Авторы: HIGGINS C., DZOMBAK D.

2006 г.

Soil and Sedim.

     The sorption of free cyanide (HCN) on mineral components of sediment, activated carbon, and a freshwater sediment was studied via batch experiments in synthetic freshwater at pH 6.4–7.6. It was found that free cyanide did not sorb to any significant extent on sediment mineral components, but did sorb strongly to activated carbon and moderately to a freshwater sediment. Results of experiments with 100 and 150 μg/L free cyanide spike amounts resulted in no observed sorption to kaolin clay, Ottawa sand, or alumina in the synthetic freshwater. Extensive removal of free cyanide from the aqueous phase was observed in the partitioning experiments with the powdered activated carbon. Results with whole sediment indicated up to 46% removal of free cyanide from the aqueous phase in experiments with 20 and 50 μg/L free cyanide. The organic-carbon-normalized distribution coefficient Koc (= Cs/Cw foc) for free cyanide sorption on the activated carbon (foc = 1.0), 4.2 L/gs , was similar to the Koc value for free cyanide sorption on the freshwater sediment (foc = 0.0031), approximately 12.9 L/gs . The results indicate that free cyanide can sorb to sediments with organic carbon content under freshwater conditions, primarily through interaction of HCN with organic carbon in the sediment.

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