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Sample records for metal immobilization literature

  1. Immobilized metal ion affinity chromatography.

    PubMed

    Yip, T T; Hutchens, T W

    1992-01-01

    Immobilized metal ion affinity chromatography (IMAC) (1,2) is also referred to as metal chelate chromatography, metal ion interaction chromatography, and ligand-exchange chromatography. We view this affinity separation technique as an intermediate between highly specific, high-affinity bioaffinity separation methods, and wider spectrum, low-specificity adsorption methods, such as ion exchange. The IMAC stationary phases are designed to chelate certain metal ions that have selectivity for specific groups (e.g., His residues) in peptides (e.g., 3-7) and on protein surfaces (8-13). The number of stationary phases that can be synthesized for efficient chelation of metal ions is unlimited, but the critical consideration is that there must be enough exposure of the metal ion to interact with the proteins, preferably in a biospecific manner. Several examples are presented in Fig. 1. The challenge to produce new immobilized chelating groups, including protein surface metal-binding domains (14,15) is being explored continuously. Table 1 presents a list of published procedures for the synthesis and use of stationary phases with immobilized chelating groups. This is by no means exhaustive, and is intended only to give an idea of the scope and versatility of IMAC. Fig. 1 Schematic illustration of several types of immobilized metal-chelating groups, including, iminodiacetate (IDA), tris(carboxymethyl) ethylenediamine (TED), and the metal-binding peptides (GHHPH)(n)G (where n = 1,2,3, and 5) (14,15). Table 1 Immobilized Chelating Groups and Metal Ions Used for Immobilized Metal Ion Affinity Chromatography Chelating group Suitable metal ions Reference Commercial source Immodiacetate Transitional1,2 Pharmacia LKB Pierce Sigma Boehringer Mannheim TosoHaas 2-Hydroxy-3[N-(2- pyrtdylmethyl) glycme]propyl Transitional3 Not available ?-Alky1 mtrilo triacetic acid Transitional4 Not available Carboxymethylated asparhc acid Ca(II)13 Not available Tris (carboxy- methyl) ethylene Diamme

  2. Technetium Immobilization Forms Literature Survey

    SciTech Connect

    Westsik, Joseph H.; Cantrell, Kirk J.; Serne, R. Jeffrey; Qafoku, Nikolla

    2014-05-01

    Of the many radionuclides and contaminants in the tank wastes stored at the Hanford site, technetium-99 (99Tc) is one of the most challenging to effectively immobilize in a waste form for ultimate disposal. Within the Hanford Tank Waste Treatment and Immobilization Plant (WTP), the Tc will partition between both the high-level waste (HLW) and low-activity waste (LAW) fractions of the tank waste. The HLW fraction will be converted to a glass waste form in the HLW vitrification facility and the LAW fraction will be converted to another glass waste form in the LAW vitrification facility. In both vitrification facilities, the Tc is incorporated into the glass waste form but a significant fraction of the Tc volatilizes at the high glass-melting temperatures and is captured in the off-gas treatment systems at both facilities. The aqueous off-gas condensate solution containing the volatilized Tc is recycled and is added to the LAW glass melter feed. This recycle process is effective in increasing the loading of Tc in the LAW glass but it also disproportionally increases the sulfur and halides in the LAW melter feed which increases both the amount of LAW glass and either the duration of the LAW vitrification mission or the required supplemental LAW treatment capacity.

  3. Metal Immobilization Influence On Bioavailability And Remediation For Urban Environments

    EPA Science Inventory

    Immobilization of soil contaminants, such as lead, via phosphate amendments to alter the chemical environment of metals into highly insoluble forms is a well established process. The literature has documented numerous examples of highly contaminated Pb sites at shooting ranges, b...

  4. Immobilization of enzymes: a literature survey.

    PubMed

    Brena, Beatriz; González-Pombo, Paula; Batista-Viera, Francisco

    2013-01-01

    The term immobilized enzymes refers to "enzymes physically confined or localized in a certain defined region of space with retention of their catalytic activities, and which can be used repeatedly and continuously." Immobilized enzymes are currently the subject of considerable interest because of their advantages over soluble enzymes. In addition to their use in industrial processes, the immobilization techniques are the basis for making a number of biotechnology products with application in diagnostics, bioaffinity chromatography, and biosensors. At the beginning, only immobilized single enzymes were used, after 1970s more complex systems including two-enzyme reactions with cofactor regeneration and living cells were developed. The enzymes can be attached to the support by interactions ranging from reversible physical adsorption and ionic linkages to stable covalent bonds. Although the choice of the most appropriate immobilization technique depends on the nature of the enzyme and the carrier, in the last years the immobilization technology has increasingly become a matter of rational design. As a consequence of enzyme immobilization, some properties such as catalytic activity or thermal stability become altered. These effects have been demonstrated and exploited. The concept of stabilization has been an important driving force for immobilizing enzymes. Moreover, true stabilization at the molecular level has been demonstrated, e.g., proteins immobilized through multipoint covalent binding. PMID:23934795

  5. Phosphopeptide Enrichment by Immobilized Metal Affinity Chromatography.

    PubMed

    Thingholm, Tine E; Larsen, Martin R

    2016-01-01

    Immobilized metal affinity chromatography (IMAC) has been the method of choice for phosphopeptide enrichment prior to mass spectrometric analysis for many years and it is still used extensively in many laboratories. Using the affinity of negatively charged phosphate groups towards positively charged metal ions such as Fe(3+), Ga(3+), Al(3+), Zr(4+), and Ti(4+) has made it possible to enrich phosphorylated peptides from peptide samples. However, the selectivity of most of the metal ions is limited, when working with highly complex samples, e.g., whole-cell extracts, resulting in contamination from nonspecific binding of non-phosphorylated peptides. This problem is mainly caused by highly acidic peptides that also share high binding affinity towards these metal ions. By lowering the pH of the loading buffer nonspecific binding can be reduced significantly, however with the risk of reducing specific binding capacity. After binding, the enriched phosphopeptides are released from the metal ions using alkaline buffers of pH 10-11, EDTA, or phosphate-containing buffers. Here we describe a protocol for IMAC using Fe(3+) for phosphopeptide enrichment. The principles are illustrated on a semi-complex peptide mixture. PMID:26584922

  6. Metal immobilization in soils using synthetic zeolites.

    PubMed

    Oste, Leonard A; Lexmond, Theo M; Van Riemsdijk, Willem H

    2002-01-01

    In situ immobilization of heavy metals in contaminated soils is a technique to improve soil quality. Synthetic zeolites are potentially useful additives to bind heavy metals. This study selected the most effective zeolite in cadmium and zinc binding out of six synthetic zeolites (mordenite-type, faujasite-type, zeolite X, zeolite P, and two zeolites A) and one natural zeolite (clinoptilolite). Zeolite A appeared to have the highest binding capacity between pH 5 and 6.5 and was stable above pH 5.5. The second objective of this study was to investigate the effects of zeolite addition on the dissolved organic matter (DOM) concentration. Since zeolites increase soil pH and bind Ca, their application might lead to dispersion of organic matter. In a batch experiment, the DOM concentration increased by a factor of 5 when the pH increased from 6 to 8 as a result of zeolite A addition. A strong increase in DOM was also found in the leachate of soil columns, particularly in the beginning of the experiment. This resulted in higher metal leaching caused by metal-DOM complexes. In contrast, the free ionic concentration of Cd and Zn strongly decreased after the addition of zeolites, which might explain the reduction in metal uptake observed in plant growth experiments. Pretreatment of zeolites with acid (to prevent a pH increase) or Ca (to coagulate organic matter) suppressed the dispersion of organic matter, but also decreased the metal binding capacity of the zeolites due to competition of protons or Ca. PMID:12026084

  7. Immobilization of bioactive plasmin reduces the thrombogenicity of metal surfaces.

    PubMed

    Wise, Steven G; Michael, Praveesuda L; Waterhouse, Anna; Santos, Miguel; Filipe, Elysse; Hung, Juichien; Kondyurin, Alexey; Bilek, Marcela M M; Ng, Martin K C

    2015-12-01

    Components of many vascular prostheses including endovascular stents, heart valves and ventricular assist devices are made using metal alloys. In these blood contacting applications, metallic devices promote blood clotting, which is managed clinically by profound platelet suppression and/or anticoagulation. Here it is proposed that the localized immobilization of bioactive plasmin, a critical mediator of blood clot stability, may attenuate metallic prosthesis-induced thrombus formation. Previously described approaches to covalently immobilize biomolecules on implantable materials have relied on complex chemical linker chemistry, increasing the possibility of toxic side effects and reducing bioactivity. We utilize a plasma deposited thin film platform to covalently immobilize biologically active plasmin on stainless steel substrates, including stents. A range of in vitro whole blood assays demonstrate striking reductions in thrombus formation. This approach has profound potential to improve the efficacy of a wide range of metallic vascular implants. PMID:26551872

  8. [Immobilization impact of different fixatives on heavy metals contaminated soil].

    PubMed

    Wu, Lie-shan; Zeng, Dong-mei; Mo, Xiao-rong; Lu, Hong-hong; Su, Cui-cui; Kong, De-chao

    2015-01-01

    Four kinds of amendments including humus, ammonium sulfate, lime, superphosphate and their complex combination were added to rapid immobilize the heavy metals in contaminated soils. The best material was chosen according to the heavy metals' immobilization efficiency and the Capacity Values of the fixative in stabilizing soil heavy metals. The redistributions of heavy metals were determined by the European Communities Bureau of Referent(BCR) fraction distribution experiment before and after treatment. The results were as follows: (1) In the single material treatment, lime worked best with the dosage of 2% compared to the control group. In the compound amendment treatments, 2% humus combined with 2% lime worked best, and the immobilization efficiency of Pb, Cu, Cd, Zn reached 98.49%, 99.40%, 95.86%, 99.21%, respectively. (2) The order of Capacity Values was lime > humus + lime > ammonium sulfate + lime > superphosphate > ammonium sulfate + superphosphate > humus + superphosphate > humus > superphosphate. (3) BCR sequential extraction procedure results indicated that 2% humus combined with 2% lime treatment were very effective in immobilizing heavy metals, better than 2% lime treatment alone. Besides, Cd was activated firstly by 2% humus treatment then it could be easily changed into the organic fraction and residual fraction after the subsequent addition of 2% lime. PMID:25898680

  9. Synthesis and heavy metal immobilization behaviors of slag based geopolymer.

    PubMed

    Yunsheng, Zhang; Wei, Sun; Qianli, Chen; Lin, Chen

    2007-05-01

    In this paper, two aspects of studies are carried out: (1) synthesis of geopolymer by using slag and metakaolin; (2) immobilization behaviors of slag based geopolymer in a presence of Pb and Cu ions. As for the synthesis of slag based geopolymer, four different slag content (10%, 30%, 50%, 70%) and three types of curing regimes (standard curing, steam curing and autoclave curing) are investigated to obtain the optimum synthesis condition based on the compressive and flexural strength. The testing results showed that geopolymer mortar containing 50% slag that is synthesized at steam curing (80 degrees C for 8h), exhibits higher mechanical strengths. The compressive and flexural strengths of slag based geopolymer mortar are 75.2 MPa and 10.1 MPa, respectively. Additionally, Infrared (IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques are used to characterize the microstructure of the slag based geopolymer paste. IR spectra show that the absorptive band at 1086 cm(-1) shifts to lower wave number around 1007 cm(-1), and some six-coordinated Als transforms into four-coordination during the synthesis of slag based geopolymer paste. The resulting slag based geopolymeric products are X-ray amorphous materials. SEM observation shows that it is possible to have geopolymeric gel and calcium silicate hydrate (C-S-H) gel forming simultaneously within slag based geopolymer paste. As for immobilization of heavy metals, the leaching tests are employed to investigate the immobilization behaviors of the slag based geopolymer mortar synthesized under the above optimum condition. The leaching tests show that slag based geopolymer mortar can effectively immobilize Cu and Pb heavy metal ions, and the immobilization efficiency reach 98.5% greater when heavy metals are incorporated in the slag geopolymeric matrix in the range of 0.1-0.3%. The Pb exhibits better immobilization efficiency than the Cu in the case of large dosages of heavy metals. PMID:17034943

  10. [Immobilization of heavy metal Pb2+ with geopolymer].

    PubMed

    Jin, Man-tong; Jin, Zan-fang; Huang, Cai-ju

    2011-05-01

    A series of geopolymers were synthesized by mixing metakaolinite, water glass, sodium hydroxide and water, and the lead ion solidification experiments were performed with the geopolymer. Then, the immobilization efficiency was characterized by monitoring the leaching concentration and compressive strength of solidified products. Additionally, the structure and properties of the solidified products were studied by X-ray diffraction (XRD), scan electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Furthermore, based on the analysis of immobilization efficiency, microstructure and mineral structure, the difference between geopolymer and cement on the performance of immobilizing heavy metals was discussed. The results of lead ion immobilization experiments showed that over 99.7% of heavy metal was captured by the geopolymer as the doping concentration of lead ion was less than 3%. Meanwhile, the compressive strength of the solidified product ranged from 40 MPa to 50 MPa. Furthermore, by using the same Pb2+ concentration, the geopolymer showed higher compressive strength and lower leaching concentration compared to the cement. Because lead ion participated in constitution of structure of geopolymer, or Pb2+ was adsorbed by the aluminium ions on the geopolymeric skeleton and held in geopolymer. However, cement mainly solidified lead ion by physical encapsulation and adsorption mechanism. Therefore, both from the compressive strength and leaching concentration and from the microstructure characterization as well as the mechanism of the geopolymerization reaction, the geopolymer has more advantages in immobilizing Pb2+ than the cement. PMID:21780604

  11. Synchrotron Analysis Of Metal Immobilization In Sediments

    EPA Science Inventory

    Heavy metal contamination is a problem at many marine and fresh water environments as a result of industrial and military activities. Metals such as lead (Pb), zinc (Zn), copper (Cu), and chromium (Cr) are common contaminants in sediments due to many Navy activities. The mobile...

  12. Enrichment of Phosphopeptides via Immobilized Metal Affinity Chromatography.

    PubMed

    Swaney, Danielle L; Villén, Judit

    2016-03-01

    Immobilized metal affinity chromatography (IMAC) is a frequently used method for the enrichment of phosphorylated peptides from complex, cellular lysate-derived peptide mixtures. Here we outline an IMAC protocol that uses iron-chelated magnetic beads to selectively isolate phosphorylated peptides for mass spectrometry-based proteomic analysis. Under acidic conditions, negatively charged phosphoryl modifications preferentially bind to positively charged metal ions (e.g., Fe(3+), Ga(3+)) on the beads. After washing away nonphosphorylated peptides, a pH shift to basic conditions causes the elution of bound phosphopeptides from the metal ion. Under optimal conditions, very high specificity for phosphopeptides can be achieved. PMID:26933247

  13. Adsorption of heavy metal ions by immobilized phytic acid

    SciTech Connect

    Tsao, G.T.; Zheng, Yizhou; Lu, J.; Gong, Cheng S.

    1997-12-31

    Phytic acid (myoinositol hexaphosphate) or its calcium salt, phytate, is an important plant constituents. It accounts for up to 85% of total phosphorus in cereals and legumes. Phytic acid has 12 replaceable protons in the phytic molecule rendering it the ability to complex with multivalent cations and positively charged proteins. Poly 4-vinyl pyridine (PVP) and other strong-based resins have the ability to adsorb phytic acid. PVP has the highest adsorption capacity of 0.51 phytic acid/resins. The PVP resin was used as the support material for the immobilization of phytic acid. The immobilized phytic acid can adsorb heavy metal ions, such as cadmium, copper, lead, nickel, and zinc ions, from aqueous solutions. Adsorption isotherms of the selected ions by immobilized phytic acid were conducted in packed-bed column at room temperature. Results from the adsorption tests showed 6.6 mg of Cd{sup 2+}, 7 mg of Cu{sup 2+}, 7.2 mg of Ni{sup 2+}, 7.4 mg of Pb{sup 2+}, and 7.7 mg of Zn{sup 2+} can be adsorbed by each gram of PVP-phytic acid complex. The use of immobilized phytic acid has the potential for removing metal ions from industrial or mining waste water. 15 refs., 7 figs., 2 tabs.

  14. Immobilization of heavy metals and phenol on altered bituminous coals

    SciTech Connect

    Taraba, B.; Marsalek, R.

    2007-07-01

    This article evaluates adsorption ability of the altered bituminous coals to remove heavy metals and/or phenol from aqueous solutions. As for heavy metals, copper (II), cadmium (II) and lead (II) cations were used. In addition to phenol, cyclohexanol and 2-cyclohexen-1-ol were also examined. Adsorption experiments were conducted in the batch mode at room temperature and at pH 3 and 5. To characterize the texture of coal samples, adsorption isotherms of nitrogen at - 196{sup o}C, enthalpies of the immersion in water, and pH values in aqueous dispersions were measured. Coal hydrogen aromaticities were evaluated from the infrared spectrometric examinations (DRIFTS). Based on the investigations performed, cation exchange was confirmed as the principal mechanism to immobilize heavy metallic ions on coals. However, apart from carboxylic groups, other functionalities (hydroxyl groups) were found to be involved in the adsorption process. During adsorption of phenol, {pi}-{pi} interactions between {pi}-electrons of phenol and aromatic rings of coal proved to play the important role; however, no distinct correlation between adsorption capacities for phenol and hydrogen aromaticities of the coal was found. Probable involvement of oxygenated surface groups in the immobilization of phenol on coal was deduced. As a result, for waste water treatment, oxidative altered bituminous coal can be recommended as a suitable precursor, with the largest immobilization capacities both for metallic ions and phenol, as found in the studied samples.

  15. Covalent immobilization of liposomes on plasma functionalized metallic surfaces.

    PubMed

    Mourtas, S; Kastellorizios, M; Klepetsanis, P; Farsari, E; Amanatides, E; Mataras, D; Pistillo, B R; Favia, P; Sardella, E; d'Agostino, R; Antimisiaris, S G

    2011-05-01

    A method was developed to functionalize biomedical metals with liposomes. The novelty of the method includes the plasma-functionalization of the metal surface with proper chemical groups to be used as anchor sites for the covalent immobilization of the liposomes. Stainless steel (SS-316) disks were processed in radiofrequency glow discharges fed with vapors of acrylic acid to coat them with thin adherent films characterized by surface carboxylic groups, where liposomes were covalently bound through the formation of amide bonds. For this, liposomes decorated with polyethylene glycol molecules bearing terminal amine-groups were prepared. After ensuring that the liposomes remain intact, under the conditions applying for immobilization; different attachment conditions were evaluated (incubation time, concentration of liposome dispersion) for optimization of the technique. Immobilization of calcein-entrapping liposomes was evaluated by monitoring the percent of calcein attached on the surfaces. Best results were obtained when liposome dispersions with 5mg/ml (liposomal lipid) concentration were incubated on each disk for 24h at 37°C. The method is proposed for developing drug-eluting biomedical materials or devices by using liposomes that have appropriate membrane compositions and are loaded with drugs or other bioactive agents. PMID:21273051

  16. Molecular nanotechnologies of gelatin-immobilization using macrocyclic metal chelates

    PubMed Central

    Mikhailov, Oleg V.

    2014-01-01

    This article is a review of recent developments in the self-assembled nanostructures based on chelate coordination compounds. Molecular nanotechnologies of self-assembly of 3d-element aza- and thiazametalmacrocyclic complexes that happen in nanoreactors on the basis of metal hexacyanoferrate(II) gelatin-immobilized matrix under their contact with water solutions containing various (N,O,S)-donor atomic ligands and organic compounds having one or two carbonyl groups have been considered in this review. It has been noted that the assortment of macrocyclic metal chelates obtained as a result of using molecular nanotechnologies in such specific conditions considerably differs from the assortment of metal chelates formed at the conditions traditional for chemical synthesis. PMID:24516711

  17. Ultrafine metal particles immobilized on styrene/acrylic acid copolymer particles

    SciTech Connect

    Tamai, Hisashi; Hamamoto, Shiro; Nishiyama, Fumitaka; Yasuda, Hajime

    1995-04-01

    Ultrafine metal particles immobilized on styrene/acrylic acid copolymer fine particles were produced by reducing the copolymer particles-metal ion complexes or refluxing an ethanol solution of metal ions in the presence of copolymer particles. The size of metal particles formed by reduction of the complex is smaller than that by reflux of the metal ion solution and depends on the amount of metal ions immobilized.

  18. Biosorption of metal contaminants using immobilized biomass--Field studies

    SciTech Connect

    Jeffers, T.H.; Bennett, P.G.; Corwin, R.R.

    1993-01-01

    The US Bureau of Mines has developed porous beads containing immobilized biological materials such as sphagnum peat moss for extracting metal contaminants from waste waters. The beads, designated as BIO-FIX beads, have removed toxic metals from over 100 waters in laboratory tests. These waters include acid mine drainage (AMD) water from mining sites, metallurgical and chemical industry waste water, and contaminated ground water. Following the laboratory studies, cooperative field tests were conducted to evaluate the metal adsorption properties of the beads in column and low-maintenance circuits, determine bead stability in varied climatic situations, and demonstrate the beads' potential as a viable waste water treatment technique. Field results indicated that BIO-FIX beads readily adsorbed cadmium, lead, and other toxic metals from dilute waters; effluents frequently met drinking water standards and other discharge criteria. The beads exhibited excellent handling characteristics in both column and low-maintenance circuits, and continued to extract metal ions after repeated loading-elution cycles. Based on laboratory and field data, cost evaluations for using BIO-FIX technology to treat two AMD waters were prepared. Operating costs for BIO-FIX treatment, which ranged from $1.40 to $2.30 per 1,000 gal of water treated, were comparable with chemical precipitation costs.

  19. [In situ immobilization remediation of heavy metals-contaminated soils: a review].

    PubMed

    Wang, Li-Qun; Luo, Lei; Ma, Yi-Bing; Wei, Dong-Pu; Hua, Luo

    2009-05-01

    In situ immobilization of heavy metals in contaminated soils by adding extraneous active amendments has been considered as a cost-effective measure for contaminated soil remediation. Application of immobilization amendments can decrease the available fractions of heavy metals or change their redox states, and thus, effectively decrease the mobility, bioavailability, and toxicity of the heavy metals in soils. This paper summarized the present researches about the in situ immobilization of heavy metals in soils, including kinds of immobilization amendments, research methods, immobilization indexes, immobilization mechanisms, and relevant environmental risk assessment. The mostly applied amendments include clay minerals, phosphates, organic composts, and microbes. Due to the complexity of soil matrix and the limitations of current analytical techniques, the exact immobilization mechanisms have not been clarified, which could include precipitation, chemical adsorption and ion exchange, surface precipitation, formation of stable complexes with organic ligands, and redox reaction. The prospects and limitations of in situ immobilization of heavy metals in soils were discussed. Future work should focus on the elucidation of immobilization mechanisms at molecular scale, with specific attention be paid to the potential risks of applying immobilization amendments and its long-term effects on field soils. PMID:19803184

  20. Active Immobilized Antibiotics Based on Metal Hydroxides1

    PubMed Central

    Kennedy, John F.; Humphreys, John D.

    1976-01-01

    The water-insoluble hydroxides of zirconium (IV), titanium (IV), titanium (III), iron (II), vanadium (III), and tin (II) have been used to prepare insoluble derivatives of a cyclic peptide antibiotic by a facile chelation process. Testing of the antibacterial activities of the products against two gram-positive and two gram-negative bacteria showed that in the majority of cases the water-insoluble antibiotics remained active against those bacteria susceptible to the parent antibiotic. The power of the assay system has been extended by the novel use of colored organisms to aid determinations where the growth of normal organisms could not be distinguished from the appearance of the supporting material. Insoluble derivatives of neomycin, polymyxin B, streptomycin, ampicillin, penicillin G, and chloramphenicol were prepared by chelation with zirconium hydroxide, and these derivatives similarly reflected the antibacterial activities of the parent compounds. Several of the metal hydroxides themselves possess antibacterial activity due to complex formation with the bacteria. However, the use of selected metal hydroxides can afford a simple, inexpensive, and inert matrix for antibiotic immobilization, resulting in an antibacterial product that may possess slow-release properties. The mechanisms by which the metal hydroxide-antibiotic association-dissociation may occur are discussed. PMID:949174

  1. Metal organic frameworks for enzyme immobilization in biofuel cells

    NASA Astrophysics Data System (ADS)

    Bodell, JaDee

    Interest in biofuel cells has been rapidly expanding as an ever-growing segment of the population gains access to electronic devices. The largest areas of growth for new populations using electronic devices are often in communities without electrical infrastructure. This lack of infrastructure in remote environments is one of the key driving factors behind the development of biofuel cells. Biofuel cells employ biological catalysts such as enzymes to catalyze oxidation and reduction reactions of select fuels to generate power. There are several benefits to using enzymes to catalyze reactions as compared to traditional fuel cells which use metal catalysts. First, enzymes are able to catalyze reactions at or near room temperature, whereas traditional metal catalysts are only efficient at very high temperatures. Second, biofuel cells can operate under mild pH conditions which is important for the eventual design of safe, commercially viable devices. Also, biofuel cells allow for implantable and flexible technologies. Finally, enzymes exhibit high selectivity and can be combined to fully oxidize or reduce the fuel which can generate several electrons from a single molecule of fuel, increasing the overall device efficiency. One of the main challenges which persist in biofuel cells is the instability of enzymes over time which tend to denature after hours or days. For a viable commercial biofuel cell to be produced, the stability of enzymes must be extended to months or years. Enzymes have been shown to have improved stability after being immobilized. The focus of this research was to find a metal organic framework (MOF) structure which could successfully immobilize enzymes while still allowing for electron transport to occur between the catalytic center of the enzyme and the electrode surface within a biofuel cell for power generation. Four MOF structures were successfully synthesized and were subsequently tested to determine the MOF's ability to immobilize the following

  2. A general method for immobilization of glycoproteins on regenerable immobilized metal-ion carriers: application to glucose oxidase from Penicillium chrysogenum and horseradish peroxidase.

    PubMed

    Chaga, G

    1994-08-01

    A general method for immobilization of glycoproteins on immobilized metal-ion carriers is described. The method includes oxidation of the carbohydrate moiety of the glycoprotein with potassium periodate, covalent modification with histidine and immobilization on bivalent metal ion-iminodiacetic acid-agarose. The method is exemplified with horseradish peroxidase and glucose oxidase from Penicillium chrysogenum. The modified and immobilized enzymes are stable for at least 2 months at 4 degrees C. The immobilized enzymes were used as enzyme electrodes for the determination of the glucose concentration. PMID:7917065

  3. Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials

    SciTech Connect

    Wang, Yifeng; Miller, Andy; Bryan, Charles R; Kruichar, Jessica Nicole

    2015-04-07

    Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials are described. For example, a method of capturing and immobilizing radioactive nuclei includes flowing a gas stream through an exhaust apparatus. The exhaust apparatus includes a metal fluorite-based inorganic material. The gas stream includes a radioactive species. The radioactive species is removed from the gas stream by adsorbing the radioactive species to the metal fluorite-based inorganic material of the exhaust apparatus.

  4. Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials

    DOEpatents

    Wang, Yifeng; Miller, Andy; Bryan, Charles R.; Kruichak, Jessica Nicole

    2015-11-17

    Methods of capturing and immobilizing radioactive nuclei with metal fluorite-based inorganic materials are described. For example, a method of capturing and immobilizing radioactive nuclei includes flowing a gas stream through an exhaust apparatus. The exhaust apparatus includes a metal fluorite-based inorganic material. The gas stream includes a radioactive species. The radioactive species is removed from the gas stream by adsorbing the radioactive species to the metal fluorite-based inorganic material of the exhaust apparatus.

  5. Polymer versus monomer as displacer in immobilized metal affinity chromatography.

    PubMed

    Arvidsson, P; Ivanov, A E; Galaev IYu; Mattiasson, B

    2001-04-01

    Successful immobilized metal affinity chromatography (IMAC) of proteins on Cu2+-iminodiacetic acid Sepharose has been carried out in a displacement mode using a synthetic copolymer of vinyl imidazole and vinyl caprolactam [poly(VI-VCL)] as a displacer. Vinyl caprolactam renders the co-polymer with the thermosensitivity, e.g., property of the co-polymer to precipitate nearly quantitatively from aqueous solution on increase of the temperature to 48 degrees C. A thermostable lactate dehydrogenase from the thermophilic bacterium Bacillus stearothermophilus modified with a (His)6-tag [(His)6-LDH] has been purified using an IMAC column. For the first time it was clearly demonstrated that a polymeric displacer [poly(VI-VCL)] was more efficient compared to a monomeric displacer (imidazole) of the same chemical nature, probably due to the multipoint interaction of imidazole groups within the same macromolecule with one Cu2+ ion. Complete elution of bound (His)6-LDH has been achieved at 3.7 mM concentration of imidazole units of the co-polymer (5 mg/ml), while this concentration of free imidazole was sufficient to elute only weakly bound proteins. Complete elution of (His)6-LDH by the free imidazole was achieved only at concentrations as high as 160 mM. Thus, it was clearly demonstrated, that the efficiency of low-molecular-mass displacer could be improved significantly by converting it into a polymeric displacer having interacting groups of the same chemical nature. PMID:11334341

  6. Potential immobilized Saccharomyces cerevisiae as heavy metal removal

    NASA Astrophysics Data System (ADS)

    Raffar, Nur Izzati Abdul; Rahman, Nadhratul Nur Ain Abdul; Alrozi, Rasyidah; Senusi, Faraziehan; Chang, Siu Hua

    2015-05-01

    Biosorption of copper ion using treated and untreated immobilized Saccharomyces cerevisiae from aqueous solution was investigate in this study. S.cerevisiae has been choosing as biosorbent due to low cost, easy and continuously available from various industries. In this study, the ability of treated and untreated immobilized S.cerevisiae in removing copper ion influence by the effect of pH solution, and initial concentration of copper ion with contact time. Besides, adsorption isotherm and kinetic model also studied. The result indicated that the copper ion uptake on treated and untreated immobilized S.cerevisiae was increased with increasing of contact time and initial concentration of copper ion. The optimum pH for copper ion uptake on untreated and treated immobilized S.cerevisiae at 4 and 6. From the data obtained of copper ion uptake, the adsorption isotherm was fitted well by Freundlich model for treated immobilized S.cerevisiae and Langmuir model for untreated immobilized S.cerevisiae according to high correlation coefficient. Meanwhile, the pseudo second order was described as suitable model present according to high correlation coefficient. Since the application of biosorption process has been received more attention from numerous researchers as a potential process to be applied in the industry, future study will be conducted to investigate the potential of immobilized S.cerevisiae in continuous process.

  7. Epsilon Metal Waste Form for Immobilization of Noble Metals from Used Nuclear Fuel

    SciTech Connect

    Crum, Jarrod V.; Strachan, Denis M.; Rohatgi, Aashish; Zumhoff, Mac R.

    2013-10-01

    Epsilon metal (ε-metal), an alloy of Mo, Pd, Rh, Ru, and Tc, is being developed as a waste form to treat and immobilize the undissolved solids and dissolved noble metals from aqueous reprocessing of commercial used nuclear fuel. Epsilon metal is an attractive waste form for several reasons: increased durability relative to borosilicate glass, it can be fabricated without additives (100% waste loading), and in addition it also benefits borosilicate glass waste loading by eliminating noble metals from the glass and thus the processing problems related there insolubility in glass. This work focused on the processing aspects of the epsilon metal waste form development. Epsilon metal is comprised of refractory metals resulting in high reaction temperatures to form the alloy, expected to be 1500 - 2000°C making it a non-trivial phase to fabricate by traditional methods. Three commercially available advanced technologies were identified: spark-plasma sintering, microwave sintering, and hot isostatic pressing, and investigated as potential methods to fabricate this waste form. Results of these investigations are reported and compared in terms of bulk density, phase assemblage (X-ray diffraction and elemental analysis), and microstructure (scanning electron microscopy).

  8. Studies of Immobilized Homogeneous Metal Catalysts on Silica Supports

    SciTech Connect

    Keith James Stanger

    2003-05-31

    The tethered, chiral, chelating diphosphine rhodium complex, which catalyzes the enantioselective hydrogenation of methyl-{alpha}-acetamidocinnamate (MAC), has the illustrated structure as established by {sup 31}P NMR and IR studies. Spectral and catalytic investigations also suggest that the mechanism of action of the tethered complex is the same as that of the untethered complex in solution. The rhodium complexes, [Rh(COD)H]{sub 4}, [Rh(COD){sub 2}]{sup +}BF{sub 4}{sup -}, [Rh(COD)Cl]{sub 2}, and RhCl{sub 3} {center_dot} 3H{sub 2}O, adsorbed on SiO{sub 2} are optimally activated for toluene hydrogenation by pretreatment with H{sub 2} at 200 C. The same complexes on Pd-SiO{sub 2} are equally active without pretreatments. The active species in all cases is rhodium metal. The catalysts were characterized by XPS, TEM, DRIFTS, and mercury poisoning experiments. Rhodium on silica catalyzes the hydrogenation of fluorobenzene to produce predominantly fluorocyclohexane in heptane and 1,2-dichloroethane solvents. In heptane/methanol and heptane/water solvents, hydrodefluorination to benzene and subsequent hydrogenation to cyclohexane occurs exclusively. Benzene inhibits the hydrodefluorination of fluorobenzene. In DCE or heptane solvents, fluorocyclohexane reacts with hydrogen fluoride to form cyclohexene. Reaction conditions can be chosen to selectively yield fluorocyclohexane, cyclohexene, benzene, or cyclohexane. The oxorhenium(V) dithiolate catalyst [-S(CH{sub 2}){sub 3}s-]Re(O)(Me)(PPh{sub 3}) was modified by linking it to a tether that could be attached to a silica support. Spectroscopic investigation and catalytic oxidation reactivity showed the heterogenized catalyst's structure and reactivity to be similar to its homogeneous analog. However, the immobilized catalyst offered additional advantages of recyclability, extended stability, and increased resistance to deactivation.

  9. Immobilization of EAFD heavy metals using acidic materials.

    PubMed

    Mitrakas, Manassis G; Sikalidis, Constantinos A; Karamanli, Theoktisti P

    2007-03-01

    This study was undertaken to determine the chemical and leaching characteristics of the Electric Arc Furnace Dust (EAFD) generated by a Greek plant and to investigate various acidic materials efficiency on the EAFD stabilization. In order to investigate how [OH(-)] neutralization influences EAFD heavy metals leachability, Na HCO3(-), HNO3 and H3PO4 were used as acidic materials. The concentration of Pb in leachate was found between 40 and 3.7 x 10(3) mg Pb/kg of EAFD, exceeding in all EAFD samples the maximum acceptable limit (MAL) 25 mg/kg for landfill disposal. Neutralization of [OH(-)] with HCO3(-) decreased Pb concentration in leachate at 350 mg Pb/kg of EAFD, while excess over a stoichiometry in HCO3(-) addition increased leachability of Pb, Cd, Cr, Cu as well as F. Using HNO3 as an acidic material decreased leachability of almost all the parameters concerning the EC directive 33/19-01-2003 in a pH value up to 7.2, in exception of Zn. Zinc leachability showed a U shape curve as a function of pH value. The concentration of Zn was minimized in a concentration lower than 1 mg Zn/kg EAFD in a pH range 10.5 to 9 and exceeded the MAL 90 mg/kg at a pH value 7.2. However, the major disadvantage of HNO3 was proved to be its leachability, since NO3(-) concentration in leachate was equal to HNO3 dose. H3PO4 was found the most promising acidic material for the chemical immobilization of heavy metals, since it decreased their leachability in a concentration significantly lower than MAL at a pH value up to 7.1. Finally, the concentration of Cl(-) ranged between 18 and 33 x 10(3) mg Cl(-)/kg EAFD exceeding in all EAFD samples the MAL 17 x 10(3) mg/kg. This high concentration of Cl(-) is attributed to the scrap and it could be reduced only by modification of its composition. PMID:17365324

  10. Final Report: Role of microbial synergies in immobilization of metals

    SciTech Connect

    Slava Epstein, Ph.D. and Kim Lewis, Ph.D.

    2012-11-14

    This Subsurface Microbial Ecology and Community Dynamics project tested the following hypothesis: synergistic groups of microorganisms immobilize heavy elements more efficiently than do individual species. We focused on groundwater at several DOE FRC and their microbial communities affecting the fate of U, Tc, and Cr. While we did not obtain evidence to support the original hypothesis, we developed a platform to accessing novel species from the target environments. We implemented this technology and discovered and isolated novel species capable of immobilization of uranium and species with exceptionally high resistances to the extant toxic factors. We have sequenced their genomes are are in the process of investigating the genomic contents behind these surprising resistances.

  11. Hydrogels for immobilization of bacteria used in the treatment of metal-contaminated wastes

    NASA Astrophysics Data System (ADS)

    Degiorgi, C. Fernández; Pizarro, R. A.; Smolko, E. E.; Lora, S.; Carenza, M.

    2002-01-01

    Polymeric matrices prepared by gamma irradiation of 2-hydroxyethyl methacrylate and 2-hydroxyethyl acrylate at -78°C in the presence of water and glycerol and poly(vinyl alcohol) membranes were examined as carriers for immobilization of bacterial cells in experiments of metal decontamination. Bacterial strains capable of growing in the presence of heavy metals were selected from soil and water from the Rı´o de la Plata coasts in Argentina and cultured in the hydrophilic membranes with the aim of bioremediation of the standard contaminated solutions. The results obtained indicate that removal from free bacteria was more efficient for Pb(II) and Cd(II) than for Cr(III) and Cu(II). It was ascertained that all metals could be immobilized in the polymer matrices to some extent. The Cr(III) ion concentration in bacteria immobilized on the acrylic hydrogel was approximately double of that found in the poly(vinyl alcohol) membrane.

  12. Immobilized materials for removal of toxic metal ions from surface/groundwaters and aqueous waste streams.

    PubMed

    Zawierucha, Iwona; Kozlowski, Cezary; Malina, Grzegorz

    2016-04-20

    Heavy metals from industrial processes are of special concern because they produce chronic poisoning in the aquatic environment. More strict environmental regulations on the discharge of toxic metals require the development of various technologies for their removal from polluted streams (i.e. industrial wastewater, mine waters, landfill leachate, and groundwater). The separation of toxic metal ions using immobilized materials (novel sorbents and membranes with doped ligands), due to their high selectivity and removal efficiency, increased stability, and low energy requirements, is promising for improving the environmental quality. This critical review is aimed at studying immobilized materials as potential remediation agents for the elimination of numerous toxic metal (e.g. Pb, Cd, Hg, and As) ions from polluted streams. This study covers the general characteristics of immobilized materials and separation processes, understanding of the metal ion removal mechanisms, a review of the application of immobilized materials for the removal of toxic metal ions, as well as the impacts of various parameters on the removal efficiency. In addition, emerging trends and opportunities in the field of remediation technologies using these materials are addressed. PMID:27044908

  13. Bioinspired Immobilization of Glycerol Dehydrogenase by Metal Ion-Chelated Polyethyleneimines as Artificial Polypeptides

    PubMed Central

    Zhang, Yonghui; Ren, Hong; Wang, Yali; Chen, Kainan; Fang, Baishan; Wang, Shizhen

    2016-01-01

    In this study, a novel, simple and generally applicable strategy for multimeric oxidoreductase immobilization with multi-levels interactions was developed and involved activity and stability enhancements. Linear polyethyleneimines (PEIs) are flexible cationic polymers with molecular weights that span a wide range and are suitable biomimic polypeptides for biocompatible frameworks for enzyme immobilization. Metal ion-chelated linear PEIs were applied as a heterofunctional framework for glycerol dehydrogenase (GDH) immobilization by hydrogen bonds, electrostatic forces and coordination bonds interactions. Nanoparticles with diameters from 250–650 nm were prepared that exhibited a 1.4-fold enhancement catalytic efficiency. Importantly, the half-life of the immobilized GDH was enhanced by 5.6-folds in aqueous phase at 85 °C. A mechanistic illustration of the formation of multi-level interactions in the PEI-metal-GDH complex was proposed based on morphological and functional studies of the immobilized enzyme. This generally applicable strategy offers a potential technique for multimeric enzyme immobilization with the advantages of low cost, easy operation, high activity reservation and high stability. PMID:27053034

  14. Effect of grain size and heavy metals on As immobilization by marble particles.

    PubMed

    Simón, M; García, I; González, V; Romero, A; Martín, F

    2015-05-01

    The effect of grain size and the interaction of heavy metals on As sorption by marble waste with different particle sizes was investigated. Acidic solutions containing only arsenic and a mixture of arsenic, lead, zinc, and cadmium were put in contact with the marble waste. The amount of metal(loid)s that were immobilized was calculated using the difference between the concentration in the acidic solution and in the liquid phase of the suspensions. Approximately 420 μg As m(-2) was sorbed onto the marble grains, both nonspecifically and specifically, where ≥ 80 % of the total arsenic in the acidic solution remained soluble, which suggests that this amendment is not effective to immobilize arsenic. However, in mixed contamination, relatively stable Pb-Ca arsenates were formed on the surface of the marble particles, and the soluble arsenic was reduced by 95 %, which indicates that marble particles can effectively immobilize arsenic and lead when both appear together. PMID:25432428

  15. Heavy metal removal by novel CBD-EC20 sorbents immobilized on cellulose.

    PubMed

    Xu, Zhaohui; Bae, Weon; Mulchandani, Ashok; Mehra, Rajesh K; Chen, Wilfred

    2002-01-01

    Heavy metals are major contributors to pollution of the biosphere, and their efficient removal from contaminated water is required. Biosorption is an emerging technology that has been shown to be effective in removing very low levels of heavy metal from wastewater. Although peptides such as metallothioneins or phytotchelatins are known to immobilize heavy metals, peptide-based biosorbents have not been extensively investigated. In this paper, we describe the construction and expression of bifunctional fusion proteins consisting of synthetic phytochelatin (EC20) linked to a Clostridium-derived cellulose-binding domain (CBD(clos)), enabling purification and immobilization of the fusions onto different cellulose materials in essentially a single step. The immobilized sorbents were shown to be highly effective in removing cadmium at parts per million levels. Repeated removal of cadmium was demonstrated in an immobilized column. The ability to genetically engineer biosorbents with precisely defined properties could provide an attractive strategy for developing high-affinity bioadsorbents suitable for heavy metal removal. PMID:12005515

  16. Polyurethane and alginate immobilized algal biomass for the removal of aqueous toxic metals

    SciTech Connect

    Fry, I.V.; Mehlhorn, R.J.

    1992-12-01

    We describe the development of immobilized, processed algal biomass for use as an adsorptive filter in the removal of toxic metals from waste water. To fabricate an adsorptive filter from precessed biomass several crucial criteria must be met, including: (1) high metal binding capacity, (2) long term stability (both mechanical and chemical), (3) selectivity for metals of concern (with regard to ionic competition), (4) acceptable flow capacity (to handle large volumes in short time frames), (5) stripping/regeneration (to recycle the adsorptive filter and concentrate the toxic metals to manageable volumes). This report documents experiments with processed algal biomass (Spirulina platensis and Spirulina maxima) immobilized in either alginate gel or preformed polyurethane foam. The adsorptive characteristics of these filters were assessed with regard to the criteria listed above.

  17. Immobilization of Technetium in a Metallic Waste Form

    SciTech Connect

    S.M. Frank; D. D. Keiser, Jr.; K. C. Marsden

    2007-09-01

    Fission-product technetium accumulated during treatment of spent nuclear fuel will ultimately be disposed of in a geological repository. The exact form of Tc for disposal has yet to be determined; however, a reasonable solution is to incorporate elemental Tc into a metallic waste form similar to the waste form produced during the pyrochemical treatment of spent, sodium-bonded fuel. This metal waste form, produced at the Idaho National Laboratory, has undergone extensive qualification examination and testing for acceptance to the Yucca Mountain geological repository. It is from this extensive qualification effort that the behavior of Tc and other fission products in the waste form has been elucidated, and that the metal waste form is extremely robust in the retention of fission products, such as Tc, in repository like conditions. This manuscript will describe the metal waste form, the behavior of Tc in the waste form; and current research aimed at determining the maximum possible loading of Tc into the metal waste and subsequent determination of the performance of high Tc loaded metal waste forms.

  18. Evaluation of Quantitative Performance of Sequential Immobilized Metal Affinity Chromatographic Enrichment for Phosphopeptides

    PubMed Central

    Sun, Zeyu; Hamilton, Karyn L.; Reardon, Kenneth F.

    2014-01-01

    We evaluated a sequential elution protocol from immobilized metal affinity chromatography (SIMAC) employing gallium-based immobilized metal affinity chromatography (IMAC) in conjunction with titanium-dioxide-based metal oxide affinity chromatography (MOAC). The quantitative performance of this SIMAC enrichment approach, assessed in terms of repeatability, dynamic range, and linearity, was evaluated using a mixture composed of tryptic peptides from caseins, bovine serum albumin, and phosphopeptide standards. While our data demonstrate the overall consistent performance of the SIMAC approach under various loading conditions, the results also revealed that the method had limited repeatability and linearity for most phosphopeptides tested, and different phosphopeptides were found to have different linear ranges. These data suggest that, unless additional strategies are used, SIMAC should be regarded as a semi-quantitative method when used in large-scale phosphoproteomics studies in complex backgrounds. PMID:24096195

  19. Purification of proteins containing zinc finger domains using Immobilized Metal Ion Affinity Chromatography

    PubMed Central

    Voráčková, Irena; Suchanová, Šárka; Ulbrich, Pavel; Diehl, William E.; Ruml, Tomáš

    2011-01-01

    Heterologous proteins are frequently purified by Immobilized Metal Ion Affinity Chromatography (IMAC) based on their modification with a hexa-histidine affinity tag (His-tag). The terminal His-tag can, however, alter functional properties of the tagged protein. Numerous strategies for the tag removal have been developed including chemical treatment and insertion of protease target sequences in the protein sequence. Instead of using these approaches, we took an advantage of natural interaction of zinc finger domains with metal ions to purify functionally similar retroviral proteins from two different retroviruses. We found that these proteins exhibited significantly different affinities to the immobilized metal ions, despite that both contain the same type of zinc finger motif (i.e. CCHC). While zinc finger proteins may differ in biochemical properties, the multitude of IMAC platforms should allow relatively simple yet specific method for their isolation in native state. PMID:21600288

  20. Enzyme immobilization on a nanoadsorbent for improved stability against heavy metal poisoning.

    PubMed

    Pogorilyi, R P; Melnyk, I V; Zub, Y L; Seisenbaeva, G A; Kessler, V G

    2016-08-01

    Magnetic nanoparticles modified with siloxane layers bearing amino and thiol functions have been used for immobilization of urease either by adsorption or via surface grafting. The activity of the immobilized enzyme in the hydrolysis of urea extended to the levels typical of the native enzyme, while its long-term stability in combination with magnetic retraction opened for its repeated use in both analysis and detoxification of bio-fluids. The immobilized urease revealed strongly enhanced stability and 65% activity in the presence of 0.1mmol/l of Hg(2+) or 0.3mmol/l of Cu(2+) while the native urease did not retain any activity at all. The enzyme grafting was shown to be a potentially perspective tool in alleviation of heavy metal poisoning and to be providing an opportunity for use of the developed adsorbents as both biosensors and bio-reactants for removal of urea from biofluids. PMID:27085045

  1. METAL BIOACCUMULATION IN FISHES AND AQUATIC INVERTEBRATES: A LITERATURE REVIEW

    EPA Science Inventory

    Literature concerning the bioaccumulation of metals by freshwater and marine fishes and invertebrates has been reviewed; metal residue levels are also reported for a few mammals and plants. Twenty-one metals are considered in individual sections of the review and a bibliography o...

  2. Biosorption of metal contaminants using immobilized biomass: A laboratory study. Rept. of Investigations/1991

    SciTech Connect

    Jeffers, T.H.; Ferguson, C.R.; Bennett, P.G.

    1991-01-01

    The U.S. Bureau of Mines has developed porous beads containing immobilized biological materials for removing metal contaminants from waste waters. The beads, designated as BIO-FIX beads, are prepared by blending biomass, such as sphagnum peat moss or algae, into a polymer solution and spraying the mixture into water. Laboratory studies were conducted to determine bead sorption and elution characteristics. Batch and continuous tests demonstrated that BIO-FIX beads sorbed arsenic, cadmium, lead, and other toxic metals from acid mine drainage waters collected from several sites. Selectivity for heavy and toxic metal ions over calcium and magnesium was demonstrated. The beads exhibited excellent metal sorption and handling characteristics in stirred tanks, column contactors, and a low-maintenance passive system. The sorption process was reversible, and metal ions were eluted from the beads using dilute mineral acids. Cyclic tests indicated that the beads continued to extract metal ions after repeated loading-elution cycles.

  3. Preparation of metal-resistant immobilized sulfate reducing bacteria beads for acid mine drainage treatment.

    PubMed

    Zhang, Mingliang; Wang, Haixia; Han, Xuemei

    2016-07-01

    Novel immobilized sulfate-reducing bacteria (SRB) beads were prepared for the treatment of synthetic acid mine drainage (AMD) containing high concentrations of Fe, Cu, Cd and Zn using up-flow anaerobic packed-bed bioreactor. The tolerance of immobilized SRB beads to heavy metals was significantly enhanced compared with that of suspended SRB. High removal efficiencies of sulfate (61-88%) and heavy metals (>99.9%) as well as slightly alkaline effluent pH (7.3-7.8) were achieved when the bioreactor was fed with acidic influent (pH 2.7) containing high concentrations of multiple metals (Fe 469 mg/L, Cu 88 mg/L, Cd 92 mg/L and Zn 128 mg/L), which showed that the bioreactor filled with immobilized SRB beads had tolerance to AMD containing high concentrations of heavy metals. Partially decomposed maize straw was a carbon source and stabilizing agent in the initial phase of bioreactor operation but later had to be supplemented by a soluble carbon source such as sodium lactate. The microbial community in the bioreactor was characterized by denaturing gradient gel electrophoresis (DGGE) and sequencing of partial 16S rDNA genes. Synergistic interaction between SRB (Desulfovibrio desulfuricans) and co-existing fermentative bacteria could be the key factor for the utilization of complex organic substrate (maize straw) as carbon and nutrients source for sulfate reduction. PMID:27058913

  4. Hydrated lime for metals immobilization and explosives transformation: Treatability study.

    PubMed

    Martin, W Andy; Larson, S L; Nestler, C C; Fabian, G; O'Connor, G; Felt, D R

    2012-05-15

    Fragmentation grenades contain Composition B (RDX and TNT) within a steel shell casing. There is the potential for off-site migration of high explosives and metals from hand grenade training ranges by transport in surface water and subsurface transport in leachate. This treatability study used bench-scale columns and mesocosm-scale laboratory lysimeters to investigate the potential of hydrated lime as a soil amendment for in situ remediation of explosives and metals stabilization in hand grenade range soils. Compared to the unamended soil there was a 26-92% reduction of RDX in the leachate and runoff water from the lime treated soils and a 66-83% reduction of zinc in the leachate and runoff water samples; where the hand grenade range metals of concern were zinc, iron, and manganese. The amended soil was maintained at the target pH of greater than 10.5 for optimum explosives decomposition. The treatability study indicated a high potential of success for scale-up to an in situ field study. PMID:22445717

  5. Evaluation and optimization of the metal-binding properties of a complex ligand for immobilized metal affinity chromatography.

    PubMed

    Chen, Bin; Li, Rong; Li, Shiyu; Chen, Xiaoli; Yang, Kaidi; Chen, Guoliang; Ma, Xiaoxun

    2016-02-01

    The simultaneous determination of two binding parameters for metal ions on an immobilized metal affinity chromatography column was performed by frontal chromatography. In this study, the binding parameters of Cu(2+) to l-glutamic acid were measured, the metal ion-binding characteristics of the complex ligand were evaluated. The linear correlation coefficients were all greater than 99%, and the relative standard deviations of two binding parameters were 0.58 and 0.059%, respectively. The experiments proved that the frontal chromatography method was accurate, reproducible, and could be used to determine the metal-binding parameters of the affinity column. The effects of buffer pH, type, and concentration on binding parameters were explored by uniform design experiment. Regression, matching and residual analyses of the models were performed. Meanwhile, the optimum-binding conditions of Cu(2+) on the l-glutamic acid-silica column were obtained. Under these binding conditions, observations and regression values of two parameters were similar, and the observation values were the best. The results demonstrated that high intensity metal affinity column could be effectively prepared by measuring and evaluating binding parameters using frontal chromatography combined with a uniform design experiment. The present work provided a new mode for evaluating and preparing immobilized metal affinity column with good metal-binding behaviors. PMID:26632098

  6. Purification of a Recombinant Polyhistidine-Tagged Glucosyltransferase Using Immobilized Metal-Affinity Chromatography (IMAC).

    PubMed

    de Costa, Fernanda; Barber, Carla J S; Pujara, Pareshkumar T; Reed, Darwin W; Covello, Patrick S

    2016-01-01

    Short peptide tags genetically fused to recombinant proteins have been widely used to facilitate detection or purification without the need to develop specific procedures. In general, an ideal affinity tag would allow the efficient purification of tagged proteins in high yield, without affecting its function. Here, we describe the purification steps to purify a recombinant polyhistidine-tagged glucosyltransferase from Centella asiatica using immobilized metal affinity chromatography. PMID:26843168

  7. Enhanced heavy metal immobilization in soil by grinding with addition of nanometallic Ca/CaO dispersion mixture.

    PubMed

    Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Kakeda, Mitsunori

    2012-10-01

    This study investigated the use of a nanometallic Ca and CaO dispersion mixture for the immobilization of heavy metals (As, Cd, Cr and Pb) in contaminated soil. Simple grinding achieved 85-90% heavy metal immobilization, but it can be enhanced further to 98-100% by addition of a nanometallic Ca/CaO dispersion mixture produced by grinding. Observations using SEM-EDS elemental maps and semi-quantitative analysis showed that the amounts of As, Cd, Cr, and Pb measurable on the soil particle surface decrease after nanometallic Ca/CaO treatment. The leachable heavy metal concentrations were reduced after nanometallic Ca/CaO treatment to concentrations lower than the Japan soil elution standard regulatory threshold: <0.01 mg L(-1) for As, Cd, and Pb; and 0.05 mg L(-1) for Cr. Effects of soil moisture and pH on heavy metal immobilization were not strongly influenced. The most probable mechanisms for the enhancement of heavy metal immobilization capacity with nanometallic Ca/CaO treatment might be due to adsorption and entrapment of heavy metals into newly formed aggregates, thereby prompting aggregation of soil particles and enclosure/binding with Ca/CaO-associated immobile salts. Results suggest that the nanometallic Ca/CaO mixture is suitable for use in immobilization of heavy-metal-contaminated soil under normal moisture conditions. PMID:22818089

  8. Immobilized Metal Affinity Chromatography Coupled to Multiple Reaction Monitoring Enables Reproducible Quantification of Phospho-signaling.

    PubMed

    Kennedy, Jacob J; Yan, Ping; Zhao, Lei; Ivey, Richard G; Voytovich, Uliana J; Moore, Heather D; Lin, Chenwei; Pogosova-Agadjanyan, Era L; Stirewalt, Derek L; Reding, Kerryn W; Whiteaker, Jeffrey R; Paulovich, Amanda G

    2016-02-01

    A major goal in cell signaling research is the quantification of phosphorylation pharmacodynamics following perturbations. Traditional methods of studying cellular phospho-signaling measure one analyte at a time with poor standardization, rendering them inadequate for interrogating network biology and contributing to the irreproducibility of preclinical research. In this study, we test the feasibility of circumventing these issues by coupling immobilized metal affinity chromatography (IMAC)-based enrichment of phosphopeptides with targeted, multiple reaction monitoring (MRM) mass spectrometry to achieve precise, specific, standardized, multiplex quantification of phospho-signaling responses. A multiplex immobilized metal affinity chromatography- multiple reaction monitoring assay targeting phospho-analytes responsive to DNA damage was configured, analytically characterized, and deployed to generate phospho-pharmacodynamic curves from primary and immortalized human cells experiencing genotoxic stress. The multiplexed assays demonstrated linear ranges of ≥3 orders of magnitude, median lower limit of quantification of 0.64 fmol on column, median intra-assay variability of 9.3%, median inter-assay variability of 12.7%, and median total CV of 16.0%. The multiplex immobilized metal affinity chromatography- multiple reaction monitoring assay enabled robust quantification of 107 DNA damage-responsive phosphosites from human cells following DNA damage. The assays have been made publicly available as a resource to the community. The approach is generally applicable, enabling wide interrogation of signaling networks. PMID:26621847

  9. Modified clay sorbents for wastewater treatment and immobilization of heavy metals in soils

    NASA Astrophysics Data System (ADS)

    Burlakovs, Juris; Klavins, Maris; Vincevica-Gaile, Zane; Stapkevica, Mara

    2014-05-01

    Soil and groundwater pollution with heavy metals is the result of both, anthropogenic and natural processes in the environment. Anthropogenic influence in great extent appears from industry, mining, treatment of metal ores and waste incineration. Contamination of soil and water can be induced by diffuse sources such as applications of agrochemicals and fertilizers in agriculture, air pollution from industry and transport, and by point sources, e.g., wastewater streams, runoff from dump sites and factories. Treatment processes used for metal removal from polluted soil and water include methodologies based on chemical precipitation, ion exchange, carbon adsorption, membrane filtration, adsorption and co-precipitation. Optimal removal of heavy metal ions from aqueous medium can be achieved by adsorption process which is considered as one of the most effective methods due to its cost-effectiveness and high efficiency. Immobilization of metals in contaminated soil also can be done with different adsorbents as the in situ technology. Use of natural and modified clay can be developed as one of the solutions in immobilization of lead, zinc, copper and other elements in polluted sites. Within the present study clay samples of different geological genesis were modified with sodium and calcium chlorides, iron oxyhydroxides and ammonium dihydrogen phosphate in variable proportions of Ca/P equimolar ratio to test and compare immobilization efficiency of metals by sorption and batch leaching tests. Sorption capacity for raw clay samples was considered as relatively lower referring to the modified species of the same clay type. In addition, clay samples were tested for powder X-ray difractometry, cation exchange, surface area properties, elemental composition, as well as scanning electron microscopy pictures of clay sample surface structures were obtained. Modified clay sorbents were tested for sorption of lead as monocontaminant and for complex contamination of heavy metals. The

  10. Kinetics of heavy metal uptake by vegetation immobilized in a polysulfone or polycarbonate polymeric matrix.

    PubMed

    Hardin, Ann M; Admassu, Wudneh

    2005-11-11

    The ability of four common vegetations - wood, grass, compost, and peat moss - to remove cadmium, chromium, and lead from dilute aqueous solutions is investigated. Dried ground vegetations are immobilized in polysulfone, and poly (bisphenyl A) carbonate to form spherical beads through a phase inversion process. The beads are contacted with a dilute aqueous solution containing metal ions of interest. The removal of metal ions from the solution is monitored over the course of the experiment and the first-order kinetics parameters estimated. The rates of removal as well as the equilibrium bead loadings are shown to be affected by both the choice of vegetation and the choice of polymer. PMID:16051434

  11. Immobilization of heavy metals by calcium sulfoaluminate cement

    SciTech Connect

    Peysson, S.; Pera, J. . E-mail: Jean.Pera@insa-lyon.fr; Chabannet, M.

    2005-12-15

    Two types of calcium sulfoaluminate cement containing 20% and 30% phosphogypsum, respectively, were investigated for their ability in hazardous waste stabilization. Fourteen series of pastes were prepared, each containing the following soluble salt: Na{sub 2}CrO{sub 4}.4H{sub 2}O; Na{sub 2}Cr{sub 2}O{sub 7}.2H{sub 2}O; CrCl{sub 3}.6H{sub 2}O; Pb(NO{sub 3}){sub 2}; Zn(NO{sub 3}){sub 2}.6H{sub 2}O; ZnSO{sub 4}.7H{sub 2}O; and CdCl{sub 2}.5H2O. The level of pollution was 0.069 mol of heavy metal per Kg of cement. The study has been carried out by means of X-ray diffraction, thermal analysis, scanning electron microscopy, mercury intrusion porosimetry, electrical conductivity, and leaching tests. Very good retention of lead, cadmium, zinc and trivalent chromium is observed. The retention of hexavalent chromium depends upon the nature of the binder: the cement containing 20% gypsum develops the best behaviour. This is explained by the microstructure of the hydrated paste: in the paste containing 30% gypsum, delayed ettringite precipitates and damages the hardened paste.

  12. A nex immobilized hydroxypyridinone as a sequestering agent for heavy metal ions

    NASA Astrophysics Data System (ADS)

    Santos, M. A.; Grazina, R.

    2003-05-01

    New chelating solid matrices were developed for the removal of hard heavy metal ions (ex: Fe^{3+}, Al^{3+}. Pu^{4+}) from water solutions. They are based on the immobilization of 3-hydroxy-4-pyridinone (HP) amino-derivatives by covalent binding to epoxy-activated Sepharose gels, through amine linkages. These HP-functionalized gels are able to strongly chelate those metal ions though formation of 1:1 (metal: HP) complexes. They possess a much higher stability and capacity for sequestering this type of metal ions and in a wider range of pH than the corresponding analogous gels, which involve the CNBr-activated sepharose and have amide/isoureia bonds as the ligand-matrix points of attachment.

  13. Immobilization of heavy metals (Pb, Cu, Cr, Zn, Cd, Mn) in the mineral additions containing concrete composites.

    PubMed

    Giergiczny, Zbigniew; Król, Anna

    2008-12-30

    The presented work determines the level of heavy metals (Pb+2, Cu+2, Zn+2, Cr+6, Cd+2, Mn+2) immobilization in the composites produced using Ordinary Portland Cement (OPC) as well as of binders containing large amount of mineral additives in its composition-siliceous fly ash (FA), fluidized bed combustion ash (FFA) and ground granulated blast furnace slag (GGBFS). Heavy metals were introduced to cementitious materials in the form of soluble salts as well as components of hazardous wastes (medical ash, metallurgical dust). It has been stated, that the level of heavy metals immobilization is combined with composites composition. Majority of analyzed heavy metals, added to binders' composition in the form of heavy metal salts achieves high level of immobilization, in mortar based on binder with 85% GGBFS and 15% OPC. The lowest immobilization level was reached for chromium Cr+6 added to hardening mortars as Na2Cr2O72H2O. The level ranges from 85.97% in mortars made on blended binder (20% OPC, 30% FFA and 50% GGBFS) to 93.33% in mortar produced on OPC. The increase of the so-called immobilization degree with time of hardened material maturing was found. This should be attributed to the pozzolanic or pozzolanic/hydraulic properties of components used; their effect on microstructure of hardened material is also important. Mineral additions enter the hydration reactions in the mixtures and favor the formation of specific microstructure promoting the immobilization of hazardous elements. PMID:18423859

  14. Hydrophilic polydopamine-coated graphene for metal ion immobilization as a novel immobilized metal ion affinity chromatography platform for phosphoproteome analysis.

    PubMed

    Yan, Yinghua; Zheng, Zhifang; Deng, Chunhui; Li, Yan; Zhang, Xiangmin; Yang, Pengyuan

    2013-09-17

    To discover trace phosphorylated proteins or peptides with great biological significance for in-depth phosphoproteome analysis, it is urgent to develop a novel technique for highly selective and effective enrichment of phosphopeptides. In this work, an IMAC (immobilized metal ion affinity chromatography) material with polydopamine coated on the surface of graphene and functionalized with titanium ions (denoted as Ti(4+)-G@PD) was initially designed and synthesized. The newly prepared Ti(4+)-G@PD with enhanced hydrophilicity and biological compatibility was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and infrared (IR), and its performance for selective and effective enrichment of phosphopeptide was evaluated with both standard peptide mixtures and human serum. PMID:23941301

  15. Metal-organic framework-immobilized polyhedral metal nanocrystals: reduction at solid-gas interface, metal segregation, core-shell structure, and high catalytic activity.

    PubMed

    Aijaz, Arshad; Akita, Tomoki; Tsumori, Nobuko; Xu, Qiang

    2013-11-01

    For the first time, this work presents surfactant-free monometallic and bimetallic polyhedral metal nanocrystals (MNCs) immobilized to a metal-organic framework (MIL-101) by CO-directed reduction of metal precursors at the solid-gas interface. With this novel method, Pt cubes and Pd tetrahedra were formed by CO preferential bindings on their (100) and (111) facets, respectively. PtPd bimetallic nanocrystals showed metal segregation, leading to Pd-rich core and Pt-rich shell. Core-shell Pt@Pd nanocrystals were immobilized to MIL-101 by seed-mediated two-step reduction, representing the first example of core-shell MNCs formed using only gas-phase reducing agents. These MOF-supported MNCs exhibited high catalytic activities for CO oxidation. PMID:24138338

  16. Heavy metal-immobilizing organoclay facilitates polycyclic aromatic hydrocarbon biodegradation in mixed-contaminated soil.

    PubMed

    Biswas, Bhabananda; Sarkar, Binoy; Mandal, Asit; Naidu, Ravi

    2015-11-15

    Soils contaminated with a mixture of heavy metals and polycyclic aromatic hydrocarbons (PAHs) pose toxic metal stress to native PAH-degrading microorganisms. Adsorbents such as clay and modified clay minerals can bind the metal and reduce its toxicity to microorganisms. However, in a mixed-contaminated soil, an adsorption process more specific to the metals without affecting the bioavailability of PAHs is desired for effective degradation. Furthermore, the adsorbent should enhance the viability of PAH-degrading microorganisms. A metal-immobilizing organoclay (Arquad(®) 2HT-75-bentonite treated with palmitic acid) (MIOC) able to reduce metal (cadmium (Cd)) toxicity and enhance PAH (phenanthrene) biodegradation was developed and characterized in this study. The MIOC differed considerably from the parent clay in terms of its ability to reduce metal toxicity (MIOC>unmodified bentonite>Arquad-bentonite). The MIOC variably increased the microbial count (10-43%) as well as activities (respiration 3-44%; enzymatic activities up to 68%), and simultaneously maintained phenanthrene in bioavailable form in a Cd-phenanthrene mixed-contaminated soil over a 21-day incubation period. This study may lead to a new MIOC-assisted bioremediation technique for PAHs in mixed-contaminated soils. PMID:26022853

  17. Immobilized metal ion affinity partitioning, a method combining metal-protein interaction and partitioning of proteins in aqueous two-phase systems.

    PubMed

    Birkenmeier, G; Vijayalakshmi, M A; Stigbrand, T; Kopperschläger, G

    1991-02-22

    Immobilized metal ions were used for the affinity extraction of proteins in aqueous two-phase systems composed of polyethylene glycol (PEG) and dextran or PEG and salt. Soluble chelating polymers were prepared by covalent attachment of metal-chelating groups to PEG. The effect on the partitioning of proteins of such chelating PEG derivatives coordinated with different metal ions is demonstrated. The proteins studied were alpha 2-macroglobulin, tissue plasminogen activator, superoxide dismutase and monoclonal antibodies. The results indicate that immobilized metal ion affinity partitioning provides excellent potential for the extraction of proteins. PMID:1710621

  18. NMR imaging of heavy metal absorption in alginate, immobilized cells, and kombu algal biosorbents.

    PubMed

    Nestle, N F; Kimmich, R

    1996-09-01

    In this contribution, an NMR imaging study of heavy metal absorption in alginate, immobilized-cell biosorbents, and kombu (Laminaria japonica) algal biomass is presented. This method provides the good possibility of directly monitoring the time evolution of the spatial distribution of the ions in the materials. From these results, we demonstrate that rare earth ions are absorbed with a steep reaction front that can be described very well with a modified shrinking core model, while copper ions are absorbed with a more diffuse front. PMID:18629817

  19. Single-step purification of native miraculin using immobilized metal-affinity chromatography.

    PubMed

    Duhita, Narendra; Hiwasa-Tanase, Kyoko; Yoshida, Shigeki; Ezura, Hiroshi

    2009-06-24

    Miraculin is a taste-modifying protein that can be isolated from miracle fruit ( Richadella dulcifica ), a shrub native to West Africa. It is able to turn a sour taste into a sweet taste. The commercial exploitation of this sweetness-modifying protein is underway, and a fast and efficient purification method to extract the protein is needed. We succeeded in purifying miraculin from miracle fruit in a single-step purification using immobilized metal-affinity chromatography (IMAC). The purified miraculin exhibited high purity (>95%) in reverse-phase high-performance liquid chromatography. We also demonstrated the necessity of its structure for binding to the nickel-IMAC column. PMID:19469504

  20. TOXIC METALS IN THE ENVIRONMENT: THERMODYNAMIC CONSIDERATIONS FOR POSSIBLE IMMOBILIZATION STRATEGIES FOR PB, CD, AS, AND HG

    EPA Science Inventory

    The contamination of soils by toxic metals is a widespread, serious problem that demands immediate action either by removal or immobilization, which is defined as a process which puts the metal into a chemical form, probably as a mineral, which will be inert and highly insoluble ...

  1. Immobilization of heavy metals in electroplating sludge by biochar and iron sulfide.

    PubMed

    Lyu, Honghong; Gong, Yanyan; Tang, Jingcshun; Huang, Yao; Wang, Qilin

    2016-07-01

    Electroplating sludge (ES) containing large quantities of heavy metals is regarded as a hazardous waste in China. This paper introduced a simple method of treating ES using environmentally friendly fixatives biochar (BC) and iron sulfide (FeS), respectively. After 3 days of treatment with FeS at a FeS-to-ES mass ratio of 1:5, the toxicity characteristic leaching procedure (TCLP)-based leachability of total Cr (TCr), Cu(II), Ni(II), Pb(II), and Zn(II) was decreased by 59.6, 100, 63.8, 73.5, and 90.5 %, respectively. After 5 days of treatment with BC at a BC-to-ES mass ratio of 1:2, the TCLP-based leachability was declined by 35.1, 30.6, 22.3, 23.1, and 22.4 %, respectively. Pseudo first-order kinetic model adequately simulated the sorption kinetic data. Structure and morphology analysis showed that adsorption, electrostatic attraction, surface complexation, and chemical precipitation were dominant mechanisms for heavy metals immobilization by BC, and that chemical precipitation (formation of metal sulfide and hydroxide precipitates), iron exchange (formation of CuFeS2), and surface complexation were mainly responsible for heavy metals removal by FeS. Economic costs of BC and FeS were 500 and 768 CNY/t, lower than that of Na2S (940 CNY/t). The results suggest that BC and FeS are effective, economic, and environmentally friendly fixatives for immobilization of heavy metals in ES before landfill disposal. PMID:27068904

  2. Novel synthesis and applications of Thiomer solidification for heavy metals immobilization in hazardous ASR/ISW thermal residue.

    PubMed

    Baek, Jin Woong; Mallampati, Srinivasa Reddy; Park, Hung Suck

    2016-03-01

    The present paper reports the novel synthesis and application of Thiomer solidification for heavy metal immobilization in hazardous automobile shredder residues and industrial solid waste (ASR/ISW) thermal residues. The word Thiomer is a combination of the prefix of a sulfur-containing compound "Thio" and the suffix of "Polymer" meaning a large molecule compound of many repeated subunits. To immobilize heavy metals, either ASR/ISW thermal residues (including bottom and fly ash) was mixed well with Thiomer and heated at 140°C. After Thiomer solidification, approximately 91-100% heavy metal immobilization was achieved. The morphology and mineral phases of the Thiomer-solidified ASR/ISW thermal residue were characterized by field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction (XRD), which indicated that the amounts of heavy metals detectable on the ASR/ISW thermal residue surface decreased and the sulfur mass percent increased. XRD indicated that the main fraction of the enclosed/bound materials on the ASR/ISW residue contained sulfur associated crystalline complexes. The Thiomer solidified process could convert the heavy metal compounds into highly insoluble metal sulfides and simultaneously encapsulate the ASR/ISW thermal residue. These results show that the proposed method can be applied to the immobilization of ASR/ISW hazardous ash involving heavy metals. PMID:26777552

  3. Competitive immobilization of Pb in an aqueous ternary-metals system by soluble phosphates with varying pH.

    PubMed

    Zhang, Zhuo; Ren, Jie; Wang, Mei; Song, Xinlai; Zhang, Chao; Chen, Jiayu; Li, Fasheng; Guo, Guanlin

    2016-09-01

    Chemical immobilization by phosphates has been widely and successfully applied to treat Pb in wastewater and contaminated soils. Pb in wastewaters and soils, however, always coexists with other heavy metals and their competitive reactions with phosphates have not been quantitatively and systematically studied. In this approach, immobilization of Pb, Zn, and Cd by mono-, di-, and tripotassium phosphate (KH2PO4, K2HPO4, and K3PO4) was observed in the single- and ternary-metals solutions. The immobilization rates of the three metals were determined by the residual concentration. The mineral composition and structure of the precipitates were characterized by powder X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). The results indicated that competitive reaction occurred in Pb-Zn-Cd ternary system, with immobilization rates decrease of <3.6%, <78%, and <89% for Pb, Zn and Cd (molar ratios of P: metal <1), respectively, compared to single metal system. The reaction of Pb with three phosphates exhibited intense competitiveness and the phosphates had a stronger affinity for Pb when Cl(-) was added. Pb-phosphate minerals formed by KH2PO4 with the better crystalline characteristics and largest size were very stable with a low dissolution rate (<0.02%) in the solution of pH 2.88, compared to K2HPO4 and K3PO4. This study demonstrated that Pb could be firstly and effectively immobilized by phosphates in multi-metal solutions containing Pb, Zn and Cd. Moreover, the research provided the insight of the importance of phosphate with low pH (e.g. KH2PO4) and the presence of Cl(-) for more efficient immobilization of Pb in the multi-metals pollution system. PMID:27276163

  4. Heavy metal immobilization in soil near abandoned mines using eggshell waste and rapeseed residue.

    PubMed

    Lee, Sang Soo; Lim, Jung Eun; El-Azeem, Samy A M Abd; Choi, Bongsu; Oh, Sang-Eun; Moon, Deok Hyun; Ok, Yong Sik

    2013-03-01

    Heavy metal contamination of agricultural soils has received great concern due to potential risk to human health. Cadmium and Pb are largely released from abandoned or closed mines in Korea, resulting in soil contamination. The objective of this study was to evaluate the effects of eggshell waste in combination with the conventional nitrogen, phosphorous, and potassium fertilizer (also known as NPK fertilizer) or the rapeseed residue on immobilization of Cd and Pb in the rice paddy soil. Cadmium and Pb extractabilities were tested using two methods of (1) the toxicity characteristics leaching procedure (TCLP) and (2) the 0.1 M HCl extraction. With 5 % eggshell addition, the values of soil pH were increased from 6.33 and 6.51 to 8.15 and 8.04 in combination with NPK fertilizer and rapeseed residue, respectively, compared to no eggshell addition. The increase in soil pH may contribute to heavy metal immobilization by altering heavy metals into more stable in soils. Concentrations of TCLP-extracted Cd and Pb were reduced by up to 67.9 and 93.2 % by addition of 5 % eggshell compared to control. For 0.1 M HCl extraction method, the concentration of 0.1 M HCl-Cd in soils treated with NPK fertilizer and rapeseed residue was significantly reduced by up to 34.01 and 46.1 %, respectively, with 5 % eggshell addition compared to control. A decrease in acid phosphatase activity and an increase in alkaline phosphatase activity at high soil pH were also observed. Combined application of eggshell waste and rapeseed residue can be cost-effective and beneficial way to remediate the soil contaminated with heavy metals. PMID:22864756

  5. Geopolymers with a high percentage of bottom ash for solidification/immobilization of different toxic metals.

    PubMed

    Boca Santa, Rozineide A Antunes; Soares, Cíntia; Riella, Humberto Gracher

    2016-11-15

    Geopolymers are produced using alkali-activated aluminosilicates, either as waste or natural material obtained from various sources. This study synthesized geopolymers from bottom ash and metakaolin (BA/M) in a 2:1wt ratio to test the solidification/immobilization (S/I) properties of heavy metals in geopolymer matrices, since there is very little research using BA in this type of matrices. Therefore, a decision was made to use more than 65% of BA in geopolymer synthesis with and without the addition of heavy metals. The S/I tests with metals used 10, 15 and 30ml of a waste solution after pickling of printed circuit boards containing metals, including Pb, Cr, Cu, Fe, Sn, As and Ni, in different proportions. As alkali activator, the NaOH and KOH were used in the concentrations of 8 and 12M in the composition of Na2SiO3 in 1:2vol ratios. To test S/I efficiency, tests were conducted to obtain the leached and solubilized extract. The analysis was carried out through X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Scanning Electron Microscope (SEM), Energy-Dispersive X-Ray Spectroscopy (EDS) and compressive strength tests. The geopolymer showed a high degree of S/I of the metals; in some samples, the results reached nearly 100%. PMID:27420386

  6. Biosorption of metal contaminants using immobilized biomass: Field studies. Report of Investigations/1993

    SciTech Connect

    Jeffers, T.H.; Bennett, P.G.; Corwin, R.R.

    1993-01-01

    The U.S. Bureau of Mines has developed porous beads containing immobilized biological materials such as sphagnum peat moss for extracting metal contaminants from waste waters. The beads, designated as BIO-FIX beads, have removed toxic metals from over 100 waters in laboratory tests. These waters include acid mine drainage (AMD) water from mining sites, metallurgical and chemical industry waste water, and contaminated ground water. Following the laboratory studies, cooperative field tests were conducted to evaluate the metal adsorption properties of the beads in column and low-maintenance circuits, determine bead stability in varied climatic situations, and demonstrate the beads' potential as a viable waste water treatment technique. Field results indicated that BIO-FIX beads readily adsorbed cadmium, lead, and other toxic metals from dilute waters; effluents frequently met drinking water standards and other discharge criteria. The beads exhibited excellent handling characteristics in both column and low-maintenance circuits, and continued to extract metal ions after repeated loading-elution cycles.

  7. Catalytic properties of endoxylanase fusion proteins from Neocallimastix frontalis and effect of immobilization onto metal-chelate matrix.

    PubMed

    Mesta, Laurent; Heyraud, Alain; Joseleau, Jean Paul; Coulet, Pierre R

    2003-03-20

    The production of hybrid enzymes with novel properties and the research for new methods for enzyme immobilization in bioreactors are of major interest in biotechnology. We report here the second part of a study concerning the improvement of the properties of the endoxylanase XYN3A4 from the anaerobic fungi Neocallimastix frontalis. The effects of gene fusion and immobilization on metal-chelate matrix are also compared for the reference enzymes XYN3, XYN3A, XYN4 used for the construction of the fusion protein XYN3A4. The influence of the metal ion in the immobilization process was first investigated and best immobilization yields were obtained with the Cu(II) ion whereas best coupling efficiencies were reached with the Ni(II) ion. It was also observed that XYN3, XYN3A and XYN34 had a lower rate of hydrolysis when immobilized on Ni(II)-IDA and more difficulties to accomodate small substrates than the soluble enzymes. Nevertheless, a major difference was noted during the hydrolysis of birchwood xylan and it appears that the reaction using the immobilized XYN3A4 chimeric enzyme leads to the accumulation of a specific product. PMID:12615394

  8. Immobilizing highly catalytically active Pt nanoparticles inside the pores of metal-organic framework: a double solvents approach.

    PubMed

    Aijaz, Arshad; Karkamkar, Abhi; Choi, Young Joon; Tsumori, Nobuko; Rönnebro, Ewa; Autrey, Tom; Shioyama, Hiroshi; Xu, Qiang

    2012-08-29

    Ultrafine Pt nanoparticles were successfully immobilized inside the pores of a metal-organic framework, MIL-101, without aggregation of Pt nanoparticles on the external surfaces of framework by using a "double solvents" method. TEM and electron tomographic measurements clearly demonstrated the uniform three-dimensional distribution of the ultrafine Pt NPs throughout the interior cavities of MIL-101. The resulting Pt@MIL-101 composites represent the first highly active MOF-immobilized metal nanocatalysts for catalytic reactions in all three phases: liquid-phase ammonia borane hydrolysis, solid-phase ammonia borane thermal dehydrogenation, and gas-phase CO oxidation. PMID:22888976

  9. Immobilization of Radionuclides and Heavy Metals through Anaerobic Bio-Oxidation of Fe(II)

    PubMed Central

    Lack, Joseph G.; Chaudhuri, Swades K.; Kelly, Shelly D.; Kemner, Kenneth M.; O'Connor, Susan M.; Coates, John D.

    2002-01-01

    Adsorption of heavy metals and radionuclides (HMR) onto iron and manganese oxides has long been recognized as an important reaction for the immobilization of these compounds. However, in environments containing elevated concentrations of these HMR the adsorptive capacity of the iron and manganese oxides may well be exceeded, and the HMR can migrate as soluble compounds in aqueous systems. Here we demonstrate the potential of a bioremediative strategy for HMR stabilization in reducing environments based on the recently described anaerobic nitrate-dependent Fe(II) oxidation by Dechlorosoma species. Bio-oxidation of 10 mM Fe(II) and precipitation of Fe(III) oxides by these organisms resulted in rapid adsorption and removal of 55 μM uranium and 81 μM cobalt from solution. The adsorptive capacity of the biogenic Fe(III) oxides was lower than that of abiotically produced Fe(III) oxides (100 μM for both metals), which may have been a result of steric hindrance by the microbial cells on the iron oxide surfaces. The binding capacity of the biogenic oxides for different heavy metals was indirectly correlated to the atomic radius of the bound element. X-ray absorption spectroscopy indicated that the uranium was bound to the biogenically produced Fe(III) oxides as U(VI) and that the U(VI) formed bidentate and tridentate inner-sphere complexes with the Fe(III) oxide surfaces. Dechlorosoma suillum oxidation was specific for Fe(II), and the organism did not enzymatically oxidize U(IV) or Co(II). Small amounts (less than 2.5 μM) of Cr(III) were reoxidized by D. suillum; however, this appeared to be inversely dependent on the initial concentration of the Cr(III). The results of this study demonstrate the potential of this novel approach for stabilization and immobilization of HMR in the environment. PMID:12039723

  10. The role of biochar, natural iron oxides, and nanomaterials as soil amendments for immobilizing metals in shooting range soil.

    PubMed

    Rajapaksha, Anushka Upamali; Ahmad, Mahtab; Vithanage, Meththika; Kim, Kwon-Rae; Chang, Jun Young; Lee, Sang Soo; Ok, Yong Sik

    2015-12-01

    High concentration of toxic metals in military shooting range soils poses a significant environmental concern due to the potential release of metals, such as Pb, Cu, and Sb, and hence requires remediation. The current study examined the effectiveness of buffalo weed (Ambrosia trifida L.) biomass and its derived biochars at pyrolytic temperatures of 300 and 700 °C, natural iron oxides (NRE), gibbsite, and silver nanoparticles on metal immobilization together with soil quality after 1-year soil incubation. Destructive (e.g., chemical extractions) and non-destructive (e.g., molecular spectroscopy) methods were used to investigate the immobilization efficacy of each amendment on Pb, Cu, and Sb, and to explore the possible immobilization mechanisms. The highest immobilization efficacy was observed with biochar produced at 300 °C, showing the maximum decreases of bioavailability by 94 and 70% for Pb and Cu, respectively, which were attributed to the abundance of functional groups in the biochar. Biochar significantly increased the soil pH, cation exchange capacity, and P contents. Indeed, the scanning electron microscopic elemental dot mapping and X-ray absorption fine structure spectroscopic (EXAFS) studies revealed associations of Pb with P (i.e., the formation of stable chloropyromorphite [Pb5(PO4)3Cl]) in the biomass- or biochar-amended soils. However, no amendment was effective on Sb immobilization. PMID:25794596

  11. Mathematically modeling the removal of heavy metals from a wastewater using immobilized biomass

    SciTech Connect

    Trujillo, E.M. ); Jeffers, T.H.; Ferguson, C.; Stevenson, H.Q. )

    1991-09-01

    A technique developed by the US Bureau of Mines using biomass, sphagnum peat moss, immobilized in porous polysulfone beads selectively removed Zn, Cd, and other metals from a zinc mining wastewater to concentrations well below the National Drinking Water Standards. The objective of this paper was to obtain experimental data on the biosorption of several heavy metals onto the beads containing sphagnum peat moss and to develop the appropriate mathematical models that might be used to describe the multicomponent phenomena. Nonequilibrium multicomponent mathematical models were developed and experimental data obtained for the simultaneous, competitive adsorption of six metal ions from an actual wastewater for both batch kinetic and semicontinuous packed-bed experiments. Experimental results indicated a selectivity order of Al > Cd > Zn > Ca > Mn > Mg and that metal ion breakthroughs were quite sensitive to ionic concentrations and adsorptive capacity. In addition, it was observed that, for the packed-bed experiments, the adsorptive capacity of the beads appeared to increase after the first few cycles. Mathematical models provided effective multicomponent equilibrium constants, adsorptive capacities, and reduced overall mass-transfer coefficients. The constants obtained from the packed-bed model were in reasonable agreement with those obtained from the batch kinetic model.

  12. A novel matrix derivatized from hydrophilic gigaporous polystyrene-based microspheres for high-speed immobilized-metal affinity chromatography.

    PubMed

    Qu, Jian-Bo; Huang, Yong-Dong; Jing, Guang-Lun; Liu, Jian-Guo; Zhou, Wei-Qing; Zhu, Hu; Lu, Jian-Ren

    2011-05-01

    Agarose coated gigaporous polystyrene microspheres were evaluated as a novel matrix for immobilized-metal affinity chromatography (IMAC). With four steps, nickel ions were successfully immobilized on the microspheres. The gigaporous structure and chromatographic properties of IMAC medium were characterized. A column packed with the matrix showed low column backpressure and high column efficiency at high flow velocity. Furthermore, this matrix was used for purifying superoxide dismutase (SOD), which was expressed in Escherichia coli (E. coli) in submerged fermentation, on an Äkta purifier 100 system under different flow velocities. The purity of the SOD from this one-step purification was 79% and the recovery yield was about 89.6% under the superficial flow velocity of 3251 cm/h. In conclusion, all the results suggested that the gigaporous matrix has considerable advantages for high-speed immobilized-metal affinity chromatography. PMID:21454141

  13. Evaluation of potential for reuse of industrial wastewater using metal-immobilized catalysts and reverse osmosis.

    PubMed

    Choi, Jeongyun; Chung, Jinwook

    2015-04-01

    This report describes a novel technology of reusing the wastewater discharged from the display manufacturing industry through an advanced oxidation process (AOP) with a metal-immobilized catalyst and reverse osmosis (RO) in the pilot scale. The reclaimed water generated from the etching and cleaning processes in display manufacturing facilities was low-strength organic wastewater and was required to be recycled to secure a water source. For the reuse of reclaimed water to ultrapure water (UPW), a combination of solid-phase AOP and RO was implemented. The removal efficiency of TOC by solid-phase AOP and RO was 92%. Specifically, the optimal acid, pH, and H2O2 concentrations in the solid-phase AOP were determined. With regard to water quality and operating costs, the combination of solid-phase AOP and RO was superior to activated carbon/RO and ultraviolet AOP/anion polisher/coal carbon. PMID:25548034

  14. Ni2+-based immobilized metal ion affinity chromatography of lactose operon repressor protein from Escherichia coli.

    PubMed

    Velkov, Tony; Jones, Alun; Lim, Maria L R

    2008-01-01

    A two-step chromatographic sequence is described for the purification of native lactose operon repressor protein from Escherichia coli cells. The first step involves Ni(2+)-based immobilized metal ion affinity chromatography of the soluble cytoplasmic extract. This method provides superior speed, resolution and yield than the established phosphocellulose cation-exchange chromatographic procedure. Anion-exchange chromatography is used for further purification to >95% purity. The identity and purity of the lactose repressor protein were demonstrated using sodium dodecylsulphate polyacrylamide electrophoresis, crystallization, tryptic finger-printing mass spectrometry, and inducer binding assays. The purified lac repressor exhibited inducer sensitivity for operator DNA binding and undergoes a conformational change upon inducer binding. By all these extensive biochemical criteria, the purified protein behaves exactly as that described for the Escherichia coli lactose operon repressor. PMID:18800304

  15. Preparation of a novel Zr(4+)-immobilized metal affinity membrane for selective adsorption of phosphoprotein.

    PubMed

    He, Maofang; Wang, Chaozhan; Wei, Yinmao

    2016-09-01

    In this study, a novel phosphate-Zr(4+) immobilized metal affinity membrane (IMAM) was prepared based on the surface initiated-atom transfer radical polymerization technique for the selective adsorption of phosphoprotein. The adsorption capacity and selectivity of the phosphate-Zr(4+) IMAM were evaluated by using the mixture of standard phosphoproteins (β-casein, ovalbumin) and nonphosphoproteins (bovine serum albumin and lysozyme) as model samples. The adsorption isotherms and competitive adsorption results demonstrated that the phosphate-Zr(4+) IMAM had higher binding capacity and selectivity for phosphoproteins over nonphosphoproteins. Moreover, the phosphate-Zr(4+) IMAM exhibited good re-usability and re-productivity. Finally, the phosphate-Zr(4+) IMAM was applied to separate phosphoprotein from real samples with high purity. Therefore, the as-prepared phosphate-Zr(4+) IMAM could be a promising affinity material for the efficient enrichment of phosphoprotein from complex bio-samples. PMID:27433983

  16. Localization of heavy metals immobilized on specific organic and mineral parts of a wood-derived biochar

    NASA Astrophysics Data System (ADS)

    Rees, Frédéric; Watteau, Françoise; Morel, Jean-Louis

    2013-04-01

    Biochar has been intensively investigated over recent years, not only as a promising carbon sequestration or fertilizing agent in soils but also as a possible new sorbent to remediate contaminated soils. A few studies have revealed its high potential for heavy metals immobilization depending on the nature of biochar and trace elements. The mechanisms behind this immobilization remain however unclear: some authors have hypothesized a high sorption capacity due to biochar large surface area while others have suggested that this immobilization is mainly due to soil pH increase. In particular, the distinction between heavy metals specific sorption in biochar pores and heavy metals precipitation in or outside biochar particles is often impossible to make while it is of primary importance to evaluate biochar ability to retain these pollutants on a long-time scale. In order to evaluate the main heavy metal immobilization effects on a standard biochar and to identify the most successful biochar parts of the sample, we examined biochar particles after heavy metals immobilization in batch experiments designed to mimic real chemical processes in soils. A biochar derived from hard and soft wood and pyrolyzed at about 450°C was put in contact with relatively low concentrations of heavy metals (Pb, Cu, Cd, Zn, Ni) in an initially acidic Ca(NO3)2 solution. Following a one-week adsorption and a one-week desorption step, we recovered the biochar particles and observed them using scanning electron microscopy coupled to energy dispersive x-ray spectroscopy, focusing especially on the changes in mineral phases and the location of each of the retained heavy metals on biochar particles. We were able to distinguish different structures in the biochar samples which were linked to the degree of pyrolysis and the exact nature of the raw wood biomass. We detected the presence of concentrated metals zones (e.g. lead) in specific locations of the organic particles depending on the original

  17. A metal-organic framework with immobilized Ag(i) for highly efficient desulfurization of liquid fuels.

    PubMed

    Huang, Minhui; Chang, Ganggang; Su, Ye; Xing, Huabin; Zhang, Zhiguo; Yang, Yiwen; Ren, Qilong; Bao, Zongbi; Chen, Banglin

    2015-08-01

    A metal-organic framework immobilized with Ag(i) sites, namely, (Cr)-MIL-101-SO3Ag, was successfully developed as a highly efficient desulfurization adsorbent because of the strong binding of these Ag(i) sites for thiophene derivatives. PMID:26136210

  18. Immobilizing metal nanoparticles to metal-organic frameworks with size and location control for optimizing catalytic performance.

    PubMed

    Zhu, Qi-Long; Li, Jun; Xu, Qiang

    2013-07-17

    AuNi alloy nanoparticles were successfully immobilized to MIL-101 with size and location control for the first time by double solvents method (DSM) combined with a liquid-phase concentration-controlled reduction strategy. When an overwhelming reduction approach was employed, the uniform 3D distribution of the ultrafine AuNi nanoparticles (NPs) encapsulated in the pores of MIL-101 was achieved, as demonstrated by TEM and electron tomographic measurements, which brings light to new opportunities in the fabrication of ultrafine non-noble metal-based NPs throughout the interior pores of MOFs. The ultrafine AuNi alloy NPs inside the mesoporous MIL-101 exerted exceedingly high activity for hydrogen generation from the catalytic hydrolysis of ammonia borane. PMID:23805877

  19. Ameliorants to immobilize Cd in rice paddy soils contaminated by abandoned metal mines in Korea.

    PubMed

    Ok, Yong Sik; Kim, Sung-Chul; Kim, Dong-Kuk; Skousen, Jeffrey G; Lee, Jin-Soo; Cheong, Young-Wook; Kim, Su-Jung; Yang, Jae E

    2011-01-01

    The cadmium (Cd) content of rice grain grown in metal-contaminated paddy soils near abandoned metal mines in South Korea was found to exceed safety guidelines (0.2 mg Cd kg⁻¹) set by the Korea Food and Drug Administration (KFDA). However, current remediation technologies for heavy metal-contaminated soils have limited application with respect to rice paddy soils. Laboratory and greenhouse experiments were conducted to assess the effects of amending contaminated rice paddy soils with zerovalent iron (ZVI), lime, humus, compost, and combinations of these compounds to immobilize Cd and inhibit Cd translocation to rice grain. Sequential extraction analysis revealed that treatment with the ameliorants induced a 50-90% decrease in the bioavailable Cd fractions when compared to the untreated control soil. When compared to the control, Cd uptake by rice was decreased in response to treatment with ZVI + humus (69%), lime (65%), ZVI + compost (61%), compost (46%), ZVI (42%), and humus (14%). In addition, ameliorants did not influence rice yield when compared to that of the control. Overall, the results of this study indicated that remediation technologies using ameliorants effectively reduce Cd bioavailability and uptake in contaminated rice paddy soils. PMID:21052787

  20. Immobilized metal affinity chromatography without chelating ligands: purification of soybean trypsin inhibitor on zinc alginate beads.

    PubMed

    Gupta, Munishwar N; Jain, Sulakshana; Roy, Ipsita

    2002-01-01

    Immobilized metal affinity chromatography (IMAC) is a widely used technique for bioseparation of proteins in general and recombinant proteins with polyhistidine fusion tags in particular. An expensive and critical step in this process is coupling of a chelating ligand to the chromatographic matrix. This chelating ligand coordinates metal ions such as Cu(2+), Zn(2+), and Ni(2+), which in turn bind proteins. The toxicity of chemicals required for coupling and their slow release during the separation process are of considerable concern. This is an important issue in the context of purification of proteins/enzymes which are used in food processing or pharmaceutical purposes. In this work, a simpler IMAC design is described which should lead to a paradigm shift in the application of IMAC in separation. It is shown that zinc alginate beads (formed by chelating alginate with Zn(2+) directly) can be used for IMAC. As "proof of concept", soybean trypsin inhibitor was purified 18-fold from its crude extract with 90% recovery of biological activity. The dynamic binding capacity of the packed bed was 3919 U mL(-1), as determined by frontal analysis. The media could be regenerated with 8 M urea and reused five times without any appreciable loss in its binding capacity. PMID:11822903

  1. Heavy metal immobilization during the codisposal of municipal solid waste bottom ash and wastewater sludges

    SciTech Connect

    Eighmy, T.T.; Guay, M.A.; McHugh, S.; Kinner, N.E.; Ballestero, T.P. )

    1988-01-01

    One of the problems attendant to the incineration of municipal solid waste (MSW) is the siting and design of secure landfills to receive combustion residues from the incineration process. The authors have completed a study for a solid waste cooperative that was interested in codisposing MSW bottom ash and wastewater sludges. This codisposal scheme was initiated to address severe ash disposal problems within the Lamprey Regional Solid Waste Cooperative, and a severe sludge disposal problem in the City of Somersworth, NH, a member of the Cooperative and host city to the proposed codisposal site. The design of the landfill indicated that mixtures of bottom ash and combined sludges would range between 10:1 and 5:1 (by volume). An assessment of the leachate characteristics over time was required to address issues of pretreatment requirements, groundwater monitoring, and the potential sequestration and mobilization of heavy metals from the ash by organic ligands present in the sludge. This paper focuses on the biogeochemical conditions in the ash/sludge matrix that are conductive to the immobilization of heavy metals within the matrix via sulfide or polysulfide precipitation.

  2. Evaluation of monobasic calcium phosphate for the immobilization of heavy metals in contaminated soils from Lavrion.

    PubMed

    Theodoratos, Panagiotis; Papassiopi, Nymphodora; Xenidis, Anthimos

    2002-10-01

    The objective of this work was to evaluate the efficiency of monobasic calcium phosphate for the stabilization of heavy metals in contaminated soils. The treatment was applied on a soil sample from the Lavrion mining area, Greece, heavily contaminated with Pb, Zn, Cd and As and characterized as toxic in respect to Pb according to the US EPA toxicity characteristics leaching procedure (TCLP). The efficiency of stabilization was evaluated based on two criteria: (a) the reduction of metals mobility below the TCLP regulatory limits; (b) the reduction of phytoaccumulation. Phytoaccumulation was evaluated both indirectly by applying leaching tests using EDTA, DTPA and NaHCO(3) solutions and directly by carrying out pot experiments with Phaseolus vulgaris as plant indicator. This treatment was found to immobilize Pb and Cd, whereas As and Zn were slightly mobilized. No effect on phytoaccumulation was observed. Moreover, the treatment had a negative effect on plants growth, which was combined with a strong deficiency of Ca in the tissue of leaves. PMID:12169417

  3. Surface modified, collapsible controlled pore glass materials for sequestration and immobilization of trivalent metal ions.

    SciTech Connect

    Shkrob, I.; Tisch, A.; Marin, T.; Muntean, J.; Kaminski, M.; Kropf, A.

    2011-04-20

    We report a one-pot method for sequestration, containment, and immobilization of lanthanide (Ln) ions from dilute aqueous waste streams. The approach is based on the use of collapsible, surface modified controlled pore glass (CPG) nanomaterials. We present several approaches for a single-step chemical modification of 3-propylaminated CPGs that yield highly efficient Ln-extracting materials with distribution coefficients exceeding 10000 mL/g. The resulting Ln complexes were studied using X-ray absorption, magnetic resonance, and time-resolved luminescence spectroscopies. One of these CPG materials involving an imidodi(methanediphosphate) moiety demonstrated high extraction efficacy, significant ionic radius sensitivity, and exceptional tolerance to masking agents, which is conducive to its use for removal of traces of radionuclide ions from aqueous TALSPEAK raffinate (trivalent actinide-lanthanide separation by phosphorus reagent extraction from aqueous complexes process used in processing of spent nuclear fuel). The glass loaded with the extracted metal ions can be calcined and sintered at 1100 C, yielding fused material that buries Ln ions in the vitreous matrix. This processing temperature is significantly lower than 1700 C that is required for direct vitrification of lanthanide oxides in high-silica glass. X-ray absorption spectroscopy and acid leaching tests indicate that the immobilized ions are isolated and dispersed in the fused glass matrix. Thus, the method integrates Ln ions into the glass network. The resulting glass can be used for temporary storage or as the source of silica for production of borosilicate waste forms that are used for long-term disposal of high level radioactive waste.

  4. Chromophore-immobilized luminescent metal-organic frameworks as potential lighting phosphors and chemical sensors.

    PubMed

    Wang, Fangming; Liu, Wei; Teat, Simon J; Xu, Feng; Wang, Hao; Wang, Xinlong; An, Litao; Li, Jing

    2016-08-11

    An organic chromophore H4tcbpe-F was synthesized and immobilized into metal-organic frameworks along with two bipyridine derivatives as co-ligands to generate two strongly luminescent materials [Zn2(tcbpe-F)(4,4'-bpy)·xDMA] (1) and [Zn2(tcbpe-F)(bpee)·xDMA] (2) [4,4'-bpy = 4,4'-bipyridine, bpee = 4,4'-bipyridyl-ethylene, tcbpe-F = 4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis(3-fluoro-[1,1'-biphenyl]-4-carboxylic acid), DMA = N,N-dimethylacetamide]. Compounds 1 and 2 are isoreticular and feature a 2-fold interpenetrated three-dimensional porous structure. Both compounds give green-yellow emission under blue light excitation. Compound 1 has a high internal quantum yield of ∼51% when excited at 455 nm and shows selective luminescence signal change (e.g. emission energy and/or intensity) towards different solvents, including both aromatic and nonaromatic volatile organic species. These properties make it potentially useful as a lighting phosphor and a chemical sensor. PMID:27465685

  5. Application of accelerated carbonation on MSW combustion APC residues for metal immobilization and CO2 sequestration.

    PubMed

    Cappai, G; Cara, S; Muntoni, A; Piredda, M

    2012-03-15

    The present study focuses on the application of an aqueous phase accelerated carbonation treatment on air pollution control (APC) residues from municipal solid waste combustion, aimed at assessing its influence on the environmental behaviour of the residue under concern, as well as the potential of the process in terms of sequestration of the CO2. APC residues are considered hazardous waste and must be treated before final disposal in order to achieve the immobilization/mobilization of critical contaminants such as heavy metals as well as mobilization of soluble salts. The treatment applied proved to be effective in reducing the mobility of Pb, Zn, Cr, Cu and Mo, the optimum final pH for the carbonated APC residues being in a range of 10-10.5, whilst a mobilization effect was noticed for Sb and no effect was assessed for chlorides. The effect of carbonation treatment on the contaminant release was further evaluated by means of a sequential extraction procedure, indicating that the distribution of contaminants on water soluble, exchangeable and carbonate fraction was modified after treatment. The CO2 sequestration potential assessed for the APC residues showed that the carbonation technology could be a technically viable option in order to reduce emissions from WtE plants. PMID:21601357

  6. Immobilized metal-affinity chromatography protein-recovery screening is predictive of crystallographic structure success

    PubMed Central

    Choi, Ryan; Kelley, Angela; Leibly, David; Nakazawa Hewitt, Stephen; Napuli, Alberto; Van Voorhis, Wesley

    2011-01-01

    The recombinant expression of soluble proteins in Escherichia coli continues to be a major bottleneck in structural genomics. The establishment of reliable protocols for the performance of small-scale expression and solubility testing is an essential component of structural genomic pipelines. The SSGCID Protein Production Group at the University of Washington (UW-PPG) has developed a high-throughput screening (HTS) protocol for the measurement of protein recovery from immobilized metal-affinity chromatography (IMAC) which predicts successful purification of hexahistidine-tagged proteins. The protocol is based on manual transfer of samples using multichannel pipettors and 96-well plates and does not depend on the use of robotic platforms. This protocol has been applied to evaluate the expression and solubility of more than 4000 proteins expressed in E. coli. The UW-PPG also screens large-scale preparations for recovery from IMAC prior to purification. Analysis of these results show that our low-cost non-automated approach is a reliable method for the HTS demands typical of large structural genomic projects. This paper provides a detailed description of these protocols and statistical analysis of the SSGCID screening results. The results demonstrate that screening for proteins that yield high recovery after IMAC, both after small-scale and large-scale expression, improves the selection of proteins that can be successfully purified and will yield a crystal structure. PMID:21904040

  7. Affinity purification of metalloprotease from marine bacterium using immobilized metal affinity chromatography.

    PubMed

    Li, Shangyong; Wang, Linna; Yang, Juan; Bao, Jing; Liu, Junzhong; Lin, Shengxiang; Hao, Jianhua; Sun, Mi

    2016-06-01

    In this study, an efficient affinity purification protocol for an alkaline metalloprotease from marine bacterium was developed using immobilized metal affinity chromatography. After screening and optimization of the affinity ligands and spacer arm lengths, Cu-iminmodiacetic acid was chosen as the optimal affinity ligand, which was coupled to Sepharose 6B via a 14-atom spacer arm. The absorption analysis of this medium revealed a desorption constant Kd of 21.5 μg/mL and a theoretical maximum absorption Qmax of 24.9 mg/g. Thanks to this affinity medium, the enzyme could be purified by only one affinity purification step with a purity of approximately 95% pure when analyzed by high-performance liquid chromatography and reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis. The recovery of the protease activity reached 74.6%, which is much higher than the value obtained by traditional protocols (8.9%). These results contribute to the industrial purifications and contribute a significant reference for the purification of other metalloproteases. PMID:27058973

  8. Foam-based delivery of amendments to immobilize metals and radionuclides in deep vadose zone environments

    NASA Astrophysics Data System (ADS)

    Istok, J. D.; Jansik, D. P.; Foote, M.; Zhang, Z. F.; Wu, Y.; Hubbard, S. S.; Mattigod, S.; Zhong, L.; Wellman, D. M.

    2011-12-01

    Vadose zone environments can be sources and pathways for contaminant migration to groundwater aquifers, when very deep (> ~ 50 m) contaminants are difficult to remediate using conventional methods (e.g. excavation). This problem is particularly challenging in the arid western United States where the vadose zone may be > 100 m thick, extremely dry (~ 5 % water content), and in some cases, contaminated with a mixture of metals, radionuclides, and a variety of organic and inorganic co-contaminants. Chemical amendments have been developed for use in immobilizing contaminants in groundwater aquifers e.g., adding base to increase pH and sorb metals and radionuclides from acidic plumes or adding growth substrates to stimulate indigenous microbial activity and create reducing conditions that precipitate contaminants in poorly soluble mineral phases. However, delivering chemical amendments to dry vadose zone environments by injecting aqueous solutions may potentially mobilize contaminants by increasing the sediment's water content. Development of alternative methods for delivering chemical amendments to the deep vadose zone is a potentially useful approach for meeting remediation goals at some sites. We are exploring the use of foams, formed from liquid surfactants and air, as an agent to deliver chemical amendments to the deep vadose zone at the Hanford Site where the targeted contaminants include U, Tc, and nitrate. Injected foams can carry chemical amendments with limited amounts of water, reducing the potential for contaminant mobilization. We will present the results of numerical modeling, and pore- to intermediate scale laboratory experiments aimed at formulating foams to deliver polyphosphate to deep vadose zone sediments contaminated with uranium. When phosphate, delivered by injected foam, reacts with vadose zone pore water, poorly soluble, apatite-like phosphate minerals precipitate and sequester U(VI), limiting its downward migration to the underlying groundwater

  9. An integrated approach to safer plant production on metal contaminated soils using species selection and chemical immobilization.

    PubMed

    Kim, Hyuck Soo; Seo, Byoung-Hwan; Bae, Jun-Sik; Kim, Won-Il; Owens, Gary; Kim, Kwon-Rae

    2016-09-01

    In order to examine the species specific accumulation of heavy metals in medicinal crops, seven different common medicinal plants were cultivated on a Cd (55mgkg(-1)) and Pb (1283mgkg(-1)) contaminated soil. Subsequently, the effect of various immobilizing agents, applied in isolation and in combination, on Cd and Pb uptake by two medicinal plant species was examined. Cadmium and Pb root concentrations in medicinal plants grown in the control soil varied between 0.5 and 2.6mgkg(-1) for Cd and 3.2 and 36.4mgkg(-1) for Pb. The highest accumulation occurred in Osterici Radix (Ostericum koreanum) and Ginger (Zingiber officinale) and the lowest in Yam (Dioscorea batatas). Application of immobilizing agents significantly reduced both Cd and Pb concentrations in all medicinal plants examined, where the most effective single immobilizing agent was lime fertilizer (LF). Application of combination treatments involving sorption agents such as compost together with lime further decreased Cd and Pb concentrations from 1.3 and 25.3mgkg(-1) to 0.2 and 4.3mgkg(-1), respectively, which was well below the corresponding WHO guidelines. Thus appropriate immobilizing agents in combination with species selection can be practically used for safer medicinal plant production. PMID:27213564

  10. Metal fire implications for advanced reactors. Part 1, literature review.

    SciTech Connect

    Nowlen, Steven Patrick; Radel, Ross F.; Hewson, John C.; Olivier, Tara Jean; Blanchat, Thomas K.

    2007-10-01

    Public safety and acceptance is extremely important for the nuclear power renaissance to get started. The Advanced Burner Reactor and other potential designs utilize liquid sodium as a primary coolant which provides distinct challenges to the nuclear power industry. Fire is a dominant contributor to total nuclear plant risk events for current generation nuclear power plants. Utilizing past experience to develop suitable safety systems and procedures will minimize the chance of sodium leaks and the associated consequences in the next generation. An advanced understanding of metal fire behavior in regards to the new designs will benefit both science and industry. This report presents an extensive literature review that captures past experiences, new advanced reactor designs, and the current state-of-knowledge related to liquid sodium combustion behavior.

  11. Techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides in contaminated subsurface environments

    SciTech Connect

    Jardine, P.M.; Watson, D.B.; Blake, D.A.; Beard, L.P.; Brooks, S.C.; Carley, J.M.; Criddle, C.S.; Doll, W.E.; Fields, M.W.; Fendorf, S.E.; Geesey, G.G.; Ginder-Vogel, M.; Hubbard, S.S.; Istok, J.D.; Kelly, S.; Kemner, K.M.; Peacock, A.D.; Spalding, B.P.; White, D.C.; Wolf, A.; Wu, W.; Zhou, J.

    2004-11-14

    Department of Energy (DOE) facilities within the weapons complex face a daunting challenge of remediating huge below inventories of legacy radioactive and toxic metal waste. More often than not, the scope of the problem is massive, particularly in the high recharge, humid regions east of the Mississippi river, where the off-site migration of contaminants continues to plague soil water, groundwater, and surface water sources. As of 2002, contaminated sites are closing rapidly and many remediation strategies have chosen to leave contaminants in-place. In situ barriers, surface caps, and bioremediation are often the remedial strategies of chose. By choosing to leave contaminants in-place, we must accept the fact that the contaminants will continue to interact with subsurface and surface media. Contaminant interactions with the geosphere are complex and investigating long term changes and interactive processes is imperative to verifying risks. We must be able to understand the consequences of our action or inaction. The focus of this manuscript is to describe recent technical developments for assessing the performance of in situ bioremediation and immobilization of subsurface metals and radionuclides. Research within DOE's NABIR and EMSP programs has been investigating the possibility of using subsurface microorganisms to convert redox sensitive toxic metals and radionuclides (e.g. Cr, U, Tc, Co) into a less soluble, less mobile forms. Much of the research is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of metals and radionuclides so that they are immobilized in situ for long time periods. The approach is difficult, however, since subsurface media and waste constituents are complex with competing electron acceptors and hydrogeological conditions making biostimulation a challenge. Performance assessment of in situ biostimulation strategies is also difficult and typically requires detailed

  12. Techniques for Assessing the Performance of In Situ Bioreduction and Immobilization of Metals and Radionuclides in Contaminated Subsurface Environments

    NASA Astrophysics Data System (ADS)

    Watson, D. B.; Jardine, P. M.

    2005-05-01

    Department of Energy (DOE) facilities within the weapons complex face a daunting challenge of remediating huge below inventories of legacy radioactive and toxic metal waste. More often than not, the scope of the problem is massive, particularly in the high recharge, humid regions east of the Mississippi river, where the off-site migration of contaminants continues to plague soil water, groundwater, and surface water sources. As of 2002, contaminated sites are closing rapidly and many remediation strategies have chosen to leave contaminants in-place. In situ barriers, surface caps, and bioremediation are often the remedial strategies of chose. By choosing to leave contaminants in-place, we must accept the fact that the contaminants will continue to interact with subsurface and surface media. Contaminant interactions with the geosphere are complex and investigating long term changes and interactive processes is imperative to verifying risks. We must be able to understand the consequences of our action or inaction. The focus of this presentation is to describe recent technical developments for assessing the performance of in situ bioremediation and immobilization of subsurface metals and radionuclides. Research within DOE's NABIR and EMSP programs has been investigating the possibility of using subsurface microorganisms to convert redox sensitive toxic metals and radionuclides (e.g. Cr, U, Tc, Co) into a less soluble, less mobile forms. Much of the research is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of metals and radionuclides so that they are immobilized in situ for long time periods. The approach is difficult, however, since subsurface media and waste constituents are complex with competing electron acceptors and hydrogeological conditions making biostimulation a challenge. Performance assessment of in situ biostimulation strategies is also difficult and typically requires detailed

  13. Comparing multistep immobilized metal affinity chromatography and multistep TiO2 methods for phosphopeptide enrichment.

    PubMed

    Yue, Xiaoshan; Schunter, Alissa; Hummon, Amanda B

    2015-09-01

    Phosphopeptide enrichment from complicated peptide mixtures is an essential step for mass spectrometry-based phosphoproteomic studies to reduce sample complexity and ionization suppression effects. Typical methods for enriching phosphopeptides include immobilized metal affinity chromatography (IMAC) or titanium dioxide (TiO2) beads, which have selective affinity and can interact with phosphopeptides. In this study, the IMAC enrichment method was compared with the TiO2 enrichment method, using a multistep enrichment strategy from whole cell lysate, to evaluate their abilities to enrich for different types of phosphopeptides. The peptide-to-beads ratios were optimized for both IMAC and TiO2 beads. Both IMAC and TiO2 enrichments were performed for three rounds to enable the maximum extraction of phosphopeptides from the whole cell lysates. The phosphopeptides that are unique to IMAC enrichment, unique to TiO2 enrichment, and identified with both IMAC and TiO2 enrichment were analyzed for their characteristics. Both IMAC and TiO2 enriched similar amounts of phosphopeptides with comparable enrichment efficiency. However, phosphopeptides that are unique to IMAC enrichment showed a higher percentage of multiphosphopeptides as well as a higher percentage of longer, basic, and hydrophilic phosphopeptides. Also, the IMAC and TiO2 procedures clearly enriched phosphopeptides with different motifs. Finally, further enriching with two rounds of TiO2 from the supernatant after IMAC enrichment or further enriching with two rounds of IMAC from the supernatant TiO2 enrichment does not fully recover the phosphopeptides that are not identified with the corresponding multistep enrichment. PMID:26237447

  14. Comprehensive and Reproducible Phosphopeptide Enrichment Using Iron Immobilized Metal Ion Affinity Chromatography (Fe-IMAC) Columns

    PubMed Central

    Ruprecht, Benjamin; Koch, Heiner; Medard, Guillaume; Mundt, Max; Kuster, Bernhard; Lemeer, Simone

    2015-01-01

    Advances in phosphopeptide enrichment methods enable the identification of thousands of phosphopeptides from complex samples. Current offline enrichment approaches using TiO2, Ti, and Fe immobilized metal ion affinity chromatography (IMAC) material in batch or microtip format are widely used, but they suffer from irreproducibility and compromised selectivity. To address these shortcomings, we revisited the merits of performing phosphopeptide enrichment in an HPLC column format. We found that Fe-IMAC columns enabled the selective, comprehensive, and reproducible enrichment of phosphopeptides out of complex lysates. Column enrichment did not suffer from bead-to-sample ratio issues and scaled linearly from 100 μg to 5 mg of digest. Direct measurements on an Orbitrap Velos mass spectrometer identified >7500 unique phosphopeptides with 90% selectivity and good quantitative reproducibility (median cv of 15%). The number of unique phosphopeptides could be increased to more than 14,000 when the IMAC eluate was subjected to a subsequent hydrophilic strong anion exchange separation. Fe-IMAC columns outperformed Ti-IMAC and TiO2 in batch or tip mode in terms of phosphopeptide identification and intensity. Permutation enrichments of flow-throughs showed that all materials largely bound the same phosphopeptide species, independent of physicochemical characteristics. However, binding capacity and elution efficiency did profoundly differ among the enrichment materials and formats. As a result, the often quoted orthogonality of the materials has to be called into question. Our results strongly suggest that insufficient capacity, inefficient elution, and the stochastic nature of data-dependent acquisition in mass spectrometry are the causes of the experimentally observed complementarity. The Fe-IMAC enrichment workflow using an HPLC format developed here enables rapid and comprehensive phosphoproteome analysis that can be applied to a wide range of biological systems. PMID

  15. Immobilized metal ion affinity chromatography on Co2+-carboxymethylaspartate-agarose Superflow, as demonstrated by one-step purification of lactate dehydrogenase from chicken breast muscle.

    PubMed

    Chaga, G; Hopp, J; Nelson, P

    1999-02-01

    A rapid method for the purification of lactate dehydrogenase from whole chicken muscle extract in one chromatographic step is reported. The purification procedure can be accomplished in less than 1 h. A new type of immobilized metal ion affinity chromatography adsorbent is used that can be utilized at linear flow rates higher than 5 cm/min. The final preparation of the enzyme was with purity higher than 95% as ascertained by SDS-PAGE. Three immobilized metal ions (Ni2+, Zn2+ and Co2+) were compared for their binding properties towards the purified enzyme. The binding site of the enzyme for immobilized intermediate metal ions was determined after cleavage with CNBr and binding studies of the derivative peptides on immobilized Co2+. A peptide located on the N-terminus of the enzyme, implicated in the binding, has great potential as a purification tag in fusion proteins. PMID:9889081

  16. Preliminary study of the metal binding site of an anti-DTPA-indium antibody by equilibrium binding immunoassays and immobilized metal ion affinity chromatography.

    PubMed

    Boden, V; Colin, C; Barbet, J; Le Doussal, J M; Vijayalakshmi, M

    1995-01-01

    Creating metal coordination sites by modifying an existing enzyme or by eliciting antibodies against metal chelate haptens is of great interest in biotechnology to create enzyme catalysts with novel specificities. Here, we investigate the metal binding potential of a monoclonal antibody raised against a DTPA-In(III) hapten (mAb 734). We study its relative binding efficiency to metals of biological relevance by equilibrium binding immunoassays and immobilized metal ion affinity chromatography, two approaches which can give complementary information regarding composition and/or structure of the metal binding site(s). Fe(III), Fe(II), Cu(II), Mg(II), Ca(II), and Zn(II) binding was compared to In(III). All of them were shown to displace indium, but their affinity for mAb 734 decreased by 100-fold compared to indium. Competitive metal binding immunoassays between Zn(II) and In(III) revealed an unusual behavior by Zn(II) which remains to be explained. Moreover, IMAC allowed us to predict the metal binding amino acids involved in the antibody paratope. The antibody metal binding site was shown to contain at least two histidine residues in a cluster, and the presence of aspartic and glutamic acid as well as cysteine residues could not be excluded. Thus, simple competition studies allows us to obtain some partial information on the metal binding structural features of this anti-metal chelate antibody and to guide our screening of its catalytic potential. PMID:7578356

  17. An evaluation of the effectiveness of novel industrial by-products and organic wastes on heavy metal immobilization in Pb-Zn mine tailings.

    PubMed

    Yang, Shengxiang; Cao, Jianbing; Hu, Wenyong; Zhang, Xiaojun; Duan, Chun

    2013-10-01

    The in situ immobilization of heavy metals using various easily obtainable amendments is a cost-effective and practical method in the remediation of contaminated sites. In this study, two novel industrial waste materials (sweet sorghum vinasse and medicinal herb residues), spent mushroom compost and municipal solid wastes were used as amendments to assess their potential value for the in situ immobilization of heavy metals in tailings from a Pb-Zn mine in South China. Our results demonstrate that all three freely-available organic wastes decrease the deionized water (DW)- and diethylene-triamine-pentaacetic acid (DTPA)-extractable metal concentrations, enhance the enzyme activity, reduce the metal concentration in plant tissues, and could be used for the remediation of these Pb-Zn mine tailings metals by immobilization. The municipal solid waste failed to reduce the metal concentration in tailings and plant tissues and therefore would not be a suitable immobilizing agent. The potential value of these materials as immobilizers of heavy metals and their remediation efficacy deserve further studies in large-scale field trials. PMID:24056870

  18. Effect of SiO2 on immobilization of metals and encapsulation of a glass network in slag.

    PubMed

    Kuo, Yi-Ming; Lin, Ta-Chang; Tsai, Perng-Jy

    2003-11-01

    The final disposal of ash from an incinerator is of special concern because of the possibility of its releasing toxic substances. Melting/vitrification has been regarded as a prospective technology of ash treatment. The object of this investigation was to evaluate the effect of silica (SiO2) addition on the immobilization of hazardous metals and the encapsulation of a glass network during the vitrification process. Four specimens with SiO2/fly ash mixing ratios of 0, 0.1, 0.2, and 0.3, respectively, were tested. The mobility of metals in slag was then estimated by a sequential extraction procedure. X-ray diffraction analysis indicates that SiO2 leads to the polymerization of silicates. The encapsulation of aluminum, calcium, and magnesium would not be observed unless adequate amount of SiO2 was added. It was also found that SiO2 addition enhances the formation of a compact and interconnected glass network structure and, thus, contributes to the chemical stability of metals in slag. After vitrification, the mobility of cadmium, copper, iron, chromium, nickel, lead, and zinc was significantly reduced. However, there is no significant correlation between the immobilization of these metals and the addition of SiO2. PMID:14649761

  19. Comparison of heavy metal immobilization in contaminated soils amended with peat moss and peat moss-derived biochar.

    PubMed

    Park, Jin Hee; Lee, Seul-Ji; Lee, Myoung-Eun; Chung, Jae Woo

    2016-04-20

    There have been contradictory viewpoints whether soil amendments immobilize or mobilize heavy metals. Therefore, this study evaluated the mobility and bioavailability of Pb, Cu, and Cd in contaminated soil (1218 mg Pb per kg, 63.2 mg Cu per kg, 2.8 mg Cd per kg) amended with peat moss (0.22, 0.43, and 1.29% carbon ratio) and peat moss-derived biochar (0.38, 0.75, and 2.26% carbon ratio) at 0.5, 1, 3% levels. The more peat moss added, the stronger both mobility and bioavailability of Pb, Cu, and Cd would be. In contrast, the addition of peat moss-derived biochar significantly reduced both mobility and bioavailability of heavy metals through the coordination of metal electrons to C[double bond, length as m-dash]C (π-electron) bonds and increased pH. Maximum immobilization was observed in 3% peat moss-derived biochar treatment after 10 days of incubation, which was measured at 97.8%, 100%, and 77.2% for Pb, Cu, and Cd, respectively. Since peat moss and peat moss-derived biochar showed conflicting effectiveness in mobility and bioavailability of heavy metals, soil amendments should be carefully applied to soils for remediation purposes. PMID:27055368

  20. Plutonium Immobilization Task 5.6 Metal Conversion: Milestone Report - Perform Feasibility Demonstrations on Pu-Al Alloys

    SciTech Connect

    Zundelevich, Y; Kerns, J; Bannochie, C

    2001-04-12

    The Plutonium Conversion Task within the Plutonium Immobilization Program (PIP) transforms incoming plutonium (Pu) feed materials into an oxide acceptable for blending with ceramic precursors. One of the feed materials originally planned for PIP was unirradiated fuel, which consisted mainly of the Zero Power Plutonium Reactor (ZPPR) fuel. Approximately 3.5 metric tons of Pu is in ZPPR fuel. The ZPPR fuel is currently stored at the Argonne National Laboratory-West as stainless steel clad metal plates and oxide pellets, with the vast majority of the Pu in the metal plates. The metal plates consist of a Pu-U-Mo alloy (containing 90% of the ZPPR plutonium metal) and a Pu-Al alloy (containing 10% of the ZPPR plutonium metal). The Department of Energy (DOE) decided that ZPPR fuel is a national asset and, therefore, not subject to disposition. This report documents work done prior to that decision. The Hydnde-Oxidation (HYDOX) Process was selected as the method for Metal Conversion in PIP because it provides a universal means for preparing oxide from all feed materials. HYDOX incorporates both the hydride process, originally developed to separate Pu from other pit materials, as well as the oxide formation step. Plutonium hydride is very reactive and is readily converted to either the nitride or the oxide. A previous feasibility study demonstrated that the Pu-U-Mo alloy could be successfully converted to oxide via the HYDOX Process. Another Metal Conversion milestone was to demonstrate the feasibility of the HYDOX Process for converting plutonium-aluminum (Pu-Al) alloy in ZPPR fuel plates to an acceptable oxide. This report documents the results of the latter feasibility study which was performed before the DOE decision to retain ZPPR fuel rather than immobilize it.

  1. Immobilization of Thiadiazole Derivatives on Magnetite Mesoporous Silica Shell Nanoparticles in Application to Heavy Metal Removal from Biological Samples

    SciTech Connect

    Emadi, Masoomeh; Shams, Esmaeil

    2010-12-02

    In this report magnetite was synthesized by a coprecipitation method, then coated with a layer of silica. Another layer of mesoporous silica was added by a sol-gel method, then 5-amino-1,3,4-thiadiazole-thiol (ATT) was immobilized onto the synthesized nanoparticles with a simple procedure. This was followed by a series of characterizations, including transmission electron microscopy (TEM), FT-IR spectrum, elemental analysis and XRD. Heavy metal uptake of the modified nanoparticles was examined by atomic absorption spectroscopy. For further investigation we chose Cu{sup 2+} as the preferred heavy metal to evaluate the amount of adsorption, as well as the kinetics and mechanism of adsorption. Finally, the capacity of our nanoparticles for the heavy metal removal from blood was shown. We found that the kinetic rate of Cu{sup 2+} adsorption was 0.05 g/mg/min, and the best binding model was the Freundlich isotherm.

  2. Immobilization of Bacillus subtilis lipase on a Cu-BTC based hierarchically porous metal-organic framework material: a biocatalyst for esterification.

    PubMed

    Cao, Yu; Wu, Zhuofu; Wang, Tao; Xiao, Yu; Huo, Qisheng; Liu, Yunling

    2016-04-28

    Bacillus subtilis lipase (BSL2) has been successfully immobilized into a Cu-BTC based hierarchically porous metal-organic framework material for the first time. The Cu-BTC hierarchically porous MOF material with large mesopore apertures is prepared conveniently by using a template-free strategy under mild conditions. The immobilized BSL2 presents high enzymatic activity and perfect reusability during the esterification reaction. After 10 cycles, the immobilized BSL2 still exhibits 90.7% of its initial enzymatic activity and 99.6% of its initial conversion. PMID:26988724

  3. An immobilized and reusable Cu(I) catalyst for metal ion-free conjugation of ligands to fully deprotected oligonucleotides through click reaction.

    PubMed

    Eltepu, Laxman; Jayaraman, Muthusamy; Rajeev, Kallanthottathil G; Manoharan, Muthiah

    2013-01-01

    Chelation of Cu(I) ions to an immobilized hydrophilic tris(triazolylmethyl)amine chelator on a solid support allowed synthesis of RNA oligonucleotide conjugates from completely deprotected alkyne-oligonucleotides. No oligonucleotide strand degradation or metal ion contamination was observed. Furthermore, use of the immobilized copper(I) ion overcame regioselectivity issues associated with strain-promoted copper-free azide-alkyne cycloaddition. PMID:23172132

  4. Immobilization of heavy metals in polluted soils by the addition of zeolitic material synthesized from coal fly ash.

    PubMed

    Querol, Xavier; Alastuey, Andrés; Moreno, Natàlia; Alvarez-Ayuso, Esther; García-Sánchez, Antonio; Cama, Jordi; Ayora, Carles; Simón, Mariano

    2006-01-01

    The use of zeolitic material synthesized from coal fly ash for the immobilization of pollutants in contaminated soils was investigated in experimental plots in the Guadiamar Valley (SW Spain). This area was affected by a pyrite slurry spill in April 1998. Although reclamation activities were completed in a few months, residual pyrite slurry mixed with soil accounted for relatively high leachable levels of trace elements such as Zn, Pb, As, Cu, Sb, Co, Tl and Cd. Phytoremediation strategies were adopted for the final recovery of the polluted soils. The immobilization of metals had previously been undertaken to avoid leaching processes and the consequent groundwater pollution. To this end, 1100 kg of high NaP1 (Na6[(AlO2)6(SiO2)10] .15H2O) zeolitic material was synthesized using fly ash from the Teruel power plant (NE Spain), in a 10 m3 reactor. This zeolitic material was manually applied using different doses (10000-25000 kg per hectare), into the 25 cm topsoil. Another plot (control) was maintained without zeolite. Sampling was carried out 1 and 2 years after the zeolite addition. The results show that the zeolitic material considerably decreases the leaching of Cd, Co, Cu, Ni, and Zn. The sorption of metals in soil clay minerals (illite) proved to be the main cause contributing to the immobilization of these pollutants. This sorption could be a consequence of the rise in pH from 3.3 to 7.6 owing to the alkalinity of the zeolitic material added (caused by traces of free lime in the fly ash, or residual NaOH from synthesis). PMID:16039695

  5. Development of an immobilization process for heavy metal containing galvanic solid wastes by use of sodium silicate and sodium tetraborate.

    PubMed

    Aydın, Ahmet Alper; Aydın, Adnan

    2014-04-15

    Heavy metal containing sludges from wastewater treatment plants of electroplating industries are designated as hazardous waste since their improper disposal pose high risks to environment. In this research, heavy metal containing sludges of electroplating industries in an organized industrial zone of Istanbul/Turkey were used as real-sample model for development of an immobilization process with sodium tetraborate and sodium silicate as additives. The washed sludges have been precalcined in a rotary furnace at 900°C and fritted at three different temperatures of 850°C, 900°C and 950°C. The amounts of additives were adjusted to provide different acidic and basic oxide ratios in the precalcined sludge-additive mixtures. Leaching tests were conducted according to the toxicity characteristic leaching procedure Method 1311 of US-EPA. X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope-energy dispersive spectrometer (SEM-EDS) and flame atomic absorption spectroscopy (FAAS) have been used to determine the physical and chemical changes in the products. Calculated oxide molar ratios in the precalcined sludge-additive mixtures and their leaching results have been used to optimize the stabilization process and to determine the intervals of the required oxide ratios which provide end-products resistant to leaching procedure of US-EPA. The developed immobilization-process provides lower energy consumption than sintering-vitrification processes of glass-ceramics. PMID:24530878

  6. Nanoengineered analytical immobilized metal affinity chromatography stationary phase by atom transfer radical polymerization: Separation of synthetic prion peptides

    PubMed Central

    McCarthy, P.; Chattopadhyay, M.; Millhauser, G.L.; Tsarevsky, N.V.; Bombalski, L.; Matyjaszewski, K.; Shimmin, D.; Avdalovic, N.; Pohl, C.

    2010-01-01

    Atom transfer radical polymerization (ATRP) was employed to create isolated, metal-containing nanoparticles on the surface of non-porous polymeric beads with the goal of developing a new immobilized metal affnity chromatography (IMAC) stationary phase for separating prion peptides and proteins. Transmission electron microscopy was used to visualize nanoparticles on the substrate surface. Individual ferritin molecules were also visualized as ferritin–nanoparticle complexes. The column's resolving power was tested by synthesizing peptide analogs to the copper binding region of prion protein and injecting mixtures of these analogs onto the column. As expected, the column was capable of separating prion-related peptides differing in number of octapeptide repeat units (PHGGGWGQ), (PHGGGWGQ)2, and (PHGGGWGQ)4. Unexpectedly, the column could also resolve peptides containing the same number of repeats but differing only in the presence of a hydrophilic tail, Q → A substitution, or amide nitrogen methylation. PMID:17481564

  7. Subcritical water treatment of explosive and heavy metals co-contaminated soil: Removal of the explosive, and immobilization and risk assessment of heavy metals.

    PubMed

    Islam, Mohammad Nazrul; Jung, Ho-Young; Park, Jeong-Hun

    2015-11-01

    Co-contamination of explosives and heavy metals (HMs) in soil, particularly army shooting range soil, has received increasing environmental concern due to toxicity and risks to ecological systems. In this study, a subcritical water (SCW) extraction process was used to remediate the explosives-plus-HMs-co-contaminated soil. A quantitative evaluation of explosives in the treated soil, compared with untreated soil, was applied to assess explosive removal. The immobilization of HMs was assessed by toxicity characteristic leaching procedure tests, and by investigating the migration of HMs fractions. The environmental risk of HMs in the soil residue was assessed according to the risk assessment code (RAC) and ecological risk indices (Er and RI). The results indicated that SCW treatment could eliminate the explosives, >99%, during the remediation, while the HM was effectively immobilized. The effect of water temperature on reducing the explosives and the risk of HMs in soil was observed. A marked increase in the non-bioavailable concentration of each HM was observed, and the leaching rate of HMs was decreased by 70-97% after SCW treatment at 250 °C, showing the effective immobilization of HMs. According to the RAC or RI, each tested HM showed no or low risk to the environment after treatment. PMID:26340419

  8. Cadmium accumulation by a Citrobacter sp. immobilized on gel and solid supports: applicability to the treatment of liquid wastes containing heavy metal cations

    SciTech Connect

    Macaskie, L.E.; Wates, J.M.; Dean, A.C.R.

    1987-01-01

    Polyacrylamide gel-immobilized cells of a Citrobacter sp. removed cadmium from flows supplemented with glycerol 2-phosphate, the metal uptake mechanism being mediated by the activity of a cell-bound phosphatase that precipitates liberated inorganic phosphate with heavy metals at the cell surface. The constraints of elevated flow rate and temperature were investigated and the results discussed in terms of the kinetics of immobilized enzymes. Loss in activity with respect to cadmium accumulation but not inorganic phosphate liberation was observed at acid pH and was attributed to the pH-dependent solubility of cadmium phosphate. Similarly high concentrations of chloride ions, and traces of cyanide inhibited cadmium uptake and this was attributed to the ability of these anions to complex heavy metals, especially the ability of CN/sup -/ to form complex anions with Cd/sup 2 +/. The data are discussed in terms of the known chemistry of chloride and cyanide-cadmium complexes and the relevance of these factors in the treatment of metal-containing liquid wastes is discussed. The cells immobilized in polyacrylamide provided a convenient small-scale laboratory model system. It was found that the Citrobacter sp. could be immobilized on glass supports with no chemical treatment or modification necessary. Such cells were also effective in metal accumulation and a prototype system more applicable to the treatment of metal-containing streams on a larger scale is described.

  9. Evaluation of heavy metals in hazardous automobile shredder residue thermal residue and immobilization with novel nano-size calcium dispersed reagent.

    PubMed

    Lee, Chi-Hyeon; Truc, Nguyen Thi Thanh; Lee, Byeong-Kyu; Mitoma, Yoshiharu; Mallampati, Srinivasa Reddy

    2015-10-15

    This study was conducted to synthesize and apply a nano-size calcium dispersed reagent as an immobilization material for heavy metal-contaminated automobile shredder residues (ASR) dust/thermal residues in dry condition. Simple mixing with a nanometallic Ca/CaO/PO4 dispersion mixture immobilized 95-100% of heavy metals in ASR dust/thermal residues (including bottom ash, cavity ash, boiler and bag filter ash). The quantity of heavy metals leached from thermal residues after treatment by nanometallic Ca/CaO/PO4 was lower than the Korean standard regulatory limit for hazardous waste landfills. The morphology and elemental composition of the nanometallic Ca/CaO-treated ASR residue were characterized by field emission scanning election microscopy combined with electron dispersive spectroscopy (FE-SEM/EDS). The results indicated that the amounts of heavy metals detectable on the ASR thermal residue surface decreased and the Ca/PO4 mass percent increased. X-ray diffraction (XRD) pattern analysis indicated that the main fraction of enclosed/bound materials on ASR residue included Ca/PO4- associated crystalline complexes, and that immobile Ca/PO4 salts remarkably inhibited the desorption of heavy metals from ASR residues. These results support the potential use of nanometallic Ca/CaO/PO4 as a simple, suitable and highly efficient material for the gentle immobilization of heavy metals in hazardous ASR thermal residue in dry condition. PMID:25935297

  10. Synergistic catalysis of metal-organic framework-immobilized Au-Pd nanoparticles in dehydrogenation of formic acid for chemical hydrogen storage.

    PubMed

    Gu, Xiaojun; Lu, Zhang-Hui; Jiang, Hai-Long; Akita, Tomoki; Xu, Qiang

    2011-08-10

    Bimetallic Au-Pd nanoparticles (NPs) were successfully immobilized in the metal-organic frameworks (MOFs) MIL-101 and ethylenediamine (ED)-grafted MIL-101 (ED-MIL-101) using a simple liquid impregnation method. The resulting composites, Au-Pd/MIL-101 and Au-Pd/ED-MIL-101, represent the first highly active MOF-immobilized metal catalysts for the complete conversion of formic acid to high-quality hydrogen at a convenient temperature for chemical hydrogen storage. Au-Pd NPs with strong bimetallic synergistic effects have a much higher catalytic activity and a higher tolerance with respect to CO poisoning than monometallic Au and Pd counterparts. PMID:21761819

  11. DEVELOPMENT OF GLASS COMPOSITIONS TO IMMOBILIZE ALKALI, ALKALINE EARTH, LANTHANIDE AND TRANSITION METAL FISSION PRODUCTS FROM NUCLEAR FUEL REPROCESSING

    SciTech Connect

    Marra, J.; Billings, A.

    2009-06-24

    The Advanced Fuel Cycle Initiative (AFCI) waste management strategy revolves around specific treatment of individual or groups of separated waste streams. A goal for the separations processes is to efficiently manage the waste to be dispositioned as high level radioactive waste. The Advanced Fuel Cycle Initiative (AFCI) baseline technology for immobilization of the lanthanide (Ln) and transition metal fission product (TM) wastes is vitrification into a borosilicate glass. A current interest is to evaluate the feasibility of vitrifying combined waste streams to most cost effectively immobilize the wastes resulting from aqueous fuel reprocessing. Studies showed that high waste loadings are achievable for the Ln only (Option 1) stream. Waste loadings in excess of 60 wt % (on a calcined oxide basis) were demonstrated via a lanthanide borosilicate (LaBS) glass. The resulting glasses had excellent relative durability as determined by the Product Consistency Test (PCT). For a combined Ln and TM waste stream glass (Option 2), noble metal solubility was found to limit waste loading. However, the measured PCT normalized elemental releases for this glass were at least an order of magnitude below that of Environmental Assessment (EA) glass. Current efforts to evaluate the feasibility of vitrifying combined Ln, TM, alkali (Cs is the primary radionuclide of concern) and alkaline earth (Sr is the primary radionuclide of concern) wastes (Option 3) have shown that these approaches are feasible. However, waste loading limitations with respect to heat load (Cs/Sr loading), molybdenum solubility and/or noble metal solubility will likely be realized and must be considered in determining the cost effectiveness of these approaches.

  12. Mycoextraction by Clitocybe maxima combined with metal immobilization by biochar and activated carbon in an aged soil.

    PubMed

    Wu, Bin; Cheng, Guanglei; Jiao, Kai; Shi, Wenjin; Wang, Can; Xu, Heng

    2016-08-15

    To develop an eco-friendly and efficient route to remediate soil highly polluted with heavy metals, the idea of mycoextraction combined with metal immobilization by carbonaceous sorbents (biochar and activated carbon) was investigated in this study. Results showed that the application of carbonaceous amendments decreased acid soluble Cd and Cu by 5.13-14.06% and 26.86-49.58%, respectively, whereas the reducible and oxidizable fractions increased significantly as the amount of carbonaceous amendments added increased. The biological activities (microbial biomass, soil enzyme activities) for treatments with carbonaceous sorbents were higher than those of samples without carbonaceous amendments. Clitocybe maxima (C. maxima) simultaneously increased soil enzyme activities and the total number of microbes. Biochar and activated carbon both showed a positive effect on C. maxima growth and metal accumulation. The mycoextraction efficiency of Cd and Cu in treatments with carbonaceous amendments enhanced by 25.64-153.85% and 15.18-107.22%, respectively, in response to that in non-treated soil, which showed positive correlation to the augment of biochar and activated carbon in soil. Therefore, this work suggested the effectiveness of mycoextraction by C. maxima combined the application of biochar and activated carbon in immobilising heavy metal in contaminated soil. PMID:27110984

  13. Metal immobilization in hazardous contaminated minesoils after marble slurry waste application. A field assessment at the Tharsis mining district (Spain).

    PubMed

    Fernández-Caliani, J C; Barba-Brioso, C

    2010-09-15

    A one-year field trial was conducted at the abandoned mine site of Tharsis (Spain) in order to assess the potential value of waste sludge generated during the processing of marble stone, as an additive for assisting natural remediation of heavily contaminated acid mine soils. An amendment of 22 cmol(c) of lime per kilogram of soil was applied to raise the pH level from 3.2 to above 6. The amendment application was effective in reducing concentrations of Al, Fe, Mn, sulfate and potentially hazardous trace elements (mainly Cu, Pb, Zn and Cd) in the most labile metal pools (water-soluble and EDTA-extractable fractions). Geochemical equilibrium calculations indicate that sulfate complexes and free metal ions were the dominant aqueous species in the soil solution. Metal coprecipitation with nanocrystalline ferric oxyhydroxides may be the major chemical mechanism of amendment-induced immobilization. The alleviating effect of the soil amendment on the metal bioavailability and phytotoxicity showed promise for assisting natural revegetation of the mine land. PMID:20541314

  14. Inhibition of acid mine drainage and immobilization of heavy metals from copper flotation tailings using a marble cutting waste

    NASA Astrophysics Data System (ADS)

    Tozsin, Gulsen

    2016-01-01

    Acid mine drainage (AMD) with high concentrations of sulfates and metals is generated by the oxidation of sulfide bearing wastes. CaCO3-rich marble cutting waste is a residual material produced by the cutting and polishing of marble stone. In this study, the feasibility of using the marble cutting waste as an acid-neutralizing agent to inhibit AMD and immobilize heavy metals from copper flotation tailings (sulfide- bearing wastes) was investigated. Continuous-stirring shake-flask tests were conducted for 40 d, and the pH value, sulfate content, and dissolved metal content of the leachate were analyzed every 10 d to determine the effectiveness of the marble cutting waste as an acid neutralizer. For comparison, CaCO3 was also used as a neutralizing agent. The average pH value of the leachate was 2.1 at the beginning of the experiment ( t = 0). In the experiment employing the marble cutting waste, the pH value of the leachate changed from 6.5 to 7.8, and the sulfate and iron concentrations decreased from 4558 to 838 mg/L and from 536 to 0.01 mg/L, respectively, after 40 d. The marble cutting waste also removed more than 80wt% of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) from AMD generated by copper flotation tailings.

  15. Engineering of a metal coordinating site into human glutathione transferase M1-1 based on immobilized metal ion affinity chromatography of homologous rat enzymes.

    PubMed

    Chaga, G; Widersten, M; Andersson, L; Porath, J; Danielson, U H; Mannervik, B

    1994-09-01

    Rat glutathione transferase (GST) 3-3 binds to Ni(II)-iminodiacetic acid (IDA)-agarose, whereas other GSTs that are abundant in rat liver do not bind to this immobilized metal ion affinity chromatography (IMAC) adsorbent. Rat GST 3-3 contains two superficially located amino acid residues, His84 and His85, that are suitably positioned for coordination to Ni(II)-IDA-agarose. This particular structural motif is lacking in GSTs that do not bind to the IMAC matrix. Creation of an equivalent His-His structure in the homologous human GST M1-1 by protein engineering afforded a mutant enzyme that displays affinity for Ni(II)-IDA-agarose, in contrast to the wild-type GST M1-1. The results identify a distinct site that is operational in IMAC and suggest an approach to the rational design of novel integral metal coordination sites in proteins. PMID:7831282

  16. An immobilized carboxyl containing metal-organic framework-5 stationary phase for open-tubular capillary electrochromatography.

    PubMed

    Bao, Tao; Tang, Pingxiu; Mao, Zhenkun; Chen, Zilin

    2016-07-01

    A novel capillary column with metal-organic framework-5 (MOF-5) as the stationary phase was prepared for open-tubular capillary electrochromatography (OT-CEC). To grow MOF-5, the fused-silica capillary was functionalized firstly using 3-aminopropyltriethoxysilane and glutaraldehyde as covalent linkers; and then MOF-5 would be immobilized on the inner wall of COOH-terminated capillary by epitaxial growth, to produce a MOF-5-modified capillary. The successful growth of MOF-5 has been characterized and confirmed by scanning electron microscopy, X-Ray diffraction and Fourier transform infrared spectra. The influence of pH value and methanol on electroosmotic flow (EOF) of the MOF-5-modified capillary column was investigated. The EOF showed a pH-dependent from anode to cathode. The immobilization of MOF-5 improved the interactions between analytes and layer on inner wall of the capillary. Excellent separations of substituted benzenes and acidic and basic analytes were obtained on the fabricated capillary columns. The MOF-5-modified capillary columns exhibited good repeatability, with relative standard deviations for intra-day, inter-day runs and column-to-column less than 1.87%, 3.53%, and 8.49%, respectively. Our successful application of MOF-5 paved the way for introducing series of dicarboxylate-based isoreticular MOFs to OT-CEC as novel stationary phase. PMID:27154687

  17. Novel voltammetric and impedimetric sensor for femtomolar determination of lysozyme based on metal-chelate affinity immobilized onto gold nanoparticles.

    PubMed

    Arabzadeh, Abbas; Salimi, Abdollah

    2015-12-15

    In this study, we reported iminodiacetic acid-copper ion complex (IDA-Cu) immobilized onto gold nanoparticles (GNPs)-modified glassy carbon electrode as a novel electrochemical platform for selective and sensitive determination of lysozyme (Lys). IDA-Cu complex acted as an efficient recognition element capable of capturing Lys molecules. GNPs acts as a substrate to immobilize IDA-Cu coordinative complex and its interaction with Lys leds to a great signal amplification through measuring changes in differential pulse voltammetric (DPV) peak current of [Fe(CN)6](3-/4-) redox probe. Upon the recognition of the Lys to the IDA-Cu, the peak current decreased due to the hindered electron transfer reaction on the electrode surface. Under optimum condition, it was found that the proposed method could detect Lys at wide linear concentration range (0.1 pM to 0.10 mM) with detection limit of 60 fM. Furthermore, electrochemical impedance spectroscopy (EIS) detection of Lys was demonstrated as a simple and rapid alternative analytical technique with detection limit of 80 fM at concentration range up to 0.1mM. In addition, the proposed sensor was satisfactorily applied to the determination of Lys in real samples such as hen egg white. The proposed modified electrode showing the high selectivity, good sensitivity and stability toward Lys detection may hold a great promise in developing other electrochemical sensors based on metal-chelate affinity complexes. PMID:26143467

  18. Purification of Hemoglobin from Red Blood Cells using Tangential Flow Filtration and Immobilized Metal Ion Affinity Chromatography

    PubMed Central

    Elmer, Jacob; Harris, David; Palmer, Andre F.

    2011-01-01

    Two methods for purifying hemoglobin (Hb) from red blood cells (RBCs) are examined and compared. In the first method, red blood cell lysate is clarified with a 50 nm tangential flow filter and hemoglobin is purified using immobilized metal ion affinity chromatography (IMAC). In the second method, RBC lysate is processed with 50 nm, 500 kDa, and 50-100 kDa tangential flow filters, then hemoglobin is purified with IMAC. Our results show that the hemoglobins from both processes produce identical Hb products that are ultrapure and retain their biophysical properties (except for chicken hemoglobin, which shows erratic oxygen binding behavior after purification). Therefore, the most efficient method for Hb purification appears to be clarification with a 50 nm tangential flow filter, followed by purification with IMAC, and sample concentration/polishing on a 10-50 kDa tangential flow filter. PMID:21195679

  19. Evaluation of immobilized metal affinity chromatography kits for the purification of histidine-tagged recombinant CagA protein.

    PubMed

    Karakus, Cebrail; Uslu, Merve; Yazici, Duygu; Salih, Barik A

    2016-05-15

    Immobilized metal affinity chromatography (IMAC) technique is used for fast and reliable purification of histidine(His)-tagged recombinant proteins. The technique provides purification under native and denaturing conditions. The aim of this study is to evaluate three commercially available IMAC kits (Thermo Scientific, GE Healthcare and Qiagen) for the purification of a 6xHis-tagged recombinant CagA (cytotoxin-associated gene A) protein from IPTG-induced Escherichia coli BL21(DE3) culture. The kits were tested according to the manufacturer instructions and the protein was purified with only GE Healthcare and Qiagen kits under denaturing conditions. 1% (w/v) SDS was used as denaturing agent in PBS instead of extraction reagent of Thermo Scientific kit to lyse bacterial cells from 100ml culture. The 6xHis-tagged recombinant protein was purified by the three kits equally. PMID:26657801

  20. Use of immobilized metal ions as a negative adsorbent for purification of enzymes: application to phosphoglycerate mutase from chicken muscle extract and horseradish peroxidase.

    PubMed

    Chaga, G; Andersson, L; Ersson, B; Berg, M

    1992-01-01

    Two enzymes, phosphoglycerate mutase and peroxidase, were purified by using an immobilized metal ion adsorbent for the removal of unwanted proteins. The mutase was obtained pure from a single column, whereas the purification of peroxidase required the use of a thiophilic adsorbent in a tandem. The capacity was 2.5 mg pure peroxidase per mL gel. PMID:1386542

  1. The role of authigenic sulfides in immobilization of potentially toxic metals in the Bagno Bory wetland, southern Poland.

    PubMed

    Smieja-Król, Beata; Janeczek, Janusz; Bauerek, Arkadiusz; Thorseth, Ingunn H

    2015-10-01

    The supply of Cd, Cu, Fe, Pb, Zn, and Tl into a wetland in the industrial area of Upper Silesia, southern Poland via atmospheric precipitation and dust deposition has been counterbalanced by the biogenic metal sulfide crystallization in microsites of the thin (<30 cm) peat layer, despite the overall oxidative conditions in the wetland. Disequilibrium of the redox reactions in the peat pore water (pH 5.4-6.2) caused by sulfate-reducing microorganisms has resulted in the localized decrease in Eh and subsequent precipitation of micron- and submicron-sized framboidal pyrite, spheroidal ZnS and (Zn,Cd)S, and galena as revealed by high-resolution scanning electron microscopy (SEM)/energy dispersive spectrometer (EDS). Saturation index for each sulfide is at a maximum within the calculated Eh range of -80 and -146 mV. Lead was also immobilized in galena deposited in fungal filaments, possibly at a higher Eh. Thallium (up to 3 mg kg(-1)) in the peat strongly correlates with Zn, whereas Cu (up to 55 mg kg(-1)) co-precipitated with Pb. The metal sulfides occur within microbial exudates, which protect them from oxidation and mechanical displacement. Vertical distribution of toxic metals in the peat layer reflects differences in pollution loads from atmospheric deposition, which has been much reduced recently. PMID:26006073

  2. Development of mathematical model for simulating biosorption of dissolved metals on Bacillus drentensis immobilized in biocarrier beads

    NASA Astrophysics Data System (ADS)

    Nam, J.; Wang, S.; Lee, M.

    2012-12-01

    Biocarrier beads with dead biomass, Bacillus drentensis, immobilized in polymer polysulfone were synthesized to remove heavy metals from wastewater. To identify the sorption mechanisms and theoretical nature of underlying processes, a series of batch experiments were carried out and a mathematical model was developed to quantify the biosorption of Pb(II) and Cu(II) by the biocarrier beads. A series of mass balance equations for representing mass transfer of metal sorbents in a biocarrier beads and surrounding solution were established and solved using a finite difference method. Major model parameters such as external mass transfer coefficient and maximum sorption capacity, etc. were determined from pseudo-first and second-order kinetic models and Langmuir isotherm model based on kinetic and equilibrium experimental measurements. The model simulation displays reasonable representations of experimental data and implied that the proposed model can be applied to quantitative analysis on biosorption mechanisms by porous granular beads. The simulation results also confirms that the biosorption of heavy metal by the biocarrier beads largely depended on surface adsorption.

  3. Exploiting metal-organic coordination polymers as highly efficient immobilization matrixes of enzymes for sensitive electrochemical biosensing.

    PubMed

    Fu, Yingchun; Li, Penghao; Bu, Lijuan; Wang, Ting; Xie, Qingji; Chen, Jinhua; Yao, Shouzhuo

    2011-09-01

    We report on the exploitation of metal-organic coordination polymers (MOCPs) as new and efficient matrixes to immobilize enzymes for amperometric biosensing of glucose or phenols. A ligand, 2,5-dimercapto-1,3,4-thiadiazole (DMcT), two metallic salts, NaAuCl(4) and Na(2)PtCl(6), and two enzymes, glucose oxidase (GOx) and tyrosinase, are used to demonstrate the novel concept. Briefly, one of the metallic salts is added into an aqueous suspension containing DMcT and one of the enzymes to trigger the metal-organic coordination reaction, and the yielded MOCPs-enzyme biocomposite (MEBC) is then cast-coated on an Au electrode for biosensing. The aqueous-phase coordination polymerization reactions of the metallic ions with DMcT are studied by visual inspection as well as some spectroscopic, microscopic, and electrochemical methods. The thus-prepared glucose and phenolic biosensors perform better in analytical performance (such as sensitivity and limit of detection) than those prepared by the conventional chemical and/or electrochemical polymerization methods and most of the reported analogous biosensors, as a result of the improved enzyme load/activity and mass-transfer efficiency after using the MOCPs materials with high adsorption/encapsulation capability and unique porous structure. For instance, the detection limit for catechol is as low as 0.2 nM here, being order(s) lower than those of most of the reported analogues. The enzyme electrode was also used to determine catachol in real samples with satisfactory results. The emerging MOCPs materials and the suggested aqueous-phase preparation strategy may find wide applications in the fields of bioanalysis, biocatalysis, and environmental monitoring. PMID:21780824

  4. Ancient concept of metal pharmacology based on Ayurvedic literature.

    PubMed

    Sarkar, Prasanta Kumar; Das, Sanjita; Prajapati, P K

    2010-04-01

    Metals have had a long history in Ayurvedic system of medicine. Mercury (Parada), gold (Swarna), silver (Rajata), copper (Tamra), iron (Lauha), tin (Vanga), lead (Naga), and zinc (Yasada) are used in therapeutics in an incinerated (Bhasma) form. The pharmacological actions, therapeutic indications, adverse effects and management of adverse effects of these metals are described and emphasis has been given to the proper preparation, rational dose and duration during clinical practice in the classics of Ayurveda. Most important observation is, there are no contraindications of these Bhasmas, indicating universal applicability to all age levels with suitable adjuvant, proper dose and duration. PMID:22557360

  5. Ancient concept of metal pharmacology based on Ayurvedic literature

    PubMed Central

    Sarkar, Prasanta Kumar; Das, Sanjita; Prajapati, P. K.

    2010-01-01

    Metals have had a long history in Ayurvedic system of medicine. Mercury (Parada), gold (Swarna), silver (Rajata), copper (Tamra), iron (Lauha), tin (Vanga), lead (Naga), and zinc (Yasada) are used in therapeutics in an incinerated (Bhasma) form. The pharmacological actions, therapeutic indications, adverse effects and management of adverse effects of these metals are described and emphasis has been given to the proper preparation, rational dose and duration during clinical practice in the classics of Ayurveda. Most important observation is, there are no contraindications of these Bhasmas, indicating universal applicability to all age levels with suitable adjuvant, proper dose and duration. PMID:22557360

  6. Biochar- and phosphate-induced immobilization of heavy metals in contaminated soil and water: implication on simultaneous remediation of contaminated soil and groundwater.

    PubMed

    Liang, Yuan; Cao, Xinde; Zhao, Ling; Arellano, Eduardo

    2014-03-01

    Long-term wastewater irrigation or solid waste disposal has resulted in the heavy metal contamination in both soil and groundwater. It is often separately implemented for remediation of contaminated soil or groundwater at a specific site. The main objective of this study was to demonstrate the hypothesis of simultaneous remediation of both heavy metal contaminated soil and groundwater by integrating the chemical immobilization and pump-and-treat methods. To accomplish the objective, three experiments were conducted, i.e., an incubation experiment was first conducted to determine how dairy-manure-derived biochar and phosphate rock tailing induced immobilization of Cd in the Cd-contaminated soils; second, a batch sorption experiment was carried out to determine whether the pre-amended contaminated soil still had the ability to retain Pb, Zn and Cd from aqueous solution. BCR sequential extraction as well as XRD and SEM analysis were conducted to explore the possible retention mechanism; and last, a laboratory-scale model test was undertaken by leaching the Pb, Zn, and Cd contaminated groundwater through the pre-amended contaminated soils to demonstrate how the heavy metals in both contaminated soil and groundwater were simultaneously retained and immobilized. The incubation experiment showed that the phosphate biochar were effective in immobilizing soil Cd with Cd concentration in TCLP (toxicity characteristics leaching procedure) extract reduced by 19.6 % and 13.7 %, respectively. The batch sorption experiment revealed that the pre-amended soil still had ability to retain Pb, Zn, and Cd from aqueous solution. The phosphate-induced metal retention was mainly due to the metal-phosphate precipitation, while both sorption and precipitation were responsible for the metal stabilization in the biochar amendment. The laboratory-scale test demonstrated that the soil amended with phosphate removed groundwater Pb, Zn, and Cd by 96.4 %, 44.6 %, and 49.2 %, respectively, and the

  7. Remediation of Heavy Metal(loid)s Contaminated Soils – To Mobilize or To Immobilize?

    EPA Science Inventory

    Unlike organic contaminants, metal(loid)s do not undergo microbial or chemical degradation and persist for a long time after their introduction. Bioavailability of metal(loid)s plays a vital role in the remediation of contaminated soils. In this review, the remediation of heavy ...

  8. Literature review on the use of bioaccumulation for heavy metal removal and recovery

    SciTech Connect

    Benemann, J.R. , Pinole, CA ); Wilde, E.W. )

    1991-02-01

    Bioaccumulation of metals by microbes -- bioremoval'' -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes.

  9. Literature review on the use of bioaccumulation for heavy metal removal and recovery. Volume 2

    SciTech Connect

    Benemann, J.R.; Wilde, E.W.

    1991-02-01

    Bioaccumulation of metals by microbes -- `` bioremoval`` -- is a powerful new technology for the concentration, recovery, and removal of toxic heavy metals and radionuclides from waste streams and contaminated environments. Algae are particularly well suited for metal bioremoval. A recent commercial application of bioremoval utilizes inert (dead) immobilized microalgae biomass as ion exchange materials for the removal of heavy metals from industrial waste waters. Also, living microalgal cultures have been used to remove metals from mine effluents. Microbial cells and biomass can bioaccumulate metals and radionuclides by a large variety of mechanisms, both dependent and independent of cell metabolism. Microbial cell walls can act as ion exchange and metal complexation agents. Heavy metals can precipitate and even crystallize on cell surfaces. Metabolically produced hydrogen sulfide or other metabolic products can bioprecipitate heavy metals. Many microbes produce both intra- and extracellular metal complexing agents which could be considered in practical metal removal processes. Bioremoval processes are greatly affected by the microbial species and even strain used, pH, redox potential, temperature, and other conditions under which the microbes are grown. Development of practical applications of bioremoval requires applies research using the particular waste solutions to be treated, or close simulations thereof. From a practical perspective, the selection of the microbial biomass and the process for contacting the microbial biomass with the metal containing solutions are the key issues. Much of the recent commercial R&D has emphasized commercially available, inert, microbial biomass sources as these can be acquired in sufficient quantities at affordable costs. The fundamental research and practical applications of bioaccumulation by microalgae suggests these organisms warrant a high priority in the development of advanced bioremoval processes.

  10. Synergistic effects of plant growth-promoting Neorhizobium huautlense T1-17 and immobilizers on the growth and heavy metal accumulation of edible tissues of hot pepper.

    PubMed

    Chen, Ling; He, Lin-Yan; Wang, Qi; Sheng, Xia-Fang

    2016-07-15

    A plant growth-promoting Neorhizobium huautlense T1-17 was evaluated for its immobilization of Cd and Pb in solution. Meanwhile, the impacts of T1-17, immobilizers (vermiculite and peat) and their combination on the fruit biomass and heavy metal accumulation of hot pepper were characterized. T1-17 could significantly reduced water-soluble Cd and Pb in solution. T1-17, vermiculite+T1-17, peat, and peat+T1-17 significantly increased the fruit biomass (ranging from 45% to 269%) and decreased the fruit Cd (ranging from 66% to 87%) and Pb (ranging from 30% to 56%) contents and water-soluble Cd and Pb (ranging from 23% to 59%) contents of the rhizosphere soils compared to the controls. T1-17+vermiculite or peat had higher ability to increase the fruit biomass than T1-17 or vermiculite or peat. Furthermore, T1-17+peat had higher ability to reduce the water-soluble Cd and Pb contents of the rhizosphere soil and the fruit Pb uptake of hot pepper. The results showed that T1-17 and the immobilizers alleviated the heavy metal toxicity and decreased the fruit heavy metal uptake of hot pepper. The results also showed the synergistic effects of T1-17 and the immobilizers on the growth and Cd and Pb accumulation of hot pepper. PMID:27017398

  11. Immobilization of heavy metals by Pseudomonas putida CZ1/goethite composites from solution.

    PubMed

    Chen, XinCai; Chen, LiTao; Shi, JiYan; Wu, WeiXiang; Chen, YingXu

    2008-02-15

    Bacterial-mineral composites are important in the retention of heavy metals due to their large sorption capacity under a wide range of environmental conditions. This study provides the first quantitative comparison of the metal-binding capacities of P. putida CZ1-goethite composite to its individual components. When the same amount (on a dry weight basis) of living and nonliving cells of P. putida CZ1, goethite or their composites was separately exposed to solutions of 0.5 mM Cu(II) and Zn(II) in 0.01 M KNO(3), the living cells removed the largest quantity of heavy metals. The results of calculated metal retention values indicated that the adsorption of goethite to bacteria has not mask or neutralize chemically reactive adsorption sites normally available to metal ions. Moreover, the nonliving cells-goethite composite retained approximately 82% more Zn than that predicted by their individual behavior. The preferential association of Zn with P. putida CZ1 was observed by TEM and EDS analyses of a mixture consisting of the bacteria and goethite. Desorption of Cu and Zn with 1.0M CH(3)COOK solution from P. putida CZ1 and goethite indicated the differences in the functional groups able to bind heavy metals. PMID:17869490

  12. Olive mill waste biochar: a promising soil amendment for metal immobilization in contaminated soils.

    PubMed

    Hmid, Amine; Al Chami, Ziad; Sillen, Wouter; De Vocht, Alain; Vangronsveld, Jaco

    2015-01-01

    The potential use of biochar from olive mill waste for in situ remediation of metal contaminated soils was evaluated. Biochar was mixed with metal contaminated soil originating from the vicinity of an old zinc smelter. Soil-biochar mixtures were equilibrated for 30 and 90 days. At these time points, Ca(NO3)2 exchangeable metals were determined, and effects of the biochar amendment on soil toxicity were investigated using plants, bacteria, and earthworms. Bean (Phaseolus vulgaris) growth, metal content, antioxidative enzymes activities, and soluble protein contents were determined. Furthermore, effects on soil microbial communities (activity, diversity, richness) were examined using Biolog ECOplates. After 120 days of soil-biochar equilibration, effects on weight and reproduction of Eisenia foetida were evaluated. With increasing biochar application rate and equilibration period, Ca(NO3)2 exchangeable metals decreased, and growth of bean plants improved; leaf metal contents reduced, the activities of antioxidative stress enzymes decreased, and soluble protein contents increased. Soil microbial activity, richness, and diversity were augmented. Earthworm mortality lowered, and their growth and reproduction showed increasing trends. PMID:25146122

  13. Microfoams as Reactant Transport Media for In-Situ Immobilization of Radionuclide and Metallic Contaminants in Deep Vadose Zone

    NASA Astrophysics Data System (ADS)

    Wellman, D. M.; Zhong, L.; Mattigod, S.; Jansik, D.

    2009-12-01

    The U.S. Department of Energy (DOE) is currently addressing issues related to remediation of Cr, U and Tc contamination in the deep vadose zone at the Hanford Site in Washington State. One of the transformational technology alternatives being considered by the DOE Office of Environmental Management, is the use of Reactant Carrier Microfoams (RCM) for in-situ immobilization of contaminants. Foam injection technology for Enhance Oil Recovery (EOR) has well-established pedigree. Use of surfactant foams have also been explored for mobilizing DNAPL from sediments. However, the novel concept of using RCM for in situ immobilization contaminants in the deep vadose zone has not been explored, therefore, presents many daunting challenges for successful implementation. Scienists at Pacific Northwest National Laboratory (PNNL), leveraged previous EMSP-funded studies on microfoams conducted at LBNL with the goal to formulate robust stable microfoams for delivering reductive and/or precipitating reactants to the deep subsurface. Following an extensive literature review, a protocol was deisnged to select appropriate surfactant blends, and tested three different methods of foam generation namely, Venturi foam generato , high-speed gas entrainment and porous plate method. The resulting RCMs were characterized as to their quality, stability, bubble size distribution, surface tension and viscosity. The foam stabilities as a function of reactant (polyphosphate and polysulfides) concentrations and entrained polyatomic gases were also examined. Based on these experiments, optimal carrier foam compositions were identified for each Hanford deep vadose zone Contaminant of Concern (COC) namely U(VI) and Cr(VI). Finally, MSE Technology Applications, Inc (MSE) in collaboration with PNNL, conducted a series of scale-up reactant carrier foam injection tests to evaluate the efficacy of this technology for potential deep vadose zone remediation.

  14. Purification of His6-organophosphate hydrolase using monolithic supermacroporous polyacrylamide cryogels developed for immobilized metal affinity chromatography.

    PubMed

    Efremenko, E; Votchitseva, Y; Plieva, F; Galaev, I; Mattiasson, B

    2006-05-01

    Organophosphate hydrolase containing hexahistidine tag at the N-terminus of recombinant protein (His6-OPH) and expressed in Escherichia coli cells was purified using supermacroporous polyacrylamide-based monolith columns with immobilized metal affinity matrices [Me2+-iminodiacetic acid (IDA)-polyacrylamide cryogel (PAA) and Me2+-N,N,N'-tris (carboxymethyl) ethylendiamine (TED)-PAA]. Enzyme preparation with 50% purity was obtained by direct chromatography of nonclarified cell homogenate, whereas the combination of addition of 10 mM imidazole to buffers for cell sonication and sample loading, the use of precolumn with IDA-PAA matrix noncharged with metal ions, and the application of high flow rate provided the 99% purity of enzyme isolated directly from crude cell homogenate. Co2+-IDA-PAA provided the highest level of selectivity for His6-OPH. Comparative analysis of purification using Co2+-IDA-PAA and Ni-nitrilotriacetic acid-agarose showed obvious advantages of the former in process time, specific activity of purified enzyme, and simplicity of adsorbent regeneration. PMID:16088350

  15. Immobilized Metal Affinity Chromatography Co-Purifies TGF-β1 with Histidine-Tagged Recombinant Extracellular Proteins

    PubMed Central

    Kaur, Jasvir; Reinhardt, Dieter P.

    2012-01-01

    Extracellular recombinant proteins are commonly produced using HEK293 cells as histidine-tagged proteins facilitating purification by immobilized metal affinity chromatography (IMAC). Based on gel analyses, this one-step purification typically produces proteins of high purity. Here, we analyzed the presence of TGF-β1 in such IMAC purifications using recombinant extracellular fibrillin-1 fragments as examples. Analysis of various purified recombinant fibrillin-1 fragments by ELISA consistently revealed the presence of picomolar concentrations of active and latent TGF-β1, but not of BMP-2. These quantities of TGF-β1 were not detectable by Western blotting and mass spectrometry. However, the amounts of TGF-β1 were sufficient to consistently trigger Smad2 phosphorylation in fibroblasts. The purification mechanism was analyzed to determine whether the presence of TGF-β1 in these protein preparations represents a specific or non-specific co-purification of TGF-β1 with fibrillin-1 fragments. Control purifications using conditioned medium from non-transfected 293 cells yielded similar amounts of TGF-β1 after IMAC. IMAC of purified TGF-β1 and the latency associated peptide showed that these proteins bound to the immobilized nickel ions. These data clearly demonstrate that TGF-β1 was co-purified by specific interactions with nickel, and not by specific interactions with fibrillin-1 fragments. Among various chromatographic methods tested for their ability to eliminate TGF-β1 from fibrillin-1 preparations, gel filtration under high salt conditions was highly effective. As various recombinant extracellular proteins purified in this fashion are frequently used for experiments that can be influenced by the presence of TGF-β1, these findings have far-reaching implications for the required chromatographic schemes and quality controls. PMID:23119075

  16. Influence of biofilms on heavy metal immobilization in sustainable urban drainage systems (SuDS).

    PubMed

    Feder, Marnie; Phoenix, Vernon; Haig, Sarah; Sloan, William; Dorea, Caetano; Haynes, Heather

    2015-01-01

    This paper physically and numerically models the influence of biofilms on heavy metal removal in a gravel filter. Experimental flow columns were constructed to determine the removal of Cu, Pb and Zn by gabbro and dolomite gravel lithologies with and without natural biofilm from sustainable urban drainage systems (SuDS). Breakthrough experiments showed that, whilst abiotic gravel filters removed up to 51% of metals, those with biofilms enhanced heavy metal removal by up to a further 29%, with Cu removal illustrating the greatest response to biofilm growth. An advection-diffusion equation successfully modelled metal tracer transport within biofilm columns. This model yielded a permanent loss term (k) for metal tracers of between 0.01 and 1.05, correlating well with measured data from breakthrough experiments. Additional 16S rRNA clone library analysis of the biofilm indicated strong sensitivity of bacterial community composition to the lithology of the filter medium, with gabbro filters displaying Proteobacteria dominance (54%) and dolomite columns showing Cyanobacteria dominance (47%). PMID:25982923

  17. IMMOBILIZATION OF HEAVY METALS IN SOILS AND WATER BY A MANGANESE MINERAL

    EPA Science Inventory

    A synthesized Mn mineral used in study on adsorption of heavy metals from water has shown a great adsorption capability for Pb, Cu, Cd, Co, Ni and Zn on this mineral over a pH range from 2 to 8. The retention of Pb on this mineral was as high as 10% of its weight. Application of ...

  18. Use of wastewater ER sludges for the immobilization of heavy metals

    SciTech Connect

    Macha, S.; Murray, D.; Urasa, I.T.

    1996-10-01

    The distribution, mobility, and bioavailability of heavy metals in soils, surface water, and ground water have been of major interest and concern from both environmental and geochemical standpoints. Wastewater sludges represent an important anthropogenic factor whose impact on these processes is not fully understood. In the past, incineration and landfilling were common practices for discarding wastewater sludges. However, as local and state laws governing the disposal of these materials have become more stringent, land application has been used as an alternative. Reported studies have shown that the impact of land application of sludges can vary widely and is influenced by a number of factors, including the source of the sludge; the organic matter content of the sludge; the form in which the sludge is applied; and the prevailing conditions of the receiving soils. It has also been shown that sewage sludge can have solubilizing effects on solid-phase heavy metals, thereby causing geochemical shifts of the insoluble fractions of metals to the more soluble forms. The work presented in this paper utilized synthetic minerals, standard solutions, sludges, and agricultural soils obtained from different sources to determine the mechanisms involved in the mineralization of heavy metals by sludge; the influence of soil conditions; interelemental effects; the influence of natural organic matter; and possible microbial activity that may come into play. Several types of sludge were evaluated for lead binding capacity.

  19. Use of alum water treatment sludge to stabilize C and immobilize P and metals in composts.

    PubMed

    Haynes, R J; Zhou, Y-F

    2015-09-01

    Alum water treatment sludge is composed of amorphous hydroxyl-Al, which has variable charge surfaces with a large Brunauer-Emmett-Teller (BET) surface area (103 m(-2) g(-1)) capable of specific adsorption of organic matter molecules, phosphate, and heavy metals. The effects of adding dried, ground, alum water treatment sludge (10% w/w) to the feedstock for composting municipal green waste alone, green waste plus poultry manure, or green waste plus biosolids were determined. Addition of water treatment sludge reduced water soluble C, microbial biomass C, CO2 evolution, extractable P, and extractable heavy metals during composting. The decrease in CO2 evolution (i.e., C sequestration) was greatest for poultry manure and least for biosolid composts. The effects of addition of water treatment sludge to mature green waste-based poultry manure and biosolid composts were also determined in a 24-week incubation experiment. The composts were either incubated alone or after addition to a soil. Extractable P and heavy metal concentrations were decreased by additions of water treatment sludge in all treatments, and CO2 evolution was also reduced from the poultry manure compost over the first 16-18 weeks. However, for biosolid compost, addition of water treatment sludge increased microbial biomass C and CO2 evolution rate over the entire 24-week incubation period. This was attributed to the greatly reduced extractable heavy metal concentrations (As, Cr, Cu, Pb, and Zn) present following addition of water treatment sludge, and thus increased microbial activity. It was concluded that addition of water treatment sludge reduces concentrations of extractable P and heavy metals in composts and that its effect on organic matter stabilization is much greater during the composting process than for mature compost because levels of easily decomposable organic matter are initially much higher in the feedstock than those in matured composts. PMID:25948380

  20. Literature.

    ERIC Educational Resources Information Center

    Verner, Zenobia, Ed.

    1977-01-01

    This issue provides a selection of articles about literature and the teaching of literature. Titles include "Sin, Salvation, and Grace in 'The Scarlet Letter,'""'The Road Not Taken': A Study in Ambiguity,""In Search of Shakespeare: The Essential Years,""Right Deeds for Wrong Reasons: Teaching the Bible as Literature,""A Southern Author's Fight for…

  1. Liquid crystal-based sensors for the detection of heavy metals using surface-immobilized urease.

    PubMed

    Hu, Qiong-Zheng; Jang, Chang-Hyun

    2011-12-01

    In this study, a new method for the detection of heavy metals in aqueous phase was developed using liquid crystals (LCs). When UV-treated nematic LC, 4-cyano-4'-pentyl biphenyl (5CB) that was confined in the urease-modified gold grid was immersed in a urea solution, an optical response from bright to dark was observed under a polarized microscope, indicating that a planar-to-homeotropic orientational transition of the LC occurred at the aqueous/LC interface. Since urease hydrolyzes urea to produce ammonia, which would be ionized into ammonium and hydroxide ions, the main product of the photochemically degraded 5CB, 4-cyano-4'-biphenylcarboxylic acid (CBA), was deprotonated and self-assembled at the interface, inducing the orientational transition in the LC. Due to the high sensitivity and rapid response of this system, detection of heavy metal ions was further exploited. The divalent copper ion, which could effectively inhibit the activity of urease, was used as a model heavy metal ion. The optical appearance of the LC did not change when urea was in contact with the copper nitrate hydrate-blocked urease. After the copper-inhibited urease was reactivated by EDTA, a bright-to-dark shift in the optical signal was regenerated, indicating an orientational transition of the LC. This type of LC-based sensor shows high spatial resolution due to its optical characteristics and therefore could potentially be used to accurately monitor the presence of enzyme inhibitors such as heavy metal ions in real-time. PMID:21846586

  2. Immobilized chiral tropine ionic liquid on silica gel as adsorbent for separation of metal ions and racemic amino acids.

    PubMed

    Qian, Guofei; Song, Hang; Yao, Shun

    2016-01-15

    Tropine-type chiral ionic liquid with proline anion was immobilized on silica gel by chemical modification method for the first time, which was proved by elemental, infrared spectrum and thermogravimetric analysis. Secondly, the performance of this kind of ionic liquid-modified silica gel was investigated in the adsorption of some metal ions, which included Cu(2+), Fe(3+), Mn(2+) and Ni(2+). Then the effects of time, initial concentration and temperature on adsorption for Cu(2+) ions were studied in detail, which was followed by the further research of adsorption kinetics and thermodynamics. The adsorption could be better described by pseudo-second-order kinetics model and that the process was spontaneous, exothermic and entropy decreasing. In the mode of 'reuse after adsorption', the ionic liquid-modified silica gel with saturated adsorption of Cu(2+) was finally used in resolution of racemic amino acids for the first time. The static experiment showed that adsorption rate of two enantiomers was obviously different. Inspired by this, the complex was packed in chromatographic column for the separation of racemic amino acids and d-enantiomers were firstly eluted by water or ethanol. Steric hindrance was found as one of key influencing factors for its effect on the stability of the complex. PMID:26711153

  3. Engineered Natural Geosorbents for In Situ Immobilization of DNAPLs and Heavy Metals

    SciTech Connect

    Walter J. Weber; Gordon M. Fair; Earnest Boyce

    2006-12-01

    Extensive subsurface contamination by dense non-aqueous phase liquid (DNAPL) organic solvents and heavy metals is common place at many DOE facilities. Poor performances and excessive costs have made traditional technologies and approaches less than satisfactory for remediation of such sites. It is increasingly apparent that marginal improvements in conventional methods and approaches will not suffice for clean up of many contaminated DOE sites. Innovative approaches using new and/or existing technologies in more efficient and cost-effective ways are thus urgently required.

  4. Gold nanoparticles immobilized on metal-organic frameworks with enhanced catalytic performance for DNA detection.

    PubMed

    Liu, Ya Li; Fu, Wen Liang; Li, Chun Mei; Huang, Cheng Zhi; Li, Yuan Fang

    2015-02-25

    In this work, gold nanoparticles (AuNPs) assembled on the surface of iron based metal-organic frameworks (MOFs), Fe-MIL-88, are facilely prepared through electrostatic interactions using polyethyleneimine (PEI) molecules as linker. The resulting hybrid materials possess synergetic peroxidase-like activity. Because iron based metal-organic frameworks, Fe-MIL-88, exhibits highly peroxidase-like activity, and AuNPs has the distinct adsorption property to single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). The peroxidase-like activity of Au@Fe-MIL-88 exhibit excellent switchable in response to specific DNA, ssDNA is easily adsorbed on the surface of the Au@Fe-MIL-88 hybrids, resulting in the reduce of the peroxidase-like activity of the hybrids. While it is recovered by the addition of target DNA, and the recovery degree is proportional to the target DNA concentration over the range of 30-150 nM with a detection limit of 11.4 nM. Based on these unique properties, we develop a label-free colorimetric method for DNA hybridization detection. In control experiment, base-mismatched DNA cannot induce recovery of the peroxidase-like activity. This detection method is simple, cheap, rapid and colorimetric. PMID:25702274

  5. Immobilization of metal-humic acid complexes in anaerobic granular sludge for their application as solid-phase redox mediators in the biotransformation of iopromide in UASB reactors.

    PubMed

    Cruz-Zavala, Aracely S; Pat-Espadas, Aurora M; Rangel-Mendez, J Rene; Chazaro-Ruiz, Luis F; Ascacio-Valdes, Juan A; Aguilar, Cristobal N; Cervantes, Francisco J

    2016-05-01

    Metal-humic acid complexes were synthesized and immobilized by a granulation process in anaerobic sludge for their application as solid-phase redox mediators (RM) in the biotransformation of iopromide. Characterization of Ca- and Fe-humic acid complexes revealed electron accepting capacities of 0.472 and 0.556milli-equivalentsg(-1), respectively. Once immobilized, metal-humic acid complexes significantly increased the biotransformation of iopromide in upflow anaerobic sludge blanket (UASB) reactors. Control UASB reactor (without humic material) achieved 31.6% of iopromide removal, while 80% was removed in UASB reactors supplied with each metal-humic acid complex. Further analyses indicated multiple transformation reactions taking place in iopromide including deiodination, N-dealkylation, decarboxylation and deacetylation. This is the first successful application of immobilized RM, which does not require a supporting material to maintain the solid-phase RM in long term operation of bioreactors. The proposed redox catalyst could be suitable for enhancing the redox conversion of different recalcitrant pollutants present in industrial effluents. PMID:26868154

  6. Bio-inspired immobilization of metal oxides on monolithic microreactor for continuous Knoevenagel reaction.

    PubMed

    Song, Wentong; Shi, Da; Tao, Shengyang; Li, Zhaoliang; Wang, Yuchao; Yu, Yongxian; Qiu, Jieshan; Ji, Min; Wang, Xinkui

    2016-11-01

    A facile method is reported to construct monolithic microreactor with high catalytic performance for Knoevenagel reaction. The microreactor is based on hierarchically porous silica (HPS) which has interconnected macro- and mesopores. Then the HPS is surface modified by pyrogallol (PG) polymer. Al(NO3)3 and Mg(NO3)2 are loaded on the surface of HPS through coordination with -OH groups of PG. After thermal treatment, Al(NO3)3 and Mg(NO3)2 are converted Al2O3 and MgO. The as-synthesized catalytic microreactor shows a high and stable performance in Knoevenagel reaction. The microreactor possess large surface area and interconnected pore structures which are beneficial for reactions. Moreover, this economic, facile and eco-friendly surface modification method can be used in loading more metal oxides for more reactions. PMID:27459172

  7. Characterization of aquatic humic substances and their metal complexes by immobilized metal-chelate affinity chromatography on iron(III)-loaded ion exchangers.

    PubMed

    Burba, P; Jakubowski, B; Kuckuk, R; Küllmer, K; Heumann, K G

    2000-12-01

    The analytical fractionation of aquatic humic substances (HS) by means of immobilized metal-chelate affinity chromatography (IMAC) on metal-loaded chelating ion exchangers is described. The cellulose HYPHAN, loaded with different trivalent ions, and the chelate exchanger Chelex 100, loaded to 90% of its capacity with Fe(III), were used. The cellulose HYPHAN, loaded with 2% Fe(III), resulted in HS distribution coefficients Kd of up to 10(3.7) mL/g at pH 4.0 continuously decreasing down to 10(1.5) at pH 12, which were appropriate for HS fractionation by a pH-depending chromatographic procedure. Similar distribution coefficients Kd were obtained for HS sorption onto Fe(III)-loaded Chelex 100. On the basis of Fe-loaded HYPHAN both, a low-pressure and high-pressure IMAC technique, were developed for the fractionation of dissolved HS applying a buffer-based pH gradient for their gradual elution between pH 4.0 and 12.0. By coupling the Chelex 100 column under high-pressure conditions with an inductively coupled plasma mass spectrometer an on-line characterization of HS metal species could be achieved. Using these fractionation procedures a number of reference HS were characterized. Accordingly, the HA (humic acids) and FA (fulvic acids) studied could be discriminated into up to 6 fractions by applying cellulose HYPHAN, significantly differing in their Cu(II) complexation capacity but hardly in their substructures assessed by conventional FTIR. In the case of using Chelex 100 exchanger resin two major UV active HS fractions were obtained, which significantly differ in their complexation properties for Cu(II) and Pb(II), respectively. PMID:11227549

  8. Facile preparation of an immobilized surfactant-free palladium nanocatalyst for metal hydride trapping: a novel sensing platform for TXRF analysis.

    PubMed

    Romero, V; Costas-Mora, I; Lavilla, I; Bendicho, C

    2015-02-01

    In this work, a simple route for the synthesis of surfactant-free immobilized palladium nanoparticles (Pd NPs) and their use as effective nanocatalysts for metal hydride decomposition is described. A mixture of ethanol : water was used as the reducing agent. Ethanol was added in a large excess to reduce the ionic Pd and stabilize the obtained Pd NPs. Ethanol is adsorbed on the surface of Pd allowing steric stabilization. Freshly prepared Pd NPs were immobilized onto quartz substrates modified with 3-mercaptopropyltrimethoxysilane. Pd interacts with the thiol group of the alkoxysilane that is adsorbed on the surface of NPs without the dissociation of the S-H bond. Different parameters affecting the synthesis of Pd NPs and their immobilization onto quartz substrates were evaluated. A comprehensive characterization of the synthesized Pd NPs was carried out by transmission electron microscopy (TEM), whereas total reflection X-ray fluorescence (TXRF) spectrometry was applied in order to evaluate their catalytic activity for solid-gas reactions. Immobilized Pd NPs were applied as nanocatalysts for the dissociative chemisorption of arsine at room temperature, yielding the formation of As-Pd bonds. Quartz substrates coated with nanosized Pd could be used as novel sensing platforms for total reflection X-ray fluorescence analysis. Arsenic can be detected in situ in natural water with a limit of detection of 0.08 μg L(-1). PMID:25536926

  9. Hydrophilic Nb⁵⁺-immobilized magnetic core-shell microsphere--A novel immobilized metal ion affinity chromatography material for highly selective enrichment of phosphopeptides.

    PubMed

    Sun, Xueni; Liu, Xiaodan; Feng, Jianan; Li, Yan; Deng, Chunhui; Duan, Gengli

    2015-06-23

    Rapid and selective enrichment of phosphopeptides from complex biological samples is essential and challenging in phosphorylated proteomics. In this work, for the first time, niobium ions were directly immobilized on the surface of polydopamine-coated magnetic microspheres through a facile and effective synthetic route. The Fe3O4@polydopamine-Nb(5+) (denoted as Fe3O4@PD-Nb(5+)) microspheres possess merits of high hydrophilicity and good biological compatibility, and demonstrated low limit of detection (2 fmol). The selectivity was also basically satisfactory (β-casein:BSA=1:500) to capture phosphopeptides. They were also successfully applied for enrichment of phosphopeptides from real biological samples such as human serum and nonfat milk. Compared with Fe3O4@PD-Ti(4+) microspheres, the Fe3O4@PD-Nb(5+) microspheres exhibit superior selectivity to multi-phosphorylated peptides, and thus may be complementary to the conventional IMAC materials. PMID:26092339

  10. Immobilization of toxic metals and radionuclides in porous and fractured media: Optimizing biogeochemical reduction versus geochemical oxidation. 1997 annual progress report

    SciTech Connect

    Jardine, P.M.; Brooks, S.C.; Saiers, J.E.; Phelps, T.J.; Zachara, J.; Fendorf, S.E.

    1997-09-01

    'The purpose of the authors research is to provide an improved understanding and predictive capability of the mechanisms that allow metal-reducing bacteria to be effective in the bioremediation of subsurface environments contaminated with toxic metals and radionuclides. The research findings of the work plan will (1) provide new insights into the previously unexplored areas of competing geochemical and microbiological oxidation/reduction reactions that govern the fate and transport of redox sensitive contaminants in subsurface environments and (2) provide basic knowledge to define the optimum conditions for the microbial reduction and concomitant immobilization of toxic metals and radionuclides in the subsurface. Strategies that use in situ contaminant immobilization can be efficient and cost-effective remediation options. This project will focus on the following specific objectives. Develop an improved understanding of the rates and mechanisms of competing geochemical and microbiological oxidation/reduction reactions that govern the fate and transport of uranium (U), chromium (Cr), and cobalt-EDTA (Co-EDTA) in the subsurface. Quantify the conditions that optimize the microbial reduction of toxic metals and radionuclides for the purpose of contaminant containment and remediation in heterogeneous systems that have competing geochemical oxidation, sorption, and organic ligands.'

  11. Immobilized metal ion affinity chromatography ZipTip pipette tip with polydopamine modification and Ti⁴⁺ immobilization for selective enrichment and isolation of phosphopeptides.

    PubMed

    Shi, Chenyi; Deng, Chunhui

    2015-10-01

    As an effective tool in protein analysis, mass spectroscopy (MS) has been widely used in identifying protein phosphorylation and phosphorylation sites. Because of the low abundance of phosphopeptides in protein digestion, isolation and enrichment of phosphopeptides prior to MS analysis is important for efficient phosphopeptides identification. In this work, we initially immobilized titanium ions on polydopamine (PDA)-modified ZipTip pipette tips (denoted as IMAC ZipTip pipette tip) for simple and quick enrichment of phosphopeptides. The preparation process of the novel ZipTip pipette tips is fast and economic since it only contains two simple steps both with mild conditions. The ability of modified ZipTip pipette tips for identifying phosphopeptides in complex biological samples was investigated. The unique ZipTip pipette tip not only exhibited superior ability in selectively capturing phosphopeptides from large amount of non-phosphopeptides, but also remarkably shortened the MS preparation and analysis time, making it an easy-to-use and efficient tool in phosphoproteome research. PMID:26078185

  12. Plutonium Immobilization Puck Handling

    SciTech Connect

    Kriikku, E.

    1999-01-26

    The Plutonium Immobilization Project (PIP) will immobilize excess plutonium and store the plutonium in a high level waste radiation field. To accomplish these goals, the PIP will process various forms of plutonium into plutonium oxide, mix the oxide powder with ceramic precursors, press the mixture into pucks, sinter the pucks into a ceramic puck, load the pucks into metal cans, seal the cans, load the cans into magazines, and load the magazines into a Defense Waste Processing Facility (DPWF) canister. These canisters will be sent to the DWPF, an existing Savannah River Site (SRS) facility, where molten high level waste glass will be poured into the canisters encapsulating the ceramic pucks. Due to the plutonium radiation, remote equipment will perform these operations in a contained environment. The Plutonium Immobilization Project is in the early design stages and the facility will begin operation in 2005. This paper will discuss the Plutonium Immobilization puck handling conceptual design and the puck handling equipment testing.

  13. Metal immobilization and soil amendment efficiency at a contaminated sediment landfill site: a field study focusing on plants, springtails, and bacteria.

    PubMed

    Bert, Valérie; Lors, Christine; Ponge, Jean-François; Caron, Lucie; Biaz, Asmaa; Dazy, Marc; Masfaraud, Jean-François

    2012-10-01

    Metal immobilization may contribute to the environmental management strategy of dredged sediment landfill sites contaminated by metals. In a field experiment, amendment effects and efficiency were investigated, focusing on plants, springtails and bacteria colonisation, metal extractability and sediment ecotoxicity. Conversely to hydroxylapatite (HA, 3% DW), the addition of Thomas Basic Slag (TBS, 5% DW) to a 5-yr deposited sediment contaminated with Zn, Cd, Cu, Pb and As resulted in a decrease in the 0.01 M Ca(NO(3))(2)-extractable concentrations of Cd and Zn. Shoot Cd and Zn concentration in Calamagrostis epigejos, the dominant plant species, also decreased in the presence of TBS. The addition of TBS and HA reduced sediment ecotoxicity and improved the growth of the total bacterial population. Hydroxylapatite improved plant species richness and diversity and decreased antioxidant enzymes in C. Epigejos and Urtica dïoica. Collembolan communities did not differ in abundance and diversity between the different treatments. PMID:22647548

  14. Metallic/bimetallic magnetic nanoparticle functionalization for immobilization of α-amylase for enhanced reusability in bio-catalytic processes.

    PubMed

    Singh, Vishal; Rakshit, Kanak; Rathee, Shweta; Angmo, Stanzin; Kaushal, Shimayali; Garg, Pankaj; Chung, Jong Hoon; Sandhir, Rajat; Sangwan, Rajender S; Singhal, Nitin

    2016-08-01

    Novel magnetic nanoparticles coated with silica and gold were synthesized for immobilization of α-amylase enzyme and characterized with Fourier transform infrared spectroscopy, transmission electron microscopy. Effect of various limiting factors such as substrate concentration, temperature, and pH on the catalytic activity of enzyme was investigated. The optimum pH for free and immobilized enzyme was found unaffected (7.0), whereas optimum temperature for the enzyme activity was increased from 60°C for free enzyme to 80°C for immobilized counterpart. The gains in catalytic attributes concomitant to ease of recovery of the enzyme reflect the potential of the approach and the product to be useful for the enzymatic bioprocessing. The Michaelis-Menten constant (Km) value of the immobilized α-amylase was higher than that of free α-amylase, whereas maximum velocity (Vmax), and turn over number (Kcat), values were almost similar. Immobilized α-amylase maintained 60% of the enzyme activity even after recycling ten times. PMID:27176673

  15. Chromatographic separation of proteins on metal immobilized iminodiacetic acid-bound molded monolithic rods of macroporous poly(glycidyl methacrylate-co-ethylene dimethacrylate).

    PubMed

    Luo, Q; Zou, H; Xiao, X; Guo, Z; Kong, L; Mao, X

    2001-08-17

    Continuous rod of macroporous poly(glycidyl methacrylate-co-ethylene dimethacrylate) was prepared by a free radical polymerization within the confines of a stainless-steel column. The epoxide groups of the rod were modified by a reaction with iminodiacetic acid (IDA) that affords the active site to form metal IDA chelates used for immobilized metal affinity chromatography (IMAC). The efficiency of coupling of IDA to the epoxide-contained matrix was studied as a function of reaction time and temperature. High-performance separation of proteins, based on immobilized different metals on the column, were described. The influence of pH on the adsorption capacity of bovine serum albumin on the Cu2+-IDA continuous rod column was investigated in the range from 5.0 to 9.0. Purification of lysozyme from egg white and human serum albumin (HSA) on the commercially available HSA solution were performed on the naked IDA and Cu2+-IDA continuous rod columns, respectively; and the purity of the obtained fractions was detected by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. PMID:11556331

  16. Facile preparation of an immobilized surfactant-free palladium nanocatalyst for metal hydride trapping: a novel sensing platform for TXRF analysis

    NASA Astrophysics Data System (ADS)

    Romero, V.; Costas-Mora, I.; Lavilla, I.; Bendicho, C.

    2015-01-01

    In this work, a simple route for the synthesis of surfactant-free immobilized palladium nanoparticles (Pd NPs) and their use as effective nanocatalysts for metal hydride decomposition is described. A mixture of ethanol : water was used as the reducing agent. Ethanol was added in a large excess to reduce the ionic Pd and stabilize the obtained Pd NPs. Ethanol is adsorbed on the surface of Pd allowing steric stabilization. Freshly prepared Pd NPs were immobilized onto quartz substrates modified with 3-mercaptopropyltrimethoxysilane. Pd interacts with the thiol group of the alkoxysilane that is adsorbed on the surface of NPs without the dissociation of the S-H bond. Different parameters affecting the synthesis of Pd NPs and their immobilization onto quartz substrates were evaluated. A comprehensive characterization of the synthesized Pd NPs was carried out by transmission electron microscopy (TEM), whereas total reflection X-ray fluorescence (TXRF) spectrometry was applied in order to evaluate their catalytic activity for solid-gas reactions. Immobilized Pd NPs were applied as nanocatalysts for the dissociative chemisorption of arsine at room temperature, yielding the formation of As-Pd bonds. Quartz substrates coated with nanosized Pd could be used as novel sensing platforms for total reflection X-ray fluorescence analysis. Arsenic can be detected in situ in natural water with a limit of detection of 0.08 μg L-1.In this work, a simple route for the synthesis of surfactant-free immobilized palladium nanoparticles (Pd NPs) and their use as effective nanocatalysts for metal hydride decomposition is described. A mixture of ethanol : water was used as the reducing agent. Ethanol was added in a large excess to reduce the ionic Pd and stabilize the obtained Pd NPs. Ethanol is adsorbed on the surface of Pd allowing steric stabilization. Freshly prepared Pd NPs were immobilized onto quartz substrates modified with 3-mercaptopropyltrimethoxysilane. Pd interacts with the thiol

  17. Layer-by-Layer Assembly of Metal-Organic Frameworks in Macroporous Polymer Monolith and Their Use for Enzyme Immobilization.

    PubMed

    Wen, Liyin; Gao, Aicong; Cao, Yao; Svec, Frantisek; Tan, Tianwei; Lv, Yongqin

    2016-03-01

    New monolithic materials comprising zeolitic imidazolate framework (ZIF-8) located on the pore surface of poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith previously functionalized with N-(3-aminopropyl)-imidazole have been prepared via a layer-by-layer self-assembly strategy. These new ZIF-8@monolith hybrids are used as solid-phase carriers for enzyme immobilization. Their performance is demonstrated with immobilization of a model proteolytic enzyme trypsin. The best of the conjugates enable very efficient digestion of proteins that can be achieved in mere 43 s. PMID:26806691

  18. Immobilization of Pb, Cd, and Zn in a contaminated soil using eggshell and banana stem amendments: metal leachability and a sequential extraction study.

    PubMed

    Ashrafi, Mehrnaz; Mohamad, Sharifah; Yusoff, Ismail; Shahul Hamid, Fauziah

    2015-01-01

    Heavy-metal-contaminated soil is one of the major environmental pollution issues all over the world. In this study, two low-cost amendments, inorganic eggshell and organic banana stem, were applied to slightly alkaline soil for the purpose of in situ immobilization of Pb, Cd, and Zn. The artificially metal-contaminated soil was treated with 5% eggshell or 10% banana stem. To simulate the rainfall conditions, a metal leaching experiment for a period of 12 weeks was designed, and the total concentrations of the metals in the leachates were determined every 2 weeks. The results from the metal leaching analysis revealed that eggshell amendment generally reduced the concentrations of Pb, Cd, and Zn in the leachates, whereas banana stem amendment was effective only on the reduction of Cd concentration in the leachates. A sequential extraction analysis was carried out at the end of the experiment to find out the speciation of the heavy metals in the amended soils. Eggshell amendment notably decreased mobility of Pb, Cd, and Zn in the soil by transforming their readily available forms to less accessible fractions. Banana stem amendment also reduced exchangeable form of Cd and increased its residual form in the soil. PMID:25060308

  19. Co-immobilization of multiple enzymes by metal coordinated nucleotide hydrogel nanofibers: improved stability and an enzyme cascade for glucose detection.

    PubMed

    Liang, Hao; Jiang, Shuhui; Yuan, Qipeng; Li, Guofeng; Wang, Feng; Zhang, Zijie; Liu, Juewen

    2016-03-21

    Preserving enzyme activity and promoting synergistic activity via co-localization of multiple enzymes are key topics in bionanotechnology, materials science, and analytical chemistry. This study reports a facile method for co-immobilizing multiple enzymes in metal coordinated hydrogel nanofibers. Specifically, four types of protein enzymes, including glucose oxidase, Candida rugosa lipase, α-amylase, and horseradish peroxidase, were respectively encapsulated in a gel nanofiber made of Zn(2+) and adenosine monophosphate (AMP) with a simple mixing step. Most enzymes achieved quantitative loading and retained full activity. At the same time, the entrapped enzymes were more stable against temperature variation (by 7.5 °C), protease attack, extreme pH (by 2-fold), and organic solvents. After storing for 15 days, the entrapped enzyme still retained 70% activity while the free enzyme nearly completely lost its activity. Compared to nanoparticles formed with AMP and lanthanide ions, the nanofiber gels allowed much higher enzyme activity. Finally, a highly sensitive and selective biosensor for glucose was prepared using the gel nanofiber to co-immobilize glucose oxidase and horseradish peroxidase for an enzyme cascade system. A detection limit of 0.3 μM glucose with excellent selectivity was achieved. This work indicates that metal coordinated materials using nucleotides are highly useful for interfacing with biomolecules. PMID:26932320

  20. Efficient fabrication of high-capacity immobilized metal ion affinity chromatographic media: The role of the dextran-grafting process and its manipulation.

    PubMed

    Zhao, Lan; Zhang, Jingfei; Huang, Yongdong; Li, Qiang; Zhang, Rongyue; Zhu, Kai; Suo, Jia; Su, Zhiguo; Zhang, Zhigang; Ma, Guanghui

    2016-03-01

    Novel high-capacity Ni(2+) immobilized metal ion affinity chromatographic media were prepared through the dextran-grafting process. Dextran was grafted to an allyl-activated agarose-based matrix followed by functionalization for the immobilized metal ion affinity chromatographic media. With elaborate regulation of the allylation degree, dextran was completely or partly grafted to agarose microspheres, namely, completely dextran-grafted agarose microspheres and partly dextran-grafted ones, respectively. Confocal laser scanning microscope results demonstrated that a good adjustment of dextran-grafting degree was achieved, and dextran was distributed uniformly in whole completely dextran-grafted microspheres, while just distributed around the outside of the partly dextran-grafted ones. Flow hydrodynamic properties were improved greatly after the dextran-grafting process, and the flow velocity increased by about 30% compared with that of a commercial chromatographic medium (Ni Sepharose FF). A significant improvement of protein binding performance was also achieved by the dextran-grafting process, and partly dextran-grafted Ni(2+) chelating medium had a maximum binding capacity for His-tagged lactate dehydrogenase about 2.5 times higher than that of Ni Sepharose FF. The results indicated that this novel chromatographic medium is promising for applications in high-efficiency and large-scale protein purification. PMID:26786724

  1. Engineering foot-and-mouth disease virus serotype O IND R2/1975 for one-step purification by immobilized metal affinity chromatography.

    PubMed

    Biswal, Jitendra K; Bisht, Punam; Subramaniam, Saravanan; Ranjan, Rajeev; Sharma, Gaurav K; Pattnaik, Bramhadev

    2015-09-01

    Immobilized metal affinity chromatography (IMAC) allows for the efficient protein purification via metal affinity tag such as hexa-histidine (His6) sequence. To develop a new chromatography strategy for the purification and concentration of foot-and-mouth disease virus (FMDV) particles, we inserted the His6-tag at the earlier reported site in the VP1 G-H loop of the FMD virus serotype O vaccine strain IND R2/1975. Display of the His6-tag on the capsid surface, endowed the virus with an increased affinity for immobilized nickel ions. We demonstrated that the His6-tagged FMDV could be produced to high titre and purified from the infected BHK-21 cell lysates by IMAC efficiently. Further, a 1150-fold reduction in protein contaminant level and an 8400-fold reduction in DNA contaminant level were achieved in the IMAC purification of His6-tagged FMDV. Through various functional assays it has been found that the tagged virus retains its functionality and infectivity similar to the non-tagged virus. The affinity purification of the His6-tagged FMDV may offer a feasible, alternative approach to the current methods of FMDV antigen purification, concentration and process scalability. PMID:26123433

  2. Study of immobilized metal affinity chromatography sorbents for the analysis of peptides by on-line solid-phase extraction capillary electrophoresis-mass spectrometry.

    PubMed

    Ortiz-Martin, Lorena; Benavente, Fernando; Medina-Casanellas, Silvia; Giménez, Estela; Sanz-Nebot, Victoria

    2015-03-01

    Several commercial immobilized metal affinity chromatography sorbents were evaluated in this study for the analysis of two small peptide fragments of the amyloid β-protein (Aβ) (Aβ(1-15) and Aβ(10-20) peptides) by on-line immobilized metal affinity SPE-CE (IMA-SPE-CE). The performance of a nickel metal ion (Ni(II)) sorbent based on nitrilotriacetic acid as a chelating agent was significantly better than two copper metal ion (Cu(II)) sorbents based on iminodiacetic acid. A BGE of 25 mM phosphate (pH 7.4) and an eluent of 50 mM imidazole (in BGE) yielded a 25-fold and 5-fold decrease in the LODs by IMA-SPE-CE-UV for Aβ(1-15) and Aβ(10-20) peptides (0.1 and 0.5 μg/mL, respectively) with regard to CE-UV (2.5 μg/mL for both peptides). The phosphate BGE was also used in IMA-SPE-CE-MS, but the eluent needed to be substituted by a 0.5% HAc v/v solution. Under optimum preconcentration and detection conditions, reproducibility of peak areas and migration times was acceptable (23.2 and 12.0%RSD, respectively). The method was more sensitive for Aβ(10-20) peptide, which could be detected until 0.25 μg/mL. Linearity for Aβ(10-20) peptide was good in a narrow concentration range (0.25-2.5 μg/mL, R(2) = 0.93). Lastly, the potential of the optimized Ni(II)-IMA-SPE-CE-MS method for the analysis of amyloid peptides in biological fluids was evaluated by analyzing spiked plasma and serum samples. PMID:25640944

  3. Immobilized tubular fermentor

    SciTech Connect

    Gencer, M.A.; Mutharasan, R.

    1983-09-01

    In this article, a mathematical model describing the kinetics of ethanol fermentation in a whole cell immobilized tubular fermentor is proposed. Experimental results show reasonable agreement with the proposed model. A procedure for treating the fermentation data for determining the ethanol inhibition constants k1 and k2 is described. The ethanol productivity of the immobilized cell fermentor is compared with those of traditional fermentors. Experimental studies indicate that with Saccharomyces cerevisiae (NRRL Y132) culture, ethanol productivity in the range 21.2-83.7 g ethanol/L/h at ethanol concentration of 76-60 g/L can be achieved. This is comparable to or higher than those reported in the literature for yeast. The product yield factor of 0.5 g ethanol/g glucose was obtained. The immobilized cell fermentor does not show washout at dilution rates of 7/h and shows good stability over a 650-h operating period.

  4. Synthesis of a water-soluble thiourea-formaldehyde (WTF) resin and its application to immobilize the heavy metal in MSWI fly ash.

    PubMed

    Liu, She-Jiang; Guo, Yu-Peng; Yang, Hong-Yang; Wang, Shen; Ding, Hui; Qi, Yun

    2016-11-01

    Because of the high concentrations of heavy metals, municipal solid waste incineration (MSWI) fly ash is classified as a hazardous waste, which need to be treated to avoid damaging the environment. A novel water-soluble thiourea-formaldehyde (WTF) resin was synthesized by two step reactions (hydroxymethylation reaction and condensation reaction) in the laboratory. Synthetic conditions, removal of free formaldehyde in the resin and the ability of immobilization heavy metals in the MSWI fly ash were studied. The possible molecular structure of the resin was also discussed by elemental analysis and FTIR spectra. Experimental results showed that the synthesis conditions of WTF resin were the formaldehyde/thiourea (T/F) mole ratio of 2.5:1, hydroxymethylation at pH 7.0-8.0 and 60 °C for 30min, and condensation of at pH 4.5-5.0 and 80 °C. In addition, the end point of condensation reaction was measured by turbidity point method. The result of elemental analysis and FTIR spectra indicated that thiourea functional group in the WTF resin chelated the heavy metal ions. Melamine can efficiently reduce the free formaldehyde content in the resin from 8.5% to 2%. The leaching test showed that the immobilization rates of Cr, Pb and Cd were 96.5%, 92.0% and 85.8%, respectively. Leaching concentrations of Cr, Pb and Cd in the treated fly ash were decreased to 0.08 mg/L, 2.44 mg/L and 0.23 mg/L, respectively. The MSWI fly ash treated by WTF resin has no harm to the environment. PMID:27497309

  5. Microorganism immobilization

    DOEpatents

    Compere, Alicia L.; Griffith, William L.

    1981-01-01

    Live metabolically active microorganisms are immobilized on a solid support by contacting particles of aggregate material with a water dispersible polyelectrolyte such as gelatin, crosslinking the polyelectrolyte by reacting it with a crosslinking agent such as glutaraldehyde to provide a crosslinked coating on the particles of aggregate material, contacting the coated particles with live microorganisms and incubating the microorganisms in contact with the crosslinked coating to provide a coating of metabolically active microorganisms. The immobilized microorganisms have continued growth and reproduction functions.

  6. A glass-encapsulated calcium phosphate wasteform for the immobilization of actinide-, fluoride-, and chloride-containing radioactive wastes from the pyrochemical reprocessing of plutonium metal

    NASA Astrophysics Data System (ADS)

    Donald, I. W.; Metcalfe, B. L.; Fong, S. K.; Gerrard, L. A.; Strachan, D. M.; Scheele, R. D.

    2007-03-01

    Chloride-containing radioactive wastes are generated during the pyrochemical reprocessing of Pu metal. Immobilization of these wastes in borosilicate glass or Synroc-type ceramics is not feasible due to the very low solubility of chlorides in these hosts. Alternative candidates have therefore been sought including phosphate-based glasses, crystalline ceramics and hybrid glass/ceramic systems. These studies have shown that high losses of chloride or evolution of chlorine gas from the melt make vitrification an unacceptable solution unless suitable off-gas treatment facilities capable of dealing with these corrosive by-products are available. On the other hand, both sodium aluminosilicate and calcium phosphate ceramics are capable of retaining chloride in stable mineral phases, which include sodalite, Na 8(AlSiO 4) 6Cl 2, chlorapatite, Ca 5(PO 4) 3Cl, and spodiosite, Ca 2(PO 4)Cl. The immobilization process developed in this study involves a solid state process in which waste and precursor powders are mixed and reacted in air at temperatures in the range 700-800 °C. The ceramic products are non-hygroscopic free-flowing powders that only require encapsulation in a relatively low melting temperature phosphate-based glass to produce a monolithic wasteform suitable for storage and ultimate disposal.

  7. Living organisms as an alternative to hyphenated techniques for metal speciation. Evaluation of baker's yeast immobilized on silica gel for Hg speciation*1

    NASA Astrophysics Data System (ADS)

    Pérez-Corona, Teresa; Madrid-Albarrán, Yolanda; Cámara, Carmen; Beceiro, Elisa

    1998-02-01

    The use of living organisms for metal preconcentration and speciation is discussed. Among substrates, Saccharomyces cerevisiae baker's yeast has been successfully used for the speciation of mercury [Hg(II) and CH 3Hg +], selenium [Se(IV) and Se(VI)] and antimony [Sb(III) and Sb(V)]. To illustrate the capabilities of these organisms, the analytical performance of baker's yeast immobilized on silica gel for on-line preconcentration and speciation of Hg(II) and methylmercury is reported. The immobilized cells were packed in a PTFE microcolumn, through which mixtures of organic and inorganic mercury solutions were passed. Retention of inorganic and organic mercury solutions took place simultaneously, with the former retained in the silica and the latter on the yeast. The efficiency uptake for both species was higher than 95% over a wide pH range. The speciation was carried out by selective and sequential elution with 0.02 mol L -1 HCl for methylmercury and 0.8 mol L -1 CN - for Hg(II). This method allows both preconcentration and speciation of mercury. The preconcentration factors were around 15 and 100 for methylmercury and mercury(II), respectively. The method has been successfully applied to spiked sea water samples.

  8. Immobilization of Metal-Organic Framework Copper(II) Benzene-1,3,5-tricarboxylate (CuBTC) onto Cotton Fabric as a Nitric Oxide Release Catalyst.

    PubMed

    Neufeld, Megan J; Harding, Jacqueline L; Reynolds, Melissa M

    2015-12-01

    Immobilization of metal-organic frameworks (MOFs) onto flexible polymeric substrates as secondary supports expands the versatility of MOFs for surface coatings for the development of functional materials. In this work, we demonstrate the deposition of copper(II) benzene-1,3,5-tricarboxylate (CuBTC) crystals directly onto the surface of carboxyl-functionalized cotton capable of generating the therapeutic bioagent nitric oxide (NO) from endogenous sources. Characterization of the CuBTC-cotton material by XRD, ATR-IR, and UV-vis indicate that CuBTC is successfully immobilized on the cotton fabric. In addition, SEM imaging reveals excellent surface coverage with well-defined CuBTC crystals. Subsequently, the CuBTC-cotton material was evaluated as a supported heterogeneous catalyst for the generation of NO using S-nitrosocysteamine as the substrate. The resulting reactivity is consistent with the activity observed for unsupported CuBTC particles. Overall, this work demonstrates deposition of MOFs onto a flexible polymeric material with excellent coverage as well as catalytic NO release from S-nitrosocysteamine at therapeutic levels. PMID:26595600

  9. Co-immobilization of multiple enzymes by metal coordinated nucleotide hydrogel nanofibers: improved stability and an enzyme cascade for glucose detection

    NASA Astrophysics Data System (ADS)

    Liang, Hao; Jiang, Shuhui; Yuan, Qipeng; Li, Guofeng; Wang, Feng; Zhang, Zijie; Liu, Juewen

    2016-03-01

    Preserving enzyme activity and promoting synergistic activity via co-localization of multiple enzymes are key topics in bionanotechnology, materials science, and analytical chemistry. This study reports a facile method for co-immobilizing multiple enzymes in metal coordinated hydrogel nanofibers. Specifically, four types of protein enzymes, including glucose oxidase, Candida rugosa lipase, α-amylase, and horseradish peroxidase, were respectively encapsulated in a gel nanofiber made of Zn2+ and adenosine monophosphate (AMP) with a simple mixing step. Most enzymes achieved quantitative loading and retained full activity. At the same time, the entrapped enzymes were more stable against temperature variation (by 7.5 °C), protease attack, extreme pH (by 2-fold), and organic solvents. After storing for 15 days, the entrapped enzyme still retained 70% activity while the free enzyme nearly completely lost its activity. Compared to nanoparticles formed with AMP and lanthanide ions, the nanofiber gels allowed much higher enzyme activity. Finally, a highly sensitive and selective biosensor for glucose was prepared using the gel nanofiber to co-immobilize glucose oxidase and horseradish peroxidase for an enzyme cascade system. A detection limit of 0.3 μM glucose with excellent selectivity was achieved. This work indicates that metal coordinated materials using nucleotides are highly useful for interfacing with biomolecules.Preserving enzyme activity and promoting synergistic activity via co-localization of multiple enzymes are key topics in bionanotechnology, materials science, and analytical chemistry. This study reports a facile method for co-immobilizing multiple enzymes in metal coordinated hydrogel nanofibers. Specifically, four types of protein enzymes, including glucose oxidase, Candida rugosa lipase, α-amylase, and horseradish peroxidase, were respectively encapsulated in a gel nanofiber made of Zn2+ and adenosine monophosphate (AMP) with a simple mixing step. Most

  10. Literature review of metal corrosion sensitivity in high temperature, high impurity hot cell atmospheres

    SciTech Connect

    Eberle, C.S.

    1997-09-01

    The pyrochemical conditions of spent nuclear fuel for the purpose of final disposal is being demonstrated at Argonne National Laboratory (ANL). One aspect of this program is to develop a lithium preprocessing stage for the Fuel Conditioning Facility (FCF). One of the design considerations under investigation in this program is the system`s corrosion response in the presence of irradiated commercial fuel as well as atmospheric impurities. Static corrosion coupon tests have been completed which demonstrate the potential corrosivity of the salt matrix in a worse case environment as well as provide a boundary for allowable impurities in the system during operation. The literature concerning corrosion of either fused salts or molten metals consistently emphasizes three similar features which are common to both systems: (1) the overall corrosion rate is strongly dependent on temperature, impurity concentration and flow velocity; (2) many different mechanisms can be involved in a specific corrosion process; and (3) corrosion rates will significantly increase as all three of these independent variables are increased. The qualitative and quantitative understanding of these corrosion results is important for this spent fuel program since all of these variables will increase as the process scale increases. The purpose of this work was to determine if any data existed which could provide a quantitative expectation for corrosion rates of refractory metals in a lithium chloride salt bath.

  11. SEQUESTERING AGENTS FOR METAL IMMOBILIZATION APPLICATION TO THE DEVELOPMENT OF ACTIVE CAPS IN FRESH AND SALT WATER SEDIMENTS

    SciTech Connect

    Knox, A; Michael Paller, M

    2006-11-17

    This research evaluated the removal of inorganic contaminants by a variety of amendments and mixtures of amendments in fresh and salt water. A series of removal and retention batch experiments was conducted to identify the best treatment for metal removal. Metal removal by the amendments was evaluated by calculating the partition coefficient and percent removal. Retention of metals by the amendments was evaluated in retention (desorption) studies in which residue from the removal studies was extracted with 1 M MgCl{sub 2} solution. The results indicated that phosphate amendments, some organoclays (e.g., OCB-750), and the biopolymer, chitosan, are very effective in removal and retention of metals in both fresh and salt water. These amendments are being evaluated further as components in the development of active caps for sediment remediation.

  12. Bibliography of the technical literature of the Materials Joining Group, Metals and Ceramics Division, 1951--June 1989

    SciTech Connect

    David, S.A.; Goodwin, G.M.; Gardner, K.

    1989-10-01

    This document contains a listing of the written scientific information originating in the Materials Joining (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1989. This registry of documents is as much as possible, in the order of issue date. A complete cross-referenced listing of the technical literature of the Metals and Ceramics Division is also available.

  13. Engineering Escherichia coli BL21(DE3) Derivative Strains To Minimize E. coli Protein Contamination after Purification by Immobilized Metal Affinity Chromatography ▿ † ‡

    PubMed Central

    Robichon, Carine; Luo, Jianying; Causey, Thomas B.; Benner, Jack S.; Samuelson, James C.

    2011-01-01

    Recombinant His-tagged proteins expressed in Escherichia coli and purified by immobilized metal affinity chromatography (IMAC) are commonly coeluted with native E. coli proteins, especially if the recombinant protein is expressed at a low level. The E. coli contaminants display high affinity to divalent nickel or cobalt ions, mainly due to the presence of clustered histidine residues or biologically relevant metal binding sites. To improve the final purity of expressed His-tagged protein, we engineered E. coli BL21(DE3) expression strains in which the most recurring contaminants are either expressed with an alternative tag or mutated to decrease their affinity to divalent cations. The current study presents the design, engineering, and characterization of two E. coli BL21(DE3) derivatives, NiCo21(DE3) and NiCo22(DE3), which express the endogenous proteins SlyD, Can, ArnA, and (optionally) AceE fused at their C terminus to a chitin binding domain (CBD) and the protein GlmS, with six surface histidines replaced by alanines. We show that each E. coli CBD-tagged protein remains active and can be efficiently eliminated from an IMAC elution fraction using a chitin column flowthrough step, while the modification of GlmS results in loss of affinity for nickel-containing resin. The “NiCo” strains uniquely complement existing methods for improving the purity of recombinant His-tagged protein. PMID:21602383

  14. An inorganic-organic hybrid optical sensor for heavy metal ion detection based on immobilizing 4-(2-pyridylazo)-resorcinol on functionalized HMS.

    PubMed

    Liu, Tongge; Li, Gang; Zhang, Na; Chen, Yongying

    2012-01-30

    A novel and low-cost optical sensor for heavy metal ion detection has been prepared by immobilizing 4-(2-pyridylazo)-resorcinol (PAR) on the functionalized hexagonal mesoporous silica (HMS) via N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride (TMAC). The successful fabrication of this optical sensor is confirmed by extensive characterizations using FT-IR, low angle X-ray diffraction (XRD), UV-vis spectroscopy and N(2) sorption, meanwhile its colorimetric properties, selectivity, sensitivity and reversibility are also investigated. The optical sensor responds selectively to heavy metal ions, such as Fe(3+), Cd(2+), Ni(2+), Zn(2+), Pb(2+), Co(2+), Hg(2+) and Cu(2+) with a color change from yellow to orange or purple in alkaline solutions, while it shows a color change only for Cu(2+) under strongly acidic conditions. At pH 12.0, this optical sensor has a high sensitivity that makes it possible to detect Cu(2+) in aqueous solution with the detection limit as low as 40ppb by naked-eye. This optical sensor also shows excellent reversibility and regeneration by treatment with a solution of EDTA. PMID:22177015

  15. The effects of alkaline dosage and Si/Al ratio on the immobilization of heavy metals in municipal solid waste incineration fly ash-based geopolymer.

    PubMed

    Zheng, Lei; Wang, Wei; Shi, Yunchun

    2010-04-01

    The present research explored the application of geopolymerization for the immobilization and solidification of municipal solid waste incineration (MSWI) fly ash. The influence of alkaline activator dosage and Si/Al molar ratio on the compressive strength and microstructure of MSWI fly ash-based geopolymer was investigated. A geopolymer with the highest strength was identified to occur at an intermediate alkaline activator dosage and Si/Al ratio, and the optimal Na/MSWI fly ash and Si/Al molar ratio was close to 2.8 mol kg(-1) and 2.0, respectively. IR spectra showed that higher alkaline activator dosage enhanced the structural disruption of the original aluminosilicate phases and a higher degree of polymerization of the geopolymer networks. At low Si/Al ratio, there was an increasing number of tetrahedral Al incorporating into the silicate backbone. As the Na/MSWI fly ash ratio increased, the microstructure changed from containing large macropores to more mesopores and micropores, indicating that more geopolymers are formed. Furthermore, the pore volume distribution of geopolymers was observed to shift to larger pores as the Si/Al ratio increased, which suggests that the soluble silicon content serves to reduce the amount of geopolymers. Heavy metal leaching was successfully elucidated using the first-order reaction/reaction-diffusion model. Combining the results from the microstructure of samples with the kinetic analysis, the immobilization mechanism of Cr, Cu, and Zn was inferred in this study. The methodologies described could provide a powerful set of tools for the systematic evaluation of element release from geopolymers. PMID:20304461

  16. Exploiting multi-function Metal-Organic Framework nanocomposite Ag@Zn-TSA as highly efficient immobilization matrixes for sensitive electrochemical biosensing.

    PubMed

    Dong, Sheying; Zhang, Dandan; Suo, Gaochao; Wei, Wenbo; Huang, Tinglin

    2016-08-31

    A novel multi-function Metal-Organic Framework composite Ag@Zn-TSA (zinc thiosalicylate, Zn(C7H4O2S), Zn-TSA) was synthesized as highly efficient immobilization matrixes of myoglobin (Mb)/glucose oxidase (GOx) for electrochemical biosensing. The electrochemical biosensors based on Ag@Zn-TSA composite and ionic liquid (IL) modified carbon paste electrode (CPE) were fabricated successfully. Furthermore, the properties of the sensors were discussed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and amperometric current-time curve, respectively. The results showed the proposed biosensors had wide linear response to hydrogen peroxide (H2O2) in the range of 0.3-20,000 μM, to nitrite (NO2(-)) for 1.3 μM-1660 μM and 2262 μM-1,33,000 μM, to glucose for 2.0-1022 μM, with a low detection limit of 0.08 μM for H2O2, 0.5 μM for NO2(-), 0.8 μM for glucose. The values of the apparent heterogeneous electron transfer rate constant (ks) for Mb and GOx were estimated as 2.05 s(-1) and 2.45 s(-1), respectively. Thus, Ag@Zn-TSA was a kind of ideal material as highly efficient immobilization matrixes for sensitive electrochemical biosensing. In addition, this work indicated that MOF nanocomposite had a great potential for constructing wide range of sensing interface. PMID:27506361

  17. Immobilization of a Metal-Nitrogen-Carbon Catalyst on Activated Carbon with Enhanced Cathode Performance in Microbial Fuel Cells.

    PubMed

    Yang, Wulin; Logan, Bruce E

    2016-08-23

    Applications of microbial fuel cells (MFCs) are limited in part by low power densities mainly due to cathode performance. Successful immobilization of an Fe-N-C co-catalyst on activated carbon (Fe-N-C/AC) improved the oxygen reduction reaction to nearly a four-electron transfer, compared to a twoelectron transfer achieved using AC. With acetate as the fuel, the maximum power density was 4.7±0.2 W m(-2) , which is higher than any previous report for an air-cathode MFC. With domestic wastewater as a fuel, MFCs with the Fe-N-C/AC cathode produced up to 0.8±0.03 W m(-2) , which was twice that obtained with a Pt-catalyzed cathode. The use of this Fe-N-C/AC catalyst can therefore substantially increase power production, and enable broader applications of MFCs for renewable electricity generation using waste materials. PMID:27416965

  18. Self-expandable metal stents for malignant gastric outlet obstruction: A pooled analysis of prospective literature

    PubMed Central

    van Halsema, Emo E; Rauws, Erik AJ; Fockens, Paul; van Hooft, Jeanin E

    2015-01-01

    AIM: To provide an overview of the clinical outcomes of self-expandable metal stent (SEMS) placement for malignant gastric outlet obstruction (MGOO). METHODS: A systematic literature search was performed in PubMed of the literature published between January 2009 and March 2015. Only prospective studies that reported on the clinical success of stent placement for MGOO were included. The primary endpoint was clinical success, defined according to the definition used in the original article. Data were pooled and analyzed using descriptive statistics. Subgroup analyses were performed for partially covered SEMSs (PCSEMSs) and uncovered SEMSs (UCSEMSs) using Fisher’s exact test. RESULTS: A total of 19 studies, including 1281 patients, were included in the final analysis. Gastric (42%) and pancreatic (37%) cancer were the main causes of MGOO. UCSEMSs were used in 76% of patients and PCSEMSs in 24%. The overall pooled technical success rate was 97.3% and the clinical success rate was 85.7%. Stent dysfunction occurred in 19.6% of patients, mainly caused by re-obstruction (12.6%) and stent migration (4.3%), and was comparable between PCSEMSs and UCSEMSs (21.2% vs 19.1%, respectively, P = 0.412). Re-obstruction was more common with UCSEMSs (14.9% vs 5.1%, P < 0.001) and stent migration was more frequent after PCSEMS placement (10.9% vs 2.2%, P < 0.001). The overall perforation rate was 1.2%. Bleeding was reported in 4.1% of patients, including major bleeding in 0.8%. The median stent patency ranged from 68 to 307 d in five studies. The median overall survival ranged from 49 to 183 d in 13 studies. CONCLUSION: The clinical outcomes in this large population showed that enteral stent placement was feasible, effective and safe. Therefore, stent placement is a valid treatment option for the palliation of MGOO. PMID:26604654

  19. Metal-Organic Frameworks: Literature Survey and Recommendation of Potential Sorbent Materials

    SciTech Connect

    Baumann, T F

    2010-04-29

    Metal-organic frameworks (MOFs) are a special type of porous material with a number of unique properties, including exceptionally high surface areas, large internal pore volumes (void space) and tunable pore sizes. These materials are prepared through the assembly of molecular building blocks into ordered three-dimensional structures. The bulk properties of the MOF are determined by the nature of the building blocks and, as such, these materials can be designed with special characteristics that cannot be realized in other sorbent materials, like activated carbons. For example, MOFs can be constructed with binding sites or pockets that can exhibit selectivity for specific analytes. Alternatively, the framework can be engineered to undergo reversible dimensional changes (or 'breathing') upon interaction with an analyte, effectively trapping the molecule of interest in the lattice structure. In this report, we have surveyed the 4000 different MOF structures reported in the open literature and provided recommendations for specific MOF materials that should be investigated as sorbents for this project.

  20. Zeolite-type metal organic frameworks immobilized Eu³⁺ for cation sensing in aqueous environment.

    PubMed

    Liu, Chang; Yan, Bing

    2015-12-01

    A novel luminescent lanthanide metal organic framework (Ln-MOF) is synthesized by in situ encapsulating Eu(3+) ions to partial replace the transition-metal clusters in the channels of CPM-17-Zn nanocrystals. The Eu(3+) functionalized zeolite-type MOF hybrid system shows excellent luminescence property and photo-stability in aqueous environment for the sensitization and protection from the host framework. Subsequently, as a highly selective and sensitive sensor, its nanocrystals can be used to detect Cd(2+) in aqueous solution. In addition, the possible sensing mechanism based on ion exchange is discussed in detail. This work is one of the few cases for detecting Cd(2+) in aqueous solution based on a zeolite-type MOF. The good fluorescence stability, low detection limit and broad linear range in aqueous environment make this probe to be expected to have potential application in intracellular sensing and imaging of Cd(2+) potentially. PMID:26298079

  1. The catalytic performance of metal complexes immobilized on SBA-15 in the ring opening polymerization of ε-caprolactone with different metals (Ti, Al, Zn and Mg) and immobilization procedures.

    PubMed

    Pérez, Yolanda; del Hierro, Isabel; Zazo, Lydia; Fernández-Galán, Rafael; Fajardo, Mariano

    2015-03-01

    A family of heterogeneous catalysts has been prepared by employing different strategies: firstly by direct reaction or grafting of titanium, zinc, aluminium and magnesium precursors with dehydrated SBA-15 and secondly by reaction of the metallic derivatives with a hybrid SBA-15 mesoporous material, which possesses a new covalently bonded linker based on an amino alcohol chelate ligand. These materials have been characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), N2 adsorption-desorption, FT-IR and multi-nuclear NMR spectroscopy. The catalytic performance of the prepared materials has been studied in the ring opening polymerization of ε-caprolactone and compared with that of their homogeneous counterparts. Conversion values obtained by using homogeneous and heterogeneous catalysts depend on the metal precursor and the synthetic procedure. The most active heterogeneous Ti-SBA-15, Zn-SBA-15 and Zn-PADO-HMDS-SBA-15 catalysts produced poly(ε-caprolactone) with a narrow molecular weight distribution, close to one. In all cases polymerization was confirmed to proceed via a coordination insertion mechanism after end group analysis by (1)H NMR. PMID:25623360

  2. Evaluation of metal mobility, plant availability and immobilization by chemical agents in a limed-silty soil.

    PubMed

    Mench, M; Vangronsveld, J; Didier, V; Clijsters, H

    1994-01-01

    Metal-contaminated soils in the vicinity of industrial sites become of ever-increasing concern. Diagnostic criteria and ecological technologies for soil remediation should be calibrated for various soil conditions; actually, our knowledge of calcareous soil is poor. Silty soils near smelters at Evin (Pas de Calais, France) have been contaminated by non-ferrous metal fallout and regularly limed using foams. Therefore, the mobility, bioavailability, and potential phytotoxicity of Cd, Pb and Zn, were investigated using single soil extractions (i.e. water, 0.1 n Ca(NO(3))(2), and EDTA pH 7), and vegetation experiments, in parallel with a biological test based on (iso)-enzymes in leaves and roots, before and following soil treatment with chemical agents, i.e. Thomas basic slags (TBS), hydrous manganese oxide (HMO), steel shots (ST) and beringite. No visible toxicity symptoms developed on the above-ground parts of ryegrass, tobacco and bean plants grown in potted soil under controlled environmental conditions. Cd, Zn and Pb uptake resulted in high concentrations in the above-ground plant parts, but the enzyme capacities in leaves and roots, and the peroxidase pattern indicated that these metal concentrations were not phytotoxic for beans as test plants. The addition of chemical agents to the soil did not increase biomass production, but treatment with either HMO, ST or beringite markedly decreased the mobility of Cd, Zn and Pb. These agents were proven to be effective in mitigating the Cd uptake by plants. HMO and ST decreased either Pb or Zn uptake by ryegrass. TBS was effective in lowering Pb uptake by the same species. Beringite decreased Cd uptake by beans. If fallout could be restricted, the metal content of food crops in this area should be lowered by soil treatment. However, the differences in Cd uptake between plant species were not suppressed, regardless of the type of agents applied to the soil. PMID:15091619

  3. Covalent immobilization of metal-organic frameworks onto the surface of nylon--a new approach to the functionalization and coloration of textiles.

    PubMed

    Yu, Ming; Li, Wanxin; Wang, Ziqiang; Zhang, Bowu; Ma, Hongjuan; Li, Linfan; Li, Jingye

    2016-01-01

    The prevention of refractory organic pollution caused by conventional dyeing and the development of new fabrics with various functions are two issues to be solved urgently in the field of textile fabrication. Here, we report a new environmentally friendly route for the simultaneous coloration and functionalization of textiles by the covalent immobilization of a metal-organic framework, Cr-based MIL-101(Cr), onto the surfaces of nylon fabrics by co-graft polymerization with 2-hydroxyethyl acrylate initiated by γ-ray irradiation. The Cr(III) clusters color the nylon fabric, and the color intensity varies with the MIL-101 content, providing a "green" textile coloration method that is different from conventional dyeing processes. An X-ray diffraction (XRD) analysis shows that the nanoporous structure of the original MIL-101 particles is retained during radiation-induced graft polymerization. Numerous nanopores are introduced onto the surface of the nylon fabric, which demonstrated better sustained-release-of-aroma performance versus pristine nylon fabric in tests. The modified fabrics exhibit laundering durability, with MIL-101 nanoparticles intact on the nylon surface after 30 h of dry cleaning. PMID:26948405

  4. Characterization of biases in phosphopeptide enrichment by Ti(4+)-immobilized metal affinity chromatography and TiO2 using a massive synthetic library and human cell digests.

    PubMed

    Matheron, Lucrece; van den Toorn, Henk; Heck, Albert J R; Mohammed, Shabaz

    2014-08-19

    Outcomes of comparative evaluations of enrichment methods for phosphopeptides depend highly on the experimental protocols used, the operator, the source of the affinity matrix, and the samples analyzed. Here, we attempt such a comparative study exploring a very large synthetic library containing thousands of serine, threonine, and tyrosine phosphorylated peptides, being present in roughly equal abundance, along with their nonphosphorylated counterparts, and use an optimized protocol for enrichment by TiO2 and Ti(4+)-immobilized metal affinity chromatography (IMAC) by a single operator. Surprisingly, our data reveal that there are minimal differences between enrichment of phosphopeptides by TiO2 and Ti(4+)-IMAC when considering biochemical and biophysical parameters such as peptide length, sequence surrounding the site, hydrophobicity, and nature of the amino acid phosphorylated. Similar results were obtained when evaluating a tryptic digest of a cellular lysate, representing a more natural source of phosphopeptides. All the data presented are available via ProteomeXchange with the identifier PXD000759. PMID:25068997

  5. Immobilized metal affinity chromatography on collapsed Langmuir-Blodgett iron(III) stearate films and iron(III) oxide nanoparticles for bottom-up phosphoproteomics.

    PubMed

    Gladilovich, Vladimir; Greifenhagen, Uta; Sukhodolov, Nikolai; Selyutin, Artem; Singer, David; Thieme, Domenika; Majovsky, Petra; Shirkin, Alexey; Hoehenwarter, Wolfgang; Bonitenko, Evgeny; Podolskaya, Ekaterina; Frolov, Andrej

    2016-04-22

    Phosphorylation is the enzymatic reaction of site-specific phosphate transfer from energy-rich donors to the side chains of serine, threonine, tyrosine, and histidine residues in proteins. In living cells, reversible phosphorylation underlies a universal mechanism of intracellular signal transduction. In this context, analysis of the phosphoproteome is a prerequisite to better understand the cellular regulatory networks. Conventionally, due to the low contents of signaling proteins, selective enrichment of proteolytic phosphopeptides by immobilized metal affinity chromatography (IMAC) is performed prior to their LC-MS or -MS/MS analysis. Unfortunately, this technique still suffers from low selectivity and compromised analyte recoveries. To overcome these limitations, we propose IMAC systems comprising stationary phases based on collapsed Langmuir-Blodgett films of iron(III) stearate (FF) or iron(III) oxide nanoparticles (FO) and mobile phases relying on ammonia, piperidine and heptadecafluorooctanesulfonic acid (PFOS). Experiments with model phosphopeptides and phosphoprotein tryptic digests showed superior binding capacity, selectivity and recovery for both systems in comparison to the existing commercial analogs. As evidenced by LC-MS/MS analysis of the HeLa phosphoproteome, these features of the phases resulted in increased phosphoproteome coverage in comparison to the analogous commercially available phases, indicating that our IMAC protocol is a promising chromatographic tool for in-depth phosphoproteomic research. PMID:27016113

  6. Purification of α2-macroglobulin from Cohn Fraction IV by immobilized metal affinity chromatography: A promising method for the better utilization of plasma.

    PubMed

    Huangfu, Chaoji; Ma, Yuyuan; Lv, Maomin; Jia, Junting; Zhao, Xiong; Zhang, Jingang

    2016-07-01

    As an abundant plasma protein, α2-macroglobulin (α2-M) participates widely in physiological and pathological activities including coagulation regulation, antitumor activities, and regulation of cytokines. It also presents a therapeutic potential for radiation injury. A two-step isolation method for the purification of α2-M from Cohn Fraction IV is described. This process includes a salting-out method and immobilized metal affinity chromatography. The LC-ESI-MS/MS analysis and a comparison of the amino acid composition demonstrated that the final product was α2-M. The final protein, with a purity of approximately 95% and a yield of nearly 45%, was obtained from Cohn Fraction IV regardless of plasma haptoglobin type, although all but type 1-1 have previously been considered unfavorable for α2-M preparation. The effects of temperature, pH, and methylamine on α2-M activity were evaluated to avoid activity loss during preparation and preservation. The results suggested that α2-M activity could be readily inactivated at temperatures above 50°C, at pH levels above 9.0 or below 4.0, or in the presence of methylamine. Cohn Fraction IV is usually discarded as a biological waste product in the human serum albumin production process; because the simple process developed in this study is relatively inexpensive, the preparation of α2-M from Cohn Fraction IV may better utilize human plasma, a valuable resource. PMID:27214605

  7. Identification of phosphoproteins in Arabidopsis thaliana leaves using polyethylene glycol fractionation, immobilized metal-ion affinity chromatography, two-dimensional gel electrophoresis and mass spectrometry.

    PubMed

    Aryal, Uma K; Krochko, Joan E; Ross, Andrew R S

    2012-01-01

    Reversible protein phosphorylation is a key regulatory mechanism in cells. Identification and characterization of phosphoproteins requires specialized enrichment methods, due to the relatively low abundance of these proteins, and is further complicated in plants by the high abundance of Rubisco in green tissues. We present a novel method for plant phosphoproteome analysis that depletes Rubisco using polyethylene glycol fractionation and utilizes immobilized metal-ion affinity chromatography to enrich phosphoproteins. Subsequent protein separation by one- and two-dimensional gel electrophoresis is further improved by extracting the PEG-fractionated protein samples with SDS/phenol and methanol/chloroform to remove interfering compounds. Using this approach, we identified 132 phosphorylated proteins in a partial Arabidopsis leaf extract. These proteins are involved in a range of biological processes, including CO(2) fixation, protein assembly and folding, stress response, redox regulation, and cellular metabolism. Both large and small subunits of Rubisco were phosphorylated at multiple sites, and depletion of Rubisco enhanced detection of less abundant phosphoproteins, including those associated with state transitions between photosystems I and II. The discovery of a phosphorylated form of AtGRP7, a self-regulating RNA-binding protein that affects floral transition, as well as several previously uncharacterized ribosomal proteins confirm the utility of this approach for phosphoproteome analysis and its potential to increase our understanding of growth and development in plants. PMID:22092075

  8. Quantitative Phosphoproteome Analysis of Lysophosphatidic Acid Induced Chemotaxis applying Dual-step ¹⁸O Labeling Coupled with Immobilized Metal-ion Affinity Chromatography

    SciTech Connect

    Ding, Shi-Jian; Wang, Yingchun; Jacobs, Jon M.; Qian, Weijun; Yang, Feng; Tolmachev, Aleksey V.; Du, Xiuxia; Wang, Wei; Moore, Ronald J.; Monroe, Matthew E.; Purvine, Samuel O.; Waters, Katrina M.; Heibeck, Tyler H.; Adkins, Joshua N.; Camp, David G.; Klemke, Richard L.; Smith, Richard D.

    2008-10-01

    Reversible protein phosphorylation is a central cellular regulatory mechanism in modulating protein activity and propagating signals within cellular pathways and networks. Development of more effective methods for the simultaneous identification of phosphorylation sites and quantification of temporal changes in protein phosphorylation could provide important insights into molecular signaling mechanisms in a variety of different cellular processes. Here we present an integrated quantitative phosphoproteomics approach and its applications for comparative analysis of Cos-7 cells in response to lysophosphatidic acid (LPA) gradient stimulation. The approach combines trypsin-catalyzed 16O/18O labeling plus 16O/18O-methanol esterification labeling for quantitation, a macro- Immobilized Metal-ion Affinity Chromatography trap for phosphopeptide enrichment, and a monolithic capillary column with integrated electrospray emitter. LC separation and MS/MS is followed by neutral loss-dependent MS/MS/MS for phosphopeptide identification using a linear ion trap (LTQ)-FT mass spectrometer and complementary searching algorithms for interpreting MS/MS spectra. Protein phosphorylation involved in various signaling pathways of cell migration were identified and quantified, such as mitogen-activated protein kinase 1, dual-specificity mitogen-activated protein kinase kinase 2, and dual-specificity tyrosine-phosphorylation regulated kinase 1b, and a number of Rho GTPase-activating proteins. These results demonstrate the efficiency of this quantitative phosphoproteomics approach and its application for rapid discovery of phosphorylation events associated with gradient sensing and cell chemotaxis.

  9. The immobilization of recombinant human tropoelastin on metals using a plasma-activated coating to improve the biocompatibility of coronary stents.

    PubMed

    Waterhouse, Anna; Yin, Yongbai; Wise, Steven G; Bax, Daniel V; McKenzie, David R; Bilek, Marcela M M; Weiss, Anthony S; Ng, Martin K C

    2010-11-01

    Current endovascular stents have sub-optimal biocompatibility reducing their clinical efficacy. We previously demonstrated a plasma-activated coating (PAC) that covalently bound recombinant human tropoelastin (TE), a major regulator of vascular cells in vivo, to enhance endothelial cell interactions. We sought to develop this coating to enhance its mechanical properties and hemocompatibility for application onto coronary stents. The plasma vapor composition was altered by incorporating argon, nitrogen, hydrogen or oxygen to modulate coating properties. Coatings were characterized for 1) surface properties, 2) mechanical durability, 3) covalent protein binding, 4) endothelial cell interactions and 5) thrombogenicity. The N(2)/Ar PAC had optimal mechanical properties and did not delaminate after stent expansion. The N(2)/Ar PAC was mildly hydrophilic and covalently bound the highest proportion of TE, which enhanced endothelial cell proliferation. Acute thrombogenicity was assessed in a modified Chandler loop using human blood. Strikingly, the N(2)/Ar PAC alone reduced thrombus weight by ten-fold compared to 316L SS, a finding unaltered with immobilized TE. Serum soluble P-selectin was reduced on N(2)/Ar PAC and N(2)/Ar PAC + TE (p < 0.05), consistent with reduced platelet activation. We have demonstrated a coating for metal alloys with multifaceted biocompatibility that resists delamination and is non-thrombogenic, with implications for improving coronary stent efficacy. PMID:20708259

  10. Immobilized triazacyclononane derivatives as selective oxidation catalysts. Final technical report of DOE Award No. DE-FG02-99ER14968 with the University of Munich [Encapsulation of metal chelate and oxocatalysts in nanoporous hosts

    SciTech Connect

    Bein, Thomas

    2002-10-28

    This project deals with the covalent anchoring of various derivatives of triazacyclononane (TACN)ligands in the channels of period mesoporous materials and the catalytic activity of the corresponding metal complexes. Catalyst preparation, ligand immobilization, catalyst characterization, and catalyst performance in selective oxidation are discussed. A wide range of pendant variations on the TACN ligand can be synthesized, and ligands can be covalently bound to high surface area, pseudo-crystalline, silicate solids, before or after pendant addition.

  11. [PHEMA/PEI]-Cu(II) based immobilized metal affinity chromatography cryogels: Application on the separation of IgG from human plasma.

    PubMed

    Bakhshpour, Monireh; Derazshamshir, Ali; Bereli, Nilay; Elkak, Assem; Denizli, Adil

    2016-04-01

    The immobilized metal-affinity chromatography (IMAC) has gained significant interest as a widespread separation and purification tool for therapeutic proteins, nucleic acids and other biological molecules. The enormous potential of IMAC for proteins with natural surface exposed-histidine residues and for recombinant proteins with histidine clusters. Cryogels as monolithic materials have recently been proposed as promising chromatographic adsorbents for the separation of biomolecules in downstream processing. In the present study, IMAC cryogels have been synthesized and utilized for the adsorption and separation of immunoglobulin G (IgG) from IgG solution and whole human plasma. For this purpose, Cu(II)-ions were coupled to poly(hydroxyethyl methacrylate) PHEMA using poly(ethylene imine) (PEI) as the chelating ligand. In this study the cryogels formation optimized by the varied proportion of PEI from 1% to 15% along with different amounts of Cu (II) as chelating metal. The prepared cryogels were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The [PHEMA/PEI]-Cu(II) cryogels were assayed for their capability to bind the human IgG from aqueous solutions. The IMAC cryogels were found to have high affinity toward human IgG. The adsorption of human IgG was investigated onto the PHEMA/PEI cryogels with (10% PEI) and the concentration of Cu (II) varied as 10, 50, 100 and 150 mg/L. The separation of human IgG was achieved in one purification step at pH7.4. The maximum adsorption capacity was observed at the [PHEMA/PEI]-Cu(II) (10% PEI) with 72.28 mg/g of human IgG. The purification efficiency and human IgG purity were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). PMID:26838913

  12. Refined Sulfur Nanoparticles Immobilized in Metal-Organic Polyhedron as Stable Cathodes for Li-S Battery.

    PubMed

    Bai, Linyi; Chao, Dongliang; Xing, Pengyao; Tou, Li Juan; Chen, Zhen; Jana, Avijit; Shen, Ze Xiang; Zhao, Yanli

    2016-06-15

    The lithium-sulfur (Li-S) battery presents a promising rechargeable energy storage technology for the increasing energy demand in a worldwide range. However, current main challenges in Li-S battery are structural degradation and instability of the solid-electrolyte interphase caused by the dissolution of polysulfides during cycling, resulting in the corrosion and loss of active materials. Herein, we developed novel hybrids by employing metal-organic polyhedron (MOP) encapsulated PVP-functionalized sulfur nanoparticles (S@MOP), where the active sulfur component was efficiently encapsulated within the core of MOP and PVP as a surfactant was helpful to stabilize the sulfur nanoparticles and control the size and shape of corresponding hybrids during their syntheses. The amount of sulfur embedded into MOP could be controlled according to requirements. By using the S@MOP hybrids as cathodes, an obvious enhancement in the performance of Li-S battery was achieved, including high specific capacity with good cycling stability. The MOP encapsulation could enhance the utilization efficiency of sulfur. Importantly, the structure of the S@MOP hybrids was very stable, and they could last for almost 1000 cycles as cathodes in Li-S battery. Such high performance has rarely been obtained using metal-organic framework systems. The present approach opens up a promising route for further applications of MOP as host materials in electrochemical and energy storage fields. PMID:27243384

  13. Immobilized transition metal-based radical scavengers and their effect on durability of Aquivion® perfluorosulfonic acid membranes

    NASA Astrophysics Data System (ADS)

    D'Urso, C.; Oldani, C.; Baglio, V.; Merlo, L.; Aricò, A. S.

    2016-01-01

    A simple and broadly applicable preparation procedure to obtain silica-supported transition metal (namely Cr, Co and Mn)-based radical scavengers, containing sulfonic acid functionalities, is reported. These systems are widely characterised in terms of structure, bulk and surface composition and morphology by X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), X-Ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM). The scavenger material is loaded in ePTFE reinforced membranes prepared from Aquivion® perfluorosulfonic acid (PFSA) dispersions. All these composite membranes show longer lifetime in Accelerated Stress Tests (AST) and reduced fluoride release in Fenton's tests than the scavenger-free membranes without any loss in electrochemical performance. The Cr-scavenger-based polymer electrolyte shows a three-time larger stability than the pristine membrane.

  14. Protein immobilization techniques for microfluidic assays

    PubMed Central

    Kim, Dohyun; Herr, Amy E.

    2013-01-01

    Microfluidic systems have shown unequivocal performance improvements over conventional bench-top assays across a range of performance metrics. For example, specific advances have been made in reagent consumption, throughput, integration of multiple assay steps, assay automation, and multiplexing capability. For heterogeneous systems, controlled immobilization of reactants is essential for reliable, sensitive detection of analytes. In most cases, protein immobilization densities are maximized, while native activity and conformation are maintained. Immobilization methods and chemistries vary significantly depending on immobilization surface, protein properties, and specific assay goals. In this review, we present trade-offs considerations for common immobilization surface materials. We overview immobilization methods and chemistries, and discuss studies exemplar of key approaches—here with a specific emphasis on immunoassays and enzymatic reactors. Recent “smart immobilization” methods including the use of light, electrochemical, thermal, and chemical stimuli to attach and detach proteins on demand with precise spatial control are highlighted. Spatially encoded protein immobilization using DNA hybridization for multiplexed assays and reversible protein immobilization surfaces for repeatable assay are introduced as immobilization methods. We also describe multifunctional surface coatings that can perform tasks that were, until recently, relegated to multiple functional coatings. We consider the microfluidics literature from 1997 to present and close with a perspective on future approaches to protein immobilization. PMID:24003344

  15. Immobilized fluid membranes for gas separation

    DOEpatents

    Liu, Wei; Canfield, Nathan L; Zhang, Jian; Li, Xiaohong Shari; Zhang, Jiguang

    2014-03-18

    Provided herein are immobilized liquid membranes for gas separation, methods of preparing such membranes and uses thereof. In one example, the immobilized membrane includes a porous metallic host matrix and an immobilized liquid fluid (such as a silicone oil) that is immobilized within one or more pores included within the porous metallic host matrix. The immobilized liquid membrane is capable of selective permeation of one type of molecule (such as oxygen) over another type of molecule (such as water). In some examples, the selective membrane is incorporated into a device to supply oxygen from ambient air to the device for electrochemical reactions, and at the same time, to block water penetration and electrolyte loss from the device.

  16. Are Metals Emitted from Electronic Cigarettes a Reason for Health Concern? A Risk-Assessment Analysis of Currently Available Literature

    PubMed Central

    Farsalinos, Konstantinos E.; Voudris, Vassilis; Poulas, Konstantinos

    2015-01-01

    Background: Studies have found that metals are emitted to the electronic cigarette (EC) aerosol. However, the potential health impact of exposure to such metals has not been adequately defined. The purpose of this study was to perform a risk assessment analysis, evaluating the exposure of electronic cigarette (EC) users to metal emissions based on findings from the published literature. Methods: Two studies were found in the literature, measuring metals emitted to the aerosol from 13 EC products. We estimated that users take on average 600 EC puffs per day, but we evaluated the daily exposure from 1200 puffs. Estimates of exposure were compared with the chronic Permissible Daily Exposure (PDE) from inhalational medications defined by the U.S. Pharmacopeia (cadmium, chromium, copper, lead and nickel), the Minimal Risk Level (MRL) defined by the Agency for Toxic Substances and Disease Registry (manganese) and the Recommended Exposure Limit (REL) defined by the National Institute of Occupational Safety and Health (aluminum, barium, iron, tin, titanium, zinc and zirconium). Results: The average daily exposure from 13 EC products was 2.6 to 387 times lower than the safety cut-off point of PDEs, 325 times lower than the safety limit of MRL and 665 to 77,514 times lower than the safety cut-off point of RELs. Only one of the 13 products was found to result in exposure 10% higher than PDE for one metal (cadmium) at the extreme daily use of 1200 puffs. Significant differences in emissions between products were observed. Conclusions: Based on currently available data, overall exposure to metals from EC use is not expected to be of significant health concern for smokers switching to EC use, but is an unnecessary source of exposure for never-smokers. Metal analysis should be expanded to more products and exposure can be further reduced through improvements in product quality and appropriate choice of materials. PMID:25988311

  17. Alumina polymorphs affect the metal immobilization effect when beneficially using copper-bearing industrial sludge for ceramics.

    PubMed

    Tang, Yuanyuan; Lu, Xiuqing; Shih, Kaimin

    2014-12-01

    The feasibility of recycling copper-bearing industrial sludge as a part of ceramic raw materials was evaluated through thermal interaction of sludge with aluminum-rich precursors. To observe copper incorporation mechanism, mixtures of copper-bearing sludge with alumina polymorphs (γ-Al2O3 and α-Al2O3) were fired between 750 and 1250°C. Different copper-hosting phases were identified by X-ray diffraction, and CuAl2O4 was found to be the predominant phase throughout the reactions. The experimental results indicate different CuAl2O4 initiating temperatures for two alumina materials, and the optimal temperature for CuAl2O4 formation is around 1100°C. To monitor the stabilization effect, prolonged leaching tests were carried out to leach sintered products for up to 20d. The results clearly demonstrate a substantial decrease in copper leachability for products with higher CuAl2O4 content formed from both alumina precursors despite their different sintering behavior. Meanwhile, the leachability of aluminum was much lower than that of copper, and it decreased by more than fourfold through the formation of CuAl2O4 spinel in γ-Al2O3 system. This study clearly indicates spinel formation as the most crucial metal stabilization mechanism when sintering multiphase copper-bearing industrial sludge with aluminum-rich ceramic raw materials, and suggests a promising and reliable technique for reusing industrial sludge. PMID:25299935

  18. Metaproteomics Identifies the Protein Machinery Involved in Metal and Radionuclide Reduction in Subsurface Microbiomes and Elucidates Mechanisms and U(VI) Reduction Immobilization

    SciTech Connect

    Pfiffner, Susan M.; Löffler, Frank; Ritalahti, Kirsti; Sayler, Gary; Layton, Alice; Hettich, Robert

    2015-08-31

    The overall goal for this funded project was to develop and exploit environmental metaproteomics tools to identify biomarkers for monitoring microbial activity affecting U speciation at U-contaminated sites, correlate metaproteomics profiles with geochemical parameters and U(VI) reduction activity (or lack thereof), elucidate mechanisms contributing to U(VI) reduction, and provide remediation project managers with additional information to make science-based site management decisions for achieving cleanup goals more efficiently. Although significant progress has been made in elucidating the microbiology contribution to metal and radionuclide reduction, the cellular components, pathway(s), and mechanisms involved in U trans-formation remain poorly understood. Recent advances in (meta)proteomics technology enable detailed studies of complex samples, including environmental samples, which differ between sites and even show considerable variability within the same site (e.g., the Oak Ridge IFRC site). Additionally, site-specific geochemical conditions affect microbial activity and function, suggesting generalized assessment and interpretations may not suffice. This research effort integrated current understanding of the microbiology and biochemistry of U(VI) reduction and capitalize on advances in proteomics technology made over the past few years. Field-related analyses used Oak Ridge IFRC field ground water samples from locations where slow-release substrate biostimulation has been implemented to accelerate in situ U(VI) reduction rates. Our overarching hypothesis was that the metabolic signature in environmental samples, as deciphered by the metaproteome measurements, would show a relationship with U(VI) reduction activity. Since metaproteomic and metagenomic characterizations were computationally challenging and time-consuming, we used a tiered approach that combines database mining, controlled laboratory studies, U(VI) reduction activity measurements, phylogenetic

  19. Collaborative Triple Framework Interpenetration and Immobilization of Open Metal Sites within a Microporous Mixed Metal-Organic Framework for Highly Selective Gas Adsorption

    SciTech Connect

    Zhang, Zhangjing; Xiang, Sheng-Chang; Hong, Kunlun; Das, Madhab; Arman, Hadi; Garcia, Maya; Mondal, Jalal; Chen, Banglin

    2012-01-01

    A three-dimensional triply interpenetrated mixed metal-organic framework, Zn{sub 2}(BBA){sub 2}(CuPyen) {center_dot} G{sub x} (M'MOF-20; BBA = biphenyl-4,4'-dicarboxylate; G = guest solvent molecules), of primitive cubic net was obtained through the solvothermal reaction of Zn(NO{sub 3}){sub 2}, biphenyl-4,4'-dicarboxylic acid, and the salen precursor Cu(PyenH{sub 2})(NO{sub 3}){sub 2} by a metallo-ligand approach. The triple framework interpenetration has stabilized the framework in which the activated M'MOF-20a displays type-I N{sub 2} gas sorption behavior with a Langmuir surface area of 62 m{sup 2} g{sup -1}. The narrow pores of about 3.9 {angstrom} and the open metal sites on the pore surfaces within M'MOF-20a collaboratively induce its highly selective C{sub 2}H{sub 2}/CH{sub 4} and CO{sub 2}/CH{sub 4} gas separation at ambient temperature.

  20. Immobilization of heavy metal ions (CuII, CdII, NiII, and PbII) by broiler litter-derived biochars in water and soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chars, a form of environmental black carbon resulting from incomplete burning of biomass, can immobilize organic contaminants by both surface adsorption and partitioning mechanisms. The predominance of each sorption mechanism depends upon the proportion of organic to carbonized fractions comprising...

  1. Rational Design of Nanoparticle Platforms for "Cutting-the-Fat": Covalent Immobilization of Lipase, Glycerol Kinase, and Glycerol-3-Phosphate Oxidase on Metal Nanoparticles.

    PubMed

    Aggarwal, V; Pundir, C S

    2016-01-01

    The aggregates of nanoparticles (NPs) are considered better supports for the immobilization of enzymes, as these promote enzyme kinetics, due to their unusual but favorable properties such as larger surface area to volume ratio, high catalytic efficiency of certain immobilized enzymes, non-toxicity of some of the nanoparticle matrices, high stability, strong adsorption of the enzyme of interest by a number of different approaches, and faster electron transportability. Co-immobilization of multiple enzymes required for a multistep reaction cascade on a single support is more efficient than separately immobilizing the corresponding enzymes and mixing them physically, since products of one enzyme could serve as reactants for another. These products can diffuse much more easily between enzymes on the same particle than diffusion from one particle to the next, in the reaction medium. Thus, co-immobilization of enzymes onto NP aggregates is expected to produce faster kinetics than their individual immobilizations on separate matrices. Lipase, glycerol kinase, and glycerol-3-phosphate oxidase are required for lipid analysis in a cascade reaction, and we describe the co-immobilization of these three enzymes on nanocomposites of zinc oxide nanoparticles (ZnONPs)-chitosan (CHIT) and gold nanoparticles-polypyrrole-polyindole carboxylic acid (AuPPy-Pin5COOH) which are electrodeposited on Pt and Au electrodes, respectively. The kinetic properties and analytes used for amperometric determination of TG are fully described for others to practice in a trained laboratory. Cyclic voltammetry, scanning electron microscopy, Fourier transform infra-red spectra, and electrochemical impedance spectra confirmed their covalent co-immobilization onto electrode surfaces through glutaraldehyde coupling on CHIT-ZnONPs and amide bonding on AuPPy/Pin5COOH. The combined activities of co-immobilized enzymes was tested amperometrically, and these composite nanobiocatalysts showed optimum activity

  2. Plutonium Immobilization Project -- Can loading

    SciTech Connect

    Kriikku, E.

    2000-01-18

    The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP scope includes unloading transportation containers, preparing the feed streams, converting the metal feed to an oxide, adding the ceramic precursors, pressing the pucks, inspecting pucks, and sintering pucks. The PIP scope also includes loading the pucks into metal cans, sealing the cans, inspecting the cans, loading the cans into magazines, loading magazines into Defense Waste Processing Facility (DWPF) canisters, and transporting the canisters to the DWPF. The DWPF fills the canister with a mixture of high level radioactive waste and glass for permanent storage. Due to the radiation, remote equipment must perform PIP operations in a contained environment.

  3. SERR Spectroelectrochemical Study of Cytochrome cd1 Nitrite Reductase Co-Immobilized with Physiological Redox Partner Cytochrome c552 on Biocompatible Metal Electrodes

    PubMed Central

    Silveira, Célia M.; Quintas, Pedro O.; Moura, Isabel; Moura, José J. G.; Hildebrandt, Peter; Almeida, M. Gabriela; Todorovic, Smilja

    2015-01-01

    Cytochrome cd1 nitrite reductases (cd1NiRs) catalyze the one-electron reduction of nitrite to nitric oxide. Due to their catalytic reaction, cd1NiRs are regarded as promising components for biosensing, bioremediation and biotechnological applications. Motivated by earlier findings that catalytic activity of cd1NiR from Marinobacter hydrocarbonoclasticus (Mhcd1) depends on the presence of its physiological redox partner, cytochrome c552 (cyt c552), we show here a detailed surface enhanced resonance Raman characterization of Mhcd1 and cyt c552 attached to biocompatible electrodes in conditions which allow direct electron transfer between the conducting support and immobilized proteins. Mhcd1 and cyt c552 are co-immobilized on silver electrodes coated with self-assembled monolayers (SAMs) and the electrocatalytic activity of Ag // SAM // Mhcd1 // cyt c552 and Ag // SAM // cyt c552 // Mhcd1 constructs is tested in the presence of nitrite. Simultaneous evaluation of structural and thermodynamic properties of the immobilized proteins reveals that cyt c552 retains its native properties, while the redox potential of apparently intact Mhcd1 undergoes a ~150 mV negative shift upon adsorption. Neither of the immobilization strategies results in an active Mhcd1, reinforcing the idea that subtle and very specific interactions between Mhcd1 and cyt c552 govern efficient intermolecular electron transfer and catalytic activity of Mhcd1. PMID:26091174

  4. SERR Spectroelectrochemical Study of Cytochrome cd1 Nitrite Reductase Co-Immobilized with Physiological Redox Partner Cytochrome c552 on Biocompatible Metal Electrodes.

    PubMed

    Silveira, Célia M; Quintas, Pedro O; Moura, Isabel; Moura, José J G; Hildebrandt, Peter; Almeida, M Gabriela; Todorovic, Smilja

    2015-01-01

    Cytochrome cd1 nitrite reductases (cd1NiRs) catalyze the one-electron reduction of nitrite to nitric oxide. Due to their catalytic reaction, cd1NiRs are regarded as promising components for biosensing, bioremediation and biotechnological applications. Motivated by earlier findings that catalytic activity of cd1NiR from Marinobacter hydrocarbonoclasticus (Mhcd1) depends on the presence of its physiological redox partner, cytochrome c552 (cyt c552), we show here a detailed surface enhanced resonance Raman characterization of Mhcd1 and cyt c552 attached to biocompatible electrodes in conditions which allow direct electron transfer between the conducting support and immobilized proteins. Mhcd1 and cyt c552 are co-immobilized on silver electrodes coated with self-assembled monolayers (SAMs) and the electrocatalytic activity of Ag // SAM // Mhcd1 // cyt c552 and Ag // SAM // cyt c552 // Mhcd1 constructs is tested in the presence of nitrite. Simultaneous evaluation of structural and thermodynamic properties of the immobilized proteins reveals that cyt c552 retains its native properties, while the redox potential of apparently intact Mhcd1 undergoes a ~150 mV negative shift upon adsorption. Neither of the immobilization strategies results in an active Mhcd1, reinforcing the idea that subtle and very specific interactions between Mhcd1 and cyt c552 govern efficient intermolecular electron transfer and catalytic activity of Mhcd1. PMID:26091174

  5. Penile Incarceration with Metallic Foreign Bodies: Management and Review of Literature

    PubMed Central

    Trivedi, Sameer; Attam, Amit; Kerketa, Arun; Daruka, Navin; Behre, Bharat; Agrawal, Abhinav; Rathi, Sudhir; Dwivedi, U.S.

    2013-01-01

    Introduction Penile strangulation from constricting metallic objects disorders is an uncommon urological emergency which requires prompt intervention to prevent complications. The treatment modalities are diverse and characterized by lack of consensus. Material and Methods Three cases with penile incarceration due to constricting metallic objects who presented to our department were included in this study. All 3 patients required different management options highlighting the diversity of clinical presentation and need for customization of treatment as per the clinical scenario. Results The 3 patients required different approach for treatment. First patient could be managed by degloving of penile skin while second patient required mechanical removal of the foreign body and debridement of local necrotic tissues. The third patient had to undergo excision of gangrenous penile skin and skin grafting. Conclusion The study emphasizes the diversity of clinical presentations and the need for employing different surgical techniques to achieve the desired results. PMID:24917757

  6. Rapid tooling for functional prototyping of metal mold processes: Literature review on cast tooling

    SciTech Connect

    Baldwin, M.D.; Hochanadel, P.W.

    1995-11-01

    This report is a literature review on cast tooling with the general focus on AISI H13 tool steel. The review includes processing of both wrought and cast H13 steel along with the accompanying microstructures. Also included is the incorporation of new rapid prototyping technologies, such as Stereolithography and Selective Laser Sintering, into the investment casting of tool steel. The limiting property of using wrought or cast tool steel for die casting is heat checking. Heat checking is addressed in terms of testing procedures, theories regarding the mechanism, and microstructural aspects related to the cracking.

  7. Metabolic Responses of Bacterial Cells to Immobilization.

    PubMed

    Żur, Joanna; Wojcieszyńska, Danuta; Guzik, Urszula

    2016-01-01

    In recent years immobilized cells have commonly been used for various biotechnological applications, e.g., antibiotic production, soil bioremediation, biodegradation and biotransformation of xenobiotics in wastewater treatment plants. Although the literature data on the physiological changes and behaviour of cells in the immobilized state remain fragmentary, it is well documented that in natural settings microorganisms are mainly found in association with surfaces, which results in biofilm formation. Biofilms are characterized by genetic and physiological heterogeneity and the occurrence of altered microenvironments within the matrix. Microbial cells in communities display a variety of metabolic differences as compared to their free-living counterparts. Immobilization of bacteria can occur either as a natural phenomenon or as an artificial process. The majority of changes observed in immobilized cells result from protection provided by the supports. Knowledge about the main physiological responses occurring in immobilized cells may contribute to improving the efficiency of immobilization techniques. This paper reviews the main metabolic changes exhibited by immobilized bacterial cells, including growth rate, biodegradation capabilities, biocatalytic efficiency and plasmid stability. PMID:27455220

  8. Direct Metal Laser Sintering Titanium Dental Implants: A Review of the Current Literature

    PubMed Central

    Mangano, F.; Chambrone, L.; van Noort, R.; Miller, C.; Hatton, P.; Mangano, C.

    2014-01-01

    Statement of Problem. Direct metal laser sintering (DMLS) is a technology that allows fabrication of complex-shaped objects from powder-based materials, according to a three-dimensional (3D) computer model. With DMLS, it is possible to fabricate titanium dental implants with an inherently porous surface, a key property required of implantation devices. Objective. The aim of this review was to evaluate the evidence for the reliability of DMLS titanium dental implants and their clinical and histologic/histomorphometric outcomes, as well as their mechanical properties. Materials and Methods. Electronic database searches were performed. Inclusion criteria were clinical and radiographic studies, histologic/histomorphometric studies in humans and animals, mechanical evaluations, and in vitro cell culture studies on DMLS titanium implants. Meta-analysis could be performed only for randomized controlled trials (RCTs); to evaluate the methodological quality of observational human studies, the Newcastle-Ottawa scale (NOS) was used. Results. Twenty-seven studies were included in this review. No RCTs were found, and meta-analysis could not be performed. The outcomes of observational human studies were assessed using the NOS: these studies showed medium methodological quality. Conclusions. Several studies have demonstrated the potential for the use of DMLS titanium implants. However, further studies that demonstrate the benefits of DMLS implants over conventional implants are needed. PMID:25525434

  9. Direct metal laser sintering titanium dental implants: a review of the current literature.

    PubMed

    Mangano, F; Chambrone, L; van Noort, R; Miller, C; Hatton, P; Mangano, C

    2014-01-01

    Statement of Problem. Direct metal laser sintering (DMLS) is a technology that allows fabrication of complex-shaped objects from powder-based materials, according to a three-dimensional (3D) computer model. With DMLS, it is possible to fabricate titanium dental implants with an inherently porous surface, a key property required of implantation devices. Objective. The aim of this review was to evaluate the evidence for the reliability of DMLS titanium dental implants and their clinical and histologic/histomorphometric outcomes, as well as their mechanical properties. Materials and Methods. Electronic database searches were performed. Inclusion criteria were clinical and radiographic studies, histologic/histomorphometric studies in humans and animals, mechanical evaluations, and in vitro cell culture studies on DMLS titanium implants. Meta-analysis could be performed only for randomized controlled trials (RCTs); to evaluate the methodological quality of observational human studies, the Newcastle-Ottawa scale (NOS) was used. Results. Twenty-seven studies were included in this review. No RCTs were found, and meta-analysis could not be performed. The outcomes of observational human studies were assessed using the NOS: these studies showed medium methodological quality. Conclusions. Several studies have demonstrated the potential for the use of DMLS titanium implants. However, further studies that demonstrate the benefits of DMLS implants over conventional implants are needed. PMID:25525434

  10. Immobilization and characterization of a thermostable lipase.

    PubMed

    Song, Chongfu; Sheng, Liangquan; Zhang, Xiaobo

    2013-12-01

    Lipases have found a number of commercial applications. However, thermostable lipase immobilized on nanoparticle is not extensively characterized. In this study, a recombinant thermostable lipase (designated as TtL) from Thermus thermophilus WL was expressed in Escherichia coli and immobilized onto 3-APTES-modified Fe3O4@SiO2 supermagnetic nanoparticles. Based on analyses with tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis, X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer observation, the diameter of immobilized lipase nanoparticle was 18.4 (± 2.4) nm, and its saturation magnetization value was 52.3 emu/g. The immobilized lipase could be separated from the reaction medium rapidly and easily in a magnetic field. The biochemical characterizations revealed that, comparing with the free one, the immobilized lipase exhibited better resistance to temperature, pH, metal ions, enzyme inhibitors, and detergents. The K m value for the immobilized TtL (2.56 mg/mL) was found to be lower than that of the free one (3.74 mg/mL), showing that the immobilization improved the affinity of lipase for its substrate. In addition, the immobilized TtL exhibited good reusability. It retained more than 79.5 % of its initial activity after reusing for 10 cycles. Therefore, our study presented that the possibility of the efficient reuse of the thermostable lipase immobilized on supermagnetic nanoparticles made it attractive from the viewpoint of practical application. PMID:23748908

  11. Immobilization of ultrafine bimetallic Ni-Pt nanoparticles inside the pores of metal-organic frameworks as efficient catalysts for dehydrogenation of alkaline solution of hydrazine.

    PubMed

    Cao, Nan; Yang, Lan; Dai, Hongmei; Liu, Teng; Su, Jun; Wu, Xiaojun; Luo, Wei; Cheng, Gongzhen

    2014-10-01

    We report a facile liquid impregnation approach for immobilization of ultrafine bimetallic Ni-Pt nanoparticles (NPs) inside the pores of MIL-101. The methods of powder X-ray diffraction, N2 physisorption, X-ray photoelectron spectroscopy, transmission electron microscopy, and inductively coupled plasma-atomic emission spectroscopy were employed to characterize the NiPt@MIL-101 catalysts and further indicated the as-synthesized Ni-Pt NPs were confined in the pores of MIL-101. These as-synthesized bimetallic NiPt@MIL-101 NPs exhibit exceedingly high catalytic activity, selectivity, and durability toward hydrogen generation from alkaline solution of hydrazine. PMID:25197778

  12. Biosynthesis and Immobilization of Biofunctional Allophycocyanin

    PubMed Central

    Chen, Yingjie; Liu, Shaofang; Cui, Yulin; Jiang, Peng; Chen, Huaxin; Li, Fuchao; Qin, Song

    2011-01-01

    The holo-allophycocyanin-α subunit, which has various reported pharmacological uses, was biosynthesized with both Strep-II-tag and His-tag at the N-terminal in Escherichia coli. The streptavidin-binding ability resulting from the Strep II-tag was confirmed by Western blot. Additionally, the metal-chelating ability deriving from the His-tag not only facilitated its purification by immobilized metal-ion affinity chromatography but also promoted its immobilization on Zn (II)-decorated silica-coated magnetic nanoparticles. The holo-allophycocyanin-α subunit with streptavidin-binding ability was thereby immobilized on magnetic nanoparticles. Magnetic nanoparticles are promising as drug delivery vehicles for targeting and locating at tumors. Thus, based on genetic engineering and nanotechnology, we provide a potential strategy to facilitate the biomodification and targeted delivery of pharmacological proteins. PMID:23008737

  13. Short communication: Identification of iron-binding peptides from whey protein hydrolysates using iron (III)-immobilized metal ion affinity chromatography and reversed phase-HPLC-tandem mass spectrometry.

    PubMed

    Cruz-Huerta, Elvia; Martínez Maqueda, Daniel; de la Hoz, Lucia; da Silva, Vera S Nunes; Pacheco, Maria Teresa Bertoldo; Amigo, Lourdes; Recio, Isidra

    2016-01-01

    Peptides with iron-binding capacity obtained by hydrolysis of whey protein with Alcalase (Novozymes, Araucaria, PR, Brazil), pancreatin, and Flavourzyme (Novozymes) were identified. Hydrolysates were subjected to iron (III)-immobilized metal ion affinity chromatography, and the bound peptides were sequenced by mass spectrometry. Regardless of the enzyme used, the domains f(42-59) and f(125-137) from β-lactoglobulin enclosed most of identified peptides. This trend was less pronounced in the case of peptides derived from α-lactalbumin, with sequences deriving from diverse regions. Iron-bound peptides exhibited common structural characteristics, such as an abundance of Asp, Glu, and Pro, as revealed by mass spectrometry and AA analysis. In conclusion, this characterization of iron-binding peptides helps clarify the relationship between peptide structure and iron-chelating activity and supports the promising role of whey protein hydrolysates as functional ingredients in iron supplementation treatments. PMID:26601589

  14. Perinatal and Childhood Exposure to Cadmium, Manganese, and Metal Mixtures and Effects on Cognition and Behavior: A Review of Recent Literature

    PubMed Central

    Sanders, Alison P.; Henn, Birgit Claus; Wright, Robert O.

    2015-01-01

    Lead (Pb) and mercury (Hg) neurotoxicity is well established. In recent years, a growing body of evidence suggests that environmental exposure to other metals including arsenic (As), cadmium (Cd), manganese (Mn), and their mixtures also pose public health threats. In this paper we summarize the recent literature examining the relationship of prenatal and childhood environmental metal exposures with cognitive and behavioral outcomes in children. We conducted a literature search to identify epidemiologic studies that examined the relationship of Cd, Mn, and metal mixtures with children’s neurodevelopmental/cognitive and behavioral outcomes. We restricted the search to peer-reviewed studies published in English between January 2009 and March 2015. We identified a total of 31 articles of which 16, 17, and 16 studies examined the effects of Cd, Mn, or metal mixtures, respectively. Based on our review, there is suggestive evidence that prenatal/childhood Cd exposure may be associated with poorer cognition, but additional research is clearly needed. We found little evidence of behavioral effects of early life Cd exposure, and no studies found a significant relationship with attention deficit hyperactivity disorder. Studies of early life Mn exposure consistently reported negative impacts on both cognition and behavior. There is also growing evidence that co-exposure to multiple metals can result in increased neurotoxicity compared to single metal exposures, in particular during early life. Few studies have evaluated behavioral effects related to metal co-exposures. PMID:26231505

  15. Perinatal and Childhood Exposure to Cadmium, Manganese, and Metal Mixtures and Effects on Cognition and Behavior: A Review of Recent Literature.

    PubMed

    Sanders, Alison P; Claus Henn, Birgit; Wright, Robert O

    2015-09-01

    Lead (Pb) and mercury (Hg) neurotoxicity is well established. In recent years, a growing body of evidence suggests that environmental exposure to other metals including arsenic (As), cadmium (Cd), and manganese (Mn) and their mixtures also poses public health threats. In this paper, we summarize the recent literature examining the relationship of prenatal and childhood environmental metal exposures with cognitive and behavioral outcomes in children. We conducted a literature search to identify epidemiologic studies that examined the relationship of Cd, Mn, and metal mixtures with children's neurodevelopmental/cognitive and behavioral outcomes. We restricted the search to peer-reviewed studies published in English between January 2009 and March 2015. We identified a total of 31 articles of which 16, 17, and 16 studies examined the effects of Cd, Mn, or metal mixtures, respectively. Based on our review, there is suggestive evidence that prenatal/childhood Cd exposure may be associated with poorer cognition, but additional research is clearly needed. We found little evidence of behavioral effects of early life Cd exposure, and no studies found a significant relationship with attention deficit hyperactivity disorder. Studies of early life Mn exposure consistently reported negative impacts on both cognition and behavior. There is also growing evidence that co-exposure to multiple metals can result in increased neurotoxicity compared to single-metal exposure, in particular during early life. Few studies have evaluated behavioral effects related to metal co-exposure. PMID:26231505

  16. Immobilized lipid-bilayer materials

    DOEpatents

    Sasaki, Darryl Y.; Loy, Douglas A.; Yamanaka, Stacey A.

    2000-01-01

    A method for preparing encapsulated lipid-bilayer materials in a silica matrix comprising preparing a silica sol, mixing a lipid-bilayer material in the silica sol and allowing the mixture to gel to form the encapsulated lipid-bilayer material. The mild processing conditions allow quantitative entrapment of pre-formed lipid-bilayer materials without modification to the material's spectral characteristics. The method allows for the immobilization of lipid membranes to surfaces. The encapsulated lipid-bilayer materials perform as sensitive optical sensors for the detection of analytes such as heavy metal ions and can be used as drug delivery systems and as separation devices.

  17. Nonporous magnetic materials as enzyme supports: studies with immobilized chymotrypsin.

    PubMed

    Munro, P A; Dunnill, P; Lilly, M D

    1977-01-01

    Chymotrypsin has been immobilized to several nonporous magnetic materials. Nickel particles were considered to be most suitable as immobilized enzyme supports. Chymotrypsin immobilized to nonporous magnetic supports was not fouled significantly by either whole milk or clarified yeast homogenate. AE-cellulose-chymotrypsin was rapidly fouled by both these materials and chymotrypsin immobilized to acrylic-based ion exchangers was slowly fouled. Immobilized enzyme activity was found to be inversely proportional to particle diameter for nonporous rock magnetic particles. Immobilization by adsorption and then glutaraldehyde crosslinking was used to produce controlled amounts of chymotrypsin on the particles. Esterolytic activity increased with enzyme loading but caseinolytic activity did not increase. Chymotrypsin is inhibited by metal ions from the magnetic supports. It is partially protected by use of a preliminary protein coating and may be reactivated by incubation with EDTA or BSA. PMID:14743

  18. Plutonium immobilization -- Can loading

    SciTech Connect

    Kriikku, E.

    2000-02-17

    The Savannah River Site (SRS) will immobilize excess plutonium in the proposed Plutonium Immobilization Project (PIP). The PIP adds the excess plutonium to ceramic pucks, loads the pucks into cans, and places the cans into DWPF canisters. This paper discusses the PIP process steps, the can loading conceptual design, can loading equipment design, and can loading work completed.

  19. Kinetics as a tool to assess the immobilization of soil trace metals by binding phase amendments for in situ remediation purposes.

    PubMed

    Varrault, Gilles; Bermond, Alain

    2011-08-30

    Many soil remediation techniques consist in decreasing the mobility of trace metals by means of adding trace metal binding phases. For this study, whose aim is to assess the efficiency of soil remediation method by binding phase amendment, a kinetic fractionation method that provides the labile and slowly labile trace metal amounts in soil has been introduced. Manganese oxides (vernadite) and insolubilized humic acids (IHA) have been used as binding phases for the remediation of four heavily polluted soils. Vernadite amendments are effective for lead and cadmium remediation, whereas IHA amendments are only effective for copper remediation. In most cases, the labile metal fractions decrease dramatically in amended soils (up to 50%); on the other hand, the amounts of total extracted metal near the point of thermodynamic equilibrium often show no significant difference between the amended soil and the control soil. These results highlight the utility of kinetic fractionation in assessing the efficiency of soil remediation techniques and, more generally, in evaluating trace metal mobility in soils and its potential advantages compared to extraction schemes performed under equilibrium conditions. In the future, this kinetic method could be considerably simplified so as to consume much less time allowing its routine use. PMID:21708424

  20. Preparation of core-shell structure Fe3 O4 @SiO2 superparamagnetic microspheres immoblized with iminodiacetic acid as immobilized metal ion affinity adsorbents for His-tag protein purification.

    PubMed

    Ni, Qian; Chen, Bing; Dong, Shaohua; Tian, Lei; Bai, Quan

    2016-04-01

    The core-shell structure Fe3 O4 /SiO2 magnetic microspheres were prepared by a sol-gel method, and immobiled with iminodiacetic acid (IDA) as metal ion affinity ligands for protein adsorption. The size, morphology, magnetic properties and surface modification of magnetic silica nanospheres were characterized by various modern analytical instruments. It was shown that the magnetic silica nanospheres exhibited superparamagnetism with saturation magnetization values of up to 58.1 emu/g. Three divalent metal ions, Cu(2+) , Ni(2+) and Zn(2+) , were chelated on the Fe3 O4 @SiO2 -IDA magnetic microspheres to adsorb lysozyme. The results indicated that Ni(2+) -chelating magnetic microspheres had the maximum adsorption capacity for lysozyme of 51.0 mg/g, adsorption equilibrium could be achieved within 60 min and the adsorbed protein could be easily eluted. Furthermore, the synthesized Fe3 O4 @SiO2 -IDA-Ni(2+) magnetic microspheres were successfully applied for selective enrichment lysozyme from egg white and His-tag recombinant Homer 1a from the inclusion extraction expressed in Escherichia coli. The result indicated that the magnetic microspheres showed unique characteristics of high selective separation behavior of protein mixture, low nonspecific adsorption, and easy handling. This demonstrates that the magnetic silica microspheres can be used efficiently in protein separation or purification and show great potential in the pretreatment of the biological sample. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26268650

  1. Giant-cell interstitial pneumonia and hard-metal pneumoconiosis. A clinicopathologic study of four cases and review of the literature

    SciTech Connect

    Ohori, N.P.; Sciurba, F.C.; Owens, G.R.; Hodgson, M.J.; Yousem, S.A.

    1989-07-01

    We report four cases of giant-cell interstitial pneumonia that occurred in association with exposure to hard metals. All patients presented with chronic interstitial lung disease and had open-lung biopsies that revealed marked interstitial fibrosis, cellular interstitial infiltrates, and prominent intraalveolar macrophages as well as giant cells displaying cellular cannibalism. We also review the literature to determine the sensitivity and specificity of giant-cell interstitial pneumonia for hard-metal pneumoconiosis. Although hard-metal pneumoconiosis may take the form of usual interstitial pneumonia, desquamative interstitial pneumonia, and giant-cell interstitial pneumonia, the finding of giant-cell interstitial pneumonia is almost pathognomonic of hard-metal disease and should provoke an investigation of occupational exposure. 25 references.

  2. Penicillium digitatum immobilized on pumice stone as a new solid phase extractor for preconcentration and/or separation of trace metals in environmental samples.

    PubMed

    Baytak, Sitki; Kendüzler, Erdal; Türker, Ali Rehber; Gök, Nuray

    2008-05-30

    This study presents a column solid phase extraction procedure based on column biosorption of Cu(II), Zn(II) and Pb(II) ions on Penicillium digitatum immobilized on pumice stone. The analytes were determined by flame atomic absorption spectrometry (FAAS). The optimum conditions such as: pH values, amount of solid phase, elution solution and flow rate of sample solution were evaluated for the quantitative recovery of the analytes. The effect of interfering ions on the recovery of the analytes has also been investigated. The recoveries of copper, zinc and lead under the optimum conditions were found to be 97+/-2, 98+/-2 and 98+/-2%, respectively, at 95% confidence level. For the analytes, 50-fold preconcentration was obtained. The analytical detection limits for Cu(II), Zn(II) and Pb(II) were 1.8, 1.3 and 5.8 ng mL(-1), respectively. The proposed procedure was applied for the determination of copper, zinc and lead in dam water, waste water, spring water, parsley and carrot. The accuracy of the procedure was checked by determining copper, zinc and lead in standard reference tea samples (GBW-07605). PMID:17950994

  3. Reduction and immobilization of radionuclides and toxic metal ions using combined zero valent iron and anaerobic bacteria. Year one technical progress report

    SciTech Connect

    Weathers, L.J.; Katz, L.E.

    1997-10-01

    'The objective of this project is to design a combined abiotic/microbial, reactive, permeable, in-situ barrier with sufficient reductive potential to prevent downgradient migration of toxic metal ions. The field-scale application of this technology would utilize anaerobic digester sludge, Fe(O) particles for supporting anaerobic biofilms, and suitable aquifer material for construction of the barrier. The major goals for Year 1 were to establish the sulfate reducing mixed culture, to obtain sources of iron metal, and to conduct background experiments which will establish baseline rates for abiotic chromium reduction rates. Research completed to date is described.'

  4. Behaviour of heavy metals immobilized by co-melting treatment of sewage sludge ash and municipal solid waste incinerator fly ash.

    PubMed

    Lin, Kae-Long; Huang, Wu-Jang; Chen, Kuan-Chung; Chow, Jing-Dong; Chen, His-Jien

    2009-10-01

    This study elucidates the behaviour of heavy metals in slag produced from four different sewage sludge ashes mixed with municipal solid waste incinerator fly ash and then co-melted. Experimental results indicate that sewage sludge ashes consisted of SiO(2), CaO, and Al(2)O(3). Fly ash consisted of CaO, Na(2)O and SO(3). The speciation of sewage sludge ashes indicates that the ashes contained quartz and AlPO(4). The speciation in fly ash consisted of anhydrite, microcline, calcium chloride, sylvite and halite. The leaching behaviours of sewage sludge ashes met the Taiwan Environmental Protection Administration's regulatory standards. The fly ash had high concentrations of Zn and Pb; however, the leaching of these metals was low. The major components of synthetic slags were SiO(2) (33.5-54.0%), CaO (21.4-36.7%), and Al(2)O(3) (8.1-15.7%). The X-ray diffraction patterns of co-melted slags demonstrate that the slags contained significant amounts of glass. Most heavy metals can be fixed in a net-like structure; thus, they can not be extracted easily. The toxicity characteristic leaching procedure (TCLP) leaching concentrations for target metals in all slags met the Taiwan Environmental Protection Administration's regulatory standards. PMID:19470538

  5. Immobilization induced hypercalcemia

    PubMed Central

    Cano-Torres, Edgar Alonso; González-Cantú, Arnulfo; Hinojosa-Garza, Gabriela; Castilleja-Leal, Fernando

    2016-01-01

    Summary Immobilization hypercalcemia is an uncommon diagnosis associated with increased bone remodeling disorders and conditions associated with limited movement such as medullar lesions or vascular events. Diagnosis requires an extensive evaluation to rule out other causes of hypercalcemia. This is a report of a woman with prolonged immobilization who presented with severe hypercalcemia. This case contributes to identification of severe hypercalcemia as a result of immobility and the description of bone metabolism during this state. PMID:27252745

  6. Physicochemical interaction of Escherichia coli cell envelopes and Bacillus subtilis cell walls with two clays and ability of the composite to immobilize heavy metals from solution.

    PubMed Central

    Walker, S G; Flemming, C A; Ferris, F G; Beveridge, T J; Bailey, G W

    1989-01-01

    Isolated Escherichia coli K-12 cell envelopes or Bacillus subtilis 168 cell walls were reacted with smectite or kaolinite clay in distilled deionized water (pH 6.0); unbound envelopes or walls were separated by sucrose density gradient centrifugation, and the extent of adsorption was calculated. At saturation, both clays adsorbed approximately 1.0 mg (dry weight) of envelopes or walls per mg (dry weight) of clay. Clays showed a preference for edge-on orientation with both walls and envelopes, which was indicative of an aluminum polynuclear bridging mechanism between the wall or envelope surface and the clay edge. The addition of heavy metals increased the incidence of planar surface orientations, which suggested that multivalent metal cation bridging was coming into play and was of increasing importance. The metal-binding capacity of isolated envelopes, walls, clays, and envelope-clay or wall-clay mixtures was determined by atomic absorption spectroscopy after exposure to aqueous 5.0 mM Ag+, Cu2+, Cd2+, Ni2+, Pb2+, Zn2+, and Cr3+ nitrate salt solutions at pHs determined by the buffering capacity of wall, envelope, clay, or composite system. The order of metal uptake was walls greater than envelopes greater than smectite clay greater than kaolinite clay for the individual components, and walls plus smectite greater than walls plus kaolinite greater than envelopes plus smectite greater than envelopes plus kaolinite for the mixtures. On a dry-weight basis, the envelope-clay and wall-clay mixtures bound 20 to 90% less metal than equal amounts of the individual components did.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:2516433

  7. Immobilized Cell and Enzyme Technology

    NASA Astrophysics Data System (ADS)

    Dunnill, P.

    1980-08-01

    The development of immobilized enzyme and cell technology is summarized. Industrial processes for sucrose inversion, penicillin deacylation and glucose isomerization using immobilized enzymes are described. An alternative process for glucose isomerization using immobilized cells, and some other industrial applications of immobilized cells are indicated. Recent developments in immobilized enzyme and cell technology are assessed and the relative merits of the different biochemical catalyst forms are considered.

  8. Literature search for the non-aqueous separation of zinc from fuel rod cladding. [After dissolution in liquid metal

    SciTech Connect

    Sandvig, R. L.; Dyer, S. J.; Lambert, G. A.; Baldwin, C. E.

    1980-06-21

    This report reviews the literature of processes for the nonaqueous separation of zinc from dissolved fuel assembly cladding. The processes considered were distillation, pyrochemical processing, and electrorefining. The last two techniques were only qualitatively surveyed while the first, distillation, was surveyed in detail. A survey of available literature from 1908 through 1978 on the distillation of zinc was performed. The literature search indicated that a zinc recovery rate in excess of 95% is possible; however, technical problems exist because of the high temperatures required and the corrosive nature of liquid zinc. The report includes a bibliography of the surveyed literature and a computer simulation of vapor pressures in binary systems. 129 references.

  9. Reduction and immobilization of radionuclides and toxic metal ions using combined zero valent iron and anaerobic bacteria. 1998 annual progress report

    SciTech Connect

    Weathers, L.

    1998-06-01

    'Previous research findings indicate that both zero valent iron and sulfate reducing bacteria (SRB) can yield significant decreases in Cr(VI) or U(VI) concentrations due to abiotic and microbial reduction, respectively. The major hypothesis associated with this research project is that a combined abiotic-biological system can synergistically combine both processes to maximize metal ion reduction in an engineered permeable reactive barrier. The overall goal of this project is to design a combined abiotic/microbial, reactive, permeable, in-situ barrier with sufficient reductive potential to prevent downgradient migration of toxic metal ions. The field-scale application of this technology would utilize anaerobic digester sludge, Fe(O) particles for supporting anaerobic biofilms, and suitable aquifer material for construction of the barrier. Successful completion of this goal requires testing of the two hypotheses listed above by evaluating: (1) the rates of abiotic metal ion reduction, and (2) the rates of microbial metal ion reduction in microbial and combined abiotic/microbial reduction systems under a range of environmental conditions. This report summarizes work after one and one-half years of a three year project. Abiotic studies: The thrust of the abiotic research conducted to date has been to determine the rates of Cr(VI) reduction in batch reactors and to evaluate the role of aquifer materials on those rates. Experiments have been conducted to determine the rates of reduction by Fe(II) and Fe(O). The parameters that have been evaluated are the effect of pH and the presence of sulfide and aquifer material.'

  10. Biosensor for metal analysis and speciation

    DOEpatents

    Aiken, Abigail M.; Peyton, Brent M.; Apel, William A.; Petersen, James N.

    2007-01-30

    A biosensor for metal analysis and speciation is disclosed. The biosensor comprises an electron carrier immobilized to a surface of an electrode and a layer of an immobilized enzyme adjacent to the electrode. The immobilized enzyme comprises an enzyme having biological activity inhibited by a metal to be detected by the biosensor.

  11. Expression of cold-adapted β-1,3-xylanase as a fusion protein with a ProS2 tag and purification using immobilized metal affinity chromatography with a high concentration of ArgHCl.

    PubMed

    Kudou, Motonori; Okazaki, Fumiyoshi; Asai-Nakashima, Nanami; Ogino, Chiaki; Kondo, Akihiko

    2015-01-01

    Cold-adapted β-1,3-xylanase (P.t.Xyn26A) from the psychrotrophic bacterium, Psychroflexus torquis, was expressed as a fusion protein with tandem repeats of the N-terminal domain of Protein S from Myxocuccus xanthus (ProS2) in Escherichia coli. After cell lysis in phosphate buffer, most of the ProS2-P.t.Xyn26A was located in the insoluble fraction and aggregated during purification. Arginine hydrochloride (ArgHCl) efficiently solubilized the ProS2-P.t.Xyn26A. The solubilized ProS2-P.t.Xyn26A was purified using immobilized metal affinity chromatography (IMAC) with 500 mM ArgHCl. After cleavage of ProS2-P.t.Xyn26A by human rhinovirus 3C protease, we confirmed that recombinant P.t.Xyn26A maintained its native fold. This is the first report of the expression of a cold-adapted enzyme fused with a ProS2 tag under IMAC purification using a high concentration of ArgHCl. These insights into the expression and purification should be useful during the handling of cold-adapted enzymes. PMID:25214227

  12. Virus-like particles from Escherichia Coli-derived untagged papaya ringspot virus capsid protein purified by immobilized metal affinity chromatography enhance the antibody response against a soluble antigen.

    PubMed

    Guerrero-Rodríguez, Jesús; Manuel-Cabrera, Carlos Alberto; Palomino-Hermosillo, Y Apatzingan; Delgado-Guzmán, Paola Guadalupe; Escoto-Delgadillo, Martha; Silva-Rosales, Laura; Herrera-Rodríguez, Sara Elisa; Sánchez-Hernández, Carla; Gutiérrez-Ortega, Abel

    2014-12-01

    There is a growing interest in using virus-like particles (VLPs) as scaffolds for the presentation of antigens of choice to the immune system. In this work, VLPs from papaya ringspot virus capsid protein expressed in Escherichia coli were evaluated as enhancers of antibody response against a soluble antigen. Interestingly, although the capsid protein lacks a histidine tag, its purification by immobilized metal affinity chromatography was achieved. The formation of VLPs was demonstrated by electron microscopy for the first time for this capsid protein. VLPs were enriched by polyethylene glycol precipitation. Additionally, these VLPs were chemically coupled to green fluorescent protein in order to evaluate them as antigen carriers; however, bioconjugate instability was observed. Nonetheless, the adjuvant effect of these VLPs on BALB/c mice was evaluated, using GFP as antigen, resulting in a significant increase in anti-GFP IgG response, particularly, IgG1 class, demonstrating that the VLPs enhance the immune response against the antigen chosen in this study. PMID:25119647

  13. Grafted-double walled carbon nanotubes as electrochemical platforms for immobilization of antibodies using a metallic-complex chelating polymer: Application to the determination of adiponectin cytokine in serum.

    PubMed

    Ojeda, Irene; Barrejón, Myriam; Arellano, Luis M; González-Cortés, Araceli; Yáñez-Sedeño, Paloma; Langa, Fernando; Pingarrón, José M

    2015-12-15

    An electrochemical immunosensor for adiponectin (APN) using screen printed carbon electrodes (SPCEs) modified with functionalized double-walled carbon nanotubes (DWCNTs) as platforms for immobilization of the specific antibodies is reported. DWCNTs were functionalized by treatment with 4-aminobenzoic acid (HOOC-Phe) in the presence of isoamylnitrite resulting in the formation of 4-carboxyphenyl-DWCNTs. The oriented binding of specific antibodies toward adiponectin was accomplished by using the metallic-complex chelating polymer Mix&Go™. The HOOC-Phe-DWCNTs-modified SPCEs were characterized by cyclic voltammetry and compared with HOOC-Phe-SWCNTs/SPCE. The different variables affecting the performance of the developed immunosensor were optimized. Under the selected conditions, a calibration plot for APN was constructed showing a range of linearity extending between 0.05 and 10.0 μg/mL which is adequate for the determination of the cytokine in real samples. A detection limit of 14.5 ng/mL was achieved. The so prepared immunosensor exhibited a good reproducibility for the APN measurements, excellent storage stability and selectivity, and a much shorter assay time than the available ELISA kits. The usefulness of the immunosensor for the analysis of real samples was demonstrated by analyzing human serum from female or male healthy patients. PMID:26093125

  14. Neutralization of sulfuric acid and immobilization of heavy metals in an acid rock drainage stream, East Mancos River, San Juan National Forest, Colorado

    SciTech Connect

    Meyer, W.A.; Parnell, R.A. Jr.; Bennett, J.B. . Dept. of Geology)

    1993-04-01

    The East Mancos River of Southwestern Colorado is a stream naturally acidified by sulfuric acid produced by outcrops in its stream bed. In the headwaters of the river, two 20m dipslope exposures of fault breccias in the Entrada Sandstone are mineralized by pyrite, chalcopyrite, sphalerite, and galena. Over a 13.4 km distance downstream, solution chemistry rapidly changes and a sequence of inorganic then organic stream coatings are observed. To describe the natural geochemical processes controlling acid anion and heavy metal concentrations in the river, five longitudinal profiles were completed during 1991 and 1992. Complete inorganic chemical analyses of 0.1 [mu]m filtered samples were performed. At each of the 16 water sampling stations, stream discharge was measured, and stream bed grab samples were collected for organic and inorganic characterization by optical petrography, x-ray diffraction, loss on ignition, and selective chemical dissolution. Sulfate, iron, aluminum, copper, zinc and hydrogen ion concentrations decrease steadily downstream. Moving downstream, the amount and composition of ferric oxyhydroxide precipitates decreases rapidly below the breccias. The co-existing iron phases include lepidocroicite, goethite, feroxyhyte, and ferrihydrite. At threshold stream compositions, epilithic coverings of bacteria and algae occur as iron precipitation ceases. Natural neutralization of sulfur acid and loss of heavy metals from solution occurs in excess of that expected by simple dilution of the initial acidic stream water. Abundances and compositions of stream bed precipitates are consistent with the observed losses of ions from the co-existing solution.

  15. Horseradish peroxidase and chitosan: activation, immobilization and comparative results.

    PubMed

    Mohamed, Saleh A; Al-Malki, Abdulrahman L; Kumosani, Taha A; El-Shishtawy, Reda M

    2013-09-01

    Recently, horseradish peroxidase (HRP) was immobilized on activated wool and we envisioned that the use of chitosan would be interesting instead of wool owing to its simple chemical structure, abundant nature and biodegradability. In this work, HRP was immobilized on chitosan crosslinked with cyanuric chloride. FT-IR spectroscopy and scanning electron microscopy were used to characterize immobilized HRP. The number of ten reuses of immobilized HRP has been detected. The pH was shifted from 5.5 for soluble HRP to 5.0 for immobilized enzyme. The soluble HRP had an optimum temperature of 30 °C, which was shifted to 35 °C for immobilized enzyme. The soluble HRP and immobilized HRP were thermal stable up to 35 and 45 °C, respectively. The apparent kinetic constant values (K(m)) of soluble HRP and chitosan-HRP were 35 mM and 40 mM for guaiacol and 2.73 mM and 5.7 mM for H2O2, respectively. Immobilization of HRP partially protected them from metal ions compared to soluble enzyme. The chitosan-HRP was remarkably more stable against urea, Triton X-100 and organic solvents. Chitosan-HRP exhibited large number of reuses and more resistance to harmful compounds compared with wool-HRP. On the basis of results obtained in the present study, chitosan-HRP could be employed in bioremediation application. PMID:23769933

  16. Immobilization of Polyoxometalate in the Metal-Organic Framework rht-MOF-1: Towards a Highly Effective Heterogeneous Catalyst and Dye Scavenger.

    PubMed

    Sun, Jing-Wen; Yan, Peng-Fei; An, Guang-Hui; Sha, Jing-Quan; Li, Guang-Ming; Yang, Guo-Yu

    2016-01-01

    A series of three remarkable complexes [PMo12O40]@[Cu6O(TZI)3(H2O)9]4·OH·31H2O (H3TZI = 5-tetrazolylisophthalic acid; denoted as HLJU-1, HLJU = Heilongjiang University), [SiMo12O40]@[Cu6O(TZI)3(H2O)9]4·32H2O (denoted as HLJU-2), and [PW12O40]@[Cu6O(TZI)3(H2O)6]4·OH·31H2O (denoted as HLJU-3) have been isolated by using simple one-step solvothermal reaction of copper chloride, 5-tetrazolylisophthalic acid (H3TZI), and various Keggin-type polyoxometalates (POMs), respectively. Crystal analysis of HLJU 1-3 reveals that Keggin-type polyoxoanions have been fitted snuggly in the cages of rht-MOF-1 (MOF: metal-organic framework) with large cell volume in a range of 87968-88800 Å(3) and large pore volume of about 68%. HLJU 1-3 exhibit unique catalytic selectivity and reactivity in the oxidation of alkylbenzene with environmental benign oxidant under mild condition in aqueous phase as well as the uptake capacity towards organic pollutants in aqueous solution. PMID:27157290

  17. Metal-organic coordination-enabled layer-by-layer self-assembly to prepare hybrid microcapsules for efficient enzyme immobilization.

    PubMed

    Wang, Xiaoli; Jiang, Zhongyi; Shi, Jiafu; Liang, Yanpeng; Zhang, Chunhong; Wu, Hong

    2012-07-25

    A novel layer-by-layer self-assembly approach enabled by metal-organic coordination was developed to prepare polymer-inorganic hybrid microcapsules. Alginate was first activated via N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS) coupling chemistry, and subsequently reacted with dopamine. Afterward, the dopamine modified alginate (Alg-DA) and titanium(IV) bis(ammonium lactato) dihydroxide (Ti(IV)) were alternatively deposited onto CaCO3 templates. The coordination reaction between the catechol groups of Alg-DA and the Ti(IV) allowed the alternative assembly to form a series of multilayers. After removing the templates, the alginate-titanium hybrid microcapsules were obtained. The high mechanical stability of hybrid microcapsules was demonstrated by osmotic pressure experiment. Furthermore, the hybrid microcapsules displayed superior thermal stability due to Ti(IV) coordination. Catalase (CAT) was used as model enzyme, either encapsulated inside or covalently attached on the surface of the resultant microcapsules. No CAT leakage from the microcapsules was detected after incubation for 48 h. The encapsulated CAT, with a loading capacity of 450-500 mg g(-1) microcapsules, exhibited desirable long-term storage stability, whereas the covalently attached CAT, with a loading capacity of 100-150 mg g(-1) microcapsules, showed desirable operational stability. PMID:22724538

  18. Co-liquefaction of sewage sludge and oil-tea-cake in supercritical methanol: yield of bio-oil, immobilization and risk assessment of heavy metals.

    PubMed

    Zhai, Yunbo; Chen, Zhong; Chen, Hongmei; Xu, Bibo; Li, Ping; Qing, Renpeng; Li, Caiting; Zeng, Guangming

    2015-01-01

    In this study, attention was concentrated on the yields of bio-oil and toxicities of heavy metals (HMs) in liquefaction residues (LRs). Liquefaction of sewage sludge (SS) or oil-tea-cake (OTC) or mixtures of SS and OTC were carried out under the condition of supercritical methanol (SCM). Results showed that the addition of OTC extraordinarily increased the yields of oil from 37.9% (SS) to 86.2% (SS + OTC). Furthermore, with the liquefaction of SS and OTC mixture, the bioavailable fraction (F1 + F2) of Cd and Cu (F1 + F2) was decreased from 2.47 to 1.64 mg/kg and from 98.84 to 67.48 mg/kg, respectively. However, the bioavailable fraction of Zn (F1 + F2) increased from 122.03 to 204.69 mg/kg with the liquefaction of SS. The bioavailable fraction (F1 + F2) of Pb in LRs was 0%, which did not express any changes during the liquefaction process. Risk assessments of geo-accumulation index (I(geo)), risk assessment code (RAC) and modified potential ecological risk index (MRI) were applied to evaluate the bioavailabilities, the potential ecological risks and the pollution levels of HMs. The results show that the OTC in SS can decrease the risk of HMs in LRs. Cd attracted many concerns for the highest risk to the environment among all of the HMs. Here, the good results obtained means that SCM liquefaction of mixture of SS and OTC could be a preferable method for SS treatment. PMID:26027644

  19. Industrial use of immobilized enzymes.

    PubMed

    DiCosimo, Robert; McAuliffe, Joseph; Poulose, Ayrookaran J; Bohlmann, Gregory

    2013-08-01

    Although many methods for enzyme immobilization have been described in patents and publications, relatively few processes employing immobilized enzymes have been successfully commercialized. The cost of most industrial enzymes is often only a minor component in overall process economics, and in these instances, the additional costs associated with enzyme immobilization are often not justified. More commonly the benefit realized from enzyme immobilization relates to the process advantages that an immobilized catalyst offers, for example, enabling continuous production, improved stability and the absence of the biocatalyst in the product stream. The development and attributes of several established and emerging industrial applications for immobilized enzymes, including high-fructose corn syrup production, pectin hydrolysis, debittering of fruit juices, interesterification of food fats and oils, biodiesel production, and carbon dioxide capture are reviewed herein, highlighting factors that define the advantages of enzyme immobilization. PMID:23436023

  20. Bibliography of the technical literature of the Materials Joining Group, Metals and Ceramics Division, 1951 through June 1987

    SciTech Connect

    David, S.A.; Goodwin, G.M.; Gardner, K.

    1987-08-01

    This document contains a listing of the written scientific information originating in the Materials Joining Group (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1987. It is a registry of about 400 documents as nearly as possible in the order in which they were issued.

  1. Giant cell interstitial pneumonia in patients without hard metal exposure: analysis of 3 cases and review of the literature.

    PubMed

    Khoor, Andras; Roden, Anja C; Colby, Thomas V; Roggli, Victor L; Elrefaei, Mohamed; Alvarez, Francisco; Erasmus, David B; Mallea, Jorge M; Murray, David L; Keller, Cesar A

    2016-04-01

    Giant cell interstitial pneumonia is a rare lung disease and is considered pathognomonic for hard metal lung disease, although some cases with no apparent hard metal (tungsten carbide cobalt) exposure have been reported. We aimed to explore the association between giant cell interstitial pneumonia and hard metal exposure. Surgical pathology files from 2001 to 2004 were searched for explanted lungs with the histopathologic diagnosis of giant cell interstitial pneumonia, and we reviewed the associated clinical histories. Mass spectrometry, energy-dispersive x-ray analysis, and human leukocyte antigen typing data were evaluated. Of the 455 lung transplants, 3 met the histologic criteria for giant cell interstitial pneumonia. Patient 1 was a 36-year-old firefighter, patient 2 was a 58-year-old welder, and patient 3 was a 45-year-old environmental inspector. None reported exposure to hard metal or cobalt dust. Patients 1 and 2 received double lung transplants; patient 3 received a left single-lung transplant. Histologically, giant cell interstitial pneumonia presented as chronic interstitial pneumonia with fibrosis, alveolar macrophage accumulation, and multinucleated giant cells of both alveolar macrophage and type 2 cell origin. Energy-dispersive x-ray analysis revealed no cobalt or tungsten particles in samples from the explanted lungs. None of the samples had detectable tungsten levels, and only patient 2 had elevated cobalt levels. The lack of appropriate inhalation history and negative analytical findings in the tissue from 2 of the 3 patients suggests that giant cell interstitial pneumonia is not limited to individuals with hard metal exposure, and other environmental factors may elicit the same histologic reaction. PMID:26997453

  2. CORRELATING METAL SPECIATION IN SOILS

    EPA Science Inventory

    Understanding bioavailability of metals from exposure to contaminated soils is a challenging aspect of environmental research. This presentation will examine three areas of research with respect to metal speciation in soils as it relates to bioavailability: 1) Pb immobilization a...

  3. Adverse reaction to metal bearing leading to femoral stem fractures: a literature review and report of two cases

    PubMed Central

    Al-Azzani, Waheeb A.K.; Iqbal, Hafiz J.; John, Alun

    2016-01-01

    Metal-on-metal (MoM) bearing in total hip replacement (THR) has a high failure rate due to adverse reaction to metal debris (ARMD). There is a spectrum of soft tissue and bony changes in ARMD including muscle necrosis and osteolysis. In our institution, more than 1500 MoM THRs were implanted since 2003. Recently, we have revised significant numbers of these. We report our experience and management of a mode of failure of MoM THR that has been infrequently reported—the distal femoral stem fracture. We report on two patients who presented with worsening pain attributable to fracture of the femoral stem. Severe femoral osteolysis led to loss of proximal stem support and eventual fatigue fracture of the component. Both patients were revised employing a posterior approach. Bone trephine was used to extract a well-fixed distal stem fragment without any windows. Both patients had successful outcome after revision with excellent pain relief and no complications. PMID:26846269

  4. Immobilization of radioactive strontium in contaminated soils by phosphate treatment

    SciTech Connect

    Kim, K.H.; Ammons, J.T. . Dept. of Plant and Soil Science); Lee, S.Y. )

    1990-01-01

    The feasibility of in situ phosphate- and metal- (calcium, aluminum, and iron) solution treatment for {sup 90}Sr immobilization was investigated. Batch and column experiments were performed to find optimum conditions for coprecipitation of {sup 90}Sr with Ca-, Al-, and Fe-phosphate compounds in contaminated soils. Separate columns were packed with artificially {sup 85}Sr-contaminated acid soil as well as {sup 90}Sr-contaminated soil from the Oak Ridge Reservation. After metal-phosphate treatment, the columns were then leached successively with either tapwater or 0.001 M CaCl{sub 2} solution. Most of the {sup 85}Sr coprecipitated with the metal phosphate compounds. Immobilization of {sup 85}Sr and {sup 90}Sr was affected by such factors as solution pH, metal and phosphate concentration, metal-to-phosphate ratio, and soil characteristics. Equilibration time after treatments also affected {sup 85}Sr immobilization. Many technology aspects still need to be investigated before field applications are feasible, but these experiments indicate that phosphate-based in situ immobilization should prevent groundwater contamination and will be useful as a treatment technology for {sup 90}Sr-contaminated sites. 15 refs., 3 figs., 1 tab.

  5. Heavy metal removal and recovery using microorganisms

    SciTech Connect

    Wilde, E.W. ); Benemann, J.R. , Pinole, CA )

    1991-02-01

    Microorganisms -- bacteria, fungi, and microalgae -- can accumulate relatively large amounts of toxic heavy metals and radionuclides from the environment. These organisms often exhibit specificity for particular metals. The metal content of microbial biomass can be a substantial fraction of total dry weight with concentration factors (metal in dry biomass to metal in solution) exceeding one million in some cases. Both living and inert (dead) microbial biomass can be used to reduce heavy metal concentrations in contaminated waters to very low levels -- parts per billion and even lower. In many respects (e.g. specificity, residual metal concentrations, accumulation factors, and economics) microbial bioremoval processes can be superior to conventional processes, such as ion exchange and caustic (lime or hydroxide) precipitation for heavy metals removal from waste and contaminated waters. Thus, bioremoval could be developed to contribute to the clean-up of wastes at the Savannah River Site (SRS) and other DOE facilities. However, the potential advantages of bioremoval processes must still be developed into practical operating systems. A detailed review of the literature suggests that appropriate bioremoval processes could be developed for the SRS. There is great variability from one biomass source to another in bioremoval capabilities. Bioremoval is affected by pH, other ions, temperature, and many other factors. The biological (living vs. dead) and physical (immobilized vs. dispersed) characteristics of the biomass also greatly affect metal binding. Even subtle differences in the microbial biomass, such as the conditions under which it was cultivated, can have major effects on heavy metal binding.

  6. Effects of immobilization on spermiogenesis

    NASA Technical Reports Server (NTRS)

    Meitner, E. R.

    1980-01-01

    The influence of immobilization stress on spermiogenesis in rats was investigated. After 96 hour immobilization, histological changes began to manifest themselves in the form of practically complete disappearance of cell population of the wall of seminiferous tubule as well as a markedly increased number of cells with pathologic mitoses. Enzymological investigations showed various changes of activity (of acid and alkaline phosphatase and nonspecific esterase) in the 24, 48, and 96 hour immobilization groups.

  7. Processes for Removal and Immobilization of 14C, 129I, and 85Kr

    SciTech Connect

    Strachan, Denis M.; Bryan, Samuel A.; Henager, Charles H.; Levitskaia, Tatiana G.; Matyas, Josef; Thallapally, Praveen K.; Scheele, Randall D.; Weber, William J.; Zheng, Feng

    2009-10-05

    This is a white paper covering the results of a literature search and preliminary experiments on materials and methods to remove and immobilize gaseous radionuclided that come from the reprocessing of spent nuclear fuel.

  8. Stabilizing electrodeposition in elastic solid electrolytes containing immobilized anions

    PubMed Central

    Tikekar, Mukul D.; Archer, Lynden A.; Koch, Donald L.

    2016-01-01

    Ion transport–driven instabilities in electrodeposition of metals that lead to morphological instabilities and dendrites are receiving renewed attention because mitigation strategies are needed for improving rechargeability and safety of lithium batteries. The growth rate of these morphological instabilities can be slowed by immobilizing a fraction of anions within the electrolyte to reduce the electric field at the metal electrode. We analyze the role of elastic deformation of the solid electrolyte with immobilized anions and present theory combining the roles of separator elasticity and modified transport to evaluate the factors affecting the stability of planar deposition over a wide range of current densities. We find that stable electrodeposition can be easily achieved even at relatively high current densities in electrolytes/separators with moderate polymer-like mechanical moduli, provided a small fraction of anions are immobilized in the separator. PMID:27453943

  9. Stabilizing electrodeposition in elastic solid electrolytes containing immobilized anions.

    PubMed

    Tikekar, Mukul D; Archer, Lynden A; Koch, Donald L

    2016-07-01

    Ion transport-driven instabilities in electrodeposition of metals that lead to morphological instabilities and dendrites are receiving renewed attention because mitigation strategies are needed for improving rechargeability and safety of lithium batteries. The growth rate of these morphological instabilities can be slowed by immobilizing a fraction of anions within the electrolyte to reduce the electric field at the metal electrode. We analyze the role of elastic deformation of the solid electrolyte with immobilized anions and present theory combining the roles of separator elasticity and modified transport to evaluate the factors affecting the stability of planar deposition over a wide range of current densities. We find that stable electrodeposition can be easily achieved even at relatively high current densities in electrolytes/separators with moderate polymer-like mechanical moduli, provided a small fraction of anions are immobilized in the separator. PMID:27453943

  10. Adsorption of Sr by immobilized microorganisms

    SciTech Connect

    Watson, J.S.; Scott, C.D.; Faison, B.D.

    1988-01-01

    Wastewaters from numerous industrial and laboratory operations can contain toxic or undesirable components such as metal ions, which must be removed before discharge to surface waters. Adsorption processes that have high removal efficiencies are attractive methods for removing such contaminants. For economic operations, it is desirable to have an adsorbent that is selective for the metal contaminant of interest, has high capacity for the contaminant, has rapid adsorption kinetics, can be economically produced, and can be regenerated to a concentrated waste product or decomposed to a low-volume waste. Selected microorganisms are potentially useful adsorbents for these applications because they can be inexpensive, have high selectivities, and have high capacities for adsorption of many heavy metals, which are often problems in a variety of industries. A laboratory-scale packed column containing microbial cells immobilized within a gelatin matrix has been prepared, and its application to removal of Sr from a simulated wastewater is described. 6 refs., 2 figs., 3 tabs.