Adsorption characteristics of methylene blue by peanut husk in batch and column modes

This study described adsorption of methylene blue (MB) by peanut husk in batch and fixed-bed column modes at 293 K. The kinetic and equilibrium of adsorption in batch mode were studied. Nonlinear regressive method was used to obtain relative parameters of adsorption models. The kinetic process was better described by a pseudo-second-order kinetic model. The equilibrium adsorption was effectively described by Temkin adsorption isotherm. The value of q(m) from the Langmuir model was 72.13 +/- 3.03 mg g(-1) and the diffusion coefficient value was in the order of 10(-8) CM2 s(-1). In fixed-bed column adsorption, the effects of bed height, feed flow rate, and inlet MB concentration were studied by assessing breakthrough curve. The column data were fitted by the Thomas, Clark and modified dose-response models. The modified dose-response model was best to fit the breakthrough curves at experimental conditions. FITR analysis showed that there were carbonyl and hydroxyl groups on the surface of the adsorbent. The results were implied that peanut husk may be suitable as an adsorbent material for adsorption of MB from an aqueous solution. (C) 2010 Elsevier B.V. All rights reserved.