Geochemical Controls on the Adsorption, Bioavailability, and Environment

对吸附、生物利用度和环境的地球化学控制

• 批准号: 7792423
• 负责人: Stephen A. Boyd
• 金额: $ 37.54万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7792423
• 关键词: Adjuvant; Adsorption; Affect; Area; Bacteria; Basic Science; Biodegradation; Biological Availability; Biological Process; Biosensor; Blood capillaries; Cations; Cells; Chemicals; Chemotaxis; Dioxins; Environment; Fluorescence; Genes; Genome; Genomics; Green Fluorescent Proteins; Immobilization; Individual; Ingestion; Lead; Ligands; Link; Literature; Mammals; Measures; Methods; Microbe; Microbial Genetics; Minerals; Mission; Molecular; Mus; Optics; Organism; Oxygenases; Phase; Physical condensation; Play; Poison; Polychlorinated Biphenyls; Population; Process; Property; Public Health; Reporter; Research; Research Training; Risk Assessment; Role; Route; Soil; Solutions; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis; Superfund; Surface; System; Techniques; Toxic effect; Training Programs; Water; Work; aqueous; capillary; clay; dibenzofuran; enthalpy; exposed human population; microbial; microorganism interaction; organic contaminant; remediation; response; simulation; superfund chemical; superfund site; ultraviolet; water solubility

Our objectives are to characterize poorly understood mechanistic processes that control sorption of Ahreceptor ligands (AhRLs) to mineral surfaces, and then use these well-defined systems to probe the bioavailability of sorbed AhRLs to bacteria and mammals. Since AhRLs tend to have exceptionally low water solubilities, these highly toxic compounds exist in the environment predominantly as sorbed species. We argue that clay minerals are a major, largely unrecognized sink for AhRLs in the environment. Our preliminary studies and the literature suggest that clays may play a nearly equal or even dominant role to that of organic matter in the immobilization of dioxins in soils. Our proposal has four specific aims: 1) To measure sorption and sequestration of key AhRLs to clay minerals and to characterize the geochemical controls on that sorption, 2) To determine the molecular mechanisms of such sorption through integrating bulk results with spectroscopy and molecular simulation studies, thereby promoting more rational long-term Superfund site stewardship, 3) To identify microbial genetic and functional responses to minerals themselves and to mineral-adsorbed AhRLs in order to elucidate key mechanisms of microbial interaction with these adsorbed compounds, and 4) To quantify the microbial functionality enabling bioavailability and biodegradation of mineral-sorbed AhRLs by using fluorescent markers that are expressed with key microbial responses. Thus our proposal supports the mission of the Superfund Basic Research and Training Program because in Objective 1 we will work to "identify and quantify chemical forms of the contaminants," in Objectives 1-2 we will assess "the physical, chemical and biological processes affecting chemicals in environmental media," and in Objectives 3-4 we will link this work directly to bioavailability of Superfund chemicals to bacteria and to mammals. Relevance of this research to public health: Many toxic organic contaminants are so insoluble in water that the main route of human exposure is through ingestion of adsorbed contaminants. We propose to characterize adsorption of dioxins and related compounds to clay minerals, and then use both bulk and molecular methods to understand the effects of adsorption on the toxicity of the compound (to mice) and the biodegradation of the compound (by soil bacteria), which is needed in remediation and risk assessment.

我们的目标是表征控制AHREPERTOR吸附的机械过程不足 配体（AHRL）到矿物表面，然后使用这些定义明确的系统探测 吸附的AHRL对细菌和哺乳动物的生物利用度。由于AHRL往往具有极低的水 溶解度，这些剧毒化合物主要存在于环境中，主要是吸附物种。我们 认为粘土矿物是环境中AHRL的主要，在很大程度上无法识别的水槽。我们的 初步研究和文献表明，粘土在 二恶英在土壤中固定的有机物。我们的建议有四个具体的目标：1） 测量关键AHRL对粘土矿物质的吸附和隔离，并表征地球化学 对该吸附的控制，2）通过整合确定这种吸附的分子机制 通过光谱和分子模拟研究进行大量结果，从而促进了更多的理性长期 超级基金站点管理，3）确定对矿物质本身的微生物遗传和功能反应 并为了阐明与这些微生物相互作用的关键机制 吸附化合物，4）量化可实现生物利用度和的微生物功能 使用用关键微生物表达的荧光标记对矿物质的AHRL的生物降解 回答。因此，我们的建议支持超级基础研究和培训计划的使命 因为在目标1中，我们将努力“识别和量化污染物的化学形式” 目标1-2我们将评估“影响化学物质的物理，化学和生物学过程 环境媒体，“在目标3-4中，我们将把这项工作直接链接到超级基金的生物利用度 化学物质到细菌和哺乳动物。这项研究与公共卫生的相关性：许多有毒的有机污染物在水中是如此不溶于水，以至于人类接触的主要途径是通过摄入吸附的污染物。我们建议表征二恶英和相关化合物对粘土矿物的吸附，然后同时使用大量和 理解吸附对化合物（小鼠）毒性的影响的分子方法 化合物（通过土壤细菌）的生物降解，这是补救和风险评估所需的。