Removal of Copper from Aqueous Solution using Tunisian Clay

Abstract

Natural adsorbents such as clay was used to replace expensive imported synthetic adsorbents. In this study, Scanning Electron Microscopy (SEM), Infrared spectroscopy and X-ray diffraction techniques were used to characterize the used sorbent (clays C). Batch experiments were performed to evaluate the effects of contact time, solution pH and temperature on copper removal onto used sorbent from aqueous solution. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models to calculate isotherm constants. Kinetic studies showed that an equilibrium time of 1 h was required for the adsorption of Cu(II) onto Tunisian clay. Equilibrium adsorption is affected by the initial pH of the solution. The maximum adsorption capacity was obtained at pH 5. Adsorption tests in synthetic wastewater revealed that the adsorption data of this material for copper ions were better fit to the Langmuir isotherm based on correlation coefficients. The influence of temperature on the adsorption process was also evaluated. Results indicated that adsorption of Cu(II) on the sorbents is endothermic. The thermodynamic parameters (ΔG°,ΔH° and ΔS°) for Cu(II) sorption were also determined from the temperature dependence. Results of this study suggest that used Tunisian clay may be a promising adsorbents for environmental remediation.