AWWA ACE60060

Low-pressure membrane filtration systems are becoming increasingly popular as utilities begin upgrading their existing conventional water treatment systems. This paper presents the key issues and challenges involved in designing a membrane system's ancillary equipment. The design of a 50-million-gallons-a-day (mgd) (expandable to 60- mgd) submerged membrane system and related ancillary equipment at the Racine Water Utility (Racine, Wisconsin) is used as a case study. Although the focus of membrane system design is often concentrated on membrane-related parameters, such as type of membrane, number of fibers, configuration of module, flux rate, and performance, the real challenge to successful membrane system implementation is the design of integrated ancillary equipment needed to operate the system. In order for the membrane system to achieve its performance goals, the support equipment has to be properly designed. Membrane system ancillary equipment is responsible for the operation of the system. The day-to-day operation of a low-pressure membrane system involves multiple processes, including permeation/filtration, backwash, various cleaning routines, and integrity testing. Ancillary equipment required for the successful operation of the membrane system include such components as dedicated pumps, blowers, compressors, chemical systems and control systems. Membrane suppliers typically work with the engineer and the owner on the design of such components to integrate membrane system requirements with plant, site, and operational requirements. Includes tables, figures.