The study of PAC-coagulation sedimentation-UF process for treating micro-polluted water

A process of powdered activated carbon (PAC) coagulation sedimentation Ultrafiltration (UF) was used to investigate the effect of removing organic matter in micro polluted water. The results showed that the PAC-coagulation sedimentation UF combined process could remove effectively dissolved organic matter in micro-polluted water. After pre dosing 15mg/L PAC, the whole removal of COD_Mn, UV₂₅₄, DOC was 44.94%, 35.42%, 25% respectively, and it was increased 14.17%, 17.71%, 16.00% compared with the coagulation sedimentation UF process. It was avail to remove small organic molecules by dosing PAC, particularly for organic matter of molecular weight between 1000u and 3000u. The PAC coagulation sedimentation UF process removed DBPs precursors of chloroform in a certain extent and the removal rate of chlorine-dibromo, dichloro, bromine, carbon tetrachloride, bromoform was 31.52%, 4.84%, 16.29%, 15.12% and 28.57% respectively. It was found that hydrophobic organic compounds was the major factor in membrane fouling, PAC coagulation sedimentation UF process could effectively remove hydrophobic organic compounds, improve membrane flux and alleviate membrane fouling.