Geochemical Controls on Hazardous Element Mobilization in Shales and Precipitation in Wastewater Treatment

Princeton University, Princeton NJ

Investigators

Abstract

1438278 Peters Geochemical controls on hazardous element mobilization in shales and precipitation in wastewater treatment Unconventional gas production, that is hydraulic fracturing or "fracking", holds the potential of making the US energy positive. However, during the fracking process it is possible to produce vast quantities of flow-back and production wastewaters. Flow-back water results from the fracking process itself where some of that water may return to the surface, and is known as flow-back water. It is also possible that water that has been in the shale formation may also come back to the surface and is referred to as produced water. In both cases one of the fears is that this water may contaminate either or both subsurface and surface waters. This project will study the chemistry of these waters to help inform others on the potential of environmental degradation. Also, as part of this project, through educational and outreach activities centered on the topics of energy and the environment, another goal is to inspire and excite young people about science and engineering in the context of relevant contemporary issues, and to instill confidence for academic achievement. Through a partnership with Princeton University's PACE Center, an educational program will be developed for middle-school children at Princeton's Community House, a program that seeks to close the minority achievement gap in the local community. For this project, after-school activities will be developed to introduce topics of energy production and environmental stewardship. From a scientific point of view, this project will provide a better understanding of the geochemical controls on hazardous element mobilization in flow-back and production wastewaters during fracking and shale gas extraction. The project will generate first-of-a-kind information about how barium (Ba), uranium (U) and radium (Ra) in shale formation rocks are distributed among mineral and organic phases. This information is critical for the development of geochemical models that predict hazardous element mobilization due to selective dissolution of mineral phases. Collectively the new knowledge gained will lead to a generalizable approach to assess hazardous element contamination in flow-back and production wastewaters. This project will use the advanced understanding of flow-back and production wastewaters content to generate fundamentally new knowledge about the factors that affect Ba and Ra co-precipitation relevant to industrial treatment operations, and how fracking fluid additives may inhibit or foster this process.