Full-Scale Operating Experience with a Biological Nitrogen Removal System

DSM Chemicals North America, Inc., (DSM) of Augusta, Georgia manufactures caprolactam, a nylon-6 intermediate chemical. Like many other facilities in the organic chemicals, plastics, and synthetic fibres (OCPSF) industry in the early 1990s, DSM needed to upgrade its onsite direct-discharge wastewater treatment plant to comply with more stringent permit requirements for biological oxygen demand, total suspended solids, and priority pollutants. In addition to these OCPSF regulated parameters, the State of Georgia required DSM to reduce the discharge of total nitrogen by approximately 50 percent.In 1988 DSM began pilot testing to develop a treatment process capabale of meeting the new permit requirements. Pilot testing involved determining raw wastewater characteristics and kinetic and stoichiometric coefficients. These values were used as input to Simulation of Single Sludge Processes (SSSP), a computer program that was used to evaluate potential process configurations. Based on the results of a regulatory review, pilot testing, and computer simulation results, DSM decided to build a new tank-based wastewater treatment plant.