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1.
Laboratory and field treatment tests were performed to evaluate the effectiveness of lime treatment for mitigation of environmental
effects of acid mine drainage (AMD) at the Sarcheshmeh porphyry copper mine. AMD associated with the rock waste dumps is contaminated
with Al (>36,215 μg/L), Cd (>105 μg/L), Co (>522 μg/L), Cu (>53,250 μg/L), Mn (>42,365 μg/L), Ni (>629 μg/L), and Zn (>12,470 μg/L).
The concentrations of other metals (Fe, Mo, Pb, and Se) are low or below detection limits (As, Cr, and Sb). Due to the very
high Al and Mn content and the low concentration of Fe, a two-stage lime treatment method was chosen for the laboratory tests.
In the first stage, the AMD was treated at four pH set points: 7.5, 8.9, 9, and 10. In the second stage, after removing the
sludge at pH 9, treatment was continued at pH 10 and 11. The results indicated that a two-stage treatment method was not necessary
because elements such as Al, Cu, Co, and Zn were easily treated at pH 7.5, while complete removal of Cd, Mn, and Ni only required
a pH of 10. Increasing pH during the treatment process only caused a slight increase in Al. Field treatment tests support
the laboratory results. Lime treatment of highly contaminated AMD from dump 11, using simple low density sludge pilot scale
equipment, show that contaminant metals are treatable using this method. The mean treatment efficiency for contaminant metals
was 99.4% for Al, % for Cd, 99.6% for Co, 99.7% for Cu, 98.5% for Mn, 99.7% for Ni, 99% for U, and 99.5% for Zn. The optimum
pH for AMD treatment by lime was in the range of 9–10. The produced sludge in the treatment process was highly enriched in
the contaminant metals, especially Cu (>7.34%), Al (>4.76%), Mn (>2.94%), and Zn (>1.25%). A correlation coefficient matrix
indicates that the distribution pattern of the contaminant metals between soluble and precipitated phases is consistent with
the hydrochemical behavior of the metals during the lime treatment process. 相似文献
2.
Selenium leached from coal tailings and spoil is a challenge for mining operations in southern West Virginia. Selenium discharges
are not supposed to exceed 5 μg/L, and yet are commonly in the range of 10–25 μg/L. Once in the selenate form, selenium removal
can be extremely difficult and expensive, particularly in the narrow valleys and highly variable flow regimes of southern
West Virginia. This study reports on the first 96 weeks of a leaching study. Selenium leached at the rate of 0.06% of the
extant selenium pool per day. After 96 weeks, about 35% of the original, potentially mobile selenium had leached. While sulfur
was far more abundant, its leach rate was about 10% of the selenium rate. Iron oxyhydroxide was found to reduce the concentration
of dissolved selenium by about 70%, which indicates that selenite is the dominant, mobile selenium species during initial
weathering, and that selenium could be controlled at its source, through special handling and treatment of selenium-rich rock
units. Iron oxyhydroxide kept selenium near the regulatory limit of 5 μg/L throughout the experiment. 相似文献
3.
Rosa Cidu 《Mine Water and the Environment》2007,26(4):199-208
Cu–Pb deposits at Funtana Raminosa in Central Sardinia were intensively exploited, mostly underground, from 1917 until 1983.
Flotation tailings were dumped near the mine plant. A hydrogeochemical survey carried out in 2004 showed that mine drainage
collected from several galleries was circumneutral, due to the availability of carbonate minerals that buffer the acidity
produced by the oxidation of Fe-bearing sulphides. The mine waters contained higher concentrations of dissolved SO4, F, Zn, Cd, Pb, Mn, and Mo than was observed in uncontaminated spring and stream waters in the area. Drainage from the oldest
flotation tailings showed much lower concentrations of Zn, Cd, and Pb than those generally observed in mine waters. In contrast,
drainage from the recent flotation tailings had the highest levels of dissolved SO4, Zn, and Cd (1,600, 30, and 0.8 mg/L, respectively) when sampled in the dry season; these were two orders of magnitude lower
in the rainy season under high flow condition. Pb was ≈ 5 μg/L under different flow conditions. Water in the Rio Saraxinus,
a stream that drains the entire mining area, had a relatively low level of contamination (170 μg/L Zn, 7 μg/L Cd, and 0.9 μg/L
Pb). 相似文献
4.
Soma Giri Gurdeep Singh S. K. Gupta V. N. Jha R. M. Tripathi 《Mine Water and the Environment》2010,29(3):225-234
The East Singhbhum region is a highly mineralised zone, with extensive mining of copper, uranium, and other minerals. The
concentrations of certain metals (Fe, Mn, Zn, Pb, Cu, and Ni) were measured in 10 groundwater locations and eight surface
water locations for four seasons during 1 year around a proposed uranium mining area. The ranges of Fe, Mn, Zn, Pb, Cu, and
Ni in surface water were 0.08–1.21, 0.02–0.32, 0.02–3.48 mg/L, 0.84–14, 1.25–36, and 1.24–15 μg/L, respectively, while in
groundwater, the ranges were 0.06–5.3, 0.01–1.3, 0.02–8.2 mg/L, 1.4–28, 0.78–20, and 1.05–20 μg/L, respectively. Only Fe and
Mn were found to exceed India’s drinking water standards. The data have been used to calculate a metal pollution index (MPI).
The MPI of both groundwater (28) and surface water (10) is well below the index limit of 100, which suggest that neither is
generally contaminated with respect to these metals. 相似文献
5.
Field Trials of Low-cost Reactive Media for the Passive Treatment of Circum-neutral Metal Mine Drainage in Mid-Wales,UK 总被引:1,自引:0,他引:1
R. Warrender N. J. G. Pearce W. T. Perkins K. M. Florence A. R. Brown D. J. Sapsford R. J. Bowell M. Dey 《Mine Water and the Environment》2011,30(2):82-89
This paper addresses the ability of five low-cost reactive materials to remove Zn, Pb, and Cd from Fe-poor, circum-neutral
pH metal mine water in Mid-Wales, UK. Compost, fly ash, waste shell material, iron ochre, and a mixture of blast furnace slag
(BFS) and basic oxygen furnace slag (BOS) were used in a series of small-scale passive treatment cells to assess metal removal
from mine drainage initially containing, on average, 23.5 mg/L Zn, 0.5 mg/L Pb, and 0.05 mg/L Cd. Trial treatment cells contained
between 1.5 and 12 kg of reactive media, had a 15 min residence time, and treated a discharge of up to 1 L per minute. Fly
ash from a peat-fired power station was found to be the most effective material for metal removal, with concentrations reduced
to 0.02 mg/L Zn, 0.0069 mg/L Pb, and 0.0001 mg/L Cd from over 1,000 L of water (between 98.6 and 99.9% removal). The other
materials initially achieved high levels of metal removal (between 75 and 99.9% Zn, Pb, and Cd removed); however, all of the
materials were saturated with Zn after less than 200 L of water had been treated. Metal sorption ranged from 21.4 mg/g Zn
for the peat fly ash to 0.0015 mg/g Cd for the compost and BOS/BFS slag. The results of the pilot-scale field trials can be
scaled to demonstrate that a modest-sized fly ash treatment cell (2.6 × 2.6 × 1 m) in size would be sufficient to remove 90%
of the total metal load (Pb, Zn, and Cd) from this 10 L/min mine water discharge for a 1 year period. Importantly this research
demonstrates that passive treatment for metal mine drainage can comply with water quality directives but cannot be considered
a ‘walk-away’ solution; it requires modest (potentially annual) maintenance. 相似文献
6.
Robert F. Mueller 《Mine Water and the Environment》2001,20(1):17-29
Results from bench-scale tests for thallium remediation in mining-impacted water are presented and removal mechanisms are
discussed. The source water consisted of surface runoff mixed with groundwater from an inactive gold mine in central Montana.
Bench scale columns were operated under continuous flow for 225 days to test for microbially-mediated thallium immobilization.
Various compositions of straw and steer manure in a gravel matrix provided a source of organic nutrients and sulfate-reducing
bacteria sufficient to initiate and maintain microbial sulfate reduction up to 270 mmol/m3d. Hydraulic residence times of 2.7 days produced an aqueous thallium effluent concentration below the analytical detection
limit of 2.5 μg/L at 20°C in all the tested columns. These effluent levels were achieved for influent dissolved thallium concentrations
varying from 450 to 790 μg/L. An increase in pH between influent (pH 6.9) and effluents (pH 7.5) was observed. Hydraulic conductivity
remained relatively constant during the course of the experiments and varied for the different test columns between 0.2 and
10 cm/s. The highest k-values were observed in the horizontal flow column. In addition to the column tests, sterile serum-vial
experiments were performed to confirm that thallium sulfide (Tl2S) formation and precipitation was the most likely mechanism for thallium removal. Data from the bench-scale experiments were
utilized for the design of an on-site pilot-scale passive treatment system. 相似文献
7.
Robert S. Hedin 《Mine Water and the Environment》2008,27(4):200-209
The Marchand passive treatment system was constructed in 2006 for a 6,000 L/min discharge from an abandoned underground bituminous
coal mine located in western Pennsylvania, USA. The system consists of six serially connected ponds followed by a large constructed
wetland. Treatment performance was monitored between December 2006 and 2007. The system inflow was alkaline with pH 6.2, 337 mg/L
CaCO3 alkalinity, 74 mg/L Fe, 1 mg/L Mn, and <1 mg/L Al. The final discharge averaged pH 7.5, 214 mg/L CaCO3 alkalinity, and 0.8 mg/L Fe. The settling ponds removed 84% of the Fe at an average rate of 26 g Fe m−2 day−1. The constructed wetland removed residual Fe at a rate of 4 g Fe m−2 day−1. Analyses of dissolved and particulate Fe fractions indicated that Fe removal was limited in the ponds by the rate of iron
oxidation and in the wetland by the rate of particulate iron settling. The treatment effectiveness of the system did not substantially
degrade during cold weather or at high flows. The system cost $1.3 million (2006) or $207 (US) per L/min of average flow.
Annual maintenance and sampling costs are projected at $10,000 per year. The 25-year present value cost estimate (4% discount
rate) is $1.45 million or $0.018 per 1,000 L of treated flow. 相似文献
8.
《Minerals Engineering》2007,20(1):52-59
This work presents the experimental results for arsenic removal from aqueous solutions using pisolite as a natural inorganic sorbent, a waste mineral product from Brazilian manganese ore mines. A pisolite sample was submitted to physical and chemical characterization; particle size analysis by screening, X-ray diffractometry, X-ray fluorescence, surface area determination by the Brunauer–Emmett–Teller (BET) method and atomic absorption spectrophotometry (AA) for the determination of the species concentration in the pisolite and in the aqueous solution samples from the experiments.Column and batch tests to contact pisolite and aqueous feed solutions were carried out for evaluation of the pisolite’s performance as a natural sorbent for arsenic removal. Experiments using activated pisolite and aqueous feed solutions prepared with Velhas River water were also performed. In the column system, 1.0 g of pisolite removed 1.41 mg of As (4.05% As extraction) from 630 ml of the aqueous feed solution and 1.0 g of activated pisolite extracted 3.51 mg of As (11.6% As extraction). Results for the batch tests with 100 ml of aqueous feed solution and 1.0 g of pisolite removed 1.29 mg of As (24.7% As extraction) and 1.0 g of activated pisolite extracted 3.17 mg (58.2% As extraction). 相似文献
9.
Charles A. CravottaIII 《Mine Water and the Environment》2007,26(3):128-149
This report evaluates the results of a continuous 4.5-day laboratory aeration experiment and the first year of passive, aerobic
treatment of abandoned mine drainage (AMD) from a typical flooded underground anthracite mine in eastern Pennsylvania, USA.
During 1991–2006, the AMD source, locally known as the Otto Discharge, had flows from 20 to 270 L/s (median 92 L/s) and water
quality that was consistently suboxic (median 0.9 mg/L O2) and circumneutral (pH ≈ 6.0; net alkalinity >10) with moderate concentrations of dissolved iron and manganese and low concentrations
of dissolved aluminum (medians of 11, 2.2, and <0.2 mg/L, respectively). In 2001, the laboratory aeration experiment demonstrated
rapid oxidation of ferrous iron (Fe2+) without supplemental alkalinity; the initial Fe2+ concentration of 16.4 mg/L decreased to less than 0.5 mg/L within 24 h; pH values increased rapidly from 5.8 to 7.2, ultimately
attaining a steady-state value of 7.5. The increased pH coincided with a rapid decrease in the partial pressure of carbon
dioxide (PCO2) from an initial value of 10−1.1 atm to a steady-state value of 10−3.1 atm. From these results, a staged aerobic treatment system was conceptualized consisting of a 2 m deep pond with innovative
aeration and recirculation to promote rapid oxidation of Fe2+, two 0.3 m deep wetlands to facilitate iron solids removal, and a supplemental oxic limestone drain for dissolved manganese
and trace-metal removal. The system was constructed, but without the aeration mechanism, and began operation in June 2005.
During the first 12 months of operation, estimated detention times in the treatment system ranged from 9 to 38 h. However,
in contrast with 80–100% removal of Fe2+ over similar elapsed times during the laboratory aeration experiment, the treatment system typically removed less than 35%
of the influent Fe2+. Although concentrations of dissolved CO2 decreased progressively within the treatment system, the PCO2 values for treated effluent remained elevated (10−2.4 to 10−1.7 atm). The elevated PCO2 maintained the pH within the system at values less than 7 and hence slowed the rate of Fe2+ oxidation compared to the aeration experiment. Kinetic models of Fe2+ oxidation that consider effects of pH and dissolved O2 were incorporated in the geochemical computer program PHREEQC to evaluate the effects of detention time, pH, and other variables
on Fe2+ oxidation and removal rates. These models and the laboratory aeration experiment indicate that performance of this and other
aerobic wetlands for treatment of net-alkaline AMD could be improved by aggressive, continuous aeration in the initial stage
to decrease PCO2, increase pH, and accelerate Fe2+ oxidation.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
10.
M. de Beer E. H. Mathews D. Krueger J. Maree N. Mbhele M. Phalanndwa O. Novhe 《Mine Water and the Environment》2008,27(1):46-51
Traditionally acid mine water is neutralised with lime. Limestone is a cheaper alternative for such applications. A case study
showed that limestone can be used effectively to replace lime for the neutralization of arsenic rich acid water. The cost
of limestone treatment is 45.8% less than that of lime. The acidity can be removed from 33.5 to 0.06 g/L (as CaCO3). The study also showed no significant differences in the TCLP characteristics of the resultant sludge when water is treated
with lime or with limestone. Sludge from the limestone treatment process can be disposed of on a non-hazardous landfill site.
An erratum to this article can be found at 相似文献
11.
12.
T. Turk 《Mine Water and the Environment》2017,36(2):255-263
Pyrite ash (PA), a waste produced during the roasting of pyrite ores to produce sulfuric acid, was studied as a potential adsorbent for removing arsenic (As) from groundwater. The collected pyrite ash waste samples contained >86 % iron (as Fe2O3). The results indicate that adsorption of As by PA was only slightly affected by initial pH at pH ≤ 9. Arsenate removal efficiency increased with the amount of adsorbent added over the range of 0.1–50 g/L. The As(V) removal increased with time, and 79 % removal was achieved within 1 h. Moreover, there was no significant change in As concentrations after 24 h. The adsorption process was best described by a second-order kinetic model. The adsorption of As(V) onto the PA was found to have followed the Langmuir isotherm. In batch studies, the maximum As(V) removal efficiency was 97 % at an adsorbent dose of 10 g/L, with an initial As(V) concentration of 300 µg/L. Thus, the PA was shown to be a suitable sorbent, reducing As from an initial level of 600 to <10 μg/L As(V), i.e., below the WHO limit for drinking water. 相似文献
13.
The data on arsenic removal from water sources down to the residual concentration below 10 μg/l are reported. The basic physico-chemical
parameters are set for arsenic removal by polystyrene modified by polymer polyHIPE granules, calcium alginate granules saturated
(coated) with iron hydroxide. Adsorption filtration is an efficient method of arsenic removal.
__________
Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 114–123, March–April, 2007. 相似文献
14.
Gammons Christopher H. Poulson Simon R. Metesh John J. Duaime Terence E. Henne Amber R. 《Mine Water and the Environment》2003,22(3):141-148
Abstract.
Groundwater being pumped from the flooded West Camp mine
workings of Butte, Montana, is elevated in hydrogen sulfide
(H2S), has a circum-neutral pH, and has
high arsenic but otherwise low metal concentrations. The daily
flux of H2S and As pumped from the
extraction well are each estimated at roughly 0.1 kg. Isotopic
analysis of coexisting aqueous sulfide and sulfate confirms that
the H2S was produced by bacterial sulfate
reduction. the mine waters are close to equilibrium saturation
with amorphous FeS, amorphous ZnS, siderite, rhodochrosite,
calcite, and goethite, but are undersaturated with orpiment
(As2S3). The
higher solubility of orpiment relative to other mental sulfides
allows concentrations of dissolved arsenic (~ 100 g/L) that are
well above human health standards. The West Camp waters differ
markedly from the acidic and heavy metal-rich mine waters of the
nearby Berkeley pit-lake. These differences are partly
attributed to geology, and partly to mining history. 相似文献
15.
《Minerals Engineering》2006,19(5):521-524
This work shows results of electrocoagulation of solutions containing arsenic. The continuous flow treatment consisted of an electrocoagulation reactor with two parallel iron plates and a sedimentation basin.The results showed that the electrocoagulation process of a 100 mg/L As(V) solution could decrease the arsenic concentration to less than 2 mg/L in the effluent with a current density of 1.2 A/dm2 and a residence time of around 9 min. Liquid flow was 3 L/h, and the DC current was reversed each 2 min.Increasing the current density from 0.8 to 1.2 A/dm2, the Fe3+ and OH− dosages increase too, and thereby favouring the As removal. On the other hand, it seems that increasing the current density beyond a maximum value, the electrocoagulation process would not improve further. This could probably be explained by passivation of the anode. 相似文献
16.
Abstract Mine effluents should be treated so that they can either be re-used (e. g. for mining activities or irrigation purposes) or
discharged into a river system. The results of this study showed that applying laboratory scale biological sulphate removal
technology to a nickel/copper mine effluent (BCL mine, Botswana) consistently lowered sulphate concentrations from an average
of 2000 to 450 mg/L, and increased the pH from 5.8 to 6.5. During this period, the hydraulic retention time varied from 24
to 12 h. The Ni and Zn concentrations were reduced from a maximum of 5.86 to 0.15 mg/L and from a maximum of 38 mg/L to 0.03
mg/L, respectively, presumably precipitated as metal sulphides. 相似文献
17.
Heavy metal-resistant immobilized sulfate-reducing bacteria (SRB) granules were prepared to treat acid mine drainage (AMD) containing high concentrations of multiple heavy metal ions using an up-flow anaerobic packed-bed bioreactor. The bioreactor demonstrated satisfactory performance at influent pH 2.8 and high concentrations of metals (Fe 463 mg/L, Mn 79 mg/L, Cu 76 mg/L, Cd 58 mg/L and Zn 118 mg/L). The effluent pH ranged from 7.8 to 8.3 and the removal efficiencies of Fe, Cu, Zn and Cd were over 99.9% except for Mn (42.1–99.3%). The bacterial community in the bioreactor was diverse and included fermentative bacteria and SRB (Desulfovibrio desulfiricans) involved in sulfate reduction. The co-existing anaerobic fermentative bacteria (Clostridia bacterium, etc.) with the ability to use lactate as electron donor could explain the differences between actual lactate consumption and what would be expected based solely on sulfate reduction. 相似文献
18.
《Minerals Engineering》2006,19(5):486-490
Conventional treatment methods for arsenic removal from copper smelting wastewaters create sludge that is difficult to handle. Biosorption of arsenic using algae as sorbent is an interesting alternative to the conventional methods.This work shows results from biosorption of arsenic(V) by Lessonia nigrescens at pH = 2.5, 4.5 and 6.5. The adsorption of arsenic could be explained satisfactorily both by the Freundlich and the Langmuir isotherms. Maximum adsorption capacities were estimated to 45.2 mg/g (pH = 2.5), 33.3 mg/g (pH = 4.5), and 28.2 mg/g (pH = 6.5) indicating better adsorption at the lower pH. These values are high in comparison with other arsenic adsorbents reported.The sorption kinetics of arsenic by L. nigrescens could be modelled well by Lagergren’s first-order rate equation. The kinetics were observed to be independent of pH during the first 120 min of adsorption with the Lagergren first-order rate constant of around 1.07 × 10−3 min−1. 相似文献
19.
Antimony, a toxic metalloid similar to arsenic, is present at variable levels in most gold-bearing rocks. Antimony is soluble
in the surface environment, so antimony (Sb) mobilization in mine waters is an environmental issue around gold mines. The
Reefton gold mine was originally developed in gold-bearing quartz veins; Sb concentrations were low (<100 mg/kg) compared
to arsenic (As) concentrations (>1,000 mg/kg), and the mine waters had low dissolved Sb (<0.1 mg/L). A second stage of gold
mineralization at Reefton involved brecciation and cataclasis of quartz veins and wall rocks, with addition of stibnite (Sb2S3). Processing of this ore has resulted in higher dissolved Sb in mine waters (0.1–1 mg/L), even after water treatment that
removes most dissolved As (to 0.01 mg/L) by adsorption to suspended iron oxyhydroxide. Competition between As and Sb for adsorption
sites on iron oxyhydroxide particles may have resulted in partial exclusion of the more weakly adsorbed Sb. The high rainfall
(2,000 mm/year) at Reefton ensures adequate dilution of mine waters after discharge. The Macraes gold mine has no stibnite,
and most Sb is in solid solution in the abundant arsenopyrite (Sb up to 2,000 mg/kg). Pit waters have both Sb and As dissolved
up to 0.1 mg/L, partly because of evaporative concentration in a low-rainfall environment. Macraes tailings waters have high
As (up to 3 mg/L) but negligible Sb (<0.001 mg/L). Reefton mine gold-bearing concentrate, containing stibnite, is transported
700 km to be processed by autoclave oxidation and cyanidation at the Macraes mine. This introduction of additional Sb to the
Macraes site substantially increases the Sb content of the process stream periodically. Tailings from this process have up
to 3 wt% Sb, dispersed through As-rich iron oxyhydroxides that are formed in the autoclave. The Sb-rich tailings are strongly
diluted (approximately 100:1) by the Macraes tailings, and adsorption of Sb to iron oxyhydroxides in the tailings piles ensures
that there has been no increase in the Sb content of the tailings water since the Reefton concentrate has been added at Macraes. 相似文献
20.
Tommi Kaartinen Jutta Laine-Ylijoki Sarita Ahoranta Tero Korhonen Raisa Neitola 《Mine Water and the Environment》2017,36(2):199-208
Potential low-cost sorption materials (mostly industrial by-products) were screened for removal of arsenic from mine effluent water. First, the maximum adsorption capacities were determined in batch tests with various liquid to solid ratios. The highest arsenic sorption capacity, 46 mg As/g of sorption material, was measured for cast iron chips. The most promising materials were also studied in batch tests that assessed the reaction kinetics and in kinetic column tests for their behavior in a filter or reactive barrier application. The column tests revealed the cast iron chips caused clogging in the percolation column when operating with real mine water. A commercial ferric oxi-hydroxide sorption material developed for As removal for drinking water showed good As removal in the column tests. Around 10,000 bed volumes of mine process water containing 2 mg/L of arsenic was treated with this material, and treated water concentrations ranged between 0 and 0.05 mg/L before breakthrough. The measured adsorption capacity for the commercial ferric oxi-hydroxide sorption material was 8.3 mg As/g. 相似文献