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1.
Unlike the majority of the water in the flooded mine complex of Butte Montana, which includes the highly acidic Berkeley pit lake, groundwater in the flooded West Camp underground mine workings has a circum-neutral pH and contains at least 8 μM aqueous sulfide. This article examines the geochemistry and stable isotope composition of this unusual H2S-rich mine water, and also discusses problems related to the colorimetric analysis of sulfide in waters that contain FeS(aq) cluster compounds. The West Camp mine pool is maintained at a constant elevation by continuous pumping, with discharge water that contains elevated Mn (90 μM), Fe (16 μM), and As (1.3 μM) but otherwise low metal concentrations. Dissolved inorganic carbon in the mine water is in chemical and isotopic equilibrium with rhodochrosite in the mineralized veins. The mine water is under-saturated with mackinawite and amorphous FeS, but is supersaturated with Cu- and Zn-sulfides. However, voltammetry studies show that much of the dissolved sulfide and ferrous iron are present as FeS(aq) cluster molecules: as a result, the free concentration of the West Camp water is poorly constrained. Concentrations of dissolved sulfide determined by colorimetry were lower than gravimetric assays obtained by AgNO3 addition, implying that the FeS(aq) clusters are not completely extracted by the Methylene Blue reagent. In contrast, the clusters are quantitatively extracted as Ag2S after addition of AgNO3. Isotopic analysis of co-existing aqueous sulfide and sulfate confirms that the sulfide was produced by sulfate-reducing bacteria (SRB). The H2S-rich mine water is not confined to the immediate vicinity of the extraction well, but is also present in flooded mine shafts up to 3 km away, and in samples bailed from mine shafts at depths up to 300 m below static water level. This illustrates that SRB are well established throughout the southwestern portion of the extensive (>15 km3) Butte flooded mine complex.  相似文献   

2.
A system of connected lignite mining pits (part of the former Goitsche mining complex, Germany) was flooded with river water between 1999 and 2002. A considerable accumulation of acid associated with oxidized sulfides in sediments was seen as a critical point for the development of the lake water. To characterize the components contributing to the supply of dissolved lake water SO4 hydro-chemical and isotope investigations with respect to groundwater, pore water in the sulfide bearing sediments, river water and lake water were performed. δ34S of pore water SO4 that was dominated by oxidized pyrites ranges around −25‰ VCDT and differs strongly from river water SO4 with about +4.4‰. Thus, interactions between lake water and sediments were particularly pronounced during the first phase of flooding. For this period, a more quantitative estimation of the SO4 components in the lake water was difficult because of the heterogeneous SO4 distributions between the different sub-basins of the lake and according to the flooding process itself. Later, a component separation was attempted following mixing of the whole lake, which first occurred in spring 2002. A very heterogeneous groundwater environment with respect to highly variable SO4 concentrations and δ34S values and changing interaction with the forming lakes proved to be one of the most important limitations in the calculations of the mixing.  相似文献   

3.
. This paper summarizes a laboratory study of water–rock interaction and the generation of acidic mine drainage in the Butte mining district, Montana. The Butte district includes two large open pit mines exploiting different portions of the same porphyry Cu–Mo system: (1) the well-known Berkeley Pit, which is abandoned and flooding with acidic mine water; and (2) the nearby Continental Pit, which is active. The two pits are separated by a normal fault with several thousand feet of vertical displacement, and consequently the styles of alteration and mineralization are quite different. Humidity cell and recirculating leachate experiments of crushed rock exposed on the walls of the Berkeley Pit produced effluent waters very similar in composition to the flooded Berkeley Pit lake. In contrast, the same experiments on crushed ore from the Continental Pit generated circum-neutral leachates with low metal concentrations, caused by the presence of calcite in the alteration assemblage. Because carbonate is being depleted at a faster rate than pyrite during weathering, the quality of mine drainage in the Continental Pit could eventually degrade.  相似文献   

4.
With depleted coal resources or deteriorating mining geological conditions, some coal mines have been abandoned in the Fengfeng mining district, China. Water that accumulates in an abandoned underground mine (goaf water) may be a hazard to neighboring mines and impact the groundwater environment. Groundwater samples at three abandoned mines (Yi, Er and Quantou mines) in the Fengfeng mining district and the underlying Ordovician limestone aquifer were collected to characterize their chemical and isotopic compositions and identify the sources of the mine water. The water was HCO3·SO4-Ca·Mg type in Er mine and the auxiliary shaft of Yi mine, and HCO3·SO4-Na type in the main shaft of Quantou mine. The isotopic compositions (δD and δ18O) of water in the three abandoned mines were close to that of Ordovician limestone groundwater. Faults in the abandoned mines were developmental, possibly facilitating inflows of groundwater from the underlying Ordovician limestone aquifers into the coal mines. Although the Sr2+ concentrations differed considerably, the ratios of Sr2+/Ca2+ and 87Sr/86Sr and the 34S content of SO42? were similar for all three mine waters and Ordovician limestone groundwater, indicating that a close hydraulic connection may exist. Geochemical and isotopic indicators suggest that (1) the mine waters may originate mainly from the Ordovician limestone groundwater inflows, and (2) the upward hydraulic gradient in the limestone aquifer may prevent its contamination by the overlying abandoned mine water. The results of this study could be useful for water resources management in this area and other similar mining areas.  相似文献   

5.
The Lake Chany complex and nearby lakes in western Siberia (Russian Federation) were studied to constrain the S cycle in these terrestrial lake environments. Surface water chemistry was characterized by Na–SO4–Cl composition, comparable to other inland basins in semi-arid climatic zones associated with marine evaporite-bearing formations at depth. Dissolved sulfates showed elevated δ34S (up to +32.3‰). These values are quite distinct from those in similar saline lakes in northern Kazakhstan, the Aral Sea, Lake Barhashi, and a gypsum deposit in the Altai Mountains. The localized distribution of such a unique S isotopic signature in dissolved SO4 negates both aeolian and catastrophic flooding hypotheses previously suggested for the genesis of the dissolved salts. The probable source of the dissolved SO4 in Lake Chany basin is inherited from hidden saline groundwaters (whose location and origins remain unclear) from eastern Paleozoic ranges with Upper Devonian formations with heavy S isotope values. Post-depositional enrichment of heavy S in the dissolved SO4 from saline sediments may be caused by local activity of SO4-reducing bacteria under the ambient supply of electron donors (dissolved river load organic matter and decaying bacterial mats) in the lake complex. Such microbial processes can remove up to ca. 60% of SO4 from the system. Extensive and intensive evaporation of lake fluids, ca. 40%, was indicated by the progressive enrichment of δ18O values in meteoric water samples collected along the river and lake system. This evaporation process compensates the microbial loss of SO4 dissolved in the incoming river water.  相似文献   

6.
《Applied Geochemistry》2001,16(9-10):1215-1230
Oxidation rates of low sulphide (<0.5 wt.%) gneissic waste rock from the Cluff lake U mine, northern Saskatchewan, Canada were determined using 3 independent methods: O2 consumption rates in kinetic cells, SO4 measurements of kinetic cell effluent and humidity cell SO4 release rates. The O2 consumption measurements demonstrated that the oxidation of pyrite was strongly dependent on grain size and moderately dependent on water content, temperature and microbiology. Oxygen consumption rates were highest at water contents of 5–10 wt.% (12–25% saturation). Measured SO4 release rates (3.1–91 mg SO4 kg−1 wk−1) for the kinetic cells were comparable to rates calculated from the O2 consumption values (6.9–70 mg SO4 kg−1 wk−1). Sulphate release rates determined from humidity cells were generally higher than those obtained from the kinetic cells, ranging from 6 to 64 mg SO4 kg−1 wk−1 for the coarsest and finest fraction, respectively. These differences were attributed to sample heterogeneity.  相似文献   

7.
Stable isotopes were used to determine the sources and fate of dissolved inorganic C (DIC) in the circumneutral pH drainage from an abandoned bituminous coal mine in western Pennsylvania. The C isotope signatures of DIC (δ13CDIC) were intermediate between local carbonate and organic C sources, but were higher than those of contemporaneous Pennsylvanian age groundwaters in the region. This suggests a significant contribution of C enriched in 13C due to enhanced carbonate dissolution associated with the release of H2SO4 from pyrite oxidation. The Sr isotopic signature of the drainage was similar to other regional mine waters associated with the same coal seam and reflected contributions from limestone dissolution and cation exchange with clay minerals. The relatively high δ34SSO4 and δ18OSO4 isotopic signatures of the mine drainage and the presence of presumptive SO4-reducing bacteria suggest that SO4 reduction activity also contributes C depleted in 13C isotope to the total DIC pool. With distance downstream from the mine portal, C isotope signatures in the drainage increased, accompanied by decreased total DIC concentrations and increased pH. These data are consistent with H2SO4 dissolution of carbonate rocks, enhanced by cation exchange, and C release to the atmosphere via CO2 outgassing.  相似文献   

8.
《Applied Geochemistry》2005,20(4):789-805
Mineralogical, hydrochemical and S isotope data were used to constrain hydrogeochemical processes that produce acid mine drainage from sulfidic waste at the historic Mount Morgan Au–Cu mine, and the factors controlling the concentration of SO4 and environmentally hazardous metals in the nearby Dee River in Queensland, Australia. Some highly contaminated acid waters, with metal contents up to hundreds of orders of magnitude greater than the Australia–New Zealand environmental standards, by-pass the water management system at the site and drain into the adjacent Dee River.Mine drainage precipitates at Mt. Morgan were classified into 4 major groups and were identified as hydrous sulfates and hydroxides of Fe and Al with various contents of other metals. These minerals contain adsorbed or mineralogically bound metals that are released into the water system after rainfall events. Sulfate in open pit water and collection sumps generally has a narrow range of S isotope compositions (δ34S = 1.8–3.7‰) that is comparable to the orebody sulfides and makes S isotopes useful for tracing SO4 back to its source. The higher δ34S values for No. 2 Mill Diesel sump may be attributed to a difference in the source. Dissolved SO4 in the river above the mine influence and 20 km downstream show distinctive heavier isotope compositions (δ34S = 5.4–6.8‰). The Dee River downstream of the mine is enriched in 34S (δ34S = 2.8–5.4‰) compared with mine drainage possibly as a result of bacterial SO4 reduction in the weir pools, and in the water bodies within the river channel. The SO4 and metals attenuate downstream by a combination of dilution with the receiving waters, SO4 reduction, and the precipitation of Fe and Al sulfates and hydroxides. It is suggested here that in subtropical Queensland, with distinct wet and dry seasons, temporary reducing environments in the river play an important role in S isotope systematics.  相似文献   

9.
In 2005 and 2006, hydrogeochemical study was carried out in the bipartite Wiśniówka Mała pit lake of the Holy Cross Mountains (south-central Poland). This is the largest acidic water body in Poland. This report presents the element concentrations in the water and sediment, stable sulfur and oxygen isotope ratios in the soluble sulfates, and stable oxygen isotope ratio in the water. The scope of the investigation also encompassed mineralogical examinations (scanning electron microscope, X-ray diffraction) of the sediment. The results of this study show that there is a spatial and temporal variability in concentrations of most elements and sulfur isotope ratios in the examined pit lake. The water of the western pond displayed a lower pH with a mean of 3.73 and higher conductivity (390 μS cm−1) as well as higher concentrations of sulfates (156 mg L−1) and most of the cations and anions. The concentrations of Fe2+ and Fe3+ averaged 0.8 and 0.4 mg·L−1. In contrast, the eastern pond water revealed a higher pH (mean of 4.36), lower conductivity (293 μS cm−1) and lower sulfate (90 mg L−1) and trace metal levels. Similar variations were recorded in the stable sulfur isotope ratios. The δ34SV-CDT(SO4 2−) values in the water of the western pit pond were in the range of −6.7 to −4.6‰ (mean of −5.6‰), whereas that in the eastern pit pond ranged from −2.2 to −0.9‰ (−1.6‰). The alkalinity of the entire lake water was below 0.1 mg·L−1 CaCO3. No distinct difference in the δ18OV-SMOW(SO4 2−) was noted between the western and eastern pit ponds. Compared to the Purple Pond in the Sudetes (Poland) and similar sites throughout the world, the examined pit lake is highlighted by distinctly low concentrations of sulfates, iron and other trace metals. Based on this and other studies performed in the Holy Cross Mountains, a conclusion can be drawn that the SO4 2− in the Wiśniówka Mała pit lake water is a mixture of SO4 2− derived from the following sources: (1) pyrite oxidation (especially in the western pond water), (2) leaching of soluble sulfates from soils and waste material, as well as (3) subordinate deposition of airborne sulfate precipitation.  相似文献   

10.
Chemical composition and equilibrium trends in mine pit lakes were examined to provide guidance for the application of geochemical models in predicting future lake water quality at prospective open pit mines. Composition trends show that elevated solute levels generally occur only at the extremes of acidic and alkaline pH conditions. Concentrations of cationic metals (Al, Cd, Cu, Fe, Mn, Pb, and Zn) are elevated only in acidic pit lakes, whereas anionic metalloids (As and Se) are generally elevated only in alkaline pit lakes. These trends are indicative of sulfide mineral oxidation and evapoconcentration for acidic and alkaline conditions, respectively.For nearly all pit lakes, SO4 is the dominant solute, but is limited by gypsum solubility. Fluorite, calcite, and barite are also important solubility controls. Well-defined solubility controls exist for the major metals (Al, Fe, Mn), including jurbanite and alunite for Al, ferrihydrite for Fe, and manganite, birnessite, and, possibly, rhodochrosite for Mn. Determinations of definite controls for the minor metals are less distinct, but may include otavite for Cd, brochantite and malachite for Cu, cerrusite and pyromorphite for Pb, and hydrozincite and Zn silicates for Zn. Concentrations of As and Se appear to be limited only by adsorption, but this control is sharply diminished by increased pH and SO4 concentration. In general, the concentrations of minor metals in pit lakes are not well represented by the theoretical solubilities of pure-phase minerals contained in the thermodynamic databases. Hence, modeling efforts will generally have to rely on empirical data on the leaching characteristics of pit wall-rocks to predict the concentrations of minor metals (Cd, Cu, Pb, Zn) in mine pit lakes.Methodologies for predicting pit lake water chemistry are still evolving. Geochemical and equilibrium trends in existing pit lakes can provide valuable information for guiding the development and application of predictive models. However, mineralogical studies of pit lake sediments, suspended particles, and alteration assemblages and studies of redox transformations are still needed to validate and refine the representations of geochemical processes in water quality models of mine pit lakes.  相似文献   

11.
Seawater inrush is deadly to undersea mine and it is very important to accurately assess the connectivity between seawater and the mine pit. With Xinli gold mine area as a case study, following the analysis of geological setting, a detailed hydrogeological survey and sampling were conducted and conservative ions test of mine water samples was carried out in the laboratory. Furthermore, the physical significances of ion concentration and ion ratios, such as Cl?, γSO4 2?/γCl? and γNa+/γCl?, were checked. The test data analysis, enhanced by the physical significance check and hierarchy clustering analysis, was used to assess the overlying seawater inrush into the mine pit. It was determined that the undersea rock masses in the Xinli mine area bear high-mineralization brine water. The ore-controlling fault gouge and a thin layer of clay in Quaternary block the seepage of overlying seawater into the undersea mine pit to a great extent. The mine water from surrounding rock of the northeast gopher drift is closer to seawater in hydrogeochemical features, which indicates that the connectivity between the northeast of footwall of the ore-controlling fault and seawater is relatively good and should be closely monitored in future production. The mine water from the southwest gopher drift and crosscuts is similar to the brine (salty) water in chemical features, drains the net reserves of brine (salty) water in bedrock fissures and will impose few impacts on production in the near future. This approach is feasible and cost-effective.  相似文献   

12.
A long mining history and unscientific exploitation of Jharia coalfield caused many environmental problems including water resource depletion and contamination. A geochemical study of mine water in the Jharia coalfield has been undertaken to assess its quality and suitability for domestic, industrial and irrigation uses. For this purpose, 92 mine water samples collected from different mining areas of Jharia coalfield were analysed for pH, electrical conductivity (EC), major cations (Ca2+, Mg2+, Na+, K+), anions (F−, Cl−, HCO3 −, SO4 2−, NO3 −), dissolved silica (H4SiO4) and trace metals. The pH of the analysed mine water samples varied from 6.2 to 8.6, indicating mildly acidic to alkaline nature. Concentration of TDS varied from 437 to 1,593 mg L−1 and spatial differences in TDS values reflect the variation in lithology, surface activities and hydrological regime prevailing in the region. SO4 2− and HCO3 − are dominant in the anion and Mg2+ and Ca2+ in the cation chemistry of mine water. High concentrations of SO4 2− in the mine water of the area are attributed to the oxidative weathering of pyrites. Ca–Mg–SO4 and Ca–Mg–HCO3 are the dominant hydrochemical facies. The drinking water quality assessment indicates that number of mine water samples have high TDS, total hardness and SO4 2− concentrations and needs treatment before its utilization. Concentrations of some trace metals (Fe, Mn, Ni, Pb) were also found to be above the desirable levels recommended for drinking water. The mine water is good to permissible quality and suitable for irrigation in most cases. However, higher salinity, residual sodium carbonate and Mg-ratio restrict its suitability for irrigation at some sites.  相似文献   

13.
Oxidation of sulfides at the Leona Heights Sulfur Mine has resulted in the liberation of acid, SO4 and metals to Leona Creek. Previous research at the site has indicated Fe(II) oxidation at rates faster than would be predicted by abiotic oxidation alone, particularly in the segment of stream between the Adit and Leona Street sample stations. In order to assess the mechanisms responsible for sulfide oxidation, samples were collected for isotopic analysis of water and SO4, the results of which were used to develop a stoichiometric isotope-balance model. This exercise indicated that the percentage of water-derived oxygen in SO4 increased spatially from between 56% and 64% at the Adit to between 71% and 72% at Leona Street, illustrating that increased sulfide oxidation via Fe(III) was occurring within, or as water flows over, the waste rock, relative to water emanating directly from the former mine. The incorporation of water-derived oxygen in SO4 during pyrite oxidation is a process controlled by Fe oxidizing bacteria such as A. ferrooxidans at low pH. The role of bacteria was further supported by estimates of the rate constant for Fe oxidation between sampling stations, yielding values that were approximately 106 faster than abiotic Fe oxidation alone. Stable isotopic analysis of water further indicates a close correlation of adit spring water to the local meteoric water line, while 3H data indicate a groundwater apparent age, or time of travel from its primary zone of recharge, of <5–18 a. Additionally, the δ34S data, in conjunction with reported albitized feldspars within the Leona Rhyolite host rock, indicate a magmatic origin of ore sulfur, contrary to previous interpretations at the site.  相似文献   

14.
Ion chemistry of mine pit lake water reveals dominance of alkaline earths (Ca2+ and Mg2+) over total cation strength, while SO4 2? and Cl? constitute the majority of total anion load. Higher value of Ca2+?+?Mg2+/Na+?+?K+ (pre-monsoon 5.986, monsoon 8.866, post-monsoon 7.09) and Ca2+?+?Mg2+/HCO3 ??+?SO 4 2 (pre-monsoon 7.14, monsoon 9.57, post-monsoon 8.29) is explained by weathering of Ca?CMg silicates and dissolution of Ca2+-bearing minerals present in parent rocks and overburden materials. Silicate weathering supposed to be the major geological contributor, in contrast to bicarbonate weathering does a little. Distribution coefficient for dissolved metals and sorbed to surface sediments is in the order of Cd?>?Pb?>?Fe?>?Zn?>?Cu?>?Cr?>?Mn. Speciation study of monitored metals in surface sediments shows that Fe and Mn are dominantly fractionated in exchangeable-acid reducible form, whereas rest of the metals (Cr, Pb, Cd, Zn, and Cu) mostly in residual form. Cd, Pb, and Zn show relatively higher recalcitrant factor that indicates their higher retention in lake sediments. Factor loading of monitored physico-chemical parameters resembles contribution/influences from geological weathering, anthropogenic inputs as well as natural temporal factors. Ionic load/strength of lake water accounted for geochemical process and natural factors, while pollutant load (viz BOD, COD and metals, etc.) is associated with anthropogenic inputs through industrial discharge.  相似文献   

15.
The main terminal processes of organic matter mineralization in anoxic Black Sea sediments underlying the sulfidic water column are sulfate reduction in the upper 2-4 m and methanogenesis below the sulfate zone. The modern marine deposits comprise a ca. 1-m-deep layer of coccolith ooze and underlying sapropel, below which sea water ions penetrate deep down into the limnic Pleistocene deposits from >9000 years BP. Sulfate reduction rates have a subsurface maximum at the SO42−-CH4 transition where H2S reaches maximum concentration. Because of an excess of reactive iron in the deep limnic deposits, most of the methane-derived H2S is drawn downward to a sulfidization front where it reacts with Fe(III) and with Fe2+ diffusing up from below. The H2S-Fe2+ transition is marked by a black band of amorphous iron sulfide above which distinct horizons of greigite and pyrite formation occur. The pore water gradients respond dynamically to environmental changes in the Black Sea with relatively short time constants of ca. 500 yr for SO42− and 10 yr for H2S, whereas the FeS in the black band has taken ca. 3000 yr to accumulate. The dual diffusion interfaces of SO42−-CH4 and H2S-Fe2+ cause the trapping of isotopically heavy iron sulfide with δ34S = +15 to +33‰ at the sulfidization front. A diffusion model for sulfur isotopes shows that the SO42− diffusing downward into the SO42−-CH4 transition has an isotopic composition of +19‰, close to the +23‰ of H2S diffusing upward. These isotopic compositions are, however, very different from the porewater SO42− (+43‰) and H2S (−15‰) at the same depth. The model explains how methane-driven sulfate reduction combined with a deep H2S sink leads to isotopically heavy pyrite in a sediment open to diffusion. These results have general implications for the marine sulfur cycle and for the interpretation of sulfur isotopic data in modern sediments and in sedimentary rocks throughout earth’s history.  相似文献   

16.
Groundwater samples were collected at a site in N Norfolk, UK, comprising a borehole penetrating Upper Chalk and piezometers open within the overlyinf glacial deposits and intervening, weathered Putty Chalk. The samples were analyzed for δ18O (water), δ34S and δ18O(SO4) and δ13C(HCO3) as well as major ions. Variations in solute concentration and isotopic composition with depth were found to be caused by limited groundwater circulation at the site and incomplete flushing of old groundwater. The isotopic data prove the existence of a mineralized palaeowater at depth, which has undergone SO4 reduction and is being slowly modified by mixing with recent groundwater circulating at a shallow depth in a more transmissive Chalk horizon. One measured δ18O (H2O) value of −8.25‰vsmow represents the lightest value reported for the Norfolk Chalk aquifer and is evidence for a component of Late Pleistocene recharge trapped at depth.The wide range of observed isotope ratios at the site, e.g.δ34S and δ18O SO4 between 7.8 to 27.8‰cdt and 5.2 to 20.0‰ovsmow respectively, demonstrates the importance of vertical stratification of solutes and the implications this has for interpreting spatial hydrochemical surveys of groundwater.  相似文献   

17.
Surface snow and lake water samples were collected at different locations around Indian station at Antarctica, Maitri, during December 2004–March 2005 and December 2006–March 2007. Samples were analyzed for major chemical ions. It is found that average pH value of snow is 6.1. Average pH value of lake water with low chemical content is 6.2 and of lake water with high chemical content is 6.5. The Na+ and Cl? are the most abundantly occurring ions at Antarctica. Considerable amount of SO 4 2? is also found in the surface snow and the lake water which is attributed to the oxidation of DMS produced by marine phytoplankton. Neutralization of acidic components of snow is mainly done by NH 4 + and Mg2+. The Mg2+, Ca2+ and K+ are nearly equally effective in neutralizing the acidic components in lake water. The NH 4 + and SO 4 2? occur over the Antarctica region mostly in the form of (NH4)2SO4.  相似文献   

18.
Mine water samples collected from different mines of the North Karanpura coalfields were analysed for pH, electrical conductivity, total dissolved solids (TDS), total hardness (TH), major anions, cations and trace metals to evaluate mine water geochemistry and assess solute acquisition processes, dissolved fluxes and its suitability for domestic, industrial and irrigation uses. Mine water samples are mildly acidic to alkaline in nature. The TDS ranged from 185 to 1343 mg L?1 with an average of 601 mg L?1. Ca2+ and Mg2+ are the dominant cations, while SO4 2? and HCO3 ? are the dominant anions. A high concentration of SO4 2? and a low HCO3 ?/(HCO3 ? + SO4 2?) ratio (<0.50) in the majority of the water samples suggest that either sulphide oxidation or reactions involving both carbonic acid weathering and sulphide oxidation control solute acquisition processes. The mine water is undersaturated with respect to gypsum, halite, anhydrite, fluorite, aluminium hydroxide, alunite, amorphous silica and oversaturated with respect to goethite, ferrihydrite, quartz. About 40% of the mine water samples are oversaturated with respect to calcite, dolomite and jarosite. The water quality assessment shows that the coal mine water is not suitable for direct use for drinking and domestic purposes and needs treatment before such utilization. TDS, TH, F?, SO4 2?, Fe, Mn, Ni and Al are identified as the major objectionable parameters in these waters for drinking. The coal mine water is of good to suitable category for irrigation use. The mines of North Karanpura coalfield annually discharge 22.35 × 106 m3 of water and 18.50 × 103 tonnes of solute loads into nearby waterways.  相似文献   

19.
《Applied Geochemistry》1998,13(2):185-195
The occurrence and significance of aqueous flow through fractures in unsaturated tuff was investigated at the Apache Leap Research Site near Superior, Arizona. Water samples for geochemical and isotopic analysis were collected from water seeping from fractures in a mine haulage tunnel, from the saturated zone in a vertical borehole (USW UZP-4), and from both the unsaturated and saturated zones in an angled borehole (DSB). The geochemistry and14C activity of water samples from the DSB suggest that most of the recharge to the saturated zone has occurred through fractures, especially beneath the ephemeral streams. Evidence of substantial recent recharge through fractures was found in saturated-zone samples from the mine haulage tunnel using 3H, δ34S and SO42−/Cl− analyses. Evidence of partial imbibition of fracture flow into the rock matrix was found at multiple depths throughout the 147 m unsaturated zone at the DSB using geophysical measurements from the borehole, water-content analyses from core samples, and 14C and 3H analyses from pore water extracted from preserved core samples. Post-bomb 14C activity was measured in pore water near fractures just above the saturated zone.  相似文献   

20.
The Aha Lake is a seasonal anoxic water system in the southwest of Guiyang City, Guizhou Province, China. Seasonal variations in SO42- concentrations and their isotopic compositions in lake water as well as in the tributaries were investigated in this study. The results showed that sulfate concentrations in river water range from 0.94 to 6.52 mmol/L and their δ34S values range from -14.9‰ and 0.9‰, while lake water has sulfate concentrations ranging from 1.91 to 2.79 mmol/L, and δ34S values from -9.8‰ to -5.9‰. It is suggested that coal mining drainage is the major source of SO42- in the Aha Lake. Rainfall, sewage discharge, sulfide oxidation and gypsum dissolution have made only limited contributions. Different depth-dependent distributions of dissolved SO42- and δ34S were de-veloped for both DB and LJK in summer and winter. Due to water overturn, δ34S values display homogenous vertical distributions in winter and spring. While in summer and autumn, significant positive shifts of δ34S were clearly ob-served in epilimnion and bottom strata as a result of water stratification. High δ34S values in epilimnion may result from the retention of rainwater during water stratification. Dissimilatory sulfate reduction by bacteria was thought to be responsible for the increase of δ34S value in hypolimnion.  相似文献   

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