Isotope Biogeochemistry of Polycyclic Aromatic Hydrocarbons in Riverine Sediments (With Application to St. Lawrence and Hudson River)

河流沉积物中多环芳烃(PAH)和其他与颗粒有关的有机污染物的分子和稳定同位素组成(C和H)反映了(1)污染源的性质，(2)运输过程中的生物和非生物转化，(3)颗粒组合和来源混合的动力学，(4)沉积历史和(5)沉积后成岩反应的综合作用。影响大型河流系统中与颗粒相关的有机污染物的可能来源和过程的多样性，要求对污染物的分子和同位素化学的具体过程或来源有完整的了解。这反过来又需要多种水文地球化学载体的可用性，这些载体能够唯一地识别或严重限制特定的污染源和/或路径。我们的主要目标是加强现有的方法来评估地表水系统中与颗粒相关的有机污染物的来源和归宿。我们将重点发展化合物特有的13C/12C和分子有机测量。这项拟议的工作将考察D/H比的来源辨别潜力以及涉及碳氢化合物的D/H特定转化反应。具体地说，将在一系列预期的近地表条件下考察挥发、光降解、吸附和生物降解对单个多环芳烃化合物D/H比的影响。拟议的研究还将探讨D/H技术在阐明圣劳伦斯河(SLR)和哈德逊河(HR)盆地沉积物中多环芳烃的来源和去向方面的效用。这些系统例证了该区域和其他地方自然和人为碳氢化合物来源的多样性，人类对这两条河流的长期使用提供了一些最广泛的人为碳氢化合物沉积和储存在河流沉积物中的记录。

0073912AbrajanoThe molecular and stable isotopic compositions (C and H) of polycyclic aromatic hydrocarbons (PAH) and other particle-associated organic contaminants in riverine sediments reflect the combined effects of the (1) nature of contaminant sources, (2) biotic and abiotic transformation during transport, (3) dynamics of particle association and source mixing, (4) depositional history and (5) post-depositional diagenetic reactions. This multiplicity of possible sources and processes affecting particle-associated organic contaminants in large river systems requires a complete understanding of specific processes or sources on the molecular and isotopic chemistry of the contaminant. This in turn requires the availability of multiple hydrogeochemical vectors that are able to uniquely identify or seriously constrain specific contaminant sources and/or pathways.Our primary goal is to enhance existing approaches to evaluating the sources and fate of particle-associated organic contaminants in surface water systems. We will focus on the development of compound-specific 13C/12C and molecular organic measurements. The proposed work will examine the source discrimination potential of D/H ratios as well as D/H-specific transformation reactions involving hydrocarbons.Specifically, the impact of volatilization, photodegradation, sorption, and biodegradation on the D/H ratios of individual PAH compounds will be examined under a range of expected near-surface conditions. The proposed research will also examine the utility of the D/H technique for elucidating the sources and fate of PAH in the sediments of the St. Lawrence River (SLR) and Hudson River (HR) basins. These systems exemplify the multiplicity of natural and anthropogenic hydrocarbon sources in this region and elsewhere, and the long history of human use of these two rivers offers some of the most extensive records of anthropogenic hydrocarbon deposition and storage in river sediments.