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71.
The Stockton Coal Mine, located on the West Coast of New Zealand, is evaluating the use of a mussel shell bioreactor (MSB) to treat acidic metalliferous runoff from acid forming overburden. This novel approach is similar in concept to vertical flow wetlands (VFWs) and successive alkalinity producing systems (SAPS). The MSB system is a trapezoidal pit 2 m deep, 35 m long, 3–10 m wide with 60° angle sides. During operation it contained 160 tonnes (240 m3) of mussel shell material and was saturated with a 100–200 mm water cap. Influent flowed through the reactor at a mean rate of 0.3 L s−1 resulting in a hydraulic retention time (HRT) of ≈6 days. The prototype MSB was in operation for a total of 1027 days, from June 2009 through March 2012, and effectively sequestered 99.7% of Al, 99.3% of Fe, 98.8% of Ni, 98.4% Tl and 99.3% of Zn, as determined from a previous evaluation of MSB performance. The MSB also effectively neutralized acidity, which resulted in an increase in influent pH from 2.8 to 6.9 in the effluent. Based on an examination of several excavated pits, five distinct reaction zones developed within the MSB. The reaction zones consisted of an allochthonous sediment layer (0–330 mm), an oxidized iron-rich ocherous layer (at 330–350 mm depth), an aluminum layer (at 350–600 mm depth) with geochemical variations throughout (350–500 mm and 500–600 mm); and a chemically reduced bottom shell layer (at 600–1100 mm). Representative samples were collected from each layer and analyzed using a combination of geochemical and physical methods to assess the stability of the secondary minerals and trace metal deportment within the MSB. Major elements Fe, Al, Ni, Tl, and Zn where preferentially associated with particular layers within the MSB. Elevated concentrations of Fe (110,000 mg kg−1) were observed in the allochthonous sediment and ocherous precipitate layers, while Al (27,816 mg kg−1), Ni (55 mg kg−1), and Zn (655 mg kg−1) were elevated within the aluminum and lower reduced depths within the MSB. Trace Tl (21 mg kg−1) showed varying concentrations throughout the MSB, but was strongly correlated to lower layers of the system. Microbial biofilms were observed within the reduced portions of the shell layers often proximal to bacterial shaped sulfides. The geochemical assessment of the MSB presented in this study is the first of its kind for a MSB, and supports the argument that this system is another viable option for passive treatment of AMD. 相似文献
72.
73.
白云鄂博矿区土壤和植物中稀土元素的分布特征 总被引:2,自引:1,他引:1
白云鄂博矿区是稀土的主要产出地,在矿山开采和选炼等过程中,稀土元素通过迁移、富集等作用进入植物体,研究稀土元素的分布特征和迁移规律,可为白云鄂博矿体闭坑后的生物修复提供数据支持。本文设置了7个土壤采样点,采集铁花、沙蒿、沙打旺、沙朋、青蒿、小叶杨、猪毛菜七种植物,用电感耦合等离子体质谱法测定土壤和植物的根、茎、叶及整株的稀土含量,研究稀土元素在土壤和植物中的分布特征和迁移规律。统计分析结果表明:随着采样区与主矿区的距离增加,土壤样品中的稀土含量逐渐减少;在七种植物中,铁花的稀土含量最高,青蒿最低;对不同植物的整株稀土含量和各部位(根、茎、叶)稀土含量进行多元线性回归分析,叶(或花)的稀土含量在整珠植物中的占比最大。此外在不同季节,植物中的稀土含量基本保持不变,含量较高的稀土元素为Ce(0.0035%~0.020%)、La(0.0012%~0.011%)、Nd(0.0010%~0.0094%)和Pr(0.00036%~0.0046%),其中Ce最高。本研究提出:根据土壤样品中的稀土含量逐渐减少的特征,矿区周围土壤的稀土来源可能是矿石在采、选过程中的扩散造成的;根据植物富集稀土的能力,在矿山闭坑后,可种植富集稀土能力强的植物——铁花,进行矿山生物修复。 相似文献
74.
75.
基于信湖煤矿水文地质条件,利用数值法和地下水动力学方法分别进行矿坑涌水量预测,并就预测结果进行对比分析,结果显示:利用数值模拟法预测得到的信湖矿的矿坑涌水量为11 000~3 236 m^3/d,水动力学方法得到的信湖矿的涌水量为13 152 m^3/d,两种预测方法所测算出的结果偏差不大,总体认为数值法的计算结果比较可靠。同时可将水动力学法当做数值法计算矿坑涌水量预测的一种检验印证方法,两种计算方法结合起来会使矿坑涌水量的预测结果更加准确。 相似文献
76.
Mine waste dumps and heavy metal pollution in abandoned mining district of Boccheggiano (Southern Tuscany, Italy) 总被引:12,自引:1,他引:11
M. Benvenuti I. Mascaro F. Corsini P. Lattanzi P. Parrini G. Tanelli 《Environmental Geology》1997,30(3-4):238-243
Mining activity in the Boccheggiano-Fontalcinaldo area (Southern Tuscany) dates back at least to the 16th century AD and
lasted up to very recent times. Copper-rich hydrothermal veins, massive pyrite deposits, and their gossans were exploited.
Two mine waste dumps (Fontalcinaldo, Fontebona), one flotation tailings impoundment (Gabellino), and one roasting/smelting
waste dump (Merse-Ribudelli) in the study area were selected to ascertain the environmental effects of such protracted mining
activity. Primary waste mineralogy is mainly characterized by pyrite, gypsum, quartz, carbonates, chlorites, and micas. Secondary
oxidation mineralogy includes Fe and Cu sulfates and hydroxy sulfates, Cu carbonates, Fe and Al oxyhydroxides, and other phases
[neogenic cassiterite at Fontalcinaldo; probable calkinsite, (Ce,La)2(CO3)3· 4H2O, at Fontebona]. Mine waste samples show extremely variable contents of toxic elements (Cu, Pb, Zn, Bi, Cd, As), with average
values in the order of hundreds to thousands of parts per million (except for Bi and Cd). In some samples, the abundance of
proper minerals of these metals cannot account for the entire metal load. Conceivably, either solid solution substitutions
or adsorption processes contribute to the intake of released metals into newly formed minerals. Release and transport of pollutants
was affected to variable degrees by acid-neutralization processes. The highest metal and acid concentrations occur close to
the investigated wastes and rapidly decrease moving downstream some hundreds of meters or less, with the partial exception
for Mn and Fe. Other than dilution effects, this phenomenon may be ascribed to metal adsorption and precipitation of solid
phases.
Received: 16 April 1995 · Accepted: 14 December 1995 相似文献
77.
Amber J. Roesler Christopher H. Gammons Gregory K. Druschel Harry Oduro Simon R. Poulson 《Aquatic Geochemistry》2007,13(3):211-235
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
78.
用QSAR法研究有机磷农药对海洋扁藻的构效关系 总被引:8,自引:2,他引:6
1997年3月,利用QSAR构效关系分析方法和计算模拟手段,对中国洞海地区常用的11种有机磷农药对海洋五心形扁藻拦数抑制浓度进行研究。建立有机磷农药对海洋扁藻致毒效应的QSAR模型;lg(1/EC50)=0.193lgP-0.08(lgP)^2+1.10σ3+0.292^1X-0.164(n=11,S=20,R=0.9696);lg(1/EC50_=0.191lgP-0.09(lgP)^2+1.0 相似文献
79.
强度折减法在滑坡稳定性分析中的应用 总被引:3,自引:3,他引:0
沁水县侯村煤矿边坡处治后,I~III段使用良好,IV段抗滑挡墙失效。本文采用有限元强度折减法计算,强度指标比原定的降低了1.29倍。同时,在折减过程中,通过计算分析剪应力集中部位,确定滑面是在老滑面的基础上发展的部分新滑面,形成新的剪出口。利用折减后强度参数,计算对比新滑面与次级滑面的滑坡推力,认为挡墙破坏为新滑面推力过大所致,与原设的“次级滑面为最危险滑面”情况不符,计算结果与实际情况较吻合。 相似文献
80.
桃园煤矿10煤底板裂隙发育不均匀,合理确定钻孔注浆堵水有效半径,是10煤安全开采的保障。经理论计算和实验研究,确定注浆有效半径为1015 m。 相似文献