Fouling study of TiO2–boehmite MF membrane in defatting of whey solution: Feed concentration and pH effects

Membrane performance during whey treatment is typically limited by fouling. This work examined the use of microfiltration TiO2–boehmite ceramic membranes for defatting of reconstituted whey solution. Initially, tubular ceramic membranes were prepared by gel-casting, followed by dip-coating method. SEM images indicated smooth, crack-free TiO2–boehmite layer on α-alumina support. The effects of physicochemical conditions (feed pH and concentration) were evaluated by measuring the permeate flux. The optimum condition was achieved at feed concentration 5.0 wt% and pH 7.0. Individual resistances were evaluated by resistances-in-series model and the governing fouling mechanisms were also investigated using linear forms of classic models as well as combined models. In most of the experiments, the classic models provide a transition from the pore blockage to cake filtration. In combined models, however, the “cake filtration-complete blocking” model was in good agreement with the experimental data. Moreover, alkaline solution gives the best performance for cleaning the fouled membrane.