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1996 Fiscal Year Final Research Report Summary

Study on phosphate and Ammonium Removal using Magnesium Ammonium Phosphate Crystallization

Research Project

Project/Area Number 07650929
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 反応・分離工学
Research InstitutionWaseda University

Principal Investigator

HIRASAWA Izumi  Waseda Univ., School of Sci.Eng.Prof., 理工学部, 教授 (10228778)

Project Period (FY) 1995 – 1996
KeywordsEnvironmental Crystall / Wastewater Treatment / Magnesium Ammonium Phosphate / Ind.Cry. / Design / プロセス開発
Research Abstract

Development of Ammonium and Phosphate ions removal process has been needed for removing them from wastewater exhausted in the process of sludge treatment, considering the concept of sludge treatment base in the metropolitan urban cite. In this research, basic investigation was done on the relation between crystallization characteristics and removability. Batch experiments were done to verify the crystallization characteristics of MAP (characteristics of water quality and operational conditions to crystallize MAP selectively), and selective crystallization conditions (temperature, pH,Mg/P molar ratio and NH4/P molar ratio) was obtained. Based on the results above, batch reactive crystallization experiments were performed, to investigate relation between the process of Magnesium and Phosphate removal and crystallization of MAP,and to clarify operational pH and Mg/P molar ratio for obtaining optimum removal efficiency and consider MAP crystallization based on nucleation and crystal growth phenomena, by measuring the dynamic change of crystal size and its shape through SEM.And also Alcohol addition method was investigated, to make clear the effect of alcohol on the solid-liquid equilibrium. Addition of alcohol lowered the solubility product.
Process of MAP crystallization was considered to consist of reaction of ions, diffusion and surface integration stpes, and it was recognized that integration step determined the rate, when desirable product size was needed. Consequently design method on the material balance and crystallization rate was proposed, considering relation between crystallization rate and design method of the crystallizer.

  • Research Products

    (11 results)

All Other

All Publications (11 results)

  • [Publications] 平沢泉: "MAPの晶析現象を利用した排水中のリン除去" 化学工学シンポジウムシリーズ49"21世紀に架ける晶析技術". 49. 172-177 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Izumi Hirosawa: "Recovery of Ions from Wastewater by Crystallization" 早稲田大学・紀要. 3. 1-15 (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Izumi Hirosawa et al: "Development of Anmonium and phosphato Removel process from Wastemater by Cryscallizations of MAP" HCS Symposium Series "Cryscallization and Separation". in print (1997)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 平沢泉: "物質循環のための工業晶析" 化学工学. 55.4. 500-503 (1996)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] I.Hirasawa et al.: "Phosphate Recovery by Reactive Crystallization of Magnesium Amaonium phosplate (MAP) in the Application to Wastenater" Proceedings of Pacifichem 95'. 1. 1213 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 平沢泉,他: "MAP晶析法による排水中のリン除去に関する研究" 化学工学新潟大会要旨集. 162-163 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] 平沢泉: "物質循環のための工業晶折" 化学工学. 59. 500-503 (1995)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Hirasawa I.et al.: "Phosphate Removal from Wastewater by using MAP crystallization" Kagaku Kougaku Symp.Ser.49. 172-177 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Hirasawa I.: "Industrial Crystallization for Material Recycling" Kagaku Kougaku. Vol.55. 500-503 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Hirasawa I.: "Recovery of Ions from WasteWater by Crystallization" Waseda Univ.Kiyou, March. (in print). (1997)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Hirasawa I.: "Development of Ammonium and Phosphate Ions from Waste-by Crystallization of MAP" ACS Symp.Ser.in print. (1997)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1999-03-09  

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