Source water pollution with Cryptosporidium oocysts and removal and inactivation in water purification system

隐孢子虫卵囊对水源水的污染及净水系统的去除和灭活

• 批准号: 09650606
• 负责人: HIRATA Tsuyoshi
• 金额: $ 2.24万
• 依托单位: College of Environmental Health, Azabu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650606/
• 关键词: Cryptosporidium; Giardia; Protozoan pollution; ozonation; electric disinfection; inactivation; 嫌気性芽胞; 好気性芽胞; 大腸菌; ウェルシュ菌芽胞; 水環境汚染; 浄水処理; 感染リスク

One-year field survey on Cryposporidium pollution in river water was carried out at 11 stations in Sagami river. The level of Cryptosporidium in the river ranged 1-11,000 oocysts/100L with geometric mean of 24 oocysts/1OOL and the level of Giardia was in the range of 1-20,000 cysts/lOOL with geometric mean of 12 cysts/1OOL.The levels of oocysts and cysts were significantly correlated with the levels of heat-tolerant Clostridium perfringens spores. Thus, the heat-tolerant Clostridium perfringens spores were recommended as primary indicator for protozoan pollution of waters.Experimental study of the assessment of ozonation and electric disinfection system composed of eight layers of carbon graphite disks for inactivating Cryptosporidium parvum oocysts was conducted. Ozonation could reduce the infectivity of the oocysts by 2 logs at CT product of 3 - 6 mg・min/L.Electric disinfection system removed the oocysts by 2-3 logs by passing once through the system. The oocysts trapped on the carbon graphite disc were killed by 40% within 24 hours and by greater than 8O% within 72 hours.

对相模川11个采样点的河水中隐孢子虫污染状况进行了为期1年的现场调查。隐孢子虫的含量范围为1 ~ 11，000个卵囊/100 L，几何平均数为24个卵囊/100 L;贾第虫的含量范围为1 ~ 20，000个囊/100 L，几何平均数为12个囊/100 L;卵囊和囊的含量与产气荚膜梭菌孢子的耐热性显著相关。为此，建议将产气荚膜梭菌的耐热芽孢作为沃茨原生动物污染的主要指示菌。臭氧消毒在CT值为3 ~ 6 mg·min/L时可使卵囊的感染力降低2个对数级，电消毒系统一次通过可使卵囊的感染力降低2-3个对数级。捕获在碳石墨盘上的卵囊在24小时内被杀死40%，在72小时内被杀死80%以上。

项目成果

Hirata T and Hishimoto A.: "Experimental assessment of the efficacy of microfiltration and ultrafiltration for Cryptosporidium removal." Water Science and Technology. 38(12). 103-107 (1998)

Hirata T 和 Hishimoto A.：“微滤和超滤去除隐孢子虫功效的实验评估。”

Hashimoto A,Kawai K,Nishizaki A,Matsumoto K and Hirata T.: "Occurrence of Cryptosporidium and Giardia in Sagami River and their indicators." Journal of Japan Society on Water Environment. 22(4)(in press). (1999)

Hashimoto A、Kawai K、Nishizaki A、Matsumoto K 和 Hirata T.：“相模河中隐孢子虫和贾第鞭毛虫的发生及其指标”。

橋本温,平田強: "相模側水系におけるクリプトスポリジウムおよびジアルジアの汚染レベル" 水環境学会誌. 21-2. 119-122 (1998)

Atsushi Hashimoto、Tsuyoshi Hirata：“相模侧水系统中隐孢子虫和贾第鞭毛虫的污染程度”，日本水环境学会杂志 21-2（1998 年）。