Studies on Hydroxyl Radical Formation and Correlated Photoflocculation Process Using Degraded Wood Leachate as a CDOM Source

Sun, Luni; Mopper, Kenneth

doi:10.3389/fmars.2015.00117

Cited by 9 publications

(4 citation statements)

References 56 publications

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“…Photochemistry has also been implicated in the apparent photo‐production of condensed aromatics from non‐pyrogenic DOM (Chen et al ; Waggoner et al ) using photo‐irradiation experiments for samples with very high DOC and high iron content. Iron appears to play an important role in the cycling of DBC (Riedel et al ), and the presence of iron can induce photo‐flocculation of terrestrial DOM (Helms et al ; Sun and Mopper ). Therefore, the appearance of condensed aromatic structures in the particulate phase after photo‐irradiation of highly aromatic, high iron samples (Chen et al ) may have resulted from the photo‐flocculation of DBC already present in the water sample rather than the net production of condensed aromatic compounds.…”

Section: Degradative Processing and Environmental Sinks Of Dissolved mentioning

confidence: 99%

Dissolved black carbon in aquatic ecosystems

Wagner

Jaffé

Stubbins

2018

Limnol Oceanogr Letters

142

148

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The incomplete combustion of organic molecules produces a chemically diverse suite of pyrogenic residues termed black carbon (BC). The significance of BC cycling on land has long been recognized, and the recognition of dissolved BC (DBC) as a major component of the aquatic carbon cycle is developing rapidly. As we seek a greater understanding of DBC cycling, our interpretation of environmental DBC concentrations and molecular composition should take into account both the formation conditions of charred residues, and the physico-chemical transformation of DBC that occurs during transit within aquatic systems. We present the current state of knowledge concerning sources, processing, and sinks of DBC in inland, coastal/estuarine, and ocean waters. We feature studies and new methodologies which focus specifically on the aquatic cycling of DBC, explore the relationship between particulate and dissolved BC, and highlight research gaps which should be targeted to advance our current knowledge of DBC biogeochemistry.Fire has been an integral component of terrestrial ecosystems and biogeochemical cycles since the emergence of land plants some 420 million years ago (Bowman et al. 2009). Contemporary fire regimes are increasingly influenced by human activities, including the use of fire for agricultural practices, land management, vegetation control, and industry (Bowman et al. 2011). Black carbon (BC) is the organic residue formed during the incomplete combustion of organic matter, which occurs during both natural (wildfire) and anthropogenic (biomass burning, fossil fuel combustion) burning. Wildfires are the predominant source of BC to the environment and the vast majority of BC Scientific Significance StatementFire, both natural and anthropogenic, alters organic molecules into many chemical forms, all termed black carbon. Although well studied in soils and the atmosphere, black carbon in natural waters has only recently been identified as important. For example, 10% of dissolved organic carbon in rivers is in the form of dissolved black carbon. In this article, we present our emerging understanding of the chemistry, reactivity, fate, and ecological influence of dissolved black carbon in natural waters as well as the research challenges and opportunities.168 Limnology and Oceanography Letters 3, 2018, 168-185

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Section: Degradative Processing and Environmental Sinks Of Dissolved mentioning

confidence: 99%

Dissolved black carbon in aquatic ecosystems

Wagner

Jaffé

Stubbins

2018

Limnol Oceanogr Letters

142

148

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“…Fluorescence regional integration (FRI) is a new quantitative approach to analyze the total wavelength-independent fluorescence intensity data based on EEM spectra (Chen et al, 2003;Sun et al, 2016). EEM maps were divided into five regions, and a description of each region is provided in Table 1.…”

Section: Cdom Fluorescence Measurement and Fri Analysismentioning

confidence: 99%

Characterization of CDOM in saline and freshwater lakes across China using spectroscopic analysis

et al. 2019

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China were examined to determine relationships between lake water sources (fresh versus saline) and their fluorescence/absorption characteristics. Results indicated significant differences regarding DOC concentration and a CDOM (254) between freshwater (6.68 mg C L-1 , 19.55 m-1) and saline lakes (27.4 mg C L-1 , 41.17 m-1). While humic-like (F 5) and fulvic-like (F 3) compounds contributed to CDOM fluorescence in all lake waters significantly, their contribution to total fluorescence intensity (F T) differed between saline and freshwater lakes. Significant negative relationships were also observed between lake altitude with either F 5 (R 2 =0.63, N=306) or F T (R 2 =0.64, N=306), suggesting that the abundance of humic-like materials in CDOM tends to decrease with increased in lakes altitude. In high-altitude lakes, strong solar irradiance and UV exposure may have induced photo-oxidation reactions resulting in decreased abundance of humic-like substances and the formation of low molecular weight compounds. These findings have important implications regarding our understanding of C dynamics in lacustrine systems and the contribution of these ecosystems to the global C cycle.

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“…Several studies on dissolved organic matter have shown that Fe takes part in the photo‐flocculation process (Gao and Zepp ; Helms et al ; Sun et al ). Iron not only accelerates ROS production, such as the Fenton reaction, but can also bind to organic ligands as complexes (Chen et al ; Sun and Mopper ). Recent studies by Waggoner et al () and Chen et al () have demonstrated, through molecular level analyses, that black‐carbon like macromolecules can be formed from terrestrial dissolved organic matter in the presence of sunlight and Fe.…”

Section: Background On the Study Of Marine Snow And Oil Spillsmentioning

confidence: 99%

The role of microbial exopolymers in determining the fate of oil and chemical dispersants in the ocean

Quigg

Passow

Chin

et al. 2016

Limnol Oceanogr Letters

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The production of extracellular polymeric substances (EPS) by planktonic microbes can influence the fate of oil and chemical dispersants in the ocean through emulsification, degradation, dispersion, aggregation, and/or sedimentation. In turn, microbial community structure and function, including the production and character of EPS, is influenced by the concentration and chemical composition of oil and chemical dispersants. For example, the production of marine oil snow and its sedimentation and flocculent accumulation to the seafloor were observed on an expansive scale after the Deepwater Horizon oil spill in the Northern Gulf of Mexico in 2010, but little is known about the underlying control of these processes. Here, we review what we do know about microbially produced EPS, how oil and chemical dispersant can influence the production rate and chemical and physical properties of EPS, and ultimately the fate of oil in the water column. To improve our response to future oil spills, we need a better understanding of the biological and physiochemical controls of EPS production by microbes under a range of environmental conditions, and in this paper, we provide the key knowledge gaps that need to be filled to do so. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Scientific Significance StatementExtracellular polymeric substances (EPS) are a group of chemically heterogeneous polymers released into the environment by microbes (bacteria, archaea, and phytoplankton), often in response to environmental stresses. EPS serve an important role in determining the fate and transport of oil after a spill, but relatively little is known about EPS production in relation to oil and dispersants, especially at molecular and chemical levels. Here, we summarize the scope of our current knowledge and identify major knowledge gaps. 3Limnology and Oceanography Letters 1, 2016, 3-26

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Studies on Hydroxyl Radical Formation and Correlated Photoflocculation Process Using Degraded Wood Leachate as a CDOM Source

Cited by 9 publications

References 56 publications

Dissolved black carbon in aquatic ecosystems

Dissolved black carbon in aquatic ecosystems

Characterization of CDOM in saline and freshwater lakes across China using spectroscopic analysis

The role of microbial exopolymers in determining the fate of oil and chemical dispersants in the ocean

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