Re
mediation
mainly based on excavation and burial of the conta
minated soil is i
mpractical with regard to the large nu
mbers of sites identified as being in need of re
mediation. Therefore, alternative
methods are needed for brownfield re
mediation. This study was conducted to assess a che
mical stabilization procedure of CCA-conta
minated soil using iron (Fe)-containing blaster sand (BS) or oxygen-scarfing granulate (OSG). The stabilization technique was assessed with regard to the feasibility of
mixing a
meliorants at an industrial scale and the efficiency of the stabilization under different redox conditions. The stability was investigated under natural conditions in 1-
m3 lysi
meters in a field experi
ment, and the effect of redox conditions was assessed in a laboratory experi
ment (10 L). The treat
ments with high additions of a
meliorant (8% and 17%) were
more successful in both the laboratory and field experi
ments, even though there was enough Fe on a stochio
metric basis even at the lowest addition rates (0.1% and 1%). The particle size of the Fe and the
mixing influenced the stabilization efficiency. The develop
ment of anaerobic conditions, si
mulated by water saturation, increases the fraction of arsenic (AsIII) and, consequently, As
mobility. The use of high concentrations of OSG under aerobic conditions increased the concentrations of nickel (Ni) and copper (Cu) in the pore water. However, under anaerobic conditions, it decreased the As leaching co
mpared with the untreated soil, and Ni and Cu leaching was not critical. The final destination of the treated soil should govern the a
mend
ment choice, that is, an OSG concentration of approxi
mately 10%
may be suitable if the soil is to be landfilled under anaerobic conditions. Alternatively, the soil
mixed with 1% BS could be kept under aerobic conditions in a landfill cover or in situ at a brownfield site. In addition, the treat
ment with BS appeared to produce better effects in the long ter
m than treat
ment with OSG.
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