Contact Aeration Wastewater Treatment Plant Upgrading Evaluation, Reese Air Force Base, Texas

摘要

A 1940 vintage contact aeration wastewater treatment (Hays Process) plant at Reese AFB TX was upgraded by replacing the original plain asbestos plate media with honeycombed plastic media to increase the contact surface area. The old, partially clogged air diffusers were also replaced with new ones. A literature review regarding the history, advantages and disadvantages, and design criteria of contact aeration process is presented. The performance efficiencies of the Reese AFB contact aeration treatment plant before and after upgrading are presented and compared with the NRC Equation for the contact aeration process. It was found that the performance efficiencies of the Reese AFB treatment plant are better than what the NRC Equation predicted both before and after the upgrading. The treatment efficiencies after upgrading are 95 percent BOD5 removal, 97 percent for SS removal, and about 50 percent for nitrification. This kind of performance is better than the other conventional secondary treatment systems, such as activated sludge and trickling filter systems, under comparable design criteria. The contact aeration system is also easier to operate because there is no need for recirculation or sludge return. (Author)