Addition of supplemental bacteria to aerobic digester suppresses harmful organic acid in waste stream
Download PDFMeet NH3 (ammonia) effluent limits set by the NPDES permit program
Gulf Coast
The wastewater treatment plant (WWTP) at a refinery faced challenges in meeting NH3 (ammonia) effluent limits set by the National Pollutant Discharge Elimination System (NPDES) permit program for river discharge. As the refinery processed more “opportunity” crude with elevated NH3 content, a solution to reduce the ammonia concentration became vital.
The operator sought a bioaugmentation solution to allow for the continued processing of high-NH3 and high-organic-acid crude types at the refinery, which may increase the chemical oxygen demand (COD) and hinder the nitrifier population in the biological system.
Halliburton recommended the addition of supplemental bacteria to the plant’s biological treatment section to suppress the effects of harmful organic acids in the waste stream. This solution reduces the concentration of inhibitory compounds in the biological system and augments the current nitrifier population to spur additional growth and reduce NH3. Additionally, the cost of a single application is potentially less than the fine associated with a single NH3 exceedance.
Annual savings
The supplemental bacteria solution was implemented within 30 days without disrupting operations and provided the operator with an estimated annual value of ~USD 280K. It allowed the refinery to continue processing high-NH3 crude and some of the high-organic-acid crude types, which had previously hindered the nitrifier population in the biological system, thereby maximizing flexibility and profitability.
