污水再生处理系统中隐孢子虫和贾第鞭毛虫检测方法的优化

隐孢子虫和贾第鞭毛虫是2种严重危害水质安全的病原性原生动物.与USEPA1623方法相比,以膜过滤-洗脱法作为浓缩方式的检测流程回收率较高且成本较低.本研究通过对膜过滤-洗脱环节和免疫磁性分离(IMS)过程进行改进和参数优化,建立了适用于污水再生处理系统的两虫检测方法.研究发现,对滤膜进行刮擦处理后隔夜浸泡,以及洗脱前剧烈振荡等操作能够显著提高并稳定回收率.投加高岭土浊液提高水样的浊度至4NTU更加有效地提高了低浊水样的浓缩回收率.离心浓缩后洗涤沉淀并进行2次酸解离是降低IMS过程水质干扰的有效措施.采用该优化方法对不同来源水样进行检测,隐孢子虫回收率超过70%,贾第鞭毛虫回收率超过80%,明显高于1623方法的接受标准(>24%).

Improvement of Method for Detection of Cryptosporidium and Giardia in Wastewater Reuse System

Cryptosporidium and Giardia are two common species of pathogenic protozoan,seriously endangering the water quality.Former work indicated that compared to the USEPA method 1623,the procedure using membrane filtration-elution as a concentration method for detection of Cryptosporidium and Giardia attained better recovery and lower cost.Several improvements of membrane filtration-elution step as well as immunomagnetic separation(IMS) step were investigated and an optimal method for detection of Cryptosporidium and Giardia in wastewater reuse system was recommended in this study.The experimental results showed that overnight soak of membrane after scraping and vortex agitation before elution could enhance and stabilize the recovery.Increasing turbidity to 4NTU by adding kaolin clay could effectively improve the recovery of low-turbidity water.Washing concentrate after centrifugation and twice acid dissociation both reduced the impact of water quality.Protozoan in different water samples were detected by this optimal method,and recovery of Cryptosporidium and Giardia are above 70% and 80% respectively,far beyond the acceptance of method 1623.