Preparation and characterization of SiO2/PDMS/PVDF composite membrane for phenols recovery from coal gasification wastewater in pervaporation

Silica (SiO2)/polydimethylsiloxane (PDMS)/polyvinylidene fluoride (PVDF) composite membranes were prepared through a dynamic negative pressure method for phenols recovery from coal gasification wastewater (CGW) in pervaporation process. Multiple techniques including scanning electron microscopy (SEM), water contact angle (WCA) and fourier transform adsorption spectrum (FTIR) were used to examine the surface morphology, hydrophobic properties and functional groups of the modified PVDF hollow fiber membranes, respectively. The effects of SiO2 concentration, coating time and coating pressure on pervaporation performance were systematically studied. The operating conditions obtained are as follows: 12 wt.% SiO2, coating time 60 min, coating pressure 50 kPa. Under the optimum conditions, the phenols flux and separation factor were obtained as 6.55 g m(-2) h(-1) and 2.59, respectively. Results show that separation factor in pervaporation process based on 12 wt.% SiO2 filled PDMS/PVDF composite membranes was about 2.5 times higher than that of the PDMS/PVDF membrane. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.