Optimization of the Parameters Involved in the Removal of Pb(II), Cu(II) and Zn(II) Ions from Aqueous Solutions using Nanofibrous Membrane of Sulfonated Poly (Ethylene Terephthalate)

In this study, sulfonated poly ethylene terephthalate (SPET) nonwoven membrane for heavy metal ion filtration was prepared by electrospining with different conditions and then simulated by wastewater containing metal ion as an aqueous solution. Commonly used for the exclusion of metal ions from wastewater, the ionic interaction between negatively charged matrices and positively charged metal ions has been utilized. The controllable factors i.e., initial concentration, adsorbent amount, pH, and pressure on the efficiency of filtration were optimized in this study. The results showed that the metal ion rejection increased with increasing adsorbent concentration and the pH of solution, while it was decreased by increasing applied pressure and concentration of solution. PH solution was found to be the most effective in the efficiency of metal removal and then adsorbent concentration, initial concentration of metal ion and pressure were affected, respectively. Spectra ATR–FTIR of the samples before and after filtering membrane translocation showed absorption bands, indicating that absroption mainly occurred through the reaction between the metal ion and the polyester sulfonated group. The pollutant removal efficiency (PRE) under optimum conditions was obtained to be 99.7%, 99.32%, and 86.37% for Cu(II), Pb(II) and Zn(II), respectively. The filtration mechanism was determined through blocking law and an acceptable agreement was achieved for internal pore blocking mechanism. Langmuir and Freundlich, which are two equilibrium adsorption isotherms, were fitted to the data. The best fit was related to the Freundlich model in comparison with Langmuir model. By using Freundlich model, the relative adsorption capacity was obtained 595.26, 534.85 and 154.00 mg/g for Cu(II), Pb(II) and Zn(II), respectively.