Experimental Research On Pollutant Removal From Drinking Water By Ultrafiltration Membrane

Ultrafiltration(UF) can dispose microorganism and organism in the water source and has the price advantage over conventional water treatment process in the lower outflow .So UF is a important process used in water treatment in recent decade years. In order to discover the removal of micro-pollutant in the water source by UF membrane process and offer referential information to the development of integrative drinking water treatment equipments, a great deal of researches in this domain have been done by four kinds of hollow fiber UF membrane filters which consist of different materials and different molecular weight cut(MWC).During the experiments, CODMn,UV254 , and turbidity were used for water quality parameters. The results be shown as following: ①The experimental UF outflow has been observed that the turbidity value always less than 0.1NTU even modified the UF membrane MWC and the inflow turbidity values. ②The performance of removing organism by UF membrane is not so effective, it has been observed that the organism in outflow cannot be controlled. ③The membrane working pressure is the force of filtration mostly. In the initial stages, the effect of separation process depends on the materials of membrane. After a while, the effect of separation process depends on the coagulative and flocculability ability of filtration residue layer. Hence in the test range of MWC has little difference on the separation process of water source after a period .④The hydrophilic UF membrane has stronger resistance to dispose the contamination, as well as the time of forming filtration residue layer is longer. Therefore the PAN60000 UF membrane can't remove organism in the lab initially. So that under the condition of the choice of the UF membrane for disposing the micro-polluting in water source, the factors of the range of MWC according to the water quality of the raw water must be thought about and the choice of the hydrophilic UF membrane is better. Under the condition of varying work pressure and keeping pressure, it can be observed that the following factors influenced the filtration fluxes, which are the working pressure, the inflow concentration, the aperture of UF membrane and the resistance of filtration residue layer. The results be shown below:①The working pressure and aperture of UF membrane are the main factors to control filtration flux initially and filtration residue layer is the main factor when UF membrane filter has run for a period. ② The hydrophilic UF membrane has resistance to dispose the contamination, and therefore the filtration flux can be maintained as a constant for a long time. ③Linear regression method has been applied to the experimental data of inside pressure PS6000 hollow fiber UF membrane filter ,and the UF membrane filtration flux model(JV=ΔP*NTU-0.12CODMn-0.38/1.0519*106μW )is presented. The model shows that in order to obtain a higher filtration flux, the concentration of organism in influent water must be lower and the process should be combined with other water treatment processes such as activated carbon process. ④The working cycle of UF membrane has been found through the graph of filtration flux and working time based on decrease 10% filtration flux.