Isotherm and Kinetics Study of Biosorption of Cationic Dye onto Banana Peel

Today there are a lot of dyes available commercially. They are used in many industries such as food, paper, carpet, rubber, plastics, cosmetics and textiles. Its can be classified as follows: anionic (direct, acid and reactive dyes), cationic (basic dyes) and non-ionic (dispersive dyes). Removal of a basic dye, methylene blue, from an aqueous solution was studied by biosorption on banana and orange Peels waste. The biosorbent was chemically modified. To mentioned functional groups in order to determine their contribution to the adsorption of dyes. Fourier transform infrared (FTIR) was investigated. Kinetic study is also carried out to observe the effects of various process parameters. The maximum values of adsorption capacities for activated banana peel (ABP) was 19,671mg/g and 18,647mg/g for natural banana peel (NBP) at pH 4-8, 20 degrees C. The results follow kinetic of pseudo second-order rate equation. The suitability of the adsorbent was tested by fitting the adsorption data with four isotherms, namely Freundlich, Langmuir and Temkin. The characteristic parameters for each isotherm have been determined. The Freundlich equation represented the best fit of experimental data for activated banana peel (ABP) than the other isotherm equations, and Langmuir equation described the adsorption of natural biosorbent (NBP). It was observed that activated banana peel was a suitable adsorbent than other for removal of methylene blue from aqueous solutions. (C) 2012 Published by Elsevier Ltd. Selection and/or peer review under responsibility of The MEDGREEN Society.