Removal of Cr(VI) from Aqueous Solution Using Activated Carbon Prepared from Several Agriculture By-Products
The adsorption characteristics of Cr(VI) on activated carbon prepared from several agriculture by-products via sulphuric acid-treatment were compared and the best concentration of sulphuric acid for carbonization were evaluated. It is confirmed that peanut shell is best material for the absorption of Cr(VI) ion from aqueous solution among hybrid giant napier straw, rice husk and commercial activated carbon in this study. The effects of agitation time, solution pH, temperature and Cr(VI) initial concentration on Cr(VI) adsorption were investigated. The 3:1 volume ratio of sulphuric acid : deionized water is the optimal concentration for Cr(VI) biosorption for peanut shell carbonization. Cr(VI) adsorption is highly dependent on solution pH. Initial solution pH =1.5 was the most favorable pH for Cr(VI) removal. Cr(VI) biosorption increases with increasing initial concentration, agitation time and solution temperature. The adsorption kinetics is found well fitted to the pseudo-second-order kinetic model. The adsorption equilibrium data are best represented by Langmuir model.The maximum adsorption capacity of carbonized peanut shell for Cr(VI) reached 26.22 mg/g.