Mixed-matrix membrane designed with water channels and sieving effect for effective removal of heavy metals

Abstract

The challenge of eliminating heavy metal ions from water has been addressed using Polysulfone (PSf) membranes, which have demonstrated significant potential in treating contaminated solutions. This research aimed to improve the permeability and separation performance of PSf membranes by incorporating Al₂SiO₆ into their structure. The introduction of Al₂SiO₆ into the membrane matrix was achieved through the nonsolvent-induced phase separation (NIPS). The resulting mixed-matrix membrane (MMM) exhibited improved efficiency in water filtration. The inclusion of Al₂SiO₆ led to desirable changes in membrane properties such as hydrophilicity, contact angle and porosity, thereby enhancing the performance of heavy metal ion removal capability. Under a pressure of 2 bar, the mixed matrix membranes achieved rejections exceeding 95 % for lead and 70 % for arsenic. Furthermore, the occurrence of Al₂SiO₆ enhanced the anti-fouling assets of the PSf membrane by increasing its hydrophilic nature and facilitating the development of a hydration layer, which tends to prevent the interactions between the membrane surface and foulant. These properties make these membranes suitable candidates for separating toxic ions from water.