| 초록 |
Application of titanium dioxide (TiO2) as suspension in several advanced oxidation processes, involves the important task of separation of TiO2 after photocatalytic reaction, in order to prevent unnecessary secondary pollution. This study deals with the evaluation of separation efficiency of TiO2 in two-stage coagulation process followed by submerged hollow fiber microfiltration (MF) membrane. Turbidity was measured to identify the amount of removal of TiO2. The performance of membrane operation was analyzed based on the nature of permeate flux, which represents the extent of membrane fouling. The results indicate that presence of two stage coagulation significantly improved the performance of membrane operation, compared to the operation in the absence of coagulation. Simple pH adjustment to pH 6.3 (iso electric point of TiO2) in the first stage of coagulation settle almost 90 % of TiO2. Addition of ferric chloride (FeCl3) coagulant concentration of 50 ppm was found to be optimum in terms of further removal of TiO2 and permeate flux development. The point of ferric chloride addition was also found to be very important to minimize the coagulant requirement. |
