COMPARISON OF O3 AND KMNO4 IN THE MICROFILTRATION MEMBRANE SYSTEM OF SURFACE WATER

The aim of the study is to explore the effects of O-3 and KMnO4 on organic matter and microfiltration membrane performance. The results showed that pre-oxidation has a great effect on organic matter of raw water and membrane performance. Compared with KMnO4, ozone dramatically changes the structure of organic matters. During 3-5 kDa and near 0.2 kDa molecular weight (MW) distribution of raw water, 3-5 kDa MW organic matter markedly decreased by ozone and changed slightly near 0.2 KDa MW. Ozone markedly transfers the hydrophobic fraction to the hydrophilic fraction. However, MW and the hydrophobicity/hydrophilicity change slightly due to the weak oxidation of KMnO4. The membrane filtration results showed that pre-oxidation can improve membrane flux. It seems that there was an optimal dosage for membrane flux with ozone and KMnO4. Enhancement of the membrane flux by ozone oxidation was far better than that by ICMnO4, which can be confirmed by membrane resistance results and the scanning electron microscope images of membrane-filtrated water samples by ozone and KMnO4 oxidation, respectively. Membrane fouling resistance by ozone oxidation was lower than that by KMnO4, and matter deposit onto the membrane surface by ozone oxidation was larger and looser than that by KMnO4 oxidation.