scholarly journals High mercury sorption in low organic matter aquifer material using column experiments.

2021 ◽  
Author(s):  
David McLagan ◽  
Carina Esser ◽  
Lorenz Schwab ◽  
Jan Pietrucha ◽  
Jan Wiederhold ◽  
...  
Keyword(s):  
Organic Matter ◽  
Column Experiments ◽  
Aquifer Material ◽  
High Mercury

scholarly journals Sorption of benzothiazoles onto sandy aquifer material under equilibrium and nonequlibrium conditions

2014 ◽  
Vol 79 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Marijana Kragulj ◽  
Jelena Trickovic ◽  
Bozo Dalmacija ◽  
Ivana Ivancev-Tumbas ◽  
Anita Leovac ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sorption Isotherms ◽  
Column Experiments ◽  
Sorption Mechanism ◽  
Desorption Process ◽  
Sorption Behaviour ◽  
Freundlich Model ◽  
Aquifer Material ◽  
Nonequilibrium Conditions ◽  
Sandy Aquifer

In this study, the sorption behaviour of 1,3-benzothiazole (BT) and 2-(methylthio)benzothiazole (MTBT) was investigated on Danube geosorbent under equilibrium and nonequilibrium conditions. All sorption isotherms fitted well with the Freundlich model (R2=0.932-0.993). The results showed that organic matter of the Danube geosorbent has a higher sorption affinity for the more hydrophobic MTBT compared to BT. However, sorption-desorption experiments showed that MTBT was more easily desorbed than BT molecules, which indicates the importance of absorption relative to adsorption in the overall sorption mechanism of MTBT. In general, molecules of BT and MTBT were more easily desorbed in the lower concentration range, which resulted in an increase in the hysteresis indices with increasing concentrations. Column experiments revealed that retention of the investigated compounds on the aquifer material followed the compound?s hydrophobicity. BT showed a lower retention, in accordance with its lower sorption affinity obtained in the static experiments, while MTBT showed a greater sorption affinity, and thus had a longer retention time on the column. Thus during transport BT represent greater risk for groundwaters than MTBT. These results have increased our understanding of benzothiazoles sorption and desorption process which represent one of the most important factors which influence the behaviour of organic compounds in the environment.

Sorption of phenols onto sandy aquifer material: the effect of dissolved organic matter (DOM)

2005 ◽  
Vol 39 (5) ◽  
pp. 933-941 ◽  
Author(s):  
Fariba Amiri ◽  
Hilmar Börnick ◽  
Eckhard Worch
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Aquifer Material ◽  
Sandy Aquifer

scholarly journals Mercury Methylation and Demethylation in Anoxic Lake Sediments and by Strictly Anaerobic Bacteria

1998 ◽  
Vol 64 (3) ◽  
pp. 1013-1017 ◽  
Author(s):  
K.-R. Pak ◽  
R. Bartha
Keyword(s):  
Organic Matter ◽  
Anaerobic Bacteria ◽  
Mercury Methylation ◽  
Strictly Anaerobic ◽  
Anoxic Sediment ◽  
Acetogenic Bacteria ◽  
High Potentials ◽  
High Mercury ◽  
Pure Cultures ◽  
Sediment Ph

ABSTRACT After spiking anoxic sediment slurries of three acidic oligotrophic lakes with either HgCl2 at 1.0 μg/ml or CH3HgI at 0.1 μg/ml, both mercury methylation and demethylation rates were measured. High mercury methylation potentials were accompanied by high demethylation potentials in the same sediment. These high potentials correlated positively with the concentrations of organic matter and dissolved sulfate in the sediment and with mercury levels in fish. Adjustment of the acidic sediment pH to neutrality failed to influence either the methylation or the demethylation rate of mercury. The opposing methylation and demethylation processes converged to establish similar Hg2+-CH3Hg+equilibria in all three sediments. Because of their metabolic dominance in anoxic sediments, mercury methylation and demethylation in pure cultures of sulfidogenic, methanogenic, and acetogenic bacteria were also measured. Sulfidogens both methylated and demethylated mercury, but the methanogen tested only catalyzed demethylation and the acetogen neither methylated nor demethylated mercury.

scholarly journals Subsurface arsenic removal column tests: from the laboratory to the field

2012 ◽  
Vol 5 (1) ◽  
pp. 193-207 ◽  
Author(s):  
D. H. Moed ◽  
D. van Halem ◽  
J. Q. J. C. Verberk ◽  
J. A. M. van Paassen ◽  
L. C. Rietveld
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Arsenic Removal ◽  
Column Experiments ◽  
Groundwater Pumping ◽  
Column Tests ◽  
Competitive Effects ◽  
Water Composition ◽  
Factors Influencing ◽  
Pumping Stations

<p><strong>Abstract.</strong> Previous laboratory column experiments have given evidence of competitive effects between different groundwater constituents in the process of subsurface arsenic removal, a process in which arsenic is removed from groundwater by injecting water with oxygen into the subsurface. The presence of phosphate and other anions significantly limited arsenic removal. To investigate the influence of phosphate in natural groundwater, pumping stations in Loosdrecht (the Netherlands) and Subotica (Serbia) both with low phosphate concentrations (&amp;lt;0.1 mg l<sup>−1</sup>) and considerable arsenic concentrations (30 and 110 μg l<sup>−1</sup>) were chosen, to perform experiments identical to the previous laboratory work. Despite of the absence of phosphate, the subsurface arsenic removal process performed poorly in Subotica, with 50% arsenic breakthrough occurring after 2 to 4 column pore volumes of abstracted water. In Loosdrecht subsurface arsenic removal showed more promising results, 50% breakthrough after 6 to 7 pore volumes, while having a lower pH than Subotica and similar silicate concentrations. The water composition of both locations gives reason to suggest that natural organic matter has a limiting effect on subsurface arsenic removal as well. The presented results have shown the complexity of factors influencing subsurface arsenic removal, making it very challenging to select appropriate sites.</p>

Retention and plant availability of chromium in soils as affected by lime and organic matter amendments

Soil Research ◽  
2001 ◽  
Vol 39 (5) ◽  
pp. 1091 ◽  
Author(s):  
N. S. Bolan ◽  
S. Thiagarajan
Keyword(s):  
Organic Matter ◽  
Pinus Radiata ◽  
Contaminated Soils ◽  
Opposite Effect ◽  
Organic Amendment ◽  
Column Experiments ◽  
Fluidised Bed ◽  
Tannery Industry ◽  
Cr Concentration ◽  
Pinus Radiata Bark

Chromium is used as Cr(III) in the tannery industry and as Cr(VI) in the timber treatment industry. In this experiment, the effect of 2 liming materials [fluidised bed boiler ash (FBA) and lime] and an organic amendment (Pinus radiata bark) on the retention of Cr by 2 soils (Egmont and Tokomaru) was examined using both ‘batch’ and ‘column’ experiments. The effect of these amendments on the uptake of Cr from the Egmont soil, treated with various levels of Cr (0–3200 mg Cr/kg soil), was examined using sunflower (Helianthus annuus) plants. The transformation of Cr was examined by fractionation of Cr in soils. Addition of FBA and lime increased the retention of Cr(III), but had the opposite effect on the retention of Cr(VI). Addition of bark did not affect the retention of Cr(III), but it increased the retention of Cr(VI). Increasing additions of Cr increased Cr concentration in plants, resulting in decreased plant growth. The liming materials were found to be effective in reducing the phytotoxicity of Cr(III) and the Pinus radiata bark was effective for Cr(VI). In both Cr(III)- and Cr(VI)-contaminated soils, the concentrations of Cr were higher in the organic-bound, oxide-bound, and residual fractions than in the soluble and the exchangeable fractions. The concentrations of Cr in the soluble and the exchangeable fractions were higher in the Cr(VI)-contaminated than the Cr(III)-contaminated soil. Addition of the liming materials decreased the concentration of the soluble Cr(III) and bark decreased soluble Cr(VI) in soil. There was evidence for the reduction of Cr(VI) to Cr(III) in the bark-treated soils.

Impact of Dissolved Organic Matter on Copper Mobility in Aquifer Material

2003 ◽  
Vol 32 (5) ◽  
pp. 1829-1836 ◽  
Author(s):  
Nizhou Han ◽  
Michael L. Thompson
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Aquifer Material

scholarly journals Microbial Community Diversity Associated with Carbon and Nitrogen Cycling in Permeable Shelf Sediments

2006 ◽  
Vol 72 (9) ◽  
pp. 5689-5701 ◽  
Author(s):  
Evan M. Hunter ◽  
Heath J. Mills ◽  
Joel E. Kostka
Keyword(s):  
Organic Matter ◽  
Nitrogen Cycling ◽  
Rrna Genes ◽  
Column Experiments ◽  
Ssu Rrna ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Cycling ◽  
In Situ Conditions ◽  
Shelf Sediments

ABSTRACT Though a large fraction of primary production and organic matter cycling in the oceans occurs on continental shelves dominated by sandy deposits, the microbial communities associated with permeable shelf sediments remain poorly characterized. Therefore, in this study, we provide the first detailed characterization of microbial diversity in marine sands of the South Atlantic Bight through parallel analyses of small-subunit (SSU) rRNA gene (Bacteria), nosZ (denitrifying bacteria), and amoA (ammonia-oxidizing bacteria) sequences. Communities were analyzed by parallel DNA extractions and clone library construction from both sediment core material and manipulated sediment within column experiments designed for geochemical rate determinations. Rapid organic-matter degradation and coupled nitrification-denitrification were observed in column experiments at flow rates resembling in situ conditions over a range of oxygen concentrations. Numerous SSU rRNA phylotypes were affiliated with the phyla Proteobacteria (classes Alpha-, Delta-, and Gammaproteobacteria), Planctomycetes, Cyanobacteria, Chloroflexi, and Bacteroidetes. Detectable sequence diversity of nosZ and SSU rRNA genes increased in stratified redox-stabilized columns compared to in situ sediments, with the Alphaproteobacteria comprising the most frequently detected group. Alternatively, nitrifier communities showed a relatively low and stable diversity that did not covary with the other gene targets. Our results elucidate predominant phylotypes that are likely to catalyze carbon and nitrogen cycling in marine sands. Although overall diversity increased in response to redox stabilization and stratification in column experiments, the major phylotypes remained the same in all of our libraries, indicating that the columns sufficiently mimic in situ conditions.

Sorption Behaviour of Phenols on Natural Sandy Aquifer Material during Flow-through Column Experiments: The Effect of pH

2004 ◽  
Vol 32 (3) ◽  
pp. 214-224 ◽  
Author(s):  
Fariba Amiri ◽  
Md. Mokhlesur Rahman ◽  
Hilmar Börnick ◽  
Eckhard Worch
Keyword(s):  
Column Experiments ◽  
Sorption Behaviour ◽  
Effect Of Ph ◽  
Aquifer Material ◽  
Flow Through ◽  
Sandy Aquifer
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