By mixing nano-particles of Al2O3 and TiO2 into the casting solution

the nano-modified PVDF flat ultrafiltration membranes with different nano-particle aggregates and proportions were prepared by means of the immerged gel phase inversion process.The effects of different nano-particle aggregates and proportions on membrane performance were discussed.The modification membranes were investigated with SEM and XRD.These modified membranes were used to dispose of the typical oily sewage from coastal oil depot.The hydrophilicity of membrane and its anti-fouling property were improved significantly.The toughness and strength of the membrane were improved effectively which tensile rupture elongation of membrane showed a maximum increase of 6.75% and tensile strength a maximum increase of 43.3%.The suitable total content of nanometer particles was 3% and the best proportion of two nanometer particles was 1:2.Optimized modified membrane showed good treatment for oily wastewater from coastal oil depot.The content of suspended solids in the effluent was less than 0.4 mg·L-1

the content of petroleum hydrocarbon was less than 0.5 mg·L-1

COD was between 60—70 mg·L-1

complying with discharge standard.