Biological WWTP for Coke Battery Wastewater Discharge: Design, Construction and Start-Up Challenges and Solutions

摘要

DTE Energy, Inc./EES Coke Battery, LLC (DTE/EES) operates the No. 5 Coke Battery and the No. 3 By-Product Recovery Plant located on Zug Island in Detroit, Michigan (Site). Site operations generate process wastewater at a rate of approximately 200 gpm. This wastewater is processed through the byproducts recovery plant on-site to remove primarily tar, phenols, and free/fixed ammonia. These byproducts that are removed from the wastewater stream are recovered in various forms for additional processing, reuse, sale, and/or disposal. The effluent wastewater stream passing through this process was discharged to the Detroit Water and Sewerage Department (DWSD) public owned treatment works (POTW) via the municipal sanitary sewer system with no further treatment. In March 2005, the DWSD presented new discharge limitations in the City of Detroit Ordinance 08-05 (National Categorical Pretreatment Standards are incorporated by reference into this ordinance) which applied to many industrial users of the sewer system in the Detroit metropolitan area. Most notably for DTE/EES, this ordinance reduced the discharge limit for mercury to <0.2 ug/L and the limit for phenolic compounds to 0.5 mg/L. This paper discusses the design, construction and start-up of a biological treatment system to achieve these new discharge limits that was installed and integrated into an active coke battery without significant interruption to production activities.