Links between size fractionation, chemical speciation of dissolved copper and chemical speciation of dissolved organic matter in the Loire estuary

2020 ◽  
Vol 17 (5) ◽  
pp. 385
Author(s):  
Gabriel Dulaquais ◽  
Matthieu Waeles ◽  
Johann Breitenstein ◽  
Joël Knoery ◽  
Ricardo Riso
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Humic Substances ◽  
Chemical Speciation ◽  
Salinity Gradient ◽  
Treatment Plant ◽  
High Concentration ◽  
Aquatic Life ◽  
Complexing Capacity ◽  
Organic Speciation

Environmental contextThe toxicity of copper to aquatic life is highly dependent on its chemical form. In the vineyards of the Loire valley, mixtures of copper compounds are increasingly being used as fungicides. Our study investigating the origin and behaviour of dissolved copper on the land-sea continuum of the Loire advances our understanding of the chemical forms and fate of copper in estuarine systems. AbstractWe present data on the organic speciation of dissolved copper (dCu) in the Loire estuary for the soluble (<0.02µm) and dissolved (<0.45µm) fractions. These results were interpreted according to the distribution of natural organic matter along the estuary. We observed a high concentration of dCu (80nmolkg−1) upstream of the tidal front (S=0.1, where S is the salinity), possibly induced by drainage from vineyards located on the watershed of the estuary, and a concentration typical of coastal seawater at the end of the salinity gradient (3–4nmolkg−1). dCu showed a non-conservative distribution along the estuary with a notably strong decrease in concentration at the very first stage of mixing (S ~ 0.5) that increased again at low salinity (S=4.7). The latter increase in the concentration of dCu was related to the supply of colloidal copper induced by particle desorption in the maximum turbidity zone. The organic speciation of dCu revealed that the complexing capacity of copper ligands (LCu, up to 147 nanomoles of Cu per kilogram of water) exceeded dCu in both the soluble and dissolved fractions, which kept the activity of cupric ions below toxic levels for most unicellular phytoplankton. Humic substances comprised up to 95% of LCu in the continental shelf sample, but their complexing capacity did not account for all of the LCu in the inner estuary. We conducted pseudopolarographic experiments and found two other additional ligand classes: thiol-like and amino-acids/proteins. While humic substances are the dominant component of dissolved organic matter (DOM), the study of DOM suggested the release of colloidal DOM from a wastewater treatment plant. This structure could be a major source of proteinaceous LCu in the system that changes the dCu speciation in the middle of the estuary.

Competitive removal of dissolved organic matter (DOM) and inorganic anions by anion exchange resins (AERs)

2012 ◽  
Vol 12 (5) ◽  
pp. 630-636 ◽  
Author(s):  
A. Phetrak ◽  
J. Lohwacharin ◽  
N. Watanabe ◽  
M. Murakami ◽  
H. Sakai ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Anion Exchange ◽  
Treatment Plant ◽  
Inorganic Anions ◽  
Order Kinetic ◽  
High Concentration ◽  
Strong Base ◽  
Anion Exchange Resins ◽  
Exchange Resins

Four strong-base anion exchange resins (AERs) with different properties were selected to investigate dissolved organic matter (DOM) removal from river water containing inorganic anions. Rapid sand-filtered water was obtained from a water treatment plant in Tokyo, Japan, and then concentrated by an ultrafiltration membrane for use in ion exchange experiments to simulate high dissolved organic carbon (DOC) and sulfate conditions. AERs removed 23–50% of DOC and 70–80% of UV254 within 30 min despite high sulfate concentration (121 mg/L). Although the materials and structure of the AERs did not affect the reduction of UV254, DOC removal was affected. The highest DOC reduction was achieved by a macroporous polyacrylic AER (Purolite), while the macroporous polystyrene IRA 910 had the lowest DOC removal. A pseudo-second-order kinetic model showed that the rate constants and the initial sorption rates of polyacrylic resins were higher than those by polystyrene resins, suggesting that more hydrophilic structure of AERs exhibited faster DOC removal. Aromatic DOM with a molecular weight (MW) of 800–3,000 Da was almost completely removed by AERs, whereas only half of aromatic DOMs smaller than 800 Da were removed by AERs. Adsorbed DOC comprised less than 6% of all exchanged anions, whereas the adsorbed sulfate was about 90% due to comparatively high concentration of sulfate in the water sample.

scholarly journals DOM degradation by light and microbes along the Yukon River-coastal ocean continuum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Brice K. Grunert ◽  
Maria Tzortziou ◽  
Patrick Neale ◽  
Alana Menendez ◽  
Peter Hernes
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Salinity Gradient ◽  
Coastal Ocean ◽  
Interactive Effects ◽  
The Arctic ◽  
Yukon River ◽  
Spring Freshet ◽  
Dom Composition

AbstractThe Arctic is experiencing rapid warming, resulting in fundamental shifts in hydrologic connectivity and carbon cycling. Dissolved organic matter (DOM) is a significant component of the Arctic and global carbon cycle, and significant perturbations to DOM cycling are expected with Arctic warming. The impact of photochemical and microbial degradation, and their interactive effects, on DOM composition and remineralization have been documented in Arctic soils and rivers. However, the role of microbes, sunlight and their interactions on Arctic DOM alteration and remineralization in the coastal ocean has not been considered, particularly during the spring freshet when DOM loads are high, photoexposure can be quite limited and residence time within river networks is low. Here, we collected DOM samples along a salinity gradient in the Yukon River delta, plume and coastal ocean during peak river discharge immediately after spring freshet and explored the role of UV exposure, microbial transformations and interactive effects on DOM quantity and composition. Our results show: (1) photochemical alteration of DOM significantly shifts processing pathways of terrestrial DOM, including increasing relative humification of DOM by microbes by > 10%; (2) microbes produce humic-like material that is not optically distinguishable from terrestrial humics; and (3) size-fractionation of the microbial community indicates a size-dependent role for DOM remineralization and humification of DOM observed through modeled PARAFAC components of fluorescent DOM, either through direct or community effects. Field observations indicate apparent conservative mixing along the salinity gradient; however, changing photochemical and microbial alteration of DOM with increasing salinity indicate changing DOM composition likely due to microbial activity. Finally, our findings show potential for rapid transformation of DOM in the coastal ocean from photochemical and microbial alteration, with microbes responsible for the majority of dissolved organic matter remineralization.

Interaction of dissolved organic matter with Hg(II) along salinity gradient in Boston Lake

2014 ◽  
Vol 52 (12) ◽  
pp. 1072-1077 ◽  
Author(s):  
Rehemanjiang Wufuer ◽  
Ying Liu ◽  
Shuyong Mu ◽  
Wenjuan Song ◽  
Xue Yang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Salinity Gradient

scholarly journals Phylogenetic and Functional Diversity of Saprolegniales and Fungi Isolated from Temperate Lakes in Northeast Germany

2021 ◽  
Vol 7 (11) ◽  
pp. 968
Author(s):  
Hossein Masigol ◽  
Jason Nicholas Woodhouse ◽  
Pieter van West ◽  
Reza Mostowfizadeh-Ghalamfarsa ◽  
Keilor Rojas-Jimenez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Enzymatic Activity ◽  
Humic Substances ◽  
Plant Litter ◽  
Freshwater Ecosystems ◽  
Chitinolytic Activity ◽  
Ecological Implications ◽  
Eukaryotic Organisms

The contribution of fungi to the degradation of plant litter and transformation of dissolved organic matter (humic substances, in particular) in freshwater ecosystems has received increasing attention recently. However, the role of Saprolegniales as one of the most common eukaryotic organisms is rarely studied. In this study, we isolated and phylogenetically placed 51 fungal and 62 Saprolegniales strains from 12 German lakes. We studied the cellulo-, lignino-, and chitinolytic activity of the strains using plate assays. Furthermore, we determined the capacity of 10 selected strains to utilize 95 different labile compounds, using Biolog FF MicroPlates™. Finally, the ability of three selected strains to utilize maltose and degrade/produce humic substances was measured. Cladosporium and Penicillium were amongst the most prevalent fungal strains, while Saprolegnia, Achlya, and Leptolegnia were the most frequent Saprolegniales strains. Although the isolated strains assigned to genera were phylogenetically similar, their enzymatic activity and physiological profiling were quite diverse. Our results indicate that Saprolegniales, in contrast to fungi, lack ligninolytic activity and are not involved in the production/transformation of humic substances. We hypothesize that Saprolegniales and fungi might have complementary roles in interacting with dissolved organic matter, which has ecological implications for carbon cycling in freshwater ecosystems.

scholarly journals Effects of sulfonamide antibiotics on digestion performance and microbial community during swine manure anaerobic digestion

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Shaona Wang ◽  
Kang Du ◽  
Rongfang Yuan ◽  
Huilun Chen ◽  
Fei Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Anaerobic Digestion ◽  
Dissolved Organic Matter ◽  
Methane Production ◽  
Volatile Fatty Acids ◽  
High Throughput Sequencing ◽  
Batch Reactor ◽  
Inhibition Mechanism ◽  
Sulfonamide Antibiotics ◽  
High Concentration

The effects of four types of sulfonamide antibiotics (SAs), including sulfaquinoxaline, sulfamethoxazole, sulfamethoxydiazine and sulfathiazole, on the digestion performance during anaerobic digestion process were studied using a lab-scale anaerobic sequencing batch reactor, and the changes of the community structure in the presence of SAs were investigated with the help of high throughput sequencing. The results indicated that when SAs were added, the hydrolytic acidification process was inhibited, and the accumulation of volatile fatty acids (VFAs) was induced, resulting in the suppression of methane production. However, the inhibition mechanism of different SAs was quite different. The inhibitory effect of high concentration of SAs on the hydrolysis of solid particulate matter into dissolved organic matter followed the order of sulfaquinoxaline > sulfamethoxydiazine > sulfathiazole > sulfamethoxazole. SAs have obvious inhibitory effects on acidification and methanation of dissolved organic matter, especially sulfathiazole. The richness and the community composition of the microorganism including bacteria and archaea in the digestion system were affected by SAs. Under the effect of SAs, the relative abundance of many microorganisms is negatively correlated with methane production, among which Methanobrevibacter, a kind of Archaea, had the greatest influence on methane production.

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