The Application Of PAC-UF In Water Supply

With serious pollution to water resource,the traditional drinking water treatment processes can not meet the more stringent requirement of the drinking water quality standard. So it has been the most important research subject in drinking water treatment field to explore new drinking water treatment process. Ultra-filtration (UF) Process was paid more and more attention because of rapid development of membrane industry and its high removal efficiency to turbidity and virus .UF technology was regarded as"water treatment technology in the 21st Century". It was one of the optimal selection to alternate the conventional drinking water treatment processes. However,the dissolved organic matter removal efficiency was very low in raw water by UF because of the high molecular weight cut-off of the membrane. So the UF membrane can be combined with the powder activated carbon (PAC) to improve the organics removal effect.This topic researched powder activated carbon - ultrafiltration combination technology in water supply, with combined craft treating settled water of second waterworks of Dongjiang water affair group. This experiment focuses on different operating conditions, powder activated carbon - ultrafiltration combination process on the water pollutant removal efficiency of differences. I also examine the different operation conditions for membrane pollution effects and different chemical medicine wash on membrane fouling removal. The conclusions are as follows:1) Ultrafiltration membrane itself has very good removal efficiency to turbidity, effluent turbidity has been stable blew 0.10 NTU, it has nothing to do with the influence of water turbidity. Whether dosing PAC or dosing PAC after running condition of change of ultrafiltration membrane has little influence on turbidity removal.2) Ultrafiltration membrane itself to removal of UV254 and CODMn is not large, the removal rate are less than 30%. As for ultrafiltration membrane dosing PAC can increase the removal of UV254 and CODMn . PAC dosage increases, oxygen increases, reverse-wash cycle shortens, its removal rate also increases.3)Ultrafiltration membrane fouling process is also associated with PAC's dosing . PAC can retard membrane pollution. The larger PAC dosage, the slower the membrane fouling process. Membrane pollution degree and operation condition are concerned. System oxygen supply is larger, the more frequently reverse-wash can defer membrane pollution. The greater filtering flux, the faster membrane fouling.4) Simple physical cleaning cannot eliminate membrane pollution to with ultrafiltration,when membrane pollution rise to a certain extent, for ultrafiltration membrane to chemical medicine wash. NaClO has best cleaning effect on membrane It shows organic caused membrane fouling.5) With same concentration of NaClO solution, immersed ultrafiltration membrane after 2h would eliminate organic pollution. The same soaking time, in a certain concentration, the higher concentration of NaClO solution,the higher removal efficiency to organic, but high levels of NaClO solution can cause damage to ultrafiltration membrane.6) After ultrafiltration membrane pollution, through a wash and chemical cleaning, TMP can basically be recovered to the initial value, it shows that ultrafiltration membrane used in experiments has better anti-pollution performance, PAC - UF process has a long-term stable operation.