Agro-industrial waste upcycling into activated carbons: a sustainable approach for dye removal and wastewater treatment

Abstract

Abstract: The increasing generation of agro-industrial waste has intensified soil and water contamination, as well as the eutrophication of water bodies, impacting biodiversity and human health. This highlights the need for responsible management to meet Sustainable Development Goals (SDGs) 3, 6, 12, 13, 14, and 15, which promote health, access to clean water, responsible consumption, climate action, and the protection of life on land and below water. This study aimed to produce activated carbon from cocoa, baru, and monguba residues for the removal of contaminants dyes (methylene blue, bromocresol green, and methyl red) presented in wastewater. The three materials were carbonized at 500 ◦C for one hour under a nitrogen atmosphere and activated with H3PO4. The samples were characterized using TGA, SEM, XRD, FT-IR, pHPZC, and ASAP, in addition to conducting kinetic and thermodynamic parameter assays for the dyes. Monguba carbon exhibited the highest pore volume (1.57 cm3·g−1), surface area (1604 m2·g−1), and adsorption capacity for methylene blue and methyl red (50 mg·g−1). The data were analyzed using pseudo-first and pseudosecond order kinetic models. It was concluded that monguba carbon shows potential for the sustainable removal of organic dyes and molecules with similar characteristics in contaminated water or wastewater.