Simultaneous re­mediation of explosives and lead from contaminated soil by pH-adjust­ment

• Soil washing with pH-adjusted water was evaluated in two soils containing dif­ferent concentrations of heavy metals and explosives. Overall, the most efficient treatment was with water adjusted to pH 12 by NaOH. For explosives, pH 12 removed significantly higher amounts (P<0.05) of RDX and TNT compared to pH 4 (adjusted with HNO3) and distilled water in a moderately contaminated soil (230 mg HMX/kg, 1340 mg RDX/kg, 450 mg TNT/kg). In a more highly contaminated soil (6080 mg HMX/kg, 28740 mg RDX/kg, 3120 mg TNT/kg), the pH 12-treatment was the most efficient for removal of TNT and 2,4-DNT. Explosives removal increased with treatment time, probably due to the kineti­cally slow processes underlying the explosives degradation. Mobilization of heavy metals was strongly dependent on pH, with pH 12 mobilizing more than pH 3. In addition, the change in distribution coefficient (Kd) was more pro­nounced for local contaminants Pb and Cd in comparison with Cu and Zn, which were present in background concentrations.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Environmental Sciences (hsv//eng)

Nyckelord

Environmental chemistry

Miljökemi

Enviromental Science

Miljövetenskap

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