A Novel Approach to Investigate Adsorption of Crystal Violet from Aqueous Solutions Using Peels of Annona squamosa

An effective and economical adsorbent was prepared from the peels of Annonasquamosafor theremoval of crystal violet from aqueous solutions. Adsorption studies were carried out using batch experiments.The dependence of initial dye concentration, pH, contact time, particle size and temperature on the adsorptionprocess was studied. The crystal violet was found to be electroactive and hence electrochemical studies werealso performed. The study showed that the equilibrium was achieved within 60 min for the different initialconcentrations (10 to 30 mg.l ). The equilibrium adsorption data were analyzed 1 using various isotherm modelsand they were found to fit Langmuir, Freundlich, Temkin and Harkins-Jura isotherm models in varying ordersof magnitude. The maximum dye adsorption capacitiesfor cyclic voltammetry and spectral studiesat 303 K werefound to be 5.6818 × 10 4 A.g 1(in terms of current)and 5×104 mg.g 1(in terms of weight),respectively. The datasuggested that the adsorption kinetics was best represented by pseudo-second order kinetic model.The thermodynamic parameters including G, H and S for the adsorption process have also been evaluatedusing which it was concluded that the process of adsorption was spontaneous and endothermic. The cyclicvoltammetricand spectral studies yielded similar results. Furthermore, statistical analysis also showed theabsence of any significant difference between the two methods.