Coagulation-SBR Combined Processes for the Treatment of Papermaking Wastewater

Both coagulation and SBR are effective techniques for treatment of papermaking wastewater. In this paper, the removal efficiencies of COD in papermaking wastewater are investigated by the processes of coagulation, SBR and coagulation-SBR combined processes. The effects of coagulant type, the dosage of coagulant, pH and stirring rate on treatment efficiency are explored in the paper. The results showed that the PFS (poly ferric sulfate) was more efficient than Fe₂(SO₄)₃ and Al₂(SO₄)₃ in treating papermaking wastewater, and that the dosage of the PFS was the key factor to reduce COD. The combined coagulation-SBR method may effectively be used to reduce COD in papermaking wastewater. Under the condition of the dosage of 5000mg/L and pH of 8.00, the removal efficiency of COD was 95.2%.