Preparation of green magnetic hydrogel from cellulose nanofibril (CNF) originated from soybean residue for effective and rapid removal of copper ions from waste water

At present, people are paying more and more attention to the development of sustainable biological materials. In this study, green magnetic hydrogel was prepared by blending Soybean residue cellulose nanofibrils (CNF)，poly (vinyl alcohol), diatomite and nano-Fe3O4 for Cu2+ removal. Results showed that the decrease of CNF diameter improved the mechanical property and swelling of the magnetic CNF hydrogel (the maximum tensile strength was 2.3Mpa) for better Cu2+ adsorption. Adsorption studies displayed that the adsorption of Cu2+ followed the pseudo-second-order kinetic model, and the adsorption process is mainly chemical adsorption. This work provided a feasible method to fabricate magnetic hydrogel from green renewable resource as a new and promising adsorbent.