A novel dual-layer, gas-assisted electrospun, nanofibrous SAN4-HIPS membrane for industrial textile wastewater treatment by direct contact membrane distillation (DCMD)

Abstract

In this work, a dual-layer nanfibrous SAN4-HIPS membrane has been fabricated via the gas-assisted electrospinning, and employed for industrial textile wastewater treatment by direct contact membrane distillation (DCMD). The obtained results showed that the new membrane is robust and able to remove the contaminants, remarkably, with almost 99.28 %, 97.93 %, and 100 % reductions for COD, BOD and color, respectively. However, a flux decline of up to 42.58 % was observed after 48 h DCMD process. Concerning the rejection results, it can be concluded that the flux decline is mainly caused by the membrane fouling rather than the partial pore wetting as the membrane remained hydrophobic after the 48-h experiment. The surface contact angle reduced from 143.2° to 121.5°. Foulants accumulation on the membrane surface can increase the mass transfer resistance of vapor molecules. This can considerably reduce the productivity. The obtained results were also compared with the literature on the other MD processes, as well as the conventional pressure-driven membrane processes. Further studies on enhancing the membrane surface properties are required to control and reduce the fouling tendency caused by the contaminants in the industrial textile wastewater. This is of crucial for the long-term DCMD performance.