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Cui B, Xian C, Han B, Shu C, Qian Y, Ouyang Z, Wang X. High-resolution emission inventory of biogenic volatile organic compounds for rapidly urbanizing areas: A case of Shenzhen megacity, China. J Environ Manage 2024; 351:119754. [PMID: 38071916 DOI: 10.1016/j.jenvman.2023.119754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 11/24/2023] [Accepted: 11/30/2023] [Indexed: 01/14/2024]
Abstract
The effects of volatile organic compounds on urban air quality and the ozone have been widely acknowledged, and the contributions of relevant biogenic sources are currently receiving rising attentions. However, inventories of biogenic volatile organic compounds (BVOCs) are in fact limited for the environmental management of megacities. In this study, we provided an estimation of BVOC emissions and their spatial characteristics in a typical urbanized area, Shenzhen megacity, China, based on an in-depth vegetation investigation and using remote sensing data. The total BVOC emission in Shenzhen in 2019 was estimated to be 3.84 × 109 g C, of which isoprene contributed to about 24.4%, monoterpenes about 44.4%, sesquiterpenes about 1.9%, and other VOCs (OVOCs) about 29.3%. Metropolitan BVOC emissions exhibited a seasonal pattern with a peak in July and a decline in January. They were mainly derived from the less built-up areas (88.9% of BVOC emissions). Estimated BVOCs comprised around 5.2% of the total municipal VOC emissions in 2019. This percentage may increase as more green spaces emerge and anthropogenic emissions decrease in built-up areas. Furthermore, synergistic effects existed between BVOC emissions and relevant vegetation-based ecosystem services (e.g., air purification, carbon fixation). Greening during urban sprawl should be based on a trade-off between BVOC emissions and ecosystem benefits of urban green spaces. The results suggested that urban greening in Shenzhen, and like other cities as well, need to account for BVOC contributions to ozone. Meanwhile, greening cites should adopt proactive environmental management by using plant species with low BVOC emissions to maintain urban ecosystem services while avoid further degradation to ozone pollution.
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Affiliation(s)
- Bowen Cui
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chaofan Xian
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; Beijing-Tianjin-Hebei Urban Megaregion National Observation and Research Station for Eco-Environmental Change, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Baolong Han
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Chengji Shu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuguo Qian
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Zhiyun Ouyang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiaoke Wang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Beijing-Tianjin-Hebei Urban Megaregion National Observation and Research Station for Eco-Environmental Change, Chinese Academy of Sciences, Beijing, 100085, China
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Liu Y, Lu F, Xian C, Ouyang Z. Urban development and resource endowments shape natural resource utilization efficiency in Chinese cities. J Environ Sci (China) 2023; 126:806-816. [PMID: 36503805 DOI: 10.1016/j.jes.2022.03.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 06/17/2023]
Abstract
Improving the efficiency with which natural resources are utilized is an indispensable for achieving sustainable development and carbon neutrality. By analyzing the utilization efficiency of energy, water, and land, we established a comprehensive natural resource utilization efficiency index (NRUEI). We then calculated the 2016 index for 165 cities in China, and investigated what caused it to vary. We found three main results: (1) the NRUEI varied greatly across China and there were significant positive correlations between urban energy utilization efficiency (EUE), water utilization efficiency (WUE) and land utilization efficiency (LUE); (2) the NRUEI showed a significant positive correlation with a city's population size, economy (Gross Domestic Product (GDP)), and the level of urban social development (GDP per capita); (3) cities in East China have the highest natural resource utilization efficiency, while cities in Northeast China have the lowest. These results indicate that China's increasing urban development is associated with rising natural resource utilization efficiency and that the city's endowment of natural resources is an important factor affecting that efficiency. Further, the results showed that the determinants of a city's NRUEI differed in large and small cities. Lastly, our results suggest that improving EUE is key for improving NRUEI in urban China, and different efficiencies can be improved intertwined. A major takeaway of this study is that there is great potential for improving natural resource utilization efficiency in Chinese cities and we include city-specific suggestions for efficiency improvements.
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Affiliation(s)
- Yanbing Liu
- State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fei Lu
- State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Chaofan Xian
- State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Zhiyun Ouyang
- State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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Xian C, Gong C, Lu F, Wu H, Ouyang Z. The evaluation of greenhouse gas emissions from sewage treatment with urbanization: Understanding the opportunities and challenges for climate change mitigation in China's low-carbon pilot city, Shenzhen. Sci Total Environ 2023; 855:158629. [PMID: 36087675 DOI: 10.1016/j.scitotenv.2022.158629] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 09/04/2022] [Accepted: 09/05/2022] [Indexed: 06/15/2023]
Abstract
Sewage treatment provides a pathway for anthropogenic water purification that can address the growth in domestic sewage volumes due to urbanization and protect the aquatic environment. However, the process can also generate greenhouse gases (GHGs), which are sometimes termed "unrestricted" GHG emissions and are neglected by low carbon policies. A combination of a life cycle analysis (LCA), data envelopment analysis (DEA), and questionnaire survey was used to evaluate sewage treatment related GHG emissions and assess the GHG emission reduction efficiencies during 2005-2020, as well as determine the opinions of environmental managers regarding the threats to climate change mitigation posed by sewage treatment in the low carbon pilot city of Shenzhen, China. There were four main results. (1) GHG emissions from sewage treatment plants (STPs) in Shenzhen increased gradually from 0.22 Mt. CO2-eq in 2005 to 1.16 Mt. CO2-eq in 2020 with an emission intensity ranging from 0.41 to 0.58 kg CO2-eq/m3, mainly due to the indirect emissions from sludge disposal (35-57 %). Longgang administrative district was the hotspot of these GHG emissions during the study period. (2) Reductions in GHG emissions were achieved in most years since 2012 with the greatest efficiency observed in 2020. (3) Beyond the environmental managers' perceptions of the challenges in GHG mitigation, future sewage treatment may create the potential for more substantial GHG emission growth compared to the emissions from energy combustion, due to policy deficiencies, growth in sewage volumes, and the enforcement of stricter effluent quality control. (4) Several opportunities to overcome these barriers were considered including innovational environmental management, planting of constructed wetlands, and the promotion of water-saving behavior. This case study of Shenzhen has valuable implications for the synergistic governance of water pollution and climate change mitigation in megacities in China and elsewhere, enabling a move towards a future carbon-neutral society.
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Affiliation(s)
- Chaofan Xian
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Cheng Gong
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Fei Lu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Haotong Wu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Zhiyun Ouyang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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Xie S, Marzluff JM, Su Y, Wang Y, Meng N, Wu T, Gong C, Lu F, Xian C, Zhang Y, Ouyang Z. The role of urban waterbodies in maintaining bird species diversity within built area of Beijing. Sci Total Environ 2022; 806:150430. [PMID: 34852427 DOI: 10.1016/j.scitotenv.2021.150430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 08/02/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
This study aims to provide a comprehensive understanding of the role of urban waterbodies in avian ecology, which is instructive for both biodiversity conservation and urban planning. Based on bird surveys conducted in 41 urban parks in Beijing during the breeding and wintering seasons of 2018-2019, and using standardized regression analyses, we identified the specific effects of waterbody attributes on the full avian community and forest bird guilds. We assessed this at multiple spatial scales, first within the focal parks, and then within buffer zones with radius of 200 m and 1000 m. We found that waterbodies can serve as avian diversity "hotspots" in the urban landscape. More specifically, they support avian diversity in the following ways: (1) Parks with waterbodies maintain a higher number of bird species than parks without waterbodies during the breeding season and attract resident forest birds during the wintering season. (2) When not frozen, waterbodies inside and outside parks contribute equally to resident forest bird species richness, while more individuals were attracted by waterbodies within neighborhoods. (3) In parks without waterbodies, the number of forest bird species significantly increases with the number of waterbody patches within neighborhoods, while the corresponding relationship for parks with waterbodies is insignificant. These findings suggest a preference for habitats nearby waterbodies among forest birds residing highly urbanized areas. This study provides new insights into avian ecology in urban landscapes and scientific support for the idea that creating and maintaining urban waterbodies can conserve biodiversity.
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Affiliation(s)
- Shilin Xie
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - John M Marzluff
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA 98195, USA
| | - Yuebo Su
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yaqing Wang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Nan Meng
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tong Wu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cheng Gong
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Life Science, University of Science and Technology of China, Hefei 230026, China
| | - Fei Lu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; Beijing Urban Ecosystem Research Station, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Chaofan Xian
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yan Zhang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiyun Ouyang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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5
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Gong C, Xian C, Cui B, He G, Wei M, Zhang Z, Ouyang Z. Estimating NO x removal capacity of urban trees using stable isotope method: A case study of Beijing, China. Environ Pollut 2021; 290:118004. [PMID: 34454196 DOI: 10.1016/j.envpol.2021.118004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/22/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
It is widely recognized that green infrastructures in urban ecosystems provides important ecosystem services, including air purification. The potential absorption of nitrogen oxides (NOx) by urban trees has not been fully quantified, although it is important for air pollution mitigation and the well-being of urban residents. In this study, four common tree species (Sophora japonica L., Fraxinus chinensis Roxb., Populus tomentosa Carrière, Sabina chinensis (L.)) in Beijing, China, were studied. The dual stable isotopes (15N and 18O) and a Bayesian isotope mixing model were applied to estimate the sources contributions of potential nitrogen sources to the roadside trees based on leaf and soil sampling in urban regions. The following order of sources contributions was determined: soil > dry deposition > traffic-related NOx. The capacity of urban trees for NOx removal in the city was estimated using a remote sensing and GIS approach, and the removal capacity was found to range from 0.79 to 1.11 g m-2 a-1 across administrative regions, indicating that 1304 tons of NOx could be potentially removed by urban trees in 2019. Our finding qualified the potential NOx removal by urban trees in terms of atmospheric pollution mitigation, highlighting the role of green infrastructure in air purification, which should be taken into account by stakeholders to manage green infrastructure as the basis of a nature-based approach.
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Affiliation(s)
- Cheng Gong
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Chaofan Xian
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Bowen Cui
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Guojin He
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, China.
| | - Mingyue Wei
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, China.
| | - Zhaoming Zhang
- Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100094, China.
| | - Zhiyun Ouyang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
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Gong C, Xian C, Su Y, Ouyang Z. Estimating the nitrogen source apportionment of Sophora japonica in roadside green spaces using stable isotope. Sci Total Environ 2019; 689:1348-1357. [PMID: 31466171 DOI: 10.1016/j.scitotenv.2019.06.408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/24/2019] [Accepted: 06/24/2019] [Indexed: 06/10/2023]
Abstract
It is generally accepted that urban vegetation absorbs air pollutants resulting in improved air quality. However, limited work has provided experimental data that can be used to quantify this. In this study, Sophora japonica in the near-road environment was studied, and stable isotopes were used to estimate the proportional contributions of different nitrogen sources to the trees. δ15N and δ18O values were quantified for plant (n = 254) and soil samples (n = 86) collected from 12 sampling sites in Beijing. The elemental composition (total nitrogen (TN) and total carbon (TC)) of both samples types, and the ionic concentration (NO3- and NH4+) of soil samples were also measured. δ15N in S. japonica sampled near the road was significantly lower than in samples collected far from the road. Variation of δ18O, TN, and TC in plant samples could not be explained by the road distance. Using the SIAR Bayesian isotope mixing model and the mixing polygon method, the average proportional contributions of three nitrogen sources for the tree samples among all experiment sites were estimated, with the proportion for each nitrogen source following the order: soil (69.2%) > traffic-related NOx (19.3%) > dry deposition (11.5%). In addition, the results of the Bayesian model revealed that the nitrogen contribution of traffic-related NOx at road-adjacent sites (23.0%) was higher than the contribution of traffic-related NOx at sites far from the road (16.4%). These results indicated that the S. japonica in near-road green spaces was significantly influenced by traffic-related NOx emissions that were characterized by lower δ15N values. We found that using the SIAR Bayesian isotope mixing model and mixing polygon method, the potential nitrogen sources of plants could be estimated and the proportional contributions estimated by the model can reflect the plant's ability to absorb air-borne NOx.
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Affiliation(s)
- Cheng Gong
- School of Life Science, University of Science and Technology of China, Anhui 230026, China.
| | - Chaofan Xian
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Yuebo Su
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Zhiyun Ouyang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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Xian C, Zhang X, Zhang J, Fan Y, Zheng H, Salzman J, Ouyang Z. Recent patterns of anthropogenic reactive nitrogen emissions with urbanization in China: Dynamics, major problems, and potential solutions. Sci Total Environ 2019; 656:1071-1081. [PMID: 30625639 DOI: 10.1016/j.scitotenv.2018.11.352] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/22/2018] [Accepted: 11/24/2018] [Indexed: 05/22/2023]
Abstract
Anthropogenic emissions of reactive nitrogen (Nr) result in adverse impacts on the ecosystems. Nowhere has that threat been more challenging than in rapidly urbanized China, the world's largest anthropogenic Nr producer. The Nanjing Declaration in 2004 called for global reductions in Nr emissions. To assess China's progress, multisource Nr emissions were evaluated with a quantitative method from 2004 to 2014. The results showed that national Nr emissions had increased with fluctuation over this period, 55-59% of the total Nr emissions were emitted to the atmosphere, and that agricultural production still was the biggest contributor (62-69%). The hotspots were mainly located in the developed and coastal regions that also have high population densities. Urbanization was associated with overall decreases in agricultural Nr emission and increases in industrial and residential Nr emissions. The overall increase in residential Nr emission per capita played a large role in driving the growth of national Nr emission. Continuing urbanization poses a significant challenge to future Nr mitigation for ecosystem sustainability and a range of strategies, covering improvement of N-use efficiency, slowdown of Western China's urbanization, and promotion of low N intensive lifestyle, are proposed that can promote Chinese low-nitrogen development.
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Affiliation(s)
- Chaofan Xian
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Xiaoling Zhang
- Department of Public Policy, City University of Hong Kong, Hong Kong 999077, China
| | - Jingjing Zhang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Yupeng Fan
- Key Laboratory of Eco-Industry of the Ministry of Environmental Protection, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Hua Zheng
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - James Salzman
- Bren School of Environmental Science & Management, University of California, Santa Barbara 93106-5131, USA
| | - Zhiyun Ouyang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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Xian C, Ouyang Z, Li Y, Xiao Y, Ren Y. Variation in nitrate isotopic signatures in sewage for source apportionment with urbanization: a case study in Beijing, China. Environ Sci Pollut Res Int 2016; 23:22871-22881. [PMID: 27572691 DOI: 10.1007/s11356-016-7498-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 08/22/2016] [Indexed: 05/22/2023]
Abstract
Nitrate (NO3-) pollution is a severe problem in urban aquatic systems especially within megacity undergoing rapid urbanization, and mostly, sewage is supposed as the prevailing NO3- source. A dual isotope approach (δ 15N-NO3- and δ 18O-NO3-) was applied to explore the variation in NO3- isotopic signatures in sewage processed by wastewater treatment plants (WWTPs) in Beijing from 2014 to 2015. We found that the raw and treated sewage owned the different NO3- isotopic signatures, including δ 15N from 1.1 to 24.7 ‰ and δ 18O from 1.6 to 22.8 ‰ in raw sewage, as well as δ 15N from 6.1 to 22.8 ‰ and δ 18O from 1.6 to 13.2 ‰ in treated effluents. The WWTP processing would result in the enrichment of NO3- isotopic compositions in discharged effluents with NO3- concentrations increasing. Besides, advanced sewage treatment technology with more pollutant N reduction may raise the heavier NO3- isotopic compositions further. The NO3- isotope value ranges of urban sewage and manure should be separated, and the seasonal and tighter NO3- isotope value ranges are supposed to improve the accuracy of source apportionment. The NO3- isotope value ranges conducted in this study might provide useful information for tracing NO3- sources towards the implementation of efficient water pollution control in Beijing.
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Affiliation(s)
- Chaofan Xian
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhiyun Ouyang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Yanmin Li
- School of Geographical Sciences, Southwest University, Chongqing, 400715, China
| | - Yang Xiao
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yufen Ren
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
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Xian C, Ouyang Z, Lu F, Xiao Y, Li Y. Quantitative evaluation of reactive nitrogen emissions with urbanization: a case study in Beijing megacity, China. Environ Sci Pollut Res Int 2016; 23:17689-17701. [PMID: 27240830 DOI: 10.1007/s11356-016-6961-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 05/23/2016] [Indexed: 06/05/2023]
Abstract
The rapid increase in anthropogenic nitrogen (N) load in urbanized environment threatens urban sustainability. In this study, we estimated the amount of reactive N (Nr) as an index of N pollution potential caused by human activities, using the megacity of Beijing as a case study. We investigated the temporal changes in Nr emissions in the environment from 2000 to 2012 using a multidisciplinary approach with quantitative evaluation. The Nr emissions presented slightly increasing during study period, and the annual emission was 0.19 Tg N, mainly resulting from fuel combustion. Nevertheless, the Nr output intensity resulting from inhabitants' livelihoods and material production had weakened over the study period. The evaluation results showed that the environmental measures to remove Nr in Beijing were efficient in most years, suggesting that progress in mitigating the growth of the Nr load in this urban environment was significant. Further measures based on N offset are suggested that could help alleviate the environmental pressure resulting from anthropogenic Nr emissions. These could provide theoretical support for the sustainable development of megacities.
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Affiliation(s)
- Chaofan Xian
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhiyun Ouyang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Fei Lu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yang Xiao
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yanmin Li
- School of Geographical Sciences, Southwest University, Chongqing, 400715, China
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Chen M, Chen Y, Bao Y, Xian C, Liu G, Zhang L, Xu G, Deng X, Lu T, Oian J, Cui N. Neoadjuvant chemotherapy followed by late-course accelerated hyperfractionated radiation therapy for locally advanced non-small cell lung cancer: The long term results of a phase I/II clinical trial. Int J Radiat Oncol Biol Phys 2004. [DOI: 10.1016/j.ijrobp.2004.07.485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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11
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Ferguson IA, Xian C, Barati E, Rush RA. Comparison of wheat germ agglutinin-horseradish peroxidase and biotinylated dextran for anterograde tracing of corticospinal tract following spinal cord injury. J Neurosci Methods 2001; 109:81-9. [PMID: 11513942 DOI: 10.1016/s0165-0270(01)00380-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Established methods for monitoring regeneration of the corticospinal tract involve anterograde labelling of the cortical motor neuron. While wheat germ agglutinin-horseradish peroxidase conjugate has been used to anterogradely label these neurons, we demonstrate that this technique may not completely label the whole axon and fine terminal processes when this tracer is administered in dried form. An alternative method is described for anterograde labelling of cortical motor neurons using biotinylated dextran. This tracer may be applied by either microinjection of 10% biotinylated dextran or implanting small globules of the dried tracer into the motor cortex. While more laborious, microinjection results in better anterograde labelling than implantation of dried biotinylated dextran. A procedure is also described for preparing serial coronal sections through the entire spinal cord and thaw-mounted on a minimum number of slides. The labelled nerve processes in these tissue sections can be visualised in the spinal cord under a fluorescent microscope following incubation with cy3-streptavidin complex. Permanent labelling of the biotinylated nerve processes is achieved by incubation of tissue sections with streptavidin-horseradish peroxidase conjugate followed by stringent washes and staining with tetramethylbenzidine. Use of tetramethylbenzidine allows resolution of a greater number of finer labelled processes than diaminobenzindine and allows clear visualisation of individual regenerating corticospinal tract processes. Using these procedures, we demonstrate that the corticospinal tract is completely lesioned by a standardised contusion spinal cord injury produced by the New York University weight-drop device.
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Affiliation(s)
- I A Ferguson
- Department of Human Physiology and Centre for Neuroscience, Flinders University School of Medicine, GPO Box 2100, SA 5001, Adelaide, Australia.
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Li WP, Xian C, Rush RA, Zhou XF. Upregulation of brain-derived neurotrophic factor and neuropeptide Y in the dorsal ascending sensory pathway following sciatic nerve injury in rat. Neurosci Lett 1999; 260:49-52. [PMID: 10027697 DOI: 10.1016/s0304-3940(98)00958-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
An immunohistochemical study was undertaken to examine the changes of brain-derived neurotrophic factor (BDNF) and neuropeptide Y (NPY) in the nucleus gracilis of rats following sciatic nerve transection. The results showed that BDNF-immunoreactivity (-ir) in the gracile nucleus was significantly increased after the nerve injury. The upregulation was apparent 24 h after nerve lesion, remaining robust up to 56 days postlesion. The increase in BDNF-ir was blocked by hemisection of the spinal cord, or by dorsal rhizotomy ipsilateral to the lesion. NPY-ir changes were similar to those of BDNF-ir, but the onset was delayed by 7 days. No NPY-ir was detected in dorsal root ganglion (DRG) from normal animals. Following sciatic nerve lesion, most of the NPY-immunoreactive neurones were found to be colocalized with BDNF-immunoreactive neurones. Neutralization of endogenous BDNF with its antiserum had no effects on NPY-ir in either the gracile nucleus or DRG. These results indicate that neurones contributing to the dorsal ascending sensory pathway upregulate the expression of both BDNF and NPY in response to sciatic nerve injury.
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Affiliation(s)
- W P Li
- Department of Human Physiology and Centre for Neuroscience, Flinders University of South Australia, Adelaide, Australia
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