Collaborative Research: Characterizing Biodegradable and Recalcitrant Distillates used during Hydraulic Fracturing: Rates, Risks, and Microbial Metabolic Processes

CBET 1336326/1336702保拉·穆萨/德西里·普拉塔俄亥俄州立大学/杜克大学水平钻井和水力压裂技术的进步最近使从煤层和甲烷页岩地层中提取大量能源成为可能。目前，页岩能源开发的速度超过了监管政策和对这些技术潜在环境和健康影响的研究。公众关注的问题包括由于压裂和返排液处理不当（例如钻孔泄漏、地表溢出）而可能对饮用水资源造成的污染，以及在深层地下仍未回收的注入液的命运。该研究项目的目的是确定水力压裂过程中使用的选定芳香族和脂肪族化合物的生物降解率，以便更好地确定在自然含水层条件下可能对生态或人类健康构成风险的可降解或不可降解成分。选定的化学品类别代表了水力压裂液添加剂中经常使用的潜在有毒化合物，这些化合物通常未被化学品制造商公开。为了实现这一目标，研究人员将表征代表性压裂液中存在的低分子量和高分子量芳香族和脂肪族馏分，并使用高分辨率分析技术识别风险成分的子集，包括气相色谱（GC）与火焰离子化检测，GC质谱和多维GC。实验室实验采用土著微生物种群和选择细菌分离株将进行调查化学成分是如何在一系列的物理和化学条件下生物降解代表浅淡水含水层，更深的盐基岩，页岩地层的压力和温度。将使用高通量生物技术工具监测微生物动力学，包括16 S rRNA基因的热测序，这使得可以在广泛的生物物种之间进行比较。研究结果将被用来制定一个风险矩阵，概述存在或不存在潜在的有毒有机成分沿着压力，温度和盐度谱。可降解组分和微生物之间的联系将为理解压裂液中馏分化合物生物转化的特定微生物代谢机制提供起点。该项目将显著提高我们对压裂液馏分如何被土著微生物生物降解的理解，并将确定可能限制或增强压裂液中高风险化合物降解的关键理化因素。环境这项研究的成果包括更好地量化生物降解率和更好地参数化这些系统的流动和运输模型。它还将进一步深入了解化合物的持久性，以改善环境友好型钻井作业中的化学地层。研究结果将通过EnergyExplained传达给学生和更广泛的公众！讲座，强调天然气和可再生技术的稀缺性，安全性，可行性和环境影响等问题，在各种当地场所（图书馆，博物馆和/或小学）。调查人员还将通过由俄亥俄州州立大学领导的定期研讨会和专家会议，向阿巴拉契亚地区的非营利组织、监管机构、学者和其他利益相关者传播有关页岩能源关键问题的知识。地下能源资源中心和推广办公室。

CBET 1336326/1336702Paula Mouser/ Desiree PlataOhio State University/Duke UniversityAdvancements in horizontal drilling and hydraulic fracturing techniques have recently made it possible to extract large volumes of energy resources from coal bed and methane shale formations. Currently, shale energy development is occurring at a rate that is outpacing both regulatory policies and research on the potential environmental and health effects of these techniques. Public concerns include the potential contamination of drinking water resources through the mishandling of fracturing and flowback fluids (e.g. borehole leaks, surface spills), as well as the fate of injected fluids that remain unrecovered in the deep subsurface. The objective of the research project is to determine biodegradation rates for select aromatic and aliphatic compounds that are used during the hydraulic fracturing process in order to better define the degradable or recalcitrant constituents that may pose risk to ecological or human health under natural aquifer conditions. The select chemical classes represent frequently used, potentially toxic compounds that are often undisclosed by chemical manufacturers in hydraulic fracture fluid additives. To realize this objective, the investigators will characterize low and high molecular weight aromatic and aliphatic distillates present in a representative fracturing fluid and identify a subset of risk constituents using high resolution analytical techniques, including gas chromatography (GC) with flame ionization detection, GC mass spectrometry, and multi-dimensional GC. Laboratory experiments employing indigenous microbial populations and select bacterial isolates will be performed to investigate how chemical constituents are biologically degraded across a range of physical and chemical conditions representative of shallow freshwater aquifers, deeper saline bedrock, and shale formation pressures and temperatures. Microbial dynamics will be monitored using high-throughput biotechnology tools, including pyroseqeuncing of the 16S rRNA gene, which allows comparison across a broad range of biological species. Research findings will be used to develop a risk matrix that outlines the presence or absence of potentially toxic organic constituents along a pressure, temperature, and salinity spectrum. Associations between degradable constituents and microorganisms will provide a starting point for understanding the specific microbial metabolic mechanisms responsible for distillate compound biotransformation in fracturing fluids.The project will significantly improve our understanding of how fracturing fluid distillates are biodegraded by indigenous microorganisms and will identify the key physicochemical factors that may limit or enhance the degradation of higher risk compounds in the environment. Outcomes from this research include better quantification of biodegradation rates and better parameterization of flow and transport models of these systems. It will also provide further insight into the persistence of compounds in order to improve chemical formations in environmentally friendly drilling operations. Research findings will be communicated to students and the broader public through EnergyExplained! lectures, highlighting such issues as scarcity, security, feasibility, and environmental impacts from natural gas and renewable technologies at a variety of local venues (libraries, museum, and/or grade schools). Investigators will also disseminate knowledge on key shale energy issues to non-profits, regulatory agencies, academics, and other stakeholders in the Appalachian region through regular workshops and workgroup meetings led by Ohio State University?s Subsurface Energy Resource Center and Extension Office.