Desalination and heavy metal ion removal from water by new ion exchange membrane modified by synthesized NiFe2O4/HAMPS nanocomposite

Magnetic nickel ferrite (NiFe2O4) nanoparticles were synthesized and then modified by a novel hydrogel based on 2-acrylamido-2-methyl propane sulfonic acid (HAMPS). Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) analyses were conducted to prove the NiFe2O4/HAMPS nanocomposite formation decisively. The effect of NiFe2O4/HAMPS in the matrix of the heterogeneous cation exchange membrane on separation performance was studied. Adding of NiFe2O4/HAMPS into the membrane body up to 1%wt resulted in an increase of sodium flux obviously. The sodium flux showed a decreased trend at higher nanocomposite ratios slightly. Membrane potential, permselectivity, and transport numbers also showed improving trends. Results exhibited more value for Na+ dynamic transport numbers compared to static ones. Membrane water content and porosity increased from 13.07 to 27.7% and 9.6 to 20.2% by utilizing NiFe2O4/HAMPS, respectively. By adding NiFe2O4-HAMPS into the membrane structure a pronounced improvement in membrane mechanical resistance (94%) and chemical stability was observed. Modified membrane containing 1.0%wt NiFe2O4-HAMPS showed effective separation in Pb2+ (98%), Cu2+ (48%), and Ni2+ (34%) removal. This sample also showed highest current efficiency (78.9%) in Pb2+ removal and lowest energy consumption (6.97W/mol) compared to others.