Efficient Removal of Cr(VI) by Bamboo-Derived Biochar Supported Nano Zero-Valent Iron: Insights into Performance and Mechanism

The environment and human health are seriously threatened by the highly hazardous and continuously accumulating pollutant known as hexavalent chromium [Cr(VI)]. Therefore, research on more affordable and ecologically friendly remediation agents is desperately needed. This study employed bamboo as a carbon source to produce nZVI-loaded BC materials (nZVI@BC), which would be then used to mimic the remediation of wastewater contaminated with Cr(VI). The morphological structure, chemical composition, functional group, and electron transfer characteristics of the materials were analyzed using SEM, TEM, EDS, Mapping, FTIR, XRD, XPS, and Tafel. The outcomes demonstrated that nZVI was successfully loaded onto BC, which reduced nZVI agglomeration and oxidation, and improved its reactivity and electron transfer rate. The optimal synthesis conditions for nZVI@BC were determined to be a BC pyrolysis temperature of 700 °C and a Fe/C mass ratio of 1:1. The nZVI@BC achieved a removal of 99.80% for Cr(VI), representing a 46.31% improvement compared to nZVI alone. The pseudo-second-order and Langmuir models were more consistent with the adsorption of material. The thermodynamic analysis revealed that the elimination of Cr(VI) was a spontaneous endothermic reaction. The potential removal techniques employed by nZVI@BC include adsorption, reduction, and co-precipitation. Overall, these findings suggest that the synthesized nZVI@BC material shows great potential for effectively treating Cr(VI) in contaminated water.