Proceedings of the 2022 Mississippi Water Resources Conference

Year: 2022 Authors: Zhang X., Karunaratne T., Zhang J.

Owe to the high reactivity and uptake capacity, zero-valent iron nanoparticles (nZVI) are a type of widely used engineering nanomaterial for heavy metal removal. However, nZVI suffers severe agglomeration and rapid passivation issues that impede its practical application for water remediation. Biochar, produced from biomass thermal conversion, has been recognized as a good carrier for nZVI to alleviate its aggregation issues. Herein, we report the in-situ synthesis of biochar supported graphene-shelled nZVI (BC-G@Fe0) through the carbonization of iron salt impregnated biomass. Biochar was served as the support material to prevent nZVI from aggregation, and graphene shell was served as the protecting agent to protect nZVI from rapid passivation. The structure and morphology of BC-G@Fe⁰ are characterized by X-ray spectroscopies and electron microscopies. The performance of BC-G@Fe⁰ for heavy metal removal was evaluated through batch adsorption experiments. The effects of carbonization condition and iron loading ratio on the formation of BC-G@Fe⁰, as well as heavy metal uptake capacities, were investigated. This study demonstrated a new type of nZVI sorbent, BC-G@Fe⁰, with enhanced dispersibility and stability for water remediation.