Full-scale Experimental Study On The Characteristic And Operation Optimization Of MUCT Process

The project comes from the "Eleventh Five-Year"National Key Project subproject -- "the whole process of sewage treatment plants energy saving technology integration and demonstration projects".It's based on a series of productive tests that are conducted by the MUCT process (Modified University of Cape Town Process) operating in both the south and the north groups of a certain sewage treatment plant in Shenzhen.The tests have researched the MUCT process removal efficiency on COD, nitrogen and phosphorus, and studied the spatial distribution regularities of substrate under different working conditions to determine a reasonable DO, nitrification liquid reflux ratio and the sludge concentration and reduce the operation energy consumptions by controlling the precise aeration in aerobic zone. The result shows that:The MUCT process is effective in removing the organic matters, nitrogen and phosphorus, the average removal rate of TP, NH₄+-N , TN and CODcr in both the south and the north pools are respectively about 86.63%&88.19%, 90.36%&93.23%, 41.47%&51.24%, 80.00% &79.66%, and the system runs stably.We alse find that inease of DO in aerobic zone can significantly improve the nitrification rate of NH₄+-N, however, the improved nitrification rate will not obvious when keeping to inease the DO in the south and the north pools after the NH₄+-N has achieved the effluent standard, the MLSS has limited influence on the removal rate of NH₄+-N when the DO is sufficient in the aerobic zone; the backwash of nitrification liquid is good for steadying the operation of system and improving the efficiency of nitrogen removal, the removal rate of TN is ineased as the inease of C/N ratio, but it will be deeased when the feeding water load has ineased. It is not conducive for phosphorus removal when the density of NO₃--Nin the anaerobic zone is lower than 1.0mg/L or higher than 2.5mg/L; but in the aerobic zone, as long as the DO is maintained above the 0.5mg/L can the phosphorus be removed, and the ineasing of temperature is good for nitrogen removal, but has little impact on phosphorus removal.Through the rational allocation of water, control DO, speed up the sludge updates and other measures can be achieved optimal operation of the system. Aeration of the aerobic stage modified the implementation of accurate reduced energy consumption, optimal consumption decreased after running blowers 0.0060kW·h/m³, fan integrated power consumption reduced 10.18%, a year savings of electricity 260452.18kW·h.