Soil washing, ozofractionation and metal sequestration: removing organic and inorganic species from contaminated soil and water
Most research of soil washing conducted around the world has involved the removal of inorganic species from contaminated soil matrices. Few have considered its potential for removing organic species, although it has been used to remove volatile organic compounds and diesel. Similarly, a significant amount of research has considered the roles of advanced oxidation and ozonation in destroying organic species in water, but few have examined the potential of ozofractionation to perform this role. The purpose of this study was to assess the capacity of soil washing to remove both organic and inorganic species from a complex contaminated industrial soil, and once contaminants had been liberated from the solid phase, examine whether ozofractionation destroyed organic and inorganic species and whether a chemical reagent sequestered inorganic species in the flushing solution. Findings suggest that soil washing had a salutary effect on liberating organic and inorganic species from contaminated soil, reducing total petroleum hydrocarbons, for example, from 1,290 mg/kg to 320 mg/kg. The study also found that ozofractionation destroyed organic and inorganic species, for example reducing polycyclic aromatic hydrocarbons from 13.2 mg/L to <0.5 mg/L and cyanide from 5.9 mg/L to 0.02 mg/L, and reagents sequestered heavy metals in the flushing solution.