Md. Nabul Sardar, Nazia Rahman*, Shahnaz Sultana, Nirmal Chandra Dafader
In this study, a new amidoxime adsorbent based on waste Polypropylene (PP) fabric was prepared for the adsorption of aqueous Cr (VI) metal ions. The pre-irradiation technique was used for grafting Acrylonitrile (AN) onto PP fabric. The grafting reaction was carried out at 80°C in a water bath for 4 hours, utilizing H2SO4 as an additive using 60% AN concentration and a 30 kGy radiation dose. The amidoxime adsorbent was produced by treating Acrylonitrile grafted Polypropylene (AN-g-PP) with NH2OH.HCl and characterized by FTIR, SEM, TGA, and DMA. The adsorption of Cr (VI) was investigated under various contact time, pH, temperature, and metal ion concentration circumstances. Both the Langmuir and Freundlich isotherm models were used to fit the equilibrium adsorption data. The kinetic data follows the pseudo-first-order model, and the estimated and experimental sorption capacities are in good agreement. The thermodynamic data showed that the sorption process was endothermic and spontaneous, taking place by increasing the randomness of the system. Furthermore, the study of the desorption of Cr (VI) from the adsorbent surface and reuse of the adsorbent indicates that the adsorbent can be applied effectively for the efficient removal of Cr (VI) ions from aqueous solutions.