Institute of Organic Contaminant Control and Soil Remediation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Soil and Water Department, Faculty of Agriculture, Kafrelsheikh University, Kafr El-Sheikh, Egypt.
Chemosphere. 2022 Aug;301:134715. doi: 10.1016/j.chemosphere.2022.134715. Epub 2022 Apr 26.
Partition and adsorption of polycyclic aromatic hydrocarbons (PAHs) are critical mechanisms determining their fate at the solid-liquid interface. The complexity of soil composition makes it difficult to distinguish between partition and adsorption, and bates the accuracy of the research results. This study found that the composition and structure of the soil particles (SAs) of varying particle sizes were significantly different. Partition contributed significantly to phenanthrene (Phe) sorption in SAs over 0.002 mm. However, PAHs had the highest sorption coefficient (K) in SA less than 0.002 mm (SA-3), and the lower aqueous phase equilibrium concentration of Phe, the greater the adsorption effect. According to morphology and structural analysis, Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), interactions of micropores, soil organic matter (SOM) and minerals enhanced the sorption of PAHs. Additionally, thermogravimetry and mass spectrometry (TG-MS) results proved that SOM could inhibit the release of PAHs adsorbed in SAs during heating process. We observed that the Log Koc of PAHs was the most important factor in determining the K in SAs applying principal component analyses (PCA), and they have significant linear relationships (R = 0.79-0.93). These findings provide new understandings on interface reactivity of PAHs sorption to soils and the development of interface model.
多环芳烃（PAHs）的分配和吸附是决定其在固-液界面上命运的关键机制。土壤成分的复杂性使得区分分配和吸附变得困难，并影响了研究结果的准确性。本研究发现，不同粒径土壤颗粒（SAs）的组成和结构有显著差异。对于粒径大于 0.002mm 的 SAs，分配对菲（Phe）的吸附有显著贡献。然而，在粒径小于 0.002mm 的 SAs（SA-3）中，PAHs 的吸附系数（K）最高，并且水中 Phe 的平衡浓度越低，吸附效果越大。根据形态和结构分析，傅里叶变换红外（FTIR）和 X 射线光电子能谱（XPS）表明，微孔、土壤有机质（SOM）和矿物质之间的相互作用增强了 PAHs 的吸附。此外，热重和质谱（TG-MS）结果证明，在加热过程中 SOM 可以抑制吸附在 SAs 中的 PAHs 的释放。我们观察到，应用主成分分析（PCA），PAHs 的 Log Koc 是决定 SAs 中 K 的最重要因素，它们之间存在显著的线性关系（R=0.79-0.93）。这些发现为 PAHs 吸附到土壤界面反应性的理解和界面模型的发展提供了新的认识。
