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

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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.