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Lyu L, Fang K, Jin H, Yang GP, Liang H, Ding H. Distribution characteristics of low molecular weight organic acids in seawater of the Changjiang Estuary and its adjacent East China Sea: Implications for regional environmental conditions. MARINE POLLUTION BULLETIN 2020; 161:111741. [PMID: 33217637 DOI: 10.1016/j.marpolbul.2020.111741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 09/30/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
In this study, components, concentrations, distribution characteristics and sources of low molecular weight organic acids (LMWOAs) in seawater of the Changjiang Estuary and its adjacent East China Sea were investigated in March 2015. Lactic, acetic and formic acids were identified with their concentration range of 0-16.7, 0-42.7 and 0-6.7 μmol·L-1, respectively. In the surface seawater, high concentrations of LMWOAs appeared in the sea area close to the estuary and along the coast. LMWOAs were important fractions of dissolved organic carbon and acetic acid was dominant component of LMWOAs. Riverine, terrestrial input, phytoplankton and sediment release were important sources for the LMWOAs, and human activities were considered as dominant sources for them in sampling period. The consistency of regions with high concentrations of LMWOAs, eutrophication, seasonal hypoxia and frequent red tide occurrence suggested LMWOAs as potential indicators for evaluating pollution status in coastal areas.
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Affiliation(s)
- Lina Lyu
- Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao 266100, PR China; Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China; Qingdao National Laboratory of Marine Science and Technology, Qingdao 266100, PR China
| | - Kejing Fang
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, PR China
| | - Hong Jin
- Shandong Qingdao Eco-Environmental Monitoring Center, Qingdao 266003, PR China
| | - Gui-Peng Yang
- Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao 266100, PR China; Qingdao National Laboratory of Marine Science and Technology, Qingdao 266100, PR China
| | - Haorui Liang
- Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao 266100, PR China
| | - Haibing Ding
- Key Laboratory of Marine Chemistry Theory and Technology, Ocean University of China, Ministry of Education, Qingdao 266100, PR China; Qingdao National Laboratory of Marine Science and Technology, Qingdao 266100, PR China; Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao 266100, PR China.
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Li X, Lai DYF, Gao D. Anaerobic oxidation of methane with denitrification in sediments of a subtropical estuary: Rates, controlling factors and environmental implications. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 273:111151. [PMID: 32758912 DOI: 10.1016/j.jenvman.2020.111151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 06/11/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
Anaerobic oxidation of methane with denitrification (DAMO), as an important microbial process regulating methane emission, has been widely reported in freshwater ecosystems. However, the DAMO process and associated biogeochemical controls in estuaries remain poorly understood. Here, we used 13C- and 15N-labelling experiments to quantify the potential rates of DAMO and determined the crucial factors controlling the DAMO rates in the sediment of Yangtze Estuary. Potential rates of DAMO varied greatly across the estuary, ranging from 0.07 to 0.28 nmol CO2 g-1 d-1. Salinity negatively affected the DAMO and also showed an indirectly negative influence on DAMO process by high salinity inhibition on NO3- availability and denitrification. Nitrate concentrations were significantly correlated with the DAMO rates. Denitrification rates showed positive correlation with DAMO rates, implying that nitrate reduction drives the DAMO process. Sediment total organic carbon and NH4+ had important effects on DAMO rates. These results together indicate that DAMO process can occur and the DAMO rates were mainly controlled by sediment NO3- and denitrification in estuary. We further conclude that increasing NO3- load can drive the DAMO process with more important implications on methane sink in estuarine ecosystems.
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Affiliation(s)
- Xiaofei Li
- Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, 350007, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China.
| | - Derrick Y F Lai
- Department of Geography and Resource Management, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, China
| | - Dengzhou Gao
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, 200241, China
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53
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Chi L, Song X, Yuan Y, Wang W, Cao X, Wu Z, Yu Z. Main factors dominating the development, formation and dissipation of hypoxia off the Changjiang Estuary (CE) and its adjacent waters, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:115066. [PMID: 32806459 DOI: 10.1016/j.envpol.2020.115066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 06/11/2020] [Accepted: 06/17/2020] [Indexed: 06/11/2023]
Abstract
Hypoxia off the Changjiang Estuary (CE) and its adjacent waters is purported to be the most severe in China, attracting considerable concern from both the scientific community and the general public. Currently, continuous observations of dissolved oxygen (DO) levels covering hypoxia from its appearance to disappearance are lacking. In this study, twelve consecutive monthly cruises (from February 2015 to January 2016) were conducted. The consecutive spatiotemporal variations in hypoxia throughout the annual cycle were elucidated in detail, and the responses of annual variations in hypoxia to the different influential factors were explored. Overall, hypoxia experienced a consecutive process of expanding from south to north, then disappearing from north to south. The annual variations in hypoxia were mainly contingent on stratification variations. Among different stages, there was significant heterogeneity in the dominant factors. Specifically, low-DO waters initially appeared from the intrusion of nearshore Kuroshio branch current (NKBC), as NKBC intrusion provided a low-DO background and triggered stratification. Thereafter, stratification was enhanced and gradually expanded northward, which promoted the extension of low-DO areas. The formation of hypoxia was regionally selective, and more intense organic matter decomposition at local regions facilitated the occurrence and discontinuous distribution of hypoxia. Hypoxic zones were observed at the Changjiang bank and Zhejiang coastal region from August (most extensively at 14,800 km2) to October. Thereafter, increased vertical mixing facilitated the dissipation of hypoxia from north to south.
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Affiliation(s)
- Lianbao Chi
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Xiuxian Song
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.
| | - Yongquan Yuan
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Wentao Wang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Xihua Cao
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Zaixing Wu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Zhiming Yu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
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Li X, Hou L, Liu M, Tong C. Biogeochemical controls on nitrogen transformations in subtropical estuarine wetlands. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 263:114379. [PMID: 32203847 DOI: 10.1016/j.envpol.2020.114379] [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: 02/08/2020] [Revised: 03/03/2020] [Accepted: 03/13/2020] [Indexed: 06/10/2023]
Abstract
Changes in soil moisture and salinity are expected to alter gross nitrogen (N) transformations, which can control microbial N dynamics in estuarine wetlands. However, the effects of soil moisture and salinity on microbial N limitation remain poorly understood. To this end, we used a15N pool dilution approach to characterize the changes in soil gross N transformations with the variations of soil moisture in subtropical estuarine wetlands along a low-level salinity gradient. The results showed that soil gross N mineralization (GNM) increased with the increasing soil moisture. Ammonia immobilization (AIM) and microbial N immobilization (MIM) increased with the increasing soil salinity. High gross nitrification rates were generally found in the wetlands with relatively high ammonia content and low soil moisture. The ratios of MIM to GNM (MIM/GNM), as an indicator of microbial N limitation, decreased in response to the enhancing soil moisture and increased with the increasing soil salinity. Ammonia supply capacity (GNM-AIM) decreased with increasing soil salinity but increased with the increasing soil moisture. These results together indicated that microbial N limitation became stronger in the wetlands characterized with high soil salinity and low soil moisture. Soil moisture and salinity exhibited also indirect effects on microbial N limitation through affecting organic N content, ecological stoichiometry, microbial biomass and enzyme activity. Therefore, soil moisture and salinity levels are crucial for controlling soil N transformations with important implications on microbial N removal and retention in estuarine wetlands.
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Affiliation(s)
- Xiaofei Li
- Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, 350007, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
| | - Lijun Hou
- State Key Laboratory of Estuarine and Costal Research, East China Normal University, Shanghai, 200241, China.
| | - Min Liu
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, Shanghai, 200241, China
| | - Chuan Tong
- Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, 350007, China; School of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
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55
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Wei H, Gao D, Liu Y, Lin X. Sediment nitrate reduction processes in response to environmental gradients along an urban river-estuary-sea continuum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 718:137185. [PMID: 32092511 DOI: 10.1016/j.scitotenv.2020.137185] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/29/2020] [Accepted: 02/06/2020] [Indexed: 06/10/2023]
Abstract
Sediment denitrification (DEN), anaerobic ammonium oxidation (Anammox), and dissimilatory nitrate reduction to ammonium (DNRA) are three important nitrate (NO3-) reduction pathways in aquatic ecosystems. These processes modify nitrogen (N) loadings from land to the ocean, with important implications on the management of coastal eutrophication. While NO3- reduction has been studied intensively for various types of habitats, studies on its distributions along river-estuary-sea continua remain scarce. In this study, we examined these three pathways along a N-laden urban river-estuary-sea continuum comprised of three types of habitats (urban river, estuary, and adjacent sea) in the densely populated Shanghai-East China Sea area. The potential DEN, Anammox, and DNRA rates decreased seaward both in summer and winter in response to decreasing sediment organic matter (OM, 20 to 7 to 7 mg C g-1), ferrous oxide (9 to 2.7 to 2.8 mg Fe g-1), and bottom water dissolved inorganic nitrogen (543 to 112 to 21 μM). Among these pathways, DEN remained a major component (~69.6%) across habitats, while Anammox (47.9%) rivaled DEN (48.3%) in the urban river in winter. N retention index (NIRI), the ratio between retained and removed NO3-, ranged from 0 to 0.5 and increased downstream. Together, these results suggest that the decreasing gradients of OM and inorganic matter shape the distribution of NO3- reduction along the continuum, reflecting the diminishing impact of the river and human inputs from the urban river to the ocean. Our results highlight the importance of taking a continuum perspective in N cycling studies and emphasize the role of urban rivers as N removal hotspots, which should be a focus of research and management.
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Affiliation(s)
- Hengchen Wei
- The University of Texas at Austin Marine Science Institute, 750 Channel View Drive, Port Aransas, TX 78373, USA
| | - Dengzhou Gao
- School of Geographic Sciences, Key Laboratory of Geographic Information Science of the Ministry of Education, East China Normal University, Shanghai 200241, China
| | - Yong Liu
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Guangzhou 510300, China
| | - Xianbiao Lin
- Laboratory of Microbial Ecology and Matter Cycles, School of Marine Sciences, Sun Yat-Sen University, Zhuhai 519082, China; School of Geographic Sciences, Key Laboratory of Geographic Information Science of the Ministry of Education, East China Normal University, Shanghai 200241, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China.
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56
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Zhu L, Shi W, Van Dam B, Kong L, Yu J, Qin B. Algal Accumulation Decreases Sediment Nitrogen Removal by Uncoupling Nitrification-Denitrification in Shallow Eutrophic Lakes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:6194-6201. [PMID: 32191831 DOI: 10.1021/acs.est.9b05549] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In eutrophic lakes, the decay of settled algal biomass generates organic carbon and consumes oxygen, favoring sediment nitrogen loss via denitrification. However, persistent winds can cause algae to accumulate into dense mats, with uncertain impacts on sediment nitrogen removal. In this study, we investigated the effects of algal accumulation on sediment nitrogen removal in a shallow and eutrophic Chinese lake, Taihu. We found that experimental treatments of increased algal accumulation were associated with decreased sediment nitrogen losses, indicating the potential for a break in coupled nitrification-denitrification. Likewise, field measurements indicated similar decreases in sediment nitrogen losses when algal accumulation occurred. It is possibly caused by the decay of excess algal biomass, which likely depleted dissolved oxygen, and could have inhibited nitrification and thereby denitrification in sediments. We estimate that if such algal accumulations occurred over 20% or 10% of lake area in Taihu, sediment nitrogen removal rates decreased from 835.6 to 167.2 and 77.2 μmol N m-2h-1, respectively, during algal accumulation period. While nitrogen removal may recover later, the apparent nitrogen removal decrease may create a window for algal proliferation and intensification. This study advances our knowledge on the impacts of algal blooms on nitrogen removal in shallow eutrophic lakes.
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Affiliation(s)
- Lin Zhu
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technologies, Jiangsu Key Laboratory of Atmospheric Environmental Monitoring & Pollution Control, School of Environmental Science & EngineeringNanjing University of Information Science & Technology, Nanjing 210044, China
| | - Wenqing Shi
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technologies, Jiangsu Key Laboratory of Atmospheric Environmental Monitoring & Pollution Control, School of Environmental Science & EngineeringNanjing University of Information Science & Technology, Nanjing 210044, China
- Center for Eco-Environmental Research, Nanjing Hydraulic Research Institute, Guangzhou Road 223, Nanjing 210029, China
| | - Bryce Van Dam
- Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Geesthacht, 21502, Germany
| | - Lingwei Kong
- Environmental Science Research and Design Institute of Zhejiang Province, Hangzhou, 310007, China
| | - Jianghua Yu
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technologies, Jiangsu Key Laboratory of Atmospheric Environmental Monitoring & Pollution Control, School of Environmental Science & EngineeringNanjing University of Information Science & Technology, Nanjing 210044, China
| | - Boqiang Qin
- School of Geography & Ocean Science, Nanjing University, Nanjing 210044, China
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
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57
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Liu J, Krom MD, Ran X, Zang J, Liu J, Yao Q, Yu Z. Sedimentary phosphorus cycling and budget in the seasonally hypoxic coastal area of Changjiang Estuary. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 713:136389. [PMID: 31954248 DOI: 10.1016/j.scitotenv.2019.136389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/26/2019] [Accepted: 12/26/2019] [Indexed: 06/10/2023]
Abstract
Anthropogenic activities have greatly accelerated phosphorus (P) inputs from land to coastal seas. The increased P inputs from major rivers can cause adjacent coastal areas to experience seasonal hypoxia with the enhancing coastal eutrophication, which can subsequently increase P cycling and alter long term preservation. Analysis of sediment core measurements including SEDEX P speciation coupled with diagenetic kinetic models were performed on two cores in the coastal area under the Changjiang river plume, that experiences seasonal hypoxia. It was found that the benthic flux of dissolved reactive phosphate (DRP) in the Changjiang Estuary (CJE) was higher than that of adjacent areas of the Chinese coastal shelf. Sedimentary phosphorus transformations of Fe-bound P and organic P resulted in the in-situ formation of authigenic P (probably apatite), which was the major form of reactive P buried in the sediment. P burial efficiency (PBE) was lower than that of the oxic Chinese shelf but higher than that of other seasonally hypoxic areas in the world away from major river inputs. An exponential relationship between PBE and bottom water dissolved oxygen was developed, which suggested a positive feedback mechanism of increased hypoxia increasing P recycling, and hence intensifying eutrophication. The relatively high input of sediment including detrital P from the adjacent major river can explain many of the observed differences in P cycling from other seasonally hypoxic areas.
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Affiliation(s)
- Jun Liu
- First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
| | - Michael D Krom
- Morris Kahn Marine station, Department of Marine Biology, University of Haifa, Mount Carmel, Haifa 31905, Israel.
| | - Xiangbin Ran
- First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
| | - Jiaye Zang
- First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China.
| | - Jihua Liu
- First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
| | - Qingzhen Yao
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
| | - Zhigang Yu
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
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58
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Man X, Bierlein KA, Lei C, Bryant LD, Wüest A, Little JC. Improved Modeling of Sediment Oxygen Kinetics and Fluxes in Lakes and Reservoirs. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2658-2666. [PMID: 31971782 DOI: 10.1021/acs.est.9b04831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
To understand water quality degradation during hypoxia, we need to understand sediment oxygen fluxes, the main oxygen sink in shallow hypolimnia. Kinetic models, which integrate diffusion and consumption of dissolved oxygen (DO) in sediments, usually assume a downward flux of DO from the sediment-water interface (SWI) with a zero-flux condition at the lower boundary of the oxic sediment layer. In this paper, we separately account for the oxidation of an upward flux of reduced compounds by introducing a negative flux of DO as a lower boundary condition. Using in situ measurements in two lakes, kinetic models were fit to DO microprofiles using zero-order and first-order kinetics with both zero and non-zero lower boundary conditions. Based on visual inspection and goodness-of-fit criteria, the negative-flux lower boundary condition, -0.25 g O2 m-2 d-1, was found to more accurately describe DO consumption kinetics. Fitted zero-order rate constants ranged from 50 to 510 mg L-1 d-1, and first-order rate constants ranged from 60 to 400 d-1, which agree well with prior laboratory studies. DO fluxes at the SWI calculated from the simulated profiles with the negative-flux lower boundary condition also showed better agreement with the observed DO fluxes than the simulated profiles with the zero-flux lower boundary condition.
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Affiliation(s)
- Xiamei Man
- Centre for Wind, Waves and Water, School of Civil Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Kevin A Bierlein
- Department of Civil and Environmental Engineering, Virginia Tech, 401 Durham Hall, Blacksburg, Virginia 24061-0246, United States
| | - Chengwang Lei
- Centre for Wind, Waves and Water, School of Civil Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Lee D Bryant
- Department of Architecture and Civil Engineering, University of Bath, Bath BA2 7AY, United Kingdom
| | - Alfred Wüest
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Surface Waters - Research and Management, CH-6047 Kastanienbaum, Switzerland
- Physics of Aquatic Systems Laboratory, Margaretha Kamprad Chair, ENAC-IEE-APHYS, Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne, Switzerland
| | - John C Little
- Department of Civil and Environmental Engineering, Virginia Tech, 401 Durham Hall, Blacksburg, Virginia 24061-0246, United States
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Chen CC, Gong GC, Chou WC, Shiah FK. Hypoxia in autumn of the East China Sea. MARINE POLLUTION BULLETIN 2020; 152:110875. [PMID: 31957672 DOI: 10.1016/j.marpolbul.2019.110875] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 12/29/2019] [Accepted: 12/31/2019] [Indexed: 06/10/2023]
Abstract
Hypoxia (O2 ≤ 2 mg L-1) can severely threaten the survival of marine life and alter the biogeochemical cycles of coastal ecosystems. Its impacts are dependent on its duration. In the present study, hypoxia was observed in autumn at the end of October 2011. It may be one of the latest recorded annual hypoxic events in the East China Sea (ECS). In the hypoxic regions, a large amount of nutrients and dissolved inorganic carbon were observed to regenerate. Also, acidification (low pH) was observed. On the other hand, hypoxic dissipation may be due to the destratification caused by the upwelling of the hypoxic regions in the ECS. These results suggest that hypoxia may occur for longer periods of time than expected and, accordingly, the effects of hypoxia on the ECS ecosystems should be reconsidered and further evaluated.
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Affiliation(s)
- Chung-Chi Chen
- Department of Life Science, National Taiwan Normal University, 88, Sec. 4, Ting-Chou Rd., Taipei 11677, Taiwan.
| | - Gwo-Ching Gong
- Institute of Marine Environment and Ecology and Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Wen-Chen Chou
- Institute of Marine Environment and Ecology and Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Fuh-Kwo Shiah
- Institute of Marine Environment and Ecology and Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan.; Research Center for Environment Changes, Academia Sinica, NanKang, Taipei 11529, Taiwan
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60
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Ji X, Liu C, Pan G. Interfacial oxygen nanobubbles reduce methylmercury production ability of sediments in eutrophic waters. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 188:109888. [PMID: 31706242 DOI: 10.1016/j.ecoenv.2019.109888] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/23/2019] [Accepted: 10/27/2019] [Indexed: 06/10/2023]
Abstract
Eutrophication can induce hypoxia/anoxia and rich organic matter at the sediment-water interface in surface waters. When eutrophic waters are impacted with mercury (Hg) pollution, methylmercury (MeHg) production ability (MPA) of surface sediment would increase and more MeHg might be produced. To tackle this risk, this study firstly collected samples of surface sediment and overlying water from a typical eutrophic lake-Taihu Lake. Then from a sediment-water simulation system, we demonstrated that eutrophic waters were able to methylate Hg spontaneously, and that sediment is the major Hg sink in the system. After the addition of HgCl2 solution (approximately 1 mg L-1 in the slurry), MeHg concentrations in the sediment increased by 11.7 times after 48 h. The subsequent column experiments proved that O2 nanobubbles could significantly decrease the MPA of surface sediment, by up to 48%. Furthermore, we found that O2 nanobubbles could remediate anoxia mainly by increasing dissolved oxygen (from 0 to 2.1 mg L-1), oxidation-reduction potentials (by 37% on average), and sulfate (by 31% on average) in the overlying water. In addition, O2 nanobubbles could also help decrease organic matter concentration, as was revealed by the decline of dissolved organic carbon in the overlying water (by up to 57%) and total organic carbon in surface sediment (by up to 37%). The remediation of anoxia and reduction of organic matter could contribute to the decrease of hgcA gene abundance (by up to 86%), and thus result in the reduction of MPA after the addition of O2 nanobubbles. This study revealed the risk of MeHg production in case Hg pollution occurs in eutrophic waters and proposed a feasible solution for MeHg remediation.
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Affiliation(s)
- Xiaonan Ji
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Chengbin Liu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, 200092, PR China
| | - Gang Pan
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; Beijing Advanced Science and Innovation Center, Chinese Academy of Sciences, Beijing, 101407, PR China; Center of Integrated Water-Energy-Food Studies (iWEF), School of Animal, Rural, and Environmental Sciences, Nottingham Trent University, Brackenhurst Campus, NG25 0QF, UK.
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61
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Zhao W, Zheng Z, Zhang J, Roger SF, Luo X. Evaluation of the use of eucalyptus to control algae bloom and improve water quality. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 667:412-418. [PMID: 30833239 DOI: 10.1016/j.scitotenv.2019.02.276] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/17/2019] [Accepted: 02/17/2019] [Indexed: 06/09/2023]
Abstract
Lakes represent an important source of drinking water resource for human beings. The presence of harmful algae blooms can pose a serious threat to lakes water quality. This study explored the feasibility of using eucalyptus plants and leaves extracts for controlling algae proliferation in an aquatic milieu. After 30 days of treatment, the inhibitory efficiencies were 85.8% and 20.9% for treatments planting eucalyptus and eucalyptus leaves extracts, respectively. The synergistic effects of allelopathy and competitive absorption for macro nutrients were attributed to the effective control of algae proliferation in the mesocosm systems. Moreover, the analysis of microbial community structures indicated that eucalyptus plants or leaves extracts had no adverse effect on species diversity and their relative abundance. The choice of using eucalyptus to control algae bloom will be dictated by environmental and economic considerations within a geographical region.
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Affiliation(s)
- Wei Zhao
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Zheng Zheng
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China.
| | - JunLei Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Saint-Fort Roger
- Department of Environmental Science, Mount Royal University, Calgary, AB T3E 6K6, Canada
| | - XingZhang Luo
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
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Wei Q, Wang B, Yao Q, Xue L, Sun J, Xin M, Yu Z. Spatiotemporal variations in the summer hypoxia in the Bohai Sea (China) and controlling mechanisms. MARINE POLLUTION BULLETIN 2019; 138:125-134. [PMID: 30660253 DOI: 10.1016/j.marpolbul.2018.11.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 11/15/2018] [Accepted: 11/17/2018] [Indexed: 06/09/2023]
Abstract
Based on field observations in the summer of 2006 and long-term series data, this paper investigates the spatiotemporal variations of hypoxia and associated physical-biogeochemical driving mechanisms in the Bohai Sea (BS), China. Results show that the benthic hypoxic zone is mainly distributed in the "V"-shaped trough region in the western BS, and it tends to form two hypoxic centers which generally correspond to the bottom cold-water core. The regional difference in the intensity of stratification has a significant impact on the spatial distribution of hypoxia. The relatively weak stratification and the mesoscale anticyclonic eddy in the central shoal of the BS weaken the connectivity between the southern and northern hypoxic zones. Organic matter decomposition contributes to hypoxia and results in corresponding nutrient pool with a "dual (southern and northern)-core" structure. Intensified eutrophication is the main drive for decreasing in bottom dissolved oxygen and expansion of hypoxic zone in the BS.
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Affiliation(s)
- Qinsheng Wei
- First Institute of Oceanography, State Oceanic Administration, 6 Xianxialing Road, Qingdao 266061, PR China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China.
| | - Baodong Wang
- First Institute of Oceanography, State Oceanic Administration, 6 Xianxialing Road, Qingdao 266061, PR China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China
| | - Qingzhen Yao
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China
| | - Liang Xue
- First Institute of Oceanography, State Oceanic Administration, 6 Xianxialing Road, Qingdao 266061, PR China
| | - Junchuan Sun
- First Institute of Oceanography, State Oceanic Administration, 6 Xianxialing Road, Qingdao 266061, PR China
| | - Ming Xin
- First Institute of Oceanography, State Oceanic Administration, 6 Xianxialing Road, Qingdao 266061, PR China
| | - Zhigang Yu
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, 238 Songling Road, Qingdao 266100, PR China
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63
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Wang H, Hu X, Wetz MS, Hayes KC. Oxygen Consumption and Organic Matter Remineralization in Two Subtropical, Eutrophic Coastal Embayments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:13004-13014. [PMID: 30346150 DOI: 10.1021/acs.est.8b02971] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
There is a strong need to understand sources of organic matter in coastal lagoons because these systems often have long water residence times, are susceptible to eutrophication, and display symptoms such as low-oxygen conditions. We found that integrated dissolved oxygen (DO) consumption in the water column accounted for 67-73% of total DO consumption in two eutrophic coastal lagoons (Baffin Bay and Oso Bay) in the northwestern Gulf of Mexico. The δ13C of particulate organic carbon (δ13CPOC) showed temporal variations that corresponded with hydrological condition changes in Baffin Bay but fewer temporal changes in Oso Bay, whereas the lower δ15NPON values in Baffin Bay indicated more agricultural influence than in Oso Bay, where urban sewage influences dominated. Based on closed-system incubation experiments, water-column respiration in Baffin Bay was driven by the respiration of a combination of phytoplankton, carbon from near-shore and benthic macrophytes, and other allochthonous organic carbon sources depending on hydrological conditions. However, respiration of algal carbon dominated DO consumption in Baffin Bay sediments. In comparison, Oso Bay water-column respiration was largely attributed to the degradation of phytoplankton, the growth of which was sustained by nutrient discharge from wastewater treatment plants in the watershed. In contrast to the water column, seagrass and saltmarsh carbon appeared to be the primary organic carbon source that drove DO consumption in Oso Bay sediments. These observations highlight the complexity of organic carbon sources that contribute to DO consumption in estuaries affected by human activities, especially in systems with long water residence times that can retain both organic matter and nutrients for extended periods of time.
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Yang X, Zheng X, Wu L, Cao X, Li Y, Niu J, Meng F. Interactions between algal (AOM) and natural organic matter (NOM): Impacts on their photodegradation in surface waters. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 242:1185-1197. [PMID: 30114600 DOI: 10.1016/j.envpol.2018.07.099] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/08/2018] [Accepted: 07/21/2018] [Indexed: 06/08/2023]
Abstract
The occurrence of algae bloom would lead to the release of algae-derived organic matter (AOM) and then alter the abundance and behavior of dissolved organic matter (DOM) in aquatic ecosystems. In this study, the characteristics and photodegradation of AOM, naturally occurring organic matter (NOM) derived from soil and plants and their mixtures were explored to reveal the potential interactions between AOM and NOM in water. Results indicated that the protein-like components from AOM and the humic-like components from SRNOM took place inter-component interactions in the AOM-NOM mixtures. Meanwhile, application of two-dimensional Fourier transform infrared correlation spectroscopic (2D-FTIR-COS) analysis revealed that carboxylic C=O had a high priority to bind with other functional groups (e.g., phenolic-OH, polysaccharides C-O, amideⅡC-N/N-H and celluloses C-H). More crucially, it was found that the AOM-NOM mixtures subjected to a very different photodegradation behavior to their end-members (i.e., AOM and NOM), likely because of the occurrence of AOM-NOM interactions as well as their roles in mediating the yield of reactive oxygen species. For instance, the presence of AOM led to increased photodegradation degrees of the chromophoric fraction in NOM. In contrast, the NOM did not exhibit any photosensitization role in the photodegradation of the proteins from AOM. This study has potential implications for our understanding of the carbon cycling in anthropogenically impacted aquatic systems such as inland rivers and lakes.
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Affiliation(s)
- Xiaofang Yang
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China
| | - Xing Zheng
- Department of Civil and Environmental Engineering, Xi'an University of Technology, Xi'an 710048, China
| | - Linjie Wu
- Department of Civil and Environmental Engineering, Xi'an University of Technology, Xi'an 710048, China
| | - Xin Cao
- Department of Civil and Environmental Engineering, Xi'an University of Technology, Xi'an 710048, China
| | - Yi Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, China
| | - Junfeng Niu
- Dongguan University of Technology, School of Environment and Civil Engineering, Dongguan, China
| | - Fangang Meng
- School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China.
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65
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Lin Q, Yu S. Losses of natural coastal wetlands by land conversion and ecological degradation in the urbanizing Chinese coast. Sci Rep 2018; 8:15046. [PMID: 30301927 PMCID: PMC6177474 DOI: 10.1038/s41598-018-33406-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 08/10/2018] [Indexed: 11/09/2022] Open
Abstract
Coastal wetland ecosystems have experienced serious losses of area and ecological function and are currently facing worldwide challenges due to coastal development and global climate change. This study attempted to explore patterns and possible factors driving loss of natural coastal wetlands due to land conversion (permanent loss) and ecological degradation (temporal loss) in three urbanizing coastal city clusters, China in the period of 1990-2015. The natural coastal wetland area was substantially lost due to land conversion highly related to regional economic development. The ecological degradation, assessed as a function of surface water quality, resulted in much greater impairment area of natural coastal wetlands. This impairment was predominantly driven by inbound river pollutants' discharge, rather than local discharge. This study suggests that the ecological degradation should be considered as well as the land conversion loss for conserving the remaining natural coastal wetland ecosystems. The pollutant discharges from the inbound river watersheds need to be mitigated as the local discharges for reducing the functional degradation of the natural coastal wetlands while the regional economic development plan should consider the conservation needs of the remaining natural coastal wetlands worldwide.
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Affiliation(s)
- Qiaoying Lin
- CAS Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.,University of Chinese Academy of Sciences, Beijing, 100006, China.,Quanzhou Normal University, Quanzhou, 362000, China
| | - Shen Yu
- CAS Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
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66
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Shi W, Pan G, Chen Q, Song L, Zhu L, Ji X. Hypoxia Remediation and Methane Emission Manipulation Using Surface Oxygen Nanobubbles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8712-8717. [PMID: 30001132 DOI: 10.1021/acs.est.8b02320] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Algal blooms in eutrophic waters often induce anoxia/hypoxia and enhance methane (CH4) emissions to the atmosphere, which may contribute to global warming. At present, there are very few strategies available to combat this problem. In this study, surface oxygen nanobubbles were tested as a novel approach for anoxia/hypoxia remediation and CH4 emission control. Incubation column experiments were conducted using sediment and water samples taken from Lake Taihu, China. The results indicated that algae-induced anoxia/hypoxia could be reduced or reversed after oxygen nanobubbles were loaded onto zeolite micropores and delivered to anoxic sediment. Cumulated CH4 emissions were also reduced by a factor of 3.2 compared to the control. This was mainly attributed to the manipulation of microbial processes using the surface oxygen nanobubbles, which potentially served as oxygen suppliers. The created oxygen-enriched environment simultaneously decreased methanogen but increased methanotroph abundances, making a greater fraction of organic carbon recycled as carbon dioxide (CO2) instead of CH4. The CH4/CO2 emission ratio decreased to 3.4 × 10-3 in the presence of oxygen nanobubbles, compared to 11 × 10-3 in the control, and therefore the global warming potential was reduced. This study proposes a possible strategy for anoxia/hypoxia remediation and CH4 emission control in algal bloom waters, which may benefit global warming mitigation.
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Affiliation(s)
- Wenqing Shi
- Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- Center for Eco-Environment Research , Nanjing Hydraulic Research Institute , Nanjing 210098 , China
| | - Gang Pan
- Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
- School of Animal, Rural, and Environmental Sciences , Nottingham Trent University , Nottingham NG25 0QF , U.K
| | - Qiuwen Chen
- Center for Eco-Environment Research , Nanjing Hydraulic Research Institute , Nanjing 210098 , China
| | - Lirong Song
- Institute of Hydrobiology , Chinese Academy of Sciences , Wuhan 430075 , China
| | - Lin Zhu
- School of Environmental Science & Engineering , Nanjing University of Information Science & Technology , Nanjing 210044 , China
| | - Xiaonan Ji
- Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , China
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Zhu Q, de Vries W, Liu X, Hao T, Zeng M, Shen J, Zhang F. Enhanced acidification in Chinese croplands as derived from element budgets in the period 1980-2010. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 618:1497-1505. [PMID: 29089131 DOI: 10.1016/j.scitotenv.2017.09.289] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/26/2017] [Accepted: 09/26/2017] [Indexed: 05/25/2023]
Abstract
Significant soil pH decrease has been reported in Chinese croplands in response to enhanced chemical fertilizer application and crop yields. However, the temporal and spatial variation of soil acidification rates across Chinese croplands is still unclear. We therefore assessed trends in soil acidification rates across provincial China for the period 1980-2010 by calculating inputs-outputs of major cations and anions in cropland systems. Nitrogen (N) induced proton production increased from 4.7keqH+/ha/yr in 1980 to a peak of 11.0keqH+/ha/yr in 1996 and remained nearly constant after 2000 at a rate of approximately 8.6keqH+/ha/yr. The proton production induced by crop removal increased from 1.2 to 2.3keqH+/ha/yr. The total proton production thus increased from 5.9 to 10.9keqH+/ha/yr in the 30years. As a result, the actual acidification rate, reflected by (base) cation losses, accelerated from 2.3 to 6.2keqH+/ha/yr and the potential acidification rate, reflected by phosphorus accumulation accelerated from 0.2 to 1.3keqH+/ha/yr. The national averaged total acidification rates were thus estimated to increase from 2.6 to 7.6keqH+/ha/yr in the past 30years. The highest soil acidification rate occurred in the Jiangsu Province with a rate of 17.9keqH+/ha/yr, which was due to both high N application rates and high base cation removals by crops and crop residues. The combination of elevated N inputs and decreased N use efficiency (NUE) in response to those N inputs, thus enhancing the nitrate discharge, were the main reasons for the accelerated acidification in Chinese croplands. Considering the expected growth of food demand in the future, and the linkage between grain production and fertilizer N consumption, a further acceleration of soil acidification can thus be expected, unless the N inputs is reduced and/or the NUE is increased substantially.
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Affiliation(s)
- Qichao Zhu
- College of Resources and Environmental Sciences, Centre for Resources, Environment and Food Security, Key Lab of Plant-Soil Interactions, MOE, China Agricultural University, Beijing 100193, China
| | - Wim de Vries
- Environmental Systems Analysis Group, Wageningen University, PO Box 47, 6700 AA Wageningen, The Netherlands; Alterra-Wageningen UR, Soil Science Centre, PO Box 47, 6700 AA Wageningen, The Netherlands
| | - Xuejun Liu
- College of Resources and Environmental Sciences, Centre for Resources, Environment and Food Security, Key Lab of Plant-Soil Interactions, MOE, China Agricultural University, Beijing 100193, China.
| | - Tianxiang Hao
- College of Resources and Environmental Sciences, Centre for Resources, Environment and Food Security, Key Lab of Plant-Soil Interactions, MOE, China Agricultural University, Beijing 100193, China
| | - Mufan Zeng
- College of Resources and Environmental Sciences, Centre for Resources, Environment and Food Security, Key Lab of Plant-Soil Interactions, MOE, China Agricultural University, Beijing 100193, China
| | - Jianbo Shen
- College of Resources and Environmental Sciences, Centre for Resources, Environment and Food Security, Key Lab of Plant-Soil Interactions, MOE, China Agricultural University, Beijing 100193, China
| | - Fusuo Zhang
- College of Resources and Environmental Sciences, Centre for Resources, Environment and Food Security, Key Lab of Plant-Soil Interactions, MOE, China Agricultural University, Beijing 100193, China
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Chi L, Song X, Yuan Y, Wang W, Zhou P, Fan X, Cao X, Yu Z. Distribution and key influential factors of dissolved oxygen off the Changjiang River Estuary (CRE) and its adjacent waters in China. MARINE POLLUTION BULLETIN 2017; 125:440-450. [PMID: 29029983 DOI: 10.1016/j.marpolbul.2017.09.063] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/24/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
Based on two multidisciplinary investigations conducted in summer and winter 2015, the distribution of dissolved oxygen (DO) and the associated seasonal variations off the Changjiang River Estuary (CRE) were studied. The DO content was high in winter, ranging from 6.81-10.29mg/L, and the distribution was mainly controlled by temperature and salinity. The DO concentration was 1.92-9.67mg/L in summer, and a hypoxic zone (DO<3mg/L) covered 14,800km2, which was mainly controlled by stratification and organic matter decomposition. The hypoxic zone exhibited a "dual-core" structure and the differences in the biochemical and physical processes between the southern and northern regions were compared: the northern region exhibited stronger pycnocline intensity; while larger biomass and higher TOC as well as TN contents were observed in the southern region. Hypoxia in the northern region might be mainly dominated by stratification, while that in the southern region was mainly associated with organic matter decomposition.
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Affiliation(s)
- Lianbao Chi
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Xiuxian Song
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
| | - Yongquan Yuan
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China
| | - Wentao Wang
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China
| | - Peng Zhou
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Xin Fan
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Xihua Cao
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China
| | - Zhiming Yu
- Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, People's Republic of China; Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
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Shi W, Chen Q, Yi Q, Yu J, Ji Y, Hu L, Chen Y. Carbon Emission from Cascade Reservoirs: Spatial Heterogeneity and Mechanisms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:12175-12181. [PMID: 28965393 DOI: 10.1021/acs.est.7b03590] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Carbon emission from reservoirs is considered to tarnish the green credentials of hydropower and has been extensively studied in single reservoirs. However, it remains unclear how carbon emission differs in cascade reservoirs and the mechanism behind the differences. In this study, carbon dioxide (CO2) and methane (CH4) emissions from cascade hydropower reservoirs were measured in the Lancang River, the Chinese section of the Mekong River. Our results demonstrate that carbon emissions from the river were increased by dam construction but exhibited spatial heterogeneity among cascade reservoirs. The first, most upstream, reservoir acted as the hotspot of CH4 and CO2 emissions, which were 13.1 and 1.7 times higher than those in downstream reservoirs, respectively. Similarly, the CH4/CO2 ratio of 0.023 in the first reservoir was higher than the others and made a greater contribution to the global warming effects of the cascade reservoirs. The sediment organic carbon in downstream reservoirs was negatively correlated with reservoir age (r2 = 0.993) and decreased at a rate of 0.389 mg g-1 yr-1, suggesting a potential decrease of carbon emission in the future. This study adds to our understanding of carbon emissions from cascade reservoirs and helps to screen effective strategies for future mitigation of the global warming effects from cascade hydropower systems.
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Affiliation(s)
- Wenqing Shi
- Center for Eco-Environment Research, Nanjing Hydraulic Research Institute , Nanjing 210098, China
| | - Qiuwen Chen
- Center for Eco-Environment Research, Nanjing Hydraulic Research Institute , Nanjing 210098, China
| | - Qitao Yi
- School of Earth and Environment, Anhui University of Science and Technology , Huainan 232001, China
| | - Juhua Yu
- Center for Eco-Environment Research, Nanjing Hydraulic Research Institute , Nanjing 210098, China
| | - Yuyu Ji
- Center for Eco-Environment Research, Nanjing Hydraulic Research Institute , Nanjing 210098, China
- College of Water Conservancy and Hydropower Engineering, Hohai University , Nanjing 210098, China
| | - Liuming Hu
- Center for Eco-Environment Research, Nanjing Hydraulic Research Institute , Nanjing 210098, China
| | - Yuchen Chen
- Center for Eco-Environment Research, Nanjing Hydraulic Research Institute , Nanjing 210098, China
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70
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Lee SY, Khim JS. Hard science is essential to restoring soft-sediment intertidal habitats in burgeoning East Asia. CHEMOSPHERE 2017; 168:765-776. [PMID: 27838029 DOI: 10.1016/j.chemosphere.2016.10.136] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 10/24/2016] [Accepted: 10/30/2016] [Indexed: 06/06/2023]
Abstract
Intertidal soft-sediment ecosystems such as mangrove, saltmarsh, and tidal flats face multiple stresses along the burgeoning East Asia coastline. In addition to direct habitat loss, ecosystem structure, function, and capacity for ecosystem services of these habitats are significantly affected by anthropogenic loss of hydrologic connectivity, introduction of invasive exotic species, and chemical pollution. These dramatic changes to ecosystem structure and function are illustrated by four case studies along the East Asian coast: the Mai Po Marshes in Hong Kong, the Yunxiao wetlands in Fujian, China, and the Lake Sihwa and Saemangeum tidal flats in Korea. While investment in restoration is increasing significantly in the region, the lack of key basic knowledge on aspects of the behaviour of intertidal soft-sediment ecosystems, particularly those in Asia, impairs the effectiveness of these efforts. The relationship between biodiversity and ecosystem function for relatively species-poor mangrove, seagrass, and saltmarsh systems has implications for restoration targeting monospecific plantations. The trajectory of recovery and return of ecosystem function and services is also poorly known, and may deviate from simple expectations. As many introduced species have become established along the East Asian coast, their long-term impact on ecosystem function as well as the socio-economics of coastal communities demand a multidisciplinary approach to assessing options for restoration and management. These knowledge gaps require urgent attention in order to inform future restoration and management of intertidal soft-sediment ecosystems in fast-developing East Asia.
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Affiliation(s)
- Shing Yip Lee
- Australian Rivers Institute and School of Environment, Griffith University, Southport, QLD 4222, Australia.
| | - Jong Seong Khim
- School of Earth and Environmental Sciences & Research Institute of Oceanography, Seoul National University, Seoul 08826, Republic of Korea
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Gurkov A, Shchapova E, Bedulina D, Baduev B, Borvinskaya E, Meglinski I, Timofeyev M. Remote in vivo stress assessment of aquatic animals with microencapsulated biomarkers for environmental monitoring. Sci Rep 2016; 6:36427. [PMID: 27808253 PMCID: PMC5093551 DOI: 10.1038/srep36427] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 10/14/2016] [Indexed: 01/21/2023] Open
Abstract
Remote in vivo scanning of physiological parameters is a major trend in the development of new tools for the fields of medicine and animal physiology. For this purpose, a variety of implantable optical micro- and nanosensors have been designed for potential medical applications. At the same time, the important area of environmental sciences has been neglected in the development of techniques for remote physiological measurements. In the field of environmental monitoring and related research, there is a constant demand for new effective and quick techniques for the stress assessment of aquatic animals, and the development of proper methods for remote physiological measurements in vivo may significantly increase the precision and throughput of analyses in this field. In the present study, we apply pH-sensitive microencapsulated biomarkers to remotely monitor the pH of haemolymph in vivo in endemic amphipods from Lake Baikal, and we compare the suitability of this technique for stress assessment with that of common biochemical methods. For the first time, we demonstrate the possibility of remotely detecting a change in a physiological parameter in an aquatic organism under ecologically relevant stressful conditions and show the applicability of techniques using microencapsulated biomarkers for remote physiological measurements in environmental monitoring.
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Affiliation(s)
- Anton Gurkov
- Irkutsk State University, Institute of Biology, Irkutsk, 664003, Russia
| | | | - Daria Bedulina
- Irkutsk State University, Institute of Biology, Irkutsk, 664003, Russia
| | - Boris Baduev
- Irkutsk State University, Institute of Biology, Irkutsk, 664003, Russia
| | - Ekaterina Borvinskaya
- Irkutsk State University, Institute of Biology, Irkutsk, 664003, Russia.,Karelian Research Centre of Russian Academy of Sciences, Institute of Biology, Petrozavodsk, 185035, Russia
| | - Igor Meglinski
- Irkutsk State University, Institute of Biology, Irkutsk, 664003, Russia.,University of Oulu, Optoelectronics and Measurement Techniques Laboratory, Oulu, 90570, Finland
| | - Maxim Timofeyev
- Irkutsk State University, Institute of Biology, Irkutsk, 664003, Russia
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Martínez-Ruiz EB, Martínez-Jerónimo F. How do toxic metals affect harmful cyanobacteria? An integrative study with a toxigenic strain of Microcystis aeruginosa exposed to nickel stress. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2016; 133:36-46. [PMID: 27400062 DOI: 10.1016/j.ecoenv.2016.06.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/20/2016] [Accepted: 06/22/2016] [Indexed: 06/06/2023]
Abstract
Nickel (Ni) is an essential metal for some organisms, but also a common toxic pollutant released into the water. Toxicity of Ni has not been completely established for cyanobacteria; for this reason, we evaluated the effect of sub-inhibitory Ni concentrations on a toxigenic strain of Microcystis aeruginosa and on microcystins production. Population growth, photosynthetic pigments concentration, biomarkers, including antioxidant enzymes (catalase [CAT], glutathione peroxidase [GPx], and superoxide dismutase [SOD]), as well as macromolecules (proteins, carbohydrates and lipids) were quantified; SEM and TEM observations were also performed. Population growth was affected starting at 3µgL(-1), and at 24µgL(-1) growth was completely inhibited; the 96-h Ni(2+) IC50 was 3.7µgL(-1). Ni exposure increased pigments concentration, augmented all the macromolecules, and increased activities of CAT and GPx; alterations on the internal cell structure were also observed. The integrated biomarker response revealed that Ni(2+) augmented the antioxidant response and the macromolecules content. Ni stress also increased microcystins production. M. aeruginosa was affected by Ni at very low concentrations, even lower than those established as safe limit to protect aquatic biota. Aside from the toxic effects produced in this cyanobacterium, stimulation to produce toxins could potentiate the environmental risks associated with water pollution and eutrophication.
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Affiliation(s)
- Erika Berenice Martínez-Ruiz
- Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Laboratorio de Hidrobiología Experimental, Carpio y Plan de Ayala S/N, Col. Santo Tomás, Mexico, D.F. 11340, Mexico
| | - Fernando Martínez-Jerónimo
- Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Laboratorio de Hidrobiología Experimental, Carpio y Plan de Ayala S/N, Col. Santo Tomás, Mexico, D.F. 11340, Mexico.
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Zhang W, Jin X, Zhu X, Shan B, Zhao Y. Phosphorus characteristics, distribution, and relationship with environmental factors in surface sediments of river systems in Eastern China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:19440-19449. [PMID: 27380184 DOI: 10.1007/s11356-016-7079-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 06/13/2016] [Indexed: 06/06/2023]
Abstract
Phosphorus (P) is an essential nutrient for aquatic organisms. However, too much P discharged into limnetic ecosystems can induce eutrophication. The concentration of P in freshwater ecosystems has escalated in Eastern China due to overuse of fertilizer and excess emission of sewage, which is the result of the development of industry and agriculture in this area. However, little is known about the P characteristics and its environmental factors in river systems. Here, we present the results of P characterization and its relationships with environmental factors in Eastern China by applying SMT and (31)P-NMR methods. The results showed that the concentrations of P in surface sediments varied with the river system, and more than 50 % of the samples had P concentrations exceeding 500 mg kg(-1). HCl-Pi was the dominant Pi in surface sediments, with the highest percentage (96.5 %) in the Yellow River System. Mono-P was the dominant Po in river sediments, followed by DNA-P. The PCA approach indicated that NaOH-Pi and ortho-P clustered in one group, with a second group including mono-P, diesters-P, and HCl-Pi. Phon-P and pyro-P belonged to different groups. On a regional scale, NaOH-Pi and Po showed a negative relationship with pH in sediments. Continuous eutrophication was induced by the presence of dams, and oxygen-consuming pollutants, such as NH3-N and CODcr, even when external P input was cut in heavily polluted rivers. The research revealed the characteristics of P in different river systems and proposed a conceptual model of P biogeochemical cycles in heavily polluted rivers. Results from this study may provide insight into P characteristics in Eastern China and would set a scientific basis for effective P management in developing countries.
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Affiliation(s)
- Wenqiang Zhang
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Science, Beijing, 100085, People's Republic of China
| | - Xin Jin
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Science, Beijing, 100085, People's Republic of China
- University of Chinese Academy of Science, Beijing, 100049, People's Republic of China
| | - Xiaolei Zhu
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Science, Beijing, 100085, People's Republic of China
- University of Chinese Academy of Science, Beijing, 100049, People's Republic of China
| | - Baoqing Shan
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Science, Beijing, 100085, People's Republic of China.
| | - Yu Zhao
- State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Science, Chinese Academy of Science, Beijing, 100085, People's Republic of China
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Guo Q, Yang K, Yu J, Wang C, Wen X, Zhang L, Yang M, Xia P, Zhang D. Simultaneous removal of multiple odorants from source water suffering from septic and musty odors: Verification in a full-scale water treatment plant with ozonation. WATER RESEARCH 2016; 100:1-6. [PMID: 27173729 DOI: 10.1016/j.watres.2016.05.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Revised: 05/01/2016] [Accepted: 05/04/2016] [Indexed: 06/05/2023]
Abstract
Ozonation is known to be very effective in the removal of odorants from source water. However, it is not known if ozonation is effective in the removal of multiple odorants causing different types of odors. In this study, the removal performance for odors and odorants were evaluated in a Water Treatment Plant (WTP), which was equipped with coagulation, sedimentation, ozonation, biological activated carbon (BAC) filtration, sand filtration, and chlorination in succession and located in the downstream of the Huangpu (HP) River, over the period from April, 2014 to April, 2015. Flavor profile analysis (FPA) results showed that the source water was constantly associated with septic and musty odors. Geosmin and 2-MIB, with an average OAV of 4.54 and 1.38, respectively, were the major odorants for musty odor, while bis(2-chloroisopropyl) ether, DEDS and DMDS with an average OAV of 2.35, 1.65 and 0.78, respectively, might be responsible for the septic odor. While the musty odor could be removed effectively through the combination of ozonation and BAC, the septic odor and associated odorants required further treatment with sand filtration and chlorination for complete removal. It is clear that the advanced treatment process was effective for the treatment of source water containing complicated odorants. It should be noted that the sedimentation process needs careful management because release of odorants may occur during the treatment. The result of this study will be helpful for the mitigation of odors in WTP using source waters suffering from complicated odor problems.
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Affiliation(s)
- Qingyuan Guo
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Kai Yang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Jianwei Yu
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Chunmiao Wang
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Xiaodong Wen
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, 100085, China
| | - Liping Zhang
- School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, 100085, China
| | - Min Yang
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Ping Xia
- Shanghai National Engineering Research Center of Urban Water Resources Co., Ltd., Shanghai, 200082, China
| | - Dong Zhang
- Shanghai National Engineering Research Center of Urban Water Resources Co., Ltd., Shanghai, 200082, China
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