Removal of aqueous vanadium(V) by green synthesized iron nanoparticles supported on corn straw biochar

Iron nanoparticles supported on corn straw biochar (PE-FeNPs@BC) were used to remove V(V). This material was prepared by using Yali pear peel extract-supported iron nanoparticles (PE-FeNPs) as the functional body and corn straw biochar (BC) as the support. The synthesis conditions such as Fe/C mass ratio and synthesis temperature were optimized. The material was characterized by SEM-EDS, FTIR, XRD, and XPS. The results showed that particle agglomeration was reduced, and the dispersion was improved after PE-FeNPs were supported on BC. The removal effect was better in the pH range of 2-6, and the removal efficiency was the highest at pH 3.7. At 25 celcius and pH 3.7, the maximum adsorption capacity qm of V(V) was 362.7 mg/g, and 95.1 % of 90 mg/L V(V) was removed. The coexisting NaCl or NaNO3 had a weaker effect on the removal of V(V). The adsorption reactions followed the pseudosecond-order model and Langmuir model, and chemical adsorption was the dominant process. The main reaction mechanism of PE-FeNPs@BC with V(V) was as follows: adsorbed V5+ was reduced to V4+ by Fe-0 and Fe2+ and then removed by co-precipitation in the forms of xFe(2)O(3)yV(2)O(5)center dot zH2O and VO2 center dot H2O. This study promotes the reuse of waste pear peel and can provide an environmentally friendly method for removing V(V) pollution. (C) 2022 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.