Organic Matter Molecular Weight Distribution and Process Selection for the Raw Water of East River

The DOM removal efficiency of the East River treatment with the process of conventional coagulation-sedimentation,PAC pre-adsorption coagulation-sedimentation,KMnO₄ pre-oxidation and PAC pre-adsorption coagulation-sedimentation was investigated in terms of molecular weight distribution.The result showed that,the DOC of the East River raw water in flood period was mainly 3 000-10 000 and >10 000,which proportion was 30.8% and 43.2%,respectively.The results of continuous flow dynamic experiment showed that conventional coagulation sedimentation process mainly removed organic matter which molecular weight was more than 10 000.KMnO₄ pre-oxidation and PAC pre-adsorption coagulation-sedimentation process could improve organic matter removal rate of each molecular weight.The DOC removal rate of KMnO₄ pre-oxidation and PAC pre-adsorption coagulation-sedimentation process was 84.0%.The removal rate raised 54.2% compared with conventional coagulation process.KMnO₄ pre-oxidation and PAC pre-adsorption coagulation-sedimentation process can enhance the removal rate of DOM effectively.