Kinetics and Isotherm Studies of Crystal Violet Adsorption from Aqueous Solution using Tomato Seeds

In this work, the feasibility of employing tomato seeds to remove crystal violet a cationic dye from its aqueous solutions was investigated. Parameters that influence the adsorption process such as particle size, pH, adsorbent dose, initial dye concentration, contact time and temperature were studied in batch experiments. The optimum conditions for removal of CV were found to be pH 1.48, equilibrium time 60 min, biosorbent dosage 1.4 g, initial dye concentration 4.4 mg L1 and temperature 312K. The experimental equilibrium adsorption data fitted well to the Freundlich isotherm model. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic parameters such as Gibbs free energy (G0), enthalpy (H0), and entropy (S0) were also calculated and it was found that the adsorption of dye by tomato seeds was a spontaneous process. It was concluded that tomato seeds have the potential for application as an adsorbent for removal of crystal violet from aqueous solution.