Characteristics and ecological risk assessment of polycyclic aromatic hydrocarbons in soil seepage water in karst terrains, southwest China

Sun, Y., Zhang, S., Xie, Z., Lan, J., Li, T., Yuan, D., Yang, H. ORCID: https://orcid.org/0000-0001-9940-8273 and Xing, B. (2020) Characteristics and ecological risk assessment of polycyclic aromatic hydrocarbons in soil seepage water in karst terrains, southwest China. Ecotoxicology and Environmental Safety, 190. 110122. ISSN 0147-6513 doi: 10.1016/j.ecoenv.2019.110122

Abstract/Summary

Concentrations of polycyclic aromatic hydrocarbons (PAHs) in soils and soil seepage waters were analyzed along with dissolved organic carbon (DOC) to investigate the ecological risks and factors controlling the subsurface transport of PAHs in karst terrain in southwest China. The concentrations of dissolved PAHs in soil seepage water increased with depth and the mean concentrations at a depth of 80 cm were relatively high (exceeding 1147 ng/L). PAH composition in soil seepage water was dominated by low molecular weight (LMW) PAHs, whereas those associated with soil matrix were dominated by high molecular weight (HMW) PAHs. The results revealed that HMW PAHs in soil seepage water were closer to the equilibrium of dissolution than LMW and medium molecular weight (MMW) PAHs. However, due to the carrier functions of dissolved organic matter (DOM) for HMW PAHs, all PAHs can be continuously dissolved in the soil seepage water from soil matrix as the water moved vertical downward through the profiles. During this process, dynamic sorption and desorption processes were occurring between constituents in the soil seepage water and the soil matrix. This study demonstrates soil seepage water has posed a high risk to the groundwater, and effective protection is urgently needed.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/88507
Identification Number/DOI	10.1016/j.ecoenv.2019.110122
Refereed	Yes
Divisions	Science > School of Archaeology, Geography and Environmental Science > Department of Geography and Environmental Science
Publisher	Elsevier
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