著者

後藤 光亀 平田 強 牛尼 修央 佐藤 敦久

出版者

公益社団法人 土木学会

雑誌

環境工学研究論文集 (ISSN:13415115)

巻号頁・発行日

no.31, pp.181-188, 1994

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The cross flow type ultrafiltration was carried out to evaluate the relation between flux and coagulation state using the results of zeta potential, flux reduction ratio, volumetric sedimentation ratio, the turbidity reduction ratio in Jar test. The concentration of kaolin suspension used in this study was 1000 mg/l. The ion concentration of the raw water was controlled by changing mixing ratio of distilled water and tap water, or with adding NaCl and CaCl<SUB>2</SUB> solution. As the dispersion state of kaolin suspension was good, the flux of ultrafiltration hardly decreased because of the large negative charge of suspended solid and shearing force under cross flow. If the dispersion state of kaolin suspension was not good, the flux of ultrafiltration was getting small by destabilization of dispersion state. This small change of coagulation state gives large influence on the flux. On the other hand, the cation or coagulant dosage makes coagulated flocs and the resulted large floc and shearing force under cross flow obstructs the cake formation on membrane.

著者

橋本 温 河井 健作 西崎 綾 松本 かおり 平田 強

出版者

公益社団法人 日本水環境学会

雑誌

水環境学会誌 = Journal of Japan Society on Water Environment (ISSN:09168958)

巻号頁・発行日

vol.22, no.4, pp.282-287, 1999-04

被引用文献数

5

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In order to investigate the occurrence and indicator of protozoa in water, water samples were collected from 11 points along the Sagami River and its tributaries for 9 months. The concentrations of Cryptosporidiurn oocysts, Giardia cysts and potential indicators (presumptive Clostridium perfringens spores, Escherichia coli, coliforms, aerobic spores and turbidity) were analyzed. Cryptosporidium oocysts were detected at 10 of the 11 sampling points (GM 34 presumptive oocysts·100l-1, 24 confirmed oocysts·100l-1) and Giardia cysts were detected at all sampling points (GM 30 presumptive cysts·100l-1, 12 confirmed cysts·100l-1). Based on a regression analysis, the concentrations of presumptive C.perfringens spores and E.coli were significantly correlated with the concentrations of protozoa. In a multiple regression analysis, the concentration of presumptive C.perfringens spores, E.coli and aerobic spores were selected as explanatory variables for the protozoan concentrations. The results indicated that presumptive C.perfringens spores, aerobic spores and E.coli were useful indicators for protozoan contamination.