Decoloration efficiency of the three ferric coagulators can be expressed in such an order as PFS>FeCl_3>FeSO_4.With the help of coagulant aid,the mean decoloration rate can rise as high as 94.3%,and the removal efficiency of COD reaches 74%.

• 三种铁盐的脱色次序是:PFS(聚铁)>FeCl_3