Application of a Dynamic Dilution and Decay Method to Calculate Effluent Total Residual Chlorine Limits

摘要

As many Water Resource and Recovery Facilities (WRRFs) across the United States face increasingly stringent effluent criteria, including Total Nitrogen, Total Residual Chlorine and Indicator Organisms, there is a need for a more rigorous and realistic approach for determining plant specific effluent total residual chlorine limits. This paper describes the development and application of a dynamic dilution and decay approach for re-calculating effluent TRC limits based on the actual processes that take place in the chlorine contact tank, the discharge pipe and the receiving water. This new approach was used to recalculate the effluent TRC limits for seven WWRFs, resulting in some plants having significantly higher effluent TRC limits.