然而，自20世纪60年代以来，反渗透（RO）膜已被用于水的再利用；膜在大规模再利用应用中的使用发生了巨大变化。膜设备在水回用应用中的目标是在清洗频率和化学和能源成本之间找到平衡。本手册全面介绍了在水回用项目中应用膜技术的相关问题。此外，本手册用一整章的篇幅介绍案例研究，以展示各种实际应用。

Reverse osmosis (RO) membranes have been used in water reuse since the 1960s, however; the use of membranes in full-scale reuse applications has changed dramatically. The goal for membrane facilities in water reuse applications is finding the balance between cleaning frequency and chemical and energy costs.This manual presents a comprehensive description of the issues related to applying membrane technologies in water reuse projects. In addition, this manual devotes an entire chapter to case studies to showcase a variety of real world applications.