Qualitative analysis and mapping of heavy metals in an abandoned Au–Ag mine area using NIR spectroscopy

Reflectance spectroscopy covering the visible and near-infrared ranges (400–2,400 nm) is known as a rapid and nondestructive method in the characterization and quantitative analysis of many components of interest. In this study, the potential use of spectral absorption feature parameters (SAFPs) in the range of 400–2,400 nm was investigated in terms of the prediction of heavy metals and mapping of their distribution. Parameters such as absorption depth, area, and peak ratio were derived from variations in spectral absorption shape associated with concentrations of heavy metals. Heavy metals were quantified from SAFPs using stepwise multiple linear regression (SMLR) and enter multiple linear regression (EMLR). The EMLR model showed qualitative prediction performance for As and Cu, with R ² values of 0.60 and 0.81, respectively. A contour map of As and Cu concentrations based on EMLR-derived values showed similar spatial patterns to a map based on measured values.     

Mobilization of Ag,heavy metals and Eu from the waste deposit of the Las Herrerias mine (Almería,SE Spain)

We studied the mobility of silver, heavy metals and europium in waste from the Las Herrerías mine in Almería (SE Spain). The most abundant primary mineral phases in the mine wastes are hematite, hydrohematite, barite, quartz, muscovite, anorthite, calcite and phillipsite. The minor phase consisted of primary minerals including ankerite, cinnabar, digenite, magnesite, stannite, siderite and jamesonite, and secondary minerals such as glauberite, szomolnokite, thenardite and uklonscovite. The soils show high concentrations of Ag (mean 21.6 mg kg^–1), Ba (mean 2.5%), Fe (mean 114,000 mg kg^–1), Sb (mean 342.5 mg kg^–1), Pb (mean 1,229.8 mg kg^–1), Zn (mean 493 mg kg^–1), Mn (mean 4,321.1 mg kg^–1), Cd (mean 1.2 mg kg^–1) and Eu (mean 4.0 mg kg^–1). The column experiments showed mobilization of Ag, Al, Ba, Cu, Cd, Eu, Fe, Mn, Ni, Sb, Pb and Zn, and the inverse modelling showed that the dissolution of hematite, hausmannite, pyrolusite and anglesite can largely account for the mobilization of Fe, Mn and Pb in the leaching experiment. The mobility of silver may be caused by the presence of kongsbergite and chlorargyrite in the waste, while the mobility of Eu seems to be determined by Eu(OH)₃, which controls the solubility of Eu in the pH–Eh conditions of the experiments. The mineralogy, pH, Eh and geochemical composition of the mine wastes may explain the possible mobilization of heavy metals and metalloids. However, the absence of contaminants in the groundwater may be caused by the carbonate-rich environment of “host-rocks” that limits their mobility.     

Distribution Characteristics and Influencing Factors of Heavy Metals in Pearl River Delta Quaternary Boreholes

This paper analyzed contents and geochemical fractions of four heavy metals in four Quaternary boreholes from different sedimentary areas in Pearl River Delta. The results revealed that the geochemical features of heavy metals were controlled by geological provenance and sedimentary environment. The contribution rates of geological sources showed differentiation in four sedimentary environments. In delta plain sedimentary environment, geological sources were the most predominant. In the sea land interaction sedimentary environment, the control of the geological source factor was weakened. The effect of land-sea interaction became more important. Due to different chemical properties of heavy metals, they showed distinct sensitivities to sedimentary environment. Cadmium (Cd) was enriched significantly in the study areas. Mobile fraction of Cd possessed the highest proportion. Potential ecological risk of Cadmium was the highest among heavy metals. Asenic, mercury and lead were enriched weakly. Arsenic and Mercury were dominated by residual fraction. Lead was mainly composed of residual and Fe-Mn oxidation fraction. Their potential ecological risks were relatively lower. In different sedimentary environment, physicochemical parameters had various effects on Cadmium geochemical fraction such as pH. The mobile fraction of Cd was mainly correlated with pH and leaching coefficient.     

TRMM/PR资料在中尺度模式中的应用

将中尺度非静力模式MM5中的积云参数化Grell方案作了改进,使它含液态水含量,并用该模式对1998年6月29日08：00～30日08：00(北京时,下同)和7月1日08：00～2日08：00发生在淮河流域的两次特大暴雨进行数值模拟研究,同时通过采用不同高度上的Z—qr关系式将TRMM／PR(Tropical Rainfall Measuring Mission／Precipitation Radar)雷达得到的反射率资料计算出比含水量qr,然后用qv=qv qr取代原模式中的比湿qv。结果表明,将TRMM／PR雷达资料加入模式后,由于PR雷达具有较高的空问分辨率,能够很好地反映中小尺度系统的空间结构,使湿度值接近实际,缩短了中尺度系统的发展时间,使得模拟出来的降雨强度、雨量中心位置以及雨带形状更接近实况。     

武汉地区少梅年一次局地强降水中尺度系统 特征的分析

2000年以来长江流域未见到很典型的梅雨暴雨,尽管如此,所谓"不典型"的区域性致洪暴雨仍时有发生,甚至造成严重洪涝。利用NCEP资料、常规和SCHeREX计划期间的6h一次的高空探测资料和大量的地面自动站资料、多普勒雷达、FY-2C卫星黑体温度资料及NOAA的CMORPH资料,分析了2009年6月29日00:00(协调世界时,下同)至30日00:00引发武汉严重洪涝的强降水。结果表明,尽管中高纬环流和槽脊系统有"错位"现象,但东亚地区鞍形场的存在有利于高原东侧中尺度低压(扰动)的发生发展。随着高原槽东移和西太平洋副热带高压突然西伸,在四川—重庆地区诱生出中尺度涡旋及明显的低空急流,同时上层冷干、下层暖湿空气叠置而形成较强的位势不稳定层结,在低层辐合场的触发下,使致洪暴雨得以发生。该年有较好的水汽输送条件,主要源地在南中国海。因此,即使在大尺度环流不是非常"典型"的情况下,一旦武汉地区存在有利的天气尺度和中尺度系统,且有足够的水汽供应,暴雨仍有可能发生。     

密云某流域土壤重金属污染特征及评价

对北京市密云水库上游某流域周边土壤重金属(As、Hg、Zn、Cu、Cd、Pb、Ni、Cr)的空间分布、来源及污染现状进行评价。地累积指数法、单因子指数与内梅罗综合污染指数法、多元统计分析(相关性分析、主成分分析)表明,Cu、Pb、Zn、Cd和As五种元素主要来源于矿山开采、选矿以及运输等过程;Cr和Ni污染主要来源于旧金属垃圾及铁矿开采伴生元素;Hg元素污染主要来自于金矿的采选过程。Cr元素在该流域内污染比例较大,Hg与Cd两种元素变异程度较大,污染较为严重的区域主要集中在金矿和尾矿库附近。Pb和As两种元素污染程度处于相对安全水平。     

西藏波密县天摩沟“9·4”特大泥石流灾害成因初步分析

从地貌地质环境、地面气象要素、大气环流背景、T213数值预报产品和卫星资料等方面,着重分析诱发灾害的气象条件,对2007年9月4日西藏波密县古乡天摩沟发生的一次特大泥石流地质灾害事件成因进行初步分析。结果表明：由于前期气温持续偏高,加剧冰川融水,加上9月4日凌晨出现强降水,天摩沟地形高度落差大、松散固体物质丰富,水源、能量转化和物源三种条件同时满足^[1],是造成这次特大泥石流地质灾害的直接原因。     

The transport of heavy metals during flood events in the polluted river Geul (the Netherlands)

For a specific flood on the polluted River Geul in March 1988, the relationships between river discharge, sediment concentration, and associated metal levels have been investigated. It was found that river discharge has only a limited influence on the transport of sediment and Pb, Zn, and Cd. During flood peaks its role is prominent, but at the intermediate stages between peaks, the quantity and quality of transported sediment depend on the variable activity of various sediment sources upstream. Nevertheless, when data from more floods are assembled, sediment and metal rating curves are obtained, which provide correlation coefficients of 0-63-0-92. Using these curves, mass transport calculations were carried out which demonstrate that the bulk of the annual transport of sediments and heavy metals occurs during a limited number of major floods.     

基于遗传算法的暴雨强度公式参数的优化

遗传算法是模型参数优化的一种有效方法。将遗传算法应用于北京市郊区不同重现期的暴雨强度与降雨历时关系式中参数的优化,并与传统回归法和优选回归法的优化效果进行了分析比较。实例计算结果表明：遗传算法用于暴雨强度公式中的参数估计精度高于传统回归法和优选回归法的参数估计精度。该方法具有直观、简便和实用特点。     

Distribution of heavy metals in Gaborone urban soils (Botswana) and its relationship to soil pollution and bedrock composition

The capital city of Botswana, Gaborone, has seen unprecedented population, economic, and industrial growth in recent years. In order to assess how this rapid urbanisation process impacts the environment, 106 silt and clay (particle size <0.053 mm) samples, separated from Gaborone surface soil samples representing urban, agricultural and rural sites, were investigated. The concentrations of nine heavy metals (Sc, Cr, Co, Ni, Cu, Zn, Nb, Cd, and Pb) were measured using ICP–MS and GFAAS, and the resulting patterns were correlated to the bedrock composition and anthropogenic activities. As expected, we found that samples from soils on top of dolerites show higher levels of Cr, Ni, and Cu than those on top of granites and rhyolites. However, our studies also show that Gaborone city centre soils are moderately polluted by Pb (up to 222 mg/kg, i.e. 5.7-fold the concentration in comparable rural soils), as a result of heavy traffic. Furthermore, Cr and Ni pollution originating from agrochemicals were shown to be accumulating in Gaborone crop soils. Our studies also showed moderate levels of Zn pollution and low level, dot-shaped pollution of Cr, Co, Ni, Cu detected in Gaborone residential and industrial soils that are correlated to waste disposal. Interestingly, the highest levels of Sc, Cr, Co, Ni and Zn pollution are found near two abandoned sewage works. The results of sequential extraction indicate that the polluting Co and Ni exist in all speciations; the polluting Cu mainly exists in the residue of the sequential extraction, whereas the polluting Pb is mostly bound to organic matters and Fe- and Mn-oxides. These results highlight the need for instituting a systematic and continuous monitoring of heavy metals and other forms of pollutants in Gaborone to ensure that pollution does not become a serious problem in the future.