摘要
The study results of the effects of temperature and ionic strength on the adsorption kinetics of Pb^2+ and Cu^2+ by latosol,red soil and kaolinte coated with Mn oxide showed that Pb^2+ and Cu^2+ adsorption by all samples.as a whole,increased with raising temperature.Temperature also increased both values of Xm(the amount of ion adsorbed at equilibrium)and k(kinetics constant)of Pb^2+ and Cu^2+,The activation energies of Pb^2+ adsorption were kaolin-Mn>redsoil>goethite and those of Cu2+ were latosol>redsoil>kaolin-Mn>goethite,For a given single sample the activation energy of Cu^2+ was greater than that of Pb^2+.Raising ionic strength decreased the adsorption of Pb^2+ and Cu^2+ by latosol,red soil and kaolinite coated with Mn oxide but increased Pb^2+ and Cu^2+ adsorption by goethite.The contrary results could be explained by the different changes in ion forms of Pb^2+or Cu^2+ and in surface charge characteristics of latosol,red soil,kaolin-Mn and goethite,Increasiung supporting electrolyte concentration increased Xm and k in goethite systems but decreased Xm and k in kaolin-Mn systems.All the time-dependent data fitted the surface second-order equation very well.
The study results of the effects of
temperature and ionic strength on the adsorption kineties of Pb￣2+ and Cu￣2+ bylatosol, red
soil and kaolinte coated with Mn oxide showed that Pb￣2+ and Cu￣2+ adsorption by all
samples, as awhole, increased with missing temperature. Temperature also increased both
values of X_m (the amount of ionadsorbed at equilibrium) and k (kinetica constant) of Pb￣2+
and Cu￣2+. The activation energies of Pb￣2+ adsorption werekaolin-Mn >red soil>goethite
and those of Cu￣2+ were latosol> red soil > kaolin-Mn >goethite. For a given singlesample the
activation energy of Cu￣2+ was greater than that of Pb￣2+. Raising ionic strength decreased
the adsorptionof Pb￣2+ and Cu￣2+ by latosol, red soil and kaolinite coated with Mn oxide but
increased Pb￣2+ and Cu￣2+ adsorption bygoethite. The contrary results could be explained
by the different changes in ion forms of Pb￣2+ or Cu￣2+ and in surfacecbarge characteristics
of latosol, red soil, kaolin-Mn and goethite. Increasing supporting electrolyte concentration
in-creased X_m and k in goethite systems but decreased X_m and k in kaolin-Mn systems. All
the time-dependent data fit-ted the surface second-order equation very well.
