Removal of Crystal Violet from Aqueous Solution by Adsorption onto Eggshells: Equilibrium, Kinetics, Thermodynamics and Artificial Neural Network Modeling

Abstract

The feasibility of utilizing eggshells as a potential low-cost adsorbent for removal of hazardous Crystal violet dye from aqueous solution was investigated. Employing a batch experimental set-up, the effect of operational parameters such as adsorbent dose, initial solution pH, initial dye concentration and temperature on the dye removal process was studied. The optimum conditions for decolorization of the dye solution were: initial dye concentration = 50 mg L−1, pH = 8.0 and adsorbent dose = 30 g L-1. The temperature had a significant impact on the adsorption process. The adsorption process followed pseudo second-order kinetics while the adsorption equilibrium data well fitted to the Langmuir isotherm model. Activation energy of the adsorption process (Ea) was calculated as 55.94 kJ mol−1 by using the Arrhenius equation, indicating chemisorption nature of adsorption of Crystal violet onto eggshells. A thermodynamic study showed spontaneous and exothermic nature of the adsorption process. An artificial neural network (ANN) model was developed to predict the dye removal performance of eggshells. The ANN model provided reasonable predictive performance. It was concluded that simulations based on the developed ANN model can estimate the behavior of the adsorption process under different experimental conditions.