Hollow-fiber mixed-matrix membrane impregnated with glutaraldehyde-crosslinked polyethyleneimine for the removal of lead from aqueous solutions

Removing heavy-metal ions from wastewater is essential for public health and natural resource management. In this study, we developed an adsorptive hollow-fiber mixed-matrix membrane (MMM) composed of polyethersulfone (PES), as the polymer matrix, and glutaraldehyde-crosslinked (GA-crosslinked) polyethyleneimine (PEI), as the adsorbent, for removing Pb2+. The effect of the impregnated GA-crosslinked PEI on the structural and chemical properties of the membrane was investigated. The introduction of the adsorbent resulted in a sponge-like structure of the membrane and imparted it with hydrophilic properties. Furthermore, it resulted in a positively charged membrane surface at most pH values. Dynamic adsorption–desorption experiments were conducted to evaluate Pb2+-adsorption efficiency. The GA-crosslinked PEI membrane presented a high adsorption capacity (7.81 mg/g) and desorption efficiency (92.8%) in the first cycle. Furthermore, it showed excellent reusability, with no significant change in Pb2+-desorption efficiency (approximately 92%) even after three usage cycles. This study demonstrated the applicability of hollow-fiber MMMs impregnated with GA-crosslinked PEI for the efficient removal of Pb2+.