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1.
在分析矿区地形地貌、地层岩性、水文地质条件和影响排土场稳定因素的基础上,结合区内2#排场的监测资料,采用FLAC3D模拟软件和刚体极限平衡法中的毕肖普条分法,对排土场边坡变形、破坏的主要影响因素进行了分析,揭示了其滑坡机理;对3#排土场的稳定性做出预测,认为排土场边坡变形破坏模式是上部排弃物沿圆弧滑面剪切滑移与下部沿粉土、粉质粘土平面滑移的圆弧—平面组合滑移形式;基底土层的内摩擦角对排土场允许排高较为敏感,是决定允许排高的内在因素,基底粉质粘土的极限承载力是决定排土场允许排高的外在因素;基底土体极限承载力所决定的排土场的允许排高为90.60～91.60m。提出了填沟压脚、降低第一排台阶高度和基底排水等措施来满足排土场边坡稳定的要求。 相似文献
2.
煤矸石山周围地下水污染状况 总被引：3，自引：0，他引：3
以焦作市演马矿煤矸石山为对象,采集该处新鲜和风化煤矸石以及附近地下水样品,检测其中Cl-、SO2-4、苯并(a)芘、Mn等22种污染物的含量,并采用超标倍数法和实测浓度法对地下水受污染状况进行分析研究。地下水中污染物含量与煤矸石山距离呈负相关,且在丰水期和枯水期存在一定差异。 相似文献
3.
对于人为因素或自然因素造成的农田土壤重金属元素污染,需要进行大面积的土壤环境质量调查和分类管控,然而传统的采样测试方法存在工作量大、代价高等问题。可见—近红外（Vis-NIR）反射光谱是一种快速低成本获取土壤理化信息的手段。为研究Vis-NIR反射光谱预测模型划分土壤重金属污染风险类别的能力,文章以典型人为污染地区（浙江温岭）和典型地质高背景地区（广西横县）的390份农田土壤为样本,测定8种重金属元素（As、Cd、Cr、Cu、Hg、Ni、Pb和Zn）的含量和pH值,并测定土壤Vis-NIR光谱。使用偏最小二乘（PLS）和支持向量机（SVM）算法建立回归模型,对土壤重金属含量和pH值进行预测,并基于预测值进行土壤重金属污染风险分类。结果显示,温岭土壤主要污染元素Cd和Cu的光谱模型回归预测偏差（RPD）分别为1.23和1.19,预测机制与有机质有关。横县土壤主要污染元素As和Cd的RPD分别为1.98和1.93,预测机制与铁氧化物和粘土矿物有关。地质高背景土壤重金属与铁氧化物的正相关性普遍较强,使得光谱模型对重金属含量预测准确度较高。温岭和横县土壤pH值的光谱模型RPD分别为1.76和1.68。土壤重金属污染风险光谱分类的总体
准确度分别为75.0%~100%（温岭）和80.0%~100％（横县）。将Vis-NIR光谱与遥感技术相结合,对农田土壤重金属污染风险进行快速分类总体是可行的。 相似文献
4.
C. P. Zhang P. Wu C. Y. Tang H. H. Xie Z. C. Zeng S. Z. Yang 《Environmental Earth Sciences》2014,71(10):4341-4351
The sediment from an acid mine drainage affected reservoir of Guizhou province of China has the iron and arsenic concentration of about 400 and 2.6 g/kg, respectively. Sediment cores were collected, and were used to study the arsenic behavior in the seriously acidified reservoir from the viewpoint of chemical thermodynamics. The limestone neutralization and ferric iron hydrolysis regulated the porewater pH from about 2.9–5.8. The reductive dissolution of As–Fe-rich (hydr)oxides under the mild acidic conditions was the main mechanism for the release of absorbed arsenic into porewater. The maximum concentrations of iron, sulfate and arsenic reached to about 2,800, 9,000 and 1 mg/l, respectively. Arsenic speciation transformation and hydrous ferric oxide (HFO) crystallization enhanced the arsenic mobility in sediment. In addition, the iron sulfide minerals diagenesis could play a role in removing the dissolved arsenic from porewater. The actual distribution of arsenic concentration in porewater was well simulated using the model of surface complexation of arsenic to HFO. Although arsenic concentration in porewater could be above 100 times higher than that of reservoir water, it was not easy to release into the reservoir water through diffusion, because the shallow sediment had relatively strong arsenic adsorption capacity, and new HFO could be generated continuously at the sediment water interface. 相似文献
5.
对我国产出的铀酰砷酸盐矿物的矿物学特征、形成环境和环境矿物学意义进行了较系统的综合论述。铀酰砷酸盐矿物是主要产出于铀矿床氧化带中比较特征的黄绿色表生矿物，是寻找原生铀矿床(体)的重要矿物学标志，化学组成主要是[AsO4]^3-和[UO2]^2 ，其中As和U均是对环境造成极大危害的有毒或放射性有害元素。As、U的地球化学性质十分活跃，在不同的酸、碱和氧化还原介质环境中的分解、迁移能力均很强，在矿床氧化带中的分解、迁移扩散会对矿区周围及其下游地区造成较大范围的严重环境污染。而在弱酸性至中性介质条件下，[AsO4]^3-和[UO2]^2 结合并与各种金属阳离子化合可形成相对稳定的铀酰砷酸盐矿物，由此可在一定程度上减少U、AS的迁移扩散及其对环境的危害。 相似文献
6.
Mahboobeh Tayebi Mehdi Naderi Jahangard Mohammadi Mohammad H. Tayebi 《Environmental Earth Sciences》2017,76(21):734
Two statistical models including partial least squares regression (PLSR) and principal component regression were comparatively utilized to determine the predictive accuracy of visible–near-infrared and short-wave infrared reflectance spectroscopy in quantifying the Fe concentration in contaminated soils. Two scenarios were applied to select the best model: Scenario I included all wavelengths (400–2450 nm) and Scenario II encompassed characteristic bands of Fe. Pre-processing techniques used to select the best model included: first and second derivatives (FD and SD), multiplicative scatter correction (MSC) and standard normal variate. The abilities of the predictive models were evaluated by splitting soil samples into two random groups (80 and 20%). The first group (80%) was used to evaluate calibration and validation sets by employing the cross‐validation method, and the second group (20%) was applied to test the models. The coefficient of determination (R 2), root mean square error and residual prediction deviation were calculated to evaluate the models. Applying Scenario I indicated that the PLSR model with SD pre-processing was a more accurate technique for predicting the Fe concentration, whereas in the Scenario II, the PLSR model with MSC pre-processing had a better performance. Comparing Scenarios I and II indicated that the more reliable models for predicting the soil Fe content could be constructed by the PLSR model with the SD pre-processing techniques and all wavelengths. The modeling results produced by the PLSR model with the SD pre-processing could be used to detect, map and monitor Fe-contaminated soils by proximal and remote sensing in the mining areas. 相似文献
7.
A combined mathematical geophysical model for prediction of pyrite oxidation and pollutant leaching associated with a coal washing waste dump 总被引：3，自引：0，他引：3
F. Doulati Ardejani Ph.D. B. Jodieri Shokri M.Sc. A. Moradzadeh Ph.D. E. Soleimani Ph.D. M. Ansari Jafari Ph.D. 《International Journal of Environmental Science and Technology》2008,5(4):517-526
The waste produced by coal washing process produces many environmental problems. In this study, the pollution problems associated with the waste produced by Alborz Sharghi Coal Washing Plant was investigated by mathematical modeling. The study area is located at 11 km. to Razmjah coal region and 45 km. to Tehran-Mashhad road in the north part od Iran. To achieve the goal, a few samples were taken from different depths at three points on the waste dump in order to investigate pyrite oxidation and pollution generation. The samples were then analysed, using an AA-670 Shimadzu atomic absorption to determine the fraction of pyrite remained within the waste particles. A numerical finite volume model using Phoenics package has been developed to simulate pyrite oxidation and pollution generation from the Alborz Sharghi coal washing waste dump. The pyrite oxidation reaction is described by the shrinking-core model. Gaseous diffusion is the main mechanism for the transport of oxygen through the waste. The results of numerical modelling were compared with the field observations and close agreement was achieved. A simple mathematical model incorporating advection and hydrodynamic dispersion processes was also presented in order to verify the results of geophysical time-laps method showing transportation of the pollutants through the downstream of the waste dump. Both mathematical model and geophysical time-laps method are agreed in the identification of pollutant transport emanated from the waste dump. The results of such investigations can be used for designing an effective environmental management program. 相似文献
8.
富铯矿物及其在核废物地质处置上的意义 总被引：1，自引：0，他引：1
自然界中最常见的铯矿物主要有铯沸石、富铯的云母类矿物和富铯的绿柱石类矿物,它们产于稀有金属花岗岩和LCT(Lithium-Cesium-Tantalum)型稀有金属伟晶岩脉体的中心部位或围岩接触带附近,形成于初始富含铯和挥发组份、处于稳定构造环境且经过高度演化分异的原始花岗质岩浆.由于天然富铯矿物中铯含量一般可达15%,它们的合成相可作为核废料中放射性元素137Cs的前景载体相,而且富铯矿物各自的化学成分和结构等矿物学特征,对137Cs核废物载体相及相应的深埋藏地质环境的选择和载体相在不同地质环境下的行为预测都有较好的指导意义. 相似文献
9.
Environmental mercury and arsenic sources in fossil hydrothermal systems, Northland, New Zealand 总被引：2，自引：0，他引：2
Northland, New Zealand has been affected by natural hot water spring systems depositing elevated concentrations of mercury
and arsenic over the past 5 million years. Due to the different erosion levels of these hot water systems, four principal
types of mercury and arsenic occurrences are found: active hot springs; layered surface deposits (sinters) deposited by hot
springs; highly fractured rock zones formed immediately beneath hot springs; and chemically altered and mineralized rock from
the deeper roots of hot spring systems. Mercury occurs principally as cinnabar and as a minor impurity (<1 wt%) in phosphate
minerals and iron sulfides, particularly marcasite. Mercury is irregularly distributed through limonitic cements formed during
oxidation. Arsenic occurs as a minor impurity (<1 wt%) in phosphate minerals and iron sulfides, particularly marcasite. Arsenic
is also variably dispersed through limonite, but not necessarily with mercury. Decomposition of marcasite constitutes the
most significant source of mercury and arsenic pollution from the studied sites. Release of mercury and arsenic into the environment
from marcasite, phosphates and limonite is enhanced by acidification of the sites (down to pH of 2), caused by oxidation of
iron sulfides. Mercury and arsenic concentrations of up to 100 parts per billion should be expected in waters near the deposits;
these concentrations are in excess of recommended drinking water levels.
Received: 9 April 1999 · Accepted: 2 August 1999 相似文献
10.
为了监测复垦矿区土壤的有机质含量, 综合利用光谱分析、统计学习理论与方法以及智能优化理论与方法, 研究了矿区复垦土壤有机质含量与土壤光谱之间的关系, 在此基础上建立了土壤有机质含量高光谱反演模型, 实现土壤有机质含量定量检测.首先对原始土壤光谱数据进行预处理, 然后进行相关性分析, 提取450 nm、500 nm、650 nm、770 nm、1 460 nm和2 140 nm作为特征波段, 最后利用多元线性回归(multiple linear regression, MLR)、偏最小乘回归(partial least squares regression, PLSR)和粒子群优化支持向量机回归(particle swarm optimization support vector machine regression, PSO-SVM)方法建立了土壤有机质含量的高光谱定量反演模型, 并对模型进行验证.3种模型的验证结果如下: MLR、PLSR和PSO-SVM模型的R2分别为0.79、0.83和0.85, RMSE分别为5.26、4.93和4.76.实验结果表明, 无论从模型的稳定性还是预测能力上, PSO-SVM都要优于其他两个模型. 相似文献
11.
Distribution and environmental impact of coal-mining wastes in Upper Silesia, Poland 总被引：8，自引：0，他引：8
About 50 million tonnes/year of waste rock from coal-mining is generated in the limited area of the thickly populated Upper
Silesian Coal Basin (USCB) in Poland. There are 380 coal-mining waste dumps, including 76 active dump sites covering over
2,000 ha. About 15-16 million tonnes/year of waste rock is being reused for civil engineering purposes in the same area. This
brings about a problem of ground water deterioration by constituents leached from waste rock exposed to atmospheric conditions.
The major factors determining the ground water contamination potential from waste rock are chloride salinity, sulfur content
and acid generation potential. The concept behind the presented studies was to provide data for correct evaluation and prediction
of contaminant release from the waste rock, based on the characterization of coal-mining waste properties, as well as on long-term
laboratory, lysimetric and field studies. The results show that coal-mining waste dumps can be a long-term source of ground
water contamination, lasting for decades and increasing with time. Ground water down-gradient from the disused 15–30-years-old
part of the studied dump displays high and increasing acidification, high TDS, SO4, and the highest, still increasing concentrations of Mn, Fe and Zn. Cost-effective and efficient pollution control measures,
similar to the presented design and construction elements of the dump site, can mitigate the negative environmental impacts.
Received: 3 July 1997 · Accepted: 9 September 1998 相似文献
12.
Soil, mine tailing, and waste dump profiles above three mesothermal gold deposits in the Bohemian Massif with different anthropogenic histories have been studied. Their mineralogical, major element, and arsenic (As) contents and the contents of secondary arsenic minerals were analyzed. The As-bearing minerals were concentrated and determined using X-ray diffraction (XRD) analysis, the Debye-Scherrer powder method, scanning electron microscopy (SEM), and energy-dispersive microanalysis (EDAX). The amorphous hydrous ferric oxides (HFO), As-bearing goethite, K-Ba- or Ca-Fe- and Fe- arsenates pharmacosiderite, arseniosiderite, and scorodite, and sulfate-arsenate pitticite were determined as products of arsenopyrite or arsenian pyrite oxidation. The As behaviour in the profiles studied differs in dependence on the surface morphology, chemical and mineralogical composition of the soil, mine wastes or tailings, oxidation conditions, pH, presence of (or distance from) primary As mineralization in the bedrock, and duration of the weathering effect. Although the primary As mineralization and the bedrock chemical composition are roughly similar, there are distinct differences in the As behaviour amongst the Mokrsko, Roudný and Kaperské Hory deposits. 相似文献
13.
The basin-fill aquifers of the Western U.S. contain elevated concentrations of arsenic in the groundwater due to ancient volcanic deposits that host arsenic minerals. Microcosms were constructed using two oxidized sediments and, by contrast, a reduced sediment collected from a shallow basin-fill aquifer in the Cache Valley Basin, Northern Utah to evaluate the fate of geologic arsenic under anoxic conditions. Sequential extractions indicated the primary arsenic host mineral was amorphous iron oxides, but 13%–17% of the total arsenic was associated with carbonate minerals. Arsenic was solubilized from the sediments when incubated with groundwater in the presence of native organic carbon. Arsenic solubilization occurred prior to iron reduction rather than the commonly observed co-reactivity. Arsenic(V) associated with carbonate minerals was the main source of arsenic released to solution and redistributed onto less soluble minerals, including FeS and siderite as defined by chemical extraction. Arsenic reduction occurred only in the site-oxidized sediments. The addition of a carbon and energy source, glucose, resulted in enhanced arsenic solubilization, which was coupled with iron reduction from the site-oxidized sediments. Adding glucose promoted iron reduction that masked the role of carbonate minerals in arsenic solubilization and retention as observed with incubation with groundwater only. 相似文献
14.
Water resources near a gold-mine waste site were studied for the distribution and contents of contaminants, and their behavior
in the surface and groundwater systems. Arsenic, cadmium, and manganese were identified with levels exceeding the drinking
water guidelines of WHO (World Health Organization), and their distribution depended upon the differences in source materials
and in spatial pH variations. Originating from arsenopyrite, concentrations of dissolved arsenic were controlled by sorption
with amorphous iron (Fe(OH)3) and carbonate minerals. Cadmium and manganese were derived from the mineral phase including sphalerite (ZnS), otavite (CdCO3), and rhodochrosite (MnCO3); their concentrations in water resources were limited by the solubility of mineral phases. All of these processes are significantly
pH-dependent, implying that a small decline in pH could result in a drastic increase in contaminant concentrations and become
a pollution threat to the water resources of the Gubong area.
Received: 13 December 1999 · Accepted: 21 March 2000 相似文献
15.
The behavior of arsenic and antimony at Pezinok mining site,southwestern part of the Slovak Republic
Renata Flakova Zlatica Zenisova Ondra Sracek David Krcmar Ivana Ondrejkova Martin Chovan Bronislava Lalinská Miriam Fendekova 《Environmental Earth Sciences》2012,66(4):1043-1057
Arsenic and antimony contamination is found at the Pezinok mining site in the southwest of the Slovak Republic. Investigation of this site included sampling and analysis of water, mineralogical analyses, sequential extraction, in addition to flow and geochemical modeling. The highest dissolved arsenic concentrations correspond to mine tailings (up to 90,000 μg/L) and the arsenic is present predominately as As(V). The primary source of the arsenic is the dissolution of arsenopyrite. Concentration of antimony reaches 7,500 μg/L and its primary source is the dissolution of stibnite. Pore water in mine tailings is well-buffered by the dissolution of carbonates (pH values between 6.6 and 7.0) and arsenopyrite grains are surrounded by reaction rims composed of ferric iron minerals. Based on sequential extraction results, most solid phase arsenic is in the reducible fraction (i.e. ferric oxyhydroxides), sulfidic fraction, and residual fraction. Distribution of antimony in the solid phase is similar, but contents are lower. The principal attenuation mechanism for As(V) is adsorption to ferric oxide and hydroxides, but the adsorption seems to be limited by the competition with Sb(V) produced by the oxidation of stibnite for adsorption sites. Water in mine tailings is at equilibrium with gypsum and calcite, but far from equilibrium with any arsenic and antimony minerals. The concentrations of arsenic and antimony in the surrounding aquifer are much lower, with maximum values of 215 and 426 μg/L, respectively. Arsenic and antimony are transported by ground water flow towards the Blatina Creek, but their loading from ground water to the creek is much lower compared with the input from the mine adits. In the Blatina Creek, arsenic and antimony are attenuated by dilution and by adsorption on ferric iron minerals in stream sediments with resulting respective concentrations of 93 and 45 μg/L at the site boundary south of mine tailing ponds. 相似文献
16.
秦岭卡林型金矿床金、砷地球化学探讨 总被引：16，自引：0，他引：16
讨论了秦岭卡林型金矿床中Ａｕ 、Ａｓ 的元素地球化学、矿物学特征。在含矿岩系中获得的Ａｕ、Ａｓ 等成矿元素初始含量较高,且主要集中在成岩黄铁矿中。在矿石样品中对含砷硫化物矿物的研究表明,Ａｕ 、Ａｓ 在矿物显微结构中具有强的正相关性。在大量金进入到硫化物结构之前,就已有［ＡｓＳ］３ － 的存在。在含砷硫化物矿物中,金多半以一种带电类型（Ａｕ３ ＋） 存在, 它很可能替代铁位置上的过剩砷, 以固溶体方式沉淀于硫化物矿物中。此时, 黄铁矿构成（Ａｕ３ ＋ ,Ｆｅ２ ＋）（［ＡｓＳ］３ － ［Ｓ２］２ － ）,毒砂构成（Ａｕ３ ＋ ,Ｆｅ２ ＋）（［ＡｓＳ］３ － ［ＡｓＳ］３ －） 。通过电子探针（ＥＭＰ） 和透射电镜（ＴＥＭ） 对秦岭卡林型金矿含砷硫化物矿物中金的赋存状态的研究表明,在金的成矿作用早期阶段, 金主要以固溶体形式优先富集于含砷黄铁矿和毒砂及砷黝铜矿之中,并且认为是以金的氧化和砷的还原的共沉淀方式发生的。在此之后的金成矿作用晚期阶段,由于热液蚀变和结晶作用程度的增高,寄主矿物耐熔性质相对降低,加之金本身的聚集能力,和因过量砷加入而造成的含砷硫化物矿物的晶格缺陷,致使已形成的固溶体金以“出溶”形式发生再分布,赋存于硫化物矿物晶粒 相似文献
17.
土壤环境中砷元素的生态效应 总被引：1，自引：0，他引：1
论述了各环境介质中砷元素的分布特点,指出土壤第Ⅱ环境中的砷主要来源于人为活动。砷主要富集于土壤表层,且主要以稳定矿物形式存在;但当土壤砷总量高时其可溶性砷量亦相应高,砷在土壤中易形成Fe、Al、Ca型砷化物而被固定;当土壤pH值增高至中性或碱性时,砷易转化为迁移能力更强、毒性更大的三价砷。砷对作物、人体生态系统危害作用明显,砷通过蔬菜对人体的危害甚于谷物,应采取有效措施防治土壤中砷污染。 相似文献
18.
The effects of goethite on the anaerobic bio-decomposition of sulfate minerals were investigated by using the beef extract
as a carbon source and the activated sludge as the source of mixed bacteria. Solution pH, sulfate concentration, total iron
ion concentration and the solid products of four different batch tests were monitored and analyzed. Experimental results showed
that the presence of iron oxide can improve the alkalinity of the reaction system which results in the increase of pH value.
Moreover, the added goethite consumed a large amount of H2S generated from the sulfate minerals by SRB, thereby significantly enhancing the decomposition of gypsum and anhydrite compared
with the control batch tests. In addition, the SEM observation and the EDS spectra showed that there were some rod-shaped
microorganisms and new generated minerals, such as iron sulfide, calcium carbonate crystals, and elemental sulfur. Both of
the proliferation of new minerals (iron sulfide and calcium carbonate crystals) and the complete disappearance of sulfate
minerals indicated that iron oxide can play the role in fixing the S element through the metabolism of SRB and hence improve
the bio-decomposition of sulfate minerals. 相似文献
19.
During stabilization or demobilization of contaminants in solid waste materials, different approaches can be taken, which also can be combined: (1) sufficient long-term buffer capacity can be provided, according to the environmental conditions; (2) permeability for dissolved contaminants can be reduced by secondary mineral precipitations or by soft gels injected into the pore space of the waste body; and (3) new formations of ‘reservoir minerals' can incorporate potential pollutants in their internal structure. Emphasizing the geochemical engineering approach, two examples are presented from the field of water management, both focussing on the demobilization of arsenic species. The first example (after Driehaus, W., 1994. Arsenentfernung mit Mangandioxid und Eisenhydroxid in der Trinkwasseraufbereitung. Vol. 133, Ser. 15, VDI-Reports, Düsseldorf, 117 pp.) relates to the problems during purification of arsenic-rich raw water, suggesting the potential application of iron and manganese oxide minerals as oxidizing agents and mineral lattice structures for the elimination of arsenic. In the second example, contaminated sludges from water treatment plants were investigated for their leaching characteristics and long-term stability. A pH-stat test procedure was used to assess the leaching characteristics of metals at typical pH values. Due to the presence of iron and manganese oxides pentavalent arsenic is protected against conversion into the mobile trivalent form at neutral to low pH. Experimental data suggest that co-disposal with reducing organic matter and alkaline stabilization material or wastes could negatively influence the binding properties and, therefore, should be avoided. 相似文献