Combining NF/RO with Ion Exchange Using RO Concentrate and Alternative Regeneration Brine Sources to Treat Multiple Fresh and Brackish Groundwater Supplies at the Lee County Utilities Green Meadows WTP

A pilot-scale treatability study was conducted for Lee County FL to examine how to minimize the level of pretreatment and manage NF/RO membrane fouling while allowing for maximum flexibility in the utilization of multiple and variable water resources. Testing identified a two-step ion exchange process (strong sodium-based cation followed by weak chloride-based anion) for the appropriate treatment of the freshwater surficial source to remove iron, hardness, and color prior to blending with RO permeate from treatment of the other freshwater and brackish water sources.