Pump-and-Treat Remediation of Chlorinated Solvent Contamination at a Controlled Field-Experiment Site
| Autor: | Richelle M. Allen-King, Steven W. Chapman, John A. Cherry, Stanley Feenstra, Michael O. Rivett |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Environmental remediation
Mineralogy Aquifer Sensitivity and Specificity Water Purification Orders of magnitude (specific energy) Water Supply Hydrocarbons Chlorinated Water Movements Environmental Chemistry Water Pollutants Extraction (military) Dissolution geography geography.geographical_feature_category Water Sorption General Chemistry Models Theoretical Plume Solvents Environmental science Chlorine Water Pollutants Chemical Groundwater Environmental Monitoring |
| Zdroj: | Environmental Science & Technology. 40:6770-6781 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es0602748 |
| Popis: | Pump-and-treat (PT) remediation and associated concentration tailing are investigated at the field scale in a mildly heterogeneous sandy aquifer through the extraction of dissolved chlorinated solvent plumes that had developed over 475 d from a multicomponent dense nonaqueous-phase liquid (DNAPL) source intentionally emplaced in the aquifer at the Borden (ON) research site. Extraction was accomplished via a source-containment well located 25 m from the source and two further downgradient plume-centerline wells to remove the advancing high-concentration dissolved plumes. The 550 days of detailed PT field data demonstrated the following: remediation, albeit slowly, of the leading 25-60 m plume section to around typical drinking water standard concentrations; concentration tailing (reduction) over 4 orders of magnitude in the plume; a steady-state concentration "plateau" in the source-containment well capturing the steadily dissolving DNAPL source; influences of extraction rate changes (concentration rebounds); and, lengthy tailing from inter-well stagnation-zone areas. Much of the contaminant behavior during the PT appeared to be "ideal" in the sense that with appropriate specification of the source term and pumping regime, it was reasonably predicted by 3-dimensional numerical model (HydroGeoSphere) simulations that assumed ideal (macrodispersion, linear sorption, etc.) transport. Supporting lab studies confirmed nonideal sorption was, however, important at the point sample scale with enhanced PCE (tetrachloroethene) sorption to low- and high-permeability strata and moderate nonlinear and competitive sorption influences. Although there was limited evidence of nonideal tailing contributions to the field data (underprediction of some tailing curve gradients), such contributions to PT tailing were not easily discerned and appeared to play a relatively minor role within the mildly heterogeneous aquifer studied. |
| Databáze: | OpenAIRE |
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