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Sample records for aqueous wastes wet

  1. Advanced methods for the treatment of organic aqueous wastes: wet air oxidation and wet peroxide oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Debellefontaine, Hubert; Chakchouk, Mehrez; Foussard, Jean Noel [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France). Dept. de Genie des Procedes Industriels; Tissot, Daniel; Striolo, Phillipe [IDE Environnement S.A., Toulouse (France)

    1993-12-31

    There is a growing concern about the problems of wastes elimination. Various oxidation techniques are suited for elimination of organic aqueous wastes, however, because of the environmental drawbacks of incineration, liquid phase oxidation should be preferred. `Wet Air Oxidation` and `Wet Peroxide Oxidation`are alternative processes which are discussed in this paper. 17 refs., 13 figs., 4 tabs.

  2. Manganese zinc ferrite nanoparticles as efficient catalysts for wet peroxide oxidation of organic aqueous wastes

    Indian Academy of Sciences (India)

    Manju Kurian; Divya S Nair

    2015-03-01

    Manganese substituted zinc nanoparticles, MnxZn1−xFe2O4 (x = 0.0, 0.25, 0.5, 0.75, 1.0) prepared by sol gel method were found to be efficient catalysts for wet peroxide oxidation of 4-chlorophenol. Complete degradation of the target pollutant occurred within 90 min at 70°C. Zinc substitution enhanced the catalytic efficiency and the unsubstituted ZnFe2O4 oxidized the target compound completely within 45 min. Studies on the effect of reaction variables revealed that only a small amount of the oxidant, H2O2 (3–4 mL) is required for complete degradation of 4-chlorophenol. More than 80% of 4-chlorophenol was removed at catalyst concentrations of 100 mg/L. Direct correlation between the amount of catalyst present and the extent of degradation of 4-chlorophenol was observed, ruling out hesterogeneous-homogeneous mechanism. The catalysts are reusable and complete degradation of target pollutant occurred after five successive runs. The extent of iron leaching was fairly low after five consecutive cycles indicating the mechanism to be heterogeneous.

  3. Root cause analysis for wet waste generation

    International Nuclear Information System (INIS)

    Since, typically, most utility radioactive waste is dry waste, volume reduction efforts should start with this. However, significant cost can still be saved with a modest reduction in the wet radioactive waste volume. Even though there may be several potential solutions to wet waste volume reduction, a Root Cause Analysis should be performed to identify the solution that will be the most effective for volume reduction. The method described here provides for a logical sequence of determining root causes. Finally, the solution adopted must be evaluated after implementation to determine its effectiveness and verify that the root cause was addressed

  4. Wet oxidation of a spacecraft model waste

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T.

    1985-01-01

    Wet oxidation was used to oxidize a spacecraft model waste under different oxidation conditions. The variables studied were pressure, temperature, duration of oxidation, and the use of one homogeneous and three heterogeneous catalysts. Emphasis is placed on the final oxidation state of carbon and nitrogen since these are the two major components of the spacecraft model waste and two important plant nutrients.

  5. Aqueous humor cytokine profiling in patients with wet AMD

    Science.gov (United States)

    Liu, Fang; Ding, Xiaoyan; Yang, Yu; Li, Jiaqing; Tang, Miao; Yuan, Miner; Hu, Andina; Zhan, Zongyi; Li, Zijing

    2016-01-01

    Purpose To investigate the chemokine expression profiles in the aqueous humor of wet age-related macular degeneration (wet AMD) patients and to correlate their levels with clinical findings. Methods Undiluted aqueous humor samples (100–200 μl) were obtained from 16 wet AMD eyes and 12 control eyes. Forty chemokines were measured using a multiplex method. A 6×6 mm area of the macular region centered on the fovea was examined using spectral domain optical coherence tomography (SD-OCT). Results The detection rates were 50% or more for 15 chemokines. Compared with the control group, the aqueous humor in wet AMD patients showed a significantly higher expression of CXCL10 (p=0.004), CCL14 (p=0.002), CXCL16 (p=0.013), CXCL7 (p=0.033), and CCL22 (p=0.037), while growth-related oncogene (GRO) was significantly decreased in the wet AMD patients (p=0.001). When compared with treatment-naïve patients, the recurrent group had significant upregulation of CXCL10 (p=0.012) and CCL22 (p=0.002). CXCL16 was positively correlated with lesion size, and CCL22 was higher in patients whose OCT images showed intraretinal fluid (IRF) or hyperreflective foci (HF). Conclusions Elevated levels of inflammation-related chemokines, including CXCL10, CCL14, CXCL16, CXCL7, and CCL22, in the aqueous humor of AMD patients may suggest a pathogenic role for inflammation. CXCL10 and CCL22 were more elevated in eyes with recurrent wet AMD than in treatment-naïve eyes. CXCL16 was positively correlated with lesion size. The increase in CCL22 was correlated with the presence of IRF or HF. These data may be of interest in the search for biomarkers associated with wet AMD and may potentially indicate different treatment strategies. PMID:27122966

  6. Mercury separation from aqueous wastes

    International Nuclear Information System (INIS)

    This project is providing an assessment of new sorbents for removing mercury from wastes at US Department of Energy sites. Four aqueous wastes were chosen for lab-scale testing; a high-salt, acidic waste currently stored at Idaho National Engineering Laboratory (INEL); a high-salt, alkaline waste stored at the Savannah River Site (SRS); a dilute lithium hydroxide solution stored at the Oak Ridge Y-12 Plant; and a low-salt, neutral groundwater generated at the Y-12 Plant. Eight adsorbents have been identified for testing, covering a wide range of cost and capability. Screening tests have been completed, which identified the most promising adsorbents for each waste stream. Batch isotherm tests have been completed using the most promising adsorbents, and column tests are in progress. Because of the wide range of waste compositions tested, no one adsorbent is effective in all of these waste streams. Based on loading capacity and compatibility with the waste solutions. the most effective adsorbents identified to date are SuperLig 618 for the INEL tank waste stimulant; Mersorb followed by lonac SR-3 for the SRS tank waste stimulant; Durasil 70 and Ionac SR-3) for the LIOH solution; and lonac SR-3 followed by lonac SR-4 and Mersorb for the Y-12 groundwater

  7. Technetium removal from aqueous wastes

    International Nuclear Information System (INIS)

    The research discussed in this report has compared several ''state of the art'' techniques for the removal of traces of the radionuclide, technetium, from aqueous wastes. The techniques investigated were: electrochemical reduction to an insoluble oxide, electrochemical ion exchange, seeded ultrafiltration and chemical reduction followed by filtration. Each technique was examined using a simulant based upon the waste generated by the Enhanced Actinide Removal Plant (EARP) at Sellafield. The technique selected for further investigation was direct electrochemical reduction which offers an ideal route for the removal of technetium from the stream (DFs 10-100) and can be operated continuously with a low power consumption 25 kW for the waste generated by EARP. Cell designs for scale up have been suggested to treat the 1000m3 of waste produced every day. Future work is proposed to investigate the simultaneous removal of other key radionuclides, such as ruthenium, plutonium and cobalt as well as scale up of the resulting process and to investigate the effect of these other radionuclides on the efficiency of the electrochemical reduction technique for the removal of technetium. Total development and full scale plant costs are estimated to be of the order of 5 pounds - 10M, with a time scale of 5 -8 years to realisation. (author)

  8. Treatment of wet solid low-level radioactive waste

    International Nuclear Information System (INIS)

    Recently low-level radioactive waste has caused much concern because of its long term impact on the environment. Most of the low-level radioactive waste is produced by nuclear power plants while a small fraction comes from medical applications, for example, radioactive isotopes. This waste exists in gas, liquid and solid forms. Research was carried out on wet solid low-level wastes, which were treated with polymeric materials. Their properties and applications were studied and evaluated. Wet solid radioactive wastes come from evaporated condensates produced by light-water reactors. The main component of boiling-water reactor waste is Na2SO4 and that of pressure-water reactor waste is H3BO3. Furthermore the spent ion exchange resin also constitutes a major portion of the solid radioactive waste. In this research, unsaturated polyesters, such as ETERSET 2565P and 2144 HCM, were employed to solidify the wastes; i.e. Na2SO4, Ca3(BO3)2.2H2O, cationic ion exchange resin Duolite ARA 9366 and anionic ion exchange resin Duolite ARC 9351. It was found that the properties, such as density, compressive strength, water resistance and thermal stability of unsaturated polyester solidified wastes were excellent. The radiation resistance could be as high as 108 Rad and the leachability was low. The volume reduction ratios of all samples were better than those of cement solidified waste

  9. Aqueous Corrosion Rates for Waste Package Materials

    Energy Technology Data Exchange (ETDEWEB)

    S. Arthur

    2004-10-08

    The purpose of this analysis, as directed by ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]), is to compile applicable corrosion data from the literature (journal articles, engineering documents, materials handbooks, or standards, and national laboratory reports), evaluate the quality of these data, and use these to perform statistical analyses and distributions for aqueous corrosion rates of waste package materials. The purpose of this report is not to describe the performance of engineered barriers for the TSPA-LA. Instead, the analysis provides simple statistics on aqueous corrosion rates of steels and alloys. These rates are limited by various aqueous parameters such as temperature (up to 100 C), water type (i.e., fresh versus saline), and pH. Corrosion data of materials at pH extremes (below 4 and above 9) are not included in this analysis, as materials commonly display different corrosion behaviors under these conditions. The exception is highly corrosion-resistant materials (Inconel Alloys) for which rate data from corrosion tests at a pH of approximately 3 were included. The waste package materials investigated are those from the long and short 5-DHLW waste packages, 2-MCO/2-DHLW waste package, and the 21-PWR commercial waste package. This analysis also contains rate data for some of the materials present inside the fuel canisters for the following fuel types: U-Mo (Fermi U-10%Mo), MOX (FFTF), Thorium Carbide and Th/U Carbide (Fort Saint Vrain [FSVR]), Th/U Oxide (Shippingport LWBR), U-metal (N Reactor), Intact U-Oxide (Shippingport PWR, Commercial), aluminum-based, and U-Zr-H (TRIGA). Analysis of corrosion rates for Alloy 22, spent nuclear fuel, defense high level waste (DHLW) glass, and Titanium Grade 7 can be found in other analysis or model reports.

  10. Aqueous Corrosion Rates for Waste Package Materials

    International Nuclear Information System (INIS)

    The purpose of this analysis, as directed by ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]), is to compile applicable corrosion data from the literature (journal articles, engineering documents, materials handbooks, or standards, and national laboratory reports), evaluate the quality of these data, and use these to perform statistical analyses and distributions for aqueous corrosion rates of waste package materials. The purpose of this report is not to describe the performance of engineered barriers for the TSPA-LA. Instead, the analysis provides simple statistics on aqueous corrosion rates of steels and alloys. These rates are limited by various aqueous parameters such as temperature (up to 100 C), water type (i.e., fresh versus saline), and pH. Corrosion data of materials at pH extremes (below 4 and above 9) are not included in this analysis, as materials commonly display different corrosion behaviors under these conditions. The exception is highly corrosion-resistant materials (Inconel Alloys) for which rate data from corrosion tests at a pH of approximately 3 were included. The waste package materials investigated are those from the long and short 5-DHLW waste packages, 2-MCO/2-DHLW waste package, and the 21-PWR commercial waste package. This analysis also contains rate data for some of the materials present inside the fuel canisters for the following fuel types: U-Mo (Fermi U-10%Mo), MOX (FFTF), Thorium Carbide and Th/U Carbide (Fort Saint Vrain [FSVR]), Th/U Oxide (Shippingport LWBR), U-metal (N Reactor), Intact U-Oxide (Shippingport PWR, Commercial), aluminum-based, and U-Zr-H (TRIGA). Analysis of corrosion rates for Alloy 22, spent nuclear fuel, defense high level waste (DHLW) glass, and Titanium Grade 7 can be found in other analysis or model reports

  11. Discussion about the application of treatment process for dehydrated wet waste at nuclear power station

    International Nuclear Information System (INIS)

    In nuclear power station, the most popular treatment about low level radioactive wet waste generated during the unit operating and maintenance is embedded by cement. For radioactive waste minimization, this article introduces a new treatment process to dehydrate and compress wet waste. According to the development and application of the treatment process for the wet waste, and comparing with the formerly treatment-the cement embedding, prove that the new treatment can meet the purpose for volume reduction of wet waste. (authors)

  12. Potential of wet blue leather waste for ruminant feeding

    OpenAIRE

    Rodrigo Carvalho Silva; João Chrysostomo de Resende Júnior; Ronaldo Francisco de Lima; Raimundo Vicente de Sousa; Luiz Carlos Alves de Oliveira; João Luiz Pratti Daniel; Anselmo de Oliveira Moreira

    2012-01-01

    The objective of this study was to find an alternative to minimize environmental contamination by leather waste using it as ruminant feed. The wet blue leather wastes (WB) without chrome extraction were compared with the leather wastes in which the chrome was extracted (CE). Both materials had 99.7% of dry matter (DM), but the crude protein level was higher (90.4%) in CE than in WB (74.3%). In situ effective ruminal degradability of DM was 59.7% and it was 63.1% for CP in CE. The WB did not s...

  13. Wet oxidation as a waste treatment in closed systems

    Science.gov (United States)

    Onisko, B. L.; Wydeven, T.

    1981-01-01

    The chemistry of the wet oxidation process has been investigated in relation to production of plant nutrients from plant and human waste materials as required for a closed life-support system. Hydroponically grown lettuce plants were used as a model plant waste and oxygen gas was used as oxidant. Organic nitrogen content was decreased 88-100% depending on feed material. Production of ammonia and nitrogen gas account for all of the observed decrease in organic nitrogen content. No nitrous oxide (N2O) was detected. The implications of these results for closed life-support systems are discussed.

  14. Wet Oxidation as a Waste Treatment Method in Closed Systems

    Science.gov (United States)

    Onisko, B. L.; Wydeven, T.

    1982-01-01

    The chemistry of the wet oxidation process was investigated in relation to production of plant nutrients from plant and human waste materials as required for a closed life support system. Hydroponically grown lettuce plants were used as a model plant waste, and oxygen gas was used as an oxidant. Organic nitrogen content was decreased 88-100%, depending on feed material. Production of ammonia and nitrogen gas accounted for all of the observed decrease in organic nitrogen content. No nitrous oxide (N2O) was detected. The implications of these results for closed life support systems are discussed.

  15. Potential of wet blue leather waste for ruminant feeding

    Directory of Open Access Journals (Sweden)

    Rodrigo Carvalho Silva

    2012-04-01

    Full Text Available The objective of this study was to find an alternative to minimize environmental contamination by leather waste using it as ruminant feed. The wet blue leather wastes (WB without chrome extraction were compared with the leather wastes in which the chrome was extracted (CE. Both materials had 99.7% of dry matter (DM, but the crude protein level was higher (90.4% in CE than in WB (74.3%. In situ effective ruminal degradability of DM was 59.7% and it was 63.1% for CP in CE. The WB did not suffer degradation in the rumen. In vitro abomasal digestibility of CE was 100%. The percentage of degradation per hour was higher for CE (8.2% than for WB (0.08%. The mineral content was higher in wet blue leather wastes (10.4% than in CE (0.4% reflecting the chrome level and demonstrating that the removal process of this mineral is efficient. The use in animal feed is presented as a viable alternative for the disposal of waste and scrap generated by the leather tanning industry and treated by the extraction method, thus minimizing environmental contamination and providing a source of protein for animal feed.

  16. Wetting Behavior and Heat Transfer of Aqueous Graphene Nanofluids

    Science.gov (United States)

    Nayak, Vignesh U.; Prabhu, Narayan K.

    2016-04-01

    Aqueous graphene nanofluids having concentrations 0.01, 0.1, and 0.3 vol.% were used as heat transfer media during quenching of ISO 9950 inconel alloy probe. Contact angle measurements were carried out to assess the wettability of graphene nanofluids. Nanofluids showed better wettability compared to base water with over 16% reduction in their contact angles. The cooling performance of the quench media was assessed by cooling curve analysis during quenching of an instrumented inconel probe from 860 °C into the quench medium. Recorded temperature readings showed longer vapor phase stage during quenching with nanofluids. The severity of nanofluids was found to be lower relative to water. During quenching with nanofluids, the estimated spatiotemporal heat flux transients at the metal/quenchant interface showed that more heat was removed during the vapor phase stage of cooling. The present study brings out the possibility of using stable water-graphene nanoplatelet suspensions for quench heat treatment of steel components requiring cooling severity between water and oil/polymer quenchants.

  17. Handling and treatment of radioactive aqueous wastes

    International Nuclear Information System (INIS)

    This report aims to provide essential guidance to developing Member States without a nuclear power programme regarding selection, design and operation of cost effective treatment processes for radioactive aqueous liquids arising as effluents from small research institutions, hospitals and industries. The restricted quantities and low activity associated with the relevant wastes will generally permit contact-handling and avoid the need for shielding requirements. The selection of liquid waste treatment involves: Characterization of arising with the possibility of segregation; Discharge requirements for decontaminated liquors, both radioactive and non-radioactive; Available technologies and costs; Conditioning of the concentrates resulting from the treatment; Storage and disposal of the conditioned concentrates. The report will serve as a technical manual providing reference material and direct step-by-step know-how to staff in radioisotope user establishments and research centres in the developing Member States without nuclear power generation. Therefore, emphasis is limited to the simpler treatment facilities, which will be included with only the robust, well-established waste management processes carefully chosen as appropriate to developing countries. 20 refs, 12 figs, 7 tabs

  18. Size distribution of wet crushed waste printed circuit boards

    Institute of Scientific and Technical Information of China (English)

    Tan Zhihai; He Yaqun; Xie Weining; Duan Chenlong; Zhou Enhui; Yu Zheng

    2011-01-01

    A wet impact crusher was used to breakdown waste printed circuit boards (PCB's) in a water medium.The relationship between the yield of crushed product and the operating parameters was established.The crushing mechanism was analyzed and the effects of hammerhead style,rotation speed,and inlet water volume on particle size distribution were investigated.The results show that the highest yield of -1 + 0.75 mm sized product was obtained with an inlet water volume flow rate of 5.97 m3/h and a smooth hammerhead turning at 1246.15 r/min.Cumulative undersize-product yield curves were fitted to a nonlinear function:the fitting correlation coefficient was greater than 0.998.These research results provide a theoretical basis for the highly effective wet crushing of PCB's.

  19. Enhanced Oil Recovery from Oil-wet Carbonate Rock by Spontaneous Imbibition of Aqueous Surfactant Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Standnes, Dag Chun

    2001-09-01

    The main theme of this thesis is an experimental investigation of spontaneous imbibition (SI) of aqueous cationic surfactant solution into oil-wet carbonate (chalk- and dolomite cores). The static imbibition process is believed to represent the matrix flow of oil and water in a fractured reservoir. It was known that aqueous solution of C{sub 12}-N(CH{sub 3}){sub 3}Br (C12TAB) was able to imbibe spontaneously into nearly oil-wet chalk material, but the underlying mechanism was not understood. The present work was therefore initiated, with the following objectives: (1) Put forward a hypothesis for the chemical mechanism underlying the SI of C12TAB solutions into oil-wet chalk material based on experimental data and (2) Perform screening tests of low-cost commercially available surfactants for their ability to displace oil by SI of water into oil-wet carbonate rock material. It is essential for optimal use of the surfactant in field application to have detailed knowledge about the mechanism underlying the SI process. The thesis also discusses some preliminary experimental results and suggests mechanisms for enhanced oil recovery from oil-wet carbonate rock induced by supply of thermal energy.

  20. Development and testing of a wet oxidation waste processing system. [for waste treatment aboard manned spacecraft

    Science.gov (United States)

    Weitzmann, A. L.

    1977-01-01

    The wet oxidation process is considered as a potential treatment method for wastes aboard manned spacecraft for these reasons: (1) Fecal and urine wastes are processed to sterile water and CO2 gas. However, the water requires post-treatment to remove salts and odor; (2) the residual ash is negligible in quantity, sterile and easily collected; and (3) the product CO2 gas can be processed through a reduction step to aid in material balance if needed. Reaction of waste materials with oxygen at elevated temperature and pressure also produces some nitrous oxide, as well as trace amounts of a few other gases.

  1. Wet-oxidation waste management system for CELSS

    Science.gov (United States)

    Takahashi, Y.; Ohya, H.

    1986-01-01

    A wet oxidation system will be useful in the Closed Ecological Life Support System (CELSS) as a facility to treat organic wastes and to redistribute inorganic compounds and elements. However at rather higher temperatures needed in this reaction, for instance, at 260 deg C, only 80% of organic in a raw material can be oxidized, and 20% of it will remain in the liquid mainly as acetic acid, which is virtually noncombustible. Furthermore, nitrogen is transformed to ammonium ions which normally cannot be absorbed by plants. To resolve these problems, it becomes necessary to use catalysts. Noble metals such as Ru, Rh and so on have proved to be partially effective as these catalysts. That is, oxidation does not occur completely, and the unexpected denitrification, instead of the expected nitrification, occurs. So, it is essential to develop the catalysts which are able to realize the complete oxidation and the nitrification.

  2. Thin wetting films from aqueous electrolyte solutions on SiC/Si wafer.

    Science.gov (United States)

    Diakova, B; Filiatre, C; Platikanov, D; Foissy, A; Kaisheva, M

    2002-02-25

    The stability and rupture of thin wetting films from aqueous NaCl or Na2SO4 solutions of different concentrations on silicon carbide were investigated. The flat surface of SiC was obtained by plasma-enhanced chemical vapor deposition (PE-CVD) on top of a silicon wafer. The microinterferometric method was used for measuring the film thickness with time. The light reflectance was calculated as a function of film thickness for the four-layer system: air/aqueous solution/SiC/Si wafer. The microinterferometric experiments showed that films from aqueous NaCl and Na2SO4 solutions with concentrations up to 0.01 M were stable independent of the pre-treatment of the substrate. The pre-treatment of the SiC surface was crucial for the wetting film stability at electrolyte concentrations greater than 0.01 M. The films were unstable and ruptured if SiC was washed with 5% hydrofluoric acid and concentrated sulfuric acid, while they were stable if washing was in sulfuric acid only, without immersing SiC in HF. The average equilibrium film thickness was determined as a function of electrolyte concentration. Measurements of the electrokinetic potential zeta were performed by electrophores of SiC powder in 0.001 M NaCl. It was shown that silicon carbide surface was negatively charged. The theory of heterocoagulation was used for the interpretation of the results. Besides the DLVO forces, the structural disjoining pressure (both positive and negative) has been included in the analysis. PMID:11908786

  3. Wet oxidative degradation of cellulosic wastes 5- chemical and thermal properties of the final waste forms

    International Nuclear Information System (INIS)

    In this study, the residual solution arising from the wet oxidative degradation of solid organic cellulosic materials, as one of the component of radioactive solid wastes, using hydrogen peroxide as oxidant. Were incorporated into ordinary Portland cement matrix. Leaching as well as thermal characterizations of the final solidified waste forms were evaluated to meet the final disposal requirements. Factors, such as the amount of the residual solution incorporated, types of leachant. Release of different radionuclides and freezing-thaw treatment, that may affect the leaching characterization. Were studied systematically from the data obtained, it was found that the final solid waste from containing 35% residual solution in tap water is higher than that in ground water or sea water. Based on the data obtained from thermal analysis, it could be concluded that incorporating the residual solution form the wet oxidative degradation of cellulosic materials has no negative effect on the hydration of cement materials and consequently on the thermal stability of the final solid waste from during the disposal process

  4. Resíduos sólidos de curtumes como adsorventes para a remoção de corantes em meio aquoso Solid waste from tanneries as adsorbent for the removal of dyes in aqueous medium

    OpenAIRE

    Rogério Marcos Dallago; Alessandra Smaniotto; Luiz Carlos Alves de Oliveira

    2005-01-01

    The tanning process in the leather industry generates very high quantities of chromium-containing solid waste ("wet blue" leather). Environmental concerns and escalating landfill-costs are becoming increasingly serious problems for the leather industry and an alternative disposal is needed. In this work, we are presenting a novel application for this solid waste, which is the removal of organic contaminants from aqueous-solution. The adsorption isotherm of "wet blue" leather waste from the AU...

  5. Chemical precipitation processes for the treatment of aqueous radioactive waste

    International Nuclear Information System (INIS)

    Chemical precipitation by coagulation-flocculation and sedimentation has been commonly used for many years to treat liquid (aqueous) radioactive waste. This method allows the volume of waste to be substantially reduced for further treatment or conditioning and the bulk of the waste to de discharged. Chemical precipitation is usually applied in combination with other methods as part of a comprehensive waste management scheme. As with any other technology, chemical precipitation is constantly being improved to reduce cost to increase the effectiveness and safety on the entire waste management system. The purpose of this report is to review and update the information provided in Technical Reports Series No. 89, Chemical Treatment of Radioactive Wastes, published in 1968. In this report the chemical methods currently in use for the treatment of low and intermediate level aqueous radioactive wastes are described and illustrated. Comparisons are given of the advantages and limitations of the processes, and it is noted that good decontamination and volume reduction are not the only criteria according to which a particular process should be selected. Emphasis has been placed on the need to carefully characterize each waste stream, to examine fully the effect of segregation and the importance of looking at the entire operation and not just the treatment process when planning a liquid waste treatment facility. This general approach includes local requirements and possibilities, discharge authorization, management of the concentrates, ICRP recommendations and economics. It appears that chemical precipitation process and solid-liquid separation techniques will continue to be widely used in liquid radioactive waste treatment. Current research and development is showing that combining different processes in one treatment plant can provide higher decontamination factors and smaller secondary waste arisings. Some of these processes are already being incorporated into new and

  6. Improved aqueous extraction of microalgal lipid by combined enzymatic and thermal lysis from wet biomass of Nannochloropsis oceanica.

    Science.gov (United States)

    Chen, Lin; Li, Runzhi; Ren, Xiaoli; Liu, Tianzhong

    2016-08-01

    High moisture content in wet algal biomass hinders effective performance of current lipid extraction methods. An improved aqueous extraction method combing thermal and enzymatic lysis was proposed and performed in algal slurry of Nannochloropsis oceanica (96.0% moisture) in this study. In general, cell-wall of N. oceanica was disrupted via thermal lysis and enzymatic lysis and lipid extraction was performed using aqueous surfactant solution. At the optimal conditions, high extraction efficiencies for both lipid (88.3%) and protein (62.4%) were obtained, which were significantly higher than those of traditional hexane extraction and other methods for wet algal biomass. Furthermore, an excessive extraction of polar lipid was found for wet biomass compared with dry biomass. The advantage of this method is to efficiently extract lipids from high moisture content algal biomass and avoid using organic solvent, indicating immense potential for commercial microalgae-based biofuel production. PMID:27132220

  7. Treatability study of aqueous, land disposal restricted mixed wastes

    International Nuclear Information System (INIS)

    Treatment studies have been completed on two aqueous waste streams at the Mixed Waste Storage Facility that are classified as land disposal restricted. Both wastes had mercury and lead as characteristic hazardous constituents. Samples from one of these wastes, composed of mercury and lead sulfide particles along with dissolved mercury and lead, was successfully treated by decanting, filtering, and ion exchanging. The effluent water had an average level of 0.003 and 0.025 mg/L of mercury and lead, respectively. These values are well below the targeted RCRA limits of 0.2 mg/L mercury and 5.0 mg/L lead. An acidic stream, containing the same hazardous metals, was also successfully treated using a treatment process of precipitation, filtering, and then ion exchange. Treatment of another waste was not completely successful, presumably because of the interference of a chelating agent

  8. Solid waste management practices in wet coffee processing industries of Gidabo watershed, Ethiopia.

    Science.gov (United States)

    Ulsido, Mihret D; Li, Meng

    2016-07-01

    The financial and social contributions of coffee processing industries within most coffee export-based national economies like Ethiopia are generally high. The type and amount of waste produced and the waste management options adopted by these industries can have negative effects on the environment. This study investigated the solid waste management options adopted in wet coffee processing industries in the Gidabo watershed of Ethiopia. A field observation and assessment were made to identify whether the operational characteristics of the industries have any effect on the waste management options that were practiced. The investigation was conducted on 125 wet coffee processing industries about their solid waste handling techniques. Focus group discussion, structured questionnaires, key informant interview and transect walks are some of the tools employed during the investigation. Two major types of wastes, namely hull-bean-pulp blended solid waste and wastewater rich in dissolved and suspended solids were generated in the industries. Wet mills, on average, released 20.69% green coffee bean, 18.58% water and 60.74% pulp by weight. Even though these wastes are rich in organic matter and recyclables; the most favoured solid waste management options in the watershed were disposal (50.4%) and industrial or household composting (49.6%). Laxity and impulsive decision are the driving motives behind solid waste management in Gidabo watershed. Therefore, to reduce possible contamination of the environment, wastes generated during the processing of red coffee cherries, such as coffee wet mill solid wastes, should be handled properly and effectively through maximisation of their benefits with minimised losses. PMID:27091048

  9. Development of a Catalytic Wet Air Oxidation Method to Produce Feedstock Gases from Waste Polymers

    Science.gov (United States)

    Kulis, Michael J.; Guerrero-Medina, Karen J.; Hepp, Aloysius F.

    2012-01-01

    Given the high cost of space launch, the repurposing of biological and plastic wastes to reduce the need for logistical support during long distance and long duration space missions has long been recognized as a high priority. Described in this paper are the preliminary efforts to develop a wet air oxidation system in order to produce fuels from waste polymers. Preliminary results of partial oxidation in near supercritical water conditions are presented. Inherent corrosion and salt precipitation are discussed as system design issues for a thorough assessment of a second generation wet air oxidation system. This work is currently being supported by the In-Situ Resource Utilization Project.

  10. Donnan dialysis for the treatment of aqueous wastes

    International Nuclear Information System (INIS)

    Commercially available ion exchange membranes with high selectivity and chemical stability make attractive the use of Donnan dialysis as a separation process for the treatment of industrial liquid aqueous wastes. The concentration of metal ions in solution, by using a chemical gradient across a selective cationic membrane, can be the basis for new hybrid processes in which well-known chemical treatments and membrane separation are coupled. Donnan dialysis separations of two ions of different charge Sr(II) and Cr(III), by means of perfluorinated Nafion membranes in tubular form, are discussed by taking into account different hydrodynamic and chemical conditions in the feed and strip solutions. Results are compared with other hybrid processes for the treatment of low activity nuclear wastes (Sr-90) and conventional wastes (chromate and Cr(III)). (author)

  11. Solid waste from leather industry as adsorbent of organic dyes in aqueous-medium

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luiz C.A. [Universidade Federal de Lavras, Depto. de Quimica, Caixa Postal 37, CEP 37200.000, Lavras-MG (Brazil)]. E-mail: luizoliveira@ufla.br; Goncalves, Maraisa [Universidade Federal de Lavras, Depto. de Quimica, Caixa Postal 37, CEP 37200.000, Lavras-MG (Brazil); Oliveira, Diana Q.L. [Universidade Federal de Lavras, Depto. de Quimica, Caixa Postal 37, CEP 37200.000, Lavras-MG (Brazil); Guerreiro, Mario C. [Universidade Federal de Lavras, Depto. de Quimica, Caixa Postal 37, CEP 37200.000, Lavras-MG (Brazil); Guilherme, Luiz R.G. [Universidade Federal de Lavras, Depto. de Ciencia do solo, CEP 37200.000, Lavras-MG (Brazil); Dallago, Rogerio M. [URI-Campus Erechim, Av. 7 Setembro 1621, Centro, CEP 99700-000, Depto de Quimica, Erechim-RS (Brazil)

    2007-03-06

    The industrial tanning of leather usually produces considerable amounts of chromium-containing solid waste and liquid effluents and raises many concerns on its environmental effect as well as on escalating landfill costs. Actually, these shortcomings are becoming increasingly a limiting factor to this industrial activity that claims for alternative methods of residue disposals. In this work, it is proposed a novel alternative destination of the solid waste, based on the removal of organic contaminants from the out coming aqueous-residue. The adsorption isotherm pattern for the wet blue leather from the Aurea tanning industry in Erechim-RS (Brazil) showed that these materials present high activity on adsorbing the reactive red textile dye as well as other compounds. The adsorbent materials were characterized by IR spectroscopy and SEM and tested for the dye adsorption (reactive textile and methylene blue dyes). The concentrations of dyes were measured by UV-vis spectrophotometry and the chromium extraction from leather waste was realized by basic hydrolysis and determined by atomic absorption. As a low cost abundant adsorbent material with high adsorption ability on removing dye methylene blue (80 mg g{sup -1}) and textile dye reactive red (163 mg g{sup -1}), the leather waste is revealed to be a interesting alternative relatively to more costly adsorbent materials.

  12. Solid waste from leather industry as adsorbent of organic dyes in aqueous-medium

    International Nuclear Information System (INIS)

    The industrial tanning of leather usually produces considerable amounts of chromium-containing solid waste and liquid effluents and raises many concerns on its environmental effect as well as on escalating landfill costs. Actually, these shortcomings are becoming increasingly a limiting factor to this industrial activity that claims for alternative methods of residue disposals. In this work, it is proposed a novel alternative destination of the solid waste, based on the removal of organic contaminants from the out coming aqueous-residue. The adsorption isotherm pattern for the wet blue leather from the Aurea tanning industry in Erechim-RS (Brazil) showed that these materials present high activity on adsorbing the reactive red textile dye as well as other compounds. The adsorbent materials were characterized by IR spectroscopy and SEM and tested for the dye adsorption (reactive textile and methylene blue dyes). The concentrations of dyes were measured by UV-vis spectrophotometry and the chromium extraction from leather waste was realized by basic hydrolysis and determined by atomic absorption. As a low cost abundant adsorbent material with high adsorption ability on removing dye methylene blue (80 mg g-1) and textile dye reactive red (163 mg g-1), the leather waste is revealed to be a interesting alternative relatively to more costly adsorbent materials

  13. Low-temperature catalytic gasification of wet industrial wastes

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D C; Neuenschwander, G G; Baker, E G; Sealock, Jr, L J; Butner, R S

    1991-04-01

    Bench-scale reactor tests are in progress at Pacific Northwest Laboratory to develop a low-temperature, catalytic gasification system. The system, licensed under the trade name Thermochemical Environmental Energy System (TEES{reg sign}), is designed for treating a wide variety of feedstocks ranging from dilute organics in water to waste sludges from food processing. This report describes a test program which used a continuous-feed tubular reactor. This test program is an intermediate stage in the process development. The reactor is a laboratory-scale version of the commercial concept as currently envisioned by the process developers. An energy benefit and economic analysis was also completed on the process. Four conceptual commercial installations of the TEES process were evaluated for three food processing applications and one organic chemical manufacturing application. Net energy production (medium-Btu gas) was achieved in all four cases. The organic chemical application was found to be economically attractive in the present situation. Based on sensitivity studies included in the analysis, the three food processing cases will likely become attractive in the near future as waste disposal regulations tighten and disposal costs increase. 21 refs., 2 figs., 9 tabs.

  14. Long Term Stability Testing Results for Savannah River Site Organic and Aqueous Waste streams

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) has tasked MSE Technology Applications, Inc. (MSE) with evaluating the long-term stability of various commercially available sorbent materials to solidify two organic surrogate waste streams (both volatile and nonvolatile), a volatile organic waste stream with a residual aqueous phase, an aqueous waste stream, and an aqueous waste stream with a residual organic phase. The Savannah River Site (SRS) legacy plutonium/uranium extraction (PUREX) process waste and the F-Canyon PUREX waste constituted the volatile organic wastes and various oils constituted the nonvolatile organic waste stream. The aqueous waste streams included a rainwater waste stream and an aqueous organic waste stream. MSE also evaluated the PUREX waste stream with a residual aqueous component with and without aqueous-type sorbent materials. Based on testing performed at MSE, the rainwater waste stream was successfully solidified by SRS personnel using two different sorbents. Several small oil wastes were also successfully solidified by SRS personnel using granular clay sorbents based on information provided by MSE from the oils waste stream testing and 75,706 Liters (L) [20,000 gallons (gal)] of the F-Canyon PUREX waste was solidified at Waste Consolidation Specialists (WCS). Solidification of the various surrogate waste streams listed above was performed from 2004 to 2006 at the MSE testing and evaluation facility located at the Mike Mansfield Advanced Technology Center in Butte, Montana. This paper summarizes the comparison of the initial liquid release testing (LRT) values with LRT results obtained over three years later in an attempt to understand the long-term stability characteristics of the solidified waste streams. The paper also includes solidification results for B-25 box samples generated late in 2005. (authors)

  15. A new low-cost method of reclaiming mixed foundry waste sand based on wet-thermal composite reclamation

    Institute of Scientific and Technical Information of China (English)

    Fan Zitian; Liu Fuchu; Long Wei; Li Guona

    2014-01-01

    A lot of mixed clay-resin waste sand from large-scale iron foundries is discharged every day; so mixed waste sand reclamation in low cost and high quality has a great realistic significance. In the study to investigate the possibility of reusing two types of waste foundry sands, resin bonded sand and clay bonded sand which came from a Chinese casting factory, a new low-cost reclamation method of the mixed foundry waste sand based on the wet-thermal composite reclamation was proposed. The waste resin bonded sand was first reclaimed by a thermal method and the waste clay bonded sand was reclaimed by a wet method. Then, hot thermal reclaimed sand and the dehydrated wet reclaimed sand were mixed in certain proportions so that the hot thermal reclaimed sand dried the wet reclaimed sand leaving some water. The thermal reclamation efficiency of the waste resin bonded sand was researched at different heat levels. The optimized wet reclamation process of the waste clay bonded sand was achieved by investigating the effects of wet reclamation times, sand-water ratio and pH value on the reclaimed sand characteristics. The composite reclamation cost also was calculated. The research results showed that the properties of the mixed reclaimed sand can satisfy the application requirements of foundries; in which the temperature of the thermal reclamation waste resin bonded sand needs to be about 800 ºC, the number of cycles of wet reclamation waste clay bonded sand should reach four to five, the optimal sand-water ratio of wet reclamation is around 1:1.5, and the pH value should be adjusted by adding acid. The mass ratio of hot thermal reclaimed sand to dehydrated wet reclaimed sand is about 1:2.5, and the composite reclaimed sand cost is around 100 yuan RMB per ton.

  16. Biosorption of arsenic from aqueous solution using dye waste.

    Science.gov (United States)

    Nigam, Shubha; Vankar, Padma S; Gopal, Krishna

    2013-02-01

    The purpose of this study is to examine on removal of arsenic from water by biosorption through potential application of herbal dye wastes. Four different flower dye residues (after extraction of natural dye) viz. Hibiscus rosasinensis, Rosa rosa, Tagetes erecta, and Canna indica were utilized successfully for the removal of arsenic from aqueous solution. Batch studies were carried out for various parameters viz. pH, sorbent dose, contact time, initial metal ion concentration, and temperature. Data were utilized for isothermal, kinetic, and thermodynamic studies. Scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDAX), and Fourier transform infrared (FTIR) analyses of biomass were performed. The results showed that 1 g/100 ml for 5.0-5.5 h contact time at pH 6.0-7.5 with agitation rate 150 rpm provided 98, 96, 92, and 85 % maximum absorption of arsenic by R. rosa, H. rosasinensis, T. erecta, and C. indica, respectively, at initial concentration of 500 ppb. Data followed Langmuir isotherm showing sorption to be monolayer on heterogeneous surface of biosorbent. Negative values of ΔG° indicated spontaneous nature, whereas ΔH° indicates exothermic nature of system followed by pseudo-first-order adsorption kinetics. FTIR results showed apparent changes in functional group regions after metal chelation. SEM and EDAX analyses showed the changes in surface morphology of all test biosorbents. Herbal dye wastes, used as biosorbent, exhibited significant (85-98 %) removal of arsenic from aqueous solution. Hence, these biosorbents are cost-effective, easily available, eco-friendly, and comparatively more effective than other biosorbents already in use. These may be used to remove arsenic and other toxic metals from water. PMID:22661261

  17. Resíduos sólidos de curtumes como adsorventes para a remoção de corantes em meio aquoso Solid waste from tanneries as adsorbent for the removal of dyes in aqueous medium

    Directory of Open Access Journals (Sweden)

    Rogério Marcos Dallago

    2005-06-01

    Full Text Available The tanning process in the leather industry generates very high quantities of chromium-containing solid waste ("wet blue" leather. Environmental concerns and escalating landfill-costs are becoming increasingly serious problems for the leather industry and an alternative disposal is needed. In this work, we are presenting a novel application for this solid waste, which is the removal of organic contaminants from aqueous-solution. The adsorption isotherm of "wet blue" leather waste from the AUREA tanning company in Erechim-RS (Brazil showed that this material presents high adsorption capacities of the reactive textile dyes.

  18. Production of lipase extrated from aqueous waste: enzymatic activity kinetics

    Directory of Open Access Journals (Sweden)

    Tatianne Ferreira de Oliveira

    2014-12-01

    Full Text Available Lipases are an important group of enzymes with various applications in the food, chemical and pharmaceutical industry, besides having great interest for the treatment of effluents with high lipid content. The objective of this study was to isolate, characterize and select lipolytic bacteria that produce lipase from aqueous waste effluents and to study the enzymatic activity kinetics of the extract obtained via submerged fermentation. The results obtained are promising, being possible to isolate and characterize 23 lipase-producing microorganisms, mostly gram-positive bacteria, but after the fermentation step in a liquid medium, gram negative bacteria showed the highest enzymatic activity (56.72 U.L-1 for STP 2A` bacterium and 81.99 U.L-1 for R2B. In the enzymatic activity kinetic study with the selected bacterium (R2B, among the six variables (temperature, pH, minimal mineral medium, soybean oil, glucose and sodium nitrate, temperature was the one that most positively influenced the enzymatic activity, and the best results were obtained at 40°C. It was concluded that the enzyme extract obtained from environmental waste may be used to treat the effluent and contribute to reduce environmental impacts.

  19. Application of wet waste from shrimp ( Litopenaeus vannamei) with or without sea mud to feeding sea cucumber ( Stichopus monotuberculatus)

    Science.gov (United States)

    Chen, Yanfeng; Hu, Chaoqun; Ren, Chunhua

    2015-02-01

    In the present study, the applicability of the wet waste collected from shrimp ( Litopenaeus vannamei) to the culture of sea cucumber ( Stichopus monotuberculatus) was determined. The effects of dietary wet shrimp waste on the survival, specific growth rate (SGR), fecal production rate (FPR), ammonia- and nitrite-nitrogen productions of sea cucumber were studied. The total organic matter (TOM) level in the feces of sea cucumber was compared with that in corresponding feeds. Diet C (50% wet shrimp waste and 50% sea mud mash) made sea cucumber grow faster than other diets. Sea cucumber fed with either diet D (25% wet shrimp waste and 75% sea mud mash) or sole sea mud exhibited negative growth. The average lowest total FPR of sea cucumber occurred in diet A (wet shrimp waste), and there was no significant difference in total FPR between diet C and diet E (sea mud mash) ( P > 0.05). The average ammonia-nitrogen production of sea cucumber in different diet treatments decreased gradually with the decrease of crude protein content in different diets. The average highest nitrite-nitrogen production occurred in diet E treatment, and there was no significant difference in nitrite-nitrogen production among diet A, diet B (75% wet shrimp waste and 25% sea mud mash) and diet C treatments ( P > 0.05). In each diet treatment, the total organic matter (TOM) level in feces decreased to different extent compared with that in corresponding feeds.

  20. Application of Wet Waste from Shrimp (Litopenaeus vannamei) with or Without Sea Mud to Feeding Sea Cucumber (Stichopus monotuberculatus)

    Institute of Scientific and Technical Information of China (English)

    CHEN Yanfeng; HU Chaoqun; RENChunhua

    2015-01-01

    In the present study, the applicability of the wet waste collected from shrimp (Litopenaeus vannamei) to the culture of sea cucumber (Stichopus monotuberculatus) was determined. The effects of dietary wet shrimp waste on the survival, specific growth rate (SGR), fecal production rate (FPR), ammonia- and nitrite-nitrogen productions of sea cucumber were studied. The total organic matter (TOM) level in the feces of sea cucumber was compared with that in corresponding feeds. Diet C (50% wet shrimp waste and 50% sea mud mash) made sea cucumber grow faster than other diets. Sea cucumber fed with either diet D (25% wet shrimp waste and 75% sea mud mash) or sole sea mud exhibited negative growth. The average lowest total FPR of sea cucumber occurred in diet A (wet shrimp waste), and there was no significant difference in total FPR between diet C and diet E (sea mud mash) (P>0.05). The average ammonia-nitrogen production of sea cucumber in different diet treatments decreased gradually with the decrease of crude protein content in different diets. The average highest nitrite-nitrogen production occurred in diet E treatment, and there was no sig-nificant difference in nitrite-nitrogen production among diet A, diet B (75% wet shrimp waste and 25% sea mud mash) and diet C treatments (P>0.05). In each diet treatment, the total organic matter (TOM) level in feces decreased to different extent compared with that in corresponding feeds.

  1. SPONTANEOUS CATALYTIC WET AIR OXIDATION DURING PRE-TREATMENT OF HIGH-LEVEL RADIOACTIVE WASTE SLUDGE

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, D.; Herman, C.; Pareizs, J.; Bannochie, C.; Best, D.; Bibler, N.; Fellinger, T.

    2009-10-01

    Savannah River Remediation, LLC (SRR) operates the Defense Waste Processing Facility for the U.S. Department of Energy at the Savannah River Site. This facility immobilizes high-level radioactive waste through vitrification following chemical pretreatment. Catalytic destruction of formate and oxalate ions to carbon dioxide has been observed during qualification testing of non-radioactive analog systems. Carbon dioxide production greatly exceeded hydrogen production, indicating the occurrence of a process other than the catalytic decomposition of formic acid. Statistical modeling was used to relate the new reaction chemistry to partial catalytic wet air oxidation of both formate and oxalate ions driven by the low concentrations of palladium, rhodium, and/or ruthenium in the waste. Variations in process conditions led to increases or decreases in the total oxidative destruction, as well as partially shifting the preferred species undergoing destruction from oxalate ion to formate ion.

  2. Treatment of toxic and hazardous organic wastes by wet oxidation process with oxygenated water at low temperature

    International Nuclear Information System (INIS)

    The wet oxidation process using air or molecular oxygen is a well-known process from long time. It is suitable to oxidize several types of waste refractory to the usual biological, thermal and chemical treatments. The drastic operating conditions (high pressures and temperatures) prevented its industrial development. In the last years a new interest was assigned to the process for the treatment of nuclear wastes (organic resins and exhaust organic wastes); the treatment is carried out at widely reduced operating conditions (atmospheric pressure and boiling temperature) by means of metallic catalysts and hydrogen peroxide. With some limits, the wet oxidation with hydrogen peroxide at low temperature can be applied to conventional waste waters containing toxic organic compounds. In the present report are summarized the activities developed at ENEA Fuel Cycle Department by the task force 'Deox' constituted by laboratory and plant specialists in order to verify the application of the wet oxidation process to the treatment of the toxic wastes. (author)

  3. Chemistry of materials relevant to aqueous reprocessing and waste management

    International Nuclear Information System (INIS)

    Nuclear energy option will be an inevitable one with the fossil fuels depleting fast and present coal and oil based thermal power generation resulting in unwanted green house gas emission. The utilisation of the fissile resources will be more effective with closed fuel cycle option wherein the spent reactor fuel is reprocessed and the unused uranium and plutonium formed during the reactor operation is recovered and re-used. Of the aqueous and non-aqueous routes available to reprocess the spent nuclear fuels, aqueous reprocessing method of recovering the valuable uranium and plutonium by the PUREX process is in vogue for the past six decades. The process involves chopping the fuel into small lengths, leaching uranium and plutonium with concentrated nitric acid under reflux, conditioning the dissolver solution with respect to acidity and valency of U and Pu, solvent extraction with 30%TBP/n-DD to selectively extract U(VI) and Pu(IV) leaving most of the fission products into the raffinate, partitioning plutonium from uranium and reconversion of U and Pu into oxide forms after further purification. Many reagents are used to achieve near quantitative recovery of both uranium and plutonium (>99.9%) and with high decontamination factors (>107) from highly radioactive fission products. Nevertheless, the chemistry of several reagents used and the chemical processes that take place during the entire course of reprocessing and waste management operations are yet to be fully understood and gives a lot of scope for further improvements. Some examples where research requires concerted efforts are, 1) development of new extractants conforming to CHON principle, with acceptable physical properties, high stability, selectivity and resistance to third phase formation, 2) new partitioning reagents and processes which offer good efficiency and kinetics for uranium/plutonium reduction, 3) understanding the chemistry of troublesome fission products such as Tc, Ru and Zr, 4

  4. Aqueous-Phase Reactions of Isoprene with Sulfoxy Radical Anions as a way of Wet Aerosol Formation in the Atmosphere

    Science.gov (United States)

    Kuznietsova, I.; Rudzinski, K. J.; Szmigielski, R.; Laboratory of the Environmental Chemistry

    2011-12-01

    Atmospheric aerosols exhibit an important role in the environment. They have implications on human health and life, and - in the larger scale - on climate, the Earth's radiative balance and the cloud's formation. Organic matter makes up a significant fraction of atmospheric aerosols (~35% to ~90%) and may originate from direct emissions (primary organic aerosol, POA) or result from complex physico-chemical processes of volatile organic compounds (secondary organic aerosol, SOA). Isoprene (2-methyl-buta-1,3-diene) is one of the relevant volatile precursor of ambient SOA in the atmosphere. It is the most abundant non-methane hydrocarbon emitted to the atmosphere as a result of living vegetation. According to the recent data, the isoprene emission rate is estimated to be at the level of 500 TgC per year. While heterogeneous transformations of isoprene have been well documented, aqueous-phase reactions of this hydrocarbon with radical species that lead to the production of new class of wet SOA components such as polyols and their sulfate esters (organosulfates), are still poorly recognized. The chain reactions of isoprene with sulfoxy radical-anions (SRA) are one of the recently researched route leading to the formation of organosulfates in the aqueous phase. The letter radical species originate from the auto-oxidation of sulfur dioxide in the aqueous phase and are behind the phenomenon of atmospheric acid rain formation. This is a complicated chain reaction that is catalyzed by transition metal ions, such as manganese(II), iron(III) and propagated by sulfoxy radical anions . The presented work addresses the chemical interaction of isoprene with sulfoxy radical-anions in the water solution in the presence of nitrite ions and nitrous acid, which are important trace components of the atmosphere. We showed that nitrite ions and nitrous acid significantly altered the kinetics of the auto-oxidation of SO2 in the presence of isoprene at different solution acidity from 2 to 8

  5. Development of a novel wet oxidation process for hazardous and mixed wastes

    International Nuclear Information System (INIS)

    Many DOE waste streams and remediates contain complex and variable mixtures of organic compounds, toxic metals, and radionuclides. These materials are often dispersed in organic or inorganic matrices, such as personal protective equipment, various sludges, soils, and water. The over all objective of the effort described here is to develop a novel catalytic wet oxidation process for the treatment of these multi-component wastes, with the aim of providing a versatile, non-thermal method which will destroy hazardous organic compounds while simultaneously containing and concentrating toxic and radioactive metals for recovery or disposal in a readily stabilized matrix. The DETOX process uses a unique combination of metal catalysts to increase the rate of oxidation of organic materials. The metal catalysts are in the form of salts dissolved in a dilute acid solution. A typical catalyst composition is 60% ferric chloride, 3--4% hydrochloric acid, 0.13% platinum ions, and 0.13% ruthenium ions in a water solution. The catalyst solution is maintained at 423--473 K. Wastes are introduced into contact with the solution, where their organic portion is oxidized to carbon dioxide and water. If the organic portion is chlorinated, hydrogen chloride will be produced as a product. The process is a viable alternative to incineration for the treatment of organic mixed wastes. Estimated costs for waste treatment using the process are from $2.50/kg to $25.00/kg, depending on the size of the unit and the amount of waste processed. Process units can be mobile for on-site treatment of wastes. Results from phase 1 and 2, design and engineering studies, are described

  6. Production of Smokeless Briquette Charcoals from Wet Cake Waste of Ethanol Industry

    Directory of Open Access Journals (Sweden)

    Walairat Uttamaprakrom

    2012-04-01

    Full Text Available The main aim of this research was to investigate proximate analysis and heating value of wet cake waste from ethanol industry to be used as alternative fuels by carbonization at 400, 450, 500 and 550 degrees, vary times 30, 45, 60 and 90 minutes in oxygen-limited conditions. The maximum yields and fixed carbon volume were observed to be evolving at 500c, 60 minutes. At condition has 1.17% moisture, 34.42% ash, 16.57% volatile matter and 47.84% fixed carbon respectively.Then bring wet cake waste to briquette charcoals by hot and cold compressed for utilization in industry and commercial. Found that heating value of hot and cold compressed were 20,257.25 KJ/kg and 24,790.21 KJ/kg,which are higher heating value after carbonization.There are also cost-benefit and cost-effectiveness analysis, hot compressed cost 0.17 baht/piece, total production at breakeven 704,225 pieces and payback period of 0.18 years, while cold compressed cost 0.3175 baht/piece, total production at breakeven 341,297 pieces and payback period of 0.17 years.

  7. Process optimization for effective column separation of 106Ru from aqueous waste associated with spent reprocessing solvent in storage tanks

    International Nuclear Information System (INIS)

    The present work deals with another waste stream resulting from reprocessing operations, viz. the aqueous solution present in substantial quantities as the bottom layer in tanks storing spent TBP-dodecane solvent. The effective separation of 106Ru from aqueous waste streams generated during reprocessing of spent nuclear fuel is difficult because of its complex aqueous chemistry

  8. Decomposition and Mineralization of Dimethyl Phthalate in an Aqueous Solution by Wet Oxidation

    Directory of Open Access Journals (Sweden)

    Dar-Ren Ji

    2015-01-01

    Full Text Available Dimethyl phthalate (DMP was treated via wet oxygen oxidation process (WOP. The decomposition efficiency ηDMP of DMP and mineralization efficiency ηTOC of total organic carbons were measured to evaluate the effects of operation parameters on the performance of WOP. The results revealed that reaction temperature T is the most affecting factor, with a higher T offering higher ηDMP and ηTOC as expected. The ηDMP increases as rotating speed increases from 300 to 500 rpm with stirring enhancement of gas liquid mass transfer. However, it exhibits reduction effect at 700 rpm due to purging of dissolved oxygen by overstirring. Regarding the effects of pressure PT, a higher PT provides more oxygen for the forward reaction with DMP, while overhigh PT increases the absorption of gaseous products such as CO2 and decomposes short-chain hydrocarbon fragments back into the solution thus hindering the forward reaction. For the tested PT of 2.41 to 3.45 MPa, the results indicated that 2.41 MPa is appropriate. A longer reaction time of course gives better performance. At 500 rpm, 483 K, 2.41 MPa, and 180 min, the ηDMP and ηTOC are 93 and 36%, respectively.

  9. Sorption Potentials of Waste Tyre for Some Heavy Metals (Pb Cd) in Aqueous Solution

    OpenAIRE

    Austin Kanayo ASIAGWU; Patrice-Anthony-Chudi OKOYE; Orji IFEOMA; Patrick Ejo OMUKU

    2009-01-01

    An investigation into the adsorption potential of activated and inactivated waste tyre powders for some heavy metals (Pb2+ and Cd2+) in their aqueous solution has been studied. The result indicated that inactivated waste tyre is a good non-conventional adsorbent for the removal of Cd from aqueous solution. A total of 93.3% of Cadmium contents was removed. The inactivated waste type proved a good adsorbent for the removal of Pb2+ 5g of 500mm activated tyre removed over 86.66% of Pb2+ from solu...

  10. Sorption Potentials of Waste Tyre for Some Heavy Metals (Pb Cd in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Austin Kanayo ASIAGWU

    2009-07-01

    Full Text Available An investigation into the adsorption potential of activated and inactivated waste tyre powders for some heavy metals (Pb2+ and Cd2+ in their aqueous solution has been studied. The result indicated that inactivated waste tyre is a good non-conventional adsorbent for the removal of Cd from aqueous solution. A total of 93.3% of Cadmium contents was removed. The inactivated waste type proved a good adsorbent for the removal of Pb2+ 5g of 500mm activated tyre removed over 86.66% of Pb2+ from solution.

  11. Investigations regarding the wet decontamination of fluorescent lamp waste using iodine in potassium iodide solutions

    International Nuclear Information System (INIS)

    Highlights: • A wet-based decontamination process for fluorescent lamp waste is proposed. • Mercury can be leached using iodine in potassium iodide solution. • The efficiency of the process increases with an increase in leachant concentration. • Selective leaching of mercury from rare earth elements is achieved. • Mercury is furthered recovered using ion exchange, reduction or solvent extraction. - Abstract: With the rising popularity of fluorescent lighting, simple and efficient methods for the decontamination of discarded lamps are needed. Due to their mercury content end-of-life fluorescent lamps are classified as hazardous waste, requiring special treatment for disposal. A simple wet-based decontamination process is required, especially for streams where thermal desorption, a commonly used but energy demanding method, cannot be applied. In this study the potential of a wet-based process using iodine in potassium iodide solution was studied for the recovery of mercury from fluorescent lamp waste. The influence of the leaching agent’s concentration and solid/liquid ratio on the decontamination efficiency was investigated. The leaching behaviour of mercury was studied over time, as well as its recovery from the obtained leachates by means of anion exchange, reduction, and solvent extraction. Dissolution of more than 90% of the contained mercury was achieved using 0.025/0.05 M I2/KI solution at 21 °C for two hours. The efficiency of the process increased with an increase in leachant concentration. 97.3 ± 0.6% of the mercury contained was dissolved at 21 °C, in two hours, using a 0.25/0.5 M I2/KI solution and a solid to liquid ratio of 10% w/v. Iodine and mercury can be efficiently removed from the leachates using Dowex 1X8 anion exchange resin or reducing agents such as sodium hydrosulphite, allowing the disposal of the obtained solution as non-hazardous industrial wastewater. The extractant CyMe4BTBP showed good removal of mercury, with an

  12. Final Treatment Center Project for Liquid and Wet Radioactive Waste in Slovakia

    International Nuclear Information System (INIS)

    The Final Treatment Center (FTC) for Mochovce nuclear power plant (NPP) is designed for treatment and final conditioning of radioactive liquid and wet waste produced from plant operation. Mochovce NNP uses a Russian VVER-440 type reactor. Treated wastes comprise radioactive concentrates, spent resin and sludge. VUJE Inc. as an experienced company in field of treatment of radioactive waste in Slovakia has been chosen as main contractor for technological part of FTC. This paper describes the capacity, flow chart, overall waste flow and parameters of the main components in the FTC. The initial project was submitted for approval to the Slovak Electric plc. in 2003. The design and manufacture of main components were performed in 2004 and 2005. FTC construction work started early in 2004. Initial non-radioactive testing of the system is planned for summer 2006 and then radioactive tests are to be followed. A one-year trial operation of facility is planned for completion in 2007. SE - VYZ will be operates the FTC during trial operation and after its completion. SE - VYZ is subsidiary company of Slovak Electric plc. and it is responsible for treatment with radioactive waste and spent fuel in the Slovak republic. SE - VYZ has, besides of other significant experience with operation of Jaslovske Bohunice Treatment Centre. The overall capacity of the FTC is 870 m3/year of concentrates and 40 m3/year of spent resin and sludge. Bituminization and cementation were provided as main technologies for treatment of these wastes. Treatment of concentrate is performed by bituminization. Concentrate and bitumen are metered into a thin film evaporator with rotating wiping blades. Surplus water is evaporated and concentrate salts are embedded in bitumen. Bitumen product is discharged into 200 l steel drums. Spent resin and sludge are decanted, dried and mixed with bitumen. These mixtures are also discharged into 200 l steel drums. Drums are moved along bituminization line on a roller

  13. Enhancing denitrification using a carbon supplement generated from the wet oxidation of waste activated sludge.

    Science.gov (United States)

    Strong, P J; McDonald, B; Gapes, D J

    2011-05-01

    This study compared the effect of four pure carbon supplements on biological denitrification to a liquor derived as a by-product from the wet oxidation (WO) of waste activated sludge. Sequencing batch reactors were used to acclimate sludge biomass, which was used in batch assays. Acetate, WO liquor and ethanol-supplementation generated the fastest denitrification rates. Acetate and WO liquor were efficiently utilised by all acclimated biomass types, while poor rates were achieved with methanol and formate. When comparing an inoculum from an ethanol-supplemented and non-supplemented wastewater treatment plant (WWTP), the ethanol-acclimated sludge obtained superior denitrification rates when supplemented with ethanol. Similarly high nitrate removal rates were achieved with both sludge types with acetate and WO liquor supplementation, indicating that WO liquors could achieve excellent rates of nitrate removal. The performance of the WO liquor was attributed to the variety of organic carbon substrates (particularly acetic acid) present within the liquor. PMID:21196117

  14. Financial appraisal of wet mesophilic AD technology as a renewable energy and waste management technology

    International Nuclear Information System (INIS)

    Anaerobic digestion (AD) has the potential to support diversion of organic waste from landfill and increase renewable energy production. However, diffusion of this technology has been uneven, with countries such as Germany and Sweden taking the lead, but limited diffusion in other countries such as the UK. In this context, this study explores the financial viability of AD in the UK to offer reasons why it has not been more widely used. This paper presents a model that calculates the Internal Rate of Return (IRR) on a twenty year investment in a 30,000 tonnes per annum wet mesophilic AD plant in the UK for the treatment of source separated organic waste, which is judged to be a suitable technology for the UK climate. The model evaluates the financial significance of the different alternative energy outputs from this AD plant and the resulting economic subsidies paid for renewable energy. Results show that renewable electricity and renewable heat sales supported by renewable electricity and renewable heat tariffs generates the greatest IRR (31.26%). All other uses of biogas generate an IRR in excess of 15%, and are judged to be a financially viable investment. Sensitivity analysis highlights the financial significance of: economic incentive payments and a waste management gate fee; and demonstrates that the fate of the digestate by-product is a source of financial uncertainty for AD investors. - Research highlights: → Diffusion of AD technology is less rapid in the UK than other EU countries. → UK AD is financially viable if the energy output is supported by government subsidy. → Sensitivity analysis highlights the financial need for a waste management gate fee. → Digestate by-product creates a significant financial uncertainty for AD investors.

  15. Wet oxidation treatment of organic household waste enriched with wheat straw for simultaneous saccharification and fermentation into ethanol

    DEFF Research Database (Denmark)

    Lissens, G.; Klinke, H.B.; Verstraete, W.;

    2004-01-01

    Organic municipal solid waste enriched with wheat straw was subjected to wet-oxidation as a pre-treatment for subsequent enzymatic conversion and fermentation into bio-ethanol. The effect of tempera (185-195degrees C), oxygen pressure (3-12) and sodium carbonate (0-2 g l(-1)) addition on enzymati...

  16. Wet oxidation pre-treatment of woody yard waste: Parameter optimization and enzymatic digestibility for ethanol production

    DEFF Research Database (Denmark)

    Lissens, G.; Klinke, H.B.; Verstraete, W.;

    2004-01-01

    Woody yard waste with high lignin content (22% of dry matter (DM)) was subjected to wet oxidation pre-treatment for subsequent enzymatic conversion and fermentation. The effects of temperature (185-200 degreesC), oxygen pressure (3-12 bar) and addition of sodium carbonate (0-3.3 g per 100 g DM bi...

  17. Effects of aqueous environment on long-term durability of phosphate-bonded ceramic waste forms

    International Nuclear Information System (INIS)

    Over the last few years, Argonne National Laboratory has been developing room-temperature-setting chemically-bonded phosphate ceramics for solidifying and stabilizing low-level mixed wastes. This technology is crucial for stabilizing waste streams that contain volatile species and off-gas secondary waste streams generated by high-temperature treatment of such wastes. Magnesium phosphate ceramic has been developed to treat mixed wastes such as ash, salts, and cement sludges. Waste forms of surrogate waste streams were fabricated by acid-base reactions between the mixtures of magnesium oxide powders and the wastes, and phosphoric acid or acid phosphate solutions. Dense and hard ceramic waste forms are produced in this process. The principal advantage of this technology is that the contaminants are immobilized by both chemical stabilization and subsequent microencapsulation of the reaction products. This paper reports the results of durability studies conducted on waste forms made with ash waste streams spiked with hazardous and radioactive surrogates. Standard leaching tests such as ANS 16.1 and TCLP were conducted on the final waste forms. Fates of the contaminants in the final waste forms were established by electron microscopy. In addition, stability of the waste forms in aqueous environments was evaluated with long-term water-immersion tests

  18. Measurement and Monte Carlo Calculation of Waste Drum Filled With Radioactive Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    XU; Li-jun; ZHANG; Wei-dong; YE; Hong-sheng; LIN; Min; CHEN; Xi-lin; GUO; Xiao-qing

    2012-01-01

    <正>Theoretically the best calibrating source of gamma scan system (SGS) is a waste drum filled with uniform distribution of medium and radioactive nuclides. However, in reality, waste drums usually full of solid substance, which are difficult to be prepared in a completely uniformly distributed state. To reduce measurement uncertainty of the radioactivity of waste drums prepared using the method of shell source, a waste drum filled with radioactive aqueous solution was prepared. Besides, its radioactivity was measured by a SGS device and calculated using Monte Carlo method to verify the exact geometric model, which

  19. Physical property parameter set for modeling ICPP aqueous wastes with ASPEN electrolyte NRTL model

    International Nuclear Information System (INIS)

    The aqueous waste evaporators at the Idaho Chemical Processing Plant (ICPP) are being modeled using ASPEN software. The ASPEN software calculates chemical and vapor-liquid equilibria with activity coefficients calculated using the electrolyte Non-Random Two Liquid (NRTL) model for local excess Gibbs free energies of interactions between ions and molecules in solution. The use of the electrolyte NRTL model requires the determination of empirical parameters for the excess Gibbs free energies of the interactions between species in solution. This report covers the development of a set parameters, from literature data, for the use of the electrolyte NRTL model with the major solutes in the ICPP aqueous wastes

  20. Immobilization of Rose Waste Biomass for Uptake of Pb(II) from Aqueous Solutions

    OpenAIRE

    Raziya Nadeem; Muhammad Aslam Khan; Uzma Ijaz; Abida Mahmood; Muhammad Asif Hanif; Tariq Mahmood Ansari; Muhammad Ali

    2011-01-01

    Rosa centifolia and Rosa gruss an teplitz distillation waste biomass was immobilized using sodium alginate for Pb(II) uptake from aqueous solutions under varied experimental conditions. The maximum Pb(II) adsorption occurred at pH 5. Immobilized rose waste biomasses were modified physically and chemically to enhance Pb(II) removal. The Langmuir sorption isotherm and pseudo-second-order kinetic models fitted well to the adsorption data of Pb(II) by immobilized Rosa centifolia and Rosa gruss an...

  1. Stabilization of Savannah River National Laboartory (SRNL) Aqueous Waste by Fluidized Bed Steam Reforming (FBSR)

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C

    2004-11-01

    The Savannah River National Laboratory (SRNL) is a multidisciplinary laboratory operated by Westinghouse Savannah River Company (WSRC) in Aiken, South Carolina. Research and development programs have been conducted at SRNL for {approx}50 years generating non-radioactive (hazardous and non-hazardous) and radioactive aqueous wastes. Typically the aqueous effluents from the R&D activities are disposed of from each laboratory module via the High Activity Drains (HAD) or the Low Activity Drains (LAD) depending on whether they are radioactive or not. The aqueous effluents are collected in holding tanks, analyzed and shipped to either H-Area (HAD waste) or the F/H Area Effluent Treatment Facility (ETF) (LAD waste) for volume reduction. Because collection, analysis, and transport of LAD and HAD waste is cumbersome and since future treatment of this waste may be curtailed as the F/H-Area evaporators and waste tanks are decommissioned, SRNL laboratory operations requested several proof of principle demonstrations of alternate technologies that would define an alternative disposal path for the aqueous wastes. Proof of principle for the disposal of SRNL HAD waste using a technology known as Fluidized Bed Steam Reforming (FBSR) is the focus of the current study. The FBSR technology can be performed either as a batch process, e.g. in each laboratory module in small furnaces with an 8'' by 8'' footprint, or in a semi-continuous Bench Scale Reformer (BSR). The proof of principle experiments described in this study cover the use of the FBSR technology at any scale (pilot or full scale). The proof of principle experiments described in this study used a non-radioactive HAD simulant.

  2. investigations for the separation of radioisotopes and selected metal ions from dilute aqueous solutions and aqueous waste simulant by foaming

    International Nuclear Information System (INIS)

    co precipitate flotation (CPF) investigations show that cesium can be efficiently separated from aqueous solutions by coprecipitation with zine hexacyanoferrate (II) (ZnHCF) and subsequent flotation of the precipitate . collectors of different types were tested but cetyl pyridinium chloride showed the best performance. before undertaking the flotation investigations , coprecipitation of Cs with ZnHCF was studied to determine the optimal coprecipitation conditions. the developed CPF process was applied successfully for 137Cs removal from process wastewater and low level liquid radioactive waste simulant. the obtained results compare favourably with data published for cesium removal by coprecipitation or adsorption processes. besides, CPF seems to be more advantageous

  3. Study of aqueous process using hydrochloric acid for radioactive waste including uranium

    International Nuclear Information System (INIS)

    A lot of solid and liquid radioactive wastes had been produced in the various examinations. The wastes have been stored in Japan Nuclear Cycle Development Institute Ningyo-Toge Environmental Engineering Center. Amounts of solid wastes including fluorine and uranium are very much, so techniques of final disposal will be developed and the solid wastes will be disposed. This study estimates the applicability of aqueous process using hydrochloric acid for CaF2, NaF, Al2O3 and UF4, so examinations using those wastes were performed and mass balance and activity balance sheets were made. The conclusion is as below. 1. The process using hydrochloric acid to CaF2 is applicable. 2. The process using hydrochloric acid to NaF is applicable. 3. Dissolution of Al2O3 is difficult, but uranium in Al2O3 is almost dissolved, so application of aqueous process using hydrochloric acid for Al2O3 is possible. 4. Application of aqueous process using hydrochloric acid to UF4 has problem of insolubility of UF4. 5. Next subjects are a rise of solid/liquid ratio, a increase of efficiency of uranium precipitation and decrease of second wastes which are resins and aluminium as masking material to fluorine. (author)

  4. THE DEVELOPMENT OF AQUEOUS THERMODYNAMIC MODELS: APPLICATION TO WASTE TANK PROCESSING AND VADOSE ZONE ISSUES

    Science.gov (United States)

    The presence of a wide range of radionuclides, metal ions, inorganic ligands, and organic chelating agents combined with the high base and electrolyte concentration in the Hanford waste tanks creates some unique and difficult problems in modeling the aqueous thermodynamics of the...

  5. Application of insoluble tannin adsorbent to alpha aqueous waste treatment in NUCEF

    International Nuclear Information System (INIS)

    The use of insoluble tannin adsorbent has been investigated as a means to reduce the volume of aqueous waste contaminated with americium. This work is aimed at reducing the volume of TRU waste generated within NUCEF where experiments related to back end of the nuclear fuel cycle are performed. Insoluble tannin adsorbent is a gelled material consisting of C, H and O which can be easily incinerated. The distribution coefficient and adsorption capacity of americium in insoluble tannin have been investigated and found to be 1000 ml/g in 0.02 M HNO3 and 0.013 mmol/g-dried tannin, respectively. The prospect of applying the adsorbent to the treatment of aqueous waste contaminated with americium appears promising. (author)

  6. Prospects for using a full-scale installation for wet combustion of organic wastes in closed life support systems

    Science.gov (United States)

    Trifonov, Sergey V.; Kudenko, Yurii A.; Tikhomirov, Alexander A.

    2015-11-01

    The issue of recycling organic wastes in closed life support systems (CLSS) includes both fundamental aspects of environmental safety of the recycled products and their effective involvement in material cycles and technical aspects related to the structure of the system and the crew's demands. This study estimates the effectiveness of wet combustion of different amounts of organic wastes in hydrogen peroxide under application of an alternating current electric field. The study also addresses the possibility of controlling the process automatically. The results show that processing of greater amounts of wastes reduces specific power consumption and shortens the duration of the process, without significantly affecting the level of oxidation of the products. An automatic control system for a semi-commercial installation has been constructed and tested experimentally. The solution of mineralized human wastes prepared in the automatically controlled process in this installation was successfully used to grow radish plants, with the main production parameters being similar to those of the control.

  7. Prospects for using a full-scale installation for wet combustion of organic wastes in closed life support systems.

    Science.gov (United States)

    Trifonov, Sergey V; Kudenko, Yurii A; Tikhomirov, Alexander A

    2015-11-01

    The issue of recycling organic wastes in closed life support systems (CLSS) includes both fundamental aspects of environmental safety of the recycled products and their effective involvement in material cycles and technical aspects related to the structure of the system and the crew's demands. This study estimates the effectiveness of wet combustion of different amounts of organic wastes in hydrogen peroxide under application of an alternating current electric field. The study also addresses the possibility of controlling the process automatically. The results show that processing of greater amounts of wastes reduces specific power consumption and shortens the duration of the process, without significantly affecting the level of oxidation of the products. An automatic control system for a semi-commercial installation has been constructed and tested experimentally. The solution of mineralized human wastes prepared in the automatically controlled process in this installation was successfully used to grow radish plants, with the main production parameters being similar to those of the control. PMID:26553633

  8. Wet oxidation treatment of organic household waste enriched with wheat straw for simultaneous saccharification and fermentation into ethanol

    DEFF Research Database (Denmark)

    Lissens, G.; Klinke, H.B.; Verstraete, W.; Ahring, Birgitte Kiær; Thomsen, Anne Belinda

    2004-01-01

    -toxic carboxylic acids mainly (2.2-4.5 % on DS basis). Simultaneous saccharification and fermentation (SSF) of the treated waste at 10% DS by Saccharomyces cerevisae yielded average ethanol concentrations of 16.5 to 22 g l(-1) for enzyme loadings of 5 and 25 FPU g(-1) DS, respectively. The cellulose to ethanol...... conversion efficiency during SSF was 50, 62 65 and 70% for a total enzyme loading of 5, 10, 15 and 25 FPU g(-1) DS, respectively. Hence, this study shows that wet oxidation is a suitable pre-treatment for the conversion of organic waste carbohydrates into ethanol and that compatible conversion yields (60...

  9. Development of the Monolith Froth Reactor for Catalytic Wet Oxidation of CELSS Model Wastes

    Science.gov (United States)

    Abraham, Martin; Fisher, John W.

    1995-01-01

    The aqueous phase oxidation of acetic acid, used as a model compound for the treatment of CELSS (Controlled Ecological Life Support System) waste, was carried out in the monolith froth reactor which utilizes two-phase flow in the monolith channels. The catalytic oxidation of acetic acid was carried out over a Pt/Al2O3 catalyst, prepared at The University of Tulsa, at temperatures and pressures below the critical point of water. The effect of externally controllable parameters (temperature, liquid flow rate, distributor plate orifice size, pitch, and catalyst distance from the distributor plate) on the rate of acetic acid oxidation was investigated. Results indicate reaction rate increased with increasing temperature and exhibited a maximum with respect to liquid flow rate. The apparent activation energy calculated from reaction rate data was 99.7 kJ/mol. This value is similar to values reported for the oxidation of acetic acid in other systems and is comparable to intrinsic values calculated for oxidation reactions. The kinetic data were modeled using simple power law kinetics. The effect of "froth" feed system characteristics was also investigated. Results indicate that the reaction rate exhibits a maximum with respect to distributor plate orifice size, pitch, and catalyst distance from the distributor plate. Fundamental results obtained were used to extrapolate where the complete removal of acetic acid would be obtained and for the design and operation of a full scale CELSS treatment system.

  10. Solvent extraction of radionuclides from aqueous tank waste

    Energy Technology Data Exchange (ETDEWEB)

    Bonnesen, P.; Sachleben, R.; Moyer, B. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    The purpose of this task is to develop an efficient solvent-extraction and stripping process to remove the fission products {sup 99}Tc, {sup 90}Sr, and {sup 137}Cs from alkaline tank waste, such as those stored at Hanford and Oak Ridge. As such, this task expands on FY 1995`s successful development of a solvent-extraction and stripping process for technetium separation from alkaline tank-waste solutions. This process now includes the capability of removing both technetium and strontium simultaneously. In this form, the process has been named SRTALK and will be developed further in this program as a prelude to developing a system capable of removing technetium, strontium, and cesium.

  11. Low-temperature catalytic gasification of wet industrial wastes. FY 1991--1992 interim report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.C.; Neuenschwander, G.G.; Hart, T.R.; Phelps, M.R.; Sealock, L.J. Jr.

    1993-07-01

    A catalytic gasification system operating in a pressurized water environment has been developed and refined at Pacific Northwest Laboratory (PNL) for over 12 years. Initial experiments were aimed at developing kinetics information for steam gasification of biomass in the presence of catalysts. The combined use of alkali and metal catalysts was reported for gasification of biomass and its components at low temperatures (350{degrees}C to 450{degrees}C). From the fundamental research evolved the concept of a pressurized, catalytic gasification system for converting wet biomass feedstocks to fuel gas. Extensive batch reactor testing and limited continuous reactor system (CRS) testing were undertaken in the development of this system under sponsorship of the US Department of Energy. A wide range of biomass feedstocks were tested, and the importance of the nickel metal catalyst was identified. Specific use of this process for treating food processing wastes was also studied. The concept application was further expanded to encompass cleanup of hazardous wastewater streams, and results were reported for batch reactor tests and continuous reactor tests. Ongoing work at PNL focuses on refining the catalyst and scaling the system to long-term industrial needs. The process is licensed as the Thermochemical Environmental Energy System (TEES{reg_sign}) to Onsite*Ofsite, Inc., of Duarte, California. This report is a follow-on to the 1989--90 interim report [Elliott et al. 1991], which reviewed the results of the studies conducted with a fixed-bed, continuous-feed, tubular reactor. The discussion here provides an overview of experiments on the wide range of potential feedstock materials conducted in a batch reactor; development of new catalyst materials; and tests performed in continuous-flow reactors at three scales. The appendices contain the history and background of the process development, as well as more detailed descriptions and results of the recent studies.

  12. Degradation of H-acid in aqueous solution by microwave assisted wet air oxidation using Ni-loaded GAC as catalyst

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yao-bin; QUAN Xie; ZHAO Hui-min; CHEN Shuo; YANG Feng-lin

    2005-01-01

    A novel process, microwave assisted catalytic wet air oxidation(MW-CWO), was applied for the degradation of H-acid( 1-amino8-naphthol-3, 6-disulfonic acid) in aqueous solution. Ni-loaded granular activated carbon (GAG), prepared by immersion-calcination method, was used as catalyst. The results showed that the MW-CWO process was very effective for the degradation of H-acid in aqueous solution under atmospheric pressure with 87.4% TOC (total organic carbon) reduction in 20 min. Ni on GAC existed in the form of NiO as specified by XRD. Loss of Ni was significant in the initial stage, and then remained almost constant after 20 min reaction. BET surface area results showed that the surface property of GAC after MW-CWO process was superior to that of blank GAC.

  13. Characterization of microbial and chemical composition of shuttle wet waste with permanent gas and volatile organic compound analyses

    Science.gov (United States)

    Peterson, B. V.; Hummerick, M.; Roberts, M. S.; Krumins, V.; Kish, A. L.; Garland, J. L.; Maxwell, S.; Mills, A.

    2004-01-01

    Solid-waste treatment in space for Advanced Life Support, ALS, applications requires that the material can be safely processed and stored in a confined environment. Many solid-wastes are not stable because they are wet (40-90% moisture) and contain levels of soluble organic compounds that can contribute to the growth of undesirable microorganisms with concomitant production of noxious odors. In the absence of integrated Advanced Life Support systems on orbit, permanent gas, trace volatile organic and microbiological analyses were performed on crew refuse returned from the volume F "wet" trash of three consecutive Shuttle missions (STS-105, 109, and 110). These analyses were designed to characterize the short-term biological stability of the material and assess potential crew risks resulting from microbial decay processes during storage. Waste samples were collected post-orbiter landing and sorted into packaging material, food waste, toilet waste, and bulk liquid fractions deposited during flight in the volume F container. Aerobic and anaerobic microbial loads were determined in each fraction by cultivation on R2A and by acridine orange direct count (AODC). Dry and ash weights were performed to determine both water and organic content of the materials. Experiments to determine the aerobic and anaerobic biostability of refuse stored for varying periods of time were performed by on-line monitoring of CO2 and laboratory analysis for production of hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA Method TO15 by USEPA et al. [EPA Method TO15, The Determination of Volatile Organic Compounds (VOCs) in Ambient Air using SUMMA, Passivated Canister Sampling and Gas Chromatographic Analysis,1999] with gas chromatography/mass spectrometry and by gas chromatography with selective detectors. These baseline measures of waste stream content, labile organics, and microbial load in the volume F Shuttle trash provide data for waste

  14. Characterization of microbial and chemical composition of shuttle wet waste with permanent gas and volatile organic compound analyses

    Science.gov (United States)

    Peterson, B. V.; Hummerick, M.; Roberts, M. S.; Krumins, V.; Kish, A. L.; Garland, J. L.; Maxwell, S.; Mills, A.

    2004-01-01

    Solid-waste treatment in space for Advanced Life Support, ALS, applications requires that the material can be safely processed and stored in a confined environment. Many solid-wastes are not stable because they are wet (40-90% moisture) and contain levels of soluble organic compounds that can contribute to the growth of undesirable microorganisms with concomitant production of noxious odors. In the absence of integrated Advanced Life Support systems on orbit, permanent gas, trace volatile organic and microbiological analyses were performed on crew refuse returned from the volume F "wet" trash of three consecutive Shuttle missions (STS-105, 109, and 110). These analyses were designed to characterize the short-term biological stability of the material and assess potential crew risks resulting from microbial decay processes during storage. Waste samples were collected post-orbiter landing and sorted into packaging material, food waste, toilet waste, and bulk liquid fractions deposited during flight in the volume F container. Aerobic and anaerobic microbial loads were determined in each fraction by cultivation on R2A and by acridine orange direct count (AODC). Dry and ash weights were performed to determine both water and organic content of the materials. Experiments to determine the aerobic and anaerobic biostability of refuse stored for varying periods of time were performed by on-line monitoring of CO 2 and laboratory analysis for production of hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA Method TO15 by USEPA et al. [EPA Method TO15, The Determination of Volatile Organic Compounds (VOCs) in Ambient Air using SUMMA, Passivated Canister Sampling and Gas Chromatographic Analysis, 1999] with gas chromatography/mass spectrometry and by gas chromatography with selective detectors. These baseline measures of waste stream content, labile organics, and microbial load in the volume F Shuttle trash provide data for waste

  15. Sorption of 137Cs from Aqueous Waste Solutions using Pottery

    International Nuclear Information System (INIS)

    A simple and inexpensive method for sorption of 137Cs from aqueous solutions using a highly available vase shape pottery material has been investigated. Porosity of the used pottery allowed for the penetration of the radioactive solution through its permeable body. Two routes had been investigated for cesium removal from the radioactive solutions. In the first one, pottery bodies were immersed into the radioactive solutions. In the second method; the radioactive solutions were filled the inner volumes of the pottery bodies. Vase shape pottery showed higher sorption capability for 137Cs much more than its powder forms, especially in the alkaline medium. Pottery bodies showed high potential for 137Cs removal. Adsorption isotherms revealed good lit to the Freundlich and Langumir isotherms. During sorption processes outside and inside the pottery body, 137Cs was well captured inside the amorphous microstructure of the pottery body. In this respect, micro filtration of cesium radionuclides through the used pottery could be postulated. Desorption experiments indicated higher immobilization affinity for radiocesium into pottery bodies, which indicates a high containment for 137Cs with an irreversible fixation mechanism

  16. Radiation-flotation purification of aqueous wastes from mercury

    International Nuclear Information System (INIS)

    Purification of industrial wastes of plants producing chlorine and alkalies by electrolysis with using metallic mercury as a cathode from mercury (in ionic and metallic form as well as in the form of precipitate) to the accepted in the Soviet Union limiting permitted level of concentration (5 x 10-3 mg dm-3) by routine sulphide and ion exchange methods has some disadvantages. We have now developed the radiation-flotation method which consists of three stages: preliminary flotation in the presence of surfactant (sodium alkylsulphonate), γ-irradiation at dose 1 kGy and secondary flotation (also in the presence of sodium alkylsulphonate). The method is discussed and results are reported. (author)

  17. Heterogeneous Photo catalytic Degradation of Hazardous Waste in Aqueous Suspension

    International Nuclear Information System (INIS)

    The photo catalytic degradation of hazardous waste like chlorinated paraffin compound (1,12-Dichlorodoecane Ded) was investigated in different aquatic media using GC-MSD. The direct photolysis of Ded in HPLC water was considered to be negligible (k = 0.0020+-0.0007h-1). An acceleration of the photodegradation rate was occurred in presence of different TiO2 catalyst systems. Molecular oxygen was found to play a vital role in the degradation process. Anatase TiO2 was proved to be the most efficient one (k=0.7670+-0.0876h-1), while the rate constant of the rutile TiO2 was calculated to be 0.2780+-0.0342h-1. Improvement of photo catalytic efficiency of rutile TiO2 was achieved by addition of Fe+2 giving a rate constant =0.6710+-0.0786h-1

  18. Simultaneous treatment of NO and SO2 with aqueous NaClO2 solution in a wet scrubber combined with a plasma electrostatic precipitator

    International Nuclear Information System (INIS)

    Highlights: • This study was conducted to investigate simultaneous removal of NO and SO2. • Proposed process consists of wet chemical reactor and non-thermal plasma reactor. • In the wet chemical reactor, NO and SO2 were absorbed and oxidized by NaClO2. • In the non-thermal plasma reactor, aerosol particles were collected on anode surface. • NO and SO2 were removed more efficiently by proposed process than other methods. - Abstract: NO and SO2 gases that are generally produced in thermal power plants and incinerators were simultaneously removed by using a wet scrubber combined with a plasma electrostatic precipitator. The wet scrubber was used for the absorption and oxidation of NO and SO2, and non-thermal plasma was employed for the electrostatic precipitation of aerosol particles. NO and SO2 gases were absorbed and oxidized by aerosol particles of NaClO2 solution in the wet scrubber. NO and SO2 reacted with the generated NaClO2 aerosol particles, NO2 gas, and aqueous ions such as NO2−, NO3−, HSO3−, and SO42−. The aerosol particles were negatively charged and collected on the surface of grounded anode in the plasma electrostatic precipitator. The NO and SO2 removal efficiencies of the proposed system were 94.4% and 100% for gas concentrations of 500 mg/m3 and a total gas flow rate of 60 Nm3/h, when the molar flow rate of NaClO2 and the gas–liquid contact time were 50 mmol/min and 1.25 s, respectively. The total amount and number of aerosol particles in the exhaust gas were reduced to 7.553 μg/m3 and 210 /cm3 at the maximum plasma input power of 68.8 W, which are similar to the values for clean air

  19. Biodenitrification of gaseous diffusion plant aqueous wastes: stirred bed reactor

    International Nuclear Information System (INIS)

    Approximately 30 kilograms of nitrates per day are discarded in the raffinates (acid wastes) of the Portsmouth Gaseous Diffusion Plant's X-705 Uranium Recovery and Decontamination Facility. A biodenitrification process employing continuous-flow, stirred-bed reactors has been successfully used to remove nitrates from similar acid wastes at the Oak Ridge Y-12 Plant. Laboratory studies have been made at Portsmouth to characterize the X-705 raffinates and to test the stirred-bed biodenitrification process on such raffinates. Raffinates which had been previously characterized were pumped through continuous-flow, stirred-bed, laboratory-scale reactors. Tests were conducted over a period of 146 days and involved variations in composition, mixing requirements, and the fate of several metal ions in the raffinates. Tests results show that 20 weight percent nitrates were reduced to a target nitrate effluent concentration of 100 μg/ml with a 99.64 percent efficiency. However, the average denitrification rate achieved was only 33% of that demonstrated with the Y-12 stirred-bed system. These low rates were probably due to the toxic effects of heavy metal ions on the denitrifying bacteria. Also, most of the uranium in the raffinate feed remained in the biomass and calcite, which collected in the reactor. This could cause criticality problems. For these reasons, it was decided not to make use of the stirred-bed bioreactor at Portsmouth. Instead, the biodenitrification installation now planned will use fluidized bed columns whose performance will be the subject of a subsequent report

  20. Chemical treatment of aqueous radioactive Cesium-137 waste using Ferri Chloride

    International Nuclear Information System (INIS)

    Ferric Chloride 6H2O was used for treatment of liquid radioactive wastes containing Cesium-137. Various concentration of ferric chloride 6H2O have been added into the waste at different pH and speed of stirrer. The treatment was based on the coagulans-flocculation and coprecipitation mechanisms. The best result of this experiment was achieved by adding 300 ppm of Ferric chloride 6 H2O into liquid waste on following condition the rate Stirrer was 250 rpm. At this condition, it was found that the separation efficiency and the decontamination factor were 83.32 % and 5.99. The activity of decreasing of aqueous radioactive Cesium-137 waste was 2.10 x 10-4 Ci/l to 3.50 x 10-5 Ci/l

  1. Chemical treatment of secondary waste solutions resulting from wet oxidative degradation of spent ion-exchange resins

    International Nuclear Information System (INIS)

    The present experimental work has been carried out to evaluate the chemical treatment process of radioactive secondary waste solutions resulting from the wet oxidative degradation of simulated spent radioactive cation-exchange resins using hydrogen peroxide as oxidant. The present study aims mainly to evaluate the ability of ferrocyanide compound of nickel for selective fixation of radio-cesium from the secondary waste solution in presence of traces of soluble organic residues. Based on the data obtained, it was found that, using 5 x 10-3 of nickel ferrocyanide, at ph range from 1-9 and in the presence of traces of soluble organic carbon, more than 99% of the radiocesium initially found could be efficiently removed from the secondary radioactive waste solutions under consideration

  2. Evaluation of thin-film evaporation for decontamination and immobilization of aqueous nuclear waste

    International Nuclear Information System (INIS)

    In the early 1980's, AECL, at the Chalk River Laboratory (CRL) site, built a Waste Treatment Centre (WTC) for managing low level solid and aqueous liquid wastes. The objective was to demonstrate processes for converting Canadian Deuterium Uranium (CANDU) waste to a form suitable for disposal while meeting or exceeding current environmental regulations. At present, two liquid waste streams are being treated at the Waste Treatment Centre. The liquid waste streams are volume reduced by a combination of continuous crossflow microfiltration (MF), spiral wound reverse osmosis (SWRO), and tubular reverse osmosis (TRO) membrane technologies [1]. The solutions are evaporated while simultaneously adding bitumen in a thin-film evaporator. A water-free product of chemical and radiochemical salts and bitumen is removed in 200 L galvanized steel drums for storage and eventual disposal in the CRL Waste Management Area. The feed stream to the thin-film evaporator typically has a β/γ activity of about 1 - 3 μCi/mL. This intermediate-level radioactive stream is concentrated by a factor of about 10, while simultaneously being immobilized. The radiation field of product drums on contact typically has a value of 0.5 to 3 R/h depending upon the feed concentration of radioactivity to the evaporator. The total solids content in the 200 L drum ranges from 25% to 35%. Encapsulated in the bitumen matrix are a variety of non-radiochemical salts (including sodium phosphate, sodium sulphate, and sodium carbonate) which comprise the bulk of the total solids in the product drum. The drum contains less than 1% of free water. The paper will discuss the volume reduction capability of the plant, with an emphasis on the immobilization of the aqueous waste with bitumen in a thin-film evaporator. Operations experience gained from over 200 campaigns is documented in the paper. (author)

  3. Degradation of Refractory Organic Compounds in Aqueous Wastes employing a combination of biological and chemical treatments

    OpenAIRE

    Chindris, Anuta

    2011-01-01

    In this study the removal of refractory organic compounds (ROCs) in Aqueous Wastes (AW) employing a combination of biological and chemical treatment were investigated at Department of Chemical Engineering and Materials Science, University of Cagliari, Italy and Department of Engineering, Oxford University, UK. The main objectives were to stimulate and optimise the degradation of ROCs with efficient removal of them in AW. This project is divided in two sections, a theoreti...

  4. Removal and recovery of toxic metal ions from aqueous waste sites using polymer pendant ligands

    Energy Technology Data Exchange (ETDEWEB)

    Fish, D. [Lawrence Berkeley National Lab., CA (United States)

    1996-10-01

    The purpose of this project is to investigate the use of polymer pendant ligand technology to remove and recover toxic metal ions from DOE aqueous waste sites. Polymer pendant lgiands are organic ligands, anchored to crosslinked, modified divinylbenzene-polystyrene beads, that can selectively complex metal ions. The metal ion removal step usually occurs through a complexation or ion exchange phenomena, thus recovery of the metal ions and reuse of the beads is readily accomplished.

  5. A Low Level Radioactivity Monitor for Aqueous Waste

    International Nuclear Information System (INIS)

    A system is described for continuous monitoring of very low levels of radioactivity in waste water containing typically 3.5 g/l dissolved solids. Spray evaporation of the water enables the dissolved solids to be recovered in the form of an aerosol and collected on a filter tape where the radioactivity is measured by a radiation detector. The advantage of this method compared with a direct measurement is that the attenuating effect of the water is removed and thus greater sensitivity is obtained. Compensation for background and any contamination is achieved by feeding distilled water to the aerosol generator every alternate sampling period and recording the count difference between two successive sampling periods . A printed record of the totalised count difference is obtained once per hour during the integration time of one month. For β radioactivity the minimum values of specific activity measurable extend from 1 x 10-6 Ci/m3 to 6 x 10-8 Ci/m depending on the B end-point energy in the range 167 KeV to 2.26 MeV. The estimated minimum measurable specific activity is 6 x 10-8 Ci/m3

  6. Corrosion behavior of technetium waste forms exposed to various aqueous environments

    Energy Technology Data Exchange (ETDEWEB)

    Kolman, David Gary [Los Alamos National Laboratory; Jarvinen, Gordon [Los Alamos National Laboratory; Mausolf, Edward [UNIV OF NEVADA; Czerwinski, Ken [UNIV OF NEVADA; Poineau, Frederic [UNIV OF NEVADA

    2009-01-01

    Technetium is a long-lived beta emitter produced in high yields from uranium as a waste product in spent nuclear fuel and has a high degree of environmental mobility as pertechnetate. It has been proposed that Tc be immobilized into various metallic waste forms to prevent Tc mobility while producing a material that can withstand corrosion exposed to various aqueous medias to prevent the leachability of Tc to the environment over long periods of time. This study investigates the corrosion behavior of Tc and Tc alloyed with 316 stainless steel and Zr exposed to a variety of aqueous media. To date, there is little investigative work related to Tc corrosion behavior and less related to potential Tc containing waste forms. Results indicate that immobilizing Tc into stainless steel-zirconium alloys can be a promising technique to store Tc for long periods of time while reducing the need to separately store used nuclear fuel cladding. Initial results indicate that metallic Tc and its alloys actively corrode in all media. We present preliminary corrosion rates of 100% Tc, 10% Tc - 90% SS{sub 85%}Zr{sub 15%}, and 2% Tc - 98% SS{sub 85%}Zr{sub 15%} in varying concentrations of nitric acid and pH 10 NaOH using the resistance polarization method while observing the trend that higher concentrations of Tc alloyed to the sample tested lowers the corrosion rate of the proposed waste package.

  7. Immobilization of Rose Waste Biomass for Uptake of Pb(II) from Aqueous Solutions

    Science.gov (United States)

    Ansari, Tariq Mahmood; Hanif, Muhammad Asif; Mahmood, Abida; Ijaz, Uzma; Khan, Muhammad Aslam; Nadeem, Raziya; Ali, Muhammad

    2011-01-01

    Rosa centifolia and Rosa gruss an teplitz distillation waste biomass was immobilized using sodium alginate for Pb(II) uptake from aqueous solutions under varied experimental conditions. The maximum Pb(II) adsorption occurred at pH 5. Immobilized rose waste biomasses were modified physically and chemically to enhance Pb(II) removal. The Langmuir sorption isotherm and pseudo-second-order kinetic models fitted well to the adsorption data of Pb(II) by immobilized Rosa centifolia and Rosa gruss an teplitz. The adsorbed metal is recovered by treating immobilized biomass with different chemical reagents (H2SO4, HCl and H3PO4) and maximum Pb(II) recovered when treated with sulphuric acid (95.67%). The presence of cometals Na, Ca(II), Al(III), Cr(III), Cr(VI), and Cu(II), reduced Pb(II) adsorption on Rosa centifolia and Rosa gruss an teplitz waste biomass. It can be concluded from the results of the present study that rose waste can be effectively used for the uptake of Pb(II) from aqueous streams. PMID:21350666

  8. Treatment of Pu-containing waste by acid digestion (wet combustion)

    International Nuclear Information System (INIS)

    Acid digestion as a process of treatment of plutonium-containing solid waste was developed and demonstrated under conditions of an active operation with respect to the recovery of plutonium. The process composes the following main steps: waste shredding, waste carbonisation, waste oxidation and conversion of plutonium oxide to plutonium sulphate, off-gas treatment, acid recovery and plutonium separation. The technical, safety and operational details of the plant will be presented. Furthermore, methods of the purification of separate plutonium and solidification of secondary waste for final disposal will be described. (orig./RW)

  9. Off-gas purification in waste incineration plants: Wet scrubbing solution; Abgasreinigung in Muellverbrennungsanlagen: Nass-Wasch-Loesung

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, T. [ABB Vaaxjoo (Sweden); Eriksson, J. [ABB Vaaxjoo (Sweden); Burdis, V. [ABB Umwelttechnik GmbH, Butzbach (Germany)

    1995-08-01

    The article describes an off-gas purification process for a waste incineration plant. It is a two-stage process. In the first alkaline stage, sulphur dioxide is removed with the aid of sodium hydroxide. In the second stage, calcium hydroxide is added to the solution, and gypsum is produced. The wet scrubber technology was installed and tested in a waste incineration plant in Denmark. (orig.) [Deutsch] Der vorliegende Artikel beschreibt die Abgasreinigung in einer Muellverbrennungsanlage. Mit dem zweistufigen Prozess wird in einem Nasswaescher zunaechst in einer alkalischen Stufe Schwefeldioxid mit Hilfe von Natriumhydroxid entfernt. In einer nachgeschalteten zweiten Stufe wird zu der abgezogenen Loesung des Waeschers Calciumhydroxid gegeben und Gips produziert. Diese Nasswaeschertechnik wurde in einer Muellverbrennungsanlage in Daenemark installiert und erfolgreich getestet. (orig.)

  10. Treatment plan for aqueous/organic/decontamination wastes under the Oak Ridge Reservation FFCA Development, Demonstration, Testing, and Evaluation Program

    Energy Technology Data Exchange (ETDEWEB)

    Backus, P.M.; Benson, C.E.; Gilbert, V.P.

    1994-08-01

    The U.S. Department of Energy (DOE) Oak Ridge Operations Office and the U.S. Environmental Protection Agency (EPA)-Region IV have entered into a Federal Facility Compliance Agreement (FFCA) which seeks to facilitate the treatment of low-level mixed wastes currently stored at the Oak Ridge Reservation (ORR) in violation of the Resource, Conservation and Recovery Act Land Disposal Restrictions. The FFCA establishes schedules for DOE to identify treatment for wastes, referred to as Appendix B wastes, that current have no identified or existing capacity for treatment. A development, demonstration, testing, and evaluation (DDT&E) program was established to provide the support necessary to identify treatment methods for mixed was meeting the Appendix B criteria. The Program has assembled project teams to address treatment development needs for major categories of the Appendix B wastes based on the waste characteristics and possible treatment technologies. The Aqueous, Organic, and Decontamination (A/O/D) project team was established to identify pretreatment options for aqueous and organic wastes which will render the waste acceptable for treatment in existing waste treatment facilities and to identify the processes to decontaminate heterogeneous debris waste. In addition, the project must also address the treatment of secondary waste generated by other DDT&E projects. This report details the activities to be performed under the A/O/D Project in support of the identification, selection, and evaluation of treatment processes. The goals of this plan are (1) to determine the major aqueous and organic waste streams requiring treatment, (2) to determine the treatment steps necessary to make the aqueous and organic waste acceptable for treatment in existing treatment facilities on the ORR or off-site, and (3) to determine the processes necessary to decontaminate heterogeneous wastes that are considered debris.

  11. Treatment plan for aqueous/organic/decontamination wastes under the Oak Ridge Reservation FFCA Development, Demonstration, Testing, and Evaluation Program

    International Nuclear Information System (INIS)

    The U.S. Department of Energy (DOE) Oak Ridge Operations Office and the U.S. Environmental Protection Agency (EPA)-Region IV have entered into a Federal Facility Compliance Agreement (FFCA) which seeks to facilitate the treatment of low-level mixed wastes currently stored at the Oak Ridge Reservation (ORR) in violation of the Resource, Conservation and Recovery Act Land Disposal Restrictions. The FFCA establishes schedules for DOE to identify treatment for wastes, referred to as Appendix B wastes, that current have no identified or existing capacity for treatment. A development, demonstration, testing, and evaluation (DDT ampersand E) program was established to provide the support necessary to identify treatment methods for mixed was meeting the Appendix B criteria. The Program has assembled project teams to address treatment development needs for major categories of the Appendix B wastes based on the waste characteristics and possible treatment technologies. The Aqueous, Organic, and Decontamination (A OE D) project team was established to identify pretreatment options for aqueous and organic wastes which will render the waste acceptable for treatment in existing waste treatment facilities and to identify the processes to decontaminate heterogeneous debris waste. In addition, the project must also address the treatment of secondary waste generated by other DDT ampersand E projects. This report details the activities to be performed under the A OE D Project in support of the identification, selection, and evaluation of treatment processes. The goals of this plan are (1) to determine the major aqueous and organic waste streams requiring treatment, (2) to determine the treatment steps necessary to make the aqueous and organic waste acceptable for treatment in existing treatment facilities on the ORR or off-site, and (3) to determine the processes necessary to decontaminate heterogeneous wastes that are considered debris

  12. Design, fabrication and testing of a wet oxidation waste processing system. [for manned space flight

    Science.gov (United States)

    1975-01-01

    The wet oxidation of sewage sludge during space flight was studied for water and gas recovery, and the elimination of overboard venting. The components of the system are described. Slurry and oxygen supply modules were fabricated and tested. Recommendations for redesign of the equipment are included.

  13. Wet Etching of Amorphous TiO2 Thin Films Using H3PO4-H2O2 Aqueous Solution

    Science.gov (United States)

    Okazaki, Sohei; Ohhashi, Takuya; Nakao, Shoichiro; Hirose, Yasushi; Hitosugi, Taro; Hasegawa, Tetsuya

    2013-09-01

    We report on the wet etching of amorphous undoped and Nb-doped TiO2 thin films using H3PO4-H2O2 etching solution. The etching rate (R) showed a maximum at a H3PO4 concentration of approximately 50 wt % at 80 °C, suggesting that H2PO4- and/or H3O+ is responsible for the etching reaction. The addition of H2O2 to H3PO4 solution significantly enhanced R, and an optimized solution exhibited an R of 13 nm/min at 80 °C, which is one order of magnitude higher than that using H2SO4. These results demonstrate that H3PO4-H2O2 aqueous solution is an effective etchant for TiO2-based amorphous thin films.

  14. Removal of Pb (II from Aqueous Solutions Using Waste Tea Leaves

    Directory of Open Access Journals (Sweden)

    Mehrdad Cheraghi

    2015-03-01

    Full Text Available Background: The presence of lead in natural waters has become an important issue around the world. Lead has been identified as a highly toxic metal that can cause severe environmental and public health problems and its decontamination is of utmost importance. The aim of this work was to evaluate the adsorption of lead (Pb(II on waste tea leaves as a cheap purification method. Methods: In this experimental study, prepared waste tea leaves were used as adsorbent for the removal of Pb (II from aqueous solutions. Adsorption experiments were carried out as batch studies at different contact time, pH, amount of adsorbent, initial metal concentration and temperature. Results: The results showed that maximum removal efficiency was observed at pH 6. Also the adsorption of Pb (II ions increased with decreasing initial metal concentration. The Langmuir isotherm model fits well with the equilibrium adsorption isotherm data and its calculated maximum monolayer adsorption capacity was 166.6 mg g-1 at a temperature of 25±0.1˚C. The kinetic data obtained have been analyzed using pseudo-first-order and pseudo-second-order models. The best fitted kinetic model was found to be pseudo-second-order. Conclusion: The results suggest that tea wastes could be employed as cheap material for the removal of lead from aqueous solutions.

  15. Biosorption of some ions on different bacterial species from aqueous and radioactive waste solutions

    International Nuclear Information System (INIS)

    The uptake of metal ions, cerium, Ce(III); cobalt, Co(II); thorium, Th(IV); and uranium U(VI) by Bacillus pumilus-LRW1, Bacillus cereus-LRW2 and Micrococcus lylae-LRW3 from aqueous solution was examined as a function of metal ion concentration, pH, temperature, and the presence of some foreign ions. The bacterial species exhibited high affinity to accumulate metal ions from their solutions at pH 4-5.0 ± 0.5. The amount of each ion (in mg) accumulated by one gram dry weight of each bacteria was calculated. The uptake by the Bacillus cereus-LRW2 from aqueous solutions and simulated radioactive wastes were also investigated. Electron microscopic investigations showed that the ions were accumulated around the cell wall. (author)

  16. Aqueous nitrate waste treatment: Technology comparison, cost/benefit, and market analysis

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    The purpose of this analysis is to provide information necessary for the Department of Energy (DOE) to evaluate the practical utility of the Nitrate to Ammonia and Ceramic or Glass (NAC/NAG/NAX) process, which is under development in the Oak Ridge National Laboratory. The NAC/NACx/NAX process can convert aqueous radioactive nitrate-laden waste to a glass, ceramic, or grout solid waste form. The tasks include, but are not limited to, the following: Identify current commercial technologies to meet hazardous and radiological waste disposal requirements. The technologies may be thermal or non-thermal but must be all inclusive (i.e., must convert a radionuclide-containing nitrate waste with a pH around 12 to a stable form that can be disposed at permitted facilities); evaluate and compare DOE-sponsored vitrification, grouting, and minimum additive waste stabilization projects for life-cycle costs; compare the technologies above with respect to material costs, capital equipment costs, operating costs, and operating efficiencies. For the NAC/NAG/NAX process, assume aluminum reactant is government furnished and ammonia gas may be marketed; compare the identified technologies with respect to frequency of use within DOE for environmental management applications with appropriate rationale for use; Assess the potential size of the DOE market for the NAC/NAG/NAX process; assess and off-gas issues; and compare with international technologies, including life-cycle estimates.

  17. Aqueous nitrate waste treatment: Technology comparison, cost/benefit, and market analysis

    International Nuclear Information System (INIS)

    The purpose of this analysis is to provide information necessary for the Department of Energy (DOE) to evaluate the practical utility of the Nitrate to Ammonia and Ceramic or Glass (NAC/NAG/NAX) process, which is under development in the Oak Ridge National Laboratory. The NAC/NACx/NAX process can convert aqueous radioactive nitrate-laden waste to a glass, ceramic, or grout solid waste form. The tasks include, but are not limited to, the following: Identify current commercial technologies to meet hazardous and radiological waste disposal requirements. The technologies may be thermal or non-thermal but must be all inclusive (i.e., must convert a radionuclide-containing nitrate waste with a pH around 12 to a stable form that can be disposed at permitted facilities); evaluate and compare DOE-sponsored vitrification, grouting, and minimum additive waste stabilization projects for life-cycle costs; compare the technologies above with respect to material costs, capital equipment costs, operating costs, and operating efficiencies. For the NAC/NAG/NAX process, assume aluminum reactant is government furnished and ammonia gas may be marketed; compare the identified technologies with respect to frequency of use within DOE for environmental management applications with appropriate rationale for use; Assess the potential size of the DOE market for the NAC/NAG/NAX process; assess and off-gas issues; and compare with international technologies, including life-cycle estimates

  18. Removal of cesium from aqueous solutions and radioactive waste stimulants by coprecipitated flotation

    International Nuclear Information System (INIS)

    Coprecipitated flotation (CPF) investigations show that cesium can be efficiently separated from aqueous solutions by coprecipitation with zinc hexacyanoferrate (ZnHCF) and subsequent flotation of the precipitate. Collectors of different types were tested but pyridinium chloride showed the best performance before undertaking the flotation investigations coprecipitation of Cs with ZnHCF was studied to determine the optimal coprecipitation conditions. The developed CPF process was applied successfully for 137Cs removal from process wastewater and low level liquid radioactive waste stimulants . The obtained results compare favorably with data published for cesium removal by coprecipitation or adsorption processes. Besides, CPF seems to be more advantageous

  19. Removal of lead(II) and cadmium(II) from aqueous solutions using grape stalk waste

    OpenAIRE

    Martínez Martínez, María del Rosario; Miralles Esteban, Núria; Hidalgo, S.; Fiol Santaló, Núria; Villaescusa Gil, Isabel; Poch Garcia, Jordi

    2006-01-01

    The sorption of lead and cadmium from aqueous solutions by grape stalk waste (a by-product of wine production) was investigated. The effects of the contact time, pH of the solution, ionic medium, initial metal concentration, other metal ions present and ligands were studied in batch experiments at 20 °C. Maximum sorption for both metals was found to occur at an initial pH of around 5.5. The equilibrium process was described well by the Langmuir isotherm model, with maximum grape stalk sorptio...

  20. Magnetic Adsorption Method for the Treatment of Metal Contaminated Aqueous Waste

    International Nuclear Information System (INIS)

    There have been many recent developments in separation methods used for treating radioactive and non-radioactive metal bearing liquid wastes. These methods have included adsorption, ion exchange, solvent extraction and other chemical and physical techniques. To date very few, if any, of these processes can provide a low cost and environmentally benign solution. Recent research into the use of magnetite for wastewater treatment indicates the potential for magnetite both cost and environment drivers. A brief review of recent work in using magnetite as a sorbent is presented as well as recent work performed in our laboratory using supported magnetite in the presence of an external magnetic field. The application to groundwater and other aqueous waste streams is discussed. Recent research has focused on supporting magnetite in an economical (as compared to the magnetic polymine-epichlorohydrine resin) and inert (non-reactive, chemically or otherwise) environment that promotes both adsorption and satisfactory flow characteristics

  1. Wet and dry cooling systems optimization applied to a modern waste-to-energy cogeneration heat and power plant

    International Nuclear Information System (INIS)

    In Brescia, Italy, heat is delivered to 70% of 200.000 city inhabitants by means of a district heating system, mainly supplied by a waste to energy plant, utilizing the non recyclable fraction of municipal and industrial solid waste (800,000 tons/year, otherwise landfilled), thus saving annually over 150,000 tons of oil equivalent and over 400,000 tons of CO2 emissions. This study shows how the performance of the waste-to-energy cogeneration plant can be improved by optimising the condensation system, with particular focus on the combination of wet and dry cooling systems. The analysis has been carried out using two subsequent steps: in the first one a schematic model of the steam cycle was accomplished in order to acquire a knowledge base about the variables that would be most influential on the performance. In the second step the electric power output for different operating conditions was predicted and optimized in a homemade program. In more details, a thermodynamic analysis of the steam cycle, according to the design operating condition, was performed by means of a commercial code (Thermoflex) dedicated to power plant modelling. Then the off-design behaviour was investigated by varying not only the ambient conditions but also several parameters connected to the heat rejection rate, like the heat required from district heating and the auxiliaries load. Each of these parameters has been addressed and considered in determining the overall performance of the thermal cycle. After that, a complete prediction of the cycle behaviour was performed by simultaneously varying different operating conditions. Finally, a Matlab computer code was developed in order to optimize the net electric power as a function of the way in which the condensation is operated. The result is an optimum set of variables allowing the wet and dry cooling system to be regulated in such a way that the maximum power is achieved. The best strategy consists in using the maximum amount of heat

  2. Biosorption of Methylene Blue from Aqueous Solutions by Diospyrous melanoxylon Leaf Waste

    Directory of Open Access Journals (Sweden)

    Raghvendra G Patil

    2013-04-01

    Full Text Available Waste Tendu (Diospyros melanoxylon leaves from bidi (local cigarette industry has been used as a raw material to produce activated carbon applying sulfuric acid carbonization method. Batch experiments were conducted to assess the potential for the removal of methylene blue dye from aqueous solution using the activated carbon and compared to raw tendu leaves powder and commercial activated carbon. Equilibrium isotherm and kinetic studies have been done by varying the parameters such initial concentration of dye, adsorbent dose, pH of the dye solution, and varying the contact time between the carbon and the dye. It was found that the methylene blue adsorption on tendu waste-based activated carbon conformed to the Langmuir isotherm. The maximum monolayer adsorption capacities were found to be 219.3, 355.9 and 495.1 mg/g for raw tendu waste, carbonized tendu and commercial carbon, respectively. The kinetic studies were well characterized by a pseudo second order kinetic model. The results of this study indicate that raw tendu waste a renewable bioresource, as such as well as its carbonized form are attractive biosorbent for removing a cationic dye from the dye wastewater.DOI: http://dx.doi.org/10.5755/j01.erem.63.1.2735

  3. Removal of Orange 16 reactive dye from aqueous solutions by waste sunflower seed shells

    Directory of Open Access Journals (Sweden)

    TEODOR MALUTAN

    2011-04-01

    Full Text Available In this work, the use of an agro-industrial waste, i.e., sunflower seed shells, was investigated as a sorbent for the removal of Orange 16 reactive dye from aqueous environments. Batch experiments were performed as a function of pH, sorbent dose, dye concentration, temperature and contact time. The per­cent dye removal increased with increasing sorbent dose and temperature of the aqueous solution, and decreased with increasing dye concentration; the re­quired contact time was five hours. The Freundlich, Langmuir, Dubinin–Ra­du­shkevich and Tempkin adsorption isotherms were used to describe the equi­librium sorption data and to determine the corresponding isotherm constants. The thermodynamic parameters, ΔG, ΔH and ΔS, were also determined. These parameters indicated that the sorption of reactive dye onto sunflower seed shells was a spontaneous, endothermic and entropy-driven process. The kinetic data were evaluated by pseudo-first order, pseudo-second order and intra-par­ticle diffusion kinetic models. The results of the kinetic study indicated that the sorption of Orange 16 reactive dye onto sunflower seed shells is a complex process and both chemical surface sorption and intra-particle diffusion contri­bute to the rate-limiting step. Therefore, the sunflower seed shell showed itself to be a promising cheap sorbent for the decolourization of aqueous coloured solutions or effluents.

  4. Engineering development and demonstration of DETOX{sup SM} wet oxidation for mixed waste treatment

    Energy Technology Data Exchange (ETDEWEB)

    Dhooge, P.M.; Goldblatt, S.D.; Moslander, J.E.; Robertson, D.T.; Rogers, T.W.; Zigmond, J.A.

    1997-12-01

    DETOX{sup SM}, a catalyzed chemical oxidation process, is under development for treatment of hazardous and mixed wastes at Department of Energy sites. To support this effort, developmental engineering studies have been formed for aspects of the process to help ensure safe and effective operation. Subscale agitation studies have been preformed to identify a suitable mixing head and speed for the primary reaction vessel agitator. Mechanisms for feeding solid waste materials to the primary reaction vessel have been investigated. Filtration to remove solid field process residue, and the use of various filtration aids, has been studied. Extended compatibility studies on the materials of construction have been performed. Due to a change to Rocky Flats Environmental Technology Site (RFETS) for the mixed waste portion of the demonstration, types of wastes suitable and appropriate for treatment at RFETS had to be chosen. A Prototype unit has been fabricated and will be demonstrated on hazardous and mixed wastes at Savannah River Site (SRS) and RFETS during 1997 and 1998. The unit is in shakedown testing at present. Data validation and an engineering evaluation will be performed during the demonstration.

  5. Engineering development and demonstration of DETOXSM wet oxidation for mixed waste treatment

    International Nuclear Information System (INIS)

    DETOXSM, a catalyzed chemical oxidation process, is under development for treatment of hazardous and mixed wastes at Department of Energy sites. To support this effort, developmental engineering studies have been formed for aspects of the process to help ensure safe and effective operation. Subscale agitation studies have been preformed to identify a suitable mixing head and speed for the primary reaction vessel agitator. Mechanisms for feeding solid waste materials to the primary reaction vessel have been investigated. Filtration to remove solid field process residue, and the use of various filtration aids, has been studied. Extended compatibility studies on the materials of construction have been performed. Due to a change to Rocky Flats Environmental Technology Site (RFETS) for the mixed waste portion of the demonstration, types of wastes suitable and appropriate for treatment at RFETS had to be chosen. A Prototype unit has been fabricated and will be demonstrated on hazardous and mixed wastes at Savannah River Site (SRS) and RFETS during 1997 and 1998. The unit is in shakedown testing at present. Data validation and an engineering evaluation will be performed during the demonstration

  6. Assessment of TEES reg sign applications for Wet Industrial Wastes: Energy benefit and economic analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.C.; Scheer, T.H.

    1992-02-01

    Fundamental work is catalyzed biomass pyrolysis/gasification led to the Thermochemical Environmental Energy System (TEES{reg sign}) concept, a means of converting moist biomass feedstocks to high-value fuel gases such as methane. A low-temperature (350{degrees}C), pressurized (3100 psig) reaction environment and a nickel catalyst are used to reduce volumes of very high-moisture wastes such as food processing byproducts while producing useful quantities of energy. A study was conducted to assess the economic viability of a range of potential applications of the process. Cases examined included feedstocks of cheese whey, grape pomace, spent grain, and an organic chemical waste stream. The analysis indicated that only the organic chemical waste process is economically attractive in the existing energy/economic environment. However, food processing cases will become attractive as alternative disposal practices are curtailed and energy prices rise.

  7. Wet Oxidation Pretreatment of Tobacco Stalks and Orange Waste for Bioethanol Production. Preliminary results

    DEFF Research Database (Denmark)

    Martin, Carlos; Fernandez, Teresa; Garcia, Ariel;

    2009-01-01

    , was inhibited compared to the fermentation of a reference glucose solution. Inhibition was more intense for the filtrate of tobacco stalks than for that of orange waste. The inhibition degree of the volumetric productivity of ethanol was higher (79.1-86.8%) than that of the ethanol yield (7.1-9.5%)....

  8. Industrial symbiosis: high purity recovery of metals from Waelz sintering waste by aqueous SO2 solution.

    Science.gov (United States)

    Copur, Mehmet; Pekdemir, Turgay; Colak, Sabri; Künkül, Asim

    2007-10-22

    Sintering operation in the production of Zn, Cd, and Pb by Waelz process produces a powdery waste containing mainly (about 70%) ZnO, CdO, and PbO. The waste may be referred to as Waelz sintering waste (WSW). The aim of this study is to develop a process for the separation and recovery of the metals from WSW with high purities. The process is based on the dissolution of the WSW in aqueous SO2 solution. The research reported here concentrated on the effect of some important operational parameters on dissolution process. The parameters investigated and their ranges were as follows: SO(2) gas flow rate (V); 38-590 ml/min, stirring speed (W); 100-1000 rpm, reaction temperature (T); 13-60 degrees C, reaction time (t); 1-16 min, and solid-liquid ratio (S/L); 0.1-0.5 g/ml. The results showed that the dissolution rate increased with increasing W, V, and S/L and decreasing T. The best dissolution conditions were found to be V=325 ml/min, W=600 rpm, t=6 min, T=21 degrees C, and S/L=0.1g/ml. Separation of Zn from Cd involved precipitation of ZnSO3 from a mixture solution. The best pH level for the precipitation was observed to be 6. PMID:17482352

  9. Low-temperature catalytic gasification of wet industrial wastes. FY 1993--1994 interim report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.C.; Hart, T.R.; Neuenschwander, G.G.; Deverman, G.S.; Werpy, T.A.; Phelps, M.R.; Baker, E.G.; Sealock, L.J. Jr.

    1995-03-01

    Process development research is continuing on a low-temperature, catalytic gasification system that has been demonstrated to convert organics in water (dilute or concentrated) to useful and environmentally safe gases. The system, licensed under the trade name Thermochemical Environmental Energy System (TEESO), treats a wide variety of feedstocks ranging from hazardous organics in water to waste sludges from food processing. The current research program is focused on the use of continuous-feed, tubular reactors systems for testing catalysts and feedstocks in the process. A range of catalysts have been tested, including nickel and other base metals, as well as ruthenium and other precious metals. Results of extensive testing show that feedstocks, ranging from 2% para-cresol in water to potato waste and spent grain, can be processed to > 99% reduction of chemical oxygen demand (COD). The product fuel gas contains from 40% up to 75% methane, depending on the feedstock. The balance of the gas is mostly carbon dioxide with < 5% hydrogen and usually < 1% ethane and higher hydrocarbons. The byproduct water stream carries residual organics from 10 to 1,000 mg/l COD, depending on the feedstock. The level of development of TEES has progressed to the initial phases of industrial process demonstration. Testing of industrial waste streams is under way at both the bench scale and engineering scale of development.

  10. Extraction-wet oxidation process using sulphuric acid for treatment of TBP-dodecane wastes

    International Nuclear Information System (INIS)

    In the nuclear fuel reprocessing plants, 30% n-tributyl phosphate in hydrocarbon diluent is used for extraction of uranium and plutonium from the spent fuel by Purex process. When TBP-dodecane can no longer be purified from its degradation products, it is discarded as alpha bearing, intermediate level wastes containing plutonium and ruthenium-106. To overcome shortcomings of extraction-pyrolysis and saponification processes, studies were undertaken to find the suitability of H2SO4 as an alternative extractant for TBP. Oxidation of TBP to H3PO4 using H2O2 was also explored as H3PO4 can be treated by known procedures for removal of plutonium and ruthenium-106. The experiments were conducted with aged spent solvent wastes discharged from reprocessing plant at Trombay using H2SO4 and H2SO4 - H3PO4 mixture. The decontamination factors (DFs) for alpha activity were found to be satisfactory. The DFs for ruthenium were lower as compared to those obtained in experiments with simulated degraded waste. The gas chromatographic analysis of separated diluent revealed high branched alkane content and low n-dodecane content of separated diluent. It is very much different from that of diluent currently in use. Hence incineration of separated diluent is recommended. (author)

  11. Removal of arsenate and arsenite from aqueous solution by waste cast iron

    Institute of Scientific and Technical Information of China (English)

    Nag-Choul Choi; Song-Bae Kim; Soon-Oh Kim; Jae-Won Lee; Jun-Boum Park

    2012-01-01

    The removal of As(Ⅲ) and As(Ⅴ) from aqueous solution was investigated using waste cast iron,which is a byproduct of the iron casting process in foundries.Two types of waste cast iron were used in the experiment:grind precipitate dust (GPD) and cast iron shot (CIS).The X-ray diffraction analysis indicated the presence of Fe0 on GPD and CIS.Batch experiments were performed under different concentrations of As(Ⅲ) and As(Ⅴ) and at various initial pH levels.Results showed that waste cast iron was effective in the removal of arsenic.The adsorption isotherm study indicated that the Langmuir isotherm was better than the Freundlich isotherm at describing the experimental result.In the adsorption of both As(Ⅲ) and As(Ⅴ),the adsorption capacity of GPD was greater than CIS,mainly due to the fact that GPD had higher surface area and weight percent of Fe than CIS.Results also indicated the removal of As(Ⅲ) and As(Ⅴ)by GPD and CIS was influenced by the initial solution pH,generally decreasing with increasing pH from 3.0 to 10.5.In addition,both GPD and CIS were more effective at the removal of As(Ⅲ) than As(Ⅴ) under given experimental conditions.This study demonstrates that waste cast iron has potential as a reactive material to treat wastewater and groundwater containing arsenic.

  12. Solidification of aqueous tritium-containing wastes with calcium oxide and asphalt

    International Nuclear Information System (INIS)

    A simple method is proposed for solidifying aqueous tritium-containing wastes with calcium oxide and asphalt. We incorporated tritiated calcium hydroxide into molten asphalt at 100-210/degree/C and studied the evolution of tritium (T) oxides there from as well as the extent to which calcium and tritium are leached out of the solidified product. Depending on temperature and heating time, the evolution of HTO from a Ca(OH)OT-asphalt mixture was low (between 5.6 x 10/sup /minus/4/ and 5.9 x 10/sup /minus/4/ wt.% of the original amount). Tritium evolution rates and leaching coefficients of tritium and calcium showed the solidified product to have high stability in water. Conclusions were drawn as to the usefulness of the proposed method

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

    Directory of Open Access Journals (Sweden)

    Murat Erdem

    2013-01-01

    Full Text Available 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.

  14. In situ electrochemical wet cell transmission electron microscopy characterization of solid–liquid interactions between Ni and aqueous NiCl2

    International Nuclear Information System (INIS)

    Highlights: ► Demonstrated in situ electrochemistry in Ni–NiCl2 (aq) system. ► Observed anisotropic electrodeposition and more isotropic electropolishing. ► Characterized new mechanism based on nucleation ahead of growth front. ► Found consistent results between in situ and ex situ testing. - Abstract: Electrodeposition and electropolishing of nanograined nickel has been observed using an in situ electrochemical wet cell developed for transmission electron microscopy. The cell employs two thin film nickel electrodes in a 0.1 M aqueous NiCl2 electrolyte, which were biased at ±1 V. Anisotropic electrodeposition was observed in which growth of the nickel film across the substrate occurred much more rapidly than growth perpendicular to the substrate. The anisotropic behavior results from relatively equiaxed nanograins nucleating at the growth front with little subsequent coarsening. Grains were observed to nucleate ahead of the growth front, suggesting a new mechanism for electrochemically driven growth across a substrate which depends on ionic surface adsorption ahead of the growth front. During electropolishing the dissolution of nickel tended to occur more isotropically. The film thinned relatively uniformly until certain regions displayed Rayleigh instabilities. At this point the film broke up and some regions coarsened rapidly and/or were subject to electromigration.

  15. Electrochemical decomposition of fluorinated wetting agents in plating industry waste water.

    Science.gov (United States)

    Fath, Andreas; Sacher, Frank; McCaskie, John E

    2016-01-01

    Electrochemical decomposition of fluorinated surfactants (PFAS, perfluorinated alkyl substances) used in the plating industry was analyzed and the decomposition process parameters optimized at the laboratory scale and production scale of a 500-liter reactor using lead electrodes. The method and system was successfully demonstrated under production conditions to treat PFAS) with up to 99% efficiency in the concentration range of 1,000-20,000 μg/l (1 ppm-20 ppm). The treatment also reduced hexavalent chromium (Cr(6+)) ions to trivalent chromium (Cr(3+)) ions in the wastewater. If the PFAS-containing wastewater is mixed with other wastewater streams, specifically from nickel plating drag out solution or when pH values >5, the treatment process is ineffective. For the short chain PFAS, (perfluorobutylsulfonate) the process was less efficient than C6-C8 PFAS. The process is automated and has safety procedures and controls to prevent hazards. The PFAS were decomposed to hydrogen fluoride (HF) under the strong acid electrochemical operating conditions. Analytical tests showed no evidence of organic waste products remaining from the process. Conventional alternative PFAS removal systems were tested on the waste streams and compared with each other and with the-E-destruct (electrochemical oxidation) process. For example, ion exchange resin (IX resin) treatment of wastewater to complex and remove PFAS was found to be seven times more efficient when compared to the conventional activated carbon absorption (C-treat) process. However, the E-destruct process is higher in capacity, exhibits longer service life and lower operating costs than either IX or C-treat methods for elimination of PFAS from these electroplating waste streams. PMID:27054738

  16. A Novel Agricultural Waste Adsorbent, Watermelon Shell for the Removal of Copper from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Koel Banerjee

    2012-01-01

    Full Text Available The present study deals with the application of Watermelon Shell, an agricultural waste, for the adsorptive removal of Cu(II from its aqueous solutions. This paper incorporates the effects of time, dose,temperature, concentration, particle size, agitation speed and pH. Analytical techniques have been employed to find pore properties and characteristics of adsorbent materials. Batch kinetic and isotherm studies have also been performed to understand the ability of the adsorbents. The adsorption behavior of the Cu(II has beenstudied using Freundlich, Langmuir and Tempkin adsorption isotherm models. The monolayer adsorption capacity determined from the Langmuir adsorption equation has been found as 111.1 mg/g. Kineticmeasurements suggest the involvement of pseudo-second-order kinetics in adsorptions and is controlled by a particle diffusion process. Adsorption of Cu(II on adsorbents was found to increase on decreasing initial concentration, increasing pH up to 8, increasing temperature, increasing agitation speed and decreasing particlesize. Overall, the present findings suggest that watermelon outer shell is environmentally friendly, efficient and low-cost biosorbent which is useful for the removal of Cu(II from aqueous media.

  17. Vine-shoot waste aqueous extract applied as foliar fertilizer to grapevines: Effect on amino acids and fermentative volatile content.

    Science.gov (United States)

    Sánchez-Gómez, R; Garde-Cerdán, T; Zalacain, A; Garcia, R; Cabrita, M J; Salinas, M R

    2016-04-15

    The aim of this work was to study the influence of foliar applications of different wood aqueous extracts on the amino acid content of musts and wines from Airén variety; and to study their relationship with the volatile compounds formed during alcoholic fermentation. For this purpose, the foliar treatments proposed were a vine-shoot aqueous extract applied in one and two times, and an oak extract which was only applied once. Results obtained show the potential of Airén vine-shoot waste aqueous extracts to be used as foliar fertilizer, enhancing the wine amino acid content especially when they were applied once. Similar results were observed with the aqueous oak extract. Regarding wine fermentative volatile compounds, there is a close relationship between musts and their wines amino acid content allowing us to discuss about the role of proline during the alcoholic fermentation and the generation of certain volatiles. PMID:26616933

  18. Remediation of alkaline intermediate level radioactive aqueous liquid waste stored along with organic waste at PREFRE Tarapur for ion exchange process: a laboratory scale study

    International Nuclear Information System (INIS)

    Dibutyl phosphate (DBP) and monobutyl phosphate (MBP) are formed during reprocessing of spent fuel as degradation products of Tributyl phosphate (TBP). To maintain the efficiency of TBP solvent during its repeated use, the degraded products are removed by sodium carbonate washing of the solvent. This radioactive sodium carbonate solution is stored in a separate tank along with the exhausted TBP solvent. The presence of degraded products of TBP and their complexes, ion exchange treatment of this waste is creating problems during alpha decontamination step. The present paper deals with the remediation of the aqueous phase of the above waste. For the treatment of the aqueous phase of waste, first the TBP degraded products are required to be removed so that the normal ion exchange treatment can be adopted. (author)

  19. Removal of cadmium from aqueous solutions by adsorption onto orange waste

    International Nuclear Information System (INIS)

    The use of orange wastes, generated in the orange juice industry, for removing cadmium from aqueous solutions has been investigated. The material was characterized by Fourier transform infrared spectroscopy and batch experiments were conducted to determine the adsorption capacity of the biomass. A strong dependence of the adsorption capacity on pH was observed, the capacity increasing as pH value rose. Kinetics and adsorption equilibrium were studied at different pH values (4-6). The adsorption process was quick and the equilibrium was attained within 3 h. The maximum adsorption capacity of orange waste was found to be 0.40, 0.41 and 0.43 mmol/g at pH 4-6, respectively. The kinetic data were analysed using various kinetic models - pseudo-first order equation, pseudo-second order equation, Elovich equation and intraparticle diffusion equation - and the equilibrium data were tested using four isotherm models - Langmuir, Freundlich, Sips and Redlich-Peterson. The data were fitted by non-linear regression and five error analysis methods were used to evaluate the goodness of the fit. The Elovich equation provides the greatest accuracy for the kinetic data and the Sips model the closest fit for the equilibrium data

  20. Removal of cadmium from aqueous solutions by adsorption onto orange waste

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Marin, A.B. [Department of Chemical Engineering, University of Murcia, 30071 Murcia (Spain); Zapata, V. Meseguer [Department of Chemical Engineering, University of Murcia, 30071 Murcia (Spain)]. E-mail: vzapata@um.es; Ortuno, J.F. [Department of Chemical Engineering, University of Murcia, 30071 Murcia (Spain); Aguilar, M. [Department of Chemical Engineering, University of Murcia, 30071 Murcia (Spain); Saez, J. [Department of Chemical Engineering, University of Murcia, 30071 Murcia (Spain); Llorens, M. [Department of Chemical Engineering, University of Murcia, 30071 Murcia (Spain)

    2007-01-02

    The use of orange wastes, generated in the orange juice industry, for removing cadmium from aqueous solutions has been investigated. The material was characterized by Fourier transform infrared spectroscopy and batch experiments were conducted to determine the adsorption capacity of the biomass. A strong dependence of the adsorption capacity on pH was observed, the capacity increasing as pH value rose. Kinetics and adsorption equilibrium were studied at different pH values (4-6). The adsorption process was quick and the equilibrium was attained within 3 h. The maximum adsorption capacity of orange waste was found to be 0.40, 0.41 and 0.43 mmol/g at pH 4-6, respectively. The kinetic data were analysed using various kinetic models - pseudo-first order equation, pseudo-second order equation, Elovich equation and intraparticle diffusion equation - and the equilibrium data were tested using four isotherm models - Langmuir, Freundlich, Sips and Redlich-Peterson. The data were fitted by non-linear regression and five error analysis methods were used to evaluate the goodness of the fit. The Elovich equation provides the greatest accuracy for the kinetic data and the Sips model the closest fit for the equilibrium data.

  1. Purification and characterization of polyphenol oxidase from waste potato peel by aqueous two-phase extraction.

    Science.gov (United States)

    Niphadkar, Sonali S; Vetal, Mangesh D; Rathod, Virendra K

    2015-01-01

    Potato peel from food industrial waste is a good source of polyphenol oxidase (PPO). This work illustrates the application of an aqueous two-phase system (ATPS) for the extraction and purification of PPO from potato peel. ATPS was composed of polyethylene glycol (PEG) and potassium phosphate buffer. Effect of different process parameters, namely, PEG, potassium phosphate buffer, NaCl concentration, and pH of the system, on partition coefficient, purification factor, and yield of PPO enzyme were evaluated. Response surface methodology (RSM) was utilized as a statistical tool for the optimization of ATPS. Optimized experimental conditions were found to be PEG1500 17.62% (w/w), potassium phosphate buffer 15.11% (w/w), and NaCl 2.08 mM at pH 7. At optimized condition, maximum partition coefficient, purification factor, and yield were found to be 3.7, 4.5, and 77.8%, respectively. After partial purification of PPO from ATPS, further purification was done by gel chromatography where its purity was increased up to 12.6-fold. The purified PPO enzyme was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), followed by Km value 3.3 mM, and Vmax value 3333 U/mL, and enzyme stable ranges for temperature and pH of PPO were determined. These results revealed that ATPS would be an attractive option for obtaining purified PPO from waste potato peel. PMID:25036474

  2. Evaluating Transport and Attenuation of Inorganic Contaminants in the Vadose Zone for Aqueous Waste Disposal Sites

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-01

    An approach was developed for evaluating vadose zone transport and attenuation of aqueous wastes containing inorganic (non-volatile) contaminants that were disposed of at the land surface (i.e., directly to the ground in cribs, trenches, tile fields, etc.) and their effect on the underlying groundwater. The approach provides a structured method for estimating transport of contaminants through the vadose zone and the resulting temporal profile of groundwater contaminant concentrations. The intent of the approach is also to provide a means for presenting and explaining the results of the transport analysis in the context of the site-specific waste disposal conditions and site properties, including heterogeneities and other complexities. The document includes considerations related to identifying appropriate monitoring to verify the estimated contaminant transport and associated predictions of groundwater contaminant concentrations. While primarily intended for evaluating contaminant transport under natural attenuation conditions, the approach can also be applied to identify types of, and targets for, mitigation approaches in the vadose zone that would reduce the temporal profile of contaminant concentrations in groundwater, if needed.

  3. Application of biomass for the sorption of radionuclides from low level Purex aqueous wastes

    International Nuclear Information System (INIS)

    Microbial biomass have been found to be good biological adsorbents for radioactive nuclides such as uranium and thorium with comparatively easy desorption and recovery. Based on this, sorption studies have been carried out to assess the feasibility of using biomass Rhizopus arrhizus (RA) for the removal of radionuclides present in Purex low level waste streams. Biomass Rhizopus arrhizus (RA) appears effective for the removal of actinides and fission products from low level Purex plant waste/effluent solutions. Maximum sorption for uranium and plutonium is observed at 6-7 pH whereas for Am, Eu, Pm, Ce and Zr the sorption is maximum at pH 2 with high D values and fast kinetics in both cases. Sorption for Ru and Cs are negligible. Sorbed nuclides are recoverable by elution with 1 M HNO3, on once through basis. The method can be used for treating the evaporator condensates from the plant and the hold-up delay tank solution. The sodium nitrate salt concentration in the aqueous solution beyond 0.14 M seriously affects the metal uptake. The results from column experiments indicate a limited loading capacity in terms of mg of Am/U/Pu etc. per gm of RA. However, as the Purex low level effluents contain only trace level activities whose absolute ionic concentrations are much lower, the capacities observed with the present form of biomass may still be satisfactory

  4. Evaluation of Wet Chemical ICP-AES Elemental Analysis Methods using Simulated Hanford Waste Samples-Phase I Interim Report

    International Nuclear Information System (INIS)

    The wet chemistry digestion method development for providing process control elemental analyses of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Melter Feed Preparation Vessel (MFPV) samples is divided into two phases: Phase I consists of: (1) optimizing digestion methods as a precursor to elemental analyses by ICP-AES techniques; (2) selecting methods with the desired analytical reliability and speed to support the nine-hour or less turnaround time requirement of the WTP; and (3) providing baseline comparison to the laser ablation (LA) sample introduction technique for ICP-AES elemental analyses that is being developed at the Savannah River National Laboratory (SRNL). Phase II consists of: (1) Time-and-Motion study of the selected methods from Phase I with actual Hanford waste or waste simulants in shielded cell facilities to ensure that the methods can be performed remotely and maintain the desired characteristics; and (2) digestion of glass samples prepared from actual Hanford Waste tank sludge for providing comparative results to the LA Phase II study. Based on the Phase I testing discussed in this report, a tandem digestion approach consisting of sodium peroxide fusion digestions carried out in nickel crucibles and warm mixed-acid digestions carried out in plastic bottles has been selected for Time-and-Motion study in Phase II. SRNL experience with performing this analytical approach in laboratory hoods indicates that well-trained cell operator teams will be able to perform the tandem digestions in five hours or less. The selected approach will produce two sets of solutions for analysis by ICP-AES techniques. Four hours would then be allocated for performing the ICP-AES analyses and reporting results to meet the nine-hour or less turnaround time requirement. The tandem digestion approach will need to be performed in two separate shielded analytical cells by two separate cell operator teams in order to achieve the nine-hour or less turnaround

  5. Considerations affecting deep-well disposal of tritium-bearing low-level aqueous waste from nuclear fuel reprocessing plants

    Energy Technology Data Exchange (ETDEWEB)

    Trevorrow, L. E.; Warner, D. L.; Steindler, M. J.

    1977-03-01

    Present concepts of disposal of low-level aqueous wastes (LLAW) that contain much of the fission-product tritium from light water reactors involve dispersal to the atmosphere or to surface streams at fuel reprocessing plants. These concepts have been challenged in recent years. Deep-well injection of low-level aqueous wastes, an alternative to biospheric dispersal, is the subject of this presentation. Many factors must be considered in assessing its feasibility, including technology, costs, environmental impact, legal and regulatory constraints, and siting. Examination of these factors indicates that the technology of deep-well injection, extensively developed for other industrial wastes, would require little innovation before application to low-level aqueous wastes. Costs would be low, of the order of magnitude of 10/sup -4/ mill/kWh. The environmental impact of normal deep-well disposal would be small, compared with dispersal to the atmosphere or to surface streams; abnormal operation would not be expected to produce catastrophic results. Geologically suitable sites are abundant in the U.S., but a well would best be co-located with the fuel-reprocessing plant where the LLAW is produced. Legal and regulatory constraints now being developed will be the most important determinants of the feasibility of applying the method.

  6. Considerations affecting deep-well disposal of tritium-bearing low-level aqueous waste from nuclear fuel reprocessing plants

    International Nuclear Information System (INIS)

    Present concepts of disposal of low-level aqueous wastes (LLAW) that contain much of the fission-product tritium from light water reactors involve dispersal to the atmosphere or to surface streams at fuel reprocessing plants. These concepts have been challenged in recent years. Deep-well injection of low-level aqueous wastes, an alternative to biospheric dispersal, is the subject of this presentation. Many factors must be considered in assessing its feasibility, including technology, costs, environmental impact, legal and regulatory constraints, and siting. Examination of these factors indicates that the technology of deep-well injection, extensively developed for other industrial wastes, would require little innovation before application to low-level aqueous wastes. Costs would be low, of the order of magnitude of 10-4 mill/kWh. The environmental impact of normal deep-well disposal would be small, compared with dispersal to the atmosphere or to surface streams; abnormal operation would not be expected to produce catastrophic results. Geologically suitable sites are abundant in the U.S., but a well would best be co-located with the fuel-reprocessing plant where the LLAW is produced. Legal and regulatory constraints now being developed will be the most important determinants of the feasibility of applying the method

  7. Method for solidification of aqueous, radioactive wastes in a glass, glass ceramic or glass ceramic-like matrix

    International Nuclear Information System (INIS)

    The invention deals with an improvement of the known method to solidify aqueous, highly radioactive waste in a glass matrix or in a glass ceramic matrix in which the previously denitrated waste water is spray-dried and calined. The calined product occuring can then be mixed with glass-forming substances or with ground glass grit and then be melted in a crucible or oven to a homogeneous mass. By applying such a method however, the spray nozzle in the spray calcinator gets blocked up after a time. In order to avoid this the invention suggests to add kieselguhr-like material in solid form to the aqueous waste solution prior to spray drying. The kieselguhr has a composition of about 90 wt.% SiO2; 4 wt.% Al2O3; 3.3 wt.% Na2O+K2O; 1.3 wt.% Fe2O3, as well as MgO, CO, TiO2 and P2O5 with grain sizes of more than 70 wt.% grain size distribution between 10 and 40 mum. The kieselguhr is added to the aqueous waste solution in a quantity of 50 to 60 g/l. (orig./PW)

  8. Assessment for development of an industrial wet oxidation system for burning waste and low-grade fuels. Final report, October 18, 1989--February 28, 1995

    International Nuclear Information System (INIS)

    The ultimate goal of this program was to demonstrate safe, reliable, and effective operation of the supercritical water oxidation process (SCWO) at a pilot plant-level throughput. This program was a three phase program. Phase 1 of the program preceded MODEC's participation in the program. MODEC did participate in Phases 2 and 3 of the program. In Phase 2, the target waste and industry were pulp mill sludges from the pulp and paper industry. In Phase 3, the target was modified to be DOE-generated mixed low level waste; wastes containing RCRA hazardous constituents and radionuclide surrogates were used as model wastes. The paper describes the research unit planning and design; bench-scale development of SCWO; research and development of wet oxidation of fuels; and the design of a super-critical water pilot plant

  9. Wet oxidation processes for water pollution remediation

    OpenAIRE

    García Molina, Verónica

    2006-01-01

    [eng] The main objective of this work was to test the efficiency of wet oxidation processes when treating several types of aqueous wastes. On one side its performance for the abatement of chloro-organic aromatic toxic pollutants, such as 4-chlorophenol and 2,4-dichlorophenol has been studied. On the other hand, wastewater from pulp and paper mills, which has been reported to be an indirect source of entry of chlorophenols in the aquatic environment, has been investigated. More in detail, it h...

  10. Low-cost adsorbents from bio-waste for the removal of dyes from aqueous solution.

    Science.gov (United States)

    Manoj Kumar Reddy, P; Mahammadunnisa, Sk; Ramaraju, B; Sreedhar, B; Subrahmanyam, Ch

    2013-06-01

    Activated carbons (ACs) were developed from bio-waste materials like rice husk and peanut shell (PS) by various physicochemical activation methods. PS char digested in nitric acid followed by treatment at 673 K resulted in high surface area up to ∼585 m(2)/g. The novelty of the present study is the identification of oxygen functional groups formed on the surface of activated carbons by infrared and X-ray photoelectron spectroscopy and quantification by using temperature programmed decomposition (TPD). Typical TPD data indicated that each activation method may lead to varying amounts of acidic and basic functional groups on the surface of the adsorbent, which may be a crucial factor in determining the adsorption capacity. It was shown that ACs developed during the present study are good adsorbents, especially for the removal of a model textile dye methylene blue (MB) from aqueous solution. As MB is a basic dye, H(2)O(2)-treated rice husk showed the best adsorption capacity, which is in agreement with the acidic groups present on the surface. Removal of the dye followed Langmuir isotherm model, whereas MB adsorption on ACs followed pseudo-second-order kinetics. PMID:23233187

  11. Chemically modified biochar produced from conocarpus waste increases NO3 removal from aqueous solutions.

    Science.gov (United States)

    Usman, Adel R A; Ahmad, Mahtab; El-Mahrouky, Mohamed; Al-Omran, Abdulrasoul; Ok, Yong Sik; Sallam, Abdelazeem Sh; El-Naggar, Ahmed H; Al-Wabel, Mohammad I

    2016-04-01

    Biochar has emerged as a universal sorbent for the removal of contaminants from water and soil. However, its efficiency is lower than that of commercially available sorbents. Engineering biochar by chemical modification may improve its sorption efficiency. In this study, conocarpus green waste was chemically modified with magnesium and iron oxides and then subjected to thermal pyrolysis to produce biochar. These chemically modified biochars were tested for NO3 removal efficiency from aqueous solutions in batch sorption isothermal and kinetic experiments. The results revealed that MgO-biochar outperformed other biochars with a maximum NO3 sorption capacity of 45.36 mmol kg(-1) predicted by the Langmuir sorption model. The kinetics data were well described by the Type 1 pseudo-second-order model, indicating chemisorption as the dominating mechanism of NO3 sorption onto biochars. Greater efficiency of MgO-biochar was related to its high specific surface area (391.8 m(2) g(-1)) and formation of strong ionic complexes with NO3. At an initial pH of 2, more than 89 % NO3 removal efficiency was observed for all of the biochars. We conclude that chemical modification can alter the surface chemistry of biochar, thereby leading to enhanced sorption capacity compared with simple biochar. PMID:26100325

  12. Removal of hexavalent chromium from aqueous solution by agricultural waste biomass

    International Nuclear Information System (INIS)

    In the present study adsorption of Cr(VI) from aqueous solutions onto different agricultural wastes, viz., sugarcane bagasse, maize corn cob and Jatropha oil cake under various experimental conditions has been studied. Effects of adsorbent dosage, Cr(VI) concentration, pH and contact time on the adsorption of hexavalent chromium were investigated. The concentration of chromium in the test solution was determined spectrophotometrically. FT-IR spectra of the adsorbents (before use and after exhaustion) were recorded to explore number and position of the functional groups available for the binding of chromium ions on to studied adsorbents. SEMs of the adsorbents were recorded to explore the morphology of the studied adsorbents. Maximum adsorption was observed in the acidic medium at pH 2 with a contact time of 60 min at 250 rpm stirring speed. Jatropha oil cake had better adsorption capacity than sugarcane bagasse and maize corn cob under identical experimental conditions. The applicability of the Langmuir and Freundlich adsorption isotherms was tested. The results showed that studied adsorbents can be an attractive low cost alternative for the treatment of wastewaters in batched or stirred mode reactors containing lower concentrations of chromium

  13. Removal of acid blue 062 on aqueous solution using calcinated colemanite ore waste

    International Nuclear Information System (INIS)

    Colemanite ore waste (CW) has been employed as adsorbent for the removal of acid blue 062 anionic dye (AB 062) from aqueous solution. The adsorption of AB 062 onto CW was examined with respect to contact time, calcination temperature, particle size, pH, adsorbent dosage and temperature. The physical and chemical properties of the CW, such as particle sizes and calcinations temperature, play important roles in dye adsorption. The dye adsorption largely depends on the initial pH of the solution with maximum uptake occurring at pH 1.Three simplified kinetics models, namely, pseudo-first order, pseudo-second order, and intraparticle diffusion models were tested to investigate the adsorption mechanisms. The kinetic adsorption of AB 062 on CW follows a pseudo-second order equation. The adsorption data have been analyzed using Langmuir and Freundlich isotherms. The results indicate that the Langmuir model provides the best correlation of the experimental data. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of the adsorption of dye onto CW

  14. Sugarcane bagasse for the removal of erythrosin B and methylene blue from aqueous waste

    Science.gov (United States)

    Sharma, Pankaj; Kaur, Harleen

    2011-12-01

    Present study explores the potentiality of locally available cellulose, hemicellulose and lignin-rich agricultural by-product sugarcane bagasse (SB) for the removal of erythrosin B (EB) and methylene blue (MB) from aqueous waste. The SB has been characterized by Fourier transform infrared and scanning electron microscopy analytical techniques. Batch experiments have been carried out to determine the influence of parameters like initial dye concentration, pH of the medium, contact time between the adsorbate and adsorbent, weight of adsorbent and system temperature on the removal of EB and MB. Optimum conditions for adsorption are found to be pH 9, temperature 308 K and an equilibration time of 1 h. Under these conditions equilibrium isotherms have been analysed by Langmuir and Freundlich isotherm equations. Based on the Langmuir adsorption isotherm model, the predicted maximum monolayer adsorption capacities of SB for EB and MB are found to be 500 mg g-1 (at 328 K) and 1,000 mg g-1 (at 308 K), respectively. The separation factor reveals the favourable nature of the isotherm for the studied dyes—SB system. The thermodynamic study indicates that the adsorptions of dyes are spontaneous and endothermic process. High temperatures favour EB adsorption whereas optimum temperature for MB adsorption is 318 K.

  15. Bioadsorption of a reactive dye from aqueous solution by municipal solid waste

    Directory of Open Access Journals (Sweden)

    Abdelkader Berrazoum

    2015-09-01

    Full Text Available The biosorbent was obtained from municipal solid waste (MSW of the Mostaganem city. Before use the MSW was dried in air for three days and washed several times. The sorption of yellow procion reactive dye MX-3R onto biomass from aqueous solution was investigated as function of pH, contact time and temperature. The adsorption capacity of MX-3R was 45.84 mg/g at pH 2–3 and room temperature. MX-3R adsorption decreases with increasing temperature. The Langmuir, Freundlich and Langmuir–Freundlich adsorption models were applied to describe the related isotherms. Langmuir–Freundlich equation has shown the best fitting with the experimental data. The pseudo first-order, pseudo second-order and intra-particle diffusion kinetic models were used to describe the kinetic sorption. The results clearly showed that the adsorption of MX-3R onto biosorbent followed the pseudo second-order model. The enthalpy (ΔH°, entropy (ΔS° and Gibbs free energy (ΔG° changes of adsorption were calculated. The results indicated that the adsorption of MX-3R occurs spontaneously as an exothermic process.

  16. Adsorption of Hexavalent Chromium from Aqueous Solution Using Chemically Activated Carbon Prepared from Locally Available Waste of Bamboo (Oxytenanthera abyssinica)

    OpenAIRE

    Dula, Tamirat; Siraj, Khalid; Kitte, Shimeles Addisu

    2014-01-01

    This study reports on the adsorption of Hexavalent Chromium from aqueous solutions using activated carbon prepared from bamboo (Oxytenanthera abyssinica) waste by KOH activation heating in an electrical furnace at 1073 K for 3 hrs. Batch adsorption experiments were also carried out as a function of pH, contact time, initial concentration of the adsorbate, adsorbent dosage, and temperature of the solution. Kinetic studies of the data showed that the adsorption follows the pseudo-second-order k...

  17. Recovery and characterization of Balanites aegyptiaca Del. kernel proteins. Effect of defatting, air classification, wet sieving and aqueous ethanol treatment on solubility, digestibility, amino acid composition and sapogenin content.

    Science.gov (United States)

    Mohamed, A M; Wolf, W; Spiess, W E

    2000-02-01

    In order to find alternative protein sources in African regions where protein deficiency in nutrition is prevailing, solubility, in-vitro digestibility, amino acid composition and chemical score of Balanites aegyptiaca Del. kernel proteins were investigated as a function of different processing steps including defatting, air classification, wet sieving and aqueous ethanol treatment. Air classification delivered a fine fraction of 58.1% of the total protein. Applying a wet sieving process, a protein concentrate of 72.9% protein content was achieved but the recovery was very low (35.6%). However, in case of isoelectric precipitation followed by aqueous ethanol treatment both protein content (78.2%) and recovery (53.7%) were high. Data concerning the chemical score revealed, that lysine content of the defatted kernel flour amounted to 74.2% of the recommended FAO/WHO standard level. In-vitro protein digestibility was found to be higher than of legume proteins. The digestible protein of the full fat flour, defatted flour, air classified and wet sieved fine fractions and protein concentrate were 91.9, 93.7, 82.0, 86.4 and 94.2%, respectively. The sapogenin content per 100 g protein of the investigated protein preparations was significantly lower (46% to 62%) than of the initial material (oilcake). PMID:10702992

  18. Utilization of fermentation waste (Corynebacterium glutamicum) for biosorption of Reactive Black 5 from aqueous solution

    International Nuclear Information System (INIS)

    A fermentation waste, Corynebacterium glutamicum, was successfully employed as a biosorbent for Reactive Black 5 (RB5) from aqueous solution. This paper initially studied the effect of pretreatment on the biosorption capacity of C. glutamicum toward RB5, using several chemical agents, such as HCl, H2SO4, HNO3, NaOH, Na2CO3, CaCl2 and NaCl. Among these reagents, 0.1 M HNO3 gave the maximum enhancement of the RB5 uptake, exhibiting 195 mg/g at pH 1 with an initial RB5 concentration of 500 mg/l. The solution pH and temperature were found to affect the biosorption capacity, and the biosorption isotherms derived at different pHs and temperatures revealed that a low pH (pH 1) and high temperature (35 deg. C) favored biosorption. The biosorption isotherm was well represented using three-parameter models (Redlich-Peterson and Sips) compared to two-parameter models (Langmuir and Freundlich models). As a result, high correlation coefficients and low average percentage error values were observed for three-parameter models. A maximum RB5 uptake of 419 mg/g was obtained at pH 1 and a temperature of 35 deg. C, according to the Langmuir model. The kinetics of the biosorption process with different initial concentrations (500-2000 mg/l) was also monitored, and the data were analyzed using pseudo-first and pseudo-second order models, with the latter describing the data well. Various thermodynamic parameters, such as ΔGo, ΔHo and ΔSo, were calculated, indicating that the present system was a spontaneous and endothermic process. The use of a 0.1 M NaOH solution successfully desorbed almost all the dye molecules from dye-loaded C. glutamicum biomass at different solid-to-liquid ratios examined

  19. Experimental reduction of aqueous sulphate by hydrogen under hydrothermal conditions: Implication for the nuclear waste storage

    Science.gov (United States)

    Truche, Laurent; Berger, Gilles; Destrigneville, Christine; Pages, Alain; Guillaume, Damien; Giffaut, Eric; Jacquot, Emmanuel

    2009-08-01

    Sulphate reduction by hydrogen, likely to occur in deep geological nuclear waste storage sites, was studied experimentally in a two-phase system (water + gas) at 250-300 °C and under 4-16 bars H 2 partial pressure in hydrothermal-vessels. The calculated activation energy is 131 kJ/mol and the half-life of aqueous sulphate in the presence of hydrogen and elemental sulphur ranges from 210,000 to 2.7 × 10 9 years at respective temperatures of 90 °C, the thermal peak in the site and 25 °C, the ambient temperature far from the site. The features and rate of the sulphate reduction by H 2 are close to those established for TSR in oil fields. The experiments also show that the rate of sulphate reduction is not significantly affected in the H 2 pressure range of 4-16 bars and in the pH range of 2-5, whereas a strong increase is measured at pH below 2. We suggest that the condition for the reaction to occur is the speciation of sulphate dominated by non symmetric species ( HSO4- at low pH), and we propose a three steps reaction, one for each intermediate-valence sulphur species, the first one requiring H 2S as electron donor rather than H 2. We distinguish two possible reaction pathways for the first step, depending on pH: reduction of sulphate into sulphur dioxide below pH 2 or into thiosulphate or sulphite + elemental sulphur in the pH range 2-5.

  20. Heterogeneous catalysis contribution for the denitration of aqueous nuclear radioactive waste with formic acid

    International Nuclear Information System (INIS)

    The chemical denitration aims to reduce the nitric acid concentration in nuclear fuel reprocessing aqueous wastes by adding formic acid as a reducing agent. The denitration reaction exhibits an induction period, which duration is related to the time needed by the key intermediate of the reaction, i.e. nitrous acid, to reach a threshold concentration in the reaction medium. The addition of a Pt/SiO2 catalyst in the reaction mixture suppresses the induction period of the chemical denitration. The aim of the present work is to identify the role of Pt/SiO2 in the catalytic denitration mechanism. The experimental work is based on the comparison of catalytic tests performed with various catalysts, in order to identify the intrinsic characteristics of Pt/SiO2 that might influence its activity for the reaction. Catalytic denitration results show that Pt/SiO2 acts only by speeding up the nitrous acid generation in the solution until its concentration reaches the threshold level of 0,01 mol L-1 in the experimental conditions. Catalysts activity is evaluated by quantifying the nitrous acid generated on the platinum surface during the induction period of the homogeneous denitration reaction. The large platinum aggregates reactivity is greater than the one of nano-sized particles. The study of the key step of the catalytic denitration reaction, the catalytic generation of nitrous acid, clarifies the role of Pt/SiO2. The homogeneous denitration is initiated thanks to a redox cycle on the catalyst surface: an initial oxidation of Pt0 by nitric acid, which is reduced into nitrous acid, followed by the reduction of the passivated 'Ptox' by formic acid. Furthermore, a platinum reduction by formic acid prior to the catalytic test prevents any platinum leaching from the catalyst into the nitric solution, being all the more significant as platinum dispersion is high. (author)

  1. The influence of non-aqueous radiochemical processes on radiation parameters of spent fuel and radioactive wastes

    International Nuclear Information System (INIS)

    The influence of the technology applied for separation of radioactive elements on radiation parameters of fuel and wastes when using non-aqueous radiochemical processing of spent fuels are studied. The results of calculational modelling the fuel recycle in the BREST-1200 reactor closed fuel cycle are considered. The data characterizing contribution of separate elements in potential biological danger (dose) and the dependence of the potential biological danger of the wastes on regenerated fuel cooling time are discussed. It is shown that plutonium and americium give the main contributions into the fuel potential biological danger in time period of 40-1000 years. For monitored cooling of 120-150 years the balance between natural uranium potential biological danger and that of wastes at different waste compositions is achievable. The fission product contributions into potential biological danger differ slightly for different variants of the processing technology. The 99Tc contribution is noticeable only in the case of metallurgical processing. The conclusion is made that differences in radiochemical technologies applied for waste fracturing and fuel purification degree do not influence in principle on capabilities for radiation balance achieving. For a long-time perspective the radiation balance is determined by plutonium, americium and their decay products. The technology peculiarities may change radiation characteristics of wastes only at separate stages of cooling and do not affect greatly the radiation balance as a whole

  2. Separation of transuranium elements and fission products from medium activity aqueous liquid wastes

    International Nuclear Information System (INIS)

    In the course of work performed between January 1981 and June 1985 on the separation of TRU elements and fission products three liquid alpha containing waste streams were treated: - medium level waste solutions, - waste solutions from the acid digestion of burnable alpha containing solid residues, - waste solutions from mixed oxide fuel element fabrication. The method of separation was initially developed and optimized with simulating substances. Subesequently it was tested with real waste solutions

  3. Effective removal of tetracycline from aqueous solution using activated carbon prepared from tomato (Lycopersicon esculentum Mill.) industrial processing waste.

    Science.gov (United States)

    Sayğılı, Hasan; Güzel, Fuat

    2016-09-01

    Activated carbon (TAC) prepared under optimized conditions with ZnCl2 activation from a new precursor; tomato industrial processing waste (TW), was applied as an adsorbent to remove tetracycline (TC) from aqueous solution. The factors (TAC dosage, initial TC concentration, contact time, ionic strength and solution temperature) affecting the adsorption process were examined at natural pH (5.7) of TAC-TC system in aqueous solution. Kinetic data was found to be best complied by the pseudo-second order model. The isotherm analysis indicated that the equilibrium data could be represented by the Langmuir model. The maximum adsorption capacity was identified as 500.0mgg(-1) at 308K. PMID:27177317

  4. Utilization of fermentation waste (Corynebacterium glutamicum) for biosorption of Reactive Black 5 from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Vijayaraghavan, K. [Division of Environmental and Chemical Engineering, Research Institute of Industrial Technology, Chonbuk National University, Chonju 561-756 (Korea, Republic of)]. E-mail: drkvijy@chonbuk.ac.kr; Yun, Yeoung-Sang [Division of Environmental and Chemical Engineering, Research Institute of Industrial Technology, Chonbuk National University, Chonju 561-756 (Korea, Republic of)]. E-mail: ysyun@chonbuk.ac.kr

    2007-03-06

    A fermentation waste, Corynebacterium glutamicum, was successfully employed as a biosorbent for Reactive Black 5 (RB5) from aqueous solution. This paper initially studied the effect of pretreatment on the biosorption capacity of C. glutamicum toward RB5, using several chemical agents, such as HCl, H{sub 2}SO{sub 4}, HNO{sub 3}, NaOH, Na{sub 2}CO{sub 3}, CaCl{sub 2} and NaCl. Among these reagents, 0.1 M HNO{sub 3} gave the maximum enhancement of the RB5 uptake, exhibiting 195 mg/g at pH 1 with an initial RB5 concentration of 500 mg/l. The solution pH and temperature were found to affect the biosorption capacity, and the biosorption isotherms derived at different pHs and temperatures revealed that a low pH (pH 1) and high temperature (35 deg. C) favored biosorption. The biosorption isotherm was well represented using three-parameter models (Redlich-Peterson and Sips) compared to two-parameter models (Langmuir and Freundlich models). As a result, high correlation coefficients and low average percentage error values were observed for three-parameter models. A maximum RB5 uptake of 419 mg/g was obtained at pH 1 and a temperature of 35 deg. C, according to the Langmuir model. The kinetics of the biosorption process with different initial concentrations (500-2000 mg/l) was also monitored, and the data were analyzed using pseudo-first and pseudo-second order models, with the latter describing the data well. Various thermodynamic parameters, such as {delta}G{sup o}, {delta}H{sup o} and {delta}S{sup o}, were calculated, indicating that the present system was a spontaneous and endothermic process. The use of a 0.1 M NaOH solution successfully desorbed almost all the dye molecules from dye-loaded C. glutamicum biomass at different solid-to-liquid ratios examined.

  5. Aqueous corrosion of silicate glasses. Analogy between volcanic glasses and the French nuclear waste glass R7T7

    International Nuclear Information System (INIS)

    The behaviour of borosilicate glasses upon aqueous corrosion is controlled for long periods of time (>10,000 years) by processes which are not directly accessible by means of laboratory experiments. The analogical approach consists here to compare leaching performances between the french nuclear waste glass R7T7 and natural volcanic glasses, basaltic and rhyolitic ones. The three glasses were leached in the same conditions; open system, 90 deg C, initial pH of 9.7. Basaltic and R7T7 glasses having the same kinetic of dissolution, the basaltic glass was chosen as the best analogue. (author). refs., figs., tabs

  6. Kinetic and Equilibrium Studies of Cesium-137 Adsorption on Olive Waste from Aqueous Solutions Kinetic and Equilibrium Studies of Cesium-137 Adsorption on Olive Waste from Aqueous Solutions

    International Nuclear Information System (INIS)

    The agricultural by-product olive pomace either in its raw material or carbonized form was used for the removal of 137Cs from aqueous solutions. Experimental studies were conducted to evaluate and optimize some affecting factor such as contact time, adsorbent dosage, ph value and initial 137Cs concentration ions. The sorption process was described by pseudo first-order, pseudo second-order and Intra-particle diffusion models. Data have been interpreted in terms of Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms. The obtained data showed that 120 minutes are sufficient time to attain equilibrium and maximum % removal of 137Cs was found 80% and 99% for raw olive pomace and its carbonized form, respectively. The maximum sorption capacity of raw and carbonized adsorbent for cesium removal was 0.360 and 0.565 mol/g respectively.

  7. Recovery, purification and concentration of plutonium and americium from the aqueous wastes discharged in the reprocessing process studies

    International Nuclear Information System (INIS)

    For recovering and purifying plutonium and americium from the aqueous wastes occurring in the process studies on reprocessing, a standard procedure has been established for use in the laboratory works, through the preliminary tests of the precipitation as hydroxides and the anion exchange in nitrate media. The procedure was proven in the treatment of actual wastes, of which the results were contributed to determine the process conditions in the plutonium purification and product concentration of the JAERI Reprocessing Test Plant. The preliminary tests also include washing of U and Am recovery from the anion-exchanger in nitrate media, direct ion-exchange recovery of Pu from the TBP phase and elution of Am from the cation-exchanger. (auth.)

  8. Actinide recovery using aqueous biphasic extraction: Initial developmental studies

    International Nuclear Information System (INIS)

    Aqueous biphasic extraction systems are being developed to treat radioactive wastes. The separation technique involves the selective partitioning of either solutes or colloid-size particles between two scible aqueous phases. Wet grinding of plutonium residues to an average particle size of one micron will be used to liberate the plutonium from the bulk of the particle matrix. The goal is to produce a plutonium concentrate that will integrate with existing and developing chemical recovery processes. Ideally, the process would produce a nonTRU waste stream. Coupling physical beneficiation with chemical processing will result in a substantial reduction in the volume of mixed wastes generated from dissolution recovery processes. As part of this program, we will also explore applications of aqueous biphasic extraction that include the separation and recovery of dissolved species such as metal ions and water-soluble organics. The expertise and data generated in this work will form the basis for developing more cost-effective processes for handling waste streams from environmental restoration and waste management activities within the DOE community. This report summarizes the experimental results obtained during the first year of this effort. Experimental efforts were focused on elucidating the surface and solution chemistry variables which govern partitioning behavior of plutonium and silica in aqueous biphasic extraction systems. Additional efforts were directed toward the development of wet grinding methods for producing ultrafine particles with diameters of one micron or less

  9. Actinide recovery using aqueous biphasic extraction: Initial developmental studies

    Energy Technology Data Exchange (ETDEWEB)

    Chaiko, D.J.; Mensah-Biney, R.; Mertz, C.J.; Rollins, A.N.

    1992-08-01

    Aqueous biphasic extraction systems are being developed to treat radioactive wastes. The separation technique involves the selective partitioning of either solutes or colloid-size particles between two scible aqueous phases. Wet grinding of plutonium residues to an average particle size of one micron will be used to liberate the plutonium from the bulk of the particle matrix. The goal is to produce a plutonium concentrate that will integrate with existing and developing chemical recovery processes. Ideally, the process would produce a nonTRU waste stream. Coupling physical beneficiation with chemical processing will result in a substantial reduction in the volume of mixed wastes generated from dissolution recovery processes. As part of this program, we will also explore applications of aqueous biphasic extraction that include the separation and recovery of dissolved species such as metal ions and water-soluble organics. The expertise and data generated in this work will form the basis for developing more cost-effective processes for handling waste streams from environmental restoration and waste management activities within the DOE community. This report summarizes the experimental results obtained during the first year of this effort. Experimental efforts were focused on elucidating the surface and solution chemistry variables which govern partitioning behavior of plutonium and silica in aqueous biphasic extraction systems. Additional efforts were directed toward the development of wet grinding methods for producing ultrafine particles with diameters of one micron or less.

  10. Ion-Exchange characteristic of carboxymethylated cross-linked pregelled starch removal of co-60 and Cs-137 from aqueous waste solution

    International Nuclear Information System (INIS)

    Low and intermediate radioactive liquid waste streams are resulting mainly from Nuclear Power Plants in addition to that originating from the applications of radioisotopes in different fields of life (medicine-industry-agriculture, research works, ect...). Treatment of these aqueous waste solutions before its release is an important process that keeps the environment clean for man and for the coming generations. Carboxymethylated cross-linked pregelled starch has been prepared and used as an organic exchanger for the removal of Co-60 and Cs-137 from aqueous waste simulate. More than 90% of Co-60 and up to 60% of Cs-137 were removed from the waste streams at 29±1 degree after 60 minutes. Different factors that may affect the removal process of both radionuclides using the exchanger (e.g. contact time, temperature, and pH-value of the waste solution0 were studied systematically

  11. A Comparative Study of Cellulose Agricultural Wastes (Almond Shell, Pistachio Shell, Walnut Shell, Tea Waste And Orange Peel for Adsorption of Violet B Dye from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Saeedeh Hashemian

    2014-12-01

    Full Text Available Adsorption of violet B azo dye from aqueous solutions was studied by different cellulose agriculturalwaste materials (almond shell (AS, pistachio shell (PS, walnut shell (WS, Tea waste (TW and orange peel (OP. Cellulose agricultural waste sorbents characterized by FTIR and SEM methods. The effects of different parameters such as contact time, pH, adsorbent dosage and initial dye concentration were studied.Maximum removal of dye was obtained at contact time of 90 min and pH 11.The adsorption of violet B was fitted by pseudo-second-order kinetic model.The Langmuir isotherm model was better fitted than Freundlichmodel. The results showed that the adsorption efficiency of violet B by cellulose agricultural waste materials is as followed: Almond shell > Orange peel > Pistachio shell > Tea waste> Walnut shell.The maximum adsorption capacity was obtained 96, 82, 71.4, 55.5 and 48.7 mg g−1 for AS, OP, PS, TW and WS, respectively.

  12. Recovery of polypropylene and polyethylene from packaging plastic wastes without contamination of chlorinated plastic films by the combination process of wet gravity separation and ozonation.

    Science.gov (United States)

    Reddy, Mallampati Srinivasa; Okuda, Tetsuji; Nakai, Satoshi; Nishijima, Wataru; Okada, Mitsumasa

    2011-08-01

    Wet gravity separation technique has been regularly practiced to separate the polypropylene (PP) and polyethylene (PE) (light plastic films) from chlorinated plastic films (CP films) (heavy plastic films). The CP films including poly vinyl chloride (PVC) and poly vinylidene chloride (PVDC) would float in water even though its density is more than 1.0g/cm(3). This is because films are twisted in which air is sometimes entrapped inside the twisted CP films in real existing recycling plant. The present research improves the current process in separating the PP and PE from plastic packaging waste (PPW), by reducing entrapped air and by increasing the hydrophilicity of the CP films surface with ozonation. The present research also measures the hydrophilicity of the CP films. In ozonation process mixing of artificial films up to 10min reduces the contact angle from 78° to 62°, and also increases the hydrophilicity of CP films. The previous studies also performed show that the artificial PVDC films easily settle down by the same. The effect of ozonation after the wet gravity separation on light PPW films obtained from an actual PPW recycling plant was also evaluated. Although actual light PPW films contained 1.3% of CP films however in present case all the CP films were removed from the PPW films as a settled fraction in the combination process of ozonation and wet gravity separation. The combination process of ozonation and wet gravity separation is the more beneficial process in recovering of high purity PP and PE films from the PPW films. PMID:21530222

  13. Standard practice for analysis of aqueous leachates from nuclear waste materials using inductively coupled plasma-atomic emission spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice is applicable to the determination of low concentration and trace elements in aqueous leachate solutions produced by the leaching of nuclear waste materials, using inductively coupled plasma-atomic emission spectroscopy (ICP-AES). 1.2 The nuclear waste material may be a simulated (non-radioactive) solid waste form or an actual solid radioactive waste material. 1.3 The leachate may be deionized water or any natural or simulated leachate solution containing less than 1 % total dissolved solids. 1.4 This practice should be used by analysts experienced in the use of ICP-AES, the interpretation of spectral and non-spectral interferences, and procedures for their correction. 1.5 No detailed operating instructions are provided because of differences among various makes and models of suitable ICP-AES instruments. Instead, the analyst shall follow the instructions provided by the manufacturer of the particular instrument. This test method does not address comparative accuracy of different devices...

  14. Removal of common organic solvents from aqueous waste streams via supercritical C02 extraction: a potential green approach to sustainable waste management in the pharmaceutical industry.

    Science.gov (United States)

    Leazer, Johnnie L; Gant, Sean; Houck, Anthony; Leonard, William; Welch, Christopher J

    2009-03-15

    Supercritical CO2 extraction of aqueous streams is a convenient and effective method to remove commonly used solvents of varying polarities from aqueous waste streams. The resulting aqueous layers can potentially be sewered; whereas the organic layer can be recovered for potential reuse. Supercritical fluid extraction (SFE) is a technology that is increasingly being used in commercial processes (1). Supercritical fluids are well suited for extraction of a variety of media, including solids, natural products, and liquid products. Many supercritical fluids have low critical temperatures, allowing for extractions to be done at modestly low temperatures, thus avoiding any potential thermal decomposition of the solutes under study (2). Furthermore, the CO2 solvent strength is easily tuned by adjusting the density of the supercritical fluid (The density is proportional to the pressure of the extraction process). Since many supercritical fluids are gases at ambient temperature, the extract can be concentrated by simply venting the reaction mixture to a cyclone collection vessel, using appropriate safety protocols. PMID:19368207

  15. Equilibrium, kinetic and thermodynamic studies for sorption of Ni (II from aqueous solution using formaldehyde treated waste tea leaves

    Directory of Open Access Journals (Sweden)

    Jasmin Shah

    2015-05-01

    Full Text Available The sorption characteristic of Ni (II from aqueous solution using formaldehyde treated waste tea leaves as a low cost sorbent has been studied. The effect of pH, contact time, sorbent dose, initial metal ion concentration and temperature were investigated in batch experiments. The equilibrium data were fitted into four most common isotherm models; Freundlich, Langmuir, Tempkin and Dubinin–Radushkevich (D–R. The Langmuir model described the sorption isotherm best with maximum monolayer sorption capacity of 120.50 mg g−1. Four kinetic models, pseudo-first-order, pseudo-second-order, intraparticle diffusion and Elovich were employed to explain the sorption mechanism. The kinetics of sorption data showed that the pseudo-second-order model is the best with correlation coefficient of 0.9946. The spontaneous and exothermic nature of the sorption process was revealed from thermodynamic investigations. The effect of some common alkali and alkaline earth metal ions were also studied which showed that the presence of these ions have no effect on the sorption of Ni (II. The results showed that waste tea leaves have the potential to be used as a low cost sorbent for the removal of Ni (II from aqueous solutions.

  16. Magnetic nanoparticle (Fe3O4) impregnated onto tea waste for the removal of nickel(II) from aqueous solution

    International Nuclear Information System (INIS)

    The removal of Ni(II) from aqueous solution by magnetic nanoparticles prepared and impregnated onto tea waste (Fe3O4-TW) from agriculture biomass was investigated. Magnetic nanoparticles (Fe3O4) were prepared by chemical precipitation of a Fe2+ and Fe3+ salts from aqueous solution by ammonia solution. These magnetic nanoparticles of the adsorbent Fe3O4 were characterized by surface area (BET), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Fourier Transform-Infrared Spectroscopy (FT-IR). The effects of various parameters, such as contact time, pH, concentration, adsorbent dosage and temperature were studied. The kinetics followed is first order in nature, and the value of rate constant was found to be 1.90 x 10-2 min-1 at 100 mg L-1 and 303 K. Removal efficiency decreases from 99 to 87% by increasing the concentration of Ni(II) in solution from 50 to 100 mg L-1. It was found that the adsorption of Ni(II) increases by increasing temperature from 303 to 323 K and the process is endothermic in nature. The adsorption isotherm data were fitted to Langmuir and Freundlich equation, and the Langmuir adsorption capacity, Qo, was found to be (38.3) mg g-1. The results also revealed that nanoparticle impregnated onto tea waste from agriculture biomass, can be an attractive option for metal removal from industrial effluent.

  17. Use of Ethylenediaminetetraacetic Acid as a Scavenger for Chromium from “Wet Blue” Leather Waste: Thermodynamic and Kinetics Parameters

    Directory of Open Access Journals (Sweden)

    José E. Resende

    2014-01-01

    Full Text Available One serious consequence of the current consumer society is the transformation of the environment into a waste receptacle arising from human activities. Because of the potential toxic effects of chromium solid waste containing this metal there are grounds for serious concern for the tanning and leather processing industry. The application of tannery waste as organic fertilizer has led to extensive contamination by chromium in agricultural areas and may cause the accumulation of this metal in soils and plants. This work evaluated the extraction of Cr+3 and Cr+6 contained in solid waste from the leather industry through density functional theory (DFT calculations. The Gibbs free energy calculations reveal that the chelator ethylenediaminetetraacetic acid (EDTA forms more stable complexes with metal ions of chromium compared with the structures of the complexes [Cr(NTA(H2O2] and [Cr-collagen], the latter used to simulate the protein bound chrome leather.

  18. Climate accounting for waste management, Phase I and II. Summary: Phase 1: Glass Packaging, Metal packaging, paper, cardboard, plastic and wet organic waste. Phase 2: Wood waste and residual waste from households; Klimaregnskap for avfallshaandtering, Fase I og II. Sammendrag: Fase 1: Glassemballasje, metallemballasje, papir, papp, plastemballasje og vaatorganisk avfall. Fase 2: Treavfall og restavfall fra husholdninger

    Energy Technology Data Exchange (ETDEWEB)

    Raadal, Hanne Lerche; Modahl, Ingunn Saur; Lyng, Kari-Anne

    2009-09-15

    Background. On the basis of an increased focus on emissions of greenhouse gases in general, Waste Norway wanted to prepare a climate accounting for waste management in Norway. Oestfoldforskning was engaged to undertake the project. The aim of the project has been to develop a model for the calculation of net greenhouse gas emissions from different waste types of waste glass containers, metal containers, paper, cardboard, plastic, wet organic waste, wood waste and residual waste. The model is based on life cycle methodology and is used to calculate the net greenhouse gas emissions per kg of waste for the various waste management options and waste types, as well as to calculate the net greenhouse gas emissions for waste management for including waste types and quantities of 2006. There is an emphasis on developing a model so that municipalities / waste companies or regions can develop their own climate accounting for waste management in their region, based on site-specific conditions associated with types and amounts of waste, transport distances, type of treatment, exploitation and use of waste generated energy etc. The model can also be used as the basis for the preparation of useful documentation as the basis for information about waste systems utility in general, and as a basis for strategic reviews for Waste Norway and the waste sector in particular. Conclusions: The main conclusions from the project can be summarized as follows: 1. The results of the study clearly shows that to consider only one environmental indicator is too narrow approach to form the basis for decision making for selection of waste management solutions. 2. Net greenhouse gas emissions for waste management varies greatly, both between the different types of waste and treatment methods which are reviewed. The main results of the ranking of management methods in relation to the net greenhouse effect associated with the waste types and treatment methods are as follows: Recycling of materials

  19. A study of low-cost adsorbent materials for removing Cr(VI from aqueous waste effluent

    Directory of Open Access Journals (Sweden)

    Claudia Vargas-Niño

    2011-01-01

    Full Text Available  The present paper shows very high potential for two types of solid (a commercial alumina and material obtained by composting, i.e. matured compost on Cr(VI adsorption/elimination in aqueous solution using a concentration range close to those previously detected in waste-water from Colombian industries. Both had important properties for eliminating Cr(VI, the compost being more important as it represents low-cost material. Optimal conditions for chromium adsorption on alumina and compost were established. Initial Cr(VI alumina concentration was 10 mgL-1, with 100 mL/g volume of solution per adsorbent mass, pH=2.0, 1 hour equilibrium time and 150 rpm stirring. For compost, initial Cr(VI concentration was = 3 mg L-1, 50 mL/g volume of solution per adsorbent mass, pH=2.5, 3 hour equilibrium time and 150 rpm stirring. The experiments showed that compost adsorption properties could be enhanced by adding small quantities of alumina. Compost could thus be chosen as a promising material for use in bioremediation chromium-containing waste water in a management programme for using solid waste in for minimising environmental impact.  

  20. Management of high-level waste arisen from SNF reprocessing by non-aqueous methods

    International Nuclear Information System (INIS)

    Composition, properties and outputs of high-active products and waste have been studied after pyro-electrochemical reprocessing of BN-350 and BOR-60 reactor irradiated MOX fuel. The main amount of fission products, actinides and impurities is concentrated in a small volume of solid recycled products - uranium dioxides of two types and high-active waste - phosphate deposit and spent salt electrolyte. The phosphate deposit and electrolyte are subject to the final disposal but uranium dioxides are returned to the cycle after a certain period of storage. Based on the study of waste properties it was concluded that they can be kept in sealed stainless steel containers without treatment for a long time. Both types of waste may be immobilized in phosphate glass or in monazite-type and kosnarite-type (NZP) ceramics to make an additional safety barrier before the final disposal. (authors)

  1. Revised Arrangements for the Management of Solid and Non-Aqueous Radioactive Waste - 12452

    International Nuclear Information System (INIS)

    In 2010, Atomic Weapons Establishment (AWE) identified a requirement to implement revised management arrangements for the generation, storage and disposal of radioactive waste. A thorough review of the current arrangements/processes was undertaken which included both legal compliance requirements and the identification of business improvement opportunities. On completion of this review a suitable project team was established and in 2011 an integrated Radioactive Waste Management process was implemented throughout the business. Initial results have shown measurable improvements within Radioactive Waste management compliance, operator understanding and increased business efficiency. Through the development and implementation of the revised working arrangements AWE has been able to continue to demonstrate both legal compliance to its regulators along with business efficiency and effectiveness improvements. Simple to follow process maps have improved employees understanding of Radioactive Waste management requirements, provided them with easily accessible information and ensured the business operates in a single coherent manner. The implementation of a modern electronic data management system has ensured all waste related information is easily retrievable and appropriately maintained. The additional functions that have been built into the system have reduced the potential for human error and increased the overall efficiency of the Waste Management department through the use of the automated report generation functionality. (authors)

  2. Assessment of TEES{reg_sign} applications for Wet Industrial Wastes: Energy benefit and economic analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.C.; Scheer, T.H.

    1992-02-01

    Fundamental work is catalyzed biomass pyrolysis/gasification led to the Thermochemical Environmental Energy System (TEES{reg_sign}) concept, a means of converting moist biomass feedstocks to high-value fuel gases such as methane. A low-temperature (350{degrees}C), pressurized (3100 psig) reaction environment and a nickel catalyst are used to reduce volumes of very high-moisture wastes such as food processing byproducts while producing useful quantities of energy. A study was conducted to assess the economic viability of a range of potential applications of the process. Cases examined included feedstocks of cheese whey, grape pomace, spent grain, and an organic chemical waste stream. The analysis indicated that only the organic chemical waste process is economically attractive in the existing energy/economic environment. However, food processing cases will become attractive as alternative disposal practices are curtailed and energy prices rise.

  3. DESTRUCTION OF TETRAPHENYLBORATE IN TANK 48H USING WET AIR OXIDATION BATCH BENCH SCALE AUTOCLAVE TESTING WITH ACTUAL RADIOACTIVE TANK 48H WASTE

    Energy Technology Data Exchange (ETDEWEB)

    Adu-Wusu, K; Paul Burket, P

    2009-03-31

    Wet Air Oxidation (WAO) is one of the two technologies being considered for the destruction of Tetraphenylborate (TPB) in Tank 48H. Batch bench-scale autoclave testing with radioactive (actual) Tank 48H waste is among the tests required in the WAO Technology Maturation Plan. The goal of the autoclave testing is to validate that the simulant being used for extensive WAO vendor testing adequately represents the Tank 48H waste. The test objective was to demonstrate comparable test results when running simulated waste and real waste under similar test conditions. Specifically: (1) Confirm the TPB destruction efficiency and rate (same reaction times) obtained from comparable simulant tests, (2) Determine the destruction efficiency of other organics including biphenyl, (3) Identify and quantify the reaction byproducts, and (4) Determine off-gas composition. Batch bench-scale stirred autoclave tests were conducted with simulated and actual Tank 48H wastes at SRNL. Experimental conditions were chosen based on continuous-flow pilot-scale simulant testing performed at Siemens Water Technologies Corporation (SWT) in Rothschild, Wisconsin. The following items were demonstrated as a result of this testing. (1) Tetraphenylborate was destroyed to below detection limits during the 1-hour reaction time at 280 C. Destruction efficiency of TPB was > 99.997%. (2) Other organics (TPB associated compounds), except biphenyl, were destroyed to below their respective detection limits. Biphenyl was partially destroyed in the process, mainly due to its propensity to reside in the vapor phase during the WAO reaction. Biphenyl is expected to be removed in the gas phase during the actual process, which is a continuous-flow system. (3) Reaction byproducts, remnants of MST, and the PUREX sludge, were characterized in this work. Radioactive species, such as Pu, Sr-90 and Cs-137 were quantified in the filtrate and slurry samples. Notably, Cs-137, boron and potassium were shown as soluble as a

  4. Hygroscopic water uptake and dry/wet cycling compared with normal water exposure of cemented waste forms

    International Nuclear Information System (INIS)

    Considerable water uptake, formation of free liquid and leaching of activity may take place if cemented waste materials containing soluble salts are exposed to high humidity air. Another feature of importance for the structural stability of some materials is cyclic variations between water saturation and dry-out periods. The phenomena have been investigated on a laboratory scale using simulated waste in the form of cemented sodium nitrate or ion-exchange resins. Spherical samples are found to be valuable for simultaneous determination of the leaching of major components, mainly sodium, and the water uptake and swelling obtained from weight-increase measurements for the samples weighed in air and immersed in water

  5. Recovery of Pd(II) and Ru(III) from aqueous waste using inorganic ion-exchanger

    International Nuclear Information System (INIS)

    The applicability of mica minerals and zeolites for the efficient removal of valuable platinum group metals (PGMs), Pd(II) and Ru(III) from aqueous waste by sorption has been investigated. The sorption of PGMs Pd(II) onto mica-mineral, muscovite and Ru(III) onto natrolite as zeolite have been studied as a function of (i) exchanger composition, (ii) temperature at which sorption process takes place and (iii) the presence of competing cations such as Na+, K+, Mg2+. These three factors have remarkable effect on the sorption process. The synthesized gel was characterized by X-ray powder diffraction, energy dispersive spectrometry, thermogravimetric analysis and scanning electron microscopy. (author)

  6. Toluene removal by oxidation reaction in spray wet scrubber: experimental, modeling and optimization

    OpenAIRE

    Roumporn Nikom; Juntima Chungsiriporn; Charun Bunyakan

    2006-01-01

    Toluene, an important volatile organic compound (VOC), is used in many kinds of industries, such as painting, printing, coating, and petrochemical industries. The emission of toluene causes serious air pollution, odor problem, flammability problem and affects human health. This paper proposes the removal of toluene from waste air using a spray wet scrubber combining the absorption and oxidation reaction. Aqueous sodium hypochlorite (NaOCl) solution was used as the scrubbing liquid in the syst...

  7. Lixiviation of plutonium contaminated solid wastes by aqueous solution of electro-generated reducing agents

    International Nuclear Information System (INIS)

    This study concerns the development of the new concept for the decontamination of plutonium bearing solid wastes, based on the lixiviation of the wastes using electro-generated reducing agents. First, a comparative study of the kinetics of the dissolution of pure PuO2 (prepared by calcination of Pu (IV) oxalate at 450 C) in sulfuric acid media, with different reducing agents, was realized. Qualitatively these reagents can be sorted in three groups: 1 / fast kinetics for Cr(II), V(II) and U(III); 2 / slow kinetics for Ti(III); 3 / very slow kinetics for V(III) and U(VI). In order to contribute to the design of an electrochemical reactor for the generation of the reducing agents usable for the lixiviation of plutonium bearing solid wastes, the study of the diffusion coefficients of both oxidized and reduced forms of different redox couples, at different temperatures, was undertaken. The results of this study also permits, from the knowledge of the diffusional activation energy of the ions, to conclude that the dissolution of pure plutonium dioxide under the action of these reducing agents is not diffusion limited. The feasibility of the plutonium decontamination treatment of synthetic or real solid wastes was then studied at laboratory scale using electro-generated V(II), which is with Cr(II) among the best reagents. The efficiency of the treatment was good, (80 pc Pu solubilisation yield), especially in the case of cellulosic or miscellaneous organic wastes. (author)

  8. Immobilization of aqueous radioactive cesium wastes by conversion to aluminosilicate minerals

    International Nuclear Information System (INIS)

    Radioactive cesium (primarily 137Cs) is a major toxic constituent of liquid wastes from nuclear fuel processing plants. Because of the long half-life, highly penetrating radiation, and mobility of 137Cs, it is necessary to convert wastes containing this radioisotope into a solid form which will prevent movement to the biosphere during long-term storage. A method for converting cesium wastes to solid, highly insoluble, thermally stable aluminosilicate minerals is described. Aluminum silicate clays (bentonite, kaolin, or pyrophyllite) or hydrous aluminosilicate gels are reacted with basic waste solutions to form pollucite, cesium zeolite (Cs-D), Cs-F, cancrinite, or nepheline. Cesium is trapped in the aluminosilicate crystal lattice of the mineral and is permanently immobilized. The identity of the mineral product is dependent on the waste composition and the SiO2/Al2O3 ratio of the clay or gel. The stoichiometry and kinetics of mineral formation reactions are described. The products are evaluated with respect to leachability, thermal stability, and crystal morphology. (U.S.)

  9. Equilibrium modeling of removal of drimarine yello HG-3GL dye from aqueous solutions by low cost agricultural waste

    International Nuclear Information System (INIS)

    Pollution control is one of the leading issues of society today. The present study was designed to remove the Drimarine Yellow HF-3GL dye from aqueous solutions through biosorption. Sugarcane bagasse was used as biosorbent in native, acetic acid treated and immobilized form. Batch study was conducted to optimize different system variables like pH of solution, medium temperature, biosorbent concentration, initial dye concentration and contact time. Maximum dye removal was observed at pH 2, biosorbent dose of 0.05 g/50 mL and 40 degree C temperature. The equilibrium was achieved in 45-90 min. Different kinetic and equilibrium models were applied to the experimental results. The biosorption kinetic data was found to follow the pseudo second order kinetic model. Freundlich adsorption isotherm model showed a better fitness to the equilibrium data. The value of Gibbs free energy revealed that biosorption of Drimarine Yellow HF-3GL dye by native and pretreated sugarcane bagasse was a spontaneous process. Presence of salt and heavy metal ions in aqueous solution enhanced the biosorption capacity while presence of surfactants decreased the biosorption potential of biosorbent. Dye was desorbed by 1M NaOH solution. Fixed bed column study of Drimarine Yellow HF-3GL was carried out to optimize different parameters like bed height, flow rate and initial dye concentration. It was observed that biosorption capacity increases with increase in initial dye concentration and bed height but decreases with the increase in flow rate. The data of column study was explained very well by BDST model. FT-IR analysis confirmed the involvement of various functional groups, mainly hydroxyl, carboxyl and amine groups. The results proved that sugarcane bagasse waste biomass can be used as a favorable biosorbent for the removal of dyes from aqueous solutions. (author)

  10. Simultaneous production of high-quality water and electrical power from aqueous feedstock’s and waste heat by high-pressure membrane distillation

    NARCIS (Netherlands)

    Kuipers, N.J.M.; Hanemaaijer, J.H.; Brouwer, H.; Medevoort, J. van; Jansen, A.; Altena, F.; Vleuten, P. van der; Bak, H.

    2015-01-01

    A new membrane distillation (MD) concept (MemPower) has been developed for the simultaneous production of high-quality water from various aqueous feedstocks with cogeneration of mechanical power (electricity). Driven by low-grade heat (waste, solar, geothermal, etc.) a pressurized distillate can be

  11. Removal of Pb (II) from Aqueous Solutions Using Waste Tea Leaves

    OpenAIRE

    Mehrdad Cheraghi; Soheil Sobhanardakani; Raziyeh Zandipak; Bahareh Lorestani; Hajar Merrikhpour

    2015-01-01

    Background: The presence of lead in natural waters has become an important issue around the world. Lead has been identified as a highly toxic metal that can cause severe environmental and public health problems and its decontamination is of utmost importance. The aim of this work was to evaluate the adsorption of lead (Pb(II)) on waste tea leaves as a cheap purification method. Methods: In this experimental study, prepared waste tea leaves were used as adsorbent for the removal of Pb (II) ...

  12. Valorisation of Vietnamese Rice Straw Waste: Catalytic Aqueous Phase Reforming of Hydrolysate from Steam Explosion to Platform Chemicals

    Directory of Open Access Journals (Sweden)

    Cao Huong Giang

    2014-12-01

    Full Text Available A family of tungstated zirconia solid acid catalysts were synthesised via wet impregnation and subsequent thermochemical processing for the transformation of glucose to 5-hydroxymethylfurfural (HMF. Acid strength increased with tungsten loading and calcination temperature, associated with stabilisation of tetragonal zirconia. High tungsten dispersions of between 2 and 7 W atoms·nm−2 were obtained in all cases, equating to sub-monolayer coverages. Glucose isomerisation and subsequent dehydration via fructose to HMF increased with W loading and calcination temperature up to 600 °C, indicating that glucose conversion to fructose was favoured over weak Lewis acid and/or base sites associated with the zirconia support, while fructose dehydration and HMF formation was favoured over Brönsted acidic WOx clusters. Aqueous phase reforming of steam exploded rice straw hydrolysate and condensate was explored heterogeneously for the first time over a 10 wt% WZ catalyst, resulting in excellent HMF yields as high as 15% under mild reaction conditions.

  13. Adsorption of Reactive Red 198 Azo Dye fromAqueous Solution onto theWaste Coagulation Sludge of theWater Treatment Plants

    OpenAIRE

    Mahmoudi, M; G.R Moussavi; H. Asilian

    2010-01-01

    "n "n "nBackgrounds and Objectives:Much attention has been recently paid on using waste materials as adsorbents for removal of contaminants from water and wastewater. A new low cost waste was examined for its capacity to adsorb RR198, an azo reactive model dye, from an aqueous solution."nMaterials andMethods: The waste was dried, powdered and characterized before being used as an adsorbent. The effects of pH (3-10), adsorbent dose (0.2-3 g), dye concentration and contact time on the adsorptio...

  14. Poster 25. Inorganic seed materials for the decontamination of PWR aqueous wastes

    International Nuclear Information System (INIS)

    The use of several inorganic sorbents, used in combination with crossflow membrane filtration, has been studied for the reduction of Cr-51 and Sb-125 levels in a pressurised water reactor waste stream. A mixture of titanium oxide, zirconium phosphate and sodium nickel hexacyanoferrate (II) gave an overall decontamination factor of 20 at a solution pH of 4.5. (author)

  15. Zipping Wetting

    CERN Document Server

    Sbragaglia, Mauro; Pirat, Christophe; Borkent, Bram M; Lammertink, Rob G H; Wessling, Matthias; Lohse, Detlef

    2007-01-01

    Water droplets can completely wet micro-structured superhydrophobic surfaces. The {\\it dynamics} of this rapid process is analyzed by ultra-high-speed imaging. Depending on the scales of the micro-structure, the wetting fronts propagate smoothly and circularly or -- more interestingly -- in a {\\it stepwise} manner, leading to a growing {\\it square-shaped} wetted area: entering a new row perpendicular to the direction of front propagation takes milliseconds, whereas once this has happened, the row itself fills in microseconds ({\\it ``zipping''}). Numerical simulations confirm this view and are in quantitative agreement with the experiments.

  16. Wetting transitions

    International Nuclear Information System (INIS)

    When a liquid droplet is put onto a surface, two situations distinguishable by the contact angle may result. If the contact angle is zero, the droplet spreads across the surface, a situation referred to as complete wetting. On the other hand, if the contact angle is between 0 deg. and 180 deg., the droplet does not spread, a situation called partial wetting. A wetting transition is a surface phase transition from partial wetting to complete wetting. We review the key experimental findings on this transition, together with simple theoretical models that account for the experiments. The wetting transition is generally first order (discontinuous), implying a discontinuity in the first derivative of the surface free energy. In this case, if one measures the thickness of the adsorbed film beside the droplet, at the wetting transition a discontinuous jump in film thickness occurs from a microscopically thin to a thick film. We show that this can lead to the observation of metastable surface states and an accompanying hysteresis. The observed hysteresis poses, in turn, a number of questions concerning the nucleation of wetting films that we also consider here. In addition, we consider the equilibrium wetting film thickness that results from a competition between the long-range van der Waals forces and gravity. Finally, the first-order character of the wetting transition can lead to a similar transition even when the phase that does the wetting is not (yet) stable in the bulk. For such prewetting transitions, a discontinuous thin-to-thick film transition occurs off bulk coexistence. We show that, for the large variety of systems for which prewetting transitions have been observed, the behaviour is surprisingly uniform, and can be mapped onto a simple generic phase diagram. The second part of the review deals with the exceptions to the first-order nature of the wetting transition. Two different types of continuous or critical wetting transition have been reported, for which

  17. Biosorption of methylene blue from aqueous solutions by a waste biomaterial: hen feathers

    Science.gov (United States)

    Chowdhury, Shamik; Saha, Papita Das

    2012-09-01

    Biosorption potential of hen feathers (HFs) to remove methylene blue (MB) from aqueous solutions was investigated. Batch experiments were carried out as function of different process parameters such as pH, initial dye concentration, biosorbent dose and temperature. The optimum conditions for removal of MB were found to be pH 7.0, biosorbent dose = 1.0 g, and initial dye concentration = 50 mg L-1. The temperature had a strong influence on the biosorption process. Experimental biosorption data were modeled by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherms with the Langmuir isotherm showing the best fit at all temperatures studied. The maximum monolayer sorption capacity was determined as 134.76 mg g-1 at 303 K. According to the mean free energy values of sorption ( E) calculated using the D-R isotherm model, biosorption of MB onto HFs was chemisorption. Kinetic studies showed that the biosorption of MB followed pseudo second-order kinetics. The activation energy ( E a) determined using the Arrhenius equation confirmed that the biosorption involved chemical ion-exchange. Thermodynamic studies showed that the biosorption process was spontaneous and exothermic. To conclude, HFs is a promising biosorbent for MB removal from aqueous solutions.

  18. Thermodynamic study of the adsorption of chromium ions from aqueous solution on waste corn cobs material

    Directory of Open Access Journals (Sweden)

    Rafael A. Fonseca-Correa

    2014-12-01

    Full Text Available The paper shows the results of a study obtaining activated carbon from corn cobs and determining its use as an adsorbent for the removal of Cr3+ from aqueous solutions. The finely ground precursor was subjected to pyrolysis at 600 and 900 °C in a nitrogen atmosphere and chemical activation with H2O2 and HNO3. The effects of pyrolysis conditions and activation method on the physicochemical properties of the materials obtained were tested. The samples were characterised chemically and texturally. Were obtained microporous activated carbons of well-developed surface area varying from 337 to 1213 m2/g and exhibited differences acid-base character of the surface. The results obtained shows that a suitable good option of the activation procedure for corncobs permits the production of economic adsorbents with high sorption capacity for Cr3+ from aqueous solutions. A detailed study of immersion calorimetry was performed with carbons prepared from corn cobs to establish possible relationships with these materials between the enthalpies of immersion and textural and chemical parameters.

  19. Utilization of waste phosphogypsum to prepare hydroxyapatite nanoparticles and its application towards removal of fluoride from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Deyi, E-mail: xixizhang@lut.cn [College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050 (China); State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050 (China); Luo, Heming; Zheng, Liwen; Wang, Kunjie; Li, Hongxia; Wang, Yi; Feng, Huixia [College of Petrochemical Technology, Lanzhou University of Technology, Lanzhou 730050 (China)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer A novel approach on recycle of waste phosphogypsum was exploited. Black-Right-Pointing-Pointer Phosphogypsum was utilized to prepare hydroxyapatite nanoparticles with high purity. Black-Right-Pointing-Pointer nHAp derived from PG exhibits excellent adsoprtion capacity for fluoride. Black-Right-Pointing-Pointer Fluoride adsorbs onto nHAp mainly by electrostatic interaction and hydrogen bond. - Abstract: In the present study, waste phosphogypsum (PG) was utilized firstly to prepare hydroxyapatite nanoparticles (nHAp) via microwave irradiation technology. The nHAp derived from PG exhibited a hexagonal structure with the particle size about 20 nm Multiplication-Sign 60 nm and high purity. Meanwhile, the adsorption behaviour of fluoride onto the nHAp derived from PG was investigated to evaluate the potential application of this material for the treatment of the wastewater polluted with fluoride. The results indicate that the nHAp derived from PG can be used as an efficient adsorbent for the removal of fluoride from aqueous solution. The maximum adsorption capacities calculated from Langmuir-Freundlich model were 19.742, 26.108, 36.914 and 40.818 mg F{sup -}/g nHAp for 298, 308, 318 and 328 K, respectively. The pseudo-second order kinetic model was found to provide the best correlation of the used experimental data compared to the pseudo-first order and the adsorption isotherm could be well defined by Langmuir-Freundlich equation. The adsorption mechanism investigation shows that electrostatic interaction and hydrogen bond are the main driving force for fluoride uptake onto nHAp derived from waste PG.

  20. Removal of Cd, Cr, and Pb from aqueous solution by unmodified and modified agricultural wastes.

    Science.gov (United States)

    Mahmood-Ul-Hassan, Muhammad; Suthor, Vishandas; Rafique, Ejaz; Yasin, Muhammad

    2015-02-01

    The adsorption of cadmium (Cd), chromium (Cr), and lead (Pb), widely detected in wastewater, by unmodified and modified banana stalks, corn cob, and sunflower achene was explored. The three agricultural wastes were chemically modified with sodium hydroxide (NaOH), in combination with nitric acid (HNO3) and sulfuric acid (H2SO4), in order to improve their adsorptive binding capacity. The experiments were conducted as a function of contact time and initial metal ion concentrations. Of the three waste materials, corn cob had the highest adsorptive capacity for Pb than Cr and Cd. The NaOH-modified substrates had higher adsorptive capacity than the acid modified samples. The chemical treatment invariably increased the adsorption capacity between 10 and 100 %. The Langmuir maximum sorption capacity (q m) of Pb was highest (21-60 mg g(-1) of banana, 30-57 mg g(-1) of corn cob, and 23-28 mg g(-1) of sunflower achene) and that of Cd was least (4-7 mg g(-1) of banana, 14-20 mg g(-1) of corn cob, and 11-16 mg g(-1) of sunflower achene). The q m was in the order of Pb > Cr > Cd for all the three adsorbents. The results demonstrate that the agricultural waste materials used in this study could be used to remediate water polluted with heavy metals. PMID:25626568

  1. Uranium extraction from aqueous solution using dried and pyrolyzed tea and coffee wastes

    International Nuclear Information System (INIS)

    The adsorption of U(VI) onto dried and pyrolyzed tea and coffee wastes was investigated. The adsorption properties of the materials were characterized by measuring uranium uptake as a function of solution pH, kinetics and adsorption isotherms. pH profile of uranium adsorption where UO22+ is expected to be the predominant species was measured between pH 0 and 4. Both Langmuir and Freundlich adsorption models were used to describe adsorption equilibria, and corresponding constants evaluated. Using the Langmuir model, the maximum adsorption capacity of uranium by dried tea and coffee wastes was 59.5 and 34.8 mg/g, respectively at 291 K. Adsorption thermodynamic constants, ΔHdeg ΔSdeg and ΔGdeg were also calculated from adsorption data obtained at three different temperatures. Adsorption thermodynamics of uranyl ions on dried tea and coffee systems indicated spontaneous and endothermic processes. Additionally, a Lagergren pseudo-second-order kinetic model was used to fit the kinetic experimental data for both adsorbents and the constants evaluated. Dried tea and coffee wastes proved to be effective adsorbents with high capacities and significant advantage of a very low cost. (author)

  2. Permitting and solid waste management issues for the Bailly Station wet limestone Advanced Flue Gas Desulfurization (AFGD) system

    International Nuclear Information System (INIS)

    Pure Air (a general partnership between Air Products and Chemicals, Inc., and Mitsubishi Heavy Industries America, Inc.). is constructing a wet limestone co-current advanced flue gas desulfurization (AFGD) system that has technological and commercial advantages over conventional FGD systems in the United States. The AFGD system is being installed at the Northern Indiana Public Service Company's Bailly Generating Station near Gary, Indiana. The AFGD system is scheduled to be operational by the Summer, 1992. The AFGD system will remove at least 90 percent of the sulfur dioxide (SO2) in the flue gas from Boilers 7 and 8 at the Station while burning 3.2 percent sulfur coal. Also as part of testing the AFGD system, 95 percent removal of SO2 will be demonstrated on coals containing up to 4.5 percent sulfur. At the same time that SO2 is removed from the flue gas, a gypsum by-product will be produced which will be used for wallboard manufacturing. Since the AFGD system is a pollution control device, one would expect its installation to be received favorably by the public and regulatory agencies. Although the project was well received by regulatory agencies, on public group (Save the Dunes Council) was initially concerned since the project is located adjacent to the Indiana Dunes National Lakeshore. The purpose of this paper is to describe the project team's experiences in obtaining permits/approvals from regulatory agencies and in dealing with the public. 1 ref., 1 fig., 2 tabs

  3. Biogas production from presorted biowaste and municipal solid waste from Sweden : substrate characterization, wet fermentation and cash flow analysis

    OpenAIRE

    Wu, Lishan

    2014-01-01

    Due to the great demand of methane as car fuel by the local population in the state of Västmanland, Sweden, a Swedish company called Svensk Växtkraft AB needs to the triple the biogas production until year 2016. A problem is the availability of biowaste, which is nearly completed utilized in the biogas plant already. To solve this problem, the utilization of presorted municipal solid waste (MSW) is an option. This thesis is aiming at characterization of pre-sorted biowaste and municipal s...

  4. A novel agricultural waste adsorbent for the removal of lead (II) ions from aqueous solutions.

    Science.gov (United States)

    Ibrahim, M N Mohamad; Ngah, W S Wan; Norliyana, M S; Daud, W R Wan; Rafatullah, M; Sulaiman, O; Hashim, R

    2010-10-15

    The present study explores the ability of modified soda lignin (MSL) extracted from oil palm empty fruit bunches (EFB) in removing lead (II) ions from aqueous solutions. The effect of contact time, point zero charge (pH(pzc)) and pH of the solution, initial metal ion concentration and adsorbent dosage on the removal process were investigated. Furthermore, the MSL is characterized by SEM, XRF, FT-IR and surface area analysis. Equilibrium adsorption isotherms and kinetics were investigated. The experimental data were analyzed by the Langmuir, Freundlich and Temkin models of adsorption. The kinetic data obtained at different initial concentrations were analyzed using pseudo-first-order and pseudo-second-order models. The results provide strong evidence to support the hypothesis of adsorption mechanism. PMID:20619537

  5. Oxidative degradation of spent ion-exchange resins and alpha-bearing wastes in aqueous medium

    International Nuclear Information System (INIS)

    Different treatment processes of spent ion-exchange resins aiming at volume reduction are under development or on fullscale operation. A new volume reduction technique for treatment of ion-exchange resin materials was developed using hydrogen peroxide as oxidizing agent in presence of catalyst. Details information for this technique is introduced in this report. A newly developed simple and economically attractive technique for oxidative decomposition of spent ion-exchange resins was studied aiming at achieving remarkable volume and weight reduction. Different factors affecting semi-continuous oxidative degradation process e.g. effect of addition rate of oxidant, pH value, grain size of resin as well as type and concentration of catalyst were studied, keeping the reaction time and weight of resins constant for both cationite and anionite forms. In conclusion, the oxidative degradation of ion-exchange resin in aqueous medium could be considered as a very attractive process. (M.N.)

  6. Removal of cadmium (II) from aqueous solutions by adsorption on agricultural waste biomass

    International Nuclear Information System (INIS)

    This paper reports the feasibility of using various agricultural residues viz. sugarcane bagasse (SCB), maize corncob (MCC) and Jatropha oil cake (JOC) for the removal of Cd(II) from aqueous solution under different experimental conditions. Effect of various process parameters, viz., initial metal ion concentration, pH, and adsorbent dose has been studied for the removal of cadmium. Batch experiments were carried out at various pH (2-7), adsorbent dose (250-2000 mg), Cd(II) concentration (5-500 mgl-1) for a contact time of 60 min. The maximum cadmium removal capacity was shown by JOC (99.5%). The applicability of Langmuir and Freundlich isotherm suggests the formation of monolayer of Cd(II) ions onto the outer surface of the adsorbents. Maximum metal removal was observed at pH 6.0 with a contact time of 60 min at stirring speed of 250 rpm with an adsorbent dose of 20 g l-1 of the test solution. The maximum adsorption of cadmium (II) metal ions was observed at pH 6 for all the adsorbents viz; 99.5%, 99% and 85% for JOC, MCC, and SCB, respectively. Order of Cd(II) removal by various biosorbents was JOC > MCC > SCB. JOC may be an alternative biosorbent for the removal of Cd(II) ions from the aqueous solution. FT-IR spectra of the adsorbents (before use and after exhaustion) were recorded to explore number and position of the functional groups available for the binding of Cd(II) ions on to studied adsorbents. These results can be helpful in designing a batch mode system for the removal of cadmium from dilute wastewaters

  7. Mechanisms of wet oxidation by hydrogen peroxide

    International Nuclear Information System (INIS)

    A research programme is currently under way at BNL and MEL to investigate the possible use of Hydrogen Peroxide with metal ion catalysts as a wet oxidation treatment system for CEGB organic radioactive wastes. The published literature relating to the kinetics and mechanism of oxidation and decomposition reactions of hydrogen peroxide is reviewed and the links with practical waste management by wet oxidation are examined. Alternative wet oxidation systems are described and the similarities to the CEGB research effort are noted. (author)

  8. Adsorption of lanthanides in aqueous solution aiming to study of nuclear wastes

    International Nuclear Information System (INIS)

    The problem of radioactive wastes is a concern of world-wide scope, a time that does not still have a defined local for the construction of a repository for radioactive wastes of high level. One of the preliminary stages for the choice of the place more appropriate is the geologic study associated to the experimental studies of adsorption of the involved chemical species in the process. In this work, a sample of basaltic rock was used, of the South Region of the Formation Serra Geral, collected in Frederico Westphalen Town (RS), that it will be probably a candidate to the rock hostess for location of radioactive wastes. Two experiments have been carried out through, namely: 'Test Batch' and Percolating, both under atmospheric pressure, at the ambient temperature of 25 deg C, with the purpose to study the capacity of sorption of the rare earth elements - REE. The REE are used in this work in function of its analogy with the actinides, aiming at to investigate the chemistry behavior and the speciation of the same in natural waters, searching the possibility of geologic storage of radioactive wastes, a time that the adsorption of the REE depends on variables of the environment as pH, ionic strength, temperature and presence of ligands, as carbonates and constituent of surfaces of minerals. Experiment of percolating of the REE was carried through, 100ppb, in the basalt (with 80 mesh) in solutions with ionic strength 1= 0,025 M and 1=0,5 M of NaCl. pH was controlled in a range of 5,6 the 7,6 with HNO3 addition. The concentrations were analyzed by ICP-MS. The 'Batch Test' is an efficient form of studying sorption/desorption isotherms, beyond values of the reason between the distributions solid/solution and estimation of the solubility. The percolating experiment, was carried through under pH controlled around 6, and allowed to verify the behaviour of heavy REE in comparison with the light REE. (author)

  9. Partitioning of plutonium from aqueous acidic wastes using a hollow fiber supported liquid membrane technique

    International Nuclear Information System (INIS)

    Transport of Pu(IV) from 3M HNO3 solutions across Aliquat-336/ Solvesso-100 by hollow fiber supported liquid membrane (HFSLM) was studied. Permeability of Pu(IV) through a bundle of hollow fibers made-up with 20 lumens, of 67 cm2 surface area, 9 cm length and operated at a flow rate of 10-8 m3/s on recycle mode was examined. More than 80% Pu from oxalate bearing wastes generated during reconversion process could be transported through 10% Aliquat-336/Solvesso-100 into hydroxylamine hydrochloride strippant in about three runs. (author)

  10. Subcritical and supercritical water oxidation of organic, wet wastes for carbon cycling in regenerative life support systems

    Science.gov (United States)

    Ronsse, Frederik; Lasseur, Christophe; Rebeyre, Pierre; Clauwaert, Peter; Luther, Amanda; Rabaey, Korneel; Zhang, Dong Dong; López Barreiro, Diego; Prins, Wolter; Brilman, Wim

    2016-07-01

    For long-term human spaceflight missions, one of the major requirements is the regenerative life support system which has to be capable of recycling carbon, nutrients and water from both solid and liquid wastes generated by the crew and by the local production of food through living organisms (higher plants, fungi, algae, bacteria, …). The European Space Agency's Life Support System, envisioned by the MELiSSA project, consists of a 5 compartment artificial ecosystem, in which the waste receiving compartment (so-called compartment I or briefly 'CI') is based on thermophilic fermentation. However, as the waste generated by the crew compartment and food production compartment contain typical plant fibres (lignin, cellulose and hemicellulose), these recalcitrant fibres end up largely unaffected in the digestate (sludge) generated in the C-I compartment. Therefore, the C-I compartment has to be supplemented with a so-called fibre degradation unit (in short, FDU) for further oxidation or degradation of said plant fibres. A potential solution to degrading these plant fibres and other recalcitrant organics is their oxidation, by means of subcritical or supercritical water, into reusable CO2 while retaining the nutrients in an organic-free liquid effluent. By taking advantage of the altered physicochemical properties of water above or near its critical point (647 K, 22.1 MPa) - including increased solubility of non-polar compounds and oxygen, ion product and diffusivity - process conditions can be created for rapid oxidation of C into CO2. In this research, the oxidizer is provided as a hydrogen peroxide solution which, at elevated temperature, will dissociated into O2. The purpose of this study is to identify ideal process conditions which (a) ensure complete oxidation of carbon, (b) retaining the nutrients other than C in the liquid effluent and (c) require as little oxidizer as possible. Experiments were conducted on a continuous, tubular heated reactor and on batch

  11. Sorption of copper(II) from aqueous phase by waste biomass

    Energy Technology Data Exchange (ETDEWEB)

    Nagendra Rao, C.R. (Government Polytechnic, Anantapur (India)); Iyengar, L.; Venkobachar, C. (Indian Inst. of Tech., Kanpur (India))

    The objective of the present investigation is to compare three biomasses for copper uptake under different experimental conditions so as to choose the most suitable one for scaleup purposes. Ganoderma lucidum is a macrofungi, growing widely in tropical forests. Sorbent preparation requires its collection from the field. Asperigillus niger is obtained as a waste biomass from the fermentation industry. Activated sludge biomass is available from the biological waste treatment plants. The results of their potential to remove copper are presented. The copper uptake by biosorbents though, varied significantly, showed an increased trend in the range of pH 4 to 6. The increase in metal binding after alkali treatment was marginal for G. lucidum, significant for A. niger, and dramatic for sludge. Copper sorption capacities of M and M[sub c] were much higher than for other sorbents at pH 5.0. The effect of anionic ligands, like acetate and tartrate on copper uptake by raw and alkali treated biosorbents, was negligible as the predominant species in the presence of these ligands is divalent copper ion. Pyrophosphate, citrate, and EDTA had varying degrees of adverse effects on metal uptake. Thus, among the sorbents G. lucidum in its raw form is best suited for the practical application of copper removal from industrial effluents.

  12. Processing effects on the behavior of titanate waste forms in aqueous solutions

    International Nuclear Information System (INIS)

    Titanate processing parameters including temperature, waste loading, redox conditions, and additives used to promote specific phases were evaluated with respect to their effect on leaching of Cs, Mo, Ca, Sr, Ba, U, Gd, and Ti in the range of 220 to 1500C in leachates which included deionized water, acidic (pH 2), and basic (pH 12) solutions. Surface analyses and microstructural characterization were used to relate observed leaching behavior to processing parameters. Redox conditions were found to be very important with respect to Cs (and Mo) retention. Two Cs-bearing phases were found in titanate prepared under oxidizing conditions. One had a hollandite structure and the other contained Cs, Mo, Ca, and Fe as major constituents. The latter phase, which was more susceptible to leaching, was not observed in titanates prepared using adequate reducing conditions. Where applicable, a reference glass (PNL 76 to 68) was included in the leaching tests. Comparative leach rates for elements common to both waste forms were generally one to four orders of magnitude lower for the titanates within the range of conditions used. 5 figures, 1 table

  13. Potential Malaysia agricultural waste materials for the biosorption of cadmium(II) from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Foo, L.P.Y.; Tee, C.Z.; Raimy, N.R.; Hassell, D.G.; Lee, L.Y. [University of Nottingham Malaysia Campus, Semenyih, Selangor (Malaysia)

    2012-04-15

    Biosorption of cadmium(II) ions (Cd{sup 2+}) onto Ananas comosus (AC) peel, Parkia speciosa (PS) pods and Psidium guajava (PG) peel were investigated in this study. Batch sorption experiments were performed by investigating the effect of initial pH. It was found that Cd{sup 2+} uptake was highly dependent on the initial pH and Cd{sup 2+} removal efficiency was highest for PG peel, followed by AC peel and PS pods. Biosorption experiments were carried out using different initial Cd{sup 2+} concentration and the experimental data obtained was fitted to both Langmuir and Freundlich isotherms. The experimental data was found to best fit the Langmuir isotherm, and adsorption capacities of 18.21 mg/g (AC peel), 25.64 mg/g (PS pods) and 39.68 mg/g (PG peel) were obtained. Comparison with published adsorption capacities for other low-cost biosorbents indicates that PS pods and PG peel have potential as low-cost biosorbent materials for the removal of Cd{sup 2+} from aqueous solution. (orig.)

  14. Wetting Splashing

    CERN Document Server

    Tsai, Peichun; Dijkstra, Remko; Lohse, Detlef

    2010-01-01

    We present fluid dynamics videos illustrating wetting splashing-produced by water drop impact onto hydrophobic microstructures at high impact velocity ($\\sim 3$ ms$^{-1}$). The substrate consists of regular and transparent microtextures in square or hexagonal lattice, yielding a high contact angle of $\\sim 150 ^\\circ$. Our high speed top-or-bottom view recordings through the transparent surface shed light on the solid-liquid-air interfaces at impact. Despite the superhydrophobicity of the latticed micropillars (of a periodicity of $10 {\\mu}m), water droplet wets a certain central area and moreover entraps an air bubble beneath the droplet. Besides the central wet area, lamella surf on air splashing outward at high impinging velocity. The effects of micropatterns and air pressure on the impact outcome are also examined. We show that microscopic boundary condition, imposed by the solid texture, profoundly influences the macroscopic flow dynamics upon superhydrophobic surfaces at high impinging velocity. In addi...

  15. Removal of radioactive contaminants from aqueous laboratory wastes by chemical treatment

    International Nuclear Information System (INIS)

    The following conclusions can be drawn from the studies reported. The presence of suspended matter (i.e., clay) in the spiked tapwater solution improved the plutonium removals; however, the addition of clinoptilolite to the plant raw feed did not provide any noticeable improvement for plutonium removal. The addition of powdered clinoptilolite to the regular treatment in the plant significantly improved the removal of 137Cs, but had little effect on plutonium or 90Sr removal. Magnesium sulfate-lime-TSP (trisodium phosphate) treatment in the plant performed adequately, but not as well as the regular ferric sulfate-lime-TSP treatment. However, magnesium appears to be an adequate alternate during occasions of non-typical influents. A large portion of the plutonium is associated with the suspended solids matter in the waste. Autoradiographs indicate that the plutonium is generally evenly distributed, with some occasional hot spots

  16. Efficiency Study of Nickel (II and Cadmium (II Biosorption by Powder of Waste Activated Sludge from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    A.A Ebrahimi

    2011-01-01

    Full Text Available "n "n "nBackground and Objective: Nickel (II and cadmium (II are important in environmental pollutant. Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions because of the decrease in sludge problems, economical issues, high efficiency and compatibility with the environment."nMaterials and Methods: power of wasted activated sludge have been contact with nickel (II and cadmium (II solutions in 0.25 and 0.75 milli molar invarious pHs and mixing pace, at 24-26 0C temperature on batch reactor system .After two hours (continuously 5-420 min in kinetic study samples were analyzed with atomic absorption spectrophotometer."nResults:The kinetic study results show that equilibrium adsorption time for nickel (II and cadmium"n(II reached within 2 hr, but the profile curve of cadmium (II biosorption was smoother than nickel (II biosorption. Both metals adsorption followed the Langmuir model and the maximum adsorption capacity (qmax for nickel (II and cadmium (II was 0.195 and 0.37 milli mole per gram respectively. The increase in pH resulted in adsorption increase for both metals. For cadmium (II at 0.25 and 0.75 mMinitial concentration there was no adsorption at pH 2 where as nickel (0.25 mM adsorption was observed at the same pH. The optimum mixing rate for both metals was 200 rpm and this effect was more obviously in greater concentration."nConclusion: Like othe biosorbents ,wasted activated sludge showed greater capacity for cadmium(II biosorption than nickel (II. Cadmium (II in modeling and biosorption characteristics study had more conformity than nickel (II.

  17. 化工废料过磷酸钙在植物秸秆沤肥中的应用%Application of Calcium Superphosphate as Chemical Waste in the Reaction of Plant Straw Wet Compost

    Institute of Scientific and Technical Information of China (English)

    王庆雨; 林楷

    2016-01-01

    In order to investigate the influence of the chemical waste calcium superphosphate on the nitrogen loss rate and the maturity time in the reaction of plant straw wet compost, using straws, melon vines, rotten vegetables leaves, weeds and animal manures as raw materials, and using the chemical waste calcium superphosphate as additive, the reaction of wet compost was carried out in the homemade equipment. The results show that the chemical waste calcium superphosphate is helpful to reduce the loss of N and shorten the maturity time. After plant straw wet compost for 20 days, the nitrogen loss rate and germination index of the wet compost without the chemical waste calcium superphosphate are 35.8% and 64.3%, respectively, while the nitrogen loss rate and germination index of the wet compost adding the chemical waste calcium superphosphate are 15.2% and 82.8%, respectively. Good application effect of the chemical waste calcium superphosphate has been achieved in plant straw wet compost process.%为研究化工废料过磷酸钙对植物秸秆沤肥过程中氮损失率和腐熟时间的影响,以秸秆、瓜蔓、烂菜叶、杂草、畜肥为原材料,以化工废料过磷酸钙为添加剂,在自制的装置中进行沤肥。结果表明:化工废料过磷酸钙有助于减少氮的损失,缩短沤肥腐熟时间。沤肥20 d 后,沤肥过程中未添加化工废料过磷酸钙的氮损失率为35.8%,发芽指数为64.3%;而添加了化工废料过磷酸钙的氮损失率为15.2%,发芽指数为82.8%。化工废料过磷酸钙在植物秸秆沤肥过程取得了良好的应用效果。

  18. Water-soluble cellulose acetate from waste cotton fabrics and the aqueous processing of all-cellulose composites.

    Science.gov (United States)

    Cao, Jie; Sun, Xunwen; Lu, Canhui; Zhou, Zehang; Zhang, Xinxing; Yuan, Guiping

    2016-09-20

    The objective of this study is to explore the possibility of using waste cotton fabrics (WCFs) as low cost feedstock for the production of value-added products. Our previous study (Tian et al., 2014) demonstrated that acidic ionic liquids (ILs) can be highly efficient catalysts for controllable synthesis of cellulose acetate (CA) due to their dual function of swelling and catalyzing. In this study, an optimized "quasi-homogeneous" process which required a small amount of acidic ILs as catalyst was developed to synthesize water-soluble CA from WCFs. The process was optimized by varying the amounts of ILs and the reaction time. The highest conversion of water-soluble CA from WCFs reached 90.8%. The structure of the obtained water-soluble CA was characterized and compared with the original WCFs. Moreover, we demonstrate for the first time that fully bio-based and transparent all-cellulose composites can be fabricated by simple aqueous blending of the obtained water-soluble CA and two kinds of nanocelluloses (cellulose nanocrystals and cellulose nanofibrils), which is attractive for the applications in disposable packaging materials, sheet coating and binders, etc. PMID:27261730

  19. Usefulness of ANN-based model for copper removal from aqueous solutions using agro industrial waste materials

    Directory of Open Access Journals (Sweden)

    Petrović Marija S.

    2015-01-01

    Full Text Available The purpose of this study was to investigate the adsorption properties of locally available lignocelluloses biomaterials as biosorbents for the removal of copper ions from aqueous solution. Materials are generated from juice production (apricot stones and from the corn milling process (corn cob. Such solid wastes have little or no economic value and very often present a disposal problem. Using batch adsorption techniques the effects of initial Cu(II ions concentration (Ci, amount of biomass (m and volume of metal solution (V, on biosorption efficiency and capacity were studied for both materials, without any pre-treatments. The optimal parameters for both biosorbents were selected depending on a highest sorption capability of biosorbent, in removal of Cu(II. Experimental data were compared with second order polynomial regression models (SOPs and artificial neural networks (ANNs. SOPs showed acceptable coefficients of determination (0.842 - 0.997, while ANNs performed high prediction accuracy (0.980-0.986 in comparison to experimental results. [Projekat Ministarstva nauke Republike Srbije, br. TR 31003, TR 31055

  20. Optimization of Aqueous Extraction Conditions for Recovery of Phenolic Content and Antioxidant Properties from Macadamia (Macadamia tetraphylla) Skin Waste.

    Science.gov (United States)

    Dailey, Adriana; Vuong, Quan V

    2015-01-01

    The macadamia is native to Australia and is now grown commercially around the world. Macadamia skin, known as waste, has been generated abundantly, but this ample source has had limited uses as a byproduct. The aim of this study was to develop optimal aqueous extraction conditions for the recovery of phenolic compounds and antioxidant properties from macadamia skin using Response Surface Methodology (RSM). Water was selected for optimizing the extraction conditions because it is a cheap, safe, and environmentally friendly solvent. The results showed that the RSM models were reliable for the prediction and evaluation of the tested variables. Within the tested ranges, temperature (°C), time (min), and sample-to-solvent ratio (g/100 mL), and their interactions, did not significantly affect phenolic compound (TPC), flavonoid, proanthocyanidin, CUPRAC, and FRAP contents. However, the time and the sample-to-solvent ratio significantly affected DPPH antioxidant activity and the ratio significantly affected ABTS antioxidant capacity. The optimal extraction conditions for the recovery of phenolic compounds and antioxidant properties were predicted and validated at a temperature of 90 °C, a time of 20 min, and a sample-to-solvent ratio of 5 g/100 mL. At these conditions, an extract with TPC of 86 mg GAE/g, flavonoids of 30 mg RUE/g, and proanthocyanidins of 97 mg CAE/g could be prepared with potent antioxidant capacity. PMID:26783954

  1. The Predisposition of Iraqi Rice Husk to Remove Heavy Metals from Aqueous Solutions and Capitalized from Waste Residue

    Directory of Open Access Journals (Sweden)

    Mohammed Nsaif

    2013-12-01

    Full Text Available This study is deal with study the potential of Iraqi Rice Husk (IRH on the removal of three heavy metals pollutant which were (Mg, Mn and Mo ions from industrial wastewater using different design parameters by adsorption process. Results show that the removal efficiency were (93.95, 97.18 and 95.26 % for heavy metal (Mg, Mn and Mo respectively from aquatic solution decreased with increasing of initial concentration and flow rate while the removal efficiency increased with increasing absorbance material bed height, pH and feeding temperature. Statistical model is achieved to find an expression relates the overall operating parameters with the removal efficiency for each metal ions used in this investigation in a general equation (each one alone. The samples of (IRH remaining after using it in the removal of (Mg, Mn and Mo heavy metal ions above from Simulated Synthetic Aqueous Solutions (SSAS to investigate the capitalized of it in different methods. Different benefits possess which are: remove the three toxic heavy metals ions contaminated the water, get rid of agricultural waste (IRH, in the same time, produce light and more benefit hydrocarbons from n-heptane isomerization using a type Y-zeolite catalyst synthesis from remaining (IRH and prepare a cheap and active rodenticide.

  2. Optimization of Aqueous Extraction Conditions for Recovery of Phenolic Content and Antioxidant Properties from Macadamia (Macadamia tetraphylla Skin Waste

    Directory of Open Access Journals (Sweden)

    Adriana Dailey

    2015-11-01

    Full Text Available The macadamia is native to Australia and is now grown commercially around the world. Macadamia skin, known as waste, has been generated abundantly, but this ample source has had limited uses as a byproduct. The aim of this study was to develop optimal aqueous extraction conditions for the recovery of phenolic compounds and antioxidant properties from macadamia skin using Response Surface Methodology (RSM. Water was selected for optimizing the extraction conditions because it is a cheap, safe, and environmentally friendly solvent. The results showed that the RSM models were reliable for the prediction and evaluation of the tested variables. Within the tested ranges, temperature (°C, time (min, and sample-to-solvent ratio (g/100 mL, and their interactions, did not significantly affect phenolic compound (TPC, flavonoid, proanthocyanidin, CUPRAC, and FRAP contents. However, the time and the sample-to-solvent ratio significantly affected DPPH antioxidant activity and the ratio significantly affected ABTS antioxidant capacity. The optimal extraction conditions for the recovery of phenolic compounds and antioxidant properties were predicted and validated at a temperature of 90 °C, a time of 20 min, and a sample-to-solvent ratio of 5 g/100 mL. At these conditions, an extract with TPC of 86 mg GAE/g, flavonoids of 30 mg RUE/g, and proanthocyanidins of 97 mg CAE/g could be prepared with potent antioxidant capacity.

  3. Biosorption kinetic studies of heavy metal ions from aqueous solution by a mixture of vegetable waste (abstract)

    International Nuclear Information System (INIS)

    Biosorption potential of a new bio sorbent prepared from vegetable waste composed of mixture of potato and carrot peels for the removal of heavy metals such as Ni (II) and Cu (II) from aqueous solution was determined. Batch experiments were conducted to optimize parameters i.e. initial pH, temperature, contact time, initial metal concentration and bio sorbent dose and it was observed that maximum adsorption of nickel (78%) was achieved by stirring the contents for 75 min at pH 4 and 35 deg. C by using 3.0 g of bio sorbent while in the case of copper maximum removal of copper occurred at pH 2, temperature of 50 deg. C, contact time of 45 minutes, metal concentration of 30 ppm and bio sorbent dose of 2.5 g. Kinetic studies of these reactions showed that they follow a pseudo-second order reaction, while these systems fit well in the Langmuir isotherm model and Freundlich isotherm model for Ni (II) and Cu (II) ions respectively. Both neat and metal loaded bio sorbent samples were analyzed using FT-IR spectrophotometer and X-Ray Florescence spectrometer in order to confirm the bio sorption of Ni (II) and Cu (II) and results have revealed that the metals are present in the spent bio sorbent. (author)

  4. Sustainable High Quality Recycling of Aggregates from Waste-to-Energy, Treated in a Wet Bottom Ash Processing Installation, for Use in Concrete Products

    Directory of Open Access Journals (Sweden)

    Philip Van den Heede

    2015-12-01

    Full Text Available Nowadays, more efforts towards sustainability are required from the concrete industry. Replacing traditional aggregates by recycled bottom ash (BA from municipal solid waste incineration can contribute to this goal. Until now, only partial replacement has been considered to keep the concrete workability, strength and durability under control. In this research, the feasibility of a full aggregate replacement was investigated for producing prefabricated Lego bricks. It was found that the required compressive strength class for this purpose (C20/25 could be achieved. Nevertheless, a thorough understanding of the BA properties is needed to overcome other issues. As BA is highly absorptive, the concrete’s water demand is high. This workability issue can be dealt with by subjecting the fine BA fraction to a crushing operation to eliminate the porous elements and by pre-wetting the fine and coarse BA fractions in a controlled manner. In addition, a reactive NaOH washing is needed to avoid formation of longitudinal voids and the resulting expansion due to the metallic aluminum present in the BA. Regarding the long-term behavior, heavy metal leaching and freeze-thaw exposure are not problematic, though there is susceptibility to acetic and lactic acid attack and maybe increased sensitivity to alkali-silica reaction.

  5. Ultrasound-assisted mineralization of organic compounds in aqueous liquid wastes

    International Nuclear Information System (INIS)

    Full text of publication follows: The rinsing of the nuclear installations used for the reprocessing of fuel irradiated before their final shutdown dismantling is considered by use of surface-active compounds diluted in nitric acid medium. In order to comply with the industrial vitrification specifications (carbon concentration in solution), mineralization (carbon decomposition into CO2) of liquid wastes has to be performed. An oxidation using H2O2 with nickel nitrate used as catalyst (Fenton reaction) is an efficient method for organics compounds destruction but it involves an important dilution because of added amounts of H2O2. Ultrasound associated or not with the Fenton reaction could be interesting with an aim of reducing H2O2 consumption. Indeed, it is known that water sono-lysis generates H2O2 involving radicals formation which may oxidize organics compounds. Laboratory tests have shown poor carbon oxidation performances even if associated with Fenton reaction. Efficiency is limited by nitrous acid, formed from nitric acid sono-lysis, enhancing H2O2 consumption. However, reaction mechanisms are complex and further tests, still in progress, will involve an anti nitrous agent in order to neutralize all nitrous acid and so let H2O2 operate on the organics compounds. (authors)

  6. Biosorption of clofibric acid and carbamazepine in aqueous solution by agricultural waste rice straw.

    Science.gov (United States)

    Liu, Zhanguang; Zhou, Xuefei; Chen, Xiaohua; Dai, Chaomeng; Zhang, Juan; Zhang, Yalei

    2013-12-01

    Due to their widespread use, clofibric acid (CA) and carbamazepine (CBZ) have been frequently detected simultaneously at relatively high concentrations in aquatic environments. In this study, agricultural waste rice straw was employed as a potentially low-cost, effective and easy-to-operate biosorbent (RSB) to remove CA and CBZ. The adsorption of both pharmaceuticals followed pseudo second-order kinetics, and intraparticle diffusion was an important rate-limiting step. The adsorption isotherms of both drugs were fit well with Freundlich model. The adsorption of CA onto RSB was exothermic and was more likely to be dominated by physical processes, while the adsorption of CBZ was endothermic. Solution pH was determined to be the most important factor for CA adsorption, such that the adsorption capacity of CA onto RSB increased with the decline of solution pH. In the lower range of solution pH below 3.1, the CA removal efficiency was enhanced with the increase of biosorbent dosage. The CBZ removal efficiency was enhanced with the increase of RSB dosage without pH control. The maximum adsorption capacities were 126.3 mg/g for CA and 40.0 mg/g for CBZ. PMID:24649668

  7. REMOVAL OF ARSENIC FROM AN AQUEOUS SOLUTION BY PRETREATED WASTE TEA FUNGAL BIOMASS

    Directory of Open Access Journals (Sweden)

    S. Mamisahebei , Gh. R. Jahed Khaniki, A. Torabian, S. Nasseri, K. Naddafi

    2007-04-01

    Full Text Available Arsenic contamination in water poses a serious threat on human health. The tea fungus known as Kombucha is a waste produced during black tea fermentation. The objective of this study was to examine the main aspect of a possible strategy for the removal of arsenates employing tea fungal biomass. The pretreatment of biomass with FeCl3 was found to improve the biosorption efficiency. Arsenics uptake was found to be rapid for all concentrations and reached to 79% of equilibrium capacity of biosorption in 20 min and reached equilibrium in 90 min. The pseudo second-order and first-order models described the biosorption kinetics of As (V with good correlation coefficient (R2>0.93 and better than the other equations. The data obtained from the experiment of biosorption isotherm were analyzed using the Freundlich and Langmuir isotherm models. The equation described the isotherm of As (V biosorption with relatively high correlation coefficient (R2>0.93. According to the Langmuir model, the maximum uptake capacities (qm of tea fungal biomass for As (V were obtained 3.9810-3 mmol/gr. The effect of Na+, K+, Mg+2 and Ca+2 on equilibrium capacities of As was not significant. The variation of sorption efficiency with pH showed that optimum biosorption takes place in the pH ranges of 6 to 8. Promising results were obtained in laboratory experiments and effective As (V removals were observed.

  8. Application of coals as sorbents for the removal of Cr from aqueous waste streams

    Energy Technology Data Exchange (ETDEWEB)

    Lakatos, J.; Brown, S.D.; Snape, C.E. [University of Miskolc, Miskolc (Hungary). Dept. of Analytical Chemistry

    2001-09-01

    The study reported further understanding of how various electron transfer processes operate for Cr(VI) with a view to using coals for the removal of Cr(VI) from waste streams. Skye peat, Spanish and German lignites, UK high and low volatility bituminous coals and an activated carbon were used. After treatment to remove exchangeable cations, ion exchange experiments were conducted in 0.1 M acetic acid-sodium acetate (1:1) buffer and 0.05 M sulphuric acid solutions and the slurries were agitated once a day. The ion concentrations in the solutions were determined by flame atomic absorption spectroscopy. The Cr(VI) renaming in solution was determined by the standard calorimetric 1,5-diphenylcarbazide method. Peat and low rank (Spanish Mequinenza) coal exhibited a larger capacity for Cr(VI) removal than bituminous coal. Redox mechanisms are operative coupled with the oxidation of the coal and peat surfaces. Desorption of Cr(III) formed by reduction which occurs in strongly acidic media also needs to be considered. 1 ref., 3 figs.

  9. Phosphate mine wastes reuse for phosphorus removal from aqueous solutions under dynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jellali, Salah, E-mail: salah.jallali@certe.rnrt.tn [Water Research and Technologies Centre (CERTE), Wastewater Treatment and Recycling Laboratory, Soliman (Tunisia); Wahab, Mohamed Ali; Anane, Makram [Water Research and Technologies Centre (CERTE), Wastewater Treatment and Recycling Laboratory, Soliman (Tunisia); Riahi, Khalifa [School of Engineering in Rural Equipment of Medjez El Bab, Laboratory of Chemistry and Water Quality, Medjez El Bab (Tunisia); Bousselmi, Latifa [Water Research and Technologies Centre (CERTE), Wastewater Treatment and Recycling Laboratory, Soliman (Tunisia)

    2010-12-15

    Phosphate mine slimes (PMS), an abundant waste generated from phosphate mines, was used in this study as a cost-effective adsorbent to investigate the phosphate anions removal from synthetic and urban secondary treated wastewater solutions. Dynamic experiments using laboratory reactors were carried out to study the effect of phosphate influent concentration, PMS dosage and feed flow rate on phosphate removal and a kinetic model was used to determine the phosphate mass transfer coefficients. The results show that the phosphate removal increases with influent phosphate concentration and PMS dosage. The feed flow rate has no significant effect. On the other hand, the phosphate removal from wastewater is less efficient than the synthetic solution due to anions competition process. The evaluation of phosphates mass transfer coefficients confirms the presence of anion competition phenomena and the necessity of increasing PMS dosage to provide more adsorption sites. The cost-effective and high adsorptive capability of PMS make them attractive materials for phosphate anions removal and recovery from secondary treated wastewaters with the possibility of agronomic reuse as fertilizer.

  10. Clay minerals in aqueous alteration of meteorites as analogue materials for the long term disposal of nuclear waste

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Introduction: The long term disposal of nuclear waste provides a big challenge for material science. The material waste has to be stored safely for at least 105 years. The nuclides are embedded as particles in silica glass, which is conditioned in steel containers, which again are emplaced in a clay-rich environment. Since it is difficult to estimate the long-term stability of materials in such a time frame, certain types of meteorites are used as an analogue material. Precursor materials of meteorites formed 4.56 Gy ago in the protoplanetary disk, a disk of gas and dust particles around the young sun. One of the first components to be formed was the chondrules. These spherical, silicate-rich objects formed by the quenching of silicate droplets in the protoplanetary disk. Chondrules mainly consist of silicates like olivine and pyroxene, metal and sulfide grains. These phases are often embedded in a silicate-rich glass, the mesostasis. Chondrules and other components accreted together with finer particles to form larger parent bodies, planetesimals. On some of these bodies, accreted ices melted as result of the heat created by the decay of short-lived nuclides. In the following aqueous alteration phase circulating fluids altered the materials on these bodies to varying degrees. This probably lasted more than 1 my, so meteoritic materials allow to study alteration and corrosion in a much longer time frame than possible in laboratory. Abundant larger metal grains (up to several 100 μm in size) can help to estimate corrosion processes of the steel containment. These components are embedded in a phyllosilicate-rich matrix, similar to the clay material in which the waste packages are emplaced. CR chondrites are a group of meteorites that show alteration over the whole range from type 3 (pristine, unaltered material) to 1 (completely hydrated), thus allowing the investigation of all steps in corrosion of the materials

  11. Laboratory testing of waste glass aqueous corrosion; effects of experimental parameters

    International Nuclear Information System (INIS)

    A literature survey has been performed to assess the effects of the temperature, glass surface area/leachate volume ratio, leachant composition, leachant flow rate, and glass composition (actual radioactive vs. simulated glass) used in laboratory tests on the measured glass reaction rate. The effects of these parameters must be accounted for in mechanistic models used to project glass durability over long times. Test parameters can also be utilized to highlight particular processes in laboratory tests. Waste glass corrosion results as water diffusion, ion-exchange, and hydrolysis reactions occur simultaneously to devitrify the glass and release soluble glass components into solution. The rates of these processes are interrelated by the affects of the solution chemistry and glass alteration phases on each process, and the dominant (fastest) process may change as the reaction progresses. Transport of components from the release sites into solution may also affect the observed corrosion rate. The reaction temperature will affect the rate of each process, while other parameters will affect the solution chemistry and which processes are observed during the test. The early stages of corrosion will be observed under test conditions which maintain dilute leachates and the later stages will be observed under conditions that generate more concentrated leachate solutions. Typically, water diffusion and ion-exchange reactions dominate the observed glass corrosion in dilute solutions while hydrolysis reactions dominant in more concentrated solutions. Which process(es) controls the long-term glass corrosion is not fully understood, and the long-term corrosion rate may be either transport- or reaction-limited

  12. Stripping of TBP degraded product along with actinides from organic phase generated during the remediation of the aqueous phase of spent organic waste storage tank

    International Nuclear Information System (INIS)

    Degraded products of Tri butyl phosphate (TBP) are generated during extraction of U and Pu by PUREX due to high radiation field. Sodium carbonate wash is given to clean up the TBP solvent and the wash liquid is in a separate tank along with the spent organic waste. Though the aqueous phase from this tank comes intermediate level liquid waste category, presence of the degrade products of TBP are creating problem during its treatment by ion exchange process. To remediate this waste for ion exchange treatment, the degraded products of TBP are removed by solvent extraction using spent TBP stored in the same tank as solvent. Present paper details the stripping of the TBP degraded product along with alpha activity from the organic phase

  13. The use of an agricultural waste material, Jujuba seeds for the removal of anionic dye (Congo red) from aqueous medium

    International Nuclear Information System (INIS)

    Highlights: ► We have introduced a low-cost, abundantly locally available non-conventional adsorbent in place of activated carbons. ► The kinetic data were well described by second order kinetic model and intra-particle diffusion model. ► The Langmuir and generalized isotherm models were the best fitting for the isotherm results. ► Removal capacity of Jujuba seeds is more than so many agricultural wastes. ► Relative cost of Jujuba seeds for the removal of Congo red can be compared with activated carbons - Abstract: The feasibility of using Indian Jujuba Seeds (IJS) (Zizyphus maruritiana), abundantly available in and around the Nallamalla forest in Andhra Pradesh, for the anionic dye (Congo red, CR) adsorption from aqueous solution, has been investigated as low cost and eco-friendly adsorbent. Adsorption studies were conducted on a batch process, to study the effects of contact time, initial concentration of CR, pH and temperature. Maximum colour removal was observed at pH 2. The equilibrium data was analyzed by the Langmuir, the Freundlich and the General isotherms. The data fitted well with the Langmuir model, with a maximum adsorption capacity of 55.56 mg g−1. The pseudo-second-order kinetics was the best for the adsorption of CR, by IJS (Z. maruritiana) with good correlation. Thermodynamic parameters, such as standard free energy change (ΔG°), standard enthalpy change (ΔH°) and standard entropy change (ΔS°), were analyzed. The results suggest that IJS (Z. maruritiana) is a potential low-cost adsorbent for the CR dye removal from synthetic dye wastewater.

  14. System evaluation and microbial analysis of a sulfur cycle-based wastewater treatment process for Co-treatment of simple wet flue gas desulfurization wastes with freshwater sewage.

    Science.gov (United States)

    Qian, Jin; Liu, Rulong; Wei, Li; Lu, Hui; Chen, Guang-Hao

    2015-09-01

    A sulfur cycle-based wastewater treatment process, namely the Sulfate reduction, Autotrophic denitrification and Nitrification Integrated process (SANI(®) process) has been recently developed for organics and nitrogen removal with 90% sludge minimization and 35% energy reduction in the biological treatment of saline sewage from seawater toilet flushing practice in Hong Kong. In this study, sulfate- and sulfite-rich wastes from simple wet flue gas desulfurization (WFGD) were considered as a potential low-cost sulfur source to achieve beneficial co-treatment with non-saline (freshwater) sewage in continental areas, through a Mixed Denitrification (MD)-SANI process trialed with synthetic mixture of simple WFGD wastes and freshwater sewage. The system showed 80% COD removal efficiency (specific COD removal rate of 0.26 kg COD/kg VSS/d) at an optimal pH of 7.5 and complete denitrification through MD (specific nitrogen removal rate of 0.33 kg N/kg VSS/d). Among the electron donors in MD, organics and thiosulfate could induce a much higher denitrifying activity than sulfide in terms of both NO3(-) reduction and NO2(-) reduction, suggesting a much higher nitrogen removal rate in organics-, thiosulfate- and sulfide-based MD in MD-SANI compared to sulfide alone-based autotrophic denitrification in conventional SANI(®). Diverse sulfate/sulfite-reducing bacteria (SRB) genera dominated in the bacterial community of sulfate/sulfite-reducing up-flow sludge bed (SRUSB) sludge without methane producing bacteria detected. Desulfomicrobium-like species possibly for sulfite reduction and Desulfobulbus-like species possibly for sulfate reduction are the two dominant groups with respective abundance of 24.03 and 14.91% in the SRB genera. Diverse denitrifying genera were identified in the bacterial community of anoxic up-flow sludge bed (AnUSB) sludge and the Thauera- and Thiobacillus-like species were the major taxa. These results well explained the successful operation of the lab

  15. Extraction and recovery of mercury and lead from aqueous waste streams using redox-active layered metal chalcogenides. 1998 annual progress report

    International Nuclear Information System (INIS)

    'Mercury and other highly-toxic heavy metals such as cadmium and lead are present in many aquatic environments, and the remediation of such environments or the avoidance of heavy-metal contamination in the first place is an area of active interest. In recent years tougher environmental regulations and the high initial cost of new, more effective, and more selective extractants has made the reuse of extractant materials and the minimization of secondary waste volume a focus of their scientific effort. The authors research has involved the investigation of redox-active layered metal chalcogenides as selective, effective, and redox-recyclable extractants for heavy metals from aqueous solution.'

  16. Gerenciamento de resíduos laboratoriais: recuperação de elementos e preparo para descarte final Laboratory waste management: recovery of elements and final disposal

    OpenAIRE

    Júlio Carlos Afonso; Leandro Anido Noronha; Renata Pinheiro Felipe; Nicolas Freidinger

    2003-01-01

    This work shows some laboratory waste management developed in order to recover some elements or to prepare the waste for a correct final disposal. The 25 elements chosen cover basically all chemical behaviors found for the metals in the Periodic Table. The treatments adopted were based on the classical behavior in aqueous solution (wet chemistry) but an important condition for a full success was the previous knowledge of the qualitative composition of the wastes treated. Some general trends w...

  17. A novel bio-adsorbent of mint waste for dyes remediation in aqueous environments: study and modeling of isotherms for removal of methylene Blue

    Directory of Open Access Journals (Sweden)

    Tarik Ainane

    2014-09-01

    Full Text Available The objective of this study was to investigate the possibility of using mint waste as a bioadsorbent for the removal of dye (Methylen Blue from aqueous solutions. Batch adsorption studies were carried out by monitoring the pH, the bio-adsorbent dose and the initial dye concentration. Attempts have also been made to monitor the adsorption process through Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin adsorption isotherm models. These results have demonstrated the immense potential of mint waste as a bioadsorbent for dyes remediation in polluted water and wastewater. Finally followed by the process of adsorption phenomenon was achieved by fourier transform infrared spectrometer (FTIR, the results shows that the adsorption is mechanical trapping.

  18. Surface and Hydrodynamic Forces in Wetting Films

    OpenAIRE

    Pan, Lei

    2013-01-01

    The process of froth flotation relies on using air bubbles to collect desired mineral particles dispersed in aqueous media on the surface, while leaving undesirous mineral particles behind. For a particle to be collected on the surface of a bubble, the thin liquid films (or wetting films) of water formed in between must rupture. According to the Frumkin-Derjaguin isotherm, it is necessary that wetting films can rupture when the disjoining pressures are negative. However, the negative disjoini...

  19. Biochar pyrolytically produced from municipal solid wastes for aqueous As(V) removal: adsorption property and its improvement with KOH activation.

    Science.gov (United States)

    Jin, Hongmei; Capareda, Sergio; Chang, Zhizhou; Gao, Jun; Xu, Yueding; Zhang, Jianying

    2014-10-01

    Biochar converted from waste products is being considered as an alternative adsorbent for removal of aqueous heavy metal(loid)s. In this work, experimental and modeling investigations were conducted to examine the effect of biochars pyrolytically produced from municipal solid wastes on removing aqueous As(V) before and after activated by 2M KOH solution. Results showed that the highest adsorption capacity of pristine biochars was 24.49 mg/g. The pseudo-second-order model and Langmuir adsorption isotherm model can preferably describe the adsorption process. The activated biochar showed enhanced As(V) adsorption ability with an adsorption capacity of 30.98 mg/g, which was more than 1.3 times of pristine biochars, and 2-10 times of modified biochars reported by other literatures. Increase of surface area and changes of porous texture, especially the functional groups on the surface of activated biochars are the major contributors to its more efficient adsorption of As(V). PMID:25103038

  20. Mechanisms of Copper Corrosion in Aqueous Environments. A report from the Swedish National Council for Nuclear Waste's scientific workshop, on November 16, 2009

    International Nuclear Information System (INIS)

    In 2010 the Swedish Nuclear Fuel and Waste Management Company, SKB, plans to submit its license application for the final repository of spent nuclear fuel. The proposed method is the so-called KBS-3 method and implies placing the spent nuclear fuel in copper canisters, surrounded by a buffer of bentonite clay, at 500 m depth in the bedrock. The site selected by SKB to host the repository is located in the municipality of Oesthammar on the Swedish east coast. The copper canister plays a key role in the design of the repository for spent nuclear fuel in Sweden. The long-term physical and chemical stability of copper in aqueous environments is fundamental for the safety evolution of the proposed disposal concept. However, the corrosion resistance of copper has been questioned by results obtained under anoxic conditions in aqueous solution. These observations caused some head-lines in the Swedish newspapers as well as public and political concerns. Consequently, the Swedish National Council for Nuclear Waste organized a scientific workshop on the issue 'Mechanisms of Copper Corrosion in Aqueous Environments'. The purpose of the workshop was to address the fundamental understanding of the corrosion characteristics of copper regarding oxygen-free environments, and to identify what additional information is needed to assess the validity of the proposed corrosion mechanism and its implication on the containment of spent nuclear fuel in a copper canister. This seminar report is based on the presentations and discussions at the workshop. It also includes written statements by the members of the expert panel

  1. Mechanisms of Copper Corrosion in Aqueous Environments. A report from the Swedish National Council for Nuclear Waste's scientific workshop, on November 16, 2009

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    In 2010 the Swedish Nuclear Fuel and Waste Management Company, SKB, plans to submit its license application for the final repository of spent nuclear fuel. The proposed method is the so-called KBS-3 method and implies placing the spent nuclear fuel in copper canisters, surrounded by a buffer of bentonite clay, at 500 m depth in the bedrock. The site selected by SKB to host the repository is located in the municipality of Oesthammar on the Swedish east coast. The copper canister plays a key role in the design of the repository for spent nuclear fuel in Sweden. The long-term physical and chemical stability of copper in aqueous environments is fundamental for the safety evolution of the proposed disposal concept. However, the corrosion resistance of copper has been questioned by results obtained under anoxic conditions in aqueous solution. These observations caused some head-lines in the Swedish newspapers as well as public and political concerns. Consequently, the Swedish National Council for Nuclear Waste organized a scientific workshop on the issue 'Mechanisms of Copper Corrosion in Aqueous Environments'. The purpose of the workshop was to address the fundamental understanding of the corrosion characteristics of copper regarding oxygen-free environments, and to identify what additional information is needed to assess the validity of the proposed corrosion mechanism and its implication on the containment of spent nuclear fuel in a copper canister. This seminar report is based on the presentations and discussions at the workshop. It also includes written statements by the members of the expert panel

  2. Investigations of actinides in the context of final disposal of high-level radioactive waste - trivalent actinides in aqueous solution

    International Nuclear Information System (INIS)

    This contribution presents a small piece of research work at KIT-INE dealing with the speciation of redox sensitive trivalent actinides like Pu(III), Np(III), and U(III) in aqueous solution. The redox preparation, stabilization, and speciation of trivalent actinide in aqueous systems are discussed here. The reductants investigated were rongalite, HYA (hydroxylamine hydrochloride), and AHA (acetohydroxamic acid). The time dependence of An(III) stability at different pH values was investigated. The An(III) species in aqueous solution have been characterized by UV-Vis and XANES spectroscopy. A broader overview of the work at KIT-INE is given in the oral presentation at the NUCAR2013 conference. (author)

  3. Process for the encapsulation of radioactive wastes

    International Nuclear Information System (INIS)

    Radioactive waste material, particularly radioactive ion exchange resin in the wet condition, is encapsulated in a polyurethane by dispersing the waste in an aqueous emulsion of an organic polyol, a polyisocyanate and an hydraulic cement and allowing the emulsion to set to form a monolithic block. If desired the emulsion may also contain additional filler e.g. sand or aggregate to increase the density of the final product. Preferred polyurethanes are those made from a polyester polyol and an organic diisocyanate, particularly hexamethylene diisocyanate. (author)

  4. Chemical characterization of SRP waste tank sludges and supernates

    International Nuclear Information System (INIS)

    Most high-level liquid wastes at the Savannah River Plant (SRP) are byproducts from plutonium and enriched uranium recovery processes. The high-level liquid wastes generated by these separations processes are stored in large, underground, carbon-steel tanks. The liquid wastes consist of: supernate (an aqueous solution containing sodium, nitrate, nitrite, hydroxyl, and aluminate ions), sludge (a gelatinous material containing insoluble components of the waste, such as ferric and aluminum hydroxides, and mercuric and manganese oxides), and salt cake (crystals, such as sodium nitrate, formed by evaporation of water from supernate). Analyses of SRP wastes by laser-Raman spectrometry, atomic absorption spectrometry, spark-source mass spectrometry, neutron activation analysis, colorimetry, ion chromatography, and various other wet-chemical and radiochemical methods are discussed. These analyses are useful in studies of waste tank corrosion and of forms for long-term waste storage

  5. Laboratory performance testing of an extruded bitumen containing a surrogate, sodium nitrate-based, low-level aqueous waste

    International Nuclear Information System (INIS)

    Laboratory results of a comprehensive regulatory performance test program, using an extruded bitumen and a surrogate, sodium nitrate-based waste, have been compiled at the Oak Ridge National Laboratory (ORNL). The testing has shown that the relatively viscous form of oxidized bitumen that was used has been able to meet all performance requirements. Using a 53-mm Werner and Pfleiderer extruder, operated by personnel of WasteChem Corporation of Paramus, New Jersey, laboratory-scale, molded samples of ASTM D312, type III, air-blown bitumen were prepared for laboratory performance testing. A surrogate, low-level, mixed liquid waste, formulated to represent an actual on-site waste at ORNL, was used. The mixed liquid waste contained approximately 30 wt % sodium nitrate, in addition to eight heavy metals, cold cesium, and strontium. Samples tested contained three levels of waste loading: that is, 40, 50, and 60 wt % salt. Performance test results include the 90-day American Nuclear Society (ANS) 16.1 leach test, with leach indices reported for all cations and anions, in addition to the EP toxicity test, at all levels of waste loading. Additionally, test results presented include the unconfined compressive strength and surface morphology utilizing scanning electron microscopy (SEM). Data presented include correlations between waste form loading and test results, in addition to their relationship to regulatory performance requirements

  6. Detox{sup SM} wet oxidation system studies for engineering scale up

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, D.T.; Moslander, J.E.; Zigmond, J.A. [Delphi Research, Inc., Albuquerque, NM (United States)] [and others

    1995-12-31

    Catalyzed wet oxidation utilizing iron(III) has been shown to have promise for treating many hazardous and mixed wastes. The reaction occurs at the surface of contact between an aqueous iron(III) solution and organic material. Studies with liquid- and vapor-phase organic waste surrogates have established reaction kinetics and the limits of reaction rate based on organic concentration and iron(III) diffusion. Continuing engineering studies have concentrated on reaction vessel agitator and solids feed configurations, an improved bench scale reflux condenser and reflux condenser calculations, sparging of organic compounds from the process condensate water, filtration of solids from the process solution, and flammability limits for volatile organic compounds in the headspace of the reaction vessel under the reaction conditions. Detailed engineering design and fabrication of a demonstration unit for treatment of mixed waste is in progress.

  7. Extraction and recovery of mercury and lead from aqueous waste streams using redox-active layered metal chalcogenides. Annual progress report, September 15, 1996 - September 14, 1997

    International Nuclear Information System (INIS)

    'The authors have begun to examine the extraction and recovery of heavy elements from aqueous waste streams using redox-active metal chalcogenides. They have been able to prepare extractants from known chalcogenide starting materials, studied the efficacy of the extractants for selective removal of soft metal ions from aqueous phases, studied the deactivation of extractants and the concomitant recovery of soft metal ions from the extractants, and characterized all of the solids and solutions thus far in the study. The study was proposed as two parallel tasks: Part 1 and Part 2 emphasize the study and development of known metal chalcogenide extractants and the synthesis and development of new metal chalcogenide extractants, respectively. The two tasks were divided into sub-sections that study the extractants and their chemistry as detailed below: Preparation and reactivity of metal chalcogenide host solids Extraction of target waste (guest) ions from simulated waste streams Examination of the guest-host solids recovery of the guest metal and reuse of extractant Each section of the two tasks was divided into focused subsections that detail the specific problems and solutions to those problems that were proposed. The extent to which those tasks have been accomplished and the continued efforts of the team are described in detail below. (b) Progress and Results. The DOE-supported research has proceeded largely as proposed and has been productive in its first 12 months. Two full-paper manuscripts were submitted and are currently under peer review. A third paper is in preparation and will be submitted shortly. In addition, 5 submitted or invited presentations have been made.'

  8. Adsorption of Reactive Red 198 Azo Dye fromAqueous Solution onto theWaste Coagulation Sludge of theWater Treatment Plants

    Directory of Open Access Journals (Sweden)

    M. Mahmoudi

    2010-04-01

    Full Text Available "n "n "nBackgrounds and Objectives:Much attention has been recently paid on using waste materials as adsorbents for removal of contaminants from water and wastewater. A new low cost waste was examined for its capacity to adsorb RR198, an azo reactive model dye, from an aqueous solution."nMaterials andMethods: The waste was dried, powdered and characterized before being used as an adsorbent. The effects of pH (3-10, adsorbent dose (0.2-3 g, dye concentration and contact time on the adsorption efficiency were investigated. Equilibrium study data were modeled using Langmuir and Freundlich models."nResults: The characterization analysis indicated that itwas composedmainly of ferric hydroxide. The powder had a BET and average pore size of 107 m2/g and 4.5 nm, respectively. The results showed that dye removal was highest at a solution pH of 7 to 8 and a powder dose of 2 g/L. The RR198 removal percentage decreased from 100& to 43& at 140 min contact time when the concentration of dye was increased from 25 mg/L to 100 mg/L, at optimum pH and dosage. The Langmuir equation provided the best fit for the experimental data. The maximum adsorption capacity was calculated to be 34.4 mg/g."nConclusion: According to the obtained results, the water coagulation waste sludge appears to be a suitable low cost and effcient adsorbent for removing reactive azo dyes from waste streams.

  9. Wastes disposal on board a ship. Apparatus to decompose and annihilate wet refuses bionically; Senjo no haikibutsu shori. Namagomi no bio bunkai shometsuki

    Energy Technology Data Exchange (ETDEWEB)

    Takenaka, S.

    1996-07-25

    A bionic refuse disposing and annihilating apparatus for wet refuses produced on board a ship was developed, and introduced in this paper. This apparatus uses a system that biomass as a decomposing medium is maintained dry in a disposal tank, and wet refuses are decomposed and annihilated by the biomass working only with water contained in the wet refuses themselves. The system uses a decomposing medium composed of a mixture of different kinds of organic matters mixed with various nutrients, and automatically controls absorption and exhalation of decomposing water without using a heater. Almost all of wet refuses decomposes and annihilates in twelve hours after having been charged in their original forms. The decomposing medium can be used continuously for six months to a year. Because of complete annihilation by the bionic effect, no residue is created. This system uses a normal-temperature decomposing and annihilating bionic technology, whose minimum temperature required for decomposition and annihilation is 10{degree}C or higher, and the highest permissible temperature is 75{degree}C. Dry and cool environment at about 20{degree}C is most suitable. Deodorizing function of the biomass itself as the decomposing medium suppresses odor generation. 3 figs.

  10. Cr(VI) removal in acidic aqueous solution using iron-bearing industrial solid wastes and their stabilisation with cement.

    Science.gov (United States)

    Singh, I B; Singh, D R

    2002-01-01

    In this study, iron-bearing industrial solid wastes iron filings, ETP sludge of steel and red mud of aluminium industries; were used for Cr(VI) removal at pH 3. A complete removal of Cr(VI) was found for initial 10 mg 1(-1) of 100 ml solutions in the presence of 2.5 g iron filings, 8 g ETP sludge and 10 g red mud for up to one hour of shaking at room temperature. After Cr(VI) removal, inclusion of chromium on the reacted iron filing surface was demonstrated by EDAX analysis. Leachability of chromium and iron from the reacted wastes was determined by using Toxicity Characteristics Leaching Procedure (TCLP). This test showed a very low level of leachability of chromium as Cr(III) and iron from the reacted wastes. To minimise their leachability further, Cr(VI)-reacted solid wastes were stabilised with Portland cement in their 3:1 ratio. Leachability tests of stabilised wastes by TCLP indicated a considerable decrease in leachability of chromium and iron compared with the that of reacted wastes alone. To explore the possibility of utilisation in building materials, bricks of cement-mixed Cr(VI)-reacted wastes were made and their comprehensive strength, durability and leachability under immersion conditions were measured. PMID:11918404

  11. Liberation of chromium from ferrochrome waste materials utilising aqueous ozonation and the advanced oxidation process / Yolindi van Staden

    OpenAIRE

    Van Staden, Yolindi

    2014-01-01

    During ferrochrome (FeCr) production, three types of generic chromium (Cr) containing wastes are generated, i.e. slag, bag filter dust (BFD) and venturi sludge. The loss of these Cr units contributes significantly to the loss in revenue for FeCr producers. In this study, the liberation of Cr units was investigated utilising two case study waste materials, i.e. BFD from a semi-closed submerged arc furnace (SAF) operating on acid slag and the ultrafine fraction of slag (UFS) orig...

  12. Molecular phenomena in dynamic wetting: superspreading and precursors

    OpenAIRE

    Isele-Holder, Rolf Erwin

    2015-01-01

    Wetting is a multiscale process that can be controlled simultaneously by complex flow patterns on the macroscale and contact line phenomena at the Ångstrom scale. While resolving the latter scale is often circumvented by usage of boundary conditions, there are molecular wetting phenomena in which this approach is infeasible. The focus of this study is to use molecular dynamics simulations to examine two of these phenomena: superspreading, the ultra-rapid wetting of aqueous solutions facilitat...

  13. Literature survey on solid and aqueous species of importance for nuclear waste repositories: The elements uranium, neptunium and cesium

    International Nuclear Information System (INIS)

    This document contains extensive tables listing all possible chemical compounds of species that might occur in a proposed nuclear waste repository. Most are listed as unlikely to occur under conditions predicted for the repository. Extensive data tables and reference sources are provided for those compounds that might occur on form

  14. Extraction of Theanine from Waste Liquid of Tea Polyphenol Production in Aqueous Two-phase Systems with Cationic and Anionic Surfactants

    Institute of Scientific and Technical Information of China (English)

    ZHANG Junwei; WANG Yan; PENG Qijun

    2013-01-01

    Extraction of theanine from waste liquid of tea polyphenol production was studied in aqueous surfactant two-phase system (ASTP) with cationic suffactant (CTAB) and anionic surfactant (SDS).Results indicate that the region of ASTP is narrow and there is only a two-phase region of cationic surfactant.The increase in concentrations of NaBr and Na2SO4 are beneficial to the formation of ASTP.Theanine concentration in the bottom phase increases with increasing concentration of theanine,whereas the partition coefficient and extraction rate only change a little when the concentration of theanine is above 0.2 g· L-1.With the increase of SDS concentration,the phase ratio and the partition coefficient decrease,while the extraction efficiency of theanine increases and the concentration of theaninc changes a little in the range from 2.4/7.5 to 2.8/7.2 for SDS/CTAB ratio.The temperature has a notable effect on the concentration of theanine in the bottom phase,partition coefficient and extraction rate of theanine.The increase of waste liquid decreases the phase ratio,increases the concentration and extraction rate of theanine in the bottom phase,since the protein and the saccharide enter the bottom phase with theanine.

  15. Removal of Pb(II) ions from aqueous solution by a waste mud from copper mine industry: Equilibrium, kinetic and thermodynamic study

    International Nuclear Information System (INIS)

    The objective of this study was to assess the adsorption potential of a waste mud (WM) for the removal of lead (Pb(II)) ions from aqueous solutions. The WM was activated with NaOH in order to increase its adsorption capacity. Adsorption studies were conducted in a batch system as a function of solution pH, contact time, initial Pb(II) concentration, activated-waste mud (a-WM) concentration, temperature, etc. Optimum pH was specified as 4.0. The adsorption kinetic studies indicated that the overall adsorption process was best described by pseudo-second-order kinetics. The equilibrium adsorption capacity of a-WM was obtained by using Langmuir and Freundlich isotherm models and both models fitted well. Adsorption capacity for Pb(II) was found to be 24.4 mg g-1 for 10 g L-1 of a-WM concentration. Thermodynamic parameters including the Gibbs free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo) indicated that the adsorption of Pb(II) ions on the a-WM was feasible, spontaneous and endothermic, at temperature range of 0-40 oC. Desorption studies were carried out successfully with diluted HCl solutions. The results indicate that a-WM can be used as an effective and no-cost adsorbent for the treatment of industrial wastewaters contaminated with Pb(II) ions.

  16. Investigations of actinides in the context of final disposal of high-level radioactive waste. Trivalent actinides in aqueous solution

    International Nuclear Information System (INIS)

    The speciation of redox sensitive trivalent actinides Pu(III), Np(III), and U(III) has been studied in aqueous solution. The redox preparation, stabilization, and speciation of these trivalent actinides in aqueous systems are discussed here. The reductants investigated were rongalite, hydroxylamine hydrochloride, and acetohydroxamic acid and the An(III) species have been characterized by UV-Vis and XANES spectroscopy. The results show that the effectiveness of stabilization decreases generally in the order Pu(III) > Np(III) > U(III) and that the effectiveness of each reducing agent depends on the experimental conditions. More than 80 % of Pu(III) aquo species have been stabilized up to pH 5.5, whereas the Np(III) aquo ion could be stabilized in a pH range 0-2.5, and U(III) aquo ion is sufficiently stable at pH 1.0 and below over time periods suitable for experiments. However, this study gives a basis for the characterisation of the trivalent lighter actinides involved in complexation, sorption, and solid formation reactions in the future. (author)

  17. Geochemical assessment of nuclear-waste isolation. Testing of methods for the separation of solid and aqueous phases

    International Nuclear Information System (INIS)

    Measurement of the solubilities of certain waste radionuclide compounds will be necessary to adequately assess and predict the ability of potential underground waste storage facilities to meet federally established performance criteria. During such measurements, it is usually necessary to physically separate solid and solution phases. Experiments have been conducted to test and compare the relative efficacy of three commonly used separation methods, i.e. gravity settling, centrifugation and filtration. The results indicated that sorption of solution species onto filters can occur and could potentially lead to erroneous results in solubility measurements when one is dealing with trace amounts of radionuclides in solution. The degree of retention by filters depended on the solution pH and the nature of the filter material. Of the three methods, centrifugation appeared to give the most reliable and consistent results. Filtration was found to give results comparable to centrifugation if care is taken in the selection of filter type

  18. Pilot scale study of a chemical treatment process for decontamination of aqueous radioactive waste of pakistan research reactor-1

    International Nuclear Information System (INIS)

    Chemical treatment process for the low level liquid radioactive waste generated at PINSTECH was previously optimized on lab-scale making use of coprecipitation of hydrous oxides of iron in basic medium. Ferrous sulfate was used as coagulant. Batch wise application of this procedure on pilot scale has been tested on a 1200 L batch volume of typical PINSTECH liquid waste. Different parameters and unit operations have been evaluated. The required data for the construction of a small size treatment plant envisioned can be used for demonstration/teaching purpose as well as for the decontamination of the waste effluents of the Institute. The lab-scale process parameters were verified valid on pilot scale. It was observed that reagent doses can further be economized with out any deterioration of the Decontamination Factors (DF) achieved or of any other aspect of the process. This simple, cost- effective, DF-efficient and time-smart batch wise process could be coupled with an assortment of other treatment operations thus affording universal application. Observations recorded during this study are presented. (author)

  19. Technology for commercial radioactive waste management

    International Nuclear Information System (INIS)

    Conceptual processes and facilities for treating gaseous and various transuranium (TRU) wastes produced during the past fission portion of the light water reactor fuel cycle are described in volume 2. The goal of the treatment process for TRU wastes and for long-lived radionuclides removed from the gaseous waste streams is to convert these wastes to stable products suitable for placement in geologic isolation repositories. The treatment concepts are based on available technology. They do not necessarily represent an optimum design but are representative of what could be achieved with current technology. In actual applications it is reasonable to expect that there could be some improvement over these concepts that might be reflected in either lower costs or lower environmental impacts or both. These conceptual descriptions do provide a reasonable basis for cost analysis and for development of estimates of environmental impacts. The waste treatment technologies considered here include: high-level waste solidification, packaging of fuel residue, failed equipment and noncombustible waste treatment, general trash and combustible waste treatment, degraded solvent treatment, dilute aqueous waste pretreatment, immobilization of wet and solid wastes, off-gas particle removal systems, fuel reprocessing plant dissolver off-gas treatment, process off-gas treatment, and fuel reprocessing plant atmospheric protection system

  20. A novel magnetic adsorbent based on waste litchi peels for removing Pb(II) from aqueous solution.

    Science.gov (United States)

    Jiang, Ruixue; Tian, Jiyu; Zheng, Hao; Qi, Jinqiu; Sun, Shujuan; Li, Xiaochen

    2015-05-15

    A new magnetic bioadsorbent, magnetic litchi peel (MLP), was synthesized by coating powdered litchi peel with Fe3O4, and was used for removing Pb(II) from aqueous solutions. The influencing factors, adsorption isotherms, kinetics, and thermodynamics of Pb(II) adsorption by MLP were investigated using batch assays. Optimum Pb(II) adsorption by MLP was achieved using a contact time of 120 min, an adsorbent dose of 5 g/L, and pH of 6.0. The adsorption equilibrium data conformed to the Langmuir isotherm model, yielding a maximum Pb(II) adsorption capacity of 78.74 mg/g. The adsorption kinetics for Pb(II) adsorption by MLP followed a pseudo-second-order model. The thermodynamic results suggested that Pb(II) adsorption by MLP was spontaneous and exothermic. Additionally, the magnetic adsorbent was easily and rapidly separated out of solution under an external magnetic field. PMID:25770959

  1. Removal of Reactofix golden yellow 3 RFN from aqueous solution using wheat husk-An agricultural waste

    International Nuclear Information System (INIS)

    The wheat husk, an agricultural by-product, has been activated and used as an adsorbent for the adsorption of Reactofix golden yellow 3 RFN from aqueous solution. In this work, adsorption of Reactofix golden yellow 3 RFN on wheat husk and charcoal has been studied by using batch studies. The equibrium adsorption level was determined to be a function of the solution pH, adsorbent dosage, dye concentration and contact time. The equilibrium adsorption capacities of wheat husk and charcoal for dye removal were obtained using Freundlich and Langmuir isotherms. Thermodynamic parameters such as the free energies, enthalpies and entropies of adsorption were also evaluated. Adsorption process is considered suitable for removing color, COD from wastewater

  2. Modeled Wet Nitrate Deposition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  3. Introduction to wetting phenomena

    International Nuclear Information System (INIS)

    In these lectures the field of wetting phenomena is introduced from the point of view of statistical physics. The phase transition from partial to complete wetting is discussed and examples of relevant experiments in binary liquid mixtures are given. Cahn's concept of critical-point wetting is examined in detail. Finally, a connection is drawn between wetting near bulk criticality and the universality classes of surface critical phenomena. (author)

  4. Haptic perception of wetness

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kosters, N.D.; Daanen, H.A.M.; Kappers, A.M.L.

    2011-01-01

    The sensation of wetness is well-known but barely investigated. There are no specific wetness receptors in the skin, but the sensation is mediated by temperature and pressure perception. In our study, we have measured discrimination thresholds for the haptic perception of wetness of three di erent t

  5. Environmental impact of rejected materials generated in organic fraction of municipal solid waste anaerobic digestion plants: Comparison of wet and dry process layout.

    Science.gov (United States)

    Colazo, Ana-Belén; Sánchez, Antoni; Font, Xavier; Colón, Joan

    2015-09-01

    Anaerobic digestion of source separated organic fraction of municipal solid waste is an increasing waste valorization alternative instead of incineration or landfilling of untreated biodegradable wastes. Nevertheless, a significant portion of biodegradable wastes entering the plant is lost in pre-treatments and post-treatments of anaerobic digestion facilities together with other improper materials such as plastics, paper, textile materials and metals. The rejected materials lost in these stages have two main implications: (i) less organic material enters to digesters and, as a consequence, there is a loss of biogas production and (ii) the rejected materials end up in landfills or incinerators contributing to environmental impacts such as global warming or eutrophication. The main goals of this study are (i) to estimate potential losses of biogas in the rejected solid materials generated during the pre- and post-treatments of two full-scale anaerobic digestion facilities and (ii) to evaluate the environmental burdens associated to the final disposal (landfill or incineration) of these rejected materials by means of Life Cycle Assessment. This study shows that there is a lost of potential biogas production, ranging from 8% to 15%, due to the loss of organic matter during pre-treatment stages in anaerobic digestion facilities. From an environmental point of view, the Life Cycle Assessment shows that the incineration scenario is the most favorable alternative for eight out of nine impact categories compared with the landfill scenario. The studied impact categories are Climate Change, Fossil depletion, Freshwater eutrophication, Marine eutrophication, Ozone depletion, Particulate matter formation, Photochemical oxidant formation, Terrestrial acidification and Water depletion. PMID:26123979

  6. The role of different methanogen groups evaluated by Real-Time qPCR as high-efficiency bioindicators of wet anaerobic co-digestion of organic waste

    OpenAIRE

    Traversi, Deborah; Villa, Silvia; Acri, Marco; Pietrangeli, Biancamaria; Degan, Raffaella; Gilli, Giorgio

    2011-01-01

    Methanogen populations and their domains are poorly understood; however, in recent years, research on this topic has emerged. The relevance of this field has also been enhanced by the growing economic interest in methanogen skills, particularly the production of methane from organic substrates. Management attention turned to anaerobic wastes digestion because the volume and environmental impact reductions. Methanogenesis is the biochemically limiting step of the process and the industrially i...

  7. Recovery Technology of DMF from Wet Type Polyurethane Synthetic Leather Waste Gas%聚氨酯合成革湿法生产废气中DMF的回收工艺

    Institute of Scientific and Technical Information of China (English)

    赵舜华; 宋锡瑾; 裴宁; 张景铸; 刘书庆

    2008-01-01

    A new recovery technology is developed to recycle N, N-dimethyl formamide (DMF) in waste gas from wet type polyurethane synthetic leather industry. Given that the concentration of DMF in waste gas was as low as 325.6-688.3mg·m3, it was necessary to make sure two phases contact adequately and strengthen the mass transfer by increasing contact area and enhancing the turbulence. Therefore, two-stage countercurrent absorption and two-stage fog removing system were introduced into the technology. The top section of the absorption column was filled with structured wire-ripple stainless steel packing BX500, while the lower section with sting-ripple packing CB250Y. Total height of packing material was 6m. In addition, there were both two-stage fog removing layer and high efficiency liquid distributor at the column top. All the operating parameters, including temperature, pressure, flow rate and liquid position, could be controlled by computers without manual operation, making sure the outlet gas achieved the national emission standard that the DMF concentration should be below 40mg·m3. The whole equipment could recover 237.6t of DMF each year, with the profit up to CNY 521×103.

  8. Evaluation of an Adsorbent Based on Agricultural Waste (Corn Cobs for Removal of Tyrosine and Phenylalanine from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Cibele C. O. Alves

    2013-01-01

    Full Text Available Adsorption of phenolic amino acids, such as phenylalanine and tyrosine, is quite relevant for the production of protein hydrolysates used as dietary formulations for patients suffering from congenital disorders of amino acid metabolism, such as phenylketonuria. In this study, an adsorbent prepared from corn cobs was evaluated for the removal of tyrosine (Tyr from both a single component solution and a binary aqueous solution with phenylalanine (Phe. The adsorption behavior of tyrosine was similar to that of phenylalanine in single component solutions, however, with a much lower adsorption capacity (14 mg g−1 for Tyr compared to 109 mg g−1 for Phe. Tyr adsorption kinetics was satisfactorily described by a pseudosecond-order model as it was for Phe. In adsorption equilibrium studies for binary mixtures, the presence of Tyr in Phe solutions favored Phe faster adsorption whereas the opposite behavior was observed for the presence of Phe in Tyr solutions. Such results indicate that, in binary systems, Phe will be adsorbed preferably to Tyr, and this is a welcome feature when employing the prepared adsorbent for the removal of Phe from protein hydrolysates to be used in dietary formulations for phenylketonuria treatment.

  9. Effect of biochar addition on hydrogen and methane production in two-phase anaerobic digestion of aqueous carbohydrates food waste.

    Science.gov (United States)

    Sunyoto, Nimas M S; Zhu, Mingming; Zhang, Zhezi; Zhang, Dongke

    2016-11-01

    Effect of biochar addition on hydrogen and methane production in two-phase anaerobic digestion of aqueous carbohydrates was studied using bench-scale bioreactors. The cultures with biochar additions were placed in 100ml reactors and incubated at 35°C and pH 5 for hydrogen production. The residual cultures were then used for methane production, incubated at 35°C and pH 7. Daily yields of hydrogen and methane and weekly yield of volatile fatty acids (VFA) were measured. The hydrogen and methane production potentials, rate and lag phases of the two phases were analysed using the Gompertz model. The results showed that biochar addition increased the maximum production rates of hydrogen by 32.5% and methane 41.6%, improved hydrogen yield by 31.0% and methane 10.0%, and shortened the lag phases in the two phases by 36.0% and 41.0%, respectively. Biochar addition also enhanced VFA generation during hydrogen production and VFA degradation in methane production. PMID:27474855

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

    Science.gov (United States)

    Angin, Dilek

    2014-09-01

    The use of activated carbon obtained from sour cherry (Prunus cerasus L.) stones for the removal of a basic textile dye, which is Yellow 18, from aqueous solutions at different contact times, pH values and solution temperatures was investigated. The surface area and micropore volume of chemically modified activated carbon were 1704 m(2) g(-1) and 0.984 cm(3) g(-1), respectively. The experimental data indicated that the adsorption isotherms were well described by the Langmuir equilibrium isotherm equation and the calculated adsorption capacity was 75.76 mg g(-1) at 318 K. The adsorption kinetic of Yellow 18 obeys the pseudo-second-order kinetic model. The thermodynamic parameters were calculated to estimate the nature of adsorption. The activation energy of the system was calculated as 0.71-2.36 kJ/mol. According to these results, prepared activated carbon could be used as a low-cost adsorbent to compare with the commercial activated carbon for the removal of Yellow 18 from wastewater. PMID:24656549

  11. Selective adsorption of Cr(VI) from aqueous solution by EDA-Fe3O4 nanoparticles prepared from steel pickling waste liquor

    International Nuclear Information System (INIS)

    Highlights: • Fe3O4 nanoparticles prepared from waste liquor were functionalized with EDA. • EDA-Fe3O4 nanoparticles had high adsorption capacity and selectivity for Cr(VI). • The adsorption kinetics, thermodynamics and isotherm were studied. • Electrostatic attraction and complexation were postulated as adsorption mechanisms. • EDA-Fe3O4 nanoparticles retained high capacity after several adsorption processes. - Abstract: In this study, Fe3O4 nanoparticles (NPs) prepared from steel pickling waste liquor were functionalized with ethylenediamine (EDA) to form EDA-Fe3O4 NPs for engineering applications. The obtained EDA-Fe3O4 NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface analyzer and Fourier-transform infrared (FTIR) spectroscopy. The results showed that the EDA-Fe3O4 NPs had a crystalline structure with a particle size range of 20–50 nm and a BET surface area of 28 m2 g−1. Functionalization with EDA was able to improve the adsorption selectivity of Fe3O4 for Cr(VI) in Cr(VI)/Cl−or Cr(VI)/SO42− double-mixture systems. The adsorption isotherm data fitted better to the Langmuir adsorption model, and the adsorption kinetics was better described by the pseudo-second order equation. The spontaneous and endothermic characteristics of this adsorption reaction were confirmed by thermodynamic study. Based on the results of X-ray photoelectron spectroscopy (XPS), electrostatic attraction and surface complexation between Cr(VI) and EDA-Fe3O4 NPs are postulated as mechanisms for the adsorption of Cr(VI) from aqueous solution. The EDA-Fe3O4 NPs retained a high adsorption capacity after several consecutive adsorption–desorption processes, indicating that EDA-Fe3O4 NPs serve as an excellent regenerable adsorbent for Cr(VI)

  12. Bubble-free ozone addition through ceramic membranes for wet-oxidative waste water treatment; Blasenfreier Ozoneintrag durch keramische Membranen zur nassoxidativen Abwasserbehandlung

    Energy Technology Data Exchange (ETDEWEB)

    Janknecht, P.; Wilderer, P.A. [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl und Pruefamt fuer Wasserguete- und Abfallwirtschaft

    1999-07-01

    A prerequisite for successful wet oxidation is very accurately tuned and carefully monitored process control. In the alternative, a decline in water quality is actually possible. In particular, earlier studies in the ozonification of landfill leachate encountered problems in reducing levels of AOX in the presence of halogenated hydrocarbons. Serious problems in process control may arise when ozone is conventionally added and forms bubbles in the presence of surface-active substances; this foam accumulates and is so persistent as to evade mechanical control. Since the formation of foam is directly due to gas bubbles carried in, bubble-free addition of ozone through a membrane may be a viable approach. (orig.) [German] Voraussetzung fuer den Erfolg einer Nassoxidation ist eine sehr genau eingestellte und sorgfaeltig ueberwachte Prozessfuehrung, da anderenfalls auch eine Verschlechterung der Wasserqualitaet eintreten kann; insbesondere haben sich hier bei frueheren Untersuchungen zur Ozonung von Deponiesickerwaessern Schwierigkeiten bei der Reduzierung des AOX-Wertes in Anwesenheit von halogenierten Kohlenwasserstoffen ergeben. Gravierende Schwierigkeiten in der Prozessfuehrung kann Schaum bereiten, der sich bei konventionellem Blaseneintrag des Ozons in Anwesenheit von oberflaechenaktiven Substanzen bildet, sich in der Anlage ansammelt und dabei so bestaendig ist, dass er auf mechanische Weise nicht zu kontrollieren ist. Da die Schaumbildung direkt auf die eingetragenen Gasblasen zurueckzufuehren ist, stellt der blasenfreie Eintrag von Ozon durch eine Membran einen moeglichen Loesungsansatz dar. (orig.)

  13. PREFACE: Dynamics of wetting Dynamics of wetting

    Science.gov (United States)

    Grest, Gary S.; Oshanin, Gleb; Webb, Edmund B., III

    2009-11-01

    Capillary phenomena associated with fluids wetting other condensed matter phases have drawn great scientific interest for hundreds of years; consider the recent bicentennial celebration of Thomas Young's paper on equilibrium contact angles, describing the geometric shape assumed near a three phase contact line in terms of the relevant surface energies of the constituent phases [1]. Indeed, nearly a century has passed since the seminal papers of Lucas and Washburn, describing dynamics of capillary imbibition [2, 3]. While it is generally appreciated that dynamics of fluid wetting processes are determined by the degree to which a system is out of capillary equilibrium, myriad complications exist that challenge the fundamental understanding of dynamic capillary phenomena. The topic has gathered much interest from recent Nobel laureate Pierre-Gilles de Gennes, who provided a seminal review of relevant dissipation mechanisms for fluid droplets spreading on solid surfaces [4] Although much about the dynamics of wetting has been revealed, much remains to be learned and intrinsic technological and fundamental interest in the topic drives continuing high levels of research activity. This is enabled partly by improved experimental capabilities for resolving wetting processes at increasingly finer temporal, spatial, and chemical resolution. Additionally, dynamic wetting research advances via higher fidelity computational modeling capabilities, which drive more highly refined theory development. The significance of this topic both fundamentally and technologically has resulted in a number of reviews of research activity in wetting dynamics. One recent example addresses the evaluation of existing wetting dynamics theories from an experimentalist's perspective [5]. A Current Opinion issue was recently dedicated to high temperature capillarity, including dynamics of high temperature spreading [6]. New educational tools have recently emerged for providing instruction in wetting

  14. Wetting in electrolyte solutions.

    Science.gov (United States)

    Ibagon, Ingrid; Bier, Markus; Dietrich, S

    2013-06-01

    Wetting of a charged substrate by an electrolyte solution is investigated by means of classical density functional theory applied to a lattice model. Within the present model the pure, i.e., salt-free solvent, for which all interactions are of the nearest-neighbor type only, exhibits a second-order wetting transition for all strengths of the substrate-particle and the particle-particle interactions for which the wetting transition temperature is nonzero. The influences of the substrate charge density and of the ionic strength on the wetting transition temperature and on the order of the wetting transition are studied. If the substrate is neutral, the addition of salt to the solvent changes neither the order nor the transition temperature of the wetting transition of the system. If the surface charge is nonzero, upon adding salt this continuous wetting transition changes to first-order within the wide range of substrate surface charge densities and ionic strengths studied here. As the substrate surface charge density is increased, at fixed ionic strength, the wetting transition temperature decreases and the prewetting line associated with the first-order wetting transition becomes longer. This decrease of the wetting transition temperature upon increasing the surface charge density becomes more pronounced by decreasing the ionic strength. PMID:23758391

  15. Textile dyes removal from aqueous solution using Opuntia ficus-indica fruit waste as adsorbent and its characterization.

    Science.gov (United States)

    Peláez-Cid, A A; Velázquez-Ugalde, I; Herrera-González, A M; García-Serrano, J

    2013-11-30

    For this research, three different adsorbents, one untreated and two chemically activated, were prepared from Opuntia ficus-indica fruit waste. By the construction of adsorption isotherms, its adsorption capabilities and the viability of its use in the removal of textile basic and direct type dyes were determined. It was found that the adsorbent with the most adsorption capacity for basic dyes was the one activated with NaClO, and, for direct dyes, it was the one activated with NaOH. Langmuir and Freundlich equations isotherms were applied for the analysis of the experimental data. It was found that the Freundlich model best described the adsorption behavior. The adsorption capacity was improved when the pH of the dye solution had an acid value. The specific surface area of the adsorbents was calculated by means of methylene blue adsorption at 298 K to stay within a range between 348 and 643 m(2) g(-1). The FTIR spectroscopic characterization technique, the SEM, the point of zero charge, and the elemental analysis show the chemical and physical characteristics of the studied adsorbents, which confirm the adsorption results obtained. PMID:24071717

  16. Wet oxidation of quinoline

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Kilen, H.H.

    1998-01-01

    The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 and 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomposition of quinoline were oxygen pressure and reaction temperature. whereas the reaction...... time was less important within the range studied. Nitrifying bacteria were used to measure the inhibition from wet oxidative-treated samples to study the effect of the (wet oxidation) reaction conditions. Wet oxidation made quinoline more toxic to Nitrosomonas. This was observed for Nitrobacter as well....... The combined wet oxidation and biological treatment of reaction products resulted in 91% oxidation of the parent compound to CO2 and water. Following combined wet oxidation and biological treatment the sample showed low toxicity towards Nitrosomonas and no toxicity towards Nitrobacter. (C) 1998 Elsevier...

  17. A comparison of large-scale electron beam and bench-scale 60Co irradiations of simulated aqueous waste streams

    International Nuclear Information System (INIS)

    The effectiveness of using high energy electron beam irradiation for the removal of toxic organic chemicals from water and wastewater has been demonstrated by commercial-scale experiments conducted at the Electron Beam Research Facility (EBRF) located in Miami, Florida and elsewhere. The EBRF treats various waste and water streams up to 450 l min-1 (120 gal min-1) with doses up to 8 kilogray (kGy). Many experiments have been conducted by injecting toxic organic compounds into various plant feed streams and measuring the concentrations of compound(s) before and after exposure to the electron beam at various doses. Extensive experimentation has also been performed by dissolving selected chemicals in 22,700 l (6000 gal) tank trucks of potable water to simulate contaminated groundwater, and pumping the resulting solutions through the electron beam. These large-scale experiments, although necessary to demonstrate the commercial viability of the process, require a great deal of time and effort. This paper compares the results of large-scale electron beam irradiations to those obtained from bench-scale irradiations using gamma rays generated by a 60Co source. Dose constants from exponential contaminant removal models are found to depend on the source of radiation and initial contaminant concentration. Possible reasons for observed differences such as a dose rate effect are discussed. Models for estimating electron beam dose constants from bench-scale gamma experiments are presented. Data used to compare the removal of organic compounds using gamma irradiation and electron beam irradiation are taken from the literature and a series of experiments designed to examine the effects of pH, the presence of turbidity, and initial concentration on the removal of various organic compounds (benzene, toluene, phenol, PCE, TCE and chloroform) from simulated groundwater

  18. A comparison of large-scale electron beam and bench-scale 60Co irradiations of simulated aqueous waste streams

    Science.gov (United States)

    Kurucz, Charles N.; Waite, Thomas D.; Otaño, Suzana E.; Cooper, William J.; Nickelsen, Michael G.

    2002-11-01

    The effectiveness of using high energy electron beam irradiation for the removal of toxic organic chemicals from water and wastewater has been demonstrated by commercial-scale experiments conducted at the Electron Beam Research Facility (EBRF) located in Miami, Florida and elsewhere. The EBRF treats various waste and water streams up to 450 l min -1 (120 gal min -1) with doses up to 8 kilogray (kGy). Many experiments have been conducted by injecting toxic organic compounds into various plant feed streams and measuring the concentrations of compound(s) before and after exposure to the electron beam at various doses. Extensive experimentation has also been performed by dissolving selected chemicals in 22,700 l (6000 gal) tank trucks of potable water to simulate contaminated groundwater, and pumping the resulting solutions through the electron beam. These large-scale experiments, although necessary to demonstrate the commercial viability of the process, require a great deal of time and effort. This paper compares the results of large-scale electron beam irradiations to those obtained from bench-scale irradiations using gamma rays generated by a 60Co source. Dose constants from exponential contaminant removal models are found to depend on the source of radiation and initial contaminant concentration. Possible reasons for observed differences such as a dose rate effect are discussed. Models for estimating electron beam dose constants from bench-scale gamma experiments are presented. Data used to compare the removal of organic compounds using gamma irradiation and electron beam irradiation are taken from the literature and a series of experiments designed to examine the effects of pH, the presence of turbidity, and initial concentration on the removal of various organic compounds (benzene, toluene, phenol, PCE, TCE and chloroform) from simulated groundwater.

  19. Wet Gas Compressor Performance

    OpenAIRE

    Natås, Erik

    2014-01-01

    The world’s energy demand is increasing and more attention is given to increase the recovery of gas fields. Installing a compressor near the wellhead can contribute to this. Constantly changing reservoir conditions requires the system to handle small amounts of liquid water and condensate. Wet gas compression is a cost efficient and compact alternative to liquid separation on the seabed. A wet gas compressor test facility exists at NTNU`s thermal laboratory and research on wet gas fundam...

  20. Selective adsorption of Cr(VI) from aqueous solution by EDA-Fe{sub 3}O{sub 4} nanoparticles prepared from steel pickling waste liquor

    Energy Technology Data Exchange (ETDEWEB)

    Fang, X.B. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System, Guangzhou 510006 (China); Fang, Z.Q., E-mail: zhanqiangfang@m.scnu.edu.cn [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System, Guangzhou 510006 (China); Tsang, P.K.E. [Department of Science and Environmental Studies, The Hong Kong Institute of Education, Hong Kong 00852 (China); Cheng, W.; Yan, X.M.; Zheng, L.C. [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Guangdong Technology Research Center for Ecological Management and Remediation of Urban Water System, Guangzhou 510006 (China)

    2014-09-30

    Highlights: • Fe{sub 3}O{sub 4} nanoparticles prepared from waste liquor were functionalized with EDA. • EDA-Fe{sub 3}O{sub 4} nanoparticles had high adsorption capacity and selectivity for Cr(VI). • The adsorption kinetics, thermodynamics and isotherm were studied. • Electrostatic attraction and complexation were postulated as adsorption mechanisms. • EDA-Fe{sub 3}O{sub 4} nanoparticles retained high capacity after several adsorption processes. - Abstract: In this study, Fe{sub 3}O{sub 4} nanoparticles (NPs) prepared from steel pickling waste liquor were functionalized with ethylenediamine (EDA) to form EDA-Fe{sub 3}O{sub 4} NPs for engineering applications. The obtained EDA-Fe{sub 3}O{sub 4} NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface analyzer and Fourier-transform infrared (FTIR) spectroscopy. The results showed that the EDA-Fe{sub 3}O{sub 4} NPs had a crystalline structure with a particle size range of 20–50 nm and a BET surface area of 28 m{sup 2} g{sup −1}. Functionalization with EDA was able to improve the adsorption selectivity of Fe{sub 3}O{sub 4} for Cr(VI) in Cr(VI)/Cl{sup −}or Cr(VI)/SO{sub 4}{sup 2−} double-mixture systems. The adsorption isotherm data fitted better to the Langmuir adsorption model, and the adsorption kinetics was better described by the pseudo-second order equation. The spontaneous and endothermic characteristics of this adsorption reaction were confirmed by thermodynamic study. Based on the results of X-ray photoelectron spectroscopy (XPS), electrostatic attraction and surface complexation between Cr(VI) and EDA-Fe{sub 3}O{sub 4} NPs are postulated as mechanisms for the adsorption of Cr(VI) from aqueous solution. The EDA-Fe{sub 3}O{sub 4} NPs retained a high adsorption capacity after several consecutive adsorption–desorption processes, indicating that EDA-Fe{sub 3}O{sub 4} NPs serve as an

  1. Selective adsorption of Cr(VI) from aqueous solution by EDA-Fe3O4 nanoparticles prepared from steel pickling waste liquor

    Science.gov (United States)

    Fang, X. B.; Fang, Z. Q.; Tsang, P. K. E.; Cheng, W.; Yan, X. M.; Zheng, L. C.

    2014-09-01

    In this study, Fe3O4 nanoparticles (NPs) prepared from steel pickling waste liquor were functionalized with ethylenediamine (EDA) to form EDA-Fe3O4 NPs for engineering applications. The obtained EDA-Fe3O4 NPs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface analyzer and Fourier-transform infrared (FTIR) spectroscopy. The results showed that the EDA-Fe3O4 NPs had a crystalline structure with a particle size range of 20-50 nm and a BET surface area of 28 m2 g-1. Functionalization with EDA was able to improve the adsorption selectivity of Fe3O4 for Cr(VI) in Cr(VI)/Cl-or Cr(VI)/SO42- double-mixture systems. The adsorption isotherm data fitted better to the Langmuir adsorption model, and the adsorption kinetics was better described by the pseudo-second order equation. The spontaneous and endothermic characteristics of this adsorption reaction were confirmed by thermodynamic study. Based on the results of X-ray photoelectron spectroscopy (XPS), electrostatic attraction and surface complexation between Cr(VI) and EDA-Fe3O4 NPs are postulated as mechanisms for the adsorption of Cr(VI) from aqueous solution. The EDA-Fe3O4 NPs retained a high adsorption capacity after several consecutive adsorption-desorption processes, indicating that EDA-Fe3O4 NPs serve as an excellent regenerable adsorbent for Cr(VI).

  2. Application of an aqueous two-phase micellar system to extract bromelain from pineapple (Ananas comosus) peel waste and analysis of bromelain stability in cosmetic formulations.

    Science.gov (United States)

    Spir, Lívia Genovez; Ataide, Janaína Artem; De Lencastre Novaes, Letícia Celia; Moriel, Patrícia; Mazzola, Priscila Gava; De Borba Gurpilhares, Daniela; Silveira, Edgar; Pessoa, Adalberto; Tambourgi, Elias Basile

    2015-01-01

    Bromelain is a set of proteolytic enzymes found in pineapple (Ananas comosus) tissues such as stem, fruit and leaves. Because of its proteolytic activity, bromelain has potential applications in the cosmetic, pharmaceutical, and food industries. The present study focused on the recovery of bromelain from pineapple peel by liquid-liquid extraction in aqueous two-phase micellar systems (ATPMS), using Triton X-114 (TX-114) and McIlvaine buffer, in the absence and presence of electrolytes CaCl2 and KI; the cloud points of the generated extraction systems were studied by plotting binodal curves. Based on the cloud points, three temperatures were selected for extraction: 30, 33, and 36°C for systems in the absence of salts; 40, 43, and 46°C in the presence of KI; 24, 27, and 30°C in the presence of CaCl2 . Total protein and enzymatic activities were analyzed to monitor bromelain. Employing the ATPMS chosen for extraction (0.5 M KI with 3% TX-114, at pH 6.0, at 40°C), the bromelain extract stability was assessed after incorporation into three cosmetic bases: an anhydrous gel, a cream, and a cream-gel formulation. The cream-gel formulation presented as the most appropriate base to convey bromelain, and its optimal storage conditions were found to be 4.0 ± 0.5°C. The selected ATPMS enabled the extraction of a biomolecule with high added value from waste lined-up in a cosmetic formulation, allowing for exploration of further cosmetic potential. PMID:25919128

  3. Wetting and adsorption modification in the system

    Directory of Open Access Journals (Sweden)

    Yuliya Bogdanova

    2015-09-01

    Full Text Available Regularities of wetting and adsorption modification of surfaces of continual membranes made from highly permeable glassy polymers poly[1-(trimethylsilyl-1-propyne] (PTMSP and poly(4-methyl-2-pentyn (PMP with aqueous ethanol solutions and alcohol solutions containing organic dyes (Solvent Blue 35 and Remazol Brilliant Blue were investigated. Isotherms of stress wetting of polymer membrane surface by etanol solutions were found out to have maximums in the range of concentrations corresponding to the beginning of liquid sorption into the membrane and polymer swelling. Thus, the principal possibility of optimization of nanofiltration experiments by liquid wetting angle measurements on continuous polymer membrane surfaces was shown. The presence of the dye was shown not to affect PMP wetting. But in the case of PTMSP, it leads to shear of the maximum of stress wetting isotherms to the range of higher concentrations. It was found out the effectiveness of the adsorption surface modification of continuous polymer membrane surfaces by ethanol solutions containing dyes does not dependent on chemical nature of the dye. At the same time, there are different trends in the energy characteristics of the membrane surface.

  4. Wetting films on chemically patterned surfaces.

    Science.gov (United States)

    Karakashev, Stoyan I; Stöckelhuber, Klaus W; Tsekov, Roumen

    2011-11-15

    The behavior of thin wetting films on chemically patterned surfaces was investigated. The patterning was performed by means of imprinting of micro-grid on methylated glass surface with UV-light (λ=184.8 nm). Thus imprinted image of the grid contained hydrophilic cells and hydrophobic bars on the glass surface. For this aim three different patterns of grids were utilized with small, medium and large size of cells. The experiment showed that the drainage of the wetting aqueous films was not affected by the type of surface patterning. However, after film rupturing in the cases of small and medium cells of the patterned grid the liquid from the wetting film underwent fast self-organization in form of regularly ordered droplets covering completely the cells of the grid. The droplets reduced significantly their size upon time due to evaporation. In the cases of the largest cell grid, a wet spot on the place of the imprinted grid was formed after film rupturing. This wet spot disassembled slowly in time. In addition, formation of a periodical zigzag three-phase contact line (TPCL) was observed. This is a first study from the planned series of studies on this topic. PMID:21875710

  5. Evaluation of Gross Pollutant Wet Load in Sungai Sering, Malaysia

    Science.gov (United States)

    Noor, M. S. F. M.; Sidek, L. M.; Basri, H.; Zahari, N. M.; Said, N. F. M.; Roseli, ZA; Mohd. Dom, N.

    2016-03-01

    The gross pollutant wet load of Sungai Sering catchment, a tributary of Sungai Klang was evaluated. The catchment represents an urban catchment with rapid growth rate due to urbanization process. Urbanization frequently relates to drop of stormwater quality due to many factors such as uncontrolled pollution and improper waste disposal. The study aims to improve the understanding on the wet load trapped in 10 Gross Pollutant Traps (GPTs) in the study area. The amount of wet load analysed based on data collected in the duration from August to December 2015. There is a linear relationship between the amount of gross pollutant wet load and rainfall depth.

  6. Wet Gas Compressor Transients

    OpenAIRE

    Owren, Bjørn Berge

    2014-01-01

    This master thesis considers three subtasks related to transient operation of wet gas compressors.HYSYS Dynamics is used to establish a dynamic simulation model in the first subtask. The model is designed to predict transient behavior of the compressor test facility at NTNU during dry and wet gas trip scenarios. Its steady state performance has been validated against test data. The deviation of polytropic head and suction volume flow is less than 1% for all test points but one.Dry and wet gas...

  7. Chloride interference in the analysis of dissolved organic carbon by the wet oxidation method

    Science.gov (United States)

    Aiken, G.R.

    1992-01-01

    The presence of Cl- in concentrations greater than 0.02 M is shown to interfere with the analysis of aqueous DOC concentrations by the wet oxidation method of analysis when a reaction time of 5 min is employed. Chloride competes with DOC for S2O82-, lowering the overall oxidation efficiency. The resulting HOCl from the oxidation of Cl- reacts with DOC, producing significant amounts of chlorinated intermediate compounds in addition to CO2. These compounds were found in the waste effluent from the reaction chamber and in the gas stream transporting CO2 to the detector. While a possible Cl- effect has been noted for DOC measurements in the past, it has not previously been demonstrated to be a source of error at the concentrations reported in this paper. The interference can be overcome either by increasing the digestion time or by diluting samples to contain less than 0.02 M Cl-.

  8. Adsorption and wetting.

    NARCIS (Netherlands)

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption

  9. Wetting of soluble polymers

    OpenAIRE

    Dupas, Julien

    2012-01-01

    The wetting of a soluble substrate is a situation commonly encountered in day-to-day life. For instance, the practical motivation of this study concerns the preparation of beverages using dehydrated powders, consisting of water-soluble substances such as carbohydrates. Hydrodynamical theories describing wetting onto insoluble substrates cannot account for experimental observations in the case of a liquid spreading onto a soluble substrate. Tay et al.(1) made the hypothesis that the water cont...

  10. Adsorption and wetting.

    OpenAIRE

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption and wetting are derived. The surface pressure of a film, formed by vapour adsorption on a solid surface, is calculated by integrating the vapour adsorption isotherm. The surface pressure at the sat...

  11. Microbial treatment of aqueous wastes

    International Nuclear Information System (INIS)

    1) General binding efficiencies by immobilized cells decrease in the order U > Pb > Cu > Cd. The metal binding immobilized Rhodospirillum rubrum exceeded that found for Rhodobacter capsulata. 2) The binding efficiencies for U, Pb, Cu and Cd were greatest at pH 4.5, 5.0, 5.0 and 7.0 respectively. Immobilized cells showed an increased metal-binding capacity over a wide pH range as compared those free cells. 3) The binding efficiency decreased with increasing the initial metal concentrations. 4) Uranium can easily be stripped from the immobilized cells over several binding-stripping cycles and the adsorptive capacity of the immobilized cells appeared to increase after the first few cycles. It is therefore possible to use the immobilized cells repeatedly with regeneration. (Author)

  12. Microbial treatment of aqueous wastes

    International Nuclear Information System (INIS)

    Uranium accumulated extracellularly on the surface of Rhodobacter capsulata and Rhodospirillum rubrum cells. The rate and extent accumulation were subject to environmental parameter such as pH, temperature, carbon source, trace element and interference by certain cations. Uranium accumulation by the cells was rapid and metabolism was not required for uranium uptake by both organism. Cell-bound uranium reached concentration of 22% (Rhodospirillum rubrum) and 24% (Rhdobacter capsulata)of the dry cell weight, but in the cells grown in the presence of inhibitory concentration of CoCl2, cell-bound uranium reached concentration of 27% (Rhodospirillum rubrum) and 29% (Rhodobacter capsulata) of dry cell weight. (Author)

  13. Coal combustion by wet oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

    1980-11-15

    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  14. Copper on activated carbon for catalytic wet air oxidation

    Directory of Open Access Journals (Sweden)

    Nora Dolores Martínez

    2009-03-01

    Full Text Available Textile industry is an important source of water contamination. Some of the organic contaminants cannot be eliminated by nature in a reasonable period. Heterogeneous catalytic wet air oxidation is one of the most effective methods to purify wastewater with organic contaminants. In this work, catalysts based on copper supported on activated carbon were synthesized. The activated carbons were obtained from industrial wastes (apricot core and grape stalk of San Juan, Argentina. These were impregnated with a copper salt and thermically treated in an inert atmosphere. Analysis of specific surface, pore volume, p zc, acidity, basicity and XRD patterns were made in order to characterize the catalysts. The catalytic activity was tested in the oxidation of methylene blue (MB and polyvinyl alcohol (PVA in aqueous phase with pure oxygen. Reaction tests were carried out in a Parr batch reactor at different temperatures, with a 0.2 MPa partial pressure of oxygen. The amount of unconverted organics was measured by spectrophotometry. Higher temperatures were necessary for the degradation of PVA compared to those for methylene blue.

  15. Thermal wet oxidation improves anaerobic biodegradability of raw and digested biowaste

    DEFF Research Database (Denmark)

    Lissens, G.; Thomsen, Anne Belinda; De Baere, L.;

    2004-01-01

    Anaerobic digestion of solid biowaste generally results in relatively low methane yields of 50-60% of the theoretical maximum. Increased methane recovery from organic waste would lead to reduced handling of digested solilds, lower methane emissions to the environment, and higher green energy....... Measured methane yields for raw yard waste, wet oxidized yard waste, raw food waste, and wet oxidized food waste were 345, 685, 536, and 571 mL of CH4/g of volatile suspended solids, respectively. Higher oxygen pressure during wet oxidation of digested biowaste considerably increased the total methane...... profits. The objective of this research was to enhance the anaerobic biodegradability and methane yields from different biowastes (food waste, yard waste, and digested biowaste already treated in a full-scale biogas plant (DRANCO, Belgium)) by assessing thermal wet oxidation. The biodegradability of the...

  16. WET STRENGTH PAPER REPULPING: LABORATORY EVALUATION

    Institute of Scientific and Technical Information of China (English)

    NishiK.Bhardwaj; VikasRajan; A.G.Kulkarni

    2004-01-01

    The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly allow mills to determine the most effective pulping aids to use when repulping wet strength papers. The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables, that is, repulping time, pulp consistency, soaking time, temperature, and reactant concentration in the repulping stage were examined using Plackett-Burman design. The repulping time was the most crucial & influential process variable affecting repulping characteristic and formation related properties. The more significant repulping process variables affecting pulp yield were repulping time, soaking temperature and pulp consistency whereas for formation index and feature size, repulping time, pulp consistency, soaking temperature and time were the more important variables. The formation index is increased by an increase in repulping time, pulp consistency and soaking time whereas the feature size is decreased by an increase in repulping time, soaking temperature and pulp consistency. The formation index and the rejects were more sensitive to changes in process variables than were the feature size or the pulp yield. The pulp recycled from wet strength waste paper had good physical strength properties.

  17. WET STRENGTH PAPER REPULPING:LABORATORY EVALUATION

    Institute of Scientific and Technical Information of China (English)

    Nishi K. Bhardwaj; Vikas Rajan; A.G. Kulkarni

    2004-01-01

    The recycling of wet strength papers in a normal recycling mill is often troublesome due to the severe operating conditions required to defibre wet strength papers. The various methods are presented which will quickly allow mills to determine the most effective pulping aids to use when repulping wet strength papers. The repulping of wet strength paper with inorganic chemicals was investigated in the laboratory. The effects of major variables, that is,repulping time, pulp consistency, soaking time,temperature, and reactant concentration in the repulping stage were examined using Plackett-Burman design. The repulping time was the most crucial & influential process variable affecting repulping characteristic and formation related properties. The more significant repulping process variables affecting pulp yield were repulping time,soaking temperature and pulp consistency whereas for formation index and feature size, repulping time,pulp consistency, soaking temperature and time were the more important variables. The formation index is increased by an increase in repulping time, pulp consistency and soaking time whereas the feature size is decreased by an increase in repulping time,soaking temperature and pulp consistency. The formation index and the rejects were more sensitive to changes in process variables than were the feature size or the pulp yield. The pulp recycled from wet strength waste paper had good physical strength properties.

  18. Wet storage integrity update

    International Nuclear Information System (INIS)

    This report includes information from various studies performed under the Wet Storage Task of the Spent Fuel Integrity Project of the Commercial Spent Fuel Management (CSFM) Program at Pacific Northwest Laboratory. An overview of recent developments in the technology of wet storage of spent water reactor fuel is presented. Licensee Event Reports pertaining to spent fuel pools and the associated performance of spent fuel and storage components during wet storage are discussed. The current status of fuel that was examined under the CSFM Program is described. Assessments of the effect of boric acid in spent fuel pool water on the corrosion and stress corrosion cracking of stainless steel and the stress corrosion cracking of stainless steel piping containing stagnant water at spent fuel pools are discussed. A list of pertinent publications is included. 84 references, 21 figures, 11 tables

  19. Study of the 60Co speciation in the aqueous radioactive waste of the la Hague nuclear reprocessing plant; environmental behaviour after discharges in the waters of the channel

    International Nuclear Information System (INIS)

    60Co is produced as an activation product and is present in the low-level aqueous radioactive waste released from the La Hague plant. At present, the concentration in the sea (non filtered at 0.45 μm) at the Goury site are close to or even below, the detection limit: 0.2 mBq.l-1. The 60Co speciation depends on the type of effluent considered: in the effluent A ('active'), the cobalt is in the form of a stable trivalent complex; in the effluent V (to be checked), the cobalt is in majority (50% of the activity release) in the form of particles (>0.45 μm), and then in the form of two soluble species: ionic divalent (Co2+) and some stable complexes. The evolution of the reprocessing techniques used does not affect the speciation. So, since the nuclear reprocessing plant started at the La Hague plant in 1966, the chemical species discharged in the sea shows time variation related to the evolution of the type of effluent discharged. Thus, since 1994, the particles of cobalt are the main species discharged in the Channel (the V effluents represent more than 85% of the total 60Co activity released). The effect of instantaneous dilution into the marine conditions involving a variation of pH, oxido-reduction, ionic strength, a gradient of salinity, does not interfere with the evolution of the chemical species discharged. Nevertheless, during the discharge of the V effluent, the main constituents of the sea water (Mg2+ and Ca2+) go through a precipitation. This comes with the coprecipitation of the ion Co2+ and with the particles of cobalt (complexes are not affected), and it can be responsible for an increase in the concentration in the particles. The chemical behaviour of the cobalt in the Channel is different from those of conservative element such as antimony. The ionic cobalt and the particles have a small dispersion in the water (cobalt has a very high particle/dissolved distribution factor, it is a non-conservative radionuclide). This sedimentary stock can involve a

  20. Evaluatie wet op orgaandonatie

    OpenAIRE

    Rosendal, H.; Beekum, W.T. van; Legemaate, J.; Buisen, M.A.J.M.; Hulst, E.H.; Berg, M. van den; Assink, A.; Veen, E.B. van; Davidse, W.; Swagerman, M.B.; Chorus, A.M.J.; Brodin, H.F.T.; Riet, A. van 't; van Dijk, P.

    2001-01-01

    Met de invoering van de Wet op de orgaandonatie (WOD) is een viertal doelen nagestreefd, namelijk het bieden van rechtszekerheid aan betrokkenen, het bevorderen van het aanbod van geschikte organen en weefsels, een rechtvaardige verdeling hiervan en het voorkomen van handel in organen en weefsels. De onderzoekers concluderen dat bovengenoemde doelen ten dele zijn gerealiseerd.

  1. Wetting of real surfaces

    CERN Document Server

    Bormashenko, Edward Yu

    2013-01-01

    The problem of wetting and drop dynamics on various surfaces is very interesting from both the scientificas well as thepractical viewpoint, and subject of intense research.The results are scattered across papers in journals, sothis workwill meet the need for a unifying, comprehensive work.

  2. Wet hydrate dissolution plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant with capacity of 50,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997, for increasing detergent zeolite production from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. Main goal was increasing the detergent zeolite production capacity. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution. Wet hydrate dissolution is now fully continuous, which is important for maintaining zeolite production quality, as well as for simplifying production. The wet hydrate production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start-up, and repairs. By installing additional process equipment (centrifugal pumps and dissolving reactors technological bottlenecks were overcome, and by adjusting NaOH tanks and dissolving reactors, the capacities of the process equipment was fully utilized.

  3. WET SOLIDS FLOW ENHANCEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-03-25

    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally.

  4. Wetting phenomena in electrolyte solutions

    OpenAIRE

    Ibagon, Ingrid

    2014-01-01

    The present study analyzes wetting phenomena in electrolyte solutions. They are investigated by means of classical density functional theory. First, the wetting of a charged substrate by an electrolyte solution is studied with emphasis on the influence of the substrate charge density and of the ionic strength on the wetting transition temperature and on the order of the wetting transition. The corresponding models consist of solvent particles, anions, and cations. Two mean field approaches ar...

  5. Study of wet blasting of components in nuclear power stations

    International Nuclear Information System (INIS)

    This report looks at the method of wet blasting radioactive components in nuclear power stations. The wet blaster uses pearl shaped glass beads with the dimensions of 150-250 μm mixed with water as blasting media. The improved design, providing outer operator's positions with proper radiation protection and more efficient blasting equipment has resulted in a lesser dose taken by the operators. The main reason to decontaminate components in nuclear power plants is to enable service on these components. On components like valves, pump shafts, pipes etc. oxides form and bind radiation. These components are normally situated at some distance from the reactor core and will mainly suffer from radiation from so called activation products. When a component is to be decontaminated it can be decontaminated to a radioactive level where it will be declassified. This report has found levels ranging from 150-1000 Bq/kg allowing declassification of radioactive materials. This difference is found between different countries and different organisations. The report also looks at the levels of waste generated using wet blasting. This is done by tracking the contamination to determine where it collects. It is either collected in the water treatment plant or collected in the blasting media. At Barsebaeck the waste levels, from de-contaminating nearly 800 components in one year, results in a waste volume of about 0,250 m3. This waste consists of low and medium level waste and will cost about 3 600 EURO to store. The conclusions of the report are that wet blasting is an indispensable way to treat contaminated components in modern nuclear power plants. The wet blasting equipment can be improved by using a robot enabling the operators to remotely treat components from the outer operator's positions. There they will benefit from better radiation protection thus further reduce their taken dose. The wet blasting equipment could also be used to better control the levels of radioactivity on

  6. Water Pollution and Treatments Part I: Evaluation of Organic, Inorganic and Marine Products as Adsorbents For Petroleum Pollutants Present In Aqueous Wastes

    International Nuclear Information System (INIS)

    The main objective of the present work is to perform a comparative laboratory study using an adsorption technique for oil removal from the waste water drained to sea from refineries, offshore and/or onshore petroleum installations. Different crushed adsorbent materials, namely, cotton fibers, charcoal, petroleum coke, agriculture wastes (such as, rice straws, wheat stems, milled dry leaves and lignin), inorganic adsorbents (such as sand, and bricks) and a marine Product (such as sponge) are included in this study. They were tested for oil recovery from laboratory prepared oily salt water samples. Two different Egyptian crude oils varying in their properties and several refined products (gasoline, kerosene, gas oil, diesel oil, fuel oil, lubricating oil) and skimmed oil were employed. Their adsorptive efficiencies were tested. Good results were obtained with sponge and cotton fibers. The used agricultural wastes show better adsorption compared with coke and inorganic adsorbents.

  7. Wet storage in the USA: Recent experience and directions

    International Nuclear Information System (INIS)

    Wet storage has been the only licensed option for spent fuel management for U.S. commercial power reactor operators, except for a period of commercial reprocessing at the Nuclear Fuel Services facility, 1965-71. Developments are underway to bring dry storage to licensed status in the U.S. by mid-1986. However, wet storage will remain the predominant storage method, at least beyond the turn of the century. The Nuclear Waste Policy Act of 1982 establishes current U.S. policy regarding responsibilities for spent fuel management. The Nuclear Waste Confidence Rulemaking proceedings address the viability of extended wet storage for U.S. reactors. U.S. utilities have moved aggressively to implement optimized utilization of wet storage technology, assisted in some areas by federal programs. This paper summarizes U.S. policy and regulatory aspects of wet storage and the status of several wet storage technology developments, including: dense racking; double tiering; credit for burnup in rack designs; transshipment; impacts of extended burnup; rod consolidation and pool decommissioning. (author)

  8. Spray dryer waste management

    Energy Technology Data Exchange (ETDEWEB)

    Golden, D.

    1988-03-01

    EPRI has conducted a number of studies to provide utilities with cost information on waste management for conventional wet scrubbing. Studies have characterized waste products; developed engineering designs for effective waste handling, disposal, and/or utilization; and estimated waste management costs. A study, completed in late 1986 evaluated spray dryer wastes. On a dollar-per-ton-disposed basis, spray dryer waste management costs were found to be higher than those for either conventional fly ash or scrubber sludge alone. Cost estimates for new and retrofit spray dryer applications must be revised upward from those produced earlier by EPRI.

  9. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  10. PREFACE: Wetting: introductory note

    Science.gov (United States)

    Herminghaus, S.

    2005-03-01

    The discovery of wetting as a topic of physical science dates back two hundred years, to one of the many achievements of the eminent British scholar Thomas Young. He suggested a simple equation relating the contact angle between a liquid surface and a solid substrate to the interfacial tensions involved [1], γlg cos θ = γsg - γsl (1) In modern terms, γ denotes the excess free energy per unit area of the interface indicated by its indices, with l, g and s corresponding to the liquid, gas and solid, respectively [2]. After that, wetting seems to have been largely ignored by physicists for a long time. The discovery by Gabriel Lippmann that θ may be tuned over a wide range by electrochemical means [3], and some important papers about modifications of equation~(1) due to substrate inhomogeneities [4,5] are among the rare exceptions. This changed completely during the seventies, when condensed matter physics had become enthusiastic about critical phenomena, and was vividly inspired by the development of the renormalization group by Kenneth Wilson [6]. This had solved the long standing problem of how to treat fluctuations, and to understand the universal values of bulk critical exponents. By inspection of the critical exponents of the quantities involved in equation~(1), John W Cahn discovered what he called critical point wetting: for any liquid, there should be a well-defined transition to complete wetting (i.e., θ = 0) as the critical point of the liquid is approached along the coexistence curve [7]. His paper inspired an enormous amount of further work, and may be legitimately viewed as the entrance of wetting into the realm of modern physics. Most of the publications directly following Cahn's work were theoretical papers which elaborated on wetting in relation to critical phenomena. A vast amount of interesting, and in part quite unexpected, ramifications were discovered, such as the breakdown of universality in thin film systems [8]. Simultaneously, a number

  11. Test of electron beam technology on Savannah River Laboratory low-activity aqueous waste for destruction of benzene, benzene derivatives, and bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Dougal, R.A. [Univ. of South Carolina, Columbia, SC (United States). Dept. of Electrical and Computer Engineering

    1993-08-01

    High energy radiation was studied as a means for destroying hazardous organic chemical wastes. Tests were conducted at bench scale with a {sup 60}Co source, and at full scale (387 l/min) with a 1.5 MV electron beam source. Bench scale tests for both benzene and phenol included 32 permutations of water quality factors. For some water qualities, as much as 99.99% of benzene or 90% of phenol were removed by 775 krads of {sup 60}Co irradiation. Full scale testing for destruction of benzene in a simulated waste-water mix showed loss of 97% of benzene following an 800 krad dose and 88% following a 500 krad dose. At these loss rates, approximately 5 Mrad of electron beam irradiation is required to reduce concentrations from 100 g/l to drinking water quality (5 {mu}g/l). Since many waste streams are also inhabited by bacterial populations which may affect filtering operations, the effect of irradiation on those populations was also studied. {sup 60}Co and electron beam irradiation were both lethal to the bacteria studied at irradiation levels far lower than were necessary to remove organic contaminants.

  12. Test of electron beam technology on Savannah River Laboratory low-activity aqueous waste for destruction of benzene, benzene derivatives, and bacteria

    International Nuclear Information System (INIS)

    High energy radiation was studied as a means for destroying hazardous organic chemical wastes. Tests were conducted at bench scale with a 60Co source, and at full scale (387 l/min) with a 1.5 MV electron beam source. Bench scale tests for both benzene and phenol included 32 permutations of water quality factors. For some water qualities, as much as 99.99% of benzene or 90% of phenol were removed by 775 krads of 60Co irradiation. Full scale testing for destruction of benzene in a simulated waste-water mix showed loss of 97% of benzene following an 800 krad dose and 88% following a 500 krad dose. At these loss rates, approximately 5 Mrad of electron beam irradiation is required to reduce concentrations from 100 g/l to drinking water quality (5 μg/l). Since many waste streams are also inhabited by bacterial populations which may affect filtering operations, the effect of irradiation on those populations was also studied. 60Co and electron beam irradiation were both lethal to the bacteria studied at irradiation levels far lower than were necessary to remove organic contaminants

  13. Radiation induced graft copolymerization of cellulosic fabric waste and its application in the removal of cyanide and dichromate from aqueous solution

    International Nuclear Information System (INIS)

    Graft polymerization and crosslinking in radiation processing are attractive techniques for modification of the chemical and physical properties of the conventional polymers. The graft polymerization and subsequent chemical treatment can introduce a chelate agent function into a conventional polymer such as cellulosic fabric. Cellulosic graft copolymers were prepared by the reaction of the fiber with acrylonitrile (AN) and 2-acrylamido-2-methyl propane sulfonic acid (AMPS) in DMF initiated by gamma-radiation 60Co. The grafted fabric was chemically treated with hydroxyl amine to obtain amidoxime form. Factors affecting on the grafting such as radiation dose, monomer concentration and solvent concentration as well as monomer composition was investigated. The chemically modified graft fabric was applied for recovery of cyanide and dichromate from aqueous solution. The CN show removal percent 89%, whereas dichromate has 65% removal percent

  14. BERYLLIUM MEASUREMENT IN COMMERCIALLY AVAILABLE WET WIPES

    Energy Technology Data Exchange (ETDEWEB)

    Youmans-Mcdonald, L.

    2011-02-18

    Analysis for beryllium by fluorescence is now an established method which is used in many government-run laboratories and commercial facilities. This study investigates the use of this technique using commercially available wet wipes. The fluorescence method is widely documented and has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The procedure involves dissolution of samples in aqueous ammonium bifluoride solution and then adding a small aliquot to a basic hydroxybenzoquinoline sulfonate fluorescent dye (Berylliant{trademark} Inc. Detection Solution Part No. CH-2) , and measuring the fluorescence. This method is specific to beryllium. This work explores the use of three different commercial wipes spiked with beryllium, as beryllium acetate or as beryllium oxide and subsequent analysis by optical fluorescence. The effect of possible interfering metals such as Fe, Ti and Pu in the wipe medium is also examined.

  15. Process of forming catalytic surfaces for wet oxidation reactions

    Science.gov (United States)

    Jagow, R. B. (Inventor)

    1977-01-01

    A wet oxidation process was developed for oxidizing waste materials, comprising dissolved ruthenium salt in a reactant feed stream containing the waste materials. The feed stream is introduced into a reactor, and the reactor contents are then raised to an elevated temperature to effect deposition of a catalytic surface of ruthenium black on the interior walls of the reactor. The feed stream is then maintained in the reactor for a period of time sufficient to effect at least partial oxidation of the waste materials.

  16. Development studies of a novel wet oxidation process

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, T.W.; Dhooge, P.M. [Delphi Research, Inc., Albuquerque, NM (United States)

    1995-10-01

    Many DOE waste streams and remediates contain complex and variable mixtures of organic compounds, toxic metals, and radionuclides. These materials are often dispersed in organic or inorganic matrices, such as personal protective equipment, various sludges, soils, and water. Incineration and similar combustive processes do not appear to be viable options for treatment of these waste streams due to various considerations. The objective of this project is to develop a novel catalytic wet oxidation process for the treatment of multi-component wastes. The DETOX process uses a unique combination of metal catalysts to increase the rate of oxidation of organic materials.

  17. Wetting front instability in an initially wet unsaturated fracture

    International Nuclear Information System (INIS)

    Experimental results exploring gravity-driven wetting front instability in a pre-wetted, rough-walled analog fracture are presented. Initial conditions considered include a uniform moisture field wetted to field capacity of the analog fracture and the structured moisture field created by unstable infiltration into an initially dry fracture. As in previous studies performed under dry initial conditions, instability was found to result both at the cessation of stable infiltration and at flux lower than the fracture capacity under gravitational driving force. Individual fingers were faster, narrower, longer, and more numerous than observed under dry initial conditions. Wetting fronts were found to follow existing wetted structure, providing a mechanism for rapid recharge and transport

  18. A Comparative Study of Chromium and Cadmium Removal from Their Common Aqueous Solution by Batch Operation Using Tea Factory Waste as Adsorbent

    Directory of Open Access Journals (Sweden)

    Jibesh Datta

    2014-06-01

    Full Text Available The process of adsorption is a powerful tool for the treatment of industrial wastewater. In the recent years many studies have been conducted to evaluate the effectiveness of various locally available economical adsorbents for the removal of various heavy metals from the waste water. In the present study tea factory waste is used as adsorbent and its capacity to remove toxic heavy metals chromium and cadmium from their combined solution is investigated. Batch adsorption study is conducted to find the adsorption capacity of the adsorbent and the effect of the three important process parameters, i.e. agitation rate, adsorbent dose and initial metal ion concentration is evaluated. The maximum adsorption capacity of 24.88 mg/g and 23.92 mg/g is observed in case of cadmium and chromium respectively. It is also found that the removal efficiency of cadmium is higher than that of chromium in all cases. The experimental results are also found to be well fitted in the Langmuir and Freundlich Isotherm model.

  19. 75 FR 35127 - Hazardous and Solid Waste Management System; Identification and Listing of Special Wastes...

    Science.gov (United States)

    2010-06-21

    ... movement), or wastes from wet air pollution control devices, often in addition to other solid wastes... guidelines regarding cosmetic effects (such as tooth or skin discoloration) or aesthetic effects (such...

  20. Flow of Aqueous Humor

    Science.gov (United States)

    ... Facebook Twitter Google Plus Email Print this page Flow of Aqueous Humor Most, but not all, forms ... aqueous humor) produced by the eye's ciliary body flows out freely (follow blue arrow). Aqueous humor flows ...

  1. Metal separations using aqueous biphasic partitioning systems

    International Nuclear Information System (INIS)

    Aqueous biphasic extraction (ABE) processes offer the potential for low-cost, highly selective separations. This countercurrent extraction technique involves selective partitioning of either dissolved solutes or ultrafine particulates between two immiscible aqueous phases. The extraction systems that the authors have studied are generated by combining an aqueous salt solution with an aqueous polymer solution. They have examined a wide range of applications for ABE, including the treatment of solid and liquid nuclear wastes, decontamination of soils, and processing of mineral ores. They have also conducted fundamental studies of solution microstructure using small angle neutron scattering (SANS). In this report they review the physicochemical fundamentals of aqueous biphase formation and discuss the development and scaleup of ABE processes for environmental remediation

  2. Analysis of corrosion products of carbon steel in wet bentonite

    International Nuclear Information System (INIS)

    As a part of evaluation of the long-term durability for the overpack containers for high-level radioactive waste, we have conducted corrosion tests for carbon steel in wet bentonite, a candidate buffer material. The corrosion rates were evaluated by weight difference of carbon steel and corrosion products were analyzed by Fourier transform infrared spectroscopy (FT-IR) and colorimetry. At 40degC, the corrosion rate of carbon steel in wet bentonite was smaller than that in pure water. At 95degC, however, the corrosion rate in wet bentonite was much higher than that in pure water. This high corrosion rate in wet bentonite at 95degC was considered to result from evaporation of moisture in bentonite in contact with the metal. This evaporation led to dryness and then to shrinkage of the bentonite, which generated ununiform contact of the metal with bentonite. Probably, this ununiform contact promoted the local corrosion. The locally corroded parts of specimen in wet bentonite at 95degC were analyzed by Fourier transform infrared microspectroscopy (micro-FT-IR), and lepidocrocite γ-FeO(OH) was found as well as goethite α-FeO(OH). In wet bentonite at 95degC, hematite α-Fe2O3 was identified by means of colorimetry. (author)

  3. Aqueous Pu(IV) sorption on brucite

    International Nuclear Information System (INIS)

    The sorption behavior of aqueous Pu(IV) on brucite (Mg(OH)2) in the presence and absence of citrate was investigated by a combination of wet chemical batch sorption experiments and X-ray photoelectron spectroscopy (XPS). Sorption occurs rapidly at near 100% levels from pH 8 to pH 13, and is not affected by the presence of citrate. XPS results indicate that Pu was incorporated in the subsurface in the cases studied. (orig.)

  4. An evaluation of radionuclide batch sorption data on Culebra dolomite for aqueous compositions relevant to the human intrusion scenario for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Transport models used for performance assessment of the Waste Isolation Pilot Plant (WIPP) in the event of human intrusion into the repository currently rely on the Kd linear sorption isotherm model to predict rates of radionuclide migration. The vast majority of Kd data was measured in static (batch) experiment on powdered substrate; most data specific to the Culebra dolomite were gathered in this way for five radioelements of concern using up to four different water compositions. This report summarizes the available data, examines inconsistencies between these data and the assumptions of the Kd model, and discusses potential difficulties in using existing sorption data for predictive modeling of radionuclide retardation through adsorption modeling are presented as an alternative to the Kd model

  5. Squeezing wetting and nonwetting liquids

    OpenAIRE

    Samoilov, V. N.; Persson, B. N. J.

    2004-01-01

    We present molecular-dynamics results for the squeezing of octane (C8H18) between two approaching solid elastic walls with different wetting properties. The interaction energy between the octane bead units and the solid walls is varied from a very small value (1 meV), corresponding to a nonwetting surface with a very large contact angle (nearly 180 degrees), to a high value (18.6 meV) corresponding to complete wetting. When at least one of the solid walls is wetted by octane we observe well d...

  6. Properties of radioactive wastes and waste containers

    International Nuclear Information System (INIS)

    This program is sponsored by the Nuclear Regulatory Commission to address basic concerns in assessing the performance of solidified radwaste. Experiments were initiated to address these concerns. In particular, leachability of solidified radwastes and the physical stability of the ensuing waste forms were evaluated. In addition, leaching experiments designed to address the effects of alternating wet/dry cycles and of varying the length of these cycles on the leach behavior of waste forms were initiated

  7. Wet blasting in conjunction with decommissioning

    International Nuclear Information System (INIS)

    -crystallization and through ion exchange. It may also be integrated into the oxide by filling vacancies present in the oxide. Activity is lower on cold system surfaces than on the hot surfaces because of the slower corrosion rate. The oxide layer is not as thick as on the hot system surfaces and the contamination has looser bonds to the oxide surface which makes it easier to decontaminate. One effective method to decontaminate components is wet blasting with glass beads or alumina oxide for a more effective peeling i.e., when decommissioning. When compared with the other main options available, high pressure cleaning, electro polishing and chemical bating, wet blasting provides comparable or better decontamination factors leaving a derived waste easier to handle and store. Wet blasting is compared to other methods a fast way to decontaminate components. When wet blasting the beads are surrounded with a film of water, so at the moment of impact against the components works like a pressure-absorbing cushion. This prevents the beads from being in direct contact with the metal surface. The oxides on the metal surface blows away by the pressure shock by the water-cushions around the beads. And in the aspect when it's time to decommission a plant where a huge systematic operation is needed, safety is important i.e. time exposed to active components. Wet blasting providing outer operator's position with proper radiation protection and more efficient blasting equipment results in a lesser dose taken by the operator. As mentioned oxides on cold system parts is easier to strip with wet blasting, while on hot system parts it's tougher and it could be profitable to first put the decontaminated parts in a electrolyte bath with i.e. Sodium sulfate solution (5% Na2SO4), to crack the oxide layer to easier remove it with wet blasting afterwards. Possible savings through wet blasting if equipment is used systematically in order to ensure that goods being sent for melting have an

  8. Removal of reactive dyes from aqueous solutions by a non-conventional and low cost agricultural waste: adsorption on ash of Aloe Vera plant

    Directory of Open Access Journals (Sweden)

    Mohammad Malakootian

    2014-08-01

    Full Text Available Dyes are an important class of pollutants and disposal of them in precious water resources must be avoided. Among various methods adsorption occupies a prominent place in dye removal. The aim of this study is to evaluate adsorption of dye Reactive Red 198 and Blue 19 (RR-198 & RB-19 (on to Aloe Vera plant ash from aqueous solutions. In this research Aloe Vera ash was prepared at laboratory conditions and then after shredding, screened by ASTM standard sieve with 60 -200 mesh sizes and the effects of pH (3-12, adsorbent dose (0.1-1 g/L, contact time (10-60 min, initial dye concentration (10-160 mg/L and temperature were investigated in the experiment. In different samples Dye concentration was measured by spectrophotometer at 592 nm and 520 nm wavelength for RR198 and RB19 respectively. Also the Langmuir and Freundlich adsorption isotherms were determined in order to describe the relations between the colored solutions and the adsorbent. The results of this study showed that acidic conditions were more conducive to enhance the hydrolysis rate than basic ones as the decomposition was optimum at pH 3. The adsorption rate of RR-198 and RB-19 dyes was increased by increasing of initial dye concentration, increasing of adsorbent dose in 0.1 to 0.4 mg/L. Dye solution was decolorized in a relatively short time (20 min. The efficiencies for RR-198 and RB- 19 reactive dyes were 82.68% and 90.42% respectively. The maximum adsorption capacity (qmax has been found to be 80.152 mg/g for RR-198 reactive dye and 88.452 mg/g for Blue 19 reactive dye. Adsorption isotherms were examined by Freundlich and Langmuir isotherm that finally showed the Freundlich multilayer isotherm has better accordance with dates. The results indicate that Aloe Vera ash plant as a natural and inexpensive adsorbent is a suitable adsorbent for the adsorption of textile dyes.

  9. Wet Gas Compressor Surge Detection

    OpenAIRE

    Jellum, Marie Rennemo

    2013-01-01

    The development of wet gas compressors for installation subsea is key to increase the recovery of oil and gas from the Norwegian Continental Shelf. Safe operation of the compressor depends on understanding of how wet gas affects the behavior of the machine. The compressor operating range is limited by stall and surge, and it is therefore particularly important to determine how liquid will affect the inception of these phenomena. Measuring pressure transients within the compressor or in the in...

  10. Subsea Wet Gas Compressor Dynamics

    OpenAIRE

    Perez Aguilera, Luber Carlui

    2013-01-01

    In this Thesis the Aspen HYSYS dynamic functionalities were explored in order to build a dynamic Wet Gas Compressor model. In particular the Automation feature was used to implement two different correction methods, interpolation and Wood?s correction, that accounts for wet gas impact on compression performance, in dynamic-state. This was done through the creation of a VBA script in Microsoft Excel. The implementation of the correction methods showed to be fast and effective.The HYSYS dynamic...

  11. Reentrant Wetting of Network Fluids

    Science.gov (United States)

    Bernardino, N. R.; Telo da Gama, M. M.

    2012-09-01

    We use a simple mesoscopic Landau-Safran theory of network fluids to show that a reentrant phase diagram, in the “empty liquid” regime, leads to nonmonotonic surface tension and reentrant wetting, as previously reported for binary mixtures. One of the wetting transitions is of the usual kind, but the low temperature transition may allow the display of the full range of fluctuation regimes predicted by renormalization group theory.

  12. Transport kinetics of wetting layers

    OpenAIRE

    Herminghaus, Stephan; Paatzsch, Thomas; Häcker, T.; Leiderer, Paul

    1995-01-01

    The transport kinetics of wetting layers of ethanol and propane on silver substrates is investigated by monitoring the temporal decay of pulsed-laser-induced spatial thickness modulations. Our method allows to distinguish between different transport mechanisms, such as direct exchange with the vapour phase, viscous flow within the wetting layer, or surface diffusion. In either ease, the activation energy found for the lateral transport points to viscous flow as the dominant mechanism in the i...

  13. Wetting film dynamics and stability

    OpenAIRE

    Radoev, B.; Stoeckelhuber, K. W.; Tsekov, R.; Letocart, P

    2011-01-01

    Although the wetting films are similar in many aspects to other thin liquid films, there are some differences in their behavior, too. In contrast to soap and emulsion films, whose surfaces are homogeneous, solid substrates of wetting films are heterogeneous as a rule, unless special measures for their homogenization are taken. Here we mean primarily heterogeneous distribution of surface energy leading to existence of hydrophobic domains on hydrophilic surfaces and vice versa. As is known, suc...

  14. Wetting of polymer covered surfaces

    OpenAIRE

    Halperin, A.; De Gennes, P.G.

    1986-01-01

    We consider solid surfaces, partly covered with flexible, neutral, linear polymers (by adsorption or by grafting), wetted by a liquid which is a good solvent of the poymer. We give formulae for the spreading coefficient S as a function of chain length, solvent quality and adsorption strength. We also discuss the wetting films obtained in spreading a droplet of (non volatile) solvent : the equilibrium thickness e of the film is a compromise between S (favouring thin films) and the coil entropi...

  15. Wet Gas Compression : Impeller Rig

    OpenAIRE

    Amundsen, Siren Carstens

    2009-01-01

    Wet gas compression technology is of great value to the oil and gas industry for boosting of unprocessed well stream and to reduce investment costs related to equipment and personnel. The growing interest in wet gas compression leads to a general request for accurate performance calculation procedures and proper measurement techniques for multiphase flow metering in compressors. An impeller rig for examination of single-phase and multiphase performance and aerodynamic stability is under con...

  16. Wet flue gas desulfurization processes

    OpenAIRE

    Hayrunnisa Çavuşoğlu; Mustafa Şahin Gülaboğlu

    2013-01-01

    The wet flue gas desulfurization process is widely used for the treatment of exhaust gases in power stations. Due to its high level of effectiveness over the already available processes, it has also been the mostly preferred method by industry. Its high SO2 removal efficiency, wide applicability of absorption chemicals and the ease of the chemical process handling which does not require comprehensive konowledge are among the main advantages of this process. In this article, various wet flue g...

  17. Wet and Dry Anaerobic Digestion of Biowaste and of Co-substrates

    OpenAIRE

    Li, Chaoran

    2015-01-01

    Treatment of municipal solid waste by anaerobic digestion can solve the environmental problems caused by this organic solid waste and also supply biogas as renewable energy for a sustainable development. In this study the improvement of wet anaerobic digestion by addition of co-substrates and the effect of moisture on dry anaerobic digestion were investigated.

  18. Use of agricultural waste sugar beet pulp for the removal of Gemazol turquoise blue-G reactive dye from aqueous solution

    International Nuclear Information System (INIS)

    The potential use of dried sugar beet pulp, an agricultural solid waste by-product, as an biosorbent for Gemazol turquoise blue-G, a copper-pthalocyanine reactive dye commonly used in dyeing of cotton, was investigated in the present study. Batch adsorption studies were carried out to examine the influence of various parameters such as initial pH, temperature and initial dye concentration. The results indicated that adsorption was strongly pH-dependent and slightly temperature-dependent. At 800 mg l-1 initial Gemazol turquoise blue-G concentration, dried sugar beet pulp exhibited the highest Gemazol turquoise blue-G uptake capacity of 234.8 mg g-1 at 25 deg. C and at an initial pH value of 2.0. The Freundlich, Langmuir, Redlich-Peterson and Langmuir-Freundlich, the two and three parameters adsorption models were used for the mathematical description of the biosorption equilibrium and isotherm constants were evaluated depending on temperature. Both the Langmuir and Redlich-Peterson models were applicable for describing the dye biosorption by dried sugar beet pulp in the concentration (100-800 mg l-1) and temperature (25-45 deg. C) ranges studied. Simple mass transfer and kinetic models were applied to the experimental data to examine the mechanisms of biosorption and potential rate controlling steps such as external mass transfer, intraparticle diffusion and biosorption process. The sorption process was found to be controlled by both surface and pore diffusion with surface diffusion at the earlier stages followed by pore diffusion at the later stages. Pseudo first-order, pseudo second-order and saturation type kinetic models described the biosorption kinetics accurately at all concentrations and temperatures studied. The thermodynamic analysis indicated that the sorption process was exothermic and the biosorption of dye on dried sugar beet pulp might be physical in nature

  19. Process for separating cesium ions from aqueous solutions

    International Nuclear Information System (INIS)

    A precipitation agent is added to the aqueous solution and the resulting precipitate containing Cs+ ions is separated from the solution. By this process, caesium is to be separated selectively compared with other alkaline metal ions with great efficiency from aqueous solutions, particularly aqueous MAW (medium activity waste). This is achieved by using a sodium tetraphenyl borate attracting electrons to the phenyl rings and having substitutes. (orig./PW)

  20. Study of wet blasting of components in nuclear power stations

    Energy Technology Data Exchange (ETDEWEB)

    Hall, J

    1999-12-01

    This report looks at the method of wet blasting radioactive components in nuclear power stations. The wet blaster uses pearl shaped glass beads with the dimensions of 150-250 {mu}m mixed with water as blasting media. The improved design, providing outer operator's positions with proper radiation protection and more efficient blasting equipment has resulted in a lesser dose taken by the operators. The main reason to decontaminate components in nuclear power plants is to enable service on these components. On components like valves, pump shafts, pipes etc. oxides form and bind radiation. These components are normally situated at some distance from the reactor core and will mainly suffer from radiation from so called activation products. When a component is to be decontaminated it can be decontaminated to a radioactive level where it will be declassified. This report has found levels ranging from 150-1000 Bq/kg allowing declassification of radioactive materials.This difference is found between different countries and different organisations. The report also looks at the levels of waste generated using wet blasting. This is done by tracking the contamination to determine where it collects. It is either collected in the water treatment plant or collected in the blasting media. At Barsebaeck the waste levels, from de-contaminating nearly 800 components in one year, results in a waste volume of about 0,250 m{sup 3}. This waste consists of low and medium level waste and will cost about 3 600 EURO to store. The conclusions of the report are that wet blasting is an indispensable way to treat contaminated components in modern nuclear power plants. The wet blasting equipment can be improved by using a robot enabling the operators to remotely treat components from the outer operator's positions. There they will benefit from better radiation protection thus further reduce their taken dose. The wet blasting equipment could also be used to better control the levels of

  1. Repeated bouncing of drops on wetting and non-wetting surfaces mediated by a persisting thin air film

    Science.gov (United States)

    de Ruiter, Jolet; Lagraauw, Rudy; van den Ende, Dirk; Mugele, Frieder

    2014-11-01

    Liquid drops impinging onto solid surfaces undergo a variety of impact scenarios such as splashing, sticking, and bouncing, depending on impact conditions and substrate properties. Bouncing requires efficient conversion of initial kinetic energy into surface energy and back into kinetic energy. This process is believed to be limited to non-wetting, in particular superhydrophobic surfaces, for which viscous dissipation during drop-substrate contact is minimal. Here, we report a novel bouncing mechanism that applies equally to non-wetting and wetting systems for flat surfaces with contact angles down to 10 degrees. For initial impact speeds up to about 0.5 m/s we demonstrate using dual wavelength interferometry that aqueous and non-aqueous drops remain separated from the substrate by air films of (sub)micrometer thickness at all times throughout a series of up to 16 consecutive bouncing events. We show that the purely dissipative force arising from the viscous squeeze-out of air is responsible for both the momentum transfer and for a substantial part of the residual energy dissipation.

  2. Heavy metals determinations in dry and wet meteoric deposition

    International Nuclear Information System (INIS)

    Acid rain is now widely studied by analyzing the parameters that characterize it. As the latest researches demonstrate, it is possible to further understanding of meteoric deposition (i.e. bulk, wet and dry) by the metering of such micropollutants as heavy metals. These are released into the atmosphere as by-products of household heating fuels and industrial wastes. This paper seeks to provide an assessment of certain heavy metals present in meteoric samples and link their presence to the actual state of the environment in which they were detected. Samples of bulk and wet depositions were collected weekly and those of dry deposition monthly so as to achieve a uniform and representative quantity of the latter for subsequent determination. Both the wet and dry samples were collected from the center and outskirts of a large urban community, whereas only wet samples were also collected in the vicinity of a power plant. The wet samples were treated with HNO3 up to pH 1.8 and analyzed by atomic absorption in a Perkin-Elmer 4000 graphite furnace. The elements analyzed were Ni, V, Cd, As, Zn, Cr, Se, Pb. The dry samples were homogenized in an agate mortar and analyzed by high resolution neutron activation gamma spectrometry. Radiation time and flow of the Triga Mark II reactor varied depending on isotope, i.e. whether long, medium or short life. The heavy metals analyzed were Fe, Ni, V, Zn, Cr, Co, As, Sb and some others

  3. Aqueous foam toxicology evaluation and hazard review

    Energy Technology Data Exchange (ETDEWEB)

    Archuleta, M.M.

    1995-10-01

    Aqueous foams are aggregates of bubbles mechanically generated by passing air or other gases through a net, screen, or other porous medium that is wetted by an aqueous solution of surface-active foaming agents (surfactants). Aqueous foams are important in modem fire-fighting technology, as well as for military uses for area denial and riot or crowd control. An aqueous foam is currently being developed and evaluated by Sandia National Laboratories (SNL) as a Less-Than-Lethal Weapon for the National Institute of Justice (NIJ). The purpose of this study is to evaluate the toxicity of the aqueous foam developed for the NIJ and to determine whether there are any significant adverse health effects associated with completely immersing individuals without protective equipment in the foam. The toxicity of the aqueous foam formulation developed for NIJ is determined by evaluating the toxicity of the individual components of the foam. The foam is made from a 2--5% solution of Steol CA-330 surfactant in water generated at expansion ratios ranging from 500:1 to 1000:1. SteoI CA-330 is a 35% ammonium laureth sulfate in water and is produced by Stepan Chemical Company and containing trace amounts (<0.1%) of 1,4-dioxane. The results of this study indicate that Steol CA-330 is a non-toxic, mildly irritating, surfactant that is used extensively in the cosmetics industry for hair care and bath products. Inhalation or dermal exposure to this material in aqueous foam is not expected to produce significant irritation or systemic toxicity to exposed individuals, even after prolonged exposure. The amount of 1,4-dioxane in the surfactant, and subsequently in the foam, is negligible and therefore, the toxicity associated with dioxane exposure is not significant. In general, immersion in similar aqueous foams has not resulted in acute, immediately life-threatening effects, or chronic, long-term, non-reversible effects following exposure.

  4. Precipitation of neptunium dioxide from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, K E

    1999-12-01

    Tens of thousands of metric tons of highly radioactive, nuclear waste have been generated in the US. Currently, there is no treatment or disposal facility for these wastes. Of the radioactive elements in high-level nuclear waste, neptunium (Np) is of particular concern because it has a long half-life and may potentially be very mobile in groundwaters associated with a proposed underground disposal site at Yucca Mountain, Nevada. Aqueous Np concentrations observed in previous, short-term solubility experiments led to calculated potential doses exceeding proposed long-term regulatory limits. However, thermodynamic data for Np at 25 C showed that these observed aqueous Np concentrations were supersaturated with respect to crystalline NpO{sub 2}. It was hypothesized that NpO{sub 2} is the thermodynamically stable solid phase in aqueous solution, but it is slow to form in an aqueous solution of NpO{sub 2}{sup +} on the time scale of previous experiments. The precipitation of NpO{sub 2} would provide significantly lower aqueous Np concentrations leading to calculated doses below proposed regulatory limits. To test this hypothesis, solubility experiments were performed at elevated temperature to accelerate any slow precipitation kinetics. Ionic NpO{sub 2}{sup +} (aq) was introduced into very dilute aqueous solutions of NaCl with initial pH values ranging from 6 to 10. The reaction vessels were placed in an oven and allowed to react at 200 C until steady-state aqueous Np concentrations were observed. In all cases, aqueous Np concentrations decreased significantly from the initial value of 10{sup {minus}4} M. The solids that formed were analyzed by x-ray powder diffraction, x-ray absorption spectroscopy, and scanning electron microscopy. The solids were determined to be high-purity crystals of NpO{sub 2}. This is the first time that crystalline NpO{sub 2} has been observed to precipitate from NpO{sub 2}{sup +}(aq) in near-neutral aqueous solutions. The results obtained

  5. Microwave assisted wet oxidation of p-nitrophenol

    Institute of Scientific and Technical Information of China (English)

    BO; Longli; CHEN; Shuo; QUAN; Xie; LIU; Xitao; ZHAO; Huimin

    2005-01-01

    Aqueous solution of p-nitrophenol (PNP) was treated continuously by microwave assisted wet oxidation while flowing through a granular activated carbon (GAC) fixed bed. PNP was pre-adsorbed onto GAC prior to being put into the reactor so as to prevent PNP adsorption on GAC during microwave irradiation. PNP solutions with different initial concentration (218.6 mg/L and 1200 mg/L) were treated under conditions of microwave power 500 W, liquid flow 6.4 mL/min and air flow 40 mL/min or 60 mL/min. The results indicated that the removal of PNP was higher than 90% and more than 65% PNP was mineralized. Phenol, nitrobenzene, hydroquinone and benzoquinone occurred as course products during the operation process, which were degraded further. The biodegradability of the outflow was improved greatly by microwave assisted wet oxidation.

  6. Modeling Non-aqueous Phase Liquid Displacement Process

    Institute of Scientific and Technical Information of China (English)

    Yang Zhenqing; Shao Changjin; Zhou Guanggang; Qiu Chao

    2007-01-01

    A pore-network model physically based on pore level multiphase flow was used to study the water-non-aqueous phase liquid (NAPL) displacement process, especially the effects of wettability, water-NAPL interfacial tension, the fraction of NAPL-wet pores, and initial water saturation on the displacement. The computed data show that with the wettability of the mineral surfaces changing from strongly water-wet to NAPL-wet, capillary pressure and the NAPL relative permeability gradually decrease, while water-NAPL interfacial tension has little effect on water relative permeability, but initial water saturation has a strong effect on water and NAPL relative permeabilities. The analytical results may help to understand the micro-structure displacement process of non-aqueous phase liquid and to provide the theoretical basis for controlling NAPL migration.

  7. Squeezing wetting and nonwetting liquids.

    Science.gov (United States)

    Samoilov, V N; Persson, B N J

    2004-01-22

    We present molecular-dynamics results for the squeezing of octane (C8H18) between two approaching solid elastic walls with different wetting properties. The interaction energy between the octane bead units and the solid walls is varied from a very small value (1 meV), corresponding to a nonwetting surface with a very large contact angle (nearly 180 degrees), to a high value (18.6 meV) corresponding to complete wetting. When at least one of the solid walls is wetted by octane we observe well defined molecular layers develop in the lubricant film when the thickness of the film is of the order of a few atomic diameters. An external squeezing-pressure induces discontinuous, thermally activated changes in the number n of lubricant layers (n-->n-1 layering transitions). With increasing interaction energy between the octane bead units and the solid walls, the transitions from n to n-1 layers occur at higher average pressure. This results from the increasing activation barrier to nucleate the squeeze-out with increasing lubricant-wall binding energy (per unit surface area) in the contact zone. Thus, strongly wetting lubricant fluids are better boundary lubricants than the less wetting ones, and this should result in less wear. We analyze in detail the effect of capillary bridge formation (in the wetting case) and droplets formation (in the nonwetting case) on the forces exerted by the lubricant on the walls. For the latter case small liquid droplets may be trapped at the interface, resulting in a repulsive force between the walls during squeezing, until the solid walls come into direct contact, where the wall-wall interaction may be initially attractive. This effect is made use of in some practical applications, and we give one illustration involving conditioners for hair care application. PMID:15268334

  8. Process for recovering uranium from wet process phosphoric acid (III)

    International Nuclear Information System (INIS)

    Uranium is conventionally recovered from wet-process phosphoric acid by two liquid ion exchange steps using a mixture of mono- and disubstituted phenyl esters of orthophosphoric acid (OPPA). Efficiency of the process drops as the mono-OPPA is lost preferentially to the aqueous phase. This invention provides a process for the removal of the uranium process organics (OPPA and organic solvents) from the raffinate of the first liquid ion exchange step and their return to the circuit. The process organics are removed by a combination flotation and absorption step, which results in the recovery of the organics on beads of a hydrophobic styrene polymer

  9. Recovery of uranium from wet-process phosphoric acid

    International Nuclear Information System (INIS)

    Uranium values are recovered as uranyl peroxide from wet process phosphoric acid by a solvent extraction-precipitation process. The preferred form of this process comprises a first solvent extraction with depa-topo followed by reductive stripping of the extractant with fe++ - containing phosphoric acid. After reoxidation, the uranium-containing aqueous stripping solution is extracted again with depa-topo and the pregnant organic is then stripped with a dilute ammonium carbonate solution. The resulting ammonium uranyl tricarbonate solution is then acidified, with special kerosene treatment to prevent wax formation, and the acidified solution is reacted with H2O2 to precipitate a uranyl peroxide compound

  10. Wet flue gas desulfurization processes

    Directory of Open Access Journals (Sweden)

    Hayrunnisa Çavuşoğlu

    2013-04-01

    Full Text Available The wet flue gas desulfurization process is widely used for the treatment of exhaust gases in power stations. Due to its high level of effectiveness over the already available processes, it has also been the mostly preferred method by industry. Its high SO2 removal efficiency, wide applicability of absorption chemicals and the ease of the chemical process handling which does not require comprehensive konowledge are among the main advantages of this process. In this article, various wet flue gas desulfurization processes such as lime/limestone have beendiscussed.

  11. Rheological Modifiers and Wetting Agents

    International Nuclear Information System (INIS)

    DOE tank waste treatment plants, the Waste Treatment Plant (WTP) at Hanford and Defense Waste Processing Facility (DWPF) at Savannah River, are designed to vitrify radioactive waste slurries for long-term storage. Plant throughput is currently limited by the waste solids loading. To increase waste throughput rates in the plant, an increase in the slurry solids concentration (or conversely, a reduction in the mass fraction of water in the waste) is being considered. However, the present mechanical designs used to mix and transport theses slurries are limited by the rheological properties. This reduction of water results in an increase in rheological properties that challenge plant design and performance. To support this increase in throughput, there is a need to reduce the rheological properties of these waste slurries. The objective of this project is to determine a small set of well-performing and commercially available rheological modifiers that allow control rheological properties of various simulated and actual waste slurries and to understand the physical mechanisms that govern modification of waste rheology. It is estimated that processing at a higher solids concentration will reduce the operating life of these plants by one year for both facilities, representing roughly $1B in lifecycle cost savings. In addition, this research is potentially important to sustainable operations of both WTP and DWPF

  12. Rheological Modifiers and Wetting Agents

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Jaehun; Hansen, Erich; Berg, John C.

    2009-10-01

    DOE tank waste treatment plants, the Waste Treatment Plant (WTP) at Hanford and Defense Waste Processing Facility (DWPF) at Savannah River, are designed to vitrify radioactive waste slurries for long-term storage. Plant throughput is currently limited by the waste solids loading. To increase waste throughput rates in the plant, an increase in the slurry solids concentration (or conversely, a reduction in the mass fraction of water in the waste) is being considered. However, the present mechanical designs used to mix and transport theses slurries are limited by the rheological properties. This reduction of water results in an increase in rheological properties that challenge plant design and performance. To support this increase in throughput, there is a need to reduce the rheological properties of these waste slurries. The objective of this project is to determine a small set of well-performing and commercially available rheological modifiers that allow control rheological properties of various simulated and actual waste slurries and to understand the physical mechanisms that govern modification of waste rheology. It is estimated that processing at a higher solids concentration will reduce the operating life of these plants by one year for both facilities, representing roughly $1B in lifecycle cost savings. In addition, this research is potentially important to sustainable operations of both WTP and DWPF

  13. Charged hydrophobic colloids at an oil-aqueous phase interface

    Science.gov (United States)

    Kelleher, Colm P.; Wang, Anna; Guerrero-García, Guillermo Iván; Hollingsworth, Andrew D.; Guerra, Rodrigo E.; Krishnatreya, Bhaskar Jyoti; Grier, David G.; Manoharan, Vinothan N.; Chaikin, Paul M.

    2015-12-01

    Hydrophobic poly(methyl methacrylate) (PMMA) colloidal particles, when dispersed in oil with a relatively high dielectric constant, can become highly charged. In the presence of an interface with a conducting aqueous phase, image-charge effects lead to strong binding of colloidal particles to the interface, even though the particles are wetted very little by the aqueous phase. We study both the behavior of individual colloidal particles as they approach the interface and the interactions between particles that are already interfacially bound. We demonstrate that using particles which are minimally wetted by the aqueous phase allows us to isolate and study those interactions which are due solely to charging of the particle surface in oil. Finally, we show that these interactions can be understood by a simple image-charge model in which the particle charge q is the sole fitting parameter.

  14. Proefproject aandachtstoffen Wet milieugevaarlijke stoffen

    OpenAIRE

    Poel P van der; Ros JPM

    1988-01-01

    Dit rapport behandelt de uitvoering van het proefproject aandachtstoffen en geeft aanbevelingen aan het DGM voor vervolgonderzoek. De aandachtstoffenlijst wordt krachtens art. 22 Wet milieugevaarlijke stoffen vastgesteld en minstens eenmaal per jaar herzien, terwijl regelmatig onderzoek uitgevoerd moet worden naar stoffen die op deze lijst voorkomen. Voor het beschreven proefproject werden schriftelijke enquetes uitgevoerd voor vertegenwoordigers uit de categorieen kleurstoffen (trypan blue),...

  15. Inhibiting Wet Oxidation of Ammonia

    Science.gov (United States)

    Onisko, D. B. L.

    1985-01-01

    Simple modification of wet-oxidation process for treating organicwaste reduces loss of fixed nitrogen, potentially valuable byproduct of process. Addition of sufficient sulfuric acid to maintain reaction pH below 3 greatly reduces oxidation of ammonia to free nitrogen. No equipment modification required.

  16. Does Surface Roughness Amplify Wetting?

    Czech Academy of Sciences Publication Activity Database

    Malijevský, Alexandr

    2014-01-01

    Roč. 141, č. 18 (2014), s. 184703. ISSN 0021-9606 R&D Projects: GA ČR GA13-09914S Institutional support: RVO:67985858 Keywords : density functional theory * wetting * roughness Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.952, year: 2014

  17. Wetting of bituminized ion-exchangers under simulated repository conditions

    International Nuclear Information System (INIS)

    According to the present plans the spent nuclear fuel from four Finnish nuclear power units will be transferred after interim storage to the final disposal site where it will be encapsulated and disposed of in a final repository constructed into the bedrock at a depth of 500 meters. Low and medium level waste generated at nuclear power plants will be finally disposed of in caverns constructed in the bedrock at the power plant site. The safety of the final disposal is based on a multibarrier concept and the degree of safety is estimated by using predictive models. The properties of the waste form are taken into account in the design of the repository construction. Bitumen has been chosen as an immobilisation agent for the wet wastes at Olkiluoto Power Plant, where two BWR units, TVO 1 and TVO 2, have separate bituminization facilities designed by Asea-Atom. Properties of bituminized spent ion-exchange resins from Olkiluoto power plant have been studied by VTT Chemical Technology since the late 70's. These studies have concentrated mainly on determining the long-term behaviour of the bituminization product under the repository conditions. Current interest lies on wetted product as a diffusion barrier. For this purpose a microscopic method for the visualisation of the structure of the wetted product has been developed. The equilibration of the samples in simulated concrete groundwater is currently going on at a temperature of 5-8 deg. C. Preliminary results are presented in this paper. Diffusion experiments have been planned for the further characterising of the wetted product as a release barrier for radionuclides including modelling. (author)

  18. 40 CFR 227.30 - High-level radioactive waste.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false High-level radioactive waste. 227.30...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated waste...

  19. Treatment methods for radioactive mixed wastes in commercial low-level wastes: technical considerations

    International Nuclear Information System (INIS)

    Treatment options for the management of three generic categories of radioactive mixed waste in commercial low-level wastes (LLW) have been identified and evaluated. These wastes were characterized as part of a BNL study in which LLW generators were surveyed for information on potential chemical hazards in their wastes. The general treatment options available for mixed wastes are destruction, immobilization, and reclamation. Solidification, absorption, incineration, acid digestion, wet-air oxidation, distillation, liquid-liquid wastes. Containment, segregation, decontamination, and solidification or containment of residues, have been considered for lead metal wastes which have themselves been contaminated and are not used for purposes of waste disposal shielding, packaging, or containment. For chromium-containing wastes, solidification, incineration, wet-air oxidation, acid digestion, and containment have been considered. For each of these wastes, the management option evaluation has included an assessment of testing appropriate to determine the effect of the option on both the radiological and potential chemical hazards present

  20. WET SOLIDS FLOW ENHANCEMENT; FINAL

    International Nuclear Information System (INIS)

    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally

  1. 漂白废报纸脱墨浆AKD施胶过程的湿部化学环境分析%Wet Chemical Environment Analysis of Alkyl Ketene Dimmers (AKD) Sizing of Bleached Waste Newspaper Deinked Pulp

    Institute of Scientific and Technical Information of China (English)

    韦黎; 曹云峰; 熊林根

    2011-01-01

    An L9(34)orthogonal test was designed to study the effects of AKD (alkyl ketene dimmers) charge, CS (cationic starch) charge, PCC (precipitated calcium carbonate) charge and CPAM (cationic polyacrylamide) charge on AKD sizing of bleached waste newspaper deinked pulp. And the optimal conditions were as follows: AKD dosage 0.4%, CS dosage 0.6%, PCC dosage 5% and CPAM dosage 0.03%. The variation tendency of sizing performance was essentially consistent with the Zeta potential value and cationic demand of furnish. In sizing process, Zeta potential and cationic demand of pulp was also an important factor, which was influential in the AKD sizing performance.%对漂白废报纸脱墨浆AXeD(烷基烯酮二聚物)施胶过程中AKD用量、CS(阳离子淀粉)用量、PCC(沉淀碳酸钙)用量和CPAM(阳离子聚丙烯酰胺)用量进行四因素三水平方差分析,当AKD用量为0.2%~0.4%(质量分数),CS用量为0.6%~1.0%,PCC用量为5%~15%,CPAM用量为0.03%-0.09%时,AKD施胶较为适宜工艺条件为:AKD用量0.4%,CS用量0.6%,PCC用量5%,CPAM用量0.03%。对纸浆动电特性的研究表明,成纸的施胶度基本与纸浆中的Zeta电位、浆料溶解电荷需求量的变化趋势一致。在施胶过程中,控制Zeta电位、浆料溶解电荷需求量也是影响AKD施胶效果的重要因素。

  2. Goodbye, Waste! What We Make. Science and Technology Education in Philippine Society.

    Science.gov (United States)

    Philippines Univ., Quezon City. Science Education Center.

    This module: (1) discusses the need for disposing of waste safely; (2) provides information and activities on wet and dry wastes; and (3) shows how to prepare, maintain, and study a fertilizer basket (in which fertilizer is made from wet waste). Information on the biology of the basket (including role of bacteria and fungi in the decay process) is…

  3. Review of Wet Gas Compressor Performance

    OpenAIRE

    Rofiqi, Zaenuddin Ar

    2014-01-01

    Subsea wet gas compression without preliminary separation give an opportunity to develop mature and remote gas/condensate field. Predicting wet gas compressor performance is important to develop those fields. Currently there is no standard exist for wet gas compression performance calculation (Hundseid et al., 2008). The current standards (ISO 5389:2005) exist only for dry gas by utilizing Schultz method. In wet gas compression, fluid properties are changing as fluid being compressed. Schult...

  4. Closed Loop Waste Processing Dryer (DRYER) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this proposal is to develop a gravity-independent pasteurization and hot air drying process suitable for stabilization of ALS wet cabin waste,...

  5. Wetting hysteresis induced by nanodefects.

    Science.gov (United States)

    Giacomello, Alberto; Schimmele, Lothar; Dietrich, Siegfried

    2016-01-19

    Wetting of actual surfaces involves diverse hysteretic phenomena stemming from ever-present imperfections. Here, we clarify the origin of wetting hysteresis for a liquid front advancing or receding across an isolated defect of nanometric size. Various kinds of chemical and topographical nanodefects, which represent salient features of actual heterogeneous surfaces, are investigated. The most probable wetting path across surface heterogeneities is identified by combining, within an innovative approach, microscopic classical density functional theory and the string method devised for the study of rare events. The computed rugged free-energy landscape demonstrates that hysteresis emerges as a consequence of metastable pinning of the liquid front at the defects; the barriers for thermally activated defect crossing, the pinning force, and hysteresis are quantified and related to the geometry and chemistry of the defects allowing for the occurrence of nanoscopic effects. The main result of our calculations is that even weak nanoscale defects, which are difficult to characterize in generic microfluidic experiments, can be the source of a plethora of hysteretical phenomena, including the pinning of nanobubbles. PMID:26721395

  6. Erosion corrosion in wet steam

    International Nuclear Information System (INIS)

    The effect of different remedies against erosion corrosion in wet steam has been studied in Barsebaeck 1. Accessible steam systems were inspected in 1984, 1985 and 1986. The effect of hydrogen peroxide injection of the transport of corrosion products in the condensate and feed water systems has also been followed through chemical analyses. The most important results of the project are: - Low alloy chromium steels with a chromium content of 1-2% have shown excellent resistance to erosion corrosion in wet steam. - A thermally sprayed coating has shown good resistance to erosion corrosion in wet steam. In a few areas with restricted accessibility minor attacks have been found. A thermally sprayed aluminium oxide coating has given poor results. - Large areas in the moisture separator/reheater and in steam extraction no. 3 have been passivated by injection of 20 ppb hydrogen peroxide to the high pressure steam. In other inspected systems no significant effect was found. Measurements of the wall thickness in steam extraction no. 3 showed a reduced rate of attack. - The injection of 20 ppb hydrogen peroxide has not resulted in any significant reduction of the iron level result is contrary to that of earlier tests. An increase to 40 ppb resulted in a slight decrease of the iron level. - None of the feared disadvantages with hydrogen peroxide injection has been observed. The chromium and cobalt levels did not increase during the injection. Neither did the lifetime of the precoat condensate filters decrease. (author)

  7. Wet water glass production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

  8. Wet friction materials and lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Takayuki

    1988-02-01

    There are wet and dry friction materials used for friction clutches and friction brakes. Wet friction materials include sintered alloys and semimetallic substances. Paper friction materials which are the most common wet friction materials used in automobiles were studied for their performance and their relation to lubricants. All present paper friction materials are non-asbestos paper friction materials. The requirements for paper friction material performance are as follows: (1) The heat resistance and durability are so high that the material can stand sliding for a long time. (2) The friction curve is flat. (3) The mechanical strength, wear resistance, and resistance to oil pressure are high. (4) The coefficient of friction (particularly, of static friction) is very high. (5) Variations in the coefficient of friction with time are low. The friction characteristics and wear of paper friction materials are influenced by the lubricant used together with the paper friction materials. It is necessary to develop materials which are immune to the influence of the lubricant. (11 figs, 3 tabs, 21 refs)

  9. Integrated waste management - Looking beyond the solid waste horizon

    International Nuclear Information System (INIS)

    Waste as a management issue has been evident for over four millennia. Disposal of waste to the biosphere has given way to thinking about, and trying to implement, an integrated waste management approach. In 1996 the United Nations Environmental Programme (UNEP) defined 'integrated waste management' as 'a framework of reference for designing and implementing new waste management systems and for analysing and optimising existing systems'. In this paper the concept of integrated waste management as defined by UNEP is considered, along with the parameters that constitute integrated waste management. The examples used are put into four categories: (1) integration within a single medium (solid, aqueous or atmospheric wastes) by considering alternative waste management options (2) multi-media integration (solid, aqueous, atmospheric and energy wastes) by considering waste management options that can be applied to more than one medium (3) tools (regulatory, economic, voluntary and informational) and (4) agents (governmental bodies (local and national), businesses and the community). This evaluation allows guidelines for enhancing success: (1) as experience increases, it is possible to deal with a greater complexity; and (2) integrated waste management requires a holistic approach, which encompasses a life cycle understanding of products and services. This in turn requires different specialisms to be involved in the instigation and analysis of an integrated waste management system. Taken together these advance the path to sustainability

  10. A comparative structural study of wet and dried ettringite

    International Nuclear Information System (INIS)

    Two different techniques were used to compare structural characteristics of 'wet' ettringite (stored in the synthesis mother liquid) and 'dried' ettringite (dried to 35% relative humidity over saturated CaCl2 solution). Lattice parameters and the water content in the channel region of the structure (site occupancy factor of the water molecule not bonded to cations) as well as microstructure parameters (size and strain) were determined from a Rietveld refinement on synchrotron powder diffraction data. Local environment of sulphate anions and of the hydrogen bonding network was characterized by Raman spectroscopy. Both techniques led to the same conclusion: the 'wet' ettringite sample immersed in the mother solution from the synthesis presents similar structural features as ettringite dried to 35% relative humidity. An increase of the a lattice parameter combined with a decrease of the c lattice parameter occurs on drying. The amount of structural water, the point symmetry of sulphate and the hydrogen bond network are unchanged when passing from the wet to the dried ettringite powder. Ettringite does not form a high-hydrate polymorph in equilibrium with alkaline solution, in contrast to the AFm phases that lose water molecules on drying. According to these results we conclude that ettringite precipitated in aqueous solution at the early hydration stages is of the same chemical composition as ettringite present in the hardening concrete.

  11. A study of low-cost adsorbent materials for removing Cr(VI from aqueous waste effluent Estudio de materiales adsorbentes de bajo costo para remover Cr(VI de efluentes acuosos

    Directory of Open Access Journals (Sweden)

    Castillo Serna Elianna

    2011-05-01

    Full Text Available  

    The present paper shows very high potential for two types of solid (a commercial alumina and material obtained by composting, i.e. matured compost on Cr(VI adsorption/elimination in aqueous solution using a concentration range close to those previously detected in waste-water from Colombian industries. Both had important properties for eliminating Cr(VI, the compost being more important as it represents low-cost material. Optimal conditions for chromium adsorption on alumina and compost were established. Initial Cr(VI alumina concentration was 10 mgL-1, with 100 mL/g volume of solution per adsorbent mass, pH=2.0, 1 hour equilibrium time and 150 rpm stirring. For compost, initial Cr(VI concentration was = 3 mg L-1, 50 mL/g volume of solution per adsorbent mass, pH=2.5, 3 hour equilibrium time and 150 rpm stirring. The experiments showed that compost adsorption properties could be enhanced by adding small quantities of alumina. Compost could thus be chosen as a promising material for use in bioremediation chromium-containing waste water in a management programme for using solid waste in for minimising environmental impact.

     

     

    Continuous environmental monitoring for aqueous effluents

    Energy Technology Data Exchange (ETDEWEB)

    Pitt, Jr., W. W.; Jones, G. Jr.

    1980-05-01

    An aquatic environmental monitor has been developed that will continuously monitor aqueous waste streams from coal processing plants. The monitor contains three different instruments: a continuous chemical oxygen demand monitor and two continuous-flow fluorometers with different excitation-emission characteristics. A prototype instrument was fabricated and evaluated for several different applications. The details of the instrument design and results of its evaluation are presented in this report.

  12. Precursor films in wetting phenomena

    OpenAIRE

    Popescu, M. N.; Oshanin, G.; Dietrich, S.; Cazabat, A. -M.

    2012-01-01

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in t...

  13. Combined wet oxidation and alkaline hydrolysis of polyvinylchloride

    DEFF Research Database (Denmark)

    Sørensen, E.; Bjerre, A.B.

    1992-01-01

    In view of the widespread aversion to burning polyvinylchloride (PVC) together with municipal waste, we have attempted an alternative approach to its decomposition. This paper describes a combined wet oxidation/alkaline hydrolysis yielding water soluble, biodegradable products. Experiments were...... carried out at temperatures from 180-260 degree C and reaction times of 8-24 min. The chloride liberated provides information on the rate constants. Considering the measured Cl- and Chemical Oxygen Demand (COD) values, we find hydrolysis and oxidation processes to be interdependent. The main products are...

  14. Development studies for a novel wet oxidation process. Phase 2

    International Nuclear Information System (INIS)

    DETOXSM is a catalyzed wet oxidation process which destroys organic materials in an acidic water solution of iron at 373 to 473 K. The solution can be used repeatedly to destroy great amounts of organic materials. Since the process is conducted in a contained vessel, air emissions from the process can be well controlled. The solution is also capable of dissolving and concentrating many heavy and radioactive metals for eventual stabilization and disposal. The Phase 2 effort for this project is site selection and engineering design for a DETOX demonstration unit. Site selection was made using a set of site selection criteria and evaluation factors. A survey of mixed wastes at DOE sites was conducted using the Interim Mixed Waste Inventory Report. Sites with likely suitable waste types were identified. Potential demonstration sites were ranked based on waste types, interest, regulatory needs, scheduling, ability to provide support, and available facilities. Engineering design for the demonstration unit is in progress and is being performed by Jacobs Applied Technology. The engineering design proceeded through preliminary process flow diagrams (PFDs), calculation of mass and energy balances for representative waste types, process and instrumentation diagrams (P and IDs), preparation of component specifications, and a firm cost estimate for fabrication of the demonstration unit

  15. A Hybrid Dry and Aqueous Fractionation Method to Obtain Protein-Rich Fractions from Quinoa (Chenopodium quinoa Willd)

    OpenAIRE

    Avila Ruiz, Geraldine; Arts, Anke; Minor, Marcel; Schutyser, Maarten

    2016-01-01

    Combination of dry and aqueous fractionation is investigated to obtain protein-rich fractions from quinoa in a milder and more sustainable way compared to conventional wet fractionation. Dry fractionation of quinoa involved milling and subsequent air classification, generating a protein-enriched embryo fraction. Subsequently, this fraction was milled, suspended, and further fractionated by aqueous phase separation. The efficiency of aqueous phase separation could be improved by addition of Na...

  16. Encapsulation of nuclear wastes

    International Nuclear Information System (INIS)

    Intermediate-level radioactive wastes produced in the day-to-day operation of a nuclear power plant may be incorporated into a thermosettable resin by mixing aqueous wastes with a vinyl ester resin, an unsaturated polyester resin, or a mixture of the two, and curing the resulting water-in-oil emulsion at temperatures below 1000C. The wastes may be either solutions or suspensions of inorganic or organic compounds derived from evaporation, flocculation, coagulation, filtration, ion exchange, or other treatment processes. (LL)

  17. Modifications of oxidized Zircaloy-4 surface in contact with radiolysed wet air

    Energy Technology Data Exchange (ETDEWEB)

    Guipponi, C. [Universite de Lyon, Institut de Physique Nucleaire de Lyon, Universite Claude Bernard Lyon 1, CNRS UMR5822, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Millard-Pinard, N., E-mail: millard@ipnl.in2p3.fr [Universite de Lyon, Institut de Physique Nucleaire de Lyon, Universite Claude Bernard Lyon 1, CNRS UMR5822, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Bererd, N. [Universite de Lyon, Institut de Physique Nucleaire de Lyon, Universite Claude Bernard Lyon 1, CNRS UMR5822, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Universite de Lyon, UCBL-IUT Lyon 1, departement chimie, 43 Bd du 11 novembre 1918, F-69622 Villeurbanne Cedex (France); Serris, E.; Pijolat, M.; Peres, V. [Ecole Nationale Superieure des Mines de Saint Etienne, Centre SPIN, CNRS UMR5148, 158 cours Fauriel, 42 033 Saint Etienne Cedex (France); Wasselin-Trupin, V. [Institut de Radioprotection et de Surete Nucleaire, BP. 17, 92 262 Fontenay aux Roses (France)

    2012-02-01

    In the framework of radioactive waste geological disposal, the long term evolution of the nuclear wastes packages and the release of the radionuclides from the wastes have to be studied. Regarding compacted wastes (cladding tubes) coming from reprocessing of spent fuel, the Zircaloy-4 (zirconium alloy) cladding tubes have been activated and oxidized in reactors. In the disposal, the radioactive waste is exposed to humid air in a first phase and to water after the resaturation phase. In order to better assess the degradation process of these nuclear waste package, the influence of wet air proton radiolysis on the behavior of surface oxidized Zircaloy-4 has been investigated. Radiolysis experiments were performed using an irradiation cell which is associated to an extracted beam. Samples are exposed to wet air, under and without radiolysis, during 12 and 24 h. The water partial pressure has been fixed at 6 and 50 mbar in order to have, respectively, localized adsorbed water molecules and a thin film of adsorbed water. Before and after each treatment, sample surfaces were characterized by X-ray Photoelectron Spectroscopy (XPS) in order to identify the elements at the topmost surface of the solid. The wet air radiolysis causes changes at the surface of oxidized Zircaloy-4 and influences the corrosion phenomenon. Indeed, an enrichment of tin and the presence of nitrogen species were observed. It could be due to the formation of tritin(II) tetrahydroxide dinitrate and a Zr{sup 4+} tetramer on the topmost oxide surface.

  18. 废弃绿茶对水溶液中Co2+的吸附研究%Adsorption of Co2+ from aqueous solutions by waste green tea

    Institute of Scientific and Technical Information of China (English)

    董娴; 连慧亮; 耿世彬

    2012-01-01

    利用废弃绿茶叶粉末(简称茶叶末)作为吸附剂,考察了pH、温度、时间等对水溶液中Co2+的影响.结果表明:(1)茶叶末对Co2+的吸附量随着pH的上升而上升,其中pH=5.50为最佳.茶叶末对Co2+的吸附量均随时间延长呈现上升趋势,吸附速度先快后慢,吸附最佳时间为90min.(2)不同湿度下,茶叶末对Co2+的吸附较好地符合Langmuir模型.该吸附过程是化学离子交换过程,主要发生在重金属离子与羟基、氨基的氢原于之间.(3)茶叶末对Co2+的吸附是自发、放热过程,降温有利于吸附,反应时吸附界面上的混乱度增加.(4)盐酸是很好的解吸介质,解吸率为92.65%.通过灼烧(或燃烧)可以回收水溶液中绝大部分的Co2+,不仅减小了对环境的污染,而且节约了资源.%Waste green tea powder was used as adsorbent to remove the Co2+ from aqueous solutions. The effect of pH, contact time.Co2+ concentration and reaction temperature on adsorption efficiency was investigated. Experimental results showed that the Co2+ adsorption quantity was increased with increasing the pH and contacting time, the optimal pH and contacting time was 5. 50 and 90 min respectively. The adsorption rate appeared first quick back slow trend. The Co2+ adsorption process under different temperature could be well fitted by Langmuir model. The mechanism of adsorption was chemical ion-exchange, mainly happened between heavy metal ions and hydroxyl, amino and hydrogen atoms. The adsorption processes was spontaneous and exothermic; decreasing the temperature was benefit for Co2+ adsorption, the chaos of adsorption interface was increased during the adsorption process. Hydrochloric acid was a perfect desorption medium, the desorption rate of Co2+ in hydrochloric acid was 92. 65%. It was feasible to recover Co2+ from solution by incineration method, which could eliminate the Co2+ pollution to environment and save resources.

  19. Elucidating the mysteries of wetting.

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Edmund Blackburn, III (,; ); Bourdon, Christopher Jay; Grillet, Anne Mary; Sackinger, Philip A.; Grest, Gary Stephen; Emerson, John Allen; Ash, Benjamin Jesse; Heine, David R.; Brooks, Carlton, F.; Gorby, Allen D.

    2005-11-01

    Nearly every manufacturing and many technologies central to Sandia's business involve physical processes controlled by interfacial wetting. Interfacial forces, e.g. conjoining/disjoining pressure, electrostatics, and capillary condensation, are ubiquitous and can surpass and even dominate bulk inertial or viscous effects on a continuum level. Moreover, the statics and dynamics of three-phase contact lines exhibit a wide range of complex behavior, such as contact angle hysteresis due to surface roughness, surface reaction, or compositional heterogeneities. These thermodynamically and kinetically driven interactions are essential to the development of new materials and processes. A detailed understanding was developed for the factors controlling wettability in multicomponent systems from computational modeling tools, and experimental diagnostics for systems, and processes dominated by interfacial effects. Wettability probed by dynamic advancing and receding contact angle measurements, ellipsometry, and direct determination of the capillary and disjoining forces. Molecular scale experiments determined the relationships between the fundamental interactions between molecular species and with the substrate. Atomistic simulations studied the equilibrium concentration profiles near the solid and vapor interfaces and tested the basic assumptions used in the continuum approaches. These simulations provide guidance in developing constitutive equations, which more accurately take into account the effects of surface induced phase separation and concentration gradients near the three-phase contact line. The development of these accurate models for dynamic multicomponent wetting allows improvement in science based engineering of manufacturing processes previously developed through costly trial and error by varying material formulation and geometry modification.

  1. Toluene removal by oxidation reaction in spray wet scrubber: experimental, modeling and optimization

    Directory of Open Access Journals (Sweden)

    Roumporn Nikom

    2006-11-01

    Full Text Available Toluene, an important volatile organic compound (VOC, is used in many kinds of industries, such as painting, printing, coating, and petrochemical industries. The emission of toluene causes serious air pollution, odor problem, flammability problem and affects human health. This paper proposes the removal of toluene from waste air using a spray wet scrubber combining the absorption and oxidation reaction. Aqueous sodium hypochlorite (NaOCl solution was used as the scrubbing liquid in the system. NaOCl, the strongest oxidative agent, presents an effective toluene removal. As the scrubbed toluene is reacted, recirculation of the scrubbing liquid could be operated with a constant removal efficiency throughout the operting time. The investigated variables affecting the removal efficiency were air flow rate, inlet toluene concentration, NaOCl concentration, scrubbing liquid flow rate and size of spray nozzle. Influence of the scrubbing parameters was experimentally studied to develop a mathematical model of the toluene removal efficiency. The removal model reveals that the increase of scrubbing liquid flow rate, toluene concentration, and NaOCl concentration together with the decrease of air flow rate and size of spray nozzle can increase the toluene removal efficiency. Optimization problem with an objective function and constraints was set to provide the maximum toluene removal efficiency and solved by Matlab optimization toolbox. The optimization constraints were formed from the mathematical model and process limitation. The solution of the optimization was an air flow rate of 100 m3/h, toluene concentration of 1500 ppm, NaOCl concentration of 0.02 mol/l, NaOCl solution feed rate of 0.8 m3/h, and spray nozzle size of 0.5 mm. Solution of the optimization gave the highest toluene removal efficiency of 91.7%.

  2. Bubble Meets Droplet: Particle-Assisted Reconfiguration of Wetting Morphologies in Colloidal Multiphase Systems.

    Science.gov (United States)

    Zhang, Yi; Shitta, Abiola; Meredith, J Carson; Behrens, Sven H

    2016-06-01

    Wetting phenomena are ubiquitous in nature and play key functions in various industrial processes and products. When a gas bubble encounters an oil droplet in an aqueous medium, it can experience either partial wetting or complete engulfment by the oil. Each of these morphologies can have practical benefits, and controlling the morphology is desirable for applications ranging from particle synthesis to oil recovery and gas flotation. It is known that the wetting of two fluids within a fluid medium depends on the balance of interfacial tensions and can thus be modified with surfactant additives. It is reported that colloidal particles, too, can be used to promote both wetting and dewetting in multifluid systems. This study demonstrates the surfactant-free tuning and dynamic reconfiguration of bubble-droplet morphologies with the help of cellulosic particles. It further shows that the effect can be attributed to particle adsorption at the fluid interfaces, which can be probed by interfacial tensiometry, making particle-induced transitions in the wetting morphology predictable. Finally, particle adsorption at different rates to air-water and oil-water interfaces can even lead to slow, reentrant wetting behavior not familiar from particle-free systems. PMID:27167839

  3. Development of wet-dry reversible reverse osmosis membrane with high performance from cellulose acetate and cellulose triactate blend

    NARCIS (Netherlands)

    Vasarhelyi, K.; Ronner, J.A.; Mulder, M.H.V.; Smolders, C.A.

    1987-01-01

    Wet-dry reversible membrane were prepared bt a two-step coagulation procedure. A cast film containing a blend of cellulose triacetate as polymers, dioxane and acetone as solvents and maleic acid and methanol as additives was immersed consecutively in two aqueous coagulation baths, the first bath bei

  4. Liquid secondary waste. Waste form formulation and qualification

    Energy Technology Data Exchange (ETDEWEB)

    Cozzi, A. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Dixon, K. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hill, K. A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); King, W. D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nichols, R. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    The Hanford Site Effluent Treatment Facility (ETF) currently treats aqueous waste streams generated during Site cleanup activities. When the Hanford Tank Waste Treatment and Immobilization Plant (WTP) begins operations, a liquid secondary waste (LSW) stream from the WTP will need to be treated. The volume of effluent for treatment at the ETF will increase significantly. Washington River Protection Solutions is implementing a Secondary Liquid Waste Immobilization Technology Development Plan to address the technology needs for a waste form and solidification process to treat the increased volume of waste planned for disposal at the Integrated Disposal Facility IDF). Waste form testing to support this plan is composed of work in the near term to demonstrate the waste form will provide data as input to a performance assessment (PA) for Hanford’s IDF.

  5. Liquid secondary waste. Waste form formulation and qualification

    International Nuclear Information System (INIS)

    The Hanford Site Effluent Treatment Facility (ETF) currently treats aqueous waste streams generated during Site cleanup activities. When the Hanford Tank Waste Treatment and Immobilization Plant (WTP) begins operations, a liquid secondary waste (LSW) stream from the WTP will need to be treated. The volume of effluent for treatment at the ETF will increase significantly. Washington River Protection Solutions is implementing a Secondary Liquid Waste Immobilization Technology Development Plan to address the technology needs for a waste form and solidification process to treat the increased volume of waste planned for disposal at the Integrated Disposal Facility IDF). Waste form testing to support this plan is composed of work in the near term to demonstrate the waste form will provide data as input to a performance assessment (PA) for Hanford's IDF.

  6. Mixed waste characterization reference document

    International Nuclear Information System (INIS)

    Waste characterization and monitoring are major activities in the management of waste from generation through storage and treatment to disposal. Adequate waste characterization is necessary to ensure safe storage, selection of appropriate and effective treatment, and adherence to disposal standards. For some wastes characterization objectives can be difficult and costly to achieve. The purpose of this document is to evaluate costs of characterizing one such waste type, mixed (hazardous and radioactive) waste. For the purpose of this document, waste characterization includes treatment system monitoring, where monitoring is a supplement or substitute for waste characterization. This document establishes a cost baseline for mixed waste characterization and treatment system monitoring requirements from which to evaluate alternatives. The cost baseline established as part of this work includes costs for a thermal treatment technology (i.e., a rotary kiln incinerator), a nonthermal treatment process (i.e., waste sorting, macronencapsulation, and catalytic wet oxidation), and no treatment (i.e., disposal of waste at the Waste Isolation Pilot Plant (WIPP)). The analysis of improvement over the baseline includes assessment of promising areas for technology development in front-end waste characterization, process equipment, off gas controls, and monitoring. Based on this assessment, an ideal characterization and monitoring configuration is described that minimizes costs and optimizes resources required for waste characterization

  7. Aqueous phase processing of secondary organic aerosol from isoprene photooxidation

    Science.gov (United States)

    Liu, Y.; Monod, A.; Tritscher, T.; Praplan, A. P.; DeCarlo, P. F.; Temime-Roussel, B.; Quivet, E.; Marchand, N.; Dommen, J.; Baltensperger, U.

    2012-07-01

    Transport of reactive air masses into humid and wet areas is highly frequent in the atmosphere, making the study of aqueous phase processing of secondary organic aerosol (SOA) very relevant. We have investigated the aqueous phase processing of SOA generated from gas-phase photooxidation of isoprene using a smog chamber. The SOA collected on filters was extracted by water and subsequently oxidized in the aqueous phase either by H2O2 under dark conditions or by OH radicals in the presence of light, using a photochemical reactor. Online and offline analytical techniques including SMPS, HR-AMS, H-TDMA, TD-API-AMS, were employed for physical and chemical characterization of the chamber SOA and nebulized filter extracts. After aqueous phase processing, the particles were significantly more hygroscopic, and HR-AMS data showed higher signal intensity at m/z 44 and a lower signal intensity at m/z 43, thus showing the impact of aqueous phase processing on SOA aging, in good agreement with a few previous studies. Additional offline measurement techniques (IC-MS, APCI-MS2 and HPLC-APCI-MS) permitted the identification and quantification of sixteen individual chemical compounds before and after aqueous phase processing. Among these compounds, small organic acids (including formic, glyoxylic, glycolic, butyric, oxalic and 2,3-dihydroxymethacrylic acid (i.e. 2-methylglyceric acid)) were detected, and their concentrations significantly increased after aqueous phase processing. In particular, the aqueous phase formation of 2-methylglyceric acid and trihydroxy-3-methylbutanal was correlated with the consumption of 2,3-dihydroxy-2-methyl-propanal, and 2-methylbutane-1,2,3,4-tetrol, respectively, and an aqueous phase mechanism was proposed accordingly. Overall, the aging effect observed here was rather small compared to previous studies, and this limited effect could possibly be explained by the lower liquid phase OH concentrations employed here, and/or the development of oligomers

  8. Experimental study on the separation of CO2 from flue gas using hollow fiber membrane contactors without wetting

    International Nuclear Information System (INIS)

    Experiments on CO2 removal from flue gas using polypropylene (PP) hollow fiber membrane contactors were conducted in this study. Absorbents including aqueous potassium glycinate (PG) solution, aqueous solutions of monoethanolamine (MEA) and methyldiethanolamine (MDEA) were used to absorb CO2 in the experiments. Based on the wetting experimental results, aqueous PG solution can offer a higher surface tension than water, aqueous MEA and MDEA solutions. Aqueous PG solution has a lower potential of membrane wetting after a continuously steady operation for 40 h to maintain CO2 removal efficiency of about 90%. Under moderate operating conditions, effects of the temperature, flow rate, and concentration of absorbents, and the flow rate of flue gas as well as the volumetric concentration of carbon dioxide in the flue gas on the mass transfer rate of CO2 were studied on a pilot-scale test facility. Unlike conventional absorbents, the mass transfer decreases with an increasing liquid temperature when using aqueous PG solution. Results show that CO2 removal efficiency was above 90% and the mass transfer rate was above 2.0 mol/(m2 h) using the PG aqueous solution. It indicates that the hollow fiber membrane contactor has a great potential in the area of CO2 separation from flue gas when absorbent's concentration and liquid-gas pressure difference are designed elaborately. (author)

  9. Experimental study on the separation of CO{sub 2} from flue gas using hollow fiber membrane contactors without wetting

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Shui-ping; Fang, Meng-Xiang; Zhang, Wei-Feng; Luo, Zhong-Yang; Cen, Ke-Fa [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China); Wang, Shu-Yuan; Xu, Zhi-Kang [Institute of Polymer Science, Zhejiang University, Hangzhou 310027 (China)

    2007-05-15

    Experiments on CO{sub 2} removal from flue gas using polypropylene (PP) hollow fiber membrane contactors were conducted in this study. Absorbents including aqueous potassium glycinate (PG) solution, aqueous solutions of monoethanolamine (MEA) and methyldiethanolamine (MDEA) were used to absorb CO{sub 2} in the experiments. Based on the wetting experimental results, aqueous PG solution can offer a higher surface tension than water, aqueous MEA and MDEA solutions. Aqueous PG solution has a lower potential of membrane wetting after a continuously steady operation for 40 h to maintain CO{sub 2} removal efficiency of about 90%. Under moderate operating conditions, effects of the temperature, flow rate, and concentration of absorbents, and the flow rate of flue gas as well as the volumetric concentration of carbon dioxide in the flue gas on the mass transfer rate of CO{sub 2} were studied on a pilot-scale test facility. Unlike conventional absorbents, the mass transfer decreases with an increasing liquid temperature when using aqueous PG solution. Results show that CO{sub 2} removal efficiency was above 90% and the mass transfer rate was above 2.0 mol/(m{sup 2} h) using the PG aqueous solution. It indicates that the hollow fiber membrane contactor has a great potential in the area of CO{sub 2} separation from flue gas when absorbent's concentration and liquid-gas pressure difference are designed elaborately. (author)

  10. Liquid waste treatment process - 59061

    International Nuclear Information System (INIS)

    Document available in abstract form only. Full text of publication follows: The law defined the responsibilities of the national center of nuclear energy in Morocco CNESTEN as the sole radioactive waste operating organization and designated CNESTEN as responsible for the management of radioactive waste at the national level in several social and economic sectors. The goals of the unit of radioactive waste management are: -reduce the volume of the radioactive waste product; -convert the radioactive waste into an appropriate waste for monitoring, storage and evacuation; -Recover if it's possible an element of value. The Moroccan products of radioactive liquid waste per year are 0.1 m3 of organic liquid and 35 m3 of liquid aqueous. The method adopted by CNESTEN was the evaporator for liquid aqueous and the solidification with the activated carbon for the organic liquid. An evaporation installation to treat 5 m3 of aqueous liquid in each campaign, the volume of the sludge obtained is 200 liters and 4800 liters of distillate water. Concerning the management system is plan to collect the liquid aqueous in tanks in the bottom of each nuclear installation. After characterization according to the technical specification of radioactive waste management nuclear installation, the waste is transported in an appropriate tank to the treatment building to be evaporated. After treatment the clean water is collect in a separate tank waiting its discharge if it complies with the requirements of release. The volume of sludge issued from evaporator is conditioning with mortar (40 liters) in 120 liters drum, the mixing operation is ensured by shingles introduced in the drum and the rotation of the drum is ensured by a mixer named 'turn drums'. The drum must respect the acceptance criteria before transferred to storage building. About the liquid organic waste was collected in the polyethylene move tank; this kind of waste is mixed to an absorbent product and conditioned like the sludge

  11. Phase formation and chemical phase equilibria in aqueous-based systems pertinent to waste-management: calcium oxide-alluminum oxide-borate-water, calcium oxide-lead oxide-phosphate-water and calcium oxide-arsenate-water

    Science.gov (United States)

    Bothe, James Vincent, Jr.

    This thesis explores three aqueous-based systems that have importance in the area of waste-management: (1) CaO-Alsb2Osb3-Bsb2Osb3-Hsb2O, (2) CaO-PbO-Psb2Osb5-Hsb2O and (3) CaO-Assb2Osb5-Hsb2O. More specifically, the objective of this research is to identify various precipitated compounds that can effectively immobilize certain elements that either directly or indirectly have an adverse effect on the environment. In the first quaternary system, CaO-Alsb2Osb3-Bsb2Osb3-Hsb2O, boron is the element desired to be ``fixed'' because ``free'' boron is the cause of delayed hardening in cement paste intended for the encapsulation of nuclear waste. Soluble boron also causes the cement paste to prematurely set, a phenomenon called ``flash-set.'' Isothermal calorimetry was used to track the progress of tricalcium aluminate hydration in the presence of boric acid and Ca(OH)sb2 and revealed the presence of a pronounced induction period, the length of which varied with both temperature and boric acid concentration. It was determined that a diffusion barrier, most likely an amorphous calcium borate, deposited onto the active anhydrous tricalcium aluminate grains inhibiting further hydration. Also, under certain conditions, the precipitation of crystalline 4CaO{*}Alsb2Osb3{*}1/2Bsb2Osb3{*}12Hsb2O may be responsible for the observed flash-set due to its flat, plate-like morphology. Another quaternary hydrate, 6CaO{*}Alsb2Osb3{*}2Bsb2Osb3{*}39Hsb2O (boro-ettringite) was also synthesized during this research and crystallized as hexagonal prisms. In contrast to the fast crystallization of 4CaO{*}Alsb2Osb3{*}1/2Bsb2Osb3{*}12Hsb2O, boro-ettringite was observed to form slowly and in stages with the precipitation of the transient phase CaO-Bsb2Osb3{*}6Hsb2O preceding it. Further investigation of these two hydrates lead to the construction of a quaternary phase diagram and to the determination of their solubility products (pKsp = -logKsp), which were determined to be 44.23 for boro

  12. Drop splashing is independent of substrate wetting

    CERN Document Server

    Latka, Andrzej; Nagel, Sidney R; de Pablo, Juan J

    2016-01-01

    A liquid drop impacting a dry solid surface with sufficient kinetic energy will splash, breaking apart into numerous secondary droplets. This phenomenon shows many similarities to forced wetting, including the entrainment of air at the contact line. Because of these similarities and the fact that forced wetting has been shown to depend on the wetting properties of the surface, existing theories predict splashing to depend on wetting properties as well. However, using high-speed interference imaging we observe that wetting properties have no effect on splashing for various liquid-surface combinations. Additionally, by fully resolving the Navier-Stokes equations at length and time scales inaccessible to experiments, we find that the shape and motion of the air-liquid interface at the contact line are independent of wettability. We use these findings to evaluate existing theories and to compare splashing with forced wetting.

  13. Mixed Waste Management Facility

    International Nuclear Information System (INIS)

    The DOE has developed a National Mixed Waste Strategic Plan which calls for the construction of 2 to 9 mixed waste treatment centers in the Complex in the near future. LLNL is working to establish an integrated mixed waste technology development and demonstration system facility, the Mixed Waste Management Facility (MWMF), to support the DOE National Mixed Waste Strategic Plan. The MWMF will develop, demonstrate, test, and evaluate incinerator-alternatives which will comply with regulations governing the treatment and disposal of organic mixed wastes. LLNL will provide the DOE with engineering data for design and operation of new technologies which can be implemented in their mixed waste treatment centers. MWMF will operate under real production plant conditions and process samples of real LLNL mixed waste. In addition to the destruction of organic mixed wastes, the development and demonstration will include waste feed preparation, material transport systems, aqueous treatment, off-gas treatment, and final forms, thus making it an integrated ''cradle to grave'' demonstration. Technologies from offsite as well as LLNL's will be tested and evaluated when they are ready for a pilot scale demonstration, according to the needs of the DOE

  14. Non-aqueous phase liquid spreading during soil vapor extraction

    OpenAIRE

    Kneafsey, Timothy J.; HUNT, JAMES R.

    2004-01-01

    Many non-aqueous phase liquids (NAPLs) are expected to spread at the air – water interface, particularly under non-equilibrium conditions. In the vadose zone, this spreading should increase the surface area for mass transfer and the efficiency of volatile NAPL recovery by soil vapor extraction (SVE). Observations of spreading on water wet surfaces led to a conceptual model of oil spreading vertically above a NAPL pool in the vadose zone. Analysis of this model predicts that spreading can enha...

  15. Wetting on Lines and Lattices of Cylinders

    OpenAIRE

    Osborn, W. R.; Yeomans, J. M.

    1994-01-01

    This paper discusses wetting and capillary condensation transitions on a line and a rectangular array of cylinders using an interface potential formalism. For a line of cylinders, there is a capillary condensation transition followed by complete wetting if the cylinders are sufficiently close together. Both transitions disappear as the cylinder separation is increased. The dependence of the wetting phase diagram of a rectangular array of cylinders is discussed as a function of the chemical po...

  16. Catalytic wet air oxidation of organic pollutants in waste waters

    OpenAIRE

    Gomes, Helder; Figueiredo, José; Boaventura, Rui; Faria, Joaquim

    2001-01-01

    Organic compounds are involved iii the manufacture of a wide variety of chemical products, generating in the process different kinds of liquid effluents with high chemical oxygen demand (COD) and high toxicity. Discharge of these waters without treatment into a river course is unacceptable, due to the toxic potential of some organic compounds or to depletion of the dissolved oxygen level, which can decrease below the level considered necessary to support aquatic life.

  17. Carbon nanotube fiber spun from wetted ribbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  18. A mesoscopic model for (de)wetting.

    Science.gov (United States)

    Merabia, S; Pagonabarraga, I

    2006-06-01

    We present a mesoscopic model for simulating the dynamics of a non-volatile liquid on a solid substrate. The wetting properties of the solid can be tuned from complete wetting to total non-wetting. This model opens the way to study the dynamics of drops and liquid thin films at mesoscopic length scales of the order of the nanometer. As particular applications, we analyze the kinetics of spreading of a liquid drop wetting a solid substrate and the dewetting of a liquid film on a hydrophobic substrate. In all these cases, very good agreement is found between simulations and theoretical predictions. PMID:16775662

  19. Substrate-induced coagulation (SIC) of nano-disperse alumina in non-aqueous media: The dispersibility and stability of alumina in N-methyl-2-pyrrolidinone

    OpenAIRE

    Basch, Angelika; Strnad, Simona

    2011-01-01

    This work investigated colloidal properties such as the zeta-potential, the electrophoretic mobilities and the wetting behaviour of alumina dispersed in non-aqueous media. Non-aqueous dispersions of alumina were prepared in the solvent N-methyl-2-pyrrolidinone (NMP). The wetting behaviour of alumina in NMP was characterized by the powder contact angle method and the Wilhemy plate method. The behaviour of the dispersion should provide information for the development of a substrate-induced coag...

  20. Wet Electrolytic Oxidation of Organics and Application for Sludge Treatment

    Science.gov (United States)

    Serikawa, Roberto M.

    Wet electrolytic oxidation (WEO) is electrochemical oxidation conducted at subcritical water temperature and pressure. Under these conditions, the electrolytic reaction of water is very different from the reaction usually seen in water electrolysis. Electrolysis of an aqueous NaCl solution at 250°C proceeds without the evolution of any oxygen, chlorine or even hydrogen. Rapid oxidation of organics to CO2 occurs in WEO with the production of hydrogen. Further addition of an oxidizer enhances the electrochemical oxidation of organics with the suppression of hydrogen evolution. AOX compounds found in usual electrooxidation are not formed in WEO treatment. When WEO is applied to sludge treatment, colors are drastically reduced and there is an increase in the yield of organic acids. The biodegradability increases by up to 50% and the treated water shows higher methane yields during anaerobic fermentation.

  1. Experimental studies of buffer gap filling with artificial wetting

    Energy Technology Data Exchange (ETDEWEB)

    Holt, E.; Loeija, M.; Fortino, S.; Marjavaara, P. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2014-02-15

    The purpose of this work was to continue investigates on the swelling behaviour of artificially wetted highly compacted bentonite buffer blocks used in deposition holes for nuclear waste containment. The target was to study how filling the gap between the buffer block and deposition hole with wetted materials could create homogeneous and rapid swelling pressure. It is expected that the thermal, mechanical, chemical and hydraulic properties of the whole deposition system would be better when the bentonite-rock gap is closed with a uniform material. In practice, it is desirable that the bentonite material has a volume increase sufficient enough to create pressure against the rock surface. Uniform bentonite buffer swelling into the gap would prevent rock spalling while lowering the risks of bentonite piping and erosion due to potential water flow. In this work bentonite blocks were confined in a test chamber and bentonite material was added to the gap with additional artificial wetting to induce swelling. The resulting gap material and buffer bentonite generated swelling pressure in both the radial and vertical directions which was measured over time. Eighteen different test scenarios were investigated, including: variation of gap size, use of three different pellet types, use of three different bentonite slurry fillings, use of groundwater compared to tap water, and uniaxial compared to isostatic buffer blocks. After the wetting tests, material properties of the swollen buffer were measured, including measurements of moisture content, SHORE hardness, and density. This study also had a portion on 2D modelling of the bentonite swelling during the early ages, with either pellets or water added to the gap. Results from earlier studies were used to establish the models, which were then verified with the current experiments for time of developing swelling pressure. The results of this work showed that the use of gap filling bentonite material combined with artificial

  2. Experimental studies of buffer gap filling with artificial wetting

    International Nuclear Information System (INIS)

    The purpose of this work was to continue investigates on the swelling behaviour of artificially wetted highly compacted bentonite buffer blocks used in deposition holes for nuclear waste containment. The target was to study how filling the gap between the buffer block and deposition hole with wetted materials could create homogeneous and rapid swelling pressure. It is expected that the thermal, mechanical, chemical and hydraulic properties of the whole deposition system would be better when the bentonite-rock gap is closed with a uniform material. In practice, it is desirable that the bentonite material has a volume increase sufficient enough to create pressure against the rock surface. Uniform bentonite buffer swelling into the gap would prevent rock spalling while lowering the risks of bentonite piping and erosion due to potential water flow. In this work bentonite blocks were confined in a test chamber and bentonite material was added to the gap with additional artificial wetting to induce swelling. The resulting gap material and buffer bentonite generated swelling pressure in both the radial and vertical directions which was measured over time. Eighteen different test scenarios were investigated, including: variation of gap size, use of three different pellet types, use of three different bentonite slurry fillings, use of groundwater compared to tap water, and uniaxial compared to isostatic buffer blocks. After the wetting tests, material properties of the swollen buffer were measured, including measurements of moisture content, SHORE hardness, and density. This study also had a portion on 2D modelling of the bentonite swelling during the early ages, with either pellets or water added to the gap. Results from earlier studies were used to establish the models, which were then verified with the current experiments for time of developing swelling pressure. The results of this work showed that the use of gap filling bentonite material combined with artificial

  3. Assessing the emission sources of atmospheric mercury in wet deposition across Illinois.

    Science.gov (United States)

    Gratz, Lynne E; Keeler, Gerald J; Morishita, Masako; Barres, James A; Dvonch, J Timothy

    2013-03-15

    From August 4, 2007 to August 31, 2009, we collected event-based precipitation samples for mercury (Hg) and trace element analyses at four sites in Illinois (IL), USA. The objectives of these measurements were to quantify Hg wet deposition across the state, and to assess the contributions to Hg in precipitation from major local and regional emission sources. Monitoring sites were located, from north to south, in Chicago, Peoria, Nilwood, and Carbondale, IL. Measurements from these four sites demonstrated that a clear spatial gradient in Hg wet deposition was not evident across the state. Each site received>10μgm(-2) of Hg wet deposition annually, and these observed values were comparable to annual Hg wet deposition measurements from other event-based precipitation monitoring sites in source-impacted areas of the Midwestern U.S. We applied the multivariate statistical receptor model, Positive Matrix Factorization (EPA PMF v3.0), to the measured Hg and trace element wet deposition amounts at the four sites. Results suggested that 50% to 74% of total Hg wet deposition at each site could be attributed to coal combustion emissions. The other source signatures identified in the precipitation compositions included cement manufacturing, mixed metal smelting/waste incineration, iron-steel production, and a phosphorus source. We also applied a hybrid receptor model, Quantitative Transport Bias Analysis (QTBA), to the Hg wet deposition datasets to identify the major source regions associated with the measured values. The calculated QTBA probability fields suggested that transport from urban/industrial areas, such as Chicago/Gary, St. Louis, and the Ohio River Valley, resulted in some of the highest estimated event-based Hg wet deposition amounts at the four sites (potential mass transfer of up to 0.32μgm(-2)). The combined application of PMF and QTBA supported the hypothesis that local and regional coal combustion was the largest source of Hg wet deposition in Illinois

  4. Combined wet and dry cleaning of SiGe(001)

    International Nuclear Information System (INIS)

    Combined wet and dry cleaning via hydrofluoric acid (HF) and atomic hydrogen on Si0.6Ge0.4(001) surface was studied at the atomic level using ultrahigh vacuum scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and x-ray photoelectron spectroscopy to understand the chemical transformations of the surface. Aqueous HF removes native oxide, but residual carbon and oxygen are still observed on Si0.6Ge0.4(001) due to hydrocarbon contamination from post HF exposure to ambient. The oxygen contamination can be eliminated by shielding the sample from ambient via covering the sample in the HF cleaning solution until the sample is introduced to the vacuum chamber or by transferring the sample in an inert environment; however, both processes still leave carbon contaminant. Dry in-situ atomic hydrogen cleaning above 330 °C removes the carbon contamination on the surface consistent with a thermally activated atomic hydrogen reaction with surface hydrocarbon. A postdeposition anneal at 550 °C induces formation of an atomically flat and ordered SiGe surface observed by STM. STS verifies that the wet and dry cleaned surface has an unpinned Fermi level with no states between the conduction and valence band edge comparable to sputter cleaned SiGe surfaces

  5. Combined wet and dry cleaning of SiGe(001)

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang Wook; Kaufman-Osborn, Tobin; Kim, Hyonwoong [Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093 (United States); Siddiqui, Shariq; Sahu, Bhagawan [TD Research, GLOBALFOUNDRIES USA, Inc., 257 Fuller Road, Albany, New York 12203 (United States); Yoshida, Naomi; Brandt, Adam [Applied Materials, Inc., Santa Clara, California 95054 (United States); Kummel, Andrew C., E-mail: akummel@ucsd.edu [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093 (United States)

    2015-07-15

    Combined wet and dry cleaning via hydrofluoric acid (HF) and atomic hydrogen on Si{sub 0.6}Ge{sub 0.4}(001) surface was studied at the atomic level using ultrahigh vacuum scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and x-ray photoelectron spectroscopy to understand the chemical transformations of the surface. Aqueous HF removes native oxide, but residual carbon and oxygen are still observed on Si{sub 0.6}Ge{sub 0.4}(001) due to hydrocarbon contamination from post HF exposure to ambient. The oxygen contamination can be eliminated by shielding the sample from ambient via covering the sample in the HF cleaning solution until the sample is introduced to the vacuum chamber or by transferring the sample in an inert environment; however, both processes still leave carbon contaminant. Dry in-situ atomic hydrogen cleaning above 330 °C removes the carbon contamination on the surface consistent with a thermally activated atomic hydrogen reaction with surface hydrocarbon. A postdeposition anneal at 550 °C induces formation of an atomically flat and ordered SiGe surface observed by STM. STS verifies that the wet and dry cleaned surface has an unpinned Fermi level with no states between the conduction and valence band edge comparable to sputter cleaned SiGe surfaces.

  6. Characteristics of wet work in nurses

    NARCIS (Netherlands)

    Jungbauer, FHW; Steenstra, FB; Groothoff, JW; Coenraads, PJ

    2005-01-01

    Background objectives: Nursing is known for its high prevalence of hand dermatitis, mainly caused by the intense exposure to wet work in nursing activities. We aimed to study the characteristics of wet work exposure in nursing. Method: Trained observers monitored the duration and frequency of differ

  7. Anomalous wetting of helium on cesium

    International Nuclear Information System (INIS)

    The authors report studies of the anomalous wetting of a cesium substrate by a liquid helium film by means of the technique of third sound. A hysteretic pre-wetting transition is observed as a function of the amount of helium in the experimental cell. 10 refs., 2 figs

  8. Developments in ethanol production from citrus peel waste

    Science.gov (United States)

    Each year, the Florida citrus juice industry produces about 3.5~5.0 million tons of wet peel waste, which are currently dried and sold as cattle feed, often at a loss, to dispose of the waste residual. Profitability would be greatly improved if the peel waste could be used to produce higher value pr...

  9. Economic analysis of ethanol production from citrus peel waste

    Science.gov (United States)

    The Florida citrus juice industry produces about 3.5 million tons of wet peel waste per year. In current industrial practice, waste peels are dried and sold as cattle feed to offset the waste disposal cost. Profitability would be greatly improved if peels could be used to produce higher value produ...

  10. Long term wet spent nuclear fuel storage

    International Nuclear Information System (INIS)

    The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included

  11. Raman spectroscopy application to analyses of components in aqueous solutions

    Science.gov (United States)

    Li, Gang; Zhang, Guoping

    2006-09-01

    The characterization of species in aqueous solutions has presented a challenge to analytical and physical chemist, because the JR absorption of the aqueous solvent is so intense that it becomes difficult to observe the solute in the water by JR absorption. In contrast, Raman spectrum of the solute is unaffected by the water, so the weak scattering of water makes the technique well suited to aqueous samples, and the Raman spectrum exhibits well-defined bands corresponding to fundamental modes of vibration. In addition, Raman spectroscopy has some inherent advantages in aqueous solution analysis, because the spectral features of signals from different species are much more distinct, and it provides characteristic signatures for samples, such as blood, protein and cholesterol. All the advantages make Raman spectroscopy be a potential alternative for the study of aqueous solutions. Now, Raman spectroscopy has been applied to studying samples in aqueous solutions, blood serum, intracellular protein levels. Now, industrial wasted water contains many organic contaminants, and it is necessary to determine and monitor these contaminants. The paper first introduces Raman spectroscopy, and then describes its applications to determining the components in aqueous solutions, analyzes and assignes the Raman spectra of o-dichlorobenzene, o-xylene, m-xyiene and p-xylene in detail. The experimental results demonstrate that Raman spectroscopy is a particularly powerful technique for aqueous solutions analyses.

  12. Aqueous Computing:A Survey with an Invitation to Participate

    Institute of Scientific and Technical Information of China (English)

    Tom Head; Xia Chen; Masayuki Yamamura; Susannah Gal

    2002-01-01

    The concept of aqueous computing is presented here, first in full generality,and afterward, using an implementation in a specific enzymatic technology. Aqueous computingarose in the context of biomolecular (DNA) computing, but the concept is independent ofthe specifics of its biochemical origin. Alternate technologies for realizing aqueous computingare being considered for future implementation. A solution of an instance of the Booleansatisfiability problem, (SAT), is reported here that provides a new example of an aqueouscomputation that has been carried out successfully. This small instance of the SAT problemis sufficiently complex to allow our current enzymatic technology to be illustrated in detail.The reader is invited to participate in the rich interdisciplinary activity required by wet labcomputing. A project is suggested to the reader for determining the three-colorings of a graph.The basic operations required for this project are exhibited in the solution of the SAT examplereported here.

  13. Cost benefits from applying advanced heat rejection concepts to a wet/dry-cooled binary geothermal plant

    Energy Technology Data Exchange (ETDEWEB)

    Faletti, D.W.

    1981-03-01

    Optimized ammonia heat rejection system designs were carried out for three water allocations equivalent to 9, 20, and 31% of that of a 100% wet-cooled plant. The Holt/Procon design of a 50-MWe binary geothermal plant for the Heber site was used as a design basis. The optimization process took into account the penalties for replacement power, gas turbine capital, and lost capacity due to increased heat rejection temperature, as well as added base plant capacity and fuel to provide fan and pump power to the heat rejection system. Descriptions of the three plant designs are presented. For comparison, a wet tower loop was costed out for a 100% wet-cooled plant using the parameters of the Holt/Procon design. Wet/dry cooling was found to increase the cost of electricity by 28% above that of a 100% wet-cooled plant for all three of the water allocations studied (9, 20, and 31%). The application selected for a preconceptual evaluation of the BCT (binary cooling tower) system was the use of agricultural waste water from the New River, located in California's Imperial Valley, to cool a 50-MWe binary geothermal plant. Technical and cost evaluations at the preconceptual level indicated that performance estimates provided by Tower Systems Incorporated (TSI) were reasonable and that TSI's tower cost, although 2 to 19% lower than PNL estimates, was also reasonable. Electrical cost comparisonswere made among the BCT system, a conventional 100% wet system, and a 9% wet/dry ammonia system, all using agricultural waste water with solar pond disposal. The BCT system cost the least, yielding a cost of electricity only 13% above that of a conventional wet system using high quality water and 14% less than either the conventional 100% wet or the 9% wet/dry ammonia system.

  14. Precursor films in wetting phenomena

    International Nuclear Information System (INIS)

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in the last decade similar films have been reported to occur in solid-on-solid systems. While the situations in which the thickness of such films is of mesoscopic size are fairly well understood, an intriguing and yet to be fully understood aspect is the spreading of microscopic, i.e. molecularly thin, films. Here we review the available experimental observations of such films in various liquid-on-solid and solid-on-solid systems, as well as the corresponding theoretical models and studies aimed at understanding their formation and spreading dynamics. Recent developments and perspectives for future research are discussed. (topical review)

  15. Precursor films in wetting phenomena.

    Science.gov (United States)

    Popescu, M N; Oshanin, G; Dietrich, S; Cazabat, A-M

    2012-06-20

    The spontaneous spreading of non-volatile liquid droplets on solid substrates poses a classic problem in the context of wetting phenomena. It is well known that the spreading of a macroscopic droplet is in many cases accompanied by a thin film of macroscopic lateral extent, the so-called precursor film, which emanates from the three-phase contact line region and spreads ahead of the latter with a much higher speed. Such films have been usually associated with liquid-on-solid systems, but in the last decade similar films have been reported to occur in solid-on-solid systems. While the situations in which the thickness of such films is of mesoscopic size are fairly well understood, an intriguing and yet to be fully understood aspect is the spreading of microscopic, i.e. molecularly thin, films. Here we review the available experimental observations of such films in various liquid-on-solid and solid-on-solid systems, as well as the corresponding theoretical models and studies aimed at understanding their formation and spreading dynamics. Recent developments and perspectives for future research are discussed. PMID:22627067

  16. Role of drug substance material properties in the processibility and performance of a wet granulated product.

    Science.gov (United States)

    Vemavarapu, Chandra; Surapaneni, Madhu; Hussain, Munir; Badawy, Sherif

    2009-06-01

    The purpose of this study was to establish a relationship between the material properties of an active pharmaceutical ingredient (API) and its behavior during high-shear wet granulation. Using several actives and excipients as material probes, the influence of aqueous solubility, wettability, water holding capacity, mean and width of the particle size distribution, and surface area was examined. The effect of these variables on the processibility and performance of the granulations was evaluated by monitoring such responses as granule growth, compactability and flow changes upon wet granulation. The prominent findings from this study include: (a) controlled growth is highest in readily wettable APIs with low surface area, (b) uncontrolled growth is high in APIs of high solubility and low water holding capacity, (c) polydisperse granulations are produced from APIs of high contact angle and surface area, (d) improvement in compactability is high in APIs with large surface area and broader size distributions and (e) flow enhancement as a result of wet granulation is highest in APIs of large size distributions. These results are physically interpreted in this manuscript based on the prevailing wet granulation theories. Findings from this study are useful in mapping a new material to predict its performance in a high-shear wet granulation process. PMID:19446765

  17. Surrogate formulations for thermal treatment of low-level mixed waste, Part II: Selected mixed waste treatment project waste streams

    International Nuclear Information System (INIS)

    This report summarizes the formulation of surrogate waste packages, representing the major bulk constituent compositions for 12 waste stream classifications selected by the US DOE Mixed Waste Treatment Program. These waste groupings include: neutral aqueous wastes; aqueous halogenated organic liquids; ash; high organic content sludges; adsorbed aqueous and organic liquids; cement sludges, ashes, and solids; chloride; sulfate, and nitrate salts; organic matrix solids; heterogeneous debris; bulk combustibles; lab packs; and lead shapes. Insofar as possible, formulation of surrogate waste packages are referenced to authentic wastes in inventory within the DOE; however, the surrogate waste packages are intended to represent generic treatability group compositions. The intent is to specify a nonradiological synthetic mixture, with a minimal number of readily available components, that can be used to represent the significant challenges anticipated for treatment of the specified waste class. Performance testing and evaluation with use of a consistent series of surrogate wastes will provide a means for the initial assessment (and intercomparability) of candidate treatment technology applicability and performance. Originally the surrogate wastes were intended for use with emerging thermal treatment systems, but use may be extended to select nonthermal systems as well

  18. Pulsed corona discharge oxidation of aqueous lignin: decomposition and aldehydes formation.

    Science.gov (United States)

    Panorel, Iris; Kaijanen, Laura; Kornev, Iakov; Preis, Sergei; Louhi-Kultanen, Marjatta; Sirén, Heli

    2014-01-01

    Lignin is the mass waste product of pulp and paper industry mostly incinerated for energy recovery. Lignin is, however, a substantial source of raw material for derivatives currently produced in costly wet oxidation processes. The pulsed corona discharge (PCD) for the first time was applied to lignin oxidation aiming a cost-effective environmentally friendly lignin removal and transformation to aldehydes. The experimental research into treatment of coniferous kraft lignin aqueous solutions was undertaken to establish the dependence of lignin oxidation and aldehyde formation on the discharge parameters, initial concentration of lignin and gas phase composition. The rate and the energy efficiency of lignin oxidation increased with increasing oxygen concentration reaching up to 82 g kW-1 h-1 in 89% vol. oxygen. Oxidation energy efficiency in PCD treatment exceeds the one for conventional ozonation by the factor of two under the experimental conditions. Oxidation at low oxygen concentrations showed a tendency of the increasing aldehydes and glyoxylic acid formation yield. PMID:24600854

  19. Waste: energy to burn

    International Nuclear Information System (INIS)

    Incinerated, transformed into fuel or a gas, waste is a versatile source of energy. It is as once a problem and a resource that is increasingly the focus of green policies. According to the 2009 World Waste Survey, between 3.4 and 4 billion tons of waste are produced each year worldwide. Leading the pack is China, with 300 million tons produced in 2005, followed closely by the United States, with 238 million tons. But the United States wins the per capita count with 760 kg of waste produced per year per inhabitant; Australia comes in second. In Europe, 500 kg of waste is produced per capita per year for a total of 2 billion tons generated annually, and a growth rate of 10% in ten years' time. Between 2/3 and 3/4 of these waste materials are sorted, and a portion of them is recycled. The rest is either carted away to a dumping ground, or incinerated. But this waste is primarily domestic, and still contains energy, energy that can be recovered. The added bonus is two-fold: an additional source of energy is created by transforming waste, called waste-to- wheel or waste-to-energy (WTE), and the decomposition of organic waste does not give off GHGs. Two ways are known today to transform wastes into energy: the thermal process, where heat is extracted from the waste (and sometimes converted into electricity), and the non-thermal process, which comprises collecting energy in a chemical form (biogas, biofuel). Both technologies depend on the type of waste to be treated: plastic materials, household refuse, fermentable elements, sludge residue from sewage treatment plants, agricultural waste, forestry industry waste, etc. The thermal process is by far the most widely employed. 74% of waste is incinerated in Japan, and around 30 to 55% in most European countries. The second process does not burn waste and is better suited to wet and organic matter, i.e., to waste that contains quantities of biomass: fermentable waste, sludge, agricultural waste and the gas given off at

  20. Cloud condensation nuclei activity and droplet activation kinetics of wet processed regional dust samples and minerals

    Directory of Open Access Journals (Sweden)

    P. Kumar

    2011-08-01

    Full Text Available This study reports laboratory measurements of particle size distributions, cloud condensation nuclei (CCN activity, and droplet activation kinetics of wet generated aerosols from clays, calcite, quartz, and desert soil samples from Northern Africa, East Asia/China, and Northern America. The dependence of critical supersaturation, sc, on particle dry diameter, Ddry, is used to characterize particle-water interactions and assess the ability of Frenkel-Halsey-Hill adsorption activation theory (FHH-AT and Köhler theory (KT to describe the CCN activity of the considered samples. Wet generated regional dust samples produce unimodal size distributions with particle sizes as small as 40 nm, CCN activation consistent with KT, and exhibit hygroscopicity similar to inorganic salts. Wet generated clays and minerals produce a bimodal size distribution; the CCN activity of the smaller mode is consistent with KT, while the larger mode is less hydrophilic, follows activation by FHH-AT, and displays almost identical CCN activity to dry generated dust. Ion Chromatography (IC analysis performed on regional dust samples indicates a soluble fraction that cannot explain the CCN activity of dry or wet generated dust. A mass balance and hygroscopicity closure suggests that the small amount of ions (from low solubility compounds like calcite present in the dry dust dissolve in the aqueous suspension during the wet generation process and give rise to the observed small hygroscopic mode. Overall these results identify an artifact that may question the atmospheric relevance of dust CCN activity studies using the wet generation method.

    Based on the method of threshold droplet growth analysis, wet generated mineral aerosols display similar activation kinetics compared to ammonium sulfate calibration aerosol. Finally, a unified CCN activity framework that accounts for concurrent effects of solute and adsorption is developed to

  1. Order of wetting transitions in electrolyte solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ibagon, Ingrid, E-mail: ingrid@is.mpg.de; Bier, Markus, E-mail: bier@is.mpg.de; Dietrich, S. [Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, 70569 Stuttgart, Germany and IV. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart (Germany)

    2014-05-07

    For wetting films in dilute electrolyte solutions close to charged walls we present analytic expressions for their effective interface potentials. The analysis of these expressions renders the conditions under which corresponding wetting transitions can be first- or second-order. Within mean field theory we consider two models, one with short- and one with long-ranged solvent-solvent and solvent-wall interactions. The analytic results reveal in a transparent way that wetting transitions in electrolyte solutions, which occur far away from their critical point (i.e., the bulk correlation length is less than half of the Debye length) are always first-order if the solvent-solvent and solvent-wall interactions are short-ranged. In contrast, wetting transitions close to the bulk critical point of the solvent (i.e., the bulk correlation length is larger than the Debye length) exhibit the same wetting behavior as the pure, i.e., salt-free, solvent. If the salt-free solvent is governed by long-ranged solvent-solvent as well as long-ranged solvent-wall interactions and exhibits critical wetting, adding salt can cause the occurrence of an ion-induced first-order thin-thick transition which precedes the subsequent continuous wetting as for the salt-free solvent.

  2. Order of wetting transitions in electrolyte solutions

    International Nuclear Information System (INIS)

    For wetting films in dilute electrolyte solutions close to charged walls we present analytic expressions for their effective interface potentials. The analysis of these expressions renders the conditions under which corresponding wetting transitions can be first- or second-order. Within mean field theory we consider two models, one with short- and one with long-ranged solvent-solvent and solvent-wall interactions. The analytic results reveal in a transparent way that wetting transitions in electrolyte solutions, which occur far away from their critical point (i.e., the bulk correlation length is less than half of the Debye length) are always first-order if the solvent-solvent and solvent-wall interactions are short-ranged. In contrast, wetting transitions close to the bulk critical point of the solvent (i.e., the bulk correlation length is larger than the Debye length) exhibit the same wetting behavior as the pure, i.e., salt-free, solvent. If the salt-free solvent is governed by long-ranged solvent-solvent as well as long-ranged solvent-wall interactions and exhibits critical wetting, adding salt can cause the occurrence of an ion-induced first-order thin-thick transition which precedes the subsequent continuous wetting as for the salt-free solvent

  3. Lyophilization -Solid Waste Treatment

    Science.gov (United States)

    Litwiller, Eric; Flynn, Michael; Fisher, John; Reinhard, Martin

    2004-01-01

    This paper discusses the development of a solid waste treatment system that has been designed for a Mars transit exploration mission. The technology described is an energy-efficient lyophilization technique that is designed to recover water from spacecraft solid wastes. Candidate wastes include feces, concentrated brines from water processors, and other solid wastes that contain free water. The system is designed to operate as a stand-alone process or to be integrated into the International Space Station Waste Collection System. In the lyophilization process, water in an aqueous waste is frozen and then sublimed, separating the waste into a dried solid material and liquid water. The sublimed water is then condensed in a solid ice phase and then melted to generate a liquid product. In the subject system the waste solids are contained within a 0.2 micron bio-guard bag and after drying are removed from the system and stored in a secondary container. This technology is ideally suited to applications such as the Mars Reference Mission, where water recovery rates approaching 100% are desirable but production of CO2 is not. The system is designed to minimize power consumption through the use of thermoelectric heat pumps. The results of preliminary testing of a prototype system and testing of the final configuration are provided. A mathematical model of the system is also described.

  4. Wetting reversal in colloid-polymer systems.

    Science.gov (United States)

    Blokhuis, Edgar M; Kuipers, Joris

    2010-05-01

    The wetting of a phase-separated colloid-polymer mixture in contact with a hard wall is analyzed using free volume theory in a Nakanishi-Fisher-type approach. We present results for the wetting phase diagram for several model approximations. Our analysis is compared with a previous analysis by Aarts [J. Chem. Phys. 120, 1973 (2004)]. We find that there is a crossover from wetting to drying at a threshold value for the colloid-polymer size ratio and that the transitions are close to the critical point and of second order in nature. PMID:20866234

  5. Propene Hydroformylation by Supported Aqueous-phase Rh-NORBOS Catalysts

    DEFF Research Database (Denmark)

    Riisager, Anders; Eriksen, Kim Michael; Hjortkjær, Jes; Fehrmann, Rasmus

    The gas-phase hydroformylation reaction of propene using supported aqueous-phase (SAP) Rh-NORBOS modified catalysts in a continuous flow reactor has been examined. SAP catalysts supported on six different support materials were made by wet impregnation using solutions of the precursor complex Rh(...

  6. Grinding and cooking dry-mill germ to optimize aqueous enzymatic oil extraction

    Science.gov (United States)

    The many recent dry grind plants that convert corn to ethanol are potential sources of substantial amounts of corn oil. This report describes an aqueous enzymatic extraction (AEE) method to separate oil from dry-mill corn germ (DMG). The method is an extension of AEE previously developed for wet...

  7. Assessing the Emission Sources of Atmospheric Mercury in Wet Deposition Across Illinois, USA

    Directory of Open Access Journals (Sweden)

    Gratz L. E.

    2013-04-01

    Full Text Available From August 2007 to August 2009, we collected event-based precipitation samples for mercury (Hg and trace element analysis at four sites in Illinois, USA. The objectives of these measurements were to quantify the levels of Hg wet deposition across the state, and to assess the contributions to Hg in precipitation from major local and regional emission sources. The measurement sites were located in Chicago, Peoria, Nilwood, and Carbondale, IL. We were not able to identify a clear spatial gradient in Hg wet deposition among the sites. At all four locations we frequently observed Hg concentrations in precipitation > 25 ng/L, while each site received > 10 μg/m2 of Hg wet deposition annually, suggesting a substantial impact from local and regional anthropogenic emission sources. We applied the multivariate statistical receptor model Positive Matrix Factorization (PMF to the measured Hg and trace element wet deposition amounts at the four sites. The results suggested that 60-83% of total Hg deposition at each site could be attributed to coal combustion emissions. Although we identified other source signatures in the precipitation composition, including cement manufacturing, metal smelting / waste incineration, and iron-steel production, these sources contributed substantially less to the measured amounts of Hg wet deposition. We also applied the hybrid receptor model Quantitative Transport Bias Analysis (QTBA to the Hg wet deposition data from each site to identify the major source regions associated with the measured values. Results suggested that sources in the Chicago/Gary, St. Louis, and Ohio River Valley urban/industrial areas had a substantial impact on Hg wet deposition, strongly supporting the conclusion that local and regional coal combustion was the largest source of Hg wet deposition in Illinois.

  8. Evaluating the biochemical methane potential (BMP) of low-organic waste at Danish landfills

    DEFF Research Database (Denmark)

    Mou, Zishen; Scheutz, Charlotte; Kjeldsen, Peter

    2014-01-01

    carbon content (DOCC) was in the range of 0.44–0.70% of total weight (wet waste). Numeric values of both parameters were much lower than values of traditional municipal solid waste (MSW), as well as default numeric values in current FOD models. The sludge waste and temporarily stored combustible waste...

  9. Comparative study of aqueous and solvent methods for cleaning metals

    International Nuclear Information System (INIS)

    Studies were performed to determine the comparative effectiveness of solvent and aqueous detergent methods for cleaning various metals. The metals investigated included 304L stainless steel, beryllium, uranium-6.5 wt percent niobium alloy, and unalloyed uranium (238U). The studies were initiated in response to governmental regulations restricting the use of some chlorinated solvents. Results showed that aqueous detergent cleaning was more effective than solvents, i.e. trichloroethylene and methyl chloroform, for the removal of light industrial soils. The subsequent adoption of aqueous cleaning at this plant has facilitated waste disposal, which contributed to recorded economic savings. The controlled use of aqueous detergents is environmentally acceptable and has decreased the hazards of fire and toxicity that are generally associated with solvents. 8 tables, 15 figures

  10. Tualatin River - Wet Prairie Restoration Phase III

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Forty five acres of wet prairie and 11 acres of adjacent lands were treated for reed canarygrass in this ongoing project. Federally threatened Nelson’s...

  11. ROE Wet Nitrate Deposition 1989-1991

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet nitrate deposition in kilograms per hectare from 1989 to 1991. Summary data in this indicator were provided by EPA’s...

  12. ROE Wet Sulfate Deposition 2009-2011

    Data.gov (United States)

    U.S. Environmental Protection Agency — The raster data represent the amount of wet sulfate deposition in kilograms per hectare from 2009 to 2011. Summary data in this indicator were provided by EPA’s...

  13. Wet Chemistry of Spinel Iron oxide Particles

    OpenAIRE

    Jolivet, J.; Chanéac, C.; Prené, P.; Vayssières, L.; Tronc, E.

    1997-01-01

    Various properties of spinel iron oxide nanograins are reviewed, illustrating the broad possibilities of wet chemistry for tailoring materials for a wide range of utilizations, from catalysis and sensors to cast magnetic materials.

  14. National Ignition Facility wet weather construction plan

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, A N

    1998-01-01

    This report presents a wet weather construction plan for the National Ignition Facility (NIF) construction project. Construction of the NIF commenced in mid- 1997, and excavation of the site was completed in the fall. Preparations for placing concrete foundations began in the fall, and above normal rainfall is expected over the tinter. Heavy rainfall in late November impacted foundation construction, and a wet weather construction plan was determined to be needed. This wet weather constiction plan recommends a strategy, techniques and management practices to prepare and protect the site corn wet weather effects and allow construction work to proceed. It is intended that information in this plan be incorporated in the Stormwater Pollution Prevention Plan (SWPPP) as warranted.

  15. Biodegradation of wet-white leather

    OpenAIRE

    Ollé Otero, Lluís; Jorba Rafart, Montse; Font Vallès, Joaquim; Shendrik, Alexander; Bacardit Dalmases, Anna

    2011-01-01

    This paper deals with the study of the physical, chemical and biological processes associated with the deterioration of wet-white leather. The samples of leather were exposed for eight months to outdoor weathering and then their properties were subsequently evaluated. The results indicate that resistance and dimensional stability of wet-white (THPS-syntan) leather is higher than that of chrometanned leather. The comparative work with chrome leather was described earlier.

  16. Curvature controlled wetting in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Mikheev, Lev V.

    1995-01-01

    A complete wetting transition at vanishing curvature of the substrate in two-dimensional circular geometry is studied by the transfer matrix method. We find an exact formal mapping of the partition function of the problem onto that of a (1+1)-dimensional wetting problem in planar geometry. As the...... term reduces the thickness by the amount proportional to r0-1/3...

  17. Fundamental Difficulties Associated With Underwater Wet Welding

    OpenAIRE

    Joshua E. Omajene,; Jukka Martikainen

    2014-01-01

    The offshore industries carry out welding activities in the wet environment. It is evident that the wet environments possess difficulties in carrying out underwater welding. Therefore there is the need to improve the quality of weld achieved in underwater welding. This paper investigates the difficulties associated with underwater welding. The objective of this research paper is to identify and analyze the different difficulties in underwater welding so as to make a clear back...

  18. Wetting and phase separation at surfaces

    Indian Academy of Sciences (India)

    Sanjay Puri; Kurt Binder

    2005-06-01

    We study the problem of surface-directed spinodal decomposition, viz., the dynamical interplay of wetting and phase separation at surfaces. In particular, we focus on the kinetics of wetting-layer growth in a semi-infinite geometry for arbitrary surface potentials and mixture compositions. We also present representative results for phase separation in confined geometries, e.g., cylindrical pores, thin films, etc.

  19. Complete wetting of graphene by biological lipids

    Science.gov (United States)

    Luan, Binquan; Huynh, Tien; Zhou, Ruhong

    2016-03-01

    Graphene nanosheets have been demonstrated to extract large amounts of lipid molecules directly out of the cell membrane of bacteria and thus cause serious damage to the cell's integrity. This interesting phenomenon, however, is so far not well understood theoretically. Here through extensive molecular dynamics simulations and theoretical analyses, we show that this phenomenon can be categorized as a complete wetting of graphene by membrane lipids in water. A wetting-based theory was utilized to associate the free energy change during the microscopic extraction of a lipid with the spreading parameter for the macroscopic wetting. With a customized thermodynamic cycle for detailed energetics, we show that the dispersive adhesion between graphene and lipids plays a dominant role during this extraction as manifested by the curved graphene. Our simulation results suggest that biological lipids can completely wet the concave, flat or even convex (with a small curvature) surface of a graphene sheet.Graphene nanosheets have been demonstrated to extract large amounts of lipid molecules directly out of the cell membrane of bacteria and thus cause serious damage to the cell's integrity. This interesting phenomenon, however, is so far not well understood theoretically. Here through extensive molecular dynamics simulations and theoretical analyses, we show that this phenomenon can be categorized as a complete wetting of graphene by membrane lipids in water. A wetting-based theory was utilized to associate the free energy change during the microscopic extraction of a lipid with the spreading parameter for the macroscopic wetting. With a customized thermodynamic cycle for detailed energetics, we show that the dispersive adhesion between graphene and lipids plays a dominant role during this extraction as manifested by the curved graphene. Our simulation results suggest that biological lipids can completely wet the concave, flat or even convex (with a small curvature) surface of a

  20. Estimating evaporation from a wet grassland

    OpenAIRE

    Gasca-Tucker, D. L.; Acreman, M. C.; Agnew, C. T.; Thompson, J R

    2007-01-01

    Wet grasslands are being restored across the UK and Europe to reinstate their high biodiversity following over 50 years of drainage and conversion to arable agriculture. The water balance of many wet grasslands is dominated by precipitation and evaporation and it is essential to quantify evaporation rates to understand the hydrological functioning of wetlands and the implications for water resources in catchments where wetlands are being restored. This paper considers data from direct measure...

  1. Avalanche Dynamics in Wet Granular Materials

    OpenAIRE

    Tegzes, P.; Vicsek, T.; P. Schiffer

    2002-01-01

    We have studied the dynamics of avalanching wet granular media in a rotating drum apparatus. Quantitative measurements of the flow velocity and the granular flux during avalanches allow us to characterize novel avalanche types unique to wet media. We also explore the details of viscoplastic flow (observed at the highest liquid contents) in which there are lasting contacts during flow, leading to coherence across the entire sample. This coherence leads to a velocity independent flow depth at h...

  2. ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM 2008

    Energy Technology Data Exchange (ETDEWEB)

    West, B.; Waltz, R.

    2009-06-11

    Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. Inspections made during 2008 to evaluate these vessels and other waste handling facilities along with evaluations based on data from previous inspections are the subject of this report.

  3. Blast wave protection of aqueous foams

    International Nuclear Information System (INIS)

    The primary intention of the present study is to present new contribution of shock tube tests to the problem of particle related stabilization and enhanced mitigation action of the wet particulate foams. The experiments reported were designed to examine (i) the reflection of a shock wave from an air/foam face, (ii) the transmission of the shock wave through the air/foam face and (iii) propagation and dispersion of the transmitted shock wave inside the foam column. Because wet aqueous foam of desired specification is difficult to reproduce, handle and quantitatively characterize the fact that experiments on all the above aspects were conducted in a single facility is a potentially important consideration. Moreover vertical position of shock tube simplified the issues since the gradient of the liquid fraction in draining foam coincides with the shock wave propagation. Under these, much simplified test conditions resulted flows could be treated as one-dimensional and the shock wave mitigation depends on three parameters: the intensity of the incident shock wave, s M , the duration of the foam decay, ∆t and on the particle concentration, n

  4. Aqueous polyethylene oxide solutions

    International Nuclear Information System (INIS)

    A number of aspects concerning the reorientation of polymer, water and ion hydration complexes have been studied in aqueous solution of polyethylene oxide (PEO). The polymer dynamics are investigated by 1H-PEO and 13C-PEO nuclear relaxation experiments. 162 refs.; 30 figs.; 19 tabs

  5. Dynamic Control of Nanopore Wetting in Water and Saline Solutions under an Electric Field.

    Science.gov (United States)

    Vanzo, Davide; Bratko, Dusan; Luzar, Alenka

    2015-07-23

    Field-induced nanopore wetting by aqueous solutions, including electrolytes, provides opportunities for a variety of applications. Conflicting porosity requirements have so far precluded direct implementations of a two-way control: the pores have to be sufficiently wide to allow water infiltration at experimentally relevant voltages but should not exceed the kinetic threshold for spontaneous expulsion in the absence of the field. Applicable widths are restricted below a few nanometers. Only a narrow window of fields and pore geometries can simultaneously satisfy both of the above requirements. Accurate accounts of wetting equilibria and dynamics at nanoscale porosity require molecular level descriptions. Here we use molecular dynamics simulations to study dynamic, field-controlled transitions between nanoconfined liquid and vapor phases in contact with an unperturbed aqueous or electrolyte environment. In nanopores wetted by electrolyte solutions, we observe depletion of salt compared to the bulk phase. The application of a local electric field enhances the uptake of water and ions in the confinement. In systems prone to capillary evaporation, the process can be reversed at sufficient strength of the electric field. For alternating displacement field, we identify the conditions where O (ns) responses of the reversible infiltration/expulsion cycle can be secured for experimentally realizable field strengths, porosity, and salinity of the solution. PMID:25184307

  6. Effects of wet cooling towers on weather and climate

    International Nuclear Information System (INIS)

    According to all the facts known until now, it may be stated that with the current cooling powers up to about 3,000 MW, the waste heat released through wet cooling towers results in no disadvantageous consequences for the environment. This is also valid for the concentration of several cooling towers of comparable size. Small changes of individual meteorological elements in the immediate neighborhood can no more be considered a hazard for the environment than negligible increases of temperature and rainfall in large cities and industrial agglomerations, known since a long time ago. It therefore seems justified to no longer consider the waste heat emission of large cooling towers set up in a flat, well ventilated terrain as an important part in the official licensing procedure and to carry out the time-consuming efficiency calculations only in individual cases or with especially unfavorable ground conditions. Climatic effects of a larger extent cannot be excluded if by application of higher cooling powers and concentration of groups of power stations the energy supply to the atmosphere occurs on larger areas and with higher vertical energy flows. Until now, the long-term effects on the regional climate which may arise as a consequence of the vapor release of a larger number of wet cooling plants by a change of the low-energy radiation conversion in the atmospheric boundary layer, cannot be assessed. By this mechanism lasting changes of the temperature level, the atmospheric stratifications, and the cloud climatology will be possible by means of variations of the conditions of insulation and emission of radiation. (orig./HP)

  7. Bitumen immobilization of aqueous radwaste by thin-film evaporation

    International Nuclear Information System (INIS)

    In the early 1980s, AECL built a Waste Treatment Centre (WTC) for managing low-level solid and aqueous liquid wastes for converting CANDU wastes. At present, two liquid waste streams are being treated at the WTC. The liquid waste streams are volume-reduced by a combination of continuous crossflow microfiltration (MF), spiral wound reverse osmosis (SWRO) and tubular reverse osmosis (TRO) membrane technologies. The concentrate produced from the TRO system and the volume-reduced MF backwash solutions are evaporated while simultaneously adding bitumen in a thin-film evaporator. A water-free product of chemical and radiochemical salts and bitumen is removed in 200-L galvanized steel drums for storage. The radiation field of product drums on contact typically has a value of 0.5 to 3 R/h depending upon the feed concentration of radioactivity to the evaporator. The total solids content in the 200-L drum ranges from 25 to 35%. Encapsulated in the bitumen matrix are a variety of nonradiochemical salts, which comprise the bulk of the total solids that are in the product drum. This report discusses the immobilization of the aqueous waste with bitumen in a thin-film evaporator. Simulated bituminized waste forms were leached in accordance with the ANS/ANSI 16.1 leach test. In this test, the waste form is immersed under water for an extended period of time, and the leachate is periodically removed and chemically analysed. The Leachability index varied between 7 and 9 for the emulsified bitumen waste forms produced at the WTC. Bitumen samples were unconfined and subjected to immersion and frequent leachate replenishment. The results of leach tests will be a lower bound for the performance of the bitumen waste product in an unsaturated environment. The Leachability indexes reported exceeds the USNRC minimum requirement for wasteform criteria. Adding protective overcoats of either Portland cement or oxidized bitumen enhanced the Leachability index. 8 refs., 3 tabs., 6 figs

  8. Waste Receiving and Processing (WRAP) Facility technology

    International Nuclear Information System (INIS)

    Waste treatment capabilities for Waste Receiving and Processing (WRAP) Facility Module 1 (WRAP-1) will be limited to opening and repackaging of suspect transuranic (TRU) drums and the necessary nondestructive examination (NDE) and nondestructive assay (NDA) services for shipment of the certified waste packages to the designated disposal facilities. The technologies used in WRAP Module 2 (WRAP-2) are principally those waste treatment methodologies necessary to ensure the final waste forms are in compliance with disposal and/or transportation criteria. The WRAP-2 will treat all TRU noncompliant waste items that do not meet the WIPP Waste Acceptance Criteria (WAC) segregated in WRAP-1, all the Hanford Site radioactive/hazardous low-level mixed waste (LLMW), all large items requiring size reduction/sorting/treatment needed for disposal (mostly large suspect TRU waste items), and remote-handled (high surface dose) waste items. The current scope of the WRAP-2 Facility will employ the following waste treatment technologies: passivation of the waste by chemical additives, waste immobilization (within grout matrixes), size reduction via shears/mechanical saws/plasma arc torches/lasers, compaction, shred/grouting, plasma melting, and wet chemical decontamination techniques. All waste materials will be certified to meet the appropriate US Department of Energy (DOE) orders for waste characterization and will adhere to the Resource Conservation and Recovery Act (RCRA) regulations in compliance with the promulgated treatment standards. 3 figs

  9. Vermi composting--organic waste management and disposal.

    Science.gov (United States)

    Kumar, J Sudhir; Subbaiah, K Venkata; Rao, P V V Prasada

    2012-01-01

    Solid waste is an unwanted byproduct of modern civilization. Landfills are the most common means of solid waste disposal. But the increasing amount of solid waste is rapidly filling existing landfills, and new sites are difficult to establish. Alternatives to landfills include the use of source reduction, recycling, composting and incineration, as well as use of landfills. Incineration is most economical if it includes energy recovery from the waste. Energy can be recovered directly from waste by incineration or the waste can be processed to produce storable refuse derived fuel (RDF). Information on the composition of solid wastes is important in evaluating alternative equipment needs, systems, management programs and plans. Pulverization of municipal solid waste is done and the pulverized solid waste is dressed to form a bed and the bed is fed by earthworms which convert the bed into vermi compost. The obtained vermi compost is sent to Ministry of Environment & Forests (MoEF) recognized lab for estimating the major nutrients, i.e. Potassium (K), Phosphorous (P), Nitrogen (N) and Micro-nutrient values. It is estimated that 59 - 65 tons of wet waste can be collected in a town per day and if this wet waste is converted to quality compost, around 12.30 tons of vermi compost can be generated. If a Municipal Corporation manages this wet waste an income of over (see text symbol) for 0.8 9 crore per anum can be earned which is a considerable amount for providing of better services to public. PMID:23741869

  10. Advantages of dry hardened cask storage over wet storage for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Romanato, Luiz Sergio, E-mail: romanato@ctmsp.mar.mil.b [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sao Paulo, SP (Brazil). Dept. da Qualidade

    2011-07-01

    Pools are generally used to store and maintain spent nuclear fuel assemblies for cooling, after removed from reactors. After three to five years stored in the pools, spent fuel can be reprocessed or sent to a final disposition in a geological repository and handled as radioactive waste or sent to another site waiting for future solution. Spent fuel can be stored in dry or wet installations, depending on the method adopted by the nuclear plant. If this storage were exclusively wet, at the installation decommissioning in the future, another solution for storage will need to be found. Today, after a preliminary cooling, the spent fuel assemblies can be removed from the pool and sent to dry hardened storage installations. This kind of storage does not need complex radiation monitoring and it is safer than wet storage. Brazil has two nuclear reactors in operation, a third reactor is under construction and they use wet spent fuel storage . Dry hardened casks use metal or both metal and concrete for radiation shielding and they are safe, especially during an earthquake. An earthquake struck Japan on March 11, 2011 damaging Fukushima Daiichi nuclear power plant. The occurrence of earthquakes in Brazil is very small but dry casks can resist to other events, including terrorist acts, better than pools. This paper shows the advantages of dry hardened cask storage in comparison with the wet storage (water pools) for spent nuclear fuel. (author)

  11. Environmental simulation test for radionuclide migration under wet-dry cycle condition in aerated zone

    International Nuclear Information System (INIS)

    Influence of discontinuous water flow based on repeated cycle of rainfall and evaporation (wet-dry cycle condition) on the migration behavior of 60Co, 85Sr and 137Cs in a sandy soil layer has been demonstratively investigated by using the equipment of environmental simulation test for radionuclide migration, in order to establish a reliable evaluation method of the radionuclide migration in natural barrier, in relation to the safety assessment on shallow land disposal of low-level radioactive waste. Migration velocity of cationic 85Sr, concentrations of particulate 60Co and 137Cs in the deeper soil layer, pH and ion concentration dissolved in the soil layer under the wet-dry cycle condition became larger than those under the continuous flow condition. Increase of the migration velocity of cationic 85Sr under the wet-dry cycle condition was attributed to that the concentration of Ca2+, by which the sorption ability of 85Sr onto soils was reduced, increased in interstitial water during an interruption period of water flow. On the other hand, the migration velocity of cationic 60Co and 137Cs was not affected by the wet-dry cycle condition. Increase of the concentration of particulate 60Co and 137Cs under the wet-dry cycle condition was probably caused from that movable {60Co(OH)2}n and 137Cs fixed on fine soil particles were produced during the interruption period. (author)

  12. Wastes options

    International Nuclear Information System (INIS)

    After a description of the EEC environmental policy, some wastes families are described: bio-contaminant wastes (municipal and industrial), hospitals wastes, toxic wastes in dispersed quantities, nuclear wastes (radioactive and thermal), plastics compounds wastes, volatiles organic compounds, hydrocarbons and used solvents. Sources, quantities and treatments are given. (A.B.). refs., figs., tabs

  13. On the gasification of wet biomass in supercritical water : over de vergassing van natte biomassa in superkritiek water

    NARCIS (Netherlands)

    Withag, J.A.M.

    2013-01-01

    Supercritical water gasification (SCWG) is a challenging thermo-chemical conversion route for wet biomass and waste streams into hydrogen and/or methane. At temperatures and pressures above the critical point the physical properties of water differ strongly from liquid water or steam. Because of the

  14. Aqueous chemistry of iodine

    International Nuclear Information System (INIS)

    The chemistry of iodine has been examined in aqueous solutions of pH 6 to 10 containing 2500 ppM boron as H3BO3 at temperatures up to 1500C using absorption spectrophotometry to identify and monitor the iodine species present. Kinetic rate constants for the disproportionation of the HOI intermediate, 3HOI= IO3- + 2I- + 3H+, have been measured as a function of pH even though no direct spectral evidence for HOI itself has been observed. An HOI partition coefficient >104 has been estimated; results of ionic strength tests are consistent with HOI being present as an uncharged triatomic species in solution. Redox and radiation effects on the aqueous iodine chemistry have also been described. 11 refs., 2 figs., 3 tabs

  15. Can I Stop Myself From Having a Wet Dream?

    Science.gov (United States)

    ... Can I Stop Myself From Having a Wet Dream? KidsHealth > For Teens > Can I Stop Myself From Having a Wet Dream? Print A A A Text Size Can I stop myself from having a wet dream? – Tom* You really can't stop wet dreams, ...

  16. Energy and heat balance in wet DCT

    Energy Technology Data Exchange (ETDEWEB)

    Saxena, Viren; Moser, Alexander; Schaefer, Michael; Ritschel, Michael [BorgWarner Drivetrain Engineering GmbH, Ketsch (Germany)

    2012-11-01

    Wet clutch systems are well known for their thermal robustness and versatility in a wide range of automotive applications. Conventional automatics have used them for a long time as torque converter lock-up clutches, shift elements and launch clutches. With the development of DCTs, wet clutch technology has evolved in terms of launch and shift performance, controllability, robustness and efficiency. This paper discusses improvements in the wet clutch and their impact on today's vehicle applications in terms of heat and energy management. Thermal robustness is a crucial aspect for an automatic transmission. In addition to the clutch thermal performance, the influence of transmission oil cooler and oil sump warm-up behavior are discussed. Based on our latest development activities, test results and simulations, we shall discuss the latest friction material enhancement and its impact on DCTs in terms of efficiency and performance. Drag loss is a much-discussed topic during the development of wet clutch systems. This paper discusses in detail the cause and break-up of various energy losses in a wet DCT. Efficient energy management strategies for actuation systems, cooling, and lubrication, clutch apply, and pre-selection in modern power trains with engine start / stop are evaluated based on the latest test and simulation results. Finally, the paper summarizes the performance and efficiency optimized moist clutch system. (orig.)

  17. Design consideration for wet welded joints

    Energy Technology Data Exchange (ETDEWEB)

    Szelagowski, P.; Osthus, V. [GKSS Research Center, Geesthacht (Germany); Petershagen, H.; Pohl, R. [Univ. Hamburg (Germany). Inst. fuer Schiffbau; Lafaye, G. [Stolt Comex Seaway S.A., Marseille (France)

    1996-12-01

    Wet welding has become a joining technique that under certain circumstances can provide results which cannot be distinguished between wet or dry production and the achievable mechanical quality is comparable to dry atmospheric welds. Wet welding is not a process which can be applied easily and which can be properly handled by untrained diver welders. Wet welding is more than any other kind of welding process or procedure a joining technique that requires the full job-concentration and -knowledge of an excellent trained and skilled diver welder throughout the whole production time, who is 100% identifying himself with his task. Furthermore he must be fully aware of the production requirements and possible metallurgical/environmental reactions and outcomes. He must be able to be fully concentrated on the process performance throughout his total work shift. In short: he must be an outstanding expert in his field. The following paper will highlight these subjects and show the necessity of their exact observation to achieve excellent quality in wet welding.

  18. Hazardous waste status of discarded electronic cigarettes

    Energy Technology Data Exchange (ETDEWEB)

    Krause, Max J.; Townsend, Timothy G., E-mail: ttown@ufl.edu

    2015-05-15

    Highlights: • Electronic cigarettes were tested using TCLP and WET. • Several electronic cigarette products leached lead at hazardous waste levels. • Lead was the only element that exceeded hazardous waste concentration thresholds. • Nicotine solution may cause hazardous waste classification when discarded unused. - Abstract: The potential for disposable electronic cigarettes (e-cigarettes) to be classified as hazardous waste was investigated. The Toxicity Characteristic Leaching Procedure (TCLP) was performed on 23 disposable e-cigarettes in a preliminary survey of metal leaching. Based on these results, four e-cigarette products were selected for replicate analysis by TCLP and the California Waste Extraction Test (WET). Lead was measured in leachate as high as 50 mg/L by WET and 40 mg/L by TCLP. Regulatory thresholds were exceeded by two of 15 products tested in total. Therefore, some e-cigarettes would be toxicity characteristic (TC) hazardous waste but a majority would not. When disposed in the unused form, e-cigarettes containing nicotine juice would be commercial chemical products (CCP) and would, in the United States (US), be considered a listed hazardous waste (P075). While household waste is exempt from hazardous waste regulation, there are many instances in which such waste would be subject to regulation. Manufactures and retailers with unused or expired e-cigarettes or nicotine juice solution would be required to manage these as hazardous waste upon disposal. Current regulations and policies regarding the availability of nicotine-containing e-cigarettes worldwide were reviewed. Despite their small size, disposable e-cigarettes are consumed and discarded much more quickly than typical electronics, which may become a growing concern for waste managers.

  19. Hazardous waste status of discarded electronic cigarettes

    International Nuclear Information System (INIS)

    Highlights: • Electronic cigarettes were tested using TCLP and WET. • Several electronic cigarette products leached lead at hazardous waste levels. • Lead was the only element that exceeded hazardous waste concentration thresholds. • Nicotine solution may cause hazardous waste classification when discarded unused. - Abstract: The potential for disposable electronic cigarettes (e-cigarettes) to be classified as hazardous waste was investigated. The Toxicity Characteristic Leaching Procedure (TCLP) was performed on 23 disposable e-cigarettes in a preliminary survey of metal leaching. Based on these results, four e-cigarette products were selected for replicate analysis by TCLP and the California Waste Extraction Test (WET). Lead was measured in leachate as high as 50 mg/L by WET and 40 mg/L by TCLP. Regulatory thresholds were exceeded by two of 15 products tested in total. Therefore, some e-cigarettes would be toxicity characteristic (TC) hazardous waste but a majority would not. When disposed in the unused form, e-cigarettes containing nicotine juice would be commercial chemical products (CCP) and would, in the United States (US), be considered a listed hazardous waste (P075). While household waste is exempt from hazardous waste regulation, there are many instances in which such waste would be subject to regulation. Manufactures and retailers with unused or expired e-cigarettes or nicotine juice solution would be required to manage these as hazardous waste upon disposal. Current regulations and policies regarding the availability of nicotine-containing e-cigarettes worldwide were reviewed. Despite their small size, disposable e-cigarettes are consumed and discarded much more quickly than typical electronics, which may become a growing concern for waste managers

  20. V6O13 films by control of the oxidation state from aqueous precursor to crystalline phase

    OpenAIRE

    PEYS, Nick; Ling, Yun; DEWULF, Daan; Gielis, Sven; DE DOBBELAERE, Christopher; Cuypers, Daniel; Adriaensens, Peter; Van Doorslaer, Sabine; De Gendt, Stefan; Hardy, An; Van Bael, Marlies

    2013-01-01

    An aqueous deposition process for V6O13 films is developed whereby the vanadium oxidation state is continuously controlled throughout the entire process. In the precursor stage, a controlled wet chemical reduction of the vanadium(V) source with oxalic acid is achieved and monitored by (51)Vanadium Nuclear Magnetic Resonance (V-51-NMR) and Ultraviolet-Visible (UV-Vis) spectroscopy. The resulting vanadium(IV) species in the aqueous solution are identified as mononuclear citrato-oxovanadate(IV) ...

  1. Evaporation from rain-wetted forest in relation to canopy wetness, canopy cover, and net radiation

    NARCIS (Netherlands)

    Klaassen, W.

    2001-01-01

    Evaporation from wet canopies is commonly calculated using E-PM, the Penman-Monteith equation with zero surface resistance. However, several observations show a lower evaporation from rain-wetted forest. Possible causes for the difference between E-PM and experiments are evaluated to provide rules f

  2. Activation of aluminum as an effective reducing agent by pitting corrosion for wet-chemical synthesis.

    Science.gov (United States)

    Li, Wei; Cochell, Thomas; Manthiram, Arumugam

    2013-01-01

    Metallic aluminum (Al) is of interest as a reducing agent because of its low standard reduction potential. However, its surface is invariably covered with a dense aluminum oxide film, which prevents its effective use as a reducing agent in wet-chemical synthesis. Pitting corrosion, known as an undesired reaction destroying Al and is enhanced by anions such as F⁻, Cl⁻, and Br⁻ in aqueous solutions, is applied here for the first time to activate Al as a reducing agent for wet-chemical synthesis of a diverse array of metals and alloys. Specifically, we demonstrate the synthesis of highly dispersed palladium nanoparticles on carbon black with stabilizers and the intermetallic Cu₂Sb/C, which are promising candidates, respectively, for fuel cell catalysts and lithium-ion battery anodes. Atomic hydrogen, an intermediate during the pitting corrosion of Al in protonic solvents (e.g., water and ethylene glycol), is validated as the actual reducing agent. PMID:23390579

  3. The Edge of Wetness: The Case for Dry Magmatism on Mars

    Science.gov (United States)

    Jones, J. H.

    2004-01-01

    The issue of whether martian magmas are wet or dry is an important one. The answer to this basic question has profound consequences for how we think about Mars as a planet. Recently, several lines of evidence have been presented that collectively suggest that shergottite parent magmas were once wet. These include: (i) phase equilibria studies that indicate that the Shergotty parent magma required 2 wt.% water in order to be co-saturated with both pigeonite and augite, (ii) reverse zoning of light lithophile elements (Li and B) in shergottite pyroxenes, suggesting the exsolution and removal of an aqueous fluid, and (iii) measurement of D/H ratios in SNC minerals that are much lower than atmospheric, suggesting that there may be juvenile (primordial) mantle water. Below I will review the evidence for the diametrically opposite case, that shergottite magmas were effectively dry (<< 1 wt.% H2O).

  4. Adsorption isotherms, kinetics and column operations for the removal of hazardous dye, Tartrazine from aqueous solutions using waste materials-Bottom Ash and De-Oiled Soya, as adsorbents

    International Nuclear Information System (INIS)

    Adsorbents, Bottom Ash (a power plant waste) and De-Oiled Soya (an agricultural waste) exhibit good efficacy to adsorb a highly toxic dye, Tartrazine. Through the batch technique equilibrium uptake of the dye is observed at different concentrations, pH of the solution, dosage of adsorbents and sieve size of adsorbents. Langmuir and Freundlich adsorption isotherms are successfully employed on both the adsorbents and on the basis of these models the thermodynamic parameters are evaluated. Kinetic investigations reveal that more than 50% adsorption of dye is achieved in about 1 h in both the cases, whereas, equilibrium establishment takes about 3-4 h. The linear plots obtained in rate constant and mass transfer studies further confirm the applicability of first order rate expression and mass transfer model, respectively. The kinetic data treated to identify rate controlling step of the ongoing adsorption processes indicate that for both the systems, particle diffusion process is predominant at higher concentrations, while film diffusion takes place at lower concentrations. The column studies reveal that about 96% saturation of both the columns is attained during their exhaustion, while about 88 and 84% of the dye material is recovered by eluting dilute NaOH solution through exhausted Bottom Ash and De-Oiled Soya columns, respectively

  5. Enhanced NOx removal in wet FGD systems

    International Nuclear Information System (INIS)

    The dominant method for high-efficiency NOx removal is ammonia-based selective catalytic reduction (SCR). However, no full-scale, commercial SCR process exists for coal-fired power plants in North America. This paper describes wet flue gas desulphurization (FGD), the leading control technology for sulphur dioxide emissions from coal-fired power plants. The feasibility of using wet FGD systems for simultaneous NOx and SO2 removal was studied in a mini-pilot scale perforated tray absorber by varying the NO to NO2 ratio in the inlet gas. It was shown that the presence of sulphite ions in stoichiometric excess in the liquid phase had a significant positive effect on the absorption of NOx in wet FGD systems. The pH of the absorbing solution was also found to have a major effect on NOx removal efficiency. 49 refs., 6 tabs., 14 figs

  6. NANOFILLERS FOR PAPERMAKING WET END APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Jing Shen

    2010-05-01

    Full Text Available The papermaking industry can benefit a lot from nanotechnology. This versatile technology can also be used in the area of fillers for papermaking wet end applications. In such applications the main technological examples currently available include wet end addition of commercially available nanofillers, formation of nanofiller/fiber or nanofiller/fibril hybrids, development of novel categories of nanofillers such as high aspect ratio nanofillers, and combination of microfillers with nanostructures by specially controlled routes to obtain composite nanofillers. It is worth noting that there are certain challenges associated with nanofillers, such as high cost, difficulty in structure and performance control, poor dispersability and retention, possible severe negative effects on paper strength, possible detrimental interactions between nanofillers with some wet end additives, and the industry-related limitations. However, in the long run, the research and development in the area of nanofillers will surely create many fruitful results.

  7. Molecular Dynamics Simulations for Predicting Surface Wetting

    Directory of Open Access Journals (Sweden)

    Jing Chen

    2014-06-01

    Full Text Available The investigation of wetting of a solid surface by a liquid provides important insights; the contact angle of a liquid droplet on a surface provides a quantitative measurement of this interaction and the degree of attraction or repulsion of that liquid type by the solid surface. Molecular dynamics (MD simulations are a useful way to examine the behavior of liquids on solid surfaces on a nanometer scale. Thus, we surveyed the state of this field, beginning with the fundamentals of wetting calculations to an examination of the different MD methodologies used. We highlighted some of the advantages and disadvantages of the simulations, and look to the future of computer modeling to understand wetting and other liquid-solid interaction phenomena.

  8. Handling of wet residues in industry

    DEFF Research Database (Denmark)

    Villanueva, Alejandro

    operational tools geared to assist industries in the selection of disposal routes for wet residues. The target group of the study are the wet residue producing companies. The study is structured in the form of a handbook, with the aim of making it simpler and faster for industries to find their way to...... feasible considering also economic and environmental criteria. It has been found that the advantages and disadvantages of a given disposal option, as a basis for decision-making, can be analysed using five assessment criteria:  legislation  technology  economy  environment  society concerns These five...... characterise the technical options, the costs, and the legal, environmental and social implications of residue disposal. The handbook contains a series of decision-support tools that enables a company to select a solution. In this way, wet residue handling can be tackled at an early phase of project design...

  9. Aqueous phase processing of secondary organic aerosol from isoprene photooxidation

    Directory of Open Access Journals (Sweden)

    Y. Liu

    2012-07-01

    Full Text Available Transport of reactive air masses into humid and wet areas is highly frequent in the atmosphere, making the study of aqueous phase processing of secondary organic aerosol (SOA very relevant. We have investigated the aqueous phase processing of SOA generated from gas-phase photooxidation of isoprene using a smog chamber. The SOA collected on filters was extracted by water and subsequently oxidized in the aqueous phase either by H2O2 under dark conditions or by OH radicals in the presence of light, using a photochemical reactor. Online and offline analytical techniques including SMPS, HR-AMS, H-TDMA, TD-API-AMS, were employed for physical and chemical characterization of the chamber SOA and nebulized filter extracts. After aqueous phase processing, the particles were significantly more hygroscopic, and HR-AMS data showed higher signal intensity at m/z 44 and a lower signal intensity at m/z 43, thus showing the impact of aqueous phase processing on SOA aging, in good agreement with a few previous studies. Additional offline measurement techniques (IC-MS, APCI-MS2 and HPLC-APCI-MS permitted the identification and quantification of sixteen individual chemical compounds before and after aqueous phase processing. Among these compounds, small organic acids (including formic, glyoxylic, glycolic, butyric, oxalic and 2,3-dihydroxymethacrylic acid (i.e. 2-methylglyceric acid were detected, and their concentrations significantly increased after aqueous phase processing. In particular, the aqueous phase formation of 2-methylglyceric acid and trihydroxy-3-methylbutanal was correlated with the consumption of 2,3-dihydroxy-2-methyl-propanal, and 2-methylbutane-1,2,3,4-tetrol, respectively, and an aqueous phase mechanism was proposed accordingly. Overall, the aging effect observed here was rather small compared to previous studies, and this limited effect could possibly be explained by the lower liquid phase OH

  10. Corrosion inhibition of magnesium heated in wet air, by surface fluoridation

    International Nuclear Information System (INIS)

    The maximum temperature (350 deg. C) of magnesium corrosion resistance in wet air may be raised to 490-500 deg. C by the formation of a superficial fluoride film. This can be obtained by two different ways: either by addition of hydrofluoric acid to the corroding medium in a very small proportion such as 0,003 mg/litre; at atmospheric pressure, or by dipping the magnesium in a dilute aqueous solution of nitric and hydrofluoric acids at room temperature before exposing it to the corroding atmosphere. In both cases the corrosion inhibition is effective over a very long time, even several thousand hours. (author)

  11. Equilibrating nanoparticle monolayers using wetting films.

    Science.gov (United States)

    Pontoni, Diego; Alvine, Kyle J; Checco, Antonio; Gang, Oleg; Ocko, Benjamin M; Pershan, Peter S

    2009-01-01

    Monolayers of bimodal gold nanoparticles on silicon are investigated by a combination of microscopy (dry monolayers) and x-ray diffraction (dry and wet monolayers). In the presence of an excess of small particles, the nanoscale packing structure closely resembles the small-particle-rich scenario of the structural crossover transition that has been predicted and also observed with micron-scale hard-sphere colloids. Structural morphology is monitored in situ during monolayer dissolution and reassembly within the thin liquid wetting film. This approach allows investigation of size and solvent effects on nanoparticles in quasi-two-dimensional confinement. PMID:19257214

  12. Sphere impact and penetration into wet sand

    KAUST Repository

    Marston, J. O.

    2012-08-07

    We present experimental results for the penetration of a solid sphere when released onto wet sand. We show, by measuring the final penetration depth, that the cohesion induced by the water can result in either a deeper or shallower penetration for a given release height compared to dry granular material. Thus the presence of water can either lubricate or stiffen the granular material. By assuming the shear rate is proportional to the impact velocity and using the depth-averaged stopping force in calculating the shear stress, we derive effective viscosities for the wet granular materials.

  13. Solid waste

    International Nuclear Information System (INIS)

    The article drawn up within the framework of 'the assessment of the state of the environment in Lebanon' provides an overview of solid waste management, and assesses future wastes volume and waste disposal issues.In particular it addresses the following concerns: - Long term projections of solid waste arisings (i.e. domestic, industrial, such commercial wastes, vehicle types, construction waste, waste oils, hazardous toxic wastes and finally hospital and clinical wastes) are described. - Appropriate disposal routes, and strategies for reducing volumes for final disposal - Balance between municipal and industrial solid waste generation and disposal/treatment and - environmental impacts (aesthetics, human health, natural environment )of existing dumps, and the potential impact of government plans for construction of solid waste facilities). Possible policies for institutional reform within the waste management sector are proposed. Tables provides estimations of generation rates and distribution of wastes in different regions of Lebanon. Laws related to solid waste management are summarized

  14. Procedure to use phosphogypsum industrial waste for mineral CO{sub 2} sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas-Escudero, C. [Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Seville (Spain); Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Av. Americo Vespucio, 49, 41092 Seville (Spain); Morales-Florez, V., E-mail: victor.morales@icmse.csic.es [Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Av. Americo Vespucio, 49, 41092 Seville (Spain); Perez-Lopez, R. [Departamento de Geologia, Facultad de Ciencias Experimentales, Universidad de Huelva, Campus Universitario Campus del Carmen, Avenida de las Fuerzas Armadas, 21071 Huelva (Spain); Instituto de Diagnostico Ambiental y Estudios del Agua (IDAeA-CSIC), Jordi Girona 18, 08034 Barcelona (Spain); Santos, A. [Departamento de Ciencias de la Tierra, Universidad de Cadiz, Campus del Rio San Pedro, Av. Republica Saharaui s/n, 11510 Puerto Real (Spain); Esquivias, L. [Departamento de Fisica de la Materia Condensada, Facultad de Fisica, Universidad de Sevilla, Av. Reina Mercedes s/n, 41012 Seville (Spain); Instituto de Ciencia de Materiales de Sevilla (CSIC-US), Av. Americo Vespucio, 49, 41092 Seville (Spain)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer Phosphogypsum wastes are proposed to reduce CO{sub 2} greenhouse gas emissions. Black-Right-Pointing-Pointer Phosphogypsum dissolution with NaOH results in Ca(OH){sub 2} precipitation and Na{sub 2}SO{sub 4}. Black-Right-Pointing-Pointer Aqueous carbonation of Ca(OH){sub 2} with CO{sub 2} results in the CaCO{sub 3} precipitation. Black-Right-Pointing-Pointer Metals contained in the phosphogypsum are transferred to the final calcite. Black-Right-Pointing-Pointer Applications of CaCO{sub 3} and Na{sub 2}SiO{sub 4} by-products are proposed to improve viability. - Abstract: Industrial wet phosphoric acid production in Huelva (SW Spain) has led to the controversial stockpiling of waste phosphogypsum by-products, resulting in the release of significant quantities of toxic impurities in salt marshes in the Tinto river estuary. In the framework of the fight against global climate change and the effort to reduce carbon dioxide emissions, a simple and efficient procedure for CO{sub 2} mineral sequestration is presented in this work, using phosphogypsum waste as a calcium source. Our results demonstrate the high efficiency of portlandite precipitation by phosphogypsum dissolution using an alkaline soda solution. Carbonation experiments performed at ambient pressure and temperature resulted in total conversion of the portlandite into carbonate. The fate of trace elements present in the phosphogypsum waste was also investigated, and trace impurities were found to be completely transferred to the final calcite. We believe that the procedure proposed here should be considered not only as a solution for reducing old stockpiles of phosphogypsum wastes, but also for future phosphoric acid and other gypsum-producing industrial processes, resulting in more sustainable production.

  15. Phytochemical Screening and Antibacterial Activity of Globimetulla browni Extracts During Wet Season

    Directory of Open Access Journals (Sweden)

    H.M. Inuwa

    2012-02-01

    Full Text Available The study investigated the phytochemical composition of Globimetulla browni for it’s ascribed folkloric medicinal uses as an antidiabetic and to establish its Antibacterial potency (if any. A comparative investigation was carried out and season did not have any effect on the phytochemical/Antibacterial potency of this plant. The ethanolic and aqueous extracts significantly affected both gram-negative and gram- positive microorganisms during wet season (May - September. Globimetulla browni is a specie of African mistletoe and is hemi-parasitic in nature growing on many trees e.g., Eukalyptus and has ascribed medicinal uses. Phytochemical screening showed the presence of carbohydrates, alkaloids, tannins and flavonoids. The ethanolic and aqueous extracts inhibited the growth of Klebsiella aerogenes, Proteus spp., Escherichia coli and Pseudomonas aeruginosa. Gentamycin and Cloxacillin did not exhibit any activity against Pseudomonas aeruginosa.

  16. Time-resolved luminescence spectroscopy of trace uranyl in wet sand

    International Nuclear Information System (INIS)

    The objective of the project was to develop a technique to observe and characterize the behaviour of uranium in unsaturated groundwater flow systems, particularly with regard to unstable ''fingered'' flow, which could drastically reduce time of travel. The actual experimental work described was a study of the feasibility of detecting uranyl at the parts-per-billion level in aqueous solution by means of its luminescence spectrum. A high-power UV laser was used to excite aqueous uranyl in a wet sand mixture; the characteristic green phosphorescence emitted in the decay transition was detected by a photomultiplier tube; and the amplified signal was sent to an oscilloscope in communication with Macintosh data acquisition software. At the time of the conference, a more sophisticated sample configuration for imaging the flow of uranyl was already under development. 5 refs., 3 figs

  17. Surfactant controlled switching of water-in-oil wetting behaviour of porous silica films grown at oil-water interfaces

    Indian Academy of Sciences (India)

    Manish M Kulkarni; Rajdip Bandyopadhyaya; Ashutosh Sharma

    2008-11-01

    Selective permeation of oil and water across a porous medium, as in oil recovery operations, depends on the preferential wetting properties of the porous medium. We show a profound influence of surfactants in wetting of porous media and thus demonstrate a new route for the control of water-in-oil wetting of porous substrates by changing the concentration of surfactants in an aqueous sub-phase below the substrate. This strategy is employed to engineer partial reversible wetting transitions on a porous silica film. The film itself is grown and stabilized on a flat, macroscopic interface between an oil phase and an aqueous sub-phase. On increasing the surfactant (CTAB) concentration in the sub-phase, contact angle of a water drop (placed on the oil side of the film) changes from 140° to 16° in 25 min by diffusion of the surfactant across the porous film. On further replacement of the sub-phase with pure water, diffusion of the surfactant from the water drop back to the sub-phase was slower, increasing the contact angle in the process from 16° to 90° in 2 h. Wettability control by a cationic surfactant (CTAB) was found to be much faster (6 deg/min) than that offered by an anionic surfactant, SDS (0.05 deg/min). Switching of the surface wettability due to the surfactant diffusion may have implications in oil-water separation, chemical bed reactors and microfluidic devices.

  18. Waste management

    OpenAIRE

    Knopová Policarová, Táňa

    2014-01-01

    Diploma thesis deals with waste disposal in the Czech Republic, including waste production and waste recovery. The aim of this work is to characterize and evaluate the waste production, sorting a disposal in the Czech Republic. Theoretical basis of diploma thesis are focused on basic concepts of waste management legislation, the generation of waste and how to prevent the formation or at least reduce it. The greatest attention is paid to waste disposal, in which there are presented and analyze...

  19. Bis-diglycol-amides (Bis-DGA) as new extractants for An(III) and Ln(III) from aqueous high-level wastes issued from the Purex process

    International Nuclear Information System (INIS)

    A new family of compounds with two diglycolamide moieties in their molecule have been synthesized and studied as suitable extractants for trivalent actinides (An(III)) and trivalent lanthanides (Ln(III)) present in high-level wastes (HLW) issued from the PUREX process. Although the obtained distribution ratios are comparable with those from TODGA under similar experimental conditions, the bis-DGA compounds showed higher selectivity towards Ln(III). The number of bis-DGA molecules involved in the formation of the dominant complex is two, and it is possible to recover more than 99% of the extracted An and Ln with 0.01 M nitric acid in order to recycle the solvent in subsequent extraction cycles. (authors)

  20. Utilization of event precipitation data to establish source-receptor relationships for mercury wet deposited in south Florida

    Science.gov (United States)

    Dvonch, Joseph Timothy

    Source-receptor relationships for mercury (Hg) and other trace elements wet-deposited in south Florida were investigated using daily-event precipitation samples collected concurrently at 17 sites from 8/6/95 to 9/6/95. Local anthropogenic sources were found to account for all of the Hg wet-deposited during the study period at measurement sites in the Florida Everglades. Meteorological analyses of precipitation cell path history utilizing WSR-88D radar data found significantly higher volume-weighted mean (VWM) concentrations of Hg in precipitation with easterly cell paths (26 ng/l, from the local urban source area) than those with westerly paths (13 ng/l, from the Everglades) for storms arriving at Everglades sites. This also coincided with significantly higher VWM concentrations of the known anthropogenic elements V and Ni (oil combustion), and Pb and Sb (waste incineration). A multivariate receptor modeling approach found municipal waste incineration and oil combustion sources to account for 71% ± 8% of the Hg wet-deposited during the study at five sites in the Everglades. Similarly, analysis of additional event precipitation samples collected over a one-year period (6/22/95 to 6/21/96) at a site in Davie, FL found 73% ± 6% of the Hg wet-deposited at this site over the entire one-year period to be accounted for by local anthropogenic sources. Receptor modeling results closely agreed with the stack measurements made at local point sources during the study, as well as with the Florida Hg emissions inventory compiled by USEPA. An emissions reconciliation found local medical waste incineration sources to account for 30% ± 16% of Hg wet deposition at the Everglades sites. Therefore, 100% ± 18% of the Hg wet-deposited at these sites could be accounted for by the combined local emissions of medical waste incineration, municipal waste incineration, and oil combustion sources. Finally, it was calculated that locally emitted anthropogenic Hg, which was measured during

  1. Waste Treatment Technology Process Development Plan For Hanford Waste Treatment Plant Low Activity Waste Recycle

    International Nuclear Information System (INIS)

    The purpose of this Process Development Plan is to summarize the objectives and plans for the technology development activities for an alternative path for disposition of the recycle stream that will be generated in the Hanford Waste Treatment Plant Low Activity Waste (LAW) vitrification facility (LAW Recycle). This plan covers the first phase of the development activities. The baseline plan for disposition of this stream is to recycle it to the WTP Pretreatment Facility, where it will be concentrated by evaporation and returned to the LAW vitrification facility. Because this stream contains components that are volatile at melter temperatures and are also problematic for the glass waste form, they accumulate in the Recycle stream, exacerbating their impact on the number of LAW glass containers. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to acceptable concentrations in the LAW glass, and reducing the halides in the Recycle is a key component of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, this stream does not have a proven disposition path, and resolving this gap becomes vitally important. This task seeks to examine the impact of potential future disposition of this stream in the Hanford tank farms, and to develop a process that will remove radionuclides from this stream and allow its diversion to another disposition path, greatly decreasing the LAW vitrification mission duration and quantity of glass waste. The origin of this LAW Recycle stream will be from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW melter off-gas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover or precipitates of scrubbed components (e.g. carbonates). The soluble

  2. Wettability alteration by trimeric cationic surfactant at water-wet/oil-wet mica mineral surfaces

    International Nuclear Information System (INIS)

    The wettability of oil reservoir rock affects the efficiency of the oil recovery process by reducing the capillary force. Methyldodecylbis [2-(dimethyldodecylammonio) ethyl] ammonium tribromide is a trimeric cationic surfactant that contains three dodecyl chains and three quaternary ammonium head groups connected by divinyl groups. The surfactant was synthesized, purified and used as a new wetting alteration agent. This paper focuses on the ability of this trimeric cationic surfactant to alter the wettability of water-wet and oil-wet mica mineral surfaces. The contact angle data of the solid-liquid interface in oil/water/solid three-phase system show that the trimeric cationic surfactant, when compared with single- and double-chain cationic surfactant, is a more effective wetting agent for water-wet and oil-wet mica surfaces at lower concentration. Measurements by atomic force microscopy (AFM) show that the surfactant molecules have formed a monolayer to reverse the wetting properties. On the water-wet surface, the surface is suffused with negative charge, which could attract the cationic head of surfactant, and leave the hydrophobic tails exposed. In contrast, on the oil-wet surface, the hydrophobic tails were attracted by hydrophobic interactions to the oil film between the surfactant and the crude oil. The hydrophilic heads were left outside to form a hydrophilic layer, which could explain the wettable to hydrophilic trend. Alteration to the degree of wettability is mainly dependent on the adsorption areas of the surfactant. The data show that the ability of the trimeric cationic surfactant affect the wettability is independent of surface tension.

  3. Turbulent flow over wetted and non-wetted superhydrophobic counterparts with random structure

    Science.gov (United States)

    Vajdi Hokmabad, B.; Ghaemi, S.

    2016-01-01

    The turbulent structure of a channel flow over a non-wetted superhydrophobic (SHO) surface is experimentally investigated at Re = 9600 (based on channel width) at the region of y+ > 10 within the buffer and logarithmic layers. The SHO surface has a random pattern produced by spray coating and is compared with a wetted counterpart and also a smooth surface. Two planar particle image velocimetry measurements are carried out in the streamwise/spanwise and streamwise/wall-normal planes. The vector fields are obtained from both ensemble averaging and individual cross-correlations of double-frame images. The results showed a small increase (˜5%) of the mean velocity profile at y+ = 10 over the non-wetted surface in comparison with the wetted and the smooth surfaces. Up to 15% reduction of normal and shear Reynolds stresses is observed in the inner layer over the non-wetted SHO surface. The wetted SHO counterpart demonstrates no effect on the mean velocity and Reynolds stresses in comparison with the smooth surface. The result confirms the comment of Gad-el-Hak ["Experimental study of skin friction drag reduction on superhydrophobic flat plates in high Reynolds number boundary layer flow," Phys. Fluids 25, 025103 (2013)] that the wetted SHO is hydrodynamically smooth if the surface pores are smaller than the viscous sublayer thickness. A noticeable suppression of the sweep and ejection events, increase of the spanwise spacing of the low and high speed streaks, and attenuation of vortical structures are observed over the non-wetted SHO. These indicate attenuation of the turbulence regeneration cycle due to the slip boundary condition over the non-wetted SHO surfaces with random texture.

  4. Residential Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde; Matsufuji, Y.

    2011-01-01

    are discussed in this chapter. Characterizing residential waste is faced with the problem that many residences already divert some waste away from the official collection systems, for example performing home composting of vegetable waste and garden waste, having their bundled newspaper picked up by......Residential waste comes from residential areas with multi-family and single-family housing and includes four types of waste: household waste, garden waste, bulky waste and household hazardous waste. Typical unit generation rates, material composition, chemical composition and determining factors...... the scouts twice a year or bringing their used furniture to the flea markets organized by charity clubs. Thus, much of the data available on residential waste represents collected waste and not necessarily all generated waste. The latter can only be characterized by careful studies directly at the...

  5. Residential Waste

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Fruergaard, Thilde; Matsufuji, Y.

    2011-01-01

    Residential waste comes from residential areas with multi-family and single-family housing and includes four types of waste: household waste, garden waste, bulky waste and household hazardous waste. Typical unit generation rates, material composition, chemical composition and determining factors...... are discussed in this chapter. Characterizing residential waste is faced with the problem that many residences already divert some waste away from the official collection systems, for example performing home composting of vegetable waste and garden waste, having their bundled newspaper picked up by...... the scouts twice a year or bringing their used furniture to the flea markets organized by charity clubs. Thus, much of the data available on residential waste represents collected waste and not necessarily all generated waste. The latter can only be characterized by careful studies directly at the...

  6. Two remarks on wetting and emulsions

    OpenAIRE

    de Gennes, Pierre-Gilles

    2000-01-01

    This paper is extracted from an opening address given at the workshop "Wetting: from microscopic origins to industrial applications" (Giens, May 6-12, 2000). It discusses two special points a) the nature of line energies for a contact line b) the aging of emulsions.

  7. A literature review on wet deposition

    International Nuclear Information System (INIS)

    The literature on wet deposition or precipitation scavenging have been reviewed with special reference to predicting the radiological consequences of accidental contamination. The work was part of the EEC Radiation Protection Programme and done under a subcontract with Association Euratom-C.E.A. No. SC-014-BIAF-423-DK(SD). (author)

  8. Starch in the Wet-End

    Science.gov (United States)

    de Clerck, Peter

    Starch has been used in papermaking almost since the invention of paper. The global paper industry consumes almost 5 million tonnes of starch per year, making starch the third most important raw material in papermaking. Roughly 20% of this is used in the wet-end.

  9. 49 CFR 173.159 - Batteries, wet.

    Science.gov (United States)

    2010-10-01

    ... Batteries, wet. (a) Electric storage batteries, containing electrolyte acid or alkaline corrosive battery... (h) of this section and in §§ 173.220 and 173.222; and any battery or battery-powered device must be..., but not limited to: (i) Packaging each battery or each battery-powered device when practicable,...

  10. Characteristics of wetting temperature during spray cooling

    International Nuclear Information System (INIS)

    An experimental study has been done to elucidate the effects of mass flux and subcooling of liquid and thermal properties of solid on the wetting temperature during cooling of a hot block with spray. A water spray was impinged at one of the end surfaces of a cylindrical block initially heated at 400 or 500degC. The experimental condition was mass fluxes G=1-9 kg/m2 s and degrees of subcooling ΔTsub =20, 50, 80 K. Three blocks of copper, brass and carbon steel were prepared. During spray cooling internal block temperature distribution and sputtering sound pressure level were recorded and the surface temperature and heat flux were evaluated with 2D inverse heat conducting analysis. Cooling process on cooling curves is divided into four regimes categorized by change in a flow situation and the sound level. The wetting temperature defined as the wall temperature at a minimum heat flux point was measured over an extensive experimental range. The wetting wall temperature was correlated well with the parameter of GΔTsub. The wetting wall temperature increases as GΔTsub increases and reaches a constant value depending on the material of the surface at higher region of GΔTsub. (author)

  11. Verification of wet blasting decontamination technology

    International Nuclear Information System (INIS)

    Macoho Co., Ltd. participated in the projects of 'Decontamination Verification Test FY 2011 by the Ministry of the Environment' and 'Decontamination Verification Test FY 2011 by the Cabinet Office.' And we tested verification to use a wet blasting technology for decontamination of rubble and roads contaminated by the accident of Fukushima Daiichi Nuclear Power Plant of the Tokyo Electric Power Company. As a results of the verification test, the wet blasting decontamination technology showed that a decontamination rate became 60-80% for concrete paving, interlocking, dense-grated asphalt pavement when applied to the decontamination of the road. When it was applied to rubble decontamination, a decontamination rate was 50-60% for gravel and approximately 90% for concrete and wood. It was thought that Cs-134 and Cs-137 attached to the fine sludge scraped off from a decontamination object and the sludge was found to be separated from abrasives by wet cyclene classification: the activity concentration of the abrasives is 1/30 or less than the sludge. The result shows that the abrasives can be reused without problems when the wet blasting decontamination technology is used. (author)

  12. Rhizoctonia seed, seedling, and wet root rot

    Science.gov (United States)

    Wet root rot caused by Rhizoctonia solani Kühn can cause seed and seedling rot of both lentil and chickpea as well as many other agricultural crops worldwide. The pathogen is favored in cool, sandy soil with high organic matter under no-till or reduced-till soil management practices. Survival spor...

  13. Analysis of Altimeter Wet Troposphere Range Correction

    Institute of Scientific and Technical Information of China (English)

    纪永刚; 张杰; 姬光荣; 张有广

    2004-01-01

    Wet path delay caused by tropospheric water vapor must be considered before altimeter data are used in oceanic application. This paper analyzed several methods of atmosphere water range correction (AWRC) using Seasat, Geosat, TOPEX and ERS-1 data, especially the calculated delay path using brightness temperature of TMR on TOPEX and EMR on ERS-1; and discussed some other problems of AWRC.

  14. Synthesis of Multiphase SYNROC Powders as a High Level Radioactive Waste Ceramic Forms by a Solution Combustion Synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Han, Young-Min; Jung, Soo-Ji; Kim, Yeon-Ku; Jung, Choong-Hwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    These minerals have the capacity to accept nearly all of the elements present in the high-level nuclear waste (radwaste) produced during the reprocessing of spent nuclear fuel rods of nuclear reactors. Synroc minerals can accommodate up to 20 wt% (as oxide) of radwaste in their crystal lattices as dilute solid solutions. Synroc-B refers to the waste free composition, proposed for the immobilization of nuclear wastes generated in the commercial nuclear power plants, while the waste-loaded synroc is called synroc-C. The oxide-route (solid state reaction) with high temperatures and long sintering times is the most known process to form a solid solution. However, the synthesis of nano powders using an exothermic redox reaction between nitrate and organics in an aqueous solution has been reported. Most of the high-level radioactive wastes forms were dissolved in nitric acid, and therefore the solution combustion synthesis (hereafter called SCS) which uses all of the metal nitrates as reactant materials is a very promising process to immobilize the radioactive metal element wastes in the form of solid solutions. During the combustion, a significant volume of gas evolved and the high temperature inherent to the highly exothermic nature led to fine and homogeneous well-crystallized powder within a short reaction time. The following conclusions were obtained by comparing the combustion synthesis with the oxide route synthesized Synroc-B powders. With Oxide route synthesized synthesis through a wet ball milling and with a calcination temperature at 1100 .deg. C, the synthesized particles do not match the Synroc-B composition. It was determined to be a heterogeneous particle size showed about 1μm. However, Synroc-B particles prepared by combustion synthesis showed all Hollandite, Zirconolite, Perovskite and Rutile structures having a configuration of the complete Synroc-B at a calcination temperature of 1100 .deg. C.

  15. Synthesis of Multiphase SYNROC Powders as a High Level Radioactive Waste Ceramic Forms by a Solution Combustion Synthesis

    International Nuclear Information System (INIS)

    These minerals have the capacity to accept nearly all of the elements present in the high-level nuclear waste (radwaste) produced during the reprocessing of spent nuclear fuel rods of nuclear reactors. Synroc minerals can accommodate up to 20 wt% (as oxide) of radwaste in their crystal lattices as dilute solid solutions. Synroc-B refers to the waste free composition, proposed for the immobilization of nuclear wastes generated in the commercial nuclear power plants, while the waste-loaded synroc is called synroc-C. The oxide-route (solid state reaction) with high temperatures and long sintering times is the most known process to form a solid solution. However, the synthesis of nano powders using an exothermic redox reaction between nitrate and organics in an aqueous solution has been reported. Most of the high-level radioactive wastes forms were dissolved in nitric acid, and therefore the solution combustion synthesis (hereafter called SCS) which uses all of the metal nitrates as reactant materials is a very promising process to immobilize the radioactive metal element wastes in the form of solid solutions. During the combustion, a significant volume of gas evolved and the high temperature inherent to the highly exothermic nature led to fine and homogeneous well-crystallized powder within a short reaction time. The following conclusions were obtained by comparing the combustion synthesis with the oxide route synthesized Synroc-B powders. With Oxide route synthesized synthesis through a wet ball milling and with a calcination temperature at 1100 .deg. C, the synthesized particles do not match the Synroc-B composition. It was determined to be a heterogeneous particle size showed about 1μm. However, Synroc-B particles prepared by combustion synthesis showed all Hollandite, Zirconolite, Perovskite and Rutile structures having a configuration of the complete Synroc-B at a calcination temperature of 1100 .deg. C

  16. Treatment and disposal of steam generator and heat exchanger chemical cleaning wastes

    International Nuclear Information System (INIS)

    Wet air oxidation was effective in reducing the organic loading of Ontario Hydro's EDTA-based steam generator cleaning wastes and the organic acid formulation used for heat exchanger chemical cleaning. Destruction of the complexing agents resulted in direct precipitation of iron from the waste steam generator magnetite solvent and from the heat exchanger cleaning waste. The oxidized liquors contain lower molecular weight organic acids, ammonia and amines, suitable for secondary biological treatment. The oxidized copper waste requires further treatment to reduce dissolved copper levels prior to biological digestion. A preliminary evaluation of UV and ozone degradation of these wastes showed less promise than wet air oxidation. 24 refs., 1 fig., 4 tabs

  17. Removal of active iodine/iodate from liquid wastes

    International Nuclear Information System (INIS)

    The work described in this report has involved the development of two techniques, ultrafiltration (UF) and electrochemical ion exchange (EIX), for the removal of active iodine/iodate from aqueous wastes. (author)

  18. ANSTO's waste forms for the 31. century

    International Nuclear Information System (INIS)

    ANSTO waste form development for high-level radioactive waste is directed towards practical applications, particularly problematic niche wastes that do not readily lend themselves to direct vitrification. Integration of waste form chemistry and processing method is emphasised. Some longstanding misconceptions about titanate ceramics are dealt with. We have a range of titanate-bearing waste form products aimed at immobilisation of tank wastes and sludges, actinide-rich wastes, INEEL calcines and Na-bearing liquid wastes, Al-rich wastes arising from reprocessing of Al-clad fuels, Mo-rich wastes arising from reprocessing of U-Mo fuels, partitioned Cs-rich wastes, and 99Tc. Waste form production techniques cover hot isostatic and uniaxial pressing, sintering, and cold-crucible melting, and these are strongly integrated into waste form design. Speciation and leach resistance of Cs and alkalis in cementitious products and geo-polymers are being studied. Recently we have embarked on studies of candidate inert matrix fuels for Pu burning. We also have a considerable program directed at basic understanding of the waste forms in regard to crystal chemistry, dissolution behaviour in aqueous media, radiation damage effects and optimum processing techniques. (authors)

  19. Stepwise approach to establishing an ophthalmology wet laboratory.

    Science.gov (United States)

    Henderson, Bonnie An; Grimes, Kelly J; Fintelmann, Robert E; Oetting, Thomas A

    2009-06-01

    Wet laboratories (wet labs) play an increasingly important role in ophthalmology surgical residency training. We summarize the necessary components in establishing and maintaining a well-functioning wet lab and offer a stepwise guide for educators to improve the quality of the wet lab experience. We present 6 key factors in creating an ophthalmology wet lab; that is, setting up the physical space, establishing appropriate faculty and curriculum, obtaining the practice eye, stabilizing the eye, preparing the eye, and funding the wet lab. PMID:19465299

  20. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    Directory of Open Access Journals (Sweden)

    Neil J Shirtcliffe

    Full Text Available Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted, texture (smooth, rough or granular or wetting property (hydrophilic or hydrophobic via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  1. Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces

    Science.gov (United States)

    Shirtcliffe, Neil J.; McHale, Glen; Newton, Michael I.

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces. PMID:22693563

  2. Regional Air Quality Model Application of the Aqueous-Phase Photo Reduction of Atmospheric Oxidized Mercury by Dicarboxylic Acids

    Science.gov (United States)

    In most ecosystems, atmospheric deposition is the primary input of mercury. The total wet deposition of mercury in atmospheric chemistry models is sensitive to parameterization of the aqueous-phase reduction of divalent oxidized mercury (Hg2+). However, most atmospheric chemistry...

  3. A Hybrid Dry and Aqueous Fractionation Method to Obtain Protein-Rich Fractions from Quinoa (Chenopodium quinoa Willd)

    NARCIS (Netherlands)

    Avila Ruiz, Geraldine; Arts, Anke; Minor, Marcel; Schutyser, Maarten

    2016-01-01

    Combination of dry and aqueous fractionation is investigated to obtain protein-rich fractions from quinoa in a milder and more sustainable way compared to conventional wet fractionation. Dry fractionation of quinoa involved milling and subsequent air classification, generating a protein-enriched

  4. Leachate Treatment UsingWet Air Oxidation Processes

    Directory of Open Access Journals (Sweden)

    A Ebrahimi

    2011-04-01

    Full Text Available "nBackground and Objectives: Wet air oxidation (WAO is One of the advanced oxidation process which reduce organic matter concentration from industrial wastewater, toxic and non biodegradable substances and, solid waste leachate,etc. In this study the efficiency of wet air oxidation method in leachate treatment generating from Esfahan Composting factory was Evaluated."nMaterial and Methods: The experiment was carried out by adding 1.5 Lit of pretreated leachate sample the steel reactor with the volume of 3L. The reactor then underwent10 bar pressure at different temperature (100, 200 and 300 °C and various retention time (30, 60 and 90 min. Leachate sample in 18 stages from composting factory in Isfahan in the volume of 20 Lit was taken and the WAO method, was used for pre-treatments. Removal efficiency of COD, BOD, NH4-N, NO3 and TSS were examined."nResults: The results showed that the removal efficiency was more than 35% for COD, 38% for BOD, and 85% for TSS within one hour of reaction. The Maximum removal efficiency obtained in this study were 53.3% for NH4-N and 73.9 % forNO3-N."nConclusion: the results indicate that the reaction temperatures are the most important factors affecting degradation of organic matter. COD and BOD5 removal efficiency by WAO process increased as the time of reaction went up. In addition, BOD5/COD ratios of the effluents, which are generally regarded as an important index of biodegradability of leachate sample, were determined and improved grately as it reached to 84%. TheWAO process presented in this paper is considered an efficient process for pretreatment of leachate, as the COD, BOD5 and NO3 reduction observed in leachate samples.

  5. Frozen soil barriers for hazardous waste confinement

    Energy Technology Data Exchange (ETDEWEB)

    Dash, J.G.; Leger, R. [Univ. of Washington, Seattle, WA (United States); Fu, H.Y. [Univ. of California, Santa Barbara, CA (United States)

    1997-12-31

    Laboratory and full field measurements have demonstrated the effectiveness of artificial ground freezing for the containment of subsurface hazardous and radioactive wastes. Bench tests and a field demonstration have shown that cryogenic barriers are impenetrable to aqueous and non aqueous liquids. As a result of the successful tests the US Department of Energy has designated frozen ground barriers as one of its top ten remediation technologies.

  6. Wet Adhesion and Adhesive Locomotion of Snails on Anti-Adhesive Non-Wetting Surfaces

    OpenAIRE

    Shirtcliffe, Neil; McHale, Glen; Newton, Michael

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and th...

  7. The TEES process cleans waste and produces energy

    International Nuclear Information System (INIS)

    A gasification system is under development that can be used with most types of wet organic wastes. The system operates at 350 degrees C and 205 atm using a liquid water phase as the processing medium. Since a pressurized system is used, the wet waste can be fed as a solution or slurry to the reactor without drying. Through the development of catalysts, a useful processing system has been produced. The system has utility both for direct conversion of high-moisture biomass to fuel gas or as a wastewater cleanup system for wet organic wastes including unconverted biomass from bioconversion processes. By the use of this system >99% conversions of organic waste to medium-Btu fuel gas can be achieved

  8. Technical and economic assessments of ethanol production from citrus peel waste

    Science.gov (United States)

    Each year, the Florida citrus juice industry produces about 3.5-5.0 million tons of wet peel waste, which are currently dried and sold as cattle feed, often at a loss, to dispose of the waste residual. Profitability would be greatly improved if the peel waste could be used to produce higher value p...

  9. Anaerobic Digestion of the Organic Fraction of Municipal Solid Waste With Recirculation of Process Water

    DEFF Research Database (Denmark)

    Hartmann, H.; Angelidaki, Irini; Ahring, Birgitte Kiær

    2001-01-01

    A new concept of a wet anaerobic digestion treatment of the organic fraction of municipal solid waste (OFMSW) is investigated. Once the waste is diluted with water, the entire liquid fraction of the effluent is recirculated and used as process water for dilution of the waste. This enables a well...

  10. Pyrochlore as nuclear waste form. Actinide uptake and chemical stability

    International Nuclear Information System (INIS)

    crystal structure were synthesised via a wet-chemical coprecipitation route to obtain highly homogeneous ceramics. Their structure-properties relationships were studied by a combination of different characterisation techniques, e.g. powder X-Ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and luminescence spectroscopy. These complementary techniques were chosen to gain insight into the radionuclide uptake and order-disorder transition from a bulk to a local structural level. The transition of pyrochlore to the less ordered defect fluorite phase was examined by XRD and TEM and recognized to be a gradual transition. This transition was proven to have no significant impact on the aqueous durability under acidic conditions. In addition to their high radiation tolerance ZrO2 based pyrochlores are therefore expected to ensure high long-term durability even during the decay of embedded radionuclides. The radionuclide uptake on well-defined lattice positions within the pyrochlore crystal structure was probed by luminescence spectroscopy (time resolved laser fluorescence spectroscopy, TRLFS) of Cm and Eu doped La2Zr2O2 pyrochlores and defect fluorite samples. TRLFS is an ideal method to unravel the lattice site by probing the local environment of the dopant. According to TRLFS results Eu and Cm adopt the A site within the pyrochlore crystal structure and regular cation lattice sites in the defect fluorite. In addition, a minor species is present in the pyrochlore which was identical to the major species observed in the defect fluorite. Vice versa, the defect fluorite contains a minor species which has adopted the pyrochlore environment. This is in good agreement with the TEM findings. Due to the different pyrochlore and defect fluorite species, TRLFS could be used as a tool to quantify radiation damage in ZrO2 based pyrochlore nuclear waste forms. In order to more closely imitate a realistic waste form 5 mol% and 10 mol% Pu

  11. Pyrochlore as nuclear waste form. Actinide uptake and chemical stability

    Energy Technology Data Exchange (ETDEWEB)

    Finkeldei, Sarah Charlotte

    2015-07-01

    with pyrochlore and defect crystal structure were synthesised via a wet-chemical coprecipitation route to obtain highly homogeneous ceramics. Their structure-properties relationships were studied by a combination of different characterisation techniques, e.g. powder X-Ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and luminescence spectroscopy. These complementary techniques were chosen to gain insight into the radionuclide uptake and order-disorder transition from a bulk to a local structural level. The transition of pyrochlore to the less ordered defect fluorite phase was examined by XRD and TEM and recognized to be a gradual transition. This transition was proven to have no significant impact on the aqueous durability under acidic conditions. In addition to their high radiation tolerance ZrO{sub 2} based pyrochlores are therefore expected to ensure high long-term durability even during the decay of embedded radionuclides. The radionuclide uptake on well-defined lattice positions within the pyrochlore crystal structure was probed by luminescence spectroscopy (time resolved laser fluorescence spectroscopy, TRLFS) of Cm and Eu doped La{sub 2}Zr{sub 2}O{sub 2} pyrochlores and defect fluorite samples. TRLFS is an ideal method to unravel the lattice site by probing the local environment of the dopant. According to TRLFS results Eu and Cm adopt the A site within the pyrochlore crystal structure and regular cation lattice sites in the defect fluorite. In addition, a minor species is present in the pyrochlore which was identical to the major species observed in the defect fluorite. Vice versa, the defect fluorite contains a minor species which has adopted the pyrochlore environment. This is in good agreement with the TEM findings. Due to the different pyrochlore and defect fluorite species, TRLFS could be used as a tool to quantify radiation damage in ZrO{sub 2} based pyrochlore nuclear waste forms. In order to more closely

  12. Conditioning of radioactive waste solutions by cementation

    International Nuclear Information System (INIS)

    For the cementation of the low and intermediate level evaporator concentrates resulting from the reprocessing of spent fuel numerous experiments were performed to optimize the waste form composition and to characterize the final waste form. Concerning the cementation process, properties of the waste/cement suspension were investigated. These investigations include the dependence of viscosity, bleeding, setting time and hydration heat from the waste cement slurry composition. For the characterization of the waste forms, the mechanical, thermal and chemical stability were determined. For special cases detailed investigations were performed to determine the activity release from waste packages under defined mechanical and thermal stresses. The investigations of the interaction of the waste forms with aqueous solutions include the determination of the Cs/Sr release, the corrosion resistance and the release of actinides. The Cs/Sr release was determined in dependence of the cement type, additives, setting time and sample size. (orig./DG)

  13. Environmental applications of steel industry solid wastes

    OpenAIRE

    Vega Aguirre, Noelia; Montes Morán, Miguel Ángel; Ovín Ania, María Concepción; Canals-Batlle, C.; González-Suárez, V.; Martín, María J.

    2009-01-01

    Various solid residues from steel industry were tested as adsorbents of hydrogen sulfide at high concentrations. Their performance towards the removal of thiocyanates from aqueous solutions was also studied. The H2S adsorption capacity was evaluated at room temperature under both dry and wet conditions. The removal efficiency for thiocyanate ions from solution was evaluated at high ionic concentration. In both cases the results were compared to those of other adsorb...

  14. Experimental Investigation of Wetting with Magnetic Fluids.

    Science.gov (United States)

    Manukyan, Selin; Schneider, Marius

    2016-05-24

    Here we report the experimental results of the general wetting behavior of an oil-based ferrofluid and a water-based magnetic paint droplet on a hydrophobic surface under the effect of an external magnetic field. By increasing the magnetic field in the vertical direction, the height of the oil-based ferrofluid droplet increases while the width decreases; on the contrary, under the same circumstances, the height of the water-based magnetic paint droplet decreases whereas the width increases. The wetting behavior of the oil-based ferrofluid and the water-based magnetic paint droplets is evaluated as a function of the contact angle, contact line diameter, and hysteresis curve alterations. Conclusively, a general explanation is given for the contrary behavior of both liquids, and some application processes for future implementations are introduced. PMID:27119597

  15. Liquid holdup in wet-gas pipelines

    International Nuclear Information System (INIS)

    An experimental study of two-phase flow was conducted to investigate liquid holdup in wet-gas pipelines. The liquid-holdup data were obtained by passing spheres through a 1,333-ft [406.3-m] -long, 3.068-in. [77.93-mm] -ID horizontal pipe and measuring the liquid volumes removed. Three different two-phase mixtures were used. The holdup data were compared with predicted holdup values and were used to evaluate a mechanistic model for stratified flow. None of the methods could accuratly predict liquid holdup in this low-holdup region. Two new empirical liquid-holdup correlations for horizontal flow were proposed. The first is strictly for wet-gas pipelines (0< y/sub L/<0.35); the second is for any horizontal pipeline (0< y/sub L/<1.0)

  16. Wet precipitators for sulphuric acid plants

    International Nuclear Information System (INIS)

    Both the service requirements and design construction details have changed considerably in recent years for wet electrostatic precipitators as used for gas cleaning ahead of metallurgical sulphuric acid plants. Increased concern over acid quality has resulted in more emphasis on dust efficiencies compared to collection of acid mist. Also, higher static operating pressures have caused large structural loads on casing and internal components. In this paper these two issues are addressed in the following ways: Recognition that all dusts do not collect similarly. The mechanism by which various dusts collect affect the design of the entire wet gas cleaning system. Use of both traditional and newer materials of construction to accommodate the higher design pressures while still maintaining corrosion resistance

  17. Wetting films stabilized by block-copolymers

    NARCIS (Netherlands)

    Eliseeva, O.V.

    2006-01-01

    Thin aqueous films formed on a solid surface play an important role in adhesion, spreading, and colloidal stability. These phenomena are all relevant for paint systems. Measuring surface forces in these films is an experimental challenge, and over the years several techniques have been developed to

  18. Aqueous Two-phase Gas Floatation Spectrometric Determination of Trace Oxytetracycline in Waste Water%双水相气浮浮选光度法分离/测定废水中痕量土霉素

    Institute of Scientific and Technical Information of China (English)

    侯延民; 谢吉民; 李春香; 赵晓军

    2009-01-01

    利用自制的浮选装置,选择四氢呋喃作溶剂,氯化钠作分相剂,NaOH溶液调节酸度,将Zn(Ⅱ)与土霉素(OTC)形成的疏水性缔合物浮选至有机相,直接用分光光度法测定含量,方法线性回归方程为A=2.046×10~5c(mol/L)+0.015,相关系数为0.999 6,线性范围为1.7×10~(-7)9.3×L10~(-5) mol/L;检出限为7.16×10~(-8) mol/L;回收率为98.7%~100.5%;表观摩尔吸光系数为2.046×10~5 L/(mol·cm),适用于废水中痕量土霉素的分离/富集及分析测定.%The hydrophobic complex composed of Zn(Ⅱ) and oxytetracycline(OTC) was floated into organic phase under the optimal conditions:pH=9, tetrahydrofuran as organic solvent, sodium chloride as separating phase reagent on the home-made floatation equipment. The data was obtained by spectrophotometry after floatation, the linear regression equation was A=2.046×10~5c(mol/L)+0.015, linear range was from 1.7×10~(-7) to 9.3×10~(-5) mol/L, correlation coefficient(r) was 0.999 6, relative recovery was 98.7%~100.5%, and the limit of detection was 7.16×10~(-8) mol/L. It can be applied to the analysis of trace OTC in waste water.

  19. Dry-Wet Fermentation for Biogas Production

    OpenAIRE

    Ahlhaus, M; Barz, M; Vogel, T.

    2008-01-01

    At present biogas plants produce biogas mainly from slurry by liquid fermentation. But the low substrate digestation of herbaceous biomass by liquid fermentation permits to use only a low amount of herbaceous biomass. Since April 2007 the collaborative project entitled “Development of a combined dry-wet fermentation process to produce biogas from herbaceous biomass substrates” is conducted at the Laboratory for Integrated Energy Systems of the University of Applied Sciences in ...

  20. Study of polycaprolactone wet electrospinning process

    OpenAIRE

    E. Kostakova; M. Seps; P. Pokorny; Lukas, D.

    2014-01-01

    Wet electrospinning is a useful method for 3-dimensional structure control of nanofibrous materials. This innovative technology uses a liquid collector instead of the metal one commonly used for standard electrospinning. The article compares the internal structural features of polycaprolactone (PCL) nanofibrous materials prepared by both technologies. We analyze the influence of different water/ethanol compositions used as a liquid collector on the morphology of the resultant polycaprolactone...