Innovative PVC/Fe(OH) 3 Ion Exchange Membranes for Efficient Arsenic Removal: Synthesis, Performance, and pH-Dependent Behavior

Arsenic removal from aqueous systems is of increasing concern due to its high toxicity and association with serious health risks, including cardiovascular diseases, hypertension, and various forms of cancer. Ion exchange membranes serve as active separation interfaces in electrochemical systems, such as electrodialysis, offering a cost-effective and efficient strategy for the selective removal of arsenic from aqueous solutions. The focus of this research is on diverse membranes for cation-selective exchange that were developed and modified with Fe(OH) ₃ nanoparticles using the solution casting technique, based on polyvinyl chloride (PVC). This study investigated the effect of varying nanoparticle concentrations on the electrochemical properties of the membrane, with particular emphasis on its efficacy in arsenic removal. Additionally, the influence of filler additives, casting solution composition, pH levels, and electrolyte concentration on the membrane’s electrochemical behavior was systematically evaluated. The incorporation of Fe(OH) ₃ nanoparticles into the membrane matrix resulted in notable enhancements in membrane potential, ion transport efficiency, and ionic sensitivity. Furthermore, the presence of these nanoparticles significantly increased the ionic flux across the membrane, from 9.28 × 10 ⁵ to 12.6 × 10 ⁵ mol·m ^-2 ·s ^-1 . The modified membranes exhibited enhanced transport efficiency and ion selectivity at pH = 7 compared to other pH conditions. The results further revealed that the membrane's electrical resistance initially decreased significantly with increasing electrolyte pH, followed by a subsequent increase at higher pH levels. The membranes exhibited lower selectivity toward divalent ions in comparison to monovalent ions. Moreover, membranes modified with Fe(OH) ₃ nanoparticles displayed superior electrochemical performance relative to the unmodified counterparts.