Reusing Municipal Wastewater as Industrial Plant Supply

A large chemical plant along the Gulf Coast decided to use municipal wastewater from a nearby city to supply a significant portion of the cooling water and boiler make-up water required for a future plant expansion. This decision was influenced by several factors, including periodic droughts, lack of senior water rights to their primary source of fresh water, salinity of site well water, and a desire to broaden options for sustainable fresh water make-up. Based on anticipated variability in the feed water and quality and space considerations, a preliminary system design was developed using ultrafiltration (UF) for suspended solids removal followed by double pass reverse osmosis (RO) for dissolved solids, silica, and organic carbon removal. Overall, the testing demonstrated that the municipal wastewater source is a feasible alternative to the current water source. The primary performance targets are achievable in a long term operation even with variable feed water quality.