Separation of lead ions from aqueous solutions by adsorption at talc surface

Abstract

Separation of lead ions from aqueous solutions containing 5, 10, 20, 50, 100, 200 and 500 ppm lead was studied by adsorption at the surface of talc mineral of Indian origin. The effect of temperature (20, 30, 40, 50, 60, 70^oC) on adsorption phenomena was studied and the data was analyzed using Langmuir isotherm. The changes in enthalpy (<i style=""><img src='/image/spc_char/delta.gif'>H</i>)<i style="">,</i> free energy (<i style=""><img src='/image/spc_char/delta.gif'>G)</i> and entropy (<i style=""><img src='/image/spc_char/delta.gif'>S)</i> were evaluated. The negative values of <i style=""><img src='/image/spc_char/delta.gif'>G</i> and <i style=""><img src='/image/spc_char/delta.gif'>H</i> indicate the adsorption of lead ions on talc surface to be spontaneous and exothermic under the experimental conditions.