Collaborative Proposal: An Integrated Study Of The Controls On Reactivity Of Natural Organic Matter In Porous Media

对天然有机物质（NOM）与矿物表面相互作用的分子尺度理解将量化高分子量和更多芳香的NOM组分在矿物表面的优先吸附（吸附分馏）如何影响陆地有机碳的转化和污染物通过多孔介质的运输。分子尺度的吸附研究将寻求了解表征土壤孔隙水和浅层地下水中NOM分子量分布的吸附机制，以确定对数正态分布模型是否也适用于地下环境。他们将量化NOM的吸附分馏如何影响痕量金属的结合和迁移性以及NOM的光化学反应性。三个主要目标是：(1)扩大分子尺度的研究，旨在对NOM吸附和分离过程进行更定量和机制的理解；(2)确定吸附分馏对NOM在痕量金属结合方面的反应活性和光反应方面的迁移率的影响；(3)继续整合实验室和实地研究，最终的长期目标是更好地了解实际发生在实地的吸附/分馏现象。该研究在水文科学中具有广泛的意义，因为NOM无处不在，有助于控制矿质土壤团聚体稳定性和光化学反应。至于实际应用，对流域过程控制供水中NOM性质的了解甚少。饮用水工业必须解决消毒剂的问题，使用氯或臭氧，这两种反应性在很大程度上取决于NOM的芳香性。

0106763MauriceThe work to develop molecular-scale understanding of the interactions of natural organic matter (NOM) with mineral surfaces would quantify how the preferential adsorption of higher molecular-weight and more aromatic NOM components to mineral surfaces (sorptive fractionation) affects both the transformation of terrestrial organic carbon and the transport of pollutants through porous media. The molecular-scale adsorption studies would pursue understanding of NOM adsorption mechanisms characterizing NOM molecular weight distributions in soil pore waters and shallow ground waters to determine whether the lognormal distribution model also holds in subsurface environments. They would quantify how sorptive fractionation of NOM affects the binding and mobility of trace metals and NOM photochemical reactivity. The three broad objectives are:(1) To expand molecular-scale studies aimed at developing a more quantitative and mechanistic understanding of NOM adsorption and fractionation processes;(2) To determine the effect of sorptive fractionation on NOM reactivity with respect to trace-metal binding and mobility with respect to photoreactions;(3) To continue to integrate laboratory and field studies, with the ultimate long-term goal of better understanding adsorption/fractionation phenomena as they actually occur in the field. The proposed research has broad significance within the hydrologic sciences, because NOM is ubiquitous and helps to control mineral soil aggregate stability, and photochemical reactions. As to practical applications, little is known about watershed processes controlling the nature of NOM in water supplies. The drinking water industry must address the problem of disinfectant, with chlorine or ozone and both reactivities depend in large part on NOM aromaticity.