Effect of temperature on single and competitive adsorptions of Cu(II) and Zn(II) onto natural clays.

摘要: This study conducted a combined adsorption-sequential extractionanalysis (CASA), by which five phases (i.e., exchangeable, carbonate, Mn-Oxide, organic, and Fe-Oxide phases) of adsorbed heavy metals were analyzed, to investigate temperature effects on single competitive adsorptions Zn(II) Cu(II) ontonatural clays. In the case adsorption Zn, exchangeable phase decreased from 65 40%, but thecarbonate increased 30 with an increase in 15 55 °C. However, itscompetitive Cu, Zn was mostly present (over 90%), temperature, only 10%. over 50% among total amount carbonate both cases ofsingle adsorptions. The phaseadsorption Cu 56 61% 60 66% adsorptions, respectively, atemperature increase. These results show that Zn,the major mechanism retention natural clay soils might beexchangeable adsorption, especially Cu. be is known more immobile than adsorption. It seems onto clays endothermic reaction, represents thatthe equilibrium constants capacities increase, exception exchangeablephase