The optimization of a mathematical simulation program to describe the nitrogen removal of the oxidation ditch process

摘要

To achieve new emission standards and enhance the denitrification of the oxidation ditch in the Handan West Sewage Treatment Plant, this research used the ASM Bio-P model based on self-made simulation software to study the optimum operation of the denitrification efficiency. The results indicate that: 1) the volume of the aerobic zone was increased and the volume ratio between aerobic and anoxic zones was controlled to approximately 3:1; 2) the concentration of the dissolved oxygen (DO) in the aerobic zone was increased and was controlled at 1 mg/L in summer and 3 mg/L in winter; 3) the proper sludge retention time (SRT) was controlled and was maintained at 15 d in summer and 20 d in winter; and 4) the appropriate reflux ratio was controlled to 100% and 50% for summer and winter, respectively. The COD, TN, NH_3-N and TP in the effluent reached the first (B) standard of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB18918-2002).