Mitigations of humic acid fouling of polyethersulfone microfiltration membrane enhanced by TiO2 nanoparticles

초록

In this study, we have investigated humic acid fouling of polyether sulfone(PES) microfiltration(MF) membrane enhanced by deposition of TiO2 nanoparticles. Effect of TiO2 deposited membrane on the humic acid fouling has been observed as a function of crystal structures of TiO2 nanoparticles and solution chemistry including pH and divalent cation such as calcium. Our results showed that TiO2 deposited membrne could mitigate the membrane fouling significantly and this effect was strongly dependent upon crystal structures of TiO2 nanoparticles and water chemistries. Fouling mitigation effect was almost negligible with anatase TiO2-deposited membrane at lower pH without calcium while the effect became more pronounced at higher solution pH. Addition of calcium also provided beneficial effect on the fouling mitigation with anatase TiO2-deposited membrane as solution pH increased, suggesting that electrostatic repulsions between organic pollutant and TiO2 surface could play a critical role in mitigating membrane fouling. However, rutile TiO2 having greater density and inertness than anatase TiO2 showed relatively robust effect on fouling mitigation regardless of conditions of solution chemistries.