2020 Volume 15 Issue 3 Pages 563-571
This study evaluated the long-term stability soil contaminated with mercury and fluorine treated by in-situ insolubilization treatment. It is necessary to (1) quantitatively evaluate the elution suppression effect of the in-situ stabilization method and (2) understand the behavior of re-eluted contaminants. The former was evaluated by laboratory tests using insolubilized contaminated soil taken at an actual remediation project site. The latter was examined by numerical analysis simulating the behaviour of re-eluted contaminants. Based on the tests and analysis, it was expected that the elution from insolubilized mercury-contaminated soil would be sustained below environmental standard for 130 years and that from insolubilized fluorine-contaminated soil for more than 1,800 years. In the case of mercury, its dispersion would be limited less than 0.02m even after 100 years, due to insolubization which changed the chemical form of contaminants and decrease the water permeability of soil. It was concluded that it is possible to quantitatively evaluate the long-term elution suppression effect of in-situ insolubilization treatment.
