OCEAN BRINE DISPOSAL

As a result of increased interest by USA utilities and water agencies in sea water reverse osmosis (SWRO), the Electric Power Research Institute (EPRI) sponsored a program to evaluate the behavior of concentrated brine discharges from desalination plants to the ocean, SWRO with recovery ratios up to 50% poses a potential problem because the dense brine concentrate sinks to the ocean floor and may threaten the benthic environment. Little work has been done on negatively buoyant effluents, including brine discharges. The EPA CORMIX computer code [1] was extended to B-CORMIX (Brine-CORMIX) to enable the modeling of both submerged and surface brine discharges. The CORMIX/B-CORMIX codes were used to investigate several brine discharge scenarios including pure brine and brine co-discharged with wastewater. In addition, U.S. EPA discharge rules were adopted to classify brine discharge and suggestions were made for mixing zone definitions and dilution criteria based on the tolerance of biota to higher salinities.