Adsorption of Malachite Green Dye Using Orange Peel

High level of dyes production and their widespread use in many applications generate colours wastewaters which cause severe water pollution. The pollutant contributes to high suspended solids (SS), chemical oxygen demands (COD), biochemical oxygen demands (BOD), heat, colour, acidity, basicity and other soluble substances. The presence of these dyes in aquatic systems poses heavy risks to human health. Therefore, removal of such dyes from water bodies may be considered an interesting and important research activity. This study shows that orange peel can be used as a suitable adsorbent for the removal of malachite green dyes from solutions. This is a work on the removal of Malachite green dye from their solution with the use of orange peel. The orange peelis sourced locally. Proximate analysis done on the adsorbent revealed that the orange peels had 13.25% Moisture content, 5.68% Ash content and 4.7% Carbon content. FTIR technique was also used to identify the functional groups and organic compounds inherent in the orange peels. The adsorption isotherm models used were Henry, Langmuir I, Langmuir II, Langmuir III, Langmuir IV, Freundlich, Temkin and Dubinin-Radushkevich. The result from the models shows that Henry isotherm model fits better for the adsorption of the dye with Orange peels. Results obtained showed that adsorption followed second order kinetics. Thermodynamic data for enthalpy (ΔH) for the adsorption of the dye shows that adsorption was endothermic. The entropy result indicates that there is an increase in randomness at the solid liquid interface. Free energy change shows that adsorption for the dye at temperatures of 298, 323, 343 and 373 were spontaneous and feasible