Hybrid ionogel membrane of PVDF incorporating ionic liquid-reduced graphene oxide for the removal of heavy metal ions from synthetic water
Humaira Razzaq, Amna Siddique, Sobia Farooq, Shumaila Razzaque, Basher Ahmad, S. Tahir, Hifza Nawaz
Abstract
The biggest challenge around the world is water contamination by heavy metal ions. The detrimental effects of heavy metals on humans as well as on aquatic ecosystems are of great concern. In this regard, membrane technology is playing its role in the separation of these non-biodegradable heavy metal ions from the waste water, though improvement in the technology is still the need of time. The present work deals with the novel strategy of developing PVDF/rGO nanocomposite membrane with the inclusion of IL via phase inversion method to remove heavy metal ions. Inclusion of rGO and IL as filler into the PVDF hydrophobic matrix improved the antifouling characteristics and solvent contents of the hybrid ionogel membranes. In addition, the decrease in the contact angle from 90° (Pure PVDF) to 46° (PVDF/IL/rGO) was observed pointing towards the hydrophilic nature of the resulting membranes. Among various compositions, 0.5 w/v % rGO demonstrated maximum efficiency by removing up to 90% of various divalent cations including Cu2+, Cd2+, Zn2+, and Mn2+.The flux recovery ratio was observed to be 94% after testing the membrane several times. Up to 70% removal of As3+ from the same membrane is a hope to design a membrane with improved efficiency for removing As3+.