RAPID: Computation of accurate binding energies of emerging organic contaminants on environmental and infrastructural interfaces

2014年1月9日，西弗吉尼亚州查尔斯顿的自由工业公司意外地从他们的储罐中排放了大约1万加仑的化学品，其中包括4-甲基环己烯乙醇（MCHM），其中未知部分随后流入埃尔克河。1月21日星期二，据披露，“泄漏液体”中也含有约7.3%的乙二醇醚（PPh；丙二醇苯基醚）。在有人被告知化学物质泄漏之前，它已经发生在查尔斯顿西弗吉尼亚州美国水务公司主要水源的入口处。在发现污染后，该州对西弗吉尼亚州9个县的30万人发布了“禁止使用令”。“禁止使用令”指的是不能喝这些水，也不能用这些水洗澡、淋浴、做饭或洗衣服！从本质上讲，水的全部作用就是冲厕所。在接下来的两个星期里，受影响地区的居民收到了州政府、环境保护部、西弗吉尼亚州美国水务公司和自由工业公司发出的相互矛盾的命令和大量信息缺口。该项目旨在研究量子化学计算方法，以提供所有主要原油MCHM和PPh（一种化学物质，直到化学物质释放1.5周后才被披露在泄漏中）成分的结合能，并使用简单的聚合物表面模型（即PVC和PE），在淤泥和粘土中普遍存在的环境界面（即硅酸盐和碳酸盐），水处理过滤中使用的材料（二氧化硅和碳）。利用我国现有的高性能计算资源，可以根据需要获得有关新出现污染物特定结合行为的高精度信息。唯一的要求是一个经过良好验证的模型和获得此信息所需的特定计算知识。我们的目标是建立这些模型。我们将：1)建立和测试有用的二氧化硅、方解石、聚合物簇、活性炭和/或其他释放化合物可能吸附的相关表面的化学模型；2)确定先前建立的有机污染物的结合能（用现有的实验数据校准我们的模型）和粗糙的MCHM和PPh与表面模型；3)研究和确定更快、更便宜的计算方法，与校准数据相比，这些方法可以提供可接受的精度；4)检验处理溶剂化和构象复杂性对结合能计算准确性的重要性。这项RAPID拨款将为开发模型奠定基础，以准确和预测性地确定具有环境和基础设施重要性表面的未来新出现污染物的结合能。我们的方法将提供给公共领域，并将允许应急响应人员获得这些污染物行为的按需和实时估计，并可以帮助在未来事件中及时指导地面补救或预防策略。

Alexander1435289On January 9, 2014, Freedom Industries in Charleston, West Virginia accidentally discharged approximately 10,000 gallons of chemicals, including 4-methylcyclohexanemethanol (MCHM), from their storage tanks, an unknown portion of which then flowed into the Elk River. On Tuesday, January 21, it was disclosed that about 7.3 % glycol ether (known a PPh; propylene glycol phenyl ether) was in the "leaked fluids," as well. Before anyone was notified of the chemical spill, it was at the intake of the main water source for West Virginia American Water in Charleston. After discovering the contamination, the State issued "A Do Not Use Order" for 300,000 people in 9 counties of West Virginia. A "Do Not Use Order" means not to drink the water, and not to use the water for bathing or showering, cooking or clothes washing! Essentially, all that the water is good for is flushing the toilet. Over the next two weeks, residents of the affected areas were presented with conflicting orders and large gaps in information by the State government, The Department of Environmental Protection, West Virginia American Water, and Freedom Industries.This proposed project aims to investigate quantum chemical computational methods to provide binding energies of all the major crude MCHM and PPh ( a chemical that was not disclosed as present in the spill until 1.5 weeks after the chemical release) components with simple models of polymer surfaces used in domestic water systems (i.e. PVC and PE), environmental interfaces prevalent in silts and clays (i.e. silicates and carbonates), and materials used within water processing filtration (silica and carbon). With the high-performance computing resources available to our Nation, high-accuracy information about specific binding behavior of emerging contaminants can be obtained essentially on-demand. The only requirement is a well-validated model and knowledge of the particular calculations needed to obtain this information. Our goal is to build these models.We will:1) Build and test useful chemical models of silica, calcite, polymer clusters, activated charcoal, and/or other relevant surfaces where the released compounds may adsorb;2) Determine binding energies of previously established organic contaminants (to calibrate our models with extant experimental data) and crude MCHM and PPh with the surface models;3) Investigate and identify faster and cheaper computational methods which give acceptable accuracy when compared to calibrated data;4) Examine the importance of treating solvation and conformational complexity on the accuracy of binding energy calculations.This RAPID grant will lay the foundation for development of models for accurate and predictive determination of binding energies of future emerging contaminants with surfaces of environmental and infrastructural importance. Our methods will be made available to the public domain and will allow emergency responders to obtain on-demand and on-the-fly estimates of the behavior of these contaminants and can help direct remediation or prevention strategies on the ground in a timely manner in future incidents.