Use of carbon from the agricultural industry for the synthesis of catalysts destined to oxyanions removal from water

Abstract

Remediation of water contaminated with oxyanions is of great importance due to the toxicity and environmental persistence of these chemical species. The present work describes the elimination of diferent oxyanions in water using catalysts supported on active carbon obtained from an agricultural residue (peanut shells, CPeanut) and active commercial carbon (CCom) in order to compare their structural and catalytic properties. The synthesized CPeanut and CCom were fully characterized by surface analysis, TGA, TPR, SEM-EDX, FT-IR, and TEM. It was observed that CPeanut presented similar superfcial characteristics to CCom, being an adequate support to synthesize catalysts. With both carbons, catalysts based on Cu, Pd, and PdCu were prepared and evaluated in the elimination of NO3-, NO2-, and BrO3- from water using H2 as a reducing agent. The bimetallic catalysts prepared on both supports were active in the oxyanions reduction, obtaining good selectivities to the products of interest. In this sense, this work presents a potential re-use of agricultural wastes by preparing activated carbon from peanut shell residues in order to reduce the waste volume generated. In addition, the material synthetized is low cost due to its large-scale production and great availability in Argentina. The carbon obtained from the peanut shells provides a potential application in the environmental remediation of water contaminated with oxyanions.