Effect of operation paramaters on the filtration behavior in microfiltratration of TiO2 suspended

Abstract

The photocatalytic reaction using TiO₂ suspended to degrade the residues of toxic organic compounds has been extensively studied, but the ultilization of this process has not been recorded on an industrial scale. One of the primary reasons is the separation of TiO₂ catalyst from the treated solution mixture. Conventional mechanical separation methods such as centrifugation, flocculation-deposition do not allow for thorough separation and catalytic reuse, whereas the microfiltration / ultrafiltration membrane process has been demonstrated to be capable of composting isolates very suspended particles. Accordingly, in this study, an experimental system separating TiO₂-P25 suspension by microfiltration membrane 0.2 µm on laboratory scale was set up. Effects of operating factors: TiO₂ concentration, pH value, transmembrane pressure and crosss flow velocity were investigated. Result shown that TiO₂ concentration greater than 1 g / l will fundamentally diminish the permeate flux, futhermore, in the transmembrane  pressure differential (∆P) fluctuating from 0.3 to 1.2 bar, the relationship between J and ∆P is a linear relationship. In addition, the study likewise shown that the formation of the cake layer (scale) on the membrane surface is the fundamental driver of the permeate flux degradation over time. These results are the basis for integrating membrane and photocatalytic processes into a complete system for degradation toxic organic compound residues.