摘要
The stabilization of severely As-polluted soil has been a challenge, especially for the extremely toxic As(Ⅲ) contaminants. In this study, soil with a high As concentration(26084 mg/kg) was availably stabilized by a H2O2 pre-oxidation assisted TMT-15(Na3S3C3N3 solution with a mass fraction of 15%) and FeCl3·6 H2O stabilization method. The results showed that the combination of the two stabilizers(i.e., TMT-15 and FeCl3·6 H2O) presented a better stabilization behavior than either stabilizer used individually. The use of the H2O2 pre-oxidation assisted TMT-15 and FeCl3·6 H2O stabilization approach not only converted the As(Ⅲ) to As(Ⅴ) but also reduced the toxic leaching concentration of As to 1.61 mg/L, which is a safe level, when the additions of TMT-15 and FeCl3·6 H2O were 2 mL and 0.20 g, respectively. Thus, using only a simple H2O2 pre-oxidation to combine clean stabilization with non-toxic stabilizers TMT-15 and FeCl3·6 H2O could render the severely As-contaminated soil safe for disposal in a landfill.
The stabilization of severely As-polluted soil has been a challenge, especially for the extremely toxic As（Ⅲ） contaminants. In this study, soil with a high As concentration（26084 mg/kg） was availably stabilized by a H2O2 pre-oxidation assisted TMT-15（Na3S3C3N3 solution with a mass fraction of 15%） and FeCl3·6 H2O stabilization method. The results showed that the combination of the two stabilizers（i.e., TMT-15 and FeCl3·6 H2O） presented a better stabilization behavior than either stabilizer used individually. The use of the H2O2 pre-oxidation assisted TMT-15 and FeCl3·6 H2O stabilization approach not only converted the As（Ⅲ） to As（Ⅴ） but also reduced the toxic leaching concentration of As to 1.61 mg/L, which is a safe level, when the additions of TMT-15 and FeCl3·6 H2O were 2 mL and 0.20 g, respectively. Thus, using only a simple H2O2 pre-oxidation to combine clean stabilization with non-toxic stabilizers TMT-15 and FeCl3·6 H2O could render the severely As-contaminated soil safe for disposal in a landfill.
基金
financially supported by the National Key R&D Program of China (No. 2018YFC1802400)
the National Natural Science Foundation of China (No. 51604310)
the Major Project of Central Research Institute of Building and Construction (No. XAC2017Ky03)
the Opening Foundation of State Key Laboratory for Environmental Protection of Iron and Steel Industry (No. 2016YZC02)
