Efficiency Analysis of Advanced Treatment Process and Upgrading Reconstruction of Urban Sewage Treatment Plant

To analyze the efficiency of different advanced treatment processes of sewage treatment plants, two sewage treatment plants with improved A2/O as the secondary treatment process but with different advanced treatment processes (Plant A: MBR process; Plant B: high-efficiency coagulation sedimentation tank + filter process) were as the research objects. Annual monitoring of water quality and drug consumption was conducted to analyze the difference in the treatment efficiency of the two advanced treatment processes. Meanwhile, the treatment efficiency and drug consumption before and after the upgrading and reconstruction of Plant A were compared. The results showed that the removal rates of COD, SS, and TP in plant B were higher than those in process A, while the removal rate of TN was lower than that in plant A. Plant A had fewer structures and a high land utilization rate. Plant B made full use of the carbon source of raw water to reduce the drug consumption of carbon sources, and the filter had advanced treatment of pollutants. The monthly average consumption of PAC and sodium hypochlorite in Plant B were 44.4 g/m3 and 12.3 g/m3, and it was lower than those of Plant A, respectively. Plant A mainly carried out upgrading and reconstruction measures such as increasing the length of the grid bars, reconstructing the control cabinet, and adjusting the operation mode. After the reconstruction, the water production capacity of the MBR membrane was improved, and the monthly average consumption of PAC and flocculant was reduced by 14.6 g/m3 and 2.5 kg/t, respectively.