Reducing Properties of Anaerobic Sediments: Molecular Probe Studies of Biogeochemistry and Contaminant Fate

厌氧沉积物的还原特性：生物地球化学和污染物归宿的分子探针研究

• 批准号: 9708554
• 负责人: Paul Tratnyek
• 金额: $ 29万
• 依托单位: Oregon Graduate Institute of Science & Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9708554&HistoricalAwards=false
• 关键词: Reducing; Properties; Anaerobic; Sediments; Molecular

This award in the Environmental Geochemistry and Biogeochemistry Program is made to Drs. Paul G. Tratnyek, V. Renganathan, and David R. Boone of the Department of Environmental Science and Engineering, Oregon Graduate Institute, for studies of contaminant fate in anaerobic sediments. The research is supported by the Divisions of Chemistry and Earth Sciences and the MPS Office of Multidisciplinary Activities. Some contaminants undergo reduction in anaerobic soils, but the biochemical and geochemical factors controlling the chemical reaction are not well understood. The goal of this research is to develop molecular probes that can elucidate reduction processes in sediments from coastal, estuarine, and freshwater environments. Initial work will use 2-chloroacetophenone (2-CAP) to monitor the reduction process. This chemical is reduced to 2-(chloromethyl)benzyl alcohol when it reacts by electron transfer, and to acetophenone when reduced by hydride transfer. By measuring the amount of each of these three compounds present in the sediment, the rate of reduction and the capacity of the soil for reduction will be determined. The formation of acetophenone implies reaction with extracellular nicotinamide, one of the few possible sources of hydride in such systems. Results will be correlated with microbiological studies to develop a model of the biogeochemical reduction process in various soils. Additional molecular probes will be studied as means of more fully characterizing the reducing capacity of real environmental materials. Pollutants such as chlorohydrocarbons, sulfoxides, and quinones can be transformed in soils by chemical reactions in which electrons are added to the contaminant from environmental sources, both organic and inorganic. The details about how these reactions occur as well as the rates and extent to which they occur in various types of soils are not sufficiently understood to predict contaminant fate in the environment. In this research a general method to test the environmental relevance of various models will be developed with the long-term goal of providing a predictive tool useful to regulatory decision-making.

环境地球化学和生物地球化学计划的该奖项授予博士。俄勒冈研究生院环境科学与工程系的 Paul G. Tratnyek、V. Renganathan 和 David R. Boone，研究厌氧沉积物中的污染物归宿。 该研究得到了化学和地球科学司以及公安部多学科活动办公室的支持。 一些污染物在厌氧土壤中发生还原，但控制化学反应的生化和地球化学因素尚不清楚。 这项研究的目标是开发分子探针，阐明沿海、河口和淡水环境沉积物的还原过程。 初步工作将使用 2-氯苯乙酮 (2-CAP) 来监测还原过程。 该化学物质通过电子转移反应时被还原为 2-(氯甲基)苯甲醇，通过氢化物转移反应时被还原为苯乙酮。 通过测量沉积物中这三种化合物的含量，可以确定还原速率和土壤的还原能力。 苯乙酮的形成意味着与细胞外烟酰胺的反应，烟酰胺是此类系统中少数可能的氢化物来源之一。 结果将与微生物研究相关联，以开发各种土壤中生物地球化学还原过程的模型。 将研究其他分子探针，作为更全面地表征真实环境材料的还原能力的手段。 氯代烃、亚砜和醌等污染物可以通过化学反应在土壤中转化，其中电子被添加到来自环境来源（有机和无机）的污染物中。 关于这些反应如何发生以及它们在各种类型土壤中发生的速率和程度的细节尚未得到充分了解，无法预测环境中污染物的命运。 在这项研究中，将开发一种测试各种模型的环境相关性的通用方法，其长期目标是提供对监管决策有用的预测工具。