Effect of pretreatment on surface water nanofiltration

Abstract

A pilot study using integrated membrane systems suggests that MF or UF pretreatment may be necessary to reduce fouling during NF of surface water.An integrated membrane system pilot study compared microfiltration (MF), ultrafiltration (UF), and conventional treatment as pretreatment strategies for surface water nanofiltration (NF) using spiral‐wound elements. MF and UF pretreatment resulted in lower NF fouling rates and longer cleaning intervals compared with those measured following conventional treatment. NF fouling rates evaluated under a wide range of hydrodynamic conditions following conventional treatment suggest NF fouling is more influenced by permeate flux than by feedwater recovery. NF was shown to be capable of meeting all current and anticipated trihalomethane and haloacetic acid regulations.