The use of ozonation for controlling membrane fouling

• Main Authors: Po-Yi Fang, 方柏儀
• Other Authors: Kuan-Chung Chen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/89686504176795978136

碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 98 === In this research, mainly to humic acid model solution was used to investigate the effet of different operating conditions (gas flow, catalyst dosage and ozone dosage), on the control and prevention of a ultra-filtration membrane fouling. 　　Experimental results showed that the permeate flux could be recovered upto 83% when nitrogen gas was injected into the experimental system as the permeate flux declined to 60% of the initial permeate flux. The permeate flux maintained upto 85% if the N2 gas was injected at the start of membrane filtration.The removal efficiencies of DOC and UV254 were both highen than 95% under tested operating conditions. 　　In the study of ozonation combined with UF filtration, the permeate flux could be recovercy upto 98% of the initial permeate flux when O3 was injected into experimental system at the time of permeate flux decreased to 60% of the initial permeate flux. Under the same operating condition, the DOC & UV254 could be removed more then 90% 　　Titanium dioxide and its combination with N2 on the control of UF membrane fouling was also investigated.Permeate flux could be recovered upto 71% and maintained at 83%, respectively, if the TiO2 was added as the permeate flux was dsclined to 60% of the initial flux and the TiO2 was added in the beginning of the fouling eaperiment.When TiO2 and N2 were both added under the same operating conditions mentioned adove, their permeate flux recovery and final permeate flux could be upto 85% and maintained at 90%, respectively.DOC and UV254 were removed more than 90%. 　　In the combination of catalytic ozonation and membrane filition experiment, operimat factors which are O3 dosage and flow rate, and TiO2 dosage were studied.It was observed that the permeate flux recovered upto 90% of the initial permeate flux after TiO2 and O3 were added into the treatment systemin the beginning of filtreation, the final permeate flux could be maintained upto 98% of the inicial permeate flux after 6 hours treatment. The efficiencies of DOC and UV254 were both higher then 90%. 　　The optimal operating condition for both maximizing the permeate flux recovery and maintaining high permeate flux was TiO2 3 g/L dosage, O3 gas flowrate at 150 mL/min, and 2.5 mgO3/L dosage. Under this operating condition, the permeate flux could be recovered upto 98% of the initial permeate flux after the permeate decreased to 60% of the initial flux.If the TiO2 and O3 were added into the treatment system in the beginning of experiment, its permeate flux could be maintained higher than 98% after 6 hour operation. For the removal of DOC and UV254, the optimal operation condition was TiO2 5 g/L dosage, O3 gas flowate 50 mL/min, and 10.0 mgO3/L dosage. Their removal efficiencies could be upto 97% and 100% for DOC and UV254,respective.