Geochemical evolution of inactive pyritic tailings in the Elliot Lake uranium district

1985 ◽  
Vol 22 (1) ◽  
pp. 110-128 ◽  
Author(s):  
N. M. Dubrovsky ◽  
J. A. Cherry ◽  
E. J. Reardon ◽  
A. J. Vivyurka
Keyword(s):  
Heavy Metals ◽  
Water Table ◽  
Ferric Hydroxide ◽  
Low Ph ◽  
Geochemical Evolution ◽  
Geochemical Data ◽  
Secondary Aluminum ◽  
Tailings Impoundments ◽  
High Concentrations ◽  
Uranium Tailings

Geochemical data obtained between 1979 and 1983 from a network of piezometer nests and cores from three inactive uranium tailings impoundments in the Elliot Lake district indicate that oxidation of pyrite taking place in the shallow part of the zone above the water table is causing the chemistry of the pore water above and below the water table to change. A two-layer hydrochemical zonation has developed in which infiltration water from rain and snow has resulted in an upper zone of low-pH water with high concentrations of SO4, Fe, and heavy metals. This zone is gradually expanding downward at rates generally between 0.2 and 2 m/year, causing displacement of the original mill process water, which has neutral pH and low concentrations of heavy metals. High concentrations of Fe(III) at shallow depth in the zone above the water table indicate that ferric iron is an important oxidizer of pyrite in the presence of free oxygen.The pe of the groundwaters is controlled by the ferric–ferrous redox couple, and trends in the data indicate iron solubility control by siderite at high pH, by ferric hydroxide at moderate to slightly acid pH values, and possibly by jarosite at low pH. Aluminum solubility controls are complex, and precipitation of amorphous aluminum hydroxide, allophane, and basic aluminum sulfates may occur over different pH ranges. Transport of low-pH conditions is retarded relative to the rate of groundwater flow in the tailings, because of the buffering effect of small amounts of carbonate minerals added during tailings neutralization; primary aluminosilicates such as sericite; and secondary aluminum hydroxides.Field data show that the flux of dissolved iron from the vadose zone to the groundwater zone in the Nordic Main tailings has been decreasing in recent years. However, mass-balance calculations indicate a potential for the generation of high-Fe groundwater for several decades to several hundred years. A long-term potential for acid and iron production is also shown by data from two tailings impoundments that have been inactive 8–10 years longer than the Nordic Main area. Presently only a small portion of the Nordic Main and West Arm tailings areas has become acidic through the entire tailings thickness; however, under existing infiltration conditions more extensive acidification will occur in future decades.

Uranium Tailings Acidification and Subsurface Contaminant Migration in a Sand Aquifer

1984 ◽  
Vol 19 (2) ◽  
pp. 55-89 ◽  
Author(s):  
N.M. Dubrovsky ◽  
K.A. Morin ◽  
J.A. Cherry ◽  
D.J.A. Smyth
Keyword(s):  
Heavy Metals ◽  
Vadose Zone ◽  
Inner Core ◽  
Pyrite Oxidation ◽  
Outer Zone ◽  
Low Ph ◽  
Small Stream ◽  
Sand Aquifer ◽  
Uranium Tailings ◽  
Stream Bed

Abstract Investigations of the geochemistry of inactive pyritic uranium tailings in the Elliot Lake Mining district of Ontario have focused on the Nordic tailings management area, where two impoundments are located in natural bedrock basins. The tailings are 8-12 m thick and overlie a localized deposit of glaciofluvial sands. Analyses of the solid, liquid, and gas phases in the vadose zone of the tailings show that gas-phase oxygen levels drop rapidly within 0.7 to 1.5 m of the surface, indicating rapid oxygen consumption during pyrite oxidation. Oxidation during the past 15 to 20 years has caused a marked depletion of near-surface pyrite. The oxidation of pyrite in the vadose zone imparts to infiltrating precipitation high concentrations of Fe, SO42-, various heavy metals, and a pH generally between 1.5 and 4. The acidic infiltration moves downward at a rate of 0.2 to 2.0 m/yr, displacing high-pH groundwater that originated as process water discharged from the mill. It now occupies the entire tailings thickness over a small area of the tailings. At one location a well-defined plume of high-Fe2+ tailings-derived groundwater has developed in the sand aquifer adjacent to the tailings. The plume consists of three zones: an inner core characterized by Fe > 5000 mg/L, pH < 4.8, and elevated concentrations of several heavy metals and radionuclides; an outer zone with Fe < 2500 mg/L, pH > 5.5, and relatively low concentrations of heavy metals and radionuclides; and a transition zone separating the two. Although the average linear groundwater velocity is about 440 m/yr near the dam, reactions such as mineral dissolution, precipitation and coprecipitation retard the migration of the front of the inner core, producing an observed frontal migration rate of approximately 1 m/yr. Groundwater from the outer zone of the plume flows laterally towards a small stream, where a portion of it is now discharging into the stream bed. The discharge results in the precipitation of amorphous ferric hydroxide on the stream bed. Most of the H+ produced by Fe precipitation is buffered, and only a moderate decrease in stream pH is observed. Inner zone conditions will not reach the stream unless input of low-pH groundwater from the tailings continues for several hundred years. Although the rate of pyrite oxidation in the Nordic Main tailings has been decreasing, there is sufficient pyrite in the tailings to generate high-Fe groundwater for several decades or more. Calculated groundwater migration rates indicate that in the next few decades acidic, low-pH groundwater will occupy the entire tailings thickness over most of the tailings area, causing an increase in the total flux of contaminated groundwater into the underlying aquifer. The outer zone of the plume has already arrived at a small stream, and acidification of the surface waters may increase if the Fe concentration in the groundwater seepage increases.

New Technologies for Decontamination of Radioactive Substances Scattered by Nuclear Accident / Nowe Technologie Dekontaminacji Radioaktywnych Substancji Rozproszonych Przez Awarie Nuklearna

2013 ◽  
Vol 58 (1) ◽  
pp. 283-290 ◽  
Author(s):  
Y. Nishizaki ◽  
H. Miyamae ◽  
S. Ichikawa ◽  
K. Izumiya ◽  
T. Takano ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
New Technologies ◽  
Ferric Hydroxide ◽  
Nuclear Accident ◽  
Radioactive Cesium ◽  
Cesium Ions ◽  
Naoh Solution ◽  
High Concentrations ◽  
Water Rinsing

Our effort for decontamination of radioactive cesium scattered widely by nuclear accident in March 2011 in Fukushima, Japan has been described. Radioactive cesium scattered widely in Japan has been accumulating in arc or plasma molten-solidified ash in waste incinerating facilities up to 90,000 Bq/kg of the radioactive waste. Water rinsing of the ash resulted in dissolution of cesium ions together with high concentrations of potassium and sodium ions. Although potassium inhibits the adsorption of cesium on zeolite, we succeeded to precipitate cesium by in-situ formation of ferric ferrocyanide and iron rust in the radioactive filtrate after rinsing of the radioactive ash with water. Because the regulation of no preservation of any kind of cyanide substances, cesium was separated from the precipitate consisting of cesium-captured ferric ferrocyanide and ferric hydroxide in diluted NaOH solution and subsequent filtration gave rise to the potassium-free radioactive filtrate. Cesium was captured by zeolite from the potassium-free radioactive filtrate. The amount of this final radioactive waste of zeolite was significantly lower than that of the arc-molten-solidified ash.

scholarly journals Spatial Variation of Water Chemistry in Aries River Catchment Western Romania

2021 ◽  
Vol 11 (14) ◽  
pp. 6592
Author(s):  
Ana Moldovan ◽  
Maria-Alexandra Hoaghia ◽  
Anamaria Iulia Török ◽  
Marius Roman ◽  
Ionut Cornel Mirea ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Water Chemistry ◽  
Water Samples ◽  
Mine Drainage ◽  
Pollution Indices ◽  
Mining Activities ◽  
River Catchment ◽  
High Concentrations ◽  
The Impact

This study aims to investigate the quality and vulnerability of surface water (Aries River catchment) in order to identify the impact of past mining activities. For this purpose, the pollution and water quality indices, Piper and Durov plots, as well vulnerability modeling maps were used. The obtained results indicate that the water samples were contaminated with As, Fe, Mn, Pb and have relatively high concentrations of SO42−, HCO3−, TDS, Ca, K, Mg and high values for the electrical conductivity. Possible sources of the high content of chemicals could be the natural processes or the inputs of the mine drainage. Generally, according to the pollution indices, which were correlated to high concentrations of heavy metals, especially with Pb, Fe and Mn, the water samples were characterized by heavy metals pollution. The water quality index classified the studied water samples into five different classes of quality, namely: unsuitable for drinking, poor, medium, good and excellent quality. Similarly, medium, high and very high vulnerability classes were observed. The Durov and Piper plots classified the waters into Mg-HCO3− and Ca-Cl− types. The past and present mining activities clearly change the water chemistry and alter the quality of the Aries River, with the water requiring specific treatments before use.

Reduction for heavy metals in pickling sludge with aluminum nitride in secondary aluminum dross by pyrometallurgy, followed by glass ceramics manufacture

2021 ◽  
pp. 126331
Author(s):  
Hanlin Shen ◽  
Bo Liu ◽  
Zhisheng Shi ◽  
Shizhen Zhao ◽  
Junjie Zhang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Aluminum Nitride ◽  
Glass Ceramics ◽  
Secondary Aluminum ◽  
Aluminum Dross ◽  
Pickling Sludge

scholarly journals Chemical composition of leaves of a mangrove tree (Sonneratia apetala Buch.-Ham.) and their correlation with some soil variables

1970 ◽  
Vol 39 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Ashafaque Ahmed ◽  
Mikael Ohlson ◽  
Sirajul Hoque ◽  
Md Golam Moula
Keyword(s):  
Heavy Metals ◽  
Chemical Composition ◽  
Coastal Zone ◽  
Organic Matter Content ◽  
Matter Content ◽  
Sonneratia Apetala ◽  
Mangrove Tree ◽  
Soil Variables ◽  
Wide Range ◽  
High Concentrations

Chemical composition of leaves of Sonneratia apetala Buch.-Ham. collected from three islands (chars) representing three hydrological regimes in a segment of the coastal zone of Bangladesh was studied. Their relations to some soil chemical and physical variables have also been investigated. The results showed that concentrations of B, C, Fe, Ga, Li, Mg, Mn, N, Na, P, Zn and Sr in leaves of S. apetala grown in different islands differed significantly. It was also revealed that some heavy metals, viz. Mn, Fe, Al, Sr and Ti showed wide range of concentrations. The leaves from one of the locations in Motherbunia island were characterized by exceptional high concentrations of heavy metals such as Al, As, Cu, Fe, Li, Ni, Pb that may be due to local contamination. Leaves sampled in the most seaward locations of the same island had highest concentrations of Ba, Ca, Cu, Mn and Na. High Mn concentration was found in the leaves of S. apetala of Motherbunia island. Correlations among soil and plant samples were generally very weak and organic matter content of soil did not appear to play a significant role in the nutrient supply of S. apetala. Key words: Coastal zone; tidal inundation; elemental concentration; Sonneratia apetala DOI: 10.3329/bjb.v39i1.5528Bangladesh J. Bot. 39(1): 61-69, 2010 (June)

scholarly journals Model evaluation of seepage from uranium tailings disposal above and below the water table

1983 ◽  
Author(s):  
R.W. Nelson ◽  
P.R. Meyer ◽  
P.L. Oberlander ◽  
S.C. Sneider ◽  
D.W. Mayer ◽  
...  
Keyword(s):  
Water Table ◽  
Model Evaluation ◽  
Tailings Disposal ◽  
Uranium Tailings

scholarly journals Metallothionein and Glutathione Content as Biomarkers of Metal Pollution in Mussels and Local Fishermen in Abu Qir Bay, Egypt

2016 ◽  
Vol 6 (12) ◽  
pp. 50-60 ◽  
Author(s):  
Aziza A. Saad ◽  
Amany El-Sikaily ◽  
Hany Kassem
Keyword(s):  
Oxidative Stress ◽  
Heavy Metals ◽  
Metal Pollution ◽  
The Body ◽  
Metal Exposure ◽  
Control Group ◽  
Blood Levels ◽  
Industrial Workers ◽  
High Concentrations ◽  
Abu Qir Bay

Background. When heavy metals accumulate in air, soil, and water, the risk of human exposure increases among industrial workers, as well as in people living near polluted areas. Heavy metals adversely affect a variety of bodily systems such as the cardiovascular, respiratory, endocrine, immune, and reproductive systems. In addition, long-term exposure and accumulation of heavy metals in the body may disturb oxidative stress genes and thus increase the susceptibility to various diseases. Objectives. The aim of this study is to estimate the metallothionein concentration in both mussel samples from Abu Qir Bay, Egypt and the blood of local fishermen as a biomarker of exposure to metal pollution. Methods. Levels of metallothionein and heavy metals were measured in mussels. Blood levels of metallothionein and heavy metals of local fishermen were measured and compared with a control group. The effect of heavy metal exposure on oxidative stress status was investigated through the determination of malondialdehyde (MDA), catalase and glutathione content. Results. The results of this study showed high concentrations of metallothionein in mussels and in fishermen's blood, accompanied by high concentrations of metals such as cadmium (Cd), copper (Cu), lead (Pb), chromium (Cr), and zinc (Zn). At the same time, a significant decrease in glutathione content and catalase enzyme activity was associated with a significant increase in the malondialdehyde concentrations in sera of fishermen. Conclusions. The present study found that the El Maadiya region is polluted with heavy metals, inducing oxidative stress in fishermen in the vicinity. These results reveal the necessity of further environmental monitoring in the study area in order to evaluate other types of pollutants and their effects on human health.

scholarly journals The natural barrier to retention of the high concentration of gases: methane and carbon dioxide, methane and hydrogen under hydrothermal vents

2019 ◽  
pp. 11
Author(s):  
T.A. Smaglichenko
Keyword(s):  
Hydrothermal Vents ◽  
Geochemical Data ◽  
3D Seismic ◽  
Seismic Model ◽  
High Concentration ◽  
Geological Structures ◽  
Diffusion Parameters ◽  
High Concentrations ◽  
Tomography Method ◽  
Natural Barrier

The assumed seismic model of the area around fields having high concentrations of CH4 and CO2, CH4 and H2 dissolved in hydrothermal vents is first introduced. The model of so-called natural barrier to retention of gases accumulation has been revealed using outcomes of 3D seismic tomography method, which has been developed by the author and utilizing geochemical data that were earlier obtained by other researchers in scientific cruises and university laboratories. The built model is in agreement with a distribution of seismicity (M 2.5–4.5) that occurred during last 5 years. A comparison of diffusion parameters of methane for thermal reservoirs and rocks, and corresponding comparison of geological structures permits to suppose that the presented model can be used to find appropriated area for underground storage of gases mentioned above.

scholarly journals CHARACTERISTICS OF LEACHATE AT IHIAGWA DUMPSITE, IMO STATE NIGERIA AND THEIR IMPLICATIONS FOR SURFACE WATER POLLUTION

2021 ◽  
pp. 1-11
Author(s):  
CT Nelson ◽  
GT Amangabara ◽  
CO Owuama ◽  
CN Nzeh ◽  
CN Uyo
Keyword(s):  
Heavy Metals ◽  
Chemical Properties ◽  
Total Solid ◽  
Toxic Substances ◽  
Landfill Leachates ◽  
Total Chloride ◽  
Metal Cyanide ◽  
Physico Chemical ◽  
High Concentrations ◽  
Total Dissolved Solid

Open dumpsite is the most common way to eliminate solid urban wastes in this part of the world. An important problem associated to landfills and open dumpsite is the production of leachates. The leachates from these dumpsites have many toxic substances, which may adversely affect the environmental health. Thus in order to have a better management of characteristics of Ihiagwa-Nekede waste dump leachates, representative leachate samples were collected and analyzed for Physico-chemical properties and levels of heavy metals in them. Results indicate pH7.38, temperature 28.30 ℃ - 28.40℃, total dissolved solid 124.01mg/l-125.45mg/l, magnesium hardness 4.40mg/l-7.32mg/l, sulphate 3.60mg/l-3.70mg/l, and nitrate 27.00mg/l-27.60mg/l. Other parameters indicated as follows Conductivity1910𝜇𝑠/𝑐𝑚-1930.00 𝜇𝑠/𝑐𝑚, total chloride 891.72mg/l-891.74mg/l, carbonate 1708.00mg/l-1904.00mg/l, Ammonia 9.39mg/l-9.40mg/l, calcium hardness 373.17mg/l-375.61mg/l, total solid 2423.00mg/l-2454.00mg/l, phosphate 13.52mg/l-13.54mg/l. The heavy metal: cyanide 2.25mg/l-2.33mg/l, zinc 18.08mg/l-18.38mg/l, copper 19.90mg/l20.48mg/l, iron10.67mg/l-10.82mg/l, lead 1.27mg/l-1.41mg/l, and manganese 3.00mg/l-3.61mg/l, all these exceeded the WHO standards. The obtained results showed that the landfill leachates are characterized by high concentrations of heavy metals and other disease causing elements and therefore require urgent treatment to forestall the contamination of groundwater system and the nearby Otamiri River.

Heavy metals in deltaic sediments of the Fraser River, British Columbia

1976 ◽  
Vol 13 (12) ◽  
pp. 1683-1693 ◽  
Author(s):  
D. A. Grieve ◽  
W. K. Fletcher
Keyword(s):  
Heavy Metals ◽  
Trace Metals ◽  
Close Relationships ◽  
Fraser River ◽  
Sand Content ◽  
Sediment Texture ◽  
Delta Front ◽  
Fraser River Delta ◽  
Mn Content ◽  
High Concentrations

Co, Cu, Fe, Mn, Ni, Pb, and Zn, together with sand content and loss of ignition, have been determined for surflcial sediments from the Fraser River delta-front and upper foreslope. Both geochemical maps and statistical analysis disclose close relationships between trace-metal concentrations, sediment texture, and Fe and Mn content. Detailed studies of the distribution of labile and non-labile trace metals within sediments indicate that these relationships reflect increased concentrations of trace metals associated with both the detrital minerals and hydrous Fe oxides coatings in the finer fractions of the sediment. Abnormally high concentrations of labile trace metals are found on the tidal flats at two stations influenced by discharge of metal-rich sewage.

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