Collaborative Research: Do CFCs and SF6 behave as reactive (sorbing) tracers in low carbon content sedimentary aquifers?

合作研究：在低碳含量的沉积含水层中，CFCs和SF6是否表现为活性（吸附）示踪剂？该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。知识优势：氯氟烃和SF6是环境示踪剂，用于测定最近地下水（长达50年）的年代。由于这些化合物是相对可溶的，目前的模式预计这些化合物在有氧、低碳含量（foc）含水层中的保守（不吸附或降解）运输。我们假设CFCs和SF6在许多低碳沉积含水层中起活性（吸收）示踪剂的作用。特别是那些含有热蚀变碳质物质（TACM）的。TACM的例子包括炭、煤和干酪根。TACM普遍存在于泥盆世以来沉积的沉积物中。我们的初步实验表明，CFC的吸附足以显著延缓低焦含水层中CFC的输送。该项目将首次系统评估不同形式的TACM对CFC和SF6吸附的影响。实验将在一个前所未有的~9个数量级的浓度范围内完成。CM将使用既定的方法进行分馏、量化和分类。所推导的等温线模型和参数将用于评估在低焦含水层中这些溶质的显著阻滞的条件。更广泛的影响：拟议的项目将为博士之间的新合作提供支持。Allen-King和Sheldon是纽约州立大学相邻和互补机构的教员：主要是本科生机构Geneseo和博士授予机构Buffalo。此计划将直接资助四名本科生及一名博士生，以增加受教育的机会。它将通过院校之间的学生交流，提供发展联系的机会。计划将邀请符合资格的学生提出申请，并特别注意邀请代表性不足的群体成员参与。通过提高对地下水中中等疏水性化学物质的反应性迁移的理解和改进地下水年龄估算，该项目将为社会带来好处。该项目将通过为研究生提供高薪职位和有价值的培训来支持经济刺激，这些培训将在他们进入劳动力市场时提高他们的技术贡献。

Collaborative Research: Do CFCs and SF6 behave as reactive (sorbing) tracers in low carbon content sedimentary aquifers?This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Intellectual Merit: CFCs and SF6 are environmental tracers used to date recent groundwater (up to ~50 years). Because these compounds are relatively soluble, the current paradigm expects conservative (no sorption or degradation) transport of these compounds in aerobic, low carbon content (foc) aquifers. We posit that CFCs and SF6 act as reactive (sorbing) tracers in many low foc sedimentary aquifers ? in particular those that contain thermally altered carbonaceous matter (TACM). TACM examples include char, coal and kerogen. TACM occurs commonly in sediments deposited since the Devonian. Our preliminary experiments demonstrate that CFC sorption is sufficient to significantly retard CFC transport in low foc aquifers. This project will provide the first systematic assessment of the impact of different forms of TACM on CFC and SF6 sorption. The experiments will be completed for selected low foc sediments over an unprecedented concentration range of ~9 orders of magnitude. CM will be fractionated, quantified and classified using established methods. The isotherm models and parameters deduced will be used to evaluate the conditions in which significant retardation of these solutes are expected in low foc aquifers. Broader Impacts: The proposed project will provide support for a new collaboration between Drs. Allen-King and Sheldon, faculty members at neighboring and complementary SUNY institutions: Geneseo, a primarily undergraduate institution, and Buffalo, a PhD granting institution. This project will enhance educational opportunities through direct support of four undergraduate students and one PhD student. It will provide opportunities to develop connections through student exchanges between the institutions. The PIs will invite applications from qualified students with particular attention to soliciting participation from members of underrepresented groups. Benefit to society from this project will come through improved understanding of the reactive transport of moderately hydrophobic chemicals in groundwater and improved groundwater age estimates. This project will support economic stimulus through providing well paid positions for research students and valuable training that will enhance their technical contributions as they enter the workforce.