BIOCHARS FROM RESIDUAL WASTE TO THE TREATMENT OF WATER

This research investigates the adsorption capacity of CO₂-activated biochars derived from second-generation agricultural waste, specifically pistachio hulls and walnut shells, for the removal of pesticides such as atrazine and other pollutants as heavy metals from water. This study highlights the importance of upcycling agricultural residues into valuable and sustainable materials for water treatment solutions, addressing both waste management and environmental remediation challenges. Biochars were prepared under varying pyrolysis conditions at 500°C and 750°C and subjected to acid washing to optimize their adsorption properties. Characterization techniques, including FT-IR, TPD, nitrogen physisorption, and elemental analysis were employed to evaluate the influence of pyrolysis temperature, acid-washing, and the inherent chemical composition of the biomass on the biochars' properties This research aims to evaluate the adsorption effectiveness of these biochars, and maximizing adsorption capacity, providing insights of the surface chemistry and structure. Adsorption tests demonstrated that the biochars achieved high removal efficiencies for atrazine, with results comparable to those of commercial activated carbon, walnut shell-derived biochar showing a competitive performance. The findings suggest the potential of using waste-derived biochars as high-performance adsorbents, contributing to circular economy initiatives and eco-friendly water remediation.