Impact of Montmorillonite Clay on Polysulfone Mixed Matrix Membrane for Heavy Metal Adsorption

Exposure to high levels of heavy metals exerts serious health hazards to humankind. It is, hence, imperative to limit exposure to heavy metals by avoiding their consumption, direct or indirect, and by appropriately disposing of items that may contain heavy metals. To explore heavy metals removal efficacy, montmorillonite (MMT), a type of clay, was prepared at varying dosages (0.5, 1.0, and 1.5 wt%) to fabricate polysulfone mixed matrix membranes for treating aqueous solution contaminated with cadmium and lead. The mixed matrix membranes are characterized by scanning electron microscope (SEM), Fourier transforms infrared (FTIR), energy dispersive X-rays (EDX), water uptake test, pure water flux calculation, and heavy metal adsorption test. The particle size distribution of MMT is first measured covering the range of 1 to 42 mu m. The FTIR spectra of MMT and MMT-filled membranes indicate that the silica functional group dominates the MMT elemental composition. It is revealed that the modified design improves water uptake by 83% compared to the pristine membrane. The pure water flux of the 1.5 MMM membrane is the fastest among the membrane at similar to 2500 L/m(2)center dot h and is the most porous membrane with a porosity of 10%. Heavy metal rejection measurement shows that the modified membrane can remove cadmium and lead by 3% and 14%, respectively. Furthermore, all prepared membranes show solute water flux of more than 500 L/m(2)center dot h. The incorporation of MMT has successfully altered the polysulfone mixed matrix membrane to become a high-flux membrane capable of treating cadmium- and lead-rich water. Further study is needed to utilize the membrane to treat heavy metal wastewater.