Abstract
In order to provide a sound experimental background for the remediation of metal-contaminated soil by chelators, the desorption/complexation/dissolution characteristics of Cd from kaolin as a representative soil component by four chelators (NTA, EDTA, EGTA and DCyTA) have been investigated as a function of solution pH. For all chelating agents under examination, the ratio of Cd (desorbed from kaolin) to chelator was found to be 1:1. The chelation/dissolution of Cd was strongly dependent on the solution pH for NTA and EDTA. In the NTA system, 100% Cd dissolution occurred only at a pH = 8 and pH < 3.2; under weakly acidic conditions only 45% of the Cd on kaolin was dissolved due to readsorption of CdNTA- complex on kaolin. At a pH ≥ 10, Cd dissolution decreased, due to Cd hydroxide precipitation. Only 85% of the total Cd on kaolin desorbed under weakly acidic conditions in the EDTA system, indicating metal complex readsorption similar to that found in the Cd-NTA system. Zeta potential measurements showed that the surface charge of Cd-loaded kaolin became more negative after addition of EDTA and NTA with a shift in the pH at the point of zero charge to a lower value. As compared to the EDTA and NTA systems, DCyTA and EGTA complexed strongly with Cd (100% Cd dissolution) over a wide pH range (2.5–12.0). The zeta potential of kaolin did not change and no Cd readsorption was found after addition of EGTA and DCyTA. The capacity of the four chelators for removing Cd from kaolin was found to be in the order DCyTA > EGTA > EDTA > NTA.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Acar, Y. B., Gale, R. J., Putnum, G. A., Hamed, J., and Wong, R.: 1990, J. Environ. Sci. Health 25(6), 687.
Alder, A. C., Siegrist, H., Gujer, W., and Giger, W.: 1990. Water Res. 24(6), 733.
Allen, H. E., and Boonlayangoor, C.: 1978. Verh. int. Verein. Limnol. 20, 1956.
Assink, J. W.: 1986, Extractive methods for soil decontamination: A general survey and review of operational treatment installations, in Assink, J. K., and Van den Brink, W. J. (eds.), Contaminated Soil, Martinus Nijhoff, Dordrecht, Holland, pp. 655–667.
Banat, K., Förstner, U., and Müller, G.: 1974, Chem. Geo. 14, 199.
Borggaard, O. K.: 1981, J. Soil Sci. 32, 727.
Brown, G. A. and Elliott, H. A.: 1992, Water, Air, and Soil Pollut. 62, 157.
Brown, M. J., and Lester, J. N.: 1979, Water Res. 13, 817.
Cabrera-Guzman, D., Swartzbaugh, J. T., and Weisman, A. W.: 1990, J. Air Waste Manage. Assoc. 40, 1670.
Chang, H. C., and Matijevic, E.: 1983, J. Colloid Interface Sci. 92, 479.
Chau, Y. K., and Shiomi, M. T.: 1972, Water, Air, and Soil Pollut. 1, 149.
Chubin, R. G., and Street, J.: 1981, J. Environ. Qual. 10(2), 225.
Davis, J. A., and Leckie, J. O.: 1978, Environ. Sci. Technol. 12(2), 1309.
Dean, J. A.: 1992, Lange's Handbook of Chemistry, 14th ed., McGraw-Hill Book Company, New York, pp. 5\s-77–5\s-91.
Elliott, H. A., and Brown, G. A.: 1989, Water, Air, and Soil Pollut. 45, 361.
Elliott, H. A., and Denneny, C. M.: 1982, J. Environ. Qual. 11(4), 658.
Elliott, H. A., and Huang, C. P.: 1979, J. Colloid Interface Sci. 70(1), 29.
Elliott, H. A., and Huang, C. P.: 1981, Water Res. 15, 849.
Eykholt, G. R.: 1992, Driving and complicating features of the electrokinetic treatment of contaminated soils, Ph.D. Dissertation, University of Texas at Austin.
Garnett, K., Kirk, P. W. W., Lester, J. N., and Perry, R.: 1985, J. Environ. Qual. 14(4), 549.
Garnett, K., Kirk, P. W. W., Perry, R., and Lester, J. N.: 1986, Environ. Pollut. (Series B) 12, 145.
Hamed, J., Acar, Y. B., and Gale, R. J.: 1991, J. Geotech. Engineer. 117(2), 241.
Huang, C. P., Rhoads, E. A., and Hao, O. J.: 1988, Water Res. 22(8), 1001.
Lageman, R., Pool, W., and Seffinga, G.: 1989, Chemistry and Industry (18 Sept.), 585.
Lester, J. N., Harrison, R. M., and Perry, R.: 1979, Sci. Total Environ. 12, 12.
Linn, J. H., and Elliott, H. A.: 1988, Water, Air, and Soil Pollut. 37, 449.
Lo, K. S. L. and Chen, Y. H.: 1990, Sci. Total Environ. 90, 99.
Lorenz, P. B.: 1969, Clays and Clay Minerals 17, 223.
Meites, L.: 1963, Handbook of Analytical Chemistry, McGraw-Hill Book Company, New York, p. 1–45.
Plus, R. W., Powell, R. M., Clark, D., and Eldred, C. J.: 1991, Water, Air, and Soil Pollut. 57–58, 423.
Rossin, A. C., Perry, R., and Lester, J. N.: 1982, Environ. Pollut. (Series A) 29, 271.
Runnells, D. D., and Larson, J. L.: 1986, Ground Water Monitoring and Review (Summer 1986), 81.
Sanning, G. E., and Lewis, N. M.: 1990, J. Air Waste Manage Assoc. 40(12), 1706.
Shapiro, A. P., Renauld, P., and Probstein, R.: 1989, Physicochemical Hydrodynamics 11(5/6), 785.
Stoveland, S., Lester, J. N., and Perry, R.: 1979, Water Res. 13, 949.
Author information
Authors and Affiliations
Additional information
To whom correspondence should be addressed.
Rights and permissions
About this article
Cite this article
Hong, J., Pintauro, P.N. Desorption-complexation-dissolution characteristics of adsorbed cadmium from kaolin by chelators. Water Air Soil Pollut 86, 35–50 (1996). https://doi.org/10.1007/BF00279144
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00279144