scholarly journals Metal Mobility in a Mine-Affected Floodplain

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 814
Author(s):  
Dariusz Ciszewski ◽  
Urszula Aleksander-Kwaterczak
Keyword(s):  
River Water ◽  
Water Table ◽  
Exchangeable Cations ◽  
Metal Mobility ◽  
Metal Mobilization ◽  
Anaerobic Conditions ◽  
Intrinsic Attenuation ◽  
Fe Speciation ◽  
Variable Potential

The study attempted to map and predict the remobilization of metals in a floodplain which had been heavily affected by long-term Zn–Pb mining. This research, based on Zn, Cd, Pb, Ca and Fe speciation, mineralogy and the stratigraphy of sediments which had accumulated over the distance of a dozen or so km from the mine, revealed variable potential for metal mobilization. The results suggest that a drop in the water table, something to be expected after the closure of a mine, would be accompanied by a decrease in the pH of the river water and can induce the remobilization of metals associated with carbonates and exchangeable cations over the short-reach downstream of the mine. However, the mobilization of contaminants may be impeded by the alkaline, impermeable stratum of loams, which play a pivotal role in maintaining anaerobic conditions and buffering the acidity resulting from the partial degradation of sulfides. Based on the findings of the study, it can be expected that the intrinsic attenuation will limit the need for remediation works, although monitoring river water quality is recommended to determine the need for any intervention in cases where permissible quality values have been exceeded over a longer period. Results of this research can be useful as a reference for remediation works planned in other contaminated river systems experiencing water table lowering, where the mobilization of contaminants as a consequence of sediment oxidization can be expected.

Drawdowns at the Free Water Table During Pumping Tests in Artesian and Semiartesian Aquifers

1980 ◽  
Vol 11 (3-4) ◽  
pp. 159-168 ◽  
Author(s):  
Henrik Kærgaard
Keyword(s):  
Water Table ◽  
Free Water ◽  
Pumping Test ◽  
Water Withdrawal ◽  
Specific Yield ◽  
Minor Role ◽  
Long Term Effects ◽  
Long Term Storage ◽  
Term Storage

In an earlier paper I have shown an example of how long term drawdowns can be used for the computation of long term storage in artesian and semiartesian areas. In most cases the long term storage is more or less equivalent to the specific yield at the water table; the storage mechanisms of consolidation playing a minor role in long term situations. The specific yield in artesian areas is a very important parameter in the prediction of long term effects of ground water withdrawal. Especially the stream depletion will often mainly be governed by draw-downs in upper nonpumped aquifers near the water table, and these drawdowns depend to a great extent on the specific yield at the water table. A determination of long term storage will often necessitate long term draw-down data, however, under certain circumstances a determination can be made on the basis of a pumping test of limited duration (3-5 weeks) provided drawdown observations at the water table can be made. In this paper some formulas dealing with water table drawdowns in different geohydrologic systems are reviewed, and two cases in which these formulas have been used in practice are presented.

Danube Field Excursion 1988: Tritium Content of River Water; Radioactivity of Danube Sediments

1990 ◽  
Vol 22 (5) ◽  
pp. 203-210 ◽  
Author(s):  
D. Rank ◽  
F. J. Maringer ◽  
W. Papesch ◽  
V. Rajner
Keyword(s):  
River Water ◽  
Bottom Sediments ◽  
Nuclear Power ◽  
Radioactive Material ◽  
Reactor Accident ◽  
Tritium Content ◽  
Fine Sediments ◽  
Fish Samples ◽  
Field Excursion

Water, sediment, and fish samples were collected during the Danube excursion 1988, within a coordinated sampling program of the Radiology Working Group of the “Internationale Arbeitsgemeinschaft Donauforschung ” (K.Hübel, Munich; I. Kurcz, Budapest; D.Rank, Vienna). The H-3 content of the river water and the radioactivity of the bottom sediments were measured at the BVFA Arsenal, Vienna. The determined H-3 content of the Danube water corresponds with the long-term trend in the H-3 content of the hydrosphere; the values lie in the range of 3 Bq/kg downstream from Belgrade, upstream from Belgrade they are about 4 Bq/kg. It was only in the waste water plume of the nuclear power station of Kozloduj that a slightly elevated H-3 value - 6 Bq/kg - was determined. The content of the sediments of artificial radionuclides was found, at the time of the Danube field excursion, to be almost exclusively due to the radioactive material released following the reactor accident at Chernobyl in April 1986 (mainly Cs-137 and Cs-134). As a consequence of the air currents and precipitation conditions prevailing at the time of the accident, the bottom sediments in the lower course of the Danube were less contaminated than those in the upper course. The fine sediments were found to contain over 3000 Bq/kg of Cs-137 in the upper course of the Danube.

Effect of Anticonvulsants on the Uptake of 5-Methyltetrahydrofolic Acid by the Choroid Plexus in Rabbits

1977 ◽  
Vol 53 (1) ◽  
pp. 75-80
Author(s):  
H. Taguchi ◽  
Z. Abdul-Cader ◽  
J. Perry ◽  
E. H. Reynolds ◽  
I. Chanarin
Keyword(s):  
Folic Acid ◽  
Low Temperature ◽  
Choroid Plexus ◽  
Incubation Medium ◽  
Pernicious Anaemia ◽  
Inhibitory Effect ◽  
Anaerobic Conditions ◽  
Acid Therapy ◽  
Pteroylglutamic Acid

1. The isolated choroid plexus of the rabbit takes up 5-methyltetrahydrofolate from the incubation medium. 2. Other folate analogues (pteroylglutamic acid, methotrexate, 5-formyltetrahydrofolate = folinic acid) inhibited the uptake of 5-methyltetrahydrofolate. 3. The uptake of 5-methyltetrahydrofolate was inhibited by low temperature, anaerobic conditions and dinitrophenol. 4. The anticonvulsant drugs, diphenylhydantoin and phenobarbital, had no effect on 5-methyltetrahydrofolate uptake. 5. The inhibitory effect of pteroylglutamic acid on the uptake of 5-methyltetrahydrofolate by the choroid plexus may explain the effect of long-term folic acid therapy in aggravating vitamin B12 neuropathy in pernicious anaemia.

scholarly journals Exploring and Quantifying River Thermal Response to Heatwaves

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1098 ◽  
Author(s):  
Sebastiano Piccolroaz ◽  
Marco Toffolon ◽  
Christopher Robinson ◽  
Annunziato Siviglia
Keyword(s):  
Water Temperature ◽  
River Water ◽  
Thermal Response ◽  
Hydrological Regime ◽  
Management Policy ◽  
Extreme Weather Events ◽  
Thermal Dynamics ◽  
Depth Analysis ◽  
River Water Temperature

Most of the existing literature on river water temperature focuseds on river thermal sensitivity to long-term trends of climate variables, whereas how river water temperature responds to extreme weather events, such as heatwaves, still requires in-depth analysis. Research in this direction is particularly relevant in that heatwaves are expected to increase in intensity, frequency, and duration in the coming decades, with likely consequences on river thermal regimes and ecology. In this study we analyzed the long-term temperature and streamflow series of 19 Swiss rivers with different hydrological regime (regulated, low-land, and snow-fed), and characterized how concurrent changes in air temperature and streamflow concurred to affect their thermal dynamics. We focused on quantifying the thermal response to the three most significant heatwave events that occurred in Central Europe since 1950 (July–August 2003, July 2006, and July 2015). We found that the thermal response of the analyzed rivers contrasted strongly depending on the river hydrological regime, confirming the behavior observed under typical weather conditions. Low-land rivers were extremely sensitive to heatwaves. In sharp contrast, high-altitude snow-fed rivers and regulated rivers receiving cold water from higher altitude hydropower reservoirs or diversions showed a damped thermal response. The results presented in this study suggest that water resource managers should be aware of the multiple consequences of heatwave events on river water temperature and incorporate expected thermal responses in adaptive management policy. In this respect, additional efforts and dedicated studies are required to deepen our knowledge on how extreme heatwave events can affect river ecosystems.

scholarly journals Long-Term Monitoring of Radiocesium Concentration in Sediments and River Water along Five Rivers in Minami-Soma City during 2012–2016 Following the Fukushima Dai-ichi Nuclear Power Plant Accident

2018 ◽  
Vol 8 (8) ◽  
pp. 1319 ◽  
Author(s):  
Kiyoshi Shizuma ◽  
Wim Ikbal Nursal ◽  
Yushi Sakurai
Keyword(s):  
River Water ◽  
Nuclear Power ◽  
Gamma Ray ◽  
137Cs Concentration ◽  
Flow Conditions ◽  
High Accumulation ◽  
Ge Detector ◽  
Long Term Monitoring ◽  
Term Monitoring

Radiocesium monitoring in sediments and river water has been conducted along five rivers in Minami-Soma City during 2012–2016 to clarify the temporal changes of radiocesium contamination in these rivers. Sampling has been performed annually under normal flow conditions. Sediment and river water samples were collected from four or five sampling sites along each river. Gamma-ray measurements of sediments were performed using a low-background Ge detector and unfiltered river water was utilized to determine radiocesium concentration using a well-type Ge detector. The 137Cs concentration in sediments was highest at upstream sites and slowly decreased to downstream sites for all rivers reflecting the high radioactive contamination in the upstream area. Temporal decrease of the 137Cs concentration was observed in sediments and river water for each river. The effective half-lives were 1.3–2.1 y for sediments, and 0.9–2.1 y for river water from rivers with upstream dams. On the undammed river, the effective half-lives were 4.7 y and 3.7 y for sediment and river water, respectively. Much longer effective-half-lives might reflect the direct transfer of radiocesium from forests and plains to the river. The 137Cs concentration in riverbed was low in downstream areas, however, accumulation of 137Cs over the floodplain was observed. Rapid decrease of 137Cs contamination through rivers will put residents at ease, but high accumulation of radiocesium over floodplains should be noted for future river decontamination.

Effects of long-term water table drawdown on evapotranspiration and vegetation in an arid region phreatophyte community

2006 ◽  
Vol 325 (1-4) ◽  
pp. 21-34 ◽  
Author(s):  
David J. Cooper ◽  
John S. Sanderson ◽  
David I. Stannard ◽  
David P. Groeneveld
Keyword(s):  
Water Table ◽  
Arid Region

Water table dynamics of Dhaka city and its long-term trend analysis using the “MAKESENS” model

2009 ◽  
Vol 34 (3) ◽  
pp. 373-382 ◽  
Author(s):  
A. A. Sarkar ◽  
M. H. Ali
Keyword(s):  
Trend Analysis ◽  
Water Table ◽  
Dhaka City ◽  
Term Trend ◽  
Long Term Trend

Development and application of long-term root zone salt balance model for predicting soil salinity in arid shallow water table area

2019 ◽  
Vol 213 ◽  
pp. 486-498 ◽  
Author(s):  
Guanfang Sun ◽  
Yan Zhu ◽  
Ming Ye ◽  
Jinzhong Yang ◽  
Zhongyi Qu ◽  
...  
Keyword(s):  
Shallow Water ◽  
Water Table ◽  
Soil Salinity ◽  
Root Zone ◽  
Balance Model ◽  
Salt Balance ◽  
Shallow Water Table
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