Han Ziyu, Li Shaohua, Yue Yong, Tian Yao, Wang Shiyu, Qin Zhirui, Ji Longjie, Han Denglun, Jiao Wentao
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing, 100085, PR China.
Sinochem Environment Holdings Co. Ltd., Beijing, 100070, China.
Environ Res. 2021 Jul;198:110457. doi: 10.1016/j.envres.2020.110457. Epub 2020 Nov 11.
Soil polycyclic aromatic hydrocarbons (PAHs) contamination caused by factory relocations is a serious environmental issue across the world. Electrical resistance heating (ERH) and chemical oxidation are two promising in-situ methods for treating volatile and semi-volatile organic pollutants in contaminated soil. Coupling of ERH and chemical oxidation technologies to improve the remediation efficiency for PAH-contaminated soil was estimated in this study. PAH removal ratio in contaminated soils using ERH treatment were significantly negatively correlated with the boiling point of the pollutants (P = 0.002), and 21.63% (DBA high boiling point) to 71.53% (Nap low boiling point) of PAHs in the contaminated soil were removed in 120 min. With oxidant NaSO coupling, the removal ratio were increased as more oxidant was added. For one Phe, 35.90% was removed by ERH treatment and increased to 52.90% and 79.42% when 0.05 or 2.5 mmol/g oxidant was added, respectively. PAHs with higher boiling points had more obvious removal ratio, such as Bap, which increased from 23.50% to 85.47% when coupling ERH with NaSO, and Phe which increased from 35.90% to 79.42%. Relationships between boiling points and PAH removal ratio changed with coupled oxidants, indicating a change of mechanism from volatilization to coupling effects of volatilization and oxidation with the introduction of NaSO. A dynamic experiment showed that NaSO can accelerate 45.50% of the treatment process. The results of this research demonstrated a novel, cost-effective coupling approach for remediating soil contaminated by organic pollutants.
工厂搬迁导致的土壤多环芳烃（PAHs）污染是一个全球性的严重环境问题。电阻加热（ERH）和化学氧化是处理污染土壤中挥发性和半挥发性有机污染物的两种很有前景的原位方法。本研究评估了ERH和化学氧化技术联用对提高PAH污染土壤修复效率的效果。采用ERH处理时，污染土壤中PAH的去除率与污染物沸点显著负相关（P = 0.002），在120分钟内，污染土壤中21.63%（高沸点的二苯并蒽）至71.53%（低沸点的萘）的PAHs被去除。与氧化剂NaSO联用，随着氧化剂添加量增加，去除率提高。对于一种菲，通过ERH处理去除率为35.90%，当添加0.05或2.5 mmol/g氧化剂时，去除率分别提高到52.90%和79.42%。沸点较高的PAHs去除率提升更明显，如苯并[a]芘，与NaSO联用时从23.50%提高到85.47%，菲从35.90%提高到79.42%。沸点与PAH去除率的关系随联用氧化剂而变化，表明随着NaSO的引入，作用机制从挥发转变为挥发与氧化的联合作用。动态实验表明，NaSO可使处理过程加速45.50%。本研究结果证明了一种用于修复有机污染物污染土壤的新型、经济高效的联用方法。
