Temporal variation of NOM and its effects on membrane treatment

The concentration and composition of natural organic matter (NOM) in the Mississippi River vary with precipitation and seasonal changes; these variations can affect a utility's ability to consistently produce quality finished water. In this study, near real-time monitoring was conducted to provide a better understanding of temporal organic matter dynamics and correlate NOM concentration and composition to the performance of a full-scale membrane ultrafiltration plant. Membrane permeability -an indicator of fouling - was negatively correlated with river flow and raw water specific ultraviolet absorbance but not raw water dissolved organic carbon. The use of near real-time monitoring equipment to observe variability in NOM concentration and composition could prove a useful tool to proactively manage water treatment in order to produce high-quality finished water with minimal chemicals and membrane fouling. The potential benefits derived from the increased data in terms of optimizing chemical dosing rates and membrane backwash and cleaning schedules should outweigh the maintenance requirements of such instrumentation.