FARMAK SITE: PILOT APPLICATION INTO A DEEP AQUIFER PREDOMINANTLY POLLUTED BY TRICHLOROETHYLENE (TCE)

SITE CHARACTERISTICS

Heterogenous aquifer (combination of sand, gravel and clay) together with a deep localization of CHCs contamination plume predetermine this site to be difficult to treat. Therefore, the remediation company DEKONTA arrived at an inventive decision to combine the direct-push injected NANOFER particles with a subsequent employment of the thermally enhanced in-situ bioremediation supported by the application of organic substrate (lactate).

REMEDIATION APPROACH

Iron nanoparticles were applied under pressure into a very complex geological matrix in September 2016. Ten months later, remediation was boosted by circulation and solar warming of groundwater and whey dopping. The groundwater and soil were periodically sampled before and one year after the pilot test. In-situ and ex-situ measurements of physical-chemical parameters, contamination levels, nZVI migration and fate and changes in biota were performed by employing field-ready laboratory equipment as well as advanced analytical techniques.

CONCLUSION

Pilot application of zero-valent iron nanoparticles (NANOFER 25) for remediation of a deep situated aquifer resulted in decrease in CHCs contamination but also in their wash out of clay layers. Post-application monitoring revealed main contamination source located much deeper that expected. Migration potential of NANOFER 25 was proved if using high pressure for direct-push injection. Evolution of contamination in a near-surface aquifer (the average concentrations from several wells). Due to the high level of TCE in groundwater, sulfidized iron nanoparticles (NANOFER 25DS) seem to be promising for the full scale remediation of this problematic site. A pilot test employing above mentioned brand new product is planned to be performed in summer 2018. The same amount of material is going to be injected so the results of both pilot tests can be compared.