Removal of Ag and Cr Heavy Metals Using Nanofiber Membranes Functionalized with Aminopropyltriethoxysilane (APTES)

Background: The main aim of this study is to investigate the effects of electrospinning and filtration process parameters such as polymer solution concentration, the initial concentration of metal solution and the pH of solution on the adsorption of Ag and Cr. Methods: In this investigation, firstly, nylon 66 nanofiber membranes were prepared by electrospinning of nylon 66 solution in formic acid/chloroform mixture with the average diameter of 146.68-760.83 nm. Then, the nanofibers were functionalized with Aminopropyltriethoxysilane (APTES) that had an amine group suitable for metal adsorption due to their high adsorption affinity for heavy metal ions. Silver and chrome that are two harmful heavy metals were chosen. The cross flow recirculation filtration set-up was employed. Results: Under optimum condition, the maximum efficiency of the absorption of silver and chrome was 99.97% and 93.06%, respectively. Filtering mechanism of the membrane were blocked the pores and the Freundlich isotherm was found to well represent the measured adsorption data based on the higher coefficient determination (R-2). Conclusion: The maximum adsorption capacity of Ag and Cr by Freundlich model was 1946.91 and 650.41 mg g(-1) respectively, showing a high capacity to work.