Extending membrane longevity by using MIEX as a pre-treatment

Abstract

The use of membrane technology and in particular microfiltration (MF) is becoming more popular as a water treatment technology. The operational lifetime of MF membranes can be reduced by natural organic matter (NOM) which is a known foulant. The MIEX DOC (Magnetic Ion EXchange for Dissolved Organic Carbon removal) process was developed to remove NOM from raw water sources. It was anticipated that a reduction in NOM resulting from the MIEX DOC process would also improve the performance of MF systems. A pilot plant study was undertaken to directly measure the impact of MIEX pre-treatment on MF performance. A long term study with a regular cleaning strategy revealed little benefit in MIEX pre-treatment to improve the lifetime of the MF membrane. However, by applying less frequent cleaning it was immediately apparent that fouling was occurring at a faster rate without MIEX pre-treatment. Further studies showed that irreversible fouling also occurred at a faster rate on the membrane without pre-treatment.