Potential use of membrane bioreactor to treat petroleum refinery effluent: comprehension of dynamic of organic matter removal, fouling characteristics and membrane lifetime.

This study aims to evaluate membrane bioreactor (MBR) performance in a pilot scale to treat petroleum refinery effluent, and has been primarily focused on (1) investigation of dynamics of organic matter removal; (2) characterization of membrane fouling under real hazardous events; (3) evaluation of the effect of fouling on membrane lifetime; and (4) estimate the membrane lifetime. The results have shown that the MBR was able to effectively reduce COD, NH3-N, turbidity, color, phenol and toxicity, and bring them to the levels required to meet disposal and non-potable water reuse standards. The FTIR results showed that organic matter was removed by biological oxidation and/or retained by adsorption in the biological sludge, or retention in the UF membrane, and that SMP was produced during the treatment. In terms of membrane permeability, the results showed that soluble fraction of mixed liquor contributed significantly to membrane fouling. And finally, considering the concept of lifetime based on permeability decline, a membrane lifetime of 7 years is expected.