Structure-activity relationships for the degradation of a mixture of organic chemicals in soil
The degradation rates of a mixture of volatile and semi-volatile organic compounds (N = 16) were determined by monitoring the removal of parent chemicals from two different soil types, a Captina silt loam (Typic Fragiudult) and a McLaurin sandy loam (Typic Paleudults), over a 7-day period. The compounds were applied to the soil in a mixture such that the concentration of each individual chemical was 100 ..mu..g/g soil (dry weight). Soil samples, along with sterile (autoclaved) controls, were incubated in the dark at 20/degree/C in 8 /times/ 5-cm glass jars equipped with teflon-lined stoppers and charcoal traps. Samples were disassembled, extracted with methanol, and analyzed on days 0, 2, 3, 6, and 7 of the experiment. Linear regression analysis was used to model the disappearance of the compounds from the soils. First-order degradation rate constants and half-lives were calculated. half-lives for the 16 organic compounds were relatively short (<23 days). Correlations between physicochemical parameters and half-lives were poor (r less than or equal to 0.63) for the entire data set (N = 16), however, a group of structurally related benzene derivatives (N = 7) gave good correlations in both soil types with log/sub 10/ octanol-water partition coefficient (r greater than or equal to 0.89), log/sub 10/ molecular weight (r greater than or equal to 0.84), log/sub 10/ water solubility (r greater than or equal to 0.77), and molecular connectivity (r greater than or equal to 0.83). 81 refs., 3 figs., 13 tabs.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5908573
- Report Number(s):
- ORNL/TM-11108; ON: DE89013761
- Resource Relation:
- Other Information: Thesis (M.S.). Portions of this document are illegible in microfiche products. Submitted to Univ. of Tennessee, Knoxville
- Country of Publication:
- United States
- Language:
- English
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