Özet:

Kinetics, thermodynamics and isotherm studies of malachite green (MG) adsorption by orange peel (OP) modified with ethanol, calcium chloride and sodium hydroxide were performed. Effects of initial dye concentration, temperature and pH on the adsorption were studied at the different contact times. The amounts of MG adsorbed onto OP increased with increasing contact time, initial dye concentration, solution temperature, and pH. Maximum dye adsorption was about 92.90% under all the experimental conditions. Percent desorption of MG from the surface of OP was lower in the alkali and HCl solutions and higher in an acetone-water mixture of 50%. Adsorption kinetics was best fit the pseudo-second order model with correlation coefficients of 0.99 and 1 for the concentrations studied. Thermodynamic results indicated a spontaneous adsorption. Adsorption isotherm obeyed the Langmuir model. The Langmuir adsorption capacity was determined as 14.55 mg g-1. FT-IR and SEM analyses were also recorded before and after the adsorption. 

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