated endocytosis pathway to induce gene silencing.

  7. Automated dead-end ultrafiltration for concentration and recovery of total coliform bacteria and laboratory-spiked Escherichia coli O157:H7 from 50-liter produce washes to enhance detection by an electrochemiluminescence immunoassay.

    PubMed

    Magaña, Sonia; Schlemmer, Sarah M; Leskinen, Stephaney D; Kearns, Elizabeth A; Lim, Daniel V

    2013-07-01

    An automated concentration system (ACS) based on dead-end ultrafiltration was used in this study to concentrate bacteria, including Escherichia coli O157:H7, from 50-liter produce washes (PWs, sieved produce wash). Cells trapped in the filters were recovered in approximately 400 ml of buffer to create PW retentates (PWRs). Extent of concentration was determined by analyzing PWs and PWRs for total coliform bacteria and E. coli O157:H7 using standard methods. In addition, an electrochemiluminescence immunoassay was evaluated for detection of E. coli O157:H7 in spiked PWs and PWRs to demonstrate usefulness of the ACS for same-day detection. The levels of total coliform bacteria and E. coli O157:H7 in PWRs were higher than those in PWs by 1.85 ± 0.41 log most probable number per 100 ml and 1.82 ± 0.24 log CFU/ml, respectively. Electrochemiluminescence detection of E. coli O157:H7 was accomplished within 2 h using ACS concentration of lettuce and spinach wash water artificially spiked with the pathogen at levels as low as 0.36 log CFU/ml and 1.39 log CFU/ml, respectively. Detection of E. coli O157:H7 at -0.93 ± 0.15 log CFU/ml in lettuce wash occurred within approximately 6 h when a 4-h enrichment step was added to the procedure. Use of dead-end ultrafiltration increased bacterial concentrations in PWR and allowed same-day detection of low levels of E. coli O157:H7 in PW. This concentration system could be useful to improve the sensitivity of current rapid methods for detection of low levels of foodborne pathogens in PW water.

  8. Effect of the variation of the level of lactose conversion in an immobilized lactase reactor upon operating costs for the production of Baker's yeast from hydrolyzed permeate obtained from the ultrafiltration of cottage cheese whey

    SciTech Connect

    Scott, T.C.; Hill, C.G. Jr.; Amundson, C.H.

    1987-01-01

    Operating costs for the production of Baker's yeast from hydrolyzed permeate from the ultrafiltration of cottage cheese whey were calculated as a function of the level of lactose conversion in the immobilized lactase reactor. These costs were calculated for the case of 90% conversion of lactose in the reactor and compared to those which result when running the reactor at lower conversions with recycle of unreacted lactose. Total operating costs were estimated by combining individual operating costs for the immobilized enzyme reactor, costs associated with processing a lactose recycle stream, and energy costs associated with cooling the reactor feed stream and sterilizing the hydrolysate stream. It was determined that operating costs are minimized at about 9.9 cents per pound of lactose when the reactor is run at approximately 72% conversion. This represents a savings of 2.4 cents per pound of lactose over the case of a once-through 90% conversion of lactose in the reactor. 8 refs., 4 figs., 9 tabs.

  9. A pilot-scale hybrid municipal wastewater reclamation system using combined coagulation and disk filtration, ultrafiltration, and reverse osmosis: removal of nutrients and micropollutants, and characterization of membrane foulants.

    PubMed

    Chon, Kangmin; Cho, Jaeweon; Shon, Ho Kyong

    2013-08-01

    A pilot-scale municipal wastewater reclamation system using combined coagulation and disk filtration (CC-DF), ultrafiltration (UF), and reverse osmosis (RO) membrane has been built to investigate removal of water contaminants and fouling mitigation. The reclaimed water using the pilot system could meet draft regulations on wastewater reuse of the California Department of Public Health (DOC: 0.5 mgC/L; TN: 5 mgN/L). The removal of micropolluants by the CC-DF process and UF could not be evaluated by their MW, Log D, and charge characteristics. However, they were identified as governing factors affecting the removal of micropollutants by the RO. The CC-DF process might effectively remove particulate materials capable of contributing to cake layer formation on the UF membrane surfaces but the residual coagulants provided a strong effect on fouling formation of the UF membrane. Thus, hydrophobic fractions of the desorbed UF membrane foulants were higher than those of the desorbed RO membrane foulants. PMID:23611699

  10. A pilot-scale hybrid municipal wastewater reclamation system using combined coagulation and disk filtration, ultrafiltration, and reverse osmosis: removal of nutrients and micropollutants, and characterization of membrane foulants.

    PubMed

    Chon, Kangmin; Cho, Jaeweon; Shon, Ho Kyong

    2013-08-01

    A pilot-scale municipal wastewater reclamation system using combined coagulation and disk filtration (CC-DF), ultrafiltration (UF), and reverse osmosis (RO) membrane has been built to investigate removal of water contaminants and fouling mitigation. The reclaimed water using the pilot system could meet draft regulations on wastewater reuse of the California Department of Public Health (DOC: 0.5 mgC/L; TN: 5 mgN/L). The removal of micropolluants by the CC-DF process and UF could not be evaluated by their MW, Log D, and charge characteristics. However, they were identified as governing factors affecting the removal of micropollutants by the RO. The CC-DF process might effectively remove particulate materials capable of contributing to cake layer formation on the UF membrane surfaces but the residual coagulants provided a strong effect on fouling formation of the UF membrane. Thus, hydrophobic fractions of the desorbed UF membrane foulants were higher than those of the desorbed RO membrane foulants.

  11. Cake properties in ultrafiltration of TiO2 fine particles combined with HA: in situ measurement of cake thickness by fluid dynamic gauging and CFD calculation of imposed shear stress for cake controlling.

    PubMed

    Du, Xing; Qu, Fangshu; Liang, Heng; Li, Kai; Chang, Haiqing; Li, Guibai

    2016-05-01

    In this study, the cake buildup of TiO2 fine particles in the presence of humid acid (HA) and cake layer controlling during ultrafiltration (UF) were investigated. Specifically, we measured the cake thickness using fluid dynamic gauging (FDG) method under various solution conditions, including TiO2 concentration (0.1-0.5 g/L), HA concentration (0-5 mg/L, total organic carbon (TOC)), and pH values (e.g., 4, 6 and 10), and calculated the shear stress distribution induced by stirring using computational fluid dynamics (CFD) to analyze the cake layer controlling conditions, including the operation flux (50-200 L m(-2) h(-1)) and TiO2 concentration (0.1-0.5 g/L). It was found that lower TiO2/HA concentration ratio could lead to exceedingly severe membrane fouling because of the formation of a relatively denser cake layer by filling the voids of cake layer with HA, and pH was essential for cake layer formation owing to the net repulsion between particles. Additionally, it was observed that shear stress was rewarding for mitigating cake growth under lower operation flux as a result of sufficient back-transport forces, and exhibited an excellent performance on cake layer controlling in lower TiO2 concentrations due to slight interaction forces on the vicinity of membrane.

  12. Development of a mitochondria-based centrifugal ultrafiltration/liquid chromatography/mass spectrometry method for screening mitochondria-targeted bioactive constituents from complex matrixes: Herbal medicines as a case study.

    PubMed

    Yang, Xing-Xin; Xu, Feng; Wang, Dan; Yang, Zhi-Wei; Tan, Huan-Ran; Shang, Ming-Ying; Wang, Xuan; Cai, Shao-Qing

    2015-09-25

    Mitochondria are an important intracellular pharmacological target because damage to this organelle results in a variety of human disorders and because mitochondria are involved in complex processes such as energy generation, apoptosis and lipid metabolism. To expedite the search for natural bioactive compounds targeting mitochondria, we initially developed an efficient mitochondria-based screening method by combining centrifugal ultrafiltration (CU) with liquid chromatography/mass spectrometry (LC/MS), which is called screening method for mitochondria-targeted bioactive constituents (SM-MBC) and is compatible with the search of mitochondria-targeted compounds from complex matrixes such as herbal medicines extracts. Functionally active, structurally intact and pure mitochondria were obtained from rat myocardium using an optimized protocol for mitochondrial isolation comprising organelle release followed by differential and Nycodenz density gradient centrifugation. After evaluating the reliability of the method using thiabendazole (TZ), rotenone (RN), amiodarone (AR) and trimetazidine (TD) as positive controls, this method was successfully applied to screen bioactive constituents from extracts of Polygoni Cuspidati Rhizoma et Radix (PCRR) and Scutellariae Radix (SR). Nineteen active compounds were detected and identified by LC/MS, of which 17 were new mitochondria-targeted compounds. The activity of 9 of the 19 hit compounds was confirmed by in vitro pharmacological trials. These results demonstrate that SM-MBC can be used for the efficient screening of mitochondria-targeted constituents in complex preparations used to treat mitochondrial disorders, such as PCRR and SR. The results may be meaningful for an in-depth understanding of drug mechanism of action and drug discovery from medicinal herbs.

  13. Laboratory and pilot-scale dead-end ultrafiltration concentration of sanitizer-free and chlorinated lettuce wash water for improved detection of Escherichia coli O157:H7.

    PubMed

    Magaña, Sonia; Schlemmer, Sarah M; Davidson, Gordon R; Ryser, Elliot T; Lim, Daniel V

    2014-08-01

    An automated dead-end (single pass, no recirculation) ultrafiltration device, the Portable Multi-use Automated Concentration System (PMACS), was evaluated as a means to concentrate Escherichia coli O157:H7 from 40 liters of simulated commercial lettuce wash water. The assessment included generating, sieving, and concentrating sanitizer-free lettuce wash water, either uninoculated or inoculated with green fluorescent protein-transformed E. coli O157:H7 at a high (1.00 log CFU/ml) or low (-1.00 log CFU/ml) concentration. Cells collected within the filters were recovered in approximately 400 ml of buffer to create lettuce wash retentates. The extent of concentration was determined by viable plate counts using a medium selective for the transformed E. coli O157:H7. The samples were qualitatively analyzed for E. coli O157:H7 according to the U. S. Food and Drug Administration Bacteriological Analytical Manual enrichment method and with an electrochemiluminescence immunoassay. This concentration method was then evaluated in a pilot-scale production line at Michigan State University using chlorinated (100, 30, and 10 ppm of available chlorine) lettuce wash water. The total PMACS processing times were 82 ± 6 and 65 ± 5 min for sanitizer-free and chlorinated washes, respectively. Overall, E. coli O157:H7 populations were approximately 2 log higher in retentates than in unconcentrated lettuce wash samples. The higher E. coli O157:H7 levels in the retentates enabled cultural and electrochemiluminescence immunoassay detection in some samples when the corresponding lettuce wash samples were negative. When combined with standard and rapid detection methods, the PMACS concentration method may provide a means to enhance pathogen monitoring of produce wash water. PMID:25198586

  14. Pretreatment of plasma samples by a novel hollow fiber centrifugal ultrafiltration technique for the determination of plasma protein binding of three coumarins using acetone as protein binding releasing agent.

    PubMed

    Li, Junmei; Shi, Qingwen; Jiang, Ye; Liu, Yan

    2015-09-15

    A novel and practical sample pretreatment method based on hollow fiber centrifugal ultrafiltration (HFCF-UF) was developed to determine plasma protein binding by using HPLC. The samples for analyzing unbound and total concentrations could be prepared in parallel simultaneously by the same device. It only required centrifugation for a short time and the filtrate could be injected directly for HPLC analysis without further treatment. Coumarins were selected as the model drugs. Acetone was chosen as the releasing agent to free the binding drug from the drug-protein complex for the total drug concentration determination. Non-specific bindings (NSBs) between the analytes and hollow fiber membrane materials were investigated. The type and volume of protein binding releaser were optimized. Additionally, centrifugal speed and centrifugal time were considered. Under the optimized conditions, the absolute recovery rates of the unbound and total concentrations were in the range of 97.5-100.9% for the three analytes. The limits of detection were in the range of 0.0135-0.0667μgmL(-1). In vitro plasma protein binding of the three coumarins was determined at three concentrations using the validated method and the relative standard deviations (RSDs) were less than 3.4%. Compared with traditional method, the HFCF-UF method is simple to run, no specialized equipment requirement and is a more accurate plasma pretreatment procedure with almost excellent drug-protein binding equilibrium. Therefore, this method can be applied to determine the plasma protein binding in clinical practice. It also provides a reliable alternative for accurate monitoring of unbound or total drug concentration in therapeutic drug monitoring (TDM).

  15. Laboratory and pilot-scale dead-end ultrafiltration concentration of sanitizer-free and chlorinated lettuce wash water for improved detection of Escherichia coli O157:H7.

    PubMed

    Magaña, Sonia; Schlemmer, Sarah M; Davidson, Gordon R; Ryser, Elliot T; Lim, Daniel V

    2014-08-01

    An automated dead-end (single pass, no recirculation) ultrafiltration device, the Portable Multi-use Automated Concentration System (PMACS), was evaluated as a means to concentrate Escherichia coli O157:H7 from 40 liters of simulated commercial lettuce wash water. The assessment included generating, sieving, and concentrating sanitizer-free lettuce wash water, either uninoculated or inoculated with green fluorescent protein-transformed E. coli O157:H7 at a high (1.00 log CFU/ml) or low (-1.00 log CFU/ml) concentration. Cells collected within the filters were recovered in approximately 400 ml of buffer to create lettuce wash retentates. The extent of concentration was determined by viable plate counts using a medium selective for the transformed E. coli O157:H7. The samples were qualitatively analyzed for E. coli O157:H7 according to the U. S. Food and Drug Administration Bacteriological Analytical Manual enrichment method and with an electrochemiluminescence immunoassay. This concentration method was then evaluated in a pilot-scale production line at Michigan State University using chlorinated (100, 30, and 10 ppm of available chlorine) lettuce wash water. The total PMACS processing times were 82 ± 6 and 65 ± 5 min for sanitizer-free and chlorinated washes, respectively. Overall, E. coli O157:H7 populations were approximately 2 log higher in retentates than in unconcentrated lettuce wash samples. The higher E. coli O157:H7 levels in the retentates enabled cultural and electrochemiluminescence immunoassay detection in some samples when the corresponding lettuce wash samples were negative. When combined with standard and rapid detection methods, the PMACS concentration method may provide a means to enhance pathogen monitoring of produce wash water.

  16. Separation and purification of α-glucosidase inhibitors from Polygonatum odoratum by stepwise high-speed counter-current chromatography combined with Sephadex LH-20 chromatography target-guided by ultrafiltration-HPLC screening.

    PubMed

    Zhou, Xiaoling; Liang, Junsheng; Zhang, Yi; Zhao, Huading; Guo, Ying; Shi, Shuyun

    2015-03-15

    Although Polygonatum odoratum has been widely used as medicinal plant and food supplement for treating diabetes, little is known regarding its bioactive components. In this study, ultrafiltration-HPLC based ligand screening was developed to screen α-glucosidase inhibitors from P. odoratum for the first time. Then bioactive components were target-guided separated by combining stepwise high-speed counter-current chromatography (HSCCC) using petroleum ether-ethyl acetate-methanol-water (1:4:0.8:4.2, v/v/v/v), (1:4:1.8:3.2, v/v/v/v) and (1:4:2.3:2.7, v/v/v/v) as solvent systems with Sephadex LH-20 chromatography eluted by MeCN-MeOH (1:1, v/v). Five phenethyl cinnamides, N-cis-feruloyloctopamine (1); N-trans-p-coumaroyloctopamine (2), N-trans-feruloyloctopamine (3), N-trans-p-coumaroyltyramine (4) and N-trans-feruloyltyramine (5), and four homoisoflavanones, (3R)-5,7-dihydroxyl-3-(2',4'-dihydroxylbenzyl)-chroman-4-one (6), (3R)-5,7-dihydroxyl-6-methyl-3-(4'-hydroxylbenzyl)-chroman-4-one (7), (3R)-5,7-dihydroxyl-6-methyl-8-methoxyl-3-(4'-hydroxylbenzyl)-chroman-4-one (8); and (3R)-5,7-dihydroxyl-6,8-dimethyl-3-(4'-hydroxylbenzyl)-chroman-4-one) (9), with purity over 98.5% were purified, and their structures were identified by UV, MS, and (1)H NMR. Notably, compounds 2 and 4 were first reported in genus Polygonatum, while compound 1 was first obtained from family Liliaceae. In addition, α-glucosidase inhibitory activities of compounds 1-9 were evaluated, and compounds 2 and 4 exhibited stronger α-glucosidase inhibitory activity with IC50 values of 2.3 and 2.7μM. The results suggested the potential medicinal use of P. odoratum, and the technology could be widely applied for rapid screening and preparative separation of a group of bioactive compounds from complex matrix.

  17. An eco-friendly stability-indicating spectrofluorimetric method for the determination of two anticancer stereoisomer drugs in their pharmaceutical preparations following micellar enhancement: Application to kinetic degradation studies

    NASA Astrophysics Data System (ADS)

    El-Kimary, Eman I.; El-Yazbi, Amira F.

    2016-06-01

    A new rapid and highly sensitive stability-indicating spectrofluorimetric method was developed for the determination of two stereoisomers anticancer drugs, doxorubicin (DOX) and epirubicin (EPI) in pure form and in pharmaceutical preparations. The fluorescence spectral behavior of DOX and EPI in a sodium dodecyl sulfate (SDS) micellar system was investigated. It was found that the fluorescence intensity of DOX and EPI in an aqueous solution of phosphate buffer pH 4.0 and in the presence of SDS was greatly (about two fold) enhanced and the mechanism of fluorescence enhancement effect of SDS on DOX was also investigated. The fluorescence intensity of DOX or EPI was measured at 553 nm after excitation at 497 nm. The plots of fluorescence intensity versus concentration were rectilinear over a range of 0.03-2 μg/mL for both DOX and EPI with good correlation coefficient (r > 0.999). High sensitivity to DOX and EPI was attained using the proposed method with limits of detection of 10 and 9 ng/mL and limits of quantitation of 29 and 28 ng/mL, for DOX and EPI, respectively. The method was successfully applied for the determination of DOX and EPI in biological fluids and in their commercial pharmaceutical preparations and the results were concordant with those obtained using a previously reported method. The application of the proposed method was extended to stability studies of DOX following different forced degradation conditions (acidic, alkaline, oxidative and photolytic) according to ICH guidelines. Moreover, the kinetics of the alkaline and oxidative degradation of DOX was investigated and the apparent first-order rate constants and half-life times were calculated.

  18. An eco-friendly stability-indicating spectrofluorimetric method for the determination of two anticancer stereoisomer drugs in their pharmaceutical preparations following micellar enhancement: Application to kinetic degradation studies.

    PubMed

    El-Kimary, Eman I; El-Yazbi, Amira F

    2016-06-15

    A new rapid and highly sensitive stability-indicating spectrofluorimetric method was developed for the determination of two stereoisomers anticancer drugs, doxorubicin (DOX) and epirubicin (EPI) in pure form and in pharmaceutical preparations. The fluorescence spectral behavior of DOX and EPI in a sodium dodecyl sulfate (SDS) micellar system was investigated. It was found that the fluorescence intensity of DOX and EPI in an aqueous solution of phosphate buffer pH4.0 and in the presence of SDS was greatly (about two fold) enhanced and the mechanism of fluorescence enhancement effect of SDS on DOX was also investigated. The fluorescence intensity of DOX or EPI was measured at 553nm after excitation at 497nm. The plots of fluorescence intensity versus concentration were rectilinear over a range of 0.03-2μg/mL for both DOX and EPI with good correlation coefficient (r>0.999). High sensitivity to DOX and EPI was attained using the proposed method with limits of detection of 10 and 9ng/mL and limits of quantitation of 29 and 28ng/mL, for DOX and EPI, respectively. The method was successfully applied for the determination of DOX and EPI in biological fluids and in their commercial pharmaceutical preparations and the results were concordant with those obtained using a previously reported method. The application of the proposed method was extended to stability studies of DOX following different forced degradation conditions (acidic, alkaline, oxidative and photolytic) according to ICH guidelines. Moreover, the kinetics of the alkaline and oxidative degradation of DOX was investigated and the apparent first-order rate constants and half-life times were calculated.

  19. Rapid purification of fluorescent enzymes by ultrafiltration

    NASA Technical Reports Server (NTRS)

    Benjaminson, M. A.; Satyanarayana, T.

    1983-01-01

    In order to expedite the preparation of fluorescently tagged enzymes for histo/cytochemistry, a previously developed method employing gel column purification was compared with a more rapid modern technique using the Millipore Immersible CX-ultrafilter. Microscopic evaluation of the resulting conjugates showed comparable products. Much time and effort is saved using the new technique.

  20. Rapid purification of fluorescent enzymes by ultrafiltration

    NASA Technical Reports Server (NTRS)

    Benjaminson, M. A.; Satyanarayana, T.

    1983-01-01

    In order to expedite the preparation of fluorescently tagged enzymes for histo-cyctochemistry, a previously developed method employing gel column purification was compared with a more rapid modern technique using the Millipore Immersible CX-ultrafilter. Microscopic evaluation of the resulting conjugates showed comparable products. Much time and effort is saved using the new technique.

  1. Ultrafiltration of Protein Solutions: A Laboratory Experiment

    ERIC Educational Resources Information Center

    Pansare, Vikram J.; Tien, Daniel; Prud'homme, Robert K.

    2015-01-01

    Biology is playing an increasingly important role in the chemical engineering curriculum. We describe a set of experiments we have implemented in our Undergraduate Laboratory course giving students practical insights into membrane separation processes for protein processing. The goal of the lab is to optimize the purification and concentration of…

  2. A critical evaluation of drug delivery from ligand modified nanoparticles: Confounding small molecule distribution and efficacy in the central nervous system.

    PubMed

    Cook, Rebecca L; Householder, Kyle T; Chung, Eugene P; Prakapenka, Alesia V; DiPerna, Danielle M; Sirianni, Rachael W

    2015-12-28

    In this work, we sought to test how surface modification of poly(lactic-co-glycolic acid) (PLGA) nanoparticles with peptide ligand alters the brain specific delivery of encapsulated molecules. For biodistribution studies, nanoparticles modified with rabies virus glycoprotein (RVG29) were loaded with small molecule drug surrogates and administered to healthy mice by lateral tail vein injection. Mice were perfused 2h after injection and major anatomical regions of the CNS were dissected (striatum, midbrain, cerebellum, hippocampus, cortex, olfactory bulb, brainstem, and cervical, thoracic, lumbar and sacral spinal cord). For functional studies, surface modified nanoparticles were loaded with the chemotherapeutic camptothecin (CPT) and administered to mice bearing intracranial GL261-Luc2 gliomas. Outcome measures included tumor growth, as measured by bioluminescent imaging, and median survival time. We observed that small molecule delivery from PLGA nanoparticles varied by as much as 150% for different tissue regions within the CNS. These differences were directly correlated to regional differences in cerebral blood volume. Although the presence of RVG29 enhanced apparent brain delivery for multiple small molecule payloads, we observed minimal evidence for targeting to muscle or spinal cord, which are the known sites for rabies virus entry into the CNS, and enhancements in brain delivery were not prolonged due to an apparent aqueous instability of the RVG29 ligand. Furthermore, we have identified concerning differences in apparent delivery kinetics as measured by different payloads: nanoparticle encapsulated DiR was observed to accumulate in the brain, whereas encapsulated Nile red was rapidly cleared. Although systemically administered CPT loaded nanoparticles slowed the growth of orthotopic brain tumors to prolong survival, the presence of RVG29 did not enhance therapeutic efficacy compared to control nanoparticles. These data are consistent with a model of delivery of hydrophobic small molecules to the brain that does not rely on internalization of polymer nanoparticles in target tissue. We discuss an important risk for discordance between biodistribution, as typically measured by drug surrogate, and therapeutic outcome, as determined by clinically relevant measurement of drug function in a disease model. These results pose critical considerations for the methods used to design and evaluate targeted drug delivery systems in vivo.

  3. Histamine H3 and H4 receptor ligands modify vascular histamine levels in normal and arthritic large blood vessels in vivo.

    PubMed

    Kyriakidis, Konstantinos; Zampeli, Evangelia; Palaiologou, Marina; Tiniakos, Dina; Tiligada, Ekaterini

    2015-01-01

    Growing evidence associates histamine with arthritis, but its implication in shaping vascular function in chronic inflammation remains largely elusive. This study explored the involvement of vascular histamine in the extra-articular responses in peripheral large blood vessels using a rat model of adjuvant-induced arthritis. Histamine levels were increased in the abdominal aorta and the inferior vena cava of arthritic animals. Contrary to the H1 receptor antagonist dimetindene, histamine induction was observed following administration of the H3 and H4 receptor ligands GSK334429 and JNJ7777120, respectively. In arthritis, prophylactic treatment with GSK334429 partially attenuated the clinical signs and restored basal histamine levels only in the abdominal aorta. This study is the first to implicate the H3 and H4 receptors in a concerted constitutive regulation of basal vascular histamine in the rat large blood vessels and to identify the H3 receptor as a component that may influence arterial histamine during the onset of arthritis.

  4. χ{sup (3)} measurements of axial ligand modified high valent tin(IV) porphyrins using degenarete four wave mixing at 532nm

    SciTech Connect

    Narendran, N. K. Siji Chandrasekharan, K.; Soman, Rahul; Arunkumar, Chellaiah; Sudheesh, P.

    2014-10-15

    Porphyrins and metalloporphyrins are unique class of molecules for Nonlinear Optical applications because of their unique structure of altering the central metal atom, large extended π-system, high thermal stability, tunable shape, symmetry and synthetic versatility Here, we report χ{sup (3)} Measurements of a simple phenyl porphyrins and its highvalent tin(IV) porphyrins with Bromination characterized by UV-Visible spectroscopic method. In this study, we employed the Degenerate Four Wave Mixing technique using forward Boxcar geometry with an Nd:YAG nano second pulsed laser as source and it was found that the tin(IV) porphyrin with Bromination exhibits good χ{sup (3)} value and figure of merit.

  5. Novel homo-bimetallic complexes of [N 10] macrocyclic ligand modified with tetrapeptide function: Biological activities, spectral and cyclic voltammetric studies

    NASA Astrophysics Data System (ADS)

    Siddiqi, Zafar A.; Kumar, Sarvendra; Khalid, Mohd.; Shahid, M.

    2009-06-01

    The bimetallic complexes [M 2LCl 4] (M = Cr, Co, Ni, Cu) prepared via metal template cyclization reactions were characterized by physico-chemical and spectroscopic methods. L is a 30-membered [N 10] macrocycle with tetraamide functions bind metal ions through aza donors forming hexa-coordinate geometry. The perspective view and important structural parameters have been computed from the molecular model (MOPAC) method. The electrochemical studies indicate existence of quasi-reversible redox couples in solution. The metal complexes were screened (in vitro) against a few pathogenic fungi and bacteria to assess their growth inhibiting potential.

  6. Aetervinning av faerg och ridaevatten med ultrafiltrering (recycling of paint and water curtains with ultrafiltration)

    SciTech Connect

    Fortkamp, U.; Allard, A.S.; Ekengren, O.

    1997-12-01

    Painting in spray booths causes overspray that is collected by a water curtain. The mixture of water and paint is commonly treated by means of precipitation. By means of this method, water can be used again but a paint sludge is created. Within this project, it was investigated how the paint as well as the water can be recycled. Separation by membrane filtration was tested for different paints in laboratory scale (0.2 liter volume). It was possible to separate all tested paints from the water and to concentrate it. At large scale (15 to 75 liters volume), an emulsion paint and a dispersion paint were tested. Under the tested conditions, it was slightly easier to concentrate the emulsion paint than the dispersion paint. It was possible to concentrate the paints to the original dry substance percentage. An important aspect of membrane filtration is cleaning of the membrane when the performance decreases. It was possible to clean all the tested membranes, but in many cases it was difficult. A ceramic membrane and a membrane of polyaramide showed the best results with regard to flux and cleaning of the membrane under the tested conditions. During the performance of the project two new applications of membrane filtration of paint were found. The method can be used for waste minimization by only separating the paint in an easy way at low costs. A third application is treating cleaning water from paint manufacturing.

  7. 21 CFR 177.2910 - Ultra-filtration membranes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... with zirconium oxide (CAS Reg. No. 1314-23-4) containing up to 12 percent yttrium oxide (CAS Reg. No... with zirconium oxide (CAS Reg. No. 1314-23-4) containing up to 5 percent yttrium oxide (CAS Reg....

  8. Alternative Ultrafiltration Membrane Testing for the SRS Baseline Process

    SciTech Connect

    N. R. Mann; R. S. Herbst; T. G. Garn; M. R. Poirier; S. D. Fink

    2004-06-01

    The ability to more rapidly process high-level waste sludge and supernate, without sacrificing cost savings, continues to be a crucial challenge facing the Savannah River Site (SRS). There has, to date, not been any extensive investigation of alternative filter technologies for the SRS baseline process. To address this problem, a focused investigation into alternative, state-of-the art filtration technologies to facilitate the strontium and actinide removal process, which can be cost effectively implemented in existing facilities and current equipment designs, was completed. Filter technologies manufactured by Mott (0.1 µm and 0.5 µm) Graver (0.07 µm), Pall (0.1 µm and 0.8 µm) and GKN (0.1 µm) were evaluated. Membranes had a nominal inside diameter of 3/8 inches and an active membrane length of 2 feet. The investigation was performed in two phases. The first phase of testing evaluated the consistency or variability in flux through the different membranes using water and a standard 5.0 wt% strontium carbonate slurry. The second phase of testing evaluated the achievable permeate flux and clarity through the various membranes using the SRS average salt supernate simulant at solids loadings of 0.06, 0.29 and 4.5 wt%. Membrane variation data indicate that membranes having an asymmetric ceramic coating (Pall 0.1 µm and Graver 0.07 µm), typically displayed the lowest variability with water. Membranes without a ceramic asymmetric coating (Mott 0.5 µm and GKN 0.1 µm) displayed the highest variability. This is most likely associated with the experimental uncertainties in measuring large volumes of permeate in a short amount of time and to the impact of impurities in the water. In general, variability ranging from 4-56% was observed when using water for all membranes. In the case of variation testing using strontium carbonate, variability decreased to 3-12%. In addition, membrane structure or composition had little effect on the variability. Data obtained from SRS simulant testing, indicate that membranes having a ceramic asymmetric coating (Graver 0.07 µm, Pall 0.1 µm), typically achieved the highest average steady state fluxes for all solution concentrations evaluated. In general, the Graver 0.07 µm and Pall 0.1 µm membranes achieved fluxes approximately 13 to 21 percent higher than those observed with the baseline Mott 0.1 µm membrane using the SRS simulant at solids loadings of 0.29 and 4.5 wt%. Membranes without a ceramic asymmetric coating (GKN, Mott) achieved the lowest average steady state fluxes. It is postulated that small particles present in solution were unable to penetrate the ceramic layer, thus producing surface filtration where the filter cake acts as the filter medium. Conversely, membranes without the asymmetric ceramic coating were susceptible to the small particles present in solution penetrating into the internal pore structure of the membrane, thus producing depth filtration where the porosity is greatly reduced by particles trapped within the interstices of the internal structure. Turbidity data indicate that permeate from the alternative membranes provided reduced or equivalent turbidity measurements when compared to the baseline 0.1 µm Mott membrane.

  9. Effective cleaning and sanitizing of polysulfone ultrafiltration membrane systems.

    PubMed

    Bohner, H F; Bradley, R L

    1992-03-01

    Polysulfone UF membranes that were soiled by Cheddar cheese whey were successfully cleaned in place. This cleaning procedure was completed in about 1 h. Most cleaning chemicals used were common and inexpensive. The cleaning procedure consisted of rinsing the membrane system for 2 min with water initially and after each cleaning solution. Sodium hydroxide at pH 11.0, with .1% of a nonionic surfactant added, was circulated for 20 min. After a 2-min rinse with water, a 1:1 mixture of nitric and phosphoric acids at pH 2 was circulated for 20 min and rinsed again with water. Finally, sodium hydroxide at pH 11.0, with 200 ppm of sodium hypochlorite added, was circulated for 20 min and rinsed. All cleaning solutions and all rinse waters were at 54 degrees C. Membranes cleaned by this procedure were found to be free from whey residue under examination by scanning electron microscopy. The cleaning process did not damage the membranes even when it was used continuously for 300 h. Microbial populations on the membrane were estimated by incubating small (4-cm2) sections of membrane in screw-cap vials filled with trypticase soy broth. From the portion of vials showing growth after 72 h at 32 degrees C, a most probable microbial population was calculated. Santizing cleaned polysulfone UF membranes with 100 ppm of sodium hypochlorite or 100 ppm of dichloroisocyanurate at 54 degrees C resulted in membranes free from viable microorganisms. When dichloroisocyanurate was used at 10 degrees C and 200 ppm, a most probable microbial population of 290/m2 was found. No microbial growth was detected when cleaned and sanitized membranes were stored in tap water for 24 h. This technique for cleaning UF membranes does not require the use of a holding solution containing santizers to control the growth of residual microorganisms. PMID:1569262

  10. Ultrafiltration behaviors of alginate blocks at various calcium concentrations.

    PubMed

    Meng, Shujuan; Winters, Harvey; Liu, Yu

    2015-10-15

    Alginate, a linear copolymer, is composed of 1,4-linked β-d-mannuronic acid (M) and α-l-guluronic acid (G), which are combined into homopolymeric blocks (MM-block and GG-block) and heteropolymeric block (MG-block). It has been widely used as a model foulant in various studies of membrane fouling, thus this study investigated the impacts of calcium ion on MG-, MM- and GG-blocks of alginate and the filtration behaviors of the three types of alginate blocks at different concentrations of calcium ion. Results showed that calcium ion had the most serious effects on GG-blocks and significantly promotes the formation of transparent exopolymeric particles (TEP) from GG-blocks which in turn led to rapid formation of thick cake layer on membrane surface during the filtration of GG-blocks. As for MM-blocks, it was found that the formation of TEP was proportional to the Ca(2+) concentration in MM-blocks solution, while the membrane fouling was enhanced by Ca(2+) in the filtration of MM-blocks solution. Unlike MM- and GG-blocks, MG-blocks were nearly not affected by addition of calcium ion, as the result, there was no significant increase in TEP. The initial fouling rates and the mass of foulants deposed on the membrane surfaces further revealed a close correlation between the TEP concentration and the membrane fouling propensity. The observations by field emission scanning electron microscope (FESEM) and atomic force microscope (AFM) further confirmed the formation process of the cake layer by TEP on the membrane surface. This study offers deep insights into the development of membrane fouling by different alginate blocks in the presence of calcium ion, and suggests that TEP formed from alginate blocks played a very significant role in the fouling development.

  11. The use of micellar solutions for novel separation techniques

    SciTech Connect

    Roberts, B.L.

    1993-12-31

    Surfactant based separation techniques based on the solubilization of organic compounds into the nonpolar interior of a micelle or electrostatic attraction of ionized metals and metal complexes to the charged surface of a micelle were studied in this work. Micellar solutions were used to recover two model volatile organic compounds emitted by the printing and painting industries (toluene and amyl acetate) and to investigate the effect of the most important variables in the surfactant enhanced carbon regeneration (SECR) process. SECR for liquid phase applications was also investigated in which the equilibrium adsorption of cetyl pyridinium chloride (CPC) and sodium dodecyl sulfate (SDS) on activated carbon were measured. Micellar-enhanced ultrafiltration (MEUF) was investigated using spiral wound membranes for the simultaneous removal of organic compounds, metals and metal complexes dissolved in water, with emphasis on pollution control applications. Investigations of MEUF to remove 99+ per cent of trichloroethylene (TCE) from contaminated groundwater using criteria such as: membrane flux, solubilization equilibrium constant, surfactant molecular weight, and Krafft temperature led to the selection of an anionic disulfonate with a molecular weight of 642 (DOWFAX 8390). These data and results from supporting experiments were used to design a system which could clean-up water in a 100,000 gallon/day operation. A four stage process was found to be an effective design and estimated cost for such an operation were found to be in the range of the cost of mature competitive technologies.

  12. Removal of Viruses in Drinking Water- Ultrafiltration Module with a Cut Fiber, Dow Chemical Company - Dow Water & Process Solutions, SFD-2880 - Ultrafiltration Module

    EPA Science Inventory

    The purpose of this verification was a cut fiber challenge study for the Dow Chemical Company SFD-2880 UF membrane module. MS2 coliphage virus was the surrogate challenge organism. The challenge tests followed the requirements of the Department of Health Victoria (Australia) Dr...

  13. Partition coefficients of ionizable solutes in mixed nonionic/ionic micellar systems.

    PubMed

    Mehling, Tanja; Kloss, Linda; Ingram, Thomas; Smirnova, Irina

    2013-01-29

    Surfactant solutions in practical applications usually are mixtures of ionic and nonionic surfactants. Because of synergistic effects, the solubilization of hydrophobic compounds can be enhanced while decreasing the needed amount of surfactant at the same time. In this work, the influence of the composition of Brij 35/CTAB and Brij 35/SDS mixed micelles on the partition coefficient log D(MW) of various acids and bases over the entire pH range was investigated. Two experimental methods (MLC, micellar liquid chromatography; MEUF, micellar enhanced ultrafiltration) are evaluated for the determination of partition coefficients in mixed-micelle systems. Although MLC stands out because of its automation and easy handling, MEUF is applicable to a broader log D(MW) range. It is shown that the partitioning can be influenced dramatically by the two investigated parameters. By adjusting the pH value and the composition of the micelles, we can tailor the partition behavior of solutes for virtually any application. The thermodynamic model COSMO-RS gives valuable predictions of the partition coefficients if the composition of the micelle is available. Different approaches for the description of the micellar composition are evaluated in this work. On the basis of the cmc value of the single surfactants and the mixture only, it is shown that the regular solution approximation gives reasonable micellar compositions. The partition coefficients between water and the mixed micelles are predicted with the COSMO-RS model, in good agreement with the experimental data. Moreover, the micellar composition can be evaluated by fitting the prediction to the experimentally determined partition coefficients. PMID:23237203

  14. The "Red Lady" ages gracefully: new ultrafiltration AMS determinations from Paviland.

    PubMed

    Jacobi, R M; Higham, T F G

    2008-11-01

    The "Red Lady" partial human skeleton found at Goat's Hole, Paviland, in south Wales by William Buckland in 1823 is one of the iconic relics of the British Paleolithic. Originally thought to be Roman, a Paleolithic age has been suspected from the middle of the 19th century. Several attempts have been made at directly radiocarbon dating the "Red Lady," and here we report new determinations that suggest that it is, by a significant margin, the oldest of a group of 'rich,' Mid-Upper Paleolithic burials. We list similar Gravettian-aged burials from Europe, which have been dated recently for comparison. In this paper, we also reconsider the chronology of human use of the cave, apart from as a burial location.

  15. Preparation of antifouling polyvinylpyrrolidone (PVP 40K) modified polyethersulfone (PES) ultrafiltration (UF) membrane for water purification

    NASA Astrophysics Data System (ADS)

    Vatsha, Banele; Ngila, Jane Catherine; Moutloali, Richard M.

    This study reports the fabrication of polyethersulfone (PES) membrane using the phase inversion method in the presence of polyvinylpyrrolidone (PVP, 40K) as pore-forming agent. The membranes were made from two PES concentration types, i.e. 16 and 18 wt.%. The effect of high molecular weight PVP concentration (2-10%) was examined in order to obtain a membrane with good performance, i.e. high water flux and reasonable Bovine Serum Albumin (BSA, protein model solution) rejection. The optimised membranes were characterised by ATR-FTIR, AFM, SEM, contact angle and dead-end membrane filtration tests. It was found that PVP moieties have positive influence in the prepared PES membranes. SEM surface and cross-sectional images were used to observed morphological changes as PVP content was varied. The pore sizes increased with PVP content for membranes prepared from 16 wt.% PES polymer, whereas at the higher PVP content in 18 wt.% PES membrane, pore sizes tend to decrease or completely disappear. The CA decreased gradually for the 16 wt.% PES with increasing PVP content whereas in the 18 wt.% PES the CA decreased initially before tapering off or increasing slightly. The rejection of BSA solution by both neat PES and PVP-containing PES membrane was above 85%. AFM surface topography exhibited increase in roughness value with PVP content. FTIR/ATR spectra corroborated the functional composition of neat PES and PVP molecule dispersed on PES membrane backbone. The results attained confirmed the potential industrial application of PVP molecule to minimise fouling tendencies.

  16. Assessment of a Point-of-Use Ultrafiltration System for Turbidity and Microbial Pathogen Removal

    EPA Science Inventory

    U.S. EPA’s Office of Research and Development has been evaluating the performance of point-of-use (POU) devices designed for use in homes and small businesses for many years. In collaboration with the University of Cincinnati, a series of pilot-scale tests were conducted on a Mat...

  17. Study on performance of ultrafiltration membrane-based pretreatment for application to seawater reverse osmosis desalination.

    PubMed

    Tansakul, C; Laborie, S; Cabassud, C

    2010-01-01

    The objective of the work was to study at lab-scale the efficiency of hybrid process- coupling powdered activated carbon (PAC) adsorption or FeCl(3) coagulation and UF- for marine organic matter removal. Regenerated cellulose membrane with 30 kDa and actual seawater from Mediterranean Sea were used. The coagulant was FeCl(3) and adsorbents were two PAC types, with different surface area and pore size distribution. The results showed that PAC adsorption/UF performed higher efficiency in terms of organic removal than FeCl(3) coagulation/UF. Organic matter removal up to 50% was obtained for a PAC dose of 200 mg/L. According to high performance size exclusion chromatography (HP-SEC) analysis, the organics removed by PAC/UF are approximately 10 kDa. Therefore, the effect of PAC adsorption was deeply evaluated in terms of UF membrane fouling rate. The fouling rate was reduced when increasing PAC dose for both PAC types, in particular when PAC with a higher BET surface area and larger fraction of micropores was used. On the other hand, the results showed that UF unit could highly reduce SDI(3) from 26 to 9. The addition of PAC and FeCl(3) to UF allowed a further reduction of SDI(3) from 9 to 4-6. PMID:21045322

  18. An asymptotic description of transient settling and ultrafiltration of colloidal dispersions

    NASA Technical Reports Server (NTRS)

    Davis, K. E.; Russel, W. B.

    1989-01-01

    The present model for the sedimentation of colloidal systems includes a diffusion term in the governing equation which, in the regions above the sediment, acts as small perturbation to the Kynch (1952) theory. Within the sediment, diffusion is comparable to convection due to the the high solid volume fraction. An application of the method of matched asymptotic expansions to the conservation equation allows a complete description of the settling process to be formulated, with specific attention to volume-fraction evolution in the sediment.

  19. Novel Fouling-Reducing Coatings for Ultrafiltration, Nanofiltration, and Reverse Osmosis Membranes

    SciTech Connect

    Benny Freeman

    2008-08-31

    Polymeric membranes could potentially be the most flexible and viable long-term strategy for treatment of produced water from oil and gas production. However, widespread use of membranes, including reverse osmosis (RO) membranes, for produced water purification is hindered due to fouling caused by the impurities present in the water. Fouling of RO membranes is likely caused by surface properties including roughness, hydrophilicity, and charge, so surface modification is the most widely considered approach to improve the fouling properties of current RO membranes. This project focuses on two main approaches to surface modification: coating and grafting. Hydrophilic coating and grafting materials based on poly(ethylene glycol) (PEG) are applied to commercial RO membranes manufactured by Dow FilmTec and GE. Crossflow filtration experiments are used to determine the fouling resistance of modified membranes, and compare their performance to that of unmodified commercial RO membranes. Grafting and coating are shown to be two alternative methods of producing modified membranes with improved fouling resistance.

  20. Removal of phenyl-urea herbicides in ultrapure water by ultrafiltration and nanofiltration processes.

    PubMed

    Benitez, F Javier; Acero, Juan L; Real, Francisco J; Garcia, Carolina

    2009-02-01

    Membrane filtration of four phenyl-urea herbicides (linuron, diuron, chlortoluron, and isoproturon) dissolved in ultrapure water was studied in a laboratory cross-flow device in batch concentration mode (with recycling of the retentate stream). Three UF (MWCO of 20 000, 5000 and 2000Da) and three NF (MWCO of 150-300Da) membranes were used. The influence of the main operating conditions (transmembrane pressure, tangential velocity, temperature, pH, and MWCO of the membranes) on the steady-state permeate fluxes and the retention factors of the phenyl-ureas was evaluated. The herbicide mass adsorbed onto the membranes was also determined, and the contribution of the fouling resistance to the total resistance to permeate flux was much lower than the inherent resistance of the clean membranes.

  1. The use of ultrafiltration and nanofiltration membranes for the purification of cork processing wastewater.

    PubMed

    Benítez, F Javier; Acero, Juan L; Leal, Ana I; González, Manuel

    2009-03-15

    Filtration experiments in batch concentration mode (with recycling of the retentate stream) of the cork processing wastewater were performed in laboratory filtration membrane equipment, by using four commercial membranes: two UF membranes with MWCO of 20,000 and 5000 Da, and two NF membranes with an approximate MWCO of 150-300 Da. The filtration experiments of the selected wastewater were performed by modifying the most important operating variables: transmembrane pressure, tangential velocity, temperature, and the nature and MWCO of the membranes. The evolution of the cumulative permeate volumes and permeate fluxes with processing time were analysed, and it was established that the steady-state permeate flux was reached for a volume retention factor of 2. The effect of the mentioned operating conditions on this steady-state permeate flux was discussed. The effectiveness of the filtration treatments was determined by the evaluation of the rejection coefficients for several parameters, which measure the global pollutant content of the effluent: COD, absorbance at 254 nm, tannic content, color, and ellagic acid. Finally, the resistances in series model was used for the evaluation of the resistances to the permeate flux, and it was concluded that the contribution to the total resistance of the fouling resistance (combined external plus internal) was higher than the inherent resistance of the clean membrane.

  2. Synthesis of PVDF ultrafiltration membranes supported on polyester fabrics for separation of organic matter from water

    NASA Astrophysics Data System (ADS)

    Mhlanga, Sabelo D.; Tshabalala, Tumelo G.; Nxumalo, Edward N.; Mamba, Bhekie B.

    2014-08-01

    Polyvinylidene flouride (PVDF) membranes supported on non-woven fabrics (NWF) of polyester are reported. The PVDF membranes were fabricated using the phase inversion method followed by modification of the active top layer of the PVDF thin film by adding polyvinylpyrolidone (PVP) into the cast solution. A PVDF resin was used with N- methyl-2-pyrrolidone (NMP) as a solvent. Sessile drop contact angle measurements and scanning electron microscopy (SEM) were used to study the physical properties of the membranes. Membrane rejection of humic acid was studied using a cross-flow membrane testing unit. The contact angle results revealed that the hydrophilicity of PVDF membranes increased as the PVP concentration was increased from 3 to 10 wt%. SEM analysis of the membranes revealed that the membrane pore sizes increased when PVP was added. AFM analysis also showed that membrane roughness changed when PVP was added. Total organic carbon (TOC) analysis of water samples spiked with humic acid was performed to test the rejection capacity of the membranes. Rejections of up to 97% were achieved for PVDF membranes supported on polyester NWF1, which had smaller thickness and higher permeability compared to polyester NWF2. The NWFs provided the high strength required for the membranes despite the modifications done on the PDVF surface and microstructure.

  3. Study on performance of ultrafiltration membrane-based pretreatment for application to seawater reverse osmosis desalination.

    PubMed

    Tansakul, C; Laborie, S; Cabassud, C

    2010-01-01

    The objective of the work was to study at lab-scale the efficiency of hybrid process- coupling powdered activated carbon (PAC) adsorption or FeCl(3) coagulation and UF- for marine organic matter removal. Regenerated cellulose membrane with 30 kDa and actual seawater from Mediterranean Sea were used. The coagulant was FeCl(3) and adsorbents were two PAC types, with different surface area and pore size distribution. The results showed that PAC adsorption/UF performed higher efficiency in terms of organic removal than FeCl(3) coagulation/UF. Organic matter removal up to 50% was obtained for a PAC dose of 200 mg/L. According to high performance size exclusion chromatography (HP-SEC) analysis, the organics removed by PAC/UF are approximately 10 kDa. Therefore, the effect of PAC adsorption was deeply evaluated in terms of UF membrane fouling rate. The fouling rate was reduced when increasing PAC dose for both PAC types, in particular when PAC with a higher BET surface area and larger fraction of micropores was used. On the other hand, the results showed that UF unit could highly reduce SDI(3) from 26 to 9. The addition of PAC and FeCl(3) to UF allowed a further reduction of SDI(3) from 9 to 4-6.

  4. ZENON ENVIRONMENTAL INC., ZENOGEM™ BIOLOGICAL AND ULTRAFILTRATION TECHNOLOGY; INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    This report summarizes the results of a field demonstration conducted under the SITE Program. The technology which was demonstrated was a wastewater treatment technology developed by Zenon Environmental Inc. The process, named ZenoGem™, integrates biological treatment with memb...

  5. Treatment of aluminum manufacturer coolant waste using pilot-scale ultrafiltration

    SciTech Connect

    Reed, B.E.; Carriere, P.; Dunn, C.

    1995-12-31

    Treatment of oily wastewater from aluminum rolling mill operations is an inherent problem in the aluminum fabrication industry. In this study, wastewater from the manufacturer`s processes was transferred to two holding ponds having a total capacity of about 5 million gallons and a detention time of about 10 days. In the holding ponds, free oil was allowed to rise to the surface where it was periodically removed. Wastewater from the holding ponds was withdrawn from about a depth of 9 feet and used as influent to a variety of technologies. In this paper, results from the chemical addition (CA)-dissolved air flotation (DAF) portion of the treatability study are presented.

  6. Assessment of a Point-of-Use Ultrafiltration System for Turbidity and Microbial Pathogen Removal

    EPA Science Inventory

    U.S. EPA’s Office of Research and Development has been evaluating the performance of point-of-use (POU) devices designed for use in homes and small businesses for many years. In collaboration with the University of Cincinnati, a series of pilot-scale tests were conducted on a Ma...

  7. Assessment of a Point-of-Use Ultrafiltration System for Turbidity and Microbial Pathogen Removal - Paper

    EPA Science Inventory

    U.S. EPA’s Office of Research and Development has been evaluating the performance of point-of-use (POU) devices designed for use in homes and small businesses for many years. In collaboration with the University of Cincinnati, a series of pilot-scale tests were conducted on a Ma...

  8. Hydrophilic fraction of natural organic matter causing irreversible fouling of microfiltration and ultrafiltration membranes.

    PubMed

    Yamamura, Hiroshi; Okimoto, Kenji; Kimura, Katsuki; Watanabe, Yoshimasa

    2014-05-01

    Although membrane filtration is a promising technology in the field of drinking water treatment, persistent membrane fouling remains a major disadvantage. For more efficient operation, causative agents of membrane fouling need to be identified. Membrane fouling can be classified into physically reversible and irreversible fouling on basis of the removability of the foulants by physical cleaning. Four types of natural organic matter (NOM) in river water used as a source of drinking water were fractionated into hydrophobic and hydrophilic fractions, and their potential to develop irreversible membrane fouling was evaluated by a bench-scale filtration experiment together with spectroscopic and chromatographic analyses. In this study, only dissolved NOM was investigated without consideration of interactions of NOM fractions with particulate matter. Results demonstrated that despite identical total organic carbon (TOC), fouling development trends were significantly different between hydrophilic and hydrophobic fractions. The hydrophobic fractions did not increase membrane resistance, while the hydrophilic fractions caused severe loss of membrane permeability. These results were identical with the case when the calcium was added to hydrophobic and hydrophilic fractions. The largest difference in NOM characteristics between hydrophobic and hydrophilic fractions was the presence or absence of macromolecules; the primary constituent causing irreversible fouling was inferred to be "biopolymers", including carbohydrates and proteins. In addition, the results demonstrated that the extent of irreversible fouling was considerably different depending on the combination of membrane materials and NOM characteristics. Despite identical nominal pore size (0.1 μm), a polyvinylidene fluoride (PVDF) membrane was found to be more rapidly fouled than a PE membrane. This is probably explained by the generation of strong hydrogen bonding between hydroxyl groups of biopolymers and fluorine of the PVDF membrane. On the basis of these findings, it was suggested that the higher fouling potential of the hydrophilic fraction of the dissolved NOMs from various natural water sources are mainly attributed to macromolecules, or biopolymers.

  9. Ultrafiltration Membrane Module Virus Reduction at Different Fluxes, and with a Cut Fiber

    EPA Science Inventory

    NSF International evaluated The Dow Chemical Company SFD-2880 UF membrane module for MS2 reduction at four different fluxes, and also with and without a cut fiber, to compare MS2 log reduction under the different scenarios. All tests were conducted in accordance with the U.S. En...

  10. Separation of water from metal working emulsions by ultrafiltration using vibratory membranes.

    PubMed

    Moulai-Mostefa, Nadji; Frappart, Matthieu; Akoum, Omar; Ding, Luhui; Jaffrin, Michel Y

    2010-05-15

    In this paper, we investigate the application of a vibratory shear-enhanced filtration system (VSEP) to separation of water from oil-in-water emulsions. The VSEP module consists in an annular membrane of 500 cm(2) area which oscillates azimuthally in its own plane with an amplitude depending upon frequency. Polyethersulfone (PES) membranes of 50 and 20 kDa were used. Test fluids consisted of oil-in-water emulsion at an oil concentration of 4% prepared from a concentrated cutting fluid. The critical flux for stable operation was investigated by increasing the permeate flux in steps while monitoring the transmembrane pressure (TMP). With a 50 kDa membrane the flux increased nonlinearly with TMP and reached 250 L h(-1)m(-2) at a TMP of 1500 kPa while permeate turbidity decayed from 1.8 to 0.9 NTU above 600 kPa from an initial emulsion turbidity of 21,900 NTU. With the 20 kDa membrane, the flux increased linearly with TMP until 1600 kPa, but the oil concentration in permeate became negligible (turbidity near zero NTU). Concentration tests showed that the flux decreased linearly with ln(VRR) where VRR is the volume reduction ratio while permeate turbidity increased exponentially to 25NTU above a VRR of 4. This work confirms the high performance of the VSEP for oil separation from water in metal working emulsions.

  11. Hydrophilic fraction of natural organic matter causing irreversible fouling of microfiltration and ultrafiltration membranes.

    PubMed

    Yamamura, Hiroshi; Okimoto, Kenji; Kimura, Katsuki; Watanabe, Yoshimasa

    2014-05-01

    Although membrane filtration is a promising technology in the field of drinking water treatment, persistent membrane fouling remains a major disadvantage. For more efficient operation, causative agents of membrane fouling need to be identified. Membrane fouling can be classified into physically reversible and irreversible fouling on basis of the removability of the foulants by physical cleaning. Four types of natural organic matter (NOM) in river water used as a source of drinking water were fractionated into hydrophobic and hydrophilic fractions, and their potential to develop irreversible membrane fouling was evaluated by a bench-scale filtration experiment together with spectroscopic and chromatographic analyses. In this study, only dissolved NOM was investigated without consideration of interactions of NOM fractions with particulate matter. Results demonstrated that despite identical total organic carbon (TOC), fouling development trends were significantly different between hydrophilic and hydrophobic fractions. The hydrophobic fractions did not increase membrane resistance, while the hydrophilic fractions caused severe loss of membrane permeability. These results were identical with the case when the calcium was added to hydrophobic and hydrophilic fractions. The largest difference in NOM characteristics between hydrophobic and hydrophilic fractions was the presence or absence of macromolecules; the primary constituent causing irreversible fouling was inferred to be "biopolymers", including carbohydrates and proteins. In addition, the results demonstrated that the extent of irreversible fouling was considerably different depending on the combination of membrane materials and NOM characteristics. Despite identical nominal pore size (0.1 μm), a polyvinylidene fluoride (PVDF) membrane was found to be more rapidly fouled than a PE membrane. This is probably explained by the generation of strong hydrogen bonding between hydroxyl groups of biopolymers and fluorine of the PVDF membrane. On the basis of these findings, it was suggested that the higher fouling potential of the hydrophilic fraction of the dissolved NOMs from various natural water sources are mainly attributed to macromolecules, or biopolymers. PMID:24565803

  12. Diuretics, Limited Ultrafiltration, and Residual Renal Function in Incident Hemodialysis Patients: A Case Series.

    PubMed

    Sjolund, Jessica; Garcia Anton, Desiree; Bayes, Liz Y; Hoekstra, Tiny; Dekker, Friedo W; Munoz Mendoza, Jair

    2016-09-01

    The effect of diuretics on residual renal function expressed as residual GFR (rGFR) and urine volume (rUV) using 24-hour urine collections has not been well examined in hemodialysis (HD) patients. We present a small (seven patient) but provocative case series describing a strikingly low rate of decline in rUV and rGFR (average of creatinine and urea clearances, 24-hour urine collections) in patients treated with increasing doses of furosemide (up to 360 mg/day) during the first 2 years after initiation of HD. Between 6 and 12 months, the mean rUV fell by 1 ml/month, whereas rGFR declined by 0.03 ml/min/1.73 m(2) /month. The mean rate of decline from 12 to 24 months for rUV (33 ml/month) and rGFR (0.02 ml/min/1.73 m(2) /month) were also low. While data are clearly limited and the observation retrospective, they are consistent with the better documented benefit of diuretics observed in end-stage renal disease patients treated with peritoneal dialysis.

  13. EVALUATION OF ULTRAFILTRATION TO RECOVER AQUEOUS IRON PHOSPHATING/DEGREASING BATH

    EPA Science Inventory

    Pollution prevention efforts studied in the report summarized here targeted the hazardous waste generated from a 5000-gal iron phosphating/degreasing bath used by a metal fabricator to clean and precondition steel parts for painting. This project was carried out in four stages: (...

  14. Analysis of backwashing efficiency in dead-end hollow-fibre ultrafiltration of anaerobic suspensions.

    PubMed

    Vera, Luisa; González, Enrique; Ruigómez, Ignacio; Gómez, Jenniffer; Delgado, Sebastián

    2015-11-01

    A novel dead-end mode operation for filtering anaerobic suspensions was investigated. In this mode, the filtration system automatically adjusted backwashing frequency to a preselected transmembrane pressure set-point. This paper discusses the effectiveness of the backwashing conditions on membrane fouling. Anaerobic suspensions from a conventional wastewater treatment plant digester were used as model suspensions for the trials carried out at lab-scale. Gas sparging aided backwashing significantly enhanced membrane cleaning efficiency. No effect of gas sparging on internal fouling was detected. Also, the cleaning efficiency linearly decreased with permeate flux. Nevertheless, due to a high increase in the reversible fouling, a reasonable net permeate flux (7.2-6.8 L/h m(2)) can be achieved when intermediate fluxes (12-16 L/h m(2)) were imposed and the higher transmembrane pressure set-point value (50 kPa) was applied. Both backwashing duration and flux exhibited similar influence on cake fouling removal for a given volume of permeate produced.

  15. CONCENTRATION AND DETECTION OF CRYPTOSPORIDIUM OOCYSTS IN SURFACE WATER SAMPLES BY METHOD 1622 USING ULTRAFILTRATION AND CAPSULE FILTRATION

    EPA Science Inventory

    The protozoan parasite cryptosporidium parvum is known to occur widely in both source and drinking water and has caused waterborne outbreaks of gastroenteritis. To improve monitoring, the USEPA developed Method 1622 for isolation and detection of cryptosporidim oocysts in water. ...

  16. Concentration and Detection of Cryptosporidium Oocysts in Surface Water Samples by Method 1622 Using Ultrafiltration and Capsule Filtration

    USGS Publications Warehouse

    Simmons, O. D.; Sobsey, M.D.; Heaney, C.D.; Schaefer, F. W.; Francy, D.S.

    2001-01-01

    The protozoan parasite Cryptosporidium parvum is known to occur widely in both source and drinking water and has caused waterborne outbreaks of gastroenteritis. To improve monitoring, the U.S. Environmental Protection Agency developed method 1622 for isolation and detection of Cryptosporidium oocysts in water. Method 1622 is performance based and involves filtration, concentration, immunomagnetic separation, fluorescent-antibody staining and 4???,6-diamidino-2-phenylindole (DAPI) counterstaining, and microscopic evaluation. The capsule filter system currently recommended for method 1622 was compared to a hollow-fiber ultrafilter system for primary concentration of C. parvum oocysts in seeded reagent water and untreated surface waters. Samples were otherwise processed according to method 1622. Rates of C. parvum oocyst recovery from seeded 10-liter volumes of reagent water in precision and recovery experiments with filter pairs were 42% (standard deviation [SD], 24%) and 46% (SD, 18%) for hollow-fiber ultrafilters and capsule filters, respectively. Mean oocyst recovery rates in experiments testing both filters on seeded surface water samples were 42% (SD, 27%) and 15% (SD, 12%) for hollow-fiber ultrafilters and capsule filters, respectively. Although C. parvum oocysts were recovered from surface waters by using the approved filter of method 1622, the recovery rates were significantly lower and more variable than those from reagent grade water. In contrast, the disposable hollow-fiber ultrafilter system was compatible with subsequent method 1622 processing steps, and it recovered C. parvum oocysts from seeded surface waters with significantly greater efficiency and reliability than the filter suggested for use in the version of method 1622 tested.

  17. Evaluation of Radial Flow Fluidized Filter (R3F) Followed by Microfiltration and Ultrafiltration Systems in Calimesa, California

    EPA Science Inventory

    U.S. EPA coordinated a field study with South Mesa Water Utility to look for treatment alternatives for California State Project Water in the small community of Calimesa, California. EPA evaluated the performance of a system comprised of Radial Flow Fluidized Filtration (R3f) fo...

  18. Ultralow Oil-Fouling Heterogeneous Poly(ether sulfone) Ultrafiltration Membrane via Blending with Novel Amphiphilic Fluorinated Gradient Copolymers.

    PubMed

    Zhang, Guangfa; Jiang, Jingxian; Zhang, Qinghua; Gao, Fan; Zhan, Xiaoli; Chen, Fengqiu

    2016-02-01

    A novel amphiphilic fluorinated gradient copolymer was prepared by semibatch reversible addition-fragmentation chain transfer (RAFT) method using poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate (TFOA) as monomers. The resultant amphiphilic copolymers were then incorporated into the poly(ether sulfone) (PES) to fabricate PES blend membranes via the non-solvent-induced phase separation method (NIPS). During the phase inversion process, both hydrophilic (PEGMA) and low surface energy (TFOA) segments significantly enriched on the membrane surface by surface segregation to form an amphiphilic surface, which was demonstrated by surface wetting properties and X-ray photoelectron spectroscopy (XPS) measurements. According to the filtration experiments of oil-in-water emulsion, the heterogeneous membranes exhibited superior oil-fouling resistant properties, that is, low flux decay (as low as 15.4%) and high flux recovery (almost 100%), compared to the pure PES membrane. The synergistic effect of fouling-resistant and fouling-release mechanisms was found to be responsible for the excellent antifouling capacities. The findings of this study offer a facile and robust strategy for fabricating ultralow oil-fouling membranes that might be used for effective oil/water separation.

  19. Transparent exopolymer particles (TEP) removal efficiency by a combination of coagulation and ultrafiltration to minimize SWRO membrane fouling.

    PubMed

    Li, Sheng; Lee, Shang-Tse; Sinha, Shahnawaz; Leiknes, TorOve; Amy, Gary L; Ghaffour, Noreddine

    2016-10-01

    This study investigated the impact of coagulation on the transformation between colloidal and particulate transparent exopolymer particles (TEP) in seawater; and the effectiveness of a combined pretreatment consisting of coagulation and UF on minimizing TEP fouling of seawater reverse osmosis (SWRO) membranes. Coagulation with ferric chloride at pH 5 substantially transformed colloidal TEP (0.1-0.4) into particulate TEP (>0.4) leading to a better membrane fouling control. Both 50 and 100 kDa molecular weight cut-off (MWCO) UF membranes removed most of particulate and colloidal TEP without the assistance of coagulation, but coagulation is still necessary for better UF fouling control. The improvement of combined SWRO pretreatment with coagulation and 50 kDa UF membranes was not that much significant compared to UF pretreatment with 50 KDa alone. Therefore, the minimal coagulant dosage for seawater containing TEP should be based on the UF fouling control requirements rather than removal efficiency.

  20. AUTOMATED DEAD-END ULTRAFILTRATION FOR ENHANCED SURVEILLANCE OF LEGIONELLA 2 PNEUMOPHILA AND LEGIONELLA SPP. IN COOLING TOWER WATERS

    SciTech Connect

    Brigmon, R.; Leskinen, S.; Kearns, E.; Jones, W.; Miller, R.; Betivas, C.; Kingsley, M.; Lim, D.

    2011-10-10

    Detection of Legionella pneumophila in cooling towers and domestic hot water systems involves concentration by centrifugation or membrane filtration prior to inoculation onto growth media or analysis using techniques such as PCR or immunoassays. The Portable Multi-use Automated Concentration System (PMACS) was designed for concentrating microorganisms from large volumes of water in the field and was assessed for enhancing surveillance of L. pneumophila at the Savannah River Site, SC. PMACS samples (100 L; n = 28) were collected from six towers between August 2010 and April 2011 with grab samples (500 ml; n = 56) being collected before and after each PMACS sample. All samples were analyzed for the presence of L. pneumophila by direct fluorescence immunoassay (DFA) using FITC-labeled monoclonal antibodies targeting serogroups 1, 2, 4 and 6. QPCR was utilized for detection of Legionella spp. in the same samples. Counts of L. pneumophila from DFA and of Legionella spp. from qPCR were normalized to cells/L tower water. Concentrations were similar between grab and PMACS samples collected throughout the study by DFA analysis (P = 0.4461; repeated measures ANOVA). The same trend was observed with qPCR. However, PMACS concentration proved advantageous over membrane filtration by providing larger volume, more representative samples of the cooling tower environment, which led to reduced variability among sampling events and increasing the probability of detection of low level targets. These data highlight the utility of the PMACS for enhanced surveillance of L. pneumophila by providing improved sampling of the cooling tower environment.

  1. Transparent exopolymer particles (TEP) removal efficiency by a combination of coagulation and ultrafiltration to minimize SWRO membrane fouling.

    PubMed

    Li, Sheng; Lee, Shang-Tse; Sinha, Shahnawaz; Leiknes, TorOve; Amy, Gary L; Ghaffour, Noreddine

    2016-10-01

    This study investigated the impact of coagulation on the transformation between colloidal and particulate transparent exopolymer particles (TEP) in seawater; and the effectiveness of a combined pretreatment consisting of coagulation and UF on minimizing TEP fouling of seawater reverse osmosis (SWRO) membranes. Coagulation with ferric chloride at pH 5 substantially transformed colloidal TEP (0.1-0.4) into particulate TEP (>0.4) leading to a better membrane fouling control. Both 50 and 100 kDa molecular weight cut-off (MWCO) UF membranes removed most of particulate and colloidal TEP without the assistance of coagulation, but coagulation is still necessary for better UF fouling control. The improvement of combined SWRO pretreatment with coagulation and 50 kDa UF membranes was not that much significant compared to UF pretreatment with 50 KDa alone. Therefore, the minimal coagulant dosage for seawater containing TEP should be based on the UF fouling control requirements rather than removal efficiency. PMID:27403871

  2. Removal of Microbial Contaminants in Drinking Water: Siemens Corporation Memcor® S10V Ultrafiltration Module

    EPA Science Inventory

    The Siemens Memcor S10V UF module was tested for removal of endospores of the bacteria Bacillus atrophaeus and the MS2 coliphage virus according to the requirements of the EPA Long-Term 2 Enchanced Surface Water Treatment Rule (LT2ESWTR). B. atrophaeus served as a surrogate for ...

  3. Removal of Microbial Contaminants in Drinking Water: Siemens Corporation Memcor® L10V Ultrafiltration Module

    EPA Science Inventory

    The Siemens Memcor L10V UF module was tested for removal of Cryptosporidium parvum oocyste, endospores of the bacteria Bacillus atrophaeus, and the MS2 coliphage virus according to the requirements of the EPA Long-Term 2 Enchanced Surface Water Treatment Rule (LT2ESWTR). Five m...

  4. Environmental Technology Verification Report; Removal of Microbial Contaminants in Drinking Water Dow Chemical Company - Water Solutions SFD-2880 Ultrafiltration Module

    EPA Science Inventory

    The Dow SFD-2880 UF module was tested for removal of microorganisms using live Cryptosporidium parvum oocysts, endospores of the bacteria Bacillus alrophaeus, and the MS2 coliphage virus according to the product-specific challenge testing requirements of the EPA Long-Term 2 Enhan...

  5. Removal of Microbial Contaminants in Drinking Water: Siemens Corporation Memcor® L20V Ultrafiltration Module

    EPA Science Inventory

    The Siemens Memcor L20V UF module was tested for removal of endospores of the bacteria Bacillus atrophaeus and the MS2 coliphage virus according to the requirements of the EPA Long-Term 2 Enchanced Surface Water Treatment Rule (LT2ESWTR). B. atrophaeus served as a surrogate for ...

  6. New Method Using a Positively Charged Microporous Filter and Ultrafiltration for Concentration of Viruses from Tap Water ▿

    PubMed Central

    Ikner, Luisa A.; Soto-Beltran, Marcela; Bright, Kelly R.

    2011-01-01

    The methods used to concentrate enteric viruses from water have remained largely unchanged for nearly 30 years, with the most common technique being the use of 1MDS Virozorb filters followed by organic flocculation for secondary concentration. Recently, a few studies have investigated alternatives; however, many of these methods are impractical for use in the field or share some of the limitations of this traditional method. In the present study, the NanoCeram virus sampler, an electropositive pleated microporous filter composed of microglass filaments coated with nanoalumina fibers, was evaluated. Test viruses were first concentrated by passage of 20 liters of seeded water through the filter (average filter retention efficiency was ≥99.8%), and then the viruses were recovered using various salt-based or proteinaceous eluting solutions. A 1.0% sodium polyphosphate solution with 0.05 M glycine was determined to be the most effective. The recovered viruses were then further concentrated using Centricon Plus-70 centrifugal ultrafilters to a final volume of 3.3 (±0.3 [standard deviation]) ml; this volume compares quite favorably to that of previously described methods, such as organic flocculation (∼15 to 40 ml). The overall virus recovery efficiencies were 66% for poliovirus 1, 83% for echovirus 1, 77% for coxsackievirus B5, 14% for adenovirus 2, and 56% for MS2 coliphage. In addition, this method appears to be compatible with both cell culture and PCR assays. This new approach for the recovery of viruses from water is therefore a viable alternative to currently used methods when small volumes of final concentrate are an advantage. PMID:21441329

  7. Effect of interactions between Co(2+) and surface goethite layer on the performance of α-FeOOH coated hollow fiber ceramic ultrafiltration membranes.

    PubMed

    Zhu, Zhiwen; Zhu, Li; Li, Jianrong; Tang, Jianfeng; Li, Gang; Hsieh, Yi-Kong; Wang, TsingHai; Wang, Chu-Fang

    2016-03-15

    The consideration of water energy nexus inspires the environmental engineering community to pursue a more sustainable strategy in the wastewater treatment. One potential response would be to enhance the performance of the low-pressure driven filtration system. To reach this objective, it is essential to have a better understanding regarding the surface interaction between the target substance and the surface of membrane. In this study, the hollow fiber ceramic membranes were coated with a goethite layer in order to enhance the Co(2+) rejection. Experimental results indicate that higher Co(2+) rejections are always accompanied with the significant reduction in the permeability. Based on the consideration of electroviscous effect, the surface interactions including the induced changes in viscosity, pore radius and Donnan effect in the goethite layer are likely responsible for the pH dependent behaviors in the rejection and permeability. These results could be valuable references to develop the filtration system with high rejection along with acceptable degree of permeability in the future.

  8. Variation in aluminum, iron, and particle concentrations in oxic ground-water samples collected by use of tangential-flow ultrafiltration with low-flow sampling

    USGS Publications Warehouse

    Szabo, Z.; Oden, J.H.; Gibs, J.; Rice, D.E.; Ding, Y.; ,

    2001-01-01

    Particulates that move with ground water and those that are artificially mobilized during well purging could be incorporated into water samples during collection and could cause trace-element concentrations to vary in unfiltered samples, and possibly in filtered samples (typically 0.45-um (micron) pore size) as well, depending on the particle-size fractions present. Therefore, measured concentrations may not be representative of those in the aquifer. Ground water may contain particles of various sizes and shapes that are broadly classified as colloids, which do not settle from water, and particulates, which do. In order to investigate variations in trace-element concentrations in ground-water samples as a function of particle concentrations and particle-size fractions, the U.S. Geological Survey, in cooperation with the U.S. Air Force, collected samples from five wells completed in the unconfined, oxic Kirkwood-Cohansey aquifer system of the New Jersey Coastal Plain. Samples were collected by purging with a portable pump at low flow (0.2-0.5 liters per minute and minimal drawdown, ideally less than 0.5 foot). Unfiltered samples were collected in the following sequence: (1) within the first few minutes of pumping, (2) after initial turbidity declined and about one to two casing volumes of water had been purged, and (3) after turbidity values had stabilized at less than 1 to 5 Nephelometric Turbidity Units. Filtered samples were split concurrently through (1) a 0.45-um pore size capsule filter, (2) a 0.45-um pore size capsule filter and a 0.0029-um pore size tangential-flow filter in sequence, and (3), in selected cases, a 0.45-um and a 0.05-um pore size capsule filter in sequence. Filtered samples were collected concurrently with the unfiltered sample that was collected when turbidity values stabilized. Quality-assurance samples consisted of sequential duplicates (about 25 percent) and equipment blanks. Concentrations of particles were determined by light scattering. Variations in concentrations aluminum and iron (1 -74 and 1-199 ug/L (micrograms per liter), respectively), common indicators of the presence of particulate-borne trace elements, were greatest in sample sets from individual wells with the greatest variations in turbidity and particle concentration. Differences in trace-element concentrations in sequentially collected unfiltered samples with variable turbidity were 5 to 10 times as great as those in concurrently collected samples that were passed through various filters. These results indicate that turbidity must be both reduced and stabilized even when low-flow sample-collection techniques are used in order to obtain water samples that do not contain considerable particulate artifacts. Currently (2001) available techniques need to be refined to ensure that the measured trace-element concentrations are representative of those that are mobile in the aquifer water.

  9. Variation in aluminum, iron, and particle concentrations in oxic groundwater samples collected by use of tangential-flow ultrafiltration with low-flow sampling

    NASA Astrophysics Data System (ADS)

    Szabo, Zoltan; Oden, Jeannette H.; Gibs, Jacob; Rice, Donald E.; Ding, Yuan

    2002-02-01

    Particulates that move with ground water and those that are artificially mobilized during well purging could be incorporated into water samples during collection and could cause trace-element concentrations to vary in unfiltered samples, and possibly in filtered samples (typically 0.45-um (micron) pore size) as well, depending on the particle-size fractions present. Therefore, measured concentrations may not be representative of those in the aquifer. Ground water may contain particles of various sizes and shapes that are broadly classified as colloids, which do not settle from water, and particulates, which do. In order to investigate variations in trace-element concentrations in ground-water samples as a function of particle concentrations and particle-size fractions, the U.S. Geological Survey, in cooperation with the U.S. Air Force, collected samples from five wells completed in the unconfined, oxic Kirkwood-Cohansey aquifer system of the New Jersey Coastal Plain. Samples were collected by purging with a portable pump at low flow (0.2-0.5 liters per minute and minimal drawdown, ideally less than 0.5 foot). Unfiltered samples were collected in the following sequence: (1) within the first few minutes of pumping, (2) after initial turbidity declined and about one to two casing volumes of water had been purged, and (3) after turbidity values had stabilized at less than 1 to 5 Nephelometric Turbidity Units. Filtered samples were split concurrently through (1) a 0.45-um pore size capsule filter, (2) a 0.45-um pore size capsule filter and a 0.0029-um pore size tangential-flow filter in sequence, and (3), in selected cases, a 0.45-um and a 0.05-um pore size capsule filter in sequence. Filtered samples were collected concurrently with the unfiltered sample that was collected when turbidity values stabilized. Quality-assurance samples consisted of sequential duplicates (about 25 percent) and equipment blanks. Concentrations of particles were determined by light scattering.

  10. The use of ozonation and catalytic ozonation combined with ultrafiltration for the control of natural organic matter (NOM) and disinfection by-products (DBPs) in drinking water

    NASA Astrophysics Data System (ADS)

    Karnik, Bhavana Sushilkumar

    Commercially available titania membranes, with a molecular weight cut-off of 15, 5, 1 kD were used in a ozonation/membrane system that was fed with water from Lake Lansing. The effects of ozonation on permeate flux recovery and membrane fouling was investigated. In addition the effects of ozonation/membrane filtration hybrid process on the removal of the natural organic matter (NOM) and the formation of disinfection by-products (DBPS) were monitored. The commercial membrane (CeRAM Inside, Tami North America, St. Laurent, Quebec, Canada) was coated with iron oxide nanoparticles (4--6 nm in diameter) using a layer-by-layer technique and sintered in air for 30 minutes. Surface characterization was carried out using electron microscopy techniques and atomic force microscopy, to study the changes in structure and surface morphology of the membranes. The removal and survival of bacteria in the process was also evaluated using fluorescence microscopy and microbial assays. Finally the surface catalytic reaction was investigated to propose the mechanism responsible for the improved performance of the hybrid process. The permeate flux through a titania coated ceramic membrane was significantly affected by ozonation. A minimum threshold ozone concentration (2.5 g/m 3) could achieve complete recovery of permeate flux after fouling. Ozonation/filtration decreased the concentration of chlorinated disinfection by-products up to 80%. With catalyst coated membranes, the concentration of dissolved organic carbon was reduced by >85% and the concentrations of disinfection by-products decreased by up to 90%. Furthermore with the coated membrane, the concentrations of ozonation by-products in the permeate were reduced by >50% as compared to that obtained with the uncoated membranes, thus reducing the risk of potential regrowth of bacteria in the distribution system. Application of the hybrid process lead to greater than 7 log removal of bacteria. Surface characterization showed that optimum water quality was achieved at 40 layers, which corresponds to a surface coating morphology consisting of a uniform, coarse-grained structure with open, nano-sized interconnected pores. A mechanism is proposed showing strong surface catalytic effect leading to improved performance of the ozone-membrane filtration hybrid process.

  11. Effect of interactions between Co(2+) and surface goethite layer on the performance of α-FeOOH coated hollow fiber ceramic ultrafiltration membranes.

    PubMed

    Zhu, Zhiwen; Zhu, Li; Li, Jianrong; Tang, Jianfeng; Li, Gang; Hsieh, Yi-Kong; Wang, TsingHai; Wang, Chu-Fang

    2016-03-15

    The consideration of water energy nexus inspires the environmental engineering community to pursue a more sustainable strategy in the wastewater treatment. One potential response would be to enhance the performance of the low-pressure driven filtration system. To reach this objective, it is essential to have a better understanding regarding the surface interaction between the target substance and the surface of membrane. In this study, the hollow fiber ceramic membranes were coated with a goethite layer in order to enhance the Co(2+) rejection. Experimental results indicate that higher Co(2+) rejections are always accompanied with the significant reduction in the permeability. Based on the consideration of electroviscous effect, the surface interactions including the induced changes in viscosity, pore radius and Donnan effect in the goethite layer are likely responsible for the pH dependent behaviors in the rejection and permeability. These results could be valuable references to develop the filtration system with high rejection along with acceptable degree of permeability in the future. PMID:26704473

  12. DENDRIMER ENHANCED ULTRAFILTRATION. 1. RECOVERY OF CU(II) FROM AQUEOUS SOLUTIONS USING PAMAM DENDRIMERS WITH ETHYLENE DIAMINE CORE AND TERMINAL NH2 GROUPS (R829626)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  13. PROBING REACTIVITY OF DISSOLVED ORGANIC MATTER FOR DISINFECTION BY-PRODUCT FORMATION USING XAD-8 RESIN ADSORPTION AND ULTRAFILTRATION FRACTIONATION. (R828045)

    EPA Science Inventory

    The disinfection by-product (DBP) reactivity (yield and speciation upon reaction with chlorine) of dissolved organic matter (DOM) isolated from two surface waters was investigated. The source waters, each having significantly different specific ultraviolet absorbance (SUVA

  14. ETV STATEMENT - PHYSICAL REMOVAL OF CRYPTOSPORIDIUM OOCYSTS AND GIARDIA CYSTS IN DRINKING WATER - ZENON ZEEWEED ZW500 ULTRAFILTRATION MEMBRANE SYSTEM AT PITTSBURGH, PA

    EPA Science Inventory

    Verification testing of the ZENON Environmental Inc. ZeeWeed ZW500 UF Drinking Water System was conducted from 2/6-3/7/99. The treatment system underwent Giardia and Cryptosporidium removal challenge testing on 3/2/99 and demonstrated a 5.3 log10 removal of Giardia cysts and a 6...

  15. Optimization of Co2+ ions removal from water solutions via polymer enhanced ultrafiltration with application of PVA and sulfonated PVA as complexing agents.

    PubMed

    Uzal, Niğmet; Jaworska, Agnieszka; Miśkiewicz, Agnieszka; Zakrzewska-Trznadel, Grażyna; Cojocaru, Corneliu

    2011-10-15

    The paper presents the results of the studies of UF-complexation process applied for the removal of Co(2+) ions from water solutions. As binding agents for cobalt ions, the PVA polymer (M(w)=10,000) and its sulfonated form, synthesized in the laboratory, have been used. The method of experimental design and response surface methodology have been employed to find out the optimal conditions for the complexation process and to evaluate the interaction between the input variables, i.e., initial cobalt concentration, pH and amount of the polymer used, expressed as a polymer/Co(2+) ratio r. The data collected by the designed experiments showed that sulfonation of polymer has improved significantly the binding ability of PVA. The optimal conditions of cobalt ions complexation established by response surface model for non-sulfonated PVA polymer have been found to be as follows: the initial concentration of Co(2+)=5.70 mg L(-1), the ratio between polymer and metal ions, r=8.58 and pH=5.93. The removal efficiency of Co(2+) in these conditions was 31.81%. For sulfonated PVA polymer, the optimal conditions determined are as follows: initial concentration of [Co(2+)](0)=10 mg L(-1), r=1.2 and pH=6.5. For these conditions, a removal efficiency of 99.98% has been determined. The experiments showed that Co(2+) removal ability of sulfonated PVA was much higher than its non-sulfonated precursor. Although the polymer concentrations used in the tests with sulfonated PVA were approximately ten times lower than the non-sulfonated one, the removal efficiency of cobalt ions was significantly higher.

  16. EFFICIENT RECOVERY OF ENTEROCOCCI FROM MARINE AND FRESH WATER BEACHES BY A 30,000 MOLECULAR WEIGHT CUTOFF HOLLOW FIBER ULTRAFILTER

    EPA Science Inventory

    Ultrafiltration systems have been used to concentrate pathogens from various types of fresh water samples. However, less work has been done with marine waters for the concentration of pathogens or indicator bacteria. An ultrafiltration approach to concentrate indicator bacteria...

  17. 76 FR 32200 - Notice of a Project Waiver of Section 1605 (Buy American Requirement) of the American Recovery...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-03

    ... hollow fiber ultrafiltration membrane cassettes, ZeeWeed 500D, which are the effluent filtration...) upgrade project. The ZeeWeed 500D immersed ultrafiltration membrane cassettes are manufactured outside of...Weed 500D immersed hollow fiber ultrafiltration membrane cassettes manufactured in Hungary by...

  18. Removal of Microbial Contaminants in Drinking Water: Koch Membrane Systems, Inc. Targa® 10-48-35-PMC™ Ultrafiltration Membrane, as Used in the Village Marine Tec. Expeditionary Unit Water Purifier

    EPA Science Inventory

    The Koch Membrane Systems Targa 10-48-35-PMC UF membrane module is used for the first treatment step in the US Navy Office of Naval Research’s Expeditionary Unit Water Purifier (EUWP). Two used UF cartridges from the EUWP were tested for removal of endospores of the bacteria Bac...

  19. Inactivating effects of lignin-derived compounds released during lignocellulosic biomass pretreatment on the endo-glucanase catalyzed hydrolysis of carboxymethylcellulose: A study in continuous stirred ultrafiltration-membrane reactor.

    PubMed

    Cantarella, Maria; Mucciante, Claudia; Cantarella, Laura

    2014-03-01

    This study focusses on the reversible/irreversible damage that selected phenolic compounds, released during steam-explosion pretreatment, mandatory for cellulose accessibility, causes on both stability and activity of a commercial cellulase (half-life=173h) during carboxymethyl-cellulose hydrolysis. Long-term experiments performed in continuous stirred UF-membrane bioreactors, operating at steady-state regime, in controlled operational conditions, allowed evaluating the inactivation-constant in the phenol presence (kd1) and after its removal (kd2) from the reactor feed. p-Hydroxybenzoic acid (1 and 2g L(-1)) are the extreme limits in the inactivating effect with enzyme half-lives 99.02 and 14.15h, respectively. The inactivation reversibility was assessed for vanillic acid, p-hydroxybenzoic acid, syringaldehyde, p-coumaric acid, being kd1>kd2. p-Hydroxybenzaldehyde and protocatechuic acid irreversibly affected cellulase stability increasing its inactivation with kd2>kd1. p-Hydroxybenzaldehyde, 1g L(-1), syringaldehyde, and vanillin, at 2gL(-1), had similar kd1÷kd2. PMID:24486937

  20. Inactivating effects of lignin-derived compounds released during lignocellulosic biomass pretreatment on the endo-glucanase catalyzed hydrolysis of carboxymethylcellulose: A study in continuous stirred ultrafiltration-membrane reactor.

    PubMed

    Cantarella, Maria; Mucciante, Claudia; Cantarella, Laura

    2014-03-01

    This study focusses on the reversible/irreversible damage that selected phenolic compounds, released during steam-explosion pretreatment, mandatory for cellulose accessibility, causes on both stability and activity of a commercial cellulase (half-life=173h) during carboxymethyl-cellulose hydrolysis. Long-term experiments performed in continuous stirred UF-membrane bioreactors, operating at steady-state regime, in controlled operational conditions, allowed evaluating the inactivation-constant in the phenol presence (kd1) and after its removal (kd2) from the reactor feed. p-Hydroxybenzoic acid (1 and 2g L(-1)) are the extreme limits in the inactivating effect with enzyme half-lives 99.02 and 14.15h, respectively. The inactivation reversibility was assessed for vanillic acid, p-hydroxybenzoic acid, syringaldehyde, p-coumaric acid, being kd1>kd2. p-Hydroxybenzaldehyde and protocatechuic acid irreversibly affected cellulase stability increasing its inactivation with kd2>kd1. p-Hydroxybenzaldehyde, 1g L(-1), syringaldehyde, and vanillin, at 2gL(-1), had similar kd1÷kd2.

  1. ETV REPORT - PHYSICAL REMOVAL OF MICROBIOLOGICAL, PARTICULATE AND ORGANIC CONTAMINANTS IN DRINKING WATER - ZENON ENHANCED COAGULATION ZEEWEED ULTRAFILTRATION MEMBRANE SYSTEM AT ESCONDIDO, CALIFORNIA: NSF00/02/EPADW395

    EPA Science Inventory

    NSF Int in cooperation with EPA operates the Package Drinking Water Treatment Systems program, one of 12 technology areas under ETV. The performance of an enhanced coagulation membrane filtration systems used in package drinking water treatment system applications was recently ev...

  2. Research and development to overcome fouling of membranes. Final report

    SciTech Connect

    Narang, S.C.; Sharma, S.K.; Hum, G.; Ventura, S.C.; Roberts, D.L.; Gottschlich, D.; Ahner, N.

    1998-11-01

    To overcome fouling of membranes, SRI International is developing a unique piezoelectric backing for ultrafiltration membranes. This backing is capable of producing local turbulence next to the membrane to minimize concentration polarization and the rate of buildup of solutes and particulate matter on the membrane surface. We have studied piezoelectrically assisted ultrafiltration in more detail, with the objective to apply this process to industrial ultrafiltrations. We conducted several ultrafiltration experiments on flat sheet membranes with model dextran solutions and with electrocoat paint to study flux enhancement as a function of parameters such as feed flow rate, feed pressure, as well as the piezodriver-membrane system.

  3. Replacement of chemical intensive water treatment processes with energy saving membrane. Final report

    SciTech Connect

    Mickley, M.C.; Goering, S.W.

    1983-11-01

    The project investigated the use of charged ultrafiltration membranes to treat hard water. More specifically, the work was undertaken to (1) make charged ultrafiltration membranes to demonstrate the technical feasibility of the chemical grafting approach; (2) evaluate the market potential for charged ultrafiltration membranes; and (3) evaluate the cost and energy savings for using charged ultrafiltration as compared to lime-based clarification and other treatment methods. The results suggest that chemical grafting is a relatively simple, reproducible and low-cost way to modify existing substrate materials to give them enhanced transport performance. Process studies lead to the identification of good market potential for membrane processes using charged ultrafiltration membranes. Capital and operating costs relative to lime-based clarification are favorable for low- and medium-sized treatment plants. Finally, substantial energy savings are apparent as compared to lime-based precipitation systems which incur substantial energy consumption in the lime production and transportation steps.

  4. Evolution of phospholipid contents during the production of quark cheese from buttermilk.

    PubMed

    Ferreiro, T; Martínez, S; Gayoso, L; Rodríguez-Otero, J L

    2016-06-01

    We report the evolution of phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylserine (PS), and sphingomyelin (SM) contents during the production of quark cheese from buttermilk by successive ultrafiltration concentration, enrichment with cream, concurrent homogenization and pasteurization, fermentative coagulation, and separation of quark from whey by further ultrafiltration. Buttermilk is richer than milk itself in phospholipids that afford desirable functional and technological properties, and is widely used in dairy products. To investigate how phospholipid content is affected by end-product production processes such as ultrafiltration, homogenization, pasteurization or coagulation, we measured the phospholipids at several stages of each of 5 industrial-scale quark cheese production runs. In each run, 10,000L of buttermilk was concentrated to half volume by ultrafiltration, enriched with cream, homogenized, pasteurized, inoculated with lactic acid bacteria, incubated to coagulation, and once more concentrated to half volume by ultrafiltration. Phospholipid contents were determined by HPLC with evaporative light scattering detection in the starting buttermilk, concentrated buttermilk, ultrafiltrate, cream-enriched concentrated buttermilk (both before and after concurrent homogenization and pasteurization), coagulate, and quark, and also in the rinsings obtained when the ultrafiltration equipment was washed following initial concentration. The average phospholipid content of buttermilk was approximately 5 times that of milk, and the phospholipid content of buttermilk fat 26 to 29 times that of milk fat. Although phospholipids did not cross ultrafiltration membranes, significant losses occurred during ultrafiltration (due to retention on the membranes) and during the homogenization and pasteurization process. During coagulation, however, phospholipid content rose, presumably as a consequence of the proliferation of the

  5. Evolution of phospholipid contents during the production of quark cheese from buttermilk.

    PubMed

    Ferreiro, T; Martínez, S; Gayoso, L; Rodríguez-Otero, J L

    2016-06-01

    We report the evolution of phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylserine (PS), and sphingomyelin (SM) contents during the production of quark cheese from buttermilk by successive ultrafiltration concentration, enrichment with cream, concurrent homogenization and pasteurization, fermentative coagulation, and separation of quark from whey by further ultrafiltration. Buttermilk is richer than milk itself in phospholipids that afford desirable functional and technological properties, and is widely used in dairy products. To investigate how phospholipid content is affected by end-product production processes such as ultrafiltration, homogenization, pasteurization or coagulation, we measured the phospholipids at several stages of each of 5 industrial-scale quark cheese production runs. In each run, 10,000L of buttermilk was concentrated to half volume by ultrafiltration, enriched with cream, homogenized, pasteurized, inoculated with lactic acid bacteria, incubated to coagulation, and once more concentrated to half volume by ultrafiltration. Phospholipid contents were determined by HPLC with evaporative light scattering detection in the starting buttermilk, concentrated buttermilk, ultrafiltrate, cream-enriched concentrated buttermilk (both before and after concurrent homogenization and pasteurization), coagulate, and quark, and also in the rinsings obtained when the ultrafiltration equipment was washed following initial concentration. The average phospholipid content of buttermilk was approximately 5 times that of milk, and the phospholipid content of buttermilk fat 26 to 29 times that of milk fat. Although phospholipids did not cross ultrafiltration membranes, significant losses occurred during ultrafiltration (due to retention on the membranes) and during the homogenization and pasteurization process. During coagulation, however, phospholipid content rose, presumably as a consequence of the proliferation of the

  6. Membrane permeation employed for radioactive wastes treatment

    SciTech Connect

    Chmielewski, A.G.; Harasimowicz, M.; Zakrzewska-Trznadel, G.

    1996-12-31

    In the paper certain aspects of development process aiming at reducing the radioactivity of liquid low-level waste streams (LLLW) are presented. The influence of gamma and electron radiation on ultrafiltration membranes has been studied and changes of their transport properties have been determined at different doses. Membrane processes: ultrafiltration (UF), seeded ultrafiltration (SUF), low-pressure reverse osmosis (LPRO) and membrane distillation (MD) have been examined. The UF/RO pilot plant for purification/concentration of low-level liquid waste is described. 4 refs., 2 figs.

  7. Design and evaluation of solid lipid nanoparticles modified with peptide ligand for oral delivery of protein drugs.

    PubMed

    Fan, Tingting; Chen, Chunhui; Guo, Han; Xu, Juan; Zhang, Jian; Zhu, Xi; Yang, Yang; Zhou, Zhou; Li, Lian; Huang, Yuan

    2014-10-01

    Designing feasible and effective peptide ligand modified solid lipid nanoparticles (SLNs) to improve oral bioavailability of protein drugs and evaluating the influence of mucus remains important. In the present work, two kinds of peptide ligand modified SLNs loaded with salmon calcitonin (sCT), namely, sCT CSK-SLNs and sCT IRQ-SLNs, were prepared by coupling the peptide ligand CSKSSDYQC (CSK) which was reported to show affinity with goblet cells, or IRQRRRR (IRQ), a cell penetrating peptide, to polyoxyethylene (40) stearate (SA-PEG2000). Compared with unmodified SLNs, CSK or IRQ modified SLNs with better drug protection ability could facilitate the internalization of drug on Caco-2/HT29-MTX co-cultured cells and permeation in excised rat duodenum mucosa. The internalization mechanism of two kinds of peptide ligand modified SLNs was mainly active transport via both clathrin- and caveolae-dependent endocytosis. Although mucus was an impediment to the transport of SLNs, the peptide ligand modified SLNs still showed improved drug absorption. The absolute bioavailability of sCT CSK-SLNs (12.41 ± 3.65%) and sCT IRQ-SLNs (10.05 ± 5.10%) raised to 2.45-fold and 1.98-fold compared with unmodified SLNs (5.07 ± 0.54%), implying the feasibility and effectiveness of CSK and IRQ peptide modification for the enhancement of the oral bioavailability of protein drugs. In summary, the nanoparticles modified with CSK or IRQ peptide ligand could be the potential carriers for the transport of protein drugs across intestinal barriers.

  8. Simplified process for preparation of schizophyllan solutions for biomaterial applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Schizophyllan is a biopolymer commercially produced for pharmaceutical and cosmetics uses. However, schizophyllan also has potential biomaterial applications. Schizophyllan is conventionally produced from glucose and recovered by diafiltration and ultrafiltration to produce a highly purified product...

  9. EMERGING TECHNOLOGY BULLETIN: NEW JERSEY INSTITUTE OF TECHNOLOGY - GHEA ASSOCIATES PROCESS

    EPA Science Inventory

    The GHEA Associates process applies surfactants and additives to soil washing and wastewater treatment to make organic and metal contaminants soluble (figure 1). The process components include a 25-gal extractor, solid liquid separation, rinse, mixer-settler, and ultrafiltration ...

  10. DEMONSTRATION BULLETIN: ZENOGEM™ WASTEWATER TREATMENT PROCESS - ZENON ENVIRONMENTAL SYSTEMS

    EPA Science Inventory

    Zenon Environmental Systems (Zenon) has developed the ZenoGem™ process to remove organic compounds from wastewater by integrating biological treatment and membrane-based ultrafiltration. This innovative system combines biological treatment to remove biodegradable organic compou...

  11. SITE TECHNOLOGY CAPSULE: ZENOGEM™ WASTEWATER TREATMENT PROCESS

    EPA Science Inventory

    Zenon Environmental System's ZenoGem™ Wastewater Treatment Process treats aqueous media contaminated with volatile/semi-volatile organic compounds. This technology combines aerobic biological treatment to remove biodegradable organic compounds with ultrafiltration to separate res...

  12. WATER QUALITY

    EPA Science Inventory

    This manual was develped to provide an overview of microfiltration and ultrafiltration technology for operators, administrators, engineers, scientists, educators, and anyone seeking an introduction to these processes. Chapters on theory, water quality, applications, design, equip...

  13. Use of physical processes for treatment of hazardous wastes: Removing oil from water

    SciTech Connect

    Irvin, S.R.

    1984-08-01

    In many U.S. municipal sewerage systems, oils, greases and fats are now being regarded as hazardous wastes. In this study, the authors discuss the need for complete oil removal and progression towards recycle of wastestreams. The use of ultrafiltration is recommended to clean emulsified oil streams, and also the use of absorption media to polish the ultrafiltration product water to a point where recycle is both feasible and within a reasonable economic realm.

  14. [Complex investigation and functional evaluation of patients with a solitary kidney and urolithic disease].

    PubMed

    Boĭko, A I; Hurzhenko, A Iu; Hanzhyĭ, V V; Hubar', A O

    2013-11-01

    Complex examination of patients, having solitary kidney and urolithic disease, was conducted. While comparing the calcium accumulation in glomerular and reabsorbed ultrafiltrate and radio-pharmpreparation in a solitary nonaffected kidney, their step by step increase was noted during follow-up to 1 yr after nephrectomy conduction. The static scintigraphy gives possibility to reveal the calcium content rising in glomerular and reabsorbed ultrafiltrate in each kidney separately.

  15. HIV infection of monocytes inhibits the T-lymphocyte proliferative response to recall antigens, via production of eicosanoids.

    PubMed Central

    Foley, P; Kazazi, F; Biti, R; Sorrell, T C; Cunningham, A L

    1992-01-01

    Human monocytes infected in vitro with human immunodeficiency virus (HIV) soon after adherence to plastic substrate demonstrated a significantly decreased ability to restimulate autologous immune T-lymphocyte proliferation after exposure to soluble (tetanus toxoid) and particulate [herpes simplex virus (HSV)] antigen. Incubation with the cyclo-oxygenase inhibitor, indomethacin (2-5 microM), prevented inhibition of antigen-stimulated lymphocyte proliferation. The inhibitory activity was identified in ultrafiltrates containing the low molecular weight fraction (less than 3000 MW) of supernatants from HIV-infected monocyte cultures. This activity was significantly and markedly reduced in similar ultrafiltrates prepared from indomethacin-treated cultures. Increased concentrations of prostaglandin E2 (PGE2) were detected in ultrafiltrates from HIV-infected monocyte cultures compared with uninfected cultures and cultures preincubated with indomethacin. Ultrafiltrates were inhibitory when added during the presentation of antigen to T lymphocytes but not when removed from monocyte cultures prior to the addition of lymphocytes. In addition, ultrafiltrates inhibited antigen-stimulated lymphocyte proliferation and PHA-induced lymphocyte proliferation to the same extent. These data indicate that cyclo-oxygenase products of arachidonic acid, including PGE2, are produced in excess by HIV-infected monocytes and that PGE2 and perhaps other cyclo-oxygenase products are implicated in the inhibition of antigen-stimulated lymphocyte proliferation via a direct effect on T lymphocytes. PMID:1572689

  16. Electroanalytical applications of screen-printable surfactant-induced sol-gel graphite composites

    DOEpatents

    Guadalupe, Ana R.; Guo, Yizhu

    2001-05-15

    A process for preparing sol-gel graphite composite electrodes is presented. This process preferably uses the surfactant bis(2-ethylhexyl) sulfosuccinate (AOT) and eliminates the need for a cosolvent, an acidic catalyst, a cellulose binder and a thermal curing step from prior art processes. Fabrication of screen-printed electrodes by this process provides a simple approach for electroanalytical applications in aqueous and nonaqueous solvents. Examples of applications for such composite electrodes produced from this process include biochemical sensors such as disposable, single-use glucose sensors and ligand modified composite sensors for metal ion sensitive sensors.

  17. Introduction of multiphosphonate ligand to peptide nucleic acid for metal ion conjugation

    PubMed Central

    Aiba, Yuichiro; Honda, Yuta; Han, Yue; Komiyama, Makoto

    2012-01-01

    Peptide nucleic acid (PNA) is one of the most widely used synthetic DNA analogs. Conjugation of functional molecules to PNA is very effective to further widen its potential applications. For this purpose, here we report the synthesis of several ligand monomers and introduced them to PNA. These ligand-modified PNAs attract cerium ion and are useful for site-selective DNA hydrolysis. It should be noted that these ligands on PNA are also effective even under the conditions of invasion complex. PMID:22772037

  18. Filtration by a novel nanofiber membrane and alumina adsorption to remove copper(II) from groundwater.

    PubMed

    Sang, Yimin; Gu, Qingbao; Sun, Tichang; Li, Fasheng; Liang, Cunzhen

    2008-05-01

    The elevated level of heavy metals in groundwater poses a substantial risk potentially to local resource users and the natural environment. Micellar-enhanced filtration (MEF) and alumina adsorption are considered from the viewpoint of copper(II) removal in groundwater, by taking copper(II) as an example. In MEF, copper(II) cations are collected electrostatically on micelles of sodium dodecyl benzene sulfonate (SDBS) and separated from the mother liquor by filtration using a novel nanofiber membrane prepared from chloridized polyvinyl chloride by high-voltage electrospinning process. After MEF with 10-layer filtration and SDBS concentration of 5 mmol/L, the removal of copper(II) in groundwater is above 70%. However, the final solution contains a large amount of surfactant causing serious second contamination in groundwater. This problem is overcome by alumina adsorption, where negatively charged surfactants are adsorbed on positively charged alumina particles and then recovered by conventional filtration. The hybrid process of MEF and alumina adsorption is successfully applied to removing almost 100% of copper(II) from groundwater. Finally, the characterization of the membrane and filtration mechanism are presented here. PMID:17945414

  19. Filtration by a novel nanofiber membrane and alumina adsorption to remove copper(II) from groundwater.

    PubMed

    Sang, Yimin; Gu, Qingbao; Sun, Tichang; Li, Fasheng; Liang, Cunzhen

    2008-05-01

    The elevated level of heavy metals in groundwater poses a substantial risk potentially to local resource users and the natural environment. Micellar-enhanced filtration (MEF) and alumina adsorption are considered from the viewpoint of copper(II) removal in groundwater, by taking copper(II) as an example. In MEF, copper(II) cations are collected electrostatically on micelles of sodium dodecyl benzene sulfonate (SDBS) and separated from the mother liquor by filtration using a novel nanofiber membrane prepared from chloridized polyvinyl chloride by high-voltage electrospinning process. After MEF with 10-layer filtration and SDBS concentration of 5 mmol/L, the removal of copper(II) in groundwater is above 70%. However, the final solution contains a large amount of surfactant causing serious second contamination in groundwater. This problem is overcome by alumina adsorption, where negatively charged surfactants are adsorbed on positively charged alumina particles and then recovered by conventional filtration. The hybrid process of MEF and alumina adsorption is successfully applied to removing almost 100% of copper(II) from groundwater. Finally, the characterization of the membrane and filtration mechanism are presented here.

  20. Development of a rapid and simple method for detection of protein contaminants in carmine.

    PubMed

    Nakayama, Norihisa; Ohtsu, Yutaka; Maezawa-Kase, Daisuke; Sano, Ken-Ichi

    2015-01-01

    Protein contaminants in carmine can cause dyspnea and anaphylactic reactions in users and consumers of products containing this pigment. The method generally used for detection of proteins in carmine has low reproducibility and is time-consuming. In this study, a rapid, simple, and highly reproducible method was developed for the detection of protein contaminants in carmine. This method incorporates acidic protein denaturation conditions and ultrafiltration. To prevent protein aggregation, sodium dodecyl sulfate containing gel electrophoresis running buffer was used for dispersing the carmine before filtration. An ultrafiltration device was used to separate the protein contaminants from carminic acid in the carmine solution. Two ultrafiltration devices were compared, and a cylindrical device containing a modified polyethersulfone membrane gave the best results. The method had high reproducibility. PMID:25892994