过滤饮用水的质量标准变得越来越严格，部分原因是人们越来越担心抗消毒剂病原体（如隐孢子虫）可能通过过滤器。这引起了人们对操作实践许多方面的关注，包括处理厂内废过滤器反洗水的回收。在美国，1996年《安全饮用水法》修正案要求美国环境保护局（USEPA）制定一项法规，管理反洗水回收的实践。 在制定2000年4月提出的过滤器反洗循环规则草案（美国环保局，2000年）时，发现对反洗循环对处理的实际影响进行的系统研究相对较少，尽管50%至60%的美国处理厂采用了这种做法。BHC公司和麻省大学通过AWWARF定制的合作项目，研究了全面的回收实践，并对通过澄清和过滤去除病原体以及过滤器反洗回收的影响进行了广泛的中试研究。 本文旨在展示反洗循环加载速率和质量变化对后续澄清和过滤性能影响的中试研究结果。这部分工作的重点是颗粒去除措施，如浊度、颗粒计数和悬浮固体，以及有机物去除和混凝条件。包括7个参考文献、表格、图表。

Standards for the quality of filtered drinking water have become increasingly more stringent, in part because of increased concerns about the possible passage of disinfectant resistant pathogens, such as Cryptosporidium, through filters. This has caused increased attention to many aspects of operational practices, including the recycle of spent filter backwash within the treatment plant. In the USA, the 1996 Safe Drinking Water Act Amendments required the US Environmental Protection Agency (USEPA) to create a regulation governing the practice of backwash recycle. In developing the draft Filter Backwash Recycle Rule, proposed in April 2000 (US EPA, 2000), it was found that there were relatively few systematic studies of the actual impact of backwash recycle on treatment, despite use of this practice by 50 to 60% of US treatment plants. BHC Company and UMass, through an AWWARF Tailored Collaboration Project, have studied full-scale recycling practices and conducted extensive pilot-scale studies of pathogen removal by clarification and filtration and the impacts of filter backwash recycle. The purpose of this paper is to present results of pilot-scale investigations of the impacts of variations in backwash recycle loading rate and quality on subsequent clarification and filtration performance. This portion of the work is focused on measures of particle removal such as turbidity, particle counts and suspended solids, as well as on organic matter removal and coagulation conditions. Includes 7 references, table, figures.