Research on the Remediation of Soil Contaminated with Hexavalent Chromium by Chemical and Microbial Reduction
CHEN Yaojun
HUANG Shenting
Abstract：A combined chemical and microbial approach was proposed to treat high concentrations of Cr(Ⅵ)in soil.The process involved the addition of calcium polysulfide to chemically reduce the high concentrations of Cr(Ⅵ)followed by the introduction of a microbial stimulant to further reduce the remaining Cr(Ⅵ)in the stabilized soil.The study aimed to investi-gate the treatment effectiveness and remediation mechanism of Cr(Ⅵ)under different reaction conditions.The results showed that the addition of 2.5％calcium polysulfide resulted in a removal efficiency of 92.34％,reducing the Cr(Ⅵ)content in the soil to 187 mg/kg.After adding 4％lactose bio-stimulant and reacting for 60 days,the Cr(Ⅵ)content was 6.2 mg/kg,the toxic leaching concentration of Cr(Ⅵ)was 2.82 mg/L.Oxidation of the stabilized soil using potassium permanganate solution result-ed in significantly lower leaching concentrations compared to soil treated with only chemical reduction,indicating the microbi-al action effectively prevented re-oxidation of Cr(Ⅲ).The content and leaching concentration of Cr(Ⅵ)in the stabilized soil showed no significant difference before and after sterilization,demonstrating the stability of microbial reduction of Cr(Ⅵ)in the treated soil.
Keywords：soilhexavalent chromiumcalcium polysulfidemicroorganismscomposite reduction
Publication Date：2024-12-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 19-25 )