Approval testing of membrane water treatment systems

Abstract

The current test methods for membrane filtration systems used by the testing and regulatory bodies in Europe and the United States are quite different. In some cases they are based on static test methods developed for simpler products, such as pipes. In other cases also dynamic test protocols (re-circulation systems and single-pass flow modes for point-of-use membrane elements) are used. The present, different approval testing methods and regulatory approvals were presented during an international workshop held on 1–2 October 1997 in Brussels, organized by the UK Drinking Water Inspectorate (DWI) in collaboration with Kiwa NV in the Netherlands and NSF International in the United States. During this workshop it was agreed that dynamic testing has to be preferred over static testing as being more representative of the product's normal use. However, the need for further research to investigate this issue (recriculation versus single-pass flow) was identified. This paper describes the current, different test and approval methods and a draft proposal for collaborative research into the effects of the two dynamic test protocols in order to develop a soundly-based harmonized test method.