Fabrication of adsorptive mixed matrix membranes by embedding modified montmorillonite with folic acid into polysulfone for lead removal

Neat and folic acid modified montmorillonite, Mt and Mt-FA, were embedded into polysulfone (PSf) to prepare adsorptive mixed matrix membranes (AMMMs) for lead removal from contaminated water. Prepared membranes were characterized by FE-SEM, pure water flux and contact angle measurement. Equilibrium adsorption capacity and adsorption kinetic of AMMMs were determined using batch adsorption experiments. In addition, dynamic adsorption and regeneration studies were also investigated in dead-end filtration setup. Adsorption kinetic of lead was found to follow pseudo-second-order kinetic model and equilibrium data showed good correlation with the Langmuir model for AMMMs. The obtained results revealed that the lead adsorption was favorable for PSf/Mt-FA. Regeneration capability of the Mt-FA embedded PSf membranes was assessed by conducting ten cycles of adsorption-desorption experiments. FA modified Mt provides interesting properties to adsorb lead from water in neutral pH and desorb in alkaline condition due to positive side group. The obtained results confirmed the applicability of the prepared PSf/Mt-FA in lead removal for multiple cycles.