Decolorization of acidic dye by charcoal from coffee grounds

Abstract

From the viewpoints of decreasing environmental burdens and recycling of materials, the adsorption ability of charcoal from coffee grounds for acidic dye (acid orange 7) removal was investigated by the batch method. Differences in the removal ratio and removal rate of acid orange 7 could be explained by differences in the properties of charcoal such as specific surface area and pore volume. In the relationship between the amount of acid orange 7 adsorbed at each elapsed time and the square root of elapsed time, a good linearity was recognized. Since the good linearity between the acid orange 7 adsorption and the square root of elapsed time was recognized, the intraparticle diffusion of acid orange 7 onto pores of adsorbents was identified as the rate-limiting step in the adsorption process.