Ethylparaben removal using chitin carbons derived from Hermetia illucens pupa casings

The study developed activated carbons with a highly developed specific surface area, showing excellent adsorption properties for aqueous ethylparaben solutions and suitability for reuse. Empty pupal casings of Hermetia illucens served as precursors. Using a two-step process-microwave carbonization and activation with potassium carbonate-carbons with surface areas of 1200-2302 m2/g were produced. The resulting materials featured a highly developed pore structure, combining micropores and mesopores, ideal for adsorbing organic molecules. Adsorption kinetics and isotherms were analyzed using statistical physical models. The activated carbons exhibited a maximum adsorption capacity of 739 mg/g, demonstrating chemisorption behavior aligned with linear and non-linear pseudo-second-order kinetics and the linear Langmuir isotherm. The adsorption mechanism involved it-it interactions, hydrogen bonding, and electrostatic forces between ethylparaben molecules and the adsorbent surface. The process was endothermic and spontaneous under the tested conditions. The carbons retained high reusability, achieving 84 % desorption efficiency after three cycles. This research highlights the potential of waste-derived activated carbons for efficient and sustainable adsorption applications.