ABSTRACT
Both ultrafiltration and microfiltration are demonstrating great promise in providing compliance with some of the more difficult requirements of the Surface Water Treatment Rule. However since the electrodialysis reversal (EDR) technology is not capable of removing significant amounts of organic carbon, additional water treatment may be required in some applications to satisfy regulatory water quality standards. Like reverse osmosis RO, EDR is a modular system, and the basic design is adjusted to provide the hydraulic and rejection characteristics required for a specific application. The application of softening membrane or nanofiltration technology to potable water systems is very similar to the more well known RO. One of the major advantages of using membranes in lieu of more conventional water treatment technology is that a membrane system will produce a product water of virtually consistent quality, easily accommodating some variation in feedwater quality. Higher recovery is desirable with open intake seawater treatment because of the additional cost of pretreatment.
