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

Electrokinetic remediation study for cadmium contaminated soil

This paper presents the results of an experimental research undertaken to evaluate different purging solutions to enhance the removal of cadmium from spiked contaminated field soil by electrokinetic remediation. Three experiments were conducted when soil was saturated with deionised water and subsequently deionised water, ammonium citrate and sodium citrate were used as purging solutions at anode end. One experiment was conducted when the soil was saturated with ammonium citrate and itself was used as the purging solution. Results showed that 49% reduction of cadmium concentration was achieved in the case of soil saturated [washed] with ammonium citrate as well as purging solution also was ammonium citrate. The soil pH and washing solutions were the most important factors in controlling the removal of cadmium in electrokinetic remediation process