INCREASINGLY COMPLEX COOLING TOWER MAKEUP WATER ISSUES

摘要

As fresh water becomes increasingly scarce in the United States, and also as a result of political and environmental group pressures, new power and industrial plant owners are turning to alternative sources for plant makeup, including the makeup to cooling towers. A common source is secondary treated municipal wastewater effluent. These waters usually contain impurities that serve as nutrients for microbiological fouling in cooling systems, and include ammonia, phosphorus, organics, and suspended solids. It is often imperative to remove these contaminants upstream of the cooling tower, but methods to do so require careful planning and selection. Technologies that are coming to the forefront include membrane bioreactors (MBR) and moving bed bioreactors (MBBR). They may be integrated with clarification and other treatment methods to achieve the desired cooling tower makeup quality. This paper examines these emerging issues.