Cocoa husk-derived Biochars synthesized at low temperature impregnated with zinc chloride for removal of ibuprofen in different solutions

Abstract

Metabolites and residual compounds from pharmaceutic industry are considered as emerging contaminants and an increasing source of environmental pollution, as they are used by a quantity of people, and due to their physicochemical properties, they are easily transported to hydrological systems and bodies of water. Then, the elimination of this kind of compounds from water by adsorption is one of the most promising techniques. The aim of this research was to study the kinetic and isotherms of ibuprofen adsorption onto low temperature-synthetized activated carbons from cocoa husks (Theobroma cacao) and impregnated with a solution of Zinc Chloride (ZnCl2) at impregnations ratios biomass:solution of 1:2 (CA1:2) and 1:3 (CA1:3). The material source and activated underwent a chemical and textural characterization by elemental analysis, scanning electron microscopy (SEM) and the Brunauer Emmett Teller method (BET), for knowing their morphology, chemical composition, and surface area. Ibuprofen solutions at 20, 30 and 40 ppm were used to perform adsorption tests. The activation of cocoa husk caused an increase in the porosity and surface area of the charcoals, evidenced in the results of the SEM analysis, with CA1:2 being the one that presented such properties in a greater proportion (297.21 m2/g); likewise, it was the carbon that eliminated the highest ibuprofen quantity. The maximum amount of ibuprofen adsorbed by CA1:2 and CA1:3 were 68.27 mg/g and 65.75 mg/g, respectively. Results suggest that the charcoals activated from cocoa husk are considered as good adsorbents of ibuprofen, collaborating in the reduction of this pollutant in the aqueous phase, contributing to environmental sanitation.