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Jalaluddin FM, Ahmerkamp S, Marchant HK, Meyer V, Koren K, Kuypers MMM. Microenvironments on individual sand grains enhance nitrogen loss in coastal sediments. Sci Rep 2025; 15:16384. [PMID: 40350486 PMCID: PMC12066709 DOI: 10.1038/s41598-025-00755-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2025] [Accepted: 04/30/2025] [Indexed: 05/14/2025] Open
Abstract
The permeable silicate sediments which cover more than 50% of the continental shelves are a major, but poorly constrained sink for the vast amount of anthropogenic nitrogen (N) that enters the ocean. Surface-attached microbial communities on sand grains remove fixed-N via denitrification, a process generally restricted to anoxic or low oxygen (O2) environments. Yet, in sands, denitrification also occurs in the centimeters thick well-oxygenated surface layer, which leads to additional and substantial N-loss. So far however, the underlying mechanisms that drive denitrification in oxic sands are poorly resolved. In this study, we applied a non-invasive microfluidic technique to visualize and quantify how sediment-attached microorganisms shape O2 availability on the surface of silicate sand grains. This revealed a remarkable heterogeneity in rates; with colonies of O2 consuming and producing microorganisms situated within micrometers of each other. Using a mechanistic approach to model respiration on the surface of a single silicate sand grain we showed that the high rates of O2 consumption within the microbial colonies on the sand-grain surface outpace O2 supply from the surrounding pore water. As a result anoxic microenvironments develop on the sand grain surface, which so far have been invisible to conventional techniques. The model results indicate that anaerobic denitrification occurring in these anoxic microenvironments can account for up to 74% of denitrification in oxygenated sands, with the remainder occurring in the presence of oxygen. In a preliminary upscaling approach, using a global dataset we estimated that anoxic microenvironments in oxygenated surface layers could be responsible for up to a third of the total N-loss that occurs in silicate shelf sands. Consequently, denitrification in anoxic microenvironments drives substantial anthropogenic-N removal from continental silicate shelf sands.
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Affiliation(s)
| | - Soeren Ahmerkamp
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany.
- Leibniz Institute for Baltic Sea Research Warnemünde, 18119, Rostock, Germany.
| | - Hannah K Marchant
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany
- MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359, Bremen, Germany
| | - Volker Meyer
- Max Planck Institute for Marine Microbiology, 28359, Bremen, Germany
| | - Klaus Koren
- Department of Biology, Aarhus University Centre for Water Technology, Aarhus University, Aarhus, 8000, Denmark
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Jiang S, Deng X, Ma L, Wang H, Wang X, Feng L, Zhu F, Xue S, Mohammad A. Standardized framework for assessing soil quality at antimony smelting site by considering microbial-induced resilience and heavy metal contamination. J Environ Sci (China) 2025; 148:306-320. [PMID: 39095167 DOI: 10.1016/j.jes.2023.12.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/23/2023] [Accepted: 12/26/2023] [Indexed: 08/04/2024]
Abstract
Antimony smelting activities damage the soil and vegetation surroundings while generating economic value. However, no standardized methods are available to diagnose the extent of soil degradation at antimony smelting sites. This study developed a standardized framework for assessing soil quality by considering microbial-induced resilience and heavy metal contamination at Xikuangshan antimony smelting site. The soil resilience index (SRI) and soil contamination index (SCI) were calculated by Minimum Data Set and geo-accumulation model, respectively. After standardized by a multi-criteria quantitative procedure of modified Nemerow's pollution index (NPI), the integrated assessment of soil quality index (SQI), which is the minimum of SRINPI and SCINPI, was achieved. The results showed that Sb and As were the prominent metal(loid) pollutants, and significant correlations between SQI and SRI indicated that the poor soil quality was mainly caused by the low level of soil resilience. The primary limiting factors of SRI were Fungi in high and middle contaminated areas, and Skermanella in low contaminated area, suggesting that the weak soil resilience was caused by low specific microbial abundances. Microbial regulation and phytoremediation are greatly required to improve the soil quality at antimony smelting sites from the perspectives of pollution control and resilience improvement. This study improves our understanding of ecological effects of antimony smelting sites and provides a theoretical basis for ecological restoration and sustainable development of mining areas.
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Affiliation(s)
- Shasha Jiang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Xiaoyu Deng
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Liyuan Ma
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; School of Engineering, Cardiff University, Cardiff CF243AA, United Kingdom.
| | - Hongmei Wang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Xingjie Wang
- School of Engineering, Cardiff University, Cardiff CF243AA, United Kingdom; Institute of Geological Survey, China University of Geosciences, Wuhan 430074, China
| | - Liang Feng
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Feng Zhu
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Shengguo Xue
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Arif Mohammad
- School of Engineering, Cardiff University, Cardiff CF243AA, United Kingdom
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Jiang H, Yi Z, Chen Y, Li Y, Chen L, Wang J, Nie Y, Luo M, Wang Q, Zhang W, Wu Y, Zeng G. Unraveling the mechanisms of post-treatment to enhance humification and Cd remediation in compost through EDTA-Fenton-Like systems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2025; 959:178236. [PMID: 39729843 DOI: 10.1016/j.scitotenv.2024.178236] [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: 07/24/2024] [Revised: 09/12/2024] [Accepted: 12/19/2024] [Indexed: 12/29/2024]
Abstract
This study aimed to enhance humification and cadmium (Cd) remediation in compost by investigating the effects of three post-treatments: ultrapure water, citric acid, and ethylenediaminetetraacetic acid disodium (EDTA). The results revealed that the EDTA post-treatment significantly enhanced humification by facilitating an EDTA-Fenton-like system within compost comprising rice straw and river sediment to remediate Cd-contaminated sediment. EDTA post-treatment not only promoted humic substances and humic acid concentrations of up to 66.30 g/kg and 30.40 g/kg, respectively, but also led to a reduction in the Cd content and bioavailability factor by 75.02 % and 9.76 %, respectively. In addition, parallel factor analysis revealed two distinct components, while two-dimensional correlation spectroscopy showed that the polysaccharides and carboxyl groups in humic acid were preferentially bound to Cd. Overall, this study proposes a promising approach for enhancing humification and Cd remediation in compost by the EDTA post-treatment.
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Affiliation(s)
- Hongjuan Jiang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Zhigang Yi
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Yaoning Chen
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
| | - Yuanping Li
- School of Municipal and Geomatics Engineering, Hunan City University, Yiyang, Hunan 413000, China.
| | - Li Chen
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Jun Wang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Yaoqin Nie
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Mengwei Luo
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Qianruyu Wang
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China
| | - Wei Zhang
- School of Municipal and Geomatics Engineering, Hunan City University, Yiyang, Hunan 413000, China
| | - Yanting Wu
- School of Municipal and Geomatics Engineering, Hunan City University, Yiyang, Hunan 413000, China
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, China.
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Cui S, Wang R, Chen Q, Pugliese L, Wu S. Geobatteries in environmental biogeochemistry: Electron transfer and utilization. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 22:100446. [PMID: 39104555 PMCID: PMC11298864 DOI: 10.1016/j.ese.2024.100446] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 06/29/2024] [Accepted: 06/30/2024] [Indexed: 08/07/2024]
Abstract
The efficiency of direct electron flow from electron donors to electron acceptors in redox reactions is significantly influenced by the spatial separation of these components. Geobatteries, a class of redox-active substances naturally present in soil-water systems, act as electron reservoirs, reversibly donating, storing, and accepting electrons. This capability allows the temporal and spatial decoupling of redox half-reactions, providing a flexible electron transfer mechanism. In this review, we systematically examine the critical role of geobatteries in influencing electron transfer and utilization in environmental biogeochemical processes. Typical redox-active centers within geobatteries, such as quinone-like moieties, nitrogen- and sulfur-containing groups, and variable-valent metals, possess the potential to repeatedly charge and discharge. Various characterization techniques, ranging from qualitative methods like elemental analysis, imaging, and spectroscopy, to quantitative techniques such as chemical, spectroscopic, and electrochemical methods, have been developed to evaluate this reversible electron transfer capacity. Additionally, current research on the ecological and environmental significance of geobatteries extends beyond natural soil-water systems (e.g., soil carbon cycle) to engineered systems such as water treatment (e.g., nitrogen removal) and waste management (e.g., anaerobic digestion). Despite these advancements, challenges such as the complexity of environmental systems, difficulties in accurately quantifying electron exchange capacity, and scaling-up issues must be addressed to fully unlock their potential. This review underscores both the promise and challenges associated with geobatteries in responding to environmental issues, such as climate change and pollutant transformation.
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Affiliation(s)
- Shihao Cui
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830, Tjele, Denmark
| | - Rui Wang
- Department of Biological and Chemical Engineering, Aarhus University, Gustav Wieds Vej 10, 8000, Aarhus, Denmark
| | - Qing Chen
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China
| | - Lorenzo Pugliese
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830, Tjele, Denmark
| | - Shubiao Wu
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830, Tjele, Denmark
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Zhou Z, Waska H, Henkel S, Dittmar T, Kasten S, Holtappels M. Iron Promotes the Retention of Terrigenous Dissolved Organic Matter in Subtidal Permeable Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:6204-6214. [PMID: 38557085 PMCID: PMC11008242 DOI: 10.1021/acs.est.3c09531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 04/04/2024]
Abstract
Marine permeable sediments are important sites for organic matter turnover in the coastal ocean. However, little is known about their role in trapping dissolved organic matter (DOM). Here, we examined DOM abundance and molecular compositions (9804 formulas identified) in subtidal permeable sediments along a near- to offshore gradient in the German North Sea. With the salinity increasing from 30.1 to 34.6 PSU, the DOM composition in bottom water shifts from relatively higher abundances of aromatic compounds to more highly unsaturated compounds. In the bulk sediment, DOM leached by ultrapure water (UPW) from the solid phase is 54 ± 20 times more abundant than DOM in porewater, with higher H/C ratios and a more terrigenous signature. With 0.5 M HCl, the amount of leached DOM (enriched in aromatic and oxygen-rich compounds) is doubled compared to UPW, mainly due to the dissolution of poorly crystalline Fe phases (e.g., ferrihydrite and Fe monosulfides). This suggests that poorly crystalline Fe phases promote DOM retention in permeable sediments, preferentially terrigenous, and aromatic fractions. Given the intense filtration of seawater through the permeable sediments, we posit that Fe can serve as an important intermediate storage for terrigenous organic matter and potentially accelerate organic matter burial in the coastal ocean.
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Affiliation(s)
- Zhe Zhou
- Alfred
Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 27570, Germany
- State
Key Laboratory of Marine Geology, Tongji
University, Shanghai 200092, China
| | - Hannelore Waska
- Institute
for Chemistry and Biology of the Marine Environment (ICBM), School
of Mathematics and Science, Carl von Ossietzky
Universität Oldenburg, Oldenburg 26129, Germany
| | - Susann Henkel
- Alfred
Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 27570, Germany
| | - Thorsten Dittmar
- Institute
for Chemistry and Biology of the Marine Environment (ICBM), School
of Mathematics and Science, Carl von Ossietzky
Universität Oldenburg, Oldenburg 26129, Germany
- Helmholtz
Institute for Functional Marine Biodiversity, University of Oldenburg, Oldenburg 26129, Germany
| | - Sabine Kasten
- Alfred
Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 27570, Germany
- MARUM
- Center for Marine Environmental Sciences, University of Bremen, Bremen 28359, Germany
- Faculty
of
Geosciences, University of Bremen, Bremen 28359, Germany
| | - Moritz Holtappels
- Alfred
Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven 27570, Germany
- MARUM
- Center for Marine Environmental Sciences, University of Bremen, Bremen 28359, Germany
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Lan Y, Gai S, Cheng K, Liu Z, Antonietti M, Yang F. Artificial Humic Acid Mediated Carbon-Iron Coupling to Promote Carbon Sequestration. RESEARCH (WASHINGTON, D.C.) 2024; 7:0308. [PMID: 38375103 PMCID: PMC10875824 DOI: 10.34133/research.0308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 01/10/2024] [Indexed: 02/21/2024]
Abstract
Fe (hydr)oxides have a substantial impact on the structure and stability of soil organic carbon (SOC) pools and also drive organic carbon turnover processes via reduction-oxidation reactions. Currently, many studies have paid much attention to organic matter-Fe mineral-microbial interactions on SOC turnover, while there is few research on how exogenous carbon addition abiotically regulates the intrinsic mechanisms of Fe-mediated organic carbon conversion. The study investigated the coupling process of artificial humic acid (A-HA) and Fe(hydr)oxide, the mechanism of inner-sphere ligands, and the capacity for carbon sequestration using transmission electron microscopy, thermogravimetric, x-ray photoelectron spectroscopy, and wet-chemical disposal. Furthermore, spherical aberration-corrected scanning transmission electron microscopy-electron energy loss spectroscopy and Mössbauer spectra have been carried out to demonstrate the spatial heterogeneity of A-HA/Fe (hydr)oxides and reveal the relationship between the increase in Fe-phase crystallinity and redox sensitivity and the accumulation of organic carbon. Additionally, the dynamics of soil structures on a microscale, distribution of carbon-iron microdomains, and the cementing-gluing effect can be observed in the constructing nonliving anthropogenic soils, confirming that the formation of stable aggregates is an effective approach to achieving organic carbon indirect protection. We propose that exogenous organic carbon inputs, specifically A-HA, could exert a substantial but hitherto unexplored effect on the geochemistry of iron-carbon turnover and sequestration in anoxic water/solid soils and sediments.
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Affiliation(s)
- Yibo Lan
- School of Water Conservancy and Civil Engineering,
Northeast Agricultural University, Harbin 150030, China
- International Cooperation Joint Laboratory of Health in Cold Region Black Soil Habitat of the Ministry of Education, Harbin 150030, China
| | - Shuang Gai
- School of Water Conservancy and Civil Engineering,
Northeast Agricultural University, Harbin 150030, China
- International Cooperation Joint Laboratory of Health in Cold Region Black Soil Habitat of the Ministry of Education, Harbin 150030, China
| | - Kui Cheng
- International Cooperation Joint Laboratory of Health in Cold Region Black Soil Habitat of the Ministry of Education, Harbin 150030, China
- College of Engineering,
Northeast Agricultural University, Harbin 150030, China
| | - Zhuqing Liu
- School of Water Conservancy and Civil Engineering,
Northeast Agricultural University, Harbin 150030, China
- International Cooperation Joint Laboratory of Health in Cold Region Black Soil Habitat of the Ministry of Education, Harbin 150030, China
| | - Markus Antonietti
- Department of Colloid Chemistry,
Max Planck Institute of Colloids and Interfaces, 14476 Potsdam, Germany
| | - Fan Yang
- School of Water Conservancy and Civil Engineering,
Northeast Agricultural University, Harbin 150030, China
- International Cooperation Joint Laboratory of Health in Cold Region Black Soil Habitat of the Ministry of Education, Harbin 150030, China
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Wang T, Yang X, Li Z, Chen W, Wen X, He Y, Ma C, Yang Z, Zhang C. MeHg production in eutrophic lakes: Focusing on the roles of algal organic matter and iron-sulfur-phosphorus dynamics. JOURNAL OF HAZARDOUS MATERIALS 2023; 457:131682. [PMID: 37270963 DOI: 10.1016/j.jhazmat.2023.131682] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/20/2023] [Accepted: 05/21/2023] [Indexed: 06/06/2023]
Abstract
The mechanisms by which eutrophication affects methylmercury (MeHg) production have not been comprehensively summarized, which hinders accurately predicting the MeHg risk in eutrophic lakes. In this review, we first discussed the effects of eutrophication on biogeochemical cycle of mercury (Hg). Special attentions were paid to the roles of algal organic matter (AOM) and iron (Fe)-sulfur (S)-phosphorus (P) dynamics in MeHg production. Finally, the suggestions for risk control of MeHg in eutrophic lakes were proposed. AOM can affect in situ Hg methylation by stimulating the abundance and activities of Hg methylating microorganisms and regulating Hg bioavailability, which are dependent on bacteria-strain and algae species, the molecular weight and composition of AOM as well as environmental conditions (e.g., light). Fe-S-P dynamics under eutrophication including sulfate reduction, FeS formation and P release could also play crucial but complicated roles in MeHg production, in which AOM may participate through influencing the dissolution and aggregation processes, structural order and surface properties of HgS nanoparticles (HgSNP). Future studies should pay more attention to the dynamics of AOM in responses to the changing environmental conditions (e.g., light penetration and redox fluctuations) and how such variations will subsequently affect MeHg production. The effects of Fe-S-P dynamics on MeHg production under eutrophication also deserve further investigations, especially the interactions between AOM and HgSNP. Remediation strategies with lower disturbance, greater stability and less cost like the technology of interfacial O2 nanobubbles are urgent to be explored. This review will deepen our understanding of the mechanisms of MeHg production in eutrophic lakes and provide theoretical guidance for its risk control.
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Affiliation(s)
- Tantan Wang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Xu Yang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Zihao Li
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Wenhao Chen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Xin Wen
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Yubo He
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Chi Ma
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Zhongzhu Yang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China
| | - Chang Zhang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, China.
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