Collaborative Research: Dissolved pyrogenic organic matter dynamics in the environment

合作研究：环境中溶解热解有机物动力学

• 批准号: 1451452
• 负责人: Patrick Hatcher
• 金额: $ 17.69万
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1451452&HistoricalAwards=false
• 关键词: Collaborative; Research; Dissolved; pyrogenic; organic

Pyrogenic organic matter, or black carbon (BC), is derived from the incomplete combustion of biomass and fossil fuels. It is now recognized that this type of organic matter has a great impact on soil chemistry, transport of pollutants, climate and global carbon cycling. Further, its impacts will likely grow due to increased climate change-related wildfires and intentional addition of BC (as biochar) to soils to enhance soil fertility and carbon sequestration. However, while knowledge of the properties of natural and anthropogenic particulate BC has increased in recent years, there has been relatively little study of the properties and cycling of the organic matter that can leach from BC; pyrogenic dissolved organic matter (py-DOM). Although release of py-DOM into the environment may have unrecognized carbon cycling and environmental impacts, py-DOM has been quantified in only a few systems using methods that have not been comprehensively evaluated. This research will examine the fundamental chemical properties and mechanisms associated with py-DOM production and fate and the chemical markers used to quantify it. In addition, in order to broaden general awareness of the importance of fire on climate and the carbon cycle, the investigators will develop an interactive exhibit at a local hands-on science museum that will include touch screen graphics, narrated videos by each of the principal investigators illustrating the scientific process and the research results. To establish the chemical properties and mechanisms associated with py-DOM production and fate and the chemical markers used to quantify it, the project will: 1) produce py-DOM from a logical series of BC solids, both freshly produced and "aged" via microbial and photic treatments, 2) chemically characterize these BC parent solids and their aqueous dissolved products using FTIR, Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and 1- and 2-dimensional NMR, 3) examine py-DOM loss and transformation after microbial and photodegradation treatments, and 4) quantify the yields of putative pyrogenic molecular markers; levoglucosan, benzenepolycarboxylic acids (BPCA) and oxygenated polycyclic aromatic hydrocarbons (O-PAH), from fresh and "aged" BC solids and leachates. Using the same methods and experiments, the leachates and leachate alteration products of potentially interfering non-pyrogenic terrestrial organic materials, some of which the investigators have recently shown to contain "BC-like" compounds will also be examined. This work will test whether py-DOM chemistry can be linked to its parent BC type and "aging" processes, the extent to which py-DOM and its molecular markers undergo major losses and chemical transformation through microbial and photo-oxidation, and whether currently used molecular markers for py-DOM accurately represent actual pyrogenic OM contributions to environmental samples.

热解有机物，或黑碳（BC），来自生物质和化石燃料的不完全燃烧。现在人们认识到，这种类型的有机物对土壤化学、污染物的迁移、气候和全球碳循环有很大的影响。此外，由于与气候变化有关的野火增加以及有意向土壤中添加BC（作为生物炭）以提高土壤肥力和碳固存，其影响可能会增加。然而，虽然近年来对自然和人为颗粒BC的性质的了解有所增加，但对可从BC中沥滤的有机物的性质和循环的研究相对较少;热解溶解有机物（py-DOM）。虽然释放到环境中的py-DOM可能有未被认识到的碳循环和环境影响，py-DOM已经量化，只有在少数系统中使用的方法，尚未得到全面评估。这项研究将检查与py-DOM的产生和归宿相关的基本化学性质和机制，以及用于量化它的化学标记物。此外，为了扩大对火灾对气候和碳循环重要性的普遍认识，研究人员将在当地的动手科学博物馆开发一个互动展览，其中包括触摸屏图形，每个主要研究人员都有解说视频，说明科学过程和研究结果。为了确定与py-DOM产生和归宿有关的化学特性和机制以及用于量化的化学标志物，该项目将：1）通过微生物和光处理从逻辑系列的BC固体（新鲜产生的和“老化的”BC固体）产生py-DOM，傅里叶变换离子回旋共振质谱（FTICR-MS）和一维和二维NMR，3）检查在微生物和光降解处理之后py-DOM损失和转化，以及4）量化推定的热原分子标记的产量;从新鲜和“老化”BC固体和沥滤液中提取的左旋葡聚糖、苯多羧酸（BPCA）和氧化多环芳烃（O-PAH）。还将使用同样的方法和实验，对可能产生干扰的非热原陆地有机物质的沥滤物和沥滤物蚀变产物进行检查，其中一些物质最近被调查人员发现含有“类溴化碳”化合物。这项工作将测试py-DOM化学是否可以链接到其母公司BC类型和“老化”过程，在何种程度上py-DOM和它的分子标记物通过微生物和光氧化进行重大损失和化学转化，以及目前使用的分子标记物py-DOM是否准确地代表实际的热原OM环境样品的贡献。