ÁLVAREZ, S.; GARCÍA, R.; RODRIGUEZ, A.; GARCÍA, J.
Chemical Engineering Transactions 43 (2015) 1963-1968.
The objective of this work was to evaluate the efficiency of a synthesized activated carbon for the removal of methylene blue from aqueous solution. Activated carbons synthesized from lignocellulosic precursors are an interesting alternative for their use as adsorbents and catalyst supports in the wastewater treatment field. In this work a micro-mesoporous activated carbon was synthesized from peach stones by chemical activation. The textural, morphological and chemical characterization of the material was carried out, revealing the acidic nature of the solid. Adsorption isotherms were conducted at several solution temperatures, obtaining the largest methylene blue adsorption capacity value, 444.3 mg.g-1, at the highest temperature, 333 ºC. The equilibrium adsorption data were tested by four isotherm models, i.e. Langmuir, Freundlich, Tóth and Redlich- Peterson, finding that the models best fitting the experimental adsorption data were Tóth and Redlich- Peterson equations. The calculated thermodynamic parameters suggested that an endothermic and spontaneous adsorption process is occurring.