Title: Remediation of chlorinated solvents by stimulated reductive dechlorination. Main report 
Resource Type: document --> technical publication --> report 
Country: Denmark 
Language(s): Danish
English
 
Year: 2003 
Availability: Environmental project, Miljørapport nr.833 
Author 1/Producer: Mossing, C. 
Other Authors/Producers: Bjerg, P.L. 
Author / Producer Type: Agency, regulator or other governmental or inter-governmental body 
Publisher: The Danish Environmental Protection Agency, Miljøstyrelsen 
Publisher City: Strandgade 29, DK-1405 Copenhagen K, Denmark 
ISBN: 87-7972-827-8 
Report / download web link (=direct link): http://www2.mst.dk/common/Udgivramme/Frame.asp?pg=http://www ...  
Format (e.g. PDF): PDF 
Size: (e.g. 20mb) 964 
EUGRIS Keyword(s): Contaminated land-->Remediation options-->In situ treatment technologies
 
Short description: A pilot study on the stimulated natural degradation of chlorinated solvents in groundwater at a contaminated former dry cleaning establishment has been carried out. Degradation is stimulated by addition of an organic compound (HRCTM) to groundwater. Despite uneven distribution of HRC in the groundwater zone, the groundwater chemistry has been changed in some zones producing more favourable conditions for the degradation of chlorinated solvents. No degradation has however been detected presumably due to the absence of appropriate groundwater bacteria. 
Long description: Reductive dechlorination has been stimulated in a pilot study whereby significant changes in groundwater chemistry from oxidised to strongly reduced redox conditions ideal for the degradation of chlorinated solvents are provoked. The amount of substrate (HRCTM - Hydrogen release compound) needed is determined by the amount of competing electron acceptors – not the degree of contamination. The pilot test has been carried out approximately 100 meter down gradient of the former dry cleaning facility, where the contaminant plume is found in both an upper and lower aquifer. The contamination primarily consists of PCE and to a lesser extent of TCE with no significant levels of daughter products like cis-DCE. The highest concentrations are seen in the upper aerobic aquifer (app. 500 ìg/l), whereas the lower mildly anaerobic aquifer has lower concentrations of about 50 ìg/l. After addition of the substrate (based on lactates), a rapid removal of nitrate and sulfate and the production of iron(II) and later methane is observed. Apparently ideal conditions for reductive dechlorination are established in some parts of the lower aquifer over a longer period of time, but no degradation is observed presumably due to lack of bacterial adaptation. 
Submitted By: Dr Jacqueline Falkenberg WhoDoesWhat?      Last update: 02/04/2007