SEPARATE SIDESTREAM TREATMENT PROVIDES MULTIPLE BENEFITS AT THE SOUTHSIDE WWTP

Dallas Water Utilities (DWU) currently owns and operates two wastewater treatment plants (WWTP) that service the Dallas area: the Southside WWTP and the Central WWTP. The biosolids processing system at the Southside WWTP is currently being upgraded to process all residuals produced at the Southside and Central WWTPs. The plant uses belt filter presses (BFP) for dewatering prior to disposal. The sidestream from the BFP has high concentrations of ammonia. Since the plant will soon process residuals from two WWTPs, the ammonia-nitrogen loading in the sidestream will increase significantly compared to the current loading.A study was conducted to identify the available alternatives for the treatment of the ammoniarich, dewatering sidestream. This paper presents the process theory behind each alternative, and also discusses the results of a full-scale pilot study to determine the effectiveness of a conventional nitrifying activated sludge treatment process in treating sidestream, which is currently being conducted at the Southside WWTP. The data from the pilot study indicates that better that 95 percent nitrification could be achieved by the process.