Abstract
Membrane technology has for decades been considered a reliable contaminant remover that does not produce toxic by-products in water treatment. Its separation principle involves applying a semi-permeable membrane to remove, gases, particles, and solutes. PVDF among other polymers has been used to synthesize membranes which are suitable for water treatment. This is because of its excellence aging resistance and high mechanical strength. The hydrophobicity and low selectivity of PVDF has led to incorporating with nanomaterials, which are distributed in the membrane’s matrix. Nanomaterials influences the membrane’s water permeability and solute rejection by changing the membrane’s porosity and pore size.
This work is focussed on the design and synthesis of PVDF membranes incorporated with graphene-based carbon nanomaterials (GO, rGO, MWCNTs and f-MWCNTs) and testing their performance in the treatment of industrial brine. The Hummer’s modified method is used to synthesize GO from graphite and hydrazine hydrate is used for the reduction, a mixture of H2SO4 and HNO3 is used for oxidising MWCNTs under high temperature. The physical and chemical properties of the synthesized nanomaterials were analysed using FTIR, BET, TGA, Raman, XRD, TEM, and CHNS analysis. The membranes were synthesized using the phase inversion method, and physico-chemical properties of the synthesized membranes were analysed using SEM, FTIR-ATR, XRD, and studies on their water contact angle and water intake capacity measurements were done.
All the synthesized membranes showed high water flux and permeate flux when compared to other membranes reported in literature which made them suitable for filtration of large water volume. Rejection rates of salts and TOC were low, and this was associated with larger pore size on the membrane surface.