scholarly journals Mercury mobility, colloid formation and methylation in a polluted fluvisol as affected by manure application and flooding-draining cycle

2021 ◽  
Author(s):  
Lorenz Gfeller ◽  
Andrea Weber ◽  
Isabelle Worms ◽  
Vera I. Slaveykova ◽  
Adrien Mestrot
Keyword(s):  
Organic Matter ◽  
Soil Solution ◽  
Natural Organic Matter ◽  
Inductively Coupled Plasma ◽  
Point Sources ◽  
Inductively Coupled ◽  
Soil Systems ◽  
Floodplain Soils ◽  
Plasma Mass Spectrometry ◽  
Colloid Formation

Abstract. Floodplain soils polluted with high levels of mercury (Hg) are potential point sources to downstream eco-systems. Repeated flooding (e.g. redox cycling) and agricultural activities (e.g. organic matter addition) may influence the fate and speciation of Hg in these soil systems. The formation and aggregation of colloids and particles influences both Hg mobility and its bioavailability to methylmercury (MeHg) forming microbes. In this study, we conducted a microcosm flooding-draining experiment on Hg polluted floodplain soils originating from an agriculturally used area situated in the Rhone Valley (Valais, Switzerland). The experiment comprised two 14 days flooding periods separated by one 14 days draining period. The effect of freshly added natural organic matter on Hg dynamics was assessed by adding liquid cow manure (+MNR) to two control soils characterized by different Hg (47.3 ± 0.6 mg kg−1 or 2.38 ± 0.01 mg kg−1) and organic carbon (OC: 1.92 wt. % or 3.45 wt. %) contents. During the experiment, the release, colloid formation and methylation of Hg in the soil solution were monitored. Upon manure addition in the highly polluted soil (lowest OC), an accelerated release of Hg to the soil solution could be linked to a fast reductive dissolution of Mn oxides. The manure treatments showed a fast sequestration of Hg and a higher percentage of particulate (0.02–10 µm) bound Hg. As well, analyses of soil solutions by asymmetrical flow field-flow fractionation coupled with inductively coupled plasma mass spectrometry (AF4–ICP–MS) revealed a proportional increase of colloidal DOM-Hg and inorganic colloidal Hg (+MNR: 70–100 %; control: 32–70 %) upon manure addition. Our experiment shows that net Hg methylation (MeHg/Hg) was highest after the first draining period and decreased again after the second flooding period. No significant effects on methylation upon manure addition was found. The results of this study suggest that manure addition may promote sequestration by Hg complexation on large organic matter components and the formation/aggregation of inorganic HgS(s) colloids in Hg polluted fluvisols with low levels of natural organic matter.

scholarly journals Mercury mobility, colloid formation and methylation in a polluted Fluvisol as affected by manure application and flooding–draining cycle

2021 ◽  
Vol 18 (11) ◽  
pp. 3445-3465
Author(s):  
Lorenz Gfeller ◽  
Andrea Weber ◽  
Isabelle Worms ◽  
Vera I. Slaveykova ◽  
Adrien Mestrot
Keyword(s):  
Organic Matter ◽  
Soil Solution ◽  
Natural Organic Matter ◽  
Inductively Coupled Plasma ◽  
Relative Increase ◽  
Point Sources ◽  
Inductively Coupled ◽  
Floodplain Soils ◽  
Subsequent Decrease ◽  
Colloid Formation

Abstract. Floodplain soils polluted with high levels of mercury (Hg) are potential point sources to downstream ecosystems. Repeated flooding (e.g., redox cycling) and agricultural activities (e.g., organic matter addition) may influence the fate and speciation of Hg in these soil systems. The formation and aggregation of colloids and particles influence both Hg mobility and its bioavailability to microbes that form methylmercury (MeHg). In this study, we conducted a microcosm flooding–draining experiment on Hg-polluted floodplain soils originating from an agriculturally used area situated in the Rhone Valley (Valais, Switzerland). The experiment comprised two 14 d flooding periods separated by one 14 d draining period. The effect of freshly added natural organic matter on Hg dynamics was assessed by adding liquid cow manure (+MNR) to two soils characterized by different Hg (47.3±0.5 or 2.38±0.01 mg kg−1) and organic carbon (OC: 1.92 wt % or 3.45 wt %) contents. During the experiment, the release, colloid formation of Hg in soil solution and net MeHg production in the soil were monitored. Upon manure addition in the highly polluted soil (lower OC), an accelerated release of Hg to the soil solution could be linked to a fast reductive dissolution of Mn oxides. The manure treatments showed a fast sequestration of Hg and a higher percentage of Hg bound by particulate (0.02–10 µm). Also, analyses of soil solutions by asymmetrical flow field-flow fractionation coupled with inductively coupled plasma mass spectrometry (AF4–ICP–MS) revealed a relative increase in colloidal Hg bound to dissolved organic matter (Hg–DOM) and inorganic colloidal Hg (70 %–100 %) upon manure addition. Our experiment shows a net MeHg production the first flooding and draining period and a subsequent decrease in absolute MeHg concentrations after the second flooding period. Manure addition did not change net MeHg production significantly in the incubated soils. The results of this study suggest that manure addition may promote Hg sequestration by Hg complexation on large organic matter components and the formation and aggregation of inorganic HgS(s) colloids in Hg-polluted Fluvisols with low levels of natural organic matter.

INFLUENCE OF ORGANIC MATTER ON Re-Os DATING OF SULFIDES: INSIGHTS FROM THE GIANT JINDING SEDIMENT-HOSTED Zn-Pb DEPOSIT, CHINA

2021 ◽  
Author(s):  
Shiqiang Huang ◽  
Yucai Song ◽  
Limin Zhou ◽  
David L. Leach ◽  
Zhaoshan Chang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Inductively Coupled Plasma ◽  
Elemental Mapping ◽  
Bacterial Reduction ◽  
Inductively Coupled ◽  
Hydrocarbon Reservoir ◽  
Low Concentrations ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Two Stages

Abstract This study evaluates the effect of organic matter impurities on pyrite Re-Os dating, using the giant Jinding sediment-hosted Zn-Pb deposit in China as an example. The Jinding deposit is hosted in a Paleocene evaporite dome that was a hydrocarbon reservoir before mineralization. Pyrite in Jinding formed in two stages: pre-ore (py1) and syn-ore (py2). Two types of py1 are recognized, organic matter-free and organic matter-bearing. The organic matter-free py1 contains homogeneously distributed low concentrations of Re (<2.5 ppb) that yields an isochron age of 51 ± 1 Ma (mean square of weighted deviates [MSWD] = 3.2). This date is interpreted to be the age of py1 formation. The organic matter-bearing py1 contains organic matter inclusions trapped during py1 growth and synchronous with bacterial reduction of sulfate. Elemental mapping with laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) shows that the organic matter inclusions have Re signals 1 to 4 orders of magnitude higher than those of pyrite, revealing that organic matter is the major host for Re. Such pyrite separates contain 37 to 1,145 ppb Re. The Re-Os data of organic matter-bearing py1 yield an isochron age of 72.9 ± 0.5 Ma (MSWD = 0.2). This age is older than the actual py1 formation age of 51 ± 1 Ma but overlaps with previously dated bitumen Re-Os isochron age of 68 ± 5 Ma at Jinding, indicating that organic matter inclusions can significantly influence the Re-Os dates of pyrite and likely other sulfides. This study demonstrates that in order to date sulfides formed in organic-rich environments using the Re-Os method, it is necessary to determine the distribution of Re in samples using detailed petrography and LA-ICP-MS trace element mapping plus spot analysis.

scholarly journals Stability of inorganic arsenic species in simulated raw waters with the presence of NOM

2006 ◽  
Vol 6 (6) ◽  
pp. 175-182 ◽  
Author(s):  
G.J. Liu ◽  
X.R. Zhang ◽  
J. Jain ◽  
J.W. Talley ◽  
C.R. Neal
Keyword(s):  
Natural Organic Matter ◽  
Inductively Coupled Plasma ◽  
Inorganic Arsenic ◽  
Arsenic Species ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Mass Spectrometry System ◽  
The Stability ◽  
Inorganic Arsenic Species

Effect of natural organic matter (NOM) on the stability of inorganic arsenic species in simulated raw water was examined at circumneutral pH. An ion chromatography–inductively coupled plasma mass spectrometry system was used for simultaneous determination of As(III) and As(V). A reduction of arsenate (As(V)) to arsenite (As(III)) was observed in the unfiltered simulated raw waters (USW). The As(V) reduction to As(III) did not occur in the simulated waters that passed through a 0.2 μm membrane (FSW). Microorganism activities is probably the major reason causing As(V) reduction in the USW. In the FSW without NOM, As(III) tended to be oxidized into As(V). The addition of 0.036 mM of Fe(II) significantly facilitated the oxidation. The presence of 10 mg/L Suwannee River NOM as C inhibited As(III) oxidation no matter whether Fe(II) existed or not. The experimental results suggest that NOM can mediate distribution of inorganic arsenic species in water, thus it is an important factor controlling the mobility and toxicity of arsenic in drinking water.

scholarly journals Aluminium, Iron and Silicon Subcellular Redistribution in Wheat Induced by Manganese Toxicity

2021 ◽  
Vol 11 (18) ◽  
pp. 8745
Author(s):  
Jorge M. S. Faria ◽  
Dora Martins Teixeira ◽  
Ana Paula Pinto ◽  
Isabel Brito ◽  
Pedro Barrulas ◽  
...  
Keyword(s):  
Soil Solution ◽  
Subcellular Distribution ◽  
Inductively Coupled Plasma ◽  
Plant Tissues ◽  
Acidic Soils ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
High Concentrations ◽  
Mn Concentration

Acidic soils can promote the bioavailability of Al, Mn, and Fe to toxic levels, reducing crop growth and productivity. Symptoms of metal excess/deficit are dependent on the chemical composition of the soil solution and of plant tissues. In the present study, the concentration and subcellular distribution of Al, Mn, Fe, and Si (known to alleviate metal stress) were quantified through inductively coupled plasma mass spectrometry (ICP-MS) in roots and shoots of wheat grown in acidic soils with rising levels of Mn. In control acidic soil, wheat showed high concentrations of Al, Mn, and Fe. After Mn supplementation, bioavailable Al, Fe, and Si levels increased in the soil solution, but plant uptake ratio decreased. Root Mn levels increased, while those of Al, Fe, and Si decreased. Although elements were increasingly translocated to the shoot, root Al and Fe concentrations were 10-fold higher than those in the shoot. At the highest Mn concentration supplied, Al, Fe, and Si proportions increased in the organelles, while Mn proportion increased in the vacuole. High bioavailable Mn levels disrupt metal homeostasis in wheat grown in acidic soils, influencing element subcellular distribution. Symptoms of metal toxicity result from interactions between several elements, and therefore a comprehensive chemical analysis of soil solution and plant tissues contributes to a more accurate understanding of their uptake dynamics and their agronomic implications.

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