Sample records for carbonate wash solutions

  1. Electrolytic Recovery of Cadmium from Cyanide Washing Solutions on Filtering Carbon-Graphite Electrodes

    Microsoft Academic Search

    V. K. Varentsov

    2003-01-01

    Electrorecovery of cadmium(II) on filtering carbon-graphite electrodes from washing cyanide solutions formed in cadmium-plating of articles in a cyanide electrolyte was studied. The effect of the dilution factor of the supporting electrolyte on the run of cathodic polarization curves, pH value, and solution resistivity was analyzed. The influence exerted by the efficiency of cadmium(II) recovery on the carbon-graphite electrodes was

  2. Solvent wash solution

    DOEpatents

    Neace, James C. (Blackville, SC)

    1986-01-01

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

  3. Recovery of cadmium and change in properties of a fibrous carbon electrode in electrolytic processing of ammonia washing solutions formed in cadmium plating

    Microsoft Academic Search

    V. I. Varentsova; V. K. Varentsov

    2007-01-01

    The possibility of recovering cadmium deposited on fibrous carbon electrodes from ammonium washing solutions formed in cadmium\\u000a plating via operation of a short-circuited electrochemical system or anodic dissolution was examined. A polarization study\\u000a of electrode processes that occur on a renewable graphite microelectrode in ammonium solutions of varied composition was carried\\u000a out. The change in the properties of fibrous carbon

  4. 7 CFR 2902.51 - Parts wash solutions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  5. 7 CFR 2902.51 - Parts wash solutions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2011-01-01 false Parts wash solutions. 2902.51 Section 2902.51 Agriculture...Designated Items § 2902.51 Parts wash solutions. (a) Definition. Products...preference for qualifying biobased parts wash solutions. By that date, Federal agencies...

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

    SciTech Connect

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

    1995-12-31

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  8. Efficacy of wash solutions in recovering Cyclospora cayetanensis, Cryptosporidium parvum, and Toxoplasma gondii from basil.

    PubMed

    Chandra, Venessa; Torres, Maria; Ortega, Ynés R

    2014-08-01

    Parasitic diseases can be acquired by ingestion of contaminated raw or minimally processed fresh produce (herbs and fruits). The sensitivity of methods used to detect parasites on fresh produce depends in part on the efficacy of wash solutions in removing them from suspect samples. In this study, six wash solutions (sterile E-Pure water, 3% levulinic acid-3% sodium dodecyl sulfate, 1 M glycine, 0.1 M phosphate-buffered saline, 0.1% Alconox, and 1% HCl-pepsin) were evaluated for their effectiveness in removing Cyclospora cayetanensis, Cryptosporidium parvum, and Toxoplasma gondii from basil. One hundred or 1,000 oocysts of these parasites were inoculated onto the adaxial surfaces of 25 g of basil leaves, placed in stomacher bags, and stored for 1 h at 21°C or 24 h at 4°C. Leaves were hand washed in each wash solution for 1 min. DNA was extracted from the wash solutions and amplified using PCR for the detection of all parasites. Oocysts inoculated at a concentration of 1,000 oocysts per 25 g of basil were detected in all wash solutions. At an inoculum concentration of 100 oocysts per 25 g, oocysts were detected in 18.5 to 92.6% of the wash solutions. The lowest variability in recovering oocysts from basil inoculated with 100 oocysts was observed in 1% HCl-pepsin wash solution. Oocyst recovery rates were higher at 1 h than at 24 h postinoculation. Unlike most bacteria, parasites cannot be enriched; therefore, an optimal recovery process for oocysts from suspected foods is critical. The observations in this study provide guidance concerning the selection of wash solutions giving the highest retrieval of parasite oocysts. PMID:25198596

  9. Removal of chlorophenols from wastewater using commercial acid washed activated carbon.

    PubMed

    El-Dars, Farida M S E; Sayed, Said A; Khalifa, Mohammed G; Alotieby, Abdel Rahman M S; Shalabi, Mohamed E H

    2013-07-01

    The presence of chlorophenols in wastewater represents a serious challenge for its treatment and its further reuse. In this study, the use of commercial acid washed activated carbon as sorbent material for the removal of 2 chlorophenol, 2,4 dichlorophenol and 2,4,6 trichlorophenol from synthetic. aqueous solutions is evaluated. Variables affecting the uptake of these compounds (weight of sorbent material, pH, temperature and shaking time) are investigated to achieve the optimum conditions of removal process. The kinetics of the uptake process indicated that the process was best explained using a pseudo-second order model. As well, the adsorption of the studied chlorophenols on commercially available AC followed the Freundlich isotherm. The thermodynamic parameters further indicated the favorability of the process and that the adsorption was primarily physical in nature enhanced by chemisorptions. PMID:25509944

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

    PubMed

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

    2015-01-01

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

  11. Mathematical evaluation of activated carbon adsorption for surfactant recovery in a soil washing process.

    PubMed

    Ahn, Chi K; Lee, Min W; Lee, Dae S; Woo, Seung H; Park, Jong M

    2008-12-15

    The performances of various soil washing processes, including surfactant recovery by selective adsorption, were evaluated using a mathematical model for partitioning a target compound and surfactant in water/sorbent system. Phenanthrene was selected as a representative hazardous organic compound and Triton X-100 as a surfactant. Two activated carbons that differed in size (Darco 20-40 mesh and >100 mesh sizes) were used in adsorption experiments. The adsorption isotherms of the chemicals were used in model simulations for various washing scenarios. The optimal process conditions were suggested to minimize the dosage of activated carbon and surfactant and the number of washings. We estimated that the requirement of surfactant could be reduced to 33% of surfactant requirements (from 265 to 86.6g) with a reuse step using 9.1g activated carbon (>100 mesh) to achieve 90% removal of phenanthrene (initially 100mg kg-soil(-1)) with a water/soil ratio of 10. PMID:18384951

  12. Washing of Petroleum and Arsenic Contaminated Soil with Ultrasound and Alkali Phosphate Solution

    NASA Astrophysics Data System (ADS)

    Lee, Jung Hwa; Kim, Jae Gon; Cho, Yong-chan; Chon, Chul-Min; Nam, In-Hyun; Keum, Mi Jung

    2015-04-01

    Soil washing of fine textured soil has been a challenging remedial strategy due to its low remediation efficiency. We adapted ultrasound and dispersion solution to increase the remediation efficiency of the soil washing. The ultrasound and dispersion agent may enhance the dispersion of the aggregate into individual particles and may enhance release of contaminants from the aggregate. We collected the arsenic (As) contaminated silt loam soil from a smelting site, spiked with 1% of diesel and incubated for 6 months. We tested the dispersion rate and the release of diesel with the incubated soil at various pH and concentrations of orthophosphate, pyrophosphate and hexametaphosphate with or without the ultrasound of 28 kHz and 400 W. The As concentrations of coarse (> medium silt) and fine (washing. The dispersion rate and diesel release increased with increasing phosphate concentration and pH of the solution. The application of ultrasound sharply increased the dispersion rate and diesel release comparing with no ultrasound. The optimum condition of the soil washing was turned out to be pH 11_10 mM Na-hexametaphosphate with the ultrasound. The concentration of total petroleum hydrocarbon of the incubated soil reduced from 3101.3 mg kg-1 to 14.0 mg kg-1 after 10 minute washing at the optimum condition. The fine fraction had much higher As concentration than the coarse fraction: 44.4 mg kg-1 for the fine fraction and 14.4 mg kg-1 for the coarse fraction. The results of this study indicate that the ultrasound and alkali phosphate solution increase the soil washing efficiency and can be a promising technology for the remediation of fine textured contaminated soils. Key Words : Ultrasound, Phosphate solution, Soil washing, Mixed contaminants

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

    PubMed

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

    2011-10-01

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

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

    NASA Astrophysics Data System (ADS)

    Meredith, Austin Dean

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed Central

    Topacoglu, H; Katsakoglou, S; Ipekci, A

    2014-01-01

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

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

    PubMed

    Ramadhan, Kurnia; Huda, Nurul; Ahmad, Ruzita

    2014-02-01

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

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

    PubMed

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

    2014-03-01

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

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

    PubMed

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

    2014-12-15

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

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

    PubMed

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

    2013-06-01

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

  1. 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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Solution-processed soldering of carbon nanotubes for flexible electronics

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    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, Pd2+ 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.

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

    PubMed

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

    2014-08-01

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

  5. Properties improvement of paper mill sludge-based granular activated carbon fillers for fluidized-bed bioreactor by bentonite (Na) added and acid washing

    Microsoft Academic Search

    Yanjie Li; Qinyan Yue; Wenhong Li; Baoyu Gao; Jinze Li; Jiadan Du

    Properties improvement of paper mill sludge (PMS) based granular activated carbon fillers for fluidized-bed bioreactor (FBBR) was investigated in this study. Bentonite (Na) powders were blended in the dewatered paper mill sludge powders to strengthen the abrasion resistance strength of the fillers. Different acid washing treatments were studied to produce FBBR fillers with optimum performance. The results indicated that granulation

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

    PubMed

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

    2006-09-01

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

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

    PubMed

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

    2014-05-01

    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

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  10. Process for the elimination of waste water produced upon the desulfurization of coking oven gas by means of wash solution containing organic oxygen-carrier, with simultaneous recovery of elemental sulfur

    Microsoft Academic Search

    P. Diemer; W. Brake; R. Dittmer

    1985-01-01

    A process is disclosed for the elimination of waste water falling out with the desulfurization of coking oven gas by means of an organic oxygen carrier-containing washing solution with simultaneous recovery of elemental sulfur. The waste water is decomposed in a combustion chamber in a reducing atmosphere at temperatures between about 1000° and 1100° C. under such conditions that the

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

    Microsoft Academic Search

    F. J. Carrión Fité

    1992-01-01

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

  12. Molecular features of the air/carbonate solution interface.

    PubMed

    Du, Hao; Liu, Jin; Ozdemir, Orhan; Nguyen, Anh V; Miller, Jan D

    2008-02-15

    The nature of the air/carbonate solution interface is considered with respect to water structure by sum-frequency vibrational spectroscopy (SFVS) and molecular dynamics simulations (MDS). Results from this study provide further understating regarding previous observations that the surface tensions of structure making sodium carbonate solutions have been shown to be significantly greater than the surface tensions of structure breaking bicarbonate solutions at equivalent concentrations. This difference in surface tension and its variation with salt concentration is related to the organization of water and ions at the air/solution interface. Spectral results from SFVS show at equivalent concentrations that, for the carbonate solution, the strong water structure signal of 3200 cm(-1) at the air/carbonate solution interface is increased by a factor of 4 when compared to the same signal for the air/bicarbonate solution interface, which spectrum is weaker than the spectrum for the air/water interface in the absence of salt. These results from SFVS are explained by the results from MDS which show that in the case of carbonate solutions the structure making carbonate ions are excluded from the interfacial water region which region is extended in depth. On the other hand, in the case of bicarbonate solutions, the bicarbonate ions are accommodated in the interfacial water region and there is no evidence of an increase in the extent of water structure. These SFVS experimental and MD simulation results provide further information to understand interfacial phenomena of soluble salts at the molecular level. PMID:18035369

  13. Direct determination of carbon dioxide in aqueous solution using mid-infrared quantum cascade lasers.

    PubMed

    Schaden, S; Haberkorn, M; Frank, J; Baena, J R; Lendl, B

    2004-06-01

    A method for the direct determination of carbon dioxide in aqueous solutions using a room-temperature mid-infrared (MIR) quantum cascade laser at 2330 cm(-1) is reported. The absorption values of different carbon dioxide concentrations were measured in a 119 microm CaF2 flow-through cell. An optical system made of parabolic mirrors was used to probe the flow cell and to focus the laser beam on the mercury cadmium telluride (MCT) detector. Aqueous carbon dioxide standards were prepared by feeding different mixtures of gaseous N2 and CO2 through wash bottles at controlled temperature. The concentration of the dissolved CO2 was calculated according to Henry's law, taking into account the temperature and the partial pressure of CO2. The carbon dioxide standards were connected via a selection valve to a peristaltic pump for subsequent, automated measurement in the flow-through cell. A calibration curve was obtained in the range of 0.338 to 1.350 g/L CO2 with a standard deviation of the method sxo equal to 19.4 mg/L CO2. The limit of detection was calculated as three times the baseline noise over time and was determined to be 39 mg/L. PMID:15198817

  14. Wash This Way

    NSDL National Science Digital Library

    American Chemical Society

    2011-01-01

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

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

    Microsoft Academic Search

    Friedemann Freund

    1986-01-01

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

  16. 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...

  17. Adsorption of chromium by activated carbon from aqueous solution

    Microsoft Academic Search

    Diksha Aggarwal; Meenakshi Goyal; R. C. Bansal

    1999-01-01

    Adsorption isotherms of Cr(III) and Cr(VI) ions on two samples of activated carbon fibres and two samples of granulated activated carbons from aqueous solutions in the concentration range 20–1000 mg\\/l have been studied. The adsorption isotherms have been determined after modifying the activated carbon surfaces by oxidation with nitric acid, ammonium persulphate, hydrogen peroxide and oxygen gas at 350°C and

  18. Development assessment of wash water reclamation

    NASA Technical Reports Server (NTRS)

    Putnam, D. F.

    1976-01-01

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

  19. On the texturization of monocrystalline silicon with sodium carbonate solutions

    Microsoft Academic Search

    B. Vallejo; M. González-Mañas; J. Martínez-López; M. A. Caballero

    2007-01-01

    The texturization of monocrystalline silicon wafers using sodium carbonate solution has been investigated. This etching process has been evaluated in terms of the surface morphology and the reflectance value. The results show that for low concentration of sodium carbonate the increase of texturing time decreases the reflectance value because of the change in morphology from hillocks to pyramidal; on the

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    E-print Network

    Hinz, David William

    1987-01-01

    first by the heavy cement, tne lighter cement will precipitate upstream and adjacent to the early cement. Therefore, a carbon isotopic profile through a cement precipitated by hyperfi ltration will show heavy cement at the sandstone shale contact...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...

  2. TANK 7 CHARACTERIZATION AND WASHING STUDIES

    SciTech Connect

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

    2010-02-04

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

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

    NASA Astrophysics Data System (ADS)

    Ghaedi, Mehrorang; Kokhdan, Syamak Nasiri

    2015-02-01

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

  4. Soil washing technology evaluation

    SciTech Connect

    Suer, A.

    1995-04-01

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

  5. Simultaneous leaching and carbon sequestration in constrained aqueous solutions.

    PubMed

    Moon, Ji-Won; Cho, Kyu-Seong; Moberly, James G; Roh, Yul; Phelps, Tommy J

    2011-12-01

    The behavior of metal ions' leaching and precipitated mineral phases of metal-rich fly ash (FA) was examined in order to evaluate microbial impacts on carbon sequestration and metal immobilization. The leaching solutions consisted of aerobic deionized water (DW) and artificial eutrophic water (AEW) that was anaerobic, organic- and mineral-rich, and higher salinity as is typical of bottom water in eutrophic algae ponds. The Fe- and Ca-rich FAs were predominantly composed of quartz, mullite, portlandite, calcite, hannebachite, maghemite, and hematite. After 86 days, only Fe and Ca contents exhibited a decrease in leaching solutions while other major and trace elements showed increasing or steady trends in preference to the type of FA and leaching solution. Ca-rich FA showed strong carbon sequestration efficiency ranging up to 32.3 g CO(2)/kg FA after 86 days, corresponding to almost 65% of biotic carbon sequestration potential under some conditions. Variations in the properties of FAs such as chemical compositions, mineral constituents as well as the type of leaching solution impacted CO(2) capture. Even though the relative amount of calcite increased sixfold in the AEW and the relative amount of mineral phase reached 37.3 wt% using Ca-rich FA for 86 days, chemical sequestration did not accomplish simultaneous precipitation and sequestration of several heavy metals. PMID:21246259

  6. Simultaneous leaching and carbon sequestration in constrained aqueous solutions

    SciTech Connect

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

    2011-01-01

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

  7. Heavy metal contaminants removal by soil washing

    Microsoft Academic Search

    Riyad J Abumaizar; Edward H Smith

    1999-01-01

    The feasibility of soil washing for decontaminating a silty sand spiked with cadmium, chromium, lead, and zinc was evaluated in laboratory-scale batch and column experiments. Soil samples were subjected to chelant extraction using a solution of disodium salt of ethylenediaminetetraacetic acid (Na2EDTA), sodium metabisulfite (Na2S2O5) solution (an inexpensive reducing reagent), and a solution containing a mixture of the two reagents.

  8. Domestic wash water reclamation

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  9. Active dissolution and natural passivation of carbon steel in carbon dioxide-loaded alkanolamine solutions

    SciTech Connect

    Tomoe, Y.; Shimizu, M.; Kaneta, H. [Teikoku Oil Co., Ltd., Tokyo (Japan)

    1996-08-01

    Corrosion rates of carbon steel specimens were measured in carbon dioxide(CO{sub 2})-loaded alkanolamine(amine) solutions by weight-loss tests and by the polarization resistance method. In dilute amine solutions, lower than 10{sup {minus}2} M, corrosion rates were controlled by the formation of protective FeCO{sub 3} scale as in hot, CO{sub 2}-H{sub 2}O environments. Tested amines inhibited CO{sub 2} induced corrosion in the concentration range between 10{sup {minus}2} and 2M. In concentrated amine solutions, higher than 3M, primary and tertiary amines showed markedly different effects on carbon steel corrosion. The corrosion rates of carbon steel rose with the increase in primary amine concentration, whereas the corrosion rates of carbon steel stayed low in tertiary amine solutions even at 6M, due to the formation of protective FeCO{sub 3} scale. Tertiary amines absorb CO{sub 2} as HCO{sub 3}{sup {minus}} in the presence of water. On the contrary, primary amines absorb CO{sub 2} by two ways. One is as HCO{sub 3}{sup {minus}} like tertiary amines, and the other is direct absorption of CO{sub 2} without water, producing amine-carbamate. The chemical substances produced due to the absorption of CO{sub 2} by amines are considered to play important roles not only on corrosion rates but also on the morphology and protectiveness of corrosion products.

  10. 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

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

    2014-01-01

    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

  11. 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

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

    2014-01-01

    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

  12. Nanostructure modification to carbon nanowall surface employing hydrogen peroxide solution

    NASA Astrophysics Data System (ADS)

    Shimoeda, Hironao; Kondo, Hiroki; Ishikawa, Kenji; Hiramatsu, Mineo; Sekine, Makoto; Hori, Masaru

    2014-04-01

    Carbon nanowalls (CNWs), which are three-dimensional carbon nanomaterials consisting of stacks of graphene sheets vertically standing on substrates, possess a mazelike architecture containing high-density graphene edges and large-area plane surfaces. A selective morphological modification technique for the surfaces of CNWs after their growth has been developed employing hydrogen peroxide (H2O2) solution. It was found that oxidative radicals in H2O2 solution formed characteristic nanometer-scale asperities on the CNW surface without etching from the top edges. Photoelectron spectra indicate that hydroxyl adsorption and subsequent reactions at the edge and plane of graphene contribute to the selective morphological change on the CNW surface.

  13. Insights into non-Fickian solute transport in carbonates

    PubMed Central

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

    2013-01-01

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

  14. Solubilities of carbon dioxide in aqueous potassium carbonate solutions mixed with physical solvents

    SciTech Connect

    Park, S.B.; Lee, H.; Lee, K.H. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)] [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)

    1998-09-01

    The removal of acidic gases such as CO{sub 2}, H{sub 2}S, and COS from gas streams is a very important operation for petrochemical, oil refineries, ammonia manufacture, coal gasification, and natural gas purification plants. Here, the solubilities of carbon dioxide in aqueous potassium carbonate (K{sub 2}CO{sub 3}) solutions mixed with physical solvents were measured at 298.2 and 323.2 K with a CO{sub 2} partial-pressure range of 5 kPa to 2 MPa. 1,2-propanediol and propylene carbonate were selected as physical solvents. The aqueous solutions treated in this study were 5 mass% K{sub 2}CO{sub 3}-15 mass% 1,2-propanediol and propylene carbonate were selected as physical solvents. The aqueous solutions treated in this study were 5 mass% K{sub 2}CO{sub 3}-15 mass% propylene carbonate. The experimental solubility results were presented by the mole ratio of CO{sub 2} and K{sub 2}CO{sub 3} contained in the liquid mixture. The addition of 1,2-propanediol to 5 mass% K{sub 2}CO{sub 3} solution lowered the solubility of CO{sub 2} at constant temperature and pressure conditions when CO{sub 2} partial-pressure range of 5 kPa to 2 MPa. In the case of propylene carbonate the addition of propylene carbonate increased the experimental solubilities in the region of low CO{sub 2} partial pressures and decreased as the CO{sub 2} partial pressure was increased above atmospheric. The solubilities of CO{sub 2} decreased with increasing temperature in the range of 298.2 to 323.2 K.

  15. Car wash events are a popular fund-

    E-print Network

    Goodman, Robert M.

    tested a potential solution to this problem: util- izing rain gardens to filter the polluted runoff before it reaches the (Continued on page 2) New Study Shows Rain Gardens Can Effectively Treat Car Wash is then filtered by a rain garden which acts like a sponge soaking up pollutants that would otherwise enter

  16. Wheat Evolution: Dough Washing

    NSDL National Science Digital Library

    Biotechnology and Biological Sciences Research Council

    2012-01-01

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

  17. Enzymes for low temperature washing

    Microsoft Academic Search

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

    1981-01-01

    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,

  18. Aqueous chemical wash compositions

    SciTech Connect

    Bannister, C.E.

    1987-07-21

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

  19. carbonate solid solution at high pressures up to 55 GPa

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    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.

  20. A solution phase fabrication of magnetic nanoparticles encapsulated in carbon

    NASA Astrophysics Data System (ADS)

    Wei, Xian-Wen; Zhu, Guo-Xing; Xia, Chuan-Jun; Ye, Yin

    2006-09-01

    To avoid high energy consumption, intensive use of hardware and high cost in the manufacture of nanoparticles encapsulated in carbon, a simple, efficient and economical solution-phase method for the fabrication of FeNi@C nanostructures has been explored. The reaction to the magnetic metal@C structures here is conducted at a relatively low temperature (160 °C) and this strategy can be transferred to prepare other transition metal@C core-shell nanostructures. The saturation magnetization of metal in metal@C nanostructures is similar to those of the corresponding buck metals. Magnetic metal@C nanostructures with magnetic metal nanoparticles inside and a functionalized carbon surface outside may not only provide the opportunity to tailor the magnetic properties for magnetic storage devices and therapeutics but also make possible the loading of other functional molecules (e.g. enzymes, antigens) for clinic diagnostics, molecular biology, bioengineering, and catalysis.

  1. Solubilities and vapour pressures of saturated aqueous solutions of sodium tetraborate, sodium carbonate, and magnesium sulfate and freezing-temperature lowerings of sodium tetraborate and sodium carbonate solutions

    Microsoft Academic Search

    Alexander Apelblat; Emanuel Manzurola

    2003-01-01

    Solubilities and vapour pressures of water over saturated solutions of sodium tetraborate, sodium carbonate, and magnesium sulfate and freezing-temperature lowerings of sodium tetraborate and sodium carbonate solutions were determined and compared with the literature data. These results permitted the evaluation of osmotic and activity coefficients and molar enthalpies of vaporization.

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

    SciTech Connect

    Peters, T. B.

    2014-01-02

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

  3. Adsorption of nickel(II) from aqueous solution onto activated carbon prepared from coirpith

    Microsoft Academic Search

    K. Kadirvelu; K. Thamaraiselvi; C. Namasivayam

    2001-01-01

    Activated carbon has been prepared from coirpith by chemical activation and characterized. Carbonised coirpith is able to adsorb Ni(II) from aqueous solution. It was noted that a decreasing in the carbon concentration with constant Ni concentration, or an increase in the Ni concentration with constant carbon concentration resulted in a higher nickel uptake per unit weight of carbon. The Langmuir

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

    SciTech Connect

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

    1994-09-01

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

  5. Optimization of narirutin extraction during washing step of the pectin production from citrus peels

    Microsoft Academic Search

    W. C. Kim; D. Y. Lee; C. H. Lee; C. W. Kim

    2004-01-01

    Citrus peels can be a valuable source of pectin and narirutin. Narirutin can be extracted during the washing step of citrus peels in the pectin production process. In this study narirutin extraction conditions were optimized to maximize the narirutin extraction yield while minimized pectin loss. Washing temperature, time, and HCl concentration of the washing solution were chosen as independent variables

  6. Adsorption of zinc(II) from an aqueous solution onto activated carbon

    Microsoft Academic Search

    R Leyva Ramos; L. A Bernal Jacome; J Mendoza Barron; L Fuentes Rubio; R. M Guerrero Coronado

    2002-01-01

    Adsorption isotherms were measured experimentally for Zn(II) adsorption from aqueous solution onto commercial activated carbons C, F-400, F-300 and Centaur HSL in a batch adsorber. The effects of carbon type and solution pH on adsorption isotherms were evaluated in this work. Nearly three times as much Zn(II) adsorbed onto C carbon as on the other three carbon types. The adsorption

  7. Stable aqueous colloidal solutions of intact surfactant-free graphene nanoribbons and related graphitic nanostructures.

    PubMed

    Dimiev, Ayrat M; Gizzatov, Ayrat; Wilson, Lon J; Tour, James M

    2013-04-01

    Here we demonstrate a simple, nondestructive method for the preparation of stable aqueous colloidal solutions of graphene nanoribbons and carbon nanotubes. The method includes sonication of carbon nanomaterials in hypophosphorous acid, filtration accompanied by washing the solids with water and dispersion of the solids in a fresh portion of water to form colloidal solutions. PMID:23435853

  8. The passivity of 304 stainless steel in propylene carbonate solutions

    SciTech Connect

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

    1992-01-01

    This paper reports that the passivation behavior of 304 stainless steel in anhydrous propylene carbonate (PC) containing 0.5M LiAsF{sub 6} or 0.5M LiClO{sub 4} was studied. The air-formed film on 304SS is stable up to the oxidation potential of PC (PC{sub ox}). Scratch tests show that the bared 304SS surface repassivates in the anhydrous PC solutions of either electrolyte by chemisorption of PC molecules below PC{sub ox}. In PC/0.5M LiAsF{sub 6} solutions, the 304SS is not passivated at potentials above PC{sub ox}. This is attributed to the formation of a thin metastable perchlorate salt film or an adsorbed layer of perchlorate anions. When the perchlorate anions oxidize, the passivation becomes unstable and pitting occurs. Small (3-8 volume percent) additions of PC/0.5M LiClO{sub 4} to PC/0.5M LiAsF{sub 6} solutions raised the passive range to the perchlorate oxidation potential. Small quantities of water, propylene glycol, and propylene oxide added to PC lightly improve the passive range of the 304 stainless steel.

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

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

    PubMed Central

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

    2014-01-01

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

  11. The resistance of recent marine carbonate sediments to solution 

    E-print Network

    Jansen, John F

    1962-01-01

    sediment samples. TABLE 2 Ca ++ and Mg Content o Carbonate Sed f Unground Natural 2/ iments? S amp le Mes h Size CaCO MgCO 3 Sample Mesh Size CaCO 3 Mgco 2 ? 18 X 2 ? 35 X 2-. 60 X 4-10 X 94. 50 93. 82 93. 48 90. 16 4. 39 2. 03 2. 28 6..., Table 1. These analyses were obt. ained after th. e sediments had been in contact with the Figure 2 relates the dissolve NaHCO solution for ei 3 ++ d amounts o f Ca and ght months e+ Mg in mi 11 imo les to the percentage of MgCO in the sediments...

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

    Microsoft Academic Search

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

    2011-01-01

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

  13. Ethylbenzene Removal by Carbon Nanotubes from Aqueous Solution

    PubMed Central

    Bina, Bijan; Pourzamani, Hamidreza; Rashidi, Alimorad; Amin, Mohammad Mehdi

    2012-01-01

    The removal of ethylbenzene (E) from aqueous solution by multiwalled, single-walled, and hybrid carbon nanotubes (MWCNTs, SWCNTs, and HCNTs) was evaluated for a nanomaterial dose of 1?g/L, concentration of 10–100?mg/L, and pH 7. The equilibrium amount removed by SWCNTs (E: 9.98?mg/g) was higher than by MWCNTs and HCNTs. Ethylbenzene has a higher adsorption tendency on CNTs, so that more than 98% of it adsorbed in first 14?min, which is related to the low water solubility and the high molecular weight. The SWCNTs performed better for ethylbenzene sorption than the HCNTs and MWCNTs. Isotherms study indicates that the BET isotherm expression provides the best fit for ethylbenzene sorption by SWCNTs. Carbon nanotubes, specially SWCNTs, are efficient and rapid adsorbents for ethylbenzene which possess good potential applications to maintain high-quality water. Therefore, it could be used for cleaning up environmental pollution to prevent ethylbenzene borne diseases. PMID:22187576

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

    NASA Technical Reports Server (NTRS)

    1983-01-01

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

  15. Theromdynamics of carbon in nickel-based multicomponent solid solutions

    Microsoft Academic Search

    1978-01-01

    The activity coefficient of carbon in nickel, nickel-titanium, nickel-titanium-chromium, nickel-titanium-molybdenum and nickel-titanium-molybdenum-chromium alloys has been measured at 900, 1100 and 1215°C. The results indicate that carbon obeys Henry's Law over the range studied (0 to 2 at. percent). The literature for the nickel-carbon and iron-carbon systems are reviewed and corrected. For the activity of carbon in iron as a function

  16. Impedance and ellipsometer measurements of lithium electrodes in propylene carbonate solutions

    SciTech Connect

    Schwager, F.; Muller, R.H.

    1983-09-01

    Complex electrode impedance has been measured for lithium after exposure to nitrogen, propylene carbonate and LiClO/sub 4/ solutions in propylene carbonate. Results for zero-field exchange current density and polarization resistance are in agreement with earlier current pulse measurements. Ellipsometer measurements show a different electrode behavior for anodic and cathodic reactions in perchlorate solution.

  17. Pecan shell activated carbon: synthesis, characterization, and application for the removal of copper from aqueous solution

    Microsoft Academic Search

    Seyed A Dastgheib; David A Rockstraw

    2001-01-01

    Activated carbon with a high adsorption capacity for removal of copper ions from aqueous solution is produced from pecan shells. Air and phosphoric acid are used for the oxidation and the modification or development of oxygen- or phosphorus\\/oxygen-containing groups on the carbon surface. It was found that the adsorption capacity of the produced carbon is significantly higher than that of

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

    E-print Network

    Mellor-Crummey, John

    and physical properties, single-walled carbon nanotube (SWCNT) has been considered for many applications. We, mechanical application, etc. #12;Structure Controlled Synthesis of Carbon Nanotubes Theerapol Thurakitseree1Structure Controlled Synthesis of Single-Walled Carbon Nanotubes Using Solution Based Catalyst

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

    Microsoft Academic Search

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

    2002-01-01

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

  20. Washing Fresh Fruits and Vegetables 

    E-print Network

    Scott, Amanda

    2008-09-05

    . Examples of pathogens include Salmonella, E. coli 0157:H7 and Hepatitis A. If you eat a contaminated fruit or vegetable, it could cause a foodborne illness. Common signs of foodborne illness in- clude nausea, vomiting, diarrhea, headache and fever.... These signs usually appear within 12 to 72 hours from the time the food was eaten. Foodborne illness can be serious. To re- duce your risk, follow these steps for wash- ing fresh fruits and vegetables. Wash your hands and cooking areas Wash your hands...

  1. Hand Washing in Emergency Situations

    E-print Network

    Schoessow, Courtney

    2005-09-30

    - nated. However, it is still important for you and your family to wash your hands often to avoid illness. When should you wash your hands? ? Before preparing or eating food ? After using the bathroom ? After changing diapers or cleaning a child who... the number of Hand Washing in Emergency Situations germs on your skin. Remember: Products vary in the amount of the hand rub needed to reduce the number of bacteria on your hands. Read the product details on the back of the container for directions...

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

    Microsoft Academic Search

    Jian Zhang; Yan Li; Chenglu Zhang; Yuming Jing

    2008-01-01

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

  3. A model for the adsorption of single metal ion solutes in aqueous solution onto activated carbon produced from pecan shells

    Microsoft Academic Search

    Seyed A. Dastgheib; David A. Rockstraw

    2002-01-01

    Adsorption isotherms for activated carbon made from pecan shells have been obtained at 25°C and an approximate pH of 3 for a number of metal ion solutes. It was found that the Slips and Freundlich equations were satisfactory for explaining the experimental data. The correlation of metal ion adsorption with the solute parameters of metal ion electronegativity and first stability

  4. 7 CFR 58.429 - Washing machine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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

  5. 7 CFR 58.429 - Washing machine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

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

    SciTech Connect

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

    2012-10-25

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

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

    SciTech Connect

    Peters, T. B.

    2013-10-01

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

  8. Solubility of carbon dioxide in aqueous solutions of 2-amino-2-methyl-1,3-propanediol

    SciTech Connect

    Baek, J.I.; Yoon, J.H. [Korea Electric Power Research Inst., Taejon (Korea, Republic of). Center for advanced Studies in Energy and the Environment] [Korea Electric Power Research Inst., Taejon (Korea, Republic of). Center for advanced Studies in Energy and the Environment

    1998-07-01

    The equilibrium solubility of carbon dioxide in aqueous solutions of 2-amino-2-methyl-1,3-propanediol (AMPD) has been measured at (30, 40, and 60) C and the partial pressure of carbon dioxide ranging from (0.5 to 3065) kPa. The concentrations of the aqueous solutions were (10 and 30) mass % AMPD. The tendency of the solubility of carbon dioxide in 30 mass % AMPD aqueous solution at 40 C was found to be similar to that in 30 mass % N-methyldiethanolamine aqueous solution.

  9. Relation Between the Adsorbed Quantity and the Immersion Enthalpy in Catechol Aqueous Solutions on Activated Carbons

    PubMed Central

    Moreno-Piraján, Juan Carlos; Blanco, Diego; Giraldo, Liliana

    2012-01-01

    An activated carbon, CarbochemTM—PS230, was modified by chemical and thermal treatment in flow of H2, in order to evaluate the influence of the activated carbon chemical characteristics in the adsorption of the catechol. The catechol adsorption in aqueous solution was studied along with the effect of the pH solution in the adsorption process of modified activated carbons and the variation of immersion enthalpy of activated carbons in the aqueous solutions of catechol. The interaction solid-solution is characterized by adsorption isotherms analysis, at 298 K and pH 7, 9 and 11 in order to evaluate the adsorption value above and below that of the catechol pKa. The adsorption capacity of carbons increases when the solution pH decreases. The retained amount increases slightly in the reduced carbon to maximum adsorption pH and diminishes in the oxidized carbon. Similar conclusions are obtained from the immersion enthalpies, whose values increase with the solute quantity retained. In granular activated carbon (CAG), the immersion enthalpies obtained are between 21.5 and 45.7 J·g?1 for catechol aqueous solutions in a range of 20 at 1500 mg·L?1. PMID:22312237

  10. Nitroimidazoles adsorption on activated carbon cloth from aqueous solution.

    PubMed

    Ocampo-Pérez, R; Orellana-Garcia, F; Sánchez-Polo, M; Rivera-Utrilla, J; Velo-Gala, I; López-Ramón, M V; Alvarez-Merino, M A

    2013-07-01

    The objective of this study was to analyze the equilibrium and adsorption kinetics of nitroimidazoles on activated carbon cloth (ACC), determining the main interactions responsible for the adsorption process and the diffusion mechanism of these compounds on this material. The influence of the different operational variables, such as ionic strength, pH, temperature, and type of water (ultrapure, surface, and waste), was also studied. The results obtained show that the ACC has a high capacity to adsorb nitroimidazoles in aqueous solution. Electrostatic interactions play an important role at pH<3, which favors the repulsive forces between dimetridazole or metronidazole and the ACC surface. The formation of hydrogen bonds and dispersive interactions play the predominant role at higher pH values. Modifications of the ACC with NH3, K2S2O8, and O3 demonstrated that its surface chemistry plays a predominant role in nitroimidazole adsorption on this material. The adsorption capacity of ACC is considerably high in surface waters and reduced in urban wastewater, due to the levels of alkalinity and dissolved organic matter present in the different types of water. Finally, the results of applying kinetic models revealed that the global adsorption rate of dimetridazole and metronidazole is controlled by intraparticle diffusion. PMID:23623410

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

    Microsoft Academic Search

    D. Aurbach; A. Zaban

    1995-01-01

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

  12. Efficacy of Post-Wash Shell Egg Sanitizers

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Ceramic wash-coat for catalyst support

    DOEpatents

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

    2012-08-14

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

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

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

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

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

    PubMed

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

    2012-06-01

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

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

    SciTech Connect

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

    2010-02-10

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

  17. Removal of total organic carbon from aqueous solution containing polyvinyl alcohol by electrocoagulation technology

    Microsoft Academic Search

    Wei-Lung Chou; Chih-Ta Wang; Chia-Wei Hsu; Kai-Yu Huang; Te-Chao Liu

    2010-01-01

    The removal of total organic carbon (TOC) from aqueous solution containing polyvinyl alcohol (PVA) using iron electrocoagulation (EC) was investigated. Iron hydroxides generated during EC were used to remove PVA and TOC from the aqueous solution, and the effects of varying current density and solution temperature on PVA and TOC adsorption characteristics were evaluated. The findings indicated that complete PVA

  18. Adsorptive removal of aniline by granular activated carbon from aqueous solutions with catechol and resorcinol

    Microsoft Academic Search

    S. Suresh; V. C. Srivastava; I. M. Mishra

    2012-01-01

    In the present paper, the removal of aniline by adsorption process onto granular activated carbon (GAC) is reported from aqueous solutions containing catechol and resorcinol separately. The Taguchi experimental design was applied to study the effect of such parameters as the initial component concentrations (C0, i) of two solutes (aniline and catechol or aniline and resorcinol) in the solution, temperature

  19. Enhanced sludge washing evaluation plan

    SciTech Connect

    Jensen, R.D.

    1994-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

    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.

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

    SciTech Connect

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

    2007-08-15

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

  2. High-pressure and high-temperature Raman spectroscopy of carbonate ions in aqueous solution

    Microsoft Academic Search

    Isabelle Martinez; Carmen Sanchez-Valle; Isabelle Daniel; Bruno Reynard

    2004-01-01

    Two aqueous solutions of sodium carbonate (0.5 and 2 m) have been studied by in situ Raman spectroscopy in the 1–30 GPa, 25–400 °C pressure–temperature (P–T) range, in an externally heated diamond anvil cell. Neither bicarbonate ions nor CO2 species were observed; carbonate ions were found to be the major species in these solutions over the entire P–T range investigated,

  3. Comparison of activated carbon and ion-exchange resins in recovering copper from cyanide leach solutions

    Microsoft Academic Search

    X. Dai; P. L. Breuer; M. I. Jeffrey

    2010-01-01

    The use of activated carbon and ion-exchange resins for recovering copper cyanide from gold leach solutions is compared in detail. When using activated carbon, the overall cyanide-to-copper ratio should be reduced to ?2 to achieve the most effective adsorption. This can be accomplished by dissolving metallic copper into the leach solution. However when using ion-exchange resins to recover the copper,

  4. The Breakdown Mechanism of Diamond Like Carbon Coated Nickel in Chloride Solution

    E-print Network

    The Breakdown Mechanism of Diamond Like Carbon Coated Nickel in Chloride Solution R.S. Lillard, D deposited nickel (CVD Ni) coated with 5 micro- meters of diamond like carbon (DLC) produced by plasma source analyzed within the context of an equivalent circuit model which incorporated three time constants

  5. SiC coating on carbon fibres by a solution coating process

    Microsoft Academic Search

    Yu-Qing Wang; Zuo-Ming Wang; Jun-Ying Yang; Feng-Qiu Zhang; Ben-Lian Zhou

    1995-01-01

    One way of overcoming the shortcomings of carbon fibres is to coat them with SiC. In this work, carbon fibres were coated with a polycarbosilane solution and then pyrolysed continuously at high temperature to obtain the SiC coating. Effects of the coating process on the structure of the coating and the properties of the coated fibres were studied in detail.

  6. Perchlorate Sorption\\/Transformation from Solution Using Activated Carbon

    Microsoft Academic Search

    E. L. Pyatt; A. P. Jackman; D. Rolston

    2002-01-01

    Because perchlorate (ClO4-) inhibits iodide uptake it is a contaminant of concern in groundwater. Therefore ClO4- contaminated drinking water must be treated to either remove ClO4- or reduce ClO4- to chloride (Cl-). Batch and column experiments using varying operational conditions with powdered activated carbon (PAC) and granular activated carbon (PAC) were performed to evaluate PAC and GAC capacity to adsorb

  7. Hand Washing in Emergency Situations 

    E-print Network

    Schoessow, Courtney

    2005-09-30

    the number of Hand Washing in Emergency Situations germs on your skin. Remember: Products vary in the amount of the hand rub needed to reduce the number of bacteria on your hands. Read the product details on the back of the container for directions...

  8. A Window-Washing Challenge

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2010-01-01

    Skyscrapers sure do have a lot of windows, and these windows are cleaned and checked regularly. All this takes time, money, and puts workers at potential risk. Might there be a better way to do it? In this article, the author discusses a window-washing challenge and describes how students can tackle this task, pick up the challenge, and creatively…

  9. Abdominopelvic washings: A comprehensive review

    PubMed Central

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

    2013-01-01

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

  10. Copper and strontium adsorption by a novel carbon material manufactured from pecan shells

    Microsoft Academic Search

    Reyad A. Shawabkeh; David A. Rockstraw; Ron K. Bhada

    2002-01-01

    A novel carbon material (PS276a) was produced from pecan shells, a waste product of the agricultural industry. Preparation of this material involved the impregnation of the pecan shell feedstock with a phosphoric acid solution. Activation was followed by a water wash and a sodium hydroxide treatment. The carbon produced was characterized by adsorption of N2 and revealed a pore structure

  11. Removal of insecticide carbofuran from aqueous solutions by banana stalks activated carbon

    Microsoft Academic Search

    J. M. Salman; B. H. Hameed

    2010-01-01

    In this work, activated carbon was prepared from banana stalks (BSAC) waste to remove the insecticide carbofuran from aqueous solutions. The effects of contact time, initial carbofuran concentration, solution pH and temperature (30, 40 and 50°C) were investigated. Adsorption isotherm, kinetics and thermodynamics of carbofuran on BSAC were studied. Equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherm

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

    Microsoft Academic Search

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

    2008-01-01

    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

  13. Fabrication of carbon nanowires by pyrolysis of aqueous solution of sugar within asbestos nanofibers

    NASA Astrophysics Data System (ADS)

    Butko, V. Yu.; Fokin, A. V.; Nevedomskii, V. N.; Kumzerov, Yu. A.

    2015-05-01

    Carbon nanowires have been fabricated by pyrolysis of an aqueous solution of sugar in nanochannels of asbestos fibers. Electron microscopy demonstrates that the diameter of these nanochannels corresponds to the diameter of the thinnest of the carbon nanowires obtained. Some of these nanowires have a graphite crystal lattice and internal pores. After asbestos is etched out, the carbon nanowires can retain the original shape of the asbestos fibers. Heating in an inert atmosphere reduces the electrical resistivity of the carbon nanowires to ˜0.035 ? cm.

  14. Extraction of actinides into aqueous polyethylene glycol solutions from carbonate media in the presence of alizarin complexone

    SciTech Connect

    Molochnikova, N.P.; Frenkel', V.Ya.; Myasoedov, B.F.; Shkinev, V.M.; Spivakov, B.Ya.; Zolotov, Yu.A.

    1987-01-01

    Actinide extraction in a two-phase aqueous system based on polyethylene glycol from carbonate solutions of various compositions in presence of alizarin complexone is studied. It is shown that the nature of the alkali metals affects actinide extraction into the polyethylene glycol phase. Tri- and tetravalent actinides are extracted maximally from sodium carbonate solutions. Separation of actinides in different oxidation states is more effective in potassium carbonate solutions. The behavior of americium in different oxidation states in the system carbonate-polyethylene glycol-complexone is studied. The possibility of extraction separation of microamount of americium(V) from curium in carbonate solutions in presence of alizarin complexone is shown.

  15. ADSORPTION OF LEVODOPA FROM AQUEOUS SOLUTION ON GRANULAR ACTIVATED CARBON

    Microsoft Academic Search

    JULCOUR-LEBIGUE Carine; Centro de Química Farmacéutica

    Granular activated carbon filtration has been successfully used in wastewater and drinking water treatment plants, for removal of different pollutants and it is the most efficient conventional treatment method for the purification of water contaminated by other pollutants like pesticides. Levodopa is a drug used to treat Parkinson disease, a progressive condition in which the part of the brain responsible

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

    Microsoft Academic Search

    Stephen Bedford Clark

    2009-01-01

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

  17. Tuning the optical properties of carbon nanotube solutions using amphiphilic self-assembly

    NASA Astrophysics Data System (ADS)

    Arnold, Michael S.; Stupp, Samuel I.; Hersam, Mark C.

    2003-07-01

    Recently it has been shown that aqueous solutions of sodium dodecyl sulfate (SDS) encapsulated and polymer wrapped single-walled carbon nanotubes (SWNTs) fluoresce in the near infrared (NIR) in the regime of the E11 van Hove transitions for semiconducting SWNTs. For bundled SWNTs, fluorescence is observed to be quenched along with a shift and broadening of the absorbance spectrum. Here, we study two other commercially available surfactants, BRIJ-97 and Triton-X-100, by analysis of carbon nanotube fluorescence and absorptivity in the NIR. It is found that changing the surfactant alters the corresponding optical properties of the solubilized carbon nanotubes. The NIR absorbance spectra of BRIJ-97 and Triton-X-100 carbon nanotube solutions are also compared with the absorbance spectrum of NaCl destabilized SDS-SWNT solutions. By controlling the amount of NaCl added to an aqueous solution of SDS-SWNTs, the optical absorbance spectrum can be made to match that of BRIJ-97 and Triton-X-100 solutions. Lastly, a correlation is drawn between the amount of shift in the absorbance spectrum and the fluorescence intensity, independent of surfactant used. This shift and decrease in fluorescence intensity may be due to carbon nanotube bundling.

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

    Microsoft Academic Search

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

    2004-01-01

    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

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

    DOEpatents

    Rau, Gregory Hudson (Castro Valley, CA)

    2012-05-15

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

  20. Perchlorate Sorption/Transformation from Solution Using Activated Carbon.

    NASA Astrophysics Data System (ADS)

    Pyatt, E. L.; Jackman, A. P.; Rolston, D.

    2002-12-01

    Because perchlorate (ClO4-) inhibits iodide uptake it is a contaminant of concern in groundwater. Therefore ClO4- contaminated drinking water must be treated to either remove ClO4- or reduce ClO4- to chloride (Cl-). Batch and column experiments using varying operational conditions with powdered activated carbon (PAC) and granular activated carbon (PAC) were performed to evaluate PAC and GAC capacity to adsorb ClO4- and/or reduce ClO4- to Cl-, chlorite (ClO2-) and chlorate (ClO3-). Varying operational conditions were particle size, pH, and ClO4- salt cation. ClO4- adsorption was affected by particle size, pH, and cation salt. ClO4- adsorption on PAC and GAC is partially reversible.

  1. Ozone-activated Carbon Mineralization of 17-?-Ethynylestradiol Aqueous Solutions

    Microsoft Academic Search

    F. J. Beltrán; P. Pocostales; P. Alvarez; A. Aguinaco

    2009-01-01

    Ozone and activated carbon (AC) have been used on the removal of 17?-ethynylestradiol (ETOL), a pharmaceutical compound, and its oxidation by-products. Although single ozonation is not able to totally remove the by-products formed from the degradation of the parent compound (about 65% of TOC removal at pH 7 after 2-hour reaction), the ozone\\/AC system led not only to higher TOC

  2. Solution-reactor-produced Mo-99 using activated carbon to remore I-131

    SciTech Connect

    Kitten, S.; Cappiello, C.

    1998-06-01

    The production of {sup 99}Mo in a solution reactor was explored. Activated charcoal was used to filter the {sup 131}I contaminant from an irradiated fuel solution. Gamma spectroscopy confirmed that the activated carbon trapped a significant amount of {sup 131}I, as well as notable amounts of {sup 133}Xe, {sup 105}Rb, and {sup 140}Ba; the carbon trapped a diminutive amount of {sup 99}Mo. The results promote the idea of solution-reactor-produced {sup 99}Mo. Solution reactors are favorable both energetically and environmentally. A solution reactor could provide enough {sup 99}Mo/{sup 99m}Te to support both the current and future radiopharmaceutical needs of the U.S.

  3. Electrical Switchability and Dry-Wash Durability of Conductive Textiles

    PubMed Central

    Wu, Bangting; Zhang, Bowu; Wu, Jingxia; Wang, Ziqiang; Ma, Hongjuan; Yu, Ming; Li, Linfan; Li, Jingye

    2015-01-01

    There is growing interest in the area of conductive textiles in the scientific and industrial community. Herein, we successfully prepared a conductive textile via covalently grafting polyaniline (PANI) onto cotton by a multi-step treatment process. The conductivity of the resultant fabric could be tuned by immersing in water having different pH values. The conductive and insulating properties of the textile could be conveniently switched by alternately immersing in acidic and alkaline bath solutions. Most importantly, the resultant conductive fabrics were able to withstand 40 simulated dry-wash cycles, with almost no decay in the electrical conductivity, indicating their excellent dry-wash durability. The present strategy for fabricating conductive fabrics with excellent switchability of electrical properties and dry-wash durability is expected to provide inspiration for the production of multifunctional conductive textiles for use in hash or sensitive conditions. PMID:26066704

  4. Electrical Switchability and Dry-Wash Durability of Conductive Textiles.

    PubMed

    Wu, Bangting; Zhang, Bowu; Wu, Jingxia; Wang, Ziqiang; Ma, Hongjuan; Yu, Ming; Li, Linfan; Li, Jingye

    2015-01-01

    There is growing interest in the area of conductive textiles in the scientific and industrial community. Herein, we successfully prepared a conductive textile via covalently grafting polyaniline (PANI) onto cotton by a multi-step treatment process. The conductivity of the resultant fabric could be tuned by immersing in water having different pH values. The conductive and insulating properties of the textile could be conveniently switched by alternately immersing in acidic and alkaline bath solutions. Most importantly, the resultant conductive fabrics were able to withstand 40 simulated dry-wash cycles, with almost no decay in the electrical conductivity, indicating their excellent dry-wash durability. The present strategy for fabricating conductive fabrics with excellent switchability of electrical properties and dry-wash durability is expected to provide inspiration for the production of multifunctional conductive textiles for use in hash or sensitive conditions. PMID:26066704

  5. Washing and caustic leaching of Hanford Tank C-106 sludge

    SciTech Connect

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

    1996-10-01

    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).

  6. Optoelectronically automated system for carbon nanotubes synthesis via arc-discharge in solution

    NASA Astrophysics Data System (ADS)

    Bera, Debasis; Brinley, Erik; Kuiry, Suresh C.; McCutchen, Matthew; Seal, Sudipta; Heinrich, Helge; Kabes, Bradley

    2005-03-01

    The method of arc discharge in the solution is unique and inexpensive route for synthesis of the carbon nanotubes (CNTs), carbon onions, and other carbon nanostructures. Such a method can be used for in situ synthesis of CNTs decorated with nanoparticles. Herein, we report a simple and inexpensive optoelectronically automated system for arc discharge in solution synthesis of CNTs. The optoelectronic system maintains a constant gap between the two electrodes allowing a continuous synthesis of the carbon nanostructures. The system operates in a feedback loop consisting of an electrode-gap detector and an analog electronic unit, as controller. This computerized feeding system of the anode was used for in situ nanoparticles incorporated CNTs. For example, we have successfully decorated CNTs with ceria, silica, and palladium nanoparticles. Characterizations of nanostructures are performed using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy dispersive spectroscopy, and scanning electron microscopy.

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

    SciTech Connect

    Ishihara, S.; Pulido, L.L. [Kyoto Univ. (Japan); Kajimoto, T. [Wakayama Industrial Technology Center (Japan)

    1996-12-31

    Although wood has essentially been excluded as a starting material for the production of granular activated carbon because of the poor strength and friability of the products, powdered wood based activated carbons are still being used in water treatment and other liquid phase applications. However, the capability of powdered wood-based charcoal which in itself porous has not been fully known. Few studies have been conducted in harnessing its potential for adsorption purposes especially in water treatment. This study was conducted to investigate the possibility of using wood based carbonized materials from Sugi (Cryptomeria japonica D. Don) as adsorption materials in aqueous solutions of heavy metals like mercury, zinc, lead, cadmium and arsenic. However, of all the heavy metals investigated, mercury is considered to be the most toxic so this paper describes only the adsorption ability of the carbonized materials in adsorbing this metal from aqueous solutions of different concentrations.

  8. Optoelectronic ally automated system for carbon nanotubes synthesis via arc-discharge in solution

    SciTech Connect

    Bera, Debasis; Brinley, Erik; Kuiry, Suresh C.; McCutchen, Matthew; Seal, Sudipta; Heinrich, Helge; Kabes, Bradley [Surface Engineering and Nanotechnology Facility - SNF, Advanced Materials Processing and Analysis Center - AMPAC, and Mechanical, Materials and Aerospace Engineering - MMAE, University of Central Florida - UCF, 4000 Central Florida Blvd., Eng 1, no. 381, Orlando, Florida 32816 (United States); Advanced Materials Processing and Analysis Center - AMPAC and Department of Physics, University of Central Florida, 4000 Central Florida Blvd., Eng 1, no. 381, Orlando, Florida 32816 (United States); NSF REU Site (UCF), Department of Chemical Engineering, University of Minnesota, Duluth, Minnesota 55803 (United States)

    2005-03-01

    The method of arc discharge in the solution is unique and inexpensive route for synthesis of the carbon nanotubes (CNTs), carbon onions, and other carbon nanostructures. Such a method can be used for in situ synthesis of CNTs decorated with nanoparticles. Herein, we report a simple and inexpensive optoelectronically automated system for arc discharge in solution synthesis of CNTs. The optoelectronic system maintains a constant gap between the two electrodes allowing a continuous synthesis of the carbon nanostructures. The system operates in a feedback loop consisting of an electrode-gap detector and an analog electronic unit, as controller. This computerized feeding system of the anode was used for in situ nanoparticles incorporated CNTs. For example, we have successfully decorated CNTs with ceria, silica, and palladium nanoparticles. Characterizations of nanostructures are performed using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy dispersive spectroscopy, and scanning electron microscopy.

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

    SciTech Connect

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

    1998-05-01

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

  10. Removal of Cr(VI) from aqueous solution by adsorption onto activated carbon

    Microsoft Academic Search

    K. Selvi; S. Pattabhi; K. Kadirvelu

    2001-01-01

    Activated carbon (AC) prepared from coconut tree sawdust was used as an adsorbent for the removal of Cr(VI) from aqueous solution. Batch mode adsorption studies were carried out by varying agitation time, initial Cr(VI) concentration, carbon concentration and pH. Langmuir and Freundlich adsorption isotherms were applied to model the adsorption data. Adsorption capacity was calculated from the Langmuir isotherm and

  11. Anodic oxidation of 3,4-dihydroxyphenylacetic acid on carbon electrodes in acetic acid solutions

    Microsoft Academic Search

    Slawomir Michalkiewicz; Agata Skorupa

    2010-01-01

    The electrochemical oxidation of 3,4-dihydroxyphenylacetic acid (DOPAC) on a carbon fiber microelectrode (CF) and a glassy carbon macroelectrode (GC) in glacial acetic acid solutions was investigated using voltammetric techniques. Voltammograms recorded at these electrodes show well-defined single waves or peaks. The proposed mechanism of the anodic oxidation of DOPAC consists of two successive one-electron one-proton steps. The loss of the

  12. Removal of Acid Dyes from Aqueous Solutions using Chemically Activated Carbon

    Microsoft Academic Search

    Özgül Gerçel; H. Ferdi Gerçel

    2009-01-01

    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

  13. Carbon-centric Computing: IT Solutions for Climate Change

    Microsoft Academic Search

    Aditya K. Ghose; Helen M. Hasan; T. Spedding

    2008-01-01

    IT has a role to play in the current debate on climate change. The current discourse on IT and climate change views IT in a negative light, as a polluter. What remains unrecognized is the critical role of IT as a source of solutions to the climate change problem. We live in a massive, inter-connected Planet Earth Supply Chain. IT

  14. Photoinduced Transformation of Carbon Monoxide in Aqueous Solution

    NASA Astrophysics Data System (ADS)

    Park, Hyoung Ryun; Getoff, Nikola

    1988-05-01

    The photoinduced conversion of CO in aqueous solution under the influence of vacuum-uv radiation at ? = 185 nm has been investigated at pH values ranging from 2 to 13. Formaldehyde, glyoxal, carboxylic acids and small amounts of glycol were determined as final products. Initial quantum yields for product formation have been determined. A probable reaction mechanism is presented.

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

    DOEpatents

    Francis, Raymond

    2012-11-06

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

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

    PubMed

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

    2013-01-01

    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

  17. TANK 4 CHARACTERIZATION, SETTLING, AND WASHING STUDIES

    SciTech Connect

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

    2009-09-29

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

  18. Comparative alkali washing of simulated radioactive sludge

    SciTech Connect

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

    1996-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1999-03-01

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

  20. Corrosion of Carbon Steel in Carbon Dioxide-Saturated Solutions Containing Small Amounts of Hydrogen Sulfide

    Microsoft Academic Search

    K. Videm; J. Kvarekvaal

    1995-01-01

    Carbon steel specimens were exposed in carbon dioxide (COâ)-containing brine with different amounts of hydrogen sulfide (HâS) at 70 C and 80 C. The addition of 0.02 mmol\\/L sulfide, corresponding to 45 Pa HâS partial pressure (P{sub HâS}), to brine with 70 kPa COâ at pH 4.2 caused rapid formation of a protective corrosion film. After â¼ 15 min, the

  1. Wastewater washing screens out solids

    SciTech Connect

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

    1994-09-01

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

  2. Fluid and Solute Transport from a Conduit to the Matrix in a Carbonate Aquifer System

    Microsoft Academic Search

    Eric W. Peterson; Carol M. Wicks

    2005-01-01

    Within carbonate systems, the working hypothesis suggests that when a conduit is flooded fluid and solute migrate from the\\u000a conduit into the matrix. This flux of fluid and solute into the matrix creates a reservoir that can be slowly released once\\u000a the flooding recedes. Although hypothesized, these fluxes have never been measured. To quantify the distance that a fluid\\u000a and

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

    PubMed

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

    2014-05-01

    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. PMID:24675812

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

    Microsoft Academic Search

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

    2011-01-01

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

  5. Sorption of nickel ions from aqueous solutions using activated carbon derived from walnut shell waste

    Microsoft Academic Search

    Gang Wang; Aimin Li; Mingzhi Li

    2010-01-01

    Studies on a batch sorption process using activated carbon derived from walnut shell were investigated to remove Ni(II) ions from aqueous solutions. The infl uence of operational conditions such as contact time (0–150 min), solution initial pH (2–8), Ni(II) initial concentration (10–80 mg\\/L), sorbent mass (0.05–1.0 g\\/100 mL) and temperature (293–313 K) on the sorption was studied. Sorption data of

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

    SciTech Connect

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

    2008-05-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

    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.

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

    PubMed

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

    2015-04-27

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

  9. Stress Corrosion Cracking Characteristics of a Range of Pipeline Steels in Carbonate-Bicarbonate Solution

    Microsoft Academic Search

    R. N. Parkins; W. K. Blanchard Jr; E. N. Belhimer

    1993-01-01

    Stress corrosion cracking (SCC) characteristics of a range of pipeline steels immersed in a carbonate-bicarbonate solution were studied in terms of the deleterious effects of small-amplitude cyclic loading on threshold stress, together with the increase of crack nucleation and the decrease of average crack growth rates with increasing test times. Data were reported on conditions for coalescence or otherwise of

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

    SciTech Connect

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

    2001-11-15

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

  11. SEPARATION OF LITHIUM ISOTOPES. I. INCOMPLETE PRECIPITATION OF LITHIUM CARBONATE FROM AMMONIAC ALKALINE SOLUTION

    Microsoft Academic Search

    S. Taniguchi; I. Shioya; O. Toyama; T. Hayakawa

    1960-01-01

    Isotopic separation factors for the incomplete and slow precipitation of ; lithium carbonate from ammoniac alkaline solution were measured. Mean separation ; factors for the 30 to 40 wt% precipitation at 0 and 18 deg C are 1.015 plus or ; minus 0.004 and 1.011 plus or minus 0.003, respectively. (auth);

  12. Mixed electrolyte solutions of propylene carbonate and dimethoxyethane for high energy density batteries

    Microsoft Academic Search

    Y. Matsuda; H. Satake

    1980-01-01

    The effects of mixing propylene carbonate (PC) and dimethoxyethane (DME), containing some perchlorates, are investigated with reference to the electric conductance, dielectric constant, and viscosity. It is found that the viscosity of the mixed solvents increases when PC is added into DME, and the experimental values tend to be lower than the predictions based on the ideal solution theory. The

  13. Hydration in solution is critical for stable oxygen isotope fractionation between carbonate ion and water

    E-print Network

    Zeebe, Richard E.

    Hydration in solution is critical for stable oxygen isotope fractionation between carbonate ion fractionation factors (a's) between different chemical compounds in thermody- namic equilibrium. Although isotope fractionation between dissolved CO2À 3 and H2O (hereafter aðCO2À 3 ­H2OÞ). Simple force field

  14. On the solution of the carbonate chemistry system in ocean biogeochemistry models

    Microsoft Academic Search

    Michael J. Follows; Taka Ito; Stephanie Dutkiewicz

    2006-01-01

    We present a simplified method for solving the local equilibrium carbonate chemistry in numerical ocean biogeochemistry models. Compared to the methods typically used, the scheme is fast, efficient and compact. The accuracy of the solution is dictated by the number of species retained in the expression for alkalinity and there is almost no computational penalty for retaining minor contributions. We

  15. Solution-processed single-walled carbon nanotube field effect transistors and bootstrapped inverters for disintegratable, transient electronics

    E-print Network

    Rogers, John A.

    Solution-processed single-walled carbon nanotube field effect transistors and bootstrapped field effect transistors based on single-walled carbon nanotube network and formed on a gold transistors with single­walled­carbon nanotube network on flexible substrate J. Appl. Phys. 114, 214504 (2013

  16. Precipitation of calcium carbonate in aqueous solutions in presence of ethylene glycol and dodecane.

    NASA Astrophysics Data System (ADS)

    Natsi, Panagiota D.; Rokidi, Stamatia; Koutsoukos, Petros G.

    2015-04-01

    The formation of calcium carbonate (CaCO3) in aqueous supersaturated solutions has been intensively studied over the past decades, because of its significance for a number of processes of industrial and environmental interest. In the oil and gas production industry the deposition of calcium carbonate affects adversely the productivity of the wells. Calcium carbonate scale deposits formation causes serious problems in water desalination, CO2 sequestration in subsoil wells, in geothermal systems and in heat exchangers because of the low thermal coefficient of the salt. Amelioration of the operational conditions is possible only when the mechanisms underlying nucleation and crystal growth of calcium carbonate in the aqueous fluids is clarified. Given the fact that in oil production processes water miscible and immiscible hydrocarbons are present the changes of the dielectric constant of the fluid phase has serious impact in the kinetics of calcium carbonate precipitation, which remains largely unknown. The problem becomes even more complicated if polymorphism exhibited by calcium carbonate is also taken into consideration. In the present work, the stability of aqueous solutions supersaturated with respect to all calcium carbonate polymorphs and the subsequent kinetics of calcium carbonate precipitation were measured. The measurements included aqueous solutions and solutions in the presence of water miscible (ethylene glycol, MEG) and water immiscible organics (n-dodecane). All measurements were done at conditions of sustained supersaturation using the glass/ Ag/AgCl combination electrode as a probe of the precipitation and pH as the master variable for the addition of titrant solutions with appropriate concentration needed to maintenance the solution supersaturation. Initially, the metastable zone width was determined from measurements of the effect of the solution supersaturation on the induction time preceding the onset of precipitation at free-drift conditions. The rates of crystal growth were measured as a function of the solution supersaturation using the highly accurate and reproducible methodology of constant supersaturation. The dependence of the rates of crystal growth on supersaturation suggested surface diffusion controlled mechanism. At constant supersaturation it was possible to extend the time period for the growth of the initially forming polymorph, in a way that sufficient amount is precipitated for characterization with X-ray diffraction (XRD). Moreover, scanning electron microscopy (SEM) was used for the characterization of the morphology of the precipitated solid. In all cases and depending on the solution supersaturation vaterite formed first from solutions of high supersaturation while at low supersaturations calcite formed exclusively. The presence of dodecane reduced the stability of the supersaturated solutions with the crystals forming at the oil-water interface. The presence of ethylene glycol (concentrations between 10-80%) also affected the stability and the kinetics of calcium carbonate precipitation. The morphology of the formed crystals showed habit modifications: Spherical formations consisting of aggregated nanocrystals and calcite crystals with profound pits on the faces were the characteristic feature in the presence of dodecane. ACKNOWLEDGMENT This research was partially funded by the European Union (European Social Fund-ESF) and Greek National Funds through the Operational program Education and Lifelong Learning under the action Aristeia II( Code No 4420).

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

    PubMed Central

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

    2012-01-01

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

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

    SciTech Connect

    Afanasiev, Pavel, E-mail: pavel.afanasiev@ircelyon.univ-lyon1.fr

    2014-05-01

    Molybdenum sulfide nanoparticles have been prepared from the reflux solution reaction involving ammonium heptamolybdate and elemental sulfur in propylene carbonate. Addition to the reaction mixture of starch as a natural capping agent leads to lesser agglomeration and smaller size of the particles. Nanoparticles of MoS{sub x} (x?4) of 10–30 nm size are highly divided and form stable colloidal suspensions in organic solvents. Mo K edge EXAFS of the amorphous materials shows rapid exchange of oxygen to sulfur in the molybdenum coordination sphere during the solution reaction. Thermal treatment of the amorphous sulfides MoS{sub x} under nitrogen or hydrogen flow at 400 °C allows obtaining mesoporous MoS{sub 2} materials with very high pore volume and specific surface area, up to 0.45 cm{sup 3}/g and 190 m{sup 2}/g, respectively. The new materials show good potential for the application as unsupported hydrotreating catalysts. - Graphical abstract: Solution reaction in propylene carbonate allows preparing weakly agglomerated molybdenum sulfide with particle size 20 nm and advantageous catalytic properties. - Highlights: • Solution reaction in propylene carbonate yields MoS{sub x} particles near 20 nm size. • Addition of starch as capping agent reduces particles size and hinder agglomeration. • EXAFS at Mo K edge shows rapid oxygen to sulfur exchange in the solution. • Thermal treatment leads to MoS{sub 2} with very high porosity and surface area.

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

    DOEpatents

    Rau, Gregory Hudson

    2014-07-01

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

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

    SciTech Connect

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

    2010-01-01

    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.

  1. Wash water waste pretreatment system

    NASA Technical Reports Server (NTRS)

    1977-01-01

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

  2. Physical solubility of hydrogen sulfide and carbon dioxide in alkanolamine solutions

    SciTech Connect

    Abu-Arabi, M.K.

    1988-01-01

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

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

    SciTech Connect

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

    1985-01-01

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

  4. Adsorption of cadmium and lead onto oxidized nitrogen-doped multiwall carbon nanotubes in aqueous solution: equilibrium and kinetics

    Microsoft Academic Search

    Nancy Veronica Perez-Aguilar; Emilio Muñoz-Sandoval; Paola Elizabeth Diaz-Flores; Jose Rene Rangel-Mendez

    2010-01-01

    Nitrogen-doped multiwall carbon nanotubes (CNx) were chemically oxidized and tested to adsorb cadmium and lead from aqueous\\u000a solution. Physicochemical characterization of carbon nanotubes included morphological analysis, textural properties, and chemical\\u000a composition. In addition, the cadmium adsorption capacity of oxidized-CNx was compared with commercially available activated\\u000a carbon and single wall carbon nanotubes. Carboxylic and nitro groups on the surface of oxidized

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

    PubMed

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

    2014-04-01

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

  6. 3DRISM Bridge Functional for the Aqueous Solutions of Carbon Nanomaterials

    E-print Network

    Volodymyr P. Sergiievskyi

    2011-12-05

    In the paper a bridge functional for the closure relation of the three-dimensional reference interaction model (3DRISM) equations is proposed. The effectiveness of the bridge for the aqueous solutions of the carbon nanomaterials is tested. In the paper two classes of systems are investigated: (i) infinitely diluted aqueous solutions of the Lennard-Jones (LJ) spheres and (ii) infinitely diluted aqueous solution of the carbon nanotubes(CNT). The bridge functional is fitted to the molecular simulation data. It is shown that for all the investigated systems the bridge functional can be approximated by the exponential function which depends only on the solute/solvent size ratio. It is shown that by using the proposed bridge functional is possible (i) to predict accurately the position of the first peak of the water oxygen density distribution function (DDF) around the solute, (ii) to improve the accuracy of the predictions of the first peak's height of the water oxygen DDF around the solute (iii), to predict correctly the water hydrogen DDF behavior in the vicinity of the CNT.

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

    SciTech Connect

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

    1991-09-01

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

  8. Single Wall Carbon Nano Tube Films and Coatings

    Microsoft Academic Search

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

    2002-01-01

    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

  9. Precipitates on granular iron in solutions containing calcium carbonate with trichloroethene and hexavalent chromium.

    PubMed

    Jeen, Sung-Wook; Jambor, John L; Blowes, David W; Gillham, Robert W

    2007-03-15

    Mineralogical examination, using scanning electron microscopy (SEM), X-ray diffractometry (XRD), and optical microscopy, was conducted on the Fe0-bearing reactive materials derived from long-term column experiments undertaken to assess the treatment capacity of Fe0 under different geochemical conditions. The columns received either deionized water or solutions of differing dissolved calcium carbonate concentrations, together either with trichloroethene (TCE) or hexavalent chromium (Cr(VI)). The major reaction product in the columns receiving deionized water was magnetite-maghemite, and for the columns receiving dissolved calcium carbonate, the main products were iron hydroxy carbonate and aragonite. Replacement of Fe0 by reaction products occurred mainly at the edges of the Fe0 particles, and penetrative replacement was focused along cracks and along and around graphitic inclusions. Fibrous or flake-shaped iron hydroxy carbonate mostly replaced the edges of the Fe0 particles. Aragonite had needle-shaped morphology, and some occurred as clusters of crystals. Aragonite was deposited on iron hydroxy carbonate, thus providing at least a partial armoring effect. The mineral was also observed to cement groups of Fe0 particles into compact aggregates. The Cr was present mostly as Cr(III) in Cr(III)-Fe(III) (oxy)hydroxides and in trace amounts in iron hydroxy carbonate. PMID:17410795

  10. Solution Ionic Strength Engineering as a Generic Strategy to Coat Graphene Oxide (GO)

    E-print Network

    Zhou, Chongwu

    particles were washed with ethanol and water, and dispersed into to an aqueous solution. Ball-milled silicon particle synthesis Ball-milled silicon particles were obtained by ball-milling metallurgical silicon powder measurements To prepare the working electrodes, various sulfur-based materials were mixed with carbon black

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

    Microsoft Academic Search

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

    2007-01-01

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

  12. Determination of electronic states of individually dissolved ( n, m) single-walled carbon nanotubes in solution

    NASA Astrophysics Data System (ADS)

    Tanaka, Yasuhiko; Hirayama, Kohei; Niidome, Yasuro; Nakashima, Naotoshi

    2009-11-01

    Solution redox chemistry is useful to understand the chirality-dependent electronic properties of single-walled carbon nanotubes (SWNTs). We have found that the electron transfer reactions of sodium dithionite with SWNTs cause photoluminescence (PL) quenching processes of 14 individually dissolved SWNTs in an aqueous micellar solution. Based on the analysis using the Nernst equation for the PL change, we have determined the conduction band ( c1) levels of the 14 isolated SWNTs. We have also estimated the valence band ( ?1) levels as well as the Fermi levels of the SWNTs using the reported bandgap values of the corresponding isolated SWNTs.

  13. Cold fusion by electrolysis in a light water-potassium carbonate solution with a nickel electrode

    SciTech Connect

    Notoya, Reiko (Hokkaido Univ., Kitaku, Sapporo (Japan))

    1993-09-01

    The evolution of a large amount of heat, unexplainable by ordinary chemical reactions, was observed in an electrolytic cell with a nickel cathode and a platinum anode in a potassium carbonate-light water solution. The nickel cathode had a specially designed porous structure, based on fundamental knowledge concerning the active hydrogen electrode in alkaline solutions. An increase in the concentration of calcium ions was observed in the electrolyte, which seems to be the result of potassium-hydrogen cold fusion. 5 refs., 4 figs.

  14. High-performance field effect transistors from solution processed carbon nanotubes.

    PubMed

    Wang, Huiliang; Luo, Jun; Robertson, Alex; Ito, Yasuhiro; Yan, Wenjing; Lang, Volker; Zaka, Mujtaba; Schäffel, Franziska; Rümmeli, Mark H; Briggs, G Andrew D; Warner, Jamie H

    2010-11-23

    Nanoelectronic field effect transistors (FETs) are produced using solution processed individual carbon nanotubes (CNTs), synthesized by both arc discharge and laser ablation methods. We show that the performance of solution processed FETs approaches that of CVD-grown FETs if the nanotubes have minimal lattice defects and are free from surface contamination. This is achieved by treating the nanotubes to a high-temperature vacuum annealing process and using 1,2-dichloroethane for dispersion. We present CNT FETs with mobilities of up to 3546 cm(2)/(V s), transconductance of 4.22 ?S, on-state conductance of 9.35 ?S and on/off ratios as high as 10(6). High-resolution transmission electron microscopy is used to examine the presence of catalyst particles and amorphous carbon on the surface and Raman spectroscopy is used to examine the lattice defects, both of which lead to reduced device performance. PMID:20958015

  15. Removal of insecticide carbofuran from aqueous solutions by banana stalks activated carbon.

    PubMed

    Salman, J M; Hameed, B H

    2010-04-15

    In this work, activated carbon was prepared from banana stalks (BSAC) waste to remove the insecticide carbofuran from aqueous solutions. The effects of contact time, initial carbofuran concentration, solution pH and temperature (30, 40 and 50 degrees C) were investigated. Adsorption isotherm, kinetics and thermodynamics of carbofuran on BSAC were studied. Equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherm models and the data best represented by the Langmuir isotherm. Thermodynamic parameters such as standard enthalpy (DeltaH(o)), standard entropy (DeltaS(o)) and standard free energy (DeltaG(o)) were evaluated. Regeneration efficiency of spent BSAC was studied using ethanol as a solvent. The efficiency was found to be in the range of 96.97-97.35%. The results indicated that the BSAC has good regeneration and reusability characteristics and can be used as alternative to present commercial activated carbon. PMID:20031311

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

    SciTech Connect

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

    1996-12-31

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

  17. Molecular speciation and mesoscale clustering in formaldehyde-methanol-water solutions in the presence of sodium carbonate.

    PubMed

    Gaca, Katarzyna Z; Parkinson, John A; Sefcik, Jan

    2013-09-12

    Nanoporous organic gels can be synthesized from aqueous solutions of formaldehyde and resorcinol in the presence of basic electrolytes such as sodium carbonate. It is well known that formaldehyde is present in the form of methylene glycols or methoxy-glycols in aqueous and methanolic solutions, but influence of pH or electrolytes on speciation in these solutions has not been previously studied. Here we investigated effects of sodium carbonate on the speciation and colloidal scale clustering in formaldehyde-methanol-water solutions in the absence of resorcinol. We used (13)C NMR spectroscopy to quantitatively characterize molecular speciation in solutions and to estimate corresponding equilibrium constants for glycol dimerization and methoxylation. We found that species distribution is essentially independent of carbonate concentration for pH values between 3.4 (no carbonate) and 10.6. This was also consistent with ATR IR measurements of the same solutions. However, NMR spin-spin relaxation time measurements showed an unexpected behavior for glycols and especially for diglycol (but not for methanol), with relaxation times strongly decreasing with increasing carbonate concentration, indicating differences in local molecular environment of glycols. We further used dynamic light scattering to confirm the presence of mesoscale clustering in formaldehyde-methanol-water (for both H2O and D2O) solutions in the presence of sodium carbonate. We propose that the observed phenomena are due to glycol-rich cluster mesospecies in equilibrium bulk solution, together forming a thermodynamically stable mesostructured liquid phase. PMID:23964642

  18. Initiation of stress corrosion cracking for pipeline steels in a carbonate-bicarbonate solution

    Microsoft Academic Search

    Z. F. Wang; A. Atrens

    1996-01-01

    The linearly increasing stress test (LIST) was used to study the stress corrosion cracking (SCC) behavior of a range of pipeline\\u000a steels in carbonate-bicarbonate solution under stress rate control at different applied potentials. Stress corrosion cracking,\\u000a at potentials below -800 mV(SCE), was attributed to hydrogen embrittlement. Stress corrosion cracking, in the potential range\\u000a from about-700 to -500 mV(SCE), was attributed

  19. Explicit solution of the radial breathing mode frequency of single-walled carbon nanotubes

    Microsoft Academic Search

    Tienchong Chang

    2007-01-01

    On the basis of a molecular mechanics model, an analytical solution of the radial breathing mode (RBM) frequency of single-walled\\u000a carbon nanotubes (SWCNTs) is obtained. The effects of tube chirality and tube diameter on the RBM frequency are investigated\\u000a and good agreement between the present results and existing data is found. The present analytical formula indicates that the\\u000a chirality and

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

    Microsoft Academic Search

    K. Kadirvelu; C. Namasivayam

    2003-01-01

    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

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

    Microsoft Academic Search

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

    2007-01-01

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

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

    Microsoft Academic Search

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

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

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

    SciTech Connect

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

    1980-06-01

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

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

    SciTech Connect

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

    1981-04-01

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

  5. Preparation and characterization of poly(propylene carbonate)\\/montmorillonite nanocomposites by solution intercalation

    Microsoft Academic Search

    Xudong Shi; Zhihua Gan

    2007-01-01

    Poly(propylene carbonate) (PPC) is a new biodegradable aliphatic polycarbonate. However, the poor thermal stability and low glass transition temperatures (Tg) have limited its applications. To improve the thermal properties of PPC, organophilic montmorillonite (OMMT) was mixed with PPC by a solution intercalation method to produce nanocomposites. An intercalated-and-flocculated structure of PPC\\/OMMT nanocomposites was confirmed by X-ray diffraction (XRD) and transmission

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

    SciTech Connect

    Philip E. Zapp; John W. Van Zee

    2002-02-01

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

  7. Sorption of divalent metal ions from aqueous solution by carbon nanotubes: A review

    Microsoft Academic Search

    Gadupudi Purnachadra Rao; Chungsying Lu; Fengsheng Su

    2007-01-01

    In this article, the technical feasibility of various kinds of raw and surface oxidized carbon nanotubes (CNTs) for sorption of divalent metal ions (Cd2+, Cu2+, Ni2+, Pb2+, Zn2+) from aqueous solution is reviewed. The sorption mechanisms appear mainly attributable to chemical interactions between the metal ions and the surface functional groups of the CNTs. The sorption capacities of CNTs remarkably

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

    E-print Network

    Cordi, Eric Marshall

    1991-01-01

    used for this project was generously donated by Texaco Chemical Company. TABLE OF CONTENTS CHAFER Page I INTRODUCTION II LITERATURE REVIEW Gas Sweetening Technology. Physical Pmperties of MDEA, Chemical Reactions in the MDEA Process... containing acidic impurities, such as carbon dioxide (COz) and hydrogen sulfide (HzS), has continued to evolve over several decades. R. R. Bottoms obtained the first patent in 1930 for the treatment of natural gas with a liquid alkanolamine solution. Since...

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

    Microsoft Academic Search

    Luca Cecchinato; Marco Corradi; Ezio Fornasieri; Lorenzo Zamboni

    2005-01-01

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

  10. Studies on adsorption of mercury from aqueous solution on activated carbons prepared from walnut shell

    Microsoft Academic Search

    M. Zabihi; A. Haghighi Asl; A. Ahmadpour

    2010-01-01

    The adsorption ability of a powdered activated carbons (PAC) derived from walnut shell was investigated in an attempt to produce more economic and effective sorbents for the control of Hg(II) ion from industrial liquid streams. Carbonaceous sorbents derived from local walnut shell, were prepared by chemical activation methods using ZnCl2 as activating reagents. Adsorption of Hg(II) from aqueous solutions was

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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.

  12. Surfactant-enhanced in-situ soils washing. Final report, March 1985-April 1986

    SciTech Connect

    Nash, J.; Traver, R.P.; Downey, D.C.

    1987-09-01

    The objective of this joint Air Force - Environmental Protection Agency project was to demonstrate the feasibility of using surfactants to enhance the washing of petroleum and solvent-contaminated soils. A pilot-scale test of in-situ soils washing was performed at an abandoned fire training area using several surfactant solutions. The results of this study did not show in-situ soils washing as a proven and reliable remediation technology. Several shortfalls were observed and are documented in this report. The report also contains information on the operation of a groundwater treatment system which were successfully used to decontaminate highly polluted groundwater at the site.

  13. Conductivity of carbon nanofiber\\/polypyrrole conducting nanocomposites

    Microsoft Academic Search

    Cheol Kim; Shuai Zhang

    2009-01-01

    Carbon nanofiber (CNF) \\/ Polypyrrole (Ppy) composite materials were fabricated by two newly invented processes - filtering,\\u000a washing and drying the mixture of CNF dispersion and Ppy-NMP solution (FWP process) and heating an aqueous solution of CNF\\u000a (SH process). CNF\\/Ppy composite materials have never been reported before in any other research papers. Conductivities of\\u000a the composite films were obtained by

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

    PubMed

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

    2015-01-23

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

  15. Solid/solution interaction: the effect of carbonate alkalinity on adsorbed thorium

    SciTech Connect

    LaFlamme, B.D.; Murray, J.W.

    1987-02-01

    Elevated activities of dissolved Th have been found in Soap Lake, an alkaline lake in Eastern Washington. Dissolved /sup 232/Th ranges from less than 0.001 to 4.9 dpm/L compared to about 1.3 x 10/sup -5/ dpm/L in sea water. The enhanced activity in the lake coincides with an increase in carbonate alkalinity. Experiments were conducted to evaluate the effect of pH, ionic strength and carbonate alkalinity on Th adsorption on goethite. Thorium (10/sup -13/ M total) in the presence of 5.22 mg/L ..cap alpha..-FeOOH and 0.1 M NaNO/sub 3/ has an adsorption edge from pH 2-5. At pH 9.0 +/- 0.6 the percent Th absorbed on the solid began to decrease from 100% at 100 meq/L carbonate alkalinity and exhibited no adsorption above 300 meq/L. The experimental data were modeled to obtain the intrinsic adsorption equilibrium constants for Th hydrolysis species. These adsorption constants were incorporated in the model to interpret the observed effect of carbonate alkalinity on Th adsorption. There are two main effects of the alkalinity. To a significant degree the decrease in Th adsorption is due to competition of HCO/sub 3//sup -/ and CO/sub 3//sup 2 -/ ions for surface sites. Dissolved Th carbonate complexes also contribute to the increase of Th in solution.

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    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

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

    PubMed

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

    2012-10-30

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

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

    PubMed

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

    2015-01-27

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Wash water solids removal system study

    NASA Technical Reports Server (NTRS)

    1974-01-01

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

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

    PubMed

    Cossu, Raffaello; Lai, Tiziana; Pivnenko, Kostyantyn

    2012-03-15

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

  2. Adsorbents from lignin and washed-off petroleum waste

    Microsoft Academic Search

    T. G. Shendrik; L. V. Pashchenko; V. V. Simonova; V. A. Drozdov; V. A. Kucherenko; T. V. Khabarova

    2007-01-01

    The properties of active carbons, products of the steam activation (400–900C) of mixtures of washed-off petroleum waste and\\u000a lignin, were studied. The dependences of the yield, the specific surface area, and adsorption activity with respect to iodine\\u000a (A\\u000a I) and methylene blue (A\\u000a MB) on the activation temperature (400–900C), as well as the characteristics of the pore systems and the

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

    Microsoft Academic Search

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

    2002-01-01

    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,

  4. Preparation and utilization of sludge-based activated carbon for the adsorption of dyes from aqueous solutions

    Microsoft Academic Search

    Wen-Hong Li; Qin-Yan Yue; Bao-Yu Gao; Zuo-Hao Ma; Yan-Jie Li; Hai-Xia Zhao

    2011-01-01

    Sludge-based activated carbon (SAC) was prepared from paper mill sewage sludge by carbonization at low temperature followed by physical activation with steam in this study and the utilization of SAC in removing Methylene Blue (MB) and Reactive Red 24 (RR 24) from aqueous solutions was investigated. SAC was characterized by iodine number, specific surface area, zeta potential, scanning electron microscope

  5. Utilization of Guava Seeds as a Source of Activated Carbon for Removal of Methylene Blue from Aqueous Solution

    Microsoft Academic Search

    I. A. Rahman; B. Saad

    Guava seeds have been used as a raw material to produce activated carbon. Dried, milled, guava seeds were activated by pyrolysis at temperature up to 700 o C, and by using zinc chloride as chemical activation agent. The adsorption capacity was demonstrated by the isotherms of methylene blue from aqueous solution. Pyrolysis alone yields a poor adsorbing carbon with adsorbing

  6. Wash water waste pretreatment system study

    NASA Technical Reports Server (NTRS)

    1976-01-01

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

  7. 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...

  8. Adsorption of Direct Blue 53 dye from aqueous solutions by multi-walled carbon nanotubes and activated carbon.

    PubMed

    Prola, Lizie D T; Machado, Fernando M; Bergmann, Carlos P; de Souza, Felipe E; Gally, Caline R; Lima, Eder C; Adebayo, Matthew A; Dias, Silvio L P; Calvete, Tatiana

    2013-11-30

    Multi-walled carbon nanotubes (MWCNT) and powder activated carbon (PAC) were used as adsorbents for adsorption of Direct Blue 53 dye (DB-53) from aqueous solutions. The adsorbents were characterised using Raman spectroscopy, N2 adsorption/desorption isotherms, and scanning and transmission electron microscopy. The effects of initial pH, contact time and temperature on adsorption capacity of the adsorbents were investigated. At pH 2.0, optimum adsorption of the dye was achieved by both adsorbents. Equilibrium contact times of 3 and 4 h were achieved by MWCNT and PAC adsorbents, respectively. The general order kinetic model provided the best fit of the experimental data compared to pseudo-first order and pseudo-second order kinetic adsorption models. For DB-53 dye, the equilibrium data (298-323 K) were best fitted to the Sips isotherm model. The maximum sorption capacity for adsorption of the dye occurred at 323 K, with the values of 409.4 and 135.2 mg g(-1) for MWCNT and PAC, respectively. Studies of adsorption/desorption were conducted and the results showed that DB-53 loaded MWCNT could be regenerated (97.85%) using a mixture 50% acetone + 50% of 3 mol L(-1) NaOH. Simulated dye house effluents were used to evaluate the application of the adsorbents for effluent treatment (removal of 99.87% and 97.00% for MWCNT and PAC, respectively, were recorded). PMID:24076517

  9. 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)

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

    2014-03-01

    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).

  10. Laboratory differential simulation design method of pressure absorbers for carbonization of phenolate solution by carbon dioxide in coal-tar processing

    SciTech Connect

    Linek, V.; Sinkule, J.; Moucha, T.; Rejl, J.F. [Prague Institute for Chemical Technology, Prague (Czech Republic). Dept. of Chemical Engineering

    2009-01-15

    A laboratory differential simulation method is used for the design of carbonization columns at coal-tar processing in which phenols are regenerated from phenolate solution by carbon dioxide absorption. The design method is based on integration of local absorption rates of carbon dioxide along the column. The local absorption rates into industrial phenolate mixture are measured in a laboratory model contactor for various compositions of the gas and liquid phases under the conditions that ensure the absorption rates in the laboratory absorber simulate the local rates in the industrial column. On the bases of the calculations, two-step carbonization columns were designed for 30000 t/year of the phenolate solution treatment by carbon dioxide. The absorption proceeds at higher pressure of 500 kPa and temperatures from 50 to 65 C, pure carbon dioxide is used and toluene is added. These conditions have the following favourable effects: (I) significant size reduction of the columns, (ii) it is possible to process more concentrated solutions without danger of silting the columns by crystallization of NaHCO{sub 3} on the packing. (iii) small amount of inert gas is released, (iv) lower alkalinity and better separability of the organic phase (phenols with toluene) from water phase (soda or bicarbonate solution) in separators.

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

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

    PubMed

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

    2014-01-01

    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

  13. Solution-reactor-produced-{sup 99}Mo using activated carbon to remove {sup 131}I

    SciTech Connect

    Kitten, S.; Cappiello, C. [Los Alamos National Lab., NM (United States)

    1998-09-01

    This research explores the idea of producing {sup 99}Mo in a solution reactor. The Solution High Energy Burst Assembly (SHEBA), located at the Los Alamos Critical Assembly Facility, was used to facilitate this study. The goal of this study was to build on work previously completed and to investigate a possible mode of radioactive contaminant removal prior to a {sup 99}Mo extraction process. Prior experiments, performed using SHEBA and a single-step sorption process, showed a significant amount of {sup 131}I present along with the {sup 99}Mo on the alumina that was used to isolate the {sup 99}Mo. A high concentration of {sup 131}I and/or other contaminants present in a sample prohibits the Food and Drug Administration from approving an extraction of that nature for radiopharmaceutical use. However, if it were possible to remove the {sup 131}I and other contaminants prior to a {sup 99}Mo extraction, a simple column extraction process might be feasible. Activated charcoal was used to try to filter the {sup 131}I contaminant from an irradiated fuel solution. Gamma spectroscopy confirmed that the activated carbon trapped a significant amount of the {sup 131}I, as well as notable amounts of {sup 133}Xe, {sup 105}Rb, and {sup 140}Ba. Most importantly, the carbon traps a diminutive amount of {sup 99}Mo.

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

    PubMed Central

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

    2014-01-01

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

  15. Solvation structure of Li+ in concentrated LiPF6-propylene carbonate solutions.

    PubMed

    Kameda, Yasuo; Umebayashi, Yasuhiro; Takeuchi, Munetaka; Wahab, Mohanmmad Abdul; Fukuda, Shuhei; Ishiguro, Shin-ichi; Sasaki, Motoya; Amo, Yuko; Usuki, Takeshi

    2007-06-01

    Time-of-flight neutron diffraction measurements were carried out for 6Li/7Li isotopically substituted 10 mol % LiPF6-propylene carbonate-d6 (PC-d6) solutions, in order to obtain structural information on the first solvation shell of Li+. Structural parameters concerning the nearest neighbor Li+...PC and Li+...PF6- interactions were determined through least-squares fitting analysis of the observed difference function, DeltaLi(Q). It has been revealed that the first solvation shell of Li+ consists in average of 4.5(1) PC molecules with an intermolecular Li+...O(PC) distance of 2.04(1) A. The angle Li+...O=C bond angle has been determined to be 138(2) degrees. PMID:17497919

  16. Effect of microstructure on corrosion of steels in aqueous solutions containing carbon dioxide

    SciTech Connect

    Al-Hassan, S. [Inst. of Paper Science and Technology, Atlanta, GA (United States); Mishra, B.; Olson, D.L. [Colorado School of Mines, Golden, CO (United States); Salama, M.M. [Conoco, Inc., Ponca City, OK (United States)

    1998-06-01

    The influence of microstructure on the corrosion rate of steels in a carbon dioxide (CO{sub 2})-containing aqueous solution was measured experimentally as a function of pH, temperature, and partial pressure of CO{sub 2}. An attempt was made to quantify and relate the microstructure to the corrosion rate. The effect of alloy microstructure was increasingly evident at temperatures up to 60 C but diminished above 60 C. The corrosion rate increased with temperature in the activation-controlled regime, where a nonprotective iron carbonate (FeCO{sub 3}) scale formed. Diffusion-controlled corrosion through a stable scale of iron hydroxycarbonate (Fe{sub 2}[OH]{sub 2}CO{sub 3}) was responsible for lowering the corrosion rate above 60 C. Under a diffusion-controlled corrosion mechanism, microstructure of the steel had no effect on corrosion rate.

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

    PubMed

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

    2014-09-16

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

  18. Carbonation and other super saturated gases as solution modifiers for improved sensitivity in solvent assisted ionization inlet (SAII) and ESI.

    PubMed

    Pagnotti, Vincent S; Chakrabarty, Shubhashis; McEwen, Charles N

    2013-02-01

    Solvent Assisted Ionization Inlet (SAII) produces ions in a heated inlet to a mass spectrometer from aqueous and aqueous/organic solutions with high sensitivity. However, the use of acid modifiers, which typically aids electrospray ionization, generally results in ion suppression in SAII. Here we demonstrate that the use of carbonation and other super-saturated gases as solution modifiers increases analyte ion abundance and reduces metal cation adduction in SAII. Carbonation is also found to enhance electrospray ionization. The mechanistic and practical utility of carbonation in mass spectrometry is addressed. PMID:23296909

  19. Formation of nanostructures from colloidal solutions of silicon dioxide and carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Zhukalin, D. A.; Tuchin, A. V.; Goloshchapov, D. L.; Bityutskaya, L. A.

    2015-02-01

    The formation of nanostructures from colloidal solutions of amorphous silicon dioxide (SiO2) and carbon nanotubes (CNTs) in evaporating drops at room temperature has been studied. It is established that spherical aggregates with an average diameter of ˜2 ?m and rodlike nanostructures with diameters within 250-300 nm and lengths of ˜4 ?m are formed under these conditions. The mechanisms of covalent and van der Waals interaction between CNTs and SiO2 are considered in the framework of a phenomenological model of the active center of a closed CNT.

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

    NASA Astrophysics Data System (ADS)

    Wi?niewski, Marek; Terzyk, Artur P.; Hattori, Yoshiyuki; Kaneko, Katsumi; Okino, Fujio; Kruszka, Bartosz

    2009-11-01

    A new single-step method of multiwalled carbon nanotubes opening is reported. It bases on hydrothermal treatment with H 2O 2 solution, so in this way one reduces energy and water consuming purification process. The efficiency of a new method is compared for the same tubes but opened by the 'typical' procedure using treatment with molten alkaline mixture. The data of low temperature N 2 adsorption and TEM measurements indicate that under specific conditions one can easily open the tubes. Enthalpy of immersion in water measurements are reported showing that application of this new procedure might lead to simultaneous creation of surface oxygen-containing functional groups.

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

    SciTech Connect

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

    2012-05-15

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

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

    SciTech Connect

    NONE

    1996-10-01

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

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

    E-print Network

    Cordi, Eric Marshall

    1991-01-01

    of carbon dioxide in these solutions was slower than predicted, given the amount of free MDEA present. The reduced values of the pseudo-first-order rate constant were tested statistically to cone!ate the rate depression with free MDEA and hydrogen...-away view) . . Page 21 22 4. Two-Film Model of Mass Transfer. . . 32 5. Comparative Arrhenius Plot of Significant CO&/MDEA Research. 6. Pseudo-first-order Rate Constants at 25'C 51 68 7. Free Amine Plot for Pseudo-first-order Rate Constants 69 8...

  4. Effects of the centrifuge drainage method on total organic carbon concentrations in soil solutions from peaty soils

    Microsoft Academic Search

    Ian C. Grieve

    1996-01-01

    This paper investigates the effects of centrifuge speed, time and different filter media at the base of the soil column on the concentrations of total organic carbon (TOO in soil solutions extracted by the centrifuge drainage method. With increasing time at 1000 rev min?1 centrifuge speed, the volume of solution extracted increased as a logistic growth curve, but TOC concentrations

  5. Removal of trihalomethanes from aqueous solution through armchair carbon nanotubes: a molecular dynamics study.

    PubMed

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

    2015-04-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  7. Technical bases DWPF Late Washing Facility

    SciTech Connect

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

    1992-08-10

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

  8. Removal of Copper Ions from Aqueous Solutions via Adsorption on Carbon Nanocomposites.

    PubMed

    Dichiara, Anthony B; Webber, Michael R; Gorman, William R; Rogers, Reginald E

    2015-07-22

    The development of technologies for water purification is critical to meet the global challenges of insufficient water supply and inadequate sanitation. Among all wastewater treatments, adsorption is globally recognized as the most promising method because of its versatility and economic feasibility. Herein, the removal of copper ions (Cu(II)) from aqueous solutions through adsorption on free-standing hybrid papers comprised of a mixture between graphene and different types of carbon nanotubes (CNTs) was examined. Results indicate that the rate of adsorption and long-time capacity of the metal ions on the nanocomposites significantly exceeds that of activated carbon by a factor of 4. Moreover, the combination of graphene with CNTs endows an increase in the uptake of Cu(II) up to 50% compared to that of CNTs alone, with a maximum adsorption capacity higher than 250 mg·g(-1). The removal of Cu(II) from water is sensitive to solution pH, and the presence of oxygen functional groups on the adsorbent surface promotes higher adsorption rates and capacities than pristine materials. These hybrid nanostructures show great promise for environmental remediation efforts, wastewater treatments, and separation applications, and the results presented in this study have important implications for understanding the interactions of carbonaceous materials at environmental interfaces. PMID:26125611

  9. Removal of nickel(II) from aqueous solution using Citrus Limettioides peel and seed carbon.

    PubMed

    Sudha, R; Srinivasan, K; Premkumar, P

    2015-07-01

    The agricultural wastes like Citrus Limettioides peel and seed to be suitable precursor for the preparation of carbon [Citrus Limettioides peel carbon (CLPC) and seed carbon (CLSC)] has been explored in the present work, utilizing sulfuric acid as the activating agent. Adsorption studies were performed by varying contact time, solution pH, adsorbent dose and temperature. The equilibrium time for Ni(II) ions was determined as 4h and optimal pH was 4-7. Surface morphology and functionality of the CLPC and CLSC were characterized by SEM, EDX and FT-IR. The experimental data were analysed using the Freundlich, Langmuir, Temkin, Redlich-Peterson, Sips and Dubinin-Radushkevich adsorption isotherm equations using nonlinear regression analysis. Equilibrium data were found to fit well in the Langmuir isotherm, which confirmed the monolayer coverage of Ni(II) ions. The Langmuir monolayer adsorption capacity of CLPC and CLSC was found to be 38.46 and 35.54mg/g. The thermodynamic parameters indicated that the adsorption process was spontaneous and exothermic in nature. The kinetic data followed pseudo-second order model with film diffusion process. The adsorbents were tested with Ni(II) plating wastewater in connection with the reuse and selectivity of the adsorbents. PMID:25841067

  10. Cryogenic-temperature electron microscopy direct imaging of carbon nanotubes and graphene solutions in superacids.

    PubMed

    Kleinerman, O; Parra-Vasquez, A Nicholas G; Green, M J; Behabtu, N; Schmidt, J; Kesselman, E; Young, C C; Cohen, Y; Pasquali, M; Talmon, Y

    2015-07-01

    Cryogenic electron microscopy (cryo-EM) is a powerful tool for imaging liquid and semiliquid systems. While cryogenic transmission electron microscopy (cryo-TEM) is a standard technique in many fields, cryogenic scanning electron microscopy (cryo-SEM) is still not that widely used and is far less developed. The vast majority of systems under investigation by cryo-EM involve either water or organic components. In this paper, we introduce the use of novel cryo-TEM and cryo-SEM specimen preparation and imaging methodologies, suitable for highly acidic and very reactive systems. Both preserve the native nanostructure in the system, while not harming the expensive equipment or the user. We present examples of direct imaging of single-walled, multiwalled carbon nanotubes and graphene, dissolved in chlorosulfonic acid and oleum. Moreover, we demonstrate the ability of these new cryo-TEM and cryo-SEM methodologies to follow phase transitions in carbon nanotube (CNT)/superacid systems, starting from dilute solutions up to the concentrated nematic liquid-crystalline CNT phases, used as the 'dope' for all-carbon-fibre spinning. Originally developed for direct imaging of CNTs and graphene dissolution and self-assembly in superacids, these methodologies can be implemented for a variety of highly acidic systems, paving a way for a new field of nonaqueous cryogenic electron microscopy. PMID:25818279

  11. Utilizing secondary heat to heat wash oil in the coke-oven gas desulfurization division

    SciTech Connect

    Volkov, E.L.

    1981-01-01

    Removal of hydrogen sulfide from the coke-oven gas by the vacuum-carbonate method involves significant energy costs, comprising about 47% of the total costs of the process. This is explained by the significant demand of steam for regeneration of the wash oil, the cost of which exceeds 30% of the total operating costs. The boiling point of the saturated wash oil under vacuum does not exceed 70/sup 0/C, thus the wash oil entering the regenerator can be heated either by the direct coke-oven gas or by the tar supernatant from the gas collection cycle. Utilizing the secondary heat of the direct coke-oven gas and the tar supernatant liquor (the thermal effect is approximately the same) to heat the wash oil from the gas desulfurization shops significantly improves the industrial economic indices. Heating the wash oil from gas desulfurization shops using the vacuum-carbonate method by the heat of the tar supernatant liquor may be adopted at a number of coking plants which have a scarcity of thermal resources and which have primary coolers with vertical tubes.

  12. Conversion of carbon dissolved in iron powder into a mixture of hydrocarbons and acetone by heating with aqueous alkali metal salt solution

    Microsoft Academic Search

    Fuminori Akiyama

    1995-01-01

    Heating of iron powder containing carbon with aqueous alkali metal salt solution at 300°C gave a mixture of C1?C6 hydrocarbons and acetone. Prolonged reaction of the iron powder with aqueous potassium carbonate solution gave larger amounts of hydrocarbons and acetone than the reaction with aqueous potassium hydroxide solution.

  13. A systematic study and proposed model of the adsorption of binary metal ion solutes in aqueous solution onto activated carbon produced from pecan shells

    Microsoft Academic Search

    Seyed A Dastgheib; David A Rockstraw

    2002-01-01

    Adsorption isotherms of a number of binary solute systems have been obtained. The adsorption behavior of these cations in the presence of other metal ions that display strong or intermediate affinities for adsorption sites has been systematically investigated. In this investigation the following factors have been considered: (1) metal ion site competition; (2) charge accumulation near the carbon surface; and

  14. Removal of naphthalene from recirculated wash oil

    SciTech Connect

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

    1981-09-01

    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.

  15. Crustal solute fluxes and transient carbon dioxide drawdown in the Scottbreen Basin, Svalbard in 2002

    NASA Astrophysics Data System (ADS)

    Krawczyk, Wies?awa Ewa; Bartoszewski, Stefan A.

    2008-12-01

    SummarySolute fluxes and transient carbon dioxide drawdown in a small glacierized basin investigated on Svalbard in 2002 are presented. It was a sample year within a period of significant climate warming in the Arctic. Discharge was recorded in the Scottbreen Basin (10.1 km 2), Bellsund Fjord, between July 8 and September 10, 2002. Specific runoff for this period was 0.784 m, 22% more than the mean for 1986-2001. The runoff for all of 2002 (i.e. the hydrologic year) was estimated by comparison with Bayelva, the only glacial river with longer records on Svalbard. The specific runoff for 2002 was ˜1.228 m, yielding crustal solute fluxes of 69.4 t km -2 yr -1 (25.8 m 3 km -2 yr -1). This rate is the highest chemical denudation rate reported from glacierized basins on Svalbard, and it may be underestimated because higher solute fluxes at the beginning of the melt season were not taken into account. Crustal fluxes in the fall may also have been higher because it is probable that crustal ion concentrations were increasing after recording stopped in September. The cation denudation rate was 1213 ? meq + m -2 yr -1 and the mean annual crustal ion concentration derived from it amounted to 981 ?eq L -1. Transient CO 2 drawdown in 2002 was 5242 kg C km -2 yr -1. Most of the carbon dioxide was removed in the summer ablation waters, estimated CO 2 drawdown in the fall being only 13% of the total. Comparison with crustal solute fluxes (CSF) computed from specific conductivity in the 1980s and 1990s suggests that earlier fluxes may have been overestimated by around 19%. Comparing earlier data with the 2002 rates may confirm the influence of climate warming on increasing chemical denudation rates. It was also found that a globally derived equation relating specific conductivity to concentrations of dissolved limestone in water gave estimates of the crustal solute fluxes that were only 1.1% less than those obtained via comprehensive chemical analyses of waters and ion partitioning procedures.

  16. Basic solutions to carbon\\/carbon oxidation: Science and technology. Final report, 15 April 1993--14 April 1998

    Microsoft Academic Search

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

    1998-01-01

    The goal of this study was to gain a fundamental understanding of the role of boron in carbon oxidation. Boron-doped carbons were synthesized via CVD, ion implantation and high temperature doping are subsequently characterized. It was found that high temperature doped HOPG carbons were ideal for oxidation studies because their surface could be reproduced, their surface structures were determined and

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

    PubMed

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

    2009-12-22

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

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

    PubMed Central

    Yu, Fei; Ma, Jie; Han, Sheng

    2014-01-01

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

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

    SciTech Connect

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

    1992-02-01

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

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

    SciTech Connect

    Goni, S.; Guerrero, A

    2003-01-01

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

  2. Laboratory development of sludge washing and alkaline leaching processes: Test plan for FY 1994

    SciTech Connect

    Rapko, B.M.; Lumetta, G.J.

    1994-07-01

    The US Department of Energy plans to vitrify (as borosilicate glass) the large volumes of high-level radioactive wastes at the Hanford site. To reduce costs, pretreatment processes will be used to reduce the volume of borosilicate glass required for disposal. Several options are being considered for the pretreatment processes: (1) sludge washing with water or dilute hydroxide: designed to remove most of the Na from the sludge, thus significantly reducing the volume of waste to be vitrified; (2) sludge washing plus caustic leaching and/or metathesis (alkaline sludge leaching): designed to dissolve large quantities of certain nonradioactive elements, such as Al, Cr and P, thus reducing the volume of waste even more; (3) sludge washing, sludge dissolution, and separation of radionuclides from the dissolved sludge solutions (advanced processing): designed to remove all radionuclides for concentration into a minimum waste volume. This report describes a test plan for work that will be performed in FY 1994 under the Sludge Washing and Caustic Leaching Studies Task (WBS 0402) of the Tank Waste Remediation System (TWRS) Pretreatment Project. The objectives of the work described here are to determine the effects of sludge washing and alkaline leaching on sludge composition and the physical properties of the washed sludge and to evaluate alkaline leaching methods for their impact on the volume of borosilicate glass required to dispose of certain Hanford tank sludges.

  3. Oleic acid adsorption-desorption isotherms on the surface of high-dispersity ferrites from a solution in carbon tetrachloride

    NASA Astrophysics Data System (ADS)

    Balmasova, O. V.; Korolev, V. V.; Yashkova, V. I.

    2010-01-01

    The equilibrium adsorption method was used to comparatively study the adsorption-desorption isotherms of oleic acid on the surfaces of manganese and copper ferrites from a solution in carbon tetrachloride. The adsorption isotherms of the fatty acid were described in terms of the theory of volume filling of micropores. The theory was used to calculate the limiting adsorption values, characteristic energy, and porous space volumes. The isotherm of oleic acid adsorption on the surface of manganese ferrite from a solution in carbon tetrachloride was similar to the isotherms of fatty acid adsorption from solutions in heptane, whereas the isotherm of adsorption on the surface of copper ferrite was similar to the isotherms of fatty acid adsorption from hexane. The limiting adsorption from carbon tetrachloride was higher on the surface of manganese ferrite than on the surface of copper ferrite. The adsorption-desorption isotherms contained hysteresis loops.

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

    Microsoft Academic Search

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

    1998-01-01

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

  5. Isothermal studies of adsorption of acenaphthene from aqueous solution onto activated carbon produced from rice (Oryza sativa) husk

    Microsoft Academic Search

    Abass Olanrewaju Alade; Omotayo Sarafadeen Amuda; Asiata Omotayo Ibrahim

    2012-01-01

    Rice husk (RH), which is an agricultural waste material of environmental impact, was carbonized at 300–600°C in an oven for 2?h, after which its adsorption capacities were investigated for the adsorption of acenaphthene in synthetic aqueous solution with various concentrations (50–150?mg\\/L). The yields of carbon obtained from the raw RH ranged from 20 to 40% (w\\/w), while the adsorption capacities

  6. Wash your hands. water and soap.

    E-print Network

    of hot water for 1 or 2 minutes. · Do not use a microwave to heat formula. It can get too hot and burnSTEP 1 Wash your hands. · Use warm water and soap. · Scrub hands and fingernails for at least 20! · Scrub them in hot soapy water, rinse, and let air dry, OR · Boil them in water 5 minutes and let air dry

  7. Recycled Wash Water Crushed Returned Concrete

    E-print Network

    1 Recycled Wash Water Crushed Returned Concrete National Concrete Consortium March 2012 Colin Lobo% increase by 2030 "Waste" to "Recycled" Returned Concrete - estimated 2 - 10% of production 8 to 12 by 2030 Recycled content: 200% increase by 2020 400% increase by 2030 Recycled Content: Where are we

  8. An Alternative Antimicrobial Commercial Egg Washing Procedure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Presently, commercial eggs are washed with water containing an alkali detergent at approximately pH 11 followed by a chlorine rinse. At this pH, it is likely that there is little, if any, free chlorine in the final rinse to act as an antimicrobial against pathogens like Salmonella. Using a chlorine ...

  9. WASH-DOWN MODULAR PUMP DRIVES

    E-print Network

    Kleinfeld, David

    WASH-DOWN MODULAR PUMP DRIVES Model Nos. 7552-70 7552-75 ® ® WARRANTY Use only MASTERFLEX precision tubing with MASTERFLEX pumps to ensure optimum performance. Use of other tubing may void applicable/S® compati- ble pump head provide variable-flow fluid transfer. The motor and controller can be mounted

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

    EPA Science Inventory

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

  11. Petroleum-base washing and preservative fluid

    Microsoft Academic Search

    T. I. Belova; E. S. Churshukov; L. P. Maiko; N. N. Zakharova

    1984-01-01

    This article reports on an investigation of the feasibility of formulating a wash\\/preservative fluid from commercial materials already produced in the USSR. Technological advances in the production and maintenance of vehicles, machinery, and mechanisms have raised the quality requirements of materials used to remove contaminants from machine parts in the course of manufacture and service and to protect the parts

  12. Petroleum-base washing and preservative fluid

    SciTech Connect

    Belova, T.I.; Churshukov, E.S.; Maiko, L.P.; Zakharova, N.N.

    1984-01-01

    This article reports on an investigation of the feasibility of formulating a wash/preservative fluid from commercial materials already produced in the USSR. Technological advances in the production and maintenance of vehicles, machinery, and mechanisms have raised the quality requirements of materials used to remove contaminants from machine parts in the course of manufacture and service and to protect the parts from atmospheric corrosion between operations. It is determined that it is impossible to formulate a fluid with the required level of detergency, waterdisplacing properties, and protective properties by diluting commercial preservative materials with organic solvents. A wash/preservative fluid is proposed which is composed of an alkenylsuccinic acid (KAP-25) corrosion inhibitor and an alkenylsuccinimide of urea (SIU) additive. Joint use of these inhibitors gives a synergistic effect in the protective properties, the maximum of which in organic solvents is reached at a 1:1 ratio. A comparison of the proposed wash/preservative fluid with an analogous non-USSR formulation showed that the two fluids have equivalent capabilities for removing organic contaminants from metal surfaces. It is concluded that the developed fluid can be used in the washing and interoperational protection of highprecision parts, or mechanisms with enclosed sections and pairs.

  13. TANK 4 CHARACTERIZATION, SETTLING, AND WASHING STUDIES

    Microsoft Academic Search

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

    2009-01-01

    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

  14. FIELD STUDIES OF IN SITU SOIL WASHING

    EPA Science Inventory

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

  15. Washing of the AW-101 entrained solids

    SciTech Connect

    GJ Lumetta

    2000-03-31

    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.

  16. What Happens at a Car Wash?

    ERIC Educational Resources Information Center

    Gallick, Barbara; Lee, Lisa

    2010-01-01

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

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

    NASA Technical Reports Server (NTRS)

    1984-01-01

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

  18. Pd-loaded carbon felt as the cathode for selective dechlorination of 2,4-dichlorophenoxyacetic acid in aqueous solution

    SciTech Connect

    Tsyganok, A.I.; Yamanaka, Ichiro; Otsuka, Kiyoshi [Tokyo Inst. of Tech. (Japan). Dept. of Chemical Engineering

    1998-11-01

    Electrocatalytic reductive dehalogenation of 2,4-dichlorophenoxyacetic acid (2,4-D) to phenoxyacetic acid in aqueous solution containing MeOH, trifluoroacetic acid, and tetraalkylammonium salt was studied. A Teflon-made two-compartment flow-through cell with a permeable carbon felt cathode and a platinum foil anode was employed. Several noble metals were tested as electrocatalysts. Palladium-loaded carbon felt was found to be the most suitable significantly enhanced its electrocatalytic activity toward 2,4-D dechlorination. The reaction was hypothesized to proceed at carbon-palladium interface areas through 4-chlorine cleavage to form 2-chlorophenoxyacetic acid as the main reaction intermediate.

  19. Ion-molecule interactions in solutions of lithium perchlorate in propylene carbonate + diethyl carbonate mixtures: an IR and molecular orbital study.

    PubMed

    Wang, Jianji; Wu, Yanping; Xuan, Xiaopeng; Wang, Hanqing

    2002-08-01

    FTIR spectra have been recorded and analyzed for solutions of lithium perchlorate in propylene carbonate (PC), diethyl carbonate (DEC), and PC + DEC mixtures. It has been shown that the carbonyl stretch bands for PC and DEC are very sensitive to the interaction between Li+ and the solvent molecules. They split with addition of LiClO4, indicating a strong interaction of Li+ with PC and DEC through the oxygen group of PC and both oxygen and ether oxygen atoms of DEC. In conjunction with molecular orbital calculation, the optimized geometries of solvation are given. In addition, solvent separated ion pairs and contact ion pairs were observed in LiClO4/DEC solutions, and no preferential solvation of Li+ in LiClO4/PC + DEC solutions were detected. PMID:12212734

  20. Effects of Prolonged Washing on Primary and Secondary Transport Processes at the Plasma Membrane in Red Beet Storage Tissue.

    PubMed

    Marvier, A. C.; Williams, L. E.; Leigh, R. A.; Hall, J. L.

    1997-09-01

    Changing patterns of enzyme activity and solute transport in response to washing were investigated in red beet (Beta vulgaris L.) storage tissue. Washing had a pronounced effect on the plasma membrane (PM) H+-ATPase with an increase in both hydrolytic and proton-pumping activities. Immunoblotting indicated that this may be due, in part, to a higher amount of this enzyme in the PM of washed tissue. Activities of the tonoplast (V)H+-ATPase and pyrophosphatase fluctuated during a 4-d washing period, but overall showed no marked change in activity. In tissue discs sucrose (Suc), glucose (Glc), and fructose uptakes increased significantly in response to washing. Cycloheximide, cordycepin, and tunicamycin inhibited both Glc- and Suc-inducible uptake. Monensin also strongly inhibited inducible Glc uptake, but the effect on Suc was less marked. N-Ethylmaleimide inhibited both Suc and Glc uptake, with its effects being more pronounced in fresh tissue. Other protein-modifying reagents showed no significant difference in their level of inhibition between fresh and washed tissue. Transport studies, carried out using energized PM vesicles from fresh and washed tissue, indicated that there was no rise in Suc and Glc uptake rates in response to washing. Results with a range of inhibitors indicated that there was no marked change in transporter sensitivity in vesicles isolated from fresh and washed tissue. The results indicate that the well-described enhancement of solute transport in washed storage tissue may be due to an increased PM H+-ATPase activity rather than to changes in PM carrier activity or to changes in metabolism such as invertase activity. PMID:12223806

  1. Effects of Prolonged Washing on Primary and Secondary Transport Processes at the Plasma Membrane in Red Beet Storage Tissue.

    PubMed Central

    Marvier, A. C.; Williams, L. E.; Leigh, R. A.; Hall, J. L.

    1997-01-01

    Changing patterns of enzyme activity and solute transport in response to washing were investigated in red beet (Beta vulgaris L.) storage tissue. Washing had a pronounced effect on the plasma membrane (PM) H+-ATPase with an increase in both hydrolytic and proton-pumping activities. Immunoblotting indicated that this may be due, in part, to a higher amount of this enzyme in the PM of washed tissue. Activities of the tonoplast (V)H+-ATPase and pyrophosphatase fluctuated during a 4-d washing period, but overall showed no marked change in activity. In tissue discs sucrose (Suc), glucose (Glc), and fructose uptakes increased significantly in response to washing. Cycloheximide, cordycepin, and tunicamycin inhibited both Glc- and Suc-inducible uptake. Monensin also strongly inhibited inducible Glc uptake, but the effect on Suc was less marked. N-Ethylmaleimide inhibited both Suc and Glc uptake, with its effects being more pronounced in fresh tissue. Other protein-modifying reagents showed no significant difference in their level of inhibition between fresh and washed tissue. Transport studies, carried out using energized PM vesicles from fresh and washed tissue, indicated that there was no rise in Suc and Glc uptake rates in response to washing. Results with a range of inhibitors indicated that there was no marked change in transporter sensitivity in vesicles isolated from fresh and washed tissue. The results indicate that the well-described enhancement of solute transport in washed storage tissue may be due to an increased PM H+-ATPase activity rather than to changes in PM carrier activity or to changes in metabolism such as invertase activity. PMID:12223806

  2. Compaction creep by pore failure and pressure solution applied to a carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Keszthelyi, Daniel; Jamtveit, Bjørn; Dysthe, Dag Kristian

    2015-04-01

    The Ekofisk field in the Norwegian North sea is an example of a compacting carbonate reservoir with considerable seafloor subsidence due to petroleum production. Previously, a number of models were created to predict the compaction using different phenomenological approaches. We present a different approach, based on microscopic mechanisms with no fitting parameters. We create a time-dependent micromechanical model combining pore failure and pressure solution creep in presence of a oil-water mixture pore fluid. Then we use a statistical mechanical approach to scale it up to macroscopic scale and predict strain rate at core scale and at reservoir scale. The model is able to reproduce the magnitude of the observed subsidence making it the first microstructural model which can explain the Ekofisk compaction.

  3. Solution-mediated selective nanosoldering of carbon nanotube junctions for improved device performance.

    PubMed

    Do, Jae-Won; Chang, Noel N; Estrada, David; Lian, Feifei; Cha, Hyeongyun; Duan, Xiangyun J; Haasch, Richard T; Pop, Eric; Girolami, Gregory S; Lyding, Joseph W

    2015-05-26

    As-grown randomly aligned networks of carbon nanotubes (CNTs) invariably suffer from limited transport properties due to high resistance at the crossed junctions between CNTs. In this work, Joule heating of the highly resistive CNT junctions is carried out in the presence of a spin-coated layer of a suitable chemical precursor. The heating triggers thermal decomposition of the chemical precursor, tris(dibenzylideneacetone)dipalladium (Pd2(dba)3), and causes local deposition of Pd nanoparticles at the CNT junctions, thereby improving the on/off current ratio and mobility of CNT network devices by an average factor of ?6. This process can be conducted either in air or under vacuum depending on the characteristics of the precursor species. The solution-mediated nanosoldering process is simple, fast, scalable with manufacturing techniques, and extendable to the nanodeposition of a wide variety of materials. PMID:25844819

  4. Infrared (attenuated total reflection) study of propylene carbonate solutions containing lithium and sodium perchlorate.

    PubMed

    Brooksby, Paula A; Fawcett, W Ronald

    2006-05-15

    Attenuated total reflection infrared spectroscopy was used to examine the concentration dependent solvation of LiClO4 and NaClO4 electrolytes in propylene carbonate (PC). Factor analysis and curve fitting techniques were performed on the measured spectra and the results compared with ab initio computations to provide evidence for ion-solvent solution geometries. Factor analysis of the measured data allowed the identification of the spectrum of ion-associated PC that is uniquely different from the self-associated PC spectrum. The results indicate Li+ and ClO4- ions are contact ion-paired even at relatively low electrolyte concentrations whereas Na+ and ClO4- ions are not, up to approximately 2 mol dm-3. PMID:16384731

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

    NASA Astrophysics Data System (ADS)

    Lee, Choong-Seop; Yakobson, Boris I.

    2004-03-01

    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).

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

    NASA Astrophysics Data System (ADS)

    Ahmad, Rais; Kumar, Rajeev

    2010-12-01

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

  7. Activated carbons from potato peels: The role of activation agent and carbonization temperature of biomass on their use as sorbents for bisphenol A uptake from aqueous solutions

    NASA Astrophysics Data System (ADS)

    Arampatzidou, An; Deliyanni, Eleni A.

    2015-04-01

    Activated carbons prepared from potato peels, a solid waste by product, and activated with different activating chemicals, have been studied for the adsorption of an endocrine disruptor (Bisphenol-A) from aqueous solutions. The potato peels biomass was activated with phosphoric acid, KOH and ZnCl2. The different activating chemicals were tested in order the better activation agent to be found. The carbons were carbonized by pyrolysis, in one step procedure, at three different temperatures in order the role of the temperature of carbonization to be pointed out. The porous texture and the surface chemistry of the prepared activated carbons were characterized by Nitrogen adsorption (BET), Scanning Electron Microscope (SEM), thermal analysis (DTA) and Fourier Transform Infrared Spectroscopy (FTIR). Batch experiments were performed to investigate the effect of pH, the adsorbent dose, the initial bisphenol A concentration and temperature. Equilibrium adsorption data were analyzed by Langmuir and Freundlich isotherms. The thermodynamic parameters such as the change of enthalpy (?H0), entropy (?S0) and Gibb's free energy (?G0) of adsorption systems were also evaluated. The adsorption capacity calculated from the Langmuir isotherm was found to be 450 mg g-1 at an initial pH 3 at 25 °C for the phosphoric acid activated carbon, that make the activated carbon a promising adsorbent material.

  8. A Novel Glycinate-based Body Wash

    PubMed Central

    Regan, Jamie; Ananthapadmanabhan, K.P.

    2013-01-01

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

  9. Mechanisms of enhanced total organic carbon elimination from oxalic acid solutions by electro-peroxone process.

    PubMed

    Wang, Huijiao; Yuan, Shi; Zhan, Juhong; Wang, Yujue; Yu, Gang; Deng, Shubo; Huang, Jun; Wang, Bin

    2015-09-01

    Electro-peroxone (E-peroxone) is a novel electrocatalytic ozonation process that combines ozonation and electrolysis process to enhance pollutant degradation during water and wastewater treatment. This enhancement has been mainly attributed to several mechanisms that increase O3 transformation to OH in the E-peroxone system, e.g., electro-generation of H2O2 from O2 at a carbon-based cathode and its subsequent peroxone reaction with O3 to OH, electro-reduction of O3 to OH at the cathode, and O3 decomposition to OH at high local pH near the cathode. To get more insight how these mechanisms contribute respectively to the enhancement, this study investigated total organic carbon (TOC) elimination from oxalic acid (OA) solutions by the E-peroxone process. Results show that the E-peroxone process significantly increased TOC elimination rate by 10.2-12.5 times compared with the linear addition of the individual rates of corresponding ozonation and electrolysis process. Kinetic analyses reveal that the electrochemically-driven peroxone reaction is the most important mechanism for the enhanced TOC elimination rate, while the other mechanisms contribute minor to the enhancement by a factor of 1.6-2.5. The results indicate that proper selection of electrodes that can effectively produce H2O2 at the cathode is critical to maximize TOC elimination in the E-peroxone process. PMID:25989593

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

    SciTech Connect

    Varlashkin, P.G.

    1985-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  12. Effects of washing methods on gel properties of chicken surimi prepared from spent hen breast muscle.

    PubMed

    Kang, G H; Kim, S H; Kim, J H; Kang, H K; Kim, D W; Na, J C; Yu, D J; Suh, O S; Choi, Y H

    2009-07-01

    In this study, 2 myofibrillar protein extraction methods were compared for the preparation of chicken surimi using spent hen breast muscle. One method involved 1 washing with 0.1, 0.5, or 1% sodium chloride solution followed by 2 washings with distilled water, with homogenization and centrifugation of the breast muscle after each washing (new method; NM). The other method used only distilled water for the extraction, and washing was repeated 3 times followed by homogenization and centrifugation of the breast muscle after each washing (conventional method; CM). The redness values of the batter as well as the cooked gel were significantly lower (P < or = 0.05) by NM as compared with CM. In addition, the SDS-PAGE of NM sarcoplasmic protein fractions showed phosphorylase bands with increased staining intensity as compared with CM, indicating that brightness was related to the sarcoplasmic protein fractions. Overall, the data implied that sodium chloride solution was more appropriate for the myofibrillar protein extraction of spent hen breast muscle than the commonly used distilled water method. PMID:19531715

  13. Cu +2 cation+3,5-dimethyl pyrazole mixture as a corrosion inhibitor for carbon steel in sulfuric acid solution

    Microsoft Academic Search

    M Abdallah; M. M El-Naggar

    2001-01-01

    The inhibition effect of [Cu+2 cation+3,5-dimethyl pyrazole] mixture of different molar ratios on the corrosion of carbon steel in a 0.5M H2SO4 solution was studied using both weight loss and galvanostatic polarization techniques. The inhibiting solutions were analyzed using UV–visible spectrophotometric before and after polarization measurements. The results revealed a complex formation between the two components, which was much more

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

    Microsoft Academic Search

    L. C. Nielsen; D. J. Depaolo

    2010-01-01

    Precipitation of calcite and aragonite from aqueous solution causes kinetic stable Ca isotope fractionation under conditions where Ca2+ is greatly in excess of CO32-. Research on carbonate mineral growth from low Ca2+:CO32- activity ratio solutions is lacking. Mono Lake, California is a highly alkaline lake with a Ca2+:CO32- activity ratio of 9.6 x 10-4, over five orders of magnitude lower

  15. The electrochromic behavior of indium tin oxide in propylene carbonate solutions

    SciTech Connect

    Bressers, P.M.M.C. [Philips Research, Eindhoven (Netherlands)]|[Utrecht Univ. (Netherlands). Debye Inst.; Meulenkamp, E.A. [Philips Research, Eindhoven (Netherlands)

    1998-07-01

    The authors report on a study of transparent conducting tin-doped indium oxide (ITO) electrodes in propylene carbonate solutions containing lithium ions. The system was studied using electrochemical methods in combination with in situ techniques: ultraviolet-visible spectroscopy, X-ray diffraction, and quartz crystal microbalance. The results show that the cathodic process at E {approx_gt} 1.0 V vs. Li/Li{sup +} mainly involves the reduction of the electrolyte solution, leading to the formation of a thin, lithium-rich surface film. At potentials {approx_lt}1.0 V vs. Li/Li{sup +}, degradation of ITO and the formation of metallic indium take place. No evidence was obtained that lithium-ion intercalation into ITO, which has been suggested by several workers, occurs to a significant extent. The authors conclude that ITO probably cannot be used as a combined ion-storage layer and transparent conductor for all-solid-state and laminated electrochromic switching devices in view of long-term stability.

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

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  18. Removal of corrosive impurities by water washing of the oil in the benzol division

    SciTech Connect

    Kuz'mina, E.Ya.; Lebedeva, G.N.

    1983-01-01

    In the process of recovery of benzene hydrocarbons the wash oil absorbs gaseous compounds from the coke oven gas: hydrogen cyanide, hydrogen sulfide and ammonia. These substances, and also the products of their reaction, are sources of corrosion of equipment, and polymerization of unstable organic compounds with formation of high-carbon compounds. The wastewaters from the benzol divisions introduce a significant quantity of toxic impurities into the general coking plant wastewater. The corrosive impurities are removed from the recycled wash oil by washing it with water, on the basis of the higher solubility of the impurities in water than in the wash oil. However, quantitative data on the comparative solubility of the impurities are not available. In order to evaluate the possibility of extracting corrosive inpurities from the wash oil with water, the distribution coefficients of the gases and their reaction products absorbed by the oil (ammonium thiocyanate and ammonium cyanide) between the oils and the water were determined. 7 references, 2 tables.

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

    NASA Technical Reports Server (NTRS)

    1978-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Treatment with hypertonic saline versus normal saline nasal wash of pediatric chronic sinusitis

    Microsoft Academic Search

    David Shoseyov; Haim Bibi; Pintov Shai; Nurit Shoseyov; Gila Shazberg; Haggit Hurvitz

    1998-01-01

    Background: Chronic sinusitis (CS) is a common disease in children, especially those with allergies, that is caused by impaired drainage from the sinuses. Hypertonic NaCl solution has been shown to increase mucociliary clearance and ciliary beat frequency. Objective: We performed a randomized double blind study to compare the effect of nasal wash with hypertonic saline (HS) (3.5%) versus normal saline

  3. Resistivity reduction of boron-doped multiwalled carbon nanotubes synthesized from a methanol solution containing boric acid

    NASA Astrophysics Data System (ADS)

    Ishii, Satoshi; Watanabe, Tohru; Ueda, Shinya; Tsuda, Shunsuke; Yamaguchi, Takahide; Takano, Yoshihiko

    2008-05-01

    Boron-doped multiwalled carbon nanotubes (MWNTs) were synthesized using a methanol solution of boric acid as a source material. Accurate measurements of the electrical resistivity of an individual boron-doped MWNT was performed with a four-point contact, which was fabricated using an electron beam lithography technique. The doped boron provides conduction carriers, which reduces the resistivity of the MWNT.

  4. Application of Fly Ash and Activated Carbon in the Removal of Cu and Ni Ions from Aqueous Solutions

    Microsoft Academic Search

    E. Pehlivan; S. Cetin

    2008-01-01

    The main objective of this study was to remove Cu and Ni ions from aqueous solution by using fly ash, an industrial solid waste of the sugar industry and commercial activated carbon at equilibrium, which follows Langmuir and Freundlich adsorption isotherms. In order to identify influential parameters and to evaluate their interactions, effects of time, pH, initial metal concentration, and

  5. Effects of Predrying and Vacuum Impregnation with Nano-Calcium Carbonate Solution on Strawberries, Carrots, Corn, and Blueberries

    Microsoft Academic Search

    Zhiqing Gong; Leyi Gao; Jianshen An; Min Zhang; A. S. Mujumdar; Jincai Sun

    2009-01-01

    Predrying followed by vacuum impregnation using a solution of nanosized calcium carbonate was carried out for several products such as strawberries, blueberries, carrots, and corn. This process improved impregnation mass of the functional substance in the products tested. Though products like butter candy taste sweet, due to their high content of sugar and fat they face high consumer resistance. The

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

    Microsoft Academic Search

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

    2012-01-01

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

  7. High catalytic performance of Pt nanoparticles on plasma treated carbon nanotubes for electrooxidation of ethanol in a basic solution

    NASA Astrophysics Data System (ADS)

    Jiang, Zhongqing; Jiang, Zhong-jie; Meng, Yuedong

    2011-01-01

    Nanosized Pt particles deposited on plasma treated multi-walled carbon nanotubes have been used in electrocatalytic oxidation of ethanol in a basic solution. These Pt nanoparticles have very narrow size distribution and exhibit significant higher catalytic activities, higher Pt utilization efficiency (93.77%) and improved durability in comparison to the commercial available Johnson Matthey Pt/C catalyst.

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

    SciTech Connect

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

    2014-03-24

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

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

    USGS Publications Warehouse

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

    1971-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-01

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

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

    NASA Technical Reports Server (NTRS)

    Herrmann, Cal C.

    1993-01-01

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

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

    PubMed

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

    2015-03-14

    The transition from nanoparticles suspended in aqueous solutions into solid fluorescent structures is developed for application in solid functional devices. The presented approach enables the organization of carbon dots into rod-like shapes that can still be re-dispersed into aqueous solution. Schiff bases forming at the surface of carbon dots not only protect their surface states, but also provide sites for tethering to other carbon dots. As a consequence, the large assemblies of CDs can come together to form regular, well ordered structures whilst still maintaining their photoluminescence properties. This opens up enormous possibilities for device manufacture, as these self-assemblies could be grown or grafted onto templates forming regular structures, and find innumerable applications ranging from optoelectronic devices, light harvesting to artificial photosynthesis. PMID:25684699

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

    SciTech Connect

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

    2010-01-15

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

  14. 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

  15. 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

  16. Use of antimicrobial agents in a novel cattle washing system

    E-print Network

    Covington, Brian Reed

    2001-01-01

    Antimicrobial agents, 0.5% L-lactic acid and 50 ppm chlorine, along with water wash treatments (single or double) were evaluated in a cattle washing system for their effectiveness in reducing Aerobic Plate Counts (APC), coliforms, generic...

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

    PubMed

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

    2014-10-01

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

  18. Radiotracers in fabric-washing studies

    Microsoft Academic Search

    B. E. Gordon

    1968-01-01

    This report is directed toward the application of radiotracers to larger-scale, practical launder-ing experiments with the\\u000a use of washing machines and Tergotometers with fully built detergents. Such applications have not been widely reported because\\u000a of the difficulty in setting up the experi-ments, in handling the large numbers of samples which are generated, and performing\\u000a the many computations. A brief description

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

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

    SciTech Connect

    Siegel, D.I.

    1992-04-09

    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.

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

    USGS Publications Warehouse

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

    2011-01-01

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

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

    PubMed

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

    2015-01-01

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

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

    E-print Network

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

    2008-01-01

    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...

  4. Surfactant selection for enhancing ex situ soil washing

    Microsoft Academic Search

    S. Deshpande; B. J. Shiau; D. Wade; D. A. Sabatini; J. H. Harwell

    1999-01-01

    Ex situ soil washing is commonly used for treating contaminated soils by separating the most contaminated fraction of the soil for disposal. Surfactant-enhanced soil washing is being considered with increasing frequency to actually achieve soil-contaminant separation. In this research eight anionic and nonionic surfactants were evaluated for the enhanced soil washing of three different soils contaminated with petroleum hydrocarbons. Enhanced

  5. Basic solutions to carbon/carbon oxidation: Science and technology. Final report, 15 April 1993--14 April 1998

    SciTech Connect

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

    1998-04-14

    The goal of this study was to gain a fundamental understanding of the role of boron in carbon oxidation. Boron-doped carbons were synthesized via CVD, ion implantation and high temperature doping are subsequently characterized. It was found that high temperature doped HOPG carbons were ideal for oxidation studies because their surface could be reproduced, their surface structures were determined and they were able to be characterized by XPS, AFM and SEM. The direct analysis of the chemical structures and atomic arrangements in boron- doped carbon or carbon surfaces by these techniques was critical in determining the effect of boron on carbon oxidation. XPS was utilized in this work to determine the local bonding environment of boron in carbon before an after oxidation. It was necessary to obtain an accurate calibration of the B1s binding energy scale which was accomplished by obtaining photoemission spectra of boron-doped carbons with known structures (local boron bonding environments), such as boron oxide, boron carbide, triphenylboroxine, tourmaline, boric acid, danburite and high temperature boron-doped graphite. All of the aforementioned standards contain boron in a unique bonding environment and thus their spectra formulated a complete conversion of B1s binding energies to boron chemical environments which has not been reported in the past. It was clearly established that a chemical shift for substitutional boron in graphite exists at 186.5 eV with a FWHM of 1.2. The chemical structures of the boron in the standards were related to the binding energy using a Pauling charge distribution model and a modification of the Sanderson electronegativity method. This approach was used to determine whether the B1s binding energy would change depending upon the specific location of boron in the graphite or graphite surface.

  6. Purification of aqueous plutonium chloride solutions via precipitation and washing.

    SciTech Connect

    Stroud, M. A. (Mary Ann); Salazar, R. R. (Richard R.); Abney, Kent David; Bluhm, E. A. (Elizabeth A.); Danis, J. A. (Janet A.)

    2003-01-01

    Pyrochemical operations at Los Alamos Plutonium Facility (TA-55) use high temperature melt s of calcium chloride for the reduction of plutonium oxide to plutonium metal and hi gh temperature combined melts of sodium chloride and potassium chloride mixtures for the electrorefining purification of plutonium metal . The remaining plutonium and americium are recovered from thes e salts by dissolution in concentrated hydrochloric acid followed by either solvent extraction or io n exchange for isolation and ultimately converted to oxide after precipitation with oxalic acid . Figur e 1 illustrates the current aqueous chloride flow sheet used for plutonium processing at TA-55 .

  7. Interaction of cataclasis and pressure solution in a low-temperature carbonate shear zone

    NASA Astrophysics Data System (ADS)

    Hadizadeh, Jafar

    1994-03-01

    The mineralogical and elemental variations across the main shear zone of the Saltville thrust at Sharp Gap in Knoxville, Tennessee, U.S.A., were studied in a suite of deformed and undefromed carbonate rock samples using X-ray diffraction and electron microprobe methods. An examination of the samples for deformation effects at mesoscopic scale and under the optical microscope reveals familiar cataclastic deformation features including foliated cataclasites and microbreccias occurring in a well-defined, 1 2 m wide zone of intense deformation, plus evidence of hydrofracturing and extensive syndeformational pressure solution. There exists a clear correlation between the observed cataclastic deformation and mineral and elemental distribution which we interpret to result from a deformation-induced dolomite to calcite transformation in the shear zone. The transformation has resulted in removal of Mg from the shear zone, selective deposition of calcite as an intergranular cement in cataclasite/microbreccia units and a relative increase in the concentration of detrital quartz and feldspars. The compositional difference between the shear zone and wall rocks is explained in connection with cataclastic deformation features in terms of a model in which a dual pressure-solution/cataclastic flow mechanism leads to a gradual cementation-hardening of segments of the shear zone. Instabilities could occur via permeability reduction and increased pore pressure within these segments. Hydrofracturing of the hardened segments along with high strain rate reordering of the shear zone materials reset the ruptured zone back to the dual deformation mechanism regime. As a long-term effect, the compositional transformation of the shear zone is expected to prolong periods of creep and cause smaller coseismic stress drops since under the imposed conditions calcite is more ductile and soluble than dolomite.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

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

    SciTech Connect

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

    1995-02-01

    An experimental system was developed to reproduce stress corrosion cracking (SCC) of API X-60 line pipe steels in highly alkaline (pH = 10) carbonate-bicarbonate (1 N sodium carbonate [Na[sub 2]CO[sub 3

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

    PubMed

    Zohdi, Nima; Mahdavi, Fariba; Abdullah, Luqman Chuah; Choong, Thomas Sy

    2014-01-01

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

  11. Arsenic adsorption by polyvinyl pyrrolidone K25 coated cassava peel carbon from aqueous solution.

    PubMed

    Selvakumar, R; Kavitha, S; Sathishkumar, M; Swaminathan, K

    2008-05-01

    Sorption of arsenic from aqueous solution was carried out using polyvinyl pyrrolidone K25 coated cassava peel carbon (PVPCC). Batch experiments were conducted to determine the effect of contact time, initial concentration, pH and desorption. Batch sorption data's were fitted to Lagergren kinetic studies. Column studies were also conducted using PVPCC as adsorbent. The optimized flow rate of 2.5 mL min(-1) and bed height 10 cm were used to determine the effect of metal ion concentration on removal of As(V). BDST model was applied to calculate the adsorption capacity (N(0)) of column. The N(0) value of 2.59 x 10(-5), 4.21 x 10(-5), 4.05 x 10(-5), 4.26 x 10(-5) and 3.2 x 10(-5) mg g(-1) were obtained for 0.5, 1.0, 1.5, 2.0 and 2.5 mg L(-1) of As(V), respectively. The batch sorption proved to be more efficient than the column sorption. The sorption of As(V) and the nature of the adsorbent was examined by Fourier transmission infrared spectroscopy (FTIR) and X-ray diffraction (XRD) studies, respectively. PMID:17881120

  12. Degradation of carbon tetrachloride in aqueous solution in the thermally activated persulfate system.

    PubMed

    Xu, Minhui; Gu, Xiaogang; Lu, Shuguang; Qiu, Zhaofu; Sui, Qian; Miao, Zhouwei; Zang, Xueke; Wu, Xiaoliang

    2015-04-01

    Thermal activation of persulfate (PS) has been identified to be effective in the destruction of organic pollutants. The feasibility of carbon tetrachloride (CT) degradation in the thermally activated PS system was evaluated. The experimental results showed that CT could be readily degraded at 50 °C with a PS concentration of 0.5M, and CT degradation and PS consumption followed the pseudo-first order kinetic model. Superoxide radical anion (O2(*-)) was the predominant radical species responsible for CT degradation and the split of CCl was proposed as the possible reaction pathways for CT degradation. The process of CT degradation was accelerated by higher PS dose and lower initial CT concentration. No obvious effect of the initial pH on the degradation of CT was observed in the thermally activated PS system. Cl(*-), HCO3(*-), and humic acid (HA) had negative effects on CT degradation. In addition, the degradation of CT in the thermally activated PS system could be significantly promoted by the solvents addition to the solution. In conclusion, the thermally activated PS process is a promising option in in-situ chemical oxidation/reduction remediation for degrading highly oxidized organic contaminants such as CT that is widely detected in contaminated sites. PMID:25544995

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

    PubMed

    Poerschmann, J; Weiner, B; Baskyr, I

    2013-09-01

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

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

    PubMed Central

    2014-01-01

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

  15. Influence of mesopore volume and adsorbate size on adsorption capacities of activated carbons in aqueous solutions

    Microsoft Academic Search

    Chien-To Hsieh; Hsisheng Teng

    2000-01-01

    Liquid-phase adsorption of phenol, iodine and tannic acid onto commercial grade granular activated carbons and activated carbon fabric was conducted to explore the influence of the mesopore volume and the size of adsorbates on the adsorption capacity. These carbons have different mesopore volumes, while possessing similar surface areas and micropore volumes, which are believed to determine the adsorption capacity in

  16. Sorption of reactive dyes from aqueous solutions by ordered hexagonal and disordered mesoporous carbons

    Microsoft Academic Search

    Despoina D. Asouhidou; Kostas S. Triantafyllidis; Nikolaos K. Lazaridis; Kostas A. Matis; Seong-Su Kim; Thomas J. Pinnavaia

    2009-01-01

    In the present study two synthetic mesoporous carbons, a highly ordered CMK-3 sample with hexagonal structure and a disordered mesoporous carbon (denoted DMC) were investigated for the sorption of Remazol Red 3BS (C.I. 239) dye in comparison to three commercial activated carbons and a HMS mesoporous silica with a wormhole pore structure. The structural, porosity and surface characteristics of the

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

    SciTech Connect

    Jones, Christopher; Glachant, Jean-Michel

    2010-04-15

    The present pace of carbon emission is not sustainable. Human societies need to react and to change. A rational responsive policy to deliver the required carbon emission reduction can be delineated if the key objective parameters are identified and addressed. This article attempts to lay the groundwork for a viable carbon energy policy for Europe. (author)

  18. Reduction of foliar dislodgable pesticide residues from orange trees through spraywashing with water or lime solution

    Microsoft Academic Search

    G. E. Carman; F. A. Gunther; W. E. Westlake; Y. Iwata

    1976-01-01

    Conclusions The volume of water applied is the single important factor in reducing foliar dislodgable residues by tree-washing with an oscillating boom spray rig, and none of the other washing parameters tested could be altered so as to increase washing efficiency and allow a reduction in the amount of water used. The additiion of lime to the washing solution did

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

    PubMed Central

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

    2014-01-01

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

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

    E-print Network

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

    2014-10-09

    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.

  1. Remediation of cadmium- and lead-contaminated agricultural soil by composite washing with chlorides and citric acid.

    PubMed

    Li, Yu-jiao; Hu, Peng-jie; Zhao, Jie; Dong, Chang-xun

    2015-04-01

    Composite washing of cadmium (Cd)- and lead (Pb)-contaminated agricultural soil from Hunan province in China using mixtures of chlorides (FeCl3, CaCl2) and citric acid (CA) was investigated. The concentrations of composite washing agents for metal removal were optimized. Sequential extraction was conducted to study the changes in metal fractions after soil washing. The removal of two metals at optimum concentration was reached. Using FeCl3 mixed with CA, 44% of Cd and 23% of Pb were removed, and 49 and 32% by CaCl2 mixed with CA, respectively. The mechanism of composite washing was postulated. A mixture of chlorides and CA enhanced metal extraction from soil through the formation of metal-chloride and metal-citrate complexes. CA in extract solutions promoted the formation of metal-chloride complexes and reduced the solution pH. Composite washing reduced Cd and Pb in Fe-Mn oxide forms significantly. Chlorides and CA exerted a synergistic effect on metal extraction during composite washing. PMID:25342453

  2. Structural effects on the interactions of benzene and naphthalene sulfonates with activated carbon cloth during adsorption from aqueous solutions

    Microsoft Academic Search

    Erol Ayranci; Osman Duman

    2010-01-01

    Interactions of benzene and naphthalene sulfonates with activated carbon cloth (ACC) during adsorption from aqueous solutions were investigated. Systematically chosen sulfonates were sodium salt of benzene sulfonic acid (NaBS), disodium salt of 1,3-benzene disulfonic acid (Na2BDS), sodium salt of 1-naphthalene sulfonic acid (NaNS), disodium salt of 1,5-naphthalene disulfonic acid (Na2NDS) and trisodium salt of 1,3,(6 or 7)-naphthalene trisulfonic acid (Na3NTS).

  3. Kinetic characteristics of the synthesis of multiwall carbon nanotubes by aerosol pyrolysis of a ferrocene solution in benzene

    NASA Astrophysics Data System (ADS)

    Cherkasov, N. B.; Savilov, S. B.; Pryakhin, A. N.; Ivanov, A. S.; Lunin, V. V.

    2012-03-01

    Approximating the experimental data on the mass distribution of multiwall carbon nanotubes (MCNT) along a reactor, a three-step kinetic model of their synthesis in the aerosol pyrolysis of a ferrocene solution in benzene is proposed. The values of effective rate constants upon the introduction of a catalyst in situ for the reactions that are the basis for synthesizing MCNT via the pyrolysis of hydrocarbons are obtained for the first time.

  4. Current distribution during galvanic corrosion of carbon steel welded with type-309 stainless steel in NaCl solution

    Microsoft Academic Search

    Koji Fushimi; Atsushi Naganuma; Kazuhisa Azumi; Yuuzo Kawahara

    2008-01-01

    Galvanic corrosion of carbon steel welded with type-309 stainless steel in NaCl solution was tentatively evaluated with a newly developed multi-channel electrode technique in which the welded specimen was divided into nine working electrodes (WEs), reconstructed in resin, and connected individually to an imaginary ground level of an electric circuit via relay switches. This allows the WEs to join a

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

    Microsoft Academic Search

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

    2006-01-01

    Forward (direct) osmosis (FO) using semi-permeable polymeric membranes may be a viable alternative to reverse osmosis as a lower cost and more environmentally friendly desalination technology. The driving force in the described FO process is provided by a draw solution comprising highly soluble gases—ammonia and carbon dioxide. Using a commercially available FO membrane, experiments conducted in a crossflow, flat-sheet membrane

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

    SciTech Connect

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

    1982-07-01

    The nature of protective surface layers formed on lithium in propylene carbonate solutions of LiClO/sub 4/ and LiAsF/sub 6/ at open circuit has been investigated by electrochemical pulse measurements. The resuts are consistent with the fast formation of a compact thin layer resulting from the reaction with residual water. This layer acts as a solid ionic conductor. Slow corrosion or decomposition processes produce a thicker porous overlayer. 22 refs.

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

    SciTech Connect

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

    1981-11-01

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

  8. Glassy carbon electrode modified by conductive polyaniline coating for determination of trace lead and cadmium ions in acetate buffer solution

    Microsoft Academic Search

    Zhaomeng Wang; Erjia Liu; Xing Zhao

    2011-01-01

    Polyaniline (PANI) coatings were electrodeposited on the surfaces of glassy carbon electrodes (GCEs) to form new electrodes, i.e. PANI\\/GCEs. It was found that with increased deposition time, the PANI coatings became more compact while the charge transfer resistance of the coatings became higher. The PANI\\/GCEs were used to detect Cd2+ and Pb2+ ions contained in 0.1M acetate buffer solutions using

  9. Effects of alternating current on corrosion of a coated pipeline steel in a chloride-containing carbonate\\/bicarbonate solution

    Microsoft Academic Search

    A. Q. Fu; Y. F. Cheng

    2010-01-01

    In this work, the alternating current (AC)-induced corrosion of a coated pipeline steel was studied in a chloride-containing, concentrated carbonate\\/bicarbonate solution, which simulated the trapped high pH electrolyte under coating, by potentiodynamic polarization measurements, immersion tests and surface characterization technique. It was found that an application of AC resulted in a negative shift of corrosion potential of the steel, caused

  10. Impedance of Li?Sn, Li?Cd and Li?Sn?Cd alloys in propylene carbonate solution

    Microsoft Academic Search

    Alexei V. Churikov; Eugeny S. Nimon; Arlen L. Lvov

    1997-01-01

    Electric properties of passivating films forming on the surface of Li?Sn, Li?Cd and Li?Sn?Cd alloy electrodes in propylene carbonate-based solutions have been investigated using the electrode impedance spectroscopy technique. Within the range of high and medium frequencies, the impedance spectrum has been shown to be described by the equivalent circuit represented by geometric capacitance and ionic resistance of the film,

  11. Axial Dispersion during Hanford Saltcake Washing

    SciTech Connect

    Josephson, Gary B.; Geeting, John GH; Lessor, Delbert L.; Barton, William B.

    2006-08-01

    Clean up of Hanford salt cake wastes begins with dissolution retrieval of the sodium rich salts that make up the dominant majority of mass in the tanks. Water moving through the porous salt cake dissolves the soluble components and also displaces the soluble radionuclides (e.g. 137Cs and 99TcO4- ). The separation that occurs from this displacement, known as Selective dissolution, is an important component in Hanford’s pretreatment of low activity wastes for subsequent Supplemental treatment. This paper describes lab scale testing conducted to evaluate Selective dissolution of cesium from non-radioactive Hanford tank 241-S-112 salt cake simulant containing the primary chemicals found the the actual tank. An modified axial dispersion model with increasing axial dispersion was developed to predict cesium removal. The model recognizes that water dissolves the salt cake during washing, which causes an increase in the axial dispersion during the wash. This model was subsequently compared with on-line cesium measurements from the retrieval of tank 241-S-112. The model had remarkably good agreement with both the lab scale and full scale data.

  12. Enhanced salmonella reduction on tomatoes washed in chlorinated water with wash aid T-128

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorine is widely used by the fresh and fresh-cut produce industries to reduce microbial populations and to prevent potential pathogen cross contamination during produce washing. However, the organic materials released from produce quickly react with chlorine and degrade its efficacy for pathogen i...

  13. Alternative solution model for the ternary carbonate system CaCO3 - MgCO3 - FeCO3

    NASA Astrophysics Data System (ADS)

    McSwiggen, Peter L.

    1993-05-01

    Earlier attempts at solution models for the ternary carbonate system have been unable to adequately accommodate the cation ordering which occurs in some of the carbonate phases. The carbonate solution model of this study combines a Margules type of interaction model with a Bragg-Williams type of ordering model. The ordering model determines the equilibrium state of order for a crystal, from which the cation distribution within the lattice can be obtained. The interaction model addresses the effect that mixing different cation species within a given cation layer has on the total free energy of the system. An ordering model was derived, based on the Bragg-Williams approach; it is applicable to ternary systems involving three cations substituting on two sites, and contains three ordering energy parameters ( W CaMg, WCaFe, and W CaMgFe). The solution model of this study involves six Margules-type interaction parameters ( W 12, W 21, W 13, W 31, W 23, and W 32). Values for the two sets of energy parameters were calculated from experimental data and from compositional relationships in natural assemblages.

  14. Adsorption of the complex ion Au(CN)2- onto sulfur-impregnated activated carbon in aqueous solutions.

    PubMed

    Ramírez-Muñiz, Kardia; Song, Shaoxian; Berber-Mendoza, Selene; Tong, Shitang

    2010-09-15

    The adsorption of the gold-cyanide complex ion (Au(CN)(2)(-)) on sulfur-impregnated activated carbon in aqueous solution has been studied in order to find a better adsorbent for the gold cyanidation process for extracting gold from ores. This study was performed using sulfur-impregnated activated carbon (SIAC 8.0) made from high-sulfur petroleum coke and an artificial aqueous solution of Au(CN)(2)(-). The experimental results have shown that Au(CN)(2)(-) strongly adsorbed onto the SIAC 8.0, leading the gold adsorption capacity of the SIAC 8.0 to be 2.25x that on conventional activated carbon. It has been also found that the adsorption fit the Langmuir isotherm well, and the adsorption density of Au(CN)(2)(-) on the SIAC 8.0 in aqueous solution increased with increasing temperature, suggesting chemical adsorption. The chemical adsorption might be attributed to the formation of S-Au-CN on SIAC 8.0 surfaces through the covalent bond between the gold atom of the ion and the sulfur in the molecular structure of the SIAC 8.0. In addition, the desorption test has demonstrated that the majority of the adsorption was irreversible, which depended on the density of the adsorption sites on the SIAC. PMID:20580375

  15. Adsorption of 2-nitrophenol by multi-wall carbon nanotubes from aqueous solutions

    Microsoft Academic Search

    R. Arasteh; M. Masoumi; A. M. Rashidi; L. Moradi; V. Samimi; S. T. Mostafavi

    2010-01-01

    Adsorption of 2-nitrophenol in aqueous phase on multi-wall carbon nanotubes (MWNTs) and functionalized multi-wall carbon nanotubes having covalent attachments of carboxylic groups (MWNTs-COOH) has been considered. Adsorption behavior of 2-nitrophenol onto carbon nanotubes was studied by varying the parameters such as agitation time, 2-nitrophenol concentration and pH. The presence of surface functional groups affected the adsorption capacity of MWNTs for

  16. Failure of hand disinfection with frequent hand washing: a need for prolonged field studies

    PubMed Central

    Ojajärvi, Juhani; Mäkelä, Paavo; Rantasalo, Ilari

    1977-01-01

    In a prolonged field trial a 4% chlorhexidine digluconate detergent scrub (HibiscrubR), that had earlier proved to be an effective hand disinfectant, was studied in hospital wards. Finger tips were found to harbour more bacteria than the hand dorsum and the samples collected from them yielded more information on the bacteriological and dermatological effects of hand disinfectants in practice. In wards with a relatively low hand-washing frequency (less than 20 times in 8 hours) the bacteriological results resembled those obtained by in-use tests with volunteers. In the neonatal unit where the hand washing frequency was remarkably high, even occasionally over 100 times/8 h shift, an increase in the bacterial colony counts of the majority of the staff was recorded both before and after hand washing already after using the preparation for 1 week. Age, occupation and hand-washing frequency all correlated with the bacteriological results. Twenty-seven out of 37 persons complained of side effects such as wounds of finger tips and redness or heavy drying of the skin. Wounds, particularly on finger tips, resulted in the failure of disinfection. An increase in bacterial counts was sometimes noted without any dermatological or subjective changes. Drying of the skin was complained of less often when no increase in skin bacteria occurred. After the changeover of washing practice to a detergent followed by a rinse with spirit solution containing chlorhexidine and glycerol a decrease was recorded in the bacterial counts. It is concluded that more attention should be paid to long-term testing of hand washing and disinfection methods to ensure optimum final results in practice. It is obvious that the knowledge obtained from short time in-use testing cannot be applied to all conditions of use. PMID:267663

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

    E-print Network

    Lin, Shangchao

    2012-01-01

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

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

    PubMed

    Nagashanmugam, K B; Srinivasan, K

    2010-10-01

    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

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

    PubMed

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

    2010-02-15

    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

  20. Accuracy of three polyvinyl siloxane putty-wash impression techniques

    Microsoft Academic Search

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

    2000-01-01

    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

  1. Direct synthesis of H 2O 2 acid solutions on carbon cathode prepared from activated carbon and vapor-growing-carbon-fiber by a H 2\\/O 2 fuel cell

    Microsoft Academic Search

    Ichiro Yamanaka; Toshikazu Hashimoto; Ryo Ichihashi; Kiyoshi Otsuka

    2008-01-01

    Direct synthesis of H2O2 acid solutions was studied using a gas-diffusion cathode prepared from activated carbon (AC), vapor-growing-carbon-fiber (VGCF) and poly-tetra-fluoro-ethylene (PTFE) powders, with a new H2\\/O2 fuel cell reactor. O2 reduction to H2O2 was remarkably enhanced at the three-phase boundary (O2(g)–electrode(s)–acid(l)) at the [AC+VGCF] cathode. Fast diffusion processes of O2 to the active surface and of H2O2 to the

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

    PubMed Central

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

    2013-01-01

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

  3. Effect of acetate and carbonate buffers on the photolysis of riboflavin in aqueous solution: a kinetic study.

    PubMed

    Ahmad, Iqbal; Anwar, Zubair; Iqbal, Kefi; Ali, Syed Abid; Mirza, Tania; Khurshid, Adeela; Khurshid, Aqeela; Arsalan, Adeel

    2014-06-01

    The photolysis of riboflavin (RF) in the presence of acetate buffer (pH 3.8-5.6) and carbonate buffer (pH 9.2-10.8) has been studied using a multicomponent spectrophotometric method for the simultaneous assay of RF and its photoproducts. Acetate and carbonate buffers have been found to catalyze the photolysis reaction of RF. The apparent first-order rate constants for the acetate-catalyzed reaction range from 0.20 to 2.86 × 10(-4) s(-1) and for the carbonate-catalyzed reaction from 3.33 to 15.89 × 10(-4) s(-1). The second-order rate constants for the interaction of RF with the acetate and the carbonate ions range from 2.04 to 4.33 × 10(-4) M(-1) s(-1) and from 3.71 to 11.80 × 10(-4) M(-1) s(-1), respectively. The k-pH profile for the acetate-catalyzed reaction is bell shaped and for the carbonate-catalyzed reaction a steep curve. Both HCO3(-) and CO3(2-) ions are involved in the catalysis of the photolysis reaction in alkaline solution. The rate constants for the HCO3(-) and CO3(2-) ions catalyzed reactions are 0.72 and 1.38 × 10(-3) M(-1) s(-1), respectively, indicating a major role of CO3(2-) ions in the catalysis reaction. The loss of RF fluorescence in acetate buffer suggests an interaction between RF and acetate ions to promote the photolysis reaction. The optimum stability of RF solutions is observed in the pH range 5-6, which is suitable for pharmaceutical preparations. PMID:24504494

  4. EFRT M-12 Issue Resolution: Solids Washing

    SciTech Connect

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

    2010-01-01

    Pacific Northwest National Laboratory (PNNL) was tasked by Bechtel National Inc. (BNI) on the River Protection Project-Hanford Tank Waste Treatment and Immobilization Plant (RPP-WTP) project to perform research and development activities to resolve technical issues identified for the Pretreatment Facility (PTF). The Pretreatment Engineering Platform (PEP) was designed, constructed, and operated as part of a plan to respond to issue M12, “Undemonstrated Leaching Processes” of the External Flowsheet Review Team (EFRT) issue response plan.( ) The PEP is a 1/4.5-scale test platform designed to simulate the WTP pretreatment caustic leaching, oxidative leaching, ultrafiltration solids concentration, and slurry washing processes. The PEP replicates the WTP leaching processes using prototypic equipment and control strategies. The PEP also includes non-prototypic ancillary equipment to support the core processing.

  5. Hand wash and manual skin wipes.

    PubMed

    Brouwer, D H; Boeniger, M F; van Hemmen, J

    2000-10-01

    Hand wash and skin wipes are major techniques that have been used for dermal exposure sampling. Both techniques remove chemicals either deposited on or transferred to the skin contaminant layer by a combination of chemical and mechanical actions. The paper overviews identified methods and techniques, with emphasis on sampling parameters and sampling efficiency. It is concluded that identified sampling protocols, including sampling techniques, deviate at possible key issues, which hampers comparisons of study results. It is recommended to conduct sampling efficiency studies prior to field sampling, under conditions that are quite similar to conditions of exposure regarding exposure process, levels of skin loading, and time of residence of the compound on the skin. Harmonization of sampling protocols will be a first step in creating a database for better understanding the influence of sampling parameters on the performance of removal techniques to assess dermal exposure. PMID:11042251

  6. Landscape of WASH-relevant Training for Humanitarian Emergencies

    PubMed Central

    Dorea, Caetano

    2015-01-01

    Background: Both employed humanitarian personnel as well as those seeking to start a career as an aid worker are often provided with or seek training on the theme of humanitarian water, sanitation, and hygiene (WASH). The objective of this study was to conduct a landscaping exercise of the available WASH-relevant training for humanitarian emergencies. Methods: An open internet search was performed with specific terms related to humanitarian WASH. Retained search results included those training opportunities (including past ones) that were themed around or with a mentioned relevance to humanitarian WASH. Results and Discussion: A total of 42 training courses relevant to humanitarian emergency WASH were retained. In addition to the more generic/introductory trainings, some provided thematic variations such as coordination of WASH responses, project management, risk reduction, information, education and communication (IEC), and complex emergencies. Timely topics such as urban WASH, Ebola, and WASH innovations were also observed indicating the responsiveness of the training providers to the changing needs of humanitarian WASH response programmes. This survey also revealed a large variety in terms of target audience, duration, fees, location, and language of courses. There was no centralised listing of courses available on the Internet. Limitations of this exercise were also discussed.

  7. Effects of acid washing on stable isotope ratios of C and N in penaeid shrimp and seagrass: Implications for food-web studies using multiple stable isotopes

    Microsoft Academic Search

    S. E. Bunn; M. A. Kempster; N. R. Loneragan

    1995-01-01

    We investigated the effects of acid washing on the carbon and nitrogen composition and stable isotope ratios of C and N in shrimp (Metapenaeus spp.) and seagrass (Enhalus acoroides). Acid washing did not affect the mean δ¹³C ratios for juvenile Metapenaeus moyebi and resulted in only an ecologically insignificant change (0.3%) in mean δ¹³C ratios for larger metapenaeus bennettae. In

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

    SciTech Connect

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

    1998-04-01

    The effect of temperature on the reversible and irreversible capacities of disordered carbons derived from polymethacryonitrile (PMAN) and divinylbenzene (DVB) copolymers was studied in 1 M LiPF{sub 6}/ethylene carbonate (EC)-dimethyl carbonate (DMC) (1:1 v/v) solution by galvanostatic cycling. The kinetics of passive film formation were examined by complex-impedance spectroscopy. Temperatures of 5, 21, and 35 C were used in the study.

  9. Adsorption of the Cu 2+ ions from aqueous solutions on the active carbon oxidized with hydrogen peroxide and impregnated with nitrogen-containing compounds

    Microsoft Academic Search

    T. Lupa?cu; G. Petukhova; M. Ciobanu; V. Botsan

    2008-01-01

    Adsorption of the copper ions from aqueous solutions, benzene, and water on the active carbon obtained by chemical activation\\u000a from walnut shells was studied. The active carbon was additionally oxidized with hydrogen peroxide and then impregnated with\\u000a nitrogen-containing compounds. As a result of impregnation with melamine, a secondary porosity is formed within the oxidized\\u000a active carbon, leading to an increase

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

    Microsoft Academic Search

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

    2003-01-01

    Activated carbons were prepared from the agricultural solid wastes, silk cotton hull, coconut tree sawdust, sago waste, maize cob and banana pith and used to eliminate heavy metals and dyes from aqueous solution. Adsorption of all dyes and metal ions required a very short time and gave quantitative removal. Experimental results show all carbons were effective for the removal of

  11. Sludge pretreatment chemistry evaluation: Enhanced sludge washing separation factors

    SciTech Connect

    Colton, N.G.

    1995-03-01

    This report presents the work conducted in Fiscal Year 1994 by the Sludge Pretreatment Chemistry Evaluation Subtask for the Tank Waste Remediation System (TWRS) Tank Waste Treatment Science Task. The main purpose of this task, is to provide the technical basis and scientific understanding to support TWRS baseline decisions and actions, such as the development of an enhanced sludge washing process to reduce the volume of waste that will require high-level waste (HLW) vitrification. One objective within the Sludge Pretreatment Chemistry Evaluation Subtask was to establish wash factors for various SST (single-shell tank) sludges. First, analytical data were compiled from existing tank waste characterization reports. These data were summarized on tank-specific worksheets that provided a uniform format for reviewing and comparing data, as well as the means to verify whether the data set for each tank was complete. Worksheets were completed for 27 SST wastes. The analytical water wash data provided tank-specific information about the fraction of each component that dissolves with water, i.e., an estimate of tank-specific wash factors for evaluating tank-by-tank processing. These wash data were then used collectively to evaluate some of the wash factors that are assumed for the overall SST waste inventory; specifically, wash factors for elements that would be found primarily in sludges. The final step in this study was to incorporate the characterization and wash factor data into a spreadsheet that provides insight into the effect of enhanced sludge washing on individual tank sludges as well as for groups of sludges that may be representative of different waste types. Spreadsheet results include the estimated mass and percentage of each element that would be removed with washing and leaching. Furthermore, estimated compositions are given of the final wash and leach streams and residual solids, in terms of both concentration and dry weight percent.

  12. The Adsorption of Gold, Palladium, and Platinum from Acidic Chloride Solutions on Mesoporous Carbons

    SciTech Connect

    Peter R. Zalupski; Rocklan McDowell

    2014-10-01

    Studies on the adsorption characteristics of gold, palladium, and platinum on mesoporous carbon (CMK-3) and sulfur-impregnated mesoporous carbon (CMK-3/S) evaluated the benefits/drawbacks of the presence of a layer of elemental sulfur inside mesoporous carbon structures. Adsorption isotherms collected for Au(III), Pd(II), and Pt(IV) on those materials suggest that sulfur does enhance the adsorption of those metal ions in mildly acidic environment (pH 3). The isotherms collected in 1 M HCl show that the benefit of sulfur disappears due to the competing influence of large concentration of chloride ions on the ion-exchanging mechanism of metal ions sorption on mesoporous carbon surfaces. The collected acid dependencies illustrate similar adsorption characteristics for CMK-3 and CMK-3/S in 1-5MHCl concentration range. Sorption of metal ions from diluted aqueous acidic mixtures of actual leached electronic waste demonstrated the feasibility of recovery of gold from such liquors.

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

    EPA Science Inventory

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

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

    E-print Network

    . The Program involves sponsorship and active participation by industry, government, and non-profit and the Bush tax cuts are allowed to expire is compared to several scenarios that include a carbon tax starting

  15. Interaction of aqueous solutions of phenol with commercial activated carbons: an adsorption and kinetic study

    Microsoft Academic Search

    D. M. Nevskaia; A. Santianes; V. Muñoz; A. Guerrero-Ru??z

    1999-01-01

    Three microporous commercial carbons were treated with HCl, H2F2 and HNO3. The effects of these treatments on the specific surface area and porosity, on the surface functional groups and on the adsorption behavior of phenol are studied by means of N2 adsorption at 77 K, temperature-programmed desorption (TPD) and phenol adsorption isotherms, respectively. The results show that there are carbonates

  16. Electrochemical characterization of thin-film LiCoO 2 electrodes in propylene carbonate solutions

    Microsoft Academic Search

    Hajime Sato; Daisuke Takahashi; Tatsuo Nishina; Isamu Uchida

    1997-01-01

    Thin films of LiCoO2 (0.22–1.15 ?m) were prepared by oxidation of metallic cobalt in molten alkali carbonates containing Li+ ions. We report here the behavior of the thin film of LiCoO2 by cyclic voltammetry in propylene carbonate solvent systems, the kinetic analysis using electrochemical impedance spectroscopy (EIS), and potential step chronoamperometry (PSCA). The chemical diffusion coefficients for Li+ ions in

  17. Adsorption studies of chromium (VI) from synthetic aqueous solution by activated carbon derived from Bagasse

    Microsoft Academic Search

    R. Mise Shashikanth; G. M. Shantha

    1993-01-01

    The removal of chromium (VI) from synthetic waste water by adsorption on activated carbon prepared from Bagasse (solid waste produced by sugar industries) was tried to determine the effects of different dosages and different pH.The removal of chromium (VI) from synthetic waste water by adsorption on two types of activated carbon, physical activation and chemical activation (CaCl2, & MgCl2), IRs

  18. Degradation of alkanolamines in gas-treating solutions: Kinetics of Di-2-propanolamine degradation in aqueous solutions containing carbon dioxide

    SciTech Connect

    Kim, C.J.

    1988-01-01

    The rates and products of degradation of di-2-propanolamine (DIPA) were measured at 100-120/sup 0/C in the presence of a controlled amount of CO/sub 2/. DIPA underwent facile degradation, giving 3-(2-hydroxypropyl)-5-methyl-2-oxazolidone (HPMO) as the main product. Hydrolysis of HPMO occurs readily, but its equilibrium concentration increases with increasing amounts of CO/sub 2/ in solution. A kinetic model was derived and compared with the previously established model for diethanolamines (DEA) degradation. The virtual absence of di- or triamino degradation products is the most striking feature of DIPA degradation, which may be contrasted with the facile formation of di- and triamino products from DEA. This difference is discussed in terms of steric inhibition of the reaction, HPMO + DIPA ..-->.. diamino compounds.

  19. Polymer-sorted (6,5) single-walled carbon nanotubes for solution-processed low-voltage flexible microelectronics

    NASA Astrophysics Data System (ADS)

    Bottacchi, Francesca; Petti, Luisa; Späth, Florian; Namal, Imge; Tröster, Gerhard; Hertel, Tobias; Anthopoulos, Thomas D.

    2015-05-01

    We report on low operating voltage transistors based on polymer-sorted semiconducting (6,5) single-walled carbon nanotube (SWNT) networks processed from solution at room temperature. The (6,5) SWNTs were separated from the as-received carbon nanotubes mixture using a polyfluorene-based derivative as the sorting and dispersing polymer agent. As-prepared devices exhibit primarily p-type behavior with channel current on/off ratio >103 and hole mobility ?2 cm2 V-1 s-1. These transistor characteristics enable realization of low-voltage unipolar inverters with wide noise margins and high signal gain (>5). Polymer/(6,5) SWNT transistors were also fabricated on free-standing polyimide foils. The devices exhibit even higher hole mobility (?8 cm2 V-1 s-1) and on/off ratios (>104) while remaining fully functional when bent to a radius of 4 mm.

  20. Capacitance-Voltage Characteristics of Thin-film Transistors Fabricated with Solution-Processed Semiconducting Carbon Nanotube Networks.

    PubMed

    Cai, Le; Zhang, Suoming; Miao, Jinshui; Wei, Qinqin; Wang, Chuan

    2015-12-01

    We report the capacitance-voltage (C-V) measurements on thin-film transistors (TFTs) using solution-processed semiconducting carbon nanotube networks with different densities and channel lengths. From the measured C-V characteristics, gate capacitance and field-effect mobility (up to ~50 cm(2) V(-1) s(-1)) of the TFTs were evaluated with better precision compared with the results obtained from calculated gate capacitance. The C-V characteristics measured under different frequencies further enabled the extraction and analysis of the interface trap density at the nanotube-dielectric layer interface, which was found to increase significantly as the network density increases. The results presented here indicate that C-V measurement is a powerful tool to assess the electrical performance and to investigate the carrier transport mechanism of TFTs based on carbon nanotubes. PMID:26168866

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

    SciTech Connect

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

    2008-08-26

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

  2. Impedance spectroscopy of nonactive metal electrodes at low potentials in propylene carbonate solutions: A comparison to studies of Li electrodes

    SciTech Connect

    Aurbach, D.; Zaban, A. (Bar-Ilan Univ., Ramat Gan (Israel). Dept. of Chemistry)

    1994-07-01

    Surface films formed on nonactive metals (nickel, gold, and silver) in propylene carbonate solutions were investigated using impedance spectroscopy. The salts used included LiClO[sub 4], LiAsF[sub 6], LiBF[sub 4], and LiPF[sub 6], and the impact of their concentration on the properties of the surface films was explored. In addition, the influence of the presence of additives such as O[sub 2], H[sub 2]O, and CO[sub 2] in solutions and the potential of formation on the properties of these surface films was rigorously studied. Using simple methods and simulation programs, it was possible to separate the time constants of the impedance spectra, relate them to different parts of the metal-solution interface, and to calculate the thickness of these surface films from the interfacial capacitances. Following variations of the thickness calculated for the surface films formed in the different systems as a function of applied potential and solution composition, it was possible to study the stability of the surface films, their dissolution rates and the influence of different additives on their stability. For a few systems, ex situ Fourier transform infrared spectroscopy (external reflectance mode) was also applied. The results thus obtained were correlated to previous studies of Li electrodes in the same solutions.

  3. Interactions between viruses and goethite during saturated flow: Effects of solution pH, carbonate, and phosphate

    NASA Astrophysics Data System (ADS)

    Zhuang, Jie; Jin, Yan

    2008-05-01

    Metal oxides have great potential for controlling the fate and transport of viruses in the subsurface and water-treatment systems. The processes, however, are subject to solution chemistry. In this study, a number of column experiments were conducted to examine the effects of solution pH and anions (carbonate and phosphate) on attachment, transport, and inactivation of two bacteriophages (?X174 and MS-2) in goethite-coated sand medium. Removal of both viruses on goethite-coated sand increased as solution pH decreased from 9.3 to 7.5, due mostly to virus inactivation. MS-2, a relatively hydrophobic virus with a lower isoelectric point (3.9), was more sensitive to the change of solution pH than ?X174, a relatively hydrophilic virus with a higher isoelectric point (6.6), in terms of their attachment and inactivation on goethite. About 90% of the MS-2 particles removed by goethite (accounting for 81% of the total input) were inactivated at pH 7.5, whereas all of the removed MS-2 particles (accounting for 10% of the total input) still remained infectious at pH 9.3. In comparison, ~ 74% of the goethite-bound ?X174 particles (accounting for 95% of the total input) lost their infectivity at pH 7.5, in contrast to a complete recovery at pH 9.3 (accounting for 65% of the total input) when the columns were eluted using a beef extract solution (pH 9.5). Presence of phosphate (20 mM H 2PO 4-) in input solution reduced virus attachment and appeared to protect the viruses from being inactivated during transport; this effect was more significant on MS-2 than on ?X174. Specifically, ~ 29% of the ?X174 particles and ~ 49% of MS-2 particles injected into the column were removed during transport. Mass recovery data showed that no ?X174 was inactivated in the presence of phosphate, whereas about 38% of the MS-2 particles attached on goethite lost their infectivity. Conversely, presence of carbonate on goethite increased virus attachment and inactivation due to contribution of additional attachment sites from protonated surface groups of the carbonate ions that were adsorbed on goethite. About 70% of the total input viruses (both ?X174 and MS-2) were removed during transport, of which 35% ?X174 and 85% MS-2 were eventually inactivated.

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

    SciTech Connect

    Zheng, Haibing [Qingdao Technological University, Qingdao 266033 (China)] [Qingdao Technological University, Qingdao 266033 (China); Li, Weihua, E-mail: liweihua@qdio.ac.cn [Qingdao Technological University, Qingdao 266033 (China) [Qingdao Technological University, Qingdao 266033 (China); Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Ma, Fubin [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China)] [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Kong, Qinglin [University of Melbourne, Melbourne 3010 (Australia)] [University of Melbourne, Melbourne 3010 (Australia)

    2014-01-15

    In the present work, the performance of an amino alcohol based surface applied inhibitor was studied by the electrochemical techniques in saturated Ca(OH){sub 2} solutions. The surface morphology of the carbon steel was observed by scanning electron microscope, and the energy diffraction spectrum was also tested. Results showed that the inhibitor used in this work demonstrated obvious inhibition efficiency on the carbon steel in saturated Ca(OH){sub 2} solutions. The inhibition mechanism of the inhibitor lies in the quick adsorption of the active component on carbon steel surface.

  5. 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

  6. 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...

  7. Bioethanol production from rice washing drainage and rice bran.

    PubMed

    Watanabe, Masanori; Takahashi, Makoto; Sasano, Kazuo; Kashiwamura, Takashi; Ozaki, Yuich; Tsuiki, Tomohiro; Hidaka, Harutaro; Kanemoto, Shigeharu

    2009-12-01

    Bioethanol production from rice washing drainage and rice bran derived from a rinse-free process of rice manufacturing was established using the combinations of an enzymatic procedure and an ultra-sonic procedure of rice washing drainage for a sample pre-treatment. The maximum ethanol concentration was attained at 6.2% (v/v). PMID:19914587

  8. 33 CFR 157.124 - COW tank washing machines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  9. 33 CFR 157.124 - COW tank washing machines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

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

    PubMed

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

    2014-11-01

    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

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

    PubMed

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

    2013-01-01

    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

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  13. Oxidised carbon nanotubes as solution processable, high work function hole-extraction layers for organic solar cells

    Microsoft Academic Search

    Ross A. Hatton; N. P. Blanchard; Li Wei Tan; Gianluca Latini; Franco Cacialli; S. Ravi P. Silva

    2009-01-01

    For efficient hole-extraction in solution processed organic solar cells\\u000a the transparent indium-tin oxide (ITO) electrode is invariably\\u000a pre-coated with a thin layer of the high work function conducting\\u000a polymer poly(3,4-ethylenedioxythiophene) doped with\\u000a poly(styrene-sulfonate). Herein we show that thin films of partially\\u000a oxidised multi-wall and single-wall carbon nanotubes are equally\\u000a effective at facilitating hole-extraction in efficient (similar to\\u000a 2.7\\\\%) bulk-heterojunction organic

  14. Effects of activated carbon surface chemistry and pore structure on the adsorption of trace organic contaminants from aqueous solution

    NASA Astrophysics Data System (ADS)

    Li, Lei

    The objectives were (1) to identify activated pore structure and surface chemistry characteristics that assure the effective removal of trace organic contaminants from aqueous-solution, and (2) to develop a procedure to predict the adsorption capacity of activated carbons from fundamental adsorbent and adsorbate properties. A matrix of activated carbon fibers (ACFs) (with three activation levels and four surface chemistry levels) and three commercially available granular activated carbons (GACs) served as the adsorbents. BET surface area, pore size distribution, elemental composition, point of zero charge and infrared spectroscopy data were obtained to characterize the adsorbents. The adsorption of relative hydrophilic methyl tertiary-butyl ether (MTBE) and relative hydrophobic trichloroethene (TCE) were conducted in both ultrapure water and Sacramento-San Joaquin Delta water. The results showed that an effective adsorbent for the removal of micropollutants from water requires (1) a large volume of micropores with widths that are about 1.5 times larger than the kinetic diameter of the target adsorbate, (2) a micropore size distribution that extends to widths that are approximately twice the kinetic diameter of the target adsorbate to prevent pore blockage by NOM, and (3) a hydrophobic pore surface chemistry with the sum of oxygen and nitrogen contents less than 2 to 3 mmol/g. A procedure based on the Polanyi Potential Theory (PPT) was developed to predict the adsorption capacities of activated carbons from fundamental adsorbent and adsorbate properties. A correlation between the coalescing factor for water adsorption and adsorbent oxygen content was developed. Based on this correlation, the PPT yielded reasonable estimates of aqueous phase adsorption capacities for both relatively polar and non-polar adsorbates on both relatively hydrophobic and hydrophilic activated carbons. With the developed procedure, the adsorption capacities of organic compounds that are partially miscible in water can be predicted from (1) N2 and CO2 adsorption isotherms of a given adsorbent, (2) the adsorbent oxygen content, and (3) the molar volume and parachor of the target adsorbate.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  16. Passivity and Pitting Corrosion of X80 Pipeline Steel in Carbonate/Bicarbonate Solution Studied by Electrochemical Measurements

    NASA Astrophysics Data System (ADS)

    Xue, H. B.; Cheng, Y. F.

    2010-12-01

    This work investigated the effects of chloride ions and hydrogen-charging on the passivity and pitting corrosion behavior of X80 pipeline steel in a bicarbonate-carbonate solution by electrochemical and photo-electrochemical techniques. It was found that a stable passivity can be established on the steel in the absence and presence of chloride ions. The hydrogen-charging does not alter the transpassive potential, but increases the passive current density. When chloride ions are contained in the solution, pitting corrosion will be initiated. The pitting potential is independent of the hydrogen-charging. Hydrogen-charging would enhance the anodic dissolution and electrochemical activity of the steel, but does not affect the pitting potential, which indicates that the charged hydrogen is not involved in the pitting initiation. However, hydrogen may accelerate the pit growth. Photo illumination could enhance the activity of the steel electrode, resulting in an increase of photo-induced anodic current density.

  17. Removal of naphthalene from aqueous solution on chemically modified activated carbons.

    PubMed

    Ania, C O; Cabal, B; Pevida, C; Arenillas, A; Parra, J B; Rubiera, F; Pis, J J

    2007-01-01

    The aim of this work was to correlate the textural and chemical features of carbonaceous adsorbents with the adsorption capacity of naphthalene from aqueous phase, at the concentration in which this compound is usually found in wastewater from coke ovens. The study reveals that the adsorption capacity in different carbon materials depends not only on the textural characteristics of the material but also on the functionalities of the activated carbons. The micropores of the adsorbents, particularly those of narrower diameter, were found to be active sites for the retention of naphthalene. In contrast, the modification of the surface chemistry of the carbon materials led to a decrease in the adsorption capacities. Dispersive forces play an important role, and adsorbents with a higher non-polar character have proven to be more efficient for the naphthalene adsorption. This behaviour has been linked to the presence of specific interactions between the basal planes and the polyaromatic structure of the naphthalene molecule. PMID:17126375

  18. Wash tool for well having perforated casing

    SciTech Connect

    Burroughs, T.C.

    1989-03-28

    A tool is described for washing a perforation zone in an earth formation adjacent a perforated casing in a bore hole of a well comprising: a tubular mandrel having an axial flow passage therethrough and adapted to be connected at its upper end to a drill string for receiving pressurized fluid therefrom; an elastomeric tubular packer on each mandrel end section in face to face contact with the outer peripheral surface of the mandrel and defining upper and lower packers; means on the mandrel for securing the upper and lower ends on each of the elastomeric packers in fixed position on the mandrel; a fluid passage through the mandrel wall from the axial flow passage to each of the packers to provide fluid from the mandrel bore to the area between the outer surface of the mandrel and the inner surface of the packers; a second fluid passage in the intermediate section extending through the mandrel wall form the axial flow passage at location between the packers of supplying fluid to the perforation zone adjacent the casing; and means for blocking fluid flow through the second fluid passage at the predetermined fluid pressure, the means being actuated at a second higher predetermined fluid pressure in the mandrel bore to permit fluid flow through the second fluid passage means and the perforated casing to the perforation zone outside the casing. Also described is a method of circulating fluid in a well having a perforated casing at a predetermined depth in the perforation zone.

  19. Eggshell bacterial levels of non-washed and washed eggs from caged and cage-free hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The bacteria levels of non-washed and washed eggs obtained from caged and cage-free laying hens housed on either all shavings or all wire slat floors were determined. On eight sample days (from 22 to 52 weeks at 4 week intervals), 20 eggs were collected from each pen (n=120/sample day). Ten eggs p...

  20. Eggshell bacterial contamination of non-washed and washed eggs from caged and cage-free hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to evaluate the microbiology of non-washed and washed table eggs obtained from caged and cage-free laying hens housed on either all shavings or all wire slat environments. Both Hy-Line W-37 white and Hy-Line brown strains were used. On each of four replication sample days ...

  1. CPS LG 315 Correlation between the phase behavior of ternary systems and removal of oil in the washing process

    Microsoft Academic Search

    F. Schambil; M. J. Schwuger

    1987-01-01

    The correlation between the phase behavior of aqueous solutions of nonionic surfactants and the removal of oil from fabrics has been determined. Model washing experiments with pure and technical grade nonionic surfactants indicated that, in the dispersion ranges of liquid crystals, oil removal is substantially more temperature-dependent compared to micellar or surfactant liquid phases. In this phase region, interfacial tension

  2. Headspace solid-phase microextraction for the evaluation of pesticide residue contents in cucumber and strawberry after washing treatment

    Microsoft Academic Search

    Chai Mee Kin; Tan Guan Huat

    2010-01-01

    The headspace solid-phase microextraction was developed to examine the organophosphorus (diazinon, malathion, chloropyrifos, quinalphos, profenofos) and organochlorine (chlorothalonil, ?-endosulfan and ?-endosulfan) pesticide residues in vegetable (cucumber) and fruit (strawberry) samples. The effects of washing by different solutions were evaluated for the reduction of organophosphorus and organochlorine pesticide residues contents. Gas chromatography with electron capture detection was used to analysis the

  3. Harvest maturity, pre-cutting wash and post-processing dip to improve quality of fresh-cut carambola fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Arkin’ carambola (Averrhoa carambola L.) fruit harvested at color break or full yellow stage were washed with or without an alkaline solution (pH 12), cut to 10 mm slices, dipped in calcium ascorbate (Ca ASA), ascorbic acid (ASA) or water, and packaged in perforated clamshells for up to 14 days sto...

  4. Cadmium ion adsorption on different carbon adsorbents from aqueous solutions. Effect of surface chemistry, pore texture, ionic strength, and dissolved natural organic matter.

    PubMed

    Moreno-Castilla, C; Alvarez-Merino, M A; López-Ramón, M V; Rivera-Utrilla, J

    2004-09-14

    Adsorption of Cd(II) species at pH = 5 was studied on three carbon adsorbents: granular activated carbon, activated carbon fiber, and activated carbon cloth. As-received and oxidized adsorbents were used. Cd(II) adsorption greatly increased after oxidation due to the introduction of carboxyl groups. The use of a buffer solution to control the pH introduced some changes in the surface chemistry of carbons through the adsorption of one of the compounds used, biphthalate anions. The increase in ionic strength reduced Cd(II) uptake on both as-received and oxidized carbons due to a screening of the electrostatic attractions between the Cd(II) positive species and the negative surface charge, which in the case of as-received carbons derived from the biphthalate anions adsorbed and in the oxidized ones from the carboxyl groups. Tannic acid was used as a model compound for natural organic matter. Its adsorption was greatly reduced after oxidation, and most of the carbon adsorbents preadsorbed with tannic acid showed an increase in Cd(II) uptake. In the case of competitive adsorption between Cd(II) species and tannic acid molecules, there was a decrease in Cd(II) uptake on the as-received carbon whereas the contrary occurred with the oxidized carbons. These results illustrate the great importance of carbon surface chemistry in this competitive adsorption process. Finally, under all experimental conditions used, when the adsorption capacity of carbons was compared under the same conditions it increased in the following order: granular activated carbon < activated carbon fiber < activated carbon cloth. PMID:15350085

  5. Photoinduced crystallization of calcium carbonate from a homogeneous precursor solution in the presence of partially hydrolyzed poly(vinyl alcohol)

    NASA Astrophysics Data System (ADS)

    Nishio, Takashi; Naka, Kensuke

    2015-04-01

    Photoinduced crystallization of calcium carbonate (CaCO3) was demonstrated by the photodecarboxylation of ketoprofen (KP, 2-(3-benzoylphenyl)propionic acid) under alkaline conditions (pH 10). In this method, a homogeneous solution comprising KP, calcium chloride, ammonia, and partially hydrolyzed poly(vinyl alcohol) (PVAPS, degree of saponification: 86.5-89.0 mol %) was used as the precursor solution and was exposed to ultraviolet (UV) irradiation for different time periods. Thermogravimetric analysis of the obtained xerogels showed that increasing the UV irradiation time increased the amount of CaCO3 formed and the complete conversion of calcium ions to calcite was achieved after 50 min of UV irradiation. Furthermore, solid phase analyses suggested that nanometer-to-micron-sized calcite crystals were formed and dispersed in the obtained PVAPS matrix. Photoinduced crystallization of CaCO3 from homogenous solution was demonstrated. 2-(3-benzoylphenyl)propionic acid was used as a photoreactive CO2 generator. Partially hydrolyzed poly(vinyl alcohol) worked as a stabilizer in the solution. Complete conversion of Ca2+ to CaCO3 was achieved by UV irradiation for 50 min. Nanometer-to-micron-sized calcites dispersed in the poly(vinyl alcohol) matrix.

  6. Hydrophilic solutes in modified carbon dioxide extraction—prediction of the extractability using molecular dynamic simulation

    Microsoft Academic Search

    Martina Günther; Martin Maus; Karl Gerhard Wagner; Peter Christian Schmidt

    2005-01-01

    Super- and subcritical carbon dioxide (CO2) extractions of crude drugs were simulated by molecular modelling to predict the extractability of different hydrophilic plant constituents under various extraction conditions. The CO2 extraction fluids were simulated either with pure CO2 or with solvent modified CO2 at different pressures and temperatures. Molecular modelling resulted in three different solubility parameters: the total solubility parameter

  7. Supercritical carbon dioxide extraction of metals from aqueous solutions: a review

    Microsoft Academic Search

    Can Erkey

    2000-01-01

    Organometallic chemistry, chemistry of compounds containing metal–carbon bonds or compounds in which an organic molecule (sometimes with a net negative charge) is bonded to a metal atom through an oxygen or nitrogen atom, is one of the most rapidly growing areas of chemical research. Organometallic compounds are being extensively utilized as reagents in preparation and processing of advanced inorganic materials,

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

    SciTech Connect

    Peter Zalupski; Rocklan McDowell; Guy Dutech

    2014-10-01

    Studies on the adsorption characteristics of gold, palladium and platinum on mesoporous carbon (CMK-3) and sulfur-impregnated mesoporous carbon (CMK-3/S) evaluated the benefits/drawbacks of the presence of a layer of elemental sulfur inside mesoporous carbon structures. Adsorption isotherms collected for Au(III), Pd(II) and Pt(IV) on those materials suggest that sulfur does enhance the adsorption of those metal ions in mildly acidic environment (pH 3). The isotherms collected in 1 M HCl show that the benefit of sulfur disappears due to the competing influence of large concentration of hydrogen ions on the ion-exchanging mechanism of metal ions sorption on mesoporous carbon surfaces. The collected acid dependencies illustrate similar adsorption characteristics for CMK-3 and CMK-3/S in 1-5 M HCl concentration range. Sorption of metal ions from diluted aqueous acidic mixtures of actual leached electronic waste demonstrated the feasibility of recovery of gold from such liquors.

  9. Adsorption of Pyridine from Aqueous Solution by Surface Treated Carbon Nanotubes

    Microsoft Academic Search

    Bo Zhao; Duan Qiu

    2007-01-01

    The surface treatment of multi?walled carbon nanotubes (MWCNTs) with acid, heat, ultrasonic, and polyvinyl alcohol has been examined. The original CNTs and four treated CNTs were first used as adsorbents to remove pyridine from water and the adsorption isotherms of pyridine on CNTs were studied. At the same time, the effect of pH, temperature, and the adsorption kinetics on the

  10. Functionalization of carbon nanotubes with proteins and quantum dots in aqueous buffer solutions

    E-print Network

    Falvo, Michael

    , they are not soluble in aqueous buffers. Through noncovalent functionalization with 1-pbase, the MWCNT are stably suspended for a period on the order of weeks. The interaction of the 1-pbase and the MWCNT sidewall and the six-membered carbon rings of the MWCNT.6 The MWCNT were observed to undergo a phase transfer from

  11. Oxidation of Am(III) in carbonate - bicarbonate solution by sodium perxenate

    Microsoft Academic Search

    V. P. Shilov; A. B. Yusov

    1995-01-01

    The oxidation of Am(III) by NaâXeOâ in KHCOâ, KHCOâ + KâCOâ, and KâCOâ solutions is studied by spectrophotometry. In 1.5M solutions (HCOâ⁻ + COâ²⁻) with perxenate concentrations comparable to those of Am, Am(III) is quickly converted to a mixture of Am(IV) + Am(V) + Am(VI). In concentrated KâCOâ solutions (5.9 M), Am(III) is in general not oxidized by perxenate. A

  12. Comparing (semi-) analytic solutions used to model the impact of deep carbon injection on the displacement and pressurization of the resident brine

    NASA Astrophysics Data System (ADS)

    Bandilla, K.; Kraemer, S. R.

    2009-12-01

    Injection of carbon dioxide into deep saline formations is seen as one possible technology for mitigating carbon emissions from utilities. The safety of the sequestered carbon dioxide is the focus of many studies with leakage through faults or abandoned wells as some of the main failure mechanisms. The focus of this study is on the displacement of resident brine and the resulting changes in pressure due to the injection of large volumes of super-critical phase carbon dioxide into the subsurface. The movement of brine becomes important if it travels vertically and reaches an existing or potential underground source of drinking water where an increase in salt content may threaten the viability of the drinking water source. Vertical displacement of brine may occur slowly through confining layers, or more rapidly through faults and abandoned wells. This presentation compares several (semi-) analytic solutions to determine their applicability to the problem of brine pressurization and displacement. The goal is to find ranges of formation parameters (e.g., formation seal conductivity, distance to lateral boundary, … ) for which simplifying assumption are justifiable Each simplification in the conceptual model (e.g., neglecting the lateral boundary turns a bounded domain into an infinite one) leads to a simpler (semi-) analytic solution. The process involves a solution hierarchy from the most complex solution down to the basic Theis solution. A software tool-kit implementing several (semi-) analytic solutions was developed for this study to facilitate the comparison of the solutions.

  13. The Inhibitory Effect of Some Bipyridine Derivatives on the Corrosion Behavior of N80 Carbon Steel in Sulphuric Acid Solutions

    NASA Astrophysics Data System (ADS)

    Liu, Xia; Okafor, Peter C.; Jiang, Bin; Hu, Hongxiang; Zheng, Yugui

    2015-11-01

    The corrosion inhibition characteristics of 2,2?-bipyridine (BIPY) and 2,2?-bipyridine-3,3?-dicarboxylic acid (BIDA), on carbon steel in sulphuric acid solutions was studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques at 20°C, 30°C and 40°C. The results indicate that the organic compounds inhibit the corrosion of mild steel in H2SO4 solutions and the extent of inhibition increases with inhibitor concentration and decreases with temperature. A mixed-inhibition mechanism is proposed for the inhibitive effects of the compounds. The order of inhibition efficiency obtained was BIDA>BIPY. There is a good correlation between the quantum chemical parameters and experimentally determined inhibition efficiency of the inhibitors. The adsorption characteristics of the inhibitor were approximated by Temkin isotherm. Morphological study of the carbon steel electrode surface was undertaken by scanning electron microscope (SEM) and the interfacial species formed on the surface in the presence of inhibitors analyzed by Infrared spectroscopy.

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

    PubMed

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

    2013-08-01

    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

  15. Optimization of nickel adsorption from aqueous solution by using activated carbon prepared from waste apricot by chemical activation

    NASA Astrophysics Data System (ADS)

    Erdo?an, S.; Önal, Y.; Akmil-Ba?ar, C.; Bilmez-Erdemo?lu, S.; Sar?c?-Özdemir, Ç.; Köseo?lu, E.; ?çduygu, G.

    2005-12-01

    Waste apricot supplied by Malatya apricot plant (Turkey) was activated by using chemical activation method and K 2CO 3 was chosen for this purpose. Activation temperature was varied over the temperature range of 400-900 °C and N 2 atmosphere was used with 10 °C/min heat rate. The maximum surface area (1214 m 2/g) and micropore volume (0.355 cm 3/g) were obtained at 900 °C, but activated carbon was predominantly microporous at 700 °C. The resulting activated carbons were used for removal of Ni(II) ions from aqueous solution and adsorption properties have been investigated under various conditions such as pH, activation temperature, adsorbent dosage and nickel concentration. Adsorption parameters were determined by using Langmuir model. Optimal condition was determined as; pH 5, 0.7 g/10 ml adsorbent dosage, 10 mg/l Ni(II) concentration and 60 min contact time. The results indicate that the effective uptake of Ni(II) ions was obtained by activating the carbon at 900 °C.

  16. Hydration in solution is critical for stable oxygen isotope fractionation between carbonate ion and water

    Microsoft Academic Search

    Richard E. Zeebe

    2009-01-01

    Various isotope studies require accurate fractionation factors (?’s) between different chemical compounds in thermodynamic equilibrium. Although numerous isotope systems involve aqueous solutions, the conventional theory is formulated for the gas-phase and predicts incorrect ?’s for many compounds dissolved in water. Here I show that quantum-chemistry calculations, which take into account solute–water interactions, accurately predict, for instance, oxygen isotope fractionation between

  17. Nonideal transport of contaminants in heterogeneous porous media: 10. Impact of co-solutes on sorption by porous media with low organic-carbon contents

    PubMed Central

    Brusseau, M.L.; Schnaar, G.; Johnson, G.R.; Russo, A.E.

    2013-01-01

    The impact of co-solutes on sorption of tetrachloroethene (PCE) by two porous media with low organic-carbon contents was examined by conducting batch experiments. The two media (Borden and Eustis) have similar physical properties, but significantly different organic-carbon (OC) contents. Sorption of PCE was nonlinear for both media, and well-described by the Freundlich equation. For the Borden aquifer material (OC = 0.03%), the isotherms measured with a suite of co-solutes present (1,2-dichlorobenzene, bromoform, carbon tetrachloride, and hexachloroethane) were identical to the isotherms measured for PCE alone. These results indicate that there was no measurable impact of the co-solutes on PCE sorption for this system. In contrast to the Borden results, there was a measureable reduction in sorption of PCE by the Eustis soil (OC = 0.38%) in the presence of the co-solutes. The organic-carbon fractions of both media contain hard-carbon components, which have been associated with the manifestation of nonideal sorption phenomena. The disparity in results observed for the two media may relate to relative differences in the magnitude and geochemical nature of these hard-carbon components. PMID:22717163

  18. Immersion freezing of birch pollen washing water

    NASA Astrophysics Data System (ADS)

    Augustin, S.; Wex, H.; Niedermeier, D.; Pummer, B.; Grothe, H.; Hartmann, S.; Tomsche, L.; Clauss, T.; Voigtländer, J.; Ignatius, K.; Stratmann, F.

    2013-11-01

    Birch pollen grains are known to be ice nucleating active biological particles. The ice nucleating activity has previously been tracked down to biological macromolecules that can be easily extracted from the pollen grains in water. In the present study, we investigated the immersion freezing behavior of these ice nucleating active (INA) macromolecules. Therefore we measured the frozen fractions of particles generated from birch pollen washing water as a function of temperature at the Leipzig Aerosol Cloud Interaction Simulator (LACIS). Two different birch pollen samples were considered, with one originating from Sweden and one from the Czech Republic. For the Czech and Swedish birch pollen samples, freezing was observed to start at -19 and -17 °C, respectively. The fraction of frozen droplets increased for both samples down to -24 °C. Further cooling did not increase the frozen fractions any more. Instead, a plateau formed at frozen fractions below 1. This fact could be used to determine the amount of INA macromolecules in the droplets examined here, which in turn allowed for the determination of nucleation rates for single INA macromolecules. The main differences between the Swedish birch pollen and the Czech birch pollen were obvious in the temperature range between -17 and -24 °C. In this range, a second plateau region could be seen for Swedish birch pollen. As we assume INA macromolecules to be the reason for the ice nucleation, we concluded that birch pollen is able to produce at least two different types of INA macromolecules. We were able to derive parameterizations for the heterogeneous nucleation rates for both INA macromolecule types, using two different methods: a simple exponential fit and the Soccer ball model. With these parameterization methods we were able to describe the ice nucleation behavior of single INA macromolecules from both the Czech and the Swedish birch pollen.

  19. Polymerization in narrow fractions of coal tar wash-oil

    SciTech Connect

    Volkov, E.L.; Akulov, P.V.; Zhilyaev, Yu. A.; Samarkina, A.A.

    1981-01-01

    Certain changes take place in coal tar wash-oil as it is circulated through the benzol hydrocarbons recovery and distillation cycle. It undergoes condensation, loses much of its light distillates content and attains a higher cp. One major problem with coal tar wash-oil is its tendency to form polymers as it circulates through the processing cycle and comes into contact with coke-oven gas. The polymerization rate is affected by a number of factors relating to the composition of the wash-oil, the concentrations in the coke-oven gas of components capable of promoting condensation and the operating conditions in the processing cycle. It has been shown that H/sub 2/S and O/sub 2/ in the coke-oven gas greatly accelerate polymerization processes in the wash-oil. Cyanide compounds and oxides of nitrogen also impair the quality of coal tar wash-oil.The deterioration of wash-oil in circulation leads to a serious rise in its cp and the rapid build-up of deposits on the scrubber packings, with serious effects on the performances of the benzol recovery and distillation sections. We have attempted to evaluate the polymerization tendencies of individual narrow wash-oil fractions. The tests were planned to simulate the conditions under which wash-oil can condense and polymerize. The results show that polymerization proceeds most rapidly in the fractions boiling at 280 to 285 and 285 to 295/sup 0/C. They rapidly increase in density and viscosity and lower the quality of the entire oil. The most stable fractions in respect of polymerization are those boiling up to 270/sup 0/C and up to 280/sup 0/C. These tests have shown that wash-oil boiling up to 280/sup 0/C is the least liable to polymerization; its processing quality is superior and the specific consumption can thus be reduced.

  20. Experimental study of the constituents of space wash water

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    Data are presented that quantify some of the various constituents of human origin that may be expected in space wash water. The experiments were conducted under controlled conditions with a simulated crew of two male and two female subjects. The data show that the expected wash water constituents originating from human secretions are substantially lower than theoretical projections have indicated. Average daily quantities as well as individual extremes are given for both shower and laundry water. In addition, concentrations are presented for a projected model of wash water usage in a space station.

  1. 78 FR 28577 - Notification of Proposed Production Activity: Whirlpool Corporation Subzone 8I; (Washing Machines...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-15

    ...Whirlpool Corporation Subzone 8I; (Washing Machines): Clyde and Green Springs, Ohio Whirlpool...produce standard and high capacity washing machines using certain imported components. The...subassemblies and other unfinished washing machine parts to the list of approved...

  2. Sterilization of Bacillus pumilus spores using supercritical fluid carbon dioxide containing various modifier solutions

    Microsoft Academic Search

    Edison Shieh; Andrzej Paszczynski; Chien M. Wai; Qingyong Lang; Ronald L. Crawford

    2009-01-01

    Supercritical fluid carbon dioxide (SF-CO2) with small amounts of chemical modifier(s) provides a very effective sterilization technique that should be useful for destroying microorganism on heat-sensitive devices such as instruments flown on planetary-bound spacecraft. Under a moderate temperature (50 °C) and pressure (100 atm), spores of Bacillus pumilus strains ATCC 7061 and SAFR 032 can be effectively inactivated\\/eliminated from metal surfaces and

  3. Sequestration of nickel from aqueous solution onto activated carbon prepared from Parthenium hysterophorus L

    Microsoft Academic Search

    Hem Lata; V. K. Garg; R. K. Gupta

    2008-01-01

    In the present study, nickel removal efficiency of sulphuric acid-treated Parthenium carbon (SWC) from simulated wastewater has been investigated. Batch mode adsorption experiments have been conducted by varying pH, nickel concentration, adsorbent dose and contact time. Ni(II) removal was pH-dependent and found to be maximum at pH 5.0. The maximum removal of Ni(II) was achieved within 4h after the start

  4. Chromium(VI) adsorption from aqueous solution by Hevea Brasilinesis sawdust activated carbon

    Microsoft Academic Search

    T. Karthikeyan; S. Rajgopal; Lima Rose Miranda

    2005-01-01

    Adsorption capacity of Cr(VI) onto Hevea Brasilinesis (Rubber wood) sawdust activated carbon was investigated in a batch system by considering the effects of various parameters like contact time, initial concentration, pH and temperature. Cr(VI) removal is pH dependent and found to be maximum at pH 2.0. Increases in adsorption capacity with increase in temperature indicate that the adsorption reaction is

  5. Sorption of chlorophenols from aqueous solution by granular activated carbon, filter coal, pine and hardwood

    Microsoft Academic Search

    G. S. M. Hossain; R. G. McLaughlan

    2012-01-01

    Wood and coal, as low-cost sorbents, have been evaluated as an alternative to commercial granular activated carbon (GAC) for chlorophenol removal. Kinetic experiments indicated that filter coal had a significantly lower rate of uptake (? 10% of final uptake was achieved after three hours) than the other sorbents, owing to intra-particle diffusion limitations. The data fitted a pseudo-second-order model. Sorption

  6. Nucleate boiling heat transfer in aqueous solutions with carbon nanotubes up to critical heat fluxes

    Microsoft Academic Search

    Ki-Jung Park; Dongsoo Jung; Sang Eun Shim

    2009-01-01

    In this study, pool boiling heat transfer coefficients (HTCs) and critical heat fluxes (CHFs) are measured on a smooth square flat copper heater in a pool of pure water with and without carbon nanotubes (CNTs) dispersed at 60°C. Tested aqueous nanofluids are prepared using multi-walled CNTs whose volume concentrations are 0.0001%, 0.001%, 0.01%, and 0.05%. For the dispersion of CNTs,

  7. Capacitive behavior of polycarbazole- and poly(N-vinylcarbazole)-coated carbon fiber microelectrodes in various solutions

    Microsoft Academic Search

    Murat Ates; A. Sezai Sarac

    2009-01-01

    The electrochemical behavior of polycarbazole (PCz) and poly(N-vinyl carbazole) P(NVCz) was investigated by means of electrochemical\\u000a impedance spectroscopy (EIS). Supporting electrolytes made from various combinations of solvents (acetonitrile and propylene\\u000a carbonate) and salts (sodium perchlorate, lithium perchlorate, and tetraethyl ammonium perchlorate) were employed in the investigation.\\u000a Information on the double layer capacitance (Cdl) and specific capacitance (Csp) of P(NVCz) was

  8. Interaction of cataclasis and pressure solution in a low-temperature carbonate shear zone

    Microsoft Academic Search

    Jafar Hadizadeh

    1994-01-01

    The mineralogical and elemental variations across the main shear zone of the Saltville thrust at Sharp Gap in Knoxville, Tennessee, U.S.A., were studied in a suite of deformed and undefromed carbonate rock samples using X-ray diffraction and electron microprobe methods. An examination of the samples for deformation effects at mesoscopic scale and under the optical microscope reveals familiar cataclastic deformation

  9. Kinetics of carbon precipitation and re-solution in low Si-content silicon iron

    NASA Astrophysics Data System (ADS)

    Walz, F.; Wakisaka, T.; Kronmüller, H.

    2005-11-01

    In low Si-charged silicon iron (Fe + 0.1%Si) the kinetics of carbon diffusion, precipitation and redissolution have been carefully studied by means of the magnetic after-effect (MAE) within the temperature range 200 K < Ta < 1100 K. The activation parameters of respective processes have been determined by means of least squares fitting the experimental data. In the presence of substitutionally alloyed Si, the C-Richter MAE gives rise to two Debye-type relaxation peaks - resulting from elementary steps of carbon diffusion combined with reorientation in the (i) unperturbed and (ii) Si-modified Fe matrix - situated near 265 K and 320 K, with activation enthalpies, Qi, of 0.84 eV and 1.08 eV. Two-stage carbon precipitation, obeying first order kinetics, occurs, intensively, near 390 K with the elementary C diffusion enthalpy of 0.84 eV and, rather weakly, near 540 K with an enthalpy of 1.18 eV. The resulting precipitates are discussed in terms of partly intra-grain deposited iron carbide phases (Fe3C) and, mainly, grain-boundary determined C trapping. Decomposition of these precipitates occurring, again, in two stages - situated near 740 K and 950 K, with activation enthalpies of 1.72 and 2.02 eV - leads to a restitution of the state of maximum interstitially dissolved C in the matrix. Of practical importance for silicon steel fabrication is the observation that, after complete C precipitation (Ta . 580 K), the material can be kept in a state of minimum dissolved carbon content - and hence of minimum ac-losses - by not allowing it to warm up above Ta 650 K.

  10. Adsorption of cadmium(II) from aqueous solution by surface oxidized carbon nanotubes

    Microsoft Academic Search

    Yan-Hui Li; Shuguang Wang; Zhaokun Luan; Jun Ding; Cailu Xu; Dehai Wu

    2003-01-01

    Carbon nanotubes (CNTs) were oxidized with H2O2, KMnO4 and HNO3. Their physicochemical properties were investigated by BET N2 adsorption, laser particle examination, Boehm’s titration, zeta potential measurement and cadmium(II) adsorption. The experimental results suggest that cadmium(II) adsorption capacities for three kinds of oxidized CNTs increase due to the functional groups introduced by oxidation compared with the as-grown CNTs. The cadmium(II)

  11. Flexible organic light-emitting diodes with transparent carbon nanotube electrodes: problems and solutions

    Microsoft Academic Search

    Liangbing Hu; Jianfeng Li; Jun Liu; George Grüner; Tobin Marks

    2010-01-01

    We study in detail here the application of transparent, conductive carbon single-wall nanotube (SWNT) networks as electrodes in flexible organic light-emitting diodes (FOLEDs). Overall comparisons of these networks to the commonly used electrodes poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and indium tin oxide (ITO) are made, and SWNT networks are shown to have excellent optical and superior mechanical properties. The effects of protruding

  12. Adsorption from aqueous solutions of chlorinated organic compounds onto activated carbons

    Microsoft Academic Search

    Anna Bembnowska; Robert Pe?ech; Eugeniusz Milchert

    2003-01-01

    The adsorption capacities of five chlorinated organic compounds, chloroform (CHCl3), 1,1,2,2-tetrachloroethane (S-TET), 1,1,2,2-tetrachloroethylene (PER), 1,2-dichloropropane (DCP), and bis(1-chloroisopropyl) ether (BCIPE) for DTO, WD-EXTRA, and AG-5 activated carbons were investigated. Moreover, the effective molecular diameters of investigated chlorocompounds were calculated. The Freundlich and Langmuir equations of adsorption isotherms describe the experimental data with good correlation for each studied system. The equilibrium

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

    SciTech Connect

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

    1999-08-31

    The adsorption properties of a modified activated carbon with various oxygen-and/or nitrogen-containing surface groups toward copper ions was studied. Previously de-ashed and chemically modified commercial activated carbon D-43/1 (carbo-Tech, Essen, Germany) was used. The chemical properties of the modified carbon surface were estimated by standard neutralization titration with HCl, NaOH, and HaOC{sub 2}{sub 5}. The adsorption of Cu{sup 2+} ions on three modified activated carbons from aqueous CuSO{sub 4} solution of various pH was measured. The carbon samples with adsorbed Cu{sup 2+} ions were analyzed by spectroscopic methods (X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy). In addition, an electrochemical measurement (cyclic voltammetry) was performed using powdered activated carbon electrodes. While the modification procedures employed alter the surface only slightly, they strongly influence the surface chemical structure. Basic groups are predominant in the heat-treated samples; acidic functional groups are predominant in the oxidized sample. Both the copper cation adsorption studies and the spectral and electrochemical measurements show that adsorbed ions interact with the carbon surface in different ways. The number of adsorbed ions depends on the nature and quantity of surface acid-base functionalities and on the pH equilibrium in the aqueous solution. The possible mechanisms of interactions between metal ions and carbon surface functionalities are summarized and discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    Hexavalent chromium (Cr(VI)) is well-known to be a strong oxidizer, and is recognized as a carcinogen. Therefore, it is regulated for drinking water, soil, groundwater and sea by the environmental quality standards all over the world. In this study, it was attempted to remove Cr(VI) ion in a carbonic acid solution by the oxidizing slag that was discharged from the normal steelmaking process in an electric arc furnace. After the addition of the slag into the aqueous solution contained Cr(VI) ion, concentrations of Cr(VI) ion and total chromium (Cr(VI) + trivalent chromium (Cr(III)) ions decreased to lower detection limit of them. Therefore, the used slag could reduce Cr(VI) and fix Cr(III) ion on the slag. While Cr(VI) ion existed in the solution, iron did not dissolve from the slag. From the relation between predicted dissolution amount of iron(II) ion and amount of decrease in Cr(VI) ion, the Cr(VI) ion did not react with iron(II) ion dissolved from the slag. Therefore, Cr(VI) ion was removed by the reductive reaction between Cr(VI) ion and the iron(II) oxide (FeO) in the slag. This reaction progressed on the newly appeared surface of iron(II) oxide due to the dissolution of phase composed of calcium etc., which existed around iron(II) oxide grain in the slag.

  15. Potential-induced phase transition of low-index Au single crystal surfaces in propylene carbonate solution.

    PubMed

    Yoshimoto, Soichiro; Kim, Youn-Geun; Sato, Kazuhiro; Inukai, Junji; Itaya, Kingo

    2012-02-21

    In situ scanning tunneling microscopy (STM) was employed to examine the surface structures of Au(111), Au(100), and Au(110) single crystals in propylene carbonate (PC) containing tetrabutylammonium perchlorate (TBAP). All three electrodes exhibited potential-induced phase transition between the reconstructed and unreconstructed (1 × 1) structures at negative and positive potentials, respectively. The potential-induced phase transition of the Au electrode surfaces is attributed to the interaction of the TBA cation and the perchlorate anion at the electrode surface, which is similar to that which takes place in aqueous solutions. In addition to static atomic structures, dynamic processes of both the reconstruction and the lifting of the reconstruction were investigated by means of in situ STM. The lifting of reconstructed Au(111)-(?3 × 22) on Au(111) to the (1 × 1) structure is completed within 1 min at a positive potential. The diffusion of Au atoms on the Au(100) plane in the PC solution proceeds more rapidly than that in the aqueous solution, suggesting that the PC solvent plays an important role in accelerating the diffusion of Au atoms. PMID:22237766

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

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    The Hyperfiltration Wash Water Recovery (HWWR) subsystem, designed to offer low-power high-volume wash water purification for extended mission spacecraft, is discussed in terms of preprototype design and configuration. Heated wash water collected from the shower, hand wash, and laundry flows into a temperature-controlled (374 K) waste storage tank. Two parallel 25 micron absolute filters at the tank outlet remove large particles from the feed stream. A positive displacement feed pump delivers wash water to the hyperfiltration module at a constant flow rate of 0.20 lpm with discharge pressure variations from 4181-7239 Kpa. The hyperfiltration membrane module is a single-pass design including 36 porous stainless steel tubes, and is designed to provide an approximate water recovery rate of 90 percent. Permeate and brine water flows are monitored by flow meters, and removal of urea and ammonia is achieved by adding 15 percent NaOCl solution to the permeate fluid stream. An alternate module design using two diameters of tubing (allowing a smaller pressure drop and a larger membrane area) gave a superior predicted performance over the first module with larger tubing throughout.

  17. Design for dissemination of a low cost washing machine

    E-print Network

    Raduta, Radu

    2008-01-01

    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 ...

  18. Control of helminth contamination of raw vegetables by washing.

    PubMed

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

    2011-02-01

    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

  19. 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...

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

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

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

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

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

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

  2. 21 CFR 133.137 - Washed curd cheese for manufacturing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 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...

  3. 21 CFR 133.137 - Washed curd cheese for manufacturing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...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...

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

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

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

  5. 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

  6. 38. Photocopy of ink and wash rendering by N. G. ...

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

    38. Photocopy of ink and wash rendering by N. G. Starkwether in collection of Mr. & Mrs. Richard T. Pratt, Camden REAR ELEVATION OF W. C. PRATT'S COUNTRY SEAT - Camden, Rappahannock River, Port Royal, Caroline County, VA

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

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

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

  8. 20. Photocopy of ink and wash drawing by Richard Upjohn, ...

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

    20. Photocopy of ink and wash drawing by Richard Upjohn, circa 1839, in Avery Library, Columbia University FIRST AND SECOND FLOOR PLANS - Kingscote, Bellevue Avenue & Bowery Street, Newport, Newport County, RI

  9. 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

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

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

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

  11. 11. VIEW LOOKING OUT UPPER LEVEL WINDOW OF WASH HOUSE ...

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

    11. VIEW LOOKING OUT UPPER LEVEL WINDOW OF WASH HOUSE SHOWING SLACK COAL STORAGE TANK - Kaymoor Coal Mine, South side of New River, upstream of New River Gorge Bridge, Fayetteville, Fayette County, WV

  12. PARTS WASHING ALTERNATIVES STUDY - UNITED STATES COAST GUARD

    EPA Science Inventory

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

  13. Bioherbicidal activity from washed spores of Myrothecium verrucaria.

    PubMed

    Weaver, Mark A; Boyette, C Douglas; Hoagland, Robert E

    2012-05-01

    The fungal plant pathogen, Myrothecium verrucaria, is highly virulent to several important weed species and has potential utility as a bioherbicide. However the production of macrocyclic trichothecene mycotoxins by this fungus presents significant safety concerns. It was discovered that trichothecenes are removed from M. verrucaria spores by repeated washes with water. These washed spores retained bioherbicidal efficacy against kudzu when tested in field trials and on sicklepod when tested under greenhouse conditions. Changes in the growth medium combined with washing spores with water resulted in greater than 95% reduction in roridin A and verrucarin A. Washing spores reduced trichothecene concentrations in spore preparations with no significant effect on plant biomass reduction, thus demonstrating the possibility of M. verrucaria formulations with improved safety to researchers, producers and applicators. PMID:22806015

  14. Evaluation of corrosion protection of carbon black filled fusion-bonded epoxy coatings on mild steel during exposure to a quiescent 3% NaCl solution

    Microsoft Academic Search

    Y. H. Wei; L. X. Zhang; W. Ke

    2007-01-01

    Carbon black (CB) was mixed with fusion-bonded epoxy (FBE) coatings to generate a series of formulations with 0.5–4% by weight of carbon black. The degradation of these FBE coatings on mild steel exposed to a quiescent 3% NaCl solution was monitored using electrochemical impedance spectroscopy (EIS). The experimental results showed that the electrochemical behaviour of coated systems changed dramatically when

  15. Radiation-Chemical Reduction of Ni2+ Ions in Aqueous Solutions Saturated with Carbon Monoxide

    Microsoft Academic Search

    N. L. Sukhov; A. F. Seliverstov; B. G. Ershov

    2002-01-01

    Under the action of ionizing radiation on aqueous solutions containing noble (gold, silver, platinum, etc.) and other (cadmium, lead, cobalt, nickel, etc.) metal ions and organic compounds (alcohols, formates, etc.), the ions undergo reduction with the formation of metal precipitates (for example, see [1] and references therein). Using the pulse radiolysis technique [2, 3], we showed that short-lived metal atoms

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    As a new nano-scale functional material, it is necessary to achieve a uniform distribution in the composites for gaining the CNFs' excellent reinforcing effect. In this paper, CNFs were purified by the method of high temperature annealing treatment. Six surfactants, methylcellulose (MC), hydroxypropyl methylcellulose (HPMC), sodium dodecyl sulfate (SDS), dodecylamine (DDA), N, N-dimethyl formamide (DMF) and cetyltrimethyl ammonium bromide (CTAB) were used individually and combinatorially in a certain concentration to disperse the CNFs in aqueous solution. To achieve a good dispersion of the CNFs, a method utilizing ultrasonic processing was employed. The CNFs treated by the method of high temperature annealing treatment were characterized by differential thermal analysis (DTA) and thermogravimetry analysis (TGA), and the ultrasonication-driven dispersion of CNFs in aqueous solutions were monitored by UVvis spectroscopy and transmission electron microscopy (TEM). The experiments reveal that the method of high temperature annealing treatment purified the CNFs and the maximum achievable dispersion of CNFs corresponds to the maximum UV absorbance of the solution. All results show that the surfactants mixture of MC and SDS in a certain concentration of 0.4 and 2.0 g/L has the maximum dispersion effect on CNFs in aqueous solution, the optimum concentration ratio of MC, SDS, and CNFs was 2: 10: 1.

  17. Decolorization of anaerobically digested molasses spent wash by Pseudomonas putida

    Microsoft Academic Search

    M. Ghosh; A. Ganguli; A. K. Tripathi

    2009-01-01

    The distillery wastewater (spent wash) contains dark brown colored recalcitrant organic compounds that are not amenable to\\u000a conventional biological treatment. The characteristic recalcitrance to decolorization is due to the presence of brown melanoidin\\u000a polymers. In the present study, feasibility of using Pseudomonas putida putida strain U for decolorization of spent wash was demonstrated. Batch cultures of P. putida decolourized spent

  18. Direct Evidence of Washing out of Nuclear Shell Effects

    E-print Network

    A. Chaudhuri; T. K. Ghosh; K. Banerjee; S. Bhattacharya; Jhilam Sadhukhan; C. Bhattacharya; S. Kundu; J. K. Meena; G. Mukherjee; R. Pandey; T. K. Rana; P. Roy; T. Roy; V. Srivastava; P. Bhattacharya

    2015-04-17

    Constraining excitation energy at which nuclear shell effect washes out has important implications on the production of super heavy elements and many other fields of nuclear physics research. We report the fission fragment mass distribution in alpha induced reaction on an actinide target for wide excitation range in close energy interval and show direct evidence that nuclear shell effect washes out at excitation energy ~40 MeV. Calculation shows that second peak of the ?fission barrier also vanishes around similar excitation energy.

  19. Guilt and Compulsive Washing: Experimental Tests of Interrelationships

    Microsoft Academic Search

    Jesse R. CougleAmy; Amy R. Goetz; Kirsten A. Hawkins; Kristin E. Fitch

    Recent evidence suggests a potentially important relationship between guilt and compulsive washing. The present studies sought\\u000a to clarify this relationship. In Study 1, we examined whether washing reduced guilt. Following guilt induction, 132 non-clinical\\u000a participants were randomized to one of three conditions: hand-wiping, straightening of clutter, or a control task. Contrary\\u000a to predictions, analyses indicated no differences between conditions in

  20. BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTH. THE ...

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

    BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTH. THE OUTSIDE FACE OF THE NORTH WALL OF SETTLING RESERVOIR NO. 3 IS SEEN AT THE RIGHT. THE SETTLING RESERVOIR IS ELEVATED ABOVE THE FILTERING RESERVOIR TO ACHIEVE GRAVITY WATER FLOW FROM THE SETTLING RESERVOIR INTO THE FILTERING RESERVOIR. - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

  1. Effective Washing Conditions Reduce Water Usage for Surimi Processing

    Microsoft Academic Search

    Tein M. Lin; Jae W. Park

    1997-01-01

    Possible minimization of water usage for leaching was investigated by reduced water\\/meat (W\\/M) ratio with increased washing cycles (WQ and washing time (WT). Increased WT did not enhance removal of sarcoplasmic proteins once equilibrium was reached, while the increased WC continuously removed residual sarcoplasmic proteins from the mince. No significant loss of myoFibrillar proteins occurred at the low W\\/M ratio

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

    PubMed

    Tang, Hailong; Erzat, Aris; Liu, Yangsheng

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  4. Investigation on the electronically excited state properties of multiwalled carbon nanotube (MDDA) in solution

    Microsoft Academic Search

    Juan Feng; Zujun Yang; Zhenglong Ren

    2006-01-01

    Sub-microsecond time-resolved absorption spectroscopy has been used to study the electronically excited state behavior of\\u000a soluble multiwalled carbon nanotube (MWNTsCON((CH2)9-CH3)2, denoted as MDDA) in chloroform, toluene and cyclohexane. Following pulsed photo-excitation of MDDA at 355 nm, three major\\u000a spectral components are clearly identified with the help of global analysis carried out over 7 representative kinetics curves\\u000a from 450 to 700

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

    SciTech Connect

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

    1996-12-31

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

  6. CORROSION TESTING OF CARBON STEEL IN OXALIC ACID CHEMICAL CLEANING SOLUTIONS

    SciTech Connect

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

    2011-10-14

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

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

    PubMed

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

    2003-03-01

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

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

    PubMed

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

    2013-01-01

    Black carbon (BC) particles were removed from experimental flue gas by the surfactant solutions of sodium dodecylbenzene sulfonate (SDBS), hexadecyl trimethyl ammonium bromide (CTAB), fatty alcohol polyoxyethylene ether-9 (AEO-9) and polyoxy ethrlene nonyl phinyl ether-10 (TX-10), as well as AEO-9-SDBS, AEO-9-CTAB and SDBS-CTAB, in a new type of umbrella plate scrubber. Among the four independent surfactants, AEO-9 has the lowest surface tension, 35.9 mN/m, which resulted in the highest BC removal ratio among the alone surfactants. The experimental conditions were as follows: dust concentration = 3000 mg/m3; gas velocity = 14 m/s; liquid-gas ratio = 0.80 l/m3; and gas flow = 400 m3/h. When the mole ratio of the mixed surfactants was 1:1, the lowest surface tension could be detected among the studied mixed surfactants. According to the molecular interaction parameters (beta) and the mole ratio of surfactant 1 in the mixture (x1), the synergistic effects of AEO-9-SDBS and SDBS-CTAB solutions were obviously higher than those of AEO-9-TX-10 and AEO-9-CTAB. Therefore, AEO-9-SDBS solution had the lowest surface tension among the mixtures due to its beta < 0 and x1 = 0.85. The mixture solution of AEO-9-SDBS (1:1 mole ratio, 0.2 mmol/l) yielded the highest BC removal ratio, about 99.8%, and it was about 12% higher than that of only water, which was about 87.9%. The calculated critical micelle concentration was almost the same as that of the experimental concentration when the related equation was corrected by beta. PMID:23530320

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

    PubMed

    Khun, N W; Liu, E

    2010-07-01

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

  10. Heteroepitaxial Growth of a Manganese Carbonate secondary Nano-Phase on the (101{sub 4}) Surface of Calcite in Solution

    SciTech Connect

    Lea, Alan S.; Hurt, Thomas T.; El-Azab, Anter; Amonette, James E.; Baer, Donald R.

    2003-01-23

    Heteroepitaxy of a manganese carbonate phase with nanometer dimensions on the (101{sub 4}) surface of calcite (CaCO3) using an AFM has been observed in solution during dissolution of calcite when the ion activity product of Mn2? and CO32- nears the solubility limit of MnCO3. Growth-rate observations at different Mn concentrations, coupled with XPS and EPR measurements, suggest that the resulting phase is Mn05Ca05CO3. These islands, while growing many microns in length along the[22{sub 1}] direction, have a uniform width in the range of 120-240 nm and a uniform height of approximately 2.7 nm, corresponding to nine atomic layers. The islands cease growing when they encounter step edges and have been observed to dissolve when undercut by a growing etch pit.

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

    SciTech Connect

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

    1996-01-01

    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.

  12. Femtosecond laser-induced size reduction of carbon nanodots in solution: Effect of laser fluence, spot size, and irradiation time

    NASA Astrophysics Data System (ADS)

    Nguyen, Vanthan; Yan, Lihe; Si, Jinhai; Hou, Xun

    2015-02-01

    Photoluminescent carbon nanodots (C-dots) with size tunability and uniformity were fabricated in polyethylene glycol (PEG200N) solution using femtosecond laser ablation method. The size distributions and photoluminescence (PL) properties of C-dots are well controlled by adjusting the combined parameters of laser fluence, spot size, and irradiation time. The size reduction efficiency of the C-dots progressively increases with decreasing laser fluence and spot size. The optimal PL spectra are red-shifted and the quantum yields decrease with the increase in C-dots size, which could be attributed to the more complex surface functional groups attached on C-dots induced at higher laser fluence and larger spot size. Moreover, an increase in irradiation time leads to a decrease in size of C-dots, but long-time irradiation will result in the generation of complex functional groups on C-dots, subsequently the PL spectra are red-shifted.

  13. In situ electrostatic assembly of CdS nanoparticles onto aligned multiwalled carbon nanotubes in aqueous solution

    NASA Astrophysics Data System (ADS)

    Cai, Zhao-Xia; Yan, Xiu-Ping

    2006-08-01

    A simple method is described for the electrostatic assembly of CdS nanoparticles onto oxidized aligned multiwalled carbon nanotubes (MWCNTs) in aqueous solution. The method is convenient to control and allows the formation of a stable, water-soluble suspension of CdS/aligned-MWCNT heterostructures. The prepared CdS/aligned-MWCNT heterostructures are characterized by transmission electron microscopy (TEM), high-resolution TEM (HRTEM), energy dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD) and Fourier transform infrared spectrometry (FT-IR). The fluorescence and UV absorption spectral properties of the hybrid material demonstrate electron transfer from CdS nanoparticles to aligned-MWCNTs, which implies its potential applications in photovoltaic cells, photocatalysis, and solar energy conversion.

  14. Ultrasonic assisted removal of sunset yellow from aqueous solution by zinc hydroxide nanoparticle loaded activated carbon: Optimized experimental design.

    PubMed

    Roosta, M; Ghaedi, M; Sahraei, R; Purkait, M K

    2015-07-01

    The efficiency of zinc hydroxide nanoparticle loaded on activated carbon (Zn(OH)2-NP-AC) in the removal of sunset yellow from aqueous solutions using ultrasonic-assisted adsorption method was investigated. This nanomaterial was characterized using different techniques such as SEM, XRD and UV-vis spectrophotometer. A central composite design (CCD) was used for the optimization of significant factors using response surface methodology (RSM). Under the best conditions (5.2min of sonication time, pH3, 0.023g of adsorbent and 30mgL(-1) of SY), Langmuir model was fitting the experimental equilibrium data well. The small amount of proposed adsorbent (0.023g) is applicable for the successful removal of SY (>97%) in short time (5min) with high adsorption capacity (83-114mgg(-1)). PMID:25953543

  15. Thermodynamics and phase relations in refractory metal solid solutions containing carbon, nitrogen, and oxygen

    Microsoft Academic Search

    Eckehard Fromm; Hermann Jehn

    1972-01-01

    The refractory metals Nb, Ta, Mo, and W dissolve C, N, and O by forming interstitial solid solutions. The concentration of\\u000a these components can be increased or decreased by annealing treatments, depending on the partial pressure of gases such as\\u000a N2, O2, H2O, CH4, or CO and on the temperature of the specimen. New results in binary and ternary systems

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

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

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

  17. Metal-based Nanoparticle Synthesis from the Rapid Expansion of Carbon Dioxide Solutions

    SciTech Connect

    Fulton, John L.; Matson, Dean W.; Pecher, Klaus H.; Amonette, James E.; Linehan, John C.

    2006-02-01

    Synthesis of 10 to 500 nm diameter Fe-based nanoparticles is described. Nanometer-sized droplets of iron carbonyl are generated by the rapid expansion of CO2-based supercritical fluid solutions and are photolyzed in-flight using a UV lamp to remove the carbonyl groups. Solid metal particles are collected electrostatically. Upon air oxidation, the iron particles react rapidly to produce an iron oxide phase. Mo-based nanoparticles were similarly produced using a Mo(Co)6 precursor.

  18. Partition coefficients of cobalt chelates and chelating agents between aqueous solutions and supercritical carbon dioxide

    Microsoft Academic Search

    F Gervais; C Perre; S Sarrade; L Barna; P Moszkowicz; S Barguès

    2003-01-01

    Distribution (or partition) coefficients (Dx) of several chelating agents and cobalt-chelates between aqueous phases and SC CO2 were determined. ?-Diketones and dithiocarbamates fluorinated or not were the investigated chelating agents for cobalt. Different solute concentrations and different aqueous phase pH values were experienced for fixed operating conditions at 270 bar pressure and 50°C temperature. The results obtained were compared with

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

    PubMed

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

    2014-11-18

    Adsorption of three selected pharmaceuticals and personal care products (PPCPs) (ketoprofen (KEP), carbamazepine (CBZ), and bisphenol A (BPA)) by two reduced graphene oxides (rGO1 and rGO2) and one commercial graphene was examined under different solution conditions. Single-walled carbon nanotubes (SWCNTs), multiwalled carbon nanotubes (MWCNTs), and powdered graphite were also investigated for comparison. All adsorption isotherms followed the order of SWCNTs > rGO1 > rGO2 > MWCNTs > graphene > graphite, consistent with the orders of their surface areas and micropore volumes. After surface area normalization, adsorption affinities of the three PPCPs onto graphenes were lower than onto graphite, suggesting incomplete occupation for adsorption sites because of the aggregation of graphene sheets and the presence of oxygen-containing functional groups. The observed pH effects on adsorption correlated well with the pH-regulated distribution of the protonated neutral species of the three PPCPs. Increasing ionic strength from 0 to 20 mM increased KEP adsorption due to the electrostatic screening by Na(+) and Ca(2+). Both humic acid (HA) and sodium dodecylbenzenesulfonate (SDBS) suppressed PPCPs adsorption to all adsorbents, but their impacts onto graphenes were lower than those onto CNTs because of their lower adsorption by graphenes. More severe HA (or SDBS) effect was found on negatively charged KEP at the tested solution pH 6.50 due to the electrostatic repulsion between the same charged KEP and HA (or SDBS). The findings of the present study may have significant implications for the environmental fate assessment of PPCPs and graphene. PMID:25353977

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

    PubMed

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

    2013-12-01

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

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

    USGS Publications Warehouse

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

    1995-01-01

    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.

  2. Surface effects on the electrochemistry of iron and carbon steel electrodes in aqueous CO{sub 2} solutions

    SciTech Connect

    Videm, K.; Kvarekvaal, J. [Univ. of Oslo (Norway). Center for Materials Research; Perez, T.; Fitzsimons, G. [FUDETEC, Campana (Argentina). Center for Industrial Research

    1996-08-01

    The objective was to generate knowledge about the effects of the corrosion induced changes of the surface on the corrosion and electrochemical kinetics of carbon steels and pure iron exposed to aqueous CO{sub 2} solutions. Besides its fundamental interest, the knowledge is needed for the development of better steels and for working out better models for the prediction of CO{sub 2} corrosion of carbon steel exposed to the corrosive water phase from oil wells. The exposures were carried out at 25 to 100 C with CO{sub 2} partial pressure of 0.65 to 3.2 bar. The paper discusses the fundamentals of the anodic and cathodic reactions and the consequences of the formation of corrosion films of Fe{sub 3}C and FeCO{sub 3}. Effects of microstructure and chromium additions to the steel are taken up. The influence of very small concentrations of sulfide ions (e.g., 20 {micro}Mol/l) is also briefly treated.

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

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    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.

  5. Determination of electrochemical parameters and corrosion rate for carbon steel in un-buffered sodium chloride solutions using a superposition model

    Microsoft Academic Search

    Luis Cáceres; Tomás Vargas; Leandro Herrera

    2007-01-01

    Corrosion of carbon steel in un-buffered NaCl solutions was studied applying linear potential sweep technique to a rotating disk electrode. Current–potential curves were obtained from linear potential sweep at a rate of 1mVs?1 in solution with concentrations in the range 0.02–1M NaCl and rotation rates in the range 170–370rads?1, at 22°C. Potential sweeps, which were conducted in the potential range

  6. Study of acid orange 7 removal from aqueous solutions by powdered activated carbon and modeling of experimental results by artificial neural network

    Microsoft Academic Search

    Soheil Aber; Nezameddin Daneshvar; Saeed Mohammad Soroureddin; Ammar Chabok; Karim Asadpour-Zeynali

    2007-01-01

    In this work, removal of acid orange 7 (AO7) by powdered activated carbon, from aqueous solutions with initial concentrations of 150 ppm to 350 ppm and initial pH values of 2.8, 5.8, 8.0 and 10.5 at 25°C was studied. Experiments were done in batch mode and the experimental solutions were agitated periodically. All concentrations were measured spectrophotometrically at 483 nm

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

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

    PubMed

    Chen, Qingchun; Wu, Qingsheng

    2015-02-11

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

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

    PubMed

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

    2013-12-11

    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

  10. WASHING CONDITIONS AFFECT THE INACTIVATION OF ESCHERICHIA COLI O157:H7 ON FRUIT SURFACES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Washing with sanitizers is an important step to reduce microbial populations during postharvest handling of produce. The washing efficacy of sanitizers has been extensively studied in the contexts of produce-to-sanitizer ratio, washing time, and washing temperature. Little attention has been paid to...

  11. Solution chemistry approach to fabricate vertically aligned carbon nanotubes on gold wires: towards vertically integrated electronics

    NASA Astrophysics Data System (ADS)

    Flavel, Benjamin S.; Yu, Jingxian; Ellis, Amanda V.; Quinton, Jamie S.; Shapter, Joseph G.

    2008-11-01

    A monolayer of hexadecyltrichlorosilane, 3-aminopropyltriethoxysilane or 3-mercaptopropyltrimethoxysilane was self-assembled onto a p-type silicon (100) substrate to provide a resist for electrochemical anodization with an atomic force microscope cantilever. Silane treatment of the oxide nanostructures created by anodization lithography allowed for the creation of a chemically heterogeneous surface, containing regions of -NH2 or -SH surrounded by -CH3 functionality. These patterned regions of -NH2 or -SH provided the point of attachment for citrate-stabilized gold colloid nanoparticles, which act as 'seed' particles for the electro-less deposition of gold. This has allowed the creation of gold wires on a silicon surface. Carbon nanotubes, with high carboxylic acid functionality, were vertically immobilized on the patterned gold wires with the use of a cysteamine monolayer and a condensation reaction. Such a material may prove useful in the creation of future vertically integrated electronic devices where it is desirable for electron transport to be in three dimensions and this electron transport is demonstrated with cyclic voltammetry.

  12. The Dissolution of Synthetic Na-Boltwoodite in Sodium Carbonate Solutions

    SciTech Connect

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

    2006-09-01

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

  13. Multiwalled carbon nanotubes supported palladium-phosphorus nanoparticles for ethanol electrooxidation in alkaline solution

    NASA Astrophysics Data System (ADS)

    Wu, Ke; Mao, Xinbiao; Liang, Yan; Chen, Yu; Tang, Yawen; Zhou, Yiming; Lin, Jun; Ma, Chunan; Lu, Tianhong

    2012-12-01

    Multiwalled carbon nanotubes (MWCNTs) supported palladium-phosphorus nanoparticles (Pd-P/MWCNTs) catalyst is synthesized by homogeneous precipitation-reduction reaction method using hypohosphite as reducing agent. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis confirm that some P has entered into the crystal lattice of Pd and thus the Pd-P alloy is formed. Transmission electron microscopy (TEM) images reveal that Pd-P nanoparticles are uniformly dispersed on MWCNTs and the average particle size of Pd-P/MWCNTs catalyst is very similar to that of Pd/MWCNTs catalyst prepared by using NaBH4 as reducing agent. Cyclic voltammetric and chronoamperometric experiments show that the electrocatalytic activity and long-term operation stability of Pd-P/MWCNTs catalyst are better than that of Pd/MWCNTs catalyst for ethanol electrooxidation in alkaline media, indicating that the addition of P in Pd nanoparticles can promote the electrocatalytic activity and stability of Pd catalyst for ethanol electrooxidation.

  14. Structurization of a titanium-based composite material in the interaction between solid solution of carbon in ?-SiC and titanium

    Microsoft Academic Search

    N. F. Gadzyra; N. K. Davidchuk

    2008-01-01

    The paper examines the high-temperature interaction between powder solid solution of carbon in ?-SiC and powder titanium hydride.\\u000a The structure of the composite materials sintered from the synthesized products and titanium matrix is studied. It is established\\u000a that the composite alloy has high mechanical characteristics.

  15. Hand Washing Among School Children in Bogotá, Colombia

    PubMed Central

    Lopez-Quintero, Catalina; Freeman, Paul

    2009-01-01

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

  16. Treatment of tunnel wash water and implications for its disposal.

    PubMed

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

    2014-01-01

    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

  17. Technical bases DWPF Late Washing Facility. Revision 1

    SciTech Connect

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

    1992-08-10

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

  18. 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

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

    2005-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

  20. Retromer-mediated endosomal protein sorting: all WASHed up!

    PubMed

    Seaman, Matthew N J; Gautreau, Alexis; Billadeau, Daniel D

    2013-11-01

    Endosomal protein sorting governs the fate of many physiologically important proteins involved in a panoply of cellular functions. Recent discoveries have revealed a vital role for endosomally localised branched actin patches in facilitating protein sorting. The formation of the actin patches has been shown to require the function of the WASH complex - the major endosomal actin polymerisation-promoting complex - which stimulates the activity of the ubiquitously expressed Arp2/3 complex. Another key component of the endosomal protein-sorting machinery is the retromer complex. Studies now show that retromer mediates the recruitment of the WASH complex and its regulators to endosomes. In this review, recent progress in understanding the role of the WASH complex along with retromer in endosomal protein sorting is discussed. PMID:23721880

  1. Soil washing results for mixed waste pond soils at Hanford

    SciTech Connect

    Gerber, M.A.

    1991-09-01

    Soil washing technology was assessed as a means for remediating soil contaminated with mixed wastes primarily composed of heavy metals and radionuclides. The soils at the US Department of Energy's Hanford Site are considered suitable for soil washing because of their relatively low quantities of silt and clay. However, in a limited number of soil washing experiments using soils from different locations in the north pond of the 300 Area, the degree of decontamination achieved for the coarse fraction of the soil varied considerably. Part of this variation appears to be due to the presence of a discrete layer of contaminated sediment found in some of the samples. 7 refs., 2 figs., 4 tabs.

  2. Gravity and magnetic study of Yucca Wash, southwest Nevada

    SciTech Connect

    Langenheim, V.E.; Ponce, D.A.; Oliver, H.W.; Sikora, R.F. [Geological Survey, Menlo Park, CA (United States)

    1993-12-31

    Gravity and ground magnetic data were collected along five traverses across and one traverse along Yucca Wash in the southwest quadrant of the Nevada Test Site. Two additional ground magnetic profiles were collected approximately 100 m to either side of the longitudinal profile. These data do not indicate major vertical offsets greater than 100 m using a density contrast of 0.2 to 0.3 g/cm{sup 3} along the proposed Yucca Wash fault. A broad magnetic high coincides with the location of the hydrologic gradient. Density profiling, a technique used to determine the average density of small topographic features, suggests that the density of near-surface material in the vicinity of Yucca Wash is about 2.0 g/cm{sup 3}.

  3. Wash-Out in N_2-dominated leptogenesis

    E-print Network

    Florian Hahn-Woernle

    2010-08-22

    We study the wash-out of a cosmological baryon asymmetry produced via leptogenesis by subsequent interactions. Therefore we focus on a scenario in which a lepton asymmetry is established in the out-of-equilibrium decays of the next-to-lightest right-handed neutrino. We apply the full classical Boltzmann equations without the assumption of kinetic equilibrium and including all quantum statistical factors to calculate the wash-out of the lepton asymmetry by interactions of the lightest right-handed state. We include scattering processes with top quarks in our analysis. This is of particular interest since the wash-out is enhanced by scatterings and the use of mode equations with quantum statistical distribution functions. In this way we provide a restriction on the parameter space for this scenarios.

  4. Increasing hand washing compliance with a simple visual cue.

    PubMed

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

    2014-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  6. 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

    Siegel, D.I.

    1992-04-09

    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.

  7. Effects of interstitial solute atoms on the very low strain-rate deformations for an IF steel and an ultra-low carbon steel

    SciTech Connect

    Tsuchida, N. [School of Engineering, University of Hyogo, 2167, Shosha, Himeji 671-2201 (Japan)]. E-mail: tsuchida@eng.u-hyogo.ac.jp; Baba, E. [Materials Information Technology Station, National Institute for Materials Science, 2-2-54, Nakameguro, Meguro 153-0061 (Japan); Nagai, K. [Steel Research Center, National Institute for Materials Science, 1-2-1, Sengen, Tsukuba 305-0047 (Japan); Tomota, Y. [Graduate School of Science and Engineering, Ibaraki University, 4-12-1, Nakanarusawa, Hitachi 316-8511 (Japan)

    2005-01-10

    In order to investigate the effects of interstitial solute atoms on very low strain-rate deformation of steel by using an interstitial free (IF) steel and an ultra-low carbon (ULC) steel, creep tests and crosshead-arresting tests were conducted at room temperature. The concentrations of solute carbon and solute nitrogen for the ULC steel were 8 and 12 ppm, respectively, and were about 20 times higher than those of the IF steel. The static tensile tests showed that the tensile properties in the two steels were quite similar. However, the room temperature creep test and the crosshead-arresting test showed that their deformation behaviors were significantly different. The very low strain-rate deformation of the ULC steel was associated with the so-called dynamic strain aging, which appeared at a critical strain rate of 5.8 x 10{sup -8} s{sup -1}.

  8. Correlation and prediction of the solubility of carbon dioxide in a mixed alkanolamine solution

    SciTech Connect

    Li, Y.G.; Mather, A.E. (Univ. of Alberta, Edmonton (Canada). Dept. of Chemical Engineering)

    1994-08-01

    Aqueous alkanolamine solutions are frequently used for the removal of acidic gases, such as CO[sub 2] and H[sub 2]S from industrial and natural gases. The Clegg-Pitzer equations, expressed on a mole fraction basis, comprise an extended Debye-Hueckel term which is a function of composition and a Margules expansion carried out to the three-suffix level, with some simplifications are used to correlate and predict the vapor-liquid equilibrium data for the CO[sub 2]-mixed amine aqueous system. The interaction parameters determined from data for the binary and ternary (single amine) systems can be used to predict the quaternary mixed amine system without any additional parameters. The model is applied to the CO[sub 2]-MDEA-MEA-H[sub 2]O system containing three neutral solvents (MDEA, MEA, and H[sub 2]O) and four ionic species (MDEAH[sup +], MEAH[sup +], HCO[sub 3][sup [minus

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

    E-print Network

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

  10. BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTH. THE ...

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

    BLAISDELL SLOW SAND FILTER WASHING MACHINE. VIEW LOOKING SOUTH. THE SUCTION (INTAKE) HOSE IS SEEN AT THE LEFT RESTING ON THE FILTER BED SURFACE; THE DISCHARGE HOSE IS AT THE RIGHT, RUNNING FROM THE BOTTOM OF THE CENTRAL VERTICAL AXLE TO THE CENTRIFUGAL PUMP. FROM THE PUMP WATER IS DISCHARGED THROUGH THE HORIZONTAL PIPE LOCATED UNDER THE EDGE OF PLATFORM DECK INTO THE WASTE-WATER TROUGH (NOT SEEN IN THIS VIEW). - Yuma Main Street Water Treatment Plant, Blaisdell Slow Sand Filter Washing Machine, Jones Street at foot of Main Street, Yuma, Yuma County, AZ

  11. Direct evidence of "washing out" of nuclear shell effects

    NASA Astrophysics Data System (ADS)

    Chaudhuri, A.; Ghosh, T. K.; Banerjee, K.; Bhattacharya, S.; Sadhukhan, Jhilam; Bhattacharya, C.; Kundu, S.; Meena, J. K.; Mukherjee, G.; Pandey, R.; Rana, T. K.; Roy, P.; Roy, T.; Srivastava, V.; Bhattacharya, P.

    2015-04-01

    Constraining the excitation energy at which the nuclear shell effect washes out has important implications on the production of superheavy elements and many other fields of nuclear physics research. We report the fission fragment mass distribution in ? induced reaction on an actinide target for wide excitation range in close energy interval and show direct evidence that the nuclear shell effect washes out at excitation energy ˜40 MeV. The calculation shows that the second peak of the fission barrier also vanishes around similar excitation energy.

  12. 100 Area soil washing bench-scale test procedures

    SciTech Connect

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

    1993-03-01

    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.

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

    SciTech Connect

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

    1996-02-01

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

  14. Fine Anthracite Coal Washing Using Spirals

    SciTech Connect

    R.P. Killmeyer; P.H. Zandhuis; M.V. Ciocco; W. Weldon; T. West; D. Petrunak

    2001-05-31

    The spiral performed well in cleaning the coarse 8 x 16 mesh size fraction, as demonstrated by the Ep ranging from 0.091 to 0.177. This is in line with typical spiral performance. In addition, the presence of the coarser size fraction did not significantly affect spiral performance on the typical 16 x 100 mesh fraction, in which the Ep ranged from 0.144 to 0.250. Changes in solids concentration and flow rate did not show a clear correlation with spiral performance. However, for difficult-to-clean coals with high near-gravity material, such as this anthracite, a single-stage spiral cleaning such a wide size fraction may not be able to achieve the clean coal ash and yield specifications required. In the first place, while the performance of the spiral on the coarse 8 x 16 mesh fraction is good with regard to Ep, the cutpoints (SG50s) are high (1.87 to 1.92), which may result in a clean coal with a higher-than-desired ash content. And second, the combination of the spiral's higher overall cutpoint (1.80) with the high near-gravity anthracite results in significant misplaced material that increases the clean coal ash error. In a case such as this, one solution may be to reclean the clean coal and middlings from the first-stage spiral in a second stage spiral.

  15. Adsorption of ammonium ion by coconut shell-activated carbon from aqueous solution: kinetic, isotherm, and thermodynamic studies.

    PubMed

    Boopathy, Ramasamy; Karthikeyan, Sekar; Mandal, Asit Baran; Sekaran, Ganesan

    2013-01-01

    Ammonium ions are one of the most encountered nitrogen species in polluted water bodies. High level of ammonium ion in aqueous solution imparts unpleasant taste and odor problems, which can interfere with the life of aquatics and human population when discharged. Many chemical methods are developed and being used for removal of ammonium ion from aqueous solution. Among various techniques, adsorption was found to be the most feasible and environmentally friendly with the use of natural-activated adsorbents. Hence, in this study, coconut shell-activated carbon (CSAC) was prepared and used for the removal of ammonium ion by adsorption techniques. Ammonium chloride (analytical grade) was purchased from Merck Chemicals for adsorption studies. The CSAC was used to adsorb ammonium ions under stirring at 100 rpm, using orbital shaker in batch experiments. The concentration of ammonium ion was estimated by ammonia distillate, using a Buchi distillation unit. The influence of process parameters such as pH, temperature, and contact time was studied for adsorption of ammonium ion, and kinetic, isotherm models were validated to understand the mechanism of adsorption of ammonium ion by CSAC. Thermodynamic properties such as ?G, ?H, and ?S were determined for the ammonium adsorption, using van't Hoff equation. Further, the adsorption of ammonium ion was confirmed through instrumental analyses such as SEM, XRD, and FTIR. The optimum conditions for the effective adsorption of ammonium ion onto CSAC were found to be pH 9.0, temperature 283 K, and contact time 120 min. The experimental data was best followed by pseudosecond order equation, and the adsorption isotherm model obeyed the Freundlich isotherm. This explains the ammonium ion adsorption onto CSAC which was a multilayer adsorption with intraparticle diffusion. Negative enthalpy confirmed that this adsorption process was exothermic. The instrumental analyses confirmed the adsorption of ammonium ion onto CSAC. PMID:22562341

  16. Carbon solution and partitioning between metallic and silicate melts in a shallow magma ocean: Implications for the origin and distribution of terrestrial carbon

    NASA Astrophysics Data System (ADS)

    Dasgupta, Rajdeep; Chi, Han; Shimizu, Nobumichi; Buono, Antonio S.; Walker, David

    2013-02-01

    The origin of bulk silicate Earth carbon inventory is unknown and the fate of carbon during the early Earth differentiation and core formation is a missing link in the evolution of the terrestrial carbon cycle. Here we present high pressure (P)-temperature (T) experiments that offer new constraints upon the partitioning of carbon between metallic and silicate melt in a shallow magma ocean. Experiments were performed at 1-5 GPa, 1600-2100 °C on mixtures of synthetic or natural silicates (tholeiitic basalt/alkali basalt/komatiite/fertile peridotite) and Fe-Ni-C ± Co ± S contained in graphite or MgO capsules. All the experiments produced immiscible Fe-rich metallic and silicate melts at oxygen fugacity (fO2) between ˜IW-1.5 and IW-1.9. Carbon and hydrogen concentrations of basaltic glasses and non-glassy quenched silicate melts were determined using secondary ionization mass spectrometry (SIMS) and speciation of dissolved C-O-H volatiles in silicate glasses was studied using Raman spectroscopy. Carbon contents of metallic melts were determined using both electron microprobe and SIMS. Our experiments indicate that at core-forming, reduced conditions, carbon in deep mafic-ultramafic magmas may dissolve primarily as various hydrogenated species but the total carbon storage capacity, although is significantly higher than solubility of CO2 under similar conditions, remains low (<500 ppm). The total carbon content in our reduced melts at graphite saturation increases with increasing melt depolymerization (NBO/T), consistent with recent spectroscopic studies, and modestly with increasing hydration. Carbon behaves as a metal-loving element during core-mantle separation and our experimental DCmetal/silicate varies between ˜4750 and ?150 and increases with increasing pressure and decreases with increasing temperature and melt NBO/T. Our data suggest that if only a trace amount of carbon (˜730 ppm C) was available during early Earth differentiation, most of it was partitioned to the core (with 0.20-0.25 wt.% C) and no more than ˜10-30% of the present-day mantle carbon budget (50-200 ppm CO2) could be derived from a magma ocean residual to core formation. With equilibrium core formation removing most of the carbon initially retained in the terrestrial magma ocean, explanation of the modern bulk silicate Earth carbon inventory requires a later replenishment mechanism. Partial entrapment of metal melt in solid silicate matrix, carbon ingassing by magma ocean-atmosphere interaction, and carbon outgassing from the core aided by reaction of core metal and deeply subducted water are some of the viable mechanisms.

  17. Experiment and Optimization for Simultaneous Carbonation of Ca2+ and Mg2+ in A Two-phase System of Insoluble Diisobutylamine and Aqueous Solution

    PubMed Central

    Wang, Wenlong; Wang, Man; Liu, Xin; Wang, Peng; Xi, Zhenqian

    2015-01-01

    An optimized approach of CO2 fixation in Ca2+/Mg2+-rich aqueous solutions using insoluble amine as an enhancing medium was reported. Apparent basicity was verified to be an effective indicator for the selection and optimization of organic amine systems and finally the diisobutylamine + n-octanol system was selected to enhance the carbonation reactions of CO2 in an artificial Ca2+/Mg2+-rich solution. In our experiments, when the volume ratio of insoluble organic phase to aqueous one was 2:1 and the reaction temperature was 28?°C, 92% of Ca2+ and 80% of Mg2+ could be converted to calcium and magnesium carbonate precipitates within 5?min of reaction with the bubbling-in of CO2. The organic amine system could be regenerated by using carbide slag as the regeneration agent and could still show attractive enhancement performances after 7 rounds of carbonation-regeneration experiments. In this way, the CO2 capture and sequestration was realized within one single process, with value-added Ca/Mg carbonates being the byproducts. In view of the vast availability of Ca2+/Mg2+-rich aqueous solutions and the feasible technical coordination with desalination industry, this novel process may have a good application potential in the future. PMID:26039506

  18. Experiment and Optimization for Simultaneous Carbonation of Ca(2+) and Mg(2+) in A Two-phase System of Insoluble Diisobutylamine and Aqueous Solution.

    PubMed

    Wang, Wenlong; Wang, Man; Liu, Xin; Wang, Peng; Xi, Zhenqian

    2015-01-01

    An optimized approach of CO2 fixation in Ca(2+)/Mg(2+)-rich aqueous solutions using insoluble amine as an enhancing medium was reported. Apparent basicity was verified to be an effective indicator for the selection and optimization of organic amine systems and finally the diisobutylamine + n-octanol system was selected to enhance the carbonation reactions of CO2 in an artificial Ca(2+)/Mg(2+)-rich solution. In our experiments, when the volume ratio of insoluble organic phase to aqueous one was 2:1 and the reaction temperature was 28?°C, 92% of Ca(2+) and 80% of Mg(2+) could be converted to calcium and magnesium carbonate precipitates within 5?min of reaction with the bubbling-in of CO2. The organic amine system could be regenerated by using carbide slag as the regeneration agent and could still show attractive enhancement performances after 7 rounds of carbonation-regeneration experiments. In this way, the CO2 capture and sequestration was realized within one single process, with value-added Ca/Mg carbonates being the byproducts. In view of the vast availability of Ca(2+)/Mg(2+)-rich aqueous solutions and the feasible technical coordination with desalination industry, this novel process may have a good application potential in the future. PMID:26039506

  19. Efficacies of sodium hypochlorite and quaternary ammonium sanitizers for reduction of norovirus and selected bacteria during ware-washing operations.

    PubMed

    Feliciano, Lizanel; Li, Jianrong; Lee, Jaesung; Pascall, Melvin A

    2012-01-01

    Cross-contamination of ready-to-eat (RTE) foods with pathogens on contaminated tableware and food preparation utensils is an important factor associated with foodborne illnesses. To prevent this, restaurants and food service establishments are required to achieve a minimum microbial reduction of 5 logs from these surfaces. This study evaluated the sanitization efficacies of ware-washing protocols (manual and mechanical) used in restaurants to clean tableware items. Ceramic plates, drinking glasses and stainless steel forks were used as the food contact surfaces. These were contaminated with cream cheese and reduced-fat milk inoculated with murine norovirus (MNV-1), Escherichia coli K-12 and Listeria innocua. The sanitizing solutions tested were sodium hypochlorite (chlorine), quaternary ammonium (QAC) and tap water (control). During the study, the survivability and response to the experimental conditions of the bacterial species was compared with that of MNV-1. The results showed that current ware-washing protocols used to remove bacteria from tableware items were not sufficient to achieve a 5 log reduction in MNV-1 titer. After washing, a maximum of 3 log reduction in the virus were obtained. It was concluded that MNV-1 appeared to be more resistant to both the washing process and the sanitizers when compared with E. coli K-12 and L. innocua. PMID:23227163

  20. Remediation of oil-based drill cuttings through a biosurfactant-based washing followed by a biodegradation treatment.

    PubMed

    Yan, Ping; Lu, Mang; Guan, Yueming; Zhang, Weimu; Zhang, Zhongzhi

    2011-11-01

    In this study, oil-based drill cuttings were washed by a rhamnolipid solution and then subjected to bioremediation in stainless steel boxes using sawdust as bulking agent. A mixed bacterial culture, mainly containing Pseudomonas, Acinetobacter, Alcaligenes, Agrobacterium, and Comamonas, was used as inoculums. Approximately 83% of organics were removed after washing under optimal conditions (liquid/solid ratio, 3:1; washing time, 20 min; stirring speed, 200 rpm; rhamnolipid concentration, 360 mg/L; temperature, 60 °C), and the total petroleum hydrocarbon concentration of the cuttings dropped from 85,000 to 12,600 mg/kg. In the bioremediation stage, concentrations of saturated and aromatic hydrocarbons decreased to 2140 and 1290 mg/kg, respectively, after 120 days. Ultrahigh-resolution mass spectrometry demonstrated that oxygen- and nitrogen-containing compounds had undergone biodegradation. The results of this study indicate that this two-stage remedial system can reduce treatment time and increase treatment efficiency as compared with a single bioremediation or washing treatment. PMID:21925873