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1.
Abstract. High-resolution airborne thermal infrared (TIR) imagery
data were collected over 90.6 km2 (35
mi2) of remote and rugged terrain in
the Kettle Creek and Cooks Run Basins, tributaries of the West
Branch of the Susquehanna River in north-central Pennsylvania.
The purpose of this investigation was to evaluate the
effectiveness of TIR for identifying sources of acid mine
drainage (AMD) associated with abandoned coal mines. Coal mining
from the late 1800s resulted in many AMD sources from abandoned
mines in the area. However, very little detailed mine
information was available, particularly on the source locations
of AMD sites. Potential AMD sources were extracted from airborne
TIR data employing custom image processing algorithms and GIS
data analysis. Based on field reconnaissance of 103 TIR
anomalies, 53 sites (51%) were classified as AMD. The AMD
sources had low pH (<4) and elevated concentrations of iron
and aluminum. Of the 53 sites, approximately 26 sites could be
correlated with sites previously documented as AMD. The other 27
mine discharges identified in the TIR data were previously
undocumented. This paper presents a summary of the procedures
used to process the TIR data and extract potential mine drainage
sites, methods used for field reconnaissance and verification of
TIR data, and a brief summary of water-quality data. 相似文献
2.
Abstract. Ground water in alluvial sediments of upper Silver Bow Creek is chronically contaminated with heavy metals, including Cd,
Cu, Fe, Mn, and Zn. Most of this contamination stems from slag, mill tailings, and waste rock from the Butte mining district
that had been deposited along the ancestral Silver Bow Creek floodplain. Much of this mine waste is now buried by fill, topsoil,
buildings, or parking lots. Although the pH values of most wells in the region are in the 5.5 to 7.0 range, a cluster of monitoring
wells near the site of a former mill and smelter contain water that is strongly acidic (pH < 4.5), with extremely high dissolved
metal concentrations (Cu up to 750 mg/L; Zn up to 490 mg/L). Ground water discharging from the area is currently collected
by a subsurface French drain and conveyed to a treatment facility where lime is added to precipitate metals from solution. 相似文献
3.
Abstract In many regions of the world, flooded mines are a potentially cost-effective option for heating and cooling using geothermal
heat pump systems. For example, a single coal seam in Pennsylvania, West Virginia, and Ohio contains 5.1 x 1012 L of water. The growing volume of water discharging from this one coal seam totals 380,000 L/min, which could theoretically
heat and cool 20,000 homes. Using the water stored in the mines would conservatively extend this option to an order of magnitude
more sites. Based on current energy prices, geothermal heat pump systems using mine water could reduce annual costs for heating
by 67% and cooling by 50% over conventional methods (natural gas or heating oil and standard air conditioning). 相似文献
4.
Abstract.
This paper describes pilot scale tests of a novel process for the neutralisation of acidic mine water. Leachate from a waste coal dump was neutralised with limestone, and iron, aluminium, and sulphate were removed. Specific aspects studied were: the process configuration; the rates of iron oxidation, limestone neutralisation, and gypsum crystallisation; the chemical composition of the effluents before and after treatment; the efficiency of limestone utilisation; and the sludge solids content. The acidity was decreased from 12,000 to 300 mg/L (as CaCO3), sulphate from 15,000 to 2,600 mg/L, iron from 5,000 to 10 mg/L, aluminium from 100 to 5 mg/L, while the pH increased from 2.2 to 7.0. Reaction times of 2.0 and 4.5 h were required under continuous and batch operations respectively for the removal of 4 g/L Fe (II). The iron oxidation rate was found to be a function of the Fe (II), hydroxide, oxygen, and suspended solids (SS) concentrations. The optimum SS concentration for iron oxidation in a fluidised-bed reactor was 190 g/L. Up-flow velocity had no influence on the rate of iron oxidation in the range 5 to 45 m/h. Sludge with a high solids content of 55% (m/v) was produced. This is high compared to the typical 20% achieved with the high density sludge process using lime. It was determined that neutralisation costs could be reduced significantly with an integrated iron oxidation and limestone neutralisation process because limestone is less expensive than lime, and a high-solids-content sludge is produced. Full scale implementation followed this study. 相似文献
5.
Abstract. Helicopter-mounted electromagnetic (HEM) surveys have been
used to delimit conductive mine pools and groundwater features
at various areas in the eastern United States that contain
abandoned surface and underground coal mines. HEM was used to
delineate the source areas and flow paths for acidic,
metal-containing groundwater. This will aid remediation efforts.
A recent HEM survey of Kettle Creek Watershed, Clinton County,
Pennsylvania, using a 6-frequency electromagnetic data
acquisition system, is presented. The survey accurately located
conductive pools within underground mines, acidgenerating mine
spoil at surface mines, and areas of groundwater recharge and
discharge. 相似文献
6.
Abstract:
The water network of a coal mine was audited and simulated by an interactive steady state model and the results were used to optimise the mines water management strategy. Simulation of the interactions showed that calcium carbonate powder could be used as an alternative to lime for neutralization of acid water at a reagent cost saving of 56%. Gypsum crystallization would reduce sulphate concentrations in the neutralization plant by 30% and in the coal processing plant by 60%. The capital cost for a neutralization/gypsum crystallization plant for separate treatment of coal discard leachate and less polluted streams would cost 3.0 million Rand (R), compared to R10.3 million for combined treatment. Only slightly less (8.9 t/d vs. 9.5 t/d) sulphate removal would be achieved during separate treatment. The over-saturation index (OSI) value can be controlled effectively by removing sulphate from the feed water for coal processing. Sulphate has to be lowered to 350 mg/L in a flow of 222 m3/h to obtain an OSI value less than 1. The capital cost of a 222 m3/h biological sulphate removal plant was estimated at R21.8 million (R4.1 million/(ML/d)); the running cost was estimated at R13.7 million/a (R4.10/m3). Pre-washing of the coal would reduce capital and running costs. 相似文献
7.
《国际露天开采、回填与环境杂志》2013,27(1):74-89
The waste dump of sulphide-containing rocks is one of the potential acid mine drainage sources, since it contains a huge amount of readily oxidised sulphide mineral, due to its exposure to air and water. The application of the dry cover system is regarded as one of the best practices since it prevents acid mine drainage of the waste rock dump at the surface coal mine. However, the implementation of the dry cover system in field practice has faced several obstacles due to the limited number of cover materials. The nature of geological condition is considered to be a controlled issue, whilst the problem is the mining method and equipment size. This article describes the acid generation mechanism and its control, application of cover system and the problems that are faced in Indonesian coal mines, whilst discussing the preliminary laboratory results of multi-layer cover systems. It finally proposes a new covering strategy in an attempt to overcome the problem. 相似文献
8.
Oliver Totsche Andrew Fyson Christian E. W. Steinberg 《Mine Water and the Environment》2006,25(4):204-213
Abstract. Microbial alkalinity production was evaluated as a method to prevent reacidification of neutralized mining lakes by acidic
ground and seepage water. We used 60 L mesocosms to represent the sediment and water column of a shallow acidic mine lake.
To enhance alkalinity production, acidic and neutralized lake waters were treated with either phosphorus (controlled eutrophication)
or organic matter (controlled saprobization). Controlled eutrophication could not produce enough autochthonous biomass as
substrate for microbial alkalinity production to change the acidity of the water. Chemical pre-neutralization of the acidic
water caused the inorganic carbon concentration to increase, but at the same time, hindered algae growth by reducing the availability
of phosphate by sorption to the freshly precipitated iron hydroxide. This effect was so strong that even high phosphorus additions
could not increase the algae biomass production. In contrast to controlled eutrophication, controlled saprobization produced
significant alkalinity. Despite inhibition of the most important alkalinity producing process, namely microbial sulfate reduction,
by low pH values, the microbial alkalinity production rate was not affected by pre-neutralization of the water column. Other
alkalinity producing processes raised the pH in the reactive zone until sulfate reduction was no longer inhibited. 相似文献
9.
Abstract A demonstration project was conducted to investigate treating acid mine water by alkaline injection technology (AIT). A total
of 379 t of alkaline coal combustion byproduct was injected into in an eastern Oklahoma drift coal mine. AIT increased the
pH and alkalinity, and reduced acidity and metal loading. Although large improvements in water quality were only observed
for 15 months before the effluent water chemistry appeared to approach pre-injection conditions, a review of the data four
years after injection identified statistically significant changes in the mine discharge compared to pre-injection conditions.
Decreases in acidity (23%), iron (18%), and aluminum (47%) were observed, while an increase in pH (0.35 units) was noted.
Presumably, the mine environment reached quasi-equilibrium with the alkalinity introduced to the system. 相似文献
10.
Abstract Passive treatment of acid mine drainage (AMD) requires a combined strategy to minimize the effect of climatic variability
on the treatment performance of the system. A vertical-flow combined passive treatment system was developed and evaluated
in a bench-scale laboratory test for a 290-day period. The combined system consisted of four components with specific treatment
functions: an oxidation/precipitation basin for excess iron removal; a peat biofilter for heavy metal sorption and the establishment
of anoxic conditions; a bioreactor for alkalinity generation and sulphate reduction; and an anoxic limestone drain for alkalinity
addition. The benchscale system was dosed with moderate strength synthetic AMD at a surface loading of 95 L/m2/d, and operated under continuous flow conditions. Removal efficiencies were 99.7%, 99.9%, 99.9%, 98.6%, 98.2%, and 99.9%
for Fe, Al, Zn, Mn, Ni, and Cu, respectively, while Cd remained more mobile with a removal efficiency of 66.5%. Sulphate concentrations
were reduced from 3030 mg/L to 814.9 mg/L and the acidic drainage was neutralized to an effluent pH of 7.2 and an alkalinity
of 1353.6 mg/L (as CaCO3). 相似文献
11.
Abstract. The Sleeper open pit gold mine operated from the mid-1980s
through the mid-1990s. Operations were mostly sub-water table
and extensive dewatering was required to lower groundwater
levels by 180 m. Dewatering flows peaked at 930 L/s, with most
flow contributed from an alluvial aquifer. After completion of
mining, the pit was rapidly filled with water pumped from the
alluvial aquifer to reduce the exposure time of sulfide wall
rocks and waste rocks in the ultimate pit. The pumped alluvial
groundwater provided a large volume of low total dissolved
solids (TDS), high alkalinity water that controlled the early
chemistry. The rising lake waters were amended with lime to
buffer excess acidity contributed to the lake from reactive pit
wall rocks during submergence. The pore water contained in
submerged waste rock at the base of the pit was elevated in TDS
and subsequently of higher density that the lake water. The
density contrast and waste rock location limited contributions
of waste rock pore water to the main body of the lake. Some
stratification of the early lake occurred, with shallow water
characterized by higher pH, low dissolved metals, and sulfate;
deeper water had lower pH and higher dissolved metals and
sulfate. The reservoir of alkalinity in the shallow layer mixed
with the deeper waters and created a stabilized lake with a
homogenized column that exceeded water quality expectations.
Current water quality meets all Nevada primary drinking water
standards with the exception of sulfate, TDS, and manganese,
which are slightly elevated, as predicted. Chemistry has
remained stable since development of the initial lake. 相似文献
12.
Robert S. Hedin Sherry L. Stafford Theodore J. Weaver 《Mine Water and the Environment》2005,24(2):104-106
Abstract In northwestern Pennsylvania (USA), numerous abandoned natural gas wells are producing artesian flows of Fe-contaminated water. The origin of the polluted water has been generally assumed to be brines from the gas-producing sands. We sampled 20 artesian discharges where iron staining was conspicuous. The waters were not brines, but were more characteristic of acid mine drainage (AMD). The dominant cations were Fe, Ca, and Mg, while the dominant anion was sulfate. The study area has a long history of coal mining in the lower Allegheny formation; however, the coal beds are generally at higher elevations than the discharges. We propose that AMD formed in the coal mines is infiltrating into lower aquifers, moving outside the lateral limits of mining, and using abandoned gas wells as conduits to the surface. While flowing through the underlying sandstones, the AMD chemistry is modified by contact with siderite, the dominant carbonate mineral in this stratigraphy. This would suggest that current remediation strategies that emphasize plugging the pollution-producing gas wells may be ill-advised because the source of the polluted water is more shallow than currently assumed. 相似文献
13.
武山铜矿选矿尾矿浆中和处理采矿井下酸性废水的研究 总被引:1,自引:0,他引:1
利用选矿尾矿浆中的残留石灰中和处理采矿井下酸性废水,该法应用到武山铜矿,可充分利用现有的尾矿输送和尾矿库设施,无需新建污水处理站和堆渣库,处理后的外排水稳定达标。此工艺具有处理工艺简单,运行费用低,管理方便等特点,废水处理成本仅为0.17元/t,比单独治理废水节约1.12元/t. 相似文献
14.
Christopher H. Gammons John J. Metesh Dean M. Snyder 《Mine Water and the Environment》2006,25(2):100-107
Abstract. This paper outlines general trends in the geochemistry of the more than 10,000 km of flooded underground mine workings in
the Butte mining district. The waters in question range in pH from 4 to 8, are all moderately to strongly reducing, and show
a huge range in concentration of dissolved metals such as Al, As, Fe, Mn, and Zn. Metal concentrations and total acidity are
highest in the Kelley mine shaft, which was the main dewatering station used to pump ground water from the underground mine
complex during active mining operations. In contrast, metal concentrations are much lower in the outer portions of the district
where many of the mines contain hydrogen sulfide formed by sulfate-reducing bacteria. In comparison to the other heavy metals,
concentrations of Pb and Cu are quite low in the flooded mine shafts. An interesting inverse correlation between pH and water
temperature is noted, which may be partly caused by exothermic pyrite oxidation reactions in the central portion of the district. 相似文献
15.
Robert S. Hedin 《Mine Water and the Environment》2006,25(3):146-152
Abstract: The net acidity of a water sample can be measured directly by titration with a standardized base solution or calculated from
the measured concentrations of the acidic and basic components. For coal mine drainage, the acidic components are primarily
accounted for by free protons and dissolved Fe2+, Fe3+, Al3+, and Mn2+. The base component is primarily accounted for by bicarbonate. A standard way to calculate the acidity for coal mine drainage
is: Acidcalc = 50*(2*Fe2+/56 + 3*Fe3+/56 + 3*Al/27 + 2*Mn/55 + 1000*10-pH)—alkalinity, where acidity and alkalinity are measured as mg/L CaCO3 and the metals are mg/L. Because such methods of estimating acidity are derived by independent laboratory procedures, their
comparison can provide a valuable QA/QC for AMD datasets. The relationship between measured and calculated acidities was evaluated
for 14 datasets of samples collected from mine drainage discharges, polluted receiving streams, or passive treatment systems,
containing a total of 1,484 sample analyses. The datasets were variable in nature, ranging from watersheds where most of the
discharges contained alkalinity to ones where all of the discharges were acidic. Good relationships were found to exist between
measured and calculated acidities. The average acidity measurement was 239 mg/L CaCO3 and the average acidity calculation was 226 mg/L CaCO3. Linear regressions were calculated for individual datasets and for the entire dataset. The linear regression for the entire
dataset was: Acidcalc = 0.98 * Acidmeas – 8, r2 = 0.98. The good correlation between calculated and measured acidity is the basis for an easy and inexpensive QA/QC for AMD
data. Substantial variation between measured and calculated acidities can be used to infer sampling or analytical problems. 相似文献
16.
D. H. M. Alderton T. Serafimovski B. Mullen K. Fairall S. James 《Mine Water and the Environment》2005,24(3):139-149
Abstract Pollution from current and past mining is a significant problem in several parts of the former Yugoslav Republic of Macedonia.
Water from six different mining areas in Macedonia was analysed to assess the effects of metalliferous mining activities.
Drainage sediments at all locations show evidence of physical and chemical contamination; water compositions, however, were
more variable. Low pH water associated with mining has led to the dissolution of minerals and the mobilization of metals from
the ores and the host rocks. Only Sb was noted to exhibit enhanced mobility in higher pH waters. The Zletevo Pb-Zn mine discharges
low pH water that has high levels of several metals, including Al, Zn, Cd, and Fe; sediment concentrations are grossly elevated
for several km downstream. Toranica and Sasa Pb-Zn mines exhibit similar sediment contamination of Pb, Zn, Cd, and other ore-related
metals. However, concentrations of metals in waters are far lower at both of these mines, due to less pyrite in the ore and
the buffering of the acid waters by carbonate host lithologies. At the Buchim copper mine, waters are both acidic and high
in dissolved solids; Cu concentrations exceed 100 mg/L. Krstov Dol and Alshar are small, disused As-Sb mines that discharge
waters that exceed potable values for some contaminants (e. g. As), but this may be related to the mineralization of the bedrock
rather than the mines. In general, metal concentrations decreased downstream from the source due to dilution from other rivers
and coprecipitation of metals on other mineral phases (e. g. Fe-, Al- and Mn-oxides, and hydroxides). 相似文献
17.
Removal of Sulfate,Zinc, and Lead from Alkaline Mine Wastewater Using Pilot-scale Surface-Flow Wetlands at Tara Mines,Ireland 总被引:1,自引:0,他引:1
Abstract.
Passive treatment systems have primarily been used at abandoned mines to increase pH and remove metals from the drainage water. Two pilot-scale treatment wetlands were constructed and monitored at an active lead/zinc mine (Tara Mines) in Ireland to treat alkaline mine water with elevated sulfate and metal levels. Each system comprised three in-series surface-flow cells that contained spent mushroom compost substrate. Typically, aqueous concentrations of 900 mg L-1 sulfate, 0.15 mg L-1 lead, and 2.0 mg L-1 zinc flowed into the treatment wetlands at c. 1.5 L min-1. During a two-year monitoring period, removal of sulfate (mean of 10.4 g m-2 day -1 (31%), range of 0-42 g m-2 day -1 (0-81%)), lead (mean of 1.9 mg m-2 day -1 (32%), range of 0-6.6 mg m-2 day -1 (0-64%)) and zinc (mean of 18.2 mg m-2 day -1 (74%), range of 0-70 mg m-2 day -1 (0-99%)) were achieved. These contaminants were somewhat associated with the vegetation roots but more significantly with the substrate. Communities of colonizing macroinvertebrates, macrophytes, algae, and microorganisms contributed to the development of a diverse ecosystem, which proved to be a successful alternative treatment process. The interacting processes within the wetland ecosystems responsible for wastewater decontamination are being further elucidated and quantified using a systems dynamic model. 相似文献
18.
Christopher H. Gammons 《Mine Water and the Environment》2006,25(2):114-123
Abstract. The Lexington tunnel is the last accessible underground mine working in the Butte, Montana mining district. Used as recently
as 1993, the tunnel and adjacent workings have been abandoned for over 10 years. Although the Lexington tunnel is over 200
m above the regional water table, perched water is present over much of its extent. Mine water near the portal is moderately
acidic (pH 4 to 5), with extremely high concentrations of metals, including Cu (up to 1000 mg/L) and Zn (up to 1400 mg/L).
In the middle reaches of the tunnel, the quality of the water is much better, with near-neutral pH, high bicarbonate alkalinity,
and lower concentrations of heavy metals. The low acidity and metal content is attributed to a lack of pyrite and other sulfides
in this portion of the mine, as well as the presence of carbonate minerals, such as rhodochrosite (MnCO3), in exposed veins. Sulfide minerals are more widespread further back in the tunnel, and are now oxidizing rapidly, leading
to pockets of severe acid drainage (pH< 3, dissolved Zn up to 5000 mg/L).
Geochemical modeling suggests that the near-neutral waters—the most voluminous type encountered in the Lexington tunnel—are
close to equilibrium saturation with rhodochrosite and hydrous Zn-carbonate (ZnCO3•H2O). The Eh of these waters is most likely controlled by redox reactions involving dissolved Mn2+ and secondary, Zn-rich, hydrous Mn-oxides. In contrast, the Eh of the acidic waters appears to be controlled by reactions
involving Fe2+ and Fe3+. Most of the acidic waters are saturated with K-jarosite, which forms delicate, straw-like dripstones at several localities.
Decaying mine timbers could be an important renewable source of organic carbon for heterotrophic microorganisms, such as iron-
and sulfate-reducing bacteria, especially deeper in the mine workings where the ground is saturated with anoxic ground water. 相似文献
19.
Abstract. Leachate water quality from covered and uncovered unoxidised sulphide-rich tailings in six pilot-scale (5x5x3 m3) test cells was monitored during 2004 and 2005. The covers consisted of a layer of clayey till, sewage sludge, apatite or
Trisoplast (a commercial mixture of tailings, bentonite, and a polymer). All layers were protected by an unspecified till
except in one reference cell, where the tailings were left open. All leachate waters showed near-neutral pH as a result of
neutralization by calcite in the tailings and by Ca(OH)2 added prior to deposition. Average dissolved sulphur concentrations in the leachates were ≈ 600 mg L-1, except in the cell with sewage sludge (300 mg L-1). The source of sulphur was mainly pyrite oxidation, but residual sulphur probably remained from the enrichment process.
The near-neutral pH favoured precipitation of metal-(oxy)hydroxides with subsequent removal of trace elements such as Cd,
Cu and Pb (< 15 μg L-1) from the solutions. High concentrations of Co, Mn, Ni, and Zn were found in leachates from the apatite, Trisoplast, and
uncovered tailings cells. High As concentrations were found in the leachates in the sewage sludge and clayey till cells. The
lowest metal concentrations, redox potential, and highest pH were found in the sewage sludge cell. Decreased elemental metal
concentrations during 2004 suggest improved performance over time. 相似文献
20.
Abstract: Modeling of mine water rebound in the southernmost zone of the Durham Coalfield has been undertaken in an attempt to reproduce
observed water level recovery, since the 1970s, within five coal blocks south of the Butterknowle Fault. The lumped parameter
model GRAM (groundwater rebound in abandoned mineworkings) was chosen to perform the simulations since it overcomes, to a large extent, a common problem found in such studies,
namely a lack (especially concerning historic hydrogeological records) and superabundance of various kinds of data. The results
obtained from this approach are satisfying and closely resemble the observed pattern of mine water rebound for the mining
blocks studied. Such research indicates the critical dependence of predictions on factors such as the volume of water flowing
into the system, the percentage runoff, and the value of storage coefficient assigned to the old workings. Model predictions
are most useful as a tool for improving the conceptual understanding of abandoned mine systems and as a basis for evaluating
alternative possibilities of coalfield behaviour, rather than as a strict quantitative assessment for all management purposes. 相似文献