Crosslinked polyethylenimine/polyacrylonitrile blend membrane for multifunctional adsorption of heavy metals and endocrine disrupting chemicals in solution

A novel polyethylenimine/polyacrylonitrile blend membrane (PEI/PAN) was synthesized via crosslinking technology for removing multiple kinds of heavy metals and endocrine disrupting chemicals (EDCs) from aqueous solution including Cu(II), Cr(VI), bisphenol S (BPS), and 2,4-dichlorophenoxyacetic acid (2,4-D) in batch mode. Several characterization techniques were applied to identify the morphological and physic-ochemical characteristics of the synthesized PEI/PAN. The results show that the maximum adsorption capacities of Cu(II), Cr(VI), BPS, and 2,4-D reach up to 97.6, 136, 318, and 1303 mg/g at pH of 2.50, 4.89, 4.95 and 2.84, respectively, whereas the presence of salinity in the solution has affected the adsorp-tion process. Moreover, the uptake of Cu(II) is more in line with Elovich kinetic model, and the kinetic processes for Cr(VI), BPS and 2,4-D can be described by the pseudo-first-order model. Freundlich model is more suitable for describing the adsorption isotherm behavior of PEI/PAN toward Cu(II) and Cr(VI), and Koble-Corrigan model can describe the adsorptive equilibrium processes for BPS and 2,4-D. Thermodynamic parameters are speculated that these adsorption processes are spontaneous and entropy-increasing, with endothermic processes for elimination of Cu(II), Cr(VI), and 2,4-D, while that of BPS is exothermic. PEI/PAN has possessed good reusability after five reuse cycles and has antibacterial property against gram-positive S. aureus. These adsorption processes may mainly occur due to the com-plexation for Cu(II), electrostatic force for Cr(VI), hydrogen bonding for BPS, as well as electrostatic attrac-tion and hydrogen bonding for 2,4-D. Therefore, PEI/PAN membrane exhibits great potential to purify the wastewater polluted with heavy metals and EDCs. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

The novel PEI/PAN blend membrane synthesized via crosslinking technology showed high adsorption efficiency for multiple heavy metals and EDCs, making it suitable for wastewater treatment with good reusability and antibacterial properties.