Study on micro-polluted raw water treatment by rectangular biological sedimentation tanks

Two reactors simulated rectangular sedimentation tank were used to treat micro-polluted raw water under same conditions. The reactor No.l simulated rectangular sedimentation tank and rectangular biological sedimentation tank was simulated by the reactor No.2, in which three dimensional elastic fillers were hanged. The process of biofilm developing in the reactor No.2 was researched to determine the optimal retention time of the reactor No.2. After determine the best retention time, comparing ammonia, CODMn, turbidity and other water quality indicators in the two reactors that operated steadily was used to compare the treatment effect of organic. Then, the factors that affect the removal of ammonia were analyzed. The results show that the reactor No.2 could hang the biofilm naturally and successfully and its optimal retention time is 1.5h. In the process of stable operation, the removal rates of ammonia, CODMn, turbidity in the reactor No.2 are 30.07%, 21.78% and 76.76% respectively that are all above the reactor No.1. So hanging the biofilm in the rectangular sedimentation tanks to treat micro-polluted raw water has a certain research value.