عنوان مقاله [English]
In current study kaolin-Zein composite was prepared and its performance was investigated via methylene blue adsorption. For preparation of mentioned adsorbent, kaolin were coated using Zein as natural polymer via solution blending method. The kaolin-Zein composite was characterized by Fourier transform infrared (FTIR) spectroscopy, Zeta potential and particle size analysis. The obtained results confirmed kaolin coating with Zein. The effect of pH on adsorption capacity showed, the adsorption capacity increased when pH increased. Adsorption yield verses time was determined at different adsorbent dosage. The results demonstrated that adsorption process reached equilibrium at the optimal modified adsorbent dosage of 0.6 g/l and pH of 9 after 60 min. The adsorption yield of kaolin composite was improved about 30% when compared with that one of pure kaolin at the same operating condition (temperature, pH, adsorbent dosage and contact time). Adsorption capacity values were appropriately fitted to Freundlich, Langmuir isotherms and pseudo second order equation as governing kinetic model. Moreover, maximum adsorption capacity of 135 mg of methylene blue per g of kaolin-Zein was obtained.