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 samp...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.展开更多
文摘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.
