Hg release and Hg nanoparticle formation upon flooding of an agriculturally used fluvisol.

2020 ◽  
Author(s):  
Lorenz Gfeller ◽  
Andrea Weber ◽  
Isabelle Worms ◽  
Vera Slaveykova ◽  
Adrien Mestrot
Keyword(s):  
Microbial Activity ◽  
Pore Water ◽  
Point Sources ◽  
Floodplain Soil ◽  
Subsequent Decrease ◽  
Icp Ms ◽  
Dynamic Diameter ◽  
Rhone Valley ◽  
Acetaldehyde Production ◽  
Mn Oxides

<p>Soils in legacy sites of chlor-alkali and acetaldehyde production are point sources of mercury (Hg) to downstream eco-systems. Flooding and agricultural activities may influence the fate of Hg by altering redox conditions, microbial activity and carbon budgets. However, the complex interplay between these parameters is still not well understood. The aim of this work was to better understand the effect of flooding and fertilisation on the release/sequestration of Hg in a polluted  floodplain soil.</p><p>We conducted a flooding-draining incubation experiment on two Hg polluted fluvisols (2.4 ± 0.1 and 44.8 ± 0.5 mg.kg<sup>-1</sup> Hg). The soils originated from an agriculturally used floodplain situated in the Rhone Valley (Valais, Switzerland) and were exposed to Hg pollution by an acetaldehyde producing plant until the 1970’s. They were incubated in triplicates for each treatment. During 56 days the soils were alternately flooded and drained in intervals of 14 days. For flooding, we used an artificial rain water and a 1:1.5 soil:water ratio. The influence of agricultural activites was studied by adding 0.6% (w/w) of liquid manure in a separate treatment. We monitored pore water Hg<sub>total</sub>, Eh, pH, DOC and relevant metals in daily time intervals. Further, the sampled pore water was filtered in distinct intervals (10µm / 5µm / 0.45µm / 0.020µm) at specific time points and analyzed for Hg<sub>total</sub>. Additionally, the 0.45µm fraction was sampled to study the evolution of colloidal Hg with AF4-ICP-MS.</p><p>We observed differences between soil treated with or without manure. In the microcosms (MCs) treated with manure, we observed a Hg<sub>total</sub> release along with reductive disolution of Mn-oxides peaking (Hg<sub>total</sub>: 20.8 µg.L<sup>-1</sup>) after 5 days of flooding. Subsequently, pore water Hg<sub>total</sub> decreased with a simultanous decrease in pore water SO<sub>4</sub><sup>2-</sup>. This is likely due to the onset of sulfate reduction. Additionally, we observed the increase of inorganic colloidal Hg in the range of 10nm hydro dynamic diameter in manure treated MCs with higher contaminated soil during the first 2 and 10 days of incubation.</p><p>In the MCs without manure addition, the onset of reductive dissolution of Mn oxides was 2 days later. Pore water Hg<sub>total</sub>  peaked only after 7 days of flooding (19.76 µg.L<sup>-1 </sup>Hg) and remained at the same levels until the end of the first flooding period. This is likely due to a lower microbial activity and a lower labile carbon pool in the untreated compared to the treated soils.</p><p>Flooding of our polluted fluvisol releases Hg after few days. The additional manuring accelerates this process. However, it as well accelerates the subsequent decrease of Hg<sub>total</sub> in the pore water. This is among others due to the formation of Hg nanoparticles. We plan to use electron microscopy in order to draw conclusions about the nature of these Hg nanoparticles.</p>

scholarly journals Geochemistry of intertidal sediment pore waters from the industrialized Santos-Cubatão Estuarine System, SE Brazil

2012 ◽  
Vol 84 (2) ◽  
pp. 427-442 ◽  
Author(s):  
Winston F.O. Gonçalves ◽  
Wanilson Luiz-Silva ◽  
Wilson Machado ◽  
Erico C. Nizoli ◽  
Ricardo E. Santelli
Keyword(s):  
Surface Water ◽  
Pore Water ◽  
Surface Waters ◽  
Water Concentration ◽  
Point Sources ◽  
Intertidal Sediment ◽  
Estuarine System ◽  
Pore Waters ◽  
Geochemical Composition ◽  
Se Brazil

The geochemical composition of sediment pore water was investigated in comparison with the composition of sediment particles and surface water in an estuary within one of the most industrialized areas in Latin America (Santos-Cubatão estuarine system, SE Brazil). Pore and surface waters presented anomalously high levels of F-, NH4+, Fe, Mn and P due to two industrial point sources. In the summer, when SO4(2-)/Cl- ratios suggested an enhanced sulfate reduction, the higher dissolved levels observed in pore waters for some metals (e.g., Cu and Ni) were attributed to reductive dissolution of oxidized phases. Results evidenced that the risks of surface water concentration increase due to diffusion or advection from pore water are probably dependent on coupled influences of tidal pumping and groundwater inputs.

Quantification of Tl (I) and Tl (III) based on microcolumn separation through ICP-MS in river sediment pore water

2020 ◽  
Vol 27 (9) ◽  
pp. 9686-9696 ◽  
Author(s):  
Atta Rasool ◽  
Tangfu Xiao ◽  
Salar Ali ◽  
Waqar Ali ◽  
Wajid Nasim
Keyword(s):  
Pore Water ◽  
River Sediment ◽  
Sediment Pore Water ◽  
Icp Ms ◽  
Microcolumn Separation

scholarly journals Halogens in pore water of peat bogs – the role of peat decomposition and dissolved organic matter

2006 ◽  
Vol 3 (1) ◽  
pp. 53-64 ◽  
Author(s):  
H. Biester ◽  
D. Selimović ◽  
S. Hemmerich ◽  
M. Petri
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pore Water ◽  
Peat Bogs ◽  
Pore Waters ◽  
Peat Pore Water ◽  
Icp Ms ◽  
Halogen Species

Abstract. Halogens are strongly enriched in peat and peatlands and such they are one of their largest active terrestrial reservoir. The enrichment of halogens in peat is mainly attributed to the formation of organohalogens and climatically controlled humification processes. However, little is known about release of halogens from the peat substrate and the distribution of halogens in the peat pore water. In this study we have investigated the distribution of chlorine, bromine and iodine in pore water of three pristine peat bogs located in the Magellanic Moorlands, southern Chile. Peat pore waters were collected using a sipping technique, which allows in situ sampling down to a depth greater than 6m. Halogens and halogen species in pore water were determined by ion-chromatography (IC) (chlorine) and IC-ICP-MS (bromine and iodine). Results show that halogen concentrations in pore water are 15–30 times higher than in rainwater. Mean concentrations of chlorine, bromine and iodine in pore water were 7–15 mg l−1, 56–123 μg l−1, and 10–20 μg l−1, which correspond to mean proportions of 10–15%, 1–2.3% and 0.5–2.2% of total concentrations in peat, respectively. Organobromine and organoiodine were the predominant species in pore waters, whereas chlorine in pore water was mostly chloride. Advection and diffusion of halogens were found to be generally low and halogen concentrations appear to reflect release from the peat substrate. Release of bromine and iodine from peat depend on the degree of peat degradation, whereas this relationship is weak for chlorine. Relatively higher release of bromine and iodine was observed in less degraded peat sections, where the release of dissolved organic carbon (DOC) was also the most intensive. It has been concluded that the release of halogenated dissolved organic matter (DOM) is the predominant mechanism of iodine and bromine release from peat.

scholarly journals Ecotoxicity of Pore Water in Meadow Soils Affected by Historical Spills of Arsenic-Rich Tailings

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 751 ◽  
Author(s):  
Agnieszka Dradrach ◽  
Katarzyna Szopka ◽  
Anna Karczewska
Keyword(s):  
Pore Water ◽  
Mineral Fertilizers ◽  
Test Plant ◽  
Mineral Fertilization ◽  
Floodplain Soil ◽  
Soil Material ◽  
The Past ◽  
Floodplain Meadow ◽  
Microbial Assay ◽  
Very High

This study was carried out in Złoty Stok, a historical centre of gold and arsenic mining. Two kinds of soil material, containing 5020 and 8000 mg/kg As, represented a floodplain meadow flooded in the past by tailings spills and a dry meadow developed on the plateau built of pure tailings, respectively. The effects of soil treatment with a cattle manure and mineral fertilizers were examined in an incubation experiment. Soil pore water was collected after 2, 7, 21, 90, and 270 days, using MacroRhizon samplers and analyzed on As concentrations and toxicity, and assessed in three bioassays: Microtox, the Microbial Assay for Risk Assessment (MARA), and Phytotox, with Sinapis alba as a test plant. In all samples, As concentrations were above 4.5 mg/L. Fertilization with manure caused an intensive release of As, and its concentration in pore water of floodplain soil reached 81.8 mg/L. Mineral fertilization caused a release of As only from the pure tailings soil. The results of bioassays, particularly of Phytotox and MARA, correlated well with As concentrations, while Microtox indices depended additionally on other factors. Very high toxicity was associated with As > 20 mg/L. Despite an effect of “aging”, pore water As remained at the level of several mg/L, causing a potential environmental risk.

scholarly journals Trace Element Determinations in Fe-Mn Oxides by High Resolution ICP-MS after Tm Addition

Talanta ◽  
2021 ◽  
pp. 122446
Author(s):  
Claire Charles ◽  
Jean-Alix Barrat ◽  
Ewan Pelleter
Keyword(s):  
High Resolution ◽  
Trace Element ◽  
Icp Ms ◽  
Mn Oxides

Microbial activity and bioturbation-induced oscillations in pore water chemistry of estuarine sediments in spring

Nature ◽  
1982 ◽  
Vol 299 (5882) ◽  
pp. 433-435 ◽  
Author(s):  
Mark E. Hines ◽  
William H. Orem ◽  
W. Berry Lyons ◽  
Galen E. Jones
Keyword(s):  
Water Chemistry ◽  
Microbial Activity ◽  
Pore Water ◽  
Estuarine Sediments ◽  
Pore Water Chemistry

scholarly journals Water-table height and microtopography control biogeochemical cycling in an Arctic coastal tundra ecosystem

2012 ◽  
Vol 9 (1) ◽  
pp. 577-591 ◽  
Author(s):  
D. A. Lipson ◽  
D. Zona ◽  
T. K. Raab ◽  
F. Bozzolo ◽  
M. Mauritz ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Microbial Activity ◽  
Oxidation State ◽  
Pore Water ◽  
Water Table ◽  
Soil Surface ◽  
The Arctic ◽  
Soil Pore Water ◽  
Fe Reduction ◽  
Flooded Areas

Abstract. Drained thaw lake basins (DTLB's) are the dominant land form of the Arctic Coastal Plain in northern Alaska. The presence of continuous permafrost prevents drainage and so water tables generally remain close to the soil surface, creating saturated, suboxic soil conditions. However, ice wedge polygons produce microtopographic variation in these landscapes, with raised areas such as polygon rims creating more oxic microenvironments. The peat soils in this ecosystem store large amounts of organic carbon which is vulnerable to loss as arctic regions continue to rapidly warm, and so there is great motivation to understand the controls over microbial activity in these complex landscapes. Here we report the effects of experimental flooding, along with seasonal and spatial variation in soil chemistry and microbial activity in a DTLB. The flooding treatment generally mirrored the effects of natural landscape variation in water-table height due to microtopography. The flooded portion of the basin had lower dissolved oxygen, lower oxidation-reduction potential (ORP) and higher pH, as did lower elevation areas throughout the entire basin. Similarly, soil pore water concentrations of organic carbon and aromatic compounds were higher in flooded and low elevation areas. Dissolved ferric iron (Fe(III)) concentrations were higher in low elevation areas and responded to the flooding treatment in low areas, only. The high concentrations of soluble Fe(III) in soil pore water were explained by the presence of siderophores, which were much more concentrated in low elevation areas. All the aforementioned variables were correlated, showing that Fe(III) is solubilized in response to anoxic conditions. Dissolved carbon dioxide (CO2) and methane (CH4) concentrations were higher in low elevation areas, but showed only subtle and/or seasonally dependent effects of flooding. In anaerobic laboratory incubations, more CH4 was produced by soils from low and flooded areas, whereas anaerobic CO2 production only responded to flooding in high elevation areas. Seasonal changes in the oxidation state of solid phase Fe minerals showed that net Fe reduction occurred, especially in topographically low areas. The effects of Fe reduction were also seen in the topographic patterns of pH, as protons were consumed where this process was prevalent. This suite of results can all be attributed to the effect of water table on oxygen availability: flooded conditions promote anoxia, stimulating dissolution and reduction of Fe(III), and to some extent, methanogenesis. However, two lines of evidence indicated the inhibition of methanogenesis by alternative e- acceptors such as Fe(III) and humic substances: (1) ratios of CO2:CH4 evolved from anaerobic soil incubations and dissolved in soil pore water were high; (2) CH4 concentrations were negatively correlated with the oxidation state of the soluble Fe pool in both topographically high and low areas. A second set of results could be explained by increased soil temperature in the flooding treatment, which presumably arose from the increased thermal conductivity of the soil surface: higher N mineralization rates and dissolved P concentrations were observed in flooded areas. Overall, these results could have implications for C and nutrient cycling in high Arctic areas where warming and flooding are likely consequences of climate change.

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