Sample records for carbonate wash solutions

  1. Solvent wash solution

    DOEpatents

    Neace, J.C.

    1984-03-13

    A process is claimed for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 vol % of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

  2. Solvent wash solution

    DOEpatents

    Neace, James C. (Blackville, SC)

    1986-01-01

    Process for removing diluent degradation products from a solvent extraction solution, which has been used to recover uranium and plutonium from spent nuclear fuel. A wash solution and the solvent extraction solution are combined. The wash solution contains (a) water and (b) up to about, and including, 50 volume percent of at least one-polar water-miscible organic solvent based on the total volume of the water and the highly-polar organic solvent. The wash solution also preferably contains at least one inorganic salt. The diluent degradation products dissolve in the highly-polar organic solvent and the organic solvent extraction solvent do not dissolve in the highly-polar organic solvent. The highly-polar organic solvent and the extraction solvent are separated.

  3. Potential of activated carbon to recover randomly-methylated-?-cyclodextrin solution from washing water originating from in situ soil flushing.

    PubMed

    Sniegowski, K; Vanhecke, M; D'Huys, P-J; Braeken, L

    2014-07-01

    Despite the overall high efficacy of cyclodextrins to accelerate the treatment of soil aquifer remediation by in-situ soil flushing, the use in practice remains limited because of the high costs of cyclodextrin and high concentrations needed to significantly reduce the treatment time. The current study tested the potential of activated carbon to treat washing water originating from soil flushing in order to selectively separate hydrocarbon contaminants from washing water containing cyclodextrin and subsequently reuse the cyclodextrin solution for reinfiltration. A high recovery of the cyclodextrin from the washing water would reduce the costs and would make the technique economically feasible for soil remediation. This study aimed to investigate whether cyclodextrin can pass through the activated carbon filter without reducing the cyclodextrin concentration when the contaminated washing water is treated and whether the presence of cyclodextrin negatively affects the purification potential of activated carbon to remove the organic pollutants from the pumped soil water. Lab-scale column experiments showed that with the appropriate activated carbon 100% of cyclodextrin (randomly-methylated-?-cyclodextrin) can be recovered from the washing water and that the effect on the efficiency of activated carbon to remove the hydrocarbon contaminants remains limited. These results show that additional field tests are useful to make in-situ soil flushing with cyclodextrin both a technical and an economical interesting technique. These results might stimulate the application of cyclodextrin in soil treatment technology. PMID:24325845

  4. Soil washing of fluorine contaminated soil using various washing solutions.

    PubMed

    Moon, Deok Hyun; Jo, Raehyun; Koutsospyros, Agamemnon; Cheong, Kyung Hoon; Park, Jeong-Hun

    2015-03-01

    Bench-scale soil washing experiments were conducted to remove fluoride from contaminated soils. Five washing solutions including hydrochloric acid (HCl), nitric acid (HNO3), sodium hydroxide (NaOH), sulfuric acid (H2SO4) and tartaric acid (C4H6O6) were tested. The concentration of the washing solutions used ranged from 0.1 to 3 M with a liquid to solid ratio of 10. The soil washing results showed that the most effective washing solution for the removal of fluoride from contaminated soils was HCl. The highest fluoride removal results of approximately 97 % from the contaminated soil were obtained using 3 M HCl. The fluoride removal efficiency of the washing solution increases in the following order: C4H6O6 < NaOH < H2SO4 < HNO3 < HCl. PMID:25552323

  5. 7 CFR 2902.51 - Parts wash solutions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Parts wash solutions. 2902.51 Section 2902... Designated Items § 2902.51 Parts wash solutions. (a) Definition. ...preference for qualifying biobased parts wash solutions. By that date, Federal...

  6. Washing of soils spiked with various pollutants by surfactant solutions

    SciTech Connect

    Yang, G.C.C.; Chang, J.H. [National Sun Yat-Sen Univ., Kaohsiung (Taiwan, Province of China)

    1995-12-31

    In this study, the batch-type of washing with surfactant solutions was employed for the treatment of soils artificially contaminated with various volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals. 15 industrial grade surfactants were tested. Washing was conducing by adding surfactant solution to the soils and mixing for one hour, then centrifuging it and analyzing the supernatant. Deionized water was used for soil washing for comparison. Results indicated that deionized water performed as well as Surfactant No. 1 in washing VOC-contaminated soils. Therefore, it is concluded that the VOCs tested can be easily washed from soils by rain water. In washing PAH-contaminated soils, nonionic surfactants performed better than anionic surfactants in terms of removal efficiency. The amphoteric surfactant performed worst in washing PAH-contaminated soils. Generally, surfactants are useful in removing cadmium from soils, but are not useful for the removal of lead and copper. Amphoteric, anionic, and low pH cationic surfactants were the most effective of those tested. For PAH/heavy metals-contaminated soils, removal efficiencies were lower than that of soils containing a single contaminant.

  7. Fresh produce washing aid, T-128, enhances inactivation of salmonella and pseudomonas biofilms on stainless steel in chlorinated wash solutions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of chlorine wash solutions, with/without the washing aid, T-128, on inactivation of Salmonella and Pseudomonas populations in biofilms on stainless steel coupons was evaluated under conditions of increasing organic matter loads in the wash water. Biofilms were formed statically on stai...

  8. Aquifer washing by micellar solutions: 2. DNAPL recovery mechanisms for an optimized alcohol surfactant solvent solution

    NASA Astrophysics Data System (ADS)

    Martel, Richard; Lefebvre, René; Gélinas, Pierre J.

    1998-03-01

    A large sand column experiment is used to illustrate the principles of complex organic contaminants (DNAPL) recovery by a chemical solution containing an alcohol ( n-butanol), a surfactant (Hostapur SAS), and two solvents ( d-limonene and toluene). The washing solution is pushed by viscous polymer solutions to keep the displacement stable. The main NAPL recovery mechanisms identified are: (1) immiscible displacement by oil saturation increase (oil swelling), oil viscosity reduction, interfacial tension lowering, and relative permeability increase; (2) miscible NAPL displacement by solubilization. Most of the NAPL was recovered in a Winsor, type II system ahead of the washing solution. The 0.8 pore volume (PV) of alcohol-surfactant-solvent solution injected recovered more than 89% of the initial residual DNAPL saturation (0.195). Winsor system types were determined by visual observation of phases and confirmed by electrical resistivity measurements of phases and water content measurements in the oleic phase. Viscosity and density lowering of the oleic phase was made using solvents and alcohol transfer from the washing solution. Small sand column tests are performed to check different rinsing strategies used to minimize washing solution residual ingredients which can be trapped in sediments. An alcohol/surfactant rinsing solution without solvent, injected behind the washing solution, minimizes solvent trapping in sediments. More than five pore volumes of polymer solution and water must be injected after the rinsing solution to decrease alcohol and SAS concentrations in sediments to an acceptable level. To obtain reasonable trapped surfactant concentrations in sediments, the displacement front between the rinsing solution and the subsequent the following polymer solution has to be stable.

  9. Aquifer washing by micellar solutions: 1. Optimization of alcohol-surfactant-solvent solutions

    NASA Astrophysics Data System (ADS)

    Martel, Richard; Gélinas, Pierre J.; Desnoyers, Jacques E.

    1998-03-01

    Phase diagrams were used for the formulation of alcohol-surfactant-solvent and to identify the DNAPL (Dense Non Aqueous Phase Liquid) extraction zones. Four potential extraction zones of Mercier DNAPL, a mixture of heavy aliphatics, aromatics and chlorinated hydrocarbons, were identified but only one microemulsion zone showed satisfactory DNAPL recovery in sand columns. More than 90 sand column experiments were performed and demonstrate that: (1) neither surfactant in water, alcohol-surfactant solutions, nor pure solvent can effectively recover Mercier DNAPL and that only alcohol-surfactant-solvent solutions are efficient; (2) adding salts to alcohol-surfactant or to alcohol-surfactant-solvent solutions does not have a beneficial effect on DNAPL recovery; (3) washing solution formulations are site specific and must be modified if the surface properties of the solids (mineralogy) change locally, or if the interfacial behavior of liquids (type of oil) changes; (4) high solvent concentrations in washing solutions increase DNAPL extraction but also increase their cost and decrease their density dramatically; (5) maximum DNAPL recovery is observed with alcohol-surfactant-solvent formulations which correspond to the maximum solubilization in Zone C of the phase diagram; (6) replacing part of surfactant SAS by the alcohol n-butanol increases washing solution efficiency and decreases the density and the cost of solutions; (7) replacing part of n-butanol by the nonionic surfactant HOES decreases DNAPL recovery and increases the cost of solutions; (8) toluene is a better solvent than D-limonene because it increases DNAPL recovery and decreases the cost of solutions; (9) optimal alcohol-surfactant-solvent solutions contain a mixture of solvents in a mass ratio of toluene to D-limonene of one or two. Injection of 1.5 pore volumes of the optimal washing solution of n-butanol-SAS-toluene- D-limonene in water can recover up to 95% of Mercier DNAPL in sand columns. In the first pore volume of the washing solution recovered in the sand column effluent, the DNAPL is in a water-in-oil microemulsion lighter than the excess aqueous phase (Winsor Type II system), which indicates that part of the DNAPL was mobilized. In the next pore volumes, DNAPL is dissolved in a oil-in-water microemulsion phase and is mobilized in an excess oil phase lighter than the microemulsion (Winsor Type I system). The main drawback of this oil extraction process is the high concentration of ingredients necessary for DNAPL dissolution, which makes the process expensive. Because mobilization of oil seems to occur at the washing solution front, an injection strategy must be developed if there is no impermeable limit at the aquifer base. DNAPL recovery in the field could be less than observed in sand columns because of a smaller sweep efficiency related to field sand heterogeneities. The role of each component in the extraction processes in sand column as well as the Winsor system type have to be better defined for modeling purposes. Injection strategies must be developed to recover ingredients of the washing solution that can remain in the soil at the end of the washing process.

  10. Effect of Nitric Acid “Washing” Procedure on Electrochemical Behavior of Carbon Nanotubes and Glassy Carbon ?-Particles

    PubMed Central

    2010-01-01

    The electroanalytic performances of glassy carbon paste electrode (GCPE), multi-walled carbon nanotube (MWCNT)-GCPE and double-walled carbon nanotube (DWCNT)-GCPE, which include HNO3 washed/unwashed materials, were compared by monitoring cyclic voltammograms of potassium ferricyanide and catechol. Electrodes were prepared by introducing proper amount of DWCNT and MWCNT into GCPE. First untreated materials (DWCNT, MWCNT, GC ?-particles) were used in the electrodes and then HNO3-treated materials were utilized for comparing difference in electrochemical performances. The effect of treatment procedure was also examined by applying Raman spectroscopy to treated and untreated materials. Moreover, TEM images were obtained for further investigation of MWCNT and DWCNT. PMID:20672081

  11. Aquifer washing by micellar solutions: 2. DNAPL recovery mechanisms for an optimized alcohol–surfactant–solvent solution

    Microsoft Academic Search

    Richard Martel; René Lefebvre; Pierre J Gélinas

    1998-01-01

    A large sand column experiment is used to illustrate the principles of complex organic contaminants (DNAPL) recovery by a chemical solution containing an alcohol (n-butanol), a surfactant (Hostapur SAS), and two solvents (d-limonene and toluene). The washing solution is pushed by viscous polymer solutions to keep the displacement stable. The main NAPL recovery mechanisms identified are: (1) immiscible displacement by

  12. Electrochemical treatment of spent solution after EDTA-based soil washing.

    PubMed

    Voglar, David; Lestan, Domen

    2012-04-15

    The use of EDTA in soil washing technologies to remediate soils contaminated with toxic metals is prohibitive because of the large volumes of waste washing solution generated, which must be treated before disposal. Degradation of EDTA in the waste solution and the removal of Pb, Zn and Cd were investigated using electrochemical advanced oxidation processes (EAOP) with a boron-doped diamond anode (BDDA), graphite and iron anodes and a stainless-steel cathode. In addition to EAOP, the efficiency of electro-Fenton reactions, induced by the addition of H(2)O(2) and the regulation of electrochemical systems to pH 3, was also investigated. Soil extraction with 15 mmol kg(-1) of soil EDTA yielded waste washing solution with 566 ± 1, 152 ± 1 and 5.5 ± 0.1 mg L(-1) of Pb, Zn and Cd, respectively. Treatments of the waste solution in pH unregulated electrochemical systems with a BDDA and graphite anode (current density 67 mA cm(-2)) were the most efficient and removed up to 98 ± 1, 96 ± 1, 99 ± 1% of Pb, Zn and Cd, respectively, by electrodeposition on the cathode and oxidatively degraded up to 99 ± 1% of chelant. In the electrochemical system with an Fe anode operated at pH 3, the chelant remained preserved in the treated solution, while metals were removed by electrodeposition. This separation opens up the possibility of a new EDTA recycling method from waste soil washing solution. PMID:22305659

  13. Removal of perfluorinated carboxylates from washing wastewater of perfluorooctanesulfonyl fluoride using activated carbons and resins.

    PubMed

    Du, Ziwen; Deng, Shubo; Chen, Youguang; Wang, Bin; Huang, Jun; Wang, Yujue; Yu, Gang

    2015-04-01

    Perfluorooctanesulfonyl fluoride (PFOSF) washing wastewater contains high concentrations of perfluorinated carboxylates (PFCAs) including perfluorohexanoate (PFHxA, 0.10mmol/L), perfluoroheptanoate (PFHpA, 0.11mmol/L), and perfluorooctanoate (PFOA, 0.29mmol/L). For the first time, we investigated the removal of these PFCAs from actual wastewater using the bamboo-derived activated carbon (BAC) and resin IRA67. Adsorption kinetics, effects of adsorbent dose, solution pH, and inorganic ions, as well as regeneration and reuse experiments were studied. The removal percents of three PFCAs by BAC and IRA67 followed the increasing order of PFHxAsolution, due to the presence of high concentration of inorganic ions in the wastewater. However, the co-existing organic compounds in wastewater significantly suppressed the adsorption of PFCAs. Both spent BAC and IRA67 were successfully regenerated by ethanol solution or NaCl/methanol mixture, and IRA67 showed the stable removal of PFCAs in five adsorption cycles. PMID:25585266

  14. Wash Solution Bath Life Extension for the Space Shuttle Rocket Motor Aqueous Cleaning System

    NASA Technical Reports Server (NTRS)

    Saunders, Chad; Evans, Kurt; Sagers, Neil

    1999-01-01

    A spray-in-air aqueous cleaning system, which replaced 1,1,1 trichloroethane (TCA) vapor degreasing, is used for critical cleaning of Space Shuttle Redesigned Solid Rocket Motor (RSRM) metal parts. Small-scale testing demonstrated that the alkaline-based wash solution possesses adequate soil loading and cleaning properties. However, full-scale testing exhibited unexpected depletion of some primary components of the wash solution. Specifically, there was a significant decrease in the concentration of sodium metasilicate which forced change-out of the wash solution after eight days. Extension of wash solution bath life was necessary to ease the burden of frequent change-out on manufacturing. A laboratory study supports a depletion mechanism that is initiated by the hydrolysis of sodium tripolyphosphate (STPP) lowering the pH of the solution. The decrease in pH causes polymerization and subsequent precipitation of sodium metasilicate (SM). Further investigation showed that maintaining the pH was the key to preventing the precipitation of the sodium metasilicate. Implementation to the full scale operation demonstrated that periodic additions of potassium hydroxide (KOH) extended the useful bath life to more than four months.

  15. Modified sodium diuranate process for the recovery of uranium from uranium hexafluoride transport cylinder wash solution

    NASA Astrophysics Data System (ADS)

    Meredith, Austin Dean

    Uranium hexafluoride (UF6) containment cylinders must be emptied and washed every five years in order to undergo recertification, according to ANSI standards. During the emptying of the UF6 from the cylinders, a thin residue, or heel, of UF6 is left behind. This heel must be removed in order for recertification to take place. To remove it, the inside of the containment cylinder is washed with acid and the resulting solution generally contains three or four kilograms of uranium. Thus, before the liquid solution can be disposed of, the uranium must be separated. A modified sodium diuranate (SDU) uranium recovery process was studied to support development of a commercial process. This process was sought to ensure complete uranium recovery, at high purity, in order that it might be reused in the nuclear fuel cycle. An experimental procedure was designed and carried out in order to verify the effectiveness of the commercial process in a laboratory setting. The experiments involved a small quantity of dried UO2F2 powder that was dosed with 3wt% FeF3 and was dissolved in water to simulate the cylinder wash solution. Each experiment series started with a measured amount of this powder mixture which was dissolved in enough water to make a solution containing about 120 gmU/liter. The experiments involved validating the modified SDU extraction process. A potassium diuranate (KDU) process was also attempted. Very little information exists regarding such a process, so the task was undertaken to evaluate its efficacy and determine whether a potassium process yields any significant differences or advantages as compared to a sodium process. However, the KDU process ultimately proved ineffective and was abandoned. Each of the experiments was organized into a series of procedures that started with the UO2F2 powder being dissolved in water, and proceeded through the steps needed to first convert the uranium to a diuranate precipitate, then to a carbonate complex solution, and finally to a uranyl peroxide (UO4) precipitate product. Evaluation of operating technique, uranium recovery efficiency, and final product purity were part of each experiment. Evaluation of a technique for removing fluoride from the diuranate precipitation byproduct filtrate using granular calcite was also included at the end of the uranium recovery testing. It was observed that precipitation of sodium diuranate (SDU) was very nearly complete at a pH of 11-12, using room temperature conditions. Uranium residuals in the filtrate ranged from 3.6 - 19.6 ppm, meaning almost complete precipitation as SDU. It was postulated and then verified that a tailing reaction occurs in the SDU precipitation, which necessitates a digestion period of about 2 hours to complete the precipitation. Further, it was shown, during this phase of the process, that a partial precipitation step at pH 5.5 did not adequately separate iron contamination due to an overlap of uranium and iron precipitations at that condition. Carbonate extraction of the SDU required an extended (3-4 hours) digestion at 40°C and pH 7-8 to complete, with sodium bicarbonate found to be the preferred extractant. The carbonate extraction was also proven to successfully separate the iron contamination from the uranium. Potassium-based chemistry did produce a potassium diuranate (KDU) analogue of SDU, but the subsequent carbonate extraction using either potassium bicarbonate or potassium carbonate proved to be too difficult and was incomplete. The potassium testing was terminated at this step. The uranyl peroxide precipitation was found to operate best at pH 3.5 - 4.0, at room temperature, and required an expected, extended digestion period of 8 -10 hours. The reaction was nearly complete at those conditions, with a filtrate residual ranging from 2.4 to 36.8 ppmU. The uranyl peroxide itself was very pure, with impurity averages at a very low 0.8 ppmNa and 0.004 ppmFe. ASTM maximum levels are 20 ppmNa and 150 ppmFe. Fluoride removal from the SDU precipitation filtrate required multiple passes of the solution through a calcite

  16. Surgical scrubbing: can we clean up our carbon footprints by washing our hands?

    PubMed

    Somner, J E A; Stone, N; Koukkoulli, A; Scott, K M; Field, A R; Zygmunt, J

    2008-11-01

    A growing scientific consensus states that the global climate is changing and that human activity is responsible for these changes. It folLows that each of us has a responsibility to look at how our own lives impact on the environment. This study aimed to investigate water use during surgical scrubbing. Two water delivery systems were assessed to see whether technological innovation can promote more 'environmentally friendly' scrubbing behaviour. At least 10 different individuals, comprising surgeons, assistants and scrub nurses, were observed at two sites. Twenty-five separate surgical scrubs were observed in each location and the length of time for which the tap was on recorded. The tap was on during surgical scrubbing for a mean of 2 min 23 s at Gartnavel General Hospital (maximum: 4 min 37 s; minimum: 49 s; SD: 55 s) and for a mean of 1 min 7 s at Stobhill Hospital (maximum: 2 min 25 s; minimum: 19 s; SD: 33 s). The mean 'tap on' time (in seconds) at Gartnavel was significantly greater than that at Stobhill [t(39.5)=P<0.001]. A different tap design resulted in a net saving of 5.7 L of hot water, approximately 600 kJ of energy and 80 g of carbon dioxide emitted per surgical scrub. Surgical scrubbing is a ubiquitous procedure performed daily in healthcare settings. A simple technological solution can reduce water and energy use by modifying hand-washing behaviour and thereby reduce the carbon footprint of surgical scrubbing. PMID:18701193

  17. Changes in the bacterial flora of skin of processed broiler chickens washed in solutions of salicylic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in the number of bacteria recovered from the skin of processed broilers after each of five consecutive washings in salicylic acid (SA) solutions was examined. Skin samples from commercially processed broiler carcasses were divided into 3 groups and washed in distilled water (control), 10% S...

  18. Enhanced Inactivation of Salmonella and Pseudomonas Biofilms on Stainless Steel by Use of T-128, a Fresh-Produce Washing Aid, in Chlorinated Wash Solutions

    PubMed Central

    Shen, Cangliang; Luo, Yaguang; Nou, Xiangwu; Bauchan, Gary; Zhou, Bin; Wang, Qin

    2012-01-01

    The effect of the washing aid T-128 (generally recognized as safe [GRAS] formulation, composed mainly of phosphoric acid and propylene glycol) on inactivation of Salmonella and Pseudomonas populations in biofilms on stainless steel was evaluated under conditions of increasing organic matter loads in chlorinated wash solutions dominated by hypochlorous acid. Biofilms were formed statically on stainless steel coupons suspended in 2% lettuce extract after inoculation with Salmonella enterica serovar Thompson or Newport or with Pseudomonas fluorescens. Coupons with biofilms were washed in chlorine solutions (0, 0.5, 1, 2, 5, 10, or 20 mg/liter at pH 6.5, 5.0 and 2.9), with or without T-128, and with increasing loads of organic matter (0, 0.25, 0.5, 0.75, or 1.0% lettuce extract). Cell populations on coupons were dispersed using intermittent, pulsed ultrasonication and vortexing and enumerated by colony counts on XLT-4 or Pseudomonas agars. Cell responses to fluorescent viability staining of biofilm treatment washing solutions were examined using confocal laser scanning microscopy. Results showed that 0.1% T-128 (without chlorine) reduced P. fluorescens biofilm populations by 2.5 log10 units but did not reduce Salmonella populations. For both Salmonella and Pseudomonas, the sanitizing effect of free chlorine (1.0 to 5.0 mg/liter) was enhanced (P < 0.05) when it was combined with T-128. Application of T-128 decreased the free chlorine depletion rate caused by increasing organic matter in wash waters and significantly (P < 0.05) augmented inactivation of bacteria in biofilms compared to treatments without T-128. Image analysis of surfaces stained with SYTO and propidium iodide corroborate the cultural assay results showing that T-128 can aid in reducing pathogen viability in biofilms and thus can aid in sanitizing stainless steel contact surfaces during processing of fresh-cut produce. PMID:22752180

  19. Effect of number and washing solutions on functional properties of surimi-like material from duck meat.

    PubMed

    Ramadhan, Kurnia; Huda, Nurul; Ahmad, Ruzita

    2014-02-01

    Duck meat is less utilized than other meats in processed products because of limitations of its functional properties, including lower water holding capacity, emulsion stability, and higher cooking loss compared with chicken meat. These limitations could be improved using surimi technology, which consists of washing and concentrating myofibrillar protein. In this study, surimi-like materials were made from duck meat using two or three washings with different solutions (tap water, sodium chloride, sodium bicarbonate, and sodium phosphate buffer). Better improvement of the meat's functional properties was obtained with three washings versus two washings. Washing with tap water achieved the highest gel strength; moderate elevation of water holding capacity, pH, lightness, and whiteness; and left a small amount of fat. Washing with sodium bicarbonate solution generated the highest water holding capacity and pH and high lightness and whiteness values, but it resulted in the lowest gel strength. Processing duck meat into surimi-like material improves its functional properties, thereby making it possible to use duck meat in processed products. PMID:24493882

  20. Formulating essential oil microemulsions as washing solutions for organic fresh produce production.

    PubMed

    Zhang, Linhan; Critzer, Faith; Davidson, P Michael; Zhong, Qixin

    2014-12-15

    Applications of plant-derived organic essential oils (EOs) as antimicrobials for post-harvest produce operations are limited by their low water solubility. To dissolve EOs in water, microemulsions were studied using two surfactants permitted for organic production, sucrose octanoate ester (SOE) and soy lecithin that were mixed at various mass ratios before dilution with water to 40% w/w. EOs were then mixed with the surfactant solution by hand shaking. Based on visual transparency, intermediate lecithin:SOE mass ratios favoured the formation of microemulsions, e.g., up to 4.0% clove bud oil at ratios of 2:8 and 3:7, and 4.0% cinnamon bark oil and 3.0% thyme oil at ratios of 2:8 and 1:9, respectively. Microemulsions with intermediate lecithin:SOE mass ratios had a relatively low viscosity and better ability to wet fresh produce surfaces. The microemulsions established in this work may be used as washing solutions to enhance the microbial safety of organic fresh produce. PMID:25038656

  1. Effects of Washing Produce Contaminated with the Snail and Slug Hosts of Angiostrongylus cantonensis with Three Common Household Solutions

    PubMed Central

    Yeung, Norine W; Hayes, Kenneth A

    2013-01-01

    The emerging infectious disease angiostrongyliasis (rat lungworm disease) is caused by ingesting snails and slugs infected by the nematode Angiostrongylus cantonensis. The definitive hosts of A. cantonensis are rats and the obligatory intermediate hosts are slugs and snails. Many cases result from accidentally ingesting infected snails or slugs on produce (eg, lettuce). This study assessed three readily available household products as washing solutions for removing snails and slugs from produce (romaine lettuce) to lower the probability of accidentally ingesting them. The solutions were acetic acid (vinegar), sodium hypochlorite (bleach), and sodium chloride (domestic salt). Snail and slug species known to be intermediate hosts and that are common in the Hawaiian Islands were used in the experiments: the alien snail Succinea tenella, the alien semi-slug Parmarion martensi, and the alien slugs Veronicella cubensis and Deroceras laeve. None of the products was any more effective than washing and rinsing with tap water alone. Most snails and slugs were removed after treatment but some remained on the lettuce even after washing and rinsing the produce. Only washing, rinsing, and then rinsing each leaf individually resulted in complete removal of all snails and slugs. The study did not address removal of any remaining slime left by the snails and slugs, nor did it address killing of worms. PMID:23901391

  2. Effects of washing produce contaminated with the snail and slug hosts of Angiostrongylus cantonensis with three common household solutions.

    PubMed

    Yeung, Norine W; Hayes, Kenneth A; Cowie, Robert H

    2013-06-01

    The emerging infectious disease angiostrongyliasis (rat lungworm disease) is caused by ingesting snails and slugs infected by the nematode Angiostrongylus cantonensis. The definitive hosts of A. cantonensis are rats and the obligatory intermediate hosts are slugs and snails. Many cases result from accidentally ingesting infected snails or slugs on produce (eg, lettuce). This study assessed three readily available household products as washing solutions for removing snails and slugs from produce (romaine lettuce) to lower the probability of accidentally ingesting them. The solutions were acetic acid (vinegar), sodium hypochlorite (bleach), and sodium chloride (domestic salt). Snail and slug species known to be intermediate hosts and that are common in the Hawaiian Islands were used in the experiments: the alien snail Succinea tenella, the alien semi-slug Parmarion martensi, and the alien slugs Veronicella cubensis and Deroceras laeve. None of the products was any more effective than washing and rinsing with tap water alone. Most snails and slugs were removed after treatment but some remained on the lettuce even after washing and rinsing the produce. Only washing, rinsing, and then rinsing each leaf individually resulted in complete removal of all snails and slugs. The study did not address removal of any remaining slime left by the snails and slugs, nor did it address killing of worms. PMID:23901391

  3. Impact of Extraperitoneal Dioxyde Carbon Insufflation on Respiratory Function in Anesthetized Adults: A Preliminary Study Using Electrical Impedance Tomography and Wash-out/Wash-in Technic

    PubMed Central

    Bordes, Julien; Mazzeo, Cecilia; Gourtobe, Philippe; Cungi, Pierre Julien; Antonini, Francois; Bourgoin, Stephane; Kaiser, Eric

    2015-01-01

    Background: Extraperitoneal laparoscopy has become a common technique for many surgical procedures, especially for inguinal hernia surgery. Investigations of physiological changes occurring during extraperitoneal carbon dioxide (CO2) insufflation mostly focused on blood gas changes. To date, the impact of extraperitoneal CO2 insufflation on respiratory mechanics remains unknown, whereas changes in respiratory mechanics have been extensively studied in intraperitoneal insufflation. Objectives: The aim of this study was to investigate the effects of extraperitoneal CO2 insufflation on respiratory mechanics. Patients and Methods: A prospective and observational study was performed on nine patients undergoing laparoscopic inguinal hernia repair. Anesthetic management and intraoperative care were standardized. All patients were mechanically ventilated with a tidal volume of 8 mL/kg using an Engström Carestation ventilator (GE Healthcare). Ventilation distribution was assessed by electrical impedance tomography (EIT). End-expiratory lung volume (EELV) was measured by a nitrogen wash-out/wash-in method. Ventilation distribution, EELV, ventilator pressures and hemodynamic parameters were assessed before extraperitoneal insufflation, and during insufflation with a PEEP of 0 cmH2O, 5 cmH20 and of 10 cmH20. Results: EELV and thoracopulmonary compliance were significantly decreased after extraperitoneal insufflation. Ventilation distribution was significantly higher in ventral lung regions during general anesthesia and was not modified after insufflation. A 10 cmH20 PEEP application resulted in a significant increase in EELV, and a shift of ventilation toward the dorsal lung regions. Conclusions: Extraperitoneal insufflation decreased EELV and thoracopulmonary compliance. Application of a 10 cmH20 PEEP increased EELV and homogenized ventilation distribution. This preliminary clinical study showed that extraperitoneal insufflation worsened respiratory mechanics, which may justify further investigations to evaluate the clinical impact.

  4. Spray washing carcasses with alkaline solutions of lauric acid to reduce bacterial contamination.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of spray washing carcasses with lauric acid (LA)-potassium hydroxide (KOH) on bacteria recovered from whole-carcass-rinsates (WCR) was examined. Skin of carcasses was inoculated with a cecal paste containing antibiotic resistant strains of Escherichia coli, Salmonella Typhimirum, and Camp...

  5. Residual behaviour of profenofos on some field-grown vegetables and its removal using various washing solutions and household processing.

    PubMed

    Radwan, M A; Abu-Elamayem, M M; Shiboob, M H; Abdel-Aal, A

    2005-04-01

    Profenofos (Selecron 72% EC), was sprayed on field-grown pepper and eggplant at the recommended rate of 1.28 kg a,i/ha. Fruit samples were collected at 1 h to 14 days after application and analysed to determine the content and dissipation rate of profenofos. The effect of different washing solutions and some household processing on the removal of such residues from treated vegetables were also investigated. Profenofos residues were quantified by using gas chromatography. The results showed that the consumable safety time were found to be 10 days on sweet pepper and 14 days on hot pepper and eggplant fruits. The initial disappearance of profenofos appeared to follow first order kinetics with different rates of reaction of 0.38, 0.40 and 0.35 day(-1) for hot pepper, sweet pepper and eggplant, respectively. The corresponding half-lives (t1/2) were 1.84, 1.74 and 1.96 days. Also, the results indicated that tap water, potassium permenganate and acetic acid solution gave high percent removal of profenofos residues from hot and sweet pepper fruits, while no detectable residues was found in eggplant fruit after washing with soap and acetic acid solutions. In general, all tested washing solutions gave higher percent removal of profenofos residues from eggplant fruit than the two other pepper fruits. Blanching and frying of pepper and eggplant fruits resulted in great reduction to almost completely removed (approximately 100%) of the deposited profenofos. In addition, pickling process removed 92.58 and 95.61% from hot pepper fruit after one week and after two weeks, respectively. PMID:15721202

  6. Fresh produce washing aid, T-128, enhances inactivation of Salmonella and pseudomonas biofilms on stainless steel coupons in chlorinated wash solutions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Bacterial biofilms on food processing equipment can protect pathogens against sanitizers. When chlorine is rapidly depleted by organic materials present in process wash water, inactivation of biofilm pathogens is further challenging. Purpose: This study was conducted to evaluate the e...

  7. SOIL WASHING TREATMENT

    EPA Science Inventory

    Soil washing is a water-based process for mechanically scrubbing soils ex-situ to remove undesirable contaminants. he process removes contaminants from soils in one of two ways: by dissolving or suspending them in the wash solution (which is later treated by conventional wastewat...

  8. The Asia Oceania Human Proteome Organisation Membrane Proteomics Initiative. Preparation and characterization of the carbonate-washed membrane standard

    PubMed Central

    Peng, Lifeng; Kapp, Eugene A.; Fenyö, David; Kwon, Min-Seok; Jiang, Pu; Wu, Songfeng; Jiang, Ying; Aguilar, Marie-Isabel; Ahmed, Nikhat; Baker, Mark S.; Cai, Zongwei; Chen, Yu-Ju; Van Chi, Phan; Chung, Maxey C. M.; He, Fuchu; Len, Alice C. L.; Liao, Pao-Chi; Nakamura, Kazuyuki; Ngai, Sai Ming; Paik, Young-Ki; Pan, Tai-Long; Poon, Terence C. W.; Salekdeh, Ghasem Hosseini; Simpson, Richard J.; Sirdeshmukh, Ravi; Srisomsap, Chantragan; Svasti, Jisnuson; Tyan, Yu-Chang; Dreyer, Florian S.; McLauchlan, Danyl; Rawson, Pisana; Jordan, T. William

    2013-01-01

    The Asia Oceania Human Proteome Organisation has embarked on a Membrane Proteomics Initiative with goals of systematic comparison of strategies for analysis of membrane proteomes and discovery of membrane proteins. This multi-laboratory project is based on analysis of a subcellular fraction from mouse liver that contains endoplasmic reticulum and other organelles. Here we present the strategy used for preparation and initial characterisation of the membrane sample, including validation that the carbonate-washing step enriches for integral and lipid-anchored membrane proteins. Analysis of seventeen independent datasets from five types of proteomic workflows is in progress. PMID:20486120

  9. Kinetics of dodecanoic acid adsorption from caustic solution by activated carbon

    Microsoft Academic Search

    Phillip Pendleton; Sophie Hua Wu

    2003-01-01

    This study examines the influences of adsorbent porosity and surface chemistry and of carbon dosage on dodecanoic acid adsorption kinetics from aqueous and 2 M NaOH solutions as batch adsorption processes. Both adsorbents are steam-activated carbons prepared from either coconut or coal precursors. Prior to use the adsorbents were washed in deionized water or 2 M NaOH. Mass transfer coefficients and effective

  10. No washing, less waiting: engineering biomolecular reporters for single-step antibody detection in solution.

    PubMed

    Banala, Sambashiva; Arts, Remco; Aper, Stijn J A; Merkx, Maarten

    2013-11-28

    Detection of antibodies is essential for the diagnosis of many disease states, including infectious diseases, autoimmune diseases and allergies. Most current antibody detection assays involve multistep detection schemes in which molecular recognition and signal generation are separate processes. A well-known example is the enzyme-linked immunosorbent assay (ELISA), which combines high sensitivity and specificity with strong signal amplification. However, ELISA and other heterogeneous methods require multiple, time-consuming washing and incubation steps, which limits their applicability in point-of-care diagnostics and high-throughput applications. In recent years, several new antibody detection strategies have been developed in which antibody binding and signal generation are integrated within a single biomolecular reporter. These strategies aim to rival ELISA in terms of sensitivity and specificity, while decreasing the time and effort required to perform an assay. Here, we review recent developments in this field according to their mechanism of action and discuss their advantages and limitations. PMID:24091607

  11. Washing of various lead compounds from a contaminated soil column

    SciTech Connect

    Davis, A.P.; Hotha, B.V. [Univ. of Maryland, College Park, MD (United States)

    1998-11-01

    Soil samples artificially contaminated with 10 different lead compounds to produce 5,000 mg/kg Pb were washed with acid and ethylenediaminetetraacetic acid (EDTA) solutions. For variable pH, the highest washing efficiencies were achieved at pH 2, the lowest value examined. Washing with EDTA enhanced the removal of lead, the removal increasing with an increase in the EDTA:lead molar ratio. High removals (70--106%) of adsorbed lead (as lead nitrate), lead carbonate, basic lead carbonate, lead sulfate, and lead oxide were achieved with both types of washing. Although not washed effectively with acid, significant lead dioxide removal occurred with EDTA wash. The removals of lead sulfide, lead paint, lead dimethyldithiocarbamate, and elemental lead were low (near 0--16%) under all washing conditions. The removal efficiency of the lead is affected by the compound solubility, lead solid dissolution kinetics, and lead sorption into the soil. Results clearly indicate the importance of the form of lead contamination in determining the success of a soil washing operation. Comparison of these results with other suggests that soil washing success and soil lead bioaccessibility are related phenomena.

  12. Natural laccase mediators separated from water-washed solution of steam exploded corn straw by nanofiltration and organic solvent fractionation.

    PubMed

    Qiu, Weihua; Zhang, Wenyan; Chen, Hongzhang

    2014-03-01

    Artificially synthetic mediators of laccase had the limitation of high cost and possible toxicity. The separation of natural laccase mediators from water-washed solution (WWS) of steam exploded corn straw (SECS) was studied using nano-filtration and successive organic solvents extraction. Results indicated that the UV absorption intensity of nano-filtrated WWS was significantly enhanced. The UV absorption intensity of each extractive from WWS could be ranked as ether extractive (EE)>ethyl acetate extractive (EAE)>chloroform extractive (CE). Decoloration of crystal violet catalyzed by laccase/EE was higher than that by laccase/ABTS, which was 66.95% and 61.9% at 8h, respectively. All the decoloration rates of malachite green at 60min using EE, EAE and ABTS as mediator were both more than 80%. This research would benefit for broaden the source of laccase mediator and reduce the using cost of laccase/mediator system. PMID:24513027

  13. Spray washing carcasses with alkaline solutions of lauric acid to reduce bacterial contamination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of lauric acid (LA)-potassium hydroxide (KOH) solutions to reduce carcass bacterial contamination was examined. Skin of carcasses was inoculated with a cecal paste containing antibiotic resistant strains of Escherichia coli, Salmonella Typhimirum, and Campylobacter coli. In one trial, in...

  14. Washing Dishes

    NSDL National Science Digital Library

    This experiment is about contaminiation. Learners will go through a series of steps in which they will test and observe how detergent breaks up contamination in a guided inquiry. Following this they will complete an open inquiry in which they ask questions about variables in washing dishes and design and conduct a test to answer these questions. Includes a teacher's guide and students handouts. Video and audio clips are provided. This lesson 4 of 10 from the Dynamic Design: The Cleanroom module.

  15. Washing off intensification of cotton and wool fabrics by ultrasounds.

    PubMed

    Peila, R; Actis Grande, G; Giansetti, M; Rehman, S; Sicardi, S; Rovero, G

    2015-03-01

    Wet textile washing processes were set up for wool and cotton fabrics to evaluate the potential of ultrasound transducers (US) in improving dirt removal. The samples were contaminated with an emulsion of carbon soot in vegetable oil and aged for three hours in fan oven. Before washing, the fabrics were soaked for 3 min in a standard detergent solution and subsequently washed in a water bath. The dirt removal was evaluated through colorimetric measurements. The total color differences ?E of the samples were measured with respect to an uncontaminated fabric, before and after each washing cycle. The percentage of ?E variation obtained was calculated and correlated to the dirt removal. The results showed that the US transducers enhanced the dirt removal and temperature was the parameter most influencing the US efficiency on the cleaning process. Better results were obtained at a lower process temperature. PMID:25258212

  16. Estimating the Contributions of Surface Wash-off and Channel Erosion to Total Sediment and Solute Loads in a Small Mixed Land Use Watershed

    NASA Astrophysics Data System (ADS)

    Nipper, J.; Bowden, W. B.

    2009-12-01

    Watershed sediment and solute loads originate from many different sources. These can include point sources, soil erosion, impervious surface wash-off, channel bank and bed erosion, and other sources depending on the land use activities within the watershed. However, the difficulties encountered in quantifying the contributions of specific nonpoint sources to watershed loads magnifies the uncertainty in watershed management efforts aimed at mitigating the pollutants. The goal of this research is to quantify the contribution of wash-off from residentially developed land and stream channel erosion to total watershed sediment and solute loadings within a 103 ha tributary watershed of Potash Brook, in Chittenden County, Vermont. To do so we deployed autosamplers at two stream cross sections and within two representative storm drain outfalls to sample TSS, TN, NO3-, TKN, TP, and Cl-. Samples were collected during storm events on a flow weighted composite basis, and by periodic base flow sampling. In stream sampling was conducted over a total 5 years and storm drain sampling covered a total of 2 years. Preliminary analysis of these data suggests that surface wash-off from developed portions of the watershed can generate greater than 90% of the TSS and greater than 50% of the Cl- loads measured at the watershed outlet sampling location. Currently, these data are being incorporated into an EPA-SWMM model of the watershed coupled with an evolutionary strategies parameter search algorithm. The model generated and measured wash-off data will be used with the measured load data at the watershed outlet to estimate the contribution of the stream channel by difference over all sampled events.

  17. Effectiveness of an anaerobic granular activated carbon fluidized-bed bioreactor to treat soil wash fluids: a proposed strategy for remediating PCP/PAH contaminated soils.

    PubMed

    Koran, K M; Suidan, M T; Khodadoust, A P; Sorial, G A; Brenner, R C

    2001-07-01

    An integrated system has been developed to remediate soils contaminated with pentachlorophenol (PCP) and polycyclic aromatic hydrocarbons (PAHs). This system involves the coupling of two treatment technologies, soil-solvent washing and anaerobic biotreatment of the extract. Specifically, this study evaluated the effectiveness of a granular activated carbon (GAC) fluidized-bed reactor to treat a synthetic-waste stream of PCP and four PAHs (naphthalene, acenaphthene, pyrene, and benzo(b)fluoranthene) under anaerobic conditions. This waste stream was intended to simulate the wash fluids from a soil washing process treating soils from a wood-preserving site. The reactor achieved a removal efficiency of greater than 99.8% for PCP with conversion to its dechlorination intermediates averaging 46.5%. Effluent, carbon extraction, and isotherm data also indicate that naphthalene and acenaphthene were removed from the liquid phase with efficiencies of 86 and 93%, respectively. Effluent levels of pyrene and benzo(b)fluoranthene were extremely low due to the high-adsorptive capacity of GAC for these compounds. Experimental evidence does not suggest that the latter two compounds were biochemically transformed within the reactor. PMID:11394769

  18. Part 2. Comparison of emergency washing solutions in 70% hydrofluoric acid-burned human skin in an established ex vivo explants model

    PubMed Central

    Burgher, François; Mathieu, Laurence; Lati, Elian; Gasser, Philippe; Peno-Mazzarino, Laurent; Blomet, Joël; Hall, Alan H; Maibach, Howard I

    2011-01-01

    Background: Hydrofluoric acid (HF) is a small and partially dissociated acid (pKa 3.2), able to deeply penetrate into human skin in addition to the corrosiveness of the hydrogen ion (H+) and the toxicity of the fluoride ion (F-). However, there has been a lack of experimental studies to objectively characterize the results of human HF skin exposure decontamination. Methodology/principal findings: A previously established experimental method using a human skin explants ex vivo model (Part 1. Experimental 70% hydrofluoric acid (HF) burns: Histological observations in an established human skin explants ex vivo model) described the lesions that appeared following 70% HF penetration. Within 5min, 70% HF penetrates to the dermis. Using the same experimental conditions, a comparison study of two different washing protocols was performed: water + topical calcium gluconate (CaG) versus Hexafluorine®. In these conditions, washing for 15min with running tap water followed by topical CaG ointment only delayed burn onset, while severe tissue damage appeared later. In contrast, after washing with Hexafluorine® over 10 min, no histological lesions developed. These results are in accordance with the results of accidental human industrial case reports. Conclusion/significance: Amphoteric and hypertonic Hexafluorine® can deactivate H+ and chelate F- ions. Based on these results, it should be considered as a promising first-aid decontamination solution to prevent or minimize significant local and systemic consequences of concentrated HF skin exposures. PMID:21083510

  19. SITE TECHNOLOGY CAPSULE: BIOGENESIS SOIL WASHING TECHNOLOGY

    EPA Science Inventory

    Soil washing technologies are designed to transfer contaminants from soil to a liquid phase. The BloGenesis? soil washing technology uses a proprietary surfactant solution to transfer organic contaminants from soil to wastewater. The surfactant used in the soil washing process wa...

  20. Aqueous solution dispersement of carbon nanotubes

    NASA Technical Reports Server (NTRS)

    Kim, Jae-Woo (Inventor); Park, Cheol (Inventor); Choi, Sang H. (Inventor); Lillehei, Peter T. (Inventor); Harrison, Joycelyn S. (Inventor)

    2011-01-01

    Carbon nanotubes (CNTs) are dispersed in an aqueous buffer solution consisting of at least 50 weight percent water and a remainder weight percent that includes a buffer material. The buffer material has a molecular structure defined by a first end, a second end, and a middle disposed between the first and second ends. The first end is a cyclic ring with nitrogen and oxygen heteroatomes, the middle is a hydrophobic alkyl chain, and the second end is a charged group.

  1. Osmotic coefficients of aqueous sodium carbonate solutions at 25°C

    Microsoft Academic Search

    R. A. Robinson; J. B. Macaskill

    1979-01-01

    Isopiestic vapor pressure measurements are reported for aqueous sodium carbonate solutions at 25°C using sodium chloride as reference electrolyte. Osmotic and activity coefficients are calculated from the concentrations of the solutions in isopiestic equilibrium. The results are used to calculate the trace activity coefficients of carbonate ion in sodium chloride solutions; these should approximate the trace activity coefficient of carbonate

  2. The pore solution phase of carbonated cement pastes

    Microsoft Academic Search

    D. J. Anstice; C. L. Page; M. M. Page

    2005-01-01

    Samples of hydrated cement pastes were exposed to atmospheres with various carbon dioxide concentrations at relative humidities controlled by different saturated salt solutions. When carbonated throughout their thickness, as indicated by the phenolphthalein test, they were resaturated with water and subjected to pore solution expression and analysis. The effects of the various carbonating environments on the pore solution composition and

  3. Kinetics of dodecanoic acid adsorption from caustic solution by activated carbon.

    PubMed

    Pendleton, Phillip; Wu, Sophie Hua

    2003-10-15

    This study examines the influences of adsorbent porosity and surface chemistry and of carbon dosage on dodecanoic acid adsorption kinetics from aqueous and 2 M NaOH solutions as batch adsorption processes. Both adsorbents are steam-activated carbons prepared from either coconut or coal precursors. Prior to use the adsorbents were washed in deionized water or 2 M NaOH. Mass transfer coefficients and effective overall diffusion coefficients indicate a minor contribution from adsorbent porosity. In contrast, high surface oxygen content impedes transport to and into the adsorbent structure. Carbon dosage shows a proportional increase in transport coefficients with increasing mass; these coefficients are constant when normalized per unit mass. Neither water nor NaOH treatment of the adsorbents has a significant influence on dodecanoic acid adsorption kinetics. Molecular and Knudsen diffusion coefficients are defined to demonstrate that the overall effective diffusion coefficient values and the diffusion process are controlled by surface diffusion. PMID:14527446

  4. A new antacid drug from activated carbon modified with calcium carbonate

    Microsoft Academic Search

    Carlos F. Linares; José Quintero; Lesbia Martínez; Gema González

    2007-01-01

    Activated carbons were previously modified with different sodium carbonate solutions and then, they were soaked in a calcium nitrate solution. This procedure allowed to precipitate calcium carbonate on the microporous carbons. Then, these solids were washed with abundant distillated water. These modified carbons were characterized by means of XRD, SEM, HRTEM and BET surface area measurements. XRD confirmed the presence

  5. Effect of water temperature, pressure and chemical solution on removal of fecal material and bacteria from lamb adipose tissue by spray-washing.

    PubMed

    Kochevar, S L; Sofos, J N; Levalley, S B; Smith, G C

    1997-03-01

    The objectives of this study were to determine the efficacy of various water temperatures, pressures and chemical solutions of spray-washing on the removal of fecal and bacterial contamination from lamb carcass samples taken from the breast area (< 15 min post mortem) and inoculated (6.50 cm(2) area) with an ovine fecal paste containing Escherichia coli (ATCC 11370). Inoculated samples were held for 15 min and then knife-trimmed and/or spraywashed with varying water temperatures (16, 35 or 74 °C), pressures (2.76, 13.79, 20.68 or 27.58 bar) and chemical solutions (12% trisodium phosphate, 2% acetic acid, 5% hydrogen peroxide or 0.003% available chlorine) for 18 s. After the respective treatments, samples were evaluated visually for presence of fecal material and microbiologically for aerobic plate counts (APC). Knife-trimming reduced (p < 0.05) APC of inoculated samples, while subsequent spray-washing of knife-trimmed samples reduced APC (p < 0.05), even compared to uninoculated control samples. Spray-washing with any temperature and pressure combination reduced (p < 0.05) visible fecal contamination on the samples. Bacterial reductions ranged from 1.48 to 3.83 log colony forming units (CFU/cm(2)) at the inoculation site. Use of 74 °C water was more effective (p < 0.05) in decreasing APC than either 16 or 35 °C water, while water pressure effects were similar. Use of 2% acetic acid reduced the APC more than the use of any other chemical solution tested. APC for the areas surrounding the inoculation site were similar to APC at the inoculation site; thus indicating that either there was no major spread of bacterial contamination to areas above or below the inoculation site or that contamination was diluted to levels lower than initial contamination. Overall, acetic acid and water temperature were the most important factors in reducing APC and fecal contamination on lamb adipose tissue. PMID:22061475

  6. The Comparative Photodegradation Activities of Pentachlorophenol (PCP) and Polychlorinated Biphenyls (PCBs) Using UV Alone and TiO2-Derived Photocatalysts in Methanol Soil Washing Solution

    PubMed Central

    Zhou, Zeyu; Zhang, Yaxin; Wang, Hongtao; Chen, Tan; Lu, Wenjing

    2014-01-01

    Photochemical treatment is increasingly being applied to remedy environmental problems. TiO2-derived catalysts are efficiently and widely used in photodegradation applications. The efficiency of various photochemical treatments, namely, the use of UV irradiation without catalyst or with TiO2/graphene-TiO2 photodegradation methods was determined by comparing the photodegadation of two main types of hydrophobic chlorinated aromatic pollutants, namely, pentachlorophenol (PCP) and polychlorinated biphenyls (PCBs). Results show that photodegradation in methanol solution under pure UV irradiation was more efficient than that with either one of the catalysts tested, contrary to previous results in which photodegradation rates were enhanced using TiO2-derived catalysts. The effects of various factors, such as UV light illumination, addition of methanol to the solution, catalyst dosage, and the pH of the reaction mixture, were examined. The degradation pathway was deduced. The photochemical treatment in methanol soil washing solution did not benefit from the use of the catalysts tested. Pure UV irradiation was sufficient for the dechlorination and degradation of the PCP and PCBs. PMID:25254664

  7. Activity of trisodium phosphate compared with sodium hydroxide wash solutions against Listeria monocytogenes attached to chicken skin during refrigerated storage

    Microsoft Academic Search

    R Capita; C Alonso-Calleja; M del Camino Garc??a-Fernández; B Moreno

    2002-01-01

    The potential of using trisodium phosphate (TSP) and sodium hydroxide (NaOH) to reduce Listeria monocytogenes populations in chicken skin was studied. Raw chicken legs inoculated with L. monocytogenes were dipped in water (control), in 8% (pH=12·59), 10% (pH=12·68) and 12% (pH=12·75) (w\\/v) TSP solutions, or in NaOH solutions of equal pH values to those of TSP: 0·175%, 0·200% and 0·220%

  8. Physicochemical foundations of spent nuclear fuel leaching in carbonate solutions

    Microsoft Academic Search

    S. I. Stepanov; A. V. Boyarintsev; A. M. Chekmarev

    2009-01-01

    The earlier work by Stepanov and Chekmarev [1] formulated the new strategy for aqueous chemical recycling of spent nuclear fuel (SNF) in carbonate solutions referred to as the CarbEx process. This strategy comprises the leaching of SNF to aqueous carbonate solution, from which the extraction refining of uranium and plutonium is carried out using quaternary ammonium salts; solid-phase stripping of

  9. Stability of calcium carbonate and magnesium carbonate in rainwater and nitric acid solutions

    Microsoft Academic Search

    Sebastian Teir; Sanni Eloneva; Carl-Johan Fogelholm; Ron Zevenhoven

    2006-01-01

    Carbonation of magnesium and calcium silicates has emerged as an interesting option for long term storage of captured CO2. However, carbonated minerals are not stable in acidic environments. This study was conducted to determine if synthetically carbonated minerals dissolve in acidic rain and release CO2. Synthetic magnesium and calcium carbonates were leached in nitric acid solutions of various acidities, as

  10. Chromium wash & leach factors

    SciTech Connect

    LAMBERT, S.L.; MEACHAM, J.E.

    2003-04-24

    This report estimates chromium wash and leach factors using a waste type modeling approach. The model produces reasonable chromium wash-leach factor predictions that can be used in the Hanford Tank Waste Operations Simulator model.

  11. Soil Deposition and the Electrokinetic Behaviour of Shrink-resist Wool Fabrics during Washing with Surfactant Mixtures at Different pH Levels

    Microsoft Academic Search

    F. J. Carrión Fité

    1992-01-01

    This paper deals with the behaviour of anionic and non-ionic surfactants, separately and in different mixture ratios, in deposition during the washing of a standard solid impurity, such as carbon black, on wool fabrics treated with various agents to make them shrink-resistant in solutions of different pH. The variation of the electric double layer of fabrics in the washing solution,

  12. Crystallization characteristics of ammonium uranyl carbonate (AUC) in ammonium carbonate solutions

    NASA Astrophysics Data System (ADS)

    Tae-Joon, Kim; Kyung-Chai, Jeong; Jin-Ho, Park; In-Soon, Chang; Cheong-Song, Choi

    1994-05-01

    Ammonium carbonate solutions with an excessive amount of NH 3 were produced in a commercial AUC (ammonium uranyl carbonate) conversion plant. In this study the AUC crystals, precipitated with uranyl nitrate and ammonium carbonate solutions prepared in the laboratory, were characterized to determine the feasibility of recycling ammonium carbonate solution. The AUC crystals were easily agglomerated with the increasing concentration of CO 32- and mole ratio of {NH 4+}/{CO 32-} in ammonium carbonate solution. Effects of a mixing system for the solution in the AUC crystallizer and the feed location of the solution on the agglomeration of AUC crystals were also studied along with the effects of agglomerated AUC powders on UO 2 powders. Finally, the feasibility of manufacturing UO 2 fuel with a sintered pellet density of 10.52 g/cm 3, using the AUC powders generated in this experiment, was demonstrated.

  13. Dissolution of Spent Nuclear Fuel in Carbonate-Peroxide Solution

    SciTech Connect

    Soderquist, Chuck Z.; Hanson, Brady D.

    2010-01-31

    This study shows that spent UO2 fuel can be completely dissolved in a carbonate-peroxide solution apparently without attacking the metallic Mo-Tc-Ru-Rh-Pd fission product phase. Samples of spent nuclear fuel were pulverized and sieved to a uniform size, then duplicate aliquots were weighed into beakers for analysis. One set was dissolved in near-boiling 10M nitric acid, and the other set was dissolved in a solution of ammonium carbonate and hydrogen peroxide at room temperature. All the resulting fuel solutions were then analyzed for Sr-90, Tc-99, Cs-137, plutonium, and Am-241. For all the samples, the concentrations of Cs-137, Sr-90, plutonium, and Am-241 were the same for both the nitric acid dissolution and the ammonium carbonate-hydrogen peroxide dissolution, but the technetium concentration of the ammonium carbonate-hydrogen peroxide fuel solution was only about 25% of the same fuels dissolved in hot nitric acid.

  14. Solute carbon and carbon segregation in magnesium oxide single crystals — a secondary ion mass spectrometry study

    Microsoft Academic Search

    Friedemann Freund

    1986-01-01

    If carbon is to be analyzed by secondary ion mass spectroscopy (SIMS) in an oxide such as MgO, one has to know how the carbon is incorporated in the oxide host structure, before a successful experiment can be planned. If the carbon impurities derive from dissolved CO2 component which form a solid solution while the crystal grew from a melt

  15. Viability and functional integrity of washed platelets

    SciTech Connect

    Pineda, A.A.; Zylstra, V.W.; Clare, D.E.; Dewanjee, M.K.; Forstrom, L.A.

    1989-07-01

    The viability and functional integrity of saline- and ACD-saline-washed platelets were compared with those of unwashed platelets. After template bleeding time (TBT) was measured, 15 healthy volunteers underwent plateletpheresis and ingested 600 mg of aspirin. Autologous /sup 111/In-labeled platelets were transfused: unwashed (n = 5), washed with 0.9 percent saline solution (SS) (n = 5), and washed with a buffered 12.6 percent solution of ACD-A in 0.9 percent saline solution (n = 5). After transfusion, we measured TBT at 1, 4, and 24 hours; platelet survival at 10 minutes and 1, 4, and 24 hours and daily for 6 days; and the percentage of uptake in liver and spleen by quantitative whole-body radionuclide scintigraphy at 24 and 190 hours. We found that saline washing affected platelet recovery, 23.47 +/- 12 percent (p less than 0.001) as compared to 52.43 +/- 17 percent (p less than 0.002) for ACD-saline and 73.17 +/- 8 percent for control; that saline washing resulted in a greater liver uptake than control and ACD-saline-washed platelets (31.9 +/- 8% (p less than 0.001) vs 17.7 +/- 4.1 and 19.3 +/- 2.1% (p greater than 0.1), respectively); that, unlike control and ACD-saline-washed platelets, saline-washed platelets did not shorten bleeding time; and that neither type of washing affected survival. Although ACD-saline washing affects recovery, it also results in intact function, normal survival, higher recovery than SS platelets, and no significant liver uptake.

  16. BIOGENESIS SOIL WASHING TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    Soil washing technologies are designed to transfer contaminants from soil to a liquid phase. he BioGenesis Soil Washing Technology uses soil washing with a proprietary surfactant solution to transfer organic contaminants from soils to wastewater. ontaminant levels are further red...

  17. EPA'S MOBILE VOLUME REDUCTION UNIT FOR SOIL WASHING

    EPA Science Inventory

    This paper discusses the design and initial operation of the U.S. Environmental Protection Agency'S (EPA) Mobile Volume Reduction Unit (VRU) for soil washing. oil washing removes contaminants from soils by dissolving or suspending them in the wash solutions (which can be later tr...

  18. Wash This Way

    NSDL National Science Digital Library

    American Chemical Society

    2011-01-01

    In this activity on page 4 of the PDF, learners investigate the importance of washing their hands. Learners "dirty" their hands with cooking spray and glitter and then clean their hands using various hand-washing techniques. Learners compare the hand-washing techniques and discuss how germs can be harmful. Safety notes: Safety goggles are required. Follow all of Milli's safety tips on the bottom of the page.

  19. Wash water recovery system

    NASA Technical Reports Server (NTRS)

    Deckman, G.; Rousseau, J. (editor)

    1973-01-01

    The Wash Water Recovery System (WWRS) is intended for use in processing shower bath water onboard a spacecraft. The WWRS utilizes flash evaporation, vapor compression, and pyrolytic reaction to process the wash water to allow recovery of potable water. Wash water flashing and foaming characteristics, are evaluated physical properties, of concentrated wash water are determined, and a long term feasibility study on the system is performed. In addition, a computer analysis of the system and a detail design of a 10 lb/hr vortex-type water vapor compressor were completed. The computer analysis also sized remaining system components on the basis of the new vortex compressor design.

  20. Development assessment of wash water reclamation

    NASA Technical Reports Server (NTRS)

    Putnam, D. F.

    1976-01-01

    An analytical study assessment of state-of-the-art wash water reclamation technology is presented. It covers all non-phase-change unit operations, unit processes and subsystems currently under development by NASA. Each approach to wash water reclamation is described in detail. Performance data are given together with the projected weights and sizes of key components and subsystems. It is concluded that a simple multifiltration subsystem composed of surface-type cartridge filters, carbon adsorption and ion exchange resins is the most attractive approach for spacecraft wash water reclamation in earth orbital missions of up to 10 years in duration.

  1. Inhibition Of Washed Sludge With Sodium Nitrite

    SciTech Connect

    Congdon, J. W.; Lozier, J. S.

    2012-09-25

    This report describes the results of electrochemical tests used to determine the relationship between the concentration of the aggressive anions in washed sludge and the minimum effective inhibitor concentration. Sodium nitrate was added as the inhibitor because of its compatibility with the DWPF process. A minimum of 0.05M nitrite is required to inhibit the washed sludge simulant solution used in this study. When the worst case compositions and safety margins are considered, it is expected that a minimum operating limit of nearly 0.1M nitrite will be specified. The validity of this limit is dependent on the accuracy of the concentrations and solubility splits previously reported. Sodium nitrite additions to obtain 0.1M nitrite concentrations in washed sludge will necessitate the additional washing of washed precipitate in order to decrease its sodium nitrite inhibitor requirements sufficiently to remain below the sodium limits in the feed to the DWPF. Nitrite will be the controlling anion in "fresh" washed sludge unless the soluble chloride concentration is about ten times higher than predicted by the solubility splits. Inhibition of "aged" washed sludge will not be a problem unless significant chloride dissolution occurs during storage. It will be very important tomonitor the composition of washed sludge during processing and storage.

  2. Laundry: Washing Infected Material

    MedlinePLUS

    ... reduction of microbial contamination can be achieved at water temperatures lower than 160°F if laundry chemicals suitable for low-temperature washing are used at proper concentrations. In the home, normal washing and drying cycles including "hot" or "cold" cycles are adequate to ...

  3. Room environment influence on eggshell bacterial levels of non-washed and washed eggs from caged and cage-free laying hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The bacteria levels of non-washed and washed eggs obtained from caged and cage-free hens housed in either wire slats or shaving-covered pens were determined. On eight days (from 22 to 52 wk), 20 eggs were collected from each pen. Ten eggs/pen were washed with a commercial egg washing solution, whi...

  4. 3. VIEW LOOKING NORTH AT CHINA WASH FLUME SHOWING WASH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VIEW LOOKING NORTH AT CHINA WASH FLUME SHOWING WASH - San Carlos Irrigation Project, China Wash Flume, Main (Florence-Case Grande) Canal at Station 137+00, T4S, R10E, S14, Coolidge, Pinal County, AZ

  5. Kinetics of absorption of carbon dioxide in aqueous piperazine solutions

    Microsoft Academic Search

    P. W. J. Derks; T. Kleingeld; C. van Aken; J. A. Hogendoorn; G. F. Versteeg

    2006-01-01

    In the present work the absorption of carbon dioxide into aqueous piperazine (PZ) solutions has been studied in a stirred cell, at low to moderate temperatures, piperazine concentrations ranging from 0.6 to 1.5kmolm-3, and carbon dioxide pressures up to 500mbar, respectively. The obtained experimental results were interpreted using the DeCoursey equation [DeCoursey, W., 1974. Absorption with chemical reaction: development of

  6. ARTICLE Evolution Mechanism of Calcium Carbonate in Solution

    Microsoft Academic Search

    Ya-ping Guo; Hai-xiong Tang; Yu Zhou; De-chang Jia; Cong-qin Ning; Ya-jun Guo

    2010-01-01

    Calcium carbonate was synthesized in a CaCl2\\/NaCO3 mixed solution by using ethylenediaminetetraacetic acid (EDTA) as an additive. The thermodynamics and kinetics analyses indicate that although the driving force of amorphous calcium carbonate (ACC) precipitation is always less than that of calcite and vaterite precipitation, the nucleation rate of ACC is greater than that of calcite and vaterite at the initial

  7. Remediation of cadmium-contaminated paddy soils by washing with chemicals: effect of soil washing on cadmium uptake by soybean.

    PubMed

    Maejima, Yuji; Makino, Tomoyuki; Takano, Hiroyuki; Kamiya, Takashi; Sekiya, Naoki; Itou, Tadashi

    2007-03-01

    We conducted a pot experiment to evaluate the effect of soil washing with CaCl(2) on Cd absorption by two soybean cultivars. The results were as follows: (1) Soybean growth was not significantly different in washed and unwashed soils, but the seed Cd concentration for both cultivars decreased significantly, up to 25%, in the washed soils compared with the unwashed soils. (2) In the washed soils, the Cd concentration in the soil solution indicated an obviously lower value from sowing to the flowering stage; however, the change in Cd speciation was not evident in the CaCl(2)-washed soil solution. Consequently, the effect of soil washing using CaCl(2) on Cd-contaminated paddy soils can be expected to continue after a CaCl(2)-washed paddy field is converted to an upland field. PMID:17141294

  8. Electrosorption of Ions from Aqueous Solutions by Nanostructured Carbon Aerogel

    Microsoft Academic Search

    Tung-Yu Ying; Kun-Lin Yang; Sotira Yiacoumi; Costas Tsouris

    2002-01-01

    Electrosorption is generally defined as potential-induced adsorption on the surface of charged electrodes. After polarization of the electrodes, ions are removed from the electrolyte solution by the imposed electric field and adsorbed onto the surface of the electrodes. Experimental and modeling studies were conducted using two types of carbon aerogel composites of different surface areas to provide a better understanding

  9. Removal of methylene blue from aqueous solution by wood millet carbon optimization using response surface methodology.

    PubMed

    Ghaedi, Mehrorang; Nasiri Kokhdan, Syamak

    2015-02-01

    The use of cheep, non-toxic, safe and easily available adsorbent are efficient and recommended material and alternative to the current expensive substance for pollutant removal from wastewater. The activated carbon prepared from wood waste of local tree (millet) extensively was applied for quantitative removal of methylene blue (MB), while simply. It was used to re-used after heating and washing with alkaline solution of ethanol. This new adsorbent was characterized by using BET surface area measurement, FT-IR, pH determination at zero point of charge (pHZPC) and Boehm titration method. Response surface methodology (RSM) by at least the number of experiments main and interaction of experimental conditions such as pH of solution, contact time, initial dye concentration and adsorbent dosage was optimized and set as pH 7, contact time 18 min, initial dye concentration 20 ppm and 0.2 g of adsorbent. It was found that variable such as pH and amount of adsorbent as solely or combination effects seriously affect the removal percentage. The fitting experimental data with conventional models reveal the applicability of isotherm models Langmuir model for their well presentation and description and Kinetic real rate of adsorption at most conditions efficiently can be represented pseudo-second order, and intra-particle diffusion. It novel material is good candidate for removal of huge amount of MB (20 ppm) in short time (18 min) by consumption of small amount (0.2 g). PMID:25315868

  10. Removal of methylene blue from aqueous solution by wood millet carbon optimization using response surface methodology

    NASA Astrophysics Data System (ADS)

    Ghaedi, Mehrorang; Kokhdan, Syamak Nasiri

    2015-02-01

    The use of cheep, non-toxic, safe and easily available adsorbent are efficient and recommended material and alternative to the current expensive substance for pollutant removal from wastewater. The activated carbon prepared from wood waste of local tree (millet) extensively was applied for quantitative removal of methylene blue (MB), while simply. It was used to re-used after heating and washing with alkaline solution of ethanol. This new adsorbent was characterized by using BET surface area measurement, FT-IR, pH determination at zero point of charge (pHZPC) and Boehm titration method. Response surface methodology (RSM) by at least the number of experiments main and interaction of experimental conditions such as pH of solution, contact time, initial dye concentration and adsorbent dosage was optimized and set as pH 7, contact time 18 min, initial dye concentration 20 ppm and 0.2 g of adsorbent. It was found that variable such as pH and amount of adsorbent as solely or combination effects seriously affect the removal percentage. The fitting experimental data with conventional models reveal the applicability of isotherm models Langmuir model for their well presentation and description and Kinetic real rate of adsorption at most conditions efficiently can be represented pseudo-second order, and intra-particle diffusion. It novel material is good candidate for removal of huge amount of MB (20 ppm) in short time (18 min) by consumption of small amount (0.2 g).

  11. TANK 7 CHARACTERIZATION AND WASHING STUDIES

    SciTech Connect

    Lambert, D.; Pareizs, J.; Click, D.

    2010-02-04

    A 3-L PUREX sludge sample from Tank 7 was characterized and then processed through a series of inhibited water washes to remove oxalate, sodium, and other soluble ions. Current plans use Tank 7 as one of the feed sources for Sludge Batch 7 (SB7). Tank 7 is high in oxalate due to the oxalic acid cleaning of the sludge heels from Tanks 5 and 6 and subsequent transfer to Tank 7. Ten decant and nine wash cycles were performed over a 47 day period at ambient temperature. Initially, seven decants and seven washes were completed based on preliminary estimates of the number of wash cycles required to remove the oxalate in the sludge. After reviewing the composition data, SRNL recommended the completion of 2 or 3 more decant/wash cycles to ensure all of the sodium oxalate had redissolved. In the first 7 washes, the slurry oxalate concentration was 12,300 mg/kg (69.6% oxalate removal compared to 96.1% removal of the other soluble ions). After all ten decants were complete, the slurry oxalate concentration was 3,080 mg/kg (89.2% oxalate removal compared to 99.0% of the other soluble ions). The rate of dissolution of oxalate increased significantly with subsequent washes until all of the sodium oxalate had been redissolved after seven decant/wash cycles. The measured oxalate concentrations agreed very well with LWO predictions for washing of the Tank 7 sample. Highlights of the analysis and washing of the Tank 7 sample include: (1) Sodium oxalate was detected in the as-received filtered solids. 95% of the oxalate was insoluble (undissolved) in the as-received slurry. (2) No sodium oxalate was detected in the post-wash filtered solids. (3) Sodium oxalate is the last soluble species that redissolves during washing with inhibited water. In order to significantly reduce the sodium oxalate concentration, the sludge must be highly washed, leaving the other soluble anions and cations (including sodium) very low in concentration. (4) The post-wash slurry had 1% of the soluble anions and cations remaining, with the exception of sodium and oxalate, for which the percentages were 2.8% and 10.8% respectively. The post-wash sodium concentration was 9.25 wt% slurry total solids basis and 0.15 M supernate. (5) The settling rate of slurry was very fast allowing the completion of one decant/wash cycle each day. (6) The measured yield stress of as-received (6.42 wt% undissolved solids) and post-wash (7.77 wt% undissolved solids) slurry was <1 Pa. For rapidly settling slurries, it can be hard to measure the yield stress of the slurry so this result may be closer to the supernate result than the slurry. The recommended strategy for developing the oxalate target for sludge preparation for Sludge Batch 7 includes the following steps: (1) CPC simulant testing to determine the percent oxalate destruction and acid mix needed to produce a predicted redox of approximately 0.2 Fe{sup +2}/{Sigma}Fe in a SME product while meeting all DWPF processing constraints. (2) Perform a DWPF melter flammability assessment to ensure that the additional carbon in the oxalate together with other carbon sources will not lead to a flammability issue. (3) Perform a DWPF glass paper assessment to ensure the glass produced will meet all DWPF glass limits due to the sodium concentration in the sludge batch. The testing would need to be repeated if a significant CPC processing change, such as an alternative reductant to formic acid, is implemented.

  12. Behavior of carbon isotopes during the hyperfiltration of calcium carbonate solutions through calcium bentonites

    E-print Network

    Hinz, David William

    1987-01-01

    (aq) The 1sotopic ratio of the effluent gave no clue to the possible occurrence of any fractionation of carbon 1sotopes. The solution retained on the high pressure s1de of the membrane was found to have an increased calcium concentration, as would... the stock solution's COB(aq) concentration. This is interpreted as conversion of bicarbonate to CO7(aq) along or within the membrane, with subsequent transport of the C02~a ~ through the membrane. The carbon isotopic ratio of the throughput solution...

  13. Simultaneous leaching and carbon sequestration in constrained aqueous solutions

    SciTech Connect

    Phelps, Tommy Joe [ORNL; Moon, Ji Won [ORNL; Roh, Yul [Chonnam National University, Gwangju; Cho, Kyu Seong [ORNL

    2011-01-01

    The behavior of metal ions leaching and precipitated mineral phases of metal-rich fly ash (FA) was examined in order to evaluate microbial impacts on carbon sequestration and metal immobilization. The leaching solutions consisted of aerobic deionized water (DW) and artificial eutrophic water (AEW) that was anaerobic, organic- and mineral-rich, and higher salinity as is typical of bottom water in eutrophic algae ponds. The Fe- and Ca-rich FAs were predominantly composed of quartz, mullite, portlandite, calcite, hannebachite, maghemite, and hematite. After 86 days, only Fe and Ca contents exhibited a decrease in leaching solutions while other major and trace elements showed increasing or steady trends in preference to the type of FA and leaching solution. Ca-rich FA showed strong carbon sequestration efficiency ranging up to 32.3 g CO(2)/kg FA after 86 days, corresponding to almost 65% of biotic carbon sequestration potential under some conditions. Variations in the properties of FAs such as chemical compositions, mineral constituents as well as the type of leaching solution impacted CO(2) capture. Even though the relative amount of calcite increased sixfold in the AEW and the relative amount of mineral phase reached 37.3 wt% using Ca-rich FA for 86 days, chemical sequestration did not accomplish simultaneous precipitation and sequestration of several heavy metals.

  14. Soil washing technology evaluation

    SciTech Connect

    Suer, A.

    1995-04-01

    Environmental Restoration Engineering (ERE) continues to review innovative, efficient, and cost effective technologies for SRS soil and/or groundwater remediation. As part of this effort, this technical evaluation provides review and the latest information on the technology for SRS soil remediation. Additional technology evaluation reports will be issued periodically to update these reports. The purpose of this report is to review the soil washing technology and its potential application to SRS soil remediation. To assess whether the Soil Washing technology is a viable option for SRS soil remediation, it is necessary to review the technology/process, technology advantages/limitations, performance, applications, and cost analysis.

  15. Kinetics of pyrite oxidation in sodium carbonate solutions

    Microsoft Academic Search

    V. S. T. Ciminelli; K. Osseo-Asare

    1995-01-01

    The kinetics of pyrite oxidation in sodium carbonate solutions were investigated in a stirred vessel, under temperatures ranging\\u000a from 50 °C to 85 °C, oxygen partial pressures from 0 to 1 atm, particle size fractions from ?150 + 106 to ?38 + 10 µm (?100\\u000a + 150 Mesh to ?400 Mesh + 10 µm) and pH values of up to

  16. Pyrite oxidation in carbonate-buffered solution: 1. Experimental kinetics

    Microsoft Academic Search

    R. V. Nicholson; R. W. Gillham; E. J. Reardon

    1988-01-01

    The kinetic behavior of pyrite oxidation in carbonate-buffered solution was investigated in the laboratory. Oxygen concentration, surface area and temperature were varied while pH values were limited to the range of 6.7-8.5. The rate experiments were performed on crushed and sieved size-fractions of pyrite that were carefully cleaned and mixed with similar-size silica sand. Oxidation occurred in a moisture-suction device

  17. Hydrogen and carbon in solid solution in oxides and silicates

    Microsoft Academic Search

    Friedemann Freund

    1987-01-01

    The dissolution of H2O and CO2 in structurally dense, nominally anhydrous and non-carbonate oxide matrices such as MgO and CaO is reviewed. H2O and CO2 are treated as gaseous oxide components which enter into solid solution with the refractory oxide hosts. They form anion complexes associated with cation vacancy sites. Evidence is presented that OH- pairs which derive from the

  18. Absorption of Carbon Dioxide into Aqueous Colloidal Silica Solution

    Microsoft Academic Search

    2006-01-01

    On the basis of experimental data for carbon dioxide absorption into aqueous nanometer sized colloidal silica solution as a non?Newtonian fluid, a dimensionless correlation for volumetric liquid?side mass transfer coefficient (kLa) of CO2 in the flat?stirred vessel was proposed. In addition to ordinary liquid properties and operating parameters such as impeller size and speed in the vessel, Deborah number, which

  19. Insights into non-Fickian solute transport in carbonates

    PubMed Central

    Bijeljic, Branko; Mostaghimi, Peyman; Blunt, Martin J

    2013-01-01

    [1] We study and explain the origin of early breakthrough and long tailing plume behavior by simulating solute transport through 3-D X-ray images of six different carbonate rock samples, representing geological media with a high degree of pore-scale complexity. A Stokes solver is employed to compute the flow field, and the particles are then transported along streamlines to represent advection, while the random walk method is used to model diffusion. We compute the propagators (concentration versus displacement) for a range of Peclet numbers (Pe) and relate it to the velocity distribution obtained directly on the images. There is a very wide distribution of velocity that quantifies the impact of pore structure on transport. In samples with a relatively narrow spread of velocities, transport is characterized by a small immobile concentration peak, representing essentially stagnant portions of the pore space, and a dominant secondary peak of mobile solute moving at approximately the average flow speed. On the other hand, in carbonates with a wider velocity distribution, there is a significant immobile peak concentration and an elongated tail of moving fluid. An increase in Pe, decreasing the relative impact of diffusion, leads to the faster formation of secondary mobile peak(s). This behavior indicates highly anomalous transport. The implications for modeling field-scale transport are discussed. Citation: Bijeljic, B., P. Mostaghimi, and M. J. Blunt (2013), Insights into non-Fickian solute transport in carbonates, Water Resour. Res., 49, 2714–2728, doi:10.1002/wrcr.20238. PMID:24223444

  20. The effects of alkalinity and acidity of process water and hydrochar washing on the adsorption of atrazine on hydrothermally produced hydrochar.

    PubMed

    Flora, Justine F R; Lu, Xiaowei; Li, Liang; Flora, Joseph R V; Berge, Nicole D

    2013-11-01

    Hydrothermal carbonization of simulated food waste was performed at 250 °C for 20 h using deionized water (DI) and 0.01 N solutions of HCl, NaCl, and NaOH. The hydrochars produced were washed with acetone and the adsorptive capacity of the washed and unwashed hydrochars for atrazine were characterized. Using a generalized linear model, it was shown that the adsorptive capacity of the washed hydrochar was significantly higher than that of the unwashed hydrochars. The HCl processed unwashed hydrochar has a slightly higher adsorptive capacity compared to the DI processed hydrochar while both the NaOH processed washed and unwashed hydrochars were slightly lower than the corresponding DI processed hydrochars. (13)C solid-state NMR results showed no discernible differences in surface functional groups among the washed hydrochars and among the unwashed hydrochars. A clear decrease in alkyl groups and an increase in aromatic/olefinic-C groups were observed after acetone washing. (1)H liquid-phase NMR showed carbon alkyl chains were present in the acetone wash. Interaction energies calculated using dispersion corrected density functional theory show that atrazine is more strongly adsorbed to surfaces without weakly associated alkyl groups. PMID:23931904

  1. Version 3.0 SOP 14 --Sodium carbonate solutions October 12, 2007 Page 1 of 3

    E-print Network

    Version 3.0 SOP 14 -- Sodium carbonate solutions October 12, 2007 Page 1 of 3 SOP 14 Procedure for preparing sodium carbonate solutions for the calibration of coulometric CT measurements 1. Scope and field of application This procedure describes the preparation of a set of aqueous sodium carbonate solutions which

  2. Washing of various lead compounds from a contaminated soil column

    Microsoft Academic Search

    Allen P. Davis; Bhaumik V. Hotha

    1998-01-01

    Soil samples artificially contaminated with 10 different lead compounds to produce 5,000 mg\\/kg Pb were washed with acid and ethylenediaminetetraacetic acid (EDTA) solutions. For variable pH, the highest washing efficiencies were achieved at pH 2, the lowest value examined. Washing with EDTA enhanced the removal of lead, the removal increasing with an increase in the EDTA:lead molar ratio. High removals

  3. Domestic wash water reclamation

    NASA Technical Reports Server (NTRS)

    Hall, J. B., Jr.; Batten, C. E.; Wilkins, J. R.

    1974-01-01

    System consists of filtration unit, reverse-osmosis module, tanks, pumps, plumbing, and various gauges, meters, and valves. After water is used in washing machine or shower, it is collected in holding tank. Water is pumped through series of five particulate filters. Pressure tank supplies processed water to commode water closet.

  4. Soil washing treatability study

    SciTech Connect

    Krstich, M.

    1995-12-01

    Soil washing was identified as a viable treatment process option for remediating soil at the FEMP Environmental Management Project (FEMP). Little information relative to the specific application and potential effectiveness of the soil washing process exists that applies to the types of soil at the FEMP. To properly evaluate this process option in conjunction with the ongoing FEMP Remedial Investigation/Feasibility Study (RI/FS), a treatability testing program was necessary to provide a foundation for a detailed technical evaluation of the viability of the process. In August 1991, efforts were initiated to develop a work plan and experimental design for investigating the effectiveness of soil washing on FEMP soil. In August 1992, the final Treatability Study Work Plan for Operable Unit 5: Soil Washing (DOE 1992) was issued. This document shall be referenced throughout the remainder of this report as the Treatability Study Work Plan (TSWP). The purpose of this treatability study was to generate data to support initial screening and the detailed analysis of alternatives for the Operable Unit 5 FS.

  5. DEMONSTRATION BULLETIN: BIOGENESIS SOIL WASHING TECHNOLOGY - BIOGENESIS

    EPA Science Inventory

    The BioGenesisSM soil washing technology was developed by BioGenesis Enterprises, Inc. to remove organic compounds from soil. The technology uses a proprietary solution (BioGenesisSM cleaner) to transfer organic compounds from the soil matrix to a liquid phase. BioGenesis claims...

  6. Aluminum Wash and Leach Factors

    SciTech Connect

    MEACHAM, J.E.

    2003-07-10

    This report estimates aluminum wash and leach factors using a waste type modeling approach. The model produces reasonable aluminum wash-leach factor predictions that can be used in the Hanford Tank Waste Operations Simulator model.

  7. Fluidic delivery of homogeneous solutions through carbon tube bundles

    NASA Astrophysics Data System (ADS)

    Srikar, R.; Yarin, A. L.; Megaridis, C. M.

    2009-07-01

    A wide array of technological applications requires localized high-rate delivery of dissolved compounds (in particular, biological ones), which can be achieved by forcing the solutions or suspensions of such compounds through nano or microtubes and their bundled assemblies. Using a water-soluble compound, the fluorescent dye Rhodamine 610 chloride, frequently used as a model drug release compound, it is shown that deposit buildup on the inner walls of the delivery channels and its adverse consequences pose a severe challenge to implementing pressure-driven long-term fluidic delivery through nano and microcapillaries, even in the case of such homogeneous solutions. Pressure-driven delivery (3-6 bar) of homogeneous dye solutions through macroscopically-long (~1 cm) carbon nano and microtubes with inner diameters in the range 100 nm-1 µm and their bundled parallel assemblies is studied experimentally and theoretically. It is shown that the flow delivery gradually shifts from fast convection-dominated (unobstructed) to slow jammed convection, and ultimately to diffusion-limited transport through a porous deposit. The jamming/clogging phenomena appear to be rather generic: they were observed in a wide concentration range for two fluorescent dyes in carbon nano and microtubes, as well as in comparable transparent glass microcapillaries. The aim of the present work is to study the physics of jamming, rather than the chemical reasons for the affinity of dye molecules to the tube walls.

  8. Wheat Evolution: Dough Washing

    NSDL National Science Digital Library

    Biotechnology and Biological Sciences Research Council

    2012-01-01

    In this activity (page 5), learners investigate the evolution of wheat by washing different types of dough with water and comparing the results. The evolution of wheat from wild grasses demonstrates the dramatic effect of both natural and directed evolution on the structure of a crop plant and the chemical makeup of the product harvested from it. These activities illustrate the changes to both the structure and the chemistry of the wheat plant.

  9. Biogenesis (trade name) soil washing technology: Innovative technology evaluation report

    SciTech Connect

    Bannerjee, P.

    1993-09-02

    Soil washing technologies are designed to transfer contaminants from soil to a liquid phase. The BioGenesis Soil Washing Technology uses soil washing with a proprietary surfactant solution to transfer organic contaminants from soils to wastewater. The BioGenesis soil washing process was evaluated under the SITE program at a refinery where soils were contaminated with crude oil. Results of chemical analyses show that levels of total recoverable petroleum hydrocarbons (TRPH), an indicator of degraded crude oil, decreased by 65 to 73 percent in washed soils. The TRPH in residual soils were allowed to biodegrade for an additional 120 days. Results indicate that soil washing and biodegradation removed 85 to 88 percent of TRPH in treated soils. The Innovative Technology Evaluation Report provides information on the technology applicability, economic analysis, technology limitations, a technology description, process residuals, site requirements, latest performance data, the technology status, vendors claims, and the source of further information.

  10. Study of Soil Washing for Remediation of Pb and Zn Contaminated Coastal Landfill

    NASA Astrophysics Data System (ADS)

    Park, S.; Kim, S.; Lee, M.

    2013-12-01

    As a result of analyzing the pre-treatment process of Pb, Zn in contaminated coastal landfill soil presented by Korean Soil Analysis Method, the each concentration was presented 577.00mg/kg, 3894.34mg/kg. This soil was critically contaminated with Pb and Zn because it was exceeded the Standard of soil contamination(2area: Pb-400mg/kg, Zn-600mg/kg). Soil remediation efficiency of the soil washing process for the removal of Pb and Zn was determined to be consistent with the results. The batch experiment on the several washing solutions(HCl, HNO3), washing solutions concentrations(0.1-0.8M) and the ratio of soil vs. solution for soil washing(1:3, 1:5 and 1:10) was performed. The results of experiments, washing time was appropriate in 30 minutes. The removal efficiency of soil washing increased as the ratio of soil vs. washing solution increased. But, in the case of heavy metals, the soil vs. solution for soil washing was determined as the optimal ratio of 1 : 5. Five consecutive soil washing with 0.5M of HCl and HNO3 solutions were performed. Results of experiments, in case of Pb was removed by target removal efficiency from soil on the twice washing. With in case of Zn was over on the first washing by target removal efficiency, but suggesting that twice consecutive soil washing is desirable as stability at field. Results of consecutive soil washing experiments, the removal efficiency maintained lower than 10 % after the 4th washing. From the results, demanding consecutive washing is not recommended. Results about the heavy metal contaminated soil washing experiments of the coastal landfill, in the case of HCl with more than 0.5 M of solution was performed at 1:5 of soil ratio vs. solution, 30 minutes of washing time and 2-3 consecutive soil washing. And in the case of HNO3 with 0.8 M of solution was performed various ratios of soil vs. washing solution, suggesting that 2-3 consecutive soil washing was reached to Pb and Zn target removal efficiency. Key words : landfill soil; washing solution; heavy metal contamination; soil remediation; soil washing; soil contamination

  11. Aqueous chemical wash compositions

    SciTech Connect

    Bannister, C.E.

    1987-07-21

    This patent describes an aqueous, substantially unfoamed chemical wash composition having properties making it suitable for use as a pre-flush in well cementing operations and/or for removal of drilling mud from a borehole at a temperature of from about 150/sup 0/F to about 270/sup 0/F, the wash a. being predominantly composed of water, b. containing an active surfactant component comprising a combination of (1) from about 0.1 to about 1.5 weight percent (total weight basis) of a water soluble anionic surfactant; (2) from about 0.1 to about 1.5 weight percent (total weight basis) of a nonionic surfactant; and (3) from about 0.05 to about 0.54 weight percent (total weight basis) of at least one water soluble amphoteric surfactant, and c. having dispersed therein a heterogeneous mixture of distinct particles comprising both a first particulate oil soluble resin which is friable and a second particulate oil soluble resin which is pliable and where the size of the friable resin particles ranges from about 0.5 to about 300 microns and the size of the pliable resin particles ranges from about 0.05 to about 30 microns. The amount of the friable-pliable resin mixture is sufficient to impart effective fluid loss control to the chemical wash composition.

  12. Washing Out the Competition

    NASA Technical Reports Server (NTRS)

    2001-01-01

    AJT Associates, Inc. (AJT) worked with NASA to develop a revolutionary ozone-based laundry system. AJT's TecH2Ozone(R) wash system presents its customers with an energy-efficient, cost-effective, and environmentally safe way to perform commercial laundering. TecH2Ozone significantly reduces the amount of water and chemical used as compared to traditional commercial laundry systems. This reduction has resulted in lower cost and shorter wash cycles. And due to the reduced use of chemicals, a significant portion of the rinse water is recycled back into the system for reuse. TecH2Ozone customers, such as hotels and other large commercial laundry facilities, have felt the benefits of this equipment. Because of the reduced cycle times, fewer washers are needed and there is a notable increase in the cleanliness of the laundry. The reduction in chemical residues is a boon to customers with allergies and those prone to skin irritation from chemicals retained in regular laundry. AJT Associates, Inc. (AJT) worked with NASA to develop a revolutionary ozone-based laundry system. AJT's TecH2Ozone(R) wash system presents its customers with an energy-efficient, cost-effective, and environmentally safe way to perform commercial laundering.

  13. Soil remediation using a coupled process: soil washing with surfactant followed by photo-Fenton oxidation.

    PubMed

    Villa, Ricardo D; Trovó, Alam G; Nogueira, Raquel F Pupo

    2010-02-15

    In the present work the use of a coupled process, soil washing and photo-Fenton oxidation, was investigated for remediation of a soil contaminated with p,p'-DDT (DDT) and p,p'-DDE (DDE), and a soil artificially contaminated with diesel. In the soil washing experiments, Triton X-100 (TX-100) aqueous solutions were used at different concentrations to obtain wastewaters with different compositions. Removal efficiencies of 66% (DDT), 80% (DDE) and 100% (diesel) were achieved for three sequential washings using a TX-100 solution strength equivalent to 12 times the effective critical micelle concentration of the surfactant (12 CMC(eff)). The wastewater obtained was then treated using a solar photo-Fenton process. After 6h irradiation, 99, 95 and 100% degradation efficiencies were achieved for DDT, DDE and diesel, respectively. In all experiments, the concentration of dissolved organic carbon decreased by at least 95%, indicating that residual concentration of contaminants and/or TX-100 in the wastewater was very low. The co-extraction of metals was also evaluated. Among the metals analyzed (Pb, Cr, Ni, Cu, Cd, Mn and Co), only Cr and Mn were detected in the wastewater at concentrations above the maximum value permitted by current Brazilian legislation. The effective removal of contaminants from soil by the TX-100 washing process, together with the high degradation efficiency of the solar photo-Fenton process, suggests that this procedure could be a useful option for soil remediation. PMID:19853992

  14. Effects of dilute substitutional solutes on interstitial carbon in ?-Fe: Interactions and associated carbon diffusion from first-principles calculations

    NASA Astrophysics Data System (ADS)

    Liu, Peitao; Xing, Weiwei; Cheng, Xiyue; Li, Dianzhong; Li, Yiyi; Chen, Xing-Qiu

    2014-07-01

    By means of first-principles calculations coupled with the kinetic Monte Carlo simulations, we have systematically investigated the effects of dilute substitutional solutes on the behaviors of carbon in ?-Fe. Our results uncover the following. (i) Without the Fe vacancy the interactions between most solutes and carbon are repulsive due to the strain relief, whereas Mn has a weak attractive interaction with its nearest-neighbor carbon due to the local ferromagnetic coupling effect. (ii) The presence of the Fe vacancy results in attractive interactions of all the solutes with carbon. In particular, the Mn-vacancy pair shows an exceptionally large binding energy of -0.81 eV with carbon. (iii) The alloying addition significantly impacts the atomic-scale concentration distributions and chemical potential of carbon in the Fe matrix. Among them, Mn and Cr increase the carbon chemical potential, whereas Al and Si reduce it. (iv) Within the dilute scale of the alloying solution, the solute concentration- and temperature-dependent carbon diffusivities demonstrate that Mn has a little impact on the carbon diffusion, whereas Cr (Al or Si) remarkably retards the carbon diffusion. Our results provide a certain implication for better understanding the experimental observations related with the carbon solubility limit, carbon microsegregation, and carbide precipitations in the ferritic steels.

  15. The regeneration of polluted activated carbon by radiation techniques

    NASA Astrophysics Data System (ADS)

    Minghong, Wu; Borong, Bao; Ruimin, Zhou; Jinliang, Zhu; Longxin, Hu

    1998-10-01

    In this paper, the regeneration of used activated carbon from monosodium glutamate factory was experimented using radiation and acid-alkali chemical cleaning method. Results showed that the activated carbon saturated with pollutants can be wash away easily by flushing with chemical solution prior irradiation. DSC was used to monitor the change of carbon adsorption

  16. Results Of Routine Strip Effluent Hold Tank, Decontaminated Salt Solution Hold Tank, Caustic Wash Tank And Caustic Storage Tank Samples From Modular Caustic-Side Solvent Extraction Unit During Macrobatch 6 Operations

    SciTech Connect

    Peters, T. B.

    2014-01-02

    Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), Caustic Wash Tank (CWT) and Caustic Storage Tank (CST) samples from the Interim Salt Disposition Project (ISDP) Salt Batch (“Macrobatch”) 6 have been analyzed for 238Pu, 90Sr, 137Cs, and by Inductively Coupled Plasma Emission Spectroscopy (ICPES). The Pu, Sr, and Cs results from the current Macrobatch 6 samples are similar to those from comparable samples in previous Macrobatch 5. In addition the SEHT and DSSHT heel samples (i.e. ‘preliminary’) have been analyzed and reported to meet NGS Demonstration Plan requirements. From a bulk chemical point of view, the ICPES results do not vary considerably between this and the previous samples. The titanium results in the DSSHT samples continue to indicate the presence of Ti, when the feed material does not have detectable levels. This most likely indicates that leaching of Ti from MST has increased in ARP at the higher free hydroxide concentrations in the current feed.

  17. Uranium (VI) adsorption on goethite and soil in carbonate solutions

    SciTech Connect

    Duff, M.C. [Los Alamos National Lab., NM (United States); Amrhein, C. [Univ. of California, Riverside, CA (United States)

    1996-09-01

    Elevated concentrations of U are found in agricultural drainage waters from the San Joaquin Valley, CA, which are often disposed of in evaporation basins that are frequented by waterfowl. To determine the factors that affect aqueous U concentrations in the basins, sorption experiments with U(VI) were performed at various CO{sub 2} partial pressures, dissolved Ca, Mg, and P concentrations, and carbonate alkalinities. Synthetic waters, comparable in inorganic constituents to irrigation and drainage waters, were prepared, spiked with 0.1 (soil) and 2 mg U(VI) L{sup -1} (synthetic goethite), and analyzed for U, P (when applicable), and major ions. Total chemical analyses were input into the computer program FITEQL to determine U(VI) speciation and generate U(VI) adsorption constants with the diffuse layer model (also referred to as the two-layer model). Maximum adsorption occurred in solutions with low carbonate alkalinities (<=3 mmol L{sup -1}), ionic strengths (<=0.03 M), Ca concentrations (<=4 mmol L{sup -1}), and P concentrations (<0.005 mmol L{sup -1} for soil). Study results suggest that elevated U concentration in the drainage waters are due to the speciation of dissolved U(VI) into negatively charged carbonate complexes. 29 refs., 5 figs., 7 tabs.

  18. Washing treatment of automotive shredder residue (ASR).

    PubMed

    Cossu, Raffaello; Lai, Tiziana

    2013-08-01

    Worldwide, the amount of end-of-life vehicles (ELVs) reaches 50 million units per year. Once the ELV has been processed, it may then be shredded and sorted to recover valuable metals that are recycled in iron and steelmaking processes. The residual fraction, called automotive shredder residue (ASR), represents 25% of the ELV and is usually landfilled. In order to deal with the leachable fraction of ASR that poses a potential threat to the environment, a washing treatment before landfilling was applied. To assess the potential for full-scale application of washing treatment, tests were carried out in different conditions (L/S = 3 and 5L/kgTS; t = 3 and 6 h). Moreover, to understand whether the grain size of waste could affect the washing efficiency, the treatment was applied to ground (<4 mm) and not-ground samples. The findings obtained revealed that, on average, washing treatment achieved removal rates of more than 60% for dissolved organic carbon (DOC), chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN). With regard to metals and chlorides, sulphates and fluoride leachable fraction, a removal efficiency of approximately 60% was obtained, as confirmed also by EC values. The comparison between the results for ground and not-ground samples did not highlight significant differences. PMID:23706987

  19. Laboratory testing in-tank sludge washing, summary letter report

    SciTech Connect

    Norton, M.V.; Torres-Ayala, F.

    1994-09-01

    In-tank washing is being considered as a means of pretreating high-level radioactive waste sludges, such as neutralized current acid waste (NCAW) sludge. For this process, the contents of the tank will be allowed to settle, and the supernatant solution will be decanted and removed. A dilute sodium hydroxide/sodium nitrite wash solution will be added to the settled sludge and the tank contents will be mixed with a mixer pump system to facilitate washing of the sludge. After thorough mixing, the mixer pumps will be shut off and the solids will be allowed to re-settle. After settling, the supernatant solution will be withdrawn from the tank, and the wash cycle will be repeated several times with fresh wash solution. Core sample data of double shell tank 241-AZ-101 indicate that settling of NCAW solids may be very slow. A complicating factor is that strong thermal currents are expected to be generated from heat produced by radionuclides in the sludge layer at the bottom of the tank. Additionally, there are concerns that during the settling period (i.e., while mixing pumps and air-lift re-circulators are shut off), the radionuclides may heat the residual interstitial water in the sludge to the extent that violent steam discharges (steam bumping) could occur. Finally, there are concerns that during the washing steps sludge settling may be hindered as a result of the reduced ionic strength of the wash solution. To overcome the postulated reduced settling rates during the second and third washing steps, the use of flocculants is being considered. To address the above concerns and uncertainties associated with in-tank washing, PNL has conducted laboratory testing with simulant tank waste to investigate settling rates, steam bump potential, and the need for and use of flocculating agents.

  20. Experimental fractionation of stable carbon isotopes during degassing of carbon dioxide and precipitation of calcite from aqueous solutions

    NASA Astrophysics Data System (ADS)

    Müller, K.; Winde, V.; Escher, P.; von Geldern, R.; Böttcher, M. E.

    2012-04-01

    Processes in the carbonate system of surface waters are in particular sensitive to variations of boundary conditions as, for instance, the partial pressure of carbon dioxide in the atmosphere and the aqueous solution. Examples range from streams, rivers, to coastal marine waters. The flux of carbon dioxide from continental flowing waters was recently included into calculations of the global carbon budget (Butman & Raymond, 2011, Nature Geo.). These solutions, are often supersaturated in carbon dioxide with respect to the atmosphere. The degassing of carbon dioxide is associated with a kinetically controlled fractionation of the stable carbon isotopes, which has to be considered in balancing water-air carbon dioxide fluxes. The degassing process additionally leads to the super-saturation of the aqueous solution with respect to calcium carbonate. Stable isotope fractionation is of particular value to identify and quantify processes at the water-gas phase interface and link these non-equilibrium processes to the formation mechanisms of calcite and the hydrodynamics of surface waters. Experiments were carried out with or without inert N2 gas flow to degas carbon dioxide from initially supersaturated solutions. Natural solutions used are from different stations of the Elbe estuary, the Jade Bay, the backbarrier tidal area of Spiekeroog Island, carbonate springs of Rügen Island, and the Baltic Sea coastline. Results are compared experiments using bottled mineral waters. By following the (physico) chemical changes in the solutions (pH, TA, Ca PHREEQC modeling) it was found, that two evolutionary stages can be differentiated. Reaction progress led to the preferential liberation of carbon dioxide containing the light carbon isotope, following a Rayleigh-type process. After an induction period, where only degassing of carbon dioxide took place, a second stage was observed where calcite began to form from the highly supersaturated solutions. In this stage the carbonate system of the solution was controlled by both, degassing and carbonate precipitation, still leading to an enrichment of the heavier carbon isotope in the residual DIC. The experimental results are evaluated for both periods, and the influence of salinity and pH is extracted. Acknowledgement: Parts of this study were supported by BMBF within the BIOACID project

  1. Polyelectrolyte and carbon nanotube multilayers made from ionic liquid solutions.

    PubMed

    Nakashima, Takuya; Zhu, Jian; Qin, Ming; Ho, Szushen; Kotov, Nicholas A

    2010-10-01

    The inevitable contact of substrates with water during the traditional practice of layer-by-layer assembly (LBL) creates problems for multiple potential applications of LBL films in electronics. To resolve this issue, we demonstrate here the possibility of a LBL process using ionic liquids (ILs), which potentially eliminates corrosion and hydration processes related to aqueous media and opens additional possibilities in structural control of LBL films. ILs are also considered to be one of the best "green" processing solvents, and hence, are advantageous in respect to traditional organic solvents. Poly(ethyleneimine) (PEI) and poly(sodium styrenesulfonate) (PSS) were dispersed in a hydrophilic IL and successfully deposited in the LBL fashion. To produce electroactive thin films with significance to electronics, a similar process was realized for PSS-modified single-walled carbon nanotubes (SWNT-PSS) and poly(vinyl alcohol) (PVA). Characterization of the coating using standard spectroscopy and microscopy techniques typical of the multilayer field indicated that there are both similarities and differences in the structure and properties of LBL films build from ILs and aqueous solutions. The films exhibited electrical conductivity of 10(2) S m(-1) with transparency as high as 98% for visible light, which is comparable to similar parameters for many carbon nanotube and graphene films prepared by both aqueous LBL and other methods. PMID:20931147

  2. Carbon Footprint of Telemedicine Solutions - Unexplored Opportunity for Reducing Carbon Emissions in the Health Sector

    PubMed Central

    Holmner, Åsa; Ebi, Kristie L.; Lazuardi, Lutfan; Nilsson, Maria

    2014-01-01

    Background The healthcare sector is a significant contributor to global carbon emissions, in part due to extensive travelling by patients and health workers. Objectives To evaluate the potential of telemedicine services based on videoconferencing technology to reduce travelling and thus carbon emissions in the healthcare sector. Methods A life cycle inventory was performed to evaluate the carbon reduction potential of telemedicine activities beyond a reduction in travel related emissions. The study included two rehabilitation units at Umeå University Hospital in Sweden. Carbon emissions generated during telemedicine appointments were compared with care-as-usual scenarios. Upper and lower bound emissions scenarios were created based on different teleconferencing solutions and thresholds for when telemedicine becomes favorable were estimated. Sensitivity analyses were performed to pinpoint the most important contributors to emissions for different set-ups and use cases. Results Replacing physical visits with telemedicine appointments resulted in a significant 40–70 times decrease in carbon emissions. Factors such as meeting duration, bandwidth and use rates influence emissions to various extents. According to the lower bound scenario, telemedicine becomes a greener choice at a distance of a few kilometers when the alternative is transport by car. Conclusions Telemedicine is a potent carbon reduction strategy in the health sector. But to contribute significantly to climate change mitigation, a paradigm shift might be required where telemedicine is regarded as an essential component of ordinary health care activities and not only considered to be a service to the few who lack access to care due to geography, isolation or other constraints. PMID:25188322

  3. Soil-washing technologies in Europe

    SciTech Connect

    Runge, H. [DETEC GmbH, Alzenau (Germany); Schmidt, D. [NUKEM Nuclear Technologies, Columbia, SC (United States)

    1996-12-31

    Soil near nuclear installations is sometimes found to be contaminated by radioactive elements. In addition, due to the increasing number of decommissioning projects, there is also an increasing need for the remediation of radioactive contaminated soil. Excavation of the contaminated soil can offer a direct remediation solution. Currently, it must be followed by some soil treatment because direct deposition in a nuclear repository is too expensive to be an economical solution. On-site as well as off-site decontamination of soil by soil washing has proved to be a very efficient and also an economical solution.

  4. Shear-thickening flow of suspensions of carbon nanofibers in aqueous PVA solutions

    Microsoft Academic Search

    Yasufumi Otsubo; Masahito Fujiwara; Masahiro Kouno; Kazuya Edamura

    2007-01-01

    The suspensions of carbon nanofibers in aqueous poly(vinyl alcohol) solutions were prepared in the presence of spherical carbon\\u000a black particles, and the steady-shear viscosity and dynamic viscoelasticity were measured for complex suspensions. Although\\u000a the single suspensions of carbon black are highly stable, the flocculation of carbon nanofibers is promoted by the addition\\u000a of carbon black particles. The complex suspensions show

  5. Effect of washing treatments on pesticide residues and antioxidant compounds in Yuja ( Citrus junos Sieb ex Tanaka)

    Microsoft Academic Search

    Jung-Min Sung; Ki-Hyun Kwon; Jong-Hoon Kim; Jin-Woong Jeong

    2011-01-01

    This study investigated the removal efficiency of pesticide residues and microorganisms, and changes of the amount of antioxidant\\u000a compounds on yuja (Citrus junos Sieb ex Tanaka) by various washing methods. The washing methods were mechanical washing (MW), mechanical washing after soaking\\u000a in SAcEW, strong acidic electrolyzed water (SAcEW+MW), and soaking detergent solution (DW), with a tap water washing (TW)\\u000a as

  6. Immunotoxicity of washing soda in a freshwater sponge of India.

    PubMed

    Mukherjee, Soumalya; Ray, Mitali; Ray, Sajal

    2015-03-01

    The natural habitat of sponge, Eunapius carteri faces an ecotoxicological threat of contamination by washing soda, a common household cleaning agent of India. Washing soda is chemically known as sodium carbonate and is reported to be toxic to aquatic organisms. Domestic effluent, drain water and various human activities in ponds and lakes have been identified as the major routes of washing soda contamination of water. Phagocytosis and generation of cytotoxic molecules are important immunological responses offered by the cells of sponges against environmental toxins and pathogens. Present study involves estimation of phagocytic response and generation of cytotoxic molecules like superoxide anion, nitric oxide and phenoloxidase in E. carteri under the environmentally realistic concentrations of washing soda. Sodium carbonate exposure resulted in a significant decrease in the phagocytic response of sponge cells under 4, 8, 16mg/l of the toxin for 96h and all experimental concentrations of the toxin for 192h. Washing soda exposure yielded an initial increase in the generation of the superoxide anion and nitric oxide followed by a significant decrease in generation of these cytotoxic agents. Sponge cell generated a high degree of phenoloxidase activity under the experimental exposure of 2, 4, 8, 16mg/l of sodium carbonate for 96 and 192h. Washing soda induced alteration of phagocytic and cytotoxic responses of E. carteri was indicative to an undesirable shift in their immune status leading to the possible crises of survival and propagation of sponges in their natural habitat. PMID:25497767

  7. Hand Washing in Emergency Situations

    E-print Network

    Schoessow, Courtney

    2005-09-30

    - nated. However, it is still important for you and your family to wash your hands often to avoid illness. When should you wash your hands? ? Before preparing or eating food ? After using the bathroom ? After changing diapers or cleaning a child who...

  8. Polyelectrolyte and carbon nanotube multilayers made from ionic liquid solutions

    NASA Astrophysics Data System (ADS)

    Nakashima, Takuya; Zhu, Jian; Qin, Ming; Ho, Szushen; Kotov, Nicholas A.

    2010-10-01

    The inevitable contact of substrates with water during the traditional practice of layer-by-layer assembly (LBL) creates problems for multiple potential applications of LBL films in electronics. To resolve this issue, we demonstrate here the possibility of a LBL process using ionic liquids (ILs), which potentially eliminates corrosion and hydration processes related to aqueous media and opens additional possibilities in structural control of LBL films. ILs are also considered to be one of the best ``green'' processing solvents, and hence, are advantageous in respect to traditional organic solvents. Poly(ethyleneimine) (PEI) and poly(sodium styrenesulfonate) (PSS) were dispersed in a hydrophilic IL and successfully deposited in the LBL fashion. To produce electroactive thin films with significance to electronics, a similar process was realized for PSS-modified single-walled carbon nanotubes (SWNT-PSS) and poly(vinyl alcohol) (PVA). Characterization of the coating using standard spectroscopy and microscopy techniques typical of the multilayer field indicated that there are both similarities and differences in the structure and properties of LBL films build from ILs and aqueous solutions. The films exhibited electrical conductivity of 102 S m-1 with transparency as high as 98% for visible light, which is comparable to similar parameters for many carbon nanotube and graphene films prepared by both aqueous LBL and other methods.The inevitable contact of substrates with water during the traditional practice of layer-by-layer assembly (LBL) creates problems for multiple potential applications of LBL films in electronics. To resolve this issue, we demonstrate here the possibility of a LBL process using ionic liquids (ILs), which potentially eliminates corrosion and hydration processes related to aqueous media and opens additional possibilities in structural control of LBL films. ILs are also considered to be one of the best ``green'' processing solvents, and hence, are advantageous in respect to traditional organic solvents. Poly(ethyleneimine) (PEI) and poly(sodium styrenesulfonate) (PSS) were dispersed in a hydrophilic IL and successfully deposited in the LBL fashion. To produce electroactive thin films with significance to electronics, a similar process was realized for PSS-modified single-walled carbon nanotubes (SWNT-PSS) and poly(vinyl alcohol) (PVA). Characterization of the coating using standard spectroscopy and microscopy techniques typical of the multilayer field indicated that there are both similarities and differences in the structure and properties of LBL films build from ILs and aqueous solutions. The films exhibited electrical conductivity of 102 S m-1 with transparency as high as 98% for visible light, which is comparable to similar parameters for many carbon nanotube and graphene films prepared by both aqueous LBL and other methods. Electronic supplementary information (ESI) available: Aggregation of PEI and PSS in [EMIm][EtSO4], detailed FTIR data, water-contact angle for (PEI/PSS)10 multilayers, and XPS survey spectra. See DOI: 10.1039/b9nr00333a

  9. Additive approach for inactivation of Escherichia coli O157:H7, Salmonella, and Shigella spp. on contaminated fresh fruits and vegetables using bacteriophage cocktail and produce wash.

    PubMed

    Magnone, Joshua P; Marek, Patrick J; Sulakvelidze, Alexander; Senecal, Andre G

    2013-08-01

    The incidence of foodborne outbreaks involving fresh produce is of worldwide concern. Lytic bacteriophage cocktails and a levulinic acid produce wash were investigated for their effectiveness against the foodborne pathogens Escherichia coli O157:H7, Shigella spp., and Salmonella on broccoli, cantaloupe, and strawberries. Inoculated samples were treated with bacteriophage cocktails (BC) before storage at 10°C for 24 h, a levulinic acid produce wash (PW) after storage at 10°C for 24 h, or a combination of the washes (BCPW) before and after storage. All three treatments were compared against a 200-ppm free available chlorine wash. Wash solutions were prepared using potable water and water with an increased organic content of 2.5 g/liter total dissolved solids and total organic carbon. BCPW was the most effective treatment, producing the highest log reductions in the pathogens. Produce treated with BCPW in potable water with a PW exposure time of 5 min resulted in the highest reduction of each pathogen for all samples tested. The type of produce and wash solution had significant effects on the efficacy of the individual treatments. The chlorine wash in water with higher organic content was the least effective treatment tested. An additive effect of BCPW was seen in water with higher organic content, resulting in greater than 4.0-log reductions in pathogens. Our findings indicate that the combination of antimicrobial BC with a commercial produce wash is a very effective method for treating produce contaminated with E. coli O157:H7, Shigella spp., and Salmonella even in the presence of high loads of organic matter. PMID:23905788

  10. Adsorption of malachite green from aqueous solution onto carbon prepared from Arundo donax root

    Microsoft Academic Search

    Jian Zhang; Yan Li; Chenglu Zhang; Yuming Jing

    2008-01-01

    Arundo donax root carbon (ADRC), a new adsorbent, was prepared from Arundo donax root by carbonization. The surface area of the adsorbent was determined 158m2\\/g by N2 adsorption isotherm. Batch adsorption experiments were carried out for the removal of malachite green (MG) from aqueous solution using ADRC as adsorbent. The effects of various parameters such as solution pH (3–10), carbon

  11. Results Of Routine Strip Effluent Hold Tank, Decontaminated Salt Solution Hold Tank, Caustic Wash Tank And Caustic Storage Tank Samples From Modular Caustic-Side Solvent Extraction Unit During Macrobatch 6 Operations

    SciTech Connect

    Peters, T. B.

    2013-10-01

    Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), Caustic Wash Tank (CWT) and Caustic Storage Tank (CST) samples from several of the ''microbatches'' of Integrated Salt Disposition Project (ISDP) Salt Batch (''Macrobatch'') 6 have been analyzed for {sup 238}Pu, {sup 90}Sr, {sup 137}Cs, and by Inductively Coupled Plasma Emission Spectroscopy (ICPES). The results from the current microbatch samples are similar to those from comparable samples in Macrobatch 5. From a bulk chemical point of view, the ICPES results do not vary considerably between this and the previous macrobatch. The titanium results in the DSSHT samples continue to indicate the presence of Ti, when the feed material does not have detectable levels. This most likely indicates that leaching of Ti from MST in ARP continues to occur. Both the CST and CWT samples indicate that the target Free OH value of 0.03 has been surpassed. While at this time there is no indication that this has caused an operational problem, the CST should be adjusted into specification. The {sup 137}Cs results from the SRNL as well as F/H lab data indicate a potential decline in cesium decontamination factor. Further samples will be carefully monitored to investigate this.

  12. Results Of Routine Strip Effluent Hold Tank, Decontaminated Salt Solution Hold Tank, And Caustic Wash Tank Samples From Modular Caustic-Side Solvent Extraction Unit During Macrobatch 4 Operations

    SciTech Connect

    Peters, T. B.; Fink, S. D.

    2012-10-25

    Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), and Caustic Wash Tank (CWT) samples from several of the ?microbatches? of Integrated Salt Disposition Project (ISDP) Salt Batch (?Macrobatch?) 4 have been analyzed for {sup 238}Pu, {sup 90}Sr, {sup 137}Cs, and by inductively-coupled plasma emission spectroscopy (ICPES). Furthermore, samples from the CWT have been analyzed by a variety of methods to investigate a decline in the decontamination factor (DF) of the cesium observed at MCU. The results indicate good decontamination performance within process design expectations. While the data set is sparse, the results of this set and the previous set of results for Macrobatch 3 samples indicate generally consistent operations. There is no indication of a disruption in plutonium and strontium removal. The average cesium DF and concentration factor (CF) for samples obtained from Macrobatch 4 are slightly lower than for Macrobatch 3, but still well within operating parameters. The DSSHT samples show continued presence of titanium, likely from leaching of the monosodium titanate in Actinide Removal Process (ARP).

  13. Prototype wash water renovation system integration with goverment-furnished wash fixture

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A total renovation concept for removing objectionable materials from spacecraft wash water to make the water reusable was developed. This concept included ferric chloride pretreatment to coagulate suspended solids such as soap and lint, pressure filtration, and carbon adsorption and ion exchange to remove trace dissolved organics and inorganic salts. A breadboard model which was developed to demonstrate the design adequacy of the various system components and the limits on system capacities and efficiencies.

  14. REMOVAL OF HYDROGEN SULFIDE, AMMONIA AND NITRITE IONS FROM WATER SOLUTIONS USING MODIFIED ACTIVE CARBONS

    Microsoft Academic Search

    T. LUPASCU; RAISA NASTAS; M. CIOBANU; TATIANA ARAPU; V. RUSU

    Modified active carbons were used for removal of hydrogen sulfide, ammonia and nitrite ions from water solutions. Obtained\\u000a results demonstrate that active carbon oxidized with H2O2 following impregnation with Co(II) possesses higher adsorption capacity for NH4\\u000a + compared with unimpregnated samples. It was established that active carbon obtained from nut shells has better oxidation\\u000a properties compared with active carbons obtained

  15. 7 CFR 58.429 - Washing machine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Washing machine. 58.429 Section 58.429 Agriculture...Equipment and Utensils § 58.429 Washing machine. When used, the washing machine for cheese cloths and bandages shall be...

  16. 7 CFR 58.429 - Washing machine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Washing machine. 58.429 Section 58.429 Agriculture...Equipment and Utensils § 58.429 Washing machine. When used, the washing machine for cheese cloths and bandages shall be...

  17. 7 CFR 58.429 - Washing machine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Washing machine. 58.429 Section 58.429 Agriculture...Equipment and Utensils § 58.429 Washing machine. When used, the washing machine for cheese cloths and bandages shall be...

  18. 7 CFR 58.429 - Washing machine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Washing machine. 58.429 Section 58.429 Agriculture...Equipment and Utensils § 58.429 Washing machine. When used, the washing machine for cheese cloths and bandages shall be...

  19. 7 CFR 58.429 - Washing machine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Washing machine. 58.429 Section 58.429 Agriculture...Equipment and Utensils § 58.429 Washing machine. When used, the washing machine for cheese cloths and bandages shall be...

  20. On the black carbon problem and its solutions

    NASA Astrophysics Data System (ADS)

    Jacobson, M. Z.

    2010-12-01

    Black carbon (BC) warms air temperatures in at least seven major ways: (a) directly absorbing downward solar radiation, (b) absorbing upward reflected solar radiation when it is situated above bright surfaces, such as snow, sea ice, and clouds, (c) absorbing some infrared radiation, (d) absorbing additional solar and infrared radiation upon obtaining a coating, (e) absorbing radiation multiply reflected within clouds when situated interstitially between cloud drops, (f) absorbing additional radiation when serving as CCN or scavenged inclusions within cloud drops, and (g) absorbing solar radiation when deposited on snow and sea ice, reducing the albedos of both. Modeling of the climate effects of BC requires treatment of all these processes in detail. In particular, treatment of BC absorption interstitially between cloud drops and from multiply-dispersed cloud drop BC inclusions must be treated simultaneously with treatment of cloud indirect effects to determine the net effects of BC on cloud properties. Here, results from several simulations of the effects of BC from fossil fuel and biofuel sources on global and regional climate and air pollution health are summarized. The simulations account for all the processes mentioned. Results are found to be statistically significant relative to chaotic variability in the climate system. Over time and in steady state, fossil-fuel soot plus biofuel soot are found to enhance warming more than methane. The sum of the soots causes less steady-state warming but more short term warming than does carbon dioxide. Thus eliminating soot emissions from both sources may be the fastest method of reducing rapid climate warming and possibly the only method of saving the Arctic ice. Eliminating such emissions may also reduce over 1.5 million deaths worldwide, particularly in developing countries. Short term mitigation options include the targeting of fossil-fuel and biofuel BC sources with particle traps, new stove technologies, and rural electrification. However, the real solution, to be implemented over a 20-40 year period is complete conversion of the combustion infrastructure to electricity and electrolytic hydrogen, where the electricity is all produced by near-zero emitting wind, water, and solar (WWS) based energy technologies. Such a conversion would reduce BC and greenhouse gases simultaneously with cooling aerosol particles. This would ramp down the presence of both warming and cooling agents, but still cause net reduction of global warming, while reducing devastating health impacts that are occurring from both warming and cooling aerosols.

  1. Selective removal of plutonium 238 from a canal sediment using a carbonate-chelant soil washing technology (ACT*DE*CON).

    PubMed

    Negri, M C; Swift, N A; Carfagno, D; Neff, R A; North, J

    1999-04-23

    The Mound laboratory site in Miamisburg, OH, a former plutonium processing facility, contains approximately 40000 yd(3) (30,580 m3) of plutonium- and thorium-contaminated soils and sediments at levels that require remediation. Existing applicable remediation technologies are unsatisfactory, because they are expensive and do not provide volume reduction. ACT*DE*CON is a chemical soil leaching technology for the treatment of soils that utilizes contaminant dissolution via dilute selective solutions to remove radionuclides. In bench-scale tests, process parameters were developed for the optimal treatment of the Miami Erie Canal soil at the Mound site, combining the maximum plutonium removal with an acceptable amount of soil dissolution and minimizing the costs of reagents. Parameters evaluated included soil to extractant mass ratio, temperature, rinse solution composition, kinetics, and the application of several dewatering aids. Plutonium removal rates of >95% were achieved, and the residual plutonium in the treated soil proved to be very immobile-confirming that the process had removed the most accessible species of the radionuclide. Currently being tested at Mound is an engineering scale-up that includes an attrition scrubber, a counter-current extractor, and a reverse osmosis system. Economic evaluations based on bench-scale results put the treatment cost at US$278/yd(3) (US$364/m3), compared to US$350/yd(3) (US$458/m3) for the 'box-and-bury' baseline alternative treatment system. PMID:10379033

  2. Hydrothermal Carbonization: a feasible solution to convert biomass to soil?

    NASA Astrophysics Data System (ADS)

    Tesch, Walter; Tesch, Petra; Pfeifer, Christoph

    2013-04-01

    The erosion of fertile soil is a severe problem arising right after peak oil (Myers 1996). That this issue is not only a problem of arid countries is shown by the fact that even the European Commission defined certain milestones to address the problem of soil erosion in Europe (European Commission 2011). The application of bio-char produced by torrefaction or pyrolysis for the remediation, revegetation and restoration of depleted soils started to gain momentum recently (Rillig 2010, Lehmann 2011, Beesley 2011). Hydrothermal carbonization (HTC) is a promising thermo-chemical process that can be applied to convert organic feedstock into fertile soil and water, two resources which are of high value in regions being vulnerable to erosion. The great advantage of HTC is that organic feedstock (e.g. organic waste) can be used without any special pretreatment (e.g. drying) and so far no restrictions have been found regarding the composition of the organic matter. By applying HTC the organic material is processed along a defined pathway in the Van Krevelen plot (Behrendt 2006). By stopping the process at an early stage a nutritious rich material can be obtained, which is known to be similar to terra preta. Considering that HTC-coal is rich in functional groups and can be derived from the process under "wet" conditions, it can be expected that it shall allow soil bacteria to settle more easily compared to the bio-char derived by torrefaction or pyrolysis. In addition, up to 10 tons process water per ton organic waste can be gained (Vorlop 2009). Thus, as organic waste, loss of fertile soil and water scarcity becomes a serious issue within the European Union, hydrothermal carbonization can provide a feasible solution to address these issues of our near future. The presentation reviews the different types of feedstock investigated for the HTC-Process so far and gives an overview on the current stage of development of this technology. References Beesley L., Moreno-Jiménez E., Gomez-Eyles J.L., Harris H., Robinson B., Sizmur T.: A review of biochars' potential role in the remediation, revegetation and restoration of contaminated soils. Environmental Pollution (159), p. 3269 - 3282, 2011. Behrendt F.: Direktverflüssigung von Biomasse - Reaktionsmechanismen und Produktverteilungen Institut für Energietechnik, Technische Universität Berlin Studie im Auftrag der Bundesanstalt für Landwirtschaft und Ernährung; Projektnummer 114-50-10-0337/05-B, 2006. European Commission: "Roadmap to a Resource Efficient Europe", COM(2011) 571. Lehmann J., Rillig M.C., Thies J., Masiello C.A., Hockaday W.C., Crowley D.: Biochar effects on soil biota - A review, Soil Biology & Biochemistry, p. 1-25, 2011. Myers Norman: "Environmental services of biodiversity", Proc. Natl. Acad. Sci. USA Vol 93, pp. 2764 - 2769, 1996. Rillig M.C., Wagner M., Salem M., Antunes P.M., George C., Ramke H.G., Titirici M.M., Antonietti M.: Material derived from hydrothermal carbonization: effects on plant growth and arbuscular mycorrhiza. Applied Soil Ecology (45), p. 238 - 242, 2010. Vorlop K.D., Schuchardt F., Prüße U.: Hydrothermale Carbonisierung Analyse und Ausblicke. FNR-Fachgespräch, Berlin, 2009.

  3. THE SOLAR NEBULA ON FIRE: A SOLUTION TO THE CARBON DEFICIT IN THE INNER SOLAR SYSTEM

    SciTech Connect

    Lee, Jeong-Eun [Department of Astronomy and Space Science, Astrophysical Research Center for the Structure and Evolution of the Cosmos, Sejong University, Seoul 143-747 (Korea, Republic of); Bergin, Edwin A. [Department of Astronomy, The University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Nomura, Hideko [Department of Astronomy, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)], E-mail: jelee@sejong.ac.kr, E-mail: ebergin@umich.edu, E-mail: nomura@kusastro.kyoto-u.ac.jp

    2010-02-10

    Despite a surface dominated by carbon-based life, the bulk composition of the Earth is dramatically carbon poor when compared to the material available at formation. Bulk carbon deficiency extends into the asteroid belt representing a fossil record of the conditions under which planets are born. The initial steps of planet formation involve the growth of primitive sub-micron silicate and carbon grains in the Solar Nebula. We present a solution wherein primordial carbon grains are preferentially destroyed by oxygen atoms ignited by heating due to stellar accretion at radii <5 AU. This solution can account for the bulk carbon deficiency in the Earth and meteorites, the compositional gradient within the asteroid belt, and for growing evidence for similar carbon deficiency in rocks surrounding other stars.

  4. Ceramic wash-coat for catalyst support

    DOEpatents

    Kulkarni, Anand A.; Subramanian, Ramesh; Sabol, Stephen M.

    2012-08-14

    A wash-coat (16) for use as a support for an active catalyst species (18) and a catalytic combustor component (10) incorporating such wash-coat. The wash-coat is a solid solution of alumina or alumina-based material (Al2O3-0-3 wt % La2O3) and a further oxide exhibiting a coefficient of thermal expansion that is lower than that exhibited by alumina. The further oxide may be silicon dioxide (2-30 wt % SiO2), zirconia silicate (2-30 wt % ZrSiO4), neodymium oxide (0-4 wt %), titania (Al2O3-3-40% TiO2) or alumina-based magnesium aluminate spinel (Al2O3-25 wt % MgO) in various embodiments. The active catalyst species may be palladium and a second metal in a concentration of 10-50% of the concentration of the palladium.

  5. Characterization of carbon nanotube thin films formed using electronic-grade carbon nanotube aqueous solutions

    NASA Astrophysics Data System (ADS)

    Han, Xuliang; Janzen, Daniel C.

    2008-01-01

    Carbon nanotubes (CNTs) are of great interests for a wide range of applications because of their unique structural, mechanical, electrical, optical, thermal, and chemical properties. Particularly, CNT thin films can be used as mechanically flexible, electrically conductive, and broadband optically transparent electrodes in various optoelectronic devices. However, one crucial obstacle to implementing CNT-based applications has been the unavailability of pure CNTs suitable for direct industrial use. The as-produced CNTs are very fluffy soot, and thus extremely difficult to be handled in the device fabrication process. Although CNTs can be grown directly on a substrate from the catalyst deposited on the substrate surface, the growing temperature is very high, typically > 900°C, which represents a big challenge to device fabrication and integration. Another issue is that the catalyst on the substrate surface must be removed without affecting the grown CNTs. In the raw CNT soot, there is always a considerable amount of impurities, including metallic particles from the catalyst and carbonaceous impurities from the chemical reaction by-products. Such impurities can greatly degrade the properties of CNT thin films. The production of electronic-grade CNT aqueous solutions, which contain only individually suspended pure CNTs without any kind of surfactant, is a critical milestone for implementing CNT-based applications. By using such solutions, pure CNT thin films of various densities can be formed through common solution-casting processes, such as spin coating, spray coating, micro-dispensing, and ink-jet printing. The properties of these pure CNT thin films will be discussed in this paper.

  6. Extraction of palladium from acidic solutions with the use of carbon adsorbents

    SciTech Connect

    O.N. Kononova; N.G. Goryaeva; N.B. Dostovalova; S.V. Kachin; A.G. Kholmogorov [Krasnoyarsk State University, Krasnoyarsk (Russian Federation)

    2007-08-15

    We studied the sorption of palladium(II) on LKAU-4, LKAU-7, and BAU carbon adsorbents from model hydrochloric acid solutions and the solutions of spent palladium-containing catalysts. It was found that sorbents based on charcoal (BAU) and anthracite (LKAU-4) were characterized by high sorption capacities for palladium. The kinetics of the saturation of carbon adsorbents with palladium(II) ions was studied, and it was found that more than 60% of the initial amount of Pd(II) was recovered in a 1-h contact of an adsorbent with a model solution. This value for the solutions of spent catalysts was higher than 35%.

  7. Metallocene/carbon hybrids prepared by a solution process for supercapacitor applications

    E-print Network

    Mao, Xianwen

    Efficient and scalable solution-based processes are not generally available to integrate well-studied pseudocapacitive materials (i.e., metal oxides and conducting polymers) with other components such as porous carbon, ...

  8. 27 CFR 19.328 - Wash water.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Wash water. 19.328 Section 19.328... Chemical By-Products § 19.328 Wash water. Water used in washing chemicals...remove spirits therefrom may be run into a wash tank or a distilling material...

  9. Anodic polarization behavior of low-carbon steel in concentrated sodium hydroxide and sodium nitrate solutions

    Microsoft Academic Search

    Karthik Subramanian; John Mickalonis

    2005-01-01

    High-level radioactive wastes, primarily consisting of concentrated sodium hydroxide (NaOH) and sodium nitrate (NaNO3) solutions, are stored in large underground storage tanks made of low-carbon steel. The anodic polarization behavior of low-carbon steel in concentrated solutions of 10M NaOH and various concentrations of NaNO3 (0.01–2.0M) was determined in order to predict the caustic stress corrosion cracking (CSCC) susceptibility of the

  10. Adsorption characteristics of 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solution on powdered activated carbon.

    PubMed

    Aksu, Z; Kabasakal, E

    2005-01-01

    The removal of 2,4-dichlorophenoxyacetic acid (2,4-D), one of the most commonly used phenoxy acid herbicides, from aqueous solution was studied by using acid-washed powdered activated carbon (PAC) as an adsorbent in a batch system. Adsorption equilibrium, kinetics, and thermodynamics were investigated as a function of initial pH, temperature, and initial 2,4-D concentration. Powdered activated carbon exhibited the highest 2,4-D uptake capacity of 333.3 mg g(-1) at 25 degrees C and an initial pH value of 2.0. Freundlich, Langmuir, and Redlich-Peterson isotherm models were used to express the equilibrium data of 2,4-D depending on temperature. Equilibrium data fitted very well to the Freundlich equilibrium model in the studied concentration range of 2,4-D at all the temperatures studied. Three simplified models including pseudo-first-order, pseudo-second-order, and saturation-type kinetic models were used to test the adsorption kinetics. It was shown that the adsorption of 2,4-D on PAC at 25, 35, and 45 degrees C could be best fitted by the saturation-type kinetic model with film and intraparticle diffusions being the essential rate-controlling steps. The activation energy of adsorption (EA) was determined as--1.69 kJ mole(-1). Using the thermodynamic equilibrium coefficients obtained at different temperatures, the thermodynamic constants of adsorption (deltaG degrees, deltaH degrees, and deltaS degrees) were also evaluated. PMID:16047879

  11. Enhanced sludge washing evaluation plan

    SciTech Connect

    Jensen, R.D.

    1994-09-01

    The Tank Waste Remediation System (TWRS) Program mission is to store, treat, and immobilize highly radioactive Hanford Site waste (current and future tank waste and the strontium/cesium capsules) in an environmentally sound, safe, and cost-effective manner. The scope of the TWRS Waste Pretreatment Program is to treat tank waste and separate that waste into HLW and LLW fractions and provide additional treatment as required to feed LLW and HLW immobilization facilities. Enhanced sludge washing was chosen as the baseline process for separating Hanford tank waste sludge. Section 1.0 briefly discusses the purpose of the evaluation plan and provides the background that led to the choice of enhanced sludge washing as the baseline process. Section 2.0 provides a brief summary of the evaluation plan details. Section 3.0 discusses, in some detail, the technical work planned to support the evaluation of enhanced sludge washing. Section 4.0 briefly discusses the potential important of policy issues to the evaluation. Section 5.0 discusses the methodology to be used in the evaluation process. Section 6.0 summarizes the milestones that have been defined to complete the enhanced sludge washing evaluation and provides a summary schedule to evaluate the performance of enhanced sludge washing. References are identified in Section 7.0, and additional schedule and milestone information is provided in the appendices.

  12. Organic Solvent Dispersions of Single-Walled Carbon Nanotubes: Toward Solutions of Pristine Nanotubes

    E-print Network

    Ben-Yakar, Adela

    LETTERS Organic Solvent Dispersions of Single-Walled Carbon Nanotubes: Toward Solutions of Pristine Nanotubes Kevin D. Ausman, Richard Piner, Oleg Lourie, and Rodney S. Ruoff* Department of Physics/dispersion of pristine single-walled carbon nanotubes (SWCNTs). Five solvents, all featuring high electron pair donicity

  13. Ultrafiltration of Aqueous Solutions of Bromocresol Purple in the Presence of Dispersed Carbon

    Microsoft Academic Search

    S. V. Kozlov

    2003-01-01

    Ultrafiltration of solutions of Bromocresol Purple on a UFM-50M membrane in the presence of dispersed carbon was studied. The variation of the flow rate through unit surface area of the membrane and of the dye retention factor with time was traced. The influence exerted on the ultrafiltration by dye adsorption on dispersed carbon and by formation of a dynamic membrane

  14. A reactor model for gold elution from activated carbon with caustic cyanide solution

    Microsoft Academic Search

    T. M. Sun; W. T. Yen

    1995-01-01

    A model for the Zadra elution process was developed based on pore diffusion inside the carbon particles, the dispersed plug flow in the elution column, and the gold desorption from carbon as a first order reaction. A set of process description equations was obtained. Numerical solutions for the system equations are given using the finite difference method, and the stability

  15. Visible-light photoconversion of carbon dioxide into organic acids in an aqueous solution of carbon dots.

    PubMed

    Sahu, Sushant; Liu, Yamin; Wang, Ping; Bunker, Christopher E; Fernando, K A Shiral; Lewis, William K; Guliants, Elena A; Yang, Fan; Wang, Jinping; Sun, Ya-Ping

    2014-07-22

    Carbon "quantum" dots (or carbon dots) have emerged as a new class of optical nanomaterials. Beyond the widely reported bright fluorescence emissions in carbon dots, their excellent photoinduced redox properties that resemble those found in conventional semiconductor nanostructures are equally valuable, with photon-electron conversion applications from photovoltaics to CO2 photocatalytic reduction. In this work we used gold-doped carbon dots from controlled synthesis as water-soluble catalysts for a closer examination of the visible-light photoconversion of CO2 into small organic acids, including acetic acid (for which the reduction requires many more electrons than that for formic acid) and, more interestingly, for the significantly enhanced photoconversion with higher CO2 pressures over an aqueous solution of the photocatalysts. The results demonstrate the nanoscale semiconductor-equivalent nature of carbon dots, with excellent potential in energy conversion applications. PMID:24972094

  16. Basic solutions to carbon/carbon oxidation: Science and technology. Annual technical report, 15 April 1993-14 April 1994

    SciTech Connect

    Harrison, T.R.; Chung, T.; Radovic, L.; Pantano, C.; Thrower, P.A.

    1994-05-13

    The attached report addresses the first year of a program aimed at developing basic solutions to carbon/carbon composite oxidation. In particular, one primary thrust is the development of boron containing carbons through pyrolysis of boron containing polymers. Additionally, a basic understanding of the oxidation mechanisms in carbons and boron containing carbons is being sought. Several new boron containing precursors have been synthesized, which can be converted to B/C materials after pyrolysis. In particular, polyacrylonitrile (PAN) has been copolymerized with a boron-containing monomer (vinylcatecholborane.) Approximately 68% of the original boron is retained after pyrolysis yielding a product with 3.4% boron. 1,4-polybutadiene (PBD) has been hydroborated to contain large amounts of boron. Model compounds have been used to prepare polydiyne with considerable amounts of boron. In the latter two cases, direct analysis for % boron is not yet available. Preliminary TGA data suggests that PBD containing boron results in a more stable structure.

  17. The wash-off of reactive dyes on cellulosic fibres. Part 1: Dichlorotriazinyl dyes on cotton

    Microsoft Academic Search

    S. M. Burkinshaw; A. Anthoulias

    1996-01-01

    Three dichlorotriazinyl reactive dyes were applied, at 2% omf, to woven cotton and the dyeings then washed-off using tap water, sodium bicarbonate and six commercial surfactants, the latter in both the presence and absence of sodium carbonate. The duration and temperature of wash-off, as well as the concentration of sodium bicarbonate used, were varied and the effects of these variables

  18. Effect of niobium on massive transformation in ultra low carbon steels: a solute drag treatment

    Microsoft Academic Search

    M. Suehiro; Z.-K. Liu; J. Ågren

    1996-01-01

    The effect of Nb on the ? ? ? transformation in ultra low carbon steels is examined experimentally and theoretically. It is shown that there are two modes of the massive transformation. One of them is heavily influenced by the solute drag effect of Nb. This is confirmed by a calculation based on a new model for treating the solute

  19. GENERATION OF SOIL SOLUTION ACID NEUTRALIZING CAPACITY BY ADDITION OF DISSOLVED INORGANIC CARBON

    EPA Science Inventory

    A Spodosol B horizon(base saturation of 5.4%) collected at the Watershed Manipulation Project site at Lead Mountain, ME, was used to examine soil solution chemistry in response to increasing solution levels of dissolved inorganic carbon (DIC). cid-neutralizing capacity (ANC), det...

  20. Mineralisation of coloured aqueous solutions by ozonation in the presence of activated carbon

    Microsoft Academic Search

    Patrícia C. C. Faria; José J. M. Órfão; Manuel Fernando R. Pereira

    2005-01-01

    The degradation of organic matter in coloured solutions of different classes of dyes by ozonation in the presence of activated carbon is investigated. The kinetics of the decolourisation and mineralisation of three different dyes solutions (CI Acid Blue 113, CI Reactive Red 241 and CI Basic Red 14) were studied in a laboratory scale reactor by three different processes: adsorption

  1. Metastable Equilibrium Solubility Behavior of Carbonated Apatites in the Presence of Solution Fluoride

    Microsoft Academic Search

    Hong Zhuang; Arif A. Baig; Jeffrey L. Fox; Zeren Wang; Shane J. Colby; Anil Chhettry; William I. Higuchi

    2000-01-01

    The aims of the present investigation were to assess the applicability of the metastable equilibrium solubility (MES) concept for the carbonated apatites (CAPs) over a range of pH and a wide range of solution fluoride concentrations and to examine the hypothesis that, in the presence of solution fluoride, a surface complex with the stoichiometry of fluorapatite (FAP) governs the MES

  2. Pyrite oxidation in carbonate-buffered solution: 2. Rate control by oxide coatings

    Microsoft Academic Search

    R. V. Nicholson; R. W. Gillham; E. J. Reardon

    1990-01-01

    The kinetic behavior of pyrite oxidation in the laboratory was studied over a period of about 10,000 hours in reactors through which a carbonate-buffered solution and air (20% Oâ) flowed continuously. Three grain size fractions were monitored. The concentration of sulfate and the mass of the effluent solution were measured periodically to calculate oxidation rates. The results indicate that the

  3. Na?-functionalized carbon quantum dots: a new draw solute in forward osmosis for seawater desalination.

    PubMed

    Guo, Chun Xian; Zhao, Dieling; Zhao, Qipeng; Wang, Peng; Lu, Xianmao

    2014-07-14

    A new type of biocompatible draw solute, Na(+)-functionalized carbon quantum dots (Na_CQDs) with ultra-small size and rich ionic species, in forward osmosis (FO) is developed for seawater desalination. The aqueous dispersion of Na_CQDs demonstrates a high osmotic pressure, which allows high FO water flux and negligible reverse solute permeation. PMID:24870226

  4. A shift in designing cage-washing operations.

    PubMed

    Zynda, Jeffrey R

    2015-03-20

    Support systems for animal research facilities are often complex and resource-intensive operations whose successful design and implementation require substantial experience. The cage-washing center is at the heart of these support spaces and is not only one of the largest spaces found in an animal facility but also one of the greatest consumers of resources, in terms of both utilities and human labor. Certain methodologies and systems for cage-wash operations have become 'go-to' solutions, but alternative approaches have the potential to reduce utility consumption and human labor. The author's firm analyzed cage-washing operations at an academic institution with the goal of reducing consumption of resources, both human labor and utilities such as water, steam and electricity. Here he describes the analysis and design process as a case study and shows that substantial savings can be achieved by using alternative systems in cage-washing systems. He recommends that cage-washing operations can be optimized by thoroughly investigating the anticipated cage-washing throughput and then thoughtfully selecting the most efficient means to handle that workload. PMID:25793681

  5. Ecological Engineering promotes Carbon Reduction Solutions for a Sustainable Planet

    Microsoft Academic Search

    Stephen Bedford Clark

    2009-01-01

    Due to un-prescedented; social, industrial and human reproductive growth, our global society is rapidly approaching peak development, coupling with climate change factors and accelerating Earths current 'melt cycle'. Our challenge is to do more with less; to question the 'way' it has always been done; to develop innovative low carbon engineering tools; to design and mimic natural eco-systems and to

  6. Carbon monoxide … the silent killer with an audible solution

    Microsoft Academic Search

    Edward P Krenzelok; Ronald Roth; Robert Full

    1996-01-01

    Carbon monoxide (CO) is responsible for more poisoning fatalities each year than any other toxic agent. The often insidious nature of the symptom progression and its ability to imitate many common illnesses may result in the failure to diagnose a potentially fatal outcome. CO detectors equipped with an audible alarm can alert potential victims of CO poisoning before toxic sequelae

  7. Investigation of texturization for crystalline silicon solar cells with sodium carbonate solutions

    Microsoft Academic Search

    Y Nishimoto; K Namba

    2000-01-01

    We investigate a new texturization technique for crystalline silicon solar cells with sodium carbonate (Na2CO3) solutions. We show the dependence of the hemispherical surface reflectance on solution temperature, the etching time and the Na2CO3 concentration. Furthermore, we investigate what element in Na2CO3 solution influences the texturing for reducing the texturing time. As a result of experiments, we find it possible

  8. Influence of Cu electroplating solutions on boron carbon nitride (BCN) film

    Microsoft Academic Search

    Hidemitsu Aoki; Makoto Hara; Takuro Masuzumi; Motaharu K. Mazumder; Naoki Ooi; Daisuke Watanabe; Chiharu Kimura; Takashi Sugino

    2009-01-01

    Cu electroplating is required for the fabrication of Cu\\/low-k interconnections. The permeation of a plating solution into low-k films during Cu electroplating is a serious challenge for 45-nm nodes and more complex devices. We investigated the influence of Cu electroplating solutions on boron carbon nitride (BCN) as a low-k film. After dipping it into a Cu electroplating solution that contained

  9. Electronic separation of dispersed carbon nanotubes in solution by Lorentz forces

    Microsoft Academic Search

    Charishma Subbaiah; Joshua Wood; Joseph Lyding

    2011-01-01

    Use of single-walled carbon nanotubes (SWNTs) in industry compatible device applications requires top-down control of SWNT electronic type. Therefore, we develop a technique for SWNT electronic separation, increasing the relative distribution of metallic SWNTs in solution by a magnetically induced Lorentz force. We take solutions of SWNTs in n-methylpyrrolidone and sonicate them, making a disperse solution on which we apply

  10. Regeneration of hexamminecobalt(II) catalyzed by activated carbon treated with KOH solutions

    Microsoft Academic Search

    Jing-yi Cheng; Lin Yang; Li Dong; Xiang-li Long; Wei-kang Yuan

    2011-01-01

    The combined elimination of NO and SO2 can be realized by hexamminecobalt(II) solution which is formed by adding soluble cobalt(II) salt into the aqueous ammonia solution. Activated carbon is used as a catalyst to regenerate hexamminecobalt(II), Co(NH3)62+, so that NO removal efficiency can be maintained at a high level for a long time. In this study, KOH solution has been

  11. Evaluation of solution-processable carbon-based electrodes for all-carbon solar cells.

    PubMed

    Ramuz, Marc P; Vosgueritchian, Michael; Wei, Peng; Wang, Chenggong; Gao, Yongli; Wu, Yingpeng; Chen, Yongsheng; Bao, Zhenan

    2012-11-27

    Carbon allotropes possess unique and interesting physical, chemical, and electronic properties that make them attractive for next-generation electronic devices and solar cells. In this report, we describe our efforts into the fabrication of the first reported all-carbon solar cell in which all components (the anode, active layer, and cathode) are carbon based. First, we evaluate the active layer, on standard electrodes, which is composed of a bilayer of polymer sorted semiconducting single-walled carbon nanotubes and C(60). This carbon-based active layer with a standard indium tin oxide anode and metallic cathode has a maximum power conversion efficiency of 0.46% under AM1.5 Sun illumination. Next, we describe our efforts in replacing the electrodes with carbon-based electrodes, to demonstrate the first all-carbon solar cell, and discuss the remaining challenges associated with this process. PMID:23113673

  12. WASH-1400: quantifying the uncertainties

    SciTech Connect

    Erdmann, R.C.; Leverenz, F.L. Jr.; Lellouche, G.S.

    1981-06-01

    The purpose of this paper is to focus on the limitations of the WASH-1400 analysis in estimating the risk from light water reactors (LWRs). This assessment attempts to modify the quantification of the uncertainty in and estimate of risk as presented by the RSS (reactor safety study). 8 refs.

  13. WASH1400: quantifying the uncertainties

    Microsoft Academic Search

    R. C. Erdmann; F. L. Jr. Leverenz; G. S. Lellouche

    1981-01-01

    The purpose of this paper is to focus on the limitations of the WASH-1400 analysis in estimating the risk from light water reactors (LWRs). This assessment attempts to modify the quantification of the uncertainty in and estimate of risk as presented by the RSS (reactor safety study). 8 refs.

  14. Abdominopelvic washings: A comprehensive review

    PubMed Central

    Rodriguez, Erika F.; Monaco, Sara E.; Khalbuss, Walid; Austin, R. Marshall; Pantanowitz, Liron

    2013-01-01

    Intraperitoneal spread may occur with gynecological epithelial neoplasms, as well as with non-gynecological malignancies, which may result in serosal involvement with or without concomitant effusion. Therefore, washings in patients with abdominopelvic tumors represent important specimens for cytologic examination. They are primarily utilized for staging ovarian cancers, although their role has decreased in staging of endometrial and cervical carcinoma. Abdominopelvic washings can be positive in a variety of pathologic conditions, including benign conditions, borderline neoplastic tumors, locally invasive tumors, or distant metastases. In a subset of cases, washings can be diagnostically challenging due to the presence of co-existing benign cells (e.g., mesothelial hyperplasia, endosalpingiosis, or endometriosis), lesions in which there is only minimal atypia (e.g., serous borderline tumors) or scant atypical cells, and the rarity of specific tumor types (e.g., mesothelioma). Ancillary studies including immunocytochemistry and fluorescence in situ hybridization may be required in difficult cases to resolve the diagnosis. This article provides a comprehensive and contemporary review of abdominopelvic washings in the evaluation of gynecologic and non-gynecologic tumors, including primary peritoneal and mesothelial entities. PMID:23858317

  15. Comparison of alternative washing systems for heliostats

    NASA Astrophysics Data System (ADS)

    Kerstein, A.

    1981-04-01

    Two methods are proposed for washing heliostat mirrors in a solar central receiver facility. One method involves truck mounted washing mechanisms continuously traversing the heliostat field, washing mirrors sequentially on a fixed schedule. The other concept involves a washing unit affixed to each heliostat, permitting near simultaneous washing of all heliostats on demand. The former, scheduled washing system has the advantage of lower capital costs, while the latter, responsive system has more operational flexibility. Cost benefit evaluation of the two systems, taking into account the random nature of rainfall patterns and soiling processes, indicates that the scheduled system is preferable.

  16. A basket for washing benthological samples

    USGS Publications Warehouse

    Selgeby, James H.

    1971-01-01

    Since benthological samples collected with dredges are usually too large to be preserved in toto, a washing method must be employed to reduce the sample volume without losing or damaging the organisms. Traditionally, the sample is washed in a sieve until the volume is small enough for convenient handling or preservation. Most washing procedures are time-consuming and laborious. To save time in washing samples, a washing 'basket' was designed which accomadates a Ponar dredge. The only additional equipment needed to employ the washing basket effectively is a pump that delivers about 8 gallons of water per minute.

  17. Alkaline solution absorption of carbon dioxide method and apparatus

    DOEpatents

    Hobbs, D.T.

    1991-01-01

    Disclosed is a method for measuring the concentration of hydroxides (or pH) in alkaline solutions, using the tendency of hydroxides to adsorb CO{sub 2}. The method comprises passing CO{sub 2} over the surface of an alkaline solution in a remote tank before and after measurements of the CO{sub 2} concentration. Comparison of the measurements yields the adsorption fraction from which the hydroxide concentration can be calculated using a correlation of hydroxide or pH to adsorption fraction. A schematic is given of a process system according to a preferred embodiment of the invention. 2 figs.

  18. Electrochemical formation of hydroxide for enhancing carbon dioxide and acid gas uptake by a solution

    DOEpatents

    Rau, Gregory Hudson (Castro Valley, CA)

    2012-05-15

    A system is described for forming metal hydroxide from a metal carbonate utilizing a water electrolysis cell having an acid-producing anode and a hydroxyl-producing cathode immersed in a water solution of sufficient ionic content to allow an electric current to pass between the hydroxyl-producing cathode and the acid-producing anode. A metal carbonate, in particular water-insoluble calcium carbonate or magnesium carbonate, is placed in close proximity to the acid-producing anode. A direct current electrical voltage is provided across the acid-producing anode and the hydroxyl-producing cathode sufficient to generate acid at the acid-producing anode and hydroxyl ions at the hydroxyl-producing cathode. The acid dissolves at least part of the metal carbonate into metal and carbonate ions allowing the metal ions to travel toward the hydroxyl-producing cathode and to combine with the hydroxyl ions to form the metal hydroxide. The carbonate ions travel toward the acid-producing anode and form carbonic acid and/or water and carbon dioxide. Among other uses, the metal hydroxide formed can be employed to absorb acid gases such as carbon dioxide from a gas mixture. The invention can also generate hydrogen and oxidative gases such as oxygen or chlorine.

  19. Towards a Long-Term Solution to Carbon Dioxide Storage

    Microsoft Academic Search

    Kamiel Gabriel; Huawei Han

    2006-01-01

    The growing threat of global warming caused by the burning of fossil fuels has led scientists to explore solutions such as underground injection of CO2. Possible alternatives for CO2 storage include the oceans, deep saline reservoirs and depleted oil and gas reservoirs. One of the key issues to be addressed with regard to underground reservoir storage is CO2 loss from

  20. Hydrothermal fluxes of solutes, carbon, and heat to Himalayan rivers

    Microsoft Academic Search

    Matthew Jared Evans

    2003-01-01

    Hot springs flow along the base of the Himalayan front in the Narayani river basin of central Nepal. The springs flow near the Main Central Thrust (MCT), in a zone characterized by active uplift and high incision and erosion rates. Water-rock interaction at depth results in hydrothermal fluids with high solute loads. Himalayan rivers flowing through the zones of geothermal

  1. Dioxin removal from contaminated soils by ethanol washing.

    PubMed

    Jonsson, Sofia; Lind, Henrik; Lundstedt, Staffan; Haglund, Peter; Tysklind, Mats

    2010-07-15

    The aim of this study was to investigate the potential utility of ethanol washing for remediating soils contaminated with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), as a cost-efficient alternative to conventional remediation methods of PCDD/F-contaminated soils. Initially, screening experiments were performed with a two-level full factorial design to examine the effects of temperature, extraction time and ethanol concentration on the removal efficiency. The screening experiments showed that the ethanol concentration was the most important parameter. In addition, repeated washing cycles considerably improved the results. Ethanol washing conditions were then selected (10 wash cycles with 75% ethanol at 60 degrees C), and applied to four soils with different soil characteristics and contamination levels to test the robustness of the selected method. Treatment efficiencies of 81% and 85% were obtained for a lightly contaminated sandy-silty soil and a highly contaminated clay soil rich in graphite particles, respectively. Even higher treatment efficiencies (> or = 97%) were obtained for two other highly contaminated soils, one of which contained high amounts of organic matter. PCDD/Fs were found to both dissolve in the solvent and migrate into it as species adsorbed to particles. The relative contributions of these mechanisms and the overall efficiency of the removal seem to depend on contaminant concentration, the types of carbon in the soil matrix and the particle size distribution. The study shows that ethanol washing has effective remediation potential for a variety of PCDD/F-contaminated soils. PMID:20399556

  2. Methods of pretreating comminuted cellulosic material with carbonate-containing solutions

    DOEpatents

    Francis, Raymond

    2012-11-06

    Methods of pretreating comminuted cellulosic material with an acidic solution and then a carbonate-containing solution to produce a pretreated cellulosic material are provided. The pretreated material may then be further treated in a pulping process, for example, a soda-anthraquinone pulping process, to produce a cellulose pulp. The pretreatment solutions may be extracted from the pretreated cellulose material and selectively re-used, for example, with acid or alkali addition, for the pretreatment solutions. The resulting cellulose pulp is characterized by having reduced lignin content and increased yield compared to prior art treatment processes.

  3. The effect of contaminant aging upon soil washing removal efficiencies for lead contaminated soils

    SciTech Connect

    Cline, S.R. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Reed, B.E.; Moore, R.E. [West Virginia Univ., Morgantown, WV (United States)

    1994-10-01

    The objective of this research was to investigate lead removal efficiencies from various soils using a variety of washing solutions. Most soil types have a strong affinity for lead. Thus, it is plausible to expect washing solutions that are capable of removing lead could also remove other divalent heavy metals. Four soil samples from the eastern US were collected and characterized for this study. The study soils were then spiked to approximate lead concentrations of 1,000 and 10,000 mg Pb/kg soil. The efficiencies of six washing solutions in removing lead from the contaminated soils were then investigated via lab-scale batch washing experiments. Unlike current field-scale soil washing practices, all particle size fractions were washed and recovered in these experiments. (Solutions investigated include: tap water, HCl, EDTA, HNO{sub 3}, CH{sub 3}COOH, and CaCl{sub 2}.) In order to examine the effect of aging upon soil washing efficiencies, some of the spiked soils were washed a second time after an aging period of nearly 2 years.

  4. Adsorption of nickel(II) from aqueous solution onto activated carbon prepared from almond husk

    Microsoft Academic Search

    Halil Hasar

    2003-01-01

    Activated carbon was prepared from almond husk by activating without (MAC-I) and with (MAC-II) H2SO4 at different temperatures. The ability of the activated carbon to remove nickel(II) ions from aqueous solutions by adsorption has been investigated under several conditions such as pH, carbonisation temperature of husk, initial concentration of metal ions, contact time, and adsorbent concentration. Optimal conditions were pH

  5. Evolution of pH and chemical composition of pore solution in carbonated concrete

    Microsoft Academic Search

    Qi Pu; Linhua Jiang; Jinxia Xu; Hongqiang Chu; Yi Xu; Yan Zhang

    An investigation of carbonation in concrete, the pH and chemical composition change of the pore solution in concrete with different degrees of carbonation, was presented. The concrete samples were manufactured using ordinary portland cement and fly ash with dimension of 100mm diameter by 3mm in height, and six different mix proportions. The concrete samples were exposed to the environment (CO2

  6. Stability of carbon nanowalls against chemical attack with acid solutions

    NASA Astrophysics Data System (ADS)

    Vizireanu, Sorin; Dinescu, Gheorghe; Nistor, Leona Cristina; Baibarac, Mihaela; Ruxanda, Grigore; Stancu, Mihaela; Ciuparu, Dragos

    2013-01-01

    In this paper we report on the stability of CNW layers, synthesized by a radiofrequency plasma jet, against the chemical attack with different acid solutions (sulfuric acid, nitric acid, hydrochloric acid, and hydrofluoric acid). We present the changes of the morphology and structure of the CNW caused by the post-growth chemical treatments. We demonstrate that self-sustaining and transferable CNW layers can be obtained, by chemically dissolving the substrates, while the initial characteristics of the material are well preserved.

  7. Mathematical Model of Carbon Dioxide Absorption into Mixed Aqueous Solutions

    Microsoft Academic Search

    Patricia Mores; Nicolas Scenna; Sergio Mussati

    2009-01-01

    In this paper, a mathematical model of CO2 chemical absorption system using MDEA (MethylDiEthanolAmine) and PZ (Piperazine) aqueous solutions is investigated. Precisely, the complex reactive absorption behavior is modeled by an NLP mathematical model. The resulting mathematical model is implemented in GAMS and CONOPT is used as NLP solver. The proposed model will allow to optimize the operating conditions to

  8. 21 CFR 1250.87 - Wash water.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 2010-04-01 false Wash water. 1250.87 Section 1250.87 Food...Facilities and Conditions on Vessels § 1250.87 Wash water. Where systems installed on vessels for wash water, as defined in § 1250.3(n),...

  9. The wash-off of reactive dyes on cellulosic fibres part 2. Monochlorotriazinyl dyes on cotton

    Microsoft Academic Search

    S. M. Burkinshaw; D. Katsarelias

    1997-01-01

    One monochlorotriazinyl and two bis-monochlorotriazinyl dyes were applied to cotton fabric at 1, 2 and 4 % omf and the dyeings then washed-off using tap water, sodium carbonate and five commercial surfactants, the latter in both the presence and absence of sodium carbonate. The concentration of sodium carbonate was varied and its effects on both the extent of dye removal

  10. Activity and stability of immobilized carbonic anhydrase for promoting CO 2 absorption into a carbonate solution for post-combustion CO 2 capture

    Microsoft Academic Search

    Shihan Zhang; Zhaohui Zhang; Yongqi Lu; Massoud Rostam-Abadi; Andrew Jones

    2011-01-01

    An Integrated Vacuum Carbonate Absorption Process (IVCAP) currently under development could significantly reduce the energy consumed when capturing CO2 from the flue gases of coal-fired power plants. The biocatalyst carbonic anhydrase (CA) has been found to effectively promote the absorption of CO2 into the potassium carbonate solution that would be used in the IVCAP. Two CA enzymes were immobilized onto

  11. Solution and shock-induced exsolution of argon in vitreous carbon

    NASA Technical Reports Server (NTRS)

    Gazis, Carey; Ahrens, Thomas J.

    1991-01-01

    To add to the knowledge of noble gas solution and exsolution in carbonaceus material, experiments were performed on vitreous carbon. Ar-rich vitreous carbon samples were prepared under vapor-saturated conditions using argon as the pressurizing medium. Solubility data were obtained for temperatures of 773 to 973 K and pressures of 250 to 1500 bars. Up to 7 wt pct Ar was dissolved in the carbon. The solubility data were compared to a thermodynamic model of argon atoms dissolving into a fixed population of 'holes' in the carbon. Two variations of the model yielded estimates of the enthalpy of solution of Ar in vitreous carbon equal to about -4700 cal/mole. Preliminary shock experiments showed that 28 percent of the total argon was released by driving 4 GPa shocks into the argon-rich carbon. It was demonstrated that shock-induced argon loss is not simply caused by the impact-induced diminution of grain size. The present value of shock pressure required for partial impact devolatilization of Ar from carbon is below the range (5-30 GPa) at which H2O is released from phyllosilicates.

  12. Adsorption of Phenol and Basic Dye on Carbon Nanotubes\\/Carbon Fabric Composites from Aqueous Solution

    Microsoft Academic Search

    Jung-Pin Wang; Hsi-Chi Yang; Chien-Te Hsieh

    2010-01-01

    The liquid-phase adsorption of phenol and dye (basic violet 10) onto carbon nanotube (CNT)-activated carbon fabric (ACF) composites, prepared by a catalytic chemical vapor deposition (CCVD) approach, has been investigated. The CCVD technique enables the decoration of CNTs on microscaled ACFs, creating a hierarchy CNT-ACF composite. The as-grown nanotubes were found to have a tortuous shape and to be several

  13. Adsorption of Furfural from Aqueous Solution onto Activated Carbon: Kinetic, Equilibrium and Thermodynamic Study

    Microsoft Academic Search

    Ashwani Kumar Sahu; Vimal Chandra Srivastava; Indra Deo Mall; Dilip H. Lataye

    2008-01-01

    The present study aims to evaluate the influence of various experimental parameters viz. initial pH (pH0), adsorbent dose, contact time, initial concentration and temperature on the adsorptive removal of furfural from aqueous solution by commercial grade activated carbon (ACC). Optimum conditions for furfural removal were found to be pH0 ? 5.9, adsorbent dose ? 10 g\\/l of solution and equilibrium time

  14. Adsorption of cesium (I) from aqueous solution using oxidized multiwall carbon nanotubes

    Microsoft Academic Search

    R. Yavari; Y. D. Huang; S. J. Ahmadi

    2011-01-01

    Multiwall carbon nanotubes (MWCNTs) were modified by nitric acid solution and then used to study the adsorption of cesium\\u000a from aqueous solution using a batch technique under ambient conditions. As produced and oxidized MWCNTs were characterized\\u000a by nitrogen adsorption\\/desorption, Boehm’s titration method and Fourier transform infrared spectroscopy. The physical properties\\u000a of MWCNTs such as functional groups, total number of acid

  15. Surface modification of carbon nanotubes for enhancing BTEX adsorption from aqueous solutions

    Microsoft Academic Search

    Chungsying Lu; Fengsheng Su; Suhkai Hu

    2008-01-01

    Carbon nanotubes (CNTs) were fabricated by the catalytic chemical vapor deposition method and oxidized by HCl, H2SO4, HNO3 and NaOCl solutions for enhancing benzene, toluene, ethylbenzene and p-xylene (BTEX) adsorption in an aqueous solution. The surface nature of CNTs was changed after the H2SO4, HNO3 and NaOCl oxidation, which makes CNTs that adsorb more BTEX. The NaOCl-oxidized CNTs show the

  16. Electrochemical and vibrational properties of single-walled carbon nanotubes in hydrochloric acid solutions

    Microsoft Academic Search

    S. Lefrant; M. Baibarac; I. Baltog; T. Velula; J. Y. Mevellec; O. Chauvet

    2005-01-01

    Raman spectroscopy and cyclic voltammetry (CV) are used for the investigation of the oxidation–reduction processes of single-wall carbon nanotubes (SWNTs) films in an HCl 0.5 M solution. In the potential ranges (+100; +800) and (0; +1500) mV vs. saturated calomel electrode (SCE), the oxidation–reduction reactions of SWNT films, in both aqueous and semi-aqueous HCl 0.5M solutions, are reversible and irreversible,

  17. Activity of Cu-activated carbon fiber catalyst in wet oxidation of ammonia solution

    Microsoft Academic Search

    Chang-Mao Hung

    2009-01-01

    Aqueous solutions of 200–1000mg\\/L of ammonia were oxidized in a trickle-bed reactor using Cu-activated carbon fiber (ACF) catalysts, which were prepared by incipient wet impregnation with aqueous solutions of copper nitrate that was deposited on ACF substrates. The results reveal that the conversion of ammonia by wet oxidation in the presence of Cu-ACF catalysts was a function of the metal

  18. Comparative alkali washing of simulated radioactive sludge

    SciTech Connect

    Fugate, G.A.; Ensor, D.D. [Tennessee Technological Univ., Cookeville, TN (United States); Egan, B.Z. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    The treatment of large volumes of radioactive sludge generated from uranium and plutonium recovery processes is a pressing problem in the environmental restoration currently planned at various U.S. Department of Energy sites. This sludge, commonly stored in underground tanks, is mainly in the form of metal oxides or precipitated metal hydroxides and the bulk of this material is nonradioactive. One method being developed to pretreat this waste takes advantage of the amphoteric character of aluminum and other nonradioactive elements. Previous studies have reported on the dissolution of eleven elements from simulated sludge using NaOH solutions up to 6M. This work provides a comparative study using KOH. The effectiveness of the alkali washing as a treatment method to reduce the bulk of radioactive sludge requiring long term isolation will be discussed.

  19. TANK 4 CHARACTERIZATION, SETTLING, AND WASHING STUDIES

    SciTech Connect

    Bannochie, C.; Pareizs, J.; Click, D.; Zamecnik, J.

    2009-09-29

    A sample of PUREX sludge from Tank 4 was characterized, and subsequently combined with a Tank 51 sample (Tank 51-E1) received following Al dissolution, but prior to a supernate decant by the Tank Farm, to perform a settling and washing study to support Sludge Batch 6 preparation. The sludge source for the majority of the Tank 51-E1 sample is Tank 12 HM sludge. The Tank 51-E1 sample was decanted by SRNL prior to use in the settling and washing study. The Tank 4 sample was analyzed for chemical composition including noble metals. The characterization of the Tank 51-E1 sample, used here in combination with the Tank 4 sample, was reported previously. SRNL analyses on Tank 4 were requested by Liquid Waste Engineering (LWE) via Technical Task Request (TTR) HLE-TTR-2009-103. The sample preparation work is governed by Task Technical and Quality Assurance Plan (TTQAP), and analyses were controlled by an Analytical Study Plan and modifications received via customer communications. Additional scope included a request for a settling study of decanted Tank 51-E1 and a blend of decanted Tank 51-E1 and Tank 4, as well as a washing study to look into the fate of undissolved sulfur observed during the Tank 4 characterization. The chemistry of the Tank 4 sample was modeled with OLI Systems, Inc. StreamAnalyzer to determine the likelihood that sulfate could exist in this sample as insoluble Burkeite (2Na{sub 2}SO{sub 4} {center_dot} Na{sub 2}CO{sub 3}). The OLI model was also used to predict the composition of the blended tank materials for the washing study. The following conclusions were drawn from the Tank 4 analytical results reported here: (1) Any projected blend of Tank 4 and the current Tank 51 contents will produce a SB6 composition that is lower in Ca and U than the current SB5 composition being processed by DWPF. (2) Unwashed Tank 4 has a relatively large initial S concentration of 3.68 wt% on a total solids basis, and approximately 10% of the total S is present as an insoluble or undissolved form. (3) There is 19% more S than can be accounted for by IC sulfate measurement. This additional soluble S is detected by ICP-AES analysis of the supernate. (4) Total supernate and slurry sulfur by ICP-AES should be monitored during washing in addition to supernate sulfate in order to avoid under estimating the amount of sulfur species removed or remaining in the supernate. (5) OLI simulation calculations show that the presence of undissolved Burkeite in the Tank 4 sample is reasonable, assuming a small difference in the Na concentration that is well within the analytical uncertainties of the reported value. The following conclusions were drawn from the blend studies of Tank 4 and decanted Tank 51-E1: (1) The addition of Tank 4 slurry to a decanted Tank 51-E1 sample significantly improved the degree and time for settling. (2) The addition of Tank 4 slurry to a decanted Tank 51-E1 sample significantly improved the plastic viscosity and yield stress. (3) The SRNL washing test, where nearly all of the wash solution was decanted from the solids, indicates that approximately 96% or more of the total S was removed from the blend in these tests, and the removal of the sulfur tracks closely with that of Na. Insoluble (undissolved) S remaining in the washed sludge was calculated from an estimate of the final slurry liquid fraction, the S result in the slurry digestion, and the S in the final decant (which was very close to the method detection limit). Based on this calculated result, about 4% of the initial total S remained after these washes; this amount is equivalent to about 18% of the initially undissolved S.

  20. Carbon monoxide ... the silent killer with an audible solution.

    PubMed

    Krenzelok, E P; Roth, R; Full, R

    1996-09-01

    Carbon monoxide (CO) is responsible for more poisoning fatalities each year than any other toxic agent. The often insidious nature of the symptom progression and its ability to imitate many common illnesses may result in the failure to diagnose a potentially fatal outcome. CO detectors equipped with an audible alarm can alert potential victims of CO poisoning before toxic sequelae develop. A study was conducted in which all calls to 911 concerning a CO detector in alarm or regarding possible CO poisoning were investigated by a paramedic crew; 101 possible CO exposures were investigated. CO detectors with audible alarms were the genesis of 59.4% of the calls. Detectable CO levels were found in 69.3% of the investigations, and 80% of the homes with detectors had verifiable CO concentrations. The mean CO concentration in homes with detectors was 18.6 ppm, compared with 96.6 ppm when no detector was available; 63.4% of the victims with no alarm were symptomatic, compared with 13.3% of victims with alarms. CO detectors with audible alarms were effective in alerting the potential victims of CO poisoning to its presence. Persons with CO detectors were less likely to become symptomatic from a CO exposure than those who did not have CO detectors. PMID:8765117

  1. Synthesis of Nanostructured Carbon through Ionothermal Carbonization of Common Organic Solvents and Solutions.

    PubMed

    Chang, Yuanqin; Antonietti, Markus; Fellinger, Tim-Patrick

    2015-04-27

    A combination of ionothermal synthesis and hot-injection techniques leads to novel nanocarbons made from organic solvents. Controlled addition of commonly used organic solvents into a hot ZnCl2 melt gives rise to spherical, sheetlike, and branched nanofibrous carbon nanoparticles with surprisingly high carbon efficiency. When heteroatom-containing solvents were used, the doping levels reach up to 14?wt.?% nitrogen and 13?wt.?% sulfur. Materials with high surface areas and large pore volumes of solvent carbons as high as 1666?m(2) ?g(-1) and 2.80?cm(3) ?g(-1) in addition to CO2 adsorption capacities of 4.13?mmol?g(-1) at 273?K and 1?bar can be obtained. The new method works not only for pure carbon materials, but was also extended for the synthesis of carbon/inorganic nanocomposites. ZnS@C, Ni@C, and Co@C were successfully prepared with this straightforward procedure. The obtained Ni@C nanocomposites perform well in the electrocatalytic water oxidation, comparable with commercial noble-metal catalysts. PMID:25740456

  2. Carbon-13 NMR characterization of actinyl(VI) carbonate complexes in aqueous solution

    SciTech Connect

    Clark, D.L.; Hobart, D.E.; Palmer, P.D. [Los Alamos National Lab., NM (United States); Sullivan, J.C. [Argonne National Lab., IL (United States); Stout, B.E. [Cincinnati Univ., OH (United States). Dept. of Chemistry

    1992-07-01

    The uranyl(VI) carbonate system has been re-examined using {sup 13}C NMR of 99.9% {sup 13}C-enriched U{sup VI}O{sub 2} ({sup 13}CO{sub 3}){sub 3}{sup 4{minus}} in millimolar concentrations. By careful control of carbonate ion concentration, we have confirmed the existence of the trimer, and observed dynamic equilibrium between the monomer and the timer. In addition, the ligand exchange reaction between free and coordinated carbonate on Pu{sup VI}O{sub 2}({sup 13}CO{sub 3}){sub 3}{sup 4{minus}} and Am{sup VI}O{sub 2}({sup 13}CO{sub 3}){sub 3}{sup 4{minus}} systems has been examined by variable temperature {sup 13}C NMR line-broadening techniques {sup 13}C NMR line-broadening techniques. A modified Carr-Purcell-Meiboom-Gill NMR pulse sequence was written to allow for experimental determination of ligand exchange parameters for paramagnetic actinide complexes. Preliminary Eyring analysis has provided activation parameters of {Delta}G{sup {double_dagger}}{sub 295} = 56 kJ/M, {Delta}H{sup {double_dagger}} = 38 kJ/M, and {Delta}S{sup {double_dagger}} = {minus}60 J/M-K for the plutonyl triscarbonate system, suggesting an associative transition state for the plutonyl (VI) carbonate complex self-exchange reaction. Experiments for determination of the activation parameters for the americium (VI) carbonate system are in progress.

  3. Carbon-13 NMR characterization of actinyl(VI) carbonate complexes in aqueous solution

    SciTech Connect

    Clark, D.L.; Hobart, D.E.; Palmer, P.D. (Los Alamos National Lab., NM (United States)); Sullivan, J.C. (Argonne National Lab., IL (United States)); Stout, B.E. (Cincinnati Univ., OH (United States). Dept. of Chemistry)

    1992-01-01

    The uranyl(VI) carbonate system has been re-examined using {sup 13}C NMR of 99.9% {sup 13}C-enriched U{sup VI}O{sub 2} ({sup 13}CO{sub 3}){sub 3}{sup 4{minus}} in millimolar concentrations. By careful control of carbonate ion concentration, we have confirmed the existence of the trimer, and observed dynamic equilibrium between the monomer and the timer. In addition, the ligand exchange reaction between free and coordinated carbonate on Pu{sup VI}O{sub 2}({sup 13}CO{sub 3}){sub 3}{sup 4{minus}} and Am{sup VI}O{sub 2}({sup 13}CO{sub 3}){sub 3}{sup 4{minus}} systems has been examined by variable temperature {sup 13}C NMR line-broadening techniques {sup 13}C NMR line-broadening techniques. A modified Carr-Purcell-Meiboom-Gill NMR pulse sequence was written to allow for experimental determination of ligand exchange parameters for paramagnetic actinide complexes. Preliminary Eyring analysis has provided activation parameters of {Delta}G{sup {double dagger}}{sub 295} = 56 kJ/M, {Delta}H{sup {double dagger}} = 38 kJ/M, and {Delta}S{sup {double dagger}} = {minus}60 J/M-K for the plutonyl triscarbonate system, suggesting an associative transition state for the plutonyl (VI) carbonate complex self-exchange reaction. Experiments for determination of the activation parameters for the americium (VI) carbonate system are in progress.

  4. Dispersion of Multi?walled Carbon Nanotubes in Aqueous Pluronic F127 Solutions for Biological Applications

    Microsoft Academic Search

    Gianni Ciofani; Vittoria Raffa; Virginia Pensabene; Arianna Menciassi; Paolo Dario

    2009-01-01

    Because mass?produced carbon nanotubes (CNTs) are strongly aggregated and highly hydrophobic, processes to make them water soluble are required for biological applications. Suspensions in surfactant solutions are often employed. Among these, Pluronic F127 appear to be highly biocompatible if used at low concentrations. Starting from these results, this work involves a systematic study to clarify the dispersion behaviour of CNTs

  5. Radiolysis of Bicarbonate and Carbonate Aqueous Solutions: Product Analysis and Simulation of Radiolytic Processes

    SciTech Connect

    Cai Zhongli; Li Xifeng; Katsumura, Yosuke; Urabe, Osamu [University of Tokyo (Japan)

    2001-11-15

    An understanding of the radiation-induced effects in groundwater is essential to evaluate the safe geological disposal of spent fuel. In groundwater, the bicarbonate ion is the predominant and common anion; this work investigated radiation-induced chemical reactions of (bi)carbonate aqueous solutions with steady-state irradiation and pulse radiolysis methods. Aqueous solutions of sodium (bi)carbonate as high as 50 mmol.dm{sup -3} were used. The formation of formate, oxalate, and H{sub 2}O{sub 2} were measured under different conditions. A complete set of reaction steps and reliable kinetic data for the radiolysis of (bi)carbonate aqueous solutions at ionic strength close to the groundwater were proposed. Kinetic calculations were completed based on the proposed reaction steps and the kinetic data obtained in the present work. The results from the calculation are in good agreement with the experimental results. With these proposed reaction steps and kinetic data, computer simulation can be performed to predict the yield of radiolytic products of (bi)carbonate aqueous solutions as a function of irradiation time and used to evaluate the safety of geological disposal options of spent fuel.

  6. Degradation of dye solution by an activated carbon fiber electrode electrolysis system

    Microsoft Academic Search

    Zhemin Shen; Wenhua Wang; Jinping Jia; Jianchang Ye; Xue Feng; An Peng

    2001-01-01

    Degradation of 29 dyes by means of an activated carbon fiber (ACF) electrode electrolysis system was performed successfully. Almost all dye solutions tested were decolorized effectively in this ACF electrolysis process. Internal relationships between treatment mechanisms and chemical composition of the dye have been discussed in this paper. Generally, it is shown that higher solubility leads to greater degradation in

  7. Room temperature synthesis of protonated layered titanate sheets using peroxo titanium carbonate complex solution.

    PubMed

    Sutradhar, Narottam; Sinhamahapatra, Apurba; Pahari, Sandip Kumar; Bajaj, Hari C; Panda, Asit Baran

    2011-07-21

    We report the synthesis of peroxo titanium carbonate complex solution as a novel water-soluble precursor for the direct synthesis of layered protonated titanate at room temperature. The synthesized titanates showed excellent removal capacity for Pb(2+) and methylene blue. Based on experimental observations, a probable mechanism for the formation of protonated layered dititanate sheets is also discussed. PMID:21655555

  8. Sorption of metal ions from multicomponent aqueous solutions by activated carbons produced from waste

    SciTech Connect

    Tikhonova, L.P.; Goba, V.E.; Kovtun, M.F.; Tarasenko, Y.A.; Khavryuchenko, V.D.; Lyubchik, S.B.; Boiko, A.N. [National Academy of Science Ukraine, Kiev (Ukraine). Institute of Coal Chemistry

    2008-08-15

    Activated carbons produced by thermal treatment of a mixture of sunflower husks, low-grade coal, and refinery waste were studied as adsorbents of transition ion metals from aqueous solutions of various compositions. The optimal conditions and the mechanism of sorption, as well as the structure of the sorbents, were studied.

  9. INVESTIGATION OF LEACHING OF THE SLUDGE OF TUVAKOBALT PLANT USING THE AMMONIUM CARBONATE SOLUTION

    Microsoft Academic Search

    E. N. Timoshenko; SB RAS

    2009-01-01

    Involvement of wastes of Tuvakobalt plant into processing will allow one to recover valuable com- ponents from them: cobalt, nickel, copper etc., and at the same to abandon the wastes as a focus of the regional environmental pollution. We chose the ammonium carbonate method to transfer nonferrous metals from sludge into solution; the advantage of this method is its high

  10. Spectrophotometric measurement of total inorganic carbon in aqueous solutions using a liquid core waveguide

    Microsoft Academic Search

    R. H. Byrne; Xuewu Liu; E. A. Kaltenbacher; Karen Sell

    2002-01-01

    This work describes spectrophotometric procedures for direct measurements of total inorganic carbon in aqueous solutions. The procedures used for these measurements involve CO2 equilibration across the permeable wall of a Teflon AF-2400 liquid core waveguide. The waveguide acts as both an equilibration membrane and an optical cell in which spectrophotometric pH measurements, obtained via measurements of absorbance ratios, are used

  11. Oxidation of activated carbon with aqueous solution of sodium dichloroisocyanurate: Effect on ammonia adsorption

    Microsoft Academic Search

    M. Molina-Sabio; M. Gonçalves; F. Rodríguez-Reinoso

    2011-01-01

    An activated carbon has been oxidized with 1–10wt% aqueous solutions of sodium dichlororisocyanurate (DCI) to introduce oxygen and chlorine surface groups by chemisorption; the formation of chlorine surface groups is important when the concentration of DCI is high, the modification of the microporosity being small. The range of stability of the groups is wide, from groups decomposing at high temperature

  12. Rate Constants for Reactions of Aliphatic Carbon-Centered Radicals in Aqueous Solution

    Microsoft Academic Search

    Pedatsur Neta; Jan Grodkowski; Alberta B. Ross

    1996-01-01

    Absolute rate constants for reactions of aliphatic carbon-centered radicals in aqueous solutions have been compiled and evaluated from the literature. Rate constants are included for reactions of radicals with inorganic and organic compounds and for decay by radical–radical reactions. The radicals were generated by radiolysis, photolysis, or other techniques, and their rate constants were determined generally by kinetic spectrophotometry. The

  13. Anion influence in lead removal from aqueous solution by deposition onto a vitreous carbon electrode

    Microsoft Academic Search

    G. Carreño; E. Sosa; I. González; C. Ponce-de-León; N. Batina; M. T. Oropeza

    1999-01-01

    We investigated the electrolytic removal of Pb(II) from aqueous solutions containing different electrolytes (nitrate, chloride or sulfate), by electrolysis onto reticulated vitreous carbon electrode (RVC). The efficiency of the electrolytic process of lead removal was found to be a function of electrolyte composition. The chloride containing electrolyte, provided the highest efficiency of lead removal, while removing Pb(II) from the sulfate

  14. Solution to Urban Traffic Problem Based on Low-Carbon Development

    Microsoft Academic Search

    Zhang Yao; Cui Jinrong

    2010-01-01

    Low-carbon development will not only provide a solution to urban traffic problems, but also generate other effects, which are energy saving, emission reduction and industrial structure adjustment. These effects are of great significance as to atmospheric environment improvement and national economic development. Therefore, we must take actions, in aspects of acknowledge, urban planning, the factors of traffic supply and demand

  15. Wastewater washing screens out solids

    SciTech Connect

    Mitchell, D.G. [Hycor Corp., Lake Bluff, IL (United States)

    1994-09-01

    Screening, as practiced by most municipal wastewater treatment plants, involves the manual or mechanical separation of all undesirable solids that flow into the sewer system. This consists of putresible or rotting material and inert solids such as paper, food, leaves, plastics, rubber, rocks, glass, metal and cigarette butts. These constituents, if not removed, clog downstream equipment and put a heavy load on aeration basins, dissolved air flotation equipment and digesters. Screenings washing is just entering the U.S. market with numerous benefits including increased efficiency, economics, safer work environment, and the ability to meet more stringent regulations.

  16. Free Energetics of Carbon Nanotube Association in Pure and Aqueous Ionic Solutions

    PubMed Central

    Ou, Shuching; Patel, Sandeep; Bauer, Brad A.

    2012-01-01

    Carbon nanotubes are a promising platform across a broad spectrum of applications ranging from separations technology, drug delivery, to bio(electronic) sensors. Proper dispersion of carbon nanotube materials is important to retaining the electronic properties of nanotubes. Experimentally it has been shown that salts can regulate the dispersing properties of CNTs in aqueous system with surfactants (J. Am. Chem. Soc., 2009, 131:1144–1153); details of the physico-chemical mechanisms underlying such effects continue to be explored. We address the effects of inorganic monovalent salts (NaCl and NaI) on dispersion stability of carbon nanotubes. We perform all-atom molecular dynamics simulations using non-polarizable interaction models to compute the potential of mean force between two (10,10) single-walled carbon nanotubes (SWNTs) in the presence of NaCl/NaI and compare to the potential of mean force between SWNTs in pure water. Addition of salts enhances stability of the contact state between two SWNT’s on the order of 4 kcal/mole. The ion-specific spatial distribution of different halide anions gives rise to starkly different contributions to the free energy stability of nanotubes in the contact state. Iodide anion directly stabilizes the contact state to a much greater extent than chloride anion. The enhanced stability arises from the locally repulsive forces imposed on nanotubes by the surface-segregated iodide anion. Within the timescale of our simulations, both NaI and NaCl solutions stabilize the contact state by equivalent amounts. The marginally higher stability for contact state in salt solutions recapitulates results for small hydrophobic solutes in NaCl solutions (Athawale et al, J. Phys. Chem. B., 112, 5661. 2008) as well as single walled carbon nanotubes in NaCl and CaCl2 aqueous solutions. PMID:22780909

  17. OPTIMIZATION OF THE WASH-OFF METHOD FOR MEASURING AEROSOL CONCENTRATIONS

    EPA Science Inventory

    Using the fluorescence-washing technique, oleic acid particles tagged with uranine were extracted and analyzed fluorometrically. The possible sources of errors in the technique were evaluated in this study. First, the sensitivity of uranine fluorescence in different solutions ...

  18. EBR-II Primary Tank Wash-Water Alternatives Evaluation

    SciTech Connect

    Demmer, R. L.; Heintzelman, J. B.; Merservey, R. H.; Squires, L. N.

    2008-05-01

    The EBR-II reactor at Idaho National Laboratory was a liquid sodium metal cooled reactor that operated for 30 years. It was shut down in 1994; the fuel was removed by 1996; and the bulk of sodium metal coolant was removed from the reactor by 2001. Approximately 1100 kg of residual sodium remained in the primary system after draining the bulk sodium. To stabilize the remaining sodium, both the primary and secondary systems were treated with a purge of moist carbon dioxide. Most of the residual sodium reacted with the carbon dioxide and water vapor to form a passivation layer of primarily sodium bicarbonate. The passivation treatment was stopped in 2005 and the primary system is maintained under a blanket of dry carbon dioxide. Approximately 670 kg of sodium metal remains in the primary system in locations that were inaccessible to passivation treatment or in pools of sodium that were too deep for complete penetration of the passivation treatment. The EBR-II reactor was permitted by the Idaho Department of Environmental Quality (DEQ) in 2002 under a RCRA permit that requires removal of all remaining sodium in the primary and secondary systems by 2022. The proposed baseline closure method would remove the large components from the primary tank, fill the primary system with water, react the remaining sodium with the water and dissolve the reaction products in the wash water. This method would generate a minimum of 100,000 gallons of caustic, liquid, low level radioactive, hazardous waste water that must be disposed of in a permitted facility. On February 19-20, 2008, a workshop was held in Idaho Falls, Idaho, to look at alternatives that could meet the RCRA permit clean closure requirements and minimize the quantity of hazardous waste generated by the cleanup process. The workshop convened a panel of national and international sodium cleanup specialists, subject matter experts from the INL, and the EBR-II Wash Water Project team that organized the workshop. The workshop was conducted by a trained facilitator using Value Engineering techniques to elicit the most technically sound solutions from the workshop participants. The path forward includes developing the OBA into a well engineered solution for achieving RCRA clean closure of the EBR-II Primary Reactor Tank system. Several high level tasks are also part of the path forward such as reassigning responsibility of the cleanup project to a dedicated project team that is funded by the DOE Office of Environmental Management, and making it a priority so that adequate funding is available to complete the project. Based on the experience of the sodium cleanup specialists, negotiations with the DEQ will be necessary to determine a risk-based de minimus quantity for acceptable amount of sodium that can be left in the reactor systems after cleanup has been completed.

  19. Approximate Solutions for a Self-Folding Problem of Carbon Nanotubes

    SciTech Connect

    Y Mikata

    2006-08-22

    This paper treats approximate solutions for a self-folding problem of carbon nanotubes. It has been observed in the molecular dynamics calculations [1] that a carbon nanotube with a large aspect ratio can self-fold due to van der Waals force between the parts of the same carbon nanotube. The main issue in the self-folding problem is to determine the minimum threshold length of the carbon nanotube at which it becomes possible for the carbon nanotube to self-fold due to the van der Waals force. An approximate mathematical model based on the force method is constructed for the self-folding problem of carbon nanotubes, and it is solved exactly as an elastica problem using elliptic functions. Additionally, three other mathematical models are constructed based on the energy method. As a particular example, the lower and upper estimates for the critical threshold (minimum) length are determined based on both methods for the (5,5) armchair carbon nanotube.

  20. Electrochemical formation of hydroxide for enhancing carbon dioxide and acid gas uptake by a solution

    DOEpatents

    Rau, Gregory Hudson

    2014-07-01

    A system for forming metal hydroxide from a metal carbonate utilizes a water electrolysis cell having an acid-producing anode and a hydroxyl-producing cathode immersed in a water solution of sufficient ionic content to allow an electric current to pass between the hydroxyl-producing cathode and the acid-producing anode. A metal carbonate is placed in close proximity to the acid-producing anode. A direct current electrical voltage is provided across the acid-producing anode and the hydroxyl-producing cathode sufficient to generate acid at the acid-producing anode and hydroxyl ions at the hydroxyl-producing cathode. The acid dissolves at least part of the metal carbonate into metal and carbonate ions allowing the metal ions to travel toward the hydroxyl-producing cathode and to combine with the hydroxyl ions to form the metal hydroxide. The carbonate ions travel toward the acid-producing anode and form carbonic acid and/or water and carbon dioxide.

  1. Three Activities: One Hand Washes Another, I'm All Washed Up and Who is All Washed Up?

    NSDL National Science Digital Library

    ATEEC presents this problem-based lesson plan on risk assessment of environmental health issues. Students will study infectious diseases, particularly those spread via vector-borne, food-borne and water-borne means. They will learn about environmental exposures which cause various infectious diseases. The lesson consists of three individual activities: One Hand Washes Another, I'm All Washed Up... and Who is All Washed Up? Each activity stresses the importance of hand washing. Detailed instructions are provided for each activity. This resource is free to download. Users must first create a login with ATEEC's website to access the file.

  2. Adsorption Equilibrium of Polyethylene Glycol in the Copper Electroplating Solution on Activated Carbon.

    PubMed

    Chang; Chang; Tsai; Wu

    2000-12-01

    Polyethylene glycol (PEG) used as a brightening and stabilization agent at the concentration of 30 mg dm(-3) is a major organic additive in the copper electroplating solution. Activated carbon, Calgon Filtrasob 400, is used as the adsorbent to remove the PEG from the used electroplating solution in order to broaden the appeal of recycling it. The equilibrium of adsorption is attained within 14 days. The effect of the temperature on the amount of PEG adsorbed on the activated carbon is insignificant for the temperatures ranged from 288 to 313 K. The adsorption isotherm of PEG conforms to the Langmuir isotherm, q(e)=Q(L)K(L)C(e)/(1+K(L)C(e)), with a high correlation coefficient of 0.9979. The large values of the monolayer adsorption capacity, Q(L), of 303 mg g(-1) and the equilibrium constant, K(L), of 0.273 dm(3) mg(-1) show a great adsorption potential of PEG on the activated carbon. A high removal efficiency would be expected at such a low original concentration of PEG. From the results mentioned above, it is feasible to use activated carbon for removing PEG from the electroplating solution, thereby achieving the appeal of recycling. Copyright 2000 Academic Press. PMID:11071751

  3. Controls of carbonate mineralogy and solid-solution of Mg in calcite: evidence from spelean systems

    SciTech Connect

    Gonzalez, L.A.; Lohmann, K.C.

    1985-01-01

    Precipitation of carbonate minerals in spelean systems occurs under a wide range of fluid chemistry, Mg-Ca ratios, alkalinities, pH and temperatures; thus, spelean systems provide ideal settings to determine factors controlling the mineralogy of precipitated carbonates and solid-solution of Mg in calcite. Cave waters and actively-precipitating carbonate speleothems were collected from Carlsbad Caverns National Park, New Mexico and the Mammoth-Flint Cave System, Kentucky. Carbonate mineralogy of precipitated phases was determined by x-ray diffraction, and major and minor element composition of waters and accompanying minerals were determined by Atomic Absorption Spectrophotometry. Results demonstrate that at a constant CO3 concentration the precipitation threshold for calcite to aragonite is controlled dominantly by the Mg/Ca ratio of the ambient fluid. Aragonite precipitation is favored by high Mg/Ca ratios. Conversely, with increasing CO3 concentration at constant fluid Mg/Ca ratios, calcite is preferentially precipitated. Solid-solution of Mg in calcite is positively correlated with both increased Mg/Ca ratios and CO3 concentrations. These data suggest that Mg contents of calcite can not be defined solely in terms of a homogeneous distribution coefficient. Rather, Mg concentrations can be also be affected by the CO3 concentration and degree of calcite saturation, suggesting that the rate of crystal growth also plays and important role in Mg solid-solution in calcites.

  4. Collagen tissue treated with chitosan solutions in carbonic acid for improved biological prosthetic heart valves.

    PubMed

    Gallyamov, Marat O; Chaschin, Ivan S; Khokhlova, Marina A; Grigorev, Timofey E; Bakuleva, Natalia P; Lyutova, Irina G; Kondratenko, Janna E; Badun, Gennadii A; Chernysheva, Maria G; Khokhlov, Alexei R

    2014-04-01

    Calcification of bovine pericardium dramatically shortens typical lifetimes of biological prosthetic heart valves and thus precludes their choice for younger patients. The aim of the present work is to demonstrate that the calcification is to be mitigated by means of treatment of bovine pericardium in solutions of chitosan in carbonic acid, i.e. water saturated with carbon dioxide at high pressure. This acidic aqueous fluid unusually combines antimicrobial properties with absolute biocompatibility as far as at normal pressure it decomposes spontaneously and completely into H2O and CO2. Yet, at high pressures it can protonate and dissolve chitosan materials with different degrees of acetylation (in the range of 16-33%, at least) without any further pretreatment. Even exposure of the bovine pericardium in pure carbonic acid solution without chitosan already favours certain reduction in calcification, somewhat improved mechanical properties, complete biocompatibility and evident antimicrobial activity of the treated collagen tissue. The reason may be due to high extraction ability of this peculiar compressed fluidic mixture. Moreover, exposure of the bovine pericardium in solutions of chitosan in carbonic acid introduces even better mechanical properties and highly pronounced antimicrobial activity of the modified collagen tissue against adherence and biofilm formation of relevant Gram-positive and Gram-negative strains. Yet, the most important achievement is the detected dramatic reduction in calcification for such modified collagen tissues in spite of the fact that the amount of the thus introduced chitosan is rather small (typically ca. 1wt.%), which has been reliably detected using original tritium labelling method. We believe that these improved properties are achieved due to particularly deep and uniform impregnation of the collagen matrix with chitosan from its pressurised solutions in carbonic acid. PMID:24582232

  5. Linking variability in soil solution dissolved organic carbon to climate, soil type, and vegetation type

    NASA Astrophysics Data System (ADS)

    Camino-Serrano, Marta; Gielen, Bert; Luyssaert, Sebastiaan; Ciais, Philippe; Vicca, Sara; Guenet, Bertrand; Vos, Bruno De; Cools, Nathalie; Ahrens, Bernhard; Altaf Arain, M.; Borken, Werner; Clarke, Nicholas; Clarkson, Beverley; Cummins, Thomas; Don, Axel; Pannatier, Elisabeth Graf; Laudon, Hjalmar; Moore, Tim; Nieminen, Tiina M.; Nilsson, Mats B.; Peichl, Matthias; Schwendenmann, Luitgard; Siemens, Jan; Janssens, Ivan

    2014-05-01

    Lateral transport of carbon plays an important role in linking the carbon cycles of terrestrial and aquatic ecosystems. There is, however, a lack of information on the factors controlling one of the main C sources of this lateral flux, i.e., the concentration of dissolved organic carbon (DOC) in soil solution across large spatial scales and under different soil, vegetation, and climate conditions. We compiled a database on DOC in soil solution down to 80 cm and analyzed it with the aim, first, to quantify the differences in DOC concentrations among terrestrial ecosystems, climate zones, soil, and vegetation types at global scale and second, to identify potential determinants of the site-to-site variability of DOC concentration in soil solution across European broadleaved and coniferous forests. We found that DOC concentrations were 75% lower in mineral than in organic soil, and temperate sites showed higher DOC concentrations than boreal and tropical sites. The majority of the variation (R2 = 0.67-0.99) in DOC concentrations in mineral European forest soils correlates with NH4+, C/N, Al, and Fe as the most important predictors. Overall, our results show that the magnitude (23% lower in broadleaved than in coniferous forests) and the controlling factors of DOC in soil solution differ between forest types, with site productivity being more important in broadleaved forests and water balance in coniferous stands.

  6. Wash water waste pretreatment system

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Investigations were completed on wash waters based on each candidate personal cleansing agent. Evaluations of coagulants, antifoam agents, and the effect of promising antifoams on the chemical precipitation were included. Based on these evaluations two candidate soaps as well as their companion antifoam agents were selected for further work. Operating parameters included the effect of soap concentration, ferric chloride concentration, duration of mixing, and pore size of depth filters on the degree of soap removal. The effect of pressure on water flow through filter cartridges and on the rate of decline of water flow was also investigated. The culmination of the program was the recommendation of a pretreatment concept based on chemical precipitation followed by pressure filtration.

  7. Evaluation of biosurfactants for crude oil contaminated soil washing

    Microsoft Academic Search

    Kingsley Urum; Turgay Pekdemir

    2004-01-01

    An evaluation of the ability of aqueous biosurfactant solutions (aescin, lecithin, rhamnolipid, saponin and tannin) for possible applications in washing crude oil contaminated soil was carried out. The biosurfactants behaviour in soil–water, water–oil and oil–soil systems (such as foaming, solubilization, sorption to soil, emulsification, surface and interfacial tension) was measured and compared with a well-known chemical surfactant (sodium dodecyl sulphate,

  8. Soil washing: A preliminary assessment of its applicability to Hanford

    SciTech Connect

    Gerber, M A; Freeman, H D; Baker, E G; Riemath, W F

    1991-09-01

    Soil washing is being considered for treating soils at the US Department of Energy's (DOE) Hanford Site. As a result of over 50 years of operations to produce plutonium for the US Department of Defense and research for DOE, soils in areas within the Site are contaminated with hazardous wastes and radionuclides. In the soil washing process, contaminated soil is mixed with a liquid and then physically and/or chemically treated to dissolve the contaminants into solution and/or concentrate them in a small fraction of the soil. The purpose of this procedure is to separate the contaminants from the bulk of the soil. The key to successful application is to match the types of contaminants and soil characteristics with physical-chemical methods that perform well under the existing conditions. The applicability of soil washing to Hanford Site contaminated soils must take into account both the characteristics of the oil and the type of contamination. Hanford soils typically contain up to 90% sand, gravel, and cobbles, which generally are favorable characteristics for soil washing. For example, in soil samples from the north pond in the 300 Area, 80% to 90% of the soil particles were larger than 250 {mu}m. The principal contaminants in the soil are radionuclides, heavy metals, and nitrate and sulfate salts. For most of the sites, organic contaminants are either not present or are found in very low concentration. 28 refs., 5 figs., 10 tabs.

  9. InP synthesis by the synthesis, solute diffusion (SSD) method using glassy-carbon crucibles

    SciTech Connect

    Miskys, C.R.; Oliveira, C.E.M. de; Carvalho, M.M.G. de [UNICAMP-IFGW-DFA-LPD, Campinas, Sao Paulo (Brazil)

    1996-12-31

    An Indium Phosphide (InP) Synthesis system by the Synthesis, Solute Diffusion (SSD) method has been built. It provides high purity InP charges with low carrier densities (3 {times} 10{sup 14} to 2 {times} 10{sup 15} cm{sup {minus}3}) to be used as starting material for InP single-crystal Liquid Encapsulated Czochralski (LEC) growth. Glassy-carbon is a refractory material with low vapor pressure that can be moulded in various forms and sizes. Indeed the glassy-carbon crucible is reusable after the synthesis because InP does not stick to its walls. Preliminary electrical characteristics measurements showed residual carrier concentration below 3 {times} 10{sup 15} cm{sup {minus}3}. These results are comparable with those achieved utilizing quartz crucibles. The features denoted makes glassy-carbon an interesting alternative in comparison with quartz and PBN crucibles.

  10. Influence of temperature, chloride ions and chromium element on the electronic property of passive film formed on carbon steel in bicarbonate\\/carbonate buffer solution

    Microsoft Academic Search

    D. G. Li; Y. R. Feng; Z. Q. Bai; J. W. Zhu; M. S. Zheng

    2007-01-01

    The influences of temperature, chloride ions and chromium element on the electronic property of passive film formed on carbon steel in NaHCO3\\/Na2CO3 buffer solution are investigated by capacitance measurement and electrochemical impedance spectroscopy (EIS). The results show that the passive film appears n-type semiconductive character; with increasing the solution temperature, the addition of chromium into carbon steel and increasing the

  11. Short communication: Automatic washing of hooves can help control digital dermatitis in dairy cows.

    PubMed

    Thomsen, Peter T; Ersbøll, Annette Kjær; Sørensen, Jan Tind

    2012-12-01

    The objectives of this study were to develop and test a system for automatic washing of the hooves of dairy cows and to evaluate the effect of frequent automatic washing on the prevalence of digital dermatitis (DD). An automatic hoof washer was developed in an experimental dairy herd and tested in 6 commercial dairy herds in 2 experiments (1 and 2). In the experimental herd, automatic hoof washing resulted in cleaner hooves. In experiments 1 and 2, cows were washed after each milking on the left side only, leaving the right side unwashed as a within-cow control. In experiment 1, hooves were washed with a water and 0.4% soap solution. In experiment 2, hooves were washed with water only. In each experiment, DD was scored in a hoof-trimming chute approximately 60 d after the start of hoof washing. Data were analyzed using a generalized linear mixed model. The outcome was the DD status of each leg (DD positive or DD negative). Herd and cow within herd were included as random effects, and treatment (washing or control) was included as a fixed effect. The statistical analyses showed that the odds ratio of having DD was 1.48 in the control leg compared with the washed leg in experiment 1. In experiment 2, the odds ratio of having DD was 1.27 in the control leg compared with the washed leg. We concluded that automatic washing of hooves with water and soap can help decrease the prevalence of DD in commercial dairy herds. PMID:23063150

  12. Electrochemical studies of the film formation on lithium in propylene carbonate solutions under open circuit conditions

    SciTech Connect

    Geronov, Y.; Schwager, F.; Muller, R.H.

    1981-04-01

    The nature of protective surface layers formed on lithium in propylene carbonate solutions of LiClO/sub 4/ and LiAsF/sub 6/ at open circuit has been investigated by electrochemical pulse measurements and other techniques. The results are consistent with the fast formation of a compact thin layer of Li/sub 2/O by reaction with residual water. This layer acts as a solid ionic conductor. Slow corrosion processes produce a thicker porous overlayer.

  13. FILM FORMATION ON LITHIUM IN PROPYLENE CARBONATE SOLUTIONS UNDER OPEN CIRCUIT CONDITIONS

    SciTech Connect

    Geronov, Y.; Schwager, F.; Muller, R.H.

    1980-06-01

    The nature of protective surface layers formed on lithium in propylene carbonate solutions of LiClO{sub 4} and LiAsF{sub 6} at open circuit has been investigated by electrochemical pulse measurements. The results are consistent with the fastformation of a compact thin layer resulting from the reaction with residual water. This layer acts as a solid ionicconductor. Slow corrosion or decomposition processes produce a thicker porous overlayer.

  14. Carbon dioxide as refrigerant for tap water heat pumps: A comparison with the traditional solution

    Microsoft Academic Search

    Luca Cecchinato; Marco Corradi; Ezio Fornasieri; Lorenzo Zamboni

    2005-01-01

    Increased concern about the environmental impact of the refrigeration technology is leading toward design solutions aimed at improving the energy efficiency of the related applications, using eco-friendly refrigerants, i.e. ozone-friendly and with the least possible global warming potential (GWP). In this respect, carbon dioxide (ASHRAE R744) is seen today as one of the most promising refrigerants and is raising great

  15. SIMULTANEOUS ABSORPTION OF H2S AND CO2 INTO A SOLUTION OF SODIUM CARBONATE

    Microsoft Academic Search

    MATS WALLIN; STEFAN OLAUSSON

    1993-01-01

    The simultaneous absorption of H2S and CO2 has been studied both experimentally and theoretically. A model has been developed which predicts the absorption rates of H2S and CO2 into a sodium carbonate solution. The absorption rates are calculated according to the two-film theory. In the liquid film, the finite rate of the CO2 reaction was considered. Otherwise, in the liquid

  16. Capacitive deionization of NH 4 ClO 4 solutions with carbon aerogel electrodes

    Microsoft Academic Search

    J. C. Farmer; D. V. Fix; G. V. Mack; R. W. Pekala; J. F. Poco

    1996-01-01

    A process for the capacitive deionization of water with a stack of carbon aerogel electrodes has been developed by Lawrence Livermore National Laboratory (LLNL). Unlike ion exchange, one of the more conventional deionization processes, no chemicals are required for regeneration of the system. Electricity is used instead. An aqueous solution of NH4ClO4 is pumped through the electrochemical cell. After polarization,

  17. Removal of Chemazol Reactive Red 195 from aqueous solution by dehydrated beet pulp carbon

    Microsoft Academic Search

    Arzu Y. Dursun; Ozlem Tepe

    2011-01-01

    An agricultural low-cost by-product, dehydrated beet pulp carbon (DBPC) was used as an adsorbent for removal of Chemazol Reactive Red 195 (CRR 195) from aqueous solution. The surface area of DBPC was measured as 9.5m2g?1 by using BET method. The results indicated that adsorption was strongly pH-dependent and optimum pH was determined as 1.0. The maximum dye adsorption capacity was

  18. Filling of Carbon Nanotubes with Compounds in Solution or Melted Phase

    Microsoft Academic Search

    P. Lukanov; C.-M. Tîlmaciu; A. M. Galibert; B. Soula; E. Flahaut

    \\u000a Since their discovery, carbon nanotubes (CNT) have been found to exhibit remarkable structural, mechanical and electronic\\u000a properties. One such property is the ability to encapsulate foreign materials inside their cylindrical cavity, for application\\u000a in different fields. The procedures to fill CNT may be classified into two main groups: (a) filling in solution, using the\\u000a wet chemistry route and (b) filling

  19. Dispersing carbon nanotubes in aqueous solutions by a silicon surfactant: Experimental and molecular dynamics simulation study

    Microsoft Academic Search

    Jinyu Pang; Guiying Xu; Shiling Yuan; Yebang Tan; Fang He

    2009-01-01

    The dispersion effect of carbon nanotubes (CNTs) in aqueous solutions by a silicon surfactant (ethoxy modified trisiloxane, named Ag-64) was investigated in detail using experimental method and molecular dynamics simulation. The Si–O–Si chain of silicon surfactant was flexible due to long Si–C bond and it could easily wrap onto the surface of CNTs through hydrophobic and other intermolecular interactions. The

  20. Metastable Equilibrium Solubility Behavior of Carbonated Apatite in the Presence of Solution Strontium

    Microsoft Academic Search

    D. D. Heslop; Y. Bi; A. A. Baig; W. I. Higuchi

    2003-01-01

    The purpose of this study was to use the concept of metastable equilibrium solubility (MES) to describe the anomalous solubility behavior of carbonated apatite (CAP) in the presence of solution strontium. A CAP sample (4.8 wt% CO 3, synthesized at 70°C) was prepared by precipitation. Baseline MES distributions were determined in a series of 0.1 M acetate buffers containing only

  1. The removal of carbon dioxide with activated solutions of methyl-diethanol-amine

    Microsoft Academic Search

    S. van Loo; E. P. van Elk; G. F. Versteeg

    2007-01-01

    The (bulk) removal of carbon-dioxide (CO2) from industrial gases, e.g. natural gas, is usually realized with a reactive absorption technique in which (non-)aqueous solutions of alkanolamines are used.From the absorption rate point of view, primary or secondary amines are preferred. However, in case the costs of regeneration are also taken into account, tertiary amines are much more attractive. In order

  2. The removal of carbon dioxide with activated solutions of methyl-diethanol-amine

    Microsoft Academic Search

    S. van Loo; E. P. van Elk; G. F. Versteeg

    The (bulk) removal of carbon-dioxide (CO2) from industrial gases, e.g. natural gas, is usually realized with a reactive absorption technique in which (non-)aqueous solutions of alkanolamines are used. From the absorption rate point of view, primary or secondary amines are preferred. However, in case the costs of regeneration are also taken into account, tertiary amines are much more attractive. In

  3. Hydrothermal opening of multiwall carbon nanotube with H 2O 2 solution

    Microsoft Academic Search

    Marek Wisniewski; Artur P. Terzyk; Yoshiyuki Hattori; Katsumi Kaneko; Fujio Okino; Bartosz Kruszka

    2009-01-01

    A new single-step method of multiwalled carbon nanotubes opening is reported. It bases on hydrothermal treatment with H2O2 solution, so in this way one reduces energy and water consuming purification process. The efficiency of a new method is compared for the same tubes but opened by the ‘typical’ procedure using treatment with molten alkaline mixture. The data of low temperature

  4. Anion influence in lead removal from aqueous solution by deposition onto a vitreous carbon electrode

    Microsoft Academic Search

    G. Carreiio; E. Sosa; I. GonzAlez; C. Ponce-de-Leh; N. Batina; M. T. Oropeza

    We investigated the electrolytic removal of Pb(I1) from aqueous solutions containing different electrolytes (nitrate, chloride or sulfate), by electrolysis onto reticulated vitreous carbon electrode (RVC). The efficiency of the electrolytic process of lead removal was found to be a function of electrolyte composition. The chloride containing electrolyte, provided the highest efficiency of lead removal, while removing Pb(I1) from the sulfate

  5. Removal of hexavalent chromium from acidic aqueous solutions using rice straw-derived carbon.

    PubMed

    Hsu, Nai-Hua; Wang, Shan-Li; Liao, Yi-Huei; Huang, Shiuh-Tsuen; Tzou, Yu-Min; Huang, Yuh-Ming

    2009-11-15

    This study evaluates the removal of Cr(VI) from water by carbon derived from the burning of rice straw. Rice straw was burned in the air to obtain rice carbon (RC), and then the removal of Cr(VI) by RC was investigated under various pHs and ionic strengths. After the experiments, the oxidation state of Cr bound to RC was analyzed using X-ray photoelectron spectroscopy, which revealed that Cr bound to RC was predominately in the trivalent form. The results showed that upon reacting with RC, Cr(VI) was reduced to Cr(III), which was either adsorbed on RC or released back into solution. The extent and rate of Cr(VI) removal increased with decreasing solution pH because the Cr(VI) adsorption and the subsequent reduction of adsorbed Cr(VI) to Cr(III) both occur preferentially at low pH. The minimal effect of ionic strength on the rates of Cr(VI) removal and Cr(III) adsorption indicated specific interactions between Cr(VI)/Cr(III) and their surface binding sites on RC. These results suggest that rice straw-based carbon may be effectively used at low pH as a substitute for activated carbon for the treatment of Cr(VI) contaminated water. PMID:19619940

  6. Competitive adsorption of ibuprofen and amoxicillin mixtures from aqueous solution on activated carbons.

    PubMed

    Mansouri, Hayet; Carmona, Rocio J; Gomis-Berenguer, Alicia; Souissi-Najar, Souad; Ouederni, Abdelmottaleb; Ania, Conchi O

    2015-07-01

    This work investigates the competitive adsorption under dynamic and equilibrium conditions of ibuprofen (IBU) and amoxicillin (AMX), two widely consumed pharmaceuticals, on nanoporous carbons of different characteristics. Batch adsorption experiments of pure components in water and their binary mixtures were carried out to measure both adsorption equilibrium and kinetics, and dynamic tests were performed to validate the simultaneous removal of the mixtures in breakthrough experiments. The equilibrium adsorption capacities evaluated from pure component solutions were higher than those measured in dynamic conditions, and were found to depend on the porous features of the adsorbent and the nature of the specific/dispersive interactions that are controlled by the solution pH, density of surface change on the carbon and ionization of the pollutant. A marked roll-up effect was observed for AMX retention on the hydrophobic carbons, not seen for the functionalized adsorbent likely due to the lower affinity of amoxicillin towards the carbon adsorbent. Dynamic adsorption of binary mixtures from wastewater of high salinity and alkalinity showed a slight increase in IBU uptake and a reduced adsorption of AMX, demonstrating the feasibility of the simultaneous removal of both compounds from complex water matrices. PMID:25554087

  7. Adsorption of bisphenol-A from aqueous solution onto minerals and carbon adsorbents.

    PubMed

    Tsai, Wen-Tien; Lai, Chi-Wei; Su, Ting-Yi

    2006-06-30

    The adsorption behaviors of bisphenol-A, which has been listed as one of endocrine disrupting chemicals, from aqueous solution onto four minerals including andesite, diatomaceous earth, titanium dioxide, and activated bleaching earth, and two activated carbons with coconut-based and coal-based virgins were examined in this work. Based on the adsorption results at the specified conditions, the adsorption capacities of activated carbons are significantly larger than those of mineral adsorbents, implying that the former is effective for removal of the highly hydrophobic adsorbate from the aqueous solution because of its high surface area and low surface polarity. The adsorption capacities of bisphenol-A onto these mineral adsorbents with different pore properties are almost similar in magnitude mainly due to the weakly electrostatic interaction between the mineral surface with negative charge and the target adsorbate with hydrophobic nature. Further, a simplified kinetic model, pseudo-second-order, was tested to investigate the adsorption behaviors of bisphenol-A onto the two common activated carbons at different solution conditions. It was found that the adsorption process could be well described with the pseudo-second-order model. The kinetic parameters of the model obtained in the present work are in line with the pore properties of the two adsorbents. PMID:16343748

  8. Removal of organic contaminants from aqueous solution by cattle manure compost (CMC) derived activated carbons

    NASA Astrophysics Data System (ADS)

    Qian, Qingrong; Chen, Qinghua; Machida, Motoi; Tatsumoto, Hideki; Mochidzuki, Kazuhiro; Sakoda, Akiyoshi

    2009-04-01

    The activated carbons (ACs) prepared from cattle manure compost (CMC) with various pore structure and surface chemistry were used to remove phenol and methylene blue (MB) from aqueous solutions. The adsorption equilibrium and kinetics of two organic contaminants onto the ACs were investigated and the schematic models for the adsorptive processes were proposed. The result shows that the removal of functional groups from ACs surface leads to decreasing both rate constants for phenol and MB adsorption. It also causes the decrement of MB adsorption capacity. However, the decrease of surface functional groups was found to result in the increase of phenol adsorption capacity. In our schematic model for adsorptive processes, the presence of acidic functional groups on the surface of carbon is assumed to act as channels for diffusion of adsorbate molecules onto small pores, therefore, promotes the adsorption rate of both phenol and MB. In phenol solution, water molecules firstly adsorb on surface oxygen groups by H-bonding and subsequently form water clusters, which cause partial blockage of the micropores, deduce electrons from the ?-electron system of the carbon basal planes, hence, impede or prevent phenol adsorption. On the contrary, in MB solution, the oxygen groups prefer to combine with MB + cations than water molecules, which lead to the increase of MB adsorption capacity.

  9. UNDERSTANDING HAND WASHING BEHAVIOR RESULTS OF FORMATIVE RESEARCH ON HAND WASHING IN

    E-print Network

    unknown authors

    Diarrhea is one of the leading killers, globally and in refugee camps, and strong evidence indicates that hand washing with soap is one of the most effective interventions available to reduce the incidence of diarrhea. Yet little is known about why people in refugee camps do or do not wash their hands, and what approaches will increase hand washing.

  10. EFRT M-12 Issue Resolution: Solids Washing

    SciTech Connect

    Baldwin, David L.; Schonewill, Philip P.; Toth, James J.; Huckaby, James L.; Eslinger, Paul W.; Hanson, Brady D.; Kurath, Dean E.; Minette, Michael J.

    2009-08-14

    Pacific Northwest National Laboratory (PNNL) has been tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed, and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes.” The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. Two operating scenarios were evaluated for the ultrafiltration process (UFP) and leaching operations. The first scenario has caustic leaching performed in the UFP-VSL-T01A/B ultrafiltration feed vessels, identified as Integrated Test A. The second scenario has caustic leaching conducted in the UFP-VSL-T02A ultrafiltration feed preparation vessel, identified as Integrated Test B. Washing operations in PEP Integrated Tests A and B were conducted successfully as per the approved run sheets. However, various minor instrumental problems occurred, and some of the process conditions specified in the run sheet were not met during the wash operations, such as filter-loop flow-rate targets not being met. Five analytes were selected based on full solubility and monitored in the post-caustic-leach wash as successful indicators of washing efficiency. These were aluminum, sulfate, nitrate, nitrite, and free hydroxide. Other analytes, including sodium, oxalate, phosphate, and total dissolved solids, showed indications of changing solubility; therefore, they were unsuitable for monitoring washing efficiency. In the post-oxidative-leach wash, two analytes with full solubility were selected as suitable indicators of washing efficiency. These were chromium and oxalate. Other analytes, including sodium, manganese, nitrate, and total dissolved solids, showed indications of changing solubility; therefore, they were unsuitable for monitoring washing efficiency. An overall wash efficiency of 1.00 ± 0.01 was determined for the post-caustic-leach wash. The overall wash efficiency for the post-oxidative-leach wash was determined also to be 0.99 ± 0.01. These wash efficiencies were based on the weighted least squares fit of the full data set for each applicable analyte and are an average of several analytes traced during the washing steps in Integrated Tests A and B. Incremental wash efficiencies as a function of wash step were also given to provide an indication of the variability during the washing process. Chemical tracer tests resulted in the major conclusion that nearly complete mixing was achieved between 2 and 4 minutes after tracer injection. With inconsistent filter-loop flow rates and other mixing parameters, future process conditions should be taken into account during further interpretation of these data. A slight decrease of 8 to 10% in the tracer concentration between 4 and 60 minutes suggests that there was a relatively small unmixed region that mixed over the course of the 1-hour test. The IW batch time interval, defined as the duration between the start of the IW wash injection for a batch to the start for the IW wash injection for the subsequent batch, was often close to or less than the required 4-minute mixing time indicated by the tracer tests. Such short batch durations did not appear to have significantly impacted the washing efficiencies.

  11. Sodium wash station operational testing report

    SciTech Connect

    Knotek, H.M.

    1996-10-01

    This document provides the test report for the Operability Test Procedure (OTP) performed on the Westinghouse Hanford Company developed Sodium Wash Station. The purpose of the Sodium Wash Station is to provide the capability to control and monitor the water vapor nitrogen reaction of sodium remaining in drained tanks and other components.

  12. WASH SOLVENT REUSE IN PAINT PRODUCTION

    EPA Science Inventory

    This project evaluated solvent used to clean paint manufacture equipment for its utility in production of subsequent batches of solvent-borne paint. eusing wash solvent would reduce the amount of solvent disposed of as waste. he evaluation of this wash-solvent recovery technology...

  13. SOIL-WASHING TECHNOLOGY AND PRACTICE

    EPA Science Inventory

    Soil washing in the United States has been studied and evaluated with increasing the last 15 to 20 years. t is now entering a phase of actual use and acceptance as its applicability and economics become clearer. his paper reviews the principals behind soil washing, methods of pre...

  14. The adsorption of pharmaceutically active compounds from aqueous solutions onto activated carbons.

    PubMed

    Raki?, Vesna; Rac, Vladislav; Krmar, Marija; Otman, Otman; Auroux, Aline

    2015-01-23

    In this study, the adsorption of pharmaceutically active compounds - salicylic acid, acetylsalicylic acid, atenolol and diclofenac-Na onto activated carbons has been studied. Three different commercial activated carbons, possessing ?650, 900 or 1500m(2)g(-1) surface areas were used as solid adsorbents. These materials were fully characterized - their textural, surface features and points of zero charge have been determined. The adsorption was studied from aqueous solutions at 303K using batch adsorption experiments and titration microcalorimetry, which was employed in order to obtain the heats evolved as a result of adsorption. The maximal adsorption capacities of investigated solids for all target pharmaceuticals are in the range of 10(-4)molg(-1). The obtained maximal retention capacities are correlated with the textural properties of applied activated carbon. The roles of acid/base features of activated carbons and of molecular structures of adsorbate molecules have been discussed. The obtained results enabled to estimate the possibility to use the activated carbons in the removal of pharmaceuticals by adsorption. PMID:24857621

  15. Transport of ions in mesoporous carbon electrodes during capacitive deionization of high-salinity solutions.

    PubMed

    Sharma, K; Kim, Y-H; Gabitto, J; Mayes, R T; Yiacoumi, S; Bilheux, H Z; Walker, L M H; Dai, S; Tsouris, C

    2015-01-27

    Desalination of high-salinity solutions has been studied using a novel experimental technique and a theoretical model. Neutron imaging has been employed to visualize lithium ions in mesoporous carbon materials, which are used as electrodes in capacitive deionization (CDI) for water desalination. Experiments were conducted with a flow-through CDI cell designed for neutron imaging and with lithium-6 chloride ((6)LiCl) as the electrolyte. Sequences of neutron images have been obtained at a relatively high concentration of (6)LiCl solution to provide information on the transport of ions within the electrodes. A new model that computes the individual ionic concentration profiles inside mesoporous carbon electrodes has been used to simulate the CDI process. Modifications have also been introduced into the simulation model to calculate results at high electrolyte concentrations. Experimental data and simulation results provide insight into why CDI is not effective for desalination of high ionic-strength solutions. The combination of experimental information, obtained through neutron imaging, with the theoretical model will help in the design of CDI devices, which can improve the process for high ionic-strength solutions. PMID:25533167

  16. Removal of copper and cadmium from aqueous solution using switchgrass biochar produced via hydrothermal carbonization process.

    PubMed

    Regmi, Pusker; Garcia Moscoso, Jose Luis; Kumar, Sandeep; Cao, Xiaoyan; Mao, Jingdong; Schafran, Gary

    2012-10-30

    Biochar produced from switchgrass via hydrothermal carbonization (HTC) was used as a sorbent for the removal of copper and cadmium from aqueous solution. The cold activation process using KOH at room temperature was developed to enhance the porous structure and sorption properties of the HTC biochar. The sorption efficiency of HTC biochar and alkali activated HTC biochar (HTCB) for removing copper and cadmium from aqueous solution were compared with commercially available powdered activated carbon (PAC). The present batch adsorption study describes the effects of solution pH, biochar dose, and contact time on copper and cadmium removal efficiency from single metal ion aqueous solutions. The activated HTCB exhibited a higher adsorption potential for copper and cadmium than HTC biochar and PAC. Experiments conducted with an initial metal concentration of 40 mg/L at pH 5.0 and contact time of 24 h resulted in close to 100% copper and cadmium removal by activated HTCB at 2 g/L, far greater than what was observed for HTC biochar (16% and 5.6%) and PAC (4% and 7.7%). The adsorption capacities of activated HTCB for cadmium removal were 34 mg/g (0.313 mmol/g) and copper removal was 31 mg/g (0.503 mmol/g). PMID:22687632

  17. Modelling Of Displacement Washing Of Pulp Bed Using Orthogonal Collocation On Finite Elements

    NASA Astrophysics Data System (ADS)

    Arora, Shelly; Potů?ek, František; Dhaliwal, S. S.; Kukreja, V. K.

    2009-07-01

    Mechanism of displacement washing of packed bed of porous, compressible and cylindrical particles, e.g., fibers is presented with the help of an axial dispersion model involving Peclet number (Pe) and Biot number (Bi). Bulk fluid concentration and intra-pore solute concentration are related by Langmuir adsorption isotherm. Model equations have been solved using orthogonal collocation on finite elements using Lagrangian interpolating polynomials as base functions. Displacement washing has been simulated using a laboratory washing cell and experiments have been performed on pulp beds formed from unbeaten, unbleached kraft fibers. Model predicted values have been compared with experimental values to check the applicability of the method.

  18. Lead and copper removal from aqueous solutions using carbon foam derived from phenol resin.

    PubMed

    Lee, Chang-Gu; Jeon, Jun-Woo; Hwang, Min-Jin; Ahn, Kyu-Hong; Park, Chanhyuk; Choi, Jae-Woo; Lee, Sang-Hyup

    2015-07-01

    Phenolic resin-based carbon foam was prepared as an adsorbent for removing heavy metals from aqueous solutions. The surface of the produced carbon foam had a well-developed open cell structure and the specific surface area according to the BET model was 458.59m(2)g(-1). Batch experiments showed that removal ratio increased in the order of copper (19.83%), zinc (34.35%), cadmium (59.82%), and lead (73.99%) in mixed solutions with the same initial concentration (50mgL(-1)). The results indicated that the Sips isotherm model was the most suitable for describing the experimental data of lead and copper. The maximum adsorption capacity of lead and copper determined to Sips model were 491mgg(-1) and 247mgg(-1). The obtained pore diffusion coefficients for lead and copper were found to be 1.02×10(-6) and 2.42×10(-7)m(2)s(-1), respectively. Post-sorption characteristics indicated that surface precipitation was the primary mechanism of lead and copper removal by the carbon foam, while the functional groups on the surface of the foam did not affect metal adsorption. PMID:25819762

  19. Sodium carbonate poisoning

    MedlinePLUS

    Sodium carbonate (also known as washing soda or soda ash) is a chemical found in many household and ... products. This article focuses on poisoning due to sodium carbonate. This is for information only and not for ...

  20. Effect of multiple washing in salicylic acid on the bacterial flora of the skin of processed broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to determine changes in the bacterial flora of the skin of processed broilers after each of five consecutive washings in solutions of the keratolytic agent, salicylic acid. Skin samples from commercially processed broiler carcasses were divided into 3 groups and washed in ...

  1. Dispersion of Single-Walled Carbon Nanotubes in Aqueous Solutions of the Anionic Surfactant NaDDBS

    E-print Network

    Resasco, Daniel

    Dispersion of Single-Walled Carbon Nanotubes in Aqueous Solutions of the Anionic Surfactant Na surfactants. Although the efficiency of anionic, cationic, and nonionic surfactants has been demonstrated to different extents, the exact mechanism by which carbon nanotubes and the different surfactants interact

  2. Electrochemical injection of organic corrosion inhibitors into carbonated cementitious materials: Part 1. Effects on pore solution chemistry

    Microsoft Academic Search

    S. Sawada; J. Kubo; C. L. Page; M. M. Page

    2007-01-01

    This series of investigations was intended to clarify phenomena associated with electrochemical injection of the organic base corrosion inhibitors, ethanolamine and guanidine, into carbonated concrete. In Part 1, experiments were conducted with laminated specimens of carbonated cement paste, that were specially designed to facilitate analysis with adequate spatial resolution to assess changes in their pore solution phase chemistry after they

  3. Effect of solution additives on the performance of PMAN carbon anodes in 1M LiPF{sub 6}/EC-DMC solutions

    SciTech Connect

    Guidotti, R.A.; Johnson, B.J. [Sandia National Labs., Albuquerque, NM (United States). Battery Development Dept.

    1996-12-31

    A study was undertaken to examine the use of a number of solution additives in 1M LiPF{sub 6}/ethylene carbonate (EC)-dimethyl carbonate (DMC) solutions to improve the performance of carbon anodes derived from polymethylacrylonitrile (PMAN)-divinylbenzene (DVB) copolymers. The study goals were to improve the cycle life and reduce the formation of the passivation layer during the first reduction, thereby minimizing the irreversible-capacity losses. Additives studied were 12-crown-4 (12-Cr-4) ether, decalin, and dilithium phthalocyanine (Li{sub 2}Pc). The carbon performance was characterized by galvanostatic cycling, cyclic voltammetry, and complex-impedance spectroscopy. Limited success was obtained with 12-Cr-4 ether at 0.25 M and decalin at 1 v/o. Poor results were noted with Li{sub 2}Pc at 0.025 M and 0.5 M.

  4. The effects of water on the passive behavior of 1018 carbon steel in organic solutions

    SciTech Connect

    Shifler, D.A.; Kruger, J. (John Hopkins Univ., Baltimore, MD (United States). Dept. of Materials Science and Engineering); Moran, P.J. (Naval Academy, Annapolis, MD (United States). Dept. of Mechanical Engineering)

    1994-04-01

    The passivation and breakdown behavior of 1018 carbon steel in propylene carbonate (PC) or dimethoxyethane (DME) mixtures with water and containing 0.5M LiAsF[sub 6] were studied. The behavior of the steel in the organic solvent/water mixtures was highly dependent on the organic solvent. The anodic polarization of carbon steel displayed active-passive behavior in 10--90 mole percent (m/o) PC/H[sub 2]O mixtures and a tenuous degree of stability within the passive range. The anodic polarization of carbon steel displayed no active-passive behavior in 50--90 m/o DME/H[sub 2]O mixtures and displayed active-passive behavior in 10--30 m/o DME/H[sub 2]O mixtures. The steel was stable within the passive range of these DME/H[sub 2]O solutions. The breakdown potential of the steel in DME/H[sub 2]O mixtures is more electropositive than the oxidation potential of the DME solvent at all molar ratios.

  5. Carbon enters silica forming a cristobalite-type CO2-SiO2 solid solution.

    PubMed

    Santoro, Mario; Gorelli, Federico A; Bini, Roberto; Salamat, Ashkan; Garbarino, Gaston; Levelut, Claire; Cambon, Olivier; Haines, Julien

    2014-01-01

    Extreme conditions permit unique materials to be synthesized and can significantly update our view of the periodic table. In the case of group IV elements, carbon was always considered to be distinct with respect to its heavier homologues in forming oxides. Here we report the synthesis of a crystalline CO2-SiO2 solid solution by reacting carbon dioxide and silica in a laser-heated diamond anvil cell (P = 16-22 GPa, T>4,000 K), showing that carbon enters silica. Remarkably, this material is recovered to ambient conditions. X-ray diffraction shows that the crystal adopts a densely packed ?-cristobalite structure (P4(1)2(1)2) with carbon and silicon in fourfold coordination to oxygen at pressures where silica normally adopts a sixfold coordinated rutile-type stishovite structure. An average formula of C0.6(1)Si0.4(1)O2 is consistent with X-ray diffraction and Raman spectroscopy results. These findings may modify our view on oxide chemistry, which is of great interest for materials science, as well as Earth and planetary sciences. PMID:24781844

  6. Carbon enters silica forming a cristobalite-type CO2-SiO2 solid solution

    NASA Astrophysics Data System (ADS)

    Santoro, Mario; Gorelli, Federico A.; Bini, Roberto; Salamat, Ashkan; Garbarino, Gaston; Levelut, Claire; Cambon, Olivier; Haines, Julien

    2014-04-01

    Extreme conditions permit unique materials to be synthesized and can significantly update our view of the periodic table. In the case of group IV elements, carbon was always considered to be distinct with respect to its heavier homologues in forming oxides. Here we report the synthesis of a crystalline CO2-SiO2 solid solution by reacting carbon dioxide and silica in a laser-heated diamond anvil cell (P=16-22?GPa, T>4,000?K), showing that carbon enters silica. Remarkably, this material is recovered to ambient conditions. X-ray diffraction shows that the crystal adopts a densely packed ?-cristobalite structure (P41212) with carbon and silicon in fourfold coordination to oxygen at pressures where silica normally adopts a sixfold coordinated rutile-type stishovite structure. An average formula of C0.6(1)Si0.4(1)O2 is consistent with X-ray diffraction and Raman spectroscopy results. These findings may modify our view on oxide chemistry, which is of great interest for materials science, as well as Earth and planetary sciences.

  7. Dissolution of Uranium(IV) Oxide in Solutions of Ammonium Carbonate and Hydrogen Peroxide

    SciTech Connect

    Smith, Steven C.; Peper, Shane M.; Douglas, Matthew; Ziegelgruber, Kate L.; Finn, Erin C.

    2009-09-12

    Understanding the dissolution characteristics of uranium oxides is of fundamental scientific interest. Bench scale experiments were conducted to determine the optimal dissolution parameters of uranium(IV) oxide (UO2) powder in solutions of ammonium carbonate [(NH4)2CO3] and hydrogen peroxide (H2O2). Experimental parameters included variable peroxide and carbonate concentrations, and temperature. Results indicate the dissolution rate of UO2 in 1 M (NH4)2CO3 increases linearly with peroxide concentration ranging from 0.05 – 2 M (1:1 to 40:1 mol ratio H2O2:U), with no apparent maximum rate reached under the limited conditions used in our study. Temperature ranging studies show the dissolution rate of UO2 in 1 M (NH4)2CO3 and 0.1 M H2O2 (2:1 mol ratio H2O2:U) increases linearly from 15 °C to 60 °C, again with no apparent maximum rate reached. Dissolution of UO2 in solutions with constant [H2O2] and [(NH4)2CO3] ranging from 0.5 to 2 M showed no difference in rate; however dissolution was significantly reduced in 0.05 M (NH4)2CO3 solution. The results of this study demonstrate the influence of [H2O2], [(NH4)2CO3], and temperature on the dissolution of UO2 in peroxide-containing (NH4)2CO3 solutions. Future studies are planned to elucidate the solution and solid state complexes in these systems.

  8. Wash water solids removal system study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    During wash water purification, surfactants tend to precipitate and foul the RO membranes, causing water flux decline and loss of salt rejection. The use of 165 to 190 ppm ferric chloride and optionally 0.25 to 1.0 ppm polymeric flocculate precipitates 92 to 96 percent of the surfactant from an Olive Leaf Soap based wash water. Crossflow filtration and pressure filtration yield good soap rejection at high water flux rates. Post-treatment of the chemically pretreated and filtered wash water with activated charcoal removes the residual soap down to an undetectable level.

  9. Thermodynamics of pentachlorophenol adsorption from aqueous solutions by oxidized multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Abdel Salam, M.; Burk, R. C.

    2008-12-01

    Chemical modification of MWCNTs via oxidation proved to be a useful tool to improve the suspension stability and solubility of MWCNTs in aqueous solution. Multi-walled carbon nanotubes (MWCNTs) were oxidized using different oxidizing agents and the produced oxidized MWCNTs were characterized using different techniques. IR measurements showed the presence of carboxylic acid function groups especially for the MWCNTs oxidized with nitric acid and hydrogen peroxide. Oxidation of MWCNTs increased their solubility in aqueous solution and hence enhances the contact between the carbon nanotubes and the water and pentachlorophenol molecules. The oxidized MWCNTs were used to study the removal of pentachlorophenol (PCP) from aqueous solutions. The equilibrium adsorption of PCP on the oxidized MWCNTs at various temperatures was studied and the adsorption equilibrium was well described using different adsorption models. The thermodynamic of adsorption was studied at different temperatures and the results showed that the adsorption process was product favored, and becomes more so at higher temperature, since the adsorption is endothermic in general.

  10. Influence of Cu electroplating solutions on boron carbon nitride (BCN) film

    NASA Astrophysics Data System (ADS)

    Aoki, Hidemitsu; Hara, Makoto; Masuzumi, Takuro; Mazumder, Motaharu K.; Ooi, Naoki; Watanabe, Daisuke; Kimura, Chiharu; Sugino, Takashi

    2009-01-01

    Cu electroplating is required for the fabrication of Cu/low-k interconnections. The permeation of a plating solution into low-k films during Cu electroplating is a serious challenge for 45-nm nodes and more complex devices. We investigated the influence of Cu electroplating solutions on boron carbon nitride (BCN) as a low-k film. After dipping it into a Cu electroplating solution that contained additives, the BCN film's hydrophilic surface changed to a hydrophobic surface, and the incorporation of water into the BCN film was suppressed by surfactant adsorption. Sulfuric residue was detected on the BCN sample by thermal desorption spectroscopy after treatment in the Cu electroplating solution with additives; however, it was found through electrical measurements that this solution did not affect the leakage current or the dielectric constant of the BCN film. We successfully fabricated an electroplating Cu layer on a BCN film with good adhesion, and we believe that this BCN film is a sufficiently useful material for Cu/BCN integration in LSI.

  11. Decontamination of adsorbed chemical warfare agents on activated carbon using hydrogen peroxide solutions.

    PubMed

    Osovsky, Ruth; Kaplan, Doron; Nir, Ido; Rotter, Hadar; Elisha, Shmuel; Columbus, Ishay

    2014-09-16

    Mild treatment with hydrogen peroxide solutions (3-30%) efficiently decomposes adsorbed chemical warfare agents (CWAs) on microporous activated carbons used in protective garments and air filters. Better than 95% decomposition of adsorbed sulfur mustard (HD), sarin, and VX was achieved at ambient temperatures within 1-24 h, depending on the H2O2 concentration. HD was oxidized to the nontoxic HD-sulfoxide. The nerve agents were perhydrolyzed to the respective nontoxic methylphosphonic acids. The relative rapidity of the oxidation and perhydrolysis under these conditions is attributed to the microenvironment of the micropores. Apparently, the reactions are favored due to basic sites on the carbon surface. Our findings suggest a potential environmentally friendly route for decontamination of adsorbed CWAs, using H2O2 without the need of cosolvents or activators. PMID:25133545

  12. Dehydration and crystallization of amorphous calcium carbonate in solution and in air

    PubMed Central

    Ihli, Johannes; Wong, Wai Ching; Noel, Elizabeth H.; Kim, Yi-Yeoun; Kulak, Alexander N.; Christenson, Hugo K.; Duer, Melinda J.; Meldrum, Fiona C.

    2014-01-01

    The mechanisms by which amorphous intermediates transform into crystalline materials are poorly understood. Currently, attracting enormous interest is the crystallization of amorphous calcium carbonate, a key intermediary in synthetic, biological and environmental systems. Here we attempt to unify many contrasting and apparently contradictory studies by investigating this process in detail. We show that amorphous calcium carbonate can dehydrate before crystallizing, both in solution and in air, while thermal analyses and solid-state nuclear magnetic resonance measurements reveal that its water is present in distinct environments. Loss of the final water fraction—comprising less than 15% of the total—then triggers crystallization. The high activation energy of this step suggests that it occurs by partial dissolution/recrystallization, mediated by surface water, and the majority of the particle then crystallizes by a solid-state transformation. Such mechanisms are likely to be widespread in solid-state reactions and their characterization will facilitate greater control over these processes. PMID:24469266

  13. Utilization of carbon nanotubes for the removal of rhodamine B dye from aqueous solutions.

    PubMed

    Kumar, Sandeep; Bhanjana, Gaurav; Jangra, Kavita; Dilbaghi, Neeraj; Umar, Ahmad

    2014-06-01

    Carbon nanotubes (CNTs) are attracting increasing research interest as promising adsorbents for harmful cations, anions, and other organic and inorganic impurities present in natural sources of water. This study examined the feasibility of removing Rhodamine B dye from aqueous solutions using multi walled carbon nanotubes (MWCNTs) synthesized by chemical vapor deposition (CVD) method. The effects of dye concentration, pH and contact time on adsorption of direct dye by CNTs were also evaluated. The study used the Langmuir and Temkin isotherms to describe equilibrium adsorption. Additionally, pseudo second-order model was adopted to evaluate experimental data and thereby elucidate the kinetic adsorption process. The adsorption percentage of dye increased as contact time increased. Conversely, the adsorption percentage of dye decreased as dye concentration increased. The pseudo second-order model best represented adsorption kinetics. The capacity of CNTs to adsorb Rhodamine B was 65-90% at different pH values. PMID:24738392

  14. Waste washing pre-treatment of municipal and special waste.

    PubMed

    Cossu, Raffaello; Lai, Tiziana; Pivnenko, Kostyantyn

    2012-03-15

    Long-term pollution potential in landfills is mainly related to the quality of leachate. Waste can be conveniently treated prior to landfilling with an aim to minimizing future emissions. Washing of waste represents a feasible pre-treatment method focused on controlling the leachable fraction of residues and relevant impact. In this study, non-recyclable plastics originating from source segregation, mechanical-biological treated municipal solid waste (MSW), bottom ash from MSW incineration and automotive shredder residues (ASR) were treated and the removal efficiency of washing pre-treatment prior to landfilling was evaluated. Column tests were performed to simulate the behaviour of waste in landfill under aerobic and anaerobic conditions. The findings obtained revealed how waste washing treatment (WWT) allowed the leachability of contaminants from waste to be reduced. Removal rates exceeding 65% were obtained for dissolved organic carbon (DOC), chemical oxygen demand (COD) and Total Kjeldahl Nitrogen (TKN). A percentage decrease of approximately 60% was reached for the leachable fraction of chlorides, sulphates, fluoride and metals, as proved by a reduction in electric conductivity values (70%). PMID:21968117

  15. A Hydro-mechanical Model and Analytical Solutions for Geomechanical Modeling of Carbon Dioxide Geological Sequestration

    SciTech Connect

    Xu, Zhijie; Fang, Yilin; Scheibe, Timothy D.; Bonneville, Alain

    2012-05-15

    We present a hydro-mechanical model for geological sequestration of carbon dioxide. The model considers the poroelastic effects by taking into account the coupling between the geomechanical response and the fluid flow in greater detail. The simplified hydro-mechanical model includes the geomechanical part that relies on the linear elasticity, while the fluid flow is based on the Darcy’s law. Two parts were coupled using the standard linear poroelasticity. Analytical solutions for pressure field were obtained for a typical geological sequestration scenario. The model predicts the temporal and spatial variation of pressure field and effects of permeability and elastic modulus of formation on the fluid pressure distribution.

  16. Carbonized material adsorbents for the removal of mercury from aqueous solutions

    SciTech Connect

    NONE

    1996-10-01

    Charcoal in itself is porous making it an excellent material for activated charcoal manufacture. However, few studies have been conducted in harnessing its potential for adsorption purposes, especially in water treatment. This paper describes the possibility of utilizing charcoal materials from Sugi (Cryptomeria japonica) for adsorbing heavy metals like mercury from aqueous solutions of different concentrations. The effect of soaking time, pore analyses and chemical properties on the adsorption capabilities of the carbonized materials were discussed. The pH value and chemical oxygen demand (COD) monitored during the soaking period were also described.

  17. TRUCK WASHING TERMINAL WATER POLLUTION CONTROL

    EPA Science Inventory

    A laboratory and pilot-scale investigation of a treatment sequence, including physical, chemical, and biological treatment steps led to a full-scale installation for the treatment of tank truck washing wastewater. The system included gravity separation, equalization, neutralizati...

  18. Wash water waste pretreatment system study

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The use of real wash water had no adverse effect on soap removal when an Olive Leaf soap based system was used; 96 percent of the soap was removed using ferric chloride. Numerous chemical agents were evaluated as antifoams for synthetic wash water. Wash water surfactants used included Olive Leaf Soap, Ivory Soap, Neutrogena and Neutrogena Rain Bath Gel, Alipal CO-436, Aerosol 18, Miranol JEM, Palmeto, and Aerosol MA-80. For each type of soapy wash water evaluated, at least one antifoam capable of causing nonpersistent foam was identified. In general, the silicones and the heavy metal ions (i.e., ferric, aluminum, etc.) were the most effective antifoams. Required dosage was in the range of 50 to 200 ppm.

  19. Chemical changes at the interface between low carbon steel and an Al-Si alloy during solution heat treatment

    E-print Network

    Paris-Sud XI, Université de

    of aluminium-silicon alloy castings consists in reinforcing them locally with steel or cast iron inserts1 Chemical changes at the interface between low carbon steel and an Al-Si alloy during solution the chemical changes during solid state solution heat treatment of a metallurgically bonded steel

  20. Comparison of activated carbon and bottom ash for removal of reactive dye from aqueous solution.

    PubMed

    Dinçer, Ali Riza; Güne?, Yalçin; Karakaya, Nusret; Güne?, Elçin

    2007-03-01

    The adsorption of reactive dye from synthetic aqueous solution onto granular activated carbon (GAC) and coal-based bottom ash (CBBA) were studied under the same experimental conditions. As an alternative to GAC, CBBA was used as adsorbent for dye removal from aqueous solution. The amount of Vertigo Navy Marine (VNM) adsorbed onto CBBA was lower compared with GAC at equilibrium and dye adsorption capacity increased from 0.71 to 3.82 mg g(-1), and 0.73 to 6.35 mg g(-1) with the initial concentration of dye from 25 to 300 mg l(-1), respectively. The initial dye uptake of CBBA was not so rapid as in the case of GAC and the dye uptake was slow and gradually attained equilibrium. PMID:16697184

  1. Removal of trihalomethanes from aqueous solution through armchair carbon nanotubes: A molecular dynamics study.

    PubMed

    Azamat, Jafar; Khataee, Alireza; Joo, Sang Woo; Yin, Binfeng

    2015-04-01

    Molecular dynamics simulations were performed to investigate the removal of trihalomethanes (THMs) including CH3Cl, CH2Cl2 and CHCl3 from aqueous solutions by armchair carbon nanotubes (CNTs) under induced pressure. The studied system involved the armchair CNTs embedded between two graphene sheets with an aqueous solution of THMs in the simulation box. An external pressure was applied to the system along the z-axis of the simulation box. Six types of armchair CNTs with different diameter were used in this work, included (4,4), (5,5), (6,6), (7,7), (8,8) and (9,9) CNTs. The results of molecular dynamics simulation display that the armchair CNTs behave differently relative to THMs and water molecules. The permeation of THMs and water molecules through the armchair CNTs was dependent on the diameter of CNTs and the applied pressure. PMID:25682360

  2. Synthesis of finely divided molybdenum sulfide nanoparticles in propylene carbonate solution

    NASA Astrophysics Data System (ADS)

    Afanasiev, Pavel

    2014-05-01

    Molybdenum sulfide nanoparticles have been prepared from the reflux solution reaction involving ammonium heptamolybdate and elemental sulfur in propylene carbonate. Addition to the reaction mixture of starch as a natural capping agent leads to lesser agglomeration and smaller size of the particles. Nanoparticles of MoSx (x?4) of 10-30 nm size are highly divided and form stable colloidal suspensions in organic solvents. Mo K edge EXAFS of the amorphous materials shows rapid exchange of oxygen to sulfur in the molybdenum coordination sphere during the solution reaction. Thermal treatment of the amorphous sulfides MoSx under nitrogen or hydrogen flow at 400 °C allows obtaining mesoporous MoS2 materials with very high pore volume and specific surface area, up to 0.45 cm3/g and 190 m2/g, respectively. The new materials show good potential for the application as unsupported hydrotreating catalysts.

  3. Surface activated carbon nanospheres for fast adsorption of silver ions from aqueous solutions.

    PubMed

    Song, Xianghua; Gunawan, Poernomo; Jiang, Rongrong; Leong, Susanna Su Jan; Wang, Kean; Xu, Rong

    2011-10-30

    We report the synthesis and activation of colloidal carbon nanospheres (CNS) for adsorption of Ag(I) ions from aqueous solutions. CNS (400-500 nm in diameter) was synthesized via simple hydrothermal treatment of glucose solution. The surface of nonporous CNS after being activated by NaOH was enriched with -OH and -COO(-) functional groups. Despite the low surface area (<15m(2)/g), the activated CNS exhibited a high adsorption capacity of 152 mg silver/g. Under batch conditions, all Ag(I) ions can be completely adsorbed in less than 6 min with the initial Ag(I) concentrations lower than 2 ppm. This can be attributed to the minimum mass transfer resistance as Ag(I) ions were all deposited and reduced as Ag(0) nanoparticles on the external surface of CNS. The kinetic data can be well fitted to the pseudo-second-order kinetics model. The adsorbed silver can be easily recovered by dilute acid solutions and the CNS can be reactivated by the same treatment with NaOH solution. The excellent adsorption performance and reusability have also been demonstrated in a continuous mode. The NaOH activated CNS reported here could represent a new type of low-cost and efficient adsorbent nanomaterials for removal of trace Ag(I) ions for drinking water production. PMID:21862215

  4. Carbon Dioxide Emissions From Illuminated Frozen Pyruvic Acid Solutions Above Minus 140 Celsius

    NASA Astrophysics Data System (ADS)

    Guzman, M. I.; Colussi, A. J.; Hoffmann, M. R.

    2005-12-01

    Photodecarboxylation rates of deareated aqueous pyruvic acid solutions drop by a factor of two in the frozen state at 253 K relative to the fluid at 293 K. TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl), in contrast with experiments in water, has no effect on photodecarboxylation rates in ice. Preirradiated frozen pyruvic acid (PA) solutions still release carbon dioxide (CD)in the dark at rates that increase with temperature (Ea = 22 kJ/mol, below 268 K), but which extrapolate into measurable rates in fluid solutions, at variance with observations. We verified the absence of post-illumination CD emissions in the concerted photodecomposition of benzoylformic acid in frozen solutions. We infer that PA rapidly photodecarboxylates into intermediates that slowly yield further CD via a thermally activated process. Prompt CD is apparently formed even at cryogenic temperatures, although is only able to sublimate above -140 Celsius. The detection of distant triplet radical pairs in ice below 190 K via electron paramagnetic resonance spectrometry indicates that the primary process in the photodecarboxylation of pyruvic acid involves photoinduced charge transfer between the carbonyl groups of H-bonded PA dimers into triplet [PA- PA+], followed by ultrafast deprotonation/decarboxylation of the radical cation PA+. The radical anion PA- readily protonates into an alkoxyl radical to initiate polymerizations.

  5. Electrochemical behavior of glassy carbon electrodes modified by multi-walled carbon nanotube\\/surfactant films in a buffer solution and an ionic liquid

    Microsoft Academic Search

    Yi Li; Xingwang Shi; Jingcheng Hao

    2006-01-01

    The electrochemical behavior of glassy carbon (GC) electrodes coated with multi-walled carbon nanotube (MWCNT)\\/surfactant films was studied in an ionic liquid and a phosphate buffer solution (pH=6.86), using cyclic voltammetry. The dispersion of MWCNTs in different media was investigated by scanning and transmission electron microscopy. Cast films of MWCNT\\/zwitterionic dodecyldimethylamine oxide on a GC electrode show a typical redox couple

  6. Metastable Equilibrium Solubility Behavior of Carbonated Apatites in the Presence of Solution Fluoride.

    PubMed

    Zhuang; Baig; Fox; Wang; Colby; Chhettry; Higuchi

    2000-02-01

    The aims of the present investigation were to assess the applicability of the metastable equilibrium solubility (MES) concept for the carbonated apatites (CAPs) over a range of pH and a wide range of solution fluoride concentrations and to examine the hypothesis that, in the presence of solution fluoride, a surface complex with the stoichiometry of fluorapatite (FAP) governs the MES behavior. Two CAP samples were prepared by precipitation from reaction media containing calcium nitrate (Ca(NO(3))(2).4H(2)O) and sodium phosphate (NaH(2)PO(4).H(2)O) at two different levels of sodium bicarbonate. The MES distributions of the two CAP preparations were determined by equilibrating approximately 10 mg of CAP powder in 2 L of 0.1 M acetate buffers (ionic strength=0.50 M) at pH 4.5 and 5.5 and at various levels of calcium, phosphate, and fluoride. The fluoride concentrations ranged from 0.03 to 12 ppm. From the compositions of the equilibrating buffer solutions, ion activity products based upon the stoichiometries of hydroxyapatite (HAP) and FAP were calculated in an attempt to determine the correct function governing the dissolution of the CAP preparations. The results of this study demonstrated that both CAP preparations exhibit the MES distribution phenomenon in solution media of varying pH and fluoride concentrations. Furthermore, the experimental MES data obtained with both CAP preparations at the lower pH (4.5) and at higher solution fluoride levels (>/=0.1 ppm) were essentially superimposable when plotted against the ion activity product based upon the stoichiometry of FAP, suggesting that in the presence of solution fluoride the MES governing surface complex may be an entity possessing a stoichiometry approximated by that of FAP. When the HAP stoichiometry was assumed to represent the surface complex, good superposition of the data was not possible. Copyright 2000 Academic Press. PMID:10655129

  7. Surface modification of carbon nanotubes for enhancing BTEX adsorption from aqueous solutions

    NASA Astrophysics Data System (ADS)

    Lu, Chungsying; Su, Fengsheng; Hu, Suhkai

    2008-08-01

    Carbon nanotubes (CNTs) were fabricated by the catalytic chemical vapor deposition method and oxidized by HCl, H 2SO 4, HNO 3 and NaOCl solutions for enhancing benzene, toluene, ethylbenzene and p-xylene (BTEX) adsorption in an aqueous solution. The surface nature of CNTs was changed after the H 2SO 4, HNO 3 and NaOCl oxidation, which makes CNTs that adsorb more BTEX. The NaOCl-oxidized CNTs show the greatest enhancement in BTEX adsorption, followed by the HNO 3-oxidized CNTs, and then the H 2SO 4-oxidized CNTs. The adsorption mechanism of BTEX via CNTs is mainly attributed to the ?-? electron-donor-acceptor interaction between the aromatic ring of BTEX and the surface carboxylic groups of CNTs. The NaOCl-oxidized CNTs have superior adsorption performance of BTEX as compared to many types of carbon and silica adsorbents reported in the literature. This suggests that the NaOCl-oxidized CNTs are efficient BTEX adsorbents and that they possess good potential applications for BTEX removal in wastewater treatment.

  8. Dissolved organic carbon in soil solution of peat-moorsh soils on Kuwasy Mire

    NASA Astrophysics Data System (ADS)

    Jaszczy?ski, J.; Sapek, A.

    2009-04-01

    Key words: peat-moorsh soils, soil solution, dissolved organic carbon (DOC), temperature of soil, redox potential. The objective this study was the dissolved organic carbon concentration (DOC) in soil solution on the background of soil temperature, moisture and redox potential. The investigations were localized on the area of drained and agricultural used Kuwasy Mire, which are situated in the middle basin of Biebrza River, in North-East Poland. Research point was placed on a low peat soil of 110 cm depth managed as extensive grassland. The soil was recognized as peat-moorsh with the second degree of the moorshing process (with 20 cm of moorsh layer). The ceramic suction cups were installed in three replications at 30 cm depth of soil profile. The soil solution was continuously sampled by pomp of the automatic field station. The successive samples comprised of solution collected at the intervals of 21 days. Simultaneously, at the 20, 30 and 40 cm soil depths the measurements of temperature and determination of soil moisture and redox potential were made automatically. The mean twenty-four hours data were collected. The concentrations of DOC were determined by means of the flow colorimeter using the Skalar standard methods. Presented observations were made in 2001-2006. Mean DOC concentration in soil solution was 66 mg.dm-3 within all research period. A significant positive correlation between studied compound concentration and temperature of soil at 30 cm depth was observed; (correlation coefficient - r=0.55, number of samples - n=87). The highest DOC concentrations were observed during the season from July to October, when also a lower ground water level occurred. The DOC concentration in soil solution showed as well a significant correlation with the soil redox potential at 20 cm level. On this depth of describing soil profile a frontier layer between moorshing layer and peat has been existed. This layer is the potentially most active in the respect to biochemical transformation. On the other hand it wasn't possible to shown dependences on the DOC concentration from soil moisture. That probably results from a huge water-holding capacity of these type of peat soils, which are keeping a high moisture content even at a long time after decreasing of the groundwater table.

  9. [Studies on carbonization of saccharides by using aqueous solution of various acids].

    PubMed

    Zhang, Xin; He, An-Qi; Kang, Ting-Guo; Xia, Jin-Ming; Weng, Shi-Fu; Xu, Yi-Zhuang; Wu, Jin-Guang

    2014-09-01

    The authors tried to establish an approach to use acids to convert biomass into a fuel with higher carbon content and lower oxygen content in a zero-energy-consumption fashion. Considering that biomass is composed of monosaccharide, we used aqueous solutions of variation acids including hydrochloric acid, sulfuric acid and perchloric acid to treat 2-deoxy-ribose and fructose at ambient temperature and pressure. Black substances were produced after a period of time when 2-deoxy-ribose and fructose were mixed with aqueous solutions containing 8 mol · L(-1) acids. The black substance was collected and characterized by using elemental analysis, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Elemental analysis results indicate that the contents of carbon increases significantly in the black substances in comparison with 2-deoxy-ribose and fructose. Moreover, XPS results indicate that the content of oxygen in the black substance undergoes a significant decrease compared with pure 2-deoxy-ribose and fructose. In the XPS spectra, the is peaks of 2-deoxy-ribose, strong sub peak at 286. 05 eV, which is assigned to carbon linked to oxygen directly, dominate in the C is peak envelop. After treatment by HClO4, the peak decreased dramatically. This result also supports the conclusion that the content of oxygen in mono-saccharide is significantly reduced after treatment by acids. In the FTIR spectra of the black substances, strong peaks can be observed around 1 600 cm(-1), indicating that C==C bond is formed in the product. The above results suggest that treatments with acids may be developed as a new zero-energy-consumption approach to convert biomass in a new fuel with improved energy output efficiency. PMID:25532323

  10. Opportunities for Energy Conservation and Improved Comfort From Wind Washing Retrofits in Two-Story Homes - Part I

    E-print Network

    Withers, C. R. Jr.; Cummings, J. B.

    of wind washing found in this study. Repairs and energy monitoring were completed in six of these homes to evaluate retrofit methods and cost effectiveness of retrofit solutions. These results are discussed in Part II of this paper....

  11. Domestic wash water reclamation for reuse as commode water supply using filtration: Reverse-osmosis separation technique

    NASA Technical Reports Server (NTRS)

    Hall, J. B., Jr.; Batten, C. E.; Wilkins, J. R.

    1974-01-01

    A combined filtration-reverse-osmosis water recovery system has been evaluated to determine its capability to reclaim domestic wash water for reuse as a commode water supply. The system produced water that met all chemical and physical requirements established by the U.S. Public Health Service for drinking water with the exception of carbon chloroform extractables, methylene blue active substances, and phenols. It is thought that this water is of sufficient quality to be reused as commode supply water. The feasibility of using a combined filtration and reverse-osmosis technique for reclaiming domestic wash water has been established. The use of such a technique for wash-water recovery will require a maintenance filter to remove solid materials including those less than 1 micron in size from the wash water. The reverse-osmosis module, if sufficiently protected from plugging, is an attractive low-energy technique for removing contaminants from domestic wash water.

  12. Linking mineralisation process and sedimentary product in terrestrial carbonates using a solution thermodynamic approach

    NASA Astrophysics Data System (ADS)

    Rogerson, M.; Pedley, H. M.; Kelham, A.; Wadhawan, J. D.

    2014-04-01

    Determining the processes which generate terrestrial carbonate deposits (tufas, travertines and to a lesser extent associated chemical sediments such as calcretes and speleothems) is a long-standing problem. Precipitation of mineral products from solution reflects a complex combination of biological, equilibrium and kinetic processes, and the different morphologies of carbonate sediment produced by different processes have yet to be clearly demarked. Building on the groundbreaking work of previous authors, we propose that the underlying control on the processes leading to the deposition of these products can be most parsimoniously understood from the thermodynamic properties of their source solutions. Here, we report initial observations of the differences in product generated from spring and lake systems spanning a range of temperature-supersaturation space. We find that at high supersaturation, biological influences are masked by high rates of physico-chemical precipitation, and sedimentary products from these settings infrequently exhibit classic "biomediated" fabrics such as clotted micrite. Likewise, at high temperature (>40 °C) exclusion of vascular plants and complex/diverse biofilms can significantly inhibit the magnitude of biomediated precipitation, again impeding the likelihood of encountering the "bio-type" fabrics. Conversely, despite the clear division in product between extensive tufa facies associations and less spatially extensive deposits such as oncoid beds, no clear division can be identified between these systems in temperature-supersaturation space. We reiterate the conclusion of previous authors, which demonstrate that this division cannot be made on the basis of physico-chemical characteristics of the solution alone. We further provide a new case study of this division from two adjacent systems in the UK, where tufa-like deposition continuous on a metre scale is happening at a site with lower supersaturation than other sites exhibiting only discontinuous (oncoidal) deposition. However, a strong microbiological division is demonstrated between these sites on the basis of suspended bacterial cell distribution, which reach a prominent maximum where tufa-like deposits are forming. We conclude that at high supersaturation, the thermodynamic properties of solutions provide a highly satisfactory means of linking process and product, raising the opportunity of identifying water characteristics from sedimentological/petrological characteristics of ancient deposits. At low supersaturation, we recommend that future research focuses on geomicrobiological processes rather than the more traditional, inorganic solution chemistry approach dominant in the past.

  13. Wash water reclamation technology for advanced manned spacecraft

    NASA Technical Reports Server (NTRS)

    Putnam, D. F.

    1977-01-01

    The results of an analytical study and assessment of state-of-the-art wash water reclamation technology for advanced manned spacecraft is presented. All non-phase-change unit operations, unit processes, and subsystems currently under development by NASA are considered. Included among these are: filtration, ultrafiltration, carbon adsorption, ion exchange, chemical pretreatment, reverse osmosis, hyperfiltration, and certain urea removal techniques. Performance data are given together with the projected weights and sizes of key components and subsystems. In the final assessment, a simple multifiltration approach consisting of surface-type cartridge filters, carbon adsorption and ion exchange resins receives the highest rating for six-man orbital missions of up to 10 years in duration.

  14. Adsorption of tetracycline from aqueous solutions onto multi-walled carbon nanotubes with different oxygen contents

    NASA Astrophysics Data System (ADS)

    Yu, Fei; Ma, Jie; Han, Sheng

    2014-06-01

    Oxidized multi-walled carbon nanotubes (MWCNTs) with different oxygen contents were investigated for the adsorption of tetracycline (TC) from aqueous solutions. As the surface oxygen content of the MWCNTs increased, the maximum adsorption capacity and adsorption coefficient of TC increased to the largest values and then decreased. The relation can be attributed to the interplay between the nanotubes' dispersibility and the water cluster formation upon TC adsorption. The overall adsorption kinetics of TC onto CNTs-3.2%O might be dependent on both intra-particle diffusion and boundary layer diffusion. The maximum adsorption capacity of TC on CNTs-3.2%O was achieved in the pH range of 3.3-8.0 due to formation of water clusters or H-bonds. Furthermore, the presence of Cu2+ could significantly enhanced TC adsorption at pH of 5.0. However, the solution ionic strength did not exhibit remarkable effect on TC adsorption. In addition, when pH is beyond the range (3.3-8.0), the electrostatic interactions caused the decrease of TC adsorption capacity. Our results indicate that surface properties and aqueous solution chemistry play important roles in TC adsorption on MWCNTs.

  15. Metastable intermediates from glassy solutions part 5: FTIR spectroscopic characterization of isolated ?- and ?-carbonic acid

    NASA Astrophysics Data System (ADS)

    Hage, Wolfgang; Hallbrucker, Andreas; Mayer, Erwin

    1997-06-01

    Layers of glassy aqueous or methanolic solutions of KH 12CO 3 (K 132CO 3) and of excess HCl or HBr have been deposited sequentially at 78 K in the form of droplets, and their reaction in the temperature range from 78 to 300 K studied by FTIR spectroscopy in the spectral range from 4000 to 400 cm -1. When using methanol as solvent, at ca. 20 K above its glass-transition temperature ( Tg), a decrease in viscosity initiated coalescence of the droplets. At ca. 40 K above Tg, protonation of {HCO-3}/{CO2-3} and formation of H 2CO 3 occurred in the liquid phase. After pumping off the solvent, residual ice and excess HCl, amorphous H 122CO 3 (H 132CO 3) was isolated, crystallizing at ca. 190-200 K to ?-carbonic acid. In the case of water as solvent, protonation of {HCO-3}/{CO2-3} apparently occurs in the freeze-concentrated state, after crystallization of glassy water to cubic ice. Reaction in freeze-concentrated aqueous solutions leads to formation of ?-H 2CO 3. This polymorphic form is the same product reported by Moore and Khanna for proton irradiation of cryogenic CO 2?H 2O mixtures (Spectrochim. Acta Part A, 1991, 47, 255). The cryogenic method is discussed for formation of metastable short-lived intermediates from reaction of non-volatile reactants, where the intermediates can be studied in solution or as amorphous or crystalline solids.

  16. Adsorption of tetracycline from aqueous solutions onto multi-walled carbon nanotubes with different oxygen contents

    PubMed Central

    Yu, Fei; Ma, Jie; Han, Sheng

    2014-01-01

    Oxidized multi-walled carbon nanotubes (MWCNTs) with different oxygen contents were investigated for the adsorption of tetracycline (TC) from aqueous solutions. As the surface oxygen content of the MWCNTs increased, the maximum adsorption capacity and adsorption coefficient of TC increased to the largest values and then decreased. The relation can be attributed to the interplay between the nanotubes' dispersibility and the water cluster formation upon TC adsorption. The overall adsorption kinetics of TC onto CNTs-3.2%O might be dependent on both intra-particle diffusion and boundary layer diffusion. The maximum adsorption capacity of TC on CNTs-3.2%O was achieved in the pH range of 3.3–8.0 due to formation of water clusters or H-bonds. Furthermore, the presence of Cu2+ could significantly enhanced TC adsorption at pH of 5.0. However, the solution ionic strength did not exhibit remarkable effect on TC adsorption. In addition, when pH is beyond the range (3.3–8.0), the electrostatic interactions caused the decrease of TC adsorption capacity. Our results indicate that surface properties and aqueous solution chemistry play important roles in TC adsorption on MWCNTs. PMID:24937315

  17. Transport of carbon, nitrogen, phosphorus, and major solutes in the Gambia River, West Africa

    SciTech Connect

    Lesack, L.F.W.; Hecky, R.E.; Melack, J.M.

    1984-07-01

    Transport of solutes and particulate materials and their variation with discharge were studied for 1 year (July 1980-June 1981) in the Gambia River in the tropical savanna of West Africa. The water is a dilute solution of SiO/sub 2/ and HCO/sub 3//sup -/. Na/sup +/, K/sup +/, Cl/sup -/, and total dissolved nitrogen showed no significant relation with discharge. Ca/sup 2 +/, Mg/sup 2 +/, HCO/sub 3//sup -/, conductivity, and SO/sub 4//sup 2 -/ decreased as discharge increased, while total dissolved phosphorus increased with discharge. After an initial increase SiO/sub 2/ was independent of discharge. Dissolved organic carbon displayed counterclockwise hysteresis with rising and falling discharge. Particulate phosphorus and total particulate materials displayed clockwise hysteresis. Total transport amounted to 9.66 t x km/sup -2/ x yr/sup -1/. The transport rates of both dissolved and particulate organic C are among the lowest ever reported. The low transport of total particulates and solutes is attributed to lack of relief and the lithology of the catchment.

  18. Catalytic ozonation of pentachlorophenol in aqueous solutions using granular activated carbon

    NASA Astrophysics Data System (ADS)

    Asgari, Ghorban; Samiee, Fateme; Ahmadian, Mohammad; Poormohammadi, Ali; solimanzadeh, Bahman

    2014-11-01

    The efficiency of granular activated carbon (GAC) was investigated in this study as a catalyst for the elimination of pentachlorophenol (PCP) from contaminated streams in a laboratory-scale semi-batch reactor. The influence of important parameters including solution pH (2-10), radical scavenger (tert-butanol, 0.04 mol/L), catalyst dosage (0.416-8.33 g/L), initial PCP concentration (100-1000 mg/L) and ozone flow rate (2.3-12 mg/min) was examined on the efficiency of the catalytic ozonation process (COP) in degradation and mineralization of PCP in aqueous solution. The experimental results showed that catalytic ozonation with GAC was most effective at pH of 8 with ozone flow rate of 12 mg/min and a GAC dosage of 2 g. Compared to the sole ozonation process (SOP), the removal levels of PCP and COP were, 98, and 79 %, respectively. The degradation rate of kinetics was also investigated. The results showed that using a GAC catalyst in the ozonation of PCP produced an 8.33-fold increase in rate kinetic compared to the SOP under optimum conditions. Tert-butanol alcohol (TBA) was used as a radical scavenger. The results demonstrated that COP was affected less by TBA than by SOP. These findings suggested that GAC acts as a suitable catalyst in COP to remove refractory pollutants from aqueous solution.

  19. Effects of impurities on the electroreduction of carbon dioxide on platinum electrodes in acid solutions

    SciTech Connect

    Huang, H. (Dept. of Chemistry, Case-Western Reserve Univ., Cleveland, OH (US))

    1992-02-01

    The electroreduction of carbon dioxide has been studied in this laboratory using electrochemical techniques and in situ Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) on both polycrystalline and single-crystalline platinum electrodes in 0.1M HClO{sub 4} solution. On polycrystalline electrodes and two single-crystalline planes ((110) and (100)), the reduction reaction proceeds in the hydrogen absorption region and gives rise the polycrystalline electrode and Pt(110), and bridge-bonded Co on Pt(100). No. CO was detected on Pt(111). The introduction of CO{sub 2} in solution shows a similar effect on the Butterfly peaks of Pt(111) to that of specifically adsorbed anions, such as bisulfate. The has been attributed tentatively to the absorption of HCO{sub 3} in the potential region between the onset of the butterfly peaks and the formation of oxide. The IR absorption peak between 1418 and 1456 cm{sup {minus}1}, which is assigned to the absorbed HCO{sub 3}{sup {minus}}, shows a large positive shift with increasing potential (127 cm{sup {minus}1}/V). As part of the research on CO{sub 2} reduction, this paper examines the effects of impurities (Cl{sup {minus}}) and electrode rotation rates on Co{sub 2} reduction on polycrystalline Pt electrodes in 0.1M HClO{sub 4} solutions.

  20. Technical bases DWPF Late Washing Facility

    SciTech Connect

    Fish, D.L.; Landon, L.F.

    1992-08-10

    A task force recommended that the technical feasibility of a Late Wash' facility be assessed [1]. In this facility, each batch of tetraphenylborate slurry from Tank 49 would be given a final wash to reduce the concentrations of nitrite and radiolysis products to acceptable levels. Laboratory-scale studies have demonstrated that d the nitrite content of the slurry fed to DWPF is reduced to 0.01 M or less (and at least a 4X reduction in concentration of the soluble species is attained), (1) the need for HAN during hydrolysis is eliminated (eliminating the production of ammonium ion during hydrolysis), (2) hydrolysis may be done with a catalyst concentration that will not exceed the copper solubility in glass and (3) the non-polar organic production during hydrolysis is significantly reduced. The first phase of an aggressive research and development program has been completed and all test results obtained to date support the technical feasibility of Late Washing. Paralleling this research and development effort is an aggressive design study directed by DWPF to scope and cost retrofitting the Auxiliary Pump Pit (APP) to enable performing a final wash of each batch of precipitate slurry before R is transferred into the DWPF Soft Processing Cell (SPC). An initial technical bases for the Late Wash Facility was transmitted to DWPF on June 15, 1992. Research and development activities are continuing directed principally at optimization of the cross-f low fitter decontamination methodology and pilot-scale validation of the recommended benzene stripping metodology.

  1. Crevice corrosion behavior of A516-70 carbon steel in solutions containing inhibitors and chloride ions

    Microsoft Academic Search

    M. Z Yang; M Wilmott; J. L Luo

    1998-01-01

    Fluctuations of the corrosion potential and current were analyzed in the time domain for type A516-70 carbon steel immersed in 0.5 M NaHCO3 or 0.1% NaNO2 solutions containing NaCl at various concentrations. The fluctuations of corrosion potential and current observed for pitting corrosion showed a pattern distinctly different from that for crevice corrosion of this type of carbon steel immersed

  2. Oxidation of single-walled carbon nanotubes in dilute aqueous solutions by ozone as affected by ultrasound

    Microsoft Academic Search

    Minghua Li; Mary Boggs; Thomas P. Beebe; C. P. Huang

    2008-01-01

    A clean and simple wet chemical process using dilute aqueous ozone (O3) solution with or without ultrasound (US) was used to functionalize single-walled carbon nanotubes (SWCNTs). Both O3 and O3\\/US treatments greatly increased the stability of SWCNTs in water. Results of X-ray photoelectron spectroscopy (XPS) showed that the surface oxygen to carbon atomic ratio increased by more than 600% after

  3. Wash solvent reuse in paint production

    SciTech Connect

    Parsons, A.B.; Heater, K.J.; Olfenbuttel, R.F.

    1994-04-01

    The project evaluated solvent used to clean paint manufacture equipment for its utility in production of subsequent batches of solvent-borne paint. Reusing wash solvent would reduce the amount of solvent disposed of as waste. The evaluation of this wash-solvent recovery technology was conducted by Battelle Memorial Institute for the Pollution Prevention Research Branch of the U.S. Environmental Protection Agency. The evaluation was conducted with the cooperation and assistance of Vanex Color, Inc. The product quality, waste reduction/pollution prevention, and economic impacts of this technology change, as it has been implemented by Vanex, were examined. Two batches of a solvent-borne alkyd house paint were prepared at Vanex--one batch made with 100%-new solvent and the other with 30%-wash solvent--and sampled for laboratory analysis at Battelle.

  4. Carbon Monoxide Saturated Preservation Solution Protects Lung Grafts From Ischemia-Reperfusion Injury

    PubMed Central

    Kohmoto, Junichi; Nakao, Atsunori; Sugimoto, Ryujiro; Wang, Yinna; Zhan, JiangHua; Ueda, Hideo; McCurry, Kenneth R.

    2008-01-01

    Objectives In previous work, we have demonstrated that delivery of low concentrations (250 ppm) of carbon monoxide (CO) via inhalation to donor and/or recipients protects transplanted lungs from ischemia-reperfusion injury (IRI) (improved gas exchange, diminished intragraft and systemic inflammation and retention of graft vascular endothelial cell ultrastructure). In this study we examined whether delivery of CO to lung grafts in the preservation solution could protect against lung IRI. Methods Orthotopic left lung transplantation was performed in syngeneic Lewis to Lewis rats. Grafts were preserved in UW solution with (CO-UW) or without (control UW) CO at 4°C for 6 hours. CO gas (5% or 100%) was bubbled into UW solution at 4°C for 5 minutes before use. Results In controls, IR injury resulted in significant deterioration of graft function and was associated with a massive cellular infiltrate 2 hours after reperfusion. Grafts stored in CO-UW (5%), however, demonstrated significantly better gas exchange and significantly reduced intragraft inflammation (reduced inflammatory mediators and cellular infiltrate). Experiments demonstrated that the protective effects afforded by 100% CO-UW were not as potent as those of 5% CO-UW. Conclusions This study demonstrates that 5% CO as an additive to the cold flush/preservation solution can impart potent anti-inflammatory and cytoprotective effects following cold preservation and transplantation of lung grafts. Such ex vivo treatment of lung grafts with CO can minimize concerns associated with CO inhalation and may offer opportunity to significantly advance the application of CO in the clinical setting. PMID:18954651

  5. Water movement and solute transport in permafrost wetlands: implications for inorganic carbon cycling

    NASA Astrophysics Data System (ADS)

    Jessen, Søren; Dahl Holmslykke, Hanne; Rasmussen, Kristine; Richardt, Niels; Engelund Holm, Peter

    2014-05-01

    Carbon dioxide emissions from thawing permafrost wetlands are an expected consequence of global warming. Addressing the pathways by which carbon is emitted, we investigated the hydrological and geochemical controls on the pore water chemistry of a permafrost wetland, with a shallow geological sequence comprising loam overlain by sphagnum peat, in Ilulissat, Greenland. A 400 m transect parallel to the general flow direction was established, along which water table measurements and slug tests were conducted, and the active layer thickness recorded (typically ~0.5 m). Also, in three detailed profiles along the transect, the vertical distributions of stable isotopes of water and major ion chemistry were investigated, by analysis of active layer pore water and water of melted core sections of permafrost. Concentrations of chloride (0.3-0.4 mM) did not show variation with depth, dismissing solute movement by ion freeze-out during fall freeze-up as a main control on the water chemistry. In addition, the observed vertical ?18O distribution did not to any extent conform to modelled Rayleigh distillation curves for the preferential inclusion of H218O into ice, which could be a scenario for fall freeze-up. The ?18O data therefore suggests either a rapid freeze-up or a simultaneous phase transition at all depths of the active layer, which in either case also would minimize potential ion freeze-out effects. Nevertheless, concentrations of major ions generally increased with depth. A conceptual model for water and solute transport was therefore established, according to which solutes are mobilized by weathering reactions in the loam and then transported upwards to the peat by diffusion. In the peat, lateral advective solute transport dominates. We applied the model to observed profiles of Ca, Mg, HCO3 and the partial CO2 pressure (PCO2). Concentrations of Ca, Mg and HCO3 increased with depth, reaching ~2 mM, ~2 mM and ~8 meq/L at the bottom of the active layer. Pore water at all depths was of Ca-Mg-HCO3 type (1:1:4 stoichiometry), and was subsaturated for calcite and dolomite. Immediately below the permafrost table, however, Ca, Mg and HCO3 showed an abrupt decrease. Similarly, highly elevated PCO2 of up to 1.8 atm were observed in the active layer, followed by an abrupt decrease to

  6. Hybrid transparent electrodes of silver nanowires and carbon nanotubes: a low-temperature solution process

    PubMed Central

    2012-01-01

    Hybrid transparent electrodes with silver nanowires (AgNWs) and single-walled carbon nanotubes (SWCNTs) were fabricated on plastic films by a low-temperature solution process. The hybrid transparent electrodes exhibited a sheet resistance of 29.2 ?/sq with a transparency of 80% when 6 wt.% of SWCNTs was mixed with AgNWs. This sheet resistance was less than one-fourth that of the AgNW transparent electrodes that were prepared using the same method. This reduction in sheet resistance is because the SWCNTs formed bridges between the AgNWs, thus, resulting in high conductivity of the hybrid transparent electrodes. The hybrid electrodes formed on plastic films exhibited high conductivity as well as excellent stability in sheet resistance when tested using a repeated bending test. PACS: 62.23.Hj; 61.48.De; 81.15.-z. PMID:22650906

  7. Surface decoration and dispersibility of carbon nanofibers in aqueous surfactant solution

    NASA Astrophysics Data System (ADS)

    Wang, B. M.; Zhang, Y.; Liu, S.

    2014-03-01

    As a novel functional nanomaterial, the dispersion effect of carbon nanofibers (CNFs) has a significant influence on the application of CNFs in the composites. Two effective surfactants, methylcellulose (MC) and polycarboxylate superplasticizer, were used to analyze the dispersion of CNFs in aqueous solution. A method utilizing ultrasonic processing was employed to achieve a homogenous CNF suspension, and the dispersion effect was further characterized by the method of measuring ultraviolet absorbency (UV absorbency), zeta potential, surface tension and transmission electron microscopy (TEM) micrographs. The results show that the zeta potential and surface tension reach the saturation plateau at MC concentration and polycarboxylate superplasticizer concentration of about 0.4 and 0.8 g/L, respectively, which reflects that the optimum concentration ratio of MC to CNFs is 2: 1, and the optimum dispersing polycarboxylate superplasticizer to CNFs ratio of 4: 1 is required to achieve dispersions with maximum achievable dispersion of CNFs.

  8. Adsorption of fluoranthene in surfactant solution on activated carbon: equilibrium, thermodynamic, kinetic studies.

    PubMed

    Liu, Jianfei; Chen, Jiajun; Jiang, Lin; Wang, Xingwei

    2014-02-01

    Adsorption of fluoranthene (FLA) in surfactant solution on activated carbon (AC) was investigated. Isotherm, thermodynamic, and kinetic attributes of FLA adsorption in the presence of the surfactant on AC were studied. Effects of AC dosage, initial concentration of TX100, initial concentration of FLA, and addition of fulvic acid on adsorption were studied. The experimental data of both TX100 and FLA fitted the Langmuir isotherm model and the pseudo-second-order kinetic model well. Positive enthalpy showed that adsorption of FLA on AC was endothermic. The efficiency of selective FLA removal generally increased with increasing initial surfactant concentration and decreasing fulvic acid concentration. The surface chemistry of AC may determine the removal of polycyclic aromatic hydrocarbons. The adsorption process may be controlled by the hydrophobic interaction between AC and the adsorbate. The microwave irradiation of AC may be a feasible method to reduce the cost of AC through its regeneration. PMID:23979852

  9. Titanium Implant Osseointegration Problems with Alternate Solutions Using Epoxy/Carbon-Fiber-Reinforced Composite

    PubMed Central

    Petersen, Richard C.

    2014-01-01

    The aim of the article is to present recent developments in material research with bisphenyl-polymer/carbon-fiber-reinforced composite that have produced highly influential results toward improving upon current titanium bone implant clinical osseointegration success. Titanium is now the standard intra-oral tooth root/bone implant material with biocompatible interface relationships that confer potential osseointegration. Titanium produces a TiO2 oxide surface layer reactively that can provide chemical bonding through various electron interactions as a possible explanation for biocompatibility. Nevertheless, titanium alloy implants produce corrosion particles and fail by mechanisms generally related to surface interaction on bone to promote an inflammation with fibrous aseptic loosening or infection that can require implant removal. Further, lowered oxygen concentrations from poor vasculature at a foreign metal surface interface promote a build-up of host-cell-related electrons as free radicals and proton acid that can encourage infection and inflammation to greatly influence implant failure. To provide improved osseointegration many different coating processes and alternate polymer matrix composite (PMC) solutions have been considered that supply new designing potential to possibly overcome problems with titanium bone implants. Now for important consideration, PMCs have decisive biofunctional fabrication possibilities while maintaining mechanical properties from addition of high-strengthening varied fiber-reinforcement and complex fillers/additives to include hydroxyapatite or antimicrobial incorporation through thermoset polymers that cure at low temperatures. Topics/issues reviewed in this manuscript include titanium corrosion, implant infection, coatings and the new epoxy/carbon-fiber implant results discussing osseointegration with biocompatibility related to nonpolar molecular attractions with secondary bonding, carbon fiber in vivo properties, electrical semiconductors, stress transfer, additives with low thermal PMC processing and new coating possibilities. PMID:25635227

  10. Removal of lead from solution using non-living residual brewery yeast

    Microsoft Academic Search

    C. Riordan; A. P. McHale

    1998-01-01

    A number of preparations of residual non-living brewery yeast were examined for their ability to remove lead from solution. Those preparations included washed and un-washed intact yeast and washed and un-washed homogenates of the yeast cells. Using biosorption isotherm analysis it was found that the washed and un-washed preparations of intact, non-living yeast exhibited maximum biosorption capacities for lead of

  11. Ca-Rich Carbonate Melts: A Regular-Solution Model, with Applications to Carbonatite Magma + Vapor Equilibria and Carbonate Lavas on Venus

    NASA Technical Reports Server (NTRS)

    Treiman, Allan H.

    1995-01-01

    A thermochemical model of the activities of species in carbonate-rich melts would be useful in quantifying chemical equilibria between carbonatite magmas and vapors and in extrapolating liquidus equilibria to unexplored PTX. A regular-solution model of Ca-rich carbonate melts is developed here, using the fact that they are ionic liquids, and can be treated (to a first approximation) as interpenetrating regular solutions of cations and of anions. Thermochemical data on systems of alkali metal cations with carbonate and other anions are drawn from the literature; data on systems with alkaline earth (and other) cations and carbonate (and other) anions are derived here from liquidus phase equilibria. The model is validated in that all available data (at 1 kbar) are consistent with single values for the melting temperature and heat of fusion for calcite, and all liquidi are consistent with the liquids acting as regular solutions. At 1 kbar, the metastable congruent melting temperature of calcite (CaCO3) is inferred to be 1596 K, with (Delta)bar-H(sub fus)(calcite) = 31.5 +/- 1 kJ/mol. Regular solution interaction parameters (W) for Ca(2+) and alkali metal cations are in the range -3 to -12 kJ/sq mol; W for Ca(2+)-Ba(2+) is approximately -11 kJ/sq mol; W for Ca(2+)-Mg(2+) is approximately -40 kJ/sq mol, and W for Ca(2+)-La(3+) is approximately +85 kJ/sq mol. Solutions of carbonate and most anions (including OH(-), F(-), and SO4(2-)) are nearly ideal, with W between 0(ideal) and -2.5 kJ/sq mol. The interaction of carbonate and phosphate ions is strongly nonideal, which is consistent with the suggestion of carbonate-phosphate liquid immiscibility. Interaction of carbonate and sulfide ions is also nonideal and suggestive of carbonate-sulfide liquid immiscibility. Solution of H2O, for all but the most H2O-rich compositions, can be modeled as a disproportionation to hydronium (H3O(+)) and hydroxyl (OH(-)) ions with W for Ca(2+)-H3O(+) (approximately) equals 33 kJ/sq mol. The regular-solution model of carbonate melts can be applied to problems of carbonatite magma + vapor equilibria and of extrapolating liquidus equilibria to unstudied systems. Calculations on one carbonatite (the Husereau dike, Oka complex, Quebec, Canada) show that the anion solution of its magma contained an OH mole fraction of (approximately) 0.07, although the vapor in equilibrium with the magma had P(H2O) = 8.5 x P(CO2). F in carbonatite systems is calculated to be strongly partitioned into the magma (as F(-)) relative to coexisting vapor. In the Husereau carbonatite magma, the anion solution contained an F(-) mole fraction of (approximately) 6 x 10(exp -5).

  12. Spectroscopic and electrochemical studies of selected lanthanides and actinides in concentrated aqueous carbonate and carbonate-hydroxide solutions and in molten dimethyl sulfone

    SciTech Connect

    Varlashkin, P.G.

    1985-03-01

    Electrochemical and spectroscopic studies of neptunium, plutonium, americium, californium, and terbium in concentrated aqueous carbonate and carbonate-hydroxide solutions have been carried out. Changes in the absorption spectra of Np(VII), Np(V), Pu(VI), Pu(V), Am(VI), and Am(V) in concentrated Na/sub 2/CO/sub 3/ solution and in the formal potentials of the Np(VI)/Np(V) and Pu(VI)/Pu(V) couples as a function of pH were observed. Heptavalent neptunium in concentrated Na/sub 2/CO/sub 3/ solution could only be producted at pH values close to or greater than 14. Plutonium(VII) in 2 M Na/sub 2/CO/sub 3/ solution could only be produced at hydroxide ion concentrations in excess of about 2.5 M. The complexation of Np(VII) and Pu(VII) in Na/sub 2/CO/sub 3/-NaOH solution seems to be mainly by hydroxide ions. Neptunium(IV) and plutonium(IV) are insoluble in Na/sub 2/CO/sub 3/ solution above ca. pH 11-12. Neptunium(III) in carbonate solution is rapidly oxidized by water to Np(IV). Plutonium(III) is insoluble in Na/sub 2/CO/sub 3/ solution. In K/sub 2/CO/sub 3/ solution Pu(III) is stable to oxidation by water but is very sensitive to air oxidation. The redox properties of Cf(III) in Na/sub 2/CO/sub 3/ and K/sub 2/CO/sub 3/ solutions at pH values from 8 to 14 were investigated. The oxidation of terbium(III) in K/sub 2/CO/sub 3/-KOH solution was studied. Spectroscopic and electrochemical studies of cerium, samarium, europium, ytterbium, uranium, neptunium, plutonium, and americium in molten dimethyl sulfone (DMSO/sub 2/) at 400 K were performed. Differences in the DMSO/sub 2/ solution absorption spectra of trivalent Sm, Eu, and Yb and divalent Eu compared with those in aqueous solution were observed. Complexation effects on the spectra of Ce(III), Ce(IV), U(VI), Np(VI), Pu(VI), and Am(VI) are more noticeable in poorly coordinating DMSO/sub 2/ than they are in water. 123 references, 54 figures, 11 tables.

  13. Accelerated carbonation of Friedel's salt in calcium aluminate cement paste

    SciTech Connect

    Goni, S.; Guerrero, A

    2003-01-01

    The stability of Friedel's salt with respect to carbonation has been studied in calcium aluminate cement (CAC) pastes containing NaCl (3% of Cl{sup -} by weight of cement). Carbonation was carried out on a powdered sample in flowing 5% CO{sub 2} gas at 65% relative humidity to accelerate the process. At an intermediate carbonation step, a part of the sample was washed and dried up to 10 cycles to simulate a dynamic leaching attack. The two processes were followed by means of X-ray diffraction (XRD), pH and Cl{sup -} analyses in the simulated pore solution.

  14. Self-assembly of fluorescent carbon dots in a N,N-dimethylmethanamide solution via Schiff base reaction

    NASA Astrophysics Data System (ADS)

    Hu, Shengliang; Ding, Yanli; Chang, Qing; Trinchi, Adrian; Lin, Kui; Yang, Jinlong; Liu, Jun

    2015-02-01

    The transition from nanoparticles suspended in aqueous solutions into solid fluorescent structures is developed for application in solid functional devices. The presented approach enables the organization of carbon dots into rod-like shapes that can still be re-dispersed into aqueous solution. Schiff bases forming at the surface of carbon dots not only protect their surface states, but also provide sites for tethering to other carbon dots. As a consequence, the large assemblies of CDs can come together to form regular, well ordered structures whilst still maintaining their photoluminescence properties. This opens up enormous possibilities for device manufacture, as these self-assemblies could be grown or grafted onto templates forming regular structures, and find innumerable applications ranging from optoelectronic devices, light harvesting to artificial photosynthesis.The transition from nanoparticles suspended in aqueous solutions into solid fluorescent structures is developed for application in solid functional devices. The presented approach enables the organization of carbon dots into rod-like shapes that can still be re-dispersed into aqueous solution. Schiff bases forming at the surface of carbon dots not only protect their surface states, but also provide sites for tethering to other carbon dots. As a consequence, the large assemblies of CDs can come together to form regular, well ordered structures whilst still maintaining their photoluminescence properties. This opens up enormous possibilities for device manufacture, as these self-assemblies could be grown or grafted onto templates forming regular structures, and find innumerable applications ranging from optoelectronic devices, light harvesting to artificial photosynthesis. Electronic supplementary information (ESI) available: Experimental details and more characterization of carbon dot assemblies. See DOI: 10.1039/c4nr07119k

  15. Direct Assembly of Modified Proteins on Carbon Nanotubes in an Aqueous Solution

    NASA Technical Reports Server (NTRS)

    Kim, Jae-Woo; Lillehei, Peter T.; Park, Cheol; Harrison, Joycelyn S.

    2007-01-01

    Carbon nanotubes (CNTs) have superior mechanical and electrical properties that have opened up many potential applications. However, poor dispersibility and solubility, due to the substantial van der Waals attraction between tubes, have prevented the use of CNTs in practical applications, especially biotechnology applications. Effective dispersion of CNTs into small bundles or individual tubes in solvents is crucial to ensure homogeneous properties and enable practical applications. In addition to dispersion of CNTs into a solvent, the selection of appropriate solvent, which is compatible with a desired matrix, is an important factor to improve the mechanical, thermal, optical, and electrical properties of CNT-based fibers and composites. In particular, dispersion of CNTs into an aqueous system has been a challenge due to the hydrophobic nature of CNTs. Here we show an effective method for dispersion of both single wall CNTs (SWCNTs) and few wall CNTs (FWCNTs) in an aqueous buffer solution. We also show an assembly of cationized Pt-cored ferritins on the well dispersed CNTs in an aqueous buffer solution.

  16. Arsenic removal from aqueous solutions by adsorption onto iron oxide/activated carbon magnetic composite

    PubMed Central

    2014-01-01

    In this work the adsorption features of activated carbon and the magnetic properties of iron oxides were combined in a composite to produce magnetic adsorbent. Batch experiments were conducted to study the adsorption behavior of arsenate onto the synthetic magnetic adsorbent. The effects of initial solution pH, contact time, adsorbent dosage and co-existing anionic component on the adsorption of arsenate were investigated. The results showed that the removal percentage of arsenate could be over 95% in the conditions of adsorbent dosage 5.0 g/L, initial solution pH 3.0-8.0, and contact time 1 h. Under the experimental conditions, phosphate and silicate caused greater decrease in arsenate removal percentage among the anions, and sulfate had almost no effect on the adsorption of arsenate. Kinetics study showed that the overall adsorption rate of arsenate was illustrated by the pseudo-second-order kinetic model. The applicability of the Langmuir and Freundlich models for the arsenate adsorption data was tested. Both the models adequately describe the experimental data. Moreover, the magnetic composite adsorbent could be easily recovered from the medium by an external magnetic field. It can therefore be potentially applied for the treatment of water contaminated by arsenate. PMID:24602339

  17. Prototype wash water renovation system integration with government-furnished wash fixture

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The requirements of a significant quantity of proposed life sciences experiments in Shuttle payloads for available wash water to support cleansing operations has provided the incentive to develop a technique for wash water renovation. A prototype wash water waste renovation system which has the capability to process the waste water and return it to a state adequate for reuse in a typical cleansing fixture designed to support life science experiments was investigated. The resulting technology is to support other developments efforts pertaining to water reclamation by serving as a pretreatment step for subsequent reclamation procedures.

  18. LIQUID NITROGEN WASH PROCESS FOR HELIUM PURIFICATION

    Microsoft Academic Search

    Webb

    1960-01-01

    A preliminary study is made of the possible use of the liquid nitrogen ; wash process for purifying helium for HTGR. The process would remove COâ, ; HâO, and radioactive noble gases from helium and could replace the delay ; and refrigerated traps in the helium purification system being considered for the ; plant, with savings in capital and operating

  19. Recycled Wash Water Crushed Returned Concrete

    E-print Network

    1 Recycled Wash Water Crushed Returned Concrete National Concrete Consortium March 2012 Colin Lobo Initiatives Potable water: 10% reduction by 2020 20% reduction by 2030Recycled content: 200% increase b & Solids Management WWW. NRMCA.ORG Recycling Water Challenge: Recycle Water Specification Clauses Mixing

  20. Washed Out Bridge, Snake Creek Near Whitesburg

    USGS Multimedia Gallery

    Tributary to Snake Creek, near Whitesburg, Georgia, showing a washed out bridge. When bridges such as this one collapse during a flood, it is rarely the pressure of the rushing water against the bridge that causes the bridge to fail. Rather, the rushing water erodes the ground underneath and surroun...

  1. flu preparations Wash your hands, cover

    E-print Network

    Victoria, University of

    SPEED READING flu preparations Wash your hands, cover your sneeze UVic readies for an expected increase in the number of H1N1 (swine flu) cases, providing a wealth of information and direction on how to avoid the flu and what to do if you catch it. Story, page 2 CaMpus raBBits Community help sought

  2. SOIL-WASHING TECHNOLOGY AND PRACTICE

    EPA Science Inventory

    Soil washing in the United States has been studied and evaluated with increasing thoroughness during the last 15 to 20 years. It is now entering a phase of actual use and acceptance as its applicability and economics become clearer. This paper reviews the principles behind soil...

  3. DEMONSTRATION BULLETIN: SOIL WASHING SYSTEM - BIOTROL, INC.

    EPA Science Inventory

    The three component technologies of the BioTrol Soil Washing System (BSWS). Tested in the SITE demonstration were a Soil Washer (SW), and Aqueous Treatment System (ATS), and a Slurry Bio-Reactor (SBR). The Soil Washer operates on the principle that a significant fraction of the...

  4. EVALUATION OF THE BIOGENESIS SOIL WASHING TECHNOLOGY

    EPA Science Inventory

    The BioGenesis Enterprises, Inc. (BioGenesis) soil washing technology was demonstrated as part of the US Environmental Protection Agency's (EPA) Superfund Innovative Technology Evaluation (SITE) program in November 1992. he demonstration was conducted over three days at a petrole...

  5. EVALUATION OF THE BIOGENESIS SOIL WASHING TECHNOLOGY

    EPA Science Inventory

    The BioGenesis Enterprises, Inc. (BioGenesis) soil washing technology was demonstrated as part of the US Environmental Protection Agency's (EPA) Superfund Innovative Technology Evaluation (SITE) program in November 1992. The demonstration was conducted over three days at a petrol...

  6. PROPELLER WASH EFFECTS ON SPRAY DRIFT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For aerial spray application, there is some question if off-target drift (both near and far) is influenced by which boom is spraying and the direction of propeller wash rotation. This information may be useful when switching off one boom close to a field boundary. The effect of alternate boom switch...

  7. When and How to Wash Your Hands

    MedlinePLUS

    ... should you do if you don’t have soap and clean, running water? Washing hands with soap and water is the best way to reduce ... of microbes on them in most situations. If soap and water are not available, use an alcohol- ...

  8. FIELD STUDIES OF IN SITU SOIL WASHING

    EPA Science Inventory

    The EPA and US Air Force conducted a research test program to demonstrate the removal of hydrocarbons and chlorinated hydrocarbons from a sandy soil by in situ soil washing using surfactants. Contaminated soil from the fire training area of Volk Air National Guard Base, WI, was f...

  9. Wash your hands. water and soap.

    E-print Network

    not freeze Powdered formula that is mixed with water 1 day after the formula is mixed. Store the can of powdered formula in a cool dry place. Do not freeze Concentrated formula that is mixed with water StoreSTEP 1 Wash your hands. · Use warm water and soap. · Scrub hands and fingernails for at least 20

  10. What Happens at a Car Wash?

    ERIC Educational Resources Information Center

    Gallick, Barbara; Lee, Lisa

    2010-01-01

    A class of 3- to 5-year-old children in a child care center in the midwestern United States chose to study a car wash as a group project. This article discusses how the project evolved, describes the three phases of the project, and provides the teachers' reflections on the project. Photos taken during the project and children's sketches are…

  11. Linking process and product in terrestrial carbonates using a solution thermodynamic approach

    NASA Astrophysics Data System (ADS)

    Rogerson, M.; Pedley, H. M.; Kelham, A.

    2013-09-01

    Determining the processes which generate terrestrial carbonate deposits (tufas, travertines and associated chemical sediments) is a long-standing problem. Deposition of mineral products from solution reflects a complex combination of biological, equilibrium and kinetic processes, and the differences in products these processes produce are yet to be clearly demarked. Building on the groundbreaking work of previous authors, we propose that the underlying control on the processes leading to the deposition of these products can be most parsimoniously understood from the thermodynamic properties of their source solutions. Here, we report initial observations of the differences in product generated from spring and lake systems spanning a range of temperature : supersaturation space. We find that at high supersaturation, biological influences are masked by high rates of spontaneous nucleation and sedimentary products from these settings infrequently exhibit classic "biomediated" fabrics such as clotted micrite. Likewise, at high temperature exclusion of vascular plants and complex/diverse biofilms significantly inhibits the magnitude of biomediated precipitation, again impeding the likelihood of encountering the "bio-type" fabrics. Conversely, despite the clear division in product between extensive tufa facies associations and discontinuous deposits such as oncoid beds, no clear division can be identified between these systems in temperature : supersaturation space. We reiterate the conclusion of previous authors, which demonstrate that this division cannot be made on the basis of physico-chemical characteristics of the solution alone. We further provide a new case study of this division from two adjacent systems in the UK, where continuous tufa-like deposition is happening at a site with lower supersaturation than other sites exhibiting only discontinuous (oncoidal) deposition. However, a strong microbiological division is demonstrated between these sites on the basis of suspended bacterial cell distribution, which reach a prominent maximum where tufa-like deposits are forming. We conclude that at high supersaturation, the thermodynamic properties of solutions provide a highly satisfactory means of linking process and product, raising the opportunity of identifying water characteristics from sedimentological/petrological characteristics of ancient deposits. At low supersaturation, we recommend that future research focuses on geomicrobiological processes rather than the more traditional, inorganic solution chemistry approach dominant in the past.

  12. Core wash cytology of breast lesions by ultrasonographically guided core needle biopsy.

    PubMed

    Uematsu, Takayoshi; Kasami, Masako

    2008-05-01

    Previous studies demonstrated that core wash cytology by stereotactic needle biopsy was useful for the immediate diagnosis of breast lesions. The purpose of this study was to assess the accuracy of core wash cytology of breast lesions by ultrasonographically (US) guided core needle biopsy (CNB). US-guided 18-gauge CNB was performed in a series of 458 cases. Each CNB sample was washed in saline solution. Core wash cytology of the washed core material was performed on material obtained by saline solution lavage of the fragments using a cytocentrifuge. The cytological diagnoses were divided into five categories: benign, atypical/indeterminate, suspicious/probably malignant, malignant, and unsatisfactory, which then were compared with the CNB results. The cytological diagnoses of the 458 cases were as follows: 106 lesions (23.1%) were benign, 28 lesions (6.1%) were atypical/indeterminate, 42 lesions (9.2%) were suspicious/probably malignant, 88 lesions (19.2%) were malignant, and 194 lesions (42.4%) were unsatisfactory. The core wash cytology had a sensitivity of 89% (141 of 158), and a specificity of 72% (76 of 106). The CNB showed 143 of 194 unsatisfactory samples (74%) to be benign, three to be high-risk, and 48 (25%) to be malignant. Unsatisfactory samples were obtained from significantly more benign than malignant lesions. In conclusion, the high rate of insufficient samples for core wash cytology of breast lesions by US-guided CNB makes its use impractical in this setting. This technique is not useful for immediate diagnosis of breast lesions by US-guided CNB. PMID:17616804

  13. A Novel Glycinate-based Body Wash

    PubMed Central

    Regan, Jamie; Ananthapadmanabhan, K.P.

    2013-01-01

    Objective: To assess the properties of a novel body wash containing the mild surfactant glycinate. Design: Biochemical and clinical assays. Setting: Research laboratories and clinical sites in the United States and Canada. Participants: Women 18 to 65 years of age (cleansing efficacy); male and female subjects 26 to 63 years of age with mild or moderate dryness and erythema (leg-controlled application test); subjects 5 to 65 years of age with mild-to-moderate eczema (eczema compatibility); and women 18 to 64 years of age (home use). Measurements: Assessments across studies included colorimetric dye exclusion to assess skin damage potential (corneosurfametry), efficacy of cosmetic product removal from skin, change from baseline in visual dryness, change from baseline in Eczema Area and Severity Index, and self-perceived eczema attributes and self-reported product preference. Results: The glycinate-based cleanser demonstrated mildness to skin components when evaluated in a corneosurfametry assay. Short-term use under exaggerated wash conditions in subjects with dryness scores <3 and erythema scores <2 (both on a 0-6 scale) indicated an initial reduction in visual dryness. In subjects with eczema, normal use resulted in significant improvements (p<0.05) at Week 4 compared with baseline in skin dryness (change from baseline = ?0.73), rash (?0.56), itch (?0.927), tightness (?0.585), and all eczema (?0.756). The glycinate-based body wash removed 56 percent of a long-lasting cosmetic foundation from skin compared with less than 30 percent removed by two competitive products tested. The glycinate-based body wash was preferred over a competitive mild cleansing product overall. Conclusion: The patented glycinate-containing body wash demonstrated better product mildness and patient-preferred attributes and clinical benefits. PMID:23882306

  14. Chemical Changes at the Interface Between Low Carbon Steel and an Al-Si Alloy During Solution Heat Treatment

    E-print Network

    Paris-Sud XI, Université de

    , joining, steel 1. Introduction Aluminium-silicon alloy castings are nowadays widely used by the automotive of aluminium-silicon alloy castings consists in reinforcing them locally with steel or cast iron insertsChemical Changes at the Interface Between Low Carbon Steel and an Al-Si Alloy During Solution Heat

  15. Pyridine as a probe molecule for surface enhanced Raman spectroscopy of the silver-modified glassy carbon\\/solution interface

    Microsoft Academic Search

    Peter Mayer; Rudolf Holze

    2003-01-01

    Pyridine is employed as a probe molecule to study with surface enhanced Raman spectroscopy the interface between an aqueous electrolyte solution and an electrochemically activated glassy carbon surface modified with electrodeposited silver. Results demonstrate the feasibility of this approach. The surface of the silver deposits shows surface enhanced Raman scattering without further activation. Band positions are compared with those obtained

  16. Adsorption of Pb(II) From Aqueous Solutions by Chemically Modified Zeolite Supported Carbon Nanotubes: Equilibrium, Kinetic and Thermodynamic Studies

    Microsoft Academic Search

    D. K. Venkata Ramana; D. Harikishore Kumar Reddy; B. Naresh Kumar; K. Seshaiah; G. Purna Chandra Rao; Chungsying Lu

    2012-01-01

    Zeolite supported carbon nanotubes (ZCNTs) were synthesized by the catalytic chemical vapor deposition (CCVD) method. The physical and chemical properties such as surface area, pore diameter, surface functional groups and total acidic and basic sites of the ZCNTs were studied. They were employed as adsorbent to study the adsorption characteristics of Pb(II) in aqueous solution. The adsorption of Pb(II), increase

  17. Removal of Metanil Yellow from its Aqueous Solution by Fly Ash and Activated Carbon Produced from Different Sources

    Microsoft Academic Search

    Amiya Kumar Santra; Tapan Kumar Pal; Siddhartha Datta

    2008-01-01

    The present study has been undertaken to observe the relative efficiency of removal of metanil yellow from its aqueous solution by using different adsorbents like fly ash and activated carbon produced from different sources i.e. coconut shell, mehagani saw dust, and rice husk. It has also been observed that the rate of adsorption is highly dependent on contact time, adsorbent

  18. The influence of surface chemistry on activated carbon adsorption of 2-methylisoborneol from aqueous solution

    Microsoft Academic Search

    Robert Considine; Renaud Denoyel; Phillip Pendleton; Russell Schumann; Shiaw-Hui Wong

    2001-01-01

    An activated carbon with a relatively high oxygen content was heated at various temperatures in an argon atmosphere to produce a series of carbons with decreasing oxygen content. A second activated carbon with a relatively low oxygen content was treated with an ozone–oxygen mixture to produce a series of carbons with increasing oxygen content. In both cases, the pore size

  19. Use of rice husk-based porous carbon for adsorption of Rhodamine B from aqueous solutions

    Microsoft Academic Search

    Yupeng Guo; Jingzhe Zhao; Hui Zhang; Shaofeng Yang; Jurui Qi; Zichen Wang; Hongding Xu

    2005-01-01

    This paper complements the previous one (adsorption of Malachite Green). Adsorption of Rhodamine B (RB) by rice husk-based porous carbons (RHCs) and commercial carbons from aqueous medium have been studied. Three samples of carbons prepared by NaOH activation, three samples prepared by KOH activation and two samples of commercial carbons have been used. The adsorption isotherms have been determined after

  20. The Solar Nebula on Fire: A Solution to the Carbon Deficit in the Inner Solar System

    Microsoft Academic Search

    Jeong-Eun Lee; Edwin A. Bergin; Hideko Nomura

    2010-01-01

    Despite a surface dominated by carbon-based life, the bulk composition of the Earth is dramatically carbon poor when compared to the material available at formation. Bulk carbon deficiency extends into the asteroid belt representing a fossil record of the conditions under which planets are born. The initial steps of planet formation involve the growth of primitive sub-micron silicate and carbon

  1. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    NASA Astrophysics Data System (ADS)

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-01

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  2. Calcium-magnesium carbonate solid solutions from Holocene conglomerate cements and travertines in the Coast Range of California

    USGS Publications Warehouse

    Barnes, I.; O'Neil, J.R.

    1971-01-01

    Two calcium-magnesium carbonate solid solutions form Holocene travertines and conglomerate cements in fresh water stream channels of the Coast Range of California. Calcite does not yield the {015} diffraction maximum. The {006} diffraction maximum is lacking over most of the range of composition of calcite. Calcite has compositions from CaCO3 to Ca0.5Mg0.5CO3. Dolomite yields both the {006} and {015} diffraction maxima over its entire composition range, Ca0.6Mg0.4CO3 to Ca0.5Mg0.5CO3. The Ca-Mg carbonates form in isotopic equilibrium and thermodynamic disequilibrium from dispersion of Ca2+-rich water into CO32--rich water within the alluvium. The stable isotope data suggest that all the Mg-rich carbonates are primary precipitates and not a result of Mg-substitution in precursor CaCO3. There is a correlation between ??C13 and Mg content of the carbonates which predicts a 5%. fractionation of C13 between dolomite and calcite at sedimentary temperatures. C14 is incorporated in Ca-Mg carbonates forming from C13-poor meteoric waters and C13-rich waters from Cretaceous sediments. C14 ages of the Ca-Mg carbonates are apparent, and cannot be corrected to absolute values. Solution rates of calcite decrease with increasing MgCO3 content; dolomite dissolves slower than any calcite. ?? 1971.

  3. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    SciTech Connect

    Solehudin, Agus, E-mail: asolehudin@upi.edu [Department of Mechanical Engineering Education, Indonesia University of Education (UPI), Bandung, West Java (Indonesia); Nurdin, Isdiriayani [Department of Chemical Engineering, Bandung Institute of Technology, Bandung, West Java (Indonesia)

    2014-03-24

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  4. Polymorph selection and nanocrystallite rearrangement of calcium carbonate in carboxymethyl chitosan aqueous solution: Thermodynamic and kinetic analysis

    SciTech Connect

    Zhao, Donghui [Key Lab For Special Functional Materials Ministry of Education, Henan University, Kaifeng 475004 (China) [Key Lab For Special Functional Materials Ministry of Education, Henan University, Kaifeng 475004 (China); Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi, Changning, Shanghai 200050 (China); Zhu, Yingchun, E-mail: yzhu@mail.sic.ac.cn [Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi, Changning, Shanghai 200050 (China)] [Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi, Changning, Shanghai 200050 (China); Li, Fang; Ruan, Qichao [Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi, Changning, Shanghai 200050 (China)] [Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi, Changning, Shanghai 200050 (China); Zhang, Shengmao [Key Lab For Special Functional Materials Ministry of Education, Henan University, Kaifeng 475004 (China)] [Key Lab For Special Functional Materials Ministry of Education, Henan University, Kaifeng 475004 (China); Zhang, Linlin; Xu, Fangfang [Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi, Changning, Shanghai 200050 (China)] [Key Lab of Inorganic Coating Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi, Changning, Shanghai 200050 (China)

    2010-01-15

    In this article, the polymorph selection of calcium carbonate has been successfully achieved in water-soluble carboxymethyl chitosan aqueous solution at different temperatures (25-95 {sup o}C). Vaterite is formed in carboxymethyl chitosan solution 25 {sup o}C accompanied with trace of calcite, whereas pure aragonite is obtained at 95 {sup o}C. Scanning electron microscopy and transmission electron microscopy analyses show that the products are formed from the recrystallization of nanometer crystallites. Thermodynamic and kinetic analyses reveal that the polymorph of calcium carbonate is controlled and selected by kinetics in various temperatures. As a heterogeneous nucleator and stabilizing agent, carboxymethyl chitosan changes the nucleation and growth of calcium carbonate from thermodynamic into kinetic control. Under kinetic limitation, the reaction rate of aragonite increases along with the elevating of temperature and surpasses the rate of vaterite above 327 K.

  5. Energetic changes in the surface of activated carbons and relationship with Ni(II) adsorption from aqueous solution

    NASA Astrophysics Data System (ADS)

    Rodríguez-Estupiñan, Paola; Giraldo, Liliana; Moreno-Piraján, Juan Carlos

    2013-12-01

    This study investigated Ni(II) ion adsorption from aqueous solution on activated carbons obtained by chemically modifying the surface with the oxidizing agents nitric acid and hydrogen peroxide (CAGoxP and CAGoxN, respectively). The activated carbons were characterized by total acidity and basicity, pH at the point of charge zero determination and IR spectroscopy. Textural parameters such as the BET area and pore volumes were evaluated by gas adsorption. The BET area of the materials was between 816 and 876 m2 g-1. Additionally, the immersion enthalpies of the activated carbons in water and benzene were determined. The experimental results on adsorption in solution were adjusted to the Langmuir and Freundlich models, obtaining values for the monolayer capacity between 29.68 and 50.97 mg g-1, which indicates that the adsorption capacity depends largely on solid surface chemistry.

  6. On the effects of solution and reaction parameters for the aerosol-assisted CVD growth of long carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Barreiro, A.; Selbmann, D.; Pichler, T.; Biedermann, K.; Gemming, T.; Rümmeli, M. H.; Schwalke, U.; Büchner, B.

    2006-03-01

    High-purity vertically aligned films of multi-wall carbon nanotubes have been synthesized via an aerosol-assisted CVD method using a solution of ferrocene in m-xylene. This method provides good control over the nanotube diameter by varying a number of solution or reaction parameters such as the ferrocene concentration in the solution, the hydrogen content in the gas flow or the ultrasonication frequency producing the aerosol droplets. We are the first to report a nanotube diameter reduction from smaller aerosol droplets by increasing the ultrasonication frequency.

  7. Activated carbon enhanced ozonation of oxalate attributed to HO oxidation in bulk solution and surface oxidation: effect of activated carbon dosage and pH.

    PubMed

    Xing, Linlin; Xie, Yongbing; Minakata, Daisuke; Cao, Hongbin; Xiao, Jiadong; Zhang, Yi; Crittenden, John C

    2014-10-01

    Ozonation of oxalate in aqueous phase was performed with a commercial activated carbon (AC) in this work. The effect of AC dosage and solution pH on the contribution of hydroxyl radicals (HO) in bulk solution and oxidation on the AC surface to the removal of oxalate was studied. We found that the removal of oxalate was reduced by tert-butyl alcohol (tBA) with low dosages of AC, while it was hardly affected by tBA when the AC dosage was greater than 0.3g/L. tBA also inhibited ozone decomposition when the AC dosage was no more than 0.05g/L, but it did not work when the AC dosage was no less than 0.1g/L. These observations indicate that HO in bulk solution and oxidation on the AC surface both contribute to the removal of oxalate. HO oxidation in bulk solution is significant when the dosage of AC is low, whereas surface oxidation is dominant when the dosage of AC is high. The oxalate removal decreased with increasing pH of the solution with an AC dosage of 0.5g/L. The degradation of oxalate occurs mainly through surface oxidation in acid and neutral solution, but through HO oxidation in basic bulk solution. A mechanism involving both HO oxidation in bulk solution and surface oxidation was proposed for AC enhanced ozonation of oxalate. PMID:25288554

  8. Comparison of the Laboratory Standard Washing Using CIPAC Washing Agent and the Domestic Washing on Three Recommended Types of Long-Lasting Insecticidal Mosquito Nets

    PubMed Central

    Ouattara, Jean Pierre Nabléni; Louwagie, Johanna; Pigeon, Olivier; Spanoghe, Pieter

    2013-01-01

    Background One of the best ways to prevent malaria is the use of insecticide-treated bed nets. Manufacturers pursue easier, safer and more efficient nets. Hence, many studies on the efficacy and wash resistance using World Health Organization standards have been reported. The commonly used detergent is “Savon de Marseille”, because it closely resembles actually used soaps. At the 54th Collaborative International Pesticides Analytical Council (CIPAC) Technical Meeting in 2010, it was suggested to replace it by a standardized “CIPAC washing agent”. The aim of this study was to investigate the difference between a laboratory hand washing simulation using the CIPAC washing agent (method-1) and a domestic washing (method-2) on different bed nets, as well as the effect of the drying process on the release of active ingredient. Methods Interceptor®, Permanet®2.0 and Netprotect® nets were used in three treatments, each repeated 20 times. The first treatment included method-1 washing and indoor drying. The second treatment included method-2 washing and indoor drying. The third treatment used method-2 washing and UV-drying. The residual insecticide contents were determined using gas chromatography. Results The washing procedure and the number of washes have a significant effect on the release of active ingredient. Statistically, the two washing methods have the same effect on removing the active ingredient from the Interceptor® and Permanet®2.0 net, but a significantly different influence on the Netprotect® nets. The drying process has no significant effect on the insecticide. Conclusion Both washing procedures affected the amount of insecticide remaining on nets independently of the impregnation technology. The active ingredient decreases with the number of washing cycles following an exponential or logarithmic model for coated nets. The laboratory hand washing simulation had more impact on the decrease of active ingredient content of the Netprotect® nets. All net types seemed to be effectively protected against UV-light. PMID:24130671

  9. Density of hydroxyl radicals generated in an aqueous solution by irradiating carbon-ion beam.

    PubMed

    Matsumoto, Ken-Ichiro; Ueno, Megumi; Nakanishi, Ikuo; Anzai, Kazunori

    2015-03-01

    The density of hydroxyl radicals (·OH) produced in aqueous samples by exposure to X-ray or carbon-ion beams was investigated. The generation of ·OH was detected by the electron paramagnetic resonance (EPR) spin-trapping technique using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as the spin-trapping agent. When the concentration of DMPO is in excess of the generated ·OH, the production of DMPO-OH (spin-trapped ·OH) should be saturated. Reaction mixtures containing several concentrations (0.5-1685?mM) of DMPO were then irradiated by a 32?Gy 290?MeV carbon-ion beam (C290-beam) or X-ray. C290-beam irradiation was performed at the Heavy-Ion Medical Accelerator in Chiba (HIMAC, National Institute of Radiological Sciences, Chiba, Japan), applying different linear energy transfers (LET) (20-169?keV/µm). The amount of DMPO-OH in the irradiated samples was detected by EPR spectroscopy. The generation of DMPO-OH increased with the concentration of initial DMPO, displayed a shoulder around 3.3?mM DMPO, and reached a plateau. This plateau suggests that the generated ·OH were completely trapped. Another linear increase in DMPO-OH measured in solutions with higher DMPO concentrations suggested very dense ·OH generation (>1.7?M). Generation of ·OH is expected to be localized on the track of the radiation beam, because the maximum concentration of measured DMPO-OH was 40?µM. These results suggested that both sparse (?3.3?mM) and dense (>1.7?M) ·OH generation occurred in the irradiated samples. The percentage of dense ·OH generation increased with increasing LET. Different types of dense ·OH generation may be expected for X-ray and C290-beams. PMID:25757490

  10. Role of lauric acid-potassium hydroxide concentration on bacterial contamination of spray washed broiler carcasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of experiments were conducted to examine reductions in bacterial contamination of broiler carcasses washed in a spray cabinet with various concentrations of lauric acid (LA)-potassium hydroxide (KOH) solutions. Fifty eviscerated carcasses and 5 ceca were obtained from the processing line of...

  11. Effect of washing broiler carcasses in potassium hydroxide and lauric acid on native bacterial flora

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to examine the bactericidal effect of potassium hydroxide (KOH) and lauric acid (LA) on the native bacterial flora of broiler carcasses. Carcasses were placed in solutions of 1.0% KOH and 2.0 % LA or in distilled water (control) and washed by shaking for 1 min on a mechani...

  12. Influence of washing time on residual contamination of carcasses sprayed with lauric acid-potassium hydroxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of experiments were conducted to examine reductions in bacterial contamination of broiler carcasses washed for various times in a spray cabinet with a 2% lauric acid (LA)-1% potassium hydroxide (KOH) solution (w/v). Forty eviscerated carcasses and 5 ceca were obtained from the processing li...

  13. Influence of washing time on residual contamination of carcasses sprayed with lauric acid-potassium hydroxide.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of experiments were conducted to examine reductions in bacterial contamination of broiler carcasses washed for various times in a spray cabinet with a 2% lauric acid (LA)-1% potassium hydroxide (KOH) (w/v) solution. Forty eviscerated carcasses and 5 ceca were obtained from the processing l...

  14. Activity and stability of immobilized carbonic anhydrase for promoting CO2 absorption into a carbonate solution for post-combustion CO2 capture.

    PubMed

    Zhang, Shihan; Zhang, Zhaohui; Lu, Yongqi; Rostam-Abadi, Massoud; Jones, Andrew

    2011-11-01

    An Integrated Vacuum Carbonate Absorption Process (IVCAP) currently under development could significantly reduce the energy consumed when capturing CO2 from the flue gases of coal-fired power plants. The biocatalyst carbonic anhydrase (CA) has been found to effectively promote the absorption of CO2 into the potassium carbonate solution that would be used in the IVCAP. Two CA enzymes were immobilized onto three selected support materials having different pore structures. The thermal stability of the immobilized CA enzymes was significantly greater than their free counterparts. For example, the immobilized enzymes retained at least 60% of their initial activities after 90 days at 50 °C compared to about 30% for their free counterparts under the same conditions. The immobilized CA also had significantly improved resistance to concentrations of sulfate (0.4 M), nitrate (0.05 M) and chloride (0.3 M) typically found in flue gas scrubbing liquids than their free counterparts. PMID:21974883

  15. Activity and stability of immobilized carbonic anhydrase for promoting CO2 absorption into a carbonate solution for post-combustion CO2 capture

    USGS Publications Warehouse

    Zhang, S.; Zhang, Z.; Lu, Y.; Rostam-Abadi, M.; Jones, A.

    2011-01-01

    An Integrated Vacuum Carbonate Absorption Process (IVCAP) currently under development could significantly reduce the energy consumed when capturing CO2 from the flue gases of coal-fired power plants. The biocatalyst carbonic anhydrase (CA) has been found to effectively promote the absorption of CO2 into the potassium carbonate solution that would be used in the IVCAP. Two CA enzymes were immobilized onto three selected support materials having different pore structures. The thermal stability of the immobilized CA enzymes was significantly greater than their free counterparts. For example, the immobilized enzymes retained at least 60% of their initial activities after 90days at 50??C compared to about 30% for their free counterparts under the same conditions. The immobilized CA also had significantly improved resistance to concentrations of sulfate (0.4M), nitrate (0.05M) and chloride (0.3M) typically found in flue gas scrubbing liquids than their free counterparts. ?? 2011 Elsevier Ltd.

  16. Breadboard wash water renovation system. [using ferric chloride and ion exchange resins to remove soap and dissolved salts

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A total wash water renovation system concept was developed for removing objectionable materials from spacecraft wash water in order to make the water reusable. The breadboard model system described provides for pretreatment with ferric chloride to remove soap by chemical precipitation, carbon adsorption to remove trace dissolved organics, and ion exchange for removal of dissolved salts. The entire system was put into continuous operation and carefully monitored to assess overall efficiency and equipment maintenance problems that could be expected in actual use. In addition, the capacity of the carbon adsorbers and the ion-exchange resin was calculated and taken into consideration in the final evaluation of the system adequacy. The product water produced was well within the Tentative Wash Water Standards with regard to total organic carbon, conductivity, urea content, sodium chloride content, color, odor, and clarity.

  17. Metallocoenzyme-mediated reductive transformation of carbon tetrachloride in titanium (III) citrate aqueous solution

    SciTech Connect

    Chiu, P.C.; Reinhard, M. [Stanford Univ., CA (United States)

    1995-03-01

    Transformation pathways for carbon tetrachloride (CCl{sub 4}) catalyzed by hematin or vitamin B{sub 12} in aqueous titanium(III) citrate solution are proposed. The reaction of CCl{sub 4} with B{sub 12} was zero order in CCl{sub 4} and first order in B{sub 12}, and the rate constant was measured from pH 7.3 to pH 10.3. The proposed rate-limiting step is the reduction of the stable trichloromethylcobalamin (CCl{sub 3}-Cbl) intermediate by titanium(III) citrate at alkaline pH and the sterically induced CCl{sub 3}-Cbl decomposition at neutral pH. The reaction kinetics can be described by a modified Michaelis-Menten model in the saturated regime. With hematin, only the pseudo-first-order rate constant was determined due to the significant deactivation of the coenzyme. The turnover number of hematin (molecules of CCl{sub 4} transformed/molecule of hematin deactivated) was 27 at pH 8.0 and 42 at pH 9.9. Vitamin B{sub 12} was a more stable and more effective catalyst (on a molar basis) than hematin with respect to CCl{sub 4}. Chloroform (CHCl{sub 3}) was the primary product in titanium(III) citrate solution, and the yield was a function of pH, Ti(III) concentration, and organic content regardless of whether a coenzyme was present or which coenzyme was used. Although B{sub 12} and hematin can both enhance the CCl{sub 4} transformation rate, they have little effect on the CHCl{sub 3} yield. Titanium(III) citrate, on the other hand, controls not only the transformation rate but also CHCl{sub 3} formation. 77 refs., 10 figs.

  18. Electrocatalytic reduction of oxygen on bimetallic copper–gold nanoparticles–multiwalled carbon nanotube modified glassy carbon electrode in alkaline solution

    Microsoft Academic Search

    Ça?r? Ceylan Bak?r; Nihat ?ahin; Ramazan Polat; Zekerya Dursun

    2011-01-01

    Multiwalled carbon nanotubes (MWCNTs) were functionalized with acid treatment and thereafter gold–copper nanoparticles were electrodeposited on the MWCNTs by applying several repetitive scans, thus forming a Cu–Au–MWCNT\\/GCE interface. The electrochemical reduction of oxygen was studied on this modified electrode in 0.1M NaOH solution. The electrocatalytic activity on the Cu–Au–MWCNT\\/GCE showed a tendency towards the O2 reduction. The peak potential of

  19. Performance of high-recovery recycling reverse osmosis with wash water

    NASA Technical Reports Server (NTRS)

    Herrmann, Cal C.

    1993-01-01

    Inclusion of a recycling loop for partially-desalted water from second-stage reverse-osmosis permeate has been shown useful for achieving high-recovery at moderate applied pressures. This approach has now been applied to simulated wash waters, to obtain data on retention by the membranes of solutes in a mixture comparable to anticipated spacecraft hygiene wastewaters, and to generate an estimate of the maximum concentration that can be expected without causing membrane fouling. A first experiment set provides selectivity information from a single membrane and an Igepon detergent, as a function of final concentration. A reject concentration of 3.1% Total Organic Carbon has been reached, at a pressure of 1.4 Mega Pascals, without membrane fouling. Further experiments have generated selectivity values for the recycle configuration from two washwater simulations, as a function of applied pump pressure. Reverse osmosis removal has also been tested for washwater containing detergent formulated for plant growth compatibility (containing nitrogen, phosphorous and potassium functional groups.)

  20. 4. AERIAL VIEW OF GENE WASH RESERVOIR AND GENE CAMP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. AERIAL VIEW OF GENE WASH RESERVOIR AND GENE CAMP LOOKING SOUTHWEST. DAM AND SPILLWAY VISIBLE IN BOTTOM OF PHOTO. - Gene Wash Reservoir & Dam, 2 miles west of Parker Dam, Parker Dam, San Bernardino County, CA

  1. 30 CFR 206.260 - Allocation of washed coal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Allocation of washed coal. 206.260 Section 206.260 Mineral Resources...REVENUE MANAGEMENT PRODUCT VALUATION Federal Coal § 206.260 Allocation of washed coal. (a) When coal is subjected to...

  2. 30 CFR 206.459 - Allocation of washed coal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Allocation of washed coal. 206.459 Section 206.459 Mineral Resources...REVENUE MANAGEMENT PRODUCT VALUATION Indian Coal § 206.459 Allocation of washed coal. (a) When coal is subjected to...

  3. BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTHWEST. - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

  4. 33 CFR 162.230 - Columbia River, Wash.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 2010-07-01 false Columbia River, Wash. 162.230 Section 162.230 Navigation and Navigable...WATERWAYS NAVIGATION REGULATIONS § 162.230 Columbia River, Wash. (a) Grand Coulee Dam discharge channel; restricted...

  5. 6. GENE WASH DAM, LOOKING NORTHWEST. SURVEY REFLECTOR IN FOREGROUND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. GENE WASH DAM, LOOKING NORTHWEST. SURVEY REFLECTOR IN FOREGROUND FOR MONITORING MOVEMENT OF DAM AND EARTH. - Gene Wash Reservoir & Dam, 2 miles west of Parker Dam, Parker Dam, San Bernardino County, CA

  6. Detection and determination of solute carbon in grain interior to correlate with the overall carbon content and grain size in ultra-low-carbon steel.

    PubMed

    Dong, Jiling; He, Yinsheng; Lee, Chan-Gyu; Lee, Byungho; Yoon, Jeongbong; Shin, Keesam

    2013-08-01

    In this study, every effort was exerted to determine and accumulate data to correlate microstructural and compositional elements in ultra-low-carbon (ULC) steels to variation of carbon content (12-44 ppm), manganese (0.18-0.36%), and sulfur (0.0066-0.001%). Quantitative analysis of the ULC steel using optical microscope, scanning electron microscope, transmission electron microscope, and three-dimensional atom probe revealed the decrease of grain size and dislocation density with the increase of carbon contents and/or increase of the final delivery temperature. For a given carbon content, the grain interior carbon concentration increases as the grain size increases. PMID:23920177

  7. Carbon Solution in Core-Forming Magma Ocean Conditions: Implications for the Origin and Distribution of Terrestrial Carbon

    NASA Astrophysics Data System (ADS)

    Dasgupta, R.; Chi, H.; Walker, D.; Shimizu, N.; Buono, A. S.

    2012-12-01

    The origin of bulk silicate Earth carbon inventory is poorly known and the fate of the element during the early Earth differentiation and core formation is a missing link in the evolution of the terrestrial carbon cycle. Here we present high pressure-temperature experiments that simulate metal-silicate equilibria in a shallow magma ocean. Experiments were performed at 1-5 GPa, 1600-2100 °C on mixtures of synthetic or natural silicates (tholeiitic basalt/ alkali basalt/ komatiite/ fertile peridotite) and Fe-Ni-C±Co±S contained in graphite or MgO capsules. All the experiments produced immiscible Fe-rich metallic and silicate melts at oxygen fugacity (fO2) between ~IW-1.5 and IW-1.9. Carbon and hydrogen concentrations of basaltic glasses and non-glassy quenched silicate melts were determined using secondary ionization mass spectrometry (SIMS) and speciation of dissolved C-O-H volatiles in silicate glasses was constrained using Raman spectroscopy. Carbon contents of metallic melts were determined using both electron microprobe and SIMS. Our experiments indicate that at core-forming, reduced conditions, carbon in mafic-ultramafic magmas dissolves primarily as various hydrogenated species and the total carbon storage capacity, although is significantly higher than solubility of CO2 under similar conditions, remains low (<500 ppm). The total carbon content in our reduced melts at graphite saturation increases with increasing melt depolymerization (NBO/T), consistent with recent spectroscopic studies [1], and modestly with increasing hydration. Carbon behaves as a metal loving element during core-mantle separation and metal/silicate carbon partition coefficient, DC varies between ~3500 and ?150 and increases with increasing pressure and decreases with increasing temperature and melt NBO/T. Extrapolation of our data to the plausible conditions of core-mantle equilibration suggest that if only a trace amount of carbon (~730 ppm C; [2]) was available during early Earth differentiation, most of it was partitioned to the core (with 0.20-0.25 wt.% C) and no more than ~10-30% of the present-day mantle carbon budget (50-200 ppm CO2) could be derived from a magma ocean residual to core formation. With equilibrium core formation removing most of the carbon initially retained in the terrestrial magma ocean, explanation of the modern bulk silicate Earth carbon inventory requires a later replenishment mechanism. Partial entrapment of metal melt in solid silicate matrix, carbon ingassing by magma ocean-atmosphere interaction, and carbon outgassing from the core aided by reaction of core metal and deeply subducted water are some of the viable mechanisms. [1] Mysen et al. (2009), GCA 73, 1696-1710. [2] McDonough (2003), The Mantle and Core, Treatise of Geochemistry, 547-568.

  8. Fouling of membranes during microfiltration of surimi wash water: Roles of pore blocking and surface cake formation

    Microsoft Academic Search

    Lihan Huang; Michael T Morrissey

    1998-01-01

    Studies were conducted to investigate the development of membrane fouling in the microfiltration of protein solutions such as surimi wash water, containing both soluble and suspended proteinaceous solids. A laboratory scale plate-and-frame crossflow membrane filtration unit was fabricated and installed. Continuous filtration was performed to recover the suspended myofibrillar proteins from the wash water at refrigerated temperatures (12–15°C) using polysulfone

  9. A new technique for bladder washing.

    PubMed

    Miller, D C; Fitkin, D L; Kropp, K A; Selman, S H

    1992-01-01

    We describe a simple adaptation of the Water Pik (Teledyne Water Pik, Fort Collins, Colorado) irrigating device which allows vigorous, direct-vision agitation of the bladder wall. Three groups of mongrel dogs were subjected to cystoscopy and either syringe barbotage, half-speed Water Pik irrigation, or full-speed Water Pik irrigation of the bladder wall. Transitional cell counts were then done on centrifuged aliquots of each bladder wash specimen. The average number of transitional cells per high-power field were similar between the control group and the syringe barbotage group (2.5 and 1.5 respectively). However, both the half-speed and the full-speed Water Pik groups demonstrated statistically higher cell counts (5.7 and 13.7) when compared to both the controls and syringe barbotage groups. We conclude that Water Pik irrigation is an effective method to increase cell yield in bladder wash specimens. PMID:1729530

  10. Continuous concentration and constant volume washing of tetraphenylborate slurries

    SciTech Connect

    Siler, J.L.

    1999-12-08

    SRTC has completed filtration testing of tetraphenylborate (TPB) slurries with and without sludge. These tests were slightly different from previous SRS tests in that they used continuous mode concentration and constant volume washing evolutions. The extent of TPB recovery during washing was measured. The resulting washed precipitate slurry, with sludge, was stored at ambient temperature and under a nitrogen-inerted atmosphere to study TPB stability. Samples of both unwashed and washed slurries were submitted for rheology measurements.

  11. Low-cost, solution processable carbon nanotube supercapacitors and their characterization

    NASA Astrophysics Data System (ADS)

    Lehtimäki, Suvi; Tuukkanen, Sampo; Pörhönen, Juho; Moilanen, Pasi; Virtanen, Jorma; Honkanen, Mari; Lupo, Donald

    2014-06-01

    We report ecological and low-cost carbon nanotube (CNT) supercapacitors fabricated using a simple, scalable solution processing method, where the use of a highly porous and electrically conductive active material eliminates the need for a current collector. Electrodes were fabricated on a poly(ethylene terephthalate) substrate from a printable multi-wall CNT ink, where the CNTs are solubilized in water using xylan as a dispersion agent. The dispersion method facilitates a very high concentration of CNTs in the ink. Supercapacitors were assembled using a paper separator and an aqueous NaCl electrolyte and the devices were characterized with a galvanostatic discharge method defined by an industrial standard. The capacitance of the 2 cm^2 devices was 6 mF/cm^2 (2.3 F/g) and equivalent series resistance 80 ? . Low-cost supercapacitors fabricated from safe and environmentally friendly materials have potential applications as energy storage devices in ubiquitous and autonomous intelligence as well as in disposable low-end products.

  12. Degradation of carbon tetrachloride in aqueous solution in the thermally activated persulfate system.

    PubMed

    Xu, Minhui; Gu, Xiaogang; Lu, Shuguang; Qiu, Zhaofu; Sui, Qian; Miao, Zhouwei; Zang, Xueke; Wu, Xiaoliang

    2015-04-01

    Thermal activation of persulfate (PS) has been identified to be effective in the destruction of organic pollutants. The feasibility of carbon tetrachloride (CT) degradation in the thermally activated PS system was evaluated. The experimental results showed that CT could be readily degraded at 50°C with a PS concentration of 0.5M, and CT degradation and PS consumption followed the pseudo-first order kinetic model. Superoxide radical anion (O2(-)) was the predominant radical species responsible for CT degradation and the split of CCl was proposed as the possible reaction pathways for CT degradation. The process of CT degradation was accelerated by higher PS dose and lower initial CT concentration. No obvious effect of the initial pH on the degradation of CT was observed in the thermally activated PS system. Cl(-), HCO3(-), and humic acid (HA) had negative effects on CT degradation. In addition, the degradation of CT in the thermally activated PS system could be significantly promoted by the solvents addition to the solution. In conclusion, the thermally activated PS process is a promising option in in-situ chemical oxidation/reduction remediation for degrading highly oxidized organic contaminants such as CT that is widely detected in contaminated sites. PMID:25544995

  13. Interaction of fragmented double-stranded DNA with carbon nanotubes in aqueous solution

    NASA Astrophysics Data System (ADS)

    Gladchenko, G. O.; Karachevtsev, M. V.; Leontiev, V. S.; Valeev, V. A.; Glamazda, A. Yu.; Plokhotnichenko, A. M.; Stepanian, S. G.

    Aqueous suspensions of ultrasonically fragmented double-stranded (fds-) DNA and single-walled carbon nanotubes (SWNTs) have been investigated by UV- and IR-absorption, NIR-emission and Raman spectroscopy. According to gel-electrophoresis, the lengths of the polymer fragments were 100-500 base pairs. Analysis of IR and UV data indicates the presence of both double-stranded (ds) and single-stranded (ss)-regions in the fragments. SWNT complex with DNA was revealed by NIR-emission and Raman spectroscopy. It turned out that fds-DNA is less efficient in holding nanotubes in the aqueous solution than ss-DNA. From the UV-data, the character of the helix-coil transition is seen to be like that for fds-DNA off and on nanotube, however, DNA thermostability increased in this latter case. The effective charge density on the DNA sugar-phosphate backbone of the fds-DNA:SWNT hybrid was less than that of DNA alone. Spectroscopic data can be explained by a model in which the formation of hybrids starts due to the interaction between untwisted ss-regions of DNA and the nanotube: the strands wrap on the tube and thus create an 'anchor' for the whole polymer. The ds-part of the polymer is located close to the nanotube.

  14. Removal of boron from aqueous solution using magnetic carbon nanotube improved with tartaric acid

    PubMed Central

    2014-01-01

    Boron removal capacity of multi-walled carbon nanotubes (MWCNTs) modified with tartaric acid was investigated in this study. Modification of MWCNTs with tartaric acid was confirmed by Boehm surface chemistry method and fourier transform infra-red (FT-IR) spectroscopy. Experiments were performed to determine the adsorption isotherm and adsorption thermodynamic parameters of boron adsorption on tartaric acid modified MWCNTs (TA-MWCNTs). The effect of variables including initial pH, dosage of adsorbent, contact time and temperature was investigated. Analysis of data showed that adsorption equilibrium could be better described by Freundlich isotherm and the maximum adsorption capacities obtained at the pH of 6.0 was 1.97 mg/g. The estimated thermodynamic values of free energy (?G°), entropy (?S°) and enthalpy (?H°) indicated a spontaneous and an endothermic process. Furthermore, the TA-MWCNTs was magnetized for separation of boron-contaminated adsorbent from aqueous solution by applying magnetic field. The results showed that magnetic TA-MWCNTs particles were separated effectively after adsorption from contaminated water. PMID:24393401

  15. Characteristics of cesium ion sorption from aqueous solution on bentonite- and carbon nanotube-based composites.

    PubMed

    Yang, Shubin; Han, Cho; Wang, Xiangke; Nagatsu, Masaaki

    2014-06-15

    The technology development of Cs(+) capture from aqueous solution is crucial for the disposal of nuclear waste and still remains a significant challenge. Previous researches have been proven that ion exchanges with the cations and hydroxyl exchange are the main sorption mechanisms for Cs(+). Therefore, how important are the cation exchange and the hydroxyl exchange mechanisms to Cs(+) sorption? And whether can we improve the sorption capacity of the material by increasing the amount of hydroxyl groups? With these in mind, we herein designed the chitosan-grafted carbon nanotubes (CS-g-CNTs) and the chitosan-grafted bentonite (CS-g-bentonite) by plasma-induced grafting method. The interactions of Cs(+) with CNTs, bentonite, CS-g-CNTs and CS-g-bentonite composites were investigated. The sorption of Cs(+) is mainly dominated by strong cation exchange in monovalent Group I and divalent Group II. And the cation-exchange mechanism is much more effective than the hydroxyl group exchange. The effect of hydroxyl groups is dependent on the property of the matrix. We cannot improve the Cs adsorption capacity of material for Cs(+) only by increasing the amount of hydroxyl groups in any case. The spatial structure and the cation-exchange capacity of the material are important factors for choosing the sorbent for Cs(+) removal from radioactive waste water. PMID:24762700

  16. Adsorption of Acid Red 57 from aqueous solutions onto polyacrylonitrile/activated carbon composite.

    PubMed

    El-Bindary, Ashraf A; Diab, Mostafa A; Hussien, Mostafa A; El-Sonbati, Adel Z; Eessa, Ahmed M

    2014-04-24

    The adsorption of Acid Red 57 (AR57) onto Polyacrylonitrile/activated carbon (PAN/AC) composite was investigated in aqueous solution in a batch system with respect to contact time, pH and temperature. Physical characteristics of (PAN/AC) composite such as fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were obtained. Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were determined. The activation energy of adsorption was also evaluated for the adsorption of AR57 onto (PAN/AC) composite. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data. The dynamic data fitted the pseudo-second-order kinetic model well. The activation energy, change of free energy, enthalpy and entropy of adsorption were also evaluated for the adsorption of AR57 onto (PAN/AC) composite. The thermodynamics of the adsorption indicated spontaneous and exothermic nature of the process. The results indicate that (PAN/AC) composite could be employed as low-cost material for the removal of acid dyes from textile effluents. PMID:24463242

  17. Organic compounds in olive mill wastewater and in solutions resulting from hydrothermal carbonization of the wastewater.

    PubMed

    Poerschmann, J; Weiner, B; Baskyr, I

    2013-09-01

    Organic components in olive mill wastewater (OMW) were analyzed by exhaustive solvent extraction of the lyophilisate followed by pre-chromatographic derivatization techniques and GC/MS-analysis of the extracts. Simple biophenols including tyrosol (Tyr), hydroxytyrosol (OH-Tyr) and homovanillic alcohol as well as complex biophenols including decarbomethoxy ligostride aglycon and decarbomethoxy oleuropein aglycon proved most abundant analytes. Hydroxylated benzoic and cinnamic acids are less abundant, which may indicate a humification process to have occurred. The pattern of organic components obtained from native OMW was compared with that obtained from hydrothermal carbonization (HTC) of the waste product. Former results provided strong evidence that HTC of OMW at 220°C for 14h results in an almost complete hydrolysis of complex aglycons. However, simple biophenols were not decomposed on hydrothermal treatment any further. Phenol and benzenediols as well as low molecular weight organic acids proved most abundant analytes which were generated due to HTC. Similarly to aglycons, lipids including most abundant acylglycerines and less abundant wax esters were subjected almost quantitatively to hydrolysis under hydrothermal conditions. Fatty acids (FAs) released from lipids were further decomposed. The pathways of volatile analytes in both native OMW and aqueous HTC solutions were studied by solventless headspace-Solid Phase Micro Extraction. Basically, a wide array low molecular alcohols and ketones occurring in native OMW survived the HTC process. PMID:23648325

  18. Washing of the AN-107 entrained solids

    SciTech Connect

    GJ Lumetta; FV Hoopes

    2000-03-31

    This report describes the results of a test conducted by Battelle to assess the effects of inhibited water washing on the composition of the entrained solids in the diluted AN-107 low-activity waste (LAW) sample. The objective of this work was to gather data on the solubility of the AN-107 entrained solids in 0.01 M NaOH, so that BNFL can evaluate whether these solids require caustic leaching.

  19. 7 CFR 3201.51 - Parts wash solutions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...manual or automatic cleaning systems. Such systems include, but are not limited to, soak vats and tanks, cabinet washers, and ultrasonic cleaners. (b) Minimum biobased content. The preferred procurement product must have a minimum biobased...

  20. 7 CFR 3201.51 - Parts wash solutions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...manual or automatic cleaning systems. Such systems include, but are not limited to, soak vats and tanks, cabinet washers, and ultrasonic cleaners. (b) Minimum biobased content. The preferred procurement product must have a minimum biobased...

  1. The radiation induced chemistry of uranyl cation in aqueous carbonate –bicarbonate solutions as followed by NMR spectroscopy

    SciTech Connect

    McNamara, Bruce K.; Snow, Lanee A.; Soderquist, Chuck Z.; Sinkov, Sergei I.; Cho, Herman M.; Friese, Judah I.

    2006-05-01

    Alpha radiation induced formation of hydrogen peroxide in carbonate ?bicarbonate media was followed by 13C NMR using dissolved [233UO2(13CO3)3]4- as the alpha source (Dalpha= 12.1 Gy/hr). Between the pH region between 5.9 and 11.6 hydrogen peroxide causes a varied speciation of the uranyl carbonates that is a function of the uranium, carbonate and the hydrogen peroxide concentrations. It is shown that the speciation of the peroxy carbonates (or other species) formed in solution by titration with hydrogen peroxide are common to those formed by hydrogen peroxide generated by radiolysis. The radiolysis experiment was carried out above pH = 9.96 to minimize the loss of 13CO2 over a 2800 hr period. Radiolytic generation of hydrogen peroxide was followed by formation of a uranyl peroxy carbonate complex and complex formation accelerated for about 1200 hours. Complex formation was observed to terminate at a concentration between 1x10-4 and 5x10-4 M. It is assumed that either a steady state H2O2 production rate was established in solution or that some limiting feature of the experiment was responsible for slowing the yield of product.

  2. Carbon capture and storage in the U.S. : a sinking climate solution

    E-print Network

    Henschel, Rachel Hockfield

    2009-01-01

    Coal-fired power plants produce half of the United States' electricity and are also the country's largest emitter of carbon dioxide, the greenhouse gas responsible for climate change. Carbon Capture and Storage (CCS) is a ...

  3. Stress corrosion cracking of X-60 line pipe steel in a carbonate-bicarbonate solution

    SciTech Connect

    Pilkey, A.K.; Lambert, S.B.; Plumtree, A. (Univ. of Waterloo, Ontario (Canada). Dept. of Mechanical Engineering)

    1995-02-01

    An experimental system was developed to reproduce stress corrosion cracking (SCC) of API X-60 line pipe steels in highly alkaline (pH = 10) carbonate-bicarbonate (1 N sodium carbonate [Na[sub 2]CO[sub 3

  4. Multi-instrumental characterization of carbon nanotubes dispersed in aqueous solutions

    EPA Science Inventory

    Previous studies showed that the dispersion extent and physicochemical properties of carbon nanotubes are highly dependent upon the preparation methods (e.g., dispersion methods and dispersants). In the present work, multiwalled carbon nanotubes (MWNTs) are dispersed in aqueous s...

  5. Food Worker Hand Washing Practices: An Observation Study

    Microsoft Academic Search

    LAURA R. GREEN; CAROL A. SELMAN; VINCENT RADKE; DANNY RIPLEY; JAMES C. MACK; DAVID W. REIMANN; TAMMI STIGGER; MICHELLE MOTSINGER; LISA BUSHNELL

    2006-01-01

    Improvement of food worker hand washing practices is critical to the reduction of foodborne illness and is dependent upon a clear understanding of current hand washing practices. To that end, this study collected detailed observational data on food worker hand washing practices. Food workers (n 321) were observed preparing food, and data were recorded on specific work activities for which

  6. Application of Chinese Ink Wash Drawing in Product Design

    NASA Astrophysics Data System (ADS)

    Wang, Qin; Huang, Qiming; Qin, Chuan

    Based on the analysis of the art of Chinese Ink Wash Drawing style, then explains the purpose and meaning of the study for product design with Ink Wash Drawing, in the end combined with actual cases, describes the application of product design using Chinese Ink Wash Drawing.

  7. Remediation of arsenic-contaminated soils and washing effluents

    Microsoft Academic Search

    Min Jang; Jung Sung Hwang; Sang Il Choi; Jae Kwang Park

    2005-01-01

    Laboratory experiments were conducted to determine the distribution of various arsenic species in tailings and soils. Other specific goal of the tests were to evaluate the extraction efficiency of arsenic using alkaline or acid washing, to determine optimum operational parameters of alkaline washing, and to evaluate the arsenic precipitation of washing effluents by pH adjustment or ferric chloride addition. Alkaline

  8. Assessment and optimization of an ultrasound-assisted washing process using organic solvents for polychlorinated biphenyl-contaminated soil.

    PubMed

    Bezama, Alberto; Flores, Alejandra; Araneda, Alberto; Barra, Ricardo; Pereira, Eduardo; Hernández, Víctor; Moya, Heriberto; Konrad, Odorico; Quiroz, Roberto

    2013-10-01

    The goal of this work was to evaluate a washing process that uses organic solutions for polychlorinated biphenyl (PCB)-contaminated soil, and includes an ultrasound pre-treatment step to reduce operational times and organic solvent losses. In a preliminary trial, the suitability of 10 washing solutions of different polarities were tested, from which three n-hexane-based solutions were selected for further evaluation. A second set of experiments was designed using a three-level Taguchi L27 orthogonal array to model the desorption processes of seven different PCB congeners in terms of the variability of their PCB concentration levels, polarity of the washing solution, sonication time, the ratio washing solution/soil, number of extraction steps and total washing time. Linear models were developed for the desorption processes of all congeners. These models provide a good fit with the results obtained. Moreover, statistically significant outcomes were achieved from the analysis of variance tests carried out. It was determined that sonication time and ratio of washing solution/soil were the most influential process parameters. For this reason they were studied in a third set of experiments, constructed as a full factorial design. The process was eventually optimized, achieving desorption rates of more than 90% for all congeners, thus obtaining concentrations lower than 5 ppb in all cases. The use of an ultrasound-assisted soil washing process for PCB-contaminated soils that uses organic solvents seems therefore to be a viable option, especially with the incorporation of an extra step in the sonication process relating to temperature control, which is intended to prevent the loss of the lighter congeners. PMID:23771880

  9. Influence of KOH solution on the hydration and carbonation of high alumina cement mortars

    Microsoft Academic Search

    F. Puertas; L. Fernández-Carrasco; M. T. Blanco-Varela; T. Vázquez; A. Fuente

    1996-01-01

    The influence of KOH presence on the evolution of hydration and carbonation of high alumina cement mortars at two different curing temperatures (4 and 40 °C) has been studied. It has been confirmed that hydration reactions at both temperatures are accelerated with KOH presence and it has a great influence on hydrated and carbonated species. The massive deposition of carbonation

  10. Toward a zero-carbon energy policy in Europe: defining a viable solution

    SciTech Connect

    Jones, Christopher; Glachant, Jean-Michel

    2010-04-15

    The present pace of carbon emission is not sustainable. Human societies need to react and to change. A rational responsive policy to deliver the required carbon emission reduction can be delineated if the key objective parameters are identified and addressed. This article attempts to lay the groundwork for a viable carbon energy policy for Europe. (author)

  11. Molecular-scale Hydrophilicity Induced by Solute: Molecular-thick Charged Pancakes of Aqueous Salt Solution on Hydrophobic Carbon-based Surfaces

    NASA Astrophysics Data System (ADS)

    Shi, Guosheng; Shen, Yue; Liu, Jian; Wang, Chunlei; Wang, Ying; Song, Bo; Hu, Jun; Fang, Haiping

    2014-10-01

    We directly observed molecular-thick aqueous salt-solution pancakes on a hydrophobic graphite surface under ambient conditions employing atomic force microscopy. This observation indicates the unexpected molecular-scale hydrophilicity of the salt solution on graphite surfaces, which is different from the macroscopic wetting property of a droplet standing on the graphite surface. Interestingly, the pancakes spontaneously displayed strong positively charged behavior. Theoretical studies showed that the formation of such positively charged pancakes is attributed to cation-? interactions between Na+ ions in the aqueous solution and aromatic rings on the graphite surface, promoting the adsorption of water molecules together with cations onto the graphite surface; i.e., Na+ ions as a medium adsorbed to the graphite surface through cation-? interactions on one side while at the same time bonding to water molecules through hydration interaction on the other side at a molecular scale. These findings suggest that actual interactions regarding carbon-based graphitic surfaces including those of graphene, carbon nanotubes, and biochar may be significantly different from existing theory and they provide new insight into the control of surface wettability, interactions and related physical, chemical and biological processes.

  12. Structural properties of ZnO nanowires directly grown on a carbon film in ZnCl2 aqueous solution

    NASA Astrophysics Data System (ADS)

    Choi, Hyung Woo; Theodore, N. David; Das, Sayantan; Dhar, Aritra; Alford, T. L.

    2014-11-01

    We have investigated the nucleation and growth of single crystal ZnO nanowires on carbon films. ZnO nanostructures were grown on a transmission electron microscopy (TEM) grid consisting of a carbon film supported by a copper frame. No seed layer was used to provide nucleation sites. The resulting ZnO nanowires showed different diameters and lengths for growth on metal versus the carbon film. This is indicative of differences in nucleation and growth processes that depend on the substrate that was used. Our results indicate that ZnO nanowire arrays can be grown on carbon films by using a ZnCl2 growth solution. This is a simple and low-cost method for growth of the nanowires. The method can also be used for investigating the mechanisms and morphology of ZnO growth on such carbon-based substrates. The growth of ZnO nanowires on carbon films, ribbons or nanodots has potential application for use in sensors, electronic, optoelectronic and photovoltaic devices.

  13. Dielectric properties of some components of fruit aroma in carbon tetrachloride solution at 298.15 K.

    PubMed

    Rudan-Tasic, D; Jurca, S; Klofutar, C

    2000-01-01

    The static electric permittivity and refractive index of carbon tetrachloride solutions of ethyl-2-methyl butanoate, 3-hexene-l-ol, 2-hexenal, ethyldecanoate, methyl anthranilate, anethole, damascenone and isoamyl propanoate were measured at 298.15 K in the concentration range up to 4.0 mol dm-3. The molar polarizations and refractions of the solutions, the partial molar polarizations and refractions of the solutes, as well as the dipole moments at infinite dilution of the solutes were calculated. On the basis of the concentration dependence of apparent values of the square of the molecular dipole moment, it was established that for the systems studied oligomeric species with low dipole moment were prevalent. With the assumption that the dipole moment of dimeric species amounts to zero (except for 3-hexene-l-ol and methyl anthranilate), the constant of dimerization was calculated and a weak molecular association was deduced. PMID:11383137

  14. A new method for the study of trace element partitioning between calcium carbonate and aqueous solution: A test case for Sr and Ba incorporation into calcite

    Microsoft Academic Search

    YASUTAKA TERAKADO; MAMI TANIGUCHI

    2006-01-01

    A new experimental method (evaporation method) for calcium carbonate precipitation in aqueous solution was at- tempted in order to develop a convenient and controllable experimental technique for obtaining precise trace element partition coefficients. Calcite crystals were formed by evaporation of H2O from the aqueous mother solution using a dehumidifier, and the consumed Ca ions were supplied from a refill solution

  15. Effect of Na+ impregnated activated carbon on the adsorption of NH4(+)-N from aqueous solution.

    PubMed

    Shi, Mo; Wang, Zhengfang; Zheng, Zheng

    2013-08-01

    Two kinds of activated carbons modified by Na+ impregnation after pre-treatments involving oxidation by nitric acid or acidification by hydrochloric acid (denoted as AC/N-Na and AC/HCl-Na, respectively), were used as adsorbents to remove NH4(+)-N. The surface features of samples were investigated by BET, SEM, XRD and FT-IR. The adsorption experiments were conducted in equilibrium and kinetic conditions. Influencing factors such as initial solution pH and initial concentration were investigated. A possible mechanism was proposed. Results showed that optimal NH4(+)-N removal efficiency was achieved at a neutral pH condition for the modified ACs. The Langmuir isotherm adsorption equation provided a better fit than other models for the equilibrium study. The adsorption kinetics followed both the pseudo second-order kinetics model and intra-particle kinetic model. Chemical surface analysis indicated that Na+ ions form ionic bonds with available surface functional groups created by pre-treatment, especially oxidation by nitric acid, thus increasing the removal efficiency of the modified ACs for NH4(+)-N. Na(+)-impregnated ACs had a higher removal capability in removing NH4(+)-N than unmodified AC, possibly resulting from higher numbers of surface functional groups and better intra-particle diffusion. The good fit of Langmuir isotherm adsorption to the data indicated the presence of monolayer NH4(+)-N adsorption on the active homogenous sites within the adsorbents. The applicability of pseudo second-order and intra-particle kinetic models revealed the complex nature of the adsorption mechanism. The intra-particle diffusion model revealed that the adsorption process consisted not only of surface adsorption but also intra-particle diffusion. PMID:24520687

  16. Standing surface acoustic wave (SSAW)-based cell washing.

    PubMed

    Li, Sixing; Ding, Xiaoyun; Mao, Zhangming; Chen, Yuchao; Nama, Nitesh; Guo, Feng; Li, Peng; Wang, Lin; Cameron, Craig E; Huang, Tony Jun

    2015-01-01

    Cell/bead washing is an indispensable sample preparation procedure used in various cell studies and analytical processes. In this article, we report a standing surface acoustic wave (SSAW)-based microfluidic device for cell and bead washing in a continuous flow. In our approach, the acoustic radiation force generated in a SSAW field is utilized to actively extract cells or beads from their original medium. A unique configuration of tilted-angle standing surface acoustic wave (taSSAW) is employed in our device, enabling us to wash beads with >98% recovery rate and >97% washing efficiency. We also demonstrate the functionality of our device by preparing high-purity (>97%) white blood cells from lysed blood samples through cell washing. Our SSAW-based cell/bead washing device has the advantages of label-free manipulation, simplicity, high biocompatibility, high recovery rate, and high washing efficiency. It can be useful for many lab-on-a-chip applications. PMID:25372273

  17. Electrochemical studies of the film formation on lithium in propylene carbonate solutions under open-circuit conditions

    SciTech Connect

    Geronov, Y.; Schwager, F.; Muller, R.H.

    1981-11-01

    The nature of protective surface layers formed on lithium in propylene carbonate solutions of LiClO/sub 4/ and LiAsF/sub 6/ at open circuit has been investigated by electrochemical pulse measurements. The results are consistent with the fast formation of a compact thin layer resulting from the reaction with residual water. This layer acts as a solid ionic conductor. Slow corrosion or decomposition processes produce a thicker porous overlayer.

  18. Desalination by ammonia–carbon dioxide forward osmosis: Influence of draw and feed solution concentrations on process performance

    Microsoft Academic Search

    Jeffrey R. McCutcheon; Robert L. McGinnis; Menachem Elimelech

    2006-01-01

    Forward (direct) osmosis (FO) using semi-permeable polymeric membranes may be a viable alternative to reverse osmosis as a lower cost and more environmentally friendly desalination technology. The driving force in the described FO process is provided by a draw solution comprising highly soluble gases—ammonia and carbon dioxide. Using a commercially available FO membrane, experiments conducted in a crossflow, flat-sheet membrane

  19. Cobalt-carbon bond disruption enthalpies: The first reliable measurement of a Co-methyl BDE via solution thermochemical methods

    Microsoft Academic Search

    Paul J. Toscano; Allen L. Seligson; Matthew T. Curran; Andrew T. Skrobutt; David C. Sonnenberger

    1989-01-01

    The determination of the strength of the metal-carbon \\/sigma\\/ bonds has become very important because such bonds have been implicated as or demonstrated to be integral components of many homogeneous catalytic cycles. The use of iodinolytic isoperibol solution calorimetry for the measurement of the absolute value of the bond disruption energies, D(Co-R), for pyCo(CH)âR where py=pyridine, DH = the monoanion

  20. Application of micellar enhanced ultrafiltration and activated carbon fiber hybrid processes for lead removal from an aqueous solution

    Microsoft Academic Search

    Guntae Son; Seunghwan Lee

    2011-01-01

    Micellar enhanced ultrafiltration (MEUF) and activated carbon fiber (ACF) hybrid processes were used to investigate the removal\\u000a condition of lead ions and surfactant sodium dodecyl sulfate (SDS) from an aqueous solution. Lead removal efficiency increased\\u000a with the increase of initial surfactant concentration. Molar ratio of lead to SDS up to 1: 5 has shown over 90% removal efficiency\\u000a of lead,

  1. The effect of phosphoric acid on the absorption of carbon dioxide into solutions of methyldiethanolamine

    E-print Network

    Cordi, Eric Marshall

    1991-01-01

    . The specific equipment required for each setup is described below in detail. Kinetic and Mass Transfer Experimental Setup Both the kinetics and mass transfer of the solutions were studied with a liquid batch and a continuous flow of gas through the reactor...: Nitrous Oxide Absorption into MDEA/HsPO4 Solutions . . . 17. Ideal Solution Equilibrium Concentrations at 25'C 18. Comparison of Ideal and Actual Solution pH Values. . 19. Ionic Ratio Criteria for Solutions with Overall Activity Coefficients Less...

  2. Utilization of activated carbon produced from fruit juice industry solid waste for the adsorption of Yellow 18 from aqueous solutions.

    PubMed

    Angin, Dilek

    2014-09-01

    The use of activated carbon obtained from sour cherry (Prunus cerasus L.) stones for the removal of a basic textile dye, which is Yellow 18, from aqueous solutions at different contact times, pH values and solution temperatures was investigated. The surface area and micropore volume of chemically modified activated carbon were 1704 m(2) g(-1) and 0.984 cm(3) g(-1), respectively. The experimental data indicated that the adsorption isotherms were well described by the Langmuir equilibrium isotherm equation and the calculated adsorption capacity was 75.76 mg g(-1) at 318 K. The adsorption kinetic of Yellow 18 obeys the pseudo-second-order kinetic model. The thermodynamic parameters were calculated to estimate the nature of adsorption. The activation energy of the system was calculated as 0.71-2.36 kJ/mol. According to these results, prepared activated carbon could be used as a low-cost adsorbent to compare with the commercial activated carbon for the removal of Yellow 18 from wastewater. PMID:24656549

  3. Preparation of activated carbons from Iris tectorum employing ferric nitrate as dopant for removal of tetracycline from aqueous solutions.

    PubMed

    Li, Gang; Zhang, Dongsheng; Wang, Man; Huang, Ji; Huang, Lihui

    2013-12-01

    Ferric nitrate was employed to modify activated carbon prepared from Iris tectorum during H?PO? activation and ability of prepared activated carbon for removal of tetracycline (TC) was investigated. The properties of the activated carbon samples with or without ferric nitrate, ITAC-Fe and ITAC, were measured by scanning electron microscopy (SEM), N? adsorption/desorption isotherms, Fourier transform infrared spectroscopy (FTIR) and Boehm's titration. The results showed that mixing with iron increased the BET surface area, total pore volume and the adsorption capacity as compared to the original carbon. FTIR and Boehm's titration suggested that ITAC-Fe was characteristic of more acidic functional groups than ITAC. Adsorption of TC on both samples exhibited a strong pH-dependent behavior and adsorption capacity reduced rapidly with the increasing solution pH. The adsorption kinetics agreed well with the pseudo-second-order model and the adsorption isotherms data were well described by Langmuir model with the maximum adsorption capacity of 625.022 mg/g for ITAC and 769.231 mg/g for ITAC-Fe. The present work suggested that ITAC-Fe could be used to remove tetracycline effectively from aqueous solutions. PMID:24021870

  4. Adsorption of the complex ion Au(CN)2- onto sulfur-impregnated activated carbon in aqueous solutions.

    PubMed

    Ramírez-Muñiz, Kardia; Song, Shaoxian; Berber-Mendoza, Selene; Tong, Shitang

    2010-09-15

    The adsorption of the gold-cyanide complex ion (Au(CN)(2)(-)) on sulfur-impregnated activated carbon in aqueous solution has been studied in order to find a better adsorbent for the gold cyanidation process for extracting gold from ores. This study was performed using sulfur-impregnated activated carbon (SIAC 8.0) made from high-sulfur petroleum coke and an artificial aqueous solution of Au(CN)(2)(-). The experimental results have shown that Au(CN)(2)(-) strongly adsorbed onto the SIAC 8.0, leading the gold adsorption capacity of the SIAC 8.0 to be 2.25x that on conventional activated carbon. It has been also found that the adsorption fit the Langmuir isotherm well, and the adsorption density of Au(CN)(2)(-) on the SIAC 8.0 in aqueous solution increased with increasing temperature, suggesting chemical adsorption. The chemical adsorption might be attributed to the formation of S-Au-CN on SIAC 8.0 surfaces through the covalent bond between the gold atom of the ion and the sulfur in the molecular structure of the SIAC 8.0. In addition, the desorption test has demonstrated that the majority of the adsorption was irreversible, which depended on the density of the adsorption sites on the SIAC. PMID:20580375

  5. Carbon nanotubes and graphene in aqueous surfactant solutions : molecular simulations and theoretical modeling

    E-print Network

    Lin, Shangchao

    2012-01-01

    This thesis describes combined molecular simulations and theoretical modeling studies, supported by experimental observations, on properties and applications of carbon nanotubes (CNTs) and graphene sheets dispersed in ...

  6. Remediation of cadmium- and lead-contaminated agricultural soil by composite washing with chlorides and citric acid.

    PubMed

    Li, Yu-Jiao; Hu, Peng-Jie; Zhao, Jie; Dong, Chang-Xun

    2015-04-01

    Composite washing of cadmium (Cd)- and lead (Pb)-contaminated agricultural soil from Hunan province in China using mixtures of chlorides (FeCl3, CaCl2) and citric acid (CA) was investigated. The concentrations of composite washing agents for metal removal were optimized. Sequential extraction was conducted to study the changes in metal fractions after soil washing. The removal of two metals at optimum concentration was reached. Using FeCl3 mixed with CA, 44 % of Cd and 23 % of Pb were removed, and 49 and 32 % by CaCl2 mixed with CA, respectively. The mechanism of composite washing was postulated. A mixture of chlorides and CA enhanced metal extraction from soil through the formation of metal-chloride and metal-citrate complexes. CA in extract solutions promoted the formation of metal-chloride complexes and reduced the solution pH. Composite washing reduced Cd and Pb in Fe-Mn oxide forms significantly. Chlorides and CA exerted a synergistic effect on metal extraction during composite washing. PMID:25342453

  7. Characterization of lead removal from contaminated soils by nontoxic soil-washing agents.

    PubMed

    Neilson, Julia W; Artiola, Janick F; Maier, Raina M

    2003-01-01

    Few effective strategies exist for remediating and restoring metal-contaminated soils. We have evaluated the potential of two environmentally compatible, nondestructive, biological soil-washing agents for remediating aged, lead-contaminated soils. Two contaminated soils were washed with 10 mM rhamnolipid biosurfactant and 5.3% carboxymethyl-beta-cyclodextrin (CMCD). The metal removal efficiency of these agents was compared with 10 mM diethylenetriamine pentaacetic acid (DTPA) and 10 mM KNO3. Lead removal rates by both soil-washing agents exceeded the removal by KNO3, but were an order of magnitude less than removal by the synthetic chelator, DTPA. Analysis of soil extractions revealed that the Pb in the first soil (3780 mg kg(-1)) was primarily associated with the soluble, exchangeable, oxide, and residual fractions while the Pb in the second soil (23 900 mg kg(-1)) was found in the soluble, exchangeable, carbonate, and residual fractions. After 10 consecutive washes, rhamnolipid had removed 14.2 and 15.3% of the Pb from the first and second soils, respectively, and CMCD had removed 5 and 13.4% from the same two soils. The Pb removal rate by both agents either increased or was consistent throughout the 10 extractions, indicating a potential for continued removal with extended washing. Significant levels of Cu and Zn in both soils did not prevent Pb removal by either agent. Interestingly, the effectiveness of each agent varied as a function of Pb speciation in the soil. Rhamnolipid was more effective than CMCD in removing Pb bound to amorphous iron oxides, while both agents demonstrated similar potential for removing soluble, exchangeable, and carbonate-bound Pb. Neither agent demonstrated potential for the complete remediation of metal-contaminated soils. PMID:12809290

  8. Influence of hydrophobic substance on enhancing washing durability of water soluble flame-retardant coating

    NASA Astrophysics Data System (ADS)

    Jindasuwan, Sunisa; Sukmanee, Nattinee; Supanpong, Chanida; Suwan, Mantana; Nimittrakoolchai, On-uma; Supothina, Sitthisuntorn

    2013-06-01

    Flame-retardant textiles are used in many consumer products. Among halogen-free flame retardant substances, inorganic flame retardants are mainly based on phosphorus, antimony, aluminum and boron-containing compounds. These coatings are soluble in water and therefore are not subjected to washing. In this study, washing durability of the inorganic flame retardant has been improved by incorporation of the hydrophobic substance to the coating. Composition of the coating which is the flame-retardant, monoammonium phosphate (MAP), and the hydrophobic substances, poly(methylhydrogen siloxane) (PMHS) and poly(dimethyl siloxane) (PDMS)), were varied to find the optimum coating solution. The results of SEM and TGA analysis, as well as the burning and washing tests, revealed that the coating solution consisting of MAP:PMHS:PDMS = 5:2:1 wt.% was the optimum condition. It showed the increased residue on the TGA profile compared to the uncoated sample, and self-extinguish after removal of the ignition source. The flame-retardant property can be maintained after washing, making it feasible for variety of applications.

  9. Study On Adsorption of Bromate From Aqueous Solution On Modified Activated Carbon

    Microsoft Academic Search

    Tong-Mian Liu; Fu-Yi Cui; Zhi-Wei Zhao; Dong-Mei Liu; Qi Zhu; Huan Wang

    2010-01-01

    A coal-based activated carbon was treated chemically with nitric acid, sodium hydroxide and ammonia for its surface modification, and its adsorption capacity was investigated with bromate. Several techniques were used to characterize the physicochemical properties of these materials including BET, XPS, pHpzc and Boehm titration. The results indicated that the specific surface area of the activated carbon decreased after oxidation

  10. Axial Dispersion during Hanford Saltcake Washing

    SciTech Connect

    Josephson, Gary B.; Geeting, John GH; Lessor, Delbert L.; Barton, William B.

    2006-08-01

    Clean up of Hanford salt cake wastes begins with dissolution retrieval of the sodium rich salts that make up the dominant majority of mass in the tanks. Water moving through the porous salt cake dissolves the soluble components and also displaces the soluble radionuclides (e.g. 137Cs and 99TcO4- ). The separation that occurs from this displacement, known as Selective dissolution, is an important component in Hanford’s pretreatment of low activity wastes for subsequent Supplemental treatment. This paper describes lab scale testing conducted to evaluate Selective dissolution of cesium from non-radioactive Hanford tank 241-S-112 salt cake simulant containing the primary chemicals found the the actual tank. An modified axial dispersion model with increasing axial dispersion was developed to predict cesium removal. The model recognizes that water dissolves the salt cake during washing, which causes an increase in the axial dispersion during the wash. This model was subsequently compared with on-line cesium measurements from the retrieval of tank 241-S-112. The model had remarkably good agreement with both the lab scale and full scale data.

  11. Equilibrium adsorption studies of some aromatic pollutants from dilute aqueous solutions on activated carbon at different temperatures

    SciTech Connect

    Khan, A.R.; Ataullah, R.; Al-Haddad, A. [Kuwait Univ., Safat (Kuwait). Dept. of Chemical Engineering] [Kuwait Univ., Safat (Kuwait). Dept. of Chemical Engineering

    1997-10-01

    Aqueous solutions of phenol, p-chlorophenol, and p-nitrophenol have been used to determine the adsorption isotherm for single solute systems on activated carbon at different temperatures. The experimental program has been conducted to investigate the influence of concentration and temperature. All the reported equilibrium isotherm equations have been tried on present and published experimental data. A generalized isotherm equation which was proposed by Khan et al. and tested for bi-solute adsorption data has been modified for single-solute system. The temperature dependency has also been incorporated into a generalized equation. It has been noticed that the Radke and Prausnitz and generalized isotherm equations could represent the entire data with a minimum average percentage error. The influence of different adsorbents, sorbate concentrations, and pH of aqueous solutions has also been discussed in detail. The temperature dependency has been investigated using both the Dubinin-Astakov and the modified generalized equation. The generalized equation describes the experimental and published data adequately and provides a single value of differential molar heat of adsorption, {Delta}H{sub ads}, for a single solute adsorption system. The Dubinin-Astakov isotherm equation has shown an increasing trend of {Delta}H{sub ads} as the loading of adsorbent has increased.

  12. Removal of Pb and MDF from contaminated soils by EDTA- and SDS-enhanced washing.

    PubMed

    Zhang, Weihua; Tsang, Daniel C W; Lo, Irene M C

    2007-02-01

    Heavy metal- and organic-contaminated sites are ubiquitous, but few studies have been conducted to address such an issue. EDTA- and SDS-enhanced washing was studied for remediation of Pb- and/or marine diesel fuel (MDF)-contaminated soils. The feasibility of recovery and reuse of EDTA and SDS, as well as the physicochemical interactions among the chemical agents, contaminants and soils were extensively investigated using batch experiments. The optimal washing sequence was then determined. The experimental results showed that EDTA could be recovered and reused for four cycles without significant loss of its chelating capacity, while the extraction capability of SDS was noticeably reduced after each reuse cycle. The free phase of marine diesel fuel (MDF) in soils physically isolated the sorbed Pb on soils and thus reducing its extraction by EDTA. The presence of SDS alone or together with low concentration of EDTA was found to enhance Pb removal probably via electrostatic interaction and dissolution of soil organic matter. However, it hindered Pb extraction by high concentration of EDTA, because of the potential formation of complexes between some strongly-bound Pb and SDS, that are more resistant to desorption. Therefore, EDTA washing followed by SDS achieved the highest Pb removal efficiency. On the other hand, MDF removal by SDS was significantly hindered by coexisting Pb in soils, probably because the formation of Pb-dodecyl sulfate (DS) complex would decrease the effective amount of SDS available for forming micelles in solution and enhance MDF sorption. EDTA alone or together with SDS could enhance MDF removal, but the residual MDF after EDTA-washing became more resistant to SDS removal. Consequently, SDS washing followed by EDTA is considered as the optimal washing sequence for MDF removal. PMID:17123574

  13. Simultaneous removal of NO and SO 2 with hexamminecobalt(II) solution coupled with the hexamminecobalt(II) regeneration catalyzed by activated carbon

    Microsoft Academic Search

    Xiang-Li Long; Zhi-Ling Xin; Hong-Xin Wang; Wen-De Xiao; Wei-Kang Yuan

    2004-01-01

    The wet ammonia desulfurization process can be retrofitted for combined removal of SO2 and NO from the flue gases by adding soluble cobalt(II) salt into the aqueous ammonia solution. Activated carbon is used to catalyze the reduction of hexamminecobalt(III) to hexamminecobalt(II) to maintain the capability of removing NO of the hexamminecobalt solution. The effects of temperature, pH, activated carbon particle

  14. Temperature effects on the performance of PMAN-derived carbon anodes in 1M LiPF{sub 6}/EC-DMC solution

    SciTech Connect

    Guidotti, R.A.; Johnson, B.J.

    1998-04-01

    The effect of temperature on the reversible and irreversible capacities of disordered carbons derived from polymethacryonitrile (PMAN) and divinylbenzene (DVB) copolymers was studied in 1 M LiPF{sub 6}/ethylene carbonate (EC)-dimethyl carbonate (DMC) (1:1 v/v) solution by galvanostatic cycling. The kinetics of passive film formation were examined by complex-impedance spectroscopy. Temperatures of 5, 21, and 35 C were used in the study.

  15. Activated carbon from industrial solid waste as an adsorbent for the removal of Rhodamine-B from aqueous solution: Kinetic and equilibrium studies

    Microsoft Academic Search

    K. Kadirvelu; C. Karthika; N. Vennilamani; S. Pattabhi

    2005-01-01

    The activated carbon was prepared using industrial solid waste called sago waste and physico-chemical properties of carbon were carried out to explore adsorption process. The effectiveness of carbon prepared from sago waste in adsorbing Rhodamine-B from aqueous solution has been studied as a function of agitation time, adsorbent dosage, initial dye concentration, pH and desorption. Adsorption equilibrium studies were carried

  16. Immersion freezing of birch pollen washing water

    NASA Astrophysics Data System (ADS)

    Augustin, Stefanie; Hartmann, Susan; Pummer, Bernhard; Grothe, Hinrich; Niedermeier, Dennis; Clauss, Tina; Voigtländer, Jens; Tomsche, Laura; Wex, Heike; Stratmann, Frank

    2013-04-01

    Up to now, the importance of pollen for atmospheric ice nucleation was considered to be minor, as they are too large to stay in the atmosphere for a long time. But as recent investigations have shown, not the pollen grains themselves are responsible for freezing, but easily suspendable macromolecules on their surfaces (Pummer et al., 2012). Due to the bursting of pollen grains these ice nucleating active (INA) macromolecules could be numerous in the atmosphere. In the present study, the immersion freezing behavior of birch pollen, i.e. its ice nucleating active (INA) macromolecules, was investigated at the Leipzig Aerosol Cloud Interaction Simulator (LACIS, Hartmann et al., 2011). For this, washing water of two different birch pollen samples with different origin (Northern birch and Southern birch) were used. Immersion freezing of droplets generated from the pollen washing water was observed at temperatures higher than -20 °C for both samples. The main difference between the Northern and the Southern birch pollen was the temperature dependence of the immersion freezing process. Our results suggest that the ice nucleating potential of the Southern birch is controlled by a single type of INA macromolecule, while the Northern birch pollen seem to feature two distinctively different types of INA macromolecules. We determined the heterogeneous nucleation rates for both INA macromolecule types and thereby consistently describe the ice nucleation behavior of both, the Southern and the Northern birch pollen washing water. Furthermore we will suggest a theoretical framework for describing e.g. single INA macromolecule related ice nucleation in atmospheric models. References: Pummer, B. G., Bauer, H., Bernardi, J., Bleicher, S. and Grothe, H.: Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollen. Atmos. Chem. Phys., 12, 2541-2550, doi:10.5194/acp-12-2541-2012, 2012. Hartmann, S., Niedermeier, D., Voigtländer, J., Clauss, T., Shaw, R. A., Wex, H., Kiselev, A., and Stratmann, F.: Homogeneous and heterogeneous ice nucleation at LACIS: operating principle and theoretical studies, Atmos. Chem. Phys., 11, 1753-1767, doi:10.5194/acp-11-1753-2011, 2011.

  17. The Adsorption of Gold, Palladium, and Platinum from Acidic Chloride Solutions on Mesoporous Carbons

    SciTech Connect

    Peter R. Zalupski; Rocklan McDowell

    2014-10-01

    Studies on the adsorption characteristics of gold, palladium, and platinum on mesoporous carbon (CMK-3) and sulfur-impregnated mesoporous carbon (CMK-3/S) evaluated the benefits/drawbacks of the presence of a layer of elemental sulfur inside mesoporous carbon structures. Adsorption isotherms collected for Au(III), Pd(II), and Pt(IV) on those materials suggest that sulfur does enhance the adsorption of those metal ions in mildly acidic environment (pH 3). The isotherms collected in 1 M HCl show that the benefit of sulfur disappears due to the competing influence of large concentration of chloride ions on the ion-exchanging mechanism of metal ions sorption on mesoporous carbon surfaces. The collected acid dependencies illustrate similar adsorption characteristics for CMK-3 and CMK-3/S in 1-5MHCl concentration range. Sorption of metal ions from diluted aqueous acidic mixtures of actual leached electronic waste demonstrated the feasibility of recovery of gold from such liquors.

  18. Water recycle method for washing alkali-refined soybean oil

    Microsoft Academic Search

    R. A. Eisenhauer; R. E. Beal; E. L. Griffin

    1970-01-01

    Vegetable oil refineries are faced today with cutting down on pollution caused by their waste water. A method was developed\\u000a for washing alkali-refined soybean oil with treated, recirculated wash water. In this method, wash water passes through a\\u000a cation exchange resin that removes Na, and the slightly acid water goes back into the system for continuous reuse. The disposal\\u000a problem

  19. Sunflower-Oil Wax Reduction by Seed Solvent Washing

    Microsoft Academic Search

    Erica R. Baümler; Guillermo H. Crapiste; Amalia A. Carelli

    2007-01-01

    Wax distribution in sunflower seeds was determined by capillary-gas chromatography, as well as both the wax composition in\\u000a sunflower oils obtained from washed seeds and the wax composition in the solvent extracts. The dehulling efficiency was evaluated\\u000a by using a laboratory centrifugal process. The washing effect on hull morphology and on wax distribution was observed by scanning-electron\\u000a microscopy. Washing preferentially

  20. High adsorption capacity NaOH-activated carbon for dye removal from aqueous solution.

    PubMed

    Wu, Feng-Chin; Tseng, Ru-Ling

    2008-04-15

    In this study, the surface coverage ratio (Sc/Sp) and monolayer cover adsorption amount per unit surface area (qmon/Sp) were employed to investigate the adsorption isotherm equilibrium of the adsorption of dyes (AB74, BB1 and MB) on NaOH-activated carbons (FWNa2, FWNa3 and FWNa4); the adsorption rate of the Elovich equation (1/b) and the ratio of 1min adsorption amount of adsorbate to the monolayer cover amount of adsorbate (q1/qmon) were employed to investigate adsorption kinetics. The qmon/Sp of NaOH-activated carbons was better than that of KOH-activated carbons prepared from the same raw material (fir wood). The Sc/Sp values of the adsorption of all adsorbates on adsorbent FWNa3 in this study were found to be higher than those in related literature. Parameters 1/b and q1 of the adsorption of dyes on activated carbons in this study were higher than those on KOH-activated carbons; the q1/qmon value of FWNa3 was the highest. The pore structure and the TPD measurement of the surface oxide groups were employed to explain the superior adsorption performance of FWNa3. A high surface activated carbon (FWNa3) with excellent adsorption performance on dyes with relation to adsorption isotherm equilibrium and kinetics was obtained in this study. Several adsorption data processing methods were employed to describe the adsorption performance. PMID:17826897

  1. Risk of needle tract seeding of breast cancer: cytological results derived from core wash material.

    PubMed

    Uematsu, Takayoshi; Kasami, Masako

    2008-07-01

    Needle track seeding has been recognized as a possible, albeit rare, complication of breast core needle biopsy. The purpose of this study was to assess the risk of needle tract seeding of breast cancer from cytological results derived from core needle wash material. The study included biopsies of 207 breast cancers performed using ultrasonographically guided 18-gauge core needles. Each core needle without exposed sample notch was washed in saline solution immediately after removing the needles. Cytology derived from core wash material was performed by saline solution lavage of the fragments using a cytocentrifuge. The cytological diagnoses were divided into five categories: benign, atypical/indeterminate, suspicious/probably malignant, malignant and unsatisfactory. Atypical/indeterminate, suspicious/probably malignant and malignant categories were considered to represent positive cases of needle track seeding of breast cancer, whereas benign and unsatisfactory categories were counted as negative cases. Cytological diagnoses of the 207 lesions were as follows: 26 lesions (12%) were benign, 18 lesions (9%) were atypical/indeterminate, 37 lesions (18%) were suspicious/probably malignant, 79 lesions (38%) were malignant, and 47 lesions (23%) were unsatisfactory. The incidence of positive cases of cytology derived from core wash material was 65% (134/207). The 25% frequency of positive cases of invasive lobular carcinoma was significantly lower than the frequencies of DCIS (74%) and invasive ductal carcinoma (69%) (P = 0.001 and P < 0.01). The frequency of positive cases in the multiple passes group was 75%, which was slightly, although not significantly, higher than the 66% frequency in the single pass group (P = 0.3). In conclusion, the incidence of positive cases of cytology derived from ultrasonographically guided breast core needles' wash material was 65%. The clinical significance is debatable; however, there may be a theoretical risk of local recurrence if the tract is not excised or radiotherapy not given. PMID:17674195

  2. EFRT M-12 Issue Resolution: Solids Washing

    SciTech Connect

    Baldwin, David L.; Schonewill, Philip P.; Toth, James J.; Huckaby, James L.; Eslinger, Paul W.; Hanson, Brady D.; Kurath, Dean E.; Minette, Michael J.

    2010-01-01

    Pacific Northwest National Laboratory (PNNL) was tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed, and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes” of the External Flowsheet Review Team (EFRT) issue response plan.( ) The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing.

  3. Origin of gasoline-range hydrocarbons and their migration by solution in carbon dioxide in Norton basin, Alaska.

    USGS Publications Warehouse

    Kvenvolden, K.A.; Claypool, G.E.

    1980-01-01

    Carbon dioxide from a submarine seep in Norton Sound carries a minor component of gas- and gasoline-range hydrocarbons. The molecular and isotopic compositions of the hydrocarbon gases and the presence of gasoline-range hydrocarbons indicate that these molecules are derived from thermal alteration of marine and/or nonmarine organic matter buried within Norton basin. The gasoline-range hydrocarbon distribution suggests that the hydrocarbon mixture is an immature petroleum-like condensate of lower temperature origin than normal crude oil. The submarine seep provides a natural example in support of a carbon dioxide solution transport mechanism thought to be operative in the migration of hydrocarbons in certain reservoirs.-Authors

  4. Geochemical and C, O, Sr, and U-series isotopic evidence for the meteoric origin of calcrete at Solitario Wash, Crater Flat, Nevada, USA

    Microsoft Academic Search

    L. A. Neymark; J. B. Paces; B. D. Marshall; Z. E. Peterman; J. F. Whelan

    2005-01-01

    Calcite-rich soils (calcrete) in alluvium and colluvium at Solitario Wash, Crater Flat, Nevada, USA, contain pedogenic calcite\\u000a and opaline silica similar to soils present elsewhere in the semi-arid southwestern United States. Nevertheless, a ground-water\\u000a discharge origin for the Solitario Wash soil deposits was proposed in a series of publications proposing elevation-dependent\\u000a variations of carbon and oxygen isotopes in calcrete samples.

  5. The performance of a surface-applied corrosion inhibitor for the carbon steel in saturated Ca(OH){sub 2} solutions

    SciTech Connect

    Zheng, Haibing [Qingdao Technological University, Qingdao 266033 (China)] [Qingdao Technological University, Qingdao 266033 (China); Li, Weihua, E-mail: liweihua@qdio.ac.cn [Qingdao Technological University, Qingdao 266033 (China) [Qingdao Technological University, Qingdao 266033 (China); Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Ma, Fubin [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China)] [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Kong, Qinglin [University of Melbourne, Melbourne 3010 (Australia)] [University of Melbourne, Melbourne 3010 (Australia)

    2014-01-15

    In the present work, the performance of an amino alcohol based surface applied inhibitor was studied by the electrochemical techniques in saturated Ca(OH){sub 2} solutions. The surface morphology of the carbon steel was observed by scanning electron microscope, and the energy diffraction spectrum was also tested. Results showed that the inhibitor used in this work demonstrated obvious inhibition efficiency on the carbon steel in saturated Ca(OH){sub 2} solutions. The inhibition mechanism of the inhibitor lies in the quick adsorption of the active component on carbon steel surface.

  6. Study On Adsorption of Bromate From Aqueous Solution On Modified Activated Carbon

    NASA Astrophysics Data System (ADS)

    Liu, Tong-mian; Cui, Fu-yi; Zhao, Zhi-wei; Liu, Dong-mei; Zhu, Qi; Wang, Huan

    2010-11-01

    A coal-based activated carbon was treated chemically with nitric acid, sodium hydroxide and ammonia for its surface modification, and its adsorption capacity was investigated with bromate. Several techniques were used to characterize the physicochemical properties of these materials including BET, XPS, pHpzc and Boehm titration. The results indicated that the specific surface area of the activated carbon decreased after oxidation with nitric acid. But the amount of surface acidic oxygen-containing functional groups of the oxidized sample increased compared to the raw carbon and the points of zero charge (pHpzc) decreased. The specific surface area of the activated carbon also decreased after sodium hydroxide treatment and the points of zero charge increased. The changes of surface chemical properties after the ammonia treatment was opposite to the oxidized sample. As a result, the pHpzc of the carbon was increased to near pH9.3, the amount of surface basic groups was increased. Furthermore, the data of bromate adsorption on all the samples were fitted to the Langmuir isotherm model well which indicates monolayer adsorption. In addition, the adsorption capacity of ammonia treatment sample was the highest and its saturated adsorption capacity reached 1.55 mg/g. A strong correlation was found between basic groups and adsorption capacity of bromate. Enhancement of basic groups was favorable for bromate removal.

  7. Fundamental Effects of Aging on Creep Properties of Solution-Treated Low-Carbon N-155 Alloy

    NASA Technical Reports Server (NTRS)

    Frey, D N; Freeman, J W; White, A E

    1950-01-01

    A method is developed whereby the fundamental mechanisms are investigated by which processing, heat treatment, and chemical composition control the properties of alloys at high temperatures. The method used metallographic examination -- both optical and electronic --studies of x-ray diffraction-line widths, intensities, and lattice parameters, and hardness surveys to evaluate fundamental structural conditions. Mechanical properties at high temperatures are then measured and correlated with these measured structural conditions. In accordance with this method, a study was made of the fundamental mechanism by which aging controlled the short-time creep and rupture properties of solution-treated low-carbon n-155 alloy at 1200 degrees F.

  8. Radiation-induced grafting of multi-walled carbon nanotubes in glycidyl methacrylate maleic acid binary aqueous solution

    NASA Astrophysics Data System (ADS)

    Yu, Haibo; Mo, Xinyue; Peng, Jing; Zhai, Maolin; Li, Jiuqiang; Wei, Genshuan; Zhang, Xiaohong; Qiao, Jinliang

    2008-05-01

    With the aim to improve the compatibility between multi-walled carbon nanotubes (MWCNTs) and nylon-6, purified MWCNTs ( p-MWCNTs) were grafted successfully with glycidyl methacrylate-maleic acid in aqueous solution using a single-step radiation method. The chemical structure and morphology of grafted p-MWCNTs ( g-MWCNTs) was investigated by micro-FTIR, Raman spectroscopy and transmission electron microscopy. The prepared nylon-6/ g-MWCNTs composite has higher mechanical strength and heat distortion temperature due to improved dispersion and compatibility than those of nylon-6/ p-MWCNTs.

  9. Sludge pretreatment chemistry evaluation: Enhanced sludge washing separation factors

    SciTech Connect

    Colton, N.G.

    1995-03-01

    This report presents the work conducted in Fiscal Year 1994 by the Sludge Pretreatment Chemistry Evaluation Subtask for the Tank Waste Remediation System (TWRS) Tank Waste Treatment Science Task. The main purpose of this task, is to provide the technical basis and scientific understanding to support TWRS baseline decisions and actions, such as the development of an enhanced sludge washing process to reduce the volume of waste that will require high-level waste (HLW) vitrification. One objective within the Sludge Pretreatment Chemistry Evaluation Subtask was to establish wash factors for various SST (single-shell tank) sludges. First, analytical data were compiled from existing tank waste characterization reports. These data were summarized on tank-specific worksheets that provided a uniform format for reviewing and comparing data, as well as the means to verify whether the data set for each tank was complete. Worksheets were completed for 27 SST wastes. The analytical water wash data provided tank-specific information about the fraction of each component that dissolves with water, i.e., an estimate of tank-specific wash factors for evaluating tank-by-tank processing. These wash data were then used collectively to evaluate some of the wash factors that are assumed for the overall SST waste inventory; specifically, wash factors for elements that would be found primarily in sludges. The final step in this study was to incorporate the characterization and wash factor data into a spreadsheet that provides insight into the effect of enhanced sludge washing on individual tank sludges as well as for groups of sludges that may be representative of different waste types. Spreadsheet results include the estimated mass and percentage of each element that would be removed with washing and leaching. Furthermore, estimated compositions are given of the final wash and leach streams and residual solids, in terms of both concentration and dry weight percent.

  10. The effect of fatal carbon monoxide poisoning on the equilibria between cell membranes and the electrolyte solution.

    PubMed

    Petelska, Aneta D; Koty?ska, Joanna; Figaszewski, Zbigniew A

    2015-02-01

    The effect of fatal carbon monoxide poisoning on equilibria between cell membranes and surrounding ions was described using a theoretical four-equilibria model. The model was developed to obtain parameters characterizing the interactions between solution ions and erythrocyte or thrombocyte membrane surface. The parameters are the total surface concentrations of both acidic and basic groups C A, C B and their association constants with solution ions K AH, K BOH. These parameters were used to calculate the theoretical values of surface charge density. The model was validated by comparison of these values to experimental data, which were determined from the electrophoretic mobility measurements of the blood cells. The experimental and theoretical surface charge density values agree at pH 2-8, and at higher pH, the deviation was observed. PMID:25416423

  11. Thin Fluoropolymer Films and Nanoparticle Coatings from the Rapid Expansion of Supercritical Carbon Dioxide Solutions with Electrostatic Collection.

    SciTech Connect

    Fulton, John L.; Deverman, George S.; Yonker, Clement R.; Grate, Jay W.; Deyoung, James; Mcclain, James B.

    2003-03-12

    Application of nanometer thick fluoropolymer films to substrates ranging from microelectronic components to cardiovascular implants is described. In the first step, nanometer-sized polymer particles are generated during the rapid expansion of supercritical fluid solutions. These particles are then charged as they are being formed by application of a high voltage to the expansion nozzle. The charged particles are forced to a solid surface forming uniform coatings with thicknesses from 10?s of nanometers to several micrometers thick. Supercritical carbon dioxide solutions of three different fluoropolymers were used to generate different types of coatings. The method can also be used to generate a solid matrix with nanometer size domains of two chemically diverse solid materials. The size of the particles are so small that they can be deposited to electrically conducting microscopic regions with a spatial resolution better than 50 nm.

  12. The Solubility Product of NaUO2PO4.xH2O Determined in Phosphate and Carbonate Solutions

    SciTech Connect

    Felmy, Andrew R.; Xia, Yuanxian; Wang, Zheming

    2005-07-01

    The solubility product of NaUO2PO4.xH2O was determined in phosphate containing solutions at low pCH+ values in the absence of carbonate and at higher pCH+ values in the presence of carbonate. NaUO2PO4.xH2O exhibited very low solubilities (~10-7 M in U) over a broad range of hydrogen ion concentrations, NaNO3 concentrations and in the absence of added carbonate. Time Resolved Laser Fluorescence Spectroscopy (TRLFS) analysis of non-carbonate solutions outside of the acidic region revealed the presence of complex mixtures of aqueous U(VI) hydroxyl or phosphate species and uranium phosphate nanoparticles. The presence of the nanoparticles made it impossible to accurately calculate a solubility product for NaUO2PO4.xH2O in the absence of carbonate and at higher pCH+ values. Therefore in order to increase the concentration of U(VI) in solution and thereby verify the solubility product calculated from the most acidic samples, we systematically introduced know concentrations of carbonate, which resulted in the formation of U(VI) carbonate complexes. Development of an accurate aqueous thermodynamic model for the aqueous U(VI) carbonate complexes then allowed calculation of a solubility product for NaUO2PO4.xH2O in the higher pH samples which was in good agreement with the values for the more acidic samples.

  13. Tuning indium tin oxide work function with solution-processed alkali carbonate interfacial layers for high-efficiency inverted organic photovoltaic cells

    NASA Astrophysics Data System (ADS)

    Chen, Fei; Chen, Qi; Mao, Lin; Wang, Yixin; Huang, Xun; Lu, Wei; Wang, Bing; Chen, Liwei

    2013-12-01

    Selective electron collection by an interfacial layer modified indium tin oxide cathode is critically important for achieving high-efficiency inverted structure organic photovoltaic (OPV) cells. Here, we demonstrate that solution-processed alkali carbonates, such as Li2CO3, Na2CO3, K2CO3, Rb2CO3, Cs2CO3, are good interfacial layer materials. Both carbonate concentration and annealing conditions can affect cathode work function and surface roughness. By proper optimization, different alkali carbonates can be almost equally effective as the cathode interfacial layer. Furthermore, good device performance can be achieved at a low annealing temperature (<50?° C), which allows for potential applications in solution-processed inverted OPV cells on plastic substrates. This work indicates that alkali carbonates, not just cesium carbonate, are valid choices as the cathode interlayer in inverted OPV devices.

  14. Adsorption of uranium (VI) from aqueous solution using a novel graphene oxide-activated carbon felt composite.

    PubMed

    Chen, Shuiping; Hong, Jianxun; Yang, Hongxiao; Yang, Jizhen

    2013-12-01

    Graphene oxide(GO)-activated carbon felt(ACF)(GO-ACF) composite was prepared by an electrophoretic deposition and subsequent thermal annealing. The structures of GO and GO-ACF were characterized by FT-IR, Raman spectra and XPS. The adsorption capacities for U(VI) from aqueous solution of ACF and GO-ACF were compared. The essential factors affected U(VI) adsorption such as initial pH, contact time and temperature were investigated. The adsorption is highly dependent on the solution pH. In addition, the adsorption isotherm and thermodynamics were investigated. The adsorptions of U(VI) from aqueous solution on GO-ACF were fitted to the Langmuir and, Freundlich adsorption isotherms. The adsorption of U(VI) could be well-described by Langmuir. The adsorption of U(VI) on ACF is remarkably improved by GO covalently bonding with ACF. The maximum sorption capacity of GO-ACF for U(VI) was evaluated to be 298 mg/g at pH 5.5, much higher than that of ACF (173 mg/g), suggesting the carboxyl functional groups of GO-ACF playing important roles in the sorption. Thermodynamic parameters further show that the sorption is an endothermic and spontaneous process. GO-ACF is a powerful promising sorbent for the efficient removal of U(VI) from aqueous solutions. PMID:24090965

  15. Degradation of p-nitrophenol in aqueous solution by microwave assisted oxidation process through a granular activated carbon fixed bed.

    PubMed

    Bo, Longli; Quan, Xie; Chen, Shuo; Zhao, Huimin; Zhao, Yazhi

    2006-09-01

    A microwave (MW) assisted oxidation process was investigated for degradation of p-nitrophenol (PNP) from aqueous solution. The process consisted of a granular activated carbon (GAC) fixed bed reactor, a MW source, solution and air supply system, and a heat exchanger. The process was operated in continuous flow mode. Air was applied for oxygen supply. GAC acted as a MW energy absorption material as well as the catalyst for PNP degradation. MW power, air flow, GAC dose, and influent flow proved to be major factors which influenced PNP degradation. The results showed that PNP was degraded effectively by this new process. Under a given condition (PNP concentration 1330mg/L, MW power 500 W, influent flow 6.4 mL/min, air flow 100 mL/min), PNP removed 90%, corresponding to 80% of TOC removal. The pathway of PNP degradation was deduced based on GC-MS identification of course products. PNP experienced sequential oxidation steps and mineralized ultimately. Nitro-group of PNP converted to nitrite and nitrate. Biodegradability of the solution was improved apparently after treatment by MW assisted oxidation process, which benefit to further treatment of the solution using biochemical method. PMID:16904722

  16. EPA SITE DEMONSTRATION OF THE BIOTROL SOIL WASHING PROCESS

    EPA Science Inventory

    A pilot-scale soil washing process, patented by BioTrol, Inc., was demonstrate on soil contaminated by wood treating waste, primarily pentachlorophenol (PCP) and creosote-derived polynuclear aromatic hydrocarbons (PAHs). Although soil washing was the main object of this demonstra...

  17. BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING NORTHWEST. PIPING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING NORTHWEST. PIPING IN FOREGROUND IS NOT RELATED TO THE MACHINE. THE NORTHEAST CORNER OF SETTLING RESERVOIR NO. 3 IS SEEN AT THE LOWER LEFT. - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

  18. BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING WEST. THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING WEST. THE NONHISTORIC CHEMICAL BUILDING IS SEEN IN THE BACKGROUND. - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

  19. 2. VIEW OF WASH TANKS Skins are brought in through ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF WASH TANKS Skins are brought in through hatches, seen on rear wall, and washed of blood and flesh in redwood tanks, with wooden grates to hold skins down in water. Superstructure and screening on tanks are a later alteration, unrelated to this process. - Sealing Plant, St. George Island, Pribilof Islands, Saint George, Aleutians West Census Area, AK

  20. Critique of the AEC Reactor Safety Study (WASH1400)

    Microsoft Academic Search

    F. L. Leverenz; R. C. Erdmann

    1975-01-01

    This report contains a critical commentary of the Reactor Safety Study, (WASH-1400). The substance of the report accumulated from attempts to use the methods and results contained in WASH-1400 for resolving other reactor safety issues. Only areas where the SAI staff had competence were carefully reviewed. Generally, it is felt that the original study group did a remarkable job in

  1. WASH-1400: a comparison of experience and prediction

    SciTech Connect

    Lellouche, G.S.

    1981-05-01

    In an Electric Power Research Institute report, it was concluded that the error bounds in WASH-1400, the Reactor Safety Study, although perhaps understated, are not necessarily ''greatly understated,'' as claimed by the Lewis Committee. The relationship between an experimental data base for operating light water reactors (LWRs) and the predictions of WASH-1400 are examined. 5 refs.

  2. WASH1400: a comparison of experience and prediction

    Microsoft Academic Search

    Lellouche

    1981-01-01

    In an Electric Power Research Institute report, it was concluded that the error bounds in WASH-1400, the Reactor Safety Study, although perhaps understated, are not necessarily ''greatly understated,'' as claimed by the Lewis Committee. The relationship between an experimental data base for operating light water reactors (LWRs) and the predictions of WASH-1400 are examined. 5 refs.

  3. Wash room, bunkhouse, first floor interior. This room is a ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Wash room, bunkhouse, first floor interior. This room is a screened porch with the original sinks extant. Light and ventilation was borrowed from the wash room into the toilets and bathing rooms. - Sespe Ranch, Bunkhouse, 2896 Telegraph Road, Fillmore, Ventura County, CA

  4. 1. VIEW LOOKING WEST AT CHINA WASH FLUME ON MAIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW LOOKING WEST AT CHINA WASH FLUME ON MAIN CANAL. - San Carlos Irrigation Project, China Wash Flume, Main (Florence-Case Grande) Canal at Station 137+00, T4S, R10E, S14, Coolidge, Pinal County, AZ

  5. 2. VIEW LOOKING NORTHWEST AT CHINA WASH FLUME ON MAIN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW LOOKING NORTHWEST AT CHINA WASH FLUME ON MAIN CANAL - San Carlos Irrigation Project, China Wash Flume, Main (Florence-Case Grande) Canal at Station 137+00, T4S, R10E, S14, Coolidge, Pinal County, AZ

  6. Adsorption of polyoxyethylene alkyl-phenols onto calcium carbonate from aqueous solution

    Microsoft Academic Search

    R. J. Akers; P. M. Riley

    1974-01-01

    The adsorption of polyoxyethylene alkyl-phenols onto calcium carbonate has previously been reported by Kuno and Abe. A similar series of experiments has been conducted and substantilly different results obtained. The data are summarized in tabular form. The surface areas covered per molecule are calculated on the basis of the mean molecular weight and the nitrogen adsorption BET isotherm for the

  7. Carbon Tax Revenue and the Budget Deficit: A Win-Win-Win Solution?

    E-print Network

    Rausch, Sebastian

    Bush-era tax cuts are scheduled to expire at the end of 2012, leading to interest in raising revenue through a carbon tax. This revenue could be used to either cut other taxes or to avoid cuts in Federal programs. There ...

  8. The influence of sodium carbonate on sodium aluminosilicate crystallisation and solubility in sodium aluminate solutions

    Microsoft Academic Search

    Kali Zheng; Andrea R. Gerson; Jonas Addai-Mensah; Roger St. C. Smart

    1997-01-01

    Isothermal batch precipitation experiments have been carried out in synthetic Bayer liquors to investigate the effects of sodium carbonate concentration on both silica solubility and the crystallisation of sodium aluminosilicates. At both 90 and 160°C cancrinite (generically defined as a sodium aluminosilicate of space group P63) is the stable solid phase. Sodalite (generically defined as a sodium aluminosilicate with space

  9. Removal of copper from aqueous solution by carbon nanotube\\/calcium alginate composites

    Microsoft Academic Search

    Yanhui Li; Fuqiang Liu; Bing Xia; Qiuju Du; Pan Zhang; Dechang Wang; Zonghua Wang; Yanzhi Xia

    2010-01-01

    With bulk production and increasing application of carbon nanotubes (CNTs) as adsorbents in wastewater treatment, they will eventually be discharged into water environment and result in human contact risk to these toxic materials. However, so far few attentions have been paid to resolve the environmental micro-pollution caused by these micro-sized CNTs. In this research, an environmental friendly adsorbent, CNTs immobilized

  10. Adsorption isotherms of phenolic compounds from aqueous solutions onto activated carbon fibers

    Microsoft Academic Search

    Ruey-Shin Juang; Feng-Chin Wu; Ru-Ling Tseng

    1996-01-01

    Phenolic compounds exist widely in the industrial effluents such as those from oil refineries and the coal tar, plastics, leather, paint, pharmaceutical, and steel industries. Since they are highly toxic and are, in general, not amenable to biological degradation, methods of treatment are continuously being modified and developed. Liquid-phase adsorption equilibria of eight phenolic compounds onto activated carbon fibers were

  11. Adsorption of Pyridine from Aqueous Solution by Surface Treated Carbon Nanotubes

    Microsoft Academic Search

    Bo Zhao; Duan Qiu

    2007-01-01

    The surface treatment of multi?walled carbon nanotubes (MWCNTs) with acid, heat, ultrasonic, and polyvinyl alcohol has been examined. The original CNTs and four treated CNTs were first used as adsorbents to remove pyridine from water and the adsorption isotherms of pyridine on CNTs were studied. At the same time, the effect of pH, temperature, and the adsorption kinetics on the

  12. The adsorption of gold, palladium and platinum from acidic chloride solutions on mesoporous carbons.

    SciTech Connect

    Peter Zalupski; Rocklan McDowell; Guy Dutech

    2014-10-01

    Studies on the adsorption characteristics of gold, palladium and platinum on mesoporous carbon (CMK-3) and sulfur-impregnated mesoporous carbon (CMK-3/S) evaluated the benefits/drawbacks of the presence of a layer of elemental sulfur inside mesoporous carbon structures. Adsorption isotherms collected for Au(III), Pd(II) and Pt(IV) on those materials suggest that sulfur does enhance the adsorption of those metal ions in mildly acidic environment (pH 3). The isotherms collected in 1 M HCl show that the benefit of sulfur disappears due to the competing influence of large concentration of hydrogen ions on the ion-exchanging mechanism of metal ions sorption on mesoporous carbon surfaces. The collected acid dependencies illustrate similar adsorption characteristics for CMK-3 and CMK-3/S in 1-5 M HCl concentration range. Sorption of metal ions from diluted aqueous acidic mixtures of actual leached electronic waste demonstrated the feasibility of recovery of gold from such liquors.

  13. Removal of arsenite and arsenate ions from aqueous solution by basic yttrium carbonate

    Microsoft Academic Search

    Syed A. Wasay; Akira Uchiumi; Shuzo Tokunaga

    1996-01-01

    A new method has been developed to remove arsenite and arsenate ions from aquatic systems by using basic yttrium carbonate (BYC). Various parameters such as pH, anion concentration and reaction time were studied to establish optimum conditions. The removal by adsorption of arsenite and arsenate ions was found to be > 99% depending on initial concentration in the pH range

  14. ANION AND CATION REMOVAL FROM SOLUTION USING ACTIVATED CARBONS FROM MUNICIPAL SLUDGE AND POULTRY MANURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The removal of potentially toxic metal cations and anions from water is essential to providing safe water for consumption and recreation. The objective of this study was to evaluate the ability of activated carbons made from municipal sludge and poultry manure to remove certain metal cations and an...

  15. Transport of carbon, nitrogen, phosphorus, and major solutes in the Gambia River, West Africa

    Microsoft Academic Search

    LANCE F. W. LESACK; ROBERT E. HECKY; JOHN M. MELACK

    1984-01-01

    Transport of solutes and particulate materials and their variation with discharge were studied for 1 year (July 1980-June 1981) in the Gambia River in the tropical savanna of West Africa. The water is a dilute solution of SiOâ and HCOâ⁻. Na\\/sup +\\/, K\\/sup +\\/, Cl⁻, and total dissolved nitrogen showed no significant relation with discharge. Ca\\/sup 2 +\\/, Mg\\/sup 2

  16. VANADIUM51, CARBON13 AND PROTON FTNMR STUDIES ON VANADIUM (V) SPECIES IN AQUEOUS SOLUTIONS

    Microsoft Academic Search

    MAHMOUD ADAM H HABAYEB

    1981-01-01

    The solution chemistry of the Stretford Process--a liquid redox, cyclic process employed to efficiently remove hydrogen sulfide from sour gases--is not fully understood. The intent of the present work is to investigate the speciation of metavanadate ions in aqueous and in Stretford-like solutions; the interactions between vanadium (V) species and several oxygen- and nitrogen-donating ligands and the molecular microdynamics of

  17. Combination of surfactant enhanced soil washing and electro-Fenton process for the treatment of soils contaminated by petroleum hydrocarbons.

    PubMed

    Huguenot, David; Mousset, Emmanuel; van Hullebusch, Eric D; Oturan, Mehmet A

    2015-04-15

    In order to improve the efficiency of soil washing treatment of hydrocarbon contaminated soils, an innovative combination of this soil treatment technique with an electrochemical advanced oxidation process (i.e. electro-Fenton (EF)) has been proposed. An ex situ soil column washing experiment was performed on a genuinely diesel-contaminated soil. The washing solution was enriched with surfactant Tween(®) 80 at different concentrations, higher than the critical micellar concentration (CMC). The impact of soil washing was evaluated on the hydrocarbons concentration in the leachates collected at the bottom of the soil columns. These eluates were then studied for their degradation potential by EF treatment. Results showed that a concentration of 5% of Tween(®) 80 was required to enhance hydrocarbons extraction from the soil. Even with this Tween(®) 80 concentration, the efficiency of the treatment remained very low (only 1% after 24 h of washing). Electrochemical treatments performed thereafter with EF on the collected eluates revealed that the quasi-complete mineralization (>99.5%) of the hydrocarbons was achieved within 32 h according to a linear kinetic trend. Toxicity was higher than in the initial solution and reached 95% of inhibition of Vibrio fischeri bacteria measured by Microtox(®) method, demonstrating the presence of remaining toxic compounds even after the complete degradation. Finally, the biodegradability (BOD5/COD ratio) reached a maximum of 20% after 20 h of EF treatment, which is not enough to implement a combined treatment with a biological treatment process. PMID:25646675

  18. Analytical determination of pollutant wash-off parameters

    SciTech Connect

    Millar, R.G. [Univ. of British Columbia, Vancouver, British Columbia (Canada). Dept. of Civil Engineering] [Univ. of British Columbia, Vancouver, British Columbia (Canada). Dept. of Civil Engineering

    1999-10-01

    The wash-off algorithm in the Storm Water Management Model has been widely used to simulate the wash off of sediment and pollutants from impervious areas. This algorithm indicates an exponential relationship between pollutant wash off and runoff volume. To simulate water quality, the initial mass of sediment or pollutant at the beginning of the storm and an empirical wash-off coefficient need to be determined. A simple analytical technique is developed for evaluating these parameters from measured water quality and runoff data. The proposed method is based on an expression of the exponential wash-off equation in terms of concentration rather than pollutant mass, and it can be applied to parameter evaluation without recourse to complex numerical models or optimization techniques.

  19. Isotopic geochemistry of the Saratoga springs: Implications for the origin of solutes and source of carbon dioxide

    NASA Astrophysics Data System (ADS)

    Siegel, Donald I.; Lesniak, Keri A.; Stute, Martin; Frape, Shaun

    2004-03-01

    We report the results of an isotopic study designed to determine the source of solutes and carbon dioxide in the famed Saratoga Springs (New York) mineral waters. These waters have thousands of milligrams per liter total dissolved solid concentrations and are highly charged with carbon dioxide gas. The spring waters are cold (˜12 °C) and there is no local, deep-seated thermal anomaly. They emerge through thick shale caprock along the surface expression of normal faults. The ?13C (-5.8‰ to +0.8‰ Vienna Peedee belemnite) of the dissolved inorganic carbon and elevated 3He/4He ratios suggest that the source of the CO2 is the mantle or an ancient deep crystallized igneous melt. The stable isotopic content of the spring waters defines a mixing line between modern local meteoric waters (? ˜ 70‰) and a component with heavier ?D but similar ?18O values. This trend and that of 87Sr/86Sr of dissolved strontium versus 1/Sr are consistent with the hypothesis that Canadian Shield type brines contribute salinity to the springs. These brines plausibly migrate from the Adirondack Mountains to the topographically low McGregor fault system in the Hudson River lowlands, where the Saratoga springs discharge.

  20. Adsorption of anionic and cationic dyes on ferromagnetic ordered mesoporous carbon from aqueous solution: equilibrium, thermodynamic and kinetics.

    PubMed

    Peng, Xiaoming; Huang, Dengpo; Odoom-Wubah, Tareque; Fu, Dafang; Huang, Jiale; Qin, Qingdong

    2014-09-15

    Ordered mesoporous carbon (Fe-CMK-3) with iron magnetic nanoparticles was prepared by a casting process via SBA-15 silica as template and anthracene as carbon source, was used as a magnetic adsorbent for the removal of anionic dye Orange II (O II) and cationic dye methylene blue (MB) from aqueous solution. TEM and magnetometer images showed that the iron magnetic nanoparticles were successfully embedded in the interior of the mesoporous carbon. The effect of various process parameters such as temperature (25-45°C), initial concentration (100-500 mg L(-1)) and pH (2-12) were performed. Equilibrium adsorption isotherms and kinetics were also studied. The equilibrium experimental data were analyzed by the Langmuir, Freundlich, Temkin and Redlich-Peterson model. The equilibrium data for two dyes adsorption was fitted to the Langmuir, and the maximum monolayer adsorption capacity for O II and MB dyes were 269 and 316 mg g(-1), respectively. Pseudo-first-order and pseudo-second-order kinetic and intraparticle diffusion model were used to evaluate the adsorption kinetic data. The kinetic data of two dyes could be better described by the pseudo second-order model. Thermodynamic data of the adsorption process were also obtained. It was found that the adsorption process of the two dyes were spontaneous and exothermic. PMID:24973701

  1. Synthesis of mesoporous magnetic Co-NPs/carbon nanocomposites and their adsorption property for methyl orange from aqueous solution.

    PubMed

    Zhang, Peng; An, Qiao; Guo, Jia; Wang, Chang-Chun

    2013-01-01

    Mesoporous magnetic Co-NPs(nanoparticles)/carbon nanocomposites were synthesized by carbonization of polyacrylonitrile (PAN) microspheres entrapped with cobalt salt for the first time. The structure and morphology of the porous magnetic nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and N(2) adsorption-desorption technique. The nanocomposites possess very high saturation magnetization (Ms is up to ~133 emu/g), near-zero remanence, and very low coercivity (Hc is down to ~0.023 KOe). Meanwhile, the nanocomposites have mesoporous structure with average pore size of 4 nm and high specific surface area of 232 m(2)/g, which can be tuned by changing the carbonization conditions. Using methyl orange (MO) as model pollutant in water, the mesoporous magnetic nanocomposites showed good adsorption capacity of 380 mg/g, and the absorbed MO could be easily released in ethanol. The mesoporous nanocomposites were facile separated from solution under external magnetic force, and over 85% adsorption capacity for MO could be retained after five adsorption/desorption cycles. PMID:22975398

  2. Qualification testing and full-scale demonstration of titanium-treated zeolite for sludge wash processing

    SciTech Connect

    Dalton, W.J.

    1997-06-30

    Titanium-treated zeolite is a new ion-exchange material that is a variation of UOP (formerly Union Carbide) IONSIV IE-96 zeolite (IE-96) that has been treated with an aqueous titanium solution in a proprietary process. IE-96 zeolite, without the titanium treatment, has been used since 1988 in the West Valley Demonstration Project`s (WVDP) Supernatant Treatment System (STS) ion-exchange columns to remove Cs-137 from the liquid supernatant solution. The titanium-treated zeolite (TIE-96) was developed by Battelle-Pacific Northwest Laboratory (PNL). Following successful lab-scale testing of the PNL-prepared TIE-96, UOP was selected as a commercial supplier of the TIE-96 zeolite. Extensive laboratory tests conducted by both the WVDP and PNL indicate that the TIE-96 will successfully remove comparable quantities of Cs-137 from Tank 8D-2 high-level radioactive liquid as was done previously with IE-96. In addition to removing Cs-137, TIE-96 also removes trace quantities of Pu, as well as Sr-90, from the liquid being processed over a wide range of operating conditions: temperature, pH, and dilution. The exact mechanism responsible for the Pu removal is not fully understood. However, the Pu that is removed by the TIE-96 remains on the ion-exchange column under anticipated sludge wash processing conditions. From May 1988 to November 1990, the WVDP processed 560,000 gallons of liquid high-level radioactive supernatant waste stored in Tank 8D-2. Supernatant is an aqueous salt solution comprised primarily of soluble sodium salts. The second stage of the high-level waste treatment process began November 1991 with the initiation of sludge washing. Sludge washing involves the mixing of Tank 8D-2 contents, both sludge and liquid, to dissolve the sulfate salts present in the sludge. Two sludge washes were required to remove sulfates from the sludge.

  3. Exposure of brown trout (Salmo trutta L.) to tunnel wash water runoff--chemical characterisation and biological impact.

    PubMed

    Meland, Sondre; Heier, Lene Sørlie; Salbu, Brit; Tollefsen, Knut Erik; Farmen, Eivind; Rosseland, Bjørn Olav

    2010-06-01

    Washing and cleaning of road tunnels are a routinely performed maintenance task, which generate significant amount of polluted wash-water runoff that normally is discharged to the nearest recipient. The present study was designed to quantify chemical contaminants (trace metals, hydrocarbons, PAH and detergents) in such wash water and assess the short term impact on brown trout (Salmo trutta L.) based on in situ experiments. Selected endpoints were accumulation of trace metals in gills, haematological variables and hepatic mRNA transcription of five biomarkers reflecting defence against free radicals, trace metals, planar aromatic hydrocarbons and endocrine disruptions which were measured prior (-3h), during (1 and 3h) and after the tunnel wash (14, 38 and 86h). Our findings showed that the runoff water was highly polluted, but most of the contaminants were associated with particles which are normally considered biologically inert. In addition, high concentrations of calcium and dissolved organic carbon were identified in the wash water, thus reducing metal toxicity. However, compared to the control fish, a rapid accumulation of trace metals in gills was observed. This was immediately followed by a modest change in blood ions and glucose in exposed fish shortly after the exposure start. However, after 38-86h post wash, gill metal concentrations, plasma ions and glucose levels recovered back to control levels. In contrast, the mRNA transcription of the CYP1A and the oxidative stress related biomarkers TRX and GCS did not increase until 14h after the exposure start and this increase was still apparent when the experiment was terminated 86h after the beginning of the tunnel wash. The triggering of the defence systems seemed to have successfully restored homeostasis of the physiological variables measured, but the fish still used energy for detoxification four days after the episode, measured as increased biomarker synthesis. PMID:20381128

  4. Eggshell bacterial contamination of non-washed and washed eggs from caged and cage-free hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the microbiology of non-washed and washed table eggs obtained from caged and cage-free laying hens housed on either all shavings or all wire slat environments. Both Hy-Line W-37 white and Hy-Line brown strains were used. On each of four replication sample days ...

  5. Eggshell bacterial levels of non-washed and washed eggs from caged and cage-free hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The bacteria levels of non-washed and washed eggs obtained from caged and cage-free laying hens housed on either all shavings or all wire slat floors were determined. On eight sample days (from 22 to 52 weeks at 4 week intervals), 20 eggs were collected from each pen (n=120/sample day). Ten eggs p...

  6. Harvest maturity, pre-cutting wash and post-processing dip to improve quality of fresh-cut carambola fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Arkin’ carambola (Averrhoa carambola L.) fruit harvested at color break or full yellow stage were washed with or without an alkaline solution (pH 12), cut to 10 mm slices, dipped in calcium ascorbate (Ca ASA), ascorbic acid (ASA) or water, and packaged in perforated clamshells for up to 14 days sto...

  7. The effectiveness of some washing procedures on the removal of contaminants from plant tissue samples of glasshouse crops

    Microsoft Academic Search

    C. Sonneveld; P. A. van Dijk

    1982-01-01

    Leaf samples of glasshouse crops may be severely contaminated. Five experiments were carried out to determine how the contaminants could best be removed. The effects of the materials and equipment used in the drying and milling of the samples were also investigated.Various washing solutions and methods were compared in the experiments. On the whole, the best results were obtained by

  8. Adsorption of phenolic compounds from aqueous solutions using carbon nanoporous adsorbent coated with polymer

    NASA Astrophysics Data System (ADS)

    Anbia, Mansoor; Ghaffari, Arezoo

    2009-09-01

    Phenolic compounds are a widespread class of water pollutants that are known to cause serious human health problems; and the demand for effective adsorbents for the removal of toxic compounds is increasing. In this work adsorption of phenol, resorcinol and p-cresol on mesoporous carbon material (CMK-1) and modified with polyaniline polymer (CMK-1/PANI) has been investigated in attempt to explore the possibility of using nanoporous carbon as an efficient adsorbent for pollutants. It was found that CMK-1/PANI exhibits significant adsorption for phenolic derivatives. Batch adsorption studies were carried out to study the effect of various parameters like adsorbent dose, pH, initial concentration and contact time. From the sorption studies it was observed that the uptake of resorcinol was higher than other phenolic derivatives. Freundlich and Langmuir adsorption isotherms were used to model the equilibrium adsorption data for phenolic compounds.

  9. Nonideal transport of contaminants in heterogeneous porous media: 10. Impact of co-solutes on sorption by porous media with low organic-carbon contents.

    PubMed

    Brusseau, M L; Schnaar, G; Johnson, G R; Russo, A E

    2012-11-01

    The impact of co-solutes on sorption of tetrachloroethene (PCE) by two porous media with low organic-carbon contents was examined by conducting batch experiments. The two media (Borden and Eustis) have similar physical properties, but significantly different organic-carbon (OC) contents. Sorption of PCE was nonlinear for both media, and well-described by the Freundlich equation. For the Borden aquifer material (OC=0.03%), the isotherms measured with a suite of co-solutes present (1,2-dichlorobenzene, bromoform, carbon tetrachloride, and hexachloroethane) were identical to the isotherms measured for PCE alone. These results indicate that there was no measurable impact of the co-solutes on PCE sorption for this system. In contrast to the Borden results, there was a measurable reduction in sorption of PCE by the Eustis soil (OC=0.38%) in the presence of the co-solutes. The organic-carbon fractions of both media contain hard-carbon components, which have been associated with the manifestation of nonideal sorption phenomena. The disparity in results observed for the two media may relate to relative differences in the magnitude and geochemical nature of these hard-carbon components. PMID:22717163

  10. Nonideal transport of contaminants in heterogeneous porous media: 10. Impact of co-solutes on sorption by porous media with low organic-carbon contents

    PubMed Central

    Brusseau, M.L.; Schnaar, G.; Johnson, G.R.; Russo, A.E.

    2013-01-01

    The impact of co-solutes on sorption of tetrachloroethene (PCE) by two porous media with low organic-carbon contents was examined by conducting batch experiments. The two media (Borden and Eustis) have similar physical properties, but significantly different organic-carbon (OC) contents. Sorption of PCE was nonlinear for both media, and well-described by the Freundlich equation. For the Borden aquifer material (OC = 0.03%), the isotherms measured with a suite of co-solutes present (1,2-dichlorobenzene, bromoform, carbon tetrachloride, and hexachloroethane) were identical to the isotherms measured for PCE alone. These results indicate that there was no measurable impact of the co-solutes on PCE sorption for this system. In contrast to the Borden results, there was a measureable reduction in sorption of PCE by the Eustis soil (OC = 0.38%) in the presence of the co-solutes. The organic-carbon fractions of both media contain hard-carbon components, which have been associated with the manifestation of nonideal sorption phenomena. The disparity in results observed for the two media may relate to relative differences in the magnitude and geochemical nature of these hard-carbon components. PMID:22717163

  11. Sonophotocatalytic degradation of methyl orange by carbon nanotube\\/TiO 2 in aqueous solutions

    Microsoft Academic Search

    Shuo Wang; Qianming Gong; Ji Liang

    2009-01-01

    In this study, carbon nanotubes (CNTs)\\/TiO2 composite were prepared and the sonophotocatalytic activity of CNTs\\/TiO2 nanoparticles was investigated, in which methyl orange (MO) was chosen as an object. The results indicate that the photocatalytic efficiency of CNTs\\/TiO2 remarkable increases in the presence of ultrasound, and the sonophotocatalysis process followed a first-order kinetics. The kinetic constant of CNTs\\/TiO2 for the MO

  12. Adsorption of Pb(II) by Peanut Hull Carbon from Aqueous Solution

    Microsoft Academic Search

    K. Periasamy; C. Namasivayam

    1995-01-01

    Carbon prepared from peanut hulls (PHC) has been used for the adsorption of Pb(II) over a range of initial metal ion concentrations (10–20 mg\\/L), agitation times (5–140 minutes), adsorbent dosages (5–100 mg\\/100 mL), and pH values (1.5–10.0). Adsorption of Pb(II) obeyed the Langmuir isotherm. The applicability of the Lagergren kinetic model has also been investigated. Quantitative removal of 20 mg\\/L

  13. Removal of heavy metal ions from aqueous solutions using carbon aerogel as an adsorbent

    Microsoft Academic Search

    Ajay Kumar Meena; G. K. Mishra; P. K. Rai; Chitra Rajagopal; P. N. Nagar

    2005-01-01

    The removal of Cd(II), Pb(II), Hg(II), Cu(II), Ni(II), Mn(II) and Zn(II) by carbon aerogel has been found to be concentration, pH, contact time, adsorbent dose and temperature dependent. The adsorption parameters were determined using both Langmuir and Freundlich isotherm models. Surface complexation and ion exchange are the major removal mechanisms involved. The adsorption isotherm studies clearly indicated that the adsorptive

  14. Sorption of chlorophenols from aqueous solution by granular activated carbon, filter coal, pine and hardwood

    Microsoft Academic Search

    G. S. M. Hossain; R. G. McLaughlan

    2012-01-01

    Wood and coal, as low-cost sorbents, have been evaluated as an alternative to commercial granular activated carbon (GAC) for chlorophenol removal. Kinetic experiments indicated that filter coal had a significantly lower rate of uptake (? 10% of final uptake was achieved after three hours) than the other sorbents, owing to intra-particle diffusion limitations. The data fitted a pseudo-second-order model. Sorption

  15. Sterilization of Bacillus pumilus spores using supercritical fluid carbon dioxide containing various modifier solutions

    Microsoft Academic Search

    Edison Shieh; Andrzej Paszczynski; Chien M. Wai; Qingyong Lang; Ronald L. Crawford

    2009-01-01

    Supercritical fluid carbon dioxide (SF-CO2) with small amounts of chemical modifier(s) provides a very effective sterilization technique that should be useful for destroying microorganism on heat-sensitive devices such as instruments flown on planetary-bound spacecraft. Under a moderate temperature (50 °C) and pressure (100 atm), spores of Bacillus pumilus strains ATCC 7061 and SAFR 032 can be effectively inactivated\\/eliminated from metal surfaces and

  16. A RIGOROUS MODEL FOR ABSORPTION OF CARBON DIOXIDE INTO AQUEOUS N-METHYLDIETHANOLAMINE SOLUTION

    Microsoft Academic Search

    Yao Shi; Zhantie Zhong

    2005-01-01

    A rigorous model for absorption of carbon dioxide into aqueous N-methyldiethanolamine (MDEA) based on the assumption of reversible reactions and the simplified model with a pseudo-first order irreversible reaction hypothesis were employed to compare with experimental data. The experimental absorption rates were obtained from a characterized double stirred-cell absorber with a planar gas-liquid interface. It was demonstrated that the numerical

  17. Kinetics of absorption of carbon dioxide into aqueous solutions of monoethanolamine+ N-methyldiethanolamine

    Microsoft Academic Search

    Chen-Hung Liao; Meng-Hui Li

    2002-01-01

    Kinetics of the absorption of CO2 into monoethanolamine(MEA)+N-methyldiethanolamine(MDEA)+water were investigated at 30°C,35°C, and 40°C using a laboratory wetted wall column. Ten systems with various MEA concentrations (0.1, 0.2, 0.3, 0.4, and 0.5kmolm?3) mixed with aqueous MDEA (1.0 and 1.5kmolm?3) solutions were studied. Densities and viscosities of the solutions and the solubilities and diffusivities of N2O in the aqueous blended amine

  18. Correlation of mineralogy and trace element leaching behavior in modified in situ spent shales from Logan Wash, Colorado

    SciTech Connect

    Peterson, E.J.; O'Rourke, J.A.; Wagner, P.

    1981-01-01

    Oil shale retorting induces mineral and chemical reactions to occur on the macroscopic and microscopic levels in the kerogen-bearing marlstone. The nature and extent of the reactions is dependent upon process variables such as maximum temperature, time at temperature, atmosphere, and raw shale composition. This report describes the investigation of the mineral, chemical, and trace element release properties of spent shales retrieved from an experimental in situ retort at Occidental Oil Shale, Inc.'s Logan Wash site in Garfield County, Colorado. Correlation between mineralogy of the spent materials and the mobility of major, minor, and trace elements are indicated, and relationships with important process parameters are discussed. The progress of carbonate decomposition reactions and silication reactions is indicative of the processing conditions experienced by the shale materials and influences the mobility of major, minor, and trace elements when the solids are contacted by water. Shale minerals that are exposed to the extreme conditions reached in underground retorting form high temperature product phases including akermanite-gehlenite and diopside-augite solid solutions, kalsilite, monticellite, and forsterie. The persistence of relatively thermally stable phases, such as quartz, orthoclase, and albite provide insight into the extremes of processing conditions experienced by the spent shales. Leachate compositions suggest that several trace elements, including vanadium, boron, fluoride, and arsenic are not rendered immobile by the formation of the high-temperature silicate product phase akermanite-gehlenite.

  19. Effect of activated carbon surface oxygen- and/or nitrogen-containing groups on adsorption of copper(II) ions from aqueous solution

    SciTech Connect

    Biniak, S.; Pakula, M.; Szymanski, G.S.; Swiatkowski, A.

    1999-08-31

    The adsorption properties of a modified activated carbon with various oxygen-and/or nitrogen-containing surface groups toward copper ions was studied. Previously de-ashed and chemically modified commercial activated carbon D-43/1 (carbo-Tech, Essen, Germany) was used. The chemical properties of the modified carbon surface were estimated by standard neutralization titration with HCl, NaOH, and HaOC{sub 2}{sub 5}. The adsorption of Cu{sup 2+} ions on three modified activated carbons from aqueous CuSO{sub 4} solution of various pH was measured. The carbon samples with adsorbed Cu{sup 2+} ions were analyzed by spectroscopic methods (X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy). In addition, an electrochemical measurement (cyclic voltammetry) was performed using powdered activated carbon electrodes. While the modification procedures employed alter the surface only slightly, they strongly influence the surface chemical structure. Basic groups are predominant in the heat-treated samples; acidic functional groups are predominant in the oxidized sample. Both the copper cation adsorption studies and the spectral and electrochemical measurements show that adsorbed ions interact with the carbon surface in different ways. The number of adsorbed ions depends on the nature and quantity of surface acid-base functionalities and on the pH equilibrium in the aqueous solution. The possible mechanisms of interactions between metal ions and carbon surface functionalities are summarized and discussed.

  20. Removal of chlorophenols in aqueous solution by carbon black low-cost adsorbents. Equilibrium study and influence of operation conditions.

    PubMed

    Domínguez-Vargas, Joaquín R; Navarro-Rodríguez, Juan A; de Heredia, Jesús Beltrán; Cuerda-Correa, Eduardo M

    2009-09-30

    The adsorption process of chlorophenols (CPs) by low-cost adsorbents such as carbon blacks has been studied. The influence of different parameters such as temperature, pH, ionic strength and textural properties of the adsorbents on the adsorption process of pentachlorophenol has been analyzed. The adsorption process is exothermal and parameters such as pH and ionic strength exert a noticeable influence on the adsorption capacity of the solute. These parameters influence the adsorption capacity in an opposite manner. Thus an increase in pH seems to unfavor the adsorption process, whereas the adsorption capacity increases with increasing ionic strength. In order to analyze the influence of the number of chlorine atoms in the molecule of solute the adsorption process of different chlorophenols (i.e., 4-chlorophenol, 3,5-dichlorophenol, 2,4,6-trichlorophenol and 2,3,4,6-tetrachlorophenol) was analyzed. As the number of chlorine atoms (and thus the volume of the molecule) increases, the penetration of the solute through the porous texture of the adsorbent is difficult and, consequently, the adsorption capacity decreases. PMID:19403238

  1. Immobilized nickel hexacyanoferrate on activated carbons for efficient attenuation of radio toxic Cs(I) from aqueous solutions

    NASA Astrophysics Data System (ADS)

    Lalhmunsiama; Lalhriatpuia, C.; Tiwari, Diwakar; Lee, Seung-Mok

    2014-12-01

    The aim of this study is to immobilize nickel hexacyanoferrate onto the large surface of activated carbons (ACs) precursor to rice hulls and areca nut waste materials. These nickel hexacyanoferrate immobilized materials are then assessed in the effective attenuation of radio logically important cesium ions from aqueous solutions. The solid samples are characterized by the XRD analytical method and surface morphology is obtained from the SEM images. The batch reactor experiments show that an increase in sorptive pH (2.0-10.0) apparently not affecting the high percent uptake of Cs(I). Equilibrium modeling studies suggest that the data are reasonably and relatively fitted well to the Langmuir adsorption isotherm. Kinetic studies show that sorption process is fairly rapid and the kinetic data are fitted well to the pseudo-second order rate model. Increasing the background electrolyte concentration from 0.001 to 0.1 mol/L NaCl causes insignificant decrease in Cs(I) removal which infers the higher selectivity of these materials for Cs(I) from aqueous solutions. Further, the column reactor operations enable to obtain the breakthrough data which are then fitted to the Thomas non-linear equation as to obtain the loading capacity of column for Cs(I). The results show that the modified materials show potential applicability in the attenuation of radio toxic cesium from aqueous solution.

  2. Effects of solution chemistry on the removal reaction between calcium carbonate-based materials and Fe(II).

    PubMed

    Wang, Yu; Sikora, Saraya; Kim, Hwidong; Boyer, Treavor H; Bonzongo, Jean-Claude; Townsend, Timothy G

    2013-01-15

    Elevated iron concentrations have been observed in the groundwater underlying and surrounding several Florida landfill sites. An in situ groundwater remediation method for iron (present as soluble ferrous iron) using a permeable reactive barrier composed of calcium carbonate-based materials (CCBMs), such as limestone, was examined as a potentially effective and low-cost treatment technique. The effects of various environmental factors (i.e., pH, co-existing cations, and natural organic matter (NOM)) on the removal reaction were investigated using laboratory batch studies. Solution pH had a minor effect on iron removal, with superior iron removal observed in the highest pH solution (pH of 9). Sodium and calcium tended to impede the iron removal process by increasing the ionic strength of the solution. Manganese competes with iron ions at the adsorption sites on CCBMs; therefore, the presence of manganese prohibits iron removal and reduces removal effectiveness. NOM was found to decrease Fe(II) uptake by CCBMs and reduce the removal effectiveness by complexing Fe(II), most likely through the carboxyl group, thereby maintaining Fe(II) mobility in the aqueous phase. PMID:23228717

  3. Removal of hexavalent chromium in carbonic acid solution by oxidizing slag discharged from steelmaking process in electric arc furnace

    NASA Astrophysics Data System (ADS)

    Yokoyama, Seiji; Okazaki, Kohei; Sasano, Junji; Izaki, Masanobu

    2014-02-01

    Hexavalent chromium (Cr(VI)) is well-known to be a strong oxidizer, and is recognized as a carcinogen. Therefore, it is regulated for drinking water, soil, groundwater and sea by the environmental quality standards all over the world. In this study, it was attempted to remove Cr(VI) ion in a carbonic acid solution by the oxidizing slag that was discharged from the normal steelmaking process in an electric arc furnace. After the addition of the slag into the aqueous solution contained Cr(VI) ion, concentrations of Cr(VI) ion and total chromium (Cr(VI) + trivalent chromium (Cr(III)) ions decreased to lower detection limit of them. Therefore, the used slag could reduce Cr(VI) and fix Cr(III) ion on the slag. While Cr(VI) ion existed in the solution, iron did not dissolve from the slag. From the relation between predicted dissolution amount of iron(II) ion and amount of decrease in Cr(VI) ion, the Cr(VI) ion did not react with iron(II) ion dissolved from the slag. Therefore, Cr(VI) ion was removed by the reductive reaction between Cr(VI) ion and the iron(II) oxide (FeO) in the slag. This reaction progressed on the newly appeared surface of iron(II) oxide due to the dissolution of phase composed of calcium etc., which existed around iron(II) oxide grain in the slag.

  4. Controlling the optimum surfactants concentrations for dispersing carbon nanofibers in aqueous solution

    NASA Astrophysics Data System (ADS)

    Wang, Bao-Min; Yuan, Zhang; Guo, Zhi-Qiang; Ma, Hai-Nan; Lai, Chuan Fook

    2013-12-01

    As a new nano-scale functional material, it is necessary to achieve a uniform distribution in the composites for gaining the CNFs' excellent reinforcing effect. In this paper, CNFs were purified by the method of high temperature annealing treatment. Six surfactants, methylcellulose (MC), hydroxypropyl methylcellulose (HPMC), sodium dodecyl sulfate (SDS), dodecylamine (DDA), N, N-dimethyl formamide (DMF) and cetyltrimethyl ammonium bromide (CTAB) were used individually and combinatorially in a certain concentration to disperse the CNFs in aqueous solution. To achieve a good dispersion of the CNFs, a method utilizing ultrasonic processing was employed. The CNFs treated by the method of high temperature annealing treatment were characterized by differential thermal analysis (DTA) and thermogravimetry analysis (TGA), and the ultrasonication-driven dispersion of CNFs in aqueous solutions were monitored by UVvis spectroscopy and transmission electron microscopy (TEM). The experiments reveal that the method of high temperature annealing treatment purified the CNFs and the maximum achievable dispersion of CNFs corresponds to the maximum UV absorbance of the solution. All results show that the surfactants mixture of MC and SDS in a certain concentration of 0.4 and 2.0 g/L has the maximum dispersion effect on CNFs in aqueous solution, the optimum concentration ratio of MC, SDS, and CNFs was 2: 10: 1.

  5. Hand washing frequencies and procedures used in retail food services.

    PubMed

    Strohbehn, Catherine; Sneed, Jeannie; Paez, Paola; Meyer, Janell

    2008-08-01

    Transmission of viruses, bacteria, and parasites to food by way of improperly washed hands is a major contributing factor in the spread of foodborne illnesses. Field observers have assessed compliance with hand washing regulations, yet few studies have included consideration of frequency and methods used by sectors of the food service industry or have included benchmarks for hand washing. Five 3-h observation periods of employee (n = 80) hand washing behaviors during menu production, service, and cleaning were conducted in 16 food service operations for a total of 240 h of direct observation. Four operations from each of four sectors of the retail food service industry participated in the study: assisted living for the elderly, childcare, restaurants, and schools. A validated observation form, based on 2005 Food Code guidelines, was used by two trained researchers. Researchers noted when hands should have been washed, when hands were washed, and how hands were washed. Overall compliance with Food Code recommendations for frequency during production, service, and cleaning phases ranged from 5% in restaurants to 33% in assisted living facilities. Procedural compliance rates also were low. Proposed benchmarks for the number of times hand washing should occur by each employee for each sector of food service during each phase of operation are seven times per hour for assisted living, nine times per hour for childcare, 29 times per hour for restaurants, and 11 times per hour for schools. These benchmarks are high, especially for restaurant employees. Implementation would mean lost productivity and potential for dermatitis; thus, active managerial control over work assignments is needed. These benchmarks can be used for training and to guide employee hand washing behaviors. PMID:18724759

  6. Sonophotocatalytic degradation of methyl orange by carbon nanotube/TiO2 in aqueous solutions.

    PubMed

    Wang, Shuo; Gong, Qianming; Liang, Ji

    2009-02-01

    In this study, carbon nanotubes (CNTs)/TiO2 composite were prepared and the sonophotocatalytic activity of CNTs/TiO2 nanoparticles was investigated, in which methyl orange (MO) was chosen as an object. The results indicate that the photocatalytic efficiency of CNTs/TiO2 remarkable increases in the presence of ultrasound, and the sonophotocatalysis process followed a first-order kinetics. The kinetic constant of CNTs/TiO2 for the MO degradation is 2.2 times higher than that of P25, which indicated that the sonophotocatalytic ability of CNTs/TiO2 is obviously higher than P25 powder. PMID:18799343

  7. Carbon-modified electrode for ultra trace determination of Cd (II) in aqueous solution

    NASA Astrophysics Data System (ADS)

    Almustapha, Sakinatu; Khan, Aamir Amanat Ali; Omar, Abdul Aziz; Ariwahjoedi, Bambang; Abdullah, Mohd Azmuddin

    2014-10-01

    Increasing contamination of water by trace levels of heavy metals has become major environmental threats leading to an increased demand for the detection and monitoring of metal contaminants. In this work, modification of carbon electrode for Cd2+ detection using square wave anodic stripping voltammetry was reported. The deposition potential of -1.0 V in 0.1M acetate buffer for 240 sec, followed by square wave potential scan from -1.0 to -0.2 V were used. Stripping voltammogram showed current peaks corresponding to Cd2+. The sensitivity and selectivity of the modified electrodes for Cd2+ were also determined.

  8. Experimental study of the constituents of space wash water

    NASA Technical Reports Server (NTRS)

    Putnam, D. F.; Colombo, G. V.

    1975-01-01

    This report presents experimental data, obtained under controlled conditions, which quantify the various constituents of human origin that may be expected in space wash water. The experiments were conducted with a simulated crew of two male and two female subjects. The data show that the expected wash water contaminants originating from human secretions are substantially lower than theoretical projections indicated. The data presented are immediately useful and may have considerable impact on the tradeoff comparisons among various unit processes and systems under consideration by NASA for recycling space wash water.

  9. Detection of inhibitors in chicken tracheal washings against Mycoplasma gallisepticum.

    PubMed

    Slavik, M F; Maruca, S D; Skeeles, J K

    1982-01-01

    A chicken tracheal ring tissue-culture system was used to demonstrate that specific and nonspecific substances in chicken tracheal secretions inhibit the cilia-stopping effect (CSE) of Mycoplasma gallisepticum (MG). In chickens less than six weeks old, specific inhibitory substances were found in tracheal washings from chickens inoculated with MG. Nonspecific inhibitory substances were found in tracheal washes from untreated chickens seven weeks or older. Complement may play a role in the inhibition of CSE. Secretory immunoglobulin A was not detected in the tracheal washes. PMID:7092736

  10. 33 CFR 157.114 - Crude Oil Washing Operations and Equipment Manual: Not approved.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Crude Oil Washing Operations and Equipment...TANK VESSELS CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels General § 157.114 Crude Oil Washing Operations and...

  11. 33 CFR 157.112 - Approved Crude Oil Washing Operations and Equipment Manual.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Approved Crude Oil Washing Operations and Equipment...TANK VESSELS CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels General § 157.112 Approved Crude Oil Washing Operations and...

  12. 40 CFR 446.10 - Applicability; description of the oil-base solvent wash paint subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Applicability; description of the oil-base solvent wash paint subcategory. 446...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Paint Subcategory § 446.10 Applicability; description of the oil-base solvent wash paint subcategory....

  13. 40 CFR 446.10 - Applicability; description of the oil-base solvent wash paint subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Applicability; description of the oil-base solvent wash paint subcategory. 446...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Paint Subcategory § 446.10 Applicability; description of the oil-base solvent wash paint subcategory....

  14. 40 CFR 447.10 - Applicability; description of the oil-base solvent wash ink subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Applicability; description of the oil-base solvent wash ink subcategory. 447...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Ink Subcategory § 447.10 Applicability; description of the oil-base solvent wash ink subcategory....

  15. 40 CFR 447.10 - Applicability; description of the oil-base solvent wash ink subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Applicability; description of the oil-base solvent wash ink subcategory. 447...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Ink Subcategory § 447.10 Applicability; description of the oil-base solvent wash ink subcategory....

  16. 40 CFR 447.10 - Applicability; description of the oil-base solvent wash ink subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Applicability; description of the oil-base solvent wash ink subcategory. 447...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Ink Subcategory § 447.10 Applicability; description of the oil-base solvent wash ink subcategory....

  17. 40 CFR 446.10 - Applicability; description of the oil-base solvent wash paint subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Applicability; description of the oil-base solvent wash paint subcategory. 446...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Paint Subcategory § 446.10 Applicability; description of the oil-base solvent wash paint subcategory....

  18. 40 CFR 446.10 - Applicability; description of the oil-base solvent wash paint subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Applicability; description of the oil-base solvent wash paint subcategory. 446...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Paint Subcategory § 446.10 Applicability; description of the oil-base solvent wash paint subcategory....

  19. 40 CFR 446.10 - Applicability; description of the oil-base solvent wash paint subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Applicability; description of the oil-base solvent wash paint subcategory. 446...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Paint Subcategory § 446.10 Applicability; description of the oil-base solvent wash paint subcategory....

  20. 40 CFR 447.10 - Applicability; description of the oil-base solvent wash ink subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Applicability; description of the oil-base solvent wash ink subcategory. 447...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Ink Subcategory § 447.10 Applicability; description of the oil-base solvent wash ink subcategory....

  1. 40 CFR 447.10 - Applicability; description of the oil-base solvent wash ink subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Applicability; description of the oil-base solvent wash ink subcategory. 447...FORMULATING POINT SOURCE CATEGORY Oil-Base Solvent Wash Ink Subcategory § 447.10 Applicability; description of the oil-base solvent wash ink subcategory....

  2. The inhibiting action of intrinsic impurities in natural calcium carbonate minerals to their dissolution kinetics in aqueous H 2O–CO 2 solutions

    Microsoft Academic Search

    Laurent Eisenlohr; Krassimira Meteva; Franci Gabrovšek; Wolfgang Dreybrodt

    1999-01-01

    We have measured the surface controlled dissolution rates of natural calcium carbonate minerals (limestone and marble) in H2O–CO2 solutions by using free drift batch experiments under closed system conditions with respect to CO2, at 10°C with an initial partial pressure of carbon dioxide of 5 · 10?2 atm. All experiments revealed reaction rates F, which can be described by the

  3. Evaluation of corrosion protection of carbon black filled fusion-bonded epoxy coatings on mild steel during exposure to a quiescent 3% NaCl solution

    Microsoft Academic Search

    Y. H. Wei; L. X. Zhang; W. Ke

    2007-01-01

    Carbon black (CB) was mixed with fusion-bonded epoxy (FBE) coatings to generate a series of formulations with 0.5–4% by weight of carbon black. The degradation of these FBE coatings on mild steel exposed to a quiescent 3% NaCl solution was monitored using electrochemical impedance spectroscopy (EIS). The experimental results showed that the electrochemical behaviour of coated systems changed dramatically when

  4. Adsorption removal of acid black 1 from aqueous solution using ordered mesoporous carbon

    NASA Astrophysics Data System (ADS)

    Peng, Xiaoming; Hu, Xijun; Fu, Dafang; Lam, Frank L. Y.

    2014-03-01

    A novel ordered mesoporous carbon CMK-3 and synthetic CMK-3 containing nitrogen functional groups by ammonia-treated were applied for acid black 1(AB1) dye adsorption. The ammonia-treated(chemical vapor deposition method) before and after CMK-3 were characterized by using a Micrometitics ASAP 2020 surface area analyzer (ASAP 2020), Fourier transform infrared spectrophotometer (FT-IR), X-ray Photoelectron Spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscope (SEM) and equilibrium studies. This result indicates that the prepared CMK-3 and modified CMK-3 were almost uniform, as rope-like domains and their uniform mesopore with diameter centered at 3.2 nm and 3.7 nm. The FIIR analysis depicted that the presence of a variety of new basic functional groups on the modified CMK-3 surface. Several effect variables of pH, dye concentration and temperature were studied. The pseudo second-order model showed the ?tter well to agree with the kinetic data. The experimental data were analyzed by the Langmuir and Freundlich models, with the latter found to closely the isotherm model. The adsorption kinetics was found to follow the pseudo-second-order kinetic model. The results show that CMK-3 using ammonia gas modified by thermal treatment system is an effective method to improvement capacity as it shows the highest adsorption capacity of AB1, as compared to the unmodified CMK-3 and the bamboo-based carbon, respectively.

  5. CORROSION TESTING OF CARBON STEEL IN OXALIC ACID CHEMICAL CLEANING SOLUTIONS

    SciTech Connect

    Wiersma, B.; Mickalonis, J.; Subramanian, K.; Ketusky, E.

    2011-10-14

    Radioactive liquid waste has been stored in underground carbon steel tanks for nearly 60 years at the Savannah River Site. The site is currently in the process of removing the waste from these tanks in order to place it into vitrified, stable state for longer term storage. The last stage in the removal sequence is a chemical cleaning step that breaks up and dissolves metal oxide solids that cannot be easily pumped out of the tank. Oxalic acid has been selected for this purpose because it is an effective chelating agent for the solids and is not as corrosive as other acids. Electrochemical and immersion studies were conducted to investigate the corrosion behavior of carbon steel in simulated chemical cleaning environments. The effects of temperature, agitation, and the presence of sludge solids in the oxalic acid on the corrosion rate and the likelihood of hydrogen evolution were determined. The testing showed that the corrosion rates decreased significantly in the presence of the sludge solids. Corrosion rates increased with agitation, however, the changes were less noticeable.

  6. Effects of climate change on the wash-off of volatile organic compounds from urban roads.

    PubMed

    Mahbub, Parvez; Goonetilleke, Ashantha; Ayoko, Godwin A; Egodawatta, Prasanna

    2011-09-01

    The predicted changes in rainfall characteristics due to climate change could adversely affect stormwater quality in highly urbanised coastal areas throughout the world. This in turn will exert a significant influence on the discharge of pollutants to estuarine and marine waters. Hence, an in-depth analysis of the effects of such changes on the wash-off of volatile organic compounds (VOCs) from urban roads in the Gold Coast region in Australia was undertaken. The rainfall characteristics were simulated using a rainfall simulator. Principal Component Analysis (PCA) and Multicriteria Decision tools such as PROMETHEE and GAIA were employed to understand the VOC wash-off under climate change. It was found that low, low to moderate and high rain events due to climate change will affect the wash-off of toluene, ethylbenzene, meta-xylene, para-xylene and ortho-xylene from urban roads in Gold Coast. Total organic carbon (TOC) was identified as predominant carrier of toluene, meta-xylene and para-xylene in <1 ?m to 150 ?m fractions and for ethylbenzene in 150 ?m to >300 ?m fractions under such dominant rain events due to climate change. However, ortho-xylene did not show such affinity towards either TOC or TSS (total suspended solids) under the simulated climatic conditions. PMID:21737120

  7. Kinetics of absorption of carbon dioxide into aqueous solution of 2-(1-piperazinyl)-ethylamine

    Microsoft Academic Search

    Subham Paul; Aloke K. Ghoshal; Bishnupada Mandal

    2009-01-01

    The absorption of CO2 into aqueous solution of 2-(1-piperazinyl)-ethylamine (PZEA) were studied at 303, 313, and 323K within the amine concentration range of 0.083–1.226kmolm?3 using a wetted wall column absorber. The experimental results were used to interpret the kinetics of the reaction of CO2 with PZEA within the amine concentration range of 0.150–1.226kmolm?3 for the above mentioned temperature range. Based

  8. Kinetics of absorption of carbon dioxide into solutions of N-methyldiethanolamine+water

    Microsoft Academic Search

    Jiun-Jie Ko; Meng-Hui Li

    2000-01-01

    Kinetics of the absorption of CO2 into N-methyldiethanolamine (MDEA)+water were investigated at 30, 35, and 40°C using a laboratory wetted wall column. Four systems of which 1.0, 1.5, 2.0, and 2.5kmolm?3 MDEA aqueous solutions were studied. The solubility and the diffusivity of N2O in amine systems were also studied. The N2O analogy was applied to estimate the solubility and the

  9. Kinetics of Carbon Dioxide Absorption into Aqueous Solution of a Polyamine

    Microsoft Academic Search

    I. Siminiceanu; R. E. Tataru-Farmus; C. Bouallou

    The absorption of CO2 into an aqueous solution with 1.45 mol\\/L 1, 5, 8, 12- tetraazadodecane (APEDA) polyamine has been studied at three temperature (298, 313, 333 K) in a Lewis type absorber with a constant gas- liquid interface area of (15.34 0.05) x 10 ± -4 m 2 . The experimental results have been interpreted using the equations derived

  10. Chemical Absorption of Carbon Dioxide into Aqueous Colloidal Silica Solution with Diethanolamine

    Microsoft Academic Search

    2006-01-01

    The chemical absorption rate (RA) of CO2 was measured into the aqueous nanometer sized colloidal silica solution of 0–31 wt% and diethanoleamine of 0–2 kmol\\/m in the flat?stirred vessel with the impeller size of 0.034 m and its agitation speed of 50 rev\\/min at 25°C and 0.101 MPa, and compared with the values estimated from the model based on the film theory accompanied by chemical

  11. Removal of black carbon particles from experimental flue gas by surfactant solution in a new type of umbrella plate scrubber.

    PubMed

    Lu, Pei; Li, Caiting; Zeng, Guangming; Zhao, Yapei; Zhan, Qi; Song, Jingke; Fan, Xiaopeng

    2013-01-01

    Black carbon (BC) particles were removed from experimental flue gas by the surfactant solutions of sodium dodecylbenzene sulfonate (SDBS), hexadecyl trimethyl ammonium bromide (CTAB), fatty alcohol polyoxyethylene ether-9 (AEO-9) and polyoxy ethrlene nonyl phinyl ether-10 (TX-10), as well as AEO-9-SDBS, AEO-9-CTAB and SDBS-CTAB, in a new type of umbrella plate scrubber. Among the four independent surfactants, AEO-9 has the lowest surface tension, 35.9 mN/m, which resulted in the highest BC removal ratio among the alone surfactants. The experimental conditions were as follows: dust concentration = 3000 mg/m3; gas velocity = 14 m/s; liquid-gas ratio = 0.80 l/m3; and gas flow = 400 m3/h. When the mole ratio of the mixed surfactants was 1:1, the lowest surface tension could be detected among the studied mixed surfactants. According to the molecular interaction parameters (beta) and the mole ratio of surfactant 1 in the mixture (x1), the synergistic effects of AEO-9-SDBS and SDBS-CTAB solutions were obviously higher than those of AEO-9-TX-10 and AEO-9-CTAB. Therefore, AEO-9-SDBS solution had the lowest surface tension among the mixtures due to its beta < 0 and x1 = 0.85. The mixture solution of AEO-9-SDBS (1:1 mole ratio, 0.2 mmol/l) yielded the highest BC removal ratio, about 99.8%, and it was about 12% higher than that of only water, which was about 87.9%. The calculated critical micelle concentration was almost the same as that of the experimental concentration when the related equation was corrected by beta. PMID:23530320

  12. Cross contamination of Escherichia coli O157:H7 between lettuce and wash water during home-scale washing.

    PubMed

    Jensen, Dane A; Friedrich, Loretta M; Harris, Linda J; Danyluk, Michelle D; Schaffner, Donald W

    2015-04-01

    Lettuce and leafy greens have been implicated in multiple foodborne disease outbreaks. This study quantifies cross contamination between lettuce pieces in a small-scale home environment. A five-strain cocktail of relevant Escherichia coli O157:H7 strains was used. Bacterial transfer between single inoculated lettuce leaf pieces to 10 non-inoculated lettuce leaf pieces that were washed in a stainless steel bowl of water for 30 s, 1 min, 2 min, and 5 min was quantified. Regardless of washing time, the wash water became contaminated with 90-99% of bacteria originally present on the inoculated lettuce leaf piece. The E. coli O157:H7 concentration on initially inoculated leaf pieces was reduced ? 2 log CFU. Each initially uncontaminated lettuce leaf piece had ? 1% of the E. coli O157:H7 from the inoculated lettuce piece transferred to it after washing, with more transfer occurring during the shortest (30 s) and longest (5 min) wash times. In all cases the log percent transfer rates were essentially normally distributed. In all scenarios, most of the E. coli O157:H7 (90-99%) transferred from the inoculated lettuce pieces to the wash water. Washing with plain tap water reduces levels of E. coli O157:H7 on the inoculated lettuce leaf pieces, but also spreads contamination to previously uncontaminated leaf pieces. PMID:25475312

  13. POTENTIAL FOR STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS CONTAINING HIGHLY CAUSTIC SOLUTIONS

    SciTech Connect

    Lam, P.; Stripling, C.; Fisher, D.; Elder, J.

    2010-04-26

    The evaporator recycle streams of nuclear waste tanks may contain waste in a chemistry and temperature regime that exceeds the current corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history found that two of these A537 carbon steel tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved tanks of similar construction. Therefore, it appears that the efficacy of stress relief of welding residual stress is the primary corrosion-limiting mechanism. The objective of this experimental program is to test A537 carbon steel small scale welded U-bend specimens and large welded plates (30.48 x 30.38 x 2.54 cm) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 C). These conditions simulate worst-case situations in these nuclear waste tanks. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test was completed after 12 weeks of immersion in a similar solution at 125 C except that the aluminate concentration was reduced to 0.3 M. Visual inspection of the plate revealed that stress corrosion cracking had not initiated from the machined crack tips in the weld or in the heat affected zone. NDE ultrasonic testing also confirmed subsurface cracking did not occur. Based on these results, it can be concluded that the environmental condition of these tests was unable to develop stress corrosion cracking within the test periods for the small welded U-bends and for the large plates, which were welded with an identical procedure as used in the construction of the actual nuclear waste tanks in the 1960s. The absence of evidence of stress corrosion cracking and general corrosion in the laboratory-scaled specimens indicate that this type of nuclear waste tank is not susceptible to highly caustic solutions up to 12 M hydroxide at 125 C when sufficient nitrite inhibitor is present.

  14. Superhydrophobic and conductive properties of carbon nanotubes/polybenzoxazine nanocomposites coated ramie fabric prepared by solution-immersion process

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Yan, Hongqiang; Fang, Zhengping; E, Yuping; Wu, Tao; Chen, Fei

    2014-08-01

    Nanocomposites coating consisting of pristine multiwall carbon nanotubes (MWNTs) and polybenzoxazine has been constructed onto ramie fabric through solution-immersion process. The adsorbed nanocomposites coating is a hierarchical three-dimensional interpenetrating network structure, and the surface coverage and density increase substantially with increasing repeated immersing cycles. Measurements of the superhydrophobicity and conductivity for the coated ramie fabrics show that the highest water contact angle reaches 152°, the lowest water sliding angle reaches 3°, and the corresponding sheet resistance is 3410 ? sq-1, which shows strong dependency on the number of repeated immersing cycles and concentration of MWNTs suspension. This work provides a facile pathway to design and fabricate nanocomposites coated natural cellulosic fabric for superhydrophobic and conductive applications.

  15. Comparisons of kinetics, thermodynamics and regeneration of tetramethylammonium hydroxide adsorption in aqueous solution with graphene oxide, zeolite and activated carbon

    NASA Astrophysics Data System (ADS)

    Chang, Shenteng; Lu, Chungsying; Lin, Kun-Yi Andrew

    2015-01-01

    Graphene oxide (GO), sodium Y-type zeolite (NaY) and granular activated carbon (GAC) are selected as adsorbents to study their kinetics, thermodynamics and regeneration of tetramethylammonium hydroxide (TMAH) adsorption from water. The adsorption kinetics follows the pseudo-second-order rate law while the adsorption thermodynamics shows an exothermic reaction with GO and GAC but displays an endothermic reaction with NaY. The adsorbed TMAH can be readily desorbed from the surface of GO and NaY by 0.05 M NaCl solution. A comparative study on the cyclic TMAH adsorption with GO, NaY and GAC is also conducted and the results reveal that GO exhibits the greatest TMAH adsorption capacity as well as superior reversibility of TMAH adsorption over 10 cycles of adsorption and desorption process. These features indicate that GO is a promising and efficient adsorbent for TMAH removal in wastewater treatment.

  16. Impact of pressure, salt concentration, and temperature on the convective dissolution of carbon dioxide in aqueous solutions.

    PubMed

    Loodts, V; Rongy, L; De Wit, A

    2014-12-01

    The convective dissolution of carbon dioxide (CO2) in salted water is theoretically studied to determine how parameters such as CO2 pressure, salt concentration, and temperature impact the short-time characteristics of the buoyancy-driven instability. On the basis of a parameter-free dimensionless model, we perform a linear stability analysis of the time-dependent concentration profiles of CO2 diffusing into the aqueous solution. We explicit the procedure to transform the predicted dimensionless growth rate and wavelength of the convective pattern into dimensional ones for typical laboratory-scale experiments in conditions close to room temperature and atmospheric pressure. This allows to investigate the implicit influence of the experimental parameters on the characteristic length and time scales of the instability. We predict that increasing CO2 pressure, or decreasing salt concentration or temperature destabilizes the system with regard to convection, leading to a faster dissolution of CO2 into salted water. PMID:25554040

  17. Femtosecond laser-induced size reduction of carbon nanodots in solution: Effect of laser fluence, spot size, and irradiation time

    NASA Astrophysics Data System (ADS)

    Nguyen, Vanthan; Yan, Lihe; Si, Jinhai; Hou, Xun

    2015-02-01

    Photoluminescent carbon nanodots (C-dots) with size tunability and uniformity were fabricated in polyethylene glycol (PEG200N) solution using femtosecond laser ablation method. The size distributions and photoluminescence (PL) properties of C-dots are well controlled by adjusting the combined parameters of laser fluence, spot size, and irradiation time. The size reduction efficiency of the C-dots progressively increases with decreasing laser fluence and spot size. The optimal PL spectra are red-shifted and the quantum yields decrease with the increase in C-dots size, which could be attributed to the more complex surface functional groups attached on C-dots induced at higher laser fluence and larger spot size. Moreover, an increase in irradiation time leads to a decrease in size of C-dots, but long-time irradiation will result in the generation of complex functional groups on C-dots, subsequently the PL spectra are red-shifted.

  18. In situ synthesis of carbon nanotubes decorated with palladium nanoparticles using arc-discharge in solution method

    SciTech Connect

    Bera, Debasis; Kuiry, Suresh C.; McCutchen, Matthew; Seal, Sudipta; Heinrich, Helge; Slane, Grady C. [Surface Engineering and Nanotechnology Facility (SNF), Advanced Materials Processing and Analysis Center (AMPAC), and Mechanical, Materials and Aerospace Engineering - MMAE, University of Central Florida, 4000 Central Florida Boulevard, Eng 1, no. 381, Orlando, Florida 32816 (United States); Advanced Materials Processing and Analysis Center (AMPAC), and Department of Physics, University of Central Florida, 4000 Central Florida Boulevard, Eng 1, no. 381, Orlando, Florida 32816 (United States); Lake Highland Preparatory School, 901 North Highland Avenue, Orlando, Florida 32803 (United States)

    2004-11-01

    A unique, simple, inexpensive, and one-step synthesis route to produce carbon nanotubes (CNTs) decorated with palladium nanoparticles using a simplified dc arc-discharge in solution is reported. Zero-loss energy filtered transmission electron microscopy and scanning transmission electron microscopy confirm the presence of 3 nm palladium nanoparticles. Such palladium nanoparticles form during the reduction of palladium tetra-chloro-square-planar complex. The deconvoluted x-ray photoelectron spectroscopy envelope shows the presence of palladium on the decorated CNTs. The energy dispersive spectroscopy suggests no functionalization of atomic chlorine to the sidewall of the CNTs. The presence of dislodged graphene sheets with wavy morphology supports the formation of CNTs through the 'scroll mechanism'.

  19. Hyperfiltration wash water recovery subsystem - Design and test results. [for extended mission spacecraft such as space stations

    NASA Technical Reports Server (NTRS)

    Reysa, R. P.; Price, D. F.; Olcott, T.; Gaddis, J. L.

    1983-01-01

    The Hyperfiltration Wash Water Recovery (HWWR) subsystem, designed to offer low-power high-volume wash water purification for extended mission spacecraft, is discussed in terms of preprototype design and configuration. Heated wash water collected from the shower, hand wash, and laundry flows into a temperature-controlled (374 K) waste storage tank. Two parallel 25 micron absolute filters at the tank outlet remove large particles from the feed stream. A positive displacement feed pump delivers wash water to the hyperfiltration module at a constant flow rate of 0.20 lpm with discharge pressure variations from 4181-7239 Kpa. The hyperfiltration membrane module is a single-pass design including 36 porous stainless steel tubes, and is designed to provide an approximate water recovery rate of 90 percent. Permeate and brine water flows are monitored by flow meters, and removal of urea and ammonia is achieved by adding 15 percent NaOCl solution to the permeate fluid stream. An alternate module design using two diameters of tubing (allowing a smaller pressure drop and a larger membrane area) gave a superior predicted performance over the first module with larger tubing throughout.

  20. Effects of solution chemistry on adsorption of selected pharmaceuticals and personal care products (PPCPs) by graphenes and carbon nanotubes.

    PubMed

    Liu, Fei-fei; Zhao, Jian; Wang, Shuguang; Du, Peng; Xing, Baoshan

    2014-11-18

    Adsorption of three selected pharmaceuticals and personal care products (PPCPs) (ketoprofen (KEP), carbamazepine (CBZ), and bisphenol A (BPA)) by two reduced graphene oxides (rGO1 and rGO2) and one commercial graphene was examined under different solution conditions. Single-walled carbon nanotubes (SWCNTs), multiwalled carbon nanotubes (MWCNTs), and powdered graphite were also investigated for comparison. All adsorption isotherms followed the order of SWCNTs > rGO1 > rGO2 > MWCNTs > graphene > graphite, consistent with the orders of their surface areas and micropore volumes. After surface area normalization, adsorption affinities of the three PPCPs onto graphenes were lower than onto graphite, suggesting incomplete occupation for adsorption sites because of the aggregation of graphene sheets and the presence of oxygen-containing functional groups. The observed pH effects on adsorption correlated well with the pH-regulated distribution of the protonated neutral species of the three PPCPs. Increasing ionic strength from 0 to 20 mM increased KEP adsorption due to the electrostatic screening by Na(+) and Ca(2+). Both humic acid (HA) and sodium dodecylbenzenesulfonate (SDBS) suppressed PPCPs adsorption to all adsorbents, but their impacts onto graphenes were lower than those onto CNTs because of their lower adsorption by graphenes. More severe HA (or SDBS) effect was found on negatively charged KEP at the tested solution pH 6.50 due to the electrostatic repulsion between the same charged KEP and HA (or SDBS). The findings of the present study may have significant implications for the environmental fate assessment of PPCPs and graphene. PMID:25353977