Adsorption of Basic Dye From Aqueous Solution Using Mixture of Agricultural Solid Wastes (Maw): Isotherm, Kinetic Studies and Process Design

Abstract

The aim of this study is to evaluate the adsorption capability of mixture of agricultural solid wastes, which is a mixture of agricultural solid wastes (Empty coconut bunch, banana stalk, coconut frond, oil palm frond and bamboo leaf). Low doses of these rejected wastes (0.1 g each) mixed together to be used as adsorbent in order to investigate its ability for methylene blue dye (MB) removal. Batch adsorption system was studied at 30 °C with respect to the initial dye concentration (50 - 300 mg/L), contact time and pH of solution (2-10). The maximum removal was obtained at pH 8. The equilibrium data were analyzed using the Langmuir (3 forms), Freundlich and Temkin isotherm models. The adsorption isotherm followed the order Langmuir form 1> Freundlich isotherm > Temkin isotherm > Langmuir form 2> Langmuir form 3. The adsorption isotherm data were fitted well to form 1 of Langmuir isotherm and the adsorption capacity was found to be 93.458 mg/g. The adsorption kinetic was well described by the pseudo-second-order model. The intraparticle diffusion was not the only rate controlling step of adsorption process. Single stage batch adsorber was designed using Langmuir isotherm to predict the minimum amount of adsorbent need to achieve a specific percentage of dye removal. The adsorption capacity obtained for the adsorption of MB onto MAW was good compare with other reported values.