Main Article Content
Sappanwood is natural dye containing pigment named brazilin. Brazilin can be oxidized to brazilein yielding red color. Generally, brazilein extract or pure brazilein are used in textile and cosmetics industry. Using adsorption method, brazilein extract can be transformed to lake pigment which can be applied in many more applications. In this study, the adsorption of brazilein on monmorillonite and its adsorption mechanisms were investigated. The effect of pH, the amount of adsorbents and the concentration of brazilein solutions on the adsorption as well as the adsorption kinetics and adsorption isotherm were explored. It was found that high adsorption percentage can be obtained at pH 5-7. The lower adsorption capacity of montmorillonite at equilibrium was observed when the higher amount of the adsorbent was used. Moreover, the adsorption capacity of montmorillonite at equilibrium was increased with the increase of the concentration of brazilein. In addition, adsorption kinetics and adsorption isotherm were fitted well with a pseudo-second order kinetics model and Langmuir adsorption isotherm, respectively.
Keywords: montmorillonite; brazilein; adsorption kinetic; adsorption isotherm
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