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1

Solvent wash solution  

DOEpatents

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

Neace, James C. (Blackville, SC)

1986-01-01

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

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

5

Washing of soils spiked with various pollutants by surfactant solutions  

SciTech Connect

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

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

1995-12-31

6

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

NASA Astrophysics Data System (ADS)

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

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

1998-03-01

7

Changes in the Bacterial Flora of Skin of Processed Broiler Chickens Washed in Solutions of Salicylic Acid  

Microsoft Academic Search

Changes in the number of bacteria recovered from the skin of processed broilers after each of five consecutive washings in salicylic acid (SA) solutions was examined. Skin samples from commercially processed broiler carcasses were divided into 3 groups and washed in distilled water (control), 10% SA, or 20% SA by agitating skin in wash solutions in a Stomacher laboratory blender.

A. Hinton Jr.; J. A. Cason

2007-01-01

8

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

PubMed

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

Voglar, David; Lestan, Domen

2012-04-15

9

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

NASA Technical Reports Server (NTRS)

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

Saunders, Chad; Evans, Kurt; Sagers, Neil

1999-01-01

10

Evaluation of the antiviral activity of a green tea solution as a hand-wash disinfectant.  

PubMed

Based on the broad-spectrum antiviral effect of green tea catechins, we established an experimental skin contact model for influenza virus transmission and evaluated the use of a green tea solution as a first-hand disinfectant. The infectivity of the virus on the skin cell layer became obsolete when washed with the green tea solution. The skin contact model could be applied to develop non-pharmaceutical intervention measures for reducing human transmission of the influenza virus. PMID:22451404

Shin, Woo-Jin; Kim, Young-Kyung; Lee, Kwang-Hee; Seong, Baik-Lin

2012-01-01

11

Fresh-cut product sanitation and wash water disinfection: problems and solutions.  

PubMed

It is well known that fresh-cut processors usually rely on wash water sanitizers to reduce microbial counts in order to maintain quality and extend shelf-life of the end product. Water is a useful tool for reducing potential contamination but it can also transfer pathogenic microorganisms. Washing with sanitizers is important in fresh-cut produce hygiene, particularly removing soil and debris, but especially in water disinfection to avoid cross-contamination between clean and contaminated product. Most of the sanitizing solutions induce higher microbial reduction after washing when compared to water washing, but after storage, epiphytic microorganisms grow rapidly, reaching similar levels. In fact, despite the general idea that sanitizers are used to reduce the microbial population on the produce, their main effect is maintaining the microbial quality of the water. The use of potable water instead of water containing chemical disinfection agents for washing fresh-cut vegetables is being advocated in some European countries. However, the problems of using an inadequate sanitizer or even none are considered in this manuscript. The need for a standardized approach to evaluate and compare the efficiency of sanitizing agents is also presented. Most new alternative techniques accentuate the problems with chlorine suggesting that the industry should move away from this traditional disinfection agent. However, the use of chlorine based sanitizers are presented as belonging to the most effective and efficient sanitizers when adequate doses are used. In this review improvements in water disinfection and sanitation strategies, including a shower pre-washing step and a final rinse of the produce, are suggested. PMID:19539390

Gil, Maria I; Selma, Maria V; López-Gálvez, Francisco; Allende, Ana

2009-08-31

12

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

PubMed

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

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

2008-11-01

13

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

14

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

15

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 ...

16

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

PubMed

The Asia Oceania Human Proteome Organisation (AOHUPO) has embarked on a Membrane Proteomics Initiative with goals of systematic comparison of strategies for analysis of membrane proteomes and discovery of membrane proteins. This multilaboratory project is based on the analysis of a subcellular fraction from mouse liver that contains endoplasmic reticulum and other organelles. In this study, we present the strategy used for the preparation and initial characterization of the membrane sample, including validation that the carbonate-washing step enriches for integral and lipid-anchored membrane proteins. Analysis of 17 independent data sets from five types of proteomic workflows is in progress. PMID:20486120

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

2010-11-01

17

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...

18

Solution-processed soldering of carbon nanotubes for flexible electronics.  

PubMed

We report a simple lithography-free, solution-based method of soldering of carbon nanotubes with Ohmic contacts, by taking specific examples of multi-walled carbon nanotubes (MWNTs). This is achieved by self-assembling a monolayer of soldering precursor, Pd(2+) anchored to 1,10 decanedithiol, onto which MWNTs could be aligned across the gap electrodes via solvent evaporation. The nanosoldering was realized by thermal/electrical activation or by both in sequence. Electrical activation and the following step of washing ensure selective retention of MWNTs spanning across the gap electrodes. The soldered joints were robust enough to sustain strain caused during the bending of flexible substrates as well as during ultrasonication. The estimated temperature generated at the MWNT-Au interface using an electro-thermal model is ?150?°C, suggesting Joule heating as the primary mechanism of electrical activation. Further, the specific contact resistance is estimated from the transmission line model. PMID:23358531

Rao, K D M; Radha, B; Smith, K C; Fisher, T S; Kulkarni, G U

2013-02-22

19

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

PubMed

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

Qiu, Weihua; Zhang, Wenyan; Chen, Hongzhang

2014-03-01

20

Enhanced soil washing of phenanthrene by mixed solutions of TX100 and SDBS.  

PubMed

Increased desorption of hydrophobic organic compounds (HOCs) from soils and sediments is a key to the remediation of contaminated soils and groundwater. In this study, phenanthrene desorption from a contaminated soil by mixed solutions of a nonionic surfactant(octylphenol polyethoxylate, TX100) and an anionic surfactant (sodium dodecylbenzenesulfonate, SDBS) was investigated. Phenanthrene desorption depended on not only aqueous surfactant concentrations and phenanthrene solubility enhancement but also the soil-sorbed surfactant amount and the corresponding sorption capacity of sorbed surfactants. The added surfactant critical desorption concentrations (CDCs) for phenanthrene from soil depended on both sorbed concentrations of surfactants and their critical micelle concentrations (CMCs). Phenanthrene desorption by mixed solutions was more efficient than individual surfactants due to the low sorption loss of mixed surfactants to soil. Among the tested surfactant systems, mixed TX100 and SDBS with a 1:9 mass ratio exhibited the highest phenanthrene desorption. Mixed micelle formation, showing negative deviation of CMCs from the ones predicted by the ideal mixing theory, was primarily responsible for the significant reduction of soil-sorbed amounts of TX100 and SDBS in their mixed systems. Therefore, mixed anionic-nonionic surfactants had great potential in the area of enhanced soil and groundwater remediation. PMID:16856746

Yang, Kun; Zhu, Lizhong; Xing, Baoshan

2006-07-01

21

PROCESSING, PRODUCTS, AND FOOD SAFETY Recovery of Bacteria from Broiler Carcasses after Spray Washing with Acidified Electrolyzed Water or Sodium Hypochlorite Solutions  

Microsoft Academic Search

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

J. Northcutt; D. Smith; K. D. Ingram; A. Hinton Jr.; M. Musgrove

22

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.

23

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

24

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

25

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

Microsoft Academic Search

Duck meat is less utilized than other meats in processed products because of limitations of its functional properties, including\\u000a lower water holding capacity, emulsion stability, and higher cooking loss compared with chicken meat. These limitations could\\u000a be improved using surimi technology, which consists of washing and concentrating myofibrillar protein. In this study, surimi-like\\u000a materials were made from duck meat using

Kurnia Ramadhan; Nurul Huda; Ruzita Ahmad

26

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

PubMed Central

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

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

2011-01-01

27

Biodiesel production by two-stage transesterification with ethanol by washing with neutral water and water saturated with carbon dioxide.  

PubMed

Industrial production of ethyl esters is impeded by difficulties in purifying the product due to high amounts of soap formed during transesterification. A simple biodiesel wash process was developed that allows successful purification of samples containing high amounts of soap. The key step was a first washing with neutral water, which removed the soaps without increasing the acidity or affecting the process yield. Afterward, the biodiesel was washed with water saturated with CO(2), a mild acid that neutralized the remaining soaps and extracted impurities. The acidity, free-glycerine, methanol and soaps concentrations were reduced to very low levels with high efficiency, and using non-corrosive acids. Independently of the initial acidity, it was possible to obtain biodiesel within EN14214 specifications. The process included the recovery of soaps by hydrolysis and esterification, making it possible to obtain the theoretical maximum amount of biodiesel. PMID:22721682

Mendow, G; Veizaga, N S; Sánchez, B S; Querini, C A

2012-08-01

28

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

PubMed Central

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

29

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

E-print Network

BEHAVIOR OF CARBON ISOTOPES DURING THE HYPERFILTRATION OF CALCIUM CARBONATE SOLUTIONS THROUGH CALCIUM BENTONITES A Thesis DAVID WILLIAM HINZ Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1987 Major Subject: Geology BEHAVIOR OF CARBON ISOTOPES DURING THE HYPERFILTRATION OF CALCIUM CARBONATE SOLUTIONS THROUGH CALCIUM BENTONITES A Thesis by DAVID WILLIAM HINZ Approved as to style and content by...

Hinz, David William

2012-06-07

30

Adsorption of uranium from aqueous solutions using activated carbon  

SciTech Connect

The adsorption of uranium from aqueous solution has been investigated using conventional commercially available activated carbons. It was found that treatment with hot nitric acid oxidized the surface of activated carbon and significantly increased the adsorption capacity for uranium in near-neutral and slightly acidic nitrate solutions. Equilibrium data were fitted to a simplified Freundlich isotherm for the purpose of comparison of oxidized and as-received samples. The decontamination of aqueous solutions was investigated in small column experiments. An ion-exchange mechanism of uranium sorption from aqueous solution is discussed. 43 refs., 11 figs., 1 tab.

Abbasi, W.A. (Pakistan Atomic Energy Commission, Islamabad (Pakistan)); Streat, M. (Loughborough Univ. of Technology, Leicestershire (United Kingdom))

1994-06-01

31

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

Microsoft Academic Search

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

F. J. Carrión Fité

1992-01-01

32

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

33

Electroreduction of carbon dioxide in aqueous solutions at metal electrodes  

SciTech Connect

The quantities of carbon stored in the form of atmospheric carbon dioxide, CO{sub 2} in the hydrosphere and carbonates in the terrestrial environment substantially exceed those of fossil fuels. In spite of this the industrial use of carbon dioxide as a source of chemical carbon is presently limited to preparation of urea and certain carboxylic acids as well as organic carbonates and polycarbonates. However, the situation is expected to change in the future, if effective catalytic systems allowing to activate carbon dioxide will become available. In this connection, the electrochemical reduction of CO{sub 2}, requiring only an additional input of water and electrical energy, appears as an attractive possibility. For more than 100 years formic acid and formates of alkali metals were considered as the only significant products of the electroreduction of carbon dioxide in aqueous solutions. The highest current efficiencies, exceeding 90 %, were obtained either with mercury or with amalgam electrodes. The only comprehensive study regarding kinetics of CO{sub 2} reduction in aqueous solution has been performed by Eyring et al. using a mercury cathode. This paper describes electrolysis studies.

Augustynski, J.; Jermann, B.; Kedzierzawski, P. [Univ. of Geneva (Switzerland)

1996-12-31

34

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

35

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...

36

The resistance of recent marine carbonate sediments to solution  

E-print Network

to Samples in the a Mater Page 34 11 +e Dissolved Amounts of Mg w Percent NgC03 in Sediment Pairs of Synthetic Sea Wa ith Respect Samples in ter 't 0 the Ion 35 12 Typical Variations in pH for Various Grain Size Carbonate Sediments 37 LIST.... The carbonate ion concentration of the ground carbonate sediments in NgC1 may be beginning to level off according to Figur. e 5, and the ~+ [Ca j [CO ] ion product from Figure 9 has about reached a constant value, ++ The absence of Mg in solution can...

Jansen, John F

2012-06-07

37

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

38

Solution Processed Carbon Nanotube \\/PMMA Nano Composite Infrared Photodetectors  

Microsoft Academic Search

Solution processable nanostructured materials are of great interest for electronic and optical devices because of their enhance functionality, easy processibility, flexibility, and low cost of fabrication. We tested multi walled carbon nanotube networks dispersed in poly (methyl methacrylate) (PMMA) matrix for use as the infrared (IR) photodetectors at room temperature in ambient condition. Our study reveals both negative and positive

Yi Liu; Liwei Liu; Paul Stokes; Qun Huo; Saiful I. Khondaker

2008-01-01

39

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

40

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

41

Electrosorption of inorganic salts from aqueous solution using carbon aerogels.  

PubMed

Capacitive deionization (CDI) with carbon aerogels has been shown to remove various inorganic species from aqueous solutions, though no studies have shown the electrosorption behavior of multisolute systems in which ions compete for limited surface area. Several experiments were conducted to determine the ion removal capacity and selectivity of carbon aerogel electrodes, using both laboratory and natural waters. Although carbon aerogel electrodes have been treated as electrical double-layer capacitors, this study showed that ion sorption followed a Langmuir isotherm, indicating monolayer adsorption. The sorption capacity of carbon aerogel electrodes was approximately 1.0-2.0 x 10(-4) equiv/g aerogel, with ion selectivity being based on ionic hydrated radius. Monovalent ions (e.g., sodium) with smaller hydrated radii were preferentially removed from solution over multivalent ions (e.g., calcium) on a percent or molar basis. Because of the relatively small average pore size (4-9 nm) of the carbon aerogel material, only 14-42 m2/g aerogel surface area was available for ion sorption. Natural organic matter may foul the aerogel surface and limit CDI effectiveness in treating natural waters. PMID:12144279

Gabelich, Christopher J; Tran, Tri D; Suffet, I H Mel

2002-07-01

42

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

43

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. ...

44

Sorption of cobalt on activated carbons from aqueous solutions  

SciTech Connect

The efficiencies of 15 commercially available activated carbons were tested for the separation of trace cobalt ({sup 60}Co) in buffer solutions at pH 5.0, 6.7, and 9.1. On the basis of the results four carbon products, Diahope-006, Eurocarb TN5, Hydraffin DG47, and Norit ROW Supra, were selected for further study. These carbons represented varying (low, medium and high) cobalt removal efficiencies and were prepared of three typical raw materials: peat, coconut shell, or coal. Study was made of the effects on sorption efficiencies of factors of interest in metal/radionuclide-bearing waste effluents. These factors were pH, sodium ions, borate, and citrate.

Paajanen, A.; Lehto, J.; Santapakka, T.; Morneau, J.P. [Univ. of Helsinki (Finland)

1997-01-01

45

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

46

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

47

Estimated steady-state compositions of supernatant liquid during sludge washing  

SciTech Connect

Steady-state hydroxide, pH, carbonate and bicarbonate levels have been estimated for supernatant liquids during sludge washing and storage. These compositions were needed in order to prepare synthetic solutions for determining inhibitor requirements. The steady-state pH was plotted versus the nitrate concentration and fitted to a logarithmic expression of the form, pH = 10.23 [times] [NO[sub 3][minus

Hobbs, D.T.

1991-11-12

48

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

49

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

50

carbonate solid solution at high pressures up to 55 GPa  

NASA Astrophysics Data System (ADS)

Magnesite, siderite and ferromagnesites Mg1- x Fe x CO3 ( x = 0.05, 0.09, 0.2, 0.4) were characterized using in situ Raman spectroscopy at high pressures up to 55 GPa. For the Mg-Fe-carbonates, the Raman peak positions of six modes (T, L, ?4, ?1, ?3 and 2?2) in the dependence of iron content in the carbonates at ambient conditions are presented. High-pressure Raman spectroscopy shows that siderite undergoes a spin transition at ~40 GPa. The examination of the solid solutions with compositions Mg0.6Fe0.4CO3, Mg0.8Fe0.2CO3, Mg0.91Fe0.09CO3 and Mg0.95Fe0.05CO3 indicates that with increase in the amount of the Fe spin transition pressure increases up to ~45 GPa.

Spivak, Anna; Solopova, Natalia; Cerantola, Valerio; Bykova, Elena; Zakharchenko, Egor; Dubrovinsky, Leonid; Litvin, Yuriy

2014-09-01

51

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

52

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

53

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

54

Electroreduction of carbon dioxide in aqueous solutions at metal electrodes  

Microsoft Academic Search

The quantities of carbon stored in the form of atmospheric carbon dioxide, COâ in the hydrosphere and carbonates in the terrestrial environment substantially exceed those of fossil fuels. In spite of this the industrial use of carbon dioxide as a source of chemical carbon is presently limited to preparation of urea and certain carboxylic acids as well as organic carbonates

J. Augustynski; B. Jermann; P. Kedzierzawski

1996-01-01

55

Aqueous chemical wash compositions  

SciTech Connect

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

Bannister, C.E.

1987-07-21

56

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

57

Enzymes for low temperature washing  

Microsoft Academic Search

The increasing use of synthetic fibers which cannot tolerate temperatures above 50–60 C has changed the washing habits during\\u000a the past 5–10 years toward the use of lower washing temperatures. Furthermore, the energy crisis has focused interest on washing\\u000a at ambient temperatures for the purpose of saving energy. In order to compensate for the lower washing efficiency at decreased\\u000a temperatures,

M. H. Nielsen; S. J. Jepsen; H. Outtrup

1981-01-01

58

Carbon footprint optimization: game theoretic problems and solutions  

Microsoft Academic Search

We discuss four problems that we have identified under the umbrella of carbon economics problems: carbon credit allocation (CCA), carbon credit buying (CCB), carbon credit selling (CCS), and carbon credit exchange (CCE). Because of the strategic nature of the players involved in these problems, game theory and mechanism design provides a natural way of formulating and solving these problems. We

Deepak Bagchi; Shantanu Biswas; Y. Narahari; P. Suresh; L. Udaya Lakshmi; N. Viswanadham; S. V. Subrahmanya

59

Estimated steady-state compositions of supernatant liquid during sludge washing  

SciTech Connect

Steady-state hydroxide, pH, carbonate and bicarbonate levels have been estimated for supernatant liquids during sludge washing and storage. These compositions were needed in order to prepare synthetic solutions for determining inhibitor requirements. The steady-state pH was plotted versus the nitrate concentration and fitted to a logarithmic expression of the form, pH = 10.23 {times} [NO{sub 3}{minus}]{sup 0.0178} where [NO{sub 3}{minus}] is the concentration of nitrate in moles/liter. Similar expressions were also developed for calculating the concentrations of carbonate and bicarbonate as a function of the nitrate concentration.

Hobbs, D.T.

1991-11-12

60

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

61

Polyelectrolyte and carbon nanotube multilayers made from ionic liquid solutions.  

PubMed

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

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

2010-10-01

62

Aluminum removal from washed sludge  

SciTech Connect

Purpose of this project is to reduce the volume of storage tank sludge to be treated by removing the Al and other nonradioactive components. In initial sludge surrogate studies, Al, Cr, and Zn showed the highest solubility in NaOH solutions; Ce and Zr were the least soluble of the elements tested. Removal of Fe and Bi approached 2%, the rest of the elements studied showed <1% removal. Amount of Al removed increased as the NaOH conc. increased from 0.1 to 6 M. Sequential washing of the sludge surrogate with 3 M NaOH removed 84% of the Al, 39% of the Cr, and 65% of the Zn. Surrogate sludges containing U and Th were also studied.

Egan, B.Z.; Collins, J.L. [Oak Ridge National Lab., TN (United States); Ensor, D.D. [Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Chemistry

1995-12-31

63

Calcium carbonate precipitation along solution-solution interfaces in porous media  

NASA Astrophysics Data System (ADS)

Biogeochemical processes, such as mineral precipitation, microbial growth, or filtration of biological or mineral colloids, can lead to localized solid deposition and changes in flow and permeability in porous media. The coupling between these processes and flow depends on instantaneous flow paths, dispersive or diffusional mixing, localized flow velocities and the kinetics of the biogeochemical reactions themselves. We have conducted experiments to help predict the outcome of this coupling and how solids are, or could intentionally be, spatially distributed. Initial experiments have used calcium carbonate precipitation in packed sand as a model system that has conceptual parallels to other biological and chemical processes that generate mass in porous media. (A second experiment involves precipitate promotion via in situ urea hydrolysis.) Parallel flowstreams of carbonate and calcium produce a mixing zone at the solution-solution interface by diffusion and dispersion. The flowstreams have been created in both an annular geometry in a column, and in a 2-D flow cell. X-ray tomography and color contrast methods are used to visualize the deposition process at the solution-solution interface, and tracer analysis is used to analyze the systems for the evolution of heterogeneities and changes in permeability. For the 2-D flow cell, continuum-scale modeling (using STORM, STOMP and Hydrogeochem codes) is used to simulate the reactant concentration profiles along the interfacial mixing zone behavior prior to precipitation, a saturation index profile, the changes in permeability that are induced as a consequence of precipitate deposition along the interface, and the subsequent changes in how reactive solutes mix along the interface. The modeling goal is to link the continuum-scale simulations to more detailed pore-scale simulations that are capable of representing the coupling between solute concentrations, nucleation kinetics, precipitate growth kinetics, how precipitates fill pore spaces and how flow paths changes with time. Smoothed Particle Hydrodynamics are being used for simulations at the pore scale. The intention is to experimentally observe, and ultimately to control, how precipitates can be distributed in porous matrices.

Redden, G. D.; Fang, Y.; Scheibe, T.; Tartakovsky, A.; Fox, D. T.; White, T. A.; Fujita, Y.; Delwiche, M.

2005-12-01

64

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

65

Polyelectrolyte and carbon nanotube multilayers made from ionic liquid solutions  

NASA Astrophysics Data System (ADS)

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

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

2010-10-01

66

REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION BY BIOADSORPTION ONTO Ricinus communis EPICARP ACTIVATED CARBON  

Microsoft Academic Search

Carbon prepared from the epicarp of Ricinus communis was used to remove a textile dye (methylene blue (MB)) from an aqueous solution by adsorption technique under varying conditions of agitation time, dye concentration, adsorbent dose and pH. Adsorption depended on solution pH, dye concentration, carbon concen- tration and contact time. Adsorption followed both Langmuir and Freundlich isotherm models. The adsorption

T. Santhi; S. Manonmani

2009-01-01

67

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

68

Laboratory testing in-tank sludge washing, summary letter report  

SciTech Connect

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

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

1994-09-01

69

On the black carbon problem and its solutions  

NASA Astrophysics Data System (ADS)

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

Jacobson, M. Z.

2010-12-01

70

Method of solubilizing shortened single-walled carbon nanotubes in organic solutions  

US Patent & Trademark Office Database

Naked single-walled nanotube carbon metals and semiconductors were dissolved in organic solutions by derivatization with SOCl.sub.2 and octadecylamine charge. Both ionic (charge transfer) and covalent solution phase chemistry with concomitant modulation of the single-walled carbon nanotubes (SWNT) band structure were demonstrated. Solution phase near-IR spectroscopy was used to study the effects of chemical modifications on the band gaps of the SWNTs. Reaction of solubilized SWNTs with dichlorocarbene led to functionalization of the nanotube walls.

2001-12-18

71

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

72

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

SciTech Connect

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

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

2010-02-10

73

Adsorption of basic dyes from aqueous solution onto activated carbons  

Microsoft Academic Search

The aim of this research is to compare the adsorption capacity of different types of activated carbons produced by steam activation in small laboratory scale and large industrial scale processes. Equilibrium behaviour of the activated carbons was investigated by performing batch adsorption experiments using bottle-point method. Basic dyes (methylene blue (MB), basic red (BR) and basic yellow (BY)) were used

Emad N. El Qada; Stephen J. Allen; Gavin M. Walker

2008-01-01

74

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

PubMed

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

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

1999-04-23

75

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

76

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

77

27 CFR 19.328 - Wash water.  

Code of Federal Regulations, 2010 CFR

...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 therefrom may be run into a wash tank or a...

2010-04-01

78

When and How to Wash Your Hands  

MedlinePLUS

... gov Share Compartir When & How to Wash Your Hands When should you wash your hands? Before, during, and after preparing food Before eating ... After touching garbage How should you wash your hands? Wet your hands with clean, running water (warm ...

79

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

80

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

81

7 CFR 58.429 - Washing machine.  

...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

82

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

83

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

84

Adsorption of Pb(II) from aqueous solutions using activated carbon developed from Apricot stone  

Microsoft Academic Search

Low-cost activated carbon was prepared from Apricot stone material by chemical activation with sulphuric acid for the adsorption of Pb(II) from dilute aqueous solution. The activated carbon developed shows substantial capacity to adsorb Pb(II) from dilute aqueous solutions. The parameters studied include physical and chemical properties of adsorbent, pH, adsorbent dose, contact time and initial concentrations. The percent removal increased

Lotfi Mouni; Djoudi Merabet; Abdelkrim Bouzaza; Lazhar Belkhiri

2011-01-01

85

Removal of toxic chromium(VI) from aqueous solution by activated carbon using Casuarina equisetifolia  

Microsoft Academic Search

Highly activated carbon from the seed husk of Casuarina Casuarinas equisetifolia, a worldwide famous plant, have been prepared and tested for the removal of toxic Cr(VI) from its aqueous solution. The adsorbent was investigated for influences of initial chromium concentration (75, 100, 125, and 150 mg l), pH, contact time, and quantity of carbon on removal of Cr(VI) from aqueous solution at

A. El Nemr; A. El Sikaily; A. Khaled; O. Abdelwahab

2007-01-01

86

Effect of organic acids on the determination of carbonate species in solutions  

Microsoft Academic Search

Accurate analysis of carbonate species in natural waters is important for diagenetic modelling and oilfield inorganic chemical scale precipitation estimation. The concentration of carbonate species is often measured by titration. Errors can occur when organic acids are present in the solution due to the titration end points not being clearly identified. In this paper a method is presented for the

Yuping Zhang; Richard Dawe

1996-01-01

87

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

88

Studies on solution-derived ceramic coatings for oxidation protection of carbon-carbon composites  

Microsoft Academic Search

Carbon-carbon composites have been coated with silica and zircon prepared by sol-gel technique and with methylsilsesquioxane, a preceramic polymer. The effect of processing parameters for preparation of the sols and coating procedure on coating morphology has been studied. Oxidation behaviour of uncoated and coated carbon-carbon composites has been studied. Coatings with continuous and uniform structure, obtained by controlled processing, have

L. M. Manocha; Satish M. Manocha

1995-01-01

89

On the black carbon problem and its solutions  

Microsoft Academic Search

Black carbon (BC) warms air temperatures in at least seven major ways: (a) directly absorbing downward solar radiation, (b) absorbing upward reflected solar radiation when it is situated above bright surfaces, such as snow, sea ice, and clouds, (c) absorbing some infrared radiation, (d) absorbing additional solar and infrared radiation upon obtaining a coating, (e) absorbing radiation multiply reflected within

M. Z. Jacobson

2010-01-01

90

Kinetic study of pyrite oxidation in basic carbonate solutions  

Microsoft Academic Search

The general goal of this experimental study was to find ways to control the unwanted oxidation of pyrite during the in situ leaching of uranium ores. The authors investigated the effect of particle size, leaching pH, flow rate, total carbonate concentration, and cation type of column leaching rates. The work appears to be the first dealing with pyrite leaching in

Terry R. Guilinger; Robert S. Schechter; Larry W. Lake

1987-01-01

91

Ecological Engineering promotes Carbon Reduction Solutions for a Sustainable Planet  

Microsoft Academic Search

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

Stephen Bedford Clark

2009-01-01

92

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...

93

Conductometric determination of carbon in uranium carbide and its solution in nitric acid.  

PubMed

A simple but accurate method has been developed for the determination of carbon in uranium carbide powders/pellets as well as in solutions of uranyl nitrates. The methodology involves quantitative conversion of carbon present in the sample to carbon dioxide that is subsequently absorbed in a dilute solution of barium hydroxide. The conductivity shift of the barium hydroxide solution is monitored on-line continuously using a laboratory-built PC-based conductivity measurement system that has been developed in-house based on the direct conversion of conductance to the digital pulse frequency. A new gas absorption cell has been designed to ensure quantitative absorption during the residence time of the gas in the cell. The method is sensitive, accurate and precise to 1-3% at 600-1000 mug of carbon in samples of uranium carbide. PMID:18968049

Ahmed, M K; Geetha, R; Pandey, N K; Murugesan, S; Koganti, S B; Saha, B; Sahoo, P; Sundararajan, M K

2000-08-16

94

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

PubMed

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

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

2012-11-27

95

Studies of individual carbon sites of proteins in solution by natural abundance carbon 13 nuclear magnetic resonance spectroscopy. Relaxation behavior.  

PubMed

The aromatic regions in proton-decoupled natural abundance 13C Fourier transform nuclear magnetic resonance spectra (at 14.2 kG) of small native proteins contain broad methine carbon bands and narrow nonprotonated carbon resonances. Some factors that affect the use of natural abundance 13C Fourier transform NMR spectroscopy for monitoring individual nonprotonated aromatic carbon sites of native proteins in solution are discussed. The effect of protein size is evaluated by comparing the 13C NMR spectra of horse heart ferrocytochrome c, hen egg white lysozyme, horse carbon monoxide myoglobin, and human adult carbon monoxide hemoglobin. Numerous single carbon resonances are observed in the aromatic regions of 13C NMR spectra of cytochrome c, lysozyme, and myoglobin. The much larger hemoglobin yields few resolved individual carbon resonances. Theoretical and some experimental values are presented for the natural linewidths (W), spin-lattice relaxation times (T1), and nuclear Overhauser enhancements (NOE) of nonprotonated aromatic carbons and Czeta of arginine residues. In general, the 13C-1H dipolar mechanism dominates the relaxation of these carbons. 13C-14N dipolar relaxation contributes significantly to 1/T1 of C epsilon2 of tryptophan residues and Czeta of arginine residues of proteins in D2O. The NOE of each nonprotonated aromatic carbon is within experimental error of the calculated value of about 1.2. As a result, integrated intensities can be used for making a carbon count. Theoretical results are presented for the effect of internal rotation on W, T1, and the NOE. A comparison with the experimental T1 and NOE values indicates that if there is internal rotation of aromatic amino acid side chains, it is not fast relative to the over-all rotational motion of the protein. PMID:169239

Oldfield, E; Norton, R S; Allerhand, A

1975-08-25

96

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

97

Solution processable carbon nanotube network thin-film transistors operated in electrolytic solutions at various pH  

NASA Astrophysics Data System (ADS)

We investigate the electronic properties of solution-gated carbon nanotube (CNT) thin-film transistors, where the active layer consists of a randomly distributed single-walled CNT network of >90% semiconducting nanotubes, deposited from an aqueous solution by spin-coating. The devices are characterized in different electrolytic solutions, where a reference electrode immersed in the liquid is used to apply the gate potential. We observe a gate-potential shift in the transfer characteristic when the pH and/or ionic strength of the electrolytic solution is changed with a pH sensitivity of ?19 mV/pH. This sensitivity is attributed to a surface charging effect at the CNT/electrolyte interface.

Haeberle, Tobias; Münzer, Alexandra M.; Buth, Felix; Antonio Garrido, Jose; Abdellah, Alaa; Fabel, Bernhard; Lugli, Paolo; Scarpa, Giuseppe

2012-11-01

98

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

99

Washing Fresh Fruits and Vegetables  

E-print Network

. Also wash and sanitize all countertops, cutting boards and utensils (including fruit/ vegetable brushes) with a mixture of 1 teaspoon chlorine bleach in 1 quart of water. Do this before and after preparing food. When washing fresh produce... and vegetables before preparing them ? even if the skin or rind will not be eaten. This prevents patho- gens from being transferred from the rind or skin to the inside of the fruit or vegetable when it is cut. To prevent spoilage and mold growth during...

Scott, Amanda

2008-09-05

100

Methods of pretreating comminuted cellulosic material with carbonate-containing solutions  

DOEpatents

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

Francis, Raymond

2012-11-06

101

Galvanic Corrosion of a Carbon Steel-Stainless Steel Couple in Sulfide Solutions  

NASA Astrophysics Data System (ADS)

The galvanic corrosion behavior of carbon steel-stainless steel couples with various cathode/anode area ratios was investigated in S 2--containing solutions, which were in equilibrium with air, by electrochemical measurements, immersion test, and surface characterization. It is found that the galvanic corrosion effect on carbon steel anode increases with the cathode/anode area ratios, and decreases with the increasing concentration of S2- in the solution. A layer of sulfide film is formed on carbon steel surface, which protects it from corrosion. When the cathode/anode area ratio is 1:1, the potentiodynamic polarization curve measurement and the weight-loss determination give the identical measurement of the galvanic corrosion effect. With the increase of the cathode/anode area ratio, the electrochemical method may not be accurate to determine the galvanic effect. The anodic dissolution current density of carbon steel cannot be approximated simply with the galvanic current density.

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

2011-12-01

102

Adsorption of Basic Violet 14 in aqueous solutions using KMnO4-modified activated carbon.  

PubMed

In this paper, an activated carbon was prepared from Typha orientalis and then treated with KMnO(4) and used for the removal of Basic Violet 14 from aqueous solutions. KMnO(4) treatment influenced the physicochemical properties of the carbon and improved its adsorption capacity. Adsorption experiments were then conducted with KMnO(4)-modified activated carbon to study the effects of carbon dosage (250-1500 mg/L), pH (2-10), ion strength (0-0.5 mol/L), temperature, and contact time on the adsorption of Basic Violet 14 from aqueous solutions. The equilibrium data were analyzed by the Langmuir and Freundlich isotherms and fitted well with the Langmuir model. The pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were used to evaluate the kinetic data and the pseudo-second-order kinetics was the best with good correlation. PMID:20036370

Shi, Qianqian; Zhang, Jian; Zhang, Chenglu; Nie, Wei; Zhang, Bo; Zhang, Huayong

2010-03-01

103

Abdominopelvic washings: A comprehensive review  

PubMed Central

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

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

2013-01-01

104

Removal of Acid Dyes from Aqueous Solutions using Chemically Activated Carbon  

Microsoft Academic Search

Textile dyes (Acid Yellow 17 and Acid Orange 7) were removed from its aqueous solution in batch and continuous packed bed adsorption systems by using thermally activated Euphorbia macroclada carbon with respect to contact time, initial dye concentration, and temperature. The activated carbon was prepared using a cheap plant-based material called Euphorbia macroclada, which was chemically modified with K2CO3. Lagergren-first-order

Özgül Gerçel; H. Ferdi Gerçel

2009-01-01

105

Phosphate Removal from Aqueous Solution Using Coir-Pith Activated Carbon  

Microsoft Academic Search

The present study deals with the removal of phosphates from aqueous solution using activated carbon developed from coir pith. Batch adsorption experiments were performed to delineate the effect of initial pH, contact time, adsorbent dose and temperature on the removal of phosphates by coir-pith activated carbon (CAC) (activated by H2SO4). The removal was found to be maximum in the pH

Pradeep Kumar; S. Sudha; Shri Chand; Vimal Chandra Srivastava

2010-01-01

106

Computational investigation of carbon dioxide absorption in alkanolamine solutions.  

PubMed

We investigated CO2 absorption in aqueous alkanolamine solutions using density functional theory with dielectric continuum solvation models (SMD/IEF-PCM and COSMO-RS). We varied the alkyl chain length (m?=?2, 3, 4) and the alcohol chain length (n?=?2, 3, 4) in the alkanolamine structures, H(CH2) m NH(CH2) n OH. Using the SMD/IEF-PCM/B3LYP/6-311++G(d,p) and COSMO-RS/BP/TZVP levels of theory, our calculations predict that the product of CO2 absorption (carbamate or bicarbonate) is strongly affected by the alcohol length but does not differ significantly by varying the alkyl chain length. This prediction was confirmed experimentally by (13)C-NMR. The observed sensitivity to the alcohol chain length can be attributed to hydrogen bonding effects. The intramolecular hydrogen bonds of HN · · · HO, NH2 (+) · · · OH, and NCOO(-) · · · HO induce ring structure formation in neutral alkanolamines, protonated alkanolamines, and carbamate anions, respectively. The results from our studies demonstrate that intramolecular hydrogen bonds play a key role in CO2 absorption reactions in aqueous alkanolamine solutions. PMID:23306736

Yamada, Hidetaka; Matsuzaki, Yoichi; Chowdhury, Firoz; Higashii, Takayuki

2013-10-01

107

The effect of phosphoric acid on the absorption of carbon dioxide into solutions of methyldiethanolamine  

E-print Network

the coabsorption of COz into MDEA solutions. The absorption of carbon dioxide into aqueous MDEA solutions is a mass- transfer process from the gas phase to the liquid phase followed by a chemical reaction. Several researchers, including Tomcej et ah (1989... the carbon dioxide reaction. The objective of this study is to determine whether the addition of small amounts of phosphoric acid (HsPO4) to aqueous MDEA will reduce the rate of CO2 absorption. This will be accomplished by determining comparative kinetic...

Cordi, Eric Marshall

2012-06-07

108

High-performance thin-film transistors produced from highly separated solution-processed carbon nanotubes  

NASA Astrophysics Data System (ADS)

Transistors utilizing carbon nanotube (CNT) thin films have exhibited high on-currents and mobilites greater than those of alternative channel materials. One critical problem that has limited the utilization of CNT thin-film transistors (TFTs) is the occurrence of unavoidable parasitic current paths stemming from metallic nanotubes. In this work, we experimentally demonstrate high-yield, high-performance TFTs composed of a highly purified single-walled carbon nanotube (SWNT) network. A solution process for a highly separated 99.9% semiconducting SWNT solution is used to acquire a significant enhancement in transistor performance, such as a high on/off ratio, high mobility, and high yields close to 100%.

Lee, Dongil; Seol, Myeong-Lok; Moon, Dong-Il; Bennett, Patrick; Yoder, Nathan; Humes, Jefford; Bokor, Jeffrey; Choi, Yang-Kyu; Choi, Sung-Jin

2014-04-01

109

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

110

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

111

Inhibition of carbon steel corrosion by azathione derivatives in organic acid solutions  

Microsoft Academic Search

Purpose – The purpose of this paper is to investigate the inhibitive effect of azathiones, namely cyclopentyl-tetrahydro-azathione, cyclohexyl-tetrahydro-azathione and isobutyl-methyl-tetrahydro-azathione on the corrosion of carbon steel in formic and acetic acid solution. The effect of inhibitor concentration, immersion time, acid concentration, and solution temperature on the inhibition efficiencies of the selected azathiones were studied systematically. Design\\/methodology\\/approach – The synthesis of

Sadaf Khan; M. Z. A. Rafiquee; Nidhi Saxena; M. A. Quraishi

2009-01-01

112

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

113

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

PubMed

The combined elimination of NO and SO(2) can be realized by hexamminecobalt(II) solution which is formed by adding soluble cobalt(II) salt into the aqueous ammonia solution. Activated carbon is used as a catalyst to regenerate hexamminecobalt(II), Co(NH(3))(6)(2+), so that NO removal efficiency can be maintained at a high level for a long time. In this study, KOH solution has been explored to modify coconut activated carbon to meliorate its catalytic performance in the reduction of hexamminecobalt(III), Co(NH(3))(6)(3+). The experiments have been performed in a batch stirred cell to investigate the effects of KOH concentration, impregnation duration, activation temperature and activation duration on the performance of activated carbon. The results show that the best KOH concentration for the improvement of activated carbon is 0.5 mol l(-1). The optimal impregnation duration is 9h. High temperature is favorable to ameliorating the catalytic performance of activated carbon. The optimum activation duration is 4h. PMID:21555182

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

2011-07-15

114

Mutvei's solution: An ideal agent for resolving microgrowth structures of biogenic carbonates  

E-print Network

illumination) and scanning electron microscopy can be used to analyze the microgrowth structures. WeMutvei's solution: An ideal agent for resolving microgrowth structures of biogenic carbonates Bernd as environmental and physiological proxies, and growth increments as calendars. Recognition of growth structures

Schöne, Bernd R.

115

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

E-print Network

water (If desired, carbon dioxide can be removed by boiling and allowing to cool in a stream of nitrogen procedure is carried out for each solution prepared: · Weigh out the necessary amount of salt in a small water, filling from the bottom of the flask through a piece of tubing. · Using a funnel, transfer

116

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

SciTech Connect

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

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

2008-08-15

117

Partial molar volume reduction of solvent for solute crystallization using carbon dioxide as antisolvent  

Microsoft Academic Search

The gas antisolvent crystallization (GASC) process using dense carbon dioxide (CO2) as antisolvent is particularly useful for purification and micronization of thermo-labile bioactive solid substances. Conventionally, the GASC process is characterized by the relative total volume expansion or the relative molar volume expansion of the solution. A new criterion is proposed in this work in terms of the relative partial

Mamata Mukhopadhyay

2003-01-01

118

Washing Machine Dehydration Dynamics Analysis  

Microsoft Academic Search

This paper presents how an FEA model using MSC.NASTRAN was developed to simulate dehydration dynamics of a washing machine with spinning basket rotating about vertical axis. Gyroscopic effect centrifugal forces and self?balancing mechanism (liquid balancer associated with rotating structures were considered in the simulation. Using the model frequency response analysis was performed to simulate response of non?rotating structures in operating

Morio MITSUISHI Morio MITSUISHI; Changmin SONG Changmin SONG; Changmin SAMSUNG; Changsub KIM; Changsub SAMSUNG

119

Dioxin removal from contaminated soils by ethanol washing.  

PubMed

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

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

2010-07-15

120

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

121

Selective removal of cadmium from mixed metal solution by carbonate infusion  

SciTech Connect

The purpose of this study is to develop the technology of selective precipitation of a single metal from a mixed solution by carbonate infusion. Experiments were conducted in Pyrex reactors and jar testers. Synthetic wastewater of cadmium and copper mixed solution was used in this study. Initial cadmium and copper concentrations were 10{sup {minus}5}, 10{sup {minus}4}, 10{sup {minus}3} M, which are the concentrations commonly occurring in electroplating rinsewater. The effects of pH, carbonate concentration, and mixing rate on copper and cadmium hydrolysis were investigated. The optimum conditions of selective precipitation for the cadmium form mixed solutions were around pH 9, and the mixing rate was 100 rpm.

Cho, S.H.; Young, K.K. (Ajou Univ. Suwon (Korea))

1991-01-01

122

Evaluation of a PCR based assay for specific detection of Campylobacter jejuni in chicken washes.  

PubMed

An assay for Campylobacter jejuni based on the polymerase chain reaction was developed in our laboratory and shown to be a sensitive and specific method to identify this bacterium in pure culture. This assay was evaluated as a method to rapidly detect C. jejuni attached to chicken carcasses. Chicken carcasses were sampled for PCR using three methods including pre-enrichment of the washes, direct plating of the washes and differential centrifugation of the washes prior to testing. It was found that plating the wash solutions on Campy Cefex plates prior to performing PCR was the most specific and reliable of the three treatment methods evaluated. PMID:8569769

Winters, D K; Slavik, M F

1995-10-01

123

Fabrication of carbonate apatite blocks from set gypsum based on dissolution-precipitation reaction in phosphate-carbonate mixed solution.  

PubMed

Carbonate apatite (CO3Ap), fabricated by dissolution-precipitation reaction based on an appropriate precursor, is expected to be replaced by bone according to bone remodeling cycle. One of the precursor candidates is gypsum because it shows self-setting ability, which then enables it to be shaped and molded. The aim of this study, therefore, was to fabricate CO3Ap blocks from set gypsum. Set gypsum was immersed in a mixed solution of 0.4 mol/L disodium hydrogen phosphate (Na2HPO4) and 0.4 mol/L sodium hydrogen carbonate (NaHCO3) at 80-200°C for 6-48 h. Powder X-ray diffraction patterns and Fourier transform infrared spectra showed that CO3Ap block was fabricated by dissolution-precipitation reaction in Na2HPO4-NaHCO3 solution using set gypsum in 48 h when the temperature was 100°C or higher. Conversion rate to CO3Ap increased with treatment temperature. CO3Ap block containing a larger amount of carbonate was obtained when treated at lower temperature. PMID:24614998

Nomura, Shunsuke; Tsuru, Kanji; Maruta, Michito; Matsuya, Shigeki; Takahashi, Ichiro; Ishikawa, Kunio

2014-01-01

124

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

125

Preparation of activated mesoporous carbons for electrosorption of ions from aqueous solutions  

SciTech Connect

Mesoporous carbon with a narrow pore size distribution centered at about 9 nm, which was prepared by self assembly of block copolymer and phloroglucinol-formaldehyde resin via the soft-template method, was activated by CO{sub 2} and potassium hydroxide (KOH). The effects of activation conditions, such as the temperature, activation time, and mass ratio of KOH/C, on the textural properties of the resulting activated mesoporous carbons were investigated. Activated mesoporous carbons exhibit high BET specific surface areas (up to {approx} 2000 m{sup 2} g{sup -1}) and large pore volumes (up to {approx} 1.6 cm{sup 3} g{sup -1}), but still maintain a highly mesoporous structure. Heat treatment of mesoporous carbons by CO{sub 2} generally requires a moderate to high extent of activation in order to increase its BET surface area by 2-3 times, while KOH activation needs a much smaller degree of activation than the former to reach an identical surface area, ensuring high yields of activated mesoporous carbons. In addition, KOH activation allows a controllable degree of activation by adjusting the mass ratio of KOH/C (2-8), as evidenced by the fact that surface area and pore volume increase with the mass ratio of KOH/C. The electrosorption properties of activated mesoporous carbons were investigated by cyclic voltammetry in 0.1 M NaCl aqueous solutions. Upon activation, the electrosorption capacitance of activated mesoporous carbons was greatly enhanced.

Dai, Sheng [ORNL; Lee, Jeseung [ORNL; Tsouris, Costas [ORNL; DePaoli, David W [ORNL; Wang, Xiqing [ORNL

2010-01-01

126

Washing and caustic leaching of Hanford Tank C-106 sludge  

SciTech Connect

This report describes the results of a laboratory-scale washing and caustic leaching test performed on sludge from Hanford Tank C-106. The purpose of this test was to determine the behavior of important sludge components when subjected to washing with dilute or concentrated sodium hydroxide solutions. The results of this laboratory-scale test were used to support the design of a bench-scale washing and leaching process used to prepare several hundred grams of high-level waste solids for vitrification tests to be done by private contractors. The laboratory-scale test was conducted at Pacific Northwest Laboratory in FY 1996 as part of the Hanford privatization effort. The work was funded by the US Department of Energy through the Tank Waste Remediation System (TWRS; EM-30).

Lumetta, G.J.; Wagner, M.J.; Hoopes, F.V.; Steele, R.T.

1996-10-01

127

Comparative alkali washing of simulated radioactive sludge  

SciTech Connect

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

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

1996-10-01

128

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

129

TANK 4 CHARACTERIZATION, SETTLING, AND WASHING STUDIES  

SciTech Connect

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

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

2009-09-29

130

Removal of Heavy Metal Ions and Diethylenetriamine Species from Solutions by Magnetic Activated Carbon  

NASA Astrophysics Data System (ADS)

Even though activated carbon is widely used in the removal of contaminants from effluents, it is difficult to be completely recovered by screening or classification. In this project, we prepared a magnetic form of activated carbon (M-AC) by co-precipitation of iron oxides onto activated carbon surface. M-AC can be separated from solutions by applying an external magnetic field and regenerated for reuse. The synthesized M-AC was characterized by X-ray diffraction, specific surface area measurement, and scanning electron microscope. Characterization results show that the major phase of coated iron oxides is magnetite (Fe 3O4). Batch adsorption experiments were carried out for single-component and multi-component solutions. M-AC shows a better adsorption capacity for singlecomponent of Cu (II), Ni (II), or diethylenetriamine (DETA) and for multiple-components of Cu-DETA and Ni-DETA complexes in deionized water than activated carbon. M-AC also shows the potential application in carbon-in-pulp process for gold recovery.

Liu, Kaiwen

131

Kinetics of diuron and amitrole adsorption from aqueous solution on activated carbons.  

PubMed

A study was conducted on the adsorption kinetics of diuron and amitrole from aqueous solutions on activated carbons of different particle sizes and on an activated carbon fiber. Different kinetic models were applied to the experimental results obtained. A pseudo-second-order rate equation fitted the adsorption kinetics data better than a pseudo-first-order rate equation. Amitrole showed faster adsorption kinetics compared with diuron because of the smaller size of the former herbicide, despite its lower driving force for adsorption. Both reaction rate constants increased when the particle size decreased. The activated carbon fiber and the activated carbon of smallest particle size (0.03 mm) showed similar adsorption kinetics. The intraparticle diffusion rate constant increased with higher initial concentration of herbicides in solution and with lower particle size of the adsorbent. This is because the rise in initial concentration increased the amount adsorbed at equilibrium, and the reduction in particle size increased the number of collisions between adsorbate and adsorbent particles. Demineralization of the activated carbon with particle size of 0.5mm had practically no effect on the adsorption kinetics. PMID:18241982

Fontecha-Cámara, M A; López-Ramón, M V; Pastrana-Martínez, L M; Moreno-Castilla, C

2008-08-15

132

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

PubMed

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

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

2014-04-01

133

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

134

Static and dynamic adsorption of phenol from aqueous solution using spherical carbon  

NASA Astrophysics Data System (ADS)

The objective of this work is to evaluate spherical carbon and modified spherical carbon for the removal of phenol from aqueous solution in static and dynamic studies under various conditions. It explores mainly two adsorbents, that is, activated spherical carbon (ASC) and modified activated spherical carbon (SSC). SEM characterization of both the adsorbents showed a clear change in the physical and chemical properties of the modified adsorbent from its precursor activated carbon. Both the adsorbents are subjected to static mode adsorption studies and after a comparison based on isotherm analysis; more efficient adsorbent is screened for column mode adsorption studies. The phenol removal increased for modified carbon. The aim of carrying out column mode studies will aid in ascertaining the practical applicability of the adsorbent in the real system and therefore, to assess the effect of various process variables, viz., bed height of the adsorbent, flow rate and initial concentration of the adsorbate on breakthrough time and adsorption capacity. The column studies generated data were modeled using the empirical relationship based on Bohart-Adams model. At the end, the option of regenerating the adsorbent was also explored using sodium hydroxide with the aim of minimize the hazardous generated and also to reuse the adsorbent material for many cycles without affecting original properties. Adsorbent regeneration efficiency of 72% was achieved. This investigation reveals that the material used as an adsorbent is very effective with high adsorption capacities and also possible to use in the real contaminated system.

Bhargavi, R.; Kadirvelu, K.; Kumar, N. S.

2013-06-01

135

Region-selective self-assembly of functionalized carbon allotropes from solution.  

PubMed

Approaches for the selective self-assembly of functionalized carbon allotropes from solution are developed and validated for 0D-fullerenes, 1D-carbon nanotubes and 2D-graphene. By choosing the right molecular interaction of self-assembled monolayers (serving the surface) with the functionalization features of carbon materials, which provide the solubility but also serve the driving force for assembly, we demonstrate a region-selective and self-terminating assembly of the materials. Active layers of the carbon allotropes can be selectively deposited in the channel region of thin-film transistor (TFT) devices by this approach. As an example for a 0D system, molecules of C60 functionalized octadecylphosphonic acids are used to realize self-assembled monolayer field-effect transistors (SAMFETs) based on a selective molecular exchange reaction of stearic acid in the channel region. For noncovalently functionalized single-walled carbon nanotubes (SWCNTs) and graphene oxide (GO) flakes, the electrostatic Coulomb interactions between the functional groups of the carbon allotropes and the charged head groups of a SAM dielectric layer are utilized to implement the selective deposition. PMID:24274682

Wang, Zhenxing; Mohammadzadeh, Saeideh; Schmaltz, Thomas; Kirschner, Johannes; Khassanov, Artoem; Eigler, Siegfried; Mundloch, Udo; Backes, Claudia; Steinrück, Hans-Georg; Magerl, Andreas; Hauke, Frank; Hirsch, Andreas; Halik, Marcus

2013-12-23

136

Light-controlled single-walled carbon nanotube dispersions in aqueous solution.  

PubMed

We have succeeded in dispersing single-walled carbon nanotubes (SWNTs) into an aqueous solution of poly(ethylene glycol)-terminated malachite green derivative (PEG-MG) through simple sonication. It was found that UV exposure caused reaggregation of these predispersed SWNTs in the same aqueous medium, as adsorbed PEG-MG photochromic chains could be effectively photocleavaged from the nanotube surface. The observed light-controlled dispersion and reaggragation of SWNTs in the aqueous solution should facilitate the development of SWNT dispersions with a controllable dispersity for potential applications. PMID:18672920

Chen, Senlin; Jiang, Yugui; Wang, Zhiqiang; Zhang, Xi; Dai, Liming; Smet, Mario

2008-09-01

137

Bacterial profile of ground beef made from carcass tissue experimentally contaminated with pathogenic and spoilage bacteria before being washed with hot water, alkaline solution, or organic acid and then stored at 4 or 12 degrees C.  

PubMed

The long-term effectiveness of several beef-carcass surface-tissue (BCT) wash interventions on the microbiology of ground beef produced from this tissue was determined. BCT was inoculated with bovine feces containing one of two different levels (ca. 4 or 6 log CFU/ml) of Escherichia coli O157:H7, Listeria innocua, Salmonella typhimurium, and Clostridium sporogenes. The BCT was then subjected to one of several treatment washes: 2% (vol/vol) DL-lactic acid (LA), 2% (vol/vol) acetic acid (AA), 12% (wt/vol) trisodium phosphate (TSP), hot water (HW; 74 +/- 2 degrees C at the tissue surface), or water (WW; 32 +/- 2 degrees C at the tissue surface). A control group was left untreated. After treatments, BCT was held at 4 degrees C for 24 h and then ground. The ground beef was packaged and incubated at 4 degrees C for 21 days or 12 degrees C for 3 days. AA-treated samples held at 12 degrees C for 3 days yielded significantly lower aerobic plate counts than the control and also yielded the lowest levels of pseudomonads when compared to other sample groups. After being held at 4 degrees C for 21 days or 12 degrees C for 3 days, samples treated with antimicrobial compounds had lower or no detectable (< 1 CFU/g) levels of E. coli O157:H7, L. innocua, S. typhimurium, and C. sporogenes than beef treated with a WW or the control. Ground beef produced from tissue treated with HW yielded lower populations of these bacteria when compared to WW or untreated control beef, but the populations were generally higher than those observed in any of the antimicrobial chemical-treated samples. These trends continued throughout all storage conditions over time. Results from this study indicate that the use of carcass interventions, especially antimicrobial compounds, presently available to the slaughter industry will lower bacterial counts in ground beef. PMID:9766060

Dorsa, W J; Cutter, C N; Siragusa, G R

1998-09-01

138

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

SciTech Connect

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

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

1996-12-31

139

Surface-enhanced Raman spectroelectrochemical studies of corrosion films on iron in aqueous carbonate solution  

SciTech Connect

The corrosion films on iron in aqueous carbonate/bicarbonate solutions were studied as a function of concentration, pH, and temperature by using the technique of surface-enhanced Raman spectroscopy with electrodeposited silver. Both Fe(OH){sub 2} and Fe{sub 3}O{sub 4} were detected in the surface oxide film at prepassivation potentials. Iron carbonate (siderite) was observed in the corrosion film in a limited pH, temperature, and applied potential range. At lower carbonate/bicarbonate concentration (e.g., 0.01 M), passivation was lost, and continuous anodic dissolution of the iron occurred. The cathodic reduction of the corrosion film was enhanced at 75 C.

Simpson, L.J.; Melendres, C.A. [Argonne National Lab., IL (United States)

1996-07-01

140

Inhibition of the corrosion of low carbon steel in acidic solution by selected polyelectrolytes and polymers  

Microsoft Academic Search

The inhibiting effects of 2,6-ionen and 2,10-ionen type polyvinylbenzyltrimethylammonium chloride, and latex, on low carbon steel in hydrochloric acid solution was investigated by potentiodynamic polarisation measurements and impedance measurement techniques over the temperature range of 20-60°C at different inhibitor concentrations. It was found that the inhibition efficiencies increased with increasing inhibitor concentration. The degree of shift in Ecorr values, together

G. Bereket; A. Yurt; H. Türk

2003-01-01

141

The breakdown mechanism of diamond-like carbon coated nickel in chloride solution  

Microsoft Academic Search

The breakdown mechanism of chemical vapor deposited nickel (CVD Ni) coated with 5 micrometers of diamond-like carbon (DLC) produced by plasma source ion implantation (PSII) in chloride solution was investigated. PSII differs from traditional implantation techniques in that the targets are placed directly in a plasma source and then pulse biased to produce a non-line-of-sight process to complex-shaped targets without

R. S. Lillard; D. P. Butt; T. N. Taylor; K. C. Walter; M. Nastasi

1997-01-01

142

A moving-boundary problem for concrete carbonation: Global existence and uniqueness of weak solutions  

Microsoft Academic Search

This paper deals with a one-dimensional coupled system of semi-linear parabolic equations with a kinetic condition on the moving boundary. The latter furnishes the driving force for the moving boundary. The main result is a global existence and uniqueness theorem of positive weak solutions. The system under consideration is modelled on the so-called carbonation of concrete – a prototypical chemical-corrosion

Adrian Muntean; Michael Böhm

2009-01-01

143

Thermal stability and hydrophobicity enhancement of wood through impregnation with aqueous solutions and supercritical carbon dioxide  

Microsoft Academic Search

A novel process for the thermal stability and hydrophobicity enhancement of wood is proposed. The process concerns the impregnation\\u000a of wood with water-soluble and water-insoluble salts. The salts are synthesized in situ in wood through aqueous solutions\\u000a and supercritical carbon dioxide treatment. To protect salt-treated wood from absorbing large amounts of humidity a polymer\\u000a film is formed upon the surface

Costas Tsioptsias; Costas Panayiotou

2011-01-01

144

Adsorption kinetics of a basic dye from aqueous solutions onto apricot stone activated carbon  

Microsoft Academic Search

The preparation of activated carbon from apricot stone with H2SO4 activation and its ability to remove a basic dye, astrazon yellow 7GL, from aqueous solutions were reported in this study. The adsorbent was characterized by FTIR, BET and SEM, respectively. The effects of various experimental parameters, such as initial dye concentration, pH, adsorbent dosage and temperature were investigated in a

E. Demirbas; M. Kobya; M. T. Sulak

2008-01-01

145

Activated carbon from coconut coirpith as metal adsorbent: adsorption of Cd(II) from aqueous solution  

Microsoft Academic Search

Activated carbon prepared from coirpith, an agricultural solid waste by-product, has been used for the adsorption of Cd(II) from aqueous solution. Parameters such as the agitation time, metal ion concentration, adsorbent dose and pH were studied. The adsorption data fit well with the Langmuir and Freundlich isotherm models. The adsorption capacity (Q0) calculated from the Langmuir isotherm was 93.4 mg

K. Kadirvelu; C. Namasivayam

2003-01-01

146

Coconut (Cocos Nucifera) Shell Based Activated Carbon for the Removal of Malachite Green Dye From Aqueous Solutions  

Microsoft Academic Search

The adsorption of malachite green (MG) dye using coconut shell based activated carbon (CSAC) was investigated. Operational factors such as effect of pH, initial dye concentration, adsorbent dosage, contact time, and solution temperature on the adsorption process were studied. Solution pH strongly affected the chemistry of both the dye molecule and CSAC in solution. Optimum dye removal was obtained at

Olugbenga Solomon Bello; Mohd Azmier Ahmad

2012-01-01

147

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

148

OPTIMIZATION OF THE WASH-OFF METHOD FOR MEASURING AEROSOL CONCENTRATIONS  

EPA Science Inventory

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

149

Nature of Non-Fickian Solute Transport in Complex Heterogeneous Porous Media - Carbonates  

NASA Astrophysics Data System (ADS)

Despite the range of significant practical applications of solute transport, including the long-term fate of nuclear waste repositories, secure storage of CO2 and improved oil recovery, even the qualitative behavior of most rocks is uncertain: vast carbonate sedimentary basins contain more than half the world's current oil reserves yet experimental data on transport in carbonates is scant. The relationship between pore structure, velocity field and transport remains unknown, particularly for heterogeneous carbonates. We simulate solute transport through 3D ?-CT images of different rock samples, representing geological media of increasing pore-scale complexity: a sandpack, a Berea sandstone and a Portland limestone. A finite-difference Stokes solver is employed to compute the flow field and transport particles semi-analytically along streamlines to represent advection with a random motion to model diffusion. We predict the propagators measured on similar cores in Nuclear Magnetic Resonance (NMR) experiments. Dispersion coefficient dependence on Peclet number is shown to have different scaling for complex carbonates. The behavior is explained using continuous time random walks with a truncated power-law distribution of travel times: transport is qualitatively different for the complex limestone compared to the sandstone or sandpack, with long tailing, an almost immobile peak concentration and a very slow approach to asymptotic dispersion. We demonstrate the different nature of non-Fickian transport in carbonates by analyzing the transit time probabilities ?(?) of traveling between two neighboring voxels for Portland carbonate that show an approximately power-law dependence of travel times ?(?) ~ ? -1-? with a slope corresponding to ? = 0.7, as shown in Fig.1. The comparison with ?(?) of the sandpack and Berea sandstone for Pe = ? indicates quantitatively different generic behavior, as the sandpack and sandstone have slope corresponding to ? = 1.8 (two solid parallel lines in the insert in Fig.1). This complex non-Fickian behavior at the pore scale has large implications on modeling of field-scale transport.

Bijeljic, B.; Mostaghimi, P.; Blunt, M. J.

2011-12-01

150

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

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

151

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

152

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

PubMed

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

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

2012-10-30

153

Solution-processed flexible transparent conductors based on carbon nanotubes and silver grid hybrid films  

NASA Astrophysics Data System (ADS)

In a simple, cost-effective, and solution-based process, a thin-film of single-walled carbon nanotubes is hybridized on a PET film which has been patterned with solution self-assembled Ag nanoparticles. Such a flexible and transparent electrode exhibits a sheet resistance down to ~5.8 ? sq-1 at ~83.7% optical transmittance. The hybrid films are stable under ambient conditions and offer excellent bendability.In a simple, cost-effective, and solution-based process, a thin-film of single-walled carbon nanotubes is hybridized on a PET film which has been patterned with solution self-assembled Ag nanoparticles. Such a flexible and transparent electrode exhibits a sheet resistance down to ~5.8 ? sq-1 at ~83.7% optical transmittance. The hybrid films are stable under ambient conditions and offer excellent bendability. Electronic supplementary information (ESI) available: Experimental details, performance of graphene-Ag hybrid and met-SWNT-Ag hybrid films. See DOI: 10.1039/c3nr06386k

Wang, Jing; Zhang, Jintao; Sundramoorthy, Ashok Kumar; Chen, Peng; Chan-Park, Mary B.

2014-04-01

154

Lead removal via soil washing and leaching  

Microsoft Academic Search

A soil washing and leaching process was tested for removing lead from soils. A soil-washing circuit, including size and gravity\\u000a separations, was employed to remove the coarse metallic lead particles, while the leaching was applied to remove fine metallic\\u000a lead particles and other lead species. The soil-washing tests proved that the metallic lead particles larger than 0.15 mm\\u000a (100 mesh)

H. K. Lin; X. D. Man; D. E. Walsh

2001-01-01

155

Evaluation of detergents for washing fabrics  

Microsoft Academic Search

Various methods are used today to check the washing effect of detergents. They differ mainly in whether the cleaning assessment\\u000a is determined by the use of artificially soiled test fabrics, anonymous naturally soiled laundry in a single wash test, or\\u000a new family bundles in multiple use and wash test series. Correlation of the information based on the actual field behavior

H. Krüssmann

1978-01-01

156

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

157

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

158

Grafting of polyethylene by ?-radiation grafting onto conductive carbon black and application as novel gas and solute sensors  

NASA Astrophysics Data System (ADS)

?-Ray radiation grafting of polyethylene (PE) onto conductive carbon black under various conditions was investigated. In the case of 400 kGy dose of irradiation of PE-adsorbed carbon black at high temperatures near or above the melting point of PE, the grafting of PE onto the carbon black surface was successfully proceeded and the percentage of grafting exceeded 90%. Using the PE-grafted carbon black and PE, conductive composite prepared from PE-grafted carbon black and PE was prepared. The electric resistance of the composite largely increased when it was transferred from dry air to solvent vapor, such as carbon tetrachloride and cyclohexane. The electric resistance also clearly increased when the composite was immersed in n-hexane solution of tetrahydrofuran, chloroform and cyclohexane. Therefore, it was concluded that the conductive composite could be used as a novel sensor of solvent vapor and solute in n-hexane.

Chen, J.; Iwata, H.; Maekawa, Y.; Yoshida, M.; Tsubokawa, N.

2003-06-01

159

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

160

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

161

Americium and europium extraction from alkali and carbonate solutions with 2-hydroxy-5-alkylbenzyldiethanolamine  

SciTech Connect

Americium and europium extraction from alkali solutions in presence of tartrate and carbonate ions using 2-hydroxy-5-alkylbenzyldiethanolamine (DEAP) in different diluents as a function of NaOH, Na/sub 2/C/sub 4/H/sub 4/O/sub 6/, K/sub 2/CO/sub 3/, extractant and metal concentration, and pH of the medium has been studied. It was found that americium is extracted to the maximum by 1 M DEAP solution in hexane from tartrate solutions with an NaOH concentration not lower than 1 M and by 0.5-2.0 M K/sub 2/CO/sub 3/ solutions with a pH > 13. The highest americium-europium pair separation factors were obtained in the systems 0.1 M DEAP-0.01 M Na/sub 2/C/sub 4/H/sub 4/O/sub 6/-4.0 M NaOH and 0.1 MDEAP-1 M K/sub 2/CO/sub 3/ (pH = 12.05). The data obtained permit one to regard DEAP a potential extractant for TPE extraction and separation of propertywise similar elements in alkali solutions.

Karalova, Z.K.; Bukina, T.I.; Devirts, E.A.; Agaev, Z.Z.; Myasoedov, B.F.

1988-07-01

162

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

163

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

164

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

165

SOLVENT WASHING OF PCP CONTAMINATED SOILS WITH ANAEROBIC TREATMENT OF WASH FLUIDS  

EPA Science Inventory

A solvent washing procedure for the removal of pentachlorophenol (PCP) from contaminated soils is presented. his procedure can be used in both in-situ and above ground soil washing applications. he in-situ solvent washing (flushing) of soil was simulated by continuously flushing ...

166

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

Microsoft Academic Search

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

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

2007-01-01

167

Iron powder, graphite and activated carbon as catalysts for the oxidation of 4-chlorophenol with hydrogen peroxide in aqueous solution  

Microsoft Academic Search

Solid materials as iron powder, graphite and activated carbon were tested for their catalytic properties for the oxidation of 4-chlorophenol in aqueous solution with hydrogen peroxide. Batch tests were performed at 30°C, and continuous tests with granular activated carbon under ambient conditions (20°C). Iron powder was shown to act as a catalyst for the activation of hydrogen peroxide and owing

F Lücking; H Köser; M Jank; A Ritter

1998-01-01

168

Free-solution interaction assay of carbonic anhydrase to its inhibitors using back-scattering interferometry.  

PubMed

Back-scattering interferometry (BSI) is a label-free, free-solution, small-volume technique used for characterizing binding interactions, which is also relevant to a growing number of biosensing applications including drug discovery. Here, we use BSI to characterize the interaction of carbonic anhydrase enzyme II with five well-known carbonic anhydrase enzyme II inhibitors (± sulpiride, sulfanilamide, benzene sulfonamide, dansylamide, and acetazolamide) in the presence of DMSO. Dissociation constants calculated for each interaction were consistent with literature values previously obtained using surface plasmon resonance and fluorescence-based competition assays. Results demonstrate the potential of BSI as a drug-screening tool which is fully compatible with DMSO and does not require immobilization or labeling, therefore allowing binding interactions to be characterized in the native state. BSI has the potential for reducing labor costs, sample consumption, and assay time while providing enhanced reliability over existing techniques. PMID:20972990

Morcos, Ereny F; Kussrow, Amanda; Enders, Carolyn; Bornhop, Darryl

2010-11-01

169

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

170

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

NASA Astrophysics Data System (ADS)

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.

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

171

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

172

Corrosion Inhibition of Carbon Steel by New Thiophene Azo Dye Derivatives in Acidic Solution  

NASA Astrophysics Data System (ADS)

Inhibition of carbon steel corrosion in 2 M hydrochloric acid (HCl) solution by thiophene azo dye derivatives were studied using weight loss, electrochemical frequency modulation (EFM), and atomic absorption techniques. The experimental data suggest that the inhibition efficiency increases with increasing inhibitors concentration in presence of 103 ?M potassium iodide (KI). This is due to synergistic effect. Thus, the experimental results suggested that the presence of these anions in the solution stabilized the adsorption of inhibitors molecules on the metal surface and improved the inhibition efficiency. The results of EFM experiments are a spectrum of current response as a function of frequency. The corrosion rate and Tafel parameters can be obtained with measurement by analyzing the harmonic frequencies. The adsorption of the inhibitors on metal surface obeys the Langmuir adsorption isotherm. The surface of metal examined using Fourier transform infrared and ultraviolet spectroscopy. Quantum chemical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed.

El-Haddad, Mahmoud N.; Fouda, A. S.; Mostafa, H. A.

2013-08-01

173

Comparative study on raman and photoluminescence spectra of carbon nanotubes dispersed in different surfactant solutions  

NASA Astrophysics Data System (ADS)

Raman and photoluminescence (PL) spectra of HiPCO and CoMoCat single-walled carbon nanotubes (SWCNTs) dispersed in 1 wt% aqueous surfactant solutions with five different surfactants were studied. The SWCNT suspensions exhibit almost the same Raman spectra, regardless of the surfactant used, but the PL peak positions of all the observed (7,5), (6,5), (8,3), (9,1), and (6,4) SWCNTs show strong surfactant-dependent shifts as large as ˜19 meV, known as solvatochromic shifts. For SWCNTs dispersed in deoxycholate sodium salts and sodium dodecyl sulfate solutions, the amount of the solvatochromic shift decreases as the excitation laser power is increased.

Park, June; Yang, Hojung; Seong, Maeng-Je

2012-04-01

174

Single Wall Carbon Nano Tube Films and Coatings  

Microsoft Academic Search

Purified single wall carbon nano tubes (SWNTs) produced from the high-pressure carbon monoxide (HiPCO) process have been dissolved \\/dispersed in oleum. These solutions \\/dispersions were optically homogeneous and have been used to form stand-alone SWNT films. The washed, dried, and heat-treated films are isotropic. The scanning electron micrographs of the film surface shows that the nanotube ropes (or fibrils) of

T. V. Sreekumar; Satish Kumar; Lars M. Ericson; Richard E. Smalley

2002-01-01

175

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

E-print Network

Engineering Management Field Project Is Integrated Gasification Combined Cycle with Carbon Capture-Storage the Solution for Conventional Coal Power Plants By Manish Kundi Fall Semester, 2011 An EMGT Field Project report... Chairperson ____________________________ Michael Katzman Committee Member ____________________________ John Conard Committee Member Date accepted:____________________________ IS IGCC with CCS the Solution for Conventional Coal Power...

Kundi, Manish

2011-12-16

176

Measuring the grafting density of nanoparticles in solution by analytical ultracentrifugation and total organic carbon analysis.  

PubMed

Many of the solution phase properties of nanoparticles, such as their colloidal stability and hydrodynamic diameter, are governed by the number of stabilizing groups bound to the particle surface (i.e., grafting density). Here, we show how two techniques, analytical ultracentrifugation (AUC) and total organic carbon analysis (TOC), can be applied separately to the measurement of this parameter. AUC directly measures the density of nanoparticle-polymer conjugates while TOC provides the total carbon content of its aqueous dispersions. When these techniques are applied to model gold nanoparticles capped with thiolated poly(ethylene glycol), the measured grafting densities across a range of polymer chain lengths, polymer concentrations, and nanoparticle diameters agree to within 20%. Moreover, the measured grafting densities correlate well with the polymer content determined by thermogravimetric analysis of solid conjugate samples. Using these tools, we examine the particle core diameter, polymer chain length, and polymer solution concentration dependence of nanoparticle grafting densities in a gold nanoparticle-poly(ethylene glycol) conjugate system. PMID:22967239

Benoit, Denise N; Zhu, Huiguang; Lilierose, Michael H; Verm, Raymond A; Ali, Naushaba; Morrison, Adam N; Fortner, John D; Avendano, Carolina; Colvin, Vicki L

2012-11-01

177

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

NASA Astrophysics Data System (ADS)

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

Lu, Chungsying; Su, Fengsheng; Hu, Suhkai

2008-08-01

178

Wash water solids removal system study  

NASA Technical Reports Server (NTRS)

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

1974-01-01

179

21 CFR 133.137 - Washed curd cheese for manufacturing.  

Code of Federal Regulations, 2013 CFR

21 Food and Drugs 2 2013-04-01...Washed curd cheese for manufacturing. 133.137 Section 133.137 Food and Drugs FOOD...SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION...Washed curd cheese for manufacturing. Washed curd...

2013-04-01

180

21 CFR 133.137 - Washed curd cheese for manufacturing.  

Code of Federal Regulations, 2011 CFR

21 Food and Drugs 2 2011-04-01...Washed curd cheese for manufacturing. 133.137 Section 133.137 Food and Drugs FOOD...SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION...Washed curd cheese for manufacturing. Washed curd...

2011-04-01

181

21 CFR 133.137 - Washed curd cheese for manufacturing.  

Code of Federal Regulations, 2012 CFR

21 Food and Drugs 2 2012-04-01...Washed curd cheese for manufacturing. 133.137 Section 133.137 Food and Drugs FOOD...SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION...Washed curd cheese for manufacturing. Washed curd...

2012-04-01

182

21 CFR 133.137 - Washed curd cheese for manufacturing.  

21 Food and Drugs 2 2014-04-01...Washed curd cheese for manufacturing. 133.137 Section 133.137 Food and Drugs FOOD...SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION...Washed curd cheese for manufacturing. Washed curd...

2014-04-01

183

Use of an activated carbon from antibiotic waste for the removal of Hg(II) from aqueous solution.  

PubMed

Porous carbon has been prepared from waste antibiotic material by a chemical activation method using K(2)CO(3) as an activating reagent. Carbon was studied systematically by the adsorption of nitrogen and iodine. It was found that the process parameters such as activation temperature and activation time are crucial for preparing high-quality activated carbon. The proper choice of the preparation conditions allows to produce microporous activated carbon with a micropore volume up to 0.492 cm(3)/g and a BET surface area of 1260 m(2)/g. Adsorption of mercury(II) from an aqueous solution on antibiotic carbon was investigated under the varying conditions of agitation time, metal ion concentration and pH. The adsorption capacity of the carbon is 129 mg/g. PMID:17428604

Budinova, Temenuzhka; Petrov, Nartzislav; Parra, Jose; Baloutzov, Venelin

2008-07-01

184

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

SciTech Connect

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

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

1984-07-01

185

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

PubMed Central

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

Yu, Fei; Ma, Jie; Han, Sheng

2014-01-01

186

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

187

Gas chromatographic evaluation of pesticide residue contents in nectarines after non-toxic washing treatments.  

PubMed

Washing with aqueous solutions of citric acid, ethanol, glycerol, hydrogen peroxide, potassium permanganate, sodium metabisulfite, sodium laurylsulfate (SLS), sodium hypochlorite, and urea is evaluated for pesticide residue reduction in nectarines and compared with simple tap water washing. Residues of pesticides commonly utilized in nectarines (chlorpyrifos, fenarimol, iprodione, malathion, methidathion, myclobutanil, parathion and pirimicarb) are extracted with ethyl acetate and anhydrous sodium sulfate, extract is concentred and analyzed by GC with nitrogen-phosphorus detection. The formation of possible toxic by-products (chlorpyrifos oxon, malaoxon, methidaoxon and paraoxon methyl) is studied by GC-MS. No toxic by-products are identified in the extracts of the washed samples for the washing-time and concentrations studied, but high levels of sodium hypochlorite, hydrogen peroxide and potassium permanganate form oxons from the organophosphorus pesticides. Ethanol, glycerol and SLS solutions removed near the 50% of the pesticide residues. The other solutions were not more effective than tap water washing. The amount of pesticide removed by washings is related to its water solubility and octanol-water partition coefficient. PMID:15508311

Pugliese, P; Moltó, J C; Damiani, P; Marín, R; Cossignani, L; Mañes, J

2004-10-01

188

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

189

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

190

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

191

21 CFR 1250.87 - Wash water.  

...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

192

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

193

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

194

TRUCK WASHING TERMINAL WATER POLLUTION CONTROL  

EPA Science Inventory

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

195

The phase composition of carbonized aluminum hydroxide  

Microsoft Academic Search

1.In the carbonization of aluminate solutions under conditions of pH 10–11.5 and 25–40°C, amorphous aluminum hydroxide precipitates.2.The gelatinous precipitates, which are products of aging of the amorphous aluminum hydroxide during the process of washing, are not any definite crystalline modification of aluminum hydroxide, but occupy an intermediate position between the amorphous and crystalline states. The molecules of aluminum hydroxide form

Ya. R. Katsobashvili; N. S. Kurkova; M. M. Getsiu

1969-01-01

196

Radionuclide content of Las Vegas wash sediments  

SciTech Connect

The Las Vegas Wash is an excavated waterway channel which drains all surface water and effluent discharge from sewage-treatment facilities from the greater Las Vegas Metropolitan Area to Lake Mead. Runoff and erosion processes are expected to transport man-made radioactivity that was deposited over the past several decades in the Las Vegas Valley. Additionally, radionuclides disposed of via the city`s sanitary system are expected to accumulate in the Wash sediments. Fine and coarse sediment samples were collected at 100 m intervals and analyzed to determine the distribution of alpha- and gamma-emitting radionuclides in the lower 5,500 in of the Las Vegas Wash. Results indicate little accumulation of long-lived fission products in upstream Wash sediments. However, trace amounts of fission products measured in downstream sediments suggest the resuspension and transport of radioactive particulate matter within the Wash. Levels of naturally-occurring radionuclides found in Wash sediments were found to be consistent with levels typically found in southeast Nevada soils.

Rudin, M.J.; Meyers, A.M.; Johnson, W.H. [Univ. of Nevada, Las Vegas, NV (United States)

1996-06-01

197

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

PubMed

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

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

2014-02-01

198

Electrosorption of ions from aqueous solutions with carbon nanotubes and nanofibers composite film electrodes  

SciTech Connect

Electrosorption of ions from aqueous solutions with carbon nanotubes and nanofibers (CNTs-CNFs) composite film electrodes has been demonstrated. The large area CNTs-CNFs film was directly grown on Ni plate by low pressure and low temperature thermal chemical vapor deposition. The CNTs-CNFs electrodes have great advantages such as low cost, easy operation, long-term reproducibility, and integrity of monolithic CNTs-CNFs film and current collector. Batch-mode experiments at low voltage (0.4-2 V) were conducted in a continuously recycling system to investigate the electrosorption process. Purification of water with good reproducibility was achieved because of optimal pore size distribution of CNTs-CNFs composite films.

Wang, X. Z.; Li, M. G.; Chen, Y. W.; Cheng, R. M.; Huang, S. M.; Pan, L. K.; Sun, Z. [Nanotech Center, East China Normal University, North Zhongshan Rd. 3663, Shanghai 200062 (China)

2006-07-31

199

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

PubMed Central

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

2012-01-01

200

Electrostatic charge and interactions within carbon-nanotube nematic in electrolyte solution  

NASA Astrophysics Data System (ADS)

The lyotropic transitions from isotropic solution (I) to nematic liquid crystalline phases (N, N') of single-wall carbon nanotubes (SWNT) are guided by the volumetric fraction together with the electrostatic forces. The latter depends on charge transfer between the SWNT and the solvent-electrolyte, and can be studied in approach similar to Derjaguin-Landau-Verwey-Overbeek. A simple kinetic model for a charging mechanism of SWNT is proposed, which allows analytical treatment. We have explored the optimization of control parameters (equilibrium constants, temperature, pH, etc.) of the model to achieve the separation of densely packed SWNT-bundle (N) into array of spaced individual tubules (N'). Our results explain the observation in recent experiments [1] of the dispersion of SWNT in oleum (overconcentrated sulpheric acid) as well as the sudden collapse of such dispersion with small amount of water added. [1] M. Pasquali et al., Macromolecules (in press).

Lee, Choong-Seop; Yakobson, Boris I.

2004-03-01

201

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

202

Effect of carbon nanofiber surface functional groups on oxygen reduction in alkaline solution  

NASA Astrophysics Data System (ADS)

Carbon nanofibers (CNFs) with different content of surface functional groups which are carboxyl groups (CNF-OX), carbonyl groups (CNF-CO) and hydroxyl groups (CNF-OH) and nitrogen-containing groups (CNF-ON) are synthesized, and their electrocatalytic activities toward oxygen reduction reaction (ORR) in alkaline solution are investigated. The result of X-ray photoelectron spectroscopy (XPS) characterization indicates that a higher concentration of carboxyl groups, carbonyl groups and hydroxyl groups are imported onto the CNF-OX, CNF-CO and CNF-OH, respectively. Cyclic voltammetry shows that both the oxygen- and nitrogen-containing groups can improve the electrocatalytic activity of CNFs for ORR. The CNF-ON/GC electrode, which has nitrogen-containing groups, exhibits the highest current density of ORR. Rotating disk electrode (RDE) characterization shows that the oxygen reduction on CNF-ON/GC electrode proceeds almost entirely through the four-electron reduction pathway, the CNF-OX/GC, CNF-CO/GC and CNF-OH/GC electrodes proceed a two-electron reduction pathway at low potentials (-0.2 V to -0.6 V) followed by a gradual four-electron reduction pathway at more negative potentials, while the untreated carbon nanofiber (CNF-P/GC) electrode proceeds predominantly by a two-electron reduction pathway within the whole range of potential studied.

Zhong, Ren-Sheng; Qin, Yuan-Hang; Niu, Dong-Fang; Tian, Jing-Wei; Zhang, Xin-Sheng; Zhou, Xin-Gui; Sun, Shi-Gang; Yuan, Wei-Kang

2013-03-01

203

Ciprofloxacin adsorption from aqueous solution onto chemically prepared carbon from date palm leaflets.  

PubMed

A chemically prepared carbon was synthesized from date palm leaflets via sulphuric acid carbonization at 160 degrees C. Adsorption of ciprofloxacin (CIP) from aqueous solution was investigated in terms of time, pH, concentration, temperature and adsorbent status (wet and dry). The equilibrium time was found to be 48 hr. The adsorption rate was enhanced by raising the temperature for both adsorbents, with adsorption data fitting a pseudo second-order model well. The activation energy, Ea, was found to be 17 kJ/mol, indicating a diffusion-controlled, physical adsorption process. The maximum adsorption was found at initial pH 6. The wet adsorbent showed faster removal with higher uptake than the dry adsorbent, with increased performance as temperature increased (25-45 degrees C). The equilibrium data were found to fit the Langmuir model better than the Freundlich model. The thermodynamic parameters showed that the adsorption process is spontaneous and endothermic. The adsorption mechanism is mainly related to cation exchange and hydrogen bonding. PMID:23520864

El-Shafey, El-Said Ibrahim; Al-Lawati, Haider; Al-Sumri, Asmaa Soliman

2012-01-01

204

Solution and hydrate formation behind a shock wave in liquid with nitrogen — carbon dioxide bubbles in a presence of surfactant  

NASA Astrophysics Data System (ADS)

The processes of solution and hydrate formation behind a shock wave of moderate amplitude were studied experimentally in water with bubbles of nitrogen — carbon dioxide mixture at different initial static pressures in the medium and surfactant concentrations. It is shown that these bubbles do not affect significantly the processes of solution and hydrate formation behind a shock wave during the considered periods. The hypothesis about partial hydration of nitrogen from the gas mixture at intense formation of carbon dioxide hydrate was suggested for the conditions, when the pressure behind the wave is less than the equilibrium pressure of nitrogen hydrate formation at a given temperature.

Dontsov, V. E.

2009-03-01

205

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

206

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

207

Corrosion of used nuclear fuel in aqueous perchlorate and carbonate solutions  

NASA Astrophysics Data System (ADS)

The corrosion of used fuel was investigated using electrodes constructed from fuel pins discharged from the Pickering, Bruce and Darlington CANDU reactors, and compared to the corrosion behaviour observed on unirradiated UO 2 and SIMFUEL. Experiments were carried out in solutions of NaClO 4 (pH˜ 9.5) in the presence and absence of (a) substantial concentrations of sodium carbonate, and (b) additional external gamma fields. Used fuel electrodes reached oxidizing corrosion potentials ( ECORR) rapidly compared with unirradiated UO 2 electrodes. However, optical and SEM examinations showed no evidence for rapid oxidative dissolution. This reaction, expected to be fast since high values of ECORR are observed, appears to be blocked by the accumulation of secondary phases in grain boundaries. The oxidation and dissolution behaviour of used fuel is determined predominantly by (i) the dose rate in solution near the fuel surface, (ii) the extent of burnup (which determines the degree of fission product doping), and (iii) the degree of non-stoichiometry.

Shoesmith, D. W.; Sunder, S.; Bailey, M. G.; Miller, N. H.

1996-01-01

208

Removal of Pb(II) from aqueous solution by oxidized multiwalled carbon nanotubes.  

PubMed

Oxidized multiwalled carbon nanotubes (MWCNTs) were employed as sorbent to study the sorption characteristic of Pb(II) from aqueous solution as a function of contact time, pH, ionic strength, foreign ions, and oxidized MWCNTs' contents under ambient conditions using batch technique. The results indicate that sorption of Pb(II) on oxidized MWCNTs is strongly dependent on pH values, and independent of ionic strength and the type of foreign ions. The removal of Pb(II) to oxidized MWCNTs is rather quickly and the kinetic sorption can be described by a pseudo-second-order model very well. Sorption of Pb(II) is mainly dominated by surface complexation rather than ion exchange. The efficient removal of Pb(II) from aqueous solution is limited at pH 7-10. X-ray photoelectron spectroscopy (XPS) is performed to study the sorption mechanism at a molecular level and thereby to identify the species of the sorption processes. The 3-D relationship of pH, Ceq and q indicates that all the data of Ceq-q lie in a straight line with slope -V/m and intercept C0V/m for the same initial concentration of Pb(II) and same content of oxidized MWCNTs of each experimental data. PMID:18053642

Xu, Di; Tan, Xiaoli; Chen, Changlun; Wang, Xiangke

2008-06-15

209

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

NASA Technical Reports Server (NTRS)

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

Treiman, Allan H.

1995-01-01

210

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

211

Effect of surfactant structure on the stability of carbon nanotubes in aqueous solution.  

PubMed

The suspending behaviors of multiple-wall carbon nanotubes (MWNTs), including pristine MWNTs (p-MWNTs) and acid-mixture-treated MWNTs (MWNTCOOH), stabilized by cationic single-chain surfactant, dodecyltrimethylammonium bromide (DTAB), and cationic gemini surfactant hexyl-alpha,beta-bis(dodecyldimethylammonium bromide) (C 12C 6C 12Br 2) were studied systematically. The surfactant structure influences the suspendability of MWNTs dramatically as well as the surfactant adsorption behavior on the nanotubes. Although both the surfactants can disperse the MWNTs effectively, they actually show different stabilizing ability. DTAB is not capable of stabilizing these two MWNTs below critical micelle concentration (CMC). However, C 12C 6C 12Br 2 can suspend both the nanotubes effectively even well below its CMC. Moreover, the adsorption of these two surfactants reaches equilibrium at twice the CMC with the original MWNT concentration of 2 mg/mL, 2 mM for C 12C 6C 12Br 2, and 30 mM for DTAB. After the adsorption equilibrium, the maximum amounts of the two suspended MWNTs in C 12C 6C 12Br 2 solution are about twice as much as those in DTAB solution. The strong hydrophobic interaction among the C 12C 6C 12Br 2 molecules and between the C 12C 6C 12Br 2 molecules and the nanotubes as well as the high charge capacity of C 12C 6C 12Br 2 lead to its much stronger adsorption ability on the MWNTs and result in its superior stabilizing ability for the MWNTs in aqueous phase. The gemini surfactant provides a possibility to effectively stabilize the MWNTs in aqueous solutions even at very low surfactant concentration well below its CMC. PMID:18491940

Wang, Qi; Han, Yuchun; Wang, Yilin; Qin, Yujun; Guo, Zhi-Xin

2008-06-19

212

Adsorptive removal of Zn(II) ion from aqueous solution using rice husk-based activated carbon  

NASA Astrophysics Data System (ADS)

The study of rice husk-based activated carbon as a potential low-cost adsorbent for the removal of Zn(II) ion from aqueous solution was investigated. Rice husk, an agricultural waste, is a good alternative source for cheap precursor of activated carbon due to its abundance and constant availability. In this work, rice husk-based activated carbon was prepared via chemical treatment using NaOH as an activation agent prior the carbonization process. Three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon carbonized at 650°C, were analyzed for their morphological characteristics using field-emission scanning electron microscope/energy dispersive X-ray (FESEM/EDX). Other analyses were also conducted on these samples using fourier transmitter infrared spectroscopy (FTIR), CHN elemental analyzer and X-ray diffraction (XRD) for characterization study. The porous properties of rice husk-based activated carbon were determined by Brunauer-Emmett-Teller (BET) surface area analyzer, and its surface area and pore volume were found to be 255 m2/g and 0.17 cm2/g, respectively. The adsorption studies for the removal of Zn(II) ion from aqueous solution were carried out as a function of varied contact time at room temperature. The concentration of Zn(II) ion was analyzed using atomic absorption spectrophotometer (AAS). The results obtained from adsorption studies indicate the potential of rice husk as an economically promising precursor for the preparation of activated carbon for removal of Zn(II) ion from aqueous solution.

Taha, Mohd F.; Ibrahim, Muhammad H. C.; Shaharun, Maizatul S.; Chong, F. K.

2012-09-01

213

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

214

Effect of yttrium and chromium ion implantation on crevice electrochemical behavior of carbon steel in sodium chloride solution  

NASA Astrophysics Data System (ADS)

In order to study the effect of yttrium (Y) and chromium (Cr) ion implantation on the crevice corrosion behavior of carbon steel, the carbon steel was implanted with Y and Cr ion using MEVVA source at an energy of 40 keV. Electrochemical measurement was employed to evaluate the crevice corrosion of implanted carbon steel in NaCl solution. The results indicated that, after Y and Cr ion implantation, the carbon steel's crevice corrosion resistance and electrochemical characteristic were significantly improved in NaCl solution when the implantation dose of Y increased. Auger electron spectroscopy (AES) analysis of the implanted carbon steel manifested that the surface layer was mainly composed of elements Fe, Cr, O, and Y. Most of element Y was located near the outside region of the surface layer/solution interface, whereas Cr was enriched in the transition area between surface layer and matrix. By X-ray photoelectron spectroscopy (XPS) analysis, the implanted Y was in the form of Y 2O 3, whereas Cr in the form of Cr 2O 3 in the surface layer. The mechanism of the crevice corrosion resistance and electrochemical characteristic improvement was that, after Y and Cr ion implantation, the surface layer seemed to be constituted by Y 2O 3 and Cr 2O 3. The surface layer acted as a barrier to reduce the metal matrix to contact with the corrosion medium such as inhibiting Cl - ions from corroding the layer.

Liang, Chenghao; Huang, Naibao

2008-12-01

215

POTENTIAL FOR STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS CONTAINING HIGHLY CAUSTIC SOLUTIONS  

Microsoft Academic Search

The evaporator recycle streams of nuclear waste tanks may contain waste in a chemistry and temperature regime that exceeds the current corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history found that two of these A537 carbon steel tanks were operated in highly concentrated hydroxide solution at high

P. Lam; C. Stripling; D. Fisher; J. Elder

2010-01-01

216

Removal of congo red from aqueous solution by bagasse fly ash and activated carbon: Kinetic study and equilibrium isotherm analyses  

Microsoft Academic Search

Present investigation deals with the utilisation of bagasse fly ash (BFA) (generated as a waste material from bagasse fired boilers) and the use of activated carbons—commercial grade (ACC) and laboratory grade (ACL), as adsorbents for the removal of congo red (CR) from aqueous solutions. Batch studies were conducted to evaluate the adsorption capacity of BFA, ACC and ACL and the

Indra Deo Mall; Vimal Chandra Srivastava; Nitin Kumar Agarwal; Indra Mani Mishra

2005-01-01

217

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

218

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

219

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

220

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

221

Effects of activated carbon cloth surface on organic adsorption in aqueous solutions. Use of statistical methods to describe mechanisms  

SciTech Connect

The adsorption of polluted water is performed by activated carbon fibers. Three kinds of material are compared: microporous and mesoporous cloths and microporous granular activated carbon. These porous solids are characterized by scanning electron microscopy and atomic force microscopy. BET surface areas and porous volumes are determined. Adsorption of a large number of organic compounds is carried out in water onto activated carbon cloths and granules. Kinetic and equilibrium data are expressed in terms of initial velocities and classical model parameters (Freundlich). These adsorbability parameters are then discussed according to solute molecular structures and activated carbon characteristic. The results obtained show that fluid-solid transfer is directly related to surface and porous structure (pore size distribution and pore connection with the external surface of adsorbents). The adsorption data of several aromatics and aliphatics onto a microporous activated carbon cloth are discussed statistically. A quantitative structure-property relationship method is used. Multiple linear regression and neural networks enable the assessment of correlations between the Freundlich adsorption parameter (log K) and molecular structure defined by molecular connectivity indexes. The neutral network architecture is optimized, and results determined by the two statistical methods are compared: the neural network approach seems to give better results than multiple linear regression to assess this kind of relationship between adsorption and adsorbate molecular structure, even though its predictive ability is low. From a variable analysis, the results are discussed in terms of adsorbate positions at the adsorbent surface and mechanisms of interaction between solutes and an activated carbon surface are proposed.

Brasquet, C.; Le Cloirec, P.

1999-08-31

222

Removal of naphthalene from recirculated wash oil  

SciTech Connect

A bleed stream from the recirculating wash oil in a final cooling system for coke oven gas is centrifugally separated into a waste water stream, a sludge stream and a clean, dry oil stream which is substantially free of solids and has a water content less than 0.5% (Wt.). The clean, dry oil stream is heated to less than about 160/sup 0/C., preferably 125/sup 0/-135/sup 0/C, before entering a naphthalene stripper-wash oil still.

Burcaw, K.R.; Watkins, R.E.

1981-09-01

223

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

PubMed

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

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

2014-10-01

224

Efficacy of washing with a commercial flatbed brush washer, using conventional and experimental washing agents, in reducing populations of Escherichia coli on artificially inoculated apples.  

PubMed

Conventional and experimental washing formulations were applied with a commercial flatbed brush washer under conditions representative of commercial practice to determine their efficacy in decontaminating apples inoculated with a nonpathogenic Escherichia coli strain. Golden Delicious apples (18 kg) inoculated with E. coli were mixed with approximately 109 kg of uninoculated Fuji apples (distinctly different in appearance) in a wet dump tank containing 1,325 liters of water at 20 degrees C for 15 min. The combined apples were washed in a flatbed brush washer with the following washing solutions: water at 20 degrees C, water at 50 degrees C, 200 ppm of chlorine (pH 6.4) at 20 degrees C, 8% trisodium phosphate at 20 degrees C, 8% trisodium phosphate at 50 degrees C, 5% hydrogen peroxide at 20 degrees C, 5% hydrogen peroxide at 50 degrees C, 1% APL Kleen 245 at 50 degrees C, and two-stage washing treatments using the combination of 1% APL Kleen 245 at 20 or 50 degrees C followed by 5% hydrogen peroxide at 35 or 50 degrees C. None of the washing treatments tested under the conditions of this experiment significantly reduced the E. coli populations on the inoculated apples or in cider made from these apples, probably as a consequence of the inability of this washing system to inactivate or remove the bacterial cells in inaccessible calyx and stem areas of apples. These results are important because they demonstrate the need for new fruit washing technology that can overcome this limitation. Also, there was no significant cross-contamination of the Fuji apples in the dump tank. Significant cross-contamination of cider, made with uninoculated apples, occurred in the hammer mill and/or the press cloth when these units were not sanitized following a trial with inoculated apples. PMID:11271760

Annous, B A; Sapers, G M; Mattrazzo, A M; Riordan, D C

2001-02-01

225

Numerical modeling of carbon dioxide sequestration on the rate of pressure solution creep in limestone: Preliminary results  

E-print Network

When carbon dioxide (CO2) is injected into an aquifer or a depleted geological reservoir, its dissolution into solution results in acidification of the pore waters. As a consequence, the pore waters become more reactive, which leads to enhanced dissolution-precipitation processes and a modification of the mechanical and hydrological properties of the rock. This effect is especially important for limestones given that the solubility and reactivity of carbonates is strongly dependent on pH and the partial pressure of CO2. The main mechanism that couples dissolution, precipitation and rock matrix deformation is commonly referred to as intergranular pressure solution creep (IPS) or pervasive pressure solution creep (PSC). This process involves dissolution at intergranular grain contacts subject to elevated stress, diffusion of dissolved material in an intergranular fluid, and precipitation in pore spaces subject to lower stress. This leads to an overall and pervasive reduction in porosity due to both grain indent...

Renard, Francois; Hellmann, Roland; Collombet, Marielle; Guen, Yvi Le

2008-01-01

226

Hand washing compliance among retail food establishment workers in Minnesota.  

PubMed

Inadequate hand washing by food workers is an important contributing factor to foodborne disease outbreaks in retail food establishments (RFEs). We conducted a survey of RFEs to investigate the effect of hand washing training, availability of hand washing facilities, and the ability of the person in charge (PIC) to describe hand washing according to the Minnesota Food Code (food code) on workers' ability to demonstrate food code-compliant hand washing. Only 52% of the PICs could describe the hand washing procedure outlined in the food code, and only 48% of workers could demonstrate code-compliant hand washing. The most common problems observed were failure to wash for 20 s and failure to use a fingernail brush. There was a strong positive association between the PIC being a certified food manager and being able to describe the food code hand washing procedure (odds ratio [OR], 5.5; 95% confidence interval [CI], 2.2 to 13.7), and there was an even stronger association between the PIC being able to describe hand washing and workers being able to demonstrate code-compliant hand washing (OR, 15; 95% CI, 6 to 37). Significant associations were detected among correct hand washing demonstration, physical infrastructure for hand washing, and the hand washing training methods used by the establishment. However, the principal determinant of successful hand washing demonstration was the PIC's ability to describe proper hand washing procedure. These results suggest that improving hand washing practices among food workers will require interventions that address PIC knowledge of hand washing requirement and procedure and the development and implementation of effective hand washing training methods. PMID:15633696

Allwood, Paul B; Jenkins, Timothy; Paulus, Colleen; Johnson, Lars; Hedberg, Craig W

2004-12-01

227

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

228

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

229

Organic compounds in olive mill wastewater and in solutions resulting from hydrothermal carbonization of the wastewater.  

PubMed

Organic components in olive mill wastewater (OMW) were analyzed by exhaustive solvent extraction of the lyophilisate followed by pre-chromatographic derivatization techniques and GC/MS-analysis of the extracts. Simple biophenols including tyrosol (Tyr), hydroxytyrosol (OH-Tyr) and homovanillic alcohol as well as complex biophenols including decarbomethoxy ligostride aglycon and decarbomethoxy oleuropein aglycon proved most abundant analytes. Hydroxylated benzoic and cinnamic acids are less abundant, which may indicate a humification process to have occurred. The pattern of organic components obtained from native OMW was compared with that obtained from hydrothermal carbonization (HTC) of the waste product. Former results provided strong evidence that HTC of OMW at 220°C for 14h results in an almost complete hydrolysis of complex aglycons. However, simple biophenols were not decomposed on hydrothermal treatment any further. Phenol and benzenediols as well as low molecular weight organic acids proved most abundant analytes which were generated due to HTC. Similarly to aglycons, lipids including most abundant acylglycerines and less abundant wax esters were subjected almost quantitatively to hydrolysis under hydrothermal conditions. Fatty acids (FAs) released from lipids were further decomposed. The pathways of volatile analytes in both native OMW and aqueous HTC solutions were studied by solventless headspace-Solid Phase Micro Extraction. Basically, a wide array low molecular alcohols and ketones occurring in native OMW survived the HTC process. PMID:23648325

Poerschmann, J; Weiner, B; Baskyr, I

2013-09-01

230

Adsorption kinetics of phenol and 3-nitrophenol from aqueous solutions on conventional and novel carbons.  

PubMed

Carbonaceous adsorbents prepared from olive stones biomass and novolac resin, as well as a commercial activated carbon for comparison reasons, have been examined for the removal of phenol and 3-nitrophenol from aqueous solutions. All carbonaceous adsorbents have been characterized by SEM-EDAX analysis and mercury porosimetry. The experimental data were examined according to the following kinetic models: pseudo first order, pseudo second order, Natarajan and Khalaf, Elovich, power function equations and intraparticle diffusion. By plotting the amount of adsorbate (phenol or 3-nitrophenol) adsorbed per unit mass of adsorbent b(t), versus the square root of time, four regions can be distinguished (A, B, C and D). By applying all the previously described models it is concluded that: (a) the intraparticle diffusion model is valid for the B and C region, whereas macropore diffusion and mesopore diffusion, respectively, take place. The pore diffusion coefficient, D for each carbonaceous material was calculated and indicated that the adsorption is controlled by diffusion, (b) the power model for the adsorption of phenol on each of the three carbonaceous materials is acceptable only for the C region and (c) the pseudo second order for the adsorption of 3-nitrophenol on each of the three carbonaceous materials is acceptable for the C region. PMID:19625123

Ioannou, Z; Simitzis, J

2009-11-15

231

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

232

Removal of boron from aqueous solution using magnetic carbon nanotube improved with tartaric acid  

PubMed Central

Boron removal capacity of multi-walled carbon nanotubes (MWCNTs) modified with tartaric acid was investigated in this study. Modification of MWCNTs with tartaric acid was confirmed by Boehm surface chemistry method and fourier transform infra-red (FT-IR) spectroscopy. Experiments were performed to determine the adsorption isotherm and adsorption thermodynamic parameters of boron adsorption on tartaric acid modified MWCNTs (TA-MWCNTs). The effect of variables including initial pH, dosage of adsorbent, contact time and temperature was investigated. Analysis of data showed that adsorption equilibrium could be better described by Freundlich isotherm and the maximum adsorption capacities obtained at the pH of 6.0 was 1.97 mg/g. The estimated thermodynamic values of free energy (?G°), entropy (?S°) and enthalpy (?H°) indicated a spontaneous and an endothermic process. Furthermore, the TA-MWCNTs was magnetized for separation of boron-contaminated adsorbent from aqueous solution by applying magnetic field. The results showed that magnetic TA-MWCNTs particles were separated effectively after adsorption from contaminated water. PMID:24393401

2014-01-01

233

Washing of the AW-101 entrained solids  

SciTech Connect

BNFL Inc. (BNFL) is under contract with the US Department of Energy, River Protection Project (DOE-RPP) to design, construct, and operate facilities for treating wastes stored in the single-shell and double-shell tanks at the Hanford Site, Richland, Washington. The DOE-BNFL RPP contract identifies two feeds to the waste treatment plant: (1) primarily liquid low-activity waste (LAW) consisting of less than 2 wt% entrained solids and (2) high-level waste (HLW) consisting of 10 to 200 g/L solids slurry. 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 AW-101 low-activity waste (LAW) sample. The objective of this work was to gather data on the solubility of the AW-101 entrained solids in 0.01 M NaOH, so that BNFL can evaluate whether these solids require caustic leaching. The work was conducted according to test plan BNFL-TP-29953-9, Rev. 0, LAW Entrained Solids Water Wash and Caustic Leach Testing. The test went according to plan, with no deviations from the test plan. Based on the results of the 0.01 M NaOH washing, a decision was made by BNFL to not proceed with the caustic leaching test. The composition of the washed solids was such that caustic leaching would not result in significant reduction in the immobilized HLW volume.

GJ Lumetta

2000-03-31

234

Rain Induced Pollutant Washing in Urban Areas  

Microsoft Academic Search

One of the major problems in urban areas is the pollution of atmosphere, soil and water. The rain washes and cleanses the air and the land surface and then, as runoff, transports a variety of materials to the nearest receiving water body. The pollution generation in storm runoff is a very complex process. It is an accepted view that a

G. Del Giudice; A. Leopardi; M. Greco

235

Bicilavadora The Pedal-Powered Washing Machine  

E-print Network

chores are often seen as cul- tural obligations for women so little effort is expended to diminish them, washing laundry is a difficult, time-consuming task that falls solely on women. Mothers and daughters 2005 Proposal 1 Background 1.1 Need In developing countries, rural women are among the least privileged

Gummadi, Ramakrishna

236

Recycled Wash Water Crushed Returned Concrete  

E-print Network

.ORG 4000 4500 5000 Control 4h 1d 7d Age of Slurry 28-dCompressiveS Reclaimers w/Gray Water Recycling WWW. NRMCA.ORG Gray Water Recycling Monitoring gray water Specific gravity Temperature Age Plumbing back1 Recycled Wash Water Crushed Returned Concrete National Concrete Consortium March 2012 Colin Lobo

237

Wash your hands. water and soap.  

E-print Network

STEP 1 Wash your hands. · Use warm water and soap. · Scrub hands and fingernails for at least 20 seconds. · Dry hands with a clean cloth or paper towel. STEP 2 Make sure bottles and nipples are clean should be lukewarm. · Place some drops of formula on the back of the hand to check the temperature

238

What Happens at a Car Wash?  

ERIC Educational Resources Information Center

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

Gallick, Barbara; Lee, Lisa

2010-01-01

239

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

PubMed

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

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

2011-11-01

240

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

241

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

242

Carbon capture and storage in the U.S. : a sinking climate solution  

E-print Network

Coal-fired power plants produce half of the United States' electricity and are also the country's largest emitter of carbon dioxide, the greenhouse gas responsible for climate change. Carbon Capture and Storage (CCS) is a ...

Henschel, Rachel Hockfield

2009-01-01

243

The behavior of silver nanotextiles during washing.  

PubMed

The widespread use of silver nanoparticles (Ag-NPs) in commercial products, especially textiles, will likely result in an unknown spread of Ag into the environment. The quantification and characterization of the Ag released from nano-Ag-products is an important parameter needed to predict the effect of Ag-NPs on the environment. The aim of this study was to determine the amount and the form of Ag released during washing from nine fabrics with different ways of silver incorporation into or onto the fibers. The effect of pH, surfactants, and oxidizing agents was evaluated. The results show that little dissolution of Ag-NPs occurs under conditions relevant to washing (pH 10) with dissolved concentrations 10 times lower than at pH 7. However, bleaching agents such as hydrogen peroxide or peracetic acid (formed by the perborate/TAED system) can greatly accelerate the dissolution of Ag. The amount and form of Ag released from the fabrics as ionic and particulate Ag depended on the type of Ag-incorporation into the textile. The percentage of the total silver emitted during one washing of the textiles varied considerably among products (from less than 1 to 45%). In the washing machine the majority of the Ag (at least 50% but mostly >75%) was released in the size fraction >450 nm, indicating the dominant role of mechanical stress. A conventional silver textile did not show any significant difference in the size distribution of the released silver compared to many of the textiles containing nano-Ag. These results have important implications for the risk assessment of Ag-textiles and also for environmental fate studies of nano-Ag, because they show that under conditions relevant to washing, primarily coarse Ag-containing particles are released. PMID:19924931

Geranio, L; Heuberger, M; Nowack, B

2009-11-01

244

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

245

Errors During Intraoperative Cell Salvage Because of Inappropriate Wash Solutions  

Microsoft Academic Search

nterest in blood conservation techniques is growing in the United States. This interest stems from a shortage of blood components available for trans- fusion (1). Likewise, a growing awareness of errors in medicine has attracted attention because of a recent In- stitute of Medicine (IOM) report on errors (2). This IOM report documents that from 44,000 to 98,000 deaths a

Jonathan H. Waters; Juraj Sprung

2001-01-01

246

Molecular-scale Hydrophilicity Induced by Solute: Molecular-thick Charged Pancakes of Aqueous Salt Solution on Hydrophobic Carbon-based Surfaces  

NASA Astrophysics Data System (ADS)

We directly observed molecular-thick aqueous salt-solution pancakes on a hydrophobic graphite surface under ambient conditions employing atomic force microscopy. This observation indicates the unexpected molecular-scale hydrophilicity of the salt solution on graphite surfaces, which is different from the macroscopic wetting property of a droplet standing on the graphite surface. Interestingly, the pancakes spontaneously displayed strong positively charged behavior. Theoretical studies showed that the formation of such positively charged pancakes is attributed to cation-? interactions between Na+ ions in the aqueous solution and aromatic rings on the graphite surface, promoting the adsorption of water molecules together with cations onto the graphite surface; i.e., Na+ ions as a medium adsorbed to the graphite surface through cation-? interactions on one side while at the same time bonding to water molecules through hydration interaction on the other side at a molecular scale. These findings suggest that actual interactions regarding carbon-based graphitic surfaces including those of graphene, carbon nanotubes, and biochar may be significantly different from existing theory and they provide new insight into the control of surface wettability, interactions and related physical, chemical and biological processes.

Shi, Guosheng; Shen, Yue; Liu, Jian; Wang, Chunlei; Wang, Ying; Song, Bo; Hu, Jun; Fang, Haiping

2014-10-01

247

Molecular-scale Hydrophilicity Induced by Solute: Molecular-thick Charged Pancakes of Aqueous Salt Solution on Hydrophobic Carbon-based Surfaces.  

PubMed

We directly observed molecular-thick aqueous salt-solution pancakes on a hydrophobic graphite surface under ambient conditions employing atomic force microscopy. This observation indicates the unexpected molecular-scale hydrophilicity of the salt solution on graphite surfaces, which is different from the macroscopic wetting property of a droplet standing on the graphite surface. Interestingly, the pancakes spontaneously displayed strong positively charged behavior. Theoretical studies showed that the formation of such positively charged pancakes is attributed to cation-? interactions between Na(+) ions in the aqueous solution and aromatic rings on the graphite surface, promoting the adsorption of water molecules together with cations onto the graphite surface; i.e., Na(+) ions as a medium adsorbed to the graphite surface through cation-? interactions on one side while at the same time bonding to water molecules through hydration interaction on the other side at a molecular scale. These findings suggest that actual interactions regarding carbon-based graphitic surfaces including those of graphene, carbon nanotubes, and biochar may be significantly different from existing theory and they provide new insight into the control of surface wettability, interactions and related physical, chemical and biological processes. PMID:25348642

Shi, Guosheng; Shen, Yue; Liu, Jian; Wang, Chunlei; Wang, Ying; Song, Bo; Hu, Jun; Fang, Haiping

2014-01-01

248

Molecular-Scale Hydrophilicity Induced by Solute: Molecular-thick Charged Pancakes of Aqueous Salt Solution on Hydrophobic Carbon-based Surfaces  

E-print Network

We directly observed molecular-thick aqueous salt-solution pancakes on a hydrophobic graphite surface under ambient conditions employing atomic force microscopy. This observation indicates the unexpected molecular-scale hydrophilicity of the salt solution on graphite surfaces, which is different from the macroscopic wetting property of a droplet standing on the graphite surface. Interestingly, the pancakes spontaneously displayed strong positively charged behavior. Theoretical studies showed that the formation of such positively charged pancakes is attributed to cation-{\\pi} interactions between Na+ ions in the aqueous solution and aromatic rings on the graphite surface, promoting the adsorption of water molecules together with cations onto the graphite surface; i.e., Na+ ions as a medium adsorbed to the graphite surface through cation-{\\pi} interactions on one side while at the same time bonding to water molecules through hydration interaction on the other side at a molecular scale. These findings suggest that actual interactions regarding carbon-based graphitic surfaces including those of graphene, carbon nanotubes, and biochar may be significantly different from existing theory and they provide new insight into the control of surface wettability, interactions and related physical, chemical and biological processes.

Guosheng Shi; Yue Shen; Jian Liu; Chunlei Wang; Ying Wang; Bo Song; Jun Hu; Haiping Fang

2014-09-16

249

Molecular-scale Hydrophilicity Induced by Solute: Molecular-thick Charged Pancakes of Aqueous Salt Solution on Hydrophobic Carbon-based Surfaces  

PubMed Central

We directly observed molecular-thick aqueous salt-solution pancakes on a hydrophobic graphite surface under ambient conditions employing atomic force microscopy. This observation indicates the unexpected molecular-scale hydrophilicity of the salt solution on graphite surfaces, which is different from the macroscopic wetting property of a droplet standing on the graphite surface. Interestingly, the pancakes spontaneously displayed strong positively charged behavior. Theoretical studies showed that the formation of such positively charged pancakes is attributed to cation–? interactions between Na+ ions in the aqueous solution and aromatic rings on the graphite surface, promoting the adsorption of water molecules together with cations onto the graphite surface; i.e., Na+ ions as a medium adsorbed to the graphite surface through cation–? interactions on one side while at the same time bonding to water molecules through hydration interaction on the other side at a molecular scale. These findings suggest that actual interactions regarding carbon-based graphitic surfaces including those of graphene, carbon nanotubes, and biochar may be significantly different from existing theory and they provide new insight into the control of surface wettability, interactions and related physical, chemical and biological processes. PMID:25348642

Shi, Guosheng; Shen, Yue; Liu, Jian; Wang, Chunlei; Wang, Ying; Song, Bo; Hu, Jun; Fang, Haiping

2014-01-01

250

Equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride  

SciTech Connect

Natural gas components such as hydrogen sulfide, carbon dioxide, and ethane form gas hydrates of structure I under suitable temperature and pressure conditions. Information on such conditions is vital to the oil and gas industry in order to design and operate processing equipment and pipelines so that hydrate formation is avoided. Incipient equilibrium hydrate formation conditions for hydrogen sulfide, carbon dioxide, and ethane in aqueous solutions of ethylene glycol and sodium chloride were experimentally obtained in the temperature range 264--290 K and the pressure range 0.23--3.18 MPa. A variable-volume sapphire cell was used for the measurements.

Majumdar, A.; Mahmoodaghdam, E.; Bishnoi, P.R.

2000-02-01

251

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

252

Structural properties of ZnO nanowires directly grown on a carbon film in ZnCl2 aqueous solution  

NASA Astrophysics Data System (ADS)

We have investigated the nucleation and growth of single crystal ZnO nanowires on carbon films. ZnO nanostructures were grown on a transmission electron microscopy (TEM) grid consisting of a carbon film supported by a copper frame. No seed layer was used to provide nucleation sites. The resulting ZnO nanowires showed different diameters and lengths for growth on metal versus the carbon film. This is indicative of differences in nucleation and growth processes that depend on the substrate that was used. Our results indicate that ZnO nanowire arrays can be grown on carbon films by using a ZnCl2 growth solution. This is a simple and low-cost method for growth of the nanowires. The method can also be used for investigating the mechanisms and morphology of ZnO growth on such carbon-based substrates. The growth of ZnO nanowires on carbon films, ribbons or nanodots has potential application for use in sensors, electronic, optoelectronic and photovoltaic devices.

Choi, Hyung Woo; Theodore, N. David; Das, Sayantan; Dhar, Aritra; Alford, T. L.

2014-11-01

253

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

PubMed Central

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

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

2013-01-01

254

Potential Use of Hyperoxygenated Solution as a Treatment Strategy for Carbon Monoxide Poisoning  

PubMed Central

Aim Carbon monoxide (CO) poisoning can cause permanent damage in tissues that are sensitive to hypoxia. We explored the feasibility and efficacy of using a hyperoxygenated solution (HOS) to treat severe acute CO poisoning in an animal model. Methods Male Sprague-Dawley rats were subjected to CO poisoning. The HOS was administered into the femoral vein of these rats through a catheter (10 ml/kg). Carboxyhemoglobin (COHb) and blood gases were used to assess the early damage caused by CO poisoning. S100? was measured to predict the development of late cognitive sequelae of CO. The Morris water maze test was performed to assess cognitive function, and Nissl staining was performed to observe histologic change. Results The COHb concentrations rapidly decreased at 5 min after the HOS administration; however, the PaO2 and SaO2 in rats treated with HOS increased significantly 5 min after the HOS administration. The S100? concentrations, which increased significantly after CO poisoning, increased at a much slower rate in the rats treated with HOS (HOS group) compared with the rats treated with O2 inhalation (O2 group). The escape latency in the place navigation test was shortened after CO poisoning on days 11-15 and days 26-30, and the swimming time in quadrant 4 in the spatial probe test on days 15 and 30 after CO poisoning was prolonged in the rats treated with HOS injection compared with the rats treated with oxygen inhalation or normal saline injection. The neuronal degeneration in the HOS group was alleviated than that in the CO or O2 group. Conclusion HOS efficiently alleviates the brain damage in acute CO-poisoned rats and thus may serve as a new way to treat human patients with CO poisoning in clinical practice. PMID:24312588

Meng, Xiangzhong; Qi, Jian; Cui, Yuanyuan; Li, Yunqing; Zhang, Hui; Xu, Lixian

2013-01-01

255

High-capacity adsorption of Cr(VI) from aqueous solution using a hierarchical porous carbon obtained from pig bone.  

PubMed

A hierarchical porous carbon obtained from pig bone (HPC) was utilized as the adsorbent for removal of Cr(VI) from aqueous solution. The effects of solution pH value, concentration of Cr(VI), and adsorption temperature on the removal of Cr(VI) were investigated. The experimental data of the HPC fitted well with the Langmuir isotherm and its adsorption kinetic followed pseudo-second order model. Compared with a commercial activated carbon adsorbent (Norit CGP), the HPC showed an high adsorption capability for Cr(VI). The maximum Cr(VI) adsorption capacity of the HPC was 398.40 mg/g at pH 2. It is found that a part of the Cr(VI) was reduced to Cr(III) on the adsorbent surface from desorption experiment data. The regeneration showed adsorption capacity of the HPC can still achieve 92.70 mg/g even after fifth adsorption cycle. PMID:23489566

Wei, Shaochen; Li, Dongtian; Huang, Zhe; Huang, Yaqin; Wang, Feng

2013-04-01

256

Coagulation of chitin and cellulose from 1-ethyl-3-methylimidazolium acetate ionic-liquid solutions using carbon dioxide.  

PubMed

Chemisorption of carbon dioxide by 1-ethyl-3-methylimidazolium acetate ([C2 mim][OAc]) provides a route to coagulate chitin and cellulose from [C2 mim][OAc] solutions without the use of high-boiling antisolvents (e.g., water or ethanol). The use of CO2 chemisorption as an alternative coagulating process has the potential to provide an economical and energy-efficient method for recycling the ionic liquid. PMID:24115399

Barber, Patrick S; Griggs, Chris S; Gurau, Gabriela; Liu, Zhen; Li, Shan; Li, Zengxi; Lu, Xingmei; Zhang, Suojiang; Rogers, Robin D

2013-11-18

257

Preparation and characterization of nanocomposite, silica aerogel, activated carbon and its adsorption properties for Cd (II) ions from aqueous solution  

Microsoft Academic Search

A novel composite adsorbent, silica aerogel activated carbon was synthesized by sol-gel process at ambient pressure drying method. The composite was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Nitrogen adsorption\\/desorption isotherms (BET).In the present study, the mentioned adsorbent was used moderately for the removal of cadmium ions from aqueous solutions and

M. H. Givianrad; M. Rabani; M. Saber-Tehrani; P. Aberoomand-Azar; M. Hosseini Sabzevari

258

Statistical analysis of a corrosion inhibitor family on three steel surfaces (duplex, super-13 and carbon) in hydrochloric acid solutions  

Microsoft Academic Search

Previous studies have addressed the experimental and theoretical investigation of the inhibition corrosion efficiencies (ICE) of single metal surfaces. Along this line we carried out calculations concerning to 23 compounds on three different single-steel surfaces, duplex, super-13 and the carbon steel in hydrochloric acid (15% w\\/v) solutions. The overall experiment is composed of 69 results of weight loss ICEs at

Ana Luísa de Queiroz Baddini; Sheila Pressentin Cardoso; Eduardo Hollauer; José Antonio da Cunha Ponciano Gomes

2007-01-01

259

The use of rare earth cations as corrosion inhibitors for carbon steel in aerated NaCl solution  

Microsoft Academic Search

Purpose – Application of rare earth (RE) salts as a corrosion inhibitor was first proposed by Goldie and McCarrol in 1984. They showed that, with the addition of 0.001 M of Ce(NO3) or La(NO3) to 3.5% NaCl solution, the inhibition efficiencies were 91 and 82% for carbon steel, respectively. The aim of this paper is to study the inhibition of

A. Amadeh; S. R. Allahkaram; S. R. Hosseini; H. Moradi; A. Abdolhosseini

2008-01-01

260

Radionuclide content of Las Vegas wash sediments  

Microsoft Academic Search

The Las Vegas Wash is an excavated waterway channel which drains all surface water and effluent discharge from sewage-treatment facilities from the greater Las Vegas Metropolitan Area to Lake Mead. Runoff and erosion processes are expected to transport man-made radioactivity that was deposited over the past several decades in the Las Vegas Valley. Additionally, radionuclides disposed of via the city`s

M. J. Rudin; A. M. Meyers; W. H. Johnson

1996-01-01

261

49 CFR 393.78 - Windshield wiping and washing systems.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Windshield wiping and washing systems. 393.78 Section 393.78 Transportation Other Regulations Relating to...SAFE OPERATION Miscellaneous Parts and Accessories § 393.78 Windshield wiping and washing systems....

2010-10-01

262

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

263

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

264

30 CFR 1206.459 - Allocation of washed coal.  

...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

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 1206.260 - 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

267

30 CFR 1206.260 - Allocation of washed coal.  

...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

268

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

269

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

270

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

271

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

272

Nitrogen and Phosphorus Hydrochemistry in Las Vegas Wash.  

National Technical Information Service (NTIS)

The sources of nitrogen and phosphorus nutrient species, the chemical reactions occurring, and the parameters of nutrient uptake were studied for the Las Vegas Wash hydrologic system. Las Vegas Wash, a natural drainage channel running from Las Vegas Valle...

A. Schmidt, J. W. Hess

1980-01-01

273

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

274

30 CFR 206.458 - Determination of washing allowances.  

Code of Federal Regulations, 2010 CFR

...estimates of the allowable coal washing costs for the applicable...recently available operations data for the plant, or if such data are not available, the lessee...estimates based upon industry data for similar coal wash plants. (v)...

2010-07-01

275

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 ...

276

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

277

Carbon nanotubes and graphene in aqueous surfactant solutions : molecular simulations and theoretical modeling  

E-print Network

This thesis describes combined molecular simulations and theoretical modeling studies, supported by experimental observations, on properties and applications of carbon nanotubes (CNTs) and graphene sheets dispersed in ...

Lin, Shangchao

2012-01-01

278

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

279

30 CFR 206.259 - Determination of washing allowances.  

Code of Federal Regulations, 2010 CFR

...estimates of the allowable coal washing costs for the...recently available operations data for the washing system...lessee shall submit all data used to prepare the allowance deduction. The data shall be provided within... (1) If the actual coal washing allowance...

2010-07-01

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

Are carbon nanotubes a natural solution? Applications in biology and medicine.  

PubMed

Carbon nanotubes and materials based on carbon nanotubes have many perceived applications in the field of biomedicine. Several highly promising examples have been highlighted in the literature, ranging from their use as growth substrates or tissue scaffolds to acting as intracellular transporters for various therapeutic and diagnostic agents. In addition, carbon nanotubes have a strong optical absorption in the near-infrared region (in which tissue is transparent), which enables their use for biological imaging applications and photothermal ablation of tumors. Although these advances are potentially game-changing, excitement must be tempered somewhat as several bottlenecks exist. Carbon nanotube-based technologies ultimately have to compete with and out-perform existing technologies in terms of performance and price. Moreover, issues have been highlighted relating to toxicity, which presents an obstacle for the transition from preclinical to clinical use. Although many studies have suggested that well-functionalized carbon nanotubes appear to be safe to the treated animals, mainly rodents, long-term toxicity issues remains to be elucidated. In this report, we systematically highlight some of the most promising biomedical application areas of carbon nanotubes and review the interaction of carbon nanotubes with cultured cells and living organisms with a particular focus on in vivo biodistribution and potential adverse health effects. To conclude, future challenges and prospects of carbon nanotubes for biomedical applications will be addressed. PMID:23427832

Heister, Elena; Brunner, Eric W; Dieckmann, Gregg R; Jurewicz, Izabela; Dalton, Alan B

2013-03-01

282

Evaluation of carbons derived from Gingelly oil cake for the removal of lead(II) from aqueous solutions.  

PubMed

The adsorption of lead(II) onto activated carbons prepared from Gingelly Oil Cake (GOC) by using thermal, sulphuric and zinc chloride activations was investigated. The effects of experimental parameters such as pH, initial concentration, contact time and adsorbents dosage on the lead(II) removal were studied. The data were fitted with Langmuir, Freundlich and Temkin models to describe the equilibrium isotherms. The kinetic data fitted well with Lagergren pseudo first order and pseudo second order models. The maximum adsorption capacity for lead(II) on adsorbents calculated from Langmuir isotherm was found to be 105.26 mg/g and 114.94 mg/g for thermally activated and sulphuric acid activated carbons respectively. R2 values show that Langmuir model fits best to sulphuric acid activated carbon and Freundlich model fits best to thermally activated and zinc chloride activated carbons. The kinetic rates were best fitted to pseudo second order model. FT-IR analysis was used to obtain information on the nature of possible interaction between adsorbents and metal ions. SEM images confirmed the adsorption of lead(II) onto GOC adsorbents through morphological observations. Thermodynamic study showed the feasibility of process and spontaneous nature of the adsorption. The adsorbents were also tested for the removal of lead(II) from lead battery synthetic wastewater. The results indicate that carbons derived from GOC could be used to effectively adsorb lead(II) from aqueous solutions and wastewaters. PMID:22312806

Nagashanmugam, K B; Srinivasan, K

2010-10-01

283

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

284

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

Microsoft Academic Search

We conducted a pot experiment to evaluate the effect of soil washing with CaCl2 on Cd absorption by two soybean cultivars. The results were as follows: (1) Soybean growth was not significantly different in washed and unwashed soils, but the seed Cd concentration for both cultivars decreased significantly, up to 25%, in the washed soils compared with the unwashed soils.

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

2007-01-01

285

Adsorption of pharmaceutical compounds and an endocrine disruptor from aqueous solutions by carbon materials.  

PubMed

Adsorption has been used to study the removal of atenolol, caffeine, diclofenac and isoproturon, pharmaceutical compounds as emerging contaminants and an endocrine disruptor from ultrapure water and a municipal wastewater treatment plant effluent with three carbonaceous materials: activated carbon, multiwalled carbon nanotubes and carbon nanofibers. The adsorption capacities were studied in the temperature range of 25-65°C and pH range from 3 to 9. Several model isotherms were used to model the adsorption equilibrium data. Also, the competitive adsorption was evaluated. PMID:22560026

Sotelo, José L; Rodríguez, Araceli R; Mateos, María M; Hernández, Sergio D; Torrellas, Silvia A; Rodríguez, Juan G

2012-01-01

286

Filtration, Washing, and Caustic Leaching of Hanford Tank AZ-101 Sludge  

SciTech Connect

The world’s largest vitrification facility is being designed and constructed at the U.S. Department of Energy’s Hanford Site, near Richland, Washington to convert radioactive waste stored in underground tanks into glass. Flow sheets call for washing and caustic leaching to pretreat the Hanford Envelope D sludge before it undergoes high-level waste (HLW) vitrification. These pretreatment steps reduce the quantity of HLW generated, by removing components that are soluble in water or caustic solutions, and often limit the waste loading in the glass. Crossflow filtration is specified to separate the wash and leach solutions from the solids. In crossflow filtration, the majority of the filter cake is swept away by the fluid flowing across it. Approximately 4313 g of slurry from Hanford Tank AZ-101 were evaluated by the pretreatment processes of crossflow filtration, washing, caustic leaching, and rinsing. The filterability was measured with a 0.1-mm sintered metal filter using a single-element, crossflow filtration system. Permeate flux of the as-received and washed slurries decayed linearly with the log of the undissolved solids concentration. The permeate flux of these slurries was also shown to be inversely proportional to the permeate viscosity. Statistical analysis indicated that the permeate flux of an 8-wt% insoluble solids slurry was also dependent on transmembrane pressure. As the slurry was concentrated to 18-wt%, the flux was dependent on axial velocity, with little dependency on transmembrane pressure. Samples of permeate from each wash were analyzed for chemical and radiochemical constituents. Primary component removal during the washing and leaching steps are discussed. This work provides important confirmation that the pretreatment of Hanford Envelope D wastes will have acceptable filterability and component removal during the pretreatment steps specified.

Geeting, John GH; Hallen, Richard T.

2005-02-15

287

Spray washing of tomatoes with chlorine dioxide to minimize Salmonella on inoculated fruit surfaces and cross-contamination from revolving brushes.  

PubMed

Chlorine dioxide (ClO(2)) is an antimicrobial agent available for commercial produce washing. This study examined the efficacy of ClO(2) at 5 parts per million (ppm) during spray washing of tomatoes (5.0 ml/s per fruit) for preventing Salmonella enterica transfer from inoculated roller brushes to fruit and wash runoff. Furthermore, the sanitizing effects of ClO(2) during spray washing at low and high flow rates (5.0 and 9.3 ml/s per fruit, respectively) on tomato surfaces (nonstem scar areas) with either newly introduced (wet) or overnight air-dried Salmonella inocula were investigated. Salmonella transfer from contaminated brushes to fruit surfaces was reduced 2.1 +/- 0.6 or 4.7 +/- 0.2 log cycles after spray washing with water for 40 s or with the ClO(2) solution for 10 s, respectively. Cross-contamination of Salmonella from brushes to wash runoff during fruit washing for 60 s decreased 5.9 +/- 0.3 log cycles when ClO(2) was used. Fruit washing using contaminated brushes and low flow-rate washing with either water or ClO(2) solution for 10 s reduced newly introduced Salmonella on fruit surfaces by 1.7 +/- 0.6 or 5.1 +/- 0.3 log cycles, respectively. For fruit surfaces with air-dried inocula, washing with water and using uncontaminated brushes for 10 to 40 s reduced Salmonella by 3.2 +/- 0.3 to 3.4 +/- 0.4 log cycles; and the reduction was significantly improved by using ClO(2), high flow rate, or a longer washing time. Washing with ClO(2) at tested flow rates for 10 to 60 s resulted in a 4.4 +/- 0.6 to 5.2 +/- 0.1 log reduction of air-dried Salmonella on fruit surfaces. PMID:20003724

Pao, Steven; Kelsey, D Frank; Long, Wilbert

2009-12-01

288

Metal-doped carbon aerogels as catalysts during ozonation processes in aqueous solutions  

Microsoft Academic Search

The efficiency of Co(II)-, Mn(II)-, and Ti(IV)-doped carbon aerogels for the transformation of ozone into OH radicals was investigated. The carbon aerogels had a markedly acid surface character (pHPZC?3–4) with very high surface oxygen concentrations (O?20%). X-ray photoelectron spectroscopy (XPS) analyses of the samples showed the oxidation state of the metals was +2 for Co and Mn and +4 for

M. Sánchez-Polo; J. Rivera-Utrilla; U. von Gunten

2006-01-01

289

Effect of ammonium-salt solutions on the surface properties of carbon fibers in electrochemical anodic oxidation  

NASA Astrophysics Data System (ADS)

The surfaces of polyacrylonitrile-based carbon fibers were treated by an electrochemical anodic method. Three different kinds of ammonium-salt solutions namely NH4HCO3, (NH4)2CO3 and (NH4)3PO4 were respectively chosen as the electrolytes. The effect of these electrolytes on the surface structure was studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The results showed that longitudinal grooves on the fiber surface became more well-defined and much deeper after surface treatment, and the root mean square roughness (RMS) of carbon fiber surface increased from 4.6 nm for untreated fibers to 13.5 nm for treated fibers in (NH4)3PO4 electrolytes. The concentration of oxygen and nitrogen atomic on the fiber surface increased after surface treatment. The tensile strength of oxidized fibers had an obvious decrease, whereas the interlaminar shear strength (ILSS) value of corresponding carbon fiber reinforced polymers (CFRPs) increased in a large extent. The intensity of oxidative reaction varied with the change of ammonium-salt solutions and electrochemical oxidation in (NH4)3PO4 electrolyte was of the most violence. The corresponding mechanism was also discussed and the result showed that the higher the concentration of OH- ions in the electrolytes, the violent the oxidative reaction happened.

Qian, Xin; Wang, Xuefei; Ouyang, Qin; Chen, Yousi; Yan, Qing

2012-10-01

290

Removal of copper and cadmium from the aqueous solutions by activated carbon derived from Ceiba pentandra hulls.  

PubMed

Activated carbon prepared from Ceiba pentandra hulls, an agricultural solid waste by-product, for the removal of copper and cadmium from aqueous solutions has been studied. Parameters such as equilibrium time, effect of pH and adsorbent dose on removal were studied. The adsorbent exhibited good sorption potential for copper and cadmium at pH 6.0. C=O and S=O functional groups present on the carbon surface were the adsorption sites to remove metal ions from solution. The experimental data was analysed by both Freundlich and Langmuir isotherm models. The maximum adsorption capacity of copper and cadmium was calculated from Langmuir isotherm and found to be 20.8 and 19.5 mg/g, respectively. The sorption kinetics of the copper and cadmium have been analysed by Lagergren pseudo-first-order and pseudo-second-order kinetic models. The desorption studies were carried out using dilute hydrochloric acid solution and the effect of HCl concentration on desorption was also studied. Maximum desorption of 90% for copper and 88% for cadmium occurred with 0.2 M HCl. PMID:16191464

Rao, M Madhava; Ramesh, A; Rao, G Purna Chandra; Seshaiah, K

2006-02-28

291

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

292

Removal of Cu2+ and Ag+ from aqueous solution on a chemically-carbonized sorbent from date palm leaflets.  

PubMed

A chemically-carbonized sorbent was prepared from date palm leaflets by sulphuric acid treatment at 170 degrees C. Carbonization took place via the dehydration effect of the hot sulphuric acid producing a carbon with reduction property. Sorption of Cu2+ and Ag+ from aqueous solution was investigated in terms of pH, contact time, metal concentration and temperature. A peculiar behaviour was found for the sorption of the two metals on the produced carbon. Sorption of Cu2+ was fast, reaching equilibrium within -2 h, whilst Ag+ sorption was slow and required -60 h to reach equilibrium. Activation energy (E(a)) for Cu2+ sorption was -16.1 kJ/mol indicating a diffusion-controlled ion exchange process; however, E(a) for Ag+ sorption was -44.3 kJ/mol indicating a chemically controlled process. Equilibrium sorption data were tested for the Langmuir and Freundlich equations. Sorption capacity appears to be much higher for Ag+ than for Cu2+ with increased uptake, for both metals, when increasing the temperature (25-45 degrees C). Ag+ was reduced to elemental silver on the sorbent surface and this was confirmed using scanning electron microscopy and x-ray powder diffraction; however, no reduction processes were involved in Cu2+ sorption. This paper discusses the sorption mechanism. PMID:23530353

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

2013-01-01

293

Dispersion of Single-Walled Carbon Nanotube Bundles in Non-Aqueous Solution  

E-print Network

@u-gakugei.ac.jp ABSTRACT We report the observation of photoluminescence from SWNTs dispersed in a tetrahydrofuran the observation of photoluminescence from SWNTs dispersed in a tetrahydrofuran(THF)/octylamine solution, providing to 10 mL of a 0.01 M solution of 1-octylamine in tetrahydrofuran (THF) and then sonicated for 1 h

Maruyama, Shigeo

294

Oxygen and hydrogen peroxide reduction catalyses in neutral aqueous media using copper ion loaded glassy carbon electrode electrolyzed in ammonium carbamate solution  

Microsoft Academic Search

An aminated glassy carbon electrode (AGCE) can be obtained by the electrode oxidation of glassy carbon electrode in ammonium carbamate solution. In the cyclic voltammetric experiments, the electrode reduction of the dissolved oxygen began from ?0.15V vs. Ag\\/AgCl in neutral aqueous media when the aminated glassy carbon electrode was used as a working electrode although it began from ?0.40V vs.

Hiroaki Watanabe; Haruhito Yamazaki; Xiuyun Wang; Shunichi Uchiyama

2009-01-01

295

Washing of field weathered crude oil contaminated soil with an environmentally compatible surfactant, alkyl polyglucoside.  

PubMed

Weathered crude oil contaminated soils (COCSs), which are much more difficult to remediate than those freshly contaminated, are widespread especially at the sites of oil fields and industries. Surfactant enhanced ex situ soil washing could be used to remediate COCSs, but surfactant toxicity becomes one of the major concerns. In this study, a class of green surfactants, alkyl polyglucosides (APGs), were tested in washing the field weathered COCS with relatively high oil concentration (123 mgg(-1) dry soil) from Jilin Oilfield, Northeastern China. APG1214, characterized with longer alkyl chain, was more effective than APG0810 in crude oil removal. Adding inorganic sodium salts into APG1214 solution further improved the crude oil removal efficiency (CORE). Washing parameters (temperature, washing time, agitation speed and solution/soil ratio) were investigated and further optimized integratedly with an orthogonal design. At the optimum conditions, the CORE reached 97%. GC/MS analysis showed that the proportion of small n-alkanes (C(16)-C(23)) in residual crude oil gradually increased, which was helpful to interpret the oil removal mechanism. Moreover, eminent effect on removal of large n-alkanes was achieved from the synergy between APG1214 and inorganic salts, which was opposite to the effect when they were added separately. This study demonstrated a promising way to remediate COCS with ecologically compatible surfactant and provided guidelines for its practical application. PMID:19493558

Han, Mei; Ji, Guodong; Ni, Jinren

2009-07-01

296

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

297

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

298

Improved mechanical properties of solution-cast silicone film reinforced with electrospun polyurethane nanofiber containing carbon nanotubes  

NASA Astrophysics Data System (ADS)

In this study, we describe the enhancing ability of electrospun polyurethane (PU) nanofibers containing carbon nanotubes (CNTs) as nanofillers for silicone film in improving the physico-mechanical properties of the composite material. We prepared the samples combining two simple techniques: solution casting and electrospinning. Neat PU nanofibers alone are good reinforcing materials but the presence of CNTs inside the PU nanofibers has drastically improved the mechanical properties of the silicone composite film. The silicone film increased its tensile strength by 226% and its tensile modulus by more than 14-fold when CNT/PU nanofibers were incorporated.

Tijing, Leonard D.; Park, Chan-Hee; Kang, Seung-Ji; Amarjargal, Altangerel; Kim, Tae-Hyung; Pant, Hem Raj; Kim, Han Joo; Lee, Dong Hwan; Kim, Cheol Sang

2013-01-01

299

Laboratory Determination of the Carbon Kinetic Isotope Effects (KIEs) for Reactions of Methyl Halides with Various Nucleophiles in Solution  

Microsoft Academic Search

Large carbon kinetic isotope effects (KIEs) were measured for reactions of methyl bromide (MeBr), methyl chloride (MeCl),\\u000a and methyl iodide (MeI) with various nucleophiles at 287 and 306 K in aqueous solutions. Rates of reaction of MeBr and MeI\\u000a with H2O (neutral hydrolysis) or Cl? (halide substitution) were consistent with previous measurements. Hydrolysis rates increased with increasing temperature\\u000a or pH

Shaun M. Baesman; Laurence G. Miller

2005-01-01

300

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

Microsoft Academic Search

Transport of solutes and particulate materials and their variation with discharge were studied for 1 year (July 1980-June 1981) in the Gambia River in the tropical savanna of West Africa. The water is a dilute solution of SiOâ and HCOâ⁻. Na\\/sup +\\/, K\\/sup +\\/, Cl⁻, and total dissolved nitrogen showed no significant relation with discharge. Ca\\/sup 2 +\\/, Mg\\/sup 2

LANCE F. W. LESACK; ROBERT E. HECKY; JOHN M. MELACK

1984-01-01

301

Reaction and nucleation mechanisms of copper electrodeposition from ammoniacal solutions on vitreous carbon  

Microsoft Academic Search

The reaction and nucleation mechanisms of the electrodeposition of copper from ammoniacal solutions were investigated by cyclic voltammetric (cv) and chronoamperometric (ca) techniques, respectively. Each experiment with both electrochemical techniques was followed by morphological studies by atomic force microscopy (AFM). With respect to pH, the studies were performed on ammoniacal solutions at pH 4, pH 6, and pH 8, each

Darko Grujicic; Batric Pesic

2005-01-01

302

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

303

Agricultural based activated carbons for the removal of dyes from aqueous solutions: A review  

Microsoft Academic Search

This review evaluates a number of different agricultural waste adsorbents and types of dyes. Certain wastewater containing different dye contaminants causes serious environmental problems. Recently, growing research interest in the production of carbon based has been focused on agricultural by-products. Low cost adsorbents derived from agricultural wastes have demonstrated outstanding capabilities for the removal of dyes from wastewater. Therefore, low

Ayhan Demirbas

2009-01-01

304

Highly transparent and conductive carbon nanotube coatings deposited on flexible polymer substrate by solution method  

Microsoft Academic Search

Transparent single-walled carbon nanotubes (SWCNT) based flexible conductive coatings have found great application potentials in flexible displays and solar cells. In this paper we report a simple method for the fabrication of this type of conductive coatings. By using plasma treatment of the flexible polymer substrates, the fabrication of SWCNT flexible coating can be easily achieved through a simple dip

Gaozhi Xiao; Ye Tao; Jianping Lu; Zhiyi Zhang

2010-01-01

305

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 ...

306

Preparation and Characterization of Carbon Nanotube Reinforced Polyetherimide Composites by Solution Mixing Method  

E-print Network

Preparation and Characterization of Carbon Nanotube Reinforced Polyetherimide Composites nanotubes in the nano-composites was characterized by field scanning electron microscope( FESEM/MWNT composite showing good adhesion left (0.5 wt% MWNT) and dispersion right (1.0 wt%, (MWNT) Polyetherimide

Collins, Gary S.

307

Adsorption of antimony and arsenic from a copper electrorefining solution onto activated carbon  

Microsoft Academic Search

Removal of arsenic, antimony and bismuth impurities from copper electrolytes is a primary target in copper electrorefineries. The present work investigates the possibilities of carbon adsorption technology in the removal of arsenic and antimony from a real Chilean electrolyte. Various variables which affect the metal adsorption\\/desorption operations are studied.

P. Navarro; F. J. Alguacil

2002-01-01

308

Solution synthesis of magnesium hydroxide sulfate hydrate nanobelts using sparingly soluble carbonate salts as supersaturation control agents.  

PubMed

Magnesium hydroxide sulfate hydrate (MHSH, 5Mg(OH)(2)MgSO(4)3H(2)O) nanobelts were synthesized under the conditions of ambient pressure and boiling temperature (approximately 101 degrees C). Several sparingly soluble carbonate salts were selected based on the hypothesis that the sparingly soluble carbonate salts in aqueous solution can provide OH(-) ion in a slow and continual manner, which is important to maintain a low supersaturation environment for one-dimensional MHSH nanobelt growth. The results indicated that the concentration of the reaction ions in the solution is one of the critical parameters for nanobelt growth. Scanning electron microscopy (SEM) showed that the nanobelts are about 50 nanometers in thickness, 200-500 nanometers in width and tens to hundreds of micrometers in length. The higher the solubility product constant of the sparingly soluble salt, the faster the reaction occurred. The effect of temperature on the reaction rate was investigated. The chemistry of the reaction was studied and the mechanism of nanobelt growth was proposed. PMID:17714726

Zhou, Zhengzhi; Deng, Yulin

2007-12-01

309

Enhanced stability and chemical resistance of a new nanoscale biocatalyst for accelerating CO2 absorption into a carbonate solution.  

PubMed

A novel potassium-carbonate-based absorption process is currently being developed to reduce the energy consumption when capturing CO2 from coal combustion flue gas. The process employs the enzyme carbonic anhydrase (CA) as a catalyst to accelerate the rate of CO2 absorption. This study focused on the immobilization of a new variant of the CA enzyme onto a new group of nonporous nanoparticles to improve the enzyme's thermal stability and its chemical resistance to major impurities from the flue gas. The CA enzyme was manufactured at the pilot scale by a leading enzyme company. As carrier materials, two different batches of SiO2-ZrO2 composite nanoparticles and one batch of silica nanoparticle were synthesized using a flame spray pyrolysis method. Classic Danckwerts absorption theory with reaction was applied to determine the kinetics of the immobilized enzymes for CO2 absorption. The immobilized enzymes retained 56-88% of their original activity in a K2CO3/KHCO3 solution over a 60-day test period at 50 °C, compared with a 30% activity retention for their free CA enzyme counterpart. The immobilized CA enzymes also revealed improved chemical stability. The inactivation kinetics of the free and immobilized CA enzymes in the K2CO3/KHCO3 solution were experimentally quantified. PMID:24187930

Zhang, Shihan; Lu, Hong; Lu, Yongqi

2013-12-01

310

In situ electron microscopy studies of calcium carbonate precipitation from aqueous solution with and without organic additives.  

PubMed

For the understanding of mineral formation processes from solution it is important to obtain a deeper insight into the dynamics of crystal growth. In this study we applied for this purpose a novel atmospheric scanning electron microscope that allows the investigation of CaCO3 particle formation in solution under atmospheric conditions with a resolution of approximately 10nm. Furthermore it permits the in situ observation of the dynamics of crystal evolution. With this tool the precipitation of CaCO3 was studied in the absence and presence of additives, namely poly(acrylic acid) and poly(styrene sulfonate-co-maleic acid) which are known to influence the crystal growth rate and morphology. We determined particle growth rates and investigated the formation and dissolution dynamics of an observed transient phase, believed to be amorphous calcium carbonate. This technique also enabled us to study the depletion zones, areas of lower intensity due to reduced ion concentrations. Ion flux rates were obtained from the depletion zone width, which amounted to several ?m assuming the formation and dissolution dynamics of amorphous calcium carbonate being the rate determining process. This assumption was confirmed since the obtained fluxes were found to be in good agreement with fluxes derived from the experimentally observed crystal growth rates. PMID:23742840

Verch, Andreas; Morrison, Ian E G; Locht, Renee van de; Kröger, Roland

2013-08-01

311

Evaluation of alkanolamine solutions for carbon dioxide removal in cross-flow rotating packed beds.  

PubMed

The removal of CO(2) from a 10 vol% CO(2) gas by chemical absorption with 30 wt% alkanolamine solutions containing monoethanolamine (MEA), piperazine (PZ), and 2-amino-2-methyl-1-propanol (AMP) in the cross-flow rotating packed bed (RPB) was investigated. The CO(2) removal efficiency increased with rotor speed, liquid flow rate and inlet liquid temperature. However, the CO(2) removal efficiency decreased with gas flow rate. Also, the CO(2) removal efficiency was independent of inlet gas temperature. The 30 wt% alkanolamine solutions containing PZ with MEA were the appropriate absorbents compared with the single alkanolamine (MEA, AMP) and the mixed alkanolamine solutions containing AMP with MEA. A higher portion of PZ in alkanolamine solutions was more favorable to CO(2) removal. Owing to less contact time in the cross-flow RPB, alkanolamines having high reaction rates with CO(2) are suggested to be used. For the mixed alkanolamine solution containing 12 wt% PZ and 18 wt% MEA, the highest gas flow rate allowed to achieve the CO(2) removal efficiency more than 90% at a liquid flow rate of 0.54 L/min was of 29 L/min. The corresponding height of a transfer unit (HTU) was found to be less than 5.0 cm, lower than that in the conventional packed bed. PMID:19910115

Lin, Chia-Chang; Lin, Yu-Hong; Tan, Chung-Sung

2010-03-15

312

Accuracy of three polyvinyl siloxane putty-wash impression techniques  

Microsoft Academic Search

Statement of problem. There is much discussion in the dental literature concerning the effect of the impression technique on the accuracy of cast restorations.Purpose. This study assessed the accuracy of 3 putty-wash impression techniques using the same impression material (polyvinyl siloxane) in a laboratory model.Material and methods. The 3 putty-wash impression techniques used were (1) 1-step (putty and wash impression

Joseph Nissan; Ben-Zion Laufer; Tamar Brosh; David Assif

2000-01-01

313

Treatment of recycled carrot washing water.  

PubMed

Large volumes of effluents and solid waste derive from industrial fresh packing and processing of carrots. Due to high organic loads and suspended solids and due to insufficient wastewater treatment, surface waters are polluted by effluents of carrot washing, as shown for one enterprise in Germany. Over a period of four months the water quality was studied at the stages of a treatment system consisting of a grit chamber, a settling tank combined with aeration devices and a constructed wetland. Organic pollutants were measured as COD and BOD5 in different fractions of the wastewater. The daily washing of carrots produces up to 300 m3 wastewater with a mean filterable solids content of 453 mg l(-1) and a mean COD concentration of 179 mg l(-1). On average the current efficiency of total COD reduction is 52%. Due to the fine grain size and the low density of suspended solids, settling is very slow and incomplete, primarily during the winter. As much as 29 mg COD l(-1) in the effluent derive from the fraction of particles which do not settle within 18 hours. The dissolved COD fraction accounts for 30 mg l(-1) and reflects the insufficient oxygenation of the wastewater. Strategies for enhancing the removal of organic compounds can be derived from the results of this study. Spatial separation of settling and aeration processes is recommended to optimise the treatment process. Furthermore, the area of the constructed wetland should be increased to maintain its hydraulic conductivity and to guarantee a high COD reduction. PMID:16583829

Kern, J; Reimann, W; Schlüter, O

2006-04-01

314

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

315

Isotopic geochemistry of the Saratoga springs: Implications for the origin of solutes and source of carbon dioxide  

NASA Astrophysics Data System (ADS)

We report the results of an isotopic study designed to determine the source of solutes and carbon dioxide in the famed Saratoga Springs (New York) mineral waters. These waters have thousands of milligrams per liter total dissolved solid concentrations and are highly charged with carbon dioxide gas. The spring waters are cold (˜12 °C) and there is no local, deep-seated thermal anomaly. They emerge through thick shale caprock along the surface expression of normal faults. The ?13C (-5.8‰ to +0.8‰ Vienna Peedee belemnite) of the dissolved inorganic carbon and elevated 3He/4He ratios suggest that the source of the CO2 is the mantle or an ancient deep crystallized igneous melt. The stable isotopic content of the spring waters defines a mixing line between modern local meteoric waters (? ˜ 70‰) and a component with heavier ?D but similar ?18O values. This trend and that of 87Sr/86Sr of dissolved strontium versus 1/Sr are consistent with the hypothesis that Canadian Shield type brines contribute salinity to the springs. These brines plausibly migrate from the Adirondack Mountains to the topographically low McGregor fault system in the Hudson River lowlands, where the Saratoga springs discharge.

Siegel, Donald I.; Lesniak, Keri A.; Stute, Martin; Frape, Shaun

2004-03-01

316

Corrosion inhibition of carbon steel in 0.5 M NaCl aqueous solution by humid air plasma treatment  

NASA Astrophysics Data System (ADS)

Carbon steel (C75) is exposed to highly reactive species such as hydroxyl radicals OH created by a gliding arc discharge (GAD) in humid air at atmospheric pressure. The protective properties of carbon steel treated by GAD are studied versus different treatment times (t) and for an immersion in corroding 0.5 M sodium chloride solution during 24 h. Evolutions of corrosion rate are studied using weight loss measurements and electrochemical methods, e.g., electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The results obtained by GAD treatment show that the corrosion rate of steel decreases with the ennoblement of the corrosion potential and the decrease of the corrosion current density. This indicates that the plasma treatment acts as an anodic type inhibitor and suggests the formation of a protective layer. EIS measurements confirm the presence of this film: the charge transfer resistance (Rct) increases with GAD treatment time, leading to a corrosion inhibition efficiency around 73% for a treatment time equal to 60 min. This confirms the importance of the plasma effect. The gliding arc discharge is a clean and efficient technology for the surface treatment of carbon steel; it improves the anticorrosion properties of steel in aggressive environments, forming a resistant and insulating barrier.

Ghali, Noureddine; Addou, Ahmed; Mutel, Brigitte; Benstaali, Baghdad; Bentiss, Fouad; Brisset, Jean-Louis

2013-02-01

317

Adsorption of phenolic compounds from aqueous solutions using carbon nanoporous adsorbent coated with polymer  

NASA Astrophysics Data System (ADS)

Phenolic compounds are a widespread class of water pollutants that are known to cause serious human health problems; and the demand for effective adsorbents for the removal of toxic compounds is increasing. In this work adsorption of phenol, resorcinol and p-cresol on mesoporous carbon material (CMK-1) and modified with polyaniline polymer (CMK-1/PANI) has been investigated in attempt to explore the possibility of using nanoporous carbon as an efficient adsorbent for pollutants. It was found that CMK-1/PANI exhibits significant adsorption for phenolic derivatives. Batch adsorption studies were carried out to study the effect of various parameters like adsorbent dose, pH, initial concentration and contact time. From the sorption studies it was observed that the uptake of resorcinol was higher than other phenolic derivatives. Freundlich and Langmuir adsorption isotherms were used to model the equilibrium adsorption data for phenolic compounds.

Anbia, Mansoor; Ghaffari, Arezoo

2009-09-01

318

Role of titania incorporated on activated carbon cloth for capacitive deionization of NaCl solution.  

PubMed

Adsorption isotherms of NaCl on activated carbon cloth (ACC) and titania-incorporated activated carbon cloth (Ti-ACC) under an electric field were investigated to deduce the role of titania in capacitive deionization (CDI) of NaCl. Electrosorption of NaCl on the ACC was significantly increased by titania incorporation, whereas its physical adsorption was considerably decreased, resulting in an improved performance of the Ti-ACC as a CDI electrode. Langmuir isotherms based on a localized and fixed amount of adsorption were suitable for the simulation of electrosorption and physical adsorption of ions on the ACC electrodes. The variances of q(m) and b of Langmuir isotherms with electric potential indicate increases in the number of ions per adsorption site and in electrosorption strength of ions by titania incorporation. A cyclic voltammetric study for ion adsorption on ACC electrodes confirms the reversibility between electrosorption and desorption of ions, regardless of titania incorporation. PMID:16256660

Ryoo, Min-Woong; Kim, Jong-Ho; Seo, Gon

2003-08-15

319

Removal of ?-nitrophenol from aqueous solution by magnetically modified activated carbon  

NASA Astrophysics Data System (ADS)

Activated carbon was modified with ?-Fe2O3 nanoparticles, using the chemical co-precipitation technique and the carboxylic acid vapor treatment technique. Two magnetic composites were characterized and compared by Fourier Transform Infrared spectroscopy, X-ray diffractometry, vibrating sample magnetometry and nitrogen adsorption-desorption. Then the two materials were used to remove p-nitrophenol in water. The equilibrium data revealed that the Langmuir isotherm was better in fitting the experiment result than the Freundlich isotherm, and the sorption capacity of the nanocomposite made by the chemical co-precipitation technique was higher than that of the other one. We suggest that the chemical co-precipitation technique is a more efficient and practical method to produce magnetically modified activated carbon.

Han, Shuai; Zhao, Feng; Sun, Jian; Wang, Bin; Wei, Rongyan; Yan, Shiqiang

2013-09-01

320

Facile surface modification of nanoprecipitated calcium carbonate by adsorption of sodium stearate in aqueous solution  

Microsoft Academic Search

A simple and solvent free two-step process for nanosized and surface-modified precipitated calcium carbonate (ns-PCC) synthesis has been proposed. Synthesized ns-PCC was thoroughly characterized by infra-red (IR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Langmuir adsorption study. Dynamic laser scattering (DLS) results on particle size showed a good correlation with those obtained by the proposed empirical model. Two aspects

Hoang Vinh Tran; Lam Dai Tran; Hoang Dinh Vu; Hoang Thai

2010-01-01

321

Factors affecting the bacteriological contamination of commercial washing machines.  

PubMed

Wash water from self-service washing machines in three commercial launderettes of Bologna (Italy) were examined to verify which factors affect their bacterial contamination and to determine which procedures in the laundering process have the most significant effects on the removal of bacteria. Four washing formulas were compared: a delicates cycle (programmed temperature 25-30 degrees C; actual temperature: 28-31 degrees C); a whites cycle (programmed temperature: 80-90 degrees C; actual temperature: 50-57.5 degrees C); a delicates cycle with the addition of an oxygen-based bleach safe for delicate fabrics and a whites cycle with the addition of an oxygen-based bleach. Bacterial contamination of washing machines was higher in the launderette most heavely used, and, furthermore, it was in relation with the washing temperature and the use of bleaches. The low temperature laundering cycle (20-30 degrees C) did not guarantee elimination of bacterial content from either the inside of the washing machine or from the fabric being washed. Washing with water at a higher temperature, of about 55 degrees C, or adding an oxygen-based bleach to the low temperature cycle did ensure a significant reduction in bacterial recovery from water samples and fabrics, but did not prevent bacteria such as P. aeruginosa from surviving inside the washing machine. Only the addition of bleaches to the hot water program ensured the almost total elimination of bacteria and also guaranteed their elimination from protected parts of the drum. PMID:9638885

Legnani, P P; Leoni, E

1997-10-01

322

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

323

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

324

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

325

Immobilized nickel hexacyanoferrate on activated carbons for efficient attenuation of radio toxic Cs(I) from aqueous solutions  

NASA Astrophysics Data System (ADS)

The aim of this study is to immobilize nickel hexacyanoferrate onto the large surface of activated carbons (ACs) precursor to rice hulls and areca nut waste materials. These nickel hexacyanoferrate immobilized materials are then assessed in the effective attenuation of radio logically important cesium ions from aqueous solutions. The solid samples are characterized by the XRD analytical method and surface morphology is obtained from the SEM images. The batch reactor experiments show that an increase in sorptive pH (2.0-10.0) apparently not affecting the high percent uptake of Cs(I). Equilibrium modeling studies suggest that the data are reasonably and relatively fitted well to the Langmuir adsorption isotherm. Kinetic studies show that sorption process is fairly rapid and the kinetic data are fitted well to the pseudo-second order rate model. Increasing the background electrolyte concentration from 0.001 to 0.1 mol/L NaCl causes insignificant decrease in Cs(I) removal which infers the higher selectivity of these materials for Cs(I) from aqueous solutions. Further, the column reactor operations enable to obtain the breakthrough data which are then fitted to the Thomas non-linear equation as to obtain the loading capacity of column for Cs(I). The results show that the modified materials show potential applicability in the attenuation of radio toxic cesium from aqueous solution.

Lalhmunsiama; Lalhriatpuia, C.; Tiwari, Diwakar; Lee, Seung-Mok

2014-12-01

326

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

327

Sodium carbonate as phase promoter in aqueous solutions of imidazolium and pyridinium ionic liquids  

Microsoft Academic Search

Several methylsulfate and chloride anion-based ionic liquids, such as 1-alkyl-3-methyl imidazolium methyl sulfate, CnMIM CH3SO4 (n=1, 2, and 4), 1-benzyl-3-methyl imidazolium methyl sulfate, BzMIM CH3SO4, 1-benzyl, or hexyl-3-methyl imidazolium chloride, XMIM Cl (X=Bz and Hx), and methylpyridinium methylsulfate, Mpy CH3SO4, with sodium carbonate, Na2CO3, as phase forming salt, have been investigated and discussed for their potential use in separations based

Francisco J. Deive; Miguel A. Rivas; Ana Rodríguez

2011-01-01

328

Carbon-modified electrode for ultra trace determination of Cd (II) in aqueous solution  

NASA Astrophysics Data System (ADS)

Increasing contamination of water by trace levels of heavy metals has become major environmental threats leading to an increased demand for the detection and monitoring of metal contaminants. In this work, modification of carbon electrode for Cd2+ detection using square wave anodic stripping voltammetry was reported. The deposition potential of -1.0 V in 0.1M acetate buffer for 240 sec, followed by square wave potential scan from -1.0 to -0.2 V were used. Stripping voltammogram showed current peaks corresponding to Cd2+. The sensitivity and selectivity of the modified electrodes for Cd2+ were also determined.

Almustapha, Sakinatu; Khan, Aamir Amanat Ali; Omar, Abdul Aziz; Ariwahjoedi, Bambang; Abdullah, Mohd Azmuddin

2014-10-01

329

Crude oil contaminated soil washing in air sparging assisted stirred tank reactor using biosurfactants.  

PubMed

This study investigated the removal of crude oil from soil using air sparging assisted stirred tank reactors. Two surfactants (rhamnolipid and sodium dodecyl sulfate, SDS) were tested and the effects of different parameters (i.e. temperature, surfactant concentrations, washing time, volume/mass ratio) were investigated under varying washing modes namely, stirring only, air sparging only and the combination of stirring and air sparging. The results showed that SDS removed more than 80% crude oil from non-weathered soil samples, whilst rhamnolipid showed similar oil removal at the third and fourth levels of the parameters tested. The oil removal ability of the seawater prepared solutions were better than those of the distilled water solutions at the first and second levels of temperature and concentration of surfactant solutions. This approach of soil washing was noted to be effective in reducing the amount of oil in soil. Therefore we suggested that a field scale test be conducted to assess the efficiency of these surfactants. PMID:15924952

Urum, Kingsley; Pekdemir, Turgay; Ross, David; Grigson, Steve

2005-07-01

330

Electrooxidation of stainless steel AISI 304 in carbonate aqueous solution at pH 8  

Microsoft Academic Search

The electrochemical behaviour of stainless steel AISI 304 (SS304) has been investigated in deaerated 0.1–1 m NaHCO3 solutions at pH 8 using a rotating disc electrode. The polarization curves are characterized by a broad range of passivity at low potentials (-0.8 to 0.3 V), a depassivation region at 0.4 V vs SCE and, at high potentials (0.5 to 0.85 V),

M. Drogowska; H. Ménard; L. Brossard

1996-01-01

331

Evaluation of alkanolamine solutions for carbon dioxide removal in cross-flow rotating packed beds  

Microsoft Academic Search

The removal of CO2 from a 10vol% CO2 gas by chemical absorption with 30wt% alkanolamine solutions containing monoethanolamine (MEA), piperazine (PZ), and 2-amino-2-methyl-1-propanol (AMP) in the cross-flow rotating packed bed (RPB) was investigated. The CO2 removal efficiency increased with rotor speed, liquid flow rate and inlet liquid temperature. However, the CO2 removal efficiency decreased with gas flow rate. Also, the

Chia-Chang Lin; Yu-Hong Lin; Chung-Sung Tan

2010-01-01

332

CORROSION TESTING OF CARBON STEEL IN OXALIC ACID CHEMICAL CLEANING SOLUTIONS  

SciTech Connect

Radioactive liquid waste has been stored in underground carbon steel tanks for nearly 60 years at the Savannah River Site. The site is currently in the process of removing the waste from these tanks in order to place it into vitrified, stable state for longer term storage. The last stage in the removal sequence is a chemical cleaning step that breaks up and dissolves metal oxide solids that cannot be easily pumped out of the tank. Oxalic acid has been selected for this purpose because it is an effective chelating agent for the solids and is not as corrosive as other acids. Electrochemical and immersion studies were conducted to investigate the corrosion behavior of carbon steel in simulated chemical cleaning environments. The effects of temperature, agitation, and the presence of sludge solids in the oxalic acid on the corrosion rate and the likelihood of hydrogen evolution were determined. The testing showed that the corrosion rates decreased significantly in the presence of the sludge solids. Corrosion rates increased with agitation, however, the changes were less noticeable.

Wiersma, B.; Mickalonis, J.; Subramanian, K.; Ketusky, E.

2011-10-14

333

Adsorption removal of acid black 1 from aqueous solution using ordered mesoporous carbon  

NASA Astrophysics Data System (ADS)

A novel ordered mesoporous carbon CMK-3 and synthetic CMK-3 containing nitrogen functional groups by ammonia-treated were applied for acid black 1(AB1) dye adsorption. The ammonia-treated(chemical vapor deposition method) before and after CMK-3 were characterized by using a Micrometitics ASAP 2020 surface area analyzer (ASAP 2020), Fourier transform infrared spectrophotometer (FT-IR), X-ray Photoelectron Spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscope (SEM) and equilibrium studies. This result indicates that the prepared CMK-3 and modified CMK-3 were almost uniform, as rope-like domains and their uniform mesopore with diameter centered at 3.2 nm and 3.7 nm. The FIIR analysis depicted that the presence of a variety of new basic functional groups on the modified CMK-3 surface. Several effect variables of pH, dye concentration and temperature were studied. The pseudo second-order model showed the ?tter well to agree with the kinetic data. The experimental data were analyzed by the Langmuir and Freundlich models, with the latter found to closely the isotherm model. The adsorption kinetics was found to follow the pseudo-second-order kinetic model. The results show that CMK-3 using ammonia gas modified by thermal treatment system is an effective method to improvement capacity as it shows the highest adsorption capacity of AB1, as compared to the unmodified CMK-3 and the bamboo-based carbon, respectively.

Peng, Xiaoming; Hu, Xijun; Fu, Dafang; Lam, Frank L. Y.

2014-03-01

334

The removal of U(VI) from aqueous solution by oxidized multiwalled carbon nanotubes.  

PubMed

Multiwalled carbon nanotubes (MWCNTs) have exhibited high sorption capacity for radionuclides due to the unique hollow structure and large surface area. In this study, surface properties of oxidized MWCNTs were characterized by using XRD, SEM, FTIR and potentiometric acid-base titration. The sorption of U(VI) on oxidized MWCNTs as a function of contact time, U(VI) concentration, pH, ionic strength, humic acid/fulvic acid (HA/FA) and carbonate was investigated by using batch technique. The removal of U(VI) by oxidized MWCNTs was strongly dependent on pH and ionic strength. The presence of HA/FA enhanced U(VI) removal on oxidized MWCNTs at low pH while inhibited U(VI) sorption at high pH. The mechanism of U(VI) sorption on oxidized MWCNTs was assumed to be cation exchange/outer-sphere surface complexation in acidic pH and to form precipitation under circum neutral conditions. The oxidized MWCNTs exhibit higher sorption capacity and stronger chemical affinity than pristine MWCNTs. PMID:22230020

Sun, Yubing; Yang, Shitong; Sheng, Guodong; Guo, Zhiqiang; Wang, Xiangke

2012-02-01

335

Caustic washing for refining of direct coal liquefaction products  

SciTech Connect

Extensive research and development sponsored by the U.S. DOE/PETC over the past two decades has resulted in dramatic improvements in the quality of direct coal liquefaction products. High-quality coal-derived distillates are obtainable from catalytic two-stage liquefaction (TSL) processes, such as those developed at the Wilsonville, AL pilot plant and the Hydrocarbon Technologies Inc. (HTI) pilot plant and bench units. The products of the Wilsonville and HTI TSL operations are suitable as high quality feedstocks for producing transportation fuels in a refinery. These products have important quality advantages over crude petroleum: they are distillates boiling below about 700{degrees}F and are thus virtually free of resid and metals, and they have very low sulfur contents and low nitrogen contents. The coal liquids have carbon and hydrogen contents and Watson characterization factors within the range of crude petroleums. However, relative to crude petroleum, the crude coal products have elevated oxygen contents. This report describes the removal of phenols from coal liquids by caustic washing, and the the recovery of the cresylic acid by-product.

Winschel, R.A.; Burke, F.P.; Robbins, G.A.; Brandes, S.D. [CONSOL, Inc., Library, PA (United States); Zhou, P. [Burns and Roe Services Corp., Pittsburgh, PA (United States)

1995-12-31

336

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

337

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

338

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.interscience.wiley.com). Keywords: biosorption, adsorption modeling, crab shells, chromate speciation Introduction The removal genetic damage.1 Niu and Volesky2 proposed an acid washed crab (ucides cordatus) shell (AWCS) biosorption

Volesky, Bohumil

339

33 CFR 162.235 - Puget Sound Area, Wash.  

...2014-07-01 2014-07-01 false Puget Sound Area, Wash. 162.235 Section 162...NAVIGATION REGULATIONS § 162.235 Puget Sound Area, Wash. (a) Waterway connecting...one short whistle. Southbound boats shall sound the signal within 600 yards of Port...

2014-07-01

340

What to do About Your Skin Infection Wash your hands  

E-print Network

What to do About Your Skin Infection Wash your hands Shower daily using soap Change into clean with a bandage. If your bandage comes off, throw it away in a plas- tic bag and wash your hands. Tell time or use an antiseptic hand sanitizer. Before eating. After using the toilet. After blowing

341

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...

342

Geoarchaeology of the Boca Negra Wash Area, Albuquerque Basin,  

E-print Network

Geoarchaeology of the Boca Negra Wash Area, Albuquerque Basin, New Mexico, USA Vance T. Holliday,1, University of New Mexico, Albuquerque, NM 87131 3 Department of Geosciences, University of Arizona, Tucson, University of New Mexico, Albuquerque, NM 87131 Dozens of Paleoindian sites, including the Boca Negra Wash

Holliday, Vance T.

343

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

344

BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING NORTHWEST. PIPING ...  

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

BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING NORTHWEST. PIPING IN FOREGROUND IS NOT RELATED TO THE MACHINE. THE NORTHEAST CORNER OF SETTLING RESERVOIR NO. 3 IS SEEN AT THE LOWER LEFT. - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

345

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

346

49 CFR 230.60 - Time of washing.  

Code of Federal Regulations, 2012 CFR

...washing. All boilers shall thoroughly be washed as often as the water conditions require, but not less frequently than at each...arch tube plugs, thermic siphon plugs, circulator plugs and water bar plugs must be removed whenever locomotive boilers are...

2012-10-01

347

49 CFR 230.60 - Time of washing.  

Code of Federal Regulations, 2013 CFR

...washing. All boilers shall thoroughly be washed as often as the water conditions require, but not less frequently than at each...arch tube plugs, thermic siphon plugs, circulator plugs and water bar plugs must be removed whenever locomotive boilers are...

2013-10-01

348

49 CFR 230.60 - Time of washing.  

Code of Federal Regulations, 2011 CFR

...washing. All boilers shall thoroughly be washed as often as the water conditions require, but not less frequently than at each...arch tube plugs, thermic siphon plugs, circulator plugs and water bar plugs must be removed whenever locomotive boilers are...

2011-10-01

349

Reducing the Spread of Infectious Disease Through Hand Washing  

Microsoft Academic Search

According to the Centers for Disease Control (2002), hand washing is the simplest, most effective measure for preventing the spread of bacteria, pathogens, and viruses. Recent studies by the American Society for Microbiology (2005) indicate that Americans do not wash their hands after going to the bathroom and before handling or eating food. The study reported here sought to determine

Marcus M. Comer; Mohammad Ibrahim

350

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

351

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

352

POTENTIAL FOR STRESS CORROSION CRACKING OF A537 CARBON STEEL NUCLEAR WASTE TANKS CONTAINING HIGHLY CAUSTIC SOLUTIONS  

SciTech Connect

The evaporator recycle streams of nuclear waste tanks may contain waste in a chemistry and temperature regime that exceeds the current corrosion control program, which imposes temperature limits to mitigate caustic stress corrosion cracking (CSCC). A review of the recent service history found that two of these A537 carbon steel tanks were operated in highly concentrated hydroxide solution at high temperature. Visual inspections, experimental testing, and a review of the tank service history have shown that CSCC has occurred in uncooled/un-stress relieved tanks of similar construction. Therefore, it appears that the efficacy of stress relief of welding residual stress is the primary corrosion-limiting mechanism. The objective of this experimental program is to test A537 carbon steel small scale welded U-bend specimens and large welded plates (30.48 x 30.38 x 2.54 cm) in a caustic solution with upper bound chemistry (12 M hydroxide and 1 M each of nitrate, nitrite, and aluminate) and temperature (125 C). These conditions simulate worst-case situations in these nuclear waste tanks. Both as-welded and stress-relieved specimens have been tested. No evidence of stress corrosion cracking was found in the U-bend specimens after 21 days of testing. The large plate test was completed after 12 weeks of immersion in a similar solution at 125 C except that the aluminate concentration was reduced to 0.3 M. Visual inspection of the plate revealed that stress corrosion cracking had not initiated from the machined crack tips in the weld or in the heat affected zone. NDE ultrasonic testing also confirmed subsurface cracking did not occur. Based on these results, it can be concluded that the environmental condition of these tests was unable to develop stress corrosion cracking within the test periods for the small welded U-bends and for the large plates, which were welded with an identical procedure as used in the construction of the actual nuclear waste tanks in the 1960s. The absence of evidence of stress corrosion cracking and general corrosion in the laboratory-scaled specimens indicate that this type of nuclear waste tank is not susceptible to highly caustic solutions up to 12 M hydroxide at 125 C when sufficient nitrite inhibitor is present.

Lam, P.; Stripling, C.; Fisher, D.; Elder, J.

2010-04-26

353

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

354

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

355

Surface film formation on nickel electrodes in a propylene carbonate solution at elevated temperatures  

NASA Astrophysics Data System (ADS)

The effect of temperature on surface film formation on nickel electrode was studied in 1 mol dm -3 bis(perfluoroethylsulfonyl)imide dissolved in propylene carbonate by atomic force microscopy (AFM) and ac impedance spectroscopy. Cyclic voltammetry measurements revealed that electrolyte decomposition reactions are accelerated at elevated temperatures, especially at 60 and 80 °C. In situ AFM measurements showed that the film formation is fast and the resulting surface film is thicker at 80 °C than at room temperature. Furthermore, it was confirmed by ac impedance measurements that the resistance of surface film was very low at elevated temperatures. These results were discussed in relation to superior cycling characteristics of lithium deposition and dissolution at the elevated temperatures.

Mogi, Ryo; Inaba, Minoru; Iriyama, Yasutoshi; Abe, Takeshi; Ogumi, Zempachi

356

Solution phase photolysis of 1,2-dithiane alone and with single-walled carbon nanotubes.  

PubMed

Photolysis of 1,2-dithiane (1) in acetonitrile with single walled carbon nanotubes (SWCNTs) was earlier reported to form thiol-functionalized SWCNTs via the butane-1,4-dithiyl diradical (2). The present study shows that 2 instead undergoes a facile rearrangement to thiophane-2-thiol (6). This photoreaction is clean, rapid, and irreversible under 313 nm irradiation. The secondary photolysis of 6 with SWCNTs at a shorter wavelength (254 nm) leads to 2-thiophanyl radicals 8, which derivatize SWCNTs by covalent attachment. Pyrolysis of the resulting "sulfurized SWCNTs" affords a mixture of organosulfur compounds, including thiophene formed by dehydrogenation. An unknown additional mechanism causes high TGA weight loss and a large incorporation of sulfur. PMID:22874092

Engel, Paul S; Gudimetla, Vittal B; Gancheff, Jorge S; Denis, Pablo A

2012-08-16

357

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

358

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

359

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

360

Multi-walled carbon nanotube supported Pd and Pt nanoparticles with high solution affinity for effective electrocatalysis  

NASA Astrophysics Data System (ADS)

Multi-walled carbon nanotubes (MWCNTs) are easily wrapped with a functional biopolymer—polydopamine (Pdop) through self-polymerization of dopamine in a mild basic solution. The MWCNTs@Pdop exhibits long term dispersivity in water for at least one month. The Pdop has large capacity to coordinate [PdCl 4] 2- and [PtCl 6] 2- that upon reduction transform to corresponding metal nanoparticles. The nanoparticles strongly adhere to Pdop layer and can be used for the electrooxidation of haydrazine and methanol, respectively. Compared to Pd and Pt supported on unmodified MWCNTs, the Pd and Pt nanoparticle decorated on MWCNTs@Pdop exhibit much higher electrocatalytic activity and enhanced stability.

Ye, Weichun; Hu, Haiyuan; Zhang, Hong; Zhou, Feng; Liu, Weimin

2010-09-01

361

Elasticity solution of functionally graded carbon-nanotube-reinforced composite cylindrical panel with piezoelectric sensor and actuator layers  

NASA Astrophysics Data System (ADS)

In this paper the bending behavior of a uniform distribution (UD) and a functionally graded carbon-nanotube-reinforced composite (FG-CNTRC) cylindrical panel embedded in piezoelectric layers is investigated. The hybrid cylindrical panel has simply supported boundary conditions and is subjected to mechanical load and electric excitation. The governing equations are based on the three-dimensional theory of elasticity. By using Fourier series expansion along the longitudinal and latitudinal directions for the stress and displacement fields, and the state space technique across the thickness direction, a closed form solution is derived. The accuracy of the present approach is validated by comparing the numerical results with the results obtained in published literature. Finally, the effects of volume fraction of CNTs, cases of CNT distribution, piezoelectric layer thickness, length to thickness ratio and mechanical and electrical loads on the static behavior of the hybrid cylindrical panel are also examined.

Alibeigloo, A.

2013-07-01

362

Stress corrosion cracking of carbon steel in caustic aluminate solutions—crack propagation studies  

Microsoft Academic Search

Stress corrosion cracking of a commercial 0.19 pct C steel (SA-516 Grade 70) was studied in hot (92 ‡C) caustic solutions\\u000a of NaOH and NaOH plus aluminate (AlO?\\u000a 2) species. Potentiostatically controlled tests were conducted near the active-passive transition, using fracture mechanics\\u000a testing techniques and fatigue precracked double cantilever beam specimens. Crack propagation rates (?) were determined for\\u000a a range

Rajagopal Sriram; Desmond Tromans

1985-01-01

363

The inhibiting action of intrinsic impurities in natural calcium carbonate minerals to their dissolution kinetics in aqueous H 2O–CO 2 solutions  

Microsoft Academic Search

We have measured the surface controlled dissolution rates of natural calcium carbonate minerals (limestone and marble) in H2O–CO2 solutions by using free drift batch experiments under closed system conditions with respect to CO2, at 10°C with an initial partial pressure of carbon dioxide of 5 · 10?2 atm. All experiments revealed reaction rates F, which can be described by the

Laurent Eisenlohr; Krassimira Meteva; Franci Gabrovšek; Wolfgang Dreybrodt

1999-01-01

364

46 CFR 153.1065 - Sodium chlorate solutions.  

Code of Federal Regulations, 2010 CFR

...1065 Sodium chlorate solutions. (a) No person may load sodium chlorate solutions into a containment system...spills of sodium chlorate solutions are immediately washed...Approval of Surveyors and Handling of Categories A, B,...

2010-10-01

365

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

366

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

367

Electrochemical properties of spinel-type manganese oxide/porous carbon nanocomposite powders in 1 M KOH aqueous solution  

NASA Astrophysics Data System (ADS)

Spinel-type manganese oxide/porous carbon (Mn3O4/C) nanocomposite powders have been simply prepared by a thermal decomposition of manganese gluconate dihydrate under an Ar gas flow at above 600 °C. The structure and texture of the Mn3O4/C nanocomposite powders are investigated by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) equipped scanning transmission electron microscopy (STEM), transmission electron microscopy (TEM), selected area-electron diffraction (SA-ED), thermogravimetric and differential thermal analysis (TG-DTA) and adsorption/desorption of N2 gas at -196 °C. The electrochemical properties of the nanocomposite powders in 1 M KOH aqueous solution are studied, focusing on the relationship between their structures and electrochemical capacitance.In the nanocomposite powders, Mn3O4 nano particles approximately 5 nm in size are dispersed in a porous carbon matrix. The nanocomposite powders prepared at 800 °C exhibit a high specific capacitance calculated from cyclic voltammogram of 350 and 600 F g-1 at a sweep rate of 1 and 0.1 mV s-1, respectively. The influence of the heating temperature on the structure and the electrochemical properties of nanocomposite powders is also discussed.

Tsumura, Tomoki; Tsumori, Koichiro; Shimizu, Goichi; Toyoda, Masahiro

2012-02-01

368

Linear solvation energy relationship of the limiting partition coefficient of organic solutes between water and activated carbon  

USGS Publications Warehouse

A linear solvation energy relationship has been found for 353 values of the limiting adsorption coefficients of diverse chemicals:? log K = ?0.37 + 0.0341Vi ? 1.07? + D + 0.65P with R = 0.951, s = 0.51, n = 353, and F = 818.0, where Vi is the intrinsic molar volume; ? is a measure of the hydrogen bond acceptor strength of the solute; D is an index parameter for the research group which includes the effects of the different types of carbon used, the temperature, and the length of time allowed for the adsorption equilibrium to be established; and P is an index parameter for the flatness of the molecule. P is defined to be unity if there is an aromatic system in the molecule or if there is a double bond or series of conjugated double bonds with no more that one non-hydrogen atom beyond the double bond and zero otherwise. A slightly better fit is obtained if the two-thirds power of Vi is used as a measure of the surface area in place of the volume term:? log K = ?1.75 + 0.227V2/3 ? 1.10? + D + 0.60P with R = 0.954, s = 0.49, n = 353, and F = 895.39. This is the first quantitative measure of the effect of the shape of the molecule on its tendency to be adsorbed on activated carbon.

Luehrs, Dean C.; Hickey, James P.; Nilsen, Peter E.; Godbole, K.A.; Rogers, Tony N.

1995-01-01

369

Carbon dioxide hydrate equilibrium conditions in aqueous solutions containing electrolytes and methanol using a new apparatus  

SciTech Connect

A knowledge of the gas hydrate formation conditions, i.e. pressure, temperature, and compositions, of the coexisting phases at equilibrium, is required in formulating processes to avoid their formation in natural gas transmission lines or processing equipment. Additives like methanol and electrolytes are often used to inhibit hydrate formation in industrial operations. Computation of the inhibition effects of these additives is necessary for the design of such operations. Development of thermodynamic methods to calculate the hydrate equilibria conditions requires accurate experimental data. In the present work experimental three-phase (aqueous liquid solution, vapor, and incipient hydrate) equilibrium conditions of CO{sub 2} hydrate formation in aqueous solutions of electrolytes and methanol are measured in the temperature range of 263--279 K and pressure range of 0.9--3.0 MPa. A new full view sapphire tube equilibrium cell and the associated equipment are designed, fabricated, and used for the measurements. The equipment details and the measured data are also reported here.

Dholabhai, P.D.; Parent, J.S.; Bishnoi, P.R. [Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering] [Univ. of Calgary, Alberta (Canada). Dept. of Chemical and Petroleum Engineering

1996-03-01

370

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

371

Wheat Gluten Swelling and Partial Solubility with Potential Impact on Starch-from-Gluten Separation by Ethanol Washing  

Microsoft Academic Search

Cereal Chem. 76(6):843-845 Swelling of wheat gluten may be a contributing factor in washing or displacement separation of gluten and starch using cold ethanol. To test this hypothesis, dissolution and swe lling (settled volume or mass absorp- tion) of a commercial gluten are reported here for the first time as a function of both temperature and ethanol solution concentration. In

G. H. Robertson; T. K. Cao; I. Ong

1999-01-01

372

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

373

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

374

Exposure of brown trout (Salmo trutta L.) to tunnel wash water runoff--chemical characterisation and biological impact.  

PubMed

Washing and cleaning of road tunnels are a routinely performed maintenance task, which generate significant amount of polluted wash-water runoff that normally is discharged to the nearest recipient. The present study was designed to quantify chemical contaminants (trace metals, hydrocarbons, PAH and detergents) in such wash water and assess the short term impact on brown trout (Salmo trutta L.) based on in situ experiments. Selected endpoints were accumulation of trace metals in gills, haematological variables and hepatic mRNA transcription of five biomarkers reflecting defence against free radicals, trace metals, planar aromatic hydrocarbons and endocrine disruptions which were measured prior (-3h), during (1 and 3h) and after the tunnel wash (14, 38 and 86h). Our findings showed that the runoff water was highly polluted, but most of the contaminants were associated with particles which are normally considered biologically inert. In addition, high concentrations of calcium and dissolved organic carbon were identified in the wash water, thus reducing metal toxicity. However, compared to the control fish, a rapid accumulation of trace metals in gills was observed. This was immediately followed by a modest change in blood ions and glucose in exposed fish shortly after the exposure start. However, after 38-86h post wash, gill metal concentrations, plasma ions and glucose levels recovered back to control levels. In contrast, the mRNA transcription of the CYP1A and the oxidative stress related biomarkers TRX and GCS did not increase until 14h after the exposure start and this increase was still apparent when the experiment was terminated 86h after the beginning of the tunnel wash. The triggering of the defence systems seemed to have successfully restored homeostasis of the physiological variables measured, but the fish still used energy for detoxification four days after the episode, measured as increased biomarker synthesis. PMID:20381128

Meland, Sondre; Heier, Lene Sørlie; Salbu, Brit; Tollefsen, Knut Erik; Farmen, Eivind; Rosseland, Bjørn Olav

2010-06-01

375

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

376

Adsorption of Cd(II) and Cu(II) from aqueous solution by carbonate hydroxylapatite derived from eggshell waste.  

PubMed

Carbonate hydroxylapatite (CHAP) synthesized by using eggshell waste as raw material has been investigated as metal adsorption for Cd(II) and Cu(II) from aqueous solutions. The effect of various parameters on adsorption process such as contact time, solution pH, amount of CHAP and initial concentration of metal ions was studied at room temperature to optimize the conditions for maximum adsorption. The results showed that the removal efficiency of Cd(II) and Cu(II) by CHAP could reach 94 and 93.17%, respectively, when the initial Cd(II) concentration 80 mg/L and Cu(II) 60 mg/L and the liquid/solid ratio was 2.5 g/L. The equilibrium sorption data for single metal systems at room temperature could be described by the Langmuir and Freundlich isotherm models. The highest value of Langmuir maximum uptake, (b), was found for cadmium (111.1mg/g) and copper (142.86 mg/g). Similar Freundlich empirical constants, K, were obtained for cadmium (2.224) and copper (7.925). Ion exchange and surface adsorption might be involved in the adsorption process of cadmium and copper. Desorption experiments showed that CaCl2, NaCl, acetic acid and ultrasonic were not efficient enough to desorb substantial amount of metal ions from the CHAP. The results obtained show that CHAP has a high affinity to cadmium and copper. PMID:17368932

Zheng, Wei; Li, Xiao-ming; Yang, Qi; Zeng, Guang-ming; Shen, Xiang-xin; Zhang, Ying; Liu, Jing-jin

2007-08-17

377

Removal of sulfa drugs by sewage treatment in aqueous solution systems: activated carbon treatment and ozone oxidation.  

PubMed

This study investigates the activated carbon (AC) treatment and ozone oxidation of the sulfa drugs--sulfamethoxazole (SMX), sulfamonomethoxine (SMM), sulfadimidine (SDD), and sulfadimethoxine (SDM)--in aqueous solution systems. Three AC samples were prepared from Shirasagi (AC1 and AC2) and coal (AC3), and the surface functional groups, solution pH, specific surface areas, pore volumes, and morphologies of the three samples were evaluated. The specific surface areas were in the following order: AC1 (1391 m²/g) > AC2 (1053 m²/g) > AC3 (807 m²/g). The pore volume and mean pore diameter of AC3 were greater than those of AC1 and AC2. The concentration of sulfa drugs adsorbed onto the AC samples reached equilibrium within 150 h. Experimental data of the adsorption rate were fitted to a pseudo-second-order model. The amount of sulfa drugs adsorbed onto the AC samples was in the order of SDM < SMM < SDD < SMX; the mechanism of adsorption of the sulfa drugs onto the AC samples depended on the hydrophobicity of the AC surface. The adsorption isotherm data were fitted to Freundlich and Langmuir models. Ozone was generated from oxygen gas using an A-27 ozone generator, and the complete degradation of the sulfa drugs by ozone treatment at 60 mL/min was achieved within 50 min. Ozone treatment caused the structure of the sulfa drugs to decompose via ozone oxidation. PMID:22450123

Ogata, Fumihiko; Tominaga, Hisato; Kangawa, Moe; Inoue, Kenji; Kawasaki, Naohito

2012-01-01

378

Competitive biosorption of ortho-cresol, phenol, chlorophenol and chromium(VI) from aqueous solution by a bacterial biofilm supported on granular activated carbon  

Microsoft Academic Search

A biofilm of Arthrobacter viscosus supported on granular activated carbon was used to remove chromium and organic compounds (chlorophenol, phenol and o-cresol) from aqueous solutions. The compounds were studied as single solutes and in different combinations between them and Cr(VI). Optimum Cr(VI) adsorption was observed at a phenol concentration of 100mg\\/l and at an initial concentration of the metal of

C. Quintelas; E. Sousa; F. Silva; S. Neto; T. Tavares

2006-01-01

379

Hand washing frequencies and procedures used in retail food services.  

PubMed

Transmission of viruses, bacteria, and parasites to food by way of improperly washed hands is a major contributing factor in the spread of foodborne illnesses. Field observers have assessed compliance with hand washing regulations, yet few studies have included consideration of frequency and methods used by sectors of the food service industry or have included benchmarks for hand washing. Five 3-h observation periods of employee (n = 80) hand washing behaviors during menu production, service, and cleaning were conducted in 16 food service operations for a total of 240 h of direct observation. Four operations from each of four sectors of the retail food service industry participated in the study: assisted living for the elderly, childcare, restaurants, and schools. A validated observation form, based on 2005 Food Code guidelines, was used by two trained researchers. Researchers noted when hands should have been washed, when hands were washed, and how hands were washed. Overall compliance with Food Code recommendations for frequency during production, service, and cleaning phases ranged from 5% in restaurants to 33% in assisted living facilities. Procedural compliance rates also were low. Proposed benchmarks for the number of times hand washing should occur by each employee for each sector of food service during each phase of operation are seven times per hour for assisted living, nine times per hour for childcare, 29 times per hour for restaurants, and 11 times per hour for schools. These benchmarks are high, especially for restaurant employees. Implementation would mean lost productivity and potential for dermatitis; thus, active managerial control over work assignments is needed. These benchmarks can be used for training and to guide employee hand washing behaviors. PMID:18724759

Strohbehn, Catherine; Sneed, Jeannie; Paez, Paola; Meyer, Janell

2008-08-01

380

Correlation of mineralogy and trace element leaching behavior in modified in situ spent shales from Logan Wash, Colorado  

SciTech Connect

Oil shale retorting induces mineral and chemical reactions to occur on the macroscopic and microscopic levels in the kerogen-bearing marlstone. The nature and extent of the reactions is dependent upon process variables such as maximum temperature, time at temperature, atmosphere, and raw shale composition. This report describes the investigation of the mineral, chemical, and trace element release properties of spent shales retrieved from an experimental in situ retort at Occidental Oil Shale, Inc.'s Logan Wash site in Garfield County, Colorado. Correlation between mineralogy of the spent materials and the mobility of major, minor, and trace elements are indicated, and relationships with important process parameters are discussed. The progress of carbonate decomposition reactions and silication reactions is indicative of the processing conditions experienced by the shale materials and influences the mobility of major, minor, and trace elements when the solids are contacted by water. Shale minerals that are exposed to the extreme conditions reached in underground retorting form high temperature product phases including akermanite-gehlenite and diopside-augite solid solutions, kalsilite, monticellite, and forsterie. The persistence of relatively thermally stable phases, such as quartz, orthoclase, and albite provide insight into the extremes of processing conditions experienced by the spent shales. Leachate compositions suggest that several trace elements, including vanadium, boron, fluoride, and arsenic are not rendered immobile by the formation of the high-temperature silicate product phase akermanite-gehlenite.

Peterson, E.J.; O'Rourke, J.A.; Wagner, P.

1981-01-01

381

Remediation of toxic metal contaminated soil by washing with biodegradable aminopolycarboxylate chelants.  

PubMed

Ex situ soil washing with synthetic extractants such as, aminopolycarboxylate chelants (APCs) is a viable treatment alternative for metal-contaminated site remediation. EDTA and its homologs are widely used among the APCs in the ex situ soil washing processes. These APCs are merely biodegradable and highly persistent in the aquatic environments leading to the post-use toxic effects. Therefore, an increasing interest is focused on the development and use of the eco-friendly APCs having better biodegradability and less environmental toxicity. The paper deals with the results from the lab-scale washing treatments of a real sample of metal-contaminated soil for the removal of the ecotoxic metal ions (Cd, Cu, Ni, Pb, and Zn) using five biodegradable APCs, namely [S,S]-ethylenediaminedisuccinic acid, imminodisuccinic acid, methylglycinediacetic acid, DL-2-(2-carboxymethyl) nitrilotriacetic acid (GLDA), and 3-hydroxy-2,2'-iminodisuccinic acid. The performance of those biodegradable APCs was evaluated for their interaction with the soil mineral constituents in terms of the solution pH and metal-chelant stability constants, and compared with that of EDTA. Speciation calculations were performed to identify the optimal conditions for the washing process in terms of the metal-chelant interactions as well as to understand the selectivity in the separation ability of the biodegradable chelants towards the metal ions. A linear relationship between the metal extraction capacity of the individual chelants towards each of the metal ions from the soil matrix and metal-chelant conditional stability constants for a solution pH greater than 6 was observed. Additional considerations were derived from the behavior of the major potentially interfering cations (Al, Ca, Fe, Mg, and Mn), and it was hypothesized that use of an excess of chelant may minimize the possible competition effects during the single-step washing treatments. Sequential extraction procedure was used to determine the metal distribution in the soil before and after the extractive decontamination using biodegradable APCs, and the capability of the APCs in removing the metal ions even from the theoretically immobilized fraction of the contaminated soil was observed. GLDA appeared to possess the greatest potential to decontaminate the soil through ex situ washing treatment compared to the other biodegradable chelants used in the study. PMID:22391046

Begum, Zinnat A; Rahman, Ismail M M; Tate, Yousuke; Sawai, Hikaru; Maki, Teruya; Hasegawa, Hiroshi

2012-06-01

382

Endotoxins in cotton: washing effects and size distribution  

SciTech Connect

Endotoxin contamination was measured in washed and unwashed cottons from three distinct growing areas, California, Mississippi, and Texas. The data show differences in endotoxin contamination based upon the geographic source of the cotton. It is also shown that washing bulk cotton before the carding process results in lower endotoxin in the cotton dust. Washing conditions can affect the endotoxin levels, and all size fractions of the airborne dust contain quantifiable endotoxin contamination. Endotoxin analyses provide a simple and reliable method for monitoring the cleanliness of cotton or airborne cotton dusts.

Olenchock, S.A.; Mull, J.C.; Jones, W.G.

1983-01-01

383

PLUTONIUM MOBILIZATION AND MATRIX DISSOLUTION DURING EXPERIMENTAL SLUDGE WASHING OF BISMUTH PHOSPHATE, REDOX, AND PUREX WASTE SIMULANTS  

Microsoft Academic Search

Consecutive washing of simulant sludges from the BiPO4 (Cycle 3), Redox, and PUREX processes shows less than 4.5% of sorbed Pu(III\\/IV) or Pu(VI) is mobilized during CrO4 dissolution by the 0.01 M NaOH + 0.01 M NaNO2 sluice or 3.0 M NaOH leach solutions to be used for sludge pretreatment at Hanford. Experimental sludge washing with 2.0 M HNO3 results

Andrew H. Bond; Kenneth L. Nash; Artem V. Gelis; James C. Sullivan; Mark P. Jensen; Linfeng Rao

2001-01-01

384

Carbon-deposited TiO2 3D inverse opal photocatalysts: visible-light photocatalytic activity and enhanced activity in a viscous solution.  

PubMed

We for the first time demonstrated carbon-deposited TiO2 inverse opal (C-TiO2 IO) structures as highly efficient visible photocatalysts. The carbon deposition proceeded via high-temperature pyrolysis of phloroglucinol/formaldehyde resol, which had been coated onto the TiO2 IO structures. Carbon deposition formed a carbon layer and doped the TiO2 interface, which synergistically enhanced visible-light absorption. We directly measured the visible-light photocatalytic activity by constructing solar cells comprising the C-TiO2 IO electrode. Photocatalytic degradation of organic dyes in a solution was also evaluated. Photocatalytic dye degradation under visible light was only observed in the presence of the C-TiO2 IO sample and was increased with the content of carbon deposition. The IO structures could be readily decorated with TiO2 nanoparticles to increase the surface area and enhance the photocatalytic activity. Notably, the photocatalytic reaction was found to proceed in a viscous polymeric solution. A comparison of the mesoporous TiO2 structure and the IO TiO2 structure revealed that the latter performed better as the solution viscosity increased. This result was attributed to facile diffusion into the fully connected and low-tortuosity macropore network of the IO structure. PMID:24266769

Lee, Sunbok; Lee, Youngshin; Kim, Dong Ha; Moon, Jun Hyuk

2013-12-11

385

Control of helminth contamination of raw vegetables by washing.  

PubMed

This study was conducted to determine the control of helminth egg contamination of raw vegetables by washing. A total of 199 unwashed and 199 washed lettuce, parsley, carrots, dill, rocket, and green-peppers, provided by a catering service in Bursa, Turkey, between March and June 2009, were subjected to helminth egg count under light microscopy. Helminth eggs were detected in six (3.0%) unwashed samples and not in any washed samples (p<0.01). Ascaris lumbricoides and Toxocara spp. were detected in four (2.0%) and two (1.0%) unwashed vegetables, respectively, mostly among leafy vegetables such as lettuce and parsley. Our data confirm that washing procedures before consumption of raw vegetables regardless of the providers' sanitation should be performed to avoid transmission of helminths. PMID:20569015

Avcio?lu, Hamza; Soykan, Emel; Tarakci, Umit

2011-02-01

386

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...

387

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

388

Documentation of a decision framework to support enhanced sludge washing  

SciTech Connect

This document describes a proposed decision model that, if developed to its fullest, can provide a wide range of analysis options and insights to pretreatment/sludge washing alternatives. A recent decision has been made to terminate this work

Brothers, A.J.

1995-12-31

389

37. Photocopy of ink and wash rendering by N. G. ...  

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

37. Photocopy of ink and wash rendering by N. G. Starkwether in collection of Mr. & Mrs. Richard T. Pratt, Camden SIDE ELEVATION OF ITALIAN VILLA FOR W. C. PRATT, ESQr - Camden, Rappahannock River, Port Royal, Caroline County, VA

390

33 CFR 162.230 - Columbia River, Wash.  

...Columbia River, Wash. (a) Grand Coulee Dam discharge channel; restricted area— ...of the Columbia River between Grand Coulee Dam (situated at river mile 596.6) and river...S. Department of the Interior, Coulee Dam,...

2014-07-01

391

SOIL WASHING TREATABILITY TESTS FOR PESTICIDE- CONTAMINATED SOIL  

EPA Science Inventory

The 1987 Sand Creek Operable Unit 5 record of decision (ROD) identified soil washing as the selected technology to remediate soils contaminated with high levels of organochlorine pesticides, herbicides, and metals. Initial treatability tests conducted to assess the applicability...

392

21 CFR 133.137 - Washed curd cheese for manufacturing.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Washed curd cheese for manufacturing. 133.137 Section 133.137...SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific...

2010-04-01

393

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

394

[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

395

Environmentally benign formation of polymeric microspheres by rapid expansion of supercritical carbon dioxide solution with a nonsolvent.  

PubMed

A novel method is reported for forming polymer microparticles, which reduce atmospheric emissions of environmentally harmful volatile organic compounds such as toluene and xylene used as paint solvent in paint industry. The polymer microparticles have formed through rapid expansion from supercritical solution with a nonsolvent (RESS-N). Solubilization of poly(styrene)-b-(poly(methyl methacrylate)-co-poly (glycidyl methacrylate)) copolymer(PS-b-(PMMA-co-PGMA), MW = 5000, PS/PMMA/PGMA = 2/5/3), poly(ethylene glycol) (PEG, M. W = 4000), bisphenol A type epoxy resin (EP, MW = 3000), poly(methyl methacrylate) (PMMA; MW = 15000, 75000, 120000), and poly(oxyalkylene) alkylphenyl ether (MW = 4000) in carbon dioxide (CO2) was achieved with the use of small alcohols as cosolvents. The solubility of the PS-b-(PMMA-co-PGMA) is extremely low in either CO2 or ethanol but becomes 20 wt % in a mixture of the two. Because ethanol is a nonsolvent for the polymer, it can be used as a cosolvent in rapid expansion from supercritical solution to produce 1-3 microm particles that do not agglomerate. Obtained polymer particles by RESS-N were applied as powder coatings. The resulting coatings have a smooth and coherent film. The particle size distribution of microspheres was controlled by changing the polymer concentration, preexpansion pressure, temperature, and injection distance. The feed compositions were more effective than the other factors in controlling the particle size. The polymeric microparticles formed by RESS-N method can be utilized to make the thin coating film without anytoxic organic solvents and/or surfactants. PMID:11686380

Matsuyama, K; Mishima, K; Umemoto, H; Yamaguchi, S

2001-10-15

396

Magnetic carbon nanotubes synthesis by Fenton's reagent method and their potential application for removal of azo dye from aqueous solution.  

PubMed

We report a simple and easy method to fabricate magnetic carbon nanotubes (CNTs) by Fenton's reagent method without the addition of any cations. H(2)O(2) was added slowly into the FeSO(4) solution mixed with purified CNTs, and the resulting reactants were placed into a quartz tube to undergo heat treatment under a nitrogen/hydrogen flow. Iron oxide (Fe(2)O(3)) nanoparticles were uniformly dispersed on CNTs without any pretreatment such as strong acid or covalent functionalization processes. The as-produced magnetic CNTs were used as an adsorbent for removal of methyl orange (MO) dye from aqueous solutions. Adsorption experiments indicated that the magnetic CNTs have good adsorption capacity (q(e)) of MO (28 mg/g). The Freundlich isotherm model fitted the experiment data better than the Langmuir isotherm mode. The mean energy of adsorption was calculated as 3.72 kJ/mol based on the Dubinin-Radushkevich model, which suggests that the removal process was dominated by physical adsorption. Kinetic regression results showed that the adsorption kinetics was more accurately represented by a pseudo second-order model. Intra-particle diffusion was involved in the adsorption process, but it was not the only rate-controlling step. More importantly, a new photocatalytic regeneration technology can be enabled by the high nanoscale iron oxide loading (50%). The magnetic CNT adsorbents could be effectively and quickly separated by applying an external magnetic field and regenerated by UV photocatalysis. Therefore, CNTs/?-Fe(2)O(3) hybrid is a promising magnetic nanomaterial for preconcentration and separation of organic pollutants for environmental remediation. PMID:22564767

Yu, Fei; Chen, Junhong; Chen, Lu; Huai, Jing; Gong, Wenyi; Yuan, Zhiwen; Wang, Jinhe; Ma, Jie

2012-07-15

397

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

398

Process for the selective extraction treatment of gaseous hydrocarbon mixture containing carbon dioxide  

SciTech Connect

The present invention relates to a process for the selective extraction treatment of a gaseous hydrocarbon mixture containing 5 to 3000 ppm (parts per million) by volume of hydrogen sulfide and 0.3 to 3% carbon dioxide, in order to obtain a purified gas containing less than 4 ppm by volume hydrogen sulfide and less than 2% carbon dioxide. The gaseous hydrocarbon mixture is submitted to a series of counter-current washings by contact with a tertiary amine aqueous solution in an absorption zone from which is drawn a liquid effluent enriched in hydrogen sulfide.

Blanc, C.; Elgue, J.; Galy, H.

1983-10-04

399

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

400

Kinetics and thermodynamics of the sorption of furaltadone from aqueous solutions on magnetic multi-walled carbon nanotubes.  

PubMed

Magnetic multi-wall carbon nanotubes (M-MWCNTs) were used as an adsorbent for removal of furaltadone from aqueous solutions, and the adsorption behaviors were investigated by varying pH, sorbent amount, sorption time and temperature. The results showed that the adsorption efficiency of furaltadone reached 97% when the dosage of M-MWCNT was 0.45 g · L?¹, the pH was 7 and the adsorption time was 150 min. The kinetic data showed that the pseudo-second-order model can fit the adsorption kinetics. The sorption data could be well explained by the Langmuir model under different temperatures. The adsorption process was influenced by both intraparticle diffusion and external mass transfer. The experimental data analysis indicated that the electrostatic attraction and ?-? stacking interactions between M-MWCNT and furaltadone might be the adsorption mechanism. Thermodynamic analysis reflected that adsorption of furaltadone on the M-MWCNT was spontaneous and exothermic. Our study showed that M-MWCNTs can be used as a potential adsorbent for removal of furaltadone from water and wastewater. PMID:25259483

Chen, Xu; Xiong, Zhen-hu

2014-01-01

401

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

402

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

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

403

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

404

Spectroscopic investigations of nanoporous SiO 2 impregnated with Ag ?-diketonates from supercritical solution of carbon dioxide  

NASA Astrophysics Data System (ADS)

Porous materials based on SiO 2 containing nanoparticles of silver (NP Ag) are perspective objects for different medico-biological and optoelectronic applications. In the present work nanoporous glasses Vycor (pore size ˜4 nm) and synthetic opal matrices (OM, void size ˜40 nm) impregnated with ?-diketonates of silver (Ag(hfac)COD) via solution of supercritical carbon dioxide were studied. Paramagnetic molecules Cu(hfac) 2 were used as spectroscopic probes permitting to obtain the information about the incorporation of similar organometallic molecules into these matrices. Spectra of absorption and electronic paramagnetic resonance (EPR) in the samples of porous SiO 2 containing Ag(hfac)COD were studied before and after heat treatment in air atmosphere. In both materials impregnated at temperature above 50 °C the absorption band at 420-430 nm (the plasmon resonance (PR) band)) typical for nanoparticles of metallic Ag is observed. This band increases in the intensity at heat treatment or at an increase in temperature of impregnation processing. Features of the formation of the PR band in each case depends on sizes and shape of voids in the samples as well as on conditions of heat treatment. The states of paramagnetic centers formed after Ag(hfac)COD introduction are analyzed.

Rybaltovskii, A. O.; Bogomolova, L. D.; Jachkin, V. A.; Minaev, N. V.; Samoilovich, M. I.; Tsvetkov, M. Yu.; Tarasova, V. V.; Bagratashvili, V. N.

2011-11-01

405

Continuous solid solution of {kappa}-phase in the third period transition metals-aluminum-carbon pseudo-ternary systems  

SciTech Connect

Phase stability of {kappa}-phases (perovskite-type phases) was studied in the third-period transition-metals (M: Mn to Cu) - aluminum (Al) - carbon (C) systems. The concentrations of transition metals (C{sub M}) were systematically changed from 60mol%Mn to 20mol%Ni+40mol%Cu along the periodic table under the constant nominal alloy compositions of C{sub M1}+C{sub M2} = 60mol%, C{sub Al} = 20mol% and C{sub C} = 20mol%. Alloys were prepared using mechanical alloying and hot pressing. Constituent phases were investigated by X-ray diffraction analysis, scanning electron microscopy and electron probe microanalysis. It is confirmed that Mn{sub 3}Al(C,O){sub 0.95}, Fe{sub 3}Al(C,O){sub 0.87}, Co{sub 3}Al(C,O){sub 0.6} and Ni{sub 3}Al(C,O){sub 0.26} exist in their ternary systems where oxygen is introduced during the process. Also, only one {kappa}-phase is recognized in an alloy having an intermediate composition in every system. This suggests that continuous solid solutions between these {kappa}-phases are formed in the pseudo-ternary systems. Composition dependence of lattice parameter is discussed.

Hosoda, Hideki; Suzuki, Kensyo; Hanada, Shuji

1999-07-01

406

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

407

Cross-flow filtration during the washing of a simulated radioactive waste stream  

SciTech Connect

Bechtel National, Inc. has been contracted by the Department of Energy to design a Waste Treatment and Immobilization Plant (WTP) to stabilize liquid radioactive waste that is stored at the Hanford Site as part of the River Protection Project (RPP). Because of its experience with radioactive waste stabilization, the Savannah River National Laboratory (SRNL) of the Westinghouse Savannah River Company is working with Bechtel and Washington Group International, to help design and test certain parts of the waste treatment facility. One part of the process is the separation of radioactive solids from the liquid wastes by cross-flow ultrafiltration. To test this process a cross-flow filter was used that was prototypic in porosity, length, and diameter, along with a simulated radioactive waste slurry, made to prototypically represent the chemical and physical characteristics of a Hanford waste in tank 241-AY-102/C-106. To mimic the filtration process the waste slurry undergoes several steps, including dewatering and washing. During dewatering the concentration of undissolved solids (UDS) of the simulated AY102/C106 waste is increased from 12 wt percent to at least 20 wt percent. Once at the higher concentration the waste must be washed to prepare for its eventual receipt in a High Level Radioactive Waste Melter to be vitrified. This paper describes the process of washing and filtering a batch of concentrated simulated waste in two cycles, which each containing 22 washing steps that used approximately 7.7 liters of a solution of 0.01 M NaOH per step. This will be the method used by the full-scale WTP to prepare the waste for vitrification. The first washing cycle started with the simulated waste that had a solids concentration of 20 wt percent UDS. This cycle began with a permeate filter flux of 0.015 gpm/ft2 (3.68 cm/hr) at 19.6 wt percent UDS with a density of 1.33 kg/L, and yield stress of 8.5 Pa. At the end of the 22 washing steps the permeate filter flux increased to 0. 023 gpm/ft2 (5.64 cm/hr) at 20.1 wt percent UDS with a density of 1.17 kg/L, and yield stress of 10.4 Pa. The average permeate filter flux during the 7 hours of Cycle 1 washing was 0.018 gpm/ft2 (4.41 cm/hr). During Cycle 2 the simulated waste started at a permeate filter flux of 0.025 gpm/ft2 (6.13 cm/hr). Note that the starting flux for Cycle 2 was greater than the ending flux for Cycle 1. The period between the cycles was approximately 12 hours. While no filtering occurred during that period either solids dissolution continued and/or the filter cake was dislodged somewhat with the stopping and starting of filter operation. At the end of the second set of 22 washing steps, the permeate filter flux increased to 0.032 gpm/ft2 (7.84 cm/hr) at 20.6 wt percent UDS with a density of 1.16 kg/L, and yield stress of 8.2 Pa. The average permeate filter flux during the 4 hours of Cycle 2 washing was 029 gpm/ft2 (7.11 cm/hr).

MARK R., DUIGNAN

2005-03-30

408

Use of alkali metal salts to prepare high purity single-walled carbon nanotube solutions and thin films  

NASA Astrophysics Data System (ADS)

Single-walled carbon nanotubes (SWCNTs) display interesting electronic and optical properties desired for many advanced thin film applications, such as transparent conductive electrodes or thin-film transistors. Large-scale production of SWCNTs generally results in polydispersed mixtures of nanotube structures. Since SWCNT electronic character (conducting or semiconducting nature) depends on the nanotube structure, application performance is being held back by this inability to discretely control SWCNT synthesis. Although a number of post-production techniques are able to separate SWCNTs based on electronic character, diameter, or chirality, most still suffer from the disadvantage of high costs of materials, equipment, or labor intensity to be relevant for large-scale production. On the other hand, chromatographic separation has emerged as a method that is compatible with large scale separation of metallic and semiconducting SWCNTs. In this work, SWCNTs, in an aqueous surfactant suspension of sodium dodecyl sulfate (SDS), are separated by their electronic character using a gel chromatography process. Metallic SWCNTs (m-SWCNTs) are collected as initial fractions since they show minimum interaction with the gel medium, whereas, semiconducting SWCNTs (sc- SWCNTs) remain adsorbed to the gel. The process of sc-SWCNT retention in the gel is found to be driven by the packing density of SDS around the SWCNTs. Through a series of separation experiments, it is shown that sc-SWCNTs can be eluted from the gel simply by disturbing the configuration of the SDS/SWCNT micellar structure. This is achieved by either introducing a solution containing a co-surfactant, such as sodium cholate (SC), or solutions of alkali metal ionic salts. Analysis of SWCNT suspensions by optical absorption provides insights into the effect of changing the metal ion (M+ = Li+, Na+, and K+) in the eluting solution. Salts with smaller metal ions (e.g. Li+) require higher concentrations to achieve separation. By using salts with different anionic groups (cholate, Cl-, I-, and SCN-), it is concluded that the SWCNT separation using salt solutions is mainly driven by the cations in the solution. Additionally, different methods for depositing separated SWCNTs on glass substrates are described. In one method, SWCNTs are first isolated from their surfactant by introducing organic solvents such as methanol or acetone to aqueous suspensions of previously separated m- and/or sc-SWCNTs. Following the induced SWCNT dissolution, desired nanomaterials can be redispersed directly in another solvent, such as methanol, for deposition on substrates. In another method, separated SWCNTs are deposited on glass substrates by the process of evaporation driven self-assembly. Different morphologies on the substrate are formed by changing the viscosity of the evaporating SWCNT/SDS suspensions. The results are described using the Stokes-Einstein equation for diffusion in one dimension.

Ashour, Rakan F.

409

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

410

Utilization of Arachis hypogaea hull, an agricultural waste for the production of activated carbons to remove phenol from aqueous solutions  

Microsoft Academic Search

Arachis hypogaea hulls, an agricultural waste, were used to prepare activated carbon by chemical activation with zinc chloride under four different activation atmospheres. The most important parameter in chemical activation was found to be the chemical ratio (activating agent\\/precursor). Carbonization temperature and time are the other two important variables, which had significant effect on the pore structure of carbon. The

Kaustubha Mohanty; Debabrata Das; Manindra Nath Biswas

2008-01-01

411

Alternative solution model for the ternary carbonate system CaCO3 - MgCO3 - FeCO3 - I. A ternary Bragg-Williams ordering model  

USGS Publications Warehouse

The minerals of the ternary carbonate system CaCO3 - MgCO3 - FeCO3 represent a complex series of solid solutions and ordering states. An understanding of those complexities requires a solution model that can both duplicate the subsolidus phase relationships and generate correct values for the activities. Such a solution model must account for the changes in the total energy of the system resulting from a change in the ordering state of the individual constituents. Various ordering models have been applied to binary carbonate systems, but no attempts have previously been made to model the ordering in the ternary system. This study derives a new set of equations that allow for the equilibrium degree of order to be calculated for a system involving three cations mixing on two sites, as in the case of the ternary carbonates. The method is based on the Bragg-Williams approach. From the degree of order, the mole fractions of the three cations in each of the two sites can be determined. Once the site occupancies have been established, a Margules-type mixing model can be used to determine the free energy of mixing in the solid solution and therefore the activities of the various components. ?? 1993 Springer-Verlag.

McSwiggen, P.L.

1993-01-01

412

Virgibacillus olivae sp. nov., isolated from waste wash-water from processing of Spanish-style green olives  

Microsoft Academic Search

Four bacterial strains (E308 T ,E5549,I3077 andN30129) wereisolated from the residual wash-water produced during the processing of Spanish-style green table olives. The isolates were subjected to a polyphasic taxonomic study using phenotypic, phylogenetic and genotypic methods. The bacteria were Gram-positive, spore-forming rods. Moreover, they were heterotrophs that were able to utilize cellobiose, glucose, mannose and rhamnose as carbon sources. The

Teresa Quesada; Margarita Aguilera; JoseAntonio Morillo; Alberto Ramos-Cormenzana; Mercedes Monteoliva-Sanchez

2007-01-01

413

{sup 13}C and {sup 17}O NMR binding constant studies of uranyl carbonate complexes in near-neutral aqueous solution. Yucca Mountain Project Milestone Report 3351  

SciTech Connect

Valuable structural information, much of it unavailable by other methods, can be obtained about complexes in solution through NMR spectroscopy. From chemical shift and intensity measurements of complexed species, NMR can serve as a species-specific structural probe for molecules in solution and can be used to validate thermodynamic constants used in geochemical modeling. Fourier-transform nuclear magnetic resonance (FT-NMR) spectroscopy has been employed to study the speciation of uranium(VI) ions in aqueous carbonate solutions as a function of pH, ionic strength, carbonate concentration, uranium concentration, and temperature. Carbon-13 and oxygen-17 NMR spectroscopy were used to monitor the fractions, and hence thermodynamic binding constants of two different uranyl species U0{sub 2}(CO{sub 3}){sub 3}{sup 4{minus}} and (UO{sub 2}){sub 3}(CO{sub 3}){sub 6}{sup 6{minus}} in aqueous solution. Synthetic buffer solutions were prepared under the ionic strength conditions used in the NMR studies in order to obtain an accurate measure of the hydrogen ion concentration, and a discussion of pH = {minus}log(a{sub H}{sup +}) versus p[H] = {minus}log[H+] is provided. It is shown that for quantitative studies, the quantity p[H] needs to be used. Fourteen uranium(VI) binding constants recommended by the OECD NEA literature review were corrected to the ionic strengths employed in the NMR study using specific ion interaction theory (SIT), and the predicted species distributions were compared with the actual species observed by multinuclear NMR. Agreement between observed and predicted stability fields is excellent. This establishes the utility of multinuclear NMR as a species-specific tool for the study of the actinide carbonate complexation constants, and serves as a means for validating the recommendations provided by the OECD NEA.

Clark, D.L.; Newton, T.W.; Palmer, P.D.; Zwick, B.D.

1995-01-01

414

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

415

Carbon Efficient Building Solutions  

Microsoft Academic Search

Traditionally, the Finnish legislation have focused on energy use and especially on energy used for heating space in buildings. However, in many cases this does not lead to the optimal concept in respect to minimizing green house gases. This paper studies how CO2<\\/sub> emission levels are affected by different measures to reduce energy use in buildings. This paper presents two

Miimu Airaksinen; Pellervo Matilainen

2010-01-01

416

Reduction of Salmonella enterica contamination on grape tomatoes by washing with thyme oil, thymol, and carvacrol as compared with chlorine treatment.  

PubMed

In recent years, multistate outbreaks of Salmonella enterica serovars were traced to tomatoes and resulted in serious economic loss for the tomato industry and decreased consumer confidence in the safety of tomato produce. Purified compounds derived from essential oils such as thymol and carvacrol had wide inhibitory effects against foodborne pathogens including Salmonella. The objective of this study was to determine the antimicrobial activities of thymol, carvacrol, and thyme oil against Salmonella on grape tomatoes. Surface-inoculated grape tomatoes were washed with 4% ethanol, 200 ppm of chlorine, or one of six washing solutions (thymol [0.2 and 0.4 mg/ml], thyme oil [1 and 2 mg/ml], and carvacrol [0.2 and 0.4 mg/ml]) for 5 or 10 min. There was no significant difference in the reduction of S. enterica serovars when different washing times were used (P > 0.05). Thymol (especially at the concentration of 0.4 mg/ml) was the most effective (P < 0.05) among the three natural antimicrobial agents, which achieved >4.1-log reductions of S. enterica serovars Typhimurium, Kentucky, Senftenberg, and Enteritidis on grape tomatoes after a 5-min washing and >4.3-log reductions after a 10-min washing. A >4.6-log reduction in the S. enterica populations in comparison to control was observed with the use of thymol solutions. The uses of these antimicrobial agents achieved significant log reductions of Salmonella on inoculated grape tomatoes and decreased dramatically the risk of potential transmission of pathogens from tomatoes to washing solutions. None of these antimicrobial agents decreased the total phenolic and ascorbic acid content, nor did any of them change the color and pH values or affect the taste, aroma, or visual quality of grape tomatoes. Therefore, 0.4 mg/ml thymol has great potential to be an alternative to chlorine-based washing solution for fresh produce. PMID:21219747

Lu, Yingjian; Wu, Changqing

2010-12-01

417

Treatment of tunnel wash water and implications for its disposal.  

PubMed

The use of road tunnels in urban areas creates water pollution problems, since the tunnels must be frequently cleaned for traffic safety reasons. The washing generates extensive volumes of highly polluted water, for example, more than fivefold higher concentrations of suspended solids compared to highway runoff. The pollutants in the wash water have an affinity for particulate material, so sedimentation should be a viable treatment option. In this study, 12 in situ sedimentation trials were carried out on tunnel wash water, with and without addition of chemical flocculent. Initial suspended solids concentration ranged from 804 to 9,690 mg/L. With sedimentation times of less than 24 hours and use of a chemical flocculent, it was possible to reach low concentrations of suspended solids (<15 mg/L), PAH (<0.1 ?g/L), As (<1.0 ?g/L), Cd (<0.05 ?g/L), Hg (<0.02 ?g/L), Fe (<200 ?g/L), Ni (<8 ?g/L), Pb (<0.5 ?g/L), Zn (<60 ?g/L) and Cr (<8 ?g/L). Acute Microtox(®) toxicity, mainly attributed to detergents used for the tunnel wash, decreased significantly at low suspended solids concentrations after sedimentation using a flocculent. The tunnel wash water did not inhibit nitrification. The treated water should be suitable for discharge into recipient waters or a wastewater treatment plant. PMID:24845317

Hallberg, M; Renman, G; Byman, L; Svenstam, G; Norling, M

2014-01-01

418

Removal of mercury(II) from aqueous solutions and chlor-alkali industry effluent by steam activated and sulphurised activated carbons prepared from bagasse pith: kinetics and equilibrium studies  

Microsoft Academic Search

The adsorption of mercury from aqueous solutions and chlor-alkali industry effluent on steam activated and sulphurised steam activated carbons prepared from bagasse pith have been studied comparatively. The uptake of mercury(II) (Hg(II)) was maximum by steam activated carbon in presence of SO2 and H2S (SA–SO2–H2S–C) followed by steam activated carbon in presence of SO2 (SA–SO2–C), steam activated carbon in presence

K. Anoop Krishnan; T. S. Anirudhan

2002-01-01

419

Selective and sensitive electrochemical detection of glucose in neutral solution using platinum-lead alloy nanoparticle/carbon nanotube nanocomposites.  

PubMed

Electrodeposition of Pt-Pb nanoparticles (PtPbNPs) to multi-walled carbon nanotubes (MWCNTs) resulted in a stable PtPbNP/MWCNT nanocomposite with high electrocatalytic activity to glucose oxidation in either neutral or alkaline medium. More importantly, the nanocomposite electrode with a slight modification exhibited high sensitivity, high selectivity, and low detection limit in amperometric glucose sensing at physiological neutral pH (poised at a negative potential). At +0.30 V in neutral solution, the nanocomposite electrode exhibited linearity up to 11 mM of glucose with a sensitivity of 17.8 microA cm(-2) mM(-1) and a detection limit of 1.8 microM (S/N=3). Electroactive ascorbic acid (0.1 mM), uric acid (0.1 mM) and fructose (0.3 mM) invoked only 23%, 14% and 9%, respectively, of the current response obtained for 3 mM glucose. At -0.15 V in neutral solution, the electrode responded linearly to glucose up to 5 mM with a detection limit of 0.16 mM (S/N=3) and detection sensitivity of approximately 18 microA cm(-2) mM(-1). At this negative potential, ascorbic acid, uric acid, and fructose were not electroactive, therefore, not interfering with glucose sensing. Modification of the nanocomposite electrode with Nafion coating followed by electrodeposition of a second layer of PtPbNPs on the Nafion coated PtPbNP/MWCNT nanocomposite produced a glucose sensor (poised at -0.15 V) with a lower detection limit (7.0 microM at S/N=3) and comparable sensitivity, selectivity and linearity compared to the PtPbNP/MWCNT nanocomposite. The Nafion coating lowered the detection limit by reducing the background noise, while the second layer of PtPbNPs restored the sensitivity to the level before Nafion coating. PMID:17586112

Cui, Hui-Fang; Ye, Jian-Shan; Zhang, Wei-De; Li, Chang-Ming; Luong, John H T; Sheu, Fwu-Shan

2007-07-01

420

Southwestern Willow Flycatcher Surveys Along the Las Vegas Wash, Clark County, Nevada, 2012.  

National Technical Information Service (NTIS)

The Las Vegas Wash Coordination Committee, a 29-member stakeholder group, is working to stabilize and enhance the Las Vegas Wash (Wash), the channel that drains flows from the Las Vegas Valley to Lake Mead at Las Vegas Bay. The Wash also flows through the...

D. Van Dooremolen

2012-01-01

421

Southwestern Willow Flycatcher Surveys Along the Las Vegas Wash, Clark County, Nevada, 2013.  

National Technical Information Service (NTIS)

The Las Vegas Wash Coordination Committee (LVWCC), a 29-member stakeholder group, is working to stabilize and enhance the Las Vegas Wash (Wash), the channel that drains flows from the Las Vegas Valley to Lake Mead at Las Vegas Bay. The Wash also flows thr...

D. Van Dooremolen

2014-01-01

422

Regenerable granular carbon nanotubes/alumina hybrid adsorbents for diclofenac sodium and carbamazepine removal from aqueous solution.  

PubMed

A novel granular carbon nanotubes (CNTs)/alumina (Al2O3) hybrid adsorbent with good sorption and regeneration properties was successfully prepared by mixing CNTs with surfactant Brij 35 and pseudo boehmite, followed by calcining to remove surfactant and form porous granules. Alumina binder increased the mechanical strength, hydrophilicity and porosity of the granular adsorbent, while the dispersed CNTs in the granular adsorbent were responsible for the sorption of diclofenac sodium (DS) and carbamazepine (CBZ). Scanning electron microscopy (SEM) showed that the CNTs and Al2O3 were mixed well and the porous structure was formed in the granular adsorbent. The high surface area and appropriate pore size of granular CNTs/Al2O3 adsorbent were favorable for sorption. The sorption of DS decreased with increasing solution pH, while pH had little effect on CBZ sorption. The maximum sorption capacities of CBZ and DS on the CNTs/Al2O3 adsorbent were 157.4 and 106.5 ?mol/g according to the Langmuir fitting. Moreover, the spent CNTs/Al2O3 adsorbent can be thermally regenerated at 400 °C in air due to the thermal stability of CNTs. The removal of CBZ and DS changed a little in the initial reuse cycles and then kept relatively constant until tenth cycles. The adsorbed CBZ and DS were decomposed in the regeneration process. This regenerable adsorbent may find potential application in water or wastewater treatment for the removal of some micropollutants such as pharmaceuticals. PMID:23579087

Wei, Haoran; Deng, Shubo; Huang, Qian; Nie, Yao; Wang, Bin; Huang, Jun; Yu, Gang

2013-08-01

423

Fluoroethylene carbonate as an important component in electrolyte solutions for high-voltage lithium batteries: role of surface chemistry on the cathode.  

PubMed

The effect of fluorinated ethylene carbonate (FEC) as a cosolvent in alkyl carbonates/LiPF6 on the cycling performance of high-voltage (5 V) cathodes for Li-ion batteries was investigated using electrochemical tools, X-ray photoelectron spectroscopy (XPS), and high-resolution scanning electron microscopy (HRSEM). An excellent cycling stability of LiCoPO4/Li, LiNi0.5Mn1.5O4/Si, and LiCoPO4/Si cells and a reasonable cycling of LiCoPO4/Si cells was achieved by replacing the commonly used cosolvent ethylene carbonate (EC) by FEC in electrolyte solutions for high-voltage Li-ion batteries. The roles of FEC in the improvement of the cycling performance of high-voltage Li-ion cells and of surface chemistry on the cathode are discussed. PMID:24885475

Markevich, Elena; Salitra, Gregory; Fridman, Katia; Sharabi, Ronit; Gershinsky, Gregory; Garsuch, Arnd; Semrau, Guenter; Schmidt, Michael A; Aurbach, Doron

2014-07-01

424

Kinetics of carbon dioxide absorption and desorption in aqueous alkanolamine solutions using a novel hemispherical contactor—I. Experimental apparatus and mathematical modeling  

Microsoft Academic Search

This two-parts paper summarizes the experimental and theoretical results of a comprehensive and first of its kind study on the kinetics of carbon dioxide (CO2) absorption and desorption in and from aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), methyl-diethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) and their mixtures (i.e., MEA+AMP, MEA+MDEA, DEA+AMP and DEA+MDEA). Part-1 of this paper presents a detailed design

Aqil Jamal; Axel Meisen; C. Jim Lim

2006-01-01

425

Generation of hydroxyl radical in aqueous solution by microwave energy using activated carbon as catalyst and its potential in removal of persistent organic substances  

Microsoft Academic Search

Salicylic acid (SA, hydroxybenzoic acid) was used as molecular probe to determine hydroxyl radical (OH) in aqueous solutions, where microwave (MW) radiation was involved and activated carbon (AC) existed. Rapid reaction of OH with SA produced a stable fluorescence product, 2,3-dihydroxybenzoic acid (2,3-DHBA) as well as its homologue, 2,5-DHBA, which were determined by HPLC. Dose of AC, air supply, and

Xie Quan; Yaobin Zhang; Shuo Chen; Yazhi Zhao; Fenglin Yang

2007-01-01

426

Adsorption of Cd(II) ions from aqueous solutions using activated carbon prepared from olive stone by ZnCl 2 activation  

Microsoft Academic Search

This study is aimed to remove Cd(II) ions from aqueous solutions by adsorption. As adsorbent, activated carbon prepared from olive stone, an agricultural solid by-product was used. Different activating agent (ZnCl2) amounts and adsorbent particle size were studied to optimize adsorbent surface area. The adsorption experiments were conducted at different parameters such as, adsorbent dose, temperature, equilibrium time and pH.

Ibrahim Kula; Mehmet U?urlu; Hamdi Karao?lu; Ali Çelik

2008-01-01

427

Electrochemical behavior of current collectors for lithium batteries in non-aqueous alkyl carbonate solution and surface analysis by ToF-SIMS  

Microsoft Academic Search

Several metals (Cu, Fe, Al, Ti, and Cr) as current collector for lithium-ion battery were investigated to understand their electrochemical behavior and passivation process in a non-aqueous alkyl carbonate solution containing LiPF6 salt. From cyclic voltammetric study, it was found that Cu and Fe metals were dissolved into the electrolyte below 4V vs. Li\\/Li+. Alternatively, Al and Ti were stable

Seung-Taek Myung; Yusuke Sasaki; Shuhei Sakurada; Yang-Kook Sun; Hitoshi Yashiro

2009-01-01

428

Metastable one-dimensional AgCl(1)-(x)I(x) solid-solution wurzite "tunnel" crystals formed within single-walled carbon nanotubes.  

PubMed

High-resolution transmission electron microscopy and spatially resolved electron loss spectroscopy have revealed that a eutectic mixture of AgCl and AgI crystallizes within single walled carbon nanotubes (SWNTs) as metastable AgCl(1-)(x)I(x) 1D solid solution crystals. The incorporated halide crystals form wurzite "tunnel" structures with locally varying Cl:I ratios and reduced Ag coordination. PMID:11878956

Sloan, Jeremy; Terrones, Mauricio; Nufer, Stefan; Friedrichs, Steffi; Bailey, Sam R; Woo, Hee-Gweon; Rühle, Manfred; Hutchison, John L; Green, Malcolm L H

2002-03-13

429

Facile preparation of magnetic separable powdered-activated-carbon\\/Ni adsorbent and its application in removal of perfluorooctane sulfonate (PFOS) from aqueous solution  

Microsoft Academic Search

The main aim of this study was to synthesize magnetic separable Nickel\\/powdered activated carbon (Ni\\/PAC) and its application as an adsorbent for removal of PFOS from aqueous solution. In this work, the synthesized adsorbent using simple method was characterized by using X-ray diffractionometer (XRD), surface area and pore size analyzer, vibrating sample magnetometer (VSM), and high resolution transmission electron microscope

Xuanqi Liang; Mohammed A. Gondal; Xiaofeng Chang; Zain H. Yamani; Nianwu Li; Hongling Lu; Guangbin Ji

2011-01-01

430

The adsorption of basic dye (Astrazon Blue FGRL) from aqueous solutions onto sepiolite, fly ash and apricot shell activated carbon: Kinetic and equilibrium studies  

Microsoft Academic Search

In this study, sepiolite, fly ash and apricot stone activated carbon (ASAC) were used as adsorbents for the investigation of the adsorption kinetics, isotherms and thermodynamic parameters of the basic dye (Astrazon Blue FGRL) from aqueous solutions at various concentrations (100–300mg\\/L), adsorbent doses (3–12g\\/L) and temperatures (303–323K). The result showed that the adsorption capacity of the dye increased with increasing

B. Karagozoglu; M. Tasdemir; E. Demirbas; M. Kobya

2007-01-01

431

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

432

BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTHEAST. THE ...  

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

BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTHEAST. THE ELECTRIC TROLLEY IS SEEN AT THE LEFT. THE BULKHEAD SEEN AT THE LOWER RIGHT IS NOT PART OF THE MACHINE; IT WAS INSTALLED TO RETAIN THE FILTER SAND AFTER THE MACHINE WAS NO LONGER USED. THE NORTHWEST CORNER OF SETTLING RESERVOIR NO. 4 IS SEEN IN THE DISTANCE BELOW THE RIGHT SIDE OF THE TROLLEY. - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

433

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

434

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

NASA Astrophysics Data System (ADS)

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.

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

2005-08-01

435

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