Influence of azo dye-TiO2 interactions on the filtration performance in a hybrid photocatalysis/ultrafiltration process.
Filtration performances of hollow fiber ultrafiltration membrane were investigated in a photocatalysis/ultrafiltration process used for dyeing wastewater treatment. Special attentions were focused on the dye-TiO(2) interactions and their effect on membrane flux and dye rejection. Solution pH was proved to be the predominant force that controlled the interactions by changing the surface charge characteristics of TiO(2) and altering the size and fractal dimension of TiO(2) aggregates which determined the property and structure of deposit layer. Dye-TiO(2) interaction had pronounced effect on membrane flux in adsorptive regions, but this effect became insignificant in non-adsorptive regions. The rejection of dye in the presence of TiO(2) was found to decrease markedly due to the deposition of TiO(2) particles on membrane interface. Bridging effect of TiO(2) between membrane interface and dyes produced by electronic interaction, coordination, and hydrogen bonding was responsible for the decrease in dye rejection. In view of the results presented in this paper, the interactions between pollutant and photocatalysts and their effect on the performance of membrane in hybrid photocatalysis/membrane process should be taken into consideration in the future practice.
College of Chemical Engineering and Material Science, Biological Environmental Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
Jiwei
J
Zhang
Ling
L
Wang
Guoliang
G
Zhang
Zhiyang
Z
Wang
Lusheng
L
Xu
Zheng
Z
Fan
D000327:Adsorption; D001391:Azo Compounds / Q000737:chemistry*; D002384:Catalysis; D003102:Colloids / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D004867:Equipment Design; D008567:Membranes, Artificial; D055668:Photochemical Processes; D014025:Titanium / Q000737:chemistry*; D014462:Ultrafiltration / Q000295:instrumentation*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation*
D001391:Azo Compounds; D003102:Colloids; D004396:Coloring Agents; D008567:Membranes, Artificial; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium