Research Article
Simulation Study on Vertical Migration Processes and Driving Mechanisms of Polycyclic Aromatic Hydrocarbons in Permafrost Soils
Qinxuan Bai
,
Zhiyong Han*,
Dehua Wang,
Xinpeng Wei,
Zixuan Wang,
Shiquan Wang,
Yingying Hu,
Yanling Zhu
Issue:
Volume 15, Issue 3, June 2026
Pages:
125-136
Received:
27 April 2026
Accepted:
4 June 2026
Published:
9 June 2026
DOI:
10.11648/j.earth.20261503.11
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Abstract: Currently, research on persistent organic pollutants in permafrost soils has primarily focused on distribution surveys, with limited studies investigating migration mechanisms. This paper examines the vertical migration processes and driving mechanisms of polycyclic aromatic hydrocarbons (PAHs) in permafrost soils. Given the diverse sources of pollutants under natural conditions and the complex mixture of contaminants typically found in soils, this study selected 16 priority-controlled PAHs as research targets. Using loess soil from Lanzhou—a seasonally frozen region—as the experimental substrate, we conducted indoor soil column leaching experiments under freeze-thaw cycling conditions. This approach simulates the vertical migration of PAHs in permafrost soils, to quantitatively describe PAHs' vertical migration and distribution within soil profiles, along with permafrost layer barrier mechanisms. Simulated soil column experiments combining freeze-thaw cycles and leaching were designed to analyze the driving mechanisms of PAH vertical migration influenced by these processes. The results indicate that the driving mechanism of freeze-thaw cycles primarily involves water migration toward the freeze front due to soil surface freezing, leading to upward migration of pollutants. The driving mechanism of leaching primarily involves vertical migration of dissolved-phase PAH pollutants in soil through leachate. The primary driving force is leaching, while freeze-thaw cycles drive PAHs to migrate upward over greater distances.
Abstract: Currently, research on persistent organic pollutants in permafrost soils has primarily focused on distribution surveys, with limited studies investigating migration mechanisms. This paper examines the vertical migration processes and driving mechanisms of polycyclic aromatic hydrocarbons (PAHs) in permafrost soils. Given the diverse sources of poll...
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