ABSTRACT
R ln(a2/ a I )pH,J,c,ds ads Me-l/T2-1/Ti (18)
where I is the ionic strength, cads is the concentration of adsorbed cations, and a1 and a2 are their equilibrium activities (concentrations were used in Ref. 63) in solution at temperatures T1 and T2• The pH and ionic strength are independent variables and they can be directly controlled, and Cads is controlled indirectly, n'amely it is a function of the initial concentration of heavy metal cations. When adsorption isotherms for T1 and T2 are available, a1 and a2 corresponding to given Cads can be obtained by inter-or extrapolation.
