AWWA WQTC52879

The purpose of this study was to demonstrate integrated membrane treatment (i.e.,ultrafiltration (UF) followed by nanofiltration (NF)) of a highly turbid, high hardness surface water. Pretreatment for UF was optimized to produce a chemical cleaning frequency no less than 30 days. Pretreatment with chemicals such as aluminum and ferric sulfate was evaluated as a method for reducing membrane fouling and lengthening the intervals between chemical cleanings. NF, used here as a softening process, was also capable of removing DBP precursors. Capital costs and total watercosts were developed based on design criteria refined during pilot testing. These costs were compared to costs for other treatment alternatives including lime softening/ozonation/biologically active filtration (BAF), and lime softening/microfiltration (MF) or UF. The information developed from this work is intended to help utility managers and engineers determine which technologies are appropriate for the treatment of challenging surface water supplies. Includes 12 references, tables, figures.