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Pan Y, She D, Ding J, Abulaiti A, Zhao J, Wang Y, Liu R, Wang F, Shan J, Xia Y. Coping with groundwater pollution in high-nitrate leaching areas: The efficacy of denitrification. ENVIRONMENTAL RESEARCH 2024; 250:118484. [PMID: 38373544 DOI: 10.1016/j.envres.2024.118484] [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: 09/23/2023] [Revised: 01/31/2024] [Accepted: 02/13/2024] [Indexed: 02/21/2024]
Abstract
The Ningxia Yellow River irrigation area, characterized by an arid climate and high leaching of NO3--N, exhibits complex and unique groundwater nitrate (NO3--N) pollution, with denitrification serving as the principal mechanism for NO3--N removal. The characteristics of N leaching from paddy fields and NO3--N removal by groundwater denitrification were investigated through a two-year field observation. The leaching losses of total nitrogen (TN) and NO3--N accounted for 10.81-27.34% and 7.59-12.74%, respectively, of the N input. The linear relationship between NO3--N leaching and N input indicated that the fertilizer-induced emission factor (EF) of NO3--N leaching in direct dry seeding and seedling-raising and transplanting paddy fields was 8.2% (2021, R2 = 0.992) and 6.7% (2022, R2 = 0.994), respectively. The study highlighted that the quadratic relationship between the NO3--N leaching loss and N input (R2 = 0.999) significantly outperformed the linear relationship. Groundwater denitrification capacity was characterized by monitoring the concentrations of dinitrogen (N2) and nitrous oxide (N2O). The results revealed substantial seasonal fluctuations in excess N2 and N2O concentrations in groundwater, particularly following fertilization and irrigation events. The removal efficiency of NO3--N via groundwater denitrification ranged from 42.70% to 74.38%, varying with depth. Groundwater denitrification capacity appeared to be linked to dissolved organic carbon (DOC) concentration, redox conditions, fertilization, irrigation, and soil texture. The anthropogenic-alluvial soil with limited water retention accelerated the leaching of NO3--N into groundwater during irrigation. This process enhances the groundwater recharge capacity and alters the redox conditions of groundwater, consequently impacting groundwater denitrification activity. The DOC concentration emerged as the primary constraint on the groundwater denitrification capacity in this region. Hence, increasing carbon source concentration and enhancing soil water retention capacity are vital for improving the groundwater denitrification capacity and NO3--N removal efficiency. This study provides practical insights for managing groundwater NO3--N pollution in agricultural areas, optimizing fertilization strategies and improving groundwater quality.
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Affiliation(s)
- Yongchun Pan
- College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China; Jiangsu Province Engineering Research Center for Agricultural Soil‒Water Efficient Utilization, Carbon Sequestration and Emission Reduction, Nanjing, 210098, China
| | - Dongli She
- College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China; College of Soil and Water Conservation, Hohai University, Changzhou, 213200, China.
| | - Jihui Ding
- College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China
| | - Alimu Abulaiti
- College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China; Jiangsu Province Engineering Research Center for Agricultural Soil‒Water Efficient Utilization, Carbon Sequestration and Emission Reduction, Nanjing, 210098, China
| | - Junhan Zhao
- College of Agricultural Science and Engineering, Hohai University, Nanjing, 210098, China; Jiangsu Province Engineering Research Center for Agricultural Soil‒Water Efficient Utilization, Carbon Sequestration and Emission Reduction, Nanjing, 210098, China
| | - Ying Wang
- Institute of Agricultural Resources and Environment, Ningxia Academy of Agro-forestry Science, Yinchuan, 750002, China
| | - Ruliang Liu
- Institute of Agricultural Resources and Environment, Ningxia Academy of Agro-forestry Science, Yinchuan, 750002, China
| | - Fang Wang
- Institute of Agricultural Resources and Environment, Ningxia Academy of Agro-forestry Science, Yinchuan, 750002, China
| | - Jun Shan
- Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Yongqiu Xia
- Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
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Li R, Xi B, Wang X, Li Y, Yuan Y, Tan W. Anaerobic oxidation of methane in landfill and adjacent groundwater environments: Occurrence, mechanisms, and potential applications. WATER RESEARCH 2024; 255:121498. [PMID: 38522398 DOI: 10.1016/j.watres.2024.121498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/08/2024] [Accepted: 03/19/2024] [Indexed: 03/26/2024]
Abstract
Landfills remain the predominant means of solid waste management worldwide. Widespread distribution and significant stockpiles of waste in landfills make them a significant source of methane emissions, exacerbating climate change. Anaerobic oxidation of methane (AOM) has been shown to play a critical role in mitigating methane emissions on a global scale. The rich methane and electron acceptor environment in landfills provide the necessary reaction conditions for AOM, making it a potentially low-cost and effective strategy for reducing methane emissions in landfills. However, compared to other anaerobic habitats, research on AOM in landfill environments is scarce, and there is a lack of analysis on the potential application of AOM in different zones of landfills. Therefore, this review summarizes the existing knowledge on AOM and its occurrence in landfills, analyzes the possibility of AOM occurrence in different zones of landfills, discusses its potential applications, and explores the challenges and future research directions for AOM in landfill management. The identification of research gaps and future directions outlined in this review encourages further investigation and advancement in the field of AOM, paving the way for more effective waste stabilization, greenhouse gas reduction, and pollutant mitigation strategies in landfills.
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Affiliation(s)
- Renfei Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China; School of Environment, Tsinghua University, Beijing 100084, PR China
| | - Beidou Xi
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China; School of Environment, Tsinghua University, Beijing 100084, PR China.
| | - Xiaowei Wang
- Department of Environmental Science and Engineering, Beijing Technology and Business University, Beijing 100048, PR China
| | - Yanjiao Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Ying Yuan
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
| | - Wenbing Tan
- State Key Laboratory of Environmental Criteria and Risk Assessment, and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution, Chinese Research Academy of Environmental Sciences, Beijing 100012, PR China
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Xia Q, He J, He B, Chu Y, Li W, Sun J, Wen D. Effect and genesis of soil nitrogen loading and hydrogeological conditions on the distribution of shallow groundwater nitrogen pollution in the North China Plain. WATER RESEARCH 2023; 243:120346. [PMID: 37482006 DOI: 10.1016/j.watres.2023.120346] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 07/08/2023] [Accepted: 07/11/2023] [Indexed: 07/25/2023]
Abstract
The North China Plain (NCP) has experienced increasingly severe groundwater nitrogen (TN) pollution. However, the factors influencing TN distribution are still poorly understood. Previous studies have identified surface soil nitrogen (TSN) loading and intrinsic groundwater vulnerability (Inv) as the main factors controlling groundwater TN pollution. However, in this study, based on 3245 shallow groundwater samples in the NCP, the multiple regression analysis results(R2=0.105, p<0.001) revealed that the TN was not mainly controlled by TSN and Inv. The lower prediction accuracy indicated the large data dispersion of TN, which might be affected by nitrogen attenuation or accumulation. Thus, the NCP was divided into balance, attenuation, and accumulation zones according to the regression equation. The attenuation zone was mainly distributed in the inter-fan and fan edge parts of the pre-mountain alluvial floodplain, as well as the west and south of the runoff area, while the accumulation zone was mainly distributed in the top part of the pre-mountain alluvial floodplain and the east of discharge area. Multi-indicators comparative analysis showed that compared to the balance (Eh= 76.2 mV) and accumulation (Eh=126.7 mV) zones, the attenuation zone has a stronger reducing environment (Eh=30.8 mV) favorable to denitrification, which can reduce the TN pollution (0.49 mg/L) caused by surface nitrogen input and consume more electron donors. Conversely, the stronger oxidizing environment in the accumulation zone limited denitrification, resulting in higher TN concentrations (19.14 mg/L) in the aquifers under the same TSN and Inv conditions as the other two zones. The standardized effects and significance on each path of the structural equation model (SEMs) fully confirmed the reliability of the above zonal analysis. Importantly, the feature importance (23.6%) of random forest and standardized effects (0.455, p<0.001) of SEMs showed that the Eh had the strongest influence on TN. Thus, the redox conditions of the aquifer, in addition to TSN and Inv, played a crucial role in controlling the TN pollution in the groundwater of a large region. The zoning work and the analysis of influencing factors are important to guide scientific prevention and control of groundwater nitrogen pollution.
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Affiliation(s)
- Qiwen Xia
- Key Laboratory of Groundwater Conservation of Ministry of Water Resources, China University of Geosciences, Beijing 100083, China
| | - Jiangtao He
- Key Laboratory of Groundwater Conservation of Ministry of Water Resources, China University of Geosciences, Beijing 100083, China.
| | - Baonan He
- Key Laboratory of Groundwater Conservation of Ministry of Water Resources, China University of Geosciences, Beijing 100083, China.
| | - Yanjia Chu
- Key Laboratory of Groundwater Conservation of Ministry of Water Resources, China University of Geosciences, Beijing 100083, China
| | - Wei Li
- Key Laboratory of Groundwater Conservation of Ministry of Water Resources, China University of Geosciences, Beijing 100083, China
| | - Jichao Sun
- Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Dongguang Wen
- Hydrogeology and Environmental Geological Survey Center of China Geological Survey, Baoding 071051, China
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Xiong R, Li Y, Gao X, Li N, Lou R, Saeed L, Huang J. Effects of a long-term operation wetland for wastewater treatment on the spatial pattern and function of microbial communities in groundwater. ENVIRONMENTAL RESEARCH 2023; 228:115929. [PMID: 37072080 DOI: 10.1016/j.envres.2023.115929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 04/12/2023] [Accepted: 04/15/2023] [Indexed: 05/16/2023]
Abstract
Constructed wetlands have been used globally for wastewater treatment owing to low energy inputs and operating costs. However, the impact of their long-term operation on groundwater microbial communities is still unclear. This study aims to investigate the effects and further reveal the linkage between a large-scale surface flow constructed wetland (in operation for 14 years) and groundwater. Changes in the characteristics of groundwater microbial communities and their potential influencing factors were studied based on hydrochemical analysis, Illumina MiSeq sequencing, and multivariate statistical analysis methods. Results show that the long-term operation wetland significantly elevated groundwater nutrient levels and increased the risk of ammonia nitrogen pollution compared to background values. An apparent heterogeneity of microbial communities exhibited in the vertical direction and a similarity in the horizontal direction. Wetland operations substantially altered the structure of microbial communities at 3, 5, and 12 m depths, particularly a reduced abundance of denitrifying and chemoheterotrophic functional genera. The formation and evolution of groundwater microbial community structure mainly subjected to the contributions of dissolved oxygen (33.70%), total nitrogen (21.40%), dissolved organic carbon (11.09%), and pH (10.60%) variations resulted from the wetland operation and largely differed in depths. A combined effect of these factors on the groundwater should be concerned for such a long-term running wetland system. This study provides a new insight into the responses of groundwater microbial community structure driving by wetland operation and a better understanding of corresponding variation of microbial-based geochemical processes.
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Affiliation(s)
- Rongwei Xiong
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, PR China
| | - Yong Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, PR China; National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety, Hohai University, Nanjing, 210098, PR China.
| | - Xiufang Gao
- College of Resources and Environment, Yangtze University, Wuhan, 430100, PR China; Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education, Jingzhou, 434025, PR China
| | - Na Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, PR China
| | - Ruitao Lou
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, PR China
| | - Laraib Saeed
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, PR China
| | - Jinquan Huang
- Department of Soil and Water Conservation, Yangtze River Scientific Research Institute, Wuhan, 430010, PR China
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Chen X, Wang G, Sheng Y, Liao F, Mao H, Li B, Zhang H, Qiao Z, He J, Liu Y, Lin Y, Yang Y. Nitrogen species and microbial community coevolution along groundwater flowpath in the southwest of Poyang Lake area, China. CHEMOSPHERE 2023; 329:138627. [PMID: 37031839 DOI: 10.1016/j.chemosphere.2023.138627] [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: 01/11/2023] [Revised: 04/02/2023] [Accepted: 04/04/2023] [Indexed: 05/03/2023]
Abstract
Nitrate and ammonia overload in groundwater can lead to eutrophication of surface water in areas where surface water is recharged by groundwater. However, this process remained elusive due to the complicated groundwater N cycling, which is governed by the co-evolution of hydrogeochemical conditions and N-cycling microbial communities. Herein, this process was studied along a generalized groundwater flowpath in Ganjing Delta, Poyang Lake area, China. From groundwater recharge to the discharge area near the lake, oxidation-reduction potential (ORP), NO3-N, and NO2-N decreased progressively, while NH3-N, total organic carbon (TOC), Fe2+, sulfide, and TOC/NO3- ratio accumulated in the lakeside samples. The anthropogenic influences such as sewage and agricultural activities drove the nitrate distribution, as observed by Cl- vs. NO3-/Cl- ratio and isotopic composition of nitrate. The hydrogeochemical evolution was intimately coupled with the changes in microbial communities. Variations in microbial community structures was significantly explained by Fe2+, NH3-N, and sulfide, while TOC/NO3- controlled the distribution of predicted N cycling gene. The absence of NH3-N in groundwater upstream was accompanied by the enrichment in Acinetobacter capable of nitrification and aerobic denitrification. These two processes were also supported by Ca2+ + Mg2+ vs. HCO3- ratio and isotopic composition of NO3-. The DNRA process downstream was revealed by both the presence of DNRA-capable microbes such as Arthrobacter and the isotopic composition of NH4+ in environments with high concentrations of NH3-N, TOC/NO3-, Fe2+, and sulfide. This coupled evolution of N cycling and microbial community sheds new light on the N biogeochemical cycle in areas where surface water is recharged by groundwater.
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Affiliation(s)
- Xianglong Chen
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
| | - Guangcai Wang
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China.
| | - Yizhi Sheng
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China.
| | - Fu Liao
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
| | - Hairu Mao
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
| | - Bo Li
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
| | - Hongyu Zhang
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
| | - Zhiyuan Qiao
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
| | - Jiahui He
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
| | - Yingxue Liu
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
| | - Yilun Lin
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
| | - Ying Yang
- State Key Laboratory of Biogeology and Environmental Geology & MOE Key Laboratory of Groundwater Circulation and Environment Evolution, China University of Geosciences, Beijing, 100083, PR China; School of Water Resources and Environment, China University of Geosciences, Beijing, 100083, PR China
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Han LL, Wang H, Ge L, Xu MN, Tang JM, Luo L, Li P, Kao SJ. Transition of source/sink processes and fate of ammonium in groundwater along with redox gradients. WATER RESEARCH 2023; 231:119600. [PMID: 36680827 DOI: 10.1016/j.watres.2023.119600] [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: 10/06/2022] [Revised: 12/20/2022] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
Ammonium (NH4+) retention/removal processes in groundwater are of great interest because of the continuous increase in nitrogenous compound loading due to anthropogenic activities. However, the transition of multiple co-occurring transformation processes that determine the fate of NH4+ in groundwater along a redox gradient remains underexplored. We selected a high nitrogen (N) groundwater system in the western Hetao Basin, China, to identify and quantify NH4+ source and sink processes, including mineralization, dissimilatory nitrate reduction to ammonium (DNRA), nitrification, and anammox, to better understand the dynamics of NH4+. Based on redox-sensitive parameters, that is, the oxidation-reduction potential (ORP) and NH4+ and nitrate (NO3-) contents, etc., the groundwater system was classified into three zones from upstream to downstream: zone I (oxidizing), zone II (moderately reducing), and zone III (strongly reducing). Using the 15N tracing technique, we found that NH4+ was mainly produced by mineralization while < 2% was produced by DNRA throughout the study area. Mineralization increased downstream because the supply of biodegradable N-containing compounds was augmented, which created a strong redox gradient to host a serial reaction chain. In zone I, NH4+ was mainly transferred to NO3- via nitrification, whereas in zones II and III, NH4+ was mainly transferred to N2 via anammox. The average NH4+ production/consumption ratios (P/C) in zones I, II, and III were 0.7, 6.9, and 51.1, respectively. Obviously, the NH4+ purification ability can only exceed the supply under aerobic conditions, thus suggesting that NH4+ will accumulate without limitation and be retained in strongly reducing groundwater. The situation of NH4+ accumulation would deteriorate over space and time in groundwater as human activities increase without an additional artificial supply of oxidants. The results provide mechanistic insights for quantitatively comprehending the dynamics and fate of NH4+ in groundwater, shedding light on groundwater NH4+ mitigation techniques.
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Affiliation(s)
- Li-Li Han
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Helin Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan, China
| | - Lianghao Ge
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Min Nina Xu
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou, China
| | - Jin-Ming Tang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Li Luo
- State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou, China
| | - Ping Li
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China; Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science, China University of Geosciences, Wuhan, China.
| | - Shuh-Ji Kao
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China; State Key Laboratory of Marine Resources Utilization in South China Sea, Hainan University, Haikou, China.
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Zhao Y, Chen Z, Wang Q, Zhang C, Ji M. A new insight to explore toxic Cd(II) affecting denitrification: Reaction kinetic, electron behavior and microbial community. CHEMOSPHERE 2022; 305:135419. [PMID: 35752314 DOI: 10.1016/j.chemosphere.2022.135419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 05/24/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
Denitrification process is a crucial step in nitrogen removal and is more vulnerable to external shocks due to the fact that anoxic process is always located before aerobic process in conventional sewage treatment. This study aims to elaborate the nitrogen conversion characteristics by investigating denitrification kinetics, electron behavior and microbial community under Cd(II) shock. Reaction kinetics showed that 10 mg/L of Cd(II) accelerated nitrate reduction rate by 52.29% but 80 mg/L of Cd(II) severely decelerated it by 95.41% with the accumulation of nitrite. High concentration of COD (C/N = 10.4) in the system caused by Cd(II) disrupting the integrity of cell membrane (lactate dehydrogenase increased by 328.7%) was proved to induce occurrence of Dissimilatory Nitrate Reduction to Ammonia (DNRA). The electron transport system activity (ETSA), electron consumption and electron distribution were combined to reveal the electron behavior regulated by Cd(II). The electron ratio of nitrate reductase to nitrite reductase increased from 1.48 (control) to 3.91 and 3.52 (40 and 80 mg/L of Cd(II)) indicated the electrons allocating tendency and further explained the nitrite accumulation. High concentration of Cd(II) also decreased ETSA by weakening the physiological activities of flavin adenine dinucleotide, flavin mononucleotide and cytochrome c or hindered the microbes to secrete these electron carriers. Furthermore, Cd(II) inhibited dominant bacteria genera containing napA gene (Azospirillum and Thauera) and nirS gene (unclassified_c_Betaproteobacteria). Enterobacteriaceae family was found to dominate the DNRA process.
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Affiliation(s)
- Yingxin Zhao
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China.
| | - Zhihui Chen
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China
| | - Qian Wang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China
| | - Chenggong Zhang
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China
| | - Min Ji
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300350, PR China
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Richa A, Touil S, Fizir M. Recent advances in the source identification and remediation techniques of nitrate contaminated groundwater: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 316:115265. [PMID: 35576711 DOI: 10.1016/j.jenvman.2022.115265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 05/05/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
Researchers have long been committed to identify nitrate sources in groundwater and to develop an advanced technique for its remediation because better apply remediation solution and management of water quality is highly dependent on the identification of the NO3- sources contamination in water. In this review, we systematically introduce nitrate source tracking tools used over the past ten years including dual isotope and multi isotope techniques, water chemistry profile, Bayesian mixing model, microbial tracers and land use/cover data. These techniques can be combined and exploited to track the source of NO3- as mineral or organic fertilizer, sewage, or atmospheric deposition. These available data have significant implications for making an appropriate measures and decisions by water managers. A continuous remediation strategy of groundwater was among the main management strategies that need to be applied in the contaminated area. Nitrate removal from groundwater can be accomplished using either separation or reduction based process. The application of these processes to nitrate removal is discussed in this review and some novel methods were presented for the first time. Moreover, the advantages and limitations of each approach are critically summarized and based on our own understanding of the subject some solutions to overcomes their drawbacks are recommended. Advanced techniques are capable to attain significantly higher nitrate and other co-contaminants removal from groundwater. However, the challenges of by-products generation and high energy consumption need to be addressed in implementing these technologies for groundwater remediation for potable use.
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Affiliation(s)
- Amina Richa
- University of Djilali Bounaama, Khemis Miliana, Algeria.
| | - Sami Touil
- University of Djilali Bounaama, Khemis Miliana, Algeria.
| | - Meriem Fizir
- Laboratoire de Valorisation des Substances Naturelles, Université Djilali Bounaâma, Khemis Miliana, Algeria.
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Chen A, Zhang D, Wang H, Cui R, Khoshnevisan B, Guo S, Wang P, Liu H. Shallow groundwater fluctuation: An ignored soil N loss pathway from cropland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 828:154554. [PMID: 35302037 DOI: 10.1016/j.scitotenv.2022.154554] [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: 10/29/2021] [Revised: 03/06/2022] [Accepted: 03/09/2022] [Indexed: 06/14/2023]
Abstract
Nitrogen (N) pollution originating from agricultural land is among the major threats to shallow groundwater (SG). Soil N losses due to the SG table fluctuation are neglected, although a large number of studies have been conducted to evaluate N losses through leaching and runoff. Herein, the characteristics of N losses driven by SG table fluctuation were investigated using the microcosm experiment and surveyed data from the croplands around Erhai Lake. According to the results achieved, the total N (TN) loss mainly occurred during the initial 12 days when the soil was flooded, then presented N immobilized by soil and finally, basically balanced between influent and effluent after 50 days. The results demonstrated that 1.7% of the original soil TN storage (0-100 cm) was lost. The alternation of drying and flooding could greatly increase TN loss up to 1086 kg hm-2, which was 2.72 times as much as that of continuous flooding flow. The amount of soil N losses to groundwater was closely related to the soil profile biochemical characteristics (water content, soil microbial immobilization, mineralization, nitrification, and denitrification processes). Soil N loss from crop fields driven by SG table fluctuation is 26 and 6 times of the runoff and leaching losses, respectively, while the soil N loss from the vegetable fields is 33 and 4 times of the runoff and leaching losses. The total amount of N losses from the croplands around the Erhai Lake caused by flooding of shallow groundwater (SG) in 2016 was estimated at 3506 Mg. The estimations showed that N losses would decrease by 16% if vegetables are replaced with staple food crops. These results imply that the adjustment of the planting structure was the key measure to reduce soil N storage and mitigate groundwater contamination.
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Affiliation(s)
- Anqiang Chen
- Agricultural Environment and Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming 650201, China
| | - Dan Zhang
- College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China
| | - Hongyuan Wang
- Key Laboratory of Non-point Source Pollution Control, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Rongyang Cui
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Conservancy, Chengdu 610041, Sichuan Province, China
| | - Benyamin Khoshnevisan
- Key Laboratory of Non-point Source Pollution Control, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Department of Chemical Engineering, Biotechnology and Environmental Technology, University of Southern Denmark, Denmark
| | - Shufang Guo
- Agricultural Environment and Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming 650201, China
| | - Panlei Wang
- Agricultural Environment and Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming 650201, China
| | - Hongbin Liu
- Key Laboratory of Non-point Source Pollution Control, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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10
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Spatial-Temporal Distribution, Morphological Transformation, and Potential Risk of Dissolved Inorganic Nitrogen in the Contaminated Unconfined Aquifer from a Retired Nitrogenous Fertilizer Plant. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19138022. [PMID: 35805679 PMCID: PMC9265358 DOI: 10.3390/ijerph19138022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 12/10/2022]
Abstract
The accumulation of nitrogen in groundwater in the industrial plots, especially the high ammonium, can result in a serious threat to the groundwater system in the urban area. This study monitored the dissolved inorganic nitrogen (DIN) of the polluted groundwater four times in one year in a retired nitrogenous fertilizer plant site with a production history of nearly 40 years, to analyze the spatial-temporal characteristics of DIN species (NH4+-N, NO3−-N, and NO2−-N) and the effects of groundwater environment on their transfer and transformation. The results showed that NH4+-N (<0.025 to 1310 mg/L) was the main DIN species (61.38−76.80%) with low mobility, whereas the concentration of NO3−-N and NO2−-N was 0.15−146 mg/L and <0.001−12.4 mg/L, accounting for 22.34−36.07% and 0.53−2.83% of total DIN, respectively. The concentration and proportion of NO3−-N and NO2−-N showed an upward trend with time, posing a threat to the safety of surrounding groundwater, and their high spatial-temporal variation was related to the morphological transformation and the transport. In the wet season, the pH and redox condition benefited the nitrification, and NO3−-N easily migrated from the deep soil solution to groundwater, hence the NO3−-N can be accumulated. Therefore, the analysis of species and behaviors of DIN in shallow groundwater is indispensable for environmental risk assessment.
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11
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Upreti K, Rivera-Monroy VH, Maiti K, Giblin AE, Castañeda-Moya E. Dissimilatory nitrate reduction to ammonium (DNRA) is marginal relative to denitrification in emerging-eroding wetlands in a subtropical oligohaline and eutrophic coastal delta. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 819:152942. [PMID: 35007602 DOI: 10.1016/j.scitotenv.2022.152942] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/18/2021] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
Nitrate (NO3-) and ammonium (NH4+) are reactive nitrogen (Nr) forms that can exacerbate eutrophication in coastal regions. NO3- can be lost to the atmosphere as N2 gas driven by direct denitrification, coupled nitrification-denitrification and annamox or retained within the ecosystems through conversion of NO3- to NH4+ via dissimilatory nitrate reduction to ammonium (DNRA). Denitrification and DNRA are competitive pathways and hence it is critical to evaluate their functional biogeochemical role. However, there is limited information about the environmental factors driving DNRA in oligohaline habitats, especially within deltaic regions where steep salinity gradients define wetland spatiotemporal distribution. Here we use the Isotope Pairing Technique to evaluate the effect of temperature (10, 20, 30 °C) and in situ soil/sediment organic matter (OM%) on total denitrification (Dtotal = direct + coupled nitrification) and DNRA rates in oligohaline forested/marsh wetlands soils and benthic sediment habitats at two sites representing prograding (Wax Lake Delta, WLD) and eroding (Barataria- Lake Cataouatche, BLC) deltaic stages in the Mississippi River Delta Plain (MRDP). Both sites receive MR water with high NO3- (>40 μM) concentrations during the year via river diversions. Denitrification rates were significantly higher (range: 18.0 ± 0.4-113.0 ± 10.6 μmol m-2 h-1) than DNRA rates (range: 0.7 ± 0.2-9.2 ± 0.3 μmol m-2 h-1). Therefore, DNRA represented on average < 10% of the total NO3- reduction (DNRA + Dtotal). Unlike denitrification, DNRA showed no consistent response to temperature. These results indicate that DNRA in wetland soils and benthic sediment is not a major nitrogen transformation in oligohaline regions across the MRDP regardless of wide range of OM% content in these eroding and prograding delta lobes.
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Affiliation(s)
- Kiran Upreti
- Department of Oceanography and Coastal Sciences, College of the Coast and Enviroment, Louisiana State University, Baton Rouge, LA 70808, USA
| | - Victor H Rivera-Monroy
- Department of Oceanography and Coastal Sciences, College of the Coast and Enviroment, Louisiana State University, Baton Rouge, LA 70808, USA.
| | - Kanchan Maiti
- Department of Oceanography and Coastal Sciences, College of the Coast and Enviroment, Louisiana State University, Baton Rouge, LA 70808, USA
| | - Anne E Giblin
- The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA
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12
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Patterns and Drivers of Groundwater and Stream Nitrate Concentrations in Intensively Managed Agricultural Catchments. WATER 2022. [DOI: 10.3390/w14091388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The environmental loss of nitrogen in agricultural landscapes has pervasive consequences, including human health implications, eutrophication, loss of habitat biodiversity and greenhouse gas emissions. The efficacy of mitigation strategies designed to control or prevent nitrate contamination of waterbodies requires an understanding of catchment scale pressures and processes. Groundwater and stream nitrate concentrations fluctuate over temporal scales ranging from the daily to the decadal. Identifying spatiotemporal trends and dominant drivers of nitrate in water is challenging as the drivers are intertwined. The effects of agronomic, meteorological and hydrogeological drivers on groundwater and stream nitrate were investigated over seven years in two well-drained agricultural catchments, dominated by tillage and grassland farming, respectively. A significant positive temporal trend in nitrate concentration was observed in the tillage catchment, whereas no long-term trend was observed in the grassland catchment. Agronomic, meteorological and hydrogeological factors were significantly related to temporal nitrate changes across both catchments. Clearly identifying the drivers influencing temporal changes in nitrate concentrations is critical to improving water quality. The study highlighted that to reduce groundwater nitrate levels in areas of high risk (thin soils, low clay content and shallow groundwater), nitrogen applications need to be reduced and/or tailored, particularly at times of restricted crop growth.
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13
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Liu Y, Xin J, Wang Y, Yang Z, Liu S, Zheng X. Dual roles of dissolved organic nitrogen in groundwater nitrogen cycling: Nitrate precursor and denitrification promoter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 811:151375. [PMID: 34740651 DOI: 10.1016/j.scitotenv.2021.151375] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/02/2021] [Accepted: 10/28/2021] [Indexed: 06/13/2023]
Abstract
Dissolved organic nitrogen (DON) has been reported to be prevalent in groundwater worldwide. Owing to the diversity of physicochemical properties, DON plays complex roles in nitrogen cycling processes, which has further implications for nitrate (NO3--N) pollution control in groundwater. To characterize these crucial roles, we investigated the effects of three types of DON (amino acid, urea, and protein) on NO3--N accumulation in groundwater with a 60-day incubation experiment and established quantitative correlations between microbial indicators (bacterial communities and nitrogen functional genes) and nitrogen content. The results showed that NO3--N content increased by 30.3% and 38.8% and was strongly correlated with the presence of amino acid and urea; however, the addition of protein did not lead to an additional increase in NO3--N, possibly due to different extents of mineralization and denitrification caused by different types of DON. Molecular biological experiments demonstrated that Nitrospira (1.8-3.2%) contributed to nitrification in the urea treatment, whereas Arthrobacter (2.0-6.9%) and Thermomonas (11.9-13.1%) were key communities controlling denitrification in amino acid and protein treatments. amoA and nxrA were continuously enriched in the presence of urea; however, amino acid and protein were strongly correlated with napA-dominated and narG-dominated denitrification processes, with the path coefficient - 2.912 and - 2.450 respectively. Combined analyses showed that DON with distinct physicochemical properties played dual roles (NO3--N precursor and denitrification promoter) to varying degrees, which could have significant impacts on NO3--N accumulation in groundwater. This study may provide guidance for environmental risk evaluation and control strategies for NO3--N pollution in groundwater.
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Affiliation(s)
- Yang Liu
- Key Laboratory of Marine Environment Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Jia Xin
- Key Laboratory of Marine Environment Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
| | - Yuan Wang
- Key Laboratory of Marine Environment Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Zhixiang Yang
- Key Laboratory of Marine Environment Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Shixuan Liu
- Key Laboratory of Marine Environment Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Xilai Zheng
- Key Laboratory of Marine Environment Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
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14
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Handler AM, Suchy AK, Grimm NB. Denitrification and DNRA in Urban Accidental Wetlands in Phoenix, Arizona. JOURNAL OF GEOPHYSICAL RESEARCH. BIOGEOSCIENCES 2022; 127:1-15. [PMID: 35251875 PMCID: PMC8896236 DOI: 10.1029/2021jg006552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) both require low oxygen and high organic carbon conditions common in wetland ecosystems. Denitrification permanently removes nitrogen from the ecosystem as a gas while DNRA recycles nitrogen within the ecosystem via production of ammonium. The relative prevalence of denitrification versus DNRA has implications for the fate of nitrate in ecosystems. Unplanned and unmanaged urban accidental wetlands in the Salt River channel near downtown Phoenix, Arizona, USA receive high nitrate relative to non-urban wetlands and have a high capacity for denitrification, but unknown capacity for DNRA. We conducted in-situ push-pull tests with isotopically labelled nitrate to measure denitrification and DNRA rates in three of the dominant vegetative patch types in these urban accidental wetlands. DNRA accounted for between 2 and 40% of nitrate reduction (DNRA plus denitrification) with the highest rates measured in patches of Ludwigia peploides compared to Typha spp. and non-vegetated patches. The wetland patches were similar with respect to dissolved organic carbon concentration but may have differed in carbon lability or strength of reducing conditions due to a combination of litter decomposition and oxygen supply via diffusion and aerenchyma. The ratio of DNRA to denitrification was negatively correlated with nitrate concentration, indicating that DNRA may become a more important pathway for nitrate attenuation at low nitrate concentration. Although DNRA was generally lower than denitrification, this pathway was an important component of nitrate attenuation within certain patches in these unmanaged urban accidental wetlands.
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Affiliation(s)
- Amalia M Handler
- School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85287
| | - Amanda K Suchy
- School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85287
| | - Nancy B Grimm
- School of Life Sciences, Arizona State University, PO Box 874501, Tempe, AZ 85287
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15
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Cui R, Zhang D, Liu G, Wang P, Chen A, Wang H. Shift of lakeshore cropland to buffer zones greatly reduced nitrogen loss from the soil profile caused by the interaction of lake water and shallow groundwater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 803:150093. [PMID: 34525740 DOI: 10.1016/j.scitotenv.2021.150093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 08/18/2021] [Accepted: 08/29/2021] [Indexed: 06/13/2023]
Abstract
The interaction of lake water (LW) and shallow groundwater (SGW) accelerates nitrogen (N) loss from the soil profile in the lakeshore cropland, and cropland buffer zone (CBZ) significantly inhibits N loss in this area. Here, characteristics of N loss and transformations driven by SGW and LW interactions were explored using microcosmic experiments, and N loss was estimated using in situ monitoring data before and after the construction of the CBZ along the west bank of Erhai Lake. The results indicated that NO3--N, dissolved organic N and total dissolved N sustained the main N losses in the soil, and the organic N was responsible for the main N loss in the effluent. The lower total nitrogen (TN) concentrations of SGW in this area, the greater the soil N loss. Moreover, N total loss from the 100 cm soil profile in the control check was 1.8 times that in the simulated SGW treatment. We found that nitrification, denitrification and anammox driven by the microbial community and N functional genes were the key processes leading to N loss. The effluent N (3.64%) and gaseous N (0.32%) loss ratios in the cropland for continuously growing vegetables (CGV) were much higher than that in the CBZ (1.07% of effluent N and 0.25% of gaseous N loss ratios). If a 100 m wide and 48 km long area of lakeshore cropland is CGV, an increase by 47% is projected by 2030 compared with the N loss in 2020. But this region was built as a 100 m wide CBZ or 50 m wide CBZ + 50 m wide CGV after 2019, N loss will be reduced by 87% and 44% in 2030 compared with the N loss in CGV. The results implied that restoring a suitable width of CBZ can significantly reduce N loss.
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Affiliation(s)
- Rongyang Cui
- College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China; Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Conservancy, Chengdu 610041, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dan Zhang
- College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China
| | - Gangcai Liu
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Chinese Academy of Sciences, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences and Ministry of Water Conservancy, Chengdu 610041, China
| | - Panlei Wang
- Agricultural Environment and Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming 650201, China
| | - Anqiang Chen
- Agricultural Environment and Resources Institute, Yunnan Academy of Agricultural Sciences, Kunming 650201, China.
| | - Hongyuan Wang
- Key Laboratory of Non-point Source Pollution Control, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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16
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Denitrification in Intrinsic and Specific Groundwater Vulnerability Assessment: A Review. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app112210657] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several groundwater vulnerability methodologies have been implemented throughout the years to face the increasing worldwide groundwater pollution, ranging from simple rating methodologies to complex numerical, statistical, and hybrid methods. Most of these methods have been used to evaluate groundwater vulnerability to nitrate, which is considered the major groundwater contaminant worldwide. Together with dilution, the degradation of nitrate via denitrification has been acknowledged as a process that can reduce reactive nitrogen mass loading rates in both deep and shallow aquifers. Thus, denitrification should be included in groundwater vulnerability studies and integrated into the various methodologies. This work reviewed the way in which denitrification has been considered within the vulnerability assessment methods and how it could increase the reliability of the overall results. Rating and statistical methods often disregard or indirectly incorporate denitrification, while numerical models make use of kinetic reactions that are able to quantify the spatial and temporal variations of denitrification rates. Nevertheless, the rating methods are still the most utilized, due to their linear structures, especially in watershed studies. More efforts should be paid in future studies to implement, calibrate, and validate user-friendly vulnerability assessment methods that are able to deal with denitrification capacity and rates at large spatial and temporal scales.
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17
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Zhang M, Wang ZJ, Huang JC, Sun S, Cui X, Zhou W, He S. Salinity-driven nitrogen removal and its quantitative molecular mechanisms in artificial tidal wetlands. WATER RESEARCH 2021; 202:117446. [PMID: 34314924 DOI: 10.1016/j.watres.2021.117446] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 06/30/2021] [Accepted: 07/14/2021] [Indexed: 06/13/2023]
Abstract
The present study investigated the performance in nitrogen removal and associated nitrogen transformation processes in seven mesocosms fed with saline water (0‰ to 30‰) to simulate tidal flow constructed wetlands (TF CWs). The highly effective and steady removal of NH4+-N (84.74% averagely) was obtained at various salinities, while the rates varied from 6.34% to 89.19% and 22.54% to 87.48% for NO3--N and total nitrogen (TN), respectively. Overall, nitrogen removal efficiencies were greater at lower salinities. Molecular biological analyses verified the co-occurrence of dissimilatory nitrate reduction to ammonium (DNRA), denitrification, anaerobic ammonium oxidation (anammox) and nitrification in the mesocosms, reportedly contributing to nitrogen removal in TF CWs. The absolute copy numbers of nitrogen functional genes and total bacterial 16S rRNA were 2.54 × 103-7.35 × 107 and 3.21 × 107-7.82 × 109 copies g-1 dg (dry gravel), respectively, with the dominant phyla, i.e., Chloroflexi, Proteobacteria, Actinobacteriota, Cyanobacteria, and Firmicutes, accounting for over 80% of the sequences. The relative abundances of the genera related to nitrification and dissimilatory nitrate reduction processes, i.e., denitrification, anammox and DNRA, varied from 0.16% to 0.89% and from 3.66% to 11.59%, respectively, while quantitative relationships confirmed NH4+-N transformation rate was jointly controlled by amoA, hzsB, nxrA and nrfA, and NO3--N removal rate by nirS, nosZ, narG, qnorB and nxrA. These findings may shed light on quantitative molecular mechanisms for nitrogen removal in TF CWs for the saline water treatment, providing a sustainable solution to nitrogen pollution problem in the estuary ecosystem.
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Affiliation(s)
- Manping Zhang
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China
| | - Zi-Jing Wang
- Department of Environmental Engineering, National Cheng Kung University, Tainan City 701, Taiwan
| | - Jung-Chen Huang
- Department of Environmental Engineering, National Cheng Kung University, Tainan City 701, Taiwan.
| | - Shanshan Sun
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China
| | - Xijun Cui
- China-UK Low Carbon College, Shanghai Jiao Tong University, Shanghai 201306, PR China
| | - Weili Zhou
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China
| | - Shengbing He
- School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China
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18
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Mander Ü, Tournebize J, Espenberg M, Chaumont C, Torga R, Garnier J, Muhel M, Maddison M, Lebrun JD, Uher E, Remm K, Pärn J, Soosaar K. High denitrification potential but low nitrous oxide emission in a constructed wetland treating nitrate-polluted agricultural run-off. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 779:146614. [PMID: 34030255 DOI: 10.1016/j.scitotenv.2021.146614] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 03/12/2021] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
Constructed wetlands (CW) can efficiently remove nitrogen from polluted agricultural run-off, however, a potential caveat is nitrous oxide (N2O), a harmful greenhouse gas and stratospheric ozone depleter. During five sampling campaigns, we measured N2O fluxes from a 0.53 ha off-stream CW treating nitrate-rich water from the intensively fertilized watershed in Rampillon, France, using automated chambers with a quantum cascade laser system, and manual chambers. Sediment samples were analysed for potential N2 flux using the HeO2 incubation method. Both inlet nitrate (NO3-) concentrations and N2O emission varied significantly between the seasons. In the Autumn and Winter inlet concentrations were about 11 mg NO3--N L-1, and < 6.5 mg NO3--N L-1 in the Spring and Summer. N2O emission was highest in the Autumn (mean ± standard error: 9.7 ± 0.2 μg N m-2 h-1) and lowest in the Summer (wet period: 0.2 ± 0.3 μg N m-2 h-1). The CW was a very weak source of N2O emitting 0.32 kg N2O-N ha-1 yr-1 and removing around 938 kg NO3--N ha-1 yr-1, the ratio of N2O-N emitted to NO3--N removed was 0.033%. The automated and manual chambers gave similar results. From the potential N2O formation in the sediment, only 9% was emitted to the atmosphere, the average N2 N 2O ratio was high: 89:1 for N2-Npotential: N2O-Npotential and 1353:1 for N2-Npotential: N2O-Nemitted. These results indicate complete denitrification. The focused principal component analysis showed strong positive correlation between the gaseous N2O fluxes and the following environmental factors: NO3--N concentrations in inlet water, streamflow, and nitrate reduction rate. Water temperature, TOC and DOC in the water and hydraulic residence time showed negative correlations with N2O emissions. Shallow off-stream CWs such as Rampillon may have good nitrate removal capacity with low N2O emissions.
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Affiliation(s)
- Ülo Mander
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia; UR 1462 HYCAR, University Paris Saclay, French National Institute for Agriculture, Food, and Environment (INRAE), Antony, France.
| | - Julien Tournebize
- UR 1462 HYCAR, University Paris Saclay, French National Institute for Agriculture, Food, and Environment (INRAE), Antony, France
| | - Mikk Espenberg
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Cedric Chaumont
- UR 1462 HYCAR, University Paris Saclay, French National Institute for Agriculture, Food, and Environment (INRAE), Antony, France
| | - Raili Torga
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | | | - Mart Muhel
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Martin Maddison
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Jérémie D Lebrun
- UR 1462 HYCAR, University Paris Saclay, French National Institute for Agriculture, Food, and Environment (INRAE), Antony, France
| | - Emmanuelle Uher
- UR 1462 HYCAR, University Paris Saclay, French National Institute for Agriculture, Food, and Environment (INRAE), Antony, France
| | - Kalle Remm
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Jaan Pärn
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| | - Kaido Soosaar
- Department of Geography, Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
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19
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Cao C, Huang J, Yan CN, Zhang XX, Ma YX. Impacts of Ag and Ag 2S nanoparticles on the nitrogen removal within vertical flow constructed wetlands treating secondary effluent. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 777:145171. [PMID: 33676207 DOI: 10.1016/j.scitotenv.2021.145171] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/29/2020] [Accepted: 01/10/2021] [Indexed: 06/12/2023]
Abstract
In this study, the effects of silver (Ag NPs) and sliver sulfide nanoparticles (Ag2S NPs) on nitrogen removal and nitrogen functional microbes in constructed wetlands were investigated. The obtained results demonstrated that inhibition extent on nitrogen removal relied on NPs types and high concentrations NPs showed higher negative effects. 0.5 mg/L Ag NPs had no influence on NH4+-N removal, amoA and nxrA gene copies, whereas Ag2S NPs and Ag+ decreased NH4+-N removal by reducing abundances of nitrifying genes. The concentrations of NO3--N and TN in all 0.5 mg/L obviously increased compared with control, resulting from decreasing functional genes and denitrifying bacteria. And 0.5 mg/L Ag NPs exhibited largest inhibitory effects, with the highest NO3--N effluent concentrations. 2 mg/L Ag NPs decreased NH4+-N removal, but adverse effects gradually vanished with extension of time, whereas both Ag2S NPs and Ag+ at 2 mg/L influenced NH4+-N transformation and decreased the abundance of amoA and nxrA genes and the AOB Nitrosomonas in CWs. Moreover, 2 mg/L of Ag NPs reduced NO3--N removal by decreasing abundance of nirS and key denitrifying bacteria. To sum up, the inhibition mechanisms concluded from current results were possibly in that Ag NPs exhibited nanotoxicity rather than ionic toxicity.
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Affiliation(s)
- Chong Cao
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 211189, China
| | - Juan Huang
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 211189, China.
| | - Chun-Ni Yan
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 211189, China
| | - Xin-Xin Zhang
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 211189, China
| | - Yi-Xuan Ma
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 211189, China
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20
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Community Composition and Spatial Distribution of N-Removing Microorganisms Optimized by Fe-Modified Biochar in a Constructed Wetland. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18062938. [PMID: 33805608 PMCID: PMC8000742 DOI: 10.3390/ijerph18062938] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/07/2021] [Accepted: 03/09/2021] [Indexed: 11/17/2022]
Abstract
Microbial nitrogen (N) removal capability can be significantly enhanced in a horizontal subsurface flow constructed wetland (HSCW) amended by Fe-modified biochar (FeB). To further explore the microbiological mechanism of FeB enhancing N removal, nirS- and nirK-denitrifier community diversities, as well as spatial distributions of denitrifiers and anaerobic ammonium oxidation (anammox) bacteria, were investigated in HSCWs (C-HSCW: without biochar and FeB; B-HSCW: amended by biochar; FeB-HSCW: amended by FeB) treating tailwater from a wastewater treatment plant, with C-HSCW without biochar and FeB and B-HSCW amended by biochar as control. The community structures of nirS- and nirK-denitrifiers in FeB-HSCW were significantly optimized for improved N removal compared with the two other HSCWs, although no significant differences in their richness and diversity were detected among the HSCWs. The spatial distributions of the relative abundance of genes involved in denitrification and anammox were more heterogeneous and complex in FeB-HSCW than those in other HSCWs. More and larger high-value patches were observed in FeB-HSCW. These revealed that FeB provides more appropriate habitats for N-removing microorganisms, which can prompt the bacteria to use the habitats more differentially, without competitive exclusion. Overall, the Fe-modified biochar enhancement of the microbial N-removal capability of HSCWs was a result of optimized microbial community structures, higher functional gene abundance, and improved spatial distribution of N-removing microorganisms.
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Cao C, Huang J, Yan CN, Ma YX, Xiao J, Zhang XX. Comparative analysis of upward and downward vertical flow constructed wetlands on the nitrogen removal and functional microbes treating wastewater containing Ag nanoparticles. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 278:111573. [PMID: 33137687 DOI: 10.1016/j.jenvman.2020.111573] [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: 07/27/2020] [Revised: 10/23/2020] [Accepted: 10/24/2020] [Indexed: 06/11/2023]
Abstract
This study investigated impacts of silver nanoparticles (AgNPs) on nitrogen removal within constructed wetlands (CWs) with different flow directions. The obtained results showed that addition of AgNPs at 0.5 and 2 mg/L significantly inhibited NH4+-N removal, resulting from lower abundances of functional genes (amoA and nxrA) within CWs. And higher abundances of amoA and nxrA genes at 0.5 mg/L were observed in downward flow CW, leading to better NH4+-N removal, compared to upward flow CW. Besides, nitrifying genes amoA and nxrA in upward flow CW at 2.0 mg/L exhibited higher than downward flow CW, explaining better NH4+-N removal in upward flow CW. 0.5 mg/L AgNPs significantly declined NO3--N and TN removal, resulted from decreasing abundances of nirK, nirS and nosZ. In contrast, abundances of nirK, nirS and nosZ genes had slightly lower or higher than before adding AgNPs in upward flow CW, leading to lower NO3--N and TN effluent concentrations. High throughput sequencing also indicated the changes of functional bacterial community after exposing to AgNPs.
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Affiliation(s)
- Chong Cao
- Dept. of Municipal Engineering, School of Civil Engineering, Southeast University, No. 2 Southeast University Road, Nanjing, Jiangsu Province, 211189, China
| | - Juan Huang
- Dept. of Municipal Engineering, School of Civil Engineering, Southeast University, No. 2 Southeast University Road, Nanjing, Jiangsu Province, 211189, China.
| | - Chun-Ni Yan
- Dept. of Municipal Engineering, School of Civil Engineering, Southeast University, No. 2 Southeast University Road, Nanjing, Jiangsu Province, 211189, China
| | - Yi-Xuan Ma
- Dept. of Municipal Engineering, School of Civil Engineering, Southeast University, No. 2 Southeast University Road, Nanjing, Jiangsu Province, 211189, China
| | - Jun Xiao
- Dept. of Municipal Engineering, School of Civil Engineering, Southeast University, No. 2 Southeast University Road, Nanjing, Jiangsu Province, 211189, China
| | - Xin-Xin Zhang
- Dept. of Municipal Engineering, School of Civil Engineering, Southeast University, No. 2 Southeast University Road, Nanjing, Jiangsu Province, 211189, China
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Li Q, Bu C, Ahmad HA, Guimbaud C, Gao B, Qiao Z, Ding S, Ni SQ. The distribution of dissimilatory nitrate reduction to ammonium bacteria in multistage constructed wetland of Jining, Shandong, China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:4749-4761. [PMID: 32951167 DOI: 10.1007/s11356-020-10709-z] [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: 03/01/2020] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
Dissimilatory nitrate reduction to ammonium (DNRA) is an important process of nitrate reduction in the environment. The distribution of DNRA bacteria and the relationships with environmental factors in multistage constructed wetland were investigated in this study. The quantitative real-time polymerase chain reaction analysis showed that the abundance of DNRA bacteria at all sites ranged from 2.10 × 1010 to 1.10 × 1011 copies/g of dry sediments. The Anaeromyxobacter (belong to Deltaproteobacteria) was the most abundant DNRA bacteria at all sites. The Geobater known as DNRA bacteria was also identified in this study. The abundances of DNRA bacteria, denitrifying bacteria, and anammox bacteria were conspicuously negatively correlated with Eh and positively correlated with the NO3--N removal efficency by statistical analysis.
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Affiliation(s)
- Qianxia Li
- State Key Laboratory of Petroleum Pollution Control, Beijing, 102206, People's Republic of China
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, No. 72 Binhai Road, Qingdao, 266237, Shandong, People's Republic of China
| | - Cuina Bu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, No. 72 Binhai Road, Qingdao, 266237, Shandong, People's Republic of China
| | - Hafz Adeel Ahmad
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, No. 72 Binhai Road, Qingdao, 266237, Shandong, People's Republic of China
| | - Christophe Guimbaud
- Laboratoire de Physique et de Chimie de l'Environnement et de l'Espace (LPC2E), CNRS et Université d'Orléans (UMR 7328), 45071, Orléans Cedex 2, France
| | - Baoyu Gao
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, No. 72 Binhai Road, Qingdao, 266237, Shandong, People's Republic of China
| | - Zhuangming Qiao
- Shandong Meiquan Environmental Protection Technology Co., Ltd., Jinan, People's Republic of China
| | - Shaowu Ding
- Shandong Wanhao Fertilizer Co., Ltd., Jinan, People's Republic of China
| | - Shou-Qing Ni
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, No. 72 Binhai Road, Qingdao, 266237, Shandong, People's Republic of China.
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Del Toro Farías A, Zurita Martínez F. Changes in the nitrification-denitrification capacity of pilot-scale partially saturated vertical flow wetlands (with corncob in the free-drainage zone) after two years of operation. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2020; 23:829-836. [PMID: 33349025 DOI: 10.1080/15226514.2020.1859987] [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: 06/12/2023]
Abstract
This six-month study aimed to evaluate the removal of total nitrogen (TN) in two duplicated partially saturated (PS) vertical flow (VF) wetlands added with corncob in two different heights of the free-drainage zone (FDZ) after two years in operation. Both PS VF wetlands efficiently removed organic matter measured as biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) as well as total suspended solids (TSS) achieving average mass removal efficiencies of 95.3%, 83.2% and 92.9%, respectively, in system I (SI) and 96.3%, 84.0% and 94.9%, respectively, in system II (SII); with no significant differences (p > 0.05) between the systems. Measurements of oxidation-reduction potential (ORP), dissolved oxygen (DO), pH and electrical conductivity (EC) showed suitable conditions in the saturated zone (SZ) of the systems for denitrification process. TN removal was similar in both systems (p > 0.05) (51.5% and 52.9% in SI and SII), and decreased in 15% with respect to the first year. This decrease was due to the lower denitrification capacity of the FDZ as a result of the reduction in the supply of biodegradable carbon by corncob. Denitrification occurred in the SZ, but not at a sufficient level to increase TN removal. NoveltyFirst, the use of lignocellulosic residues in partially saturated vertical wetlands to promote total nitrogen removal is very recent. Furthermore, to the best of our knowledge, this is the first study evaluating TN removal after two years of operation in this type of wetland. Therefore, this study allows us to better understand the function of these systems, in a relatively long term. Thanks to this study: it is possible to confirm that the main process of TN elimination is through the simultaneous nitrification-denitrification process in the free drainage zone (denitrification in the saturated zone is irrelevant) and that TN elimination decreases due to the reduction in carbon supply from the corn, in this area.
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Affiliation(s)
- Aarón Del Toro Farías
- Quality Environmental Laboratory, Centro Universitario de la Ciénega, University of Guadalajara, Ocotlán, México
| | - Florentina Zurita Martínez
- Quality Environmental Laboratory, Centro Universitario de la Ciénega, University of Guadalajara, Ocotlán, México
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Jia M, Winkler MKH, Volcke EIP. Elucidating the Competition between Heterotrophic Denitrification and DNRA Using the Resource-Ratio Theory. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:13953-13962. [PMID: 33095565 DOI: 10.1021/acs.est.0c01776] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Heterotrophic denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are two microbial processes competing for two shared resources, namely, nitrate and organic carbon (COD). Their competition has great implications for nitrogen loss, conservation, and greenhouse gas emissions. Nevertheless, a comprehensive and mechanistic understanding of the governing factors for this competition is still lacking. We applied the resource-ratio theory to study this competition and validated the theory with experimental data from continuous cultures reported in the literature. Based on this theory, we revealed that influent COD/N ratio alone was not sufficient to predict the competition outcome as the boundary values for different competition outcomes changed substantially with influent resource concentrations. The stoichiometry of the two processes was determinative for the boundaries, whereas the affinity for the shared resources (KS), maximum specific growth rate (μmax) of the two species, and the dilution rate had significant impacts as well but mainly at low influent resource concentrations (e.g., <100 μM nitrate). The presented approach allows for a more comprehensive understanding of the parameters controlling microbial competition. The computational comparison between continuous and batch cultures could explain seemingly conflicting experimental results as to the impact of the COD/N ratio. The results also include testable hypotheses and tools for understanding and managing the fate of nitrate in ecosystems, which could also be applied more widely to other species competing for two shared resources.
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Affiliation(s)
- Mingsheng Jia
- BioCo Research Group, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000 Gent, Belgium
| | - Mari K H Winkler
- Department of Civil and Environmental Engineering, University of Washington, Seattle, Washington 98195-2700, United States
| | - Eveline I P Volcke
- BioCo Research Group, Department of Green Chemistry and Technology, Ghent University, Coupure Links 653, 9000 Gent, Belgium
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Wang S, Reid MC. Kinetics of nitrous oxide mass transfer from porewater into root aerenchyma of wetland plants. JOURNAL OF ENVIRONMENTAL QUALITY 2020; 49:1717-1729. [PMID: 33169413 DOI: 10.1002/jeq2.20162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 09/21/2020] [Indexed: 06/11/2023]
Abstract
The creation and/or restoration of wetlands is an important strategy for controlling the release of reactive nitrogen (N) via denitrification, but there can be tradeoffs between enhanced denitrification and the production of nitrous oxide (N2 O), a potent greenhouse gas. A knowledge gap in current understanding of belowground wetland N dynamics is the role of gas transfer through the root aerenchyma system of wetland plants as a shortcut emission pathway for N2 O in denitrifying wetland soils. This investigation evaluates the significance of mass transfer into gas-filled root aerenchyma for the N2 O budget in wetland mesocosms planted with Sagittaria latifolia Willd. and Schoenoplectus acutus (Muhl. ex Bigelow) Á. Löve & D. Löve. Dissolved gas tracer push-pull tests with N2 O and the nonreactive gas tracers helium, sulfur hexafluoride, and ethane were used to estimate first-order rate constants for gas transfer into roots and microbial N2 O reduction and thereby disentangle the effects of root-mediated gas transport from microbial metabolism on N2 O balances in saturated soils. Root-mediated gas transport was estimated to account for up to 37% of overall N2 O removal from the wetland soils. Rates of microbial N2 O reduction varied widely based on the organic matter content of the soil media and served as a key control on the fraction of N2 O that transferred into roots. This research identifies transport through root aerenchyma as a potential shortcut pathway for N2 O emission from wetland soils and sediments and indicates that this process should be considered in both measurements and mechanistic modeling of belowground wetland N dynamics.
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Affiliation(s)
- Simiao Wang
- School of Civil and Environmental Engineering, Cornell Univ., Ithaca, NY, 14853, USA
| | - Matthew C Reid
- School of Civil and Environmental Engineering, Cornell Univ., Ithaca, NY, 14853, USA
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26
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Jahangir MMR, Fenton O, Carolan R, Harrington R, Johnston P, Zaman M, Richards KG, Müller C. Application of 15N tracing for estimating nitrogen cycle processes in soils of a constructed wetland. WATER RESEARCH 2020; 183:116062. [PMID: 32585388 DOI: 10.1016/j.watres.2020.116062] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 06/12/2020] [Accepted: 06/13/2020] [Indexed: 06/11/2023]
Abstract
Integrated Constructed Wetlands (ICW) area technology for the attenuation of contaminants such as organic carbon (C), nitrogen (N), phosphorous (P) and sulphur (S) in water coming from point or diffuse sources. Currently there is a lack of knowledge on the rates of gross N transformations in soils of the ICW bed leading to losses of reactive N to the environment. In addition, the kinetics of these processes need to be studied thoroughly for the sustainable use of ICW for removal of excessive N in the treatment of waste waters. Gross N transformation processes were quantified at two soil depths (0-15 and 30-45 cm) in the bed of a surface flow ICW using a 15N tracing approach. The ICW, located in Dunhill village at Waterford in Southeastern Ireland, receives 500 person equivalent waste waters containing large quantities of organic pollutants (ca. mean annual C, N, P and S contents of 240, 60, 5 and 73 mg L-1). Soil was removed from these depths in December 2014 and incubated anaerobically in the laboratory, with either 15N labeled ammonium (NH4+) or nitrate (NO3-), differentially labeled with 14NH415NO3 and 15NH414NO3 in parallel setups, enriched to 50 atm% 15N. Results showed that at both soil depths, NO3- production rates were small, which may have resulted in lower NO3- reduction by either denitrification or dissimilatory NO3- reduction to ammonium (DNRA). However, despite being low, the DNRA rates were greater than denitrification rates. Direct transformation of organic N to NO3-, without mineralization to NH4+, was a prevalent pathway of NO3- production accounting for 28-33% of the total NO3- production. Relative contribution of this process to the total N mineralization was negligible at depth 1 (0.01%) but dominant at depth 2 (99.7%). Total NO3-production to total immobilization of NH4+ and NO3- was very small (<0.50%) suggesting that ICW soils are not a source of NO3-. Despite a large potential of N immobilization existed at both the layers, relative N immobilization to the total N conversion was higher at depth 2 (ca. 2.2) than at depth 1 (ca. 1.5). The NH4+ desorption rate at 30-45 cm was high. However, immobilization in the recalcitrant and labile organic N pools was higher. Mineralization and immobilization of NH4+ processes showed that recalcitrant organic N was the predominant source in ICW soils whereas the labile organic N was comparatively small. Source apportionment of N2O production showed that the majority of the N2O produced through denitrification (ca. 92.5%) followed by heterotrophic nitrification (ca. 5.5%), co-denitrification (ca. 1.90%) and nitrification (0.20%). These results revealed that application of a detailed 15N tracing method can provide insights on the underlying processes of ecosystem based abundances of reactive N. A key finding of this study was that both investigated ICW layers were characterised by large N immobilization which restricts production of NO3- and further gaseous N losses.
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Affiliation(s)
- M M R Jahangir
- Department of Environment, Soils & Land Use, Teagasc Environment Research Centre, Johnstown Castle, Co., Wexford, Ireland; Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Dublin, 2, Ireland; Department of Soil Science, Bangladesh Agricultural University, Bangladesh
| | - O Fenton
- Department of Environment, Soils & Land Use, Teagasc Environment Research Centre, Johnstown Castle, Co., Wexford, Ireland
| | - R Carolan
- Agri-Food and Biosciences Institute, Newforge Lane, Belfast, BT9 5PX, Northern Ireland, UK
| | | | - P Johnston
- Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Dublin, 2, Ireland
| | - M Zaman
- Soil and Water Management & Crop Nutrition, Joint FAO/IAEA Division of Nuclear Techniques in Food & Agriculture, Vienna, Austria
| | - K G Richards
- Department of Environment, Soils & Land Use, Teagasc Environment Research Centre, Johnstown Castle, Co., Wexford, Ireland.
| | - C Müller
- Institute of Plant Ecology (IFZ), Justus-Liebig University Giessen, Germany; School of Biology and Environmental Science and Earth Institute, University College Dublin, Belfield, Dublin, 4, Ireland
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27
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Huang X, Weisener CG, Ni J, He B, Xie D, Li Z. Nitrate assimilation, dissimilatory nitrate reduction to ammonium, and denitrification coexist in Pseudomonas putida Y-9 under aerobic conditions. BIORESOURCE TECHNOLOGY 2020; 312:123597. [PMID: 32506044 DOI: 10.1016/j.biortech.2020.123597] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
The specific nitrate reduction pathway in Pseudomonas putida Y-9 under aerobic conditions was studied. Strain Y-9 removed 82% of the nitrate accompanied by an accumulation of ammonium and a decrease of total nitrogen. Ammonium inhibited nitrate transformation (removal efficiency was 22.65%), illustrating that nitrate assimilation exists in strain Y-9. The detectable ammonium in the supernatant during the nitrate reduction process came from intracellular locations in strain Y-9. The nirBD that encodes nitrite reductase had an important role in strain growth and ammonium production. A 15N isotope experiment demonstrated that strain Y-9 can conduct dissimilatory nitrate reduction to ammonium (DNRA) and nirBD controls this process. This further indicated that the loss of total nitrogen is due to denitrification. All results highlighted that strain Y-9 performs simultaneous nitrate assimilation, DNRA, and denitrification under aerobic conditions, and nirBD controls the assimilation and DNRA process. Thereinto, nitrate assimilation dominates the removal of nitrate.
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Affiliation(s)
- Xuejiao Huang
- Chongqing Key Laboratory of Soil Multiscale Interfacial Process, Southwest University, Chongqing 400716, China
| | - Christopher G Weisener
- Great Lakes Institute of Environmental Research, University of Windsor, Ontario N9B3P4, Canada
| | - Jiupai Ni
- Chongqing Key Laboratory of Soil Multiscale Interfacial Process, Southwest University, Chongqing 400716, China
| | - Binghui He
- Chongqing Key Laboratory of Soil Multiscale Interfacial Process, Southwest University, Chongqing 400716, China
| | - Deti Xie
- Chongqing Key Laboratory of Soil Multiscale Interfacial Process, Southwest University, Chongqing 400716, China
| | - Zhenlun Li
- Chongqing Key Laboratory of Soil Multiscale Interfacial Process, Southwest University, Chongqing 400716, China.
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28
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Wang S, Liu C, Wang X, Yuan D, Zhu G. Dissimilatory nitrate reduction to ammonium (DNRA) in traditional municipal wastewater treatment plants in China: Widespread but low contribution. WATER RESEARCH 2020; 179:115877. [PMID: 32402861 DOI: 10.1016/j.watres.2020.115877] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 04/17/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
Recent reports on the occurrence and contribution of dissimilatory nitrate reduction to ammonium (DNRA) in marine, inland water, and soil systems have greatly improved our understanding of the global nitrogen (N) cycle. This also promoted the investigation of the role and ecological features of DNRA in anthropogenic ecosystems. However, so far, the use of DNRA in municipal wastewater treatment plants (WWTPs), which are one of the most common and largest biotechnologically artificial water ecosystems, has not been investigated. Accordingly, this study focused on the abundance, activity, community structure, and diversity of DNRA bacteria in full-scale WWTPs. DNRA bacteria were detected in all treatment units in six tested municipal WWTPs, even in aerobic zones (dissolved oxygen > 2 mg L-1). Although the relative abundance of DNRA bacteria (0.2-4.0%) was less than that of denitrifying bacteria (0.7-10.1%) among all investigated samples, the abundance of DNRA bacteria still reaches 109 gene copies g-1. However, 15N-isotope tracing indicated that the potential DNRA rates were significantly lower (0.4-2.1 nmol N g-1 h-1) than those of denitrification (9.5-15.7 nmol N g-1 h-1), but higher than anammox rate (0.3-1.3 nmol N g-1 h-1). The DNRA bacterial community structure was primarily affected by temperature gradient despite the treatment process. High-throughput sequencing analysis targeting the DNRA nrfA gene showed that Nitrospira accounted for the largest proportion of nrfA genes among all samples (6.2-36.3%), followed by Brocadia (5.9-22.1%). Network analysis further indicated that Nitrospira played an important role in both the DNRA bacterial community and entire bacterial community in municipal WWTPs. These results suggest that the ecological habitats of DNRA bacteria in anthropogenic ecosystems were far more abundant than previously assumed. However, the contribution to N transformation by the widespread DNRA was not significant in traditional municipal WWTPs.
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Affiliation(s)
- Shanyun Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Chunlei Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Xiaoxia Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Dongdan Yuan
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Guibing Zhu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.
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29
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Zhao Y, Bu C, Yang H, Qiao Z, Ding S, Ni SQ. Survey of dissimilatory nitrate reduction to ammonium microbial community at national wetland of Shanghai, China. CHEMOSPHERE 2020; 250:126195. [PMID: 32092567 DOI: 10.1016/j.chemosphere.2020.126195] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 06/10/2023]
Abstract
Dissimilatory nitrate reduction to ammonia (DNRA) process is an important nitrate reduction pathway in the environment. Numerous studies focused on the DNRA, especially in various natural habitats. However, little is known about the envrionmental parameters driving the DNRA process in anthropogenic ecosystem. Human activities put forward significant influence on nitrogen cycle and bacterial communities of sediment. This study aimed to assess the DNRA potential rates, nrfA gene abundance, DNRA bacterial community's diversity and influencing factors in a national wetland park near the Yangtze River estuary, Shanghai. The results of 15N isotope tracer experiments showed that DNRA potential rates from 0.13 to 0.44 μmol N/kg/h and contribution of nitrate reduction varied from 1.56% to 7.47%. The quantitative real-time PCR results showed that DNRA functional gene nrfA abundances ranged from 9.87E+10 to 1.98E+11 copies/g dry weight. The results of nrfA gene pyrosequencing analysis showed that Lacunisphaera (10.4-13.4%), Sorangium (7.1-10.7%), Aeromonas (4.2-6.8%), Corallococcus (1.8-6.9%), and Geobacter (3.3-6.6%) showed higher relative abundances in their genus levels. Combined with environmental parameters of sediments, redundancy analysis indicated that the nrfA functional gene was positively correlated with moisture content, the concentration of NO2--N and NO3-N; the DNRA rates was positively correlated with sediment organic carbon (SOC), C/NO3- ratio and salinity (ranked by explains %). This study is the first simultaneous determination of nitrate reduction pathways including denitrification, anammox and DNRA rates to assess the role of DNRA in a national wetland park and revealed the community abundance, diversity of DNRA bacteria and its relationship with environmental factors.
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Affiliation(s)
- Yiyi Zhao
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266237, China; State Key Laboratory of Estuarine and Coastal Research, Shanghai, 200241, China; State Key Laboratory of Petroleum Pollution Control, Beijing, 102206, China
| | - Cuina Bu
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266237, China
| | | | - Zhuangming Qiao
- Shandong Meiquan Environmental Protection Technology Co., Ltd., Jinan, China
| | - Shaowu Ding
- Shandong Wanhao Fertilizer Co., Ltd., Jinan, China
| | - Shou-Qing Ni
- Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Qingdao, Shandong, 266237, China; State Key Laboratory of Estuarine and Coastal Research, Shanghai, 200241, China; State Key Laboratory of Petroleum Pollution Control, Beijing, 102206, China.
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30
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Xu H, Lu G, Xue C. Effects of Sulfamethoxazole and 2-Ethylhexyl-4-Methoxycinnamate on the Dissimilatory Nitrate Reduction Processes and N 2O Release in Sediments in the Yarlung Zangbo River. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17061822. [PMID: 32168922 PMCID: PMC7143930 DOI: 10.3390/ijerph17061822] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/08/2020] [Accepted: 03/09/2020] [Indexed: 12/16/2022]
Abstract
The nitrogen pollution of rivers as a global environmental problem has received great attentions in recent years. The occurrence of emerging pollutants in high-altitude rivers will inevitably affect the dissimilatory nitrate reduction processes. In this study, sediment slurry experiments combined with 15N tracer techniques were conducted to investigate the influence of pharmaceutical and personal care products (alone and in combination) on denitrification and the anaerobic ammonium oxidation (anammox) process and the resulting N2O release in the sediments of the Yarlung Zangbo River. The results showed that the denitrification rates were inhibited by sulfamethoxazole (SMX) treatments (1-100 μg L-1) and the anammox rates decreased as the SMX concentrations increased, which may be due to the inhibitory effect of this antibiotic on nitrate reducing microbes. 2-Ethylhexyl-4-methoxycinnamate (EHMC) impacted nitrogen transformation mainly though the inhibition of the anammox processes. SMX and EHMC showed a superposition effect on the denitrification processes. The expression levels of the denitrifying functional genes nirS and nosZ were decreased and N2O release was stimulated due to the presence of SMX and/or EHMC in the sediments. To the best of our knowledge, this study is the first to report the effects of EHMC and its mixtures on the dissimilatory nitrate reduction processes and N2O releases in river sediments. Our results indicated that the widespread occurrence of emerging pollutants in high-altitude rivers may disturb the nitrogen transformation processes and increase the pressure of global warming.
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Affiliation(s)
- Huiping Xu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China;
| | - Guanghua Lu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China;
- Water Conservancy Project & Civil Engineering College, Tibet Agriculture & Animal Husbandry University, Linzhi 860000, China;
- Correspondence: ; Tel.: +86-25-8378-7894
| | - Chenwang Xue
- Water Conservancy Project & Civil Engineering College, Tibet Agriculture & Animal Husbandry University, Linzhi 860000, China;
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Huang Y, Huang J, Ervinia A, Duan S. Tracking riverine nitrate sources under changing land use pattern and hydrologic regime. MARINE POLLUTION BULLETIN 2020; 152:110884. [PMID: 32479274 DOI: 10.1016/j.marpolbul.2020.110884] [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: 10/14/2019] [Revised: 12/27/2019] [Accepted: 01/03/2020] [Indexed: 06/11/2023]
Abstract
It remains challenging to identify nitrate sources in streams due to complications associated with anthropogenic inputs and in-stream biogeochemical processes. We used dual isotopic analysis of nitrate and a Bayesian isotope mixing model to explore the dynamics of nitrate sources and their associated transformations among three types of headwater watershed with different dominant land use types during four seasons in Jiulong River Watershed, a coastal China watershed. Nitrogen sources were the primary determinant of the δ15N-NO3 and seasonal differences in biogeochemical processes exhibited among watersheds. Nitrate was mostly derived from nitrification in spring and summer, whereas atmospheric deposition greatly influenced the isotopic composition in autumn and winter. Chemical fertilizer contributed the largest to the riverine nitrate, accounting for 36.9 ± 12.3%, followed by soil N (27.2 ± 4.4%), atmospheric deposition (23.9 ± 11.8%) and manure & sewage (12.0 ± 5.9%). This study reveals the seasonality of riverine nitrate sources under changing watershed land use patterns.
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Affiliation(s)
- Yaling Huang
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, Xiamen University, Xiamen 361102, China; Institute of Oceanography, Minjiang University, Fuzhou 350108, China
| | - Jinliang Huang
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, Xiamen University, Xiamen 361102, China.
| | - Ayu Ervinia
- Fujian Key Laboratory of Coastal Pollution Prevention and Control, Xiamen University, Xiamen 361102, China
| | - Shuiwang Duan
- Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland, MD 20740, United States
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Li K, Qian J, Wang P, Wang C, Lu B, Tian X, Jin W, He X, Chen H, Zhang Y, Liu Y. Differential responses of encoding-amoA nitrifiers and nir denitrifiers in activated sludge to anatase and rutile TiO 2 nanoparticles: What is active functional guild in rate limiting step of nitrogen cycle? JOURNAL OF HAZARDOUS MATERIALS 2020; 384:121388. [PMID: 31668758 DOI: 10.1016/j.jhazmat.2019.121388] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 09/26/2019] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
The long-terms effects of different crystal-composition TiO2 nanoparticles (NPs) on nitrogen-cycle-related functional guilds in activated sludge remain unclear, especially under natural light irradiation. Accordingly, activated sludge was exposed to anatase TiO2-NPs (TiO2-A) and rutile TiO2-NPs (TiO2-R) for up to 45 days. With markedly (p < 0.05) reducing nitrification-/denitrification-enzymatic-activities and abundances of ammonia-oxidizing-microorganisms (AOMs) and nitrite-reducing-bacteria (NRB), TiO2-NPs triggered bacteria and archaea UPGMA clustering and a deep modification of N-cycling functional diversity guided by crystal structure. in situ13C-DNA-SIP confirmed ammonia-oxidizing-bacteria (AOB) (Nitrosomonas and Nitrosospira) in original sludge as main active AOMs with 75.4 times more abundance than ammonia-oxidizing-archaea (AOA), while AOA within Nitrosopumilus and Nitrososphaera genera were the main active AOMs and tended to aggregate inside sludge after 10-mg/L TiO2-NPs exposure. Encoding-nirK NRB were more sensitive, while encoding-nirS Zoogloea with a total share of 4.97% to 14.93%, etc. were the main active NRB. AOB was more sensitive to TiO2-A, while TiO2-R showed the stronger toxicity to AOA and NRB resulting from differences in water environmental behaviors and crystal characteristics of two TiO2-NPs. This work expands understanding of the ecological risks of titanium-dioxide-crystal-NPs in aquatic environment and may help devise better methods to alleviate environmental stress caused by NPs at wastewater treatment plants.
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Affiliation(s)
- Kun Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Jin Qian
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
| | - Chao Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Bianhe Lu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Xin Tian
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Wen Jin
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Xixian He
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Hao Chen
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Yuhang Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
| | - Yin Liu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China
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Bi Z, Zhang W, Song G, Huang Y. Iron-dependent nitrate reduction by anammox consortia in continuous-flow reactors: A novel prospective scheme for autotrophic nitrogen removal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 692:582-588. [PMID: 31539965 DOI: 10.1016/j.scitotenv.2019.07.078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/19/2019] [Accepted: 07/05/2019] [Indexed: 06/10/2023]
Abstract
Anammox bacteria are chemolithotrophic organisms growing on the conversion of ammonium and nitrite with bicarbonate as the sole carbon source. Meanwhile, anammox bacteria display a metabolic versatility to sustain their metabolism. However, there is less attention on the Fe0/Fe2+-dependent autotrophic denitrification by anammox consortia. In this study, the autotrophic nitrate reduction using different valence of iron (Fe0, Fe2+ and Fe0+ Fe2+, respectively) as electron donors by anammox consortia were firstly explored in continuous feeding mode. Results revealed anammox consortia showed high adaptability to the niche wherein containing nitrate and iron. They could generate nitrite and ammonium from iron-dependent nitrate reduction, and hence support their central metabolism. During 60-days operation, the maximum nitrate and total nitrogen removal efficiency reached 88.43% and 80.77%, respectively, with coexistence of Fe0 and Fe2+. The expression of key functional genes involved in nitrate reduction (including narG, napA and nrfA) in 16S rRNA level revealed the coupling of dissimilatory nitrate reduction to nitrite, dissimilatory nitrite reduction to ammonia (DNRA), and anammox processes possibly play pivotal role in nitrogen loss under Fe0/Fe2+ condition. Meanwhile, abiotic reduction by Fe0/Fe2+ also contributed nitrate reduction to provide nitrite and ammonium for anammox consortia. Activities of two vital enzymes hydrazine dehydrogenase (HDH) and nitrate oxidoreduetase (NAR) also inferred higher microbial activities with co-existence of Fe0 and Fe2+. The present study confirms and further extends the versatile metabolisms of Anammox consortia, also it can help to circumvent the accumulation of nitrate produced by anammox process itself and increase the quality of discharge.
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Affiliation(s)
- Zhen Bi
- National and Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215002, China; School of Environment Science and Engineering, Suzhou University of Science and Technology, Suzhou 215002, China
| | - Wenjing Zhang
- School of Environment Science and Engineering, Suzhou University of Science and Technology, Suzhou 215002, China
| | - Ge Song
- School of Environment Science and Engineering, Suzhou University of Science and Technology, Suzhou 215002, China
| | - Yong Huang
- National and Local Joint Engineering Laboratory for Municipal Sewage Resource Utilization Technology, Suzhou University of Science and Technology, Suzhou 215002, China; School of Environment Science and Engineering, Suzhou University of Science and Technology, Suzhou 215002, China.
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Xin J, Liu Y, Chen F, Duan Y, Wei G, Zheng X, Li M. The missing nitrogen pieces: A critical review on the distribution, transformation, and budget of nitrogen in the vadose zone-groundwater system. WATER RESEARCH 2019; 165:114977. [PMID: 31446294 DOI: 10.1016/j.watres.2019.114977] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 07/29/2019] [Accepted: 08/12/2019] [Indexed: 06/10/2023]
Abstract
Intensive agriculture and urbanization have led to the excessive and repeated input of nitrogen (N) into soil and further increased the amount of nitrate (NO3-) leaching into groundwater, which has become an environmental problem of widespread concern. This review critically examines both the recent advances and remaining knowledge gaps with respect to the N cycle in the vadose zone-groundwater system. The key aspects regarding the N distribution, transformation, and budget in this system are summarized. Three major missing N pieces (N in dissolved organic form, N in the deep vadose zone, and N in the nonagricultural system), which are crucial for closing the N cycle yet has been previously assumed to be insignificant, are put forward and discussed. More work is anticipated to obtain accurate information on the chemical composition, transformation mechanism, and leaching flux of these missing N pieces in the vadose zone-groundwater system. These are essential to support the assessment of global N stocks and management of N contamination risks.
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Affiliation(s)
- Jia Xin
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
| | - Yang Liu
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Fei Chen
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China
| | - Yijun Duan
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China
| | - Guanli Wei
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Xilai Zheng
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education, Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering, College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Miao Li
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing, 100084, China
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Huang J, Cao C, Liu J, Yan C, Xiao J. The response of nitrogen removal and related bacteria within constructed wetlands after long-term treating wastewater containing environmental concentrations of silver nanoparticles. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 667:522-531. [PMID: 30833250 DOI: 10.1016/j.scitotenv.2019.02.396] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/21/2019] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
The wide application of consumer products containing silver nanoparticles (AgNPs) inevitably results in their release into sewer systems and wastewater treatment plants, where they would encounter (and cause potential negative impacts) constructed wetlands (CWs), a complex biological system containing plants, substrate and microorganisms. Herein, the long-term effects of environmental AgNPs concentrations on nitrogen removal, key enzymatic activities and nitrogen-related microbes in constructed wetlands (CWs) were investigated. The short-term exposure (40 d) to AgNPs significantly inhibited TN and NH4+-N removal, and the inhibition degree had a positive relationship with AgNPs levels. After about 450 d exposure, 200 μg/L AgNPs could slightly increase average TN removal efficiency, while presence of 50 μg/L AgNPs showed no difference, compared to control. The NH4+-N removal in all CWs had no difference. The present study indicated that short-term AgNPs loading evidently reduced nitrogen removal, whereas long-term exposure to AgNPs showed no adverse impacts on NH4+-N removal and slightly stimulated TN removal, which was related to the increase of corresponding enzymatic activities. After exposing AgNPs for 450 d, the abundance of relative functional genes and the composition of key community structure were determined by qPCR and high-throughput sequencing, respectively. The results showed that the abundance of amoA and nxrA dramatically higher than control, whereas the abundance of nirK, nirS, nosZ and anammox 16S rRNA was slightly higher than control, but had no statistical difference, which accorded with the TN removal performance. The microbial community analysis showed that different AgNPs concentrations could affect the microbial diversity and structure. The changes of the relative abundance of nitrogen-related genera were associated with the impacts of AgNPs on the nitrogen removal performance. Overall, the AgNPs loading had impacts on the key enzymatic activities, the abundance of nitrogen-related genes and microbial community, thus finally affected the treatment performance of CWs.
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Affiliation(s)
- Juan Huang
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 210096, China.
| | - Chong Cao
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 210096, China
| | - Jialiang Liu
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 210096, China
| | - Chunni Yan
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 210096, China
| | - Jun Xiao
- Department of Municipal Engineering, School of Civil Engineering, Southeast University, Nanjing 210096, China
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36
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Yoon S, Song B, Phillips RL, Chang J, Song MJ. Ecological and physiological implications of nitrogen oxide reduction pathways on greenhouse gas emissions in agroecosystems. FEMS Microbiol Ecol 2019; 95:5488431. [DOI: 10.1093/femsec/fiz066] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Accepted: 05/10/2019] [Indexed: 11/12/2022] Open
Abstract
ABSTRACT
Microbial reductive pathways of nitrogen (N) oxides are highly relevant to net emissions of greenhouse gases (GHG) from agroecosystems. Several biotic and abiotic N-oxide reductive pathways influence the N budget and net GHG production in soil. This review summarizes the recent findings of N-oxide reduction pathways and their implications to GHG emissions in agroecosystems and proposes several mitigation strategies. Denitrification is the primary N-oxide reductive pathway that results in direct N2O emissions and fixed N losses, which add to the net carbon footprint. We highlight how dissimilatory nitrate reduction to ammonium (DNRA), an alternative N-oxide reduction pathway, may be used to reduce N2O production and N losses via denitrification. Implications of nosZ abundance and diversity and expressed N2O reductase activity to soil N2O emissions are reviewed with focus on the role of the N2O-reducers as an important N2O sink. Non-prokaryotic N2O sources, e.g. fungal denitrification, codenitrification and chemodenitrification, are also summarized to emphasize their potential significance as modulators of soil N2O emissions. Through the extensive review of these recent scientific advancements, this study posits opportunities for GHG mitigation through manipulation of microbial N-oxide reductive pathways in soil.
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Affiliation(s)
- Sukhwan Yoon
- Department of Civil and Environmental Engineering, KAIST, 291 Daehakro, Yuseonggu, Daejeon 34141, South Korea
| | - Bongkeun Song
- Department of Biological Sciences, Virginia Institute of Marine Sciences, College of William and Mary, 1375 Greate Rd, Gloucester Point, VA 23062, USA
| | - Rebecca L Phillips
- Ecological Insights Corporation, 130 69th Street SE, Hazelton, ND 58544, USA
| | - Jin Chang
- Department of Civil and Environmental Engineering, KAIST, 291 Daehakro, Yuseonggu, Daejeon 34141, South Korea
| | - Min Joon Song
- Department of Civil and Environmental Engineering, KAIST, 291 Daehakro, Yuseonggu, Daejeon 34141, South Korea
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Cannon J, Sanford RA, Connor L, Yang WH, Chee-Sanford J. Optimization of PCR primers to detect phylogenetically diverse nrfA genes associated with nitrite ammonification. J Microbiol Methods 2019; 160:49-59. [PMID: 30905502 DOI: 10.1016/j.mimet.2019.03.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 03/20/2019] [Accepted: 03/20/2019] [Indexed: 10/27/2022]
Abstract
Dissimilatory nitrate reduction to ammonium (DNRA) is now known to be a more prevalent process in terrestrial ecosystems than previously thought. The key enzyme, a pentaheme cytochrome c nitrite reductase NrfA associated with respiratory nitrite ammonification, is encoded by the nrfA gene in a broad phylogeny of bacteria. The lack of reliable and comprehensive molecular tools to detect diverse nrfA from environmental samples has hampered efforts to meaningfully characterize the genetic potential for DNRA in environmental systems. In this study, modifications were made to optimize the amplification efficiency of previously-designed PCR primers, targeting the diagnostic region of NrfA between the conserved third- and fourth heme binding domains, and to increase coverage to include detection of environmentally relevant Geobacteraceae-like nrfA. Using an alignment of the primers to >270 bacterial nrfA genes affiliated with 18 distinct clades, modifications to the primer sequences improved coverage, minimized amplification artifacts, and yielded the predicted product sizes from reference-, soil-, and groundwater DNA. Illumina sequencing of amplicons showed the successful recovery of nrfA gene fragments from environmental DNA based on alignments of the translated sequences. The new primers developed in this study are more efficient in PCR reactions, although gene targets with high GC content affect efficiency. Furthermore, the primers have a broader spectrum of detection and were validated rigorously for use in detecting nrfA from natural environments. These are suitable for conventional PCR, qPCR, and use in PCR access array technologies that allow multiplex gene amplification for downstream high throughput sequencing platforms.
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Affiliation(s)
- Jordan Cannon
- Dept. of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Robert A Sanford
- Dept. of Geology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | | | - Wendy H Yang
- Dept. of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Dept. of Geology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
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Gold AC, Thompson SP, Piehler MF. Nitrogen cycling processes within stormwater control measures: A review and call for research. WATER RESEARCH 2019; 149:578-587. [PMID: 30513447 DOI: 10.1016/j.watres.2018.10.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/11/2018] [Accepted: 10/12/2018] [Indexed: 06/09/2023]
Abstract
Stormwater control measures (SCMs) have the potential to mitigate negative effects of watershed development on hydrology and water quality. Stormwater regulations and scientific literature have assumed that SCMs are important sites for denitrification, the permanent removal of nitrogen, but this assumption has been informed mainly by short-term loading studies and measurements of potential rates of nitrogen cycling. Recent research concluded that SCM nitrogen removal can be dominated by plant and soil assimilation rather than by denitrification, and rates of nitrogen fixation can exceed rates of denitrification in SCM sediments, resulting in a net addition of nitrogen. Nitrogen cycling measurements from other human-impacted aquatic habitats have presented similar results, additionally suggesting that dissimilatory nitrate reduction to ammonium (DNRA) and algal uptake could be important processes for recycling nitrogen in SCMs. Future research should directly measure a suite of nitrogen cycling processes in SCMs and reveal controlling mechanisms of individual rate processes. There is ample opportunity for research on SCM nitrogen cycling, including investigations of seasonal variation, differences between climatic regions, and trade-offs between nitrogen removal and phosphorus removal. Understanding nitrogen dynamics within SCMs will inform more efficient SCM design and management that promotes denitrification to help mitigate negative effects of urban stormwater on downstream ecosystems.
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Affiliation(s)
- Adam C Gold
- UNC Institute of Marine Sciences, 3431 Arendell St., Morehead City, NC, 28557, United States; UNC Environment, Ecology, and Energy Program, 3202 Murray/Venable Hall, CB#3275, Chapel Hill, NC, 27599, United States.
| | - Suzanne P Thompson
- UNC Institute of Marine Sciences, 3431 Arendell St., Morehead City, NC, 28557, United States
| | - Michael F Piehler
- UNC Institute of Marine Sciences, 3431 Arendell St., Morehead City, NC, 28557, United States; UNC Environment, Ecology, and Energy Program, 3202 Murray/Venable Hall, CB#3275, Chapel Hill, NC, 27599, United States; UNC Institute for the Environment, 100 Europa Dr., Suite 490, Chapel Hill, NC, 27517, United States
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Li S, Luo Z, Ji G. Seasonal function succession and biogeographic zonation of assimilatory and dissimilatory nitrate-reducing bacterioplankton. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 637-638:1518-1525. [PMID: 29801245 DOI: 10.1016/j.scitotenv.2018.05.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/01/2018] [Accepted: 05/02/2018] [Indexed: 06/08/2023]
Abstract
The dominance of different nitrate-reducing pathways determines nitrogen cycling patterns. Denitrification (DNF) has been widely studied, but assimilatory nitrate reduction (ANR) and dissimilatory nitrate reduction to ammonium (DNRA) have received much less attention. Their ecological patterns and responsible microbes are poorly understood. Here, we studied the structure and function succession of the three functional groups in the middle route of the South-to-North Water Diversion Project, which is a 1230 km canal spanning 8 degrees of latitude. The results reflected a nitrogen-removing pattern dominated by DNF in the summer and a nitrogen-retaining pattern dominated by ANR and DNRA in the winter. Stenotrophomonas, a typical denitrifier, was the keystone species in the summer and contributed to N2O production. Clostridium, a genus able to conduct ANR and DNRA, was the keystone species in the winter. Notably, a significant zonation pattern was discovered. According to the community structure, the system could be separated into two biogeographic zones, and the Yellow River (about latitude 35°N) is an important cut-off line. This bacterial biogeography followed different water characteristics and ecological processes. ANR was found to be an important process and seasonally transformed its habitat from the northern zone to the southern zone. DNRA bacteria were acclimated to the northern zone and favored at this region in both seasons. The generation of N2O, a strong greenhouse gas, also exhibited this zonation pattern. This is the first study to consider assimilatory and dissimilatory nitrate reducers together at a molecular level, and provides new insights into the underlying patterns of a nitrate-reducing bacterioplankton community.
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Affiliation(s)
- Shengjie Li
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing 100871, China
| | - Zhongxin Luo
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing 100871, China
| | - Guodong Ji
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, Department of Environmental Engineering, Peking University, Beijing 100871, China.
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40
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Meghdadi A, Javar N. Evaluation of nitrate sources and the percent contribution of bacterial denitrification in hyporheic zone using isotope fractionation technique and multi-linear regression analysis. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 222:54-65. [PMID: 29802986 DOI: 10.1016/j.jenvman.2018.05.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/07/2018] [Accepted: 05/08/2018] [Indexed: 06/08/2023]
Abstract
Denitrification has documented as a promising pathway to permanently remove nitrate from a system. Numerous studies have used the isotope fractionation technique (IFT) to evaluate the denitrification rate in the constructed wetlands (CWs), but the potential of IFT method to quantify the denitrification rate in hyporheic zone (saturated sediments beneath a stream) is still challenging. Thus, more studies are required to investigate that if measurements of the natural abundance of δ15N-NO3- and δ18O-NO3- (IFT) can be employed to calculate the fate of nitrate in hyporheic zone. Therefore, in this study, the possibility of the IFT to quantify the hyporheic-denitrification rate was investigated. Then, the results were verified by the combined application of the pre-established net Sediment N2 flux and multi-linear regression analysis (p < 0.01). Finally, the groundwater bacterial groups (Fecal coliform (FC) and Escherichia coli (EC)), and the mass balance isotope mixing model were used to investigate the dominant sources of hyporheic-nitrate. The IFT reveals that denitrification contributes 74.1% and 29.1% of the hyporheic-nitrate removal during dry and wet seasons, respectively. The multi-linear regression analysis, considering at 99% confidence interval (R2 = 92.1%; n = 44; p < 0.01), slightly overestimates the rate and the percent contribution of denitrification in the dry season (475.15 ± 101.18 μmol/m2d; 80.7%) and underestimates it during the wet season (205.072 ± 35.39 μmol/m2d; 24.01%). The analysis of EC and FC demonstrates that manure (41.9 ± 4.2%) and sewage (54.1 ± 8.9%) are the dominant contributors of the hyporheic-nitrate load. In addition, the results achieved by the analysis of the fecal bacterial indicators (EC and FC) were confirmed by NO3-/Cl- vs Cl- diagram. This study provides an alternative-initiative framework to accurately quantify the spatio-seasonal variations in the hyporheic-nitrate sources and hyporheic-denitrification rate that enables decision-makers to apply appropriate and targeted strategies to regulate nitrate load in river-aquifer systems.
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Affiliation(s)
- Aminreza Meghdadi
- Science and Engineering Faculty, School of Earth Environmental and Biological Science, Queensland University of Technology, GPO Box 2434, Brisbane, 4001, QLD, Australia.
| | - Narmin Javar
- School of Environmental and Biological Science (SEBS), Islamic Azad University, Zanjan Branch, Zanjan, Iran.
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Meghdadi A. Characterizing the capacity of hyporheic sediments to attenuate groundwater nitrate loads by adsorption. WATER RESEARCH 2018; 140:364-376. [PMID: 29751318 DOI: 10.1016/j.watres.2018.04.063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 06/08/2023]
Abstract
Nitrate has been recognized as a global threat to environmental health. In this regard, the hyporheic zone (saturated media beneath and adjacent to the stream bed) plays a crucial role in attenuating groundwater nitrate, prior to discharge into surface water. While different nitrate removal pathways have been investigated over recent decades, the adsorption capacity of hyporheic sediments under natural conditions has not yet been identified. In this study, the natural attenuation capacity of the hyporheic-sediments of the Ghezel-Ozan River, located in the north-west of Iran, was determined. The sampled sediments (from 1 m below the stream bed) were characterized via XRD, FT-IR, BET, SEM, BJH, and Zeta potential. Nitrate adsorption was evaluated using a batch experiment with hyporheic pore-water from each study site. The study was performed in the hyporheic sediments of two morphologically different zones, including Z1 located in the parafluvial zone having the clay sediment texture (57.8% clay) with smectite/Illite mixed layer clay type and Z2 located in the river confluence area containing silty clay sediment texture (47.6% clay) with smectite/kaolinite mixed layer clay type. Data obtained from the batch experiment were subjected to pseudo-first order, pseudo-second order, intra-particle diffusion, and Elovich mass transfer kinetic models to characterize the nitrate adsorption mechanism. Furthermore, to replicate nitrate removal efficiencies of the hyporheic sediments under natural conditions, the sampled hyporheic pore-waters were applied as initial solutions to run the batch experiment. The results of the artificial nitrate solution correlated well with pseudo-second order (R2>95%; in both Z1 and Z2) and maximum removal efficiencies of 85.3% and 71.2% (adsorbent dosage 90 g/L, pH = 5.5, initial adsorbate concentration of 90 mg/L) were achieved in Z1 and Z2, respectively. The results of the nitrate adsorption analysis revealed that the nitrate removal efficiencies varied from 17.24 ± 1.86% in Z1 during the wet season to 28.13 ± 0.89% in Z2 during the dry season. The results obtained by this study yielded strong evidence of the potential of hyporheic sediments to remove nitrate from an aqueous environment with great efficiency.
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Affiliation(s)
- Aminreza Meghdadi
- Science and Engineering Faculty, School of Earth Environmental and Biological Science, Queensland University of Technology, 4000, Brisbane, QLD, Australia.
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Wang S, Wang W, Liu L, Zhuang L, Zhao S, Su Y, Li Y, Wang M, Wang C, Xu L, Zhu G. Microbial Nitrogen Cycle Hotspots in the Plant-Bed/Ditch System of a Constructed Wetland with N 2O Mitigation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:6226-6236. [PMID: 29750509 DOI: 10.1021/acs.est.7b04925] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Artificial microbial nitrogen (N) cycle hotspots in the plant-bed/ditch system were developed and investigated based on intact core and slurry assays measurement using isotopic tracing technology, quantitative PCR and high-throughput sequencing. By increasing hydraulic retention time and periodically fluctuating water level in heterogeneous riparian zones, hotspots of anammox, nitrification, denitrification, ammonium (NH4+) oxidation, nitrite (NO2-) oxidation, nitrate (NO3-) reduction and DNRA were all stimulated at the interface sediments, with the abundance and activity being about 1-3 orders of magnitude higher than those in nonhotspots. Isotopic pairing experiments revealed that in microbial hotspots, nitrite sources were higher than the sinks, and both NH4+ oxidation (55.8%) and NO3- reduction (44.2%) provided nitrite for anammox, which accounted for 43.0% of N-loss and 44.4% of NH4+ removal in riparian zones but did not involve nitrous oxide (N2O) emission risks. High-throughput analysis identified that bacterial quorum sensing mediated this anammox hotspot with B.fulgida dominating the anammox community, but it was B. anammoxidans and Jettenia sp. that contributed more to anammox activity. In the nonhotspot zones, the NO2- source (NO3- reduction dominated) was lower than the sink, limiting the effects on anammox. The in situ N2O flux measurement showed that the microbial hotspot had a 27.1% reduced N2O emission flux compared with the nonhotspot zones.
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Affiliation(s)
- Shanyun Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
| | - Weidong Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
| | - Lu Liu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
| | - Linjie Zhuang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
| | - Siyan Zhao
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Yu Su
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Yixiao Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
| | - Mengzi Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
| | - Cheng Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Liya Xu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
| | - Guibing Zhu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
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Li YH, Li HB, Xu XY, Wang SQ, Pan J. Does carbon-nitrogen ratio affect nitrous oxide emission and spatial distribution in subsurface wastewater infiltration system? BIORESOURCE TECHNOLOGY 2018; 250:846-852. [PMID: 30001592 DOI: 10.1016/j.biortech.2017.12.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 06/08/2023]
Abstract
In order to evaluate the effects of carbon-nitrogen ratio (CNR) on nitrous oxide (N2O) emission and quantify N2O spatial distribution in subsurface wastewater infiltration system (SWIS), layered sampling method was introduced. Results showed that low N2O emission rate (1.43 mg/m2·h) and conversion rate (0.1% accounting for influent TN) were obtained when CNR increased up to as high as 10. The highest N2O emission (3.14 mg/m2·h) was observed at CNR of 6. Instead, independent of CNR variations, 0-75 cm was the main contributor for N2O emission. The results indicated that layered sampling method is necessary in revealing N2O spatial distribution in soil layers. Carbon source availability and nitrogen load and their ratio (i.e. CNR) determined N2O emission rate. CNR of medium level leads to an increase in N2O emission rate.
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Affiliation(s)
- Ying-Hua Li
- School of Resources and Civil Engineering, Northeastern University, Shenyang, China
| | - Hai-Bo Li
- School of Resources and Civil Engineering, Northeastern University, Shenyang, China.
| | - Xin-Yang Xu
- School of Resources and Civil Engineering, Northeastern University, Shenyang, China
| | - Si-Qi Wang
- School of Resources and Civil Engineering, Northeastern University, Shenyang, China
| | - Jing Pan
- College of Chemistry and Life Science, Shenyang Normal University, Shenyang, China
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张 新. Dominant Factors of Dissimilatory Nitrate Reduction to Ammonia (DNRA) in Activated Sludge System: A Comment. ACTA ACUST UNITED AC 2018. [DOI: 10.12677/aep.2018.82012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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