微滤（MF）和超滤（UF）膜系统在城市饮用水处理中的应用越来越普遍。通常，这些工厂的产能低于1000万加仑/天（mgd）。然而，一些大容量超滤装置正在设计或建造中，使用浸入式膜。例如，加利福尼亚州圣地亚哥附近的Olivenhain市政饮用水处理设施计划于2001年9月完工，其初始和最终额定容量分别为25 mgd和30 mgd。本文介绍了使用超滤膜改造现有快速重力砂滤器和沉淀池的基本设计概念。 特别强调大型处理设施的改造。其中包括对现有过滤池进行改造的示例。关于新处理设施的布局，提供了更多信息。包括2个参考文献、图表。

Application of microfiltration (MF) and ultrafiltration (UF) membrane systemsfor municipal potable water treatment is becoming increasingly common. Typically, the capacity of these plants is less than 10 million gallons per day (mgd). However, several largecapacity UF plants are in design or under construction utilizing immersed membranes. For example, the Olivenhain Municipal Drinking Water Treatment Facility near San Diego, California, scheduled for completion in September 2001, will have an initial and ultimate rated capacity of 25 mgd and 30 mgd, respectively. This paper introduces basic design concepts used to retrofit existing rapid gravity sandfilters and sedimentation basins using UF immersed membranes. Particular emphasis is given to conversion of large treatment facilities. An example of the retrofit of an existing filtration basin is included. Additional information is presented for the layout of new treatment facilities. Includes 2 references, figures.