| Autor: |
R. S. Achin, A. P. Gamerdinger, R. W. Traxler |
| Rok vydání: |
1997 |
| Předmět: |
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| Zdroj: |
Soil Science Society of America Journal. 61:1618-1626 |
| ISSN: |
0361-5995 |
| DOI: |
10.2136/sssaj1997.03615995006100060012x |
| Popis: |
Naphthalene sorption and biodegradation were quantified in three soils of varying organic C content using miscible displacement and batch incubation techniques. As anticipated, sorption increased with organic C content; the sorption rate coefficient and equilibrium sorption constant (K d ) were inversely related. Organic matter in solution (NOM) from the high-organic-matter soil decreased apparent sorption, which was also quantified using methanol as a cosolvent. A cosolvency power of 3.8 or 4.1 was determined. The initial biodegradation rate decreased with increasing sorption and was a function of naphthalene concentration in solution. The extent of biodegradation was greatest in the high-organic-matter soil and decreased when NOM was removed from the system. The observed dependence of biodegradation kinetics on sorption (this study and in the literature) prompted us to develop a simple approach for approximating a biodegradation rate constant for soil-water systems. This approach combines independently determined sorption parameters with the biodegradation rate constant determined for aqueous (soil-free) solution. The approach was applied to our data and to published data where sorption was shown to control naphthalene biodegradation. The approximated biodegradation rate constant was within 10% of the measured values for three cases, 20% for a fourth case, and was underestimated by five-to sevenfold for the high-organic-matter soil. The approach will be useful when applying management models for predicting contaminant fate and transport that require a degradation rate constant, or for estimating biodegradation rates in situations where cultured organisms are introduced for biodegradation. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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