Comparison between the performances of <scp>PmPD</scp> ‐ <scp>PVA</scp> membrane synthesized by ammonium persulphate with ferric chloride oxidants used for Congo red dye removal

Abstract This work focused on investigating the effect of oxidants and their interaction with the monomer (m‐phenylenediamine) (mPD) on performance of the resulting composite membrane. The synthesized poly(m‐phenylenediamine) (PmPD) and poly(vinyl alcohol) (PVA) were deposited onto flat ceramic support made from pozzolan and micronized phosphate. The difference between the two composite membranes is the oxidant used for the chemical polymerization of mPD monomer. The PmPD used to develop the first membrane in this work was synthesized using ammonium persulphate (APS) oxidant. The second membrane was developed in a previous study using ferric chloride (FeCl 3 ) as oxidant. Although PmPD‐based membranes have been explored, few studies have systematically compared the influence of different oxidants on membrane performance, especially for dye removal. This study addresses that gap by evaluating how APS and FeCl 3 affect membrane characteristics and dye rejection efficiency. The effect of oxidants on membrane properties such as microstructure, wettability, permeability, and filtration performances was investigated. The composite membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X‐ray analysis, and X‐ray diffraction technique. The morphology analysis shows that using APS leads to the formation of uniform microparticles compared to FeCl 3 oxidant. It was proven that the use of APS in the polymerization of the mPD enhances the rejection of the membrane accompanied by with a decrease in permeate flux. It removed up to 99.7% of Congo red under optimal conditions ( Δ P = 3 bar, C = 600, and pH = 4).