The Environmental Functions and Ecological Effects of Organic Carbon in Silt

Li, Rui; Ma, Teng; Qiu, Wenkai; Peng, Ziqi; Shi, Chenxuan

doi:10.1007/s12583-020-1349-z

Cited by 18 publications

(2 citation statements)

References 74 publications

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“…Previous studies mainly concerned about either abiotic or biotic mechanisms for ROS production, and the relationship between the production mechanisms and the characteristics of the subsurface environment was ambiguous. − ,− Sediments from different sites, depths, and seasons vary in redox properties and also in geochemical compositions and microbial community. − In order to clarify the constraining conditions under which abiotic or biotic or biotic–abiotic mechanisms predominate for ROS production in the subsurface, we collected 10 sediments from different locations and depths of a floodplain adjacent to the Yangtze river and measured H 2 O 2 and •OH production during oxygenation of these sediments. To distinguish biotic and abiotic mechanisms, we compared H 2 O 2 and •OH production during oxygenation of nonsterilized and sterilized sediments.…”

Section: Introductionmentioning

confidence: 99%

Dependence of Biotic and Abiotic H₂O₂ and •OH Production on the Redox Conditions and Compositions of Sediment during Oxygenation

Zhang,

Liu,

Wan

et al. 2024

Environ. Sci. Technol.

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Reactive oxygen species (ROS) production in O 2perturbed subsurface environments has been increasingly documented in recent years. However, the constraining conditions under which abiotic and/or biotic mechanisms predominate for ROS production remain ambiguous. Here, we demonstrate that the ROS production mechanism, biotic and abiotic, is determined by sediment redox properties and sediment compositions. Upon the oxygenation of 10 field sediments, the cumulative H 2 O 2 concentrations reached up to 554 μmol/kg within 2 h. The autoclaving sterilization experiments showed that H 2 O 2 could be produced by both biotic and abiotic processes depending on the redox conditions. However, only the abiotic process could produce significant levels of •OH, and the production yield was closely related to the sediment components, particularly sediment Fe(II) and organic matter. Fe(II) bound with organic matter led to high yields of H 2 O 2 and •OH production. Sediment oxygenation contributed to the appearance of H 2 O 2 in groundwater, with the abiotic mechanism producing higher instantaneous H 2 O 2 concentrations than the biotic mechanism. These findings reveal that the redox conditions, compositions, and texture of sediments collectively control abiotic and biotic mechanisms for ROS production, which assists the identification of ROS production hotspots and the understanding of ROS distribution and utilization in the subsurface.

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Section: Introductionmentioning

confidence: 99%

Dependence of Biotic and Abiotic H₂O₂ and •OH Production on the Redox Conditions and Compositions of Sediment during Oxygenation

Zhang,

Liu,

Wan

et al. 2024

Environ. Sci. Technol.

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“…The intense reduction environment and high levels of organic matter (OM) regulate the reduction reaction and secondary mineral types of Fe (hydrogen) oxides in clayey aquitards [3,18,19], resulting in the release of Fe-bound elements such as arsenic [9,20]. Due to inelastic compaction and advection, anaerobic metabolites such as Fe (II), Mn (II), or dissolved organic carbon (DOC) can enter the aquifer with clay pore water, mediating the anaerobic conditions of adjacent aquifers [21]. Elevated Fe levels in groundwater can cause a variety of issues, including the unsatisfactory taste of drinking water and irrigation system blockage [22].…”

Section: Introductionmentioning

confidence: 99%

Spatial Distribution and Factors Influencing the Various Forms of Iron in Alluvial–Lacustrine Clayey Aquitard

Chen,

Liu,

Jian

et al. 2023

Water

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The compression release of pore water in clayey aquitards has a significant impact on groundwater quality. Iron is an active variable element that mediates biochemical reactions in groundwater systems, but its transformation mechanisms in clayey aquitards remain unclear. The sediment and pore water samples from the shallow clayey aquitard (thickness = ~20 m) in the Chen Lake area of China were collected in three boreholes. The spatial distribution and influencing factors of Fe occurrence in the aquitard were revealed using hierarchical extraction, statistical analysis, and simulation calculations. The results indicate that the background value of alluvial–lacustrine sediments primarily affects the Fe concentration of clayey sediments. The dissimilatory reduction in free Fe oxide was the main source of Fe ions in pore water, resulting in a major percentage of Fe2+ in the total Fe concentration (0.07−5.91 mg/L). The abundant organic matter in organic-rich clay promoted a dissimilatory reduction in Fe (III) oxides, while the Fe concentrations of sediment and pore water were lower in the sand-rich stratum because of its weak adsorption capacity. The impact of human reclamation activities on the aquitard was mainly concentrated in the shallow layer (>−3 m), resulting in water drainage and O2 and CO2 input, which induced the crystallization of poorly crystalline Fe oxides. The input of reactive organic matter from reclaimed crops promoted the dissimilatory reduction in Fe oxides and the enrichment of Fe in deep pore water. The copious Fe2+ in deep stratum pore water tended to interact with CO32− and S2− to form coprecipitation with Fe (II). The concentrations of As, Cr, Sr, Zn, and Mn in pore water followed a similar variation trend to the Fe ion concentration, and their release could be attributed to the reduction dissolution of sediment Fe (III) oxides.

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黏土沉积物压实过程中铁的迁移与转化机制：利用模拟实验进行的研究

Liu,

Ma,

Liu

et al. 2024

Hydrogeol J

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The Environmental Functions and Ecological Effects of Organic Carbon in Silt

Cited by 18 publications

References 74 publications

Dependence of Biotic and Abiotic H₂O₂ and •OH Production on the Redox Conditions and Compositions of Sediment during Oxygenation

Dependence of Biotic and Abiotic H₂O₂ and •OH Production on the Redox Conditions and Compositions of Sediment during Oxygenation

Spatial Distribution and Factors Influencing the Various Forms of Iron in Alluvial–Lacustrine Clayey Aquitard

黏土沉积物压实过程中铁的迁移与转化机制：利用模拟实验进行的研究

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The Environmental Functions and Ecological Effects of Organic Carbon in Silt

Cited by 18 publications

References 74 publications

Dependence of Biotic and Abiotic H2O2 and •OH Production on the Redox Conditions and Compositions of Sediment during Oxygenation

Dependence of Biotic and Abiotic H2O2 and •OH Production on the Redox Conditions and Compositions of Sediment during Oxygenation

Spatial Distribution and Factors Influencing the Various Forms of Iron in Alluvial–Lacustrine Clayey Aquitard

黏土沉积物压实过程中铁的迁移与转化机制：利用模拟实验进行的研究

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Dependence of Biotic and Abiotic H₂O₂ and •OH Production on the Redox Conditions and Compositions of Sediment during Oxygenation

Dependence of Biotic and Abiotic H₂O₂ and •OH Production on the Redox Conditions and Compositions of Sediment during Oxygenation