Sorptive Removal of Crystal Violet from Aqueous Solution Using Spent Tea Leaves: Part I Optimization of Sorption Conditions and Kinetic Studies

The low cost adsorbent, spent tea leaves (STL) has been tested for the effectiveness in decolorization of wastewater containing crystal violet dye in batch experiments. Effect of various parameters such as agitation time, pH, temperature and adsorbent dose has been investigated. The dye uptake has been found to increase with pH and temperature. The kinetic uptake data, obtained at different sorbate concentrations, is best interpreted by pseudo second order model and rate constants for adsorption are found to be 8.5 × 10–3, 22.2 × 10–3 and 42.0 × 10–3 g mg–1 min–1 for initial dye concentrations of 10, 20 and 30 mg L–1 respectively. The dye uptake was found to increase with temperature and the activation energy for adsorption process was found to be 10.45 ± 0.89 kJ mol–1.