中水回用于城市景观用水大肠菌群密度分布与风险分析

Risk Analysis and Density Distribution of Coliform on Reclaimed-Water Reused as Urban Scenic Water

对污水处理厂排放的中水和经过异噻唑啉酮杀菌后的中水进行了大肠菌群检验,结果表明,杀菌前后中水的大肠菌群浓度服从对数正态分布.参考我国中水回用于景观用水水质标准,对水中病原微生物进行风险分析,结果显示,未经杀菌处理的中水回用于各类景观用水,其安全保障率均为0,风险度为100%,经3mL/L浓度的异噻唑啉酮杀菌处理8h后的中水,回用于观赏性景观用水(河道湖泊类)时,安全保证率为89.07%,风险值较小,但回用于观赏性景观用水(水景类)、娱乐性景观用水(河道湖泊类和水景类)时风险值较大,安全保证率低.

Lots of experiments are conducted to detect coliforms in recycled water before and after sterilizing. The distribution is tested by figure Q-Q. Results show that,quantitative description of coliforms before and after sterilizing can be realized by lognormal distribution. According to water quality standards constituted in our country, security rate before and after sterilizing is computed and health risks in various uses is analyzed. As the result,iCs necessary to sterilize recycled water that is reused in landscape. By trea- ting with 3 mL/L isothiazolone for 8 h, the probability of coliform in reclamation water meeting with the reuse standards is 89.07% for ornamental landscape water （rivers and lakes）,which present less risk to human health and ecological environment. Security is low when recycled water is reused in ornamental landscape of waterscape and ,entertainment landscape water after sterilizing.