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1.
Sudhakar M. Rao B. V. Venkatarama Reddy 《Geotechnical and Geological Engineering》2006,24(6):1545-1559
The gold mining process at Kolar gold field (KGF) mines has generated about 32 million tons of tailings. Gold was extracted
from the mined ores using cyanidation technique that involved dissolution of gold in the ore by water soluble alkali metal
cyanides (example, sodium cyanide or potassium cyanide). Of the several dumps that received the mine tailings only the Kennedy’s
Line dump was active prior to closure of the KGF mines in the year 2000. The Kennedy’s Line dump received sulfide bearing
tailings in slurry form that comprised of spent ore and process water bearing soluble alkali metal cyanide. Depending on the
pH of the tailing slurry, the free cyanides may exist as aqueous hydrogen cyanide that can escape to the atmosphere as hydrogen
cyanide gas or occur as soluble cyanide (CN−) ions that can be leached by infiltrating water to the sub-surface environment. Additionally, the presence of pyrite minerals
in the Kennedy’s Line dump makes them susceptible to acid drainage. This study examines the potential of gold tailings of
Kennedy’s Line dump to release cyanide ions (CN−) and acid drainage to the sub-surface environment by performing physico-chemical and leaching tests with tailing samples
collected from various depths of the dump, sub-surface soil samples beneath the dump and groundwater samples from vicinity
of Kennedy’s Line dump. The chemical mechanisms responsible for the ambient cyanide and pH levels of the tailing dump, sub-surface
soil samples and groundwater are also inferred from the laboratory results. 相似文献
2.
V. M. Robles-Arenas R. Rodríguez C. García J. I. Manteca L. Candela 《Environmental Geology》2006,51(1):47-64
The environmental impact and potential-risk assessment of an abandoned sulphide-mining site in a semiarid climate is presented here, by the study case of Sierra de Cartagena–La Unión (SE Spain), a 2,500-year-old mining district extending over an area of 100 km2. The regional map illustrates the existence of 12 open-pits, 1,902 mining wells, 2,351 waste deposits, including 89 tailing dams and waste rock derived from mining processes. Mine wastes occupy an area of 9 km2 and have an approximate volume of 200 Mm3. Mineralogical, physical and chemical data distinguish nine different types of mine and metallurgical waste. According to the concentration of sulphate and heavy metals in sediment, soil, rainwater, surface water and groundwater samples, it is possible to conclude that the impact of mine activities occurs not only in the immediate mining area (100 km2), but also in the surrounding areas (an affected area of 1,000 km2 approximately). The hydrochemical data show that groundwater, runoff water and some rainwater samples exceed Spanish and European water quality guideline values for water supply. The main geochemical process recognised is sulphide-mineral oxidation and later-generated sulphate dissolution by groundwater and runoff. Runoff and wind are the major mechanisms of metals and sulphate transport in the study area and adjacent zones. 相似文献
3.
稳定同位素因其指纹效应已成为分析矿区污染来源的重要技术手段。文章以招远金矿区为例,应用硫同位素联合水化学分析、聚类分析及氢氧同位素分析招远金矿区水污染特征和成因。通过分析可知,矿区内地表水和地下水主要接受大气降水补给,水力联系密切。水化学类型以SO4—Ca和SO4—Na型为主,阴离子以SO42-为主,地表水和地下水的NO3-和Cl-在空间上变异性较大。地表水硫酸盐含量普遍偏高,硫酸盐污染较为严重,高值区出现在玲珑金矿、金翅岭金矿和张星镇附近;而地下水高值区都出现在玲珑金矿附近,且SO42-浓度沿着径流方向逐渐降低。地表水中硫酸盐δ34S值介于1.8‰~9.8‰,地下水中硫酸盐δ34S值介于2.7‰~9.6‰,地表水和地下水硫酸盐含量受玲珑金矿硫化、玲珑花岗岩和胶东岩群影响明显。在地下水径流途中,有地表水入渗污染地下水的现象。另外,工业废水的排放也是硫酸盐含量升高的主要原因。研究表明:硫同位素在金矿区硫酸盐污染的来源和特征方面有很好的指示作用,是评价矿山开采对地下水污染的有效工具。 相似文献
4.
Numerical modeling the role of rubber dams on groundwater recharge and phreatic evaporation loss in riparian zones 总被引：1，自引：1，他引：0
Xi Chen Min-hua Ling Qiu Zhou Zhi-cai Zhang Qin-bo Cheng 《Environmental Earth Sciences》2012,65(1):345-352
Rubber dams have been widely built for their advantages in increase of flooding resources utilization in the north arid and
semiarid plain regions of China. Rise in river water stage by the dams, particularly during the drought periods, increases
lateral seepage of river water into groundwater, and thus groundwater table and phreatic evaporation loss in the riparian
zones. In this study, a riparian area of the Baihe River in Nanyang of Henan Province, China was selected for investigation
of influences of the river dams on the groundwater recharge and evaporation loss. A hydraulic model, HEC-RAS, was used for
simulation of the river stage variations along the Baihe River, and a numerical groundwater model, MODFLOW, was applied for
simulation of groundwater dynamics and estimation of river flow seepage into aquifer and evaporation loss. The results show
that the dams increase river stages of 2–3 m during January 2000–December 2002. The increase in the captured groundwater recharge
was 7.15–34.06 million m3/a and the increased phreatic evaporation loss occupies 10% of the increased recharge when four rubber dams were built. 相似文献
5.
This research is aimed at investigating possible neutralization of cyanide in tailing dam of Muteh gold processing plant in
Isfahan, Iran at various conditions such as pH and temperature using USEPA Visual MINTEQ geochemical model simulation. The
model is based on geochemical equilibrium which uses the simultaneous solution of the non-linear mass action expressions and
linear mass balance relationships to formulate and solve the multiple-component chemical equilibrium problems. In this study
the concentration of aqueous species in tailing dam as an aqueous, solid and gaseous were used as input in the model. Temperature
and pH variation were simulated. The results of the model indicated that cyanide may be complexes in 10 < pH < 5. In other
pH values complexation is not important. The results also indicated that cyanide reduction mechanism in acidic pH and temperature
above 30°C is due to cyanide acid formation which is vaporized. 相似文献
6.
The distribution and natural degradation of cyanide in goldmine tailings and polluted soil in arid and semiarid areas 总被引：2，自引：0，他引：2
Farmlands and rivers have been seriously polluted by cyanide from a goldmine tailings dam that collapsed in early spring of 1995 in Yining County, Xinjiang Autonomous Region of China. The cyanide distribution in the polluted farmland and the abandoned tailings dam was studied, three and 4 years after the accident occurred. The results indicated that natural degradation of cyanide in soils is slower than in natural water bodies. The cyanide transport in the soil section is similar to freely soluble salts. In arid and semiarid areas, cyanide can be highly enriched in the salt crust in which the concentration is even higher than the fresh tailings debris though cyanide has decomposed for 4 years. In the polluted farmland, the sticky layer in the soil section can highly adsorb and enrich cyanide so it can partly prevent cyanide transfer to groundwater. According to the characteristics of cyanide natural degradation in soil, the measures for prevention and cure of soil polluted by goldmine tailing dam collapse have been discussed. 相似文献
7.
8.
Sequential extraction and leaching characteristics of heavy metals in abandoned tungsten mine tailings sediments 总被引：1，自引：0，他引：1
Pyeong-Koo Lee Min-Ju Kang Ho Young Jo Sang-Hoon Choi 《Environmental Earth Sciences》2012,66(7):1909-1923
The chemical speciation of potentially toxic elements (As, Cd, Cu, Pb, and Zn) in the contaminated soils and sulfides-rich tailings sediments of an abandoned tungsten mine in Korea was evaluated by conducting modified BCR sequential extraction tests. Kinetic and static batch leaching tests were also conducted to evaluate the potential release of As and other heavy metals by acidic rain water and the leaching behaviors of these heavy metals. The major sources of the elements were As-, Zn- and Pb-bearing sulfides, Pb carbonates (i.e., cerussite), and Pb sulfates (i.e., anglesite). The biggest pollutant fraction in these soil and tailing samples consists of metals bound to the oxidizable host phase, which can be released into the environment if conditions become oxidative, and/or to residual fractions. No significant difference in total element concentrations was observed between the tailings sediments and contaminated soils. For both sample types, almost no changes occurred in the mobility of As and the other heavy metals at 7 days, but the mobility increased afterwards until the end of the tests at 30 days, regardless of the initial pH. However, the mobility was approximately 5–10 times higher at initial pH 1.0 than at initial pHs of 3.0 and 5.0. The leached amounts of all the heavy metal contents were higher from tailings sediments than from contaminated soils at pH > 3.0, but were lower at pH < 3.0 except for As. Results of this study suggest that further dissolution of heavy metals from soil and tailing samples may occur during extended rainfall, resulting in a serious threat to surface and groundwater in the mine area. 相似文献
9.
Ünsal Gemici Gültekin Tarcan Cahit Helvac&#x; A. Melis Somay 《Applied Geochemistry》2008,23(8):2462-2476
This study documents the environmental impacts of borate mines in Bigadiç district, which are the largest colemanite and ulexite deposits in the world. Borate-bearing formations have affected the concentrations of some contaminants in groundwater. Groundwater quality is directly related to the borate zones in the mines as a result of water–rock interaction processes. Calcium is the dominant cation and waters are Ca–SO4 and HCO3 type in the mine (Tülü borate mine) from which colemanite is produced. However in the Simav and Acep Borate Mines, ulexite and colemanite minerals are produced and waters from these open pit mines are Na–HCO3–SO4 types. High SO4 concentrations (reaching 519 mg/L) might be explained by the existence of anhydrite, gypsum and celestite minerals in the borate zone. Groundwater from tuff and borate strata showed relatively low pH values (7–8) compared to surface and mine waters (>8). EC values ranged from 270 to 2850 μS/cm. Boron and As were the two important contaminants determined in the groundwaters around the Bigadiç borate mines. Arsenic is the major pollutant and it ranged from 33 to 911 μg/L in the groundwater samples. The concentrations of B in the study area ranged from 0.05 to 391 mg/L. The highest B concentrations were detected at the mine areas. The extension of the borate zones in the aquifer systems is the essential factor in the enrichment of B and As, and some major and trace elements in groundwaters are directly related to the leaching of the host rock which are mainly composed of tuffs and limestones. According to drinking water standards, all of the samples exceed the tolerance limit for As. Copper, Mn, Zn and Li values are enriched but do not exceed the drinking water standards. Sulfate, Al and Fe concentrations are above the drinking water standard for the groundwater samples. 相似文献
10.
Spatial and temporal variation of uranium in a shallow weathered rock aquifer in southern India 总被引：2，自引：0，他引：2
Uranium occurs naturally in groundwater and surface water. The objective of this study is to understand the causes for the
occurrence of uranium and its spatio-temporal variation in groundwater in a part of Nalgonda district, Andhra Pradesh, south
India. Uranium deposits occur in the southeastern part of this area. Groundwater samples were collected from 44 wells every
two months from March 2008 to January 2009. The samples were analyzed for pH, ORP and uranium concentration. The uranium concentration
in groundwater varies from 0.2 ppb to a maximum of 68 ppb with a mean of 18.5 ppb. About 21.6% of the samples were above the
drinking water limit of 30 ppb set by USEPA. The uranium concentration varied with fluctuation in groundwater level, pH and
ORP. Uranium concentration in groundwater changes depending on lithology, degree of weathering and rainfall recharge. 相似文献
11.
12.
以某金矿区浅层地下水为研究对象,通过分析112件浅层地下水样的Hg、Pb、Cd、Cr~(6+)、As、Cu、Zn、CN~-等重金属元素及氰化物的含量特征,初步查明了这8种元素在地下水中的赋存规律。在此基础上,分别利用单项、综合污染指数评价方法对浅层地下水环境质量进行了重金属及氰化物污染评价。结果表明,浅层地下水中除背景元素Cr~(6+)局部区域超标外,受矿业选冶活动影响,双桥河流域中下游段局部区域Hg、Pb、CN~-等元素超标,该结论对浅层地下水资源污染防治具有重要意义。 相似文献
13.
As one of the largest copper–molybdenum (Cu–Mo) mines in the world, the Erdenet Mine in Mongolia has been active since 1978 and is expected to continue operations for at least another 30 years. In this study, the potential impacts of mining activities on the soil and water environments have been evaluated. Water samples showed high concentrations of sulfate, calcium, magnesium, Mo, and arsenic, and high pH values in the order of high to low as follows: tailing water > Khangal River > groundwater. Statistical analysis and the δ2H and δ18O values of water samples indicate that the tailing water directly affects the stream water and indirectly affects groundwater through recharge processes. Soil and stream sediments are highly contaminated with Cu and Mo, which are major elements of ore minerals. Based on the contamination factor (CF), the pollution load index (PLI), and the degree of contamination (Cd), soil appears to be less contaminated than stream sediments. The soil particle size is similar to that of tailing materials, but stream sediments have much coarser particles, implying that the materials have different origins. Contamination levels in stream sediments display a tendency to decrease with distance from the mine, but no such changes are found in soil. Consequently, soil contamination by metals is attributable to wind-blown dusts from the tailing materials, and stream sediment contamination is caused by discharges from uncontained subgrade ore stock materials. Considering the evident impact on the soil and water environment, and the human health risk from the Erdenet Mine, measures to mitigate its environmental impact should be taken immediately including source control, the establishment of a systematic and continuous monitoring system, and a comprehensive risk assessment. 相似文献
14.
Noureddıne Guezgouz Djamel Boutoutaou Houarı Zeggane Azzedıne Chefrour 《Arabian Journal of Geosciences》2017,10(15):336
Water resources in Algeria are mainly controlled by climate change which creates enormous problems in its planning, management and distribution. While the surface water resources are perfectly managed and operated by means of dams and small dams built for several years, the groundwater resources remain long unknown and unusable because of the lack of relevant working tools (e.g., methods, formulas, maps, etc.) for planners and engineers working in the field of water resources exploration. To highlight the hydrodynamic processes of groundwater in shallow aquifers of the basins of northern Algeria, we conducted a study using 81 subwatersheds collected from different locations at the basins; taking into account the climatic and geomorphological factors, to understand water usage trends, analyse patterns, tap good shallow aquifers and ensure long lasting supplies of water through arid periods, mapping and modelling of groundwater are fundamental to problem resolution. Multivariate statistical techniques as well as cluster and principal component analysis were applied to the data on groundwater flow, with the objective of defining the main controls on the groundwater flows at the basins. These statistical techniques showed the presence of three groundwater flow groups with increasing importance according to precipitation. The first group was mainly influenced by climatic factors, the second was more controlled by the communication between the surface and underground flows and the third group revealed the influence of geomorphological factors on groundwater flows. 相似文献
15.
Environmental impact of the abandoned coal mines on the surface water and the groundwater quality in the south of Bochum,Germany 总被引：1，自引：1，他引：0
Surface water and groundwater samples were collected from 20 locations, situated in the vicinity of the abandoned coal mine fields south of Bochum. The main objective of this research is to assess the environmental impacts of these mines on the surface water and groundwater quality as well as to determine the factors controlling these impacts. The water samples were collected from stream sources, groundwater, surface water and engineered channels during April 2011. Physicochemical parameters were measured during fieldwork. Water samples were analysed for major ions and aluminium, iron, manganese, ferrous iron, zinc and hydrogen sulphide. The hydrochemistry of the surface water and the groundwater of this area is characterized by near-neutral to alkaline conditions, represented by predominance of calcium bicarbonate and sometimes calcium sulphate water types. Hence, the surface water and the groundwater quality in this region is significantly affected by abandoned coal mines. These effects resulted from oxidation of iron disulphide minerals that release iron, sulphate and hydrogen. The presence of carbonate-rich materials, which contained within the landfilling materials, has led the releasing of calcium, magnesium and bicarbonate. These materials could be the main source responsible for raising the alkalinity of the affected water. The environmental hazard of the abandoned coal mines in this area is related to the high concentration of Fe especially in the groundwater that possess the highest Fe concentration compared to other water sources: the Fe is 18 times larger than the allowed value in drinking water. Significant spatial variations of the water pollution were noted in this study. For this reason, the environmental hazards of the abandoned coal mines in Germany should be considered at closure of coal mines in the near future. Otherwise, these mines will be sources of environmental threats unless all necessary measures are taken to reduce their impact. 相似文献
16.
Oswaldo Eduardo Ramos Ramos Luis Fernando Cáceres Mauricio Rodolfo Ormachea Muñoz Prosun Bhattacharya Israel Quino Jorge Quintanilla Ondra Sracek Roger Thunvik Jochen Bundschuh Maria Eugenia García 《Environmental Earth Sciences》2012,66(3):793-807
Water management in semiarid and arid catchments such as the Poopó Lake Basin requires improved understanding of the complex behavior of the various contaminants, which affect the drinking water quality and considered as crucial for sustainable development of the region. Mechanisms of arsenic (As) release in the surface and groundwater were studied. Hydrochemical data for surface water (4 samples) and groundwater (28 samples) were collected in a small watershed in the Poopó catchment at the highland of the Bolivian Andes (Altiplano). All of them show high electrical conductivity values and moderately oxidizing conditions. The surface water contains high concentration of sulfate and the trace elements As, Zn and Pb in the zone affected by acid mine drainage. There is a large variability of the concentration of As and of the trace elements in the groundwater in the five different regions within the Poopó catchment. The metal concentrations sensitive to changes of redox state and results of speciation modeling suggest that As (V) is a predominant aqueous species, which conforms to the prevailing oxidizing conditions in the shallow groundwater environment. Two generalized trends for As distribution were identified in groundwater: (a) high concentrations are found in the arid zone (100–250 μg/L) in the southern (region III) and in the northwestern (region V) regions, and (b) low concentrations (<50 μg/L) are found in the remaining part of the basin (region I, II and IV). However, the spatial distribution within these regions needs to be investigated further. A conclusion from the present study is that there are multiple sources of As as well as other trace elements (such as Cd, Mn and Zn) in the Poopó Lake Basin. Among the sources and the processes which led to the mobility of As and other trace metals in the region are: (a) weathering of sulfide minerals, (b) oxidation of pyrite and/or arsenopyrite in mineralized areas and (c) desorption from hydrous ferric oxide (HFO) surfaces. In non-mining areas, volcanic ash is suggested to be a significant source of As. 相似文献
17.
18.
Wilson Yetoh Fantong Hiroshi Satake Festus T. Aka Samuel N. Ayonghe Kazuyoshi Asai Ajit K. Mandal Andrew A. Ako 《Environmental Earth Sciences》2010,60(1):107-120
Unplanned exploitation of groundwater constitutes emerging water-related threats to MayoTsanaga River Basin. Shallow groundwater
from crystalline and detrital sediment aquifers, together with rain, dams, springs, and rivers were chemically and isotopically
investigated to appraise its evolution, recharge source and mechanisms, flow direction, and age which were used to evaluate
the groundwater susceptibility to contamination and the basin’s stage of salinization. The groundwater which is Ca–Na–HCO3 type is a chemically evolved equivalent of surface waters and rain water with Ca–Mg–Cl–SO4 chemistry. The monsoon rain recharged the groundwater preferentially at an average rate of 74 mm/year, while surface waters
recharge upon evaporation. Altitude effect of rain and springs show a similar variation of −0.4‰ for δ18O/100 m, but the springs which were recharged at 452, 679, and 773 m asl show enrichment of δ18O through evaporation by 0.8‰ corresponding to 3% of water loss during recharge. The groundwater which shows both local and
regional flow regimes gets older towards the basins` margin with coeval enrichment in F− and depletion in NO3
−. Incidentally, younger groundwaters are susceptible to anthropogenic contamination and older groundwaters are sinks of lithologenic
fluoride. The basins salinization is still at an early stage. 相似文献
19.
《Chemie der Erde / Geochemistry》2023,83(1):125922
Life and the sustainable growth of socioeconomic sectors such as agriculture and industry depend on groundwater, particularly in arid and semi-arid regions where surface water resources are limited. The objectives of the current study are to characterize groundwater chemistry and assess its suitability for industrial usage in the Guanzhong Basin located in the semi-arid region of northwest China. To better understand the hydrogeochemistry in the study area, statistical analysis, ionic plots and Pearson's correlation analysis were conjunctively used. Finally, a novel industrial water quality index (IndWQI) model was developed in this paper to determine the overall industrial water quality based on scaling, corrosion, and foaming coefficients as well as some physicochemical parameters. The contribution of each parameter to the overall industrial water quality was determined using multivariate statistical analysis approaches. The findings reveal that dissolution of minerals such as calcite, dolomite, anhydrite and gypsum regulate the groundwater geochemistry in the study area. In addition, human activities influence the groundwater quality in the study area. According to the novel IndWQI approach, 78.95 % of the confined water samples and 74.51 % of the phreatic water samples have excellent or good quality, and can be safely used for industrial boilers. The geospatial analysis shows that the most contaminated groundwater samples are mainly located in northeast Xi'an and the northeast region of the Guanzhong Basin. The IndWQI model is trustworthy, as it can combine several water quality indices and give an instantaneous impression of the whole groundwater quality for industrial uses. It can serve as a benchmark for other areas across the world with a comparable climate. 相似文献
20.
金矿含氰废水中氰化物的降解方法 总被引：2，自引：0，他引：2
陈德友 《华北地质矿产杂志》1999,(2)
含氰废水的排放造成严重的环境污染,处理废水中的氰化物具有重要的实际意义,特别是对采用氰化法提金的黄金矿山尤为重要。本文系统介绍了国内外处理含氰废水中氰化物的几种应用效果较好的方法,阐述其原理、工艺流程等,并对其处理效果作了具体比较。 相似文献