Helmholtz Center for Environmental Research-UFZ, Department of Environmental Engineering, Permoserstr. 15, 04318 Leipzig, Germany.
Helmholtz Center for Environmental Research-UFZ, Department of Lake Research, Brueckstr. 3a, 39114 Magdeburg, Germany.
Sci Total Environ. 2017 Feb 1;578:219-227. doi: 10.1016/j.scitotenv.2016.01.116. Epub 2016 Feb 1.
Natural neutralization of acidic mining lakes is often limited by organic matter. The knowledge of the sources and degradability of organic matter is crucial for understanding alkalinity generation in these lakes. Sediments collected at different depths (surface sediment layer from 0 to 1 cm and deep sediment layer from 4 to 5cm) from an acidic mining lake were studied in order to characterize sedimentary organic matter based on neutral signature markers. Samples were exhaustively extracted, subjected to pre-chromatographic derivatizations and analyzed by GC/MS. Herein, molecular distributions of diagnostic alkanes/alkenes, terpenes/terpenoids, polycyclic aromatic hydrocarbons, aliphatic alcohols and ketones, sterols, and hopanes/hopanoids were addressed. Characterization of the contribution of natural vs. anthropogenic sources to the sedimentary organic matter in these extreme environments was then possible based on these distributions. With the exception of polycyclic aromatic hydrocarbons, combined concentrations across all marker classes proved higher in the surface sediment layer as compared to those in the deep sediment layer. Alkane and aliphatic alcohol distributions pointed to predominantly allochthonous over autochthonous contribution to sedimentary organic matter. Sterol patterns were dominated by phytosterols of terrestrial plants including stigmasterol and β-sitosterol. Hopanoid markers with the ββ-biohopanoid "biological" configuration were more abundant in the surface sediment layer, which pointed to higher bacterial activity. The pattern of polycyclic aromatic hydrocarbons pointed to prevailing anthropogenic input. Pyrolytic makers were likely to due to atmospheric deposition from a nearby former coal combustion facility. The combined analysis of the array of biomarkers provided new insights into the sources and transformations of organic matter in lake sediments.
自然中和酸性矿山湖通常受到有机物的限制。了解有机物的来源和可降解性对于理解这些湖泊的碱度生成至关重要。为了根据中性特征标志物来描述沉积物中的有机物质，对取自酸性矿山湖不同深度（表层沉积物 0-1cm 和深层沉积物 4-5cm）的沉积物进行了研究。样品经过充分提取，进行预色谱衍生化处理，然后通过 GC/MS 进行分析。本文讨论了诊断烷烃/烯烃、萜烯/萜类、多环芳烃、脂肪醇和酮、甾醇以及藿烷/藿烷类的分子分布。然后，基于这些分布，有可能对这些极端环境中沉积物有机物质的天然和人为来源的贡献进行特征描述。除了多环芳烃外，所有标志物类别在表层沉积物中的综合浓度均高于深层沉积物。烷烃和脂肪醇的分布表明，沉积物中的有机物质主要来自异源，而非自源。甾醇模式主要由陆地植物的植物甾醇主导，包括豆甾醇和β-谷甾醇。ββ-生物藿烷“生物”构型的藿烷标志物在表层沉积物中更为丰富，这表明细菌活性更高。多环芳烃的模式表明存在主要的人为输入。热解标志物可能是由于附近以前的燃煤设施的大气沉积。一系列生物标志物的综合分析为湖泊沉积物中有机物的来源和转化提供了新的见解。
