Location: National Soil Dynamics Laboratory
Title: Phytoremediation of polychlorinated biphenyl (PCB) contaminated sediments: A greenhouse feasibility study Authors
|Schwab, A - PURDUE UNIVERSITY|
|Banks, M - PURDUE UNIVERSITY|
Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 1, 2006
Publication Date: January 9, 2007
Citation: Smith, K.E., Schwab, A.P., Banks, M.K. 2007. Phytoremediation of polychlorinated biphenyl (PCB) contaminated sediments: A greenhouse feasibility study. Journal of Environmental Quality. 36:239-244. Interpretive Summary: A greenhouse study was conducted to evaluate the ability of plant species to remediate highly chlorinated polychlorinated biphenyls (PCBs). We found that sediments treated with an organic amendment that either had no plants or low-transpiring plants had the greatest removal of PCBs. Highly chlorinated PCBs require anaerobic conditions as the first step in remediation, our results indicate that the presence of high transpiring plant species prevented the first step of remediation required for highly chlorinated PCBs. Our recommendation is that highly chlorinated sediments be kept under anaerobic conditions until most of the highly chlorinated PCBs have been dechlorinated. At this point plant species can be introduced and should enhance the loss of the remaining PCBs. Based on our statistical analysis, we would recommend using sedge and prairie cord grass at this point in the remediation of PCB contaminated sediments.
Technical Abstract: Contaminated sediments dredged from navigable waterways often are placed in confined disposal facilities to prevent further spread of the pollutants. Reducing contaminants to acceptable levels would allow for disposal of the sediments and further dredging activity. A greenhouse study was conducted to evaluate plant treatments and the addition of compost to decrease the concentration of PCB congeners found in Arochlor 1260. Sediment treated with the amendment and either low transpiring plants or no plants had the greatest removal of the PCB congeners. High-transpiring plants apparently prevented the highly reducing conditions required for reductive dechlorination of highly chlorinated PCBs. Most likely, the amendment provided labile carbon that initiated the reducing conditions needed for dechlorination. The sediment moisture content and moisture-related plant parameters were significant predictors of the PCB loss. Carex aquatalis and Spartina pectinata are predicted to be the most effective plant treatments for phytoremediation of PCBs.