Application of thin film composite membranes with forward osmosis technology for the separation of emulsified oil–water

• Study the FO technique for the treatment of a wide range of oil–water emulsions.
• Water flux as functions of feed flow rate and feed concentration has been studied.
• Pure water can be separated from a 200,000 ppm oily feed by FO technique.
• A water flux of 11.8±1.6 LMH can be obtained from a 200,000 ppm oily feed.
• The membrane fouling has been investigated in this study.

Large amounts of oily wastewater have been produced from various industries. The main challenge of oily wastewater treatments is to separate the stable emulsified oil particles from water. Therefore, the aim of this study is to investigate the effectiveness of forward osmosis (FO) processes to treat the stable oil–water emulsions. The FO technique has been demonstrated successfully for the treatment of a wide range of oil–water emulsions from a low to a very high concentration up to 200,000 ppm. The dependence of separation performance on oily feed concentration and flow rate has been investigated. Water can be separated from oily feeds containing 500 ppm or 200,000 ppm emulsified oil at a relatively high flux of 16.5±1.2 LMH or 11.8±1.6 LMH respectively by using a thin film composite membrane PAN-TFC and 1 M NaCl as the draw solution. Moreover, this membrane can achieve an oil rejection of 99.88% to produce water with a negligible oil level. Due to the presence of emulsified oil particles in the oily feed solutions, the membrane fouling has been addressed in this study. Better anti-fouling TFC FO membranes are needed.

Figure optionsDownload high-quality image (258 K)Download as PowerPoint slide