Application of Natural Attenuation to Ground Water Contaminated by Phenoxy Acid Herbicides at an Old Landfill in Sjoelund, Denmark |
| |
| Authors: | Nina Tuxen Palle Ejlskov Hans-Jørgen Albrechtsen Lotte A Reitzel Jørn K Pedersen Paul L Bjerg |
| |
| Institution: | Nina Tuxen;(Environment &Resources, Technical University of Denmark, Bygningstorvet 115, 2800 Kgs. Lyngby, Denmark;) is a research assistant professor of environment and resources at the Technical University of Denmark. She has an M.S. in environmental engineering and a Ph.D. with special emphasis on ground water pollution, natural attenuation, and pesticides from the Technical Univeristy of Denmark. Palle Ejlskov;(Ejlskov Consult A/S, Rolighedsvcj 30, 8240 Risskov, Denmark;) is the director of Ejlskov Consult, a company conducting environmental site characterization and remedial activities at contaminated sites. He has an M.S. in geology from Aarhus University. Hans-Jorgen Albrecthsen;(Environment &Resources, Technical University of Denmark, Bygningstorvet 115, 2800 Kgs. Lyngby, Denmark;) is an associate professor of environment and resources at the Technical University of Denmark. His research interests are microbiology, drinking water, and fate of xenobiotic contaminants in ground water. Lotte A. Reitzel;(Environment &Resources, Technical University of Denmark, Bygningstorvet 115, 2800 Kgs. Lyngby, Denmark;) is a Ph.D. student at the Technical University of Denmark, working with natural attenuation of xenobiotic compounds. She is an environmental chemist from the University of Copenhagen. Jorn K. Pedersen;(Sonderjyllands Amt, Grundvandsafdelingen, Jomfrustien 2, 6270 Tonder, Denmark;) is employed by the County of Sonderjylland, Denmark, and works with water resources and ground water contamination. He has an M.S. in civil engineering and a Ph.D. from the Technical University of Denmark. Poul L. Bjerg;(Environment &Resources, Technical University of Denmark, Bygningstorvet 115, 2800 Kgs. Lyngby, Denmark;) is a professor of environment and resources at the Technical University of Denmark. His research interests are ground water contamination, remediation technologies, pesticides, and landfill leachate. |
| |
| Abstract: | Investigations of geology, hydrogeology, and ground water chemistry in the aquifer downgradient from Sjoelund Landfill, Denmark, formed the basis for an evaluation of natural attenuation as a remediation technology for phenoxy acid herbicides at the site. Concentrations of phenoxy acids were up to 65 μg/L in the ground water, primarily 4-chlor-2-methylphenoxypropionic acid (MCPP) and 2,4-dichlorophenoxypropionic acid (dichlorprop). Mass removal of the phenoxy acids was shown within 50 to 100 m of the landfill by calculation of contaminant fluxes passing transects at three distances. There was accordance between increasing oxygen concentrations and decreasing phenoxy acid concentrations with distance from the landfill, indicating that aerobic degradation was a major mass removal process. Presence of high concentrations of putative anaerobic phenoxy acid metabolites suggested that anaerobic degradation was also occurring. Laboratory degradation experiments using sediment and ground water from the aquifer supported aerobic and anaerobic degradability of MCPP at the site. It was concluded that natural attenuation may be applicable as a remedy for the phenoxy acids at the Sjoelund Landfill site, although uncertainties related to calculations of chloride and phenoxy acid fluxes at a complex site and identification of specific in situ indicators were encountered. Thus, there is a pronounced need for development and broader experience with evaluation tools for natural attenuation of phenoxy acids, such as specific metabolites, changes in enantiomeric fractions, compound-specific stable carbon isotope ratios, or microbial fingerprints. |
| |
| Keywords: | |
|
|
