Biochemical treatment requires strict organic loading of inflow.When inflow condition abruptly changed, it is easy for activated sludge to poison and lose activity.And then, sludge become bulky.

• 生化法对进水的有机物负荷要求比较严格，当进水条件突变时，易使活性污泥中毒而失去活性，并发生污泥膨胀。