不同化学氧化剂对土壤中多环芳烃的降解效果

选取被多环芳烃（PAHs）污染的土壤作为试验样本，应用4种化学氧化剂降解土壤中16种多环芳烃，对比不同氧化剂的降解效果，筛选最佳氧化剂并优化氧化条件. 结果表明：采用双氧水、改性Fenton试剂、高锰酸钾、活化过硫酸钠均可以降解土壤中的多环芳烃，其降解效率依次为：高锰酸钾（94.06%）>活化过硫酸钠（82.79%）>改性Fenton（81.15%）>双氧水（72.91%）. 高锰酸钾能高效、稳定地降解16种多环芳烃，对单个多环芳烃的降解率均在80%以上，土壤中多环芳烃的残留量均在标准范围内. 当添加量为2.5 mol/kg、水土比为7.5、反应时间为48 h时，高锰酸钾降解多环芳烃的效率最高，达到95.96%. 化学氧化剂可以有效降解土壤中的多环芳烃，高锰酸钾的降解效果最好，具有较好的应用前景.

Degradation effects of different chemical oxidants on polycyclic aromatic hydrocarbons in soil

The soil polluted by polycyclic aromatic hydrocarbons (PAHs) was taken as test samples, and four types of chemical oxidants were applied to remove 16 PAHs from the soil. Their degradation effects were compared to select the most effective oxidant to remove 16 PAHs, and then optimize the oxidation conditions for this oxidant. Based on the results, potassium permanganate, activated sodium persulfate, modified Fenton, and hydrogen peroxide proved to be effective for degrading PAHs, and the degradation rate was 94.06%, 82.79%, 81.15% and 72.91%, respectively. Specifically, potassium permanganate showed remarkable improvement in degradation efficiency compared with other oxidants. The degradation rate of potassium permanganate for each PAH was more than 80%, and the residual PAHs contents in soil were below the standard limit values. What’s more, the best remediation performance of potassium permanganate achieved 95.96% with oxidant dosage of 2.5 mols per 1 kg soil, liquid/solid ratio of 7.5, and the contact time of 48 h. The chemical oxidants are availible to degrade PAHs efficiently from contaminated soil, and potassium permanganate appears to have great prospects of application to degrade PAHs for its best performance on PAHs degradation.