Synthesis of an electrically cleanable forward osmosis membrane

Abstract

A novel way to remove fouling from forward osmosis membrane is carried out in this research work. Electric field was used as a novel fouling removal option in this research work. Therefore, conductive membrane was prepared with the use of chitosan (CHS), polyvinyl alcohol (PVA), and graphene (Gr). The prepared membrane named as “CHS/PVA/Gr”. Various characterization methods are used to characterized this CHS/PVA/Gr membrane i.e. conductivity, porosity, swelling ratio, water flux measurement, and scanning electron microscopy (before and after fouling). To check the CHS/PVA/Gr membrane performance and fouling behavior forward osmosis (FO) experiments are carried out with distilled water (DI water) and algae-containing water. In FO experiments, as a feed solution algae water (nearby lake water) and as a draw agent, high concentration NaCl solution (4M NaCl) was used. Membrane fouling and draw solution leakage was investigated in this research work by laboratory-scale forward osmosis (FO) setup. The water flux in FO mode was 31.2 Lm−2 h−1 (LMH) (with DI water as a feed) and reverse salt diffusion 0.015 gm−2 h−1 (gMH). The initial FO water flux value is 28.1 LMH with algae-containing water. Intention of fouling removal method is to regain the initial water flux after giving cleaning treatment in IC current the form of elect. After cleaning experiments, the restore water flux values are 14.2 and 22.04 LMH for distilled water and electric field cleaning method, respectively.