Chemical-activated carbon from coconut (Cocos nucifera) endocarp waste and its application in the adsorption of ß-lactoglobulin protein

The aim of this work was to study the use of coconut endocarp, a residue widely generates by the agroindustry, as a precursor in the synthesis of activated carbon. The material obtained was applied as adsorbent for whey protein purification, using ß-lactoglobulin as the model molecule. The coconut endocarp was initially subjected to leaching in alkaline medium. The activated carbon (AC) was prepared by the chemical activated method using ZnCl2 as activating agent. The yield of the synthesis process and the physical and chemical properties of the carbon were determined. In addition, the effects of various factors such as the pH, the carbon mass, the time, and temperature on the adsorption performance was investigated. The activated carbon showed a pore size distribution in the mesoporous range and high surface area. The adsorption tests evidenced that the AC had the best performance at pH 3.0. The pseudo second-order kinetics model set better to the experimental data of β-lg adsorption onto AC and Langmuir model was more appropriate to represent the experimental data, with maximum adsorption capacity of 524.76 mg/g, evidencing the potential of the coconut endocarp waste for production of activated carbon for the purification of whey proteins.

Keywords: agro-industrial waste, alkaline leaching, activated carbon, adsorption of b-lactoglobulin.