The technology was tested at a Danish DNAPL site, where the secondary aquifer was heavily contaminated by tetrachloroethene (PCE). ZVI-Clay soil-mixing was tested at a small source zone (~200 m3) with soil concentrations ranging up to 12,000 mg/kg. The objective of the field test was to document in situ destruction of the contaminant mass and the down-gradient response in contaminant mass discharge.
The field sampling consisted of baseline measurements and a 19-month monitoring program (7 sampling campaigns) subsequent to the implementation of ZVI-Clay soil mixing. The concentrations of chlorinated ethenes were monitored via soil sampling at the source zone and groundwater sampling at a control plane with multilevel samplers covering the entire contaminated plume down-gradient (3 m) of the source zone.
The results showed a significant mass depletion of PCE (2-3 orders in magnitude) with ethene as the main degradation product. The down-gradient reduction of contaminant mass discharge occurred more slowly; after 19 months a mass discharge reduction of 76 % was obtained for PCE. However, due to a temporary increase in cis-DCE, the overall down-gradient reduction of all the chlorinated ethenes was limited to 21 %. Long-term modeling (Comsol Multiphysics) was used to predict that a contaminant mass discharge reduction of 2-3 orders in magnitude will take 3-5 years.
|Title of host publication||The 2012 World Congress on Advances in Civil, Environmental, and Materials Research (ACEM´12) : Volume of Abstracts|
|Publication status||Published - 2012|
|Event||World Congress on Advances in Civil, Environmental, and Materials Research (ACEM’12) - Seoul, Korea, Republic of|
Duration: 26 Aug 2012 → 30 Aug 2012
|Conference||World Congress on Advances in Civil, Environmental, and Materials Research (ACEM’12)|
|Country||Korea, Republic of|
|Period||26/08/2012 → 30/08/2012|