Comparison of sorption capacity and surface area of activated carbon prepared from Jatropha curcas fruit pericarp and seed coat

Activated carbons were prepared from fruit pericarp and seed coat of Jatropha curcas using KOH and NaCl as activating agents leading to the production of four samples of activated carbons JPS, JPP, JCS and JCP. The adsorption capacity based on adsorption of methylene blue was determined for each sample. A further study of adsorptive properties of the most efficient activated carbon (JPS) was made by contacting it with standard solutions of methylene blue, acetic acid and potassium permanganate. The effects of mass of active carbon used, initial concentration of the solute and the pH of the solution on adsorption performance were investigated. Ash content and percentage fixed carbon were determined for two of the activated carbons (JPS and JCS) with the highest adsorptive capacity. Equilibrium study on adsorption was carried out and the adsorption data were analyzed using the Langmuir isotherm. The results obtained indicate that activated carbons from the fruit pericarp and the seed coat of J. curcas can be used as high performance adsorbents with the fruit pericarp activated carbon showing the higher adsorption capacity. The adsorption data fitted well to the Langmuir model and adsorptive area of 824–910 m2/g was obtained for the activated carbon. KEY WORDS: Carbonization, Adsorption, Adsorbent, Activated carbon, Jatropha curcas, Fruit pericarp, Seed coat, Chemical activation Bull. Chem. Soc. Ethiop. 2012, 26(2), 171-180. DOI: http://dx.doi.org/10.4314/bcse.v26i2.2