1
|
Li Y, Bai H, Li Y, Zhang X, Zhang L, Zhang D, Xu M, Zhang H, Lu P. An integrated approach to identify the source apportionment of potentially toxic metals in shale gas exploitation area soil, and the associated ecological and human health risks. JOURNAL OF HAZARDOUS MATERIALS 2023; 458:132006. [PMID: 37453347 DOI: 10.1016/j.jhazmat.2023.132006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 06/07/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023]
Abstract
Public awareness of the potential environmental risks of shale gas extraction has increased in recent years. However, the status and environmental risks of potentially toxic metals (PTMs) in shale gas field soil remain unclear. A total of 96 topsoil samples were collected from the first shale gas exploitation area in China. The sources of nine PTMs in the soils were identified using positive matrix factorization and correlation analysis, and the ecological and human health risks of toxic metals from different sources under the two land use types were calculated. The results showed that mean pollution load index (PLI) values for farmland (1.18) and woodland (1.40) indicated moderate pollution, As, Cd and Ni were the most serious contaminants among all nine PTMs. The following four sources were identified: shale gas extraction activities (43.90%), nature sources (31.90%), agricultural and traffic activities (17.55%) and industrial activities (6.55%). For ecological risk, the mean ecological risk index (RI) values for farmlands (161.95) and woodlands (185.27) reaching considerable risk. The contribution ratio of shale gas extraction activities for farmlands and woodlands were 5.70% and 8.90%, respectively. Regarding human health risk, noncarcinogenic risks for adults in farmlands and woodlands were negligible. Industrial activities, agricultural and traffic activities were estimated to be the important sources of health risks. Overall, shale gas extraction activities had little impact on the ecological and human health risk. This study provides scientific evidence regarding the soil contamination potential of shale gas development activities.
Collapse
Affiliation(s)
- Yan Li
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China
| | - Hongcheng Bai
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, Sichuan, China
| | - Yutong Li
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China; Chongqing Academy of Eco-environmental Science, Chongqing 401147, China
| | - Xin Zhang
- The Key Laboratory of GIS Application and Research, Chongqing Normal University, Chongqing 401331, China
| | - Lilan Zhang
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China
| | - Daijun Zhang
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China
| | - Min Xu
- Department of Environmental Science, College of Sichuan Agricultural University, Chengdu 611130, China
| | - Hong Zhang
- The Key Laboratory of GIS Application and Research, Chongqing Normal University, Chongqing 401331, China
| | - Peili Lu
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China.
| |
Collapse
|
2
|
Hernandez-Becerra N, Cliffe L, Xiu W, Boothman C, Lloyd JR, Nixon SL. New microbiological insights from the Bowland shale highlight heterogeneity of the hydraulically fractured shale microbiome. ENVIRONMENTAL MICROBIOME 2023; 18:14. [PMID: 36855215 PMCID: PMC9972762 DOI: 10.1186/s40793-023-00465-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 01/11/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Hydraulically fractured shales offer a window into the deep biosphere, where hydraulic fracturing creates new microbial ecosystems kilometers beneath the surface of the Earth. Studying the microbial communities from flowback fluids that are assumed to inhabit these environments provides insights into their ecophysiology, and in particular their ability to survive in these extreme environments as well as their influence on site operation e.g. via problematic biofouling processes and/or biocorrosion. Over the past decade, research on fractured shale microbiology has focused on wells in North America, with a few additional reported studies conducted in China. To extend the knowledge in this area, we characterized the geochemistry and microbial ecology of two exploratory shale gas wells in the Bowland Shale, UK. We then employed a meta-analysis approach to compare geochemical and 16S rRNA gene sequencing data from our study site with previously published research from geographically distinct formations spanning China, Canada and the USA. RESULTS Our findings revealed that fluids recovered from exploratory wells in the Bowland are characterized by moderate salinity and high microbial diversity. The microbial community was dominated by lineages known to degrade hydrocarbons, including members of Shewanellaceae, Marinobacteraceae, Halomonadaceae and Pseudomonadaceae. Moreover, UK fractured shale communities lacked the usually dominant Halanaerobium lineages. From our meta-analysis, we infer that chloride concentrations play a dominant role in controlling microbial community composition. Spatio-temporal trends were also apparent, with different shale formations giving rise to communities of distinct diversity and composition. CONCLUSIONS These findings highlight an unexpected level of compositional heterogeneity across fractured shale formations, which is not only relevant to inform management practices but also provides insight into the ability of diverse microbial consortia to tolerate the extreme conditions characteristic of the engineered deep subsurface.
Collapse
Affiliation(s)
- Natali Hernandez-Becerra
- Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| | - Lisa Cliffe
- Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
| | - Wei Xiu
- Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing, China
| | - Christopher Boothman
- Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| | - Jonathan R Lloyd
- Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK
| | - Sophie L Nixon
- Williamson Research Centre for Molecular Environmental Science, Department of Earth and Environmental Sciences, The University of Manchester, Manchester, UK.
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK.
| |
Collapse
|
3
|
Cliffe L, Hernandez-Becerra N, Boothman C, Eden B, Lloyd JR, Nixon SL. Guar Gum Stimulates Biogenic Sulfide Production in Microbial Communities Derived from UK Fractured Shale Production Fluids. Microbiol Spectr 2022; 10:e0364022. [PMID: 36453927 PMCID: PMC9769687 DOI: 10.1128/spectrum.03640-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 11/10/2022] [Indexed: 12/03/2022] Open
Abstract
Shale gas production fluids offer a window into the engineered deep biosphere. Here, for the first time, we report on the geochemistry and microbiology of production fluids from a UK shale gas well in the Bowland shale formation. The composition of input fluids used to fracture this well were comparatively lean, consisting only of water, sand, and polyacrylamide. This formation therefore represents an interesting comparison to previously explored fractured shales in which more additives were used in the input fluids. Here, we combine cultivation and molecular ecology techniques to explore the microbial community composition of hydraulic fracturing production fluids, with a focus on the potential for common viscosity modifiers to stimulate microbial growth and biogenic sulfide production. Production fluids from a Bowland Shale exploratory well were used as inocula in substrate utilization experiments to test the potential for polyacrylamide and guar gum to stimulate microbial metabolism. We identified a consortium of thiosulfate-reducing bacteria capable of utilizing guar gum (but not polyacrylamide), resulting in the production of corrosive and toxic hydrogen sulfide. Results from this study indicate polyacrylamide is less likely than guar gum to stimulate biogenic sulfide production during shale gas extraction and may guide planning of future hydraulic fracturing operations. IMPORTANCE Shale gas exploitation relies on hydraulic fracturing, which often involves a range of chemical additives in the injection fluid. However, relatively little is known about how these additives influence fractured shale microbial communities. This work offers a first look into the microbial community composition of shale gas production fluids obtained from an exploratory well in the Bowland Shale, United Kingdom. It also seeks to establish the impact of two commonly used viscosity modifiers, polyacrylamide and guar gum, on microbial community dynamics and the potential for microbial sulfide production. Not only does this work offer fascinating insights into the engineered deep biosphere, it could also help guide future hydraulic fracturing operations that seek to minimize the risk of biogenic sulfide production, which could reduce efficiency and increase environmental impacts of shale gas extraction.
Collapse
Affiliation(s)
- Lisa Cliffe
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom
| | - Natali Hernandez-Becerra
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom
| | - Christopher Boothman
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom
| | - Bob Eden
- Rawwater Engineering Company Limited, Culcheth, United Kingdom
| | - Jonathan R. Lloyd
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom
| | - Sophie L. Nixon
- Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| |
Collapse
|
4
|
Zhong C, Zolfaghari A, Hou D, Goss GG, Lanoil BD, Gehman J, Tsang DCW, He Y, Alessi DS. Comparison of the Hydraulic Fracturing Water Cycle in China and North America: A Critical Review. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:7167-7185. [PMID: 33970611 DOI: 10.1021/acs.est.0c06119] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
There is considerable debate about the sustainability of the hydraulic fracturing (HF) water cycle in North America. Recently, this debate has expanded to China, where HF activities continue to grow. Here, we provide a critical review of the HF water cycle in China, including water withdrawal practices and flowback and produced water (FPW) management and their environmental impacts, with a comprehensive comparison to the U.S. and Canada (North America). Water stress in arid regions, as well as water management challenges, FPW contamination of aquatic and soil systems, and induced seismicity are all impacts of the HF water cycle in China, the U.S., and Canada. In light of experience gained in North America, standardized practices for analyzing and reporting FPW chemistry and microbiology in China are needed to inform its efficient and safe treatment, discharge and reuse, and identification of potential contaminants. Additionally, conducting ecotoxicological studies is an essential next step to fully reveal the impacts of accidental FPW releases into aquatic and soil ecosystems in China. From a policy perspective, the development of China's unconventional resources lags behind North America's in terms of overall regulation, especially with regard to water withdrawal, FPW management, and routine monitoring. Our study suggests that common environmental risks exist within the world's two largest HF regions, and practices used in North America may help prevent or mitigate adverse effects in China.
Collapse
Affiliation(s)
- Cheng Zhong
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada
- School of Environment, Tsinghua University, Beijing, China
| | - Ashkan Zolfaghari
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Deyi Hou
- School of Environment, Tsinghua University, Beijing, China
| | - Greg G Goss
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Brian D Lanoil
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Joel Gehman
- Department of Strategy, Entrepreneurship and Management, University of Alberta, Edmonton, Alberta, Canada
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Yuhe He
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon Tong, Kowloon, Hong Kong, China
| | - Daniel S Alessi
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|