Melting snowpack can release semi-volatile organic compounds (SVOCs) to both terrestrial and aquatic ecosystems, resulting in high ecological risk. The dynamics of polycyclic aromatic hydrocarbon (PAH) released from snowpack under laboratory (intense melting) and field (melt/freeze melyting) snowmelt experiments was investigated in this study. In the laboratory: dissolved organic carbon (DOC) controlled the first flush of dissolved PAH released from snowpack, except for napthelene, which is also affected by its solubility. The particles released early from snowpack usually contained high PAH concentrations (more than 100 μg g−1) and those released at the end contained low PAH concentrations (<20 μg g−1). The total PAH release pattern was determined by composition of all PAH, including type 2 enrichment with a final peak and type 4 enrichment with double-peak. In field melting: all dissolved PAHs were released constantly, except naphthalene which also showed a first flush but to a lesser extent. DOC controlled the release pattern of all detected dissolved PAHs from snowpack. High PAH concentrations were observed in particles released from snowpack at both the beginning and the end of the melting event. Concentrations of both total PAHs and PAH compositions in meltwater showed an increasing trend with melting time (from 1.3 to 4.0 μg L−1 and from 1.7 to 5.3 μg L−1 in meltwater from each of the two snowpack), which coincided with Type 3 enrichment. Overall, our results suggest intense melting resulted in the shift of some hydrophobic PAH compositions from Type 2 to Type 4 enrichment. In contrast, melting with melt/freeze cycles may cause the shift of PAHs from Type 2 to Type 3 enrichment. Our study indicates changes to the melting scenarios due to global warming could affect dynamics of SVOCs released from snowpack, which is useful for risk management for water and soil quality.

中文翻译：

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融化情景影响积雪释放的多环芳烃的动力学

融化的积雪会向陆地和水生生态系统释放半挥发性有机化合物 (SVOC)，从而导致高生态风险。本研究研究了在实验室（强烈融化）和现场（融化/冻结融化）融雪实验下从积雪释放的多环芳烃（PAH）的动力学。在实验室中：溶解有机碳 (DOC) 控制着从积雪中释放出的溶解多环芳烃的第一次冲洗，但萘酚除外，它也受其溶解度的影响。积雪早期释放的颗粒通常含有高浓度的 PAH（超过 100 μg g-1），而最终释放的颗粒含有低浓度的 PAH（<20 μg g-1）。总多环芳烃释放模式由所有多环芳烃的组成决定，包括具有最终峰的类型 2 富集和具有双峰的类型 4 富集。现场熔化：所有溶解的多环芳烃不断释放，除了萘也显示出第一次冲洗但程度较小。DOC 控制积雪中所有检测到的溶解多环芳烃的释放模式。在融化事件的开始和结束时，从积雪释放的颗粒中都观察到高 PAH 浓度。融水中的总多环芳烃和多环芳烃组成的浓度随着融化时间显示出增加的趋势（来自两个积雪中的每一个的融水中从 1.3 到 4.0 μg L-1 和从 1.7 到 5.3 μg L-1），这与类型 3 一致丰富。总的来说，我们的结果表明强烈的熔化导致一些疏水性多环芳烃组合物从 2 型富集转变为 4 型富集。相比之下，用熔化/冷冻循环熔化可能会导致 PAH 从 2 型富集转变为 3 型富集。我们的研究表明，由于全球变暖导致的融化情景的变化可能会影响积雪释放的 SVOC 的动态，这对于水和土壤质量的风险管理很有用。