Study of microfiltration behaviour of oily wastewater.

Crossflow microfiltration experiments were carried out with oily wastewater using alpha-Al(2)O(3) membranes with 0.05 microm pore size. The influence of parameters such as transmembrane pressure (TMP), crossflow velocity (CFV), oil concentration, pH and salt concentration on the microfiltration behaviors were studied based on 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 membrane separation performance by these parameters. The TOC removal efficiencies higher than 92.4% were achieved under all experimental conditions. A non-steady model of accumulation volume of permeation was developed. It was found that the calculated values were in good agreement with the experimental results. Sensitivity analysis was also conducted to identify the degree of influence of the parameters on the accumulation volume of permeation. The results indicated that the accumulation volume of permeation was significantly affected by the TMP.