Optimizing Electrodialysis Desalination: A Sustainable Approach Using Heterogeneous Anion Exchange Membranes Modified by PANI/GO Composite Nanoparticles Document Type : Original Article

Electrodialysis has proven to be a sustainable method for desalination, particularly as a post-treatment step for wastewater or seawater. In this study, novel heterogeneous anion exchange membranes were developed by a solution casting method. The membranes consisted of a mixed-matrix composite of polyaniline (PANI) and graphene oxide (GO) nanoparticles within a polyvinyl chloride (PVC) and tetrahydrofuran (THF) matrix. The prepared samples were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared spectroscopy (FTIR). The addition of PANI/GO in the membrane matrix led to the development of a denser structure of the modified membrane. Response Surface Methodology (RSM) was employed to optimize the operating variables, i.e., feed concentration and voltage, relevant to the process. An extraordinary separation efficiency of 91.45% was achieved by the PANI-co-GO/(PVC/THF) composite heterogeneous anion exchange membranes. Under specific operating conditions, the membrane exhibited a flux of 9.1 × 10⁻⁵ mol/m²⋅s and an ionic permeability of 9.4 × 10⁻⁷ m/s. These values were obtained at feed concentrations and applied voltages of 5700 ppm and 11.85 V (for separation efficiency), 19925 ppm and 12 V (for flux), and 25000 ppm and 9.05 V (for ionic permeability), respectively. To maximize the multi-response variables of separation efficiency, flux, and ionic permeability, the optimal operating conditions were determined. The optimum feed concentrations and voltage were determined to be 21,100 ppm and 11.53 V, respectively. The model predicts a separation performance of 62.30%, a flux of 8.94 × 10⁵ mol/m² s, and ionic permeability of 8.35 × 10⁷ m/s under these optimum conditions. These optimized conditions provide a promising framework for achieving the desired separation performance.