MEMBRANE RESIDUALS WILL IMPACT WASTEWATER TREATMENT FACILITIES AND EFFLUENT QUALITY

Given the benefits derived from membrane treatment of water and wastewater there is an increasing interest in using membranes across this country. The focus has been on the benefits on product water (permeate) side of the system. With any new technology or application, there are benefits and liabilities. Membrane separation is a non-destructive technology. Membranes merely concentrate the rejected pollutants in a sidestream. There are several types of membrane systems used in water and wastewater treatment. The sidestream from each type of membrane contains pollutants at different concentrations.What impacts do these unwanted pollutants have on the WWTP, and the collection system? This paper reviews issues related to corrosion, recycle/concentration of pollutants in the wastewater, process inhibition, WWTP effluent quality, and impacts on the receiving streams. There are also water balance impacts that can significantly increase the concentration of residuals entering a wastewater system. Often the water utility sells water to outside customers who do not return it as wastewater to the local WWTP. Such water imbalances may cause additional stress on the wastewater treatment plant and its receiving stream. This paper presents a summary of an ongoing WateReuse Foundation (WRF) study on the impacts of membranes residuals on WWTPs.