Performance study of ceramic microfiltration membrane for oily wastewater treatment

Cross-flow microfiltration (MF) processes were studied with oily wastewater using a ceramic (α-Al2O3) membrane with 50 nm pore size. The influence of parameters such as transmembrane pressure (TMP), cross-flow velocity (CFV), oil concentration in feed, pH and salt concentration on the separation behaviors were investigated by the measurements of permeate flux, total organic carbon (TOC) removal efficiency, and size and zeta potential of the emulsion droplets. The results showed that there were different degrees of effect on the permeate flux by these parameters. The TOC removal efficiencies higher than 92.4% were achieved under all experimental conditions. A non-steady model of the accumulation volume of permeation was developed. It was found that the predicted values from the model were in good agreement with the experimental results. A sensitivity analysis (SA) of the model was also conducted to identify the degree of influence of the parameters on the accumulation volume of permeation. The results showed that the accumulation volume of permeation was significantly affected by the transmembrane pressure, indicating the model was reliable.