Operation Analysis And Development Trend Of Sewage Treatment Plant In Shanghai

The sewage treatment system with layoutn of "6 catchment area and 53 sewage treatment plant” has been constructed in Shanghai nearly 100 years after the first sewage treatment plant established in 1921.With the subsidy policy from Shanghai government,all the sewage treatment plants work properly in suitable sewage treatment process and keep effluent can reach the discharge standard in recent years.However most sewage treatment plants in Shanghai still need to be reformed to meet a upgrading standards from “Action Plan for Prevention and Control of Water Pollution”.Before all the Standards upgrading Projects begin,it is a meaningful effort to learn from the history and the operational state today.Based on overall situation analy and typical instance on pollutant reduction and energy consumption,we find that most sewage treatment plants work at a higher pollutant reduction rate than their design standard with subsidy.However as the higher treatment standards the sewage treatment plants use,the extra energy consumption for the extra pollutant reduction shows lower marginal effect.The analysis on sewage treatment process also shows that Carrousel oxidation ditch and A/A/O series process which is widely used in Shanghai performed excellent in both pollutant reduction capability and energy consumption.However it need to be considered that some sewage treatment plants still choose A/A/O series process(with high processing load)to treat the low carbon-nitrogen ratio sewage in some district.