FeSO4/KMnO4 Coagulation Process for Purification of Micro-polluted Source Water

A comparative study among FeSO4/KMnO4(0.33 molar ratio between Mn and Fe),FeCl3 and Fe2(SO4)3 was conducted on the purification of micro-polluted Songhua River water.The results show that FeSO4/KMnO4 process greatly reduces the turbidity of the sedimentation effluent,and the settleability of floc is good.This process can improve the removal rate of organics.When the dosage of ferrous sulfate(calculated as Fe) is 12 mg/L,the removal rates of UV254 and TOC by FeSO4/KMnO4 process are 64.9% and 48.7% respectively.Ammonia nitrogen and nitrate nitrogen concentrations are decreased a little with FeSO4/KMnO4 process.The removal efficiency of nitrite nitrogen is negligible.In the presence of potassium permanganate and ferrous sulfate,the residual iron and manganese ions are not increased.