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1

Plutonium recovery from carbonate wash solutions  

SciTech Connect

Periodically higher than expected levels of plutonium are found in carbonate solutions used to wash second plutonium cycle solvent. The recent accumulation of plutonium in carbonate wash solutions has led to studies to determine the cause of that plutonium accumulation, to evaluate the quality of all canyon solvents, and to develop additional criteria needed to establish when solvent quality is acceptable. Solvent from three canyon solvent extraction cycles was used to evaluate technology required to measure tributyl phosphate (TBP) degradation products and was used to evaluate solvent quality criteria during the development of plutonium recovery processes. 1 fig.

Gray, J.H.; Reif, D.J.; Chostner, D.F.; Holcomb, H.P.

1991-12-31

2

Solvent wash solution  

DOEpatents

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.

Neace, J.C.

1984-03-13

3

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

PubMed

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

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

2014-07-01

4

Soil washing of fluorine contaminated soil using various washing solutions.  

PubMed

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

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

2015-03-01

5

Recovery of plutonium from solvent wash solutions  

SciTech Connect

A number of potential alternatives to the acid hydrolysis recovery of Pu were investigated. The most promising alternative for short-term use appears to be an anion exchange process that would eliminate the long boiling times and the multiple-pass concentration steps needed with the solvent extraction process because it separates the Pu from the dibutyl phosphate (DBP) while at the same time concentrating the Pu. However, restart of the Primary Recovery Column (PRC) to process this solution would require significant administrative effort. The original boiling recovery by acid hydrolysis followed by solvent extraction is probably the most expedient way to process the Pu-DBP-carbonate solution currently stored in tank 13.5 even with its long processing times and dilute product concentration. Anion exchange of a heat stabilized acidified solution is a more efficient process, but requires restart of the PRC. Extended-boiling acid hydrolysis or anion exchange of a heat stabilized acidified solution provide two well developed alternatives for recovery of the Pu from the tank 13.5 carbonate. Further work defining additional recovery processes is not planned at this time.

Kyser, E.A.

1992-03-31

6

Synergetic effect of a novel wash aid, T-128, in improving chlorine efficacy against bacterial pathogens in wash solution containing high organic loads  

Technology Transfer Automated Retrieval System (TEKTRAN)

Chlorine is widely used as a sanitizer in commercial fresh-cut wash water for produce processing of bagged leafy greens. However, free chlorine depletion occurs rapidly when high organic content loads are introduced directly into the wash solution as part of the washing operation process. This chl...

7

Sludge washing materials study: The materials performance behavior of carbon steel in a dilute waste environment  

SciTech Connect

For sludge washing to be conducted in existing Hanford carbon steel tanks, there must be an assurance that the tanks will be safe from failure by pitting, stress-corrosion cracking (SCC) or other failure processes when the corrosion inhibitors present in the waste are diluted during the sludge washing operation. Testing in the past has been concerned with defining the safe operating regimes in concentrated waste environments. The corrosion testing reported herein has been carried out to determine the safe chemical bounds in the dilute regime. Six month exposure coupon tests, slow strain rate tests, and potentiodynamic scans have been completed on a statistically designed test matrix of sixteen test solutions. Uniform corrosion rates (maximum of 0.15 mpy) were too low to be an important failure process. Incipient pitting in the vapor phase was commonly found, with a few deep pits propagating at a maximum rate of 40 mpy. Slow strain rate testing revealed SCC in solutions {number_sign}1 and {number_sign}2, only. These two solutions are low in hydroxide, with nitrate/nitrite ratios {>=}10. Crevice corrosion was also observed in these two solutions. The composition of solution {number_sign}1 falls into a chemical range in which the data base (Table 1) used for SCC prevention would have predicted SCC immunity. This may be an indication this data base, which is the technical basis for preventing SCC in concentrated environments, is incomplete at the lower concentrations.

Danielson, M.J.; Bunnell, L.R. [Pacific Northwest Lab., Richland, WA (United States)

1995-11-01

8

Effect of Nitric Acid ``Washing'' Procedure on Electrochemical Behavior of Carbon Nanotubes and Glassy Carbon ?-Particles  

NASA Astrophysics Data System (ADS)

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.

Anik, Ülkü; Çevik, Serdar; Pumera, Martin

2010-05-01

9

Process for purifying a sulfur dioxide containing gas by washing with an ammonia aqueous solution  

Microsoft Academic Search

Process for purifying a sulfur dioxide containing gas, by washing with an ammonia aqueous solution is comprised of the following steps: (a) contacting a sulfur dioxide containing gas with ammonia and\\/or ammonium sulfite in the presence of water, to form a solution containing ammonium bisulfite and\\/or sulfite; (b) reacting at least a portion of the solution obtained in step (a)

A. Deschamps; S. Franckowiak; P. Renault

1979-01-01

10

Changes in soil toxicity by phosphate-aided soil washing: Effect of soil characteristics, chemical forms of arsenic, and cations in washing solutions.  

PubMed

This study was set to investigate the changes in the toxicity of arsenic (As)-contaminated soils after washing with phosphate solutions. The soil samples collected from two locations (A: rice paddy and B: forest land) of a former smelter site were contaminated with a similar level of As. Soil washing (0.5M phosphate solution for 2h) removed 24.5% As, on average, in soil from both locations. Regardless of soil washing, Location A soil toxicities, determined using Microtox, were greater than that of Location B and this could be largely attributed to different soil particle size distribution. With soils from both locations, the changes in As chemical forms resulted in either similar or greater toxicities after washing. This emphasizes the importance of considering ecotoxicological aspects, which are likely to differ depending on soil particle size distribution and changes in As chemical forms, in addition to the total concentration based remedial goals, in producing ecotoxicologically-sound soils for reuse. In addition, calcium phosphate used as the washing solution seemed to contribute more on the toxic effects of the washed soils than potassium phosphate and ammonium phosphate. Therefore, it would be more appropriate to use potassium or ammonium phosphate than calcium phosphate for phosphate-aided soil washing of the As-contaminated soils. PMID:25482580

Jho, Eun Hea; Im, Jinwoo; Yang, Kyung; Kim, Young-Jin; Nam, Kyoungphile

2015-01-01

11

Efficacy of different washing solutions and contact times on the microbial quality and safety of fresh-cut paprika.  

PubMed

The role of different washing solutions and contact times was investigated to determine their use as potential sanitizers for maintaining the microbial quality and food safety of fresh-cut paprika. Samples were cut into small pieces, washed for both 90 and 180 s by different washing solutions: tap water, chlorinated water (100?mg/L and pH 6.5-7), electrolyzed water (pH 7.2) and ozonized water (4?mg/L). Then, samples were packaged in 50?µm polypropylene bags and stored at 5?°C for 12 days, followed by an evaluation of the antimicrobial efficacy of the treatments. Various quality and safety parameters, such as gas composition, color, off-odor, electrical conductivity and microbial numbers, were evaluated during storage. Results revealed insignificant differences in gas composition, and no off-odor was observed in any of the samples during the storage period. However, longer contact time resulted in slightly lower hue angle value than a short one for all washing solutions. Moreover, samples washed with ozone washings showed lower electrolyte leakage than other washing solutions. Samples washed for longer contact time except those washed in ozonized water showed increased microbial numbers during storage. Hence, it has been concluded that longer contact time with ozone has positive effects, whereas the other washing solutions adversely affect the microbial quality and safety aspects of fresh-cut paprika. PMID:21954309

Das, B Kumar; Kim, Ji Gang; Choi, Ji Weon

2011-10-01

12

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

NASA Astrophysics Data System (ADS)

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

Meredith, Austin Dean

13

Optimal operational conditions for the electrochemical regeneration of a soil washing EDTA solution.  

PubMed

The present research deals with the optimization of the operating parameters (cathode replacement time, hydraulic retention time, current intensity and pH) of an electrochemical process aimed at the regeneration of a soil washing EDTA solution used for heavy metal extraction from a natural contaminated soil (excavated from Bellolampo, Palermo, Italy), which was vastly polluted with Cu (59 261.0 mg kg(-1)), Pb (14 178.1 mg kg(-1)) and Zn (14 084.9 mg kg(-1)). The electrolytic regeneration of the exhausted washing solution was performed in a laboratory scale electrolytic cell with 50 ml each cathodic and anodic chambers divided by a cation exchange membrane. Experiments II and III showed maximum Cu and Zn removal efficiencies from the EDTA solution, of 99.2+/-0.2 and 31.5+/-9.3%, respectively, when a current intensity of 0.25 A and a hydraulic retention time of 60 min were applied to the electrolytic cell, while the maximum Pb removal efficiency of 70.9+/-4.6% was obtained with a current intensity of 1.25 A and a hydraulic retention time of 60 min. During Experiment I the overall heavy metals removal efficiency was stable and close to 90% up to 20 h, while decreased to values lower than 80% after 40 h, indicating the occurrence of a significant saturation of the cathode graphite bed between 20 and 40 h. The capability of the regenerated EDTA solution to treat heavy metals polluted soils was tested in further experiments applying both a single and a multi-step washing treatment procedure. In particular, the latter showed the feasibility to increase heavy metal soil extractions over subsequent washing steps with Cu, Pb and Zn total removal efficiencies of 52.6, 100.0 and 41.3%, respectively. PMID:19212586

Cesaro, Raffaele; Esposito, Giovanni

2009-02-01

14

Comparison between supercritical carbon dioxide extraction and aqueous surfactant washing of an oily machining waste.  

PubMed

Mathematical models are developed to compare aqueous surfactant washing to supercritical carbon dioxide (SCCO2) extraction. These two cleaning processes are potentially competitive technologies which can be used to remove oily contaminants from a solid waste. In both processes, the cleaning efficiency for a batch of waste is evaluated by quantifying the residual oil content in the treated sample. A mass transfer model is used to simulate a semi-continuous washing process, and the experimental data, obtained in a batch operation, are used to estimate the equilibrium parameters in the model. For SCCO2 extraction, a linear desorption model is used to describe the supercritical desorption of oil from the solid phase into the CO2 phase and the simulated results agreed very well with the experimental data. The oil removal in aqueous surfactant washing is viewed to be controlled primarily by the diffusional transport of oil from the interiors of the waste elements to the surface, thus, it can be significantly affected by the size of the particles. A pre-cleaning pulverization is then recommended to improve the cleaning efficiency without increasing any other operation costs. In SCCO2 extraction, the desorption of oil from the solid waste is the controlling step and consequently, the solvent flow rate has no influence on oil removal. Our theoretical studies show that the difference between the cleaning efficiencies of these two technologies is not significant, with the oil concentration in the washing products approximately 5% lower than that in the extraction products. PMID:10341302

Fu, H; Matthews, M A

1999-06-11

15

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

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

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

2012-01-01

16

Effect of exhaust emissions on carbon monoxide levels in employees working at indoor car wash facilities  

PubMed Central

Background: Exhaust emissions from motor vehicles threaten the environment and human health. Carbon monoxide (CO) poisoning, especially the use of exhaust gas CO in suicidal attempts is well known in the literature. Recently, indoor car wash facilities established in large shopping malls with closed parking, lots is a new risk area that exposes car wash employees to prolonged periods of high level CO emissions from cars. The aim of this study was to investigate how carboxyhemoglobin (COHb) blood levels of employees get affected in confined areas with relatively poor air circulation. Methods: Twenty male volunteers working in indoor parking car wash facilities were included in the study. Participants were informed about the aim of this study and their consent was obtained. Their pulse COHb levels were measured twice, at the beginning and at the end of the working day using Rad-57 pulse CO-oximeter device, allowing non-invasive measurement of COHb blood levels to compare the changes in their COHb levels before and after work. Results: The mean age of the male volunteers was 29.8 ± 11.9 (range 18-55). While the mean COHb levels measured at the start of the working day was 2.1 ± 2.0 (range 0-9), it was increased to 5.2 ± 3.3 (range 1-15) at the end of work shift (Wilcoxon test, p <0.001). There was a statistically significant difference in COHb levels between the beginning and the end of the work shift in smoker subjects, while the difference was not significant in the non-smoking group (Wilcoxon test, p=0.001, p=0.102, respectively). Conclusion: The COHb blood levels of indoor car wash facility employees is directly impacted and gets elevated by motor vechile exhaust emissions. For the health of the employees at indoor parking car wash facilities, stricter precautions are needed and the government should not give permit to such operations. PMID:25125950

Topacoglu, H; Katsakoglou, S; Ipekci, A

2014-01-01

17

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

PubMed

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

Ramadhan, Kurnia; Huda, Nurul; Ahmad, Ruzita

2014-02-01

18

Physicochemical and microbial quality of stored green slender pepper treated with different washing solutions and packaging films.  

PubMed

The effects of different washing solutions and packaging films on textural, biochemical and microbial quality of green slender peppers (Capsicum annuum L.) were evaluated. Fresh pepper samples were packaged either in 35?µm polypropylene or polyethylene bag without washing or after washing in tap water (TW), 100-ppm chlorine solution, 0.5% calcinated calcium solution followed by 25% ethanol rinsing (CC+E) and 1% citric acid solution followed by 50% ethanol spray (CA+E) and then stored at 10? for 4 weeks. Significant differences were found in gas composition between the two packaging films. Changes in skin puncture force, hue angle, soluble solid content, titratable acidity and pH were statistically insignificant. Chlorophyll a, chlorophyll b and total chlorophyll content declined significantly (P?washing treatments compared to unwashed sample except in TW. Yeast and mold count of chlorine and CC+E-treated samples were lower than other treatments. Samples of these two treatments also received marketable limit of visual quality scores until 4 weeks of storage in polypropylene film. Results suggest that CC+E could be a potential sanitizer and alternative to chlorine washing and polypropylene film would provide a little better advantage than polyethylene for green slender pepper. PMID:23733826

Chandra, Dulal; Kim, Ji Gang; Kim, Yong Phil

2014-03-01

19

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

PubMed

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

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

2014-12-15

20

Recovery of bacteria from broiler carcasses after spray washing with acidified electrolyzed water or sodium hypochlorite solutions.  

PubMed

A study was conducted to investigate the effects of spray washing broiler carcasses with acidified electrolyzed oxidizing water (EO) or sodium hypochlorite (HOCl) solutions for 5, 10, or 15 s. Commercial broiler carcasses were contaminated with 0.1 g of broiler cecal contents inoculated with 10(5) cells of Campylobacter and 10(5) cells of nalidixic acid-resistant Salmonella. Numbers of bacteria recovered from unwashed control carcasses were 6.7, 5.9, 6.3, and 3.9 log(10) cfu/mL for total aerobic bacteria, Escherichia coli, Campylobacter, and Salmonella, respectively. Washing in either EO (50 mg/L of sodium hypochlorite, pH 2.4, oxidation reduction potential of 1,180 mV) or HOCl (50 mg/L of sodium hypochlorite, pH 8.0) significantly reduced the levels of bacteria recovered from carcasses (P < 0.05). Carcasses washed with EO had slightly lower levels of total aerobic bacteria (0.3 log(10) cfu/mL) and E. coli (0.2 log(10) cfu/mL) than HOCl-treated carcasses; however, populations of Campylobacter and Salmonella were comparable after washing in either solution. Increasing the carcass washing time from 5 to 10 s lowered the levels of total aerobic bacteria (6.1 vs. 5.8 log(10) cfu/mL), E. coli (4.6 vs. 4.1 log(10) cfu/mL), Campylobacter (5.2 vs. 4.2 log(10) cfu/mL), and Salmonella (2.0 vs. 1.2 log(10) cfu/mL), but no further microbiological reductions occurred when washing time was extended from 10 to 15 s. Data from the present study show that washing poultry carcasses with EO is slightly better (total aerobic bacteria and E. coli) or equivalent to (Campylobacter and Salmonella) washing with HOCl. Washing broiler carcasses for a period equivalent to 2 inside-outside bird washers (10 s) provided greater reductions in carcass bacterial populations than periods simulating 1 (5 s) or 3 inside-outside bird washers (15 s). PMID:17878456

Northcutt, J; Smith, D; Ingram, K D; Hinton, A; Musgrove, M

2007-10-01

21

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

PubMed Central

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

Yeung, Norine W; Hayes, Kenneth A

2013-01-01

22

Hand Washing  

MedlinePLUS

... News Anxiety Disorders Relaxation Exercises The Flu Vaccine Hand Washing KidsHealth > Teens > Body > Skin Stuff > Hand Washing ... or from animals and animal waste. Continue Defensive Hand Washing In 2010 the American Society for Microbiology ...

23

Ketoconazole or clotrimazole solution wash as a prophylaxis in management and prevention of fungal infection: a comparative study.  

PubMed

The incidence of fungal infections has increased at an alarming rate in the past two decades. Topical Ketoconazole and Clotrimazole solutions are used to stop growth of fungus like Dermatophytes, Candidiasis and Pityrosporum. The objective of this study is to assess the effectiveness of prophylactic Ketoconazole or Clotrimazole solution wash in patients with fungal infections. Hundred patients (aged 10-60 yrs) with different fungal infections (Candida, Tinea, Pityriasis) were included. The study groups were divided into intervention group and control group. The Intervention group was given 5 weeks prophylactic Ketoconazole/Clotrimazole shampoo wash along with antifungal treatment whereas the control group was given only antifungal treatment without prophylaxis. All the patients were assessed at 1, 3 and 6 months interval to find out the response and recurrence. After one month of treatment 96% of patients in the intervention group and 60% of patients in the control group were completely cured. The recurrence rate after 3 mths of treatment was 4% in the intervention group and 40% in the control group. After 6 months the recurrence rate was 4% in the intervention group and 60% in the control group. The most common problem with fungal infections is the recurrence. Use of prophylactic antifungal (Ketoconazole/Clotrimazole) wash for some period of time along with antifungal treatment minimizes the chances of recurrence. PMID:24592790

Shrestha, S; Jha, A K; Pathak, D Thapa; Kharel, C Bhattarai; Basukala, S M

2013-03-01

24

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

PubMed

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

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

2005-04-01

25

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...

26

Washing of various lead compounds from a contaminated soil column  

SciTech Connect

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.

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

1998-11-01

27

Influence of particle size distribution, organic carbon, pH and chlorides on washing of mercury contaminated soil.  

PubMed

Feasibility of soil washing to remediate Hg contaminated soil was studied. Dry sieving was performed to evaluate Hg distribution in soil particle size fractions. The influence of dissolved organic matter and chlorides on Hg dissolution was assessed by batch leaching tests. Mercury mobilization in the pH range of 3-11 was studied by pH-static titration. Results showed infeasibility of physical separation via dry sieving, as the least contaminated fraction exceeded the Swedish generic guideline value for Hg in soils. Soluble Hg did not correlate with dissolved organic carbon in the water leachate. The highest Hg dissolution was achieved at pH 5 and 11, reaching up to 0.3% of the total Hg. The pH adjustment was therefore not sufficient for the Hg removal to acceptable levels. Chlorides did not facilitate Hg mobilization under acidic pH either. Mercury was firmly bound in the studied soil thus soil washing might be insufficient method to treat the studied soil. PMID:24873713

Xu, Jingying; Kleja, Dan B; Biester, Harald; Lagerkvist, Anders; Kumpiene, Jurate

2014-08-01

28

Effects of washing solution and drying condition on reactivity of nano-scale zero valent irons (nZVIs) synthesized by borohydride reduction.  

PubMed

Washing and drying processes are essential when synthesizing nano-scale zero valent irons (nZVIs) by borohydride reduction of iron salts in aqueous phase. However, effects of these processes on nZVI reactivity have not been investigated in detail, although different washing and drying conditions might alter surface characteristics of nZVIs and thus vary their reactivity towards reducible contaminants. In this study, effects of three washing solutions and drying conditions on the reactivity of nZVIs for nitrate were investigated. Washing with volatile solvents and drying under anaerobic condition decreased thickness of Fe-oxide layer on nZVIs and increased content of Fe(2+)-containing oxides in the layer, which enhanced nZVI reactivity toward nitrate. Volatile solvent washing could minimize the decrease in nZVI reactivity according to changing anaerobic drying condition to aerobic. Findings from this study suggest that application of washing with volatile solvents and drying under aerobic condition should be recommended as effective processes to obtain nZVIs with maximum reactivity at reasonable costs and efforts. PMID:24290304

Woo, Heesoo; Park, Junboum; Lee, Seockheon; Lee, Seunghak

2014-02-01

29

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...

30

Modeling of the effect of washing solution flow conditions on Escherichia coli O157:H7 population reduction on fruit surfaces.  

PubMed

Washing produce with sanitizing solutions is an important step in reducing microbial populations during postharvest handling. Little information exists regarding the effects of washing solution flow conditions on the efficacy of pathogen reduction during washing. This study was undertaken to investigate the effects of washing conditions such as flow velocity, agitation rate, and contact time on the reduction of Escherichia coli O157:H7 populations from the surfaces of cantaloupe rind and cut apples. Top surfaces of cylindrical samples were spot inoculated with E. coli O157:H7 and treated with peroxyacetic acid (POAA; 80 mg/liter) solution under different flow velocities and agitation rates and with different washing modes. Test results indicate that the reduction rate of E. coli O157:H7 increased with the increase in flow velocity and agitation rate under the testing conditions. In a 3-min treatment in the flow-through chamber, the E. coli O157:H7 count reduction on cantaloupe rind and cup apples reached 2.5 and 2.3 log CFU/cm2, respectively, when the flow velocity increased from 0.0 to 0.8 m/min. Agitation conducted at the bottom of the treatment chamber reduced the E. coli O157:H7 population on cut apples by 1.2 log CFU/cm2 in 3 min, whereas in the treatment with the agitation over the top of the chamber, the survival count of E. coli O157:H7 was reduced by only 0.8 log CFU/cm2. The experimental data were used to fit four microbial reduction kinetic models. It was found that E. coli O157:H7 reduction from the fruit surfaces was best described by the Weibull model. These findings may be useful in designing produce wash systems for achieving enhanced pathogen reduction and improved produce quality and safety. PMID:18044431

Wang, Hua; Liang, Wei; Feng, Hao; Luo, Yaguang

2007-11-01

31

Carbonation of municipal solid waste incineration electrostatic precipitator fly ashes in solution.  

PubMed

Carbonation was applied to a Pb- and Zn-contaminated fraction of municipal solid waste incineration electrofilter fly ashes in order to reduce heavy metal leaching. Carbonation tests were performed in solution, by Na2CO3 addition or CO2 bubbling, and were compared with washing (with water only). The injection of CO2 during the washing did not modify the mineralogy, but the addition of Na2CO3 induced the reaction with anhydrite, forming calcite. Microprobe analyses showed that Pb and Zn contamination was rather diffuse and that the various treatments had no effect on Pb and Zn speciation in the residues. The leaching tests indicated that carbonation using Na2CO3 was successful because it gave a residue that could be considered as non-hazardous material. With CO2 bubbling, Pb and Zn leaching was strongly decreased compared with material washed with water alone, but the amount of chromium extracted became higher than the non-hazardous waste limits for landfilling. PMID:24718362

De Boom, Aurore; Aubert, Jean-Emmanuel; Degrez, Marc

2014-05-01

32

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.

33

Washing off intensification of cotton and wool fabrics by ultrasounds.  

PubMed

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

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

2015-03-01

34

Treatment of distillery spent-wash by ozonation and biodegradation: significance of pH reduction and inorganic carbon removal before ozonation.  

PubMed

This study is aimed at exploring strategies for mineralization of refractory compounds in distillery effluent by anaerobic biodegradation/ozonation/aerobic biodegradation. Treatment of distillery spent-wash used in this research by anaerobic-aerobic biodegradation resulted in overall COD removal of 70.8%. Ozonation of the anaerobically treated distillery spent-wash was carried out as-is (phase I experiments) and after pH reduction and removal of inorganic carbon (phase II experiments). Introduction of the ozonation step resulted in an increase in overall chemical oxygen demand (COD) removal, with the highest COD removals of greater than 95% obtained when an ozone dose of approximately 5.3 mg ozone absorbed/mg initial total organic carbon was used. The COD removal during phase II experiments was slightly superior compared with phase I experiments at similar ozone doses. Moreover, efficiency of ozone absorption from the gas phase into distillery spent-wash aliquots was considerably enhanced during phase II experiments. PMID:17120459

Kumar, Arun; Saroj, Devendra P; Tare, Vinod; Bose, Purnendu

2006-09-01

35

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)

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.

Nipper, J.; Bowden, W. B.

2009-12-01

36

Aqueous solution dispersement of carbon nanotubes  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

37

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...

38

Wash Your Hands  

MedlinePLUS

... What's this? Submit Button CDC Features Wash Your Hands Language: English Español (Spanish) Share Compartir Keeping hands ... more about when and how to wash your hands. When should you wash your hands? Before , during, ...

39

The comparative photodegradation activities of pentachlorophenol (PCP) and polychlorinated biphenyls (PCBs) using UV alone and TiO2-derived photocatalysts in methanol soil washing solution.  

PubMed

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

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

2014-01-01

40

Continuous electrolytic decarbonation and recovery of a carbonate salt solution from a metal-contaminated carbonate solution.  

PubMed

This work studied the characteristic changes of a continuous electrolytic decarbonation and recovery of a carbonate salt solution from a metal-contaminated carbonate solution with changes of operational variables in an electrolytic system which consisted of a cell-stacked electrolyzer equipped with a cation exchange membrane and a gas absorber. The system could completely recover the carbonate salt solution from a uranyl carbonato complex solution in a continuous operation. The cathodic feed rate could control the carbonate concentration of the recovered solution and it affected the most transient pH drop phenomenon of a well type within the gas absorber before a steady state was reached, which caused the possibility of a CO(2) gas slip from the gas absorber. The pH drop problem could be overcome by temporarily increasing the OH(-) concentration of the cathodic solution flowing down within the gas absorber only during the time required for a steady state to be obtained in the case without the addition of outside NaOH. An overshooting peak of the carbonate concentration in the recovered solution before a steady state was observed, which was ascribed to the decarbonation of the initial solution filled within the stacked cells by a redundant current leftover from the complete decarbonation of the feeding carbonate solution. PMID:19604641

Kim, Kwang-Wook; Kim, Yeon-Hwa; Lee, Se-Yoon; Lee, Eil-Hee; Song, Kyusuk; Song, Kee-Chan

2009-11-15

41

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

NASA Astrophysics Data System (ADS)

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.

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

1994-05-01

42

Dissolution of Spent Nuclear Fuel in Carbonate-Peroxide Solution  

SciTech Connect

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.

Soderquist, Chuck Z.; Hanson, Brady D.

2010-01-31

43

ABSORPTION OF CARBON DIOXIDE INTO AQUEOUS DIETHANOLAMINE SOLUTIONS  

Microsoft Academic Search

The rates of absorption of pure carbon dioxide into aqueous diethanolamine solutions were measured at 25C in a liquid-jet column and a wetted-wall column. Experimental results were analyzed with the chemical absorption theory based on the penetration model. Physical solubility of carbon dioxide in aqueous diethanolamine solutions was determined from the absorption rates measured in a near pseudo first-order reaction

H. HIKITA; S. ASAI; H. ISHIKAWA; K. UKU

1980-01-01

44

Optimization of anaerobically digested distillery molasses spent wash decolorization using soil as inoculum in the absence of additional carbon and nitrogen source.  

PubMed

The aim of this study was to achieve maximum decolorization of molasses spent wash (MSW) in absence of any additional carbon or nitrogen source using soil as inoculum. Soil samples were collected from the MSW disposal site. Colored soil samples exhibited higher pH, sugar and protein as compare to less colored samples. A decolorization of 69% was obtained using 10% (w/v) soil and 12.5% (v/v) MSW after 7 days incubation. Optimized parameters including days--6 days, pH--6, MSW--12.5% and soil concentration--40%, were obtained for maximum decolorization. A decolorization of 81% was achieved using 10% soil and 12.5% MSW after 18 days incubation in absence of any media supplement. Nearly 12% reduction in decolorization activity of the soil sample was observed over a period of 12 months when stored at 6 degrees C. It could be concluded that the decolorization of MSW might be achieved using soil as inoculum without addition of chemical amendments. PMID:16314089

Adikane, H V; Dange, M N; Selvakumari, K

2006-11-01

45

Hand WashingHand Washing Germ Fighting 101  

E-print Network

Hand WashingHand Washing Germ Fighting 101 Hand washing may be a simple task, but it is extremely important in preventing the spread of contagious illnesses. Wash your hands often to remove disease-causing germs. Wash your hands: Wet hands with warm water. When warm water isn't available, wash for a longer

46

Electrochemical isolation of Np from circulating carbonate solutions  

SciTech Connect

Continuous electrochemical isolation of Np from aqueous potassium carbonate (0.1-2.0 M) as an insoluble double carbonate of NpO{sub 2}{sup +} that is formed during electrochemical reduction of NpO{sub 2}{sup 2+} at a bulk reticulated vitreous carbon (RVC) electrode in a circulating electrolyzer is demonstrated. The electrochemical reactions of Np in aqueous potassium carbonate are investigated. The process parameters for isolating Np (working electrode potential, starting [Np] and [K{sub 2}CO{sub 3}], solution flow rate through the electrolyzer) are optimized. The maximum extraction of Np reached 99%.

Kosyakov, V.N.; Simirskaya, G.P.

1995-03-01

47

Viability and functional integrity of washed platelets  

SciTech Connect

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.

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

1989-07-01

48

Wash This Way  

NSDL National Science Digital Library

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.

Society, American C.

2011-01-01

49

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...

50

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...

51

Development assessment of wash water reclamation  

NASA Technical Reports Server (NTRS)

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.

Putnam, D. F.

1976-01-01

52

Recycling truck wash water  

SciTech Connect

The thousands of waste haulers operating in the US not only transport waste but also generate some of their own. Although cleaning schedules vary among these operations, which number about 9000, truck washing is an integral part of maintenance that may occur daily at many facilities. The presence of organic contaminants in the wash and rinse water, however, pose a threat to the ground and fresh water supplies. In recent years, regulators have begun to monitor closely the wastewater discharge from truck washing at waste hauling operations. Some waste haulers have found an easy, cost-effective way to comply with discharge permits is to treat and reuse the wash water.

Fink, R.G. [RGF Environmental Group, West Palm Beach, FL (United States)

1997-09-01

53

Wash water recovery system  

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

54

Hand WashingHand Washing Germ Fighting 101  

E-print Network

Hand WashingHand Washing Germ Fighting 101 Hand washing may be a simple task, but it is extremely important in preventing the spread of contagious illnesses in child-care settings. Wash your hands often to remove disease-causing germs. Wash your hands upon arrival to the child-care setting in addition to: Wet

55

Inhibition Of Washed Sludge With Sodium Nitrite  

SciTech Connect

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.

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

2012-09-25

56

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

57

Adsorption of selected herbicides from aqueous solutions on activated carbon  

Microsoft Academic Search

The adsorption of MCPA and 2,4-D on the activated carbon Filtrasorb 300 was studied. The adsorption isotherms of herbicides\\u000a from aqueous solutions were measured over a wide range of solute concentrations and at different temperatures. The experimental\\u000a equilibrium data were analyzed by the Langmuir–Freundlich isotherm taking into account the energetic heterogeneity of adsorption\\u000a system. The effect of temperature and herbicide

A. Derylo-Marczewska; M. Blachnio; A. W. Marczewski; A. Swiatkowski; B. Tarasiuk

2010-01-01

58

Cutting Of Carbon Nanotubes Via Solution Plasma Processing  

Microsoft Academic Search

A simple solution plasma process was developed for cutting multi-wall carbon nanotubes (MWCNTs). During the solution plasma\\u000a processing, defects and oxygen-containing functional groups (hydroxyl or carboxylic acid groups) were introduced onto the\\u000a sidewalls of the MWCNTs via hydroxyl radicals. After being cut for 30 min, short MWCNTs of 100–400 nm in length were obtained.

D. G. Tong; Y. Y. Luo; W. Chu; Y. C. Guo; W. Tian

2010-01-01

59

Probing Electrostatic Potentials in Solution with Carbon Nanotube  

E-print Network

Probing Electrostatic Potentials in Solution with Carbon Nanotube Transistors Lisa Larrimore the electrostatic potential sensed by the nanotube, which in turn shifts the gate-voltage dependence of the nanotube of the electrostatic ( ) and chemical (µi) potentials: Amperometric techniques (i.e., measurements of current) provide

McEuen, Paul L.

60

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

NASA Astrophysics Data System (ADS)

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).

Ghaedi, Mehrorang; Kokhdan, Syamak Nasiri

2015-02-01

61

Proper hand washing (image)  

MedlinePLUS

... handwashing include: Take off any jewelry Hold your hands pointing down under warm water for 15 to ... Steps for proper hand washing include: Take off any jewelry. Hold your hands pointing down under warm water for 15 to 30 seconds. ...

62

TANK 7 CHARACTERIZATION AND WASHING STUDIES  

SciTech Connect

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.

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

2010-02-04

63

Simultaneous leaching and carbon sequestration in constrained aqueous solutions  

SciTech Connect

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.

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

2011-01-01

64

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

Microsoft Academic Search

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

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

1988-01-01

65

Insights into non-Fickian solute transport in carbonates  

PubMed Central

[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

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

2013-01-01

66

Soil washing technology evaluation  

SciTech Connect

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.

Suer, A.

1995-04-01

67

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

PubMed

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

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

2013-11-01

68

Efficacy of 1.5% Dish Washing Solution and 95% Lemon Water in Substituting Perilous Xylene as a Deparaffinizing Agent for Routine H and E Staining Procedure: A Short Study  

PubMed Central

Aim. To assess the efficacy of dish washing solution and diluted lemon water in deparaffinizing sections during conventional hematoxylin and eosin staining technique. Objective. The objective is to utilize eco-friendly economical substitute for xylene. Materials and Methods. Using twenty paraffin embedded tissue blocks, three sections each were prepared. One section was stained with conventional H and E method (Group A) and the other two sections with xylene-free (XF) H and E (Groups B and C). Staining characteristics were compared with xylene and scoring was given. Total score of 3–5 was regarded as adequate for diagnosis and less than that inadequate for diagnosis. Statistical Analysis. Chi-square test, Kruskal Wallis ANOVA test, and Mann-Whitney U test were used. Results. Adequacy of nuclear staining, crispness, and staining for diagnosis were greater in both Groups A and C (100%) than Group B (95%). Adequacy of cytoplasmic staining was similar in all the three groups (100%). Group B showed comparatively superior uniform staining and less retention of wax. Conclusion. Dish washing solution or diluted lemon water can be replaced for xylene as deparaffinizing agent in hematoxylin and eosin procedure. PMID:24800109

Ananthaneni, Anuradha; Namala, Srilekha; Guduru, Vijay Srinivas; Ramprasad, V. V. S.; Ramisetty, Sabitha Devi; Udayashankar, Urmila; Naik, Kiran Kumar

2014-01-01

69

Efficacy of 1.5% dish washing solution and 95% lemon water in substituting perilous xylene as a deparaffinizing agent for routine h and e staining procedure: a short study.  

PubMed

Aim. To assess the efficacy of dish washing solution and diluted lemon water in deparaffinizing sections during conventional hematoxylin and eosin staining technique. Objective. The objective is to utilize eco-friendly economical substitute for xylene. Materials and Methods. Using twenty paraffin embedded tissue blocks, three sections each were prepared. One section was stained with conventional H and E method (Group A) and the other two sections with xylene-free (XF) H and E (Groups B and C). Staining characteristics were compared with xylene and scoring was given. Total score of 3-5 was regarded as adequate for diagnosis and less than that inadequate for diagnosis. Statistical Analysis. Chi-square test, Kruskal Wallis ANOVA test, and Mann-Whitney U test were used. Results. Adequacy of nuclear staining, crispness, and staining for diagnosis were greater in both Groups A and C (100%) than Group B (95%). Adequacy of cytoplasmic staining was similar in all the three groups (100%). Group B showed comparatively superior uniform staining and less retention of wax. Conclusion. Dish washing solution or diluted lemon water can be replaced for xylene as deparaffinizing agent in hematoxylin and eosin procedure. PMID:24800109

Ananthaneni, Anuradha; Namala, Srilekha; Guduru, Vijay Srinivas; Ramprasad, V V S; Ramisetty, Sabitha Devi; Udayashankar, Urmila; Naik, Kiran Kumar

2014-01-01

70

Soil washing treatability study  

SciTech Connect

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.

Krstich, M.

1995-12-01

71

Domestic wash water reclamation  

NASA Technical Reports Server (NTRS)

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.

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

1974-01-01

72

Fluidic delivery of homogeneous solutions through carbon tube bundles  

NASA Astrophysics Data System (ADS)

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.

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

2009-07-01

73

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

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

74

The regeneration of polluted activated carbon by radiation techniques  

NASA Astrophysics Data System (ADS)

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

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

1998-10-01

75

Modeling Chromium (VI) Biosorption by Acid Washed Crab Shells  

E-print Network

Modeling Chromium (VI) Biosorption by Acid Washed Crab Shells Catherine Hui Niu Dept. of Chemical for metal finishing industries. Among the pollutants, hexavalent chromium, such as chromate (CrO4 2Ã? technique for effectively adsorbing ani- onic chromium (VI) species from aqueous solution. The acid washed

Volesky, Bohumil

76

Wheat Evolution: Dough Washing  

NSDL National Science Digital Library

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.

Biotechnology and Biological Sciences Research Council

2012-01-01

77

Washing Out the Competition  

NASA Technical Reports Server (NTRS)

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.

2001-01-01

78

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

79

Comparison of solution and crystal properties of Co(II)substituted human carbonic anhydrase II  

E-print Network

Comparison of solution and crystal properties of Co(II)­substituted human carbonic anhydrase II: Carbonic anhydrase Metalloenzyme Cobalt substitution Crystallography Carbon dioxide a b s t r a c t The visible absorption of crystals of Co(II)­substituted human carbonic anhydrase II (Co(II)­HCA II) were

Tanner, David B.

80

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

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.

Peters, T. B.

2014-01-02

81

Carbon dioxide capture capacity of sodium hydroxide aqueous solution.  

PubMed

The present paper investigates the various features of NaOH aqueous solution when applied as an absorbent to capture carbon dioxide (CO(2)) emitted with relatively high concentration in the flue gas. The overall CO(2) absorption reaction was carried out according to consecutive reaction steps that are generated in the order of Na(2)CO(3) and NaHCO(3). The reaction rate and capture efficiency were strongly dependent on the NaOH concentration in the Na(2)CO(3) production range, but were constant in the NaHCO(3) production step, irrespective of the NaOH concentration. The amount of CO(2) absorbed in the solution was slightly less than the theoretical value, which was ascribed to the low trona production during the reaction and the consequent decrease in CO(2) absorption in the NaOH solution. The mass ratio of absorbed CO(2) that participated in the Na(2)CO(3), NaHCO(3), and trona production reactions was calculated to be 20:17:1, respectively. PMID:23183145

Yoo, Miran; Han, Sang-Jun; Wee, Jung-Ho

2013-01-15

82

Study of the reuse of treated wastewater on waste container washing vehicles.  

PubMed

The wheelie bins for the collection of municipal solid waste (MSW) shall be periodically washed. This operation is usually carried out by specific vehicles which consume about 5000 L of water per day. Wastewater derived from bins washing is usually stored on the same vehicle and then discharged and treated in a municipal WWTP. This paper presents a study performed to evaluate the reuse of the wastewater collected from bins washing after it has been treated in a small plant mounted on the vehicle; the advantage of such a system would be the reduction of both vehicle dimension and water consumption. The main results obtained by coagulation-flocculation tests performed on two wastewater samples are presented. The addition of 2 mL/L of an aqueous solution of aluminum polychloride (18% w/w), about 35 mL/L of an aqueous solution of CaO (4% w/w) and 25 mL/L of an aqueous solution of an anionic polyelectrolyte (1 ‰ w/w) can significantly reduce turbidity and COD in treated water (to about 99% and 42%, respectively); the concomitant increase of UV transmittance at 254 nm (up to 15%) enables UV disinfection application by a series of two ordinary UV lamps. Much higher UV transmittance values (even higher than 80%) can be obtained by dosing powdered activated carbon, which also results in a greater removal of COD. PMID:23142511

Vaccari, Mentore; Gialdini, Francesca; Collivignarelli, Carlo

2013-02-01

83

Preparation of regenerated cellulose fiber via carbonation. I. Carbonation and dissolution in an aqueous NaOH solution  

Microsoft Academic Search

Cellulose carbonate was prepared by the reaction of cellulose pulp and CO2 with treatment reagents, such as aqueous ZnCl2 (20–40 wt%) solution, acetone or ethyl acetate, at ?5–0°C and 30–40 bar (CO2) for 2 hr. Among the treatment reagents, ethyl acetate was the most effective. Cellulose carbonate was dissolved in 10% sodium\\u000a hydroxide solution containing zinc oxide up to 3

Sang Youn Oh; Dong Il Yoo; Younsook Shin; Wha Seop Lee; Seong Mu Jo

2002-01-01

84

Immunotoxicity of washing soda in a freshwater sponge of India.  

PubMed

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

Mukherjee, Soumalya; Ray, Mitali; Ray, Sajal

2015-03-01

85

Carbonic Anhydrase-Inhibitor Binding: From Solution to the Gas Phase  

E-print Network

Carbonic Anhydrase-Inhibitor Binding: From Solution to the Gas Phase Qinyuan Wu,,§ Jinming Gao stabilities of nonco- valent complexes between bovine carbonic anhydrase II (BCAII, EC 4.2.1.1) and para systems due to the stability of carbonic anhydrase (CA) and its well characterized structure and ligand

Gao, Jinming

86

Structure Controlled Synthesis of Single-Walled Carbon Nanotubes Using Solution Based Catalyst Deposition  

E-print Network

Structure Controlled Synthesis of Single-Walled Carbon Nanotubes Using Solution Based Catalyst and physical properties, single-walled carbon nanotube (SWCNT) has been considered for many applications. We, mechanical application, etc. #12;Structure Controlled Synthesis of Carbon Nanotubes Theerapol Thurakitseree1

Mellor-Crummey, John

87

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

Microsoft Academic Search

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

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

2011-01-01

88

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

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

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

2013-08-01

89

Bromate removal from aqueous solutions by ordered mesoporous carbon.  

PubMed

We investigated the feasibility of using ordered mesoporous carbon (OMC) for bromate removal from water. Batch experiments were performed to study the influence of various experimental parameters such as the effect of contact time, adsorbent dosage, initial bromate concentration, temperature, pH and effect of competing anions on bromate removal by OMC. The adsorption kinetics indicates that the uptake rate ofbromate was rapid at the beginning: 85% adsorption was completed in 1 h and equilibrium was achieved within 3 h. The sorption process was well described with pseudo-second-order kinetics. The maximum adsorption capacity of OMC for bromate removal was 17.6 mg g(-1) at 298 K. The adsorption data fit the Freundlich model well. The amount of bromate removed was found to be proportional to the influent bromate concentration. The effects of competing anions and solution pH (3-11) were negligible. These limited data suggest that OMC can be effectively utilized for bromate removal from drinking water. PMID:24645482

Xu, Chunhua; Wang, Xiaohong; Shi, Xiaolei; Lin, Sheng; Zhu, Liujia; Che, Yaming

2014-01-01

90

The application of EQCM to the study of the electrochemical behavior of propylene carbonate solutions  

Microsoft Academic Search

The electrochemical behavior of gold electrodes in propylene carbonate (PC) solutions was investigated using an electrochemical quartz crystal microbalance (EQCM). The solutions studied included uncontaminated LiAsF6 and LiPF6 solutions, and CO2 and H2O-containing LiAsF6 solutions. Surface film formation on the electrodes in these solutions was investigated during a potential scan from the open-circuit potential (OCV) to 0.5 V vs. LiLi+

D. Aurbach; A. Zaban

1995-01-01

91

Nasal Wash Treatment  

MedlinePLUS

... is filtered using a filter with an absolute pore size of 1 micron or smaller. Whichever water you use to make the saline solution replace container or water at least weekly. To make the saltwater solution, mix one-half teaspoon uniodized salt in an 8-ounce glass of water (described ...

92

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

NASA Technical Reports Server (NTRS)

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.

1983-01-01

93

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

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).

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

2012-10-25

94

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

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.

Peters, T. B.

2013-10-01

95

Hydrogen and carbon in solid solution in oxides and silicates  

NASA Astrophysics Data System (ADS)

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 dissolution of H2O are subject to a charge transfer (CT) conversion into peroxy moieties and molecular hydrogen, O{2/2-}... H2. Because the O{2/2-}moiety is small (O--O- distance ? 1.5 Å) high pressure probably favors the CT conversion. Mass spectroscopic studies show that molecular H2 may be lost from the solid which retains excess oxygen in the form of O{2/2-}, leading to the release of atomic O. The dissociation of O{2/2-}moieties into a vacancy-bound O- state and an unbound O- state can be followed by measuring the internal redox reactions involving transition metal impurities, the transient paramagnetism of the O- and their effect on the d.c. conductivity. Evidence is presented that CO2 molecules dissolve dissociatively in the structurally dense oxide matrix, as if they were first to dissociate into CO+O and then to form separate solute moieties CO{2/2-}and O{2/2-}, both associated with cation vacancy sites. In the CO{2/2-}moiety (C-O- distance 1.2 1.3 Å, OCO angle ? 130°) the C atom probably sits off center. The transition of the C atom into interstitial sites is accompanied by dissociation of the CO{2/2-}moiety into CO- and O-. This transition can be followed by infrared spectroscopy, using OH- as local probes. Further support derives from magnetic susceptibility, thermal expansion, low frequency dielectric loss and low temperature deformation measurements. The recently observed emission of O and Mg atoms besides a variety of molecules such as CO, CO2, CH4, HCN and other hydrocarbons during impact fracture of MgO single crystals is presented and discussed in the light of the other experimental data.

Freund, Friedemann

1987-10-01

96

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

NASA Astrophysics Data System (ADS)

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.

Tesch, Walter; Tesch, Petra; Pfeifer, Christoph

2013-04-01

97

Fabrication and processing of high-strength densely packed carbon nanotube yarns without solution processes.  

PubMed

Defects of carbon nanotubes, weak tube-tube interactions, and weak carbon nanotube joints are bottlenecks for obtaining high-strength carbon nanotube yarns. Some solution processes are usually required to overcome these drawbacks. Here we fabricate ultra-long and densely packed pure carbon nanotube yarns by a two-rotator twisting setup with the aid of some tensioning rods. The densely packed structure enhances the tube-tube interactions, thus making high tensile strengths of carbon nanotube yarns up to 1.6 GPa. We further use a sweeping laser to thermally treat as-produced yarns for recovering defects of carbon nanotubes and possibly welding carbon nanotube joints, which improves their Young's modulus by up to ?70%. The spinning and laser sweeping processes are solution-free and capable of being assembled together to produce high-strength yarns continuously as desired. PMID:22538869

Liu, Kai; Zhu, Feng; Liu, Liang; Sun, Yinghui; Fan, Shoushan; Jiang, Kaili

2012-06-01

98

Decolorization of anaerobically digested molasses spent wash by Pseudomonas putida.  

PubMed

The distillery wastewater (spent wash) contains dark-brown colored recalcitrant organic compounds that are not amenable to conventional biological treatment. The characteristic recalcitrance to decolorization is due to the presence of brown melanoidin polymers. In the present study, feasibility of using Pseudomonas putida strain U for decolorization of spent wash was demonstrated. Batch cultures of P. putida decolourized spent wash by 24%, 2- fold higher decolorization was achieved following immobilization in calcium alginate beads. Glucose concentration was critical for decolourization and improved color removal efficiency was obtained by periodic replenishment of glucose. Decolourization was also observed with lactose or whey as alternative carbon sources. The results of our study suggest that P. putida could be used for biological decolorization of molasses spent washes and that supplementation with whey (a by-product from cheese industry) can offer economical viability to the process. PMID:19235513

Ghosh, M; Ganguli, A; Tripathi, A K

2009-01-01

99

7 CFR 58.429 - Washing machine.  

Code of Federal Regulations, 2010 CFR

...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...

2010-01-01

100

7 CFR 58.429 - Washing machine.  

Code of Federal Regulations, 2014 CFR

...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...

2014-01-01

101

7 CFR 58.429 - Washing machine.  

Code of Federal Regulations, 2011 CFR

...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...

2011-01-01

102

7 CFR 58.429 - Washing machine.  

Code of Federal Regulations, 2013 CFR

...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...

2013-01-01

103

7 CFR 58.429 - Washing machine.  

Code of Federal Regulations, 2012 CFR

...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...

2012-01-01

104

Surface heterogeneity effects of activated carbons on the kinetics of paracetamol removal from aqueous solution  

NASA Astrophysics Data System (ADS)

The removal of a compound with therapeutic activity (paracetamol) from aqueous solutions using chemically modified activated carbons has been investigated. The chemical nature of the activated carbon material was modified by wet oxidation, so as to study the effect of the carbon surface chemistry and composition on the removal of paracetamol. The surface heterogeneity of the carbon created upon oxidation was found to be a determinant in the adsorption capability of the modified adsorbents, as well as in the rate of paracetamol removal. The experimental kinetic data were fitted to the pseudo-second order and intraparticle diffusion models. The parameters obtained were linked to the textural and chemical features of the activated carbons. After oxidation the wettability of the carbon is enhanced, which favors the transfer of paracetamol molecules to the carbon pores (smaller boundary layer thickness). At the same time the overall adsorption rate and removal efficiency are reduced in the oxidized carbon due to the competitive effect of water molecules.

Ruiz, B.; Cabrita, I.; Mestre, A. S.; Parra, J. B.; Pires, J.; Carvalho, A. P.; Ania, C. O.

2010-06-01

105

Nonionic Organic Solute Sorption to two Organobentonites as a Function of Organic-Carbon Content  

NASA Astrophysics Data System (ADS)

Sorption of three nonionic organic solutes (benzene, trichloroethene, and 1,2-dichlorobenzene) to hexadecyltrimethylammonium-bentonite (HDTMA-bentonite) and benzyltrimethylammonium-bentonite (BTEA-bentonite) was measured as a function of organic-carbon content at quaternary ammonium cation loadings ranging from 30 to 130% of the clay's cation-exchange capacity. Sorption of all three solutes to HDTMA-bentonite was linear and sorptive capacity of the HDTMA-bentonite increased as the organic-carbon content of the clay increased. 1,2-Dichlorobenzene sorbed most strongly to HDTMA-bentonite, followed by benzene and TCE. The stronger sorption of benzene to HDTMA-bentonite compared to TCE was unexpected based on a partition mechanism of sorption and consideration of solute solubility. This result may be caused by interactions between the pi electrons of benzene and the negatively charged surface of the clay. Log Koc values for all three solutes increased with organic-carbon content. This suggests that the increased organic-carbon content alone may not explain the observed increase in sorption capacity. Sorption of the three solutes to BTEA-bentonite was nonlinear and solute sorption decreased with increasing organic-carbon content. Surface area measurements indicate that the surface area of both organobentonites generally decreased with increasing organic-carbon content. Since nonionic organic solute sorption to BTEA-bentonite occurs by adsorption, the reduced sorption is likely caused by the reduction in surface area corresponding to increased organic cation loading.

Bartelt-Hunt, S. L.; Burns, S. E.; Smith, J. A.

2002-05-01

106

Thermodynamic properties of carbon in b.c.c. and f.c.c. iron-silicon-carbon solid solutions.  

NASA Technical Reports Server (NTRS)

The equilibrium between hydrogen-methane gas mixtures and Fe-Si-C solid solutions has been investigated both as a function of temperature and carburizing gas composition. The thermodynamic properties of the carbon atoms in both b.c.c. and f.c.c. solid solution have been derived from the equilibrium measurements. The results found have been compared with those of earlier investigations and with the predictions of recent theoretical models on ternary solid solutions containing both substitutional and interstitial solute atoms.

Chraska, P.; Mclellan, R. B.

1971-01-01

107

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

SciTech Connect

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%.

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

2007-08-15

108

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

E-print Network

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, ...

Mao, Xianwen

109

Efficacy of Post-Wash Shell Egg Sanitizers  

Technology Transfer Automated Retrieval System (TEKTRAN)

Chlorine (Cl) solutions of 100-200 ppm are the standard by which post-wash shell egg sanitizers are measured. Any facility that packages eggs with the USDA grade shields must use a comparable sanitizer. While chlorine solutions are inexpensive, non-corrosive, and safe to handle, they are not very ...

110

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

PubMed

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

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

111

Reactions of rare earth flourides with sodium carbonate and hydroxide solutions  

Microsoft Academic Search

Exchange interactions of sparingly soluble rare earth (RE) compounds such as fluorides, carbonates, and hydroxides in aqueous media are studied. The starting materials were fluorides of individual RE, obtained by precipitation with hydrofluoric acid from solutions of RE nitrates, which were prepared from the corresponding oxides of 99.9% and taken to the air-dry state, and also cp sodium carbonate and

E. L. Chuviliana; N. V. Baryshnikov; I. F. Poletaev

1986-01-01

112

Vapor pressure data for potassium carbonate-potassium bicarbonate solutions for application to multiuse power cycles  

Microsoft Academic Search

A novel method of generating electric power based on a gas absorption cycle, rather than a normal Rankine steam power cycle, has been developed. This cycle uses carbon dioxide as the working fluid in the turbine and potassium carbonate solutions as the carrier fluid for the absorption part of the cycle. Thermodynamic calculations for typical operating parameters show a cycle

E. R. Hosler; S. Ghandeharioun

1983-01-01

113

Enhanced sludge washing evaluation plan  

SciTech Connect

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.

Jensen, R.D.

1994-09-01

114

Inhibitive effects of palm kernel oil on carbon steel corrosion by alkaline solution  

NASA Astrophysics Data System (ADS)

The behavior of carbon steel SAE 1045 in 1 M NaOH solution containing different concentrations of palm kernel oil (PKO) has been studied by weight loss and polarization measurement. Results showed that the corrosion of carbon steel in NaOH solution was considerably reduced in presence of such inhibitors. The inhibition efficiency increases when concentration of inhibitor increase. Maximum inhibition efficiency (? 96.67%) is obtained at PKO concentration 8 v/v %. This result revealed that palm kernel oil can act as a corrosion inhibitor in an alkaline medium. Corrosion rates of carbon steel decrease as the concentration of inhibitor is increased.

Zulkafli, M. Y.; Othman, N. K.; Lazim, A. M.; Jalar, A.

2013-11-01

115

Corrosion Behavior of Mild Carbon Steel in Ethanolic Solutions  

NASA Astrophysics Data System (ADS)

Electrochemical evaluation of ASTM A36 steel was performed in ethanolic solutions containing small concentrations of water ranging from 0 to 10 vol.%. Electrochemical techniques such as open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization were utilized to analyze corrosion parameters. A fixed concentration of chloride, as per the ASTM specification for fuel grade ethanol, was added to increase the conductivity of the solutions. The effects of water and oxygen on the corrosion behavior of steel in these solutions have been discussed. Pitting corrosion of the steel specimens in these solutions was evaluated using scanning electron microscopy (SEM) and pitting analysis. This investigation was performed to establish a baseline for the microbiologically influenced corrosion (MIC) of steel in ethanolic solutions.

Bhola, Shaily M.; Bhola, Rahul; Jain, Luke; Mishra, Brajendra; Olson, David L.

2011-04-01

116

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

Microsoft Academic Search

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

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

1990-01-01

117

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...

118

Mechanism of adsorption and electrosorption of bentazone on activated carbon cloth in aqueous solutions.  

PubMed

An electrochemical technique has been applied to enhance the removal of a common herbicide (bentazone) from aqueous solutions using an activated carbon cloth as electrode. A pH increase from acidic to basic reduces the uptake, with capacities going from 127 down to 80 mg/g at pH 2 and 7, respectively. Increasing the oxygen content of the carbon cloth causes a decrease in the bentazone loading capacity at all pH values. This indicates that adsorption is governed by both dispersive and electrostatic interactions, the extent of which is controlled by the solution pH and the nature of the adsorbent. Anodic polarization of the carbon cloth noticeably enhances the adsorption of bentazone, to an extent depending on the current applied to the carbon electrode. The electrosorption is promoted by a local pH decrease provoked by anodic decomposition of water in the pores of the carbon cloth. PMID:17490705

Ania, Conchi O; Béguin, François

2007-08-01

119

Washing Fresh Fruits and Vegetables  

E-print Network

are expensive and they are not recommend- ed by any federal agency to clean fresh produce. Fruit and vegetable waxes Some fruits and vegetables may have waxy coatings to keep them fresh, to protect them from bruising and to prevent the growth of mold. Waxes... also make fruits and vegetables more at- tractive. These waxes are safe to eat. Washing fresh produce with water may not remove the wax, but soap should not be used to wash fresh produce. If you prefer, you can remove the waxed skin before eating...

Scott, Amanda

2008-09-05

120

Wash flow disturbance and summer wash flow in the Mojave Desert: Influence on dispersion, production, and physiological functioning of dominant shrubs  

NASA Astrophysics Data System (ADS)

In many Mojave Desert ecosystems, water infiltrates to root-zones in greatest proportion via washes. As such, washes have a pronounced effect on plant dispersion and size across these landscapes. Desert roads alter the natural spatial patterns of washes on alluvial fans (locally called bajadas) and potentially affect plant production and distribution. As a winter-rainfall dominated ecosystem, climate changes in the Mojave Desert that increase summer precipitation may also play an important role in altering vegetation processes influenced by washes. Road effects on the spatial distribution of desert plants on a Mojave Desert bajada were examined using remotely sensed LiDAR data and ground based measurements of plant size. Plant physiological responses to summer wash flow were also quantified by measuring gas exchange and water status of two dominant perennial species, Larrea tridentata and Ambrosia dumosa. Larrea and Ambrosia plants were nearly 7x and 4x larger where wash flow has been enhanced by road culverts, relative to undisturbed areas and areas where flow has been cut-off by the presence of a road/railroad. Clustering of large plants occurred along wash margins, with clustering most pronounced in areas of enhanced wash flow. No clustering was found where wash flow has been eliminated. For ecophysiological traits, both species showed pronounced responses to the pulse of water; however, these responses varied as a function of distance from wash. Larrea plants within 3 m and Ambrosia plants within ca. 2 m from the wash responded to the pulse of water. Leaf phenology dictated the timing of carbon gain as Larrea experienced a rapid but short-lived increase in stomatal conductance compared to a significant response for over a month following the pulse for Ambrosia. These results indicate that disturbance of desert washes has a pronounced impact on vegetation structure, and changing climatic conditions that impact plant function could potentially lead to even greater vegetation shifts through time.

Newlander, April

121

Alkaline solution absorption of carbon dioxide method and apparatus  

DOEpatents

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.

Hobbs, D.T.

1991-01-01

122

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

DOEpatents

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.

Rau, Gregory Hudson (Castro Valley, CA)

2012-05-15

123

Effect of extraction solutions on carbonation of cementitious materials in aqueous solutions  

Microsoft Academic Search

Carbonation efficiency was evaluated for three cementitious materials having different CaO-bearing minerals (lime, Portland cement and waste concrete) using various extraction reagents (HCl, CH3COOH, NH4Cl and deionized water). The cementitious materials were subjected to Ca extraction and carbonation tests under ambient pressure and temperature conditions. The Ca extraction efficiency generally decreased in the order lime, Portland cement and waste concrete,

Hwanju Jo; Ho Young Jo; Young-Nam Jang

2011-01-01

124

Effect of extraction solutions on carbonation of cementitious materials in aqueous solutions  

Microsoft Academic Search

Carbonation efficiency was evaluated for three cementitious materials having different CaO-bearing minerals (lime, Portland cement and waste concrete) using various extraction reagents (HCl, CH3COOH, NH4Cl and deionized water). The cementitious materials were subjected to Ca extraction and carbonation tests under ambient pressure and temperature conditions. The Ca extraction efficiency generally decreased in the order lime, Portland cement and waste concrete,

Hwanju Jo; Ho Young Jo; Young-Nam Jang

2012-01-01

125

Characterization of Solution-Processed Double-Walled Carbon Nanotube/  

E-print Network

on storage modulus, Tc, Tm and Tg of PVDF is studied. Electromechani- cal strain is observed at low actuation polymers by lowering the actuation voltage and increasing strain and stress response. In this work, piezo- electric PVDF and DWNTs are solution- cast into films. SEM of fracture surfaces confirms good dispersion

Ounaies, Zoubeida

126

A basket for washing benthological samples  

USGS Publications Warehouse

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.

Selgeby, James H.

1971-01-01

127

Defect studies on as-synthesized and purified carbon nanostructures produced by arc-discharge in solution process.  

PubMed

Carbon nanostructures are synthesized using a novel arc-discharge in solution process. A multitude of defects on nanotubes and nanostructures is found. Evidence of these defects in as-synthesized carbon nanostructures is explored using high-resolution transmission electron microscopy (HRTEM). Tri-, tetra-, penta-, hexa-, heptagonal, toroidal, oval, and spherical nanoshells are found in HRTEM investigation along with carbon nanotubes, carbon nanohorns, carbon rods, nanoporous carbon, dislodged graphene sheets, and amorphous carbon. Purifications are carried out through two oxidation methods to eliminate the amorphous carbon. Several different defects caused by oxidations are also found in purified samples. PMID:16736770

Bera, Debasis; Perrault, Jean-Philippe; Heinrich, Helge; Seal, Sudipta

2006-04-01

128

Density and viscosity of some partially carbonated aqueous alkanolamine solutions and their blends  

SciTech Connect

Very little information is available concerning the effect of acid gas loading on the physical properties of amine-treating solutions flowing through the absorption and regeneration columns used in gas processing. The densities and viscosities of partially carbonated monoethanolamine (MEA), diethanolamine (DEA), and N-methyldiethanolamine (MDEA) solutions were measured at 298 K. With increasing carbon dioxide loadings, significant increases in both density and viscosity were observed. These results were combined with literature data to produce correlations for alkanolamine solution density and viscosity as a function of amine concentration, carbon dioxide loading, and temperature. The resulting single-amine correlations were used to predict the densities and viscosities of DEA + MDEA and MEA + MDEA blends. Predictions are compared with data measured for these blends.

Weiland, R.H.; Dingman, J.C.; Cronin, D.B.; Browning, G.J. [Optimized Gas Treating, Inc., Houston, TX (United States)] [Optimized Gas Treating, Inc., Houston, TX (United States)

1998-05-01

129

Sorption of platinum and rhodium on carbon adsorbents from chloride solutions  

Microsoft Academic Search

Sorption recovery of platinum (II, IV) and rhodium (III) on different carbon adsorbents has been studied using fresh chloride\\u000a model solutions with platinum and rhodium concentrations of 0.25–1.0 and 0.049 mmol\\/L, respectively. The concentration of\\u000a hydrochloric acid in these solutions varied from 0.001 to 1.0 mol\\/L. The maximum recovery of platinum and rhodium was achieved\\u000a with the carbon adsorbent based on charcoal

Olga N. Kononova; Tatiana A. Leyman; Victoriya N. Gavrilova; Sergey G. Konontsev; Dmitry M. Kashirin

2010-01-01

130

Dry-spraying of ascorbic acid or acetaminophen solutions with supercritical carbon dioxide  

NASA Astrophysics Data System (ADS)

Carbon dioxide is a very poor solvent for many organic compounds, which makes it a good anti-solvent. When a solution is sprayed into carbon dioxide vapour the anti-solvent reduces the solubility within several tens of milliseconds and the solute precipitates. Two distinct regions can be identified, below and above the mixture critical pressure. Below this critical pressure the yield remains relatively low and the process is not well controlled. Above the critical pressure small crystals are obtained of about 2 ?m with a yield of 90%.

Wubbolts, F. E.; Bruinsma, O. S. L.; van Rosmalen, G. M.

1999-03-01

131

Solution and shock-induced exsolution of argon in vitreous carbon  

NASA Technical Reports Server (NTRS)

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.

Gazis, Carey; Ahrens, Thomas J.

1991-01-01

132

[Distribution patterns of PAHs in soils from coking plant and the particle-size cut points of soil washing].  

PubMed

Soil particle size distribution and contaminants distribution patterns in different soil size fractions are the basis of soil treatability using soil washing method. Soil particle-size cut points are important parameters of soil washing process. According to ex situ soil washing technology, soil samples were collected in a former coking plant. The soil particle size distribution and the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in USEPA priority list were analyzed. Tween 80 and Triton X-100 solutions were used to clean the polluted soil with different particle size. Results showed that the total concentrations of 16 PAHs ranged from 6.27 to 40.18 mg/kg dry weight in the six soil size fractions and present a bimodal distribution. The maximum individual PAH concentration mostly occurred in the 250-500 microm size fraction. The lowest individual PAH concentration was in the 50-75 microm size fraction. The removal efficiencies of PAHs in different soil size fractions depended on their initial concentrations and the characteristics of soil. The PAHs removal efficiencies in coarser size fractions were lower than that in the finer size fractions owing to their higher organic carbon content. Based on the removal efficiency of PAHs in each soil size fractions by surfactant solution and the requirements of waste volume reduction, 50 microm was determined as the particle-size cut point. Then, 82.95% volume reduction can be achieved. PMID:21717762

Li, He-Lian; Chen, Jia-Jun; Wu, Wei; Piao, Xue-Song; Jiang, Lin; Shi, Zhen-Tian; Sun, Tian-Wei

2011-04-01

133

When and How to Wash Your Hands  

MedlinePLUS

... gov Share Compartir When & How to Wash Your Hands Esta página en español Keeping hands clean through ... to clean hands. When should you wash your hands? Before, during, and after preparing food Before eating ...

134

27 CFR 19.328 - Wash water.  

Code of Federal Regulations, 2010 CFR

...and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DISTILLED SPIRITS PLANTS Production Chemical By-Products § 19.328 Wash water. Water used in washing chemicals to remove spirits...

2010-04-01

135

Electricity solutions for a carbon-constrained future  

SciTech Connect

A successful response to the threat of climate change will require substantial technical work as well as practical problem solving in the political, regulatory and public areas. EPRI's 2007 Summer Seminar brought together regulatory, industry, academic, and policy leaders to discuss critical issues and delineate the initiating actions required to begin resolving the climate dilemma. Although the global nature of climate change amplifies its complexity and uncertainly, technology must play a leading role in winnowing opportunity from challenge and crafting a viable solution. 6 figs.

Schimmoller, B. [EPRI (United States)

2007-09-30

136

Erosion accelerated corrosion of a carbon steel–stainless steel galvanic couple in a chloride solution  

Microsoft Academic Search

In this work, the galvanic corrosion and erosion-accelerated corrosion of a 1020 carbon steel–304L stainless steel galvanic couple were investigated in a chloride solution using various electrochemical measurements and scanning electron microscopy observation. It was found that the average galvanic current density of the galvanic couple increases with the cathode\\/anode area ratio and the flow velocity of the solution. There

C. F. Dong; K. Xiao; X. G. Li; Y. F. Cheng

2010-01-01

137

Simultaneous determination of uric acid and ascorbic acid using glassy carbon electrodes in acetate buffer solution  

Microsoft Academic Search

The present work reports the simultaneous determination of uric acid (UA) and ascorbic acid (AA) in 0.2M, pH 4.0, acetate buffer solution using glassy carbon (GC) electrode by square wave voltammetry. Selective detection of UA in the presence of 200-fold excess of AA is achieved at the GC electrode in acetate buffer solution. The GC electrode separates the voltammetric signal

S. Abraham John

2005-01-01

138

Kinetics and thermodynamics studies of chromium(VI) ions adsorption onto activated carbon from aqueous solutions  

Microsoft Academic Search

The removal of chromium(VI) from aqueous solutions by activated carbon has been investigated as a function of solution pH, initial chromium concentration C, solid\\/liquid ratio R and temperature T. The Freundlich and the Langmuir models have been applied and the equilibrium adsorption was found to best fit the Langmuir adsorption isotherm, where good correlation between theoretical and experimental equilibrium concentration

M. Barkat; D. Nibou; S. Chegrouche; A. Mellah

2009-01-01

139

Adsorption of organic acids from dilute aqueous solution onto activated carbon  

SciTech Connect

The radioisotope technique was used to study the removal of organic acid contaminants from dilute aqueous solutions onto activated carbon. Acetic acid, propionic acid, n-butyric acid, n-hexanoic acid and n-heptanoic acid were studied at 278, 298, and 313/sup 0/K. Three bi-solute acid mixtures (acetic and propionic acids, acetic and butanoic acids, and propionic and butanoic acids) were studied at 278 and 298/sup 0/K. Isotherms of the single-solute systems were obtained at three different temperatures in the very dilute concentration region (less than 1% by weight). These data are very important in the prediction of bi-solute equilibrium data. A Polanyi-based competitive adsorption potential theory was used to predict the bi-solute equilibrium uptakes. Average errors between calculated and experimental data ranges from 4% to 14%. It was found that the competitive adsorption potential theory gives slightly better results than the ideal adsorbed solution theory.

Wang, S.W.

1980-06-01

140

CO2 adsorption on modified carbon coated monolith: effect of surface modification by using alkaline solutions  

NASA Astrophysics Data System (ADS)

A monolithic column was used to study the feasibility of modified carbon-coated monolith for recovery of CO2 from gaseous mixtures (He/CO2) in a variety of operating conditions. Carbon-coated monolith was prepared by dip-coating method and modified by two alkaline solutions, i.e. NH3 and KOH. The surface properties of the carbon-coated monolith were altered by functional groups via KOH and NH3 treatments. The comparative study of CO2 uptake by two different adsorbents, i.e. unmodified and modified carbon-coated monolith, demonstrated that the applied modification process had improved CO2 adsorption. The presence of nitrogen- and oxygen-containing functional groups on the surface of the carbon led to an improved level of microporosity on the synthesized carbon-coated monolith. The physical parameters such as higher surface area, lower pore diameter, and larger micropore volume of modified monoliths indicated direct influence on the adsorbed amount of CO2. In the present study, the Deactivation Model is applied to analyze the breakthrough curves. The adsorption capacity increased with an increase in pressure and concentration, while a reduction of CO2 adsorption capacity was occurred with increase in temperature. Ammonia (NH3) and potassium hydroxide (KOH)-modified carbon-coated monolith showed an increase of approximately 12 and 27% in CO2 adsorption, respectively, as compared to unmodified carbon-coated monolith.

Hosseini, Soraya; Marahel, Ehsan; Bayesti, Iman; Abbasi, Ali; Chuah Abdullah, L.; Choong, Thomas S. Y.

2015-01-01

141

First Molecular Dynamics simulation insight into the mechanism of organics adsorption from aqueous solutions on microporous carbons  

NASA Astrophysics Data System (ADS)

The results of 84 MD simulations showing the influence of porosity and carbon surface oxidation on adsorption of three organic compounds from aqueous solutions on carbons are reported. Based on a model of 'soft' activated carbon, three carbon structures with gradually changed microporosity were created. Next, different number of surface oxygen groups was introduced. We observe quantitative agreement between simulation and experiment i.e. the decrease in adsorption from benzene down to paracetamol. Simulation results clearly demonstrate that the balance between porosity and carbon surface chemical composition in organics adsorption on carbons, and the pore blocking determine adsorption properties of carbons.

Terzyk, Artur P.; Gauden, Piotr A.; Zieli?ski, Wojciech; Furmaniak, Sylwester; Weso?owski, Rados?aw P.; Klimek, Kamil K.

2011-10-01

142

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

Microsoft Academic Search

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

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

2001-01-01

143

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

SciTech Connect

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.

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

2001-11-15

144

Computer simulation of cascade damage in -iron with carbon in solution  

SciTech Connect

Computer simulation of cascade damage in -iron with carbon in solution Original Research Article Journal of Nuclear Materials, Volume 382, Issues 2 3, 1 December 2008, Pages 91-95 Andrew F. Calder, David J. Bacon, Alexander V. Barashev, Yuri N. Osetsky

Calder, Andrew F [ORNL; Bacon, David J [University of Liverpool; Barashev, Aleksandr [University of Liverpool; Osetsky, Nickolai [ORNL

2008-01-01

145

Raman studies of suspensions and solutions of singlewall carbon nanotubes , A. Pnicaud2  

E-print Network

Raman spectroscopy is used to probe the structure and electronic properties of nanotubes dispersed in polar organic solvents [4]. Raman spectroscopy is the most popular technique to characterize samplesRaman studies of suspensions and solutions of singlewall carbon nanotubes N. Izard1 , A. Pénicaud2

Boyer, Edmond

146

Investigations of optical limiting mechanisms in carbon particle suspensions and fullerene solutions  

NASA Astrophysics Data System (ADS)

Liquid suspensions of carbon act as optical limiters in the presence of high-intensity Q-switched laser pulses. The optical limiting is a result of optical breakdown, which is initiated by absorption in the small carbon particles. We measured the total energy scattered during the breakdown process and the angular distribution of the scattered light as a function of input energy. We also compared the relative scattered energy created during limiting in the carbon suspensions with that generated in solutions of fullerenes in toluene. The ratio of scattered to absorbed energy is different for the suspensions from that for the fullerene solutions, indicating that different mechanisms dominate the limiting processes in the two media.

Nashold, Karen M.; Powell Walter, Diane

1995-07-01

147

Bio-desulfurization and denitrification by anaerobic-anoxic process for the treatment of wastewater from flue gas washing.  

PubMed

For amine-based carbon dioxide capture, nitrogen oxides and sulfur oxides were the main pollutants that had a negative effect on the regeneration of solvent. Before carbon dioxide capture, the sulfur oxides in flue gas should be removed by the method of calcium salt, and then washed by alkaline solution to eliminate the residual nitrogen oxides and sulfur oxides. The washing wastewater containing sulfate and nitrate needs to be treated. In this study, a novel anaerobic-anoxic process was built up for the treatment of this washing wastewater. Nitrate was reduced to nitrogen by denitrifying bacteria. Sulfate was firstly reduced to sulfide by sulfate reducing bacteria, and then selectively oxidized to element sulfur by sulfide oxidizing bacteria. The treated liquid could be reused as absorption after the adjustment of pH value. The performances of this bioprocess were investigated under various pH values and S/N ratios. It was found that the optimal pH value of influent was 6.0, the percentages of denitrification and sulfate reducing could reach 90 and 89%, respectively. Seventy-six percent of sulfate was transformed into element sulfur. Nitrate significantly had a negative effect on sulfate reduction above 10 mM. As 20 mM nitrate, the sulfate reducing percentage would drop to 67%. These results showed that the anaerobic-anoxic process was feasible for the treatment of flue gas washing wastewater. It would be prospectively applied to other wastewater with the higher ratio of SO4(2-)/NO3(-). PMID:23656948

Song, Ziyu; Zhou, Xuemei; Li, Yuguang; Yang, Maohua; Xing, Jianmin

2013-01-01

148

An oxidative carbon-carbon bond formation system in cycloalkane-based thermomorphic multiphase solution.  

PubMed

A selective anodic oxidation system in which a carbocation intermediate is generated exclusively by use of a temperature-controlled multiphase solution to separate the different stages of the reaction from each other and from the products is described. The formation of a thermomorphic middle layer in an electrolytic solution composed of c-Hex and LPC/MeNO2 results in enhanced interaction between aliphatic alkenes and polar unstable cation. PMID:18376846

Kim, Shokaku; Noda, Satoko; Hayashi, Kanako; Chiba, Kazuhiro

2008-05-01

149

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

E-print Network

Dispersion of Single-Walled Carbon Nanotubes in Aqueous Solutions of the Anionic Surfactant Na Form: October 2, 2003 The insolubility of single-walled carbon nanotubes (SWNT) in either water to different extents, the exact mechanism by which carbon nanotubes and the different surfactants interact

Resasco, Daniel

150

Approximate Solutions for a Self-Folding Problem of Carbon Nanotubes  

SciTech Connect

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.

Y Mikata

2006-08-22

151

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

DOEpatents

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.

Rau, Gregory Hudson

2014-07-01

152

Physical solubility of hydrogen sulfide and carbon dioxide in alkanolamine solutions  

SciTech Connect

The study was undertaken to develop a method that would make direct measurements of acid gases, hydrogen sulfide and carbon dioxide, physical solubilities in aqueous alkanolamine solutions possible. Hydrogen sulfide and carbon dioxide physical solubilities in 20, 35, and 50% by weight diethanolamine aqueous solutions were measured. The solubility measurements were made at acid gas partial pressure up to 1000 psia and temperatures of 80, 150, 240 F. The solubility of nitrous oxide in water and in protonated diethanolamine solution was also determined at 80 F. A method that allows for direct measurements of acid gases physical solubilities has been developed. The method eliminates amines reactivity with acid gases by protonating the amines prior to their contact with acid gases. CO{sub 2} physical solubility in aqueous DEA solutions occurs mainly in the water portion of the solution. Therefore, the physical solubility of CO{sub 2} in an aqueous amine solution must be corrected based on the fraction of water in the solution. However, H{sub 2}S physical solubility in aqueous DEA solutions is the same as H{sub 2}S solubility in water. At any acid gas partial pressure, the physical solubility of H{sub 2}S is higher than that of CO{sub 2} for the same solution concentration and for the same temperature. This is also true for their solubilities is pure water. The ratio of CO{sub 2} to H{sub 2}S physical solubility to N{sub 2}O solubility in aqueous DEA solutions is not the same as their ratio in pure water.

Abu-Arabi, M.K.

1988-01-01

153

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

SciTech Connect

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.

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

1985-01-01

154

EBR-II Primary Tank Wash-Water Alternatives Evaluation  

SciTech Connect

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.

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

2008-05-01

155

Competitive adsorption of phenolic compounds from aqueous solution using sludge-based activated carbon.  

PubMed

Preparation of activated carbon from sewage sludge is a promising approach to produce cheap and efficient adsorbent for pollutants removal as well as to dispose of sewage sludge. The first objective of this study was to investigate the physical and chemical properties (BET surface area, ash and elemental content, surface functional groups by Boehm titration and weight loss by thermogravimetric analysis) of the sludge-based activated carbon (SBAC) so as to give a basic understanding of its structure and to compare to those of two commercial activated carbons, PICA S23 and F22. The second and main objective was to evaluate the performance of SBAC for single and competitive adsorption of four substituted phenols (p-nitrophenol, p-chlorophenol, p-hydroxy benzoic acid and phenol) from their aqueous solutions. The results indicated that, despite moderate micropore and mesopore surface areas, SBAC had remarkable adsorption capacity for phenols, though less than PICA carbons. Uptake of the phenolic compound was found to be dependent on both the porosity and surface chemistry of the carbons. Furthermore, the electronegativity and the hydrophobicity of the adsorbate have significant influence on the adsorption capacity. The Langmuir and Freundlich models were used for the mathematical description of the adsorption equilibrium for single-solute isotherms. Moreover, the Langmuir-Freundlich model gave satisfactory results for describing multicomponent system isotherms. The capacity of the studied activated carbons to adsorb phenols from a multi-solute system was in the following order: p-nitrophenol > p-chlorophenol > PHBA > phenol. PMID:21970174

Mohamed, E F; Andriantsiferana, C; Wilhelm, A M; Delmas, H

2011-01-01

156

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.

2013-07-23

157

Retention of silica nanoparticles on calcium carbonate sands immersed in electrolyte solutions.  

PubMed

Understanding nanoparticle-surface adhesion is necessary to develop inert tracers for subsurface applications. Here we show that nanoparticles with neutral surface charge may make the best subsurface tracers, and that it may be possible to used SiO2 nanoparticle retention to measure the fraction of solid surface that has positive charge. We show that silica nanoparticles dispersed in NaCl electrolyte solutions are increasingly retained in calcium carbonate (calcite) sand-packed columns as the solution ionic strength increases, but are not retained if they are injected in pure water or Na2SO4 electrolyte solutions. The particles retained in the NaCl experiments are released when the column is flushed with pure water or Na2SO4 solution. AFM measurements on calcite immersed in NaCl solutions show the initial repulsion of a silica colloidal probe as the surface is approached is reduced as the solution ionic strength increases, and that at high ionic strengths it disappears entirely and only attraction remains. These AFM measurements and their interpretation with Derjaguin-Landau-Verwey-Overbeek (DLVO) theory shows the calcite surface charge is always negative for Na2SO4 solutions, but changes from negative to positive in a patchy fashion as the ionic strength of the NaCl solution increases. Since mixed-charge (patchy) surfaces may be common in the subsurface, nanoparticles with near-zero charge may make the best tracers. PMID:25259754

Li, Yan Vivian; Cathles, Lawrence M

2014-12-15

158

Solution Deposition of Thin Carbon Coatings on LiFePO4.  

PubMed

We report the synthesis of ultrathin carbon coatings on polycrystalline LiFePO4 via solution deposition and subsequent annealing. The annealing temperature was systematically investigated with polymer systems on LiFePO4 nanostructures. The crystal structures, sizes, and morphologies were monitored and analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Micro-Raman and TEM were used to interrogate the carbon coatings after heat-treatments. Electrochemical performance of coated materials was investigated by cyclic voltammograms (CVs) and galvanostatic charge-discharge analysis. The olivine structured LiFePO4 remained stable up to 600 °C but underwent a rapid reduction reaction from LiFePO4 to Fe2P above 700 °C. The good compatibility between polyethylene glycol (PEG) and the surface of LiFePO4 enabled the formation of core-shell structure, which was transformed into a thin carbon coating on LiFePO4 after annealing. Both PEG and sucrose carbon-based sources yielded high-quality carbon coatings after annealing, as determined by the graphitic/disordered (G/D) ratios of 1.30 and 1.20, respectively. By producing more uniform and coherent coatings on LiFePO4 particles, batteries with significantly less carbon (i.e., 0.41 wt %) were fabricated and demonstrated comparable performance to traditionally synthesized carbon-coated LiFePO4 with higher carbon loadings (ca. 2.64 wt %). This will enable development of batteries with higher active material loading and therefore significantly larger energy densities. PMID:25387242

Zhu, Jianxin; Yoo, Kevin; El-Halees, Ibrahim; Kisailus, David

2014-12-10

159

Solubility of mixtures of hydrogen sulfide and carbon dioxide in aqueous N-methyldiethanolamine solutions  

SciTech Connect

Aqueous solutions of alkanolamines are commonly used to strip acid gases (H[sub 2]S and CO[sub 2]) from streams contaminated with these components. The two most widely used amines are monoethanolamine (MEA) and diethanolamine (DEA). The solubilities of mixtures of hydrogen sulfide and carbon dioxide in a 35 wt% (3.04 kmol/m[sup 3]) aqueous solution of N-methyldiethanolamine at 40 and 100C have been measured. Partial pressures of the acid gases ranged from 0.006 to 101 kPa at 40C and from 4 to 530 kPa at 100C.

Jou, Fang Yuan; Carroll, J.J.; Mather, A.E.; Otto, F.D. (Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Chemical Engineering)

1993-01-01

160

Removal of Lead (II) Ions from Aqueous Solutions onto Activated Carbon Derived from Waste Biomass  

PubMed Central

The removal of lead (II) ions from aqueous solutions was carried out using an activated carbon prepared from a waste biomass. The effects of various parameters such as pH, contact time, initial concentration of lead (II) ions, and temperature on the adsorption process were investigated. Energy Dispersive X-Ray Spectroscopy (EDS) analysis after adsorption reveals the accumulation of lead (II) ions onto activated carbon. The Langmuir and Freundlich isotherm models were applied to analyze equilibrium data. The maximum monolayer adsorption capacity of activated carbon was found to be 476.2?mg?g?1. The kinetic data were evaluated and the pseudo-second-order equation provided the best correlation. Thermodynamic parameters suggest that the adsorption process is endothermic and spontaneous. PMID:23853528

Erdem, Murat; Ucar, Suat; Karagöz, Selhan; Tay, Turgay

2013-01-01

161

Removal of lead from aqueous solutions on palm shell activated carbon.  

PubMed

The performance of a commercially available palm shell based activated carbon to remove lead ions from aqueous solutions by adsorption was evaluated. The adsorption experiments were carried out at pH 3.0 and 5.0. The effect of malonic and boric acid presence on the adsorption of lead ions was also studied. Palm shell activated carbon showed high adsorption capacity for lead ions, especially at pH 5 with an ultimate uptake of 95.2mg/g. This high uptake showed palm shell activated carbon as amongst the best adsorbents for lead ions. Boric acid presence did not affect significantly lead uptake, whereas malonic acid decreased it. The diffuse layer surface complexation model was applied to predict the extent of adsorption. The model prediction was found to be in concordance with the experimental values. PMID:16321520

Issabayeva, Gulnaziya; Aroua, Mohamed Kheireddine; Sulaiman, Nik Meriam Nik

2006-12-01

162

Depositional environment and reservoir characteristics of Middle Pennsylvanian Granite Wash, northern Palo Duro basin, Oldham County, Texas  

Microsoft Academic Search

The Lambert 1, Hryhor, and Sundance fields in Oldham County, Texas, produce oil from the Middle Pennsylvanian Canyon granite wash. Canyon granite wash conglomerates and sandstones have a maximum thickness of approximately 450 ft (140 m) and were derived from granitic rocks of the Bravo dome. The sediment was transported across carbonate platforms by streams and deposited into the Oldham

A. L. Vanderhill; R. R. Berg

1987-01-01

163

Mechanism of Pitting Corrosion Prevention by Nitrite in Carbon Steel Exposed to Dilute Salt Solutions  

SciTech Connect

The research has developed a broad fundamental understanding of the inhibition action of nitrite ions in preventing nitrate pitting corrosion of carbon steel tanks containing high-level radioactive waste. This fundamental understanding can be applied to specific situations during waste removal for permanent disposition and waste tank closure to ensure that the tanks are maintained safely. The results of the research provide the insight necessary to develop solutions that prevent further degradation.

Philip E. Zapp; John W. Van Zee

2002-02-01

164

Static lattice energy calculations of mixing and ordering enthalpy in binary carbonate solid solutions  

Microsoft Academic Search

Enthalpies of mixing and ordering in the binaries of the quaternary carbonate (Ca,Mg,Fe,Mn)CO3 solid solution have been modeled using static lattice energy minimization calculations. A set of self-consistent empirical potentials has been specially developed for this task. The calculations illustrate the importance of size mismatch in determining magnitudes of the enthalpies of mixing and ordering in the binaries. The enthalpy

Victor L. Vinograd; Björn Winkler; Andrew Putnis; Julian D. Gale; Marcel H. F. Sluiter

2006-01-01

165

Removal of Pb and Zn from the aqueous solutions by activated carbon prepared from Dates stone  

Microsoft Academic Search

The low-cost activated carbon prepared from Date stone, an agricultural solid waste by-product, were prepared by chemical activation with sulphuric acid for the removal of lead and zinc from aqueous solutions has been studied as a function of pH, contact time, metal concentrations and adsorbent concentrations. Adsorption equilibrium was reached after an equilibration time of 60 min and adsorption kinetics

Lotfi Mouni; Djoudi Merabet; Abdelkarim Bouzaza; Lazhar Belkhiri

2010-01-01

166

The electrochemical behaviour of polycrystalline nickel electrodes in different carbonate-bicarbonate ion-containing solutions  

Microsoft Academic Search

The dissolution and passivation of polycrystalline nickel in carbonate-bicarbonate ion-containing solutions covering wide ranges of pH and electrolyte concentration were investigated by employing voltammetric, galvanostatic and potentiostatic transient techniques. Results obtained with a rotating disc electrode allow the competing reactions related to the active-passive transition to be distinguished through the influence of the potential sweep rate and the rotation speed

A. E. Bohé; J. R. Vilche; A. J. Arvia

1990-01-01

167

Wash water waste pretreatment system  

NASA Technical Reports Server (NTRS)

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.

1977-01-01

168

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

PubMed

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

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

2006-06-30

169

Soil washing: A preliminary assessment of its applicability to Hanford  

SciTech Connect

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.

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

1991-09-01

170

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

PubMed

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

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

2012-12-01

171

Transport of Ions in Mesoporous Carbon Electrodes during Capacitive Deionization of High-Salinity Solutions.  

PubMed

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

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

172

DEVELOPING AN UNDERSTANDING OF WASHING MACHINE DYNAMICS  

Microsoft Academic Search

This report summarises the findings of one of the problems presented at the 2006 MISG. The problem, presented by Fisher and Paykel, was to develop a better un- derstanding of the dynamics of modern washing machines that use 'balance rings'. Balance rings are toroidal chambers that are partially filled with fluid. The wash- ing machine is a complicated system so

Clive Marsh; Steve Taylor; Paul Milliken; Galkadowite Senaratne

173

Fabrication of carbon nanotube high-frequency nanoelectronic biosensor for sensing in high ionic strength solutions.  

PubMed

The unique electronic properties and high surface-to-volume ratios of single-walled carbon nanotubes (SWNT) and semiconductor nanowires (NW) make them good candidates for high sensitivity biosensors. When a charged molecule binds to such a sensor surface, it alters the carrier density in the sensor, resulting in changes in its DC conductance. However, in an ionic solution a charged surface also attracts counter-ions from the solution, forming an electrical double layer (EDL). This EDL effectively screens off the charge, and in physiologically relevant conditions ~100 millimolar (mM), the characteristic charge screening length (Debye length) is less than a nanometer (nm). Thus, in high ionic strength solutions, charge based (DC) detection is fundamentally impeded. We overcome charge screening effects by detecting molecular dipoles rather than charges at high frequency, by operating carbon nanotube field effect transistors as high frequency mixers. At high frequencies, the AC drive force can no longer overcome the solution drag and the ions in solution do not have sufficient time to form the EDL. Further, frequency mixing technique allows us to operate at frequencies high enough to overcome ionic screening, and yet detect the sensing signals at lower frequencies. Also, the high transconductance of SWNT transistors provides an internal gain for the sensing signal, which obviates the need for external signal amplifier. Here, we describe the protocol to (a) fabricate SWNT transistors, (b) functionalize biomolecules to the nanotube, (c) design and stamp a poly-dimethylsiloxane (PDMS) micro-fluidic chamber onto the device, and (d) carry out high frequency sensing in different ionic strength solutions. PMID:23912795

Kulkarni, Girish S; Zhong, Zhaohui

2013-01-01

174

Oxygen isotope systematics in carbonate-water systems : influence of temperature, solution chemistry, and kinetic isotope fractionation.  

E-print Network

??The oxygen isotope fractionation between HCO3-/CO 32- and H2O was determined experimentally in order to elucidate the precipitation mechanisms of orthorhombic carbonate minerals in solutions.… (more)

Kim, Sang-Tae, 1970-

2006-01-01

175

Removal of mercury from aqueous solutions using activated carbon prepared from agricultural by-product/waste.  

PubMed

Removal of mercury from aqueous solutions using activated carbon prepared from Ceiba pentandra hulls, Phaseolus aureus hulls and Cicer arietinum waste was investigated. The influence of various parameters such as effect of pH, contact time, initial metal ion concentration and adsorbent dose for the removal of mercury was studied using a batch process. The experiments demonstrated that the adsorption process corresponds to the pseudo-second-order-kinetic models and the equilibrium adsorption data fit the Freundlich isotherm model well. The prepared adsorbents ACCPH, ACPAH and ACCAW had removal capacities of 25.88 mg/g, 23.66 mg/g and 22.88 mg/g, respectively, at an initial Hg(II) concentration of 40 mg/L. The order of Hg(II) removal capacities of these three adsorbents was ACCPH>ACPAH>ACCAW. The adsorption behavior of the activated carbon is explained on the basis of its chemical nature. The feasibility of regeneration of spent activated carbon adsorbents for recovery of Hg(II) and reuse of the adsorbent was determined using HCl solution. PMID:18313830

Rao, M Madhava; Reddy, D H K Kumar; Venkateswarlu, Padala; Seshaiah, K

2009-01-01

176

On the use of vinylene carbonate (VC) as an additive to electrolyte solutions for Li-ion batteries  

Microsoft Academic Search

Vinylene carbonate (VC) was tested as an additive to electrolyte solutions for Li-ion batteries. For the model electrodes, synthetic graphite was chosen as the anode material, while LiMn2O4 spinel and LiNiO2 were chosen as the cathode materials. The test solution was 1 M LiAsF6 in a 1:1 mixture of ethylene and dimethyl carbonates (EC–DMC). Cyclic voltammetry (CV), chronopotentiometry, impedance spectroscopy,

D Aurbach; K Gamolsky; B Markovsky; Y Gofer; M Schmidt; U Heider

2002-01-01

177

Removal of Cu and Ag from aqueous solution on a chemically-carbonized sorbent from date palm leaflets  

Microsoft Academic Search

A chemically-carbonized sorbent was prepared from date palm leaflets by sulphuric acid treatment at 170°C. Carbonization took place via the dehydration effect of the hot sulphuric acid producing a carbon with reduction property. Sorption of Cu and Ag from aqueous solution was investigated in terms of pH, contact time, metal concentration and temperature. A peculiar behaviour was found for the

El-Said Ibrahim El-Shafey; Salma Muhammed Zahran Al-Kindy

2012-01-01

178

Adsorption of Reactive Red M-2BE dye from water solutions by multi-walled carbon nanotubes and activated carbon.  

PubMed

Multi-walled carbon nanotubes and powdered activated carbon were used as adsorbents for the successful removal of Reactive Red M-2BE textile dye from aqueous solutions. The adsorbents were characterised by infrared spectroscopy, N(2) adsorption/desorption isotherms and scanning electron microscopy. The effects of pH, shaking time and temperature on adsorption capacity were studied. In the acidic pH region (pH 2.0), the adsorption of the dye was favourable using both adsorbents. The contact time to obtain equilibrium at 298K was fixed at 1h for both adsorbents. The activation energy of the adsorption process was evaluated from 298 to 323K for both adsorbents. The Avrami fractional-order kinetic model provided the best fit to the experimental data compared with pseudo-first-order or pseudo-second-order kinetic adsorption models. For Reactive Red M-2BE dye, the equilibrium data were best fitted to the Liu isotherm model. Simulated dyehouse effluents were used to check the applicability of the proposed adsorbents for effluent treatment. PMID:21724329

Machado, Fernando M; Bergmann, Carlos P; Fernandes, Thais H M; Lima, Eder C; Royer, Betina; Calvete, Tatiana; Fagan, Solange B

2011-09-15

179

Contaminant resorption during soil washing  

SciTech Connect

To evaluate the applicability of soil washing to a specific site requires some basic research in how contaminants are bound. Much can be learned from sequential extraction methodology based on micronutrient bioavailability studies wherein the soil matrix is chemically dissected to selectively remove particular fixation mechanisms independently. This procedure uses a series of progressively more aggressive solvents to dissolve the principle phases that make up a soil, however, the published studies do not appear to consider the potential for a contaminant released from one type of site to resorb on another site during an extraction. This physical model assumes no ion exchange or adsorption at sites either previously occupied by other ions, or exposed by the dissolution. Therefore, to make engineering use of the sequential extraction data, the release of contamination must be evaluated relative to the effects of resorption. Time release studies were conducted to determine the optimum duration for extraction to maximize complete destruction of the target matrix fraction while minimizing contaminant resorption. Tests with and without a potassium brine present to inhibit cesium resorption indicated extraction efficiency could be enhanced by as much as a factor of ten using the brine.

Gombert, D.

1993-10-01

180

Well washing tool and method  

SciTech Connect

A well washing tool comprises a tubular mandrel; first and second packer assemblies carried on the mandrel at opposite ends thereof; an outer tubular body surrounding the mandrel between the packer assemblies; an annular chamber between the mandrel and the surrounding tubular body; and a valve assembly carried within the annular chamber. The tubular mandrel is adapted for connecting the tool in a pipe string extending to the surface of the well and the lower end may be adapted for blocking the flow of fluids from the pipe string through the mandrel flow passage. Ports are provided in the walls of the mandrel and the tubular body permitting fluid communication between the mandrel flow passage and the exterior of the tool. The valve assembly prevents the fluid communication by blocking one or more of the ports. The packer assemblies are actuated by a predetermined pressure and the valve assembly is responsive to a higher predetermined pressure to unblock the ports permitting fluid communication between the mandrel flow passage and the exterior of the tool through the annular chamber. 19 claims.

Weitz, R.D.

1981-07-21

181

Well washing tool and method  

SciTech Connect

A well washing tool which may comprise: a tubular mandrel; first and second packer assemblies carried on the mandrel at opposite ends thereof; an outer tubular body surrounding the mandrel between the packer assemblies; an annular chamber between the mandrel and the surrounding tubular body; and a valve assembly carried within the annular chamber. The tubular mandrel is adapted for connecting the tool in a pipe string extending to the surface of the well and the lower end may be adapted for blocking flow of fluids from the pipe string through the mandrel flow passage. Ports are provided in the walls of the mandrel and the tubular body permitting fluid communication between the mandrel flow passage and the exterior of the tool. The valve assembly prevents such fluid communication by blocking one or more of the ports. The packer assemblies are actuated by a predetermined pressure and the valve assembly is responsive to a higher predetermined pressure to unblock the ports permitting fluid communication between the mandrel flow passage and the exterior of the tool through the annular chamber.

Weitz, R. D.

1985-03-05

182

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

PubMed

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

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

2014-01-01

183

The removal of uranium (VI) from aqueous solutions onto activated carbon developed from grinded used tire.  

PubMed

In this study, activated carbon was prepared from waste tire by KOH chemical activation. The pore properties including the BET surface area, pore volume, pore size distribution, and average pore diameter were characterized. BET surface area of the activated carbon was determined as 558 m(2)/g. The adsorption of uranium ions from the aqueous solution using this activated carbon has been investigated. Various physico-chemical parameters such as pH, initial metal ion concentration, and adsorbent dosage level and equilibrium contact time were studied by a batch method. The optimum pH for adsorption was found to be 3. The removal efficiency has also been determined for the adsorption system as a function of initial concentration. The experimental results were fitted to Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm models. A comparison of best-fitting was performed using the coefficient of correlation and the Langmuir isotherm was found to well represent the measured sorption data. According to the evaluation using the Langmuir equation, the saturated monolayer sorption capacity of uranium ions onto waste tire activated carbon was 158.73 mg/g. The thermodynamic equilibrium constant and the Gibbs free energy were determined and results indicated the spontaneous nature of the adsorption process. Kinetics data were best described by pseudo-second-order model. PMID:23821251

Belgacem, Ahmed; Rebiai, Rachid; Hadoun, Hocine; Khemaissia, Sihem; Belmedani, Mohamed

2014-01-01

184

Effect of carbon on formation of mixed solid solutions during mechanochemical synthesis of Ni-Al-Mo-C mixtures and ordering of solutions during heating  

NASA Astrophysics Data System (ADS)

Solid solutions Ni(Al, Mo, C) are formed via milling the Ni2.8Al1Mo0.2 and Ni3Al0.8Mo0.2 and graphite-containing Ni2.8Al1Mo0.2C(0.25, 0.5) and Ni3Al0.8Mo0.2C(0.25, 0.5) mixtures. In this case, some amount of Mo remains beyond the solid solution. Graphite added to a starting mixture decreases the Mo solubility and favors the amorphization of solid solutions. The complete amorphization was found for the mixture with the 5 at % C and 5 at % Mo, which was added instead of Ni. The heating of mechanically synthesized (MS) powder alloys leads to the ordering of carbon-free and carbon-containing solid solutions with the formation of the L12 and E21 structure, respectively. In the course of the ordering of the Ni(Al, Mo, C) solid solutions, Mo and carbon precipitate in the form of the molybdenum carbide (Mo2C) second phase. The hardness of the MS three-phase Ni-Al-Mo-C solid solutions subjected to hot isostatic pressing is determined by the mass fraction of the formed Mo2C carbide. It is shown that the carbon content in the multicomponent antiperovskite can be estimated by analyzing the ratio of integral intensities of superlattice reflections I (100)/ I (110).

Portnoi, V. K.; Leonov, A. V.; Streletskii, A. N.; Logacheva, A. I.

2014-03-01

185

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

NASA Astrophysics Data System (ADS)

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.

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

2008-12-01

186

Computer Simulation of Cascade Damage in ?-Iron with Carbon in Solution  

SciTech Connect

Molecular dynamics simulation method is used to investigate defect production by displacement cascades in iron with carbon (C) in solution. This is the first study of cascade damage in a metal containing interstitial solute. Iron is of particular interest because of the use of ferritic steels in plant for nuclear power generation. Cascades are simulated with energy in the range 5 to 20keV in iron at either 100 or 600K containing carbon with concentration in the range 0 to 1at%. C in solution has no discernible effect on the number of defects produced in cascades under any of the conditions simulated, nor on the clustered fraction of either self-interstitial atoms (SIAs) or vacancies. However, significant fractions of single SIAs and vacancies are trapped by C in the cascade process, irrespective of cascade energy. The fraction is independent of temperature for vacancies, but increases strongly with temperature for SIAs: this is a consequence of the higher mobility of the SIA.

Andrew, Calder F [University of Liverpool; Bacon, David J [University of Liverpool; Barashev, Aleksandr [University of Liverpool; Osetskiy, Yury N [ORNL

2008-01-01

187

Computer simulation of cascade damage in ?-iron with carbon in solution  

NASA Astrophysics Data System (ADS)

Molecular dynamics simulation method is used to investigate defect production by displacement cascades in iron with carbon (C) in solution. This is the first study of cascade damage in a metal containing interstitial solute. Iron is of particular interest because of the use of ferritic steels in plant for nuclear power generation. Cascades are simulated with energy in the range 5-20 keV in iron at either 100 or 600 K containing carbon with concentration in the range 0-1 at.%. C in solution has no discernible effect on the number of defects produced in cascades under any of the conditions simulated, nor on the clustered fraction of either self-interstitial atoms (SIAs) or vacancies. However, significant fractions of single SIAs and vacancies are trapped by C in the cascade process, irrespective of cascade energy. The fraction is independent of temperature for vacancies, but increases strongly with temperature for SIAs: this is a consequence of the higher mobility of the SIA.

Calder, Andrew F.; Bacon, David J.; Barashev, Alexander V.; Osetsky, Yuri N.

2008-12-01

188

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

PubMed Central

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

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

189

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

PubMed

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

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

2014-09-16

190

Carbonized material adsorbents for the removal of mercury from aqueous solutions  

SciTech Connect

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.

NONE

1996-10-01

191

30 CFR 206.258 - Washing allowances-general.  

Code of Federal Regulations, 2010 CFR

...REVENUE MANAGEMENT PRODUCT VALUATION Federal Coal § 206.258 Washing allowances—general. (a) For ad...marketable condition shall be allowed as a cost of washing. (e) Coal washing costs shall only be recognized as...

2010-07-01

192

30 CFR 206.457 - Washing allowances-general.  

Code of Federal Regulations, 2010 CFR

...REVENUE MANAGEMENT PRODUCT VALUATION Indian Coal § 206.457 Washing allowances—general. (a) For ad...marketable condition shall be allowed as a cost of washing. (e) Coal washing costs shall only be recognized as...

2010-07-01

193

30 CFR 206.458 - Determination of washing allowances.  

Code of Federal Regulations, 2010 CFR

...completed page one of Form MMS-4292, Coal Washing Allowance Report, in accordance...previous reporting period. If coal washing is continuing, the lessee shall...next calendar year. The estimated coal washing allowance shall be based on...

2010-07-01

194

Synthesis of finely divided molybdenum sulfide nanoparticles in propylene carbonate solution  

NASA Astrophysics Data System (ADS)

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.

Afanasiev, Pavel

2014-05-01

195

Carbon dioxide removal from flue gases by absorption/ desorption in aqueous diethanolamine solutions.  

PubMed

The carbon dioxide (CO2) desorption rate from CO2- loaded aqueous diethanolamine (DEA) solutions was measured using a stirred cell with a flat gas-liquid interface. The measurements were performed in the temperature range of 293.15-313.15 K and an amine concentration range of 10-20% mass DEA. Measurements were based on a semibatch isothermal absorption of the gas until the equilibrium state was reached, followed by desorption, which was initiated by the pressure release in the system. A simplified mass transfer model based on the film theory coupled with CO2, mass balance was developed to interpret the experimental data. On the basis of the proposed model, the initial mass transfer rates were calculated from the experimental results. The calculated initial desorption rates enabled estimation of the enhancement factor for CO2 mass transfer from aqueous DEA solutions. Analysis of the experimental data showed that desorption took place in the diffusive mass transfer regime. PMID:20842932

Kierzkowska-Pawlak, Hanna; Chacuk, Andrzej

2010-08-01

196

Electronic separation of dispersed carbon nanotubes in solution by Lorentz forces  

NASA Astrophysics Data System (ADS)

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 a non-uniform voltage waveform. This waveform generates a magnetic field that couples more strongly with metallic SWNTs than semiconducting SWNTs, due to a higher metallic SWNT magnetic moment, separating the tubes by Lorentz force. By conducting SWNT spectrophotometric measurements in the UV-vis-IR region, we assess the separation effectiveness. From the extracted supernatant solution, we observe a multi-fold absorbance enhancement in the metallic SWNT transition regions [1]. Additionally, the small full-width at half maximum in the absorbance peaks suggests that we are selecting a small number of metallic chiralities in our separation.[4pt] [1] Ausman et al., J. Phys. Chem. B. 104, 8911 (2000).

Subbaiah, Charishma; Wood, Joshua; Lyding, Joseph

2011-03-01

197

Active and passive behavior of sintered iron in ammoniacal ammonium carbonate solution  

NASA Astrophysics Data System (ADS)

The anodic dissolution behavior of sintered iron in ammoniacal ammonium carbonate solution (pH = 9.7) has been investigated with the aid of electrochemical techniques. Surface films formed on bulk iron during air exposure or immersion in the ammoniacal solution were characterized by using X-ray photoelectron spectroscopy (XPS). Immersion in the ammoniacal solution gave an apparent open circuit potential (OCP) in the range of E = 0.04 to 0.09 V, standard hydrogen electrode (SHE); at these potentials, no dissolution of Fe was detected. Potential transients obtained during cathodic reactivation and the XPS results suggest that an air-formed oxide of Fe3O4 is responsible for this behavior. The anodic polarization behavior of sintered Fe was similar to that of bulk Fe, showing active, passive, and oxygen evolution regions. A very high current density observed in the passive region for some sintered specimens was attributable to active dissolution within the pore structure, analogous to conditions during crevice corrosion. The presence of oxygen in the solution stabilized both the passive film and the more noble apparent OCP.

Kim, H. S.; Kho, Y. T.; Osseo-Asare, K.; Pickering, H. W.

1991-06-01

198

Wash water waste pretreatment system study  

NASA Technical Reports Server (NTRS)

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.

1976-01-01

199

21 CFR 1250.87 - Wash water.  

Code of Federal Regulations, 2012 CFR

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Sanitation Facilities and Conditions on Vessels § 1250.87 Wash water. Where systems installed on vessels for...

2012-04-01

200

21 CFR 1250.87 - Wash water.  

Code of Federal Regulations, 2011 CFR

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Sanitation Facilities and Conditions on Vessels § 1250.87 Wash water. Where systems installed on vessels for...

2011-04-01

201

21 CFR 1250.87 - Wash water.  

Code of Federal Regulations, 2014 CFR

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Sanitation Facilities and Conditions on Vessels § 1250.87 Wash water. Where systems installed on vessels for...

2014-04-01

202

21 CFR 1250.87 - Wash water.  

Code of Federal Regulations, 2013 CFR

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Sanitation Facilities and Conditions on Vessels § 1250.87 Wash water. Where systems installed on vessels for...

2013-04-01

203

21 CFR 1250.87 - Wash water.  

Code of Federal Regulations, 2010 CFR

...REGULATIONS UNDER CERTAIN OTHER ACTS ADMINISTERED BY THE FOOD AND DRUG ADMINISTRATION INTERSTATE CONVEYANCE SANITATION Sanitation Facilities and Conditions on Vessels § 1250.87 Wash water. Where systems installed on vessels for...

2010-04-01

204

Characterization of platinum catalyst supported on carbon nanoballs prepared by solution plasma processing  

SciTech Connect

In order to improve the energy-conversion efficiency in fuel cells, the authors loaded Pt nanoparticles on carbon nanoballs (CNBs) by using solution plasma processing (SPP) involving CNB and Pt ion with a protection group. In this study, we employed poly(vinylpyrrolidone) (PVP) or sodium dodecyl sulfate (SDS) to prepare Pt nanoparticles supported on CNB (Pt/CNB) by the SPP, and the electrochemical properties as a catalyst was evaluated by cyclic voltammetry. The carbon nanoballs were prepared by thermal decomposition process of ethylene and hydrogen gases. Color of the solution changed from yellow to dark brown as synthesis time. This change indicates the improvement of dispersibility of CNB. Moreover, transmission electron microscopy images and elemental mapping images showed the Pt nanoparticles supported on CNB. A catalytic activity of the Pt/CNB in use of SDS was shown to be higher than the Pt/CNB prepared with PVP system. The SDS-containing Pt/CNB also showed the higher activity than that obtained by the conventional method.

Ichin, Yoshimichi; Mitamura, Koji; Saito, Nagahiro; Takai, Osamu [Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603 (Japan); EcoTopia Science Institute, Nagoya University, Nagoya 464-8603 (Japan); CREST/JST, Nagoya 464-8603 (Japan) and Department of Molecular Design and Engineering, Nagoya University, Nagoya 464-8603 (Japan); Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603 (Japan) and CREST/JST, Nagoya 464-8603 (Japan); Department of Materials, Physics and Energy Engineering, Nagoya University, Nagoya 464-8603 (Japan); EcoTopia Science Institute, Nagoya University, Nagoya 464-8603 (Japan) and CREST/JST, Nagoya 464-8603 (Japan)

2009-07-15

205

Mercury removal from aqueous solution and flue gas by adsorption on activated carbon fibres  

NASA Astrophysics Data System (ADS)

The use of two activated carbon fibres, one laboratorial sample prepared from a commercial acrylic textile fibre and one commercial sample of Kynol ®, as prepared/received and modified by reaction with powdered sulfur and H 2S gas in order to increase the sulfur content were studied for the removal of mercury from aqueous solution and from flue gases from a fluidized bed combustor. The sulfur introduced ranged from 1 to 6 wt.% depending on the method used. The most important parameter for the mercury uptake is the type of sulfur introduced rather than the total amount and it was found that the H 2S treatment of ACF leads to samples with the highest mercury uptake, despite the lower sulfur amount introduced. The modified samples by both methods can remove HgCl 2 from aqueous solutions at pH 6 within the range 290-710 mg/g (ACF) which can be favourably compared with other studies already published. The use of a filter made with an activated carbon fibre modified by powdered sulfur totally removed the mercury species present in the flue gases produced by combustion of fossil fuel.

Nabais, João Valente; Carrott, P. J. M.; Carrott, M. M. L. Ribeiro; Belchior, Marisa; Boavida, Dulce; Diall, Tatiana; Gulyurtlu, Ibrahim

2006-06-01

206

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

207

Utilization of washed MSWI fly ash as partial cement substitute with the addition of dithiocarbamic chelate.  

PubMed

The management of the big amount of fly ash as hazardous waste from the municipal solid waste incinerator (MSWI) has encountered many problems in China. In this study, a feasibility research on MSWI fly ash utilization as partial cement substitute in cement mortars was therefore carried out. MSWI fly ash was subjected to washing process to reduce its chlorine content (from 10.16% to 1.28%). Consequently, it was used in cement mortars. Ten percent and 20% replacement of cement by washed ash showed acceptable strength properties. In TCLP and 180-day monolithic tests, the mortars with washed ash presented a little stronger heavy metal leachability, but this fell to the blank level (mortar without washed ash) with the addition of 0.25% chelate. Therefore, this method is proposed as an environment-friendly technology to achieve a satisfactory solution for MSWI fly ash management. PMID:17466440

Gao, Xingbao; Wang, Wei; Ye, Tunmin; Wang, Feng; Lan, Yuxin

2008-07-01

208

Highly selective adsorption of methanol in carbon nanotubes immersed in methanol-water solution  

NASA Astrophysics Data System (ADS)

The systems of open-ended carbon nanotubes (CNTs) immersed in methanol-water solution are studied by molecular dynamics simulations. For the (6,6) CNT, nearly pure methanol is found to preferentially occupy interior space of the CNT. Even when the mass fraction (MF) of methanol in bulk solution is as low as 1%, the methanol MF within the CNT is still more than 90%. For CNTs with larger diameters, the methanol concentrations within CNTs are also much higher than those outside CNTs. The methanol selectivity decreases with increasing CNT diameter, but not monotonically. From microscopic structural analyses, we find that the primary reason for the high selectivity of methanol by CNTs lies on high preference of methanol in the first solvation shell near the inner wall of CNT, which stems from a synergy effect of the van der Waals interaction between CNT and the methyl groups of methanol, together with the hydrogen bonding interaction among the liquid molecules. This synergy effect may be of general significance and extended to other systems, such as ethanol aqueous solution and methanol/ethanol mixture. The selective adsorption of methanol over water in CNTs may find applications in separation of water and methanol, detection of methanol, and preservation of methanol purity in fuel cells.

Zhao, Wen-Hui; Shang, Bo; Du, Sheng-Ping; Yuan, Lan-Feng; Yang, Jinlong; Cheng Zeng, Xiao

2012-07-01

209

Solution assembly of organized carbon nanotube networks for thin-film transistors.  

PubMed

Ultrathin, transparent electronic materials consisting of solution-assembled nanomaterials that are directly integrated as thin-film transistors or conductive sheets may enable many new device structures. Applications ranging from disposable autonomous sensors to flexible, large-area displays and solar cells can dramatically expand the electronics market. With a practical, reliable method for controlling their electronic properties through solution assembly, submonolayer films of aligned single-walled carbon nanotubes (SWNTs) may provide a promising alternative for large-area, flexible electronics. Here, we report SWNT network TFTs (SWNTntTFTs) deposited from solution with controllable topology, on/off ratios averaging greater than 10(5), and an apparent mobility averaging 2 cm(2)/V.s, without any pre- or postprocessing steps. We employ a spin-assembly technique that results in chirality enrichment along with tunable alignment and density of the SWNTs by balancing the hydrodynamic force (spin rate) with the surface interaction force controlled by a chemically functionalized interface. This directed nanoscale assembly results in enriched semiconducting nanotubes yielding excellent TFT characteristics, which is corroborated with mu-Raman spectroscopy. Importantly, insight into the electronic properties of these SWNT networks as a function of topology is obtained. PMID:19924882

Lemieux, Melburne C; Sok, Seihout; Roberts, Mark E; Opatkiewicz, Justin P; Liu, Derrick; Barman, Soumendra N; Patil, Nishant; Mitra, Subhasish; Bao, Zhenan

2009-12-22

210

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

SciTech Connect

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.

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

1992-02-01

211

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

NASA Technical Reports Server (NTRS)

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.

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

1974-01-01

212

Wash water reclamation technology for advanced manned spacecraft  

NASA Technical Reports Server (NTRS)

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.

Putnam, D. F.

1977-01-01

213

Microbial decolorization and bioremediation of melanoidin containing molasses spent wash.  

PubMed

Molasses spent wash from cane-molasses based distilleries contains a brown coloured recalcitrantpolymer melanoidin, which if disposed untreated poses a great threat to environment. Microbial decolorization and chemical oxygen demand (COD) reduction was found to be dependent on specific carbon and nitrogen source. Under optimal condition of pH, carbon and nitrogen concentration for each treatment, it was found that Bacillus sp isolated from soil was capable of removing COD (85. 35%) and colour (81.10%) from distillery waste to the maximum extent after 9 days atpH 7 in the medium containing 0.5% peptone, 2% glucose and 10% (v/v), followed by Phanerochaete chrysosporium and lowest reduction was obtained by using native microbial consortium. PMID:18380094

Singh, K D; Sharma, S; Dwivedi, A; Pandey, P; Thakur, R L; Kumar, V

2007-07-01

214

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

215

Adsorptive removal of congo red dye from aqueous solution using bael shell carbon  

NASA Astrophysics Data System (ADS)

This study investigates the potential use of bael shell carbon (BSC) as an adsorbent for the removal of congo red (CR) dye from aqueous solution. The effect of various operational parameters such as contact time, temperature, pH, and dye concentration were studied. The adsorption kinetics was modeled by first-order reversible kinetics, pseudo-first-order kinetics, and pseudo-second-order kinetics. The dye uptake process obeyed the pseudo-second-order kinetic expression at pH 5.7, 7 and 8 whereas the pseudo-first-order kinetic model was fitted well at pH 9. Langmuir, Freundlich and Temkin adsorption models were applied to fit adsorption equilibrium data. The best-fitted data was obtained with the Freundlich model. Thermodynamic study showed that adsorption of CR onto BSC was endothermic in nature and favorable with the positive ? H° value of 13.613 kJ/mol.

Ahmad, Rais; Kumar, Rajeev

2010-12-01

216

Is Integrated Gasification Combined Cycle with Carbon Capture-Storage the Solution for Conventional Coal Power Plants  

E-print Network

to IGCC plants than to PC plants. According to a study (Francis, Grodon, Hanniman & Rhodes –COWS 2007), building and operating a SCPC plant in a carbon-regulated environment costs $10 per MW-hour more if there are no restrictions on carbon emissions... projects currently employing this method of carbon storage are in Sleipner, Norway and In Salah, Algeria. IS IGCC with CCS the Solution for Conventional Coal Power Plants – EMGT 860 Student I.D. 2376172 36 ? Enhanced coal bed methane recovery...

Kundi, Manish

2011-12-16

217

Theoretical study of the dimerization of calcium carbonate in aqueous solution under natural water conditions  

NASA Astrophysics Data System (ADS)

First principles calculations have been used to investigate the condensation reactions of hydrated calcium bicarbonate monomers in a simulated aqueous environment. The reaction pathway for the calcium bicarbonate dimerization process has been computed at the density functional theory-PBE level with the COSMO dielectric continuum model to simulate the hydrated environment. The results indicate that calcium bicarbonate dimers form via an associative mechanism: the first step involves a sevenfold calcium bicarbonate intermediate followed by the loss of one water molecule from the first coordination shell of calcium. Both steps are characterised by a low energy barrier of approximately 2 kcal mol -1, suggesting that the dimerization process is not kinetically hindered in aqueous solution. However, the Gibbs free energies for the condensation reactions to form the calcium bicarbonate dimers and the species Ca(HCO 3) 2(H 2O) 4, Ca(HCO 3) 3(H 2O) 3- and Ca 2(HCO 3)(H 2O) 103+, computed using the PBE and mPW1B95 density functional theory levels for the gas-phase component and the UAHF-CPCM solvation model for the hydration contribution, are all positive, which indicates that the formation of these early calcium bicarbonate clusters is thermodynamically unfavourable in aqueous solutions. Our calculations therefore suggest that the oligomerization of calcium carbonate is not spontaneous in water, at the conditions considered in our simulations, i.e. T = 298 K and neutral pH, which indicates that the nucleation of calcium carbonate cannot occur through a homogeneous process when calcium-bicarbonate ion pairs are the major source of CaCO 3 in the aqueous environment.

Di Tommaso, Devis; de Leeuw, Nora H.

2009-09-01

218

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

PubMed Central

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

Petersen, Richard C.

2014-01-01

219

Hybrid multiwalled carbon nanotube--Laponite sorbent for removal of methylene blue from aqueous solutions.  

PubMed

The article discusses adsorption of methylene blue dye by novel hybrid sorbent consisting of Laponite and multiwalled carbon nanotubes. The sorbent was obtained by sonication of the aqueous suspensions of nanotubes at different concentrations of Laponite. The methods of the methylene blue adsorption, dead-end membrane filtration and environmental scanning electron microscopy were used for the sorbent characterization. It may be concluded from the results of filtration and adsorption experiments that sonication of mixed aqueous suspensions of Laponite and multiwalled carbon nanotubes leads to the formation of hybrid particles (ML-particles) with a core-shell structure. The size and the shape of hybrid particles were determined by nanotubes, while their adsorption properties were determined by Laponite particles attached to the surface of nanotubes. The Laponite content in hybrid particles was corresponding to the Laponite to nanotubes ratio in the initial suspension X(L)=0-1. Due to the presence of Laponite in the sorbent, its adsorbing capacity was much higher as compared to the adsorbing capacity of pure nanotubes, and it was directly proportional to the Laponite content. This sorbent may be used either as a purifying additive or as a filtering layer if it is deposited on the surface of a supporting membrane. Due to relatively large size of hybrid particles, they can be easily separated from the purified solution by filtration or centrifugation. PMID:25052299

Loginov, Maksym; Lebovka, Nikolai; Vorobiev, Eugene

2014-10-01

220

Carbonic anhydrase-inhibitor binding: From solution to the gas phase  

SciTech Connect

In this report, we compare the kinetic stabilities of noncovalent complexes between bovine carbonic anhydrase II(BCAII, EC 4.2.1.1) and para-substituted benzenesulfonamide inhibitors in the gas phase and in solution. These BCAII-inhibitor systems are attractive model systems due to the stability of carbonic anhydrase (CA) and its well characterized structure and ligand complexes, providing a basis for inferences regarding the protein structure in the gas phase and its ligand interactions. CA is a roughly spherical Zn(II) metalloenzyme having a conical binding pocket which catalyzes the hydration of CO{sub 2} to bicarbonate. A large body of data correlate structures of sulfonamide ligands with their binding constants to CA. A set of eight inhibitors was selected for this study, covering a wide range of binding affinities and varying in the length of their tails and aromatic content. The results demonstrate that relative stabilities of BCAII-inhibitor complexes differ substantially between the gas and liquid phases and also show the dominant role of polar surface interactions in the gas phase. 12 refs., 1 fig., 1 tab.

Wu, Q.; Bruce, J.E.; Smith, R.D. [Pacific Northwest National Lab., Richland, WA (United States)] [Pacific Northwest National Lab., Richland, WA (United States); Gao, J.; Joseph-McCarthy, D.; Sigal, G.B.; Whitesides, G.M. [Harvard Univ., Cambridge, MA (United States)] [Harvard Univ., Cambridge, MA (United States)

1997-02-05

221

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

SciTech Connect

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.

Goni, S.; Guerrero, A

2003-01-01

222

Wash solvent reuse in paint production  

SciTech Connect

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.

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

1994-04-01

223

Comparison of Adsorption Capacity of p-Cresol & pNitrophenol by Activated Carbon in Single and Double Solute  

Microsoft Academic Search

Adsorption of p-Cresol and p-Nitrophenol by untreated activated carbon in single and multisolute solutions was carried out at 301 K and at controlled pH conditions. In acidic conditions, well below the pKa of both solutes, it was observed that the adsorbate solubility and the electron density of aromatic rings influenced the extent of adsorption by affecting the extent of London

Sirous Nouri; Fouad Haghseresht; G. Q. Max Lu

2002-01-01

224

Adsorption of p-nitrophenol from aqueous solutions onto activated carbon fiber.  

PubMed

The adsorption of p-nitrophenol (PNP) onto activated carbon fiber (ACF) was investigated in simulated wastewater in a batch system to evaluate the effects of solution pH, presence of sodium chloride, adsorbent doses and temperature. It was found that PNP adsorption amount depended on pH, sodium chloride content, adsorbent doses and temperature. Langmuir and Freundlich models were applied to describe the adsorption isotherms. Freundlich model agreed with experimental data well, indicating the possibility of more than just one monomolecular layer of coverage. SEM photographs of ACF before and after adsorption revealed that it was in part with multimolecular layers of coverage on ACF surfaces. The change of free energy, enthalpy, and entropy of adsorption were also evaluated for the adsorption process. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data. The experimental data fitted very well the pseudo-second-order kinetic model. Attempts were made to desorb PNP from ACF using dilute NaOH solution and water, and desorption efficiency was obtained to the extent of 92.7% with 0.025 M NaOH and water at 368 K. PMID:17030422

Tang, Dengyong; Zheng, Zheng; Lin, Kui; Luan, Jingfei; Zhang, Jibiao

2007-05-01

225

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

PubMed Central

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

2014-01-01

226

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

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

227

Analytical solution of geological carbon sequestration under constant pressure injection into a horizontal radial reservoir  

NASA Astrophysics Data System (ADS)

Carbon capture and sequestration (CCS) is believed to be an economically feasible technology to mitigate global warming by capturing carbon dioxide (CO2), the major component of greenhouse gases, from the atmosphere and injecting it into deep geological formations.Several mechanisms can help trap CO2 in the pore space of a geological reservoir, stratigraphic and structural trapping, hydrodynamic trapping, and geochemical trapping.Besides these trapping mechanisms, another important issue that deserves careful attention is the risk of CO2 leakage. The common ';constant injection rate' scenario may induce high pressure buildup that will endanger the mechanical integrity as well as the sealing capability of the cap rock. Instead of injecting CO2 at a constant mass rate, CO2 can be injected into the reservoir by fixing the pressure (usually the bottom-hole pressure) in the injection borehole. By doing so, the inevitable pressure buildup associated with the constant injection scheme can be completely eliminated in the constant pressure injection scheme. In this paper, a semi-analytical solution for CO2 injection with constant pressure was developed. For simplicity, structural and geochemical trapping mechanisms were not considered. Therefore, a horizontal reservoir with infinite radial extent was considered. Prior to injection, the reservoir is fully saturated with the formation brine. It is assumed that CO2 does not mix with brine such that a sharp interface is formed once CO2 invades the brine-saturated pores. Because of the density difference between CO2 and brine, CO2 resides above the interface. Additional assumptions were also made when building up the brine and CO2 mass balance equations: (1) both of the fluids and the geological formations are incompressible, (2) capillary pressure is neglected, (3)there is no fluid flow in the vertical direction, and the horizontal flow satisfies the Darcy's law.In order to solve for the height of brine-CO2 interface, the two mass balance equations are combined into a single one by using a similarity transformation such that the two independent variables (radial distance and time) are reduced into only one similarity variable. The resulting mass balance equation is recast as a second-order ordinary differential equation, which can be treated as an initial value problem and solved conveniently by MATLAB. We have tested this solution using one hypothetical parameter set. In the next step, we will verify this analytical solution by conducting a parallel numerical simulation using TOUGH2 ECO2N. Then, characteristics of the CO2 front will be studied and compared with the Buckley-Leverett theory.

Jhang, R.; Liou, T.

2013-12-01

228

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

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

229

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

Microsoft Academic Search

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

C. Riordan; A. P. McHale

1998-01-01

230

Adsorption from aqueous solutions on opened carbon nanotubes--organic compounds speed up delivery of water from inside.  

PubMed

We report the results of first systematic studies of organic adsorption from aqueous solutions onto relatively long single walled carbon nanotubes (four tubes, in initial and oxidised forms). Using molecular dynamics simulations (GROMACS package) we discuss the behaviour of tube-water as well as tube-adsorbate systems, for three different adsorbates (benzene, phenol and paracetamol). PMID:19830315

Terzyk, Artur P; Gauden, Piotr A; Furmaniak, Sylwester; Weso?owski, Rados?aw P; Harris, Peter J F; Kowalczyk, Piotr

2009-11-01

231

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

USGS Publications Warehouse

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.

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

1971-01-01

232

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

SciTech Connect

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.

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

233

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)

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.

Solehudin, Agus; Nurdin, Isdiriayani

2014-03-01

234

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

SciTech Connect

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.

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

235

Wash resistance of insecticide-treated materials  

Microsoft Academic Search

The effectiveness of insecticide-treated materials (ITMs) for malaria control is reduced by washing them. This research in Colombia and Bolivia investigated the resistance of different insecticide formulations and, in particular, a commercially available impregnated bednet (PermaNet®) which provides chemical protection for the insecticide. The fabrics studied were all polyester; the pyrethroids used for impregnation were deltamethrin (tablet and suspension concentrate

JoséOrdóñez González; Axel Kroeger; Ana Isabel Aviña; Eulides Pabón

2002-01-01

236

flu preparations Wash your hands, cover  

E-print Network

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

Victoria, University of

237

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...

238

Revegetation of an abandoned coal washing site  

Microsoft Academic Search

Various reclamation techniques were applied on an abandoned coal washing pond in western Kentucky. The entire site was treated with fertilizer and lime to add nutrients and neutralize the soil pH. Four main treatments and control plots were established. The treatments included bark; straw and manure; bark, sawdust and manure; and a mixture of sewer sludge and kiln dust.. Plots

Matthew H. Pelkki; James M. Ringe; Donald H. Graves

1995-01-01

239

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...

240

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...

241

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...

2009-10-01

242

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

NASA Technical Reports Server (NTRS)

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.

1984-01-01

243

Electrodialysis of calcium and carbonate high concentration solutions and impact on composition in cations of membrane fouling.  

PubMed

Fouling, which is the accumulation of undesired solid materials at the phase interfaces of permselective membranes, is one of the major problems in electrodialysis. The objectives of the present work were to investigate the effect of the composition in calcium and carbonate of a model solution to be treated by conventional electrodialysis on their migration kinetics and the composition in cations of the membrane fouling. In the absence of sodium carbonate in the solution, no fouling was visually observed on anion-exchange membranes (AEM) and fouling was observed only at 1600 mg/L CaCl2 on cation-exchange membrane (CEM), while at only 800 mg/L CaCl2 with sodium carbonate, a deposit was observed on both membranes. This difference could be explained by the fact that carbonate has a high buffer capacity, and the time to reach pH 4.0 was then longer than the one without carbonate. Consequently, the migration of the ionic species was carried out over a longer period of time during ED treatment with sodium carbonate addition and in extent the demineralization rates were higher: 43 vs 86%. For treatment with sodium carbonate and 1600 mg/L CaCl2, the higher migration during ED treatment, increased the concentration of calcium, from 14.24 to 93.38 mg/g dry membrane and from 0.74 to 10.27 mg/g dry membrane for CEM and AEM, respectively. Due to the basic pH on the side of the membrane in contact with the NaCl solution, the calcium would precipitate to form calcium hydroxide on CEM while the calcium migrated through the CEM was blocked by the AEM where it formed another fouling. PMID:15897083

Bazinet, Laurent; Araya-Farias, Monica

2005-06-15

244

Characterization of atomic structure of oxide films on carbon steel in simulated concrete pore solutions using EELS  

NASA Astrophysics Data System (ADS)

The atomic structure of oxide films formed on carbon steel that are exposed to highly alkaline simulated concrete pore solutions was investigated using Electron Energy Loss Spectroscopy (EELS). In particular, the effect of chloride exposure on film structure was studied in two types of simulated pore solutions: saturated calcium hydroxide (CH) and a solution prepared to represent typical concrete pore solutions (CP). It was shown that the films that form on carbon steel in simulated concrete pore solutions contained three indistinct layers. The inner oxide film had a structure similar to that of FeIIO, which is known to be unstable in the presence of chlorides. The outer oxide film mainly resembled Fe3O4 (FeIIO·Fe2IIIO3) in the CH solution and ?-Fe2IIIO3/Fe3O4 in the CP solution. The composition of the transition layer between the inner and outer layers of the oxide film was mainly composed of Fe3O4 (FeIIO·Fe2IIIO3). In the presence of chloride, the relative amount of the FeIII/FeII increased, confirming that chlorides induce valence state transformation of oxides from FeII to FeIII, and the difference between the atomic structures of oxide film layers diminished.

Gunay, H. Burak; Ghods, Pouria; Isgor, O. Burkan; Carpenter, Graham J. C.; Wu, Xiaohua

2013-06-01

245

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

USGS Publications Warehouse

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.

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

2011-01-01

246

Mechanisms controlling the production and transport of methane, carbon dioxide, and dissolved solutes within a boreal peatland  

SciTech Connect

Peatlands are one of the most important terrestrial reservoirs in the global cycle for carbon, and are a major source for atmospheric methane. However, little is known about the dynamics of these carbon reservoirs or their feedback mechanisms with the pool of atmospheric CO{sub 2} during the Holocene. Specifically, it is unknown whether large peat basins are sources, sinks, or steady-state reservoirs for the global carbon cycle. In particular, the production and transport of methane, carbon dioxide, and dissolved organic carbon form the deeper portions of these peatlands is unknown. Our DOE research program is to conduct an integrated ecologic and hydrogeochemical study of the Glacial Lake Agassiz peatlands (northern Minnesota) to better understand the carbon dynamics in globally significant peat basins. Specifically, our study will provide local and regional data on (1), rates of carbon accumulation and loss and fluxes of methane in the peat profiles; (2) the physical and botanical factors controlling the production of methane and carbon dioxide in the wetland; and (3) the role of hydrogeologic processes in controlling the fluxes of gases and solutes through the peat. We intend to use computer simulation models, calibrated to field data, to scale-up from local to regional estimates of methane and carbon dioxide within the basin. How gases and dissolved organic carbon escapes form peatlands in unknown. It has been suggested that the concentrations of methane produced in the upper peat are sufficient to produce diffusion gradients towards the surface. Alternatively, gas may move through the peat profile by groundwater advection.

Siegel, D.I.

1992-04-09

247

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

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

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

2013-08-01

248

Modification of granular activated carbon using low molecular weight polymer for enhanced removal of Cu(2+) from aqueous solution.  

PubMed

Palm shell activated carbon was modified via surface impregnation with polyethyleneimine (PEI) to enhance removal of Cu(2+) from aqueous solution in this study. The effect of PEI modification on batch adsorption of Cu(2+) as well as the equilibrium behavior of adsorption of metal ions on activated carbon were investigated. PEI modification clearly increased the Cu(2+) adsorption capacities by 68% and 75.86% for initial solution pH of 3 and 5 respectively. The adsorption data of Cu(2+) on both virgin and PEI-modified AC for both initial solution pH of 3 and 5 fitted the Langmuir and Redlich-Peterson isotherms considerably better than the Freundlich isotherm. PMID:18025736

Yin, C Y; Aroua, M K; Daud, W M A W

2007-01-01

249

Functionalization of Multiwalled Carbon Nanotubes by Solution Plasma Processing in Ammonia Aqueous Solution and Preparation of Composite Material with Polyamide 6  

NASA Astrophysics Data System (ADS)

Solution plasma processing (SPP) has been performed on multiwalled carbon nanotubes (MWCNTs) in ammonia aqueous solution. The MWCNTs, which do not disperse in aqueous solution, uniformly dispersed after the SPP. Only 2 h was required to obtain 10 g of the dispersed MWCNTs, while 7 days and additional chemicals were required for 185 mg in a previous study. The X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy of the SPP-treated MWCNTs revealed that nitrogen- and oxygen-containing groups are formed on the MWCNTs. Serious damage to the MWCNT structure was not observed in the Raman spectrum or transmission electron microscopy images of the SPP-treated MWCNTs. The composite materials prepared using polyamide 6 with the SPP-treated MWCNTs showed better tensile, bending, and impact strength than those prepared with nontreated MWCNTs.

Shirafuji, Tatsuru; Noguchi, Yohei; Yamamoto, Taibou; Hieda, Junko; Saito, Nagahiro; Takai, Osamu; Tsuchimoto, Akiharu; Nojima, Kazuhiro; Okabe, Youji

2013-12-01

250

Characteristics of cesium ion sorption from aqueous solution on bentonite- and carbon nanotube-based composites.  

PubMed

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

Yang, Shubin; Han, Cho; Wang, Xiangke; Nagatsu, Masaaki

2014-06-15

251

Determination of carbon-centered radicals in aqueous solution by liquid chromatography with fluorescence detection  

SciTech Connect

A simple method to detect subnanomolar to micromolar levels of photochemically generated carbon-centered radicals in aqueous solutions has been developed and optimized. This method is based on the efficient trapping of radicals by a water-soluble amino nitroxide, followed by derivatization of the trapped products with fluorescamine to produce highly fluorescent adducts. These adducts can be separated by reversed-phase high-performance liquid chromatography and detected fluorometrically. The fluorescent derivatives are stable over a period of days. The detection limit, primarily determined by reagent interferences, ranged from 0.3 to 1 nM per analyte for a 500-{mu}L injection at a signal-to-noise ratio of two. The precision of the method for the determination of adduct concentrations in the 1-10 nM range varied from 2.4 to 8.4% relative standard deviation (n = 6). A direct comparison with electron paramagnetic resonance spectroscopy/spin trapping illustrates the advantages of our technique. One important feature of the method is that it permits the simultaneous detection of an array of radicals, as demonstrated through the study of the photochemical production of radicals in a variety of natural water samples and in Suwanee River fulvic acid.

Kieber, D.J.; Blough, N.V. (Woods Hole Oceanographic Institution, MA (USA))

1990-11-01

252

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

NASA Astrophysics Data System (ADS)

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.

Lehtimäki, Suvi; Tuukkanen, Sampo; Pörhönen, Juho; Moilanen, Pasi; Virtanen, Jorma; Honkanen, Mari; Lupo, Donald

2014-06-01

253

2-chlorophenol sorption from aqueous solution using granular activated carbon and polymeric adsorbents  

NASA Astrophysics Data System (ADS)

Adsorption equilibrium and kinetics of 2-chlorophenol (2-CP) one of the chlorophenols (CPs) onto bituminous coal based Filtrasorb-400 grade granular activated carbon and three different types of polymeric adsorbents were studied in aqueous solution in a batch system. Langmuir isotherm models were applied to experimental equilibrium data of 2-CP adsorption. Equilibrium data fitted very well to the Langmuir equilibrium models of 2-CP. Adsorbent monolayer capacity Q Langmuir constant b and adsorption rate constants k a were evaluated. 2-CP adsorption using GAC is very rapid in the first hour of contact where 70-80% of the adsorbate is removed by GAC followed by a slow approach to equilibrium. Whereas in case of polymeric adsorbents 60-65% of the adsorbate is removed in the first 30 min which is then followed by a slow approach to equilibrium. The order of adsorption of 2-CP on different adsorbents used in the study is found to be in following order: F-400 > XAD-1180 > XAD-4 > XAD-7HP.

Ghatbandhe, A. S.; Jahagirdar, H. G.; Yenkie, M. K. N.; Deosarkar, S. D.

2013-08-01

254

Recoverable solution reaction of HiPco carbon nanotubes with hydrogen peroxide.  

PubMed

There is increasing interest in developing single-walled carbon nanotubes (SWNTs)-based optical biosensors for remote or in vitro and in vivo sensing because the near-IR optical properties of SWNTs are very sensitive to surrounding environmental changes. Many enzyme-catalyzed reactions yield hydrogen peroxide (H(2)O(2)) as a product. To our knowledge, there is no report on the interaction of H(2)O(2) with SWNTs from the optical sensing point of view. Here, we study the reaction of H(2)O(2) with an aqueous suspension of water-soluble (ws) HiPco SWNTs encased in the surfactant sodium dodecyl sulfate (SDS). The SWNTs are optically sensitive to hydrogen peroxide in pH 6.0 buffer solutions through suppression of the near-IR absorption band intensity. Interestingly, the suppressed spectral intensity of the nanotubes recovers by increasing the pH, by decomposing the H(2)O(2) into H(2)O and O(2) with the enzyme catalase, and by dialytically removing H(2)O(2). Preliminary studies on the mechanisms suggest that H(2)O(2) withdraws electrons from the SWNT valence band by charge transfer, which suppresses the nanotube spectral intensity. The findings suggest possible enzyme-assisted molecular recognition applications by selective optical detection of biological species whose enzyme-catalyzed products include hydrogen peroxide. PMID:16853809

Song, Chulho; Pehrsson, Pehr E; Zhao, Wei

2005-11-24

255

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...

256

Stress corrosion cracking of X-60 line pipe steel in a carbonate-bicarbonate solution  

SciTech Connect

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

Pilkey, A.K.; Lambert, S.B.; Plumtree, A. (Univ. of Waterloo, Ontario (Canada). Dept. of Mechanical Engineering)

1995-02-01

257

The radiation induced chemistry of uranyl cation in aqueous carbonate –bicarbonate solutions as followed by NMR spectroscopy  

SciTech Connect

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.

McNamara, Bruce K.; Snow, Lanee A.; Soderquist, Chuck Z.; Sinkov, Sergei I.; Cho, Herman M.; Friese, Judah I.

2006-05-01

258

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

NASA Technical Reports Server (NTRS)

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.

1978-01-01

259

Morphology of carbonates particles precipitated from saline waste solution: Influence of magnesium  

NASA Astrophysics Data System (ADS)

The role of a very low concentration of Mg on the nature, morphology and surface of carbonate particles during soda-ash residual brine carbonation has been studied. The Mg concentration of 200 mg/kg in brine slows down the kinetic of carbonation, modifies the shape of precipitated particles and new carbonated phases are precipitated. The existence of aragonite and (Ca, Mg) hydrated phases is supposed for Ca:Mg ratio equivalent to 24:1 in solid fraction.

Filippov, L. O.; Grandjean, M.; Filippova, I. V.; Pelletier, M.

2013-03-01

260

Carbonized properties of iodine-incorporated poly(vinyl alcohol) composite films prepared by gelation/crystallization from solution.  

PubMed

Poly(vinyl alcohol) (PVA) and titanium dioxide (TiO(2)) composite films were prepared by gelation/crystallization from a dispersed solution containing different TiO(2) contents against PVA. Iodine was incorporated into the composites, and the iodine-incorporated composites were carbonized under argon gas in the temperature range of 700-1600 degrees C. Under the carbonization process, the incorporation of iodine into composites ensured tough films without cracks. This indicated that iodine incorporation played an important role as a catalyst to promote the formation of cross links between amorphous carbon chains through the resultant Ti-C structure that occurs by hydration. Surprisingly, X-ray diffraction intensity measurements revealed that the coagulated TiO(2) powders in the composite film carbonized at 1200 degrees C remained predominantly anatase type, which has generally been known as photocatalytic activity. The perfect transition to the rutile-type structure dramatically occurred at 1600 degrees C. Judging from the carbon coating on the TiO(2) particle surface as detected by ESCA, no disruption of the composite was found to be due to the appearances of Ti(2)O(3) groups and the Ti-C structure performing cross linking between neighboring amorphous carbon chains. The characteristics of anatase-type TiO(2) crystallites and amorphous carbon structures were analyzed using the para-crystalline theory concerning the distance fluctuation between graphene sheets. The electrical conductivity of the carbonized composite was ca. 0.01 S/cm and was independent of the TiO(2) admixed in the carbon matrix. PMID:19883066

Nakano, Yumiko; Matsuo, Masaru

2010-02-16

261

Toward a zero-carbon energy policy in Europe: defining a viable solution  

SciTech Connect

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)

Jones, Christopher; Glachant, Jean-Michel

2010-04-15

262

30 CFR 206.260 - Allocation of washed coal.  

Code of Federal Regulations, 2010 CFR

... 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...

2010-07-01

263

30 CFR 206.459 - Allocation of washed coal.  

Code of Federal Regulations, 2010 CFR

... 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...

2010-07-01

264

30 CFR 1206.260 - Allocation of washed coal.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Allocation of washed coal. 1206.260 Section 1206.260 Mineral...RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.260 Allocation of washed coal. (a) When coal is subjected to...

2012-07-01

265

30 CFR 1206.260 - Allocation of washed coal.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Allocation of washed coal. 1206.260 Section 1206.260 Mineral...RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.260 Allocation of washed coal. (a) When coal is subjected to...

2013-07-01

266

30 CFR 1206.459 - Allocation of washed coal.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Allocation of washed coal. 1206.459 Section 1206.459 Mineral...RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.459 Allocation of washed coal. (a) When coal is subjected to...

2014-07-01

267

30 CFR 1206.459 - Allocation of washed coal.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Allocation of washed coal. 1206.459 Section 1206.459 Mineral...RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.459 Allocation of washed coal. (a) When coal is subjected to...

2012-07-01

268

30 CFR 1206.260 - Allocation of washed coal.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Allocation of washed coal. 1206.260 Section 1206.260 Mineral...RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.260 Allocation of washed coal. (a) When coal is subjected to...

2014-07-01

269

30 CFR 1206.459 - Allocation of washed coal.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Allocation of washed coal. 1206.459 Section 1206.459 Mineral...RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.459 Allocation of washed coal. (a) When coal is subjected to...

2013-07-01

270

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

271

Hospital Workers Wash Hands Less At End of Shift  

MedlinePLUS

... this page, please enable JavaScript. Hospital Workers Wash Hands Less at End of Shift, Study Finds New ... HealthDay News) -- Health workers in hospitals wash their hands less often as they near the end of ...

272

Why Is Hand Washing So Important? (For Parents)  

MedlinePLUS

... to Expect Ebola: What to Know Why Is Hand Washing So Important? KidsHealth > Parents > General Health > Sick ... and most types of infectious diarrhea . Continue Washing Hands Correctly Here's how to scrub those germs away. ...

273

49 CFR 230.60 - Time of washing.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Time of washing. 230.60 Section 230...DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Washing Boilers § 230.60 Time of...

2010-10-01

274

30 CFR 1206.260 - Allocation of washed coal.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Allocation of washed coal. 1206.260 Section 1206.260 Mineral...Resources Revenue PRODUCT VALUATION Federal Coal § 1206.260 Allocation of washed coal. (a) When coal is subjected to...

2011-07-01

275

30 CFR 1206.459 - Allocation of washed coal.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Allocation of washed coal. 1206.459 Section 1206.459 Mineral...Resources Revenue PRODUCT VALUATION Indian Coal § 1206.459 Allocation of washed coal. (a) When coal is subjected to...

2011-07-01

276

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

277

A new technique for bladder washing.  

PubMed

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

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

1992-01-01

278

Washing of the AN-107 entrained solids  

SciTech Connect

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.

GJ Lumetta; FV Hoopes

2000-03-31

279

30 CFR 1206.458 - Determination of washing allowances.  

Code of Federal Regulations, 2011 CFR

...estimates of the allowable coal washing costs for the...industry data for similar coal wash plants. (v...situations which are in effect at the time these regulations...shall qualify as being in effect at the time these regulations...3) ONRR may establish coal washing allowance...

2011-07-01

280

Why Do I Need to Wash My Hands?  

MedlinePLUS

... Society Why Do I Need to Wash My Hands? KidsHealth > Kids > Q&A > Q & A > Why Do I Need to Wash My Hands? Print A A A Text Size "Did you wash your hands?" How many times did you hear that today? ...

281

Remediation of arsenic-contaminated soils and washing effluents  

Microsoft Academic Search

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

Min Jang; Jung Sung Hwang; Sang Il Choi; Jae Kwang Park

2005-01-01

282

Postharvest decay reduction of fig fruit (Ficus carica) by hot water sodium carbonate solutions dip.  

PubMed

Treatments as hot water dips or high temperature conditioning have been proven to be effective to control postharvest decay on various horticultural crops. These treatments reduce chilling injury and rot losses without causing detrimental effects on fruit firmness, flavour, taste or peel appearance. These technologies, aimed to control postharvest pathogens, can be easily matched with the use of "Generally Recognized as Safe" (G.R.A.S.) compounds and employed alternatively to pesticides, known to be harmful to health and environment. In this respect we studied the combined effect of sodium carbonate (SC) and hot water on the storability of black fig fruit cultivar 'Niedda Longa' of Sardinian germplasm. Second crop fig fruit, harvested in the middle of September, was dipped for one minute in water solutions containing 0, 0.05, 0.5, and 1% (w/v) of SC at 25 or 60 degrees C and then stored at 5 degrees C and 90% relative humidity (RH) for two weeks. After one and two weeks of storage decay, weight loss were monitored and visual assessment was scored. Treatments with hot solutions were more effective in controlling decay compared to cold ones and the best results were achieved with 0.5% of SC at 60 degrees C. This combination reduced the decay rate from 26% (control) to 0% after 1 week and from 50% to 14% after two weeks of storage, respectively. Lower or higher SC concentrations applied at 60 degrees C were less effective and, after two weeks of storage, decay percentages were 38 and 43.6%, respectively. Water dip at 60 degrees C did not affect the weight loss as compared to dips at 25 degrees C either after one or two weeks of storage. At the same time, a significant reduction was found only with 1% of SC at 25 degrees C. The fruit treated with 0.5% of SC at 60 degrees C also had the best visual assessment up to two weeks of storage. PMID:17390840

Molinu, M G; Venditti, T; Dore, A; D'Hallewin, G; Serusi, A; Del Caro, A; Agabbio, M

2006-01-01

283

Synthesis of multi-walled carbon nanotube\\/silver nanocomposite powders by chemical reduction in aqueous solution  

Microsoft Academic Search

Carbon nanotube (CNT)\\/silver nanocomposite powders with different volume fractions of CNTs 2.5, 5 and 10?vol.% were prepared by chemical reduction in solution. Multi-walled CNTs underwent surface modifications for functionalisations by acid treatments. The acid-treated CNTs were investigated by FT-IR and X-ray photoelectron spectroscopy. The spectroscopic investigations of the acid-functionalised CNTs detected that several kinds of functional groups attached with the

Walid M. Daoush; Soon H. Hong

2012-01-01

284

Desalination by ammonia–carbon dioxide forward osmosis: Influence of draw and feed solution concentrations on process performance  

Microsoft Academic Search

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

Jeffrey R. McCutcheon; Robert L. McGinnis; Menachem Elimelech

2006-01-01

285

Removal of black carbon particles from experimental flue gas by surfactant solution in a new type of umbrella plate scrubber  

Microsoft Academic Search

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

Pei Lu; Caiting Li; Guangming Zeng; Yapei Zhao; Qi Zhan; Jingke Song; Xiaopeng Fan

2012-01-01

286

Influence of a protein on the crystallization of calcium phosphates and carbonates from solutions simulating human blood plasma  

Microsoft Academic Search

Experiments on the steady-state crystallization of calcium phosphates and carbonates from aqueous solutions simulating human blood plasma under typical physiological conditions (37.0 +\\/- 0.2degreesC and pH 7.35 +\\/- 0.05) were performed. The influence of a dissolved protein (bovine serum albumin) on the crystallization was studied. It was found that the amorphism of the precipitate increases with the concentration of the

S V Dorozhkin

2004-01-01

287

Utilization of activated carbon produced from fruit juice industry solid waste for the adsorption of Yellow 18 from aqueous solutions.  

PubMed

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

Angin, Dilek

2014-09-01

288

Preparation of activated carbons from Iris tectorum employing ferric nitrate as dopant for removal of tetracycline from aqueous solutions.  

PubMed

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

Li, Gang; Zhang, Dongsheng; Wang, Man; Huang, Ji; Huang, Lihui

2013-12-01

289

A novel potassium ion intercalating carbon aqueous solution ultra capacitor for very high wattage pulse output  

Microsoft Academic Search

Attempts have been made to develop a new novel potassium ion intercalating carbon\\/aqueous potassium carbonate\\/carbon ultra capacitor and capacitor banks. Cyclic voltammetric studies have been carried out to select suitable electrode materials for capacitors and better capacitor electrolytes. Charge-discharge studies on fabricated capacitors and capacitor banks have been reported. Impedance spectroscopy and X-ray diffraction studies also have been carried out

V. Kapali; V. Balaramachandran; K. B. Sarangapani; S. Muralidharan; S. Venkatakrishna Iyer

1998-01-01

290

Chemical and structural evaluation of activated carbon prepared from jute sticks for Brilliant Green dye removal from aqueous solution.  

PubMed

Activated carbons have been prepared from jute sticks by chemical activation using ZnCl(2) and physical activation using steam for the removal of Brilliant Green dye from aqueous solution. The activated carbons and charcoal prepared from jute sticks were characterized by evaluating the surface chemistry, structural features and surface morphology. The maximum BET surface area was obtained to be 2304 m(2)/g for chemical activated carbon (ACC) while it is 730 and 80 m(2)/g for steam activated carbon (ACS) and charcoal, respectively. The FT-IR spectra exhibited that the pyrolysis and steam activation of jute sticks resulted in the release of aliphatic and O-containing functional groups by thermal effect. However, the release of functional groups is the effect of chemical reaction in the ZnCl(2) activation process. A honeycomb-type carbon structure in ACC was formed as observed on SEM images. Although charcoal and ACC were prepared at 500 degrees C the ACC exhibited much lower Raman sensitivity due to the formation of condensed aromatic ring systems. Due to high surface area and high porous structure with abundance of functional groups, the ACC adsorbed dye molecules with much higher efficiency than those of ACS and charcoal. PMID:19815339

Asadullah, Mohammad; Asaduzzaman, Mohammad; Kabir, Mohammad Shajahan; Mostofa, Mohammad Golam; Miyazawa, Tomohisa

2010-02-15

291

Standing surface acoustic wave (SSAW)-based cell washing.  

PubMed

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

Li, Sixing; Ding, Xiaoyun; Mao, Zhangming; Chen, Yuchao; Nama, Nitesh; Guo, Feng; Li, Peng; Wang, Lin; Cameron, Craig E; Huang, Tony Jun

2014-12-01

292

Bubble shrinkage and growth: A solution to carbon dioxide dissolution and solubility  

NASA Astrophysics Data System (ADS)

Dynamic and equilibrium aspects of carbon dioxide transport across gas-liquid interfaces impact a wide range of technical, physiological and geological applications. We investigate carbon dioxide transport by continuously guiding a train of uniformly sized carbon dioxide bubbles and non-saturated liquid segments through a microchannel. The bubbles initially shrink and later expand. We quantitatively link the evolution of the bubble size to kinetic and equilibrium characteristics of carbon dioxide dissolution. While the initial velocity of carbon dioxide bubbles and the length of liquid segments significantly affect the dissolution of carbon dioxide, these parameters cannot be externally imposed, due to the dynamic nature of microscale gas-liquid flows. We use an automated microfluidic platform (gas impermeable) in combination with an image-based feedback control strategy to keep the dependent parameters constant and systematically determine the rate of carbon dioxide dissolution and the equilibrium solubility of carbon dioxide-liquid mixtures for a wide range of pressures, temperatures and liquids in a flowable format.

Abolhasani, Milad; Kumacheva, Eugenia; Guenther, Axel

2011-11-01

293

Electrochemical splitting of calcium carbonate to increase solution alkalinity: implications for mitigation of carbon dioxide and ocean acidity.  

PubMed

Electrochemical splitting of calcium carbonate (e.g., as contained in limestone or other minerals) is explored as a means of forming dissolve hydroxides for absorbing, neutralizing, and storing carbon dioxide, and for restoring, preserving, or enhancing ocean calcification. While essentially insoluble in water, CaCO3 can be dissolved in the presence of the highly acidic anolyte of a water electrolysis cell. The resulting charged constituents, Ca2+ and C03(2-), migrate to the cathode and anode, respectively, forming Ca(OH)2 on the one hand and H2CO3 (or H2O and CO2) on the other. By maintaining a pH between 6 and 9, subsequent hydroxide reactions with CO2 primarily produce dissolved calcium bicarbonate, Ca(HCO3)2aq. Thus, for each mole of CaCO3 split there can be a net capture of up to 1 mol of CO2. Ca(HCO3)2aq is thus the carbon sequestrant that can be diluted and stored in the ocean, in natural or artificial surface water reservoirs, or underground. The theoretical work requirement for the reaction is 266 kJe per net mole CO2 consumed. Even with inefficiencies, a realized net energy expenditure lower than the preceding quantity appears possible considering energy recovery via oxidation of the H2 produced. The net process cost is estimated to be <$100/tonne CO2 mitigated. An experimental demonstration of the concept is presented, and further implementation issues are discussed. PMID:19192821

Rau, Greg H

2008-12-01

294

Washing Away Bioprocessing Cost: Pressurized Hot Wash Improves Cellulosic Ethanol Technology  

SciTech Connect

Thermochemical pretreatment is a key step in biotechnology for converting lignocellulosic biomass to fuel ethanol and other valuable chemicals. U.S. Department of Energy Biofuels Program researchers have found that adding a Pressurized Hot Wash (PHW) step immediately following pretreatment--while the pretreated material is still at high temperature and pressure--significantly improves the overall process. The ''hot-washed'' pretreated material can be more efficiently digested by cellulase enzymes. Additionally, soluble lignins with potentially valuable unique reactive properties are separated out.

Not Available

2002-09-01

295

Ion Enrichment on the Hydrophobic Carbon-based Surface in Aqueous Salt Solutions due to Cation-? Interactions  

PubMed Central

By incorporating cation-? interactions to classic all-atoms force fields, we show that there is a clear enrichment of Na+ on a carbon-based ? electron-rich surface in NaCl solutions using molecular dynamics simulations. Interestingly, Cl? is also enriched to some extend on the surface due to the electrostatic interaction between Na+ and Cl?, although the hydrated Cl?-? interaction is weak. The difference of the numbers of Na+ and Cl? accumulated at the interface leads to a significant negatively charged behavior in the solution, especially in nanoscale systems. Moreover, we find that the accumulation of the cations at the interfaces is universal since other cations (Li+, K+, Mg2+, Ca2+, Fe2+, Co2+, Cu2+, Cd2+, Cr2+, and Pb2+) have similar adsorption behaviors. For comparison, as in usual force field without the proper consideration of cation-? interactions, the ions near the surfaces have a similar density of ions in the solution. PMID:24310448

Shi, Guosheng; Liu, Jian; Wang, Chunlei; Song, Bo; Tu, Yusong; Hu, Jun; Fang, Haiping

2013-01-01

296

Immobilization of enzymes on activated carbon: selection and preparation of the carbon support.  

PubMed

Based upon its superior catalytic activity for H2O2 decomposition, a bituminous coal-based activated carbon was selected for investigations of pretreatment and enzyme immobilization methods. Pretreatments considered include acid washing, exposure to strong oxidizing agents, contact with concentrated peroxide solutions, nitration and amination, isothiocyanate derivatization, silanization, and stearic acid coating. Effects of these pretreatments on morphology and trace-metal content of the carbon pellets have been studied using scanning electron microscopy and dispersive analysis of x rays. Immobilization of glucoamylase by adsorption, glutaraldehyde crosslinking, and covalent attachment to carbon activated by water-soluble diimide or diazotization have been examined. These different enzyme-carbon catalysts have been characterized by their enzyme loading, enzyme activity, catalytic activity for H2O2 decomposition, or combinations of these measures of performance. PMID:106909

Cho, Y K; Bailey, J E

1979-03-01

297

Soil remediation: humic acids as natural surfactants in the washings of highly contaminated soils.  

PubMed

The remediation of the highly contaminated site around the former chemical plant of ACNA (near Savona) in Northern Italy is a top priority in Italy. The aim of the present work was to contribute in finding innovative and environmental-friendly technology to remediate soils from the ACNA contaminated site. Two soils sampled from the ACNA site (A and B), differing in texture and amount and type of organic contaminants, were subjected to soil washings by comparing the removal efficiency of water, two synthetic surfactants, sodium dodecylsulphate (SDS) and Triton X-100 (TX100), and a solution of a natural surfactant, a humic acid (HA) at its critical micelle concentration (CMC). The extraction of pollutants by sonication and soxhlet was conducted before and after the soil washings. Soil A was richer in polycyclic aromatic hydrocarbons, whereas soil B had a larger content of thiophenes. Sonication resulted more analytically efficient in the fine-textured soil B. The coarse-textured soil A was extracted with a general equal efficiency also by soxhlet. Clean-up by water was unable to exhaustively remove contaminants from the two soils, whereas all the organic surfactants revealed very similar efficiencies (up to 90%) in the removal of the contaminants from the soils. Hence, the use of solutions of natural HAs appears as a better choice for soil washings of highly polluted soils due to their additional capacity to promote microbial activity, in contrast to synthetic surfactants, for a further natural attenuation in washed soils. PMID:15749548

Conte, Pellegrino; Agretto, Anna; Spaccini, Riccardo; Piccolo, Alessandro

2005-06-01

298

Influence of hydrophobic substance on enhancing washing durability of water soluble flame-retardant coating  

NASA Astrophysics Data System (ADS)

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.

Jindasuwan, Sunisa; Sukmanee, Nattinee; Supanpong, Chanida; Suwan, Mantana; Nimittrakoolchai, On-uma; Supothina, Sitthisuntorn

2013-06-01

299

The voltammetry–photocurrent response study of passivation of carbon steel in slightly alkaline solutions containing the corrosion inhibitor phosphor-polymaleic acid–ZnSO 4  

Microsoft Academic Search

The electro-oxidation\\/electro-reduction processes on the surface of a carbon steel electrode were studied in borate buffer solutions (pH=8.4) in the presence and absence of the corrosion inhibitor phosphor-polymaleic acid (PPMA)–ZnSO4 at room temperature by using the voltammetry–photocurrent response method. For the carbon steel electrode in solutions containing the corrosion inhibitor, its voltammograms displayed a smaller oxidation peak current and a

Yi-Jiu Li; Bin Wu; Xin-Ping Zeng; Ya-Fei Liu; Ya-Ming Ni; Guo-Ding Zhou; Hong-Hua Ge

2002-01-01

300

Temperature effects on the performance of PMAN-derived carbon anodes in 1M LiPF{sub 6}/EC-DMC solution  

SciTech Connect

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.

Guidotti, R.A.; Johnson, B.J.

1998-04-01

301

TRICHLOROETHYLENE ADSORPTION BY ACTIVATED CARBON PRELOADED WITH HUMIC SUBSTANCES: EFFECTS OF SOLUTION CHEMISTRY. (R828157)  

EPA Science Inventory

Abstract Trichloroethylene (TCE) adsorption by activated carbon previously loaded ("preloaded") with humic substances was found to decrease with increasing concentrations of monovalent ions (NaCl), calcium (until solubility was exceeded), or dissolved oxygen in...

302

Comparative Study of Zn, Cd, and Pb Removal From Water Solution Using Natural Clinoptilolitic Zeolite and Commercial Granulated Activated Carbon. Equilibrium of Adsorption  

Microsoft Academic Search

The aim of this work is to study the effectiveness of regional, low-cost natural clinoptilolitic zeolite tuff in heavy metal ions removal from aqueous solution, through comparative study with commercial granulated activated carbon. The equilibrium of adsorption of Cd, Pb, and Zn on both adsorbents have been determined at 25, 35, and 45°C in batch mode. The granulated activated carbon

M. Minceva; R. Fajgar; L. Markovska; V. Meshko

2008-01-01

303

Corrosion inhibition behavior of propyl phosphonic acid-Zn2+ system for carbon steel in aqueous solution  

NASA Astrophysics Data System (ADS)

The effectiveness of propyl phosphonic acid (PPA) as a corrosion inhibitor in association with a bivalent cation like Zn2+ has been studied. An eco-friendly inhibitor in controlling corrosion of carbon steel in neutral aqueous medium in the absence and presence of Zn2+ has been evaluated by gravimetric method. Impedance studies of the metal/solution interface indicated that the surface film is highly protective against the corrosion of carbon steel in the aqueous environment. Potentiodynamic polarization studies showed that the inhibitor is a mixed inhibitor. X-ray photoelectron spectroscopic analysis (XPS) of the protective film exhibited the presence of the elements viz., iron, phosphorus, oxygen, carbon and zinc. The chemical shifts in the binding energies of these elements inferred that the surface film is composed of oxides/hydroxides of iron(III), Zn(OH)2 and [Fe(II)/(III)-Zn(II)-PPA] complex. Further, the surface analysis techniques viz., FT-IR, AFM and SEM studies confirm the formation of an adsorbed protective film on the carbon steel surface. Based on all these results, a plausible mechanism of corrosion inhibition is proposed.

Prabakaran, M.; Venkatesh, M.; Ramesh, S.; Periasamy, V.

2013-07-01

304

Cross-contamination of fresh-cut lettuce after a short-term exposure during pre-washing cannot be controlled after subsequent washing with chlorine dioxide or sodium hypochlorite.  

PubMed

Chlorine dioxide (ClO(2)) has been postulated as an alternative to sodium hypochlorite (NaClO) for fresh-cut produce sanitization to avoid risks associated with chlorination by-products. Experiments were performed to determine the prevention of cross-contamination of fresh-cut lettuce by Escherichia coli using chlorine dioxide (3 mg/L) or sodium hypochlorite (100 mg/L) as sanitation agents. The efficacy of these sanitation solutions was evaluated simulating as much as possible the conditions of a fresh-cut processing line. Thus, to evaluate the potential risk of cross-contamination during pre-washing, inoculated fresh-cut lettuce was pre-washed and after that non-inoculated lettuce was then pre-washed in the same water. After this pre-washing, non-inoculated lettuce was cross-contaminated, changing from 0 to 3.4 log units of E. coli cells. During washing with sanitizers, none of the tested sanitation agents significantly reduced E. coli counts in both inoculated and cross-contaminated lettuce. These results suggest that when cross-contamination occurs, even if the event is recent, subsequent sanitation steps are inefficient for inactivating E. coli cells on the vegetable tissue. However, chlorine dioxide and sodium hypochlorite solutions were able to inactivate most E. coli cells that passed from inoculated product to wash water. Therefore, they might be able to avoid cross-contamination between clean and contaminated product during the washing step. Scanning electron microscopy micrographs indicated that bacterial cells were mainly located in clusters or tissue stomata where they might be protected, which explains the low efficacy of sodium hypochlorite and chlorine dioxide solutions observed in this study. PMID:20141936

López-Gálvez, Francisco; Gil, María I; Truchado, Pilar; Selma, María V; Allende, Ana

2010-04-01

305

Depositional environment and reservoir characteristics of Middle Pennsylvanian Granite Wash, northern Palo Duro basin, Oldham County, Texas  

SciTech Connect

The Lambert 1, Hryhor, and Sundance fields in Oldham County, Texas, produce oil from the Middle Pennsylvanian Canyon granite wash. Canyon granite wash conglomerates and sandstones have a maximum thickness of approximately 450 ft (140 m) and were derived from granitic rocks of the Bravo dome. The sediment was transported across carbonate platforms by streams and deposited into the Oldham trough as fan deltas. The granite wash deposits consist primarily of imbricated gravels and cross-stratified sands. Debris-flow deposits are also present. The sediment is dominantly feldspar, granitic rock fragments, and quartz. Carbonate cement averages 5% of the bulk composition. The overall geometry of the granite wash deposits is lobate. Parts of the reservoir show high lateral variability with no continuity between wells on 40-ac spacing. These reservoir facies are thus limited in areal extent and drainage area. However, some intervals can be correlated between wells, which suggests that part of the reservoir may be simulated as layered with no crossflow. The reservoir conglomerates and sandstones have an average porosity of 18% and an average permeability of 75 md/ft. Reasonable net-pay cutoff values in these granite wash reservoirs are 9.5% for porosity and 1.5 md for permeability, and were established by crossplots and cumulative volume capacity.

Vanderhill, A.L.; Berg, R.R. (Texas A and M Univ., College Station (USA))

1987-02-01

306

Junction-Controlled Elasticity of Single-Walled Carbon Nanotube Dispersions in Acrylic Copolymer Gels and Solutions  

SciTech Connect

Oscillatory shear rheometry is used to study the mechanical response of single-walled carbon nanotubes dispersed in solutions of acrylic diblock or triblock copolymers in 2-ethyl-1-hexanol. Thermal transitions in the copolymer solutions provide a route for the easy processing of these composite materials, with excellent dispersion of the nanotubes as verified by near-infrared photoluminescence spectroscopy. The nanotube dispersions form elastic networks with properties that are controlled by the junction points between nanotubes, featuring a temperature-dependent elastic response that is controlled by the dynamic properties of the matrix copolymer solution. The data are consistent with the formation of micelle-like aggregates around the nanotubes. At low temperatures the core-forming poly(methyl methacrylate) blocks are glassy, and the overall mechanical response of the composite does not evolve with time. At higher temperatures the enhanced mobility of the core-forming blocks enables the junctions to achieve more intimate nanotube-nanotube contact, and the composite modulus increases with time. These aging effects are observed in both diblock and triblock copolymer solutions but are partially reversed in the triblock solutions by cooling through the gel transition of the triblock copolymer. This result is attributed to the generation of internal stresses during gelation and the ability of these stresses to break or weaken the nanotube junctions.

Schoch, Andrew B.; Shull, Kenneth R.; Brinson, L. Catherine (NWU)

2008-08-26

307

The performance of a surface-applied corrosion inhibitor for the carbon steel in saturated Ca(OH){sub 2} solutions  

SciTech Connect

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.

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

308

Fundamental Effects of Aging on Creep Properties of Solution-Treated Low-Carbon N-155 Alloy  

NASA Technical Reports Server (NTRS)

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.

Frey, D N; Freeman, J W; White, A E

1950-01-01

309

Adsorption of nonelectrolytes from dilute aqueous solutions in carbon micropores: a condensation approximation approach  

Microsoft Academic Search

The Dubinin model of micropore volume filling for gas\\/solid adsorption is extended to describe the adsorption of nonelectrolytes from dilute aqueous solutions. Adsorption of poorly soluble organic compounds leads to the complete displacement of water from micropores and to formation of an interface between an adsorbed phase and the solution. The maximum molar work supplied by the field of the

Vladimir Kh. Dobruskin

2000-01-01

310

Precipitation polymerization of hydrophobically modified polyelectrolyte poly(AA-co-ODA) in supercritical carbon dioxide and solution rheology properties  

NASA Astrophysics Data System (ADS)

Hydrophobically modified (HM) polyelectrolytes were prepared by using precipitation polymerization of acrylic acid (AA) and octadecyl acrylate (ODA) in various molar ratios in supercritical carbon dioxide. The product was obtained in the form of a white powder and the micrographs show aggregates of primary particles < 1 ?m in size. The effects of polymer concentration, ODA content in polymer, surfactant, shear time, shear rate on the apparent viscosity were investigated. The reason leaded to a significant viscosity enhancement was discussed. Steady-state and oscillatory tests of solution were also investigated. Solution exhibited shear thinning behavior and thixotropy. Polymers contain octadecyl acrylate (3.4 mol%) at 0.2 g/dL behaved as high entanglement structures or association gels, since the modulus G' were being higher than G? throughout the frequency range. The comparison of apparent and complex viscosities confirmed the association gel properties.

Zhang, Huaiping; Li, Wei; Cao, Qing; Chen, Mingcai

2014-05-01

311

The influence of solution stoichiometry on surface-controlled Ca isotope fractionation during Ca carbonate precipitation from Mono Lake, California  

NASA Astrophysics Data System (ADS)

Precipitation of calcite and aragonite from aqueous solution causes kinetic stable Ca isotope fractionation under conditions where Ca2+ is greatly in excess of CO32-. Research on carbonate mineral growth from low Ca2+:CO32- activity ratio solutions is lacking. Mono Lake, California is a highly alkaline lake with a Ca2+:CO32- activity ratio of 9.6 x 10-4, over five orders of magnitude lower than typical terrestrial fresh and ocean water. Aragonitic tufa towers grow along the lakeshore due to the mixing of lake water and Ca-rich spring water, while fine aragonite particles precipitate directly from the lake water, accumulating on the lake bottom. Variations in the Ca2+:CO32- activity ratio affect calcite growth kinetics and could affect the partitioning of Ca isotopes during carbonate precipitation. However, the relationship between solution stoichiometry, microscopic mineral growth mechanisms and calcium isotope fractionation is poorly understood. We analyzed the Sr and Ca isotopic compositions of a suite of lake water, spring, tufa and lake bottom sediment samples from the Mono Basin. Using the Sr isotope signatures of endmember water sources (pure lake water and shoreline spring water), we determined the compositions of carbonate mineral growth solutions, associated isotope separations (?44/40Cas-f = ?44/40Casolid - ?44/40Cafluid) and precipitation rates. While lake bottom aragonite precipitates directly from lake water (Ca2+:CO32- ? 10-3), tufa grows from mixed solutions with Ca2+:CO32- activity ratios approaching 10, so carbonate precipitation in Mono Lake spans a four order of magnitude range in solution stoichiometry. At Mono Lake, ?44/40Cas-f and calculated precipitation rates vary between -0.6±0.15‰ at 1.5×10-9 mol m-2 s-1 for aragonite precipitating from lake water and ~ -1.0±0.15‰ at up to 4×10-8 mol m-2 s-1 for tufa growing from mixed spring and lake water. These values are consistent with fractionation observed during CaCO3 precipitation at much higher Ca2+:CO32- activity ratios. We attribute this similarity to the constant detachment frequency of Ca2+ from the mineral surface. Based on a model developed by DePaolo (2010), detachment frequency controls the dependence of isotope fractionation on growth rate, while excess ion attachment relative to detachment controls the rate itself. The frequency of ion attachment depends on ion activity and solution stoichiometry, whereas detachment frequency is solely defined by the solubility product and ion attachment rate constants (Zhang & Nancollas, J. Colloid Interface Sci., 1998). Thus, the Ca detachment flux from CaCO3 surfaces and the rate dependence of ?44/40Cas-f should be independent of solution stoichiometry, consistent with our findings in the Mono Lake system.

Nielsen, L. C.; Depaolo, D. J.

2010-12-01

312

The effect of fatal carbon monoxide poisoning on the equilibria between cell membranes and the electrolyte solution.  

PubMed

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

Petelska, Aneta D; Koty?ska, Joanna; Figaszewski, Zbigniew A

2015-02-01

313

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)

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.

Chen, Fei; Chen, Qi; Mao, Lin; Wang, Yixin; Huang, Xun; Lu, Wei; Wang, Bing; Chen, Liwei

2013-12-01

314

Synthesis of associating poly(acrylic acid) in supercritical carbon dioxide and its solution properties  

Microsoft Academic Search

Hydrophobically associating polymers have been synthesized in supercritical carbon dioxide by copolymerization of acrylic acid with different amounts of acrylate with hydrocarbon or fluorocarbon groups. It was found that conversion of hydrocarbon comonomers was above 95% whereas that for fluorocarbon comonomers was only about 50%. In addition, large amounts of hydrophobic groups could be easily introduced to poly(acrylic acid) by

Zhang Bin; Hongqi Hu; Mingcai Chen; Weiqu Liu

2004-01-01

315

Carbon Tax Revenue and the Budget Deficit: A Win-Win-Win Solution?  

E-print Network

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 ...

Rausch, Sebastian

316

The adsorption of gold, palladium and platinum from acidic chloride solutions on mesoporous carbons.  

SciTech Connect

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.

Peter Zalupski; Rocklan McDowell; Guy Dutech

2014-10-01

317

Using semi-analytic solutions to approximate the area of potential impact for carbon dioxide injection  

EPA Science Inventory

This study examines using the threshold critical pressure increase and the extent of the carbon dioxide (CO2) plume to delineate the area of potential impact (AoPI) for geologic CO2 storage projects. The combined area covering both the CO2 plume and the region where the pressure ...

318

Determination of Carbon Disulfide at the Workplace by Sampling on Charcoal Tubes—Problems and Solutions  

Microsoft Academic Search

The aim of the study was to check the reliability and comparability of different analytical methods for ambient monitoring of carbon disulfide (CS2). A stationary sampling system, consisting of a charcoal sampling tube and pump, and two personal sampling systems, consisting of a charcoal sampling tube and a portable pump and of a diffusive charcoal sampler have been compared. The

Th. Göen; J. Müller; J. Angerer; H. Drexler

2002-01-01

319

Presence of nanoparticles in wash water from conventional silver and nano-silver textiles.  

PubMed

Questions about how to regulate nanoenhanced products regularly arise as researchers determine possible nanoparticle transformation(s). Focusing concern on the incorporation and subsequent release of nano-Ag in fabrics often overshadows the fact that many "conventional silver" antimicrobials such as ionic silver, AgCl, metallic Ag, and other forms will also form different species of silver. In this study we used a laboratory washing machine to simulate the household laundering of a number of textiles prepared with known conventional Ag or nano-Ag treatments and a commercially available fabric incorporating yarns coated with bulk metallic Ag. Serial filtration allowed for quantification of total Ag released in various size fractions (>0.45 ?m, < 0.45 ?m, <0.1 ?m, and <10 kDa), while characterization of particles with TEM/EDX provided insight on Ag transformation mechanisms. Most conventional Ag additives yielded more total Ag and more nanoparticulate-sized Ag in the washing liquid than fabrics that used nano-Ag treatments. Incorporating nano-silver into the fiber (as opposed to surface treatments) yielded less total Ag during fabric washing. A variety of metallic Ag, AgCl, and Ag/S particles were observed in washing solution by TEM/EDX to various extents depending on the initial Ag speciation in the fabrics. Very similar particles were also observed when dissolved ionic Ag was added directly into the washing liquid. On the basis of the present study, we can state that all silver-treated textiles, regardless of whether the treatment is "conventional" or "nano", can be a source of silver nanoparticles in washing solution when laundering fabrics. Indeed, in this study we observed that textiles treated with "conventional" silver have equal or greater propensity to form nano-silver particles during washing conditions than those treated with "nano"-silver. This fact needs to be strongly considered when addressing the risks of nano-silver and emphasizes that regulatory assessment of nano-silver warrants a similar approach to conventional silver. PMID:24941455

Mitrano, Denise M; Rimmele, Elisa; Wichser, Adrian; Erni, Rolf; Height, Murray; Nowack, Bernd

2014-07-22

320

Storage Stability of Butterfish Mince (Peprilus buri) as Affected by Washing, Antioxidants, and Vacuum Packaging  

Microsoft Academic Search

Gulf of Mexico butterfish (Peprilus buri), a largely unutilized fishery resource, has been examined for its application as a food-grade marine product. Butterfish mince prewashed with sodium bicarbonate solution (0.5%) had lower lipid oxidation and free fatty acid (FFA) content than unwashed mince during a 6-month frozen storage study. Washed mince also exhibited a lower Hunter a value and had

Tein M. Lin; Samuel P. Meyers; J. Samuel Godber

1996-01-01

321

Adsorption of uranium (VI) from aqueous solution using a novel graphene oxide-activated carbon felt composite.  

PubMed

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

Chen, Shuiping; Hong, Jianxun; Yang, Hongxiao; Yang, Jizhen

2013-12-01

322

Sludge pretreatment chemistry evaluation: Enhanced sludge washing separation factors  

SciTech Connect

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.

Colton, N.G.

1995-03-01

323

Adsorption of anionic and cationic dyes on ferromagnetic ordered mesoporous carbon from aqueous solution: equilibrium, thermodynamic and kinetics.  

PubMed

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

Peng, Xiaoming; Huang, Dengpo; Odoom-Wubah, Tareque; Fu, Dafang; Huang, Jiale; Qin, Qingdong

2014-09-15

324

Solutions  

NASA Astrophysics Data System (ADS)

Type-VIII Ba8Ga16Sn30 polycrystalline clathrates were grown vertically downwards from Ba8Ga16Sn50 solution at furnace temperatures between 500°C and 800°C with an ampoule velocity of 0.36 cm/h. The microstructure, composition, crystal structure, and thermoelectric properties of crystals were investigated. Polycrystalline samples in which Ba8Ga16Sn30 grains were wetted by an Sn-rich phase were prepared. In general, grain size increases along the direction of growth. It was found that the sample grown at 650°C had the largest grains. Smaller grains were observed for samples grown at lower temperatures, as a result of higher rate of nucleation, because of higher undercooling at the solid-liquid interface caused by the lower thermal gradient in the liquid. However, at furnace temperatures higher than 650°C enhanced convection in the solution at higher temperature gradients and wetting phenomena may cause instability of the solid-liquid interface and solid nuclei may flow into the liquid to become new nucleation sites. This explains the decrease of grain size at higher furnace temperatures. The optimum ZT and power factor of the undoped Ba8Ga16Sn30 clathrate prepared by the vertical Bridgman method in this study were, respectively, 0.8 and 11.4 ?W/cmK2 at 200°C; the Seebeck coefficient was -260 ?V/K.

Hong, Qin-Gang; Chang, Li-Shin; Hsieh, Huey-Lin

2014-06-01

325

Carbide Formation and Dissolution in Biomedical Co-Cr-Mo Alloys with Different Carbon Contents during Solution Treatment  

NASA Astrophysics Data System (ADS)

The microstructures of as-cast and heat-treated biomedical Co-Cr-Mo (ASTM F75) alloys with four different carbon contents were investigated. The as-cast alloys were solution treated at 1473 to 1548 K for 0 to 43.2 ks. The precipitates in the matrix were electrolytically extracted from the as-cast and heat-treated alloys. An M23C6 type carbide and an intermetallic ? phase (Co(Cr,Mo)) were detected as precipitates in the as-cast Co-28Cr-6Mo-0.12C alloy; an M23C6 type carbide, a ? phase, an ? phase (M6C-M12C type carbide), and a ? phase (M2T3X type carbide with a ?-manganese structure) were detected in the as-cast Co-28Cr-6Mo-0.15C alloy; and an M23C6 type carbide and an ? phase were detected in the as-cast Co-28Cr-6Mo-0.25C and Co-28Cr-6Mo-0.35C alloys. After solution treatment, complete precipitate dissolution occurred in all four alloys. Under incomplete precipitate dissolution conditions, the phase and shape of precipitates depended on the heat-treatment conditions and the carbon content in the alloys. The ? phase was detected in the alloys with carbon contents of 0.15, 0.25, and 0.35 mass pct after heat treatment at high temperature such as 1548 K for a short holding time of less than 1.8 ks. The presence of the ? phase in the Co-Cr-Mo alloys has been revealed in this study for the first time.

Mineta, Shingo; Namba, Shigenobu; Yoneda, Takashi; Ueda, Kyosuke; Narushima, Takayuki

2010-08-01

326

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

327

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false COW tank washing machines. 157.124 Section 157.124 Navigation...and Installation § 157.124 COW tank washing machines. (a) COW machines must be permanently mounted in each cargo...

2012-07-01

328

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false COW tank washing machines. 157.124 Section 157.124 Navigation...and Installation § 157.124 COW tank washing machines. (a) COW machines must be permanently mounted in each cargo...

2014-07-01

329

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false COW tank washing machines. 157.124 Section 157.124 Navigation...and Installation § 157.124 COW tank washing machines. (a) COW machines must be permanently mounted in each cargo...

2013-07-01

330

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false COW tank washing machines. 157.124 Section 157.124 Navigation...and Installation § 157.124 COW tank washing machines. (a) COW machines must be permanently mounted in each cargo...

2010-07-01

331

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false COW tank washing machines. 157.124 Section 157.124 Navigation...and Installation § 157.124 COW tank washing machines. (a) COW machines must be permanently mounted in each cargo...

2011-07-01

332

30 CFR 206.259 - Determination of washing allowances.  

Code of Federal Regulations, 2010 CFR

...Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT...MINERALS REVENUE MANAGEMENT PRODUCT VALUATION...audit, and possible future adjustment...washing allowance by reporting it as a separate...audit, and possible future adjustment. The...washing allowance by reporting it as a...

2010-07-01

333

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

334

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

335

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...

336

Geoarchaeology of the Boca Negra Wash Area, Albuquerque Basin,  

E-print Network

the location of the Boca Negra Wash site, archaeological sites reported by Judge (1973, Figure 4), and key erco Jemez R iver Rio Grande N Archaeological Site Limit of Albuquerque Basin Llano de Albuquerque, University of New Mexico, Albuquerque, NM 87131 Dozens of Paleoindian sites, including the Boca Negra Wash

Holliday, Vance T.

337

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

338

Egg wash wastewater: Estrogenic risk or environmental asset?  

Technology Transfer Automated Retrieval System (TEKTRAN)

Commercial production of eggs and egg products requires the washing of eggs to remove urinary / fecal material and broken egg residue. In the case of one Ohio farming facility, 1.6 million birds produce 1.4 million eggs per day, using ~50mL of wash water / egg or ~ 70,000 liters per day. The aqueo...

339

EPA site demonstration of the Biotrol Soil Washing Process  

SciTech Connect

A pilot-scale soil washing process, patented by BioTrol, was demonstrated on soil that was contaminated by wood treating waste. The BioTrol Soil Washing was demonstrated in a treatment train sequence with two other pilot-scale units of BioTrol technologies for treatment of waste streams from the soil washer. The three technologies of the treatment train were: The BioTrol Soil Washer (BSW), the BioTrol Aqueous Treatment System (BATS), and the Slurry Bioreactor (SBR). The BioTrol processes were evaluated on pentachlorophenol (PCP) and polynuclear aromatic hydrocarbons (PAHs), which were the primary soil contaminants at the site. The sandy site soil, consisting of less than 10% of fines, was well suited for treatment by soil washing. The BSW successfully separated the feed soil (100% by weight) into 83% of washed soil, 10% of woody residues, and 7% of fines. The soil washer achieved up to 89% removal of PCP and PAHs, based on the difference between their levels in the feed soil and in the washed soil. The BATS degraded up to 94% of PCP in the process water from soil washing. The SBR achieved over 90% removals of PCP and 70-90% removals of PAHs, respectively from the soil washing. Cost of a commercial-scale soil washing, assuming use of all three technologies, was estimated to be $168 per ton of treated soil.

Stinson, M.K.; Skovronek, H.S.; Ellis, W.D.

1992-01-01

340

Recent Geology of Cane Wash, Monument Valley, Arizona.  

PubMed

In the article "Recent Geology of Cane Wash, Monument Valley, Arizona," by Charles B. Hunt, in the issue of 30 September, page 584, a line of type was unfortunately misplaced at the last moment. The next to the last sentence in the third column should read: "Upstream from the lake beds (Fig. 2) Cane Wash is aggrading the valley floor." PMID:17820213

Hunt, C B

1955-10-21

341

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

342

Photocurrent spectroscopy of (n, m) sorted solution-processed single-walled carbon nanotubes.  

PubMed

Variable-wavelength photocurrent microscopy and photocurrent spectroscopy are used to study the photoresponse of (n, m) sorted single-walled carbon nanotube (SWNT) devices. The measurements of (n, m) pure SWCNT devices demonstrate the ability to study the wavelength-dependent photoresponse in situ in a device configuration and deliver photocurrent spectra that reflect the population of the source material. Furthermore, we show that it is possible to map and determine the chirality population within a working optoelectronic SWCNT device. PMID:25117458

Engel, Michael; Moore, Katherine E; Alam, Asiful; Dehm, Simone; Krupke, Ralph; Flavel, Benjamin S

2014-09-23

343

Electrochemical synthesis of Cr(II) at carbon electrodes in acidic aqueous solutions  

Microsoft Academic Search

The electrochemical synthesis of Cr(II) has been investigated on a vitreous carbon rotating disc electrode and a graphite felt electrode using cyclic voltammetry, impedance spectroscopy and chronoamperometry. The results show that in 0.1 M Cr(III) + 0.5 M sulphuric acid and in 0.1 M Cr(III) + 1 M hydrochloric acid over an electrode potential range of -0.8 to 0.8 V

Q. Yin; N. P. Brandon; G. H. Kelsall

2000-01-01

344

Adsorption of Pb(II) by Peanut Hull Carbon from Aqueous Solution  

Microsoft Academic Search

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

K. Periasamy; C. Namasivayam

1995-01-01

345

Behavior of Shiga toxigenic Escherichia coli relevant to lettuce washing processes and consideration of factors for evaluating washing process surrogates.  

PubMed

Postharvest processes for fresh produce commonly include washing in water containing antimicrobial chemicals, such as chlorine; however, if the antimicrobials are not present in sufficient levels, washing can promote the spread of contamination that might be present. To understand cross-contamination risk during washing, we tested a collection of Shiga toxigenic Escherichia coli (STEC), including O157:H7 and other non-O157 strains, for certain traits during washing of fresh-cut lettuce, i.e., sensitivity to sublethal chlorine levels and ability to cross-contaminate (detach from and attach to) lettuce in the presence of sublethal chlorine levels. Nonpathogenic E. coli Nissle 1917 (EcN) and Pediococcus pentosaceus lactic acid bacterial species (LAB) were included as potential washing process validation surrogates. As measured by extension of the lag phase of growth in media containing 0.15 ppm of chlorine, chlorine sensitivity varied among the STECs. Cross-contamination was assessed by evaluating transfer of bacteria from inoculated to uninoculated leaves during washing. Without chlorine, similar transfer to wash water and uninoculated leaves was shown. In 1 ppm of chlorine, cross-contamination was not detected with most strains, except for the substantial transfer by a STEC O111 strain and EcN in some replicates. Strain O111 and EcN showed less inactivation in 0.25 ppm of chlorine water compared with O157 (P < 0.05). LAB showed similar transfer and similar chlorine inactivation to O157. Considering together the sublethal chlorine sensitivity and detachment/attachment traits, neither EcN nor LAB displayed optimal characteristics as washing process surrogates for the STEC strains, although further evaluation is needed. This work demonstrated a range of behaviors of STEC strains during lettuce washing and may be helpful in hazard characterization, identifying factors to consider for evaluating washing process efficacy, and identifying phenotypic traits to select surrogates to validate washing processes. PMID:25364918

Deng, Kaiping; Wang, Xue; Yen, Li-Han; Ding, Hongliu; Tortorello, Mary Lou

2014-11-01

346

Car wash wastewater treatment and water reuse - a case study.  

PubMed

Recent features of a car wash wastewater reclamation system and results from a full-scale car wash wastewater treatment and recycling process are reported. This upcoming technology comprises a new flocculation-column flotation process, sand filtration, and a final chlorination. A water usage and savings audit (22 weeks) showed that almost 70% reclamation was possible, and fewer than 40 L of fresh water per wash were needed. Wastewater and reclaimed water were characterized by monitoring chemical, physicochemical and biological parameters. Results were discussed in terms of aesthetic quality (water clarification and odour), health (pathological) and chemical (corrosion and scaling) risks. A microbiological risk model was applied and the Escherichia coli proposed criterion for car wash reclaimed water is 200 CFU 100 mL(-1). It is believed that the discussions on car wash wastewater reclamation criteria may assist institutions to create laws in Brazil and elsewhere. PMID:23128624

Zaneti, R N; Etchepare, R; Rubio, J

2013-01-01

347

Qualification testing and full-scale demonstration of titanium-treated zeolite for sludge wash processing  

SciTech Connect

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.

Dalton, W.J.

1997-06-30

348

Effect of activated carbon surface oxygen- and/or nitrogen-containing groups on adsorption of copper(II) ions from aqueous solution  

SciTech Connect

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.

Biniak, S.; Pakula, M.; Szymanski, G.S.; Swiatkowski, A.

1999-08-31

349

Bottle Washing LDPE bottles must be acid washed prior to use in trace element analyses. The process  

E-print Network

1 Bottle Washing LDPE bottles must be acid washed prior to use in trace element analysesL LDPE sample bottles ahead of time (three times each with Milli-Q water), as this is a time consuming the petri slide (generally the data and soluble/insoluble). Record the LDPE bottle numbers

Paytan, Adina

350

Removal of hexavalent chromium in carbonic acid solution by oxidizing slag discharged from steelmaking process in electric arc furnace  

NASA Astrophysics Data System (ADS)

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.

Yokoyama, Seiji; Okazaki, Kohei; Sasano, Junji; Izaki, Masanobu

2014-02-01

351

Controlling the optimum surfactants concentrations for dispersing carbon nanofibers in aqueous solution  

NASA Astrophysics Data System (ADS)

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.

Wang, Bao-Min; Yuan, Zhang; Guo, Zhi-Qiang; Ma, Hai-Nan; Lai, Chuan Fook

2013-12-01

352

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...

353

Yeast RNA prep (using ABI6100+Absolute RNA wash) By Marcelo Vinces, Verstrepen Lab, 13 September, 2006  

E-print Network

min, 3000 rpm. Can freeze pellets at this point, or proceed with spheroplasting. 6. Resuspend cells to Waste position and lock it. -Access the "absolute rna program" preconfigured method on ABI6100 (may. Pre-wet wells with RNA Purification Wash 40 Waste - - - Solution 1. 1. Add 300µL pre-filtered lysate

354

Improvement of the cycle life of composite xerogel V2O5/C in aqueous LiNO3 solution by addition of vinylene carbonate  

NASA Astrophysics Data System (ADS)

The xerogel V2O5/C composite was synthesized by a sol-gel method, using the suspension of carbon black in the solution of crystalline V2O5 in hydrogen peroxide as the precursor solution. The Li+ intercalation/deintercalation reactions of the xerogel V2O5/C composite, used as an anode material of a two-electrode cell with an aqueous LiNO3 solution as the electrolyte, was studied before and after the addition of vinylene carbonate (VC). Upon addition of vinylene carbonate in an amount of only l wt %, the coulombic capacity during galvanostatic cycling, instead of commonly observed permanent fade, displayed an initial increase and then a stable plateau.

Stojkovi?, I.; Cvijeti?anin, N.; Mentus, S.

2011-12-01

355

Removal of heavy metal ions from aqueous solutions using carbon aerogel as an adsorbent.  

PubMed

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 behaviour of metal ions on carbon aerogel satisfies not only the Langmuir assumptions but also the Freundlich assumptions, i.e. multilayer formation on the surface of the adsorbent with an exponential distribution of site energy. The applicability of the Lagergren kinetic model has also been investigated. Thermodynamic constant (K(ad)), standard free energy (DeltaG(0)), enthalpy (DeltaH(0)) and entropy (DeltaS(0)) were calculated for predicting the nature of adsorption. The results indicate the potential application of this method for effluent treatment in industries and also provide strong evidence to support the adsorption mechanism proposed. PMID:15878798

Meena, Ajay Kumar; Mishra, G K; Rai, P K; Rajagopal, Chitra; Nagar, P N

2005-06-30

356

Binding of coagulation factor XI to washed human platelets  

SciTech Connect

The binding of human coagulation factor XI to washed human platelets was studied in the presence of zinc ions, calcium ions, and high molecular weight kininogen. Significant factor XI binding occurred at physiological levels of these metal ions when high molecular weight kininogen was present. Binding required platelet stimulation and was specific, reversible, and saturable. Scatchard analysis of the binding yielded approximately 1500 binding sites per platelet with an apparent dissociation constant of approximately 10 nM. Since the concentration of factor XI in plasma is about 25 nM, this suggests that in plasma factor XI binding sites on stimulated platelets might be saturated. Calcium ions and high molecular weight kininogen acted synergistically to enhance the ability of low concentrations of zinc ions to promote factor XI binding. The similarity between the concentrations of metal ions optimal for factor XI binding and those optimal for high molecular weight kininogen binding, as well as the ability of high molecular weight kininogen to modulate these metal ion effects, implies that factor XI and high molecular weight kininogen may form a complex on the platelet surface as they do in solution and on artificial negatively charged surfaces.

Greengard, J.S.; Heeb, M.J.; Ersdal, E.; Walsh, P.N.; Griffin, J.H.

1986-07-01

357

Excess molar enthalpies for mixtures of supercritical carbon dioxide and water + ethanol solutions  

Microsoft Academic Search

Excess molar enthalpies (H E m) for mixtures of supercritical CO2 and ethanol aqueous solutions were measured at 323.15 K and 7.64 and 15.00 MPa using an isothermal high-pressure flow calorimeter. H E m values obtained at the lower pressure are very exothermic while those obtained at the higher pressure are moderately endothermic. H E m for CO2 +H 2O

Eduardo P; Yolanda S ´ anchez-Vicente; Albertina Caba; Juan A. R. Renuncio

2005-01-01

358

Chemical Absorption of Carbon Dioxide into Aqueous Colloidal Silica Solution with Diethanolamine  

Microsoft Academic Search

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

2006-01-01

359

Studies of adsorption equilibria and kinetics in the systems: Aqueous solution of dyes-mesoporous carbons  

NASA Astrophysics Data System (ADS)

Two carbonaceous materials were synthesized by using the method of impregnation of mesoporous silicas obtained by applying the Pluronic copolymers as pore-creating agents. The isotherms of adsorption of methylene blue and methyl orange from aqueous solutions were measured by the static method. The profiles of adsorbate concentration change in time were obtained from the UV-vis spectra. The adsorption isotherms and kinetic dependence were discussed in the terms of theory of adsorption on heterogeneous surfaces.

Derylo-Marczewska, A.; Marczewski, A. W.; Winter, Sz.; Sternik, D.

2010-06-01

360

Capacitive deionization of NH{sub 4}CIO{sub 4} solutions with carbon aerogel electrodes. Revision 1  

SciTech Connect

A process for capacitive deionization of water with a stack of carbon aerogel electrodes was developed. 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 NH{sub 4}ClO{sub 4} is pumped through the electrochemical cell. After polarization, NH{sub 4}{sup +} and ClO{sub 4}{sup -} ions are removed from the water by the imposed electric field and trapped in the extensive cathodic and anodic double layers. Thsi process produces one stream of purified water and a second stream of concentrate. Effects of cell voltage, salt concentration, and cycling on electrosorption capacity were studied and results reported.

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

1996-01-01

361

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)

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.

Chang, Shenteng; Lu, Chungsying; Lin, Kun-Yi Andrew

2015-01-01

362

Impact of pressure, salt concentration, and temperature on the convective dissolution of carbon dioxide in aqueous solutions.  

PubMed

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

Loodts, V; Rongy, L; De Wit, A

2014-12-01

363

Superhydrophobic and conductive properties of carbon nanotubes/polybenzoxazine nanocomposites coated ramie fabric prepared by solution-immersion process  

NASA Astrophysics Data System (ADS)

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.

Zhang, Tao; Yan, Hongqiang; Fang, Zhengping; E, Yuping; Wu, Tao; Chen, Fei

2014-08-01

364

Corrosion behavior of aluminum doped diamond-like carbon thin films in NaCl aqueous solution.  

PubMed

Aluminum doped diamond-like carbon (DLC:Al) thin films were deposited on n-Si(100) substrates by co-sputtering a graphite target under a fixed DC power (650 W) and an aluminum target under varying DC power (10-90 W) at room temperature. The structure, adhesion strength and surface morphology of the DLC:Al films were characterized by X-ray photoelectron spectroscopy (XPS), micro-scratch testing and atomic force microscopy (AFM), respectively. The corrosion performance of the DLC:Al films was investigated by means of potentiodynamic polarization testing in a 0.6 M NaCl aqueous solution. The results showed that the polarization resistance of the DLC:Al films increased from about 18 to 30.7 k(omega) though the corrosion potentials of the films shifted to more negative values with increased Al content in the films. PMID:21128496

Khun, N W; Liu, E

2010-07-01

365

Whole-leaf wash improves chlorine efficacy for microbial reduction and prevents pathogen cross-contamination during fresh-cut lettuce processing.  

PubMed

Currently, most fresh-cut processing facilities in the United States use chlorinated water or other sanitizer solutions for microbial reduction after lettuce is cut. Freshly cut lettuce releases significant amounts of organic matter that negatively impacts the effectiveness of chlorine or other sanitizers for microbial reduction. The objective of this study is to evaluate whether a sanitizer wash before cutting improves microbial reduction efficacy compared to a traditional postcutting sanitizer wash. Romaine lettuce leaves were quantitatively inoculated with E. coli O157:H7 strains and washed in chlorinated water before or after cutting, and E. coli O157:H7 cells that survived the washing process were enumerated to determine the effectiveness of microbial reduction for the 2 cutting and washing sequences. Whole-leaf washing in chlorinated water improved pathogen reduction by approximately 1 log unit over traditional cut-leaf sanitization. Similar improvement in the reduction of background microflora was also observed. Inoculated "Lollo Rossa" red lettuce leaves were mixed with noninoculated Green-Leaf lettuce leaves to evaluate pathogen cross-contamination during processing. High level (96.7% subsamples, average MPN 0.6 log CFU/g) of cross-contamination of noninoculated green leaves by inoculated red leaves was observed when mixed lettuce leaves were cut prior to washing in chlorinated water. In contrast, cross-contamination of noninoculated green leaves was significantly reduced (3.3% of subsamples, average MPN washed in chlorinated water before cutting. This result suggests that whole-leaf sanitizing washes could be a practical strategy for enhancing the efficacy of chlorine washes for pathogen reduction and cross-contamination prevention. PMID:20629885

Nou, Xiangwu; Luo, Yaguang

2010-06-01

366

Extraction agents for the removal of polycyclic aromatic hydrocarbons (PAHs) from soil in soil washing technologies.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) in soil have been recognised as a serious health and environmental issue due to their carcinogenic, mutagenic and teratogenic properties. One of the commonly employed soil remediation techniques to clean up such contamination is soil washing or solvent extraction. The main factor which governs the efficiency of this process is the solubility of PAHs in the extraction agent. Past field-scale soil washing treatments for PAH-contaminated soil have mainly employed organic solvents or water which is either toxic and costly or inefficient in removing higher molecular weight PAHs. Thus, the present article aims to provide a review and discussion of the alternative extraction agents that have been studied, including surfactants, biosurfactants, microemulsions, natural surfactants, cyclodextrins, vegetable oil and solution with solid phase particles. These extraction agents have been found to remove PAHs from soil at percentages ranging from 47 to 100% for various PAHs. PMID:24100092

Lau, Ee Von; Gan, Suyin; Ng, Hoon Kiat; Poh, Phaik Eong

2014-01-01

367

Effects of partial oxidation of PMAN carbon on their performance as anodes in 1M LiPF{sub 6}/EC-DMC solutions  

SciTech Connect

A study was undertaken to examine the effects of partial oxidation on the electrochemical performance of carbons derived from poly(methylacrylonitrile) (PMAN)-divinylbenzene (DVB) co-polymers. Mild oxidation was examined as a possible technique to increase the reversible capacity, improve cycleability, and reduce the amount of irreversible capacity associated with the formation of the passivation layer during the first reduction. Oxidizing conditions involved treatment of the PMAN carbon prepared at 700 C with dry CO{sub 2} or with steam at 600 C for one hour. The effects on the performance in 1M LiPF{sub 6}/ethylene carbonate (EC)-dimethyl carbonate (DMC) solutions were evaluated by galvanostatic cycling tests, complex-impedance spectroscopy, and, to a more limited extent, cyclic voltammetry. Partial oxidation of PMAN carbon showed little or no overall beneficial effects in performance relative to the control.

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

1996-12-31

368

A feasibility study of the preparation of (U,Gd) 3O 8 solid solutions by thermal decomposition of co-precipitated carbonate mixtures  

NASA Astrophysics Data System (ADS)

Co-precipitation from equimolar nitrate solutions of uranium (VI) and gadolinium has been used to obtain a mixture of (NH 4) 4UO 2(CO 3) 3 and Gd 2(CO 3) 3 · 3H 2O at a pre-determined composition. Simultaneous measurements by TG, DTA and evolved gas analysis (EGA) showed that a calcination temperature of 700°C was necessary to decompose the carbonate completely to oxides. X-ray diffraction data indicated that a solid solution of Gd 2O 3 in U 3O 8 cannot be obtained by heating the carbonate mixtures up to 800°C in inert atmospheres.

Ravindran, P. V.; Rajagopalan, K. V.; Mathur, P. K.

1998-11-01

369

Utilization of various agricultural wastes for activated carbon preparation and application for the removal of dyes and metal ions from aqueous solutions.  

PubMed

Activated carbons were prepared from the agricultural solid wastes, silk cotton hull, coconut tree sawdust, sago waste, maize cob and banana pith and used to eliminate heavy metals and dyes from aqueous solution. Adsorption of all dyes and metal ions required a very short time and gave quantitative removal. Experimental results show all carbons were effective for the removal of pollutants from water. Since all agricultural solid wastes used in this investigation are freely, abundantly and locally available, the resulting carbons are expected to be economically viable for wastewater treatment. PMID:12733586

Kadirvelu, K; Kavipriya, M; Karthika, C; Radhika, M; Vennilamani, N; Pattabhi, S

2003-03-01

370

Effects of solution chemistry on adsorption of selected pharmaceuticals and personal care products (PPCPs) by graphenes and carbon nanotubes.  

PubMed

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

Liu, Fei-fei; Zhao, Jian; Wang, Shuguang; Du, Peng; Xing, Baoshan

2014-11-18

371

ELECTROCHEMICAL STUDIES ON THE CORROSION OF CARBON STEEL IN OXALIC ACID CLEANING SOLUTIONS  

SciTech Connect

The Savannah River Site (SRS) will disperse or dissolve precipitated metal oxides as part of radioactive waste tank closure operations. Previously SRS has utilized oxalic acid to accomplish this task. Since the waste tanks are constructed of carbon steel, a significant amount of corrosion may occur. Although the total amount of corrosion may be insignificant for a short contact time, a significant amount of hydrogen may be generated due to the corrosion reaction. Linear polarization resistance and anodic/cathodic polarization tests were performed to investigate the corrosion behavior during the process. The effect of process variables such as temperature, agitation, aeration, sample orientation, light as well as surface finish on the corrosion behavior were evaluated. The results of the tests provided insight into the corrosion mechanism for the iron-oxalic acid system.

Wiersma, B; John Mickalonis, J

2007-10-08

372

Removal of copper from aqueous solution by carbon nanotube/calcium alginate composites.  

PubMed

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 by calcium alginate (CNTs/CA) was prepared. Its copper adsorption properties were investigated via equilibrium studies. Experimental results showed that copper removal efficiency of CNTs/CA is high and reaches 69.9% even at a lower pH of 2.1. The copper adsorption capacity of CNTs/CA can attain 67.9 mg/g at copper equilibrium concentration of 5mg/L. PMID:20083351

Li, Yanhui; Liu, Fuqiang; Xia, Bing; Du, Qiuju; Zhang, Pan; Wang, Dechang; Wang, Zonghua; Xia, Yanzhi

2010-05-15

373

Synthesis and electroplating of high resolution insulated carbon nanotube scanning probes for imaging in liquid solutions  

PubMed Central

High resolution and isolated scanning probe microscopy (SPM) is in demand for continued development of energy storage and conversion systems involving chemical reactions at the nanoscale as well as an improved understanding of biological systems. Carbon nanotubes (CNTs) have large aspect ratios and, if leveraged properly, can be used to develop high resolution SPM probes. Isolation of SPM probes can be achieved by deposited a dielectric film and selectively etching at the apex of the probe. In this paper the fabrication of a high resolution and isolated SPM tip is demonstrated using electron beam induced etching of a dielectric film deposited onto an SPM tip with an attached CNT at the apex. PMID:22433664

Roberts, N.A.; Noh, J.H.; Lassiter, M.G.; Guo, S.; Kalinin, S.V.; Rack, P.D.

2012-01-01

374

Adsorption of Cu(2+) and methyl orange from aqueous solutions by activated carbons of corncob-derived char wastes.  

PubMed

Corncob-derived char wastes (CCW) obtained from biomass conversion to syngas production through corncob steam gasification, which were often discarded, were utilized for preparation of activated carbon by calcination, and KOH and HNO3 activation treatments, on the view of environment protection and waste recycling. Their adsorption performance in the removal of heavy metal ions and dye molecules from wastewater was evaluated by using Cu(2+) and methyl orange (MO) as the model pollutant. The surface and structure characteristics of the CCW-based activated carbons (CACs) were investigated by N2 adsorption, CO2 adsorption, FT-IR, and He-TPD. The adsorption capacity varied with the activation methods of CACs and different initial solution concentrations, indicating that the adsorption behavior was influenced by not only the surface area and porosity but also the oxygen functional groups on the surface of the CACs. The equilibrium adsorption data were analyzed with the Langmuir, Freundlich, and Temkin isotherm models, and the adsorption kinetics was evaluated by the pseudo-first-order and pseudo-second-order models. PMID:23666685

Hou, Xiao-Xu; Deng, Qing-Fang; Ren, Tie-Zhen; Yuan, Zhong-Yong

2013-12-01

375

Removal of direct blue-86 from aqueous solution by new activated carbon developed from orange peel.  

PubMed

The use of low-cost, easy obtained, high efficiency and eco-friendly adsorbents has been investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. This study investigates the potential use of activated carbon prepared from orange peel for the removal of direct blue-86 (DB-86) (Direct Fast Turquoise Blue GL) dye from simulated wastewater. The effects of different system variables, adsorbent dosage, initial dye concentration, pH and contact time were studied. The results showed that as the amount of the adsorbent increased, the percentage of dye removal increased accordingly. Optimum pH value for dye adsorption was determined as approximately 2.0. Maximum dye was sequestered within 30min after the beginning for every experiment. The adsorption of direct blue-86 followed a pseudo-second-order rate equation and fit well Langmuir, Tempkin and Dubinin-Radushkevich (D-R) equations better than Freundlich and Redlich-Peterson equations. The maximum removal of direct blue-86 was obtained at pH 2 as 92% for adsorbent dose of 6gL(-1) and 100mgL(-1) initial dye concentration at room temperature. The maximum adsorption capacity obtained from Langmuir equation was 33.78mgg(-1). Furthermore, adsorption kinetics of DB-86 was studied and the rate of adsorption was found to conform to pseudo-second-order kinetics with a good correlation (R2>0.99) with intraparticle diffusion as one of the rate determining steps. Activated carbon developed from orange peel can be attractive options for dye removal from diluted industrial effluents since test reaction made on simulated dyeing wastewater show better removal percentage of DB-86. PMID:18455301

Nemr, Ahmed El; Abdelwahab, Ola; El-Sikaily, Amany; Khaled, Azza

2009-01-15

376

Experimental study of the constituents of space wash water  

NASA Technical Reports Server (NTRS)

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.

Putnam, D. F.; Colombo, G. V.

1975-01-01

377

Molecular properties and intermolecular forces--factors balancing the effect of carbon surface chemistry in adsorption of organics from dilute aqueous solutions.  

PubMed

Presented paper recapitulates the results of 6 years' study concerning the effect of carbon surface chemical composition on adsorption of paracetamol, phenol, acetanilide, and aniline from dilute aqueous solutions on carbons. Adsorption-desorption isotherms, enthalpy, and kinetics of adsorption data are shown for the measurements performed at three temperatures (300, 310, and 320 K) at two pH levels (1.5 and 7) on commercial activated carbons. The data were obtained for four carbons: the initial carbon D43/1 and forms modified by applying concentrated HNO3, fuming H2SO4, and gaseous NH3. The modification procedures do not change the porosity in a drastic way, but lead to drastic changes of the composition of carbon surface layer. By applying MOPAC (a general-purpose semiempirical molecular orbital package), the physicochemical constants characterizing the molecules of adsorbates are calculated, including the distribution of the Mulliken charges, the dipole moments and ionization potentials, and the energies of interaction with the unique positive and negative charges. They are correlated with the parameters characterizing the adsorption (and kinetics) process of studied molecules on the mentioned above carbons. The mechanisms proposed in the literature for the description of adsorption from dilute aqueous solutions are verified, and a general mechanism of adsorption is proposed. PMID:15158374

Terzyk, Artur P

2004-07-01

378

On the influence of additives in electrolyte solutions on the electrochemical behavior of carbon/LiCoO 2 cells at elevated temperatures  

NASA Astrophysics Data System (ADS)

In this paper, we studied the influence of some organic additives in electrolyte solutions based on alkyl carbonate mixtures and LiPF 6 on the charge-discharge cycling characteristics of Li-ion cells at elevated temperatures (up to 60 °C). These additives were tested in relation to their impact on the electrochemical responses of both lithium-carbon and lithiated cobalt oxide electrodes. The additives chosen belong to organic compounds such as siloxanes, strained olefins, alkoxysilanes, and vinyl ethers. The main findings are as follows: the impedance of carbon and LiCoO 2 electrodes is smaller in solutions containing additive AD1 (hexamethyldisiloxane) from the siloxane family. Both Li/LiCoO 2 and carbon/LiCoO 2 cells exhibited much more stable charge-discharge cycling at 60 °C in the siloxane-containing solutions than in additive-free solutions. XPS analysis of LiCoO 2 electrodes cycled in the solution containing the additives indicated that their surface chemistry is strongly modified by the presence of siloxanes, even at low concentration.

Markovsky, Boris; Nimberger, Alex; Talyosef, Yossi; Rodkin, Alexander; Belostotskii, Anatoly M.; Salitra, Gregory; Aurbach, Doron; Kim, Hyeong-Jin

379

Ultrafast studies of organometallic photochemistry: The mechanism of carbon-hydrogen bond activation in solution  

SciTech Connect

When certain organometallic compounds are photoexcited in room temperature alkane solution, they are able to break or activate the C-H bonds of the solvent. Understanding this potentially practical reaction requires a detailed knowledge of the entire reaction mechanism. Because of the dynamic nature of chemical reactions, time-resolved spectroscopy is commonly employed to follow the important events that take place as reactants are converted to products. For the organometallic reactions examined here, the electronic/structural characteristics of the chemical systems along with the time scales for the key steps in the reaction make ultrafast UV/Vis and IR spectroscopy along with nanosecond Step-Scan FTIR spectroscopy the ideal techniques to use for this study. An initial study of the photophysics of (non-activating) model metal carbonyls centering on the photodissociation of M(CO){sub 6} (M = Cr, W, Mo) was carried out in alkane solutions using ultrafast IR spectroscopy. Next, picosecond UV/vis studies of the C-H bond activation reaction of Cp{sup *}M(CO){sub 2} (M = Rh, Ir), conducted in room temperature alkane solution, are described in an effort to investigate the origin of the low quantum yield for bond cleavage ({approximately}1%). To monitor the chemistry that takes place in the reaction after CO is lost, a system with higher quantum yield is required. The reaction of Tp{sup *}Rh(CO){sub 2} (Tp{sup *} = HB-Pz{sub 3}{sup *}, Pz{sup *} = 3,5-dimethylpyrazolyl) in alkanes has a quantum yield of {approximately}30%, making time resolved spectroscopic measurements possible. From ultrafast IR experiments, two subsequently formed intermediates were observed. The nature of these intermediates are discussed and the first comprehensive reaction mechanism for a photochemical C-H activating organometallic complex is presented.

Bromberg, S.E.

1998-05-01

380

Flexible carbon nanotube-polymer composite films with high conductivity and superhydrophobicity made by solution process.  

PubMed

CNT/Nafion nanocomposite film made by solution process exhibits high conductivity and superhydrophobicity. The highest water contact angle reaches 165.3 +/- 1.9 degrees. The wettability of the film can be controlled by simply varying the filtering rate and the content ratio of Nafion to CNT. We also develop a novel optical method to directly observe the air-solid-liquid interface for the first time. The extraordinary mechanical strength provided by the polymer helps the film retain its conductivity and superhydrobicity after 1000 bending cycles. PMID:19367804

Luo, Chan; Zuo, Xiaolei; Wang, Lei; Wang, Ergang; Song, Shiping; Wang, Jing; Wang, Jian; Fan, Chunhai; Cao, Yong

2008-12-01

381

Simple spectrophotometric determination of total carbonate by re-extraction via ligand exchange using chloroform solutions of uranyl quinolin-8-olate  

SciTech Connect

A method based on the decoloration of dilute chloroform solutions of uranyl quinoline-8-olate by shaking with aqueous solution of anions is proposed for the spectrophotometric determination of carbonate. The effects of several variables on the decoloration (pH, shaking time, volume ratio, etc.) were established. The spectral stability of an organic solution of the metal chelate is increased with an excess of quinolin-8-ol in the organic phase, and it avoids its stripping with water. The decoloration of chloroformic solutions varies linearly with the carbonate concentration between 10 and 50 ..mu..g x ml/sup -1/ in the aqueous phase (apparent molar absorptivity is found to be 2.03 x 10/sup 3/ l.mol/sup -1/.cm/sup -1/ at 390 nm). Interferences of many foreign ions (cations and anions) are also established. The method is relatively free from anion interferences.

Galindo Riano, M.D.; Garcia Vargas, M.; Munoz Leyva, J.A.

1988-04-01

382

Laboratory and pilot scale soil washing of PAH and arsenic from a wood preservation site: changes in concentration and toxicity.  

PubMed

Soil washing of a soil with a mixture of both polycyclic aromatic hydrocarbons (PAH) and As was evaluated in laboratory and pilot scale, utilizing both single and mixtures of different additives. The highest level of decontamination was achieved with a combination of 0.213 M of the chelating agent MGDA and 3.2 x CMC* of a non-ionic, alkyl glucoside surfactant at pH 12 (Ca(OH)(2)). This combination managed to reach Swedish threshold values within 1 0 min of treatment when performed at elevated temperature (50 degrees C), with initial contaminant concentrations of As=105+/-4 mg/kg and US-EPA PAH(16)=46.0+/-2.3mg/kg. The main mechanisms behind the removal were the pH effect for As and a combination of SOM ionization as a result of high pH and micellar solubilization for PAHs. Implementation of the laboratory results utilizing a pilot scale equipment did not improve the performance, which may be due to the shorter contact time between the washing solution and the particles, or changes in physical characteristics of the leaching solution due to the elevated pressure utilized. The ecotoxicological evaluation, Microtox, demonstrated that all soil washing treatments increased the toxicity of soil leachates, possibly due to increased availability of contaminants and toxicity of soil washing solutions to the test organism. PMID:19699582

Elgh-Dalgren, Kristin; Arwidsson, Zandra; Camdzija, Aida; Sjöberg, Ragnar; Ribé, Veronica; Waara, Sylvia; Allard, Bert; von Kronhelm, Thomas; van Hees, Patrick A W

2009-12-30

383

Physical, thermodynamics, and transport properties for carbon dioxide and nitrous oxide in solutions of diethanolamine or di-2-propanolamine in polyethylene glycol  

Microsoft Academic Search

Several properties important for the absorption of carbon dioxide and nitrous oxide in solutions of diethanolamine (DEA) or di-2-propanolamine (DIPA) and polyethylene glycol (PEG 400, average molecular weight 400) were determined experimentally. These properties include the density and viscosity of the amine-PEG 400 solutions, the physical solubility and diffusivity of CO[sub 2] in PEG 400, and the physical solubility and

Richard A. Davis; Ronald E. Menendez; Orville C. Sandall

1993-01-01

384

Comparison of photoluminescence of carbon nanotube/ZnO nanostructures synthesized by gas- and solution-phase transport  

NASA Astrophysics Data System (ADS)

Multiwalled carbon nanotubes (MWCNTs)/ZnO heterostructures were synthesized by two different processes: (1) gas-phase transport (GPT) and nucleation of Zn powders and (2) solution-phase transport (SPT) chemical reaction of zinc nitrate solution on the MWCNTs. Transmission electron microscopy and X-ray diffraction analysis indicated that the ZnO nanostructures on the MWCNTs from the GPT and SPT processes were poly- and single-crystal hexagonal wurtzite structure, respectively. The major photoluminescence (PL) spectra of our MWCNT/ZnO hybrid, excited at 380 nm and 550 nm, were presented. The PL intensity of the MWCNT/ZnO coaxial nanostructures behaves differently depending on the ZnO synthesis methods on the MWCNTs. The MWCNT/ZnO heterostructures synthesized using the GPT process were more efficient than those synthesized by SPT process in enhancing the PL intensity around the near-band-edge emission region. However, the emission enhancement around defect region was mostly attributed to increase in the O vacancy concentration in the ZnO on the MWCNTs during the SPT process.

Jin, Changhyun; Lee, Seawook; Kim, Chang-Wan; Park, Suyoung; Lee, Chongmu; Lee, Dongjin

2015-02-01

385

Preparation of carbon microspheres decorated with silver nanoparticles and their ability to remove dyes from aqueous solution.  

PubMed

Solid, but not hollow or porous, carbon microspheres decorated with silver nanoparticles (AgNP-CMSs) were prepared from silver nitrate and CMSs by a redox reaction at room temperature. The CMSs and AgNP-CMSs were characterized using X-ray diffraction, scanning electron microscopy, field emission scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and UV-vis spectrophotometry. Though with non-high specific surface area, the AgNP-CMSs exhibited a high adsorption capacity toward methylene blue (MB) in an aqueous solution. The AgNP-CMSs were able to remove all the MB from a solution of 30mg/L MB in water within 1min when the adsorbent concentration was 0.12g/L. The AgNP-CMSs also exhibited good adsorption and photocatalytic activity in the decomposition of aqueous Rhodamine B as well as MB under visible light. FTIR was used to examine the interaction between AgNP-CMSs and MB, and the spectrum and more extra experiments suggest ionic interactions between cationic dyes and the negatively charged groups can be formed but not the presence of abundant ?-? conjugations between dye molecules and the aromatic rings. The origin of the photocatalytic activity of AgNP-CMSs was attributed to a surface plasmon resonance (SPR) effect of the silver nanoparticles on the CMSs. PMID:25278157

Chen, Qingchun; Wu, Qingsheng

2015-02-11

386

Picosecond coherent anti-Stokes Raman scattering (CARS) study of vibrational dephasing of carbon disulfide and benzene in solution  

NASA Technical Reports Server (NTRS)

The vibrational dephasing of the 656/cm mode (nu1, a1g) of CS2 and the 991/cm mode (nu2, a1g) of benzene have been studied as a function of concentration in mixtures with a number of solvents using a ps time-resolved CARS technique. This technique employs two tunable synchronously-pumped mode-locked dye lasers in a stimulated Raman pump, coherent anti-Stokes Raman probe time-resolved experiment. Results are obtained for CS2 in carbon tetrachloride, benzene, nitrobenzene, and ethanol and for benzene nu2 in CS2. The dephasing rates of CS2 nu1 increase on dilution with the polar solvents and decrease or remain constant on dilution with the nonpolar solvents. The CS2/benzene solutions show a contrasting behavior, with the CS2 nu1 dephasing rate being nearly independent of concentration whereas the benzene nu2 dephasing rate decreases on dilution. These results are compared to theoretical models for vibrational dephasing of polyatomic molecules in solution.

Perry, Joseph W.; Woodward, Anne M.; Stephenson, John C.

1986-01-01

387

Hyperfiltration wash water recovery subsystem - Design and test results. [for extended mission spacecraft such as space stations  

NASA Technical Reports Server (NTRS)

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.

Reysa, R. P.; Price, D. F.; Olcott, T.; Gaddis, J. L.

1983-01-01

388

[Ex-situ remediation of PAHs contaminated site by successive methyl-beta-cyclodextrin enhanced soil washing].  

PubMed

Polycyclic aromatic hydrocarbon (PAH) polluted sites caused by abandoned coking plants have attracted great attentions. This study investigated the feasibility of using methyl-beta-cyclodextrin (MCD) solution to enhance ex situ soil washing for extracting PAHs. Treatment with elevated temperature (50 degrees C) in combination with ultrasonication (35 kHz, 30 min) at 100 g x L(-1) was effective. It was found that 96.7% +/- 2.4% of 3-ring PAH, 89.7% +/- 3.2% of 4-ring PAH, 76.3% +/- 2.2% of 5 (+6)-ring PAH and 91.3% +/- 3.1% of total PAHs were removed from soil after five successive washing cycles. The desorption kinetics of PAHs from contaminated soil was determined before and after successive washings. The 400 h Tenax extraction of PAHs from soil was decreasing gradually with increasing washing times. Furthermore, the F(r), F(sl), k(r), k(sl) and k(vl) were significantly lower than those of CK (P < 0.01). Therefore, considering the removal efficiency and potential environmental risk after soil )ashing, successive washing three times was selected as a reasonable parameter. These results have practical implications for site risk assessment and cleanup strategies. PMID:23947066

Sun, Ming-Ming; Teng, Ying; Luo, Yong-Ming; Li, Zhen-Gao; Jia, Zhong-Jun; Zhang, Man-Yun

2013-06-01

389

Effects of water washing on removing organic residues in bottom ashes of municipal solid waste incinerators.  

PubMed

Due to their potential toxicity and odourous nature, the residual organics in municipal solid waste incinerators are recently gaining attention as an important issue of resources recovery apart from their complex mixture of organic counterpart. Studies of the organic fractions in municipal solid waste incinerator residues have been limited. In this study, extended solid-phase extraction of the water-washed bottom ash and liquid-phase extraction of the washing water were carried out with regard to bottom ash samples from three mass-burning incinerators in Taipei County (Taiwan) during four consecutive seasons of year 2008-2009. Supercritical fluid extraction and Soxtec extraction techniques along with GC-MS were successfully used to characterize the residual organics in weathered and washed bottom ashes. Supercritical fluid extraction provided the quantification of aliphatics and aromatic compounds such as hexanoic acid and benzaldehyde, respectively. Soxtec extraction was useful for qualitative analysis of aromatic and aliphatic groups in the ashes and many of which were odourous and toxic compounds. By mixing one unit weight (g) bottom ash with two unit volume (mL) water for 15 min, total organic carbon in the bottom ash was greatly reduced (e.g., from 4.1 to 1.8 wt.%). Among the removed were foul odour-causing compounds such as pyridine and quinoline derivatives, while some aromatic compounds such as 4-hydroxybenzaldehyde and low-molecular-weight aliphatics such as hexanoic acid remained. The results here suggest that washing with water can be an effective pre-treatment step for removing odour-causing and environmental concerned organics. PMID:21112610

Lin, Yen-Ching; Panchangam, Sri Chandana; Wu, Chung-Hsin; Hong, Pui-Kwan Andy; Lin, Cheng-Fang

2011-01-01

390

Appraisal of guidelines for pre-operative body wash.  

PubMed

The pre-operative body wash is a strategy for reducing post-operative infection. However, there is a lack of knowledge about its importance. The purpose of the present study was to evaluate the quality of guidelines for the pre-operative body wash using the AGREE instrument--35 guidelines containing instructions for the pre-operative body wash or preparation were included. The AGREE instrument was employed to establish a quality assessment framework that facilitated a comparison of the guidelines. The results were based on the six domains of the AGREE instrument, all of which were found to have low adherence. Descriptive statistics were used to present the assessment score. The AGREE instrument is useful for evaluating the quality of clinical guidelines. The development of evidence-based guidelines must include clinical activities. Further research is required to clarify the pre-operative body wash process and how it should be performed to reduce post-operative infection. PMID:25426523

Edström, Elisabet; Westerberg, Lisa; Henricson, Maria

391

6. VIEW OF THREE BEARS LAKE, SHOWING WASHED UP 12' ...  

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

6. VIEW OF THREE BEARS LAKE, SHOWING WASHED UP 12' x 12' DAM SUPPORT TIMBERS, LOOKING NORTHEAST FROM SOUTH SIDE OF LAKE - Three Bears Lake & Dams, North of Marias Pass, East Glacier Park, Glacier County, MT

392

7. CLOSEUP VIEW OF WASHED UP 12' x 12' DAM ...  

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

7. CLOSE-UP VIEW OF WASHED UP 12' x 12' DAM SUPPORT TIMBERS, THREE BEARS LAKE, LOOKING NORTHEAST FROM SOUTH SIDE OF LAKE - Three Bears Lake & Dams, North of Marias Pass, East Glacier Park, Glacier County, MT

393

PROC. ENTOMOL. SOC. WASH. 115(1), 2013, pp. 107109  

E-print Network

PROC. ENTOMOL. SOC. WASH. 115(1), 2013, pp. 107­109 NOTE DNA barcodes of caterpillars (Lepidoptera738369­JF739166). Lepidoptera methods: General field and laboratory methods for Lepidoptera are described

Weiblen, George D

394

View of Steel Flume Bridge #2 crossing over wash. Looking ...  

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

View of Steel Flume Bridge #2 crossing over wash. Looking downstream, southwest - Childs-Irving Hydroelectric Project, Childs System, Flume Bridge No. 2, Forest Service Road 708/502, Camp Verde, Yavapai County, AZ

395

19. Photocopy of circa 1839 ink and wash drawing by ...  

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

19. Photocopy of circa 1839 ink and wash drawing by Richard Upjohn in Avery Library, Columbia University EAST ELEVATION (above) AND SECOND-FLOOR PLAN (below) - Kingscote, Bellevue Avenue & Bowery Street, Newport, Newport County, RI

396

17. Photocopy of circa 1839 ink and wash drawing by ...  

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

17. Photocopy of circa 1839 ink and wash drawing by Richard Upjohn in Avery Library, Columbia University, New York, New York FRONT ELEVATION (below) AND REAR ELEVATION (above) - Kingscote, Bellevue Avenue & Bowery Street, Newport, Newport County, RI

397

Design for dissemination of a low cost washing machine  

E-print Network

Throughout much the developing world, laundry is done the same way today as it was thousands of years ago. The strenuous and time consuming task of clothes washing often falls on the women, who spend many hours every week ...

Raduta, Radu

2008-01-01

398

7. PRESSURE CONDUIT ACROSS SCHOOL HOUSE WASH ON THE POWER ...  

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

7. PRESSURE CONDUIT ACROSS SCHOOL HOUSE WASH ON THE POWER CANAL Photographer: Walter J. Lubken, February 21, 1906 - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

399

PARTS WASHING ALTERNATIVES STUDY - UNITED STATES COAST GUARD  

EPA Science Inventory

This report has been written to assist the United States Coast Guard (USCG) industrial managers in determining the most cost effective and environmentally acceptable parts washing alternatives for their specific applications. An; evaluation was conducted on four different cleane...

400

PARTS WASHING ALTERNATIVES STUDY - UNITED STATES COAST GUARD  

EPA Science Inventory

This report has been written to assist the United States Coast Guard (USCG) industrial managers in determining the most cost effective and environmentally acceptable parts washing alternatives for their specific applications. n evaluation was conducted on four different cleaners ...

401

Poly (vinylsulfonic acid) assisted synthesis of aqueous solution stable vaterite calcium carbonate nanoparticles.  

PubMed

Calcium carbonate nanoparticles of the vaterite polymorph were synthesized by combining CaCl2 and Na2CO3 in the presence of poly (vinylsulfonic acid) (PVSA). By studying the important experimental parameters we found that controlling PVSA concentration, reaction temperature, and order of reagent addition the particle size, monodispersity, and surface charge can be controlled. By increasing PVSA concentration or by decreasing temperature CCNPs with an average size from ?150 to 500 nm could be produced. We believe the incorporation of PVSA into the reaction plays a dual role to (1) slow down the nucleation rate by sequestering calcium and to (2) stabilize the resulting CCNPs as the vaterite polymorph, preventing surface calcification or aggregation into microparticles. The obtained vaterite nanoparticles were found to maintain their crystal structure and surface charge after storage in aqueous buffer for at least 5 months. The aqueous stable vaterite nanoparticles could be a useful platform for the encapsulation of a large variety of biomolecules for drug delivery or as a sacrificial template toward capsule formation for biosensor applications. PMID:24461857

Nagaraja, Ashvin T; Pradhan, Sulolit; McShane, Michael J

2014-03-15

402

The Dissolution of Synthetic Na-Boltwoodite in Sodium Carbonate Solutions  

SciTech Connect

Uranyl silicates such as uranophane and Na-boltwoodite appear to control the solubility of uranium in the contaminated sediments at the US Department of Energy Hanford site (Liu et al., 2004). Consequently, the solubility of synthetic Na-boltwoodite was determined over a wide range of bicarbonate concentrations, from circumneutral to alkaline pH, that are representative of porewater and groundwater compositions at the Hanford site. Results show that Na-boltwoodite dissolution was nearly congruent and its solubility increased with increasing bicarbonate concentration. Calculated solubility constants varied by nearly 2 log units from low bicarbonate (no added NaCO3) to 50 mmol/L bicarbonate. However, the solubility constants only vary by 0.5 log units from 0 added bicarbonate to 1.2 mmol/L bicarbonate, where logKsp = 5.39-5.92 and the average logKsp = 5.63. No systematic trend in logKsp was apparent over this range in bicarbonate concentrations. LogKsp values trended down with increasing bicarbonate concentration, where logKsp = 4.06 at 50 mmol/L bicarbonate. We conclude that the calculated solubility constants at high bicarbonate are compromised by an incomplete or inaccurate uranyl-carbonate speciation model.

Ilton, Eugene S.; Liu, Chongxuan; Yantasee, Wassana; Wang, Zheming; Moore, Dean A.; Felmy, Andrew R.; Zachara, John M.

2006-09-01

403

A summary of research and progress on carbon monoxide exposure control solutions on houseboats.  

PubMed

Investigations of carbon monoxide (CO-related poisonings and deaths on houseboats were conducted by the Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. These investigations measured hazardous CO concentrations on and around houseboats that utilize gasoline-powered generators. Engineering control devices were developed and tested to mitigate this deadly hazard. CO emissions were measured using various sampling techniques which included exhaust emission analyzers, detector tubes, evacuated containers (grab air samples analyzed by a gas chromatograph), and direct-reading CO monitors. CO results on houseboats equipped with gasoline-powered generators without emission controls indicated hazardous CO concentrations exceeding immediately dangerous to life and health (IDLH) levels in potentially occupied areas of the houseboat. Air sample results on houseboats that were equipped with engineering controls to remove the hazard were highly effective and reduced CO levels by over 98% in potentially occupied areas. The engineering control devices used to reduce the hazardous CO emissions from gasoline-powered generators on houseboats were extremely effective at reducing CO concentrations to safe levels in potentially occupied areas on the houseboats and are now beginning to be widely used. PMID:24568306

Hall, Ronald M; Earnest, G Scott; Hammond, Duane R; Dunn, Kevin H; Garcia, Alberto

2014-01-01

404

A Study on Stress Corrosion Cracking of X70 Pipeline Steel in Carbonate Solution by EIS  

NASA Astrophysics Data System (ADS)

In this study, electrochemical impedance spectroscopy (EIS) simultaneously with the slow strain rate testing were used to investigate the stress corrosion cracking (SCC) behavior of X70 pipeline steel in high pH bicarbonate solution at different applied potentials. Potentiostatic EIS tests were also conducted at certain times to determine the changes associated with the SCC. Circuit models for the cracking were proposed by the use of the potentiostatic EIS measurements at different applied potentials. Finally, the results of the potentiostatic EIS tests and the SSR tests showed the decline of the circuit element resistance by increasing the stress which was related to the cracking. It was also observed that the X70 pipeline steel was most susceptible to SCC at potential of -650 mV versus SCE.

Shahriari, A.; Shahrabi, T.; Oskuie, A. A.

2013-05-01

405

Note: Limitations of the optoelectronic control for carbon nanoparticles synthesis via arc-discharge in solution.  

PubMed

Submerged electric arc discharge in liquids has shown to be a promising method for synthesizing a wide variety of nanomaterials. However, it requires an accurate current stability control to ensure the desired purity and structure of the products. The discharge stability control through light emission has been previously studied, but still requires further investigation to clarify the influence of some parameters. The present work has studied the solution's transmittance variation over time, the correlation between the arc light emission and the arc current, and the feasibility of controlling the arc current by using a specific wavelength of the arc light spectrum. Several limitations of the optoelectronic control were found at low currents (I < 50 A). PMID:24689635

Darias-González, J G; Hernández-Tabares, L; Carrillo-Barroso, E; Ledo-Pereda, L M; Arteche-Díaz, J; Desdín-García, L F

2014-03-01

406

Note: Limitations of the optoelectronic control for carbon nanoparticles synthesis via arc-discharge in solution  

NASA Astrophysics Data System (ADS)

Submerged electric arc discharge in liquids has shown to be a promising method for synthesizing a wide variety of nanomaterials. However, it requires an accurate current stability control to ensure the desired purity and structure of the products. The discharge stability control through light emission has been previously studied, but still requires further investigation to clarify the influence of some parameters. The present work has studied the solution's transmittance variation over time, the correlation between the arc light emission and the arc current, and the feasibility of controlling the arc current by using a specific wavelength of the arc light spectrum. Several limitations of the optoelectronic control were found at low currents (I < 50 A).

Darias-González, J. G.; Hernández-Tabares, L.; Carrillo-Barroso, E.; Ledo-Pereda, L. M.; Arteche-Díaz, J.; Desdín-García, L. F.

2014-03-01

407

Controlled synthesis of calcium carbonate in a mixed aqueous solution of PSMA and CTAB  

SciTech Connect

A mixed system of poly (styrene-alt-maleic acid) (PSMA) and cetyltrimethylammonium bromide (CTAB) was used as a very effective crystal growth modifier to direct the controlled synthesis of CaCO{sub 3} crystals with various morphologies and polymorphs. The as-prepared products were characterized with scanning electron microscopy and X-ray diffraction. It was found that the concentrations and relative ratios of PSMA and CTAB in the mixed aqueous solution were turned out to be important parameters for the morphology and polymorph of CaCO{sub 3} crystals. Various morphologies of CaCO{sub 3} crystals, such as hollow microsphere, peanut and so on, were produced depending on the concentrations and relative ratios of PSMA and CTAB. Moreover, the formation mechanisms of CaCO{sub 3} crystals with different morphologies were discussed.

Yu Jiaguo [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, No. 122, Luoshi Road, Wuhan City, Hubei Province 430070 (China)]. E-mail: jiaguoyu@yahoo.com; Zhao Xiufeng [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, No. 122, Luoshi Road, Wuhan City, Hubei Province 430070 (China); Department of Chemical Engineering, Changji University, Changji 831100 (China); Cheng Bei [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, No. 122, Luoshi Road, Wuhan City, Hubei Province 430070 (China); Zhang Qingjie [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, No. 122, Luoshi Road, Wuhan City, Hubei Province 430070 (China)

2005-03-15

408

Recovery of soluble chloride salts from the wastewater generated during the washing process of municipal solid wastes incineration fly ash.  

PubMed

Water washing is widely used as the pretreatment method to treat municipal solid waste incineration fly ash, which facilitates the further solidification/stabilization treatment or resource recovery of the fly ash. The wastewater generated during the washing process is a kind of hydrosaline solution, usually containing high concentrations of alkali chlorides and sulphates, which cause serious pollution to environment. However, these salts can be recycled as resources instead of discharge. This paper explored an effective and practical recovery method to separate sodium chloride, potassium chloride, and calcium chloride salts individually from the hydrosaline water. In laboratory experiments, a simulating hydrosaline solution was prepared according to composition of the waste washing water. First, in the three-step evaporation-crystallization process, pure sodium chloride and solid mixture of sodium and potassium chlorides were obtained separately, and the remaining solution contained potassium and calcium chlorides (solution A). And then, the solid mixture was fully dissolved into water (solution B obtained). Finally, ethanol was added into solutions A and B to change the solubility of sodium, potassium, and calcium chlorides within the mixed solvent of water and ethanol. During the ethanol-adding precipitation process, each salt was separated individually, and the purity of the raw production in laboratory experiments reached about 90%. The ethanol can be recycled by distillation and reused as the solvent. Therefore, this technology may bring both environmental and economic benefits. PMID:25176491

Tang, Hailong; Erzat, Aris; Liu, Yangsheng

2014-01-01

409

WASH inhibits autophagy through suppression of Beclin 1 ubiquitination  

PubMed Central

Autophagy degrades cytoplasmic proteins and organelles to recycle cellular components that are required for cell survival and tissue homeostasis. However, it is not clear how autophagy is regulated in mammalian cells. WASH (Wiskott–Aldrich syndrome protein (WASP) and SCAR homologue) plays an essential role in endosomal sorting through facilitating tubule fission via Arp2/3 activation. Here, we demonstrate a novel function of WASH in modulation of autophagy. We show that WASH deficiency causes early embryonic lethality and extensive autophagy of mouse embryos. WASH inhibits vacuolar protein sorting (Vps)34 kinase activity and autophagy induction. We identified that WASH is a new interactor of Beclin 1. Beclin 1 is ubiquitinated at lysine 437 through lysine 63 linkage in cells undergoing autophagy. Ambra1 is an E3 ligase for lysine 63-linked ubiquitination of Beclin 1 that is required for starvation-induced autophagy. The lysine 437 ubiquitination of Beclin 1 enhances the association with Vps34 to promote Vps34 activity. WASH can suppress Beclin 1 ubiquitination to inactivate Vps34 activity leading to suppression of autophagy. PMID:23974797

Xia, Pengyan; Wang, Shuo; Du, Ying; Zhao, Zhenao; Shi, Lei; Sun, Lei; Huang, Guanling; Ye, Buqing; Li, Chong; Dai, Zhonghua; Hou, Ning; Cheng, Xuan; Sun, Qingyuan; Li, Lei; Yang, Xiao; Fan, Zusen

2013-01-01

410

Enthalpy of solution of carbon dioxide in (water + monoethanolamine, or diethanolamine, or N -methyldiethanolamine) and (water + monoethanolamine + N -methyldiethanolamine) at T = 298.15 K  

Microsoft Academic Search

Measurements of the enthalpy of solution for carbon dioxide in (water + monoethanolamine, or diethanolamine, or N -methyldiethanolamine) and in (water + monoethanolamine +N -methyldiethanolamine) at T= 298.15 K have been made by isothermal displacement calorimetry. The estimated uncertainty is between ±1 and 2 per cent. The results are compared with previous measurements made by isothermal flow calorimetry, isoperibol calorimetry

Alan E. Mather

2000-01-01

411

Comparison studies of surface cleaning methods for PAN-based carbon fibers with acetone, supercritical acetone and subcritical alkali aqueous solutions  

NASA Astrophysics Data System (ADS)

Four kinds of polyacrylonitrile-based carbon fibers were cleaned by three methods and were characterized by X-ray photoelectron spectroscopy, monofilament tensile strength test and atomic force microscopy (AFM). Experimental results of these tests reveal that the method using supercritical acetone or subcritical potassium hydroxide aqueous solution act as the processing medium shows a better cleaning effect compared to the traditional method, Soxhlet extraction with acetone. The method using supercritical acetone is more appropriate to wipe off the oxygenated contaminants on carbon fibers' surfaces and causes a relatively smaller damage to the bulk strength of each carbon fiber. As far as treating method using the subcritical alkali aqueous solution, it can thoroughly remove silicious contaminants on the surfaces of treated fibers.

Meng, Linghui; Fan, Dapeng; Huang, Yudong; Jiang, Zaixing; Zhang, Chunhua

2012-11-01

412

Washing the guilt away: effects of personal versus vicarious cleansing on guilty feelings and prosocial behavior.  

PubMed

For centuries people have washed away their guilt by washing their hands. Do people need to wash their own hands, or is it enough to watch other people wash their hands? To induce guilt, we had participants write about a past wrong they had committed. Next, they washed their hands, watched a washing-hands video, or watched a typing-hands video. After the study was over, participants could help a Ph.D. student complete her dissertation by taking some questionnaires home and returning them within 3 weeks. Results showed that guilt and helping behavior were lowest among participants who washed their hands, followed by participants who watched a washing-hands video, followed by participants who watched a typing-hands video. Guilt mediated the effects of cleansing on helping. These findings suggest that washing one's own hands, or even watching someone else wash their hands, can wash away one's guilt and lead to less helpful behavior. PMID:24616686

Xu, Hanyi; Bègue, Laurent; Bushman, Brad J

2014-01-01

413

Kinetics of removal of carbon dioxide by aqueous solutions of N,N-diethylethanolamine and piperazine.  

PubMed

N,N-Diethylethanolamine (DEEA) is a very promising absorbent for CO(2) removal from gaseous streams, as it can be prepared from renewable resources. Aqueous mixtures of DEEA and piperazine (PZ) are attractive for the enhancement of CO(2) capture, due to the high CO(2) loading capacity of DEEA and high reactivity of PZ. In the present work, for the first time, the equilibrium and kinetic characteristics of the CO(2) reaction with such mixtures were considered. Kinetic data were obtained experimentally, by using a stirred cell reactor. These data were interpreted using a homogeneous activation mechanism, by which the investigated reaction was considered as a reaction between CO(2) and DEEA in parallel with the reaction of CO(2) with PZ. It is found that, in the studied range of temperatures, 298-308 K, and overall amine concentrations, 2.1-2.5 kmol/m(3), this reaction system belongs to the fast pseudo-first-order reaction regime systems. The second-order rate constant for the CO0 reaction with PZ was determined from the absorption rate measurements in the activated DEEA solutions, and its value at 303 K was found to be 24,450 m(3)/(kmol s). PMID:20151656

Konduru, Prashanti B; Vaidya, Prakash D; Kenig, Eugeny Y

2010-03-15

414

Solubility of carbon dioxide and hydrogen sulfide in aqueous N-methyldiethanolamine solutions  

SciTech Connect

In this work, 72 new experimental solubility data points for H{sub 2}S and CO{sub 2} mixtures in aqueous N-methyldiethanol amine (MDEA) solutions at different methane partial pressures (up to 69 bara) are presented. They are correlated using an electrolyte equation of state (E-EOS) thermodynamic model. This model has already been used to estimate the CO{sub 2} solubility in aqueous MDEA (Huttenhuis et al. Fluid Phase Equilib. 2008, 264, 99-112) and the H{sub 2}S solubility in aqueous MDEA (Huttenhuis et al. Int. J. Oil, Gas Coal Technol. 2008, 1, 399-424). Here, the model is further extended to predict the behavior of CO{sub 2} and H{sub 2}S when they are present simultaneously in aqueous MDEA. The application of an equation of state is a new development for this type of system, i.e., of acid-gas-amine systems. The molecular interactions are described by Schwarzentruber et al.'s modification of the Redlich-Kwong-Soave equation of state, with terms added to account for ionic interactions in the liquid phase. The model is used to describe acid-gas solubility data for the CO{sub 2}-H{sub 2}S-MDEA-H{sub 2}O system reported in the open literature and experimental data reported here for the CO{sub 2}-H{sub 2}S-MDEA-H{sub 2}O-CH{sub 4} system.

Huttenhuis, P.J.G.; Agrawal, N.J.; Versteeg, G.F. [Procede Group BV, Enschede (Netherlands)

2009-04-15

415

Incorporation of Np(V) and U(VI) in carbonate and sulfate minerals crystallized from aqueous solution  

NASA Astrophysics Data System (ADS)

The neptunyl Np(V)O2+ and uranyl U(VI)O22+ ions are soluble in groundwater, although their interaction with minerals in the subsurface may impact their mobility. One mechanism for the immobilization of actinyl ions in the subsurface is co-precipitation in low-temperature minerals that form naturally, or that are induced to form as part of a remediation strategy. Important differences in the crystal-chemical behavior of the Np(V) neptunyl and U(VI) uranyl ions suggest their behavior towards incorporation into growing crystals may differ significantly. Using a selection of low-temperature minerals synthesized in aqueous systems under ambient conditions, this study examines the factors that impact the structural incorporation of the Np(V) neptunyl and U(VI) uranyl ions in carbonate and sulfate minerals. Calcite (CaCO3), aragonite (CaCO3), gypsum (CaSO4·2H2O), strontianite (SrCO3), cerussite (PbCO3), celestine (SrSO4), and anglesite (PbSO4) were synthesized from aqueous solutions containing either 400-1000 ppm of U(VI) or Np(V) relative to the divalent cation present in the system. The synthetic products were investigated by inductively coupled plasma mass spectrometry, luminescence and time resolved luminescence spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. Amongst the carbonate minerals, calcite significantly favors Np(V) incorporation over U(VI). U(VI) and Np(V) are incorporated in aragonite and strontianite in similar amounts, whereas cerussite did not incorporate either U(VI) or Np(V) under the synthesis conditions. The sulfate minerals weakly interact with the actinyl ions, relative to the carbonate minerals. Incorporation of U(VI) and Np(V) in celestine was observed at the level of a few tens of ppm; anglesite and gypsum did not incorporate detectable U(VI) or Np(V). Luminescence spectra of the uranyl incorporated in aragonite and strontianite are consistent with a uranyl unit coordinated by three bidentate CO32- groups. The time-resolved spectra of calcite indicate multiple coordination environments about the uranyl unit, with the spectra of the longer-lived components displaying similarities with uranyl-incorporated aragonite. The luminescence spectrum of uranyl-bearing celestine is consistent with a uranyl unit coordinated by monodentate sulfate groups. Anglesite synthesized in the presence of uranyl shows no luminescence, whereas the spectra of gypsum and cerussite suggest uranyl surface adsorption or precipitation of secondary uranyl minerals on the mineral surfaces. Our findings indicate that geometrical constraints of the Np(V) and U(VI) species in solution, together with the crystallographic steric constraints of the host material, affect preferential uptake in the mineral structures studied. Calcium and strontium appear to be favorable incorporation sites for both U(VI) and Np(V) in aragonite and strontianite. In calcite, Np(V) incorporation is strongly favored over U(VI), whereas in gypsum incorporation of neither actinyl ion occurs. Substitution of actinyl ions was also not observed for lead, in either the carbonate or sulfate minerals studied.

Balboni, Enrica; Morrison, Jessica M.; Wang, Zheming; Engelhard, Mark H.; Burns, Peter C.

2015-02-01

416

Modeling raindrop strike performance on copper wash-off from vine leaves.  

PubMed

Copper lost in foliar wash-off from vine leaves treated with Cu-based fungicides was analyzed with a single-drop rainfall simulator. The temporal losses of the particulate Cu (CuP) and the solution Cu (CuS) from raindrop strikes on leaves were modeled using a Poisson point process. This model estimated maximum detachment rates of 0.82 ng CuP and 0.033 ng CuS per raindrop. The total amount of Cu (CuT) in the leaves before rainfall ranged between 0.4 and 4.4 g Cu kg(-1) dry weight. Wash-off reduced the amount of CuT present in the leaves by 0.6 g kg(-1). Particulate losses of CuT ranged from 75 to 90%, while soluble losses of CuT ranged from 10 to 25%. The kinetic energy of the raindrops influenced the loss of CuS but not the loss of CuP. The Poisson point approach can provide an interesting starting point to model non-point source pollution produced from agricultural chemicals washed-off by rain. PMID:25560655

Pérez-Rodríguez, P; Soto-Gómez, D; López-Periago, J E; Paradelo, M

2015-03-01

417

Nuclear criticality safety evaluation -- DWPF Late Wash Facility, Salt Process Cell and Chemical Process Cell  

SciTech Connect

The Savannah River Site (SRS) High Level Nuclear Waste will be vitrified in the Defense Waste Processing Facility (DWPF) for long term storage and disposal. This is a nuclear criticality safety evaluation for the Late Wash Facility (LWF), the Salt Processing Cell (SPC) and the Chemical Processing Cell (CPC). of the DWPF. Waste salt solution is processed in the Tank Farm In-Tank Precipitation (ITP) process and is then further washed in the DWPF Late Wash Facility (LWF) before it is fed to the DWPF Salt Processing Cell. In the Salt Processing Cell the precipitate slurry is processed in the Precipitate Reactor (PR) and the resultant Precipitate Hydrolysis Aqueous (PHA) produce is combined with the sludge feed and frit in the DWPF Chemical Process Cell to produce a melter feed. The waste is finally immobilized in the Melt Cell. Material in the Tank Farm and the ITP and Extended Sludge processes have been shown to be safe against a nuclear criticality by others. The precipitate slurry feed from ITP and the first six batches of sludge feed are safe against a nuclear criticality and this evaluation demonstrates that the processes in the LWF, the SPC and the CPC do not alter the characteristics of the materials to compromise safety.

Williamson, T.G.

1994-10-17

418

Facilitated transport of carbon dioxide through supported liquid membranes of aqueous amine solutions  

SciTech Connect

A series of experiments on the facilitated transport of CO{sub 2} through supported liquid membranes containing monoethanolamine (MEA) and diethanolamine (DEA) was performed. The feed gas was a mixture of CO{sub 2} and CH{sub 4}, and the CO{sub 2} partial pressure p{sub CO{sub 2},F} was in the range from 0.05 to 0.97 atm. Compared to the MEA membranes, the DEA membranes showed a little higher permeation rate of CO{sub 2} since the equilibrium constant of the reaction between CO{sub 2} and MEA is too large for CO{sub 2} to be released to the receiving phase rapidly. When p{sub CO{sub 2},F} and the MEA concentration were 0.05 atm and 4 mol/dm{sup 3}, respectively, the separation factor {alpha}(CO{sub 2}/CH{sub 4}) was about 2,000. It was found that if the membrane thickness multiplied by the square root of the tortuosity factor of the microporous support membrane is used as the effective pore length, the experimentally observed permeation rates of CO{sub 2} can be satisfactorily simulated by the theory of facilitated transport of CO{sub 2} through aqueous amine membranes. A method for estimating the solubilities of CO{sub 2} in the membrane solutions from the permeation rates of CH{sub 4} was also proposed. It was also found that permeation rates of CO{sub 2} through aqueous DEA membranes reported by Guha et al. were quantitatively explained by the proposed theory.

Teramoto, Masaaki; Nakai, Katsuya; Ohnishi, Nobuaki; Huang, Q.; Watari, Takashi; Matsuyama, Hideto [Kyoto Inst. of Tech. (Japan). Dept. of Chemistry and Materials Technology] [Kyoto Inst. of Tech. (Japan). Dept. of Chemistry and Materials Technology

1996-02-01

419

Mechanisms controlling the production and transport of methane, carbon dioxide, and dissolved solutes within a boreal peatland. Progress report, January 15, 1991--July 14, 1992  

SciTech Connect

Peatlands are one of the most important terrestrial reservoirs in the global cycle for carbon, and are a major source for atmospheric methane. However, little is known about the dynamics of these carbon reservoirs or their feedback mechanisms with the pool of atmospheric CO{sub 2} during the Holocene. Specifically, it is unknown whether large peat basins are sources, sinks, or steady-state reservoirs for the global carbon cycle. In particular, the production and transport of methane, carbon dioxide, and dissolved organic carbon form the deeper portions of these peatlands is unknown. Our DOE research program is to conduct an integrated ecologic and hydrogeochemical study of the Glacial Lake Agassiz peatlands (northern Minnesota) to better understand the carbon dynamics in globally significant peat basins. Specifically, our study will provide local and regional data on (1), rates of carbon accumulation and loss and fluxes of methane in the peat profiles; (2) the physical and botanical factors controlling the production of methane and carbon dioxide in the wetland; and (3) the role of hydrogeologic processes in controlling the fluxes of gases and solutes through the peat. We intend to use computer simulation models, calibrated to field data, to scale-up from local to regional estimates of methane and carbon dioxide within the basin. How gases and dissolved organic carbon escapes form peatlands in unknown. It has been suggested that the concentrations of methane produced in the upper peat are sufficient to produce diffusion gradients towards the surface. Alternatively, gas may move through the peat profile by groundwater advection.

Siegel, D.I.

1992-04-09

420

Oviposition deterring influence of female body wash in tobacco beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae)  

Microsoft Academic Search

Oviposition responses of the tobacco beetle, Lasioderma serricorne (F.) were tested against the whole body washes of conspecific females. Five solvents were used for the body washings: distilled water, insect saline, methanol, acetone and hexane. All the body washes noticeably reduced egg laying in the treated samples more than those of their controls. Hexane wash was the most effective (about

A. J. Howlader; P. M. Ambadkar

1995-01-01

421

MD simulation of organics adsorption from aqueous solution in carbon slit-like pores. Foundations of the pore blocking effect.  

PubMed

The results of systematic studies of organics adsorption from aqueous solutions (at the neutral pH level) in a system of slit-like carbon pores having different sizes and oxygen groups located at the pore mouth are reported. Using molecular dynamics simulations (GROMACS package) the properties of adsorbent-adsorbate (benzene, phenol or paracetamol) as well as adsorbent-water systems are discussed. After the introduction of surface oxygen functionalities, adsorption of organic compounds decreases (in accordance with experimental data) and this is caused by the accumulation of water molecules at pore entrances. The pore blocking effect decreases with the diameter of slits and practically vanishes for widths larger than approx. 0.68 nm. We observed the increase in phenol adsorption with the rise in temperature. Moreover, adsorbed molecules occupy the external surface of the slit pores (the entrances) in the case of oxidized adsorbents. Among the studied molecules benzene, phenol and paracetamol prefer an almost flat orientation and with the rise in the pore width the number of molecules oriented in parallel decreases. The decrease or increase in temperature (with respect to 298 K) leads to insignificant changes of angular orientation of adsorbed molecules. PMID:24356213

Gauden, Piotr A; Terzyk, Artur P; Furmaniak, Sylwester; W?och, Jerzy; Kowalczyk, Piotr; Zieli?ski, Wojciech

2014-02-01

422

Salt-enhanced removal of 2-ethyl-1-hexanol from aqueous solutions by adsorption on activated carbon.  

PubMed

2-Ethyl-1-hexanol has extensive industrial applications in solvent extraction, however, in view of its potential pollution to environment, the removal and recovery of 2-ethyl-1-hexanol is considered an essential step toward its sustainable use in the future. In this work, we report the removal of 2-ethyl-1-hexanol from aqueous solutions containing salts in high concentrations by adsorption on a coal-based activated carbon. Adsorption thermodynamics showed that the experimental isotherms were conformed well to the Langmuir equation. Also it was found that inorganic salts, i.e. MgCl2 and CaCl2 in high concentration significantly enhanced the adsorption capacity from 223 mg/g in the deionized water to 277 mg/g in a saline water. This phenomenon of adsorption enhancement could be ascribed to the salt-out effect. Kinetic analysis indicated that adsorption kinetics follows the pseudo-second-order equation and the adsorption rate constants increase with the salt concentration. The dynamic breakthrough volume and adsorbed amount of 2-ethyl-1-hexanol were significantly elevated when the salt is present in the water. The dynamic saturated adsorption amount increased from 218.3mg/g in the deionized water to 309.5mg/g in a salt lake brine. The Tomas model was well applied to predict the breakthrough curves and determine the characteristics parameters of the adsorption column. PMID:24144367

Chang, Ganggang; Bao, Zongbi; Zhang, Zhiguo; Xing, Huabin; Su, Baogen; Yang, Yiwen; Ren, Qilong

2013-12-15

423

Electrochemical evaluation of antibacterial drugs as environment-friendly inhibitors for corrosion of carbon steel in HCl solution  

NASA Astrophysics Data System (ADS)

The effect of penicillin G, ampicillin and amoxicillin drugs on the corrosion behavior of carbon steel (ASTM 1015) in 1.0 mol L-1 hydrochloric acid solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques. The inhibition efficiency was found to increase with increasing inhibitor concentration. The effect of temperature on the rate of corrosion in the absence and presence of these drugs was also studied. Some thermodynamic parameters were computed from the effect of temperature on corrosion and inhibition processes. Adsorption of these inhibitors was found to obey Langmuir adsorption isotherm. There was a case of mixed mode of adsorption here but while penicillin was adsorbed mainly through chemisorption, two other drugs were adsorbed mainly through physisorption. Potentiodynamic polarization measurements indicated that the inhibitors were of mixed type. In addition, this paper suggests that the electrochemical noise (EN) technique under open circuit conditions as the truly noninvasive electrochemical method can be employed for the quantitative evaluation of corrosion inhibition. This was done by using the standard deviation of partial signal (SDPS) for calculation of the amount of noise charges at the particular interval of frequency, thereby obtaining the inhibition efficiency (IE) of an inhibitor. These IE values showed a reasonable agreement with those obtained from potentiodynamic polarization and EIS measurements.

Golestani, Gh.; Shahidi, M.; Ghazanfari, D.

2014-07-01

424

Laboratory determination of the carbon kinetic isotope effects (KIEs) for reactions of methyl halides with various nucleophiles in solution  

USGS Publications Warehouse

Large carbon kinetic isotope effects (KIEs) were measured for reactions of methyl bromide (MeBr), methyl chloride (MeCl), and methyl iodide (MeI) with various nucleophiles at 287 and 306 K in aqueous solutions. Rates of reaction of MeBr and MeI with H2O (neutral hydrolysis) or Cl- (halide substitution) were consistent with previous measurements. Hydrolysis rates increased with increasing temperature or pH (base hydrolysis). KIEs for hydrolysis were 51 ?? 6??? for MeBr and 38 ?? 8??? for MeI. Rates of halide substitution increased with increasing temperature and greater reactivity of the attacking nucleophile, with the fastest reaction being that of MeI with Br-. KIEs for halide substitution were independent of temperature but varied with the reactant methyl halide and the attacking nucleophile. KIEs were similar for MeBr substitution with Cl- and MeCl substitution with Br- (57 ?? 5 and 60 ?? 9??? respectively). The KIE for halide exchange of MeI was lower overall (33 ?? 8??? and was greater for substitution with Br- (46 ?? 6???) than with Cl- (29 ?? 6???). ?? Springer Science + Business Media, Inc. 2005.

Baesman, S.M.; Miller, L.G.

2005-01-01

425

The interaction of phosphate coatings on a carbon steel surface with a sodium nitrite and silicate solution  

NASA Astrophysics Data System (ADS)

Mono-cation PZn, bi-cation PZnCa, PZnNi and three-cation PZnNiMn crystalline phosphate coatings were modified with an inhibitor mixture: a sodium nitrite and sodium silicate solution with the aim to establish the reasons of protective ability enhancement of passive films on a carbon steel surface in an alkaline media. The SEM, EDS, XRD and XPS techniques were applied for the structural, phase and composition characterization of the phosphate coatings, voltammetric measurements were carried out to determine the passive layer protective ability, while EIS studies yielded information on the coatings porosity. Compact films of Si compounds were formed on the surface of the phosphate coatings during their modification procedure, which was accompanied by an increase in the protective ability of phosphate layer. A higher porosity and regularly shaped crystallites of the phosphate layer were favourable for accumulation of a greater amount of Si in the modified coatings. The protective ability of the modified coatings remains fairly pronounced, which testifies that the phosphate layer porosity is not the only factor influencing the corrosion behaviour of the coating. The difference in the nature of Si compounds comprising modified phosphate coatings leads to the differences in their protective ability.

Ramanauskas, R.; Gir?ien?, O.; Gudavi?i?t?, L.; Selskis, A.

2015-02-01

426

A complete carbon-nanotube-based on-chip cooling solution with very high heat dissipation capacity.  

PubMed

Heat dissipation is one of the factors limiting the continuous miniaturization of electronics. In the study presented in this paper, we designed an ultra-thin heat sink using carbon nanotubes (CNTs) as micro cooling fins attached directly onto a chip. A metal-enhanced CNT transfer technique was utilized to improve the interface between the CNTs and the chip surface by minimizing the thermal contact resistance and promoting the mechanical strength of the microfins. In order to optimize the geometrical design of the CNT microfin structure, multi-scale modeling was performed. A molecular dynamics simulation (MDS) was carried out to investigate the interaction between water and CNTs at the nanoscale and a finite element method (FEM) modeling was executed to analyze the fluid field and temperature distribution at the macroscale. Experimental results show that water is much more efficient than air as a cooling medium due to its three orders-of-magnitude higher heat capacity. For a hotspot with a high power density of 5000 W cm(-2), the CNT microfins can cool down its temperature by more than 40 °C. The large heat dissipation capacity could make this cooling solution meet the thermal management requirement of the hottest electronic systems up to date. PMID:22222357

Fu, Yifeng; Nabiollahi, Nabi; Wang, Teng; Wang, Shun; Hu, Zhili; Carlberg, Björn; Zhang, Yan; Wang, Xiaojing; Liu, Johan

2012-02-01

427

Electrochemically enhanced removal of polycyclic aromatic basic dyes from dilute aqueous solutions by activated carbon cloth electrodes.  

PubMed

Open-circuit (OC) adsorption and electrosorption behaviors of three polycyclic aromatic dyes from dilute aqueous solutions onto activated carbon cloth (ACC) were investigated. The selected dyes were crystal violet (BB-3), basic blue7 (BB-7), and basic blue11 (BB-11). OC adsorption and electrosorption processes were monitored by in situ UV-visible spectrophotometry. Electrosorption was carried out by polarization of an ACC electrode, galvanostatically. Considerable enhancements in removal capacity and duration of the dyes were achieved upon polarization of ACC. Kinetic data for OC adsorption and electrosorption were successfully treated according to pseudo-first-order law, and rate constants were determined. Adsorption isotherms were derived, and the data were treated according to Langmuir and Freundlich equations. Both the rate and extent of adsorption and electrosorption of dyes were found to increase in the order of BB-7 < BB-11 < BB-3. This order was discussed in terms of correlation between sizes of dye species and of ACC pores. Electrodesorption experiments were carried out to explore possibilities of regeneration of ACC. PMID:20704233

Bayram, Edip; Ayranci, Erol

2010-08-15

428

Geochemical and C, O, Sr, and U-series isotopic evidence for the meteoric origin of calcrete at Solitario Wash, Crater Flat, Nevada, USA  

USGS Publications Warehouse

Calcite-rich soils (calcrete) in alluvium and colluvium at Solitario Wash, Crater Flat, Nevada, USA, contain pedogenic calcite and opaline silica similar to soils present elsewhere in the semi-arid southwestern United States. Nevertheless, a ground-water discharge origin for the Solitario Wash soil deposits was proposed in a series of publications proposing elevation-dependent variations of carbon and oxygen isotopes in calcrete samples. Discharge of ground water in the past would raise the possibility of future flooding in the unsaturated zone at Yucca Mountain, Nevada, site of a proposed high-level nuclear waste repository. New geochemical and carbon, oxygen, strontium, and uranium-series isotopic data disprove the presence of systematic elevation-isotopic composition relations, which are the main justification given for a proposed ground-water discharge origin of the calcrete deposits at Solitario Wash. Values of ??13C (-4.1 to -7.8 per mil [???]), ??18O (23.8-17.2???), 87Sr/ 86Sr (0.71270-0.71146), and initial 234U/238U activity ratios of about 1.6 in the new calcrete samples are within ranges previously observed in pedogenic carbonate deposits at Yucca Mountain and are incompatible with a ground-water origin for the calcrete. Variations in carbon and oxygen isotopes in Solitario Wash calcrete likely are caused by pedogenic deposition from meteoric water under varying Quaternary climatic conditions over hundreds of thousands of years. ?? Springer-Verlag 2005.

Neymark, L.A.; Paces, J.B.; Marshall, B.D.; Peterman, Z.E.; Whelan, J.F.

2005-01-01

429

The potential impact of washing machines on laundry malodour generation.  

PubMed

A multidisciplinary approach has been adopted to investigate and identify the source of malodour in washing machines and the potential for cross-contamination of laundry. Four washing machines were olfactively graded, and the number of colony-forming units (CFUs) bacteria was determined in four specific locations. Then, samples of terry-towel and fleece were washed, without the use of detergent, in the machines, and the occurrence of malodour over a 52-h period was assessed. Analysis of the scrapings from the four locations in the two malodorous machines identified a plethora of volatile organic compounds (VOCs) by either olfactory detection or mass spectral identification post-gas chromatographic separation. In addition, microbiological analysis from the swabs from the four locations within all four washing machines was carried out. Quantitative analysis of VOCs from 66 microbiological isolates from either the washing machines or fabrics was carried out. In total, 10 VOCs were identified: dimethyl disulfide, 3-methyl-1-butanol, 2,4-dithiapentane, dimethyl trisulfide, 2-tridecanone, indole, 2-phenylethanol, isovaleric acid, isobutyric acid and 1-undecene. PMID:23350695

Stapleton, K; Hill, K; Day, K; Perry, J D; Dean, J R

2013-04-01

430

Hand Washing Among School Children in Bogotá, Colombia  

PubMed Central

Objectives. We assessed hand-washing behaviors and intentions among school children in Bogotá, Colombia, to help identify and overcome barriers to proper hygiene practices. Methods. Data on hand-washing behavior and intentions and individual and contextual factors were collected from 2042 sixth- through eighth-grade students in 25 schools in Bogotá via anonymous questionnaires. A member of the school administration or teaching staff completed a questionnaire about the school environment. Site inspections of bathroom facilities were conducted. Results. Only 33.6% of the sample reported always or very often washing hands with soap and clean water before eating and after using the toilet. About 7% of students reported regular access to soap and clean water at school. A high level of perceived control was the strongest predictor of positive hand-washing intentions (adjusted odds ratio [AOR] = 6.0; 95% confidence interval [CI] = 4.8, 7.5). Students with proper hand-washing behavior were less likely to report previous-month gastrointestinal symptoms (OR = 0.8; 95% CI = 0.6, 0.9) or previous-year school absenteeism (OR = 0.7; 95% CI = 0.6, 0.9). Conclusions. Scarcity of adequate facilities in most schools in Bogotá prevents children from adopting proper hygienic behavior and thwarts health promotion efforts. The current renovation program of public schools in Bogotá provides a unique opportunity to meet the challenges of providing a supportive environment for adoption of healthy behaviors. PMID:19008513

Lopez-Quintero, Catalina; Freeman, Paul

2009-01-01

431

Reductions of Salmonella enterica on chicken breast by thymol, acetic acid, sodium dodecyl sulfate or hydrogen peroxide combinations as compared to chlorine wash.  

PubMed

Poultry products are important vehicles for Salmonella transmission to humans and have been incriminated in several Salmonella outbreaks. Thymol (THY) from thyme oil has wide inhibitory effects against foodborne pathogens including Salmonella, and has shown great potential as a natural alternative to chlorine. In order to improve the cost-effectiveness of thymol-based washing solutions, formulas of THY with combination of organic acid or surfactant were developed and their efficacies to reduce Salmonella on chicken breast were investigated in the current study. Surface-inoculated chicken breasts were washed with the two thymol-based washing solutions: 0.2 mg/mL THY+5% (w/v) sodium dodecyl sulfate (SDS)+2 mg/mL acetic acid (AA) or 0.2 mg/mL THY+2 mg/mL AA for 2 min. Both solutions achieved around 2.2 log reductions of Salmonella on chicken breast and their efficacy was comparable to log reduction obtained by 200 ppm chlorine washing. Addition of SDS did not result in more log reduction of Salmonella on chicken meat samples. More than 3.3 log reduction in the used THY washing solutions was determined and it was similar to log reduction from the spent chlorine solution. None of these antimicrobial agents changed the pH and texture values of chicken breasts. Therefore, 0.2 mg/mL THY+2 mg/mL AA has great potential to be a natural alternative to chlorine-based washing solution for reducing Salmonella contamination on chicken breast meat. PMID:22030209

Lu, Y; Wu, C

2012-01-01

432

Monodisperse Calcium Carbonate Microtablets Forming at 701C in Prerefrigerated CaCl2GelatinUrea Solutions  

E-print Network

Monodisperse Calcium Carbonate Microtablets Forming at 701C in Prerefrigerated CaCl2­Gelatin Calcium carbonate particles with a unique tablet shape were produced by simply aging the prerefrigerated, and powder X-ray diffraction. Introduction Calcium carbonate (CaCO3) is an important ma- terial of marine

Tas, A. Cuneyt

433

Dye removal of activated carbons prepared from NaOH-pretreated rice husks by low-temperature solution-processed carbonization and H3PO4 activation.  

PubMed

A coupling of low-temperature sulfuric acid-assisted carbonization and H3PO4 activation was employed to convert NaOH-pretreated rice husks into activated carbons with extremely high surface area (2028 m(2) g(-1)) and integrated characteristics. The influences of the activation temperature and impregnation ratio on the surface area, pore volume of activated carbons were thoroughly investigated. The morphology and surface chemistry of activated carbons were characterized using N2 sorption, FTIR, XPS, SEM, TEM, etc. The adsorption capacity of resulting carbons obtained under optimum preparation conditions was systematically evaluated using methylene blue under various simulated conditions. The adsorption process can be well described by both Langmuir isotherm model and the pseudo-second order kinetics models; and the maximum monolayer capacity of methylene blue was ca. 578 mg g(-1). PMID:23892148

Chen, Yun; Zhai, Shang-Ru; Liu, Na; Song, Yu; An, Qing-Da; Song, Xiao-Wei

2013-09-01

434

A batch study on the bio-fixation of carbon dioxide in the absorbed solution from a chemical wet scrubber by hot spring and marine algae.  

PubMed

Carbon dioxide mass transfer is a key factor in cultivating micro-algae except for the light limitation of photosynthesis. It is a novel idea to enhance mass transfer with the cyclic procedure of absorbing CO(2) with a high performance alkaline abosorber such as a packed tower and regenerating the alkaline solution with algal photosynthesis. Hence, the algae with high affinity for alkaline condition must be purified. In this study, a hot spring alga (HSA) was purified from an alkaline hot spring (pH 9.3, 62 degrees C) in Taiwan and grows well over pH 11.5 and 50 degrees C. For performance of HSA, CO(2) removal efficiencies in the packed tower increase about 5-fold in a suitable growth condition compared to that without adding any potassium hydroxide. But ammonia solution was not a good choice for this system with regard to carbon dioxide removal efficiency because of its toxicity on HSA. In addition, HSA also exhibits a high growth rate under the controlled pHs from 7 to 11. Besides, a well mass balance of carbon and nitrogen made sure that less other byproducts formed in the procedure of carboxylation. For analysis of some metals in HSA, such as Mg, Mn, Fe, Zn, related to the photosynthesis increased by a rising cultivated pH and revealed that those metals might be accumulated under alkaline conditions but the growth rate was still limited by the ratio of bicarbonate (useful carbon source) and carbonate. Meanwhile, Nannochlopsis oculta (NAO) was also tested under different additional carbon sources. The results revealed that solutions of sodium/potassium carbonate are better carbon sources than ammonia carbonate/bicarbonate for the growth of NAO. However, pH 9.6 of growth limitation based on sodium was lower than one of HSA. The integrated system is, therefore, more feasible to treat CO(2) in the flue gases using the algae with higher alkaline affinity such as HSA in small volume bioreactors. PMID:16860839

Hsueh, H T; Chu, H; Yu, S T

2007-01-01

435

Increasing hand washing compliance with a simple visual cue.  

PubMed

We tested the efficacy of a simple, visual cue to increase hand washing with soap and water. Automated towel dispensers in 8 public bathrooms were set to present a towel either with or without activation by users. We set the 2 modes to operate alternately for 10 weeks. Wireless sensors were used to record entry into bathrooms. Towel and soap consumption rates were checked weekly. There were 97,351 hand-washing opportunities across all restrooms. Towel use was 22.6% higher (P=.05) and soap use was 13.3% higher (P=.003) when the dispenser presented the towel without user activation than when activation was required. Results showed that a visual cue can increase hand-washing compliance in public facilities. PMID:24228670

Ford, Eric W; Boyer, Brian T; Menachemi, Nir; Huerta, Timothy R

2014-10-01

436

Preparation of activated carbon from a renewable bio-plant of Euphorbia rigida by H 2SO 4 activation and its adsorption behavior in aqueous solutions  

NASA Astrophysics Data System (ADS)

The use of activated carbon obtained from Euphorbia rigida for the removal of a basic textile dye, which is methylene blue, from aqueous solutions at various contact times, pHs and temperatures was investigated. The plant material was chemically modified with H 2SO 4. The surface area of chemically modified activated carbon was 741.2 m 2 g -1. The surface characterization of both plant- and activated carbon was undertaken using FTIR spectroscopic technique. The adsorption process attains equilibrium within 60 min. The experimental data indicated that the adsorption isotherms are well described by the Langmuir equilibrium isotherm equation and the calculated adsorption capacity of activated carbon was 114.45 mg g -1 at 40° C. The adsorption kinetics of methylene blue obeys the pseudo-second-order kinetic model and also followed by the intraparticle diffusion model up to 60 min. The thermodynamic parameters such as ? G°, ? H° and ? S° were calculated to estimate the nature of adsorption. The activation energy of the system was calculated as 55.51 kJ mol -1. 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 textile dyes from textile wastewater processes.

Gerçel, Özgül; Özcan, Adnan; Özcan, A. Safa; Gerçel, H. Ferdi

2007-03-01

437

Chlorides behavior in raw fly ash washing experiments.  

PubMed

Chloride in fly ash from municipal solid waste incinerators (MSWIs) is one of the obstructive substances in recycling fly ash as building materials. As a result, we have to understand the behavior of chlorides in recycling process, such as washing. In this study, we used X-ray absorption near edge structure (XANES) and X-ray diffraction (XRD) to study the chloride behavior in washed residue of raw fly ash (RFA). We found that a combination of XRD and XANES, which is to use XRD to identify the situation of some compounds first and then process XANES data, was an effective way to explain the chlorides behavior in washing process. Approximately 15% of the chlorine in RFA was in the form of NaCl, 10% was in the form of KCl, 51% was CaCl(2), and the remainder was in the form of Friedel's salt. In washing experiments not only the mole percentage but also the amount of soluble chlorides including NaCl, KCl and CaCl(2) decreases quickly with the increase of liquid to solid (L/S) ratio or washing frequency. However, those of insoluble chlorides decrease slower. Moreover, Friedel's salt and its related compound (11CaO.7Al(2)O(3).CaCl(2)) were reliable standards for the insoluble chlorides in RFA, which are strongly related to CaCl(2). Washing of RFA promoted the release of insoluble chlorides, most of which were in the form of CaCl(2). PMID:20171782

Zhu, Fenfen; Takaoka, Masaki; Oshita, Kazuyuki; Kitajima, Yoshinori; Inada, Yasuhiro; Morisawa, Shinsuke; Tsuno, Hiroshi

2010-06-15

438

Water Conservation Tips When washing dishes by hand, don't let the water run while rinsing. Fill one sink with wash water and the  

E-print Network

Water Conservation Tips When washing dishes by hand, don't let the water run while rinsing. Fill one sink with wash water and the other with rinse water. Run your washing machine and dishwasher only instead and save gallons every time. For cold drinks keep a pitcher of water in the refrigerator instead

439

A semi-analytical solution to accelerate spin-up of a coupled carbon and nitrogen land model to steady state  

NASA Astrophysics Data System (ADS)

The spin-up of land models to steady state of coupled carbon-nitrogen processes is computationally so costly that it becomes a bottleneck issue for global analysis. In this study, we introduced a semi-analytical solution (SAS) for the spin-up issue. SAS is fundamentally based on the analytic solution to a set of equations that describe carbon transfers within ecosystems over time. SAS is implemented by three steps: (1) having an initial spin-up with prior pool-size values until net primary productivity (NPP) reaches stabilization, (2) calculating quasi-steady-state pool sizes by letting fluxes of the equations equal zero, and (3) having a final spin-up to meet the criterion of steady state. Step 2 is enabled by averaged time-varying variables over one period of repeated driving forcings. SAS was applied to both site-level and global scale spin-up of the Australian Community Atmosphere Biosphere Land Exchange (CABLE) model. For the carbon-cycle-only simulations, SAS saved 95.7% and 92.4% of computational time for site-level and global spin-up, respectively, in comparison with the traditional method (a long-term iterative simulation to achieve the steady states of variables). For the carbon-nitrogen coupled simulations, SAS reduced computational cost by 84.5% and 86.6% for site-level and global spin-up, respectively. The estimated steady-state pool sizes represent the ecosystem carbon storage capacity, which was 12.1 kg C m-2 with the coupled carbon-nitrogen global model, 14.6% lower than that with the carbon-only model. The nitrogen down-regulation in modeled carbon storage is partly due to the 4.6% decrease in carbon influx (i.e., net primary productivity) and partly due to the 10.5% reduction in residence times. This steady-state analysis accelerated by the SAS method can facilitate comparative studies of structural differences in determining the ecosystem carbon storage capacity among biogeochemical models. Overall, the computational efficiency of SAS potentially permits many global analyses that are impossible with the traditional spin-up methods, such as ensemble analysis of land models against parameter variations.

Xia, J. Y.; Luo, Y. Q.; Wang, Y.-P.; Weng, E. S.; Hararuk, O.

2012-10-01

440

A semi-analytical solution to accelerate spin-up of a coupled carbon and nitrogen land model to steady state  

NASA Astrophysics Data System (ADS)

The spin-up of land models to steady state of coupled carbon-nitrogen processes is computationally so costly that it becomes a~bottleneck issue for global analysis. In this study, we introduced a semi-analytical solution (SAS) for the spin-up issue. SAS is fundamentally based on the analytic solution to a set of equations that describe carbon transfers within ecosystems over time. SAS is implemented by three steps: (1) having an initial spin-up with prior pool-size values until net primary productivity (NPP) reaches steady state, (2) calculating quasi steady-state pool sizes by letting fluxes of the equations equal zero, and (3) having a final spin-up to meet the criterion of steady state. Step 2 is enabled by averaged time-varying variables over one period of repeated driving forcings. SAS was applied to both site-level and global scale spin-up of the Australian Community Atmosphere Biosphere Land Exchange (CABLE) model. For the carbon-cycle-only simulations, SAS saved 95.7% and 92.4% of computational time for site-level and global spin-up, respectively, in comparison with the traditional method. For the carbon-nitrogen-coupled simulations, SAS reduced computational cost by 84.5% and 86.6% for site-level and global spin-up, respectively. The estimated steady-state pool sizes represent the ecosystem carbon storage capacity, which was 12.1 kg C m-2 with the coupled carbon-nitrogen global model, 14.6% lower than that with the carbon-only model. The nitrogen down-regulation in modeled carbon storage is partly due to the 4.6% decrease in carbon influx (i.e., net primary productivity) and partly due to the 10.5% reduction in residence times. This steady-state analysis accelerated by the SAS method can facilitate comparative studies of structural differences in determining the ecosystem carbon storage capacity among biogeochemical models. Overall, the computational efficiency of SAS potentially permits many global analyses that are impossible with the traditional spin-up methods, such as ensemble analysis of land models against parameter variations.

Xia, J.; Luo, Y.; Wang, Y.-P.; Weng, E.; Hararuk, O.

2012-04-01

441

100 Area soil washing bench-scale test procedures  

SciTech Connect

This document describes methodologies and procedures for conducting soil washing treatability tests in accordance with the 100 Area Soil Washing Treatability Test Plan (DOE-RL 1992, Draft A). The objective of this treatability study is to evaluate the use of physical separation systems and chemical extraction methods as a means of separating chemically and radioactively contaminated soil fractions from uncontaminated soil fractions. These data will be primarily used for determining feasibility of the individual unit operations and defining the requirements for a system, or systems, for pilot-scale testing.

Freeman, H.D.; Gerber, M.A.; Mattigod, S.V.; Serne, R.J.

1993-03-01

442

The adsorption of hetero- and alicyclic thiophene derivatives from water-acetonitrile solutions on the surface of porous graphitic carbon under high-performance liquid chromatography conditions  

NASA Astrophysics Data System (ADS)

The adsorption of hetero- and alicyclic thiophene derivatives synthesized for the first time from water-acetonitrile solutions with various compositions on the surface of porous graphitic carbon was studied by the high-performance liquid chromatography method. The retention factor and Henry adsorption constant values and equilibrium constants of quasi-chemical reactions of the adsorption and solvation of the heterocyclic compounds studied were calculated using the Lanin-Nikitin equation. The influence of the structure of hetero- and alicyclic thiophene derivative molecules on their adsorption on the surface of porous graphitic carbon and solvation in water-acetonitrile solutions was discussed. The Lanin-Nikitin model was found to be more informative in the interpretation of the adsorption-chromatographic experiment data compared with the Snyder-Soczewinski and Scott-Kucera models.

Saifutdinov, B. R.; Emel'yanova, N. S.; Kurbatova, S. V.; Pimerzin, A. A.

2012-07-01

443

Preparation of low cost activated carbon from Myrtus communis and pomegranate and their efficient application for removal of Congo red from aqueous solution  

Microsoft Academic Search

In this research, the potential applicability of activated carbon prepared from Myrtus communis (AC–MC) and pomegranate (AC–PG) as useful adsorbents for the removal of Congo red (CR) from aqueous solutions in batch method was investigated. The effects of pH, contact time, agitation time and amount of adsorbents on removal percentage of Congo red on both adsorbents were examined. Increase in

Mehrorang Ghaedi; Hossein Tavallali; Mahdi Sharifi; Syamak Nasiri Kokhdan; Alireza Asghari

444

A pilot plant scale evaluation of a new process aid for enhancing chlorine efficacy against pathogen survival and cross-contamination during produce wash.  

PubMed

Developing food safety intervention technology that can be readily adopted by the industry often requires test conditions that match as closely as possible to those of commercial food processing operations; yet biosafety risks inherent in pathogen studies constrain most experiments to laboratory settings. In this study, we report the first semi-commercial pilot-scale evaluation of a new process aid, T128, for its impact on enhancing the antimicrobial efficacy of chlorinated wash water against pathogen survival and cross-contamination. A non-pathogenic, BSL-1, strain of Escherichia coli O157:H7 was inoculated onto freshly harvested baby spinach leaves and washed with large amounts of freshly cut un-inoculated iceberg lettuce shreds in wash water with free chlorine periodically replenished, in the presence or absence of T128. Changes in water quality and pathogen survival and cross-contamination were monitored at every 2 min intervals for up to 36 min for each treatment during the wash operation. Results indicated that the use of T128 did not significantly (P>0.05) influence the rate of wash water deterioration, nor the pathogen populations remaining on the inoculated spinach leaves. However, in the absence of T128 (control), survival of E. coli O157:H7 in wash water and cross-contamination of un-inoculated lettuce frequently occurred when free chlorine in solution dropped below 1mg/l during the wash process. In contrast, the use of T128 significantly reduced the occurrence of E. coli O157:H7 surviving in wash water and of cross-contamination to un-inoculated shredded iceberg lettuce under the same operational conditions, suggesting that the application of T128 in a chlorine-based fresh produce sanitization system could increase the safety margin of process control on fresh-cut operations. PMID:22857846

Luo, Yaguang; Nou, Xiangwu; Millner, Patricia; Zhou, Bin; Shen, Cangliang; Yang, Yang; Wu, Yunpeng; Wang, Qin; Feng, Hao; Shelton, Dan

2012-08-17

445

Adsorption of dyes from aqueous solution onto activated carbons prepared from date pits: The effect of adsorbents pore size distribution  

Microsoft Academic Search

Several active carbons were prepared starting from Algerian date pits by chemical activation with the ZnCl2, by physical activation with the CO2, and by a method combined in the presence of ZnCl2\\/CO2. The active carbons obtained were followed by the evaluation of the yield and the physisorption of nitrogen at 77 K. Activated carbon particles were analyzed by scanning electron

Naima Bouchemal; Fatima Addoun

2009-01-01

446

PS/PMMA Blends in the Presence of Cyclohexane: Selective Solvent Washing or Equilibrium Adsorption?  

NASA Astrophysics Data System (ADS)

Cyclohexane has been frequently used as a selective solvent to remove PS layers or domains from polystyrene:poly(methyl methacrylate) (PS:PMMA) blends and for reorganization or self-assembly of polymer brushes and block copolymers. We have found that cyclohexane is not efficient at PS removal, observing significant residual PS at PMMA surfaces. These results were compared to PMMA surfaces after PS was allowed to adsorb to the surface from a dilute theta solution in cyclohexane. Using near edge X-ray absorption fine structure spectroscopy and inverse gas chromatography, coupled with theoretical calculations using self-consistent mean-field theory, we have demonstrated that selectively washing a polymer from a polymer blend is nearly identical to adsorption of a polymer to a `soft' surface from a dilute solution. Improved knowledge about the effects of selective solvents will improve experimental analysis of washed systems as well as the manipulation of block copolymer and polymer brush reorganization or self-assembly.

Ade, Harald; Harton, S. E.; Luning, J.; Betz, H.

2007-03-01

447

Signalling-Dependent Adverse Health Effects of Carbon Nanoparticles Are Prevented by the Compatible Solute Mannosylglycerate (Firoin) In Vitro and In Vivo  

PubMed Central

The inhalation of combustion-derived nanoparticles leads to adverse health effects in the airways. In this context the induction of membrane-coupled signalling is considered as causative for changes in tissue homeostasis and pro-inflammatory reactions. The identification of these molecular cell reactions allowed to seek for strategies which interfere with these adverse effects. In the current study, we investigated the structurally different compatible solutes mannosylglycerate (firoin) from thermophilic bacteria and ectoine from halophilic bacteria for their capability to reduce signalling pathways triggered by carbon nanoparticles in target cells in the lung. The pre-treatment of lung epithelial cells with both substances decreased the particle-specific activation of mitogen-activated protein kinases and also the endpoints proliferation and apoptosis. Firoin applied into the lungs of animals, like ectoine, led to a significant reduction of the neutrophilic lung inflammation induced by particle exposure. The pro-inflammatory effect of carbon nanoparticles on human neutrophil granulocytes ex vivo was significantly reduced by both substances via the reduction of the anti-apoptotic membrane-dependent signalling. The data of this study together with earlier studies demonstrate that two structurally non-related compatible solutes are able to prevent pathogenic reactions of the airways to carbon nanoparticles by interfering with signalling events. The findings highlight the preventive or therapeutic potential of compatible solutes for adverse health effects caused by particle exposure of the airways. PMID:25415441

Kroker, Matthias; Hornstein, Tamara; Ale-Agha, Niloofar; Stöckmann, Daniel; Bilstein, Andreas; Albrecht, Catrin; Paunel-Görgülü, Adnana; Suschek, Christoph V.; Krutmann, Jean; Unfried, Klaus

2014-01-01

448

Conservation of water for washing beef heads at harvest  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this research was to develop methods to conserve water necessary to cleanse beef heads prior to USDA–FSIS inspection. This was to be accomplished by establishing a baseline for the minimum amount of water necessary to adequately wash a head and application of image analysis to provi...