Multiyear Temporal Changes in Chlorinated Solvent Concentrations at 23 Monitored Natural Attenuation Sites
| Autor: | Iain Cowie, Walt W. McNab, Charles J. Newell, Travis M. McGuire |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
chemistry.chemical_classification
Environmental Engineering Environmental remediation Organic solvent Mineralogy Half-life Chlorinated solvent chemistry Environmental chemistry Groundwater pollution Environmental Chemistry Volatile organic compound Statistical analysis Water pollution General Environmental Science Civil and Structural Engineering |
| Zdroj: | Journal of Environmental Engineering. 132:653-663 |
| ISSN: | 1943-7870 0733-9372 |
| Popis: | Long-term e.g., 5-15 years groundwater concentration versus time records were compiled from 47 near-source zone moni- toring wells at 23 chlorinated solvent sites 52 total records. Chlorinated volatile organic compound CVOC concentrations decreased significantly in most of the 52 temporal records, with a median reduction in concentration of 74%. A statistical method based on a Mann-Kendall analysis also showed that most sites had statistically significant decreasing concentration trends over time. Median point decay rate constants kpoint values were calculated for nine sites containing tetrachloroethene PCE; 13 sites containing trichloroethene TCE; two sites containing cis-1,2-dichloroethene DCE; and six sites containing 1,1,1-trichloroethane TCA. The TCA sites had the highest kpoint values 0.34/year followed by PCE, DCE, and TCE 0.23/year, 0.16/year, and 0.11/year, respectivelyequal to decay half-lives of 2.0, 3.0, 4.3, and 6.1 years, respectively. If the median point decay rates from these sites are maintained over a 20 year period, the resulting reduction in concentration will be similar to the reported reduction in source zone concentrations achieved by active in situ source remediation technologies typical project length: 1-2 years. |
| Databáze: | OpenAIRE |
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