The impact of solidification and stabilization effects on arsenic (As) contaminated soil before and after repeated freezing and thawing or high temperature aging was investigated by tests of unconfined compressive strength (UCS), permeability, leaching concentration and fractionation. The microstructure appearance of the soil was observed using SEM. The results show that the UCS of solidified soil decreases and its permeability increases after repeated freezing and thawing or high temperature aging. In stabilized soil, the unstable species of As increase and the leaching concentration of As rises accordingly after both treatments. The concentration of unstable species of As increased accordingly by 19.81% and 25.1%, and the leaching concentration rose from 115.5 μg·L-1 to 151.5 μg·L-1 and 164.5 μg·L-1 respectively after 300 freeze-thaw treatments or under 10 h of high temperature aging under 80℃. In general, the influence of the effects increases with more freeze-thaw events and higher temperature aging of longer duration. More damage and fragmentation was observed after both treatments.
Keywords: arsenic; contaminated soil; high temperature aging; repeated freezing and thawing; solidification and stabilization.