5.as for the second biological contact oxidationpond, the optimal HRT and air/water ration were 2.64h(its ALR 0.78 kg/m3d) and 6 respectfully, the nitrifying effect was better as effluent D0=5~6mg/l.
6.as for the first biological contact oxidationpond, the optimal HRT was 4h(its OLR_(COD) was 3.6~4.1kg/m3d, OLR_(BOD) was 1.62-1.85kg/m3-d), the effect was better when its air/water ration#6 and effluent D0=4.5-6mg/l;
