Advanced hybrid membranes for efficient nickel retention from simulated wastewater

This paper describes the preparation of a new type of hybrid material suitable to be used for the amendment of wastewaters laden with Ni ions relying on two purification principles, mechanical and adsorption. The membranes were prepared using as first component copolymers of acrylonitrile with vinyl acetate, acrylic acid or methacrylic acid. The second component of the developed membranes consisted of powdered activated carbon (PAC), of natural or synthetic origin, used in a content of either 4% or 8%. In this way, separation based on porosity is combined with the adsorptive properties of PAC. Hybrid membranes, prepared by phase inversion, were fully characterized by Fourier transform IR (FTIR) spectroscopy, pure water flux analysis, TGA, SEM, Brunauer-Emmett-Teller analysis and XRD. Moreover, water amendment was also investigated using synthetic water bearing heavy metals, in our case nickel, a laboratory electrodialysis set-up being used for this purpose. FTIR revealed that the use of PAC led to several peaks at low wavelength (900-650 cm(-1)). Pure water flux values vary in a fairly wide range, from 0.02 to almost 1.00, depending on the preparation conditions. It can be concluded that the final properties of the developed membranes may be adjusted by changing either the copolymer or the PAC. An additional control is provided by the amount of PAC. The developed membranes were found to achieve an enhanced release of Ni ions, as the percentage of extraction was at least 51%. (c) 2021 Society of Chemical Industry