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Jiang J, Xiang X, Zhou Q, Zhou L, Bi X, Khanal SK, Wang Z, Chen G, Guo G. Optimization of a Novel Engineered Ecosystem Integrating Carbon, Nitrogen, Phosphorus, and Sulfur Biotransformation for Saline Wastewater Treatment Using an Interpretable Machine Learning Approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:12989-12999. [PMID: 38982970 DOI: 10.1021/acs.est.4c03160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
The denitrifying sulfur (S) conversion-associated enhanced biological phosphorus removal (DS-EBPR) process for treating saline wastewater is characterized by its unique microbial ecology that integrates carbon (C), nitrogen (N), phosphorus (P), and S biotransformation. However, operational instability arises due to the numerous parameters and intricates bacterial interactions. This study introduces a two-stage interpretable machine learning approach to predict S conversion-driven P removal efficiency and optimize DS-EBPR process. Stage one utilized the XGBoost regression model, achieving an R2 value of 0.948 for predicting sulfate reduction (SR) intensity from anaerobic parameters with feature engineering. Stage two involved the CatBoost classification and regression model integrating anoxic parameters with the predicted SR values for predicting P removal, reaching an accuracy of 94% and an R2 value of 0.93, respectively. This study identified key environmental factors, including SR intensity (20-45 mg S/L), influent P concentration (<9.0 mg P/L), mixed liquor volatile suspended solids (MLVSS)/mixed liquor suspended solids (MLSS) ratio (0.55-0.72), influent C/S ratio (0.5-1.0), anoxic reaction time (5-6 h), and MLSS concentration (>6.50 g/L). A user-friendly graphic interface was developed to facilitate easier optimization and control. This approach streamlines the determination of optimal conditions for enhancing P removal in the DS-EBPR process.
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Affiliation(s)
- Jinqi Jiang
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science & Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, Hubei 430074, China
- School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiang Xiang
- School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Qinhao Zhou
- School of Artificial Intelligence and Automation, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Lichang Zhou
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science & Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, Hubei 430074, China
| | - Xinqi Bi
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science & Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, Hubei 430074, China
| | - Samir Kumar Khanal
- Department of Molecular Biosciences and Bioengineering, University of Hawai'i at Ma̅noa, 1955 East-West Road, Honolulu, Hawaii 96822, United States
| | - Zongping Wang
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science & Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, Hubei 430074, China
| | - Guanghao Chen
- Civil & Environmental Engineering and Hong Kong Branch of the Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, The Hong Kong University of Science and Technology, Hong Kong 999077, PR China
| | - Gang Guo
- Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science & Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, Hubei 430074, China
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Masindi V, Foteinis S, Renforth P, Chatzisymeon E. Wastewater Treatment for Carbon Dioxide Removal. ACS OMEGA 2023; 8:40251-40259. [PMID: 37929097 PMCID: PMC10620921 DOI: 10.1021/acsomega.3c04231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 10/05/2023] [Indexed: 11/07/2023]
Abstract
Wastewater treatment is notorious for its hefty carbon footprint, accounting for 1-2% of global greenhouse gas (GHG) emissions. Nonetheless, the treatment process itself could also present an innovative carbon dioxide removal (CDR) approach. Here, the calcium (Ca)-rich effluent of a phosphorus (P) recovery system from municipal wastewater (P recovered as calcium phosphate) was used for CDR. The effluent was bubbled with concentrated CO2, leading to its mineralization, i.e., CO2 stored as stable carbonate minerals. The chemical and microstructural properties of the newly formed minerals were ascertained by using state-of-the-art analytical techniques. FTIR identified CO3 bonds and carbonate stretching, XRF and SEM-EDX measured a high Ca concentration, and SEM imaging showed that Ca is well distributed, suggesting homogeneous formation. Furthermore, FIB-SEM revealed rhombohedral and needle-like structures and TEM revealed rod-like structures, indicating that calcium carbonate (CaCO3) was formed, while XRD suggested that this material mainly comprises aragonite and calcite. Results imply that high-quality CaCO3 was synthesized, which could be stored or valorized, while if atmospheric air is used for bubbling, a partial direct air capture (DAC) system could be achieved. The quality of the bubbled effluent was also improved, thus creating water reclamation and circular economy opportunities. Results are indicative of other alkaline Ca-rich wastewaters such as effluents or leachates from legacy iron and steel wastes (steel slags) that can possibly be used for CDR. Overall, it was identified that wastewater can be used for carbon mineralization and can greatly reduce the carbon footprint of the treatment process, thus establishing sustainable paradigms for the introduction of CDR in this sector.
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Affiliation(s)
- Vhahangwele Masindi
- Magalies
Water, Scientific Services, Research & Development Division, Erf 3475, Stoffberg street, Brits 0250, South Africa
- Department
of Environmental Sciences, College of Agriculture and Environmental
Sciences, University of South Africa (UNISA), P.O. Box 392, Florida 1710, South Africa
| | - Spyros Foteinis
- Research
Centre for Carbon Solutions, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Phil Renforth
- Research
Centre for Carbon Solutions, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Efthalia Chatzisymeon
- School
of Engineering, Institute for Infrastructure
and Environment, University of Edinburgh, Edinburgh EH9 3JL, United Kingdom
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Hong M, Xu G, Lu P, Chen F, Sheng G, Zhang Q. Numerical simulation on gas-droplet flow characteristics and spray evaporation process in CFB-FGD tower. ADV POWDER TECHNOL 2023. [DOI: 10.1016/j.apt.2023.104008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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Chen H, Zhan L, Zhou H, Li Z, Chen J, Sun Z, Wu H, Yang L. Release and migration of Hg during desulfurization wastewater evaporation process: Whole process evaluation by experimental and theoretical study. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130180. [PMID: 36272368 DOI: 10.1016/j.jhazmat.2022.130180] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 09/29/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Hot flue gas evaporation technology is an effective strategy for zero liquid discharge of desulfurization wastewater. However, there is a potential risk that heavy metals such as Hg may be released from the wastewater during evaporation, disrupting the original balance of the power plant or even exceeding the Hg emission standard. Wastewater evaporation and Hg release behavior were obtained using a single droplet drying system. At an evaporation temperature of 300 °C, approximately 18.5% of Hg was released in the constant wet-bulb temperature period, and the remaining was released in the following evaporation periods. Furthermore, a fixed-bed experiment, in combination with density functional theory calculations, was used to investigate the possible migration mechanisms of released Hg. The results revealed that high HCl concentration, introduced fly ash, and precipitated evaporation products play a crucial role in the fate of Hg, and 85.3% of Hg finally turned into less harmful particulate-bound Hg. This study provides a new and effective strategy for evaluating the migration process of pollutants in wastewater treatment. Moreover, it will serve as an essential reference for advanced wastewater treatment and heavy metals control technologies in the future.
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Affiliation(s)
- Heng Chen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Lingxiao Zhan
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Hao Zhou
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Zhihao Li
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Jiawei Chen
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China
| | - Zongkang Sun
- Guangdong Electric Power Development Co., Ltd., Guangzhou, China
| | - Hao Wu
- School of Energy & Mechanical Engineering, Nanjing Normal University, Nanjing, China
| | - Linjun Yang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry Education, School of Energy and Environment, Southeast University, Nanjing, China.
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Hu X, Ji Z, Gu S, Ma Z, Yan Z, Liang Y, Chang H, Liang H. Mapping the research on desulfurization wastewater: Insights from a bibliometric review (1991-2021). CHEMOSPHERE 2023; 314:137678. [PMID: 36586446 DOI: 10.1016/j.chemosphere.2022.137678] [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: 10/18/2022] [Revised: 12/05/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
Desulfurization wastewater in coal-fired power plants (CFPPs) is a great environmental challenge. This study aimed at the current status and future research trends of desulfurization wastewater by bibliometric analysis. The desulfurization wastewater featured with high sulfate (8000 mg/L), chlorite (8505 mg/L), magnesium (2882 mg/L) and calcium (969 mg/L) but low sodium (801.82 mg/L), and the concentrations of the main contaminants were critically summarized. There was an increasing trend in the annual publications of desulfurization wastewater in the period from 1991 to 2021, with an average growth rate of 15%. Water Science and Technology, Desalination and Water Treatment, Energy & Fuels, Chemosphere, and Journal of Hazardous Materials are the top 5 journals in this field. China was the most productive country (58.3% of global output) and the core country in the international cooperation network. Wordcloud analysis and keyword topic trend demonstrated that removal/treatment of pollutants dominated the global research in the field of desulfurization wastewater. The primary technologies for desulfurization wastewater treatment were systematically evaluated. The physicochemical treatment technologies occupied half of the total treatment methods, while membrane-based integrated processes showed potential applications for beneficial reuse. The challenges and outlook on desulfurization wastewater treatment for achieving zero liquid discharge are summarized.
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Affiliation(s)
- Xueqi Hu
- State Grid Sichuan Comprehensive Energy Service Co., Ltd., Power Engineering Br., Chengdu, 610072, China
| | - Zhengxuan Ji
- School of Architecture and Civil Engineering, Xi'an University of Science and Technology, Xi'an, 710054, China
| | - Suhua Gu
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610207, China
| | - Zeren Ma
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610207, China
| | - Zhongsen Yan
- College of Civil Engineering, Fuzhou University, Fuzhou, 350116, China
| | - Ying Liang
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610207, China
| | - Haiqing Chang
- MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610207, China.
| | - Heng Liang
- State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, Harbin, 150090, China
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Czupryński P, Płotka M, Glamowski P, Żukowski W, Bajda T. An assessment of an ion exchange resin system for the removal and recovery of Ni, Hg, and Cr from wet flue gas desulphurization wastewater-a pilot study. RSC Adv 2022; 12:5145-5156. [PMID: 35425530 PMCID: PMC8981258 DOI: 10.1039/d1ra09426b] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 02/04/2022] [Indexed: 11/21/2022] Open
Abstract
The paper presents the results of a pilot-scale study investigating the efficiency of an ion exchange resin system in the removal of Ni, Hg, and Cr from flue gas desulphurisation wastewater, in the presence of competitive metals such as Ca, Mg, Al, Fe, and Mn. The core part of the ion exchange installation consisted of two columns that were filled with ion exchange resin with iminodiacetic functional groups (Purolite S930) and one column filled with resin with isothiouronium functional groups (Purolite S920). The results showed that Ni, Hg, and Cr were almost completely removed from the wastewater with nearly 100% efficiency. Purolite S930 almost totally removed Ni, reducing its content from 89.3 ± 35 μg dm-3 to below 0.1 μg dm-3, while Purolite S920 reduced the remaining Cr content from 2.2 ± 0.6 μg dm-3 and most of the Hg content, from 23.5 ± 6.6 μg dm-3 to below 0.1 μg dm-3. The competitive metals Ca, Mg, Mn, and Al showed low affinity to the studied ion exchange resins. The study also assessed speciation of ion forms and sorption mechanisms. Breakthrough curve analysis was also carried out, which revealed that the selectivity sequence of iminodiacetic resin was Ni > Cr > Hg > Fe > Al > Mn > Ca, Mg. Elution studies were performed on S930 resins that allowed the separation of two streams: one containing mostly Ni and Fe which can be subjected to Ni recovery and the other containing mostly Cr and Hg which can be separated.
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Affiliation(s)
- Piotr Czupryński
- AGH University of Science and Technology, Faculty of Geology, Geophysics and Environmental Protection Al. Mickiewicza 30 30-059 Kraków Poland .,PGE Energia Ciepła S.A. ul. Złota 59 00-120 Warszawa Poland
| | | | | | - Witold Żukowski
- Cracow University of Technology, Faculty of Chemical Engineering and Technology Warszawska 24 31-155 Kraków Poland
| | - Tomasz Bajda
- AGH University of Science and Technology, Faculty of Geology, Geophysics and Environmental Protection Al. Mickiewicza 30 30-059 Kraków Poland
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Zhang T, Tang Q, Pu C, Zhang L. Numerical simulation of gas-droplets mixing and spray evaporation in rotary spray desulfurization tower. ADV POWDER TECHNOL 2022. [DOI: 10.1016/j.apt.2021.103420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Hsu CJ, Atkinson JD, Chung A, Hsi HC. Gaseous mercury re-emission from wet flue gas desulfurization wastewater aeration basins: A review. JOURNAL OF HAZARDOUS MATERIALS 2021; 420:126546. [PMID: 34252671 DOI: 10.1016/j.jhazmat.2021.126546] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/25/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
Wet flue gas desulfurization (WFGD) simultaneously removes Hg and SO2 from coal-fired power plant flue gas streams. Hg0 re-emission occurs when the dissolved Hg(II) is converted to a volatile form (i.e., Hg0) that can be subsequently emitted into the ambient air from WFGD wastewater aeration basins. Others have shown that Hg0 re-emission depends on pH, temperature, ligands (Cl, Br, I, F, SO32-, SO42-, NO3-, SCN-, and ClO-), O2, minerals (Se and As), and metals (Fe and Cu) in WFGD wastewater. Still others have shown Hg0 re-emission restriction via inhibitor addition (adsorbents and precipitators). This is the first review that summarizes the complex and inconsistently reported Hg0 re-emission mechanisms, updates misconceptions related to Hg(II) complexation and reduction, and reviews applications of inhibitors that convert aqueous Hg(II) into stable solid forms to prevent gaseous Hg0 formation and release.
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Affiliation(s)
- Che-Jung Hsu
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - John D Atkinson
- Department of Civil, Structural and Environmental Engineering, The State University of New York at Buffalo, New York 14260, United States
| | - Adrienne Chung
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Hsing-Cheng Hsi
- Graduate Institute of Environmental Engineering, National Taiwan University, Taipei 10617, Taiwan.
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Chen G, Han K, Liu C, Yan B. Quantitative research on heavy metal removal of flue gas desulfurization-derived wastewater sludge by electrokinetic treatment. JOURNAL OF HAZARDOUS MATERIALS 2021; 414:125561. [PMID: 34030412 DOI: 10.1016/j.jhazmat.2021.125561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 02/27/2021] [Accepted: 02/27/2021] [Indexed: 06/12/2023]
Abstract
Flue gas desulfurization-derived wastewater sludge (FGD-WWS) has been produced increasingly in China and India etc., and its content of heavy metals (HMs) including Cd, Cr, Cu, Hg, Ni and Zn seriously exceeds the limits allowed. Developing the suitable disposal of FGD-WWS is therefore significantly important and necessary. The novel process of electrokinetic treatment combined with chemical pretreatment of HMs in FGD-WWS were proposed here to improve the removal efficiency. Results indicate that the effects of different pretreatment agents (citric acid (CA), ammonia, tetrasodium of N, N-bis (carboxymethyl) glutamic acid (GLDA), and rhamnolipid) on the ET of HMs were different. To investigate the mechanism of combined process, the transformation potential (TP), exchange potential (EP) and removal potential (RP) were calculated. Correlation analysis shows the correlation between TP and RP was higher than that between EP and RP, indicating that the removal efficiency is mainly affected by the fraction transformation of HMs. Electric field, pH and pretreatment agents are main factors causing fraction transformation and affecting TP. Focusing on fraction transformation is an efficient way to improve further the removal efficiency. The work is promisingly valuable for developing the technology of treating FGD-WWS.
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Affiliation(s)
- Guanyi Chen
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China; School of Mechanical Engineering, Tianjin University of Commerce, Lhasa 850012, China; School of Science, Tibet University, Lhasa 850012, China; Tianjin Engineering Research Center for Organic Wastes Safe Disposal and Energy Utilization, Tianjin 300072, China
| | - Kexuan Han
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China
| | - Caixia Liu
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China; Tianjin Engineering Research Center for Organic Wastes Safe Disposal and Energy Utilization, Tianjin 300072, China.
| | - Beibei Yan
- School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China; Tianjin Key Lab of Biomass/waste Utilization, Tianjin 300072, China; Tianjin Engineering Research Center for Organic Wastes Safe Disposal and Energy Utilization, Tianjin 300072, China
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Martin G, Sharma S, Ryan W, Srinivasan NK, Senko JM. Identification of Microbiological Activities in Wet Flue Gas Desulfurization Systems. Front Microbiol 2021; 12:675628. [PMID: 34262541 PMCID: PMC8273512 DOI: 10.3389/fmicb.2021.675628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/07/2021] [Indexed: 11/18/2022] Open
Abstract
Thermoelectric power generation from coal requires large amounts of water, much of which is used for wet flue gas desulfurization (wFGD) systems that minimize sulfur emissions, and consequently, acid rain. The microbial communities in wFGDs and throughout thermoelectric power plants can influence system performance, waste processing, and the long term stewardship of residual wastes. Any microorganisms that survive in wFGD slurries must tolerate high total dissolved solids concentrations (TDS) and temperatures (50–60°C), but the inocula for wFGDs are typically from fresh surface waters (e.g., lakes or rivers) of low TDS and temperatures, and whose activity might be limited under the physicochemically extreme conditions of the wFGD. To determine the extents of microbiological activities in wFGDs, we examined the microbial activities and communities associated with three wFGDs. O2 consumption rates of three wFGD slurries were optimal at 55°C, and living cells could be detected microscopically, indicating that living and active communities of organisms were present in the wFGD and could metabolize at the high temperature of the wFGD. A 16S rRNA gene-based survey revealed that the wFGD-associated microbial communities included taxa attributable to both thermophilic and mesophilic lineages. Metatranscriptomic analysis of one of the wFGDs indicated an abundance of active Burholderiaceae and several Gammaproteobacteria, and production of transcripts associated with carbohydrate metabolism, osmotic stress response, as well as phage, prophages, and transposable elements. These results illustrate that microbial activities can be sustained in physicochemically extreme wFGDs, and these activities may influence the performance and environmental impacts of thermoelectric power plants.
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Affiliation(s)
- Gregory Martin
- Department of Biology, The University of Akron, Akron, OH, United States
| | - Shagun Sharma
- Department of Biology, The University of Akron, Akron, OH, United States.,Integrated Bioscience Program, The University of Akron, Akron, OH, United States
| | - William Ryan
- Department of Biology, The University of Akron, Akron, OH, United States
| | | | - John M Senko
- Department of Biology, The University of Akron, Akron, OH, United States.,Integrated Bioscience Program, The University of Akron, Akron, OH, United States.,Department of Geosciences, The University of Akron, Akron, OH, United States
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