MODELING METALS TRANSPORT AND SEDIMENT/WATER INTERACTIONS IN A MINING IMPACTED MOUNTAIN STREAM1

ABSTRACT: The U.S. Environmental Protection Agency (USEPA) Water Quality Analysis Simulation Program (WASP5) was used to model the transport and sediment/water interactions of metals under low flow, steady state conditions in Tenmile Creek, a mountain stream supplying drinking water to the City of Helena, Montana, impacted by numerous abandoned hard rock mines. The model was calibrated for base flow using data collected by USEPA and validated using data from the U.S. Geological Survey (USGS) for higher flows. It was used to assess metals loadings and losses, exceedances of Montana State water quality standards, metals interactions in stream water and bed sediment, uncertainty in fate and transport processes and model parameters, and effectiveness of remedial alternatives that include leaving contaminated sediment in the stream. Results indicated that during base flow, adits and point sources contribute significant metals loadings to the stream, but that shallow ground water and bed sediment also contribute metals in some key locations. Losses from the water column occur in some areas, primarily due to adsorption and precipitation onto bed sediments. Some uncertainty exists in the metal partition coefficients associated with sediment, significance of precipitation reactions, and in the specific locations of unidentified sources and losses of metals. Standards exceedances are widespread throughout the stream, but the model showed that remediation of point sources and mine waste near water courses can help improve water quality. Model results also indicate, however, that alteration of the water supply scheme and increasing base flow will probably be required to meet all water quality standards.     

DECLINING INTENSITY OF ACID MINE DRAINAGE IN THE NORTHERN APPALACHIAN BITUMINOUS COAL FIELDS: MAJOR ALLEGHENY RIVER TRIBUTARIES1

ABSTRACT: For more than 30 years, a program of continuous monitoring of pH, acidity, alkalinity, and other parameters has been maintained on a network of large streams degraded by acid mine drainage in the northern Appalachian high sulfur coal region. Continuous records since 1952 are available at a number of stations, and at several stations, acidity records date back to 1930. Comparable analysis techniques were maintained over the period of record, assuring the long term continuity of the database. This monitoring program has captured integrated long term trends within large and complex watersheds with numerous and varied types of mine discharges. The focus of this paper is a historical trend analysis of lightly to severely acid degraded major tributaries of the Allegheny River. Over the past three decades, all of the Allegheny River drainage basin stations have demonstrated steady and substantial declines in acidity and associated increases in pH and alkalinity. The average recorded decline in total acidity at four stations monitored since the 1950s was 94 percent. Since the 1970s, acidity declined by an average of 63 percent at 10 stations. Oxidative exhaustion of pyritic minerals exposed by mining is proposed as a major factor influencing these trends.     

How has a shortage of census and geological information impeded the regularization of artisanal and small‐scale mining?

There is growing consensus that a combination of laissez‐faire policies, ad hoc regulation and debilitating support services has perpetuated socio‐economic and environmental deterioration in the artisanal and small‐scale mining (ASM) industry. However, a lack of anthropological and geological information on ASM prevents many governments both from improving the policy environment of the industry, and from providing more robust extension services to its operators. This article aims to examine more precisely how a deficiency of baseline census and geological data has inhibited industry formalization and undermined many of the measures implemented to address pressing problems at ASM sites. Specifically, it is argued that insufficient knowledge of artisanal mining populations — including their demographic structure — and of areas suitable for ASM activities affects the ability of a government to regularize, as well as to improve, the organization of this largely informal sector of industry. Case studies of Ghana and Zimbabwe are used to illustrate how the undertaking of low‐budget projects in areas of geological prospecting and population analysis could improve the efficiency of ASM assistance.     

Canadian Environmental Effects Monitoring: Experiences with Pulp and Paper and Metal Mining Regulatory Programs

In Canada, Environmental Effects Monitoring (EEM) programs exist within two regulations: the Pulp and Paper Effluent Regulations and the newMetal Mining Effluent Regulations under the Canadian Fisheries Act. EEM provides a biological, effects-based feedback loop to assess the effectiveness of technology-based regulations in protecting receiving environments. The promulgation of the Pulp and Paper Effluent Regulations, in 1992, represented a significant step forward in the Canadian regulatory approach by incorporating directly into a regulation a requirement to assess the effects of effluent discharges on receiving environments using proven scientific monitoring methodologies. Similarly, an assessment of the aquatic impacts of mines resulted in recommendations to amend the Metal Mining Effluent Regulations, recently promulgated in 2002, and includes an EEM program as a science-based feedback loop. As such, these regulations recognize the possibility that national, technology-based standards may not necessarily protect all receiving environments because of the diversity and variability of both discharges and receiving sites across the country. Since that time, EEM has improved its flexibility by considering both advances in science and the uniqueness of monitoring sites across Canada to allow the most appropriate and cost-effective monitoring approaches at each site while maintaining national consistency. This paper discusses the use of monitoring under two Canadian regulations to assess effects on aquatic ecosystems. As well, the National EEM approach to maintaining up-to-date scientific practices in a national regulatory program is discussed using examples.     

加强矿产资源开发中对环境的保护与治理

矿产资源开发对促进国民经济的发展具有重要的作用,但与此同时也带来不少环境问题,如破坏土地和生态环境,在矿石采选冶中产生“三废”对周围环境严重污染,破坏水资源平衡,引发地质灾害等。因此,现在必须高度重视并加强矿产资源开发中对环境的保护与治理,使矿产资源开发与矿山环境保护协调发展。首先,应制订并实施各地区的矿产开发规划,根据环境容量等调整矿业布局和矿业结构,严格对矿山环境进行监测、监管;其次,应加强对矿山环境的调查和评价,加强矿山环境保护的科技研究,提高矿山环境防治技术水平并加速技术推广;最后,应加强矿山环境保护的宣传教育,使矿山环境在全体公民的参与和监督下得到有效的保护。     

Heavy Metal Content in Xylem Sap (Vitis Vinifera) from Mining and Smelting Areas

No data are available on the content of heavy metals in the xylem sap of grapevines growing in contaminated areas. The aim of this work was to obtain data on the concentration of Pb, Zn, Cd and Cu in the xylem sap of grapevine (Vitis vinifera) cultivar Monica (ungrafted), growing near contaminated sites: a smelter, an abandoned and an active mine, and to investigate relationships between xylem sap mineral composition and the heavy metal content of the soil. The concentrations of Pb, Zn, Cd and Cu in the sap were enhanced compared to that of the soil, ranging from 4.3 to 611.4 µg Pb , 801 to 6176 µg Zn , 2.5 to 45 µg Cd and 19.8 to 161 µg Cu . Dry matter of xylem sap was significantly related to the heavy metals content in xylem saps, but no significant relationship between the metals in sap and total and DTPA/TEA extractable metal fraction in soil was found.     

一种新型的煤气回火安全装置

介绍了一种新型的煤气回火安全装置,说明了它的工作原理,主要参数,工艺结构等,叙述了其研制过程和应用情况。     

可压密煤层瓦斯运移方程与数值模拟研究

建立了非均质可压密煤层瓦斯运移方程和数值模拟方程,通过计算机数值模拟解,并运用相似理论,得到了煤层瓦斯压力分布曲线和煤（孔）壁瓦斯涌出衰减曲线方程。采掘面围岩中的集中应力峰值点存在高瓦斯压力和压力梯度,克林伯格效应和煤体排放瓦斯后的应力释放对钻孔瓦斯流量有明显的增长作用     

DDS系列煤炭自燃阻化剂实验研究

为寻找高效阻化剂以防止煤炭自热引燃，在控温炉中对ＤＤＳ系列煤自燃阻化剂的阻化效果进行了实验研究，并与经前的阻化剂做了比较。实验采用烟煤作为试样，借助于著名的Ｆｒａｎｋ－Ｋａｍｅｎｅｔｓｋｉｉ模型，利用４，６，８和１０厘米立方体阻化煤磁地６０－２２０℃温度范围估测其氧化反应的活化能。     

煤与瓦斯突出延期发生的原因探讨──“球壳失稳”假说的解释性研究之一

依据球壳失稳假说的原理对煤与瓦斯突出延期发生的原因进行了探讨，并且针对延期突出的危害和特点提出了相应的对策。