Harnessing microwave energy to transform Nephelium lappaceum L. peel into activated carbon for chloramphenicol eradication in aqueous solutions

Abstract

Emerging contaminants (EC) like chloramphenicol in wastewater are highly related to human, livestock, and aquaculture therapeutic activities. High levels of chloramphenicol in water may cause toxic effects on an aquatic environment, humans, and animals. The removal of chloramphenicol in wastewater was the main objective of this study. This study explores the use of microwave irradiation in the production of Rambutan peel-based activated carbon (RPAC) at a heating power of 700 W for 15 min under carbon dioxide, CO2 gas flow. RPAC had a BET surface area of 583.44 m2/g, mesopores surface area of 469.87 m2/g, total pore volume of 0.27 cm3/g, and average pore diameter of 2.31 nm. The equilibrium study shows that the concentration of Cp adsorbed by RPAC increased as the initial concentration increased from 4.93 mg/g to 25.10 mg/g. Isotherm adsorption determined that Langmuir was the preferred model since it has the lowest RSME and highest R2 of 3.34 and 0.9994, respectively. It was observed from kinetic studies that the adsorption system relies on the pseudo-second order. According to thermodynamic studies, the enthalpy change, △H° and Gibbs free energy, △G° obtained indicating that the adsorption process occurs in an exothermic and spontaneous state.