Soil oxidant demand for remediation of PAHs contaminated plots

Abstract

In order to better guide the dosage of chemical oxidants in the remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated soil, KMnO4, Na2S2O8 and H2O2 were selected to study the kinetics, soil oxidant demand (SOD) and its influencing factors under four different plant areas in Chengdu, China. The results showed that KMnO4 and H2O2 are rapidly consumed within 1 d. The consumption rate decreases rapidly after 1 d of the reaction, while the consumption rate of Na2S2O8 is relatively stable. The reaction laws of the three oxidants are basically consistent with the first order kinetics. When the doses of KMnO4, Na2S2O8 and H2O2 are 1, 2 ,12 mmol/g, the SOD ranges of KMnO4, Na2S2O8, and H2O2 for each plot are 44.91～96.06, 40.91～52.86, and 371.47～406.25 g/kg, respectively. Statistical analysis show that the maximum demands of KMnO4 and Na2S2O8 are significantly correlated with soil organic matter content, soil clay and soil water content. Among them, soil organic matter content has the greatest effect on the soil oxidant demand of KMnO4 and Na2S2O8, with the contribution rates reaching 31.57% and 40.24%, respectively. According to the experimental results and considering the economic factors, the oxidants KMnO4 and Na2S2O8

Keywords

• materials chemistry
• polycyclic aromatic hydrocarbons
• chemical oxidation
• soil oxidant demand
• site remediation
• potassium permanganate
• sodium persulfate
• hydrogen peroxide