Springer Online Journal Archives 1860-2000
Abstract Experimental data for sorption of Hg, Cd, Cu, and Pb by sand, silt, and organic-rich sediments from the Ottawa River, Canada show significant conformity to Langmuir's equation. Values of the bonding energy constant and the sorption maximum correlate directly with organic content and mean grain size (φ). Desorption experiments indicate that the heavy metals form stable complexes in nitrilotriacetate (NTA) and NaCl Solutions, with the following desorption ratios: Hg, 1:1 (Cl−:NTA); Pb, 1:10; Cd, 1:2. Serial and batch desorption studies under various conditions show that the cation-exchange order in the sediments is Hg〉Pb〉Cu〉Cd. For a given heavy metal the partition coefficient between sediment and solution is not greatly changed by the presence of another cation, provided the latter has the same order of concentration. If, the concentration of one cation exceeds another by more than 10, however, significant desorption of the less concentrated ion takes place on a mass action basis.
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