16-02: Increasingly Complex Tower Makeup Water Issues

As fresh water becomes increasingly scarce in the United States, or perhaps due to political pressures, new power and industrial plant owners are turning to alternatives supplies for plant makeup, including the makeup to cooling towers. A common source is secondary treated municipal wastewater effluent.

These waters often contain impurities that serve as nutrients for microbiological fouling in cooling systems, and include ammonia, phosphorus, organics, and suspended solids. It may not only be beneficial but imperative to remove these containments upstream of the cooling tower, but methods to do so require careful planning and selection.

Technologies that are coming to the forefront from 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.