Updated on 2022/05/18

写真a

 
SAKAKIBARA, yutaka
 
Affiliation
Faculty of Science and Engineering, School of Creative Science and Engineering
Job title
Professor

Concurrent Post

  • Faculty of Science and Engineering   Graduate School of Environment and Energy Engineering

  • Affiliated organization   Global Education Center

  • Faculty of Science and Engineering   Graduate School of Creative Science and Engineering

Research Institute

  • 2020
    -
    2022

    理工学術院総合研究所   兼任研究員

Education

  •  
    -
    1981

    Gunma University   Graduate School, Division of Engineering  

Degree

  • Dr.Eng.

  • 名古屋大学   工学博士

Research Experience

  • 2001
    -
     

    Waseda University, Professor

  • 1993
    -
    2001

    Gunma University, Associate Professor

  • 1993
    -
    2001

    Gunma University, Associate Professor

  • 1990
    -
    1993

    Gunma University, Lecturer

  • 1982
    -
    1990

    Gunma University, Research Assistant

Professional Memberships

  •  
     
     

    IWA

  •  
     
     

    環境科学会

  •  
     
     

    IAWQ(International Association on Water Quality)

  •  
     
     

    化学工学会

  •  
     
     

    土木学会

  •  
     
     

    水環境学会

▼display all

 

Research Areas

  • Environmental systems for civil engineering

Research Interests

  • Environmental Remediation

Papers

  • A Novel Electrochemical Advanced Oxidation Process with Generation and Reduction of Ozone

    Ushio, Toshiki, Sakakibara, Yutaka, Komori, Masahito

    PROCEEDINGS OF ENVIRONMENTAL AND SANITARY ENGINEERING RESEARCH   73 ( 7 ) 329 - 335  2017.10

    DOI

  • Acute Exposure to 17 alpha-Ethinylestradiol Alters Aggressive Behavior of Mosquitofish (Gambusia affinis) Toward Japanese Medaka (Oryzias latipes)

    Hieu M. Dang, Yoshihiko Inagaki, Yuta Yamauchi, Takaaki Kurihara, Cong H. Vo, Yutaka Sakakibara

    BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY   98 ( 5 ) 643 - 648  2017.05  [Refereed]

     View Summary

    Behavior of the mosquitofish (Gambusia affinis) toward the Japanese medaka (Oryzias latipes) was tested under exposure to environmental 17 alpha-ethinylestradiol (EE2), a synthetic derivative of natural estrogen, estradiol. The mosquitofish were exposed to EE2 at different concentrations-0, 0.5, 5.0, and 50.0 ng/L-for 2 days, before their behavioral changes toward the medaka were observed. Results indicate that female mosquitofish became more aggressive at the high level of EE2 (50 ng/L), in terms of how persistently they attempted to approach the medaka. The males showed increased aggressive behavior toward the medaka, by significantly increasing the number and persistence of approach attempts at the low (0.5 and 5 ng/L) levels of EE2. At the highest EE2 concentration (50 ng/L), however, the number of attempts decreased, while the persistence increased in the males showing the same pattern as in the females. All behavioral changes were reversed once EE2 was removed from the environment.

    DOI

  • Identification and application of Phyto-Fenton reactions

    Yoshihiko Inagaki, Vo Huu Cong, Yutaka Sakakibara

    Chemosphere   144   1443 - 1450  2016.02  [Refereed]

     View Summary

    © 2015 Elsevier Ltd.The formation of hydroxyl radicals (•OHs) by aquatic plants was investigated using electron-spin-resonance (ESR) spectroscopy and fluorescence microscopy. ESR observations, using 5- (diethoxyphosphoryl)-5-methyl-pyrroline N-oxide as a trapping agent, indicated that the signals produced by aquatic plants ground with ferrous iron ions are almost identical to those produced by Fenton's reagent. In addition, fluorescence was observed in the oxidized form of aminophenyl fluorescein in the presence of ferrous ions as well as any particles of colloidal ferrihydrite, magnetite, and ferric-ion-exchanged zeolite, while no fluorescence appeared in the absence of these iron compounds. Moreover, fluorescence-microscopy observations demonstrated that fluorescence mainly occurs on the surface of aquatic plants at neutral pH in the presence of the latter three solid iron compounds, implying the occurrence of heterogeneous phyto-Fenton reactions utilizing endogenous hydrogen peroxide (H2O2) in the aquatic plants. Furthermore, batch treatments of the pollutant 17α-ethinylestradiol (EE2), using colloidal ferrihydrite iron, indicated the feasible removal of EE2 with enhanced performance, lower-or apparently no-consumption of endogenous H2O2, and no significant stress to the aquatic plants. We concluded that the treatment of environmental pollutants through •OH formations via heterogeneous phyto-Fenton reactions should be a feasible alternative to conventional wastewater and water-treatment processes.

    DOI PubMed

  • Removal of endocrine disrupters by a carbon electrolytic reactor

    V. H. Cong, T. D. Vien, Y. Sakakibara

    Vietnum J. Agr. Sci   14 ( 10 ) 1502 - 1509  2016

  • Recent Developments in Electrochemical Technology for Water and Wastewater Treatments

    Cong Vo Huu, Sakakibara Yutaka, Komori Masahito, Kishimoto Naoyuki, Watanabe Tomohide, Mishima Iori, Ihara Ikko, Tanaka Tsuneo, Yoshida Yukihito, Ozaki Hiroaki

    Journal of Water and Environment Technology   14 ( 2 ) 25 - 36  2016

     View Summary

    This paper presents the recent attention in scientific studies and development of electrochemical processes. Electrochemical technology has contributed significantly to the purification of water for better human health and aquatic life forms. In this study, we emphasize the developmental trends of electrochemical technologies, their applications, and recent developments in the context of water and wastewater treatments. Recent studies have made great advances in investigating and optimizing advanced electrochemical oxidation processes in treatment of various organic pollutants, reduction of halogenated contaminants, and disinfection of microorganisms. Besides, electrochemical oxidation processes have been combined with other treatment methods to enable their practical application. Excellent electro-catalytic treatment of contaminant and their by-products was achieved through the application of mixed metal oxides (PbO2, SnO2, Ti/RuO2, etc.), Pt, and boron-doped diamond (BDD) electrodes. Several studies have focused on selective removal of trace pollutants in a complex matrix. These studies have shown the possibility of removing target pollutants with relatively low energy consumption. It can be concluded that enhancement of treatment performance of the present technologies will contribute to a wider application of electrochemical processes in water and wastewater treatment.

    CiNii

  • Continuous treatments of estrogens through polymerization and regeneration of electrolytic cells

    Vo Huu Cong, Yutaka Sakakibara

    Journal of Hazardous Materials   285   304 - 310  2015.03

     View Summary

    This study proposes a novel electrolytic method for simultaneous removal of trace estrogens and regeneration of electrolytic cells for long-term wastewater treatment. Continuous treatments of estrogens estrone (E1), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2) were theoretically and experimentally studied using an electrolytic reactor equipped with a multi-packed granular glassy carbon electrode reactor. Experimental results demonstrated that E1, E2 and EE2 were effectively removed through electro-polymerization on the granular glassy carbon (and Pt/Ti) anode counter. Polymer formed during continuous treatment was quickly decomposed and electrodes were regenerated completely by OH radicals produced through the reduction of ozone. Calculated overall energy consumptions were less than 10Wh/m3, demonstrating extremely low energy consumptions. In addition, a mathematical model developed based on the limiting mass transfer rate and post-regeneration could represent general trends in time series data observed in experiments.

    DOI PubMed

  • Continuous treatments of estrogens through polymerization and regeneration of electrolytic cells

    Vo Huu Cong, Yutaka Sakakibara

    JOURNAL OF HAZARDOUS MATERIALS   285   304 - 310  2015.03  [Refereed]

     View Summary

    This study proposes a novel electrolytic method for simultaneous removal of trace estrogens and regeneration of electrolytic cells for long-term wastewater treatment. Continuous treatments of estrogens estrone (El), 17 beta-estradiol (E2) and 17 alpha-ethinyl estradiol (EE2) were theoretically and experimentally studied using an electrolytic reactor equipped with a multi-packed granular glassy carbon electrode reactor. Experimental results demonstrated that El, E2 and EE2 were effectively removed through electro-polymerization on the granular glassy carbon (and Pt/Ti) anode counter. Polymer formed during continuous treatment was quickly decomposed and electrodes were regenerated completely by (OH)-O-center dot radicals produced through the reduction of ozone. Calculated overall energy consumptions were less than 10 Wh/m(3), demonstrating extremely low energy consumptions. In addition, a mathematical model developed based on the limiting mass transfer rate and post-regeneration could represent general trends in time series data observed in experiments. (C) 2014 Elsevier B.V. All rights reserved.

    DOI

  • Removal of estrogens by electrochemical oxidation process

    Vo Huu Cong, Sota Iwaya, Yutaka Sakakibara

    JOURNAL OF ENVIRONMENTAL SCIENCES   26 ( 6 ) 1355 - 1360  2014.06  [Refereed]

     View Summary

    Treatments of estrogens such as Estrone (E1), Estradiol (E2) and Ethinylestradiol (EE2) were conducted using an electrolytic reactor equipped with multi-packed granular glassy carbon electrodes. Experimental results showed that E1, E2 and EE2 were oxidized in the range of 0.45-0.85 V and were removed through electro-polymerization. Observed data from continuous experiments were in good agreement with calculated results by a mathematical model constructed based on mass transfer limitation. In continuous treatment of trace estrogens (1 mu g/L), 98% of E1, E2 and EE2 were stably removed. At high loading rate (100 mu g/L), removal efficiency of E1 was kept around 74%-88% for 21 days, but removal efficiency reduced due to passivation of electrodes. However, removal efficiency was recovered after electrochemical regeneration of electrodes in presence of ozone. Electric energy consumption was observed in the range of 1-2 Wh/m(3). From these results, we concluded that the present electrochemical process would be an alternative removal of estrogens.

    DOI

  • Electrolytic Treatment of Trace Natural and Synthetic Estrogens

    Vo Huu Cong, Yutaka Sakakibara

    JOURNAL OF ADVANCED OXIDATION TECHNOLOGIES   17 ( 1 ) 115 - 120  2014.01  [Refereed]

     View Summary

    Electrochemical removals of natural and synthetic estrogens, Estrone (E1), 17 beta-Estradiol (E2) and Ethynylestradiol (EE2), were experimentally studied using granular electrolytic reactor in combination with a cyclic voltammetric technique. Experimental results showed that by an application of electric current, the estrogens were oxidized at 600-800 mV (vs. Ag/AgCl reference electrode) on the surface of anode and then removed through polymerization of estrogens. Moreover, the electrochemical removal of the estrogens could be reasonably well simulated by a mathematical model developed assuming the external liquid-film mass transfer as a rate-limiting step. Furthermore, it was found that E1 was produced and then removed during the treatment of E2. Further study will be needed to quantify and control the electro-polymerization of estrogens.

  • Removal of estrogens by electrochemical oxidation process.

    Removal of estrogens by electrochemical oxidation process.   26 ( 6 )  2014  [Refereed]

     View Summary

    :Treatments of estrogens such as Estrone (E1), Estradiol (E2) and Ethinylestradiol (EE2) were conducted using an electrolytic reactor equipped with multi-packed granular glassy carbon electrodes. Experimental results showed that E1, E2 and EE2 were oxidized in the range of 0.45-0.85 V and were removed through electro-polymerization. Observed data from continuous experiments were in good agreement with calculated results by a mathematical model constructed based on mass transfer limitation. In continuous treatment of trace estrogens (1 μg/L), 98% of E1, E2 and EE2 were stably removed. At high loading rate (100 μg/L), removal efficiency of E1 was kept around 74%-88% for 21 days, but removal efficiency reduced due to passivation of electrodes. However, removal efficiency was recovered after electrochemical regeneration of electrodes in presence of ozone. Electric energy consumption was observed in the range of 1-2 Wh/m(3). From these results, we concluded that the present electrochemical process would be an alternative removal of estrogens.

    DOI

  • Biological Fenton's Oxidation of Pentachlorophenol by Aquatic Plants

    Andre Rodrigues dos Reis, Yukako Kyuma, Yutaka Sakakibara

    BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY   91 ( 6 ) 718 - 723  2013.12  [Refereed]

     View Summary

    This study proposes a new treatment method to decompose persistent chemicals such as pentachlorophenol (PCP) in water, utilizing hydrogen peroxide present in aquatic plants to proceed the biological Fenton reaction. PCP was not effectively removed by aquatic plants. However, by adding 2.8 mM of Fe2+, there was a rapid removal of PCP while at the same time consumption of endogenous hydrogen peroxide occurred. It was observed the increase of chloride ions formation in water-confirming the complete degradation of PCP. These results demonstrated that PCP was oxidized through a biological Fenton reaction, and hydrogen peroxide in aquatic plants was a key endogenous substance in treatment of refractory toxic pollutants.

    DOI

  • High Efficient Phosphate Removal and HAP Recovery by a Multi-Electrode System

    PROCEEDINGS OF ENVIRONMENTAL AND SANITARY ENGINEERING RESEARCH   69 ( 7 ) III_137 - III_143  2013

     View Summary

    Continuous experiments for phosphate removal and recovery from a synthetic wastewater containing calcium phosphate were carried out using an electrolytic reactor equipped with a multi-electrode system. Experimental results demonstrated that phosphate was removed by deposition of aggregates in reactor. In addition, it was found that removal rates and recovery rates of phosphate increased and, after reaching their maximum values, decreased with an increment of applied electric current. Deposit in reactor was recovered and was identified as hydroxyapatite (HAP) from XRD analysis. Furthermore, from comparisons of observed and calculated ions fluxes, it was shown that removal rates of phosphate had a maximum value at a certain electric current density and were controlled by either electrolytic production of hydroxyl ion or mass transfer of hydrogen phosphate ion depending on applied electric current density. Moreover, it was considered that the removal and recovery performance could be enhanced by using working electrodes having larger specific surface area.

    CiNii

  • Operating Condition of Bio-Fenton Process for Treatments of Orange II

    Y. Kyuma, Y. Sakakibara

    Procs. of the 18th International Conference on Advanced Oxidation Technology (AOT-18)    2012.11

  • Performance and kinetics of Estrogens Removals by Aquatic Plants

    Y. Inagaki, T. Fujita, A. R. dos Reis, S. Suzuki, Y. Sakakibara

    Procs. of The 4th IWA Asia-Pacific Young Water Professionals Conference   Oral-95  2012.11

  • 水生植物のエストロゲン類浄化能力に関する基礎的研究

    稲垣嘉彦, 藤田泰史郎, Andre Rodrigues, dos Reis, 鈴木 詩麻, 榊原 豊

    土木学会論文集G(環境)   68 ( 7 ) 77 - 85  2012.11  [Refereed]

  • Electrolytic Treatment of Trace Natural and Synthetic Estrogens

    V. H. Cong, Y. SAKAKIBARA

    Procs. of the 18th International Conference on Advanced Oxidation Technology (AOT-18    2012.10

  • Removal Mechanism of Endocrine Disrupting Chemicals by Aquatic Plants

    A. R. dos Reis, Y. Sakakibara

    Association of Pacific Rim Universities FELLOWS PROGRAM 2012    2012.06

  • Strategic Environmental Assessment of Zero Waste to Landfill in Thai Paper Mill

    S. Chotiwan, Y. Sakakibara, M. Murayama

    Procs. of Environmental Science and Technology     570 - 575  2012.06

  • Hydrogen Dissolution Rates in Hydrogenotrophic Denitrification Process Equipped with Solid-Polymer-Electrolyte (SPE) Membrane Electrode

    R. Mine, M. Komori, Y. Sakakibara

    Procs. of Environmental Science and Technology     57 - 63  2012.06

  • Phosphorus Removal and Recovery from Wastewater by Electrochemical Process

    H. Yoshino, Y. Sakakibara

    Procs. of Environmental Science and Technology     196 - 201  2012.06

  • Electron Spin Resonance Analysis of Bio-Fenton Process

    S. Nagahashi, Y. Sakakibara

    Procs. of Environmental Science and Technology     375 - 380  2012.06

  • Biological Fenton’s degradation of chlorinated endocrine disrupting chemicals by aquatic plants

    A. R. dos Reis, Y. Kyuma, M. Atarashi, Y. Sakakibara

    Procs. of Environmental Science and Technology    2012.06

  • Electrochemical treatment of trace endocrine disrupting chemicals by a novel granular electrode

    V. H. Cong, Y. Sakakibara

    Procs. of Environmental Science and Technology     367 - 374  2012.06

  • A Biological Fenton Reaction for the Complete Decomposition of Chlorinated Compounds

    Y. Inagaki, A. R. dos Reis, Y. Kyuma, Y. Sakakibara

    Proc. of the Eighth International Conference on Remediation of Chlorinated and Recalcitrant Compounds   F8 106  2012.06

  • Enzymatic Treatment of Endocrine Disrupting Chemicals in Aquatic Plants and Relations to Biological Fenton Reaction

    A. R. dos Reis, Y. Sakakibara

    Water Science and Technology   66 ( 4 ) 775 - 782  2012.04  [Refereed]

  • Field Survey on the Removal of Endocrine Disrupting Chemicals and Pharmaceutical Residues in Oxidation Ponds and Constructed Wetlands in Tropical Areas

    Y. Kasai, Y. Inagaki, Y. Sakakibara, M. Milintawisamai, S. Srilachai

    Journal of Water and Environment Technology   10 ( 4 ) 337 - 345  2012.04

  • Removal Performances of Estrogens by Aquatic Plants

    INAGAKI Yoshihiko, FUJITA Taishiro, REIS Andre Rodrigues dos, SUZUKI Shima, SAKAKIBARA Yutaka

    Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research)   68 ( 7 ) III_77 - III_85  2012  [Refereed]

     View Summary

     In order to clarify the removal performances of estrogens by aquatic plants, experimental studies were conducted using four species of aquatic plants (Ceratophyllum demersum, Riccia fluitans, Spirodela polyrhiza and Limnobium laevigatum) and six enzymes (soluble peroxidase, ionicaly cell wall-bound proxidase, covalently cell wall-bound peroxidase, laccase, polyphenol peroxidase and glutathione-S-transferase) extracted from the plants. Estrone (E1), 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2) were target compounds. It was found that estrogens were efficiently removed by plants as well as by peroxidase and hydrogen peroxide inside plants. Compared with a mathematical model developed based on an assumption of mass transfer diffusion limitation, removal rates of estrogens by aquatic plants were considered to be governed by mass transfer rates of estrogens in liquid film.

    DOI CiNii

  • Bio-Fenton Process for Advanced Treatment of Refractory Compounds

    Y. Sakakibara, A. R. Ruis, K. Kyoma, Y. Inagaki

    PROCEEDINGS OF THE 4TH INTERNATIONAL CONFERENCE ON ENVIRONMENTAL TECHNOLOGY AND KNOWLEDGE TRANSFER     572 - 576  2012  [Refereed]

     View Summary

    Continuous treatments of chlorinated compounds such as 2,4-Dichlbrophenol (2,4-DCP) and Pentachlorophenol (PCP) were conducted using different aquatic plants. Experimental results showed that efficient treatment was achieved for 2,4-DCP but not for PCP. Enzymatic assays indicated that primal enzymes involved in 2,4-DCP removal were peroxidises (POs) that catalyze the following reaction; 2,4-DCP + H2O2 -> Products + H2O. Endogenous H2O2 levels in plants were in the range of 0.1 to 1mmol/kg-F.W. Based on this relatively high H2O2 levels, experimental trials were conducted to decompose PCP by adding Fe2+ ions, demonstrating that PCP could be removed quickly in parallel with the decrease in H2O2 concentration and the production of chloride ions. In addition, OH radical formation was detected by Electron Spin Resonance (ESR) Analysis. These results demonstrate the occurrence of a biological Fenton reaction (i.e. Bio-Fenton Process), which may be used for further treatments of other refractory pollutants.

  • Biological Fenton’s oxidation of pentachlorophenol by aquatic plants

    Reis A. R, Kyuma Y, Sakakibara Y, Srilacha S, Milintawisamai

    Procs. of the 9th International Symposium on Southeast Asian Water Environment    2011.12

  • Continuous Treatment of Endocrine Disrupting Chemicals by Aquatic Plants and Biological Fenton Reaction

    A. R. doe Reis, Y. Sakakibara

    SCE, Ser. G (Environmental Research)   67 ( 7 ) 725 - 734  2011.11

  • Water treatment technology using aquatic plants

    Y. Sakakibara

    Paten (PCT/JP2011/69518)    2011.11

  • Enzymatic degradation of Endocrine Disrupting Chemicals in aquatic plants and relation to biological Fenton reaction

    A.R. Reis, Y. Inagaki, Y. Sakakibara

    Procs. of the 4th IWA-ASPIRE Conference & Exhibition    2011.11

  • Enhanced Water and Wastewater Treatment with Simple Operation by Electrochemical Processes

    Y. Sakakibara

    Procs. of 8th Japan-China Workshop on Technology for Water Pollution Prevention,    2011.11

  • Removal of Chlorinated Compounds by a Biological Fenton Reaction

    Y. Sakakibara, A.R. Ruis, K. Kyuma, Y. Inagaki

    Procs. of 17th International Conference on Advanced Oxidation Technologies for Treatment of Water, Air and Soil (AOTs-17) (invited lecture)    2011.11

  • 三次元多重電解槽を用いたO3生成/還元促進酸化処理に関する基礎的研究

    志村 光哉, Md. Helal Uddin, 榊原 豊

    環境工学論文集   48   697 - 703  2011.11

  • Continuous treatment of endocrine disrupting chemicals by aquatic plants and biological Fenton Reaction

    A. R. Reis, Y. Sakakibara

    JSCE, Ser. G (Environmental Research)   67 ( 7 ) 725 - 734  2011.11

  • Field Survey on Removals of Endocrine Disrupting Chemicals and Pharmaceutical Residues in Oxidation Ponds and Constructed Wetlands in Tropical Areas

    Y. Kasai, Y. Inagaki, Y. Sakakibara, M. Milintawisamai, S. Srilachai

    Procs. of the 4th IWA-ASPIR, USB 1    2011.10

  • Treatments of Trace Phenolic Endocrine Disrupting Chemicals by Aquatic plants

    Y. Sakakibara, A.R. Ruis, K. Tabei, K. Kyuma, Y. Inagaki

    Procs. of IWA 10th Specialized Conference on Small Water and Wastewater Treatment Systems, CD Rom SS4 Water     1 - 8  2011.04

  • An Advanced Oxidation Process Using A 3-Dimensional Electrochemical Reactor Generating and Reducing O3

    M. Shimura, M. H. Uddin, Y. Sakakibara, T. Tanaka

    Proc. of the 4th IWA-ASPIRE Conference and Exhibition     330 - 338  2011

  • 藻類付着生物膜のエストロゲン(E2)浄化能力に関する基礎的研究

    榊原 豊, 中井 壮洋, 森本 紗代, Andre Rodrigues, dos REIS

      41   619 - 617  2010.11

  • Application of life cycle risk assessment (LCRA) of fish to different suburban streams

    Y. Bando, N. Kikuchi, Y. Sakakibara

    Water Practice & Technology   5 ( 3 )  2010.10

    DOI

  • Enzymatic degradation of phenolic endocrine disrupting chemicals by aquatic plants

    A. R. Reis, Y. Inagaki, Y. Sakakibara, S. Srilachai, M. Milintawisama

    Procs. of the 8th International Symposium on Southeast Asian Water Environment    2010.10

  • Peroxidase Concentration Enzymes in Tropical Aquatic Plants, a Potential Tool for Removing New Emerging Pollutants in Water

    M. Milintawisamai, S. Srilachai, R. Suksamran, C. Tanadilok, Y. Sakakibara

    Procs. of the 8th International Symposium on Southeast Asian Water Environment    2010.10

  • Enhanced treatment of endocrine disrupting chemicalsby a granular bed electrochemical reactor

    Y. Sakakibara, T. Kounoike, H. Kashimura

    Water Science and Technology   62 ( 10 ) 2218 - 2214  2010.10  [Refereed]

  • Assessment of Habitat Scale of Zacco platypus by Using Microsatellite DNA Markers

    N. Kosaka, N. Koizumi, Y. Sakakibara

      1   448  2010.06

  • Effectiveness of Aquatic Plants in Batch and Continuous Treatments of Trace Endocrine Disrupting Chemicals

    A.R. Reis, N. Maruyama, K. Tabei, Y. Sakakibara

    Procs. of 3rd IWA-ASPIRE Conference and Exhibition    2009.11

  • 固体高分子電解質(SPE)膜電極を用いた水電解における酸素消費および水素溶解に関する基礎的研究

    小森 正人, 松谷 裕貴, 秋田 靖典, 榊原 豊

    環境工学論文集   46   137 - 143  2009.11

  • Treatment of Aqueous EDCs by Artificial and Natural Oxidation Processes

    Y. Sakakibara

    WICE (invited lecture)    2009.10

  • Application of life cycle risk assessment (LCRA) of fish to different suburban streams

    Y. Bando, N. Kikuchi, Y. Sakakibara

    Procs. of 3rd IWA-ASPIRE Conference and Exhibition     90 - 91  2009

  • 固体高分子電解質(SPE)膜電極を設置した固定床生物膜反応器による合成地下水の高速水素利用脱窒処理

    小森正人, 榊原豊

    土木学会論文集   65 ( 3 ) 153 - 163  2009

  • Removal of endocrine disrupting chemicals (EDCs) by aquatic plants

    Y. Sakakibara

    Proc. of International Conference on Environmental Science and Technology     #700  2008.07

  • High-rate Hydrogenotrophic Denitrification in a Fluidized-Bed Biofilm Reactor using SPEME,

    M. Komori, Y. Sakakibara

    Water Science and Technology   58 ( 7 ) 1441 - 1446  2008.02  [Refereed]

  • Removal of Trace Environmental Contaminants by Algal Biofilms

    H. Sugiura, N. Kishida, Y. Sakakibara

    IWA Biofilm Technologies Conference   ABSTRACT HANDBOOK   129 - 130  2008

  • Assessing crucial stress to survival of fish in suburban streams

    Y. Sakakibara, A. Nakada

    Water Science and Technology   58 ( 2 ) 445 - 450  2008

  • Removal of Trace Environmental Contaminants by Algal Biofilms

    H. Sugiura, N. Kishida, Y. Sakakibara

    IWA Biofilm Technologies Conference, ABSTRACT HANDBOO     129 - 130  2008.01

  • 尿中の微量有害物質の電気化学的除去に関する研究

    小野大樹, 林 雅樹, 榊原 豊

    環境工学論文集   44   347 - 353  2007.11

  • 低濃度内分泌攪乱物質の電気化学的連続処理に関する基礎的研究

    柏村 斉, 榊原 豊

    環境工学論文集   44   313 - 319  2007.11

  • Electrolytic Treatment of Trace Toxic Substances in Urine

    T. Ono, Y. Sakakibara

    Conference Proceedings, IWA ASPIRE Conference and Exhibition, P107     1 - 6  2007.10

  • Modeling Water Quality and Quantity of Sediments in Small and Medium Size Urban Rivers

    H. Ito, Y. Sakakibara

    Conference Proceedings, 2nd-IWA ASPIRE Conference and Exhibition, P147     1 - 7  2007.10

  • Application of a life cycle risk assessment (LCRA) for fishes to suburban streams

    A. Nakada, Y. Sakakibara

    Conference Proceedings, 2nd-IWA ASPIRE, Conference and Exhibition, P098     1 - 6  2007.10

  • Enhancing hydrogenotrophic denitrification with solid-polymer electrolyte membrane electrode (SPEME

    M. Komori, Y. Sakakibar

    Conference Proceedings, 2nd-IWA ASPIRE, Conference and Exhibition, No.091     1 - 7  2007.10

  • A Mathematical Model for Electrochemical Treatment of Trace Environmental Pollutants

    Y. Sakakibara, M. Komori, H. Kashimura

    Procs. of the 5th International Conference on Sustainable Sanitation     129 - 134  2007.09

  • Electrolytic Treatment of Trace Toxic Substances in Urine

    T. Ono, M. Hayashi, A. Inoue, Y. Sakakibara

    Procs. of the 5th International Conference on Sustainable Sanitation     135 - 143  2007.09

  • Electrochemical Treatment of Trace toxic Substances in Urine

    T. Ono, R. Nagata, Y. Sakakibara

    Procs. of 12th Advanced Oxidation Technologies (AOTs), Pittsburgh, Sep.    2006

  • Comparative Study on Electrolytic Generation from Wastewater by two Different Biofilm-Electrode Reactor

    N. Takako, M. Miyazawa, Y. Sakakibara

    Procs. of 5th IWA World Water Congress and Exhibition, Beijing, China    2006

  • Electrochemical treatment of trace endocrine disrupting chemicals with a three-dimensional electrode system

    R Nagata, M Prosnansky, Y Sakakibara

    JOURNAL OF ADVANCED OXIDATION TECHNOLOGIES   9 ( 1 ) 97 - 102  2006.01  [Refereed]

     View Summary

    The wide pollution of Endocrine Disrupting Chemicals (EDCs) in the aquatic environment is of great concern to aquatic organisms and human health. Previous researches indicated that the main sources of the EDCs were sewage treatment plants (STPs). In this paper, we reported treatment results of synthetic wastewater containing several EDCs by a three-dimensional electrode system. Pt/Ti granular electrodes were used to enlarge the effective surface area of the anode. Concentrations of EDCs were prepared in the range of 1-1000 mu g/l. In batch and continuous treatments, EDCs were successfully removed by the present system. Electric current and recycling flow rate played important roles for removal efficiency and reactor design. Energy consumptions were in the range of 0.1-10 Wh/m(3). Furthermore, a selective removal of EDCs was demonstrated. From these results, we concluded that electrochemical oxidation process using the system has a potential for the treatment of trace EDCs.

  • Enhanced treatment of trace pollutants by a novel electrolytic cell

    Y. Sakakibara, Y. Senda, T. Obanayama, R. Nagata

    Engineering in Life Science   6 ( 6 ) 1 - 5  2006.01

  • A Life-cycle Risk Assessment for Fishes in Streams in Suburban Areas

    T. Aoki, Y. Sakakibara

    Procs. of 10th International Specialist Conference on Watershed and River Basin Management 2005    2005.09

  • Continuous Treatment of Endocrine Disrupting Chemicals with a Three-dimensional Electrode System

    R. Nagata, K. Kashimura, M. Prosnansky, Y. Sakakibara

    Procs. of the 2nd European Conference on Oxidation and Reduction Technologies for Ex-Situ and In-Situ Treatment of Water, Air and Soil    2005.07

  • Direct Oxidation Treatment by a Novel 3-DImensinal Electrolytic Cell Reactor

    Y. Sakakibara, Y. Senda, M. Prosnansky

    Procs. of 1st IWA-ASPIRE (Asia Pacific Regional Group) Conference and Exhibition   4B-3  2005.06  [Refereed]

  • Bio-dehalogenation of PCE

    M. Prosnansky, Y. Hadano, Y. Sakakibara

    Procs. of 1st IWA-ASPIRE (Asia Pacific Regional Group) Conference and Exhibition   1 E-3  2005.06

  • Development of high performance H2 feeder for bioremediation

    T. Nobata, M. Prosnansky, Y. Sakakibara, S. Fukuda

    Water Science and Technology   52 ( 9 ) 259 - 265  2005

  • Development of high performance H2 feeder for bioremediation

    T. Nobata, M. Prosnansky, Y. Sakakibara, S. Fukuda

    Water Science and Technology   52 ( 9 ) 259 - 265  2005  [Refereed]

  • Electrochemical Oxidation of Trace Endocrine Disrupting Chemicals (EDCs) with 3-Dimensional Electrode System

    H. Kashimura, Y. Sakakibara

    Procs. of 11th Advanced Oxidation Technologies (AOTs)    2005

  • A Fundamental Study of PCE by Biofilm-Electrode Reactor

    Y. Hadano, M. Prosnansky, Y. Sakakibara

    Procs. of 1st International Conference on Environmental Science and Technology    2005.01

  • Fundamental Study on Electron Recovery from Wastewater by a Biofilm-Electrode Reactor (BER)

    M. Miyazawa, Y. Sakakibara

    Procs. of 1st International Conference on Environmental Science and Technology    2005.01

  • 水素注入型透過壁による地下水脱窒処理に関する基礎的研究

    土居, 榊原

    環境工学研究論文集   41   119 - 126  2004.11

  • 用排水の電解酸化処理に関する基礎的研究

    榊原, 千田

    環境工学研究論文集   41   221 - 228  2004.11

  • Development of A High- Efficiency H2 Feeder for Bioremediation

    T. Nobata, M. Prosnansky, Y. Sakakibara, S. Fukuda

    Procs. of 4th IWA World Water Congress    2004.09  [Refereed]

  • Application of IWA RWQM No.1 for the Restoration of Polluted Streams in Japan

    R. Kawamoto, Y. Sakakibara

    Procs. of 4th IWA World Water Congress    2004.09

  • A New Electrochemical System for the Removal of Trace Endocrine Disrupting Chemicals

    T. Obanayama, R. Nagata, Y. Sakakibara

    Procs. of 4th IWA World Water Congress, Marrakech    2004.09

  • Enhanced MF Performance by Hybrid Biofilm-Electrode/MF Reactor

    M. Prosnansky, Y. Sakakibara

    Procs. of IWA Specialty Conference-WEMT 2004   2   769 - 774  2004

  • Enhanced Reduction of Heavy Metal Ion by a Novel 3-Dimensional Multi-Electrode System

    Y. Sakakibara, Y. Machida, M. Prosnansky

    Procs. of IWA Asia-Pacific Regional Conference    2003.10

  • A Novel Electrolytic Oxidation Process(EOP) for Treatment of Dilute Solutions

    Y. Senda, Y. Sakakibara

    Procs. of IWA Asia-Pacific Regional Conference    2003.10

  • A Fundamental Study on Phosphate Removal By a Granular Metal Filter

    K. Tashiro, Y. Sakakibara

    Procs. of The First International Symposium on Southeast Asian Water Environment   1   382 - 386  2003.10

  • In Situ Auto-trophic Denitrification with Continuous Injection of H2 Gas

    T. Doi, Y. Sakakibara

    Procs. of In Situ and On Site Bioremediation    2003.06

  • A bio-electrochemical reactor coupled with adsorber for the removal of nitrate and inhibitory pesticide

    Z Feleke, Y Sakakibara

    WATER RESEARCH   36 ( 12 ) 3092 - 3102  2002.07  [Refereed]

     View Summary

    In this study, the treatment characteristics of nitrate and toxic pesticide by a combined bioelectrochemical reactor (BER)/adsorption process was investigated. Experimental results showed that the disappearance of NO3- in BER was in accordance with the applied current. NO2- was not detected in the effluent, but the production of NO was increased with increasing IPT loading. In the presence of IPT, up to 30% of the nitrate nitrogen consumed was converted to N2O, while more than 95% converted to N-2 in the absence of IPT. In adsorption column, IPT was efficiently removed onto either granular activated carbon or silicone resin so as to meet the guideline value (40 mug/l) and to reduce the N2O accumulation. A simplified kinetic model that considers the sequential reduction of nitrate and inhibition of the N2O reduction step by pesticide as well as Langmuir adsorption isotherm was developed and used to evaluate the process performance. Theoretically predicted effluent concentrations were in good agreement with the observed results for nitrate, nitrite, N2O, N-2 and IPT. It was considered that high removal performance of nitrate and pesticide by the combined process is attributable to high affinity of adsorbates for IPT in comparison with relatively large inhibition constant (K-i). (C) 2002 Elsevier Science Ltd. All rights reserved.

  • High-Rate Denitrification and SS Rejection by Biofilm-Electrode Reactor (BER) Combined with Microfiltration

    M. Prosnansky, Y. Sakakibara

    Water Research   36   4408 - 4418  2002  [Refereed]

  • A Hybrid Biofilm Reactor for Nitrate and Pesticide Removal

    Y. Sakakibara, Z. Feleke, T. Katahira

    Water Science and Technology   12 ( 2 ) 35 - 45  2002  [Refereed]

  • Biobarrier Comprised of Soil and BAC, In Situ and On-Site Bioremediation

    Y. Sakakibara, D. Kaminura

    Bioaugmentation, Biobarriers, and Biogeochemistry, Lesson, Alleman, Alvarez, and Magar (Eds.), Battelle Press   6 ( 8 ) 113 - 120  2001.06

  • Biobarrier Comprised of Soil and BAC, In Situ and On-Site Bioremediation

    Y. Sakakibara, D. Kaminura

    Bioaugmentation, Biobarriers, and Biogeochemistry, Lesson, Alleman, Alvarez, and Magar (Eds.), Battelle Press   6 ( 8 ) 113 - 120  2001.06  [Refereed]

  • 電極を用いた新しい原位置脱窒法の浄化性能に関する実験的並びに理論的研究

    日下, 榊原

    土木学会論文集   671 ( Ⅶ-18 ) 59 - 71  2001

  • A novel multi-electrode system for electrolytic and biological water treatments: Electric charge transfer and application to denitrification

    Y. Sakakibara, T. Nakayama

    Water Research   35 ( 3 ) 768 - 778  2001

     View Summary

    A novel multi-electrode system is proposed for electrolytic and biological water treatments. The multi-electrode system is comprised of multiple working electrodes and their counter electrode, where electric current or potential applied to each electrode is controlled independently. Experimental result for different electrolyte solutions showed that electric charge in the system was efficiently carried by dissociative electrolytes such as carbonate ions. This transfer mechanism is regarded as being effective both in keeping pH level around neutrality and in passing certain amounts of electric current especially in dilute solutions such as groundwater and surface water. A long-term (over 500 days) experiment also showed the enhanced and stable denitrification performance of biofilm-electrode reactor (BER) equipped with the multi-electrode system, comparing to former BERs. This superior performance was thought to be attributable to large effective surface area of electrode, the charge transfer mechanism by dissociative electrolyte, and the formation of highly reducing (or oxidizing) zones. From these results, we conclude that the multi-electrode system is useful for electrolytic and biological treatments of groundwater and surface water.

    DOI PubMed

  • High-rate denitrification in biofilm-electrode reactor combined with microfitration

    M Prosnansky, Y Sakakibara

    BIOREMEDIATION OF INORGANIC COMPOUNDS   6 ( 9 ) 201 - 207  2001  [Refereed]

     View Summary

    In this study, a novel multi-cathode biofilm-electrode reactor (BER) combined with micro-filtration (MF) was investigated using a laboratory-scaled experimental apparatus for on-site, remediation of nitrate-contaminated groundwater. In BER, autotrophic denitrification takes place by applying electric current. Extended surface area of multi-electrodes enables BER to operate at high electric currents with low current densities. MF membranes with plate modules and pore size of 0.2 mum were chosen for the final rejection of suspended solids (SS) escaping from BER. Experimental results demonstrated that it was possible to operate the multi-cathode BER with high denitrification rates and low hydraulic retention time. (HRT = 20 min). The overall performance was enhanced by 10 to 60 times in comparison with those in former studies. MF membranes successfully rejected bacteria escaping from BER, so that effluent concentration of SS was below 1 mg-SS/L throughout the experiment. The present BER/MF process is considered applicable for on-site remediation of nitrate-polluted groundwater.

  • Performance and Function of Johkasou System

    Y. Sakakibara

    Procs. of the Seminar on Johkasou Management     1 - 10  2000.11

  • Nitrate and Pesticide Removal by a Combined Bioelectrochemical/Adsorption Process

    Z. Fleke, Y. Sakakibara

    Procs. of 1st World Congress of IWA   Book 2   450 - 457  2000.07

  • Effect of Pesticide on Denitrification in BER

    Z. Feleke, Y. Sakakibara

    Procs. of ISEB2000     9 - 14  2000.07

  • Denitrificaton and Oxygenation Process Equipped with a Multi-Electrode System

    Y. Sakakibara, T. Nakakayama

    CD Rom of 1st World Congress of IWA   L243  2000.07

  • In situ autotrophic denitrification using electrode under oligotrophic conditions

    Y Sakakibara, J Kusaka

    BIOREMEDIATION OF METALS AND INORGANIC COMPOUNDS   5 ( 4 ) 73 - 78  1999  [Refereed]

     View Summary

    The feasibility of an in situ autotrophic denitrification process was investigated under oligotrophic conditions. Electrodes were embedded in laboratory-scale sandy aquifers and H-2, gas was produced through the electrolysis of water for enhancing autotrophic denitrification. In experiment, a groundwater containing about 20 mg-N/L of NaNO3, and no electron donor was fed continuously, while trace nutrients such as phosphate were not injected. Experimental results showed that, when carbon electrodes were embedded in a direction perpendicular to groundwater flow, the complete and stable denitrification was achieved over one year without clogging problem. Denitrification rate varied depending on applied current. Electric power requirement was in the range of 0.03 similar to 0.09 kWh/g-N. This energy requirement corresponded to about 8 % of total energy obtained from a wind or solar power generation at some places in Japan.

  • 生物活性炭添加土壌による温室効果ガス(CH4, N2O)の放出制御に関する基礎的研究

    榊原, 田中, 吉田

    土木学会論文集   629 ( Ⅶ-12 ) 27 - 36  1999

  • Selective reduction of nitrate to nitrogen gas in a biofilm-electrode reactor

    Z Feleke, K Araki, Y Sakakibara, T Watanabe, M Kuroda

    WATER RESEARCH   32 ( 9 ) 2728 - 2734  1998.09  [Refereed]

     View Summary

    Microbial denitrification and the occurrence of neutralization in a denitrifying biofilm-electrode reactor (BER) using an amorphous carbon anode has been experimentally demonstrated. In this study, the BER was operated over one year and measurements of influent and effluent ionic species were made at different electric currents to evaluate the predominant electrochemical and biological reactions. The ionic species measured were NO3-, NO2-, SO42--, Cl-, PO43-, NH4+, Na+, K+, Ca2+ and Mg2+, most of which are common constituents of surface water or groundwater, Concentrations of Na+, K+, SO42- and Cl- were almost the same in the influent and effluent. Removal efficiency of nitrate (NOS) varied in the range of about 0 to 100%, depending on the electric current. Complete denitrification to Nz gas was readily achieved without accumulation of NO2-, N2O and NH4+. The concentration of Ca2+ and Mg2+ decreased due to deposition onto the surface of the electrode, but the calculation result from the solubility equilibrium of CaCO3, MgCO3 and CaMg(CO3)(2) using the saturation index (SI) showed that the deposition could be hampered by the electrochemical neutralization in the reactor. Furthermore, the deposited calcium and magnesium could be redissolved immediately by changing the polarity of electrodes. From these results, it is concluded that a highly selective reduction of nitrate is operationally possible in the present BER, hence this process is a feasible alternative for the treatment of various nitrate-contaminated water. (C) 1998 Elsevier Science Ltd. All rights reserved.

  • The Denitrification and Neutralization Performance of an Electrochemically Actirated Biofilm Reactor Used to Treat Nitrate-Contaminated Groundwater

    Y. Sakakibara, K. Araki, T. Watanabe, M. Kuroda

    Wat. Sci. Tech.   31 ( 6 ) 61 - 68  1997.06  [Refereed]

  • An In-Situ Denitritication with an Application of Electric Current

    Y. Sakakibara, K. Ihara, T. Tanaka, T. Watanabe, M. Kuroda

    Procs. of 6th IAWQ Asia-Pacific Regional Conference   6   234 - 244  1997

  • 生物膜電極を用いた窒素除去に関する研究

    榊原, 渡辺, 黒田

    浄化槽研究   9 ( 2 ) 3 - 9  1997

  • Performance of Denitrification and Newtralization of Electrochemically-Actirated Biofilin Reactors Treating Nitrate-Contaminated Groundwater(共著)

    Y. Sakakibara, K. Araki, T. Watanabe, M. Kuroda

    3rd International IAWQ Special Conference on Biofilm Systems, Copenhagen    1996.08

  • An In-situ Denitrification of Nitrate-Contaminated Groundwater using H<SUB></SUB> as an External Electron Donor(共著)

    Y. Sakakibara, K. Ihara, T. Watanabe, M. Kuroda

    Proceedings of the IASTED International Conference-ADVANCED TECHNOLOGY IN THE ENVIRONMENTAL FIELD     116 - 120  1996

  • 電極を用いた硝酸汚染地下水の原位置(In Situ)脱窒法に関する研究

    榊原, 田中, 井原, 渡辺, 黒田

    環境工学研究論文集   32/,407-415   407 - 415  1995.11

  • Modeling of Electrochemicolly-Actiroted Denitrifying Biofilms

    Y. Sakakibara, J. R. V. Flora, M. T. Suidan, M. Kuroda

    Water Res.   28 ( 5 ) 1077 - 1086  1994.05  [Refereed]

  • NUMERICAL MODELING OF A BIOFILM-ELECTRODE REACTOR USED FOR ENHANCED DENITRIFICATION

    JRV FLORA, MT SUIDAN, S ISLAM, P BISWAS, Y SAKAKIBARA

    WATER SCIENCE AND TECHNOLOGY   29 ( 10-11 ) 517 - 524  1994  [Refereed]

     View Summary

    The enhancement of biological denitrification using a biofilm-electrode reactor (BER) is demonstrated. Removal efficiencies greater than 98% can be achieved. At electric currents in excess of 20 mA, the rate of denitrification within the BER is reduced due to hydrogen inhibition. A detailed steady-state biofilm model is developed taking into account hydrogen inhibition kinetics, the diffusion of neutral and ionic species, the effects of the applied current on the diffusion of ions, gas production within the biofilm, and the presence of a phosphate buffer and a mass transfer boundary layer. The biofilm model is coupled to a model of a completely stirred tank reactor (CSTR). The models are in excellent agreement with the experimental results when the applied electric current is between 0 and 20 mA. The results of the reactor model qualitatively predict the performance of the BER at currents greater than 20 mA using a hydrogen inhibition constant of 10(-4) M.

  • MEASUREMENT OF MASS-TRANSFER COEFFICIENTS WITH AN ELECTROCHEMICAL METHOD USING DILUTE ELECTROLYTE-SOLUTIONS

    Y SAKAKIBARA, JRV FLORA, MT SUIDAN, P BISWAS, M KURODA

    WATER RESEARCH   28 ( 1 ) 9 - 16  1994.01  [Refereed]

     View Summary

    An electrochemical method for measuring mass transfer coefficients using dilute electrolyte solutions is described. Oxidation-reduction potential measurements are used to determine the limiting current density. A mathematical model taking into account the diffusion and migration of the various electrolyte species was developed to evaluate the mass transfer coefficient. The range of the Sherwood numbers obtained with the present method were of the same order of magnitude as those obtained from classical mass transfer studies. The proposed method and the analytical procedure is applicable to electrochemical bioreactors where the use of excess electrolytes is not recommended.

  • DENITRIFICATION AND NEUTRALIZATION WITH AN ELECTROCHEMICAL AND BIOLOGICAL REACTOR

    Y SAKAKIBARA, K ARAKI, T TANAKA, T WATANABE, M KURODA

    WATER SCIENCE AND TECHNOLOGY   30 ( 6 ) 151 - 155  1994  [Refereed]

     View Summary

    Denitrifying microorganisms were immobilized with a sodium alginate gel on a cathode electrode, and electric current was applied using a carbon electrode as the anode. Biological reductions of nitrate through the use of H-2 at the cathode and formations of inorganic carbons at the anode were observed. Experimental results showed that oxidation of carbon electrode to CO2 was favorable for developing anoxic conditions and to neutralize alkalinity formed during denitrification. Several volts of potential was needed to operate the reactor.

  • ELECTRIC PROMPTING AND CONTROL OF DENITRIFICATION

    Y SAKAKIBARA, M KURODA

    BIOTECHNOLOGY AND BIOENGINEERING   42 ( 4 ) 535 - 537  1993.08  [Refereed]

     View Summary

    The effectiveness of a denitrification process which is driven and controlled by an electric current is demonstrated. Denitrifying microorganisms were immobilized on a carbon electrode and hydrogen was produced through the electrolysis of water. The hydrogen was utilized for the reduction of nitrate to N2. The denitrification rate was a linear function of the electric current, and it was shown that about 1 mol of electron reduces 0.2 mol of nitrate to N2 gas. These results exhibit that the proposed process is simple and feasible, especially for the treatment of low-strength nitrate solutions. (C) 1993 John Wiley & Sons, Inc.

  • 草木ダム湖の富栄養化に関する研究(共著)

    黒田, 折原, 下斗米, 榊原

    衛生工学研究論文集   28   51 - 58  1992.11

  • Preservation Characteristics of Facultative Anaerobes Immobilized with Gels and Porous Solid Supports. (共著)

    Y. Sakakibara, M. Kuroda

    Procs. of Asian WATERQUAL'91     221 - 226  1991

  • EVALUATION OF COD REMOVAL PERFORMANCE BASED ON ORGANIC-ACID DECOMPOSITION IN AN ANAEROBIC FIXED-BED REACTOR

    M KURODA, Y SAKAKIBARA

    WATER SCIENCE AND TECHNOLOGY   24 ( 5 ) 111 - 121  1991  [Refereed]

     View Summary

    COD removal performance in an anaerobic fixed bed reactor(AAFBR), which treats soluble organic matter, was investigated theoretically by using a simplified biofilm model. The COD removal rate was assumed to be controlled by the decomposition rates of volatile fatty acids such as acetate, propionate and butyrate. The simplified biofilm model took into consideration the effects of intrabiofilm and interbiofilm substrate diffusion rates on substrate biodegradation rates. The COD removal rates in AAFBR were evaluated for various operating conditions by using known kinetic parameters. The calculated results show that the COD removal rates are not affected by adhered biomass provided that the biomass is more than about 4 mg-C/cm2, and vary with temperature, bulk liquid substrate concentrations and the bulk liquid flow rates which are in the range 0.01 approximately 1 m/hr. Relations between allowable COD loading rates and packing diameters were shown schematically for different bulk liquid flow rates.

  • Affinity of Carbon Material to Methanogenic Bacteria(共著)

    A. Oya, Y. Tosaka, T. Asano, Y. Sakakibara, M. Kuroda, S. Otani

    J. Mater. Sci.   9   693 - 695  1990  [Refereed]

  • Simplified Equations for Effectiveness Factors in Anaerobic Biofilms

    M. Kuroda, Y. Sakakibara, C. R. Escarela

    J. Environ. Eng. (ASCE)   115/6 ( 6 ) 1123 - 1139  1989.06

  • Methanogenic Bacteria Adhered to Solid Supports(共著)

    M. Kuroda, M. Yuzawa, Y. Sakakibara, M. Okamura

    Wat. Research   22/5,653-656  1988  [Refereed]

  • Theoretical Consideration on the Treatment Characteristics of Volatile Fatty Acids in Completely Mixed Anaerobic Biofilm Reactors(共著)

    Y. Sakakibara, M. Yuzawa, M. Kuroda

    Procs. of JSCE   387/2-8   291 - 299  1987.08

▼display all

Books and Other Publications

  • 排水汚水処理技術集成

    榊原 豊

    NTS  2007.05 ISBN: 9784860431457

  • 環境工学公式・モデル・数値集

    榊原 豊

    土木学会  2004.01 ISBN: 4810604217

Industrial Property Rights

  • 水処理方法及び水処理装置

    榊原 豊

    Patent

  • 高効率電極配列よりなる電解水素供給装置とそれを用いた水処理方法

    榊原 豊

    Patent

  • オキシダント溶液の生成装置

    4013711

    榊原 豊

    Patent

Awards

  • 環境工学研究フォーラム奨励賞

    1996  

Research Projects

  • Advanced Activated Sludge Process

    Project Year :

    2020.07
    -
    2023.03
     

  • R & D on advanced Phyto-remediation process

    Project Year :

    2015.04
    -
    2018.03
     

     View Summary

    Remediation performance of persistent organic pollutants (POPs) by Phyto-Fenton process was investigated in laboratory and field experiments. By using fine iron particles, such as colloidal ferric hydroxides and magnetite nanoparticles, and rice grasses, pentachlorophenol could be removed within two months. Moreover, the process could be successfully applied to an actual site contaminated with DDTs in Vietnam, demonstrating the process would be a feasible alternative to conventional phytoremediation processes with low cost and high performance. A further study will be needed to evaluate the process performances in different POPs-contaminated sites

  • 高性能ファイトリメディエーション法の研究開発

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

    Project Year :

    2015
    -
    2017
     

  • R & D on a novel electrochemical AOP with simple operation

    Project Year :

    2012.04
    -
    2015.03
     

     View Summary

    Treatment performances of a novel electrochemical advanced oxidation process operated by an application of electric current were studied experimentally and theoretically. From experimental results, it was demonstrated that by using electrolytic cells consisting of SnO2 anode, SPE membrane and granular cathodes equipped in a pipe line, pollutants such as antibiotics, synthetic and natural estrogens and constituents in tertiary effluent from sewage treatment plant were purified effectively by OH radicals generated through the reductions of ozone produced from anode. A mathematical model representing the performances was constructed and verified with experimental data

  • Study on Bio-Fenton process

    Project Year :

    2011.04
    -
    2014.03
     

     View Summary

    A biological Fenton (Bio-Fenton) process using iron compounds and aquatic plants in constructed wetlands was proposed to decompose refractory and toxic pollutants in water and wastewater. Batch and semi-continuous experimental results demonstrated that pollutants such as endocrine disrupting compounds (EDCs), pentachlorophenol (PCP) and dye could be decomposed by Bio-Fenton process. Some tropical plants possess higher endogenous hydrogen peroxide (H2O2) in comparison with temperate plants; therefore, the application of Bio-Fenton process may be more preferable in tropical than temperate regions. In addition, Bio-Fenton process was affected by iron compounds, where fine particles of magnetite were a possible iron compound with smaller stress to aquatic plants. Moreover, a procedure to identify Bio-Fenton reaction with fluorescent reagent is effective in screening appropriate iron compounds

  • 操作性に優れた簡易型電気化学的促進酸化法の研究開発

    科学研究費助成事業(早稲田大学)  科学研究費助成事業(基盤研究(B))

    Project Year :

    2012
    -
    2014
     

     View Summary

    操作管理が極めて容易な電気化学的処理法の設計・操作条件に関する基礎資料を得るために、前年度の結果に基づいて、陽極にSnO2電極、陰極に粒状および繊維状電極を用いた電解槽を作製し、異なる操作条件下の処理性能について実験的並びに理論的検討を行った。その結果、以下のような知見を得た。
    1)OHラジカルプローブとしてp-クロロ安息香酸(p-CBA)を用いた連続処理実験を異なる電極面積、通電条件、処理時間で行った結果、本法は安定してp-CBAを除去できることがわかった。特に、陰極の比表面積を大きくすることにより、処理時間を数分程度に減少させることができた。
    2)抗生物質(テトラサイクリン)、天然および合成エストロゲン(E1, E2, EE2)等を含む異なる合成排水に対する連続処理実験から、本法は対象汚染物質を効率良く除去できることがわかった。しかしながら、抗生物質の処理実験では全有機性炭素(TOC)を十分に除去できなかった。このことは、処理の過程で中間生成物質が生成されていることを示している。一方、エストロゲン類は電極表面上で酸化・ポリマー化することにより除去されるが、オゾン存在下で極性転換後に還元するとほぼ完全に分解され、同時に電極が再生されることが分かった。
    3)1)の実験結果に基づいて、オゾン生成、オゾン還元およびOHラジカル生成の各速度を表わす数学モデルを構築した。本モデルにより、異なる設計・操作条件に対するOHラジカル生成等を予測することができる。

  • Study on Bio-Fenton process

    Project Year :

    2011
    -
    2013
     

     View Summary

    A biological Fenton (Bio-Fenton) process using iron compounds and aquatic plants in constructed wetlands was proposed to decompose refractory and toxic pollutants in water and wastewater. Batch and semi-continuous experimental results demonstrated that pollutants such as endocrine disrupting compounds (EDCs), pentachlorophenol (PCP) and dye could be decomposed by Bio-Fenton process. Some tropical plants possess higher endogenous hydrogen peroxide (H2O2) in comparison with temperate plants; therefore, the application of Bio-Fenton process may be more preferable in tropical than temperate regions. In addition, Bio-Fenton process was affected by iron compounds, where fine particles of magnetite were a possible iron compound with smaller stress to aquatic plants. Moreover, a procedure to identify Bio-Fenton reaction with fluorescent reagent is effective in screening appropriate iron compounds.

  • 環境微量有害物質の選択的分解処理に関する基礎的研究

    科学研究費助成事業(早稲田大学)  基盤(C)

    Project Year :

    2002
    -
    2003
     

     View Summary

    Pt/Ti粒状電極を充填した3次元電解槽による環境微量有害物質の選択的処理性能について連続実験より検討を行った.ここで、環境微量物質として環境ホルモン性が疑われているペンタクロロフェノール(PCP)を主として用いた.また、流入PCP濃度は1mg/l, HRT=1.2hとした.その結果、微弱な直流電流を電解槽に通電することにより処理水のPCP濃度はほぼ0.01mg/l前後に低下し、長期間(70日以上)安定した処理が可能であることがわかった.PCP処理に関してこれまでに報告されている物理化学処理、化学処理並びに生物処理の各処理データと本研究結果とを比較すると、本電解法は特に低い濃度域でも効率的な処理が可能であることがわかった.電解に要したエネルギーは数Wh/m3程度であり、下水処理に要するエネルギー量より2桁程度低かった.さらに、流入水中にフミン物質が存在する場合において処理速度が大きく低下することはなかった.このような傾向は他の環境微量有害物質(17βエストラジオール、ジクロロフェノール、4tオクタチフェノール、ビスフェノールA)についても同様であった

  • 環境微量有害物質の選択的分解処理に関する基礎的研究

    科学研究費助成事業(早稲田大学)  基盤(C)

    Project Year :

    2002
    -
    2003
     

     View Summary

    Pt/Ti粒状電極を充填した3次元電解槽による環境微量有害物質の選択的処理性能について連続実験より検討を行った.ここで、環境微量物質として環境ホルモン性が疑われているペンタクロロフェノール(PCP)を主として用いた.また、流入PCP濃度は1mg/l, HRT=1.2hとした.その結果、微弱な直流電流を電解槽に通電することにより処理水のPCP濃度はほぼ0.01mg/l前後に低下し、長期間(70日以上)安定した処理が可能であることがわかった.PCP処理に関してこれまでに報告されている物理化学処理、化学処理並びに生物処理の各処理データと本研究結果とを比較すると、本電解法は特に低い濃度域でも効率的な処理が可能であることがわかった.電解に要したエネルギーは数Wh/m3程度であり、下水処理に要するエネルギー量より2桁程度低かった.さらに、流入水中にフミン物質が存在する場合において処理速度が大きく低下することはなかった.このような傾向は他の環境微量有害物質(17βエストラジオール、ジクロロフェノール、4tオクタチフェノール、ビスフェノールA)についても同様であった

  • DEVELOPMENT OF NOVEL WATER TREATMENT PROCESSES USING MULTI-ELECTRODE SYSTEM

    Project Year :

    1999
    -
    2000
     

     View Summary

    Three novel processes for the treatments of heavy metal (Cu^<2+>) ion, nitrate, and phosphorous compounds, respectively, were proposed and their performances were studied experimentally and theoretically.In the process for heavy metal ion removal, it was found that removal efficiency of a model metal ion (Cu^<2+>) was enhanced comparing with former electrolytic process, because electric current was effectively utilized for the metal reduction on the cathode surface (i.e. Cu^<2+> to Cu) in the multi-electrode system. This enhanced performance is attributable to smaller electric current density below limiting current density. Furthermore, it was shown that the multi-electrode system consisting of GAC also increased bio-electrochemical denitrification rate several times, in comparison with former BER studies.Moreover, the multi-electrode system was successfully applied to a novel phosphorous removal process, where phosphorus precipitation occurred with no addition of chemicals and was facilitated by a unique alkaline zone-formation in the multi-electrode system. This invention was applied as domestic, US and EU patents

  • DEVELOPMENT OF NOVEL WATER TREATMENT PROCESSES USING MULTI-ELECTRODE SYSTEM

    Project Year :

    1999
    -
    2000
     

     View Summary

    Three novel processes for the treatments of heavy metal (Cu^<2+>) ion, nitrate, and phosphorous compounds, respectively, were proposed and their performances were studied experimentally and theoretically.
    In the process for heavy metal ion removal, it was found that removal efficiency of a model metal ion (Cu^<2+>) was enhanced comparing with former electrolytic process, because electric current was effectively utilized for the metal reduction on the cathode surface (i.e. Cu^<2+> to Cu) in the multi-electrode system. This enhanced performance is attributable to smaller electric current density below limiting current density. Furthermore, it was shown that the multi-electrode system consisting of GAC also increased bio-electrochemical denitrification rate several times, in comparison with former BER studies.
    Moreover, the multi-electrode system was successfully applied to a novel phosphorous removal process, where phosphorus precipitation occurred with no addition of chemicals and was facilitated by a unique alkaline zone-formation in the multi-electrode system. This invention was applied as domestic, US and EU patents.

  • Development of a H_2 utilizing In-situ denitrification system used for nitrate-contaminated groundwater.

    Project Year :

    1996.04
    -
    1997.03
     

     View Summary

    A novel in-situ denitrification systemis proposed for treating nitrate in groundwater in shallow aquifers. In the system, H_2 is used as an electron donor which is produced from water by passing electric current to electrodes embedded in aquifer. Laborratory-scale experiments showed that stable and complete denitrification could be achieved over one year without clogging problem. That is, the Present in-situ denitrification process is suitable for treating polluted groundwater under oligotrophic conditions.To enhance the denitrification rate, the effect of the electrode configurations was investigated. The denitrification rates were affected by the configuration especially when the anode and cathode were installed parallel to the groundwater flow direction because pH in the aquifer was increased by the polarization of electrolytic constituents. On the other hand, a mathematical model describing the in-situ system is developed and compared with the experimental results. The denitrification performances calculated at different electric currents were very similar to experimental results. Finally, apossibility of utilizing natural wind and solar energies were investigated in three case studies. A combined in-situ system with wind (or solar) Power generation is considered feasible in some area in Japan

  • Development of a H_2 utilizing In-situ denitrification system used for nitrate-contaminated groundwater.

    Project Year :

    1996.04
    -
    1997.03
     

     View Summary

    A novel in-situ denitrification systemis proposed for treating nitrate in groundwater in shallow aquifers. In the system, H_2 is used as an electron donor which is produced from water by passing electric current to electrodes embedded in aquifer. Laborratory-scale experiments showed that stable and complete denitrification could be achieved over one year without clogging problem. That is, the Present in-situ denitrification process is suitable for treating polluted groundwater under oligotrophic conditions.To enhance the denitrification rate, the effect of the electrode configurations was investigated. The denitrification rates were affected by the configuration especially when the anode and cathode were installed parallel to the groundwater flow direction because pH in the aquifer was increased by the polarization of electrolytic constituents. On the other hand, a mathematical model describing the in-situ system is developed and compared with the experimental results. The denitrification performances calculated at different electric currents were very similar to experimental results. Finally, apossibility of utilizing natural wind and solar energies were investigated in three case studies. A combined in-situ system with wind (or solar) Power generation is considered feasible in some area in Japan

  • A Study on Simultaneous Treatment of Organic Matter and Nitrate with a Biofilm Consisting of Methane Fermentative Bacteria and Denitrifying Bacteria

     View Summary

    Methane fermentative bacteria and denitrifying bacteria were enriched with a synthetic medium, and a biofilm was formed on solid support surfaces in a completely mixed reactor. In the medium, glucose, peptone and sodium nitrate were used as carbon and nitrogen sources.By using the biofilm reactor, characterisitcs of the anaerobic treatment of an aqueous mixture of organic matter and nitrate were studied experimentally, and effects of the C/N ratio on removal efficiencies of TOC and nitrate and effluent characteristics were examined in batch mode and/or continuous operations.Organic matter and nitrate were removed simultaneously in the anaerobic biofilm reactor, in which methane fermentative bacteria and denitrifying bacteria symbiosed. In the simultaneous treatment, acetate which is an intermediate metaboric product in methane fermentation were effectively utilized by denitrifying bacteria as hydrogen donor. Competition between methanogens and denitrifying bacteria existed on the utilization of acetate. Removal efficiencies of TOC and nitrogen in continuous operations were greater than 94% and 65%, respectively, provided that the ratio of C and N is larger than 2. Both values of ORP and pH increased with the increment of nitrate concentration. Under high nitrate loading conditions, methane gas production decreased.The degradation rate of NO_3^- was varied with the concentration of NO_3^-. The equation of the degradation rate was expressed with a Monod type equation. The maximum specific degradation rate constant and half velocity constant were 4.6 mg-N/mg-C.D and 10 mg-C/l provided by using acetate as hydrogen donor. The value of the half velocity constant is about half of that for the degradation of acetate by methanogenic bacteria

  • Simplified Estimation Procedure of Excessive Growth of Algae in Lake

     View Summary

    Excessive growth of Phormidium tenue and musty odor due to it have been observed recent years in lake Kusaki located In Gunma, Japan. Variations of the algal growth and water qualities in the lake were observed for two years, and investigated a possibility of forecasting the excessive growth from a simple ecological model with known parameters which were generally reported in former studies. The field surveys showed that distributions of temperature and nutrient concentrations were significant in the vertical direction but not in horizontal, therefore, a vertical one-dimensional mathematical model consisted of the heat and mass balance equations was used. The model fairly evaluated the seasonal changes in water qualities of TH, TP, TOC and Chl. a as well as the thermal stratification and turnovers. Although some modifications of the model should be necessary to evaluate the P. tenue population exactly, the growth pattern which had two peaks in early and late summer in 1990 and 1991 were estimated reasonably well by assuming a maximum specific growth rate of 2.5 d^<-1>

  • 地下水硝酸イオンの有機物無添加脱窒処理に関する研究

     View Summary

    電位分布が均一となる円筒型リアクターを作製し、外部(ステンレス)円筒を陰極、炭素棒を陽極としてそれぞれ同心円状に配置して用い、微生物を固定した場合としない場合とで種々の操作条件に対する処理水質を比較・検討した。また、電極系内のイオン移動に対する理論的解析を併せて行い、以下の結果を得た。1.炭素電極を用いることにより、陽極での酸素生成が主に二酸化炭素の生成に変わる。したがって、リアクター内部のORPは-200mV以下の嫌気状態となり、+100〜200mV前後の地下水の処理に際しても脱窒反応が進行しやすい条件となる。2.通電により陰極表面で生成される水素は脱窒反応の電子供与体として利用され、地下水中の硝酸イオンが除去される。硝酸除去量はこれまでの実験条件では電流値が大きいほど大きかった。また、硝酸イオンの除去に伴うpH上昇は1)の陽極における二酸化炭素(及び重炭酸イオン)の生成によって抑制され、結果的に処理水は中和される。電極系内の物質移動に対する理論的検討から、電解質濃度が種々変化した場合の系内電位分布、pH分布、硝酸イオンの移動速度、脱窒速度等の変化量を求めた。特に、無機炭素濃度が数mMになると、脱窒菌固定電極系内のpHはその緩衝作用によってpH10前後から中性付近の値となる。なお、本処理法の最適設計・操作条件については、電極の消費電力量を含めて現在検討中である

  • Development of a simple nitrate removal reactor using biofilm-electrode.

     View Summary

    Denitrification rates of a biofilm-electrode system were first analyzed based on a mathematical biofilm model. The model takes into cinsideration the mass transfer rates in the electric field, biological reaction rates, and electrochemical reaction rates. Calculation results from the model showed that the response of the denitrification rates to applied electric current can be divided into three regions ; linear, and declined regions. From a view point of process design and control as well as a long term performance of laboratory-scale reactors, the biofilm-electrode system can be operated in the linear region. On the other hand, a novel multi-polar electrode system using metal electrodes was developed for enhanced denitrification and a multi biofilm electrodes reactor (Multi BER) was designed and constructed. Continuous experiments with the Multi BER demonstrated that nitrate in groundwater was stably and quickly removed by an application of electric current and at the same time the treated water was aerated by oxygen produced from anode. Furthermore, it was also demonstrated that nitrate and pesticide were removed concurrently by BER but other major constituents such as SO_4^<2->, Cl^-, and Ca^<2+> were almost the same in the influent and effluent

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Specific Research

  • 高性能ファイトリメディエーション法の適用に関する研究

    2018   Vo Huu Cong, Trần Đình Trinh, Dao Thi Nhung

     View Summary

    ファイトフェントン法の浄化性能を向上させる方法について実験的検討を行った。すなわち、植物の自己防御機能であるオキシダティブバースト反応を利用することによって、本法の浄化性能が向上する可能性があることがわかった。また、ベトナムのハーディン省、ナムディン省およびバクニン省のPOPs汚染サイトを調査し、現状の汚染状況、修復技術およびこれらの問題点等に関する基礎資料を得た。

  • 浮遊植物を用いた新しい環境技術に関する研究

    2010  

     View Summary

    これまでの研究からほとんどの水生植物は環境ホルモン(EDCs)等の微量有害物質を浄化できることを明らかにしている。本研究ではEDCsの浄化過程を解明するために、ビスフェノールA(BPA),ノニルフェノール(NP)、エストロゲン(E2)等を用い、異なる植物から抽出したペロオキシダーゼ(PO)、ラッカーゼ(LA)、グルタチオン転化酵素(GTS)、ポリフェノールオキシダーゼ(PPO)による浄化実験を行った。約8種類の植物に対する結果から、環境ホルモン除去に関わる主要な酵素はPOであり、植物内に生成される過酸化水素により、EDCs + H2O2 →生成物となり液中から除去されることがわかった。POの次に重要な酵素はPPOであった。また、植物体内の過酸化水素を用いて、生物学的フェントン反応を進行させ、ペンタクロロフェノール等の難分解性有害物質を分解できることを明らかにした。また、固液分離が容易な浮遊性植物(ウキクサ)を用い、異なる培養条件のタンパク質、グルコース等を分析した。その結果、ウキクサはたんぱく質含量が高く、飼料としての利用可能が示唆された。

  • 河川に生息する魚類のライフサイクルリスクアセスメントに関する調査研究

    2010  

     View Summary

     現在開発中のライフサイクルアセスメント(LCRA)を河川復元事業が実施されている2カ所の中小河川に適用し、生息可能な淡水魚種を予測して実測結果と比較すると共に、魚類生息環境の改善の視点から復元事業の有効性等について検討した。その結果、里川に再生する浄化施設では、LCRAの予測結果と実際の生息魚類とは高精度(約9割)で一致した。復元施設の設置により、生息魚種および生息数が増加したが、この原因はLCRAより、産卵場所および避難場所が新たに創造されたことによると考えられた。 一方、都市下水の処理水を導入している河川では、LCRAの予測結果と実際の生息魚類は6割程度であまり良く一致しなかった。その多くはLCRAの予測結果が生息可能であるが、実際には当該魚種が生息していないケースが多かった。このことは下水処理水中に何らかのストレス因子が含まれていることを示唆している。また、冬季に下水処理水の導入により水温が数度上昇することがわかった。これらについては今後更に検討する必要がある。

  • 河川に生息する魚類のライフサイクルリスクアセスメントに関する調査研究

    2009  

     View Summary

     魚類のライフサイクルリスクアセスメントを実施する場合、対象とする魚類の生息域とライフステージ毎のリスクの評価が重要になる。これまでの研究から都市河川に生息する淡水魚15種に及ぼす8つの主要ストレスおよびその応答を明らかにした。本研究では日本に存在する普通種であるオイカワを異なる河川で採捕し、既往文献より得た8種類のマイクロサテライトマーカーを用いて遺伝的多様性を比較し、生息域の特定に本分子マーカーが適用できるか否かについて検討した。 対象河川は埼玉県本庄市のM, K, O川である。フィールド調査及び遺伝子分析の結果、8種類中6種類のマーカーが今回使用可能であり、集団間の遺伝的分化を調べるための遺伝子分化係数FstとNeiの遺伝距離Dを用いて主座標分析と系統樹の描画を行った。その結果、FstとDのいずれの指標を用いても同様の系統樹が得られ、遺伝的分化は流域内で大きく異なることはなかったが、河川の上下流域および支流間でわずかながら異なることがわかった。このことから、今回の調査河川では3つのゾーンに生息域が分割されると推察された。また、環境用水の導入により、他河川から魚類が流入している可能性があることが考えられた。今後は異なる魚種の分子マーカーを用いてDNA解析を行い、魚類生息域の特定手法を確立する予定である。

  • 生物膜電極を用いた新規の嫌気性酸化処理法に関する研究

    2008  

     View Summary

    閉鎖性水域の富栄養化問題は世界的に顕在化、慢性化しつつあり、上水障害や水域生態系の破壊等を招いている。本研究は富栄養化問題の原因物質である排水中のアンモニア成分を少ないエネルギーで脱窒処理する新しい処理法の開発を目的とし、電極上に生物膜を形成させた生物膜電極を用い、嫌気性条件下でアンモニアを窒素ガスに変換する新しい処理プロセスの性能について実験的検討を行った。なお、前年度の研究結果を踏まえ、炭素繊維を負極に用いた処理装置を新たに作製して処理性能の向上を図り、また正極槽は硝化反応の進行を抑えるためにフェロシアン化物を供給した。さらに、装置は微生物の添加系と非添加系の2槽を並行して連続運転し、処理性能の比較検討を行った。 その結果、微生物添加系は非添加系に比べて多くの電流が発生し、微量ではあるが窒素ガスが生成されることがわかった。消費アンモニア量と生成窒素量のモル比は2.9:1、消費アンモニア量と生成電子量の比は1:4.9、ファロシアン化物の酸化量と生成電子量の比は1:0.98程度の値であった。したがって、従来とは異なる創エネルギー型の脱窒処理プロセスの可能性が示唆されたが、生成電流および脱窒量は十分に大きいとは言えず、微生物の集積法等に関する検討が今後必要であると考えられた。装置内の電極面積を向上させた実験では当初予想したような電流値の上昇あるいは脱窒量の向上はみられなかった。また、生成電流および脱窒量は十分に大きいとは言えず、微生物の集積法等に関する検討が今後更に必要である。

  • 高度電気化学的水処理法に関する研究

    2008  

     View Summary

     20世紀後半から、し尿を分離して資源として再利用する持続可能なサニテーションシステムが提唱されている。尿中には抗生物質やエストロゲン等の有害物質が含まれており、再利用の際にはこれらの物資を効率良く除去することが重要になる。本研究では尿中の主成分である尿素等はそのまま通過させ抗生物質やエストロゲン等を除去する新しい処理プロセスを開発することを目的として、これまで研究している3次元電解槽の処理性能に関して理論的並びに実験的検討を行った。なお、有害物質として、生物撹乱性の最も大きい女性ホルモン(E2)及び公共水域で検出頻度が最も高い抗生物質の一つであるテトラサイクリン(TC)を用いた。 その結果、人工尿を電解酸化すると、尿酸、E2、TCの順に除去され、主成分の尿素は未処理のままであることがわかった。また、尿酸を予め除去すればE2, TCの除去速度は飛躍的に向上すること、グラッシー粒状電極あるいはPt/Ti粒状電極を用いた場合にほぼ同様の処理性能が得られること、安定して連続処理可能であること等がわかった。さらに、最近国内外で研究されているオゾン処理法、光触媒酸化法、促進酸化処理法等に比べて処理に要するエネルギーが極めて少ないことも示された。一方、処理性能を表す数学モデルを限界電流理論に基づき構築し、モデル計算値と実測値を比較したところ両者は大きく異なった。モデル内に電解酸化の効率を表す係数を導入すると実測値のシミュレーションは可能であるが、係数は操作条件により異なり、その数値については今後更に検討が必要であると考えられた。

  • 新規の嫌気性酸化処理法によるC・N同時除去

    2007  

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     好気性微生物を用いた生物処理法は都市下水等の排水処理に広く用いられているが、酸素を絶えず供給するためエネルギー消費量が大きく、また微生物増殖に伴って大量に発生する余剰汚泥の処理処分の問題が深刻化している。このような問題を解決するために、本研究では従来とは異なる新しい生物処理法の可能性について基礎的検討を行った。すなわち、生物代謝反応の電子受容体である酸素の代わりに、処理槽内に浸漬した電極により浄化過程で生ずる電子を回収することによって、酸素供給が不要で栄養塩類が除去でき、さらにエネルギー回収も可能な浄化法の可能性について検討した。 実験は負極槽および正極槽を陽イオン交換膜で仕切り、負極槽に有機物((C)及びアンモニア(N)を半回分方式で供給しながら、処理水質、窒素発生量、電流等を測定した。なお、実験装置は負極槽内に微生物を接種した処理系と微生物が存在しない無生物系の2系列を用いた。その結果、負極槽内に微生物を接種することにより、電流が検出され、電子回収が可能であることが確認された。また、アンモニア性窒素の消費及び窒素ガスの発生が確認された。一方、正極槽では溶存酸素(DO)が消費され、その消費速度は電子回収量(電流値)と概ね一致した。しかしながら、現段階では浄化速度が小さく、浄化過程の量論関係を解析するには至らなかった。今後は微生物の集積を進めると共に、電極面積を増加させた実験系を用いて検討を行う予定である。

  • 下排水中に存在する極微量有害物質の高速・高効率電解処理

    2007  

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    下排水中には種々の有機物や無機物が存在するが、更に極微量の医薬品や内分泌攪乱物質等が含まれている。本研究では粒状電極を充填した3次元電解槽を作製し、水環境中に高頻度で検出されている抗生物質(テトラサイクリン)、環境ホルモン(EDCs)及び女性ホルモン(E2)の処理能力について実験的検討を行った。 その結果、これらの微量物質はPt電極および炭素電極(グラッシーカーボン(GC))を充填した電解槽により効率良く除去されることが分かった。ここで、排水中に多量に存在するフミン質に処理性能は影響されないが、尿酸が存在すると(低い酸化電位により)尿酸が最初に酸化除去され、その後、E2, TC, EDCs等が除去されることがわかった。また、処理速度はEDC等の液境膜移動速度に支配され、定常状態の処理水質を表す数学モデルを構築した。 また、数学モデルに基づいて、電解槽をn分割すると処理性能は飛躍的に向上し、例えば処理槽の全容積を一定として、電解槽を2つあるいは3つに分割すると、処理水質はそれぞれ1/10、1/100に低下すると考えられた。特に女性ホルモン(E2)は数ng/lの極低濃度で魚類等に撹乱作用を与えることが報告されており、電解処理はこのような濃度域まで効率良く処理できることが示された。なお、EDC及びE2の電解処理では電極表面にポリマー状の酸化皮膜が形成され、定期的な電極再生が必要である。本研究でFenton法による電極再生について検討したところ、本法により酸化皮膜が数分間で完全に分解されることがわかった。処理に要する消費電力は数~数10Wh/m3程度であり、既往の酸化処理法に比べて数桁以上小さいことがわかった。 以上より、電解処理は優れた処理性能を有するが、最適な電解操作条件、設計条件等については更に検討が必要である。

  • バイオ発電用生物膜電極を用いた創エネルギー型廃水処理技術の研究開発

    2005  

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    活性汚泥法は下排水処理の主要プロセスとして広く普及しているが、ばっ気操作や汚泥処理に多大のエネルギーを必要とする。本研究は排水中の有機物が有する潜在エネルギーを電極を介して回収すると共に、排水を嫌気性条件下で酸化処理する新しい水処理法の可能性について検討した。 実験は先ず反応に深く関与すると考えられる鉄還元菌を連続流通下で集積培養し、Fe(Ⅲ)-EDTAを用いて、有機物分解量と鉄還元量の関係について検討した。次に、負極槽に粒状活性炭を充填した実験装置を作製し、活性汚泥および消化汚泥を接種した。続いて、基質となる有機物として酢酸ナトリウム1000 mg/&#8467;をHRT=1日で連続供給し、全有機炭素(TOC)減少量、電圧、電流等を測定した。 その結果、鉄還元菌は有機物(酢酸)をほぼ式(1)に従って分解することがわかった。第2鉄イオンの還元に関わる電子を式(2)、(3)で回収できれば、バイオ発電によるエネルギー回収と廃水処理を同時に達成できると考えられる。 CH3COOH + 8Fe3+ + 3H2O = 8Fe2+ + H2CO3 + CO2 + 8H+ (1) 負極:CH3COOH + 2H2O = 2CO2 + 8H+ + 8e- (2) 正極:O2 + 4H+ + 4e- = 2H2O (3)また、連続条件下の電子回収量(電流値)とTOC分解量との関係について検討した結果、処理槽から電圧、電流が発生し、収率は式(2)に対して10%程度であった。一方、発電とは逆に微弱電圧を印加して電流値を上げると、TOC分解量が向上する傾向がみられた。これらの結果から、創エネルギー型廃水処理は可能であるが、今後は処理速度および収率を上げるための装置工学的な検討が必要である。

  • 地下水透過型浄化壁の開発と水循環系への適用

    2004  

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     化学(窒素)肥料の散布や畜産廃棄物の土壌還元等により、地下水硝酸汚染が先進国を中心に顕在化している.このような地下水汚染の対策技術として、筆者らは風力発電等により得た電解水素を地下水帯水層内に注入し、硝酸イオンを無害な窒素ガスに脱窒処理する方法を提案している. 本研究では実験室規模の帯水層を作製し、その内部に異なる粒子(0.1~10mmの砂、砂利等)を充填した透過壁を構築した.次に、硝酸イオン含有地下水を連続供給し、水素ガスを注入しながら脱窒処理実験を行った.その結果、全ての透過壁で脱窒処理が可能であるが、その性能は粒子径に大きく依存することがわかった.これは透過壁下部に注入された水素ガスが透過壁内部では逆ツリー状に流路を形成しながら上昇するが、この際の総括的な溶解速度が粒子径に影響されるためである.異なる粒子径の透過壁に対する総括移動容量係数を測定し、また、既往研究に従って、透過壁の浄化性能を表す数理モデルを構築した.また、モデルより得られる計算値と実測値を比較した.その結果、粒子径がある程度大きな透過壁では数理モデルと実測値は概ね一致したが、粒子径が小さいと、微生物膜の剥離・目詰まりによる編流が生じ、その結果、実測値は計算値よりかなり小さくなった.今後は、数理モデルを改良すると共に、目詰まりが生じにくい透過壁構造について検討する予定である.

  • BER/吸着プロセスの高度水処理性能とその速度

    2001  

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     農薬および硝酸塩による水源(地下水及び地表水)の汚染が先進国を中心に顕在化している。本研究はこのような汚染水を浄化する新しい水処理法として、生物膜電極槽(BER)に吸着プロセスを組み込んだハイブリッド生物膜反応槽の水処理性能について検討した。なお、殺菌剤のイソプロチオラン(IPT)をモデル農薬として用いた。 これまでの研究では、1)被処理水中に硝酸塩のみが存在する場合、BER内の水素利用性微生物の作用により、有害な硝酸塩を窒素ガスに効率良く還元・無害化(脱窒)できるが、2)農薬のIPTが高濃度で存在すると、脱窒過程の最終段階が阻害され、有害でかつ地球温暖化物質でもある亜酸化窒素が蓄積することを明らかにしている。 このような問題を解決するために、陽極に粒状活性炭(GAC)を充填したハイブリッド生物膜反応槽を提案し、その処理性能を表わす数理モデルの構築を試みた。モデル計算値は実測値と比較してその妥当性を検証すると共に、BERとGAC吸着槽を直列に組合わせた水処理プロセスの性能と比較した。その結果、硝酸塩除去に関してはハイブリッド生物膜反応槽と組合わせプロセスはほぼ同様な性能を示すが、処理槽内の亜酸化窒素濃度はハイブリッド生物膜槽が組合わせプロセスの約1/100以下になることが示された。すなわち、本研究で提案したハイブリッド生物膜槽は硝酸塩酸塩と農薬の同時処理法として優れた性能を有することがわかった。今後は他の農薬も含め、GACの再生法及び農薬の直接分解法について研究する予定である。 なお、本研究結果の一部は、2001年IWA国際水会議(ベルリン会議)で発表した。

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Overseas Activities

  • バイオバリアー法に関する研究

    2007.03
    -
    2007.09

    アメリカ   ピッツバーグ大学

 

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