Inhibition of Aqueous Copper and Lead Adsorption onto Goethite by Dissolved Carbonate Species

Adsorption of aqueous copper and lead by goethite is inhibited by copper and lead carbonato complexing, which becomes important at pH’s greater than the range 6.5 to 7 at a total dissolved carbonate (CT concentration of 0.01 w, and total metal concentrations of 0.1 to 0.01 mM. This reflects the relatively weak adsorption by goethite of neutral and anionic metal carbonato complexes in contrast to strong adsorption of free ions and/or cationic copper and lead hydroxo complexes. This study indicates that the mobilities of copper and lead in soil and ground-water systems are a function of the pH and CT content of those systems.