Cost-Effective Aeration System Design for a BNR Upgrade in New York City

The Coney Island wastewater treatment plant is mandated to carry out a Level 1 biological nutrient removal upgrade by the year 2020. A Level 1 upgrade is intended to be a cost-effective means of reducing effluent total nitrogen with limited capital expenditures. Upgrading a conventional activated sludge plant for nitrogen removal typically requires a net increase in air demand and energy. Accordingly, an aeration system optimization strategy was implemented to limit the future energy increase and ensure cost-effective nutrient removal. The strategy consisted of benchmarking existing equipment used at other New York City nitrogen removal facilities, evaluating the existing equipment at the Coney Island facility, and using a modeling tool to determine the expected aeration requirements and establish a preliminary diffuser design. The focus for optimization was on selecting cost-effective improvements with short payback periods that have proven to be effective at other New York City nitrogen removal facilities.