Trametes suaveolens-derived biochar loaded on nanoscale zero-valent iron particles for the adsorption and reduction of Cr(VI)

The green reduction method uses pomegranate peel extract as a reducing agent to prepare nZVI on a Trametes suaveolens biochar(T-BC/nZVI) carrier for the removal of hexavalent chromium in the aqueous solution. The effects of several factors, including different ratios between m(CS) and m(Fe), different initial Cr(VI) concentrations, pH, and temperature, were evaluated. When the dosage was 5 g/L at pH = 2 and the initial Cr(VI) concentration was 50 mg/L, the removal of Cr(VI) efficiency was approximately 100% within 90 min. Cr(VI) removal of T-BC/nZVI composites conforms to the quasi-secondary kinetics model, indicating that Cr(VI) removal was dominated by chemisorption. Through a variety of technologies (SEM, XRD, FTIR, BET, and XPS), it was confirmed that nZVI was successfully loaded on the surface of T-BC and effectively removed of hexavalent chromium. The removal mechanisms of Cr(VI) by T-BC/nZVI composites involve multiple processes (adsorption, reduction, and co-precipitation). Graphic abstract