PVA / chitosan / teos hybrid membrane for copper and ferum ions removal / Nurul Aida Sulaiman

The removal of ferum (Fe) and copper (Cu) metal ions from industrial wastewater is a crucial due to its harmful effects on human health and living organisms in the environment. There are various methods used in order to solve this problem, such as ion – exchange, chemical precipitation, adsorption and membrane technology. Membrane technology is an attractive method compared to the other methods due to its high efficiency of metal ions removal. However, this method has its drawback such as membrane fouling. Thus, in this study a new composite membrane is fabricated to remove copper and ferum ions. The composite membrane consist a thin layer of hybrid membrane as a barrier layer and polysulfone (psf) as a support layer. During the formulation of hybrid membrane, a polymer blend of poly(vinyl alcohol) (PVA) with chitosan (cs) was chosen as organic polymer and it was cross-linked with tetraethylorthosilicate (TEOS), using sol-gel method to prepare the hybrid membrane. Concentration of TEOS cross linker was varied at (0wt%, 1wt%, 3wt% and 5wt%) and chitosan was varied at (1wt%, 2wt% and 3wt%) respectively with fixed concentration of poly(vinyl alcohol) (PVA) solution (10wt%). These membranes were characterised using various tests such as fourier transform infrared spectroscopy (FTIR), thermal analysis via thermogravimetry analyzer (TGA) and differential scanning calorimetry (DSC), mechanical strength, water contact angle, swelling measurement and anti-fouling behaviour. Results showed that, the composite membrane was successfully formulated due to its great characteristics in term of thermal stability, mechanical strength and anti-fouling properties. It also exhibit better anti – fouling performance where it resulting lower flux declining rate and higher flux recovery rate with and without natural organic matter (humic acid). Besides, it showed a great performance where > 90% copper and ferum ions could be removed from the feed solution at ≥ pH 7. The thin film composite membrane with 3wt% TEOS (M2) exhibits a rejection > 80.0% of copper and ferum ions from industrial wastewater.