Movement of Chloride in a Soil with Variable Charge Properties: II. Sanitary Landfill Leachate1
- K. Y. Chan,
- H. R. Geering and
- B. G. Davey2
The movement of a lime-treated sanitary landfill leachate (pH 10.3) through a column filled with the subsoil of a xanthic ferralsol was studied in the laboratory. Chloride movement in the leachate-treated column deviated from the miscible displacement equation derived by Nielsen and Biggar because the amount of positive charge carried by the soil changed with the pH and ionic strength. The leachate was shown to contain carboxylate groups as well as Cl and competition between these anions for the positively charged sites on the oxidic surfaces was observed. When distilled water was applied to the column at the end of the leachate treatment, Cl was displaced as the ionic strength of the column decreased, even though pH remained >9. A net desorption of Cl of 0.69 meq/100 g was observed. Chloride cannot be treated as an indifferent anion in modeling the movement of salt solutions through oxidic soils with variable charge properties.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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