Use of murici (Byrsonima crassifolia) and jabuticaba (Plinia cauliflora) residues in the preparation of porous materials: Effect of pH on the adsorption efficiency of the contaminants phenol, diethylphthalate and amoxicillin

Abstract

Activated charcoals with the chemical activator (H3PO4) were synthesized from agro-industrial residues, Murici seeds (CA-MU) and Jabuticaba (CA-JA). The synthesized charcoals were characterized by thermogravimetric analysis (TG), N2 adsorption and desorption isotherms, Fourier transform infrared spectroscopy (FTIR), point of zero charge (pHPZC) and scanning electron microscopy (SEM). The charcoals produced presented mesoporous characteristics, surface areas of 884.226 m2.g−1 for CA-JA and 556.97 m2.g−1 for CA-MU, mean pore diameters suitable for adsorption of phenol (PHE), diethylphthalate (DEP) and amoxicillin (AMX). The chemical characterization indicated the acid profile of the surface of the charcoals, which presented pHPZC of 6.3 (CA-JA) and 6.7 (CA-MU). The adsorption studies, in aqueous solution of the pollutants (PHE), (DEP) and (AMX), indicated that the removal capacity is strongly influenced by the pH of the solution. Toxicity tests demonstrated that the adsorption process was responsible for decreasing the toxicity of the pollutants studied. Thus, given the results presented, the activated charcoals synthesized can be considered high potential adsorbents for applications in the removal of organic pollutants in aqueous solutions.