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Cai R, Yao P, Yi Y, Merder J, Li P, He D. The Hunt for Chemical Dark Matter across a River-to-Ocean Continuum. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11988-11997. [PMID: 38875444 DOI: 10.1021/acs.est.4c00648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2024]
Abstract
Thousands of mass peaks emerge during molecular characterization of natural dissolved organic matter (DOM) using ultrahigh-resolution mass spectrometry. While mass peaks assigned to certain molecular formulas have been extensively studied, the uncharacterized mass peaks that represent a significant fraction of organic matter and convey biogenic elements and energy have been previously ignored. In this study, we introduce the term dark DOM (DDOM) for unassigned mass peaks and have explored its characteristics and environmental behaviors using a data set of 38 DOM extracts covering the Yangtze River-to-ocean continuum. We identified a total of 9141 DDOM molecules, which exhibited higher molecular weight and greater diversity than the DOM subset with assigned DOM formulas. Although DDOM contributed a smaller fraction of relative abundance, it significantly impacted the molecular weight and molecular composition of bulk DOM. A portion of DDOM with higher molecular weight was found to increase molecular abundance across the river-to-ocean continuum. These compounds could contain halogenated organic molecules and might have a high potential to contribute to the refractory organic carbon pool. With this study, we underline the contribution of dark matter to the total DOM pool and emphasize that more DDOM research is needed to understand its contribution to global biogeochemical cycles and carbon sequestration.
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Affiliation(s)
- Ruanhong Cai
- Department of Ocean Science, Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Kowloon 999077, Hong Kong SAR, China
| | - Piao Yao
- Department of Ocean Science, Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Kowloon 999077, Hong Kong SAR, China
| | - Yuanbi Yi
- Department of Ocean Science, Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Kowloon 999077, Hong Kong SAR, China
| | - Julian Merder
- Department of Global Ecology, Carnegie Institution for Science, Stanford, California 94305, United States
| | - Penghui Li
- School of Marine Sciences, Sun Yat-Sen University, Zhuhai 519082, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Ding He
- Department of Ocean Science, Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Kowloon 999077, Hong Kong SAR, China
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Tat Chee Avenue, Kowloon 999077, Hong Kong SAR, China
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Jiao N, Luo T, Chen Q, Zhao Z, Xiao X, Liu J, Jian Z, Xie S, Thomas H, Herndl GJ, Benner R, Gonsior M, Chen F, Cai WJ, Robinson C. The microbial carbon pump and climate change. Nat Rev Microbiol 2024; 22:408-419. [PMID: 38491185 DOI: 10.1038/s41579-024-01018-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2024] [Indexed: 03/18/2024]
Abstract
The ocean has been a regulator of climate change throughout the history of Earth. One key mechanism is the mediation of the carbon reservoir by refractory dissolved organic carbon (RDOC), which can either be stored in the water column for centuries or released back into the atmosphere as CO2 depending on the conditions. The RDOC is produced through a myriad of microbial metabolic and ecological processes known as the microbial carbon pump (MCP). Here, we review recent research advances in processes related to the MCP, including the distribution patterns and molecular composition of RDOC, links between the complexity of RDOC compounds and microbial diversity, MCP-driven carbon cycles across time and space, and responses of the MCP to a changing climate. We identify knowledge gaps and future research directions in the role of the MCP, particularly as a key component in integrated approaches combining the mechanisms of the biological and abiotic carbon pumps for ocean negative carbon emissions.
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Affiliation(s)
- Nianzhi Jiao
- Innovation Research Center for Carbon Neutralization, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China.
- UN Global ONCE joint focal points at Shandong University, University of East Anglia, University of Maryland Center for Environmental Science, and Xiamen University, Xiamen, China.
| | - Tingwei Luo
- Innovation Research Center for Carbon Neutralization, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
- UN Global ONCE joint focal points at Shandong University, University of East Anglia, University of Maryland Center for Environmental Science, and Xiamen University, Xiamen, China
| | - Quanrui Chen
- Innovation Research Center for Carbon Neutralization, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
- UN Global ONCE joint focal points at Shandong University, University of East Anglia, University of Maryland Center for Environmental Science, and Xiamen University, Xiamen, China
| | - Zhao Zhao
- Innovation Research Center for Carbon Neutralization, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
- UN Global ONCE joint focal points at Shandong University, University of East Anglia, University of Maryland Center for Environmental Science, and Xiamen University, Xiamen, China
| | - Xilin Xiao
- Innovation Research Center for Carbon Neutralization, Fujian Key Laboratory of Marine Carbon Sequestration, Xiamen University, Xiamen, China
- UN Global ONCE joint focal points at Shandong University, University of East Anglia, University of Maryland Center for Environmental Science, and Xiamen University, Xiamen, China
| | - Jihua Liu
- UN Global ONCE joint focal points at Shandong University, University of East Anglia, University of Maryland Center for Environmental Science, and Xiamen University, Xiamen, China
- Institute of Marine Science and Technology, Shandong University, Qingdao, China
| | - Zhimin Jian
- State Key Laboratory of Marine Geology, Tongji University, Shanghai, China
| | - Shucheng Xie
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Helmuth Thomas
- Institute of Carbon Cycles, Helmholtz-Zentrum Hereon, Geesthacht, Germany
- Institut für Chemie und Biologie des Meeres (ICBM), Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Gerhard J Herndl
- Department of Functional and Evolutionary Ecology, University of Vienna, Vienna, Austria
| | - Ronald Benner
- Department of Biological Sciences, School of the Earth, Ocean and Environment, University of South Carolina, Columbia, SC, USA
| | - Micheal Gonsior
- UN Global ONCE joint focal points at Shandong University, University of East Anglia, University of Maryland Center for Environmental Science, and Xiamen University, Xiamen, China
- Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD, USA
| | - Feng Chen
- UN Global ONCE joint focal points at Shandong University, University of East Anglia, University of Maryland Center for Environmental Science, and Xiamen University, Xiamen, China
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD, USA
| | - Wei-Jun Cai
- School of Marine Science and Policy, University of Delaware, Newark, DE, USA
| | - Carol Robinson
- UN Global ONCE joint focal points at Shandong University, University of East Anglia, University of Maryland Center for Environmental Science, and Xiamen University, Xiamen, China.
- Centre for Ocean and Atmospheric Sciences (COAS), School of Environmental Sciences, University of East Anglia, Norwich, UK.
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Zhang R, Zhang Z, Chen X, Jiang J, Hua L, Jia X, Bao R, Wang F. Pyrogenic Carbon Degradation by Galvanic Coupling with Sprayed Seawater Microdroplets. J Am Chem Soc 2024; 146:8528-8535. [PMID: 38497738 DOI: 10.1021/jacs.4c00290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Surface waves are known for their mechanical role in coastal processes that influence the weather and climate. However, their chemical impact, particularly on the transformation of pyrogenic carbon, is poorly understood. Pyrogenic carbon is generally assumed to show negligible postformational alteration of its stable carbon isotope composition. Here we present an electrochemical interaction of pyrogenic carbon with the sprayed seawater microdroplets resulting from wave breaking, driven by the galvanic coupling between the microdroplet water-carbon interfaces and the microdroplet water-vapor interfaces. This enables refractory pyrogenic carbon to rapidly degrade via the oxygenation and mineralization reaction, which makes it ∼2.6‰ enriched in 13C, far exceeding the generally assumed postformation alteration values (<0.5‰) of pyrogenic carbon. The unique chemical dynamics of seawater microdroplets provide new insights into the discrepancy in carbon isotope signatures between riverine and marine black carbon, emphasizing the potential of coastal oceans for carbon sequestration in the global carbon cycle.
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Affiliation(s)
- Ruolan Zhang
- Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou 450000, P. R. China
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Zhenyuan Zhang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xuke Chen
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jichun Jiang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Lei Hua
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Xiuquan Jia
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Rui Bao
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Marine Chemistry Theory and Technology, Ocean University of China, Qingdao 266100, P. R. China
| | - Feng Wang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Coppola AI, Druffel ERM, Broek TA, Haghipour N, Eglinton TI, McCarthy M, Walker BD. Variable aging and storage of dissolved black carbon in the ocean. Proc Natl Acad Sci U S A 2024; 121:e2305030121. [PMID: 38517975 PMCID: PMC10990100 DOI: 10.1073/pnas.2305030121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 02/13/2024] [Indexed: 03/24/2024] Open
Abstract
During wildfires and fossil fuel combustion, biomass is converted to black carbon (BC) via incomplete combustion. BC enters the ocean by rivers and atmospheric deposition contributing to the marine dissolved organic carbon (DOC) pool. The fate of BC is considered to reside in the marine DOC pool, where the oldest BC 14C ages have been measured (>20,000 14C y), implying long-term storage. DOC is the largest exchangeable pool of organic carbon in the oceans, yet most DOC (>80%) remains molecularly uncharacterized. Here, we report 14C measurements on size-fractionated dissolved BC (DBC) obtained using benzene polycarboxylic acids as molecular tracers to constrain the sources and cycling of DBC and its contributions to refractory DOC (RDOC) in a site in the North Pacific Ocean. Our results reveal that the cycling of DBC is more dynamic and heterogeneous than previously believed though it does not comprise a single, uniformly "old" 14C age. Instead, both semilabile and refractory DBC components are distributed among size fractions of DOC. We report that DBC cycles within DOC as a component of RDOC, exhibiting turnover in the ocean on millennia timescales. DBC within the low-molecular-weight DOC pool is large, environmentally persistent and constitutes the size fraction that is responsible for long-term DBC storage. We speculate that sea surface processes, including bacterial remineralization (via the coupling of photooxidation of surface DBC and bacterial co-metabolism), sorption onto sinking particles and surface photochemical oxidation, modify DBC composition and turnover, ultimately controlling the fate of DBC and RDOC in the ocean.
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Affiliation(s)
- Alysha I. Coppola
- Department of Earth Sciences, Geological Institute, ETH Zürich, Zürich8092, Switzerland
| | - Ellen R. M. Druffel
- Department of Earth System Science, University of California, Irvine, CA92697
| | - Taylor A. Broek
- Geology and Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, MA02543
| | - Negar Haghipour
- Department of Earth Sciences, Geological Institute, ETH Zürich, Zürich8092, Switzerland
- Laboratory of Ion Beam Physics, ETH Zürich, Zürich8093, Switzerland
| | - Timothy I. Eglinton
- Department of Earth Sciences, Geological Institute, ETH Zürich, Zürich8092, Switzerland
| | - Matthew McCarthy
- Department of Ocean Science, University of California, Santa Cruz, CA95064
| | - Brett D. Walker
- Department of Earth System Science, University of California, Irvine, CA92697
- Department of Earth and Environmental Sciences, University of Ottawa, Ottawa, ONK1N 6N5, Canada
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Xie J, Chen C, Luo M, Peng X, Lin T, Chen D. Hidden dangers: High levels of organic pollutants in hadal trenches. WATER RESEARCH 2024; 251:121126. [PMID: 38237461 DOI: 10.1016/j.watres.2024.121126] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/05/2024] [Accepted: 01/08/2024] [Indexed: 02/12/2024]
Abstract
The "V"-shaped structure of hadal trenches acts as a natural collector of organic pollutants, drawing attention to the need for extensive research in these areas. Our review identifies significant concentrations of organic pollutants, including persistent organic pollutants, black carbon, antibiotic-resistant genes, and plastics, which often match those in industrialized regions. They may trace back to both human activities and natural sources, underscoring the trenches' critical role in ocean biogeochemical cycles. We highlight the complex lateral and vertical transport mechanisms within these zones. Advanced methodologies, including stable isotope analysis, biomarker identification, and chiral analysis within isotope-based mixing models, are crucial for discerning the origins and pathways of these pollutants. In forthcoming studies, we aim to explore advanced methods for precise pollutant tracing, develop predictive models to forecast the future distribution and impacts of pollutants in hadal zones and on the Earth's larger ecological systems.
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Affiliation(s)
- Jingqian Xie
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
| | - Chuchu Chen
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Min Luo
- College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Xiaotong Peng
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
| | - Tian Lin
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China
| | - Duofu Chen
- College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
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Vaezzadeh V, Zhong G, Zhang G. Benzene polycarboxylic acids as molecular markers of black carbon: Progresses and challenges. CHEMOSPHERE 2023; 341:140112. [PMID: 37689153 DOI: 10.1016/j.chemosphere.2023.140112] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/29/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023]
Abstract
Black carbon (BC) is generated as a result of the pyrolysis of biomass and fossil fuels. Different approaches have been taken to analyse BC in the environment, including thermal, optical and chemical methods. The chemical approach which uses benzene polycarboxylic acids (BPCAs) as molecular markers of BC has gained popularity within the scientific community recently. These pyrogenic molecular markers can be used to reconstruct ancient fire history and human presence. Here we review the development of the BPCA protocols for the analysis of BC and the previous studies that have used these methods. Additionally, this review explores the biogeochemical factors that influence the content and composition of BPCAs, which in turn affect the sources attributed to BC. These factors include the generation temperature of char, photodegradation, biodegradation and the interference of non-pyrogenic organic matter (OM) in BPCA-BC analysis. Different combustion temperatures can yield charred BC with varying degrees of aromatic condensation throughout the BC continuum, while aged soot-BC undergoes photochemical degradation, causing the loss of its original condensed aromatic structure. Photodegradation reduces the degree of BC condensation by preferentially breaking down the most condensed forms, whereas biodegradation primarily mineralizes the smaller and more biolabile BC. Non-pyrogenic sources, such as humic acids (HAs), have been found to contribute up to 25% of BPCA-BC in soil, and their presence can lead to overestimations of BC. Future research should focus on calibrating contemporary BPCA protocols using known reference materials and investigating the role of non-pyrogenic OM in BPCA-BC analysis.
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Affiliation(s)
- Vahab Vaezzadeh
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China.
| | - Guangcai Zhong
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China.
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China; CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China.
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