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Fan L, Cheng J, Xie Y, Xu L, Buttler A, Wu Y, Fan H, Wu Y. Spatio-temporal patterns and drivers of CH 4 and CO 2 fluxes from rivers and lakes in highly urbanized areas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 918:170689. [PMID: 38320709 DOI: 10.1016/j.scitotenv.2024.170689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 01/25/2024] [Accepted: 02/02/2024] [Indexed: 02/13/2024]
Abstract
Gaseous carbon exchange at the water-air interface of rivers and lakes is an essential process for regional and global carbon cycle assessments. Many studies have shown that rivers surrounding urban landscapes can be hotspots for greenhouse gas (GHG) emissions. Here we investigated the variability of diffusive GHG (methane [CH4] and carbon dioxide [CO2]) emissions from rivers in different landscapes (i.e., urban, agricultural and mixed) and from lakes in Suzhou, a highly urbanized region in eastern China. GHG emissions in the Suzhou metropolitan water network followed a typical seasonal pattern, with the highest fluxes in summer, and were primarily influenced by temperature and dissolved oxygen concentration. Surprisingly, lakes were emission hotspots, with mean CH4 and CO2 fluxes of 2.80 and 128.89 mg m-2 h-1, respectively, translating to a total CO2-equivalent flux of 0.21 g CO2-eq m-2 d-1. The global warming potential of urban and mixed rivers (0.19 g CO2-eq m-2 d-1) was comparable to that for lakes, but about twice the value for agricultural rivers (0.10 g CO2-eq m-2 d-1). Factors related to the high GHG emissions in lakes included hypoxic water conditions and an adequate nutrient supply. Riverine CH4 emissions were primarily associated with the concentrations of total dissolved solids (TDS), ammonia‑nitrogen and chlorophyll a. CO2 emissions in rivers were mainly closely related to TDS, with suitable conditions allowing rapid organic matter decomposition. Compared with other types of rivers, urban rivers had more available organic matter and therefore higher CO2 emissions. Overall, this study emphasizes the need for a deeper understanding of the impact of GHG emissions from different water types on global warming in rapidly urbanizing regions. Flexible management measures are urgently needed to mitigate CO2 and CH4 emissions more effectively in the context of the shrinking gap between urban and rural areas with growing socio-economic development.
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Affiliation(s)
- Longfeng Fan
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Junxiang Cheng
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; Jiangxi Research Academy of Ecological Civilization, Nanchang 330036, PR China.
| | - Yangcun Xie
- Chinese Academy of Environmental Planning, Beijing 100043, PR China.
| | - Ligang Xu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; University of Chinese Academy of Sciences, Nanjing, Nanjing 211135, PR China
| | - Alexandre Buttler
- School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Federal of Lausanne (EPFL), Station 2, CH-1015 Lausanne, Switzerland; Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Site Lausanne, Station 2, CH-1015 Lausanne, Switzerland
| | - Yuexia Wu
- School of Business Administration, Nanjing University of Finance & Economics, Nanjing 210023, PR China
| | - Hongxiang Fan
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Yakun Wu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, PR China; School of Energy and Environment, Anhui University of Technology, Ma'anshan 243002, PR China
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Sierra A, Correia C, Ortega T, Forja J, Rodrigues M, Cravo A. Dynamics of CO 2, CH 4, and N 2O in Ria Formosa coastal lagoon (southwestern Iberia) and export to the Gulf of Cadiz. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167094. [PMID: 37734615 DOI: 10.1016/j.scitotenv.2023.167094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 08/16/2023] [Accepted: 09/13/2023] [Indexed: 09/23/2023]
Abstract
A first characterization of greenhouse gases had been carried out to study their role and impact in a productive transitional coastal system of the southern Portugal - Ria Formosa lagoon. To this purpose, the partial pressure of CO2 (pCO2) and the concentration of dissolved CH4 and N2O have been measured. Two surveys were carried out during 2020, at low tide under typical conditions of Spring (March) and end of Summer (October). The samplings sites were distributed along the costal lagoon covering: i) inner areas with strong human impact (influence of different flows of treated wastewater discharges); and ii) main channels in connection with the main inlets to study the exchanges with the ocean. In general, the highest values of the three greenhouse gases were found at the inner studied areas, especially affected by the disposal of treated effluents from wastewater treatment plans, in October. The mean water - atmosphere fluxes of the CO2, CH4 and N2O are positive, showing that the study area acts as a source of these gases to the atmosphere. On the other hand, it was calculated a rough estimation of the three gases globally exported from Ria Formosa to the ocean, through the main six inlets to evaluate the magnitude of the supply of these gases from Ria Formosa to the adjacent ocean. The mean CO2, CH4 and N2O horizontal water fluxes exported from all the inlets of Ria Formosa to the Gulf of Cadiz for both seasons, during low water, are 8.7 ± 3.9 mmol m-2 s-1, 8.0 ± 3.5 μmol m-2 s-1 and 3.2 ± 1.5 μmol m-2 s-1, which corresponds to a mass transport through the inlets section of 0.7 ± 0.7 kg s-1, 0.2 ± 0.2 g s-1 and 0.2 ± 0.3 g s-1 respectively. From these estimates, as expected, the higher mass transport was found at the larger and deeper inlets (Faro-Olhão and Armona).
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Affiliation(s)
- A Sierra
- Dpto. Química-Física, INMAR, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Campus Universitario Río San Pedro, 11510 Puerto Real, Cádiz, Andalucía, Spain.
| | - C Correia
- FCT, CIMA, Centre of Marine and Environmental Research\ARNET - Infrastructure Network in Aquatic Research, University of Algarve, Campus de Gambelas, 8000-139 Faro, Portugal.
| | - T Ortega
- Dpto. Química-Física, INMAR, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Campus Universitario Río San Pedro, 11510 Puerto Real, Cádiz, Andalucía, Spain.
| | - J Forja
- Dpto. Química-Física, INMAR, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Campus Universitario Río San Pedro, 11510 Puerto Real, Cádiz, Andalucía, Spain.
| | - M Rodrigues
- Laboratório Nacional de Engenharia Civil, Avenida do Brasil, 101, 1700-066 Lisboa, Portugal.
| | - A Cravo
- FCT, CIMA, Centre of Marine and Environmental Research\ARNET - Infrastructure Network in Aquatic Research, University of Algarve, Campus de Gambelas, 8000-139 Faro, Portugal.
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Li X, He Y, Wang X, Chen H, Liu T, Que Y, Yuan X, Wu S, Zhou T. Watershed urbanization dominated the spatiotemporal pattern of riverine methane emissions: Evidence from montanic streams that drain different landscapes in Southwest China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 873:162343. [PMID: 36813197 DOI: 10.1016/j.scitotenv.2023.162343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
Methane (CH4) emissions from streams are an important component of the global carbon budget of freshwater ecosystems, but these emissions are highly variable and uncertain at the temporal and spatial scales associated with watershed urbanization. In this study, we conducted investigations of dissolved CH4 concentrations and fluxes and related environmental parameters at high spatiotemporal resolution in three montanic streams that drain different landscapes in Southwest China. We found that the average CH4 concentrations and fluxes in the highly urbanized stream (2049 ± 2164 nmol L-1 and 11.95 ± 11.75 mmol·m-2·d-1) were much higher than those in the suburban stream (1021 ± 1183 nmol L-1 and 3.29 ± 3.66 mmol·m-2·d-1) and were approximately 12.3 and 27.8 times those in the rural stream, respectively. It provides powerful evidence that watershed urbanization strongly enhances riverine CH4 emission potential. Temporal patterns of CH4 concentrations and fluxes and their controls were not consistent among the three streams. Seasonal CH4 concentrations in the urbanized streams had negative exponential relationships with monthly precipitation and demonstrated greater sensitivity to rainfall dilution than to the temperature priming effect. Additionally, the CH4 concentrations in the urban and semiurban streams showed strong, but opposite, longitudinal patterns, which were closely related to urban distribution patterns and the HAILS (human activity intensity of the land surface) within the watersheds. High carbon and nitrogen loads from sewage discharge in urban areas and the spatial arrangement of the sewage drainage contributed to the different spatial patterns of the CH4 emissions in different urbanized streams. Moreover, CH4 concentrations in the rural stream were mainly controlled by pH and inorganic nitrogen (NH4+ and NO3-), while urban and semiurban streams were dominated by total organic carbon and nitrogen. We highlighted that rapid urban expansion in montanic small catchments will substantially enhance riverine CH4 concentrations and fluxes and dominate their spatiotemporal pattern and regulatory mechanisms. Future work should consider the spatiotemporal patterns of such urban-disturbed riverine CH4 emissions and focus on the relationship between urban activities with aquatic carbon emissions.
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Affiliation(s)
- Xianxiang Li
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing 401331, China; Chongqing Observation and Research Station of Earth Surface Ecological Processes in Three Gorges Reservoir Area, Chongqing 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing 400047, China
| | - Yixin He
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization, Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan 624400, China
| | - Xiaofeng Wang
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing 401331, China; Chongqing Observation and Research Station of Earth Surface Ecological Processes in Three Gorges Reservoir Area, Chongqing 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing 400047, China.
| | - Huai Chen
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization, Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan 624400, China
| | - Tingting Liu
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing 401331, China; East China Normal University, Shanghai 200241, China
| | - Yizi Que
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing 401331, China; Chongqing Observation and Research Station of Earth Surface Ecological Processes in Three Gorges Reservoir Area, Chongqing 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing 400047, China
| | - Xingzhong Yuan
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, China
| | - Shengnan Wu
- Chongqing Observation and Research Station of Earth Surface Ecological Processes in Three Gorges Reservoir Area, Chongqing 405400, China; East China Normal University, Shanghai 200241, China
| | - Ting Zhou
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing 401331, China; Chongqing Observation and Research Station of Earth Surface Ecological Processes in Three Gorges Reservoir Area, Chongqing 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing 400047, China
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Khan MA, Kumar S, Roy R, Prakash S, Lotliker AA, Baliarsingh SK. Effects of tidal cycle on greenhouse gases emissions from a tropical estuary. MARINE POLLUTION BULLETIN 2023; 189:114733. [PMID: 36827771 DOI: 10.1016/j.marpolbul.2023.114733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 01/27/2023] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
The potential effects of tidal and diel cycles on fluxes and concentrations of carbon dioxide (pCO2), methane (CH4), and nitrous oxide (N2O) along with associated biogeochemical processes remain poorly understood in tropical estuaries. The present study, based on six-hourly sampling for nine consecutive days at three locations along the salinity gradient in the Mahanadi estuary of India, revealed that the tidal forcing affected pCO2 and CH4 in the mixing zone with elevated concentrations during low tide with maximum concentrations up to 21,606 μatm and 285 μM, respectively. pCO2 increased with decrease in tidal height within low and high tide duration as well, possibly due to higher relative contribution of freshwater with high CO2. N2O, on the other hand, showed no significant variability with tidal cycle or water level fluctuation during high and low tide. Barring the offshore region, the study area was source of greenhouse gases to the atmosphere.
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Affiliation(s)
- Mohammad Atif Khan
- Geosciences Division, Physical Research Laboratory, Ahmedabad, India; Department of Earth Sciences, Gujarat University, Ahmedabad, India
| | - Sanjeev Kumar
- Geosciences Division, Physical Research Laboratory, Ahmedabad, India.
| | - Rajdeep Roy
- Regional Remote Sensing Centre - East, National Remote Sensing Centre, Indian Space Research Organization, Kolkata, India
| | - Satya Prakash
- Indian National Centre for Ocean Information Services, Ministry of Earth Sciences, Government of India, Hyderabad, India
| | - Aneesh A Lotliker
- Indian National Centre for Ocean Information Services, Ministry of Earth Sciences, Government of India, Hyderabad, India
| | - Sanjiba Kumar Baliarsingh
- Indian National Centre for Ocean Information Services, Ministry of Earth Sciences, Government of India, Hyderabad, India
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Patel L, Singh R, Thottathil SD. Land use drivers of riverine methane dynamics in a tropical river basin, India. WATER RESEARCH 2023; 228:119380. [PMID: 36427461 DOI: 10.1016/j.watres.2022.119380] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/27/2022] [Accepted: 11/17/2022] [Indexed: 06/16/2023]
Abstract
Rivers are globally significant natural sources of atmospheric methane (CH4). However, the effect of land use changes on riverine CH4 dynamics, particularly in tropical zones, remain ambiguous, yet important to predict and anticipate the present and future contribution of rivers to the global CH4 budget. The present study examines the magnitude and drivers of riverine CH4 concentration and emission in the tropical Krishna River (KR) basin, India. The large spatial variability of CH4 concentration (0.03 to 185.34 μmol L -1) and emissions (0.04 mmol m-2 d-1 to 1666.24 mmol m-2 d-1) in the KR basin was linked to the site-specific features of the catchments through which rivers are draining. Several fold higher CH4 concentration and emission was observed for the urban river sites (64.63 ± 53.17 µmol L-1 and 294.15 ± 371.52 mmol m2 d-1, respectively) than the agricultural (1.05 ± 2.22 µmol L-1 and 3.45 ± 9.72 mmol m2 d-1, respectively) and forested (0.49 ± 0.23 µmol L-1 and 1.26 ± 0.73 mmol m2 d-1, respectively) sites. The concentrations of dissolved oxygen, total phosphorus, and Chlorophyll-a were significant hydrochemical variables strongly coupled with the dissolved CH4 concentrations. On the other hand, percentage of built-up area emerged as the most important landscape-level driver indicating that urbanization has an overriding effect on riverine CH4 concentration in the agriculture dominated KR basin. Our study supports the growing notion that tropical urban rivers are hotspot of CH4 emission. Furthermore, we show that the pattern of increasing in riverine CH4 concentration with built-up area (%) is a general feature of Asian river basins. As the urban land cover and population following an exponential increase, Asian rivers might contribute substantially to the regional and global CH4 budget.
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Affiliation(s)
- Latika Patel
- Department of Environmental Science, SRM University AP, Mangalagiri, Amaravati, Andhra Pradesh 522502, India
| | - Rashmi Singh
- Department of Environmental Science, SRM University AP, Mangalagiri, Amaravati, Andhra Pradesh 522502, India
| | - Shoji D Thottathil
- Department of Environmental Science, SRM University AP, Mangalagiri, Amaravati, Andhra Pradesh 522502, India.
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Wang X, Yu L, Liu T, He Y, Wu S, Chen H, Yuan X, Wang J, Li X, Li H, Que Z, Qing Z, Zhou T. Methane and nitrous oxide concentrations and fluxes from heavily polluted urban streams: Comprehensive influence of pollution and restoration. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 313:120098. [PMID: 36075337 DOI: 10.1016/j.envpol.2022.120098] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
Streams draining urban areas are usually regarded as hotspots of methane (CH4) and nitrous oxide (N2O) emissions. However, little is known about the coupling effects of watershed pollution and restoration on CH4 and N2O emission dynamics in heavily polluted urban streams. This study investigated the CH4 and N2O concentrations and fluxes in six streams that used to be heavily polluted but have undergone different watershed restorations in Southwest China, to explore the comprehensive influences of pollution and restoration. CH4 and N2O concentrations in the six urban streams ranged from 0.12 to 21.32 μmol L-1 and from 0.03 to 2.27 μmol L-1, respectively. The calculated diffusive fluxes of CH4 and N2O were averaged of 7.65 ± 9.20 mmol m-2 d-1 and 0.73 ± 0.83 mmol m-2 d-1, much higher than those in most previous reports. The heavily polluted streams with non-restoration had 7.2 and 7.8 times CH4 and N2O concentrations higher than those in the fully restored streams, respectively. Particularly, CH4 and N2O fluxes in the fully restored streams were 90% less likely than those found in the unrestored ones. This result highlighted that heavily polluted urban streams with high pollution loadings were indeed hotspots of CH4 and N2O emissions throughout the year, while comprehensive restoration can effectively weaken their emission intensity. Sewage interception and nutrient removal, especially N loadings reduction, were effective measures for regulating the dynamics of CH4 and N2O emissions from the heavily polluted streams. Based on global and regional integration, it further elucidated that increasing environment investments could significantly improve water quality and mitigate CH4 and N2O emissions in polluted urban streams. Overall, our study emphasized that although urbanization could inevitably strengthen riverine CH4 and N2O emissions, effective eco-restoration can mitigate the crisis of riverine greenhouse gas emissions.
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Affiliation(s)
- Xiaofeng Wang
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China.
| | - Lele Yu
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Tingting Liu
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200241, China
| | - Yixin He
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan, 624400, China
| | - Shengnan Wu
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Huai Chen
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan, 624400, China
| | - Xingzhong Yuan
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400030, China
| | - Jilong Wang
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Xianxiang Li
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Hang Li
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Ziyi Que
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Zhaoyin Qing
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
| | - Ting Zhou
- Chongqing Key Laboratory of Wetland Science Research of the Upper Reaches of the Yangtze River, Chongqing, 401331, China; Three Gorges Reservoir Area Earth Surface Ecological Processes of Chongqing Observation and Research Station, Chongqing, 405400, China; School of Geography and Tourism, Chongqing Normal University, Chongqing, 400047, China
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Gu C, Waldron S, Bass AM. Anthropogenic land use and urbanization alter the dynamics and increase the export of dissolved carbon in an urbanized river system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 846:157436. [PMID: 35863573 DOI: 10.1016/j.scitotenv.2022.157436] [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: 03/22/2022] [Revised: 07/07/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Greenhouse gas emissions from urban rivers play a crucial role in global carbon (C) cycling, this is tightly linked to dissolved C in rivers but research gaps remain. The effects of urbanization and anthropogenic land-use change on riverine dissolved carbon dynamics were investigated in a temperate river, the River Kelvin in UK. The river was constantly a source of methane (CH4) and carbon dioxide (CO2) to the atmosphere (excess concentration of CH4 ranged from 13 to 4441 nM, and excess concentration of CO2 ranged from 2.6 to 230.6 μM), and dissolved C concentrations show significant spatiotemporal variations (p < 0.05), reflecting a variety of proximal sources and controls. For example, the concentration variation of dissolved CH4 and dissolved CO2 were heavily controlled by the proximity of coal mine infrastructure in the tributary near the river head (~ 2 km) but were more likely controlled by adjacent landfills in the midstream section of the rivers main channel. Concentration and isotopic evidence revealed an important anthropogenic control on the riverine export of CO2 and dissolved organic carbon (DOC). However, dissolved inorganic carbon (DIC) input via groundwater at the catchment scale primarily controlled the dynamics of riverine DIC. Furthermore, the positive relationship between the isotopic composition of DIC and CO2 (r = 0.79, p < 0.01) indicates the DIC pool was at times also significantly influenced by soil respiratory CO2. Both DIC and DOC showed a weak but significant correlation with the proportion of urban/suburban land use, suggesting increased dissolved C export resulting from urbanization. This research elucidates a series of potentially key effects anthropogenic activities and land-use practices can have on riverine C dynamics and highlights the need for future consideration of the direct effects urbanization has on riverine C dynamics.
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Affiliation(s)
- Chao Gu
- School of Geographical & Earth Science, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Susan Waldron
- School of Geographical & Earth Science, University of Glasgow, Glasgow G12 8QQ, UK
| | - Adrian Michael Bass
- School of Geographical & Earth Science, University of Glasgow, Glasgow G12 8QQ, UK
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Zheng Y, Wu S, Xiao S, Yu K, Fang X, Xia L, Wang J, Liu S, Freeman C, Zou J. Global methane and nitrous oxide emissions from inland waters and estuaries. GLOBAL CHANGE BIOLOGY 2022; 28:4713-4725. [PMID: 35560967 DOI: 10.1111/gcb.16233] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 04/24/2022] [Indexed: 06/15/2023]
Abstract
Inland waters (rivers, reservoirs, lakes, ponds, streams) and estuaries are significant emitters of methane (CH4 ) and nitrous oxide (N2 O) to the atmosphere, while global estimates of these emissions have been hampered due to the lack of a worldwide comprehensive data set of CH4 and N2 O flux components. Here, we synthesize 2997 in-situ flux or concentration measurements of CH4 and N2 O from 277 peer-reviewed publications to estimate global CH4 and N2 O emissions from inland waters and estuaries. Inland waters including rivers, reservoirs, lakes, and streams together release 95.18 Tg CH4 year-1 (ebullition plus diffusion) and 1.48 Tg N2 O year-1 (diffusion) to the atmosphere, yielding an overall CO2 -equivalent emission total of 3.06 Pg CO2 year-1 . The estimate of CH4 and N2 O emissions represents roughly 60% of CO2 emissions (5.13 Pg CO2 year-1 ) from these four inland aquatic systems, among which lakes act as the largest emitter for both CH4 and N2 O. Ebullition showed as a dominant flux component of CH4 , contributing up to 62%-84% of total CH4 fluxes across all inland waters. Chamber-derived CH4 emission rates are significantly greater than those determined by diffusion model-based methods for commonly capturing of both diffusive and ebullitive fluxes. Water dissolved oxygen (DO) showed as a dominant factor among all variables to influence both CH4 (diffusive and ebullitive) and N2 O fluxes from inland waters. Our study reveals a major oversight in regional and global CH4 budgets from inland waters, caused by neglecting the dominant role of ebullition pathways in those emissions. The estimated indirect N2 O EF5 values suggest that a downward refinement is required in current IPCC default EF5 values for inland waters and estuaries. Our findings further indicate that a comprehensive understanding of the magnitude and patterns of CH4 and N2 O emissions from inland waters and estuaries is essential in defining the way of how these aquatic systems will shape our climate.
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Affiliation(s)
- Yajing Zheng
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shuang Wu
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shuqi Xiao
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Kai Yu
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Xiantao Fang
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Longlong Xia
- Institute of Meteorology and Climate Research, Atmospheric Environmental Research, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Jinyang Wang
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
| | - Shuwei Liu
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, China
| | - Chris Freeman
- School of Natural Sciences, Bangor University, Bangor, UK
| | - Jianwen Zou
- Key Laboratory of Low-carbon and Green Agriculture in Southeastern China, Ministry of Agriculture and Rural Affairs, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, Nanjing, China
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing, China
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9
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Roth F, Sun X, Geibel MC, Prytherch J, Brüchert V, Bonaglia S, Broman E, Nascimento F, Norkko A, Humborg C. High spatiotemporal variability of methane concentrations challenges estimates of emissions across vegetated coastal ecosystems. GLOBAL CHANGE BIOLOGY 2022; 28:4308-4322. [PMID: 35340089 PMCID: PMC9540812 DOI: 10.1111/gcb.16177] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
Abstract
Coastal methane (CH4 ) emissions dominate the global ocean CH4 budget and can offset the "blue carbon" storage capacity of vegetated coastal ecosystems. However, current estimates lack systematic, high-resolution, and long-term data from these intrinsically heterogeneous environments, making coastal budgets sensitive to statistical assumptions and uncertainties. Using continuous CH4 concentrations, δ13 C-CH4 values, and CH4 sea-air fluxes across four seasons in three globally pervasive coastal habitats, we show that the CH4 distribution is spatially patchy over meter-scales and highly variable in time. Areas with mixed vegetation, macroalgae, and their surrounding sediments exhibited a spatiotemporal variability of surface water CH4 concentrations ranging two orders of magnitude (i.e., 6-460 nM CH4 ) with habitat-specific seasonal and diurnal patterns. We observed (1) δ13 C-CH4 signatures that revealed habitat-specific CH4 production and consumption pathways, (2) daily peak concentration events that could change >100% within hours across all habitats, and (3) a high thermal sensitivity of the CH4 distribution signified by apparent activation energies of ~1 eV that drove seasonal changes. Bootstrapping simulations show that scaling the CH4 distribution from few samples involves large errors, and that ~50 concentration samples per day are needed to resolve the scale and drivers of the natural variability and improve the certainty of flux calculations by up to 70%. Finally, we identify northern temperate coastal habitats with mixed vegetation and macroalgae as understudied but seasonally relevant atmospheric CH4 sources (i.e., releasing ≥ 100 μmol CH4 m-2 day-1 in summer). Due to the large spatial and temporal heterogeneity of coastal environments, high-resolution measurements will improve the reliability of CH4 estimates and confine the habitat-specific contribution to regional and global CH4 budgets.
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Affiliation(s)
- Florian Roth
- Baltic Sea CentreStockholm UniversityStockholmSweden
- Tvärminne Zoological StationUniversity of HelsinkiHankoFinland
| | - Xiaole Sun
- Baltic Sea CentreStockholm UniversityStockholmSweden
- Center of Deep Sea ResearchInstitute of OceanologyChinese Academy of SciencesQingdaoChina
| | | | - John Prytherch
- Department of MeteorologyStockholm UniversityStockholmSweden
| | - Volker Brüchert
- Department of Geological SciencesStockholm UniversityStockholmSweden
- Bolin Centre for Climate ResearchStockholm UniversityStockholmSweden
| | - Stefano Bonaglia
- Department of Marine SciencesUniversity of GothenburgGothenburgSweden
| | - Elias Broman
- Baltic Sea CentreStockholm UniversityStockholmSweden
- Department of EcologyEnvironment and Plant SciencesStockholm UniversityStockholmSweden
| | - Francisco Nascimento
- Baltic Sea CentreStockholm UniversityStockholmSweden
- Department of EcologyEnvironment and Plant SciencesStockholm UniversityStockholmSweden
| | - Alf Norkko
- Baltic Sea CentreStockholm UniversityStockholmSweden
- Tvärminne Zoological StationUniversity of HelsinkiHankoFinland
| | - Christoph Humborg
- Baltic Sea CentreStockholm UniversityStockholmSweden
- Tvärminne Zoological StationUniversity of HelsinkiHankoFinland
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10
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Nguyen AT, Némery J, Gratiot N, Dao TS, Le TTM, Baduel C, Garnier J. Does eutrophication enhance greenhouse gas emissions in urbanized tropical estuaries? ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 303:119105. [PMID: 35276252 DOI: 10.1016/j.envpol.2022.119105] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/24/2022] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
Estuaries are considered as important sources of the global emission of greenhouse gases (GHGs). Urbanized estuaries often experience eutrophication under strong anthropogenic activities. Eutrophication can enhance phytoplankton abundance, leading to carbon dioxide (CO2) consumption in the water column. Only a few studies have evaluated the relationship between GHGs and eutrophication in estuaries. In this study, we assessed the concentrations and fluxes of CO2, methane (CH4) and nitrous oxide (N2O) in combination with a suite of biogeochemical variables in four sampling campaigns over two years in a highly urbanized tropical estuary in Southeast Asia (the Saigon River Estuary, Vietnam). The impact of eutrophication on GHGs was evaluated through several statistical methods and interpreted by biological processes. The average concentrations of CO2, CH4 and N2O at the Saigon River in 2019-2020 were 3174 ± 1725 μgC-CO2 L-1, 5.9 ± 16.8 μgC-CH4 L-1 and 3.0 ± 4.8 μgN-N2O L-1, respectively. Their concentrations were 13-18 times, 52-332 times, and 9-37 times higher than the global mean concentrations of GHGs, respectively. While CO2 concentration had no clear seasonal pattern, N2O and CH4 concentrations significantly differed between the dry and the rainy seasons. The increase in eutrophication status along the dense urban area was linearly correlated with the increase in GHGs concentrations. The presence of both nitrification and denitrification resulted in elevated N2O concentrations in this urban area of the estuary. The high concentration of CO2 was contributed by the high concentration of organic carbon and mineralization process. GHGs fluxes at the Saigon River Estuary were comparable to other urbanized estuaries regardless of climatic condition. Control of eutrophication in urbanized estuaries through the implantation of efficient wastewater treatment facilities will be an effective solution in mitigating the global warming potential caused by estuarine emissions.
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Affiliation(s)
- An Truong Nguyen
- Univ. Grenoble Alpes, IRD, CNRS, Grenoble INP, IGE(1), F-38000, Grenoble, France; CARE, Ho Chi Minh City University of Technology (HCMUT), VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Viet Nam.
| | - Julien Némery
- Univ. Grenoble Alpes, IRD, CNRS, Grenoble INP, IGE(1), F-38000, Grenoble, France; CARE, Ho Chi Minh City University of Technology (HCMUT), VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Viet Nam
| | - Nicolas Gratiot
- Univ. Grenoble Alpes, IRD, CNRS, Grenoble INP, IGE(1), F-38000, Grenoble, France; CARE, Ho Chi Minh City University of Technology (HCMUT), VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Viet Nam
| | - Thanh-Son Dao
- CARE, Ho Chi Minh City University of Technology (HCMUT), VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Viet Nam; Vietnam National University, Ho Chi Minh City, Viet Nam
| | - Tam Thi Minh Le
- CARE, Ho Chi Minh City University of Technology (HCMUT), VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Viet Nam
| | - Christine Baduel
- Univ. Grenoble Alpes, IRD, CNRS, Grenoble INP, IGE(1), F-38000, Grenoble, France; CARE, Ho Chi Minh City University of Technology (HCMUT), VNU-HCM, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Viet Nam
| | - Josette Garnier
- Sorbonne Université, CNRS, EPHE, UMR 7619 Metis, BP 123, Tour 56-55, Etage 4, 4 Place Jussieu, 7500, Paris, France
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11
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Spatiotemporal Geostatistical Analysis and Global Mapping of CH4 Columns from GOSAT Observations. REMOTE SENSING 2022. [DOI: 10.3390/rs14030654] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Methane (CH4) is one of the most important greenhouse gases causing the global warming effect. The mapping data of atmospheric CH4 concentrations in space and time can help us better to understand the characteristics and driving factors of CH4 variation as to support the actions of CH4 emission reduction for preventing the continuous increase of atmospheric CH4 concentrations. In this study, we applied a spatiotemporal geostatistical analysis and prediction to develop an approach to generate the mapping CH4 dataset (Mapping-XCH4) in 1° grid and three days globally using column averaged dry air mole fraction of CH4 (XCH4) data derived from observations of the Greenhouse Gases Observing Satellite (GOSAT) from April 2009 to April 2020. Cross-validation for the spatiotemporal geostatistical predictions showed better correlation coefficient of 0.97 and a mean absolute prediction error of 7.66 ppb. The standard deviation is 11.42 ppb when comparing the Mapping-XCH4 data with the ground measurements from the total carbon column observing network (TCCON). Moreover, we assessed the performance of this Mapping-XCH4 dataset by comparing with the XCH4 simulations from the CarbonTracker model and primarily investigating the variations of XCH4 from April 2009 to April 2020. The results showed that the mean annual increase in XCH4 was 7.5 ppb/yr derived from Mapping-XCH4, which was slightly greater than 7.3 ppb/yr from the ground observational network during the past 10 years from 2010. XCH4 is larger in South Asia and eastern China than in the other regions, which agrees with the XCH4 simulations. The Mapping-XCH4 shows a significant linear relationship and a correlation coefficient of determination (R2) of 0.66, with EDGAR emission inventories over Monsoon Asia. Moreover, we found that Mapping-XCH4 could detect the reduction of XCH4 in the period of lockdown from January to April 2020 in China, likely due to the COVID-19 pandemic. In conclusion, we can apply GOSAT observations over a long period from 2009 to 2020 to generate a spatiotemporally continuous dataset globally using geostatistical analysis. This long-term Mpping-XCH4 dataset has great potential for understanding the spatiotemporal variations of CH4 concentrations induced by natural processes and anthropogenic emissions at a global and regional scale.
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12
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Cotovicz LC, Ribeiro RP, Régis CR, Bernardes M, Sobrinho R, Vidal LO, Tremmel D, Knoppers BA, Abril G. Greenhouse gas emissions (CO 2 and CH 4) and inorganic carbon behavior in an urban highly polluted tropical coastal lagoon (SE, Brazil). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:38173-38192. [PMID: 33723789 DOI: 10.1007/s11356-021-13362-2] [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: 09/06/2020] [Accepted: 03/04/2021] [Indexed: 06/12/2023]
Abstract
Increasing eutrophication of coastal waters generates disturbances in greenhouse gas (GHG) concentrations and emissions to the atmosphere that are still poorly documented, particularly in the tropics. Here, we investigated the concentrations and diffusive fluxes of carbon dioxide (CO2) and methane (CH4) in the urban-dominated Jacarepagua Lagoon Complex (JLC) in Southeastern Brazil. This lagoonal complex receives highly polluted freshwater and shows frequent occurrences of anoxia and hypoxia and dense phytoplankton blooms. Between 2017 and 2018, four spatial surveys were performed (dry and wet conditions), with sampling in the river waters that drain the urban watershed and in the lagoon waters with increasing salinities. Strong oxygen depletion was found in the rivers, associated with extremely high values of partial pressure of CO2 (pCO2; up to 20,417 ppmv) and CH4 concentrations (up to 288,572 nmol L-1). These high GHG concentrations are attributed to organic matter degradation from untreated domestic effluents mediated by aerobic and anaerobic processes, with concomitant production of total alkalinity (TA) and dissolved inorganic carbon (DIC). In the lagoon, GHG concentrations decreased mainly due to dilution with seawater and degassing. In addition, the phytoplankton growth and CH4 oxidation apparently consumed some CO2 and CH4, respectively. TA concentrations showed a marked minimum at salinity of ~20 compared to the two freshwater and marine end members, indicating processes of re-oxidation of inorganic reduced species from the low-salinity region, such as ammonia, iron, and/or sulfides. Diffusive emissions of gases from the entire lagoon ranged from 22 to 48 mmol C m-2 d-1 for CO2 and from 2.2 to 16.5 mmol C m-2 d-1 for CH4. This later value is among the highest documented in coastal waters. In terms of global warming potential (GWP) and CO2 equivalent emissions (CO2-eq), the diffusive emissions of CH4 were higher than those of CO2. These results highlight that highly polluted coastal ecosystems are hotspots of GHG emissions to the atmosphere, which may become increasingly significant in future global carbon budgets.
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Affiliation(s)
- Luiz C Cotovicz
- Programa de Geoquímica, Universidade Federal Fluminense, Niterói, RJ, Brazil.
- Instituto de Ciências do Mar, Universidade Federal do Ceará, Fortaleza, CE, Brazil.
| | - Renato P Ribeiro
- Centro Experimental de Monitoramento e Mitigação Ambiental (CEMMA), Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro (IFRJ), Nilópolis, RJ, Brasil
| | | | - Marcelo Bernardes
- Programa de Geoquímica, Universidade Federal Fluminense, Niterói, RJ, Brazil
| | - Rodrigo Sobrinho
- Programa de Geoquímica, Universidade Federal Fluminense, Niterói, RJ, Brazil
| | - Luciana Oliveira Vidal
- Laboratório de Ciências Ambientais, Centro de Biociências e Biotecnologia Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, Brazil
| | - Daniel Tremmel
- Programa de Geoquímica, Universidade Federal Fluminense, Niterói, RJ, Brazil
| | - Bastiaan A Knoppers
- Programa de Geoquímica, Universidade Federal Fluminense, Niterói, RJ, Brazil
| | - Gwenaël Abril
- Programa de Geoquímica, Universidade Federal Fluminense, Niterói, RJ, Brazil
- Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), UMR 7208, Muséum National d'Histoire Naturelle, CNRS, IRD, SU, UCN, UA, Paris, France
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13
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Abbasi SA, Dhanuja C, Abbasi T. Emission of greenhouse gases from Indian wetlands: an overview. Trop Ecol 2021. [DOI: 10.1007/s42965-021-00165-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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14
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Guo X, Wang J. Projecting the sorption capacity of heavy metal ions onto microplastics in global aquatic environments using artificial neural networks. JOURNAL OF HAZARDOUS MATERIALS 2021; 402:123709. [PMID: 33254753 DOI: 10.1016/j.jhazmat.2020.123709] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 07/26/2020] [Accepted: 08/12/2020] [Indexed: 05/22/2023]
Abstract
Microplastics pollution and their interaction with heavy metal ions have gained global concern. It is essential to develop models to predict the sorption capacity of heavy metal ions onto microplastics in global aquatic environments, and to connect the laboratory study results with the field measurement results. In this paper, the artificial neural networks (ANN) models were established based on literature data. for The results showed that the ANN model could predict the sorption capacity of heavy metal ions (including Cd, Pb, Cr, Cu, and Zn) onto microplastics in the global environments with high correlation coefficient (R) values (0.926∼0.994). The predicted sorption capacity was influenced by the initial concentration of heavy metal ions and the salinity in surrounding water. The predicted sorption capacity in rivers and lakes was higher than that in the ocean. Aged microplastics had higher affinity to heavy metal ions than virgin microplastics. The predicted sorption capacity of Cd, Pb, and Zn ions onto large microplastics (5 mm) was less than 0.12 μg/g. The predicted amount was in agreement with the field measurement results, suggesting that the laboratory studies can provide useful information for projecting the sorption capacity of heavy metal ions onto microplastics in global aquatic environments.
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Affiliation(s)
- Xuan Guo
- Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing 100084, China
| | - Jianlong Wang
- Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing 100084, China; Beijing Key Laboratory of Radioactive Waste Treatment, INET, Tsinghua University, Beijing 100084, China.
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15
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Yang P, Yang H, Sardans J, Tong C, Zhao G, Peñuelas J, Li L, Zhang Y, Tan L, Chun KP, Lai DYF. Large Spatial Variations in Diffusive CH 4 Fluxes from a Subtropical Coastal Reservoir Affected by Sewage Discharge in Southeast China. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14192-14203. [PMID: 33118825 DOI: 10.1021/acs.est.0c03431] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Coastal reservoirs are potentially CH4 emission hotspots owing to their biogeochemical role as the sinks of anthropogenic carbon and nutrients. Yet, the fine-scale spatial variations in CH4 concentrations and fluxes in coastal reservoirs remain poorly understood, hampering an accurate determination of reservoir CH4 budgets. In this study, we examined the spatial variability of diffusive CH4 fluxes and their drivers at a subtropical coastal reservoir in southeast China using high spatial resolution measurements of dissolved CH4 concentrations and physicochemical properties of the surface water. Overall, this reservoir acted as a consistent source of atmospheric CH4, with a mean diffusive flux of 16.1 μmol m-2 h-1. The diffusive CH4 flux at the reservoir demonstrated considerable spatial variations, with the coefficients of variation ranging between 199 and 426% over the three seasons. The shallow water zone (comprising 23% of the reservoir area) had a disproportionately high contribution (56%) to the whole-reservoir diffusive CH4 emissions. Moreover, the mean CH4 flux in the sewage-affected sectors was significantly higher than that in the nonsewage-affected sectors. The results of bootstrap analysis further showed that increasing the sample size from 10 to 100 significantly reduced the relative standard deviation of mean diffusive CH4 flux from 73.7 to 3.4%. Our findings highlighted the role of sewage in governing the spatial variations in reservoir CH4 emissions and the importance of high spatial resolution data to improve the reliability of flux estimates for assessing the contribution of reservoirs to the regional and global CH4 budgets.
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Affiliation(s)
- Ping Yang
- Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Normal University, Fuzhou 350007, China
- School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
| | - Hong Yang
- College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, China
- Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China
- Department of Geography and Environmental Science, University of Reading, Reading RG6 6AB U.K
| | - Jordi Sardans
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia 08193, Spain
- CREAF, Cerdanyola del Vallès, Catalonia 08193, Spain
| | - Chuan Tong
- Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, Fujian Normal University, Fuzhou 350007, China
- School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
| | - Guanghui Zhao
- School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Catalonia 08193, Spain
- CREAF, Cerdanyola del Vallès, Catalonia 08193, Spain
| | - Ling Li
- School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
| | - Yifei Zhang
- School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
| | - Lishan Tan
- School of Geographical Sciences, East China Normal University, Shanghai 200241, China
| | - Kwok Pan Chun
- Department of Geography, Hong Kong Baptist University, Hong Kong, China
| | - Derrick Y F Lai
- Department of Geography and Resource Management, The Chinese University of Hong Kong, Hong Kong, China
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16
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Methane Levels of a River Network in Wuxi City, China and Response to Water Governance. WATER 2020. [DOI: 10.3390/w12092617] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The majority of rivers are a CH4 source that accounts for an important proportion of annual global emissions. However, CH4 evasion from urban river networks has received disproportionately less attention than their contribution. The effect of water governance on water quality and CH4 emission in urban areas remains unclear. Water quality, CH4 concentrations, and fluxes from a river network in Binhu District, Wuxi City, and their response to water governance were analyzed in this study. CH4 concentrations in the investigated rivers ranged from 0.05 μmol L−1 to 16.37 μmol L−1 (2.47 ± 4.5 μmol L−1, medium 0.23 μmol L−1), and CH4 diffusive fluxes were 75.55 ± 171.78 μmol m−2 h−1 with a medium of 6.50 μmol m−2 h−1. CH4 concentration showed a significant correlation with water quality parameters, especially for NH3–N (r = 0.84, p < 0.001). Significant differences in water quality and CH4 levels were found between sites that had conducted water management and those that continued to exhibit poor water quality. Our analysis showed that rivers under water governance have a positive tendency toward water ecological restoration, and a significant decrease in CH4 efflux to the air can be achieved after extensive and intensified water governance.
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17
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Wang R, Zhang H, Zhang W, Zheng X, Butterbach-Bahl K, Li S, Han S. An urban polluted river as a significant hotspot for water-atmosphere exchange of CH 4 and N 2O. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 264:114770. [PMID: 32559861 DOI: 10.1016/j.envpol.2020.114770] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/12/2020] [Accepted: 05/06/2020] [Indexed: 06/11/2023]
Abstract
Polluted urban river systems might be a strong source of atmospheric methane (CH4) and nitrous oxide (N2O), but so far only a few urban river systems have been quantified with regard to their source strength for greenhouse gases (GHGs). In this study, we measured loads of dissolved inorganic nitrogen and organic carbon, dissolved oxygen (DO) concentrations, and fluxes of CH4 and N2O from an urban river in Beijing, China during the course of an entire year. Fluxes calculated using the floating chamber approach or via the diffusion method with measurements of river water GHG concentrations showed comparable temporal variations. However, the flux magnitude based on the diffusion method was found to strongly depend on the underlying parameterization of the gas transfer velocity. In view of the large differences while applying different methodologies to estimate surface water GHG fluxes further studies are still needed to prove and eventually quantify the systematic errors which are likely caused by either the chamber technique or the approaches of individual diffusion models. For both the floating chamber and the diffusion-based flux estimates, strong seasonal variations in CH4 and N2O fluxes from the river surface were observed, with fluxes ranging from 3 to 8374 μg C m-2 h-1 for CH4 and 1-3986 μg N m-2 h-1 for N2O. The CH4 fluxes were strongly negatively correlated with the DO concentration (P < 0.01). The highest N2O fluxes were observed at times with low CH4 fluxes (i.e., in spring and autumn). Annual CH4 and N2O fluxes totaled 19.3-79.4 and 17.4-44.8 kg C (N) ha-1 yr-1, respectively. These high fluxes are in agreement with estimates from the few other studies carried out for urban river systems to date and indicate that urban polluted river systems are a significant regional source of atmospheric GHGs.
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Affiliation(s)
- Rui Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP-CAS), Beijing, 100029, PR China
| | - Han Zhang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP-CAS), Beijing, 100029, PR China; School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin, 300387, PR China
| | - Wei Zhang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP-CAS), Beijing, 100029, PR China.
| | - Xunhua Zheng
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP-CAS), Beijing, 100029, PR China; College of Earth and Planetary Science, University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Klaus Butterbach-Bahl
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP-CAS), Beijing, 100029, PR China; Institute of Meteorology and Climate Research, Atmospheric Environmental Research, Karlsruhe Institute of Technology, Garmisch-Partenkirchen, 82467, Germany
| | - Siqi Li
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP-CAS), Beijing, 100029, PR China
| | - Shenghui Han
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences (IAP-CAS), Beijing, 100029, PR China
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18
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Qin X, Li Y, Wan Y, Fan M, Liao Y, Li Y, Wang B, Gao Q. Diffusive flux of CH 4 and N 2O from agricultural river networks: Regression tree and importance analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 717:137244. [PMID: 32065892 DOI: 10.1016/j.scitotenv.2020.137244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/17/2020] [Accepted: 02/09/2020] [Indexed: 06/10/2023]
Abstract
River networks in subtropical agricultural hilly region become an inconvenient greenhouse gas (GHG, methane and nitrous oxide) source because of the influence of human activities, which has caused large uncertainties for refinement of national GHG inventories and their global budget. Based on field monitoring experiments at high temporal resolution, we employed regression tree and importance analysis to identify quantitatively factors that influence the diffusive flux of GHGs to provide a scientific basis for reducing GHG emissions and controlling regional carbon and nitrogen losses. The results indicate that significant spatiotemporal variation of methane (CH4) nitrous oxide (N2O) diffusion occurs in all the four reaches (W1, W2, W3 and W4) of Tuojia river networks. Among them, W1 contributed lowest CH4 (22.55 μg C m-2 h-1) and N2O (5.00 μg N m-2 h-1) diffusive flux than the other three (P < 0.05), while W4 offered highest CH4 (166.15 μg C m-2 h-1) and N2O (30.47 μg N m-2 h-1) diffusive flux but with no statistically significant difference between W2 and W3 due to homogeneous extraneous nutrition loading into the two reaches. W4 also contributed largest cumulative flux of CH4 (14.55 kg C ha-1 yr-1) and N2O (2.69 kg N ha-1 yr-1) in Tuojia River networks (P < 0.05). Furthermore, the regression tree and importance analysis indicate that, in the anaerobic environment, dissolved oxygen saturation controlled the production and diffusion for both CH4 and N2O. The findings of this investigation highlighted that decision support tools provide an effective pathway to enhance the GHG mitigation technology research in agroecosystems and simultaneously shed light on the global campaign on refinement of national GHG inventories as well as regional nutrient management.
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Affiliation(s)
- Xiaobo Qin
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Key Laboratory for Agro-Environment, Ministry of Agriculture and Rural Affairs, No. 12 Zhongguancun South Street, Haidian district, Beijing 100081, China.
| | - Yu'e Li
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Key Laboratory for Agro-Environment, Ministry of Agriculture and Rural Affairs, No. 12 Zhongguancun South Street, Haidian district, Beijing 100081, China
| | - Yunfan Wan
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Key Laboratory for Agro-Environment, Ministry of Agriculture and Rural Affairs, No. 12 Zhongguancun South Street, Haidian district, Beijing 100081, China
| | - Meirong Fan
- Changsha Environmental Protection College, Changsha 410004, China
| | - Yulin Liao
- Soils and Fertilizer Institute of Hunan Province, Changsha 410125, China
| | - Yong Li
- Key Laboratory of Agro-ecological Processes in Subtropical Regions, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China
| | - Bin Wang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Key Laboratory for Agro-Environment, Ministry of Agriculture and Rural Affairs, No. 12 Zhongguancun South Street, Haidian district, Beijing 100081, China
| | - Qingzhu Gao
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Key Laboratory for Agro-Environment, Ministry of Agriculture and Rural Affairs, No. 12 Zhongguancun South Street, Haidian district, Beijing 100081, China
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19
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Human Activities Inducing High CH4 Diffusive Fluxes in an Agricultural River Catchment in Subtropical China. SUSTAINABILITY 2020. [DOI: 10.3390/su12052114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Methane (CH4) is one of the key greenhouse gases (GHGs) in the atmosphere with current concentration of 1859 ppb in 2017 due to climate change and anthropogenic activities. Rivers are of increasing concern due to sources of atmospheric CH4. However, knowledge and data limitations exist for field studies of subtropical agricultural river catchments, particularly in southern China. The headspace balance method and the diffusion model method were employed to assess spatiotemporal variations of CH4 diffusive fluxes from April 2015 to January 2016 in four order reaches (S1, S2, S3, and S4) of the Tuojia River, Hunan, China. Results indicated that both the dissolved concentrations and diffusive fluxes of CH4 showed obvious spatiotemporal variations. The observed mean concentration and diffusive flux of CH4 were 0.40 ± 0.02 μmol L−1 and 41.19 ± 2.50 µg m−2 h−1, respectively, showing the river to be a strong source of atmospheric CH4. The CH4 diffusive fluxes during the rice-growing seasons were significantly greater than the winter fallow season (an increase of 80.26%). The spatial distribution of CH4 diffusive fluxes increased gradually from (17.58 ± 1.42) to (55.56 ± 4.32) µg m−2 h−1 due to the organic and nutrient loading into the river waterbodies, with the maximum value at location S2 and the minimum value at location S1. Correlation analysis showed that the CH4 diffusive fluxes exhibited a positive relationship with the dissolved organic carbon (DOC), salinity, and water temperature (WT), while a negative correlation occurred between CH4 diffusive fluxes and the dissolved oxygen (DO) concentration, as well as the pH value. Our findings highlighted that a good understanding of exogenous nutrient loading in agricultural catchments will clarify the influence of human activities on river water quality and then constrain the global CH4 budget.
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20
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Saleem Raja UK, Ebenezer V, Kumar A, Sanjeevi P, Murugesan M. Mass mortality of fish and water quality assessment in the tropical Adyar estuary, South India. ENVIRONMENTAL MONITORING AND ASSESSMENT 2019; 191:512. [PMID: 31346834 DOI: 10.1007/s10661-019-7636-4] [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: 02/22/2019] [Accepted: 07/02/2019] [Indexed: 06/10/2023]
Abstract
Mass mortality of fishes was reported at the Adyar estuary, South India, during November 2017. The probable reasons for fish mortality are analyzed in this paper. Critical assessments on water quality parameters including the metal concentrations, nutrients, and histology of gills and liver of fish (Mugil cephalus) isolated from the impact zone were performed. Among the metals observed, chromium showed levels (3.64 ± 0.001 mg L-1) much above the average permissible limits (0.1 mg L-1). The measured values of physico-chemical parameters in the impact zone are as follows: dissolved oxygen 4.7 ± 0.22 mg L-1, total alkalinity 132 ± 4 CaCO3 mg L-1, salinity 5.3 ± 0.3 PSU, temperature 27.8 ± 0.16 °C, nitrate, 1.66 ± 0.48 mg L-1, nitrite 0.01 ± 0.0008 mg L-1, ammonia 0.03 ± 0.001 mg L-1, phosphate 1.52 ± 0.002 mg L-1, and silicate 13.85 ± 3.1 mg L-1. The low salinity could have escalated the toxicity of the metal. In addition, histology of gills and liver showed cellular necrosis, epithelial lifting, hyperplasia, edema, mucous cell proliferation in the gills, cytoplasmic vacuolation of hepatocytes, and degeneration of liver which reveal that chromium toxicity is the most probable cause for mass mortality.
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Affiliation(s)
- Umer Khalifa Saleem Raja
- Center for Climate Change Studies, International Research Center, Sathyabama Institute of Science and Technology, Chennai, India
| | - Vinitha Ebenezer
- Center for Climate Change Studies, International Research Center, Sathyabama Institute of Science and Technology, Chennai, India.
| | - Amit Kumar
- Center for Climate Change Studies, International Research Center, Sathyabama Institute of Science and Technology, Chennai, India
| | - Prakash Sanjeevi
- Center for Climate Change Studies, International Research Center, Sathyabama Institute of Science and Technology, Chennai, India
| | - Murali Murugesan
- Environmental Research Laboratory, P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli, Tamil Nadu, 620020, India
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21
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Managing Municipal Wastewater Treatment to Control Nitrous Oxide Emissions from Tidal Rivers. WATER 2019. [DOI: 10.3390/w11061255] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Waste load allocation management models were developed for controlling nitrous oxide emissions from a tidal river. The decision variables were treatment levels at wastewater discharging stations and the rate of upstream water release. The simulation model for N2O emissions from the river was embedded in the optimization model and the problem was solved using the simulated annealing technique. In two of the models, the total cost was minimized, while in the third model, emissions from the river were minimized for a specified constraint on the available money. Proof-of-concept studies, with hypothetical scenarios for contaminant loading but realistic flow conditions corresponding to the Tyne River, UK, were carried out. It was found that the treatment cost could be reduced by 36% by treating wastewater discharges in the upper reaches more during the high tide as compared to during low tide. For the same level of N2O emissions, approximately 16.7% lesser costs could be achieved by not only treating the wastewater but also inducing dilution by releasing more water from the upstream side. It was also found that beyond a limit, N2O emissions cannot be reduced significantly by spending more money on treatment and water release.
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22
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Marescaux A, Thieu V, Garnier J. Carbon dioxide, methane and nitrous oxide emissions from the human-impacted Seine watershed in France. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 643:247-259. [PMID: 29936166 DOI: 10.1016/j.scitotenv.2018.06.151] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 06/12/2018] [Accepted: 06/12/2018] [Indexed: 06/08/2023]
Abstract
Greenhouse gas (GHG) emissions from rivers and lakes have been shown to contribute significantly to global carbon and nitrogen cycling. In temperate and human-impacted regions, simultaneous carbon dioxide, methane and nitrous oxide emissions from aquatic systems are poorly documented. We estimated carbon dioxide (CO2) concentrations in the Seine hydrosystem (71,730 km2, France) using direct measurements, and calculations of CO2 partial pressures from 14 field campaigns conducted between 2010 and 2017, and compared them to methane (CH4) and nitrous oxide (N2O) concentrations. In the main stem of the Seine River, CO2 showed the same spatial gradient as N2O and CH4 with peaks in concentration downstream from the arrival of effluents from wastewater treatment plants enriched in organic matter, thus favoring mineralization. It is likely that high CO2 concentrations upstream were due to organic carbon inputs from soils and enriched CO2 groundwater discharges, whereas high N2O and CH4 upstream values were likely due to denitrification in riparian wet areas and anoxic decomposition of organic matter-rich wetlands, respectively. In addition, seasonal variations in all three GHGs were observed with higher concentrations in summer when higher temperatures promote mineralization and low water reduces the dilution of organic matter mainly originating from WWTP effluents. GHG emissions were calculated and compared with agricultural and nonagricultural (urban, transport) fluxes in the basin. In the Seine River network, CO2 emissions dominated riverine GHG emissions, reaching 95.3%, while N2O and CH4 emissions accounted for 4.4% and 0.3%, respectively. These indirect emissions from the hydrosystem were estimated to account for 3.7% of the total GHG emissions from the basin that amounted to 61,284 Gg CO2eq yr-1. Comparatively, direct agricultural and nonagricultural GHG emissions were estimated at 23.3% and 73.0%., respectively.
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Affiliation(s)
- Audrey Marescaux
- Sorbonne Université, Université Pierre et Marie Curie, Centre National de la Recherche Scientifique, Institut Pierre Simon Laplace, UMR 7619 METIS, Paris, France.
| | - Vincent Thieu
- Sorbonne Université, Université Pierre et Marie Curie, Centre National de la Recherche Scientifique, Institut Pierre Simon Laplace, UMR 7619 METIS, Paris, France
| | - Josette Garnier
- Sorbonne Université, Université Pierre et Marie Curie, Centre National de la Recherche Scientifique, Institut Pierre Simon Laplace, UMR 7619 METIS, Paris, France
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23
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Wang X, He Y, Chen H, Yuan X, Peng C, Yue J, Zhang Q, Zhou L. CH 4 concentrations and fluxes in a subtropical metropolitan river network: Watershed urbanization impacts and environmental controls. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:1079-1089. [PMID: 29890577 DOI: 10.1016/j.scitotenv.2017.12.054] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 06/08/2023]
Abstract
Urbanization and greenhouse gas emissions are of great global concern, especially in developing countries such as China. However, little is known about the relationship between the two. In this study, we examined the influences of the urbanization of Chongqing Municipality, which covers an area of 5494km2, in China, on the CH4 emissions of in its metropolitan river network. The results from 84 sampling locations showed an overall mean CH4 concentration of 0.69±1.37μmol·L-1 and a CH4 flux from the river network of 1.40±2.53mmolCH4m-2d-1. The CH4 concentrations and fluxes presented a clear seasonal pattern, with the highest value in the spring and the lowest in the summer. Such seasonal variations were probably co-regulated by the dilution effect, temperature and supply of fresh organic matter by algal blooms. Another important result was that the CH4 concentrations and fluxes increased with the degree of urbanization or the proportion of urban land use, being approximately 3-13 times higher in urban and suburban areas than in rural ones. The total nitrogen, dissolved oxygen (O%) and possible sewage discharge, which could affect the in situ CH4 production and exogenous CH4 input respectively, were important factors that influenced the spatial patterns of CH4 in human-dominated river networks, while the nitrogen (N) and phosphorus (P) could be good predictors of the CH4 emissions in urban watersheds. Hydrologic drivers, including bottom sediment type, flow velocity and river width, were strongly correlated with the CH4 concentrations and could also affect the spatial variance and predict the CH4 hotspots in such metropolitan river networks. With increasing urbanization, we should pay more attention to the increasing greenhouse gas emissions associated with urbanization.
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Affiliation(s)
- Xiaofeng Wang
- College of Geography and Tourism, Chongqing Normal University, Chongqing 400047, China; Wetland Science Research Center of the Upper Reaches of the Yangtze River, Chongqing Normal University, Chongqing 400047, China
| | - Yixin He
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation, Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan 624400, China
| | - Huai Chen
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation, Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan 624400, China.
| | - Xingzhong Yuan
- College of Geography and Tourism, Chongqing Normal University, Chongqing 400047, China; Wetland Science Research Center of the Upper Reaches of the Yangtze River, Chongqing Normal University, Chongqing 400047, China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, China; College of Resources and Environmental Science, Chongqing University, Chongqing 400030, China
| | - Changhui Peng
- Institut des Sciences de l'Environnement, Université du Québec à Montréal (UQAM), 201 Président-Kennedy, Montréal H2X 3Y7, Canada; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, College of Forestry, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Junsheng Yue
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, China; College of Resources and Environmental Science, Chongqing University, Chongqing 400030, China
| | - Qiaoyong Zhang
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, China; College of Resources and Environmental Science, Chongqing University, Chongqing 400030, China
| | - Lilei Zhou
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400030, China; College of Resources and Environmental Science, Chongqing University, Chongqing 400030, China
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24
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Wu S, Chen J, Li C, Kong D, Yu K, Liu S, Zou J. Diel and seasonal nitrous oxide fluxes determined by floating chamber and gas transfer equation methods in agricultural irrigation watersheds in southeast China. ENVIRONMENTAL MONITORING AND ASSESSMENT 2018; 190:122. [PMID: 29417234 DOI: 10.1007/s10661-018-6502-0] [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: 10/24/2017] [Accepted: 01/22/2018] [Indexed: 06/08/2023]
Abstract
Agricultural nitrate leaching and runoff incurs high nitrogen loads in agricultural irrigation watersheds, constituting one of important sources of atmospheric nitrous oxide (N2O). Two independent sampling campaigns of N2O flux measurement over diel cycles and N2O flux measurements once a week over annual cycles were carried out in an agricultural irrigation watershed in southeast China using floating chamber (chamber-based) and gas transfer equation (model-based) methods. The diel and seasonal patterns of N2O fluxes did not differ between the two measurement methods. The diel variation in N2O fluxes was characterized by the pattern that N2O fluxes were greater during nighttime than daytime periods with a single flux peak at midnight. The diel variation in N2O fluxes was closely associated with water environment and chemistry. The time interval of 9:00-11:00 a.m. was identified to be the sampling time best representing daily N2O flux measurements in agricultural irrigation watersheds. Seasonal N2O fluxes showed large variation, with some flux peaks corresponding to agricultural irrigation and drainage episodes and heavy rainfall during the crop-growing period of May to November. On average, N2O fluxes calculated by model-based methods were 27% lower than those determined by the chamber-based techniques over diel or annual cycles. Overall, more measurement campaigns are highly needed to assess regional agricultural N2O budget with low uncertainties.
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Affiliation(s)
- Shuang Wu
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Jie Chen
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Chen Li
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Delei Kong
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Kai Yu
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shuwei Liu
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Jianwen Zou
- Jiangsu Key Laboratory of Low Carbon Agriculture and GHGs Mitigation, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
- Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China.
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25
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Hu B, Wang D, Zhou J, Meng W, Li C, Sun Z, Guo X, Wang Z. Greenhouse gases emission from the sewage draining rivers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 612:1454-1462. [PMID: 28903174 DOI: 10.1016/j.scitotenv.2017.08.055] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/03/2017] [Accepted: 08/06/2017] [Indexed: 06/07/2023]
Abstract
Carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) concentration, saturation and fluxes in rivers (Beitang drainage river, Dagu drainage rive, Duliujianhe river, Yongdingxinhe river and Nanyunhe river) of Tianjin city (Haihe watershed) were investigated during July and October in 2014, and January and April in 2015 by static headspace gas chromatography method and the two-layer model of diffusive gas exchange. The influence of environmental variables on greenhouse gases (GHGs) concentration under the disturbance of anthropogenic activities was discussed by Spearman correlative analysis and multiple stepwise regression analysis. The results showed that the concentration and fluxes of CO2, CH4 and N2O were seasonally variable with >winter>fall>summer, spring>summer>winter>fall and summer>spring>winter>fall for concentrations and spring>summer>fall>winter, spring>summer>winter>fall and summer>spring>fall>winter for fluxes respectively. The GHGs concentration and saturation were higher in comprehensively polluted river sites and lower in lightly polluted river sites. The three GHGs emission fluxes in two sewage draining rivers of Tianjin were clearly higher than those of other rivers (natural rivers) and the spatial variation of CH4 was more obvious than the others. CO2 and N2O air-water interface emission fluxes of the sewage draining rivers in four seasons were about 1.20-2.41 times and 1.13-3.12 times of those in the natural rivers. The CH4 emission fluxes of the sewage draining rivers were 3.09 times in fall to 10.87 times in spring of those in the natural rivers in different season. The wind speed, water temperature and air temperature were related to GHGs concentrations. Nitrate and nitrite (NO3-+NO2--N) and ammonia (NH4+-N) were positively correlated with CO2 concentration and CH4 concentration; and dissolved oxygen (DO) concentration was negatively correlated with CH4 concentration and N2O concentration. The effect of human activities on carbon and nitrogen cycling in river is great.
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Affiliation(s)
- Beibei Hu
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China; Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China
| | - Dongqi Wang
- Key Laboratory of Geographic Information Science (Ministry of Education), East China Normal University, Shanghai 200241, China; School of Geographic Sciences, East China Normal University, Shanghai 200241, China
| | - Jun Zhou
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China; Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China
| | - Weiqing Meng
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China; Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China.
| | - Chongwei Li
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China; Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China
| | - Zongbin Sun
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Xin Guo
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China
| | - Zhongliang Wang
- School of Geographic and Environmental Sciences, Tianjin Normal University, Tianjin 300387, China; Tianjin Key Laboratory of Water Resources and Environment, Tianjin Normal University, Tianjin 300387, China
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26
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Borges AV, Darchambeau F, Lambert T, Bouillon S, Morana C, Brouyère S, Hakoun V, Jurado A, Tseng HC, Descy JP, Roland FAE. Effects of agricultural land use on fluvial carbon dioxide, methane and nitrous oxide concentrations in a large European river, the Meuse (Belgium). THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 610-611:342-355. [PMID: 28806551 DOI: 10.1016/j.scitotenv.2017.08.047] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/04/2017] [Accepted: 08/05/2017] [Indexed: 06/07/2023]
Abstract
We report a data-set of CO2, CH4, and N2O concentrations in the surface waters of the Meuse river network in Belgium, obtained during four surveys covering 50 stations (summer 2013 and late winter 2013, 2014 and 2015), from yearly cycles in four rivers of variable size and catchment land cover, and from 111 groundwater samples. Surface waters of the Meuse river network were over-saturated in CO2, CH4, N2O with respect to atmospheric equilibrium, acting as sources of these greenhouse gases to the atmosphere, although the dissolved gases also showed marked seasonal and spatial variations. Seasonal variations were related to changes in freshwater discharge following the hydrological cycle, with highest concentrations of CO2, CH4, N2O during low water owing to a longer water residence time and lower currents (i.e. lower gas transfer velocities), both contributing to the accumulation of gases in the water column, combined with higher temperatures favourable to microbial processes. Inter-annual differences of discharge also led to differences in CH4 and N2O that were higher in years with prolonged low water periods. Spatial variations were mostly due to differences in land cover over the catchments, with systems dominated by agriculture (croplands and pastures) having higher CO2, CH4, N2O levels than forested systems. This seemed to be related to higher levels of dissolved and particulate organic matter, as well as dissolved inorganic nitrogen in agriculture dominated systems compared to forested ones. Groundwater had very low CH4 concentrations in the shallow and unconfined aquifers (mostly fractured limestones) of the Meuse basin, hence, should not contribute significantly to the high CH4 levels in surface riverine waters. Owing to high dissolved concentrations, groundwater could potentially transfer important quantities of CO2 and N2O to surface waters of the Meuse basin, although this hypothesis remains to be tested.
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Affiliation(s)
- A V Borges
- Chemical Oceanography Unit, University of Liège, Liège, Belgium.
| | - F Darchambeau
- Chemical Oceanography Unit, University of Liège, Liège, Belgium
| | - T Lambert
- Chemical Oceanography Unit, University of Liège, Liège, Belgium
| | - S Bouillon
- Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium
| | - C Morana
- Department of Earth and Environmental Sciences, KU Leuven, Leuven, Belgium
| | - S Brouyère
- Hydrogeology and Environmental Geology, University of Liège, Liège, Belgium
| | - V Hakoun
- Hydrogeology and Environmental Geology, University of Liège, Liège, Belgium
| | - A Jurado
- Hydrogeology and Environmental Geology, University of Liège, Liège, Belgium
| | - H-C Tseng
- Chemical Oceanography Unit, University of Liège, Liège, Belgium
| | - J-P Descy
- Chemical Oceanography Unit, University of Liège, Liège, Belgium
| | - F A E Roland
- Chemical Oceanography Unit, University of Liège, Liège, Belgium
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27
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Burgos M, Ortega T, Forja JM. Temporal and spatial variation of N 2O production from estuarine and marine shallow systems of Cadiz Bay (SW, Spain). THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 607-608:141-151. [PMID: 28688256 DOI: 10.1016/j.scitotenv.2017.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 06/20/2017] [Accepted: 07/03/2017] [Indexed: 06/07/2023]
Abstract
There is still much uncertainty regarding the global oceanic emissions of N2O, and particularly emissions from coastal regions, because spatio-temporal datasets have limited coverage. The concentration of dissolved N2O in surface waters and the associated fluxes to the atmosphere have been studied in three coastal systems located near Cadiz Bay (southwestern coast of Spain) over different time scales. The three systems present different hydrodynamic characteristics (an estuary and two marine systems) that influence the distribution of N2O in the water column. Nutrients, oxygen, and particulate organic nitrogen were also measured to investigate the processes responsible for N2O production in the water column. Data on dissolved N2O has been obtained in each system from i) two-year monitoring at fixed station; ii) four seasonal samplings along the longitudinal length of the system; and iii) daily sampling in summer. The concentration of N2O ranges between 1.1 and 292.0nM indicating very high spatio-temporal variability. In general, the concentration of N2O increased during the rainy season associated with the precipitation regime that, in turn, increases the lateral inputs of organic matter and nutrients from both natural sources (discharges into rivers and adjacent marshes) and anthropogenic activities (agriculture, urban effluents and fish farming). Dissolved N2O also varied with the tides: the highest concentrations were measured during the ebb, which suggests that the systems export N2O to the Bay and adjacent Atlantic Ocean. In addition nitrification seems to be an important process for N2O formation in the water column, which also explains some of the variability in the dataset. The mean atmospheric flux of N2O reveals that entire study area was a net source of N2O to the atmosphere. The fluxes ranged between 0.5 and 313.2μmolm-2day-1 in the estuarine system, and between -7.2 and 97.8μmolm-2day-1 in the two marine systems.
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Affiliation(s)
- Macarena Burgos
- Dpto. Química-Física, INMAR, Universidad de Cádiz, Campus Río San Pedro, s/n, Puerto Real, Cádiz, Spain.
| | - Teodora Ortega
- Dpto. Química-Física, INMAR, Universidad de Cádiz, Campus Río San Pedro, s/n, Puerto Real, Cádiz, Spain.
| | - Jesús M Forja
- Dpto. Química-Física, INMAR, Universidad de Cádiz, Campus Río San Pedro, s/n, Puerto Real, Cádiz, Spain.
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28
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Crawford JT, Stanley EH. Controls on methane concentrations and fluxes in streams draining human-dominated landscapes. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:1581-1591. [PMID: 27755752 DOI: 10.1890/15-1330] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/04/2015] [Accepted: 11/06/2015] [Indexed: 06/06/2023]
Abstract
Streams and rivers are active processors of carbon, leading to significant emissions of CO2 and possibly CH4 to the atmosphere. Patterns and controls of CH4 in fluvial ecosystems remain relatively poorly understood. Furthermore, little is known regarding how major human impacts to fluvial ecosystems may be transforming their role as CH4 producers and emitters. Here, we examine the consequences of two distinct ecosystem changes as a result of human land use: increased nutrient loading (primarily as nitrate), and increased sediment loading and deposition of fine particles in the benthic zone. We did not find support for the hypothesis that enhanced nitrate loading down-regulates methane production via thermodynamic or toxic effects. We did find strong evidence that increased sedimentation and enhanced organic matter content of the benthos lead to greater methane production (diffusive + ebullitive flux) relative to pristine fluvial systems in northern Wisconsin (upper Midwest, USA). Overall, streams in a human-dominated landscape of southern Wisconsin were major regional sources of CH4 to the atmosphere, equivalent to ~20% of dairy cattle emissions, or ~50% of a landfill's annual emissions. We suggest that restoration of the benthic environment (reduced fine deposits) could lead to reduced CH4 emissions, while decreasing nutrient loading is likely to have limited impacts to this ecosystem process.
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Affiliation(s)
- John T Crawford
- U.S. Geological Survey, National Research Program, 3215 Marine Street, Boulder, Colorado, 80303, USA
| | - Emily H Stanley
- Center for Limnology, University of Wisconsin-Madison, 680 North Park Street, Madison, Wisconsin, 53706, USA
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Stanley EH, Casson NJ, Christel ST, Crawford JT, Loken LC, Oliver SK. The ecology of methane in streams and rivers: patterns, controls, and global significance. ECOL MONOGR 2016. [DOI: 10.1890/15-1027] [Citation(s) in RCA: 255] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Emily H. Stanley
- Center for Limnology University of Wisconsin 680 North Park Street Madison Wisconsin 53706 USA
| | - Nora J. Casson
- Center for Limnology University of Wisconsin 680 North Park Street Madison Wisconsin 53706 USA
| | - Samuel T. Christel
- Center for Limnology University of Wisconsin 680 North Park Street Madison Wisconsin 53706 USA
| | - John T. Crawford
- U.S. Geological Survey 3215 Marine Street Suite E127 Boulder Colorado 80303 USA
| | - Luke C. Loken
- Center for Limnology University of Wisconsin 680 North Park Street Madison Wisconsin 53706 USA
| | - Samantha K. Oliver
- Center for Limnology University of Wisconsin 680 North Park Street Madison Wisconsin 53706 USA
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30
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Murray RH, Erler DV, Eyre BD. Nitrous oxide fluxes in estuarine environments: response to global change. GLOBAL CHANGE BIOLOGY 2015; 21:3219-3245. [PMID: 25752934 DOI: 10.1111/gcb.12923] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/02/2015] [Indexed: 06/04/2023]
Abstract
Nitrous oxide is a powerful, long-lived greenhouse gas, but we know little about the role of estuarine areas in the global N2 O budget. This review summarizes 56 studies of N2 O fluxes and associated biogeochemical controlling factors in estuarine open waters, salt marshes, mangroves, and intertidal sediments. The majority of in situ N2 O production occurs as a result of sediment denitrification, although the water column contributes N2 O through nitrification in suspended particles. The most important factors controlling N2 O fluxes seem to be dissolved inorganic nitrogen (DIN) and oxygen availability, which in turn are affected by tidal cycles, groundwater inputs, and macrophyte density. The heterogeneity of coastal environments leads to a high variability in observations, but on average estuarine open water, intertidal and vegetated environments are sites of a small positive N2 O flux to the atmosphere (range 0.15-0.91; median 0.31; Tg N2 O-N yr(-1) ). Global changes in macrophyte distribution and anthropogenic nitrogen loading are expected to increase N2 O emissions from estuaries. We estimate that a doubling of current median NO3 (-) concentrations would increase the global estuary water-air N2 O flux by about 0.45 Tg N2 O-N yr(-1) or about 190%. A loss of 50% of mangrove habitat, being converted to unvegetated intertidal area, would result in a net decrease in N2 O emissions of 0.002 Tg N2 O-N yr(-1) . In contrast, conversion of 50% of salt marsh to unvegetated area would result in a net increase of 0.001 Tg N2 O-N yr(-1) . Decreased oxygen concentrations may inhibit production of N2 O by nitrification; however, sediment denitrification and the associated ratio of N2 O:N2 is expected to increase.
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Affiliation(s)
- Rachel H Murray
- Centre for Coastal Biogeochemistry, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
| | - Dirk V Erler
- Centre for Coastal Biogeochemistry, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
| | - Bradley D Eyre
- Centre for Coastal Biogeochemistry, School of Environment, Science and Engineering, Southern Cross University, PO Box 157, Lismore, NSW, 2480, Australia
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31
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Burgos M, Sierra A, Ortega T, Forja JM. Anthropogenic effects on greenhouse gas (CH4 and N2O) emissions in the Guadalete River Estuary (SW Spain). THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 503-504:179-189. [PMID: 24993513 DOI: 10.1016/j.scitotenv.2014.06.038] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 06/02/2014] [Accepted: 06/10/2014] [Indexed: 06/03/2023]
Abstract
Coastal areas are subject to a great anthropogenic pressure because more than half of the world's population lives in its vicinity causing organic matter inputs, which intensifies greenhouse gas emissions into the atmosphere. Dissolved concentrations of CH4 and N2O have been measured seasonally during 2013 in the Guadalete River Estuary, which flows into the Cadiz Bay (southwestern Spanish coast). It has been intensely contaminated since 1970. Currently it receives wastewater effluents from cities and direct discharges from nearby agriculture crop. Eight sampling stations have been established along 18 km of the estuary. CH4 and N2O were measured using a gas chromatograph connected to an equilibration system. Additional parameters such as organic matter, dissolved oxygen, nutrients and chlorophyll were determinate as well, in order to understand the relationship between physicochemical and biological processes. Gas concentrations increased from the River mouth toward the inner part, closer to the wastewater treatment plant discharge. Values varied widely within 21.8 and 3483.4 nM for CH4 and between 9.7 and 147.6 nM for N2O. Greenhouse gas seasonal variations were large influenced by the precipitation regime, masking the temperature influence. The Guadatete Estuary acted as a greenhouse gas source along the year, with mean fluxes of 495.7 μmol m(-2)d(-1) and 92.8 μmol m(-2)d(-1) for CH4 and N2O, respectively.
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Affiliation(s)
- M Burgos
- Dpto. Química-Física, CACYTMAR, Universidad de Cádiz, Campus Río San Pedro, s/n, Puerto Real, Cádiz, Spain
| | - A Sierra
- Dpto. Química-Física, CACYTMAR, Universidad de Cádiz, Campus Río San Pedro, s/n, Puerto Real, Cádiz, Spain
| | - T Ortega
- Dpto. Química-Física, CACYTMAR, Universidad de Cádiz, Campus Río San Pedro, s/n, Puerto Real, Cádiz, Spain
| | - J M Forja
- Dpto. Química-Física, CACYTMAR, Universidad de Cádiz, Campus Río San Pedro, s/n, Puerto Real, Cádiz, Spain
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Panneer Selvam B, Natchimuthu S, Arunachalam L, Bastviken D. Methane and carbon dioxide emissions from inland waters in India - implications for large scale greenhouse gas balances. GLOBAL CHANGE BIOLOGY 2014; 20:3397-3407. [PMID: 24623552 DOI: 10.1111/gcb.12575] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 02/25/2014] [Indexed: 06/03/2023]
Abstract
Inland waters were recently recognized to be important sources of methane (CH4 ) and carbon dioxide (CO2 ) to the atmosphere, and including inland water emissions in large scale greenhouse gas (GHG) budgets may potentially offset the estimated carbon sink in many areas. However, the lack of GHG flux measurements and well-defined inland water areas for extrapolation, make the magnitude of the potential offset unclear. This study presents coordinated flux measurements of CH4 and CO2 in multiple lakes, ponds, rivers, open wells, reservoirs, springs, and canals in India. All these inland water types, representative of common aquatic ecosystems in India, emitted substantial amounts of CH4 and a major fraction also emitted CO2 . The total CH4 flux (including ebullition and diffusion) from all the 45 systems ranged from 0.01 to 52.1 mmol m(-2) d(-1) , with a mean of 7.8 ± 12.7 (mean ± 1 SD) mmol m(-2) d(-1) . The mean surface water CH4 concentration was 3.8 ± 14.5 μm (range 0.03-92.1 μm). The CO2 fluxes ranged from -28.2 to 262.4 mmol m(-2) d(-1) and the mean flux was 51.9 ± 71.1 mmol m(-2) d(-1) . The mean partial pressure of CO2 was 2927 ± 3269 μatm (range: 400-11 467 μatm). Conservative extrapolation to whole India, considering the specific area of the different water types studied, yielded average emissions of 2.1 Tg CH4 yr(-1) and 22.0 Tg CO2 yr(-1) from India's inland waters. When expressed as CO2 equivalents, this amounts to 75 Tg CO2 equivalents yr(-1) (53-98 Tg CO2 equivalents yr(-1) ; ± 1 SD), with CH4 contributing 71%. Hence, average inland water GHG emissions, which were not previously considered, correspond to 42% (30-55%) of the estimated land carbon sink of India. Thereby this study illustrates the importance of considering inland water GHG exchange in large scale assessments.
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33
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Narvenkar G, Naqvi SWA, Kurian S, Shenoy DM, Pratihary AK, Naik H, Patil S, Sarkar A, Gauns M. Dissolved methane in Indian freshwater reservoirs. ENVIRONMENTAL MONITORING AND ASSESSMENT 2013; 185:6989-6999. [PMID: 23397538 DOI: 10.1007/s10661-013-3079-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 01/03/2013] [Indexed: 06/01/2023]
Abstract
Emission of methane (CH4), a potent greenhouse gas, from tropical reservoirs is of interest because such reservoirs experience conducive conditions for CH4 production through anaerobic microbial activities. It has been suggested that Indian reservoirs have the potential to emit as much as 33.5 MT of CH4 per annum to the atmosphere. However, this estimate is based on assumptions rather than actual measurements. We present here the first data on dissolved CH4 concentrations from eight freshwater reservoirs in India, most of which experience seasonal anaerobic conditions and CH4 buildup in the hypolimnia. However, strong stratification prevents the CH4-rich subsurface layers to ventilate CH4 directly to the atmosphere, and surface water CH4 concentrations in these reservoirs are generally quite low (0.0028-0.305 μM). Moreover, only in two small reservoirs substantial CH4 accumulation occurred at depths shallower than the level where water is used for power generation and irrigation, and in the only case where measurements were made in the outflowing water, CH4 concentrations were quite low. In conjunction with short periods of CH4 accumulation and generally lower concentrations than previously assumed, our study implies that CH4 emission from Indian reservoirs has been greatly overestimated.
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Affiliation(s)
- G Narvenkar
- National Institute of Oceanography (Council of Scientific & Industrial Research), Dona Paula, Goa, 403004, India.
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Jayakumar R, Steger K, Chandra TS, Seshadri S. An assessment of temporal variations in physicochemical and microbiological properties of barmouths and lagoons in Chennai (Southeast coast of India). MARINE POLLUTION BULLETIN 2013; 70:44-53. [PMID: 23507232 DOI: 10.1016/j.marpolbul.2013.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Revised: 01/31/2013] [Accepted: 02/02/2013] [Indexed: 06/01/2023]
Abstract
Two estuary and two coastal lagoon stations along Chennai, Southeast coast of India were monitored for 1year to study both physicochemical and microbiological properties of the water. Influence of the marine environment over the systems was evident by elevated salinity levels. Considerable concentrations of total heterotrophic bacterial count and fecal bacteria such as total coliforms, fecal coliforms and fecal streptococci were observed throughout the study period which evinced a pattern of anthropogenic activities. Principle component analysis was employed for assessing the overall pattern of variation within the data sets. Climatic variation was highly correlated with changes in water quality, i.e. the Northeast monsoon and Summer had influenced considerably the microbial occurrence as well as the physicochemical parameters such as total suspended solids, chloride, sulphate and salinity. However, the effect of the Southwest monsoon was less prominent than the Northeast monsoon with its heavy rains. As both estuaries revealed elevated concentrations of polluted water, these stations can be used as indicators or alerts for the water quality along the coastal zone of Chennai.
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von Glasow R, Jickells TD, Baklanov A, Carmichael GR, Church TM, Gallardo L, Hughes C, Kanakidou M, Liss PS, Mee L, Raine R, Ramachandran P, Ramesh R, Sundseth K, Tsunogai U, Uematsu M, Zhu T. Megacities and large urban agglomerations in the coastal zone: interactions between atmosphere, land, and marine ecosystems. AMBIO 2013; 42:13-28. [PMID: 23076973 PMCID: PMC3547459 DOI: 10.1007/s13280-012-0343-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 06/29/2012] [Accepted: 08/16/2012] [Indexed: 05/25/2023]
Abstract
Megacities are not only important drivers for socio-economic development but also sources of environmental challenges. Many megacities and large urban agglomerations are located in the coastal zone where land, atmosphere, and ocean meet, posing multiple environmental challenges which we consider here. The atmospheric flow around megacities is complicated by urban heat island effects and topographic flows and sea breezes and influences air pollution and human health. The outflow of polluted air over the ocean perturbs biogeochemical processes. Contaminant inputs can damage downstream coastal zone ecosystem function and resources including fisheries, induce harmful algal blooms and feedback to the atmosphere via marine emissions. The scale of influence of megacities in the coastal zone is hundreds to thousands of kilometers in the atmosphere and tens to hundreds of kilometers in the ocean. We list research needs to further our understanding of coastal megacities with the ultimate aim to improve their environmental management.
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Affiliation(s)
- Roland von Glasow
- />School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK
| | - Tim D. Jickells
- />School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK
| | | | - Gregory R. Carmichael
- />Department of Chemical & Biochemical Engineering, The University of Iowa, Iowa City, IA 52242 USA
| | - Tom M. Church
- />School of Marine Science and Policy, University of Delaware, Newark, DE 19716-3501 USA
| | - Laura Gallardo
- />Departamento de Geofísica & Centro de Modelamiento Matemático, Universidad de Chile, Blanco Encalada 2002, Piso 4, Santiago, Chile
| | - Claire Hughes
- />Environment Department, University of York, Heslington, York, YO10 5DD UK
| | - Maria Kanakidou
- />Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, P.O. Box 2208, 71003 Heraklion, Greece
| | - Peter S. Liss
- />School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ UK
| | - Laurence Mee
- />Scottish Marine Institute, Scottish Association for Marine Science (SAMS), Oban, Argyll, PA37 1QA UK
| | - Robin Raine
- />The Ryan Institute for Environmental, Marine and Energy Research, National University of Ireland, Galway, Ireland
| | | | - R. Ramesh
- />Institute for Ocean Management, Anna University, Chennai, 600 025 India
| | - Kyrre Sundseth
- />Center for Ecology and Economics (CEE), NILU-Norwegian Institute for Air Research, Instituttveien 18, P.O. Box 100, 2007 Kjeller, Norway
| | - Urumu Tsunogai
- />Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 Japan
| | - Mitsuo Uematsu
- />Center for International Collaboration, Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8564 Japan
| | - Tong Zhu
- />State Key Laboratory for Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871 China
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Wu J, Chen N, Hong H, Lu T, Wang L, Chen Z. Direct measurement of dissolved N₂ and denitrification along a subtropical river-estuary gradient, China. MARINE POLLUTION BULLETIN 2013; 66:125-134. [PMID: 23168233 DOI: 10.1016/j.marpolbul.2012.10.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 10/21/2012] [Accepted: 10/24/2012] [Indexed: 06/01/2023]
Abstract
The spatial pattern and seasonal variation of denitrification were investigated during 2010-2011 in the Jiulong River Estuary (JRE) in southeast China. Dissolved N₂ was directly measured by changes in the N₂:Ar ratio. The results showed that excess dissolved N₂ ranged from -9.9 to 76.4 μmol L⁻¹. Tidal mixing leads to a seaward decline of dissolved gaseous concentrations and water-air fluxes along the river-estuary gradient. Denitrification at freshwater sites varied between seasons, associated with changes in N input and water temperature. The denitrification process was controlled by the nitrate level at freshwater sites, and the excess dissolved N₂ observed at the tidal zone largely originated from upstream water transport. Compared to other estuaries, JRE has a relative low gaseous removal efficiency (E(d)=12% of [DIN]; annual N removal=24% of DIN load), a fact ascribed to strong tidal mixing, coarse-textured sediment with shallow depth before bedrock and high riverine DIN input.
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Affiliation(s)
- Jiezhong Wu
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, PR China
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37
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Gonçalves WFO, Luiz-Silva W, Machado W, Nizoli EC, Santelli RE. Geochemistry of intertidal sediment pore waters from the industrialized Santos-Cubatão Estuarine System, SE Brazil. AN ACAD BRAS CIENC 2012; 84:427-42. [PMID: 22499259 DOI: 10.1590/s0001-37652012005000021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Accepted: 11/30/2011] [Indexed: 11/21/2022] Open
Abstract
The geochemical composition of sediment pore water was investigated in comparison with the composition of sediment particles and surface water in an estuary within one of the most industrialized areas in Latin America (Santos-Cubatão estuarine system, SE Brazil). Pore and surface waters presented anomalously high levels of F(-), NH4(+), Fe, Mn and P due to two industrial point sources. In the summer, when SO(4)(2-)/Cl(-) ratios suggested an enhanced sulfate reduction, the higher dissolved levels observed in pore waters for some metals (e.g., Cu and Ni) were attributed to reductive dissolution of oxidized phases. Results evidenced that the risks of surface water concentration increase due to diffusion or advection from pore water are probably dependent on coupled influences of tidal pumping and groundwater inputs.
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Affiliation(s)
- Winston F O Gonçalves
- Instituto de Geociências, Departamento de Geologia e Recursos Naturais, Universidade Estadual de Campinas, SP, Brasil
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38
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Barnes J, Upstill-Goddard RC. N2O seasonal distributions and air-sea exchange in UK estuaries: Implications for the tropospheric N2O source from European coastal waters. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2009jg001156] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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39
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Rosamond MS, Thuss SJ, Schiff SL, Elgood RJ. Coupled cycles of dissolved oxygen and nitrous oxide in rivers along a trophic gradient in southern Ontario, Canada. JOURNAL OF ENVIRONMENTAL QUALITY 2011; 40:256-270. [PMID: 21488515 DOI: 10.2134/jeq2010.0009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Diel (24-h) cycling of dissolved O2 (DO) in rivers is well documented, but evidence for coupled diel changes in DO and nitrogen cycling has only been demonstrated in hypereutrophic systems where DO approaches zero at night. Here, we show diel changes in N2O and DO concentration at several sites across a trophic gradient. Nitrous oxide concentration increased at night at all but one site in spring and summer, even when gas exchange was rapid and minimum water column DO was well above hypoxic conditions. Diel N2O curves were not mirror images of DO curves and were not symmetrical about the mean. Although inter- and intrasite variation was high, N2O peaked around the time of lowest DO at most of the sites. These results suggest that N2O must be measured several times per diel period to characterize curve shape and timing. Nitrous oxide concentration was not significantly correlated with NO3- concentration, contrary to studies in agricultural streams and to the current United Nations Intergovernmental Panel for Climate Change protocols for N2O emission estimation. The strong negative correlation between N2O concentration and daily minimum DO concentration suggested that N2O production was limited by DO. This is consistent with N2O produced by nitrite reduction. The ubiquity of diel N2O cycling suggests that most DO and N2O sampling strategies used in rivers are insufficient to capture natural variability. Ecosystem-level effects of microbial processes, such as denitrification, are sensitive to small changes in redox conditions in the water column even in low-nutrient oxic rivers, suggesting diel cycling of redox-sensitive compounds may exist in many aquatic systems.
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Affiliation(s)
- Madeline S Rosamond
- Dep. of Earth and Environmental Sciences, Univ. of Waterloo, 200 University Ave. W, Waterloo, ON Canada, N2L 3G1.
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40
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Riya S, Zhou S, Nakashimada Y, Terada A, Hosomi M. Direct and Indirect Greenhouse Gas Emissions from Vertical Flow Constructed Wetland Planted with Forage Rice. KAGAKU KOGAKU RONBUN 2010. [DOI: 10.1252/kakoronbunshu.36.229] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Shohei Riya
- Graduate School of Engineering, Tokyo University of Agriculture and Technology
| | - Sheng Zhou
- Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology
| | | | - Akihiko Terada
- Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology
| | - Masaaki Hosomi
- Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology
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