SORPTION AND DESORPTION STUDIES OF METALLIC ZINC ON AN ALLUVIAL SOIL

The sorption of metallic zinc from the pH-adjusted aqueous solution at varying initial concentrations onto a clay soil through batch equilibrium experiments has been studied. The pH of the initial concentrations ranging between 50 mg/L to 250 mg/L has been varied from 3 to 7. The sorption data fitted very well with both Langmuir and Freundlich isotherm models and Freundlich model gave higher correlation coefficients. The maximum sorption of metallic zinc occurred at pH=6. The pseudo-second order kinetics model was most agreeable with the experimental sorption data, whereas the pseudo-first order model was found to be insufficient. A nonionic surfactant was tested for its desorption potential and was found to be fairly effective at 2% concentration with removal of more than 60% sorbed Zinc.