Ranc Bérénice, Faure Pierre, Croze Véronique, Lorgeoux Catherine, Simonnot Marie-Odile
Laboratoire Interdisciplinaire des Environnements Continentaux, Faculté des Sciences et Technologies, UMR 7360 CNRS-Université de Lorraine, Site Aiguillettes, 54506, Vandœuvre-lès-Nancy cedex, France.
Laboratoire Réactions et Génie des Procédés, UMR 7274 CNRS-Université de Lorraine, 1 rue Grandville, 54001, Nancy cedex, France.
Environ Sci Pollut Res Int. 2017 Apr;24(12):11265-11278. doi: 10.1007/s11356-017-8731-0. Epub 2017 Mar 15.
Thermal treatments prior or during chemical oxidation of aged polycyclic aromatic hydrocarbon (PAH)-contaminated soils have already shown their ability to increase oxidation effectiveness. However, they were never compared on the same soil. Furthermore, oxygenated polycyclic aromatic hydrocarbons (O-PACs), by-products of PAH oxidation which may be more toxic and mobile than the parent PAHs, were very little monitored. In this study, two aged PAH-contaminated soils were heated prior (60 or 90 °C under Ar for 1 week) or during oxidation (60 °C for 1 week) with permanganate and persulfate, and 11 O-PACs were monitored in addition to the 16 US Environmental Protection Agency (US EPA) PAHs. Oxidant doses were based on the stoichiometric oxidant demand of the extractable organic fraction of soils by using organic solvents, which is more representative of the actual contamination than only the 16 US EPA PAHs. Higher temperatures actually resulted in more pollutant degradation. Two treatments were about three times more effective than the others: soil heating to 60 °C during persulfate oxidation and soil preheating to 90 °C followed by permanganate oxidation. The results of this study showed that persulfate effectiveness was largely due to its thermal activation, whereas permanganate was more sensitive to PAH availability than persulfate. The technical feasibility of these two treatments will soon be field-tested in the unsaturated zone of one of the studied aged PAH-contaminated soils.
在对老化的多环芳烃（PAH）污染土壤进行化学氧化之前或期间进行热处理，已显示出其提高氧化效果的能力。然而，从未在同一种土壤上对它们进行过比较。此外，作为PAH氧化副产物的含氧多环芳烃（O-PACs）可能比母体PAHs毒性更大、迁移性更强，但对其监测甚少。在本研究中，对两种老化的PAH污染土壤在氧化之前（在氩气氛围下60或90℃加热1周）或期间（60℃加热1周）分别用高锰酸盐和过硫酸盐进行处理，除了监测美国环境保护局（US EPA）规定的16种PAHs外，还监测了11种O-PACs。氧化剂剂量是根据用有机溶剂提取的土壤有机部分的化学计量氧化剂需求量确定的，这比仅考虑16种US EPA PAHs更能代表实际污染情况。较高的温度实际上导致了更多的污染物降解。两种处理方法的效果比其他方法高出约三倍：过硫酸盐氧化期间将土壤加热到60℃以及先将土壤预热到90℃然后进行高锰酸盐氧化。本研究结果表明，过硫酸盐的有效性很大程度上归因于其热活化作用，而高锰酸盐比过硫酸盐对PAH的可利用性更敏感。这两种处理方法的技术可行性很快将在其中一种研究的老化PAH污染土壤的非饱和带进行现场测试。
