HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Scow, K. M. Articles by Hutson, J. Search for Related Content PubMed Articles by Scow, K. M. Articles by Hutson, J. Agricola Articles by Scow, K. M. Articles by Hutson, J.

Effect of Diffusion and Sorption on the Kinetics of Biodegradation: Theoretical Considerations

Dep. of Land, Air, and Water Resources, Univ. of California, Davis, CA 95616

John Hutson

Dep. of Soil, Crop, and Atmospheric Sciences, Cornell Univ., Ithaca, NY 14853. Contribution of the Dep. of Soil, Crop, and Atmospheric Sciences, Cornell Univ.

ABSTRACT

Organic chemicals subject to biodegradation by microorganisms in soil are often limited in their availability by sorption and diffusion to unavailable sites. To quantitatively describe biodegradation under conditions of substrate limitation, a process-based deterministic model called the diffusion-sorption-biodegradation (DSB) model was developed to describe the biodegradation of an organic chemical in the presence of spherical aggregates. Diffusion is described by Fick's second law, sorption by a linear isotherm, and biodegradation by one of various rate equations including first-order kinetics. Sensitivity analyses were performed to determine the dependence of a chemical's half-life on soil physical and chemical properties. Half-lives in the presence of aggregates were substantially greater than equivalent half-lives in the absence of aggregates when the sorption partition coefficient was 3.2 dm³kg^-1 and the aggregate radius was 0.32 cm. The two-compartment model provided a better fit than did a simple first-order model to simulations of the biodegradation of a sorbing chemical in the presence of large (0.25-cm radii) aggregates, whereas there was no difference between the two models for aggregates of much smaller radii. When simple first-order kinetics was assumed without accounting for diffusion and sorption, long-term extrapolation of chemical persistence in the presence of aggregates overestimated the degradation of a chemical with a sorption partition coefficient of 10 dm³kg^-1. Considering that many organic pollutants sorb strongly and numerous soils have some degree of aggregate structure and organic matter, taking into account the physical and chemical processes affecting a chemical's concentration may greatly improve kinetics models of biodegradation in soil.

^* Corresponding author.

Received for publication September 19, 1990.

This article has been cited by other articles:

				J. A. Tompkins, J. A. Tompkins, S. R. Smith, E. Cartmell, and H. S. Wheater In-situ bioremediation is a viable option for denitrification of Chalk groundwaters Quarterly Journal of Engineering Geology and Hydrogeology, February 1, 2001; 34(1): 111 - 125. [Abstract] [Full Text] [PDF]

				R. U. Halden, B. G. Halden, and D. F. Dwyer Removal of Dibenzofuran, Dibenzo-p-Dioxin, and 2-Chlorodibenzo-p-Dioxin from Soils Inoculated with Sphingomonas sp. Strain RW1 Appl. Envir. Microbiol., May 1, 1999; 65(5): 2246 - 2249. [Abstract] [Full Text]