AWWA MTC57587

At the heart of every membrane system is its membrane elements. The life of a system's membrane elements will have a substantial impact on the financial feasibility for constructing, operating, and maintaining a membrane facility. Although the life span of membrane elements is difficult to predict, it is possible to prepare membrane facility operators and maintenance personnel for eventual scaling and/or fouling of the membranes, and the associated reactions to operational changes that are appropriate. It is very important to know when and how to clean. If cleanings are performed at the correct time, and with the appropriate methods performance can be restored and membrane life can be extended. This paper discusses proper monitoring techniques that can lead to proper assessment of cleaning intervals, as well as various cleaning scenarios for various types of fouling and scaling. Since there is limited collective knowledge of cleaning regimes at various membrane facilities, this paper also includes survey results from membrane facilities in the State of Florida regarding pretreatment practices, cleaning frequencies, cleaning practices, cleaning waste disposal methods, and average life of membrane elements. This paper also discusses the role of cleaning relative to membrane warranty issues. Includes figures.