Performance of hydrolysis and acidogenosis-A2O integrated reactor in treatment of sewage

摘要

In this study, an opposite folded plate hydrolysis and acidification-A2O integrated reactor was designed to trot low strength sewage in north China. The results of 12 month indicated that the start-up process lasted 50 days;the optimal hydraulic retention time (HRT) was 8h;the optimal sludge retention time (SRT) was 15d;the optimal influent COD concentration was 240～600mg/L;the optimal mixed-liquor return ratio (r) -sludge return ratio (R) was 250％-100％. Under these conditions as above, the COD, TP and TN removal rates were 96.84％, 67.55％ and 81.92％ at (25+2)℃, respectively. When the temperature decreased to 7℃, the COD, TP and TN removal rates decreased to 86.35％, 50.25％ and 65.68％ respectively. According to the performance of this integrated reactor, the application this technology to treat low concentration sewage at low temperature in north China is feasible. The saving in energy and consumption amounted to 30％ when apply this integrated reactor to treat low concentration sewage under the condition that bio-degradation soluble organic matter of A2O was enough. Based on the results of trial, the mechanisms of higher integrated reactor efficacy in treatment of low strength sewage were owed to high eff~cient mass-transfer of hydrolysis and acidification stage and the hybrid actived sludge-contact oxidation in aerobic tank of A2O stage.