Characterization of fouling processes in ceramic membranes used for the recovery and recycle of oil sands produced water

Abstract

In light of the technical challenges associated with performance degradation of ceramic membranes applied to the treatment of produced water, a study aimed at characterizing the nature of fouling was conducted.Tubular γ-alumina multilayered membranes with titania selective layers used for the treatment of two oil sands impacted water feeds were considered. The first, labelled ‘oily water’, consisted of physically-separated water and bitumen fractions. The second, representative of steam-assisted gravity drainage (SAGD) process water, was mainly an oil-in-water emulsion.Saturation of the selective layer through bitumen entrapment had an irreversible impact on the physical integrity of the membrane after treatment of the oily water. Treatment of the SAGD feed produced fouling characteristics typically expected in crossflow membrane filtration, and surface modifications to optimize separation of the oil droplets from the surface and pore percolation of the water phase should be effective to improve performance. Surface foulant accumulation was strongly controlled by linear defects resulting from solvent evaporation during sol-gel fabrication of the selective layer. A better understanding of the impact of such defects on fouling seems necessary. Finally, partial replacement of titania by crystalline BaSO4 suggested that other types of selective layers should be considered for a feed containing Ba.