Key Laboratory of Humid Subtropical Eco-geographical Process, Ministry of Education, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China.
Environ Sci Pollut Res Int. 2017 Oct;24(28):22332-22339. doi: 10.1007/s11356-017-9919-z. Epub 2017 Aug 11.
Soil organic matter (SOM) is the main adsorbent for polycyclic aromatic hydrocarbons (PAHs) and the principal aggregating agent for soil aggregation that can affect PAH bioavailability and bioaccessibility in soils. The objective of this study was to analyze the relationship between PAH dissipation and variation in soil aggregate-size distribution in two field-contaminated soils with different soil organic C (SOC) content (Anthrosols, 1.41% SOC; Phaeozems, 8.51% SOC) in phytoremediation with alfalfa. The results showed that there were significant reductions of 10.2 and 15.4% of the total PAHs in unplanted and planted treatments, respectively, for Anthrosols. However, there was no significant reduction of total PAHs in either unplanted or planted treatment for Phaeozems. For Anthrosols, mass percentages of coarse sand and fine sand were significantly reduced while coarse silt and fine silt were significantly increased for the planted soil compared to the initial soil (p < 0.05). For Phaeozems, there was no significant variation in aggregate-size distribution among different treatments except that coarse silt in planted and unplanted soil was slightly reduced. The main reason for the dissipation of PAHs in Anthrosols could be that macroaggregates were broken into microaggregates, which made some trapped PAHs become bioaccessible to soil microorganisms.
土壤有机质（SOM）是多环芳烃（PAHs）的主要吸附剂，也是土壤团聚体的主要团聚剂，它可以影响土壤中 PAH 的生物有效性和生物可利用性。本研究的目的是分析在两种不同土壤有机碳（SOC）含量的农田污染土壤（Anthrosols，SOC 含量为 1.41%；Phaeozems，SOC 含量为 8.51%）中，用紫花苜蓿进行植物修复时，PAH 消解与土壤团聚体粒径分布变化之间的关系。结果表明，Anthrosols 未种植和种植处理的总 PAHs 分别减少了 10.2%和 15.4%。然而，在 Phaeozems 中，未种植或种植处理的总 PAHs 均无显著减少。对于 Anthrosols，与初始土壤相比，种植土壤的粗砂和细砂质量百分比显著降低，而粗粉砂和细粉砂质量百分比显著增加（p<0.05）。对于 Phaeozems，除了种植和未种植土壤中的粗粉砂略有减少外，不同处理之间的团聚体粒径分布没有显著变化。Anthrosols 中 PAHs 消解的主要原因可能是大团聚体被分解成微团聚体，从而使一些被截留的 PAHs 变得可被土壤微生物利用。
