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Cao L, Qiu Y, Xue L, Zhang Y, Zhang S, Wu N, Yuan D, Li Q, Zhao Z, Wang N, Zhou Y, Yang W, Li C, Liu Y. Sea surface carbon dioxide during early summer at the Tuandao nearshore time series site. MARINE ENVIRONMENTAL RESEARCH 2024; 201:106699. [PMID: 39178709 DOI: 10.1016/j.marenvres.2024.106699] [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: 12/29/2023] [Revised: 08/14/2024] [Accepted: 08/17/2024] [Indexed: 08/26/2024]
Abstract
To investigate air-sea CO2 flux at the Qingdao nearshore site and its temporal variations, a high-resolution continuous observation of surface carbon dioxide partial pressure (pCO2) was carried out at Zhongyuan Pier near Tuandao from May 25 to July 8, 2019. It was observed that during this period, surface pCO2 varied between ∼490 and ∼690 μatm, mainly associated with sea surface temperature. Surface pCO2 also displayed substantial diurnal variations, with an average amplitude of 64 ± 21 μatm, largely dominated by biological activities. During the observational period, this site acted as a source of atmospheric CO2, releasing 361 mmol CO2 m-2. The notable diurnal variations in air-sea CO2 flux, such as the observed average amplitude of 10.9 mmol m-2 d-1 in this study, pose a challenge for accurately estimating the air-sea CO2 flux in coastal regions without high-resolution observations.
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Affiliation(s)
- Lu Cao
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology, Qingdao, 266100, China; Ocean Observation and Exloration Research Department, Laoshan National Laboratory, Qingdao, 266200, China
| | - Yongqi Qiu
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology, Qingdao, 266100, China
| | - Liang Xue
- First Institute of Oceanography, And Key Laboratory of Marine Science and Numerical Modeling, Ministry of Natural Resources, Qingdao, 266061, China.
| | - Yingying Zhang
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology, Qingdao, 266100, China
| | - Shuwei Zhang
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology, Qingdao, 266100, China; Ocean Observation and Exloration Research Department, Laoshan National Laboratory, Qingdao, 266200, China
| | - Ning Wu
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology, Qingdao, 266100, China; Ocean Observation and Exloration Research Department, Laoshan National Laboratory, Qingdao, 266200, China
| | - Da Yuan
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology, Qingdao, 266100, China
| | - Quanlong Li
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, China
| | - Zheng Zhao
- North China Sea Marine Forecasting Center of State Oceanic Administration, Qingdao, 266061, China
| | - Ning Wang
- North China Sea Marine Forecasting Center of State Oceanic Administration, Qingdao, 266061, China
| | - Yan Zhou
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology, Qingdao, 266100, China
| | - Wei Yang
- Polar and Marine Research Institute, Jimei University, Xiamen, 361021, China
| | - Chunqian Li
- Ocean Observation and Exloration Research Department, Laoshan National Laboratory, Qingdao, 266200, China
| | - Yan Liu
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology, Qingdao, 266100, China; Ocean Observation and Exloration Research Department, Laoshan National Laboratory, Qingdao, 266200, China.
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Cao X, Xu YJ, Long G, Wu P, Liu Z. Dissolved carbon in effluent of wastewater treatment plants and its potential impacts in the receiving karst river. ENVIRONMENTAL RESEARCH 2024; 251:118570. [PMID: 38417655 DOI: 10.1016/j.envres.2024.118570] [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: 11/29/2023] [Revised: 02/20/2024] [Accepted: 02/26/2024] [Indexed: 03/01/2024]
Abstract
The dissolved carbon cycling in river system fueled by wastewater treatment plant effluent have been a research hotspot. However, the composition of dissolved carbon (DC) in wastewater effluents from karst regions remains poorly understood, resulting in a lack of clarity regarding its impact on the dynamics of dissolved carbon in karst rivers. To address this knowledge gap, this study investigated variations of dissolved inorganic (DIC) and organic C (DOC) components in effluent in karst regions and preliminarily discussed their influence on the DC cycling in karst rivers. The results showed that bicarbonate (HCO3-) in WWTP effluents makes more than 90% of the total dissolved inorganic carbon (DIC). The partial pressure of aqueous CO2 (pCO2) of the effluent reached 14450 ± 10084μtam, and pCO2 level declined with increasing river distance from the effluent discharge, effluent acted as a strong CO2 emitter to the atmosphere. Stable carbon isotope and water chemistry evidence revealed that organic matter degradation made important contributions to the high CO2 concentrations in effluent. PHREEQC mixing simulation together with filed samples data indicated that the DIC species can be changed, and pCO2 increased in receiving karst river water after mixed with effluent. The dissolved organic carbon (DOC) of effluent contained humic-like and protein-tryptophan-like, both of them appeared important and recent autochthonous, which could interfere the distinguish the sources of DOC in receiving karst river water. Thus, these findings highlight that the effluent can be an essential factor for the changes of the karst riverine DC pool, which advance our understanding on karst riverine DC evolution under anthropogenic activities. As more than 30% of the earth surface in China, northern America, and Europe are covered by carbonate rocks, this study has relevant implications for other karst regions as it underscores the influence of WWTP effluents on the carbon cycle in karst rivers. Such information and knowledge are valuable for monitoring and managing effluent-receiving river in other karst regions in the world.
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Affiliation(s)
- Xingxing Cao
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang 550025, China
| | - Y Jun Xu
- School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, LA, 70803, USA; Coastal Studies Institute, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Guangxi Long
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang 550025, China
| | - Pan Wu
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang 550025, China.
| | - Zhangxing Liu
- College of Resources and Environmental Engineering, Key Laboratory of Karst Georesources and Environment (Guizhou University), Ministry of Education, Guiyang 550025, China
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Li Y, Xue L, Yang X, Wei Q, Xin M, Xue M, Han C, Han P, Liu X, Zang H, Yang P, Ran X, Cao L, Cai WJ, Zhang L. Wastewater inputs reduce the CO 2 uptake by coastal oceans. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:165700. [PMID: 37495126 DOI: 10.1016/j.scitotenv.2023.165700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 07/16/2023] [Accepted: 07/19/2023] [Indexed: 07/28/2023]
Abstract
Every year a large quantity of wastewater is generated worldwide, but its influence on the carbon dioxide (CO2) uptake by coastal oceans is not well understood. Here, sea surface CO2 partial pressure (pCO2) and air-sea CO2 flux were examined in the Jiaozhou Bay (JZB), a temperate coastal bay strongly disturbed by wastewater inputs. Monthly surveys from April 2014 through March 2015 showed that surface pCO2 in the JZB substantially varied both temporally and spatially between 163 μatm and 1222 μatm, with an annual average of 573 μatm. During April-December, surface pCO2 was oversaturated with respect to the atmosphere, with high values exceeding 1000 μatm in the northeastern part of the bay, where seawater salinity was low mainly due to the inputs of wastewater with salinity close to zero. During January-March, surface pCO2 was undersaturated, with the lowest value of <200 μatm also mainly in the northeastern part because of low water temperature and strong biological production. Over an annual cycle, apparently sea surface temperature dominated the monthly variation of surface pCO2 in this shallow bay, while wastewater inputs and related biological production/respiration dominated its spatial variability. Overall, the JZB was a net CO2 source to the atmosphere, emitting 9.6 ± 10.8 mmol C m-2 d-1, unlike its adjacent western part of the Yellow Sea and most of the temperate coastal oceans which are a net CO2 sink. This was possibly associated with wastewater inputs that cause high sea surface pCO2 via direct inputs of CO2 and degradation of organic matter. Thus, from this viewpoint reducing wastewater discharge or lowering CO2 levels in discharged wastewater may be important paths to enhancing the CO2 uptake by coastal oceans in the future.
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Affiliation(s)
- Yunxiao Li
- Environmental Science Laboratory, College of Resource and Environment, Shanxi Agricultural University, Taigu 030801, China
| | - Liang Xue
- First Institute of Oceanography, and Key Laboratory of Marine Science and Numerical Modeling, Ministry of Natural Resources, Qingdao 266061, China.
| | - Xufeng Yang
- Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
| | - Qinsheng Wei
- First Institute of Oceanography, and Key Laboratory of Marine Science and Numerical Modeling, Ministry of Natural Resources, Qingdao 266061, China
| | - Ming Xin
- First Institute of Oceanography, and Key Laboratory of Marine Science and Numerical Modeling, Ministry of Natural Resources, Qingdao 266061, China
| | - Ming Xue
- State Key Laboratory of Petroleum Pollution Control, CNPC Research Institute of Safety and Environmental Technology, Beijing 102206, China
| | - Chenhua Han
- Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
| | - Ping Han
- Department of Environmental Engineering, Shandong Urban Construction Vocational College, Jinan 250103, China
| | - Xiangyu Liu
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Han Zang
- College of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Pengjin Yang
- North China Sea Environmental Monitoring Center, State Oceanic Administration, Qingdao 266033, China
| | - Xiangbin Ran
- First Institute of Oceanography, and Key Laboratory of Marine Science and Numerical Modeling, Ministry of Natural Resources, Qingdao 266061, China
| | - Lu Cao
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Techno1ogy, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao, China; R & D Center for Marine Instruments and Apparatuses, Qingdao Marine Science and Technology Center, Qingdao, China
| | - Wei-Jun Cai
- School of Marine Science and Policy, University of Delaware, Newark, DE, USA
| | - Longjun Zhang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
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Spatial Variation in Aragonite Saturation State and the Influencing Factors in Jiaozhou Bay, China. WATER 2020. [DOI: 10.3390/w12030825] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Both natural processes and human activities affect seawater calcium carbonate saturation state (Ωarag), while the mechanisms are still far from being clearly understood. This study analysed the seawater surface Ωarag during summer and winter in Jiaozhou Bay (JZB), China, based on two cruises observations performed in January and June 2017. The ranges of Ωarag values were 1.55~2.92 in summer and 1.62~2.15 in winter. Regression analyses were conducted to identify the drivers of the change of Ωarag distribution, and then the relative contributions of temperature, mixing processes and biological processes to the spatial differences in Ωarag were evaluated by introducing the difference between total alkalinity (TA) and dissolved inorganic carbon (DIC) as a proxy for Ωarag. The results showed that biological processes were the main factor affecting the spatial differences in Ωarag, with relative contributions of 70% in summer and 50% in winter. The contributions of temperature (25% in summer and 20% in winter) and the mixing processes (5% in summer and 30% in winter) were lower. The increasing urbanization in offshore areas can further worsen acidification, therefore environmental protection in both offshore and onshore is needed.
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