Application of membrane distillation for the treatment of oil field produced water

Direct contact membrane distillation (DCMD) was investigated for the treatment of oil-field produced water using a hydrophobic polypropylene (PP) membrane with 0.2 μm pore size. The DCMD performance was studied under different feed temperatures ranged from 40 °C to 80 °C while the cooling temperature was maintained at 23 °C. Increasing the feed water temperature resulted in a higher permeate water flux. Stable and reliable DCMD membrane performance was observed for all used membranes. The obtained results indicated the great potential of DCMD to treat hypersaline oil-field produced water with an overall rejection of salts higher than 99.9% and that of total organic carbon (TOC) greater than 93.3%. This was due to the presence of volatile organic compounds in oil-field water. Pre-treatment of produced water using 0.45 μm filter did not show much effect on the DCMD performance. A slight gradual reduction of the permeate flux was observed due to fouling phenomenon. A simple washing the membrane with de-ionized water was found to be an effective method for cleaning the membrane and restoring the permeate flux indicating the absence of irreversible fouling. •Direct contact membrane distillation (DCMD) was investigated for the treatment of oil-field produced water.•Rejection of DCMD of hypersaline was >99.9% and 93.3% for TDS and TOC, respectively.•Feed temperature increased DCMD flux without affecting its rejection.•MCMD fouling was minimal and reversible when treating hypersaline oil-field produced water.