Studies on the Preparation Characterization and the Adsorption Behaviour of Activated Charcoal originated from Agricultural waste Products

Abstract

Activated charcoal is a form of carbon compound having large surface area and vivid porous structure. Commercially activated carbon is obtained from animal, wood and organic based materials such as coal etc. Despite of its use as efficient adsorbent, the higher cost of commercial activated charcoal restricts its large scale use in different fields. This has lead to the use of agricultural waste products as the raw materials for the production of cost effective and eco friendly activated carbon and their applications in the adsorption of toxic species. newlineThe present study involves preparation and characterization of activated carbon from agricultural waste materials, namely, Areca (Areca catechu) Husk, Pepper (Piper nigrum) Peduncle and Coconut (Cocos nucifera) leaf. The activated carbons were obtained by three methods, namely, physical, chemical and microwave activation and were characterized by XRD, SEM, FTIR and TGA techniques. These activated carbons were used for the adsorption of Methylene blue, a cationic dye and Maleic acid. Adsorption studies were carried out as a function of initial concentration, contact time and temperature. By using the adsorption data, adsorption isotherm, kinetics and thermodynamics of adsorption were studied. newline(xx) newlineAll the activated carbons prepared were polycrystalline in nature as observed from XRD studies. The surface morphology of prepared activated carbons were studied before and after the adsorption process. Various functional groups such as, C=O, C=C, C-H etc., present on the surface interact with the adsorbate molecule by electrostatic and and#960;-interaction, which facilitates the adsorption process. newlineAdsorption of Methylene blue and Maleic acid on the surface of prepared activated carbons were analyzed by Freundlich, Langmuir and BET models and were found to follow the second order kinetics. The adsorption process was endothermic and spontaneous in all the cases. Among all the prepared activated carbons, physically activated Pepper Peduncle carbon showed highest adsorption capacity