Fabrication and characterization of Multi-Walled Carbon Nanotubes (MWCNT) / Polyvinyl Chloride (PVC) polymer inclusion membrane for Zinc (II) ions removal from aqueous solution

The presence of heavy metals in electronic waste water has led researchers to develop the best method to overcome the alarming effect of heavy metals on living creatures and environments. Therefore, an approach to improve the polymer inclusion membranes (PIMs) was applied using nanoparticles, multi-walled carbon nanotube (MWCNT) as an additive in the PIMs to strengthen the properties and enhance the transport performance of the membrane. In this study, PIMs were utilized as an intermediate membrane to promote the removal of zinc (II) ions from the feeding phase to the receiving phase. The optimal PIM formulation was identified by fabricating the membrane at poly (vinyl chloride) (PVC) base polymer of 18%, dioctyl phthalate (DOP) plasticizer of 1% and bis-(2-ethylhexyl) phosphate (B2EHP) extracting agent of 30%, and the PIM was subsequently fabricated at different MWCT concentrations of 0.5-2.0 % to investigate the efficiency of membrane to remove zinc (II) ions using atomic absorption spectroscopy (AAS). The characteristics of PIMs were determined by scanning electron microscopy (SEM), contact angle, water uptake, and porosity while the chemical characteristic was carried out using fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and ion exchange capacity (IEC). The performance of fabricated PIMs was carried out to obtain the highest removal of zinc (II) ions from an aqueous solution under different conditions of initial feeding phase and receiving phase concentrations at 5-50 mg/L zinc nitrate solution and 0.1-2.0 mol/L nitric acid, respectively. In addition, the kinetic modelling on zinc (II) ions removal by the fabricated PIMs under different conditions was also conducted to acquire the mechanism of the membranes. It was found that the optimal PIM with 30% B2EHP content (R5 membrane) was improved with 1.0% MWCNT (W3 membrane) at 30 mg/L of initial zinc (II) ions concentration and 1.0 M receiver solution for 7 hours at pH 2, yielding the highest percentage of zinc (II) ions removal of 99.44%. In kinetic modelling, the kinetic data were best fitted using pseudo-first-order kinetic model (PFO). In addition, the permeability and flux of R5 membrane at optimum conditions were 1.0049 ms-1 and 0.0486 molm−2 s −1, respectively whereas the permeability and flux of W3 membrane at optimum conditions were 0.053 ms-1 and 0.0532 molm−2 s −1, respectively. In conclusion, the zinc (II) ions removal transport was improved with fabricated MM-PIM of 1.0% MWCNT loading at 30 mg/L of initial zinc (II) ions concentration and 1.0 M receiver solution. Hence, the polymer inclusion membrane with nanoparticle has the potential to recover heavy metal from electronic industry.