优化SO4-·高级氧化技术修复PAHs复合污染土壤

采用硫酸根自由基高级氧化技术（SR-AOPs）修复南京某炼钢厂附近PAHs复合土壤，通过调整过硫酸钠（Na2S2O8）和亚铁离子（Fe²⁺）比例，结合添加不同种类和浓度的螯合剂和表面活性剂，获得修复的最佳条件，并比较分析不同类型PAHs的降解特征.结果表明：Na₂S₂O₈和Fe²⁺的配比显著影响土壤PAHs的降解效果，当Na₂S₂O₈用量为5mmol/g，Fe²⁺用量为0.5mmol/g，二者比例为10：1时，培养24h，PAHs总去除率最高，为29.32%；在此基础上添加螯合剂柠檬酸0.5mmol/g时，PAHs总去除率可提高至49.9%；继续添加0.27mg/g表面活性剂IGEPAL CA-720，PAHs总去除率最大，为80.8%.分析不同条件下SR-AOPs对PAHs的降解效果，得到总体上SR-AOPs对四环PAHs去除效果最好.添加柠檬酸和IGEPAL CA-720可以进一步强化对土壤中3环、6环PAHs的去除.柠檬酸和IGEPAL CA-720的添加可以更有效去除污染土壤中PAHs，尤其是针对高环PAHs.

Optimization of sulfate radical advanced oxidation technology on PAHs remediation in contaminated sites

Sulfate radical-based advanced oxidation processes (SR-AOPs)was used to remediate PAHs contaminated soils near a steel mill in Nanjing. The ratio of sodium persulfate (Na₂S₂O₈) and ferrous ion (Fe²⁺) used in the SR-AOPs was adjusted, combined with various types and concentrations of chelating agents and surfactants, to reach the best PAHs removal efficiency. Meanwhile, the degradation characteristics of different types of PAHs were analyzed. The results showed that the ratio of Na₂S₂O₈ and Fe²⁺ significantly influenced the PAHs degradation efficiencies. The highest removal rate of PAHs was 29.32% at the condition of 24hours incubation when the ratio of Na₂S₂O₈ and Fe²⁺ was 10:1, i.e. the dose of Na₂S₂O₈ was 5mmol/g and the Fe²⁺ dosage was 0.5mmol/g. Base on this, 0.5mmol/g citric acid was added as the best chelating agent which could further improve the PAHs removal rate to 49.9%. In addition, 0.27mg/g surfactant IGEPAL CA-720 could also increase the PAHs removal rate to 80.8%. In general, the tetracyclic PAHs showed the highest removal rate by SR-AOPs. The addition of citric acid and IGEPAL CA-720 could further promote the removal of tricyclic PAHs and pentacyclic PAHs in soil. In conclusion, the citric acid and IGEPAL CA-720 addition could help to facilitate the removal of PAHs in soils, especially for the high-ring PAHs.