EAGER: Engineering Microbial Mats for the On-Site Treatment of Wastewater from Unconventional Gas Production

该项目旨在开发一种新型的、现场的、低成本的处理机制，通过工程微生物垫来处理非常规天然气开采过程中产生的废水。非常规天然气钻井作业产生的废水，被称为产出废水，既含有辅助气体提取的添加剂，也含有极高水平的总溶解固体（TDS），最初来自地下地层。非常规天然气生产方法产生的废水具有独特的特性，这使得废水的处理和处置成为目前尚未解决的重大技术挑战。微生物席是一种聚集和分层的细菌联合体，具有复杂的内部化学和能量梯度以及高度多样化的专门微生物代谢。微生物垫的特点，即高盐胁迫耐受性，促进运输和去除的固定性质，以及多种污染物去除机制，即生物诱导沉淀，矿化或生物吸附，表明它们在处理生产废水方面的用途。该技术的目标是充分处理产出废水，以便在压裂作业中重复使用，保护水资源免受过度开采，并将处置的影响降至最低。为了重复利用产出废水，钻井人员主要关注可能导致结垢或污染井的成分，即钡、锶、铁和生物污染。此外，钻井人员还担心自然发生的放射性物质的积累（规范）。所有现有数据都表明，微生物垫是一种成功的处理方案，可从生产废水中去除有关成分；然而，微生物垫处理生产废水的应用是全新的，这项工作将有助于证明其可行性和潜力。非常规天然气生产，通常被称为水力压裂法。对于水力压裂，使用新技术来获取以前无法进入的地质构造中的天然气。成本效益高的国内天然气生产在美国各行各业都具有显著的经济效益。然而，水力压裂过程中产生的废水的管理，称为？生产废水?，是目前尚未解决的技术难题。生产废水的含盐量大约是海水的五倍，每口井产生200万至400万加仑的废水。现有技术无法经济有效地处理这种含盐量和体积。该项目将研究一种新的现场处理技术——微生物垫，用于在未来水力压裂作业中重复使用之前处理生产废水。微生物垫代表了一种新的处理技术，它需要最少的能量投入和维护，并且可以在现场部署，以消除与卡车运输大量水进行处理相关的影响。

CBET 1353858BibbyUniversity of PittsburghThe proposed project proposal seeks to develop a novel, on-site, and low cost treatment mechanism for wastewaters produced during unconventional gas operations by engineering microbial mats. Wastewaters produced by unconventional gas drilling operations, termed produced wastewaters, contain both additives to assist in gas extraction and extremely high levels of total dissolved solids (TDS) originally derived from subsurface formations. The unique characteristics of wastewaters from unconventional gas production methods make treatment and disposal of this waste stream a significant and currently unsolved technical challenge. Microbial mats are agglomerated and layered bacterial consortia with complex internal chemical and energetic gradients and a high diversity of specialized microbial metabolisms. The characteristics of microbial mats, namely high salt stress tolerance, fixed nature facilitating transport and removal, and multiple mechanisms of contaminant removal, i.e. biologically induced precipitation, mineralization, or biosorption, suggest their utility in treatment of produced wastewaters. The goal of this technology is to treat produced wastewater well enough for reuse in fracturing operations, protecting water resources from over exploitation and minimizing the impacts of disposal. In order to reuse produced wastewater, drillers are primarily concerned with constituents that may cause scaling or foul a well, namely barium, strontium, iron, and biological fouling. Additionally, drillers are concerned about the accumulation of naturally occurring radioactive material (NORMs). All available data suggest microbial mats as a successful treatment scheme for removing constituents of concern from produced wastewaters; however, the application of microbial mats for the treatment of produced wastewaters is entirely novel and this work will serve to demonstrate both its feasibility and potential.Unconventional gas production, often termed ?fracking? for hydraulic fracturing, uses new technology to access gas trapped in geological formations that were previously inaccessible. The cost effective, domestic production of natural gas has significant economic benefits in a wide range of US industries. However, the management of wastewaters produced during hydraulic fracturing, termed ?produced wastewaters?, is a currently unsolved technical challenge. The salt content of produced wastewater is approximately five times that of ocean water and each well produces 2-4 million gallons of wastewater. Existing technologies are unable to cost effectively cope with this salt content and volume. This project will investigate a novel on-site treatment technology, microbial mats, for the treatment of produced wastewaters prior to reuse in future hydraulic fracturing operations. Microbial mats represent a novel treatment technology that would require minimal energy input and maintenance, and could be deployed onsite to eliminate the impacts associated with trucking large volumes of water for treatment.