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1

Plutonium recovery from carbonate wash solutions  

SciTech Connect

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

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

1991-12-31

2

Solvent wash solution  

DOEpatents

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

Neace, J.C.

1984-03-13

3

7 CFR 3201.51 - Parts wash solutions.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Parts wash solutions. 3201.51 Section 3201.51 Agriculture...Designated Items § 3201.51 Parts wash solutions. (a) Definition. Products...preference for qualifying biobased parts wash solutions. By that date, Federal agencies...

2013-01-01

4

Recovery of plutonium from solvent wash solutions  

SciTech Connect

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

Kyser, E.A.

1992-03-31

5

Laboratory and Field Soil Washing Experiments with Surfactant Solutions  

Microsoft Academic Search

During the last six years, surfactant solutions have been developed to dissolve or mobilize different NAPL types. These solutions\\u000a were made with anionic surfactants and alcohols, as well as solvents in some cases. Laboratory and field tests were performed\\u000a using these solutions to recover residual NAPL in sediments and etched-glass micromodels. Surfactant washing experiments were\\u000a done on: (1) small sand

Richard Martel; Pierre J. Gelinas; René Lefebvre; Alain Hébert; Stefan Foy; Laurent Saumure; Annie Roy; Nathalie Roy

6

Comparison of microbial contamination of enteral feeding solution between repeated use of administration sets after washing with water and after washing followed by disinfection  

Microsoft Academic Search

We compared microbial contamination of in-use enteral feeding solution from repeatedly used administration sets (a delivery bag and an infusion tube) after washing with water or washing followed by disinfection. In eight hospitals where administration sets were re-used after washing with water, residual solution was collected from both the delivery bag and the distal end of the infusion tube immediately

S. Oie; A. Kamiya

2001-01-01

7

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

Microsoft Academic Search

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

Richard Martel; René Lefebvre; Pierre J Gélinas

1998-01-01

8

[Rejuvenation of autologous blood preserved by washing in glucose- adenine- phosphate- and citrate-containing solution].  

PubMed

Outdated red cell concentrates (RCC-SAGM) were washed with a chloride-free, glucose-adenine-phosphate-citrate preservation solution. After resuspension of the red cells in this solution a hypothermic storage for additional 63 days was performed. Quality parameters (2,3-DPG, glucose, lactose, free hemoglobin, pH, chloride, pO50, shape quality index, filtration index) of the preserved red blood cells became normal within 7-11 days after the rejuvenation procedure. The data prove that a rejuvenation of outdated blood by a simple washing procedure allows a post-storage time of 21 days. PMID:9480151

Matthes, G; Richter, E; Tofoté, U; Pawlow, I; Kucera, W; Lerche, D

1994-01-01

9

Comparison of soil washing using conventional surfactant solutions and colloidal gas aphron suspensions  

SciTech Connect

Surfactants have proven to be an effective way of augmenting the removal and mobilization of organics from contaminated soil. A more recent and innovative technology to aid the removal of contaminants from soil is the use of colloidal gas aphron (CGA) suspensions. The performance of CGAs and surfactant solutions in washing soils contaminated with 2,4-dichlorophenoxy acetic acid (2,4-D) was investigated and compared with the process of washing soils with aqueous solutions of surfactants as in conventional surfactant flushing. In general it was observed that there was no significant difference in the performance of the two processes of soil washing for a highly soluble compound like 2,4-D. However, the surfactant consumption per gram of 2,4-D recovered from the soil was higher for conventional washing than for CGA solutions. CGAs also had a significant advantage over surfactant solutions in that at low flow rates, the pumping of CGAs showed lower pressure drops across the soil column.

Roy, D.; Valsaraj, K.T.; Tamayo, A. (Louisiana State Univ., Baton Rouge (United States))

1992-10-01

10

Reduced greasiness of ‘Granny Smith’ apples washed in Tween 20 solution  

Microsoft Academic Search

‘Granny Smith’ apples (Malus domestica Borkh.) tend to develop greasy skins after extended storage which makes them slippery to touch and reduces their aesthetic appeal. Washing fruit in 0.15% (w\\/w) Tween 20 surfactant solution reduced greasiness, loss of greenness, and firmness after 22 days at 20°C. These effects were associated with decreased skin permeance to gases, depressed internal oxygen (O2)

B. K. Dadzie; N. H. Banks; E. W. Hewett; D. J. Cleland

1995-01-01

11

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...

12

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

PubMed Central

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

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

2012-01-01

13

Enhanced inactivation of Salmonella and Pseudomonas biofilms on stainless steel by use of T-128, a fresh-produce washing aid, in chlorinated wash solutions.  

PubMed

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

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

2012-06-29

14

Wash-out of the non-heart-beating donor liver: a matter of flush solution and temperature?  

Microsoft Academic Search

Background and Aims: Ischemically damaged donor livers are prone to graft non-function. This can in part be explained by a suboptimal wash-out during procurement. An enriched machine perfusion (MP) preservation solution for livers, named Polysol, was developed. The aim of this study was to investigate the type of flush solution, temperature and anticoagulant content on the wash-out of the non-heart-beating

Maud Bessems; Benedict M. Doorschodt; Peter S. Albers; Alfred J. Meijer; Gulik van T. M

2006-01-01

15

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

PubMed

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

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

2013-06-01

16

Using electrocoagulation for metal and chelant separation from washing solution after EDTA leaching of Pb, Zn and Cd contaminated soil.  

PubMed

Electrocoagulation with an Al sacrificial anode was tested for the separation of chelant and heavy metals from a washing solution obtained after leaching Pb (3200 mg kg(-1)), Zn (1100 mg kg(-1)), and Cd (21 mg kg(-1)) contaminated soil with EDTA. In the electrochemical process, the sacrificial anode corroded to release Al(3+) which served as coagulant for precipitation of chelant and metals. A constant current density of 16-128 mAc m(-2) applied between the Al anode and the stainless-steel cathode removed up to 95% Pb, 68% Zn and 66% Cd from the soil washing solution. Approximately half of the initial EDTA remained in the washing solution after treatment, up to 16.3% of the EDTA was adsorbed on Al coagulant and precipitated, the rest of the EDTA was degraded by anodic oxidation. In a separate laboratory-scale remediation experiment, we leached a soil with 40 mmol EDTA per kg of soil and reused the washing solution (after electrocoagulation) in a closed loop. It removed 53% of Pb, 26% of Zn and 52% of Cd from the soil. The discharge solution was clear and colourless, with pH 7.52 and 170 mg L(-1) Pb, 50 mg L(-1) Zn, 1.5 mg L(-1) Cd and 11 mM EDTA. PMID:19828243

Pociecha, Maja; Lestan, Domen

2009-09-25

17

Removal of Pb from sewage sludge by electrokinetics: Effect of pH and washing solution type  

Microsoft Academic Search

In this study, the effect of pH and washing solution on the removal of lead from sewage sludge by electrokinetics was investigated. The six experimental runs were carried out at two different pH values – 3 and 4 – using acetic acid, nitric acid and phosphoric acid. In addition, the sequential chemical extraction scheme according to the BCR’s (Community Bureau

Özge Hanay; Halil Hasar; Nilufer Nacar Koçer; Ozgur Ozdemir

2009-01-01

18

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

PubMed Central

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

Yeung, Norine W; Hayes, Kenneth A

2013-01-01

19

Efficacy of a lactic acid\\/sodium benzoate wash solution in reducing bacterial contamination of raw chicken  

Microsoft Academic Search

Raw chicken wings inoculated with Salmonella, Campylobacter jejuni, Listeria monocytogenes, Staphylococcus aureus, or Escherichia coli O157:H7 were washed in water (control) or a solution of a 0.5% lactic acid\\/0.05% sodium benzoate (LB) (pH 2.64) for 30 min. Viable cells of pathogenic bacteria and naturally occurring psychrotrophic bacteria on wings were enumerated after 0, 2, 4, 6, and 8 days of

Cheng-an Hwang; Larry R. Beuchat

1995-01-01

20

Spray Washing Carcasses with Alkaline Solutions of Lauric Acid to Reduce Bacterial Contamination  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

21

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...

22

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

PubMed

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

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

2013-10-04

23

Effect of Nitrite/Nitrate concentrations on Corrosivity of Washed Precipitate  

SciTech Connect

Cyclic polarization scans were performed using A-537 carbon steel in simulated washed precipitate solutions of various nitrite and nitrate concentrations. The results of this study indicate that nitrate is an aggressive anion in washed precipitate. Furthermore, a quantitative linear log-log relationship between the minimum effective nitrite concentration and the nitrate concentration was established for washed precipitate with other ions at their average compositions.

Congdon, J.W.

2001-03-28

24

Carbon dioxide absorption in glucosamine aqueous solutions  

Microsoft Academic Search

The present paper includes studies related to gas\\/liquid mass transfer process of carbon dioxide in aqueous solutions of glucose and glucosamine. These studies have been carried out employing a cylindrical bubble column, where the gas phase was fed through an only orifice. The absorption process has been characterized taken into account the influence of gas flow-rate and the liquid phase

D. Gómez-Díaz; J. M. Navaza; B. Sanjurjo; L. Vázquez-Orgeira

2006-01-01

25

CATALYZED OXIDATION OF URANIUM IN CARBONATE SOLUTIONS  

DOEpatents

A process is given wherein carbonate solutions are employed to leach uranium from ores and the like containing lower valent uranium species by utilizing catalytic amounts of copper in the presence of ammonia therein and simultaneously supplying an oxidizing agent thereto. The catalysis accelerates rate of dissolution and increases recovery of uranium from the ore. (AEC)

Clifford, W.E.

1962-05-29

26

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

NASA Astrophysics Data System (ADS)

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

Nipper, J.; Bowden, W. B.

2009-12-01

27

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

Microsoft Academic Search

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

Kurnia Ramadhan; Nurul Huda; Ruzita Ahmad

28

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

PubMed

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

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

2012-05-29

29

Nonequilibrium dynamic modeling of carbon dioxide absorption by partially carbonated ammonia solutions  

Microsoft Academic Search

In this research, a nonequilibrium dynamic stage model has been developed for reactive absorption of carbon dioxide by carbonated ammonia solutions. The model considers mass transfer between gas and liquid phases in both directions employing dynamic film model theory. Experimental data of carbon dioxide reactive absorption by partially carbonated ammonia solution has been used to validate the model. The data

Ahad Ghaemi; Shahrokh Shahhosseini; Mohammad Ghanadi Maragheh

2009-01-01

30

SITE TECHNOLOGY CAPSULE: BIOGENESIS SOIL WASHING TECHNOLOGY  

EPA Science Inventory

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

31

Dissolution of spent nuclear fuel in carbonate–peroxide solution  

Microsoft Academic Search

This study shows that spent UO2 fuel can be completely dissolved in a room temperature carbonate–peroxide solution apparently without attacking the metallic Mo–Tc–Ru–Rh–Pd fission product phase. In parallel tests, identical samples of spent nuclear fuel were dissolved in nitric acid and in an ammonium carbonate, hydrogen peroxide solution. The resulting solutions were analyzed for strontium-90, technetium-99, cesium-137, europium-154, plutonium, and

Chuck Z. Soderquist; Brady D. Hanson

2010-01-01

32

Development of the rapid and simple elisa (whole blood-ELISA) using coconut water-tween as a wash solution for whole blood sample from Schistosoma japonicum-infected rabbit and human.  

PubMed

PBS-Tween as a wash solution, prepared with distilled water, is used in ELISA. In areas where schistosomiasis is endemic, however, distilled water is hard to come by. We have modified a WHOLE BLOOD-ELISA test to use coconut water-Tween as a wash solution, because coconut water is easy to come by and cheap in the tropics. We applied the test to whole blood samples from rabbits and humans infected with Schistosoma japonicum. This modified WHOLE BLOOD-ELISA was confirmed to be a rapid, simple, and cost-effective method. PMID:16610638

Hirose, Yoshinori; Lipayon, Ignacio L; Kirinoki, Masashi; Chigusa, Yuichi; Matsuda, Hajime

2005-11-01

33

Influence of EDTA washing on the species and mobility of heavy metals residual in soils.  

PubMed

Aiming to estimate the potential risk of ethylenediaminetetraacetic acid (EDTA)-enhanced soil washing, the heavy metal species and their mobility in the washed soil under different combinations were investigated by batch leaching tests and the sequential extraction procedure. Results demonstrate that the metal removal efficiency was rather low (less than 12%), partially due to the significant Ca dissolution and strong bonding between metals and the soil as well as the insufficient EDTA dosage. The washing combination of 0.0005 M EDTA and half-an-hour washing can enhance the instant mobility of Ni, Zn and Pb possibly owing to the slow detachment of EDTA-destabilized metals. Metal fractionation also exhibits the corresponding increase in their labile exchangeable fractions. Therefore, a more concentrated EDTA solution for a longer duration often decreased their mobility. The increase in some fractions of a curtain metal implies the redistribution of this metal during the EDTA soil washing. The pathway of such a redistribution may vary for different metals, but the redistribution to organic matter is often a slow process, while that to carbonates or Fe/Mn oxides is a faster one and even may occur in a half hour washing with 0.0005 M EDTA solution. These redistribution processes may also increase the metal chemical availability. Therefore, we should prudently control the chelating reagent concentration and washing duration to finally minimize the mobility and availability of the remaining heavy metals when designing the soil washing for the remediation of metal-contaminated soils. PMID:19748734

Zhang, Weihua; Huang, Hao; Tan, Fenfang; Wang, Hong; Qiu, Rongliang

2009-08-25

34

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

PubMed

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

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

2009-06-18

35

Basic Solutions to Carbon/Carbon Oxidation: Science and Technology.  

National Technical Information Service (NTIS)

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 temp...

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

1998-01-01

36

Thermodynamics of carbon and oxygen solutions in manganese melts  

NASA Astrophysics Data System (ADS)

The thermodynamics of carbon and oxygen solutions in manganese melts is studied. An equation for the temperature dependence of the activity coefficient of carbon in liquid manganese is obtained (?{C(Mn)/0}= -1.5966 + (1.0735 × 10-3) T). The temperature dependence of the Gibbs energy of the reaction of carbon dissolved in liquid manganese with the oxygen of manganese oxide is shown to be described by the equation ? G {T/0}= 375264 - 184.66 T(J/mol). This reaction can noticeably be developed depending on the carbon content at temperatures of 1700 1800°C. The deoxidation ability of carbon in manganese melts is shown to be much lower than that in iron and nickel melts due to the higher affinity of manganese to both oxygen and carbon. Although the deoxidation ability of carbon in manganese melts increases with temperature, the process develops at rather high carbon contents in all cases.

Dashevskii, V. Ya.

2007-12-01

37

Dissolution of Spent Nuclear Fuel in Carbonate-Peroxide Solution  

SciTech Connect

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

Soderquist, Chuck Z.; Hanson, Brady D.

2010-01-31

38

Flow of Aqueous Solutions in Carbon Nanotubes  

Microsoft Academic Search

\\u000a We conduct simulations of water flowing inside carbon nanotubes using non-equilibrium molecular dynamics simulations. A new\\u000a adaptive forcing scheme is proposed to enforce a mean center of mass velocity. This scheme is compared to the non-adaptive,\\u000a constant body\\/gravity force for the flow of methane in a carbon nanotube. The two schemes produce similar streaming velocity\\u000a profiles and practically identical slip

S. C. Kassinos; J. H. Walther; E. Kotsalis; P. Koumoutsakos

39

CORROSION OF CARBON STEEL IN WASTE SOLUTIONS CONTAINING MERCURY  

Microsoft Academic Search

The corosion behavior of A-285, A-135, A-l06, and A-53 carbon steel was ;\\u000a studied in multicomponent simulated waste solutions containing mercury. In the ;\\u000a liquid phase, the carbon steels corroded at a very low rate; mercury did not ;\\u000a increase the corrosion rate in any of the solutions tested. In the vapor phase ;\\u000a and at the vapor-liquid interface, pitting

Kranzlein

1959-01-01

40

The electrodeposited titanium powders in nonaqueous propylene carbonate solution  

Microsoft Academic Search

Titanium has many good chemical and physical properties. This study investigates the electrodeposition of titanium in nonaqueous propylene carbonate solution at low temperature though the amount of electrodeposited titanium is a little. The amount of electrodeposited titanium increases with an increase of propylene carbonate. The order of electrodeposited titanium amount was at pH 4.5>6.0>3.0 in slightly acidic solution owing to

Chin-Ming Chu

2011-01-01

41

Heterogeneity of active carbons in adsorption of phenol aqueous solutions  

Microsoft Academic Search

Energetic heterogeneity of activated carbons prepared from bituminous coals is investigated on the basis of adsorption isotherms of phenol from the dilute aqueous solutions. The Langmuir–Freundlich (L–F) equation has been used to estimate the monolayer capacity values of carbons studied. Adsorption energy distribution functions have been calculated by using algorithm INTEG based on a regularization method. Analysis of these functions

P. Podkoscielny; A. D; O. V. Marijuk

2003-01-01

42

Effects of mineral loading methods on carbon solution reaction of coal-derived carbon material  

Microsoft Academic Search

11 oxides (MgO, CaO, BaO, TiO2, V2O5, MnO2, Fe2O3, CuO, ZnO, PbO2 and B2O3), often found in coal-derived carbon materials, were loaded into the coal-derived carbon material by two methods such as adsorbing oxides through solution onto the surface of coke and adding oxides into the coal before carbonization. The effects of oxides on carbon solution reaction of carbon material

Jun-he YANG; Xia WANG; Shu-hui CHENG; Xiao-rong LIU; Yong-zheng FANG

2006-01-01

43

Effect of inhibitors on corrosion rate of carbon steels in CO 2 -saturated potassium carbonate solutions  

Microsoft Academic Search

St3 carbon steel [low-carbon steel] manifests corosion resistance under conditions of treating hydrogen-rich gas with potassium carbonate to remove C02 [I]. However, because of the high velocity of the absorbent solution and the presence of suspended solid particles in the solution, equipment made of this steel is subject to local damage in the form of point corrosion, pitting, and corrosion

A. K. Nikitina; V. P. Khvatkova; V. M. Umnyashkina; L. P. Vershinina

1984-01-01

44

Electrochemical isolation of Np from circulating carbonate solutions  

SciTech Connect

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

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

1995-03-01

45

Anomalous distribution in atom map of solute carbon in steel.  

PubMed

The distribution of carbon in atom probe tomography maps was investigated in various phases of steel. Carbon atoms in 3D atom maps of martensite and cementite phases showed an almost uniform distribution. On the other hand, carbon atoms in ferrite were consistently enriched along the zone line joining the (0 0 2) and the (2 2 2) poles, and in the depth direction of analysis, which was different from the actual distribution. The width and concentration of the enriched regions remained unchanged at a specimen temperature ranging from 90 to 30K. Moreover, the ratio of molecular carbon ions to total carbon ions decreased with decreasing temperature, but did not change between the enriched and diluted regions. Based on the results, the reason for the anomalous distribution of solute carbon atoms in atom maps is discussed. PMID:21292398

Kobayashi, Y; Takahashi, J; Kawakami, K

2011-01-18

46

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

Microsoft Academic Search

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

F. J. Carrión Fité

1992-01-01

47

Kinetic study of platinum sorption from solutions by active carbons  

SciTech Connect

The purpose of this work was to study the kinetics of sorption of platinum compounds from hydrochloric acid solutions by active carbons, to identify the controlling step of mass transfer during sorption, and to formulate a mathematical model of the kinetics of the given process. Experimental study of the kinetics of sorption of (PtCl/sub 6/)/sup 2 -/ anions from hydrochloric acid solutions by SKS-3 and SKN-2M artificial active carbons showed that the controlling step is mass transfer by internal diffusion.

Bagreev, A.A.; Tarasenko, Yu.A.; Mardanenko, V.K.; Potyazhenko, I.A.

1988-07-20

48

Adsorption of selected herbicides from aqueous solutions on activated carbon  

Microsoft Academic Search

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

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

2010-01-01

49

Reactions of lime with carbonate-containing solutions  

Microsoft Academic Search

In the Bayer process for refining alumina, lime (either quicklime or slaked lime) is added to the process liquor to precipitate calcium carbonate and restore alkalinity to the solution. The work described in this paper was undertaken to elucidate the mechanism of this precipitation reaction about which surprisingly little is known. In the first part of the study, the composition

B.-A Xu; D. E Giles; I. M Ritchie

1998-01-01

50

Effect of temperature on carbon dioxide absorption in monoethanolamine solutions  

Microsoft Academic Search

The effect of temperature on volumetric mass transfer coefficient was studied during the absorption process of carbon dioxide in monoethanolamine aqueous solutions, using a square bubble column. Our studies provide an empirical correlation type Boltzmann to estimate the temperature operated, at different amine concentrations and gas flow rates. An excellent agreement has been shown between predicted and experimental data (r2>0.991).

Rocío Maceiras; Estrella Álvarez; M. Ángeles Cancela

2008-01-01

51

Wash This Way  

NSDL National Science Digital Library

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

Society, American C.

2011-01-01

52

Viability and functional integrity of washed platelets  

SciTech Connect

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

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

1989-07-01

53

The surface chemistry of lithium electrodes in alkyl carbonate solutions  

SciTech Connect

The chemical composition of the surface films formed on lithium in alkyl carbonate solutions was explored using surface sensitive Fourier transform infrared spectroscopy (external reflectance mode). The solvents included propylene carbonate, ethylene carbonate, and dimethyl carbonate. The salts included LiAsF{sub 6}, LiClO{sub 4}, LiBF{sub 4}, and LiPF{sub 6}. The advantages of this work over previous studies are that highly reflective Li surfaces were prepared fresh in solution and that the aging processes of the surface films initially formed could be rigorously investigated. Furthermore these three important solvents were investigated in a single study. This work further proves that the films initially formed on Li surfaces in these solvents consist of ROCO{sub 2}Li as the major constituents. Upon storage, the films initially formed react with trace water to form Li{sub 2}CO{sub 3}, which gradually also becomes a major surface species. It was found that these aging processes also depend on the salts used (for example ROCO{sub 2}Li or Li{sub 2}CO{sub 3} films are not stable in LiPF{sub 6} or LiBF{sub 4} solutions).

Aurbach, D.; Ein-Ely, Y.; Zaban, A. [Bar-Ilan Univ., Ramat Gan (Israel). Dept. of Chemistry

1994-01-01

54

Simultaneous leaching and carbon sequestration in constrained aqueous solutions.  

PubMed

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

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

2011-01-19

55

Soil washing enhancement with solid sorbents  

SciTech Connect

Soil washing is a dynamic, physical process that remediates contaminated soil through two mechanisms: particle size separation and transfer of the contaminant into the (mostly) liquid stream. The performance of different sorbents and additives to remove motor oil from sea sand was tested. Hydrocyclone, attrition scrubber, and froth flotation equipment were used for the decontamination study. Sorbents and additives were mixed with soils in the attrition scrubber prior to flotation. Sorbents used were granular activated carbon, powder activated carbon, and rubber tires. Chemical additives used were calcium hydroxide, sodium carbonate, Alconox{reg_sign}, Triton{reg_sign} X-100 and Triton{reg_sign} X-114. When a froth flotation run was performed using no additive, washed soils {open_quotes}tails{close_quotes} contained 4000 ppm of total oil and grease (TOG). However, when carbon or rubber (6% by weight) was added to the contaminated soils the washed soils {open_quotes}tails{close_quotes} contained 4000 ppm of total oil and grease (TOG). The addition of sodium carbonate or calcium hydroxide (6% by weight) had same effects as sorbents. In both cases washed soil {open_quotes}tails{close_quotes} contained total oil and grease of less than 1000 ppm. The use of these non-hazardous additives or sorbent can enhance the soil washing process and consequently saves on time (residence time in equipment design) required to achieve the target clean up levels. 18 refs., 12 figs.

El-Shoubary, Y.M. [Merck & Co., Somerset, NJ (United States); Woodmansee, D.E. [GE Corporate Research & Development, Schenectady, NY (United States)

1996-12-31

56

Magnetic-field-enhanced carbon solution in proeutectoid ferrite  

NASA Astrophysics Data System (ADS)

Modification of phase solubility of Fe–C system by magnetic field has been recognized by thermodynamic calculations and indirectly by microstructural examinations. However, there has been no direct experimental verification and the underlying physical mechanism is not fully uncovered. In this work, the enhanced carbon content in proeutectoid ferrite under a 12 T magnetic field is evidenced through wavelength-dispersive spectroscopy using a Shimadzu 1610 electron probe microanalyser measurements. The magnetic-field-enhanced carbon solution reduces the demagnetization energy of the system and makes it energetically more stable.

Zhang, X. X.; Xu, N.; Wang, S. J.; Zhang, Y. D.; Raulot, J.-M.; Esling, C.; Zhao, X.; Zuo, L.

2013-09-01

57

Laundry: Washing Infected Material  

MedlinePLUS

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

58

Methylene Blue adsorption from aqueous solution by activated carbon: Effect of acidic and alkaline solution treatments  

Microsoft Academic Search

The removal of Methylene Blue (MB) from aqueous solution using activated carbon (AC) has been investigated. Adsorption experiments were conducted and the maximum adsorption capacity was determined. The effect of experimental parameters such as pH, dye concentration and temperature were studied on the adsorption process. Equilibrium data were mathematically modeled using the Langmuir and Freundlich adsorption models to describe the

Christianah O. Ijagbemi; Ji I. Chun; Da. H. Han; Hye Y. Cho; Se J. O; Dong S. Kim

2010-01-01

59

Simultaneous leaching and carbon sequestration in constrained aqueous solutions  

Microsoft Academic Search

The behavior of metal ions’ leaching and precipitated mineral phases of metal-rich fly ash (FA) was examined in order to evaluate\\u000a microbial impacts on carbon sequestration and metal immobilization. The leaching solutions consisted of aerobic deionized\\u000a water (DW) and artificial eutrophic water (AEW) that was anaerobic, organic- and mineral-rich, and higher salinity as is typical\\u000a of bottom water in eutrophic

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

2011-01-01

60

Hydrogen and carbon in solid solution in oxides and silicates  

Microsoft Academic Search

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

Friedemann Freund

1987-01-01

61

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

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

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

62

Washed Cotton: Washing Techniques, Processing Characteristics, and Health Effects.  

National Technical Information Service (NTIS)

The collection of papers described washing cotton to remove potential health effects, the evaluation of acute human airway toxicity of standard and washed cotton dusts, microbiology of the fiber and airborne dust from washed cotton, differentiation of was...

P. J. Wakelyn R. R. Jacobs I. W. Kirk

1986-01-01

63

Adsorption of cadmium from aqueous solutions on sulfurized activated carbon prepared from nut shells  

Microsoft Academic Search

Low-cost activated carbon, derived from nut shells, and its modified sample have been used as replacements for the current expensive methods of removing cadmium from aqueous solutions and waste waters. Adsorption of cadmium onto four kinds of activated carbons has been studied; prepared activated carbon (PAC), commercial activated carbon (CAC), and the sulfurized ones (SPAC & SCAC). The activated carbon

Amir Fouladi Tajar; Tahereh Kaghazchi; Mansooreh Soleimani

2009-01-01

64

Fluidic delivery of homogeneous solutions through carbon tube bundles  

NASA Astrophysics Data System (ADS)

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

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

2009-07-01

65

Fluidic delivery of homogeneous solutions through carbon tube bundles.  

PubMed

A wide array of technological applications requires localized high-rate delivery of dissolved compounds (in particular, biological ones), which can be achieved by forcing the solutions or suspensions of such compounds through nano or microtubes and their bundled assemblies. Using a water-soluble compound, the fluorescent dye Rhodamine 610 chloride, frequently used as a model drug release compound, it is shown that deposit buildup on the inner walls of the delivery channels and its adverse consequences pose a severe challenge to implementing pressure-driven long-term fluidic delivery through nano and microcapillaries, even in the case of such homogeneous solutions. Pressure-driven delivery (3-6 bar) of homogeneous dye solutions through macroscopically-long (approximately 1 cm) carbon nano and microtubes with inner diameters in the range 100 nm-1 microm and their bundled parallel assemblies is studied experimentally and theoretically. It is shown that the flow delivery gradually shifts from fast convection-dominated (unobstructed) to slow jammed convection, and ultimately to diffusion-limited transport through a porous deposit. The jamming/clogging phenomena appear to be rather generic: they were observed in a wide concentration range for two fluorescent dyes in carbon nano and microtubes, as well as in comparable transparent glass microcapillaries. The aim of the present work is to study the physics of jamming, rather than the chemical reasons for the affinity of dye molecules to the tube walls. PMID:19531856

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

2009-06-17

66

Interactions of functionalized carbon nanotubes with tethered pyrenes in solution  

NASA Astrophysics Data System (ADS)

Single-wall carbon nanotubes (SWNTs) were functionalized by oligomeric species containing derivatized pyrenes. Absorption and emission properties of the pyrene moieties tethered to the functionalized SWNTs were studied in homogeneous solution. The absorption spectra suggest no significant ground-state complexation between the pyrenes and nanotubes. The fluorescence and fluorescence excitation results show that the tethered pyrenes form "intramolecular" (intra-nanotube) excimers and that the excimer formation is predominantly dynamic in nature. The time-resolved fluorescence results show that the pyrene monomer and excimer emissions are significantly quenched by the attached SWNTs. The quenching is explained in terms of a mechanism in which carbon nanotubes serve as acceptors for excited-state energy transfers from the tethered pyrene moieties.

Qu, Liangwei; Martin, Robert B.; Huang, Weijie; Fu, Kefu; Zweifel, Daniel; Lin, Yi; Sun, Ya-Ping; Bunker, Christopher E.; Harruff, Barbara A.; Gord, James R.; Allard, Lawrence F.

2002-11-01

67

TANK 7 CHARACTERIZATION AND WASHING STUDIES  

SciTech Connect

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

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

2010-02-04

68

Spectrophotofluorometric determination of terbium and europium in potassium carbonate solution.  

PubMed

The conditions for the spectrophotofluorometric determination of terbium and europium, in solutions of potassium carbonate, have been established. The apparent excitation and fluorescence wavelengths used, respectively, are 245 mmu and 550 mmu for terbium and 400 mmu and 620 mmu for europium. The fluorescence varies linearly with the concentration of terbium and europium in the range 0.3-70 mug, of terbium/ml and 4-800 mug of europium/ml. Large amounts of gadolinium, lutetium and yttrium do not interfere. Cerium(IV) interferes seriously. PMID:18959977

Taketatsu, T; Carey, M A; Banks, C V

1966-08-01

69

Probing Chemical Potentials in Solution with Carbon Nanotube Transistors  

NASA Astrophysics Data System (ADS)

We have used single-walled carbon nanotube transistors to sense redox-active transition metal complexes in a conducting liquid environment. The molecules shift the gate voltage dependence of the nanotube conductance. This shift depends logarithmically on the ratio of oxidized to reduced molecules, which is changed and measured using traditional electrochemical methods. We attribute this signal primarily to the changing electrostatic potential of the solution as set by the water-gate wire, and not to a local interaction between the molecules and the nanotube.

Larrimore, Lisa; Nad, Suddhasattwa; Zhou, Xinjian; Abruña, Héctor; McEuen, Paul

2006-03-01

70

Electrochemical behavior of carbon steel in carbon dioxide-saturated diglycolamine solutions  

SciTech Connect

The electrochemical behavior of carbon steel in diglycolamine (DGA) solutions saturated with carbon dioxide (CO{sub 2}) under 4.5 MPa pressure was investigated using potentiodynamic polarization and impedance measurements at room temperature (RT) and at 100 C. Electrode equivalent circuits were proposed for interpreting the impedance measured at the higher temperature. Anodic and cathodic reaction mechanisms depended upon DGA concentration, temperature, and potential. At RT, the rate-determining step of the cathodic reduction changed from a diffusion process to an interfacial reaction with increasing DGA concentration. Corrosion rates were relatively low, and varied only slightly with DGA concentration. At 100 C, a tight corrosion product film was formed on the carbon steel surface in 0.1 M and 1.0 M DGA solutions. Anodic dissolution was inhibited strongly by slow ion diffusion in the film, and corrosion rates were much lower than those at RT. The tight corrosion product film did not form in the 5.0 M DGA solution, and the corrosion rate was very high. There were differences in the anodic dissolution mechanisms between the low- and high-concentration DGA solutions. At the high DGA concentration and at 100 C, a surface adsorption and an interfacial intermediate electrochemical reaction played important roles in cathodic reduction and anodic dissolution, respectively.

Guo, X.P.; Tomoe, Y. [Teikoku Oil Co., Tokyo (Japan). Technical Research Center

1998-11-01

71

Insights into non-Fickian solute transport in carbonates  

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

72

Ultrafast carbon-carbon single-bond rotational isomerization in room-temperature solution.  

PubMed

Generally, rotational isomerization about the carbon-carbon single bond in simple ethane derivatives in room-temperature solution under thermal equilibrium conditions has been too fast to measure. We achieved this goal using two-dimensional infrared vibrational echo spectroscopy to observe isomerization between the gauche and trans conformations of an ethane derivative, 1-fluoro-2-isocyanato-ethane (1), in a CCl4 solution at room temperature. The isomerization time constant is 43 picoseconds (ps, 10(-12) s). Based on this value and on density functional theory calculations of the barrier heights of 1, n-butane, and ethane, the time constants for n-butane and ethane internal rotation under the same conditions are approximately 40 and approximately 12 ps, respectively. PMID:17008529

Zheng, Junrong; Kwak, Kyungwon; Xie, Jia; Fayer, M D

2006-09-29

73

Ultrafast Carbon-Carbon Single-Bond Rotational Isomerization in Room-Temperature Solution  

NASA Astrophysics Data System (ADS)

Generally, rotational isomerization about the carbon-carbon single bond in simple ethane derivatives in room-temperature solution under thermal equilibrium conditions has been too fast to measure. We achieved this goal using two-dimensional infrared vibrational echo spectroscopy to observe isomerization between the gauche and trans conformations of an ethane derivative, 1-fluoro-2-isocyanato-ethane (1), in a CCl4 solution at room temperature. The isomerization time constant is 43 picoseconds (ps, 10-12 s). Based on this value and on density functional theory calculations of the barrier heights of 1, n-butane, and ethane, the time constants for n-butane and ethane internal rotation under the same conditions are ~40 and ~12 ps, respectively.

Zheng, Junrong; Kwak, Kyungwon; Xie, Jia; Fayer, M. D.

2006-09-01

74

Method of producing UO2 wherein methanol wash is provided  

SciTech Connect

In the production of UO2, ammonium uranyl carbonate is an intermediate product wet with water and contaminated with ammonium carbonate and is washed with methanol to remove water and ammonium carbonate. The spent methanol containing 50% water and up to 10% ammonium carbonate is subjected to rectification in a column under subatmospheric pressure with cooling the top of the tower to a low temperature to retard decomposition of ammonium carbonate and condense a liquid water fraction. Clogging of the column, vapor lines and condenser by recombination of the decomposition products is prevented. The purified methanol contains less than 5% water and may be returned for further washing of ammonium uranyl carbonate.

Sondermann, T.

1981-03-24

75

The passivity of 304 stainless steel in propylene carbonate solutions  

SciTech Connect

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.

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

76

Carbon dioxide capture capacity of sodium hydroxide aqueous solution.  

PubMed

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

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

2012-11-24

77

Soil washing treatability study  

SciTech Connect

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

Krstich, M.

1995-12-01

78

Lead removal via soil washing and leaching  

NASA Astrophysics Data System (ADS)

A soil washing and leaching process was tested for removing lead from soils. A soil-washing circuit, including size and gravity separations, was employed to remove the coarse metallic lead particles, while the leaching was applied to remove fine metallic lead particles and other lead species. The soil-washing tests proved that the metallic lead particles larger than 0.15 mm (100 mesh) could be effectively removed. The sodium-chloride-based leaching solution with ferric chloride or sodium hypochlorite as oxidants was adopted in the leaching. The leaching experimental results indicated that under the pH of 2 and Eh of 1,300 mV, the metallic lead particles smaller than 0.15 mm and other lead species can be dissolved in the leaching solution within 60 minutes.

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

2001-12-01

79

Heterogeneity of activated carbons in adsorption of aniline from aqueous solutions  

Microsoft Academic Search

The heterogeneity of activated carbons (ACs) prepared from different precursors is investigated on the basis of adsorption isotherms of aniline from dilute aqueous solutions at various pH values. The APET carbon prepared from polyethyleneterephthalate (PET), as well as, commercial ACP carbon prepared from peat were used. Besides, to investigate the influence of carbon surface chemistry, the adsorption was studied on

P. Podkoscielny; K. László

2007-01-01

80

Prediction of adsorption from multicomponent solutions by activated carbon using single-solute parameters  

Microsoft Academic Search

The adsorption of 3 barbiturates—phenobarbital, mephobarbital, and primidone—from simulated intestinal fluid (SIF), without\\u000a pancreatin, by activated carbon was studied using the rotating bottle method. The concentrations of each drug remaining in\\u000a solution at equilibrium were determined with the aid of a high-performance liquid chromatography (HPLC) system employing a\\u000a reversed-phase column. The competitive Langmuir-like model, the modified competitive Langmuir-like model, and

Dale Eric Wurster; Khouloud A. Alkhamis; Lloyd E. Matheson

2000-01-01

81

THE NATURE OF EUROPIUM ION IN CARBONATE SOLUTION AND POLAROGRAPHIC DETERMINATION OF MICRO AMOUNTS OF EUROPIUM  

Microsoft Academic Search

The nature of the complex europium carbonate ion in concentrated ; carbonate solution was studied polarographically. A polarographic method for the ; determination of micro amounts of europium ion in the presence of diverse ions ; (and especially lanthanides) was developed. (auth);

Seizo Misumi; Yoshitaka Masuda

1963-01-01

82

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

PubMed

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

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

2013-08-07

83

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

84

Uranium (VI) sorption by multiwalled carbon nanotubes from aqueous solution  

NASA Astrophysics Data System (ADS)

Sorption of uranium (VI) from aqueous solutions onto Multiwalled Carbon Nanotubes (MWCNTs) has been studied under varying experimental conditions of initial uranium concentration, contact time, pH, and temperature, to assess the kinetic and equilibrium parameters. The optimum pH for sorption of uranium (VI) onto MWCNTs was 5. The kinetic data were fitted with pseudo-first-order, pseudo-second-order, and intra-particle diffusion models. The sorption process was well described by pseudo-second-order kinetics. The uranium sorption data were fitted by the Langmuir, Freundlich, and Dubinin-Radushkevich equilibrium models to obtain the characteristic parameters of each model. The Langmuir isotherm was found to best represent the measured sorption data. According to the evaluation using the Langmuir model, the maximum sorption capacity of uranium (VI) ions onto MWCNTs increased with temperature, from 24.9 to 39.1 mg g-1 when the temperature was increased from 298 to 318 K. The calculated sorption thermodynamic parameters including ?G°, ?H°, and ?S° indicated the spontaneous nature of uranium sorption onto MWCNTs. The results suggest that MWCNTs are suitable materials for preconcentration and solidification of uranium (VI) species from aqueous solutions.

Fasfous, Ismail I.; Dawoud, Jamal N.

2012-10-01

85

Wheat Evolution: Dough Washing  

NSDL National Science Digital Library

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

Council, Biotechnology A.

2012-01-01

86

Multi-walled carbon nanotubes fabricated by electrospinning of acrylonitrile/nylon solution and subsequent carbonization.  

PubMed

The poly(acrylonitrile) (PAN) nanofiber web interpenetrated nylon-6 nanofiber supporters were prepared by electrospinning of an acrylonitrile (AN)/nylon-6 solution. It was realized that the average diameters of PAN and nylon-6 nanofiber were 20 and 100 nm, respectively, and that the PAN nanofibers constructed spider-mat networks which were supported by the robust nylon-6 nanofiber pillars. After stabilization and carbonization above 600 degrees C, both hollow-shaped and bamboo-shaped multi-walled carbon nanotubes (MWCNTs) were formed with the diameter range from 5 to 20 nm. The morphology and structure of MWCNTs had been further investigated by the combination techniques of transmission electron microscopy (TEM), electron diffraction (ED), X-ray diffraction (XRD) and elemental analyzer (EA). PMID:21125878

Park, Soo-Jin; Parajuli, Daman Chandra; Bajagi, Madhab Prasad; Jeong, Kwang-Un; Barakat, Nasser Aly Mohamed; Kim, Hak Yong

2010-08-01

87

Method of timing hand washing  

US Patent & Trademark Office Database

A hand washing device and method encouraging hand washing includes a display panel, a message "WASH UP with Soap and Water. Get rid of germs in only 15 seconds." and may have one of a variety of timing means to time the wash cycle or the user may use an ordinary clock. Germ illustrations indicate consequences. The panel is on personal and public use soap dispensers and return springs are used as the timing device.

2007-12-25

88

Enzymes for low temperature washing  

Microsoft Academic Search

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

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

1981-01-01

89

The regeneration of polluted activated carbon by radiation techniques  

NASA Astrophysics Data System (ADS)

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

Minghong, W.; Borong, B.; Ruimin, Z.; Jinliang, Z.; Longxin, H.

1998-10-01

90

Adsorption of Mercuric Ion from Aqueous Solutions Using Activated Carbon  

Microsoft Academic Search

Activated carbon (AC) was prepared from hazelnut shells using two steps of carbonization followed by steam activation. Methylene blue dye was used as a probe for evaluation of the prepared activated carbon. In order to have a better comparison, a commercial grade of activated carbon (powdered) obtained from the Merck Company has also been used in this research as standard.

R. Ansari Khalkhali; R. Omidvari

91

Polyelectrolyte and carbon nanotube multilayers made from ionic liquid solutions  

NASA Astrophysics Data System (ADS)

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

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

2010-10-01

92

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

SciTech Connect

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

Bannerjee, P.

1993-09-02

93

Leaching kinetics of malachite in ammonium carbonate solutions  

NASA Astrophysics Data System (ADS)

Leaching of malachite was conducted with ammonium carbonate as lixiviant and with temperature, lixiviant concentration, and particle size as variables. Two stages of reaction were found. In Stage I, the initial dissolution of malachite proceeds rapidly, but after about 10 pct reaction the rate is reduced by surface blockage due to the presence of a needle-structured intermediate, presumably Cu(OH)2. Subsequently, malachite and the intermediate dissolve concurrently. In Stage II, after 90 pct reaction, essentially all of the malachite has dissolved and only the intermediate remains. It dissolves in Stage II. The activation energy is 64 kJ/mole (15.3 kcal/mole) for Stage I and 75 kJ/mole (18 kcal/mole) for Stage II. The rate of reaction in Stage I is proportional to the reciprocal of particle size and is 0.8 order with respect to the concentration of ammonium carbonate. The structures of leaching residues were studied using a scanning electron microscope. The kinetic data (activation energy and entropy), particle size and concentration dependence, residue morphology, and general leaching behavior evident from microscopic monitoring during leaching were used to develop the geometric equation for leaching in Stage I. The equation, based on a heterogeneous reaction with geometric rate control, is: 1 - (1 - ? 1/3 = K01/r0/[(NH4)2C03]0.8 exp(-64,000/RT)t. It was deduced that initial steps in reaction were: (1) release of Cu2+ from malachite; (2) initial complexing with ammonia to form Cu(NH3)2+; and (3) subsequent complexing to produce Cu(NH3){4/2+} which is stable in solution at pH 8.8, the buffered pH of reaction. Stage II appears to be a similar reaction except that the reaction obeys cylindrical geometry instead of spherical geometry as in Stage I.

Oudenne, Paul D.; Olson, Ferron A.

1983-03-01

94

Pressure solution in carbonate source rocks and its control on petroleum generation and migration  

Microsoft Academic Search

Based on detailed geochemical and petrographic studies of conventional cores of a Triassic age carbonate source rock formation from three well sites at increasing maturity stages, it is shown that the effects of carbonate diagenesis, especially pressure solution during relatively shallow burial stages, exercise major controls on the processes of petroleum generation and migration during deeper burial. Pressure solution leads

Rolando di Primio; Matthias Radke; Rainer G. Schaefer

1995-01-01

95

Adsorption of phenol from aqueous solutions using mesoporous carbon prepared by two-stage process  

Microsoft Academic Search

Porous carbon prepared from rice husk using phosphoric acid activation through precarbonization and chemical activation has been examined for the adsorption of phenol from aqueous solutions. The method adopted could produce carbons with micro and mesoporous structure. The surface area, pore volume and pore size distribution of carbon samples activated at three different temperatures 700, 800 and 900°C have been

L. John Kennedy; J. Judith Vijaya; K. Kayalvizhi; G. Sekaran

2007-01-01

96

Removal of Cr(VI) from aqueous solution using activated carbon modified with nitric acid  

Microsoft Academic Search

The adsorption processes of Cr(VI) from aqueous solution onto a granular activated carbon (GAC) and a modified activated carbon (MAC) with nitric acid have been investigated. The surface characteristics of these two activated carbons were measured. The results showed that the MAC has a lower surface area, lower pHIEP and more oxygen functional groups compared with the GAC. Adsorption parameters

Guolin Huang; Jeffrey X. Shi; Tim A. G. Langrish

2009-01-01

97

A comparative study of synthetic graphite and Li electrodes in electrolyte solutions based on ethylene carbonate-dimethyl carbonate mixtures  

Microsoft Academic Search

This work entails a comparative study of both Li and synthetic graphite electrodes in electrolyte solutions based on ethylene and dimethyl carbonates (EC-DMC) and the impact of the salt used [from the LiAsFâ, LiClOâ, LiPFâ, LiBFâ, and LiN(SOâCFâ)â list]. The presence of some additives in solutions (e.g., LiâCOâ, COâ, tributylamine) and the effect of the particle size of the carbon

D. Aurbach; B. Markovsky; A. Schechter; Y. Ein-Eli; H. Cohen

1996-01-01

98

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

Microsoft Academic Search

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

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

2002-01-01

99

Silver electrocrystallization on vitreous carbon from ammonium hydroxide solutions  

SciTech Connect

Leaching baths with ammonia as a complexing agent offer a good alternative for precious metal (e.g., silver) recovery, since the environmental impact of these kind of leaching baths is considerably lower than the traditional cyanidation. The early stages of the electrolytic deposition of silver onto vitreous carbon electrodes from ammonium hydroxide solutions have been investigated by the potential step technique. The analysis of the experimental current transients according to existing theories indicates that this process occurs by multiple three-dimensional nucleation, followed by diffusion controlled growth of nuclei. It is shown that treatments that involve classifying the process as either instantaneous or progressive nucleation are not always adequate for the quantitative analysis of electrochemical nucleation phenomena. The nucleation kinetics parameters A (nucleation rate constant per site) and No (number density of active sites on the substrate surface) were estimated separately from the current transient maxima by two different approaches. Both quantities were found to vary with the potential and with the concentration of silver ions, except at very high overpotentials for silver deposition. The potential dependence of the nucleation rate A was interpreted according to the atomistic theory and in all cases it was found that the number of atoms in the critical nucleus (n{sub k}) was one over the entire potential range analyzed.

Palomar-Pardave, M.; Ramirez, M.T.; Gonzalez, I. [Univ. Autonoma Metropolitana-Iztapalapa (Mexico). Dept. de Quimica; Serruya, A.; Scharifker, B.R. [Univ. Simon Bolivar, Caracas (Venezuela). Dept. de Quimica

1996-05-01

100

Laccase-catalyzed carbon–carbon bond formation: oxidative dimerization of salicylic esters by air in aqueous solution  

Microsoft Academic Search

The laccase catalyzed oxidative dimerization of salicylic esters, a rare example of a laccase-catalyzed carbon–carbon bond formation, was studied. This reaction allows the use of air as stoichiometric oxidant and proceeds in aqueous solution. The preparative scope and the mechanism of the method, which provides a new and convenient access to functionalized biaryls under mild conditions, were investigated.

Sabine Ciecholewski; Elke Hammer; Katrin Manda; Gopal Bose; Van T. H. Nguyen; Peter Langer; Frieder Schauer

2005-01-01

101

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

Microsoft Academic Search

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

Jeom-In Baek; Ji-Ho Yoon

1998-01-01

102

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

Microsoft Academic Search

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

Jian Zhang; Yan Li; Chenglu Zhang; Yuming Jing

2008-01-01

103

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

SciTech Connect

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.

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

1998-07-01

104

Heterogeneity of activated carbons in adsorption of aniline from aqueous solutions  

NASA Astrophysics Data System (ADS)

The heterogeneity of activated carbons (ACs) prepared from different precursors is investigated on the basis of adsorption isotherms of aniline from dilute aqueous solutions at various pH values. The APET carbon prepared from polyethyleneterephthalate (PET), as well as, commercial ACP carbon prepared from peat were used. Besides, to investigate the influence of carbon surface chemistry, the adsorption was studied on modified carbons based on ACP carbon. Its various oxygen surface groups were changed by both nitric acid and thermal treatments. The Dubinin-Astakhov (DA) equation and Langmuir-Freundlich (LF) one have been used to model the phenomenon of aniline adsorption from aqueous solutions on heterogeneous carbon surfaces. Adsorption-energy distribution (AED) functions have been calculated by using an algorithm based on a regularization method. Analysis of these functions for activated carbons studied provides important comparative information about their surface heterogeneity.

Podko?cielny, P.; László, K.

2007-08-01

105

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

Microsoft Academic Search

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

D. Aurbach; A. Zaban

1995-01-01

106

On the black carbon problem and its solutions  

NASA Astrophysics Data System (ADS)

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

Jacobson, M. Z.

2010-12-01

107

Sorption of uranium from nitric acid solution using TBP-impregnated activated carbons  

SciTech Connect

The concept of extraction chromatography has been used to study the sorption of uranium from nitric acid solutions using tri-n-butyl phosphate (TBP) impregnated activated carbons. Batch equilibrium data and kinetic and breakthrough column behavior of uranium are reported. Wood based activated carbon has shown better capacity and breakthrough characteristics than shell based activated carbon. Sorption rate on impregnated carbons was relatively slow indicating that diffusion is the rate controlling step within the pore structure of the activated carbon. Uranium distribution on impregnated activated carbons is compared with equivalent bulk liquid extraction and a mechanism of uranium sorption is discussed.

Abbasi, W.A. [Pakistan Atomic Energy Commission, Islamabad (Pakistan). Pakistan Inst. of Nuclear Science and Technology; Streat, M. [Loughborough Univ. (United Kingdom). Dept. of Chemical Engineering

1998-08-01

108

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

Microsoft Academic Search

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

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

2012-01-01

109

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

SciTech Connect

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

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

2010-02-10

110

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

NASA Astrophysics Data System (ADS)

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

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

2010-02-01

111

Solubility of carbon dioxide in aqueous solutions of 2-amino-2-ethyl-1,3-propanediol  

Microsoft Academic Search

The solubilities of carbon dioxide in aqueous solutions of 2-amino-2-ethyl-1,3-propanediol (AEPD) were measured at 313.15, 323.15, and 333.15K over the partial pressure range of carbon dioxide from 1 to 3000kPa. The concentrations of aqueous AEPD solutions were 10 and 30mass%. The solubilities of carbon dioxide in aqueous 10mass% AEPD solutions at 313.15K and 30mass% at 333.15K were compared with those

Jung-Yeon Park; Sang Jun Yoon; Huen Lee; Ji-Ho Yoon; Jae-Goo Shim; Jae Keun Lee; Byung-Yeon Min; Hee-Moon Eum; Min Cheol Kang

2002-01-01

112

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

PubMed

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

Vaccari, Mentore; Gialdini, Francesca; Collivignarelli, Carlo

2012-11-09

113

Carbonate-modified siloxanes as solvents of electrolyte solutions for rechargeable lithium cells  

Microsoft Academic Search

Influence of mixing carbonate-modified siloxanes into LiPF6-ethylene carbonate (EC)\\/ethylmethyl carbonate (EMC) (mixing volume ratio=3:7) mixed solvent electrolytes on charge–discharge cycling properties of lithium was examined. As the solute, 1M (M: molL?1) LiPF6 was used. As siloxanes, 4-(2-trimethylsilyloxydimethylsilylethyl)-1,3-dioxolan-2-one and 4-(2-bis(trimethylsilyloxy)methylsilylethyl)-1,3-dioxolan-2-one were investigated. These siloxanes are derivatives of butylene cyclic carbonate or vinyl ethylene carbonate. Charge–discharge cycling efficiencies of lithium metal anodes

Takashi Takeuchi; Satoshi Noguchi; Hideyuki Morimoto; Shin-ichi Tobishima

2010-01-01

114

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

SciTech Connect

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

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

2007-08-15

115

Components for the Washing Procedure.  

National Technical Information Service (NTIS)

This report is about the development of a new energy-saving washing system for household washing machines which also reduces the pollution of the environment. Components of the detergents will be stored in the device for a longer period and will be added ...

L. Brodzina S. Klose D. Koos M. Krueger R. Striek

1985-01-01

116

Determination of Free Base in Aluminate-Carbonate Solutions by Standard Addition Method.  

National Technical Information Service (NTIS)

Alkaline waste solutions from the 200-Area separations processes are analyzed for sodium hydroxide, sodium aluminate, and sodium carbonate by a complicated titration procedure that requires about two hours. Frequently, however, only the sodium hydroxide c...

E. W. Baumann

1983-01-01

117

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

Microsoft Academic Search

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

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

2011-01-01

118

Americium and europium extraction from carbonate solutions by 1-phenyl-3-methyl-4-benzoylpyrazolone -5  

Microsoft Academic Search

Trivalent TPEs and REEs are extractable from carbonate solutions by 1-pheny-3-methyl-4-benzoylpyrazolone-5 (PMBP). The effect of concentration of KHCOâ and KâCOâ, extractant, metal, and other factors on the extent of extraction of the elements has been clarified. The kinetics of extraction of the elements from carbonate solutions has been studied. It has been shown that in the KHCOâ concentration range 0.2-2.0

Z. K. Karalova; Deviris E. A; L. A. Fedorov; B. F. Myasoedov; M. S. Rukov

1986-01-01

119

Use of activated carbon in removal of some radioisotopes from their waste solutions  

Microsoft Academic Search

Removal of some radioisotopes namely (152+154)Eu and 65Zn from radioactive solutions by activated carbon using both batch and column techniques has been performed. Experimental studies were conducted to evaluate and optimize the various process variables, i.e., equilibrium time, carbon dose, solution pH. Sorption data have been interpreted in terms of both Freündlich and Langmuir isotherms. The fixed-bed results indicate the

H. A. Omar; H. Moloukhia

2008-01-01

120

Heterogeneity of activated carbons with different surface chemistry in adsorption of phenol from aqueous solutions  

Microsoft Academic Search

The heterogeneity of activated carbons is investigated on the basis of adsorption isotherms of phenol from dilute aqueous solutions at different values of pH in the solution. The original carbon studied was prepared from polyethyleneterephtalate (PET). Its various oxygen surface functionalities were systematically changed by additional nitric acid and heat treatments. The Dubinin–Astakhov adsorption-isotherm equation was used to evaluate the

K. László; P. Podkoscielny; A. Dabrowski

2006-01-01

121

Electrochemical properties of Zn\\/orange dye aqueous solution\\/carbon cell  

Microsoft Academic Search

An investigation is made of the electrochemical properties of a Zn\\/orange dye aqueous solution\\/carbon cell. In this cell, a solution of 3wt.% orange dye (C17H17N5O2) in distilled water is used as the electrolyte and zinc and carbon rods serve as electrodes. The cell is fabricated in a cylindrical glass vessel and has a length and a diameter of 4 and

Khasan S. Karimov; Muhammad H. Sayyad; Mukhtar Ali; Muhammad N. Khan; Syed A. Moiz; Khurram B. Khan; Humera Farah; Zioda M. Karieva

2006-01-01

122

Effect of surface state of carbon fiber electrode on copper electroplating from sulfate solutions  

Microsoft Academic Search

The effect of the fiber surface state of a carbon fiber fabric on the parameters of copper electro-plating from a sulfate\\u000a solution (the copper current efficiency, the electroplating rate, and the deposit distribution in the depth of electrode)\\u000a is studied. The surface state of fibers was changed by preliminarily polarizing the carbon fiber fabric in electrolyte solutions.\\u000a The change in

V. I. Varentsova; V. K. Varenstov; I. A. Bataev; S. I. Yusin

2011-01-01

123

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

Microsoft Academic Search

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

Karthik Subramanian; John Mickalonis

2005-01-01

124

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

Microsoft Academic Search

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

Lotfi Mouni; Djoudi Merabet; Abdelkrim Bouzaza; Lazhar Belkhiri

2011-01-01

125

Adsorption of boron from aqueous solutions using activated carbon prepared from olive bagasse  

Microsoft Academic Search

In this study, activated carbon was prepared from olive bagasse by physical 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 803 mg. In this study, boron removal from aqueous solutions by adsorption was investigated. In the batch mode

T. Ennil Köse; Hakan Demiral; Ne?e Öztürk

2011-01-01

126

Irreversible and reversible adsorption of some heavy transition metals on graphitic carbons from dilute aqueous solutions  

Microsoft Academic Search

The adsorption of various heavy transition metal compounds was studied using two different flow adsorption methodologies: flow injection adsorption and flow equilibrium adsorption analyses. In both cases the determinations were made of the heats of adsorption and the amounts of adsorption from dilute aqueous solutions.The carbons used for the work included two different types of graphitised carbon black and active

A. J. Groszek

1997-01-01

127

Simple Method for Simultaneous Determination of Carbonate, Sulfite and Hydroxide in Solution  

NASA Astrophysics Data System (ADS)

A method is proposed for the simultaneous determination of carbon dioxide and sulphur dioxide in a complex matrices. The method involves salvation of the tow gases in Sodium Hydroxide solution followed by simultaneous determination of the three species (carbonate, sulfite and hydroxide) using conductometric and potentiometric titration. What set this method apart from other determination methods it`s simplicity.

Al-Itawi, Hossam I.; Al-Ebaisat, Hamdan; Al-Garaleh, Mazen

128

Reactions of rare earth flourides with sodium carbonate and hydroxide solutions  

Microsoft Academic Search

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

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

1986-01-01

129

Removal of copper (II) and phenol from aqueous solution using porous carbons derived from hydrothermal chars  

Microsoft Academic Search

The feasibility of hydrothermal char (HTC), a byproduct from biomass hydrothermal liquefaction for bio-oil production, as raw material for preparation of porous carbons was investigated in the present study. The resultant HTC-derived porous carbons were characterized and utilized as adsorbents for copper (II) and phenol removal from aqueous solution. Compared with porous carbons using pyrolytic char as precursor, the HTC-derived

Zhengang Liu; Fu-Shen Zhang

2011-01-01

130

ESR study of 13 C-enriched carbonated calciumapatites precipitated from aqueous solutions  

Microsoft Academic Search

The ESR spectrum of X-irradiated carbonated apatites precipitated from aqueous solutions was studied at carbonate contents ranging from approximately 5.4 up to 12.4 wt%. 12C- as well as 13C-enriched samples were prepared and examined with ESR after drying until constant weight at 25°C and 400°C. In these carbonated apatites, two CO33- radicals were detected, one of which is derived from

F. J. Callens; R. M. H. Verbeeck; D. E. Naessens; P. F. A. Matthys; E. R. Boesman

1993-01-01

131

PROCESS FOR RECOVERY OF URANIUM AND VANADIUM FROM CARBONATE SOLUTIONS BY REDUCTION-PRECIPITATION  

DOEpatents

A process employing carbonate leaching of ores and an advantageous methcd of recovering the uranium and vanadium from the leach solution is described. The uranium and vanadium can be precipitated from carbonate leach solutions by reaction with sodium amalgam leaving the leach solution in such a condition that it is economical to replenish for recycling. Such a carbonate leach solution is treated with a dilute sodium amalgam having a sodium concentration within a range of about 0.01 to 0.5% of sodium. Efficiency of the treatment is dependent on at least three additional factors, intimacy of contact of the amalgam with the leach solution, rate of addition of the amalgam and exclusion of oxygen (air).

Ellis, D.A.; Lindblom, R.O.

1957-09-24

132

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

SciTech Connect

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

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

1994-05-13

133

Corrosion Behavior of Mild Carbon Steel in Ethanolic Solutions  

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

134

EXTRACTION AND SEPARATION OF ACTINIDES AND LANTHANIDES FROM ALKALINE AND CARBONATE SOLUTIONS  

Microsoft Academic Search

The review generalizes the results on the extraction of actinides, lanthanides and other elements from alkaline and carbonate solutions with the extractants of various classes. It discusses the mechanisms of the processes and practical possibilities of the separation of elements in alkaline solutions.

Z. K. Karalova; B. F. Myasoedov; T. I. Bukina; E. A. Lavrinovich

1988-01-01

135

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

EPA Science Inventory

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

136

Adsorption of naphthalene from aqueous solution on activated carbons obtained from bean pods.  

PubMed

The preparation of activated carbons from bean pods waste by chemical (K(2)CO(3)) and physical (water vapor) activation was investigated. The carbon prepared by chemical activation presented a more developed porous structure (surface area 1580 m(2) g(-1) and pore volume 0.809 cm(3) g(-1)) than the one obtained by water vapor activation (258 m(2) g(-1) and 0.206 cm(3) g(-1)). These carbons were explored as adsorbents for the adsorption of naphthalene from water solutions at low concentration and room temperature and their properties are compared with those of commercial activated carbons. Naphthalene adsorption on the carbons obtained from agricultural waste was stronger than that of carbon adsorbents reported in the literature. This seems to be due to the presence of large amounts of basic groups on the bean-pod-based carbons. The adsorption capacity evaluated from Freundlich equation was found to depend on both the textural and chemical properties of the carbons. Naphthalene uptake on biomass-derived carbons was 300 and 85 mg g(-1) for the carbon prepared by chemical and physical activation, respectively. Moreover, when the uptake is normalized per unit area of adsorbent, the least porous carbon displays enhanced naphthalene removal. The results suggest an important role of the carbon composition including mineral matter in naphthalene retention. This issue remains under investigation. PMID:18541368

Cabal, Belen; Budinova, Temenuzhka; Ania, Conchi O; Tsyntsarski, Boyko; Parra, José B; Petrova, Bilyana

2008-05-03

137

Synthesis of calcium carbonate in a pure ethanol and aqueous ethanol solution as the solvent  

NASA Astrophysics Data System (ADS)

The possibility of formation of precipitated calcium carbonate (PCC) in pure ethanol, not as small additives, but as the main solvent, was investigated by precipitating a variety of PCC via a carbonation reaction. During the carbonation in a slaked lime pure ethanol suspension, three morphology types of CaCO3 were also precipitated, including calcite, which was the only type of PCC precipitated in the pure water system, and aragonite and vaterite, which were also precipitated without leaving Ca(OH)2 as the reactants. Their particle size was half of those from pure water. In a pure ethanol system, calcite was first precipitated from the carbonation in bulk solution as in the pure water system, while the aragonite and vaterite might be synthesized via other local carbonation routes occurring in the surface of the Ca(OH)2 grain following the bulk carbonation in the solution. In this local carbonation, there was little variation of electrical conductivity and pH. In the aqueous solution of less than 40 mol% ethanol, the PCC is all calcite; therefore, water has dominant effect as the solvent. On the other hand, in the solution of more than 60 mol% ethanol, the solvent acts as the pure ethanol and calcite, aragonite and vaterite can be precipitated.

Seo, Kang-Seok; Han, Choon; Wee, Jung-Ho; Park, Jin-Koo; Ahn, Ji-Whan

2005-04-01

138

Ecological Engineering promotes Carbon Reduction Solutions for a Sustainable Planet  

Microsoft Academic Search

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

Stephen Bedford Clark

2009-01-01

139

Carbon monoxide … the silent killer with an audible solution  

Microsoft Academic Search

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

Edward P Krenzelok; Ronald Roth; Robert Full

1996-01-01

140

Kinetic study of pyrite oxidation in basic carbonate solutions  

Microsoft Academic Search

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

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

1987-01-01

141

Inhibition Effect of Dodecylamine on Carbon Steel Corrosion in Hydrochloric Acid Solution  

NASA Astrophysics Data System (ADS)

Dodecylamine spontaneously adsorbs on carbon steel via its polar group (-NH2) in hydrochloric acid solution. Furthermore, it forms a monolayer film on carbon steel surface. The inhibition mechanism of dodecylamine for carbon steel is geometric blocking effect. The adsorption of dodecylamine on carbon steel surface follows Arrhenius equation. The adsorption slightly increases activated energy, but greatly reduces pre-exponential factor value. Atomic force microscopy force curves indicate that at the area without adsorbed dodecylamine, no obvious adhere force occurs. At the area with adsorbed dodecylamine, however, an average 1.3 nN adhere force is observed.

Chen, Zhenyu; Huang, Ling; Qiu, Yubing; Guo, Xingpeng

2012-12-01

142

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

Microsoft Academic Search

Americium and europium extraction from alkali solutions in presence of tartrate and carbonate ions using 2-hydroxy-5-alkylbenzyldiethanolamine (DEAP) in different diluents as a function of NaOH, NaâCâHâOâ, KâCOâ, extractant and metal concentration, and pH of the medium has been studied. It was found that americium is extracted to the maximum by 1 M DEAP solution in hexane from tartrate solutions with

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

1988-01-01

143

Analysis of solute distribution in dendrites of carbon steel with ?\\/? transformation during solidification  

Microsoft Academic Search

Solute distribution in dendrites during solidification of carbon steel was analyzed by unidirectional solidification experiments\\u000a and mathematical analysis. The characteristic of the mathematical analysis is that diffusion of solutes in solid and redistribution\\u000a of solutes at solid\\/liquid and?\\/? interfaces are taken into consideration. Based on the observed and calculated results, it was found that phosphorus was redistributed\\u000a from?-phase to?-phase, and

Yoshiyuki Ueshima; Shozo Mizoguchi; Tooru Matsumiya; Hiroyuki Kajioka

1986-01-01

144

Spectroscopic and Electrochemical Studies of Selected Lanthanides and Actinides in Concentrated Aqueous Carbonate and Carbonate-Hydroxide Solutions and in Molten Dimethyl Sulfone.  

National Technical Information Service (NTIS)

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), ...

P. G. Varlashkin

1985-01-01

145

Insulator hot washing with deionized water  

Microsoft Academic Search

The evolution of hot washing insulators with deionized water is reviewed and the most recent washing equipment and practices are described. The effect of increasing the effective washing distance through the use of \\

Jamison C. Johnson

1976-01-01

146

pH-metric determination of ammonium carbonate and bicarbonate in solutions containing ammonium vanadate  

SciTech Connect

Ammonium carbonate and bicarbonate and ammonium carbonate salts used in hydrometallurgy are characterized by low stability both in solid form and in solutions. The frequently used method of acid-base titration in the presence of a pH indicator is unsuitable in the presence of ions in solution that change color within the investigated pH range. The purpose of this paper is to develop a method of rapid determination of the concentration of ammonium carbonate and bicarbonate in solutions containing ammonium vanadate. The authors used a 0.1 M solution of hydrochloric acid, analytical grade ammonium vanadate, and ammonium carbonate salts, the composition of which approximates real technological solutions. An aliquot portion of the test solution (1-2 ml) is transferred to a 50-ml beaker, and 10 ml of distilled water is added. The electrodes of the pH meter are placed in the solution, and it is titrated with 0.1 M hydrochloric acid with constant mixing.

Fofanov, Al.A.; Yuorenko, V.V.; Kharlampieva, T.I.; Potapov, V.I.

1986-07-01

147

Synthesis of silicon\\/carbon, multi-core\\/shell microspheres using solution polymerization for a high performance Li ion battery  

Microsoft Academic Search

In this work, silicon–carbon composite particles were designed and synthesized for the anode materials of a lithium ion battery and synthesized using a simple method that is adaptable for industrial application. The silicon\\/carbon precursor and monomer mixtures were polymerized through solution polymerization in an organic continuous medium and granulated in a polyvinyl alcohol (PVA) aqueous solution. After carbonization of the

Kyomin Shin; Dae-Jin Park; Hyung-Seok Lim; Yang-Kook Sun; Kyung-Do Suh

148

Leaching kinetics of malachite in ammonium carbonate solutions  

Microsoft Academic Search

Leaching of malachite was conducted with ammonium carbonate as lixiviant and with temperature, lixiviant concentration, and particle size as variables. Two stages of reaction were found. In Stage I, the initial dissolution of malachite proceeds rapidly, but after about 10 pct reaction the rate is reduced by surface blockage due to the presence of a needle-structured intermediate, presumably Cu(OH)2. Subsequently,

Paul D. Oudenne; Ferron A. Olson

1983-01-01

149

Leaching kinetics of malachite in ammonium carbonate solutions  

Microsoft Academic Search

Leaching of malachite was conducted with ammonium carbonate as lixiviant and with temperature, lixiviant concentration, and\\u000a particle size as variables. Two stages of reaction were found. In Stage I, the initial dissolution of malachite proceeds rapidly,\\u000a but after about 10 pct reaction the rate is reduced by surface blockage due to the presence of a needle-structured intermediate,\\u000a presumably Cu(OH)2. Subsequently,

Paul D. Oudenne; Ferron A. Olson

1983-01-01

150

Alkaline solution absorption of carbon dioxide method and apparatus  

DOEpatents

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

Hobbs, D.T.

1991-01-01

151

A simple solution for the determination of pristine carbon nanotube concentration.  

PubMed

Upon dispersant-assisted exfoliation, pristine carbon nanotubes (CNTs) are divided between the supernatant and precipitate, which makes the determination of dispersant concentration a challenging task. We have developed a thermogravimetric-spectroscopy-based approach to accurately determine the dispersant-assisted CNT (or nanoparticles, in general) concentration in dispersion. A thermogravimetric analysis of the filtered and washed precipitate, that is usually discarded after centrifugation, is used here to accurately calculate the CNT mass in the precipitate and (through mass-balance) its mass in the supernatant. Once the true CNT concentration has been determined, a conventional spectroscopy-based concentration calibration plot is constructed for simple and swift use in further concentration measurements. Such true concentration analysis is crucial for studying the concentration-property relationship. PMID:23330147

Shtein, Michael; Pri-bar, Ilan; Regev, Oren

2013-03-01

152

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

Microsoft Academic Search

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

Matthew Jared Evans

2003-01-01

153

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

SciTech Connect

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.

Kitten, S.; Cappiello, C.

1998-06-01

154

Stability of carbon nanowalls against chemical attack with acid solutions  

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

155

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

SciTech Connect

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.

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

156

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

157

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

PubMed

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

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

2009-08-19

158

Mechanical degradation of polyacrylamide solutions in core plugs from several carbonate reservoirs  

SciTech Connect

This paper presents results of laboratory studies on mechanical degradation of partially hydrolyzed polyacrylamide (HPAM) solutions in core samples from several different carbonate reservoirs. Studies in carbonates are of particular importance because several of the larger polymer projects are in carbonate reservoirs and because data on carbonate rocks have not previously been available. Much of the data in the literature was obtained with solutions of polymer in brine. Since HPAM polymers are generally more efficient in fresh waters, lower salinity waters were used for the bulk of the present study. Variables investigated included: polymer molecular weight, polymer concentration, and salinity of the aqueous solvent. The HPAM samples used were commercial products of varying molecular weight. Results were compared to correlations previously developed for sandstone core plugs and uncosolidated sands.

Martin, F.D.

1984-04-01

159

Phosphate Removal from Aqueous Solution Using Coir-Pith Activated Carbon  

Microsoft Academic Search

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

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

2010-01-01

160

Kinetics and equilibrium of adsorption of organic solutes on mesoporous carbons  

NASA Astrophysics Data System (ADS)

Static and kinetic studies on adsorption of nitrobenzene, 4-nitrophenol and 4-chlorophenol on two mesoporous carbons are performed. The carbon properties are analyzed by means of nitrogen adsorption. The adsorption experiments are performed in acidic buffer solutions in a wide range of concentrations. The static experiments are analyzed by means of Langmuir Freundlich and Freundlich isotherms. The Lagergren, pseudo-second-order, intraparticle-diffusion and multi-exponent equations are used in the analysis of kinetic equilibria.

Marczewski, Adam W.

2007-04-01

161

Removal of Acid Dyes from Aqueous Solutions using Chemically Activated Carbon  

Microsoft Academic Search

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

Özgül Gerçel; H. Ferdi Gerçel

2009-01-01

162

Removal of heavy metals from aqueous solutions using activated carbon prepared from Cicer arietinum  

Microsoft Academic Search

Removal of Cu, Cd, Pb, and Zn from aqueous solutions by activated carbon prepared from stems and seed hulls of Cicer arietinum, an agricultural solid waste, has been studied. The influence of various parameters, such as pH, contact time, adsorbent dose, and initial concentration of metal ions on removal was evaluated. The activated carbon was characterized by FT-IR spectroscopy, X-ray

D. K. V. Ramana; K. Jamuna; B. Satyanarayana; B. Venkateswarlu; M. Madava Rao; K. Seshaiah

2010-01-01

163

Enhanced sludge washing evaluation plan  

SciTech Connect

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

Jensen, R.D.

1994-09-01

164

Solubility of carbon dioxide in aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol  

Microsoft Academic Search

The solubility of CO2 in aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD) was measured for AHPD mass fractions w=0.0015,0.005,0.01?and?0.025 at 283.15, 298.15 and 313.15K and for CO2 partial pressures within 2–75kPa. These ranges were compatible with aqueous solutions in use in a CO2 capture process using human carbonic anhydrase metalloenzyme. The influence of carbonic anhydrase on the solubility of CO2 in AHPD

David Le Tourneux; Ion Iliuta; Maria C. Iliuta; Sylvie Fradette; Faïçal Larachi

2008-01-01

165

Soil washing and radioactive contamination  

SciTech Connect

Soil washing, a technique combining both physical and chemical processes to produce significant volume reduction of contaminated soils, is widely regarded as a panacea for the huge inventory of contaminated soils in the DOE Complex. While the technology has been demonstrated for organics and to some extent for metals, review of the publications available on the practical applications to radioactive sites, indicates that most volume reduction is a product of unique circumstances such as screening or floating out non-soil materials containing most of the contaminants, or leaching contaminants (uranium or TRU) that exist as anionic complexes (Grant, 1991) which are not held by the soil cation-exchange-capacity. In either case, the potential for success of the technology is extremely site and contaminant specific. The Environmental Protection Agency's (EPA) guidance on soil washing treatability studies suggests a 50% reduction of contamination in particles over 2mm as a reasonable cutoff for choosing soil washing for further development (EPA, 1991).

Gombert, D.; Bosley, J.B.

1992-03-20

166

Kinetic peculiarities of diamond crystallization in K-Na-Mg-Ca-Carbonate-Carbon melt-solution  

NASA Astrophysics Data System (ADS)

The kinetic peculiarities of diamond crystallization in multicomponent K-Na-Mg-Ca-carbonate-carbon system have been studied in conditions of diamond stability at 1500-1800°C and 7.5-8.5 GPa. It has been established that the diamond phase nucleation density at a fixed temperature of 1600°C decreases from 1.3 × 105 nuclei/mm3 at 8.5 GPa to 3.7 × 103 nuclei/mm3 at 7.5 GPa. The fluorescence spectra of obtained diamond crystals contain peaks at 504 nm ( H3-defect), 575 nm (NV-center), and 638 nm (NV-defect), caused by the presence of nitrogen impurity. In the cathodoluminescence spectra, an A-band with the maximum at 470 nm is present. The obtained data make it possible to assign the synthesized diamonds in the carbonate-carbon system to the mixed Ia + Ib type.

Solopova, N. A.; Spivak, A. V.; Litvin, Yu. A.; Shiryaev, A. A.; Tsel'movich, V. A.; Nekrasov, A. N.

2013-02-01

167

A study of carbon dioxide absorption into aqueous monoethanolamine solution containing calcium nitrate in the gas–liquid reactive precipitation of calcium carbonate  

Microsoft Academic Search

The influence of calcium nitrate on the process of carbon dioxide absorption in aqueous monoethanolamine (MEA) solution has been considered. The experimental data obtained under typical conditions used for the industrial precipitation of calcium carbonate has been used to determine the speciation in solution and the supersaturation profile in the bulk liquid by means of a specially developed algorithm as

M Vu?ak; J Peri?; A Žmiki?; M. N Pons

2002-01-01

168

Extraction of lanthanides from acidic solution using tributyl phosphate modified supercritical carbon dioxide  

Microsoft Academic Search

The feasibility of using supercritical carbon dioxide as a substitute extraction solvent in nuclear reprocessing was tested by the extraction of lanthanide ions from acidic solution. Lanthanides were extracted from 6 M HNO[sub 3]-3 M LiNO[sub 3] solutions using tributyl phosphate- (TBP-) modified CO[sub 2]. Synergistic effects were also investigated using a combination of thenoyltrifluoroacetone (TTA) and TBP-modified CO[sub 2

K. E. Laintz; E. Tachikawa

1994-01-01

169

Adsorption of phenol based organic pollutants on activated carbon from multi-component dilute aqueous solutions  

Microsoft Academic Search

Five organic phenolic compounds (phenol, o-chlorophenol, m-chlorophenol, p-chlorophenol and m-cresol) have been used to determine the adsorption isotherms for single and bisolute systems from dilute aqueous solutions on activated carbon. An experimental technique for the analysis of the equilibrium concentration of a bisolute in aqueous solutions using a UV spectrophotometer has been successfully developed and employed. Experimental data were obtained

A. R. Khan; T. A. Al-Bahri; A. Al-Haddad

1997-01-01

170

Electrochemical treatment of dilute cyanide solutions containing zinc complexes by oxidation at carbon felt (Sigratherm)  

Microsoft Academic Search

The electrochemical oxidation of dilute solutions containing cyanide complexes of zinc using a carbon felt anode is described. The composition of the solution was determined using stability constants for particular complexes. The application of a GFA5 electrode enables the oxidation of cyanides (10 mmol dm-3) in 99.2% at 0.7 V and 30 C (1.5 Qt). Under these conditions, the electrical

A. Socha; E. Ku?mierek; E. Chrze?cija?ska

2002-01-01

171

Formation mechanism of carbon nanotubes in the gas-phase synthesis from colloidal solutions of nanoparticles  

Microsoft Academic Search

Single- and multi-wall carbon nanotubes have been synthesized by the gas-phase catalytic reaction of colloidal solutions of metal nanoparticles using a vertical flow reactor. The reverse micelle solution of the Co–Mo nanoparticles with the mean diameter of 11 nm dissolved in toluene was injected directly into the reactor maintained at 1200 °C. The nanoparticles and the solvent act as the

Hiroki Ago; Satoshi Ohshima; Kazuhito Tsukuagoshi; Masaharu Tsuji; Motoo Yumura

2005-01-01

172

Inhibitory mechanism of low-carbon steel corrosion by mimosa tannin in sulphuric acid solutions  

Microsoft Academic Search

Mimosa tannin was investigated as inhibitor of low-carbon steel sulphuric acid corrosion in concentrations from 10-5 to 10-1 mol L-1, at the temperature of 298 K in the solutions of pH 1, 2 and 3. The inhibitor effectiveness increases with increase in concentration. The adsorptive behaviour of mimosa tannin in solutions of pH 1 and 2 may be approximated, both

S. Martinez; I. Štern

2001-01-01

173

Characterization and kinetics of carbon dioxide absorption into aqueous tetramethylammonium glycinate solution  

Microsoft Academic Search

An advanced aqueous amine solvent of tetramethylammonium glycinate ([N1111][Gly]) was characterized for carbon dioxide (CO2) absorption purposes. Density, viscosity and pH of the [N1111][Gly] solution, with concentrations ranging from 5% to 30%, were determined at temperatures from 298 to 323K. Solubility and diffusivity of CO2 in [N1111][Gly] solution at the same temperatures and concentrations was estimated. Absorption of CO2 into

Jing Guo-Hua; Zhou Lan-Juan; Zhou Zuo-Ming

174

Modeling of Enthalpy of Solution of Carbon Dioxyde in Aqueous Solution of Amine  

Microsoft Academic Search

The {CO2-H2O-amine} systems are of interest in order to develop carbon dioxide (CO2) capture processes. Because of environmental impact, particularly for global warming effect, CO2 emissions have to be limited. One option is to remove CO2 from post combustion effluent in industries such as cement, metallurgy or power plants. The most common processes are based on cycles of gas absorption

Jean Yves; Coxam C; Laurence Rodier; Karine Ballerat-Busserolles; Hugues Arcis

175

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

Microsoft Academic Search

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

V. Linek; J. Sinkule; T. Moucha; J. F. Rejl

2009-01-01

176

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

PubMed

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 ZnCl(2) as activating reagents. Adsorption of Hg(II) from aqueous solutions was carried out under different experimental conditions by varying treatment time, metal ion concentration, pH and solution temperature. It was shown that Hg(II) uptake decreases with increasing pH of the solution. The proper choice of preparation conditions were resulted in microporous activated carbons with different BET surface areas of 780 (Carbon A, 1:0.5 ZnCl(2)) and 803 (Carbon B, 1:1 ZnCl(2))m(2)/g BET surface area. The monolayer adsorption capacity of these particular adsorbents were obtained as 151.5 and 100.9 mg/g for carbons A and B, respectively. It was determined that Hg(II) adsorption follows both Langmuir and Freundlich isotherms as well as pseudo-second-order kinetics. PMID:19833433

Zabihi, M; Haghighi Asl, A; Ahmadpour, A

2009-09-19

177

Adsorption of phenol and reactive dye from aqueous solution on activated carbons derived from solid wastes.  

PubMed

Activated carbons were produced from several solid wastes, namely, waste PET, waste tires, refuse derived fuel and wastes generated during lactic acid fermentation from garbage. Activated carbons having various pore size distributions were obtained by the conventional steam-activation method and via the pre-treatment method (i.e., mixture of raw materials with a metal salt, carbonization and acid treatment prior to steam-activation) that was proposed by the authors. The liquid-phase adsorption characteristics of organic compounds from aqueous solution on the activated carbons were determined to confirm the applicability of these carbons, where phenol and a reactive dye, Black5, were employed as representative adsorbates. The hydrophobic surface of the carbons prepared was also confirmed by water vapor adsorption. The characteristics of a typical commercial activated carbon were also measured and compared. It was found that the activated carbons with plentiful mesopores prepared from PET and waste tires had quite high adsorption capacity for large molecules. Therefore they are useful for wastewater treatment, especially, for removal of bulky adsorbates. PMID:15026233

Nakagawa, Kyuya; Namba, Akio; Mukai, Shin R; Tamon, Hajime; Ariyadejwanich, Pisit; Tanthapanichakoon, Wiwut

2004-04-01

178

Americium and europium extraction from carbonate solutions by 1-phenyl-3-methyl-4-benzoylpyrazolone -5  

SciTech Connect

Trivalent TPEs and REEs are extractable from carbonate solutions by 1-pheny-3-methyl-4-benzoylpyrazolone-5 (PMBP). The effect of concentration of KHCO/sub 3/ and K/sub 2/CO/sub 3/, extractant, metal, and other factors on the extent of extraction of the elements has been clarified. The kinetics of extraction of the elements from carbonate solutions has been studied. It has been shown that in the KHCO/sub 3/ concentration range 0.2-2.0 M americium and europium are extracted by PMBP solutions in different diluents with distribution coefficients lying within n x 10/sup 2/-n x 10/sup 3/. From K/sub 2/CO/sub 3/ solutions the elements are extracted better by PMBP solutions in methyl isobutyl ketone (MIBK). It has been shown that metal concentration in the range 1x10/sup -5/. 5x10/sup -3/ g-ion x liter/sup -1/ does not affect extraction (log E = 3). Extracts based on PMBP with a metal content higher than 5x10/sup -3/g-ion x liter/sup -1/ were obtained by absolute concentrating method and were used for the study of /sup 13/C NMR spectra. The composition of thecompounds extracted by PMBP from carbonate solutions was determined by /sup 13/C NMR spectroscopy and extraction. The conditions of europium and americium reextraction from extracts based on PMBP by complexones, their mixtures with alkalis and other substances were studied. The scopes for using the system PMBP-carbonate solutions to separate and concentrate TPEs and REEs has been examined.

Karalova, Z.K.; Deviris E.A.; Fedorov, L.A.; Myasoedov, B.F.; Rukov, M.S.

1986-09-01

179

Assessing the Implications of Process Variations on Future Carbon Nanotube Bundle Interconnect Solutions  

Microsoft Academic Search

In this paper, we investigate the impact of process variations on future interconnect solutions based on single-walled carbon nanotubes (SWCNT) bundles. Leveraging an equivalent RLC model for SWCNT bundle interconnect, we calculate the relative impact of ten potential sources of variation in SWCNT bundle interconnect on resistance, capacitance, inductance, and delay. We compare the relative impact of variation for SWCNT

Arthur Nieuwoudt; Yehia Massoud

2007-01-01

180

Adsorption of copper from aqueous solution by activated carbons obtained by pyrolysis of cassava peel  

Microsoft Academic Search

Activated carbons (ACs) were prepared by pyrolysis of cassava peel in presence of chloride zinc (chemical activities). Cassava peel from Colombian cassava cultives were impregnated with aqueous solutions of ZnCl2 following a variant of the incipient wetness method. Different concentrations were used to produce impregnation ratios of 40, 70, 110 and 160wt.%. Activation was carried out under argon flow by

J. C. Moreno-Piraján; L. Giraldo

2010-01-01

181

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

Microsoft Academic Search

The use of two activated carbon fibres, one laboratorial sample prepared from a commercial acrylic textile fibre and one commercial sample of Kynol®, as prepared\\/received and modified by reaction with powdered sulfur and H2S gas in order to increase the sulfur content were studied for the removal of mercury from aqueous solution and from flue gases from a fluidized bed

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

2006-01-01

182

Intramolecular carbon isotopic analysis of acetic acid by direct injection of aqueous solution  

Microsoft Academic Search

We report an improved method for determining the intramolecular carbon isotopic composition of acetate using direct injection of aqueous samples. The system builds upon prior work that established pyrolytic conditions for online analysis and represents a significant advance in that it requires minimal preparation for samples containing as little as 1mM sodium acetate in aqueous solution. The technique is applicable

Burt Thomas; Katherine H. Freeman; Michael A. Arthur

2009-01-01

183

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

SciTech Connect

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

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

2001-11-15

184

Solution Casting and Transfer Printing Single-Walled Carbon Nanotube Films  

Microsoft Academic Search

This paper presents methods for solution casting and transfer printing collections of individual single-walled carbon nanotubes (SWNTs) onto a wide range of substrates, including plastic sheets. The deposition involves introduction of a solvent that removes surfactant from a suspension of SWNTs as it is applied to a substrate. The subsequent controlled flocculation (cF) produces films of SWNTs with densities that

Matthew A. Meitl; Yangxin Zhou; Anshu Gaur; Seokwoo Jeon; Monica L. Usrey; Michael S. Strano; John A. Rogers

2004-01-01

185

Removal of copper from aqueous solutions by adsorption onto chestnut shell and grapeseed activated carbons  

Microsoft Academic Search

Activated carbons prepared from chestnut shell and grapeseed were used as adsorbent for the removal of Cu (II) ions from aqueous solutions. Adsorption experiments were performed by varying initial metal ion concentration, temperature and pH. Freundlich and Langmuir isotherms were used to analyze the equilibrium data obtained at different adsorption conditions. It was observed that Freundlich isotherm provided better fit

Didem Özçimen; Ay?egül Ersoy-Meriçboyu

2009-01-01

186

Elution of zinc in dust discharged from electric arc furnace in carbonic acid solution  

Microsoft Academic Search

The dust discharged from an electric arc furnace (EAF) is a valuable resource of zinc. As a fundamental study of extraction of zinc, iron and chlorine in the EAF dust, the elution behavior of them in carbonic acid solution was studied. The influence of the weight of the EAF dust on the elution behavior was examined in this study. Experiment

S Yokoyama; T Sasaki; J Sasano; M Izaki

2012-01-01

187

Separation of uranium from carbonate-containing solutions thereof by direct precipitation  

SciTech Connect

A direct precipitation method based on the insolubility of uranyl phosphate in carbonate containing solutions at pH 6-6.5 and its insolubility at pH 8 is described. The method eliminates the use of ion exchange columns for removing uranium values from uranium leachates and can be readily applied to an integrated field operation.

Otto, J.B. Jr.

1983-10-18

188

Abdominopelvic washings: A comprehensive review.  

PubMed

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

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

2013-04-24

189

A Window-Washing Challenge  

ERIC Educational Resources Information Center

|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…

Roman, Harry T.

2010-01-01

190

Adsorption characteristics of carbon tetrachloride from aqueous solution onto polyacrylonitrile-based activated carbon fiber  

Microsoft Academic Search

The isotherm, mechanism and kinetics of carbon tetrachloride (CT) adsorption by polyacrylonitrile-based activated carbon fiber\\u000a (PAN-ACF) were investigated in batch reactors and a continuous flow reactor, and the regeneration of PAN-ACF was also studied.\\u000a Freundlich and Dubinin-Radushkevich (D-R) adsorption equations can well describe the adsorption isotherm. CT is mainly adsorbed\\u000a on the exterior surface of PAN-ACF with low boundary layer

Wen-xia Liu; Bao-hong Guan; Jie Yu

2010-01-01

191

A comparative study of synthetic graphite and Li electrodes in electrolyte solutions based on ethylene carbonate-dimethyl carbonate mixtures  

SciTech Connect

This work entails a comparative study of both Li and synthetic graphite electrodes in electrolyte solutions based on ethylene and dimethyl carbonates (EC-DMC) and the impact of the salt used [from the LiAsF{sub 6}, LiClO{sub 4}, LiPF{sub 6}, LiBF{sub 4}, and LiN(SO{sub 2}CF{sub 3}){sub 2} list]. The presence of some additives in solutions (e.g., Li{sub 2}CO{sub 3}, CO{sub 2}, tributylamine) and the effect of the particle size of the carbon on the electrode`s behavior were investigated. The correlation between the surface chemistry, the morphology, and the performance of Li and graphite electrodes was explored using surface sensitive Fourier transform infrared and X-ray and photoelectron spectroscopies, impedance spectroscopy, X-ray diffraction and scanning electron microscopy in conjunction with standard electrochemical techniques. Synthetic graphite anodes could be cycled (Li intercalation-deintercalation) hundreds of times at a capacity close to the optimal (x = 1 in Li{sub x}C{sub 6}) in C-DMC solutions due to the formation of highly stable and passivating surface films in which EC reduction products such as (CH{sub 2}OCO{sub 2}Li){sub 2} are the major constituents. The cycling efficiency of Li metal anodes in these solutions, however, is lower than that obtained in ethereal solutions and seems to be too low for Li-metal liquid electrolyte, rechargeable battery application. The connection between the solution composition and the electrode`s performance is discussed.

Aurbach, D.; Markovsky, B.; Schechter, A.; Ein-Eli, Y. [Bar-Ilan Univ., Ramat Gan (Israel). Dept. of Chemistry; Cohen, H. [Weizmann Inst. of Science, Rehovoth (Israel). Chemical Service Unit

1996-12-01

192

Poly3-hydroxybutyrate production by washed cells of Alcaligenes eutrophus; purification, characterisation and potential regulatory role of citrate synthase  

Microsoft Academic Search

Washed cells prepared from carbon-limited continuous cultures of Alcaligenes eutrophus synthesised poly-3-hydroxybutyrate (PHB) rapidly when supplied with glucose, dl-lactate or l-lactate. Unlike growing cultures, washed cells excreted significant amounts of pyruvate. The combined rates of PHB production\\u000a (qPHB) and pyruvate excretion (qPyr) were linearly related to the rate of carbon substrate utilisation (qS), showing that\\u000a washed cells behaved similarly to

Robin A. Henderson; C. W. Jones

1997-01-01

193

Current Intelligence Bulletin 56. Washed Cotton: A Review and Recommendations Regarding Batch Kier Washed Cotton.  

National Technical Information Service (NTIS)

The information available regarding batch kier washed cotton was reviewed, including the 1978 OSHA Cotton Dust Standard, the 1978 complete exception for severly washed cotton, limitations of the 1978 exemption, washed cotton in the 1985 revision of the st...

1995-01-01

194

Effect of oxygen surface groups on adsorption of benzene derivatives from aqueous solutions onto active carbon samples  

Microsoft Academic Search

The process of adsorption of selected benzene derivatives from aqueous solution is investigated on two carbonaceous materials of differentiated surface properties – quantity of oxygen functional groups. Carbon samples were prepared by removal of external layers from granules of unmodified and oxidized active carbon. The surface and structure characteristics of carbon samples were estimated by various methods. The experimental isotherms

Anna Derylo-Marczewska; Bronislaw Buczek; Andrzej Swiatkowski

2011-01-01

195

Comparison of alternative washing systems for heliostats  

SciTech Connect

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

Kerstein, A.

1981-04-01

196

Approximate Solutions for a Self-Folding Problem of Carbon Nanotubes  

SciTech Connect

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

Y Mikata

2006-08-22

197

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

SciTech Connect

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

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

2010-01-01

198

Catalytic Ozonation for the Degradation of P-Chlorobenzoic Acid in Aqueous Solution by Ni Supported Activated Carbon  

Microsoft Academic Search

Catalytic ozonation of p-chlorobenzoic acid (p-CBA) in aqueous solution has been carried out where transitional metal (Ni, Cu, Mn, Co, Fe) supported activated carbon was used as catalysts. Ni supported activated carbon ( Ni\\/AC) catalyst, which is prepared by the dipping method with an aqueous solution of Ni(NO3)2, shows higher catalytic activity. Activated carbon and Ni\\/AC catalyst were characterized by

Xukai Li; Ruihuan Huang; Qiuyun Zhang; Wenqing Yang; Laisheng Li

2010-01-01

199

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

SciTech Connect

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

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

1985-01-01

200

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

PubMed

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

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

201

The Washing of Fish: A Literature Assessment.  

National Technical Information Service (NTIS)

In the simple procedure of washing of fish, ample evidence has been revealed that practically no evaluation of equipment efficiency has ever been demonstrated. Major fishing countries indicate most fish washing equipment is of local design and constructio...

F. A. Ramey J. A. Taylor F. B. Thomas

1979-01-01

202

Soil washing and radioactive contamination  

SciTech Connect

Soil washing, a technique combining both physical and chemical processes to produce significant volume reduction of contaminated soils, is widely regarded as a panacea for the huge inventory of contaminated soils in the DOE Complex. While the technology has been demonstrated for organics and to some extent for metals, review of the publications available on the practical applications to radioactive sites, indicates that most volume reduction is a product of unique circumstances such as screening or floating out non-soil materials containing most of the contaminants, or leaching contaminants (uranium or TRU) that exist as anionic complexes (Grant, 1991) which are not held by the soil cation-exchange-capacity. In either case, the potential for success of the technology is extremely site and contaminant specific. The Environmental Protection Agency`s (EPA) guidance on soil washing treatability studies suggests a 50% reduction of contamination in particles over 2mm as a reasonable cutoff for choosing soil washing for further development (EPA, 1991).

Gombert, D.; Bosley, J.B.

1992-03-20

203

Comparative Study of the Adsorption from Aqueous Solutions and the Desorption of Phenol and Nonylphenol Substrates on Activated Carbons  

Microsoft Academic Search

Adsorption of phenol and nonylphenol from aqueous solutions on microporous activated carbons has been studied. The phenol isotherm changes from L-shaped for surface oxygen group free carbon (I sample) to a two-stepped isotherm for oxidized carbon (IN sample, HNO3 treated) Furthermore, the adsorbed amounts diminish in about 25% on IN carbon. It is proposed that a change in the adsorption

D. M. Nevskaia; A. Guerrero-Ruiz

2001-01-01

204

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

Microsoft Academic Search

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

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

2010-01-01

205

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

206

7 CFR 58.429 - Washing machine.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

207

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

PubMed

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

Salman, J M; Hameed, B H

2009-11-26

208

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

PubMed

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

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

2010-10-19

209

Am/Cm Oxalate Precipitation and Washing Demonstration  

SciTech Connect

The purpose of this report is to discuss the findings of the Am/Cm Oxalate Precipitation and Washing Demonstration carried out at TNX during December 1995. This demonstration consisted of two steps: oxalate precipitation and precipitate washing. The first step reacted Am/Cm stimulant solution with oxalic acid resulting in the formation of insoluble lanthanide oxalates and soluble metal oxalates. The second step consisted of washing the precipitate with equal volumes of a nitric acid/oxalic acid solution to remove unwanted cations (miscellaneous metals) from the slurry. Quantitative results consist of: the solubility of the metallic impurities and lanthanide oxalates under process conditions, the settling rate of the oxalates, the specific volume of the oxalate precipitate, and the minimum distance the solution transfer jet can be place from the oxalate solids to prevent entrainment. Finally, discussion of how to decrease lanthanide losses is presented in terms of transfer jet location, initial nitric acid concentration, and wash nitric acid concentration. Solubilizing the precipitate and adjusting the nitric acid concentration prior to vitrification were not performed in this demonstration.

Beck, S.B.

1996-06-11

210

Removal of lead (II) ions from aqueous solutions onto activated carbon derived from waste biomass.  

PubMed

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

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

2013-06-18

211

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

PubMed Central

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

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

2013-01-01

212

Washing and caustic leaching of Hanford Tank C-106 sludge  

SciTech Connect

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

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

1996-10-01

213

Luminescence properties of lanthanide(III) ions in concentrated carbonate solution  

Microsoft Academic Search

Luminescence properties of lanthanide(III) ions (Ln = Nd, Sm, Eu, Gd, Tb, Dy and Tm) were investigated by measuring the excitation and emission spectra, and emission lifetimes in H2O and D2O solutions of 3 moll K2CO3, where anionic tetra-carbonate complexes, [Ln(CO3)4] were the predominant species.Electronic transitions of the carbonato complex corresponding to both the excitation and emission spectra were assigned

RYUJI NAGAISHI; TAKAUMI KIMURA; SHYAMA P. SINHA

2003-01-01

214

Kinetics of extraction of alkylpyrocatecholates of europium and transplutonium elements from carbonate solutions  

Microsoft Academic Search

The kinetics of extraction of alkylpyrocatecholates of europium, americium, curium, and californium from solutions containing 0.01-1.5 M potassium carbonate at pH = 10.5-13.2 has been studied. It has been shown that extraction slows down with increase of concentration of the complexing agent and accelerates with rise of pH. The chemical stage limiting the extraction rate seems to proceed on the

A. P. Novikov; T. I. Bukina; Z. K. Karalova; B. F. Myasoedov

1987-01-01

215

Kinetics of the radiation chemical reactions of tervalent and quadrivalent actinides and lanthanides in carbonate solutions  

Microsoft Academic Search

The reactions of the ions of tervalent and quadrivalent actinides and lanthanides with hydrated electrons eaq- and CO3- radicals in concentrated carbonate solutions have been studied by microsecond pulse radiolysis, using spectrophotometric recording of short-lived particles. It is shown that the rate of the reactions of eaq- with carbonato complexes of Ce(IV), Pu(IV), and Np(IV) is controlled by diffusion. The

A. V. Gogolev; V. P. Shilov; A. M. Fedoseev; A. K. Pikaev

1990-01-01

216

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

Microsoft Academic Search

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

Luca Cecchinato; Marco Corradi; Ezio Fornasieri; Lorenzo Zamboni

2005-01-01

217

Adsorption of anionic and cationic dyes on activated carbon from aqueous solutions: Equilibrium and kinetics  

Microsoft Academic Search

Activated carbon was utilized as adsorbent to remove anionic dye, Orange II (OII), and cationic dye, Methylene blue (MB), from aqueous solutions by adsorption. Batch experiments were conducted to study the effects of temperature (30–65°C), initial concentration of adsorbate (300–500mgL?1) and pH (3.0–9.0) on dyes adsorption. Equilibrium adsorption isotherms and kinetics were investigated. The equilibrium experimental data were analyzed by

Araceli Rodríguez; Juan García; Gabriel Ovejero; María Mestanza

2009-01-01

218

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

SciTech Connect

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.

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

1981-04-01

219

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

SciTech Connect

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.

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

1980-06-01

220

Catalytic wet air oxidation of butyric acid solutions using carbon-supported iridium catalysts  

Microsoft Academic Search

Aqueous solutions of butyric acid were treated by catalytic wet air oxidation using carbon-supported iridium catalysts in a stirred reactor. Under the operating conditions of 6.9bar of oxygen partial pressure and 200°C of temperature, conversions up to 52.9% after 2h were obtained depending on the type of catalyst used. The effects of butyric acid initial concentration, loading of catalyst, oxygen

H. T Gomes; J. L Figueiredo; J. L Faria

2002-01-01

221

Filling of Carbon Nanotubes with Compounds in Solution or Melted Phase  

Microsoft Academic Search

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

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

222

Adsorption characteristics of Cu 2+ and Zn 2+ from aqueous solution using carbonized food waste  

Microsoft Academic Search

The aim of the present study was to analytically provide adsorption characteristics of Cu2+ and Zn2+ using carbonized food waste (CFW); more specifically, batch tests were conducted using various concentrations of metal ions,\\u000a contact times, and initial pH levels in an attempt to understand the adsorption removal of heavy metal ions in aqueous solution\\u000a at concentrations ranging between 50 and

Jung-Geun Han; Jong-Young Lee; Ki-Kwon Hong; Jai-Young Lee; Young-Woong Kim; Sun-Mi Hong

2010-01-01

223

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

Microsoft Academic Search

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

Lotfi Mouni; Djoudi Merabet; Abdelkarim Bouzaza; Lazhar Belkhiri

2010-01-01

224

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

Microsoft Academic Search

Electrosorption of ions from aqueous solutions with carbon nanotubes and nanofibers (CNTs-CNFs) composite film electrodes has been demonstrated. The large area CNTs-CNFs film was directly grown on Ni plate by low pressure and low temperature thermal chemical vapor deposition. The CNTs-CNFs electrodes have great advantages such as low cost, easy operation, long-term reproducibility, and integrity of monolithic CNTs-CNFs film and

X. Z. Wang; M. G. Li; Y. W. Chen; R. M. Cheng; S. M. Huang; L. K. Pan; Z. Sun

2006-01-01

225

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

Microsoft Academic Search

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

Choong-Seop Lee; Boris I. Yakobson

2004-01-01

226

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

Microsoft Academic Search

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

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

2010-01-01

227

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

Microsoft Academic Search

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

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

2006-01-01

228

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

SciTech Connect

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

Philip E. Zapp; John W. Van Zee

2002-02-01

229

Effect of iron manganese oxide solid solutions on selectivity for lower hydrocarbons from carbon monoxide hydrogenation  

SciTech Connect

There exists considerable current interest in the study of catalysts that demonstrate high selectivities for C/sub 2/-C/sub 4/ hydrocarbons from carbon monoxide hydrogenation. In this respect iron manganese matrix catalysts have been well studied by a number of authors since Koelbel initially disclosed that these catalysts could give high yields of C/sub 2/-C/sub 4/ hydrocarbons with a corresponding very low methane selectivity. The mechanism by which the manganese component causes these product distributions is at present poorly understood. Recently Jensen and Massoth have proposed that small iron particles are supported on and electronically promoted by MnO. Although these oxide solid solutions have been identified there have been no reported studies that have investigated the effect of these catalyst components on catalyst selectivity. Oxide solid solutions are known to be important as catalysts of a number of reactions involving carbon monoxide. In this note the authors present their initial findings for the effect of iron manganese oxide solid solutions on catalyst selectivity in carbon monoxide hydrogenation. 24 references.

Hutchings, G.J.; Boeyens, J.C.A.

1986-08-01

230

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

PubMed

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

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

2013-08-30

231

TANK 4 CHARACTERIZATION, SETTLING, AND WASHING STUDIES  

SciTech Connect

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

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

2009-09-29

232

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

PubMed

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

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

2013-01-01

233

Solution-phase synthesis of heteroatom-substituted carbon scaffolds for hydrogen storage.  

PubMed

This paper reports a bottom-up solution-phase process for the preparation of pristine and heteroatom (boron, phosphorus, or nitrogen)-substituted carbon scaffolds that show good surface areas and enhanced hydrogen adsorption capacities and binding energies. The synthesis method involves heating chlorine-containing small organic molecules with metallic sodium at reflux in high-boiling solvents. For heteroatom incorporation, heteroatomic electrophiles are added to the reaction mixture. Under the reaction conditions, micrometer-sized graphitic sheets assembled by 3-5 nm-sized domains of graphene nanoflakes are formed, and when they are heteroatom-substituted, the heteroatoms are uniformly distributed. The substituted carbon scaffolds enriched with heteroatoms (boron ?7.3%, phosphorus ?8.1%, and nitrogen ?28.1%) had surface areas as high as 900 m(2) g(-1) and enhanced reversible hydrogen physisorption capacities relative to pristine carbon scaffolds or common carbonaceous materials. In addition, the binding energies of the substituted carbon scaffolds, as measured by adsorption isotherms, were 8.6, 8.3, and 5.6 kJ mol(-1) for the boron-, phosphorus-, and nitrogen-enriched carbon scaffolds, respectively. PMID:20929219

Jin, Zhong; Sun, Zhengzong; Simpson, Lin J; O'Neill, Kevin J; Parilla, Philip A; Li, Yan; Stadie, Nicholas P; Ahn, Channing C; Kittrell, Carter; Tour, James M

2010-11-01

234

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

PubMed

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

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

2012-06-09

235

Solvent washing of aged PCP contaminated soils  

SciTech Connect

The study evaluates the removal of pentachlorophenol (PCP), a wood preserving agent, from soils that have been contaminated over a period of time. Previously, equal proportions of ethanol and water were found to have the highest PCP removal efficiencies for above ground batch extractions at variouS soil:solvent ratios. In addition, the 50% and 75% ethanol solutions achieved higher removal efficiencies at low solvent throughputs in in-situ soil flushing experiments. In batch extraction tests, the 50% ethanol solution obtained higher PCP removal efficiencies for all soil fractions than the DI water and 100% ethanol solution. The PCP removal efficiency for in-situ above ground soil washing experiments was consistently higher for the 100x140 U.S. mesh soil, regardless of the aging period. In addition, for both in-situ flushing and above ground tests, a lower PCP removal efficiency was obtained for the 20x40 U.S. mesh soil conditioned at 60 C than that for the same soil fraction aged at room temperature. (Copyright (c) 1993 Water Environment Federation).

Khodadoust, A.P.; Wagner, J.A.; Suidan, M.T.; Safferman, S.I.

1993-01-01

236

OPTIMIZATION OF THE WASH-OFF METHOD FOR MEASURING AEROSOL CONCENTRATIONS  

EPA Science Inventory

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

237

Adsorptive removal of dyes from aqueous solution onto carbon nanotubes: a review.  

PubMed

Adsorption is a widely used technique for the separation and removal of pollutants from wastewaters. Carbon nanotubes (CNTs) are emerging as potential adsorbents because of its well defined cylindrical hollow structure, large surface area, high aspect ratios, hydrophobic wall and easily modified surfaces. In this review, dye adsorption capability of CNTs and CNT based composites from aqueous system has been compiled. This article provides the information about the defect, adsorption sites on CNTs and batch adsorption studies under the influence of various operational parameters such as contact time, solution pH, temperatures etc. and deals with mechanisms involved in adsorption of dyes onto CNTs. From the literature reviewed, it is observed that single walled carbon nanotubes (SWCNTs) show higher adsorption capacity than multi walled carbon nanotubes (MWCNTs) and functionalized and CNT composite have better sorption capacity than as grown CNTs. It is evident from the literature that CNT based nanosorbents have shown good potential for the removal of dyes from aqueous solution. However, still more research work should be focused on the development of cost effective, higher efficient and environmental friendly CNT based nanosorbents for their commercial applications. PMID:23579224

Gupta, Vinod Kumar; Kumar, Rajeev; Nayak, Arunima; Saleh, Tawfik A; Barakat, M A

2013-03-25

238

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

PubMed

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

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

2008-03-03

239

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

SciTech Connect

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

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

2009-09-12

240

Effects of Carbon Black on Chain Mobility and Dynamic Mechanical Properties of Solution Polymerized Styrene-Butadiene Rubber  

Microsoft Academic Search

The structure of the bound rubber, the H NMR relaxation time and the cross-link density of the physical network and the glass transition, were studied for solution polymerized styrene-butadiene rubber (SSBR) filled by carbon black, to investigate the effects of carbon black on the chain mobility and dynamic mechanical properties. It was found by H NMR analysis that the rubber

Zhai Jun-Xue; Wang He; Shi Xin-Yan; Zhao Shu-Gao

2011-01-01

241

Analysis of the corrosion of carbon steels in simulated salt repository brines and acid chloride solutions at high temperatures  

Microsoft Academic Search

An analysis of literature data on the corrosion of carbon steels in anoxic brines and acid chloride solutions was performed, and the results were used to assess the expected life of high-level nuclear waste package containers in a salt repository environment. The corrosion rate of carbon steels in moderately acidic aqueous chloride environments obeys an Arrhenius dependence on temperature and

D. R. Diercks; T. F. Kassner

1988-01-01

242

Heterogeneity of activated carbons in adsorption of phenols from aqueous solutions—Comparison of experimental isotherm data and simulation predictions  

Microsoft Academic Search

Surface heterogeneity of activated carbons is usually characterized by adsorption energy distribution (AED) functions which can be estimated from the experimental adsorption isotherms by inverting integral equation. The experimental data of phenol adsorption from aqueous solution on activated carbons prepared from polyacrylonitrile (PAN) and polyethylene terephthalate (PET) have been taken from literature. AED functions for phenol adsorption, generated by application

P. Podkoscielny; K. Nieszporek

2007-01-01

243

Sorption Studies of Methylene Blue Dye in Aqueous Solution by Optimised Carbon Prepared from Guava Seeds (Psidium guajava L.)  

Microsoft Academic Search

The aim of this investigation was to determine the adsorption behavior and kinetics of methylene blue in aqueous solution on activated carbons prepared from guava seeds by way of the two stage activation method in self-generated atmosphere using a muffle furnace. The yield and ash contents of the activated carbons obtained decreased with the increase of activation temperature and time.

Collin G. JOSEPH; Awang BONO; Duduku KRISHNAIAH; Kok Onn SOON

2007-01-01

244

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

Microsoft Academic Search

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

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

2012-01-01

245

Removal of Pb(II) from aqueous solutions using activated carbon from Sea-buckthorn stones by chemical activation  

Microsoft Academic Search

Two series of activated carbon have been prepared by chemical activation of Sea-buckthorn stones with phosphoric acid and zinc chloride for the removal of Pb(II) ions from aqueous solutions. To characterize the adsorptive characteristics of produced active carbon, surface area was calculated using the standard Brunauer–Emmet–Teller method. The microstructures of the resultant activated carbon were observed by scanning electron micrographs.

Sayed Zia Mohammadi; Mohammad Ali Karimi; Daryoush Afzali; Fatemeh Mansouri

2010-01-01

246

Potential benefit of surfactants in a hydrocarbon contaminated soil washing process: fluorescence spectroscopy based assessment.  

PubMed

Soil washing is an ex situ soil remediation treatment process. The purpose of soil washing is to clean the major gravel and sand fractions, concentrating contamination into the fine silt and clay fractions. The addition of surfactants can improve the efficiency of this method. Here we report the use of UV fluorescence spectroscopy to assess the hydrocarbon cleaning process as a rapid and cost effective alternative to gas chromatography. Three wash solutions were tested on a total petroleum hydrocarbon contaminated soil: water, Sea Power 101 (SP101) at 1% (v/v) and Tween80 at 0.5% (w/v). The most effective to wash the gravel and sand was SP101 (54 and 65% improvement over the water only wash, respectively) which moved contamination to the silt fraction (94% of contaminants). Tween80 appeared not to enhance TPH removal efficiency from the gravel and sand fractions but did concentrate TPH in the effluent (95% more than water wash). In addition to TPH removal from gravel and sand, SP101 also showed potential benefit in the soil washing sedimentation process, enhancing sludge/water volume separation by 10% over the water only wash. In summary, fluorescence spectroscopy proved an effective technique to compare TPH removal efficiencies as part of soil washing laboratory based treatability testing. PMID:22503218

Uhmann, Amandine; Aspray, Thomas J

2012-04-03

247

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

SciTech Connect

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

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

1988-07-01

248

Photochemical reactions of Am(V) in bicarbonate-carbonate solutions  

SciTech Connect

The effect of ultraviolet (UV) radiation on Am(V) in sodium carbonate and bicarbonate solutions of pH 9.00 - 11.40 was studied by spectrophotometry. An Am(IV) + Am(VI) mixture was formed at pH 9 to 10; however, the conversion of Am(V) did not exceed 60 - 70%. The reaction rate order with respect to Am(V) was about 1. A quantum yield for the reaction on photolysis with light of {lambda} = 337 nm was estimated at 0.003. The reaction rate and the conversion of Am(V) were decreased with increasing pH. The reaction started with the absorption of a UV quantum by a carbonate complex of Am(V). Its first step was presumably the electron transfer either from a water molecule to Am(V) in the coordination sphere of the excited carbonate complex of Am(V) or between two Am(V) ions in an excimer involving an excited and an unexcited carbonate complex of Am(V).

Yusov, A.B.; Shilov, V.P. [Institute of Physical Chemistry, Moscow (Russian Federation)

1995-12-01

249

ANIONIC EXCHANGE PROCESS FOR THE RECOVERY OF URANIUM AND VANADIUM FROM CARBONATE SOLUTIONS  

DOEpatents

Uranium and vanadium can be economically purified and recovered from non- salt roast carbonate leach liquors by adsorption on a strongly basic anionic exchange resin and subsequent selective elution by one of three alternative methods. Method 1 comprises selectively eluting uranium from the resin with an ammonium sulfate solution followed by eluting vanadium from the resin with either 5 M NaCl, saturated (NH/sub 4/)/sub 2/CO/sub 3/, saturated NaHCO/sub 3/, 1 M NaOH, or saturated S0/sub 2/ solutions. Method II comprises selectively eluting vanadium from the resin with either concentrated NaCl or S0/sub 2/ solutions subsequent to pretreatment of the column with either S0/sub 2/ gas, 1 N HCl, or 0.1 N H/sub 2/8O/sub 4/ followed by eluting uranium from the resin with solutions containing 0.9 M NH/sub 4/Cl or NaCl and 0.1 Cl. Method III comprises flowing the carbonate leac solutlon through a first column of a strongly basic anlonlc exchange resin untll vanadium breakthrough occurs, so that the effluent solution is enriched ln uranium content and the vanadium is chiefly retalned by the resln, absorbing the uranlum from the enriched effluent solution on a second column of a strongly basic anionic exchange resin, pretreating the first column with either 0.1 N HCl, 0.1 H/sub 2/SO/sub 4/, C0/sub 2/ gas, or ammonium sulfate, selectively eluting the vanadlum from the column with saturated S0/sub 2/ solution, pretreatlng the second column with either 0.1 N HCl or S0/sub 2/ gas, selectively eluting residual vanadium from the column with saturated S0/sub 2/ solution, and then eluting the uranium from the column with either 0.1 N HCl and 1 N NaCl orO.l N HCl and 1 N NH/sub 4/Cl.

Bailes, R.H.; Ellis, D.A.; Long, R.S.

1958-12-16

250

Evaluation of detergents for washing fabrics  

Microsoft Academic Search

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

H. Krüssmann

1978-01-01

251

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

SciTech Connect

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.

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

2009-01-15

252

Aqueous 2-amino-2-hydroxymethyl-1,3-propanediol as Potential Carbon Dioxide Capture Solutions  

Microsoft Academic Search

The solubility of carbon dioxide in aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD) was measured for AHPD concentration of 0.15 and 2.5 mass % at 283.15, 298.15 and 313.15 K and for CO2 partial pressures ranging from approximately 5 to 75 kPa. Experimental conditions were chosen in direct connection to specific industrial conditions. The densities of the 0.15, 0.5, 1 and 2.5

D. Le Toumeux; M. Iliuta; F. Larachi; S. Fradette

2006-01-01

253

Kinetics of extraction of alkylpyrocatecholates of europium and transplutonium elements from carbonate solutions  

SciTech Connect

The kinetics of extraction of alkylpyrocatecholates of europium, americium, curium, and californium from solutions containing 0.01-1.5 M potassium carbonate at pH = 10.5-13.2 has been studied. It has been shown that extraction slows down with increase of concentration of the complexing agent and accelerates with rise of pH. The chemical stage limiting the extraction rate seems to proceed on the aqueous phase slide. The conditions of americium(III) and curium(III) separation by extraction chromatography have been determined making use of the kinetic data.

Novikov, A.P.; Bukina, T.I.; Karalova, Z.K.; Myasoedov, B.F.

1987-11-01

254

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

SciTech Connect

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.

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

2012-05-15

255

Electrochemical oxidation of biological molecules at carbon paste electrodes pre-treated in guanine solutions.  

PubMed

Carbon paste electrodes were modified in guanine solutions under an applied potential of 1.1 V and used for electrochemical detection of NADH, NADPH, uric acid and 8-oxoguanine. Detection limits were 3.3, 3.7, 6.6 and 2.0 x 10(-6) M, respectively, with sensitivity of 0.13, 0.10, 0.26 and 0.40 A mol(-1) l cm(-2), respectively. The electrodes showed high reproducibility and absence of surface poisoning effects. Good analytical performance was attributed to the formation of superficial dimer or trimers species of guanine during the modification process. PMID:14623600

da Silva, Robson Pinho; Serrano, Silvia H P

2003-11-24

256

Simultaneous adsorption of hydrogen sulfide and carbon dioxide by an aqueous solution of tricalcium phosphate  

SciTech Connect

In the scrubbing of hydrogen sulfide from a gas in the presence of carbon dioxide, the problem of selective scrubbing often arises-the total extraction of hydrogen sulfide with minimal extraction of CO/sub 2/. Scrubbing of H/sub 2/S from natural gases, gasification gases of different fuels, tertiary treatment of exhaust gases from installations producing sulfur by the Claus method, can be cited as industrial examples of this problem. The use of a selective cyclic method of gas scrubbing is expedient for all of these; one of these methods is the method which uses an aqueous solution of tricalcium phosphate (TCP). Some data on gas scrubbing with a TCP solution are reported, but no generalized dependences for the calculation of the individual stages of the process have been given in these studies. The authors attempt here to fill this gap for the stage of simultaneous adsorption of H/sub 2/S and CO/sub 2/.

Golyand, S.M.; Afanse'ev, Y.M.; Gorshkova, T.A.; Rodionov, A.I.; Shklyar, R.L.

1985-02-01

257

Dispersion of carbon nanotubes in low pH aqueous solutions by means of alumina-coated silica nanoparticles  

Microsoft Academic Search

A novel noncovalent and inorganic method was used to disperse multiwalled carbon nanotubes (MWCNTs) in aqueous solutions through alumina-coated silica (ACS) nanoparticle halos. MWCNTs were directly dispersed into a highly charged ACS nanoparticle aqueous solution without functionalization of their surfaces. The dispersed MWCNTs were characterized by transmission electron microscopy and atomic force microscopy. Raman spectroscopy of MWCNTs prepared from dispersion

Yu-Chen Tsai; Chian-Cheng Chiu; Ming-Chieh Tsai; Jeng-Yue Wu; Tzu-Fan Tseng; Tzong-Ming Wu; Sung-Fu Hsu

2007-01-01

258

Evaluation of the Activated Carbon Prepared of Algae Marine Gracilaria for the Biosorption of Ni (II) from Aqueous Solutions  

Microsoft Academic Search

Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions. In this study, the batch removal of nickel (II) ions from aqueous solution under different experimental conditions using activated carbon prepared of red alga Gracilaria was investigated in this study. The nickel (II) uptake was dependent on initial pH

Akbar Esmaeili; Samira Ghasemi

259

Adsorption of methyl ethyl ketone and trichloroethene from aqueous solutions onto activated carbon fixed-bed adsorbers  

Microsoft Academic Search

This work addresses the adsorption of methyl ethyl ketone (MEK) and trichloroethene (TCE) from aqueous solutions on activated carbon. Results from both equilibrium and fixed-bed adsorption studies in aqueous solutions are given. For TCE, the sorbent is saturated for liquid concentrations near its solubility, which can be explained in terms of a pore volume filling mechanism. MEK adsorbs less than

J. L. Sotelo; M. A. Uguina; J. A. Delgado; L. I. Celemin

2004-01-01

260

Single Wall Carbon Nano Tube Films and Coatings  

Microsoft Academic Search

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

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

2002-01-01

261

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

NASA Astrophysics Data System (ADS)

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

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

1991-06-01

262

Features of electrochemical noise generated during pitting of inhibited A516-70 carbon steel in chloride solutions  

Microsoft Academic Search

The features of electrochemical noise generated during pitting of A516-70 carbon steel in chloride solutions containing Na2CrO4 were investigated. Polarization curves showed that the threshold Cl- concentration in 0.01m Na2CrO4 solution to initiate pitting and the threshold CrO42- concentration in 0.1m NaCl solution to maintain passivation for A516-70 carbon steel were approximately 0.1m and 0.01m, respectively. Noise measurements indicated that

Y. F. Cheng; B. R. Rairdan; J. L. Luo

1998-01-01

263

Microwave-assisted synthesis and characterization of cellulose-carbonated hydroxyapatite nanocomposites in NaOH–urea aqueous solution  

Microsoft Academic Search

We report the microwave-assisted synthesis of the cellulose-carbonated hydroxyapatite (CHA) nanocomposites with CHA nanostructures dispersed in the cellulose matrix by using the cellulose solution, CaCl2, and NaH2PO4. The cellulose solution was previously prepared by the dissolution of microcrystalline cellulose in NaOH–urea aqueous solution. The influences of the heating time and cellulose concentration on the products were also investigated. The X-ray

Ning Jia; Shu-Ming Li; Jie-Fang Zhu; Ming-Guo Ma; Feng Xu; Bo Wang; Run-Cang Sun

2010-01-01

264

Comparative dispersion studies of single-walled carbon nanotubes in aqueous solution.  

PubMed

Single-walled carbon nanotubes (SWCNT) produced by various methods are commercially available but systematic characterization of their dispersion behavior in aqueous solution is rare. Here, we compare the properties of various SWCNT after their dispersion in aqueous solution assisted by DNA oligo. UV-vis-NIR absorbance measurement and atomic force microscopy (AFM) imaging showed marked differences among SWCNT produced from arc-discharge (AD) method, chemical vapor deposition (CVD), and high-pressure carbon monoxide process (HiPCO). To our surprise, the SWCNT produced from AD method showed the highest nanotube purity and the cleanest AFM image, better than HiPCO SWCNT that has been used extensively for biological applications. We also report our systematic studies on optimizing dispersing conditions to maximize SWCNT solubility and remove insoluble materials. We recommend a low power and short time of sonication to disperse SWCNT to preserve their average lengths. These results altogether serve as a future guide for the usage of commercial SWCNT in water-based applications. PMID:21355620

Koh, Byumseok; Park, Jong Bae; Hou, Ximiao; Cheng, Wei

2011-02-28

265

Sorption of lanthanum and erbium from aqueous solution by activated carbon prepared from rice husk.  

PubMed

A biomass agricultural waste material, rice husk (RH) was used for preparation of activated carbon by chemical activation using phosphoric acid. The effect of various factors, e.g. time, pH, initial concentration and temperature of carbon on the adsorption capacity of lanthanum and erbium was quantitatively determined. It was found that the monolayer capacity is 175.4 mg g(-1) for La(III) and 250 mg g(-1) for Er(III). The calculated activation energy of La(III) adsorption on the activated carbon derived from rice husk was equal to 5.84 kJ/mol while it was 3.6 kJ/mol for Er(III), which confirm that the reaction is mainly particle-diffusion-controlled. The kinetics of sorption was described by a model of a pseudo-second-order. External diffusion and intra-particular diffusion were examined. The experimental data show that the external diffusion and intra-particular diffusion are significant in the determination of the sorption rate. Therefore, the developed sorbent is considered as a better replacement technology for removal of La(III) and Er(III) ions from aqueous solution due to its low-cost and good efficiency, fast kinetics, as well as easy to handle and thus no or small amount of secondary sludge is obtained in this application. PMID:20800456

Awwad, N S; Gad, H M H; Ahmad, M I; Aly, H F

2010-08-10

266

Corrosion behavior of titanium alloy Beta-21S coated with diamond like carbon in Hank's solution  

NASA Astrophysics Data System (ADS)

Diamond like carbon (DLC) coatings posses high hardness and low friction coefficient and also biocompatible, hence, they are of interest for enhancing the wear and corrosion resistance of bio-implant materials. Beta stabilized titanium alloys are attractive for biomedical applications because of their high specific strength and low modulus. In this work Beta-21S alloy (Ti-15Mo-3Nb-3Al-0.2Si) was implanted with carbon ions by plasma immersion ion implantation using methane and hydrogen gas mixture followed by DLC deposition by plasma enhanced chemical vapour deposition (PECVD). The implanted layers enabled deposition of adherent diamond-like carbon coatings on the titanium alloy which was otherwise not possible. The corrosion behavior of the treated and untreated samples was investigated through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization studies in simulated body fluid (Hank's solution). XPS, micro Raman and EDAX investigation of the samples showed the formation of a thin oxide layer on the treated samples after corrosion experiments. Corrosion resistance of the DLC coated sample is comparable with that of the untreated samples. Electrochemical impedance data of the substrate and implanted samples were fitted with two time constant equivalent circuits and that of DLC coated samples with two-layer model.

Mohan, L.; Anandan, C.; Grips, V. K. William

2012-06-01

267

A descriptive model for metallic ions adsorption from aqueous solutions onto activated carbons.  

PubMed

The design of adsorber units is mainly dependent on the equilibrium adsorption capacity of the sorbent in the working conditions. At the moment, these data are available in a limited number of experimental conditions and, for the case of activated carbon, there are no predictive models to assess the adsorption capacity as a function of the process parameters. This makes the adsorber design a complex and approximated task. In this work, a model for the description of metallic ions adsorption onto activated carbon is presented. The model starts from an evaluation of ion speciation and it considers the approach of the multi-component Langmuir model to correlate the metal uptake to the ion concentration in solution. The model has been used to analyse available experimental data on the adsorption of As(V), Cd(II), Cr(III) and Cr(VI) ions on activated carbon. A good matching between experimental results and model predictions has been obtained for all the investigated conditions. PMID:19411134

Di Natale, F; Erto, A; Lancia, A; Musmarra, D

2009-03-31

268

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

PubMed

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

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

2012-10-11

269

Ridgecrest Wash Channel, Kern County, California.  

National Technical Information Service (NTIS)

The Ridgecrest Wash Channel project is located in Kern County, California, approximately 1/2 mile westerly and northerly of the city of Ridgecrest. The proposed project is to provide protection against damage caused by flood from Ridgecrest Wash in El Pas...

1971-01-01

270

Sodium wash station operational testing report  

SciTech Connect

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

Knotek, H.M.

1996-10-01

271

WASH SOLVENT REUSE IN PAINT PRODUCTION  

EPA Science Inventory

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

272

Washing withstand voltage tests on station insulators  

Microsoft Academic Search

An investigation was undertaken to determine the cause of flashovers on semi-conducting glaze (also called resistive glaze) station post insulators produced by two different manufacturers, that were experienced by Pacific Gas and Electric Company (PG&E) during pressure washing in the Moss Landing Substation. The insulators that flashed were being struck by over spray water caused during washing of adjacent insulators.

Ron Sharp; Seigo Yokoi; Masahiro Akizuki; Jeff Burnham

2001-01-01

273

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

Microsoft Academic Search

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 NaâCOâ 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

Varlashkin

1985-01-01

274

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

Microsoft Academic Search

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 NaâCOâ 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. The redox properties

Varlashkin

1985-01-01

275

Contaminant resorption during soil washing  

SciTech Connect

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

Gombert, D.

1993-10-01

276

Highly sensitive carbon paste electrode with silver-filled carbon nanotubes as a sensing element for determination of free cyanide ion in aqueous solutions  

Microsoft Academic Search

We report on newly synthesized Ag(I)-filled multiwall carbon nanotubes as a potential sensing element in ion-selective carbon\\u000a paste electrodes for the determination of free cyanide in aqueous solution. The electrode was obtained by entrapping the silver-filled\\u000a nanotubes into a carbon paste and displays a Nernstian response with a slope of 59.8?±?0.3 mV decade?1, a very wide linear range (from 21.0 nM to

Abdollah Yari; Reza Sepahvand

277

A fresh look at preoperative body washing.  

PubMed

National guidelines do not support preoperative body washing to reduce surgical site infections, instead recommending bathing or showering with soap. Yet preoperative body washing continues to be widely used in many hospitals across Europe. This paper suggests that existing trials of preoperative body washing, upon which guidelines are based, are dated and proposes a new investigation of preoperative body washing using modern definitions of surgical site infection with standardised patient follow up, modern surgical techniques and well designed trials. This paper provides a critique of existing guidelines and describes a randomised trial with 60 participants to compare the effect of soap and two antiseptic washing products on colony forming units (CFUs) for up to six hours. Chlorhexidine gluconate and octenidine were significantly more effective than soap in reducing CFUs in the underarm, and chlorhexidine was significantly more effective than soap in reducing CFUs in the groin. PMID:22448182

Tanner, Judith; Gould, Dinah; Jenkins, Philip; Hilliam, Rachel; Mistry, Neetesh; Walsh, Susannah

2012-01-01

278

A fresh look at preoperative body washing  

PubMed Central

National guidelines do not support preoperative body washing to reduce surgical site infections, instead recommending bathing or showering with soap. Yet preoperative body washing continues to be widely used in many hospitals across Europe. This paper suggests that existing trials of preoperative body washing, upon which guidelines are based, are dated and proposes a new investigation of preoperative body washing using modern definitions of surgical site infection with standardised patient follow up, modern surgical techniques and well designed trials. This paper provides a critique of existing guidelines and describes a randomised trial with 60 participants to compare the effect of soap and two antiseptic washing products on colony forming units (CFUs) for up to six hours. Chlorhexidine gluconate and octenidine were significantly more effective than soap in reducing CFUs in the underarm, and chlorhexidine was significantly more effective than soap in reducing CFUs in the groin.

Tanner, Judith; Gould, Dinah; Jenkins, Philip; Hilliam, Rachel; Mistry, Neetesh; Walsh, Susannah

2012-01-01

279

Significantly reinforced composite fibers electrospun from silk fibroin/carbon nanotube aqueous solutions.  

PubMed

Microcomposite fibers of regenerated silk fibroin (RSF) and multiwalled carbon nanotubes (MWNTs) were successfully prepared by an electrospinning process from aqueous solutions. A quiescent blended solution and a three-dimensional Raman image of the composite fibers showed that functionalized MWNTs (F-MWNTs) were well dispersed in the solutions and the RSF fibers, respectively. Raman spectra and wide-angle X-ray diffraction (WAXD) patterns of RSF/F-MWNT electrospun fibers indicated that the composite fibers had higher ?-sheet content and crystallinity than the pure RSF electrospun fibers, respectively. The mechanical properties of the RSF electrospun fibers were improved drastically by incorporating F-MWNTs. Compared with the pure RSF electrospun fibers, the composite fibers with 1.0 wt % F-MWNTs exhibited a 2.8-fold increase in breaking strength, a 4.4-fold increase in Young's modulus, and a 2.1-fold increase in breaking energy. Cytotoxicity test preliminarily demonstrated that the electrospun fiber mats have good biocompatibility for tissue engineering scaffolds. PMID:22881188

Pan, Hui; Zhang, Yaopeng; Hang, Yichun; Shao, Huili; Hu, Xuechao; Xu, Yuemin; Feng, Chao

2012-08-22

280

Removal of chromium ions from [corrected] aqueous solutions by adsorption on activated carbon and char.  

PubMed

Adsorption isotherms of chromium ions in aqueous solution have been experimentally measured on a granular activated carbon (GAC) and on a char of South African coal (CSAC). Experimental results show that the adsorption capacity for the GAC strongly depends on solution pH and salinity, with maximum values around 7mg/g at neutral pH and low salinity levels. On the contrary, the CSAC shows a smaller adsorption capacity, near 0.3mg/g, which slightly decreases by increasing pH and salinity levels. Chromium adsorption mainly depends on the availability of chromium ions in solution and on the occurrence of redox reactions between the surface groups and the Cr(VI) which lead to the formation of Cr(III). The reduction of Cr(VI) and the following sorption of Cr(III) cations appears as the leading mechanism for chromium uptake on the CSAC. A similar behaviour can be observed for the GAC at pH below 3. On the contrary, at pH>7, the multicomponent competitive adsorption of Cr(VI), OH(-) and Cl(-) has to be considered. PMID:17169486

Di Natale, F; Lancia, A; Molino, A; Musmarra, D

2006-11-19

281

Mercury adsorption on granular activated carbon in aqueous solutions containing nitrates and chlorides.  

PubMed

Adsorption is an effective process to remove mercury from polluted waters. In spite of the great number of experiments on this subject, the assessment of the optimal working conditions for industrial processes is suffering the lack of reliable models to describe the main adsorption mechanisms. This paper presents a critical analysis of mercury adsorption on an activated carbon, based on the use of chemical speciation analysis to find out correlations between mercury adsorption and concentration of dissolved species. To support this analysis, a comprehensive experimental study on mercury adsorption at different mercury concentrations, temperatures and pH was carried out in model aqueous solutions. This study pointed out that mercury capture occurs mainly through adsorption of cationic species, the adsorption of anions being significant only for basic pH. Furthermore, it was shown that HgOH(+) and Hg(2+) are captured to a higher extent than HgCl(+), but their adsorption is more sensitive to solution pH. Tests on the effect of temperature in a range from 10 to 55 °C showed a peculiar non-monotonic trend for mercury solution containing chlorides. The chemical speciation and the assumption of adsorption exothermicity allow describing this experimental finding without considering the occurrence of different adsorption mechanisms at different temperature. PMID:21803490

Di Natale, F; Erto, A; Lancia, A; Musmarra, D

2011-07-12

282

The electrochemical and mechanical properties of Ti incorporated amorphous carbon films in Hanks’ solution  

NASA Astrophysics Data System (ADS)

Ti incorporated amorphous carbon (a-C) films with variant Ti contents were prepared by the unbalanced magnetron sputtering process. Scanning electron microscopy, ultraviolet Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy were used to characterize the microstructure of a-C films. The hardness and lubricated tribological properties were assessed using nanoindentation and ball-on-disk tribometer. As the Ti content in a-C films increases from 0 to 15.2 at.%, the sp3 volume fraction, the internal stress and the hardness of the films decreases gradually, while the disorder of sp2 bond increases. The electrochemical tests reveal that the a-C films with lower than 1.5 at.% Ti possess good corrosion resistance in Hanks' solution, while the a-C film with 15.2 at.% Ti is susceptible to crevice corrosion. The reduced friction of the a-C films is due to the sp2 bonded film surface and boundary lubrication of the Hanks' solution. The a-C film with 3.1 at.% Ti exhibits the best wear resistance in Hanks' solution among the studied films.

Hong, Chunfu; Tu, Jiangping; Liu, Dongguang; Li, Ruiling; Gu, Changdong

2010-06-01

283

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

SciTech Connect

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. 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. Californium(III) in bicarbonate-carbonate-hydroxide solution could not be oxidized to Cf(IV) chemically or electrochemically. The oxidation of terbium(III) in K/sub 2/CO/sub 3/-KOH solution was studied. The concentrations of terbium, carbonate, and hydroxide ions for generation and stabilization of Tb(IV) are critical. Redox titrations of Tb(IV) with Fe(CN)/sub 6//sup 4 -/ ion and analysis of Tb(IV) precipitates indicate that the Tb(IV) complex in solution is clustered in nature. 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.

Varlashkin, P.G.

1985-01-01

284

CaO–ZrO 2 Solid Solution: A Highly Stable Catalyst for the Synthesis of Dimethyl Carbonate from Propylene Carbonate and Methanol  

Microsoft Academic Search

CaO–ZrO2 prepared by co-precipitation showed to be a well-performed catalyst for the transesterification of propylene carbonate (PC) and methanol. The characterization by X-ray powered diffraction (XRD) and Raman spectroscopy indicated that CaO was doped into the lattice of ZrO2 to form CaO–ZrO2 solid solution. Such a solid solution was a strong solid base, which was proved by CO2 temperature program

Hui Wang; Mouhua Wang; Ning Zhao; Wei Wei; Yuhan Sun

2005-01-01

285

Genesis Eco Systems, Inc. soil washing process  

SciTech Connect

The Genesis soil washing system is an integrated system of modular design allowing for maximum material handling capabilities, with optimized use of space for site mobility. The Surfactant Activated Bio-enhanced Remediation Equipment-Generation 1 (SABRE-1, Patent Applied For) modification was developed specifically for removing petroleum byproducts from contaminated soils. Scientifically formulated surfactants, introduced by high pressure spray nozzles, displace the contaminant from the surface of the soil particles into the process solution. Once the contaminant is dispersed into the liquid fraction of the process, it is either mechanically removed, chemically oxidized, or biologically oxidized. The contaminated process water is pumped through the Genesis Biosep (Patent Applied For) filtration system where the fines portion is flocculated, and the contaminant-rich liquid portion is combined with an activated mixture of nutrients and carefully selected bacteria to decompose the hydrocarbon fraction. The treated soil and dewatered fines are transferred to a bermed stockpile where bioremediation continues during drying. The process water is reclaimed, filtered, and recycled within the system.

Cena, R.J.

1994-10-11

286

Sodium carbonate poisoning  

MedlinePLUS

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

287

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

Microsoft Academic Search

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

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

1998-01-01

288

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

SciTech Connect

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.

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

1987-09-01

289

The electrochemical study of promethazine hydrochloride in aqueous solution at glassy carbon electrode  

NASA Astrophysics Data System (ADS)

The electrochemical oxidation of promethazine hydrochloride (PMT) was studied on glassy carbon electrode (GCE) whose surface area (6.0 x 10 -3 cm2) was determined electrochemically. The reference electrode was a commercial calomel electrode and the counter electrode was a wound platinum wire. The electrochemical reaction was conducted at room temperature in a one-electrochemical cell using an electrochemical analyzer supplied by Cypress Systems. The important electrochemical parameters such as the redox potential, Eo, the half-wave potential, E 1/2, the diffusion coefficient, D, the number of electrons transferred in the reaction, n, the electron transfer coefficient, alpha, and the heterogeneous rate constant, ks, were determined in a solution of 4.0 x 10 -3 M. These parameters were used in formulating a plausible reaction mechanism of this compound in an aqueous solution. The effect of different surfactants on its stability was also studied. The results of the obtained data indicate that: (1) The electrochemical parameters obtained for this compound were: Eo = 0.60V, E 1/2 = 0.67V, D = 3.9 x 10-5 cm2/s, n = 1mole, alpha = 0.33, ks = 2.45 x 10-4; (2) The peak potential was observed at about 0.60--0.80 V and was linearly dependent on the concentration; (3) The observed current intensity which was determined as a function of the voltammetric scan rate, was seen to be linearly related to the square root of the scan rate; (4) The observed peak potential and the peak current were influenced by the pH of the solution; (5) The stability of PMT in different surfactant (cationic, anionic and non-ionic) shows a decrease when compared to the control solution over twenty days. During this period, it was observed that the anionic and the non-ionic surfactants were more effective stabilizers than the cationic surfactants.

Tambe Takaw, Robert

290

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

NASA Astrophysics Data System (ADS)

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.

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

2010-01-01

291

The influence of preparation methods and surface properties of activated carbons on Cr(III) adsorption from aqueous solutions  

Microsoft Academic Search

Activated carbons were prepared from eucalyptus wood, by using three different “physical” activating methods: air and CO2 partial gasification of wood char (2 hr, 400°C and 800°C, respectively), and direct CO2 partial gasification of wood sawdust. The three activated carbons were then oxidized with HNO3 for increasing the surface concentration of oxygenated functions, and Cr(III) aqueous solution adsorption isotherms were determined

P. Milich; F. Möller; J. Píriz; G. Vivó; N. Tancredi

2002-01-01

292

A chemical study of apatites prepared by hydrolysis of amorphous calcium phosphates in carbonate-containing aqueous solutions  

Microsoft Academic Search

The Ca\\/P molar ratio, % CO32?, and % HPO42? was determined for a number of apatites prepared by the hydrolysis of amorphous calcium phosphate in the presence of solution carbonate. The Ca\\/P molar ratio for each apatite was significantly higher than for the corresponding amorphous precursor. The change in carbonate content was slight but the HPO42? level in these apatites,

D. J. Greenfield; J. D. Termine; E. D. Eanes

1974-01-01

293

Kinetics of catalytic oxidation of sulfide in aqueous solutions on activated carbon and slime of green lye  

SciTech Connect

The kinetics of heterogeneous catalytic oxidation of sulfide ion in alkali solutions by dissolved oxygen with activated carbon and the carbon component of the slime of green lye (the waste of paper and pulp production) as the catalysts has been studied experimentally. The apparent and actual rate constants of the oxidation are measured within the framework of the model of the first order reaction under diffusive limitations.

Yakovlev, V.A.; Andreev, S.B. [St. Petersburg Technological Institute (Russian Federation)

1993-12-20

294

Emulgin as an Inhibitor of Corrosion and Hydrogenation of Carbon Steel in Weakly Acidic H2S-Containing Solutions  

Microsoft Academic Search

The protection effect of emulgin (a technological mixture of some primary and secondary aliphatic amines) in concentrations of 0.078 to 0.625 mmol\\/l from acid, carbon dioxide, and hydrogen sulfide corrosion and hydrogenation of carbon steel St3 was studied. In a 0.005–0.05 M solution of HCl saturated with hydrogen sulfide, the protective value was 97%, no local damage being observed. At

V. I. Vigdorovich; S. E. Sinyutina; L. V. Chivileva

2000-01-01

295

Production of dissolved organic carbon and low-molecular weight organic acids in soil solution driven by recent tree photosynthate  

Microsoft Academic Search

Dissolved organic carbon (DOC) is an important component in the terrestrial carbon cycle. Yet, the relative importance of\\u000a different inputs of DOC to the soil solution remains uncertain. Here, we used a large-scale forest girdling experiment to\\u000a examine how the supply of recent photosynthate to tree roots and their mycorrhizal fungi affects DOC, in particular low-molecular\\u000a weight organic acids (LMWOA).

Reiner Giesler; Mona N. Högberg; Bjarne W. Strobel; Andreas Richter; Anders Nordgren; Peter Högberg

2007-01-01

296

Ultrasonic Measurement of Interface Positions during the Solidification of AN Aqueous Sodium Carbonate Solution around a Vertical Cylinder  

Microsoft Academic Search

An experimental investigation is presented concerning the solidification of an aqueous sodium carbonate solution around a vertical cylinder. The liquid-mushy and mushy-solid interface locations are determined by the pulse-echo ultrasonic measurement technique. Four concentrations, 10, 15, 20, and 25% mass fractions of sodium carbonate, are tested with the vertical cylinder at -20°C. Ultrasonically measured interface locations are compared with visual

M. W. McDonough; A. Faghri

1993-01-01

297

Removal of cationic dyes from aqueous solution using magnetic multi-wall carbon nanotube nanocomposite as adsorbent  

Microsoft Academic Search

A magnetic multi-wall carbon nanotube (MMWCNT) nanocomposite was synthesized and was used as an adsorbent for removal of cationic dyes from aqueous solutions. The MMWCNT nanocomposite was composed of commercial multi-wall carbon nanotubes and iron oxide nanoparticles. The properties of this magnetic adsorbent were characterized by scanning electron microscopy, X-ray diffraction and BET surface area measurements. Adsorption characteristics of the

Ji-Lai Gong; Bin Wang; Guang-Ming Zeng; Chun-Ping Yang; Cheng-Gang Niu; Qiu-Ya Niu; Wen-Jin Zhou; Yi Liang

2009-01-01

298

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

NASA Astrophysics Data System (ADS)

The linearly increasing stress test (LIST) was used to study the stress corrosion cracking (SCC) behavior of a range of pipeline steels in carbonate-bicarbonate solution under stress rate control at different applied potentials. Stress corrosion cracking, at potentials below -800 mV(SCE), was attributed to hydrogen embrittlement. Stress corrosion cracking, in the potential range from about-700 to -500 mV(SCE), was attributed to an anodic dissolution mechanism. In the anodic potential region, the SCC initiation stress was larger than the yield stress and was associated with significant plastic deformation at the cracking site. The relative SCC initiation resistance decreased with in-creasing yield strength. In the cathodic potential region, the SCC initiation stress was smaller than the yield stress of steel; it was approximately equal to the stress at 0.1 pct strain (@#@ ?0.1pct) for all the steels. The original surface was more susceptible to SCC initiation than the polished surface.

Wang, Z. F.; Atrens, A.

1996-09-01

299

Thermally and Environmentally Stable Carrier Doping Using a Solution Method in Carbon Nanotube Films  

NASA Astrophysics Data System (ADS)

In the present paper, we report the thermal stability of a single-walled carbon nanotube (SWCNT) film that was doped using tetrafluorotetracyano-p-quinodimethane (F4TCNQ). The SWCNTs were doped using a vapor method and a solution method, and their thermostabilities were characterized using a gas chromatography/mass spectrometer (GC/MS) and resistance measurements. These measurements clearly demonstrated the high thermal stability of F4TCNQ and the strong charge-transfer interaction between the SWCNTs and the dopants. As a result, we successfully observed an excellent long-term (longer than 500 h) thermal resistance up to 150 °C, which is a sufficient level of stability for the practical use of this dopant.

Sasaki, Yorihiko; Okimoto, Haruya; Yoshida, Kenji; Ono, Yasuichi; Iwasa, Yoshihiro; Takenobu, Taishi

2011-08-01

300

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

SciTech Connect

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

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

2006-07-31

301

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

NASA Astrophysics Data System (ADS)

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

Tokuno, Takehiro; Nogi, Masaya; Jiu, Jinting; Suganuma, Katsuaki

2012-05-01

302

A solution processed top emission OLED with transparent carbon nanotube electrodes.  

PubMed

Top emission organic light emitting diodes (OLEDs) with carbon nanotubes (CNTs) as top electrodes were fabricated and characterized. Devices were fabricated on glass substrates with evaporated bottom Al/LiF cathodes, a spin coated organic emissive layer and a PEDOT-PSS hole injection layer. Transparent thin CNT films were deposited on top of the emission layer to form the anode by micro-contact printing with a polydimethylsiloxane stamp. A very good device performance was obtained, with a peak luminance of 3588 cd m(-2) and a maximum current efficiency of 1.24 cd A(-1). This work shows the possibility of using CNTs as transparent electrodes to replace ITO in organic semiconductor devices. Furthermore, the top emission nature of such devices offers a broader range of applications of CNTs on any type of substrate. By combining with solution processed organic materials, it is anticipated that lower cost fabrication will be possible through roll-to-roll manufacture. PMID:20208120

Chien, Yu-Mo; Lefevre, Florent; Shih, Ishiang; Izquierdo, Ricardo

2010-03-08

303

User-oriented batch reactor solutions to the homogeneous surface diffusion model for different activated carbon dosages.  

PubMed

This paper presents a simplified approach and user-oriented solutions to the homogeneous surface diffusion model (HSDM) equations for determining the surface diffusivity using a batch reactor system. Once the surface diffusivity is known, this model could also be used to estimate the performance of activated carbon (AC) applications as a function of contact time. In addition, fixed-bed performance can be predicted using the user-oriented solutions to the HSDM for fixed beds. The step-by-step procedure for determining surface diffusion coefficients of an activated carbon adsorber, which was initially developed by Hand, Crittenden and Thacker in 1983 for a carbon dose where C(equilibrium)/C(0)=0.5, is modified to allow calculations for different carbon dosages. This modification provides solutions to the HSDM equations for different activated carbon dosages. The solutions to the HSDM framework are provided as simplified algebraic equations suitable for quick and easy estimations of D(S). The excel spread sheet is provided in the supplemental information and a detailed example is discussed. PMID:19249812

Zhang, Qiong; Crittenden, John; Hristovski, Kiril; Hand, David; Westerhoff, Paul

2009-02-06

304

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

PubMed

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

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

2012-01-01

305

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

PubMed

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 first electron proceeds irreversibly and determines the overall rate of the electrode process. This stage is accompanied by the generation of an unstable phenoxyl radical in position 4 of the aromatic ring. The second stage of the electrode reaction produces substituted orto-quinone as the final product of the electrode process of DOPAC. DOPAC exhibits more antioxidative power than synthetic BHT and can be useful in food protection against reactive oxygen species. The results presented can help to explain biochemical and antioxidative properties of DOPAC in a living cell and can be useful in determination of this compound in real samples. PMID:20004625

Michalkiewicz, Slawomir; Skorupa, Agata

2009-12-03

306

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 ...

307

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

SciTech Connect

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.

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

1998-11-01

308

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

PubMed

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

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

2002-08-01

309

Waste washing pre-treatment of municipal and special waste.  

PubMed

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

Cossu, Raffaello; Lai, Tiziana; Pivnenko, Kostyantyn

2011-09-12

310

The electrochromic behavior of indium tin oxide in propylene carbonate solutions  

SciTech Connect

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.

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

1998-07-01

311

Effects of Substitutional Solute Accumulation at ?/? Boundaries on the Growth of Ferrite in Low Carbon Steels  

NASA Astrophysics Data System (ADS)

The growth of proeutectoid ferrite in Fe-C-X alloys containing ˜3 at. pct X, where X is Mn, Ni, Cr, and Si, is re-examined in terms of solute drag using the Hillert Sundman theory. The differences of measured growth rates from those calculated under paraequilibrium (PE) reported previously were accounted for taking into account not only the binding energy of substitutional solute with the boundary, but also the transformation temperature of the alloy. The ferrite growth in quaternary Fe-C-Mn-Si alloys was modeled using the stationary-interface approximation for the matrix of finite grain size. The principal features of growth in these alloys, i.e., initial fast unpartitioned growth and subsequent slow partitioned growth with a high level of carbon supersaturation in austenite, were reproduced incorporating cosegregation of Mn and Si at the boundary. Thus, a strong Mn-Si interaction is likely to enhance accumulation of these elements at the boundary and yield the growth behavior that resembles the growth stasis in Fe-C-Mo alloys.

Guo, H.; Enomoto, M.

2007-06-01

312

Enhanced separation of Compound Xueshuantong capsule using functionalized carbon nanotubes with cationic surfactant solutions in MEEKC.  

PubMed

A novel additive of multi-walled carbon nanotubes (MWNTs) dispersed with cationic surfactants or mixed cationic/anionic surfactants was used for MEEKC separation of eight phenolic compounds, four glycosides, and one phenanthraquinone. In this context, several parameters affecting MEEKC separation were studied, including the dispersion agents of MWNTs, MWNTs content, oil type, SDS concentration, and the type and concentration of cosurfactant. Compared with conventional MEEKC, the addition of all types of MWNTs dispersions using single or mixed cationic surfactant solutions in running buffers was especially useful for improving the separation of solutes tested, as they influenced the partitioning between the oil droplets and aqueous phase due to the exceptional electrical properties and large surface areas of MWNTs. Use of cationic surfactant-coated MWNTs (6.4 ?g/mL) as the additive in a microemulsion buffer (0.5% octanol, 2.8% SDS, 5.8% isopropanol, and 5 mM borate buffer) yielded complete resolution of 13 analytes. The proposed method has been successfully applied for the detection and quantification of the studied compounds in a complex matrix sample (Compound Xueshuantong capsule). PMID:23161282

Cao, Jun; Li, Ping; Chen, Jue; Tan, Ting; Dai, Han-Bin

2012-12-18

313

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

PubMed

Degradation of 29 dyes by means of an activated carbon fiber (ACF) electrode electrolysis system was performed successfully. Almost all dye solutions tested were decolorized effectively in this ACF electrolysis process. Internal relationships between treatment mechanisms and chemical composition of the dye have been discussed in this paper. Generally, it is shown that higher solubility leads to greater degradation in the process. Dyes with many -SO3-, COO-, -SO2NH2, -OH, hydrophilic groups, and azo linkages are susceptible to reduction. However, dyes with many -C=O, -NH-and aromatic groups, and hydrophobic groups, tend to be adsorbed. For dyes with -SO3-, COOH and -OH groups, if their molecules linearly spread in solution and have a significant tendency to form colloids by hydrogenous bonding, they also tend to be adsorbed and flocculated. Typical dynamic electrolysis of dye Acid Red B, Vat Blue BO and Disperse Red E-4B shows how the two major mechanisms, degradation and adsorption, act differently during treatment. Reduction occurs evenly during treatment. During the dominant adsorption process, after certain amount of iron is generated, colloid precipitation occurs and TOC and color are rapidly removed. PMID:11376888

Shen, Z; Wang, W; Jia, J; Ye, J; Feng, X; Peng, A

2001-06-01

314

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

SciTech Connect

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.

Varlashkin, P.G.

1985-03-01

315

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

Microsoft Academic Search

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

M Abdallah; M. M El-Naggar

2001-01-01

316

Sorption of Zn(II), Cu(II), Fe(III) on carbon adsorbents from manganese sulfate solutions  

Microsoft Academic Search

Sorption of Zn2+, Cu2+, Fe3+\\/Fe2+ on carbon adsorbents under static (batch) and dynamic (columns) conditions from model and industrial MnSO4 solutions has been studied. The industrial solutions were obtained by reducing acidic leaching of manganese and pyrite concentrates. The initial manganese concentration was ?35 mmol\\/l and concentration of Zn2+, Cu2+, Fe3+ ions was ?0.2 mmol\\/l. It was found out that

O. N Kononova; A. G Kholmogorov; A. N Lukianov; S. V Kachin; G. L Pashkov; Y. S Kononov

2001-01-01

317

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

NASA Astrophysics Data System (ADS)

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

Liang, Chenghao; Huang, Naibao

2008-12-01

318

Gaseous Polymer Solutions: Solubilities of Polydimethylsiloxane and Polypropylene in Carbon Dioxide and Viscosities of Polydimethylsiloxane in Carbon Dioxide.  

National Technical Information Service (NTIS)

Polydimethylsiloxane is soluble in carbon dioxide in the weight fraction PMDS approx. 0.026 to approx. 0.33, pressure approx. 80 to approx. 450 atm, and 35 to 80C temperature region. Polypropylene is soluble in carbon dioxide in the weight fraction PP app...

J. L. Lundberg M. E. Sikorski

1983-01-01

319

Nanoporous carbon synthesized from sol–gel template for adsorbing gibberellic acid in aqueous solution  

Microsoft Academic Search

A novel method, based on dynamic carbonization and silica template formed by sol–gel, was developed to prepare nanoporous carbon materials with tailored pore structures. The effects of the sol–gel reaction and carbonization process on the final nanoporous carbon product were investigated by pore features such as specific surface area, the total pore volume, and pore size distribution, which were systemically

Jin Li; Jin-Tong Xia; Hong-Bo Liu; Jiao-Lian He; Jun-Hua Zhang

2011-01-01

320

Removal of Acid Violet 17 from Aqueous Solutions by Adsorption onto Activated Carbon Prepared from Pistachio Nut Shell  

Microsoft Academic Search

Adsorbents prepared from pistachio nut shell, an agricultural waste biomass, were successfully used to remove Acid Violet 17 from an aqueous solution. The activated carbons PNS1, PNS2, and PNS3 were characterized by scanning electron microscope (SEM), Fourier Transform – Infra Red spectroscopy (FTIR) and (BET). The effect of pH, adsorbent dosage, and temperature on dye removal was studied. Maximum color

P. Vijayalakshmi; V. Sathya Selva Bala; K. V. Thiruvengadaravi; P. Panneerselvam; M. Palanichamy; S. Sivanesan

2010-01-01

321

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

Microsoft Academic Search

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

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

2012-01-01

322

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

Microsoft Academic Search

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

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

2010-01-01

323

Attenuated total reflectance infrared spectroelectrochemistry at a carbon particle electrode; unmediated redox control of a [NiFe]-hydrogenase solution.  

PubMed

We report a versatile infrared spectroscopic method for studying redox chemistry of metalloproteins, and demonstrate for the first time electrochemically-induced changes to the active site of the regulatory [NiFe]-hydrogenase from Ralstonia eutropha. A carbon particle network working electrode allows control over a wide potential window without the need for solution mediators. PMID:23552374

Healy, Adam J; Ash, Philip A; Lenz, Oliver; Vincent, Kylie A

2013-05-21

324

Dissolved organic carbon in precipitation, throughfall, stemflow, soil solution, and stream water at the Guandaushi subtropical forest in Taiwan  

Microsoft Academic Search

The concentration and flux of dissolved organic carbon (DOC) were measured in precipitation, throughfall, stemflow, soil solution, and stream water for three types of subtropical forest stands, a Chinese fir (Cunninghamia lanceolata) plantation, a secondary hardwood, and a natural hardwood stand in Guandaushi forest in central Taiwan from January 1998 to December 1998. The mean DOC concentration in precipitation was

Chiung Pin Liu; Bor Hung Sheu

2003-01-01

325

Microwave assisted preparation of efficient activated carbon from grapevine rhytidome for the removal of methyl violet from aqueous solution  

Microsoft Academic Search

Grapevine rhytidome (the outer layer of bark on trunk), as an abundant and low-cost precursor, was used to prepare granular activated carbon with high surface area for the removal of methyl violet from aqueous solution. Microwave heating source was used to reduce the treatment time and energy consumption. To optimize the preparation, the effects of the different parameters, such as

Mahtab Hejazifar; Saeid Azizian; Hassan Sarikhani; Qiang Li; Dongyuan Zhao

2011-01-01

326

Activated carbon obtained by pyrolysis of potato peel for the removal of heavy metal copper (II) from aqueous solutions  

Microsoft Academic Search

Activated carbons (ACs) were prepared by pyrolysis of potato peel in presence of zinc chloride (chemical activities). Potato peel from Colombian cultives were impregnated with aqueous solutions of ZnCl2 following a variant of the incipient wetness method. Different concentrations were used to produce impregnation ratios of 40, 70, 110 and 160wt.%. Activation was carried out under argon flow by heating

J. C. Moreno-Piraján; L. Giraldo

2011-01-01

327

Removal of plant poisoning dyes by adsorption on Tomato Plant Root and green carbon from aqueous solution and its recovery  

Microsoft Academic Search

The organic dyes directly pollute the soil, water, plants and all living systems in the environment. The dyes like cationic Methylene blue (MB) and Crystal violet (CV) adsorption has been studied on Tomato Plant Root powder (TPR) and green carbon from aqueous solution for identifying the plant poisoning nature of cationic dyes. TPR powder is a cellulose material and green

Chellapandian Kannan; Natesan Buvaneswari; Thayumanavan Palvannan

2009-01-01

328

Thickness effects of a carbon-supported platinum catalyst layer on the electrochemical reduction of oxygen in sulfuric acid solution  

Microsoft Academic Search

The influence of the thickness of a carbon-supported platinum catalyst layer on the oxygen reduction reaction (orr) has been studied in sulfuric acid solution by means of a thin-film rotating disk electrode. Pronounced changes in the Pt utilization, electrode activity and the orr kinetics have been observed upon varying the catalyst layer thickness. The thicker film electrode exhibits a higher

Junhua Jiang; Baolian Yi

2005-01-01

329

Influence of pitting and iron oxide formation during corrosion of carbon steel in unbuffered NaCl solutions  

Microsoft Academic Search

The corrosion evolution over time of a carbon steel rotating disk immersed in aerated NaCl solutions was analyzed using a superposition model. Using this approach, partial polarization curves for iron oxidation and oxygen reduction were synthesized from experimental current–potential data at different corrosion time in order to determine the kinetics parameters, corrosion potential and current density of the underlying anodic

Luis Cáceres; Tomás Vargas; Leandro Herrera

2009-01-01

330

Interfacial area and mass transfer in carbon dioxide absorption in TEA aqueous solutions in a bubble column reactor  

Microsoft Academic Search

The hydrodynamic behaviour and mass transfer of carbon dioxide removal process by aqueous solutions of triethanolamine (TEA) are analysed. The experiments were made in a bubble column reactor (BCR) as gas–liquid contactor. The interfacial area and mass transfer coefficient were calculated by using a photographic method based on the bubble diameter determination. The influence of operation conditions, liquid phase nature

M. Dolores La Rubia; Alicia García-Abuín; Diego Gómez-Díaz; José M. Navaza

2010-01-01

331

DISSOLUTION OF PLUTONIUM CONTAINING CARRIER PRECIPITATE BY CARBONATE METATHESIS AND SEPARATION OF SULFIDE IMPURITIES THEREFROM BY SULFIDE PRECIPITATION  

DOEpatents

A process is described for recovering plutonium from foreign products wherein a carrier precipitate of lanthanum fluoride containing plutonium is obtained and includes the steps of dissolving the carrier precipitate in an alkali metal carbonate solution, adding a soluble sulfide, separating the sulfide precipitate, adding an alkali metal hydroxide, separating the resulting precipitate, washing, and dissolving in a strong acid.

Duffield, R.B.

1959-07-14

332

[Influence of operating parameters on surfactant-enhanced washing to remedy PAHs contaminated soil].  

PubMed

Liquid/solid ratio (L/S) is an important influencing factor on contaminant removal in soil washing. The impact of different liquid/solid ratio on washing performance with Triton X-100 and Tween-80 was studied respectively and evaluated through removal ratio (R), surfactant adsorption loss ratio (V(s)) and solubilization percent (SP). The results presented that the performance of washing to remove PAHs in soil was significantly affected by liquid/solid ratio. PAH removal ratio was gradually increased with liquid/solid ratio increasing in the non-linear form, R presented nonlinear increasing until L/S = 10: 1. Surfactant adsorption loss ratio was insignificantly decreased. At the same liquid/solid ratio, removal ratio of Triton X-100 is more than that of Tween-80. V(s) presented drastic decreasing until L/S = 10: 1, adsorption loss ratio of Triton X-100 is less than that of Tween-80. SP was decreased after maximum value is occurred at L/S = 10: 1. Combining with R, V(s) and SP, L/S = 10:1 should be an effective washing point, Triton X-100 should be a reasonable washing solution and SP is a more effective index to chose liquid/solid ratio. When Triton X-100 is as washing solution and L/S = 10: 1, R, V(s) and SP is 74.7%, 23.47% and 48.99%, respectively. PMID:22624395

Wu, Wei; Jiang, Lin; Chen, Jia-Jun; Peng, Sheng

2012-03-01

333

Comparison of the Responses of Corn Root Tissue to Fusicoccin and Washing 1  

PubMed Central

A comparison has been made of the effects of fusicoccin with those of washing on segments of corn (Zea mays L.) root tissue. Both fusicoccin and washing caused increases in K+(86Rb) influx, net H+ efflux, and electrogenic cell membrane potential, but with no effect on respiration rate. The similarity was most evident with fresh tissue during the initial phases of washing, prior to the developmental changes which augment the anion and general solute transport rates of the tissue. After the development of enhanced transport capacity the proportional response to fusicoccin was much diminished. It is suggested that the fusicoccin-like response to washing may be a manifestation of recovery from injury.

Gronewald, John W.; Cheeseman, John M.; Hanson, John B.

1979-01-01

334

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

PubMed

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

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

2007-04-26

335

Cr(VI) removal from aqueous solution by activated carbon coated with quaternized poly(4-vinylpyridine)  

SciTech Connect

A composite sorbent (GAC-QPVP) was prepared by coating poly(4-vinylpyridine) onto a commercial activated carbon (F400, Calgon), followed by cross-linking and quaternization processes. The sorbent was characterized by scanning electron microscopy, point of zero charge measurement, and BET analysis. Batch experiments with variable pH, ionic strength, and concentrations of Cr(VI), sorbent, and competing anions were conducted to evaluate the selective sorption of Cr(VI) from aqueous solutions. The equilibrium uptake of Cr(VI) increased with decreasing pH, decreasing ionic strength, and increasing sorbent concentration. The estimated maximum equilibrium uptake of chromium was 53.7 mg/g at pH = 2.25, 30.7 mg/g at pH = 3.65, and 18.9 mg/g at pH = 6.03, which were much higher than the maximum capacity of 3.5 mg/g for the PVP-coated silica gel at pH = 5.0 (optimum pH for Cr(VI) sorption) reported in the literature [13]. The effect of phosphate, sulfate, and nitrate was minor on the selective sorption of Cr(VI) and only when above a specific molar ratio. An ion exchange model that was linked with aqueous speciation chemistry reasonably well describe Cr(VI) sorption as a function of pH, ionic strength, and Cr(VI) concentration. Model simulations suggested that sorbed Cr(VI) was partially reduced to Cr(III) on the sorbent when pH < 4. The presence of Cr(III) on the sorbent was confirmed by the X-ray photoelectron spectroscopic analysis of the reacted sorbent. Overall, the results showed that GAC-QPVP can effectively remove Cr(VI) from aqueous solutions under a wide range of experimental conditions.

Fang, Jun; Gu, Zhimang; Gang, Dianchen; Liu, Chongxuan; Ilton, Eugene S.; Deng, Baolin

2007-06-05

336

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

SciTech Connect

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

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

1995-03-01

337

Deposition of platinum on the outer surface of carbon-encapsulated silver nanoparticles  

Microsoft Academic Search

Investigations of the morphological and phase characteristics of silver nanoparticles encapsulated in amorphous carbon shell (Ag@C) during heating, acid treatment and galvanic replacement reactions were carried out. It was found that upon heating of Ag@C nanoparticles up to 800°C the silver sublimes resulting in the formation of hollow carbon nanocapsules. Washing of Ag@C nanoparticles with nitric or hydrochloric acid solutions

Boris B. Bokhonov

2011-01-01

338

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

SciTech Connect

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

Siegel, D.I.

1992-04-09

339

Inhibiting properties and adsorption of an amine based fatty acid corrosion inhibitor on carbon steel in aqueous carbon dioxide solutions.  

National Technical Information Service (NTIS)

Carbon dioxide corrosion is a major corrosion problem in oil and gas production systems and many organic inhibitors have been tested and used to protect the substrate from corrosion. This thesis studies the mechanism of interaction of the inhibitor molecu...

J. Buchweishaija

1997-01-01

340

An evaluation of two wash procedures for the differentiation of external contamination versus ingestion in the analysis of human hair samples for cocaine.  

PubMed

In order to evaluate the effectiveness of a wash procedure using isopropanol followed by multiple extended phosphate buffer washes as compared with a methanol wash procedure previously reported, a contamination experiment was designed involving the soaking of human head hair in cocaine-contaminated aqueous solutions. Fourteen negative human head hair samples were soaked in a solution of cocaine HCl (1000 ng/mL) at room temperature for 1 h, then rinsed with distilled water and dried at room temperature. Using the extensive wash procedures (15-min isopropanol wash, followed by three 30-min phosphate buffer washes and then two 60-min washes), in no case would any of the samples be reported out as positive at a cut-off of 5 ng cocaine/ 10 mg hair. With the methanol procedure, 8 of the 14 methanol-washed samples exceeded a cut-off of 5 ng/10 mg hair. Extensive washing was shown to be far more effective for removal of external contamination than the methanol wash procedure reported. In all cases, the extensive aqueous wash protocol would allow the differentiation of ingestion versus external contamination, as defined by this soaking experiment. All samples underwent solid-phase extraction and derivatization followed by liquid chromatographic-tandem mass spectrometric analysis. Analysis was performed on a triple quadrupole API 2000 PerkinElmer Sciex mass spectrometer (MS) equipped with an atmospheric pressure ionization source via an ion spray interface. The MS operated in the positive Cl multiple reaction mode. PMID:12423004

Schaffer, Michael I; Wang, Wen-Ling; Irving, John

2002-10-01

341

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

SciTech Connect

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.

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

1998-04-14

342

Washing of waste prior to landfilling.  

PubMed

The main impact produced by landfills is represented by the release of leachate emissions. Waste washing treatment has been investigated to evaluate its efficiency in reducing the waste leaching fraction prior to landfilling. The results of laboratory-scale washing tests applied to several significant residues from integrated management of solid waste are presented in this study, specifically: non-recyclable plastics from source separation, mechanical-biological treated municipal solid waste and a special waste, automotive shredded residues. Results obtained demonstrate that washing treatment contributes towards combating the environmental impacts of raw wastes. Accordingly, a leachate production model was applied, leading to the consideration that the concentrations of chemical oxygen demand (COD) and total Kjeldahl nitrogen (TKN), parameters of fundamental importance in the characterization of landfill leachate, from a landfill containing washed wastes, are comparable to those that would only be reached between 90 and 220years later in the presence of raw wastes. The findings obtained demonstrated that washing of waste may represent an effective means of reducing the leachable fraction resulting in a consequent decrease in landfill emissions. Further studies on pilot scale are needed to assess the potential for full-scale application of this treatment. PMID:22245736

Cossu, Raffaello; Lai, Tiziana

2012-01-15

343

Immersion freezing of birch pollen washing water  

NASA Astrophysics Data System (ADS)

In the present study, the immersion freezing behavior of birch pollen, i.e. its ice nucleating active (INA) macromolecules, was investigated at the Leipzig Aerosol Cloud Interaction Simulator (LACIS). For that, washing water of two different birch pollen samples with different regional origin (Northern birch and Southern birch) were used. The immersion freezing of droplets generated from the pollen washing water was already observed at temperatures higher than -20 °C, for both samples. Main differences between the Northern birch pollen and the Southern birch pollen were obvious in a temperature range, between -18 °C and -24 °C, where the ice fraction increased with decreasing temperature. There, the Northern birch pollen washing water featured two different slopes, with one being steeper and one being similar to the slope of the Southern birch pollen washing water. As we assume single INA macromolecules being the reason for the ice nucleation, we concluded that the Northern birch pollen are able to produce at least two different types of INA macromolecules. We were able to determine the heterogeneous nucleation rates for both INA macromolecule types and so could explain the ice nucleation behavior of both, the Southern and the Northern birch pollen washing water.

Augustin, S.; Hartmann, S.; Pummer, B.; Grothe, H.; Niedermeier, D.; Clauss, T.; Voigtländer, J.; Tomsche, L.; Wex, H.; Stratmann, F.

2012-12-01

344

Technical bases DWPF Late Washing Facility  

SciTech Connect

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.

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

1992-08-10

345

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

SciTech Connect

The linearly increasing stress test (LIST) was used to study the stress corrosion cracking (SCC) behavior of a range of pipeline steels in carbonate-bicarbonate solution under stress rate control at different applied potentials. Stress corrosion cracking, at potentials below {minus}800 mV(SCE), was attributed to hydrogen embrittlement. Stress corrosion cracking, in the potential range from about {minus}700 to {minus}500 mV(SCE), was attributed to an anodic dissolution mechanism. In the anodic potential region, the SCC initiation stress was larger than the yield stress and was associated with significant plastic deformation at the cracking site. The relative SCC initiation resistance decreased with increasing yield strength. In the cathodic potential region, the SCC initiation stress was smaller than the yield stress of steel; it was approximately equal to the stress at 0.1 pct strain ({sigma}{sub 0.1 pct}) for all the steels. The original surface was more susceptible to SCC initiation than the polished surface.

Wang, Z.F.; Atrens, A. [Univ. of Queensland, Brisbane, Queensland (Australia). Dept. of Mining and Metallurgical Engineering

1996-09-01

346

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

PubMed

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

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

2007-08-12

347

Optimization of peroxynitrite-luminol chemiluminescence system for detecting peroxynitrite in cell culture solution exposed to carbon disulphide.  

PubMed

We established a peroxynitrite-luminol chemiluminescence system for detecting peroxynitrite in cell culture solution exposed to carbon disulphide (CS(2)). Three factors, including exposure time to ozone (Factor A), volume of peroxynitrite (ONOO(-)) solution (Factor B) and luminol concentrations (Factor C) at three levels were selected and the combinations were in accordance with orthogonal design L(9) (3(4)). Peroxynitrite was generated from the reaction of ozone and 0.01 mol/L sodium azide (NaN(3)) dissolved in carbonic acid buffer solution (pH 11), and it was reacted with luminol to yield chemiluminescence. The peak value, peak time and kinetic curve of the light emission were observed. The selected combination conditions were 50 s ozone, 800 micro L peroxynitrite and 0.001 mol/L luminol solution. Cell culture solution with CS(2) enhanced the emission intensity of chemiluminescence (F = 8.38, p = 0.018) and shortened the peak time to chemiluminescence (F = 139.00, p = 0.0001). The data demonstrated that this luminol chemiluminescence system is suitable for detecting peroxynitrite in cell culture solutions for evaluating the effect of CS(2) on endothelial cells. PMID:14587075

Chen, Shao L; Jian, Le; Lang, Hui Q

348

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

SciTech Connect

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

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

1995-02-01

349

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

SciTech Connect

Alpha radiation induced formation of hydrogen peroxide in carbonate ?bicarbonate media was followed by 13C NMR using dissolved [233UO2(13CO3)3]4- as the alpha source (Dalpha= 12.1 Gy/hr). Between the pH region between 5.9 and 11.6 hydrogen peroxide causes a varied speciation of the uranyl carbonates that is a function of the uranium, carbonate and the hydrogen peroxide concentrations. It is shown that the speciation of the peroxy carbonates (or other species) formed in solution by titration with hydrogen peroxide are common to those formed by hydrogen peroxide generated by radiolysis. The radiolysis experiment was carried out above pH = 9.96 to minimize the loss of 13CO2 over a 2800 hr period. Radiolytic generation of hydrogen peroxide was followed by formation of a uranyl peroxy carbonate complex and complex formation accelerated for about 1200 hours. Complex formation was observed to terminate at a concentration between 1x10-4 and 5x10-4 M. It is assumed that either a steady state H2O2 production rate was established in solution or that some limiting feature of the experiment was responsible for slowing the yield of product.

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

2006-05-01

350

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

351

Thermodynamics of Cm(III) in Concentrated Salt Solutions: Carbonate Complexation in NaCl Solution at 25°C  

Microsoft Academic Search

The carbonate complexation reactions of Cm(III) were studied by time-resolved laser fluorescence spectroscopy in 0–6 m NaCl at 25°C. The ionic strength dependence of the stepwise formation constants for the carbonato complexes Cm(CO3)n3-2n with n = 1, 2, 3, and 4 is described by modeling the activity coefficients of the Cm(III) species with Pitzer's ion-interaction approach. Based on the present

Th. Fanghänel; Th. Könnecke; H. Weger; P. Paviet-Hartmann; V. Neck; J. I. Kim

1999-01-01

352

Thermodynamically stable, size selective solubilization of carbon nanotubes in aqueous solutions of amphiphilic block copolymers  

Microsoft Academic Search

Two molecular modes of amphiphilic block copolymer-carbon nanotube interactions have been identified in the literature, one involving the adsorption of individual block copolymer molecules on the carbon nanotubes and the other involving the adsorption of multimolecular, spherical micelles. In both cases, the nature of stability imparted to the dispersion of carbon nanotubes in the aqueous medium is kinetic, controlled by

R. Nagarajan; R. Ashton Bradley; Bindu R. Nair

2009-01-01

353

Observation of activated carbon fibres with SEM and AFM correlation with adsorption data in aqueous solution  

Microsoft Academic Search

Activated carbon fibres are new adsorbents, which seem very promising for air or water treatment. In this work, rayon fibres which have been carbonized and activated in the form of woven cloths, are studied by means of two kinds of microscopy: Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The resulting observations show the effect of carbonization and activation

C. Brasquet; B. Rousseau; H. Estrade-Szwarckopf; P. Le Cloirec

2000-01-01

354

Washing methanogenic cells with the liquid fraction from a Mars soil simulant and water mixture.  

PubMed

Certain methanogens have been shown to grow on a Mars soil simulant following a washing procedure using a carbonate buffer. In experiments where liquid fractions from the soil simulant and water mixtures were used in place of the buffer, two out of three of the species demonstrated significantly greater methane production compared to the buffer. PMID:16828907

Ormond, David Ryan; Kral, Timothy A

2006-07-10

355

Prediction of equilibrium solubility of Carbon Dioxide in aqueous 2-amino-2-methyl-1,3-propanediol Solutions  

Microsoft Academic Search

The modified Kent-Eisenberg model was used to predict the solubility of carbon dioxide in aqueous 2-amino-2-methyl-1,3-propanediol\\u000a (AMPD) solutions over a wide range of solvent concentration (10-30 mass %), temperature (30-60 °C), and partial pressure of\\u000a carbon dioxide (5-1,100 kPa). For more accurate prediction, a new set of experimental data of this system was also presented\\u000a and used in model calculation.

Jeom-In Baek; Ji-Ho Yoon; Hee-Moon Eum

2000-01-01

356

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

SciTech Connect

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

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

2000-02-01

357

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

PubMed

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

Nakano, Yumiko; Matsuo, Masaru

2010-02-16

358

A comparative study on the carbon dioxide capture power between 30 wt% 2-amino-2-methyl-1-propanol and 30 wt% methyldiethanol amine aqueous solutions  

Microsoft Academic Search

A comparative study has been performed to compare the 30 wt% of 2-amino-2-methyl-1-propanol (AMP) aqueous solution and 30\\u000a wt% of methyldiethanol amine (MDEA) aqueous solution to capture carbon dioxide contained in the flue gas stream. The equilibrium\\u000a constants for each electrolyte reactions have been used to estimate the carbon dioxide absorption process. Henry’s constants\\u000a for each binary pairs between solute

Byung Don Lee; Dong Min Kim; Jungho Cho; Sang Wook Park

2009-01-01

359

Comparisons of sorbent cost for the removal of Ni2+ from aqueous solution by carbon nanotubes and granular activated carbon.  

PubMed

The reversibility of Ni2+ sorption by NaOCl oxidized single-walled carbon nanotubes (SWCNTs), multiwalled carbon nanotubes (MWCNTs) and granular activated carbon (GAC) was investigated to evaluate their repeated availability performance in water treatment. Under the same conditions, the SWCNTs and MWCNTs possess more Ni2+ sorption capacities and show better reversibility of Ni2+ sorption and less weight loss after being repeated sorption/desorption processes than the GAC, suggesting that they are effective Ni2+ sorbents and can be reused through many cycles of water treatment and regeneration. A statistical analysis on the replacement cost of these sorbents revealed that SWCNTs and MWCNTs can be possibly cost-effective Ni2+ sorbents in water treatment regardless of their high unit cost at the present time. PMID:17618049

Lu, Chungsying; Liu, Chunti; Rao, Gadupudi Purnachadra

2007-06-02

360

Seasonal export of carbon, nitrogen, and major solutes from Alaskan catchments with discontinuous permafrost  

NASA Astrophysics Data System (ADS)

Frequent measurements of stream chemistry during snowmelt and summer storms were used in three watersheds that differ in permafrost coverage (high, 53%; medium, 18%; and low, 4%) to determine the role of water flow paths on the fluxes of carbon, nitrogen, and major solutes from Alaskan catchments. Permafrost was important in the seasonal pattern of stream chemistry as there was a distinct shift in chemistry and flow from winter through snowmelt and into summer in the permafrost-dominated catchment. Furthermore, the active layer above the permafrost was important for the late summer release of NO3- and DOC, suggesting a deeper active layer may increase N and C loss in permafrost-dominated areas. Overall, permafrost constrained water flow to the active layer, resulting in higher DOC but lower dissolved mineral fluxes (Ca2+ Mg2+ K+ Na+) in the high-permafrost watershed than in the watersheds with less permafrost coverage. However, the decline in dissolved mineral fluxes was not linearly related to permafrost coverage across watersheds. The flux of weathering ions may also be explained by total water runoff, since the medium-permafrost watershed, which had the greatest runoff on an areal basis, yielded the greatest loss of all major elements (Ca2+ Mg2+ K+ Na+ SO42- NO3- NH4+ Cl-) except DOC. Despite differences among watersheds in permafrost coverage, hydrologic flow paths, area, and total runoff, all watersheds were net sources of every individual ions or elements (Cl-, PO42-, SO42-, DOC, DON, NO3-, Na+, K+ Mg2+, Ca2+) except NH4+, which was a small fraction of the total N concentration in streams.

Petrone, Kevin C.; Jones, Jeremy B.; Hinzman, Larry D.; Boone, Richard D.

2006-06-01

361

Solid-Solute Phase Equilibria in Aqueous Solution. XI. Aqueous Solubility and Standard Gibbs Energy of Cadmium Carbonate  

Microsoft Academic Search

The solubilities of CdCO3 (otavite) in aqueous NaClO4 solutions have been investigated as a function of ionic strength (0.15 ? I\\/mol-kg?1 ? 5.35, 25°C) and temperature (25°C ? T ? 75°C, I = 1.00 mol-kg?1). A new Chemsage optimization routine was employed to simultaneously evaluate solubility data from this work and other sources, as well as standard electrode potentials determined

Heinz Gamsjäger; Wolfgang Preis; Erich Königsberger; M. Clara Magalhães; Paula Brandão

1999-01-01

362

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

PubMed

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

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

2013-02-22

363

Removal of cationic dyes from aqueous solution using magnetic multi-wall carbon nanotube nanocomposite as adsorbent.  

PubMed

A magnetic multi-wall carbon nanotube (MMWCNT) nanocomposite was synthesized and was used as an adsorbent for removal of cationic dyes from aqueous solutions. The MMWCNT nanocomposite was composed of commercial multi-wall carbon nanotubes and iron oxide nanoparticles. The properties of this magnetic adsorbent were characterized by scanning electron microscopy, X-ray diffraction and BET surface area measurements. Adsorption characteristics of the MMWCNT nanocomposite adsorbent were examined using methylene blue, neutral red and brilliant cresyl blue as adsorbates. Experiments were carried out to investigate adsorption kinetics, adsorption capacity of the adsorbent and the effect of adsorption dosage and solution pH values on the removal of cationic dyes. Kinetic data were well fitted by a pseudo second-order model. Freundlich model was used to study the adsorption isotherms. The prepared MMWCNT adsorbent displayed the main advantage of separation convenience compared to the present adsorption treatment. PMID:18977077

Gong, Ji-Lai; Wang, Bin; Zeng, Guang-Ming; Yang, Chun-Ping; Niu, Cheng-Gang; Niu, Qiu-Ya; Zhou, Wen-Jin; Liang, Yi

2008-09-26

364

A new method for the study of trace element partitioning between calcium carbonate and aqueous solution: A test case for Sr and Ba incorporation into calcite  

Microsoft Academic Search

A new experimental method (evaporation method) for calcium carbonate precipitation in aqueous solution was at- tempted in order to develop a convenient and controllable experimental technique for obtaining precise trace element partition coefficients. Calcite crystals were formed by evaporation of H2O from the aqueous mother solution using a dehumidifier, and the consumed Ca ions were supplied from a refill solution

YASUTAKA TERAKADO; MAMI TANIGUCHI

2006-01-01

365

CHEMICAL ANALYSES OF COMMERCIAL EGG WASH WATER  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wash water was collected from the first (W1) and second (W2) egg washers in series in three different commercial facilities (Plants X, Y and Z) and evaluated for temperature, pH, chlorine, soluble iron (ferrous), total dissolved solids (TDS), total suspended solids (TSS), total Kjeldahl nitrogen (TK...

366

Platelet Activity in Washed Platelet Concentrates  

Microsoft Academic Search

Life-threatening anaphylaxis or febrile nonhemolytic transfusion reactions after transfusion of platelet con- centrates (PCs) is a serious clinical problem caused by the sensitizing of recipients to plasma components, such as immunoglobulin A, or by cytokines. There is a possible indication for washing of PCs in these throm- bocytopenic patients. However, only platelets that show activation after physiological stimulation are use-

Helge Schoenfeld; Manfred Muhm; Ulrich Doepfmer; Aristomenis Exadaktylos; Hartmut Radtke

2004-01-01

367

Rain Induced Pollutant Washing in Urban Areas  

Microsoft Academic Search

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

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

368

What Happens at a Car Wash?  

ERIC Educational Resources Information Center

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

Gallick, Barbara; Lee, Lisa

2010-01-01

369

In situ synthesis of carbon nanotubes decorated with palladium nanoparticles using arc-discharge in solution method  

Microsoft Academic Search

A unique, simple, inexpensive, and one-step synthesis route to produce carbon nanotubes (CNTs) decorated with palladium nanoparticles using a simplified dc arc-discharge in solution is reported. Zero-loss energy filtered transmission electron microscopy and scanning transmission electron microscopy confirm the presence of 3 nm palladium nanoparticles. Such palladium nanoparticles form during the reduction of palladium tetra-chloro-square-planar complex. The deconvoluted x-ray photoelectron

Debasis Bera; Suresh C. Kuiry; Matthew McCutchen; Sudipta Seal; Helge Heinrich; Grady C. Slane

2004-01-01

370

Coulometric determination of americium based on the Am(IV)/Am(III) couple in sodium-carbonate solution  

SciTech Connect

The proposed method of selective coulometric determination of americium based on the Am(IV)/Am(III) couple with the use of a mixed solution of sodium carbonate-bicarbonate at pH 10.0 as the electrolyte makes it possible to determine americium in the presence of curium, plutonium, and the rare-earth elements. The detection limit is 7 ..mu..g and the maximum relative standard deviation is 0.03.

Khizhyak, P.L.; Frenkel', V.Ya.; Lebedev, I.A.; Myasoedov, B.F.

1987-01-20

371

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

SciTech Connect

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.

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

1981-11-01

372

Influence of mass transport on the performance of carbon gas-diffusion air electrodes in alkaline solution  

Microsoft Academic Search

The effect of mass transport on the electrochemical behaviour of carbon gas-diffusion air electrodes in alkaline solution was investigated on the basis of ?E(i) curves. These curves are obtained by subtraction of potential values for an electrode operating with airEair(i) from potential values for the same electrode operating with pure oxygenEoxygen(i) at the same current densityi. Three different regions on

I. Iliev; S. Gamburzev; A. Kaisheva; J. Mrha

1975-01-01

373

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

Microsoft Academic Search

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

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

2006-01-01

374

Numerical Modeling of the Effect of Carbon Dioxide Sequestration on the Rate of Pressure Solution Creep in Limestone: Preliminary Results  

Microsoft Academic Search

When carbon dioxide (CO2) is injected into an aquifer or a depleted\\u000ageological reservoir, its dissolution into solution results in acidification of\\u000athe pore waters. As a consequence, the pore waters become more reactive, which\\u000aleads to enhanced dissolution-precipitation processes and a modification of the\\u000amechanical and hydrological properties of the rock. This effect is especially\\u000aimportant for limestones given

Francois Renard; Elisabeth Gundersen; Roland Hellmann; Marielle Collombet; Yvi Le Guen

2005-01-01

375

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

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

376

Electrochemical quartz crystal microbalance studies of single-wall carbon nanotubes in aqueous and non-aqueous solutions  

Microsoft Academic Search

The cyclic voltammetry of single-wall carbon nanotube films in aqueous solutions show the presence of broad redox responses. In non-aqueous media there is absence of redox processes when the electrolyte cation is tetrabutylammonium. However, in a Li+-containing organic electrolyte, reduction associated with lithium insertion occurs over a narrow potential range. Electrochemical quartz crystal microbalance studies in aqueous electrolytes show that

Joseph N Barisci; Gordon G Wallace; Ray H Baughman

2000-01-01

377

Azole derivatives as inhibitors for the corrosion of irradiated and non-irradiated carbon steel in HNO3 solution  

Microsoft Academic Search

Purpose – The purpose of this paper is to investigate the effects of several azole derivatives on the corrosion inhibition of irradiated and non-irradiated plain carbon steel in 0.5 M nitric acid (HNO3) solutions at 30-60°C and to study the mechanism of their inhibitive action. Design\\/methodology\\/approach – The inhibition efficiency was evaluated by means of weight-loss determinations and polarization techniques

M. Abdallah; S. T. Atwa; N. M. Abd-Allah; A. S. Fouda

2011-01-01

378

Study of the electrochemical behaviour of a carbon steel electrode in sodium sulfate aqueous solutions using electrochemical impedance spectroscopy  

Microsoft Academic Search

  \\u000a The study of a plain carbon steel (AISI 1020) in Na2SO4 aqueous solutions at different concentrations was carried out by electrochemical impedance spectroscopy (EIS) in order to\\u000a determine the corrosion mechanism and to obtain representative corrosion rates of the system. EIS was used to measure corrosion\\u000a current densities at high concentrations in the range 0.1–1 wt% Na2SO4, but in the

S. Arzola-Peralta; J. Genescá Llongueras; M. Palomar-Pardavé; M. Romero-Romo

2003-01-01

379

Radiation-induced grafting of multi-walled carbon nanotubes in glycidyl methacrylate–maleic acid binary aqueous solution  

Microsoft Academic Search

With the aim to improve the compatibility between multi-walled carbon nanotubes (MWCNTs) and nylon-6, purified MWCNTs (p-MWCNTs) were grafted successfully with glycidyl methacrylate–maleic acid in aqueous solution using a single-step radiation method. The chemical structure and morphology of grafted p-MWCNTs (g-MWCNTs) was investigated by micro-FTIR, Raman spectroscopy and transmission electron microscopy. The prepared nylon-6\\/g-MWCNTs composite has higher mechanical strength and

Haibo Yu; Xinyue Mo; Jing Peng; Maolin Zhai; Jiuqiang Li; Genshuan Wei; Xiaohong Zhang; Jinliang Qiao

2008-01-01

380

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

Microsoft Academic Search

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

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

381

In situ electrostatic assembly of CdS nanoparticles onto aligned multiwalled carbon nanotubes in aqueous solution  

Microsoft Academic Search

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

Zhao-Xia Cai; Xiu-Ping Yan

2006-01-01

382

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

Microsoft Academic Search

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,

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

1997-01-01

383

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

Microsoft Academic Search

Multi-walled carbon nanotubes (MWCNTs) are easily wrapped with a functional biopolymer—polydopamine (Pdop) through self-polymerization of dopamine in a mild basic solution. The MWCNTs@Pdop exhibits long term dispersivity in water for at least one month. The Pdop has large capacity to coordinate [PdCl4]2? and [PtCl6]2? that upon reduction transform to corresponding metal nanoparticles. The nanoparticles strongly adhere to Pdop layer and

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

2010-01-01

384

Development of a Predictive Model for Activation-Controlled Corrosion of Steel in Solutions Containing Carbon Dioxide  

Microsoft Academic Search

Corrosion of steel in carbon dioxide (COâ)-containing solutions is considered a chemical reaction-controlled process. A corrosion rate equation was derived on the basis of fundamental reaction rate theory and compared to empirically determined relationships reported in the literature. The predictive equation was developed as a function of pH, partial pressure of COâ (P{sub COâ}), and temperature. The equation allows the

B. Mishra; S. Al-Hassan; D. L. Olson; M. M. Salama

1997-01-01

385

Purification of aqueous plutonium chloride solutions via precipitation and washing.  

SciTech Connect

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 .

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

386

Losses of 14 C from roots of pulse-labelled wheat and barley during washing from soil  

Microsoft Academic Search

In crop carbon budget studies losses of root material during storage and washing of samples may cause considerable errors. To correct data from field experiments where rhizosphere C fluxes in wheat and barley were determined by14C pulse-labelling at different development stages, experiments were performed to quantify losses of14C from roots during washing. Losses of14C from wheat roots grown on nutrient

J. Swinnen; J. A. Veen; R. Merckx

1994-01-01

387

Adsorption of pesticides from aqueous solution onto banana stalk activated carbon  

Microsoft Academic Search

Activated carbon was prepared from banana stalk by potassium hydroxide (KOH) and carbon dioxide (CO2) activation and its ability to remove the pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and bentazon was explored. The banana stalk activated carbon (BSAC) was characterized by Fourier transform infrared spectroscopy (FT-IR) analysis. The adsorption kinetic data were analyzed using two kinetic models: the pseudo-first-order and pseudo-second-order models.

J. M. Salman; V. O. Njoku; B. H. Hameed

2011-01-01

388

Adsorption of phenol and reactive dye from aqueous solution on activated carbons derived from solid wastes  

Microsoft Academic Search

Activated carbons were produced from several solid wastes, namely, waste PET, waste tires, refuse derived fuel and wastes generated during lactic acid fermentation from garbage. Activated carbons having various pore size distributions were obtained by the conventional steam-activation method and via the pre-treatment method (i.e., mixture of raw materials with a metal salt, carbonization and acid treatment prior to steam-activation)

Kyuya Nakagawa; Akio Namba; Shin R Mukai; Hajime Tamon; Pisit Ariyadejwanich; Wiwut Tanthapanichakoon

2004-01-01

389

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

Microsoft Academic Search

Adsorption has been used to study the removal of atenolol, caffeine, diclofenac and isoproturon, pharmaceutical compounds as emerging contaminants and an endocrine disruptor from ultrapure water and a municipal wastewater treatment plant effluent with three carbonaceous materials: activated carbon, multiwalled carbon nanotubes and carbon nanofibers. The adsorption capacities were studied in the temperature range of 25–65°C and pH range from

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

2012-01-01

390

A simple synthesis method for nano-metal catalyst supported on mesoporous carbon: the solution plasma process.  

PubMed

High-electrocatalytic-activity noble nanoparticles (NPs) supported on carbon nanoballs (CNBs) were synthesized using an innovative plasma-in-liquid method, which is known as solution plasma processing (SPP). This technique uses a one-step method for the synthesis of NPs on carbon materials. CNBs are formed using benzene as a carbon precursor while gold (Au) or platinum (Pt) nanoparticles are generated instantaneously via sputtering from metal electrodes. The synthesized NP/CNBs were annealed at 850 °C in order to increase the conductivity of the material. The results of structural characterizations reveal that the Au and Pt NPs are smaller than 10 nm and have a uniform size distribution, and these NPs are successfully loaded onto highly mesoporous CNBs that have an average pore diameter between 13 and 16 nm. In the results from cyclic voltammetry measurements, the Au/CNBs and Pt/CNBs show clear peaks corresponding to the oxidation and reduction features in the catalytic reactions. Apart from noble nanoparticles, SPP can also be used to synthesize various kinds of NPs including bimetallic NPs loaded on spherical carbon supports by changing the working electrodes. The proposed mechanism for the synthesis is discussed in detail. This method shows potential to be a candidate for the next-generation synthesis of NP/carbon in the future. PMID:23783397

Kang, Jun; Li, Oi Lun; Saito, Nagahiro

2013-08-01

391

Adsorption of phenol and dye from aqueous solution using chemically modified date pits activated carbons  

Microsoft Academic Search

The adsorption of phenol and methylene blue (MB) on modified activated carbons has been investigated. The activated carbon was prepared from date pits by physical activation (CO2 as activating agent). Oxidation in the liquid phase with nitric acid and thermal treatment under flowing nitrogen were carried out in order to produce samples with different surface chemical properties but with no

Meriem Belhachemi; Zohra Belala; Driss Lahcene; Fatima Addoun

2009-01-01

392

Multi-walled carbon nanotubes and poly(lactic acid) nanocomposite fibrous membranes prepared by solution blow spinning.  

PubMed

Nanocomposite fibers based on multi-walled carbon nanotubes (MWCNT) and poly(lactic acid) (PLA) were prepared by solution blow spinning (SBS). Fiber morphology was characterized by scanning electron microscopy (SEM) and optical microscopy (OM). Electrical, thermal, surface and crystalline properties of the spun fibers were evaluated, respectively, by conductivity measurements (4-point probe), thermogravimetric analyses (TGA), differential scanning calorimetry (DSC), contact angle and X-ray diffraction (XRD). OM analysis of the spun mats showed a poor dispersion of MWCNT in the matrix, however dispersion in solution was increased during spinning where droplets of PLA in solution loaded with MWCNT were pulled by the pressure drop at the nozzle, producing PLA fibers filled with MWCNT. Good electrical conductivity and hydrophobicity can be achieved at low carbon nanotube contents. When only 1 wt% MWCNT was added to low-crystalline PLA, surface conductivity of the composites increased from 5 x 10(-8) to 0.46 S/cm. Addition of MWCNT can slightly influence the degree of crystallinity of PLA fibers as studied by XRD and DSC. Thermogravimetric analyses showed that MWCNT loading can decrease the onset degradation temperature of the composites which was attributed to the catalytic effect of metallic residues in MWCNT. Moreover, it was demonstrated that hydrophilicity slightly increased with an increase in MWCNT content. These results show that solution blow spinning can also be used to produce nanocomposite fibers with many potential applications such as in sensors and biosensors. PMID:22755116

Oliveira, Juliano E; Zucolotto, Valtencir; Mattoso, Luiz H C; Medeiros, Eliton S

2012-03-01

393

Effect of carbon dioxide on rheological properties and structure of polyacrylamide solutions  

Microsoft Academic Search

The effect of CO2 on rheological properties and structure of polyacrylamide solutions was studied as a function of pressure, treating time, polymer type and presence of inorganic electrolytes and natural formation rocks. It was found that the serious deterioration of the solution viscosity can be attributed mostly to the change of the solution structure, while the actual molecular degradation plays

I. Lakatos; J. Lakatos-Szabó

1996-01-01

394

One-electron oxidation in irradiated carbon tetrachloride solutions of ZnTPP, TMPD, and phenols. [Pulsed irradiation  

SciTech Connect

One-electron oxidation of phenol, p-methoxphenol, N,N,N',N'-tetramethyl-p-phenylenediamine, chlorpromazine, and zinc tetraphenolporphyrin (ZnTPP) was studied by pulse radiolysis in carbon tetrachloride solutions. Phenols form phenoxyl radicals and the other compounds form cation radicals with yields strongly dependent on solute concentration. The highest yield in deoxygenated solutions approached G = 4. In the presence of oxygen an additional oxidation step is observed owing to CCl/sub 3/O/sub 2/ radicals and the overall oxidation yield approached G = 8. ZnTPP was found to be oxidized to the cation radical without any side effects, unlike oxidation in 1,2-dichloroethane which was accompanied by demetallation owing to HCl production.

Grodkowski, J.; Neta, P.

1984-03-15

395

Removal of heavy metals occurring in the washing water of flue gas purification  

Microsoft Academic Search

Heavy metals are toxic for humans and the environment. Therefore it is important to limit the emission of these heavy metals in air, water and soil. An aqueous solution of sodium trimercapto-triazine, commercially supplied under the name TMT-15, is currently used for the removal of heavy metals occurring in the washing water from flue gas purification at the incineration plant

Bjorge Decostere; Joel Hogie; Pascal Dejans; Stijn W. H. Van Hulle

2009-01-01

396

Development of the Next Generation Watershed Model, WASH123D v2.5  

NASA Astrophysics Data System (ADS)

This paper describes the model development of WASH123D v2.5 that has included various modeling options on channel flow and surface runoff. WASH123D v2.5 is a computational hydraulic/hydrology model to simulate water flow using Saint Venant equations. The Lagrangian-Eulerian finite element method is used to solve different water waves including kinematic wave, diffusive wave and fully dynamic wave models. WASH123D can easily handle mixed subcritical, critical and supercritical flows on natural rivers. The simulations of several benchmarks are examined. Numerical results are compared with analytical solutions for manifesting the precise of model development. The analytical derivations of the benchmark problem for a wide range of cases were provided by MacDonald et al. at 1997. Simulation results are shown to perfectly agree with those of analytical solutions for kinematic wave and fully dynamic wave approaches. In lack of analytical solutions, the diffusive wave model is sequentially contrasted with previous versions of WASH123D. The results indicate that the proposed model has generated correct solutions for all three options in this model developing stage, and it could provide a useful protocol for research, prediction, and forecast related to further watershed hydrology issues.

Shih, D.; Yeh, G.

2010-12-01

397

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

PubMed Central

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

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

2013-01-01

398

Reductive dechlorination of carbon tetrachloride in aqueous solutions containing ferrous and copper ions.  

PubMed

Fe(II) associated with iron-containing minerals has been shown to be a potential reductant in natural subsurface environments. While it is known that the surface-bound iron species has the capacity to dechlorinate various chlorinated compounds, the role of transition metals to act as catalysts with these iron species is of importance. We previously observed that the reduction of Cu(II) by Fe(II) associated with goethite enhanced the dechlorination efficiency of chlorinated compound. In this study, the reductive dechlorination of carbon tetrachloride (CCl4) by dissolved Fe(II) in the presence of Cu(II) ions was investigated to understand the synergistic effect of Fe(II) and Cu(II) on the dechlorination processes in homogeneous aqueous solutions. The dechlorination efficiency of CCl4 by Fe(II) increased with increasing Cu(II) concentrations over the range of 0.2-0.5 mM and then decreased at high Cu(II) concentrations. The efficiency and rate of CCl4 dechlorination also increased with increasing dissolved Fe(II) concentration in the presence of 0.5 mM Cu(II) at neutral pH. When the Fe(II)/Cu(II) ratio varied between 1 and 10, the pseudo-first-order rate constant (k(obs)) increased 250-fold from 0.007 h(-1) at 0.5 mM Fe(II) to 1.754 h(-1) at 5 mM Fe(II). X-ray powder diffraction and scanning electron microscopy analyses showed that Cu(II) can react with Fe(II) to produce different morphologies of ferric oxides and subsequently accelerate the dechlorination rate of CCl4 at a high Fe(II) concentration. Amorphous ferrihydrite was observed when the stoichiometric Fe(II)/Cu(II) ratio was 1, while green rust, goethite, and magnetite were formed when the molar ratios of Fe(II)/Cu(II) reached 4-6. In addition, the dechlorination of CCl4 by dissolved Fe(II) is pH dependent. CCl4 can be dechlorinated by Fe(II) over a wide range of pH values in the Cu(II)-amended solutions, and the k(obs) increased from 0.0057 h(-1) at pH 4.3 to 0.856 h(-1) at pH 8.5, which was 9-25 times greater than that in the absence of Cu(II) at pH 7-8.5. The high reactivity of dissolved Fe(II) on the dechlorination of CCl4 in the presence of Cu(II) under anoxic conditions may enhance our understanding of the role of Fe(II) and the long-term reactivity of the zerovalent iron system in the dechlorination processes for chlorinated organic contaminants. PMID:15669327

Maithreepala, R A; Doong, Ruey-an

2004-12-15

399

Food worker hand washing practices: an observation study.  

PubMed

Improvement of food worker hand washing practices is critical to the reduction of foodborne illness and is dependent upon a clear understanding of current hand washing practices. To that end, this study collected detailed observational data on food worker hand washing practices. Food workers (n = 321) were observed preparing food, and data were recorded on specific work activities for which hand washing is recommended (e.g., food preparation, handling dirty equipment). Data were also recorded on hand washing behaviors that occurred in conjunction with these work activities. Results indicated that workers engaged in approximately 8.6 work activities per hour for which hand washing is recommended. However, workers made hand washing attempts (i.e., removed gloves, if worn, and placed hands in running water) in only 32% of these activities and washed their hands appropriately (i.e., removed gloves, if worn, placed hands in running water, used soap, and dried hands) in only 27% of these work activities. Attempted and appropriate hand washing rates varied by work activity--they were significantly higher in conjunction with food preparation than other work activities (46 versus < or = 37% for attempted hand washing; 41 versus < or = 30% for appropriate hand washing) and were significantly lower in conjunction with touching the body than other work activities (13 versus > or = 27% for attempted hand washing; 10 versus > or = 23% for appropriate hand washing). Attempted and appropriate hand washing rates were significantly lower when gloves were worn (18 and 16%) than when gloves were not worn (37 and 30%). These findings suggest that the hand washing practices of food workers need to be improved, glove use may reduce hand washing, and restaurants should consider reorganizing their food preparation activities to reduce the frequency with which hand washing is needed. PMID:17066921

Green, Laura R; Selman, Carol A; Radke, Vincent; Ripley, Danny; Mack, James C; Reimann, David W; Stigger, Tammi; Motsinger, Michelle; Bushnell, Lisa

2006-10-01

400

Salt Wash Field, Grand Country, Utah  

SciTech Connect

The Salt Wash field is located 15 miles southeast of Green River, Utah, in the Paradox fold and fault belt. The field was discovered in 1961 and has produced over 1.3 million bbl of oil and 11.6 billion ft[sup 3] of gas from the Mississippian Leadville LImestone. The average surface elevation is 4389 ft above sea level, and the depth to the top of the oil production is form 8500 to 8914 ft. Salt Wash field is an anticline with over 200 ft of closure on top of the Leadville. The producing zone is in the lower Leadville with intercrystalline and vuggy porosity developed in limestone and crystalline dolomitic limestone. The produced oil is a 50 to 53 API gravity crude with a 40[degrees]F pour point. The gas, a mixture of two sources, is predominately nitrogen (>70[sup [approximately

Morgan, C.D. (Utah Geological Survey, Salt Lake City, UT (United States))

1993-08-01

401

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

402

21 CFR 211.52 - Washing and toilet facilities.  

Code of Federal Regulations, 2013 CFR

...GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Buildings and Facilities § 211.52 Washing and toilet...washing facilities shall be provided, including hot and cold water, soap or detergent, air driers or single-service...

2013-04-01

403

2. VIEW OF WEST SIDE AND NORTH FACADE OF WASH ...  

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

2. VIEW OF WEST SIDE AND NORTH FACADE OF WASH HOUSE. TO RIGHT IS BERWIND-WHITE SITE OFFICE - Eureka No. 40, Wash House, East of State Route 56, North of Little Paint Creek, Scalp Level, Cambria County, PA

404

3. VIEW OF WEST SIDE OF WASH HOUSE TO RIGHT, ...  

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

3. VIEW OF WEST SIDE OF WASH HOUSE TO RIGHT, BERWIND-WHITE SITE OFFICE ON LEFT, LOOKING NORTH - Eureka No. 40, Wash House, East of State Route 56, North of Little Paint Creek, Scalp Level, Cambria County, PA

405

30 CFR 1206.260 - Allocation of washed coal.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

406

30 CFR 1206.459 - Allocation of washed coal.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

407

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

408

Exhaust gas sulfur removal by seawater washing  

SciTech Connect

The utilization of exhaust gas treatment by water washing with the objective of addressing an environmental issue is new to the marine industry. Following system evaluation, design and manufacturing, the prototype exhaust gas seawater washing system was installed outboard the ferry vessel, M/S Kronprins Harald, early in 1991. The discharged washing water is characterized by a low pH and a content of various toxic organic pollutants and toxic metals in addition to a moderate increase in sulfate concentrations. The toxic pollutants are mainly associated with particles. Additionally the effluent seawater is toxic to marine organisms due to the lowered pH. For sulfur, the prototype demonstrated a removal rate in the range of 71% to 73% at the load conditions measured and at salinities down to 14%. Compared to initial project targets for pollutant reductions, a vast deviation is demonstrated for particle removal. Also, contradictory to the technology originators' expectations, no removal of NO[sub x] was found. 1 fig., 1 tab.

Ives, R.; Klokk, S.N.

1993-09-01

409

Sorption of yttrium and rare earth elements by amorphous ferric hydroxide: Influence of solution complexation with carbonate  

NASA Astrophysics Data System (ADS)

The influence of solution complexation on the sorption of yttrium and the rare earth elements (YREEs) by amorphous ferric hydroxide was investigated at 25 °C over a range of pH (4.0-7.1) and carbonate concentrations (0M?[CO32-]?150?M). Distribution coefficients, defined as iKFeT=[MS]/(M×[S]), where [MS i] T is the total concentration of sorbed YREE, M T is the total YREE concentration in solution, and [S i] is the concentration of amorphous ferric hydroxide, initially increased in magnitude with increasing carbonate concentration, and then decreased. The initial increase of iKFeT is due to sorption of YREE carbonate complexes (MCO3+), in addition to sorption of free YREE ions (M 3+). The subsequent decrease of iKFeT, which is more extensive for the heavy REEs, is due to the increasing intensity of YREE solution complexation by carbonate ions. The competition for YREEs between solution complexation and surface complexation was modeled via the equation: iKFeT={(S?1[H]-1+S?2[H]-2+?1S}/{CO×?1COH[HCO3-][H]-2)(SK1[H]+1)×(1+HCO?1[HCO3-]+?1COH[HCO3-][H]-1+?2COH[HCO3-]T2[H]-2)} where S?1 and S?2 are equilibrium constants for free YREE surface species, ?1SCO is the equilibrium constant for the YREE-carbonate surface species, SK1 is the surface protonation constant for amorphous ferric hydroxide, and HCO?1, ?1COH, and ?2COH are YREE solution complexation constants expressed in terms of bicarbonate concentrations. The equation, which includes (i) a single new constant (?1SCO) for each YREE, (ii) previously published sorption coefficients ( S?1 and S?2) determined in the absence of carbonate, and (iii) previously published solution complexation constants, precisely predicts both the absolute magnitude of iKFeT and the pattern of iKFeT values over our range of experimental conditions. Experimentally observed iKFeT values, spanning more than five orders of magnitude, are accurately described by our surface/solution complexation model. The log?1SCOvalues determined for each YREE in this work are: Y(-1.30 ± 0.04), La(-0.39 ± 0.02), Ce(-0.21 ± 0.02), Pr(-0.22 ± 0.02), Nd(-0.20 ± 0.02), Sm(-0.20 ± 0.02), Eu(-0.26 ± 0.02), Gd(-0.38 ± 0.02), Tb(-0.40 ± 0.02), Dy(-0.51 ± 0.02), Ho(-0.57 ± 0.02), Er(-0.59 ± 0.02), Tm(-0.56 ± 0.02), Yb(-0.62 ± 0.02), and Lu(-0.59 ± 0.02).

Quinn, Kelly A.; Byrne, Robert H.; Schijf, Johan

2006-08-01

410

Adsorption of malachite green from aqueous solutions onto ordered mesoporous carbons  

Microsoft Academic Search

The carbon materials with well-ordered mesoporous tubular structure were synthesized, which were confirmed by transmission electronmicroscopy (TEM), Raman spectrum, small angle X-ray diffraction (XRD), and N2 adsorption\\/desorption analysis. Moreover, by adjusting the ratio of furfuryl alcohol (FA) and trimethylbenzene (TMB), the structural parameters of the ordered mesoporous carbons (OMCs) could be facilely tuned. The materials synthesized were applied as a

Yong Tian; Ping Liu; Xiufang Wang; Hansen Lin

2011-01-01

411

Kinetics of adsorption of dyes from aqueous solution using activated carbon prepared from waste apricot  

Microsoft Academic Search

Adsorbent (WA11Zn5) has been prepared from waste apricot by chemical activation with ZnCl2. Pore properties of the activated carbon such as BET surface area, pore volume, pore size distribution, and pore diameter were characterized by N2 adsorption and DFT plus software. Adsorption of three dyes, namely, Methylene Blue (MB), Malachite Green (MG), Crystal Violet (CV), onto activated carbon in aqueous

Yunus Önal

2006-01-01

412

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

Microsoft Academic Search

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

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

2002-01-01

413

Activated carbons from coal/pitch and polyethylene terephthalate blends for the removal of phenols from aqueous solutions  

SciTech Connect

Blends of two bituminous coals and a coal-tar pitch (CTP) with polyethylene terephthalate (PET) were evaluated as precursors of activated carbons (ACs). The intensity of the interactions between the raw materials, coal/CTP and PET during copyrolysis was closely observed by means of thermogravimetric analysis. In addition, the homogeneity of the carbon matrix of the chars produced at 800{sup o}C in a horizontal oven was studied by polarized light optical microscopy. Activated carbons were prepared from single components and their blends (1:1 w/w) by subjecting them to carbonization up to 800{sup o}C in a horizontal oven and then activation with steam at 800{sup o}C to 50% burnoff. The porous structure of the ACs was determined by sorption of N{sub 2} at 77 K and of CO{sub 2} at 273 K. The PET-containing blends produced microporous activated carbons with a maximum BET surface area of nearly 1100 m{sup 2} g{sup -1} and a maximum micropore size distribution of 0.6-0.8 nm in the case of the AC from the CTP/PET blend. The addition of PET to a bituminous coal was compared with the preoxidation of coal P in air as a way to reduce thermoplasticity and to promote the development of the porous structure. The modification of bituminous coals by PET appeared to be more effective than conventional coal preoxidation treatment. The resultant ACs were tested by measuring their effectiveness in removing phenols from an aqueous solution. The adsorption of p-chlorophenol (PCP) by the ACs prepared from the PET-containing blends was slightly higher than for the commercial activated carbon. The ability to adsorb PCP was found to be related to the volume of the super-micropores.

Ewa Lorenc-Grabowska; Grazyna Gryglewicz; Jacek Machnikowski [Wroclaw University of Technology, Gdaska (Poland). Department of Polymer and Carbonaceous Materials

2009-05-15

414

Washing scaling of GeneChip microarray expression  

PubMed Central

Background Post-hybridization washing is an essential part of microarray experiments. Both the quality of the experimental washing protocol and adequate consideration of washing in intensity calibration ultimately affect the quality of the expression estimates extracted from the microarray intensities. Results We conducted experiments on GeneChip microarrays with altered protocols for washing, scanning and staining to study the probe-level intensity changes as a function of the number of washing cycles. For calibration and analysis of the intensity data we make use of the 'hook' method which allows intensity contributions due to non-specific and specific hybridization of perfect match (PM) and mismatch (MM) probes to be disentangled in a sequence specific manner. On average, washing according to the standard protocol removes about 90% of the non-specific background and about 30-50% and less than 10% of the specific targets from the MM and PM, respectively. Analysis of the washing kinetics shows that the signal-to-noise ratio doubles roughly every ten stringent washing cycles. Washing can be characterized by time-dependent rate constants which reflect the heterogeneous character of target binding to microarray probes. We propose an empirical washing function which estimates the survival of probe bound targets. It depends on the intensity contribution due to specific and non-specific hybridization per probe which can be estimated for each probe using existing methods. The washing function allows probe intensities to be calibrated for the effect of washing. On a relative scale, proper calibration for washing markedly increases expression measures, especially in the limit of small and large values. Conclusions Washing is among the factors which potentially distort expression measures. The proposed first-order correction method allows direct implementation in existing calibration algorithms for microarray data. We provide an experimental 'washing data set' which might be used by the community for developing amendments of the washing correction.

2010-01-01

415

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

Microsoft Academic Search

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

Lihan Huang; Michael T Morrissey

1998-01-01

416

Does Washing the Biopsy Needle with PovidoneIodine Have an Effect on Infection Rates after Transrectal Prostate Needle Biopsy?  

Microsoft Academic Search

Purpose: To determine the effect of washing the biopsy needle with povidone-iodine solution on infection rates after transrectal ultrasonography-guided prostate biopsy. Patients and Methods: 180 patients with transrectal prostate biopsy were included. Infection was excluded with midstream urine culture before biopsy, and patients were divided into two groups. In group 1 (n = 84), the needle was washed with povidone-iodine

Gokhan Koc; Sitki Un; Devrim Nihat Filiz; Kaan Akbay; Yuksel Yilmaz

2010-01-01

417

Removal of copper (II) and lead (II) ions from aqueous solutions by adsorption on activated carbon from a new precursor hazelnut husks  

Microsoft Academic Search

Activated carbon was prepared from hazelnut husks with zinc chloride activation at 973 K in nitrogen atmosphere. BET surface area of the activated carbon was found 1092 m2g?1. The removal of Cu (II) and Pb (II) ions from aqueous solutions was studied by batch method. The effects of initial pH, contact time, activated carbon dosage and initial metal concentrations were

Mustafa Imamoglu; Oktay Tekir

2008-01-01

418

Preparation and characterization of activated carbon from Amygdalus Scoparia shell by chemical activation and its application for removal of lead from aqueous solutions  

Microsoft Academic Search

Two series of activated carbon have been prepared by chemical activation of Amygdalus Scoparia shell with phosphoric acid or zinc chloride for the removal of Pb(II) ions from aqueous solutions. Several methods were employed\\u000a to characterize the active carbon produced. The surface area was calculated using the standard Brunauer-Emmet-Teller method.\\u000a The microstructures of the resultant activated carbon were observed by

Sayed Z. Mohammadi; Mohammad A. Karimi; Daryoush Afzali; Fatemeh Mansouri

2010-01-01

419

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

Microsoft Academic Search

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

Hiroaki Watanabe; Haruhito Yamazaki; Xiuyun Wang; Shunichi Uchiyama

2009-01-01

420

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

PubMed

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

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

421

Effects of acid washing treatment on the adsorption equilibrium of volatile organic compounds on titanate nanotubes  

Microsoft Academic Search

Gravimetric techniques were employed to determine the adsorption capacities of titanate nanotubes (TNT) for volatile organic compounds (VOC), including n-hexane, benzene, toluene, p-xylene, m-xylene, and o-xylene, at isothermal conditions of 15, 20 and 25°C. TNT were prepared via a hydrothermal treatment of TiO2 powders in a 10M NaOH solution at 150°C for 24h, and subsequently washed with HCl aqueous solution

Chung-Kung Lee; Huang-Chi Chen; Shin-Shou Liu; Fu-Chuang Huang

2010-01-01

422

Remediation of arsenic-contaminated soils and washing effluents  

Microsoft Academic Search

Laboratory experiments were conducted to determine the distribution of various arsenic species in tailings and soils. Other specific goal of the tests were to evaluate the extraction efficiency of arsenic using alkaline or acid washing, to determine optimum operational parameters of alkaline washing, and to evaluate the arsenic precipitation of washing effluents by pH adjustment or ferric chloride addition. Alkaline

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

2005-01-01

423

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false COW tank washing machines. 157.124 Section...CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157.124 COW tank washing machines. (a) COW...

2009-07-01

424

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false COW tank washing machines. 157.124 Section...CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157.124 COW tank washing machines. (a) COW...

2010-07-01

425

Assessment and optimization of an ultrasound-assisted washing process using organic solvents for polychlorinated biphenyl-contaminated soil.  

PubMed

The goal of this work was to evaluate a washing process that uses organic solutions for polychlorinated biphenyl (PCB)-contaminated soil, and includes an ultrasound pre-treatment step to reduce operational times and organic solvent losses. In a preliminary trial, the suitability of 10 washing solutions of different polarities were tested, from which three n-hexane-based solutions were selected for further evaluation. A second set of experiments was designed using a three-level Taguchi L27 orthogonal array to model the desorption processes of seven different PCB congeners in terms of the variability of their PCB concentration levels, polarity of the washing solution, sonication time, the ratio washing solution/soil, number of extraction steps and total washing time. Linear models were developed for the desorption processes of all congeners. These models provide a good fit with the results obtained. Moreover, statistically significant outcomes were achieved from the analysis of variance tests carried out. It was determined that sonication time and ratio of washing solution/soil were the most influential process parameters. For this reason they were studied in a third set of experiments, constructed as a full factorial design. The process was eventually optimized, achieving desorption rates of more than 90% for all congeners, thus obtaining concentrations lower than 5 ppb in all cases. The use of an ultrasound-assisted soil washing process for PCB-contaminated soils that uses organic solvents seems therefore to be a viable option, especially with the incorporation of an extra step in the sonication process relating to temperature control, which is intended to prevent the loss of the lighter congeners. PMID:23771880

Bezama, Alberto; Flores, Alejandra; Araneda, Alberto; Barra, Ricardo; Pereira, Eduardo; Hernández, Víctor; Moya, Heriberto; Konrad, Odorico; Quiroz, Roberto

2013-06-14

426

Analysis of the corrosion of carbon steels in simulated salt repository brines and acid chloride solutions at high temperatures  

SciTech Connect

An analysis of literature data on the corrosion of carbon steels in anoxic brines and acid chloride solutions was performed, and the results were used to assess the expected life of high-level nuclear waste package containers in a salt repository environment. The corrosion rate of carbon steels in moderately acidic aqueous chloride environments obeys an Arrhenius dependence on temperature and a (pH{sub 2}){sup {minus}1/2} dependence on hydrogen partial pressure. The cathodic reduction of water to produce hydrogen is the rate-controlling step in the corrosion process. An expression for the corrosion rate incorporating these two dependencies was used to estimate the corrosion life of several proposed waste package configurations. 42 refs., 11 figs., 2 tabs.

Diercks, D.R.; Kassner, T.F.

1988-04-01

427

Heterogeneity of activated carbons in adsorption of phenols from aqueous solutions—Comparison of experimental isotherm data and simulation predictions  

NASA Astrophysics Data System (ADS)

Surface heterogeneity of activated carbons is usually characterized by adsorption energy distribution (AED) functions which can be estimated from the experimental adsorption isotherms by inverting integral equation. The experimental data of phenol adsorption from aqueous solution on activated carbons prepared from polyacrylonitrile (PAN) and polyethylene terephthalate (PET) have been taken from literature. AED functions for phenol adsorption, generated by application of regularization method have been verified. The Grand Canonical Monte Carlo (GCMC) simulation technique has been used as verification tool. The definitive stage of verification was comparison of experimental adsorption data and those obtained by utilization GCMC simulations. Necessary information for performing of simulations has been provided by parameters of AED functions calculated by regularization method.

Podko?cielny, P.; Nieszporek, K.

2007-01-01

428

Analysis of corrosion data for carbon steels in simulated salt repository brines and acid chloride solutions at high temperatures  

SciTech Connect

Carbon steel is currently the leading candidate material for fabrication of a container for isolation of high level nuclear waste in a salt repository. Since brine entrapped in the bedded salt can migrate to the container by several transport processes, corrosion is an important consideration in the long-term performance of the waste package. A detailed literature search was performed to compile relevant corrosion data for carbon steels in anoxic acid chloride solutions, and simulated salt repository brines at temperatures between approx. 20 and 400/sup 0/C. The hydrolysis of Mg/sup 2 +/ ions in simulated repository brines containing high magnesium concentrations causes acidification at temperatures above 25/sup 0/C, which, in turn, influences the protective nature of the magnetite corrosion product layer on carbon steel. The corrosion data for the steels were analyzed, and an analytical model for general corrosion was developed to calculate the amount of penetration (i.e., wall thinning) as a function of time, temperature, and the pressure of corrosion product hydrogen than can build up during exposure in a closed system (e.g., a sealed capsule). Both the temperature and pressure dependence of the corrosion rate of steels in anoxic acid chloride solutions indicate that the rate-controlling partial reaction is the cathodic reduction of water to form hydrogen. Variations in the composition and microstructure of the steels or the concentration of the ionic species in the chloride solutions (provided that they do not change the pH significantly) do not appear to strongly influence the corrosion rate.

Diercks, D.R.; Hull, A.B.; Kassner, T.F.

1988-03-01

429

Ion Beam Bombardment Effect on Contacts in Solution-Processed Single-Walled Carbon Nanotube Thin Film Transistor  

NASA Astrophysics Data System (ADS)

Effect of argon ion bombardment (AIB) on performance of solution-processed single-walled carbon nanotube (SWCNT) thin film transistor (TFT) has been investigated. AIB was applied to the source/drain contacts to reduce contact resistance. It was found that AIB enhances on-state current of TFT. Over 5 decades' on/off ratio is obtained by applying AIB. Results of transmission line method using metallic SWCNT clearly indicate that contact resistance between CNT network and Au electrode is reduced by the application of AIB.

Yi, Xun; Nakagawa, Gou; Ozawa, Hiroaki; Fujigaya, Tsuyohiko; Nakashima, Naotoshi; Asano, Tanemasa

2011-09-01

430

The dissociation of carbonic acid in NaCl solutions as a function of concentration and temperature  

Microsoft Academic Search

Potentiometric measurements of the stoichiometric constants for the dissociation of carbonic acid in NaCl solutions (K1?=[H+][HCO3-]\\/[CO2] and K1?=[H+][CO32-]\\/[HCO3-]) have been made as a function of molality (0–6m) and temperature (0–50°C). The results have been fitted to the equationspKi?-pKi=Ai+Bi\\/T+CilnTThe values of pKi in pure water are taken from the literature and the adjustable parameters Ai, Bi and Ci are a function

Frank Millero; Fen Huang; Taylor Graham; Denis Pierrot

2007-01-01

431

Washing and alkaline leaching of Hanford tank sludges: A status report  

SciTech Connect

Because of the assumed high cost of high-level waste (HLW) immobilization and disposal, pretreatment methods are being developed to minimize the volume of HLW requiring vitrification. Pacific Northwest Laboratory (PNL) is investigating several options for pretreating the radioactive wastes stored in underground tanks at the Hanford Site. The pretreatment methods under study for the tank sludges include: (1) simply washing the sludges with dilute NaOH, (2) performing caustic leaching (as well as washing) to remove certain wash components, and (3) dissolving the sludges in acid and extracting key radionuclides from the dissolved sludge solutions. The data collected in this effort will be used to support the March 1998 decision on the extent of pretreatment to be performed on the Hanford tank sludges. This document describes sludge washing and caustic leaching tests conducted in FY 1994. These tests were performed using sludges from single-shell tanks (SST) B-201 and U-110. A summary is given of all the sludge washing and caustic leaching studies conducted at PNL in the last few years.

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

1994-09-01

432

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

SciTech Connect

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

Geeting, John GH; Hallen, Richard T.

2005-02-15

433

Plasma induced grafting carboxymethyl cellulose on multiwalled carbon nanotubes for the removal of UO(2)(2+) from aqueous solution.  

PubMed

Carboxymethyl cellulose (CMC) is grafted on multiwalled carbon nanotubes (MWCNT) by using plasma techniques. The CMC grafted MWCNT (MWCNT-g-CMC) is characterized by using Fourier transform infrared spectra (FT-IR), Raman spectra, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA)-differential thermal analysis (DTA), scanning electron microscopy (SEM), and N(2)-BET methods in detail. The application of MWCNT-g-CMC in the removal of UO(2)(2+) from aqueous solution is investigated. MWCNT-g-CMC has much higher sorption ability in the removal of UO(2)(2+) than raw MWCNT. The MWCNT-g-CMC is a suitable material in the preconcentration and solidification of heavy metal ions from large volume of aqueous solutions. PMID:19128017

Shao, Dadong; Jiang, Zhongqing; Wang, Xiangke; Li, Jiaxing; Meng, Yuedong

2009-01-29

434

Electrochemical reduction of uranium(VI) in nitric acid-hydrazine solution on glassy carbon electrode  

Microsoft Academic Search

Electrochemical reduction of U(VI) in nitric acid-hydrazine solution is greatly influenced by the concentration of nitric\\u000a acid. In low acidity nitric acid solution such as 0.1M (M=mol\\/dm3) HNO3, U(VI) was firstly reduced to U(V) and then partially reduced to U(IV). In high acidity nitric acid solution, e.g., 3-6M\\u000a HNO3, an electrode process of two-electron transfer was involved in the reduction

Y.-Z. Wei; B. Fang; T. Arai; M. Kumagai

2004-01-01

435

pH-dependence of calcite growth kinetics at constant solution calcium to carbonate activity ratio and supersaturation: an in situ Atomic Force Microscopy study  

Microsoft Academic Search

Calcite-solution reactions (growth, dissolution and replacement) are critical in a range of both engineering and natural processes. Classical crystal growth theory relates calcite growth rates to the degree of supersaturation. The solution composition may also affect the growth rate of carbonate minerals, via the Ca2+ to CO32- concentration ratio (Nehrke et al., 2007; Perdikouri et al., 2009), ionic strength (Zuddas

Encarnación Ruiz-Agudo; Christine V. Putnis; Carlos Manuel Rodriguez-Navarro; Andrew Putnis

2010-01-01

436

Effects of activated carbon surface chemistry and pore structure on the adsorption of trace organic contaminants from aqueous solution  

NASA Astrophysics Data System (ADS)

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.

Li, Lei

437

Determination of free chlorine concentrations needed to prevent Escherichia coli O157:H7 cross-contamination during fresh-cut produce wash.  

PubMed

This study was conducted to investigate the effect of free chlorine concentrations in wash water on Escherichia coli O157:H7 reduction, survival, and transference during washing of fresh-cut lettuce. The effectiveness of rewashing for inactivation of E. coli O157:H7 on newly cross-contaminated produce previously washed with solutions containing an insufficient amount of chlorine also was assessed. Results indicate that solutions containing a minimum of 0.5 mg/liter free chlorine were effective for inactivating E. coli O157:H7 in suspension to below the detection level. However, the presence of 1 mg/liter free chlorine in the wash solution before washing was insufficient to prevent E. coli O157:H7 survival and transfer during washing because the introduction of cut lettuce to the wash system quickly depleted the free chlorine. Although no E. coli O157:H7 was detected in the wash solution containing 5 mg/liter free chlorine before washing a mix of inoculated and uninoculated lettuce, low numbers of E. coli O157:H7 cells were detected on uninoculated lettuce in four of the seven experimental trials. When the prewash free chlorine concentration was increased to 10 mg/liter or greater, no E. coli O157:H7 transfer was detected. Furthermore, although rewashing newly cross-contaminated lettuce in 50 mg/liter free chlorine for 30 s significantly reduced (P = 0.002) the E. coli O157:H7 populations, it failed to eliminate E. coli O157:H7 on lettuce. This finding suggests that rewashing is not an effective way to correct for process failure, and maintaining a sufficient free chlorine concentration in the wash solution is critical for preventing pathogen cross-contamination. PMID:21375869

Luo, Yaguang; Nou, Xiangwu; Yang, Yang; Alegre, Isabel; Turner, Ellen; Feng, Hao; Abadias, Maribel; Conway, William

2011-03-01

438

Arc-discharge in solution: A novel synthesis method for carbon nanotubes and in situ decoration of carbon nanotubes with nanoparticles  

NASA Astrophysics Data System (ADS)

During the last decade, carbon nanotubes (CNTs) have been envisioned for a host of different new applications. One of the objectives of the present research is to develop a simplified synthesis method for the production of large-scale, low-cost carbon nanotubes with functionality. Herein, a unique, simple, inexpensive and one-step synthesis route of CNTs and CNTs decorated with nanoparticles is reported. The method is simple arc-discharge in solution (ADS). For this new method, a full-fledged optoelectronically controlled instrument is reported here to achieve high efficiency and continuous bulk production of CNTs. In this system, a constant gap between the two electrodes is maintained using a photosensor which allows a continuous synthesis of the carbon nanostructures. The system operates in a feedback loop consisting of an electrode-gap detector and an analogue electronic unit, as controller. This computerized feed system was also used in single process step to produce in situ-decorated CNTs with a variety of industrially important nanoparticles. To name a few, we have successfully synthesized CNTs decorated with 3--4 nm ceria, silica and palladium nanoparticles for many industrially relevant applications. This process can be extended to synthesize decorated CNTs with other oxide and metallic nanoparticles. Sixty experimental runs were carried out for parametric analysis varying process parameters including voltage, current and precursors. The amount of yield with time, rate of erosion of the anode, and rate of deposition of carbonaceous materials on the cathode electrode were investigated. Normalized kinetic parameters were evaluated for different amperes from the sets of runs. The production rate of pristine CNT at 75 A is as high as 5.89 +/- 0.28 g.min-1. In this study, major emphasis was given on the characterizations of CNTs with and without nanoparticles using various techniques for surface and bulk analysis of the nanostructures. The nanostructures were characterized using transmission electron microscopy, high resolution transmission electron microscopy, scanning transmission electron microscopy, energy dispersive spectroscopy and scanning electron microscopy, x-ray photo electron spectroscopy, x-ray diffraction studies, and surface area analysis. Electron microscopy investigations show that the CNTs, collected from the water and solutions, are highly pure except for the presence of some amorphous carbon. (Abstract shortened by UMI.)

Bera, Debasis

439

Influence of passivity on the tribocorrosion of carbon steel in aqueous solutions  

Microsoft Academic Search

The degradation of DIN 34CrNiMo6 steel sliding against alumina was investigated in NaOH and in borate buffer solutions of pH 8.4 under electrochemically applied passive potentials. Small amounts of chromate or chloride were added to the borate solutions to vary the nature of the passive film. Film thickness and composition were characterised using surface analysis (Auger electron spectroscopy (AES) and

S. Mischler; A. Spiegel; M. Stemp; D. Landolt

2001-01-01

440

VANADIUM51, CARBON13 AND PROTON FTNMR STUDIES ON VANADIUM (V) SPECIES IN AQUEOUS SOLUTIONS  

Microsoft Academic Search

The solution chemistry of the Stretford Process--a liquid redox, cyclic process employed to efficiently remove hydrogen sulfide from sour gases--is not fully understood. The intent of the present work is to investigate the speciation of metavanadate ions in aqueous and in Stretford-like solutions; the interactions between vanadium (V) species and several oxygen- and nitrogen-donating ligands and the molecular microdynamics of

MAHMOUD ADAM H HABAYEB

1981-01-01

441

Removal of arsenite and arsenate ions from aqueous solution by basic yttrium carbonate  

Microsoft Academic Search

A new method has been developed to remove arsenite and arsenate ions from aquatic systems by using basic yttrium carbonate (BYC). Various parameters such as pH, anion concentration and reaction time were studied to establish optimum conditions. The removal by adsorption of arsenite and arsenate ions was found to be > 99% depending on initial concentration in the pH range

Syed A. Wasay; Akira Uchiumi; Shuzo Tokunaga

1996-01-01

442

Dislocation Damping in Nickel-Carbon Solid Solutions in the Process of Plastic Deformation.  

National Technical Information Service (NTIS)

Low frequency damping in the process of plastic deformation of nickel containing various amounts of carbon was measured on a small tensile testing machine. A series of internal friction peaks was observed on the internal friction-strain curve when the spe...

Ko T'ing-Sui Chang Chao-Yuan

1967-01-01

443

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

Microsoft Academic Search

Preparation of activated carbon from sewage sludge is a promising approach to produce cheap and efficient adsorbent for pollutants removal as well as to dispose of sewage sludge. The first objective of this study was to investigate the physical and chemical properties (BET surface area, ash and elemental content, surface functional groups by Boehm titration and weight loss by thermogravimetric

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

2011-01-01

444

Electrochemical oxidation of carbon fibres in aqueous solutions and analysis of the surface oxides  

Microsoft Academic Search

Carbon fibres with notably different surface oxides can be prepared by varying the electrochemical oxidation conditions. Through correlation of voltammetric analysis and mass spectroscopy, interpretation of the reduction peaks of the surface oxides on the basis of their potential and width is possible. Narrow voltammetric reduction peaks at strongly negative potential are indicative of the predominance of -COOH type groups,

A. D. Jannakoudakis; P. D. Jannakoudakis; E. Theodoridou; J. O. Besenhard

1990-01-01

445

Effect of iron manganese oxide solid solutions on selectivity for lower hydrocarbons from carbon monoxide hydrogenation  

Microsoft Academic Search

There exists considerable current interest in the study of catalysts that demonstrate high selectivities for Câ-Câ hydrocarbons from carbon monoxide hydrogenation. In this respect iron manganese matrix catalysts have been well studied by a number of authors since Koelbel initially disclosed that these catalysts could give high yields of Câ-Câ hydrocarbons with a corresponding very low methane selectivity. The mechanism

G. J. Hutchings; J. C. A. Boeyens

1986-01-01

446

Degradation of aqueous solution of potassium iodide and sodium cyanide in the presence of carbon tetrachloride  

Microsoft Academic Search

The degradation of potassium iodide, carbon tetrachloride and sodium cyanide has been studied using an ultrasounic probe of 20 kHz frequency. In the case of potassium iodide and sodium cyanide, the rate of degradation was much higher in presence of CCl4. The location of the ultrasonic horn showed a significant effect in the degradation of CCl4.

I. Z. Shirgaonkar; A. B. Pandit

1997-01-01

447

Selectivity of chemical oxidation attack of single-wall carbon nanotubes in solution  

Microsoft Academic Search

Chemical oxidation of single wall carbon nanotubes (SWNTs), produced with the HiPco method, is studied by resonance Raman scattering. The analysis of the radial breathing mode makes it possible to assign the observed bands to metallic and semiconducting SWNTs and to suggest the chiral indices of SWNTs contributing to the spectra. On this basis we observe that the most important

Enzo Menna; Federico della Negra; Michela dalla Fontana; Moreno Meneghetti

2003-01-01

448

Supercritical carbon dioxide extraction of metals from aqueous solutions: a review  

Microsoft Academic Search

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,

Can Erkey

2000-01-01

449

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

Microsoft Academic Search

The Savannah River Site (SRS) will disperse or dissolve precipitated metal oxides as part of radioactive waste tank closure operations. Previously SRS has utilized oxalic acid to accomplish this task. Since the waste tanks are constructed of carbon steel, a significant amount of corrosion may occur. Although the total amount of corrosion may be insignificant for a short contact time,

B Wiersma; J John Mickalonis

2007-01-01

450

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

EPA Science Inventory

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

451

Hand washing practices in a college town environment.  

PubMed

Many people do not wash their hands when the behavior in which they engage would warrant it. Most research of hand washing practices to date has taken place in high-traffic environments such as airports and public attraction venues. These studies have established a persistent shortcoming and a gender difference in hand washing compliance. Using field observations of 3,749 people in a college town environment, the research described in this article replicates and extends earlier work while identifying potential environmental and demographic predictors of hand washing compliance. Additionally, the authors' research suggests that proper hand washing practices, as recommended by the Centers for Disease Control and Prevention, are not being practiced. Finally, the authors' research raises a question as to the accuracy of earlier measurements of "proper" hand washing practices, suggesting that compliance rates are inflated. The results can help increase hand washing rates for the general public and thus decrease the risk of transmitting disease. PMID:23621052

Borchgrevink, Carl P; Cha, JaeMin; Kim, SeungHyun

2013-04-01

452

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

SciTech Connect

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

Not Available

2002-09-01

453

PACU-why hand washing is vital!  

PubMed

Hand washing is one of the oldest methods of reducing infections. Recent evidence based research has re-confirmed the efficacy of proper hand hygiene and recommendations for hand hygiene by the CDC and WHO are outlined. The PACU is a unique environment; patients are in a "cross-road of infection;" many patients are exposed to infections coming from various wards brought to the PACU through the OR. The PACU nurse is not only responsible for observing and monitoring the patient's vital signs but is also responsible for making sure patients are not exposed to an additional risk, e.g. a hand-transmitted infection. PMID:19647664

Petty, William Clayton

2009-08-01

454

Hand washing and diarrhoea in adolescents  

Microsoft Academic Search

Aim  This study aimed to characterize hand washing among 13-year-old adolescents, assessing the association with the occurrence\\u000a of diarrhoea.\\u000a \\u000a \\u000a \\u000a \\u000a Subject and methods  We evaluated 2,036 adolescents enrolled in schools of Porto, Portugal. Information was collected by self-administered questionnaires.\\u000a Odds ratio (OR) and 95% confidence intervals (95% CI) were used to estimate associations.\\u000a \\u000a \\u000a \\u000a \\u000a Results  Male adolescents reported more frequently than female adolescents that they

Abel Gomes; Sílvia Fraga; Elisabete Ramos

455

Effects of pressure and solution composition on mineral weathering rates as applied to geologic storage of carbon dioxide  

NASA Astrophysics Data System (ADS)

CO2-mediated weathering of silicate minerals and subsequent carbonate mineral precipitation may allow permanent trapping of carbon dioxide stored in deep saline aquifers. The time-scales and extents of the relevant reactions, however, are incompletely understood for receptor reservoir conditions. To address current shortcomings, experiments were conducted to investigate the effects of pressure, pH, and dissolved inorganic carbon (C) concentration on rates and mechanisms of silicate mineral dissolution. A 500 cm3 high-pressure stirred flow-through reactor was used to contact 53-106 mm size-fraction forsteritic olivine ((Mg0.89Fe0.11)2SiO4) with C-rich and C-free aqueous solutions. The system allowed monitoring and control of temperature (40° C), total pressure (105 and 107 Pa), pH (3.1 and 7.1), flow rate (0.03 and 0.13 cm3 s-1), and dissolved inorganic carbon concentration. Effluent samples were analyzed using inductively coupled plasma spectrometry to determine total aqueous magnesium, iron, and silicon concentrations for inference of quasi-steady state mineral dissolution rates. Mineral solids were characterized both pre- and post-dissolution using N2-adsorption and scanning electron microscopy with energy dispersive X-ray analysis. Mean forsteritic olivine dissolution rates derived from aqueous silicon concentrations show strong dependence on pH (3.0 x 10-12 mol cm-2 s-1 at pH 3.1 and 1.0 x 10-13 mol cm-2 s-1 at pH 7.1) and are consistent with previously published values at ambient conditions. No effect of pressure on dissolution rate was observed in the absence of dissolved inorganic carbon, suggesting ambient pressure measurements may be used to characterize deep subsurface mineral dissolution rates. However, preliminary analyses indicate a possible olivine dissolution rate enhancement due to the presence of inorganic carbon. Minor morphological alteration with no apparent chemical modification was observed in post-dissolution olivine grains; however, discrete Fe-carbonate precipitates appear to have formed during pH 7.1, C-rich experiments.

Bruant, R. G.; Giammar, D. E.; Peters, C. A.

2003-12-01

456

Carbonates.  

National Technical Information Service (NTIS)

There are approximately 150 carbonate minerals that occur in nature; however, most of these carbonates are relatively rare. The most common rock-forming carbonates are calcite (CaC03) and dolomite (CaMg(C03)2), which account for over 90 % of natural carbo...

D. W. Ming

2001-01-01

457

Separation of hazardous organics by low-pressure membranes: treatment of soil-wash rinse-water leachates. Rept. for Jan 90-Jan 92  

SciTech Connect

Soil washing is a promising technology for treating contaminated soils. In the present work, low-pressure, thin-film composite membranes were evaluated to treat the soil-wash leachates so that the treated water could be recycled back to the soil washing step. Experiments were done with SARM (Synthetic Analytical Reference Matrix) soils. Membrane performance was evaluated with leachates obtained from different wash solutions. The effect of fine suspensions in the leachates was also studied. A solution-diffusion model was modified to include an adsorption resistance term in water flux, and this term was correlated with bulk concentration using the Freundlich isotherm. The correlation was then used to predict water flux drop at different bulk concentrations or to predict water flux at different recoveries. Thin-film composite membranes were found to effectively treat the leachate from rinse water used to wash contaminated soil. In addition, feed preozonation significantly improved water flux.

Bhattacharyya, D.; Kothari, A.

1992-03-01

458

Composition and method for providing stain resistance to polyamide fibers using carbonated solutions  

SciTech Connect

This patent describes an aqueous carbonated composition for treating polyamide fibers to impart stain resistance to the fibers. It comprises between about 0.0015 to 1.5% w. of a dye-resist agent consisting of a condensation product of formaldehyde and a member selected from the group consisting of a sulfonated phenol or a sulfonated naphthol; 0 to 6.0% w. of a fluorochemical; and 0 to 5% w. of a detergent suitable for cleaning polyamide fibers with the remainder being made up of an inert aqueous carrier; the aqueous composition being maintained at a pH of between about 2.5 to 7.0 means of the carbonation.

Beck, B.R.; Harris, R.D.

1991-04-23

459

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

460

Phenol removal from aqueous solution by activated carbon produced from avocado kernel seeds  

Microsoft Academic Search

Activated carbon derived from avocado kernels (AAC) was evaluated for its ability to remove phenol. The Brunauer–Emmett–Teller (BET) surface area of the AAC was 206m2g?1 and the total pore volume was 0.100cm3g?1. The kinetic of the adsorption process was described by a pseudo-second-order rate model. The maximum uptake was obtained at pH values between 4 and 8.5. The optimum adsorbent

Liana Alvares Rodrigues; Maria Lucia Caetano Pinto da Silva; Manoel Orlando Alvarez-Mendes; Aparecido dos Reis Coutinho; Gilmar Patrocínio Thim

2011-01-01

461

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

Microsoft Academic Search

Carbon prepared from peanut hulls (PHC) has been used for the adsorption of Pb(II) over a range of initial metal ion concentrations (10–20 mg\\/L), agitation times (5–140 minutes), adsorbent dosages (5–100 mg\\/100 mL), and pH values (1.5–10.0). Adsorption of Pb(II) obeyed the Langmuir isotherm. The applicability of the Lagergren kinetic model has also been investigated. Quantitative removal of 20 mg\\/L

K. Periasamy; C. Namasivayam

1995-01-01

462

Inhibitory action of aqueous coffee ground extracts on the corrosion of carbon steel in HCl solution  

Microsoft Academic Search

The effects of aqueous extracts of spent coffee grounds on the corrosion of carbon steel in a 1molL?1 HCl were examined. Two methods of extraction were studied: decoction and infusion. The inhibition efficiency of C-steel in 1molL?1 HCl increased as the extract concentration and temperature increased. The coffee extracts acted as a mixed-type inhibitor with predominant cathodic effectiveness. In this

Vanessa Vasconcelos Torres; Roberto Salgado Amado; Camila Faia de Sá; Tatiana Lopez Fernandez; Carlos Alberto da Silva Riehl; Alexandre Guedes Torres; Eliane D’Elia

2011-01-01

463

Application of multi-walled carbon nanotubes functionalized with hemin for oxygen detection in neutral solution  

Microsoft Academic Search

Functionalization of multi-walled carbon nanotubes (MWNTs) is of paramount importance for developing new sensors. In this study, a hemin-modified MWNT electrode was successfully constructed. Upon saturation, the amount of adsorbed hemin is estimated as 2.7×10?9 mol cm?2, which is 39 times larger than the value of the hemin monolayer. The electrochemical behavior of the hemin-modified MWNT electrode has been characterized

Jian-Shan Ye; Ying Wen; Wei De Zhang; Hui-Fang Cui; Leong Ming Gan; Guo Qin Xu; Fwu-Shan Sheu

2004-01-01

464

Flexible organic light-emitting diodes with transparent carbon nanotube electrodes: problems and solutions  

Microsoft Academic Search

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

Liangbing Hu; Jianfeng Li; Jun Liu; George Grüner; Tobin Marks

2010-01-01

465

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

Microsoft Academic Search

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 COâ 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

Sheng Dai; Jeseung Lee; Costas Tsouris; David W. DePaoli; Xiqing Wang

2010-01-01

466

High adsorption capacity NaOH-activated carbon for dye removal from aqueous solution  

Microsoft Academic Search

In this study, the surface coverage ratio (Sc\\/Sp) and monolayer cover adsorption amount per unit surface area (qmon\\/Sp) were employed to investigate the adsorption isotherm equilibrium of the adsorption of dyes (AB74, BB1 and MB) on NaOH-activated carbons (FWNa2, FWNa3 and FWNa4); the adsorption rate of the Elovich equation (1\\/b) and the ratio of 1min adsorption amount of adsorbate to

Feng-Chin Wu; Ru-Ling Tseng

2008-01-01