PVDF membranes embedded with PVP functionalized nanodiamond for pharmaceutical wastewater treatment

The effect of neat and modified nanodiamond (ND) nanoparticles on the structure and performance of PVDF membranes was studied. ND was first oxidized (O-ND) thermally, then silanized (S-ND) using the esterification reaction by vinyltrimethoxysilane, and finally was PVP functionalized (P-ND) via surface initiated free-radical polymerization method. The results of FTIR analysis revealed that PVP was successfully immobilized onto ND nanoparticles. Different percentages of ND and P-ND nanoparticles were then embedded into PVDF membranes. The results showed that the hydriphilicity and water flux of membranes improved as the percentage of nanoparticles increased. Moreover, the number of pores on the surface of PVDF/P-ND membrane increased in comparison to neat PVDF and PVDF/ND membranes even though the pore size distribution curve of PVDF/P-ND membrane was shifted towards smaller pores. In addition, the presence of ND and P-ND nanoparticles within PVDF membranes increased the portion of beta-phase in the PVDF structure which resulted in abrasion and fouling resistant membranes. The performance of neat PVDF, 1.5 wt. % PVDF/ND and 1.5 wt. % PVDF/P-ND membranes was studied in MBR system with pharmaceutical wastewater feed and it was found that antifouling properties PVDF/P-ND membrane were better than that of PVDF/ND membrane. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.