Conversion of grape industrial processing waste to activated carbon sorbent and its performance in cationic and anionic dyes adsorption

Grape processing industry waste was used as a novel precursor for the production of a low-cost activated carbon with zinc chloride chemical activation. The effects of the production variables, such as impregnation ratio, activation temperature and activation time on the some textural properties were investigated. The optimal activated carbon which had the highest surface area and pore volume was obtained by these conditions as follows: 6:1 impregnation ratio, 600 degrees C activation temperature and 60 min activation time. The optimum conditions resulted in an activated carbon with a carbon content of 81.76% and a yield of 44.13%, while the surface area of 1455 m(2)/g, with the total pore volume of 2.318 cm(3)/g, mesoporosity of 94.61% and average pore diameter of 6.81 nm. These results showed that the grape wastes seemed to be an alternative precursor for the commercial activated carbon productions. The adsorptive property was tested using Methylene blue and Metanil yellow dyes. The adsorption behaviors for both dyes were well described by the Langmuir isotherm model, showing a monolayer adsorption capacity of 417 mg/g and 386 mg/g for Methylene blue and Metanil yellow, respectively. This study demonstrated that produced optimal activated carbon could be employed as an efficient cleaner to compare with the commercial ones for the removal cationic and anionic dyes from wastewater. (C) 2015 Elsevier Ltd. All rights reserved.