Effect of Mineral Oil on Treatment of Sewage from Channel Discharge with Biological Accelerator-Biofilm Process

The research studied enhanced treatment of sewage from discharging points of rivers by biofilm process dosing with enzyme and the effect of mineral oil on removal rates of the main pollution indexes, and investigated promotion effect of enzyme (including the laboratory developed compounded enzyme and the foreign composite enzyme) on treatment of sewage by biofilm process. The research results indicated that when initial concentration of mineral oil was 15mg/L, mineral oil could be degraded at a certain degree, and mineral oil had the negative effect on the removal rate of CODCr and ammonia nitrogen. Meanwhile, the removal rates of mineral oil, CODCr and ammonia nitrogen were higher in reactor B and C than in reactor A, and the removal rates of them in reactor B were similar to them in reactor C, which indicated that enzyme had good promotion effect on biofilm process during the sewage treatment process.