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Sample records for chloralkali electrolysis wastewater

  1. Determination of nickel in chloralkali electrolysis brines by X-ray fluorescence spectrometry on a membrane filter

    Andrade, L.L.; Minzl, E.

    1984-01-01

    X-ray fluorescence spectrometry after ammonium pyrrolidinedithiocarbamate (APDC) preconcentration is proposed for the determination of nickel in chloralkali electrolysis brines. The optimum conditions for the precipitation target tube, peak intensity, background, analysing crystal, counters and exposure time were investigated. The method was applied to chloralkali brines of evaporite salts (halite, sylvinite, carnallite and tachhydrite), sodium, potassium and magnesium salts, explored in Sergipe (Brazil), by Petrobras-Mineracao S.A.(Author) [pt

  2. Micro-electrolysis technology for industrial wastewater treatment.

    Jin, Yi-Zhong; Zhang, Yue-Feng; Li, Wei

    2003-05-01

    Experiments were conducted to study the role of micro-electrolysis in removing chromaticity and COD and improving the biodegradability of wastewater from pharmaceutical, dye-printing and papermaking plants. Results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of pharmaceutical wastewater. Lower initial pH could be advantageous to the removal of chromaticity. A retention time of 30 minutes was recommended for the process design of micro-electrolysis. For the use of micro-electrolysis in treatment of dye-printing wastewater, the removal rates of both chromaticity and COD were increased from neutral condition to acid condition for disperse blue wastewater; more than 90% of chromaticity and more than 50% of COD could be removed in neutral condition for vital red wastewater.

  3. Treatment of high salinity organic wastewater by membrane electrolysis

    Dongfang, Shen; Jinghuan, Ma; Ying, Liu; Chenguang, Zhao

    2018-03-01

    The effects of different operating conditions on the treatment of electrolytic wastewater were investigated by analyzing the removal rate of ammonia and COD before and after wastewater treatment by cation exchange membrane. Experiment shows that as the running time increases the electrolysis effect first increases after the smooth. The removal rate of ammonia will increase with the increase of current density, and the removal rate of COD will increase first and then decrease with the increase of current density. The increase of the temperature of the electrolytic solution will slowly increase the COD removal rate to saturation, but does not affect the removal of ammonia nitrogen. When the flow rate is less than 60L / h, the change of influent flow rate will not affect the removal of ammonia nitrogen, but the effect on COD is small, which will increase and decrease slightly. After the experiment, the surface of the cation exchange membrane was analyzed by cold field scanning electron microscopy and X-ray energy dispersive spectrometer. The surface contamination and the pollutant were determined. The experimental results showed that the aggregates were mainly chlorinated Sodium, calcium and magnesium inorganic salts, which will change the morphology of the film to reduce porosity, reduce the mass transfer efficiency, affecting the electrolysis effect.

  4. Denitrification of coking wastewater with micro-electrolysis.

    Lv, Yanli; Wang, Yanqiu; Shan, Mingjun; Shen, Xue; Su, Ying

    2011-06-01

    The denitrification for the coking wastewater was conducted by means of original battery principle with Fe-C micro-electrolysis. Fe-C serves as positive and negative electrodes, by which N02(-)-N and TN were reduced to nitrogen, and then the purpose of denitrifieation for coking wastewater was realized. The influences of pH value, carbon particle size, Fe/C ratio (mass ratio), reaction time and coagulation pH value on removal rate of N02(-)-N and TN were investigated. Coking wastewater originated from Jiamusi Coal Chemistry Engineering Company. The optimum conditions of treatment were as follows: the initial pH was 3.0, the dosage of Fe 73.5 g/L, reaction time 70 min, mass ratio of Fe/C ratio 1.0:1.3, coagulation pH 9.0 and sedimentation time 40 min. Under those conditions, nitrogen removal efficiencies of N02(-)-N and TN were beyond 50% and 45%, respectively. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  5. A quantitative method to evaluate microbial electrolysis cell effectiveness for energy recovery and wastewater treatment

    Ivanov, Ivan; Ren, Lijiao; Siegert, Michael; Logan, Bruce E.

    2013-01-01

    Microbial electrolysis cells (MECs) are potential candidates for sustainable wastewater treatment as they allow for recovery of the energy input by producing valuable chemicals such as hydrogen gas. Evaluating the effectiveness of MEC treatment

  6. Treatment of chitin-producing wastewater by micro-electrolysis-contact oxidization.

    Yang, Yue-ping; Xu, Xin-hua; Chen, Hai-feng

    2004-04-01

    The technique of micro-electrolysis-contact oxidization was exploited to treat chitin-producing wastewater. Results showed that Fe-C micro-electrolysis can remove about 30% COD(cr), raise pH from 0.7 to 5.5. The COD(cr) removal efficiency by biochemical process can be more than 80%. During a half year's operation, the whole system worked very stably and had good results, as proved by the fact that every quality indicator of effluent met the expected discharge standards; which means that chitin wastewater can be treated by the technique of micro-electrolysis, contact oxidization.

  7. Electrolysis

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

    Electrolysis is a well-established technology with many different applications. In particular, it can be used to produce hydrogen by using electricity to split water. As an increasing part of the energy system consists of fluctuating power sources such as wind and solar it becomes increasingly...... necessary to be able to store large amounts of electrical energy. One option is to do it in the form of hydrogen or hydrogen-rich synthetic compounds. This has led to increased interest in electrolysis with new cell types being developed. This entry provides an overview of the status and technological...... challenges of electrolysis systems and discusses their role in the future energy system....

  8. Treatability studies on different refinery wastewater samples using high-throughput microbial electrolysis cells (MECs)

    Ren, Lijiao; Siegert, Michael; Ivanov, Ivan; Pisciotta, John M.; Logan, Bruce E.

    2013-01-01

    High-throughput microbial electrolysis cells (MECs) were used to perform treatability studies on many different refinery wastewater samples all having appreciably different characteristics, which resulted in large differences in current generation. A de-oiled refinery wastewater sample from one site (DOW1) produced the best results, with 2.1±0.2A/m2 (maximum current density), 79% chemical oxygen demand removal, and 82% headspace biological oxygen demand removal. These results were similar to those obtained using domestic wastewater. Two other de-oiled refinery wastewater samples also showed good performance, with a de-oiled oily sewer sample producing less current. A stabilization lagoon sample and a stripped sour wastewater sample failed to produce appreciable current. Electricity production, organics removal, and startup time were improved when the anode was first acclimated to domestic wastewater. These results show mini-MECs are an effective method for evaluating treatability of different wastewaters. © 2013 Elsevier Ltd.

  9. Treatability studies on different refinery wastewater samples using high-throughput microbial electrolysis cells (MECs)

    Ren, Lijiao

    2013-05-01

    High-throughput microbial electrolysis cells (MECs) were used to perform treatability studies on many different refinery wastewater samples all having appreciably different characteristics, which resulted in large differences in current generation. A de-oiled refinery wastewater sample from one site (DOW1) produced the best results, with 2.1±0.2A/m2 (maximum current density), 79% chemical oxygen demand removal, and 82% headspace biological oxygen demand removal. These results were similar to those obtained using domestic wastewater. Two other de-oiled refinery wastewater samples also showed good performance, with a de-oiled oily sewer sample producing less current. A stabilization lagoon sample and a stripped sour wastewater sample failed to produce appreciable current. Electricity production, organics removal, and startup time were improved when the anode was first acclimated to domestic wastewater. These results show mini-MECs are an effective method for evaluating treatability of different wastewaters. © 2013 Elsevier Ltd.

  10. Removal of pigments from molasses wastewater by combining micro-electrolysis with biological treatment method.

    Chen, Ben; Tian, Xiaofei; Yu, Lian; Wu, Zhenqiang

    2016-12-01

    Pigments in molasses wastewater (MWW) effluent, such as melanoidins, were considered as kinds of the most recalcitrant and hazardous colorant contaminants to the environment. In this study, de-coloring the MWW by a synergistic combination of micro-electrolysis with bio-treatment was performed. Aiming to a high de-colorization yield, levels of nutrition source supplies, MWW dilution ratio, and micro-electrolysis reaction time were optimized accordingly. For a diluted (50 %, v/v) MWW, an maximum overall de-colorization yield (97.1 ± 0.5 %, for absorbance at 475 nm) was achieved through the bio-electrolysis treatment. In electrolysis bio-treatment, the positive effect of micro-electrolysis was also revealed by a promoted growth of fungal biomass as well as activities of ligninolytic enzymes. Activities of lignin peroxidase, manganese peroxidase, and laccase were promoted by 111.2, 103.9, and 7.7 %, respectively. This study also implied that the bio-treatment and the micro-electrolysis had different efficiencies on removal of pigments with distinct polarities.

  11. Treatment of oilfield wastewater by combined process of micro-electrolysis, Fenton oxidation and coagulation.

    Zhang, Zhenchao

    2017-12-01

    In this study, a combined process was developed that included micro-electrolysis, Fenton oxidation and coagulation to treat oilfield fracturing wastewater. Micro-electrolysis and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance organic components gradability, respectively. Orthogonal experiment were employed to investigate the influence factors of micro-electrolysis and Fenton oxidation on COD removal efficiency. For micro-electrolysis, the optimum conditions were: pH, 3; iron-carbon dosage, 50 mg/L; mass ratio of iron-carbon, 2:3; reaction time, 60 min. For Fenton oxidation, a total reaction time of 90 min, a H 2 O 2 dosage of 12 mg/L, with a H 2 O 2 /Fe 2+ mole ratio of 30, pH of 3 were selected to achieve optimum oxidation. The optimum conditions in coagulation process: pH, cationic polyacrylamide dosage, mixing speed and time is 4.3, 2 mg/L, 150 rpm and 30 s, respectively. In the continuous treatment process under optimized conditions, the COD of oily wastewater fell 56.95%, 46.23%, 30.67%, respectively, from last stage and the total COD removal efficiency reached 83.94% (from 4,314 to 693 mg/L). In the overall treatment process under optimized conditions, the COD of oily wastewater was reduced from 4,314 to 637 mg/L, and the COD removal efficiency reached 85.23%. The contribution of each stage is 68.45% (micro-electrolysis), 24.07% (Fenton oxidation), 7.48% (coagulation), respectively. Micro-electrolysis is the uppermost influencing process on COD removal. Compared with the COD removal efficiency of three processes on raw wastewater under optimized conditions: the COD removal efficiency of single micro-electrolysis, single Fenton oxidation, single coagulation is 58.34%, 44.88% and 39.72%, respectively. Experiments proved the effect of combined process is marvelous and the overall water quality of the final effluent could meet the class III national wastewater discharge standard of petrochemical industry of China

  12. Evaluation of low cost cathode materials for treatment of industrial and food processing wastewater using microbial electrolysis cells

    Tenca, Alberto; Cusick, Roland D.; Schievano, Andrea; Oberti, Roberto; Logan, Bruce E.

    2013-01-01

    Microbial electrolysis cells (MECs) can be used to treat wastewater and produce hydrogen gas, but low cost cathode catalysts are needed to make this approach economical. Molybdenum disulfide (MoS2) and stainless steel (SS) were evaluated

  13. Pretreatment of wastewater from triazine manufacturing by coagulation, electrolysis, and internal microelectrolysis.

    Cheng, Hefa; Xu, Weipu; Liu, Junliang; Wang, Huanjun; He, Yanqing; Chen, Gang

    2007-07-19

    We studied the pretreatment of concentrated wastewater from triazine manufacturing by coagulation, electrolysis, and internal microelectrolysis. Results show that coagulation by polyaluminum chloride at dosage of 0.5 g/L could remove up to 17.2% chemical oxygen demand (COD) from the wastewater. Electrolysis using iron electrode achieved 33.2% COD removal at current of 2A in 180 min, which was attributed to coagulation and oxidation of the organic contaminants in the wastewater by the radicals (OH and O) and oxidants (O2, O3, and H2O2) produced in electrochemical reactions. Internal microelectrolysis using iron chips and granular activated carbon (GAC) showed that up to 60.5% COD could be removed under the conditions of iron/GAC/wastewater volumetric ratio of 3:2:490, sparge ratio (ratio of air flow rate to volume of wastewater) of 2:490 min(-1), and reaction time of 132 h. COD reduction in internal microelectrolysis was attributed to a combination of chemical and physical processes, mainly oxidation by radicals and oxidants formed in electrochemical reactions, adsorption on, co-precipitation with, and enmeshment in ferrous and ferric hydroxides resulted from Fe2+ released during anode oxidation. The results suggest that internal microelectrolysis using iron chips and GAC is a promising, low-cost alternative for pretreating concentrated wastewater from pesticide manufacturing.

  14. Electrolysis of polluting wastes: I - Wastewater from a seasoning freeze-drying industry

    Angelis, Dejanira F. de; Corso, Carlos R.; Bidoia, Ederio D.; Moraes, Peterson B.; Domingos, Roberto N.; Rocha-Filho, Romeu C.

    1998-01-01

    Wastewater from a seasoning freeze-drying industry was electrolysed to increase its biodegradability. Stainless-steel electrodes were used at 9.09 A/m², for up to 80 min. Conductivity, pH, biochemical (BOD) and chemical (COD) oxygen demands, Daphnia similis acute toxicity bioassays, and bacteria counting through the plate count agar method were determined after different times of electrolysis. The results (e.g. higher BOD and lower COD) showed that the biodegradability of the wastewater was s...

  15. Treatment of coking wastewater by a novel electric assisted micro-electrolysis filter.

    Xie, Ruosong; Wu, Miaomiao; Qu, Guangfei; Ning, Ping; Cai, Yingying; Lv, Pei

    2018-04-01

    A newly designed electric assisted micro-electrolysis filter (E-ME) was developed to investigate its degradation efficiency for coking wastewater and correlated characteristics. The performance of the E-ME system was compared with separate electrolysis (SE) and micro-electrolysis (ME) systems. The results showed a prominent synergistic effect on COD removal in E-ME systems. Gas chromatography/mass spectrometry (GC-MS) analysis confirmed that the applied electric field enhanced the degradation of phenolic compounds. Meanwhile, more biodegradable oxygen-bearing compounds were detected. SEM images of granular activated carbon (GAC) showed that inactivation and blocking were inhibited during the E-ME process. The effects of applied voltage and initial pH in E-ME systems were also studied. The best voltage value was 1V, but synergistic effects existed even with lower applied voltage. E-ME systems exhibited some pH buffering capacity and attained the best efficiency in neutral media, which means that there is no need to adjust pH prior to or during the treatment process. Therefore, E-ME systems were confirmed as a promising technology for treatment of coking wastewater and other refractory wastewater. Copyright © 2017. Published by Elsevier B.V.

  16. Pharmaceutical wastewater treatment by internal micro-electrolysis--coagulation, biological treatment and activated carbon adsorption.

    Wang, Kangle; Liu, Suiqing; Zhang, Qiang; He, Yiliang

    2009-12-01

    Treatment of pharmaceutical wastewater by the combined process of internal micro-electrolysis and coagulation, biological treatment and activated carbon adsorption was studied. Internal micro-electrolysis and coagulation served as the pretreatment for the wastewater before biological treatment to reduce the contaminants' toxicity to microbes and improve the biodegradability of wastewater to guarantee the smooth operation of the biological process. Biological treatment was the main body of the whole process which took an unparalleled role in removing COD (chemical oxygen demand). Activated carbon adsorption was adopted as the post-treatment process to further remove the remaining non-biodegradable particles. Results showed that the removal rates of COD and S2- (sulphide ion) by pretreatment were 66.9% and 98.9%, respectively, and the biodegradability, as measured by the ratio of biodegradable COD to initial COD, of the wastewater was greatly improved from 0.16 +/- 0.02 to 0.41 +/- 0.02. The overall removal rate of COD in the wastewater achieved by this combined treatment process was up to 96%, and the effluent COD met the Chinese tertiary discharge standard (GB 8978-1996).

  17. A quantitative method to evaluate microbial electrolysis cell effectiveness for energy recovery and wastewater treatment

    Ivanov, Ivan

    2013-10-01

    Microbial electrolysis cells (MECs) are potential candidates for sustainable wastewater treatment as they allow for recovery of the energy input by producing valuable chemicals such as hydrogen gas. Evaluating the effectiveness of MEC treatment for different wastewaters requires new approaches to quantify performance, and the establishment of specific procedures and parameters to characterize the outcome of fed-batch treatability tests. It is shown here that Coulombic efficiency can be used to directly calculate energy consumption relative to wastewater treatment in terms of COD removal, and that the average current, not maximum current, is a better metric to evaluate the rate of the bioelectrochemical reactions. The utility of these methods was demonstrated using simulated current profiles and actual wastewater tests. Industrial and domestic wastewaters were evaluated using small volume MECs, and different inoculation strategies. The energy needed for treatment was 2.17kWhkgCOD-1 for industrial wastewater and 2.59kWhkgCOD-1 for domestic wastewater. When these wastewaters were combined in equal amounts, the energy required was reduced to 0.63kWhkgCOD-1. Acclimation of the MEC to domestic wastewater, prior to tests with industrial wastewaters, was the easiest and most direct method to optimize MEC performance for industrial wastewater treatment. A pre-acclimated MEC accomplished the same removal (1847 ± 53 mg L-1) as reactor acclimated to only the industrial wastewater (1839 ± 57 mg L-1), but treatment was achieved in significantly less time (70 h versus 238 h). © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  18. Energy-saving chlorine production. Chlor-alkali electrolysis using innovative cathode technology; Energiesparende Chlorpoduktion. Chlor-Alkali-Elektrolyse mit innovativer Kathoden-Technologie

    Woltering, Peter; Hofmann, Philipp; Funck, Frank; Kiefer, Randolf; Baeumer, Ulf-Steffen; Donst, Dmitri; Schmitt, Carsten [Thyssen Krupp Uhde GmbH, Dortmund (Germany)

    2013-11-01

    Chlorine is used in the synthesis of almost two thirds of all chemical products. Producing chlorine from salt by electrolysis is a very energy-intensive process. Through their joint venture UHDENORA S.p.A., ThyssenKrupp Uhde and Industrie De Nora S.p.A. have played a major part in the development of a globally available technology that can produce chlorine using up to 30 percent less energy than conventional processes. It uses oxygen depolarized cathode technology with an innovative new cathode chamber design in an Uhde single-cell element. In Germany alone, converting all existing plants to the new technology would save enough electricity to power a city the size of Cologne. (orig.)

  19. Efficient treatment of aniline containing wastewater in bipolar membrane microbial electrolysis cell-Fenton system.

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan; Angelidaki, Irini; Zhang, Yifeng

    2017-08-01

    Aniline-containing wastewater can cause significant environmental problems and threaten the humans's life. However, rapid degradation of aniline with cost-efficient methods remains a challenge. In this work, a novel microbial electrolysis cell with bipolar membrane was integrated with Fenton reaction (MEC-Fenton) for efficient treatment of real wastewater containing a high concentration (4460 ± 52 mg L -1 ) of aniline. In this system, H 2 O 2 was in situ electro-synthesized from O 2 reduction on the graphite cathode and was simultaneously used as source of OH for the oxidation of aniline wastewater under an acidic condition maintained by the bipolar membrane. The aniline was effectively degraded following first-order kinetics at a rate constant of 0.0166 h -1 under an applied voltage of 0.5 V. Meanwhile, a total organic carbon (TOC) removal efficiency of 93.1 ± 1.2% was obtained, revealing efficient mineralization of aniline. The applicability of bipolar membrane MEC-Fenton system was successfully demonstrated with actual aniline wastewater. Moreover, energy balance showed that the system could be a promising technology for removal of biorefractory organic pollutants from wastewaters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. The Detoxification and Degradation of Benzothiazole from the Wastewater in Microbial Electrolysis Cells

    Xianshu Liu

    2016-12-01

    Full Text Available In this study, the high-production-volume chemical benzothiazole (BTH from synthetic water was fully degraded into less toxic intermediates of simple organic acids using an up-flow internal circulation microbial electrolysis reactor (UICMER under the hydraulic retention time (HRT of 24 h. The bioelectrochemical system was operated at 25 ± 2 °C and continuous-flow mode. The BTH loading rate varied during experiments from 20 g·m−3·day−1 to 110 g·m−3·day−1. BTH and soluble COD (Chemical Oxygen Demand removal efficiency reached 80% to 90% under all BTH loading rates. Bioluminescence based Shewanella oneidensis strain MR-1 ecotoxicity testing demonstrated that toxicity was largely decreased compared to the BTH wastewater influent and effluent of two control experiments. The results indicated that MEC (Microbial Electrolysis Cell was useful and reliable for improving BTH wastewater treatment efficiency, enabling the microbiological reactor to more easily respond to the requirements of higher loading rate, which is meaningful for economic and efficient operation in future scale-up.

  1. Novel bio-electro-Fenton technology for azo dye wastewater treatment using microbial reverse-electrodialysis electrolysis cell

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan

    2017-01-01

    Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater. In such ......Development of sustanaible technologies for treatment of azo dyes containing wastewaters has long been of great interest. In this study, we proposed an innovative concept of using microbial reverse-electrodialysis electrolysis cell (MREC) based Fenton process to treat azo dye wastewater....... In such MREC-Fenton integrated process, the production of H2O2 which is the key reactant of fenton-reaction was driven by the electrons harvested from the exoelectrogens and salinity-gradient between sea water and fresh water in MREC. Complete decolorization and mineralization of 400 mg L-1 Orange G...

  2. Treatment of bromoamine acid wastewater using combined process of micro-electrolysis and biological aerobic filter.

    Fan, Li; Ni, Jinren; Wu, Yanjun; Zhang, Yongyong

    2009-03-15

    The wastewater originated from the production of bromoamine acid was treated in a sequential system of micro-electrolysis (ME) and biological aerobic filter (BAF). Decolorization and COD(Cr) removal rate of the proposed system was investigated with full consideration of the influence of two major controlling factors such as organic loading rate (OLR) and hydraulic retention time (HRT). The removal rate of COD(Cr) was 81.2% and that of chrominance could be up to 96.6% at an OLR of 0.56 kg m(-3)d(-1) when the total HRT was 43.4h. Most of the chrominance was removed by the ME treatment, however, the BAF process was more effective for COD(Cr) removal. The GC-MS and HPLC-MS analysis of the contaminants revealed that 1-aminoanthraquinone, bromoamine acid and mono-sulfonated 1,2-dichlorobenzene were the main organic components in the wastewater. The reductive transformation of the anthraquinone derivatives in the ME reactor improved the biodegradability of the wastewater, and rendered the decolorization. After long-term of operation, it was observed that the predominant microorganisms immobilized on the BAF carriers were rod-shaped and globular. Four bacterial strains with apparent 16S rDNA fragments in the Denaturing Gradient Gel Electrophoresis (DGGE) profiles of BAF samples were identified as Variovorax sp., Sphingomonas sp., Mycobacterium sp., and Microbacterium sp.

  3. Treatment of bromoamine acid wastewater using combined process of micro-electrolysis and biological aerobic filter

    Fan Li [Shenzhen Graduate School, Peking University, Key Laboratory for Environmental and Urban Sciences, Guang Dong 518055 (China); Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China); Ni Jinren [Shenzhen Graduate School, Peking University, Key Laboratory for Environmental and Urban Sciences, Guang Dong 518055 (China); Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China)], E-mail: nijinren@iee.pku.edu.cn; Wu Yanjun; Zhang Yongyong [Shenzhen Graduate School, Peking University, Key Laboratory for Environmental and Urban Sciences, Guang Dong 518055 (China); Department of Environmental Engineering, Peking University, Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing 100871 (China)

    2009-03-15

    The wastewater originated from the production of bromoamine acid was treated in a sequential system of micro-electrolysis (ME) and biological aerobic filter (BAF). Decolorization and COD{sub Cr} removal rate of the proposed system was investigated with full consideration of the influence of two major controlling factors such as organic loading rate (OLR) and hydraulic retention time (HRT). The removal rate of COD{sub Cr} was 81.2% and that of chrominance could be up to 96.6% at an OLR of 0.56 kg m{sup -3} d{sup -1} when the total HRT was 43.4 h. Most of the chrominance was removed by the ME treatment, however, the BAF process was more effective for COD{sub Cr} removal. The GC-MS and HPLC-MS analysis of the contaminants revealed that 1-aminoanthraquinone, bromoamine acid and mono-sulfonated 1,2-dichlorobenzene were the main organic components in the wastewater. The reductive transformation of the anthraquinone derivatives in the ME reactor improved the biodegradability of the wastewater, and rendered the decolorization. After long-term of operation, it was observed that the predominant microorganisms immobilized on the BAF carriers were rod-shaped and globular. Four bacterial strains with apparent 16S rDNA fragments in the Denaturing Gradient Gel Electrophoresis (DGGE) profiles of BAF samples were identified as Variovorax sp., Sphingomonas sp., Mycobacterium sp., and Microbacterium sp.

  4. Treatment of bromoamine acid wastewater using combined process of micro-electrolysis and biological aerobic filter

    Fan Li; Ni Jinren; Wu Yanjun; Zhang Yongyong

    2009-01-01

    The wastewater originated from the production of bromoamine acid was treated in a sequential system of micro-electrolysis (ME) and biological aerobic filter (BAF). Decolorization and COD Cr removal rate of the proposed system was investigated with full consideration of the influence of two major controlling factors such as organic loading rate (OLR) and hydraulic retention time (HRT). The removal rate of COD Cr was 81.2% and that of chrominance could be up to 96.6% at an OLR of 0.56 kg m -3 d -1 when the total HRT was 43.4 h. Most of the chrominance was removed by the ME treatment, however, the BAF process was more effective for COD Cr removal. The GC-MS and HPLC-MS analysis of the contaminants revealed that 1-aminoanthraquinone, bromoamine acid and mono-sulfonated 1,2-dichlorobenzene were the main organic components in the wastewater. The reductive transformation of the anthraquinone derivatives in the ME reactor improved the biodegradability of the wastewater, and rendered the decolorization. After long-term of operation, it was observed that the predominant microorganisms immobilized on the BAF carriers were rod-shaped and globular. Four bacterial strains with apparent 16S rDNA fragments in the Denaturing Gradient Gel Electrophoresis (DGGE) profiles of BAF samples were identified as Variovorax sp., Sphingomonas sp., Mycobacterium sp., and Microbacterium sp

  5. Nitrogen removal from wastewater through microbial electrolysis cells and cation exchange membrane.

    Haddadi, Sakineh; Nabi-Bidhendi, Gholamreza; Mehrdadi, Nasser

    2014-02-17

    Vulnerability of water resources to nutrients led to progressively stricter standards for wastewater effluents. Modification of the conventional procedures to meet the new standards is inevitable. New technologies should give a priority to nitrogen removal. In this paper, ammonium chloride and urine as nitrogen sources were used to investigate the capacity of a microbial electrolysis cell (MEC) configured by cation exchange membrane (CEM) for electrochemical removal of nitrogen over open-and closed-circuit potentials (OCP and CCP) during biodegradation of organic matter. Results obtained from this study indicated that CEM was permeable to both organic and ammonium nitrogen over OCP. Power substantially mediated ammonium migration from anodic wastewater to the cathode, as well. With a urine rich wastewater in the anode, the maximum rate of ammonium intake into the cathode varied from 34.2 to 40.6 mg/L.h over CCP compared to 10.5-14.9 mg/L.h over OCP. Ammonium separation over CCP was directly related to current. For 1.46-2.12 mmol electron produced, 20.5-29.7 mg-N ammonium was removed. Current also increased cathodic pH up to 12, a desirable pH for changing ammonium ion to ammonia gas. Results emphasized the potential for MEC in control of ammonium through ammonium separation and ammonia volatilization provided that membrane characteristic is considered in their development.

  6. Pre-treatment of pyridine wastewater by new cathodic-anodic-electrolysis packing.

    Jin, Yang; Yue, Qinyan; Yang, Kunlun; Wu, Suqing; Li, Shengjie; Gao, Baoyu; Gao, Yuan

    2018-01-01

    A novel cathodic-anodic-electrolysis packing (CAEP) used in the treatment of pyridine wastewater was researched, which mainly consisted of 4,4'-diamino-2,2'-disulfonic acid (DSD acid) industrial iron sludge. The physical properties and morphology of the packing were studied. The CAEP was used in a column reactor during the pretreatment of pyridine wastewater. The influence of pH, hydraulic retention time (HRT), the air-liquid ratio (A/L) and the initial concentration of pyridine were investigated by measuring the removal of total organic carbon (TOC) and pyridine. The characterization results showed that the bulk density, grain density, water absorption percentage and specific surface area were 921kg/m 3 , 1086kg/m 3 , 25% and 29.89m 2 /g, respectively; the removal of TOC and pyridine could reach 50% and 58% at the optimal experimental conditions (pH=3, HRT=8hr, A/L=2). Notably, the surface of the packing was renewed constantly during the running of the filter, and the handling capacity was stable after running for three months. Copyright © 2017. Published by Elsevier B.V.

  7. Examination of protein degradation in continuous flow, microbial electrolysis cells treating fermentation wastewater

    Nam, Joo-Youn

    2014-11-01

    © 2014 Elsevier Ltd. Cellulose fermentation wastewaters (FWWs) contain short chain volatile fatty acids and alcohols, but they also have high concentrations of proteins. Hydrogen gas production from FWW was examined using continuous flow microbial electrolysis cells (MECs), with a focus on fate of the protein. H2 production rates were 0.49±0.05m3/m3-d for the FWW, compared to 0.63±0.02m3/m3-d using a synthetic wastewater containing only acetate (applied potential of 0.9V). Total organic matter removal was 76±6% for the FWW, compared to 87±5% for acetate. The MEC effluent became relatively enriched in protein (69%) compared to that in the original FWW (19%). Protein was completely removed using higher applied voltages (1.0 or 1.2V), but current generation was erratic due to more positive anode potentials (-113±38mV, Eap=1.2V; -338±38mV, 1.0V; -0.426±4mV, 0.9V). Bacteria on the anodes with FWW were primarily Deltaproteobacteria, while Archaea were predominantly Methanobacterium.

  8. Performance of a pilot-scale continuous flow microbial electrolysis cell fed winery wastewater.

    Cusick, Roland D; Bryan, Bill; Parker, Denny S; Merrill, Matthew D; Mehanna, Maha; Kiely, Patrick D; Liu, Guangli; Logan, Bruce E

    2011-03-01

    A pilot-scale (1,000 L) continuous flow microbial electrolysis cell was constructed and tested for current generation and COD removal with winery wastewater. The reactor contained 144 electrode pairs in 24 modules. Enrichment of an exoelectrogenic biofilm required ~60 days, which is longer than typically needed for laboratory reactors. Current generation was enhanced by ensuring adequate organic volatile fatty acid content (VFA/SCOD ≥ 0.5) and by raising the wastewater temperature (31 ± 1°C). Once enriched, SCOD removal (62 ± 20%) was consistent at a hydraulic retention time of 1 day (applied voltage of 0.9 V). Current generation reached a maximum of 7.4 A/m(3) by the planned end of the test (after 100 days). Gas production reached a maximum of 0.19 ± 0.04 L/L/day, although most of the product gas was converted to methane (86 ± 6%). In order to increase hydrogen recovery in future tests, better methods will be needed to isolate hydrogen gas produced at the cathode. These results show that inoculation and enrichment procedures are critical to the initial success of larger-scale systems. Acetate amendments, warmer temperatures, and pH control during startup were found to be critical for proper enrichment of exoelectrogenic biofilms and improved reactor performance.

  9. Potential Use of Microbial Electrolysis Cells in Domestic Wastewater Treatment Plants for Energy Recovery

    Escapa, Adrián; San-Martín, María Isabel; Morán, Antonio, E-mail: amorp@unileon.es [Chemical and Environmental Bioprocess Engineering Group, Natural Resources Institute (IRENA), University of León, León (Spain)

    2014-06-06

    Globally, large amounts of electrical energy are spent every year for domestic wastewater (dWW) treatment. In the future, energy prices are expected to rise as the demand for energy resources increases and fossil fuel reserves become depleted. By using appropriate technologies, the potential chemical energy contained in the organic compounds present in dWWs might help to improve the energy and economic balance of dWW treatment plants. Bioelectrochemical systems (BESs) in general and microbial electrolysis cells (MECs) in particular represent an emerging technology capable of harvesting part of this energy. This study offers an overview of the potential of using MEC technology in domestic wastewater treatment plants (dWWTPs) to reduce the energy bill. It begins with a brief account of the basics of BESs, followed by an examination of how MECs can be integrated in dWWTPs, identifying scaling-up bottlenecks and estimating potential energy savings. A simplified analysis showed that the use of MEC technology may help to reduce up to ~20% the energy consumption in a conventional dWWTP. The study concludes with a discussion of the future perspectives of MEC technology for dWW treatment. The growing rates of municipal water and wastewater treatment markets in Europe offer excellent business prospects and it is expected that the first generation of MECs could be ready within 1–4 years. However, before MEC technology may achieve practical implementation in dWWTPs, it need not only to overcome important techno-economic challenges, but also to compete with other energy-producing technologies.

  10. Evaluation of low cost cathode materials for treatment of industrial and food processing wastewater using microbial electrolysis cells

    Tenca, Alberto

    2013-02-01

    Microbial electrolysis cells (MECs) can be used to treat wastewater and produce hydrogen gas, but low cost cathode catalysts are needed to make this approach economical. Molybdenum disulfide (MoS2) and stainless steel (SS) were evaluated as alternative cathode catalysts to platinum (Pt) in terms of treatment efficiency and energy recovery using actual wastewaters. Two different types of wastewaters were examined, a methanol-rich industrial (IN) wastewater and a food processing (FP) wastewater. The use of the MoS2 catalyst generally resulted in better performance than the SS cathodes for both wastewaters, although the use of the Pt catalyst provided the best performance in terms of biogas production, current density, and TCOD removal. Overall, the wastewater composition was more of a factor than catalyst type for accomplishing overall treatment. The IN wastewater had higher biogas production rates (0.8-1.8 m3/m3-d), and COD removal rates (1.8-2.8 kg-COD/m3-d) than the FP wastewater. The overall energy recoveries were positive for the IN wastewater (3.1-3.8 kWh/kg-COD removed), while the FP wastewater required a net energy input of -0.7 - 1.2 kWh/kg-COD using MoS 2 or Pt cathodes, and -3.1 kWh/kg-COD with SS. These results suggest that MoS2 is the most suitable alternative to Pt as a cathode catalyst for wastewater treatment using MECs, but that net energy recovery will be highly dependent on the specific wastewater. © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

  11. A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater

    Ruihong Yang

    2016-04-01

    Full Text Available Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to be an initial pH value of 3, reaction time of 80 min, and 0.05 mol/L Na2SO4 additive concentration. The reaction mechanism of the treatment of oil refinery wastewater by Fe/C/Al micro-electrolysis was investigated. The process of the treatment of oil refinery wastewater with multiple micro-electrolysis conforms to the third-order reaction kinetics. The gas chromatography–mass spectrometry (GC–MS used to analyze the organic compounds of the oil refinery wastewater before and after treatment and the Ultraviolet–visible spectroscopy (UV–VIS absorption spectrum analyzed the degradation process of organic compounds in oil refinery wastewater. The treatment effect of Fe/C/Al multiple micro-electrolysis was examined in the continuous experiment under the optimum conditions, which showed high organic compound removal and stable treatment efficiency.

  12. A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater.

    Yang, Ruihong; Zhu, Jianzhong; Li, Yingliu; Zhang, Hui

    2016-04-29

    Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to be an initial pH value of 3, reaction time of 80 min, and 0.05 mol/L Na₂SO₄ additive concentration. The reaction mechanism of the treatment of oil refinery wastewater by Fe/C/Al micro-electrolysis was investigated. The process of the treatment of oil refinery wastewater with multiple micro-electrolysis conforms to the third-order reaction kinetics. The gas chromatography-mass spectrometry (GC-MS) used to analyze the organic compounds of the oil refinery wastewater before and after treatment and the Ultraviolet-visible spectroscopy (UV-VIS) absorption spectrum analyzed the degradation process of organic compounds in oil refinery wastewater. The treatment effect of Fe/C/Al multiple micro-electrolysis was examined in the continuous experiment under the optimum conditions, which showed high organic compound removal and stable treatment efficiency.

  13. POTENTIAL USE OF MICROBIAL ELECTROLYSIS CELLS (MECs IN DOMESTIC WASTEWATER TREATMENT PLANTS FOR ENERGY RECOVERY

    Adrian eEscapa

    2014-06-01

    Full Text Available Globally, large amounts of electrical energy are spent every year for domestic wastewater (dWW treatment. In the future, energy prices are expected to rise as the demand for energy resources increases and fossil fuel reserves become depleted. By using appropriate technologies, the potential chemical energy contained in the organic compounds present in dWWs might help to improve the energy and economic balance of dWW treatment plants. Bioelectrochemical Systems (BESs in general and microbial electrolysis cells (MECs in particular represent an emerging technology capable of harvesting part of this energy. This study offers an overview of the potential of using MEC technology in dWW treatment plants (dWWTPs to reduce the energy bill. It begins with a brief account of the basics of BESs, followed by an examination of how MECs can be integrated in dWW treatment plants (dWWTPs, identifying scaling-up bottlenecks and estimating potential energy savings. A simplified analysis showed that the use of MEC technology may help to reduce up to ~20% the energy consumption in a conventional dWWTP. The study concludes with a discussion of the future perspectives of MEC technology for dWW treatment. The growing rates of municipal water and wastewater treatment markets in Europe offer excellent business prospects and it is expected that the first generation of MECs could be ready within 1-4 years. However, before MEC technology may achieve practical implementation in dWWTPs, it needs not only to overcome important techno-economic challenges, but also to compete with other energy-producing technologies.

  14. Degradation of nitrobenzene in simulated wastewater by iron-carbon micro-electrolysis packing.

    Li, Meng; Zou, Donglei; Zou, Haochen; Fan, Dongyan

    2011-12-01

    The reductive degradation of nitrobenzene (NB) by iron-carbon micro-electrolysis packing was investigated. The influence of initial NB concentration, pH value and packing amount on the removal rate of NB were studied. The results showed that the reaction with packing followed the pseudo-first-order reaction. The optimum pH was 3.0 for the degradation of NB in the tested pH ranges of 3-9 and the optimum packing amount was 40 g/200 ml. The flow-through column packed with packing was designed to remove NB from simulated wastewater for approximately 68 days. The removal rate was over 90% within initial periods. It could be seen that after running for 68 days, the packing still had good performance after the long-term column experiment. In addition, the changes of the packing surfaces morphologies and matters before, during and after the column experiment were analysed by scanning electron microscopy in conjunction with energy-dispersion spectroscopy (EDS).

  15. A monetary comparison of energy recovered from microbial fuel cells and microbial electrolysis cells fed winery or domestic wastewaters

    Cusick, Roland D.; Kiely, Patrick D.; Logan, Bruce E. [Department of Civil and Environmental Engineering, H2E Center, Penn State University, University Park, PA 16802 (United States)

    2010-09-15

    Microbial fuel (MFCs) and electrolysis cells (MECs) can be used to recover energy directly as electricity or hydrogen from organic matter. Organic removal efficiencies and values of the different energy products were compared for MFCs and MECs fed winery or domestic wastewater. TCOD removal (%) and energy recoveries (kWh/kg-COD) were higher for MFCs than MECs with both wastewaters. At a cost of 4.51/kg-H{sub 2} for winery wastewater and 3.01/kg-H{sub 2} for domestic wastewater, the hydrogen produced using MECs cost less than the estimated merchant value of hydrogen (6/kg-H{sub 2}). 16S rRNA clone libraries indicated the predominance of Geobacter species in anodic microbial communities in MECs for both wastewaters, suggesting low current densities were the result of substrate limitations. The results of this study show that energy recovery and organic removal from wastewater are more effective with MFCs than MECs, but that hydrogen production from wastewater fed MECs can be cost effective. (author)

  16. Comparison of two modified coal ash ferric-carbon micro-electrolysis ceramic media for pretreatment of tetracycline wastewater.

    Yang, Kunlun; Jin, Yang; Yue, Qinyan; Zhao, Pin; Gao, Yuan; Wu, Suqing; Gao, Baoyu

    2017-05-01

    Application of modified sintering ferric-carbon ceramics (SFC) and sintering-free ferric-carbon ceramics (SFFC) based on coal ash and scrap iron for pretreatment of tetracycline (TET) wastewater was investigated in this article. Physical property, morphological character, toxic metal leaching content, and crystal component were studied to explore the application possibility of novel ceramics in micro-electrolysis reactors. The influences of operating conditions including influent pH, hydraulic retention time (HRT), and air-water ratio (A/W) on the removal of tetracycline were studied. The results showed that SFC and SFFC were suitable for application in micro-electrolysis reactors. The optimum conditions of SFC reactor were pH of 3, HRT of 7 h, and A/W of 10. For SFFC reactor, the optimum conditions were pH of 2, HRT of 7 h, and A/W of 15. In general, the TET removal efficiency of SFC reactor was better than that of SFFC reactor. However, the harden resistance of SFFC was better than that of SFC. Furthermore, the biodegradability of TET wastewater was improved greatly after micro-electrolysis pretreatment for both SFC and SFFC reactors.

  17. Current as an indicator of ammonia concentration during wastewater treatment in an integrated microbial electrolysis cell - Nitrification system

    Zhao, Nannan; Angelidaki, Irini; Zhang, Yifeng

    2018-01-01

    with synthetic ammonia-rich wastewater. A good linear relationship (R2 = 0.9419) was observed between current (0.5130–3.906 mA) and ammonia levels (0–62.1 mg NH4+-N/L). Such linear relationship was always obtained regardless of the tested external power supply or wastewater pH. The external electrochemical cell......A key challenge for ammonia monitoring during nitrogen removal process is the extra cost and toxic reagent consuming. Herein the feasibility of current generated by an integrated microbial electrolysis cell (MEC) - nitrification reactor as an indicator of initial ammonia levels (NH3/NH4......+) in wastewater was explored. In this loop system, ammonia was first oxidized to nitrate in the nitrification reactor, and then the effluent was introduced into the cathode of MEC where nitrate was reduced as electron acceptor. The correlation between current and ammonia concentration was first investigated...

  18. A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater

    Yang, Ruihong; ZHU, Jianzhong; Li, Yingliu; Zhang, Hui

    2016-01-01

    Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to b...

  19. Anode microbial communities produced by changing from microbial fuel cell to microbial electrolysis cell operation using two different wastewaters

    Kiely, Patrick D.; Cusick, Roland; Call, Douglas F.; Selembo, Priscilla A.; Regan, John M.; Logan, Bruce E.

    2011-01-01

    Conditions in microbial fuel cells (MFCs) differ from those in microbial electrolysis cells (MECs) due to the intrusion of oxygen through the cathode and the release of H2 gas into solution. Based on 16S rRNA gene clone libraries, anode communities in reactors fed acetic acid decreased in species richness and diversity, and increased in numbers of Geobacter sulfurreducens, when reactors were shifted from MFCs to MECs. With a complex source of organic matter (potato wastewater), the proportion of Geobacteraceae remained constant when MFCs were converted into MECs, but the percentage of clones belonging to G. sulfurreducens decreased and the percentage of G. metallireducens clones increased. A dairy manure wastewater-fed MFC produced little power, and had more diverse microbial communities, but did not generate current in an MEC. These results show changes in Geobacter species in response to the MEC environment and that higher species diversity is not correlated with current. © 2010 Elsevier Ltd.

  20. Effect of the type of ion exchange membrane on performance, ion transport, and pH in biocatalyzed electrolysis of wastewater

    Rozendal, R.A.; Sleutels, T.H.J.A.; Hamelers, H.V.M.; Buisman, C.J.N.

    2008-01-01

    Previous studies have shown that the application of cation exchange membranes (CEMs) in bioelectrochemical systems running on wastewater can cause operational problems. In this paper the effect of alternative types of ion exchange membrane is studied in biocatalyzed electrolysis cells. Four types of

  1. Energy-positive wastewater treatment and desalination in an integrated microbial desalination cell (MDC)-microbial electrolysis cell (MEC)

    Li, Yan; Styczynski, Jordyn; Huang, Yuankai; Xu, Zhiheng; McCutcheon, Jeffrey; Li, Baikun

    2017-07-01

    Simultaneous removal of nitrogen in municipal wastewater, metal in industrial wastewater and saline in seawater was achieved in an integrated microbial desalination cell-microbial electrolysis cell (MDC-MEC) system. Batch tests showed that more than 95.1% of nitrogen was oxidized by nitrification in the cathode of MDC and reduced by heterotrophic denitrification in the anode of MDC within 48 h, leading to the total nitrogen removal rate of 4.07 mg L-1 h-1. Combining of nitrogen removal and desalination in MDC effectively solved the problem of pH fluctuation in anode and cathode, and led to 63.7% of desalination. Power generation of MDC (293.7 mW m-2) was 2.9 times higher than the one without salt solution. The electric power of MDC was harvested by a capacitor circuit to supply metal reduction in a MEC, and 99.5% of lead (II) was removed within 48 h. A kinetic MDC model was developed to elucidate the correlation of voltage output and desalination efficiency. Ratio of wastewater and sea water was calculated for MDC optimal operation. Energy balance of nutrient removal, metal removal and desalination in the MDC-MEC system was positive (0.0267 kW h m-3), demonstrating the promise of utilizing low power output of MDCs.

  2. Micro-electrolysis/retinervus luffae-based simultaneous autotrophic and heterotrophic denitrification for low C/N wastewater treatment.

    Li, Jinlong; Li, Desheng; Cui, Yuwei; Xing, Wei; Deng, Shihai

    2017-07-01

    Nitrogen bioremediation in organic insufficient wastewater generally requires an extra carbon source. In this study, nitrate-contaminated wastewater was treated effectively through simultaneous autotrophic and heterotrophic denitrification based on micro-electrolysis carriers (MECs) and retinervus luffae fructus (RLF), respectively. The average nitrate and total nitrogen removal rates reached 96.3 and 94.0% in the MECs/RLF-based autotrophic and heterotrophic denitrification (MRAHD) system without ammonia and nitrite accumulation. The performance of MRAHD was better than that of MEC-based autotrophic denitrification for the wastewater treatment with low carbon nitrogen (COD/N) ratio. Real-time quantitative polymerase chain reaction (qPCR) revealed that the relative abundance of nirS-type denitrifiers attached to MECs (4.9%) and RLF (5.0%) was similar. Illumina sequencing suggested that the dominant genera were Thiobacillus (7.0%) and Denitratisoma (5.7%), which attached to MECs and RLF, respectively. Sulfuritalea was discovered as the dominant genus in the middle of the reactor. The synergistic interaction between autotrophic and heterotrophic denitrifiers played a vital role in the mixotrophic substrate environment.

  3. Application for oxytetracycline wastewater pretreatment by Fenton iron mud based cathodic-anodic-electrolysis ceramic granular fillers.

    Zhang, Feilong; Yue, Qinyan; Gao, Yuan; Gao, Baoyu; Xu, Xing; Ren, Zhongfei; Jin, Yang

    2017-09-01

    In this study, Fenton iron mud applied as main raw material of cathodic-anodic-electrolysis ceramic granular fillers (ICMF) in a continuous reactor, which were used to pretreat oxytetracycline (OTC) wastewater. The ICMF was characterized by Scanning Electron Microscope and Energy Dispersive Spectrometer analysis. The effects of pH value, hydraulic retention time, OTC concentrations and aeration on removal efficiency of total organic carbon (TOC) and OTC were studied. The degradation byproducts of OTC were analyzed by UV-2450, High Performance Liquid Chromatography and Liquid Chromatography-mass Spectrometry. The SEM images showed that the surface ICMF was porous. This system had a higher stability, and good removal efficiency of TOC of 80.5% and OTC of 98.5% under the optimal conditions, which were influent pH of 3, HRT of 4 h, and anaerobic condition. After running for 60 d, the removal efficiency of TOC was stable and the ICMF did not become hardened. The reactor was back washed by acid solution (pH: 1) in 20 d approximately. This paper provides useful information for approaching in wastewater pretreatment and recycling the Fenton iron mud. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Examination of protein degradation in continuous flow, microbial electrolysis cells treating fermentation wastewater

    Nam, Joo-Youn; Yates, Matthew D.; Zaybak, Zehra; Logan, Bruce E.

    2014-01-01

    © 2014 Elsevier Ltd. Cellulose fermentation wastewaters (FWWs) contain short chain volatile fatty acids and alcohols, but they also have high concentrations of proteins. Hydrogen gas production from FWW was examined using continuous flow microbial

  5. Recovery of copper and water from copper-electroplating wastewater by the combination process of electrolysis and electrodialysis.

    Peng, Changsheng; Liu, Yanyan; Bi, Jingjing; Xu, Huizhen; Ahmed, Abou-Shady

    2011-05-30

    In this paper, a laboratory-scale process which combined electrolysis (EL) and electrodialysis (ED) was developed to treat copper-containing wastewater. The feasibility of such process for copper recovery as well as water reuse was determined. Effects of three operating parameters, voltage, initial Cu(2+) concentration and water flux on the recovery of copper and water were investigated and optimized. The results showed that about 82% of copper could be recovered from high concentration wastewater (HCW, >400mg/L) by EL, at the optimal conditions of voltage 2.5 V/cm and water flux 4 L/h; while 50% of diluted water could be recycled from low concentration wastewater (LCW, water flux 4 L/h. However, because of the limitation of energy consumption (EC), LCW for EL and HCW for ED could not be treated effectively, and the effluent water of EL and concentrated water of ED should be further treated before discharged. Therefore, the combination process of EL and ED was developed to realize the recovery of copper and water simultaneously from both HCW and LCW. The results of the EL-ED process showed that almost 99.5% of copper and 100% of water could be recovered, with the energy consumption of EL ≈ 3 kW h/kg and ED ≈ 2 kW h/m(3). According to SEM and EDX analysis, the purity of recovered copper was as high as 97.9%. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Efficient treatment of aniline containing wastewater in bipolar membrane microbial electrolysis cell-Fenton system

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan

    2017-01-01

    wastewater under an acidic condition maintained by the bipolar membrane. The aniline was effectively degraded following first-order kinetics at a rate constant of 0.0166 h−1 under an applied voltage of 0.5 V. Meanwhile, a total organic carbon (TOC) removal efficiency of 93.1 ± 1.2% was obtained, revealing...

  7. Degradation of phenol and Cr (VI) wastewater with contact glow discharge electrolysis method and the addition of Fe2+

    Kurniawan, Raden Ridzki Aditya; Saksono, Nelson

    2017-11-01

    Phenol and Cr (VI) are an organic waste and dangerous heavy metals which generated from a wide variety of industrial processes such as textiles, paints, dyes, and others. For that reason, we need effective waste treatment technologies, one of them is Contact Glow Discharge Electrolysis (CGDE). This method produce reactive species such as radical hidroxyl so as to be able to degradate phenol and Cr(VI) wastewater effectively. This research aims to obtain the effect of Fe 2+ and air bubbles in degradation of phenol and Cr (VI) waste simultaneously. Waste degradation is measured its absorbance with UV-Vis spectrophotometer. In the conditions of 600 Volt voltage, Na2SO4 0.02 M, anode depth of 1.5 cm, the addition of Fe2+ 40 ppm and the addition of air bubbles for 30 minutes was obtained a percentage degradation of phenol 99.47%, Cr (VI) 76.75% and specific energy of 344.473 kJ / mmol.

  8. Enhanced anaerobic degradation of Fischer-Tropsch wastewater by integrated UASB system with Fe-C micro-electrolysis assisted.

    Wang, Dexin; Ma, Wencheng; Han, Hongjun; Li, Kun; Xu, Hao; Fang, Fang; Hou, Baolin; Jia, Shengyong

    2016-12-01

    Coupling of the Fe-C micro-electrolysis (IC-ME) into the up-flow anaerobic sludge blanket (UASB) was developed for enhanced Fischer-Tropsch wastewater treatment. The COD removal efficiency and methane production in R 3 with IC-ME assisted both reached up to 80.6 ± 1.7% and 1.38 ± 0.11 L/L·d that higher than those values in R 1 with GAC addition (63.0 ± 3.4% and 0.95 ± 0.09 L/L·d) and R 2 with ZVI addition (74.5 ± 2.8% and 1.21 ± 0.09 L/L·d) under the optimum HRT (5 d). The Fe corrosion as electron donor reduced the ORP values and stimulated the activities of hydrogenotrophic methanogens to lower H 2 partial pressure in R 2 and R 3 . Additionally, Fe 2+ as by-product of iron corrosion, its presence could effectively increase the percentage of protein content in tightly bound extracellular polymeric substances (TB-EPS) to promote better bioflocculation, increasing to 90.5 mg protein/g·VSS (R 2 ) and 106.3 mg protein/g·VSS (R 3 ) while this value in R1 was simply 56.6 mg protein/g·VSS. More importantly, compared with R 1 , the excess accumulation of propionic acid and butyric acid in system was avoided. The macroscopic galvanic cells around Fe-C micro-electrolysis carriers in R 3 , that larger than microscopic galvanic cells in R 2 , further accelerate to transfer the electrons from anodic Fe to cathodic carbon that enhance interspecies hydrogen transfer, making the decomposition of propionic acid and butyric acid more thermodynamically feasible, finally facilitate more methane production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Enhanced degradation of phenolic compounds in coal gasification wastewater by a novel integration of micro-electrolysis with biological reactor (MEBR) under the micro-oxygen condition.

    Ma, Weiwei; Han, Yuxing; Xu, Chunyan; Han, Hongjun; Ma, Wencheng; Zhu, Hao; Li, Kun; Wang, Dexin

    2018-03-01

    The aim of this work was to study an integration of micro-electrolysis with biological reactor (MEBR) for strengthening removal of phenolic compounds in coal gasification wastewater (CGW). The results indicated MEBR achieved high efficiencies in removal of COD and phenolic compounds as well as improvement of biodegradability of CGW under the micro-oxygen condition. The integrated MEBR process was more favorable to improvement of the structural stability of activated sludge and biodiversity of specific functional microbial communities. Especially, Shewanella and Pseudomonas were enriched to accelerate the extracellular electron transfer, finally facilitating the degradation of phenolic compounds. Moreover, MEBR process effectively relieved passivation of Fe-C filler surface and prolonged lifespan of Fe-C filler. Accordingly, the synergetic effect between iron-carbon micro-electrolysis (ICME) and biological action played a significant role in performance of the integrated process. Therefore, the integrated MEBR was a promising practical process for enhancing CGW treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Treatment of simulated wastewater containing n-phenyl-n-isopropyl-p-phenylenediamine using electrolysis system with Ti/TiRuO2 electrodes

    Thelma Helena Inazaki

    2004-11-01

    Full Text Available This study investigated the effects of the electrolytic treatment in the simulated wastewater with aromatic amine n-phenyl-n-isopropyl-p-phenylenediamine (Flexzone 3P® using Ti/TiRuO2 electrodes under 0.025 A/cm² (DC for different electrolysis durations (5; 15; 30; 45 and 60 min. Conductivity, pH, UV-visible spectra, gas chromatograms, toxicity and biodegradation tests were carried out. During the electrolytic treatment the pH decreased and conductivity increased slightly. After 60 min of electrolysis, the concentration of Flexzone 3P decreased by 65.1%. UV-vis spectra and chromatograms of simulated wastewater showed changes in the molecular structure of the aromatic amine. After 5 and 15 min of electrolysis, the simulated wastewater containing the Flexzone 3P showed detoxification by Saccharomyces cerevisiae toxicity test. The electrolysis of 5 min improved the biodegradation of the simulated wastewater containing Flexzone 3P.O presente trabalho apresenta os resultados dos tratamentos eletrolíticos (05; 15; 30; 45 e 60 min no efluente simulado com o composto Flexzone 3P, utilizando-se eletrodos de Ti/TiRuO2, sob 0,025 A cm-2. Após as eletrólises, foram feitas análises de pH, condutividade, espectrofotometria no UV-vis, análise por cromatografia gasosa, ensaios de toxicidade utilizando Saccharomyces cerevisiae e ensaio de respirometria de Bartha. O pH dos efluentes foi diminuindo à medida que aumentou- se o tempo de eletrólise, ao contrário da condutividade, a qual apresentou pequeno aumento. Verificou-se que após 60 min de tratamento foi obtida diminuição da concentração do composto Flexzone 3P em 65,1%. Analisando-se os espectros de UV-vis e cromatogramas do efluente após realização do tratamento eletrolítico, concluiu-se que ocorreram oxidações e transformações de funções orgânicas do composto, durante os tratamentos. Após a realização do tratamento eletrolítico, o efluente simulado apresentou diminuição da

  11. Integrated Microbial Electrolysis Cell (MEC) with an anaerobic Membrane Bioreactor (MBR) for low strength wastewater treatment, energy harvesting and water reclamation

    Jimenez Sandoval, Rodrigo J.

    2013-11-01

    Shortage of potable water is a problem that affects many nations in the world and it will aggravate in a near future if pertinent actions are not carried out. Decrease in consumption, improvements in water distribution systems to avoid losses and more efficient water treatment processes are some actions that can be implemented to attack this problem. Membrane technology and biological processes are used in wastewater treatment to achieve high water quality standards. Some other technologies, besides water treatment, attempt to obtain energy from organic wastes present in water. In this study, a proof-of-concept was accomplished demonstrating that a Microbial Electrolysis Cell can be fully integrated with a Membrane Bioreactor to achieve wastewater treatment and harvest energy. Conductive hollow fiber membranes made of nickel functioned as both filter material for treated water reclamation and as a cathode to catalyze hydrogen production reaction. The produced hydrogen was subsequently converted into methane by hydrogenotrophic methanogens. Organic removal was 98.9% irrespective of operation mode. Maximum volumetric hydrogen production rate was 0.2 m3/m3d, while maximum current density achieved was 6.1 A/m2 (based on cathode surface area). Biofouling, an unavoidable phenomenon in traditional MBRs, can be minimized in this system through self-cleaning approach of hybrid membranes by hydrogen production. The increased rate of hydrogen evolution at high applied voltage (0.9 V) reduces the membrane fouling. Improvements can be done in the system to make it as a promising net energy positive technology for the low strength wastewater treatment.

  12. Environmental quality assessment of reservoirs impacted by Hg from chlor-alkali technologies: case study of a recovery.

    Le Faucheur, Séverine; Vasiliu, Dan; Catianis, Irina; Zazu, Mariana; Dranguet, Perrine; Beauvais-Flück, Rebecca; Loizeau, Jean-Luc; Cosio, Claudia; Ungureanu, Costin; Ungureanu, Viorel Gheorghe; Slaveykova, Vera I

    2016-11-01

    Mercury (Hg) pollution legacy of chlor-alkali plants will be an important issue in the next decades with the planned phase out of Hg-based electrodes by 2025 within the Minamata convention. In such a context, the present study aimed to examine the extent of Hg contamination in the reservoirs surrounding the Oltchim plant and to evaluate the possible improvement of the environmental quality since the closure of its chlor-alkali unit. This plant is the largest chlor-alkali plant in Romania, which partly switched to Hg-free technology in 1999 and definitely stopped the use of Hg electrolysis in May 2012. Total Hg (THg) and methylmercury (CH 3 Hg) concentrations were found to decrease in the surface waters and sediments of the reservoirs receiving the effluents of the chlor-alkali platform since the closure of Hg units. Hence, calculated risk quotients (RQ) indicated no adverse effect of Hg for aquatic organisms from the ambient water exposure. RQ of Hg in sediments were mostly all higher than 1, showing important risks for benthic organisms. However, ecotoxicity testing of water and sediments suggest possible impact of other contaminants and their mixtures. Hg hotspots were found in soils around the platform with RQ values much higher than 1. Finally, THg and CH 3 Hg concentrations in fish were below the food safety limit set by the WHO, which contrasts with previous measurements made in 2007 revealing that 92 % of the studied fish were of high risk of consumption. Discontinuing the use of Hg electrodes greatly improved the surrounding environment of chlor-alkali plants within the following years and led to the decrease environmental exposure to Hg through fish consumption. However, sediment and soil still remained highly contaminated and problematic for the river reservoir management. The results of this ecological risk assessment study have important implications for the evaluation of the benefits as well as limits of the Minamata Convention implementation.

  13. Enhanced treatment of Fischer-Tropsch wastewater using up-flow anaerobic sludge blanket system coupled with micro-electrolysis cell: A pilot scale study.

    Wang, Dexin; Han, Yuxing; Han, Hongjun; Li, Kun; Xu, Chunyan

    2017-08-01

    The coupling of micro-electrolysis cell (MEC) with an up-flow anaerobic sludge blanket (UASB) system in pilot scale was established for enhanced treatment of Fischer-Tropsch (F-T) wastewater. The lowest influent pH (4.99±0.10) and reduced alkali addition were accomplished under the assistance of anaerobic effluent recycling of 200% (stage 5). Simultaneously, the optimum COD removal efficiency (93.5±1.6%) and methane production (2.01±0.13m 3 /m 3 ·d) at the lower hydraulic retention time (HRT) were achieved in this stage. In addition, the dissolved iron from MEC could significantly increase the protein content of tightly bound extracellular polymeric substances (TB-EPS), which was beneficial to formation of stable granules. Furthermore, the high-throughput 16S rRNA gene pyrosequencing in this study further confirmed that Geobacter species could utilize iron oxides particles as electron conduit to perform the direct interspecies electron transfer (DIET) with Methanothrix, finally facilitating the syntrophic degradation of propionic acid and butyric acid and contributing completely methane production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Microbial nitrate removal in biologically enhanced treated coal gasification wastewater of low COD to nitrate ratio by coupling biological denitrification with iron and carbon micro-electrolysis.

    Zhang, Zhengwen; Han, Yuxing; Xu, Chunyan; Ma, Wencheng; Han, Hongjun; Zheng, Mengqi; Zhu, Hao; Ma, Weiwei

    2018-04-21

    Mixotrophic denitrification coupled biological denitrification with iron and carbon micro-electrolysis (IC-ME) is a promising emerging bioprocess for nitrate removal of biologically enhanced treated coal gasification wastewater (BECGW) with low COD to nitrate ratio. TN removal efficiency in R1 with IC-ME assisted was 16.64% higher than R2 with scrap zero valent iron addition, 23.05% higher than R3 with active carbon assisted, 30.51% higher than R4 with only active sludge addition, 80.85% higher than R5 utilizing single IC-ME as control. Fe 2+ generated from IC-ME decreased the production of N 2 O and enriched more Nitrate-reducing Fe(Ⅱ) oxidation bacteria (NRFOB) Acidovorax and Thiobacillus, which could convert nitrate to nitrogen gas. And the presence of Fe 3+ , as the Fe 2+ oxidation product, could stimulate the growth of Fe(III)-reducing strain (FRB) that indicated by redundancy analysis. Microbial network analysis demonstrated FRB Geothrix had a co-occurrence relationship with other bacteria, revealing its dominant involvement in nitrate removal of BECGW. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Life cycle assessment of solid waste management strategies in a chlor-alkali production facility.

    Muñoz, Edmundo; Navia, Rodrigo

    2011-06-01

    The waste management of a chlor-alkali and calcium chloride industrial facility from southern Chile was the object of this study. The main solid waste materials generated in these processes are brine sediments and calcium chloride sediments, respectively. Both residues are mixed in the liquid phase and filtered in a press filter, obtaining a final low humidity solid waste, called 'mixed sediments', which is disposed of in an industrial landfill as non-hazardous waste. The aim of the present study was to compare by means of LCA, the current waste management option of the studied chlor-alkali facility, namely landfill disposal, with two new possible options: the reuse of the mixed sediments as mineral additive in compost and the use of brine sediments as an unconventional sorbent for the removal of heavy metals from wastewater. The functional unit was defined as 1 tonne of waste being managed. To perform this evaluation, software SimaPro 7.0 was used, selecting the Ecoindicator 99 and CML 2000 methodologies for impact evaluation. The obtained results indicate that the use of brine sediments as a novel material for the removal of heavy metals from wastewater (scenario 3) presented environmental benefits when compared with the waste management option of sediments landfilling (scenario 1). The avoided environmental loads, generated by the substitution of activated granular carbon and the removal of Cu and Zn from wastewater in the treatment process generated positive environmental impacts, enhancing the environmental performance of scenario 3.

  16. Eletrólise de resíduos poluidores: I - Efluente de uma indústria liofilizadora de condimentos Electrolysis of polluting wastes: I - Wastewater from a seasoning freeze-drying industry

    Dejanira F. de Angelis

    1998-02-01

    Full Text Available Wastewater from a seasoning freeze-drying industry was electrolysed to increase its biodegradability. Stainless-steel electrodes were used at 9.09 A/m², for up to 80 min. Conductivity, pH, biochemical (BOD and chemical (COD oxygen demands, Daphnia similis acute toxicity bioassays, and bacteria counting through the plate count agar method were determined after different times of electrolysis. The results (e.g. higher BOD and lower COD showed that the biodegradability of the wastewater was significantly increased; furthermore, Fe2+ ions liberated by the electrodes cause microorganisms to die and, when oxidised to Fe3+, contribute for the flocculation and sedimentation of solid residues.

  17. A novel bio-electrochemical system with sand/activated carbon separator, Al anode and bio-anode integrated micro-electrolysis/electro-flocculation cost effectively treated high load wastewater with energy recovery.

    Gao, Changfei; Liu, Lifen; Yang, Fenglin

    2018-02-01

    A novel bio-electrochemical system (BES) was developed by integrating micro-electrolysis/electro-flocculation from attaching a sacrificing Al anode to the bio-anode, it effectively treated high load wastewater with energy recovery (maximum power density of 365.1 mW/m 3 and a maximum cell voltage of 0.97 V), and achieving high removals of COD (>99.4%), NH 4 + -N (>98.7%) and TP (>98.6%). The anode chamber contains microbes, activated carbon (AC)/graphite granules and Al anode. It was separated from the cathode chamber containing bifunctional catalytic and filtration membrane cathode (loaded with Fe/Mn/C/F/O catalyst) by a multi-medium chamber (MMC) filled with manganese sand and activated carbon granules, which replaced expensive PEM and reduced cost. An air contact oxidation bed for aeration was still adopted before liquid entering the cathode chamber. micro-electrolysis/electro-flocculation helps in achieving high removal efficiencies and contributes to membrane fouling migration. The increase of activated carbon in the separator MMC increased power generation and reduced system electric resistance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Water electrolysis

    Schubert, Franz H. (Inventor); Grigger, David J. (Inventor)

    1992-01-01

    This disclosure is directed to an electrolysis cell forming hydrogen and oxygen at space terminals. The anode terminal is porous and able to form oxygen within the cell and permit escape of the gaseous oxygen through the anode and out through a flow line in the presence of backpressure. Hydrogen is liberated in the cell at the opposing solid metal cathode which is permeable to hydrogen but not oxygen so that the migratory hydrogen formed in the cell is able to escape from the cell. The cell is maintained at an elevated pressure so that the oxygen liberated by the cell is delivered at elevated pressure without pumping to raise the pressure of the oxygen.

  19. High Temperature Electrolysis

    Elder, Rachael; Cumming, Denis; Mogensen, Mogens Bjerg

    2015-01-01

    High temperature electrolysis of carbon dioxide, or co-electrolysis of carbon dioxide and steam, has a great potential for carbon dioxide utilisation. A solid oxide electrolysis cell (SOEC), operating between 500 and 900. °C, is used to reduce carbon dioxide to carbon monoxide. If steam is also i...

  20. CHARACTERIZATION OF MERCURY EMISSIONS AT A CHLOR-ALKALI PLANT, VOLUME II. APPENDICES F-J

    The report gives results of a characterization of mercury (Hg) emissions at a chlor-alkali plant. Up to 160 short tons (146 Mg) of Hg is consumed by the chlor-alkali industry each year. Very little quantitative information is currently available however, on the actual Hg losses f...

  1. Principle and perspectives of hydrogen production through biocatalyzed electrolysis

    Rozendal, R.A.; Hamelers, H.V.M.; Euverink, G.J.W.; Metz, S.J.; Buisman, C.J.N.

    2006-01-01

    Biocatalyzed electrolysis is a novel biological hydrogen production process with the potential to efficiently convert a wide range of dissolved organic materials in wastewaters. Even substrates formerly regarded to be unsuitable for hydrogen production due to the endothermic nature of the involved

  2. Hydrogen by water electrolysis

    Anon.

    1995-01-01

    Hydrogen production by water electrolysis (aqueous solution of potassium hydroxide) is shortly presented with theoretical aspects (thermodynamics and kinetics), and components of the electrolytic cell (structural materials, cathodes, anodes, diaphragms), and examples of industrial processes. (A.B.). 4 figs

  3. ANTITRUST REGULATION IN TERMS OF ENTERPRISE DEVELOPMENT CHLOR-ALKALI INDUSTRY

    N. N. Grinyov

    2014-01-01

    Full Text Available The article reveals the problems of antitrust regulation activities of processing enterprises. The necessity of improving the activity of enforcement to prevent the emergence of monopolistic market structures chlor-alkali industry.

  4. Electrolysis with diamond anodes: Eventually, there are refractory species!

    Mena, Ismael F; Cotillas, Salvador; Díaz, Elena; Sáez, Cristina; Rodríguez, Juan J; Cañizares, P; Mohedano, Ángel F; Rodrigo, Manuel A

    2018-03-01

    In this work, synthetic wastewater polluted with ionic liquid 1-butyl-3-methylimidazolium (Bmim) bis(trifluoromethanesulfonyl)imide (NTf 2 ) undergoes four electrolytic treatments with diamond anodes (bare electrolysis, electrolysis enhanced with peroxosulfate promoters, irradiated with UV light and with US) and results obtained were compared with those obtained with the application of Catalytic Wet Peroxide Oxidation (CWPO). Despite its complex heterocyclic structure, Bmim + cation is successfully depleted with the five technologies tested, being transformed into intermediates that eventually can be mineralized. Photoelectrolysis attained the lowest concentration of intermediates, while CWPO is the technology less efficient in their degradation. However, the most surprising result is that concentration of NTf 2 - anion does not change during the five advanced oxidation processes tested, pointing out its strong refractory character, being the first species that exhibits this character in wastewater undergoing electrolysis with diamond. This means that the hydroxyl and sulfate radicals mediated oxidation and the direct electrolysis are inefficient for breaking the C-S, C-F and S-N bounds of the NTf 2 - anion, which is a very interesting mechanistic information to understand the complex processes undergone in electrolysis with diamond. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Electrolysis apparatus and method

    1975-01-01

    A procedure in which electrolysis is combined with radiolysis to improve the reaction yield is proposed for the production of hydrogen and oxygen from water. An apparatus for this procedure is disclosed. High-energy electric pulses are applied between the anode and kathode of an electrolytical cell in such a way that short-wave electromagnetic radiation is generated at the same time

  6. CHARACTERIZATION OF MERCURY EMISSIONS AT A CHLOR-ALKALI PLANT, VOLUME I. REPORT AND APPENDICES A-E

    The report gives results of a characterization of mercury (Hg) emissions at a chlor-alkali plant. Up to 160 short tons (146 Mg) of Hg is consumed by the chlor-alkali industry each year. Very little quantitative information is currently available however, on the actual Hg losses f...

  7. Advanced alkaline water electrolysis

    Marini, Stefania; Salvi, Paolo; Nelli, Paolo; Pesenti, Rachele; Villa, Marco; Berrettoni, Mario; Zangari, Giovanni; Kiros, Yohannes

    2012-01-01

    A short review on the fundamental and technological issues relevant to water electrolysis in alkaline and proton exchange membrane (PEM) devices is given. Due to price and limited availability of the platinum group metal (PGM) catalysts they currently employ, PEM electrolyzers have scant possibilities of being employed in large-scale hydrogen production. The importance and recent advancements in the development of catalysts without PGMs are poised to benefit more the field of alkaline electrolysis rather than that of PEM devices. This paper presents our original data which demonstrate that an advanced alkaline electrolyzer with performances rivaling those of PEM electrolyzers can be made without PGM and with catalysts of high stability and durability. Studies on the advantages/limitations of electrolyzers with different architectures do show how a judicious application of pressure differentials in a recirculating electrolyte scheme helps reduce mass transport limitations, increasing efficiency and power density.

  8. Highly efficient high temperature electrolysis

    Hauch, Anne; Ebbesen, Sune; Jensen, Søren Højgaard

    2008-01-01

    High temperature electrolysis of water and steam may provide an efficient, cost effective and environmentally friendly production of H-2 Using electricity produced from sustainable, non-fossil energy sources. To achieve cost competitive electrolysis cells that are both high performing i.e. minimum...... internal resistance of the cell, and long-term stable, it is critical to develop electrode materials that are optimal for steam electrolysis. In this article electrolysis cells for electrolysis of water or steam at temperatures above 200 degrees C for production of H-2 are reviewed. High temperature...... electrolysis is favourable from a thermodynamic point of view, because a part of the required energy can be supplied as thermal heat, and the activation barrier is lowered increasing the H-2 production rate. Only two types of cells operating at high temperature (above 200 degrees C) have been described...

  9. Treatment of high salt oxidized modified starch waste water using micro-electrolysis, two-phase anaerobic aerobic and electrolysis for reuse

    Yi, Xuenong; Wang, Yulin

    2017-06-01

    A combined process of micro-electrolysis, two-phase anaerobic, aerobic and electrolysis was investigated for the treatment of oxidized modified starch wastewater (OMSW). Optimum ranges for important operating variables were experimentally determined and the treated water was tested for reuse in the production process of corn starch. The optimum hydraulic retention time (HRT) of micro-electrolysis, methanation reactor, aerobic process and electrolysis process were 5, 24, 12 and 3 h, respectively. The addition of iron-carbon fillers to the acidification reactor was 200 mg/L while the best current density of electrolysis was 300 A/m2. The biodegradability was improved from 0.12 to 0.34 by micro-electrolysis. The whole treatment was found to be effective with removal of 96 % of the chemical oxygen demand (COD), 0.71 L/day of methane energy recovery. In addition, active chlorine production (15,720 mg/L) was obtained by electrolysis. The advantage of this hybrid process is that, through appropriate control of reaction conditions, effect from high concentration of salt on the treatment was avoided. Moreover, the process also produced the material needed in the production of oxidized starch while remaining emission-free and solved the problem of high process cost.

  10. CHARACTERIZATION OF THE FUGITIVE MERCURY EMISSIONS AT A CHLOR-ALKALI PLANT. OVERALL STUDY DESIGN

    The paper discusses a detailed emissions measurement campaign that was conducted over a 9-day period within a mercury (Hg) cell chlor-alkali plant in the southeastern United States (U.S.). The principal focus of this study was to measure fugitive (non-ducted) airborne Hg emission...

  11. Evaluation Of Demercurization Efficiency Of Chlor-Alkali Production In Pavlodar City, Kazakhstan

    Mercury pollution in Pavlodar, a city in northeastern Kazakhstan, is the result of chlor-alkali chemical plant operations in 1975-1993, where chlorine production capacity was approximately 100,000 tons per year. The total quantity of metallic mercury released into the environmen...

  12. Mercury Pollution Near A Chlor-Alkali Plant In Northern Kazakhstan

    In northern Kazakhstan, there is a serious case of mercury pollution near Pavlodar City from an old mercury cell chlor-alkali plant. The soil, sediment, and water is contaminated with more than a thousand tons of mercury and mercury compounds as a result of the operation of the ...

  13. CHARACTERIZATION OF MERCURY EMISSIONS AT A CHLOR-ALKALI PLANT: STUDY ORGANIZATION AND IMPLEMENTATION

    The paper describes the organization and implementation of a detailed emissions measurement campaign conducted over a 2-week period at the Olin Corporation's mercury chlor-alkali plant in Augusta, GA. (NOTE: Since data analysis is continuing, study results will be provided later...

  14. Hydrogen Generation From Electrolysis

    Steven Cohen; Stephen Porter; Oscar Chow; David Henderson

    2009-03-06

    Small-scale (100-500 kg H2/day) electrolysis is an important step in increasing the use of hydrogen as fuel. Until there is a large population of hydrogen fueled vehicles, the smaller production systems will be the most cost-effective. Performing conceptual designs and analyses in this size range enables identification of issues and/or opportunities for improvement in approach on the path to 1500 kg H2/day and larger systems. The objectives of this program are to establish the possible pathways to cost effective larger Proton Exchange Membrane (PEM) water electrolysis systems and to identify areas where future research and development efforts have the opportunity for the greatest impact in terms of capital cost reduction and efficiency improvements. System design and analysis was conducted to determine the overall electrolysis system component architecture and develop a life cycle cost estimate. A design trade study identified subsystem components and configurations based on the trade-offs between system efficiency, cost and lifetime. Laboratory testing of components was conducted to optimize performance and decrease cost, and this data was used as input to modeling of system performance and cost. PEM electrolysis has historically been burdened by high capital costs and lower efficiency than required for large-scale hydrogen production. This was known going into the program and solutions to these issues were the focus of the work. The program provided insights to significant cost reduction and efficiency improvement opportunities for PEM electrolysis. The work performed revealed many improvement ideas that when utilized together can make significant progress towards the technical and cost targets of the DOE program. The cell stack capital cost requires reduction to approximately 25% of today’s technology. The pathway to achieve this is through part count reduction, use of thinner membranes, and catalyst loading reduction. Large-scale power supplies are available

  15. Water electrolysis system

    Mizoguchi, Tadao; Ikehara, Masahisa; Kataoka, Noboru; Ueno, Syuichi; Ishikawa, Nobuhide.

    1996-01-01

    Nissho Iwai Co. and Ebara Co. received an order for hydrogen and oxygen generating system (water electrolysis system) to be installed at Tokai-2 power station of The Japan Atomic Power Company, following the previous order at Tsuruga-1 where the gas injection from FY1996 is planned. Hydrogen gas generated by the system will be injected to coolant of boiling water reactors to improve corrosive environment. The system is being offered by a tripartite party, Nissho Iwai, Ebara, and Norsk Hydro Electrolysers of Norway (NHEL). NHEL provides a electrolyser unit, as a core of the system. Ebara provides procurement, installation, and inspection as well as total engineering work, under the basic design by NHEL which has over 60 years-experience in this field. (author)

  16. Biofilm composition in the Olt River (Romania) reservoirs impacted by a chlor-alkali production plant.

    Dranguet, P; Cosio, C; Le Faucheur, S; Hug Peter, D; Loizeau, J-L; Ungureanu, V-Gh; Slaveykova, V I

    2017-05-24

    Freshwater biofilms can be useful indicators of water quality and offer the possibility to assess contaminant effects at the community level. The present field study examines the effects of chlor-alkali plant effluents on the community composition of biofilms grown in the Olt River (Romania) reservoirs. The relationship between ambient water quality variables and community composition alterations was explored. Amplicon sequencing revealed a significant modification of the composition of microalgal, bacterial and fungal communities in the biofilms collected in the impacted reservoirs in comparison with those living in the uncontaminated control reservoir. The abundance corrected Simpson index showed lower richness and diversity in biofilms collected in the impacted reservoirs than in the control reservoir. The biofilm bacterial communities of the impacted reservoirs were characterized by the contaminant-tolerant Cyanobacteria and Bacteroidetes, whereas microalgal communities were predominantly composed of Bacillariophyta and fungal communities of Lecanoromycetes and Paraglomycetes. A principal component analysis revealed that major contaminants present in the waste water of the chlor-alkali production plant, i.e. Na + , Ca 2+ , Cl - and Hg, were correlated with the alteration of biofilm community composition in the impacted reservoirs. However, the biofilm composition was also influenced by water quality variables such as NO 3 - , SO 4 2- , DOC and Zn from unknown sources. The results of the present study imply that, even when below the environmental quality standards, typical contaminants of chlor-alkali plant releases may affect biofilm composition and that their impacts on the microbial biodiversity might be currently overlooked.

  17. Fused salt electrolysis

    Ares, Osvaldo; Botbol, Jose.

    1989-01-01

    Working conditions for zirconium preparation by fused salt electrolysis were studied. For such purpose, a cell was built for operation under argon atmosphere. A graphite crucible served as anode, with steel cathodes. Proper design allowed cathode rechange under the inert atmosphere. Cathodic deposits of zirconium powder occluded salts from the bath. After washing with both water and hydrochloric acid, the metallic powder was consolidated by fusion. Optimum operating conditions were found to arise from an electrolyte of 12% potassium hexafluorzirconate -88% sodium chloride, at 820 deg C and 5 A/cm 2 cathodic current density. Deposits contained 35% of metal and current efficiency reached 66%. The powder contained up to 600 ppm of chlorine and 1.700 ppm of fluorine; after fusion, those amounts decreased to 2 ppm and 3 ppm respectively, with low proportion of metallic impurities. Though oxygen proportion was 4.500 ppm, it should be lowered by improving working conditions, as well as working on an ampler scale. (Author)

  18. Heavy Metal Ion Removal and Wastewater Treatment by Combined Magnetic Particle and 3-D Electrochemical Technology

    Beltran, Michael

    1996-01-01

    .... Theoretical and experimental investigations performed in Phase I showed the feasibility of purification of wastewaters from Cr, Ni, and Cd by means of 3-D electrolysis with a cathode of carbon felt...

  19. Treating refinery wastewaters in microbial fuel cells using separator electrode assembly or spaced electrode configurations

    Zhang, Fang; Ahn, Yongtae; Logan, Bruce E.

    2014-01-01

    The effectiveness of refinery wastewater (RW) treatment using air-cathode, microbial fuel cells (MFCs) was examined relative to previous tests based on completely anaerobic microbial electrolysis cells (MECs). MFCs were configured with separator

  20. PEM Water Electrolysis at Elevated Temperatures

    Hansen, Martin Kalmar

    . This is followed in chapter 4 by a description of the electrolysis setups and electrolysis cells used during the work. Two different setups were used, one operating at atmospheric pressure and another that could operate at elevated pressure so that liquid water electrolysis could be performed at temperature above...... such as porosity and resistance which were supported by images acquired using scanning electron microscopy (SEM). In chapters 6 and 7 the results of the steam electrolysis and pressurised water electrolysis, respectively, are presented and discussed. The steam electrolysis was tested at 130 °C and atmospheric...... needed and hence it has become acute to be able to store the energy. Hydrogen has been identified as a suitable energy carrier and water electrolysis is one way to produce it in a sustainable and environmentally friendly way. In this thesis an introduction to the subject (chapter 1) is given followed...

  1. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    Logan, Bruce E.

    2008-12-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few years ago, rapid developments have led to hydrogen yields approaching 100%, energy yields based on electrical energy input many times greater than that possible by water electrolysis, and increased gas production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here the materials, architectures, performance, and energy efficiencies of these MEC systems that show promise as a method for renewable and sustainable energy production, and wastewater treatment. © 2008 American Chemical Society.

  2. Cadmium (II) removal mechanisms in microbial electrolysis cells

    Colantonio, Natalie; Kim, Younggy, E-mail: younggy@mcmaster.ca

    2016-07-05

    Highlights: • Rapid removal of Cd(II) was achieved in 24 h using microbial electrolysis cells. • Cathodic reduction (electrodeposition) of Cd(II) cannot explain the rapid removal. • H{sub 2} evolution in microbial electrolysis cells increases local pH near the cathode. • High local pH induces Cd(OH){sub 2} and CdCO{sub 3} precipitation only with electric current. • Neutral pH caused by low current and depleted substrate dissolves the precipitated Cd. - Abstract: Cadmium is a toxic heavy metal, causing serious environmental and human health problems. Conventional methods for removing cadmium from wastewater are expensive and inefficient for low concentrations. Microbial electrolysis cells (MECs) can simultaneously treat wastewater, produce hydrogen gas, and remove heavy metals with low energy requirements. Lab-scale MECs were operated to remove cadmium under various electric conditions: applied voltages of 0.4, 0.6, 0.8, and 1.0 V; and a fixed cathode potential of −1.0 V vs. Ag/AgCl. Regardless of the electric condition, rapid removal of cadmium was demonstrated (50–67% in 24 h); however, cadmium concentration in solution increased after the electric current dropped with depleted organic substrate under applied voltage conditions. For the fixed cathode potential, the electric current was maintained even after substrate depletion and thus cadmium concentration did not increase. These results can be explained by three different removal mechanisms: cathodic reduction; Cd(OH){sub 2} precipitation; and CdCO{sub 3} precipitation. When the current decreased with depleted substrates, local pH at the cathode was no longer high due to slowed hydrogen evolution reaction (2H{sup +} + 2e{sup −} → H{sub 2}); thus, the precipitated Cd(OH){sub 2} and CdCO{sub 3} started dissolving. To prevent their dissolution, sufficient organic substrates should be provided when MECs are used for cadmium removal.

  3. Investigation of the synergistic effects for p-nitrophenol mineralization by a combined process of ozonation and electrolysis using a boron-doped diamond anode

    Qiu, Cuicui [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Yuan, Shi [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Li, Xiang; Wang, Huijiao; Bakheet, Belal [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Komarneni, Sridhar [Department of Ecosystem Science and Management and Material Research Institute, 205 MRL Building, The Pennsylvania State University, University Park, PA 16802 (United States); Wang, Yujue, E-mail: wangyujue@tsinghua.edu.cn [School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084 (China); Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China)

    2014-09-15

    Graphical abstract: - Highlights: • Combining electrolysis with ozonation greatly enhances nitrophenol mineralization. • O{sub 3} can rapidly degrade nitrophenol to carboxylic acids in the bulk solution. • Carboxylic acids can be mineralized by ·OH generated from multiple sources in the electrolysis-O{sub 3} process. • Electrolysis and ozonation can compensate for each other's weakness on pollutant degradation. - Abstract: Electrolysis and ozonation are two commonly used technologies for treating wastewaters contaminated with nitrophenol pollutants. However, they are often handicapped by their slow kinetics and low yields of total organic carbon (TOC) mineralization. To improve TOC mineralization efficiency, we combined electrolysis using a boron-doped diamond (BDD) anode with ozonation (electrolysis-O{sub 3}) to treat a p-nitrophenol (PNP) aqueous solution. Up to 91% TOC was removed after 60 min of the electrolysis-O{sub 3} process. In comparison, only 20 and 44% TOC was respectively removed by individual electrolysis and ozonation treatment conducted under similar reaction conditions. The result indicates that when electrolysis and ozonation are applied simultaneously, they have a significant synergy for PNP mineralization. This synergy can be mainly attributed to (i) the rapid degradation of PNP to carboxylic acids (e.g., oxalic acid and acetic acid) by O{sub 3}, which would otherwise take a much longer time by electrolysis alone, and (ii) the effective mineralization of the ozone-refractory carboxylic acids to CO{sub 2} by ·OH generated from multiple sources in the electrolysis-O{sub 3} system. The result suggests that combining electrolysis with ozonation can provide a simple and effective way to mutually compensate the limitations of the two processes for degradation of phenolic pollutants.

  4. Electrical impedance tomography of electrolysis.

    Arie Meir

    Full Text Available The primary goal of this study is to explore the hypothesis that changes in pH during electrolysis can be detected with Electrical Impedance Tomography (EIT. The study has relevance to real time control of minimally invasive surgery with electrolytic ablation. To investigate the hypothesis, we compare EIT reconstructed images to optical images acquired using pH-sensitive dyes embedded in a physiological saline agar gel phantom treated with electrolysis. We further demonstrate the biological relevance of our work using a bacterial E.Coli model, grown on the phantom. The results demonstrate the ability of EIT to image pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E.coli model. The results are promising, and invite further experimental explorations.

  5. [Complex technology for water and wastewater disinfection and its industrial realization in prototype unit].

    Arakcheev, E N; Brunman, V E; Brunman, M V; Konyashin, A V; Dyachenko, V A; Petkova, A P

    Usage of complex automated electrolysis unit for drinking water disinfection and wastewater oxidation and coagulation is scoped, its ecological and energy efficiency is shown. Properties of technological process of anolyte production using membrane electrolysis of brine for water disinfection in municipal pipelines and potassium ferrate production using electrochemical dissolution of iron anode in NaOH solution for usage in purification plants are listed. Construction of modules of industrial prototype for anolyte and ferrate production and applied aspects of automation of complex electrolysis unit are proved. Results of approbation of electrolytic potassium ferrate for drinking water disinfection and wastewater, rain water and environmental water oxidation and coagulation are shown.

  6. Hydrogen production by alkaline water electrolysis

    Diogo M. F. Santos

    2013-01-01

    Full Text Available Water electrolysis is one of the simplest methods used for hydrogen production. It has the advantage of being able to produce hydrogen using only renewable energy. To expand the use of water electrolysis, it is mandatory to reduce energy consumption, cost, and maintenance of current electrolyzers, and, on the other hand, to increase their efficiency, durability, and safety. In this study, modern technologies for hydrogen production by water electrolysis have been investigated. In this article, the electrochemical fundamentals of alkaline water electrolysis are explained and the main process constraints (e.g., electrical, reaction, and transport are analyzed. The historical background of water electrolysis is described, different technologies are compared, and main research needs for the development of water electrolysis technologies are discussed.

  7. Hydrogen production by alkaline water electrolysis

    Santos, Diogo M. F.; Sequeira, César A. C.; Figueiredo, José L.

    2013-01-01

    Water electrolysis is one of the simplest methods used for hydrogen production. It has the advantage of being able to produce hydrogen using only renewable energy. To expand the use of water electrolysis, it is mandatory to reduce energy consumption, cost, and maintenance of current electrolyzers, and, on the other hand, to increase their efficiency, durability, and safety. In this study, modern technologies for hydrogen production by water electrolysis have been investigated. In this article...

  8. Reactive gaseous mercury is generated from chloralkali factories resulting in extreme concentrations of mercury in hair of workers

    Occupational exposure of chloralkali workers to highly concentrated mercury (Hg) vapour has been linked to an increased risk of renal dysfunction and behavioural changes. It is generally believed that these workers are exposed to elemental Hg, which is used in abundance during th...

  9. CHARACTERIZATION OF FUGITIVE MERCURY EMISSIONS FROM THE CELL BUILDING AT A U.S. CHLOR-ALKALI PLANT

    The paper discusses an extensive measurement campaign that was conducted of the fugitive (non-ducted) airborne elemental mercury [Hg(0)] emissions from the cell building of a chlor-alkali plant (CAP) located in the southeastern United States. The objectives of this study were to ...

  10. MEASUREMENT OF TOTAL SITE MERCURY EMISSIONS FROM A CHLOR-ALKALI PLANT USING OPEN-PATH UV-DOAS

    In December 2003, the EPA promulgated the National Emission Standard for Hazardous Air Pollutants for mercury cell chlor-alkali plants. In February 2004, the Natural Resources Defense Council filed petitions on the final rule in U.S. district court citing, among other issues, th...

  11. Mercury levels in lichens from different host trees around a chlor-alkali plant in New Brunswick, Canada.

    Sensen, Marion; Richardson, David H S

    2002-07-03

    Mercury concentrations were determined in the epiphytic lichen Hypogymnia physodes along five transects starting from a chlor-alkali plant located at Dalhousie, New Brunswick, a landfill site and a nearby electricity generating station. Lichen samples were collected from white birch (Betula papyrifera) and spruce (Picea sp.) or balsam fir (Abies balsamea). Average lichen background mercury values were 0.088+/-0.005 microg/g from white birch and 0.148+/-0.046 microg/g from spruce trees, with a detection limit of 0.05 microg/g. The chlor-alkali plant and a power plant were identified, respectively, as a major source and a minor source of elevated mercury levels in lichens. At 125 m north-west of the New Brunswick Power plant, 0.28 microg/g Hg were found in Hypogymnia physodes from spruce trees, while at 250 m west (downwind) of the chlor-alkali plant, 3.66 microg/g of mercury were determined. High values, 0.98 microg/g in lichens from spruce trees and 0.79 microg/g in lichen samples from white birch were also measured at 125 m south of the chlor-alkali plant and decreased exponentially with distance. The sphere of influence of the chlor-alkali plant with respect to mercury deposition was estimated to extend 2.4-3.4 km from the plant. The mercury concentrations in Hypogymnia physodes collected from white birch were significantly lower than the concentrations in the same lichen from spruce trees in areas with elevated levels of mercury, but not in areas with low mercury levels. The magnitude of this difference dropped with distance from the source.

  12. Comparison of complex effluent treatability in different bench scale microbial electrolysis cells

    Ullery, Mark L.

    2014-10-01

    A range of wastewaters and substrates were examined using mini microbial electrolysis cells (mini MECs) to see if they could be used to predict the performance of larger-scale cube MECs. COD removals and coulombic efficiencies corresponded well between the two reactor designs for individual samples, with 66-92% of COD removed for all samples. Current generation was consistent between the reactor types for acetate (AC) and fermentation effluent (FE) samples, but less consistent with industrial (IW) and domestic wastewaters (DW). Hydrogen was recovered from all samples in cube MECs, but gas composition and volume varied significantly between samples. Evidence for direct conversion of substrate to methane was observed with two of the industrial wastewater samples (IW-1 and IW-3). Overall, mini MECs provided organic treatment data that corresponded well with larger scale reactor results, and therefore it was concluded that they can be a useful platform for screening wastewater sources. © 2014 Elsevier Ltd.

  13. Energy conservation in the primary aluminum and chlor-alkali industries

    1980-10-01

    The primary aluminum and chlor-alkali industries together use nearly 13% of the electrical energy consumed by US industry. As part of its mission to promote energy conservation in basic US industries, the DOE surveys the present technological status of the major electrochemical industries and evaluates promising technological innovations that may lead to reduced energy requirements. This study provides technical and economic analyses in support of a government program of research and development in advanced electrolytic technology. This program is intended to supplement the development efforts directed toward energy savings by private industry. Sections II and III of this report cover aluminum and chlorine production processes only, since these two industries represent over 90% of the electrical energy requirements of all electrolytic industries in the United States. Section IV examines barriers to accelerated research and development by the electrolytic industries, and makes suggestions for government actions to overcome these barriers.

  14. Emissions, dispersion and human exposure of mercury from a Swedish chlor-alkali plant

    Wängberg, I.; Barregard, L.; Sällsten, G.; Haeger-Eugensson, M.; Munthe, J.; Sommar, J.

    Mercury in air near a mercury cell chlor-alkali plant in Sweden has been measured within the EU-project EMECAP. Based on the measurements and modelling the annual distributions of GEM and RGM have been calculated for the local area around the plant. The average concentration of GEM in residential areas near the plant was found to be 1-3.5 ng m -3 higher in comparison to the background concentration in this part of Sweden. The emission of RGM (0.55 kg year -1) results in elevated RGM concentrations close to the plant. The greatest impact on the local area is due to wet deposition of RGM. However, only a small fraction (0.4%) of all mercury being emitted was found to be deposited in the local area. No impact on urinary mercury could be demonstrated in the population living close to the plant.

  15. Mercury accumulation in transplanted Hypogymnia physodes lichens downwind of Wisconsin chlor-alkali plant

    Makholm, M.M.; Bennett, J.P.

    1998-01-01

    Emissions of mercury from a chlor-alkali plant in central Wisconsin have raised concern about possible effects on biota in the area. Samples of the lichen Hypogymnia physodes, which no longer grows in the area, were transplanted from a site in northeastern Wisconsin and positioned on plastic stands at varying distances up to 1250 m from the plant and sampled for Hg quarterly for one year to test the hypothesis that Hg would be taken up by the lichens and would decline with distance. Average tissue concentrations were elevated when first sampled at three months and continued to increase at the nearest sites until the study ended after one year. Average concentrations after a year of exposure ranged from 4418 ppb at 250 m from the plant to 403 ppb at 1250 m from the plant. The decrease over distance followed a negative exponential pattern. Background concentrations at a control site in northern Wisconsin averaged 155 ppb.

  16. Atmospheric mercury pollution around a chlor-alkali plant in Flix (NE Spain): an integrated analysis.

    Esbrí, José M; López-Berdonces, Miguel Angel; Fernández-Calderón, Sergio; Higueras, Pablo; Díez, Sergi

    2015-04-01

    An integrated analysis approach has been applied to a mercury (Hg) case study on a chlor-alkali plant located in the Ebro River basin, close to the town of Flix (NE Spain). The study focused on atmospheric Hg and its incorporation in soils and lichens close to a mercury cell chlor-alkali plant (CAP), which has been operating since the end of the 19th century. Atmospheric Hg present in the area was characterized by means of seven total gaseous mercury (TGM) surveys carried out from 2007 to 2012. Surveys were carried out by car, walking, and at fixed locations, and covered an area of some 12 km(2) (including the CAP area, the village in which workers live, Flix town, and the Sebes Wildlife Reserve). Finally, an atmospheric Hg dispersion model was developed with ISC-AERMOD software validated by a lichen survey of the area. The results for the atmospheric compartment seem to indicate that the Flix area currently has the highest levels of Hg pollution in Spain on the basis of the extremely high average concentrations in the vicinity of the CAP (229 ng m(-3)). Moreover, the Hg(0) plume affects Flix town center to some extent, with values well above the international thresholds for residential areas. Wet and dry Hg deposition reached its highest values on the banks of the Ebro River, and this contributes to increased soil contamination (range 44-12,900 ng g(-1), average 775 ng g(-1)). A good fit was obtained between anomalous areas indicated by lichens and the dispersion model for 1 year.

  17. Static feed water electrolysis module

    Powell, J. D.; Schubert, F. H.; Jensen, F. C.

    1974-01-01

    An advanced static feed water electrolysis module (SFWEM) and associated instrumentation for generating breathable O2 was developed. The system also generates a H2 byproduct for use in an air revitalization system for O2 recovery from metabolic CO2. Special attention was given to: (1) eliminating water feed compartment degassing, (2) eliminating need for zero gravity condenser/separators, (3) increasing current density capability, and (4) providing a self contained module so that operation is independent of laboratory instrumentation and complicated startup/shutdown procedures.

  18. Treatment of tanneries waste water by ultrasound assisted electrolysis process

    Farooq, R.; Ahmed, Z.; Gilani, M. A.; Durrani, M.; Mahmood, Q.; Shaukat, S. F.; Choima, N.

    2013-01-01

    The leather industry is a major producer of wastewater and solid waste containing potential water and soil contaminants. Considering the large amount and variety of chemical agents used in skin processing, the wastewaters generated by tanneries are very complex. Therefore, the development of treatment methods for these effluents is extremely necessary. In this work the electrochemical treatment of a tannery wastewater by ultrasound assisted electrochemical process, using stainless steel and lead cathode and titanium anodes was studied. Effect of ultrasound irradiation at various ultrasonic intensities 0, 40, 60 and 80% on electrochemical removal of chromium was investigated. Experiments were conducted at two pH conditions of pH 3 and 9. Significant removal of chromium was found at pH 3 and it was also noticed that by increasing ultrasonic intensities, percentage removal of chromium and sulfate also increases. The optimum removal of chromium and sulfate ions was observed at 80% ultrasonic intensity. The technique of electrolysis assisted with ultrasonic waves can be further improved and can be the future waste water treatment process for industries. (author)

  19. Wastewater Outfalls

    Iowa State University GIS Support and Research Facility — Outfalls which discharge wastewater from wastewater treatment facilities with individual NPDES permits. It does not include NPDES general permits.

  20. Voltammogram of stainless steel/Fe-Co-Ni electrode on water electrolysis in base condition with dahlia pinnata tuber starch media

    Isana S. Y., L.; Yuanita, Dewi; Sulistyani, Al, Heru Pratomo

    2017-08-01

    Hydrogen production in a safe, enviromentally friendly, and inexpensive is an attempt to realize energy needs commercially, one of them is electrolysis. Many attempts which relate with water electrolysis had been conducted to produce hydrogen, for example by using wastewater as water substitution. The research is to study the effect of dahlia pinnata tuber starch to stainless steel/Fe-Co-Ni electrode activity on water electrolysis in base condition. Stainless steel/Fe-Co-Ni electrode activity for breaking the water molecules eventually is better than stainless steel electrode, either there is existance of dahlia pinnata tuber starch or not. The presence of dahlia pinnata tuber starch apparently makes the covering on surface of the electrode so the catalytic activity of the electrode is reduced. Covering is mostly affected by dahlia pinnata tuber starch concentration. Wastewater which contains starch, especially dahlia pinnata tuber starch, obviously is not good enough because hydrogen production rate becomes obstructed.

  1. Hydrogen production through biocatalyzed electrolysis

    Rozendal, R.A.

    2007-01-01

    cum laude graduation (with distinction) To replace fossil fuels, society is currently considering alternative clean fuels for transportation. Hydrogen could be such a fuel. In theory, large amounts of renewable hydrogen can be produced from organic contaminants in wastewater. During his PhD research

  2. Water Electrolysis at Different Current - Voltage Regimes

    Kleperis, J.; Blums, J.; Vanags, M.

    2007-01-01

    Full text: Electrochemical impedance and volt-amperic methods were used to compare an efficiency of water electrolysis for different materials and different electrode configurations. Two and three electrode measurements were made, using standard calomel reference electrode. Non-standard capacitative electrolysis was analyzed in special cell made from cylindrical steel electrodes. Volt-amperic measurements from - 15V to +15V DC didn't indicated the presence of oxidation - reduction reactions when distilled water was used as electrolyte. Impedance measurements showed unusual frequency behavior when the AC voltage increased till 0.5V. Different nickel and carbon electrodes (plate, porous and textile - type) were used to learn classical Faraday electrolysis in strong alkali solutions. Flying increase of current was indicator of the presence of electrolysis, and characteristic potential was used differ between materials accordingly they effectiveness for usage in an electrolyser device. (Aithors)

  3. Water electrolysis system refurbishment and testing

    Greenough, B. M.

    1972-01-01

    The electrolytic oxygen generator for the back-up water electrolysis system in a 90-day manned test was refurbished, improved and subjected to a 182-day bench test. The performance of the system during the test demonstrated the soundness of the basic electrolysis concept, the high development status of the automatic controls which allowed completely hands-off operation, and the capability for orbital operation. Some design improvements are indicated.

  4. Electromagnetic radiation during electrolysis of heavy water

    Koval'chuk, E.P.; Yanchuk, O.M.; Reshetnyak, O.V.

    1994-01-01

    The radiation in the visible and ultraviolet spectral regions during electrolysis of heavy water on nickel and palladium cathodes was determined for the first time. A sharp jump of the intensity photon flow was observed at a current density of higher than 125 mA/cm 2 . A hypothesis about the relation of the electrochemiluminescence phenomenon during electrolysis of heavy water with the formation of fresh surfaces in consequence of the hydrogenous corrosion of the cathode material is formulated. ((orig.))

  5. Titanium metal obtention by fused salts electrolysis

    Perillo, P.M.; Ares, Osvaldo; Botbol, Jose.

    1989-01-01

    Potassium fluorotitanate dissolved in fused sodium chloride or potassium chloride may be electrolyzed under an inert gas atmosphere. Solid electrolysis products are formed on the cathode which contains titanium metal, sodium chloride, lower fluorotitanates and small quantities of alkali metal fluorotitanate. The extraction of titanium from the electrolysis products may be carried out by aqueous leaching (removal of chloride salts of alkali metals and a certain amount of fluorotitanates). Titanium metal obtained is relatively pure. (Author)

  6. Tritium separation from heavy water using electrolysis

    Ogata, Y.; Sakuma, Y.; Ohtani, N.; Kodaka, M.

    2001-01-01

    A tritium separation from heavy water by the electrolysis using a solid polymer electrode (SPE) was specified on investigation. The heavy water (∼10 Bq g -1 ) and the light water (∼70 Bq g -1 ) were electrolysed using an electrolysis device (Tripure XZ001, Permelec Electrode Ltd.) with the SPE layer. The cathode was made of stainless steel (SUS314). The electrolysis was carried out at 20 A x 60 min, with the electrolysis temperature at 10, 20, or 30degC, and 15 A x 80 min at 5degC. The produced hydrogen and oxygen gases were recombined using a palladium catalyst (ND-101, N.E. Chemcat Ltd.) with nitrogen gas as a carrier. The activities of the water in the cell and of the recombined water were analyzed using a liquid scintillation counter. The electrolysis potential to keep the current 20 A was 2-3 V. The yields of the recombined water were more than 90%. The apparent separation factors (SF) for the heavy water and the light water were ∼2 and ∼12, respectively. The SF value was in agreement with the results in other work. The factors were changed with the cell temperature. The electrolysis using the SPE is applicable for the tritium separation, and is able to perform the small-scale apparatus at the room temperature. (author)

  7. Microbial fuel cells and microbial electrolysis cells for the production of bioelectricity and biomaterials.

    Zhou, Minghua; Yang, Jie; Wang, Hongyu; Jin, Tao; Xu, Dake; Gu, Tingyue

    2013-01-01

    Today's global energy crisis requires a multifaceted solution. Bioenergy is an important part of the solution. The microbial fuel cell (MFC) technology stands out as an attractive potential technology in bioenergy. MFCs can convert energy stored in organic matter directly into bioelectricity. MFCs can also be operated in the electrolysis mode as microbial electrolysis cells to produce bioproducts such as hydrogen and ethanol. Various wastewaters containing low-grade organic carbons that are otherwise unutilized can be used as feed streams for MFCs. Despite major advances in the past decade, further improvements in MFC power output and cost reduction are needed for MFCs to be practical. This paper analysed MFC operating principles using bioenergetics and bioelectrochemistry. Several major issues were explored to improve the MFC performance. An emphasis was placed on the use of catalytic materials for MFC electrodes. Recent advances in the production of various biomaterials using MFCs were also investigated.

  8. An investigation of the possibility of mercury phytoremediation from Bandar ImamChlor-alkali plants' wastewater using Phragmites australis

    Tayebi, L.; Hamidian, A.H.; Danehkar, A.; Poorbagher, H.

    2016-01-01

    The Petrochemical industry is the most important and most widely active industries in the country. Due to the variety and complexity of industrial products, it also produces a wild range of pollutants. Mercury waste disposal from Chlor-alkali units is one of the fundamental problems of this industry. Various studies have shown that Phytoremediation system for removal of mercury from aqueous solutions is very efficient and, in some cases up to 95% of mercury has been removed from the solution. The purpose of this study was to evaluate the ability of common reed (Phragmites australis) in the removal of mercury from the Chlor-alkali effluent in Bandar Imam Petrochemical. Plant samples Harvested from Shadegan wetland were cultured hydroponically in plastic aquariums. Effluent samples which were taken from Chlor-alkali plants were added to the culture medium. An aquarium containing wastewater, water and nutrients was considered as control. Mercury concentrations in water and plant at 1, 3, 5 and 7 days were measured by Varian Spectra 220 Atomic Absorption Spectroscopy. The results showed that Time has a direct effect on mercury up taking by common reed. The common Reed absorption average was 2657.25 ppm within 7 days, that shows a high capacity of mercury absorption from Chlor-alkali plant effluents. Also In the study period, 96.25% of mercury were removed from common reed aquarium effulgent water.

  9. Fabrication of cathode supported tubular solid oxide electrolysis cell for high temperature steam electrolysis

    Shao, Le; Wang, Shaorong; Qian, Jiqin; Xue, Yanjie; Liu, Renzhu

    2011-01-15

    In recent years, hydrogen has been identified as a potential alternative fuel and energy carrier for the future energy supply. Water electrolysis is one of the important hydrogen production technologies which do not emit carbon dioxide. High temperature steam electrolysis (HTSE) consumes even less electrical energy than low temperature water electrolysis. Theoretically, HTSE using solid oxide electrolysis cells (SOEC) can efficiently utilize renewable energy to produce hydrogen, and it is also possible to operate the SOEC in reverse mode as the solid oxide fuel cell (SOFC) to produce electricity. Tubular SOFC have been widely investigated. In this study, tubular solid oxide cells were fabricated by dip-coating and cosintering techniques. In SOEC mode, results suggested that steam ratio had a strong impact on the performance of the tubular cell; the tubular SOEC preferred to be operated at high steam ratio in order to avoid concentration polarization. The microstructure of the tubular SOEC should therefore be optimized for high temperature steam electrolysis.

  10. Phytochelatin synthesis in response to Hg uptake in aquatic plants near a chlor-alkali factory.

    Turull, Marta; Grmanova, Gabriela; Dago, Àngela; Ariño, Cristina; Díez, Sergi; Díaz-Cruz, José Manuel; Esteban, Miquel

    2017-06-01

    The effects of mercury (Hg) released from a chlor-alkali factory in aquatic plants along the Ebro River basin (NE Spain) were analysed considering the phytochelatins (PC n ) and their isoforms content in these plants. These compounds were analyzed using HPLC with amperometric detection, and the macrophytes species Ceratophyllum demersum and Myriopyllum spicatum were collected in two sampling campaigns, autumn and spring, respectively. To correlate the PC n content in macrophytes with the Hg contamination, analysis of total Hg (THg) content in plants and suspended particulate matter, as well as the dissolved-bioavailable fraction of Hg in water measured by the diffusive gradient in thin film (DGT) technique were done. The results confirm the presence of PC 2 -Ala in extracts of C. demersum and PC 2 -desGly in M. spicatum, and the concentration of these thiol compounds depends clearly on the distance between the hot spot and the downstream sites: the higher the levels are, the closer the hot spot is. Since most of the Hg is hypothesized to be associated with SPM and transported downstream, our results of the DGT suggest that trace amounts of Hg in water can be released as free metal ions yielding a certain accumulation in plants (reaching the ppb level) that are enough for activation of induction of PCs. A few PCs species have been determined, at different seasons, indicating that they can be used as good indicators of the presence of bioavailable Hg in aquatic media throughout the year. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Phytoscreening as an efficient tool to delineate chlorinated solvent sources at a chlor-alkali facility.

    Yung, Loïc; Lagron, Jérôme; Cazaux, David; Limmer, Matt; Chalot, Michel

    2017-05-01

    Chlorinated ethenes (CE) are among the most common volatile organic compounds (VOC) that contaminate groundwater, currently representing a major source of pollution worldwide. Phytoscreening has been developed and employed through different applications at numerous sites, where it was generally useful for detection of subsurface chlorinated solvents. We aimed at delineating subsurface CE contamination at a chlor-alkali facility using tree core data that we compared with soil data. For this investigation a total of 170 trees from experimental zones was sampled and analyzed for perchloroethene (PCE) and trichloroethene (TCE) concentrations, measured by solid phase microextraction gas chromatography coupled to mass spectrometry. Within the panel of tree genera sampled, Quercus and Ulmus appeared to be efficient biomonitors of subjacent TCE and PCE contamination, in addition to the well known and widely used Populus and Salix genera. Among the 28 trees located above the dense non-aqueous phase liquid (DNAPL) phase zone, 19 tree cores contained detectable amounts of CE, with concentrations ranging from 3 to 3000 μg L -1 . Our tree core dataset was found to be well related to soil gas sampling results, although the tree coring data were more informative. Our data further emphasized the need for choosing the relevant tree species and sampling periods, as well as taking into consideration the nature of the soil and its heterogeneity. Overall, this low-invasive screening method appeared useful to delineate contaminants at a small-scale site impacted by multiple sources of chlorinated solvents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Durable solid oxide electrolysis cells and stacks

    Ming Chen

    2010-08-15

    The purpose of this project was to make a substantial contribution to development of a cost competitive electrolysis technology based on solid oxide cells. The strategy was to address what had been identified as the key issues in previous research projects. Accordingly five lines of work were carried out in the here reported project: 1) Cell and stack element testing and post test characterization to identify major degradation mechanisms under electrolysis operation. 2) Development of interconnects and coatings to allow stable electrolysis operation at approx850 deg. C or above. 3) Development of seals with reduced Si emission. 4) Development of durable SOEC cathodes. 5) Modeling. Good progress has been made on several of the planned activities. The outcome and most important achievements of the current project are listed for the five lines of the work. (LN)

  13. Wastewater Treatment

    ... day before releasing it back to the environment. Treatment plants reduce pollutants in wastewater to a level nature can handle. Wastewater is used water. It includes substances such as human waste, food ...

  14. Poisoning of Solid Oxide Electrolysis Cells by Impurities

    Ebbesen, Sune; Graves, Christopher R.; Hauch, Anne

    2010-01-01

    Electrolysis of H2O, CO2, and co-electrolysis of H2O and CO2 was studied in Ni/yttria-stabilized zirconia (YSZ) electrode supported solid oxide electrolysis cells (SOECs) consisting of a Ni/YSZ support, a Ni/YSZ electrode layer, a YSZ electrolyte, and an lanthanum strontium manganite (LSM)/YSZ ox...

  15. Transient nanobubbles in short-time electrolysis

    Svetovoy, Vitaly; Sanders, Remco G.P.; Elwenspoek, Michael Curt

    2013-01-01

    Water electrolysis in a microsystem is observed and analyzed on a short-time scale of ∼10 μs. The very unusual properties of the process are stressed. An extremely high current density is observed because the process is not limited by the diffusion of electroactive species. The high current is

  16. Towards solid oxide electrolysis plants in 2020

    Chen, Ming; Blennow, Peter; Mathiesen, Brian Vad

    The goal of the project is to further improve performance and durability of solid oxide electrolysis cells (SOECs) and stacks targeting applications specifically for regulating the future Danish power system with a high amount of fluctuating renewable energies, and at the same time enhance the co...

  17. Effect of time on dyeing wastewater treatment

    Ye, Tingjin; Chen, Xin; Xu, Zizhen; Chen, Xiaogang; Shi, Liang; He, Lingfeng; Zhang, Yongli

    2018-03-01

    The preparation of carboxymethylchitosan wrapping fly-ash adsorbent using high temperature activated fly ash and sodium carboxymethyl chitosan (CWF), as with the iron-carbon micro-electrolysis process simulation and actual printing and dyeing wastewater. The effects of mixing time and static time on decolorization ratio, COD removing rate and turbidness removing rate were investigated. The experimental results show that the wastewater stirring times on the decolorization rate and COD removal rate and turbidity removal rate influence, with increasing of the stirring time, three showed a downward trend, and reached the peak at 10 min time; wastewater time on the decolorization ratio and COD removing efficiency and turbidness removing rate influence, along with standing time increase, three who declined and reached the maximum in 30min time.

  18. Measurement of Total Site Mercury Emissions from a Chlor-Alkali Plant Using Ultraviolet Differential Optical Absorption Spectroscopy and Cell Room Roof-Vent Monitoring

    Mercury-cell chlor-alkali plants can emit significant quantities of fugitive elemental mercury vapor to the air as part of production operations and maintenance activities. In the fall of 2006, the U.S. Environmental Protection Agency (EPA) conducted a measurement project at a ch...

  19. Measurement of Total Site Mercury Emissions from Chlor-Alkali Plant Using Ultraviolet Differential Optical Absorption Spectroscopy and Cell Room Roof-Vent Monitoring

    This technical note describes a United States Environmental Protection Agency (U.S. EPA) measurement project to determine elemental mercury (Hg0) emissions from a mercury cell chlor-alkali (MCCA) facility in the southeastern U.S. during a 53-day monitoring campaign in the fall of...

  20. Hydrogen production profiles using furans in microbial electrolysis cells.

    Catal, Tunc; Gover, Tansu; Yaman, Bugra; Droguetti, Jessica; Yilancioglu, Kaan

    2017-06-01

    Microbial electrochemical cells including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are novel biotechnological tools that can convert organic substances in wastewater or biomass into electricity or hydrogen. Electroactive microbial biofilms used in this technology have ability to transfer electrons from organic compounds to anodes. Evaluation of biofilm formation on anode is crucial for enhancing our understanding of hydrogen generation in terms of substrate utilization by microorganisms. In this study, furfural and hydroxymethylfurfural (HMF) were analyzed for hydrogen generation using single chamber membrane-free MECs (17 mL), and anode biofilms were also examined. MECs were inoculated with mixed bacterial culture enriched using chloroethane sulphonate. Hydrogen was succesfully produced in the presence of HMF, but not furfural. MECs generated similar current densities (5.9 and 6 mA/cm 2 furfural and HMF, respectively). Biofilm samples obtained on the 24th and 40th day of cultivation using aromatic compounds were evaluated by using epi-fluorescent microscope. Our results show a correlation between biofilm density and hydrogen generation in single chamber MECs.

  1. Economics of liquid hydrogen from water electrolysis

    Lin, F. N.; Moore, W. I.; Walker, S. W.

    1985-01-01

    An economical model for preliminary analysis of LH2 cost from water electrolysis is presented. The model is based on data from vendors and open literature, and is suitable for computer analysis of different scenarios for 'directional' purposes. Cost data associated with a production rate of 10,886 kg/day are presented. With minimum modification, the model can also be used to predict LH2 cost from any electrolyzer once the electrolyzer's cost data are available.

  2. Tunable microbubble generator using electrolysis and ultrasound

    Younes Achaoui; Khaled Metwally; Damien Fouan; Zoubida Hammadi; Roger Morin; Eric Debieu; Cédric Payan; Serge Mensah

    2017-01-01

    This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant tha...

  3. Electrolysis activities at FCH Test Center

    Ravn Nielsen, Eva; Nygaard, Frederik Berg

    FCH Test Center for fuel cell and hydrogen technologies was established in 2010 at Risø DTU in Denmark. Today, the test center is part of DTU Energy Conversion. The center gives industry access to advanced testing and demonstration of components and systems. A number of national projects and EU...... projects regarding water electrolysis involve FCH Test Center as a partner. This presentation gives an overview of the activities....

  4. Performance of supported catalysts for water electrolysis

    Gurrik, Stian

    2012-01-01

    The most active catalyst for oxygen evolution in PEM water electrolysis is ruthenium oxide. Its major drawback as a commercial catalyst is its poor stability. In a mixed oxide with iridium, ruthenium becomes more stable. However, it would be favorable to find a less expensive substitute to iridium. In this work, the dissolution potential and lifetime of mixed oxides containing ruthenium and tantalum are investigated. In order to effectively determine what effects tantalum and particle size ha...

  5. Hydrogen electrolysis using a NASICON solid protonic conductor

    Gulens, J.; Longhurst, T.H.; Kuriakose, A.K.; Canaday, J.D.

    1988-09-01

    A protonic conductor based on a bonded NASICON disc has been used for hydrogen electrolysis at 300 K. Currents up to 200 mA can be passed through the disc, and the electrolysis proceeds with 100% current efficiency. The resistance of the ceramic is affected by its extent of hydration. Degradation and failure of the ceramic occurs at the cathode as a result of electrolysis.

  6. Microbial electrolysis cells as innovative technology for hydrogen production

    Chorbadzhiyska, Elitsa; Hristov, Georgi; Mitov, Mario; Hubenova, Yolina

    2011-01-01

    Hydrogen production is becoming increasingly important in view of using hydrogen in fuel cells. However, most of the production of hydrogen so far comes from the combustion of fossil fuels and water electrolysis. Microbial Electrolysis Cell (MEC), also known as Bioelectrochemically Assisted Microbial Reactor, is an ecologically clean, renewable and innovative technology for hydrogen production. Microbial electrolysis cells produce hydrogen mainly from waste biomass assisted by various bacteria strains. The principle of MECs and their constructional elements are reviewed and discussed. Keywords: microbial Electrolysis Cells, hydrogen production, waste biomass purification

  7. Mediated water electrolysis in biphasic systems.

    Scanlon, Micheál D; Peljo, Pekka; Rivier, Lucie; Vrubel, Heron; Girault, Hubert H

    2017-08-30

    The concept of efficient electrolysis by linking photoelectrochemical biphasic H 2 evolution and water oxidation processes in the cathodic and anodic compartments of an H-cell, respectively, is introduced. Overpotentials at the cathode and anode are minimised by incorporating light-driven elements into both biphasic reactions. The concepts viability is demonstrated by electrochemical H 2 production from water splitting utilising a polarised water-organic interface in the cathodic compartment of a prototype H-cell. At the cathode the reduction of decamethylferrocenium cations ([Cp 2 *Fe (III) ] + ) to neutral decamethylferrocene (Cp 2 *Fe (II) ) in 1,2-dichloroethane (DCE) solvent takes place at the solid electrode/oil interface. This electron transfer process induces the ion transfer of a proton across the immiscible water/oil interface to maintain electroneutrality in the oil phase. The oil-solubilised proton immediately reacts with Cp 2 *Fe (II) to form the corresponding hydride species, [Cp 2 *Fe (IV) (H)] + . Subsequently, [Cp 2 *Fe (IV) (H)] + spontaneously undergoes a chemical reaction in the oil phase to evolve hydrogen gas (H 2 ) and regenerate [Cp 2 *Fe (III) ] + , whereupon this catalytic Electrochemical, Chemical, Chemical (ECC') cycle is repeated. During biphasic electrolysis, the stability and recyclability of the [Cp 2 *Fe (III) ] + /Cp 2 *Fe (II) redox couple were confirmed by chronoamperometric measurements and, furthermore, the steady-state concentration of [Cp 2 *Fe (III) ] + monitored in situ by UV/vis spectroscopy. Post-biphasic electrolysis, the presence of H 2 in the headspace of the cathodic compartment was established by sampling with gas chromatography. The rate of the biphasic hydrogen evolution reaction (HER) was enhanced by redox electrocatalysis in the presence of floating catalytic molybdenum carbide (Mo 2 C) microparticles at the immiscible water/oil interface. The use of a superhydrophobic organic electrolyte salt was critical to

  8. Characterization of the extent of Mercury Contamination in the Androscoggin River from a former Chlor-alkali Facility, Berlin, New Hampshire

    Chalmers, A.; Marvin-Dipasquale, M. C.; Rosiu, C.; Luce, D.; Coles, J.; Zimmerman, M.; Smith, T.

    2010-12-01

    From the late 1800s to the 1960s a chlor-alkali plant was used to produce chlorine gas for the papermaking industry in Berlin, New Hampshire. During operation of the chlor-alkali facility, elemental mercury (Hg) was released to the environment, contaminating soils and the underlying fractured rock. Investigations have revealed that elemental Hg continues to seep through bedrock fractures into the adjacent Androscoggin River. This study evaluates the extent and transformation of Hg contamination in the Androscoggin River by comparing a reference site 17 kilometers above the former chlor-alkali facility to 5 sites ranging from 1 to 16 km downstream from the facility. Total and methyl Hg (THg and MeHg, respectively), among other analytes, were characterized in surface water, pore water, sediment and biological tissue samples at each site. Bed sediment was also assessed for bio-available (tin-reducible) inorganic Hg (II) and microbial MeHg production potential rates. Acid extractable ferrous iron, crystalline and amorphous (poorly crystalline) ferric iron, total reduced sulfur, particle size, and organic content in bed sediment was analyzed to help explain spatial differences in MeHg production rates and bio-available Hg (II) among sites. The information provided by this study will help evaluate the extent of Hg contamination in the Androscoggin River, will improve our understanding of the controls on MeHg production in the Androscoggin River system, and will be used by the U.S. Environmental Protection Agency to support remediation of the chlor-alkali facility site.

  9. Post depositional memory record of mercury in sediment near effluent disposal site of a chlor-alkali plant in Thane Creek-Mumbai Harbour, India

    Ram, A.; Rokade, M.A.; Zingde, M.D.; Borole, D.V.

    in landfills, mine tailings, contaminated industrial sites, soils and sediments. Estuaries and coastal marine regions form an essential link in the global biogeochemical cycling of Hg between the terrestrial environment - the major repository for atmospheric... by close relationship with organic matter, and Fe and Al oxides or sorbed onto the mineral particles [8]. Hence, sediments adjacent to the outfalls of chlor-alkali plants frequently contain high levels of Hg [7,10-15]. Some natural processes (water, soil...

  10. Wastewater Districts

    Vermont Center for Geographic Information — The Wastewater districts layer is part of a larger dataset that contains administrative boundaries for Vermont's Agency of Natural Resources. The dataset includes...

  11. Solid oxide electrolysis cells - Performance and durability

    Hauch, A.

    2007-10-15

    In this work H2 electrode supported solid oxide cells (SOC) produced at Risoe National Laboratory, DTU, have been used for steam electrolysis. Electrolysis tests have been performed at temperatures from 650AeC to 950AeC, p(H2O)/p(H2) from 0.99/0.01 to 0.30/0.70 and current densities from -0.25 A/cm2 to -2 A/cm2. The solid oxide electrolysis cells (SOEC) have been characterised by iV curves and electrochemical impedance spectroscopy (EIS) at start and end of tests and by EIS under current load during electrolysis testing. The tested SOCs have shown the best initial electrolysis performance reported in literature to date. Area specific resistances of 0.26 Oecm2 at 850AeC and 0.17 Oecm2 at 950AeC were obtained from electrolysis iV curves. The general trend for the SOEC tests was: 1) a short-term passivation in first few hundred hours, 2) then an activation and 3) a subsequent and underlying long-term degradation. The transient phenomenon (passivation/activation) was shown to be a set-up dependent artefact caused by the albite glass sealing with a p(Si(OH)4) of 1.10-7 atm, leading to silica contamination of the triple-phase boundaries (TPBs) of the electrode. The long-term degradation for the SOECs was more pronounced than for fuel cell testing of similar cells. Long-term degradation of 2%/1000 h was obtained at 850AeC, p(H2O)/p(H2) = 0.5/0.5 and -0.5 A/cm2, whereas the degradation rate increased to 6%/1000h at 950AeC, p(H2O)/p(H2) = 0.9/0.1 and -1.0 A/cm2. Both the short-term passivation and the long-term degradation appear mainly to be related to processes in the H2 electrode. Scanning electron microscopy micrographs show that only limited changes occur in the Ni particle size distribution and these are not the main degradation mechanism for the SOECs. Micro and nano analysis using energy dispersive spectroscopy in combination with transmission electron microscopy (TEM) and scanning TEM reveals that glassy phase impurities have accumulated at the TPBs as a result of

  12. Wastewater reuse

    Milan R. Radosavljević; Vanja M. Šušteršič

    2013-01-01

    Water scarcity and water pollution are some of the crucial issues that must be addressed within local and global perspectives. One of the ways to reduce the impact of water scarcity  and to minimizine water pollution is to expand water and wastewater reuse. The local conditions including regulations, institutions, financial mechanisms, availability of local technology and stakeholder participation have a great influence on the decisions for wastewater reuse. The increasing awareness of food s...

  13. Microscale Electrolysis Using Coin-Type Lithium Batteries and Filter

    Kamata, Masahiro; Yajima, Seiko

    2013-01-01

    An educational experiment illustrates the electrolysis of water and copper chloride to middle school science students. The electrolysis cell is composed of filter paper soaked with Na[subscript 2]SO[subscript 4] or CuCl[subscript 2] aqueous solution sandwiched, along with a sheet of platinum foil, between two coin-type lithium batteries. When the…

  14. Use of sodium salt electrolysis in the process of continuous ...

    This paper presents test results concerning the selection of sodium salt for the technology of continuous modification of the EN AC-AlSi12 alloy, which is based on electrolysis of sodium salts, occurring directly in a crucible with liquid alloy. Sodium ions formed as a result of the sodium salt dissociation and the electrolysis are ...

  15. High Temperature and Pressure Alkaline Electrolysis

    Allebrod, Frank

    against conventional technologies for hydrogen production, such as natural gas reforming, the production and investment costs have to be reduced. A reduction of the investment costs may be achieved by increasing the operational pressure and temperature of the electrolyzer, as this will result in: 1.......3 A cm-2 combined with relatively small production costs may lead to both reduced investment and operating costs for hydrogen and oxygen production. One of the produced electrolysis cells was operated for 350 h. Based on the successful results a patent application covering this novel cell was filed...

  16. Tunable microbubble generator using electrolysis and ultrasound

    Achaoui, Younes; Metwally, Khaled; Fouan, Damien; Hammadi, Zoubida; Morin, Roger; Debieu, Eric; Payan, Cédric; Mensah, Serge

    2017-01-01

    This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant that may modify the composition of the host fluid. It impacts across a broad range of scientific domains from bioengineering, sensing to environment.

  17. Tunable microbubble generator using electrolysis and ultrasound

    Younes Achaoui

    2017-01-01

    Full Text Available This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant that may modify the composition of the host fluid. It impacts across a broad range of scientific domains from bioengineering, sensing to environment.

  18. Fusion reactors for hydrogen production via electrolysis

    Fillo, J.A.; Powell, J.R.; Steinberg, M.

    1979-01-01

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and supplement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Depending on design, electric generation efficiencies of approx. 40 to 60% and hydrogen production efficiencies by high temperature electrolysis of approx. 50 to 70% are projected for fusion reactors using high temperature blankets

  19. Degradation in Solid Oxide Cells During High Temperature Electrolysis

    Manohar Sohal

    2009-05-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells. One goal of that project is to address the technical and degradation issues associated with solid oxide electrolysis cells. This report covers a variety of these degradation issues, which were discussed during a workshop on “Degradation in Solid Oxide Electrolysis Cells and Strategies for its Mitigation,” held in Phoenix, AZ on October 27, 2008. Three major degradation issues related to solid oxide electrolysis cells discussed at the workshop are: • Delamination of O2-electrode and bond layer on steam/O2-electrode side • Contaminants (Ni, Cr, Si, etc.) on reaction sites (triple-phase boundary) • Loss of electrical/ionic conductivity of electrolyte. This list is not all inclusive, but the workshop summary can be useful in providing a direction for future research related to the degradation of solid oxide electrolysis cells.

  20. APPLICATION OF ELECTROCHEMICAL METHODS FOR DECREASING OF CHEMICAL OXYGEN DEMAND (COD AND TOTAL SUSPENDED SOLID (TSS OF TOFU INDUSTRIAL WASTEWATER

    Suyata

    2015-05-01

    Full Text Available Tofu industrial wastewater has high COD and TSS level, which it cause an environmental pollution. Therefore, it is necessary to decrease the value of COD and TSS of tofu industrial wastewater before discharge into the water body. Decreasing of COD and TSS values can be carried out using an electrochemical method. The purpose of this research was to determine the effect of potential, electrode distance, pH, and time to decrease of COD and TSS value of the tofu industrial wastewater. The experiment has been performed by electrolysis tofu industrial wastewater using PbO2 as anode and Pb as cathode. The result of the research showed that under the optimum conditions of 12 V voltage, 1 cm electrode distance, pH 1, and electrolysis time of 120 minutes, decreasing COD and TSS of 96.33% and 87.87% respectively

  1. Treatment of process water containing heavy metals with a two-stage electrolysis procedure in a membrane electrolysis cell

    Fischer, R.; Krebs, P. [Technische Universitaet Dresden, Institut fuer Siedlungs- und Industriewasserwirtschaft, Mommsenstrasse 13, 01062 Dresden (Germany); Seidel, H. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Bioremediation, Permoserstrasse 15, D-04318 Leipzig (Germany); Morgenstern, P. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Analytik, Permoserstrasse 15, D-04318 Leipzig (Germany); Foerster, H.J.; Thiele, W. [Eilenburger Elektrolyse- und Umwelttechnik GmbH, Ziegelstrasse 2, D-04838 Eilenburg (Germany)

    2005-04-01

    The capability of a two-stage electrochemical treatment for the regeneration of acidic heavy-metal containing process water was examined. The process water came from sediment bioleaching and was characterized by a wide spectrum of dissolved metals, a high sulfate content, and a pH of about 3. In the modular laboratory model cell used, the anode chamber and the cathode chamber were separated by a central chamber fitted with an ion exchanger membrane on either side. The experiments were carried out applying a platinum anode and a graphite cathode at a current density of 0.1 A/cm{sup 2}. The circulation flow of the process water in the batch process amounted to 35 L/h, the electrolysis duration was 5.5 h at maximum and the total electrolysis current was about 1 A. In the first stage, the acidic process water containing metals passed through the cathode chamber. In the second stage, the cathodically pretreated process water was electrolyzed anodically. In the cathode chamber the main load of dissolved Cu, Zn, Cr and Pb was eliminated. The sulfuric acid surplus of 3-4 g/L decreased to about 1 g/L, the pH rose from initially 3.0 to 4-5, but the desired pH of 9-10 was not achieved. Precipitation in the proximity to the cathode evidently takes place at a higher pH than farther away. The dominant process in the anode chamber was the precipitation of amorphous MnO{sub 2} owing to the oxidation of dissolved Mn(II). The further depletion of the remaining heavy metals in the cathodically pretreated process water by subsequent anodic treatment was nearly exhaustive, more than 99 % of Cd, Cr, Cu, Mn, Ni, Pb, and Zn were removed from the leachate. The high depletion of heavy metals might be due to both the sorption on MnO{sub 2} precipitates and/or basic ferrous sulfate formed anodically, and the migration of metal ions through the cation exchanger membrane via the middle chamber into the cathode chamber. In the anode chamber, the sulfuric acid content increased to 6-7 g/L and the

  2. Preparation, Characterization of Coal Ash Adsorbent and Orthogonal Experimental Rsearch on Treating Printing and Dyeing Wastewater

    Wang, Qingyu; He, Lingfeng; Shi, Liang; Chen, Xiaogang; Chen, Xin; Xu, Zizhen; Zhang, Yongli

    2018-03-01

    Using high temperature activated sodium flying ash and carboxymethyl chitosan as raw material to prepare carboxymethylchitosan wrapping fly-ash adsorbent (CWF), combined with iron-carbon micro-electrolysis treatment of simulated and actual printing and dyeing wastewater. The conditions for obtaining are from the literature: the best condition for CWF to treat simulated printing and dyeing wastewater pretreated with iron-carbon micro-electrolysis is that the mixing time is 10min, the resting time is 30 min, pH=6, and the adsorbent dosage is 0.75 g/L. The results showed that COD removal efficiency and decoloration rate were above 97 %, and turbidity removal rate was over 90 %. The optimum dyeing conditions were used to treat the dyeing wastewater. The decolorization rate was 97.30 %, the removal efficiency of COD was 92.44 %, and the turbidity removal rate was 90.37 %.

  3. HYFIRE: fusion-high temperature electrolysis system

    Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Dang, V.D.; Horn, F.; Isaacs, H.; Lazareth, O.; Makowitz, H.; Usher, J.

    1980-01-01

    The Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constitutents, H 2 and O 2 , electrical input is required. Power cycle efficiencies of approx. 40% require He cooling for steam superheat. Fourteen hundred degree steam coupled with 40% power cycle efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

  4. Heavy water production by alkaline water electrolysis

    Kamath, Sachin; Sandeep, K.C.; Bhanja, Kalyan; Mohan, Sadhana; Sugilal, G.

    2014-01-01

    Several heavy water isotope production processes are reported in literature. Water electrolysis in combination with catalytic exchange CECE process is considered as a futuristic process to increase the throughput and reduce the cryogenic distillation load but the application is limited due to the high cost of electricity. Any improvement in the efficiency of electrolyzers would make this process more attractive. The efficiency of alkaline water electrolysis is governed by various phenomena such as activation polarization, ohmic polarization and concentration polarization in the cell. A systematic study on the effect of these factors can lead to methods for improving the efficiency of the electrolyzer. A bipolar and compact type arrangement of the alkaline water electrolyzer leads to increased efficiency and reduced inventory in comparison to uni-polar tank type electrolyzers. The bipolar type arrangement is formed when a number of single cells are stacked together. Although a few experimental studies have been reported in the open literature, CFD simulation of a bipolar compact alkaline water electrolyzer with porous electrodes is not readily available.The principal aim of this study is to simulate the characteristics of a single cell compact electrolyzer unit. The simulation can be used to predict the Voltage-Current Density (V-I) characteristics, which is a measure of the efficiency of the process.The model equations were solved using COMSOL multi-physics software. The simulated V-I characteristic is compared with the experimental data

  5. Efficient uranous nitrate production using membrane electrolysis

    Zhongwei Yuan; Taihong Yan; Weifang Zheng; Hongying Shuang; Liang Xian; Xiaoyan Bian; Chen Zuo; Chuanbo Li; Zhi Cao

    2013-01-01

    Electrochemical reduction of uranyl nitrate is a green, simple way to make uranous ion. In order to improve the ratio of uranous ion to the total uranium and maintain high current efficiency, an electrolyser with very thin cathodic and anodic compartment, which were separated by a cation exchange membrane, was setup, and its performance was tested. The effects of various parameters on the reduction were also evaluated. The results show that the apparatus is quite positive. It runs well with 120 mA/cm 2 current density (72 cm 2 cathode, constant current batch operation). U(IV) yield can achieve 93.1 % (500 mL feed, total uranium 199 g/L) after 180 min electrolysis. It was also shown that when U(IV) yield was below 80 %, very high current efficiency was maintained, and there was almost a linear relationship between uranous ion yield and electrolysis time; under the range of experimental conditions, the concentration of uranyl nitrate, hydrazine, and nitric acid had little effect on the reduction. (author)

  6. Carbon-encapsulated nickel-iron nanoparticles supported on nickel foam as a catalyst electrode for urea electrolysis

    Wu, Mao-Sung; Jao, Chi-Yu; Chuang, Farn-Yih; Chen, Fang-Yi

    2017-01-01

    Highlights: • Electrochemical process can purify the urea-rich wastewater, producing hydrogen gas. • Carbon-encapsulated nickel iron nanoparticles (CE-NiFe) are prepared by pyrolysis. • An ultra-thin layer of CE-NiFe nanoparticles is attached to the 3D Ni foam. • CE-NiFe nanoparticles escalate both the urea electrolysis and hydrogen evolution. - Abstract: A cyanide-bridged bimetallic coordination polymer, nickel hexacyanoferrate, could be pyrolyzed to form carbon-encapsulated nickel-iron (CE-NiFe) nanoparticles. The formation of nitrogen-doped spherical carbon shell with ordered mesoporous structure prevented the structural damage of catalyst cores and allowed the migration and diffusion of electrolyte into the hollow carbon spheres. An ultra-thin layer of CE-NiFe nanoparticles could be tightly attached to the three-dimensional macroporous nickel foam (NF) by electrophoretic deposition. The CE-NiFe nanoparticles could lower the onset potential and increase the current density in anodic urea electrolysis and cathodic hydrogen production as compared with bare NF. Macroporous NF substrate was very useful for the urea electrolysis and hydrogen production, which allowed for fast transport of electron, electrolyte, and gas products. The superior electrocatalytic ability of CE-NiFe/NF electrode in urea oxidation and water reduction made it favorable for versatile applications such as water treatment, hydrogen generation, and fuel cells.

  7. Progress in Aluminum Electrolysis Control and Future Direction for Smart Aluminum Electrolysis Plant

    Zhang, Hongliang; Li, Tianshuang; Li, Jie; Yang, Shuai; Zou, Zhong

    2017-02-01

    The industrial aluminum reduction cell is an electrochemistry reactor that operates under high temperatures and highly corrosive conditions. However, these conditions have restricted the measurement of key control parameters, making the control of aluminum reduction cells a difficult problem in the industry. Because aluminum electrolysis control systems have a significant economic influence, substantial research has been conducted on control algorithms, control systems and information systems for aluminum reduction cells. This article first summarizes the development of control systems and then focuses on the progress made since 2000, including alumina concentration control, temperature control and electrolyte molecular ratio control, fault diagnosis, cell condition prediction and control system expansion. Based on these studies, the concept of a smart aluminum electrolysis plant is proposed. The frame construction, key problems and current progress are introduced. Finally, several future directions are discussed.

  8. A Demonstration of Carbon-Assisted Water Electrolysis

    Olalekan D. Adeniyi

    2013-03-01

    Full Text Available It is shown that carbon fuel cell technology can be combined with that of high temperature steam electrolysis by the incorporation of carbon fuel at the cell anode, with the resulting reduction of the required electrolysis voltage by around 1 V. The behaviour of the cell current density and applied voltage are shown to be connected with the threshold of electrolysis and the main features are compared with theoretical results from the literature. The advantage arises from the avoidance of efficiency losses associated with electricity generation using thermal cycles, as well as the natural separation of the carbon dioxide product stream for subsequent processing.

  9. Hydrogen production by high-temperature electrolysis of water vapor steam. Test results obtained with an electrolysis tube

    Hino, Ryutaro; Miyamoto, Yoshiaki

    1995-01-01

    High-temperature electrolysis of water vapor steam is an advanced hydrogen production process decomposing high temperature steam up to 1,000degC, which applies an electro-chemical reaction reverse to the solid oxide fuel cell. At Japan Atomic Energy Research Institute, laboratory-scale experiments have been conducted using a practical electrolysis tube with 12 electrolysis cells in order to develop heat utilization systems for high-temperature gas-cooled reactors. The electrolysis cells of which electrolyte was yttria-stabilized zirconia were formed on a porous ceramic tube in series by plasma spraying. In the experiments, water steam mixed with argon carrier gas was supplied into the electrolysis tube heated at a constant temperature regulated in the range from 850degC to 950degC, and electrolysis power was supplied by a DC power source. Hydrogen production rate increased with applied voltage and electrolysis temperature; the maximum production rate was 6.9Nl/h at 950degC. Hydrogen production rate was correlated with applied current densities on the basis of experimental data. High energy efficiency was achieved under the applied current density ranging from 80 to 100 mA/cm 2 . (author)

  10. Wastewater reuse

    Milan R. Radosavljević

    2013-12-01

    Full Text Available Water scarcity and water pollution are some of the crucial issues that must be addressed within local and global perspectives. One of the ways to reduce the impact of water scarcity  and to minimizine water pollution is to expand water and wastewater reuse. The local conditions including regulations, institutions, financial mechanisms, availability of local technology and stakeholder participation have a great influence on the decisions for wastewater reuse. The increasing awareness of food safety and the influence of the countries which import food are influencing policy makers and agriculturists to improve the standards of wastewater reuse in agriculture. The environmental awareness of consumers has been putting pressure on the producers (industries to opt for environmentally sound technologies including those which conserve water and reduce the level of pollution. It may be observed that we have to move forwards to implement strategies and plans for wastewater reuse. However, their success and sustainability will depend on political will, public awareness and active support from national and international agencies to create favorable    environment for the promotion of environmentally sustainable technologies. Wastewater treatment has a long history, especially in agriculture, but also in industry and households. Poor quality of wastewater can pose a significant risk to the health of farmers and users of agricultural products. The World Health Organization (WHO is working on a project for the reuse of wastewater in agriculture. To reduce effects of human activities to the minimum, it is necessary to provide such technical and technological solutions that would on the one hand ensure complying with  the existing regulations and legislation, and on the other hand provide economically viable systems as seen through investments and operating costs. The use of wastewater The practice of using wastewater varies from country to country. Its

  11. Fundamental Insights into Propionate Oxidation in Microbial Electrolysis Cells Using a Combination of Electrochemical, Molecular biology and Electron Balance Approaches

    Rao, Hari Ananda

    2016-11-01

    Increasing demand for freshwater and energy is pushing towards the development of alternative technologies that are sustainable. One of the realistic solutions to address this is utilization of the renewable resources like wastewater. Conventional wastewater treatment processes can be highly energy demanding and can fails to recover the full potential of useful resources such as energy in the wastewater. As a consequence, there is an urgent necessity for sustainable wastewater treatment technologies that could harness such resources present in wastewaters. Advanced treatment process based on microbial electrochemical technologies (METs) such as microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) have a great potential for the resources recovery through a sustainable wastewater treatment process. METs rely on the abilities of microorganisms that are capable of transferring electrons extracellularly by oxidizing the organic matter in the wastewater and producing electrical current for electricity generation (MFC) or H2 and CH4 production (MEC). Propionate is an important volatile fatty acid (VFA) (24-70%) in some wastewaters and accumulation of this VFA can cause a process failure in a conventional anaerobic digestion (AD) system. To address this issue, MECs were explored as a novel, alternative wastewater treatment technology, with a focus on a better understanding of propionate oxidation in the anode of MECs. Having such knowledge could help in the development of more robust and efficient wastewater treatment systems to recover energy and produce high quality effluents. Several studies were conducted to: 1) determine the paths of electron flow in the anode of propionate fed MECs low (4.5 mM) and high (36 mM) propionate concentrations; 2) examine the effect of different set anode potentials on the electrochemical performance, propionate degradation, electron fluxes, and microbial community structure in MECs fed propionate; and 3) examine the temporal

  12. Static feed water electrolysis subsystem development

    Schubert, Franz H. (Inventor); Grigger, David J. (Inventor)

    1991-01-01

    This disclosure is directed to an electrolysis cell forming hydrogen and oxygen at spaced terminals. The anode terminal is porous and able to form oxygen within the cell and permit escape of the gaseous oxygen through the anode and out through a flow line in the presence of backpressure. Hydrogen is liberated in the cell at the opposing solid metal cathode which is permeable to hydrogen but not oxygen so that the migratory hydrogen formed in the cell is able to escape from the cell. The cell is maintained at an elevated pressure so that oxygen liberated by the cell is delivered at elevated pressure without pumping to raise the pressure of the oxygen.

  13. Operational Modelling of High Temperature Electrolysis (HTE)

    Patrick Lovera; Franck Blein; Julien Vulliet

    2006-01-01

    Solid Oxide Fuel Cells (SOFC) and High Temperature Electrolysis (HTE) work on two opposite processes. The basic equations (Nernst equation, corrected by a term of over-voltage) are thus very similar, only a few signs are different. An operational model, based on measurable quantities, was finalized for HTE process, and adapted to SOFCs. The model is analytical, which requires some complementary assumptions (proportionality of over-tensions to the current density, linearization of the logarithmic term in Nernst equation). It allows determining hydrogen production by HTE using a limited number of parameters. At a given temperature, only one macroscopic parameter, related to over-voltages, is needed for adjusting the model to the experimental results (SOFC), in a wide range of hydrogen flow-rates. For a given cell, this parameter follows an Arrhenius law with a satisfactory precision. The prevision in HTE process is compared to the available experimental results. (authors)

  14. Percutaneous treatment of pulmonary tumors by electrolysis

    Samuelsson, L.; Joensson, L.; Stahl, E.

    1983-06-01

    Five lung tumors in four patients were treated with electrolysis. One of the tumors was probably primary, while the others were metastases. Under local anesthesia, two or three platinum electrodes (diameter 3 mm) were introduced through the thoracic wall into the lung tumor using biplane fluoroscopy. The patient was sedated before the procedure and a chest tube was inserted into the pleural cavity. Between anode and cathode a direct current of 80 mA and 10 V was passed during 2-4 h, creating substantial electrolytic destruction mainly through chlorine liberation. Observations at autopsy, surgery, chest X-ray, and CT showed that 60%-80% of the tumor mass was destroyed. No tumor was completely destroyed. The patients stood the procedure well.

  15. Uranium metal production by molten salt electrolysis

    Takasawa, Yutaka

    1999-01-01

    Atomic vapor laser isotope separation (AVLIS) is a promising uranium enrichment technology in the next generation. Electrolytic reduction of uranium oxides into uranium metal is proposed for the preparation of uranium metal as a feed material for AVLIS plant. Considering economical performance, continuos process concept and minimizing the amount of radioactive waste, an electrolytic process for producing uranium metal directly from uranium oxides will offer potential advantages over the existing commercial process. Studies of uranium metal by electrolysis in fluoride salts (BaF 2 -LiF-UF 4 (74-11-15 w/o) at 1150-1200degC, using both a laboratory scale apparatus and an engineering scale one, and continuous casting of uranium metal were carried out in order to decide the optimum operating conditions and the design of the industrial electrolytic cells. (author)

  16. Advances in the electrolysis of tritiated water

    Pierini, G.; Spelta, B.; Maffei, S.; Modica, G.; Perez, G.; Possagno, E.

    1988-01-01

    The exhaust plasma processing plant, proposed a few years ago as an alternative to the Tritium Systems Test Assembly plant in operation at Los Alamos National Laboratory, required further research in such areas as low liquid inventory electrolytic cell and the types of separator or membrane resistant to beta radiation. Moreover, it was suggested that the value of the separation factors among H/sub 2/, D/sub 2/, and T/sub 2/ should be checked during electrolysis at high D/sub 2/O concentration in a alkaline medium by using different materials for the cathode. The results of experimental work carried out in these directions have shown the feasibility of the process, although some improvements can still be made in the optimization of the separators and in the design of the cell. The research carried out at the Joint Research Centre, Ispra, Italy, with support from other institutes, is described

  17. Economic Analysis of Improved Alkaline Water Electrolysis

    Kuckshinrichs, Wilhelm; Ketelaer, Thomas; Koj, Jan Christian

    2017-01-01

    Alkaline water electrolysis (AWE) is a mature hydrogen production technology and there exists a range of economic assessments for available technologies. For advanced AWEs, which may be based on novel polymer-based membrane concepts, it is of prime importance that development comes along with new configurations and technical and economic key process parameters for AWE that might be of interest for further economic assessments. This paper presents an advanced AWE technology referring to three different sites in Europe (Germany, Austria, and Spain). The focus is on financial metrics, the projection of key performance parameters of advanced AWEs, and further financial and tax parameters. For financial analysis from an investor’s (business) perspective, a comprehensive assessment of a technology not only comprises cost analysis but also further financial analysis quantifying attractiveness and supply/market flexibility. Therefore, based on cash flow (CF) analysis, a comprehensible set of metrics may comprise levelised cost of energy or, respectively, levelized cost of hydrogen (LCH) for cost assessment, net present value (NPV) for attractiveness analysis, and variable cost (VC) for analysis of market flexibility. The German AWE site turns out to perform best in all three financial metrics (LCH, NPV, and VC). Though there are slight differences in investment cost and operation and maintenance cost projections for the three sites, the major cost impact is due to the electricity cost. Although investment cost is slightly lower and labor cost is significantly lower in Spain, the difference can not outweigh the higher electricity cost compared to Germany. Given the assumption that the electrolysis operators are customers directly and actively participating in power markets, and based on the regulatory framework in the three countries, in this special case electricity cost in Germany is lowest. However, as electricity cost is profoundly influenced by political decisions as

  18. Basic study of alkaline water electrolysis

    Manabe, A.; Kashiwase, M.; Hashimoto, T.; Hayashida, T.; Kato, A.; Hirao, K.; Shimomura, I.; Nagashima, I.

    2013-01-01

    In order to realize future hydrogen society, hydrogen production systems must meet the large demand of hydrogen usage. Alkaline water electrolysis (AWE) would be one of the candidate technologies to produce hydrogen on a large scale from renewable energy. We have conducted basic research into AWE, trying to reveal technical issues under zero gap system in new cell technology. The zero gap system contributes lower cell voltage without causing any major operating problems compared with conventional finite gap cell. However, it was observed that Ni base electrodes showed corrosion phenomena in a number of test trials including steady operating conditions and several shut-downs. Activated Raney Ni alloy coating for anode material had an advantage for oxygen overvoltage. It showed a saving of around 100 mV at 40 A/dm 2 (0.4 A/cm 2 ) against Ni bare anodes. In the Chlor–Alkali (C/A) industry, thermal decomposition coating of mixed noble metal on Ni substrate is commonly used for advanced activated cathodes. It showed very low hydrogen over-potential of around 100 mV in AWE. To achieve better cell performance, separator selection is very important. We evaluated several separators including ion exchange membrane (IEM) to understand the basic function in AWE. IEM for C/A electrolysis showed high cell voltage (over 2.2 V) but low O 2 impurity in H 2 gas. Hydrogen purity was over 99.95%. Porous separators made of polypropylene showed 1.76 V at 40 A/dm 2 (0.4 A/cm 2 ), 80 °C. But there was a weakness on the durability for continuous operation. Proper selection of separator is important in an actual plant for effective and safe cell operation. The concept of safety operation is referred to by diffusion coefficient of hydrogen

  19. Economic Analysis of Improved Alkaline Water Electrolysis

    Kuckshinrichs, Wilhelm, E-mail: w.kuckshinrichs@fz-juelich.de; Ketelaer, Thomas; Koj, Jan Christian [Forschungszentrum Juelich, Institute for Energy and Climate Research – Systems Analysis and Technology Evaluation (IEK-STE), Juelich (Germany)

    2017-02-20

    Alkaline water electrolysis (AWE) is a mature hydrogen production technology and there exists a range of economic assessments for available technologies. For advanced AWEs, which may be based on novel polymer-based membrane concepts, it is of prime importance that development comes along with new configurations and technical and economic key process parameters for AWE that might be of interest for further economic assessments. This paper presents an advanced AWE technology referring to three different sites in Europe (Germany, Austria, and Spain). The focus is on financial metrics, the projection of key performance parameters of advanced AWEs, and further financial and tax parameters. For financial analysis from an investor’s (business) perspective, a comprehensive assessment of a technology not only comprises cost analysis but also further financial analysis quantifying attractiveness and supply/market flexibility. Therefore, based on cash flow (CF) analysis, a comprehensible set of metrics may comprise levelised cost of energy or, respectively, levelized cost of hydrogen (LCH) for cost assessment, net present value (NPV) for attractiveness analysis, and variable cost (VC) for analysis of market flexibility. The German AWE site turns out to perform best in all three financial metrics (LCH, NPV, and VC). Though there are slight differences in investment cost and operation and maintenance cost projections for the three sites, the major cost impact is due to the electricity cost. Although investment cost is slightly lower and labor cost is significantly lower in Spain, the difference can not outweigh the higher electricity cost compared to Germany. Given the assumption that the electrolysis operators are customers directly and actively participating in power markets, and based on the regulatory framework in the three countries, in this special case electricity cost in Germany is lowest. However, as electricity cost is profoundly influenced by political decisions as

  20. Removal of veterinary antibiotics from wastewater by electrocoagulation.

    Baran, Wojciech; Adamek, Ewa; Jajko, Marcin; Sobczak, Andrzej

    2018-03-01

    The aim of this study was to assess the effectiveness of veterinary antibiotic removal from wastewater using an electrocoagulation method. The removal efficiency of ampicillin, doxycycline, sulfathiazole and tylosin; the antibiotic degradation degree after electrolysis; and the toxicity and qualitative composition of antibiotic solutions after electrocoagulation were determined in the experiments. HPLC-QTOF was used for quantitative and qualitative determination. The eco-toxicity was assessed using the MARA ® assay. After electrocoagulation, the concentration of ampicillin, doxycycline, sulfathiazole and tylosin in wastewater decreased 3.6 ± 3.2%, ∼100%, 3.3 ± 0.4% and 3.1 ± 0.3%, respectively. Doxycycline was the only antibiotic effectively removed from wastewater during electrocoagulation. Simultaneously, part of this antibiotic underwent oxidative degradation. As a result of this process, the eco-toxicity in the reaction environment decreased. Copyright © 2017. Published by Elsevier Ltd.

  1. Technology advancement of the static feed water electrolysis process

    Schubert, F. H.; Wynveen, R. A.

    1977-01-01

    A program to advance the technology of oxygen- and hydrogen-generating subsystems based on water electrolysis was studied. Major emphasis was placed on static feed water electrolysis, a concept characterized by low power consumption and high intrinsic reliability. The static feed based oxygen generation subsystem consists basically of three subassemblies: (1) a combined water electrolysis and product gas dehumidifier module; (2) a product gas pressure controller and; (3) a cyclically filled water feed tank. Development activities were completed at the subsystem as well as at the component level. An extensive test program including single cell, subsystem and integrated system testing was completed with the required test support accessories designed, fabricated, and assembled. Mini-product assurance activities were included throughout all phases of program activities. An extensive number of supporting technology studies were conducted to advance the technology base of the static feed water electrolysis process and to resolve problems.

  2. Studies on membrane acid electrolysis for hydrogen production

    Silva, Marco Antonio Oliveira da; Linardi, Marcelo; Saliba-Silva, Adonis Marcelo [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Celulas a Combustivel e Hidrogenio], Email: saliba@ipen.br

    2010-07-01

    Hydrogen represents great opportunity to be a substitute for fossil fuels in the future. Water as a renewable source of hydrogen is of great interest, since it is abundant and can decompose, producing only pure H{sub 2} and O{sub 2}. This decomposition of water can be accomplished by processes such as electrolysis, thermal decomposition and thermochemical cycles. The electrolysis by membrane has been proposed as a viable process for hydrogen production using thermal and electrical energy derived from nuclear energy or any renewable source like solar energy. In this work, within the context of optimization of the electrolysis process, it is intended to develop a mathematical model that can simulate and assist in parameterization of the electrolysis performed by polymer membrane electrolytic cell. The experimental process to produce hydrogen via the cell membrane, aims to optimize the amount of gas produced using renewable energy with noncarbogenic causing no harm by producing gases deleterious to the environment. (author)

  3. Thermal dynamic analysis of sulfur removal from coal by electrolysis

    Li, D.; Gao, J.; Meng, F. [Qinghua University, Beijing (China). Dept. of Thermal Engineering

    2002-06-01

    The electrolytic reactions about sulfur removal from coal were studied by using chemical thermal dynamic analysis. According to the thermodynamical data, the Gibbs free energy value of the electrolytic reactions of pyritic and organic sulfur removal from coal is higher than zero. So, these electrolytic reactions are not spontaneous chemical reactions. In order to carry out desulfurisation by electrolysis, a certain voltage is necessary and important. Because theoretic decomposition voltage of pyrite and some parts of organic sulfur model compound is not very high, electrolysis reactions are easily to be carried out by using electrolysis technology. Mn ion and Fe ion are added into electrolysis solutions to accelerate the desulfurisation reaction. The electrolytic decomposition of coal is discussed. Because the theoretical decomposition voltage of some organic model compound is not high, the coal decomposition might happen. 17 refs., 4 tabs.

  4. Advanced Additive Manufacturing Feedstock from Molten Regolith Electrolysis

    National Aeronautics and Space Administration — Demonstrate the feasibility of Molten Regolith Electrolysis (MRE) Reactor start by initiating resistive-heating of the regolith past its melting point using...

  5. The micro-electrolysis technique in waste water treatment

    Jiti Zhou; Weihen Yang; Fenglin Yang; Xuemin Xiang; Yulu Wang

    1997-01-01

    The micro-electrolysis is one of the efficient methods to treat some kinds of waste water. The experiments have shown its high efficiency in sewage treatment and some kinds of industrial waste water. It is suitable for pre-treatment of high concentrated waste water and deep treatment of waste water for reuse purpose. The disadvantage of micro-electrolysis is its high energy consumption in case of high electrolyte concentration. (author) 2 figs., 11 tabs., 2 refs

  6. Hydrogen Production from Nuclear Energy via High Temperature Electrolysis

    James E. O'Brien; Carl M. Stoots; J. Stephen Herring; Grant L. Hawkes

    2006-01-01

    This paper presents the technical case for high-temperature nuclear hydrogen production. A general thermodynamic analysis of hydrogen production based on high-temperature thermal water splitting processes is presented. Specific details of hydrogen production based on high-temperature electrolysis are also provided, including results of recent experiments performed at the Idaho National Laboratory. Based on these results, high-temperature electrolysis appears to be a promising technology for efficient large-scale hydrogen production

  7. The micro-electrolysis technique in waste water treatment

    Jiti Zhou; Weihen Yang; Fenglin Yang; Xuemin Xiang; Yulu Wang [Dalian Univ. of Technology, Dalian (China)

    1997-12-31

    The micro-electrolysis is one of the efficient methods to treat some kinds of waste water. The experiments have shown its high efficiency in sewage treatment and some kinds of industrial waste water. It is suitable for pre-treatment of high concentrated waste water and deep treatment of waste water for reuse purpose. The disadvantage of micro-electrolysis is its high energy consumption in case of high electrolyte concentration. (author) 2 figs., 11 tabs., 2 refs.

  8. Chlor-alkali plant contamination of Aussa River sediments induced a large Hg-resistant bacterial community

    Baldi, Franco; Marchetto, Davide; Gallo, Michele; Fani, Renato; Maida, Isabel; Covelli, Stefano; Fajon, Vesna; Zizek, Suzana; Hines, Mark; Horvat, Milena

    2012-11-01

    A closed chlor-alkali plant (CAP) discharged Hg for decades into the Aussa River, which flows into Marano Lagoon, resulting in the large-scale pollution of the lagoon. In order to get information on the role of bacteria as mercury detoxifying agents, analyses of anions in the superficial part (0-1 cm) of sediments were conducted at four stations in the Aussa River. In addition, measurements of biopolymeric carbon (BPC) as a sum of the carbon equivalent of proteins (PRT), lipids (LIP), and carbohydrates (CHO) were performed to correlate with bacterial biomass such as the number of aerobic heterotrophic cultivable bacteria and their percentage of Hg-resistant bacteria. All these parameters were used to assess the bioavailable Hg fraction in sediments and the potential detoxification activity of bacteria. In addition, fifteen isolates were characterized by a combination of molecular techniques, which permitted their assignment into six different genera. Four out of fifteen were Gram negative with two strains of Stenotrophomonas maltophilia, one Enterobacter sp., and one strain of Brevibacterium frigoritolerans. The remaining strains (11) were Gram positive belonging to the genera Bacillus and Staphylococcus. We found merA genes in only a few isolates. Mercury volatilization from added HgCl2 and the presence of plasmids with the merA gene were also used to confirm Hg reductase activity. We found the highest number of aerobic heterotrophic Hg-resistant bacteria (one order magnitude higher) and the highest number of Hg-resistant species (11 species out of 15) at the confluence of the River Aussa and Banduzzi's channel, which transport Hg from the CAP, suggesting that Hg is strongly detoxified [reduced to Hg(0)] at this location.

  9. Biogeochemistry of mercury in a river-reservoir system: impact of an inactive chloralkali plant on the Holston River-Cherokee Reservoir, Virginia and Tennessee

    Hildebrand, S. G.; Lindberg, S. E.; Turner, R. R.; Huckabee, J. W.; Strand, R. H.; Lund, J. R.; Andren, A. W.

    1980-08-01

    Elevated mercury concentrations in fish species from the North Fork of the Holston River were observed in the early 1970's. The source of the mercury was a chloralkali plant which had ceased operation in 1972. Mercury continues to be released to the river from two large (approx. 40-ha) waste disposal ponds at the plant site. This report presents results of a study of the emission of mercury to the environment from the abandoned waste ponds and of the distribution of mercury in water, sediment, and biota of the Holston River-Cherokee Reservoir System in Virginia and eastern Tennessee.

  10. Complete degradation of Orange G by electrolysis in sub-critical water.

    Yuksel, Asli; Sasaki, Mitsuru; Goto, Motonobu

    2011-06-15

    Complete degradation of azo dye Orange G was studied using a 500 mL continuous flow reactor made of SUS 316 stainless steel. In this system, a titanium reactor wall acted as a cathode and a titanium plate-type electrode was used as an anode in a subcritical reaction medium. This hydrothermal electrolysis process provides an environmentally friendly route that does not use any organic solvents or catalysts to remove organic pollutants from wastewater. Reactions were carried out from 30 to 90 min residence times at a pressure of 7 MPa, and at different temperatures of 180-250°C by applying various direct currents ranging from 0.5 to 1A. Removal of dye from the product solution and conversion of TOC increased with increasing current value. Moreover, the effect of salt addition on degradation of Orange G and TOC conversion was investigated, because in real textile wastewater, many salts are also included together with dye. Addition of Na(2)CO(3) resulted in a massive degradation of the dye itself and complete mineralization of TOC, while NaCl and Na(2)SO(4) obstructed the removal of Orange G. Greater than 99% of Orange G was successfully removed from the product solution with a 98% TOC conversion. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Nickel-based electrodeposits as potential cathode catalysts for hydrogen production by microbial electrolysis

    Mitov, M.; Chorbadzhiyska, E.; Nalbandian, L.; Hubenova, Y.

    2017-07-01

    The development of cost-effective cathodes, operating at neutral pH and ambient temperatures, is a crucial challenge for the practical application of microbial electrolysis cell (MEC) technology. In this study, NiW and NiMo co-deposits produced by electroplating on Ni-foam are explored as cathodes in MEC. The fabricated electrodes exhibit higher corrosion stability and enhanced electrocatalytic activity towards hydrogen evolution reaction in neutral electrolyte compared to the bare Ni-foam. NiW/Ni-foam electrodes possess six times higher intrinsic catalytic activity, estimated from data obtained by linear voltammetry and chronoamperometry. The newly developed electrodes are applied as cathodes in single-chamber membrane-free MEC reactors, inoculated with wastewater and activated sludge from a municipal wastewater treatment plant. Cathodic hydrogen recovery of 79% and 89% by using NiW and NiMo cathodes, respectively, is achieved at applied voltage of 0.6 V. The obtained results reveal potential for practical application of used catalysts in MEC.

  12. Design of a water electrolysis flight experiment

    Lee, M. Gene; Grigger, David J.; Thompson, C. Dean; Cusick, Robert J.

    1993-01-01

    Supply of oxygen (O2) and hydrogen (H2) by electolyzing water in space will play an important role in meeting the National Aeronautics and Space Administration's (NASA's) needs and goals for future space missios. Both O2 and H2 are envisioned to be used in a variety of processes including crew life support, spacecraft propulsion, extravehicular activity, electrical power generation/storage as well as in scientific experiment and manufacturing processes. The Electrolysis Performance Improvement Concept Study (EPICS) flight experiment described herein is sponsored by NASA Headquarters as a part of the In-Space Technology Experiment Program (IN-STEP). The objective of the EPICS is to further contribute to the improvement of the SEF technology, specifially by demonstrating and validating the SFE electromechanical process in microgravity as well as investigating perrformance improvements projected possible in a microgravity environment. This paper defines the experiment objective and presents the results of the preliminary design of the EPICS. The experiment will include testing three subscale self-contained SFE units: one containing baseline components, and two units having variations in key component materials. Tests will be conducted at varying current and thermal condition.

  13. Modeling Degradation in Solid Oxide Electrolysis Cells

    Manohar S. Sohal; Anil V. Virkar; Sergey N. Rashkeev; Michael V. Glazoff

    2010-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic no equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, , within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, no equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  14. Reactions on carbon anodes in aluminium electrolysis

    Eidet, Trygve

    1997-12-31

    The consumption of carbon anodes and energy in aluminium electrolysis is higher than what is required theoretically. This thesis studies the most important of the reactions that consume anode materials. These reactions are the electrochemical anode reaction and the airburn and carboxy reactions. The first part of the thesis deals with the kinetics and mechanism of the electrochemical anode reaction using electrochemical impedance spectroscopy. The second part deals with air and carboxy reactivity of carbon anodes and studies the effects of inorganic impurities on the reactivity of carbon anodes in the aluminium industry. Special attention is given to sulphur since its effect on the carbon gasification is not well understood. Sulphur is always present in anodes, and it is expected that the sulphur content of available anode cokes will increase in the future. It has also been suggested that sulphur poisons catalyzing impurities in the anodes. Other impurities that were investigated are iron, nickel and vanadium, which are common impurities in anodes which have been reported to catalyze carbon gasification. 88 refs., 92 figs., 24 tabs.

  15. Wastewater treatment

    Ranđel N. Kitanović

    2013-10-01

    Full Text Available Quality of life on Earth in the future will largely depend on the amount of safe water. As the most fundamental source of life, water is relentlessly consumed and polluted. To halt this trend, many countries are taking extensive measures and investing substantial resources in order to stop the contamination of water and return at least tolerably good water quality to nature. The goal of water purification is to obtain clean water with the sewage sludge as a by-product. Clean water is returned to nature, and further treatment of sludge may be subject to other procedures. The conclusion of this paper is simple. The procedure with purified water is easily achievable, purified water is discharged into rivers, lakes and seas, but the problem of further treatment of sludge remains. This paper presents the basic methods of wastewater treatment and procedures for processing the products from contaminated water. The paper can serve as a basis for further elaboration. Water Pollution In order to ensure normal life of living creatures, the water in which they live or the water they use must have a natural chemical composition and natural features. When, as a result of human activities, the chemical composition of water and the ratio of its chemical elements significantly change, we say that water is polluted. When the pollutants come from industrial plants, we are talking about industrial wastewater, and when they come from households and urban areas, we are talking about municipal wastewater. Both contain a huge amount of pollutants that eventually end up in rivers. Then, thousands of defenseless birds, fish and other animals suffer, and environmental consequences become immeasurable. In addition, the waste fed to the water often ends up in the bodies of marine animals, so they can return to us as food. Thermal water pollution also has multiple effects on the changes in the wildlife composition of aquatic ecosystems. Polluted water can be purified by

  16. Persistent Hg contamination and occurrence of Hg-methylating transcript (hgcA) downstream of a chlor-alkali plant in the Olt River (Romania).

    Bravo, Andrea G; Loizeau, Jean-Luc; Dranguet, Perrine; Makri, Stamatina; Björn, Erik; Ungureanu, Viorel Gh; Slaveykova, Vera I; Cosio, Claudia

    2016-06-01

    Chlor-alkali plants using mercury (Hg) cell technology are acute point sources of Hg pollution in the aquatic environment. While there have been recent efforts to reduce the use of Hg cells, some of the emitted Hg can be transformed to neurotoxic methylmercury (MeHg). Here, we aimed (i) to study the dispersion of Hg in four reservoirs located downstream of a chlor-alkali plant along the Olt River (Romania) and (ii) to track the activity of bacterial functional genes involved in Hg methylation. Total Hg (THg) concentrations in water and sediments decreased successively from the initial reservoir to downstream reservoirs. Suspended fine size particles and seston appeared to be responsible for the transport of THg into downstream reservoirs, while macrophytes reflected the local bioavailability of Hg. The concentration and proportion of MeHg were correlated with THg, but were not correlated with bacterial activity in sediments, while the abundance of hgcA transcript correlated with organic matter and Cl(-) concentration, indicating the importance of Hg bioavailability in sediments for Hg methylation. Our data clearly highlights the importance of considering Hg contamination as a legacy pollutant since there is a high risk of continued Hg accumulation in food webs long after Hg-cell phase out.

  17. Monitoring and assessment of mercury pollution in the vicinity of a chloralkali plant. IV. Bioconcentration of mercury in in situ aquatic and terrestrial plants at Ganjam, India.

    Lenka, M; Panda, K K; Panda, B B

    1992-02-01

    In situ aquatic and terrestrial plants including a few vegetable and crop plants growing in and around a chloralkali plant at Ganjam, India were analyzed for concentrations of root and shoot mercury. The aquatic plants found to bioconcentrate mercury to different degrees included Marsilea spp., Spirodela polyrhiza, Jussiea repens, Paspalum scrobiculatam, Pistia stratiotes, Eichhornia crassipes, Hygrophila schulli, Monochoria hastata and Bacopa monniera. Among wild terrestrial plants Chloris barbata, Cynodon dactylon, Cyperus rotundus and Croton bonplandianum were found growing on heavily contaminated soil containing mercury as high as 557 mg/kg. Analysis of mercury in root and shoot of these plants in relation to the mercury levels in soil indicated a significant correlation between soil and plant mercury with the exception of C. bonplandianum. Furthermore, the tolerance to mercury toxicity was highest with C. barbata followed by C. dactylon and C. rotundus, in that order. The rice plants analyzed from the surrounding agricultural fields did not show any significant levels of bioconcentrated mercury. Of the different vegetables grown in a contaminated kitchen garden with mercury level at 8.91 mg/kg, the two leafy vegetables, namely cabbage (Brassica oleracea) and amaranthus (Amaranthus oleraceous), were found to bioconcentrate mercury at statistically significant levels. The overall study indicates that the mercury pollution is very much localized to the specific sites in the vicinity of the chloralkali plant.

  18. Chlor-alkali industrial contamination and riverine transport of mercury: Distribution and partitioning of mercury between water, suspended matter, and bottom sediment of the Thur River, France

    Hissler, Christophe; Probst, Jean-Luc

    2006-01-01

    Total dissolved and total particulate Hg mass balances were estimated during one hydrological period (July 2001-June 2002) in the Thur River basin, which is heavily polluted by chlor-alkali industrial activity. The seasonal variations of the Hg dynamics in the aquatic environment were assessed using total Hg concentrations in bottom sediment and suspended matter, and total and reactive dissolved Hg concentrations in the water. The impact of the chlor-alkali plant (CAP) remains the largest concern for Hg contamination of this river system. Upstream from the CAP, the Hg partitioning between dissolved and particulate phases was principally controlled by the dissolved fraction due to snow melting during spring high flow, while during low flow, Hg was primarily adsorbed onto particulates. Downstream from the CAP, the Hg partitioning is controlled by the concentration of dissolved organic and inorganic ligands and by the total suspended sediment (TSS) concentrations. Nevertheless, the particulate fluxes were five times higher than the dissolved ones. Most of the total annual flux of Hg supplied by the CAP to the river is transported to the outlet of the catchment (total Hg flux: 70 μg m -2 a -1 ). Downstream from the CAP, the bottom sediment, mainly composed of coarse sediment (>63 μm) and depleted in organic matter, has a weak capacity to trap Hg in the river channel and the stock of Hg is low (4 mg m -2 ) showing that the residence time of Hg in this river is short

  19. Steam electrolysis by solid oxide electrolysis cells (SOECs) with proton-conducting oxides.

    Bi, Lei; Boulfrad, Samir; Traversa, Enrico

    2014-12-21

    Energy crisis and environmental problems caused by the conventional combustion of fossil fuels boost the development of renewable and sustainable energies. H2 is regarded as a clean fuel for many applications and it also serves as an energy carrier for many renewable energy sources, such as solar and wind power. Among all the technologies for H2 production, steam electrolysis by solid oxide electrolysis cells (SOECs) has attracted much attention due to its high efficiency and low environmental impact, provided that the needed electrical power is generated from renewable sources. However, the deployment of SOECs based on conventional oxygen-ion conductors is limited by several issues, such as high operating temperature, hydrogen purification from water, and electrode stability. To avoid these problems, proton-conducting oxides are proposed as electrolyte materials for SOECs. This review paper provides a broad overview of the research progresses made for proton-conducting SOECs, summarizing the past work and finding the problems for the development of proton-conducting SOECs, as well as pointing out potential development directions.

  20. Steam electrolysis by solid oxide electrolysis cells (SOECs) with proton-conducting oxides

    Bi, Lei; Boulfrad, Samir; Traversa, Enrico

    2014-01-01

    Energy crisis and environmental problems caused by the conventional combustion of fossil fuels boost the development of renewable and sustainable energies. H2 is regarded as a clean fuel for many applications and it also serves as an energy carrier for many renewable energy sources, such as solar and wind power. Among all the technologies for H2 production, steam electrolysis by solid oxide electrolysis cells (SOECs) has attracted much attention due to its high efficiency and low environmental impact, provided that the needed electrical power is generated from renewable sources. However, the deployment of SOECs based on conventional oxygen-ion conductors is limited by several issues, such as high operating temperature, hydrogen purification from water, and electrode stability. To avoid these problems, proton-conducting oxides are proposed as electrolyte materials for SOECs. This review paper provides a broad overview of the research progresses made for proton-conducting SOECs, summarizing the past work and finding the problems for the development of proton-conducting SOECs, as well as pointing out potential development directions.

  1. Influence of a chlor-alkali superfund site on mercury bioaccumulation in periphyton and low-trophic level fauna

    Buckman, Kate L.; Marvin-DiPasquale, Mark C.; Taylor, Vivien F.; Chalmers, Ann T.; Broadley, Hannah J.; Agee, Jennifer L.; Jackson, Brian P.; Chen, Celia Y.

    2015-01-01

    In Berlin, New Hampshire, USA, the Androscoggin River flows adjacent to a former chlor-alkali facility that is a US Environmental Protection Agency Superfund site and source of mercury (Hg) to the river. The present study was conducted to determine the fate and bioaccumulation of methylmercury (MeHg) to lower trophic-level taxa in the river. Surface sediment directly adjacent to the source showed significantly elevated MeHg (10–40× increase, mean ± standard deviation [SD]: 20.1 ± 24.8 ng g–1 dry wt) and total mercury (THg; 10–30× increase, mean ± SD: 2045 ± 2669 ng g–1 dry wt) compared with all other reaches, with sediment THg and MeHg from downstream reaches elevated (3–7× on average) relative to the reference (THg mean ± SD: 33.5 ± 9.33 ng g–1 dry wt; MeHg mean ± SD: 0.52 ± 0.21 ng g–1 dry wt). Water column THg concentrations adjacent to the point source for both particulate (0.23 ng L–1) and dissolved (0.76 ng L–1) fractions were 5-fold higher than at the reference sites, and 2-fold to 5-fold higher than downstream. Methylmercury production potential of periphyton material was highest (2–9 ng g–1 d–1 dry wt) adjacent to the Superfund site; other reaches were close to or below reporting limits (0. 1 ng g–1 d–1 dry wt). Total Hg and MeHg bioaccumulation in fauna was variable across sites and taxa, with no clear spatial patterns downstream of the contamination source. Crayfish, mayflies, and shiners showed a weak positive relationship with porewater MeHg concentration.

  2. High Temperature Electrolysis using Electrode-Supported Cells

    O'Brien, J.E.; Stoots, C.M.

    2010-01-01

    An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production. The cells currently under study were developed primarily for the fuel cell mode of operation. Results presented in this paper were obtained from single cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes (∼10 (micro)m thick), nickel-YSZ steam/hydrogen electrodes (∼1400 (micro)m thick), and manganite (LSM) air-side electrodes (∼90 (micro)m thick). The purpose of the present study was to document and compare the performance and degradation rates of these cells in the fuel cell mode and in the electrolysis mode under various operating conditions. Initial performance was documented through a series of DC potential sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-duration testing, first in the fuel cell mode, then in the electrolysis mode over more than 500 hours of operation. Results indicate accelerated degradation rates in the electrolysis mode compared to the fuel cell mode, possibly due to electrode delamination. The paper also includes details of the single-cell test apparatus developed specifically for these experiments.

  3. Condutivity effect in electro-coagulation-flotation applied to physico-chemical wastewater treatment

    Francisco Javier Cuba Terán; Mário Luiz Rodrigues Foco

    2007-01-01

    This study reports on the effect of conductivity on the simultaneous applicability of water electrolysis , chemical coagulation and flotation fundamentals in the treatment of wastewater with large amounts of suspended matter, characterizing electro-coagulation-flotation (ECF) . Results from experiments carried out in a pilot study implanted and operated in the Laboratory of Environment Control (LCA), at the State University of Campinas in Limeira are presented. ECF was developed in an electro...

  4. Studies on Removal of Dyes from wastewater using Electro-coagulation Process

    N B. Patel; B D. Soni; J P. Ruparelia

    2000-01-01

    Electro-coagulation (EC) is one of the effective techniques to remove colour, COD and organic compounds from wastewater. In this paper electro coagulation technique has been used for the removal of colour and COD from dye solutions containing Direct Black 22 and Acid Red 97 using batch process. For batch the process effect of operational parameters such as current density, initial pH of the solution, time of electrolysis and electrode materials were studied to attempt max...

  5. A Small-Scale and Low-Cost Apparatus for the Electrolysis of Water

    Eggeen, Per-Odd; Kvittingen, Lise

    2004-01-01

    The construction of two simple, inexpensive apparatuses that clearly show the electrolysis of water are described. Traditionally the electrolysis of water is conducted in a Hofmann apparatus which is expensive and fragile.

  6. Development status of a preprototype water electrolysis subsystem

    Martin, R. B.; Erickson, A. C.

    1981-01-01

    A preprototype water electrolysis subsystem was designed and fabricated for NASA's advanced regenerative life support program. A solid polymer is used for the cell electrolyte. The electrolysis module has 12 cells that can generate 5.5 kg/day of oxygen for the metabolic requirements of three crewmembers, for cabin leakage, and for the oxygen and hydrogen required for carbon dioxide collection and reduction processes. The subsystem can be operated at a pressure between 276 and 2760 kN/sq m and in a continuous constant-current, cyclic, or standby mode. A microprocessor is used to aid in operating the subsystem. Sensors and controls provide fault detection and automatic shutdown. The results of development, demonstration, and parametric testing are presented. Modifications to enhance operation in an integrated and manned test are described. Prospective improvements for the electrolysis subsystem are discussed.

  7. Solid oxide electrolysis cell for decomposition of tritiated water

    Konishi, S.; Ohno, H.; Yoshida, H.; Katsuta, H.; Naruse, Y.

    1986-01-01

    The decomposition of tritiated water vapor by means of solid oxide electrolysis cells has been proposed for the application to the D-T fusion reactor system. This method is essentially free from problems such as large tritium inventory, radiation damage, and generation of solid waste, so it is expected to be a promising one. Electrolysis of water vapor in an argon carrier was performed using a tube-type stabilized zirconia cell with porous platinum electrodes over the temperature range 500-950 0 C. High conversion ratios from water to hydrogen, of up to 99.9%, were achieved. The characteristics of the cell were deduced from the Nernst equation and the conversion ratios expressed as a function of the IR-free voltage. Experimental results agreed with the equation. The isotope effect in electrolysis is also discussed and experiments with heavy water were carried out. The obtained separation factor was slightly higher than the theoretical value. (author)

  8. Solid oxide electrolysis cell for decomposition of tritiated water

    Konishi, S.; Katsuta, H.; Naruse, Y.; Ohno, H.; Yoshida, H.

    1984-01-01

    The decomposition of tritiated water vapor with solid oxide electrolysis cell was proposed for the application to the D-T fusion reactor system. This method is essentially free from problems such as large tritium inventory, radiation damage, and generation of solid waste, so it is expected to be a promising one. Electrolysis of water vapor in argon carrier was performed using tube-type stabilized zirconia cell with porous platinum electrodes in the temperature range of 500 0 C to 950 0 C. High conversion ratio from water to hydrogen up to 99.9% was achieved. The characteristics of the cell is deduced from the Nernst's equation and conversion ratio is described as the function of the open circuit voltage. Experimental results agreed with the equation. Isotope effect in electrolysis is also discussed and experiments with heavy water were carried out. Obtained separation factor was slightly higher than the theoretical value

  9. Development of Hydrogen Electrodes for Alkaline Water Electrolysis

    Kjartansdóttir, Cecilía Kristín

    , production of electricity via fuel cells, fuel for internal combustion engines or gas turbines, or as a raw material for the production of synthetic fuels via Sabatier or Fischer - Tropsch process. In some situations it may be suitable to simply inject hydrogen into the existing natural gas based...... will be needed. Producing hydrogen via water electrolysis using surplus, low cost, power from renewables offers the possibility of increased production capacity and load management with no greenhouse emissions. Hydrogen is a valuable energy carrier, which is able to contribute to various forms of energy, such as...... infrastructure. Alkaline water electrolysis (AWE) is the current standard (stat of the art) for industrial large-scale water electrolysis systems. One of the main criteria for industrial AWE is efficient and durable electrodes. The aim of the present PhD study was to develop electrode materials for hydrogen...

  10. Phosphate Recovery from Human Waste via the Formation of Hydroxyapatite during Electrochemical Wastewater Treatment.

    Cid, Clément A; Jasper, Justin T; Hoffmann, Michael R

    2018-03-05

    Electrolysis of toilet wastewater with TiO 2 -coated semiconductor anodes and stainless steel cathodes is a potentially viable onsite sanitation solution in parts of the world without infrastructure for centralized wastewater treatment. In addition to treating toilet wastewater, pilot-scale and bench-scale experiments demonstrated that electrolysis can remove phosphate by cathodic precipitation as hydroxyapatite at no additional energy cost. Phosphate removal could be predicted based on initial phosphate and calcium concentrations, and up to 80% total phosphate removal was achieved. While calcium was critical for phosphate removal, magnesium and bicarbonate had only minor impacts on phosphate removal rates at concentrations typical of toilet wastewater. Optimal conditions for phosphate removal were 3 to 4 h treatment at about 5 mA cm -2 (∼3.4 V), with greater than 20 m 2 m -3 electrode surface area to reactor volume ratios. Pilot-scale systems are currently operated under similar conditions, suggesting that phosphate removal can be viewed as an ancillary benefit of electrochemical wastewater treatment, adding utility to the process without requiring additional energy inputs. Further value may be provided by designing reactors to recover precipitated hydroxyapatite for use as a low solubility phosphorus-rich fertilizer.

  11. Water Electrolysis for In-Situ Resource Utilization (ISRU)

    Lee, Kristopher A.

    2016-01-01

    Sending humans to Mars for any significant amount of time will require capabilities and technologies that enable Earth independence. To move towards this independence, the resources found on Mars must be utilized to produce the items needed to sustain humans away from Earth. To accomplish this task, NASA is studying In Situ Resource Utilization (ISRU) systems and techniques to make use of the atmospheric carbon dioxide and the water found on Mars. Among other things, these substances can be harvested and processed to make oxygen and methane. Oxygen is essential, not only for sustaining the lives of the crew on Mars, but also as the oxidizer for an oxygen-methane propulsion system that could be utilized on a Mars ascent vehicle. Given the presence of water on Mars, the electrolysis of water is a common technique to produce the desired oxygen. Towards this goal, NASA designed and developed a Proton Exchange Membrane (PEM) water electrolysis system, which was originally slated to produce oxygen for propulsion and fuel cell use in the Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project. As part of the Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA) project, this same electrolysis system, originally targeted at enabling in situ propulsion and power, operated in a life-support scenario. During HESTIA testing at Johnson Space Center, the electrolysis system supplied oxygen to a chamber simulating a habitat housing four crewmembers. Inside the chamber, oxygen was removed from the atmosphere to simulate consumption by the crew, and the electrolysis system's oxygen was added to replenish it. The electrolysis system operated nominally throughout the duration of the HESTIA test campaign, and the oxygen levels in the life support chamber were maintained at the desired levels.

  12. Carbon dioxide and water vapor high temperature electrolysis

    Isenberg, Arnold O.; Verostko, Charles E.

    1989-01-01

    The design, fabrication, breadboard testing, and the data base obtained for solid oxide electrolysis systems that have applications for planetary manned missions and habitats are reviewed. The breadboard tested contains sixteen tubular cells in a closely packed bundle for the electrolysis of carbon dioxide and water vapor. The discussion covers energy requirements, volume, weight, and operational characteristics related to the measurement of the reactant and product gas compositions, temperature distribution along the electrolyzer tubular cells and through the bundle, and thermal energy losses. The reliability of individual cell performance in the bundle configuration is assessed.

  13. Electrolysis test of different composite membranes at elevated temperatures

    Hansen, Martin Kalmar

    temperatures, phosphoric acid (H3PO4)[1] and zirconium phosphate (ZrP)[2] were introduced. These composite membranes were tested in an electrolysis setup. A typical electrolysis test was performed at 130°C with a galvanostatic load. Polarization curves were recorded under stationary conditions. Testing...... night at 150°C in a zirconium phosphate saturated 85wt% phosphoric acid solution. Different thicknesses of membranes were tested and as expected, the performance increased when the thickness of the membranes decreased. Furthermore composite membranes only treated with phosphoric acid or only treated...

  14. Economical hydrogen production by electrolysis using nano pulsed DC

    Dharmaraj, C.H. [Tangedco, Tirunelveli, ME Environmental Engineering (India); Adshkumar, S. [Department of Civil Engineering, Anna University of Technology Tirunelveli, Tirunelveli - 627007 (India)

    2012-07-01

    Hydrogen is an alternate renewable eco fuel. The environmental friendly hydrogen production method is electrolysis. The cost of electrical energy input is major role while fixing hydrogen cost in the conventional direct current Electrolysis. Using nano pulse DC input makes the input power less and economical hydrogen production can be established. In this investigation, a lab scale electrolytic cell developed and 0.58 mL/sec hydrogen/oxygen output is obtained using conventional and nano pulsed DC. The result shows that the nano pulsed DC gives 96.8 % energy saving.

  15. Combined electrolysis catalytic exchange (CECE) process for hydrogen isotope separation

    Hammerli, M.; Stevens, W.H.; Butler, J.P.

    1978-01-01

    Hydrogen isotopes can be separated efficiently by a process which combines an electrolysis cell with a trickle bed column packed with a hydrophobic platinum catalyst. The column effects isotopic exchange between countercurrent streams of electrolytic hydrogen and liquid water while the electrolysis cell contributes to isotope separation by virtue of the kinetic isotope effect inherent in the hydrogen evolution reaction. The main features of the CECE process for heavy water production are presented as well as a discussion of the inherent positive synergistic effects, and other advantages and disadvantages of the process. Several potential applications of the process in the nuclear power industry are discussed. 3 figures, 2 tables

  16. Fusion reactors-high temperature electrolysis (HTE)

    Fillo, J.A.

    1978-01-01

    Results of a study to identify and develop a reference design for synfuel production based on fusion reactors are given. The most promising option for hydrogen production was high-temperature electrolysis (HTE). The main findings of this study are: 1. HTE has the highest potential efficiency for production of synfuels from fusion; a fusion to hydrogen energy efficiency of about 70% appears possible with 1800 0 C HTE units and 60% power cycle efficiency; an efficiency of about 50% possible with 1400 0 C HTE units and 40% power cycle efficiency. 2. Relative to thermochemical or direct decomposition methods HTE technology is in a more advanced state of development, 3. Thermochemical or direct decomposition methods must have lower unit process or capital costs if they are to be more attractive than HTE. 4. While design efforts are required, HTE units offer the potential to be quickly run in reverse as fuel cells to produce electricity for restart of Tokamaks and/or provide spinning reserve for a grid system. 5. Because of the short timescale of the study, no detailed economic evaluation could be carried out.A comparison of costs could be made by employing certain assumptions. For example, if the fusion reactor-electrolyzer capital installation is $400/(KW(T) [$1000/KW(E) equivalent], the H 2 energy production cost for a high efficiency (about 70 %) fusion-HTE system is on the same order of magnitude as a coal based SNG plant based on 1976 dollars. 6. The present reference design indicates that a 2000 MW(th) fusion reactor could produce as much at 364 x 10 6 scf/day of hydrogen which is equivalent in heating value to 20,000 barrels/day of gasoline. This would fuel about 500,000 autos based on average driving patterns. 7. A factor of three reduction in coal feed (tons/day) could be achieved for syngas production if hydrogen from a fusion-HTE system were used to gasify coal, as compared to a conventional syngas plant using coal-derived hydrogen

  17. A comprehensive review of microbial electrolysis cells (MEC reactor designs and configurations for sustainable hydrogen gas production

    Abudukeremu Kadier

    2016-03-01

    Full Text Available Hydrogen gas has tremendous potential as an environmentally acceptable energy carrier for vehicles. A cutting edge technology called a microbial electrolysis cell (MEC can achieve sustainable and clean hydrogen production from a wide range of renewable biomass and wastewaters. Enhancing the hydrogen production rate and lowering the energy input are the main challenges of MEC technology. MEC reactor design is one of the crucial factors which directly influence on hydrogen and current production rate in MECs. The rector design is also a key factor to up-scaling. Traditional MEC designs incorporated membranes, but it was recently shown that membrane-free designs can lead to both high hydrogen recoveries and production rates. Since then multiple studies have developed reactors that operate without membranes. This review provides a brief overview of recent advances in research on scalable MEC reactor design and configurations.

  18. 2nd Generation alkaline electrolysis. Final report

    Yde, L. [Aarhus Univ. Business and Social Science - Centre for Energy Technologies (CET), Aarhus (Denmark); Kjartansdottir, C.K. [Technical Univ. of Denmark. DTU Mechanical Engineering, Kgs. Lyngby (Denmark); Allebrod, F. [Technical Univ. of Denmark. DTU Energy Conversion, DTU Risoe Campus, Roskilde (Denmark)] [and others

    2013-03-15

    The overall purpose of this project has been to contribute to this load management by developing a 2{sup nd} generation of alkaline electrolysis system characterized by being compact, reliable, inexpensive and energy efficient. The specific targets for the project have been to: 1) Increase cell efficiency to more than 88% (according to the higher heating value (HHV)) at a current density of 200 mA /cm{sup 2}; 2) Increase operation temperature to more than 100 degree Celsius to make the cooling energy more valuable; 3) Obtain an operation pressure more than 30 bar hereby minimizing the need for further compression of hydrogen for storage; 4) Improve stack architecture decreasing the price of the stack with at least 50%; 5) Develop a modular design making it easy to customize plants in the size from 20 to 200 kW; 6) Demonstrating a 20 kW 2{sup nd} generation stack in H2College at the campus of Arhus University in Herning. The project has included research and development on three different technology tracks of electrodes; an electrochemical plating, an atmospheric plasma spray (APS) and finally a high temperature and pressure (HTP) track with operating temperature around 250 deg. C and pressure around 40 bar. The results show that all three electrode tracks have reached high energy efficiencies. In the electrochemical plating track a stack efficiency of 86.5% at a current density of 177mA/cm{sup 2} and a temperature of 74.4 deg. C has been shown. The APS track showed cell efficiencies of 97%, however, coatings for the anode side still need to be developed. The HTP cell has reached 100 % electric efficiency operating at 1.5 V (the thermoneutral voltage) with a current density of 1. 1 A/cm{sup 2}. This track only tested small cells in an externally heated laboratory set-up, and thus the thermal loss to surroundings cannot be given. The goal set for the 2{sup nd} generation electrolyser system, has been to generate 30 bar pressure in the cell stack. An obstacle to be

  19. Determination of the Electronics Charge--Electrolysis of Water Method.

    Venkatachar, Arun C.

    1985-01-01

    Presents an alternative method for measuring the electronic charge using data from the electrolysis of acidified distilled water. The process (carried out in a commercially available electrolytic cell) has the advantage of short completion time so that students can determine electron charge and mass in one laboratory period. (DH)

  20. Endurance Test and Evaluation of Alkaline Water Electrolysis Cells

    Kovach, Andrew J.; Schubert, Franz H.; Chang, B. J.; Larkins, Jim T.

    1985-01-01

    The overall objective of this program is to assess the state of alkaline water electrolysis cell technology and its potential as part of a Regenerative Fuel Cell System (RFCS) of a multikilowatt orbiting powerplant. The program evaluates the endurance capabilities of alkaline electrolyte water electrolysis cells under various operating conditions, including constant condition testing, cyclic testing and high pressure testing. The RFCS demanded the scale-up of existing cell hardware from 0.1 sq ft active electrode area to 1.0 sq ft active electrode area. A single water electrolysis cell and two six-cell modules of 1.0 sq ft active electrode area were designed and fabricated. The two six-cell 1.0 sq ft modules incorporate 1.0 sq ft utilized cores, which allow for minimization of module assembly complexity and increased tolerance to pressure differential. A water electrolysis subsystem was designed and fabricated to allow testing of the six-cell modules. After completing checkout, shakedown, design verification and parametric testing, a module was incorporated into the Regenerative Fuel Cell System Breadboard (RFCSB) for testing at Life Systems, Inc., and at NASA JSC.

  1. Computer simulation of the NASA water vapor electrolysis reactor

    Bloom, A. M.

    1974-01-01

    The water vapor electrolysis (WVE) reactor is a spacecraft waste reclamation system for extended-mission manned spacecraft. The WVE reactor's raw material is water, its product oxygen. A computer simulation of the WVE operational processes provided the data required for an optimal design of the WVE unit. The simulation process was implemented with the aid of a FORTRAN IV routine.

  2. Behavior of oxygem bubbles during alkaline water electrolysis

    Wedershoven, H.M.S.; Jonge, de R.M.; Sillen, C.W.M.P.; Stralen, van S.J.D.

    1982-01-01

    Growth rate, departure radius and population of oxygen bubbles at the transparent anode during alkaline water electrolysis have been investigated experimentally. The supersaturation of dissolved oxygen in the electrolyte adjacent to the anode surface has been derived from bubble growth rates.

  3. Hydrogen production from high temperature electrolysis and fusion reactor

    Dang, V.D.; Steinberg, J.F.; Issacs, H.S.; Lazareth, O.; Powell, J.R.; Salzano, F.J.

    1978-01-01

    Production of hydrogen from high temperature electrolysis of steam coupled with a fusion reactor is studied. The process includes three major components: the fusion reactor, the high temperature electrolyzer and the power conversion cycle each of which is discussed in the paper. Detailed process design and analysis of the system is examined. A parametric study on the effect of process efficiency is presented

  4. Power to fuel using electrolysis and CO2 capture

    Mogensen, Mogens Bjerg; Graves, Christopher R.; Chatzichristodoulou, Christodoulos

    2014-01-01

    % of the cost of H2 produced by electrolysis originates from electricity cost. How much more depends on the actual electricity price and depends further on efficiency, investment cost and lifetime of electrolyzer. Investment costs are inversely proportional the current density at a given cell voltage...

  5. Analysis of cavitation effect for water purifier using electrolysis

    Shin, Dong Ho; Ko, Han Seo; Lee, Seung Ho

    2015-11-01

    Water is a limited and vital resource, so it should not be wasted by pollution. A development of new water purification technology is urgent nowadays since the original and biological treatments are not sufficient. The microbubble-aided method was investigated for removal of algal in this study since it overcomes demerits of the existing purification technologies. Thus, the cavitation effect in a venturi-type tube using the electrolysis was analyzed. Ruthenium-coated titanium plates were used as electrodes. Optimum electrode interval and applied power were determined for the electrolysis. Then, the optimized electrodes were installed in the venturi-type tube for generating cavitation. The cavitation effect could be enhanced without any byproduct by the bubbly flow induced by the electrolysis. The optimum mass flow rate and current were determined for the cavitation with the electrolysis. Finally, the visualization techniques were used to count the cell number of algal and microbubbles for the confirmation of the performance. As a result, the energy saving and high efficient water purifier was fabricated in this study. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Korean government (MEST) (No. 2013R1A2A2A01068653).

  6. Use of sodium salt electrolysis in the process of continuous ...

    Use of sodium salt electrolysis in the process of continuous modification of eutectic EN ... the plastic groundmass of the solid solution α (Al), have an effect on their ..... Onyia C, Okorie B, Neife S and Obayi C 2013 World J. Eng. Technol. 1 9. 35.

  7. High temperature electrolysis for hydrogen production using nuclear energy

    Herring, J. Stephen; O'brien, James E.; Stoots, Carl M.; Hawkes, Grant L.; Hartvigsen, Joseph J.

    2005-01-01

    High-temperature nuclear reactors have the potential for substantially increasing the efficiency of hydrogen production from water splitting, which can be accomplished via high-temperature electrolysis (HTE) or thermochemical processes. In order to achieve competitive efficiencies, both processes require high-temperature operation (∼850degC). High-temperature electrolytic water splitting supported by nuclear process heat and electricity has the potential to produce hydrogen with overall system efficiencies of 45 to 55%. At the Idaho National Laboratory, we are developing solid-oxide cells to operate in the steam electrolysis mode. The research program includes both experimental and modeling activities. Experimental results were obtained from ten-cell and 22-cell planar electrolysis stacks, fabricated by Ceramatec, Inc. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (∼200 μm thick, 64 cm 2 active area), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions, gas glow rates, and current densities. Hydrogen production rates greater than 100 normal liters per hour for 196 hours have been demonstrated. In order to evaluate the performance of large-scale HTE operations, we have developed single-cell models, based on FLUENT, and a process model, using the systems-analysis code HYSYS. (author)

  8. HIGH-TEMPERATURE ELECTROLYSIS FOR HYDROGEN PRODUCTION FROM NUCLEAR ENERGY

    James E. O& #39; Brien; Carl M. Stoots; J. Stephen Herring; Joseph J. Hartvigsen

    2005-10-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (~140 µm thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1 - 0.6), gas flow rates (1000 - 4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 90 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate.

  9. Production of aluminum metal by electrolysis of aluminum sulfide

    Minh, Nguyen Q.; Loutfy, Raouf O.; Yao, Neng-Ping

    1984-01-01

    Production of metallic aluminum by the electrolysis of Al.sub.2 S.sub.3 at 700.degree.-800.degree. C. in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

  10. Study on hydrogen production by high temperature electrolysis of steam

    Hino, Ryutaro; Aita, Hideki; Sekita, Kenji; Haga, Katsuhiro; Iwata, Tomo-o.

    1997-09-01

    In JAERI, design and R and D works on hydrogen production process have been conducted for connecting to the HTTR under construction at the Oarai Research Establishment of JAERI as a nuclear heat utilization system. As for a hydrogen production process by high-temperature electrolysis of steam, laboratory-scale experiments were carried out with a practical electrolysis tube with 12 cells connected in series. Hydrogen was produced at a maximum density of 44 Nml/cm 2 h at 950degC, and know-how of operational procedures and operational experience were also accumulated. Thereafter, a planar electrolysis cell supported by a metallic plate was fabricated in order to improve hydrogen production performance and durability against thermal cycles. In the preliminary test with the planar cell, hydrogen has been produced continuously at a maximum density of 33.6 Nml/cm 2 h at an electrolysis temperature of 950degC. This report presents typical test results mentioned above, a review of previous studies conducted in the world and R and D items required for connecting to the HTTR. (author)

  11. The labor protection and safety measures at the electrolysis department

    Galushkin, N.V.

    1995-01-01

    This chapter of monograph is devoted to labor protection and safety measures at the electrolysis department. Thus, the characteristics of dangerous and harmful production factors as well as the danger of thermal burns and thermal exposure were considered. Safety requirements on labor safety were studied.

  12. A Study on the Removal of Direct Blue 71 Dye From Textile Wastewater Produced From State Company of Cotton Industries by Electrocoagulation Using Aluminum Electrodes

    Karim Khalifa Esgair

    2017-02-01

    Full Text Available The removal of direct blue 71 dye from a prepared wastewater was studied employing batch electrocoagulation (EC cell. The electrodes of aluminum were used. The influence of process variables which include initial pH (2.0-12.0, wastewater conductivity (0.8 -12.57 mS/cm , initial dye concentration (30 -210 mg/L, electrolysis time (3-12 min, current density (10-50 mA/cm2 were studied in order to maximize the color removal from wastewater. Experimental results showed that the color removal yield increases with increasing pH until pH 6.0 after that it decreased with increasing pH. The color removal increased with increasing current density, wastewater conductivity, electrolysis time, and decreased with increasing the concentration of initial dye. The maximum color removal yield of 96.5% was obtained at pH 6.0, wastewater conductivity 9.28 mS/cm , electrolysis time 6 min ,the concentration of initial dye 6 0 mg/L and current density 30 mA/cm2 .

  13. Durability of solid oxide electrolysis cells for hydrogen production

    Hauch, A.; Hoejgaard Jensen, S.; Dalgaard Ebbesen, S.

    2007-05-15

    In the perspective of the increasing interest in renewable energy and hydrogen economy, the reversible solid oxide cells (SOCs) is a promising technology as it has the potential of providing efficient and cost effective hydrogen production by high temperature electrolysis of steam (HTES). Furthermore development of such electrolysis cells can gain from the results obtained within the R and D of SOFCs. For solid oxide electrolysis cells (SOEC) to become interesting from a technological point of view, cells that are reproducible, high performing and long-term stable need to be developed. In this paper we address some of the perspectives of the SOEC technology i.e. issues such as a potential H2 production price as low as 0.71 US dollar/kg H{sub 2} using SOECs for HTES; is there a possible market for the electrolysers? and what R and D steps are needed for the realisation of the SOEC technology? In the experimental part we present electrolysis test results on SOCs that have been optimized for fuel cell operation but applied for HTES. The SOCs are produced on a pre-pilot scale at Risoe National Laboratory. These cells have been shown to have excellent initial electrolysis performance, but the durability of such electrolysis cells are not optimal and examples of results from SOEC tests over several hundreds of hours are given here. The long-term tests have been run at current densities of -0.5 A/cm{sup 2} and -1 A/cm{sup 2}, temperatures of 850 deg. C and 950 deg. C and p(H{sub 2}O)/p(H{sub 2}) of 0.5/0.5 and 0.9/0.1. Long-term degradation rates are shown to be up to 5 times higher for SOECs compared to similar SOFC testing. Furthermore, hydrogen and synthetic fuel production prices are calculated using the experimental results from long-term electrolysis test as input and a short outlook for the future work on SOECs will be given as well. (au)

  14. Prediction of the fate of Hg and other contaminants in soil around a former chlor-alkali plant using Fuzzy Hierarchical Cross-Clustering approach.

    Frenţiu, Tiberiu; Ponta, Michaela; Sârbu, Costel

    2015-11-01

    An associative simultaneous fuzzy divisive hierarchical algorithm was used to predict the fate of Hg and other contaminants in soil around a former chlor-alkali plant. The algorithm was applied on several natural and anthropogenic characteristics of soil including water leachable, mobile, semi-mobile, non-mobile fractions and total Hg, Al, Ba, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Sr, Zn, water leachable fraction of Cl(-), NO3(-) and SO4(2)(-), pH and total organic carbon. The cross-classification algorithm provided a divisive fuzzy partition of the soil samples and associated characteristics. Soils outside the perimeter of the former chlor-alkali plant were clustered based on the natural characteristics and total Hg. In contaminated zones Hg speciation becomes relevant and the assessment of species distribution is necessary. The descending order of concentration of Hg species in the test site was semi-mobile>mobile>non-mobile>water-leachable. Physico-chemical features responsible for similarities or differences between uncontaminated soil samples or contaminated with Hg, Cu, Zn, Ba and NO3(-) were also highlighted. Other characteristics of the contaminated soil were found to be Ca, sulfate, Na and chloride, some of which with influence on Hg fate. The presence of Ca and sulfate in soil induced a higher water leachability of Hg, while Cu had an opposite effect by forming amalgam. The used algorithm provided an in-deep understanding of processes involving Hg species and allowed to make prediction of the fate of Hg and contaminants linked to chlor-alkali-industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Electrochemical struvite precipitation from digestate with a fluidized bed cathode microbial electrolysis cell.

    Cusick, Roland D; Ullery, Mark L; Dempsey, Brian A; Logan, Bruce E

    2014-05-01

    Microbial electrolysis cells (MECs) can be used to simultaneously convert wastewater organics to hydrogen and precipitate struvite, but scale formation at the cathode surface can block catalytic active sites and limit extended operation. To promote bulk phase struvite precipitation and minimize cathode scaling, a two-chamber MEC was designed with a fluidized bed to produce suspended particles and inhibit scale formation on the cathode surface. MEC operation elevated the cathode pH to between 8.3 and 8.7 under continuous flow conditions. Soluble phosphorus removal using digester effluent ranged from 70 to 85% with current generation, compared to 10-20% for the control (open circuit conditions). At low current densities (≤2 mA/m(2)), scouring of the cathode by fluidized particles prevented scale accumulation over a period of 8 days. There was nearly identical removal of soluble phosphorus and magnesium from solution, and an equimolar composition in the collected solids, supporting phosphorus removal by struvite formation. At an applied voltage of 1.0 V, energy consumption from the power supply and pumping (0.2 Wh/L, 7.5 Wh/g-P) was significantly less than that needed by other struvite formation methods based on pH adjustment such as aeration and NaOH addition. In the anode chamber, current generation led to COD oxidation (1.1-2.1 g-COD/L-d) and ammonium removal (7-12 mM) from digestate amended with 1 g/L of sodium acetate. These results indicate that a fluidized bed cathode MEC is a promising method of sustainable electrochemical nutrient and energy recovery method for nutrient rich wastewaters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Electrochemical struvite precipitation from digestate with a fluidized bed cathode microbial electrolysis cell

    Cusick, Roland D.

    2014-05-01

    Microbial electrolysis cells (MECs) can be used to simultaneously convert wastewater organics to hydrogen and precipitate struvite, but scale formation at the cathode surface can block catalytic active sites and limit extended operation. To promote bulk phase struvite precipitation and minimize cathode scaling, a two-chamber MEC was designed with a fluidized bed to produce suspended particles and inhibit scale formation on the cathode surface. MEC operation elevated the cathode pH to between 8.3 and 8.7 under continuous flow conditions. Soluble phosphorus removal using digester effluent ranged from 70 to 85% with current generation, compared to 10-20% for the control (open circuit conditions). At low current densities (≤2mA/m2), scouring of the cathode by fluidized particles prevented scale accumulation over a period of 8 days. There was nearly identical removal of soluble phosphorus and magnesium from solution, and an equimolar composition in the collected solids, supporting phosphorus removal by struvite formation. At an applied voltage of 1.0V, energy consumption from the power supply and pumping (0.2Wh/L, 7.5Wh/g-P) was significantly less than that needed by other struvite formation methods based on pH adjustment such as aeration and NaOH addition. In the anode chamber, current generation led to COD oxidation (1.1-2.1g-COD/L-d) and ammonium removal (7-12mM) from digestate amended with 1g/L of sodium acetate. These results indicate that a fluidized bed cathode MEC is a promising method of sustainable electrochemical nutrient and energy recovery method for nutrient rich wastewaters. © 2014 Elsevier Ltd.

  17. Electrochemical struvite precipitation from digestate with a fluidized bed cathode microbial electrolysis cell

    Cusick, Roland D.; Ullery, Mark L.; Dempsey, Brian A.; Logan, Bruce E.

    2014-01-01

    Microbial electrolysis cells (MECs) can be used to simultaneously convert wastewater organics to hydrogen and precipitate struvite, but scale formation at the cathode surface can block catalytic active sites and limit extended operation. To promote bulk phase struvite precipitation and minimize cathode scaling, a two-chamber MEC was designed with a fluidized bed to produce suspended particles and inhibit scale formation on the cathode surface. MEC operation elevated the cathode pH to between 8.3 and 8.7 under continuous flow conditions. Soluble phosphorus removal using digester effluent ranged from 70 to 85% with current generation, compared to 10-20% for the control (open circuit conditions). At low current densities (≤2mA/m2), scouring of the cathode by fluidized particles prevented scale accumulation over a period of 8 days. There was nearly identical removal of soluble phosphorus and magnesium from solution, and an equimolar composition in the collected solids, supporting phosphorus removal by struvite formation. At an applied voltage of 1.0V, energy consumption from the power supply and pumping (0.2Wh/L, 7.5Wh/g-P) was significantly less than that needed by other struvite formation methods based on pH adjustment such as aeration and NaOH addition. In the anode chamber, current generation led to COD oxidation (1.1-2.1g-COD/L-d) and ammonium removal (7-12mM) from digestate amended with 1g/L of sodium acetate. These results indicate that a fluidized bed cathode MEC is a promising method of sustainable electrochemical nutrient and energy recovery method for nutrient rich wastewaters. © 2014 Elsevier Ltd.

  18. Purification and detoxification of petroleum refinery wastewater by electrocoagulation process.

    Gousmi, N; Sahmi, A; Li, H Z; Poncin, S; Djebbar, R; Bensadok, K

    2016-09-01

    The treatment of synthetic oily wastewater having the characteristics of a typical petroleum refinery wastewater (PRW) by electrocoagulation (EC) using iron and aluminum electrodes was conducted in an electrolytic reactor equipped with fluid recirculation. During the treatment, the emulsion stability was followed by the measurement of Zeta potential and particle sizes. Effects of some operating conditions such as electrodes material, current density and electrolysis time on removal efficiencies of turbidity, and chemical oxygen demand (COD) were investigated in detail. The PRW purification by the EC process was found to be the most effective using aluminum as the anode and cathode, current density of 60 A/m(2) and 30 min of electrolysis time. Under these conditions, the process efficiencies were 83.52% and 99.94%, respectively, for COD and turbidity removals which correspond to final values of 96 mg O2/L and 0.5 NTU. A moderate energy consumption (0.341 kWh) was needed to treat 1 m(3) of PRW. Besides, the ecotoxicity test proved that toxic substances presented in the PRW, and those inhibiting the germination growth of whet, were eliminated by the EC technique.

  19. Real-time monitoring of a microbial electrolysis cell using an electrical equivalent circuit model.

    Hussain, S A; Perrier, M; Tartakovsky, B

    2018-04-01

    Efforts in developing microbial electrolysis cells (MECs) resulted in several novel approaches for wastewater treatment and bioelectrosynthesis. Practical implementation of these approaches necessitates the development of an adequate system for real-time (on-line) monitoring and diagnostics of MEC performance. This study describes a simple MEC equivalent electrical circuit (EEC) model and a parameter estimation procedure, which enable such real-time monitoring. The proposed approach involves MEC voltage and current measurements during its operation with periodic power supply connection/disconnection (on/off operation) followed by parameter estimation using either numerical or analytical solution of the model. The proposed monitoring approach is demonstrated using a membraneless MEC with flow-through porous electrodes. Laboratory tests showed that changes in the influent carbon source concentration and composition significantly affect MEC total internal resistance and capacitance estimated by the model. Fast response of these EEC model parameters to changes in operating conditions enables the development of a model-based approach for real-time monitoring and fault detection.

  20. Treatment of oilfield produced water by anaerobic process coupled with micro-electrolysis.

    Li, Gang; Guo, Shuhai; Li, Fengmei

    2010-01-01

    Treatment of oilfield produced water was investigated using an anaerobic process coupled with micro-electrolysis (ME), focusing on changes in chemical oxygen demand (COD) and biodegradability. Results showed that COD exhibited an abnormal change in the single anaerobic system in which it increased within the first 168 hr, but then decreased to 222 mg/L after 360 hr. The biological oxygen demand (five-day) (BODs)/COD ratio of the water increased from 0.05 to 0.15. Hydrocarbons in the wastewater, such as pectin, degraded to small molecules during the hydrolytic acidification process. Comparatively, the effect of ME was also investigated. The COD underwent a slight decrease and the BOD5/COD ratio of the water improved from 0.05 to 0.17 after ME. Removal of COD was 38.3% under the idealized ME conditions (pH 6.0), using iron and active carbon (80 and 40 g/L, respectively). Coupling the anaerobic process with ME accelerated the COD removal ratio (average removal was 53.3%). Gas chromatography/mass spectrometry was used to analyze organic species conversion. This integrated system appeared to be a useful option for the treatment of water produced in oilfields.

  1. Characterisation of wastewater for modelling of wastewater ...

    Bio-process modelling is increasingly used in design, modification and troubleshooting of wastewater treatment plants (WWTPs). Characterisation of the influent wastewater to a WWTP is an important part of developing such a model. The characterisation required for modelling is more detailed than that routinely employed ...

  2. Time efficiency of tritium measurement in the environmental water by electrolysis enrichment (2)

    Ogata, Y.; Koganezawa, T.; Iida, T.

    2003-01-01

    Now the electrolysis enrichment is necessary for tritium measurement of the environmental water in Japan. Generally, the electrolysis needs distilling the sample water before and after the electrolysis. To save the time to measure, it was investigated that a possibility of the omission of the distillation after the electrolysis and of the substitution the filtration for the distillation before the electrolysis. The electrolysis was carried out with a device using solid polymer electrolyte layer, which was recently developed in Japan. Initially, impurities eluted from the device were measured by enrichment of ultra pure water. Although some impurities eluted from the layer, the concentrations were so low that the enriched water brought ineffectual quenching for the liquid scintillation counting. Secondly, two filtration methods, i.e.; micro filtration with the pore size of 0.1 μm and reverse osmosis, were applied to eliminate the impurities in the environmental waters before the electrolysis. Although the impurity concentrations in the samples by the filtrations were higher than those by the distillation, the filtered water brought only slight quenching. However, the frequent electrolysis of the water treated with the micro filtration caused degradation of the electrolysis cell. Consequently, the distillation after the electrolysis may omit, and the reverse osmosis treatment may alternate the distillation before the electrolysis. Improving the treatment will not only save the time and labor but also reduce the error with the treatment. The measurement technique proposed here will take 25 hours to measure one sample using the electrolysis device produced commercially. A hypothetic electrolysis device of which final sample volume were 20 cm 3 could allow the measuring time of 10 hours. (author)

  3. Bio-Electro-Fenton process for the degradation of Non-Steroidal Anti-Inflammatory Drugs in wastewater

    Nadais, Helena; Li, Xiaohu; Alves, Nadine

    2018-01-01

    Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are ubiquitous municipal wastewater pollutants of which several are resistant to degradation in conventional wastewater treatment, and represent a major environmental health concern worldwide. An alternative treatment, the bio-electro-Fenton process......, has received increasing attention in past years. In this process the strong oxidant •HO is formed using the electrons derived from bacterial oxidation of organic substrate. In this work, a laboratory scale microbial electrolysis cell based bio-electro-Fenton process was developed for the treatment...

  4. Removal of colour and COD from wastewater containing acid blue 22 by electrochemical oxidation

    Panizza, Marco [Dipartimento di Ingegneria Chimica e di Processo ' G.B. Bonino' , Universita degli Studi di Genova, p.le J.F. Kennedy 1, 16129 Genova (Italy)], E-mail: marco.panizza@unige.it; Cerisola, Giacomo [Dipartimento di Ingegneria Chimica e di Processo ' G.B. Bonino' , Universita degli Studi di Genova, p.le J.F. Kennedy 1, 16129 Genova (Italy)

    2008-05-01

    Electrochemical oxidation of synthetic wastewater containing acid blue 22 on a boron-doped diamond electrode (BDD) was studied, using cyclic voltammetry and bulk electrolysis. The influence of current density, dye concentration, flow rate, and temperature was investigated, in order to find the best conditions for COD and colour removal. It was found that, during oxidation, a polymeric film, causing BDD deactivation, was formed in the potential region of water stability, and that it was removed by anodic polarisation at high potentials in the region of O{sub 2} evolution. Bulk electrolysis results showed that the electrochemical process was suitable for completely removing COD and effectively decolourising wastewaters, due to the production of hydroxyl radicals on the diamond surface. In particular, under optimal experimental conditions of flow rates (i.e. 300 dm{sup 3} h{sup -1}) and current density (i.e. 20 mA cm{sup -2}), 97% of COD was removed in 12 h electrolysis, with 70 kWh m{sup -3}energy consumption.

  5. Removal of colour and COD from wastewater containing acid blue 22 by electrochemical oxidation

    Panizza, Marco; Cerisola, Giacomo

    2008-01-01

    Electrochemical oxidation of synthetic wastewater containing acid blue 22 on a boron-doped diamond electrode (BDD) was studied, using cyclic voltammetry and bulk electrolysis. The influence of current density, dye concentration, flow rate, and temperature was investigated, in order to find the best conditions for COD and colour removal. It was found that, during oxidation, a polymeric film, causing BDD deactivation, was formed in the potential region of water stability, and that it was removed by anodic polarisation at high potentials in the region of O 2 evolution. Bulk electrolysis results showed that the electrochemical process was suitable for completely removing COD and effectively decolourising wastewaters, due to the production of hydroxyl radicals on the diamond surface. In particular, under optimal experimental conditions of flow rates (i.e. 300 dm 3 h -1 ) and current density (i.e. 20 mA cm -2 ), 97% of COD was removed in 12 h electrolysis, with 70 kWh m -3 energy consumption

  6. Temporal Microbial Community Dynamics in Microbial Electrolysis Cells – Influence of Acetate and Propionate Concentration

    Rao, Hari Ananda

    2017-07-20

    Microbial electrolysis cells (MECs) are widely considered as a next generation wastewater treatment system. However, fundamental insight on the temporal dynamics of microbial communities associated with MEC performance under different organic types with varied loading concentrations is still unknown, nevertheless this knowledge is essential for optimizing this technology for real-scale applications. Here, the temporal dynamics of anodic microbial communities associated with MEC performance was examined at low (0.5 g COD/L) and high (4 g COD/L) concentrations of acetate or propionate, which are important intermediates of fermentation of municipal wastewaters and sludge. The results showed that acetate-fed reactors exhibited higher performance in terms of maximum current density (I: 4.25 ± 0.23 A/m), coulombic efficiency (CE: 95 ± 8%), and substrate degradation rate (98.8 ± 1.2%) than propionate-fed reactors (I: 2.7 ± 0.28 A/m; CE: 68 ± 9.5%; substrate degradation rate: 84 ± 13%) irrespective of the concentrations tested. Despite of the repeated sampling of the anodic biofilm over time, the high-concentration reactors demonstrated lower and stable performance in terms of current density (I: 1.1 ± 0.14 to 4.2 ± 0.21 A/m), coulombic efficiency (CE: 44 ± 4.1 to 103 ± 7.2%) and substrate degradation rate (64.9 ± 6.3 to 99.7 ± 0.5%), while the low-concentration reactors produced higher and dynamic performance (I: 1.1 ± 0.12 to 4.6 ± 0.1 A/m; CE: 52 ± 2.5 to 105 ± 2.7%; substrate degradation rate: 87.2 ± 0.2 to 99.9 ± 0.06%) with the different substrates tested. Correlating reactor\\'s performance with temporal dynamics of microbial communities showed that relatively similar anodic microbial community composition but with varying relative abundances was observed in all the reactors despite differences in the substrate and concentrations tested. Particularly, Geobacter was the predominant bacteria on the anode biofilm of all MECs over time suggesting its

  7. Development of a static feed water electrolysis system

    Schubert, F. H.; Lantz, J. B.; Hallick, T. M.

    1982-01-01

    A one person level oxygen generation subsystem was developed and production of the one person oxygen metabolic requirements, 0.82 kg, per day was demonstrated without the need for condenser/separators or electrolyte pumps. During 650 hours of shakedown, design verification, and endurance testing, cell voltages averaged 1.62 V at 206 mA/sq cm and at average operating temperature as low as 326 K, virtually corresponding to the state of the art performance previously established for single cells. This high efficiency and low waste heat generation prevented maintenance of the 339 K design temperature without supplemental heating. Improved water electrolysis cell frames were designed, new injection molds were fabricated, and a series of frames was molded. A modified three fluid pressure controller was developed and a static feed water electrolysis that requires no electrolyte in the static feed compartment was developed and successfully evaluated.

  8. Numerical modeling of hypolimnetic oxygenation by electrolysis of water

    Jaćimović Nenad M.

    2017-01-01

    Full Text Available The paper presents a novel method for hypolimnetic oxygenation by electrolysis of water. The performance of the method is investigated by the laboratory and the field experiment. The laboratory experiment is conducted in a 90 L vessel, while the field experiment is conducted at the lake Biwa in Japan. In order to provide a better insight into involved processes, a numerical model for simulation of bubble flow is developed with consideration of gas compressibility and oxygen dissolution. The model simultaneously solves 3-D volume averaged two-fluid governing equations. Developed model is firstly verified by simulation of bubble flow experiments, reported in the literature, where good qualitative agreement between measured and simulated results is observed. In the second part, the model is applied for simulation of conducted water electrolysis experiments. The model reproduced the observed oxygen concentration dynamics reasonably well. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 37009

  9. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    Saksono, Nelson; Febiyanti, Irine Ayu, E-mail: irine.ayu41@ui.ac.id; Utami, Nissa; Ibrahim [Department of Chemical Engineering, Universitas Indonesia, Depok 16424, Indonesia Phone: +62217863516, Fax: +62217863515 (Indonesia)

    2015-12-29

    Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H{sub 2}O{sub 2} amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical current throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode.

  10. HYFIRE: a tokamak/high-temperature electrolysis system

    Fillo, J.A.; Powell, J.P.; Benenati, R.; Varljen, T.C.; Chi, J.W.H.; Karbowski, J.S.

    1981-01-01

    The HYFIRE studies to date have investigated a number of technical approaches for using the thermal energy produced in a high-temperature Tokamak blanket to provide the electrical and thermal energy required to drive a high-temperature (> 1000 0 C) water electrolysis process. Current emphasis is on two design points, one consistent with electrolyzer peak inlet temperatures of 1400 0 C, which is an extrapolation of present experience, and one consistent with a peak electrolyzer temperature of 1100 0 C. This latter condition is based on current laboratory experience with high-temperature solid electrolyte fuel cells. Our major conclusion to date is that the technical integration of fusion and high-temperature electrolysis appears to be feasible and that overall hydrogen production efficiencies of 50 to 55% seem possible

  11. Direct LiT Electrolysis in a Metallic Fusion Blanket

    Olson, Luke [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-30

    A process that simplifies the extraction of tritium from molten lithium-based breeding blankets was developed. The process is based on the direct electrolysis of lithium tritide using a ceramic Li ion conductor that replaces the molten salt extraction step. Extraction of tritium in the form of lithium tritide in the blankets/targets of fusion/fission reactors is critical in order to maintain low concentrations. This is needed to decrease the potential tritium permeation to the surroundings and large releases from unforeseen accident scenarios. Extraction is complicated due to required low tritium concentration limits and because of the high affinity of tritium for the blanket. This work identified, developed and tested the use of ceramic lithium ion conductors capable of recovering hydrogen and deuterium through an electrolysis step at high temperatures.

  12. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and an immobilized electrolyte allow for reversible operation as electrolysis cell or fuel...... cell. In the present work we demonstrate the application of hydrophobic, porous, and electro-catalytically active gas diffusion electrodes. PTFE particles and silver nanowires as electro-catalysts were used in the gas diffusion electrodes. Impedance spectroscopy and cyclic voltammetry were performed...... to determine the cell characteristics. The thickness of the electrolyte matrix was only 200 µm, thereby achieving a serial resistance and area specific resistance of 60 mΩ cm2 and 150 mΩ cm2, respectively, at 200 °C and 20 bar. A new production method was developed to increase the cell size from lab scale (1...

  13. Foam Based Gas Diffusion Electrodes for Reversible Alkaline Electrolysis Cells

    Allebrod, Frank; Chatzichristodoulou, Christodoulos; Mogensen, Mogens Bjerg

    2014-01-01

    Alkaline electrolysis cells operated at 250 °C and 40 bar have shown to be able to convert electrical energy into chemical energy in the form of hydrogen at very high efficiencies and power densities. Foam based gas diffusion electrodes and a liquid immobilized electrolyte allow the operation...... of the newly designed electrolysis cell as a fuel cell, but condensation of steam may lead to blocked pores, thereby inhibiting gas diffusion and decreasing the performance of the cell. In the here presented work we present the application of a hydrophobic, porous, and electro-catalytically active layer...... the electrochemical characteristics of the cell. The thickness of the electrolyte matrix was reduced to 200 µm, thereby achieving a serial resistance and area specific resistance as low as 60 mΩ cm2 and 150 mΩ cm2, respectively, at a temperature of 200 °C and 20 bar pressure. A new production method was developed...

  14. Water electrolysis for hydrogen production in Brazilian perspective

    Saliba-Silva, Adonis Marcelo; Carvalho, Fatima M.S.; Bergamaschi, Vanderlei Sergio; Linardi, Marcelo [Instituto de Pesquisas Energeticas e Nucleares (CCCH/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Fuel Cell and Hydrogen Center], Email: saliba@ipen.br

    2009-07-01

    Hydrogen is a promising energy carrier, which potentially could replace the fossil fuels used in the transportation and distributed energy sector of Brazilian economy. Fossil fuels are polluting by carbogenic emissions from their combustion, being so co-responsible for present global warming. However, no large scale, cost-effective, environmentally non-carbogenic hydrogen production process is currently available for commercialization. There are feasible possibilities to use electrolysis as one of the main sources of hydrogen, especially thinking on combination with renewable sources of energy, mainly eolic and solar. In this work some perspectives for Brazilian energy context is presented, where electrolysis combined with renewable power source and fuel cell power generation would be a good basis to improve the distributed energy supply for remote areas, where the electricity grid is not present or is deficient. (author)

  15. Direct LiT Electrolysis in a Metallic Fusion Blanket

    Olson, Luke

    2016-01-01

    A process that simplifies the extraction of tritium from molten lithium-based breeding blankets was developed. The process is based on the direct electrolysis of lithium tritide using a ceramic Li ion conductor that replaces the molten salt extraction step. Extraction of tritium in the form of lithium tritide in the blankets/targets of fusion/fission reactors is critical in order to maintain low concentrations. This is needed to decrease the potential tritium permeation to the surroundings and large releases from unforeseen accident scenarios. Extraction is complicated due to required low tritium concentration limits and because of the high affinity of tritium for the blanket. This work identified, developed and tested the use of ceramic lithium ion conductors capable of recovering hydrogen and deuterium through an electrolysis step at high temperatures.

  16. Hydrogen production from fusion reactors coupled with high temperature electrolysis

    Fillo, J.A.; Powell, J.R.; Steinberg, M.

    The decreasing availability of fossil fuels emphasizes the need to develop systems which will produce synthetic fuel to substitute for and complement the natural supply. An important first step in the synthesis of liquid and gaseous fuels is the production of hydrogen. Thermonuclear fusion offers an inexhaustible source of energy for the production of hydrogen from water. Processes which may be considered for this purpose include electrolysis, thermochemical decomposition or thermochemical-electrochemical hybrid cycles. Preliminary studies at Brookhaven indicate that high temperature electrolysis has the highest potential efficiency for production of hydrogen from fusion. Depending on design electric generation efficiencies of approximately 40 to 60 percent and hydrogen production efficiencies of approximately 50 to 70 percent are projected for fusion reactors using high temperature blankets

  17. Natural gas anodes for aluminium electrolysis in molten fluorides.

    Haarberg, Geir Martin; Khalaghi, Babak; Mokkelbost, Tommy

    2016-08-15

    Industrial primary production of aluminium has been developed and improved over more than 100 years. The molten salt electrolysis process is still suffering from low energy efficiency and considerable emissions of greenhouse gases (CO2 and PFC). A new concept has been suggested where methane is supplied through the anode so that the CO2 emissions may be reduced significantly, the PFC emissions may be eliminated and the energy consumption may decrease significantly. Porous carbon anodes made from different graphite grades were studied in controlled laboratory experiments. The anode potential, the anode carbon consumption and the level of HF gas above the electrolyte were measured during electrolysis. In some cases it was found that the methane oxidation was effectively participating in the anode process.

  18. Comparison of ultrasound-assisted and traditional caustic leaching of spent cathode carbon (SCC) from aluminum electrolysis.

    Xiao, Jin; Yuan, Jie; Tian, Zhongliang; Yang, Kai; Yao, Zhen; Yu, Bailie; Zhang, Liuyun

    2018-01-01

    The spent cathode carbon (SCC) from aluminum electrolysis was subjected to caustic leaching to investigate the different effects of ultrasound-assisted and traditional methods on element fluorine (F) leaching rate and leaching residue carbon content. Sodium hydroxide (NaOH) dissolved in deionized water was used as the reaction system. Through single-factor experiments and a comparison of two leaching techniques, the optimum F leaching rate and residue carbon content for ultrasound-assisted leaching process were obtained at a temperature of 70°C, residue time of 40min, initial mass ratio of alkali to SCC (initial alkali-to-material ratio) of 0.6, liquid-to-solid ratio of 10mL/g, and ultrasonic power of 400W, respectively. Under the optimal conditions, the leaching residue carbon content was 94.72%, 2.19% larger than the carbon content of traditional leaching residue. Leaching wastewater was treated with calcium chloride (CaCl 2 ) and bleaching powder and the treated wastewater was recycled caustic solution. All in all, benefiting from advantage of the ultrasonication effects, ultrasound-assisted caustic leaching on spent cathode carbon had 55.6% shorter residue time than the traditional process with a higher impurity removal rate. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Hydrogen generation through static-feed water electrolysis

    Jensen, F. C.; Schubert, F. H.

    1975-01-01

    A static-feed water electrolysis system (SFWES), developed under NASA sponsorship, is presented for potential applicability to terrestrial hydrogen production. The SFWES concept uses (1) an alkaline electrolyte to minimize power requirements and materials-compatibility problems, (2) a method where the electrolyte is retained in a thin porous matrix eliminating bulk electrolyte, and (3) a static water-feed mechanism to prevent electrode and electrolyte contamination and to promote system simplicity.

  20. Application of mercury cathode electrolysis to fission-product separation

    Besson, A.; Prigent, Y.; Van-Kote, F.

    1969-01-01

    A method involving controlled potential mercury cathode electrolysis has been developed to separate fission products. It allows the radiochemical determination of Ag, Cd, Pd, Rh, Ru, Sn, Te, Sb and Mo from solutions of fission products highly concentrated in mineral salts. The general procedure consists in three main steps: electrolytic amalgam generation, destruction of amalgams and ultimate purification of elements by other means. Electrolytic operations last about five hours. Chemical yields lie between 10 per cent and 70 per cent. (authors) [fr

  1. Electrolysis of plutonium in neutral and basic solutions

    1978-01-01

    Experiments were conducted on electrolysis of Pu in waste streams. Removal of Pu by this process is maximum at pH 11. Runs on an actual waste stream showed that: Pu can be electrolyzed from neutral or basic solutions down to 10 -10 g/l. Am can also be removed. The removal efficiency is pH dependent. The deposits can be removed by acid leaching

  2. Polybenzimidazole membranes for zero gap alkaline electrolysis cells

    Kraglund, Mikkel Rykær; Aili, David; Christensen, Erik

    Membranes of m-PBI doped in KOH (aq), 15-35 wt%, show high ionic conductivity in the temperature range 20-80 ºC. In electrolysis cells with nickel foam electrodes m-PBI membranesprovide low internal resistance. With a 60 µm membraneat 80ºC in 20 wt% KOH,1000 mA/cm2 is achieved at 2.25....

  3. Can high temperature steam electrolysis function with geothermal heat?

    Sigurvinsson, J.; Mansilla, C.; Werkoff, F.; Lovera, P.

    2007-01-01

    It is possible to improve the performance of electrolysis processes by operating at a high temperature. This leads to a reduction in electricity consumption but requires a part of the energy necessary for the dissociation of water to be in the form of thermal energy. Iceland produces low cost electricity and very low cost geothermal heat. However, the temperature of geothermal heat is considerably lower than the temperature required at the electrolyser's inlet, making heat exchangers necessary to recuperate part of the heat contained in the gases at the electrolyser's outlet. A techno-economic optimisation model devoted to a high-temperature electrolysis (HTE) process which includes electrolysers as well as a high temperature heat exchanger network was created. Concerning the heat exchangers, the unit costs used in the model are based on industrial data. For the electrolyser cells, the unit cost scaling law and the physical sub-model we used were formulated using analogies with solid oxide fuel cells. The method was implemented in a software tool, which performs the optimisation using genetic algorithms. The first application of the method is done by taking into account the prices of electricity and geothermal heat in the Icelandic context. It appears that even with a geothermal temperature as low as 230 degrees C, the HTE could compete with alkaline electrolysis. (authors)

  4. The electrolysis time on electrosynthesis of hydroxyapatite with bipolar membrane

    Nur, Adrian; Jumari, Arif; Budiman, Anatta Wahyu; Puspitaningtyas, Stella Febianti; Cahyaningrum, Suci; Nazriati, Nazriati; Fajaroh, Fauziatul

    2018-02-01

    The electrochemical method with bipolar membrane has been successfully used for the synthesis of hydroxyapatite. In this work, we have developed 2 chambers electrolysis system separated by a bipolar membrane. The membrane was used to separate cations (H+ ions produced by the oxidation of water at the anode) and anions (OH- ions produced by the reduction of water at the cathode). With this system, we have designed that OH- ions still stay in the anions chamber because OH- ions was very substantial in the hydroxyapatite particles formation. The aim of this paper was to compare the electrolysis time on electrosynthesis of hydroxyapatite with and without the bipolar membrane. The electrosynthesis was performed at 500 mA/cm2 for 0.5 to 2 hours at room temperature and under ultrasonic cleaner to void agglomeration with and without the bipolar membrane. The electrosynthesis of hydroxyapatite with the bipolar membrane more effective than without the bipolar membrane. The hydroxyapatite has been appeared at 0.5 h of the electrolysis time with the bipolar membrane (at the cathode chamber) while it hasn't been seen without the bipolar membrane. The bipolar membrane prevents OH- ions migrate to the cation chamber. The formation of HA becomes more effective because OH- ions just formed HA particle.

  5. Tritium separation from light and heavy water by bipolar electrolysis

    Ramey, D.W.; Petek, M.; Taylor, R.D.; Kobisk, E.H.; Ramey, J.; Sampson, C.A.

    1979-10-01

    Use of bipolar electrolysis with countercurrent electrolyte flow to separate hydrogen isotopes was investigated for the removal of tritium from light water effluents or from heavy water moderator. Deuterium-tritium and protium-tritium separation factors occurring on a Pd-25% Ag bipolar electrode were measured to be 2.05 to 2.16 and 11.6 to 12.4 respectively, at current densities between 0.21 and 0.50 A cm -2 , and at 35 to 90 0 C. Current densities up to 0.3 A cm -2 have been achieved in continuous operation, at 80 to 90 0 C, without significant gas formation on the bipolar electrodes. From the measured overvoltage at the bipolar electrodes and the electrolyte conductivity the power consumption per stage was calculated to be 3.0 kwh/kg H 2 O at 0.2 A cm -2 and 5.0 kwh/kg H 2 O at 0.5 A cm -2 current density, compared to 6.4 and 8.0 kwh/kg H 2 O for normal electrolysis. A mathematical model derived for hydrogen isotope separation by bipolar electrolysis, i.e., for a square cascade, accurately describes the results for protium-tritium separation in two laboratory scale, multistage experiments with countercurrent electrolyte flow; the measured tiritum concentration gradient through the cascade agreed with the calculated values

  6. NOx generation method from recovered nitric acid by electrolysis

    Suzuki, Y.; Shimizu, H.; Inoue, M.; Fujiso, M.; Shibuya, M.; Iwamoto, F.; Outou, Y.; Ochi, E.; Tsuyuki, T.

    1998-01-01

    An R and D has been conducted on an electrolytic NO x generation process utilizing recovered nitric acid from a PUREX reprocessing plant. The purpose of the study is to drastically reduce the amount of low-level-liquid waste(LLW). The research program phase-1, constituting mainly of electrochemical reaction mechanism study, material balance evaluation and process design study, finished in 1995. The results were presented in the previous papers). The research program phase-2 has started in 1995. The schedule is as follows: FY 1991-1994: Research program phase-1 Basic study using electrolysis equipment with 100-700 cm 2 electrodes FY 1995-1999: Research program phase-2 Process performance test by larger scale electrolysis equipment with 3.6 m 2 electrodes - pilot plant design (FY 1995) - pilot plant construction (FY 1996) - engineering data acquisition (FY 1997-1999). The process consists of many unit operations such as electrolysis, oxidation, nitric acid concentration, NO x compression and storage, NO x recovery, off-gas treatment and acid supplier. This paper outlines the pilot test plant. (author)

  7. Carbon dioxide electrolysis using a ceramic electrolyte. [for space processing

    Erstfeld, T. E.; Mullins, O., Jr.; Williams, R. J.

    1979-01-01

    This paper discusses the results of an experimental study of the electrical aspects of carbon dioxide electrolysis using a ceramic electrolyte. The electrolyte compositions used in this study are 8% Y2O3 stabilized ZrO2, 7.5% CaO stabilized ZrO2, and 5% Y2O3 stabilized ThO2. Results indicate that the 8% Y2O3 stabilized ZrO2 is the best material to use for electrolysis, in terms of current as a function of voltage and temperature, and in terms of efficiency of oxide ion flow through it. The poorest results were obtained with the 5% Y2O3 stabilized ThO2 composition. An electrolysis system which might be employed to reclaim oxygen and carbon from effluents of space manufacturing, assuming that an industry would have to electrolyze 258,000 tonnes of CO2 per year, is predicted to require a total cell area of 110,000 sq m of 1 mm thickness and electrical capacity of 441 MW.

  8. Production of hydrogen using composite membrane in PEM water electrolysis

    Santhi priya, E.L.; Mahender, C.; Mahesh, Naga; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad-500 085, A.P (India); Anjaneyulu, Y. [Director, TLGVRC, JSU Box 18739, JSU, Jackson, MS 32917-0939 (United States)

    2012-07-01

    Electrolysis of water is the best known technology till today to produce hydrogen. The only practical way to produce hydrogen using renewable energy sources is by proton exchange membrane (PEM) water electrolysis. The most commonly used PEM membrane is Nafion. Composite membrane of TiO2 is synthesized by casting method using Nafion 5wt% solution. RuO2 is used as anode and 10 wt% Pd on activated carbon is used as cathode in the water electrolyser system. The performance of this Composite membrane is studied by varying voltage range 1.8 to 2.6V with respect to hydrogen yield and at current density 0.1, 0.2, 0.3, 0.4, and 0.5(A cm-2). This Composite membrane has been tested using in-house fabricated single cell PEM water electrolysis cell with 10cm2 active area at temperatures ranging from 30,45,65 850c and at 1 atmosphere pressure.

  9. Endurance test and evaluation of alkaline water electrolysis cells

    Burke, K. A.; Schubert, F. H.

    1981-01-01

    Utilization in the development of multi-kW low orbit power systems is discussed. The following technological developments of alkaline water electrolysis cells for space power application were demonstrated: (1) four 92.9 cm2 single water electrolysis cells, two using LST's advanced anodes and two using LST's super anodes; (2) four single cell endurance test stands for life testing of alkaline water electrolyte cells; (3) the solid performance of the advanced electrode and 355 K; (4) the breakthrough performance of the super electrode; (5) the four single cells for over 5,000 hours each significant cell deterioration or cell failure. It is concluded that the static feed water electrolysis concept is reliable and due to the inherent simplicity of the passive water feed mechanism coupled with the use of alkaline electrolyte has greater potential for regenerative fuel cell system applications than alternative electrolyzers. A rise in cell voltage occur after 2,000-3,000 hours which was attributed to deflection of the polysulfone end plates due to creepage of the thermoplastic. More end plate support was added, and the performance of the cells was restored to the initial performance level.

  10. Electrolysis-assisted mitigation of reverse solute flux in a three-chamber forward osmosis system.

    Zou, Shiqiang; He, Zhen

    2017-05-15

    Forward osmosis (FO) has been widely studied for desalination or water recovery from wastewater, and one of its key challenges for practical applications is reverse solute flux (RSF). RSF can cause loss of draw solutes, salinity build-up and undesired contamination at the feed side. In this study, in-situ electrolysis was employed to mitigate RSF in a three-chamber FO system ("e-FO") with Na 2 SO 4 as a draw solute and deionized (DI) water as a feed. Operation parameters including applied voltage, membrane orientation and initial draw concentrations were systematically investigated to optimize the e-FO performance and reduce RSF. Applying a voltage of 1.5 V achieved a RSF of 6.78 ± 0.55 mmol m -2  h -1 and a specific RSF of 0.138 ± 0.011 g L -1 in the FO mode and with 1 M Na 2 SO 4 as the draw, rendering ∼57% reduction of solute leakage compared to the control without the applied voltage. The reduced RSF should be attributed to constrained ion migration induced by the coactions of electric dragging force (≥1.5 V) and high solute rejection of the FO membrane. Reducing the intensity of the solution recirculation from 60 to 10 mL min -1 significantly reduced specific energy consumption of the e-FO system from 0.693 ± 0.127 to 0.022 ± 0.004 kWh m -3 extracted water or from 1.103 ± 0.059 to 0.044 ± 0.002 kWh kg -1 reduced reversed solute. These results have demonstrated that the electrolysis-assisted RSF mitigation could be an energy-efficient method for controlling RSF towards sustainable FO applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Geophysical bed sediment characterization of the Androscoggin River from the former Chlor-Alkali Facility Superfund Site, Berlin, New Hampshire, to the state border with Maine, August 2009

    Degnan, James R.; Teeple, Andrew; Johnston, Craig M.; Marvin-DiPasquale, Mark C.; Luce, Darryl

    2011-01-01

    The former Chlor-Alkali Facility in Berlin, New Hampshire, was listed on the U.S. Environmental Protection Agency National Priorities List in 2005 as a Superfund site. The Chlor-Alkali Facility lies on the east bank of the Androscoggin River. Elemental mercury currently discharges from that bank into the Androscoggin River. The nature, extent, and the speciation of mercury and the production of methyl mercury contamination in the adjacent Androscoggin River is the subject of continuing investigations. The U.S. Geological Survey, in cooperation with Region I of the U.S. Environmental Protection Agency, used geophysical methods to determine the distribution, thickness, and physical properties of sediments in the Androscoggin River channel at a small area of an upstream reference reach and downstream from the site to the New Hampshire–Maine State border. Separate reaches of the Androscoggin River in the study area were surveyed with surface geophysical methods including ground-penetrating radar and step-frequency electromagnetics. Results were processed to assess sediment characteristics including grain size, electrical conductivity, and pore-water specific conductance. Specific conductance measured during surface- and pore-water sampling was used to help interpret the results of the geophysical surveys. The electrical resistivity of sediment samples was measured in the laboratory with intact pore water for comparison with survey results. In some instances, anthropogenic features and land uses, such as roads and power lines affected the detection of riverbed properties using geophysical methods; when this occurred, the data were removed. Through combining results, detailed riverbed sediment characterizations were made. Results from ground-penetrating radar surveys were used to image and measure the depth to the riverbed, depth to buried riverbeds, riverbed thickness and to interpret material-type variations in terms of relative grain size. Fifty two percent of the

  12. Toxic Byproduct Formation during Electrochemical Treatment of Latrine Wastewater.

    Jasper, Justin T; Yang, Yang; Hoffmann, Michael R

    2017-06-20

    Electrochemical systems are an attractive option for onsite latrine wastewater treatment due to their high efficiency and small footprint. While concerns remain over formation of toxic byproducts during treatment, rigorous studies examining byproduct formation are lacking. Experiments treating authentic latrine wastewater over variable treatment times, current densities, chloride concentrations, and anode materials were conducted to characterize byproducts and identify conditions that minimize their formation. Production of inorganic byproducts (chlorate and perchlorate) and indicator organic byproducts (haloacetic acids and trihalomethanes) during electrolysis dramatically exceeded recommendations for drinking water after one treatment cycle (∼10-30 000 times), raising concerns for contamination of downstream water supplies. Stopping the reaction after ammonium was removed (i.e., the chlorination breakpoint) was a promising method to minimize byproduct formation without compromising disinfection and nutrient removal. Though treatment was accelerated at increased chloride concentrations and current densities, byproduct concentrations remained similar near the breakpoint. On TiO 2 /IrO 2 anodes, haloacetic acids (up to ∼50 μM) and chlorate (up to ∼2 μM) were of most concern. Although boron-doped diamond anodes mineralized haloacetic acids after formation, high production rates of chlorate and perchlorate (up to ∼4 and 25 μM) made them inferior to TiO 2 /IrO 2 anodes in terms of toxic byproduct formation. Organic byproduct formation was similar during chemical chlorination and electrolysis of wastewater, suggesting that organic byproducts are formed by similar pathways in both cases (i.e., reactions with chloramines and free chlorine).

  13. Electrocatalysis in Water Electrolysis with Solid Polymer Electrolyte

    Rasten, Egil

    2001-10-01

    Development and optimization of the electrodes in a water electrolysis system using a polymer membrane as electrolyte have been carried out in this work. A cell voltage of 1.59 V (energy consumption of about 3.8 kWh/Nm{sub 3} H{sub 2}) has been obtained at practical operation conditions of the electrolysis cell (10 kA . m2, 90{sup o}C) using a total noble metal loading of less than 2.4 mg.cm{sub 2} and a Nafion -115 membrane. It is further shown that a cell voltage of less than 1.5 V is possible at the same conditions by combination of the best electrodes obtained in this work. The most important limitation of the electrolysis system using polymer membrane as electrolyte has proven to be the electrical conductivity of the catalysts due to the porous backing/current collector system, which increases the length of the current path and decreases the cross section compared to the apparent one. A careful compromise must therefore be obtained between electrical conductivity and active surface area, which can be tailored by preparation and annealing conditions of the metal oxide catalysts. Anode catalysts of different properties have been developed. The mixed oxide of Ir-Ta (85 mole% Ir) was found to exhibit highest voltage efficiency at a current density of 10 kA.m{sub 2} or below, whereas the mixed oxide of Ir and Ru (60-80 mole% Ir) was found to give the highest voltage efficiency for current densities of above 10 kA.m{sub 2}. Pt on carbon particles, was found to be less suitable as cathode catalyst in water electrolysis. The large carbon particles introduced an unnecessary porosity into the catalytic layer, which resulted in a high ohmic drop. Much better voltage efficiency was obtained by using Pt-black as cathode catalyst, which showed a far better electrical conductivity. Ru-oxide as cathode catalyst in water electrolysis systems using a polymer electrolyte was not found to be of particular interest due to insufficient electrochemical activity and too low

  14. The history of mercury pollution near the Spolana chlor-alkali plant (Neratovice, Czech Republic) as recorded by Scots pine tree rings and other bioindicators

    Navrátil, Tomáš; Šimeček, Martin; Shanley, J. B.; Rohovec, Jan; Hojdová, Maria; Houška, J.

    2017-01-01

    Roč. 586, 15 May (2017), s. 1182-1192 ISSN 0048-9697 R&D Projects: GA ČR(CZ) GA16-14762S Institutional support: RVO:67985831 Keywords : point source * Hg emissions * dendrochemistry * bioindicators * soil * bark * needles * Pinus sylvestris * electrolysis * caustic soda Subject RIV: DD - Geochemistry OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 4.900, year: 2016

  15. Nitrification in Saline Industrial Wastewater

    Moussa, M.S.

    2004-01-01

    Biological nitrogen removal is widely and successfully applied for municipal wastewater. However, these experiences are not directly applicable to industrial wastewater, due to its specific composition. High salt levels in many industrial wastewaters affect nitrification negatively and improved

  16. Identification of water soluble and particle bound compounds causing sublethal toxic effects. A field study on sediments affected by a chlor-alkali industry

    Bosch, Carme; Olivares, Alba; Faria, Melissa; Navas, Jose M.; Olmo, Ivan del; Grimalt, Joan O.; Pina, Benjamin; Barata, Carlos

    2009-01-01

    A combination of cost effective sublethal Daphnia magna feeding tests, yeast- and cell culture-based bioassays and Toxicity Identification Evaluation (TIE) procedures was used to characterize toxic compounds within sediments collected in a river area under the influence of the effluents from a chlor-alkali industry (Ebro River, NE Spain). Tests were designed to measure and identify toxic compounds in the particulate and filtered water fractions of sediment elutriates. The combined use of bioassays responding to elutriates and dioxin-like compounds evidenced the existence of three major groups of hazardous contaminants in the most contaminated site: (A) metals such as cadmium and mercury bound to sediment fine particles that could be easily resuspended and moved downstream, (B) soluble compounds (presumably, lye) able to alkalinize water to toxic levels, and (C) organochlorine compounds with high dioxin-like activity. These results provided evidence that elutriate D. magna feeding responses can be used as surrogate assays for more tedious chronic whole sediment tests, and that the incorporation of such tests in sediment TIE procedures may improve the ability to identify the toxicity of particle-bound and water-soluble contaminants in sediments.

  17. Wastewater Industrial Contributors

    Iowa State University GIS Support and Research Facility — Industrial contributors to municipal wastewater treatment facilities in Iowa for the National Pollutant Discharge Elimination System (NPDES) program.

  18. Wastewater Characteristics, Treatment and Disposal

    Von Sperling, Marcos

    2007-01-01

    "Wastewater Characteristics, Treatment and Disposal is the first volume in the series Biological Wastewater Treatment, presenting an integrated view of water quality and wastewater treatment. The book covers the following topics: wastewater characteristics (flow and major constituents) impact of wastewater discharges to rivers and lakes overview of wastewater treatment systems complementary items in planning studies. This book, with its clear and practical approach, lays the foundations f...

  19. Optimization of electrocoagulation process to treat grey wastewater in batch mode using response surface methodology.

    Karichappan, Thirugnanasambandham; Venkatachalam, Sivakumar; Jeganathan, Prakash Maran

    2014-01-10

    Discharge of grey wastewater into the ecological system causes the negative impact effect on receiving water bodies. In this present study, electrocoagulation process (EC) was investigated to treat grey wastewater under different operating conditions such as initial pH (4-8), current density (10-30 mA/cm2), electrode distance (4-6 cm) and electrolysis time (5-25 min) by using stainless steel (SS) anode in batch mode. Four factors with five levels Box-Behnken response surface design (BBD) was employed to optimize and investigate the effect of process variables on the responses such as total solids (TS), chemical oxygen demand (COD) and fecal coliform (FC) removal. The process variables showed significant effect on the electrocoagulation treatment process. The results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial models were developed in order to study the electrocoagulation process statistically. The optimal operating conditions were found to be: initial pH of 7, current density of 20 mA/cm2, electrode distance of 5 cm and electrolysis time of 20 min. These results indicated that EC process can be scale up in large scale level to treat grey wastewater with high removal efficiency of TS, COD and FC.

  20. Optimization of electrocoagulation process to treat grey wastewater in batch mode using response surface methodology

    2014-01-01

    Background Discharge of grey wastewater into the ecological system causes the negative impact effect on receiving water bodies. Methods In this present study, electrocoagulation process (EC) was investigated to treat grey wastewater under different operating conditions such as initial pH (4–8), current density (10–30 mA/cm2), electrode distance (4–6 cm) and electrolysis time (5–25 min) by using stainless steel (SS) anode in batch mode. Four factors with five levels Box-Behnken response surface design (BBD) was employed to optimize and investigate the effect of process variables on the responses such as total solids (TS), chemical oxygen demand (COD) and fecal coliform (FC) removal. Results The process variables showed significant effect on the electrocoagulation treatment process. The results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial models were developed in order to study the electrocoagulation process statistically. The optimal operating conditions were found to be: initial pH of 7, current density of 20 mA/cm2, electrode distance of 5 cm and electrolysis time of 20 min. Conclusion These results indicated that EC process can be scale up in large scale level to treat grey wastewater with high removal efficiency of TS, COD and FC. PMID:24410752

  1. Indirect Electrochemical Oxidation with Multi Carbon Electrodes for Restaurant Wastewater Treatment

    I Dewa Ketut Sastrawidana

    2018-01-01

    Full Text Available The removal of organic matter from the restaurant wastewater was investigated using the electrochemical oxida-tion method with multi carbon electrodes in a parallel construction. The degradation process was monitored by the measurement of COD concentration as a function of electrolysis time. The effectof operating parameter conditions on COD removal were investigated including initial pH, distance between electrodes, and the applied voltage difference.The results showed that the treatment of restaurant wastewater containing 2 g/L chloride ion using the electrochemical oxidation technique at the operation conditions characterized by: pH 5, distance between electrode of 10 cm and applied voltage of 12 V, enabled to obtained COD removal of 92.84% within 90 min electrolysis time. It is can be concluded that the indirect electrochemical oxidation method with multi carbon electrodes can be used effectivelyas an alternative technology for reducing COD and may be potentially applied for removal organic pollutants from wastewater at the industrial scale.

  2. The development and application of solid polymer electrolysis enrichment device of tritium in water

    Wen Xuelian; Yang Hailan Wu Bin; Yang Huaiyuan

    2003-01-01

    This paper briefly describes the working principle of solid polymer electrolysis enrichment device of tritium in water, presents experiments and works in development of SPE tritium automatic electrolysis enrichment device by CIRP, with which the water samples had been processed for TRIC2000, and the measurement results are satisfied

  3. Electrolysis of Water in the Secondary School Science Laboratory with Inexpensive Microfluidics

    Davis, T. A.; Athey, S. L.; Vandevender, M. L.; Crihfield, C. L.; Kolanko, C. C. E.; Shao, S.; Ellington, M. C. G.; Dicks, J. K.; Carver, J. S.; Holland, L. A.

    2015-01-01

    This activity allows students to visualize the electrolysis of water in a microfluidic device in under 1 min. Instructional materials are provided to demonstrate how the activity meets West Virginia content standards and objectives. Electrolysis of water is a standard chemistry experiment, but the typical laboratory apparatus (e.g., Hoffman cell)…

  4. Performance of single chamber biocatalyzed electrolysis with different types of ion exchange membranes

    Rozendal, R.A.; Hamelers, H.V.M.; Molenkamp, R.J.; Buisman, C.J.N.

    2007-01-01

    In this paper hydrogen production through biocatalyzed electrolysis was studied for the first time in a single chamber configuration. Single chamber biocatalyzed electrolysis was tested in two configurations: (i) with a cation exchange membrane (CEM) and (ii) with an anion exchange membrane (AEM).

  5. Microbial Electrolysis Cells for High Yield Hydrogen Gas Production from Organic Matter

    Logan, B.E.; Call, D.; Cheng, S.; Hamelers, H.V.M.; Sleutels, T.H.J.A.; Jeremiasse, A.W.; Rozendal, R.A.

    2008-01-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (>0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few

  6. Efficiency of tritium measurement in the environmental water by electrolysis enrichment

    Koganezawa, T.; Iida, T. [Nagoya Univ., Graduate School of Engineering, Nagoya, Aichi (Japan); Sakuma, Y.; Yamanishi, H. [National Inst. for Fusion Science, Toki, Gifu (Japan); Ogata, Y. [Nagoya Univ., School of Health Sciences, Nagoya, Aichi (Japan); Tsuji, N. [Japan Air-conditioning Service Co. and Ltd., Nagoya, Aichi (Japan); Kakiuchi, M. [Gakushuin Univ., Faculty of Science, Tokyo (Japan); Satake, H. [Toyama Univ., Faculty of Science, Toyama (Japan)

    2002-06-01

    Now tritium concentration in the environmental water is 0.5-2 Bq{center_dot}L{sup -1} in Japan. Tritium concentration cannot be measured accurately by liquid scintillation method, because the minimum detectable limits of liquid scintillation method is 0.5 Bq{center_dot}L{sup -1}. Therefore, one needs to enrich tritium concentration in the environmental water. Although the most popular method for tritium enrichment is electrolysis, the electrolysis takes much time and labor for distilling sample water at before and after the electrolysis. The purpose of this study is to investigate the possibility of more convenient method for tritium measurement. The method substitutes filtration for distillation at before electrolysis and omits distillation at after electrolysis. The method enables by using the electrolysis with solid polymer electrode. We performed two kinds of experiment to confirm the possibility of the method. First, impurities eluted from electrolysis installation with ultra pure water as sample was measured. Some impurities were eluted into the sample, but they brought noneffective quenching. Secondly, we applied new method to the environmental waters. Substituting for distillation, two filtration, 0.1 {mu}m filtration and reverse osmosis method, were investigated. Impurities in the samples by the filtrations were somewhat higher than that by the distillation, they brought noneffective quenching. We, however, observed distemper of the electrolysis happened by electrolysing filtered sample. Distillation is substituted filtration at before enrichment and omitted at after enrichment, leaving the influence of quenching out of consideration. (author)

  7. Efficiency of tritium measurement in the environmental water by electrolysis enrichment

    Koganezawa, T.; Iida, T.; Sakuma, Y.; Yamanishi, H.; Ogata, Y.; Tsuji, N.; Kakiuchi, M.; Satake, H.

    2002-01-01

    Now tritium concentration in the environmental water is 0.5-2 Bq·L -1 in Japan. Tritium concentration cannot be measured accurately by liquid scintillation method, because the minimum detectable limits of liquid scintillation method is 0.5 Bq·L -1 . Therefore, one needs to enrich tritium concentration in the environmental water. Although the most popular method for tritium enrichment is electrolysis, the electrolysis takes much time and labor for distilling sample water at before and after the electrolysis. The purpose of this study is to investigate the possibility of more convenient method for tritium measurement. The method substitutes filtration for distillation at before electrolysis and omits distillation at after electrolysis. The method enables by using the electrolysis with solid polymer electrode. We performed two kinds of experiment to confirm the possibility of the method. First, impurities eluted from electrolysis installation with ultra pure water as sample was measured. Some impurities were eluted into the sample, but they brought noneffective quenching. Secondly, we applied new method to the environmental waters. Substituting for distillation, two filtration, 0.1 μm filtration and reverse osmosis method, were investigated. Impurities in the samples by the filtrations were somewhat higher than that by the distillation, they brought noneffective quenching. We, however, observed distemper of the electrolysis happened by electrolysing filtered sample. Distillation is substituted filtration at before enrichment and omitted at after enrichment, leaving the influence of quenching out of consideration. (author)

  8. Polymer Electrolyte Membranes for Water Photo-Electrolysis

    Aricò, Antonino S.; Girolamo, Mariarita; Siracusano, Stefania; Sebastian, David; Baglio, Vincenzo; Schuster, Michael

    2017-01-01

    Water-fed photo-electrolysis cells equipped with perfluorosulfonic acid (Nafion® 115) and quaternary ammonium-based (Fumatech® FAA3) ion exchange membranes as separator for hydrogen and oxygen evolution reactions were investigated. Protonic or anionic ionomer dispersions were deposited on the electrodes to extend the interface with the electrolyte. The photo-anode consisted of a large band-gap Ti-oxide semiconductor. The effect of membrane characteristics on the photo-electrochemical conversion of solar energy was investigated for photo-voltage-driven electrolysis cells. Photo-electrolysis cells were also studied for operation under electrical bias-assisted mode. The pH of the membrane/ionomer had a paramount effect on the photo-electrolytic conversion. The anionic membrane showed enhanced performance compared to the Nafion®-based cell when just TiO2 anatase was used as photo-anode. This was associated with better oxygen evolution kinetics in alkaline conditions compared to acidic environment. However, oxygen evolution kinetics in acidic conditions were significantly enhanced by using a Ti sub-oxide as surface promoter in order to facilitate the adsorption of OH species as precursors of oxygen evolution. However, the same surface promoter appeared to inhibit oxygen evolution in an alkaline environment probably as a consequence of the strong adsorption of OH species on the surface under such conditions. These results show that a proper combination of photo-anode and polymer electrolyte membrane is essential to maximize photo-electrolytic conversion. PMID:28468242

  9. Degradation of imidazolium-based ionic liquids in aqueous solution using plasma electrolysis

    Gao, J.; Chen, L.; He, Y.Y.; Yan, Z.C., E-mail: zcyan@scut.edu.cn; Zheng, X.J.

    2014-01-30

    Highlights: • More than 95% of imidazolium-based ILs was degraded within 120 min by means of PE. • The removal efficiency decreased as the order [Cl]{sup −} > [Br]{sup −} > [Ac]{sup −} ≈ [BF{sub 4}]{sup −}. • [C{sub 2}mim]Cl was the most stable compared to [C{sub 4}mim]Cl and [C{sub 6}mim]Cl. • The initial concentration of ILs was found to affect the degradation efficiency. • The imidazole ring was oxidized and then broken to form small molecular compounds. -- Abstract: A novel method of degrading imidazolium-based ionic liquids (ILs) in wastewater using plasma electrolysis (PE) was proposed. The advantage of the PE method was that the ILs acted as both pollutant and electrolyte in the system. Results indicated that ILs with initial concentrations of 1.0–4.0 g/100 mL readily decomposed under an applied voltage of 600 V within 120 min. The anion and alkyl chain lengths of the ILs, discharge time, and post-treatment time were also found to be significant, and the degradation could be described by pseudo-first-order kinetics. Moreover, the energy efficiency of PE for degradation was calculated. The energy yield was generally higher than 2.0 g/kWh, which is approximately 100 times that of the degradation of methyl orange. The oxygen atom, hydroxyl radicals, and hydrogen peroxide produced by PE were important in the oxidation and cleavage of the ILs, and the degradation pathway of the imidazolium-based ILs was investigated using IC, FT-IR, NMR, and GC–MS techniques.

  10. A method for high throughput bioelectrochemical research based on small scale microbial electrolysis cells

    Call, Douglas F.

    2011-07-01

    There is great interest in studying exoelectrogenic microorganisms, but existing methods can require expensive electrochemical equipment and specialized reactors. We developed a simple system for conducting high throughput bioelectrochemical research using multiple inexpensive microbial electrolysis cells (MECs) built with commercially available materials and operated using a single power source. MECs were small crimp top serum bottles (5mL) with a graphite plate anode (92m 2/m 3) and a cathode of stainless steel (SS) mesh (86m 2/m 3), graphite plate, SS wire, or platinum wire. The highest volumetric current density (240A/m 3, applied potential of 0.7V) was obtained using a SS mesh cathode and a wastewater inoculum (acetate electron donor). Parallel operated MECs (single power source) did not lead to differences in performance compared to non-parallel operated MECs, which can allow for high throughput reactor operation (>1000 reactors) using a single power supply. The utility of this method for cultivating exoelectrogenic microorganisms was demonstrated through comparison of buffer effects on pure (Geobacter sulfurreducens and Geobacter metallireducens) and mixed cultures. Mixed cultures produced current densities equal to or higher than pure cultures in the different media, and current densities for all cultures were higher using a 50mM phosphate buffer than a 30mM bicarbonate buffer. Only the mixed culture was capable of sustained current generation with a 200mM phosphate buffer. These results demonstrate the usefulness of this inexpensive method for conducting in-depth examinations of pure and mixed exoelectrogenic cultures. © 2011 Elsevier B.V.

  11. Alkaline membrane water electrolysis with non-noble catalysts

    Kraglund, Mikkel Rykær

    at 1.7 V and 2800 mA cm-2 at 2.0 V. Electrochemical impedance spectroscopy data showed a 6-fold reduction in ohmic cell resistance compared to conventional materials. Albeit good performance, ex-situ characterization and durability tests showed that polymer backbone and membrane stability remained......As renewable energy sources reach higher grid penetration, large scale energy storage solutions are becoming increasingly important. Hydrogen produced with renewable energy by water electrolysis is currently the only option to solve this challenge on a global scale, and green hydrogen is essential...

  12. Elimination of heavy metals from leachates by membrane electrolysis

    Fischer, R. [Technische Universitaet Dresden, Institut fuer Siedlungs- und Industriewasserwirtschaft, Mommsenstrasse 13, 01062 Dresden (Germany); Seidel, H. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Bioremediation, Permoserstrasse 15, D-04318 Leipzig (Germany); Rahner, D. [Technische Universitaet Dresden, Institut fuer Physikalische Chemie und Eektrochemie, Mommsenstrasse 13, D-01062 Dresden (Germany); Morgenstern, P. [UFZ-Umweltforschungszentrum Leipzig-Halle GmbH, Department Analytik, Permoserstrasse 15, D-04318 Leipzig (Germany); Loeser, C. [Technische Universitaet Dresden, Institut fuer Lebensmittel- und Bioverfahrenstechnik, Bergstrasse 120, D-01062 Dresden (Germany)

    2004-10-01

    The elimination of heavy metals from bioleaching process waters (leachates) by electrolysis was studied in the anode and cathode region of a membrane electrolysis cell at current densities of 5-20 mA/cm{sup 2} using various electrode materials. The leaching waters containing a wide range of dissolved heavy metals, were high in sulfate, and had pH values of approx. 3. In preliminary tests using a rotating disc electrode the current density-potential curve (CPK) was recorded at a rotation velocity of 0, 1000 and 2000 rpm and a scan rate of 10 mV/s in order to collect information on the influence of transport processes on the electrochemical processes taking place at the electrodes. The electrochemical deposition-dissolution processes at the cathode are strongly dependent on the hydrodynamics. Detailed examination of the anodic oxidation of dissolved Mn(II) indicated that the manganese dioxide which formed adhered well to the electrode surface but in the cathodic return run it was again reduced. Electrode pairs of high-grade steel, lead and coal as well as material combinations were used to investigate heavy metal elimination in a membrane electrolysis cell. Using high-grade steel, lead and carbon electrode pairs, the reduction and deposition of Cu, Zn, Cr, Ni and some Cd in metallic or hydroxide form were observed in an order of 10-40 % in the cathode chamber. The dominant process in the anode chamber was the precipitation of manganese dioxide owing to the oxidation of dissolved Mn(II). Large amounts of heavy metals were co-precipitated by adsorption onto the insoluble MnO{sub 2}. High-grade steel and to some extent lead anodes were dissolved and hence were proven unsuitable as an anode material. These findings were largely confirmed by experiments using combination electrodes of coal and platinized titanium as an anode material and steel as a cathode material.The results indicate that electrochemical metal separation in the membrane electrolysis cell can represent a

  13. Electrolysis: Information and Opportunities for Electric Power Utilities

    Kroposki, B.; Levene, J.; Harrison, K.; Sen, P.K.; Novachek, F.

    2006-09-01

    Recent advancements in hydrogen technologies and renewable energy applications show promise for economical near- to mid-term conversion to a hydrogen-based economy. As the use of hydrogen for the electric utility and transportation sectors of the U.S. economy unfolds, electric power utilities need to understand the potential benefits and impacts. This report provides a historical perspective of hydrogen, discusses the process of electrolysis for hydrogen production (especially from solar and wind technologies), and describes the opportunities for electric power utilities.

  14. Search for neutron emission during the electrolysis of heavy water

    Coelho, P.R.P.; Saxena, R.N.; Morato, S.P.; Goldman, I.D.; Pinho, A.G. de; Nascimento, I.C.

    1990-03-01

    A liquid scintillator detector NE 213 with pulse shape discrimination technique was used to observe neutrons during the electrolysis of heavy water with a palladium cathode. From the measured fore and background couting rates, a neutron emission rate of (8.2 ± 2.9) x 10 -3 n/(sec.g.) Pd was determined implying (2.9 ± 1.0) x 10 -24 fusions / [(dd pair).sec.] as compared to ≅ 10 -23 fusion/ [(dd pair).sec.] reported by Jones et al. using titanium electrode. (author) [pt

  15. Iron migration from the anode surface in alumina electrolysis

    Zhuravleva, Elena N.; Drozdova, Tatiana N.; Ponomareva, Svetlana V. [Siberian Federal University, Krasnoyarsk, 660041 (Russian Federation); Kirik, Sergei D., E-mail: kiriksd@yandex.ru [Siberian Federal University, Krasnoyarsk, 660041 (Russian Federation); Institute of Chemistry and Chemical Technology SB RAS, Krasnoyarsk, 660036 (Russian Federation)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Corrosion destruction of two-component iron-based alloys in high-temperature aluminum electrolysis in the cryolite alumina melt has been studied. Black-Right-Pointing-Pointer It was found that at the first stage oxidative polarization of iron atoms on the anode surface into Fe{sup 2+} takes place. Black-Right-Pointing-Pointer Fe{sup 2+} interacts with cryolite melt producing FeF{sub 2}. Black-Right-Pointing-Pointer FeF{sub 2} gives oxides FeAl{sub 2}O{sub 4}, Fe{sub 3}O{sub 4}, Fe{sub 2}O{sub 3}. Black-Right-Pointing-Pointer The participation of oxygen in the corrosion has not been observed. - Abstract: Corrosion destruction of two-component iron-based alloys used as an anode in high-temperature alumina electrolysis in the melt of NaF/KF/AlF{sub 3} electrolyte has been considered. Ni, Si, Cu, Cr, Mn, Al, Ti in the amount of up to 10% have been tested as the dopants to an anode alloys. The composition of the corrosion products has been studied using X-ray diffraction, scanning electron microscopy and electron microprobe analysis. It has been established that the anode corrosion is induced by a surface electrochemical polarization and iron atom oxidation. Iron ions come into an exchange interaction with the fluoride components of the melted electrolyte, producing FeF{sub 2}. The last interacts with oxyfluoride species transforming into the oxide forms: FeAl{sub 2}O{sub 4}, Fe{sub 3}O{sub 4}, Fe{sub 2}O{sub 3}. Due to the low solubility, the iron oxides are accumulated in the near-electrode sheath. The only small part of iron from anode migrates to cathode that makes an production of high purity aluminum of a real task. The alloy dopants are also subjected to corrosion in accordance with electromotive series resulting corrosion tunnels on the anode surface. The oxides are final compounds which collect in the same area. The corrosion products form an anode shell which is electronic conductor at electrolysis temperature. The

  16. Intermediate Temperature Steam Electrolysis with Phosphate-Based Electrolytes

    Prag, Carsten Brorson

    as the technological issues and challenges faced. A setup suitable for intermediate temperature electrolysis has been constructed in order to accommodate testing in the IT region. This included the evaluation of multiple generations of components such as end plates and flow plates. Chemical vapour deposition...... treatment step of the synthesis. It was found that initial heating of the synthesis precursors to 270 _C gave a high quality sample in a reproducible fashion. Investigations of two additional novel phosphates was attempted. These were phosphoric acid treated Nb5P7O30 and a mixture of Bi2P4O13, BiPO4 and 2...

  17. Production of Oxygen from Lunar Regolith by Molten Oxide Electrolysis

    Curreri, Peter A.

    2009-01-01

    This paper describes the use of the molten oxide electrolysis (MOE) process for the extraction of oxygen for life support and propellant, and silicon and metallic elements for use in fabrication on the Moon. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis is ideal for extraction, since the electron is the only practical reducing agent. MOE has several advantages over other extraction methods. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. Alternatively, MOE requires no import of consumable reagents (e.g. fluorine and carbon) as other processes do, and does not rely on interfacing multiple processes to obtain refined products. Electrolytic processing has the advantage of selectivity of reaction in the presence of a multi-component feed. Products from lunar regolith can be extracted in sequence according to the stabilities of their oxides as expressed by the values of the free energy of oxide formation (e.g. chromium, manganese, Fe, Si, Ti, Al, magnesium, and calcium). Previous work has demonstrated the viability of producing Fe and oxygen from oxide mixtures similar in composition to lunar regolith by molten oxide electrolysis (electrowinning), also called magma electrolysis having shown electrolytic extraction of Si from regolith simulant. This paper describes recent advances in demonstrating the MOE process by a joint project with participation by NASA KSC and

  18. Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water

    Guoo-Shyng Wang Hsu

    2017-10-01

    Full Text Available Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW. DOW was electrolyzed in a glass electrolyzing cell equipped with platinum–plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be.

  19. Effects of electrolysis time and electric potential on chlorine generation of electrolyzed deep ocean water.

    Hsu, Guoo-Shyng Wang; Lu, Yi-Fa; Hsu, Shun-Yao

    2017-10-01

    Electrolyzed water is a sustainable disinfectant, which can comply with food safety regulations and is environmentally friendly. A two-factor central composite design was adopted for studying the effects of electrolysis time and electric potential on the chlorine generation efficiency of electrolyzed deep ocean water (DOW). DOW was electrolyzed in a glass electrolyzing cell equipped with platinum-plated titanium anode and cathode. The results showed that chlorine concentration reached maximal level in the batch process. Prolonged electrolysis reduced chlorine concentration in the electrolyte and was detrimental to electrolysis efficiency, especially under high electric potential conditions. Therefore, the optimal choice of electrolysis time depends on the electrolyzable chloride in DOW and cell potential adopted for electrolysis. The higher the electric potential, the faster the chlorine level reaches its maximum, but the lower the electric efficiency will be. Copyright © 2016. Published by Elsevier B.V.

  20. Characteristics of grey wastewater

    Eriksson, Eva; Auffarth, Karina Pipaluk Solvejg; Henze, Mogens

    2002-01-01

    The composition of grey wastewater depends on sources and installations from where the water is drawn, e.g. kitchen, bathroom or laundry. The chemical compounds present originate from household chemicals, cooking, washing and the piping. In general grey wastewater contains lower levels of organic...

  1. New Electrolytes for CO2 Electrolysis Cells

    Mollerup, Pia Lolk

    The aim of this thesis has been to explore the potential of aqueous immobilized K2CO3 as a possible electrolyte for co-electrolysis of CO2 and water at approx. 200 °C. This has been done by exploring the properties of pure K2CO3 (aq) and immobilized K2CO3 (aq) as well as the properties...... was observed for 10 wt% K2CO3 immobilized in TiO2 when changing the atmosphere from N2 to CO2. K2CO3 (aq) immobilized in TiO2 shows good promise as a potential electrolyte for co-electrolysis of CO2 and water at 200 °C....... in a 10 wt% K2CO3 (aq) solution are K+ and HCO3-. The water partial pressure as well as the amount of water vapour at different temperatures, pressures and K2CO3 (aq) concentrations was also calculated using FactSage. K2CO3 (aq) was immobilized in both SrTiO3 and TiO2. It was found that a loss...

  2. Static Feed Water Electrolysis Subsystem Testing and Component Development

    Koszenski, E. P.; Schubert, F. H.; Burke, K. A.

    1983-01-01

    A program was carried out to develop and test advanced electrochemical cells/modules and critical electromechanical components for a static feed (alkaline electrolyte) water electrolysis oxygen generation subsystem. The accomplishments were refurbishment of a previously developed subsystem and successful demonstration for a total of 2980 hours of normal operation; achievement of sustained one-person level oxygen generation performance with state-of-the-art cell voltages averaging 1.61 V at 191 ASF for an operating temperature of 128F (equivalent to 1.51V when normalized to 180F); endurance testing and demonstration of reliable performance of the three-fluid pressure controller for 8650 hours; design and development of a fluid control assembly for this subsystem and demonstration of its performance; development and demonstration at the single cell and module levels of a unitized core composite cell that provides expanded differential pressure tolerance capability; fabrication and evaluation of a feed water electrolyte elimination five-cell module; and successful demonstration of an electrolysis module pressurization technique that can be used in place of nitrogen gas during the standby mode of operation to maintain system pressure and differential pressures.

  3. Electrochemical extraction of oxygen using PEM electrolysis technology

    BOULBABA ELADEB

    2012-11-01

    Full Text Available Electrochemical extraction of oxygen from air can be carried out by chemical reduction of oxygen at the cathode and simultaneous oxygen evolution by water anode oxidation. The present investigation deals with the use of an electrolysis cell of PEM technology for this purpose. A dedicated 25 cm2 cell provided with a commercial water electrolysis MEA and titanium grooved plates has been designed for continuous operation at pressures close to the ambient level. The MEA consisted of a Nafion 117 membrane sandwiched between a Pt/C cathode and a non-supported Pt-Ir anode. Oxygen partial consumption in long-term runs was evaluated by analysis of the outlet air by gas chromatography, depending on the cell voltage - or the current density - and the excess in air oxygen fed to the cathode. Runs over more 50 hours indicated the relative stability of the components used for current densities ranging from 0.1 to 0.2 A cm-2 with high efficiency of oxygen reduction. Higher current density could be envisaged with more efficient MEA’s, exhibiting lower overpotentials for oxygen evolution to avoid too significant degradation of the anode material and the membrane. Interpretation of the data has been carried out by calculation of the cathode current efficiency.

  4. HYFIRE: a tokamak-high-temperature electrolysis system

    Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Horn, F.; Isaacs, H.; Lazareth, O.W.; Makowitz, H.; Usher, J.

    1980-01-01

    Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 0 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constituents, H 2 and O 2 , electrical input is required. Fourteen hundred degree steam coupled with 40% power efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

  5. HYFIRE: a tokamak-high-temperature electrolysis system

    Fillo, J.A.; Powell, J.R.; Steinberg, M.; Benenati, R.; Horn, F.; Isaacs, H.; Lazareth, O.W.; Makowitz, H.; Usher, J.

    1980-01-01

    Brookhaven National Laboratory (BNL) is carrying out a comprehensive conceptual design study called HYFIRE of a commercial fusion Tokamak reactor, high-temperature electrolysis system. The study is placing particular emphasis on the adaptability of the STARFIRE power reactor to a synfuel application. The HYFIRE blanket must perform three functions: (a) provide high-temperature (approx. 1400 0 C) process steam at moderate pressures (in the range of 10 to 30 atm) to the high-temperature electrolysis (HTE) units; (b) provide high-temperature (approx. 700 0 to 800 0 C) heat to a thermal power cycle for generation of electricity to the HTE units; and (c) breed enough tritium to sustain the D-T fuel cycle. In addition to thermal energy for the decomposition of steam into its constituents, H 2 and O 2 , electrical input is required. Fourteen hundred degree steam coupled with 40% power cycle efficiency results in a process efficiency (conversion of fusion energy to hydrogen chemical energy) of 50%

  6. Performance of metal compound on thermolysis and electrolysis on sugar industries waste water treatment: COD and color removal with sludge analysis (batch-experiment)

    Sahu, Omprakash

    2017-10-01

    The sugar cane industry is one of the most water demanding industries. Sugar industries consume and generate excess amount of water. The generated water contains organic compounds, which would cause pollution. The aim of this research work is to study the effectiveness of metal compound for treatment of sugar industry waste water by thermolysis and electrolysis process. The result shows ferrous metal catalyst shows 80 and 85 % chemical oxygen demand and color removal at pH 6, optimum mass loading 4 kg/m3, treatment temperature 85 °C and treatment time 9 h. When ferrous material was used as electrode, maximum 81 % chemical oxygen demand and 84 % color removal at pH 6, current density 156 Am-2, treatment time 120 min and anode consumption 0.7 g for 1.5 L wastewater were obtained.

  7. Effects of anodic potential and chloride ion on overall reactivity in electrochemical reactors designed for solar-powered wastewater treatment.

    Cho, Kangwoo; Qu, Yan; Kwon, Daejung; Zhang, Hao; Cid, Clément A; Aryanfar, Asghar; Hoffmann, Michael R

    2014-02-18

    We have investigated electrochemical treatment of real domestic wastewater coupled with simultaneous production of molecular H2 as useful byproduct. The electrolysis cells employ multilayer semiconductor anodes with electroactive bismuth-doped TiO2 functionalities and stainless steel cathodes. DC-powered laboratory-scale electrolysis experiments were performed under static anodic potentials (+2.2 or +3.0 V NHE) using domestic wastewater samples, with added chloride ion in variable concentrations. Greater than 95% reductions in chemical oxygen demand (COD) and ammonium ion were achieved within 6 h. In addition, we experimentally determined a decreasing overall reactivity of reactive chlorine species toward COD with an increasing chloride ion concentration under chlorine radicals (Cl·, Cl2(-)·) generation at +3.0 V NHE. The current efficiency for COD removal was 12% with the lowest specific energy consumption of 96 kWh kgCOD(-1) at the cell voltage of near 4 V in 50 mM chloride. The current efficiency and energy efficiency for H2 generation were calculated to range from 34 to 84% and 14 to 26%, respectively. The hydrogen comprised 35 to 60% by volume of evolved gases. The efficacy of our electrolysis cell was further demonstrated by a 20 L prototype reactor totally powered by a photovoltaic (PV) panel, which was shown to eliminate COD and total coliform bacteria in less than 4 h of treatment.

  8. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China); Lee, Hyung-Sool [Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West Waterloo, Ontario, Canada N2L 3G1 (Canada); Wang, Ai-Jie, E-mail: waj0578@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. Black-Right-Pointing-Pointer Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). Black-Right-Pointing-Pointer PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. Black-Right-Pointing-Pointer The mechanism of UBER for azo dye removal was discussed. - Abstract: Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8 {+-} 1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 g m{sup -3} d{sup -1}) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 g m{sup -3} d{sup -1} (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China.

  9. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

    2012-01-01

    Highlights: ► A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. ► Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). ► PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. ► The mechanism of UBER for azo dye removal was discussed. - Abstract: Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8 ± 1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 g m −3 d −1 ) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 g m −3 d −1 (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China.

  10. Destination of organic pollutants during electrochemical oxidation of biologically-pretreated dye wastewater using boron-doped diamond anode.

    Zhu, Xiuping; Ni, Jinren; Wei, Junjun; Xing, Xuan; Li, Hongna

    2011-05-15

    Electrochemical oxidation of biologically-pretreated dye wastewater was performed in a boron-doped diamond (BDD) anode system. After electrolysis of 12h, the COD was decreased from 532 to 99 mg L(-1) (destination of organic pollutants during electrochemical oxidation process was carefully investigated by molecular weight distribution measurement, resin fractionation, ultraviolet-visible spectroscopy, HPLC and GC-MS analysis, and toxicity test. As results, most organic pollutants were completely removed by electrochemical oxidation and the rest was primarily degraded to simpler compounds (e.g., carboxylic acids and short-chain alkanes) with less toxicity, which demonstrated that electrochemical oxidation of biologically-pretreated dye wastewater with BDD anode was very effective and safe. Especially, the performance of BDD anode system in degradation of large molecular organics such as humic substances makes it very promising in practical applications as an advanced treatment of biologically-pretreated wastewaters. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Destination of organic pollutants during electrochemical oxidation of biologically-pretreated dye wastewater using boron-doped diamond anode

    Zhu, Xiuping; Ni, Jinren; Wei, Junjun; Xing, Xuan; Li, Hongna

    2011-01-01

    Electrochemical oxidation of biologically-pretreated dye wastewater was performed in a boron-doped diamond (BDD) anode system. After electrolysis of 12 h, the COD was decreased from 532 to 99 mg L -1 ( -1 , the National Discharge Standard of China). More importantly, the destination of organic pollutants during electrochemical oxidation process was carefully investigated by molecular weight distribution measurement, resin fractionation, ultraviolet-visible spectroscopy, HPLC and GC-MS analysis, and toxicity test. As results, most organic pollutants were completely removed by electrochemical oxidation and the rest was primarily degraded to simpler compounds (e.g., carboxylic acids and short-chain alkanes) with less toxicity, which demonstrated that electrochemical oxidation of biologically-pretreated dye wastewater with BDD anode was very effective and safe. Especially, the performance of BDD anode system in degradation of large molecular organics such as humic substances makes it very promising in practical applications as an advanced treatment of biologically-pretreated wastewaters.

  12. High-pressure water electrolysis: Electrochemical mitigation of product gas crossover

    Schalenbach, Maximilian; Stolten, Detlef

    2015-01-01

    Highlights: • New technique to reduce gas crossover during water electrolysis • Increase of the efficiency of pressurized water electrolysis • Prevention of safety hazards due to explosive gas mixtures caused by crossover • Experimental realization for a polymer electrolyte membrane electrolyzer • Discussion of electrochemical crossover mitigation for alkaline water electrolysis - Abstract: Hydrogen produced by water electrolysis can be used as an energy carrier storing electricity generated from renewables. During water electrolysis hydrogen can be evolved under pressure at isothermal conditions, enabling highly efficient compression. However, the permeation of hydrogen through the electrolyte increases with operating pressure and leads to efficiency loss and safety hazards. In this study, we report on an innovative concept, where the hydrogen crossover is electrochemically mitigated by an additional electrode between the anode and the cathode of the electrolysis cell. Experimentally, the technique was applied to a proton exchange membrane water electrolyzer operated at a hydrogen pressure that was fifty times larger than the oxygen pressure. Therewith, the hydrogen crossover was reduced and the current efficiency during partial load operation was increased. The concept is also discussed for water electrolysis that is operated at balanced pressures, where the crossover of hydrogen and oxygen is mitigated using two additional electrodes

  13. Oxygen Handling and Cooling Options in High Temperature Electrolysis Plants

    Manohar S. Sohal; J. Stephen Herring

    2008-07-01

    Idaho National Laboratory is working on a project to generate hydrogen by high temperature electrolysis (HTE). In such an HTE system, safety precautions need to be taken to handle high temperature oxygen at ~830°C. This report is aimed at addressing oxygen handling in a HTE plant.. Though oxygen itself is not flammable, most engineering material, including many gases and liquids, will burn in the presence of oxygen under some favorable physicochemical conditions. At present, an absolute set of rules does not exist that can cover all aspects of oxygen system design, material selection, and operating practices to avoid subtle hazards related to oxygen. Because most materials, including metals, will burn in an oxygen-enriched environment, hazards are always present when using oxygen. Most materials will ignite in an oxygen-enriched environment at a temperature lower than that in air, and once ignited, combustion rates are greater in the oxygen-enriched environment. Even many metals, if ignited, burn violently in an oxygen-enriched environment. However, these hazards do not preclude the operations and systems involving oxygen. Oxygen can be safely handled and used if all the materials in a system are not flammable in the end-use environment or if ignition sources are identified and controlled. In fact, the incidence of oxygen system fires is reported to be low with a probability of about one in a million. This report is a practical guideline and tutorial for the safe operation and handling of gaseous oxygen in high temperature electrolysis system. The intent is to provide safe, practical guidance that permits the accomplishment of experimental operations at INL, while being restrictive enough to prevent personnel endangerment and to provide reasonable facility protection. Adequate guidelines are provided to govern various aspects of oxygen handling associated with high temperature electrolysis system to generate hydrogen. The intent here is to present acceptable

  14. Production of Synthetic Fuels by Co-Electrolysis of Steam and Carbon Dioxide

    Ebbesen, Sune; Graves, Christopher R.; Mogensen, Mogens Bjerg

    2009-01-01

    reactions, the equilibrium of the water-gas shift reaction is reached, and moreover, CO is produced via the water-gas shift reaction. The degradation observed when performing co-electrolysis in these SOCs occurs mainly at the Ni/YSZ cathode and may be a consequence of impurities in the gas stream, adsorbing......Co-electrolysis of H2O and CO2 was studied in solid oxide cells (SOCs) supported by nickel-/yittria-stabilized zirconia (Ni/YSZ) electrode. Polarization characterization indicates that electrochemical reduction of both CO2 and H2O occurs during co-electrolysis. In parallel with the electrochemical...

  15. Dairy wastewater treatment

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... treatment processes to treat dairy wastewater such as activated sludge system .... Gas chromatograph. (Perkin Elmer, Auto system XL), equipped with thermal conductivity ..... Enzymatic hydrolysis of molasses. Bioresour. Tech.

  16. Wastewater Treatment Facilities

    Iowa State University GIS Support and Research Facility — Individual permits for municipal, industrial, and semi-public wastewater treatment facilities in Iowa for the National Pollutant Discharge Elimination System (NPDES)...

  17. Recycling phosphorus from wastewater

    Lemming, Camilla Kjærulff

    wastewater-derived products, and to relate this to the availability from other P-containing waste products and mineral P fertiliser. This included aspects of development over time and soil accumulation, as well as effects of soil pH and the spatial distribution in soil. The P sources applied in this PhD work...... reserves. Wastewater represents the largest urban flow of P in waste. Hence, knowledge about plant P availability of products from the wastewater treatment system, and also comparison to other waste P sources and mineral P is essential to obtain an efficient recycling and to prioritise between different P...... recycling options. The work of this PhD focused on the plant P availability of sewage sludge, a P-rich residue from wastewater treatment which is commonly applied to agricultural soil in Denmark. The overall objective of the PhD work was to evaluate the plant availability of P in sewage sludge and other...

  18. Wastewater Treatment Plants

    Iowa State University GIS Support and Research Facility — The actual treatment areas for municipal, industrial, and semi-public wastewater treatment facilities in Iowa for the National Pollutant Discharge Elimination System...

  19. Electrochemical oxidation of textile industry wastewater by graphite electrodes.

    Bhatnagar, Rajendra; Joshi, Himanshu; Mall, Indra D; Srivastava, Vimal C

    2014-01-01

    In the present article, studies have been performed on the electrochemical (EC) oxidation of actual textile industry wastewater by graphite electrodes. Multi-response optimization of four independent parameters namely initial pH (pHo): 4-10, current density (j): 27.78-138.89 A/m(2), NaCl concentration (w): 0-2 g/L and electrolysis time (t): 10-130 min have been performed using Box-Behnken (BB) experimental design. It was aimed to simultaneously maximize the chemical oxygen demand (COD) and color removal efficiencies and minimize specific energy consumption using desirability function approach. Pareto analysis of variance (ANOVA) showed a high coefficient of determination value for COD (R(2) = 0.8418), color (R(2) = 0.7010) and specific energy (R(2) = 0.9125) between the experimental values and the predicted values by a second-order regression model. Maximum COD and color removal and minimum specific energy consumed was 90.78%, 96.27% and 23.58 kWh/kg COD removed, respectively, were observed at optimum conditions. The wastewater, sludge and scum obtained after treatment at optimum condition have been characterized by various techniques. UV-visible study showed that all azo bonds of the dyes present in the wastewater were totally broken and most of the aromatic rings were mineralized during EC oxidation with graphite electrode. Carbon balance showed that out of the total carbon eroded from the graphite electrodes, 27-29.2% goes to the scum, 71.1-73.3% goes into the sludge and rest goes to the treated wastewater. Thermogravimetric analysis showed that the generated sludge and scum can be dried and used as a fuel in the boilers/incinerators.

  20. Degradation efficiency and mechanism of azo dye RR2 by a novel ozone aerated internal micro-electrolysis filter.

    Zhang, Xian-Bing; Dong, Wen-Yi; Sun, Fei-Yun; Yang, Wei; Dong, Jiao

    2014-07-15

    A newly designed ozone aerated internal micro-electrolysis filter (OIEF) was developed to investigate its degradation efficiencies and correlated reaction mechanisms of RR2 dye. Complete decolorization and 82% TOC removal efficiency were stably achieved in OIEF process. Based on the comprehensive experimental results, an empirical equation was proposed to illustrate the effects of initial dye concentration and ozone dosage rate on color removal. The results indicated that OIEF process could be operated at wide pH range without significant treatment efficiencies change, while the optimum pH for RR2 dye degradation was 9.0. There were 15, 8 and 6 kinds of identified intermediates during ozonation, IE and OIEF treatment processes, respectively. Less identified intermediates and their lower concentrations in OIEF may attribute to its rather excellent mineralization performance. It was found that ozonation, Fe(2+)/Fe(3+) catalyzed ozonation, the redox reactions of electro-reduction and electro-oxidation are the most important mechanisms in OIEF process. The catalytic effect of Fe(2+)/Fe(3+) would induce mutual conversion between dissolved Fe(2+) and Fe(3+), and then decrease the dissolution rate of ZVI. The excellent treatment performance proved that the OIEF process is one promising technology applied for reactive azo dyes and other refractory wastewater treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Effect of the anode feeding composition on the performance of a continuous-flow methane-producing microbial electrolysis cell.

    Zeppilli, Marco; Villano, Marianna; Aulenta, Federico; Lampis, Silvia; Vallini, Giovanni; Majone, Mauro

    2015-05-01

    A methane-producing microbial electrolysis cell (MEC) was continuously fed at the anode with a synthetic solution of soluble organic compounds simulating the composition of the soluble fraction of a municipal wastewater. The MEC performance was assessed at different anode potentials in terms of chemical oxygen demand (COD) removal efficiency, methane production, and energy efficiency. As a main result, about 72-80% of the removed substrate was converted into current at the anode, and about 84-86% of the current was converted into methane at the cathode. Moreover, even though both COD removed and methane production slightly decreased as the applied anode potential decreased, the energy efficiency (i.e., the energy recovered as methane with respect to the energy input into the system) increased from 54 to 63%. Denaturing gradient gel electrophoresis (DGGE) analyses revealed a high diversity in the anodic bacterial community with the presence of both fermentative (Proteiniphilum acetatigenes and Petrimonas sulphurifila) and aerobic (Rhodococcus qingshengii) microorganisms, whereas only two microorganisms (Methanobrevibacter arboriphilus and Methanosarcina mazei), both assignable to methanogens, were observed in the cathodic community.

  2. Microbial Reverse-Electrodialysis Electrolysis and Chemical-Production Cell for H2 Production and CO2 Sequestration.

    Zhu, Xiuping; Hatzell, Marta C; Logan, Bruce E

    2014-01-01

    Natural mineral carbonation can be accelerated using acid and alkali solutions to enhance atmospheric CO2 sequestration, but the production of these solutions needs to be carbon-neutral. A microbial reverse-electrodialysis electrolysis and chemical-production cell (MRECC) was developed to produce these solutions and H2 gas using only renewable energy sources (organic matter and salinity gradient). Using acetate (0.82 g/L) as a fuel for microorganisms to generate electricity in the anode chamber (liquid volume of 28 mL), 0.45 mmol of acid and 1.09 mmol of alkali were produced at production efficiencies of 35% and 86%, respectively, along with 10 mL of H2 gas. Serpentine dissolution was enhanced 17-87-fold using the acid solution, with approximately 9 mL of CO2 absorbed and 4 mg of CO2 fixed as magnesium or calcium carbonates. The operational costs, based on mineral digging and grinding, and water pumping, were estimated to be only $25/metric ton of CO2 fixed as insoluble carbonates. Considering the additional economic benefits of H2 generation and possible wastewater treatment, this method may be a cost-effective and environmentally friendly method for CO2 sequestration.

  3. Microbial Reverse-Electrodialysis Electrolysis and Chemical-Production Cell for H2 Production and CO2 Sequestration.

    Zhu, Xiuping

    2014-03-24

    Natural mineral carbonation can be accelerated using acid and alkali solutions to enhance atmospheric CO2 sequestration, but the production of these solutions needs to be carbon-neutral. A microbial reverse-electrodialysis electrolysis and chemical-production cell (MRECC) was developed to produce these solutions and H2 gas using only renewable energy sources (organic matter and salinity gradient). Using acetate (0.82 g/L) as a fuel for microorganisms to generate electricity in the anode chamber (liquid volume of 28 mL), 0.45 mmol of acid and 1.09 mmol of alkali were produced at production efficiencies of 35% and 86%, respectively, along with 10 mL of H2 gas. Serpentine dissolution was enhanced 17-87-fold using the acid solution, with approximately 9 mL of CO2 absorbed and 4 mg of CO2 fixed as magnesium or calcium carbonates. The operational costs, based on mineral digging and grinding, and water pumping, were estimated to be only $25/metric ton of CO2 fixed as insoluble carbonates. Considering the additional economic benefits of H2 generation and possible wastewater treatment, this method may be a cost-effective and environmentally friendly method for CO2 sequestration.

  4. Two-stage electrolysis to enrich tritium in environmental water

    Shima, Nagayoshi; Muranaka, Takeshi

    2007-01-01

    We present a two-stage electrolyzing procedure to enrich tritium in environmental waters. Tritium is first enriched rapidly through a commercially-available electrolyser with a large 50A current, and then through a newly-designed electrolyser that avoids the memory effect, with a 6A current. Tritium recovery factor obtained by such a two-stage electrolysis was greater than that obtained when using the commercially-available device solely. Water samples collected in 2006 in lakes and along the Pacific coast of Aomori prefecture, Japan, were electrolyzed using the two-stage method. Tritium concentrations in these samples ranged from 0.2 to 0.9 Bq/L and were half or less, that in samples collected at the same sites in 1992. (author)

  5. Impact of low gravity on water electrolysis operation

    Powell, F. T.; Schubert, F. H.; Lee, M. G.

    1989-01-01

    Advanced space missions will require oxygen and hydrogen utilities for several important operations including the following: (1) propulsion; (2) electrical power generation and storage; (3) environmental control and life support; (4) extravehicular activity; (5) in-space manufacturing and (6) in-space science activities. An experiment suited to a Space Shuttle standard middeck payload has been designed for the Static Feed Water Electrolysis technology which has been viewed as being capable of efficient, reliable oxygen and hydrogen generation with few subsystem components. The program included: end use design requirements, phenomena to be studied, Space Shuttle Orbiter experiment constraints, experiment design and data requirements, and test hardware requirements. The objectives are to obtain scientific and engineering data for future research and development and to focus on demonstrating and monitoring for safety of a standard middeck payload.

  6. Advancements in water vapor electrolysis technology. [for Space Station ECLSS

    Chullen, Cinda; Heppner, Dennis B.; Sudar, Martin

    1988-01-01

    The paper describes a technology development program whose goal is to develop water vapor electrolysis (WVE) hardware that can be used selectively as localized topping capability in areas of high metabolic activity without oversizing the central air revitalization system on long-duration manned space missions. The WVE will be used primarily to generate O2 for the crew cabin but also to provide partial humidity control by removing water vapor from the cabin atmosphere. The electrochemically based WVE interfaces with cabin air which is controlled in the following ranges: dry bulb temperature of 292 to 300 K; dew point temperature of 278 to 289 K; relative humidity of 25 to 75 percent; and pressure of 101 + or - 1.4 kPa. Design requirements, construction details, and results for both single-cell and multicell module testing are presented, and the preliminary sizing of a multiperson subsystem is discussed.

  7. An investigation of energy balances in palladium cathode electrolysis experiments

    Longhurst, G. R.; Dolan, T. J.; Henriksen, G. L.

    1990-09-01

    A series of experiments was performed at the Idaho National Engineering Laboratory (INEL) to investigate mechanisms that may contribute to energy flows in electrolysis cells like those of Fleischmann and Pons. Ordinary water (H2O), heavy water (D2O), and a mixture of the two were used in the INEL experiments. Cathodes used include a 51-μm Pd foil and 1-mm diameter extruded wire Pd rods in straight and coiled configurations. Energy balances in these experiments revealed no significant net gain or net loss of energy. Cell overpotential curves were fit well with a Tafel equation, with parameters dependent on electrode configuration, electrolyte composition, and temperature. Water evaporation and interactions of hydrogen isotopes with the Pd cathode were evaluated and found not to be significant to energy balances. No ionizing radiation, tritium production, or other evidence of fusion reactions was observed in the INEL experiments.

  8. Hydrogen Production by Water Electrolysis Via Photovoltaic Panel

    Hydrogen Production by Water Electrolysis Via Photovoltaic Panel

    2016-07-01

    Full Text Available Hydrogen fuel is a good alternative to fossil fuels. It can be produced using a clean energy without contaminated emissions. This work is concerned with experimental study on hydrogen production via solar energy. Photovoltaic module is used to convert solar radiation to electrical energy. The electrical energy is used for electrolysis of water into hydrogen and oxygen by using alkaline water electrolyzer with stainless steel electrodes. A MATLAB computer program is developed to solve a four-parameter-model and predict the characteristics of PV module under Baghdad climate conditions. The hydrogen production system is tested at different NaOH mass concentration of (50,100, 200, 300 gram. The maximum hydrogen production rate is 153.3 ml/min, the efficiency of the system is 20.88% and the total amount of hydrogen produced in one day is 220.752 liter.

  9. A Decade of Solid Oxide Electrolysis Improvements at DTU Energy

    Hauch, Anne; Brodersen, Karen; Chen, Ming

    2017-01-01

    a short review of the R&D work on SOEC single cells conducted at DTU Energy from 2005 to 2015. The SOEC improvements have involved increasing the of the oxygen electrode performance, elimination of impurities in the feed streams, optimization of processing routes, and fuel electrode structure optimization....... All together, these improvements have led to a decrease in long-term degradation rate from ∼40 %/kh to ∼0.4 %/kh for steam electrolysis at -1 A/cm2, while the initial area specific resistance has been decreased from 0.44 Ωcm2 to 0.15 Ωcm2 at -0.5 A/cm2 and 750 °C....

  10. CO2 Fixation by Membrane Separated NaCl Electrolysis

    Park, Hyun Sic; Lee, Ju Sung; Han, Junyoung

    2015-01-01

    for converting CO2 into CaCO3 requires high temperature and high pressure as reaction conditions. This study proposes a method to fixate CaCO3 stably by using relatively less energy than existing methods. After forming NaOH absorbent solution through electrolysis of NaCl in seawater, CaCO3 was precipitated...... crystal product was high-purity calcite. The study shows a successful method for fixating CO2 by reducing carbon dioxide released into the atmosphere while forming high-purity CaCO3.......Atmospheric concentrations of carbon dioxide (CO2), a major cause of global warming, have been rising due to industrial development. Carbon capture and storage (CCS), which is regarded as the most effective way to reduce such atmospheric CO2 concentrations, has several environmental and technical...

  11. Experiment on electrolysis decontamination of stainless steel pipes

    Wang Dongwen; Dou Tianjun; Zhao Yujie

    2004-01-01

    A new electrolytic decontamination method used metal balls as conducting anode was investigated. The influences of current density, solution property and diameter of pipes on efficiency of electrolytic decontamination were examined and the efficiency of this method was compared with that of common electrolytic method under the same experimental conditions. Decontamination of samples of stainless steel pipes contaminated by plutonium was performed. Experimental results indicate that decontamination of stainless steel pipes contaminated by plutonium can be achieved at the optimum conditions of greater than 0.2 A·cm -2 current density, 5% sulfuric acid electrolyte and 5 min electrolysis. This method can be used in the decontamination of a wide variety of decommissioned metal materials. (author)

  12. Durable solid oxide electrolysis cells for hydrogen production

    Sun, Xiufu; Chen, Ming; Hendriksen, Peter Vang

    2014-01-01

    production is required for promoting commercialization of the SOEC technology. In this work, we report a recent 4400 hours test of a state-of-the-art Ni-YSZ electrode supported SOEC cell. The cell consists of a Ni-YSZ (YSZ: yttria stabilized zirconia) support and active fuel electrode, an YSZ electrolyte...... that except for the first 250 hours fast initial degradation, for the rest of the testing period, the cell showed rather stable performance with an moderate degradation rate of around 25 mV/1000 h. The electrochemical impedance spectra show that both serial resistance and polarization resistance of the cell...... and changing of porosity inside the active layer. The degree of these microstructural changes becomes less and less severe along the hydrogen-steam flow path. The present test results show that this type of cell can be used for early demonstration electrolysis at 1A/cm2. Future work should be focus on reducing...

  13. Application of Response Surface Methodology (RSM) for wastewater of hospital by using electrocoagulation

    Murdani; Jakfar; Ekawati, D.; Nadira, R.; Darmadi

    2018-04-01

    Hospital wastewater is a source of potential environmental contamination. Therefore, the waste water needs to be treated before it is discharged into the landfill. Various research methods have been used to treat hospital wastewater. However, some methods that have been implemented have not achieved the effluent standards for hospitals that have been set by the government. The experiment was conducted by an electrochemical method is electrolysis using aluminum electrodes with independent variable is the voltage, contact time and concentration of electrolytes. The response optimization using response surface with optimum conditions obtained by the contact time of 34.26 min, voltage 12 V, concentration electrolyte 0.38 M can decrease of COD 65.039%. The model recommended by the response surface for the three variables, namely quadratic response.

  14. A model-based understanding of solid-oxide electrolysis cells (SOECs) for syngas production by H2O/CO2 co-electrolysis

    Menon, Vikram; Fu, Qingxi; Janardhanan, Vinod M.; Deutschmann, Olaf

    2015-01-01

    High temperature co-electrolysis of H2O and CO2 offers a promising route for syngas (H2, CO) production via efficient use of heat and electricity. The performance of a SOEC during co-electrolysis is investigated by focusing on the interactions between transport processes and electrochemical parameters. Electrochemistry at the three-phase boundary is modeled by a modified Butler-Volmer approach that considers H2O electrolysis and CO2 electrolysis, individually, as electrochemically active charge transfer pathways. The model is independent of the geometrical structure. A 42-step elementary heterogeneous reaction mechanism for the thermo-catalytic chemistry in the fuel electrode, the dusty gas model (DGM) to account for multi-component diffusion through porous media, and a plug flow model for flow through the channels are used in the model. Two sets of experimental data are reproduced by the simulations, in order to deduce parameters of the electrochemical model. The influence of micro-structural properties, inlet cathode gas velocity, and temperature are discussed. Reaction flow analysis is performed, at OCV, to study methane production characteristics and kinetics during co-electrolysis. Simulations are carried out for configurations ranging from simple one-dimensional electrochemical button cells to quasi-two-dimensional co-flow planar cells, to demonstrate the effectiveness of the computational tool for performance and design optimization.

  15. Wastewater heat recovery apparatus

    Kronberg, J.W.

    1992-09-01

    A heat recovery system is described with a heat exchanger and a mixing valve. A drain trap includes a heat exchanger with an inner coiled tube, baffle plate, wastewater inlet, wastewater outlet, cold water inlet, and preheated water outlet. Wastewater enters the drain trap through the wastewater inlet, is slowed and spread by the baffle plate, and passes downward to the wastewater outlet. Cold water enters the inner tube through the cold water inlet and flows generally upward, taking on heat from the wastewater. This preheated water is fed to the mixing valve, which includes a flexible yoke to which are attached an adjustable steel rod, two stationary zinc rods, and a pivoting arm. The free end of the arm forms a pad which rests against a valve seat. The rods and pivoting arm expand or contract as the temperature of the incoming preheated water changes. The zinc rods expand more than the steel rod, flexing the yoke and rotating the pivoting arm. The pad moves towards the valve seat as the temperature of the preheated water rises, and away as the temperature falls, admitting a variable amount of hot water to maintain a nearly constant average process water temperature. 6 figs.

  16. Integrating Microbial Electrochemical Technology with Forward Osmosis and Membrane Bioreactors: Low-Energy Wastewater Treatment, Energy Recovery and Water Reuse

    Werner, Craig M.

    2014-06-01

    Wastewater treatment is energy intensive, with modern wastewater treatment processes consuming 0.6 kWh/m3 of water treated, half of which is required for aeration. Considering that wastewater contains approximately 2 kWh/m3 of energy and represents a reliable alternative water resource, capturing part of this energy and reclaiming the water would offset or even eliminate energy requirements for wastewater treatment and provide a means to augment traditional water supplies. Microbial electrochemical technology is a novel technology platform that uses bacteria capable of producing an electric current outside of the cell to recover energy from wastewater. These bacteria do not require oxygen to respire but instead use an insoluble electrode as their terminal electron acceptor. Two types of microbial electrochemical technologies were investigated in this dissertation: 1) a microbial fuel cell that produces electricity; and 2) a microbial electrolysis cell that produces hydrogen with the addition of external power. On their own, microbial electrochemical technologies do not achieve sufficiently high treatment levels. Innovative approaches that integrate microbial electrochemical technologies with emerging and established membrane-based treatment processes may improve the overall extent of wastewater treatment and reclaim treated water. Forward osmosis is an emerging low-energy membrane-based technology for seawater desalination. In forward osmosis water is transported across a semipermeable membrane driven by an osmotic gradient. The microbial osmotic fuel cell described in this dissertation integrates a microbial fuel cell with forward osmosis to achieve wastewater treatment, energy recovery and partial desalination. This system required no aeration and generated more power than conventional microbial fuel cells using ion exchange membranes by minimizing electrochemical losses. Membrane bioreactors incorporate semipermeable membranes within a biological wastewater

  17. Electrochemical oxidation of synthetic tannery wastewater in chloride-free aqueous media

    Costa, Carla Regina; Montilla, Francisco; Morallon, Emilia; Olivi, Paulo

    2010-01-01

    The electrochemical treatment of a synthetic tannery wastewater, prepared with several compounds used by finishing tanneries, was studied in chloride-free media. Boron-doped diamond (Si/BDD), antimony-doped tin dioxide (Ti/SnO 2 -Sb), and iridium-antimony-doped tin dioxide (Ti/SnO 2 -Sb-Ir) were evaluated as anode. The influence of pH and current density on the treatment was assessed by means of the parameters used to measure the level of organic contaminants in the wastewater; i.e., total phenols, chemical oxygen demand (COD), total organic carbon (TOC), and absorbance. Results showed that faster decrease in these parameters occurred when the Si/BDD anode was used. Good results were obtained with the Ti/SnO 2 -Sb anode, but its complete deactivation was reached after 4 h of electrolysis at 25 mA cm -2 , indicating that the service life of this electrode is short. The Ti/SnO 2 -Sb-Ir anode is chemically and electrochemically more stable than the Ti/SnO 2 -Sb anode, but it is not suitable for the electrochemical treatment under the studied conditions. No significant changes were observed for electrolyses performed at different pH conditions with Si/BDD, and this electrode led to almost complete mineralization after 4 h of electrolysis at 100 mA cm -2 . The increase in current density resulted in faster wastewater oxidation, with lower current efficiency and higher energy consumption. Si/BBD proved to be the best electrodic material for the direct electrooxidation of tannery wastewaters.

  18. Advancements in oxygen generation and humidity control by water vapor electrolysis

    Heppner, D. B.; Sudar, M.; Lee, M. C.

    1988-01-01

    Regenerative processes for the revitalization of manned spacecraft atmospheres or other manned habitats are essential for realization of long-term space missions. These processes include oxygen generation through water electrolysis. One promising technique of water electrolysis is the direct conversion of the water vapor contained in the cabin air to oxygen. This technique is the subject of the present program on water vapor electrolysis development. The objectives were to incorporate technology improvements developed under other similar electrochemical programs and add new ones; design and fabricate a mutli-cell electrochemical module and a testing facility; and demonstrate through testing the improvements. Each aspect of the water vapor electrolysis cell was reviewed. The materials of construction and sizing of each element were investigated analytically and sometime experimentally. In addition, operational considerations such as temperature control in response to inlet conditions were investigated. Three specific quantitative goals were established.

  19. Microbial electrolysis desalination and chemical-production cell for CO2 sequestration

    Zhu, Xiuping; Logan, Bruce E.

    2014-01-01

    Mineral carbonation can be used for CO2 sequestration, but the reaction rate is slow. In order to accelerate mineral carbonation, acid generated in a microbial electrolysis desalination and chemical-production cell (MEDCC) was examined to dissolve

  20. Phosphate recovery as struvite within a single chamber microbial electrolysis cell

    Cusick, Roland D.; Logan, Bruce E.

    2012-01-01

    An energy efficient method of concurrent hydrogen gas and struvite (MgNH 4PO 4·6H 2O) production was investigated based on bioelectrochemically driven struvite crystallization at the cathode of a single chamber microbial electrolysis struvite

  1. Procedure and technique critique for tritium enrichment by electrolysis at the IAEA Laboratory (effective November 1976)

    NONE

    1976-11-05

    This publication gives a detailed description of the experimental and calculation procedures for tritium enrichment. Most descriptive sections are divided into 2 parts: Section A describes the procedure in the IAEA laboratory; section B discusses the reasons behind the various procedures, and may indicate alternative acceptable, or in some cases even better, procedures. The description of the equipment focuses on electrolysis cells, cooling system and power supply. Routine procedures are discussed including handling and checking of samples after receipt, 'spike' and blank water, initial sample distillation, preparation of cells and samples for electrolysis, electrolysis and completion of electrolysis (weighing of cells, neutralisation and distillation) and precautions against contaminations (prevention, detection and cure). A list of equipment required for electrolytic enrichment of tritium is provided.

  2. Conjugated oligoelectrolyte represses hydrogen oxidation by Geobacter sulfurreducens in microbial electrolysis cells

    Liu, Jia; Hou, Huijie; Chen, Xiaofen; Bazan, Guillermo C.; Kashima, Hiroyuki; Logan, Bruce

    2015-01-01

    © 2015 Elsevier B.V. A conjugated oligoelectrolyte (COE), which spontaneously aligns within cell membranes, was shown to completely inhibit H2 uptake by Geobacter sulfurreducens in microbial electrolysis cells. Coulombic efficiencies that were 490

  3. THE HIGH-TEMPERATURE ELECTROLYSIS PROGRAM AT THE IDAHO NATIONAL LABORATORY: OBSERVATIONS ON PERFORMANCE DEGRADATION

    J. E. O' Brien; C. M. Stoots; J. S. Herring; K. G. Condie; G. K. Housley

    2009-06-01

    This paper presents an overview of the high-temperature electrolysis research and development program at the Idaho National Laboratory, with selected observations of electrolysis cell degradation at the single-cell, small stack and large facility scales. The objective of the INL program is to address the technical and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for hydrogen production from steam. In the envisioned application, high-temperature electrolysis would be coupled to an advanced nuclear reactor for efficient large-scale non-fossil non-greenhouse-gas hydrogen production. The program supports a broad range of activities including small bench-scale experiments, larger scale technology demonstrations, detailed computational fluid dynamic modeling, and system modeling. A summary of the current status of these activities and future plans will be provided, with a focus on the problem of cell and stack degradation.

  4. 31. Introduction with adjacent production of foundry and rolling department of electrolysis shop

    Ivanov, A.V.

    1993-01-01

    The introduction with adjacent production of foundry and rolling department of electrolysis shop was conducted. The foundry machine was described. The chemical properties of aluminium for ferrous alloy production were defined.

  5. A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

    Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

    2015-12-01

    The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Hydrogen Production System with High Temperature Electrolysis for Nuclear Power Plant

    Kentaro, Matsunaga; Eiji, Hoashi; Seiji, Fujiwara; Masato, Yoshino; Taka, Ogawa; Shigeo, Kasai

    2006-01-01

    Steam electrolysis with solid oxide cells is one of the most promising methods for hydrogen production, which has the potential to be high efficiency. Its most parts consist of environmentally sound and common materials. Recent development of ceramics with high ionic conductivity suggests the possibility of widening the range of operating temperature with maintaining the high efficiency. Toshiba is constructing a hydrogen production system with solid oxide electrolysis cells for nuclear power plants. Tubular-type cells using YSZ (Yttria-Stabilized- Zirconia) as electrolyte showed good performance of steam electrolysis at 800 to 900 deg C. Larger electrolysis cells with present configuration are to be combined with High Temperature Reactors. The hydrogen production efficiency on the present designed system is expected around 50% at 800 to 900 deg C of operating temperature. For the Fast Reactors, 'advanced cell' with higher efficiency at lower temperature are to be introduced. (authors)

  7. Procedure and technique critique for tritium enrichment by electrolysis at the IAEA Laboratory (effective November 1976)

    1976-01-01

    This publication gives a detailed description of the experimental and calculation procedures for tritium enrichment. Most descriptive sections are divided into 2 parts: Section A describes the procedure in the IAEA laboratory; section B discusses the reasons behind the various procedures, and may indicate alternative acceptable, or in some cases even better, procedures. The description of the equipment focuses on electrolysis cells, cooling system and power supply. Routine procedures are discussed including handling and checking of samples after receipt, 'spike' and blank water, initial sample distillation, preparation of cells and samples for electrolysis, electrolysis and completion of electrolysis (weighing of cells, neutralisation and distillation) and precautions against contaminations (prevention, detection and cure). A list of equipment required for electrolytic enrichment of tritium is provided

  8. Hydrogen Generation in Microbial Reverse-Electrodialysis Electrolysis Cells Using a Heat-Regenerated Salt Solution

    Nam, Joo-Youn; Cusick, Roland D.; Kim, Younggy; Logan, Bruce E.

    2012-01-01

    Hydrogen gas can be electrochemically produced in microbial reverse-electrodialysis electrolysis cells (MRECs) using current derived from organic matter and salinity-gradient energy such as river water and seawater solutions. Here, it is shown

  9. Study of the effect of pressure on electrolysis of H2O and co-electrolysis of H2O and CO2 at high temperature

    Bernadet, Lucile

    2016-01-01

    This thesis work investigates the behavior of a solid oxide cell operating under pressure in high temperature steam electrolysis and co-electrolysis mode (H 2 O and CO 2 ). The experimental study of single cell associated with the development of multi-physical models have been set up. The experiments, carried out using an original test bench developed by the CEA-Grenoble on two types of cells between 1 and 10 bar and 700 to 800 C, allowed to identify in both operating modes that the pressure has a positive or negative effect on performance depending on the cell operating point (current, voltage). In addition, gas analyzes performed in co-electrolysis led to detect in situ CH 4 production under pressure. These pressure effects were simulated by models calibrated at atmospheric pressure. Simulations analysis helped identify the pressure dependent mechanisms and propose operating conditions thanks to the establishment of operating maps. (author) [fr

  10. Stainless steel anodes for alkaline water electrolysis and methods of making

    Soloveichik, Grigorii Lev

    2014-01-21

    The corrosion resistance of stainless steel anodes for use in alkaline water electrolysis was increased by immersion of the stainless steel anode into a caustic solution prior to electrolysis. Also disclosed herein are electrolyzers employing the so-treated stainless steel anodes. The pre-treatment process provides a stainless steel anode that has a higher corrosion resistance than an untreated stainless steel anode of the same composition.

  11. Microbial electrolysis cells turning to be versatile technology: recent advances and future challenges

    Zhang, Yifeng; Angelidaki, Irini

    2014-01-01

    and achieve high-yield hydrogen production from wide range of organic matters at relatively mild conditions. This approach greatly reduces the electric energy cost for hydrogen production in contrast to direct water electrolysis. In addition to hydrogen production, MECs may also support several energetically......Microbial electrolysis cells (MECs) are an electricity-mediated microbial bioelectrochemical technology, which is originally developed for high-efficiency biological hydrogen production from waste streams. Compared to traditional biological technologies, MECs can overcome thermodynamic limitations...

  12. Life Time Performance Characterization of Solid Oxide Electrolysis Cells for Hydrogen Production

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

    2015-01-01

    Solid oxide electrolysis cells (SOECs) offer a promising technological solution for efficient energy conversion and production of hydrogen or syngas. The commercialization of the SOEC technology can be promoted if SOECs can be operated at high current density with stable performance over ~5 years...... - 3 years (continuous operation, setting 1.5 V as the upper voltage defining “end of life”). The results provide technological input to future design of electrolysis plants for hydrogen production. © 2015 ECS - The Electrochemical Society...

  13. Enhancing the efficiency of zero valent iron by electrolysis: Performance and reaction mechanism.

    Xiong, Zhaokun; Lai, Bo; Yang, Ping

    2018-03-01

    Electrolysis was applied to enhance the efficiency of micron-size zero valent iron (mFe 0 ) and thereby promote p-nitrophenol (PNP) removal. The rate of PNP removal by mFe 0 with electrolysis was determined in cylindrical electrolysis reactor that employed annular aluminum plate cathode as a function of experimental factors, including initial pH, mFe 0 dosage and current density. The rate constants of PNP removal by Ele-mFe 0 were 1.72-144.50-fold greater than those by pristine mFe 0 under various tested conditions. The electrolysis-induced improvement could be primarily ascribed to stimulated mFe 0 corrosion, as evidenced by Fe 2+ release. The application of electrolysis could extend the working pH range of mFe 0 from 3.0 to 6.0 to 3.0-10.0 for PNP removal. Additionally, intermediates analysis and scavengers experiments unraveled the reduction capacity of mFe 0 was accelerated in the presence of electrolysis instead of oxidation. Moreover, the electrolysis effect could also delay passivation of mFe 0 under acidic condition, as evidenced by SEM-EDS, XRD, and XPS analysis after long-term operation. This is mainly due to increased electromigration meaning that iron corrosion products (iron hydroxides and oxides) are not primarily formed in the vicinity of the mFe 0 or at its surface. In the presence of electrolysis, the effect of electric field significantly promoted the efficiency of electromigration, thereby enhanced mFe 0 corrosion and eventually accelerated the PNP removal rates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Research on dispose of wastewater from printing and dyeing by CWF combined with Iron-carbon Microelectrolysis

    Chen, Xin; Ye, Tingjin; Xu, Zizhen; Chen, Xiaogang; Shi, Liang; He, Lingfeng; Zhang, Yongli

    2018-03-01

    The carboxymethylchitosan cladding coal ash (CWF) was oxidized by the high temperature using coal ash and sodium carboxymethyl chitosan as raw and processed material for treatment of simulated and actual printing and dyeing wastewater over iron-carbon micro-electrolysis. The results on pH and CWF dosage for effluent dispose were evaluated by the decolorization rate, COD removal efficiency and turbidity removal rate. The experimental results indicated that the decolorization rate was first augmented and then declined with the increase of pH, and attained a peak value when pH was at 5-6. The COD removal efficiency augmented with the augmented of pH, and attained a peak value when pH was 6-7. The turbidity removal rate was first increases and afterwards decreases with the augment of pH, and attained a peak value when pH was at 5-6. Furthermore, the optimum pH for the treatment of simulated dyeing wastewater was 6 over iron-carbon micro-electrolysis, which indicated that the appropriate pH can promote the degradation of wastewater.

  15. High performance of nitrogen and phosphorus removal in an electrolysis-integrated biofilter.

    Gao, Y; Xie, Y W; Zhang, Q; Yu, Y X; Yang, L Y

    A novel electrolysis-integrated biofilter system was developed in this study to evaluate the intensified removal of nitrogen and phosphorus from contaminated water. Two laboratory-scale biofilter systems were established, one with electrolysis (E-BF) and one without electrolysis (BF) as control. The dynamics of intensified nitrogen and phosphorus removal and the changes of inflow and outflow water qualities were also evaluated. The total nitrogen (TN) removal rate was 94.4% in our newly developed E-BF, but only 74.7% in the control BF. Ammonium removal rate was up to 95% in biofilters with or without electrolysis integration with an influent ammonium concentration of 40 mg/L, and the accumulation of nitrate and nitrite was much lower in the effluent of E-BF than that of BF. Thus electrolysis plays an important role in TN removal especially the nitrate and nitrite removal. Phosphorus removal was significantly enhanced, exceeding 90% in E-BF by chemical precipitation, physical adsorption, and flocculation of phosphorus because of the in situ formation of ferric ions by the anodizing of sacrificial iron anodes. Results from this study indicate that the electrolysis integrated biofilter is a promising solution for intensified nitrogen and phosphorus removal.

  16. Treatment of winery wastewater by anodic oxidation using BDD electrode.

    Candia-Onfray, Christian; Espinoza, Nicole; Sabino da Silva, Evanimek B; Toledo-Neira, Carla; Espinoza, L Carolina; Santander, Rocío; García, Verónica; Salazar, Ricardo

    2018-05-04

    The effective removal of organics from winery wastewater was obtained in real residual effluents from the wine industry using anodic oxidation (AO). The effluent had an initial organic load of [COD] 0 of 3490 mg L -1 equal to [TOC] 0 of 1320 mg L -1 . In addition, more than 40 organic compounds were identified by means of GC-MS. Different density currents as well as the addition of electrolytes were tested during electrolysis. The results show the decay of [COD] t by 63.6% when no support electrolyte was added, whereas almost total mineralization and disinfection was reached after adding of 50 mM of sodium sulfate and sodium chloride and applying higher density currents. The presence of sulfate and chloride in large concentration favors the production of oxidants such as hydroxyl radicals and active chlorine species that react with organics in solution. Moreover, the addition of a supporting electrolyte to industrial wastewater increases conductivity, reduces cell potential and therefore, decreases the energy consumption of the AO process. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor.

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

    2012-11-15

    Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8±1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 gm(-3) d(-1)) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 gm(-3) d(-1) (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Enhanced removal of chemical oxygen demand, nitrogen and phosphorus using the ameliorative anoxic/anaerobic/oxic process and micro-electrolysis.

    Bao, K Q; Gao, J Q; Wang, Z B; Zhang, R Q; Zhang, Z Y; Sugiura, N

    2012-01-01

    Synthetic wastewater was treated using a novel system integrating the reversed anoxic/anaerobic/oxic (RAAO) process, a micro-electrolysis (ME) bed and complex biological media. The system showed superior chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) removal rates. Performance of the system was optimised by considering the influences of three major controlling factors, namely, hydraulic retention time (HRT), organic loading rate (OLR) and mixed liquor recirculation (MLR). TP removal efficiencies were 69, 87, 87 and 83% under the HRTs of 4, 8, 12 and 16 h. In contrast, HRT had negligible effects on the COD and TN removal efficiencies. COD, TN and TP removal efficiencies from synthetic wastewater were 95, 63 and 87%, respectively, at an OLR of 1.9 g/(L·d). The concentrations of COD, TN and TP in the effluent were less than 50, 15 and 1 mg/L, respectively, at the controlled MLR range of 75-100%. In this system, organics, TN and TP were primarily removed from anoxic tank regardless of the operational conditions.

  19. Inactivation characteristics of ozone and electrolysis process for ballast water treatment using B. subtilis spores as a probe.

    Jung, Youmi; Yoon, Yeojoon; Hong, Eunkyung; Kwon, Minhwan; Kang, Joon-Wun

    2013-07-15

    Since ballast water affects the ocean ecosystem, the International Maritime Organization (IMO) sets a standard for ballast water management and might impose much tighter regulations in the future. The aim of this study is to evaluate the inactivation efficiency of ozonation, electrolysis, and an ozonation-electrolysis combined process, using B. subtilis spores. In seawater ozonation, HOBr is the key active substance for inactivation, because of rapid reactivity of ozone with Br(-) in seawater. In seawater electrolysis, it is also HOBr, but not HOCl, because of the rapid reaction of HOCl with Br(-), which has not been recognized carefully, even though many electrolysis technologies have been approved by the IMO. Inactivation pattern was different in ozonation and electrolysis, which has some limitations with the tailing or lag-phase, respectively. However, each deficiency can be overcome with a combined process, which is most effective as a sequential application of ozonation followed by electrolysis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Basic Principles of Wastewater Treatment

    Von Sperling, Marcos

    2007-01-01

    "Basic Principles of Wastewater Treatment is the second volume in the series Biological Wastewater Treatment, and focusses on the unit operations and processes associated with biological wastewater treatment. The major topics covered are: microbiology and ecology of wastewater treatment reaction kinetics and reactor hydraulics conversion of organic and inorganic matter sedimentation aeration The theory presented in this volume forms the basis upon which the other books...

  1. Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: Comparison of electrode materials and electrode connection systems

    Solak, Murat [Duezce University, Kaynasli Vocational School, Environmental Protection and Control Department, 81900 Duezce (Turkey); Kilic, Mehmet, E-mail: kavi@mmf.sdu.edu.tr [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey); Hueseyin, Yazici; Sencan, Aziz [Sueleyman Demirel University, Engineering and Architecture Faculty, Environmental Engineering Department, 32260 Isparta (Turkey)

    2009-12-15

    In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m{sup 2}, and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m{sup 2}, respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

  2. Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: Comparison of electrode materials and electrode connection systems

    Solak, Murat; Kilic, Mehmet; Hueseyin, Yazici; Sencan, Aziz

    2009-01-01

    In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m 2 , and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m 2 , respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

  3. Removal of suspended solids and turbidity from marble processing wastewaters by electrocoagulation: comparison of electrode materials and electrode connection systems.

    Solak, Murat; Kiliç, Mehmet; Hüseyin, Yazici; Sencan, Aziz

    2009-12-15

    In this study, removal of suspended solids (SS) and turbidity from marble processing wastewaters by electrocoagulation (EC) process were investigated by using aluminium (Al) and iron (Fe) electrodes which were run in serial and parallel connection systems. To remove these pollutants from the marble processing wastewater, an EC reactor including monopolar electrodes (Al/Fe) in parallel and serial connection system, was utilized. Optimization of differential operation parameters such as pH, current density, and electrolysis time on SS and turbidity removal were determined in this way. EC process with monopolar Al electrodes in parallel and serial connections carried out at the optimum conditions where the pH value was 9, current density was approximately 15 A/m(2), and electrolysis time was 2 min resulted in 100% SS removal. Removal efficiencies of EC process for SS with monopolar Fe electrodes in parallel and serial connection were found to be 99.86% and 99.94%, respectively. Optimum parameters for monopolar Fe electrodes in both of the connection types were found to be for pH value as 8, for electrolysis time as 2 min. The optimum current density value for Fe electrodes used in serial and parallel connections was also obtained at 10 and 20 A/m(2), respectively. Based on the results obtained, it was found that EC process running with each type of the electrodes and the connections was highly effective for the removal of SS and turbidity from marble processing wastewaters, and that operating costs with monopolar Al electrodes in parallel connection were the cheapest than that of the serial connection and all the configurations for Fe electrode.

  4. Microalgal biofilms for wastewater treatment

    Boelee, N.C.

    2013-01-01

    The objective of this thesis was to explore the possibilities of using microalgal biofilms for the treatment of municipal wastewater, with a focus on the post-treatment of municipal wastewater effluent. The potential of microalgal biofilms for wastewater treatment was first investigated using a

  5. Problems with textile wastewater discharge

    Rantala, Pentti

    1987-01-01

    The general character of textile industry wastewaters is briefly discussed. General guidelines and practice in Finland when discharging textile industry wastewaters to municipal sewer systems is described. A survey revealed that most municipalities experience some problems due to textile industry wastewaters. Pretreatment is not always practiced and in some cases pretreatment is not operated efficiently. (author)

  6. Synergistic Effects of Micro-electrolysis-Photocatalysis on Water Treatment and Fish Performance in Saline Recirculating Aquaculture System

    Ye, Zhangying; Wang, Shuo; Gao, Weishan; Li, Haijun; Pei, Luowei; Shen, Mingwei; Zhu, Songming

    2017-01-01

    A new physico-chemical process for TAN (total ammonia nitrogen) removal and disinfection is introduced in saline recirculating aquaculture system (RAS), in which the biofilter is replaced with an integrated electrolysis cell and an activated carbon filter. The electrolysis cell which is based on micro current electrolysis combined with UV-light was self-designed. After the fundamental research, a small pilot scale RAS was operated for 30 days to verify the technical feasibility. The system wa...

  7. Improving The Efficiency Of Ammonia Electrolysis For Hydrogen Production

    Palaniappan, Ramasamy

    Given the abundance of ammonia in domestic and industrial wastes, ammonia electrolysis is a promising technology for remediation and distributed power generation in a clean and safe manner. Efficiency has been identified as one of the key issues that require improvement in order for the technology to enter the market phase. Therefore, this research was performed with the aim of improving the efficiency of hydrogen production by finding alternative materials for the cathode and electrolyte. 1. In the presence of ammonia the activity for hydrogen evolution reaction (HER) followed the trend Rh>Pt>Ru>Ni. The addition of ammonia resulted in lower rates for HER for Pt, Ru, and Ni, which have been attributed to competition from the ammonia adsorption reaction. 2. The addition of ammonia offers insight into the role of metal-hydrogen underpotential deposition (M-Hupd) on HER kinetics. In addition to offering competition via ammonia adsorption it resulted in fewer and weaker M-Hupd bonds for all metals. This finding substantiates the theory that M-Hupd bonds favor HER on Pt electrocatalyst. However, for Rh results suggest that M-Hupd bond may hinder the HER. In addition, the presence of unpaired valence shell electrons is suggested to provide higher activity for HER in the presence of ammonia. 3. Bimetals PtxM1-x (M = Ir, Ru, Rh, and Ni) offered lower overpotentials for HER compared to the unalloyed metals in the presence of ammonia. The activity of HER in the presence of ammonia follows the trend Pt-Ir>Pt-Rh>Pt-Ru>Pt-Ni. The higher activity of HER is attributed to the synergistic effect of the alloy, where ammonia adsorbs onto the more electropositive alloying metal leaving Pt available for Hupd formation and HER to take place. Additionally, this supports the theory that the presence of a higher number of unpaired electrons favors the HER in the presence of ammonia. 4. Potassium polyacrylate (PAA-K) was successfully used as a substitute for aqueous KOH for ammonia

  8. LCA of Wastewater Treatment

    Larsen, Henrik Fred

    2018-01-01

    of LCA studies addressing wastewater treatment have from the very first published cases, been on energy and resource consumption. In recent time, the use of characterisation has increased and besides global warming potential, especially eutrophication is in focus. Even the toxicity-related impact......The main purpose of wastewater treatment is to protect humans against waterborne diseases and to safeguard aquatic bio-resources like fish. The dominating environmental concerns within this domain are indeed still potential aquatic eutrophication/oxygen depletion due to nutrient/organic matter...

  9. Strategies for Reducing the Start-up Operation of Microbial Electrochemical Treatments of Urban Wastewater

    Zulema Borjas

    2015-12-01

    Full Text Available Microbial electrochemical technologies (METs constitute the core of a number of emerging technologies with a high potential for treating urban wastewater due to a fascinating reaction mechanism—the electron transfer between bacteria and electrodes to transform metabolism into electrical current. In the current work, we focus on the model electroactive microorganism Geobacter sulfurreducens to explore both the design of new start-up procedures and electrochemical operations. Our chemostat-grown plug and play cells, were able to reduce the start-up period by 20-fold while enhancing chemical oxygen demand (COD removal by more than 6-fold during this period. Moreover, a filter-press based bioreactor was successfully tested for both acetate-supplemented synthetic wastewater and real urban wastewater. This proof-of-concept pre-pilot treatment included a microbial electrolysis cell (MEC followed in time by a microbial fuel cell (MFC to finally generate electrical current of ca. 20 A·m−2 with a power of 10 W·m−2 while removing 42 g COD day−1·m−2. The effective removal of acetate suggests a potential use of this modular technology for treating acetogenic wastewater where Geobacter sulfurreducens outcompetes other organisms.

  10. Wastewater treatment by nanofiltration membranes

    Mulyanti, R.; Susanto, H.

    2018-03-01

    Lower energy consumption compared to reverse osmosis (RO) and higher rejection compared to ultrafiltration make nanofiltration (NF) membrane get more and more attention for wastewater treatment. NF has become a promising technology not only for treating wastewater but also for reusing water from wastewater. This paper presents various application of NF for wastewater treatments. The factors affecting the performance of NF membranes including operating conditions, feed characteristics and membrane characteristics were discussed. In addition, fouling as a severe problem during NF application is also presented. Further, future prospects and challenges of NF for wastewater treatments are explained.

  11. Electrode kinetics of a water vapor electrolysis cell

    Jacobs, G.

    1974-01-01

    The anodic electrochemical behavior of the water vapor electrolysis cell was investigated. A theoretical review of various aspects of cell overvoltage is presented with special emphasis on concentration overvoltage and activation overvoltage. Other sources of overvoltage are described. The experimental apparatus controlled and measured anode potential and cell current. Potentials between 1.10 and 2.60 V (vs NHE) and currents between 0.1 and 3000 mA were investigated. Different behavior was observed between the standard cell and the free electrolyte cell. The free electrolyte cell followed typical Tafel behavior (i.e. activation overvoltage) with Tafel slopes of about 0.15, and the exchange current densities of 10 to the minus 9th power A/sq cm, both in good agreement with literature values. The standard cell exhibitied this same Tafel behavior at lower current densities but deviated toward lower than expected current densities at higher potentials. This behavior and other results were examined to determine their origin.

  12. Porous poly(perfluorosulfonic acid) membranes for alkaline water electrolysis

    Aili, David; Hansen, Martin Kalmar; Andreasen, Jens Wenzel

    2015-01-01

    Poly(perfluorosulfonic acid) (PFSA) is one of a few polymer types that combine excellent alkali resistance with extreme hydrophilicity. It is therefore of interest as a base material in separators for alkaline water electrolyzers. In the pristine form it, however, shows high cation selectivity. T...... for the unmodified membrane. The technological feasibility was demonstrated by testing the membranes in an alkaline water electrolysis cell with encouraging performance.......Poly(perfluorosulfonic acid) (PFSA) is one of a few polymer types that combine excellent alkali resistance with extreme hydrophilicity. It is therefore of interest as a base material in separators for alkaline water electrolyzers. In the pristine form it, however, shows high cation selectivity...... and washed out and the obtained porous materials allowed for swelling to reach water contents up to λ=85 [H2O] [−SO3K]−1. After equilibration in 22 wt% aqueous KOH, ion conductivity of 0.2 S cm−1 was recorded for this membrane type at room temperature, which is significantly higher than 0.01 S cm−1...

  13. Methanobacterium Dominates Biocathodic Archaeal Communities in Methanogenic Microbial Electrolysis Cells

    Siegert, Michael

    2015-07-06

    © 2015 American Chemical Society. Methane is the primary end product from cathodic current in microbial electrolysis cells (MECs) in the absence of methanogenic inhibitors, but little is known about the archaeal communities that develop in these systems. MECs containing cathodes made from different materials (carbon brushes, or plain graphite blocks or blocks coated with carbon black and platinum, stainless steel, nickel, ferrihydrite, magnetite, iron sulfide, or molybdenum disulfide) were inoculated with anaerobic digester sludge and acclimated at a set potential of -600 mV (versus a standard hydrogen electrode). The archaeal communities on all cathodes, except those coated with platinum, were predominated by Methanobacterium (median 97% of archaea). Cathodes with platinum contained mainly archaea most similar to Methanobrevibacter. Neither of these methanogens were abundant (<0.1% of archaea) in the inoculum, and therefore their high abundance on the cathode resulted from selective enrichment. In contrast, bacterial communities on the cathode were more diverse, containing primarily δ-Proteobacteria (41% of bacteria). The lack of a consistent bacterial genus on the cathodes indicated that there was no similarly selective enrichment of bacteria on the cathode. These results suggest that the genus Methanobacterium was primarily responsible for methane production in MECs when cathodes lack efficient catalysts for hydrogen gas evolution. (Figure Presented).

  14. Degradation of Anionic Dye Eosin by Glow Discharge Electrolysis Plasma

    Gao Jinzhang; Ma Dongping; Guo Xiao; Wang Aixiang; Fu Yan; Wu Jianlin; Yang Wu

    2008-01-01

    This paper describes a novel method for the degradation of eosin by using glow discharge electrolysis (GDE). The effects of various parameters on the removal efficiency were studied. It was found that the eosin degradation could be raised considerably by increasing the applied voltage and the initial concentration, or by decreasing pH of the aqueous solution. Fe 2+ ion had an evident accelerating effect on the eosin degradation. The degradation process of eosin obeyed a pseudo-first-order reaction. The relationship between the degradation rate constant k and the reaction temperature T could be expressed by Arrhenius equation with which the apparent activation energy Ea of 14.110 kJ. mol -1 and the pre-exponential factor ko of 2.065x10 -1 min -1 were obtained, too. The determination of hydroxyl radical was carried out by using N,N-dimethyl-p-nitrosoaniline (RNO) as a scavenger. The results showed that the hydroxyl radical plays an important role in the degradation process.

  15. Degradation of Anionic Dye Eosin by Glow Discharge Electrolysis Plasma

    Gao, Jinzhang; Ma, Dongping; Guo, Xiao; Wang, Aixiang; Fu, Yan; Wu, Jianlin; Yang, Wu

    2008-08-01

    This paper describes a novel method for the degradation of eosin by using glow discharge electrolysis (GDE). The effects of various parameters on the removal efficiency were studied. It was found that the eosin degradation could be raised considerably by increasing the applied voltage and the initial concentration, or by decreasing pH of the aqueous solution. Fe2+ ion had an evident accelerating effect on the eosin degradation. The degradation process of eosin obeyed a pseudo-first-order reaction. The relationship between the degradation rate constant k and the reaction temperature T could be expressed by Arrhenius equation with which the apparent activation energy Ea of 14.110 kJ. mol-1 and the pre-exponential factor ko of 2.065×10-1 min-1 were obtained, too. The determination of hydroxyl radical was carried out by using N,N-dimethyl-p-nitrosoaniline (RNO) as a scavenger. The results showed that the hydroxyl radical plays an important role in the degradation process.

  16. Modeling Degradation in Solid Oxide Electrolysis Cells - Volume II

    Manohar Motwani

    2011-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential,, within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, non-equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  17. Molybdenum sulphides on carbon supports as electrocatalysts for hydrogen evolution in acidic industrial wastewater

    Kokko, M.; Bayerköhler, F.; Erben, J.; Zengerle, R.; Kurz, Ph.; Kerzenmacher, S.

    2017-01-01

    Highlights: • MoS_x is an efficient and durable catalyst for H_2 evolution in acidic wastewater. • MoS_x outperformed Pt as H_2-catalyst in long term in acidic wastewater. • Improved activity over time was likely due to changes in MoS_x structure. - Abstract: Microbial electrolysis cells (MECs) are an attractive future alternative technology to generate renewable hydrogen and simultaneously treat wastewaters. The thermodynamics of hydrogen evolution in MECs can be greatly improved by operating the cathode at acidic pH in combination with a neutral pH microbial anode. This can easily be achieved with acidic industrial wastewaters that have to be neutralised before discharge. For the hydrogen evolution reaction (HER) in acidic wastewater, efficient and inexpensive catalysts are required that are compatible with the often complex chemical composition of wastewaters. In this study, molybdenum sulphides (MoS_x) on different carbon supports were successfully used for hydrogen evolution in different acidic media. At first, the cathodes were screened by linear sweep voltammetry in sulphuric acid (pH 0) or phosphate buffer (pH 2.2). After this, the overpotentials for H_2 production of the best cathodes and their long term performances (⩾1 week) were determined in acidic industrial wastewater (pH 2.4) obtained from a plant mainly producing cellulose acetate. For the most promising MoS_x cathodes, the overpotentials for HER (at 3 mA cm"−"2) were only ∼40 mV higher than for a platinum electrode. Most importantly, the catalytic efficiency of the MoS_x electrodes improved in the wastewater over time (7–17 days), while Pt electrodes were found to be slowly deactivated. Thus, MoS_x emerges as an affordable, efficient and especially durable electrocatalyst for HER in real acidic wastewaters and this could be an important contribution to take energy production from wastewaters in the form of hydrogen towards practical applications.

  18. Paper 1: Wastewater characterisation

    drinie

    1998). Research is directed on quantifying the C, N and P fractions in the secondary ... and prefermented wastewater, applicable for a basic in-line APT and other prefermenter ... representative composite samples, and from these samples the ... Constituents in true solution (dissolved) (particle size < 1 nm);. • not visible by ...

  19. Techniques of Wastewater Treatment

    organisms: These are small plants as well as animals and they are some of the most difficult ... It is measured by the oxygen consumption of a pre-inoculated sample at 20-250C in .... Organic wastewater components may be oxidised all the way to CO2.

  20. Energy positive domestic wastewater treatment: the roles of anaerobic and phototrophic technologies

    Shoener, B. D.

    2014-01-01

    The negative energy balance of wastewater treatment could be reversed if anaerobic technologies were implemented for organic carbon oxidation and phototrophic technologies were utilized for nutrient recovery. To characterize the potential for energy positive wastewater treatment by anaerobic and phototrophic biotechnologies we performed a comprehensive literature review and analysis, focusing on energy production (as kJ per capita per day and as kJ m-3 of wastewater treated), energy consumption, and treatment efficacy. Anaerobic technologies included in this review were the anaerobic baffled reactor (ABR), anaerobic membrane bioreactor (AnMBR), anaerobic fluidized bed reactor (AFB), upflow anaerobic sludge blanket (UASB), anaerobic sequencing batch reactor (ASBR), microbial electrolysis cell (MEC), and microbial fuel cell (MFC). Phototrophic technologies included were the high rate algal pond (HRAP), photobioreactor (PBR), stirred tank reactor, waste stabilization pond (WSP), and algal turf scrubber (ATS). Average energy recovery efficiencies for anaerobic technologies ranged from 1.6% (MFC) to 47.5% (ABR). When including typical percent chemical oxygen demand (COD) removals by each technology, this range would equate to roughly 40-1200 kJ per capita per day or 110-3300 kJ m-3 of treated wastewater. The average bioenergy feedstock production by phototrophic technologies ranged from 1200-4700 kJ per capita per day or 3400-13000 kJ m-3 (exceeding anaerobic technologies and, at times, the energetic content of the influent organic carbon), with usable energy production dependent upon downstream conversion to fuels. Energy consumption analysis showed that energy positive anaerobic wastewater treatment by emerging technologies would require significant reductions of parasitic losses from mechanical mixing and gas sparging. Technology targets and critical barriers for energy-producing technologies are identified, and the role of integrated anaerobic and phototrophic

  1. Energy positive domestic wastewater treatment: the roles of anaerobic and phototrophic technologies.

    Shoener, B D; Bradley, I M; Cusick, R D; Guest, J S

    2014-05-01

    The negative energy balance of wastewater treatment could be reversed if anaerobic technologies were implemented for organic carbon oxidation and phototrophic technologies were utilized for nutrient recovery. To characterize the potential for energy positive wastewater treatment by anaerobic and phototrophic biotechnologies we performed a comprehensive literature review and analysis, focusing on energy production (as kJ per capita per day and as kJ m(-3) of wastewater treated), energy consumption, and treatment efficacy. Anaerobic technologies included in this review were the anaerobic baffled reactor (ABR), anaerobic membrane bioreactor (AnMBR), anaerobic fluidized bed reactor (AFB), upflow anaerobic sludge blanket (UASB), anaerobic sequencing batch reactor (ASBR), microbial electrolysis cell (MEC), and microbial fuel cell (MFC). Phototrophic technologies included were the high rate algal pond (HRAP), photobioreactor (PBR), stirred tank reactor, waste stabilization pond (WSP), and algal turf scrubber (ATS). Average energy recovery efficiencies for anaerobic technologies ranged from 1.6% (MFC) to 47.5% (ABR). When including typical percent chemical oxygen demand (COD) removals by each technology, this range would equate to roughly 40-1200 kJ per capita per day or 110-3300 kJ m(-3) of treated wastewater. The average bioenergy feedstock production by phototrophic technologies ranged from 1200-4700 kJ per capita per day or 3400-13 000 kJ m(-3) (exceeding anaerobic technologies and, at times, the energetic content of the influent organic carbon), with usable energy production dependent upon downstream conversion to fuels. Energy consumption analysis showed that energy positive anaerobic wastewater treatment by emerging technologies would require significant reductions of parasitic losses from mechanical mixing and gas sparging. Technology targets and critical barriers for energy-producing technologies are identified, and the role of integrated anaerobic and

  2. Thermodynamic evaluation of geothermal energy powered hydrogen production by PEM water electrolysis

    Yilmaz, Ceyhun; Kanoglu, Mehmet

    2014-01-01

    Thermodynamic energy and exergy analysis of a PEM water electrolyzer driven by geothermal power for hydrogen production is performed. For this purpose, work is produced from a geothermal resource by means of the organic Rankine cycle; the resulting work is used as a work input for an electrolysis process; and electrolysis water is preheated by the waste geothermal water. The first and second-law based performance parameters are identified for the considered system and the system performance is evaluated. The effects of geothermal water and electrolysis temperatures on the amount of hydrogen production are studied and these parameters are found to be proportional to each other. We consider a geothermal resource at 160 °C available at a rate of 100 kg/s. Under realistic operating conditions, 3810 kW power can be produced in a binary geothermal power plant. The produced power is used for the electrolysis process. The electrolysis water can be preheated to 80 °C by the geothermal water leaving the power plant and hydrogen can be produced at a rate of 0.0340 kg/s. The energy and exergy efficiencies of the binary geothermal power plant are 11.4% and 45.1%, respectively. The corresponding efficiencies for the electrolysis system are 64.0% and 61.6%, respectively, and those for the overall system are 6.7% and 23.8%, respectively. - Highlights: • Thermodynamic analysis of hydrogen production by PEM electrolysis powered by geothermal energy. • Power is used for electrolyser; used geothermal water is for preheating electrolysis water. • Effect of geothermal water and electrolysis temperatures on the amount of hydrogen production. • Hydrogen can be produced at a rate of 0.0340 kg/s for a resource at 160 °C available at 100 kg/s. • Energy and exergy efficiencies of the overall system are 6.7% and 23.8%, respectively

  3. Hydrogen production by high temperature electrolysis of water vapour and nuclear reactors

    Jean-Pierre Py; Alain Capitaine

    2006-01-01

    This paper presents hydrogen production by a nuclear reactor (High Temperature Reactor, HTR or Pressurized Water Reactor, PWR) coupled to a High Temperature Electrolyser (HTE) plant. With respect to the coupling of a HTR with a HTE plant, EDF and AREVA NP had previously selected a combined cycle HTR scheme to convert the reactor heat into electricity. In that case, the steam required for the electrolyser plant is provided either directly from the steam turbine cycle or from a heat exchanger connected with such cycle. Hydrogen efficiency production is valued using high temperature electrolysis. Electrolysis production of hydrogen can be performed with significantly higher thermal efficiencies by operating in the steam phase than in the water phase. The electrolysis performance is assessed with solid oxide and solid proton electrolysis cells. The efficiency from the three operating conditions (endo-thermal, auto-thermal and thermo-neutral) of a high temperature electrolysis process is evaluated. The technical difficulties to use the gases enthalpy to heat the water are analyzed, taking into account efficiency and technological challenges. EDF and AREVA NP have performed an analysis to select an optimized process giving consideration to plant efficiency, plant operation, investment and production costs. The paper provides pathways and identifies R and D actions to reach hydrogen production costs competitive with those of other hydrogen production processes. (authors)

  4. Intensified nitrogen and phosphorus removal in a novel electrolysis-integrated tidal flow constructed wetland system.

    Ju, Xinxin; Wu, Shubiao; Zhang, Yansheng; Dong, Renjie

    2014-08-01

    A novel electrolysis-integrated tidal flow constructed wetland (CW) system was developed in this study. The dynamics of intensified nitrogen and phosphorus removal and that of hydrogen sulphide control were evaluated. Ammonium removal of up to 80% was achieved with an inflow concentration of 60 mg/L in wetland systems with and without electrolysis integration. Effluent nitrate concentration decreased from 2 mg/L to less than 0.5 mg/L with the decrease in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2) in the electrolysis-integrated wetland system, thus indicating that the current intensity of electrolysis plays an important role in nitrogen transformations. Phosphorus removal was significantly enhanced, exceeding 95% in the electrolysis-integrated CW system because of the in-situ formation of a ferric iron coagulant through the electro-dissolution of a sacrificial iron anode. Moreover, the electrolyzed wetland system effectively inhibits sulphide accumulation as a result of a sulphide precipitation coupled with ferrous-iron electro-dissolution and/or an inhibition of bacterial sulphate reduction under increased aerobic conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial

    José L. Arias-Buría

    2015-01-01

    Full Text Available Objective. To compare effects of ultrasound- (US- guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n=17 group or exercise (n=19 group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions. Shoulder pain (NPRS and disability (DASH were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P<0.01: individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention.

  6. Electrolysis byproduct D2O provides a third way to mitigate CO2

    Schenewerk, William Ernest

    2009-01-01

    Rapid atomic power deployment may be possible without using fast breeder reactors or making undue demands on uranium resource. Using by-product D2O and thorium-U233 in CANDU and RBMK piles may circumvent need for either fast breeder reactors or seawater uranium. Atmospheric CO2 is presently increasing 2.25%/year in proportion to 2.25%/year exponential fossil fuel consumption increase. Roughly 1/3 anthropologic CO2 is removed by various CO2 sinks. CO2 removal is modelled as being proportional to 45-year-earlier CO2 amount above 280 ppm-C Water electrolysis produces roughly 0.1 kg-D20/kWe-y. Material balance assumes each electrolysis stage increases D2O bottoms concentration times 3. Except for first two electrolysis stages, all water from hydrogen consumption is returned to electrolysis. The unique characteristic of this process is the ability to economically burn all deuterium-enriched H2 in vehicles. Condensate from vehicles returns to appropriate electrolysis stage. Fuel cell condensate originally from reformed natural gas may augment second-sage feed. Atomic power expansion is 5%/year, giving 55000 GWe by 2100. World primary energy increases 2.25%/y, exceeding 4000 EJ/y by 2100. CO2 maximum is roughly 600 ppm-C around year 2085. CO2 declines back below 300 ppm-C by 2145 if the 45-year-delay seawater sink remains effective

  7. High Temperature Co‐Electrolysis of Steam and CO2 in an SOC Stack: Performance and Durability

    Chen, Ming; Høgh, Jens Valdemar Thorvald; Nielsen, J. U.

    2013-01-01

    In this work, co‐electrolysis of steam and carbon dioxide was studied in a Topsoe Fuel Cell (TOFC®) 10‐cell stack, containing three different types of Ni/yttria stabilized zirconia (YSZ) electrode supported solid oxide electrolysis cells with a footprint of 12 × 12 cm. The stack was operated at 800...

  8. Solid polymer electrolyte water electrolysis system development. [to generate oxygen for manned space station applications

    1975-01-01

    Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary instrumentation and controls was fabricated and tested. A six man rated, high pressure, high temperature, advanced preprototype WES was developed. This configuration included the design and development of an advanced water electrolysis module, capable of operation at 400 psig and 200 F, and a dynamic phase separator/pump in place of a passive phase separator design. Evaluation of this system demonstrated the goal of safe, unattended automated operation at high pressure and high temperature with an accumulated gas generation time of over 1000 hours.

  9. Technoeconomic analysis of a methanol plant based on gasification of biomass and electrolysis of water

    Clausen, Lasse Røngaard; Houbak, N.; Elmegaard, Brian

    2010-01-01

    , and the low-temperature waste heat is used for district heat production. This results in high total energy efficiencies (similar to 90%) for the plants. The specific methanol costs for the six plants are in the range 11.8-25.3 (sic)/GJ(exergy). The lowest cost is obtained by a plant using electrolysis......Methanol production process configurations based on renewable energy sources have been designed. The processes were analyzed in the thermodynamic process simulation tool DNA. The syngas used for the catalytic methanol production was produced by gasification of biomass, electrolysis of water, CO2...... with a different syngas production method, were compared. The plants achieve methanol exergy efficiencies of 59-72%, the best from a configuration incorporating autothermal reforming of biogas and electrolysis of water for syngas production. The different processes in the plants are highly heat integrated...

  10. Method and system for purification of gas/liquid streams for fuel cells or electrolysis cells

    2013-01-01

    at least one scrubber in the gas/liquid stream at the inlet side of the first electrode of the fuel cell or electrolysis cell; and/or providing at least one scrubber in the gas/liquid stream at the inlet side of the second electrode of the fuel cell or electrolysis cell; and - purifying the gas....../liquid streams towards the first and second electrode; wherein the at least one scrubber in the gas/liquid stream at the inlet side of the first electrode and/or the at least one scrubber in the gas/liquid stream at the inlet side of the second electrode comprises a material suitable as an electrolyte material...... with the at least one scrubber, with the proviso that the fuel cell or electrolysis cell is not a solid oxide cell....

  11. Manufacturing of a micro-tungsten carbide electrode using a supersonic-aided electrolysis process

    Weng, Feng-Tsai; Ho, Chi-Ting

    2008-01-01

    In this study, a novel micromachining technology for fabricating micro parts was described. The original diameter of a tungsten carbide rod was 3 mm, and it was first processed to a rod with a diameter of 50 µm by a precision-grinding process. It could then be machined to the desired diameter by a supersonic-aided electrolysis process. A high-aspect ratio of the micro-tungsten carbide rod was easily obtained by this process. The surface roughness of the sample that was processed by electrolysis with supersonic-aided agitation was compared with that of the sample obtained without agitation. The machined surface of the sample was smooth, and the reason may be that ionized particles in the anode could be removed by supersonic-aided agitation during the electrolysis process. A microelectrode with a tip of approximately 1 µm could be obtained by this process. (technical note)

  12. The Use of Multi-Reactor Cascade Plasma Electrolysis for Linear Alkylbenzene Sulfonate Degradation

    Saksono, Nelson; Ibrahim; Zainah; Budikania, Trisutanti

    2018-03-01

    Plasma electrolysis is a method that can produce large amounts of hydroxyl radicals to degrade organic waste. The purpose of this study is to improve the effectiveness of Linear alkylbenzene sulfonate (LAS) degradation by using multi-reactor cascade plasma electrolysis. The reactor which operated in circulation system, using 3 reactors series flow and 6 L of LAS with initial concentration of 100 ppm. The results show that the LAS degradation can be improved multi-reactor cascade plasma electrolysis. The greatest LAS degradation is achieved up to 81.91% with energy consumption of 2227.34 kJ/mmol that is obtained during 120 minutes by using 600 Volt, 0.03 M of KOH, and 0.5 cm of the anode depth.

  13. A Feasibility Study of Steelmaking by Molten Oxide Electrolysis (TRP9956)

    Donald R. Sadoway; Gerbrand Ceder

    2009-12-31

    Molten oxide electrolysis (MOE) is an extreme form of molten salt electrolysis, a technology that has been used to produce tonnage metals for over 100 years - aluminum, magnesium, lithium, sodium and the rare earth metals specifically. The use of carbon-free anodes is the distinguishing factor in MOE compared to other molten salt electrolysis techniques. MOE is totally carbon-free and produces no CO or CO2 - only O2 gas at the anode. This project is directed at assessing the technical feasibility of MOE at the bench scale while determining optimum values of MOE operating parameters. An inert anode will be identified and its ability to sustain oxygen evalution will be demonstrated.

  14. Decomplexation efficiency and mechanism of Cu(II)-EDTA by H2O2 coupled internal micro-electrolysis process.

    Zhou, Dongfang; Hu, Yongyou; Guo, Qian; Yuan, Weiguang; Deng, Jiefan; Dang, Yapan

    2016-12-29

    Internal micro-electrolysis (IE) coupled with Fenton oxidation (IEF) was a very effective technology for copper (Cu)-ethylenediaminetetraacetic acid (EDTA) wastewater treatment. However, the mechanisms of Cu 2+ removal and EDTA degradation were scarce and lack persuasion in the IEF process. In this paper, the decomplexation and removal efficiency of Cu-EDTA and the corresponding mechanisms during the IEF process were investigated by batch test. An empirical equation and the oxidation reduction potential (ORP) index were proposed to flexibly control IE and the Fenton process, respectively. The results showed that Cu 2+ , total organic carbon (TOC), and EDTA removal efficiencies were 99.6, 80.3, and 83.4%, respectively, under the proper operation conditions of iron dosage of 30 g/L, Fe/C of 3/1, initial pH of 3.0, Fe 2+ /H 2 O 2 molar ratio of 1/4, and reaction time of 20 min, respectively for IE and the Fenton process. The contributions of IE and Fenton to Cu 2+ removal were 91.2 and 8.4%, respectively, and those to TOC and EDTA removal were 23.3, 25.1, and 57, 58.3%, respectively. It was found that Fe 2+ -based replacement-precipitation and hydroxyl radical (•OH) were the most important effects during the IEF process. •OH played an important role in the degradation of EDTA, whose yield and productive rate were 3.13 mg/L and 0.157 mg/(L min -1 ), respectively. Based on the intermediates detected by GC-MS, including acetic acid, propionic acid, pentanoic acid, amino acetic acid, 3-(diethylamino)-1,2-propanediol, and nitrilotriacetic acid (NTA), a possible degradation pathway of Cu-EDTA in the IEF process was proposed. Graphical abstract The mechanism diagram of IEF process.

  15. Separation factor dependence upon cathode material for tritium separation from heavy water by electrolysis

    Ogata, Y.; Sakuma, Y.; Ohtani, N.; Kotaka, M.

    2002-01-01

    Using three cathode materials, i.e. carbon (C), stainless steel (SUS), and nickel (Ni), tritium was separated from heavy water by electrolysis, and the separation factors were compared. To separate hydrogen isotopes, heavy water was electrolyzed by an electrolysis device with a solid polymer electrode (SPE), which needed no electrolyte additives for electrolysis. The anode was made of 3 mm thickness of a sintered porous titanium plate covered with iridium oxide. The cathode was made of the same thickness of a sintered porous carbon, stainless steel, or nickel plate. Heavy water or light water spiked with tritiated water was electrolyzed 20 A x 60 min with the electrolysis cell temperature at 10, 20 or 30degC, and 15 A x 80 min at 5degC. The produced hydrogen and oxygen gases were recombined using a palladium catalyst with nitrogen gas as a carrier. The activities of the water in the electrolysis cell and of the recombined water were analyzed using a liquid scintillation counter. The apparent D-T separation factor (SF D/T ) and H-T separation factor (SF H/T ) were calculated as quotient the specific activity of the water in the cell divided by that of the recombined water. The electrolysis potential to keep the current 20 A was 2-3 V. The average yields of the recombined water were 95%. At the cell temperature of 20degC, SF D/T (C), SF D/T (SUS), and SF D/T (Ni) were 2.42, 2.17, and 2.05, respectively. At the same temperature, SF H/T (C), SF H/T (SUS), and SF H/T (Ni) were 12.5, 10.8, and 11.8, respectively. The SFs were in agreement with the results in other works. The SFs were changed with the cell temperature. (author)

  16. LARGE-SCALE HYDROGEN PRODUCTION FROM NUCLEAR ENERGY USING HIGH TEMPERATURE ELECTROLYSIS

    O'Brien, James E.

    2010-01-01

    Hydrogen can be produced from water splitting with relatively high efficiency using high-temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high-temperature process heat. When coupled to an advanced high temperature nuclear reactor, the overall thermal-to-hydrogen efficiency for high-temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. Demand for hydrogen is increasing rapidly for refining of increasingly low-grade petroleum resources, such as the Athabasca oil sands and for ammonia-based fertilizer production. Large quantities of hydrogen are also required for carbon-efficient conversion of biomass to liquid fuels. With supplemental nuclear hydrogen, almost all of the carbon in the biomass can be converted to liquid fuels in a nearly carbon-neutral fashion. Ultimately, hydrogen may be employed as a direct transportation fuel in a 'hydrogen economy.' The large quantity of hydrogen that would be required for this concept should be produced without consuming fossil fuels or emitting greenhouse gases. An overview of the high-temperature electrolysis technology will be presented, including basic theory, modeling, and experimental activities. Modeling activities include both computational fluid dynamics and large-scale systems analysis. We have also demonstrated high-temperature electrolysis in our laboratory at the 15 kW scale, achieving a hydrogen production rate in excess of 5500 L/hr.

  17. Probing absorption of deuterium into palladium cathodes during D2O electrolysis with an in situ electrochemical microbalance technique

    Oyama, Noboru; Yamamoto, Nobushige; Hatozaki, Osamu; Ohsaka, Takeo

    1990-01-01

    The in situ observation of the absorption of deuterium (or hydrogen) into the Pd cathode during D 2 O (or H 2 O) electrolysis was made by an electrochemical microbalance technique which is based on the quartz-crystal electrode. The resonant frequency of the Pd-coated quartz-crystal electrode decreased with increasing amount of charge passed during electrolysis, and the frequency change for the D 2 O electrolysis was about twice that for the H 2 O electrolysis. The atom ratios of H/Pd and D/Pd of the H-Pd and D-Pd compounds resulting from the electrolysis were estimated to be 0.59 and 0.57, respectively. (author)

  18. Analysis of Economic Efficiency of Production of Low-Concentrated Sodium Hypochlorite by Direct Electrolysis of Natural Waters

    Fesenko, L. N.; Pchelnikov, I. V.; Fedotov, R. V.

    2017-11-01

    The study presents the economic efficiency of direct electrolysis of natural waters in comparison with the waters artificially prepared by electrolysis of the 3% sodium salt solution. The study used sea water (Black sea water); mineral water (underground water of the Melikhovskaya station, “Ognennaya” hole); brackish water (underground water from the Grushevskaya station of the Aksai district); 3% solution of sodium salt. As a result, the dependences characterizing the direct electrolysis of natural waters with different mineralization, economic, and energy parties are shown. The rational area of the electrolysis for each of the investigated solution is determined. The cost of a kilogram of active chlorine obtained by the direct water electrolysis: Black sea from 17.2 to 18.3 RUB/kg; the Melikhovskaya station “Ognennaya” hole - 14.3 to 15.0 Rubles/kg; 3% solution of NaCl - 30 Rubles./kg; Grushevskogo St. - 63,0-73,0 Rubles/kg.

  19. Wastewater Treatment in Greenland

    Gunnarsdottir, Ragnhildur

    treatment in these regions. However, designing, constructing and operating wastewater collection systems in the Arctic is challenging because of e.g. permafrost conditions, hard rock surfaces, freezing, limited quantity of water and high costs of electricity, fuel and transportation, as well as a settlement...... or water saving toilets. This opens up for co-treatment of organic waste fractions. Freezing and thawing has also been recognised as being a cost-effective wastewater treatment method in cold regions. Thus it was chosen to concentrate on the effect of the mentioned processes, namely freezing, anaerobic...... spreading of nutrients, diseases and potential pollution issues. Due to the above mentioned challenges alternative treatment methods are needed, especially in small and remotely located communities. Decentralized solutions are well suited for Greenland. Ideal solutions should reduce the need for expensive...

  20. Identification of wastewater processes

    Carstensen, Niels Jacob

    The introduction of on-line sensors for monitoring of nutrient salts concentrations on wastewater treatment plants with nutrient removal, opens a wide new area of modelling wastewater processes. The subject of this thesis is the formulation of operational dynamic models based on time series...... of ammonia, nitrate, and phosphate concentrations, which are measured in the aeration tanks of the biological nutrient removal system. The alternatign operation modes of the BIO-DENITRO and BIO-DENIPHO processes are of particular interest. Time series models of the hydraulic and biological processes are very......-known theory of the processes with the significant effects found in data. These models are called grey box models, and they contain rate expressions for the processes of influent load of nutrients, transport of nutrients between the aeration tanks, hydrolysis and growth of biomass, nitrification...

  1. Biodenitrification of industrial wastewater

    Donaldson, T.L.; Walker, J.F. Jr.; Helfrich, M.V.

    1987-01-01

    The Feed Materials Production Center (FMPC), a US Department of Energy facility at Fernald, Ohio, is constructing a fluidized-bed biodenitrification plant based on pilot work conducted at the Oak Ridge National Laboratory (ORNL) in the late 1970s and early 1980s. This plant is designed to treat approximately 600 to 800 L/min of wastewater having a nitrate concentration as high as 10 g/L. The effluent is to contain less than 0.1 g/L of nitrate. Since this new facility is an extrapolation of the ORNL work to significantly larger scale equipment and to actual rather than synthetic wastewater, design verification studies have been performed to reduce uncertainties in the scaleup. The results of these studies are summarized in this report. 7 refs., 1 fig

  2. Parasitological Contamination of Wastewater Irrigated and Raw ...

    Tadesse

    Occurrence of infective stages of intestinal parasites on wastewater- irrigated vegetables ..... reported the health hazards of agricultural reuse of untreated wastewater through detection of .... State of knowledge in land treatment of wastewater.

  3. Microplastic in Danish wastewater

    The objectives of the present study were to evaluate the role of Danish wastewater treatment plants (WWTPs) in the emission of microplastic to the environment in terms of amounts and types of plastic polymers emitted and if possible, to evaluate which sources these plastic polymers could originate...... investigations (Fourier Transformed Infrared Spectroscopy imaging applying a Focal Plane Array). This method allows both determination of the microplastic concentrations in the samples and identification of the type of plastic polymer of each microplastic particle....

  4. Water electrolysis system - H2 and O2 generation. [for spacecraft atmosphere revitalization

    Schubert, F. H.; Lee, M. K.; Davenport, R. J.; Quattrone, P. D.

    1978-01-01

    An oxygen generation system design based on the static feed water electrolysis concept is described. The system is designed to generate 4.20 kg/d of oxygen to satisfy the metabolic needs of a three-person crew, to compensate for spacecraft leakage, and to provide the oxygen required by the electrochemical depolarized CO2 concentrator. The system has a fixed hardware weight of 75 kg, occupies a volume of 0.11 cu m, and requires only 1.1 kw of electrical power. The static feed electrolysis concept is discussed, and experimental data on the high-performance electrode are presented.

  5. Tritium separation from heavy water by electrolysis with solid polymer electrolyte

    Ogata, Y.; Ohtani, N.; Kotaka, M.

    2003-01-01

    A tritium separation from heavy water by electrolysis using a solid polymer electrode layer was specified. The cathode was made of stainless steel or nickel. The electrolysis was performed for 1 hour at 5, 10, 20, and 30 deg C. Using a palladium catalyst, generated hydrogen and oxygen gases were recombined, which was collected with a cold trap. The activities of the samples were measured by a liquid scintillation counter. The apparent tritium separation factors of the heavy and light water at 20 deg C were ∼2 and ∼12, respectively. (author)

  6. Heterogeneous anion conducting membranes based on linear and crosslinked KOH doped polybenzimidazole for alkaline water electrolysis

    Aili, David; Hansen, Martin Kalmar; Renzaho, Richard Fulgence

    2013-01-01

    Polybenzimidazole is a highly hygroscopic polymer that can be doped with aqueous KOH to give a material with high ion conductivity in the 10−2Scm−1 range, which in combination with its low gas permeability makes it an interesting electrolyte material for alkaline water electrolysis. In this study...... on their linear counterpart. The technical feasibility of the membranes was evaluated by the preliminary water electrolysis tests showing performance comparable to that of commercially available cell separators with great potential of further improvement....

  7. Alkaline water electrolysis technology for Space Station regenerative fuel cell energy storage

    Schubert, F. H.; Hoberecht, M. A.; Le, M.

    1986-01-01

    The regenerative fuel cell system (RFCS), designed for application to the Space Station energy storage system, is based on state-of-the-art alkaline electrolyte technology and incorporates a dedicated fuel cell system (FCS) and water electrolysis subsystem (WES). In the present study, emphasis is placed on the WES portion of the RFCS. To ensure RFCS availability for the Space Station, the RFCS Space Station Prototype design was undertaken which included a 46-cell 0.93 cu m static feed water electrolysis module and three integrated mechanical components.

  8. The analysis of energy efficiency in water electrolysis under high temperature and high pressure

    Hourng, L. W.; Tsai, T. T.; Lin, M. Y.

    2017-11-01

    This paper aims to analyze the energy efficiency of water electrolysis under high pressure and high temperature conditions. The effects of temperature and pressure on four different kinds of reaction mechanisms, namely, reversible voltage, activation polarization, ohmic polarization, and concentration polarization, are investigated in details. Results show that the ohmic and concentration over-potentials are increased as temperature is increased, however, the reversible and activation over-potentials are decreased as temperature is increased. Therefore, the net efficiency is enhanced as temperature is increased. The efficiency of water electrolysis at 350°C/100 bars is increased about 17%, compared with that at 80°C/1bar.

  9. Towards a stable ion-solvating polymer electrolyte for advanced alkaline water electrolysis

    Aili, David; Wright, Andrew G.; Kraglund, Mikkel Rykær

    2017-01-01

    Advanced alkaline water electrolysis using ion-solvating polymer membranes as electrolytes represents a new direction in the field of electrochemical hydrogen production. Polybenzimidazole membranes equilibrated in aqueous KOH combine the mechanical robustness and gas-tightness of a polymer...... stability in alkaline environments. The novel electrolytes are extensively characterized with respect to physicochemical and electrochemical properties and the chemical stability is assessed in 0-50 wt% aqueous KOH for more than 6 months at 88 degrees C. In water electrolysis tests using porous 3...

  10. Solid polymer electrolyte water electrolysis preprototype subsystem. [oxygen production for life support systems on space stations

    1979-01-01

    Hardware and controls developed for an electrolysis demonstration unit for use with the life sciences payload program and in NASA's regenerative life support evaluation program are described. Components discussed include: the electrolysis module; power conditioner; phase separator-pump and hydrogen differential regulator; pressure regulation of O2, He, and N2; air-cooled heat exchanger; water accumulator; fluid flow sight gage assembly; catalytic O2/H2 sensor; gas flow sensors; low voltage power supply; 100 Amp DC contactor assembly; and the water purifier design.

  11. Space Station propulsion - Advanced development testing of the water electrolysis concept at MSFC

    Jones, Lee W.; Bagdigian, Deborah R.

    1989-01-01

    The successful demonstration at Marshall Space Flight Center (MSFC) that the water electrolysis concept is sufficiently mature to warrant adopting it as the baseline propulsion design for Space Station Freedom is described. In particular, the test results demonstrated that oxygen/hydrogen thruster, using gaseous propellants, can deliver more than two million lbf-seconds of total impulse at mixture ratios of 3:1 to 8:1 without significant degradation. The results alao demonstrated succcessful end-to-end operation of an integrated water electrolysis propulsion system.

  12. Effects of low voltage electrolysis and freezing on coliform content of contaminated water

    Qazi, J.I.; Saleem, F.

    2003-01-01

    A sewage sample was mixed with drinking water and subjected to low voltage (15V) electrolysis in the presence of 1% NaCl. The prepared sample was also kept in freezer with and without the presence of sodium chloride for 4-hours. Among these treatments the electrolysis proved to kill the coliforms, while the freezing reduced the bacterial content. Antibiotics sensitivity patterns revealed that certain of the coliform strains survived the freezing and thawing shocks. Nature of such surviving bacteria and need to study chemical parameters of electrolyzed water are discussed. (author)

  13. Oxidation of organic pollutants on BDD anodes using modulated current electrolysis

    Panizza, M.; Kapalka, Agnieszka; Comninellis, Ch.

    2008-01-01

    In this paper, a theoretical model is presented for organic pollutants mineralization at high current efficiency (close to 100%) and low energy consumption on boron-doped diamond electrodes. The model is formulated for a perfect mixed electrochemical reactor operated as a batch recirculation system under multiple current steps, in which the applied current is adjusted during the electrolysis to be close to the limiting value. An experimental validation with the anodic oxidation of 3,4,5-trihydroxybenzoic acid is also provided. The results have shown that multiple current steps electrolysis and continuous current control allowed obtaining high oxidation rate and current efficiency

  14. Oxidation of organic pollutants on BDD anodes using modulated current electrolysis

    Panizza, M. [Department of Chemical and Process Engineering, University of Genoa, P.le J.F. Kennedy 1, 16129 Genova (Italy)], E-mail: marco.panizza@unige.it; Kapalka, Agnieszka [Institute of Chemical Sciences and Engineering, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Comninellis, Ch. [Institute of Chemical Sciences and Engineering, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)], E-mail: christos.comninellis@epfl.ch

    2008-01-01

    In this paper, a theoretical model is presented for organic pollutants mineralization at high current efficiency (close to 100%) and low energy consumption on boron-doped diamond electrodes. The model is formulated for a perfect mixed electrochemical reactor operated as a batch recirculation system under multiple current steps, in which the applied current is adjusted during the electrolysis to be close to the limiting value. An experimental validation with the anodic oxidation of 3,4,5-trihydroxybenzoic acid is also provided. The results have shown that multiple current steps electrolysis and continuous current control allowed obtaining high oxidation rate and current efficiency.

  15. Electrolysis of a nitrosyl hexafluoro-molybdate in anhydrous hydrogen fluoride

    Mougin, Jacques

    1972-01-01

    This thesis addresses the field of irradiated fuel reprocessing, and more particularly the study of the formation of molybdenum hexafluoride (MoF_6) by electrolysis of nitrosyl hexafluoro-molybdate (NOMoF_6) in solution in HF. The author presents the conditions of preparation of an electrolysis in anhydrous HF: solvent purification and control, production of a reference electrode, potential-kinetic study of the behaviour of materials selected for the electrode. The author then addresses the actual hydrolysis of the solution of nitrosyl hexafluoro-molybdate [fr

  16. PFP Wastewater Sampling Facility

    Hirzel, D.R.

    1995-01-01

    This test report documents the results obtained while conducting operational testing of the sampling equipment in the 225-WC building, the PFP Wastewater Sampling Facility. The Wastewater Sampling Facility houses equipment to sample and monitor the PFP's liquid effluents before discharging the stream to the 200 Area Treated Effluent Disposal Facility (TEDF). The majority of the streams are not radioactive and discharges from the PFP Heating, Ventilation, and Air Conditioning (HVAC). The streams that might be contaminated are processed through the Low Level Waste Treatment Facility (LLWTF) before discharging to TEDF. The sampling equipment consists of two flow-proportional composite samplers, an ultrasonic flowmeter, pH and conductivity monitors, chart recorder, and associated relays and current isolators to interconnect the equipment to allow proper operation. Data signals from the monitors are received in the 234-5Z Shift Office which contains a chart recorder and alarm annunciator panel. The data signals are also duplicated and sent to the TEDF control room through the Local Control Unit (LCU). Performing the OTP has verified the operability of the PFP wastewater sampling system. This Operability Test Report documents the acceptance of the sampling system for use

  17. Preparation of ceramic-corrosion-cell fillers and application for cyclohexanone industry wastewater treatment in electrobath reactor

    Wu, Suqing; Qi, Yuanfeng; Gao, Yue; Xu, Yunyun; Gao, Fan; Yu, Huan; Lu, Yue; Yue, Qinyan; Li, Jinze

    2011-01-01

    Highlights: ► Dried sewage sludge and scrap iron used as raw materials for sintering ceramics. ► The new media ceramics used as fillers in electrobath of micro-electrolysis. ► Modified micro-electrolysis used in cyclohexanone industry wastewater treatment. ► This modified micro-electrolysis could avoid failure of the electrobath reactor. - Abstract: As new media, ceramic-corrosion-cell fillers (Cathode Ceramic-corrosion-cell Fillers – CCF, and Anode Ceramic-corrosion-cell Fillers – ACF) employed in electrobath were investigated for cyclohexanone industry wastewater treatment. 60.0 wt% of dried sewage sludge and 40.0 wt% of clay, 40.0 wt% of scrap iron and 60.0 wt% of clay were utilized as raw materials for the preparation of raw CCF and ACF, respectively. The raw CCF and ACF were respectively sintered at 400 °C for 20 min in anoxic conditions. The physical properties (bulk density, grain density and water absorption), structural and morphological characters and toxic metal leaching contents were tested. The influences of pH, hydraulic retention time (HRT) and the media height on removal of COD Cr and cyclohexanone were studied. The results showed that the bulk density and grain density of CCF and ACF were 869.0 kg m −3 and 936.3 kg m −3 , 1245.0 kg m −3 and 1420.0 kg m −3 , respectively. The contents of toxic metal (Cu, Zn, Cd, Pb, Cr, Ba, Ni and As) were all below the detection limit. When pH of 3–4, HRT of 6 h and the media height of 60 cm were applied, about 90% of COD cr and cyclohexanone were removed.

  18. Preparation of ceramic-corrosion-cell fillers and application for cyclohexanone industry wastewater treatment in electrobath reactor

    Wu, Suqing; Qi, Yuanfeng; Gao, Yue; Xu, Yunyun; Gao, Fan; Yu, Huan; Lu, Yue [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 250100 Jinan (China); Yue, Qinyan, E-mail: qyyue58@yahoo.com.cn [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 250100 Jinan (China); Li, Jinze [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 250100 Jinan (China)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer Dried sewage sludge and scrap iron used as raw materials for sintering ceramics. Black-Right-Pointing-Pointer The new media ceramics used as fillers in electrobath of micro-electrolysis. Black-Right-Pointing-Pointer Modified micro-electrolysis used in cyclohexanone industry wastewater treatment. Black-Right-Pointing-Pointer This modified micro-electrolysis could avoid failure of the electrobath reactor. - Abstract: As new media, ceramic-corrosion-cell fillers (Cathode Ceramic-corrosion-cell Fillers - CCF, and Anode Ceramic-corrosion-cell Fillers - ACF) employed in electrobath were investigated for cyclohexanone industry wastewater treatment. 60.0 wt% of dried sewage sludge and 40.0 wt% of clay, 40.0 wt% of scrap iron and 60.0 wt% of clay were utilized as raw materials for the preparation of raw CCF and ACF, respectively. The raw CCF and ACF were respectively sintered at 400 Degree-Sign C for 20 min in anoxic conditions. The physical properties (bulk density, grain density and water absorption), structural and morphological characters and toxic metal leaching contents were tested. The influences of pH, hydraulic retention time (HRT) and the media height on removal of COD{sub Cr} and cyclohexanone were studied. The results showed that the bulk density and grain density of CCF and ACF were 869.0 kg m{sup -3} and 936.3 kg m{sup -3}, 1245.0 kg m{sup -3} and 1420.0 kg m{sup -3}, respectively. The contents of toxic metal (Cu, Zn, Cd, Pb, Cr, Ba, Ni and As) were all below the detection limit. When pH of 3-4, HRT of 6 h and the media height of 60 cm were applied, about 90% of COD{sub cr} and cyclohexanone were removed.

  19. TESTING AND PERFORMANCE ANALYSIS OF NASA 5 CM BY 5 CM BI-SUPPORTED SOLID OXIDE ELECTROLYSIS CELLS OPERATED IN BOTH FUEL CELL AND STEAM ELECTROLYSIS MODES

    R. C. O' Brien; J. E. O' Brien; C. M. Stoots; X. Zhang; S. C. Farmer; T. L. Cable; J. A. Setlock

    2011-11-01

    A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

  20. Testing And Performance Analysis Of NASA 5 CM BY 5 CM Bi-Supported Solid Oxide Electrolysis Cells Operated In Both Fuel Cell And Steam Electrolysis Modes

    O'Brien, R.C.; O'Brien, J.E.; Stoots, C.M.; Zhang, X.; Farmer, S.C.; Cable, T.L.; Setlock, J.A.

    2011-01-01

    A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

  1. Advanced wastewater treatment system (SEADS)

    Dunn, J.

    2002-01-01

    'Full text:' This presentation will describe the nature, scope, and findings of a third-party evaluation of a wastewater treatment technology identified as the Advanced Wastewater Treatment System Inc.'s Superior Extended Aerobic Digester System (SEADS). SEADS is an advanced miniaturized wastewater treatment plant that can meet advanced wastewater treatment standards for effluent public reuse. SEADS goes beyond primary and secondary treatment operations to reduce nutrients such as nitrogen and phosphorus, which are typically found in excessive quantities in traditional wastewater treatment effluent. The objective of this evaluation will be to verify the performance and reliability of the SEADS to treat wastewater from a variety of sources, including domestic wastewater and commercial industrial wastewater. SEADS utilizes remote telemetry equipment to achieve added reliability and reduces monitoring costs as compared to many package wastewater treatment plants. The evaluation process will be overseen and coordinated by the Environmental Technology Evaluation Center (EvTEC), a program of the Civil Engineering Research Foundation (CERF), the research and technology transfer arm of the American Society of Civil Engineers (ASCE). EvTEC is a pilot program evaluating innovative environmental technologies under the US Environmental Protection Agency's (USEPA) Environmental Technology Verification (ETV) Program. Among other performance issues, the SEADS technology evaluation will address its ability to treat low flows-from remote individual and clustered housing applications, and individual commercial applications in lieu of a main station conventional wastewater treatment plant. The unneeded reliance on particular soil types for percolation and the improved effluent water quality over septic systems alone look to make these types of package treatment plants a viable option for rural communities, small farms, and other low-flow remote settings. Added benefits to be examined

  2. Optimizing TOC and COD removal for the biodiesel wastewater by electrocoagulation

    Tanattı, N. Pınar; Şengil, İ. Ayhan; Özdemir, Abdil

    2018-05-01

    In this study, the chemical oxygen demand (COD) and the total organic carbon content (TOC) in biodiesel wastewater iron and aluminum electrodes arranged in a bipolar position. In the EC of the biodiesel wastewater, the effects of the supporting electrolyte, initial pH, electrolysis time and current density were examined. The results showed that the majority of the pollutants in the biodiesel wastewater were effectively removed when the iron or aluminum electrodes were used as a sacrificial anode. The highest COD and TOC removal efficiencies were successfully obtained with the iron electrode. COD removal efficiencies are 91.74 and 90.94% for iron and aluminum electrode, respectively. In the same way, TOC removal efficiencies were obtained as 91.79 and 91.98% for the iron and aluminum electrodes, respectively, at initial pH of 6, the current density of 0.3226 mA/cm2, NaCl concentration 1 g/L and 1 min of operating time.

  3. Combination of electrochemical processes with membrane bioreactors for wastewater treatment and fouling control: A review

    Benny Marie B. Ensano

    2016-08-01

    Full Text Available This paper provides a critical review about the integration of electrochemical processes into membrane bioreactors (MBR in order to understand the influence of these processes on wastewater treatment performance and membrane fouling control. The integration can be realized either in an internal or an external configuration. Electrically enhanced membrane bioreactors or electro membrane bioreactors (eMBRs combine biodegradation, electrochemical and membrane filtration processes into one system providing higher effluent quality as compared to conventional MBRs and activated sludge plants. Furthermore, electrochemical processes, such as electrocoagulation, electrophoresis and electroosmosis, help to mitigate deposition of foulants into the membrane and enhance sludge dewaterability by controlling the morphological properties and mobility of the colloidal particles and bulk liquid. Intermittent application of minute electric field has proven to reduce energy consumption and operational cost as well as minimize the negative effect of direct current field on microbial activity which are some of the main concerns in eMBR technology. The present review discusses important design considerations of eMBR, its advantages as well as its applications to different types of wastewater. It also presents several challenges that need to be addressed for future development of this hybrid technology which include treatment of high strength industrial wastewater and removal of emerging contaminants, optimization study, cost benefit analysis and the possible combination with microbial electrolysis cell for biohydrogen production.

  4. Electrochemical treatment of domestic wastewater using boron-doped diamond and nanostructured amorphous carbon electrodes.

    Daghrir, Rimeh; Drogui, Patrick; Tshibangu, Joel; Delegan, Nazar; El Khakani, My Ali

    2014-05-01

    The performance of the electrochemical oxidation process for efficient treatment of domestic wastewater loaded with organic matter was studied. The process was firstly evaluated in terms of its capability of producing an oxidant agent (H2O2) using amorphous carbon (or carbon felt) as cathode, whereas Ti/BDD electrode was used as anode. Relatively high concentrations of H2O2 (0.064 mM) was produced after 90 min of electrolysis time, at 4.0 A of current intensity and using amorphous carbon at the cathode. Factorial design and central composite design methodologies were successively used to define the optimal operating conditions to reach maximum removal of chemical oxygen demand (COD) and color. Current intensity and electrolysis time were found to influence the removal of COD and color. The contribution of current intensity on the removal of COD and color was around 59.1 and 58.8%, respectively, whereas the contribution of treatment time on the removal of COD and color was around 23.2 and 22.9%, respectively. The electrochemical treatment applied under 3.0 A of current intensity, during 120 min of electrolysis time and using Ti/BDD as anode, was found to be the optimal operating condition in terms of cost/effectiveness. Under these optimal conditions, the average removal rates of COD and color were 78.9 ± 2 and 85.5 ± 2 %, whereas 70% of total organic carbon removal was achieved.

  5. ANALYSIS OF A POSSIBLE REDUCTION IN ENERGY CONSUMPTION IN WATER ELECTROLYSIS REACTION

    Aurel George POPESCU

    2013-05-01

    Full Text Available It was experimentally observed that the electrolysis reaction continues a short period of time - time torelax c - after the cell power supply is interrupted. This paper presents an analysis of transient phenomenaoccurring and pr opose technical solutions

  6. The electrolysis of water: An actuation principle for MEMS with a big opportunity

    Rusu, C.R.; Neagu, Cristina; Jansen, Henricus V.; Gardeniers, Johannes G.E.; Elwenspoek, Michael Curt

    In this paper the theory of water electrolysis in a closed electrochemical cell, that contains two electrodes, an electrolyte and a pressure sensor is described. From the leakage and electrochemical experiments done with this macrocell it is possible to obtain information about the applicability of

  7. Nanoporous materials for reducing the over potential of creating hydrogen by water electrolysis

    Anderson, Marc A.; Leonard, Kevin C.

    2016-06-14

    Disclosed is an electrolyzer including an electrode including a nanoporous oxide-coated conducting material. Also disclosed is a method of producing a gas through electrolysis by contacting an aqueous solution with an electrode connected to an electrical power source, wherein the electrode includes a nanoporous oxide-coated conducting material.

  8. Model-supported characterization of a PEM water electrolysis cell for the effect of compression

    Frensch, Steffen Henrik; Olesen, Anders Christian; Simon Araya, Samuel

    2018-01-01

    This paper investigates the influence of the cell compression of a PEM water electrolysis cell. A small single cell is therefore electrochemically analyzed by means of polarization behavior and impedance spectroscopy throughout a range of currents (0.01 A cm−2 to 2.0 A cm−2) at two temperatures (60...

  9. Syntrophic interactions drive the hydrogen production from glucose at low temperature in microbial electrolysis cells

    Lu, Lu; Xing, Defeng; Ren, Nanqi; Logan, Bruce E.

    2012-01-01

    H2 can be obtained from glucose by fermentation at mesophilic temperatures, but here we demonstrate that hydrogen can also be obtained from glucose at low temperatures using microbial electrolysis cells (MECs). H2 was produced from glucose at 4°C

  10. High hydrogen production from glycerol or glucose by electrohydrogenesis using microbial electrolysis cells

    Selembo, Priscilla A.; Perez, Joe M.; Lloyd, Wallis A.; Logan, Bruce E.

    2009-01-01

    The use of glycerol for hydrogen gas production was examined via electrohydrogenesis using microbial electrolysis cells (MECs). A hydrogen yield of 3.9 mol-H2/mol was obtained using glycerol, which is higher than that possible by fermentation

  11. Comparative costs of hydrogen produced from photovoltaic electrolysis and from photoelectrochemical processes

    Block, D.L.

    1998-01-01

    The need for hydrogen produced from renewable energy sources is the key element to the world's large-scale usage of hydrogen and to the hydrogen economy envisioned by the World Hydrogen Energy Association. Renewables-produced hydrogen is also the most technically difficult problem to be solved. Hydrogen will never achieve large-scale usage until it can be competitively produced from renewable energy. One of the important questions that has to be addressed is: What are the economics of present and expected future technologies that will be used to produce hydrogen from renewables? The objective of this study is to give an answer to this question by determining the cost of hydrogen (in U.S.$/MBtu) from competing renewable production technologies. It should be noted that the costs and efficiencies assumed in this paper are assumptions of the author, and that the values are expected to be achieved after additional research on photoelectrochemical process technologies. The cost analysis performed is for three types of hydrogen (H 2 ) produced from five different types of renewable processes: photovoltaic (PV) electrolysis, three photoelectrochemical (PEC) processes and higher temperature electrolysis (HTE). The costs and efficiencies for PV, PEC and HTE processes are established for present day, and for expected costs and efficiencies 10 years into the future. A second objective of this analysis is to set base case costs of PV electrolysis. For any other renewable process, the costs for PV electrolysis, which is existing technology, sets the numbers which the other processes must better. (author)

  12. Diagnosis of a cathode-supported solid oxide electrolysis cell by electrochemical impedance spectroscopy

    Nechache, A.; Mansuy, A.; Petitjean, M.; Mougin, J.; Mauvy, F.; Boukamp, Bernard A.; Cassir, M.; Ringuede, A.

    2016-01-01

    High-temperature electrolysis (HTSE) is a quite recent topic where most of the studies are focused on performance measurements and degradation observations, mainly achieved by polarization curve. However, it mainly leads to the overall cell behaviour. To get more specific knowledge on the operation

  13. The importance of OH − transport through anion exchange membrane in microbial electrolysis cells

    Ye, Yaoli; Logan, Bruce

    2018-01-01

    In two-chamber microbial electrolysis cells (MECs) with anion exchange membranes (AEMs), a phosphate buffer solution (PBS) is typically used to avoid increases in catholyte pH as Nernst equation calculations indicate that high pHs adversely impact

  14. Optimization of catholyte concentration and anolyte pHs in two chamber microbial electrolysis cells

    Nam, Joo-Youn; Logan, Bruce E.

    2012-01-01

    The hydrogen production rate in a microbial electrolysis cell (MEC) using a non-buffered saline catholyte (NaCl) can be optimized through proper control of the initial anolyte pH and catholyte NaCl concentration. The highest hydrogen yield of 3

  15. Durable SOC stacks for production of hydrogen and synthesis gas by high temperature electrolysis

    Ebbesen, Sune Dalgaard; Høgh, Jens Valdemar Thorvald; Nielsen, Karsten Agersted

    2011-01-01

    . The degradation of the electrolysis cells was found to be influenced by the adsorption of impurities from the applied inlet gases, whereas the application of chromium containing interconnect plates and glass sealings do not seem to influence the durability when operated at 850 °C. Cleaning the inlet gases...

  16. The impact of anode acclimation strategy on microbial electrolysis cell treating hydrogen fermentation effluent

    Li, Xiaohu; Zhang, Ruizhe; Qian, Yawei

    2017-01-01

    The impact of different anode acclimation methods for enhancing hydrogen production in microbial electrolysis cell (MEC) was investigated in this study. The anodes were first acclimated in microbial fuel cells using acetate, butyrate and corn stalk fermentation effluent (CSFE) as substrate before...

  17. Thermodynamic analysis of the efficiency of high-temperature steam electrolysis system for hydrogen production

    Mingyi, Liu; Bo, Yu; Jingming, Xu; Jing, Chen

    High-temperature steam electrolysis (HTSE), a reversible process of solid oxide fuel cell (SOFC) in principle, is a promising method for highly efficient large-scale hydrogen production. In our study, the overall efficiency of the HTSE system was calculated through electrochemical and thermodynamic analysis. A thermodynamic model in regards to the efficiency of the HTSE system was established and the quantitative effects of three key parameters, electrical efficiency (η el), electrolysis efficiency (η es), and thermal efficiency (η th) on the overall efficiency (η overall) of the HTSE system were investigated. Results showed that the contribution of η el, η es, η th to the overall efficiency were about 70%, 22%, and 8%, respectively. As temperatures increased from 500 °C to 1000 °C, the effect of η el on η overall decreased gradually and the η es effect remained almost constant, while the η th effect increased gradually. The overall efficiency of the high-temperature gas-cooled reactor (HTGR) coupled with the HTSE system under different conditions was also calculated. With the increase of electrical, electrolysis, and thermal efficiency, the overall efficiencies were anticipated to increase from 33% to a maximum of 59% at 1000 °C, which is over two times higher than that of the conventional alkaline water electrolysis.

  18. Hydrogen Production Performance of a 10-Cell Planar Solid-Oxide Electrolysis Stack

    James O'Brien; Carl Stoots; Steve Herring; J. Hartvigsen

    2005-01-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900 C. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte supported, with scandia-stabilized zirconia electrolytes (∼140 (micro)m thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1-0.6), gas flow rates (1000-4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 100 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate

  19. Contact glow discharge electrolysis: its origin, plasma diagnostics and non-faradaic chemical effects

    Sen Gupta, Susanta K

    2015-01-01

    Contact glow discharge electrolysis (CGDE) also termed plasma electrolysis is a novel electrolysis where a stable sheath of light emitting plasma develops around an electrode immersed well inside a relatively high-conductivity liquid electrolyte during normal electrolysis (NE) at several hundred volts. The phenomenon may develop in dc-, pulsed dc-, ac- as well as RF-driven electrolyses. The chemical effects of CGDE are remarkably non-faradaic in respect to the nature of the products as well as their yields. The article traces comprehensively the progress made in studies of CGDE in aqueous and non-aqueous solutions since 1844 and reviews the developments in the understanding of its origin, light emission, plasma state and non-faradaic effects leading to the elucidation of detailed mechanism of the origin of CGDE on the basis of the onset of hydrodynamic instabilities in local vaporization of the solvent near the working electrode during NE, and that of highly non-faradaic effects of CGDE based on a model of two reaction zones located within the electrode plasma and at the plasma–liquid interface producing solvent derived radicals at high local concentrations. Keeping in view the recent surge of interest in varied applications of CGDE, the article is appended with highlights of these applications across synthetic chemistry, waste water treatment, electrosurgical devices, nanoparticle fabrications, surface engineering and micro-machining. (topical review)

  20. High Temperature Alkaline Electrolysis Cells with Metal Foam Based Gas Diffusion Electrodes

    Chatzichristodoulou, Christodoulos; Allebrod, Frank; Mogensen, Mogens Bjerg

    2016-01-01

    Alkaline electrolysis cells operating at 250°C and 40 bar are able to convert electrical energy into hydrogen at very high efficiencies and power densities. In the present work we demonstrate the application of a PTFE hydrophobic network and Ag nanowires as oxygen evolution electrocatalyst...

  1. Single exponential decay waveform; a synergistic combination of electroporation and electrolysis (E2 for tissue ablation

    Nina Klein

    2017-04-01

    Full Text Available Background Electrolytic ablation and electroporation based ablation are minimally invasive, non-thermal surgical technologies that employ electrical currents and electric fields to ablate undesirable cells in a volume of tissue. In this study, we explore the attributes of a new tissue ablation technology that simultaneously delivers a synergistic combination of electroporation and electrolysis (E2. Method A new device that delivers a controlled dose of electroporation field and electrolysis currents in the form of a single exponential decay waveform (EDW was applied to the pig liver, and the effect of various parameters on the extent of tissue ablation was examined with histology. Results Histological analysis shows that E2 delivered as EDW can produce tissue ablation in volumes of clinical significance, using electrical and temporal parameters which, if used in electroporation or electrolysis separately, cannot ablate the tissue. Discussion The E2 combination has advantages over the three basic technologies of non-thermal ablation: electrolytic ablation, electrochemical ablation (reversible electroporation with injection of drugs and irreversible electroporation. E2 ablates clinically relevant volumes of tissue in a shorter period of time than electrolysis and electroporation, without the need to inject drugs as in reversible electroporation or use paralyzing anesthesia as in irreversible electroporation.

  2. Analysis and Countermeasures of Wind Power Accommodation by Aluminum Electrolysis Pot-Lines in China

    Zhang, Hongliang; Ran, Ling; He, Guixiong; Wang, Zhenyu; Li, Jie

    2017-10-01

    The unit energy consumption and its price have become the main obstacles for the future development of the aluminum electrolysis industry in China. Meanwhile, wind power is widely being abandoned because of its instability. In this study, a novel idea for wind power accommodation is proposed to achieve a win-win situation: the idea is for nearby aluminum electrolysis plants to absorb the wind power. The features of the wind power distribution and aluminum electrolysis industry are first summarized, and the concept of wind power accommodation by the aluminum industry is introduced. Then, based on the characteristics of aluminum reduction cells, the key problems, including the bus-bar status, thermal balance, and magnetohydrodynamics instabilities, are analyzed. In addition, a whole accommodation implementation plan for wind power by aluminum reduction is introduced to explain the theoretical value of accommodation, evaluation of the reduction cells, and the industrial experiment scheme. A numerical simulation of a typical scenario proves that there is large accommodation potential for the aluminum reduction cells. Aluminum electrolysis can accommodate wind power and remain stable under the proper technique and accommodation scheme, which will provide promising benefits for the aluminum plant and the wind energy plant.

  3. Treating soil-washing fluids polluted with oxyfluorfen by sono-electrolysis with diamond anodes.

    Vieira Dos Santos, E; Sáez, C; Cañizares, P; Martínez-Huitle, C A; Rodrigo, M A

    2017-01-01

    This works is focused on the treatment by sono-electrolysis of the liquid effluents produced during the Surfactant-Aided Soil-Washing (SASW) of soils spiked with herbicide oxyfluorfen. Results show that this combined technology is very efficient and attains the complete mineralization of the waste, regardless of the surfactant/soil radio applied in the SASW process (which is the main parameter of the soil remediation process and leads to very different wastes). Both the surfactant and the herbicide are completely degraded, even when single electrolysis is used; and only two intermediates are detected by HPLC in very low concentrations. Conversely, the efficiency of single sonolysis approach, for the oxidation of pollutant, is very low and just small changes in the herbicides and surfactant concentrations are observed during the tests carried out. Sono-electrolysis with diamond electrodes achieved higher degradation rates than those obtained by single sonolysis and/or single electrolysis with diamond anodes. A key role of sulfate is developed, when it is released after the electrochemical degradation of surfactant. The efficient catalytic effect observed which can be explained by the anodic formation of persulfate and the later, a sono-activation is attained to produce highly efficient sulfate radicals. The effect of irradiating US is more importantly observed in the pesticide than in the surfactant, in agreement with the well-known behavior of these radicals which are known to oxidize more efficiently aromatic compounds than aliphatic species. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Microbial electrolysis contribution to anaerobic digestion of waste activated sludge, leading to accelerated methane production

    Liu, Wenzong; Cai, Weiwei; Guo, Zechong

    2016-01-01

    Methane production rate (MPR) in waste activated sludge (WAS) digestion processes is typically limitedby the initial steps of complex organic matter degradation, leading to a limited MPR due to sludgefermentation speed of solid particles. In this study, a novel microbial electrolysis AD reactor (ME...

  5. Present status of r and d on hydrogen production by high temperature electrolysis of steam

    Hino, Ryutaro; Aita, Hideki; Sekita, Kenji; Haga, Katsuhiro; Miyamoto, Yoshiaki; Iwata, Tomo-o.

    1995-08-01

    In JAERI, design and R and D works on hydrogen production process have been conducted for connecting to the HTTR under construction at the Oarai Establishment of the JAERI as the nuclear heat utilization system. As for a hydrogen production process by high-temperature electrolysis of steam, laboratory-scale experiments have been conducted using a practical electrolysis tube with 12 cells connected in series. Hydrogen was produced at a maximum density of 44 Nml/cm 2 h at 950degC, and know-how of operational procedures and operational experience have been also accumulated. Then, a self-supporting planar electrolysis cell was fabricated in order to improve hydrogen production performance. In the preliminary test with the planar cell, hydrogen has been produced continuously at a maximum density of 36 Nml/cm 2 h at lower electrolysis temperature of 850degC. This report presents typical test results mentioned above, a review of previous studies conducted in the world and R and D items required for connecting to the HTTR. (author)

  6. Wastewater treatment models

    Gernaey, Krist; Sin, Gürkan

    2011-01-01

    description of biological phosphorus removal, physicalchemical processes, hydraulics and settling tanks. For attached growth systems, biofilm models have progressed from analytical steady-state models to more complex 2D/3D dynamic numerical models. Plant-wide modeling is set to advance further the practice......The state-of-the-art level reached in modeling wastewater treatment plants (WWTPs) is reported. For suspended growth systems, WWTP models have evolved from simple description of biological removal of organic carbon and nitrogen in aeration tanks (ASM1 in 1987) to more advanced levels including...

  7. Wastewater Treatment Models

    Gernaey, Krist; Sin, Gürkan

    2008-01-01

    description of biological phosphorus removal, physical–chemical processes, hydraulics, and settling tanks. For attached growth systems, biofilm models have progressed from analytical steady-state models to more complex 2-D/3-D dynamic numerical models. Plant-wide modeling is set to advance further......The state-of-the-art level reached in modeling wastewater treatment plants (WWTPs) is reported. For suspended growth systems, WWTP models have evolved from simple description of biological removal of organic carbon and nitrogen in aeration tanks (ASM1 in 1987) to more advanced levels including...

  8. EC treatment for reuse of tissue paper wastewater: aspects that affect energy consumption.

    Terrazas, Eduardo; Vázquez, Armando; Briones, Roberto; Lázaro, Isabel; Rodríguez, Israel

    2010-09-15

    The need for more rational use of water also calls for more efficient usage. An example is the production of tissue paper, where large amounts of water are discharged into the drain because its turbidity does not allow for recirculation. While this is a serious problem, even worse is the fact that the quality of such wastewater makes it difficult not only to recirculate but also to discharge due to environmental law restrictions. In this paper, electrocoagulation is proposed as a suitable technology to meet standards of water discharge, and even better, as a treatment option for removal of turbidity. Since energy consumption has been a drawback for EC applications, relevant aspects that contribute to increase it such as cell voltage and current density have been reviewed. For this purpose a systematic micro-electrolysis study combined with macro-electrolysis experiments have provided evidence that shows it is possible to achieve a turbidity removal of 92% with an energy consumption of 0.68 kWh/m(3). Thus, the results presented in this paper support the use of EC to obtain water of acceptable quality for reuse in the tissue paper industry. Copyright 2010 Elsevier B.V. All rights reserved.

  9. Application of novel catalytic-ceramic-filler in a coupled system for long-chain dicarboxylic acids manufacturing wastewater treatment.

    Wu, Suqing; Qi, Yuanfeng; Fan, Chunzhen; He, Shengbing; Dai, Bibo; Huang, Jungchen; Zhou, Weili; Gao, Lei

    2016-02-01

    To gain systematic technology for long-chain dicarboxylic acids (LDCA) manufacturing wastewater treatment, catalytic micro-electrolysis (CME) coupling with adsorption-biodegradation sludge (AB) process was studied. Firstly, novel catalytic-ceramic-filler was prepared from scrap iron, clay and copper sulfate solution and packed in the CME reactor. To remove residual n-alkane and LDCA, the CME reactor was utilized for LDCA wastewater pretreatment. The results revealed that about 94% of n-alkane, 98% of LDCA and 84% of chemical oxygen demand (COD) were removed by the aerated CME reactor at the optimum hydraulic retention time (HRT) of 3.0 h. In this process, catalysis from Cu and montmorillonites played an important role in improving the contaminants removal. Secondly, to remove residual COD in the wastewater, AB process was designed for the secondary biological treatment, about 90% of the influent COD could be removed by biosorption, bio-flocculation and biodegradation effects. Finally, the effluent COD (about 150 mg L(-1)) discharged from the coupled CME-AB system met the requirement of the national discharged standard (COD ≤ 300 mg L(-1)). All of these results suggest that the coupled CME-AB system is a promising technology due to its high-efficient performance, and has the potential to be applied for the real LDCA wastewater treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Bioelectrochemical systems (BES) for sustainable energy production and product recovery from organic wastes and industrial wastewaters

    Pant, Deepak; Singh, Anoop; Van Bogaert, Gilbert

    2012-01-01

    Bioelectrochemical systems (BESs) are unique systems capable of converting the chemical energy of organic waste including low-strength wastewaters and lignocellulosic biomass into electricity or hydrogen/chemical products in microbial fuel cells (MFCs) or microbial electrolysis cells (MECs......) respectively, or other products formed at the cathode by an electrochemical reduction process. As compared to conventional fuel cells, BESs operate under relatively mild conditions, use a wide variety of organic substrates and mostly do not use expensive precious metals as catalysts. The recently discovered...... use of BES for product synthesis via microbial electrosynthesis have greatly expanded the horizon for these systems. Newer concepts in application as well as development of alternative materials for electrodes, separators, and catalysts, along with innovative designs have made BESs very promising...

  11. Historical variations in the stable isotope composition of mercury in a sediment core from a riverine lake: Effects of dams, pulp and paper mill wastes, and mercury from a chlor-alkali plant

    Jackson, Togwell A.

    2016-01-01

    The Wabigoon River (Ontario, Canada) was affected by dams starting in 1898 and was polluted with pulp and paper mill wastes starting in 1913 and mercury from a chlor-alkali plant from 1962 to 1975. A dated sediment core from a riverine lake was analysed to investigate resultant changes in the biogeochemistry of mercury as revealed by variations in mercury isotope ratios and sediment chemistry. A total mercury maximum formed by the mercury pollution coincided with minimums in the δ-values of the 198 Hg/ 202 Hg, 199 Hg/ 202 Hg, 200 Hg/ 202 Hg, and 201 Hg/ 202 Hg ratios, and the δ-values decreased in the order δ 201 Hg > δ 200 Hg > δ 199 Hg > δ 198 Hg. Thus, mass-dependent fractionation caused depletion in lighter isotopes, implying evaporation of Hg(0) and pollution of the atmosphere as well as the river-lake system. Concurrently, mass-independent fractionation caused 199 Hg enrichment, possibly reflecting an independently documented upsurge in methylmercury production, and 201 Hg depletion, suggesting removal of methylmercury with anomalously high 201 Hg/ 199 Hg ratios by aquatic organisms and accumulation of 201 Hg-depleted inorganic Hg(II) in sediments. The δ 201 Hg/δ 199 Hg ratio rose abruptly when mercury pollution began, reflecting the resultant increase in methylmercury production, and remained high but gradually declined as the pollution abated, paralleling trends shown by methylmercury in aquatic organisms. The δ 201 Hg/δ 199 Hg ratio of pre-1962 background mercury increased ca. 1898 and ca. 1913–1929, suggesting accelerated methylmercury production due to stimulation of microbial activities by the damming of the river and the input of pulp and paper mill wastes, respectively. Other variations were linked to economic and technological factors that affected pulp and paper manufacture. - Highlights: • A core from a lake polluted by Hg and organic wastes was analysed for Hg isotopes. • Hg from a chlor-alkali plant was depleted in lighter

  12. Neutralization of wastewater from nitrite passivation

    Pawlowski, L.; Mientki, B.; Wasag, H.

    1982-01-01

    A method for neutralization of wastewater formed in nitrite passivation has been presented. The method consists of introducing urea into wastewater and acidifying it with sulphuric acid. Wastewater is neutralized with lime. After clarification, wastewater can be drained outside the plant

  13. Treatment of oilfield produced water using Fe/C micro-electrolysis assisted by zero-valent copper and zero-valent aluminium.

    Zhang, Qi

    2015-01-01

    In this study, the Fe/Cu/C and Fe/Al/C inner micro-electrolysis systems were used to treat actual oilfield produced water to evaluate the feasibility of the technology. Effects of reaction time, pH value, the dosage of metals and activated carbon, and Fe:C mass ratio on the treatment efficiency of wastewater were studied. The results showed that the optimum conditions were reaction time 120 min, initial solution pH 4.0, Fe dosage 13.3 g/L, activated carbon dosage 6.7 g/L, Cu dosage 2.0 g/L or Al dosage 1.0 g/L. Under the optimum conditions, the removal efficiencies of chemical oxygen demand (COD) were 39.3%, 49.7% and 52.6% in the Fe/C, Fe/Cu/C and Fe/Al/C processes, respectively. Meanwhile, the ratio of five-day biochemical oxygen demand to COD was raised from 0.18 to above 0.35, which created favourable conditions for the subsequent biological treatment. All these led to an easy maintenance and low operational cost.

  14. Factors affecting reuse of wastewater

    Haraszti, L

    1981-01-01

    Changing the quality of circulating water, raising the effectiveness of sedimentation, examples of biological treatment of wastewater are presented. The necessity of continuing the studies on biological treatment of wastewater is demonstrated. It is considered useful to define the importance of KhPK and BP5 in each case. During biological treatment in ponds, to define the relation BPK5:N:P, research on conditions for nutrient removal must be done. To do this, as well as decrease the significance of KhPK, a mathematical model for defining the effectiveness of biological treatment of wastewater and consequently their reuse must be developed.

  15. The Interconversion of Electrical and Chemical Energy: The Electrolysis of Water and the Hydrogen-Oxygen Fuel Cell.

    Roffia, Sergio; And Others

    1988-01-01

    Discusses some of the drawbacks of using a demonstration of the electrolysis of water to illustrate the interconversion between electrical and chemical energy. Illustrates a simple apparatus allowing demonstration of this concept while overcoming these drawbacks. (CW)

  16. Integrated hydrogen production process from cellulose by combining dark fermentation, microbial fuel cells, and a microbial electrolysis cell

    Wang, Aijie; Sun, Dan; Cao, Guangli; Wang, Haoyu; Ren, Nanqi; Wu, Wei-Min; Logan, Bruce E.

    2011-01-01

    Hydrogen gas production from cellulose was investigated using an integrated hydrogen production process consisting of a dark fermentation reactor and microbial fuel cells (MFCs) as power sources for a microbial electrolysis cell (MEC). Two MFCs

  17. Multiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionate

    Rao, Hari Ananda; Katuri, Krishna; Gorron, Eduardo; Logan, Bruce E.; Saikaly, Pascal

    2016-01-01

    Microbial electrolysis cells (MECs) provide a viable approach for bioenergy generation from fermentable substrates such as propionate. However, the paths of electron flow during propionate oxidation in the anode of MECs are unknown. Here, the paths

  18. Studies of water electrolysis in polymeric membrane cells; Estudos de eletrolise aquosa em celulas de membrana polimerica

    Oliveira-Silva, M.A.; Linardi, M.; Saliba-Silva, A.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Celulas a Combustivel e Hidrogenio

    2010-07-01

    Hydrogen represents great opportunity to be a substitute for fossil fuels in the future. Water as a renewable source of hydrogen is of great interest, since it is abundant and can decompose, producing only pure H{sub 2} and O{sub 2}. This decomposition of water can be accomplished by processes such as electrolysis, thermal decomposition and thermochemical cycles. The membrane electrolysis has been proposed as a viable process for hydrogen production using thermal and electrical energy derived from nuclear energy or any renewable source like solar energy. In this work, within the context of optimization of the electrolysis process, it is intended to develop a mathematical model that can simulate and assist in parameterization of the electrolysis performed by polymer membrane electrolytic cell. The experimental process to produce hydrogen via the cell membrane, aims to optimize the amount of gas produced using renewable energy with non-carbogenic causing no harm by producing gases deleterious to the environment. (author)

  19. Preliminary study of the electrolysis of aluminum sulfide in molten salts

    Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

    1983-02-01

    A preliminary laboratory-scale study of the electrolysis of aluminum sulfide in molten salts investigated the (1) solubility of Al/sub 2/S/sub 3/ in molten salts, (2) electrochemical behavior of Al/sub 2/S/sub 3/, and (3) electrolysis of Al/sub 2/S/sub 3/ with the determination of current efficiency as a function of current density. The solubility measurements show that MgCl/sub 2/-NaCl-KCl eutectic electrolyte at 1023 K can dissolve up to 3.3 mol % sulfide. The molar ratio of sulfur to aluminum in the eutectic is about one, which suggests that some sulfur remains undissolved, probably in the form of MgS. The experimental data and thermodynamic calculations suggest that Al/sub 2/S/sub 3/ dissolves in the eutectic to form AlS/sup +/ species in solution. Addition of AlCl/sub 3/ to the eutectic enhances the solubility of Al/sub 2/S/sub 3/; the solubility increases with increasing AlCl/sub 3/ concentration. The electrode reaction mechanism for the electrolysis of Al/sub 2/S/sub 3/ was elucidated by using linear sweep voltammetry. The cathodic reduction of aluminum-ion-containing species to aluminum proceeds by a reversible, diffusion-controlled, three-electron reaction. The anodic reaction involves the two-electron discharge of sulfide-ion-containing species, followed by the fast dimerization of sulfur atoms to S/sub 2/. Electrolysis experiments show that Al/sub 2/S/sub 3/ dissolved in molten MgCl/sub 2/-NaCl-KCl eutectic or in eutectic containing AlCl/sub 3/ can be electrolyzed to produce aluminum and sulfur. In the eutectic at 1023 K, the electrolysis can be conducted up to about 300 mA/cm/sup 2/ for the saturation solubility of Al/sub 2/S/sub 3/. Although these preliminary results are promising, additional studies are needed to elucidate many critical operating parameters before the technical potential of the electrolysis can be accurately assessed. 20 figures, 18 tables.

  20. Hydrogen production through high-temperature electrolysis in a solid oxide cell

    Herring, J.St.; Lessing, P.; O'Brien, J.E.; Stoots, C.; Hartvigsen, J.; Elangovan, S.

    2004-01-01

    An experimental research programme is being conducted by the INEEL and Ceramatec, Inc., to test the high-temperature, electrolytic production of hydrogen from steam using a solid oxide cell. The research team is designing and testing solid oxide cells for operation in the electrolysis mode, producing hydrogen rising a high-temperature heat and electrical energy. The high-temperature heat and the electrical power would be supplied simultaneously by a high-temperature nuclear reactor. Operation at high temperature reduces the electrical energy requirement for electrolysis and also increases the thermal efficiency of the power-generating cycle. The high-temperature electrolysis process will utilize heat from a specialized secondary loop carrying a steam/hydrogen mixture. It is expected that, through the combination of a high-temperature reactor and high-temperature electrolysis, the process will achieve an overall thermal conversion efficiency of 40 to 50%o while avoiding the challenging chemistry and corrosion issues associated with the thermochemical processes. Planar solid oxide cell technology is being utilised because it has the best potential for high efficiency due to minimized voltage and current losses. These losses also decrease with increasing temperature. Initial testing has determined the performance of single 'button' cells. Subsequent testing will investigate the performance of multiple-cell stacks operating in the electrolysis mode. Testing is being performed both at Ceramatec and at INEEL. The first cells to be tested were single cells based on existing materials and fabrication technology developed at Ceramatec for production of solid oxide fuel cells. These cells use a relatively thick (∼ 175 μm) electrolyte of yttria- or scandia-stabilised zirconia, with nickel-zirconia cermet anodes and strontium-doped lanthanum manganite cathodes. Additional custom cells with lanthanum gallate electrolyte have been developed and tested. Results to date have

  1. Monitoring and assessment of mercury pollution in the vicinity of a chloralkali plant. III. Concentration and genotoxicity of mercury in the industrial effluent and contaminated water of Rushikulya estuary, India.

    Panda, K K; Lenka, M; Panda, B B

    1992-01-01

    Aquatic mercury pollution of the Rushikulya estuary in the vicinity of the chloralkali plant at Ganjam, India was monitored over a period from October 1987 to May 1989. The concentrations of aquatic mercury in the water samples taken from the effluent channel and from different sites along the course of the estuary covering a distance of 2 km were periodically recorded and ranged from 0 to 0.5 mg/l. The bioconcentration and genotoxicity of aquatic mercury in the samples were assessed by the Allium micronucleus (MNC) assay. The frequency of cells with MNC was highly correlated not only with bioconcentrated mercury (root mercury) but also with the levels of aquatic mercury. The threshold assessment values such as effective concentration fifty (EC50) for root growth, lowest effective concentration tested (LECT), and highest ineffective concentration tested (HICT) for induction of MNC in Allium MNC assay for the present aquatic industrial mercury were determined to be 0.14, 0.06 and 0.02 mg/l, respectively.

  2. Al/sub 2/S/sub 3/ preparation and use in electrolysis process for aluminum production

    Hsu, C.C.; Loutfy, R.O.; Yao, N.P.

    A continuous process for producing aluminum sulfide and for electrolyzing the aluminum sulfide to form metallic aluminum in which the aluminum sulfide is produced from aluminum oxide and COS or CS/sub 2/ in the presence of a chloride melt which also serves as the electrolysis bath. Circulation between the reactor and electrolysis cell is carried out to maintain the desired concentration of aluminum sulfide in the bath.

  3. Engineered nanoparticles in wastewater and wastewater sludge - Evidence and impacts

    Brar, Satinder K.; Verma, Mausam; Tyagi, R.D.; Surampalli, R.Y.

    2010-01-01

    Nanotechnology has widespread application in agricultural, environmental and industrial sectors ranging from fabrication of molecular assemblies to microbial array chips. Despite the booming application of nanotechnology, there have been serious implications which are coming into light in the recent years within different environmental compartments, namely air, water and soil and its likely impact on the human health. Health and environmental effects of common metals and materials are well-known, however, when the metals and materials take the form of nanoparticles - consequential hazards based on shape and size are yet to be explored. The nanoparticles released from different nanomaterials used in our household and industrial commodities find their way through waste disposal routes into the wastewater treatment facilities and end up in wastewater sludge. Further escape of these nanoparticles into the effluent will contaminate the aquatic and soil environment. Hence, an understanding of the presence, behavior and impact of these nanoparticles in wastewater and wastewater sludge is necessary and timely. Despite the lack of sufficient literature, the present review attempts to link various compartmentalization aspects of the nanoparticles, their physical properties and toxicity in wastewater and wastewater sludge through simile drawn from other environmental streams.

  4. Wastewater treatment by flotation

    F.P. Puget

    2000-12-01

    Full Text Available This work deals with the performance analysis of a separation set-up characterized by the ejector-hydrocyclone association, applied in the treatment of a synthetic dairy wastewater effluent. The results obtained were compared with the results from a flotation column (cylindrical body of a hydrocyclone operated both batch and continuously. As far as the experimental set-up studied in this work and the operating conditions imposed to the process, it is possible to reach a 25% decrease in the total effluent chemical oxygen demand (COD. This corresponds approximately to 60% of the COD of the material in suspension. The best results are obtained for ratios air flow rate-feed flow rate (Qair/Q L greater then 0.15 and for ratios underflow rate-overflow rate (Qu/Qo lower than 1.0.

  5. Modelling of wastewater systems

    Bechmann, Henrik

    to analyze and quantify the effect of the Aeration Tank Settling (ATS) operating mode, which is used during rain events. Furthermore, the model is used to propose a control algorithm for the phase lengths during ATS operation. The models are mainly formulated as state space model in continuous time......In this thesis, models of pollution fluxes in the inlet to 2 Danish wastewater treatment plants (WWTPs) as well as of suspended solids (SS) concentrations in the aeration tanks of an alternating WWTP and in the effluent from the aeration tanks are developed. The latter model is furthermore used...... at modelling the fluxes in terms of the multiple correlation coefficient R2. The model of the SS concentrations in the aeration tanks of an alternating WWTP as well as in the effluent from the aeration tanks is a mass balance model based on measurements of SS in one aeration tank and in the common outlet...

  6. Electrochemical disinfection of coliform and Escherichia coli for drinking water treatment by electrolysis method using carbon as an electrode

    Riyanto; Agustiningsih, W. A.

    2018-04-01

    Disinfection of coliform and E. Coli in water has been performed by electrolysis using carbon electrodes. Carbon electrodes were used as an anode and cathode with a purity of 98.31% based on SEM-EDS analysis. This study was conducted using electrolysis powered by electric field using carbon electrode as the anode and cathode. Electrolysis method was carried out using variations of time (30, 60, 90, 120 minutes at a voltage of 5 V) and voltage (5, 10, 15, 20 V for 30 minutes) to determine the effect of the disinfection of the bacteria. The results showed the number of coliform and E. coli in water before and after electrolysis was 190 and 22 MPN/100 mL, respectively. The standards quality of drinking water No. 492/Menkes/Per/IV/2010 requires the zero content of coliform and E. Coli. Electrolysis with the variation of time and potential can reduce the number of coliforms and E. Coli but was not in accordance with the standards. The effect of hydrogen peroxide (H2O2) to the electrochemical disinfection was determined using UV-Vis spectrophotometer. The levels of H2O2 formed increased as soon after the duration of electrolysis voltage but was not a significant influence to the mortality of coliform and E.coli.

  7. Degradation of 3,3'-iminobis-propanenitrile in aqueous solution by Fe(0)/GAC micro-electrolysis system.

    Lai, Bo; Zhou, Yuexi; Yang, Ping; Yang, Jinghui; Wang, Juling

    2013-01-01

    The degradation of 3,3'-iminobis-propanenitrile was investigated using the Fe(0)/GAC micro-electrolysis system. Effects of influent pH value, Fe(0)/GAC ratio and granular activated carbon (GAC) adsorption on the removal efficiency of the pollutant were studied in the Fe(0)/GAC micro-electrolysis system. The degradation of 3,3'-iminobis-propanenitrile was affected by influent pH, and a decrease of the influent pH values from 8.0 to 4.0 led to the increase of degradation efficiency. Granular activated carbon was added as cathode to form macroscopic galvanic cells between Fe(0) and GAC and enhance the current efficiency of the Fe(0)/GAC micro-electrolysis system. The GAC could only adsorb the pollutant and provide buffer capacity for the Fe(0)/GAC micro-electrolysis system, and the macroscopic galvanic cells of the Fe(0)/GAC micro-electrolysis system played a leading role in degradation of 3,3'-iminobis-propanenitrile. With the analysis of the degradation products with GC-MS, possible reaction pathway for the degradation of 3,3'-iminobis-propanenitrile by the Fe(0)/GAC micro-electrolysis system was suggested. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Feasibility of Using an Electrolysis Cell for Quantification of the Electrolytic Products of Water from Gravimetric Measurement.

    Melaku, Samuel; Gebeyehu, Zewdu; Dabke, Rajeev B

    2018-01-01

    A gravimetric method for the quantitative assessment of the products of electrolysis of water is presented. In this approach, the electrolysis cell was directly powered by 9 V batteries. Prior to electrolysis, a known amount of potassium hydrogen phthalate (KHP) was added to the cathode compartment, and an excess amount of KHCO 3 was added to the anode compartment electrolyte. During electrolysis, cathode and anode compartments produced OH - (aq) and H + (aq) ions, respectively. Electrolytically produced OH - (aq) neutralized the KHP, and the completion of this neutralization was detected by a visual indicator color change. Electrolytically produced H + (aq) reacted with HCO 3 - (aq) liberating CO 2 (g) from the anode compartment. Concurrent liberation of H 2 (g) and O 2 (g) at the cathode and anode, respectively, resulted in a decrease in the mass of the cell. Mass of the electrolysis cell was monitored. Liberation of CO 2 (g) resulted in a pronounced effect of a decrease in mass. Experimentally determined decrease in mass (53.7 g/Faraday) agreed with that predicted from Faraday's laws of electrolysis (53.0 g/Faraday). The efficacy of the cell was tested to quantify the acid content in household vinegar samples. Accurate results were obtained for vinegar analysis with a precision better than 5% in most cases. The cell offers the advantages of coulometric method and additionally simplifies the circuitry by eliminating the use of a constant current power source or a coulometer.

  9. Energy-Efficient and Environmentally Friendly Solid Oxide Membrane Electrolysis Process for Magnesium Oxide Reduction: Experiment and Modeling

    Guan, Xiaofei; Pal, Uday B.; Powell, Adam C.

    2014-06-01

    This paper reports a solid oxide membrane (SOM) electrolysis experiment using an LSM(La0.8Sr0.2MnO3-δ)-Inconel inert anode current collector for production of magnesium and oxygen directly from magnesium oxide at 1423 K (1150 °C). The electrochemical performance of the SOM cell was evaluated by means of various electrochemical techniques including electrochemical impedance spectroscopy, potentiodynamic scan, and electrolysis. Electronic transference numbers of the flux were measured to assess the magnesium dissolution in the flux during SOM electrolysis. The effects of magnesium solubility in the flux on the current efficiency and the SOM stability during electrolysis are discussed. An inverse correlation between the electronic transference number of the flux and the current efficiency of the SOM electrolysis was observed. Based on the experimental results, a new equivalent circuit of the SOM electrolysis process is presented. A general electrochemical polarization model of SOM process for magnesium and oxygen gas production is developed, and the maximum allowable applied potential to avoid zirconia dissociation is calculated as well. The modeling results suggest that a high electronic resistance of the flux and a relatively low electronic resistance of SOM are required to achieve membrane stability, high current efficiency, and high production rates of magnesium and oxygen.

  10. Electrochemical Treatment of Wastewater Containing Mixed Reactive Dyes Using Carbon Nanotube Modified Cathode Electrodes

    Nader Djafarzadeh

    2016-11-01

    Full Text Available Nowadays, advanced electrochemical oxidation processes are promising methods for the treatment of wastewaters containing organic dyes. One of these methods is the Electro-Fenton (EF technique in which an electrical current is applied to the cathode and anode electrodes to promote electrochemical reactions that generate hydroxyl radicals which mineralize organic pollutants and remove them from wastewater. To carry out the Electro-Fenton process iIn this work, the carbon paper (CP electrode was initially modified with carbon nanotubes (CNT to produce the CP-CNT electrode which was used as the cathode to remove a mixture of organic dyestuff (containing Reactive Blue 69, Reactive Red 195, and Reactive Yellow 84 from wastewaters. Comparison of the two types of cathode electrodes (i.e., CNT and the modified CP-CNT showed that the CP-CNT outperformed the CP electrode. The EF process was employed to treat 500 ml of a mixture of dyes (50 mg/L of each dye containing sodium soulfate and Fe+3 ions. The results revealed that the highest color removal efficiency was achieved when a current of 300 mA was applied for 210 min. COD measurments were used to calculate the effective current and power consumption. It was found that the 300 mA current applied over a period of 210 min yielded the highest effective current and the lowest power consumption. The amount of dyes mineralized by the EF process in the dye solution indicated that 78% of the initial COD had been removed under the above conditions. It may be concluded that the Electro-Fenton process can be successfully used for the treatment of wastewaters containing mixtures of dye pollutants. Cathode electrode type, electrical current, and electrolysis duration were identified as the parameters affecting the process.

  11. Electrochemical oxidation of COD from real textile wastewaters: Kinetic study and energy consumption.

    Zou, Jiaxiu; Peng, Xiaolan; Li, Miao; Xiong, Ying; Wang, Bing; Dong, Faqin; Wang, Bin

    2017-03-01

    In the present study, the electrochemical oxidation of real wastewaters discharged by textile industry was carried out using a boron-doped diamond (BDD) anode. The effect of operational variables, such as applied current density (20-100 mA·cm -2 ), NaCl concentration added to the real wastewaters (0-3 g·L -1 ), and pH value (2.0-10.0), on the kinetics of COD oxidation and on the energy consumption was carefully investigated. The obtained experimental results could be well matched with a proposed kinetic model, in which the indirect oxidation mediated by electrogenerated strong oxidants would be described through a pseudo-first-order kinetic constant k. Values of k exhibited a linear increase with increasing applied current density and decreasing pH value, and an exponential increase with NaCl concentration. Furthermore, high oxidation kinetics resulted in low specific energy consumption, but this conclusion was not suitable to the results obtained under different applied current density. Under the optimum operational conditions, it only took 3 h to complete remove the COD in the real textile wastewaters and the specific energy consumption could be as low as 11.12 kWh·kg -1  COD. The obtained results, low energy consumption and short electrolysis time, allowed to conclude that the electrochemical oxidation based on BDD anodes would have practical industrial application for the treatment of real textile wastewater. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A review on wastewater disinfection

    Mohammad Mehdi Amin; Hassan Hashemi; Amir Mohammadi Bovini; Yung Tse Hung

    2013-01-01

    Changes in regulations and development of new technologies have affected the selection of alternative for treated wastewater disinfection. Disinfection is the last barrier of wastewater reclamation process to protect ecosystem safety and human health. Driving forces include water scarcity and drinking water supply, irrigation, rapid industrialization, using reclaimed water, source protection, overpopulation, and environmental protection. The safe operation of water reuse depends on effluent d...

  13. Conversion of laser energy to chemical energy by the photoassisted electrolysis of water

    Wrighton, M. S.

    1976-01-01

    Ultraviolet irradiation of the n-type semiconductor TiO2 crystal electrode of an aqueous electrochemical cell evolves O2 at the TiO2 electrode and H2 at the Pt electrode. The gases are typically evolved in a 2:1 (H2:O2) volume ratio. The photoassisted reaction seems to require applied voltages, but values as low as 0.25 V do allow the photoassisted electrolysis to proceed. Prolonged irradiation in either acid or base evolves the gaseous products in amounts which clearly demonstrate that the reaction is catalytic with respect to the TiO2. The wavelength response of the TiO2 and the correlation of product yield and current are reported. The results support the claim that TiO2 is a true photoassistance agent for the electrolysis of water. Minimum optical storage efficiencies of the order of 1 percent can be achieved by the production of H2.

  14. Development of Non-Platinum Catalysts for Intermediate Temperature Water Electrolysis

    Nikiforov, Aleksey Valerievich; Petrushina, Irina Michailovna; Bjerrum, Niels J.

    2014-01-01

    Water electrolysis is recognized as an efficient energy storage (in the form of hydrogen) supplement in renewable energy production. However, industrial alkaline water electrolyzers are rather ineffective and space requiring for a commercial use in connection with energy storage. The most effective...... modern water electrolyzers are based on polymeric proton-conducting membrane electrolytes (PEM), e.g. Nafion®, a perfluorocarbon-sulfonic acid polymer. These electrolyzers work at temperatures up to around 80 °C, and, in extreme cases, up to 130-140 °C. The most developed PEM electrolyzers...... as electrolytes for the intermediate temperature applications, such as CsHSO4, KHSO45. The most successful systems have been developed with CsH2PO4 (solid acid fuel cells (SAFCs) and Sn0.9In0.1P2O7 electrolytes6,7. While developing materials for the promising medium temperature electrolysis systems...

  15. Test results of six-month test of two water electrolysis systems

    Mills, E. S.; Wells, G. W.

    1972-01-01

    The two water electrolysis systems used in the NASA space station simulation 90-day manned test of a regenerative life support system were refurbished as required and subjected to 26-weeks of testing. The two electrolysis units are both promising systems for oxygen and hydrogen generation and both needed extensive long-term testing to evaluate the performance of the respective cell design and provide guidance for further development. Testing was conducted to evaluate performance in terms of current, pressure, variable oxygen demands, and orbital simulation. An automatic monitoring system was used to record, monitor and printout performance data at one minute, ten minute or one-hour intervals. Performance data is presented for each day of system operation for each module used during the day. Failures are analyzed, remedial action taken to eliminate problems is discussed and recommendations for redesign for future space applications are stated.

  16. Hydrogen from renewable energy - Photovoltaic/water electrolysis as an exemplary approach

    Sprafka, R. J.; Tison, R. R.; Escher, W. J. D.

    1984-01-01

    A feasibility study has been conducted for a NASA Kennedy Space Center liquid hydrogen/liquid oxygen production facility using solar cell arrays as the power source for electrolysis. The 100 MW output of the facility would be split into 67.6 and 32 MW portions for electrolysis and liquefaction, respectively. The solar cell array would cover 1.65 sq miles, and would be made up of 249 modular 400-kW arrays. Hydrogen and oxygen are generated at either dispersed or centralized water electrolyzers. The yearly hydrogen output is projected to be 5.76 million lbs, with 8 times that much oxygen; these fuel volumes can support approximately 18 Space Shuttle launches/year.

  17. Bioelectrohydrogenesis and inhibition of methanogenic activity in microbial electrolysis cells - A review.

    Karthikeyan, Rengasamy; Cheng, Ka Yu; Selvam, Ammaiyappan; Bose, Arpita; Wong, Jonathan W C

    2017-11-01

    Microbial electrolysis cells (MECs) are a promising technology for biological hydrogen production. Compared to abiotic water electrolysis, a much lower electrical voltage (~0.2V) is required for hydrogen production in MECs. It is also an attractive waste treatment technology as a variety of biodegradable substances can be used as the process feedstock. Underpinning this technology is a recently discovered bioelectrochemical pathway known as "bioelectrohydrogenesis". However, little is known about the mechanism of this pathway, and numerous hurdles are yet to be addressed to maximize hydrogen yield and purity. Here, we review various aspects including reactor configurations, microorganisms, substrates, electrode materials, and inhibitors of methanogenesis in order to improve hydrogen generation in MECs. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Summary of the Mol electrolysis cell test program in the CRL tritium laboratory

    Miller, J.M.; Keyes, R.J.

    1996-01-01

    The development of electrolysis technology for highly tritiated water at the Studiecentrum voor Kernenergie/Centre d'Etude de l'Energie Nucleaire (SCK/CEN), Mol, Belgium, focused on A Low Inventory Capillary Electrolyser (ALICE). The key characteristic of ALICE is its low liquid inventory, a key feature for the radio-toxicity of tritiated water. A program to test this electrolytic cell design with highly tritiated water in the Chalk River Tritium Laboratory was initiated in 1988 and extended through to early 1995. The activities conducted at CRL and associated with the experimental program-design, installation, licensing and commissioning activities- are described in this report along with the results of the test program conducted on the experimental system with non-tritiated heavy water. The installation in the CRL Tritium Laboratory consisted of three main sections: the electrolysis section, the tritium storage and supply section, and the recombination section. 16 figs., 2 tabs., 10 refs

  19. Carbon Deposition during CO2 Electrolysis in Ni-Based Solid-Oxide-Cell Electrodes

    Skafte, Theis Løye; Graves, Christopher R.; Blennow, P.

    2015-01-01

    . Electrochemical impedance spectroscopy in both H2/H2O and CO/CO2 revealed an increase in resistance of the fuel electrode after each CO2 electrolysis current-voltage curve, indicating possible carbon deposition. The difference in partial oxygen pressure between inlet and outlet was analyzed to verify carbon...... in detail. In an attempt to mitigate the degradation due to carbon deposition, the Ni-YSZ electrode was infiltrated with a gadolinium doped ceria (CGO) solution. Initial results indicate that the coking tolerance was not enhanced, but it is still unclear whether infiltrated cells degrade less. However......, infiltrated cells display a significant performance enhancement before coking, especially under electrolysis current. The investigation thus indicated carbon formation in the Ni containing fuel electrode before the thermodynamically calculated threshold for average measurements of the cell was reached...

  20. Microstructure characterisation of solid oxide electrolysis cells operated at high current density

    Bowen, Jacob R.; Bentzen, Janet Jonna; Chen, Ming

    degradation of cell components in relation to the loss of electrochemical performance specific to the mode of operation. Thus descriptive microstructure characterization methods are required in combination with electrochemical characterization methods to decipher degradation mechanisms. In the present work......High temperature solid oxide cells can be operated either as fuel cells or electrolysis cells for efficient power generation or production of hydrogen from steam or synthesis gas (H2 + CO) from steam and CO2 respectively. When operated under harsh conditions, they often exhibit microstructural...... quantified using the mean linear intercept method as a function of current density and correlated to increases in serial resistance. The above structural changes are then compared in terms of electrode degradation observed during the co-electrolysis of steam and CO2 at current densities up to -1.5 A cm-2...

  1. Experiments on a ceramic electrolysis cell and a palladium diffuser at the tritium systems test assembly

    Konishi, Satoshi; Yoshida, Hiroshi; Ohno, Hideo; Naruse, Yuji; Coffin, D.O.; Walthers, C.R.; Binning, K.E.

    1985-01-01

    A ceramic electrolysis cell and a palladium diffuser are developed in Japan and is tested with tritium in Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory, in order to confirm the feasibility as possible upgrades for the fuel cleanup system (PCU). The ceramic electrolysis cell made of stabilized zirconia was operated at 630 0 C for an extended period with a mixture of 3% T 2 O in He carrier gas in the circulation system with oxidizing catalyst bed. The palladium diffuser was tested with circulated pure tritium gas at 280 0 C to verify the compatibility of the alloy with tritium, since the 3 He produced in the metal could cause a degradation. The isotopic effects were also measured for both devices

  2. Thermodynamic analysis of synthetic hydrocarbon fuel production in pressurized solid oxide electrolysis cells

    Sun, Xiufu; Chen, Ming; Jensen, Søren Højgaard

    2012-01-01

    A promising way to store wind and solar electricity is by electrolysis of H2O and CO2 using solid oxide electrolysis cells (SOECs) to produce synthetic hydrocarbon fuels that can be used in existing fuel infrastructure. Pressurized operation decreases the cell internal resistance and enables...... improved system efficiency, potentially lowering the fuel production cost significantly. In this paper, we present a thermodynamic analysis of synthetic methane and dimethyl ether (DME) production using pressurized SOECs, in order to determine feasible operating conditions for producing the desired......, and outlet gas composition. For methane production, low temperature and high pressure operation could improve the system efficiency, but might lead to a higher capital cost. For DME production, high pressure SOEC operation necessitates higher operating temperature in order to avoid carbon formation at higher...

  3. Development of solid electrolytes for water electrolysis at intermediate temperatures. Task 3 report; Annual report

    Linkous, C.A.; Anderson, R.; Kopitzke, R.W.

    1995-12-01

    This project is an attempt to synthesize and fabricate proton exchange membranes for hydrogen production via water electrolysis that can take advantage of the better kinetic and thermodynamic conditions that exist at higher temperatures. Current PEM technology is limited to the 125--150 C range. Based on previous work evaluating thermohydrolytic stability, some 5 families of polymers were chosen as viable candidates: polyether ketones, polyether sulfones, fluorinated polyimides, polybenzimidazoles, and polyphenyl quinoxalines. Several of these have been converted into ionomers via sulfonation and fashioned into membranes for evaluation. In particular, the sulfonated polyetheretherketone, or SPEEK, was tested for water uptake, thermo-conductimetric analysis, and performance as the solid electrolyte material in an electrolysis cell. Results comparable to commercial perfluorocarbon sulfonates were obtained.

  4. Experiment Plan of High Temperature Steam and Carbon dioxide Co-electrolysis for Synthetic Gas Production

    Yoon, Duk-Joo; Ko, Jae-Hwa

    2008-01-01

    Currently, Solid oxide fuel cells (SOFC) come into the spotlight in the middle of the energy technologies of the future for highly effective conversion of fossil fuels into electricity without carbon dioxide emission. The SOFC is a reversible cell. By applying electrical power to the cell, which is solid oxide electrolysis cell (SOEC), it is possible to produce synthetic gas (syngas) from high temperature steam and carbon dioxide. The produced syngas (hydrogen and carbon monoxide) can be used for synthetic fuels. This SOEC technology can use high temperature from VHTRs for high efficiency. This paper describes KEPRI's experiment plan of high temperature steam and carbon co-electrolysis for syngas production using SOEC technology

  5. Hydrogen Generation by Koh-Ethanol Plasma Electrolysis Using Double Compartement Reactor

    Saksono, Nelson; Sasiang, Johannes; Dewi Rosalina, Chandra; Budikania, Trisutanti

    2018-03-01

    This study has successfully investigated the generation of hydrogen using double compartment reactor with plasma electrolysis process. Double compartment reactor is designed to achieve high discharged voltage, high concentration, and also reduce the energy consumption. The experimental results showed the use of double compartment reactor increased the productivity ratio 90 times higher compared to Faraday electrolysis process. The highest hydrogen production obtained is 26.50 mmol/min while the energy consumption can reach up 1.71 kJ/mmol H2 at 0.01 M KOH solution. It was shown that KOH concentration, addition of ethanol, cathode depth, and temperature have important effects on hydrogen production, energy consumption, and process efficiency.

  6. Clinical estimation of sup(99m)Tc-labeled compounds produced by electrolysis

    Watanabe, Katsuji; Kawahira, Kenjiro; Kamoi, Itsuma; Morita, Kazunori

    1974-01-01

    Scintigrams were made using sup(99m)Tc-Sn-colloid, sup(99m)Tc-pyrophosphate, sup(99m)Tc-EDTA and sup(99m)Tc-albumin prepared by electrolysis, and a clinical evaluation was attempted. No side effects were recognized in 228 cases, therefore the object of this study could be attained. Future study was thought to be necessary because the pictures were somewhat indistinct. However, each sup(99m)Tc-labeled compound could be prepared very easily and was extremely convenient for daily use. sup(99m)Tc- is a nuclide which has many advantages for use with scintigrams. More useful sup(99m)Tc-labeled compounds will be explored in the future and is expected that electrolysis has many possibilities for use in the preparation of sup(99m)Tc-labeled compounds. (Tsunoda, M.)

  7. Electrode materials for hydrobromic acid electrolysis in Texas Instruments' solar chemical converter

    Luttmer, J.D.; Konrad, D.; Trachtenberg, I.

    1985-05-01

    Texas Instruments has developed a solar chemical converter (SCC) which converts solar energy into chemical energy via the electrolysis of hydrobromic acid. Various materials were evaluated as anodes and cathodes for the electrolysis of the acid. Emphasis was placed on obtaining low overvoltage electrodes with good long-term stability. Sputtered platinum-iridium thin films were identified as the best choice as the cathode material, and sputtered iridium and iridium oxide thin films were identified as the best choice as anode materials. Electrochemical measurements indicate that low overvoltage losses are encountered on these materials at operating current densitities in the SCC. Accelerated corrosion tests of the materials predict acceptable electrode stability for 20 years in an environment representative of onthe-roof service.

  8. Life Time Performance Characterization of Solid Oxide Electrolysis Cells for Hydrogen Production

    Sun, Xiufu; Chen, Ming; Liu, Yi-Lin

    2015-01-01

    . In this work, long-term durability of Ni/yttria stabilized zirconia (YSZ) supported planar SOECs were investigated at 800 oC for electrolysis of steam. The cells, which represent the state-of-the-art SOEC technology at Technical University of Denmark (DTU), have a Ni/YSZ support and active fuel electrode......, OCV) to -1.25 A/cm2. Detailed electrochemical and post-mortem characterizations were further conducted in order to clarify the cell or electrode degradation mechanisms. The cells show stable performance, with a steady-state degradation rate of up to 2 %/1000 h for electrolysis tests with current......Globally the amount of electricity generated from renewable energy sources such as wind or solar energy is increasing. To integrate high amount of fluctuating renewable energy into the existing energy grid, efficient and cost competitive conversion of electricity into other kinds of energy carriers...

  9. Hydrogen Through Water Electrolysis and Biomass Gasification for Application in Fuel Cells

    Y. Kirosa

    2017-03-01

    Full Text Available Hydrogen is considered to be one of the most promising green energy carrier in the energy storage and conversion scenario. Although it is abundant on Earth in the form of compounds, its occurrence in free form is extremely low. Thus, it has to be produced by reforming processes, steam reforming (SR, partial oxidation (POX and auto-thermal reforming (ATR mainly from fossil fuels for high throughput with high energy requirements, pyrolysis of biomass and electrolysis. Electrolysis is brought about by passing electric current though two electrodes to evolve water into its constituent parts, viz. hydrogen and oxygen, respectively. Hydrogen produced by non-noble metal catalysts for both anode and cathode is therefore cost-effective and can be integrated into fuel cells for direct chemical energy conversion into electrical energy electricity, thus meeting the sustainable and renewable use with low carbon footprint.

  10. Selection of combined water electrolysis and resistojet propulsion for Space Station Freedom

    Schmidt, George R.

    1988-01-01

    An analytical rationale is presented for the configuration of the NASA Space Station's two-element propulsion system, and attention is given to the cost benefits accruing to this system over the Space Station's service life. The principal system element uses gaseous oxygen and hydrogen obtained through water electrolysis to furnish attitude control, backup attitude control, and contingency maneuvering. The secondary element uses resistojets to augment Space Station reboost through the acceleration of waste gases in the direction opposite the Station's flight path.

  11. Study of deuterium charging in palladium by electrolysis of heavy water

    De Ninno, A.; Violante, V.

    1992-01-01

    A mathematical model supported by a numerical computer code with distributed parameters was developed in order to describe the evolution of the deuteron concentration profile inside a Pd cathode under pulsed electrolysis. A delocalized gas picture was used when the deuterons exceeded the ratio, x=0.8, in Pd-D compounds. Several boundary conditions were taken into account. A good agreement was found between the system evolution and experimental data

  12. Feasibility Analysis of Liquefying Oxygen Generated from Water Electrolysis Units on Lunar Surface

    Jeng, Frank F.

    2009-01-01

    Concepts for liquefying oxygen (O2) generated from water electrolysis subsystems on the Lunar surface were explored. Concepts for O2 liquefaction units capable of generating 1.38 lb/hr (0.63 kg/hr) liquid oxygen (LOX) were developed. Heat and mass balance calculations for the liquefaction concepts were conducted. Stream properties, duties of radiators, heat exchangers and compressors for the selected concepts were calculated and compared.

  13. Surface topography of a palladium cathode after electrolysis in heavy water

    Silver, D.S.; Dash, J.; Keefe, P.S.

    1993-01-01

    Electrolysis was performed with a palladium cathode and an electrolyte containing both hydrogen and deuterium ions. The cathode bends toward the anode during this process. Examination of both the concave and the convex surfaces with the scanning electron microscope, scanning tunneling microscope, and atomic force microscope shows unusual surface characteristics. Rimmed craters with faceted crystals inside and multitextural surfaces were observed on an electrolyzed palladium cathode but not on palladium that has not been electrolyzed. 9 refs., 9 figs

  14. Electrolysis Bubble Noise in Small-Scale Tests of a Seawater MHD thruster

    1990-09-01

    SECURITY CLAS&ICATION AUTHORITY I DISTRIBUTION/ AVAILABILIT Y OF REPORT 2b. DECLSIFICATIONJDOWNGRADING SCHEDULE Approved for public release...to those which might occur in an undersea MI-D-powered vesseL The electrolysis of sea water at current densities up to 0.3 A/cn, ’produced broad-band...3 Test Equipm eni ...................................................... 5 Water Table Facility and Flow Channels

  15. Research Progress of Hydrogen Production fromOrganic Wastes in Microbial Electrolysis Cell(MEC

    YU Yin-sheng

    2015-08-01

    Full Text Available Microbial electrolysis cell(MECtechnology as an emerging technology, has achieved the target of hydrogen production from different substrates such as waste water, forestry wastes, activated sludge by simultaneous enzymolysis and fermentation, which can effectively improve the efficiency of resource utilization. This paper described the working principle of MEC and analyzed these factors influencing the process of hydrogen production from organic waste in MEC.

  16. Understanding the processes governing performance and durability of solid oxide electrolysis cells

    Ebbesen, Sune Dalgaard; Sun, Xiufu; Mogensen, Mogens Bjerg

    2015-01-01

    Operation of a Ni–YSZ electrode supported Solid Oxide Cell (SOC) was studied in both fuel cell mode (FC-mode) and electrolysis cell mode (EC-mode) in mixtures of H2O/H2, CO2/CO, H2O/H2O/CO2/CO at 750 °C, 800 °C and 850 °C. Although the SOCs are reversible, the polarisation characterisation shows ...

  17. Recovery of fission products from waste solutions utilizing controlled cathodic potential electrolysis

    Carlin, W.W.; Darlington, W.B.

    1975-01-01

    Fission products, e.g., palladium, rhodium and technetium, are recovered from aqueous waste solutions thereof, e.g., aged Purex alkaline waste solutions. The metal values from the waste solutions are extracted by ion exchange techniques. The metals adsorbed by the ion exchange resin are eluted and selectively recovered by controlled cathodic potential electrolysis. The metal values deposited on the cathode are recovered and, if desired, further purified

  18. Conceptual study of on orbit production of cryogenic propellants by water electrolysis

    Moran, Matthew E.

    1991-01-01

    The feasibility is assessed of producing cryogenic propellants on orbit by water electrolysis in support of NASA's proposed Space Exploration Initiative (SEI) missions. Using this method, water launched into low earth orbit (LEO) would be split into gaseous hydrogen and oxygen by electrolysis in an orbiting propellant processor spacecraft. The resulting gases would then be liquified and stored in cryogenic tanks. Supplying liquid hydrogen and oxygen fuel to space vehicles by this technique has some possible advantages over conventional methods. The potential benefits are derived from the characteristics of water as a payload, and include reduced ground handling and launch risk, denser packaging, and reduced tankage and piping requirements. A conceptual design of a water processor was generated based on related previous studies, and contemporary or near term technologies required. Extensive development efforts would be required to adapt the various subsystems needed for the propellant processor for use in space. Based on the cumulative results, propellant production by on orbit water electrolysis for support of SEI missions is not recommended.

  19. Chemically durable polymer electrolytes for solid-state alkaline water electrolysis

    Park, Eun Joo; Capuano, Christopher B.; Ayers, Katherine E.; Bae, Chulsung

    2018-01-01

    Generation of high purity hydrogen using electrochemical splitting of water is one of the most promising methods for sustainable fuel production. The materials to be used as solid-state electrolytes for alkaline water electrolyzer require high thermochemical stability against hydroxide ion attack in alkaline environment during the operation of electrolysis. In this study, two quaternary ammonium-tethered aromatic polymers were synthesized and investigated for anion exchange membrane (AEM)-based alkaline water electrolyzer. The membranes properties including ion exchange capacity (IEC), water uptake, swelling degree, and anion conductivity were studied. The membranes composed of all C-C bond polymer backbones and flexible side chain terminated by cation head groups exhibited remarkably good chemical stability by maintaining structural integrity in 1 M NaOH solution at 95 °C for 60 days. Initial electrochemical performance and steady-state operation performance were evaluated, and both membranes showed a good stabilization of the cell voltage during the steady-state operation at the constant current density at 200 mA/cm2. Although both membranes in current form require improvement in mechanical stability to afford better durability in electrolysis operation, the next generation AEMs based on this report could lead to potentially viable AEM candidates which can provide high electrolysis performance under alkaline operating condition.

  20. Technetium electrodeposition from aqueous formate solutions: electrolysis kinetics and material balance study

    Maslennikov, A.; Peretroukhine, V.

    1998-01-01

    The kinetics of the Tc electrodeposition and the material balance of potentiostatic electrolysis of formate buffer solutions (pH = 1.79-8.5) containing 5*10 -4 - 1*10 -2 M Tc(VII) at graphite cathode has been studied. The deposition of Tc from the solution was found to become possible at E x *y H 2 O (x ≤ 2, 1.5 cath. ) towards more negative values and the augmentation of the electrolyte surface/volume ratio (S/V) were found to increase the yield of the electrolysis and the rate of the electrodeposition process. A maximum technetium recovery of 92-95% has been observed in the electrolysis of neutral HCOONa solutions (pH = 6.0-7.5, μ = 1.0) containing up to 5*10 -1 M Tc(VII) at potentials of the graphite cathode E 2 . A starting Tc concentration in the solution of [Tc(VII)] > 5 *10 -1 M and the presence of more than 0.05 M NO 3 - in the electrolyte were found to suppress the recovery of technetium from the solution. (orig.)

  1. Preconceptual design of hyfire. A fusion driven high temperature electrolysis plant

    Varljen, T.C.; Chi, J.W.H.; Karbowski, J.S.

    1983-01-01

    Brookhaven National Laboratory has been engaged in a scoping study to investigate the potential merits of coupling a fusion reactor with a high temperature blanket to a high temperature electrolysis (HTE) process to produce hydrogen and oxygen. Westinghouse is assisting this study in the areas of systems design integration, plasma engineering, balance of plant design and electrolyzer technology. The aim of the work done in the past year has been to focus on a reference design point for the plant, which has been designated HYFIRE. In prior work, the STARFIRE commercial tokamak fusion reactor was directly used as the fusion driver. This report describes a new design obtained by scaling the basic STARFIRE design to permit the achievement of a blanket power of 6000 MWt. The high temperature blanket design employs a thermally insulated refractory oxide region which provides high temperature (>1000 deg. C) steam at moderate pressures to high temperature electrolysis units. The electrolysis process selected is based on the high temperature, solid electrolyte fuel cell technology developed by Westinghouse. An initial process design and plant layout has been completed; component cost and plant economics studies are now underway to develop estimates of hydrogen production costs and to determine the sensitivity of this cost to changes in major design parameters. (author)

  2. A study of metallic coatings obtained by electrolysis of molten salts

    Broc, Michel.

    1978-06-01

    An appropriate technique has been developed for obtaining compact metallic coatings from electrolysis of molten salts. Through the use of this method, it has been possible to produce pure metal deposits which, until now, has been extremely difficult to do. The apparatus used and the main steps of the process such as dehydration of the solvant, degassing of the equipment, and starting of the electrolytic process, are first described. This is followed by a discussion of the deposits of the metals beryllium, uranium, tantalum and tungsten obtained from electrolysis of molten fluorides at temperatures between 600 and 800 0 C. The metal coatings so obtained are homogeneous and show continuity, their thicknesses varying from a few microns to a millimeter or more. They have been studied by measurements. As potential applications of this new technique, one can mention the growth of diffusion barriers and the production of cathodes for thermoionic emission. The method can also be used for electroforming. An intermetallic diffusion between the deposit and the substrate has been observed in some cases. The advantage of the technique of melt electrolysis in obtaining metal coatings of enhanced thicknesses is illustrated by taking the beryllium-nickel system as an example. It is shown that the thickness obtained is proportional to the square root of growth time and is about 6 to 8 times larger than that obtained by conventional techniques [fr

  3. Wind power generation plant installed on cargo ship and marine resources recovery by seawater electrolysis

    Murahara, M. [Tokyo Inst. of Technology, Tokyo (Japan)]|[Tokai Univ., Hiratsuka, Kanagawa (Japan); Seki, K. [Mingdao Univ., Taiwan (China)]|[Tokai Univ., Hiratsuka, Kanagawa (Japan). Research Inst. of Science and Technology

    2008-07-01

    Transmission loss from offshore wind turbine arrays is directly proportional to the length of the cable that brings power onshore. In order to minimize transmission loss, wind-generated electricity needs to be stored temporarily in a different form. Seawater, rock salt, and water of saline lakes can be desalinated and then electrolyzed to produce hydrogen. This paper presented a new method of offshore sodium production in Japan by seawater electrolysis. In this technique, sodium is manufactured on site by molten-salt electrolysis as a solid fuel. Sodium is electrolytically collected from the seawater or rock salt by the wind power generation. The sodium is then transported to a hydrogen power plant on land and then is added water to generate hydrogen for operating a hydrogen combustion turbine. The sodium hydroxide by-product is then supplied to the soda industry as a raw material. In seawater electrolysis, not only sodium but also fresh water, magnesium, calcium, potassium, sodium hydroxide, chlorine, oxygen, hydrogen, hydrochloric acid, and sulfuric acid are isolated and recovered as by-products. 5 refs., 6 figs.

  4. CFD Model Of A Planar Solid Oxide Electrolysis Cell For Hydrogen Production From Nuclear Energy

    Grant L. Hawkes; James E. O'Brien; Carl M. Stoots; J. Stephen Herring

    2005-01-01

    A three-dimensional computational fluid dynamics (CFD) model has been created to model high temperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). The model represents a single cell as it would exist in an electrolysis stack. Details of the model geometry are specific to a stack that was fabricated by Ceramatec2, Inc. and tested at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean model results are shown to compare favorably with experimental results obtained from an actual ten-cell stack tested at INL

  5. Preliminary estimations on the heat recovery method for hydrogen production by the high temperature steam electrolysis

    Koh, Jae Hwa; Yoon, Duck Joo

    2009-01-01

    As a part of the project 'development of hydrogen production technologies by high temperature electrolysis using very high temperature reactor', we have developed an electrolyzer model for high temperature steam electrolysis (HTSE) system and carried out some preliminary estimations on the effects of heat recovery on the HTSE hydrogen production system. To produce massive hydrogen by using nuclear energy, the HTSE process is one of the promising technologies with sulfur-iodine and hybrid sulfur process. The HTSE produces hydrogen through electrochemical reaction within the solid oxide electrolysis cell (SOEC), which is a reverse reaction of solid oxide fuel cell (SOFC). The HTSE system generally operates in the temperature range of 700∼900 .deg. C. Advantages of HTSE hydrogen production are (a) clean hydrogen production from water without carbon oxide emission, (b) synergy effect due to using the current SOFC technology and (c) higher thermal efficiency of system when it is coupled nuclear reactor. Since the HTSE system operates over 700 .deg. C, the use of heat recovery is an important consideration for higher efficiency. In this paper, four different heat recovery configurations for the HTSE system have been investigated and estimated

  6. Enhanced dewaterability of textile dyeing sludge using micro-electrolysis pretreatment.

    Ning, Xun-An; Wen, Weibin; Zhang, Yaping; Li, Ruijing; Sun, Jian; Wang, Yujie; Yang, Zuoyi; Liu, Jingyong

    2015-09-15

    The effects of micro-electrolysis treatment on textile dyeing sludge dewatering and its mechanisms were investigated in this study. Capillary suction time (CST) and settling velocity (SV) were used to evaluate sludge dewaterability. Extracellular polymeric substances (EPS) concentration and sludge disintegration degree (DDSCOD) were determined to explain the observed changes in sludge dewaterability. The results demonstrated that the micro-electrolysis could significantly improve sludge dewaterability by disrupting the sludge floc structure. The optimal conditions of sludge dewatering were the reaction time of 20 min, initial pH of 2.5, Fe/C mass ratio of 1/1, and the iron powder dosage of 2.50 g/L, which achieved good CST (from 34.1 to 27.8 s) and SV (from 75 to 60%) reduction efficiency. In addition, the scanning electron microscope (SEM) images revealed that the treated sludge floc clusters are broken up and that the dispersion degree is better than that of a raw sludge sample. The optimal EPS concentration and DDSCOD to obtain maximum sludge dewaterability was 43-46 mg/L and 4.2-4.9%, respectively. The destruction of EPS was one of the primary reasons for the improvement of sludge dewaterability during micro-electrolysis treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Status of the INL high-temperature electrolysis research program –experimental and modeling

    J. E. O' Brien; C. M. Stoots; M. G. McKellar; E. A. Harvego; K. G. Condie; G. K. Housley; J. S. Herring; J. J. Hartvigsen

    2009-04-01

    This paper provides a status update on the high-temperature electrolysis (HTE) research and development program at the Idaho National Laboratory (INL), with an overview of recent large-scale system modeling results and the status of the experimental program. System analysis results have been obtained using the commercial code UniSim, augmented with a custom high-temperature electrolyzer module. The process flow diagrams for the system simulations include an advanced nuclear reactor as a source of high-temperature process heat, a power cycle and a coupled steam electrolysis loop. Several reactor types and power cycles have been considered, over a range of reactor coolant outlet temperatures. In terms of experimental research, the INL has recently completed an Integrated Laboratory Scale (ILS) HTE test at the 15 kW level. The initial hydrogen production rate for the ILS test was in excess of 5000 liters per hour. Details of the ILS design and operation will be presented. Current small-scale experimental research is focused on improving the degradation characteristics of the electrolysis cells and stacks. Small-scale testing ranges from single cells to multiple-cell stacks. The INL is currently in the process of testing several state-of-the-art anode-supported cells and is working to broaden its relationship with industry in order to improve the long-term performance of the cells.

  8. Summary Report on Solid-oxide Electrolysis Cell Testing and Development

    J.E. O' Brien; X. Zhang; R.C. O' Brien; G.L. Hawkes

    2012-01-01

    Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cells (SOECs) for large-scale hydrogen production from steam over a temperature range of 800 to 900 C. From 2003 to 2009, this work was sponsored by the United States Department of Energy Nuclear Hydrogen Initiative, under the Office of Nuclear Energy. Starting in 2010, the high-temperature electrolysis (HTE) research program has been sponsored by the INL Next Generation Nuclear Plant Project. This report provides a summaryof program activities performed in Fiscal Year (FY) 2011 and the first quarter of FY-12, with a focus on small-scale testing and cell development activities. HTE research priorities during this period have included the development and testing of SOEC and stack designs that exhibit high-efficiency initial performance and low, long-term degradation rates. This report includes contributions from INL and five industry partners: Materials and Systems Research, Incorporated (MSRI); Versa Power Systems, Incorporated (VPS); Ceramatec, Incorporated; National Aeronautics and Space Administration - Glenn Research Center (NASA - GRC); and the St. Gobain Advanced Materials Division. These industry partners have developed SOEC cells and stacks for in-house testing in the electrolysis mode and independent testing at INL. Additional fundamental research and post-test physical examinations have been performed at two university partners: Massachusetts Institute of Technology (MIT) and the University of Connecticut. Summaries of these activities and test results are also presented in this report.

  9. Mercury(II) removal from aqueous solutions and wastewaters using a novel cation exchanger derived from coconut coir pith and its recovery

    Anirudhan, T.S. [Department of Chemistry, University of Kerala, Kariavattom, Trivandrum 695581 (India)], E-mail: tsani@rediffmail.com; Divya, L.; Ramachandran, M. [Department of Chemistry, University of Kerala, Kariavattom, Trivandrum 695581 (India)

    2008-09-15

    A new adsorbent (PGCP-COOH) having carboxylate functional group at the chain end was synthesized by grafting poly(hydroxyethylmethacrylate) onto coconut coir pith, CP (a coir industry-based lignocellulosic residue), using potassium peroxydisulphate as an initiator and in the presence of N,N'-methylenebisacrylamide as a cross-linking agent. The adsorbent was characterized with the help of infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and potentiometric titrations. The ability of PGCP-COOH to remove Hg(II) from aqueous solutions was assessed using batch adsorption technique under kinetic and equilibrium conditions. Adsorbent exhibits very high adsorption potential for Hg(II) and more than 99.0% removal was achieved in the pH range 5.5-8.0. Adsorption process was found to follow first-order-reversible kinetics. An increase of ionic strength of the medium caused a decrease in metal removal, indicating the occurrence of outer-sphere surface complex mechanism. The equilibrium data were fitted well by the Freundlich isotherm model (R{sup 2} = 0.99; {chi}{sup 2} 1.81). The removal efficiency was tested using chlor-alkali industry wastewater. Adsorption isotherm experiments were also conducted for comparison using a commercial carboxylate-functionalized ion exchanger, Ceralite IRC-50. Regeneration experiments were tried for four cycles and results indicate a capacity loss of <9.0%.

  10. Mercury(II) removal from aqueous solutions and wastewaters using a novel cation exchanger derived from coconut coir pith and its recovery

    Anirudhan, T.S.; Divya, L.; Ramachandran, M.

    2008-01-01

    A new adsorbent (PGCP-COOH) having carboxylate functional group at the chain end was synthesized by grafting poly(hydroxyethylmethacrylate) onto coconut coir pith, CP (a coir industry-based lignocellulosic residue), using potassium peroxydisulphate as an initiator and in the presence of N,N'-methylenebisacrylamide as a cross-linking agent. The adsorbent was characterized with the help of infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and potentiometric titrations. The ability of PGCP-COOH to remove Hg(II) from aqueous solutions was assessed using batch adsorption technique under kinetic and equilibrium conditions. Adsorbent exhibits very high adsorption potential for Hg(II) and more than 99.0% removal was achieved in the pH range 5.5-8.0. Adsorption process was found to follow first-order-reversible kinetics. An increase of ionic strength of the medium caused a decrease in metal removal, indicating the occurrence of outer-sphere surface complex mechanism. The equilibrium data were fitted well by the Freundlich isotherm model (R 2 = 0.99; χ 2 1.81). The removal efficiency was tested using chlor-alkali industry wastewater. Adsorption isotherm experiments were also conducted for comparison using a commercial carboxylate-functionalized ion exchanger, Ceralite IRC-50. Regeneration experiments were tried for four cycles and results indicate a capacity loss of <9.0%

  11. Mercury(II) removal from aqueous solutions and wastewaters using a novel cation exchanger derived from coconut coir pith and its recovery.

    Anirudhan, T S; Divya, L; Ramachandran, M

    2008-09-15

    A new adsorbent (PGCP-COOH) having carboxylate functional group at the chain end was synthesized by grafting poly(hydroxyethylmethacrylate) onto coconut coir pith, CP (a coir industry-based lignocellulosic residue), using potassium peroxydisulphate as an initiator and in the presence of N,N'-methylenebisacrylamide as a cross-linking agent. The adsorbent was characterized with the help of infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, and potentiometric titrations. The ability of PGCP-COOH to remove Hg(II) from aqueous solutions was assessed using batch adsorption technique under kinetic and equilibrium conditions. Adsorbent exhibits very high adsorption potential for Hg(II) and more than 99.0% removal was achieved in the pH range 5.5-8.0. Adsorption process was found to follow first-order-reversible kinetics. An increase of ionic strength of the medium caused a decrease in metal removal, indicating the occurrence of outer-sphere surface complex mechanism. The equilibrium data were fitted well by the Freundlich isotherm model (R(2)=0.99; chi(2)=1.81). The removal efficiency was tested using chlor-alkali industry wastewater. Adsorption isotherm experiments were also conducted for comparison using a commercial carboxylate-functionalized ion exchanger, Ceralite IRC-50. Regeneration experiments were tried for four cycles and results indicate a capacity loss of <9.0%.

  12. Removal of Arsenic from Wastewaters by Airlift Electrocoagulation: Part 3: Copper Smelter Wastewater Treatment

    Hansen, H.K.; Ottosen, Lisbeth M.

    2010-01-01

    The arsenic content in wastewater is of major concern for copper smelters. A typical complex wastewater treatment is needed with a combination of chemical and physical processes. Electrocoagulation (EC) has shown its potential for arsenic removal due to the formation of ferric hydroxide-arsenate ...... threshold value for wastewater discharge could rapidly be reached when the conventional method did not clean the wastewater sufficiently....

  13. Water brief-WDM & wastewater reuse

    aalfouns

    Wastewater Reuse for Water Demand Management in the Middle East and ... Among the substantial WDM tools in MENA is the use of wastewater to reduce the pressure on scarce freshwater .... recycled water to irrigate crops with associated ...

  14. Management and Planning for Small Community Wastewater

    Operators Small Systems Management and Planning for Small Community Wastewater The NESC has provided of Clean Water Agencies (NACWA) Achieving Environmental Excellence: An Environmental Management Agencies, The Office of Wastewater Management at EPA, in cooperation with the Global Environment and

  15. Properties of Concrete Mixes with Carwash Wastewater

    Shahidan Shahiron

    2017-01-01

    Full Text Available The rapid growth of the car wash industry today results in the need for wastewater reclamation. Thus, this paper aims to investigate the effect of using car wash wastewater on concrete properties in terms of mechanical properties. The basic characteristics of wastewater were investigated according to USEPA (Method 150.1 & 3 00.0 while the mechanical properties of concrete with car wash wastewater were compared according to ASTM C1602 and BS EN 1008 standards. In this research, the compressive strength, modulus of elasticity and tensile strength were studied. The percentages of wastewater replaced in the concrete mix ranged from 0% up to 40%. In addition, the results also suggest that the concrete with 20% car wash wastewater achieved the highest compressive strength and modulus of elasticity compared to other compositions of wastewater. Moreover, the results also recommended that concrete mixed with car wash wastewater has better compressive strength compared to conventional concrete.

  16. Condutivity effect in electro-coagulation-flotation applied to physico-chemical wastewater treatment

    Francisco Javier Cuba Terán

    2007-03-01

    Full Text Available This study reports on the effect of conductivity on the simultaneous applicability of water electrolysis , chemical coagulation and flotation fundamentals in the treatment of wastewater with large amounts of suspended matter, characterizing electro-coagulation-flotation (ECF . Results from experiments carried out in a pilot study implanted and operated in the Laboratory of Environment Control (LCA, at the State University of Campinas in Limeira are presented. ECF was developed in an electrolytic reactor where water passed through aluminum electrodes connected to a power supply. Electrochemical reactions promoted Al3+ ions emission from anode, neutralizing repulsive pollutant forces, forming flakes. An evolution of micro hydrogen bubbles occurred, carrying the flakes to the top of the solution, causing flotation and polluter removal. System monitoring aimed at reaching optimal operation conditions regarding time of liquid permanence in the reactor, influence of the NaC1 addition on the increase of affluent conductivity, and influence of polarity inversion over cathodic passivation. Results from carwash wastewater treatment reported 86% efficiency rate for color, 90,15% for turbidity and 85,43% for oil and axle-grease removal.

  17. Composite wastewater treatment by aerated electrocoagulation and modified peroxi-coagulation processes.

    Kumar, Abhijeet; Nidheesh, P V; Suresh Kumar, M

    2018-08-01

    Treatment of composite wastewater generating from the industrial estates is a great challenge. The present study examines the applicability of aerated electrocoagulation and modified peroxi-coagulation processes for removing color and COD from composite wastewater. Iron plates were used as anodes and cathodes in both electrochemical processes and experiments were carried out in a working volume of 2 L. Aeration enhanced the efficiency of electrocoagulation process significantly. More than 50% of COD and 60% of color were removed after 1 h of electrocoagulation process operated at pH 3 and applied voltage of 1 V. Efficiency of the modified peroxi-coagulation process was significantly higher than that of aerated electrocoagulation. COD and color removal efficiencies of the modified peroxi-coagulation process were found as 77.7% and 97%, respectively after 1 h of electrolysis operated at 1 V, solution pH 3 and 50 mM hydrogen peroxide addition. This improved efficiency of modified peroxi-coagulation compared to aerated electrocoagulation is mainly due to the attack of in-situ generated hydroxyl radicals. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Industrial-scale application of the plunger flow electro-oxidation reactor in wastewater depth treatment.

    Huang, Guolong; Yao, Jiachao; Pan, Weilong; Wang, Jiade

    2016-09-01

    Effluents after biochemical treatment contain pollutants that are mostly non-degradable. Based upon previous pilot-scale test results, an industrial-scale electro-oxidation device was built to decompose these refractory materials in the effluent from a park wastewater treatment plant. The electro-oxidation device comprised a ditch-shaped plunger flow electrolysis cell, with mesh-plate Ti/PbO2 electrodes as the anode and the same size mesh-plate Ti as the cathode. Wastewater flowed vertically through electrodes; the effective volume of the cell was 2.8 m(3), and the surface-to-volume ratio was 17.14 m(2) m(-3). The optimal current density was 100 A m(-2), and a suitable flow velocity was 14.0 m h(-1). The removal efficiencies for chemical oxygen demand and color in the effluent were over 60.0 and 84.0 %, respectively. In addition, the electro-oxidation system offered a good disinfection capability. The specific energy consumption for this industrial-scale device was 43.5 kWh kg COD(-1), with a current efficiency of 32.8 %, which was superior to the pilot-scale one. To meet the requirements for emission or reuse, the operation cost was $0.44 per ton of effluent at an average price for electricity of $0.11 kWh(-1).

  19. Process design of high-concentration benzimidazole wastewater treatment based on the molecular structure of contaminants.

    Li, Chenru; Qian, Kun; Liu, Qinyao; Zhang, Qianyi; Yao, Chen; Song, Wei; Wang, Yihong

    2018-04-01

    Benzimidazole is an important intermediate in industry and it is usually difficult to be degraded by many treatment technologies. Looking for a highly effective, environment-friendly degradation process for benzimidazole wastewater is of great significance to reduce pollution. Based on the structure of contaminants, the micro-electrolysis (ME) coupled with the Fenton technique was chosen to degrade the industrial benzimidazole wastewater. Special feeding was applied to maintain the suitable hydrogen peroxide (H 2 O 2 ) concentration to produce the hydroxyl radicals (•OH) as much as possible and protect •OH from being quenched by excess H 2 O 2 according to the reaction mechanism. The results showed that this combined technique was highly efficient to decompose benzimidazole compounds. More chemical oxygen demand (COD) could be reduced when flow control was used, compared to the flow not being controlled. The COD removal rate could reach 85.2% at optimal parameters. Then the effluent of this process was combined with the existing biochemical system for further degradation. The studies of Ultraviolet Spectrophotometry, Fourier Transform Infrared Spectroscopy and Liquid Chromatography Mass Spectrometry showed that both 2-(a-Hydroxyethyl) benzimidazole and 2-Acetylbenzimidazole were decomposed to the isopropanolamine and aniline after the ME treatment; then the intermediates were oxidized into oxalic acid after the Fenton reaction.

  20. Activated carbon electrodes: electrochemical oxidation coupled with desalination for wastewater treatment.

    Duan, Feng; Li, Yuping; Cao, Hongbin; Wang, Yi; Crittenden, John C; Zhang, Yi

    2015-04-01

    The wastewater usually contains low-concentration organic pollutants and some inorganic salts after biological treatment. In the present work, the possibility of simultaneous removal of them by combining electrochemical oxidation and electrosorption was investigated. Phenol and sodium chloride were chosen as representative of organic pollutants and inorganic salts and a pair of activated carbon plate electrodes were used as anode and cathode. Some important working conditions such as oxygen concentration, applied potential and temperature were evaluated to reach both efficient phenol removal and desalination. Under optimized 2.0 V of applied potential, 38°C of temperature, and 500 mL min(-1) of oxygen flow, over 90% of phenol, 60% of TOC and 20% of salinity were removed during 300 min of electrolysis time. Phenol was removed by both adsorption and electrochemical oxidation, which may proceed directly or indirectly by chlorine and hypochlorite oxidation. Chlorophenols were detected as degradation intermediates, but they were finally transformed to carboxylic acids. Desalination was possibly attributed to electrosorption of ions in the pores of activated carbon electrodes. The charging/regeneration cycling experiment showed good stability of the electrodes. This provides a new strategy for wastewater treatment and recycling. Copyright © 2014 Elsevier Ltd. All rights reserved.