A Novel Designed Nanofibrous Pan Ultrafiltration Membrane Embedded with Zif-8 Nanoparticles for Effective Removal of Congo Red, Pb(Ii) and Cu(Ii) in Industrial Wastewater Treatment

Abstract

An innovative hollow fibrous Polyacrylonitrile (PAN) membrane modified with ZIF-8 nanoparticles (NP), ZIF-8/PAN composite membrane, was developed in this study, via electrospinning, which was used for the first time to adsorb Congo red (CR), Pb(II) and Cu(II) ions in industrial wastewater. The obtained ZIF-8/PAN membrane showed the high adsorption efficiency of CR, Pb(II) and Cu(II) of 89%, 92% and 76%, respectively. ZIF-8 nanoparticles and its well distribution determine the adsorption capabilities of pollutants on the composite membrane. From experimental investigation, theoretical DFT calculation and MD simulations, it was unraveled that CR adsorption onto ZIF-8 NP was mainly ascribed to electrostatic interaction, while ion exchange combine with physisorption adsorption contributed dominantly to the removals of Pb(II) and Cu(II). The effects of initial pollutants concentration, adsorbent amount, and pH on the adsorption of CR, Pb(II) and Cu(II) by ZIF-8 nanoparticles were evaluated, to optimize the adsorption condition parameters for composite membrane. This work not only develops a nanofibrous ZIF-8/PAN composite membrane for efficiently removals of pollutants in industrial wastewater, and also reveals the underlying mechanisms of pollutants rejection/adsorption by the ZIF-8/PAN membrane, both which provide important understanding on fibrous materials design for efficient heavy metals and dyes removals in industrial wastewater treatment.

Keywords: adsorption, Composite membrane, DFT calculation, Electrospinning, MD simulation, Zeolitic imidazole framework