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Sample records for acid-mine drainage amd

  1. Electricity generation from synthetic acid-mine drainage (AMD) water using fuel cell technologies

    SciTech Connect

    Shaoan Cheng; Brian A. Dempsey; Bruce E. Logan

    2007-12-15

    Acid-mine drainage (AMD) is difficult and costly to treat. We investigated a new approach to AMD treatment using fuel cell technologies to generate electricity while removing iron from the water. Utilizing a recently developed microbial fuel cell architecture, we developed an acid-mine drainage fuel cell (AMD-FC) capable of abiotic electricity generation. The AMD-FC operated in fed-batch mode generated a maximum power density of 290 mW/m{sup 2} at a Coulombic efficiency greater than 97%. Ferrous iron was completely removed through oxidation to insoluble Fe(III), forming a precipitate in the bottom of the anode chamber and on the anode electrode. Several factors were examined to determine their effect on operation, including pH, ferrous iron concentration, and solution chemistry. Optimum conditions were a pH of 6.3 and a ferrous iron concentration above about 0.0036 M. These results suggest that fuel cell technologies can be used not only for treating AMD through removal of metals from solution, but also for producing useful products such as electricity and recoverable metals. Advances being made in wastewater fuel cells will enable more efficient power generation and systems suitable for scale-up. 35 refs., 8 figs.

  2. Effect of Phospholipid on Pyrite Oxidation and Microbial Communities under Simulated Acid Mine Drainage (AMD) Conditions.

    PubMed

    Pierre Louis, Andro-Marc; Yu, Hui; Shumlas, Samantha L; Van Aken, Benoit; Schoonen, Martin A A; Strongin, Daniel R

    2015-07-01

    The effect of phospholipid on the biogeochemistry of pyrite oxidation, which leads to acid mine drainage (AMD) chemistry in the environment, was investigated. Metagenomic analyses were carried out to understand how the microbial community structure, which developed during the oxidation of pyrite-containing coal mining overburden/waste rock (OWR), was affected by the presence of adsorbed phospholipid. Using columns packed with OWR (with and without lipid adsorption), the release of sulfate (SO4(2-)) and soluble iron (FeTot) was investigated. Exposure of lipid-free OWR to flowing pH-neutral water resulted in an acidic effluent with a pH range of 2-4.5 over a 3-year period. The average concentration of FeTot and SO4(2-) in the effluent was ≥20 and ≥30 mg/L, respectively. In contrast, in packed-column experiments where OWR was first treated with phospholipid, the effluent pH remained at ∼6.5 and the average concentrations of FeTot and SO4(2-) were ≤2 and l.6 mg/L, respectively. 16S rDNA metagenomic pyrosequencing analysis of the microbial communities associated with OWR samples revealed the development of AMD-like communities dominated by acidophilic sulfide-oxidizing bacteria on untreated OWR samples, but not on refuse pretreated with phospholipid. PMID:26018867

  3. Geochemical processes controlling fate and transport of arsenic in acid mine drainage (AMD) and natural systems.

    PubMed

    Cheng, Hefa; Hu, Yuanan; Luo, Jian; Xu, Bin; Zhao, Jianfu

    2009-06-15

    Acid mine drainage (AMD) is often accompanied with elevated concentrations of arsenic, in the forms of arsenite, As(III), and/or arsenate, As(V), due to the high affinity of arsenic for sulfide mineral ores. This review summarizes the major geochemical processes controlling the release, speciation, fate, and distribution of inorganic arsenic in mine drainage and natural systems. Arsenic speciation depends highly on redox potential and pH of the solution, and arsenite can be oxidized to the less toxic arsenate form. Homogeneous oxidation of arsenite occurs rather slowly while its heterogeneous oxidation on mineral surfaces can greatly enhance the reaction rates. Little evidence suggests that precipitation reaction limits the concentrations of arsenic in natural water, while co-precipitation may lead to rapid arsenic removal when large amount of iron hydroxides precipitate out of the aqueous phase upon neutralization of the mine drainage. Both arsenate and arsenite adsorb on common metal oxides and clay minerals through formation of inner-sphere and/or outer-sphere complexes, controlling arsenic concentration in natural water bodies. Arsenite adsorbs less strongly than arsenate in the typical pH range of natural water and is more mobile. Part of the adsorbed arsenic species can be exchanged by common anions (e.g., PO(4)(3-) and SO(4)(2-)), especially phosphate, which leads to their re-mobilization. Understanding the geochemistry of arsenic is helpful for predicting its mobility and fate in AMD and natural systems, and for designing of cost-effective remediation/treatment strategies to reduce the occurrence and risk of arsenic contamination. PMID:19070955

  4. Removal of heavy metals from acid mine drainage (AMD) using coal fly ash, natural clinker and synthetic zeolites.

    PubMed

    Ríos, C A; Williams, C D; Roberts, C L

    2008-08-15

    Acid mine drainage (AMD) is a widespread environmental problem associated with both working and abandoned mining operations, resulting from the microbial oxidation of pyrite in presence of water and air, affording an acidic solution that contains toxic metal ions. The generation of AMD and release of dissolved heavy metals is an important concern facing the mining industry. The present study aimed at evaluating the use of low-cost sorbents like coal fly ash, natural clinker and synthetic zeolites to clean-up AMD generated at the Parys Mountain copper-lead-zinc deposit, Anglesey (North Wales), and to remove heavy metals and ammonium from AMD. pH played a very important role in the sorption/removal of the contaminants and a higher adsorbent ratio in the treatment of AMD promoted the increase of the pH, particularly using natural clinker-based faujasite (7.70-9.43) and the reduction of metal concentration. Na-phillipsite showed a lower efficiency as compared to that of faujasite. Selectivity of faujasite for metal removal was, in decreasing order, Fe>As>Pb>Zn>Cu>Ni>Cr. Based on these results, the use of these materials has the potential to provide improved methods for the treatment of AMD. PMID:18221835

  5. Polonium behaviour in reservoirs potentially affected by acid mine drainage (AMD) in the Iberian Pyrite Belt (SW of Spain).

    PubMed

    Blasco, M; Gázquez, M J; Pérez-Moreno, S M; Grande, J A; Valente, T; Santisteban, M; de la Torre, M L; Bolívar, J P

    2016-02-01

    The province of Huelva is one of the areas most affected by acid mine drainage (AMD) in the world, which can produce big enhancements and fractionations in the waters affected by AMD. There are very few studies on this issue, and none on polonium-210. Twenty-two water reservoirs were sampled, and the (210)Po was measured in both dissolution and particulate phases. The (210)Po concentrations in the waters were in the same order of magnitude to those ones for unperturbed systems, although the data published to particulate matter are very scarce. A mean value and standard uncertainty for (210)Po of 0.25 ± 0.03 mBq L(-1) in the dissolved matter, and 62 ± 9 mBq g(-1) in the particulate matter can be established as base line for the reservoirs of the Huelva area. The distribution coefficients (kd) range from 10(4) to 10(6) L kg(-1), in agreement to the found ones by other authors for the case of neutral waters, but being the lowest values for the more acidic reservoirs. It has been also found that (210)Po has a high tendency to be associated to the particulate matter for neutral-alkaline waters, however, under extreme acid conditions (pH < 3), increases the Po tendency to be associated to the dissolved phase. Therefore, the main conclusion obtained in this work is that AMD has no a significant influence on the total activity concentration of (210)Po in the waters of reservoirs, but the acidity has a clear influence on its distribution between both dissolved and the particulate phases. PMID:26650826

  6. As(III) and As(V) removal from the aqueous phase via adsorption onto acid mine drainage sludge (AMDS) alginate beads and goethite alginate beads.

    PubMed

    Lee, Hongkyun; Kim, Dohyeong; Kim, Jongsik; Ji, Min-Kyu; Han, Young-Soo; Park, Young-Tae; Yun, Hyun-Shik; Choi, Jaeyoung

    2015-07-15

    Acid mine drainage sludge (AMDS) is a solid waste generated following the neutralization of acid mine drainage (AMD). This material entrapped in calcium alginate was investigated for the sorption of As(III) and As(V). Three different adsorbent materials were prepared: AMDS alginate beads (AABs), goethite alginate beads (GABs), and pure alginate beads. The effects of pH and the adsorption kinetics were investigated, and the adsorption isotherms were also evaluated. The optimum pH range using the AABs was determined to be within 2-10 for As(III) and 2-9 for As(V). Adsorption equilibrium data were evaluated using the Langmuir isotherm model, and the maximum adsorption capacity qmax was 18.25 and 4.97 mg g(-1) for As(III) on AAB and GAB, respectively, and 21.79 and 10.92 mg g(-1) for As(V) on AAB and GAB, respectively. The adsorption of As(III) and As(V) was observed to follow pseudo-second order kinetics. The As K-edge X-ray absorption near-edge structure (XANES) revealed that the adsorbed As(III) on the AABs was oxidized to As(V) via manganese oxide in the AMDS. PMID:25804789

  7. Haneş and Valea Vinului (Romania) closed mines Acid Mine Drainages (AMDs)--actual condition and passive treatment remediation proposal.

    PubMed

    Măicăneanu, Andrada; Bedelean, Horea; Ardelean, Marius; Burcă, Silvia; Stanca, Maria

    2013-10-01

    Acid Mine Drainages (AMDs) from Haneş and Valea Vinului (Romania) closed mines were considered for characterization and treatment using a local zeolitic volcanic tuff, ZVT, (Măcicaş, Cluj County, Romania). Water samples were collected from two locations, before and after discharging point in case of Haneş mine, and on three horizons in case of Valea Vinului mine. Physico-chemical (pH, total solid, heavy metal ions concentration) analyses showed that the environment is strongly affected by these AMD discharges even if the mines were closed years ago. Iron, manganese and zinc were the main pollutants identified in Haneş mine AMD, while zinc is the one mainly present in case of Valea Vinului AMD. A batch technique (no stirring) in which the ZVT was put in contact with the AMD sample was proposed as a passive remediation technique. ZVT successfully remove heavy metal ion from AMD. According to heavy metal ion concentrations, removal efficiencies are reaching 100%, varying as follows, Fe(2+)>Zn(2+)>Mn(2+). When the ZVT was compared with two cationic resins (strong, SAR and weak acid, WAR) the following series was depicted, SAR>ZVT>WAR. PMID:23899925

  8. GROUNDWATER IMPACTED BY ACID MINE DRAINAGE

    EPA Science Inventory

    The generation and release of acidic, metal-rich water from mine wastes continues to be an intractable environmental problem. Although the effects of acid mine drainage (AMD) are most evident in surface waters, there is an obvious need for developing cost-effective approaches fo...

  9. FISH HABITATS IMPACTED BY ACIDIC MINE DRAINAGE

    EPA Science Inventory

    This data set represents in-stream fish spawning and hatching areas that have been impacted by elevated acid content waters discharging from areas near mining activities. It is based on an EPA fisheries survey completed in 1995. Acid Mine Drainage, or AMD, occurs when water co...

  10. DEVELOPMENT OF SRB TREATMENT SYSTEMS FOR ACID MINE DRAINAGE

    EPA Science Inventory

    Over the past decade, significant advances have been made in the development of sulfate- reducing bacteria (SRB) technology to treat acid mine drainage (AMD), Bench-scale testing, field demonstrations, and engineered applications of SRBs for the treatment of AMD will be presented...

  11. Treatment of combined acid mine drainage (AMD)--flotation circuit effluents from copper mine via Fenton's process.

    PubMed

    Mahiroglu, Ayse; Tarlan-Yel, Esra; Sevimli, Mehmet Faik

    2009-07-30

    The treatability of a copper mine wastewater, including heavy metals, AMD, as well as flotation chemicals, with Fenton process was investigated. Fenton process seems advantageous for this treatment, because of Fe(2+) content and low pH of AMD. First, optimum Fe(2+) condition under constant H(2)O(2) was determined, and initial Fe(2+) content of AMD was found sufficient (120 mg/L for removal of chemical oxygen demand (COD) of 6125 mg/L). In the second step, without any additional Fe(2+), optimum H(2)O(2) dosage was determined as 40 mg/L. Fe(2+)/H(2)O(2) molar ratio of 1.8 was enough to achieve the best treatment performance. In all trials, initial pH of AMD was 4.8 and pH adjustment was not performed. Utilization of existing pH and Fe(2+), low H(2)O(2) requirements, and up to 98% treatment performances in COD, turbidity, color, Cu(2+), Zn(2+) made the proposed treatment system promising. Since the reaction occurs stepwise, a two-step kinetic model was applied and calculated theoretical maximum removal rate was consistent to experimental one, which validates the applied model. For the optimum molar ratio (1.8), 140 mL/L sludge of high density (1.094 g/mL), high settling velocity (0.16 cm/s) with low specific resistance (3.15 x 10(8)m/kg) was obtained. High reaction rates and easily dewaterable sludge characteristics also made the proposed method advantageous. PMID:19147282

  12. LIME TREATMENT LAGOONS TECHNOLOGY FOR TREATING ACID MINE DRAINAGE

    EPA Science Inventory

    Active and inactive mines can produce runoff and drainage that are among the most environmentally damaging processes affecting land in the United States. Acid mine drainage (AMD) from mining sites across the country requires treatment because of high metal concentrations that exc...

  13. Influence of Acid Mine Drainage (AMD) on recent phyto- and zooplankton in "the Anthropogenic Lake District" in south-west Poland

    NASA Astrophysics Data System (ADS)

    Sienkiewicz, Elwira; Gasiorowski, Michal

    2015-04-01

    In south-west Poland (central Europe) many the post-mining lakes formed so-called "the Anthropogenic Lake District". Areas, where water comes in contact with lignite beds characterized by high concentration of sulfide minerals are called Acid Mine Drainage (AMD). Pyrite oxidation and other sulfide compounds caused release sulfuric acids and heavy metal ions. These processes caused decline of water pH, sometimes to extremely low pH < 2.8. Presently, pit lakes located in south-west Poland have water pH ranged between 2.7 and 8.9. Differences of water reaction in the mine lakes depend on many factors, such as bedrock buffer capacity, geological structure of carboniferous area, exploitation technique of lignite, methods of filling and water supply of reservoirs and their age. During the evolution of lakes' ecosystems, sulfate-iron-calcium type of waters occurring in acid lakes will transform in alkaline hydrogen-carbonate-calcium type of waters. Due to the different time of the completion of lignite exploitation, lakes' age varied between forty and over one hundred years. Studies showed that younger lakes are more acidic in compare to older. To estimate impact of AMD we analyzed recent diversity of diatoms and Cladocera remains and water chemistry from extremely acidic, relatively young lakes and from alkaline, older water bodies. As we expected, flora and fauna from acidic lakes have shown very low diversity and species richness. Among diatoms, Eunotia exigua (Bréb. ex Kütz.) Rabenhorst and/or E. paludosa Grunow were dominated taxa, while fauna Cladocera did not occurred in lakes with water pH < 3. On this area, exploitation of lignite continued up to 1973. Older lakes were formed in the region where the mine started work in 1880 and lignite mining stopped in 1926. Measurements of pH value in situ point to neutral or alkaline water, but because of the possibility of hysteresis phenomenon, the studies of phyto- and zooplankton have shown if there has already been a

  14. Microbial communities in acid mine drainage.

    PubMed

    Baker, Brett J; Banfield, Jillian F

    2003-05-01

    The dissolution of sulfide minerals such as pyrite (FeS2), arsenopyrite (FeAsS), chalcopyrite (CuFeS2), sphalerite (ZnS), and marcasite (FeS2) yields hot, sulfuric acid-rich solutions that contain high concentrations of toxic metals. In locations where access of oxidants to sulfide mineral surfaces is increased by mining, the resulting acid mine drainage (AMD) may contaminate surrounding ecosystems. Communities of autotrophic and heterotrophic archaea and bacteria catalyze iron and sulfur oxidation, thus may ultimately determine the rate of release of metals and sulfur to the environment. AMD communities contain fewer prokaryotic lineages than many other environments. However, it is notable that at least two archaeal and eight bacterial divisions have representatives able to thrive under the extreme conditions typical of AMD. AMD communities are characterized by a very limited number of distinct species, probably due to the small number of metabolically beneficial reactions available. The metabolisms that underpin these communities include organoheterotrophy and autotrophic iron and sulfur oxidation. Other metabolic activity is based on anaerobic sulfur oxidation and ferric iron reduction. Evidence for physiological synergy in iron, sulfur, and carbon flow in these communities is reviewed. The microbial and geochemical simplicity of these systems makes them ideal targets for quantitative, genomic-based analyses of microbial ecology and evolution and community function. PMID:19719632

  15. Microbial communities, processes and functions in acid mine drainage ecosystems.

    PubMed

    Chen, Lin-Xing; Huang, Li-Nan; Méndez-García, Celia; Kuang, Jia-Liang; Hua, Zheng-Shuang; Liu, Jun; Shu, Wen-Sheng

    2016-04-01

    Acid mine drainage (AMD) is generated from the oxidative dissolution of metal sulfides when water and oxygen are available largely due to human mining activities. This process can be accelerated by indigenous microorganisms. In the last several decades, culture-dependent researches have uncovered and validated the roles of AMD microorganisms in metal sulfides oxidation and acid generation processes, and culture-independent studies have largely revealed the diversity and metabolic potentials and activities of AMD communities, leading towards a full understanding of the microbial diversity, functions and interactions in AMD ecosystems. This review describes the diversity of microorganisms and their functions in AMD ecosystems, and discusses their biotechnological applications in biomining and AMD bioremediation according to their capabilities. PMID:26921733

  16. Mineralogical transformations controlling acid mine drainage chemistry

    SciTech Connect

    Peretyazhko, Tetyana; Zachara, John M.; Boily, Jean F.; Xia, Yuanxian; Gassman, Paul L.; Arey, Bruce W.; Burgos, William D.

    2009-05-30

    The role of Fe(III) minerals in controlling acid mine drainage (AMD) chemistry was studied using samples from two AMD sites [Gum Boot (GB) and Fridays-2 (FR)] located in northern Pennsylvania. Chemical extractions, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to identify and characterize Fe(III) phases. The mineralogical analysis revealed that schwertmannite and goethite were the principal Fe(III) phases in the sediments. Schwertmannite transformation occurred at the GB site where poorly-crystallized goethite rich in surface-bound sulfate was initially formed. In contrast, no schwertmannite transformation occurred at the FR site. The goethite in GB sediments had spherical morphology due to preservation of schwertmannite structure by adsorbed sulfate. Results of chemical extractions showed that poorly-crystallized goethite was subject to further crystallization accompanied by sulfate desorption. Changes in sulfate speciation preceded its desorption, with a conversion of bidentate- to monodentate-bound sulfate surface complexes. Laboratory sediment incubation experiments were conducted to evaluate the effect of mineral transformation on water chemistry. Incubation experiments were carried out with schwertmannite-containing sediments and AMD waters with different pH and chemical composition. The pH decreased to 1.9-2.2 in all suspensions and the concentrations of dissolved Fe and S increased significantly. Regardless of differences in the initial water composition, pH, Fe and S were similar in suspensions of the same sediment. XRD measurements revealed that schwertmannite transformed into goethite in GB and FR sediments during laboratory incubation. The incubation experiment demonstrated that schwertmannite transformation controlled AMD water chemistry during “closed system” laboratory contact.

  17. Sulfate reduction in freshwater sediments receiving Acid mine drainage.

    PubMed

    Herlihy, A T; Mills, A L

    1985-01-01

    One arm of Lake Anna, Va., receives acid mine drainage (AMD) from Contrary Creek (SO(4) concentration = 2 to 20 mM, pH = 2.5 to 3.5). Acid-volatile sulfide concentrations, SO(4) reduction rates, and interstitial SO(4) concentrations were measured at various depths in the sediment at four stations in four seasons to assess the effects of the AMD-added SO(4) on bacterial SO(4) reduction. Acid-volatile sulfide concentrations were always an order of magnitude higher at the stations receiving AMD than at a control station in another arm of the lake that received no AMD. Summer SO(4) reduction rates were also an order of magnitude higher at stations that received AMD than at the control station (226 versus 13.5 mmol m day), but winter values were inconclusive, probably due to low sediment temperature (6 degrees C). Profiles of interstitial SO(4) concentrations at the AMD stations showed a rapid decrease with depth (from 1,270 to 6 muM in the top 6 cm) due to rapid SO(4) reduction. Bottom-water SO(4) concentrations in the AMD-receiving arm were highest in winter and lowest in summer. These data support the conclusion that there is a significant enhancement of SO(4) reduction in sediments receiving high SO(4) inputs from AMD. PMID:16346696

  18. Sulfate Reduction in Freshwater Sediments Receiving Acid Mine Drainage

    PubMed Central

    Herlihy, Alan T.; Mills, Aaron L.

    1985-01-01

    One arm of Lake Anna, Va., receives acid mine drainage (AMD) from Contrary Creek (SO42− concentration = 2 to 20 mM, pH = 2.5 to 3.5). Acid-volatile sulfide concentrations, SO42− reduction rates, and interstitial SO42− concentrations were measured at various depths in the sediment at four stations in four seasons to assess the effects of the AMD-added SO42− on bacterial SO42− reduction. Acid-volatile sulfide concentrations were always an order of magnitude higher at the stations receiving AMD than at a control station in another arm of the lake that received no AMD. Summer SO42− reduction rates were also an order of magnitude higher at stations that received AMD than at the control station (226 versus 13.5 mmol m−2 day−1), but winter values were inconclusive, probably due to low sediment temperature (6°C). Profiles of interstitial SO42− concentrations at the AMD stations showed a rapid decrease with depth (from 1,270 to 6 μM in the top 6 cm) due to rapid SO42− reduction. Bottom-water SO42− concentrations in the AMD-receiving arm were highest in winter and lowest in summer. These data support the conclusion that there is a significant enhancement of SO42− reduction in sediments receiving high SO42− inputs from AMD. PMID:16346696

  19. VALUING ACID MINE DRAINAGE REMEDIATION IN WEST VIRGINIA: A HEDONIC MODELING APPROACH

    EPA Science Inventory

    States with active and abandoned mines face large private and public costs to remediate damage to streams and rivers from acid mine drainage (AMD). Appalachian states have an especially large number of contaminated streams and rivers, and the USGS places AMD as the primary source...

  20. VALUING ACID MINE DRAINAGE REMEDIATION IN WEST VIRGINIA: A HEDONIC MODELING APPROACH INCORPORATING GEOGRAPHIC INFORMATION SYSTEMS

    EPA Science Inventory

    States with active and abandoned mines face large private and public costs to remediate damage to streams and rivers from acid mine drainage (AMD). Appalachian states have an especially large number of contaminated streams and rivers, and the USGS places AMD as the primary source...

  1. MECHANISMS OF HEAVY METAL REMOVAL FROM ACID MINE DRAINAGE USING CHITIN

    EPA Science Inventory

    Acid Mine Drainage (AMD) emanating from inactive or active mine sites contains elevated levels of toxic heavy metals, which can have an adverse impact to the surrounding environment. The major pathway involved in generation of AMD is weathering of pyritic mineral ores, where in s...

  2. VALUING ACID MINE DRAINAGE REMEDIATION OF IMPAIRED WATERWAYS IN WEST VIRGINIA: A HEDONIC MODELING APPROACH

    EPA Science Inventory

    States with active and abandoned mines face large private and public costs to remediate damage to streams and rivers from acid mine drainage (AMD), the metal rich runoff flowing primarily from abandoned mines and surface deposits of mine waste. AMD can lower stream and river pH ...

  3. PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT MINE HIGHWALLS

    EPA Science Inventory



    Exposed, open pit mine highwalls contribute significantly to the production of acid mine

    drainage (AMD) thus causing environmental concerns upon closure of an operating mine. Available information on the generation of AMD from open-pit mine highwalls is very limit...

  4. LIME TREATMENT LAGOONS TECHNOLOGY FOR TREATING ACID MINE DRAINAGE FROM TWO MINING SITES

    EPA Science Inventory

    Runoff and drainage from active and inactive mines are someof the most environmentally damaging land uses i the US. Acid Mine drainage (AMD) from mining sites across the country requires treatment because of high metal concentrations that exceed regulatory standards for safe disc...

  5. Sulfate reduction in freshwater sediments receiving acid mine drainage

    SciTech Connect

    Herlihy, A.T.; Mills, A.L.

    1985-01-01

    One arm of Lake Anna, Va., receives acid mine drainage (AMD) from Contrary Creek (SO/sub 4//sup 2 -/ concentration = 2 to 20 mM, pH = 2.5 to 3.5). Acid-volatile sulfide concentrations, SO/sub 4//sup 2 -/ reduction rates, and interstitial SO/sub 4//sup 2 -/ concentrations were measured at various depths in the sediment at four stations in four seasons to assess the effects of the AMD-added SO/sub 4//sup 2 -/ on bacterial SO/sub 4//sup 2 -/ reduction. Acid-volatile sulfide concentrations were always an order of magnitude higher at the stations receiving AMD than at a control station in another arm of the lake that received no AMD. Summer SO/sub 4//sup 2 -/ reduction rates were also an order of magnitude higher at stations that received AMD than at the control station (226 versus 13.5 mmol m/sup -2/ day/sup -1/), but winter values were inconclusive, probably due to low sediment temperature (6/sup 0/C). Profiles of interstitial SO/sub 4//sup 2 -/ concentrations at the AMD stations showed a rapid decrease with depth (from 1270 to 6 ..mu..M in the top 6 cm) due to rapid SO/sub 4//sup 2 -/ reduction. Bottom-water SO/sub 4//sup 2 -/ concentrations in the AMD-receiving arm were highest in winter and lowest in summer. These data support the conclusion that there is a significant enhancement of SO/sub 4//sup 2 -/ reduction in sediments receiving high SO/sub 4//sup 2 -/ inputs from AMD.

  6. Sequestration of phosphorus by acid mine drainage floc

    USGS Publications Warehouse

    Adler, P.R.; Sibrell, P.L.

    2003-01-01

    Solubilization and transport of phosphorus (P) to the water environment is a critical environmental issue. Flocs resulting from neutralizing acid mine drainage (AMD) were tested as a possible lowcost amendment to reduce the loss of soluble P from agricultural fields and animal wastewater. Flocs were prepared by neutralizing natural and synthetic solutions of AMD with limestone, lime, ammonium hydroxide, and sodium hydroxide. Phosphorus sequestration was tested in three distinct environments: water, soil, and manure storage basins. In water, flocs prepared from AMD adsorbed 10 to 20 g P kg-1 dry floc in equilibrium with 1 mg L-1 soluble P. Similar results were observed for both Fe-based and A1-based synthetic flocs. A local soil sample adsorbed about 0.1 g P kg-1, about two orders of magnitude less. The AMD-derived flocs were mixed with a highP soil at 5 to 80 g floc kg-1 soil, followed by water and acid (Mehlich1) extractions. All flocs performed similarly. About 70% of the waterextractable P was sequestered by the floc when applied at a rate of 20 g floc kg-1 soil, whereas plant-available P only decreased by about 30%. Under anaerobic conditions simulating manure storage basins, all AMD flocs reduced soluble P by greater than 95% at a rate of 0.2 g floc g-1 rainbow trout (Oncorhynchus mykiss) manure. These findings indicate that AMD flocs could be an effective agent for preventing soluble P losses from soil and manure to the water environment, while at the same time decreasing the costs associated with AMD treatment.

  7. Phosphorus removal performance of acid mine drainage from wastewater.

    PubMed

    Ruihua, Li; Lin, Zhu; Tao, Tao; Bo, Liu

    2011-06-15

    Acid mine drainage (AMD) in Yunfu iron sulfide mine contain Fe(2+), Fe(3+), and Al(3+) up to 8000, 1700 and 1200 mg/L, respectively. Phosphorus removal from synthetic wastewater with 10mg/L of total phosphorus (TP) concentration and second municipal effluent with 3.5-4.0mg/L of TP concentration were conducted with the AMD by jar tests. Dosage of the AMD and initial pH of water are the two most important parameters affecting the performance of phosphorus removal of the AMD. The optimal phosphorus removal efficiency and residual iron ions (TFe) concentration are 97.0% and 3.0mg/L, respectively, at 1.61 Fe/P molar ratio and pH 8.03 for synthetic wastewater, and 92.1% and 0.32 mg/L, respectively, for second municipal effluent at 1.41 Fe/P molar ratio and pH 7.3. Resultant heavy metal concentration in effluents and precipitate was very low, and the risk of resultant heavy metal contamination was very small. The phosphorus removal performance of the AMD was much similar to that of ferric sulfate (FS) and polyferric sulfate (PFS), and better than that of FeSO(4). And residual TFe concentration in treated water arising from utilization of the AMD was similar to that of FeSO(4), and higher than that of FS and PFS. The AMD could be used as coagulant for phosphorus removal from wastewater directly due to the presence of Fe(2+), Fe(3+), and Al(3+) largely. PMID:21514994

  8. Microbial diversity and metabolic networks in acid mine drainage habitats

    PubMed Central

    Méndez-García, Celia; Peláez, Ana I.; Mesa, Victoria; Sánchez, Jesús; Golyshina, Olga V.; Ferrer, Manuel

    2015-01-01

    Acid mine drainage (AMD) emplacements are low-complexity natural systems. Low-pH conditions appear to be the main factor underlying the limited diversity of the microbial populations thriving in these environments, although temperature, ionic composition, total organic carbon, and dissolved oxygen are also considered to significantly influence their microbial life. This natural reduction in diversity driven by extreme conditions was reflected in several studies on the microbial populations inhabiting the various micro-environments present in such ecosystems. Early studies based on the physiology of the autochthonous microbiota and the growing success of omics-based methodologies have enabled a better understanding of microbial ecology and function in low-pH mine outflows; however, complementary omics-derived data should be included to completely describe their microbial ecology. Furthermore, recent updates on the distribution of eukaryotes and archaea recovered through sterile filtering (herein referred to as filterable fraction) in these environments demand their inclusion in the microbial characterization of AMD systems. In this review, we present a complete overview of the bacterial, archaeal (including filterable fraction), and eukaryotic diversity in these ecosystems, and include a thorough depiction of the metabolism and element cycling in AMD habitats. We also review different metabolic network structures at the organismal level, which is necessary to disentangle the role of each member of the AMD communities described thus far. PMID:26074887

  9. Bioremediation of acid mine drainage coupled with domestic wastewater treatment.

    PubMed

    Sánchez-Andrea, Irene; Triana, David; Sanz, Jose L

    2012-01-01

    Acid mine drainage (AMD) - characterized by high acidity and elevated sulfate and metal concentrations - represents a big environmental concern. Biological sulfate reduction has become an alternative to the classical physicochemical methods. In this study, domestic wastewater (DW) was tested as a cost-effective carbon-source for the remediation of AMD. Sediments from Tinto River, an extreme acidic environment with an elevated concentration of metals, were used as inoculum. Three anaerobic bioreactors with different microbial supports were fed with a 1:10 (v:v) mixture of synthetic AMD:DW. Around 50% of the organic matter present in the DW co-precipitated with the metals from the AMD previous to feeding the reactor. Therefore, the reactors had to be supplemented with an extra carbon-source (acetate) to achieve higher S elimination. Elevated removal efficiencies of chemical oxygen demand (COD) (>88%), sulfate (>75%), Fe (>85%) and other dissolved metals (>99% except for Mn) were achieved. Bacterial communities were examined through denaturing gradient gel electrophoresis and scanning electron microscopy. Higher biodiversity was found in the bioreactors compared with that of the inoculum. Dominant species belong to two metabolic groups: fermentative (Clostridium spp., Delftia spp., Paludibacter spp. and Pelotomaculum spp.) and sulfate-reducing bacteria (Desulfomonile spp., Desulfovibrio spp., Desulfosporosinus spp. and Desulfotomaculum spp.). PMID:23032774

  10. Remediation of acid mine drainage with sulfate reducing bacteria

    SciTech Connect

    Hauri, J.F.; Schaider, L.A.

    2009-02-15

    Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed changes in dissolved metal concentrations and pH. Using synthetic acid mine drainage and combinations of inputs, students monitor their bioreactors for decreases in dissolved copper and iron concentrations.

  11. LABORATORY EVALUATION OF ZERO-VALENT IRON TO TREAT GROUNDWATER IMPACTED BY ACID MINE DRAINAGE

    EPA Science Inventory

    The generation and release of acidic, metal-rich water from mine wastes continues to be an intractable environmental problem. Although the effects of acid mine drainage (AMD) are most evident in surface waters, there is an obvious need for developing cost-effective approaches fo...

  12. VALUING ACID MINE DRAINAGE REMEDIATION IN WEST VIRGINIA: BENEFIT TRANSFER WITH PREFERENCE CALIBRATION

    EPA Science Inventory

    Several thousand kilometers of West Virginia streams are degraded by acid mine drainage (AMD), and the estimates for cleanup range in the billions of dollars. Not enough money is available to restore all the affected streams, so some way to prioritize those streams is needed. Ben...

  13. Preliminary Results: Release Of Metals From Acid-Mine Drainage Contaminated Streambed Sediments Under Anaerobic Conditions

    EPA Science Inventory

    Many miles of streams in the western U.S. are contaminated with acid-mine drainage (AMD) from abandoned metal mines. Treatment of these streams may include removal of the existing sediments, with subsequent burial (e.g., in a repository). Burial of previously aerobic sediments ma...

  14. Evaluation of the toxic and genotoxic potential of acid mine drainage using physicochemical parameters and bioassays.

    PubMed

    Netto, E; Madeira, R A; Silveira, F Z; Fiori, M A; Angioleto, E; Pich, C T; Geremias, R

    2013-05-01

    Carboniferous activity generates acid mine drainage (AMD) which is capable of unleashing toxic effects on the exposed biota. The aim of this study was to evaluate the toxic and genotoxic potential of untreated-AMD and AMD treated with calcinated sediment, using physicochemical parameters and bioassays. Results revealed that untreated-AMD presented low pH values and elevated concentrations of the metals Fe, Al, Mn, Zn and Cu. High acute toxicity was observed in Artemia sp. and Daphnia magna, and sub-chronic toxicity and genotoxicity in Allium cepa L. as well as scission of plasmid DNA exposed to untreated-AMD. Treatment of AMD with calcinated sediment promoted the reduction of acidity and the removal of metals, as well as a reduction in toxic and genotoxic effects. In conclusion, the calcinated sediment can be used as an alternative AMD treatment. PMID:23518284

  15. ADVANCES IN BIOTREATMENT OF ACID MINE DRAINAGE AND BIORECOVERY OF METALS: 1. METAL PRECIPITATION FOR RECOVERY AND RECYCLE

    EPA Science Inventory

    Acid-mine drainage (AMD) is a severe pollution problem attributed to past mining activities. AMD is an acidic, metal-bearing wastewater generated by the oxidation of metal sulfides to sulfates by Thiobacillus bacteria in both active and abandoned mining operations. The wastewater...

  16. ADVANCES IN BIOTREATMENT OF ACID MINE DRAINAGE AND BIORECOVERY OF METALS: 2. MEMBRANE BIOREACTOR SYSTEM FOR SULFATE REDUCTION

    EPA Science Inventory

    Acid-mine drainage (AMD) is a severe pollution problem attributed to past mining activities. AMD is an acidic, metal-bearing wastewater generated by the oxidation of metal sulfides to sulfates by Thiobacillus bacteria in both the active and abandoned mining operations. The wastew...

  17. Remediation of Acid Mine Drainage with Sulfate Reducing Bacteria

    ERIC Educational Resources Information Center

    Hauri, James F.; Schaider, Laurel A.

    2009-01-01

    Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed…

  18. Chemical abatement of acid mine drainage formation

    SciTech Connect

    Steven, J.

    1987-01-01

    Chemical and thermodynamic data were used to develop a unified model of hydroxo-, sulfato-, and bisulfato-iron complexes and their stability constants in iron-sulfate solutions. Free energy of formation for each ligand series species was hypothesized to be linear in ligand number because of supporting evidence from the literature. Laboratory tests on the inhibition of acid mine drainage bacteria were conducted. Benzoic acid, sorbic acid, and sodium lauryl sulfate at low concentrations (5 to 10 mg/liter) each effectively inhibited oxidation of ferrous iron in batch cultures of Thiobacillus ferrooxidans. The rate of chemical oxidation of ferrous iron in low-pH, sterile batch reactors was not substantially affected at the tested concentrations (5 to 50 mg/liter) of any of the compounds. Low-pH cultures of Thiobacillus thioxidans significantly increased zinc sulfide dissolution rates relative to sterile controls. Sodium lauryl sulfate, benzoic acid, and sorbic acid at concentrations of 10, 25, and 50 mg/liter, respectively, in identical low-pH, batch cultures of Thiobacillus thiooxidans, were sufficient for complete inhibition of bacterial zinc sulfide dissolution. Pilot-scale experiments on the abatement of acid mine drainage formation in both fresh and weathered pyritic coal refuse were also conducted. At doses of 0.5 g/kg and 5.0 g/kg in fresh and weathered refuse, respectively, sodium benzoate, potassium sorbate, and most significantly, sodium lauryl surface, reduced the rate of iron, sulfate, and acidity production in water-leached barrels of coal refuse material.

  19. Influence of elevated temperature and acid mine drainage on mortality of the crayfish Cambarus bartonii

    USGS Publications Warehouse

    Hartman, K.J.; Hom, C.D.; Mazik, P.M.

    2010-01-01

    Effects of elevated temperature and acid mine drainage (AMD) on crayfish mortality were investigated in the Stony River, Grant County, West Virginia. During summers 2003 and 2004, four-week in situ bioassays were performed along a thermal and AMD gradient with the native crayfish Cambarus bartonii. Crayfish mortality was analyzed in conjunction with temperature and AMD related variables (pH, specific conductivity). Mortality was significantly higher (48-88%) at sites with high temperatures during 2003 (max = 33.0??C), but no significant differences were observed in 2004 (max = 32.0??C). Temperatures were higher in 2003 than 2004 due to increased discharge from a cooling reservoir flowing into the river. Additionally, duration of high temperature was approximately four days in 2003 as compared with only one day in 2004. No significant relationship between acid mine drainage variables and crayfish mortality was apparent.

  20. Precipitation of heavy metals from acid mine drainage and their geochemical modeling

    NASA Astrophysics Data System (ADS)

    Petrilakova, Aneta; Balintova, Magdalena; Holub, Marian

    2014-06-01

    Geochemical modeling plays an increasingly vital role in a number of areas of geoscience, ranging from groundwater and surface water hydrology to environmental preservation and remediation. Geochemical modeling is also used to model the interaction processes at the water - sediment interface in acid mine drainage (AMD). AMD contains high concentrations of sulfate and dissolved metals and it is a serious environmental problem in eastern Slovakia. The paper is focused on comparing the results of laboratory precipitation of metal ions from AMD (the Smolnik creek, Slovakia) with the results obtained by geochemical modeling software Visual Minteq 3.0.

  1. Metabolically Active Eukaryotic Communities in Extremely Acidic Mine Drainage

    PubMed Central

    Baker, Brett J.; Lutz, Michelle A.; Dawson, Scott C.; Bond, Philip L.; Banfield, Jillian F.

    2004-01-01

    Acid mine drainage (AMD) microbial communities contain microbial eukaryotes (both fungi and protists) that confer a biofilm structure and impact the abundance of bacteria and archaea and the community composition via grazing and other mechanisms. Since prokaryotes impact iron oxidation rates and thus regulate AMD generation rates, it is important to analyze the fungal and protistan populations. We utilized 18S rRNA and beta-tubulin gene phylogenies and fluorescent rRNA-specific probes to characterize the eukaryotic diversity and distribution in extremely acidic (pHs 0.8 to 1.38), warm (30 to 50°C), metal-rich (up to 269 mM Fe2+, 16.8 mM Zn, 8.5 mM As, and 4.1 mM Cu) AMD solutions from the Richmond Mine at Iron Mountain, Calif. A Rhodophyta (red algae) lineage and organisms from the Vahlkampfiidae family were identified. The fungal 18S rRNA and tubulin gene sequences formed two distinct phylogenetic groups associated with the classes Dothideomycetes and Eurotiomycetes. Three fungal isolates that were closely related to the Dothideomycetes clones were obtained. We suggest the name “Acidomyces richmondensis” for these isolates. Since these ascomycete fungi were morphologically indistinguishable, rRNA-specific oligonucleotide probes were designed to target the Dothideomycetes and Eurotiomycetes via fluorescent in situ hybridization (FISH). FISH analyses indicated that Eurotiomycetes are generally more abundant than Dothideomycetes in all of the seven locations studied within the Richmond Mine system. This is the first study to combine the culture-independent detection of fungi with in situ detection and a demonstration of activity in an acidic environment. The results expand our understanding of the subsurface AMD microbial community structure. PMID:15466574

  2. Hydrogeochemical characteristics of streams with and without acid mine drainage impacts: A paired catchment study in karst geology, SW China

    NASA Astrophysics Data System (ADS)

    Sun, Jing; Tang, Changyuan; Wu, Pan; Strosnider, William H. J.; Han, Zhiwei

    2013-11-01

    A paired catchment study was used to assess karst hydrogeochemistry of two streams.Chemistry of streams with and without acid mine drainage (AMD) was very different.The observation was supported by PHREEQC modeling of equilibrium conditions.Ionic fluxes of AMD-impacted water were higher than that of non-AMD-impacted water.The higher ionic fluxes were predominantly controlled by the oxidation of pyrite.

  3. Copper isotope fractionation in acid mine drainage

    NASA Astrophysics Data System (ADS)

    Kimball, B. E.; Mathur, R.; Dohnalkova, A. C.; Wall, A. J.; Runkel, R. L.; Brantley, S. L.

    2009-03-01

    We measured the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed (Colorado, USA). The δ 65Cu values (based on 65Cu/ 63Cu) of enargite (δ 65Cu = -0.01 ± 0.10‰; 2 σ) and chalcopyrite (δ 65Cu = 0.16 ± 0.10‰) are within the range of reported values for terrestrial primary Cu sulfides (-1‰ < δ 65Cu < 1‰). These mineral samples show lower δ 65Cu values than stream waters (1.38‰ ⩽ δ 65Cu ⩽ 1.69‰). The average isotopic fractionation (Δ aq-min = δ 65Cu aq - δ 65Cu min, where the latter is measured on mineral samples from the field system), equals 1.43 ± 0.14‰ and 1.60 ± 0.14‰ for chalcopyrite and enargite, respectively. To interpret this field survey, we leached chalcopyrite and enargite in batch experiments and found that, as in the field, the leachate is enriched in 65Cu relative to chalcopyrite (1.37 ± 0.14‰) and enargite (0.98 ± 0.14‰) when microorganisms are absent. Leaching of minerals in the presence of Acidithiobacillus ferrooxidans results in smaller average fractionation in the opposite direction for chalcopyrite ( Δ=-0.57±0.14‰, where min o refers to the starting mineral) and no apparent fractionation for enargite ( Δ=0.14±0.14‰). Abiotic fractionation is attributed to preferential oxidation of 65Cu + at the interface of the isotopically homogeneous mineral and the surface oxidized layer, followed by solubilization. When microorganisms are present, the abiotic fractionation is most likely not seen due to preferential association of 65Cu aq with A. ferrooxidans cells and related precipitates. In the biotic experiments, Cu was observed under TEM to occur in precipitates around bacteria and in intracellular polyphosphate granules. Thus, the values of δ 65Cu in the field and laboratory systems are presumably determined by the balance of Cu released abiotically and Cu that interacts with cells and related precipitates. Such isotopic signatures

  4. Copper isotope fractionation in acid mine drainage

    USGS Publications Warehouse

    Kimball, B.E.; Mathur, R.; Dohnalkova, A.C.; Wall, A.J.; Runkel, R.L.; Brantley, S.L.

    2009-01-01

    We measured the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed (Colorado, USA). The ??65Cu values (based on 65Cu/63Cu) of enargite (??65Cu = -0.01 ?? 0.10???; 2??) and chalcopyrite (??65Cu = 0.16 ?? 0.10???) are within the range of reported values for terrestrial primary Cu sulfides (-1??? < ??65Cu < 1???). These mineral samples show lower ??65Cu values than stream waters (1.38??? ??? ??65Cu ??? 1.69???). The average isotopic fractionation (??aq-min = ??65Cuaq - ??65Cumin, where the latter is measured on mineral samples from the field system), equals 1.43 ?? 0.14??? and 1.60 ?? 0.14??? for chalcopyrite and enargite, respectively. To interpret this field survey, we leached chalcopyrite and enargite in batch experiments and found that, as in the field, the leachate is enriched in 65Cu relative to chalcopyrite (1.37 ?? 0.14???) and enargite (0.98 ?? 0.14???) when microorganisms are absent. Leaching of minerals in the presence of Acidithiobacillus ferrooxidans results in smaller average fractionation in the opposite direction for chalcopyrite (??aq-mino = - 0.57 ?? 0.14 ???, where mino refers to the starting mineral) and no apparent fractionation for enargite (??aq-mino = 0.14 ?? 0.14 ???). Abiotic fractionation is attributed to preferential oxidation of 65Cu+ at the interface of the isotopically homogeneous mineral and the surface oxidized layer, followed by solubilization. When microorganisms are present, the abiotic fractionation is most likely not seen due to preferential association of 65Cuaq with A. ferrooxidans cells and related precipitates. In the biotic experiments, Cu was observed under TEM to occur in precipitates around bacteria and in intracellular polyphosphate granules. Thus, the values of ??65Cu in the field and laboratory systems are presumably determined by the balance of Cu released abiotically and Cu that interacts with cells and related precipitates. Such isotopic signatures

  5. Sulfur dynamics in an impoundment receiving acid mine drainage

    SciTech Connect

    Herlihy, A.T.

    1987-01-01

    To quantify the importance of bacterial sulfate reduction (SR) in an acidified system, a sulfate influx-efflux budget was constructed for Lake Anna, an impoundment receiving acid mine drainage. Forty eight percent of the entering sulfate was removed from the water column within the 2 km arm of the lake that receives the pollution. Directly measured SR equaled 200% of the sulfate removal calculated in the budget. Thus, sulfide oxidation must be an important process in these sediments. The calculated alkalinity generated by sulfate removal was more than twice that necessary to account for the observed pH increase in the impoundment. Inorganic sulfur concentrations in the sediments of the impacted arm of Lake Anna were significantly greater than those in unpolluted sections of the lake. Label experiments showed that FeS and elemental sulfur (S{degree}) were the major products of SR in the impacted sediments. Inorganic sulfur (FeS, S{degree}, and pyrite) made up to 60% to 100% of the total sediment sulfur concentration. Pyrite concentrations were high and decreased exponentially with distance from the AMD source, indicating that the pyrite is stream detrius. FeS and S{degree} concentrations were highest at a station 1 km away from the AMD inflow, indicating in situ formation. There was no evidence for the formation of organic sulfur species.

  6. Copper isotope fractionation in acid mine drainage

    SciTech Connect

    Kimball, Bryn E; Mathur, Ryan; Dohnalkova, Alice; Wall, A J; Runkel, R L; Brantley, Susan L

    2009-03-01

    We surveyed the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed located in southwestern Colorado, USA. The δ65Cu values (based on 65Cu/63Cu) of local enargite (δ65Cu = -0.01 ± 0.10‰; 2σ) and chalcopyrite (δ65Cu = 0.16 ± 0.10‰) are within the general range of previously reported values for terrestrial primary Cu sulfides (-1‰ < δ65Cu < 1). These mineral samples show lower δ65Cu values than stream waters (δ65Cu = 1.36 - 1.74 ± 0.10‰), with an average isotopic fractionation (quantified as Δaq-mino = δ65Cuaq – δ65Cu min, where Cuaq is leached Cu and Cu mino is the original mineral) of 1.60 ± 0.14‰ and 1.43 ± 0.14‰ for enargite and chalcopyrite, respectively.

  7. FEASIBILITY OF ELK CREEK ACID MINE DRAINAGE ABATEMENT PROJECT

    EPA Science Inventory

    A study was conducted within the Elk Creek Watershed, West Virginia to determine the technical and economic feasibility of three acid mine drainage abatement techniques. Alkaline regarding and slurry trench construction were established as technically and economically viable abat...

  8. Integrated acid mine drainage management using fly ash.

    PubMed

    Vadapalli, Viswanath R K; Gitari, Mugera W; Petrik, Leslie F; Etchebers, Olivier; Ellendt, Annabelle

    2012-01-01

    Fly Ash (FA) from a power station in South Africa was investigated to neutralise and remove contaminants from Acid Mine Drainage (AMD). After this primary treatment the insoluble FA residue namely solid residue (SR) was investigated as a suitable mine backfill material by means of strength testing. Moreover, SR was used to synthesise zeolite-P using a two-step synthesis procedure. Furthermore, the zeolite-P was investigated to polish process water from the primary FA-AMD reaction. The main objective of this series of investigations is to achieve zero waste and to propose an integrated AMD management using FA. Fly Ash was mixed with AMD at various predetermined FA-AMD ratios until the mixtures achieved circumneutral pH or higher. The supernatants were then analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Ion Chromatography (IC) for cations and anions respectively. The physical strength testing of SR was carried out by mixing it with 3% Ordinary Portland Cement (OPC) and curing for 410 days. Synthesis of zeolite-P using SR was carried out by two step synthesis procedure: ageing for 24 hours followed by a mild hydrothermal synthesis at 100°C for 4 days. The polishing of process water from primary AMD treatment using FA was ascertained by mixing the process water with zeolite at a liquid to solid ratio of 100:1 for 1 hour. The results indicated that FA can be successfully used to ameliorate AMD. High removal of major AMD contaminants Fe, Al, Mg, Mn and sulphate was achieved with the ash treatment and trace elements such as Zn, Ni, Cu and Pb were also removed by the FA. Strength testing over 410 days indicated that the material gained strength over the testing period. The maximum unconfined compressive strength and elastic modulus was observed to be approximately 0.3 MPa and 150 Mpa respectively. The X-ray diffraction (XRD) analysis of the synthesized product indicated that SR was successfully converted into zeolite-P with some mullite phase

  9. Acid mine drainage biogeochemistry at Iron Mountain, California

    PubMed Central

    Druschel, Gregory K; Baker, Brett J; Gihring, Thomas M; Banfield, Jillian F

    2004-01-01

    The Richmond Mine at Iron Mountain, Shasta County, California, USA provides an excellent opportunity to study the chemical and biological controls on acid mine drainage (AMD) generation in situ, and to identify key factors controlling solution chemistry. Here we integrate four years of field-based geochemical data with 16S rRNA gene clone libraries and rRNA probe-based studies of microbial population structure, cultivation-based metabolic experiments, arsenopyrite surface colonization experiments, and results of intermediate sulfur species kinetics experiments to describe the Richmond Mine AMD system. Extremely acidic effluent (pH between 0.5 and 0.9) resulting from oxidation of approximately 1 × 105 to 2 × 105 moles pyrite/day contains up to 24 g/1 Fe, several g/1 Zn and hundreds of mg/l Cu. Geochemical conditions change markedly over time, and are reflected in changes in microbial populations. Molecular analyses of 232 small subunit ribosomal RNA (16S rRNA) gene sequences from six sites during a sampling time when lower temperature (<32°C), higher pH (>0.8) conditions predominated show the dominance of Fe-oxidizing prokaryotes such as Ferroplasma and Leptospirillum in the primary drainage communities. Leptospirillum group III accounts for the majority of Leptospirillum sequences, which we attribute to anomalous physical and geochemical regimes at that time. A couple of sites peripheral to the main drainage, "Red Pool" and a pyrite "Slump," were even higher in pH (>1) and the community compositions reflected this change in geochemical conditions. Several novel lineages were identified within the archaeal Thermoplasmatales order associated with the pyrite slump, and the Red Pool (pH 1.4) contained the only population of Acidithiobacillus. Relatively small populations of Sulfobacillus spp. and Acidithiobacillus caldus may metabolize elemental sulfur as an intermediate species in the oxidation of pyritic sulfide to sulfate. Experiments show that elemental sulfur

  10. Treatment of acid mine drainage with fly ash: Removal of major contaminants and trace elements

    SciTech Connect

    Gitari, M.W.; Petrik, L.F.; Etchebers, O.; Key, D.L.; Iwuoha, E.; Okujeni, C.

    2006-08-15

    Acid mine drainage (AMD) has been reacted with two South African fly ashes in a batch setup in an attempt to evaluate their neutralization and major, trace elements removal capacity. Different fly ash:acid mine drainage ratios (FA:AMD) were stirred in a beaker for a set time and the process water analyzed for major, trace elements and sulphate content. The three factors that finally dictated the nature of the final solution in these neutralization reactions were the FA:AMD ratio, the contact time of the reaction and the chemistry of the AMD. Efficiency of the elements removal was directly linked to the amount of FA in the reaction mixture and to the final pH attained. Most elements attained approximate to 100% removal only when the pH of minimum solubility of their hydroxides was achieved (i.e., Mg = 10.49 - 11.0, Cu{sup 2+} = 6, Pb{sup 2+} = 6 - 7). Dissolution of CaO and subsequent precipitation of gypsum and formation of Al, Fe oxyhydroxysulphates, Fe oxyhydroxides with subsequent adsorption of sulphate contributed to the sulphate attenuation. Significant leaching of B, Sr, Ba and Mo was observed as the reaction progressed and was observed to increase with quantity of fly ash in the reaction mixture. However B was observed to decrease at high FA:AMD ratios probably as result of co-precipitation with CaCO{sub 3}(s).

  11. Inter-species interconnections in acid mine drainage microbial communities

    PubMed Central

    Comolli, Luis R.; Banfield, Jill F.

    2014-01-01

    Metagenomic studies are revolutionizing our understanding of microbes in the biosphere. They have uncovered numerous proteins of unknown function in tens of essentially unstudied lineages that lack cultivated representatives. Notably, few of these microorganisms have been visualized, and even fewer have been described ultra-structurally in their essentially intact, physiologically relevant states. Here, we present cryogenic transmission electron microscope (cryo-TEM) 2D images and 3D tomographic datasets for archaeal species from natural acid mine drainage (AMD) microbial communities. Ultrastructural findings indicate the importance of microbial interconnectedness via a range of mechanisms, including direct cytoplasmic bridges and pervasive pili. The data also suggest a variety of biological structures associated with cell-cell interfaces that lack explanation. Some may play roles in inter-species interactions. Interdependences amongst the archaea may have confounded prior isolation efforts. Overall, the findings underline knowledge gaps related to archaeal cell components and highlight the likely importance of co-evolution in shaping microbial lineages. PMID:25120533

  12. Major hydrogeochemical processes in an acid mine drainage affected estuary.

    PubMed

    Asta, Maria P; Calleja, Maria Ll; Pérez-López, Rafael; Auqué, Luis F

    2015-02-15

    This study provides geochemical data with the aim of identifying and quantifying the main processes occurring in an Acid Mine Drainage (AMD) affected estuary. With that purpose, water samples of the Huelva estuary were collected during a tidal half-cycle and ion-ion plots and geochemical modeling were performed to obtain a general conceptual model. Modeling results indicated that the main processes responsible for the hydrochemical evolution of the waters are: (i) the mixing of acid fluvial water with alkaline ocean water; (ii) precipitation of Fe oxyhydroxysulfates (schwertmannite) and hydroxides (ferrihydrite); (iii) precipitation of Al hydroxysulfates (jurbanite) and hydroxides (amorphous Al(OH)3); (iv) dissolution of calcite; and (v) dissolution of gypsum. All these processes, thermodynamically feasible in the light of their calculated saturation states, were quantified by mass-balance calculations and validated by reaction-path calculations. In addition, sorption processes were deduced by the non-conservative behavior of some elements (e.g., Cu and Zn). PMID:25530015

  13. Potential of fly ash for neutralisation of acid mine drainage.

    PubMed

    Qureshi, Asif; Jia, Yu; Maurice, Christian; Öhlander, Björn

    2016-09-01

    Lignite (PK), bituminous (FI) and biomass (SE) fly ashes (FAs) were mineralogically and geochemically characterised, and their element leachability was studied with batch leaching tests. The potential for acid neutralisation (ANP) was quantified by their buffering capacity, reflecting their potential for neutralisation of acid mine drainage. Quartz was the common mineral in FAs detected by XRD with iron oxide, anhydrite, and magnesioferrite in PK, mullite and lime in FI, and calcite and anorthite in SE. All the FAs had high contents of major elements such as Fe, Si, Al and Ca. The Ca content in SE was six and eight times higher compared to PK and FI, respectively. Sulphur content in PK and SE was one magnitude higher than FI. Iron concentrations were higher in PK. The trace element concentrations varied between the FAs. SE had the highest ANP (corresponding to 275 kg CaCO3 tonne(-1)) which was 15 and 10 times higher than PK and FI, respectively. The concentrations of Ca(2+), SO4 (2-), Na(+) and Cl(-) in the leachates were much higher compared to other elements from all FA samples. Iron, Cu and Hg were not detected in any of the FA leachates because of their mild to strong alkaline nature with pH ranging from 9 to 13. Potassium leached in much higher quantity from SE than from the other ashes. Arsenic, Mn and Ni leached from PK only, while Co and Pb from SE only. The concentrations of Zn were higher in the leachates from SE. The FAs used in this study have strong potential for the neutralisation of AMD due to their alkaline nature. However, on the other hand, FAs must be further investigated, with scaled-up experiments before full-scale application, because they might leach pronounced concentrations of elements of concern with decreasing pH while neutralising AMD. PMID:27209637

  14. Recovery of Rare Earth Elements and Yttrium from Passive-Remediation Systems of Acid Mine Drainage.

    PubMed

    Ayora, Carlos; Macías, Francisco; Torres, Ester; Lozano, Alba; Carrero, Sergio; Nieto, José-Miguel; Pérez-López, Rafael; Fernández-Martínez, Alejandro; Castillo-Michel, Hiram

    2016-08-01

    Rare earth elements and yttrium (REY) are raw materials of increasing importance for modern technologies, and finding new sources has become a pressing need. Acid mine drainage (AMD) is commonly considered an environmental pollution issue. However, REY concentrations in AMD can be several orders of magnitude higher than in naturally occurring water bodies. With respect to shale standards, the REY distribution pattern in AMD is enriched in intermediate and valuable REY, such as Tb and Dy. The objective of the present work is to study the behavior of REY in AMD passive-remediation systems. Traditional AMD passive remediation systems are based on the reaction of AMD with calcite-based permeable substrates followed by decantation ponds. Experiments with two columns simulating AMD treatment demonstrate that schwertmannite does not accumulate REY, which, instead, are retained in the basaluminite residue. The same observation is made in two field-scale treatments from the Iberian Pyrite Belt (IPB, southwest Spain). On the basis of the amplitude of this process and on the extent of the IPB, our findings suggest that the proposed AMD remediation process can represent a modest but suitable REY source. In this sense, the IPB could function as a giant heap-leaching process of regional scale in which rain and oxygen act as natural driving forces with no energy investment. In addition to having environmental benefits of its treatment, AMD is expected to last for hundreds of years, and therefore, the total reserves are practically unlimited. PMID:27351211

  15. LIMESTONE AND LIME NEUTRALIZATION OF FERROUS IRON ACID MINE DRAINAGE

    EPA Science Inventory

    The U.S. Environmental Protection Agency conducted a 2-yr study on hydrated lime and rock-dust limestone neutralization of acid mine drainage containing ferrous iron at the EPA Crown Mine Drainage Control Field Site near Rivesville, West Virginia. The study investigated optimizat...

  16. BIORECOVERY OF METALS FROM ACID MINE DRAINAGE

    EPA Science Inventory

    Acid mine water is an acidic, metal-bearing wastewater generated by the oxidation of metallic sulfides by certain bacteria in both active and abandoned mining operations. The wastewaters contain substantial quantities of dissolved solids with the particular pollutants dependant u...

  17. Penn State researches acid mine drainage

    SciTech Connect

    Not Available

    1984-08-27

    A brief news item reports that work is being carried out at Penn State University on the effectiveness of sphagnum moss and other marsh-type plants in removing iron from acid mine water. A sphagnum moss bog has been established in a greenhouse at the University and field work is also being undertaken in a natural environment in Clearfield County.

  18. Sulfate reduction at low pH to remediate acid mine drainage.

    PubMed

    Sánchez-Andrea, Irene; Sanz, Jose Luis; Bijmans, Martijn F M; Stams, Alfons J M

    2014-03-30

    Industrial activities and the natural oxidation of metallic sulfide-ores produce sulfate-rich waters with low pH and high heavy metals content, generally termed acid mine drainage (AMD). This is of great environmental concern as some heavy metals are highly toxic. Within a number of possibilities, biological treatment applying sulfate-reducing bacteria (SRB) is an attractive option to treat AMD and to recover metals. The process produces alkalinity, neutralizing the AMD simultaneously. The sulfide that is produced reacts with the metal in solution and precipitates them as metal sulfides. Here, important factors for biotechnological application of SRB such as the inocula, the pH of the process, the substrates and the reactor design are discussed. Microbial communities of sulfidogenic reactors treating AMD which comprise fermentative-, acetogenic- and SRB as well as methanogenic archaea are reviewed. PMID:24444599

  19. Roles of Benthic Algae in the Structure, Function, and Assessment of Stream Ecosystems Affected by Acid Mine Drainage

    EPA Science Inventory

    Tens of thousands of stream kilometers around the world are degraded by a legacy of environmental impacts and acid mine drainage (AMD) caused by abandoned underground and surface mines, piles of discarded coal wastes, and tailings. Increased acidity, high concentrations of metals...

  20. Acid mine drainage and subsidence: effects of increased coal utilization.

    PubMed Central

    Hill, R D; Bates, E R

    1979-01-01

    The increases above 1975 levels for acid mine drainage and subsidence for the years 1985 and 2000 based on projections of current mining trends and the National Energy Plan are presented. No increases are projected for acid mine drainage from surface mines or waste since enforcement under present laws should control this problem. The increase in acid mine drainage from underground mines is projected to be 16 percent by 1985 and 10 percent by 2000. The smaller increase in 2000 over 1985 reflects the impact of the PL 95-87 abandoned mine program. Mine subsidence is projected to increase by 34 and 115 percent respectively for 1985 and 2000. This estimate assumes that subsidence will parallel the rate of underground coal production and that no new subsidence control measures are adopted to mitigate subsidence occurrence. PMID:540617

  1. Synthesising acid mine drainage to maintain and exploit indigenous mining micro-algae and microbial assemblies for biotreatment investigations.

    PubMed

    Orandi, Sanaz; Lewis, David M

    2013-02-01

    The stringent regulations for discharging acid mine drainage (AMD) has led to increased attention on traditional or emerging treatment technologies to establish efficient and sustainable management for mine effluents. To assess new technologies, laboratory investigations on AMD treatment are necessary requiring a consistent supply of AMD with a stable composition, thus limiting environmental variability and uncertainty during controlled experiments. Additionally, biotreatment systems using live cells, particularly micro-algae, require appropriate nutrient availability. Synthetic AMD (Syn-AMD) meets these requirements. However, to date, most of the reported Syn-AMDs are composed of only a few selected heavy metals without considering the complexity of actual AMD. In this study, AMD was synthesised based on the typical AMD characteristics from a copper mine where biotreatment is being considered using indigenous AMD algal-microbes. Major cations (Ca, Na, Cu, Zn, Mg, Mn and Ni), trace metals (Al, Fe, Ag, Na, Co, Mo, Pb and Cr), essential nutrients (N, P and C) and high SO(4) were incorporated into the Syn-AMD. This paper presents the preparation of chemically complex Syn-AMD and the challenges associated with combining metal salts of varying solubility that is not restricted to one particular mine site. The general approach reported and the particular reagents used can produce alternative Syn-AMD with varying compositions. The successful growth of indigenous AMD algal-microbes in the Syn-AMD demonstrated its applicability as appropriate generic media for cultivation and maintenance of mining microorganisms for future biotreatment studies. PMID:22684898

  2. Humic substances increase survival of freshwater shrimp Caridina sp. D to acid mine drainage.

    PubMed

    Holland, Aleicia; Duivenvoorden, Leo J; Kinnear, Susan H W

    2013-02-01

    Humic substances (HS) are known to decrease the toxicity of heavy metals to aquatic organisms, and it has been suggested that they can provide buffering protection in low pH conditions. Despite this, little is known about the ability for HS to increase survival to acid mine drainage (AMD). In this study, the ability of HS to increase survival of the freshwater shrimp (Caridina sp. D sensu Page et al. in Biol Lett 1:139-142, 2005) to acid mine drainage was investigated using test waters collected from the Mount Morgan open pit in Central Queensland with the addition of Aldrich humic acid (AHA). The AMD water from the Mount Morgan open pit is highly acidic (pH 2.67) as well as contaminated with heavy metals (1780 mg/L aluminum, 101 mg/L copper [Cu], 173 mg/L manganese, 51.8 mg/L zinc [Zn], and 51.8 mg/L iron). Freshwater shrimp were exposed to dilutions in the range of 0.5 % to 5 % AMD water with and without the addition of 10 or 20 mg/L AHA. In the absence of HS, all shrimp died in the 2.5 % AMD treatment. In contrast, addition of HS increased survival in the 2.5 % AMD treatment by ≤66 % as well as significantly decreased the concentration of dissolved Cu, cobalt, cadmium, and Zn. The decreased toxicity of AMD in the presence of HS is likely to be due to complexation and precipitation of heavy metals with the HS; it is also possible that HS caused changes to the physiological condition of the shrimp, thus increasing their survival. These results are valuable in contributing to an improved understanding of potential role of HS in ameliorating the toxicity of AMD environments. PMID:23135152

  3. Co-treatment of acid mine drainage with municipal wastewater: performance evaluation.

    PubMed

    Hughes, Theresa A; Gray, Nicholas F

    2013-11-01

    Co-treatment of acid mine drainage (AMD) with municipal wastewater (MWW) using the activated sludge process is a novel treatment technology offering potential savings over alternative systems in materials, proprietary chemicals and energy inputs. The impacts of AMD on laboratory-scale activated sludge units (plug-flow and sequencing batch reactors) treating synthetic MWW were investigated. Synthetic AMD containing Al, Cu, Fe, Mn, Pb, Zn and SO4 at a range of concentrations and pH values was formulated to simulate three possible co-treatment processes, i.e., (1) adding raw AMD to the activated sludge aeration tank, (2) pre-treating AMD prior to adding to the aeration tank by mixing with digested sludge and (3) pre-treating AMD by mixing with screened MWW. Continuous AMD loading to the activated sludge reactors during co-treatment did not cause a significant decrease in chemical oxygen demand (COD), 5-day biochemical oxygen demand, or total organic carbon removal; average COD removal rates ranged from 87-93%. Enhanced phosphate removal was observed in reactors loaded with Fe- and Al-rich AMD, with final effluent TP concentrations<2 mg/L. Removal rates for dissolved Al, Cu, Fe and Pb were 52-84%, 47-61%, 74-86% and 100%, respectively, in both systems. Manganese and Zn removal were strongly linked to acidity; removal from net-acidic AMD was <10% for both metals, whereas removal from circum-neutral AMD averaged 93-95% for Mn and 58-90% for Zn. Pre-mixing with screened MWW was the best process option in terms of AMD neutralization and metal removal. However, significant MWW alkalinity was consumed, suggesting an alkali supplement may be necessary. PMID:23161500

  4. RECOVERY OF METALS FROM ACID MINE DRAINAGE: JOURNAL ARTICLE

    EPA Science Inventory

    NRMRL-CIN-1349A Scharp*, R.A., Kawahara*, F.K., Burckle, J.O., Allen J., and Govind, R. "Recovery of Metals from Acid Mine Drainage." In: Bioremediation of Inorganic Compounds, In Situ and On-Site Bioremediation Sixth International Symposium, San Diego, CA, 6/4-7/2001. Andrea Le...

  5. REMOVAL OF TRACE ELEMENTS FROM ACID MINE DRAINAGE

    EPA Science Inventory

    Lime neutralization, reverse osmosis, and ion exchange were studied for their effectiveness in removing mg/l levels of ten specific trace elements from spiked acid mine drainage under typical operating conditions. The specified toxic materials were arsenic, boron, cadmium, chromi...

  6. HANDBOOK FOR CONSTRUCTED WETLANDS RECEIVING ACID MINE DRAINAGE

    EPA Science Inventory

    In the summer of 1987, a pilot constructed wetland was built at the Big Five Tunnel in Idaho Springs, Colorado. This report details the theory, design and construction of wetlands receiving acid mine drainages, based on the second and third year of operation of this wetland, whic...

  7. HANDBOOK FOR CONSTRUCTED WETLANDS RECEIVING ACID MINE DRAINAGE

    EPA Science Inventory

    In the summer of 1987, a pilot constructed wetland was built at the Big Five Tunnel in Idaho Springs, Colorado. his report details the theory, design and construction of wetlands receiving acid mine drainages, based on the second and third year of operation of this wetland, which...

  8. Activated sludge as substrate for sulfate-reducing bacteria in acid mine drainage treatment

    SciTech Connect

    Al-Ani, W.A.G.; Henry, J.G.; Prasad, D.

    1996-11-01

    Acid mine drainage (AMD), characterized by high concentrations of sulfates and heavy metals and low pH, presents a potential hazard to the environment.Several treatment processes (chemical precipitation, ion exchange, reverse osmosis, electrodialysis and electrolytic recovery) are available, but these are often too expensive. Biological treatment of AMD, mediated by sulfate-reducing bacteria (SRB), seems promising. The objective of this study was to use activated sludge as a carbon source for the SRB and determine the most effective COD/sulfate ratio and hydraulic retention time (HRT) for reducing sulfate. Such information would be useful for the application of the proposed two-stage system to AMD treatment. Since the aim of this study was to obtain sulfate reduction and to avoid methane production, it was decided to operate the digesters initially at low COD/SO{sub 4}{sup 2{minus}} ratios of 1.0, 1.5, and 2.0.

  9. Microbial Ecology and Evolution in the Acid Mine Drainage Model System.

    PubMed

    Huang, Li-Nan; Kuang, Jia-Liang; Shu, Wen-Sheng

    2016-07-01

    Acid mine drainage (AMD) is a unique ecological niche for acid- and toxic-metals-adapted microorganisms. These low-complexity systems offer a special opportunity for the ecological and evolutionary analyses of natural microbial assemblages. The last decade has witnessed an unprecedented interest in the study of AMD communities using 16S rRNA high-throughput sequencing and community genomic and postgenomic methodologies, significantly advancing our understanding of microbial diversity, community function, and evolution in acidic environments. This review describes new data on AMD microbial ecology and evolution, especially dynamics of microbial diversity, community functions, and population genomes, and further identifies gaps in our current knowledge that future research, with integrated applications of meta-omics technologies, will fill. PMID:27050827

  10. A Novel Treatment for Acid Mine Drainage Utilizing Reclaimed Limestone Residual

    SciTech Connect

    Horace K. Moo-Young; Charles E. Ochola

    2004-08-31

    The viability of utilizing Reclaimed Limestone Residual (RLR) to remediate Acid Mine Drainage (AMD) was investigated. Physical and chemical characterization of RLR showed that it is composed of various minerals that contain significant quantities of limestone or calcium bearing compounds that can be exploited for acid neutralization. Acid Neutralization Potential (ANP) test results showed that RLR has a neutralization potential of approximately 83% as calcium carbonate (CaCO{sub 3}). Neutralization tests with most of the heavy metals associated with AMD showed removal efficiencies of over 99%. An unexpected benefit of utilizing RLR was the removal of hexavalent chromium Cr (VI) from the aqueous phase. Due to an elevation in pH by RLR most AMD heavy metals are removed from solution by precipitation as their metal hydroxides. Cr (VI) however is not removed by pH elevation and therefore subsequent ongoing tests to elucidate the mechanism responsible for this reaction were conducted.

  11. Heavy metal removal from acid mine drainage by calcined eggshell and microalgae hybrid system.

    PubMed

    Choi, Hee-Jeong; Lee, Seung-Mok

    2015-09-01

    This study investigates the use of calcined eggshells and microalgae for the removal of heavy metals from acid mine drainage (AMD) and the simultaneous enhancement of biomass productivity. The experiment was conducted over a period of 6 days in a hybrid system containing calcined eggshells and the microalgae Chlorella vulgaris. The results show that the biomass productivity increased to ~8.04 times its initial concentration of 0.367 g/L as measured by an optical panel photobioreactor (OPPBR) and had a light transmittance of 95 % at a depth of 305 mm. On the other hand, the simultaneous percent removal of Fe, Cu, Zn, Mn, As, and Cd from the AMD effluent was found to be 99.47 to 100 %. These results indicate that the hybrid system with calcined eggshells and microalgae was highly effective for heavy metal removal in the AMD. PMID:25940497

  12. Current approaches for mitigating acid mine drainage.

    PubMed

    Sahoo, Prafulla Kumar; Kim, Kangjoo; Equeenuddin, Sk Md; Powell, Michael A

    2013-01-01

    AMD is one of the critical environmental problems that causes acidification and metal contamination of surface and ground water bodies when mine materials and/or over burden-containing metal sulfides are exposed to oxidizing conditions. The best option to limit AMD is early avoidance of sulfide oxidation. Several techniques are available to achieve this. In this paper, we review all of the major methods now used to limit sulfide oxidation. These fall into five categories: (1) physical barriers,(2) bacterial inhibition, (3) chemical passivation, ( 4) electrochemical, and (5) desulfurization.We describe the processes underlying each method by category and then address aspects relating to effectiveness, cost, and environmental impact. This paper may help researchers and environmental engineers to select suitable methods for addressing site-specific AMD problems.Irrespective of the mechanism by which each method works, all share one common feature, i.e., they delay or prevent oxidation. In addition, all have limitations.Physical barriers such as wet or dry cover have retarded sulfide oxidation in several studies; however, both wet and dry barriers exhibit only short-term effectiveness.Wet cover is suitable at specific sites where complete inundation is established, but this approach requires high maintenance costs. When employing dry cover, plastic liners are expensive and rarely used for large volumes of waste. Bactericides can suppress oxidation, but are only effective on fresh tailings and short-lived, and do not serve as a permanent solution to AMD. In addition, application of bactericides may be toxic to aquatic organisms.Encapsulation or passivation of sulfide surfaces (applying organic and/or inorganic coatings) is simple and effective in preventing AMD. Among inorganic coatings,silica is the most promising, stable, acid-resistant and long lasting, as compared to phosphate and other inorganic coatings. Permanganate passivation is also promising because it

  13. Identification of Nitrogen-Fixing Genes and Gene Clusters from Metagenomic Library of Acid Mine Drainage

    PubMed Central

    Yin, Huaqun; Liang, Yili; Cong, Jing; Liu, Xueduan

    2014-01-01

    Biological nitrogen fixation is an essential function of acid mine drainage (AMD) microbial communities. However, most acidophiles in AMD environments are uncultured microorganisms and little is known about the diversity of nitrogen-fixing genes and structure of nif gene cluster in AMD microbial communities. In this study, we used metagenomic sequencing to isolate nif genes in the AMD microbial community from Dexing Copper Mine, China. Meanwhile, a metagenome microarray containing 7,776 large-insertion fosmids was constructed to screen novel nif gene clusters. Metagenomic analyses revealed that 742 sequences were identified as nif genes including structural subunit genes nifH, nifD, nifK and various additional genes. The AMD community is massively dominated by the genus Acidithiobacillus. However, the phylogenetic diversity of nitrogen-fixing microorganisms is much higher than previously thought in the AMD community. Furthermore, a 32.5-kb genomic sequence harboring nif, fix and associated genes was screened by metagenome microarray. Comparative genome analysis indicated that most nif genes in this cluster are most similar to those of Herbaspirillum seropedicae, but the organization of the nif gene cluster had significant differences from H. seropedicae. Sequence analysis and reverse transcription PCR also suggested that distinct transcription units of nif genes exist in this gene cluster. nifQ gene falls into the same transcription unit with fixABCX genes, which have not been reported in other diazotrophs before. All of these results indicated that more novel diazotrophs survive in the AMD community. PMID:24498417

  14. Comparative metagenomic and metatranscriptomic analyses of microbial communities in acid mine drainage.

    PubMed

    Chen, Lin-xing; Hu, Min; Huang, Li-nan; Hua, Zheng-shuang; Kuang, Jia-liang; Li, Sheng-jin; Shu, Wen-sheng

    2015-07-01

    The microbial communities in acid mine drainage have been extensively studied to reveal their roles in acid generation and adaption to this environment. Lacking, however, are integrated community- and organism-wide comparative gene transcriptional analyses that could reveal the response and adaptation mechanisms of these extraordinary microorganisms to different environmental conditions. In this study, comparative metagenomics and metatranscriptomics were performed on microbial assemblages collected from four geochemically distinct acid mine drainage (AMD) sites. Taxonomic analysis uncovered unexpectedly high microbial biodiversity of these extremely acidophilic communities, and the abundant taxa of Acidithiobacillus, Leptospirillum and Acidiphilium exhibited high transcriptional activities. Community-wide comparative analyses clearly showed that the AMD microorganisms adapted to the different environmental conditions via regulating the expression of genes involved in multiple in situ functional activities, including low-pH adaptation, carbon, nitrogen and phosphate assimilation, energy generation, environmental stress resistance, and other functions. Organism-wide comparative analyses of the active taxa revealed environment-dependent gene transcriptional profiles, especially the distinct strategies used by Acidithiobacillus ferrivorans and Leptospirillum ferrodiazotrophum in nutrients assimilation and energy generation for survival under different conditions. Overall, these findings demonstrate that the gene transcriptional profiles of AMD microorganisms are closely related to the site physiochemical characteristics, providing clues into the microbial response and adaptation mechanisms in the oligotrophic, extremely acidic environments. PMID:25535937

  15. CCB-based encapsulation of pyrite for remediation of acid mine drainage.

    PubMed

    Bulusu, Sowmya; Aydilek, Ahmet H; Rustagi, Neha

    2007-05-17

    Acid mine drainage (AMD) from abandoned coal mines continues to be one of the most significant environmental problems. Remediation of AMD requires an addition of lime source to decrease the acidity, and grouting the entire mine and encapsulating the pyrite by calcium-rich additives is often employed. Utilization of alkaline coal combustion by-products (CCBs) has gained acceptance in such remediation applications because of their cost-effectiveness. A study was conducted to investigate the effectiveness of CCBs to abate acid mine drainage by encapsulation of pyrite. Geomechanical, hydraulic, and environmental tests were performed on grouts prepared with various ratios of CCBs as well as an alternative free lime source, lime kiln dust (LKD). The results indicated that the mechanical properties of grouts were dependent on their free lime contents. Hydraulic conductivities of pyrite-grout columns were relatively high due to the coating of the pyrite rock with the grout rather than the filling of all of the void spaces, as commonly experienced in field applications. The leaching tests indicated that the presence of high amounts of lime in a grout is not solely sufficient to improve the quality of AMD, since the rate of dissolution of a high lime content grout may be slow due to its rapid hardening. Therefore, it is recommended that grouts be selected with consideration of their hardening capacities, as well as the percentage of lime content present in the mixture. PMID:17303328

  16. Comparative metagenomic and metatranscriptomic analyses of microbial communities in acid mine drainage

    PubMed Central

    Chen, Lin-xing; Hu, Min; Huang, Li-nan; Hua, Zheng-shuang; Kuang, Jia-liang; Li, Sheng-jin; Shu, Wen-sheng

    2015-01-01

    The microbial communities in acid mine drainage have been extensively studied to reveal their roles in acid generation and adaption to this environment. Lacking, however, are integrated community- and organism-wide comparative gene transcriptional analyses that could reveal the response and adaptation mechanisms of these extraordinary microorganisms to different environmental conditions. In this study, comparative metagenomics and metatranscriptomics were performed on microbial assemblages collected from four geochemically distinct acid mine drainage (AMD) sites. Taxonomic analysis uncovered unexpectedly high microbial biodiversity of these extremely acidophilic communities, and the abundant taxa of Acidithiobacillus, Leptospirillum and Acidiphilium exhibited high transcriptional activities. Community-wide comparative analyses clearly showed that the AMD microorganisms adapted to the different environmental conditions via regulating the expression of genes involved in multiple in situ functional activities, including low-pH adaptation, carbon, nitrogen and phosphate assimilation, energy generation, environmental stress resistance, and other functions. Organism-wide comparative analyses of the active taxa revealed environment-dependent gene transcriptional profiles, especially the distinct strategies used by Acidithiobacillus ferrivorans and Leptospirillum ferrodiazotrophum in nutrients assimilation and energy generation for survival under different conditions. Overall, these findings demonstrate that the gene transcriptional profiles of AMD microorganisms are closely related to the site physiochemical characteristics, providing clues into the microbial response and adaptation mechanisms in the oligotrophic, extremely acidic environments. PMID:25535937

  17. DESIGN MANUAL: NEUTRALIZATION OF ACID MINE DRAINAGE

    EPA Science Inventory

    This manual was prepared to assist designers and operators of mine drainage treatment plants in the selection of processes, equipment, and procedures. Included is a review of the most popular neutralizing agents and the methods used to handle, prepare, and feed these alkalies. Al...

  18. Microbiological monitoring of acid mine drainage treatment systems and aquatic surroundings using real-time PCR.

    PubMed

    Han, J S; Kim, C G

    2009-01-01

    In general, acid mine drainage (AMD) causes low pH and high metal concentrations in mining areas and surroundings. The aim of this research was to achieve microbiological monitoring for AMD and to assess whether mine water outflows have any ecological effects on the aqueous ecosystem receiving effluents from different types of treatment system. The water quality of aquatic sample was analyzed and the molecular biological diversity of the samples was assessed using 16S rRNA methods, which were implemented to determine which bacteria existed throughout various unit processes for different AMD treatment systems and their receiving water environments. Acidiphilium cryptum, a heterotrophic acidophile, was found at the AMD sites, and Rhodoferax ferrireducens, which can reduce iron using insoluble Fe(III) as an electron acceptor, was detected at many AMD treatment facilities and downstream of the treatment processes. Subsequently, quantitative real-time PCR was conducted on specific genes of selected bacteria. Surprisingly, obvious trends were observed in the relative abundance of the various bacteria that corresponded to the water quality analytical results. The copy number of Desulfosporosinus orientus, a sulfate reducing bacteria, was also observed to decrease in response to decreases in metals according to the downstream flow of the AMD treatment system. PMID:19494446

  19. Bioreactor for acid mine drainage control

    DOEpatents

    Zaluski, Marek H.; Manchester, Kenneth R.

    2001-01-01

    A bioreactor for reacting an aqueous heavy metal and sulfate containing mine drainage solution with sulfate reducing bacteria to produce heavy metal sulfides and reduce the sulfuric acid content of the solution. The reactor is an elongated, horizontal trough defining an inlet section and a reaction section. An inlet manifold adjacent the inlet section distributes aqueous mine drainage solution into the inlet section for flow through the inlet section and reaction section. A sulfate reducing bacteria and bacteria nutrient composition in the inlet section provides sulfate reducing bacteria that with the sulfuric acid and heavy metals in the solution to form solid metal sulfides. The sulfate reducing bacteria and bacteria nutrient composition is retained in the cells of a honeycomb structure formed of cellular honeycomb panels mounted in the reactor inlet section. The honeycomb panels extend upwardly in the inlet section at an acute angle with respect to the horizontal. The cells defined in each panel are thereby offset with respect to the honeycomb cells in each adjacent panel in order to define a tortuous path for the flow of the aqueous solution.

  20. The control of acid mine drainage at the Summitville Mine Superfund Site

    SciTech Connect

    Ketellapper, V.L.; Williams, L.O.

    1996-11-01

    The Summitville Mine Superfund Site is located about 25 miles south of Del Norte, Colorado, in Rio Grande County. Occurring at an average elevation of 11,500 feet in the San Juan Mountain Range, the mine site is located two miles east of the Continental Divide. Mining at Summitville has occurred since 1870. The mine was most recently operated by Summitville Consolidated Mining Company, Inc. (SCMCI) as an open pit gold mine with extraction by means of a cyanide leaching process. In December of 1992, SCMCI declared bankruptcy and vacated the mine site. At that time, the US Environmental Protection Agency (EPA) took over operations of the water treatment facilities to prevent a catastrophic release of cyanide and metal-laden water from the mine site. Due to high operational costs of water treatment (approximately $50,000 per day), EPA established a goal to minimize active water treatment by reducing or eliminating acid mine drainage (AMD). All of the sources of AMD generation on the mine site were evaluated and prioritized. Of the twelve areas identified as sources of AMD, the Cropsy Waste Pile, the Summitville Dam Impoundment, the Beaver Mud Dump, the Reynolds and Chandler adits, and the Mine Pits were consider to be the most significant contributors to the generation of metal-laden acidic (low pH) water. A two part plan was developed to control AMD from the most significant sources. The first part was initiated immediately to control AMD being released from the Site. This part focused on improving the efficiency of the water treatment facilities and controlling the AMD discharges from the mine drainage adits. The second part of the plan was aimed at reducing the AMD generated in groundwater and surface water runoff from the mine wastes. A lined and capped repository located in the mine pits for acid generating mining waste and water treatment plant sludge was found to be the most feasible alternative.

  1. Applications of multi-season hyperspectral remote sensing for acid mine water characterization and mapping of secondary iron minerals associated with acid mine drainage

    NASA Astrophysics Data System (ADS)

    Davies, Gwendolyn E.

    Acid mine drainage (AMD) resulting from the oxidation of sulfides in mine waste is a major environmental issue facing the mining industry today. Open pit mines, tailings ponds, ore stockpiles, and waste rock dumps can all be significant sources of pollution, primarily heavy metals. These large mining-induced footprints are often located across vast geographic expanses and are difficult to access. With the continuing advancement of imaging satellites, remote sensing may provide a useful monitoring tool for pit lake water quality and the rapid assessment of abandoned mine sites. This study explored the applications of laboratory spectroscopy and multi-season hyperspectral remote sensing for environmental monitoring of mine waste environments. Laboratory spectral experiments were first performed on acid mine waters and synthetic ferric iron solutions to identify and isolate the unique spectral properties of mine waters. These spectral characterizations were then applied to airborne hyperspectral imagery for identification of poor water quality in AMD ponds at the Leviathan Mine Superfund site, CA. Finally, imagery varying in temporal and spatial resolutions were used to identify changes in mineralogy over weathering overburden piles and on dry AMD pond liner surfaces at the Leviathan Mine. Results show the utility of hyperspectral remote sensing for monitoring a diverse range of surfaces associated with AMD.

  2. Geochemistry of rare earth elements in a passive treatment system built for acid mine drainage remediation.

    PubMed

    Prudêncio, Maria Isabel; Valente, Teresa; Marques, Rosa; Sequeira Braga, Maria Amália; Pamplona, Jorge

    2015-11-01

    Rare earth elements (REE) were used to assess attenuation processes in a passive system for acid mine drainage treatment (Jales, Portugal). Hydrochemical parameters and REE contents in water, soils and sediments were obtained along the treatment system, after summer and winter. A decrease of REE contents in the water resulting from the interaction with limestone after summer occurs; in the wetlands REE are significantly released by the soil particles to the water. After winter, a higher water dynamics favors the AMD treatment effectiveness and performance since REE contents decrease along the system; La and Ce are preferentially sequestered by ochre sludge but released to the water in the wetlands, influencing the REE pattern of the creek water. Thus, REE fractionation occurs in the passive treatment systems and can be used as tracer to follow up and understand the geochemical processes that promote the remediation of AMD. PMID:26247412

  3. Gill lesions and death of bluegill in an acid mine drainage mixing zone

    USGS Publications Warehouse

    Henry, T.B.; Irwin, E.R.; Grizzle, J.M.; Brumbaugh, W.G.; Wildhaber, M.L.

    2001-01-01

    The toxicity of an acid mine drainage (AMD) mixing zone was investigated by placing bluegill (Lepomis macrochirus) at the confluence of a stream contaminated by AMD and a stream having neutral pH. A mixing channel receiving water from both streams was assembled in the field, during July and October 1996, to determine the toxicity of freshly mixed and aged water (2.9-7.5 min). The AMD stream had elevated concentrations of Al and Fe, which precipitated upon mixing, and of Mn, which did not precipitate in the mixing zone. Fish exposed to freshly mixed water had higher mortality than fish exposed to water after aging. Precipitating Al, but not Fe, accumulated on the gills of bluegill, and accumulation was more rapid early during the mixing process than after aging. Fish exposed for 3.5 h to freshly mixed water had hypertrophy and hyperplasia of gill filament and lamellar epithelial cells. Similar lesions were observed after 6.0 h in fish exposed to water aged after mixing. Results demonstrated that Al was the predominant metal accumulating on the gills of fish in this AMD mixing zone, and that mixing zones can be more toxic than AMD streams in equilibrium.

  4. Application of acid mine drainage for coagulation/flocculation of microalgal biomass.

    PubMed

    Salama, El-Sayed; Kim, Jung Rae; Ji, Min-Kyu; Cho, Dong-Wan; Abou-Shanab, Reda A I; Kabra, Akhil N; Jeon, Byong-Hun

    2015-06-01

    A novel application of acid mine drainage (AMD) for biomass recovery of two morphologically different microalgae species with respect to AMD dosage, microalgal cell density and pH of medium was investigated. Optimal flocculation of Scenedesmus obliquus and Chlorella vulgaris occurred with 10% dosage of AMD at an initial pH 9 for both 0.5 and 1.0 g/L cell density. The flocculation efficiency was 89% for S. obliquus and 93% for C. vulgaris. Zeta potential (ZP) was increased from -10.66 to 1.77 and -13.19 to 1.33 for S. obliquus and C. vulgaris, respectively. Scanning electron microscope with energy-dispersive X-ray of the microalgae floc confirmed the sweeping floc formation mechanism upon the addition of AMD. Application of AMD for the recovery of microalgae biomass is a cost-effective method, which might further allow reuse of flocculated medium for algal cultivation, thereby contributing to the economic production of biofuel from microalgal biomass. PMID:25817034

  5. Interaction of acid mine drainage with Ordinary Portland Cement blended solid residues generated from active treatment of acid mine drainage with coal fly ash.

    PubMed

    Gitari, Wilson M; Petrik, Leslie F; Key, David L; Okujeni, Charles

    2011-01-01

    Fly ash (FA) has been investigated as a possible treatment agent for Acid mine drainage (AMD) and established to be an alternative, cheap and economically viable agent compared to the conventional alkaline agents. However, this treatment option also leads to generation of solid residues (SR) that require disposal and one of the proposed disposal method is a backfill in coal mine voids. In this study, the interaction of the SR with AMD that is likely to be present in such backfill scenario was simulated by draining columns packed with SR and SR + 6% Ordinary Portland Cement (OPC) unsaturated with simulated AMD over a 6 month period. The evolving geochemistry of the liquid/solid (L/S) system was evaluated in-terms of the mineral phases likely or controlling contaminants attenuation at the different pH regimes generated. Stepwise acidification of the percolates was observed as the drainage progressed. Two pH buffer zones were observed (7.5-9 and 3-4) for SR and (11.2-11.3 and 3.5-4) for SR + 6% OPC. The solid residue cores (SR) appeared to have a significant buffering capacity, maintaining a neutral to slightly alkaline pH in the leachates for an extended period of time (97 days: L/S 4.3) while SR + 6% OPC reduced this neutralization capacity to 22 days (L/S 1.9). Interaction of AMD with SR or SR + 6% OPC generated alkaline conditions that favored precipitation of Fe, Al, Mn-(oxy) hydroxides, Fe and Ca-Al hydroxysulphates that greatly contributed to the contaminants removal. However, precipitation of these phases was restricted to the pH of the leachates remaining at neutral to circum-neutral levels. Backfill of mine voids with SR promises to be a feasible technology for the disposal of the SR but its success will greatly depend on the disposal scenario, AMD generated and the alkalinity generating potential of the SR. A disadvantage would be the possible re-dissolution of the precipitated phases at pH < 4 that would release the contaminants back to the water column

  6. Handbook for constructed wetlands receiving acid mine drainage

    SciTech Connect

    Wildeman, T.; Dietz, J.; Gusek, J.; Morea, S.

    1993-09-01

    In the summer of 1987, a pilot constructed wetland was built at the Big Five Tunnel in Idaho Springs, Colorado. The report details the theory, design and construction of wetlands receiving acid mine drainages, based on the second and third year of operation of this wetland, which was funded by the U.S. Environmental Protection Agency under the SITE Emerging Technologies Program. The text is divided into two broad sections: Part A - Theoretical Development, and Part B - Design Consideration. In the latter sections of Part A and through all of Part B the focus is on removal of metals by precipitation of sulfides through the activity of sulfate reducing bacteria.

  7. Radium and barium removal through blending hydraulic fracturing fluids with acid mine drainage.

    PubMed

    Kondash, Andrew J; Warner, Nathaniel R; Lahav, Ori; Vengosh, Avner

    2014-01-21

    Wastewaters generated during hydraulic fracturing of the Marcellus Shale typically contain high concentrations of salts, naturally occurring radioactive material (NORM), and metals, such as barium, that pose environmental and public health risks upon inadequate treatment and disposal. In addition, fresh water scarcity in dry regions or during periods of drought could limit shale gas development. This paper explores the possibility of using alternative water sources and their impact on NORM levels through blending acid mine drainage (AMD) effluent with recycled hydraulic fracturing flowback fluids (HFFFs). We conducted a series of laboratory experiments in which the chemistry and NORM of different mix proportions of AMD and HFFF were examined after reacting for 48 h. The experimental data combined with geochemical modeling and X-ray diffraction analysis suggest that several ions, including sulfate, iron, barium, strontium, and a large portion of radium (60-100%), precipitated into newly formed solids composed mainly of Sr barite within the first ∼ 10 h of mixing. The results imply that blending AMD and HFFF could be an effective management practice for both remediation of the high NORM in the Marcellus HFFF wastewater and beneficial utilization of AMD that is currently contaminating waterways in northeastern U.S.A. PMID:24367969

  8. Selection of Clostridium spp. in biological sand filters neutralizing synthetic acid mine drainage.

    PubMed

    Ramond, Jean-Baptiste; Welz, Pamela J; Le Roes-Hill, Marilize; Tuffin, Marla I; Burton, Stephanie G; Cowan, Don A

    2014-03-01

    In this study, three biological sand filter (BSF) were contaminated with a synthetic iron- [1500 mg L⁻¹ Fe(II), 500 mg L⁻¹ Fe(III)] and sulphate-rich (6000 mg L⁻¹ SO₄²⁻) acid mine drainage (AMD) (pH = 2), for 24 days, to assess the remediation capacity and the evolution of autochthonous bacterial communities (monitored by T-RFLP and 16S rRNA gene clone libraries). To stimulate BSF bioremediation involving sulphate-reducing bacteria, a readily degradable carbon source (glucose, 8000 mg L⁻¹) was incorporated into the influent AMD. Complete neutralization and average removal efficiencies of 81.5 (±5.6)%, 95.8 (±1.2)% and 32.8 (±14.0)% for Fe(II), Fe(III) and sulphate were observed, respectively. Our results suggest that microbial iron reduction and sulphate reduction associated with iron precipitation were the main processes contributing to AMD neutralization. The effect of AMD on BSF sediment bacterial communities was highly reproducible. There was a decrease in diversity, and notably a single dominant operational taxonomic unit (OTU), closely related to Clostridium beijerinckii, which represented up to 65% of the total community at the end of the study period. PMID:24251832

  9. Influences of acid mine drainage and thermal enrichment on stream fish reproduction and larval survival

    USGS Publications Warehouse

    Hafs, Andrew W.; Horn, C.D.; Mazik, P.M.; Hartman, K.J.

    2010-01-01

    Potential effects of acid mine drainage (AMD) and thermal enrichment on the reproduction of fishes were investigated through a larval-trapping survey in the Stony River watershed, Grant County, WV. Trapping was conducted at seven sites from 26 March to 2 July 2004. Overall larval catch was low (379 individuals in 220 hours of trapping). More larval White Suckers were captured than all other species. Vectors fitted to nonparametric multidimensional scaling ordinations suggested that temperature was highly correlated to fish communities captured at our sites. Survival of larval Fathead Minnows was examined in situ at six sites from 13 May to 11 June 2004 in the same system. Larval survival was lower, but not significantly different between sites directly downstream of AMD-impacted tributaries (40% survival) and non-AMD sites (52% survival). The lower survival was caused by a significant mortality event at one site that coincided with acute pH depression in an AMD tributary immediately upstream of the site. Results from a Cox proportional hazard test suggests that low pH is having a significant negative influence on larval fish survival in this system. The results from this research indicate that the combination of low pH events and elevated temperature are negatively influencing the larval fish populations of the Stony River watershed. Management actions that address these problems would have the potential to substantially increase both reproduction rates and larval survival, therefore greatly enhancing the fishery.

  10. Microbial Communities in Biofilms of an Acid Mine Drainage Site Determined by Phospholipid Analysis

    NASA Astrophysics Data System (ADS)

    Das Gupta, S.; Fang, J.

    2008-12-01

    Phospholipids were extracted to determine the microbial biomass and community structure of biofims from an acid mine drainage (AMD) at the Green Valley coal mine site (GVS) in western Indiana. The distribution of specific biomarkers indicated the presence of a variety of microorganisms. Phototrophic microeukaryotes, which include Euglena mutabilis, algae, and cyanobacteria were the most dominant organisms, as indicated by the presence of polyunsaturated fatty acids. The presence of terminally methyl branched fatty acids suggests the presence of Gram-positive bacteria, and the mid-methyl branched fatty acids indicates the presence of sulfate-reducing bacteria. Fungi appear to also be an important part of the AMD microbial communities as suggested by the presence of 18:2 fatty acid. The acidophilic microeukaryotes Euglena dominated the biofilm microbial communities. These microorganisms appear to play a prominent role in the formation and preservation of stromatolites and in releasing oxygen to the atmosphere by oxygenic photosynthesis. Thus, the AMD environment comprises a host of microorganisms spreading out within the phylogenetic tree of life. Novel insights on the roles of microbial consortia in the formation and preservation of stromatolites and the production of oxygen through photosynthesis in AMD systems may have significance in the understanding of the interaction of Precambrian microbial communities in environments that produced microbially-mediated sedimentary structures and that caused oxygenation of Earth's atmosphere.

  11. An analysis of the effectiveness of a constructed wetland treating acid mine drainage

    SciTech Connect

    Huddleston, G.M. III; Grant, A.J.; Ramey, B.A.

    1994-12-31

    Acid mine drainage (AMD) from an abandoned coal mine in southcentral Kentucky had pH levels as low as 2.3 and iron concentrations as high as 641 mg/L. In the summer of 1992, the US Soil Conservation Service constructed a wetland system to treat the AMD that incorporated both physical and biological treatments. The AMD was initially fed into three anoxic limestone beds followed by an aeration pond and four cattail cells. A polishing pond served as the final stage of treatment. Flow of AMD was initiated in the fall of 1992, and treatment effectiveness was monitored for the next year. Chemical analysis and the cladoceran (Ceriodaphnia dubia) survival and reproduction test were performed on water samples collected along the flow path. Water chemistry analysis and determination of toxic levels indicated a substantial increase in pH and removal of metals prior to entering the cattail cells. Water quality in the cattail cells and polishing pond varied throughout the seasons, but had improved substantially by the end of the one-year monitoring period. The use of the wetland system by macroinvertebrates also was evaluated. Results indicated that a limited number of species were found in the cattail cells, while larger numbers were recovered from the polishing pond.

  12. Response of soil-associated microbial communities to intrusion of coal mine-derived acid mine drainage.

    PubMed

    Brantner, Justin S; Senko, John M

    2014-01-01

    A system has been identified in which coal mine-derived acid mine drainage (AMD) flows as a 0.5-cm-deep sheet over the terrestrial surface. This flow regime enhances the activities of Fe(II) oxidizing bacteria, which catalyze the oxidative precipitation of Fe from AMD. These activities give rise to Fe(III) (hydr)oxide-rich deposits (referred to as an iron mound) overlying formerly pristine soil. This iron mound has developed with no human intervention, indicating that microbiological activities associated with iron mounds may be exploited as an inexpensive and sustainable approach to remove Fe(II) from AMD. To evaluate the changes in microbial activities and communities that occur when AMD infiltrates initially pristine soil, we incubated AMD-unimpacted soil with site AMD. Continuous exposure of soil to AMD induced progressively greater rates of Fe(II) biooxidation. The development of Fe(II) oxidizing activities was enhanced by inoculation of soil with microorganisms associated with mature iron mound sediment. Evaluation of pyrosequencing-derived 16S rRNA gene sequences recovered from incubations revealed the development of microbial community characteristics that were similar to those of the mature iron mound sediment. Our results indicate that upon mixing of AMD with pristine soil, microbial communities develop that mediate rapid oxidative precipitation of Fe from AMD. PMID:24971467

  13. Response of macroinvertebrate communities to remediation-simulating conditions in Pennsylvania streams influenced by acid mine drainage

    USGS Publications Warehouse

    Ross, R.M.; Long, E.S.; Dropkin, D.S.

    2008-01-01

    We compared naturally alkaline streams with limestone lithology to freestone streams with and without acid mine drainage (AMD) to predict benthic macroinvertebrate community recovery from AMD in limestone-treated watersheds. Surrogate-recovered (limestone) and, in many cases, freestone systems had significantly higher macroinvertebrate densities; diversity; taxa richness; Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa; EPT/chironomid ratios; scraper/collector - gatherer ratios; herbivores; collector - filterers; and scrapers. AMD-influenced systems had significantly greater numbers of Diptera and collector - gatherers. An entire trophic level (herbivores) was 'restored' in surrogate-recovered streams, which also showed greater trophic specialization. Indicator analysis identified seven taxa (within Crustacea, Diptera, Nematoda, Trichoptera, and Ephemeroptera) as significant indicators of limestone systems and six taxa (within Ephemeroptera, Plecoptera, Tricoptera, Coleoptera, and Mollusca) as significant freestone indicators, all useful as biological indicators of recovery from AMD. ?? Springer Science+Business Media B.V. 2007.

  14. Removal and recovery of metal ions from acid mine drainage using lignite--A low cost sorbent.

    PubMed

    Mohan, Dinesh; Chander, Subhash

    2006-10-11

    Acid mine drainage (AMD), has long been a significant environmental problem resulting from the microbial oxidation of iron pyrite in presence of water and air, affording an acidic solution that contains toxic metal ions. The main objective of this study was to remove and recover metal ions from acid mine drainage (AMD) by using lignite, a low cost sorbent. Lignite has been characterized and used for the AMD treatment. Sorption of ferrous, ferric, manganese, zinc and calcium in multi-component aqueous systems was investigated. Studies were performed at different pH to find optimum pH. To simulate industrial conditions for acid mine wastewater treatment, all the studies were performed using single and multi-columns setup in down flow mode. The empty bed contact time (EBCT) model was used for minimizing the sorbent usage. Recovery of the metal ions as well as regeneration of sorbent was achieved successfully using 0.1 M nitric acid without dismantling the columns. PMID:16784810

  15. Inhibition of bacterial activity in acid mine drainage

    NASA Astrophysics Data System (ADS)

    Singh, Gurdeep; Bhatnagar, Miss Mridula

    1988-12-01

    Acid mine drainage water give rise to rapid growth and activity of an iron- and sulphur- oxidizing bacterium Thiobacillus ferrooxidians which greatly accelerate acid producing reactions by oxidation of pyrite material associated with coal and adjoining strata. The role of this bacterium in production of acid mine drainage is described. This study presents the data which demonstrate the inhibitory effect of certain organic acids, sodium benzoate, sodium lauryl sulphate, quarternary ammonium compounds on the growth of the acidophilic aerobic autotroph Thiobacillus ferrooxidians. In each experiment, 10 milli-litres of laboratory developed culture of Thiobacillus ferrooxidians was added to 250 milli-litres Erlenmeyer flask containing 90 milli-litres of 9-k media supplemented with FeSO4 7H2O and organic compounds at various concentrations. Control experiments were also carried out. The treated and untreated (control) samples analysed at various time intervals for Ferrous Iron and pH levels. Results from this investigation showed that some organic acids, sodium benzoate, sodium lauryl sulphate and quarternary ammonium compounds at low concentration (10-2 M, 10-50 ppm concentration levels) are effective bactericides and able to inhibit and reduce the Ferrous Iron oxidation and acidity formation by inhibiting the growth of Thiobacillus ferrooxidians is also discussed and presented

  16. Implications for global climate change from microbially-produced acid mine drainage

    NASA Astrophysics Data System (ADS)

    Norlund, K. L.; Hitchcock, A. P.; Warren, L. A.

    2009-05-01

    Microbial catalysis of sulphur cycling in acid mine drainage (AMD) environments is well known but the reaction pathways are poorly characterised. These reaction pathways involve both acid-consuming and acid- generating steps, with important consequences for overall AMD production as well as sulphur and carbon global biogeochemical cycles. Mining-associated sulphuric acid has been implicated in climate change through the weathering of carbonate minerals resulting in the release of 29 Tg C/year as carbon dioxide. Understanding of microbial AMD generation is based predominantly on studies of Acidithiobacillus ferrooxidans despite the knowledge that other environmentally common strains of bacteria are also active sulphur oxidizers and that microbial consortia are likely very important in environmental processes. Using an integrated experimental approach including geochemical experimentation, scanning transmission X-ray microscopy (STXM) and fluorescent in situ hybridization (FISH), we document a novel syntrophic sulphur metabolism involving two common mine bacteria: autotrophic sulphur oxidizing Acidithiobacillus ferrooxidans and heterotrophic Acidiphilium spp. The proposed sulphur geochemistry associated with this bacterial consortium produces 40-90% less acid than expected based on abiotic AMD models, with significant implications for both AMD mitigation and AMD carbon flux modelling. The two bacterial strains are specifically spatially segregated within a macrostructure of extracellular polymeric substance (EPS) that provides the necessary microgeochemical conditions for coupled sulphur oxidation and reduction reactions. STXM results identify multiple sulphur oxidation states associated with the pods, indicating that they are the sites of active sulphur disproportionation and recycling. Recent laboratory experimentation using type culture strains of the bacteria involved in pod-formation suggesting that this phenomenon is likely to be widespread in environments

  17. A combined CaO/electrochemical treatment of the acid mine drainage from the "Robule" Lake.

    PubMed

    Orescanin, Visnja; Kollar, Robert

    2012-01-01

    The purpose of this work was development and application of the purification system suitable for the treatment of the acid mine drainage (AMD) accumulated in the "Robule" Lake, which represents the part of the Bor copper mining and smelting complex, Serbia. The study was undertaken in order to minimize adverse effect on the environment caused by the discharge of untreated AMD, which was characterized with low pH value (2.63) and high concentration of heavy metals (up to 610 mg/L) and sulfates (up to 12,000 mg/L). The treatment of the effluent included pretreatment/pH adjustment with CaO followed by electrocoagulation using iron and aluminum electrode sets. Following the final treatment, the decrease in the concentration of heavy metals ranged from 40 up to 61000 times depending on the metal and its initial concentration. The parameters, color and turbidity were removed completely in the pretreatment step, while the removal efficiencies for other considered parameters were as follows: EC = 55.48%, SO(4) (2-) = 70.83%, Hg = 98.36%, Pb = 97.50%, V = 98.43%, Cr = 99.86%, Mn = 97.96%, Fe = 100.00%, Co = 99.96%, Ni = 99.78%, Cu = 99.99% and Zn = 99.94%. Because the concentrations of heavy metals in the electrochemically treated AMD (ranging from 0.001 to 0.336 mg/L) are very low, the negative impact of this effluent on the aquatic life and humans is not expected. The sludge generated during the treatment of AMD is suitable for reuse for at least two purposes (pretreatment of AMD and covering of the flotation waste heap). From the presented results, it could be concluded that electrochemical treatment is a suitable approach for the treatment of AMD. PMID:22506711

  18. Pathways of acid mine drainage to Clear Lake: implications for mercury cycling.

    PubMed

    Shipp, William G; Zierenberg, Robert A

    2008-12-01

    Pore fluids from Clear Lake sediments collected near the abandoned Sulphur Bank Mercury Mine have low pH (locally <4) and elevated sulfate (> or =197 mmol/L), aluminum (> or =52 mmol/L), and iron (> or =28 mmol/L) contents derived from oxidation of sulfide minerals at the mine site. Acid mine drainage (AMD) is entering Clear Lake by advective subsurface flow nearest the mine and by diffusion at greater distances. Oxygen and hydrogen isotope ratios, combined with pore fluid compositions, constrain the sources and pathways of contaminated fluids. Sediment cores taken nearest the mine have the highest concentrations of dissolved sulfate, aluminum, and iron, which are contributed by direct subsurface flow of AMD from sulfide-bearing waste rock. Sediment cores as far as 100 m west of the Clear Lake shoreline show the presence of AMD that originated in the acidic lake that occupies the abandoned Herman Pit at the mine site. High sulfate content in the AMD has the potential to promote the activity of sulfate-reducing bacteria in the organic-rich lake sediments, which leads to methylation of Hg+2, making it both more toxic and bioavailable. Quantitative depletion of pore water sulfate at depth and sulfur isotope values of diagenetic pyrite near 0 per thousand indicate that sulfate availability limits the extent of sulfate reduction in the lake sediments away from the mine. Profiles of pore water sulfate in the sediments near the mine show that excess sulfate is available to support the activity of sulfate-reducing bacteria near the mine site. Enriched isotope values of dissolved sulfate (as high as 17.1 per thousand) and highly depleted isotope values for diagenetic pyrite (as low as -22.6 per thousand) indicate active bacterial sulfate reduction in the AMD-contaminated sediments. Sulfate- and iron-rich acid mine drainage entering Clear Lake by shallow subsurface flow likely needs to be controlled in order to lower the environmental impacts of Hg in the Clear Lake

  19. Bioassessment of a combined chemical-biological treatment for synthetic acid mine drainage.

    PubMed

    Pagnanelli, F; De Michelis, I; Di Muzio, S; Ferella, F; Vegliò, F

    2008-11-30

    In this work, ecotoxicological characteristics of synthetic samples of acid mine drainage (AMD) before and after a combined chemical-biological treatment were investigated by using Lepidium sativum and Daphnia magna. AMD treatment was performed in a two-column apparatus consisting of chemical precipitation by limestone and biological refinement by sulphate reducing bacteria. Synthetic samples of AMD before treatment were toxic for both L. sativum (germination index, G, lower than 10%) and D. magna (100% immobility) due to acid pH and presence of copper and zinc. Chemical treatment (raising pH to 5-6 and eliminating copper) generated effluents with reduced toxicity for L. sativum (G=33%), while 100% immobility was still observed for D. magna. Dynamic trends of toxicity for the first and fifth outputs of the biological column denoted a gradual improvement leading to hormesis for Lepidium (after the initial release of organic excess), while a constant residual toxicity remained for Daphnia (probably due to H(2)S produced by sulphate reducing bacteria). PMID:18394799

  20. Contemporary environmental variation determines microbial diversity patterns in acid mine drainage

    PubMed Central

    Kuang, Jia-Liang; Huang, Li-Nan; Chen, Lin-Xing; Hua, Zheng-Shuang; Li, Sheng-Jin; Hu, Min; Li, Jin-Tian; Shu, Wen-Sheng

    2013-01-01

    A wide array of microorganisms survive and thrive in extreme environments. However, we know little about the patterns of, and controls over, their large-scale ecological distribution. To this end, we have applied a bar-coded 16S rRNA pyrosequencing technology to explore the phylogenetic differentiation among 59 microbial communities from physically and geochemically diverse acid mine drainage (AMD) sites across Southeast China, revealing for the first time environmental variation as the major factor explaining community differences in these harsh environments. Our data showed that overall microbial diversity estimates, including phylogenetic diversity, phylotype richness and pairwise UniFrac distance, were largely correlated with pH conditions. Furthermore, multivariate regression tree analysis also identified solution pH as a strong predictor of relative lineage abundance. Betaproteobacteria, mostly affiliated with the ‘Ferrovum' genus, were explicitly predominant in assemblages under moderate pH conditions, whereas Alphaproteobacteria, Euryarchaeota, Gammaproteobacteria and Nitrospira exhibited a strong adaptation to more acidic environments. Strikingly, such pH-dependent patterns could also be observed in a subsequent comprehensive analysis of the environmental distribution of acidophilic microorganisms based on 16S rRNA gene sequences previously retrieved from globally distributed AMD and associated environments, regardless of the long-distance isolation and the distinct substrate types. Collectively, our results suggest that microbial diversity patterns are better predicted by contemporary environmental variation rather than geographical distance in extreme AMD systems. PMID:23178673

  1. Acid mine drainage on public and private lands, the Walker Mine experience, Plumas County, California

    SciTech Connect

    Croyle, W.A.; Rosenbaum, S.E.

    1996-11-01

    A widespread environmental problem associated with abandoned mines and their tailings is acid mine drainage (AMD). AMID typically has low pH and elevated metal concentrations that are toxic to aquatic life. In Northern California, Iron Mountain and other mines in the Shasta mining districts are the largest sources of AMD. Additional sources lie to the south along a discontinuous belt of copper and zinc mineralization in the western Sierra foothills. Between these areas lies a remote group of copper mines in northeastern Plumas County including the Walker, Engels and Superior mines. Of this group, AMD from Walker Mine has caused the most severe water quality impairment. This paper describes the history and environmental setting of Walker Mine and the approaches used by the Central Valley Regional Water Quality Control Board, a state regulatory agency, to improve water quality at the site. Both the mine and its tailings contribute pollutants to the watershed. The mine has a portal discharge with depressed pH and high copper concentrations. The tailings add fine grained sediment to the creek and generate low but significant concentrations of dissolved copper. The mine is on private property and the tailings are on land managed by the U. S. Forest Service. Because of these differences in pollution problems and ownership, the methods employed by the Regional Board to improve conditions at the mine and tailings have been on different, but parallel tracks. Monitoring shows these efforts have significantly improved water quality in the watershed over the last 10 years.

  2. Wine wastes as carbon source for biological treatment of acid mine drainage.

    PubMed

    Costa, M C; Santos, E S; Barros, R J; Pires, C; Martins, M

    2009-05-01

    Possible use of wine wastes containing ethanol as carbon and energy source for sulphate-reducing bacteria (SRB) growth and activity in the treatment of acid mine drainage (AMD) is studied for the first time. The experiments were performed using anaerobic down-flow packed bed reactors in semi-continuous systems. The performance of two bioreactors fed with wine wastes or ethanol as carbon sources is compared in terms of sulphate reduction, metals removal and neutralization. The results show that efficient neutralization and high sulphate removal (>90%) were attained with the use of wine wastes as substrate allowing the production of effluents with concentrations below the required local legislation for irrigation waters. This is only possible provided that the AMD and wine wastes are contacted with calcite tailing, a waste material that neutralizes and provides buffer capacity to the medium. The removal of metals using wine wastes as carbon source was 61-91% for Fe and 97% for both Zn and Cu. The lower removal of iron, when wine waste is used instead of ethanol, may be due to the presence of iron-chelating compounds in the waste, which prevent the formation of iron sulphide, and partial unavailability of sulphide because of re-oxidation to elemental sulphur. However, that did not affect significantly the quality of the effluent for irrigation. This work demonstrates that wine wastes are a potential alternative to traditional SRB substrates. This finding has direct implication to sustainable operation of SRB bioreactors for AMD treatment. PMID:19201010

  3. Characterization of the microbial acid mine drainage microbial community using culturing and direct sequencing techniques.

    PubMed

    Auld, Ryan R; Myre, Maxine; Mykytczuk, Nadia C S; Leduc, Leo G; Merritt, Thomas J S

    2013-05-01

    We characterized the bacterial community from an AMD tailings pond using both classical culturing and modern direct sequencing techniques and compared the two methods. Acid mine drainage (AMD) is produced by the environmental and microbial oxidation of minerals dissolved from mining waste. Surprisingly, we know little about the microbial communities associated with AMD, despite the fundamental ecological roles of these organisms and large-scale economic impact of these waste sites. AMD microbial communities have classically been characterized by laboratory culturing-based techniques and more recently by direct sequencing of marker gene sequences, primarily the 16S rRNA gene. In our comparison of the techniques, we find that their results are complementary, overall indicating very similar community structure with similar dominant species, but with each method identifying some species that were missed by the other. We were able to culture the majority of species that our direct sequencing results indicated were present, primarily species within the Acidithiobacillus and Acidiphilium genera, although estimates of relative species abundance were only obtained from direct sequencing. Interestingly, our culture-based methods recovered four species that had been overlooked from our sequencing results because of the rarity of the marker gene sequences, likely members of the rare biosphere. Further, direct sequencing indicated that a single genus, completely missed in our culture-based study, Legionella, was a dominant member of the microbial community. Our results suggest that while either method does a reasonable job of identifying the dominant members of the AMD microbial community, together the methods combine to give a more complete picture of the true diversity of this environment. PMID:23485423

  4. Utilizing acid mine drainage sludge and coal fly ash for phosphate removal from dairy wastewater.

    PubMed

    Wang, Y R; Tsang, Daniel C W; Olds, William E; Weber, Paul A

    2013-01-01

    This study aims to investigate a new and sustainable approach for the reuse of industrial by-products from wastewater treatment. The dairy industry produces huge volumes of wastewater, characterized by high levels of phosphate that can result in eutrophication and degradation of aquatic ecosystems. This study evaluated the application of acid mine drainage (AMD) sludge, coal fly ash, and lignite as low-cost adsorbents for the removal of phosphate from dairy wastewater. Material characterization using X-ray fluorescence, X-ray diffraction, and Brunauer-Emmett-Teller surface area analysis revealed significant amounts of crystalline/amorphous Fe/Al/Si/Ca-based minerals and large surface areas of AMD sludge and fly ash. Batch adsorption isotherms were best described using the Freundlich model. The Freundlich distribution coefficients were 13.7 mg(0.577) L(0.423) g(-1) and 16.9 mg(0.478) L(0.522) g(-1) for AMD sludge and fly ash, respectively, and the nonlinearity constants suggested favourable adsorption for column applications. The breakthrough curves of fixed-bed columns, containing greater than 10 wt% of the waste materials (individual or composite blends) mixed with sand, indicated that phosphate breakthrough did not occur within 100 pore volumes while the cumulative removal was 522 and 490 mg kg(-1) at 10 wt% AMD sludge and 10 wt% fly ash, respectively. By contrast, lignite exhibited negligible phosphate adsorption, possibly due to small amounts of inorganic minerals suitable for phosphate complexation and limited surface area. The results suggest that both AMD sludge and fly ash were potentially effective adsorbents if employed individually at a ratio of 10 wt% or above for column application. PMID:24617077

  5. Acid mine drainage. (Latest citations from the Selected Water Resources Abstracts data base). Published Search

    SciTech Connect

    Not Available

    1992-08-01

    The bibliography contains citations concerning the control and treatment of acid mine drainage. Techniques discussed for treating wastes containing heavy metals include precipitation, cementation, ion exchange, charge membrane, ultrafiltration, ozonation, solvent extraction, and electrodialysis. The environmental impacts of acid mine drainage on rivers, streams, and lakes are also discussed. (Contains 250 citations and includes a subject term index and title list.)

  6. Treatment and prevention systems for acid mine drainage and halogenated contaminants

    SciTech Connect

    Jin, Song; Fallgren, Paul H.; Morris, Jeffrey M.

    2012-01-31

    Embodiments include treatments for acid mine drainage generation sources (10 perhaps by injection of at least one substrate (11) and biologically constructing a protective biofilm (13) on acid mine drainage generation source materials (14). Further embodiments include treatments for degradation of contaminated water environments (17) with substrates such as returned milk and the like.

  7. Acid mine drainage. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-09-01

    The bibliography contains citations concerning the control and treatment of acid mine drainage. Techniques discussed for treating wastes containing heavy metals include precipitation, cementation, ion exchange, charge membrane, ultrafiltration, ozonation, solvent extraction, and electrodialysis. The environmental impacts of acid mine drainage on rivers, streams, and lakes are also discussed. (Contains 250 citations and includes a subject term index and title list.)

  8. Acid mine drainage. (Latest citations from the Selected Water Resources Abstracts database). Published Search

    SciTech Connect

    Not Available

    1993-11-01

    The bibliography contains citations concerning the control and treatment of acid mine drainage. Techniques discussed for treating wastes containing heavy metals include precipitation, cementation, ion exchange, charge membrane, ultrafiltration, ozonation, solvent extraction, and electrodialysis. The environmental impacts of acid mine drainage on rivers, streams, and lakes are also discussed. (Contains 250 citations and includes a subject term index and title list.)

  9. Airborne remote sensing of coal waste and acid mine drainage

    SciTech Connect

    Kim, K.E.; Lee, T.S.

    1996-07-01

    High resolution airborne remote sensing data, spatial resolution of 2m X 2m, were used to study the stream quality degradation due to the coal mines in Taebaek city, one of the major coalfields in Korea. In order to circumvent the severe topographic effect and small scale of the water stream, principal components with the least variances were utilized. They showed the subtle details in the image that were obscured by higher contrast due to the topographic effect. Through maximum likelihood classification of those components, yellowboy and mine waste could be effectively identified. Areas affected by acid mine drainage and mine waste could be also located by identifying areas of dead or dying vegetation using vegetation index map.

  10. Enhancement of bacterial iron and sulfate respiration for in situ bioremediation of acid mine drainage sites: a case study

    SciTech Connect

    Bilgin, A.A.; Harrington, J.M.; Silverstein, J.

    2007-08-15

    The prevention of acid mine drainage (AMD) in situ is more attractive than down-gradient treatment alternatives that do not involve source control. AMD source control can be achieved by shifting the microbial activity in the sulfidic rock from pyrite oxidation to anaerobic heterotrophic activity. This is achieved by adding biodegradable organic carbon amendments to the sulfidic rock. This technique was applied to an abandoned coal mine pool in Pennsylvania. The pool had a pH of 3.0 to 3.5. Following treatment, near-neutral pH and decreased effluent heavy metal concentrations were achieved. In situ bioremediation by the enhancement of bacterial iron and sulfate reduction is a promising technology for AMD prevention.

  11. Diversity of the Sediment Microbial Community in the Aha Watershed (Southwest China) in Response to Acid Mine Drainage Pollution Gradients

    PubMed Central

    Sun, Weimin; Sun, Min; Dong, Yiran; Ning, Zengping; Xiao, Enzong; Tang, Song; Li, Jiwei

    2015-01-01

    Located in southwest China, the Aha watershed is continually contaminated by acid mine drainage (AMD) produced from upstream abandoned coal mines. The watershed is fed by creeks with elevated concentrations of aqueous Fe (total Fe > 1 g/liter) and SO42− (>6 g/liter). AMD contamination gradually decreases throughout downstream rivers and reservoirs, creating an AMD pollution gradient which has led to a suite of biogeochemical processes along the watershed. In this study, sediment samples were collected along the AMD pollution sites for geochemical and microbial community analyses. High-throughput sequencing found various bacteria associated with microbial Fe and S cycling within the watershed and AMD-impacted creek. A large proportion of Fe- and S-metabolizing bacteria were detected in this watershed. The dominant Fe- and S-metabolizing bacteria were identified as microorganisms belonging to the genera Metallibacterium, Aciditerrimonas, Halomonas, Shewanella, Ferrovum, Alicyclobacillus, and Syntrophobacter. Among them, Halomonas, Aciditerrimonas, Metallibacterium, and Shewanella have previously only rarely been detected in AMD-contaminated environments. In addition, the microbial community structures changed along the watershed with different magnitudes of AMD pollution. Moreover, the canonical correspondence analysis suggested that temperature, pH, total Fe, sulfate, and redox potentials (Eh) were significant factors that structured the microbial community compositions along the Aha watershed. PMID:25979900

  12. The efficiency of combined CaO/electrochemical treatment in removal of acid mine drainage induced toxicity and genotoxicity.

    PubMed

    Radić, Sandra; Vujčić, Valerija; Cvetković, Želimira; Cvjetko, Petra; Oreščanin, Višnja

    2014-01-01

    Acid mine drainage (AMD) is a by-product of the mining industry that has a detrimental effect on aquatic plant and animal life due to high load of heavy metals and sulfates. In the present study, the toxic and genotoxic potential of AMD prior to and following combination of neutralization/electrocoagulation processes was evaluated using several bioassays and selected parameters. Regardless of pH correction of AMD prior to Daphnia bioassay, high acute toxicity was observed in Daphnia magna. The mine leachate also induced strong phyto-, cyto- and genotoxicity to Allium cepa roots. Short term exposure to AMD inhibited duckweed growth and chlorophyll a content and simultaneously promoted lipid peroxidation and DNA damage despite duckweed capability to upregulate antioxidative defense mechanisms. The results show that observed (geno)toxicity could be related to oxidative stress most probably induced by toxic metal action. However, influence of low pH as a contributing factor in the phytotoxicity of AMD cannot be excluded. The application of combined treatment eliminated genotoxicity and was highly efficient in reducing toxicity of AMD. Thus, the method seems to be suitable for treatment of AMD waters enabling their safe discharge to an aquatic environment. PMID:23895778

  13. Diversity of the Sediment Microbial Community in the Aha Watershed (Southwest China) in Response to Acid Mine Drainage Pollution Gradients.

    PubMed

    Sun, Weimin; Xiao, Tangfu; Sun, Min; Dong, Yiran; Ning, Zengping; Xiao, Enzong; Tang, Song; Li, Jiwei

    2015-08-01

    Located in southwest China, the Aha watershed is continually contaminated by acid mine drainage (AMD) produced from upstream abandoned coal mines. The watershed is fed by creeks with elevated concentrations of aqueous Fe (total Fe > 1 g/liter) and SO4 (2-) (>6 g/liter). AMD contamination gradually decreases throughout downstream rivers and reservoirs, creating an AMD pollution gradient which has led to a suite of biogeochemical processes along the watershed. In this study, sediment samples were collected along the AMD pollution sites for geochemical and microbial community analyses. High-throughput sequencing found various bacteria associated with microbial Fe and S cycling within the watershed and AMD-impacted creek. A large proportion of Fe- and S-metabolizing bacteria were detected in this watershed. The dominant Fe- and S-metabolizing bacteria were identified as microorganisms belonging to the genera Metallibacterium, Aciditerrimonas, Halomonas, Shewanella, Ferrovum, Alicyclobacillus, and Syntrophobacter. Among them, Halomonas, Aciditerrimonas, Metallibacterium, and Shewanella have previously only rarely been detected in AMD-contaminated environments. In addition, the microbial community structures changed along the watershed with different magnitudes of AMD pollution. Moreover, the canonical correspondence analysis suggested that temperature, pH, total Fe, sulfate, and redox potentials (Eh) were significant factors that structured the microbial community compositions along the Aha watershed. PMID:25979900

  14. DEVELOPMENT AND VALIDATION OF AN ACID MINE DRAINAGE TREATMENT PROCESS FOR SOURCE WATER

    SciTech Connect

    Lane, Ann

    2015-12-31

    Throughout Northern Appalachia and surrounding regions, hundreds of abandoned mine sites exist which frequently are the source of Acid Mine Drainage (AMD). AMD typically contains metal ions in solution with sulfate ions which have been leached from the mine. These large volumes of water, if treated to a minimum standard, may be of use in Hydraulic Fracturing (HF) or other industrial processes. This project’s focus is to evaluate an AMD water treatment technology for the purpose of providing treated AMD as an alternative source of water for HF operations. The HydroFlex™ technology allows the conversion of a previous environmental liability into an asset while reducing stress on potable water sources. The technology achieves greater than 95% water recovery, while removing sulfate to concentrations below 100 mg/L and common metals (e.g., iron and aluminum) below 1 mg/L. The project is intended to demonstrate the capability of the process to provide AMD as alternative source water for HF operations. The second budget period of the project has been completed during which Battelle conducted two individual test campaigns in the field. The first test campaign demonstrated the ability of the HydroFlex system to remove sulfate to levels below 100 mg/L, meeting the requirements indicated by industry stakeholders for use of the treated AMD as source water. The second test campaign consisted of a series of focused confirmatory tests aimed at gathering additional data to refine the economic projections for the process. Throughout the project, regular communications were held with a group of project stakeholders to ensure alignment of the project objectives with industry requirements. Finally, the process byproduct generated by the HydroFlex process was evaluated for the treatment of produced water against commercial treatment chemicals. It was found that the process byproduct achieved similar results for produced water treatment as the chemicals currently in use. Further

  15. Combination of Successive Alkalinity Producing System (SAPS) and Aeration for Passive Treatment of Highly Acidic Mine Drainage

    NASA Astrophysics Data System (ADS)

    Oh, C.; Ji, S.

    2015-12-01

    Passive treatment system has been widely used for remediation of mine drainage since its advantage of low installation and maintenance cost. The system, however, has also a disadvantage in assuring remediation and management efficiency if the drainage is highly acidic mine drainage. To remediate acid mine drainage (AMD) especially showing high acidity, passive treatment system which consists of successive alkalinity producing system (SAPS) and subsequent aeration pond was proposed and its mechanisms and efficiency was evaluated in this research. Target AMD was obtained from Waryong coal mine and showed typical characteristics of AMD having high metal concentration and low pH (acidity > 300 mg/L as CaCO3). Four experimental cases were conducted; untreated, treated with SAPS, treated with aeration, treated with SAPS and aeration to compare role and mechanism of each unit. Between organic matter and limestone layer which constitute SAPS, the former eliminated most of Fe(III) and Al in the AMD so that the latter was kept from being clogged by precipitates. Net acidity of the AMD rapidly decreased by supplement of alkalinity at the limestone layer. A primary function of SAPS, producing alkalinity constantly without clogging, was attained due to addition a portion of limestone particle into the organic matter layer. The discharge from SAPS had low ORP and DO values because of an anaerobic environment formed at the organic matter layer although its alkalinity was increased. This water quality was unfavorable for Fe(II) to be oxidized. Installation of aeration pond after SAPS, therefore, could be effective way of enhancing oxidation rate of Fe(II). Among the experimental cases, the combination of SAPS and aeration pond was only able to remediate the AMD. This concluded that to remediate highly acidic mine drainage with passive treatment system, three critical conditions were required; pre-precipitation of Fe(III) and Al at organic matter layer in SAPS, constant alkalinity

  16. Acid Mine Drainage Research in Gauteng Highlighting Impacts on Infrastructure and Innovation of Concrete-Based Remedial Systems

    NASA Astrophysics Data System (ADS)

    Diop, S.; Ekolu, S.; Azene, F.

    2013-12-01

    Acid mine drainage (AMD) is presently one of the most important environmental problems in in the densely populated Gauteng Province, South Africa. The threat of acid mine drainage has demanded short-term interventions (some of which are being implemented by government) but more importantly sustainable long-term innovative solutions. There have been moments of public apprehension with some media reports dubbing the current scenario as a future 'nightmare of biblical proportions' and 'South Africa's own Chernobyl' that could cause dissolving of concrete foundations of buildings and reinforcement steel, leading to collapse of structures. In response to the needs of local and provincial authorities, this research was conducted to (1) generate scientific understanding of the effects of AMD on infrastructure materials and structures, and (2) propose innovative long-term remedial systems based on cementitious materials for potential AMD treatment applications of engineering scale. Two AMD solutions from the goldfields and two others from the coalfields were used to conduct corrosion immersion tests on mild steel, stainless steel, mortars, pastes and concretes. Results show that AMD water from the gold mines is more corrosive than that from the coal mines, the corrosion rate of the former being about twice that of the latter. The functionality of metal components of mild steel can be expected to fail within one month of exposure to the mine water. The investigation has also led to development of a pervious concrete filter system of water-cement ratio = 0.27 and cement content = 360 kg/m3, to be used as a permeable reactive barrier for AMD treatment. Early results show that the system was effective in removing heavy metal contaminants with removal levels of 30% SO4, 99% Fe, 50-83% Mn, 85% Ca, and 30% TDS. Further work is on-going to improve and optimise the system prior to field demonstration studies.

  17. Ecological roles of dominant and rare prokaryotes in acid mine drainage revealed by metagenomics and metatranscriptomics.

    PubMed

    Hua, Zheng-Shuang; Han, Yu-Jiao; Chen, Lin-Xing; Liu, Jun; Hu, Min; Li, Sheng-Jin; Kuang, Jia-Liang; Chain, Patrick S G; Huang, Li-Nan; Shu, Wen-Sheng

    2015-06-01

    High-throughput sequencing is expanding our knowledge of microbial diversity in the environment. Still, understanding the metabolic potentials and ecological roles of rare and uncultured microbes in natural communities remains a major challenge. To this end, we applied a 'divide and conquer' strategy that partitioned a massive metagenomic data set (>100 Gbp) into subsets based on K-mer frequency in sequence assembly to a low-diversity acid mine drainage (AMD) microbial community and, by integrating with an additional metatranscriptomic assembly, successfully obtained 11 draft genomes most of which represent yet uncultured and/or rare taxa (relative abundance <1%). We report the first genome of a naturally occurring Ferrovum population (relative abundance >90%) and its metabolic potentials and gene expression profile, providing initial molecular insights into the ecological role of these lesser known, but potentially important, microorganisms in the AMD environment. Gene transcriptional analysis of the active taxa revealed major metabolic capabilities executed in situ, including carbon- and nitrogen-related metabolisms associated with syntrophic interactions, iron and sulfur oxidation, which are key in energy conservation and AMD generation, and the mechanisms of adaptation and response to the environmental stresses (heavy metals, low pH and oxidative stress). Remarkably, nitrogen fixation and sulfur oxidation were performed by the rare taxa, indicating their critical roles in the overall functioning and assembly of the AMD community. Our study demonstrates the potential of the 'divide and conquer' strategy in high-throughput sequencing data assembly for genome reconstruction and functional partitioning analysis of both dominant and rare species in natural microbial assemblages. PMID:25361395

  18. The chemistry of conventional and alternative treatment systems for the neutralization of acid mine drainage.

    PubMed

    Kalin, Margarete; Fyson, Andrew; Wheeler, William N

    2006-08-01

    The oxidation of pyritic mining waste is a self-perpetuating corrosive process which generates acid mine drainage (AMD) effluent for centuries or longer. The chemical neutralization of these complex, buffered effluents result in unstable, metal-laden sludges, which require disposal to minimize long-term environmental consequences. A variety of passive treatment systems for AMD, developed in the past two decades, combine limestone and organic substrates in constructed wetlands. These systems work well initially but over the longer term fail due to clogging with and the depletion of available organic carbon. However, some ecologically engineered systems, which exploit the activities of acid reducing microbes in the sediment, rely on photosynthesis in the water column as a source of organic matter. The primary productivity in the water column, which also generates some alkalinity, provides electron donors for the microbial reduction processes in the sediment. In its consideration of 'passive' systems, the literature has placed undue emphasis on sulphate reduction; thermodynamical iron reduction is equally important as is the need to prevent iron oxidation. Secondary precipitates of iron play a significant role in sediment-driven biomineralization processes, which affect the anaerobic degradation of organic matter and the stability of the resulting metal sulfides. One such passive system, which utilized a floating root mass as a source of organic carbon, is described. An extensive review of the literature and the chemical and biogeochemical reactions of AMD treatment systems, lead to the conclusion, that sediment based ecological systems offer the greatest potential for the sustainable treatment of AMD. PMID:16375949

  19. Ecological roles of dominant and rare prokaryotes in acid mine drainage revealed by metagenomics and metatranscriptomics

    DOE PAGESBeta

    Hua, Zheng-Shuang; Han, Yu-Jiao; Chen, Lin-Xing; Liu, Jun; Hu, Min; Li, Sheng-Jin; Kuang, Jia-Liang; Chain, Patrick SG; Huang, Li-Nan; Shu, Wen-Sheng

    2014-11-07

    Here we report that high-throughput sequencing is expanding our knowledge of microbial diversity in the environment. Still, understanding the metabolic potentials and ecological roles of rare and uncultured microbes in natural communities remains a major challenge. To this end, we applied a ‘divide and conquer’ strategy that partitioned a massive metagenomic data set (>100 Gbp) into subsets based on K-mer frequency in sequence assembly to a low-diversity acid mine drainage (AMD) microbial community and, by integrating with an additional metatranscriptomic assembly, successfully obtained 11 draft genomes most of which represent yet uncultured and/or rare taxa (relative abundance <1%). We reportmore » the first genome of a naturally occurring Ferrovum population (relative abundance >90%) and its metabolic potentials and gene expression profile, providing initial molecular insights into the ecological role of these lesser known, but potentially important, microorganisms in the AMD environment. Gene transcriptional analysis of the active taxa revealed major metabolic capabilities executed in situ, including carbon- and nitrogen-related metabolisms associated with syntrophic interactions, iron and sulfur oxidation, which are key in energy conservation and AMD generation, and the mechanisms of adaptation and response to the environmental stresses (heavy metals, low pH and oxidative stress). Remarkably, nitrogen fixation and sulfur oxidation were performed by the rare taxa, indicating their critical roles in the overall functioning and assembly of the AMD community. Finally, our study demonstrates the potential of the ‘divide and conquer’ strategy in high-throughput sequencing data assembly for genome reconstruction and functional partitioning analysis of both dominant and rare species in natural microbial assemblages.« less

  20. Toxicity and metal speciation in acid mine drainage treated by passive bioreactors

    SciTech Connect

    Neculita, C.M.; Vigneaul, B.; Zagury, G.J.

    2008-08-15

    Sulfate-reducing passive bioreactors treat acid mine drainage (AMD) by increasing its pH and alkalinity and by removing metals as metal sulfide precipitates. In addition to discharge limits based on physicochemical parameters, however, treated effluent is required to be nontoxic. Acute and sublethal toxicity was assessed for effluent from 3.5-L column bioreactors filled with mixtures of natural organic carbon sources and operated at different hydraulic retention times (HRTs) for the treatment of a highly contaminated AMD. Effluent was first tested for acute (Daphnia magna and Oncorhynchus mykiss) and sublethal (Pseudokirchneriella subcapitata, Ceriodaphnia dabia, and Lemna minor) toxicity. Acute toxicity was observed for D. magna, and a toxicity identification evaluation (TIE) procedure was then performed to identify potential toxicants. Finally, metal speciation in the effluent was determined using ultrafiltration and geochemical modeling for the interpretation of the toxicity results. The 10-d HRT effluent was nonacutely lethal for 0. mykiss but acutely lethal for D. magna. The toxicity to D. magna, however, was removed by 2 h of aeration, and the TIE procedure suggested iron as a cause of toxicity. Sublethal toxicity of the 10-d HRT effluent was observed for all test species, but it was reduced compared to the raw AMD and to a 7.3-d HRT effluent. Data regarding metal speciation indicated instability of both effluents during aeration and were consistent with the toxicity being caused by iron. Column bioreactors in operation for more than nine months efficiently improved the physicochemical quality of highly contaminated AMD at different HRTs.

  1. Metal release from fly ash upon leaching with sulfuric acid or acid mine drainage

    SciTech Connect

    Skousen, J.; Bhumbla, D.K.

    1998-12-31

    Generation of electricity by coal-fired power plants produces large quantities of bottom ash and fly ash. New power plants commonly use fluidized bed combustion (FBC) boilers, which create ashes with high neutralization potential (NP). These ashes, due to their alkaline nature, are often used in surface mine reclamation to neutralize acidity and reduce hydraulic conductivity of disturbed overburdens. Conventional fly ashes from older power plants exhibit a range of pH and NP, with some ashes having neutral or acidic pH and low NP values, and may not be good candidates for supplying alkalinity in reclamation projects. In this study, the authors used two acidic solutions to leach a low NP fly ash (LNP ash) and two FBC ashes (FBC1 and FBC2). After passing 78 pore volumes of sulfuric acid and 129 pore volumes of acid mine drainage (AMD) through these ash materials several trace elements were found at high levels in the leachates. LNP fly ash leachates had high arsenic and selenium concentrations with sulfuric acid leaching, but showed low arsenic and selenium concentrations after leaching with AMD. Leaching with AMD caused the iron and aluminum inherent in AMD to complex these elements and make them unavailable for leaching. Lead, cadmium, and barium concentrations in fly ash leachates were not high enough to cause water pollution problems with either leaching solution. For both leaching solutions, manganese was released from LNP ash at a constant level, FBC1 ash did not release manganese, and FBC2 ash released manganese only after the NP had been exhausted by >60 pore volumes of leaching.

  2. Ecological roles of dominant and rare prokaryotes in acid mine drainage revealed by metagenomics and metatranscriptomics

    PubMed Central

    Hua, Zheng-Shuang; Han, Yu-Jiao; Chen, Lin-Xing; Liu, Jun; Hu, Min; Li, Sheng-Jin; Kuang, Jia-Liang; Chain, Patrick SG; Huang, Li-Nan; Shu, Wen-Sheng

    2015-01-01

    High-throughput sequencing is expanding our knowledge of microbial diversity in the environment. Still, understanding the metabolic potentials and ecological roles of rare and uncultured microbes in natural communities remains a major challenge. To this end, we applied a ‘divide and conquer' strategy that partitioned a massive metagenomic data set (>100 Gbp) into subsets based on K-mer frequency in sequence assembly to a low-diversity acid mine drainage (AMD) microbial community and, by integrating with an additional metatranscriptomic assembly, successfully obtained 11 draft genomes most of which represent yet uncultured and/or rare taxa (relative abundance <1%). We report the first genome of a naturally occurring Ferrovum population (relative abundance >90%) and its metabolic potentials and gene expression profile, providing initial molecular insights into the ecological role of these lesser known, but potentially important, microorganisms in the AMD environment. Gene transcriptional analysis of the active taxa revealed major metabolic capabilities executed in situ, including carbon- and nitrogen-related metabolisms associated with syntrophic interactions, iron and sulfur oxidation, which are key in energy conservation and AMD generation, and the mechanisms of adaptation and response to the environmental stresses (heavy metals, low pH and oxidative stress). Remarkably, nitrogen fixation and sulfur oxidation were performed by the rare taxa, indicating their critical roles in the overall functioning and assembly of the AMD community. Our study demonstrates the potential of the ‘divide and conquer' strategy in high-throughput sequencing data assembly for genome reconstruction and functional partitioning analysis of both dominant and rare species in natural microbial assemblages. PMID:25361395

  3. The reaction of acid mine drainage with fly ash from coal combustion

    SciTech Connect

    Kim, A.G.

    1999-07-01

    The placement of alkaline fly ash in abandoned, reclaimed or active surface coal mines is intended to reduce the amount of acid mine drainage (AMD) produced at such sites by neutralization, inhibition of acid forming bacteria, encapsulation of the pyrite or water diversion. A continuing concern with this application is the potential release of trace elements from the fly ash when it is placed in contact with AMD. To investigate the possible release of antimony, arsenic, barium, boron, cadmium, chromium, cobalt, copper, lead, nickel, selenium, and zinc from fly ash, a series of column leaching tests were conducted. A one kg fly ash sample, placed in a 5-cm by 1 m acrylic columns, was leached at a nominal rate of 250 mL/d for between 30 and 60 days. The leachant solutions were deionized water, and dilute solutions of sulfuric acid and ferric chloride. Leaching tests have been completed on 28 fly ash samples. leachate data, analyzed as the mass extracted with respect to the concentration in the solid, indicate that the release of trace elements is variable, with only barium and zinc extracted at greater than 50 pct of the amount present in the original sample. As a comparison, water quality changes have been monitored at three sites where fly ash grout was injected after reclamation to control AMD. When compared before and after grouting, small increases in pH and decreases in acidity at discharge points were observed. Concentrations of trace metals were found to be comparable in treated and untreated areas. When grouted and ungrouted areas were compared, the effect of the fly ash was shown to be localized in the areas of injection. These studies indicated that when fly ash is used as a reagent to control of AMD, the release of trace elements is relatively small.

  4. Ecological roles of dominant and rare prokaryotes in acid mine drainage revealed by metagenomics and metatranscriptomics

    SciTech Connect

    Hua, Zheng-Shuang; Han, Yu-Jiao; Chen, Lin-Xing; Liu, Jun; Hu, Min; Li, Sheng-Jin; Kuang, Jia-Liang; Chain, Patrick SG; Huang, Li-Nan; Shu, Wen-Sheng

    2014-11-07

    Here we report that high-throughput sequencing is expanding our knowledge of microbial diversity in the environment. Still, understanding the metabolic potentials and ecological roles of rare and uncultured microbes in natural communities remains a major challenge. To this end, we applied a ‘divide and conquer’ strategy that partitioned a massive metagenomic data set (>100 Gbp) into subsets based on K-mer frequency in sequence assembly to a low-diversity acid mine drainage (AMD) microbial community and, by integrating with an additional metatranscriptomic assembly, successfully obtained 11 draft genomes most of which represent yet uncultured and/or rare taxa (relative abundance <1%). We report the first genome of a naturally occurring Ferrovum population (relative abundance >90%) and its metabolic potentials and gene expression profile, providing initial molecular insights into the ecological role of these lesser known, but potentially important, microorganisms in the AMD environment. Gene transcriptional analysis of the active taxa revealed major metabolic capabilities executed in situ, including carbon- and nitrogen-related metabolisms associated with syntrophic interactions, iron and sulfur oxidation, which are key in energy conservation and AMD generation, and the mechanisms of adaptation and response to the environmental stresses (heavy metals, low pH and oxidative stress). Remarkably, nitrogen fixation and sulfur oxidation were performed by the rare taxa, indicating their critical roles in the overall functioning and assembly of the AMD community. Finally, our study demonstrates the potential of the ‘divide and conquer’ strategy in high-throughput sequencing data assembly for genome reconstruction and functional partitioning analysis of both dominant and rare species in natural microbial assemblages.

  5. Macroscopic to microscopic studies of flue gas desulfurization byproducts for acid mine drainage mitigation

    SciTech Connect

    Robbins, E.I.; Kalyoncu, R.S.; Finkelman, R.B.; Matos, G.R.; Barsotti, A.F.; Haefner, R.J.; Rowe, G.L. Jr.; Savela, C.E.; Eddy, J.I.

    1996-12-31

    The use of flue gas desulfurization (FGD) systems to reduce SO{sub 2} emissions has resulted in the generation of large quantities of byproducts. These and other byproducts are being stockpiled at the very time that alkaline materials having high neutralization potential are needed to mitigate acid mine drainage (AMD). FGD byproducts are highly alkaline materials composed primarily of unreacted sorbents (lime or limestone and sulfates and sulfites of Ca). The American Coal Ash Association estimated that approximately 20 million tons of FGD material were generated by electric power utilities equipped with wet lime-limestone PGD systems in 1993. Less than 5% of this material has been put to beneficial use for agricultural soil amendments and for the production of wallboard and cement. Four USGS projects are examining FGD byproduct use to address these concerns. These projects involve (1) calculating the volume of flue gas desulfurization (FGD) byproduct generation and their geographic locations in relation to AMD, (2) determining byproduct chemistry and mineralogy, (3) evaluating hydrology and geochemistry of atmospheric fluidized bed combustion byproduct as soil amendment in Ohio, and (4) analyzing microbial degradation of gypsum in anoxic limestone drains in West Virginia.

  6. Analysis of Biogeochemistry of Acid-Mine Drainage at Rowe, Massachusetts

    NASA Astrophysics Data System (ADS)

    Ahlfeld, D. P.; Yuretich, R.; Ergas, S.; Nusslein, K.; Feldman, A.

    2003-12-01

    Acid waters rich in iron and sulfate can support a wide variety of microorganisms that catalyze the oxidation-reduction reactions of these bioactive elements, exemplified by acid-mine drainage (AMD). In order to study the biogeochemistry of natural attenuation a field site has been established at Davis Mine, an abandoned pyrite mine in rural Rowe Massachusetts. This site is of particular interest because of the apparent dynamic equilibrium that has restricted the extent of the AMD in this area since the mine was closed nearly 100 years ago. Initial evidence suggests that sulfate reduction is occurring at the fringes of the site. Multi-level monitoring wells and surface water sampling points have been installed. Soil samples collected from the drilled wells are being used to provide inoculums for cultivating bacteria and identifying DNA. Preliminary data indicate a restricted lens of impacted groundwater that moves rapidly through the mine tailings and shallow bedrock fractures, but is contained by ambient groundwater from uncontaminated recharge areas. Sulfate reduction has been documented at the margins of the acid-generating area, and this has been reproduced in laboratory experiments. Current research is now examining the processes of Fe(III) and SO4 reduction and the roles of acidophilic and acid-tolerant anaerobic microorganisms. K12 teachers are part of the research teams and the effects of research experiences on their higher-level understanding of science are being evaluated.

  7. Preparation of metal-resistant immobilized sulfate reducing bacteria beads for acid mine drainage treatment.

    PubMed

    Zhang, Mingliang; Wang, Haixia; Han, Xuemei

    2016-07-01

    Novel immobilized sulfate-reducing bacteria (SRB) beads were prepared for the treatment of synthetic acid mine drainage (AMD) containing high concentrations of Fe, Cu, Cd and Zn using up-flow anaerobic packed-bed bioreactor. The tolerance of immobilized SRB beads to heavy metals was significantly enhanced compared with that of suspended SRB. High removal efficiencies of sulfate (61-88%) and heavy metals (>99.9%) as well as slightly alkaline effluent pH (7.3-7.8) were achieved when the bioreactor was fed with acidic influent (pH 2.7) containing high concentrations of multiple metals (Fe 469 mg/L, Cu 88 mg/L, Cd 92 mg/L and Zn 128 mg/L), which showed that the bioreactor filled with immobilized SRB beads had tolerance to AMD containing high concentrations of heavy metals. Partially decomposed maize straw was a carbon source and stabilizing agent in the initial phase of bioreactor operation but later had to be supplemented by a soluble carbon source such as sodium lactate. The microbial community in the bioreactor was characterized by denaturing gradient gel electrophoresis (DGGE) and sequencing of partial 16S rDNA genes. Synergistic interaction between SRB (Desulfovibrio desulfuricans) and co-existing fermentative bacteria could be the key factor for the utilization of complex organic substrate (maize straw) as carbon and nutrients source for sulfate reduction. PMID:27058913

  8. Selective recovery of Cu, Zn, and Ni from acid mine drainage.

    PubMed

    Park, Sang-Min; Yoo, Jong-Chan; Ji, Sang-Woo; Yang, Jung-Seok; Baek, Kitae

    2013-12-01

    In Korea, the heavy metal pollution from about 1,000 abandoned mines has been a serious environmental issue. Especially, the surface waters, groundwaters, and soils around mines have been contaminated by heavy metals originating from acid mine drainage (AMD) and mine tailings. So far, AMD was considered as a waste stream to be treated to prevent environmental pollutions; however, the stream contains mainly Fe and Al and valuable metals such as Ni, Zn, and Cu. In this study, Visual MINTEQ simulation was carried out to investigate the speciation of heavy metals as functions of pH and neutralizing agents. Based on the simulation, selective pH values were determined to form hydroxide or carbonate precipitates of Cu, Zn, and Ni. Experiments based on the simulation results show that the recovery yield of Zn and Cu were 91 and 94 %, respectively, in a binary mixture of Cu and Zn, while 95 % of Cu and 94 % of Ni were recovered in a binary mixture of Cu and Ni. However, the recovery yield and purity of Zn and Ni were very low because of similar characteristics of Zn and Ni. Therefore, the mixture of Cu and Zn or Cu and Ni could be recovered by selective precipitation via pH adjustment; however, it is impossible to recover selectively Zn and Ni in the mixture of them. PMID:23754100

  9. Acid mine drainage from the Panasqueira mine and its influence on Zêzere river (Central Portugal)

    NASA Astrophysics Data System (ADS)

    Candeias, Carla; Ávila, Paula Freire; Ferreira da Silva, Eduardo; Ferreira, Adelaide; Salgueiro, Ana Rita; Teixeira, João Paulo

    2014-11-01

    The Panasqueira hydrothermal mineralization, located in central Portugal, is the biggest Sn-W deposit of the Western Europe. The main evidences of the mining exploitation and ore treatment operations are testified with huge tailings, mainly, in the Rio and Barroca Grande areas. The mining and beneficiation processes, at the site, produces metal rich mine wastes. Oxidation of sulfides tailings and flow from open impoundments are responsible for the mobilization and migration of metals from the mine wastes into the environment. Acid mine drainage (AMD) discharged from Rio tailing has a pH around 3 and high metal concentrations. In Zêzere river, Fe and As are the most rapidly depleted downstream from AMD once As adsorbs, coprecipitate and form compounds with iron oxyhydroxides. The Zêzere river waters are oversaturated with respect to kaolinite and goethite and ferrihydrite can precipitate on stream with a near-neutral pH. At sites having low pH the dissolved Fe species in the water, mainly, occur as sulfate complexes due to a high SO4 concentration. Melanterite (Fe2+(SO4)·7(H2O)) and minor amounts of rozenite (Fe2+(SO4)·4(H2O)) and szomolnokite (Fe2+(SO4)·(H2O)) were observed on Rio tailing basement.

  10. Recovery of calcium carbonate from steelmaking slag and utilization for acid mine drainage pre-treatment.

    PubMed

    Mulopo, J; Mashego, M; Zvimba, J N

    2012-01-01

    The conversion of steelmaking slag (a waste product of the steelmaking process) to calcium carbonate (CaCO(3)) was tested using hydrochloric acid, ammonium hydroxide and carbon dioxide via a pH-swing process. Batch reactors were used to assess the technical feasibility of calcium carbonate recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effects of key process parameters, such as the amount of acid (HCl/calcium molar ratio), the pH and the CO(2) flow rate were considered. It was observed that calcium extraction from steelmaking slag significantly increased with an increase in the amount of hydrochloric acid. The CO(2) flow rate also had a positive effect on the carbonation reaction rate but did not affect the morphology of the calcium carbonate produced for values less than 2 L/min. The CaCO(3) recovered from the bench scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with the commercial laboratory grade CaCO(3). PMID:22643421

  11. Novel nickel resistance genes from the rhizosphere metagenome of plants adapted to acid mine drainage.

    PubMed

    Mirete, Salvador; de Figueras, Carolina G; González-Pastor, Jose E

    2007-10-01

    Metal resistance determinants have traditionally been found in cultivated bacteria. To search for genes involved in nickel resistance, we analyzed the bacterial community of the rhizosphere of Erica andevalensis, an endemic heather which grows at the banks of the Tinto River, a naturally metal-enriched and extremely acidic environment in southwestern Spain. 16S rRNA gene sequence analysis of rhizosphere DNA revealed the presence of members of five phylogenetic groups of Bacteria and the two main groups of Archaea mostly associated with sites impacted by acid mine drainage (AMD). The diversity observed and the presence of heavy metals in the rhizosphere led us to construct and screen five different metagenomic libraries hosted in Escherichia coli for searching novel nickel resistance determinants. A total of 13 positive clones were detected and analyzed. Insights about their possible mechanisms of resistance were obtained from cellular nickel content and sequence similarities. Two clones encoded putative ABC transporter components, and a novel mechanism of metal efflux is suggested. In addition, a nickel hyperaccumulation mechanism is proposed for a clone encoding a serine O-acetyltransferase. Five clones encoded proteins similar to well-characterized proteins but not previously reported to be related to nickel resistance, and the remaining six clones encoded hypothetical or conserved hypothetical proteins of uncertain functions. This is the first report documenting nickel resistance genes recovered from the metagenome of an AMD environment. PMID:17675438

  12. Bioremediation of acid mine drainage: an introduction to the Wheal Jane wetlands project.

    PubMed

    Whitehead, P G; Prior, H

    2005-02-01

    Acid mine drainage (AMD) is a widespread environmental problem associated with both working and abandoned mining operations. As part of an overall strategy to determine a long-term treatment option for AMD, a pilot passive treatment plant was constructed in 1994 at Wheal Jane Mine in Cornwall, UK. The plant consists of three separate systems; each containing aerobic reed beds, anaerobic cell and rock filters, and represents the largest European experimental facility of its kind. The systems only differ by the type of pre-treatment utilised to increase the pH of the influent minewater (pH<4): lime-dosed (LD), anoxic limestone drain (ALD) and lime free (LF), which receives no form of pre-treatment. The Wheal Jane pilot plant offered a unique facility and a major research project was established to evaluate the pilot plant and study in detail the biological mechanisms and the geochemical and physical processes that control passive treatment systems. The project has led to data, knowledge, models and design criteria for the future design, planning and sustainable management of passive treatment systems. A multidisciplinary team of scientists and managers from the U.K. universities, the Environment Agency and the Mining Industry has been put together to obtain the maximum advantage from the excellent facilities facility at Wheal Jane. PMID:15680623

  13. Amylases without known homologues discovered in an acid mine drainage: significance and impact

    PubMed Central

    Delavat, François; Phalip, Vincent; Forster, Anne; Plewniak, Frédéric; Lett, Marie-Claire; Lièvremont, Didier

    2012-01-01

    Acid Mine Drainages (AMDs) are extreme environments characterized by acidic and oligotrophic conditions and by metal contaminations. A function-based screening of an AMD-derived metagenomic library led to the discovery and partial characterization of two non-homologous endo-acting amylases sharing no sequence similarity with any known amylase nor glycosidase. None carried known amylolytic domains, nor could be assigned to any GH-family. One amylase displayed no similarity with any known protein, whereas the second one was similar to TraC proteins involved in the bacterial type IV secretion system. According to the scarce similarities with known proteins, 3D-structure modelling using I-TASSER was unsuccessful. This study underlined the utility of a function-driven metagenomic approach to obtain a clearer image of the bacterial community enzymatic landscape. More generally, this work points out that screening for microorganisms or biomolecules in a priori incongruous environments could provide unconventional and new exciting ways for bioprospecting. PMID:22482035

  14. Pilot test of pollution control and metal resource recovery for acid mine drainage.

    PubMed

    Yan, Bo; Mai, Ge; Chen, Tao; Lei, Chang; Xiao, Xianming

    2015-01-01

    The study was undertaken in order to recover the metal resources from acid mine drainage (AMD). A 300 m(3)/d continuous system was designed and fractional precipitation technology employed for the main metals Fe, Cu, Zn, and Mn recovery. The system was operated for six months using actual AMD in situ. The chemicals' input and also the retention time was optimized. Furthermore, the material balance was investigated. With the system, the heavy metals of the effluent after the Mn neutralization precipitation were below the threshold value of the Chinese integrated wastewater discharge limit. The precipitates generated contained 42%, 12%, 31%, and 18% for Fe, Cu, Zn, and Mn, respectively, and the recovery rates of Fe, Cu, Zn, and Mn were 82%, 79%, 83%, and 83%, respectively. The yield range of the precipitate had significant correlation with the influent metal content. Using the X-ray diffraction analysis, the refinement for Fe, Cu, and Zn could be achieved through the processes of roasting and floatation. Cost-benefit was also discussed; the benefit from the recycled metal was able to pay for the cost of chemical reagents used. Most important of all, through the use of this technology, the frustrating sludge problems were solved. PMID:26676020

  15. Field rates for natural attenuation of arsenic in Tinto Santa Rosa acid mine drainage (SW Spain).

    PubMed

    Asta, Maria P; Ayora, Carlos; Acero, Patricia; Cama, Jordi

    2010-05-15

    Reactive transport modelling of the main processes related to the arsenic natural attenuation observed in the acid mine drainage (AMD) impacted stream of Tinto Santa Rosa (SW Spain) was performed. Despite the simplicity of the kinetic expressions used to deal with arsenic attenuation processes, the model reproduced successfully the major chemical trends observed along the acid discharge. Results indicated that the rate of ferrous iron oxidation was similar to the one obtained in earlier field studies in which microbial catalysis is reported to occur. With regard to the scaled arsenic oxidation rate, it is one order of magnitude faster than the values obtained under laboratory conditions suggesting the existence of a catalytic agent in the natural system. Schwertmannite precipitation rate, which was represented by a simple kinetic expression relying on Fe(III) and pH, was in the range calculated for other AMD impacted sites. Finally, the obtained distribution coefficients used for representing arsenic sorption onto Fe(III) precipitates were lower than those deduced from reported laboratory data. This discrepancy is attributed to a decrease in the schwertmannite arsenate sorption capacity as sulphate increases in the solution. PMID:20153577

  16. Use of natural and applied tracers to guide targeted remediation efforts in an acid mine drainage system, Colorado Rockies, USA

    USGS Publications Warehouse

    Cowie, Rory; Williams, Mark W.; Wireman, Mike; Runkel, Robert L.

    2014-01-01

    Stream water quality in areas of the western United States continues to be degraded by acid mine drainage (AMD), a legacy of hard-rock mining. The Rico-Argentine Mine in southwestern Colorado consists of complex multiple-level mine workings connected to a drainage tunnel discharging AMD to passive treatment ponds that discharge to the Dolores River. The mine workings are excavated into the hillslope on either side of a tributary stream with workings passing directly under the stream channel. There is a need to define hydrologic connections between surface water, groundwater, and mine workings to understand the source of both water and contaminants in the drainage tunnel discharge. Source identification will allow targeted remediation strategies to be developed. To identify hydrologic connections we employed a combination of natural and applied tracers including isotopes, ionic tracers, and fluorescent dyes. Stable water isotopes (δ18O/δD) show a well-mixed hydrological system, while tritium levels in mine waters indicate a fast flow-through system with mean residence times of years not decades or longer. Addition of multiple independent tracers indicated that water is traveling through mine workings with minimal obstructions. The results from a simultaneous salt and dye tracer application demonstrated that both tracer types can be successfully used in acidic mine water conditions.

  17. Treatment of Selenium and Nitrate in Acid Mine Drainage: A Column Study

    NASA Astrophysics Data System (ADS)

    An, H.; Jeen, S. W.

    2015-12-01

    Treatment efficiency of selenium and nitrate in acid mine drainage (AMD) by two types of reactive mixtures, i.e., organic carbon-limestone (OC-LS) and organic carbon-zero valent iron (OC-ZVI), was evaluated through column experiments. The influent AMD, collected at an abandoned metal mine site in Korea, had pH of 2.9 and contained 1600 mg/ L of SO42- and elevated concentrations of metals (e.g., Al, Cd, Co, Cu, Fe, Zn). Selenium (40 mg/L) and nitrate (100 mg/L as NO3-N initially and 10 mg/L as NO3-N after 55 days) were spiked into the AMD. The columns were operated for a total of 90 days. The results showed the increase of pH from 2.9 to 7.0 and the decreases in concentrations of most of major ions including selenium and nitrate in both the OC-LS and OC-ZVI columns. The OC-ZVI column had higher removal rates of selenium and nitrate and created a more reduced environment than the OC-LS column due to the abiotic reactions of ZVI. However, a notable amount of ammonia was produced as a reaction product in the OC-ZVI column, while the OC-LS produced a minimum amount of ammonia, suggesting formation of N2 by denitrification. In both columns, removal rates of selenium were substantially increased when the influent NO3-N concentration was changed from 100 mg/L to 10 mg/L. Sulfate was reduced as much as 390 mg/L, as indicated by detection of hydrogen sulfide. The reduction of most metals is considered to be due to precipitation of metal-containing secondary minerals (e.g., sulfides, hydroxides, carbonates). This study shows that treatment of selenium and nitrate in AMD can be achievable using organic carbon-based reactive mixtures through reduction of selenium and nitrate. However, the use of ZVI is not recommended when selenium and nitrate coexist in AMD because of production of ammonia by abiotic reaction between ZVI and nitrate. This study also shows that concentration of nitrate in AMD is an important factor to determine the rate of selenium removal.

  18. Colloidal precipitates related to Acid Mine Drainage: bacterial diversity and micro fungi-heavy metal interactions

    NASA Astrophysics Data System (ADS)

    Lucchetti, G.; Carbone, C.; Consani, S.; Zotti, M.; Di Piazza, S.; Pozzolini, M.; Giovine, M.

    2015-12-01

    In Acid Mine Drainage (AMD) settings colloidal precipitates control the mobility of Potential Toxic Elements (PTEs). Mineral-contaminant relationships (i.e. adsorption, ion-exchange, desorption) are rarely pure abiotic processes. Microbes, mainly bacteria and microfungi, can catalyze several reactions modifying the element speciation, as well as the bioavailability of inorganic pollutants. Soil, sediments, and waters heavily polluted with PTEs through AMD processes are a potential reservoir of extremophile bacteria and fungi exploitable for biotechnological purposes. Two different AMD related colloids, an ochraceous precipitate (deposited in weakly acidic conditions, composed by nanocrystalline goethite) and a greenish-blue precipitate (deposited at near-neutral pH, composed by allophane + woodwardite) were sampled. The aims of this work were to a) characterize the mycobiota present in these colloidal minerals by evaluating the presence of alive fungal propagules and extracting bacteria DNA; b) verify the fungal strains tolerance, and bioaccumulation capability on greenish-blue and ZnSO4 enriched media; c) evaluate potential impact of bacteria in the system geochemistry. The preliminary results show an interesting and selected mycobiota able to survive under unfavourable environmental conditions. A significant number of fungal strains were isolated in pure culture. Among them, species belonging to Penicillium and Trichoderma genera were tested on both greenish-blue and ZnSO4 enriched media. The results show a significant tolerance and bioaccumulation capability to some PTEs. The same colloidal precipitates were processed to extract bacteria DNA by using a specific procedure developed for sediments. The results give a good yield of nucleic acids and a positive PCR amplification of 16S rDNA accomplished the first step for future metagenomic analyses.

  19. Passive treatment of acid mine drainage with high metal concentrations using dispersed alkaline substrate.

    PubMed

    Rötting, Tobias S; Thomas, Robert C; Ayora, Carlos; Carrera, Jesús

    2008-01-01

    Passive treatment systems based on the dissolution of coarse calcite grains are widely used to remediate acid mine drainage (AMD). Unfortunately, they tolerate only low metal concentrations or acidity loads, because they are prone to passivation (loss of reactivity due to coating) and/or clogging (loss of permeability) by precipitates. To overcome these problems, a dispersed alkaline substrate (DAS) composed of a fine-grained alkaline reagent (calcite sand) mixed with a coarse inert matrix (wood chips) was developed. The small grains provide a large reactive surface and dissolve almost completely before the growing layer of precipitates passivates the substrate, whereas the dispersion of nuclei for precipitation on the inert surfaces retards clogging. Chemical and hydraulic performance of DAS was investigated in two laboratory columns fed at different flow rates with natural AMD of pH 2.3 to 3.5 and inflow net acidity 1350 to 2300 mg/L as CaCO(3). The DAS columns removed 900 to 1600 mg/L net acidity, 3 to 4.5 times more than conventional passive treatment systems. Regardless of the flow rate employed, Al, Fe(III), Cu, and Pb were virtually eliminated. Minor Zn, Ni, and Cd were removed at low flow rates. High acidity removal is possible because these metals accumulate intentionally in DAS, and their precipitation promotes further calcite dissolution. During 15 mo, DAS operated without clogging at 120 g acidity/m(2).d, four times the loading rate recommended for conventional passive systems; DAS may therefore be capable of treating AMD at sites where influent chemistry precludes the use of other passive systems. PMID:18689735

  20. Predicting taxonomic and functional structure of microbial communities in acid mine drainage.

    PubMed

    Kuang, Jialiang; Huang, Linan; He, Zhili; Chen, Linxing; Hua, Zhengshuang; Jia, Pu; Li, Shengjin; Liu, Jun; Li, Jintian; Zhou, Jizhong; Shu, Wensheng

    2016-06-01

    Predicting the dynamics of community composition and functional attributes responding to environmental changes is an essential goal in community ecology but remains a major challenge, particularly in microbial ecology. Here, by targeting a model system with low species richness, we explore the spatial distribution of taxonomic and functional structure of 40 acid mine drainage (AMD) microbial communities across Southeast China profiled by 16S ribosomal RNA pyrosequencing and a comprehensive microarray (GeoChip). Similar environmentally dependent patterns of dominant microbial lineages and key functional genes were observed regardless of the large-scale geographical isolation. Functional and phylogenetic β-diversities were significantly correlated, whereas functional metabolic potentials were strongly influenced by environmental conditions and community taxonomic structure. Using advanced modeling approaches based on artificial neural networks, we successfully predicted the taxonomic and functional dynamics with significantly higher prediction accuracies of metabolic potentials (average Bray-Curtis similarity 87.8) as compared with relative microbial abundances (similarity 66.8), implying that natural AMD microbial assemblages may be better predicted at the functional genes level rather than at taxonomic level. Furthermore, relative metabolic potentials of genes involved in many key ecological functions (for example, nitrogen and phosphate utilization, metals resistance and stress response) were extrapolated to increase under more acidic and metal-rich conditions, indicating a critical strategy of stress adaptation in these extraordinary communities. Collectively, our findings indicate that natural selection rather than geographic distance has a more crucial role in shaping the taxonomic and functional patterns of AMD microbial community that readily predicted by modeling methods and suggest that the model-based approach is essential to better understand natural

  1. Acid mine drainage in the Iberian Pyrite Belt: 2. Lessons learned from recent passive remediation experiences.

    PubMed

    Ayora, Carlos; Caraballo, Manuel A; Macias, Francisco; Rötting, Tobias S; Carrera, Jesús; Nieto, Jose-Miguel

    2013-11-01

    The Iberian Pyrite Belt (IPB), SW Spain and Portugal, contains about 100 abandoned mine wastes and galleries that release acid mine drainages (AMD) to the Tinto and Odiel rivers. In situ passive remediation technologies are especially suitable to remediate the drainages of these orphan sites. However, traditional remediation systems, designed for coal mines, have been demonstrated inefficient to treat the IPB mine waters. Due to their high acidity and metal loads, large amount of solids precipitate and fast clogging of porosity or passivation (coating) of the reactive grains occurs. To overcome these problems, the dispersed alkaline substrate (DAS) a mixture of fine-grained limestone sand and a coarse inert matrix (e.g., wood shavings) was developed. The small grains provide a large reactive surface and dissolve almost completely before the growing layer of precipitates passivates the substrate. The high porosity retards clogging. However, calcite dissolution only raises pH to values around 6.5, at which the hydroxides of trivalent metals (Al and Fe) precipitate, but it is not high enough to remove divalent metals. Caustic magnesia (MgO) buffers the solution pH between 8.5 and 10. A DAS system replacing limestone with caustic magnesia has been tested to be very efficient to remove divalent metals (Zn, Cd, Mn, Cu, Co, Ni, and Pb) from the water previously treated with calcite. PMID:23508532

  2. The status of the passive treatment systems for acid mine drainage in South Korea

    NASA Astrophysics Data System (ADS)

    Ji, Sangwoo; Kim, Sunjoon; Ko, Juin

    2008-09-01

    This study was performed to investigate the operating status, evaluate the problems, and discuss possible improvement methods of passive treatment systems for acid mine drainage (AMD) in South Korea. Thirty-five passive treatment systems in 29 mines have been constructed from 1996 to 2002 using successive alkalinity producing systems (SAPS) as the main treatment process. We investigated 29 systems (two for metal mines), 19 of which revealed various problems. Overflows of drainage from SAPS, wetland, or oxidation ponds were caused by the flow rate exceeding the capacities of the facilities or by the reduced permeability of the organic substance layer. Leakages occurred at various parts of the systems. In some cases, clogged and broken pipes at the mouths of the mine adits made the whole system unusable. Some systems showed very low efficiencies without apparent leakage or overflow. Even though the systems showed fairly good efficiencies in metal removal ratios (mainly iron) and pH control; sulfate removal rates were very poor except in three systems, which may indicate very poor sulfate reductions with sulfate reducing bacteria (SRB) as a means.

  3. Recovery of calcium carbonate from waste gypsum and utilization for remediation of acid mine drainage from coal mines.

    PubMed

    Mulopo, J; Radebe, V

    2012-01-01

    The recovery of calcium carbonate from waste gypsum (a waste product of the reverse osmosis (RO) desalination process) was tested using sodium carbonate. Batch recovery of calcium carbonate from waste gypsum slurries by reacting with sodium carbonate under ambient conditions was used to assess the technical feasibility of CaCO(3) recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effect of key process parameters, such as the slurry concentration (%) and the molar ratio of sodium carbonate to gypsum were considered. It was observed that batch waste gypsum conversion significantly increased with decrease in the slurry concentration or increase in the molar ratio of sodium carbonate to gypsum. The CaCO(3) recovered from the bench-scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with commercial laboratory grade CaCO(3). PMID:22828309

  4. Organic substrates as electron donors in permeable reactive barriers for removal of heavy metals from acid mine drainage.

    PubMed

    Kijjanapanich, P; Pakdeerattanamint, K; Lens, P N L; Annachhatre, A P

    2012-12-01

    This research was conducted to select suitable natural organic substrates as potential carbon sources for use as electron donors for biological sulphate reduction in a permeable reactive barrier (PRB). A number of organic substrates were assessed through batch and continuous column experiments under anaerobic conditions with acid mine drainage (AMD) obtained from an abandoned lignite coal mine. To keep the heavy metal concentration at a constant level, the AMD was supplemented with heavy metals whenever necessary. Under anaerobic conditions, sulphate-reducing bacteria (SRB) converted sulphate into sulphide using the organic substrates as electron donors. The sulphide that was generated precipitated heavy metals as metal sulphides. Organic substrates, which yielded the highest sulphate reduction in batch tests, were selected for continuous column experiments which lasted over 200 days. A mixture of pig-farm wastewater treatment sludge, rice husk and coconut husk chips yielded the best heavy metal (Fe, Cu, Zn and Mn) removal efficiencies of over 90%. PMID:23437664

  5. The ecotoxicological recovery of Ely Creek and tributaries (Lee County, VA) after remediation of acid mine drainage.

    PubMed

    Simon, Mathew L; Cherry, Donald S; Currie, Rebecca J; Zipper, Carl E

    2012-04-01

    The Ely Creek watershed (Lee County, VA) was determined in 1995 to be the most negatively affected by acid mine drainage (AMD) within the Virginia coalfield. This determination led the US Army Corps of Engineers to design and build passive wetland remediation systems at two major AMD seeps affecting Ely Creek. This study was undertaken to determine if ecological recovery had occurred in Ely Creek. The results indicate that remediation had a positive effect on all monitoring sites downstream of the remediated AMD seeps. At the site most impacted by AMD, mean pH was 2.93 prior to remediation and improved to 7.14 in 2004. Benthic macroinvertebrate surveys revealed that one AMD influenced site had increased taxa richness from zero taxa in 1997 to 24 in 2004. While in situ testing of Asian clams resulted in zero survival at five of seven AMD influenced sites prior to remediation, some clams survived at all sites after. Clam survival was found to be significantly less than upstream references at only two sites, both downstream of un-mitigated AMD seeps in 2004. An ecotoxicological rating (ETR) system that combined ten biotic and abiotic parameters was developed as an indicator of the ecological status for each study site. A comparison of ETRs from before and after remediation demonstrated that all sites downstream of the remediation had experienced some level of recovery. Although the remediation has improved the ecological health of Ely Creek, un-mitigated AMD discharges are still negatively impacting the watershed. PMID:22371009

  6. The ecotoxicological recovery of Ely Creek and tributaries (Lee County, VA) after remediation of acid mine drainage.

    PubMed

    Simon, Matthew L; Cherry, Donald S; Currie, Rebecca J; Zipper, Carl E

    2006-12-01

    The Ely Creek watershed (Lee County, VA) was determined in 1995 to be the most negatively affected by acid mine drainage (AMD) within the Virginia coalfield. This determination led the US Army Corps of Engineers to design and build passive wetland remediation systems at two major AMD seeps affecting Ely Creek. This study was undertaken to determine if ecological recovery had occurred in Ely Creek. The results indicate that remediation had a positive effect on all monitoring sites downstream of the remediated AMD seeps. At the site most impacted by AMD, mean pH was 2.93 prior to remediation and improved to 7.14 in 2004. Benthic macroinvertebrate surveys revealed that one AMD influenced site had increased taxa richness from zero taxa in 1997 to 24 in 2004. While in situ testing of Asian clams resulted in zero survival at five of seven AMD influenced sites prior to remediation, some clams survived at all sites after. Clam survival was found to be significantly less than upstream references at only two sites, both downstream of un-mitigated AMD seeps in 2004. An ecotoxicological rating (ETR) system that combined ten biotic and abiotic parameters was developed as an indicator of the ecological status for each study site. A comparison of ETRs from before and after remediation demonstrated that all sites downstream of the remediation had experienced some level of recovery. Although the remediation has improved the ecological health of Ely Creek, un-mitigated AMD discharges are still negatively impacting the watershed. PMID:16770499

  7. Simulation of acid mine drainage generation around Küre VMS Deposits, Northern Turkey

    NASA Astrophysics Data System (ADS)

    Demirel, Cansu; Kurt, Mehmet Ali; Çelik Balci, Nurgül

    2015-04-01

    This study investigated comparative leaching characteristics of acidophilic bacterial strains under shifting environmental conditions at proposed two stages as formation stage or post acidic mine drainage (AMD) generation. At the first stage, initial reactions associated with AMD generation was simulated in shaking flasks containing massive pyritic chalcopyrite ore by using a pure strain Acidithiobacillus ferrooxidans and a mixed culture of Acidithiobacillus sp. mostly dominated by A. ferrooxidans and A. thiooxidans at 26oC. At the second stage, long term bioleaching experiments were carried out with the same strains at 26oC and 40oC to investigate the leaching characteristics of pyritic chalcopyrite ore under elevated heavy metal and temperature conditions. During the experiments, physicochemical characteristics (e.i. Eh, pH, EC) metal (Fe, Co, Cu, Zn) and sulfate concentration of the experimental solution were monitored during 180 days. Significant acid generation and sulfate release were determined during bioleaching of the ore by mixed acidophilic cultures containing both iron and sulfur oxidizers. In the early stage of the experiments, heavy metal release from the ore was caused by generation of acid due to accelerated bacterial oxidation of the ore. Generally high concentrations of Co and Cu were released into the solution from the experiments conducted by pure cultures of Acidithiobacillus ferrooxidans whereas high Zn and Fe was released into the solution from the mixed culture experiments. In the later stage of AMD generation and post AMD, chemical oxidation is accelerated causing excessive amounts of contamination, even exceeding the amounts resulted from bacterial oxidation by mixed cultures. Acidithibacillus ferrooxidans was found to be more effective in leaching Cu, Fe and Co at higher temperatures in contrary to mixed acidophiles that are more prone to operate at optimal moderate conditions. Moreover, decreasing Fe values are noted in bioleaching

  8. Microbial Communities and a Novel Symbiotic Interaction in Extremely Acidic Mine Drainage at Iron Mountain, California

    NASA Astrophysics Data System (ADS)

    Baker, B. J.; Banfield, J. F.

    2002-12-01

    Culture-independent studies of microbial communities in the acid mine drainage (AMD) system associated with the Richmond ore body at Iron Mountain, CA, demonstrated that the total number of prokaryote lineages is small compared to other environments. Phylogenetic analyses of 232 small subunit ribosomal RNA (rRNA) genes from six clone libraries revealed some novel lines of descent. Many of the novel clones were from libraries constructed from subaerial biofilms associated with fine grained pyrite. The clones form several distinct groups within the order Thermoplasmatales and are most closely related to Ferroplasma spp. and Thermoplasma spp. Another novel group detected in a pH 1.4 pool and a pH 0.8 biofilm falls within the Rickettsiales (alpha-proteobacteria and related to mitochondria) and is most closely related to a-proteobacterial endosymbionts of Acanthamoeba spp. An oligonucleotide rRNA probe designed to target alpha-proteobacteria revealed that these are protist endosymbionts, and that they are associated with a small percentage (2%) of the total eukaryotes in samples from the Richmond mine. Measurements of the internal pH of these protists show that their cytosol is close to neutral. Thus, protists provide a habitat within the AMD system that is at least 5 pH units less acidic than the surroundings. The uncultured AMD endosymbionts have a conserved 273 nucleotide intervening sequence (IVS) in the variable V1 region of their 16S rRNA gene. The IVS does not match any sequence in current databases, but predicted secondary structure form well defined stem loops. The discovery of inserts within a highly conserved gene is extremely rare. At present we have not identified the protist host. However, it is interesting to note that protists previously shown to have a-proteobacterial endosymbionts possess 18S rRNA genes that contain both IVSs and group I introns. The possibility that the IVS in the AMD bacteria is a result of extensive genetic exchange between a

  9. Efficacy assessment of acid mine drainage treatment with coal mining waste using Allium cepa L. as a bioindicator.

    PubMed

    Geremias, Reginaldo; Bortolotto, Tiago; Wilhelm-Filho, Danilo; Pedrosa, Rozangela Curi; de Fávere, Valfredo Tadeu

    2012-05-01

    The aim of this study was to evaluate the efficacy of the treatment of acid mine drainage (AMD) with calcinated coal mining waste using Allium cepa L. as a bioindicator. The pH values and the concentrations of aluminum, iron, manganese, zinc, copper, lead and sulfate were determined before and after the treatment of the AMD with calcinated coal mining waste. Allium cepa L. was exposed to untreated and treated AMD, as well as to mineral water as a negative control (NC). At the end of the exposure period, the inhibition of root growth was measured and the mean effective concentration (EC(50)) was determined. Oxidative stress biomarkers such as lipid peroxidation (TBARS), protein carbonyls (PC), catalase activity (CAT) and reduced glutathione levels (GSH) in the fleshy leaves of the bulb, as well as the DNA damage index (ID) in meristematic cells, were evaluated. The results indicated that the AMD treatment with calcinated coal mining waste resulted in an increase in the pH and an expressive removal of aluminum, iron, manganese and zinc. A high sub-chronic toxicity was observed when Allium cepa L. was exposed to the untreated AMD. However, after the treatment no toxicity was detected. Levels of TBARS and PC, CAT activity and the DNA damage index were significantly increased (P<0.05) in Allium cepa L. exposed to untreated AMD when compared to treated AMD and also to negative controls. No significant alteration in the GSH content was observed. In conclusion, the use of calcinated coal mining waste associated with toxicological tests on Allium cepa L. represents an alternative system for the treatment and biomonitoring of these types of environmental contaminants. PMID:22239909

  10. Investigating the Copper Isotope Composition of Red Mountain Creek: a Stream Affected by Acid Mine Drainage

    NASA Astrophysics Data System (ADS)

    Kimball, B. E.; Mathur, R.; Brantley, S. L.; Vervoort, J. D.

    2005-12-01

    Understanding the sources of metals and the processes that affect their transport in watersheds affected by acid mine drainage (AMD) is central to improving stream water quality. Using a new technique to address an old problem, we measured the 65Cu/63Cu ratios in filtered (pore size = 0.45μm or 0.22μm) and unfiltered samples of AMD-impacted streamwater collected during low-flow conditions from Red Mountain Creek near Silverton, Colorado. Red Mountain Creek is a small mountain stream receiving metal-rich, acidic drainage from acid-sulfate and quartz-sericite-pyrite alteration zones within dacitic-andesitic lavas and volcaniclastic sediments. We measured δ65Cu values [where δ65Cu = ((65Cu/63Cusample/65Cu/63Custandard) - 1) × 103] on a multi-collector inductively coupled plasma mass spectrometer; instrumental mass bias was corrected by doping with the Johnson-Mattey Zn solution and bracketing with the NIST976 standard. All samples are enriched in 65Cu, with δ65Cu values ranging from 1.03 ± 0.10‰ to 3.76 ± 0.10‰ (2σ). Higher values correspond to an inflow emanating from a mineshaft that shows the highest Cu concentration (10.4 mg/L). As Cu becomes less concentrated downstream, the δ65Cu values generally decrease. At two of the three sample locations, the filtered samples are more enriched in 65Cu than the unfiltered samples, which contain suspended precipitates. These results are consistent with previous batch-leach experiments showing that during dissolution of chalcopyrite (CuFeS2) and chalcocite (Cu2S) (with and without Acidithiobacillus ferrooxidans), Cu released into solution by leaching was enriched in 65Cu and Cu precipitates were depleted relative to the starting sulfide minerals. This fractionation may indicate that biotic (e.g., microbial metabolism) and/or abiotic processes (e.g., metal sorption and mineral precipitation) induce isotope effects during Cu partitioning. Future measurements of 65Cu/63Cu ratios in primary Cu-sulfide minerals and

  11. Fungi contribute critical but spatially varying roles in nitrogen and carbon cycling in acid mine drainage

    DOE PAGESBeta

    Mosier, Annika C.; Miller, Christopher S.; Frischkorn, Kyle R.; Ohm, Robin A.; Li, Zhou; LaButti, Kurt; Lapidus, Alla; Lipzen, Anna; Chen, Cindy; Johnson, Jenifer; et al

    2016-03-03

    The ecosystem roles of fungi have been extensively studied by targeting one organism and/or biological process at a time, but the full metabolic potential of fungi has rarely been captured in an environmental context. We hypothesized that fungal genome sequences could be assembled directly from the environment using metagenomics and that transcriptomics and proteomics could simultaneously reveal metabolic differentiation across habitats. We reconstructed the near-complete 27 Mbp genome of a filamentous fungus, Acidomyces richmondensis, and evaluated transcript and protein expression in floating and streamer biofilms from an acid mine drainage (AMD) system. A. richmondensis transcripts involved in denitrification and inmore » the degradation of complex carbon sources (including cellulose) were up-regulated in floating biofilms, whereas central carbon metabolism and stress-related transcripts were significantly up-regulated in streamer biofilms. Finally, these findings suggest that the biofilm niches are distinguished by distinct carbon and nitrogen resource utilization, oxygen availability, and environmental challenges. An isolated A. richmondensis strain from this environment was used to validate the metagenomics-derived genome and confirm nitrous oxide production at pH 1. Overall, our analyses defined mechanisms of fungal adaptation and identified a functional shift related to different roles in carbon and nitrogen turnover for the same species of fungi growing in closely located but distinct biofilm niches.« less

  12. Fungi Contribute Critical but Spatially Varying Roles in Nitrogen and Carbon Cycling in Acid Mine Drainage

    PubMed Central

    Mosier, Annika C.; Miller, Christopher S.; Frischkorn, Kyle R.; Ohm, Robin A.; Li, Zhou; LaButti, Kurt; Lapidus, Alla; Lipzen, Anna; Chen, Cindy; Johnson, Jenifer; Lindquist, Erika A.; Pan, Chongle; Hettich, Robert L.; Grigoriev, Igor V.; Singer, Steven W.; Banfield, Jillian F.

    2016-01-01

    The ecosystem roles of fungi have been extensively studied by targeting one organism and/or biological process at a time, but the full metabolic potential of fungi has rarely been captured in an environmental context. We hypothesized that fungal genome sequences could be assembled directly from the environment using metagenomics and that transcriptomics and proteomics could simultaneously reveal metabolic differentiation across habitats. We reconstructed the near-complete 27 Mbp genome of a filamentous fungus, Acidomyces richmondensis, and evaluated transcript and protein expression in floating and streamer biofilms from an acid mine drainage (AMD) system. A. richmondensis transcripts involved in denitrification and in the degradation of complex carbon sources (including cellulose) were up-regulated in floating biofilms, whereas central carbon metabolism and stress-related transcripts were significantly up-regulated in streamer biofilms. These findings suggest that the biofilm niches are distinguished by distinct carbon and nitrogen resource utilization, oxygen availability, and environmental challenges. An isolated A. richmondensis strain from this environment was used to validate the metagenomics-derived genome and confirm nitrous oxide production at pH 1. Overall, our analyses defined mechanisms of fungal adaptation and identified a functional shift related to different roles in carbon and nitrogen turnover for the same species of fungi growing in closely located but distinct biofilm niches. PMID:26973616

  13. Fungi Contribute Critical but Spatially Varying Roles in Nitrogen and Carbon Cycling in Acid Mine Drainage.

    PubMed

    Mosier, Annika C; Miller, Christopher S; Frischkorn, Kyle R; Ohm, Robin A; Li, Zhou; LaButti, Kurt; Lapidus, Alla; Lipzen, Anna; Chen, Cindy; Johnson, Jenifer; Lindquist, Erika A; Pan, Chongle; Hettich, Robert L; Grigoriev, Igor V; Singer, Steven W; Banfield, Jillian F

    2016-01-01

    The ecosystem roles of fungi have been extensively studied by targeting one organism and/or biological process at a time, but the full metabolic potential of fungi has rarely been captured in an environmental context. We hypothesized that fungal genome sequences could be assembled directly from the environment using metagenomics and that transcriptomics and proteomics could simultaneously reveal metabolic differentiation across habitats. We reconstructed the near-complete 27 Mbp genome of a filamentous fungus, Acidomyces richmondensis, and evaluated transcript and protein expression in floating and streamer biofilms from an acid mine drainage (AMD) system. A. richmondensis transcripts involved in denitrification and in the degradation of complex carbon sources (including cellulose) were up-regulated in floating biofilms, whereas central carbon metabolism and stress-related transcripts were significantly up-regulated in streamer biofilms. These findings suggest that the biofilm niches are distinguished by distinct carbon and nitrogen resource utilization, oxygen availability, and environmental challenges. An isolated A. richmondensis strain from this environment was used to validate the metagenomics-derived genome and confirm nitrous oxide production at pH 1. Overall, our analyses defined mechanisms of fungal adaptation and identified a functional shift related to different roles in carbon and nitrogen turnover for the same species of fungi growing in closely located but distinct biofilm niches. PMID:26973616

  14. Heavy metal geochemistry of the acid mine drainage discharged from the Hejiacun uranium mine in central Hunan, China

    NASA Astrophysics Data System (ADS)

    Peng, Bo; Tang, Xiaoyan; Yu, Changxun; Xie, Shurong; Xiao, Meilian; Song, Zhi; Tu, Xianglin

    2009-03-01

    The acid mine drainage (AMD) discharged from the Hejiacun uranium mine in central Hunan (China) was sampled and analyzed using ICP-MS techniques. The analyzing results show that the AMD is characterized by the major ions FeTotal, Mn, Al and Si, and is concentrated with heavy metals and metalloids including Cd, Co, Ni, Zn, U, Cu, Pb, Tl, V, Cr, Se, As and Sb. During the AMD flowing downstream, the dissolved heavy metals were removed from the AMD waters through adsorption onto and co-precipitation with metal-oxhydroxides coated on the streambed. Among these metals, Cd, Co, Ni, Zn, U, Cu, Pb and Tl are negatively correlated to pH values, and positively correlated to major ions Fe, Al, Si, Mn, Mg, Ca and K. The metals/metalloids V, Cr, Se, As and Sb are conservative in the AMD solution, and negatively-correlated to major ions Na, Ca and Mg. Due to the above different behaviors of these chemical elements, the pH-negatively related metals (PM) and the conservative metals (CM) are identified; the PM metals include Cd, Co, Ni, Zn, U, Cu, Pb and Tl, and the CM metals V, Cr, Se, As and Sb. Based on understanding the geochemistry of PM and CM metals in the AMD waters, a new equation: EXT = (Acidity + PM)/pH + CM × pH, is proposed to estimate and evaluate extent of heavy-metal pollution (EXT) of AMD. The evaluation results show that the AMD and surface waters of the mine area have high EXT values, and they could be the potential source of heavy-metal contamination of the surrounding environment. Therefore, it is suggested that both the AMD and surface waters should be treated before they are drained out of the mine district, for which the traditional dilution and neutralization methods can be applied to remove the PM metals from the AMD waters, and new techniques through reducing the pH value of the downstream AMD waters should be developed for removal of the CM metals.

  15. Comparison of acid mine drainage microbial communities in physically and geochemically distinct ecosystems.

    PubMed

    Bond, P L; Druschel, G K; Banfield, J F

    2000-11-01

    This study presents population analyses of microbial communities inhabiting a site of extreme acid mine drainage (AMD) production. The site is the inactive underground Richmond mine at Iron Mountain, Calif., where the weathering of a massive sulfide ore body (mostly pyrite) produces solutions with pHs of approximately 0.5 to approximately 1.0. Here we used a suite of oligonucleotide probes, designed from molecular data recently acquired from the site, to analyze a number of microbial environments by fluorescent in situ hybridization. Microbial-community analyses were correlated with geochemical and mineralogical data from those environments. The environments investigated were within the ore body and thus at the site of pyrite dissolution, as opposed to environments that occur downstream of the dissolution. Few organism types, as defined by the specificities of the oligonucleotide probes, dominated the microbial communities. The majority of the dominant organisms detected were newly discovered or organisms only recently associated with acid-leaching environments. "Ferroplasma" spp. were detected in many of the communities and were particularly dominant in environments of lowest pH and highest ionic strength. Leptospirillum spp. were also detected in many slime and pyrite-dominated environments. In samples of an unusual subaerial slime, a new uncultured Leptospirillum sp. dominated. Sulfobacillus spp. were detected as a prominent inhabitant in warmer ( approximately 43 degrees C) environments. The information gathered here is critical for determining organisms important to AMD production at Iron Mountain and for directing future studies of this process. The findings presented here also have relevance to the microbiology of industrial bioleaching and to the understanding of geochemical iron and sulfur cycles. PMID:11055950

  16. Electrochemical treatment of acidic aqueous ferrous sulfate and copper sulfate as models for acid mine drainage.

    PubMed

    Bunce, N J; Chartrand, M; Keech, P

    2001-12-01

    Acid mine drainage (AMD) is a serious environmental problem in the mining industry. The present work describes electrolytic reduction of solutions of synthetic AMD, comprising FeSO4/H2SO4 and CuSO4/H2SO4, in flow-through cells whose anode and cathode compartments were separated using ion exchange membranes. In the case of FeSO4/H2SO4 at constant flow rate, the pH of the effluent from the catholyte increased progressively with current at a variety of cathodes, due to electrolytic reduction of H+ ions to elemental hydrogen. Near-quantitative removal of iron was achieved by sparging air into the catholyte effluent, thereby precipitating iron outside the electrochemical cell, and avoiding fouling of the electrodes. The anode reaction was the oxidation of water to O2, a proton-releasing process. Using cation exchange membranes and sodium sulfate as the supporting electrolyte in the anode compartment, the efficiency of the process was compromised at high currents by transport of H+ competitively with Na+ from the anode to the cathode compartments. Higher efficiencies were obtained when anion exchange membranes were used, and in this case no additional supporting electrolyte other than dilute H2SO4 was needed, the net reaction being the electrochemically driven transfer of the elements of H2SO4 from the cathode to the anode compartments. Current efficiencies approximately 50% were achieved, the loss of efficiency being accounted for by ohmic heating of the solutions. In the case of CuSO4/H2SO4 and anion exchange membranes at high currents, reduction of Cu2+ and H+ ions and transport of SO4(2-) ions out of the catholyte caused unacceptably high potentials to be generated. PMID:11763043

  17. The Wheal Jane wetlands model for bioremediation of acid mine drainage.

    PubMed

    Whitehead, P G; Cosby, B J; Prior, H

    2005-02-01

    Acid mine drainage (AMD) is a widespread environmental problem associated with both working and abandoned mining operations. As part of an overall strategy to determine a long-term treatment option for AMD, a pilot passive treatment plant was constructed in 1994 at Wheal Jane Mine in Cornwall, UK. The plant consists of three separate systems, each containing aerobic reed beds, anaerobic cell and rock filters, and represents the largest European experimental facility of its kind. The systems only differ by the type of pretreatment utilised to increase the pH of the influent minewater (pH <4): lime dosed (LD), anoxic limestone drain (ALD) and lime free (LF), which receives no form of pretreatment. Historical data (1994-1997) indicate median Fe reduction between 55% and 92%, sulphate removal in the range of 3-38% and removal of target metals (cadmium, copper and zinc) below detection limits, depending on pretreatment and flow rates through the system. A new model to simulate the processes and dynamics of the wetlands systems is described, as well as the application of the model to experimental data collected at the pilot plant. The model is process based, and utilises reaction kinetic approaches based on experimental microbial techniques rather than an equilibrium approach to metal precipitation. The model is dynamic and utilises numerical integration routines to solve a set of differential equations that describe the behaviour of 20 variables over the 17 pilot plant cells on a daily basis. The model outputs at each cell boundary are evaluated and compared with the measured data, and the model is demonstrated to provide a good representation of the complex behaviour of the wetland system for a wide range of variables. PMID:15680633

  18. Hydrogeochemical niches associated with hyporheic exchange beneath an acid mine drainage-contaminated stream

    NASA Astrophysics Data System (ADS)

    Larson, Lance N.; Fitzgerald, Michael; Singha, Kamini; Gooseff, Michael N.; Macalady, Jennifer L.; Burgos, William

    2013-09-01

    Biological low-pH Fe(II)-oxidation creates terraced iron formations (TIFs) that remove Fe(III) from solution. TIFs can be used for remediation of acid mine drainage (AMD), however, as sediment depth increases, Fe(III)-reduction in anoxic subsurface areas may compromise treatment effectiveness. In this study we used near-surface electrical resistivity imaging (ERI) and in situ pore-water samplers to spatially resolve bulk conductivity changes within a TIF formed in a stream emanating from a large abandoned deep clay mine in Cambria County, Pennsylvania, USA. Because of the high fluid electrical conductivity of the emergent AMD (1860 μS), fresh water (42 μS) was added as a dilution tracer to visualize the spatial and temporal extent of hyporheic exchange and to characterize subsurface flow paths. Distinct hydrogeochemical niches were identified in the shallow subsurface beneath the stream by overlaying relative groundwater velocities (derived from ERI) with pore-water chemistry profiles. Niches were classified based on relatively “fast” versus “slow” rates of hyporheic exchange and oxic versus anoxic conditions. Pore-water concentrations and speciation of iron, pH, and redox potential differed between subsurface flow regimes. The greatest extent of hyporheic exchange was beneath the center of the stream, where a shallower (<10 cm) Fe(II)-oxidizing zone was observed. Meanwhile, less hyporheic exchange was observed near the channel banks, concurrent with a more pronounced, deeper (>70 cm) Fe(II)-oxidizing zone. At these locations, relatively slower groundwater exchange may promote biotic Fe(II)-oxidation and improve the long-term stability of Fe sequestered in TIFs.

  19. Acute toxicity of an acid mine drainage mixing zone to juvenile bluegill and largemouth bass

    USGS Publications Warehouse

    Henry, T.B.; Irwin, E.R.; Grizzle, J.M.; Wildhaber, M.L.; Brumbaugh, W.G.

    1999-01-01

    The toxicity of an acid mixing zone produced at the confluence of a stream that was contaminated by acid mine drainage (AMD) and a pH-neutral stream was investigated in toxicity tests with juvenile bluegill Lepomis macrochirus and largemouth bass Micropterus salmoides. Fish mortalities in instream cages located in the mixing zone, below the mixing zone, and upstream in both tributaries were compared to determine relative toxicity at each site. In all tests and for both species, significantly higher mortality was observed in the mixing zone than at any other location, including the acid stream, which had lower pH (2.9-4.3). The mixing zone was defined chemically by rapid precipitation of dissolved aluminum and iron, which arrived from the low-pH stream, and by the presence of white precipitates, which were attached to the substratum and which extended below the confluence. Possible seasonal changes in mixing zone toxicity were investigated by conducting field tests with bluegill in June, July, and August 1996 and in January 1997 and by conducting field tests with largemouth bass in April and May 1997. Toxicity was not significantly different at the extremes of temperature, pH, and metal concentration that occurred in June and July, as compared with January. Toxicity was significantly lower in August; however, elevated stream discharge during the August test may have disturbed mixing zone characteristics. High toxicity in AMD mixing zones may lower the survival of fishes in streams, reduce available habitat, and impede movements of migratory fish.

  20. Microbial Biomass and Community Structure of a Stromatolite from an Acid Mine Drainage System in Western Indiana

    NASA Astrophysics Data System (ADS)

    Fang, J.; Hasiotis, S. T.; Das Gupta, S.; Brake, S. S.; Bazylinski, D. A.

    2007-12-01

    Lipids extracted to determine the microbial biomass and community structure of an Fe-rich stromatolite from acid mine drainage (AMD) at the Green Valley coal mine site (GVS) in western Indiana correlate well with layers in the laminated stromatolite. The biomass of the top layer of the stromatolite was dominated by phototrophic organisms constituting 83% of the total biomass. Biomass of the lower layers was dominated by prokaryotic microorganisms. The presence of terminal methyl-branched fatty acids and mid methyl-branched fatty acids suggests the presence of Gram-positive and sulfate-reducing bacteria, respectively. Fungi appear to also be an important part of the AMD microbial communities as suggested by sterol profiles and the presence of polyunsaturated fatty acids. Hydroxy fatty acids and C19 cyclopropane fatty acids were also detected and likely originated from acid-producing, acidophilic bacteria. The presence of Archaea is indicated by abundant phospholipid ether-linked isoprenoid hydrocarbons (phytane and phytadienes). The AMD Fe-rich stromatolites at GVS, thus, appear to be formed by interactions of microbial communities composed of all three domains of life; Archaea, Bacteria, and Eukarya. Identification of microeukaryote-dominated stromatolites verifies the prominent role these organisms play in the formation and preservation of these structures. In addition, the production of oxygen through photosynthesis by these organisms in AMD systems may be important for retrodicting the interaction of microbial communities in Precambrian environments in the production of microbially mediated sedimentary structures and oxygenation of Earth's early atmosphere.

  1. Acid mine drainage. (Latest citations from the NTIS data base). Published Search

    SciTech Connect

    Not Available

    1992-04-01

    The bibliography contains citations concerning laboratory and field analyses of acid mine drainage. Topics include site investigations and characterization, remediation and monitoring programs, contaminant treatment research, and control and abatement studies. Chemical analyses of affected areas, and evaluation of terrestrial and aquatic ecosystem responses to acid drainage are also discussed. (Contains 250 citations and includes a subject term index and title list.)

  2. Acid Mine Drainage Passive Remediation: Potential Use of Alkaline Clay, Optimal Mixing Ratio and Long Term Impacts

    NASA Astrophysics Data System (ADS)

    Plaza, F.; Liang, X.; Wen, Y.; Perone, H.

    2015-12-01

    Acid mine drainage (AMD) is one of the most adverse environmental problems of the mine industry. Surface water and ground water affected by this pollution are characterized by their acidity and the high content of sulfates and heavy metals. In this study, alkaline clay, an industrial waste with a high pH, which is utilized in the alumina refining process, was used as the remediation material to inhibit pyrite oxidation. Through a series of batch and column experiments, complemented with field measurements and geochemical modeling, three important issues associated with this passive and auto sustainable acid mine drainage remediation method were investigated: 1) the potential use of alkaline clay as an AMD remediation material, 2) the adequate alkaline clay/coal refuse mixing ratio (AC/CR) to ensure pH values near to neutral conditions, and, 3) the prediction of long term impacts, in terms of the trends of the main parameters involved in this process such as pH, concentrations of sulfate, iron and other dissolved contaminants. Both field measurements and the samples used for the experiments came from a coal waste site located in Mather, Pennsylvania. Alkaline clay proved to be an effective remediation material for AMD. It was found that 10% AC/CR is an adequate mixing ratio (i.e. the upper limit), which has been also indicated by field measurements. The concentrations of some contaminants such as iron, manganese or sulfate are significantly reduced with the remediation approach, compared to those representative concentrations found in mine tailings. Moreover, results suggest a very reliable long-term stability of the remediation (i.e. neutral pH conditions are maintained), thus enhancing the generation of iron precipitates that could produce pyrite grain coating and hardpan (i.e. cemented layer) on the surface. These processes also made the amended layer less porous, thus increasing water retention and hindering oxygen diffusion.

  3. Removal of phosphorus from agricultural wastewaters using adsorption media prepared from acid mine drainage sludge

    USGS Publications Warehouse

    Sibrell, Philip L.; Montgomery, Gary A.; Ritenour, Kelsey L.; Tucker, Travis W.

    2009-01-01

    Excess phosphorus in wastewaters promotes eutrophication in receiving waterways. A??cost-effective method for the removal of phosphorus from water would significantly reduce the impact of such wastewaters on the environment. Acid mine drainage sludge is a waste product produced by the neutralization of acid mine drainage, and consists mainly of the same metal hydroxides used in traditional wastewater treatment for the removal of phosphorus. In this paper, we describe a method for the drying and pelletization of acid mine drainage sludge that results in a particulate media, which we have termed Ferroxysorb, for the removal of phosphorus from wastewater in an efficient packed bed contactor. Adsorption capacities are high, and kinetics rapid, such that a contact time of less than 5 min is sufficient for removal of 60-90% of the phosphorus, depending on the feed concentration and time in service. In addition, the adsorption capacity of the Ferroxysorb media was increased dramatically by using two columns in an alternating sequence so that each sludge bed receives alternating rest and adsorption cycles. A stripping procedure based on treatment with dilute sodium hydroxide was also developed that allows for recovery of the P from the media, with the possibility of generating a marketable fertilizer product. These results indicate that acid mine drainage sludges - hitherto thought of as undesirable wastes - can be used to remove phosphorus from wastewater, thus offsetting a portion of acid mine drainage treatment costs while at the same time improving water quality in sensitive watersheds.

  4. Humic acid decreases acute toxicity and ventilation frequency in eastern rainbowfish (Melanotaenia splendida splendida) exposed to acid mine drainage.

    PubMed

    Holland, Aleicia; Duivenvoorden, Leo J; Kinnear, Susan H W

    2014-12-01

    Acid mine drainage (AMD) is a global problem leading to the acidification of freshwaters, as well as contamination by heavy metals. The ability of humic substances (HS) such as humic acid (HA) to decrease toxicity of heavy metals is widely known, whereas limited studies have examined the ability of HS to decrease toxicity linked with multiple stressors such as those associated with AMD. This study investigated the ability of HA to decrease acute toxicity defined as morbidity and ventilation frequency (measured via the time elapsed for ten operculum movements) in eastern rainbowfish (Melanotaenia splendida splendida) exposed to the multiple stressors of AMD-driven heavy metal concentrations, together with low pH. Water from the Mount Morgan open pit (a now closed gold and copper mine site), located at Mount Morgan, Central Queensland, Australia, was used as the AMD source. Fish were exposed to zero per cent (pH 7.3), two per cent (pH 6.7), three per cent (pH 5.7) and four per cent (pH 4.6) AMD in the presence of 0, 10 and 20mg/L Aldrich Humic Acid (AHA) over 96h. HA was shown to significantly decrease the acute toxicity of AMD and its adverse effects on ventilation frequency. These results are important in showing that HA can influence toxicity of metal mixtures and low pH, thus indicating a potential role for HA in decreasing toxicity of multiple environmental stressors more widely, and possible value as a rehabilitation aid. PMID:25173849

  5. Mycogenic Mn(II) oxidation promotes remediation of acid mine drainage and other anthropogenically impacted environments

    NASA Astrophysics Data System (ADS)

    Santelli, C. M.; Chaput, D.; Hansel, C. M.; Burgos, W. D.

    2014-12-01

    Manganese is a pollutant in worldwide environments contaminated with metals and organics, such as acid mine drainage (AMD), freshwater ponds, and agricultural waste storage sites. Microorganisms contribute to the removal of dissolved Mn compounds in the environment by promoting Mn(II) oxidation reactions. The oxidation of Mn(II) results in the precipitation of sparingly soluble Mn(IV) oxide minerals, effectively removing the metal from the aqueous milieu (e.g., groundwater or wastewater streams). In recent years, our research has identified a diversity of Mn(II)-oxidizing fungi inhabiting these polluted environments, however their overall contribution to the remediation process in situ remains poorly understood. Here we present results of culture-based and Next Generation Sequencing (NGS) studies in AMD treatment systems actively remediating Mn and other metals where we profile the bacterial, fungal, algal and archaeal communities to determine the overall community diversity and to establish the relative abundance of known Mn(II) oxidizers. A variety of treatment systems with varying Mn-removal efficiencies were sampled to understand the relationship between remediation efficiency and microbial community composition and activity. Targeted-amplicon sequencing of DNA and RNA of the 16S rRNA genes (bacteria and archaea), 23S rRNA genes (algae) and ITS region (fungi) was performed using both 454 pyrosequencing and Illumina platforms. Results showed that only the fungal taxonomic profiles significantly differed between sites that removed the majority of influent Mn and those that did not. Specifically, Ascomycota (which include known Mn(II) oxidizers isolated from these treatment systems) dominated greater efficiency systems whereas less efficient systems were dominated by Basidiomycota. Furthermore, known Mn(II) oxidizers accounted for only a minor proportion of bacterial sequences but a far greater proportion of fungal sequences. These culture-independent studies lend

  6. Use of the Multispecies Freshwater Biomonitor to assess behavioral changes of Poecilia reticulata (Cyprinodontiformes: Poeciliidae) and Macrobrachium lanchesteri (Decapoda: Palaemonidae) in response to acid mine drainage: laboratory exposure.

    PubMed

    Mohti, Azmah; Shuhaimi-Othman, Mohammad; Gerhardt, Almut

    2012-09-01

    The behavioral responses of guppy Poecilia reticulata (Poeciliidae) and prawn Macrobrachium lanchesteri (Palaemonidae) individuals exposed to acid mine drainage (AMD) were monitored online in the laboratory with a Multispecies Freshwater Biomonitor™ (MFB). These responses were compared to those to reference water acidified to the respective pH values (ACID). Test animals in the juvenile stage were used for both species and were exposed to AMD and ACID for 24 hours. The stress behaviors of both test animals consisted mainly of decreased activity in AMD and increased activity in ACID, indicating that the metals in the AMD played a role as a stress factor in addition to pH. The locomotor activity levels of guppies and prawns for the ACID treatment were higher than the locomotor activity levels for the AMD treatment with increasing pH value. For guppies, significant differences were observed when specimens were exposed to AMD and ACID at pH 5.0 and 6.0; the percentage activities were only 16% and 12%, respectively, for AMD treatment, whereas for ACID treatment, the percentage activities were 35% and 40%, respectively, similar to the value of 36% for the controls. Similar trends were also observed for prawns, for which the percentage activities were only 6% and 4%, respectively, for AMD treatment, whereas for ACID treatment, the percentage activities were 31% and 38%, respectively, compared to 44% in the controls. This study showed that both species are suitable for use as indicators for ecotoxicity testing with the MFB. PMID:22868673

  7. Advances in biotreatment of acid mine drainage and biorecovery of metals: 2. Membrane bioreactor system for sulfate reduction.

    PubMed

    Tabak, Henry H; Govind, Rakesh

    2003-12-01

    Several biotreatmemt techniques for sulfate conversion by the sulfate reducing bacteria (SRB) have been proposed in the past, however few of them have been practically applied to treat sulfate containing acid mine drainage (AMD). This research deals with development of an innovative polypropylene hollow fiber membrane bioreactor system for the treatment of acid mine water from the Berkeley Pit, Butte, MT, using hydrogen consuming SRB biofilms. The advantages of using the membrane bioreactor over the conventional tall liquid phase sparged gas bioreactor systems are: large microporous membrane surface to the liquid phase; formation of hydrogen sulfide outside the membrane, preventing the mixing with the pressurized hydrogen gas inside the membrane; no requirement of gas recycle compressor; membrane surface is suitable for immobilization of active SRB, resulting in the formation of biofilms, thus preventing washout problems associated with suspended culture reactors; and lower operating costs in membrane bioreactors, eliminating gas recompression and gas recycle costs. Information is provided on sulfate reduction rate studies and on biokinetic tests with suspended SRB in anaerobic digester sludge and sediment master culture reactors and with SRB biofilms in bench-scale SRB membrane bioreactors. Biokinetic parameters have been determined using biokinetic models for the master culture and membrane bioreactor systems. Data are presented on the effect of acid mine water sulfate loading at 25, 50, 75 and 100 ml/min in scale-up SRB membrane units, under varied temperatures (25, 35 and 40 degrees C) to determine and optimize sulfate conversions for an effective AMD biotreatment. Pilot-scale studies have generated data on the effect of flow rates of acid mine water (MGD) and varied inlet sulfate concentrations in the influents on the resultant outlet sulfate concentration in the effluents and on the number of SRB membrane modules needed for the desired sulfate conversion in

  8. [Rice straw and sewage sludge as carbon sources for sulfate-reducing bacteria treating acid mine drainage].

    PubMed

    Su, Yu; Wang, Jin; Peng, Shu-chuan; Yue, Zheng-bo; Chen, Tian-hu; Jin, Jie

    2010-08-01

    The performance of three organic carbon sources was assessed in terms of sulfate reduction and main metal removal, by using sewage sludge as the source of sulfate-reducing bacteria (SRB) and adding rice straw and ethanol with equal quantity. Results indicated that sewage sludge which contained certain amount of alkaline material could neutralize acidity of acid mine drainage(AMD) on the first day of experiment, elevating pH value from the initial 2.5 to around 5.4-6.3 and achieving suitable pH condition for SRB growth. Sewage sludge contained fewer biodegradable organic substance, reactive mixture with single sewage sludge showed the lowest sulfate reduction (65.9%). When the single sewage sludge was supplemented with rice straw, SRB reducing sulfate was enhanced (79.2%), because the degradation rate of rice straw was accelerated by the specific bacteria in sewage sludge, providing relatively abundant carbon source for SRB. Control experiment with ethanol was most effective in promoting sulfate reduction (97.9%). Metal removal efficiency in all three reactors was as high as 99% for copper, early copper removal was mainly attributed to the adsorption capacity of sewage sludge prior to SRB acclimation. It is feasible for using rice straw and sewage sludge as carbon sources for SRB treating acid mine drainage at a low cost, this may have significant implication for in situ bioremediation of mine environment. PMID:21090305

  9. [Microbial diversity and ammonia-oxidizing microorganism of a soil sample near an acid mine drainage lake].

    PubMed

    Liu, Ying; Wang, Li-Hua; Hao, Chun-Bo; Li, Lu; Li, Si-Yuan; Feng, Chuan-Ping

    2014-06-01

    The main physicochemical parameters of the soil sample which was collected near an acid mine drainage reservoir in Anhui province was analyzed. The microbial diversity and community structure was studied through the construction of bacteria and archaea 16S rRNA gene clone libraries and ammonia monooxygenase gene clone library of archaea. The functional groups which were responsible for the process of ammonia oxidation were also discussed. The results indicated that the soil sample had extreme low pH value (pH < 3) and high ions concentration, which was influenced by the acid mine drainage (AMD). All the 16S rRNA gene sequences of bacteria clone library fell into 11 phyla, and Acidobacteria played the most significant role in the ecosystem followed by Verrucomicrobia. A great number of acidophilic bacteria existed in the soil sample, such as Candidatus Koribacter versatilis and Holophaga sp.. The archaea clone library consisted of 2 phyla (Thaumarchaeota and Euryarchaeota). The abundance of Thaumarchaeota was remarkably higher than Euryarchaeota. The ammonia oxidation in the soil environment was probably driven by ammonia-oxidizing archaea, and new species of ammonia-oxidizing archaea existed in the soil sample. PMID:25158511

  10. Acid Mine Drainage and Metal Sulfate Minerals in the Shasta Mining District, California

    NASA Astrophysics Data System (ADS)

    Livingston, J. D.; Murphy, W. M.; Miller, R. M.; Ayars, E. J.

    2005-12-01

    Metal sulfate minerals were collected at four surface water drainage sites during September and October of 2004 in the Shasta Mining District, southern Klamath Mountains, Shasta County, California and analyzed by X-ray fluorescence, atomic absorption spectroscopy, and X-ray diffraction to determine elements present, quantities of Fe, Cu, and Zn, and mineralogy. The Shasta Mining District produced major quantities of Cu, Zn, and pyrite (S) with minor amounts of Au, Ag, and Fe from massive sulfide bodies (Kinkel et al., 1956). Three study sites are located on Iron Mountain and one study site is at Bully Hill. Although mining occurred during a period of just over 100 years, it is estimated that acid mine drainage (AMD) will continue from Iron Mountain for over 3,200 years (Nordstrom and Alpers, 1998). AMD at the study sites produces blooms of metal sulfates during California's Mediterranean climate summer. The minerals readily dissolve in the "first flush" of seasonal rain creating runoff water of low pH with high amounts of dissolved metals (Bayless and Olyphant, 1993; Jambor et al., 2000). Data were examined for mineralogical changes in time and space and for zoning of minerals on a scale of centimeters. Sulfate mineral samples are complex with some samples composed of over a dozen different minerals. Site 1 is located on Spring Creek downstream from the Iron Mountain superfund remediation site, so levels of Fe, Cu, and Zn in the sulfates at this site are lower than at the other sites. Two site 1 samples from the same location taken a month apart show Ca, Fe, Cu, Sr, Y, and Sn, and the first sample also has detectable Br. The metal sulfates identified from the first visit are celestine, cesanite, chessexite, hectorfloresite, and ungemachite, and the mineralogy of the second visit is bilinite, epsomite, millosevichite, and anhydrite. The Fe bearing sulfate mineral during the first visit is ungemachite, but bilinite was the Fe bearing mineral at the time of the second

  11. Acid mine drainage simulated leaching behavior of goethite and cobalt substituted goethite

    NASA Astrophysics Data System (ADS)

    Penprase, S. B.; Kimball, B. E.

    2015-12-01

    Though most modern day mining aims to eliminate the seepage of acid mine drainage (AMD) to the local watershed, historical mines regularly receive little to no remediation, and often release acidic, metal-rich drainage and particles to the environment. Treatment of AMD often includes neutralizing pH to facilitate the precipitation of Fe-oxides and dissolved trace metals, thereby forming Trace Metal Substituted (TMS) forms of known minerals, such as goethite (α-FeOOH). The stability of TMS precipitates is not fully understood. As a result, we conducted a 20 day leach experiment using laboratory synthesized pure (Gt) and cobalt-substituted (CoGt) goethites with a dilute ultrapure HCl solution (pH = 3.61) at T = 23.3±2.5ºC. Leached solids were characterized using X-ray diffraction (XRD) and scanning electron microscopy paired with energy dispersive spectroscopy (SEM-EDS). Leach solutions were sampled for pH and conductivity, and dissolved chemistry was determined with Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Preliminary results indicate Gt and CoGt filtered leach solutions experienced constant pH (Gt = 3.9 ± 0.1, CoGt = 6.8 ± 0.2) and conductivity (Gt = 69 ± 6.6 μS/cm, CoGt = 81 ± 16 μS/cm) for t = 0-20 days. Micro-focused XRD results indicate that leached solids did not change in mineralogy throughout the experiment, and SEM images show minor disintegration along mineral grain edges, but little overall change in shape. Preliminary ICP-MS results show lower dissolved Fe concentrations for CoGt (1.1 ± 1.1 ppb) compared to Gt (17 ± 8.9 ppb) over time. Dissolved Co concentrations ranged from 560 - 830 ppb and increased over time. Compared to leaching of pure Gt, leaching of CoGt generated significantly higher pH, slightly higher conductivity, and significantly less dissolved Fe. During the CoGt leach, Co was preferentially leached over Fe. The differences in leaching behavior between pure and TMS goethite in the laboratory have implications for

  12. Water quality changes in acid mine drainage streams in Gangneung, Korea, 10 years after treatment with limestone

    SciTech Connect

    Shim, Moo Joon; Choi, Byoung Young; Lee, Giehyeon; Hwang, Yun Ho; Yang, Jung-Seok; O'Loughlin, Edward J.; Kwon, Man Jae

    2015-12-01

    To determine the long-term effectiveness of the limestone treatment for acid mine drainage (AMD) in Gangneung, Korea, we investigated the elemental distribution in streams impacted by AMD and compared the results of previous studies before and approximately 10 years after the addition of limestone. Addition of limestone in 1999 leads to a pH increase in 2008, and with the exception of Ca, the elemental concentrations (e.g., Fe, Mn, Mg, Sr, Ni, Zn, S) in the streams decreased. The pH was 2.5–3 before the addition of limestone and remained stable at around 4.5–5 from 2008 to 2011, suggesting the reactivity of the added limestone was diminished and that an alternative approach is needed to increase the pH up to circumneutral range and maintain effective long-term treatment. To identify the processes causing the decrease in the elemental concentrations, we also examined the spatial (approximately 7 km) distribution over three different types of streams affected by the AMD. The elemental distribution was mainly controlled by physicochemical processes including redox reactions, dilution on mixing, and co-precipitation/adsorption with Fe (hydr)oxides.

  13. Natural wetlands are efficient at providing long-term metal remediation of freshwater systems polluted by acid mine drainage.

    PubMed

    Dean, Andrew P; Lynch, Sarah; Rowland, Paul; Toft, Benjamin D; Pittman, Jon K; White, Keith N

    2013-01-01

    This study describes the first long-term (14-year) evaluation of the efficacy of an established (>100 years) natural wetland to remediate highly acidic mine drainage (AMD). Although natural wetlands are highly valued for their biodiversity, this study demonstrates that they also provide important ecosystem service functions through their ability to consistently and reliably improve water quality by mitigating AMD. The Afon Goch river flows from Parys Mountain copper mine via a natural wetland, and was the major source of Zn and Cu contamination to the Irish Sea. Prior to 2003 the wetland received severe acidic metal contamination and retained a large proportion of the contamination (55, 64, and 37% in dissolved Fe, Zn, and Cu) leading to a greatly reduced metal flow to the Irish Sea. Reduced wetland loadings midway through the sampling period led to a reduction of metals by 83-94% and a pH increase from 2.7 to 5.5, resulting in long-term improvements in the downstream benthic invertebrate community. High root metal accumulation by the dominant wetland plant species and the association of acidophilic bacteria in the wetland rhizosphere indicate that multiple interacting processes provide an efficient and self-sustaining system to remediate AMD. PMID:24088022

  14. Inhibition of acid mine drainage and immobilization of heavy metals from copper flotation tailings using a marble cutting waste

    NASA Astrophysics Data System (ADS)

    Tozsin, Gulsen

    2016-01-01

    Acid mine drainage (AMD) with high concentrations of sulfates and metals is generated by the oxidation of sulfide bearing wastes. CaCO3-rich marble cutting waste is a residual material produced by the cutting and polishing of marble stone. In this study, the feasibility of using the marble cutting waste as an acid-neutralizing agent to inhibit AMD and immobilize heavy metals from copper flotation tailings (sulfide- bearing wastes) was investigated. Continuous-stirring shake-flask tests were conducted for 40 d, and the pH value, sulfate content, and dissolved metal content of the leachate were analyzed every 10 d to determine the effectiveness of the marble cutting waste as an acid neutralizer. For comparison, CaCO3 was also used as a neutralizing agent. The average pH value of the leachate was 2.1 at the beginning of the experiment ( t = 0). In the experiment employing the marble cutting waste, the pH value of the leachate changed from 6.5 to 7.8, and the sulfate and iron concentrations decreased from 4558 to 838 mg/L and from 536 to 0.01 mg/L, respectively, after 40 d. The marble cutting waste also removed more than 80wt% of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) from AMD generated by copper flotation tailings.

  15. Effect of an acid mine drainage effluent on phytoplankton biomass and primary production at Britannia Beach, Howe Sound, British Columbia.

    PubMed

    Levings, C D; Varela, D E; Mehlenbacher, N M; Barry, K L; Piercey, G E; Guo, M; Harrison, P J

    2005-12-01

    We investigated the effect of acid mine drainage (AMD) from an abandoned copper mine at Britannia Beach (Howe Sound, BC, Canada) on primary productivity and chlorophyll a levels in the receiving waters of Howe Sound before, during, and after freshet from the Squamish River. Elevated concentrations of copper (integrated average through the water column >0.050 mgl(-1)) in nearshore waters indicated that under some conditions a small gyre near the mouth of Britannia Creek may have retained the AMD from Britannia Creek and from a 30-m deep water outfall close to shore. Regression and correlation analyses indicated that copper negatively affected primary productivity during April (pre-freshet) and November (post-freshet). Negative effects of copper on primary productivity were not supported statistically for July (freshet), possibly because of additional effects such as turbidity from the Squamish River. Depth-integrated average and surface chlorophyll a were correlated to copper concentrations in April. During this short study we demonstrated that copper concentrations from the AMD discharge can negatively affect both primary productivity and the standing stock of primary producers in Howe Sound. PMID:16038945

  16. TREATMENT OF ACID MINE DRAINAGE USING FISHBONE APATITE IITM

    SciTech Connect

    Neal A. Yancey

    2006-10-01

    ABSTRACT. In 2000, a reactive barrier was installed on the East Fork of Ninemile Creek near Wallace, Idaho to treat acid mine discharge. The barrier was filled with fishbone derived Apatite IITM to remove the contaminants of concern (Zn, Pb, and Cd) and raise the pH of the acidic mine discharge. Metal removal has been achieved by a combination of chemical, biological, and physical precipitation. Flow for the water ranges from 5 to 35 gallons per minute. The water is successfully being treated, but the system experienced varying degrees of plugging. In 2002, gravel was mixed with the Apatite IITM to help control plugging. In 2003 the Idaho National Laboratory was ask to provide technical support to the Coeur d’Alene Basin Commission to help identify a remedy to the plugging issue. Air sparging was employed to treat the plugging issues. Plastic packing rings were added in the fall of 2005, which have increased the void space in the media and increased flows during the 10 months of operation since the improvements were made.

  17. Denitrification in Streams Impacted by Acid Mine Drainage: Effects of Iron, pH, and Potential Electron Donors

    NASA Astrophysics Data System (ADS)

    Baeseman, J. L.; Smith, R. L.; Silverstein, J.

    2003-12-01

    Acid mine drainage (AMD) contaminates between 8,000 and 16,000 km of streams on U.S. Forest Service land in the Western United States and more than 7,000 km of stream in the Eastern U.S. Relatively little is known about nitrogen cycling in these acidic, heavy metal laden streams, however, denitrification can be inhibited under low pH conditions. The objective of this research was to examine AMD sediments for bacteria capable of denitrification. The process of denitrification is known to increase pH, which may be particularly important in acidic environments. Denitrification potential was assessed in AMD sediments from several Colorado AMD impacted streams ranging from pH 2.6 to 4.91, using microcosm incubations with fresh sediments. Added nitrate was immediately reduced to nitrogen gas without any lag period, indicating that denitrification was actively occurring in these environments. Rates varied from 0.33 to 2.52 umoles NO3-N/ g-sediment/ day depending on the site. The pH of the microcosms increased between 0.23 to 1.49 pH units in 5 days, depending on the site. Additional microcosm studies were conducted to examine the effects of iron concentrations (Fe2+ and Fe3+), initial pH conditions, and several potential electron donors. Addition of iron above ambient concentrations seemed to have little effect on denitrification rates, whereas rates increased with increasing initial pH. The addition of carbon and hydrogen stimulated denitrification rates, which in turn increased the rise in pH. These results suggest that not only is denitrification possible in AMD streams, it may also be a useful remediation option, if suitable methods can be found to stimulate activity.

  18. Hyperspectral analysis for qualitative and quantitative features related to acid mine drainage at a remediated open-pit mine

    NASA Astrophysics Data System (ADS)

    Davies, G.; Calvin, W. M.

    2015-12-01

    The exposure of pyrite to oxygen and water in mine waste environments is known to generate acidity and the accumulation of secondary iron minerals. Sulfates and secondary iron minerals associated with acid mine drainage (AMD) exhibit diverse spectral properties in the ultraviolet, visible and near-infrared regions of the electromagnetic spectrum. The use of hyperspectral imagery for identification of AMD mineralogy and contamination has been well studied. Fewer studies have examined the impacts of hydrologic variations on mapping AMD or the unique spectral signatures of mine waters. Open-pit mine lakes are an additional environmental hazard which have not been widely studied using imaging spectroscopy. A better understanding of AMD variation related to climate fluctuations and the spectral signatures of contaminated surface waters will aid future assessments of environmental contamination. This study examined the ability of multi-season airborne hyperspectral data to identify the geochemical evolution of substances and contaminant patterns at the Leviathan Mine Superfund site. The mine is located 24 miles southeast of Lake Tahoe and contains remnant tailings piles and several AMD collection ponds. The objectives were to 1) distinguish temporal changes in mineralogy at a the remediated open-pit sulfur mine, 2) identify the absorption features of mine affected waters, and 3) quantitatively link water spectra to known dissolved iron concentrations. Images from NASA's AVIRIS instrument were collected in the spring, summer, and fall seasons for two consecutive years at Leviathan (HyspIRI campaign). Images had a spatial resolution of 15 meters at nadir. Ground-based surveys using the ASD FieldSpecPro spectrometer and laboratory spectral and chemical analysis complemented the remote sensing data. Temporal changes in surface mineralogy were difficult to distinguish. However, seasonal changes in pond water quality were identified. Dissolved ferric iron and chlorophyll

  19. Water chemistry and ecotoxicity of an acid mine drainage-affected stream in subtropical China during a major flood event.

    PubMed

    Lin, C; Wu, Y; Lu, W; Chen, A; Liu, Y

    2007-04-01

    Field and laboratory work was carried out to investigate the chemistry and ecotoxicity of stream water affected by acid mine drainage in a tributary catchment of the Pearl River in subtropical China during a major flood that corresponded to a return period of 100 years. The results indicate that stream water was affected by acid mine drainage from the Dabaoshan mine at least to a distance of 25 km downstream of the mine water discharge point. It appears that H(+) generated from sulfide oxidation in the waste rock dumps was readily available for exporting. The amount of H(+) being discharged into the receiving stream depended on the volume of out-flowing waters. However, there was a lag time for the discharges of the metals. This may be attributed to the slower release of metals, relative to H(+), because it might take more time for the dissolution of heavy metal-bearing compounds, particularly the sparsely soluble jarosites. Fe, Zn and Al were the major metals of potential toxicity contained in the AMD-affected stream water, followed by Mn, Cu, Pb, As, Cd and Ni. The concentrations of these metals in the water decreased rapidly down the stream. This corresponds with an increase in the concentrations of reactive heavy metal fractions in benthic mud down the stream, reflecting the precipitation of heavy metal compounds with increasing pH and their subsequent deposition in the streambed. Toxicity tests show that the AMD-affected stream water at 3.5 km downstream of the discharge point was highly toxic to the test organism. At 25 km downstream of the discharge point where stream water pH was as high as 5.75, marked toxic responses of the test organism were still observed. PMID:16979817

  20. Heavy metals content in acid mine drainage at abandoned and active mining area

    NASA Astrophysics Data System (ADS)

    Hatar, Hazirah; Rahim, Sahibin Abd; Razi, Wan Mohd; Sahrani, Fathul Karim

    2013-11-01

    This study was conducted at former Barite Mine, Tasik Chini and former iron mine Sungai Lembing in Pahang, and also active gold mine at Lubuk Mandi, Terengganu. This study was conducted to determine heavy metals content in acid mine drainage (AMD) at the study areas. Fourteen water sampling stations within the study area were chosen for this purpose. In situ water characteristic determinations were carried out for pH, electrical conductivity (EC), redox potential (ORP) and total dissolved solid (TDS) using multi parameter YSI 556. Water samples were collected and analysed in the laboratory for sulfate, total acidity and heavy metals which follow the standard methods of APHA (1999) and HACH (2003). Heavy metals in the water samples were determined directly using Inductive Coupled Plasma Mass Spectrometry (ICP-MS). Data obtained showed a highly acidic mean of pH values with pH ranged from 2.6 ± 0.3 to 3.2 ± 0.2. Mean of electrical conductivity ranged from 0.57 ± 0.25 to 1.01 ± 0.70 mS/cm. Redox potential mean ranged from 487.40 ± 13.68 to 579.9 ± 80.46 mV. Mean of total dissolved solids (TDS) in AMD ranged from 306.50 ± 125.16 to 608.14 ± 411.64 mg/L. Mean of sulfate concentration in AMD ranged from 32.33 ± 1.41 to 207.08 ± 85.06 mg/L, whereas the mean of total acidity ranged from 69.17 ± 5.89 to 205.12 ± 170.83 mgCaCO3/L. Heavy metals content in AMD is dominated by Fe, Cu, Mn and Zn with mean concentrations range from 2.16 ± 1.61 to 36.31 ± 41.02 mg/L, 0.17 ± 0.13 to 11.06 ± 2.85 mg/L, 1.12 ± 0.65 to 7.17 ± 6.05 mg/L and 0.62 ± 0.21 to 6.56 ± 4.11 mg/L, respectively. Mean concentrations of Ni, Co, As, Cd and Pb were less than 0.21, 0.51, 0.24, 0.05 and 0.45 mg/L, respectively. Significant correlation occurred between Fe and Mn, Cu, Zn, Co and Cd. Water pH correlated negatively with all the heavy metals, whereas total acidity, sulfate, total dissolved solid, and redox potential correlated positively. The concentration of heavy metals in the AMD

  1. Metals in agricultural produce associated with acid-mine drainage in Mount Morgan (Queensland, Australia).

    PubMed

    Vicente-Beckett, Victoria A; McCauley, Gaylene J Taylor; Duivenvoorden, Leo J

    2016-01-01

    Acid-mine drainage (AMD) into the Dee River from the historic gold and copper mine in Mount Morgan, Queensland (Australia) has been of concern to farmers in the area since 1925. This study sought to determine the levels of AMD-related metals and sulfur in agricultural produce grown near the mine-impacted Dee River, compare these with similar produce grown in reference fields (which had no known AMD influence), and assess any potential health risk using relevant Australian or US guidelines. Analyses of lucerne (Medicago sativa; also known as alfalfa) from five Dee fields showed the following average concentrations (mg/kg dry basis): Cd < 1, Cu 11, Fe 106, Mn 52, Pb < 5, Zn 25 and S 3934; similar levels were found in lucerne hay (used as cattle feed) from two Dee fields. All lucerne and lucerne hay data were generally comparable with levels found in the lucerne reference fields, suggesting no AMD influence; the levels were within the US National Research Council (US NRC) guidelines for maximum tolerable cattle dietary intake. Pasture grass (also cattle feed) from two fields in the Dee River floodplains gave mean concentrations (mg/kg dry) of Cd 0.14, Cu 12, Fe 313, Mn 111, Pb 1.4, Zn 86 and S 2450. All metal levels from the Dee and from reference sites were below the US NRC guidelines for maximum tolerable cattle dietary intake; however, the average Cd, Cu and Fe levels in Dee samples were significantly greater than the corresponding levels in the pasture grass reference sites, suggesting AMD influence in the Dee samples. The average levels in the edible portions of mandarin oranges (Citrus reticulata) from Dee sites (mg/kg wet weight) were Cd 0.011, Cu 0.59, Fe 2.2, Mn 0.56, Pb 0.18, S 91 and Zn 0.96. Cd and Zn were less than or close to, average Fe and Mn levels were at most twice, Cd 1.8 or 6.5 times, and Pb 8.5 or 72 times the maximum levels in raw oranges reported in the US total diet study (TDS) or the Australian TDS, respectively. Average Cd, Fe, Mn, Pb and

  2. The Impact of Microbial Communities on Water Quality in an Acid Mine Drainage Impacted Watershed

    NASA Astrophysics Data System (ADS)

    McDaniel, G. R.; Rademacher, L. K.; Faul, K. L.; Brunell, M.; Burmeister, K. C.

    2011-12-01

    Acid mine drainage (AMD) from the former Leona Heights Sulfur mine in Oakland, CA, contributes toxic levels of Cu, Cd, and Zn and elevated levels of Fe2+ and SO42- to downstream reaches of Lion Creek via Leona Creek. To investigate the extent of AMD and its relationship to microbial community structure, water samples were collected from three tributaries (two natural, and one with AMD) as well as the inlet and outlet of Lake Aliso (a reservoir downstream of the confluence of the three tributaries) beginning in July 2009. Lake Aliso was dammed in the late 1800s but since the early 1990s it has been full during the dry season and drained during the wet season, thus dramatically altering the geochemical conditions on a seasonal basis. Natural waters from Lion Creek and Horseshoe Creek tributaries dilute the water from Leona Creek, thus reducing concentrations of major ions and metals below toxic levels before water discharges into Lake Aliso. Precipitation events lead to episodes of increased mobilization of Cu and Cd in Leona Creek and produce toxic levels of these metals below the confluence with Lion Creek. Tributary mixing calculations suggest that even though Leona Creek contributes the smallest volume of water of the three tributaries, it is the main source of metals entering Lake Aliso. The input of the metal-rich AMD from Leona Creek changes the redox conditions of Lion Creek. In addition, Lake Aliso has a significant impact on water quality in the Lion Creek watershed. Observations of temperature, conductivity, pH, and dissolved oxygen in lake depth profiles indicate that Lake Aliso is stratified during the dry season when the lake is full. Based on concentration differences between the inlet and outlet of the lake, Na, Mg, SO42-, Ca, Mn, Zn, Cd, Cu and Ni are removed from the water while K, As, Pb and Fe are mobilized when Lake Aliso is full. Geochemical modeling using PhreeqcI suggests the deposition of minerals containing the metals that are being removed

  3. Ash utilization for elimination of acid mine drainage

    SciTech Connect

    Petzrick, P.

    1997-09-01

    Maryland is surrounded by states whose coal production exceeds its own, namely West Virginia, Pennsylvania, and Virginia. Because of the State`s relatively limited coal production, the distribution of Abandoned Mine Land (AML) funds mandated by law leaves the State at a disadvantage. In order to support maryland`s overall ash utilization program, the State solicits assistance from electric utilities and any other parties who may benefit from the development of a cost-effective technology to seal abandoned underground mines with CCB-based grouts, replacing the conventional use of more costly Portland cement for such applications. The development of these mine sealing techniques can be used to abate Maryland`s AMD discharges, because sealing prevents the exposure of sulfur-bearing minerals in coal seams to oxygen and water, which causes AMD. Ultimately, it is for this reason that Maryland`s overall ash utilization program was developed: to coordinate and encourage the large-scale utilization of CCBs to eliminate AMD in Maryland waters.

  4. Culture-independent Community Genomics Study of Microogranisms Associated with Acid Mine Drainage

    NASA Astrophysics Data System (ADS)

    Tyson, G. W.; Hugenholtz, P.; Detter, C.; Richardson, P. M.; Banfield, J. F.

    2002-12-01

    Acid mine drainage (AMD) is a serious environmental problem that occurs when pyrite (FeS2)-rich rocks are exposed to air, water, and oxidizing agents. Pyrite dissolution is exothermic, yielding hot, metal-rich, extremely acidic solutions. Despite the hostile nature of AMD environments, microbial communities thrive, and are believed to control the rates of pyrite dissolution and acid generation. Previous studies of microbial communities within the Richmond Mine at Iron Mt., Redding, CA, revealed low species-level diversity and established close connections between metabolism and geochemistry. Thus, these communities are ideal candidates for culture-independent genomics-enabled analyses. Samples collected from the Richmond Mine in March 2002 were screened using quantitative fluorescence in situ hybridization to choose the most suitable target community for a genomics-enabled ecological study. The community selected (a pink subaerial biofilm) has low species complexity but high phylogenetic diversity, containing ~75% Leptospirillum group II (closely related to Leptospirillum ferriphilum), ~10% Leptospirillum group III, and ~10% archaea that fall into three distinct groups within the Thermoplasmatales order (Ferroplasma sp., for which genome data is already available, A-plasma and D-plasma). High throughput sequencing of four 16S rDNA clone libraries confirmed the low species-level diversity in this community and suggested that the extent of microheterogeneity within each of the five populations was limited. 17 unique Leptospirillum group II 16S rDNA phylotypes (defined by one or more base change) were resolved, with ~85% belonging to one phylotype. The remaining ~15% were very similar in sequence identity, only diverging by 1.2% in total. Similarly, 14 unique Leptospirillum group III phylotypes formed a tight cluster with < 0.8% sequence divergence. The limited inter-species, and significant intra-species variation in the populations should allow determination of the

  5. NRMRL EVALUATES ACTIVE AND SEMI-PASSIVE TECHNOLOGIES FOR TREATING ACID MINE DRAINAGE

    EPA Science Inventory

    Two-page article describing three SITE demonstration projects underway on the Leviathan mine site in California. BiPhasic lime treatment, lime treatment lagoons and compost free BioReactors are being evaluated as innovative technologies for treating acid mine drainage.

  6. SYNROCK, AN INNOVATIVE TECHNOLOGY FOR PASSIVE TREATMENT OF ACID MINE DRAINAGE

    EPA Science Inventory

    Researchers have for decades tried to use natural alkaline rock, like limestone and dolomite, to treat acid mine drainage. The major problem has been the slow release of alkalinity and pH limitations. This project is working to develop a man-made rock-like material using cement a...

  7. Draft Genome Sequences of Two Novel Acidimicrobiaceae Members from an Acid Mine Drainage Biofilm Metagenome.

    PubMed

    Pinto, Ameet J; Sharp, Jonathan O; Yoder, Michael J; Almstrand, Robert

    2016-01-01

    Bacteria belonging to the family Acidimicrobiaceae are frequently encountered in heavy metal-contaminated acidic environments. However, their phylogenetic and metabolic diversity is poorly resolved. We present draft genome sequences of two novel and phylogenetically distinct Acidimicrobiaceae members assembled from an acid mine drainage biofilm metagenome. PMID:26769942

  8. TREATMENT OF ACID MINE DRAINAGE BY THE ALUMINA-LIME-SODA PROCESS

    EPA Science Inventory

    The alumina-lime-soda process is a chemical desalination process for waters in which the principal sources of salinity are sulfate salts and has been field tested at the Commonwealth of Pennsylvania's Acid Mine Drainage Research Facility, Hollywood, Pennsylvania, as a method to r...

  9. Draft Genome Sequences of Two Novel Acidimicrobiaceae Members from an Acid Mine Drainage Biofilm Metagenome

    PubMed Central

    Pinto, Ameet J.; Sharp, Jonathan O.; Yoder, Michael J.

    2016-01-01

    Bacteria belonging to the family Acidimicrobiaceae are frequently encountered in heavy metal-contaminated acidic environments. However, their phylogenetic and metabolic diversity is poorly resolved. We present draft genome sequences of two novel and phylogenetically distinct Acidimicrobiaceae members assembled from an acid mine drainage biofilm metagenome. PMID:26769942

  10. SITE PROGRAM EVALUATION OF INNOVATIVE ACID MINE DRAINAGE TREATMENT TECHNOLOGIES AT THE LEVIATHAN MINE SITE, CA

    EPA Science Inventory

    The EPA SITE Program is conducting a detailed sampling and evaluation of several innovative acid mine drainage treatment technologies at the Leviathan Mine Superfund site in California. Technologies include BiPhasic Lime Treatment Plant, an alkaline lagoon, and an innovative bio...

  11. MINE WASTE TECHNOLOGY PROGRAM PREVENTION OF ACID MINE DRAINAGE GENERATION FROM OPEN-PIT HIGHWALLS

    EPA Science Inventory

    This document summarizes the results of Mine Waste Technology Program Activity III, Project 26, Prevention of Acid Mine Drainage Generation from Open-Pit Highwalls. The intent of this project was to obtain performance data on the ability of four technologies to prevent the gener...

  12. Interaction of trace elements in acid mine drainage solution with humic acid.

    PubMed

    Suteerapataranon, Siripat; Bouby, Muriel; Geckeis, Horst; Fanghänel, Thomas; Grudpan, Kate

    2006-06-01

    The release of metal ions from a coal mining tailing area, Lamphun, Northern Thailand, is studied by leaching tests. Considerable amounts of Mn, Fe, Al, Ni and Co are dissolved in both simulated rain water (pH 4) and 10 mg L(-1) humic acid (HA) solution (Aldrich humic acid, pH 7). Due to the presence of oxidizing pyrite and sulfide minerals, the pH in both leachates decreases down to approximately 3 combined with high sulfate concentrations typical to acid mine drainage (AMD) water composition. Interaction of the acidic leachates upon mixing with ground- and surface water containing natural organic matter is simulated by subsequent dilution (1:100; 1:200; 1:300; 1:500) with a 10 mg L(-1) HA solution (ionic strength: 10(-3) mol L(-1)). Combining asymmetric flow field-flow fractionation (AsFlFFF) with UV/Vis and ICP-MS detection allows for the investigation of metal ion interaction with HA colloid and colloid size evolution. Formation of colloid aggregates is observed by filtration and AsFlFFF depending on the degree of the dilution. While the average HA size is initially found to be 2 nm, metal-HA complexes are always found to be larger. Such observation is attributed to a metal induced HA agglomeration, which is found even at low coverage of HA functional groups with metal ions. Increasing the metal ion to HA ratio, the HA bound metal ions and the HA entities are growing in size from <3 to >450 nm. At high metal ion to HA ratios, precipitation of FeOOH phases and HA agglomeration due to colloid charge neutralization by complete saturation of HA complexing sites are responsible for the fact that most of Fe and Al precipitate and are found in a size fraction >450 nm. In the more diluted solutions, HA is more relevant as a carrier for metal ion mobilization. PMID:16631855

  13. Acid mine drainage. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1997-06-01

    The bibliography contains citations concerning laboratory and field analyses of acid mine drainage. Topics include site investigations and characterization, remediation and monitoring programs, contaminant treatment research, and control and abatement studies. Chemical analyses of affected areas, and evaluation of terrestrial and aquatic ecosystem responses to acid drainage are also discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  14. Acid mine drainage. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1996-04-01

    The bibliography contains citations concerning laboratory and field analyses of acid mine drainage. Topics include site investigations and characterization, remediation and monitoring programs, contaminant treatment research, and control and abatement studies. Chemical analyses of affected areas, and evaluation of terrestrial and aquatic ecosystem responses to acid drainage are also discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  15. Characterization of Acid Mine Drainage Sources Using Stable and Radiogenic Isotopes, Chalk Creek, Colorado

    NASA Astrophysics Data System (ADS)

    Cordalis, D.; Michel, R.; Williams, M.; Wireman, M.

    2003-12-01

    Acid mine drainage (AMD) affects many streams throughout the western United States. Understanding flow dynamics and sources within a fractured rock setting is necessary in outlining a potential remediation strategy for AMD. Radiogenic and stable isotopes of water were used in the Mary Murphy Mine, Chalk Creek, Colorado, in order to characterize flowpaths and sourcewaters. By delineating the sources of the mine water, groundwater, and event water, we may be able to target remediation techniques for individual contamination sources. Moreover, results from this research provide insights into groundwater flow systems in mountain environments of the Colorado Rockies. Tritium, a cosmogenic isotope of hydrogen, has a half-life 12.43y and is useful for studying hydrologic processes at the decadal time scale and can be used as an effective tracer when traditional chemical tracers are non-conservative. Hydrometric information showed that discharge from the mine adit exhibited a hydrograph characteristic of snowmelt runoff. However, mixing models using stable water isotopes (D and 18O) found less than 7% of the mine's peak discharge was from snowmelt, suggesting a regional groundwater dominated system. Mine interior samples fell into two characteristic groupings: either from the extreme north side of the drift which contained most of the zinc contamination, and all other locations. The waters from the north drift, MVN-3 and MVN-4, had lower 18O values, -17.62 per mil and -17.17 per mil, respectively, than did any of the other locations, suggesting a seasonal snowmelt input. However, the tritium values associated with MVN-3 and MVN-4 suggest at least some mixing, with values of 13.4 TU and 12.5 TU, respectively. Surface water samples from Chalk Creek show average tritium values of 11.1 TU, and 18O values of -14.87 per mil. Groundwater samples were captured using monitoring wells, and plotted according to the depth of screening. Alluvial wells carried a seasonal signal similar

  16. Microbial stratification in low pH oxic and suboxic macroscopic growths along an acid mine drainage.

    PubMed

    Méndez-García, Celia; Mesa, Victoria; Sprenger, Richard R; Richter, Michael; Diez, María Suárez; Solano, Jennifer; Bargiela, Rafael; Golyshina, Olga V; Manteca, Ángel; Ramos, Juan Luis; Gallego, José R; Llorente, Irene; Martins dos Santos, Vitor A P; Jensen, Ole N; Peláez, Ana I; Sánchez, Jesús; Ferrer, Manuel

    2014-06-01

    Macroscopic growths at geographically separated acid mine drainages (AMDs) exhibit distinct populations. Yet, local heterogeneities are poorly understood. To gain novel mechanistic insights into this, we used OMICs tools to profile microbial populations coexisting in a single pyrite gallery AMD (pH ∼2) in three distinct compartments: two from a stratified streamer (uppermost oxic and lowermost anoxic sediment-attached strata) and one from a submerged anoxic non-stratified mat biofilm. The communities colonising pyrite and those in the mature formations appear to be populated by the greatest diversity of bacteria and archaea (including 'ARMAN' (archaeal Richmond Mine acidophilic nano-organisms)-related), as compared with the known AMD, with ∼44.9% unclassified sequences. We propose that the thick polymeric matrix may provide a safety shield against the prevailing extreme condition and also a massive carbon source, enabling non-typical acidophiles to develop more easily. Only 1 of 39 species were shared, suggesting a high metabolic heterogeneity in local microenvironments, defined by the O2 concentration, spatial location and biofilm architecture. The suboxic mats, compositionally most similar to each other, are more diverse and active for S, CO2, CH4, fatty acid and lipopolysaccharide metabolism. The oxic stratum of the streamer, displaying a higher diversity of the so-called 'ARMAN'-related Euryarchaeota, shows a higher expression level of proteins involved in signal transduction, cell growth and N, H2, Fe, aromatic amino acids, sphingolipid and peptidoglycan metabolism. Our study is the first to highlight profound taxonomic and functional shifts in single AMD formations, as well as new microbial species and the importance of H2 in acidic suboxic macroscopic growths. PMID:24430486

  17. Microbial stratification in low pH oxic and suboxic macroscopic growths along an acid mine drainage

    PubMed Central

    Méndez-García, Celia; Mesa, Victoria; Sprenger, Richard R; Richter, Michael; Diez, María Suárez; Solano, Jennifer; Bargiela, Rafael; Golyshina, Olga V; Manteca, Ángel; Ramos, Juan Luis; Gallego, José R; Llorente, Irene; Martins dos Santos, Vitor AP; Jensen, Ole N; Peláez, Ana I; Sánchez, Jesús; Ferrer, Manuel

    2014-01-01

    Macroscopic growths at geographically separated acid mine drainages (AMDs) exhibit distinct populations. Yet, local heterogeneities are poorly understood. To gain novel mechanistic insights into this, we used OMICs tools to profile microbial populations coexisting in a single pyrite gallery AMD (pH ∼2) in three distinct compartments: two from a stratified streamer (uppermost oxic and lowermost anoxic sediment-attached strata) and one from a submerged anoxic non-stratified mat biofilm. The communities colonising pyrite and those in the mature formations appear to be populated by the greatest diversity of bacteria and archaea (including ‘ARMAN' (archaeal Richmond Mine acidophilic nano-organisms)-related), as compared with the known AMD, with ∼44.9% unclassified sequences. We propose that the thick polymeric matrix may provide a safety shield against the prevailing extreme condition and also a massive carbon source, enabling non-typical acidophiles to develop more easily. Only 1 of 39 species were shared, suggesting a high metabolic heterogeneity in local microenvironments, defined by the O2 concentration, spatial location and biofilm architecture. The suboxic mats, compositionally most similar to each other, are more diverse and active for S, CO2, CH4, fatty acid and lipopolysaccharide metabolism. The oxic stratum of the streamer, displaying a higher diversity of the so-called ‘ARMAN'-related Euryarchaeota, shows a higher expression level of proteins involved in signal transduction, cell growth and N, H2, Fe, aromatic amino acids, sphingolipid and peptidoglycan metabolism. Our study is the first to highlight profound taxonomic and functional shifts in single AMD formations, as well as new microbial species and the importance of H2 in acidic suboxic macroscopic growths. PMID:24430486

  18. Fixed bed sorption of phosphorus from wastewater using iron oxide-based media derived from acid mine drainage

    USGS Publications Warehouse

    Sibrell, Philip L.; Tucker, T.W.

    2012-01-01

    Phosphorus (P) releases to the environment have been implicated in the eutrophication of important water bodies worldwide. Current technology for the removal of P from wastewaters consists of treatment with aluminum (Al) or iron (Fe) salts, but is expensive. The neutralization of acid mine drainage (AMD) generates sludge rich in Fe and Al oxides that has hitherto been considered a waste product, but these sludges could serve as an economical adsorption media for the removal of P from wastewaters. Therefore, we have evaluated an AMD-derived media as a sorbent for P in fixed bed sorption systems. The homogenous surface diffusion model (HSDM) was used to analyze fixed bed test data and to determine the value of related sorption parameters. The surface diffusion modulus Ed was found to be a useful predictor of sorption kinetics. Values of Ed < 0.2 were associated with early breakthrough of P, while more desirable S-shaped breakthrough curves resulted when 0.2 < Ed < 0.5. Computer simulations of the fixed bed process with the HSDM confirmed that if Ed was known, the shape of the breakthrough curve could be calculated. The surface diffusion coefficient D s was a critical factor in the calculation of Ed and could be estimated based on the sorption test conditions such as media characteristics, and influent flow rate and concentration. Optimal test results were obtained with a relatively small media particle size (average particle radius 0.028 cm) and resulted in 96 % removal of P from the influent over 46 days of continuous operation. These results indicate that fixed bed sorption of P would be a feasible option for the utilization of AMD residues, thus helping to decrease AMD treatment costs while at the same time ameliorating the impacts of P contamination.

  19. MODULAR FIELD-BIOREACTOR FOR ACID MINE DRAINAGE TREATMENT

    EPA Science Inventory

    The presentation focuses on the improvements to engineered features of a passive technology that has been used for remediation of acid rock drainage (ARD). This passive remedial technology, a sulfate-reducing bacteria (SRB) bioreactor, takes advantage of the ability of SRB that,...

  20. Kinetics and microbial ecology of batch sulfidogenic bioreactors for co-treatment of municipal wastewater and acid mine drainage.

    PubMed

    Deng, Dongyang; Weidhaas, Jennifer L; Lin, Lian-Shin

    2016-03-15

    The kinetics and microbial ecology in sulfidogenic bioreactors used in a novel two-stage process for co-treatment of acid mine drainage (AMD) and municipal wastewater (MWW) were investigated. Michaelis-Menten modeling of COD oxidation by sulfate reducing bacteria (SRB) (Vmax=0.33mgL(-1)min(-1), Km=4.3mgL(-1)) suggested that the Vmax can be reasonably achieved given the typical COD values in MWW and anticipated mixing with AMD. Non-competitive inhibition modeling (Ki=6.55mgL(-1)) indicated that excessive iron level should be avoided to limit its effects on SRB. The COD oxidation rate was positively correlated to COD/sulfate ratio and SRB population, as evidenced by dsrA gene copies. Phylogenetic analysis revealed diverse microbial communities dominated by sulfate reducing delta-proteobacteria. Microbial community and relative quantities of SRB showed significant differences under different COD/sulfate ratios (0.2, 1 and 2), and the highest dsrA gene concentration and most complex microbial diversity were observed under COD/sulfate ratio 2. Major species were associated with Desulfovirga, Desulfobulbus, Desulfovibrio, and Syntrophus sp. The reported COD kinetics, SRB abundances and the phylogenetic profile provide insights into the co-treatment process and help identify the parameters of concerns for such technology development. PMID:26686479

  1. Enrichment of rare earth elements as environmental tracers of contamination by acid mine drainage in salt marshes: a new perspective.

    PubMed

    Delgado, Joaquín; Pérez-López, Rafael; Galván, Laura; Nieto, José Miguel; Boski, Tomasz

    2012-09-01

    Rare earth elements (REE) were analyzed in surface sediments from the Guadiana Estuary (SW Iberian Pyrite Belt). NASC (North American Shale Composite) normalized REE patterns show clearly convex curvatures in middle-REE (MREE) with respect to light- and heavy-REE, indicating acid-mixing processes between fluvial waters affected by acid mine drainage (AMD) and seawater. However, REE distributions in the mouth (closer to the coastal area) show slightly LREE-enriched and flat patterns, indicating saline-mixing processes typical of the coastal zone. NASC-normalized ratios (La/Gd and La/Yb) do not discriminate between both mixing processes in the estuary. Instead, a new parameter (E(MREE)) has been applied to measure the curvature in the MREE segment. The values of E(MREE)>0 are indicative of acid signatures and their spatial distribution reveal the existence of two decantation zones from flocculation processes related to drought periods and flood events. Studying REE fractionation through the E(MREE) may serve as a good proxy for AMD-pollution in estuarine environments in relation to the traditional methods. PMID:22748838

  2. Environmental assessment and management of metal-rich wastes generated in acid mine drainage passive remediation systems.

    PubMed

    Macías, Francisco; Caraballo, Manuel A; Nieto, José Miguel

    2012-08-30

    As acid mine drainage (AMD) remediation is increasingly faced by governments and mining industries worldwide, the generation of metal-rich solid residues from the treatments plants is concomitantly raising. A proper environmental management of these metal-rich wastes requires a detailed characterization of the metal mobility as well as an assessment of this new residues stability. The European standard leaching test EN 12457-2, the US EPA TCLP test and the BCR sequential extraction procedure were selected to address the environmental assessment of dispersed alkaline substrate (DAS) residues generated in AMD passive treatment systems. Significant discrepancies were observed in the hazardousness classification of the residues according to the TCLP or EN 12457-2 test. Furthermore, the absence of some important metals (like Fe or Al) in the regulatory limits employed in both leaching tests severely restricts their applicability for metal-rich wastes. The results obtained in the BCR sequential extraction suggest an important influence of the landfill environmental conditions on the metals released from the wastes. To ensure a complete stability of the pollutants in the studied DAS-wastes the contact with water or any other leaching solutions must be avoided and a dry environment needs to be provided in the landfill disposal selected. PMID:22717063

  3. Bioaccumulation of metals in reeds collected from an acid mine drainage contaminated site in winter and spring.

    PubMed

    Guo, Lin; Cutright, Teresa J

    2016-07-01

    Wetland plants such as Phragmites australis has been used to treat acid mine drainage (AMD) contaminated soil which is a serious environmental issue worldwide. This project investigated metal plaque content(s) and metal uptake in reeds grown in an AMD field in winter and spring. The results indicated that the level of Fe plaque was much higher than Mn and Al plaque as the soil contained more Fe than Al and Mn. The amounts of Mn and Al plaque formed on reeds in spring were not significantly different from that in winter (p > .05). However, more Fe plaque was formed on reeds collected in spring. The concentrations of metals in underground organs were positively related to the metal levels in soils. More Mn and Al transferred to the aboveground tissues of reeds during the spring while the Fe levels in reeds did not significantly vary with seasons. Roots and rhizomes were the main organs for Fe sequestration (16.3 ± 4.15 mg/g in roots in spring) while most Al was sequestered in the shoots of reeds (2.05 ± 0.09 mg/g in shoots in spring). Further research may be needed to enhance the translocation of metals in reeds and increase the phytoremediation efficiency. PMID:26789500

  4. Characterization of water reservoirs affected by acid mine drainage: geochemical, mineralogical, and biological (diatoms) properties of the water.

    PubMed

    Valente, T; Rivera, M J; Almeida, S F P; Delgado, C; Gomes, P; Grande, J A; de la Torre, M L; Santisteban, M

    2016-04-01

    This work presents a combination of geochemical, mineralogical, and biological data obtained in water reservoirs located in one of the most paradigmatic mining regions, suffering from acid mine drainage (AMD) problems: the Iberian Pyrite Belt (IPB). Four water reservoirs located in the Spanish sector of the IBP, storing water for different purposes, were selected to achieve an environmental classification based on the effects of AMD: two mining dams (Gossan and Águas Ácidas), a reservoir for industrial use (Sancho), and one with water used for human supply (Andévalo). The results indicated that the four reservoirs are subject to the effect of metallic loads from polluted rivers, although with different levels: Águas Ácidas > Gossan > Sancho ≥ Andévalo. In accordance, epipsammic diatom communities have differences in the respective composition and dominant taxa. The dominant diatoms in each reservoir indicated acid water: Pinnularia acidophila and Pinnularia aljustrelica were found in the most acidic dams (Gossan and Águas Ácidas, with pH <3), Pinnularia subcapitata in Sancho (pH 2.48-5.82), and Eunotia exigua in Andévalo (pH 2.34-6.15). PMID:26032451

  5. Evaluation of the impact of acid mine drainage on the chemistry and the macrobenthos in the Carolina stream (San Luis, Argentina).

    PubMed

    Tripole, Susana; Gonzalez, Patricia; Vallania, Adriana; Garbagnati, Marcela; Mallea, Miguel

    2006-03-01

    The purpose of this study was to evaluate the impact of acid mine drainage on the chemistry and the macrobenthos of the Carolina stream (San Luis - Argentina). Samples were obtained in the years 1997-1998 at two sites: site C(1), located 200 m upstream of the drainage, and site C(2), located 800 m downstream. The system buffer capacity was evaluated in the non - contaminated site by means of the buffer index calculation. The physico - chemical changes observed as a consequence of the contribution of acid mine drainage (AMD) were: a decreasing of pH and an increase in the ionic concentration, especially sulfate and Fe coming from the oxidation produced by chemiolithotrophic bacteria. The values obtained indicated a low buffer capacity and a high intrinsic vulnerability of the system to resist the impact originated by the AMD, producing a remarkable decreasing of pH of the receiving stream. These changes caused modifications in the original benthic community that was replaced by organisms more tolerant to the acid stress. A reduction in the abundance and in the taxonomic richness of the benthic macroinvertebrates was observed when compared with the reference station. An increase in the proportion of Chironomidae and of Acari and a decrease in the proportion of the remaining taxa were observed. The most sensitive groups were Ephemeroptera, Trichoptera and Mollusca. The community was mostly affected by the following variables: pH, conductivity, sulfate and dissolved total Fe. PMID:16565803

  6. Relative acute toxicity of acid mine drainage water column and sediments to Daphnia magna in the Puckett's Creek Watershed, Virginia, USA.

    PubMed

    Soucek, D J; Cherry, D S; Trent, G C

    2000-04-01

    Acid mine drainage (AMD) is produced when pyrite (FeS(2)) is oxidized on exposure to oxygen and water to form ferric hydroxides and sulfuric acid. If produced in sufficient quantity, iron precipitate, heavy metals (depending on soil mineralogy), and sulfuric acid may contaminate surface and ground water. A previous study of an AMD impacted watershed (Puckett's Creek, Powell River drainage, southwestern Virginia, USA) conducted by these researchers indicated that both water column and sediment toxicity were significantly correlated with benthic macroinvertebrate community impacts. Sites that had toxic water or sediment samples had significantly reduced macroinvertebrate taxon richness. The present study was designed to investigate the relative acute toxicity of acid mine drainage (AMD) water column and sediments to a single test organism (Daphnia magna) and to determine which abiotic factors were the best indicators of toxicity in this system. Nine sampling stations were selected based on proximity to major AMD inputs in the watershed. In 48-h exposures, sediment samples from three stations were acutely toxic to D. magna, causing 64-100% mortality, whereas water samples from five stations caused 100% mortality of test organisms. Forty-eight-hour LC50 values ranged from 35 to 63% for sediment samples and 27 to 69% for water column samples. Sediment iron concentration and several water chemistry parameters were the best predictors of sediment toxicity, and water column pH was the best predictor of water toxicity. Based on these correlations and on the fact that toxic sediments had high percent water content, water chemistry appears to be a more important adverse influence in this system than sediment chemistry. PMID:10667927

  7. MiniSipper: a new in situ water sampler for high-resolution, long-duration acid mine drainage monitoring.

    PubMed

    Chapin, Thomas P; Todd, Andrew S

    2012-11-15

    Abandoned hard-rock mines can be a significant source of acid mine drainage (AMD) and toxic metal pollution to watersheds. In Colorado, USA, abandoned mines are often located in remote, high elevation areas that are snowbound for 7-8 months of the year. The difficulty in accessing these remote sites, especially during winter, creates challenging water sampling problems and major hydrologic and toxic metal loading events are often under sampled. Currently available automated water samplers are not well suited for sampling remote snowbound areas so the U.S. Geological Survey (USGS) has developed a new water sampler, the MiniSipper, to provide long-duration, high-resolution water sampling in remote areas. The MiniSipper is a small, portable sampler that uses gas bubbles to separate up to 250 five milliliter acidified samples in a long tubing coil. The MiniSipper operates for over 8 months unattended in water under snow/ice, reduces field work costs, and greatly increases sampling resolution, especially during inaccessible times. MiniSippers were deployed in support of an U.S. Environmental Protection Agency (EPA) project evaluating acid mine drainage inputs from the Pennsylvania Mine to the Snake River watershed in Summit County, CO, USA. MiniSipper metal results agree within 10% of EPA-USGS hand collected grab sample results. Our high-resolution results reveal very strong correlations (R(2)>0.9) between potentially toxic metals (Cd, Cu, and Zn) and specific conductivity at the Pennsylvania Mine site. The large number of samples collected by the MiniSipper over the entire water year provides a detailed look at the effects of major hydrologic events such as snowmelt runoff and rainstorms on metal loading from the Pennsylvania Mine. MiniSipper results will help guide EPA sampling strategy and remediation efforts in the Snake River watershed. PMID:23103760

  8. MiniSipper: A new in situ water sampler for high-resolution, long-duration acid mine drainage monitoring

    USGS Publications Warehouse

    Chapin, Thomas P.; Todd, Andrew S.

    2012-01-01

    Abandoned hard-rock mines can be a significant source of acid mine drainage (AMD) and toxic metal pollution to watersheds. In Colorado, USA, abandoned mines are often located in remote, high elevation areas that are snowbound for 7–8 months of the year. The difficulty in accessing these remote sites, especially during winter, creates challenging water sampling problems and major hydrologic and toxic metal loading events are often under sampled. Currently available automated water samplers are not well suited for sampling remote snowbound areas so the U.S. Geological Survey (USGS) has developed a new water sampler, the MiniSipper, to provide long-duration, high-resolution water sampling in remote areas. The MiniSipper is a small, portable sampler that uses gas bubbles to separate up to 250 five milliliter acidified samples in a long tubing coil. The MiniSipper operates for over 8 months unattended in water under snow/ice, reduces field work costs, and greatly increases sampling resolution, especially during inaccessible times. MiniSippers were deployed in support of an U.S. Environmental Protection Agency (EPA) project evaluating acid mine drainage inputs from the Pennsylvania Mine to the Snake River watershed in Summit County, CO, USA. MiniSipper metal results agree within 10% of EPA-USGS hand collected grab sample results. Our high-resolution results reveal very strong correlations (R2 > 0.9) between potentially toxic metals (Cd, Cu, and Zn) and specific conductivity at the Pennsylvania Mine site. The large number of samples collected by the MiniSipper over the entire water year provides a detailed look at the effects of major hydrologic events such as snowmelt runoff and rainstorms on metal loading from the Pennsylvania Mine. MiniSipper results will help guide EPA sampling strategy and remediation efforts in the Snake River watershed.

  9. Phycomicrobial ecology of acid mine drainage in the Piedmont of Virginia

    SciTech Connect

    Krishnaswamy, R.; Hanger, R.A.

    1998-12-31

    Acid mine drainage encompasses 18 km{sup 2} of Louisa County, Virginia. Heavy metal laden acidic leachate flows from abandoned mines along the Piedmont`s Gold-Pyrite Belt. The oxidation of pyrite, sphalerite, chalcopyrite and other sulfide minerals that are disseminated throughout the mine tailings release H{sub 2}SO{sub 4}, Fe, Cu, Zn, Ni, Cd, As, Pb and other heavy metals into the Contrary Creek watershed and beyond, into Lake Anna. Downstream of these abandoned pyrite mines, high levels of acidity and heavy metals have made this a severely stressed environment incapable of supporting a healthy creek ecosystem. In an effort to assess in-situ, bioaccumulatory remediation of acid mine drainage by phycomicrobial mats, surveys have been conducted for 11 months in Contrary Creek; several extremophiles that are tolerant of acid mine systems have been found. Twelve to thirteen genera of algae and a few cocci and bacilli have been identified in surface waters. Predominant genera include Ulothrix, Pinnularia and Oscillatoria. Preliminary results demonstrate that the phycomicrobial communities found in this acid mine system maintain density and species diversity independent of pH and heavy metal fluctuations. These extremophiles also demonstrate high potential for heavy metal sorption. Phycomicrobial mats bioaccumulate 60--70% more heavy metals than concentrations found in surface waters and the creek. To date, remediatory attempts to restore Contrary Creek have not been successful. Results suggest that the extremophile ecology found in this system will facilitate the remediation process of other, similar acid mine affected ecosystems.

  10. Preserving the distribution of inorganic arsenic species in groundwater and acid mine drainage samples.

    PubMed

    Bednar, A J; Garbarino, J R; Ranville, J F; Wildeman, T R

    2002-05-15

    The distribution of inorganic arsenic species must be preserved in the field to eliminate changes caused by metal oxyhydroxide precipitation, photochemical oxidation, and redox reactions. Arsenic species sorb to iron and manganese oxyhydroxide precipitates, and arsenite can be oxidized to arsenate by photolytically produced free radicals in many sample matrices. Several preservatives were evaluated to minimize metal oxyhydroxide precipitation, such as inorganic acids and ethylenediaminetetraacetic acid (EDTA). EDTA was found to work best for all sample matrices tested. Storing samples in opaque polyethylene bottles eliminated the effects of photochemical reactions. The preservation technique was tested on 71 groundwater and six acid mine drainage samples. Concentrations in groundwater samples reached 720 microg-As/L for arsenite and 1080 microg-As/L for arsenate, and acid mine drainage samples reached 13 000 microg-As/L for arsenite and 3700 microg-As/L for arsenate. The arsenic species distribution in the samples ranged from 0 to 90% arsenite. The stability of the preservation technique was established by comparing laboratory arsenic speciation results for samples preserved in the field to results for subsamples speciated onsite. Statistical analyses indicated that the difference between arsenite and arsenate concentrations for samples preserved with EDTA in opaque bottles and field speciation results were analytically insignificant. The percentage change in arsenite:arsenate ratios for a preserved acid mine drainage sample and groundwater sample during a 3-month period was -5 and +3%, respectively. PMID:12038832

  11. Acid mine drainage treatment using by-products from quicklime manufacturing as neutralization chemicals.

    PubMed

    Tolonen, Emma-Tuulia; Sarpola, Arja; Hu, Tao; Rämö, Jaakko; Lassi, Ulla

    2014-12-01

    The aim of this research was to investigate whether by-products from quicklime manufacturing could be used instead of commercial quicklime (CaO) or hydrated lime (Ca(OH)2), which are traditionally used as neutralization chemicals in acid mine drainage treatment. Four by-products were studied and the results were compared with quicklime and hydrated lime. The studied by-products were partly burnt lime stored outdoors, partly burnt lime stored in a silo, kiln dust and a mixture of partly burnt lime stored outdoors and dolomite. Present application options for these by-products are limited and they are largely considered waste. Chemical precipitation experiments were performed with the jar test. All the studied by-products removed over 99% of Al, As, Cd, Co, Cu, Fe, Mn, Ni, Zn and approximately 60% of sulphate from acid mine drainage. However, the neutralization capacity of the by-products and thus the amount of by-product needed as well as the amount of sludge produced varied. The results indicated that two out of the four studied by-products could be used as an alternative to quicklime or hydrated lime for acid mine drainage treatment. PMID:25193795

  12. Impact of acid mine drainage on haematological, histopathological and genotoxic effects in golden mahaseer, Tor putitora.

    PubMed

    Shahi, Neetu; Sarma, Debaji; Pandey, Jyoti; Das, Partha; Sarma, Dandadhar; Mallik, Sumanta Kumar

    2016-07-01

    The present study was carried out to evaluate sub-lethal mechanism of acid mine drainage toxicity in fingerlings (9.5 ± 2.4 cm) of golden mahseer, Tor putitora. Exposed fingerlings showed significant reduction (P < 0.01) in blood erythrocytes, neutrophils, thrombocytes, lymphocytes and leukocytes in contrast to increase in number of immature circulating cells. Hyperplasia, degeneration of glomeruli, presence of inflammatory cells and increased number of melanomacrophage aggregates, vacuolization of cell cytoplasm, hepatocyte swelling were marked in kidney and liver of fish. Ladder in, an increment of 180-200 bp of hepatic and kidney DNA, by electrophoresis were consistent with DNA damage. 10 day exposure to acid mine drainage resulted in reduction of double stranded DNA to 46.0 and 48.0 in hepatocytes and kidney cells respectively. Significant increase (P < 0.01) in tail length and percent tail DNA was evident by comet assay. The results suggest that exposure to acid mine drainage might cause irreversible damage to immune cells, tissue and DNA of fish, and this model of DNA damage may contribute in identifying novel molecular mechanism of interest for bioremediation application. PMID:27498494

  13. Denitrification potential in stream sediments impacted by acid mine drainage: effects of pH, various electron donors, and iron.

    PubMed

    Baeseman, J L; Smith, R L; Silverstein, J

    2006-02-01

    Acid mine drainage (AMD) contaminates thousands of kilometers of stream in the western United States. At the same time, nitrogen loading to many mountain watersheds is increasing because of atmospheric deposition of nitrate and increased human use. Relatively little is known about nitrogen cycling in acidic, heavy-metal-laden streams; however, it has been reported that one key process, denitrification, is inhibited under low pH conditions. The objective of this research was to investigate the capacity for denitrification in acidified streams. Denitrification potential was assessed in sediments from several Colorado AMD-impacted streams, ranging from pH 2.60 to 4.54, using microcosm incubations with fresh sediment. Added nitrate was immediately reduced to nitrogen gas without a lag period, indicating that denitrification enzymes were expressed and functional in these systems. First-order denitrification potential rate constants varied from 0.046 to 2.964 day(-1). The pH of the microcosm water increased between 0.23 and 1.49 pH units during denitrification. Additional microcosm studies were conducted to examine the effects of initial pH, various electron donors, and iron (added as ferrous and ferric iron). Decreasing initial pH decreased denitrification; however, increasing pH had little effect on denitrification rates. The addition of ferric and ferrous iron decreased observed denitrification potential rate constants. The addition of glucose and natural organic matter stimulated denitrification potential. The addition of hydrogen had little effect, however, and denitrification activity in the microcosms decreased after acetate addition. These results suggest that denitrification can occur in AMD streams, and if stimulated within the environment, denitrification might reduce acidity. PMID:16463131

  14. Denitrification potential in stream sediments impacted by acid mine drainage: Effects of pH, various electron donors, and iron

    USGS Publications Warehouse

    Baeseman, J.L.; Smith, R.L.; Silverstein, J.

    2006-01-01

    Acid mine drainage (AMD) contaminates thousands of kilometers of stream in the western United States. At the same time, nitrogen loading to many mountain watersheds is increasing because of atmospheric deposition of nitrate and increased human use. Relatively little is known about nitrogen cycling in acidic, heavy-metal-laden streams; however, it has been reported that one key process, denitrification, is inhibited under low pH conditions. The objective of this research was to investigate the capacity for denitrification in acidified streams. Denitrification potential was assessed in sediments from several Colorado AMD-impacted streams, ranging from pH 2.60 to 4.54, using microcosm incubations with fresh sediment. Added nitrate was immediately reduced to nitrogen gas without a lag period, indicating that denitrification enzymes were expressed and functional in these systems. First-order denitrification potential rate constants varied from 0.046 to 2.964 day-1. The pH of the microcosm water increased between 0.23 and 1.49 pH units during denitrification. Additional microcosm studies were conducted to examine the effects of initial pH, various electron donors, and iron (added as ferrous and ferric iron). Decreasing initial pH decreased denitrification; however, increasing pH had little effect on denitrification rates. The addition of ferric and ferrous iron decreased observed denitrification potential rate constants. The addition of glucose and natural organic matter stimulated denitrification potential. The addition of hydrogen had little effect, however, and denitrification activity in the microcosms decreased after acetate addition. These results suggest that denitrification can occur in AMD streams, and if stimulated within the environment, denitrification might reduce acidity. ?? Springer Science+Business Media, Inc. 2006.

  15. Advances in biotreatment of acid mine drainage and biorecovery of metals: 1. Metal precipitation for recovery and recycle.

    PubMed

    Tabak, Henry H; Scharp, Richard; Burckle, John; Kawahara, Fred K; Govind, Rakesh

    2003-12-01

    Acid mine drainage (AMD), an acidic metal-bearing wastewater, poses a severe pollution problem attributed to post mining activities. The metals usually encountered in AMD and considered of concern for risk assessment are arsenic, cadmium, iron, lead, manganese, zinc, copper and sulfate. The pollution generated by abandoned mining activities in the area of Butte, Montana has resulted in the designation of the Silver Bow Creek-Butte Area as the largest Superfund (National Priorities List) site in the U.S. This paper reports the results of bench-scale studies conducted to develop a resource recovery based remediation process for the clean up of the Berkeley Pit. The process utilizes selective, sequential precipitation (SSP) of metals as hydroxides and sulfides, such as copper, zinc, aluminum, iron and manganese, from the Berkeley Pit AMD for their removal from the water in a form suitable for additional processing into marketable precipitates and pigments. The metal biorecovery and recycle process is based on complete separation of the biological sulfate reduction step and the metal precipitation step. Hydrogen sulfide produced in the SRB bioreactor systems is used in the precipitation step to form insoluble metal sulfides. The average metal recoveries using the SSP process were as follows: aluminum (as hydroxide) 99.8%, cadmium (as sulfide) 99.7%, cobalt (as sulfide) 99.1% copper (as sulfide) 99.8%, ferrous iron (sulfide) 97.1%, manganese (as sulfide) 87.4%, nickel (as sulfide) 47.8%, and zinc (as sulfide) 100%. The average precipitate purity for metals, copper sulfide, ferric hydroxide, zinc sulfide, aluminum hydroxide and manganese sulfide were: 92.4, 81.5, 97.8, 95.6, 92.1 and 75.0%, respectively. The final produced water contained only calcium and magnesium and both sulfate and sulfide concentrations were below usable water limits. Water quality of this agriculturally usable water met the EPA's gold standard criterion. PMID:14669873

  16. Performance and microbial community dynamics of a sulfate-reducing bioreactor treating coal generated acid mine drainage.

    PubMed

    Burns, Andrew S; Pugh, Charles W; Segid, Yosief T; Behum, Paul T; Lefticariu, Liliana; Bender, Kelly S

    2012-06-01

    The effectiveness of a passive flow sulfate-reducing bioreactor processing acid mine drainage (AMD) generated from an abandoned coal mine in Southern Illinois was evaluated using geochemical and microbial community analysis 10 months post bioreactor construction. The results indicated that the treatment system was successful in both raising the pH of the AMD from 3.09 to 6.56 and in lowering the total iron level by 95.9%. While sulfate levels did decrease by 67.4%, the level post treatment (1153 mg/l) remained above recommended drinking water levels. Stimulation of biological sulfate reduction was indicated by a +2.60‰ increase in δ(34)S content of the remaining sulfate in the water post-treatment. Bacterial community analysis targeting 16S rRNA and dsrAB genes indicated that the pre-treated samples were dominated by bacteria related to iron-oxidizing Betaproteobacteria, while the post-treated water directly from the reactor outflow was dominated by sequences related to sulfur-oxidizing Epsilonproteobacteria and complex carbon degrading Bacteroidetes and Firmicutes phylums. Analysis of the post-treated water, prior to environmental release, revealed that the community shifted back to predominantly iron-oxidizing Betaproteobacteria. DsrA analysis implied limited diversity in the sulfate-reducing population present in both the bioreactor outflow and oxidation pond samples. These results support the use of passive flow bioreactors to lower the acidity, metal, and sulfate levels present in the AMD at the Tab-Simco mine, but suggest modifications of the system are necessary to both stimulate sulfate-reducing bacteria and inhibit sulfur-oxidizing bacteria. PMID:22083105

  17. [Effect of Zn(II) on microbial activity in anaerobic acid mine drainage treatment system with biomass as carbon source].

    PubMed

    Li, Shao-Jie; Chen, Tian-Hu; Zhou, Yue-Fei; Yue, Zheng-Bo; Jin, Jiez; Liu, Chang

    2012-01-01

    In this study, with rape straw as carbon source, anaerobic batch experiments were executed to investigate the effect of Zn (II) on the activity of sulphate reducing bacteria (SRB) in the microbial treatment of simulative acid mine drainage (AMD). The results showed that during the 60 experimental days, when initial Zn2+ concentrations were in the range of 73.7 to 196.8 mg x L(-1), SRB had high culturalbility. At the end of these experiments, pH values rose from initial 5.0 to neutral, about 96% of sulphate was reduced and the concentrations of Zn2+ reduced to 0.05 mg x L(-1). The results of Tessier sequential extraction, field emission scanning electron microscope (FE-SEM) and X-ray diffraction(XRD) showed that Zn was found to be fixed through forming organic and sulphide (mainly sphalerite) compounds. For the experiment with high Zn2+ concentration (262.97 mg x L(-1)), at the end of experiments, pH values dropped from initial 5.0 to 4.0, only 27% of sulphate was only reduced and the concentrations of Zn2+ kept in high range (25 mg x L(-1)), the activity of SRB significantly inhibited. This study indicated that: (1) Rape straw can be used as slow-release carbon source for long-term anaerobic AMD treatment; (2) Rape straw can decrease the toxicity of Zn2+ to SRB through adsorption; (3) In anaerobic AMD treatment system, Zn can be fixed by sulphide minerals with mediation of SRB. PMID:22452225

  18. Hydrogeochemical and mineralogical characteristics related to heavy metal attenuation in a stream polluted by acid mine drainage: a case study in Dabaoshan Mine, China.

    PubMed

    Zhao, Huarong; Xia, Beicheng; Qin, Jianqiao; Zhang, Jiaying

    2012-01-01

    Dabaoshan Mine, the largest mine in south China, has been developed since the 1970s. Acid mine drainage (AMD) discharged from the mine has caused severe environmental pollution and human health problems. In this article, chemical characteristics, mineralogy of ocher precipitations and heavy metal attenuation in the AMD are discussed based on physicochemical analysis, mineral analysis, sequential extraction experiments and hydrogeochemistry. The AMD chemical characteristics were determined from the initialwater composition, water-rock interactions and dissolved sulfide minerals in the mine tailings. The waters, affected and unaffected by AMD, were Ca-SO4 and Ca-HCO3 types, respectively. The affected water had a low pH, high SO4(2-) and high heavy metal content and oxidation as determined by the Fe2+/Fe3+ couple. Heavy metal and SO4(2-) contents of Hengshi River water decreased, while pH increased, downstream. Schwertmannite was the major mineral at the waste dump, while goethite and quartz were dominant at the tailings dam and streambed. Schwertmannite was transformed into goethite at the tailings dam and streambed. The sulfate ions of the secondary minerals changed from bidentate- to monodentate-complexes downstream. Fe-Mn oxide phases of Zn, Cd and Pb in sediments increased downstream. However, organic matter complexes of Cu in sediments increased further away from the tailings. Fe3+ mineral precipitates and transformations controlled the AMD water chemistry. PMID:23505864

  19. Development of a small-scale bioreactor method to monitor the molecular diversity and environmental impacts of bacterial biofilm communities from an acid mine drainage impacted creek.

    PubMed

    Cole, Michael; Wrubel, Joshua; Henegan, Patricia; Janzen, Christopher; Holt, Jack; Tobin, Tammy

    2011-10-01

    Shamokin Creek is a tributary of the Susquehanna River in central Pennsylvania that is heavily impacted by the acid mine drainage (AMD) caused by the oxidation of pyrite from the region's extensive anthracite coal mining industry. Recent studies have begun to characterize the microbial communities present in this and other AMD-impacted waters, but varying environmental conditions have complicated attempts to determine the ecological impacts of individual bacterial species within these communities. This study developed a small-scale biofilm reactor protocol that allowed us to simultaneously monitor the development of bacterial biofilm communities in AMD-impacted creek collected water using terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA genes, while assessing the impacts that the developing biofilms were having on water quality. Our analysis confirmed that the diversity and composition of these small in situ biofilm communities could be monitored using molecular methods, and indicated the possible presence of many taxa frequently found in AMD environments, including Sulfobacillus, Nitrospira, Desulfovibrio, Geobacter, and Leptothrix species. A significant increase in the total sulfate was observed in the bioreactor, and as most likely due to the accumulation of sulfur-oxidizing bacteria such as Sulfobacillus in the biofilms. This system will allow us to study the microbial ecology of Shamokin Creek through controlled experiments that will ultimately integrate microscopic, molecular, physiological and chemical analyses, and that can be utilized to develop more effective and cost-efficient environmental remediation techniques for AMD-impacted areas. PMID:21821067

  20. Comparative genomics in acid mine drainage biofilm communities reveals metabolic and structural differentiation of co-occurring archaea

    PubMed Central

    2013-01-01

    Background Metal sulfide mineral dissolution during bioleaching and acid mine drainage (AMD) formation creates an environment that is inhospitable to most life. Despite dominance by a small number of bacteria, AMD microbial biofilm communities contain a notable variety of coexisting and closely related Euryarchaea, most of which have defied cultivation efforts. For this reason, we used metagenomics to analyze variation in gene content that may contribute to niche differentiation among co-occurring AMD archaea. Our analyses targeted members of the Thermoplasmatales and related archaea. These results greatly expand genomic information available for this archaeal order. Results We reconstructed near-complete genomes for uncultivated, relatively low abundance organisms A-, E-, and Gplasma, members of Thermoplasmatales order, and for a novel organism, Iplasma. Genomic analyses of these organisms, as well as Ferroplasma type I and II, reveal that all are facultative aerobic heterotrophs with the ability to use many of the same carbon substrates, including methanol. Most of the genomes share genes for toxic metal resistance and surface-layer production. Only Aplasma and Eplasma have a full suite of flagellar genes whereas all but the Ferroplasma spp. have genes for pili production. Cryogenic-electron microscopy (cryo-EM) and tomography (cryo-ET) strengthen these metagenomics-based ultrastructural predictions. Notably, only Aplasma, Gplasma and the Ferroplasma spp. have predicted iron oxidation genes and Eplasma and Iplasma lack most genes for cobalamin, valine, (iso)leucine and histidine synthesis. Conclusion The Thermoplasmatales AMD archaea share a large number of metabolic capabilities. All of the uncultivated organisms studied here (A-, E-, G-, and Iplasma) are metabolically very similar to characterized Ferroplasma spp., differentiating themselves mainly in their genetic capabilities for biosynthesis, motility, and possibly iron oxidation. These results indicate that

  1. Prevention of Acid Mine Drainage Through Complexation of Ferric Iron by Soluble Microbial Growth Products

    NASA Astrophysics Data System (ADS)

    Pandey, S.; Yacob, T. W.; Silverstein, J.; Rajaram, H.; Minchow, K.; Basta, J.

    2011-12-01

    Acid mine drainage (AMD) is a widespread environmental problem with deleterious impacts on water quality in streams and watersheds. AMD is generated largely by the oxidation of metal sulfides (i.e. pyrite) by ferric iron. This abiotic reaction is catalyzed by conversion of ferrous to ferric iron by iron and sulfur oxidizing microorganisms. Biostimulation is currently being investigated as an attempt to inhibit the oxidation of pyrite and growth of iron oxidizing bacteria through addition of organic carbon. This may stimulate growth of indigenous communities of acidophilic heterotrophic bacteria to compete for oxygen. The goal of this research is to investigate a secondary mechanism associated with carbon addition: complexation of free Fe(III) by soluble microbial growth products (SMPs) produced by microorganisms growing in waste rock. Exploratory research at the laboratory scale examined the effect of soluble microbial products (SMPs) on the kinetics of oxidation of pure pyrite during shaker flask experiments. The results confirmed a decrease in the rate of pyrite oxidation that was dependent upon the concentration of SMPs in solution. We are using these data to verify results from a pyrite oxidation model that accounts for SMPs. This reactor model involves differential-algebraic equations incorporating total component mass balances and mass action laws for equilibrium reactions. Species concentrations determined in each time step are applied to abiotic pyrite oxidation rate expressions from the literature to determine the evolution of total component concentrations. The model was embedded in a parameter estimation algorithm to determine the reactive surface area of pyrite in an abiotic control experiment, yielding an optimized value of 0.0037 m2. The optimized model exhibited similar behavior to the experiment for this case; the root mean squared of residuals for Fe(III) was calculated to be 7.58 x 10-4 M, which is several orders of magnitude less than the actual

  2. Diversity of acidophilic prokaryotes at two acid mine drainage sites in Turkey.

    PubMed

    Aytar, Pınar; Kay, Catherine Melanie; Mutlu, Mehmet Burçin; Çabuk, Ahmet; Johnson, David Barrie

    2015-04-01

    The biodiversity of acidophilic prokaryotes in two acidic (pH 2.8-3.05) mine drainage (AMD) sites (Balya and Çan) in Turkey was examined using a combined cultivation-based and cultivation-independent approach. The latter included analyzing microbial diversity using fluorescent in situ hybridization (FISH), terminal restriction enzyme fragment length polymorphism (`T-RFLP), and quantitative PCR (qPCR). Numbers of cultivatable heterotrophic acidophilic bacteria were over an order of magnitude greater than those of chemolithotrophic acidophiles in both AMD ponds examined. Isolates identified as strains of Acidithiobacillus ferrivorans, Acidiphilium organovorum, and Ferrimicrobium acidiphilum were isolated from the Balya AMD pond, and others identified as strains of Leptospirillum ferriphilum, Acidicapsa ligni, and Acidiphilium rubrum from Çan AMD. Other isolates were too distantly related (from analysis of their 16S rRNA genes) to be identified at the species level. Archaeal diversity in the two ponds appeared to be far more limited. T-RFLP and qPCR confirmed the presence of Ferroplasma-like prokaryotes, but no archaea were isolated from the two sites. qPCR generated semiquantitative data for genera of some of the iron-oxidizing acidophiles isolated and/or detected, suggesting the order of abundance was Leptospirillum > Ferroplasma > Acidithiobacillus (Balya AMD) and Ferroplasma > Leptospirillum > Acidithiobacillus (Çan AMD). PMID:25380633

  3. Geochemical study of acid mine drainage of the Big Lick Tunnel area, Williamstown, PA

    SciTech Connect

    Tollin, S. . Dept. of Geosciences)

    1993-03-01

    Acid mine drainage in the anthracite region of Pennsylvania continues to be a significant environmental problem. This study examines the acid mine outflow from the Big Lick Tunnel, north of Williamstown, Dauphin County, Pennsylvania. The tunnel drains abandoned mines on the north side of the Big Lick Mountain. Mining ceased in the area circa 1940, and the tunnel has been in operation since that time. The water, soil and stream bed sediment geochemistry has been studied to determine their changes in chemistry over distance. The pH, TDS and metal concentrations were the primary focus. Metal concentrations were determined using an ICP unit. Data indicates the pH of the outflow to range between 6.7 and 7.3 Fe and Mn concentrations are as high as 9.7 ppb. Extensive metal precipitation ( yellow boy'') occurs within the tunnel and for several hundred meters from the mouth of the tunnel. The combination of near neutral pH and high metal concentration suggest that the drainage is in contact with highly alkaline materials prior to discharge from the tunnel. The geology of the area does not suggest bedrock as the possible source of alkaline material. One hypothesis is that the acidic water is reacting with the concrete tunnel and being neutralized. Data also suggests that the Fe precipitates much quicker than the Mn, resulting in a zonation between Fe-rich and Mn-rich sediments along the length of the drainage.

  4. Stratification of Metal and Sulphate Loads in Acid Mine Drainage Receiving Water Dams - Variables Regionalization by Cluster Analysis.

    PubMed

    Grande, J A; de la Torre, M L; Valente, T; Fernández, J P; Borrego, J; Santisteban, M; Cerón, J C; Sánchez-Rodas, D

    2015-07-01

    The Sancho Reservoir (Iberian Pyrite Belt, SW Spain) is nourished by the waters of the river Meca, which is affected by acid mine drainage (AMD) processes from the abandoned Tharsis mine. The aim of the present work is to study the hydrochemical variations in this reservoir, in order to define potential stratification processes in metal load and sulphates. A stratified sampling from the surface, with one meter deep intervals to the bottom of the dam, was performed. The results show a clear stratification of temperature, pH, electric conductivity, dissolved oxygen, metal and sulphate loads associated with depth. There is an increase of metal loads at the bottom of the reservoir, though previous studies only detect iron. The proximity between pH and aluminium suggests that water chemistry is strongly influenced by aluminium precipitation processes. This indicates the buffer effect that aluminium exercises, which precipitates as amorphous or low crystalline phases, introducing hydrogen ions to the system, while alkalinity input tends to raise pH. PMID:26163498

  5. In-situ remediation of acid mine drainage using a permeable reactive barrier in Aznalcóllar (Sw Spain).

    PubMed

    Gibert, Oriol; Rötting, Tobias; Cortina, José Luis; de Pablo, Joan; Ayora, Carlos; Carrera, Jesús; Bolzicco, José

    2011-07-15

    Following on the accident occurred in Aznalcóllar in 1998, whereby a huge amount of acid mine drainage and heavy metal-bearing pyritic sludge was released to the Agrio river valley with the subsequent contamination of groundwater, a subsurface permeable reactive barrier (PRB) was installed to mitigate the long-term impacts by the spillage. The PRB material consisted of a mixture of limestone and vegetal compost. A particular characteristic of the Agrio aquifer is its high water flow velocity (0.5-1 m/d), which may pose difficulties in its remediation using PRB technology. The present study reports the 36-month performance of the PRB. Vertical differences in water velocity were observed within the PRB, with the deeper part being slower and more effective in neutralizing pH and removing heavy metals (Zn, Al, Cu). On the other hand, partial sulfate removal appeard to be restricted to the bottom of the PRB, but with no apparent influence on downgradient water quality. The results are finally compared with the other four reported existing PRBs for AMD worldwide. PMID:21601356

  6. Hydrological modeling of a watershed affected by acid mine drainage (Odiel River, SW Spain). Assessment of the pollutant contributing areas

    NASA Astrophysics Data System (ADS)

    Galván, L.; Olías, M.; Cánovas, C. R.; Sarmiento, A. M.; Nieto, J. M.

    2016-09-01

    The Odiel watershed drains materials belonging to the Iberian Pyrite Belt, where significant massive sulfide deposits have been mined historically. As a result, a huge amount of sulfide-rich wastes are deposited in the watershed, which suffer from oxidation, releasing acidic lixiviates with high sulfate and metal concentrations. In order to reliably estimate the metal loadings along the watershed a complete series of discharge and hydrochemical data are essential. A hydrological model was performed with SWAT (Soil and Water Assessment Tool) to solve the scarcity of gauge stations along the watershed. The model was calibrated and validated from daily discharge data (from 1980 to 2010) at the outlet of the watershed, river inputs into an existent reservoir, and a flow gauge station close to the northern area of the watershed. Discharge data obtained from the hydrological model, together with analytical data, allowed the estimation of the dissolved pollutant load delivered annually by the Odiel River (e.g. 9140 t of Al, 2760 t of Zn). The pollutant load is influenced strongly by the rainfall regime, and can even double during extremely rainy years. Around 50% of total pollution comes from the Riotinto Mining District, so the treatment of Riotinto lixiviates reaching the Odiel watershed would reduce the AMD (Acid Mine Drainages) in a remarkable way, improving the water quality downstream, especially in the reservoir of Alcolea, currently under construction. The information obtained in this study will allow the optimization of remediation efforts in the watershed, in order to improve its water quality.

  7. Acidiphilium iwatense sp. nov., isolated from an acid mine drainage treatment plant, and emendation of the genus Acidiphilium.

    PubMed

    Okamura, Keiko; Kawai, Akiko; Wakao, Norio; Yamada, Takeshi; Hiraishi, Akira

    2015-01-01

    Several strains of aerobic, acidophilic, chemo-organotrophic bacteria belonging to the genus Acidiphilium were isolated from an acid mine drainage (AMD) (pH 2.2) treatment plant. 16S rRNA gene sequence comparisons showed that most of the novel isolates formed a phylogenetically coherent group (designated Group Ia) distinguishable from any of the previously established species of the genus Acidiphilium at <98% similarity. This was supported by genomic DNA-DNA hybridization assays. The Group Ia isolates were characterized phenotypically by an oval cell morphology, non-motility, growth in the range pH 2.0-5.5 (optimum pH 3.5), lack of photosynthetic pigment and the presence of C19:0 cyclo ω8c as the main component of the cellular fatty acids and ubiquinone-10 as the major quinone. On the basis of these data, the name Acidiphilium iwatense sp. nov. is proposed to accommodate the Group Ia isolates, and the description of the genus Acidiphilium is emended. The type strain of Acidiphilium iwatense sp. nov. is MS8(T) ( =NBRC 107608(T)=KCTC 23505(T)). PMID:25273513

  8. Metal reduction at low pH by a Desulfosporosinus species: implications for the biological treatment of acidic mine drainage

    SciTech Connect

    Senko, J.M.; Zhang, G.X.; McDonough, J.T.; Bruns, M.A.; Burgos, W.D.

    2009-07-01

    We isolated an acid-tolerant sulfate-reducing bacterium, GBSRB4.2, from coal mine-derived acidic mine drainage (AMD)-derived sediments. Sequence analysis of partial 16S rRNA gene of GBSRB4.2 revealed that it was affiliated with the genus Desulfosporosinus. GBSRB4.2 reduced sulfate, Fe(III) (hydr)oxide, Mn(IV) oxide, and U(VI) in acidic solutions (pH 4.2). Sulfate, Fe(III), and Mn(IV) but not U(VI) bioreduction led to an increase in the pH of acidic solutions and concurrent hydrolysis and precipitation of dissolved Al{sup 3+}. Reduction of Fe(III), Mn(IV), and U(VI) in sulfate-free solutions revealed that these metals are enzymatically reduced by GBSRB4.2. GBSRB4.2 reduced U(VI) in groundwater from a radionuclide-contaminated aquifer more rapidly at pH 4.4 than at pH 7.1, possibly due to the formation of poorly bioreducible Ca-U(VI)-CO{sub 3} complexes in the pH 7.1 groundwater.

  9. Effect of neutralized solid waste generated in lime neutralization on the ferrous ion bio-oxidation process during acid mine drainage treatment.

    PubMed

    Liu, Fenwu; Zhou, Jun; Zhou, Lixiang; Zhang, Shasha; Liu, Lanlan; Wang, Ming

    2015-12-15

    Bio-oxidation of ferrous ions prior to lime neutralization exhibits great potential for acid mine drainage (AMD) treatment, while slow ferrous ion bio-oxidation or total iron precipitation is a bottleneck in this process. In this study, neutralized solid waste (NSW) harvested in an AMD lime neutralization procedure was added as a crystal seed in AMD for iron oxyhydroxysulfate bio-synthesis. The effect of this waste on ferrous ion oxidation efficiency, total iron precipitation efficiency, and iron oxyhydroxysulfate minerals yield during ferrous ion bio-oxidation by Acidithiobacillus ferrooxidans was investigated. Ferrous ion oxidation efficiency was greatly improved by adding NSW. After 72 h incubation, total iron precipitation efficiency in treatment with 24 g/L of NSW was 1.74-1.03 times higher than in treatment with 0-12 g/L of NSW. Compared with the conventional treatment system without added NSW, the iron oxyhydroxysulfate minerals yield was increased by approximately 21.2-80.9% when 3-24 g/L of NSW were added. Aside from NSW, jarosite and schwertmannite were the main precipitates during ferrous ion bio-oxidation with NSW addition. NSW can thus serve as the crystal seed for iron oxyhydroxysulfate mineral bio-synthesis in AMD, and improve ferrous ion oxidation and total iron precipitation efficiency significantly. PMID:26150283

  10. Generation of acid mine drainage around the Karaerik copper mine (Espiye, Giresun, NE Turkey): implications from the bacterial population in the Acısu effluent.

    PubMed

    Sağlam, Emine Selva; Akçay, Miğraç; Çolak, Dilşat Nigar; İnan Bektaş, Kadriye; Beldüz, Ali Osman

    2016-09-01

    The Karaerik Cu mine is a worked-out deposit with large volumes of tailings and slags which were left around the mine site without any protection. Natural feeding of these material and run-off water from the mineralised zones into the Acısu effluent causes a serious environmental degradation and creation of acid mine drainage (AMD) along its entire length. This research aims at modelling the formation of AMD with a specific attempt on the characterisation of the bacterial population in association with AMD and their role on its occurrence. Based on 16SrRNA analyses of the clones obtained from a composite water sample, the bacterial community was determined to consist of Acidithiobacillus ferrivorans, Ferrovum myxofaciens, Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans as iron-oxidising bacteria, Acidocella facilis, Acidocella aluminiidurans, Acidiphilium cryptum and Acidiphilium multivorum as iron-reducing bacteria, and Acidithiobacillus ferrivorans, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidiphilium cryptum as sulphur-oxidising bacteria. This association of bacteria with varying roles was interpreted as evidence of a concomitant occurrence of sulphur and iron cycles during the generation of AMD along the Acısu effluent draining the Karaerik mine. PMID:27338270

  11. Thiomonas sp. CB2 is able to degrade urea and promote toxic metal precipitation in acid mine drainage waters supplemented with urea

    PubMed Central

    Farasin, Julien; Andres, Jérémy; Casiot, Corinne; Barbe, Valérie; Faerber, Jacques; Halter, David; Heintz, Dimitri; Koechler, Sandrine; Lièvremont, Didier; Lugan, Raphael; Marchal, Marie; Plewniak, Frédéric; Seby, Fabienne; Bertin, Philippe N.; Arsène-Ploetze, Florence

    2015-01-01

    The acid mine drainage (AMD) in Carnoulès (France) is characterized by the presence of toxic metals such as arsenic. Several bacterial strains belonging to the Thiomonas genus, which were isolated from this AMD, are able to withstand these conditions. Their genomes carry several genomic islands (GEIs), which are known to be potentially advantageous in some particular ecological niches. This study focused on the role of the “urea island” present in the Thiomonas CB2 strain, which carry the genes involved in urea degradation processes. First, genomic comparisons showed that the genome of Thiomonas sp. CB2, which is able to degrade urea, contains a urea genomic island which is incomplete in the genome of other strains showing no urease activity. The urease activity of Thiomonas sp. CB2 enabled this bacterium to maintain a neutral pH in cell cultures in vitro and prevented the occurrence of cell death during the growth of the bacterium in a chemically defined medium. In AMD water supplemented with urea, the degradation of urea promotes iron, aluminum and arsenic precipitation. Our data show that ureC was expressed in situ, which suggests that the ability to degrade urea may be expressed in some Thiomonas strains in AMD, and that this urease activity may contribute to their survival in contaminated environments. PMID:26441922

  12. Impact of climate change on acid mine drainage generation and contaminant transport in water ecosystems of semi-arid and arid mining areas

    NASA Astrophysics Data System (ADS)

    Anawar, Hossain Md.

    Disposal of untreated and treated mining wastes and tailings exerts a significant threat and hazard for environmental contamination including groundwater, surface water, wetlands, land, food chain and animals. In order to facilitate remediation techniques, it is important to understand the oxidation of sulfidic minerals, and the hydrolysis of the oxidation products that result in production of acid mine drainage (AMD), toxic metals, low pH, SO42- and Fe. This review has summarized the impacts of climate change on geochemical reactions, AMD generation, and water quality in semi-arid/arid mining environments. Besides this, the study included the effects of hydrological, seasonal and climate change on composition of AMD, contaminant transport in watersheds and restoration of mining sites. Different models have different types of limitations and benefits that control their adaptability and suitability of application in various mining environments. This review has made a comparative discussion of a few most potential and widely used reactive transport models that can be applied to simulate the effect of climate change on sulfide oxidation and AMD production from mining waste, and contaminant transport in surface and groundwater systems.

  13. Efflorescent sulfates from Baia Sprie mining area (Romania)--Acid mine drainage and climatological approach.

    PubMed

    Buzatu, Andrei; Dill, Harald G; Buzgar, Nicolae; Damian, Gheorghe; Maftei, Andreea Elena; Apopei, Andrei Ionuț

    2016-01-15

    The Baia Sprie epithermal system, a well-known deposit for its impressive mineralogical associations, shows the proper conditions for acid mine drainage and can be considered a general example for affected mining areas around the globe. Efflorescent samples from the abandoned open pit Minei Hill have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman and near-infrared (NIR) spectrometry. The identified phases represent mostly iron sulfates with different hydration degrees (szomolnokite, rozenite, melanterite, coquimbite, ferricopiapite), Zn and Al sulfates (gunningite, alunogen, halotrichite). The samples were heated at different temperatures in order to establish the phase transformations among the studied sulfates. The dehydration temperatures and intermediate phases upon decomposition were successfully identified for each of mineral phases. Gunningite was the single sulfate that showed no transformations during the heating experiment. All the other sulfates started to dehydrate within the 30-90 °C temperature range. The acid mine drainage is the main cause for sulfates formation, triggered by pyrite oxidation as the major source for the abundant iron sulfates. Based on the dehydration temperatures, the climatological interpretation indicated that melanterite formation and long-term presence is related to continental and temperate climates. Coquimbite and rozenite are attributed also to the dry arid/semi-arid areas, in addition to the above mentioned ones. The more stable sulfates, alunogen, halotrichite, szomolnokite, ferricopiapite and gunningite, can form and persists in all climate regimes, from dry continental to even tropical humid. PMID:26544892

  14. Odiel River, acid mine drainage and current characterisation by means of univariate analysis.

    PubMed

    Sainz, A; Grande, J A; de la Torre, M L

    2003-04-01

    Water pollution caused by sulfide oxidation responds to two geochemical processes: a natural one of temporal patterns, and the 'acid mine drainage', an accelerated process derived from the extractive activity. The Odiel River is located in Southwestern Spain; it flows to the south and into the Atlantic Ocean after joining the Tinto River near its mouth, forming a common estuary. There are three kinds of metallic mining in the Odiel River Basin: manganese, gold and silver, and pyrite mining, the latter being the most important in this basin, which is the object of this study. The main objective of the present study is centred in the characterisation of the sources responsible for the 'acid mine drainage' processes in the Odiel River Basin, through the sampling and subsequent chemical and statistical analyses of water samples collected in three types of sources: mine dumps, active mines and abandoned mines. The main conclusion is that mean pH values in the target area are remarkably lower than those in other active and abandoned mines outside of the study zone. On the contrary, mean values for heavy metal sulfates are much higher. Regarding mine dumps, mean values for pH, sulfates and heavy metals are within a similar range to those data known for areas outside the study zone. PMID:12605937

  15. Colloid Transport and Surface-Subsurface Exchange in an Acid Mine Drainage-Impacted Stream

    NASA Astrophysics Data System (ADS)

    Norvell, A. S.; Ryan, J. N.; Ren, J.; McKnight, D. M.

    2010-12-01

    Colloidal particles may provide an important control on the mobility of contaminants of concern; e.g., metals introduced into a stream from an acid mine drainage. In order to examine colloidal transport and surface-subsurface exchange, we injected synthesized ferrihydrite colloids along with a conservative tracer, bromide, into Lefthand Creek, a stream contaminated by acid mine drainage in northwestern Boulder County, Colorado. The ferrihydrite colloids were co-precipitated with yttrium to form yttrium-labelled colloids so that we could differentiate them from environmental colloids. Yttrium was measured in samples collected from the surface water and the hyporheic zone. The hyporheic zone samples were collected from a series of mini-piezometers embedded up to 1 m in depth and over a 61 m reach of the stream. A one-dimensional transient storage model (OTIS-P) was used to quantify parameters describing the transport of the conservative tracer and the colloids. Approximately 20% of the colloidal mass was lost over the 61 m reach. The loss of colloids is attributed to deposition in the shallow hyporheic zone. Laboratory column experiments demonstrated that the stream bed sediments effectively remove colloids from suspension at the pH, ionic strength, and dissolved organic matter concentration conditions occurring in Lefthand Creek.

  16. Metals and Colloids in the Hyporheic Zone of an Acid Mine Drainage-Contaminated Stream

    NASA Astrophysics Data System (ADS)

    Norvell, A. S.; Ryan, J. N.; McKnight, D. M.; Ren, J.

    2009-12-01

    A key component of human and ecological risk assessments of acid mine drainage is predicting the fate and transport of metals in receiving streams. In order to learn more about the processes that control metal removal in the stream, we studied the role of colloids and the exchange of stream water with the hyporheic zone in Lefthand Creek, a stream contaminated by acid mine drainage in northwestern Boulder County, Colorado. We installed a set of mini-piezometers in the streambed and sampled the hyporheic pore waters along a 90 m reach of the creek for metals, colloids, and other geochemical parameters in the water and sediments. We conducted tracer dilution tests to determine the extent and time scale of hyporheic exchange. The results of these investigations showed that hyporheic exchange is a significant process in the attenuation of metals. The conservative tracer (bromide) concentration reached plateaus of up to 80 % of the surface concentration at depths of 40 cm and up to only 5% at depths of 100 cm. Hydraulic residence times in the upper 40 cm range from 20 minutes at 5 cm depths to under 3 hours at 40 cm depths. Colloidal transport of some metals is significant; large fractions of lead and copper were associated with colloids composed primarily of iron and aluminum, while zinc was not significantly associated with colloids. Sequential extractions of the sediments showed that trace metals were incorporated in iron and manganese oxide coatings found on the streambed sediments.

  17. Selective recovery of dissolved Fe, Al, Cu, and Zn in acid mine drainage based on modeling to predict precipitation pH.

    PubMed

    Park, Sang-Min; Yoo, Jong-Chan; Ji, Sang-Woo; Yang, Jung-Seok; Baek, Kitae

    2015-02-01

    Mining activities have caused serious environmental problems including acid mine drainage (AMD), the dispersion of mine tailings and dust, and extensive mine waste. In particular, AMD contaminates soil and water downstream of mines and generally contains mainly valuable metals such as Cu, Zn, and Ni as well as Fe and Al. In this study, we investigated the selective recovery of Fe, Al, Cu, Zn, and Ni from AMD. First, the speciation of Fe, Al, Cu, Zn, and Ni as a function of the equilibrium solution pH was simulated by Visual MINTEQ. Based on the simulation results, the predicted pHs for the selective precipitation of Fe, Al, Cu, and Zn/Ni were determined. And recovery yield of metals using simulation is over 99 %. Experiments using artificial AMD based on the simulation results confirmed the selective recovery of Fe, Al, Cu, and Zn/Ni, and the recovery yields of Fe/Al/Cu/Zn and Fe/Al/Cu/Ni mixtures using Na2CO3 were 99.6/86.8/71.9/77.0 % and 99.2/85.7/73.3/86.1 %, respectively. After then, the simulation results were applied to an actual AMD for the selective recovery of metals, and the recovery yields of Fe, Al, Cu, and Zn using NaOH were 97.2, 74.9, 66.9, and 89.7 %, respectively. Based on the results, it was concluded that selective recovery of dissolved metals from AMD is possible by adjusting the solution pH using NaOH or Na2CO3 as neutralizing agents. PMID:25231736

  18. Acid Mine Drainage Treatment by Perlite Nanomineral, Batch and Continuous Systems

    NASA Astrophysics Data System (ADS)

    Shabani, Kumars Seifpanahi; Ardejani, Faramarz Doulati; Badii, Khshayar; Olya, Mohammad Ebrahim

    2014-03-01

    In this paper the adsorption activity of perlite nanoparticles for removal of Cu2+, Fe2+ and Mn2+ ions at Iran Sarcheshmeh copper acid mine drainage was discussed. Thus, raw perlite that provided from internal resource was modified and prepared via particles size reduction to nano scale and characterized by X-ray diffraction, X-ray fluorescence, scanning electron microscopy, transmission electron microscopy, Fourier transforms infrared and BET specific surface area analysis. The results of acid mine drainage show that pH of acid mine drainage is 5.1 and Cu2+, Fe2+ and Mn2+ ions are 10.5, 4.1 and 8.3 ppm, respectively. Firstly in the batch system the influence of adsorbent dose and temperature parameters were considered and then isothermal and kinetic models were investigated. According to the results the Langmuir isotherm and pseudo-second order kinetic model showed better correlation with the experimental data than other isotherm and kinetic models. Obtained thermodynamic parameters such as ΔG°, ΔH° and ΔS° show that the Cu2+, Fe2+ and Mn2+ ions adsorption from acid mine drainage is spontaneous and endothermic. Finally, perlite nanoparticles adsorbent was packed inside a glass column and used for the removal of heavy metals in 1, 3, 5 ml/min acid mine drainage flow rates, the breakthrough curves show that the column was saturated at 180, 240 and 315 min for different flow rates, respectively. According to the obtained results, this abundant, locally available and cheap silicate mineral showed a great efficiency for the removal of heavy metal pollutants from acid mine drainage and can be utilized for much volume of acid mine drainage or industrial scale. W pracy omówiono zdolności adsorpcyjne nano-cząsteczek perlitu wykorzystywanych o usuwania jonów Cu2+, Fe2+ i Mn2+ z kwaśnych wód kopalniach w kopalni miedzi w Sarcheshmeh w Iranie. Surowy perlit pozyskiwany ze źródeł własnych został zmodyfikowany i odpowiednio spreparowany poprzez zre-dukowanie cz

  19. A TEM study of samples from acid mine drainage systems: metal-mineral association with implications for transport

    NASA Astrophysics Data System (ADS)

    Hochella, Michael F.; Moore, Johnnie N.; Golla, Ute; Putnis, Andrew

    1999-10-01

    Transmission electron microscopy (TEM), with energy dispersive X-ray (EDX) analysis and energy filtered transmission electron microscopy/electron energy loss spectroscopy (EFTEM/EELS), as well as powder X-ray diffraction (XRD) and scanning electron microscopy (SEM), have been used to study bed sediments from two acid mine drainage (AMD) sites in western Montana, USA. TEM and associated techniques, including sample preparation via epoxy impregnation and ultramicrotome sectioning, afford the opportunity to better interpret and understand complex water-rock interactions in these types of samples. For the sample taken from the first site (Mike Horse mine), ferrihydrite is the dominant phase, Si and Zn are the most abundant elements sorbed to ferrihydrite surfaces, and Pb is notably absent from ferrihydrite association. Three additional important metal-containing phases (gahnite, hydrohetaerolite, and plumbojarosite), that were not apparent in the powder XRD pattern because of their relatively low concentration, were identified in the TEM. The presence of these phases is important, because, for example, gahnite and plumbojarosite act as sinks for Zn and Pb, respectively. Therefore, the mobility of Pb from this part of the drainage system depends on the stability of plumbojarosite and the ability of ferrihydrite to sorb the released Pb. From thermodynamic data in the literature, we predict that Pb will be released by the dissolution of plumbojarosite above a pH of 4 to 5, but it will then be recaptured by ferrihydrite if the pH continues to rise to 5.5 and higher, irrespective of competition effects from other metals. Therefore, only a relatively narrow pH window exists in which Pb can escape this portion of the system as an aqueous species. For the sample taken from the other site included in this study (the Carbonate mine), jarosite and quartz are the dominant phases. Interestingly, however, the jarosites are both Pb-poor and Pb-enriched. In addition, TEM reveals the

  20. The use of (5Z)-4-bromo-5-(bromomethylene)-2(5H)-furanone for controlling acid mine drainage through the inhibition of Acidithiobacillus ferrooxidans biofilm formation.

    PubMed

    Zhao, Yang; Chen, Peng; Nan, Wenbin; Zhi, Dejuan; Liu, Ronghui; Li, Hongyu

    2015-06-01

    The aim of this study was to determine whether acid mine drainage (AMD) production can be decreased by (5Z)-4-bromo-5-(bromomethylene)-2(5H)-furanone (furanone C-30) in the presence of Acidithiobacillus ferrooxidans (A. ferrooxidans). The effects of furanone C-30 on A. ferrooxidans biofilm production were determined by crystal violet staining and confocal laser scanning microscopy (CLSM). Biofilm-related gene expression was investigated using real-time RT-PCR. Finally, the effects of furanone C-30 on AMD production were evaluated. The results show that furanone C-30 inhibits the production of extracellular polymeric substances (EPS) and biofilm formation and significantly down-regulates the expression of biofilm-related genes. The decreased EPS production led to reduced pentlandite attachment and biofilm formation on pentlandite. Furthermore, the dissolution of both nickel and copper were inhibited by furanone C-30 without new acid formation. This study provides a promising biochemical method to control AMD. PMID:25802048

  1. Regeneration of barium carbonate from barium sulphide in a pilot-scale bubbling column reactor and utilization for acid mine drainage.

    PubMed

    Mulopo, J; Zvimba, J N; Swanepoel, H; Bologo, L T; Maree, J

    2012-01-01

    Batch regeneration of barium carbonate (BaCO(3)) from barium sulphide (BaS) slurries by passing CO(2) gas into a pilot-scale bubbling column reactor under ambient conditions was used to assess the technical feasibility of BaCO(3) recovery in the Alkali Barium Calcium (ABC) desalination process and its use for sulphate removal from high sulphate Acid Mine Drainage (AMD). The effect of key process parameters, such as BaS slurry concentration and CO(2) flow rate on the carbonation, as well as the extent of sulphate removal from AMD using the recovered BaCO(3) were investigated. It was observed that the carbonation reaction rate for BaCO(3) regeneration in a bubbling column reactor significantly increased with increase in carbon dioxide (CO(2)) flow rate whereas the BaS slurry content within the range 5-10% slurry content did not significantly affect the carbonation rate. The CO(2) flow rate also had an impact on the BaCO(3) morphology. The BaCO(3) recovered from the pilot-scale bubbling column reactor demonstrated effective sulphate removal ability during AMD treatment compared with commercial BaCO(3). PMID:22233912

  2. Arsenic Scavenging by Al-Substituted Ferrihydrites in a Circumneutral pH River Impacted by the Acid Mine Drainage of Carnoulès, Gard, France

    NASA Astrophysics Data System (ADS)

    ADRA, A.; Morin, G.; ona-Nguema, G.; Maillot, F.; Casiot, C.; Bruneel, O.

    2013-12-01

    Ferrihydrite (Fh) is a nanocrystalline ferric oxyhydroxide involved in the retention of pollutants in natural systems and in water-treatment processes. The status and properties of major chemical impurities in natural Fh is however still scarcely documented. Here we investigated the structure and reactivity of aluminum-rich Fh from river-bed sediments collected in a circumneutral river (pH 6-7) impacted by an arsenic-rich acid mine drainage (AMD). Extended X-ray absorption fine structure (EXAFS) spectroscopy at the Fe K-edge shows that Fh is the predominant mineral phase forming after neutralization of the AMD, in association with minor amount of schwertmannite transported from the AMD. EXAFS analysis indicates that Al(III) substitutes for Fe(III) ions into the Fh structure in the natural sediment samples, with local aluminum concentration within the 20-37×7 mol%Al range, in agreement with bulk chemical compositions. Synthetic aluminous Fh analogues prepared in the present study are found to be less Al-substituted (14-18×4 mol%Al). Finally, EXAFS analysis at the arsenic K-edge indicates that As(V) form similar inner-sphere surface complexes on the natural and synthetic Al-substituted Fh studied. Our results provide direct evidences for the scavenging of arsenic by natural Al- Fh, with possible implications for other pollutants in natural or engineered systems.

  3. Characterization and activity studies of highly heavy metal resistant sulphate-reducing bacteria to be used in acid mine drainage decontamination.

    PubMed

    Martins, Mónica; Faleiro, M Leonor; Barros, Raúl J; Veríssimo, A Raquel; Barreiros, M Alexandra; Costa, M Clara

    2009-07-30

    Biological treatment with sulphate-reducing bacteria (SRB) has been considered as the most promising alternative for acid mine drainage (AMD) decontamination. Normally, these wastewaters contain high concentrations of sulphate and heavy metals, so the search for SRB highly resistant to metals is extremely important for the development of a bioremediation technology. A SRB consortium resistant to high concentrations of heavy metals (Fe, Cu and Zn), similar to those typically present in AMD, was obtained among several environmental samples, from a wastewater treatment plant. The phylogenetic analysis of the dsr gene sequence revealed that this consortium contains species of SRB affiliated to Desulfovibrio desulfuricans and Desulfobulbus rhabdoformis. The results show that the presence of usually lethal concentrations of Fe (400mg/L), Zn (150 mg/L) and Cu (80 mg/L) is not toxic for the sulphate-reducing bacteria present in this sample. As a consequence, a very good efficiency in terms of sulphate reduction and metals removal was obtained. Both ethanol and lactate can be used by this inoculum as carbon source. With the other samples tested sulphate reduction was inhibited by the presence of copper and zinc. This highly metal resistant consortium will be used to inoculate a bioreactor to carry out AMD decontamination. PMID:19135795

  4. Prediction of acid mine drainage generation potential of various lithologies using static tests: Etili coal mine (NW Turkey) as a case study.

    PubMed

    Yucel, Deniz Sanliyuksel; Baba, Alper

    2016-08-01

    The Etili neighborhood in Can County (northwestern Turkey) has large reserves of coal and has been the site of many small- to medium-scale mining operations since the 1980s. Some of these have ceased working while others continue to operate. Once activities cease, the mining facilities and fields are usually abandoned without rehabilitation. The most significant environmental problem is acid mine drainage (AMD). This study was carried out to determine the acid generation potential of various lithological units in the Etili coal mine using static test methods. Seventeen samples were selected from areas with high acidic water concentrations: from different alteration zones belonging to volcanic rocks, from sedimentary rocks, and from coals and mine wastes. Static tests (paste pH, standard acid-base accounting, and net acid generation tests) were performed on these samples. The consistency of the static test results showed that oxidation of sulfide minerals, especially pyrite-which is widely found not only in the alteration zones of volcanic rocks but also in the coals and mine wastes-is the main factor controlling the generation of AMD in this mine. Lack of carbonate minerals in the region also increases the occurrence of AMD. PMID:27435620

  5. Spatio-Temporal Detection of the Thiomonas Population and the Thiomonas Arsenite Oxidase Involved in Natural Arsenite Attenuation Processes in the Carnoulès Acid Mine Drainage.

    PubMed

    Hovasse, Agnès; Bruneel, Odile; Casiot, Corinne; Desoeuvre, Angélique; Farasin, Julien; Hery, Marina; Van Dorsselaer, Alain; Carapito, Christine; Arsène-Ploetze, Florence

    2016-01-01

    The acid mine drainage (AMD) impacted creek of the Carnoulès mine (Southern France) is characterized by acid waters with a high heavy metal content. The microbial community inhabiting this AMD was extensively studied using isolation, metagenomic and metaproteomic methods, and the results showed that a natural arsenic (and iron) attenuation process involving the arsenite oxidase activity of several Thiomonas strains occurs at this site. A sensitive quantitative Selected Reaction Monitoring (SRM)-based proteomic approach was developed for detecting and quantifying the two subunits of the arsenite oxidase and RpoA of two different Thiomonas groups. Using this approach combined with FISH and pyrosequencing-based 16S rRNA gene sequence analysis, it was established here for the first time that these Thiomonas strains are ubiquitously present in minor proportions in this AMD and that they express the key enzymes involved in natural remediation processes at various locations and time points. In addition to these findings, this study also confirms that targeted proteomics applied at the community level can be used to detect weakly abundant proteins in situ. PMID:26870729

  6. Relationships between sources of acid mine drainage and the hydrochemistry of acid effluents during rainy season in the Iberian Pyrite Belt.

    PubMed

    Pérez-Ostalé, E; Grande, J A; Valente, T; de la Torre, M L; Santisteban, M; Fernández, P; Diaz-Curiel, J

    2016-01-01

    In the Iberian Pyrite Belt (IPB), southwest Spain, a prolonged and intense mining activity of more than 4,500 years has resulted in almost a hundred mines scattered through the region. After years of inactivity, these mines are still causing high levels of hydrochemical degradation in the fluvial network. This situation represents a unique scenario in the world, taking into consideration its magnitude and intensity of the contamination processes. In order to obtain a benchmark regarding the degree of acid mine drainage (AMD) pollution in the aquatic environment, the relationship between the areas occupied by the sulfide mines and the characteristics of the respective effluents after rainfall was analysed. The methodology developed, which includes the design of a sampling network, analytical treatment and cluster analysis, is a useful tool for diagnosing the contamination level by AMD in an entire metallogenic province, at the scale of each mining group. The results presented the relationship between sulfate, total dissolved solids and electrical conductivity, as well as other parameters that are typically associated with AMD and the major elements that compose the polymetallic sulfides of IPB. This analysis also indicates the low level of proximity between the affectation area and the other variables. PMID:26819390

  7. Spatio-Temporal Detection of the Thiomonas Population and the Thiomonas Arsenite Oxidase Involved in Natural Arsenite Attenuation Processes in the Carnoulès Acid Mine Drainage

    PubMed Central

    Hovasse, Agnès; Bruneel, Odile; Casiot, Corinne; Desoeuvre, Angélique; Farasin, Julien; Hery, Marina; Van Dorsselaer, Alain; Carapito, Christine; Arsène-Ploetze, Florence

    2016-01-01

    The acid mine drainage (AMD) impacted creek of the Carnoulès mine (Southern France) is characterized by acid waters with a high heavy metal content. The microbial community inhabiting this AMD was extensively studied using isolation, metagenomic and metaproteomic methods, and the results showed that a natural arsenic (and iron) attenuation process involving the arsenite oxidase activity of several Thiomonas strains occurs at this site. A sensitive quantitative Selected Reaction Monitoring (SRM)-based proteomic approach was developed for detecting and quantifying the two subunits of the arsenite oxidase and RpoA of two different Thiomonas groups. Using this approach combined with FISH and pyrosequencing-based 16S rRNA gene sequence analysis, it was established here for the first time that these Thiomonas strains are ubiquitously present in minor proportions in this AMD and that they express the key enzymes involved in natural remediation processes at various locations and time points. In addition to these findings, this study also confirms that targeted proteomics applied at the community level can be used to detect weakly abundant proteins in situ. PMID:26870729

  8. 16S rRNA and As-Related Functional Diversity: Contrasting Fingerprints in Arsenic-Rich Sediments from an Acid Mine Drainage.

    PubMed

    Fahy, Anne; Giloteaux, Ludovic; Bertin, Philippe; Le Paslier, Denis; Médigue, Claudine; Weissenbach, Jean; Duran, Robert; Lauga, Béatrice

    2015-07-01

    To gain an in-depth insight into the diversity and the distribution of genes under the particular evolutionary pressure of an arsenic-rich acid mine drainage (AMD), the genes involved in bacterial arsenic detoxification (arsB, ACR3) and arsenite oxidation (aioA) were investigated in sediment from Carnoulès (France), in parallel to the diversity and global distribution of the metabolically active bacteria. The metabolically active bacteria were affiliated mainly to AMD specialists, i.e., organisms detected in or isolated from AMDs throughout the world. They included mainly Acidobacteria and the non-affiliated "Candidatus Fodinabacter communificans," as well as Thiomonas and Acidithiobacillus spp., Actinobacteria, and unclassified Gammaproteobacteria. The distribution range of these organisms suggested that they show niche conservatism. Sixteen types of deduced protein sequences of arsenite transporters (5 ArsB and 11 Acr3p) were detected, whereas a single type of arsenite oxidase (AioA) was found. Our data suggested that at Carnoulès, the aioA gene was more recent than those encoding arsenite transporters and subjected to a different molecular evolution. In contrast to the 16S ribosomal RNA (16S rRNA) genes associated with AMD environments worldwide, the functional genes aioA, ACR3, and to a lesser extent arsB, were either novel or specific to Carnoulès, raising the question as to whether these functional genes are specific to high concentrations of arsenic, AMD-specific, or site-specific. PMID:25592635

  9. Isotope composition of sulphate in acid mine drainage as measure of bacterial oxidation

    USGS Publications Warehouse

    Taylor, B.E.; Wheeler, M.C.; Nordstrom, D.K.

    1984-01-01

    The formation of acid waters by oxidation of pyrite-bearing ore deposits, mine tailing piles, and coal measures is a complex biogeochemical process and is a serious environmental problem. We have studied the oxygen and sulphur isotope geochemistry of sulphides, sulphur, sulphate and water in the field and in experiments to identify sources of oxygen and reaction mechanisms of sulphate formation. Here we report that the oxygen isotope composition of sulphate in acid mine drainage shows a large variation due to differing proportions of atmospheric- and water-derived oxygen from both chemical and bacterially-mediated oxidation. 18O-enrichment of sulphate results from pyrite oxidation facilitated by Thiobacillus ferrooxidans in aerated environments. Oxygen isotope analysis may therefore be useful in monitoring the effectiveness of abatement programmes designed to inhibit bacterial oxidation. Sulphur isotopes show no significant fractionation between pyrite and sulphate, indicating the quantitative insignificance of intermediate oxidation states of sulphur under acid conditions. ?? 1984 Nature Publishing Group.

  10. Inhibition of acidic mine drainage using anti-bacterial substances. Technical report (Final)

    SciTech Connect

    Sherrard, J.H.; Kavanaugh, R.G.; Stroebel, P.S.; Stallard, M.L.

    1990-04-01

    Laboratory experiments were carried out to evaluate the effectiveness of antibacterial substances and antibiotics against Thiobacillus ferrooxidans, the organism responsible for bacterial mediated acidic mine drainage. Twenty-two antibiotics and two antibacterial substances were evaluated. The most promising compound, N-Serve, was evaluated further in column studies. A column study was completed using coal mine waste and hard rock mine waste spoils. Eight columns containing 7 kg of each spoil were established using varying concentrations of N-Serve applied to the spoils. The columns were leached once a week with one inch of rain (distilled water). Effluent was collected and monitored for water quality parameters. Only the highest N-Serve dose produced column leachates significantly better in quality than that of the control columns.

  11. Utilization of fly ash to improve the quality of the acid mine drainage generated by oxidation of a sulphide-rich mining waste: column experiments.

    PubMed

    Pérez-López, Rafael; Nieto, José Miguel; de Almodóvar, Gabriel Ruiz

    2007-04-01

    The production of Acid Mine Drainage (AMD) as a result of the oxidative dissolution of sulphides is one of the main pollution problems affecting natural watercourses in mining environments with sulphide-rich residues. In this work, the generation of AMD was prevented by means of the addition of fly ash to sulphide-rich residues in non-saturated column experiments. A column experiment filled with a pyrite-rich sludge with artificial irrigation leached acid drainages (pH approx. 2) containing high concentrations of sulphate, iron and other metals. However, non-saturated column experiments filled with pyritic-rich sludge and fly ash drained leachates characterized by alkaline pH (pH up to 10), low sulphate concentration, and lack of iron and other metals in solution. The pyrite oxidative dissolution at high pH, as a consequence of the leaching of fly ash, favours the metal precipitation inside the column (mainly iron), the coating of pyrite grains, and the attenuation of the oxidation process, resulting in a great improvement in the quality of the leachates. PMID:17257643

  12. Evaluation of the use of an alkali modified fly ash as a potential adsorbent for the removal of metals from acid mine drainage

    NASA Astrophysics Data System (ADS)

    Sahoo, P. K.; Tripathy, S.; Panigrahi, M. K.; Equeenuddin, Sk. Md.

    2013-09-01

    The coal fly ash (FA), mainly containing high unburnt carbon was modified by alkali hydrothermal treatment. The modified fly ash (MFA) contains lower amounts of Si and Al and has a higher surface area and pH than the untreated fly ash (FA). The objective of this study is to investigate the potential of MFA as a low cost adsorbent material for the removal of Al, Fe, Ni, Pb, Zn and Mn from acid mine drainage (AMD). The effect of dose, contact time and competing cations on the adsorption of metals was investigated. The results showed that the sorption process onto MFA was initially rapid, but slowed down thereafter. The optimum time for metal uptake was 180 min while the optimum dose of MFA for metal removal was 120 g/L. The adsorption data best fit to the Freundlich isotherm model, which demonstrates that the adsorption process is controlled by the heterogeneous nature of the adsorbent. Adsorption kinetics of Al, Fe, Ni, Pb, and Zn onto MFA follow a pseudo second-order reaction, which implies that chemisorption is the adsorption rate-limiting step for them, while for Mn it is intra-particle diffusion. Preliminary treatment of real mine drainage from Jaintia Hills coalfield indicates that MFA can be an effective and low-cost adsorbent for the treatment of AMD. The desorption data show that most of the metal ions were substantially desorbed in the acidic media, implying that the adsorbent can be regenerated and reused efficiently.

  13. TREATMENT OF ACID MINE DRAINAGE: I. EQUILIBRIUM BIOSORPTION OF ZINC AND COPPER ON NON-VIABLE ACTIVATED SLUDGE

    EPA Science Inventory

    Biosorption is potentially attractive technology for treament of acid mine drainage for separation/recovery of metal ions and mitigation of their toxicity to sulfate reducing bacteria. This study describes the equilibrium biosorptio of Zn(II) and CU(II) by nonviable activated slu...

  14. Acid mine drainage and its impact in the Black Creek watershed, Virginia

    SciTech Connect

    Yeager, J.L.; Cherry, D.S.; Bidwell, J.R.

    1995-12-31

    A one-year study was conducted to determine the impacts of acid min drainage (AMD) on the Black Creek watershed in Wise County, Virginia. Water quality, metal content of sediment and water column, soil pH, macroinvertebrate assemblages, habitat assessment and toxicity testing were used to assess the impact in the watershed. A total of 22 sites in the creek and surrounding watershed were actively monitored. This included six primary sources of AMD. Conductivity measurements > 1,000 {micro}hmos/cm were found at eight sites and pH was consistently below 6.0 at seven. Of six metals analyzed, magnesium was highest in the water column, ranging from 16.5 mg/L to 130 mg/L. Aluminum and iron were both elevated in the sediment with iron concentrations as high as 176,000 mg/kg. An increase in sediment metal concentrations was noted when progressing downstream in the creek. Of nine high wall and spoils areas sampled, soil pH was acidic in eight sites, ranging from 5.5 to 3.1. Macroinvertebrate assemblages and habitat assessment indicate that much of the creek is impacted by AMD or heavy siltation. Laboratory bioassays with Daphnia magna and Chironomus tentans have indicated both acute and chronic toxicity of water and sediment samples from selected sites within the creek. Potential recovery of the system is being addressed through a sediment purging study. Restoration options will be considered once the degree of impact is fully characterized.

  15. Sources of alkalinity and acidity along an acid mine drainage remediated stream in SE Ohio: Hewett Fork

    NASA Astrophysics Data System (ADS)

    Schleich, K. L.; Lopez, D. A.; Bowman, J. R.; Kruse, N. A.; Mackey, A. L.; VanDervort, D.; Korenowsky, R.

    2013-12-01

    In the remediation of acid mine drainage impacted streams, it is important to locate and quantify the sources of acidity and alkalinity inputs. These parameters affect the long-term recovery of the stream habitat. Previous studies have focused on treating the remediation of AMD as point source pollution, targeting the main acid seep for remediation. However, in the interest of biological and chemical recovery, it is important to understand how sources of alkalinity and acidity, throughout the stream, affect water and sediment quality. The Hewett Fork watershed in Southeastern Ohio is impacted by AMD from the AS-14 mine complex in Carbondale, Ohio. In attempts to remediate the stream, the water is being treated with a continuous alkaline input from a calcium oxide doser. While the section of watershed furthest downstream from the doser is showing signs of recovery, the water chemistry and aquatic life near the doser are still impacted. The objective of this study is to examine and model the chemistry of the tributaries of Hewett Fork to see how they contribute to the alkalinity and acidity budgets of the main stem of the stream. By examining the inputs of tributaries into the main stem, this project aims to understand processes occurring during remediation throughout the entire stream. Discharge was measured during a dry period in October, 2012 and at a high flow in May, 2013. Field parameters such as pH, TDS, DO, alkalinity and acidity were also determined. Low flow data collected during fall sampling shows variable flow along the stream path, the stream gains water from ground water at some points while it loses water at others, potentially due to variable elevation of the water table. Flow data collected during spring sampling shows that Hewett Fork is a gaining stream during that period with inputs from groundwater contributing to increasing flow downstream. When using this data to calculate the net alkalinity load along the stream, there are areas with alkaline

  16. Passive treatment of acid mine drainage in down-flow limestone systems

    SciTech Connect

    Watzlaf, G.R.

    1997-12-31

    Passive down-flow systems, consisting of compost and/or limestone layers, may be well suited for treatment of acidic mine drainage containing ferric iron and/or aluminum. Two columns were constructed and operated in the laboratory. The first column simulated a downward, vertical-flow anaerobic wetland, also referred to as successive alkalinity-producing systems (SAPS), and has received mine drainage for 97 weeks. The 0.16-m diameter column was vertically oriented and (from bottom to top) consisted of a 0.30-m thick layer of limestone, a 0.76-m thick layer of spent mushroom compost, and 0.91 m of free standing water. Water flowed vertically downward through the system. A second column, filled with only limestone, received water from the same source as the first column. This limestone column contained a 1.06-m thick layer of limestone and 0.91 m of free standing water and has received water for 55 weeks. Actual acid mine drainage (pH = 3.1, acidity = 200 mg/L (as CaCO{sub 3}), SO{sub 4}{sup 2-} = 600 mg/L, Total Fe = 10 mg/L, Mn = 14 mg/L, and Al = 18 mg/L) was collected every two weeks from a nearby abandoned deep mine and applied to these columns at a rate of 3.8 mL/min. For the compost/limestone column, effluent pH remained above 6.2 (6.2-7.9); however, pH at a depth of 0.38 m in the compost (halfway) dropped to < 4 after 28 weeks (net acidic). At the bottom of the compost pH remained > 4.5 for all 97 weeks. Alkalinity was generated by a combination of limestone dissolution and sulfate reduction. Over the 97 week period, the column generated an average of 330 mg/L of alkalinity, mostly due to limestone dissolution. Bacterial sulfate reduction displayed an ever decreasing trend, initially accounting for more than 200 mg/L of alkalinity and after 40 weeks only accounting for about 50 mg/L.

  17. Treatment of acid mine drainage with anaerobic solid-substrate reactors

    SciTech Connect

    Drury, W.J.

    1999-10-01

    Anaerobic solid-substrate reactors were used in a laboratory study of acid mine drainage treatment. Parallel systems were run continuously for 23 months, both containing a solid substrate of 2:1 (weight) cow manure and sawdust. One system had cheese whey added with the mine drainage to provide an additional electron donor source to simulate sulfate-reducing bacteria activity. Effluent pH from the reactor with whey addition was relatively constant at 6.5. Effluent pH from the reactor without whey addition dropped over time from 6.7 to approximately 5.5. Whey addition increased effluent alkalinity [550 to 700 mg/L as calcium carbonate (CaCO{sub 3}) versus 50 to 300 mg/L as CaCO{sub 3}] and sulfate removal (98 to 80% versus 60 to 40%). Sulfate removal rate with whey addition decreased over time from 250 to 120 mmol/m{sup 3}{center{underscore}dot}d, whereas it decreased from 250 to 40 mmol/m{sup 3}{center{underscore}dot}d without whey addition. Whey addition increased removal of dissolved iron, dissolved manganese, and dissolved zinc in the second part of the experiment. Copper and cadmium removals were greater than 99%, and arsenic removal was 84% without whey addition and 89% with whey addition. Effluent sulfide concentrations were approximately 1 order of magnitude greater with whey addition. A 63-day period of excessive loading permanently decreased treatment efficiency without whey addition.

  18. Characterization of novel archaeal lineages associated with acid mine drainage in Iron Mountain, CA using anaerobic cultivation and cultivation-independent genomic analysis

    NASA Astrophysics Data System (ADS)

    Baker, B. J.; Tyson, G. W.; Hugenholtz, P.; Banfield, J. F.

    2003-12-01

    Iron Mountain in northern California, contains a pyritic orebody undergoing dissolution from mining creating extremely acidic (generally ~pH 0.8), warm (>40° C), and highly concentrated metal solutions, referred to as acid mine drainage (AMD). AMD communities are limited in the number of lineages that have been associated with them. The archaeal members of the mine community, in the past, have been restricted to the Thermoplasmatales order. The various clades within the Thermoplasmatales have been named the "alphabet plasma" (ie. Aplasma through Gplasma). The majority of them remain uncultured. Anaerobic media containing ferric sulfate and glucose has been successful in enriching and maintaining members of the "alphabet plasmas". Analysis of aqueous chemistry of these cultures shows a reduction of ferric iron, suggesting a subset of these archaea are capable of iron reduction. This may be a relevant part of iron cycling in the mine previously overlooked. Recently, another deeply branched archaeal group, named WTF1102, has been identified. Completely independent of all previously identified AMD lineages, its closest relative available in present databases is to that of the euryarchaeota group referred to as VAL1, which consists entirely of uncultured and poorly represented in sequences. Screening of the community genomic library constructed from the site revealed a contiguous fragment from two shotgun clones, totaling ~4.4kb in length. These clones have been fully sequenced and contain two genes, a phosphatase and 16S rRNA. The 16S rRNA gene has a 515 bp long intron at 1102 (E. coli numbering) that contains an open reading frame which encodes for a ubitiquitin-like protein modifier. Phylogenetic analysis of the phosphotase amino acid sequence revealed it branches with that of other acidophiles, Thermoplasma and Ferroplasma. We are developing FISH probes to target the individual "alphabet plasma" and WTF1102. This work extends what we know about the diversity and

  19. Characterization of limestone reacted with acid-mine drainage in a pulsed limestone bed treatment system at the Friendship Hill National Historical Site, Pennsylvania, USA

    USGS Publications Warehouse

    Hammarstrom, J.M.; Sibrell, P.L.; Belkin, H.E.

    2003-01-01

    Armoring of limestone is a common cause of failure in limestone-based acid-mine drainage (AMD) treatment systems. Limestone is the least expensive material available for acid neutralization, but is not typically recommended for highly acidic, Fe-rich waters due to armoring with Fe(III) oxyhydroxide coatings. A new AMD treatment technology that uses CO2 in a pulsed limestone bed reactor minimizes armor formation and enhances limestone reaction with AMD. Limestone was characterized before and after treatment with constant flow and with the new pulsed limestone bed process using AMD from an inactive coal mine in Pennsylvania (pH = 2.9, Fe = 150 mg/l, acidity = 1000 mg/l CaCO3). In constant flow experiments, limestone is completely armored with reddish-colored ochre within 48 h of contact in a fluidized bed reactor. Effluent pH initially increased from the inflow pH of 2.9 to over 7, but then decreased to 6 during operation. Limestone removed from a pulsed bed pilot plant is a mixture of unarmored, rounded and etched limestone grains and partially armored limestone and refractory mineral grains (dolomite, pyrite). The ???30% of the residual grains in the pulsed flow reactor that are armored have thicker (50- to 100-??m), more aluminous coatings and lack the gypsum rind that develops in the constant flow experiment. Aluminium-rich zones developed in the interior parts of armor rims in both the constant flow and pulsed limestone bed experiments in response to pH changes at the solid/solution interface. ?? 2003 Elsevier Ltd. All rights reserved.

  20. Lipid Biomarkers and Carbon Isotope Ratios of Lipids Isolated from Acid Mine Drainage Biofilms: Dual Biosignatures for Eukaryotic Evolution and Oxygenation of Primitive Earth

    NASA Astrophysics Data System (ADS)

    Dasgupta, S.; Fang, J.; Zhang, L.; Li, J.

    2012-12-01

    Lipid analysis and carbon isotope ratios (δ13C) of lipids in biofilms in an acid mine drainage site (AMD) site in western Indiana revealed unique biogeochemical signatures of microeukaryotes, never recorded before. Dominance of photosynthetic microeukaryote Euglena was indicated by the detection of abundant phytadiene, phytol, phytanol, polyunsaturated n-alkenes, polyunsaturated fatty acids, short-chain (C25-32) wax esters (WE), ergosterol, and tocopherols. The WE were probably synthesized in mitochondria under anoxic conditions by the reverse β-oxidation pathway, whereas the sterols (ergosterol and ergosta-7,22-dien-3β-ol) were likely synthesized in the cytosol in the presence of molecular oxygen. The dual aerobic and anaerobic biosynthetic pathways of Euglena may be a response to survive the recurring anoxic and oxic conditions in primitive Earth, whereby microeukaryotes retained this mechanism of conserved compartmentalization within their physiology to evolve and diversify in extreme conditions. Hydrocarbons, including n-alkenes, phytadienes, and wax esters showed heavy δ13C values than usual. The primary cause for the 13C-enrichment can be attributed to a CO2-limiting system that exists in the AMD, which is further regulated by the pH of the AMD. Floating biofilms BF2, 4, and 6 showed more depleted δ13C values for phytadienes and n-alkenes (average of -23.6‰) as compared to benthic biofilm BF5 (average of -20.8‰), indicating that physiology plays an important role in isotopic discrimination. 13C-enriched values of the esters could result from kinetic isotope effects at two branch points (pyruvate and/or acetyl CoA) in the biosynthetic pathway. Our understanding of biogeochemical conditions in this AMD environment would allow us to identify unique sets of biosignatures that can act as a proxy in deciphering the links between eukaryotic evolutions, oxygenation of the early atmosphere, formation of BIF, and possibly iron-rich extraterrestrial

  1. Aluminium (Al) fractionation and speciation; getting closer to describing the factors influencing Al(3+) in water impacted by acid mine drainage.

    PubMed

    Chamier, Jessica; Wicht, Merrill; Cyster, Lilburne; Ndindi, Nosintu P

    2015-07-01

    Acid mine drainage (AMD) severely impacts the water chemistry of a receiving resource, changing the occurrence, speciation and toxicity of metals such as Aluminium (Al). The toxicity of Al is determined by its speciation represented by the labile monomer Al fraction or Al(3+). The purpose of the study was to combine fractionation and Visual MINTEQ speciation to calculate the effect of AMD altered water chemistry on Al speciation and Al(3+) concentration. Water in rivers impacted by AMD presented with monomeric Al (Almon) concentrations between 0.35 and 15.37mgL(-)(1) which existed almost exclusively in the toxic labile form (98%). For the reference site, Almon was less than 2% (10μgL(-1)), suggesting significantly lower Al toxicity. Principal component analysis plots illustrated that labile Al was directly related to the total Al and iron concentrations and strongly influenced by parameters such as pH, electrical conductivity, sulphate and dissolved organic carbon. Visual MINTEQ modelling was used to determine the primary Al species distribution. The dominant form of Al in AMD impacted water was AlSO4(+), which increased proportionally with the sulphate and Al(3+) concentration. Heavily impacted areas, presented with an average of 1mgmL(-)(1) Al(3+), which poses a potential human health risk. A novel centrifugal ultrafiltration method was investigated as an alternative to determining Almon to simplify the speciation of Al. Monomeric and centrifugal ultrafiltrated (<10kD) Al fractions were significantly similar (p=0.74), suggesting that ultrafiltration may present a time, energy and cost saving alternative to organic extraction of Almon. PMID:25747302

  2. Stress-Survival Gene Identification From an Acid Mine Drainage Algal Mat Community

    NASA Astrophysics Data System (ADS)

    Urbina-Navarrete, J.; Fujishima, K.; Paulino-Lima, I. G.; Rothschild-Mancinelli, B.; Rothschild, L. J.

    2014-12-01

    Microbial communities from acid mine drainage environments are exposed to multiple stressors to include low pH, high dissolved metal loads, seasonal freezing, and desiccation. The microbial and algal communities that inhabit these niche environments have evolved strategies that allow for their ecological success. Metagenomic analyses are useful in identifying species diversity, however they do not elucidate the mechanisms that allow for the resilience of a community under these extreme conditions. Many known or predicted genes encode for protein products that are unknown, or similarly, many proteins cannot be traced to their gene of origin. This investigation seeks to identify genes that are active in an algal consortium during stress from living in an acid mine drainage environment. Our approach involves using the entire community transcriptome for a functional screen in an Escherichia coli host. This approach directly targets the genes involved in survival, without need for characterizing the members of the consortium.The consortium was harvested and stressed with conditions similar to the native environment it was collected from. Exposure to low pH (< 3.2), high metal load, desiccation, and deep freeze resulted in the expression of stress-induced genes that were transcribed into messenger RNA (mRNA). These mRNA transcripts were harvested to build complementary DNA (cDNA) libraries in E. coli. The transformed E. coli were exposed to the same stressors as the original algal consortium to select for surviving cells. Successful cells incorporated the transcripts that encode survival mechanisms, thus allowing for selection and identification of the gene(s) involved. Initial selection screens for freeze and desiccation tolerance have yielded E. coli that are 1 order of magnitude more resistant to freezing (0.01% survival of control with no transcript, 0.2% survival of E. coli with transcript) and 3 orders of magnitude more resistant to desiccation (0.005% survival of

  3. Determination and evaluation of hexavalent chromium in power plant coal combustion by-products and cost-effective environmental remediation solutions using acid mine drainage.

    PubMed

    Kingston, H M Skip; Cain, Randy; Huo, Dengwei; Rahman, G M Mizanur

    2005-09-01

    The chromium species leaching from a coal combustion fly ash landfill has been characterized as well as a novel approach to treat leachates rich in hexavalent chromium, Cr(VI), by using another natural waste by-product, acid mine drainage (AMD), has been investigated during this study. It is observed that as much as 8% (approximately 10 microg g(-1) in fly ash) of total chromium is converted to the Cr(VI) species during oxidative combustion of coal and remains in the resulting ash as a stable species, however, it is significantly mobile in water based leaching. Approximately 1.23 +/- 0.01 microg g(-1) of Cr(VI) was found in the landfill leachate from permanent deposits of aged fly ash. This study also confirmed the use of AMD, which often is in close proximity to coal combustion by-product landfills, is an extremely effective and economical remediation option for the elimination of hexavalent chromium in fly ash generated leachate. Speciated isotope dilution mass spectrometry (SIDMS), as described in EPA Method 6800, was used to analytically evaluate and validate the field application of the ferrous iron and chromate chemistry in the remediation of Cr(VI) runoff. PMID:16121270

  4. Evaluation of genetic toxicity caused by acid mine drainage of coal mines on fish fauna of Simsang River, Garohills, Meghalaya, India.

    PubMed

    Talukdar, B; Kalita, H K; Baishya, R A; Basumatary, S; Sarma, D

    2016-09-01

    Fishery ecology of the Simsang River, Meghalaya is being threatened by large scale environmental degradation due to acid mine drainage (AMD) of coal mines. In the present paper, effort has been made to evaluate the genotoxicity caused due to AMD of coal mines on Channa punctata under laboratory condition through comet assay, micronucleus and chromosome aberration tests. Water samples were collected seasonally from affected and unaffected sites of the River and physico-chemical quality of water indicated low pH (4.6), high concentration of sulphates (270mgL(-1)) and iron (7.2mgL(-1)) beyond permissible limits. Polycyclic aromatic hydrocarbon (PAH) showed highest concentration of 4-ring PAH and Benzo[a]anthracene was the most important pollutant in the water collected from affected sites. The highest and the lowest mean concentrations of PAHs were estimated in monsoon and winter season, respectively. The index of DNA damage assessed by comet assay, micronucleus and chromosome aberration tests demonstrated significant differences season wise in different sampling sites. Frequency of DNA-damaged cells was found highest in the water samples collected from affected site in monsoon season. PMID:27213561

  5. Microbial Community Structure and Physiological Status of Different Types of Biofilms in an Acid Mine Drainage Site Determined by Phospholipid Analysis

    NASA Astrophysics Data System (ADS)

    Fang, J.

    2009-12-01

    A unique aspect of the acid mine drainage (AMD) system at the Green Valley coal mine site (GVS) in western Indiana is the abundance of biofims and biolaminates - stromatolites. Three major types of biofilms have been observed from the AMD site: bright green biofilm dominated by the acidophilic, oxygenic photosynthetic protozoan Euglena mutabilis, olive green biofilm of photosynthetic diatom belonging to the genus Nitzschia, and an olive-green to brownish-green filamentous algae-dominated community. These biofilms are either attached to hard substrata of the effluent channel, or floating at the surface of the effluent with abundant oxygen bubbles, with or without encrusted Fe precipitates. We analyzed lipids (hydrocarbons, wax esters, phospholipids, glycolipids, and neutral lipids) to determine the microbial biomass, community structure and physiological status of biofims collected from the GVS site. Distinctive lipid compositions were observed. The attached, red-crusted biofilms were characterized by abundant wax esters, monounsaturated fatty acids, whereas the floating biofilms by phytadienes, phytanol, polyunsaturated n-alkenes, polyunsaturated fatty acids. The accumulation of abundant wax esters probably reflects the readily available carbon and limitation of nutrients to the biofilm. Alternatively, the wax esters may be the biochemical relics of the anaerobic past of the Earth and the detection of these compounds has important implications for the evolution of eukaryotes and the paleo-environmental conditions on early Earth. This type of biochemical machine may have allowed early eukaryotes to survive recurrent anoxic conditions on early Earth.

  6. Effect of Remediation in the Chemical Evolution of Waters and Sediments Along Three Streams Impacted by Acid Mine Drainage in Southeast Ohio

    NASA Astrophysics Data System (ADS)

    Lopez, D. L.

    2005-12-01

    The chemical evolution of water and sediment along three streams impacted by acid mine drainage in southeast Ohio have been investigated (Sulphur Run in the Federal Creek watershed, Rock Run in the Monday Creek watershed, and Buffer Run in the Raccoon Creek watershed). Sulphur Run neutralizes acidic inputs naturally due to abundant carbonate lithology surrounding the stream. Rock Run and Buffer Run have been anthropogenically remediated using successive alkalinity producing wetlands (SAPS), open limestone channels, and alkaline capping of adjacent coal refuse piles. Sulphur Run has neutral to alkaline pH (which increases away from the AMD source), relatively low acidity and dissolved metals. It has the best overall water quality. However, sediment quality is poor due to mineral precipitation. At Rock Run and Buffer Run, water quality is poorer and pH is lower. Precipitation of metals is occurring at the SAPS and at the stream channel, but it is less significant due to higher solubility of metals at lower pH. Accumulation of metals in the sediments downstream of the SAPS suggests that metal-based compounds precipitated in the SAPS can be transported from there to the stream. In general, a constant supply of alkaline material (such as in watersheds rich in carbonates) may be more effective at improving water quality than passive treatment methods (e.g. SAPS), but without a means of retaining precipitates, sediment quality will be degraded by accumulation of metals in both, anthropogenically remediated AMD streams as well as in naturally remediated streams.

  7. Mobility of Po and U-isotopes under acid mine drainage conditions: an experimental approach with samples from Río Tinto area (SW Spain).

    PubMed

    Barbero, L; Gázquez, M J; Bolívar, J P; Casas-Ruiz, M; Hierro, A; Baskaran, M; Ketterer, M E

    2014-12-01

    Under acid mine drainage (AMD) conditions, the solubilities and mobilities of many elements are vastly different from conditions prevailing in most natural waters. Studies are underway in the Río Tinto area (Iberian Pyrite Belt), in order to understand the behavior and mobility of long-lived U-series radionuclides under AMD conditions. A set of leaching experiments utilizing typical country rocks from the Tinto River basin, waste rock pile composite materials, iron-rich riverbed sediments and gossan (weathered naturally rock) were performed towards this purpose. Initial leaching experiments using distilled water kept in contact with solid material for 300, 100, 50 and 1 h resulted in very low concentrations of U with (234)U/(238)U activity ratios close to equilibrium and activity concentrations of (210)Po < 0.03 mBq/g. Leaching experiments performed with sulfuric acid media (0.1 and 0.01 M), and contact times between the solid and solution for 24 h were conducted to quantify the amount of U-isotopes and (210)Po leached, and the radioactive disequilibria generated between the radionuclides in the leachate. These experiments show that Po mobility in acidic conditions (pH around 1-2) is very low, with (210)Po activity in the leachate to be 6% in average for the solid sample. By contrast, mobility of U-isotopes is higher than that of Po, around 1.2%. PMID:24308958

  8. Metals removal from an acid mine drainage: The Argo Tunnel experience

    SciTech Connect

    Cevaal, J.N.; Abel, R.J.; Rogers, S.E.

    1996-12-31

    The abandoned Argo Tunnel, located approximately 30 miles west of Denver in Idaho Springs, Colorado, is part of the Clear Creek/Central City Superfund Site and was identified as the most significant source of metals contamination to Clear Creek. More than 740 pounds of metals (including iron, manganese, zinc, copper and aluminum) are discharged from the Argo each day. During the course of bench-scale testing and preliminary design of the chemical precipitation treatment facility for the Argo Tunnel acid mine drainage, three treatment processes: conventional chemical precipitation, {open_quotes}high density sludge{close_quotes} precipitation arid membrane separation; and four chemical reagents: hydrated lime, caustic, magnesium hydroxide, and lime plus soda ash were evaluated. The result was the prepurchase of a {open_quotes}high density sludge{close_quotes} precipitation process using caustic as the reagent. The process was sized to treat the design average flow rate from the tunnel with additional capacity for potential future groundwater flows and for most surge events. The treatment facility was sited at the Argo Tunnel portal and adjacent to the Argo Mill, which is listed on the National Register of Historic Places. The nearby historic designation and strong local mining heritage led to null styled superstructure encompassing indigenous mining architecture. Improvements to the water quality within the basin include removal of most of the 740 pounds of metals the tunnel currently discharges to Clear Creek and a significant reduction in instream metal concentrations, notably zinc, manganese and copper.

  9. Evaluating remedial alternatives for an acid mine drainage stream: a model post audit.

    PubMed

    Runkel, Robert L; Kimball, Briant A; Walton-Day, Katherine; Verplanck, Philip L; Broshears, Robert E

    2012-01-01

    A post audit for a reactive transport model used to evaluate acid mine drainage treatment systems is presented herein. The post audit is based on a paired synoptic approach in which hydrogeochemical data are collected at low (existing conditions) and elevated (following treatment) pH. Data obtained under existing, low-pH conditions are used for calibration, and the resultant model is used to predict metal concentrations observed following treatment. Predictions for Al, As, Fe, H(+), and Pb accurately reproduce the observed reduction in dissolved concentrations afforded by the treatment system, and the information provided in regard to standard attainment is also accurate (predictions correctly indicate attainment or nonattainment of water quality standards for 19 of 25 cases). Errors associated with Cd, Cu, and Zn are attributed to misspecification of sorbent mass (precipitated Fe). In addition to these specific results, the post audit provides insight in regard to calibration and sensitivity analysis that is contrary to conventional wisdom. Steps taken during the calibration process to improve simulations of As sorption were ultimately detrimental to the predictive results, for example, and the sensitivity analysis failed to bracket observed metal concentrations. PMID:22074087

  10. Exploring the diversity of arsenic resistance genes from acid mine drainage microorganisms.

    PubMed

    Morgante, Verónica; Mirete, Salvador; de Figueras, Carolina G; Postigo Cacho, Marina; González-Pastor, José E

    2015-06-01

    The microbial communities from the Tinto River, a natural acid mine drainage environment, were explored to search for novel genes involved in arsenic resistance using a functional metagenomic approach. Seven pentavalent arsenate resistance clones were selected and analysed to find the genes responsible for this phenotype. Insights about their possible mechanisms of resistance were obtained from sequence similarities and cellular arsenic concentration. A total of 19 individual open reading frames were analysed, and each one was individually cloned and assayed for its ability to confer arsenic resistance in Escherichia coli cells. A total of 13 functionally active genes involved in arsenic resistance were identified, and they could be classified into different global processes: transport, stress response, DNA damage repair, phospholipids biosynthesis, amino acid biosynthesis and RNA-modifying enzymes. Most genes (11) encode proteins not previously related to heavy metal resistance or hypothetical or unknown proteins. On the other hand, two genes were previously related to heavy metal resistance in microorganisms. In addition, the ClpB chaperone and the RNA-modifying enzymes retrieved in this work were shown to increase the cell survival under different stress conditions (heat shock, acid pH and UV radiation). Thus, these results reveal novel insights about unidentified mechanisms of arsenic resistance. PMID:24801164

  11. Evaluating remedial alternatives for an acid mine drainage stream: A model post audit

    USGS Publications Warehouse

    Runkel, R.L.; Kimball, B.A.; Walton-Day, K.; Verplanck, P.L.; Broshears, R.E.

    2012-01-01

    A post audit for a reactive transport model used to evaluate acid mine drainage treatment systems is presented herein. The post audit is based on a paired synoptic approach in which hydrogeochemical data are collected at low (existing conditions) and elevated (following treatment) pH. Data obtained under existing, low-pH conditions are used for calibration, and the resultant model is used to predict metal concentrations observed following treatment. Predictions for Al, As, Fe, H +, and Pb accurately reproduce the observed reduction in dissolved concentrations afforded by the treatment system, and the information provided in regard to standard attainment is also accurate (predictions correctly indicate attainment or nonattainment of water quality standards for 19 of 25 cases). Errors associated with Cd, Cu, and Zn are attributed to misspecification of sorbent mass (precipitated Fe). In addition to these specific results, the post audit provides insight in regard to calibration and sensitivity analysis that is contrary to conventional wisdom. Steps taken during the calibration process to improve simulations of As sorption were ultimately detrimental to the predictive results, for example, and the sensitivity analysis failed to bracket observed metal concentrations.

  12. Coupling of hydrologic transport and chemical reactions in a stream affected by acid mine drainage

    USGS Publications Warehouse

    Kimball, B.A.; Broshears, R.E.; Bencala, K.E.; McKnight, Diane M.

    1994-01-01

    Experiments in St. Kevin Gulch, an acid mine drainage stream, examined the coupling of hydrologic transport to chemical reactions affecting metal concentrations. Injection of LiCl as a conservative tracer was used to determine discharge and residence time along a 1497-m reach. Transport of metals downstream from inflows of acidic, metal-rich water was evaluated based on synoptic samples of metal concentrations and the hydrologic characteristics of the stream. Transport of SO4 and Mn was generally conservative, but in the subreaches most affected by acidic inflows, transport was reactive. Both 0.1-??m filtered and particulate Fe were reactive over most of the stream reach. Filtered Al partitioned to the particulate phase in response to high instream concentrations. Simulations that accounted for the removal of SO4, Mn, Fe, and Al with first-order reactions reproduced the steady-state profiles. The calculated rate constants for net removal used in the simulations embody several processes that occur on a stream-reach scale. The comparison between rates of hydrologie transport and chemical reactions indicates that reactions are only important over short distances in the stream near the acidic inflows, where reactions occur on a comparable time scale with hydrologic transport and thus affect metal concentrations.

  13. Evaluating remedial alternatives for an acid mine drainage stream: a model post audit

    USGS Publications Warehouse

    Runkel, Robert L.; Kimball, Briant A.; Walton-Day, Katherine; Verplanck, Philip L.; Broshears, Robert E.

    2012-01-01

    A post audit for a reactive transport model used to evaluate acid mine drainage treatment systems is presented herein. The post audit is based on a paired synoptic approach in which hydrogeochemical data are collected at low (existing conditions) and elevated (following treatment) pH. Data obtained under existing, low-pH conditions are used for calibration, and the resultant model is used to predict metal concentrations observed following treatment. Predictions for Al, As, Fe, H+, and Pb accurately reproduce the observed reduction in dissolved concentrations afforded by the treatment system, and the information provided in regard to standard attainment is also accurate (predictions correctly indicate attainment or nonattainment of water quality standards for 19 of 25 cases). Errors associated with Cd, Cu, and Zn are attributed to misspecification of sorbent mass (precipitated Fe). In addition to these specific results, the post audit provides insight in regard to calibration and sensitivity analysis that is contrary to conventional wisdom. Steps taken during the calibration process to improve simulations of As sorption were ultimately detrimental to the predictive results, for example, and the sensitivity analysis failed to bracket observed metal concentrations.

  14. Biogenic catalysis in sulphide minerals' weathering processes and acid mine drainage genesis.

    PubMed

    Kušnierová, Mária; Praščáková, Mária; Nowak, Anna K; Gorazda, Katarzyna; Wzorek, Zbigniew

    2014-01-01

    Bioleaching and biogenesis are the main outputs from a large group of environmental processes participating in the natural material cycle, used in raw materials processing. Bio-oxidation reactions are the main basis for bioleaching procedures, often participating in parallel leaching processes. During the leaching processes of polycomponent sulphide substrates, the factor of process selection also plays an important role, being in direct relation to the electric properties and galvanic effect occurring between the individual components of the leaching substrate. This work gives a summary of the results of a research focused on the possibilities of using biotechnological procedures for treatment of Slovak sulphide ores. The object of the research is extraction of valuable metals, undesirable admixtures and degradation of crystal lattice of sulphides for subsequent chemical leaching processing of precious metals. The results of experiments on the existence of biogenic processes in situ on waste dumps from exploitation containing residual sulphides are also presented. The processes result in acid mine drainage water generation. These waters are strongly mineralised (over 48 g/L) and of low pH; that is why they are very caustic. The arsenic content (2.558 mg/L) in outflowing waters from old mines is high and over the limits set by the law. PMID:24445359

  15. Laboratory methods for determining the effects of bactericides on acid mine drainage

    SciTech Connect

    Shellhorn, M.A.; Rastogi, V.

    1984-12-01

    Chemolithotrophic bacteria, particularly Thiobacillus ferrooxidans, can accelerate the oxidation of iron sulfide minerals. Materials toxic to these bacteria can be used to control acid mine drainage. For practical application, it is necessary to evaluate bactericides by determining the concentration at which they are effective for the spoil or refuse on which they are to be used. Two laboratory methods have been developed. In the batch method, ten-gram aliquots of ground refuse powder treated with water or bactericide solutions were incubated in centrifuge bottles for specified periods of time in a humidity chamber. Analyses were done by extracting the samples into a measured volume of water and assaying. In the column leach method, glass columns were used containing one-kilogram samples of refuse of controlled particle size distribution to ensure uniform flow characteristics in all columns. A system for metering water or bactericide solutions into the columns at pre-determined rates was used. Column effluents were assayed weekly. In both methods, comparisons with controls were used to determine the effects of bactericide treatments. Test protocol, versatility and limitations are described using sodium lauryl sulfate as the bactericide.

  16. Hydrobiogeochemical interactions in 'anoxic' limestone drains for neutralization of acidic mine drainage

    USGS Publications Warehouse

    Robbins, E.I.; Cravotta, C.A., III; Savela, C.E.; Nord, G.L., Jr.

    1999-01-01

    Processes affecting neutralization of acidic coal mine drainage were evaluated within 'anoxic' limestone drains (ALDs). Influents had pH???3.5 and dissolved oxygen <2 mg/l. Even though effluents were near neutral (pH 6 and alkalinity acidity), two of the four ALDs were failing due to clogging. Mineral-saturation indices indicated the potential for dissolution of calcite and gypsum, and precipitation of Al3+ and Fe3+ compounds. Cleavage mounts of calcite and gypsum that were suspended within the ALDs and later examined microscopically showed dissolution features despite coatings by numerous bacteria, biofilms, and Fe-Al-Si precipitates. In the drain exhibiting the greatest flow reduction, Al-hydroxysulfates had accumulated on limestone surfaces and calcite etch points, thus causing the decline in transmissivity and dissolution. Therefore, where Al loadings are high and flow rates are low, a pre-treatment step is indicated to promote Al removal before diverting acidic mine water into alkalinity-producing materials. ?? 1998 Elsevier Science Ltd.

  17. Study of natural wetlands associated with acid mine drainage. Final research report Jul 87-Dec 90

    SciTech Connect

    Stark, L.R.

    1990-12-01

    Thirty-five natural wetlands impacted by acid mine drainage (mostly in western PA) were surveyed for abiotic and biotic parameters in relation to water quality. Using treatment efficiency and area-adjusted mass retention as wetland performance indices, correlation analyses and multiple regression techniques were employed to evaluate the influence of the wetland parameters on the mitigation of pH, Fe, Mn, and Al. Elevation of pH was correlated with large, broad, low-flow wetlands with shallow, non-channelized surface water, inlet alkalinity, and dense populations of vascular plants and bryophytes. Moderate and high iron concentrations interfered with the mitigation of pH. High Fe treatment efficiencies were correlated to low flows, large areas, broad shapes, non-channelized flows, exposed locations, a diverse and dense vegetative cover, and inlet alkalinity. Large wetlands having lush vascular plant cover and receiving alkaline waters low in total iron concentrations were implicated in significant Mn treatment. Outlet Fe concentrations were usually in compliance in wetlands that significantly lowered Mn concentrations. Algae tolerate manganese but probably do not play an active role in its elimination. Reliable indices of wetland performance include area-adjusted mass retention (for pH) and treatment efficiency (for metals).

  18. Copper electrowinning from acid mine drainage: a case study from the closed mine "Cerovo".

    PubMed

    Gorgievski, M; Bozić, D; Stanković, V; Bogdanović, G

    2009-10-30

    Copper removal from acid mine drainage originating from closed copper mine "Cerovo" RTB Bor, Serbia and containing approximately 1.3 g dm(-3) of copper and a very small amount of Fe2+/Fe3+ ions, has been successfully performed by the direct electrowinning method using either a porous copper sheet or carbon felt as the cathode. A cell with a fluidised bed of inert turbulent promoters, also used in this study, may be considered as unacceptable for the purpose view, having a cell voltage between 12 and 14 V. The cells used in the electrowinning experiments were compared in terms of cell voltage, pH and copper concentration. The results showed that it is possible to remove copper successfully from the mine waters with a high degree of electrowinning--higher than 92% and with a satisfactorily average current efficiency (>60%). Depending on the process time and the applied current, a final copper concentration less than 0.1 g dm(-3) was achieved. The specific energy consumption was approximately 7 kWh kg(-1) of deposited copper. A dense copper deposit was obtained when a three-dimensional electrode was used. PMID:19493615

  19. Stable isotope geochemistry of acid mine drainage: Experimental oxidation of pyrite

    USGS Publications Warehouse

    Taylor, B.E.; Wheeler, M.C.; Nordstrom, D.K.

    1984-01-01

    Sulfate and water from experiments in which pyrite was oxidized at a pH of 2.0 were analyzed for sulfur and oxygen stable isotopes. Experiments were conducted under both aerobic and anaerobic sterile conditions, as well as under aerobic conditions in the presence of Thiobacillus ferrooxidans, to elucidate the pathways of oxidation. Oxygen isotope fractionation between SO2-4 and H2O varied from +4.0 %. (anaerobic, sterile) to + 18.0 %. (aerobic, with T. ferrooxidans.). The oxygen isotope composition of dissolved oxygen utilized in both chemical and microbially-mediated oxidation was also determined (+11.4 %., by T. ferrooxidans; +18.4 %., chemical). Contributions of water-derived oxygen and dissolved oxygen to the sulfate produced in the oxidation of pyrite could thus be estimated. Water-derived oxygen constituted from 23 to ~ 100 percent of the oxygen in the sulfate produced in the experiments, and this closely approximates the range of contribution in natural acid mine drainage. Oxidation of sulfides in anaerobic, water-saturated environments occurs primarily by chemical oxidation pathways, whereas oxidation of sulfides in well-aerated, unsaturated zone environments occurs dominantly by microbially mediated pathways. ?? 1984.

  20. Evaluation of Fe(II) oxidation at an acid mine drainage site using laboratory-scale reactors

    NASA Astrophysics Data System (ADS)

    Brown, Juliana; Burgos, William

    2010-05-01

    Acid mine drainage (AMD) is a severe environmental threat to the Appalachian region of the Eastern United States. The Susquehanna and Potomac River basins of Pennsylvania drain to the Chesapeake Bay, which is heavily polluted by acidity and metals from AMD. This study attempted to unravel the complex relationships between AMD geochemistry, microbial communities, hydrodynamic conditions, and the mineral precipitates for low-pH Fe mounds formed downstream of deep mine discharges, such as Lower Red Eyes in Somerset County, PA, USA. This site is contaminated with high concentrations of Fe (550 mg/L), Mn (115 mg/L), and other trace metals. At the site 95% of dissolved Fe(II) and 56% of total dissolved Fe is removed without treatment, across the mound, but there is no change in the concentration of trace metals. Fe(III) oxides were collected across the Red Eyes Fe mound and precipitates were analyzed by X-ray diffraction, electron microscopy and elemental analysis. Schwertmannite was the dominant mineral phase with traces of goethite. The precipitates also contained minor amounts of Al2O3, MgO,and P2O5. Laboratory flow-through reactors were constructed to quantify Fe(II) oxidation and Fe removal over time at terrace and pool depositional facies. Conditions such as residence time, number of reactors in sequence and water column height were varied to determine optimal conditions for Fe removal. Reactors with sediments collected from an upstream terrace oxidized more than 50% of dissolved Fe(II) at a ten hour residence time, while upstream pool sediments only oxidized 40% of dissolved Fe(II). Downstream terrace and pool sediments were only capable of oxidizing 25% and 20% of Fe(II), respectively. Fe(II) oxidation rates measured in the reactors were determined to be between 3.99 x 10-8and 1.94 x 10-7mol L-1s-1. The sediments were not as efficient for total dissolved Fe removal and only 25% was removed under optimal conditions. The removal efficiency for all sediments

  1. Microbial Community Structure Responses to Long-Term Acid-Mine Drainage Contamination in a Coastal Salt Marsh

    NASA Astrophysics Data System (ADS)

    Moreau, J. W.; Zierenberg, R. A.; Banfield, J. F.

    2004-12-01

    Constructed wetlands for in situ bioremediation of metals and acid mine drainage (AMD) require the activity of sulfate-reducing bacteria (SRB) to sequester dissolved metals into metal-sulfide precipitates (e.g. Webb et al. 1998). Factors such as low pH and high dissolved [Cu] will constrain the growth of SRB (Sani et al. 2001). Unintentional stimulation of the growth of sulfuric acid-generating microbes, such as Thiomicrospira, would also decrease bioremediation efficiency. Few studies of natural wetlands under long-term forcing by AMD and metals have been performed. We characterized the microbial diversity, mineralogy and geochemistry of a contaminated salt marsh at the Richmond Field Station along the East San Francisco Bay. For over 50 years, this marsh has received pH ˜2, metal-rich groundwaters from near-surface pyrite tailings and paint and explosives manufacturers. Sediment cores (30-40 cm long) were taken from contaminated sites with pH ˜2 and ˜8. Whole-sediment analyses showed As, Cd, Cu, Se, Zn, and Pb are present at 100s of ppm (URS Corp. 2001). ICP-AES analyses of pore waters showed 10-50 ppb As. All cores contained fine-grained black muds and exhibited a noticeable sulfide odor. Transmission electron microscope studies of marsh sediments support the sequestration of metals into aggregates of nanocrystalline sulfides. Isotopic analyses of pore-water sulfate taken at several depths within cores of AMD pool (SMR-1) and tidal slough sediments (SM148-1) at pHs 2-3 and 7-8, respectively, all yielded significant negative δ 34S values (-25 to -35 ‰ ) consistent with bacterial sulfate reduction. However, values of the upper 10 cm of SMR-1 are roughly 10 ‰ heavier than seawater and support a significant contribution of dissolved sulfate from direct oxidation of pyrite tailings. 16S gene clone libraries revealed significantly different microbial community structures in cores SMR-1 and SM148-1. Roughly 40% of the library from SMR-1 consisted of

  2. Full-scale field trials of a bactericidal treatment to control acid mine drainage

    SciTech Connect

    Kleinmann, R.L.P.; Erickson, P.M.

    1982-12-01

    Sodium lauryl sulfate (SLS) is one of several anionic detergents known to be effective in inhibiting the iron-oxidizing bacterium, Thiobacillus ferrooxidans. Since T. ferrooxidans plays a critical role in determining the rate of pyrite oxidation, the Bureau of Mines has investigated the use of SLS as a method to control the formation of acid mine drainage. In previously reported pilot-scale tests, the detergent successfully controlled T. ferrooxidans and thereby reduced acid production 60-90 pct. During the past year, the Bureau of Mines has conducted five full-scale field trials at active and abandoned surface mines and coal refuse piles. The first of these field tests was at a ten acre inactive refuse pile near Beckley, West Virginia. After a three month lag period, average acidity decreased from 900 mg/l to 350 mg/l and iron decreased from over 100 mg/l to 2 mg/l. An eight acre active section of a large refuse pile was treated similarly; acidity and sulfate decreased from over 4000 mg/l to less than 100 mg/l and iron decreased from 1000 mg/l to 2 mg/l or less. At both sites, a single application was effective for about 4 months. Our other field tests have been at active and abandoned surface mines in Ohio and East Virginia. At two of the sites, SLS was applied both as a solution and in slow release rubber pellets; the latter are an attempt to provide long term control of acid drainage from inactive sites where periodic reapplication would not be feasible.

  3. A multi-isotope approach to characterize acid mine drainage in a hardrock alpine mine, Chaffe Co,Colorado.

    NASA Astrophysics Data System (ADS)

    Cordalis, D.; Williams, M. W.; Wireman, M.; Michel, R. L.; Manning, A.

    2004-12-01

    Here we present information from an innovative suite of stable, radiogenic, and cosmogenic isotopes to better understand groundwater flowpaths and groundwater-surface water interactions in an applied acid mine drainage system. Stable water isotopes, tritium, helium-tritium, sulfur-35, and uranium 234/238 ratios were analyzed from precipitation, groundwater wells, interior mine drainages, and surface waters at the Mary Murphy Mine in Colorado to determine hydrologic transport mechanisms responsible for contaminated zinc releases. Hydrometric measurements suggested a snowmelt-driven pulse of elevated zinc in adit outflow. However, mixing models using stable water isotopes showed a regional groundwater signal in the adit outflow. Tritium values of 11 to 13 TU showed a slight enrichment of bomb spike water compared to snow values of about 9 TU, suggesting an older water source as well. Helium/tritium ratios on a subset of groundwater wells suggested that average residence times of alluvial wells ranged from 2.5 to 8 years. The combination of stable water isotopes and sulfur-35 (half-life of 87 days), showed that zinc-rich waters within the mine derived from infiltrating snowmelt more than a year old. However, measurement of sulfur-35 using low-level scintillation counts was compromised at times by the presence of uranium. We were able to remove the uranium through wet chemistry procedures, improving the accuracy of S-35 measurements. The U234/U238 ratio shows promise in discriminating between acid mine drainage and acid rock drainage. Acid rock drainage shows an unaltered ratio of 1:1, while acid mine drainage is enriched relative to the 1:1 equilibrium ratio. The combination of cosmogenic and stable isotopes within and near the Mary Murphy Mine may provide a useful tool for studying interactions between groundwater and surfacewater in a fractured rock setting. Remediation techniques can be directed more appropriately, and cost effectively, by the characterization of

  4. Evaluation of the potential of indigenous calcareous shale for neutralization and removal of arsenic and heavy metals from acid mine drainage in the Taxco mining area, Mexico.

    PubMed

    Romero, F M; Núñez, L; Gutiérrez, M E; Armienta, M A; Ceniceros-Gómez, A E

    2011-02-01

    In the Taxco mining area, sulfide mineral oxidation from inactive tailings impoundments and abandoned underground mines has produced acid mine drainage (AMD; pH 2.2-2.9) enriched in dissolved concentrations (mg l⁻¹) sulfate, heavy metals, and arsenic (As): SO₄²⁻ (pH 1470-5454), zinc (Zn; 3.0-859), iron (Fe; pH 5.5-504), copper (Cu; pH 0.7-16.3), cadmium (Cd; pH 0.3-6.7), lead (Pb; pH < 0.05-1.8), and As (pH < 0.002-0.6). Passive-treatment systems using limestone have been widely used to remediate AMD in many parts of the world. In limestone-treatment systems, calcite simultaneously plays the role of neutralizing and precipitating agent. However, the acid-neutralizing potential of limestone decreases when surfaces of the calcite particles become less reactive as they are progressively coated by metal precipitates. This study constitutes first-stage development of passive-treatment systems for treating AMD in the Taxco mine area using indigenous calcareous shale. This geologic material consists of a mixture of calcite, quartz, muscovite, albite, and montmorillonite. Results of batch leaching test indicate that calcareous shale significantly increased the pH (to values of 6.6-7.4) and decreased heavy metal and As concentrations in treated mine leachates. Calcareous shale had maximum removal efficiency (100%) for As, Pb, Cu, and Fe. The most mobile metals ions were Cd and Zn, and their average percentage removal was 87% and 89%, respectively. In this natural system (calcareous shale), calcite provides a source of alkalinity, whereas the surfaces of quartz and aluminosilicate minerals possibly serve as a preferred locus of deposition for metals, resulting in the neutralizing agent (calcite) beings less rapidly coated with the precipitating metals and therefore able to continue its neutralizing function for a longer time. PMID:20523977

  5. Biosorption of metal and salt tolerant microbial isolates from a former uranium mining area. Their impact on changes in rare earth element patterns in acid mine drainage.

    PubMed

    Haferburg, Götz; Merten, Dirk; Büchel, Georg; Kothe, Erika

    2007-12-01

    The concentration of metals in microbial habitats influenced by mining operations can reach enormous values. Worldwide, much emphasis is placed on the research of resistance and biosorptive capacities of microorganisms suitable for bioremediation purposes. Using a collection of isolates from a former uranium mining area in Eastern Thuringia, Germany, this study presents three Gram-positive bacterial strains with distinct metal tolerances. These strains were identified as members of the genera Bacillus, Micrococcus and Streptomyces. Acid mine drainage (AMD) originating from the same mining area is characterized by high metal concentrations of a broad range of elements and a very low pH. AMD was analyzed and used as incubation solution. The sorption of rare earth elements (REE), aluminum, cobalt, copper, manganese, nickel, strontium, and uranium through selected strains was studied during a time course of four weeks. Biosorption was investigated after one hour, one week and four weeks by analyzing the concentrations of metals in supernatant and biomass. Additionally, dead biomass was investigated after four weeks of incubation. The maximum of metal removal was reached after one week. Up to 80% of both Al and Cu, and more than 60% of U was shown to be removed from the solution. High concentrations of metals could be bound to the biomass, as for example 2.2 mg/g U. The strains could survive four weeks of incubation. Distinct and different patterns of rare earth elements of the inoculated and non-inoculated AMD water were observed. Changes in REE patterns hint at different binding types of heavy metals regarding incubation time and metabolic activity of the cells. PMID:18072248

  6. Acid mine drainage. January 1977-January 1989 (Citations from the Selected Water Resources Abstracts data base). Report for January 1977-January 1989

    SciTech Connect

    Not Available

    1989-12-01

    This bibliography contains citations concerning the control and treatment of acid mine drainage. Techniques discussed for treating wastes with heavy metals include precipitation, cementation, ion exchange, charge membrane, ultrafiltration, ozonation, solvent extraction, and electrodialysis. The environmental impacts of acid mine drainage on rivers, streams, and lakes are also discussed. (This updated bibliography contains 344 citations, none of which are new entries to the previous edition.)

  7. Acid mine drainage. February 1989-December 1989 (Citations from the Selected Water Resources Abstracts data base). Report for February 1989-December 1989

    SciTech Connect

    Not Available

    1989-12-01

    This bibliography contains citations concerning the control and treatment of acid mine drainage. Techniques discussed for treating wastes with heavy metals include precipitation, cementation, ion exchange, charge membrane, ultrafiltration, ozonation, solvent extraction, and electrodialysis. The environmental impacts of acid mine drainage on rivers, streams, and lakes are also discussed. (This updated bibliography contains 54 citations, all of which are new entries to the previous edition.)

  8. Acid mine drainage. January 1977-January 1989 (Citations from the Selected Water Resources Abstracts data base). Report for January 1977-January 1989

    SciTech Connect

    Not Available

    1989-01-01

    This bibliography contains citations concerning the control and treatment of acid mine drainage. Techniques discussed for treating wastes with heavy metals include precipitation, cementation, ion exchange, charge membrane, ultrafiltration, ozonation, solvent extraction, and electrodialysis. The environmental impacts of acid mine drainage on rivers, streams, and lakes are also discussed. (This updated bibliography contains 344 citations, 78 of which are new entries to the previous edition.)

  9. Bibliography for acid-rock drainage and selected acid-mine drainage issues related to acid-rock drainage from transportation activities

    USGS Publications Warehouse

    Bradley, Michael W.; Worland, Scott C.

    2015-01-01

    Acid-rock drainage occurs through the interaction of rainfall on pyrite-bearing formations. When pyrite (FeS2) is exposed to oxygen and water in mine workings or roadcuts, the mineral decomposes and sulfur may react to form sulfuric acid, which often results in environmental problems and potential damage to the transportation infrastructure. The accelerated oxidation of pyrite and other sulfidic minerals generates low pH water with potentially high concentrations of trace metals. Much attention has been given to contamination arising from acid mine drainage, but studies related to acid-rock drainage from road construction are relatively limited. The U.S. Geological Survey, in cooperation with the Tennessee Department of Transportation, is conducting an investigation to evaluate the occurrence and processes controlling acid-rock drainage and contaminant transport from roadcuts in Tennessee. The basic components of acid-rock drainage resulting from transportation activities are described and a bibliography, organized by relevant categories (remediation, geochemical, microbial, biological impact, and secondary mineralization) is presented.

  10. Vegetation succession and impacts of biointrusion on covers used to limit acid mine drainage.

    PubMed

    Smirnova, Evgeniya; Bussière, Bruno; Tremblay, Francine; Bergeron, Yves

    2011-01-01

    A cover with capillary barrier effects (CCBE) was constructed in 1998 on the abandoned Lorraine mine tailings impoundment to limit the generation of acid mine drainage. The Ministry of Natural Resources and Fauna of Quebec (MRNF) is responsible for the site and for all restoration works on it, including CCBE construction. The CCBE is made up of three layers: a 0.3-m layer of sand used as a support and capillary break layer; a moisture-retaining layer with a thickness of 0.5 m (this layer is constructed of a nonplastic silt); and a 0.3-m sand and gravel layer on top. The main objective of the CCBE is to maintain one (or more) of the layers at a high degree of water saturation to impede oxygen migration and acid generation. Vegetation succession on the Lorraine CCBE results in an improvement in soil conditions, leading to the installation of deep-rooted species, which could represent a risk to CCBE long-term performance. Hence, the characterization of vegetation succession is an important aspect of the monitoring strategy for the Lorraine CCBE. Species occurrence was documented, and depth of tree roots was measured by excavation on a regular basis. Eight functional groups of plants were identified; herbaceous plants were the most abundant ecological plant groups. Tree ring counts confirmed that tree colonization started the year of CCBE construction (1999). Of the 11 tree species identified, the most abundant were poplar (Populus spp.), paper birch (Betula payrifera Marsh.), black spruce (Picea mariana Mill.), and willow (Salix spp.). Significant differences in occurrence related to environmental conditions were observed for most functional groups. Root excavation showed that tree roots exceeded the depth of the protective layer and started to reach the moisture-retaining layer; in 2008, root average depth was 0.4 m and the maximal root depth was 1.7 m. PMID:21488502

  11. Iron-mineral accretion from acid mine drainage and its application in passive treatment

    PubMed Central

    Florence, K.; Sapsford, D.J.; Johnson, D.B.; Kay, C.M.; Wolkersdorfer, C.

    2016-01-01

    ABSTRACT This study demonstrates substantial removal of iron (Fe) from acid mine drainage (pH ≈3) in a passive vertical flow reactor (VFR) with an equivalent footprint of 154 m2 per L/s mine water and residence times of >23 h. Average Fe removal rate was 67% with a high of 85% over the 10-month trial. The fraction of Fe passing a 0.22 µm filter (referred to here as Fe-filt) was seen to be removed in the VFR even when Fe(II) was absent, indicating that the contribution of microbial Fe(II) oxidation and precipitation was not the dominant removal mechanism in the VFR. Removal rates of Fe-filt in the VFR were up to 70% in residence times as low as 8 h compared with laboratory experiments where much smaller changes in Fe-filt were observed over 60 h. Centrifugation indicated that 80–90% of the influent Fe had particle sizes <35 nm. Together with analyses and geochemical modelling, this suggests that the Fe-filt fraction exists as either truly aqueous (but oversaturated) Fe(III) or nanoparticulate Fe(III) and that this metastability persists. When the water was contacted with VFR sludge, the Fe-filt fraction was destabilized, leading to an appreciably higher removal of this fraction. Heterogeneous precipitation and/or aggregation of nanoparticulate Fe(III) precipitates are considered predominant removal mechanisms. Microbial analyses of the mine water revealed the abundance of extracellular polymeric substance-generating Fe-oxidizing bacterium ‘Ferrovum myxofaciens’, which may aid the removal of iron and explain the unusual appearance and physical properties of the sludge. PMID:26675674

  12. The role of anaerobic bacteria in the neutralization of acid mine drainage. [Desulfovibrio

    SciTech Connect

    Bell, P.E.

    1988-01-01

    In contrast to the acidic water column, the sediments underlying Lake Anna, which receives acid mine drainage, are circumneutral and contain 1-4 meq alkalinity/L. Indirect fluorescent antibody counts of a methanogen (strain CA) and a sulfate reducer (Desulfovibrio strain SM) demonstrated that these organisms were present in the sediments at numbers of approximately 10{sup 6} bacteria/mL sediment. Anaerobic heterotrophs in the sediments underlying the acidified arm of the lake outnumbered anaerobic heterotrophs in a non-acidified arm of the lake. A major storm event resulted in the deposition of 11 cm of oxidized, acidic new sediment material over the older circumneutral sediments. The Eh in the new sediments decreased by 200 mV within one week after the storm event. The pH and alkalinity increased even in the 1-cm layer by two weeks after the storm and products of sulfate reduction (acid volatile sulfide) increased at three weeks after the storm. This suggests that biological processes other than sulfate reduction were responsible for the initial buffering of these sediments. Laboratory experiments using the sulfate reducer and two anaerobes (also isolated from the sediments) suggested that alkalinity production during sulfate reduction decreases with decreasing carbon concentration. Generation of alkalinity was found not to be a simple function of sulfate reduction or of iron reduction. The generation of alkalinity was found to be a function of the carbon source, and concentration, organisms present, and mineral phase formed. Iron reduction rates in the sediments of Contrary Creek ranged from 4.9-27.8 mM/m{sup 2}-sediment-day. Alkalinity was produced in the floc layer in the absence of sulfate reduction. Iron reduction could be responsible for the mineralization of 15-90% of the carbon input to this system.

  13. Effects of soluble ferri-hydroxide complexes on microbial neutralization of acid mine drainage.

    PubMed

    Bilgin, A Azra; Silverstein, JoAnn; Hernandez, Mark

    2005-10-15

    Heterotrophic respiration of ferric iron by Acidiphilium cryptum was investigated in anoxic microcosms with initial media pH values from 1.5 to 3.5. No organic carbon consumption or iron reduction was observed with an initial pH of 1.5, indicating that A. cryptum may not be capable of iron respiration at this pH. Significant iron reduction was observed at pH 2.5 and 3.5, with different effects. When the initial pH was 3.5, pH increased to 4.7-5.5 over 60 days of incubation with simultaneous production of 0.4 g L(-1) Fe2+. However, at an initial pH of 2.5, no significant change in pH was observed during iron respiration, although the accumulation of soluble ferrous iron was significantly higher, averaging 1.1 g L(-1) Fe2+. The speciation of the ferric iron electron acceptor may explain these results. At pH values of 3.5 and higher, precipitated ferric hydroxide Fe- (OH)3 would have been the primary source of ferric iron, with reduction resulting in net production of OH- ions and the significant increases in media pH observed. However at pH 2.5, soluble complexes, FeOH2+ and Fe(OH)2+, may have been the more prevalent electron acceptors, and the alkalinity generated by reduction of complexed iron was low. The existence of charged ferri-hydroxide complexes at pH 2.5 was verified by voltammetry. Results suggest that initiation of bacterial iron reduction may result in neutralization of acid mine drainage. However, this effect is extremely sensitive to iron speciation within a relatively small and critical pH range. PMID:16295843

  14. An evaluation of trace element release associated with acid mine drainage

    NASA Astrophysics Data System (ADS)

    Sullivan, Patrick J.; Yelton, Jennifer L.

    1988-12-01

    The determination of trace element release from geologic materials, such as oil shale and coal overburden, is important for proper solid waste management planning. The objective of this study was to determine a correlation between trace element residency and concentration to trace element release using the following methods: (1) sequential selective dissolution for determining trace element residencies, (2) toxicity characteristic leaching procedure (TCLP), and (3) humidity cell weathering study simulating maximum trace element release. Two eastern oil shales were used, a New albany shale that contains 4.6 percent pyrite, and a Chattanooga shale that contains 1.5 percent pyrite. Each shale was analyzed for elemental concentrations by soluble, adsorbed, organic, carbonate, and sulfide phases. All leachates were analyzed to determine total trace element concentrations. The results of the selective dissolution studies show that each trace element has a unique distribution between the various phases. Thus, it is possible to predict trace element release based on trace element residency. The TCLP results show that this method is suitable for assessing soluble trace element release but does not realistically assess potential hazards. The results of the humidity cell studies do demonstrate a more reasonable method for predicting trace element release and potential water quality hazards. The humidity cell methods, however, require months to obtain the required data with a large number of analytical measurements. When the selective dissolution data are compared to the trace element concentrations in the TCLP and humidity cell leachates, it is shown that leachate concentrations are predicted by the selective dissolution data. Therefore, selective dissolution may represent a rapid method to assess trace element release associated with acid mine drainage.

  15. Iron-mineral accretion from acid mine drainage and its application in passive treatment.

    PubMed

    Florence, K; Sapsford, D J; Johnson, D B; Kay, C M; Wolkersdorfer, C

    2016-06-01

    This study demonstrates substantial removal of iron (Fe) from acid mine drainage (pH ≈3) in a passive vertical flow reactor (VFR) with an equivalent footprint of 154 m(2) per L/s mine water and residence times of >23 h. Average Fe removal rate was 67% with a high of 85% over the 10-month trial. The fraction of Fe passing a 0.22 µm filter (referred to here as Fe-filt) was seen to be removed in the VFR even when Fe(II) was absent, indicating that the contribution of microbial Fe(II) oxidation and precipitation was not the dominant removal mechanism in the VFR. Removal rates of Fe-filt in the VFR were up to 70% in residence times as low as 8 h compared with laboratory experiments where much smaller changes in Fe-filt were observed over 60 h. Centrifugation indicated that 80-90% of the influent Fe had particle sizes <35 nm. Together with analyses and geochemical modelling, this suggests that the Fe-filt fraction exists as either truly aqueous (but oversaturated) Fe(III) or nanoparticulate Fe(III) and that this metastability persists. When the water was contacted with VFR sludge, the Fe-filt fraction was destabilized, leading to an appreciably higher removal of this fraction. Heterogeneous precipitation and/or aggregation of nanoparticulate Fe(III) precipitates are considered predominant removal mechanisms. Microbial analyses of the mine water revealed the abundance of extracellular polymeric substance-generating Fe-oxidizing bacterium 'Ferrovum myxofaciens', which may aid the removal of iron and explain the unusual appearance and physical properties of the sludge. PMID:26675674

  16. Evaluating remedial alternatives for an acid mine drainage stream: Application of a reactive transport model

    USGS Publications Warehouse

    Runkel, R.L.; Kimball, B.A.

    2002-01-01

    A reactive transport model based on one-dimensional transport and equilibrium chemistry is applied to synoptic data from an acid mine drainage stream. Model inputs include streamflow estimates based on tracer dilution, inflow chemistry based on synoptic sampling, and equilibrium constants describing acid/base, complexation, precipitation/dissolution, and sorption reactions. The dominant features of observed spatial profiles in pH and metal concentration are reproduced along the 3.5-km study reach by simulating the precipitation of Fe(III) and Al solid phases and the sorption of Cu, As, and Pb onto freshly precipitated iron-(III) oxides. Given this quantitative description of existing conditions, additional simulations are conducted to estimate the streamwater quality that could result from two hypothetical remediation plans. Both remediation plans involve the addition of CaCO3 to raise the pH of a small, acidic inflow from ???2.4 to ???7.0. This pH increase results in a reduced metal load that is routed downstream by the reactive transport model, thereby providing an estimate of post-remediation water quality. The first remediation plan assumes a closed system wherein inflow Fe(II) is not oxidized by the treatment system; under the second remediation plan, an open system is assumed, and Fe(II) is oxidized within the treatment system. Both plans increase instream pH and substantially reduce total and dissolved concentrations of Al, As, Cu, and Fe(II+III) at the terminus of the study reach. Dissolved Pb concentrations are reduced by ???18% under the first remediation plan due to sorption onto iron-(III) oxides within the treatment system and stream channel. In contrast, iron(III) oxides are limiting under the second remediation plan, and removal of dissolved Pb occurs primarily within the treatment system. This limitation results in an increase in dissolved Pb concentrations over existing conditions as additional downstream sources of Pb are not attenuated by

  17. Effects of acid mine drainage on water, sediment and associated benthic macroinvertebrate communities

    SciTech Connect

    Rutherford, L.G.; Cherry, D.S.; Dobbs, M.G.; Cairns, J. Jr.; Zipper, C.E.

    1995-12-31

    The toxic constituents of abandoned mined land (AML) discharges (acidic pH, heavy metals, total suspended solids) are extremely toxic to aquatic life . Studies were undertaken to ascertain environmental impacts to the upper Powell River, Lee and Wise Counties, Va. These impacts included disruptions in physical water quality, sediment quality, altered benthic macroinvertebrate assemblages, and toxicity of the water column and sediments from short-term impairment bioassays, and the potential to bioaccumulate selected metals (Al, Fe, Mn, P, Zn, Cu, Mg, S, Ni, Cd) by periphyton and resident bivalves. Water chemistry and macroinvertebrate assemblages were collected at upstream control, just below acid mine drainage and other downstream sites. Selected trace metal concentrations (Al, Fe, Mn, P, Zn, Cu, Mg, S, Ni, Cd) were determined for water, sediment and resident bivalves using ICP-AES. Acidic pH ranged from 2.15--3.3 at three AML-influenced seeps and varied from 6.4--8.0 at reference stations. At one AML-influenced creek, acidic pH conditions worsened from summer to fall and eradicated aquatic life throughout a 1.5 km stretch of that creek as it flowed into another creek. An additional dilution of 3.4 km in the second creek was needed to nearly neutralize the acidic pH problem. Conductivity (umhos/cm) ranged from 32--278 at reference sites and from 245--4,180 at AML-impact sites. Benthic macroinvertebrate abundance and taxon richness were essentially eliminated in the seeps or reached numbers of 1 -3 taxa totaling < 10 organisms relative to reference areas where richness values were 12--17 and comprised 300--977 organisms. Concentrations of Fe, Al, Mg and Cu and Zn were highest in the environmentally stressed stations of low pH and high conductivity relative to the reference stations. Iron was, by far, the element in highest concentration followed by Al and Mg.

  18. Application of a Depositional Facies Model to an Acid Mine Drainage Site▿ †

    PubMed Central

    Brown, Juliana F.; Jones, Daniel S.; Mills, Daniel B.; Macalady, Jennifer L.; Burgos, William D.

    2011-01-01

    Lower Red Eyes is an acid mine drainage site in Pennsylvania where low-pH Fe(II) oxidation has created a large, terraced iron mound downstream of an anoxic, acidic, metal-rich spring. Aqueous chemistry, mineral precipitates, microbial communities, and laboratory-based Fe(II) oxidation rates for this site were analyzed in the context of a depositional facies model. Depositional facies were defined as pools, terraces, or microterracettes based on cm-scale sediment morphology, irrespective of the distance downstream from the spring. The sediments were composed entirely of Fe precipitates and cemented organic matter. The Fe precipitates were identified as schwertmannite at all locations, regardless of facies. Microbial composition was studied with fluorescence in situ hybridization (FISH) and transitioned from a microaerophilic, Euglena-dominated community at the spring, to a Betaproteobacteria (primarily Ferrovum spp.)-dominated community at the upstream end of the iron mound, to a Gammaproteobacteria (primarily Acidithiobacillus)-dominated community at the downstream end of the iron mound. Microbial community structure was more strongly correlated with pH and geochemical conditions than depositional facies. Intact pieces of terrace and pool sediments from upstream and downstream locations were used in flowthrough laboratory reactors to measure the rate and extent of low-pH Fe(II) oxidation. No change in Fe(II) concentration was observed with 60Co-irradiated sediments or with no-sediment controls, indicating that abiotic Fe(II) oxidation was negligible. Upstream sediments attained lower effluent Fe(II) concentrations compared to downstream sediments, regardless of depositional facies. PMID:21097582

  19. Impact of acid mine drainages on surficial waters of an abandoned mining site.

    PubMed

    García-Lorenzo, M L; Marimón, J; Navarro-Hervás, M C; Pérez-Sirvent, C; Martínez-Sánchez, M J; Molina-Ruiz, José

    2016-04-01

    Weathering of sulphide minerals produces a great variety of efflorescences of soluble sulphate salts. These minerals play an important role for environmental pollution, since they can be either a sink or a source for acidity and trace elements. This paper aims to characterise surface waters affected by mining activities in the Sierra Minera of Cartagena-La Union (SE, Spain). Water samples were analysed for trace metals (Zn, Cd, Pb, Cu, As and Fe), major ions (Na(+), K(+), Ca(2+) and Mg(2+)) and anions (F(-), Cl(-), NO3 (-), CO3 (2-), SO4 (2-)) concentrations and were submitted to an "evaporation-precipitation" experiment that consisted in identifying the salts resulting from the evaporation of the water aliquots sampled onsite. Mineralogy of the salts was studied using X-ray diffraction and compared with the results of calculations using VISUAL MINTEQ. The study area is heavily polluted as a result of historical mining and processing activities that has produced large amount of wastes characterised by a high trace elements content, acidic pH and containing minerals resulting from the supergene alteration of the raw materials. The mineralogical study of the efflorescences obtained from waters shows that magnesium, zinc, iron and aluminium sulphates predominate in the acid mine drainage precipitates. Minerals of the hexahydrite group have been quantified together with minerals of the rozenite group, alunogen and other phases such as coquimbite and copiapite. Calcium sulphates correspond exclusively to gypsum. In a semiarid climate, such as that of the study area, these minerals contribute to understand the response of the system to episodic rainfall events. MINTEQ model could be used for the analysis of waters affected by mining activities but simulation of evaporation gives more realistic results considering that MINTEQ does not consider soluble hydrated salts. PMID:26347422

  20. Natural Versus Anthropogenic Remediation of Streams Impacted by Acid Mine Drainage in Southeast Ohio

    NASA Astrophysics Data System (ADS)

    Clinton, T.; Lopez, D. L.

    2004-12-01

    Three streams that have been affected by acid mine drainage in southeast Ohio have been investigated (Sulphur Run in the Federal Creek watershed, Rock Run in the Monday Creek watershed, and Buffer Run in the Raccoon Creek watershed). Sulphur Run neutralizes acidic inputs naturally due to its strong buffering capacity acquired from water-rock interactions with the abundant carbonate lithology surrounding the stream. Rock Run and Buffer Run have been anthropogenically remediated using successive alkalinity producing wetlands, open limestone channels, and alkaline capping of adjacent coal refuse piles. The objective of this study is to compare the water quality evolution of the three streams. For this purpose, water and sediment samples were collected for chemical analysis and in-situ flow rate, alkalinity, acidity, pH, dissolved oxygen, and conductivity were measured. Preliminary results reveal that the pH of Sulphur Run, which never drops below 6.7, increases steadily along the flow path. Downstream of the remediation sites, the pH of Rock Run and Buffer Run is always below 4 and declines along the flow path, possibly due to a combination of additional acidic inputs downstream from the main source and the oxidation of metals, leading to hydrolysis reactions that produce additional hydrogen protons. The net alkalinity of Sulphur Run increases steadily downstream, reflecting the effectiveness of a continuous supply of alkaline material at neutralizing acidic inputs. Both Buffer Run and Rock Run are net acidic, suggesting that armoring of the open limestone channels by metal precipitates is impeding the recovery of water quality. The early results indicate that remediation schemes that do not mimic nature by providing a long term, steady supply of alkaline material appear to be ineffective.

  1. Geochemical characterisation of seepage and drainage water quality from two sulphide mine tailings impoundments: Acid mine drainage versus neutral mine drainage

    USGS Publications Warehouse

    Heikkinen, P.M.; Raisanen, M.L.; Johnson, R.H.

    2009-01-01

    Seepage water and drainage water geochemistry (pH, EC, O2, redox, alkalinity, dissolved cations and trace metals, major anions, total element concentrations) were studied at two active sulphide mine tailings impoundments in Finland (the Hitura Ni mine and Luikonlahti Cu mine/talc processing plant). The data were used to assess the factors influencing tailings seepage quality and to identify constraints for water treatment. Changes in seepage water quality after equilibration with atmospheric conditions were evaluated based on geochemical modelling. At Luikonlahti, annual and seasonal changes were also studied. Seepage quality was largely influenced by the tailings mineralogy, and the serpentine-rich, low sulphide Hitura tailings produced neutral mine drainage with high Ni. In contrast, drainage from the high sulphide, multi-metal tailings of Luikonlahti represented typical acid mine drainage with elevated contents of Zn, Ni, Cu, and Co. Other factors affecting the seepage quality included weathering of the tailings along the seepage flow path, process water input, local hydrological settings, and structural changes in the tailings impoundment. Geochemical modelling showed that pH increased and some heavy metals were adsorbed to Fe precipitates after net alkaline waters equilibrated with the atmosphere. In the net acidic waters, pH decreased and no adsorption occurred. A combination of aerobic and anaerobic treatments is proposed for Hitura seepages to decrease the sulphate and metal loading. For Luikonlahti, prolonged monitoring of the seepage quality is suggested instead of treatment, since the water quality is still adjusting to recent modifications to the tailings impoundment.

  2. The influence of acidic mine and spoil drainage on water quality in the mid-Wales area.

    PubMed

    Fuge, R; Laidlaw, I M; Perkins, W T; Rogers, K P

    1991-06-01

    The many abandoned base metal mines of the mid-Wales ore field are sources of extensive pollution. Some of the mineralised veins contain large amounts of pyrite and marcasite and oxidative weathering of these produces sulphuric acid resulting in very acidic mine drainage waters. In addition, the spoil tips associated with these mines can contain abundant iron sulphides. Drainage waters from these sources have pH values as low as 2.6 and are heavily contaminated with metals such as Al, Zn, Cd and Ni.Two of the main rivers of the area, the Rheidol and Ystwyth, intercept heavily contaminated acidic drainage which has a marked effect on water quality. The Rheidol contains over 100 μg L(-1) Zn for 16 km downstream of the acid water influx. This level is over three times the recommended EEC limit for Zn in salmonoid waters of low hardness. PMID:24202839

  3. Maxi-Acid{trademark}: In-situ amelioration of acid mine drainage problems. Topical report, February 1, 1995--February 1, 1996

    SciTech Connect

    1997-08-01

    The development of technologies to ameliorate acid mine drainage problems has had few successes. Most often, once acid mine drainage exists, the company responsible develops treatment programs to make sure that water resources and land are not contaminated by the acid mine drainage. These treatments usually result in significant costs and do not result in a cure to the problem. Much effort and money has been spent on the problems associated with acid mine drainage. However, it appears that most of the meaningful breakthroughs have come in the area of treatment of the results of the problem (i.e. water treatment). There have been few breakthroughs in the prevention of acid formation. Most of the work associated with the prevention of acid formation has dealt with the prevention of oxidation using grouting to seal mines, removing oxygen from the system or preventing water flow into the mines, using bactericides to eliminate the catalytic effect of Thiobacillus ferrooxidans, and modifying the mining methods. The Maxi-Acid{trademark} technology takes a different approach to the problem. A site treated using Maxi-Acid won`t be expected to generate acid mine drainage for a number of years, if ever. The application of Maxi-Acid is expected to eliminate continuous treatment of acid waters discharged from applicable mine sites. The work accomplished to date includes characterization of overburden materials that contain large quantities of potential acidity, and preliminary evaluations of the acid-generating capabilities of materials containing high levels of potential acidity (pyritic materials) using humidity cells. This research effort is in the preliminary stages. To date, a number of interesting findings have been made that could be used to contribute to the elimination of acid mine drainage. However, the concepts that are expected to have the most significant impact on the formation of acid mine drainage have not yet been substantiated.

  4. Characterization and Localization of Iron-Oxidizing Proteins in Acid Mine Drainage Biofilms

    NASA Astrophysics Data System (ADS)

    Chan, C. S.; Thelen, M. P.; Hwang, M.; Banfield, J. F.

    2005-12-01

    As molecular geomicrobiologists, we are interested in the microbially-produced molecules that effect geochemical transformations, particularly proteins involved in lithotrophic energy generation. We have identified two such proteins produced by Leptospirillum group II microbes, which dominate biofilms floating on acidic waters in the Richmond Mine at Iron Mountain, CA. Leptospirillum generates energy by iron oxidation, producing the ferric iron catalyst responsible for pyrite oxidation, subsequent acid generation and toxic metal release. We have shown that a small (~16 kDa) soluble protein, cytochrome-579, extracted from environmental biofilm samples is capable of iron oxidation in vitro, consistent with prior studies on similar cytochromes from L. ferriphilum and ferrooxidans (Blake et al., 1993; Hart et al., 1991). The abundance of cyt579 and its ability to oxidize iron makes it a key link between microbial metabolism and acid mine drainage. Given the importance of cyt579 in biofilm sustenance as well as acid generation, we want to understand more about its distribution and also the architecture of the biofilm environment in which it functions. Using transmission electron microscopy (TEM) on ultrathin sections, we observe biofilms as thin as 15 microns with densely-packed cells in a matrix of polymers. To localize cyt579 in the biofilm, we purified the protein and developed antibodies for immunolabeling. The antibodies were shown to be highly specific for cyt579 using Western blots of whole biofilm lysate. Fluorescence- and gold-labeled secondary antibodies were used to visualize immunolabeled biofilms by confocal laser scanning microscopy and TEM, respectively. Preliminary results suggest that the cytochrome is on the bacterial cell surface or in the periplasm but not throughout the biofilm, as we had postulated due to the abundance of cytochrome in extracellular fractions of biofilm samples. These localization studies will be helpful in determining the

  5. Evaluating remedial alternatives for an acid mine drainage stream: application of a reactive transport model.

    PubMed

    Runkel, Robert L; Kimball, Briant A

    2002-03-01

    A reactive transport model based on one-dimensional transport and equilibrium chemistry is applied to synoptic data from an acid mine drainage stream. Model inputs include streamflow estimates based on tracer dilution, inflow chemistry based on synoptic sampling, and equilibrium constants describing acid/base, complexation, precipitation/dissolution, and sorption reactions. The dominant features of observed spatial profiles in pH and metal concentration are reproduced along the 3.5-km study reach by simulating the precipitation of Fe(III) and Al solid phases and the sorption of Cu, As, and Pb onto freshly precipitated iron(III) oxides. Given this quantitative description of existing conditions, additional simulations are conducted to estimate the streamwater quality that could result from two hypothetical remediation plans. Both remediation plans involve the addition of CaCO3 to raise the pH of a small, acidic inflow from approximately 2.4 to approximately 7.0. This pH increase results in a reduced metal load that is routed downstream by the reactive transport model, thereby providing an estimate of post-remediation water quality. The first remediation plan assumes a closed system wherein inflow Fe(II) is not oxidized by the treatment system; under the second remediation plan, an open system is assumed, and Fe(II) is oxidized within the treatment system. Both plans increase instream pH and substantially reduce total and dissolved concentrations of Al, As, Cu, and Fe(II+III) at the terminus of the study reach. Dissolved Pb concentrations are reduced by approximately 18% under the first remediation plan due to sorption onto iron(III) oxides within the treatment system and stream channel. In contrast, iron(III) oxides are limiting under the second remediation plan, and removal of dissolved Pb occurs primarily within the treatment system. This limitation results in an increase in dissolved Pb concentrations over existing conditions as additional downstream sources of

  6. Biology of the caddisfly oligostomis ocelligera (Trichoptera: Phryganeidae) inhabiting acidic mine drainage in Pennsylvania

    USGS Publications Warehouse

    Redell, L.A.; Gall, W.K.; Ross, R.M.; Dropkin, D.S.

    2009-01-01

    Oligostomis ocelligera (a phryganeid caddisfly) is reported for the first time from a degraded lotic systema first-order stream in north-central Pennsylvania that was severely impacted by acid mine drainage. Although uncommonly collected and poorly known, O. ocelligera maintained a substantial population in the mine discharge, free of competition from Plecoptera, Ephemeroptera, and other species of Trichoptera. It thrived under conditions of very low pH (2.583.13), high concentrations of sulfate (542 mg/L) and heavy metals (Fe 12 mg/L, Mn 14 mg/L, Al 16 mg/L), and a nearly uniform springbrook-like temperature regime. More than 350 larvae were collected from deposits of leaves and woody detritus in a pool 0.32 km downstream from the mine entrance over a two-year period. Measurement of head-capsule widths yielded a multimodal distribution with five peaks, corresponding to five instars, in conformity with Dyar's Law. Eighty-three egg masses were observed along the stream channel from 3 June to 12 November at a mean distance of 6.1 cm above the water surface in moist, protected locations such as under moss mats or in crevices of logs. Eggs began hatching by mid-summer, first-instar larvae were present in samples from AugustOctober, all five instars were represented in October, instars IIV were still present in December, but only instars IV and V were represented in samples collected from March to July. The extended periods of oviposition and larval recruitment, together with a remarkably protracted flight period of six months (29 April30 October), led to the conclusion that the population of O. ocelligera at the mine site exhibited an asynchronous univoltine life cycle. Measurement of the width of the anterior border of the frontoclypeal apotome confirmed Wiggins' proposal that this metric is useful for distinguishing final instar larvae of O. ocelligera from its only Nearctic congener, O. pardalis. Occupied pupal cases were found embedded in sodden logs from 8 April

  7. Study of Lateral Gene Transfer in an Acid Mine Drainage Community Enabled by Comparative Genomics

    NASA Astrophysics Data System (ADS)

    Hugenholtz, P.; Croft, L.; Tyson, G. W.; Baker, B. J.; Detter, C.; Richardson, P. M.; Banfield, J. F.

    2002-12-01

    Lateral gene transfer (LGT) is thought to play a crucial role in the ecology and evolution of prokaryotes. We are investigating the role of LGT in an acid mine drainage community hosted in a pyrite-dominated metal sulfide deposit at the Richmond mine at Iron Mountain, CA. Due to biologically-mediated pyrite dissolution, the prevailing conditions within the mine are extremely low pH (< 1.0), very high ionic concentrations (molar concentrations of iron sulfate and mM concentrations of arsenic, copper and zinc), and moderate to high temperatures (30 to >50 C). These conditions are thought to largely isolate the community from potential external gene donors since naked DNA, phage and prokaryotes native to neutral pH habitats do not persist at pH <1.0 precluding an external influx of genes by transformation, transduction and conjugation, respectively. Microbial communities exist in several distinct habitats within Richmond mine including biofilms (subaqueous slime streamers and subaerial slimes) and cells attached directly to pyrite granules. This, however, belies an unusual simplicity in community composition. All communities investigated to date comprise only a handful of phylogenetically distinct organisms, typically dominated by the iron-oxidizing genera Leptospirillum and Ferroplasma. We have undertaken a community genomics analysis of a subaerial biofilm dominated by a Leptospirillum population to facilitate the study of LGT in this type of environment. The genome of Ferroplasma acidarmanus fer1, a minor component of the target community (but a major component of other Richmond mine communities), has been sequenced. Comparative genome analyses indicate that F. acidarmanus and the ancestor of two acidophilic Thermoplasma species belonging to the Euryarchaeota have traded many genes with phylogenetically remote acidophilic Sulfolobus species (Crenarchaeota). The putatively transferred sets of Sulfolobus genes in Ferroplasma and the Thermoplasma ancestor are distinct

  8. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    2000-10-01

    This project evaluated the technical, economic and environmental feasibility of filling abandoned underground mine voids with coal combustion byproducts. Success was measured in terms of technical feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). Phase 1 of the project was completed in September 1995 and was concerned with the development of the grout and a series of predictive models. These models were verified through the Phase II field phase and will be further verified fin the large scale field demonstration of Phase III. The verification allows the results to be packaged in such a way that the technology can be easily adapted to different site conditions. Phase II was successfully completed with 1000 cubic yards of grout being injected into Anker Energy's Fairfax mine. The grout flowed over 600 feet from a single injection borehole. The grout achieved a compressive strength of over 1000 psi (twice the level that is needed to guarantee subsidence control). Phase III was a full scale test at Anker's eleven acre Longridge mine site. The CCB grout replaced what was an open mine void with a solid so that the groundwater tends to flow around and through the pillars rather than through the previously mined areas. The project has demonstrated that CCBs can be successfully disposed in underground mines. Additionally, the project has shown that filling an abandoned underground mine with CCBs can lead to the reduction and elimination of environmental problems associated with underground mining such as acid mine drainage and subsidence. The filling of the Longridge Mine with 43,000 cubic yards of CCB grout resulted in a 97% reduction in acid mine drainage coming from the mine.

  9. Adsorption compared with sulfide precipitation as metal removal processes from acid mine drainage in a constructed wetland

    NASA Astrophysics Data System (ADS)

    Machemer, Steven D.; Wildeman, Thomas R.

    1992-01-01

    Metal removal processes from acid mine drainage were studied in an experimental constructed wetland in the Idaho Springs-Central City mining district of Colorado. The wetland was designed to passively remove heavy metals from the mine drainage flowing from the Big Five Tunnel. Concurrent studies were performed in the field on the waters flowing from the wetland and in the laboratory on the wetland substrate. Both studies suggest that there is competition for organic adsorption sites among Fe, Cu, Zn and Mn. Iron and Cu appear to be more strongly adsorbed than Zn and Mn. The adsorption of metals varies with the fluctuation of pH in the outflow water. Also indicated by field and laboratory studies is the microbial reduction of sulfate with a corresponding increase in the sulfide concentration of the water. As sulfide is generated. Cu and Zn are completely removed. The field results suggest that upon start up of a constructed wetland, the adsorption of dissolved metals onto organic sites in the substrate material will be an important process. Over time, sulfide precipitation becomes the dominant process for metal removal from acid mine drainage.

  10. Current Performance of an Aerobic Passive Wetlands Treating Acid Mine Drainage Flow From Underground Mine Seals at Moraine State Park, Butler County, Pennsylvania

    NASA Astrophysics Data System (ADS)

    Winter, J. A.; Fredrick, K.

    2008-12-01

    Coal mining was conducted in the area of Moraine State Park prior to the establishing the park and associated Lake Arthur. A total of 69 underground mine entries were sealed during the 1960's to the early 1970's along the proposed northern shore of Lake Arthur. Seals were constructed using a flyash/cement mixture that was pumped into boreholes to place bulkheads in the mine entries, then filling between the bulkheads, and injecting grout into the adjacent strata to form a grout curtain. During 1979 and 1980, a study was performed by the United States Department of the Interior, Bureau of Mines, to determine the long term effectiveness of the underground mine sealing and reclamation work. Not all seals were successful. One of these mine entry seals was leaking and depositing iron hydroxides on the shoreline. During 1995-96, a passive wetlands treatment system was designed and constructed to treat an acid mine drainage (amd) discharge emanating from one of these sealed mines. The system consists of a primary settling pond, a cattail vegetated pond, and a final polishing pond prior to discharge to Lake Arthur. The design life of the system was estimated at twelve years. After twelve years it was believed the precipitate in the ponds would need to be removed and the system rehabilitated to continue treating the amd discharge. A maintenance plan was considered, however only minimal maintaining of the area was implemented. Six sets of water quality samples were collected and analyzed for standard amd parameters of alkalinity, acidity, pH, iron, manganese, aluminum, sulfate, and total suspended solids. Precipitation data and flow rates were collected and an analysis was done to determine if flow varied seasonally. The water quality data was compared to flow and precipitation amounts. Sludge precipitate samples were collected from the first settling pond to estimate the deposition rate and to determine how long the ponds can continue to function before they would require

  11. Quantifying Heavy Metals Sequestration by Sulfate-Reducing Bacteria in an Acid Mine Drainage-Contaminated Natural Wetland

    PubMed Central

    Moreau, John W.; Fournelle, John H.; Banfield, Jillian F.

    2013-01-01

    Bioremediation strategies that depend on bacterial sulfate reduction for heavy metals remediation harness the reactivity of these metals with biogenic aqueous sulfide. Quantitative knowledge of the degree to which specific toxic metals are partitioned into various sulfide, oxide, or other phases is important for predicting the long-term mobility of these metals under environmental conditions. Here we report the quantitative partitioning into sedimentary biogenic sulfides of a suite of metals and metalloids associated with acid mine drainage contamination of a natural estuarine wetland for over a century. PMID:23487496

  12. Depth-dependent geochemical and microbiological gradients in Fe(III) deposits resulting from coal mine-derived acid mine drainage

    PubMed Central

    Brantner, Justin S.; Haake, Zachary J.; Burwick, John E.; Menge, Christopher M.; Hotchkiss, Shane T.; Senko, John M.

    2014-01-01

    We evaluated the depth-dependent geochemistry and microbiology of sediments that have developed via the microbially-mediated oxidation of Fe(II) dissolved in acid mine drainage (AMD), giving rise to a 8–10 cm deep “iron mound” that is composed primarily of Fe(III) (hydr)oxide phases. Chemical analyses of iron mound sediments indicated a zone of maximal Fe(III) reducing bacterial activity at a depth of approximately 2.5 cm despite the availability of dissolved O2 at this depth. Subsequently, Fe(II) was depleted at depths within the iron mound sediments that did not contain abundant O2. Evaluations of microbial communities at 1 cm depth intervals within the iron mound sediments using “next generation” nucleic acid sequencing approaches revealed an abundance of phylotypes attributable to acidophilic Fe(II) oxidizing Betaproteobacteria and the chloroplasts of photosynthetic microeukaryotic organisms in the upper 4 cm of the iron mound sediments. While we observed a depth-dependent transition in microbial community structure within the iron mound sediments, phylotypes attributable to Gammaproteobacterial lineages capable of both Fe(II) oxidation and Fe(III) reduction were abundant in sequence libraries (comprising ≥20% of sequences) from all depths. Similarly, abundances of total cells and culturable Fe(II) oxidizing bacteria were uniform throughout the iron mound sediments. Our results indicate that O2 and Fe(III) reduction co-occur in AMD-induced iron mound sediments, but that Fe(II)-oxidizing activity may be sustained in regions of the sediments that are depleted in O2. PMID:24860562

  13. The impact of acid mine drainage on the methylmercury cycling at the sediment-water interface in Aha Reservoir, Guizhou, China.

    PubMed

    He, Tianrong; Zhu, Yuzhen; Yin, Deliang; Luo, Guangjun; An, Yanlin; Yan, HaiYu; Qian, Xiaoli

    2015-04-01

    The methylmercury (MeHg) cycling at water-sediment interface in an acid mine drainage (AMD)-polluted reservoir (Aha Reservoir) and a reference site (Hongfeng Reservoir) were investigated and compared. Both reservoirs are seasonal anoxic and alkaline. The concentrations of sulfate, sulfide, iron, and manganese in Aha Reservoir were enriched compared to the reference levels in Hongfeng reservoir due to the AMD input. It was found that the MeHg accumulation layer in Aha Reservoir transitioned from the top sediment layer in winter to the water-sediment interface in spring and then to the overlying water above sediment in summer. It supported the assumption that spring methylation activity may start in sediments and migrate into the water column with seasonal variation. The weaker methylation in sediment during spring and summer was caused by the excessive sulfide (∼15-20 μM) that reduced the bioavailability of mercury, while sulfate reduction potential was in the optimal range for the methylation in the overlying water. This led to a transport flux of MeHg from water to sediment in spring and summer. In contrast, such inversion of MeHg accumulation layer did not occur in Hongfeng Reservoir. The sulfate reduction potential was in the optimal range for the methylation in top sediment, and dissolved MeHg was positively related to sulfide in pore water of Hongfeng Reservoir (r = 0.67, p < 0.001). This result suggested that accumulation of MeHg in lake water and cycling of MeHg at sediment-water interface associate with some sensitive environmental factors, such as sulfur. PMID:25483970

  14. Distribution and migration of heavy metals in soil and crops affected by acid mine drainage: Public health implications in Guangdong Province, China.

    PubMed

    Liao, Jianbo; Wen, Zewei; Ru, Xuan; Chen, Jundong; Wu, Haizhen; Wei, Chaohai

    2016-02-01

    Acid mine drainages (AMD) contain high concentrations of heavy metals, and their discharges into streams and rivers constitute serious environmental problems. This article examines the effects of AMD on soil, plant and human health at Dabaoshan mine in Guangdong Province, China. Although the large scale mining was stopped in 2011, the heavy metal pollution in soil continues to endanger crops and human health in that region. The objectives of this study were to elucidate distribution and migration of Cd, Cu, Zn, As and Pb and associated health implications to local inhabitants. We collected and analyzed 74 crop samples including 28 sugarcane, 30 vegetables, 16 paddy rice and the corresponding soil samples, used correlation and linear relationship for transformation process analysis, and applied carcinogenic and non-carcinogenic risk for hazard evaluation. Results showed that the local soils were heavily polluted with Cd, Cu and As (especially for Cd) and the mean Igeo value was as high as 3.77. Cadmium, Cu, and Zn in rice and vegetables were comparable with those found four years ago, while As and Pb in edible parts were 2 to 5 times lower than before. The root uptake of Cd and Zn contributed mainly to their high concentrations in crops due to high exchangeable fraction of soil, while leafy vegetables accumulated elevated As and Pb contents mainly due to the atmospheric deposition. Metal concentrations in sugarcane roots were higher than those in rice and vegetable roots. The risk assessment for crops consumption showed that the hazard quotients values were of 21 to 25 times higher than the threshold level for vegetables and rice, indicating a potential non-carcinogenic risk to the consumers. The estimated mean total cancer risk value of 0.0516 more than 100 times exceeded the USEPA accepted risk level of 1×10(-4), indicating unsuitability of the soil for cultivating the food crops. Therefore, the local agricultural and the land-use policies need to be reevaluated

  15. Recognition of a Biofilm at the Sediment-Water Interface of AN Acid Mine Drainage-Contaminated Stream, and its Role in Controlling Iron Flux

    NASA Astrophysics Data System (ADS)

    Boult, Stephen; Johnson, Nicholas; Curtis, Charles

    1997-03-01

    Material collected over a month on plates attached to the bed of the Afon Goch, Anglesey, a stream highly contaminated by acid mine drainage (AMD), was either examined intact by electron microscopy or suspended and cultured to reveal the presence of microbiota. Certain of the aerobic microbiota were identified, the genus Pseudomonas formed the commonest isolate and cultures of Serratia plymuthica were grown in order to compare the biofilms formed with the material collected in the Afon Goch. The material at the sediment-water interface of the Afon Goch was of similar underlying morphology to that of the cultured biofilms. However, the former had a superficial granular coating of equidimensional (60-100 nm) and evenly spaced iron rich particles (determined by X-ray microanalysis). The sediment-water interface of this AMD-contaminated stream is therefore best described as a highly contaminated biofilm. Evidence from previous work suggests that the streambed is active in iron removal from the water column. The intimate association of iron with microbiota at the streambed, therefore, implies that iron flux prediction may not be possible from physical and chemical data alone but requires knowledge of biofilm physiology and ecology.Microbially mediated metal precipitation, both by single bacteria and by biofilms, has been reported elsewhere but mass balance considerations suggest that this explanation cannot hold good for the large amounts of iron hydroxide depositing from waters of the prevalent pH and redox status. Filtered stream water analyses indicate the presence of colloidal iron hydroxide and also its removal downstream where ochreous (iron hydroxide rich) material accumulates. The process of iron immobilization is likely to be the attraction and physical trapping of colloidal iron hydroxide by extracellular polymeric substances (EPS) which constitute the matrix of biofilms.

  16. Depth-dependent geochemical and microbiological gradients in Fe(III) deposits resulting from coal mine-derived acid mine drainage.

    PubMed

    Brantner, Justin S; Haake, Zachary J; Burwick, John E; Menge, Christopher M; Hotchkiss, Shane T; Senko, John M

    2014-01-01

    We evaluated the depth-dependent geochemistry and microbiology of sediments that have developed via the microbially-mediated oxidation of Fe(II) dissolved in acid mine drainage (AMD), giving rise to a 8-10 cm deep "iron mound" that is composed primarily of Fe(III) (hydr)oxide phases. Chemical analyses of iron mound sediments indicated a zone of maximal Fe(III) reducing bacterial activity at a depth of approximately 2.5 cm despite the availability of dissolved O2 at this depth. Subsequently, Fe(II) was depleted at depths within the iron mound sediments that did not contain abundant O2. Evaluations of microbial communities at 1 cm depth intervals within the iron mound sediments using "next generation" nucleic acid sequencing approaches revealed an abundance of phylotypes attributable to acidophilic Fe(II) oxidizing Betaproteobacteria and the chloroplasts of photosynthetic microeukaryotic organisms in the upper 4 cm of the iron mound sediments. While we observed a depth-dependent transition in microbial community structure within the iron mound sediments, phylotypes attributable to Gammaproteobacterial lineages capable of both Fe(II) oxidation and Fe(III) reduction were abundant in sequence libraries (comprising ≥20% of sequences) from all depths. Similarly, abundances of total cells and culturable Fe(II) oxidizing bacteria were uniform throughout the iron mound sediments. Our results indicate that O2 and Fe(III) reduction co-occur in AMD-induced iron mound sediments, but that Fe(II)-oxidizing activity may be sustained in regions of the sediments that are depleted in O2. PMID:24860562

  17. Microbial reduction of ferric iron oxyhydroxides as a way for remediation of grey forest soils heavily polluted with toxic metals by infiltration of acid mine drainage

    NASA Astrophysics Data System (ADS)

    Georgiev, Plamen; Groudev, Stoyan; Spasova, Irena; Nicolova, Marina

    2015-04-01

    The abandoned uranium mine Curilo is a permanent source of acid mine drainage (AMD) which steadily contaminated grey forest soils in the area. As a result, the soil pH was highly acidic and the concentration of copper, lead, arsenic, and uranium in the topsoil was higher than the relevant Maximum Admissible Concentration (MAC) for soils. The leaching test revealed that approximately half of each pollutant was presented as a reducible fraction as well as the ferric iron in horizon A was presented mainly as minerals with amorphous structure. So, the approach for remediation of the AMD-affected soils was based on the process of redoxolysis carried out by iron-reducing bacteria. Ferric iron hydroxides reduction and the heavy metals released into soil solutions was studied in the dependence on the source of organic (fresh or silage hay) which was used for growth and activity of soil microflora, initial soil pH (3.65; 4.2; and 5.1), and the ion content of irrigation solutions. The combination of limestone (2.0 g/ kg soil), silage addition (at rate of 45 g dry weight/ kg soil) in the beginning and reiterated at 6 month since the start of soil remediation, and periodical soil irrigation with slightly acidic solutions containing CaCl2 was sufficient the content of lead and arsenic in horizon A to be decreased to concentrations similar to the relevant MAC. The reducible, exchangeable, and carbonate mobile fractions were phases from which the pollutants was leached during the applied soil remediation. It determined the higher reduction of the pollutants bioavailability also as well as the process of ferric iron reduction was combined with neutralization of the soil acidity to pH (H2O) 6.2.

  18. Impact of Acid Mine Drainage on the hydrogeological system at Sia, Cyprus

    NASA Astrophysics Data System (ADS)

    Ng, Stephen; Malpas, John

    2013-04-01

    Discontinued mining of the volcanogenic massive sulphide ore bodies of Cyprus has left significant environmental concerns including Acid Mine Drainage. Remnant sulphide ore and tailings in waste dumps react with oxygenated rainwater to produce sulphuric acid, a process which is multiplied when metal-loving acidophilic bacteria are present. Given that Cyprus has a Mediterranean climate, characterized by its warm and dry summers and cool and wet winters, the low pH effluent with high levels of trace elements, particularly metals, is leached out of the waste tips particularly during the wet season. The Sia site includes an open mine-pit lake, waste rock and tailings dumps, a river leading to a downstream dam-lake, and a localised groundwater system. The study intends to: identify the point source and nature of contamination; analyze the mechanism and results of local acid generation; and understand how the hydrogeological system responds to seasonal variations. During two sampling campaigns, in the wet and dry seasons of 2011, water samples were collected from the mine pit lake, from upstream of the adjacent river down to the dam catchment, and from various boreholes close to the sulphide mine. The concentration of ions in waters varies between wet and dry seasons but, in both, relative amounts are directly related to pH. In the mine-pit lake, Fe, Mn, Mg, Cu, Pb, Zn, Ni, Co and Cd are found in higher concentrations in the dry season, as a result of substantial evaporation of water. The Sia River runs continuously in the wet season, and waters collected close to the waste tips have pH as low as 2.5 and higher concentrations of Al, Cu, Fe and Zn. Further downstream there is a significant decrease in trace metal contents with a concomitant rise of pH. Al and Fe dominate total cation content when pH is lower than 4. Al is derived from the weathering of clay minerals, especially during the wet season. Fe is derived from the oxidation of pyrite. Once pH's exceed 4, a white

  19. Diversity and Distribution of Arsenic-Related Genes Along a Pollution Gradient in a River Affected by Acid Mine Drainage.

    PubMed

    Desoeuvre, Angélique; Casiot, Corinne; Héry, Marina

    2016-04-01

    Some microorganisms have the capacity to interact with arsenic through resistance or metabolic processes. Their activities contribute to the fate of arsenic in contaminated ecosystems. To investigate the genetic potential involved in these interactions in a zone of confluence between a pristine river and an arsenic-rich acid mine drainage, we explored the diversity of marker genes for arsenic resistance (arsB, acr3.1, acr3.2), methylation (arsM), and respiration (arrA) in waters characterized by contrasted concentrations of metallic elements (including arsenic) and pH. While arsB-carrying bacteria were representative of pristine waters, Acr3 proteins may confer to generalist bacteria the capacity to cope with an increase of contamination. arsM showed an unexpected wide distribution, suggesting biomethylation may impact arsenic fate in contaminated aquatic ecosystems. arrA gene survey suggested that only specialist microorganisms (adapted to moderately or extremely contaminated environments) have the capacity to respire arsenate. Their distribution, modulated by water chemistry, attested the specialist nature of the arsenate respirers. This is the first report of the impact of an acid mine drainage on the diversity and distribution of arsenic (As)-related genes in river waters. The fate of arsenic in this ecosystem is probably under the influence of the abundance and activity of specific microbial populations involved in different As biotransformations. PMID:26603631

  20. The Importance of Sediment Sulfate Reduction to the Sulfate Budget of an Impoundment Receiving Acid Mine Drainage

    NASA Astrophysics Data System (ADS)

    Herlihy, Alan T.; Mills, Aaron L.; Hornberger, George M.; Bruckner, Amy E.

    1987-02-01

    Alkalinity generation by bacterial sulfate reduction (SR) has been shown to be an important neutralizing agent for acid mine drainage and acid precipitation in lakes and reservoirs. In order to quantify the importance of SR in an acidified system, a sulfate influx-efflux budget was constructed for Lake Anna, an impoundment in central Virginia that receives acid mine drainage. For the 1983 and 1984 water years, 48% (namely, 8.0 × 105 kg) of the sulfate entering the impoundment was removed from the water column within the first 2 km of the arm of the lake receiving the pollution. SR rates measured using 35S-labeled sulfate were extrapolated across the surface area of this arm of the lake; this calculated amount of sulfate removed was equal to 200% of the sulfate removed from the lake as calculated in the budget. The calculated alkalinity generated by this sulfate removal was more than twice that necessary to account for the observed pH increase in the impoundment. The magnitude of the sulfate removal and alkalinity generation demonstrates the quantitative importance of SR as an ecosystem level buffering mechanism.

  1. Sustainable rehabilitation of mining waste and acid mine drainage using geochemistry, mine type, mineralogy, texture, ore extraction and climate knowledge.

    PubMed

    Anawar, Hossain Md

    2015-08-01

    The oxidative dissolution of sulfidic minerals releases the extremely acidic leachate, sulfate and potentially toxic elements e.g., As, Ag, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Th, U, Zn, etc. from different mine tailings and waste dumps. For the sustainable rehabilitation and disposal of mining waste, the sources and mechanisms of contaminant generation, fate and transport of contaminants should be clearly understood. Therefore, this study has provided a critical review on (1) recent insights in mechanisms of oxidation of sulfidic minerals, (2) environmental contamination by mining waste, and (3) remediation and rehabilitation techniques, and (4) then developed the GEMTEC conceptual model/guide [(bio)-geochemistry-mine type-mineralogy- geological texture-ore extraction process-climatic knowledge)] to provide the new scientific approach and knowledge for remediation of mining wastes and acid mine drainage. This study has suggested the pre-mining geological, geochemical, mineralogical and microtextural characterization of different mineral deposits, and post-mining studies of ore extraction processes, physical, geochemical, mineralogical and microbial reactions, natural attenuation and effect of climate change for sustainable rehabilitation of mining waste. All components of this model should be considered for effective and integrated management of mining waste and acid mine drainage. PMID:25979297

  2. Proteome changes in the initial bacterial colonist during ecological succession in an acid mine drainage biofilm community

    SciTech Connect

    Mueller, Ryan; Dill, Brian; Pan, Chongle; Belnap, Christopher P.; Thomas, Brian; Verberkmoes, Nathan C; Hettich, Robert {Bob} L; Banfield, Jillian F.

    2011-01-01

    Proteomes of acid mine drainage biofilms at different stages of ecological succession were examined to understand microbial responses to changing community membership. We evaluated the degree of reproducibility of the community proteomes between samples of the same growth stage and found stable and predictable protein abundance patterns across time and sampling space, allowing for a set of 50 classifier proteins to be identified for use in predicting growth stages of undefined communities. Additionally, physiological changes in the dominant species, Leptospirillum Group II, were analysed as biofilms mature. During early growth stages, this population responds to abiotic stresses related to growth on the acid mine drainage solution. Enzymes involved in protein synthesis, cell division and utilization of 1- and 2-carbon compounds were more abundant in early growth stages, suggesting rapid growth and a reorganization of metabolism during biofilm initiation. As biofilms thicken and diversify, external stresses arise from competition for dwindling resources, which may inhibit cell division of Leptospirillum Group II through the SOS response. This population also represses translation and synthesizes more complex carbohydrates and amino acids in mature biofilms. These findings provide unprecedented insight into the physiological changes that may result from competitive interactions within communities in natural environments.

  3. The Role of Alkalinity Inputs in the Composition of Sediments in AN Acid Mine Drainage Remediated Stream: Hewett Fork, Ohio

    NASA Astrophysics Data System (ADS)

    Lopez, D. L.; Korenowsky, R. K.; Kruse, N.; Bowman, J.

    2012-12-01

    Hewett Fork, a tributary of Raccoon Creek in SE Ohio, is severely impacted by acid mine drainage. This stream is being actively treated using a calcium oxide doser. In this work, we report the results of our investigations into the chemical effect of remediation in the stream throughout an evaluation of the chemical composition of its sediments. Results show that the grain size of the sediments is finer in the areas where high alkalinity loads enter the stream, at the output from the doser and downstream of the confluence with alkaline tributaries. The composition of heavy metals (magnesium, aluminum, calcium, nickel, zinc, manganese, potassium, lead, chromium, copper, cobalt and arsenic) is higher in concentration in the fine-grained sediments where alkalinity enters the stream, forming two peaks of high sediment concentration along the stream, one at the doser and the second after the confluence with alkaline tributaries. Iron has a different behavior with a higher sediment concentration downstream from the doser at the areas where the grain size is larger, due to the kinetics of the oxidation process for the formation of iron (III) minerals. These results suggest that in remediation of acid-mine-drainage impacted streams, alkalinity inputs along and oxidation processes are important for the storage of heavy metals in the sediments.

  4. Remediation of acid mine drainage from the Santa Fe tin mine, Bolivia

    NASA Astrophysics Data System (ADS)

    Calvo, Daniel; Zamora Echenique, Gerardo; Alfonso, Pura; Casado, Jordi; Trujillo, Elvys; Jiménez-Franco, Abigail; Garcia-Valles, Maite

    2015-04-01

    The Santa Fe mine, department of Oruro, is located in the Andean Tin belt, is exploited for tin, zinc, lead and silver. This in an underground mine mined up to the -108 level. Today it is only mined up to the -50 level. Under this level the table water covers the mine. Water reaches the surface with a very acidic composition, with a high content in potentially toxic elements. This water drains directly to the Santa Fe River and contribute to the pollution present in this river that directly affect to the aquatic communities. In addition, population of this area have problems in the supply of drinking water, so remediation by obtaining cleaning water is a priority for this area. This study presents a neutralization-precipitation treatment with lime to the acid water inside the mine. The ore mineralogy of the Santa Fe mined deposit consists mainly in cassiterite, pyrite, sphalerite, galena, arsenopyrite argentite and sulphosalts. The host mineral is mainly quartz, with a minor content in feldspars and tourmaline. Alteration minerals as alunite, goethite and pumbojarosite are abundant and indicate the occurrence of reactions that lead to the formation of acid mine drainage. The mean pH of water drained from the Santa Fe mine is 2.2 and chemical analyses show high contents in potentially toxic elements: 27-295 ppm Zn, 0.05-0.2 ppm Pb, 0.06-0.09 ppm Cd, 04-0.12 ppm Cu, 113-165 ppm Fe, 4 ppm Mn and 564-664 ppm S. As and Sb were under 0.5 ppm. A settler tank inside the mine was designed by means of seal a selected gallery to clean the mine water. The function of this gallery is to sediment the sludge resulting from the neutralization - precipitation treatment process to obtain a clear water overflow continuously to the outside. The neutralization tests indicate that 0.65g/L of lime and 2ml of flocculant should be added to neutralize water up to pH 6-7. A flow rate of 80 L /s was considered. After a geotechnical study, a chamber located in the mine was selected to locate

  5. The fate of arsenic in sediments formed at a river confluence affected by acid mine drainage

    NASA Astrophysics Data System (ADS)

    Guerra, P. A.; Pasten, P. A.; Pizarro, G.; Simonson, K.; Escauriaza, C. R.; Gonzalez, C.; Bonilla, C.

    2012-12-01

    Fluvial confluences receiving acid mine drainage may play a critical role in a watershed as a suite of interactions between chemistry and hydrodynamics occur, determining the fate of toxic contaminants like arsenic. Solid reactive phases of iron and/or aluminum oxi-hydroxides may form or transform, ranging from iron oxide nanoparticles that aggregate and form floccules that are transported in the suspended load up to gravel and arsenic-rich rock coatings. In order to further understand the role of reactive fluvial confluences, we have studied the mixing between the Caracarani River (flow=170-640 L/s, pH 8, conductivity 1.5 mS/cm, total As<0.1 mg/L and total Fe< 5 mg/L) and the Azufre River (flow=45-245 L/s, pH<2, conductivity > 10 mS/cm, total As>2 mg/L, total Fe=35-125 mg/L), located in the Lluta watershed in northern Chile. This site is an excellent natural laboratory located in a water-scarce area, where the future construction of a dam has prompted the attention of decision makers and scientists interested in weighing the risks derived by the accumulation of arsenic-rich sediments. Suspended sediments (> 0.45 μm), riverbed sediments, and coated rocks were collected upstream and downstream from the confluence. Suspended sediments >0.45 μm and riverbed sediments were analyzed by total reflection x-ray fluorescence for metals, while coated river bed rocks were analyzed by chemical extractions and a semi-quantitative approach through portable x-ray fluorescence. Water from the Caracarani and Azufre rivers were mixed in the laboratory at different ratios and mixing velocities aiming to characterize the effect of the chemical-hydrodynamic environment where arsenic solids were formed at different locations in the confluence. Despite a wide range of iron and arsenic concentrations in the suspended sediments from the field (As=1037 ± 1372 mg/kg, Fe=21.0 ± 24.5 g/kg), we found a rather narrow As/Fe ratio, increasing from 36.5 to 55.2 mgAs/kgFe when the bulk water p

  6. Passive treatment of acid mine drainage in systems containing compost and limestone: Laboratory and field results

    SciTech Connect

    Watzlaf, G.R.; Pappas, D.M.

    1996-12-31

    Passive, down-flow systems, consisting of compost and limestone layers, termed successive alkalinity producing systems (SAPS), may be well suited for treatment of mine drainage containing ferric iron and/or aluminum. A column, simulating a SAPS, has been operated in the laboratory for 52 weeks. The 0.16-m diameter column consisted of a 0.30-m thick layer of limestone, a 0.76-m thick layer of spent mushroom compost thick layer of limestone, a 0.76-m thick layer of spent mushroom compost and 0.91 m of free standing water. Actual AMD (pH = 3.02, acidity = 218 mg/L (as CaCO{sub 3}), SO{sub 4} = 600 mg/L, Fe = 16.0 mg/L, Mn = 12.1 mg/L, and Al = 17.1 mg/L) was applied to the column at a rate of 3.8 mL/min. Effluent pH has remained above 6.2 (6.2-7.9) in the column system. A SAPS located in Jefferson County, PA has been monitored for the past 4.5 years. The SAPS has an approximate area of 1000 m{sup 2} and contains a 0.4-m thick layer of limestone, a 0.2-m thick layer of spent mushroom compost, and 1.5 m of free standing water. Mine water (acidity = 335 mg/L (as CaCO{sub 3}), SO{sub 4} = 1270 mg/L, Fe = 246 mg/L, Mn = 38.4 mg/L, and Al = <0.2 mg/L) flowed into the SAPS at a rate of 140 L/min. Water samples from the field and laboratory systems have been collected at strategic locations on a regular basis and analyzed for pH, alkalinity, acidity, Fe{sup 2+}, total Fe, Mn, Al, SO{sub 4}, Ca, Mg, Na, Co, Ni, and Zn. Alkalinity has been generated in both field and laboratory systems by a combination of limestone dissolution and sulfate reduction. The column generated an average of 378 mg/L of alkalinity; 74% due to limestone dissolution and 26% due to bacterial reduction of sulfate. The field SAPS generated an average of 231 mg/L of alkalinity and exhibited seasonal trends.

  7. Use of O and S Isotopes to Define Sources of Water and Sulfate in Acid Mine Drainage Waters

    NASA Astrophysics Data System (ADS)

    Earnest, D.

    2001-12-01

    Coal mining in Maryland, West Virginia, Pennsylvania, and other states has resulted in acid mine drainage problems in rivers throughout the region. The underground workings at the Kempton Mine have been abandoned since the 1950's, and the water filling these mines is discharged at a rate of 6,000,000 gallons per day into the headwaters of the Potomac River. This water has an average pH of 3.0 and an average dissolved load of 1 g/L. Evaluation of the mitigation options requires identification of water and acidity sources. We are using isotopic compositions of mine drainage waters to define hydrologic sources, flow paths, and acid sources. Water samples were taken monthly of mine water and other local sources. Oxygen isotope analyses are conducted on these samples. Seasonal variations in δ ^{18}O composition of mine drainage would suggest significant rapid meteoric input. Little or no variation in \\delta18O composition would suggest that mine drainage is derived primarily from groundwater sources or that the residence time in the mine is long. Sulfate precipitated as barite from these samples is analyzed for δ ^{34}S and \\delta18O. There is significantly more sulfate in the mine drainage waters than there is iron. The isotopic signature is used to determine whether the sulfur source is pyritic or organic. Sulfate δ 18O data are used to distinguish between sub-aerial and sub-aqueous oxidation of sulfur.

  8. Benthic metal fluxes and sediment diagenesis in a water reservoir affected by acid mine drainage: A laboratory experiment and reactive transport modeling

    NASA Astrophysics Data System (ADS)

    Torres, E.; Ayora, C.; Jiménez-Arias, J. L.; García-Robledo, E.; Papaspyrou, S.; Corzo, A.

    2014-08-01

    Reservoirs are one of the primary water supply sources. Knowledge of the metal fluxes at the water-sediment interfaces of reservoirs is essential for predicting their ecological quality. Redox oscillations in the water column are promoted by stratification; turnover events may significantly alter metal cycling, especially in reservoirs impacted by acid mine drainage (AMD). To study this phenomenon, an experiment was performed under controlled laboratory conditions. Sediment cores from an AMD-affected reservoir were maintained in a tank with reservoir water for approximately two months and subjected to alternating oxic-hypoxic conditions. A detailed metal speciation in solid phases of the sediment was initially performed by sequential extraction, and pore water was analyzed at the end of each redox period. Tank water metals concentrations were systematically monitored throughout the experiment. The experimental results were then used to calibrate a diffusion-reaction model and quantify the reaction rates and sediment-water fluxes. Under oxic conditions, pH, Fe and As concentrations decreased in the tank due to schwertmannite precipitation, whereas the concentrations of Al, Zn, Cu, Ni, and Co increased due to Al(OH)3 and sulfide dissolution. The reverse trends occurred under hypoxic conditions. Under oxic conditions, the fluxes calculated by applying Fick’s first law to experimental concentration gradients contradicted the fluxes expected based on the evolution of the tank water. According to the reactive transport calculations, this discrepancy can be attributed to the coarse resolution of sediment sampling. The one-cm-thick slices failed to capture effectively the notably narrow (1-2 mm) concentration peaks of several elements in the shallow pore water resulting from sulfide and Al(OH)3 dissolution. The diffusion-reaction model, extended to the complete year, computed that between 25% and 50% of the trace metals and less than 10% of the Al that precipitated under

  9. Application of maghemite nanoparticles as sorbents for the removal of Cu(II), Mn(II) and U(VI) ions from aqueous solution in acid mine drainage conditions

    NASA Astrophysics Data System (ADS)

    Etale, Anita; Tutu, Hlanganani; Drake, Deanne C.

    2014-06-01

    The adsorptive removal of Cu(II), Mn(II) and U(VI) by maghemite nanoparticles (NPs) was investigated under acid mine drainage (AMD) conditions to assess NP potential for remediating AMD-contaminated water. The effects of time, NP and metal concentration, as well as manganese and sulphate ions were quantified at pH 3. Adsorption of all three ions was rapid, and equilibrium was attained in 5 min or less. 56 % of Cu, 53 % of Mn and 49 % of U were adsorbed. In addition, adsorption efficiencies were enhanced by ≥10 % in the presence of manganese and sulphate ions, although Cu sorption was reduced in 1:2 Cu-to-Mn solutions. Adsorption also increased with pH: 86 % Cu, 62 % Mn and 77 % U were removed from solution at pH 9 and increasing initial metal concentrations. Increasing NP concentrations did not, however, always increase metal removal. Kinetics data were best described by a pseudo-second-order model, implying chemisorption, while isotherm data were better fitted by the Freundlich model. Metal removal by NPs was then tested in AMD-contaminated surface and ground water. Removal efficiencies of up to 46 % for Cu and 54 % for Mn in surface water and 8 % for Cu and 50 % for Mn in ground water were achieved, confirming that maghemite NPs can be applied for the removal of these ions from AMD-contaminated waters. Notably, whereas sulphates may increase adsorption efficiencies, high Mn concentrations in AMD will likely inhibit Cu sorption.

  10. Application of maghemite nanoparticles as sorbents for the removal of Cu(II), Mn(II) and U(VI) ions from aqueous solution in acid mine drainage conditions

    NASA Astrophysics Data System (ADS)

    Etale, Anita; Tutu, Hlanganani; Drake, Deanne C.

    2016-06-01

    The adsorptive removal of Cu(II), Mn(II) and U(VI) by maghemite nanoparticles (NPs) was investigated under acid mine drainage (AMD) conditions to assess NP potential for remediating AMD-contaminated water. The effects of time, NP and metal concentration, as well as manganese and sulphate ions were quantified at pH 3. Adsorption of all three ions was rapid, and equilibrium was attained in 5 min or less. 56 % of Cu, 53 % of Mn and 49 % of U were adsorbed. In addition, adsorption efficiencies were enhanced by ≥10 % in the presence of manganese and sulphate ions, although Cu sorption was reduced in 1:2 Cu-to-Mn solutions. Adsorption also increased with pH: 86 % Cu, 62 % Mn and 77 % U were removed from solution at pH 9 and increasing initial metal concentrations. Increasing NP concentrations did not, however, always increase metal removal. Kinetics data were best described by a pseudo-second-order model, implying chemisorption, while isotherm data were better fitted by the Freundlich model. Metal removal by NPs was then tested in AMD-contaminated surface and ground water. Removal efficiencies of up to 46 % for Cu and 54 % for Mn in surface water and 8 % for Cu and 50 % for Mn in ground water were achieved, confirming that maghemite NPs can be applied for the removal of these ions from AMD-contaminated waters. Notably, whereas sulphates may increase adsorption efficiencies, high Mn concentrations in AMD will likely inhibit Cu sorption.

  11. S. 3168: A Bill to amend the Surface Mining Control and Reclamation Act of 1977 to improve control of acid mine drainage, and for other purposes. Introduced in the Senate of the United States, August 11, 1992

    SciTech Connect

    Not Available

    1992-01-01

    This Act may be cited as the [open quotes]Acid Mine Drainage Abatement Act of 192[close quotes]. The purpose of this bill is to amend the Surface Mining Control and Reclamation Act of 1977 to improve control of acid mine drainage, and for other purposes. The proposed amendments are listed.

  12. Interaction of acid mine drainage with waters and sediments of West Squaw Creek in the West Shasta Mining District, California

    USGS Publications Warehouse

    Filipek, L.H.; Kirk, Nordstrom D.; Ficklin, W.H.

    1987-01-01

    Acid mine drainage has acidified large volumes of water and added high concentrations of dissolved heavy metals to West Squaw Creek, a California stream draining igneous rocks of low acid-neutralizing capacity. During mixing of the acid sulfate stream waters in the South Fork of West Squaw Creek with an almost equal volume of dilute uncontaminated water, Cu, Zn, Mn, and Al remained in solution rather than precipitating or adsorbing on solid phases. Changes in the concentration of these generally conservative metals could be used to determine relative flow volumes of acid tributaries and the main stream. An amorphous orange precipitate (probably ferric hydroxides or a mixture of ferric hydroxides and jarosite) was ubiquitous in the acid stream beds and was intimately associated with algae at the most acid sites. Relative sorption of cations decreased with decreasing water pH. However, arsenic was almost completely scavenged from solution within a short distance from the sulfide sources.

  13. The use of ERTS-1 MSS data for mapping strip mines and acid mine drainage in Pennsyvania

    NASA Technical Reports Server (NTRS)

    Alexander, S. S.; Dein, J. L.; Gold, D. P.

    1973-01-01

    Digital processing of ERTS-I MSS data for areas around the west branch of the Susquehanna River permits identification of stripped areas including ones that are not discernible from visual analysis of ERTS imagery. Underflight data and ground-based observations are used for ground-truth and as a basis for designing more refined operators to make sub-classifications of stripped areas, particularly with regard to manifestations of acid mine drainage; because of associated diagnostic effects on vegetation, seasonal changes in classifiction criteria are being documented as repeated, cloud-free ERTS-I coverage of the same area becomes available. Preliminary results indicate that ERTS data can be used to moniter not only the total extent of stripping in given areas but also the effectiveness of reclamation and pollution abatement procedures.

  14. Thermodynamic data for modeling acid mine drainage problems: compilation and estimation of data for selected soluble iron-sulfate minerals

    USGS Publications Warehouse

    Hemingway, Bruch S.; Seal, Robert R., II; Chou, I-Ming

    2002-01-01

    Enthalpy of formation, Gibbs energy of formation, and entropy values have been compiled from the literature for the hydrated ferrous sulfate minerals melanterite, rozenite, and szomolnokite, and a variety of other hydrated sulfate compounds. On the basis of this compilation, it appears that there is no evidence for an excess enthalpy of mixing for sulfate-H2O systems, except for the first H2O molecule of crystallization. The enthalpy and Gibbs energy of formation of each H2O molecule of crystallization, except the first, in the iron(II) sulfate - H2O system is -295.15 and -238.0 kJ?mol-1, respectively. The absence of an excess enthalpy of mixing is used as the basis for estimating thermodynamic values for a variety of ferrous, ferric, and mixed-valence sulfate salts of relevance to acid-mine drainage systems.

  15. Passive treatment of acid mine drainage using coal combustion by-products and spent mushroom substrate: Results of column study

    SciTech Connect

    Crisp, T.E.; Nairn, R.W.; Strevett, K.A.; Everett, J.

    1998-12-31

    A column study was conducted to evaluate the feasibility of using of coal combustion by-products (CCB) as alkaline materials in a field scale downflow constructed wetlands for acid mine drainage treatment. Five columns (15.24 cm in diameter and 91.44 cm high) were constructed and filled with a combination of spent mushroom substrate (SMS) and one of three alkaline materials (limestone, hydrated fly ash, or fluidized bed ash). The five mixtures utilized were 10% fluidized bed ash/40% limestone (FBA/LS), 10% fluidized bed ash (FBA), 50% limestone (LS), 50% hydrated fly ash (HFA),m and 50% sieved (>1.5 cm) hydrated fly ash (S. HFA) with the remainder as SMS on a w/w basis. Column received synthetic acid mine drainage containing: 400 mg/L iron, 59 mg/L aluminum, 11 mg/L manganese, 50% mg/L magnesium, 40 mg/L calcium, and 1200 mg/L sulfate for 5 months. Anoxic conditions in the influent reservoirs were maintained by a positive nitrogen pressure head. Flow rates of 2.0 mL/minute to each column were maintained by a multichannel peristaltic pump. For all columns, effluent acidity concentrations were less than influent acidity concentration (877{sup {minus}}30, n = 75f). Mean effluent acidity concentrations were 241 mg/L (FBA/LS), 186 mg/L (FBA), 419 mg/L (LS), {minus}28.5 mg/L (HFA), and 351 mg/L (S. HFA), respectively. While all column produced measurable alkalinity, only the HFA column produced a net alkaline discharge. The results of these column studies are applicable to the design and sizing of innovative field scale systems using alkaline-rich CCB`s.

  16. Variability of Near-stream, Sub-surface Major-ion and Tracer Concentrations in an Acid Mine Drainage Environment

    NASA Astrophysics Data System (ADS)

    Bencala, K. E.; Kimball, B. A.; Runkel, R. L.

    2006-12-01

    In acid mine drainage environments, tracer-injection and synoptic sampling approaches provide tools for making operational estimates of solute loading within a stream segment. Identifying sub-surface contaminant sources remains a challenge both for characterization of in-stream metal loading and hydrological process research. There is a need to quantitatively define the character and source of contaminants entering streams from ground-water pathways, as well as the potential for changes in water chemistry and contaminant concentrations along these flow paths crossing the sediment-water interface. Complicating the identification of inflows is the mixing of solute sources which may occur in the `near-stream' subsurface areas and specifically along hyporheic exchange flows (HEFs). In Mineral Creek (Silverton, Colorado), major-ion (SO42-, Cl-, Na+, Ca2+, Mg2+) meter-scale sampling shows that subsurface inflows and likely HEFs occur in a hydro- geochemical setting of significant, one order-of-magnitude, spatial variation in the solute concentrations. Transient Storage Models (TSMs) are a tool for interpreting the in-stream responses of solute transport in streams influenced by hyporheic exchange flows. Simulations using the USGS TSM code OTIS are interpreted as suggesting that in Mineral Creek the strong concentration `tailing' of bromide following the tracer injection occurred, at least in part, from HEFs in a hydro - solute transport setting of likely multiple, dispersed and mixed sources of water along a 64 m sub-reach of the nominally gaining stream. In acid mine drainage environments, the ability to distinguish between local and deep solute sources is critical in modeling reactive transport along the stream, as well as in identifying the geochemical evolution of dispersed, subsurface inflows thorough the catchment.

  17. Using a mass balance to understand the geology and geochemistry of a reservoir receiving and discharging acid mine drainage

    SciTech Connect

    Turney, D.C.; Edwards, K.

    1996-11-01

    Howard-Williams Lake is a 14.5 acre reservoir located in an abandoned coal mine in Perry County, Ohio. With a pH of 3.0 and acidity values of 300--400 mg/L, the reservoir has no plants or fish currently surviving in the lake. Reclamation of spoil piles adjacent to the lake to the north in the late 1980s was not successful in reducing the acidity of the lake. Currently, papermill sludge is being used on the reclaimed area to the north to promote vegetation, but the reservoir has shown no signs of improving. The goal of this project is to transform the lake into a fishable and swimmable one. The reservoir is receiving about 175 gallons per minute of acid mine drainage, not including seepage into the lake, from eight different sources. Three of the sources account for about 165 gallons per minute of the surface water that enters the lake. These inflows have relatively low acidity readings, which range from 66 mg/L to 568 mg/L. The other five sources of acid mine drainage have much lower flowrates, but have acidity values as high as 3,000 mg/L. Samples of all of the surface inflows and the outflow of the lake were taken and sent to a laboratory and tested for the following parameters: total acidity as CaCO{sub 3}, total alkalinity as CaCO{sub 2}, specific conductivity, total suspended solids, sulfate, chloride calcium, magnesium, sodium, potassium, total iron, total manganese, aluminum, and hardness. During sampling of the surface inflows, volumetric flowrates were measured for each inflow. Once the flowrates and the concentrations of the various parameters were known, a mass balance could be constructed which would show how much of each parameter was entering the lake each day. These data were then used to gain an understanding of the geochemistry and geology of the site.

  18. Leaf Associated Microbial Activities in a Stream Affected by Acid Mine Drainage

    NASA Astrophysics Data System (ADS)

    Schlief, Jeanette

    2004-11-01

    Microbial activity was assessed on birch leaves and plastic strips during 140 days of exposure at three sites in an acidic stream of the Lusatian post-mining landscape, Germany. The sites differed in their degrees of ochre deposition and acidification. The aim of the study was (1) to follow the microbial activities during leaf colonization, (2) to compare the effect of different environmental conditions on leaf associated microbial activities, and (3) to test the microbial availability of leaf litter in acidic mining waters. The activity peaked after 49 days and subsequently decreased gradually at all sites. A formation of iron plaques on leaf surfaces influenced associated microbial activity. It seemed that these plaques inhibit the microbial availability of leaf litter and serve as a microbial habitat by itself. (

  19. Community genomic and proteomic analysis of chemoautotrophic, iron-oxidizing "Leptospirillum rubarum" (Group II) and Leptospirillum ferrodiazotrophum (Group III) in acid mine drainage biofilms

    SciTech Connect

    Goltsman, Daniela; Denef, Vincent; Singer, Steven; Verberkmoes, Nathan C; Lefsrud, Mark G; Mueller, Ryan; Dick, Gregory J.; Sun, Christine; Wheeler, Korin; Zelma, Adam; Baker, Brett J.; Hauser, Loren John; Land, Miriam L; Shah, Manesh B; Thelen, Michael P.; Hettich, Robert {Bob} L; Banfield, Jillian F.

    2009-01-01

    We analyzed near-complete population (composite) genomic sequences for coexisting acidophilic iron-oxidizing Leptospirillum Groups II and III bacteria (phylum Nitrospirae) and an extrachromosomal plasmid from a Richmond Mine, CA acid mine drainage (AMD) biofilm. Community proteomic analysis of the genomically characterized sample and two other biofilms identified 64.6% and 44.9% of the predicted proteins of Leptospirillum Groups II and III, respectively and 20% of the predicted plasmid proteins. The bacteria share 92% 16S rRNA gene sequence identity and > 60% of their genes, including integrated plasmid-like regions. The extrachromosomal plasmid encodes conjugation genes with detectable sequence similarity to genes in the integrated conjugative plasmid, but only those on the extrachromosomal element were identified by proteomics. Both bacteria have genes for community-essential functions, including carbon fixation, biosynthesis of vitamins, fatty acids and biopolymers (including cellulose); proteomic analyses reveal these activities. Both Leptospirillum types have multiple pathways for osmotic protection. Although both are motile, signal transduction and methyl-accepting chemotaxis proteins are more abundant in Leptospirillum Group III, consistent with its distribution in gradients within biofilms. Interestingly, Leptospirillum Group II uses a methyl-dependent and Leptospirillum Group III a methyl-independent response pathway. Although only Leptospirillum Group III can fix nitrogen, these proteins were not identified by proteomics. Abundances of core proteins are similar in all communities, but abundance levels of unique and shared proteins of unknown function vary. Some proteins unique to one organism were highly expressed and may be key to the functional and ecological differentiation of Leptospirillum Groups II and III.

  20. SODA ASH TREATMENT OF NEUTRALIZED MINE DRAINAGE

    EPA Science Inventory

    Utilization of acid mine drainage (AMD) streams as a source of potable and industrial water has become a major goal of several proposed AMD treatment schemes. From among the various schemes available, the lime neutralization/soda ash softening process was selected for use at Alto...

  1. Remediation of acid mine drainage within strip mine spoil by sulfate reduction using waste organic matter

    SciTech Connect

    Stalker, J.; Rose, A.W.; Michaud, L.H.

    1996-12-31

    Many treatment options for AMD, like wetlands and anoxic limestone drains, are limited by acidity, metal loadings, flow rate or areal requirements so as to be inapplicable at many sites. In-situ bacterial sulfate reduction is proposed as a solution for certain settings. Requirements for successful in-situ bacterial sulfate reduction include dissolved sulfate, an organic substrate, permanent anaerobic conditions, a mixed culture of bacteria, appropriate nutrients, and a sufficient AMD contact time. These requirements can be provided within mine spoil by injection of waste organic matter into an extensive zone of saturated spoil. Laboratory experiments on cheese whey, lactate, non-degraded sawdust, partially degraded sawdust, pulped newspaper and mushroom compost have all yielded sulfate reduction, increased alkalinity and iron sulfide precipitate in AMD with pH < 4.0. The addition of a small amount of dolomite to the organic matter creates alkaline microenvironments that facilitate the initiation of sulfate reduction. The rates of sulfate reduction using cellulose materials are slow but the rate for milk products is much more rapid. A field test utilizing partially degraded sawdust is underway. A total of 11.3 tons of sawdust mixed with 5% dolomite, 5% sewage sludge and a mixed bacterial culture was successfully injected into 4 drill holes in mine spoil as 13% w/v suspension, The spoil had enough coarse porosity for injection into the saturated subsurface at about 300 L/min, Data on in-situ SO{sub 4} reduction rates and water quality are being collected in preparation for a full remediation program at the site, which has an extensive zone of saturated spoil 10-20 m thick.

  2. Occurrence, properties and pollution potential of environmental minerals in acid mine drainage.

    PubMed

    Valente, T Maria; Leal Gomes, C

    2009-01-15

    This paper describes the occurrences, the mineralogical assemblages and the environmental relevance of the AMD-precipitates from the abandoned mine of Valdarcas, Northern Portugal. At this mining site, these precipitates are particularly related with the chemical speciation of iron, which is in according to the abundance of mine wastes enriched in pyrrhotite and pyrite. The more relevant supergene mineralogical assemblages include the following environmental minerals: soluble metal-salts, mainly sulphates, revealing seasonal behaviour, iron-hydroxysulphates and iron-oxyhydroxides, both forming ochre precipitates of poorly and well-crystalline minerals. Pollution potential of the most highly water soluble salts was analysed in order to evaluate the environmental effect of their dissolution by rainfall. Laboratory experiments, carried out with iron and aluminium sulphates, demonstrated the facility to release metals, sulphate and acidity upon dissolution. Regarding the ochre precipitates, composed by several less soluble iron (III)-minerals, the spatial distribution on the nearby aqueous system as well as the proportion of Jarosite, Schwertmannite and Goethite in the mixtures gave information about the halo's contamination promoted by the AMD emerging from the waste-dumps. PMID:19004477

  3. DEMONSTRATION OF AN INTEGRATED, PASSIVE BIOLOGICAL TREATMENT PROCESS FOR AMD

    EPA Science Inventory

    An innovative, cost-effective, biological treatment process has been designed by MSE Technology Applications, Inc. to treat acid mine drainage (AMD). A pilot-scale demonstration is being conducted under the Mine Waste Technology Program using water flowing from an abandoned mine ...

  4. Eukaryotic stromatolite builders in acid mine drainage: Implications for Precambrian iron formations and oxygenation of the atmosphere?

    NASA Astrophysics Data System (ADS)

    Brake, S. S.; Hasiotis, S. T.; Dannelly, H. K.; Connors, K. A.

    2002-07-01

    Biological activity of Euglena mutabilis, an acidophilic, photosynthetic protozoan, contributes to the formation of Fe-rich stromatolites in acid mine drainage systems. E. mutabilis is the dominant microbe in bright green benthic mats (biofilm), coating drainage channels at abandoned coal mine sites in Indiana. It builds biolaminates through phototactic and aerotactic behavior, similar to prokaryotes, by moving through precipitates that periodically cover the mats. E. mutabilis also contributes to formation of Fe-rich stromatolites by (1) intracellularly storing Fe compounds released after death, contributing to the solid material of stromatolites and acting as nucleation sites for precipitation of authigenic Fe minerals, and (2) generating O2 via photosynthesis that further facilitates precipitation of reduced Fe, any excess O2 not consumed by Fe precipitation being released to the atmosphere. Recognition of E. mutabilis dominated biofilm in acidic systems raises a provocative hypothesis relating processes involved in formation of Fe-rich stromatolites by E. mutabilis to those responsible for development of Precambrian stromatolitic Fe formations and oxygenation of the early atmosphere.

  5. Site characterization and containment/remediation of acid mine drainage at an abandoned mine waste dump

    SciTech Connect

    Djahanguiri, F.; Snodgrass, J.; Koerth, J.

    1996-12-31

    This paper focuses on the preliminary results of laboratory tests to evaluate a new suspension grout consisting of a mixture of a naturally occurring lignite coal based wax {open_quotes}montan wax{close_quotes}, sodium bentonite {open_quotes}pure gold grout{close_quotes}, and water. The test program assesses the suitability of the grout for creating subsurface containment barriers in coal waste dump sites for acid mine seepage control to surface and ground waters. The laboratory activities evaluated the reduction in permeability that could be achieved in a coal waste dump site under optimum conditions and the compatibility of the grout with representative waste from the test site. Information on geological, geochemical and geophysical about the test site is presented. Laboratory formulation of the grout is complete and simulation of field condition is in progress. Pregrout geophysical surveys for determination of hydrogeologic conditions at the site are also completed. Based on geophysical surveys, a grout curtain is proposed which will consist of two rows of grout placement holes in an array across the seepage area toward Belt Creek in Montana, Post-grout geophysical survey will be carried out immediately after grouting work. Performance of the grout curtain will be monitored by collection of water samples from monitoring wells in the Belt Creek and seepage area.

  6. AMELIORATION OF ACID MINE DRAINAGE USING REACTIVE MIXTURES IN PERMEABLE REACTIVE BARRIERS

    EPA Science Inventory

    The generation and release of acidic drainage from mine wastes is an environmental problem of international scale. The use of zero-valent iron and/or iron mixtures in subsurface Permeable Reactive Barriers (PRB) presents a possible passive alternative for remediating acidic grou...

  7. Effect Of Imposed Anaerobic Conditions On Metals Release From Acid-Mine Drainage Contaminated Streambed Sediments

    EPA Science Inventory

    Remediation of streams influenced by mine-drainage may require removal and burial of metal-containing bed sediments. Burial of aerobic sediments into an anaerobic environment may release metals, such as through reductive dissolution of metal oxyhydroxides. Mining-impacted aerob...

  8. CONSTRUCTION OF MODULAR FIELD-BIOREACTOR FOR ACID MINE DRAINAGE TREATMENT

    EPA Science Inventory

    The paper focuses on the improvements to engineered features of a passive technology that has been used for remediation of acid rock drainage (ARD). This passive remedial technology, a sulfate-reducing bacteria (SRB) bioreactor, takes advantage of the ability of SRB that, if sup...

  9. THE USE OF COAL COMBUSTION BY-PRODUCTS FOR IN SITU TREATMENT OF ACID MINE DRAINAGE

    SciTech Connect

    Geoffrey A. Canty; Jess W. Everett

    2004-09-30

    In 1994 a demonstration project was undertaken to investigate the effectiveness of using CCBs for the in situ treatment of acidic mine water. Actual injection of alkaline material was performed in 1997 with initial positive results; however, the amount of alkalinity added to the system was limited and resulted in short duration treatment. In 1999, a CBRC grant was awarded to further investigate the effectiveness of alkaline injection technology (AIT). Funds were released in fall 2001. In December 2001, 2500 tons of fluidized bed combustion (FBC) ash were injected into the wells used in the 1997 injection project. Post injection monitoring continued for 24 months. During this period the mine chemistry had gone through a series of chemical changes that manifested as stages or ''treatment phases.'' The mine system appeared to be in the midst of reestablishing equilibrium with the partial pressure of mine headspace. Alkalinity and pH appeared to be gradually increasing during this transition. As of December 2003, the pH and alkalinity were roughly 7.3 and 65 ppm, respectively. Metal concentrations were significantly lower than pre-injection levels, but iron and manganese concentrations appeared to be gradually increasing (roughly 30 ppm and 1.25 ppm, respectively). Aluminum, nickel, and zinc were less than pre-injection concentrations and did not appear to be increasing (roughly

  10. Quantitative microbial community analysis of three different sulfidic mine tailing dumps generating acid mine drainage.

    PubMed

    Kock, Dagmar; Schippers, Axel

    2008-08-01

    The microbial communities of three different sulfidic and acidic mine waste tailing dumps located in Botswana, Germany, and Sweden were quantitatively analyzed using quantitative real-time PCR (Q-PCR), fluorescence in situ hybridization (FISH), catalyzed reporter deposition-FISH (CARD-FISH), Sybr green II direct counting, and the most probable number (MPN) cultivation technique. Depth profiles of cell numbers showed that the compositions of the microbial communities are greatly different at the three sites and also strongly varied between zones of oxidized and unoxidized tailings. Maximum cell numbers of up to 10(9) cells g(-1) dry weight were determined in the pyrite or pyrrhotite oxidation zones, whereas cell numbers in unoxidized tailings were significantly lower. Bacteria dominated over Archaea and Eukarya at all tailing sites. The acidophilic Fe(II)- and/or sulfur-oxidizing Acidithiobacillus spp. dominated over the acidophilic Fe(II)-oxidizing Leptospirillum spp. among the Bacteria at two sites. The two genera were equally abundant at the third site. The acidophilic Fe(II)- and sulfur-oxidizing Sulfobacillus spp. were generally less abundant. The acidophilic Fe(III)-reducing Acidiphilium spp. could be found at only one site. The neutrophilic Fe(III)-reducing Geobacteraceae as well as the dsrA gene of sulfate reducers were quantifiable at all three sites. FISH analysis provided reliable data only for tailing zones with high microbial activity, whereas CARD-FISH, Q-PCR, Sybr green II staining, and MPN were suitable methods for a quantitative microbial community analysis of tailings in general. PMID:18586975

  11. Impact of AMD on water quality in critical watershed in the Hudson River drainage basin: Phillips Mine, Hudson Highlands, New York

    NASA Astrophysics Data System (ADS)

    Gilchrist, Sivajini; Gates, Alexander; Szabo, Zoltan; Lamothe, Paul J.

    2009-03-01

    A sulfur and trace element enriched U-Th-laced tailings pile at the abandoned Phillips Mine in Garrison, New York, releases acid mine drainage (AMD, generally pH < 3, minimum pH 1.78) into the first-order Copper Mine Brook (CMB) that drains into the Hudson River. The pyrrhotite-rich Phillips Mine is located in the Highlands region, a critical water source for the New York metro area. A conceptual model for derivation/dissolution, sequestration, transport and dilution of contaminants is proposed. The acidic water interacts with the tailings, leaching and dissolving the trace metals. AMD evaporation during dry periods concentrates solid phase trace metals and sulfate, forming melanterite (FeSO4·7H2O) on sulfide-rich tailings surfaces. Wet periods dissolve these concentrates/precipitates, releasing stored acidity and trace metals into the CMB. Sediments along CMB are enriched in iron hydroxides which act as sinks for metals, indicating progressive sequestration that correlates with dilution and sharp rise in pH when mine water mixes with tributaries. Seasonal variations in metal concentrations were partly attributable to dissolution of the efflorescent salts with their sorbed metals and additional metals from surging acidic seepage induced by precipitation.

  12. Impact of AMD on water quality in critical watershed in the Hudson River drainage basin: Phillips Mine, Hudson Highlands, New York

    USGS Publications Warehouse

    Gilchrist, S.; Gates, A.; Szabo, Z.; Lamothe, P.J.

    2009-01-01

    A sulfur and trace element enriched U-Th-laced tailings pile at the abandoned Phillips Mine in Garrison, New York, releases acid mine drainage (AMD, generally pH < 3, minimum pH 1.78) into the first-order Copper Mine Brook (CMB) that drains into the Hudson River. The pyrrhotite-rich Phillips Mine is located in the Highlands region, a critical water source for the New York metro area. A conceptual model for derivation/dissolution, sequestration, transport and dilution of contaminants is proposed. The acidic water interacts with the tailings, leaching and dissolving the trace metals. AMD evaporation during dry periods concentrates solid phase trace metals and sulfate, forming melanterite (FeSO4???7H2O) on sulfide-rich tailings surfaces. Wet periods dissolve these concentrates/precipitates, releasing stored acidity and trace metals into the CMB. Sediments along CMB are enriched in iron hydroxides which act as sinks for metals, indicating progressive sequestration that correlates with dilution and sharp rise in pH when mine water mixes with tributaries. Seasonal variations in metal concentrations were partly attributable to dissolution of the efflorescent salts with their sorbed metals and additional metals from surging acidic seepage induced by precipitation. ?? 2008 Springer-Verlag.

  13. Mineral-microorganism interactions in Acid Mine Drainage environments: preliminary results

    NASA Astrophysics Data System (ADS)

    Carbone, Cristina; Zotti, Mirca; Pozzolini, Marina; Giovine, Marco; Di Piazza, Simone; Mariotti, Mauro; Lucchetti, Gabriella

    2014-05-01

    Minerals play a key role in controlling the mobility and distribution of metals and metalloids of environmental concern in supergenic environments. These are involved in a variety of processes, spanning the alteration of primary minerals to the formation of secondary authigenic phases and can represent a source or a trap for Potentially Ecotoxic Elements (PTEs). Soil, sediments, and waters heavily polluted with PTEs through AMD processes are a reservoir of a unusual bacteria and fungi well adapted to these toxic environments. Classical studies of biotic weathering have mainly focused on water-mineral interaction and on the ability of microorganism to influence the soil solution chemical composition. In this work, we analyzed two different representative ochreous and greenish-blue AMD colloidal precipitates in order to i) characterize the biota population present in these colloidal minerals and ii) verify the bioaccumulation of PTEs into the fungi and the potential impact of bacteria in the geochemistry of the system. The samples are composed by nanocrystalline goethite which contains high amounts of Fe, Cu, Zn, Pb, and Ni and woodwardite that is characterized by Cu, Zn, Ni, Y, and Ce. These precipitates were examined in order to evaluate the presence of fungal strains and to extract bacteria DNA. The preliminary results of fungi characterization show an interesting and selected mycobiota able to survive under unfavourable environmental conditions. A significant number of fungal strains was isolated in pure culture. Most of them belong to the genus Mucor and Penicillium. It is worth noting the presence of Trametes versicolor, a macrofungal lignicolous species already known for heavy metal biosorption capability from aqueous solution (Gülay et al 2003). The same colloidal precipitates have been processed to extract bacteria DNA, using a specific procedure developed for DNA extraction from sediments. The results gave a good yield of nucleic acids and the positive PCR

  14. Strontium isotope quantification of siderite, brine and acid mine drainage contributions to abandoned gas well discharges in the Appalachian Plateau

    SciTech Connect

    Chapman, Elizabeth C.; Capo, Rosemary C.; Stewart, Brian W.; Hedin, Robert S.; Weaver, Theodore J.; Edenborn, Harry M.

    2013-04-01

    Unplugged abandoned oil and gas wells in the Appalachian region can serve as conduits for the movement of waters impacted by fossil fuel extraction. Strontium isotope and geochemical analysis indicate that artesian discharges of water with high total dissolved solids (TDS) from a series of gas wells in western Pennsylvania result from the infiltration of acidic, low Fe (Fe < 10 mg/L) coal mine drainage (AMD) into shallow, siderite (iron carbonate)-cemented sandstone aquifers. The acidity from the AMD promotes dissolution of the carbonate, and metal- and sulfate-contaminated waters rise to the surface through compromised abandoned gas well casings. Strontium isotope mixing models suggest that neither upward migration of oil and gas brines from Devonian reservoirs associated with the wells nor dissolution of abundant nodular siderite present in the mine spoil through which recharge water percolates contribute significantly to the artesian gas well discharges. Natural Sr isotope composition can be a sensitive tool in the characterization of complex groundwater interactions and can be used to distinguish between inputs from deep and shallow contamination sources, as well as between groundwater and mineralogically similar but stratigraphically distinct rock units. This is of particular relevance to regions such as the Appalachian Basin, where a legacy of coal, oil and gas exploration is coupled with ongoing and future natural gas drilling into deep reservoirs.

  15. Fe biogeochemistry in reclaimed acid mine drainage precipitates--implications for phytoremediation.

    PubMed

    Rojas, Claudia; Martínez, Carmen Enid; Bruns, Mary Ann

    2014-01-01

    At a 50-year-old coal mine drainage barrens in central Pennsylvania, USA, we evaluated the biogeochemistry of acidic, Fe(III)oxy(hydr)oxide precipitates in reclaimed plots and compared them to untreated precipitates in control areas. Reclaimed plots supported successional vegetation that became established after a one-time compost and lime treatment in 2006, while control plots supported biological crusts. Precipitates were sampled from moist yet unsaturated surface layers in an area with lateral subsurface flow of mine drainage above a fragipan. Fe(II) concentrations were three- to five-fold higher in reclaimed than control precipitates. Organically bound Fe and amorphous iron oxides, as fractions of total Fe, were also higher in reclaimed than control precipitates. Estimates of Fe-reducing and Fe-oxidizing bacteria were four- to tenfold higher in root-adherent than both types of control precipitates. By scaling up measurements from experimental plots, total Fe losses during the 5-yr following reclamation were estimated at 45 t Fe ha(-1) yr(-1). PMID:24063953

  16. Metagenomic analysis reveals adaptations to a cold-adapted lifestyle in a low-temperature acid mine drainage stream.

    PubMed

    Liljeqvist, Maria; Ossandon, Francisco J; González, Carolina; Rajan, Sukithar; Stell, Adam; Valdes, Jorge; Holmes, David S; Dopson, Mark

    2015-04-01

    An acid mine drainage (pH 2.5-2.7) stream biofilm situated 250 m below ground in the low-temperature (6-10°C) Kristineberg mine, northern Sweden, contained a microbial community equipped for growth at low temperature and acidic pH. Metagenomic sequencing of the biofilm and planktonic fractions identified the most abundant microorganism to be similar to the psychrotolerant acidophile, Acidithiobacillus ferrivorans. In addition, metagenome contigs were most similar to other Acidithiobacillus species, an Acidobacteria-like species, and a Gallionellaceae-like species. Analyses of the metagenomes indicated functional characteristics previously characterized as related to growth at low temperature including cold-shock proteins, several pathways for the production of compatible solutes and an anti-freeze protein. In addition, genes were predicted to encode functions related to pH homeostasis and metal resistance related to growth in the acidic metal-containing mine water. Metagenome analyses identified microorganisms capable of nitrogen fixation and exhibiting a primarily autotrophic lifestyle driven by the oxidation of the ferrous iron and inorganic sulfur compounds contained in the sulfidic mine waters. The study identified a low diversity of abundant microorganisms adapted to a low-temperature acidic environment as well as identifying some of the strategies the microorganisms employ to grow in this extreme environment. PMID:25764459

  17. pH dependence of iron photoreduction in a rocky mountain stream affected by acid mine drainage

    USGS Publications Warehouse

    McKnight, Diane M.; Kimball, B.A.; Runkel, R.L.

    2001-01-01

    The redox speciation of dissolved iron and the transport of iron in acidic, metal-enriched streams is controlled by precipitation and dissolution of iron hydroxides, by photoreduction of dissolved ferric iron and hydrous iron oxides, and by oxidation of the resulting dissolved ferrous iron. We examined the pH dependence of these processes in an acidic mine-drainage stream, St Kevin Gulch, Colorado, by experimentally increasing the pH of the stream from about 4.0 to 6.5 and following the downstream changes in iron species. We used a solute transport model with variable flow to evaluate biogeochemical processes controlling downstream transport. We found that at pH 6.4 there was a rapid and large initial loss of ferrous iron concurrent with the precipitation of aluminium hydroxide. Below this reach, ferrous iron was conservative during the morning but there was a net downstream loss of ferrous iron around noon and in the afternoon. Calculation of net oxidation rates shows that the noontime loss rate was generally much faster than rates for the ferrous iron oxidation at pH 6 predicted by Singer and Stumm (1970. Science 167: 1121). The maintenance of ferrous iron concentrations in the morning is explained by the photoreduction of photoreactive ferric species, which are then depleted by noon. Copyright ?? 2001 John Wiley & Sons, Ltd.

  18. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    1999-01-01

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion-FBC ash). Success will be measured in terms of technical feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into four major sections. The first deals with the Hydraulic Injection component. This section of the report reports on progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase III (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  19. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    1999-07-01

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion-FBC ash). Success will be measured in terms of technical feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into three major sections. The first deals with the Hydraulic Injection component. This section of the report describes the progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  20. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    1999-04-01

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion-FBC ash). Success will be measured in terms of technical feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into three major sections. The first deals with the Hydraulic Injection component. This section of the report describes the progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  1. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    2000-04-01

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion-FBC ash). Success will be measured in terms of technical feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into three major sections. The first deals with the Hydraulic Injection component. This section of the report describes the progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  2. DISPOSAL OF FLUIDIZED BED COMBUSTION ASH IN AN UNDERGROUND MINE TO CONTROL ACID MINE DRAINAGE AND SUBSIDENCE

    SciTech Connect

    Unknown

    2000-01-01

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion-FBC ash). Success will be measured in terms of technical feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). This document reports on progress made during Phase III. The report is divided into three major sections. The first deals with the Hydraulic Injection component. This section of the report describes the progress and milestones associated with the grouting activities of the project. The Phase III tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  3. pH dependence of iron photoreduction in a rocky mountain stream affected by acid mine drainage

    NASA Astrophysics Data System (ADS)

    McKnight, Diane M.; Kimball, Briant A.; Runkel, Robert L.

    2001-07-01

    The redox speciation of dissolved iron and the transport of iron in acidic, metal-enriched streams is controlled by precipitation and dissolution of iron hydroxides, by photoreduction of dissolved ferric iron and hydrous iron oxides, and by oxidation of the resulting dissolved ferrous iron. We examined the pH dependence of these processes in an acidic mine-drainage stream, St Kevin Gulch, Colorado, by experimentally increasing the pH of the stream from about 4·0 to 6·5 and following the downstream changes in iron species. We used a solute transport model with variable flow to evaluate biogeochemical processes controlling downstream transport. We found that at pH 6·4 there was a rapid and large initial loss of ferrous iron concurrent with the precipitation of aluminium hydroxide. Below this reach, ferrous iron was conservative during the morning but there was a net downstream loss of ferrous iron around noon and in the afternoon. Calculation of net oxidation rates shows that the noontime loss rate was generally much faster than rates for the ferrous iron oxidation at pH 6 predicted by Singer and Stumm (1970. Science 167: 1121). The maintenance of ferrous iron concentrations in the morning is explained by the photoreduction of photoreactive ferric species, which are then depleted by noon.

  4. Adsorption of copper, cadmium and zinc on suspended sediments in a stream contaminated by acid mine drainage: The effect of seasonal changes in dissolved organic carbon

    SciTech Connect

    Macalady, D.L.; Ranville, J.F.; Smith, K.S.; Daniel, S.R.

    1991-01-01

    The release of metal-rich, acidic waters from abandoned mining operations is a major problem in Colorado and throughout the Western United States. In Colorado, over 600 km of stream reach are estimated to be affected by such releases (Wentz, 1974). The metals released adversely affect stream biota, including fish. It is therefore important to understand the chemical processes which influence metal transport in these waters. The report details studies of the role of suspended sediments with respect to the transport of several important trace metals in a stream impacted by acid mine drainage. The role of streambed sediments was studied in the same system as part of an earlier project (Acid Mine Drainage: streambed sorption of copper, cadmium and zinc, PB--93-118263).

  5. Suspended culture of sulfate reducing bacteria for the remediation of acid mine drainage

    SciTech Connect

    Misken, K.A.; Figueroa, L.A.

    1993-12-31

    Acid mind drainages are characterized by low pH, and high sulfate and heavy metals concentrations. Conventional treatment technologies address these concerns with high chemical additions producing large volumes of sludge requiring disposal. An anaerobic suspended culture of sulfate reducing bacteria can reduce the metals and sulfate levels by reducing sulfate to sulfide levels by reducing sulfate to sulfate, which can then form precipates with the metal in solution, while increase pH and producing biocarbonate. Readily available and inexpensive organic carbon sources such as wastewater and waste beer were evaluated in serum bottles, and a bench scale sequencing batch reactor was operated using molasses as the organic source. Up to 90% sulfate removal was achieved while reducing iron concentrations to below detection limits. Increases in pH require production of stoichiometrically excess sulfide.

  6. Extremely Acidophilic Protists from Acid Mine Drainage Host Rickettsiales-Lineage Endosymbionts That Have Intervening Sequences in Their 16S rRNA Genes

    PubMed Central

    Baker, Brett J.; Hugenholtz, Philip; Dawson, Scott C.; Banfield, Jillian F.

    2003-01-01

    During a molecular phylogenetic survey of extremely acidic (pH < 1), metal-rich acid mine drainage habitats in the Richmond Mine at Iron Mountain, Calif., we detected 16S rRNA gene sequences of a novel bacterial group belonging to the order Rickettsiales in the Alphaproteobacteria. The closest known relatives of this group (92% 16S rRNA gene sequence identity) are endosymbionts of the protist Acanthamoeba. Oligonucleotide 16S rRNA probes were designed and used to observe members of this group within acidophilic protists. To improve visualization of eukaryotic populations in the acid mine drainage samples, broad-specificity probes for eukaryotes were redesigned and combined to highlight this component of the acid mine drainage community. Approximately 4% of protists in the acid mine drainage samples contained endosymbionts. Measurements of internal pH of the protists showed that their cytosol is close to neutral, indicating that the endosymbionts may be neutrophilic. The endosymbionts had a conserved 273-nucleotide intervening sequence (IVS) in variable region V1 of their 16S rRNA genes. The IVS does not match any sequence in current databases, but the predicted secondary structure forms well-defined stem loops. IVSs are uncommon in rRNA genes and appear to be confined to bacteria living in close association with eukaryotes. Based on the phylogenetic novelty of the endosymbiont sequences and initial culture-independent characterization, we propose the name “Candidatus Captivus acidiprotistae.” To our knowledge, this is the first report of an endosymbiotic relationship in an extremely acidic habitat. PMID:12957940

  7. Acid mine drainage prevention, control and treatment technology development for the Stockett/Sand Coulee area. Topical report, March 1, 1995--March 31, 1996

    SciTech Connect

    Brown, T.

    1996-12-31

    The project was initiated to assist the State of Montana to develop a methodology to ameliorate acid mine drainage problems associated with the abandoned mines located in the Stockett/Sand Coulee area near Great Falls, Montana. Extremely acidic water is continuously discharging from abandoned coal mines in the Stockett/Sand Coulee area at an estimated rate of greater than 600 acre-feet per year (about 350 to 400 gallons per minute). Due to its extreme acidity, the water is unusable and is contaminating other water supplies. Most of the local alluvial aquifers have been contaminated, and nearly 5% of the private wells that were tested in the area during the mid-1980`s showed some degree of contamination. Significant government money has been spent replacing water supplies due to the magnitude of this problem. In addition, millions of dollars have been spent trying to remediate acid mine drainage occurring in this coal field. To date, the techniques used have focused on the management and containment of mine waters, rather than designing technologies that would prevent the formation of acid mine drainage.

  8. Evaluation of layered and mixed passive treatment systems for acid mine drainage.

    PubMed

    Jeen, Sung-Wook; Mattson, Bruce

    2016-11-01

    Laboratory column tests for passive treatment systems for mine drainage from a waste rock storage area were conducted to evaluate suitable reactive mixture, system configuration, effects of influent water chemistry, and required residence time. Five columns containing straw, chicken manure, mushroom compost, and limestone (LS), in either layered or mixed configurations, were set up to simulate the treatment system. The results showed that all of the five columns removed metals of concern (i.e. Al, Cd, Co, Cu, Fe, Ni, and Zn) with a residence time of 15 h and greater. Reaction mechanisms responsible for the removal of metals may include sulfate reduction and subsequent sulfide precipitation, precipitation of secondary carbonates and hydroxides, co-precipitation, and sorption on organic substrates and secondary precipitates. The results suggest that the mixed systems containing organic materials and LS perform better than the layered systems, sequentially treated by organic and LS layers, due to the enhanced pH adjustment, which is beneficial to bacterial activity and precipitation of secondary minerals. The column tests provide a basis for the design of a field-scale passive treatment system, such as a reducing and alkalinity producing system or a permeable reactive barrier. PMID:26998668

  9. Effect of imposed anaerobic conditions on metals release from acid-mine drainage contaminated streambed sediments.

    PubMed

    Butler, Barbara A

    2011-01-01

    Remediation of streams influenced by mine-drainage may require removal and burial of metal-containing bed sediments. Burial of aerobic sediments into an anaerobic environment may release metals, such as through reductive dissolution of metal oxyhydroxides. Mining-impacted aerobic streambed sediments collected from North Fork Clear Creek, Colorado were held under anaerobic conditions for four months. Eh, pH, and concentrations of Cd, Cu, Fe, Mn, and Zn (filtered at 1.5 μm, 0.45 μm, and 0.2 μm), sulfate, and dissolved organic carbon (DOC) were monitored in stream water/sediment slurries. Two sediment size fractions were examined (2 mm-63 μm and <63 μm). Sequential extractions evaluated the mineral phase with which metals were associated in the aerobic sediment. Released Cu was re-sequestered within 5 weeks, while Fe and Mn still were present at 16 weeks. Mn concentration was lower than in the initial stream water at and beyond 14 weeks for the smaller sized sediment. Cd was not released from either sediment size fraction. Zn was released at early times, but concentrations never exceeded those present in the initial stream water and all was re-sequestered over time. The greatest concentrations of Cu, Fe, Mn, and Zn were associated with the Fe/Mn reducible fraction. Sulfate and Fe were strongly correlated (r = 0.90), seeming to indicate anaerobic dissolution of iron oxy-hydroxy-sulfate minerals. DOC and sulfate were strongly correlated (r = 0.81), with iron having a moderately strong correlation with DOC (r = 0.71). Overall concentrations of DOC, sulfate, Cu, Fe, and Zn and pH were significantly higher (p < 0.05) in the water overlying the small sized sediment samples, while the concentrations of Mn released from the larger sized sediment samples were greater. PMID:20709348

  10. Use of phosphate materials as ameliorants for acid mine drainage. Volume 2. Use of phosphate clay in revegetation of minesoils: A greenhouse study. Final report

    SciTech Connect

    Bhumbla, D.K.; Sencindiver, J.C.

    1989-01-01

    Acid mine drainage from the high sulfur coal mining industry in West Virginia, western Pennsylvania, Ohio, western Kentucky and Illinois is the primary environmental problem facing this industry. Mine acid drainage has adversely affected streams and surface revegetation of abandoned mined lands. The effectiveness of application of phosphatic clay slurries in the revegetation of mine soils is examined in a greenhouse study. It is concluded that phosphatic clays have a potential for amending minesoils for revegetation purposes. Phosphatic clay treatment produced higher crop yields than treatments with rock phosphate or monocalcium phosphate. In addition, phosphatic clays improved uptake of macronutrients in plants grown on both shale and sandstone minesoils.

  11. Disposal of Fluidized Bed Combustion Ash in an Underground Mine to Control Acid Mine Drainage and Subsidence

    SciTech Connect

    1998-08-31

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion (FBC) ash). Success will be measured in terms of technical feasibility of the approach (i.e. YO void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). During Phase Ill the majority of the activity involves completing two full scale demonstration projects. The eleven acre Longridge mine in Preston County will be filled with 53,000 cubic yards of grout during the spring of 1998 and monitored for following year. The second demonstration involves stowing 2000 tons of ash into an abandoned mine to demonstrate the newly redesigned Burnett Ejector. This demonstration is anticipated to take place during the winter of 1997. This document will report on progress made during Phase Ill. The report will be divided into four major sections. The first will be the Hydraulic Injection component. This section of the report will report on progress and milestones associated with the grouting activities of the project. The Phase Ill tasks of Economic Analysis and Regulatory Analysis will be covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase Ill (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  12. Use of man-made impoundment in mitigating acid mine drainage in the North Branch Potomac River

    NASA Astrophysics Data System (ADS)

    Diamond, Jerome M.; Bower, William; Gruber, David

    1993-03-01

    The US Department of the Army, Baltimore District Corps of Engineers, oversees a long-term monitoring study to assess and evaluate effects of the Jennings-Randolph reservoir on biota in the North Branch Potomac River. The reservoir was intended, in part, to mitigate effects of acid mine drainage originating in upstream and headwater areas. The present study assessed recovery of benthos and fish in this system, six years after completion of the reservoir. Higher pH and lower iron and sulfate concentrations were observed upstream of the reservoir compared to preimpoundment conditions, suggesting better overall water quality in the upper North Branch. Water quality improved slightly directly downstream of the reservoir. However, the reservoir itself was poorly colonized by macrophytes and benthic organisms, and plankton composition suggested either metal toxicity and/or nutrient limitation. One large tributary to the North Branch and the reservoir (Stony River) was shown to have high (and possibly toxic) levels of manganese, iron, zinc, and aluminum due to subsurface coal mine drainage. Macroinvertebrate diversity and number of taxa were higher in sites downstream of the reservoir in the present study. Compared with previous years, the present study suggested relatively rapid recovery in the lower North Branch due to colonization from two major unimpacted tributaries in this system: Savage River and South Branch Potomac. Abundance of certain mayfly species across sites provided the most clear evidence of longitudinal gradients in water quality parameters and geomorphology. Fish data were consistent with macroinvertebrate results, but site-to-site variation in species composition was greater. Data collected between 1982 and 1987 suggested that certain fish species have unsuccessfully attempted to colonize sites directly downstream of the reservoir despite the more neutral pH water there. Our results show that recovery of biota in the North Branch Potomac was attributed

  13. Effects of Long-Term Acid-Mine Drainage Contamination on Diversity and Activity of Sulfate-Reducing Bacteria in a Natural Salt Marsh.

    NASA Astrophysics Data System (ADS)

    Moreau, J. W.; Banfield, J. F.

    2003-12-01

    Constructed wetlands have been studied as sites or analogs for in situ bioremediation of metal contaminants from acid mine drainage (AMD) or industrial sources (e.g. Webb et al. 1998). Wetlands bioremediation necessarily invokes the ubiquity and robustness of sulfate-reducing bacteria (SRB) to sequester dissolved metals into various poorly soluble metal-sulfides (e.g. PbS, CdS). However, few studies of natural wetlands under long-term ecological forcing by AMD or other contaminant sources are available for context. We are investigating the microbial diversity, mineralogy and geochemistry of a highly contaminated salt marsh along the East Central San Francisco Bay. For nearly a half-century, areas within this marsh have received acidic and/or metal-rich groundwaters from near-surface pyrite tailings (transported there from Iron Mountain Mine, near Redding, CA) and local industrial sources (e.g. paint and explosives manufacturers). Sediment cores (30-40 cm long) were taken from six contaminated sites in the marsh with pH range of ˜2 to ˜8. Previous analyses (URS Corp. 2001) reported As, Cd, Cu, Se, Zn, and Pb present in sediments at extremely high concentrations (100s of ppm), yet our ICP-AES analyses of pore waters showed only As present at concentrations of 10-50 ppb. We infer, from high-resolution transmission electron microscope (HRTEM) studies of biogenic (SRB biofilm) ZnS (Moreau et al. 2003, in review) and marsh sediments, that contaminant metals have been sequestered into aggregates of nanocrystalline metal-sulfides. Continuous-flow isotope ratio mass spectrometer (CF-IRMS) analyses of pore-water sulfate and sedimentary sulfides allow resolution of contributions to dissolved sulfate and sulfide from tailings oxidation and dissimilatory sulfate reduction. Sulfate analyses from subsections of three cores (pH 2-3, 6-7, 7-8, respectively) all yield δ 34S values consistent with bacterial sulfate reduction. We note that all three cores also contain very fine

  14. Enhancing the Attenuation of Acid-Mine Drainage at Davis Mine, Rowe, Massachusetts via Installation of a Permeable Reactive Barrier.

    NASA Astrophysics Data System (ADS)

    Gillmor, A. M.; Yuretich, R. F.

    2008-12-01

    Acid Mine Drainage affects thousands of streams in the United States, sustaining the need for low-cost passive treatment options. Davis Mine, a 100 years-abandoned FeS2 mine in Western Massachusetts, is representative of the types of mines best suited for passive treatments; fairly remote, abandoned, and discharging moderately affected water (pH <3, Fe >100mg/L, SO42- >500mg/L) and is a good candidate for a 'starting point' of low-cost, low environmental impact remediation. We here report the shifts in pH, SO42-, and Fe following placement of reactive fill (50% CaMg(CO3)2, 25% cow manure, 25% seaweed compost) in a permeable reactive barrier placed below ground mid-way along the acidic effluent's path. Yearlong monitoring of water from 1 multi-level well (with ports in the shallow groundwater, middle groundwater, and bedrock) placed within the tailings pile over a previous year (2003-2004) showed for the three levels, respectively; pH 3.16, 4.24, and 4.04, Fe average concentrations of 4.5 mg/L, 6.5 mg/L, and 3.2 mg/L, and SO42- average concentrations of 235mg/L, 330mg/L, and 292 mg/L. One year (2007-2008) after placement of remediation mix, the three levels now average respectively; pH 4.16, 4.60, and 4.53, Fe concentrations of 0.7 mg/L, 4.8 mg/L, and 1.4 mg/L, and SO42- concentrations of 217 mg/L, 294 mg/L, and 266 mg/L. The most noticeable improvement in pH is seen in the shallow groundwater, consistent with its proximity to the reactive fill depth. Although complex microbial communities have been characterized at the site, uncertainty remains as to whether they are active in this case, and it is possible that these results may be explained solely by neutralization reactions. Results of this study indicate a good likelihood that this low environmental impact remediation could be effective.

  15. [Isolation, identification and oxidizing characterization of an iron-sulfur oxidizing bacterium LY01 from acid mine drainage].

    PubMed

    Liu, Yu-jiao; Yang, Xin-ping; Wang, Shi-mei; Liang, Yin

    2013-05-01

    An acidophilic iron-sulfur oxidizing bacterium LY01 was isolated from acid mine drainage of coal in Guizhou Province, China. Strain LY01 was identified as Acidithiobacillusferrooxidans by morphological and physiological characteristics, and phylogenetic analysis of its 16S rRNA gene sequence. Strain LY01 was able to grow using ferrous ion (Fe2+), elemental sulfur (S0) and pyrite as sole energy source, respectively, but significant differences in oxidation efficiency and bacterial growth were observed when different energy source was used. When strain LY01 was cultured in 9K medium with 44.2 g x L(-1) FeSO4.7H2O as the substrate, the oxidation efficiency of Fe2+ was 100% in 30 h and the cell number of strain LY01 reached to 4.2 x 10(7) cell x mL(-1). When LY01 was cultured in 9K medium with 10 g x L(-1) S0 as the substrate, 6.7% S0 oxidation efficiency, 2001 mg x L(-1) SO4(2-) concentration and 8.9 x 10(7) cell x mL(-1) cell number were observed in 21 d respectively. When LY01 was cultured with 30 g x L(-1) pyrite as the substrate, the oxidation efficiency of pyrite, SO4(2-) concentration and cell number reached 10%, 4443 mg x L(-1) and 3.4 x 10(8) cell x mL(-1) respectively in 20 d. The effects of different heavy metals (Ni2+, Pb2+) on oxidation activity of strain LY01 cultured with pyrite were investigated. Results showed that the oxidation activity of strain LY01 was inhibited to a certain extent with the addition of Ni2+ at 10-100 mg x L(-1) to the medium, but the addition of 10-100 mg x L(-1) Pb2+ had no effect on LY01 activity. PMID:23914550

  16. Remediation of acid mine drainage at the friendship hill national historic site with a pulsed limestone bed process

    USGS Publications Warehouse

    Sibrell, P.L.; Watten, B.; Boone, T.

    2003-01-01

    A new process utilizing pulsed fluidized limestone beds was tested for the remediation of acid mine drainage at the Friendship Hill National Historic Site, in southwestern Pennsylvania. A 230 liter-per-minute treatment system was constructed and operated over a fourteen-month period from June 2000 through September 2001. Over this period of time, 50,000 metric tons of limestone were used to treat 50 million liters of water. The influent water pH was 2.5 and acidity was 1000 mg/L as CaCO3. Despite the high potential for armoring at the site, effluent pH during normal plant operation ranged from 5.7 to 7.8 and averaged 6.8. As a result of the high influent acidity, sufficient CO2 was generated and recycled to provide a net alkaline discharge with about 50 mg/L as CaCO3 alkalinity. Additions of commercial CO2 increased effluent alkalinity to as high as 300 mg/L, and could be a useful process management tool for transient high flows or acidities. Metal removal rates were 95% for aluminum (60 mg/L in influent), 50 to 90% for iron (Fe), depending on the ratio of ferrous to ferric iron, which varied seasonally (200 mg/L in influent), and <10% of manganese (Mn) (10 mg/L in influent). Ferrous iron and Mn removal was incomplete because of the high pH required for precipitation of these species. Iron removal could be improved by increased aeration following neutralization, and Mn removal could be effected by a post treatment passive settling/oxidation pond. Metal hydroxide sludges were settled in settling tanks, and then hauled from the site for aesthetic purposes. Over 450 metric tons of sludge were removed from the water over the life of the project. The dried sludge was tested by the Toxicity Characteristics Leaching Protocol (TCLP) and was found to be non-hazardous. Treatment costs were $43,000 per year and $1.08 per m 3, but could be decreased to $22,000 and $0.51 per m3 by decreasing labor use and by onsite sludge handling. These results confirm the utility of the new

  17. Application of fracture-flow hydrogeology to acid-mine drainage at the Bunker Hill Mine, Kellogg, Idaho

    NASA Astrophysics Data System (ADS)

    Lachmar, Thomas E.

    1994-03-01

    The mechanics of groundwater flow through fractured rock has become an object of major research interest during recent years. This project has investigated the flow of groundwater through fractured Precambrian metaquartzite rocks in a portion of the Bunker Hill Mine near Kellogg, Idaho. Groundwater flow through these types of rocks is largely dependent upon the properties of fractures such as faults, joints and relict bedding planes. Groundwater that flows into the mine via the fractures is acidic and is contaminated by heavy metals, which results in a severe acid mine drainage problem. A more complete understanding of how the fractures influence the groundwater flow system is a prerequisite of the evaluation of reclamation alternatives to reduce acid drainage from the mine. Fracture mapping techniques were used to obtain detailed information on the fracture properties observed in the New East Reed drift of the Bunker Hill Mine. The information obtained includes fracture type, orientation, trace length, the number of visible terminations, roughness, waviness, infilling material, and a qualitative measure of the amount of water flowing through each fracture. The hydrogeologic field data collected include routine measurements of the discharge from four individual structural features and four areas where large quantities of water are discharging from vertical rock bolts, the depths to water in three piezometer nests at the ground surface, the pressure variations in four diamond drillholes, and constant discharge flow tests conducted on three of the diamond drillholes. The field data indicate that relict bedding planes are the primary conduits for groundwater flow, and suggest that the two major joint sets that are present connect water flowing through the discontinuous bedding planes. The three minor joint sets that are present do not seem to have a significant impact on groundwater flow, but along with the two major joint sets may store relatively large quantities of

  18. Using environmental isotopes to characterize hydrologic processes of the Nelson Tunnel acid mine drainage site, West Willow Creek watershed, Creede, CO

    NASA Astrophysics Data System (ADS)

    Krupicka, A.; Williams, M. W.

    2010-12-01

    Acid mine drainage continues to be a pressing ecological issue across the Mountain West. Traditional remediation strategies usually involve the installation of an expensive and unsightly “end-of-pipe” water treatment plant without a full understanding of the overall hydrology of the system. In this study we show how applying water chemistry techniques to investigate water sources, ages, flow paths and residence times in a watershed affected by acid mine drainage can lead to alternative, less expensive methods of reclamation. We use both radiogenic (3H and 14C) and stable (18O and D) environmental isotopes to age waters and characterize the level of surface and groundwater interaction. Tritium content for waters collected in the tunnel was largely found to be 0-3 TU, indicating an age of greater than 50 years. This was supported by 14C values of DIC in tunnel samples that indicated ages and a hydraulic residence time on the order of hundreds to thousands of years. Stable isotopes 18O and D plotted closely to the Global Meteoric Water Line (GMWL). Combined with the heavy faulting and dominant welded volcanic tuffs of the region, this all indicates a system with very little surface-ground water interaction and a long, deep, likely channelized flow path. A future up-gradient pumping test would help confirm these findings and further elucidate the location and mechanism of the system’s primary recharge to the mine workings.

  19. Acid mine treatment with open limestone channels

    SciTech Connect

    Ziemkiewicz, P.F.; Brant, D.L.; Skousen, J.G.

    1996-12-31

    Acid mine drainage (AMD) is often associated with mining of pyritic coal and metal deposits. Typical AMD associated with coal mines in the eastern US can have acidity and iron concentrations ranging from the teens to the thousands of mg/l. Aluminum and manganese can be present in concentrations ranging from zero to the low hundreds of mg/l. Much attention has been devoted to developing inexpensive, limestone (LS)-based systems for treating AMID with little or no maintenance. However, LS tends to coat with metal hydroxides when exposed to AMID in an oxidized state, a process known as {open_quotes}armoring{close_quotes}. It is generally assumed that once armored, LS ceases to neutralize acid. Another problem is that the hydroxides tend to settle into plug the pore spaces in LS beds forcing water to move around rather than through the LS. While both are caused by the precipitation of metal hydroxides, armoring and plugging are two different problems. Plugging of LS pores can be avoided by maintaining a high flushing rate through the LS bed. Armoring, however, occurs regardless of water velocity. This study investigated the influence of armoring on LS solubility and the implications of armoring and plugging on the construction of open (oxidizing) LS channels for treating AMD. We evaluated the AMID treatment performance of armored and unarmored LS in oxidizing environments both in laboratory and field studies.

  20. High-frequency, long-duration water sampling in acid mine drainage studies: a short review of current methods and recent advances in automated water samplers

    USGS Publications Warehouse

    Chapin, Thomas

    2015-01-01

    Hand-collected grab samples are the most common water sampling method but using grab sampling to monitor temporally variable aquatic processes such as diel metal cycling or episodic events is rarely feasible or cost-effective. Currently available automated samplers are a proven, widely used technology and typically collect up to 24 samples during a deployment. However, these automated samplers are not well suited for long-term sampling in remote areas or in freezing conditions. There is a critical need for low-cost, long-duration, high-frequency water sampling technology to improve our understanding of the geochemical response to temporally variable processes. This review article will examine recent developments in automated water sampler technology and utilize selected field data from acid mine drainage studies to illustrate the utility of high-frequency, long-duration water sampling.

  1. Development of an enzyme-linked immunosorbent assay to determine the numbers of chemolithotrophic bacteria at acid-mine-drainage sites. Technical report (Final)

    SciTech Connect

    Blake, R.C.; Revis, N.W.; Holdsworth, G.

    1990-09-01

    Thiobacillus ferrooxidans is a prominent member of a group of chemo-lithotrophic bacteria that bear principal responsibility for the formation of acid mine drainage. A prototype enzyme-linked immunosorbent assay (ELISA) for enumerating and qualifying T. ferrooxidans was assembled and characterized. The immunoassay protocol consisted of sequential incubations of the sample with (i) the primary antibody, (ii) the enzyme-labeled secondary antibody, and (iii) a chromogenic substrate specific for the enzyme lable. The necessary reagents comprised primary polyclonal rabbit antibodies directed against T. ferrooxidans ATCC 23270, alkaline phosphatase-copled goat anti-rabbit polyclonal antibodies, and phenolphrhalein monophosphate. The ELISA developed herein correctly identified whether iron-oxidizing bacteria were present in each of 4 samples supplied and analyzed by an independent laboratory. Sufficient preliminary data was obtained to warrant further research and development activities.

  2. EFFECT OF pH, IONIC STRENGTH, DISSOLVED ORGANIC CARBON, TIME, AND PARTICLE SIZE ON METALS RELEASE FROM MINE DRAINAGE IMPACTED STREAMBED SEDIMENTS

    EPA Science Inventory

    Acid-mine drainage (AMD) input to a stream typically results in the stream having a reduced pH, increased concentrations of metals and salts, and decreased biological productivity. Removal and/or treatment of these AMD sources is desired to return the impacted stream(s) to initi...

  3. Eukaryote-dominated Microbial Communities That Build Iron-Stromatolites in Acid Mine Drainage, Western Indiana: An Analog for Proterozoic Banded Iron Formations and Oxygenation of the Early Atmosphere?

    NASA Astrophysics Data System (ADS)

    Hasiotis, S. T.; Brake, S. S.; Dannelly, H. K.; Duncan, A.

    2001-03-01

    Eukaryote-dominated microbial communities build iron-rich stromatolites in acid mine drainage at several reclaimed coal mine sites in western Indiana, which can serve as an analog for Proterozoic iron-rich deposits and the oxygenation of the early atmosphere.

  4. SITE EVALUATION OF INNOVATIVE SEMI-PASSIVE ACID MINE DRAINAGE TREATMENT TECHNOLOGIES AT THE SUMMITVILLE SUPERFUND SITE, COLORADO

    EPA Science Inventory

    The EPA SITE Program is conducting a detailed sampling and evaluation of two innovative passive mine drainage treatment technologies at the Summitville Superfund Mining site in Southern Colorado. The technologies evaluated include the Aquafix automatic hydraulic lime dispensing s...

  5. Binning of shallowly sampled metagenomic sequence fragments reveals that low abundance bacteria play important roles in sulfur cycling and degradation of complex organic polymers in an acid mine drainage community

    NASA Astrophysics Data System (ADS)

    Dick, G. J.; Andersson, A.; Banfield, J. F.

    2007-12-01

    Our understanding of environmental microbiology has been greatly enhanced by community genome sequencing of DNA recovered directly the environment. Community genomics provides insights into the diversity, community structure, metabolic function, and evolution of natural populations of uncultivated microbes, thereby revealing dynamics of how microorganisms interact with each other and their environment. Recent studies have demonstrated the potential for reconstructing near-complete genomes from natural environments while highlighting the challenges of analyzing community genomic sequence, especially from diverse environments. A major challenge of shotgun community genome sequencing is identification of DNA fragments from minor community members for which only low coverage of genomic sequence is present. We analyzed community genome sequence retrieved from biofilms in an acid mine drainage (AMD) system in the Richmond Mine at Iron Mountain, CA, with an emphasis on identification and assembly of DNA fragments from low-abundance community members. The Richmond mine hosts an extensive, relatively low diversity subterranean chemolithoautotrophic community that is sustained entirely by oxidative dissolution of pyrite. The activity of these microorganisms greatly accelerates the generation of AMD. Previous and ongoing work in our laboratory has focused on reconstrucing genomes of dominant community members, including several bacteria and archaea. We binned contigs from several samples (including one new sample and two that had been previously analyzed) by tetranucleotide frequency with clustering by Self-Organizing Maps (SOM). The binning, evaluated by comparison with information from the manually curated assembly of the dominant organisms, was found to be very effective: fragments were correctly assigned with 95% accuracy. Improperly assigned fragments often contained sequences that are either evolutionarily constrained (e.g. 16S rRNA genes) or mobile elements that are

  6. Oxycline formation induced by Fe(II) oxidation in a water reservoir affected by acid mine drainage modeled using a 2D hydrodynamic and water quality model - CE-QUAL-W2.

    PubMed

    Torres, Ester; Galván, Laura; Cánovas, Carlos Ruiz; Soria-Píriz, Sara; Arbat-Bofill, Marina; Nardi, Albert; Papaspyrou, Sokratis; Ayora, Carlos

    2016-08-15

    The Sancho reservoir is an acid mine drainage (AMD)-contaminated reservoir located in the Huelva province (SW Spain) with a pH close to 3.5. The water is only used for a refrigeration system of a paper mill. The Sancho reservoir is holomictic with one mixing period per year in the winter. During this mixing period, oxygenated water reaches the sediment, while under stratified conditions (the rest of the year) hypoxic conditions develop at the hypolimnion. A CE-QUAL-W2 model was calibrated for the Sancho Reservoir to predict the thermocline and oxycline formation, as well as the salinity, ammonium, nitrate, phosphorous, algal, chlorophyll-a, and iron concentrations. The version 3.7 of the model does not allow simulating the oxidation of Fe(II) in the water column, which limits the oxygen consumption of the organic matter oxidation. However, to evaluate the impact of Fe(II) oxidation on the oxycline formation, Fe(II) has been introduced into the model based on its relationship with labile dissolved organic matter (LDOM). The results show that Fe oxidation is the main factor responsible for the oxygen depletion in the hypolimnion of the Sancho Reservoir. The limiting factors for green algal growth have also been studied. The model predicted that ammonium, nitrate, and phosphate were not limiting factors for green algal growth. Light appeared to be one of the limiting factors for algal growth, while chlorophyll-a and dissolved oxygen concentrations could not be fully described. We hypothesize that dissolved CO2 is one of the limiting nutrients due to losses by the high acidity of the water column. The sensitivity tests carried out support this hypothesis. Two different remediation scenarios have been tested with the calibrated model: 1) an AMD passive treatment plant installed at the river, which removes completely Fe, and 2) different depth water extractions. If no Fe was introduced into the reservoir, water quality would significantly improve in only two years

  7. Effects of some components of acid-mine drainage and acid deposition on the spermatozoa of longear sunfish, Lepomis megalotis

    SciTech Connect

    Pearson, B.J.

    1983-01-01

    The effects of low pH and the metals aluminum, zinc, and cadmium, components of acid-mine effluents and acid deposition, on spermatozoa of longear sunfish, Lepomis megalotis, were investigated. Sperm were exposed to solutions of 400 ppm aluminum chloride, 50 ppm zinc chloride, 2 ppm cadmium chloride, separately and in combination, at pH values of 6.9, 4.8, and 3.8. Sperm were additionally exposed to test solutions in which the metal salt concentration was reduced by one-half and observed for changes in motility and in the ability to exclude stain. All test solutions at a low pH were deleterious, the greatest damage occurring in solutions of a combination of all 3 metal chlorides and of aluminum chloride separately. Motility tests showed that both full and reduced metal concentrations had significant effects on motility. Staining tests were supportive of motility test results and indicated that in most cases shorter exposure times did not significantly improve survival rates. It was generally found that a decrease in pH increased the effects of each metal separately and when combined. Aluminum, zinc, and cadmium chlorides appeared to act antagonistically when tested in combination. It was concluded that the components of acid waters which were tested have deleterious effects on longer spermatozoa, reducing their viability and thereby reducing reproductive success of the species.

  8. Assessing the concentration, speciation, and toxicity of dissolved metals during mixing of acid-mine drainage and ambient river water downstream of the Elizabeth Copper Mine, Vermont, USA

    USGS Publications Warehouse

    Balistrieri, L.S.; Seal, R.R., II; Piatak, N.M.; Paul, B.

    2007-01-01

    The authors determine the composition of a river that is impacted by acid-mine drainage, evaluate dominant physical and geochemical processes controlling the composition, and assess dissolved metal speciation and toxicity using a combination of laboratory, field and modeling studies. Values of pH increase from 3.3 to 7.6 and the sum of dissolved base metal (Cd + Co + Cu + Ni + Pb + Zn) concentrations decreases from 6270 to 100 ??g/L in the dynamic mixing and reaction zone that is downstream of the river's confluence with acid-mine drainage. Mixing diagrams and PHREEQC calculations indicate that mixing and dilution affect the concentrations of all dissolved elements in the reach, and are the dominant processes controlling dissolved Ca, K, Li, Mn and SO4 concentrations. Additionally, dissolved Al and Fe concentrations decrease due to mineral precipitation (gibbsite, schwertmannite and ferrihydrite), whereas dissolved concentrations of Cd, Co, Cu, Ni, Pb and Zn decrease due to adsorption onto newly formed Fe precipitates. The uptake of dissolved metals by aquatic organisms is dependent on the aqueous speciation of the metals and kinetics of complexation reactions between metals, ligands and solid surfaces. Dissolved speciation of Cd, Cu, Ni and Zn in the mixing and reaction zone is assessed using the diffusive gradients in thin films (DGT) technique and results of speciation calculations using the Biotic Ligand Model (BLM). Data from open and restricted pore DGT units indicate that almost all dissolved metal species are inorganic and that aqueous labile or DGT available metal concentrations are generally equal to total dissolved concentrations in the mixing zone. Exceptions occur when labile metal concentrations are underestimated due to competition between H+ and metal ions for Chelex-100 binding sites in the DGT units at low pH values. Calculations using the BLM indicate that dissolved Cd and Zn species in the mixing and reaction zone are predominantly inorganic

  9. Effectivenes of lime kiln flue dust in preventing acid mine drainage at the Kauffman Surface Coal Mine, Clearfield County, Pennsylvania

    SciTech Connect

    Rose, A.W.; Parizek, R.R.; Phelps, L.B.

    1995-09-01

    A careful test of alkaline addition combined with special handling has been performed during mining of 27 acres of coal overlain by slightly to moderately pyritic overburden at the Kauffman Mine. Overburden holes indicate alkaline deficiencies of up to 1090 tons CaCO{sub 3}/acre. Sulfur contents for 1- to 3-foot intervals average 0.26%S and range up to 4.4%. An adjacent min produces severe AMD. Lime kiln flue dust, a waste product, was added in amounts adequate to neutralize maximum potential acidity. High-S zones were special-handled into compacted pods up to 2 ft. thick and covered by about 30% of the total lime requirement. About half the lime was spread on the surface prior to blasting and mixed during subsequent handling; the remaining lime was spread on the pit floor and beneath the topsoil. Over the period up to 1.5 years after mining, water in backfill and monitoring wells has pH of 6 to 7, alkalinity exceeding acidity, and generally low Fe, Al and Mn, indicating that procedure is a success. However, concurrent experiments with 400-ton test cells indicate that prompt addition of lime, and compaction of the material may be crucial for successful results.

  10. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence. Quarterly report, March 1--May 31, 1998

    SciTech Connect

    1998-09-01

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion, FBC, ash). Success will be measured in terms of technical feasibility of the approach, cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). Phase 1 of the project was completed in September 1995 and was concerned with the development of the grout and a series of predictive models. These models were verified through the Phase 2 field phase and will be further verified in the large scale field demonstration of Phase 3. The verification will allow the results to be packaged in such a way that the technology can be easily adapted to different site conditions. Phase 2 was successfully completed with 1,000 cubic yards of grout being injected into Anker Energy`s Fairfax mine. The grout flowed over 600 feet from a single injection borehole. The grout achieved a compressive strength of over 1,000 psi (twice the level that is needed to guarantee subsidence control). Phase 3 is to take 26 months and will be a full scale test at Anker`s eleven acre Longridge mine site.

  11. Mineralogy of the hardpan formation processes in the interface between sulfide-rich sludge and fly ash: Applications for acid mine drainage mitigation

    SciTech Connect

    Perez-Lopez, R.; Nieto, J.M.; Alvarez-Valero, A.M.; De Almodovar, G.R.

    2007-11-15

    In the present study, experiments in non-saturated leaching columns were conducted to characterize the neoformed phases that precipitate at the interface between two waste residues having different chemical characteristics: an acid mine drainage producer residue (i.e., pyritic sludge) and an acidity neutralizer residue (i.e., coal combustion fly ash). A heating source was placed on top of one of the columns to accelerate oxidation and precipitation of newly formed phases, and thus, to observe longer-scale processes. When both residues are deposited together, the resulting leachates are characterized by alkaline pH, and low sulfate and metal concentrations. Two mechanisms help to improve the quality of the leachates. Over short-time scales, the leaching of pyrite at high pH (as a consequence of fly ash addition) favors the precipitation of ferrihydrite, encapsulating the pyrite grains and attenuating the oxidation process. Over longer time scales, a hardpan is promoted at the interface between both residues due to the precipitation of ferrihydrite, jarosite, and a Ca phase-gypsum or aragonite, depending on carbonate ion activity. Geochemical modeling of leachates using PHREEQC software predicted supersaturation in the observed minerals. The development of a relatively rigid crust at the interface favors the isolation of the mining waste from weathering processes, helped by the cementation of fly ash owing to aragonite precipitation, which ensures total isolation and neutralization of the mine residues.

  12. Effectiveness of covers and liners made of red mud bauxite and/or cement kiln dust for limiting acid mine drainage

    SciTech Connect

    Duchesne, J.; Doye, I.

    2005-08-01

    This paper presents a laboratory investigation to evaluate the capacity of alkaline residues to inhibit acid mine drainage. Column tests were used to evaluate the geochemical behavior of cement kiln dust (CKD) and red mud bauxite (RMB) used as covers, liners, or mixed with acid producing tailings and waste rocks. The most important indicators of neutralization are pH and the concentrations of metals in solution. Initial leachate pH of samples with an alkaline cover composed of 10% CKD or 10% of a mixture of CKD and RMB was low, but rapidly increased to near 7.0 and stabilized for the duration of this study. The use of alkaline materials as a liner had a positive effect on the reduction of Fe, SO{sub 4} and other metals such as Cu and Zn concentrations and the number of viable bacteria. In the cases where the alkaline layer was used as a liner or mixed with the waste rocks, near neutral pH values were rapidly reached in the leachate. However, in these columns the leachate pH values decreased over time.

  13. Biochemical passive reactors for treatment of acid mine drainage: Effect of hydraulic retention time on changes in efficiency, composition of reactive mixture, and microbial activity.

    PubMed

    Vasquez, Yaneth; Escobar, Maria C; Neculita, Carmen M; Arbeli, Ziv; Roldan, Fabio

    2016-06-01

    Biochemical passive treatment represents a promising option for the remediation of acid mine drainage. This study determined the effect of three hydraulic retention times (1, 2, and 4 days) on changes in system efficiency, reactive mixture, and microbial activity in bioreactors under upward flow conditions. Bioreactors were sacrificed in the weeks 8, 17 and 36, and the reactive mixture was sampled at the bottom, middle, and top layers. Physicochemical analyses were performed on reactive mixture post-treatment and correlated with sulfate-reducing bacteria and cellulolytic and dehydrogenase activity. All hydraulic retention times were efficient at increasing pH and alkalinity and removing sulfate (>60%) and metals (85-99% for Fe(2+) and 70-100% for Zn(2+)), except for Mn(2+). The longest hydraulic retention time (4 days) increased residual sulfides, deteriorated the quality of treated effluent and negatively impacted sulfate-reducing bacteria. Shortest hydraulic retention time (1 day) washed out biomass and increased input of dissolved oxygen in the reactors, leading to higher redox potential and decreasing metal removal efficiency. Concentrations of iron, zinc and metal sulfides were high in the bottom layer, especially with 2 day of hydraulic retention time. Sulfate-reducing bacteria, cellulolytic and dehydrogenase activity were higher in the middle layer at 4 days of hydraulic retention time. Hydraulic retention time had a strong influence on overall performance of passive reactors. PMID:27016821

  14. Column experiments for microbiological treatment of acid mine drainage: low-temperature, low-pH and matrix investigations.

    PubMed

    Tsukamoto, T K; Killion, H A; Miller, G C

    2004-03-01

    The lifetime of traditional sulfate-reducing bacteria (SRB) bioreactors that utilize a source of reducing equivalents contained within the matrix (e.g. manure) is limited by the amount of readily available reducing equivalents within that matrix. In order to extend bioreactor lifetime indefinitely, the addition of known concentrations of alternative reducing equivalents (methanol and ethanol) to a depleted matrix was tested at low pH and low temperatures. Following acclimation, up to 100% efficiencies of reducing equivalents were directed toward sulfate reduction. Alcohol was added in stoichiometric concentrations to remove 50% of the added sulfate (900 mg/L), producing sufficient sulfide to precipitate all of the iron from solution. An average of 42% of the sulfate was removed following acclimation, reflecting 84% efficiency. An average of 93% of the iron was removed (93 mg/L). Bacteria acclimated to ethanol more rapidly than methanol, although both alcohols were effective as carbon sources. Efficient treatment was observed at the lowest temperatures (6 degrees C) and lowest pHs (pH=2.5) tested. The use of ethanol-fed, highly permeable bioreactor matrices of wood chip, pulverized plastic and rock was also examined to determine which of these porous matrices could be implemented in a field bioreactor. Results indicated that >95% of the 100mg/L iron added was removed by all matrices. Sufficient reducing equivalents were added to remove 450 mg/L of sulfate, wood and rock matrices removed approximately 350 mg/L plastic removed approximately 225 mg/L. A study comparing rock size indicated that small rocks removed iron and sulfate more efficiently than medium- and large-size rocks. The results suggest that wood and rock in conjunction with ethanol are viable alternatives to traditional bioreactor matrices. These findings have direct application to semi-passive sustained operation of SRB bioreactors for treatment of acidic drainage at remote sites. PMID:15016517

  15. Sorption studies of Zn(II) and Cu(II) onto vegetal compost used on reactive mixtures for in situ treatment of acid mine drainage.

    PubMed

    Gibert, Oriol; de Pablo, Joan; Cortina, José Luis; Ayora, Carlos

    2005-08-01

    The efficiency of the sulphate reducing bacteria-based in situ treatment of acid mine drainage is often limited by the low degradability of the current carbon sources, typically complex plant-derived materials. In such non-sulphate-reducing conditions, field and laboratory experiences have shown that mechanisms other than sulphide precipitation should be considered in the metal removal, i.e. metal (oxy)hydroxides precipitation, co-precipitation with these precipitates, and sorption onto the organic matter. The focus of the present paper was to present some laboratory data highlighting the Zn and Cu sorption on vegetal compost and to develop a general and simple model for the prediction of their distribution in organic-based passive remediation systems. The model considers two kinds of sorption sites ( succeeds SO(2)H(2)) and the existence of monodentate and bidentate metal-binding reactions, and it assumes that only free M(2+) species can sorb onto the compost surface. The acid-base properties of the compost were studied by means of potentiometric titrations in order to identify the nature of the involved surface functional groups and their density. The distribution coefficient (K(D)) for both Zn and Cu were determined from batch experiments as a function of pH and metal concentration. The model yielded the predominant surface complexes at the experimental conditions, being succeeds SO(2)Zn for Zn and succeeds SO(2)HCu(+) and ( succeeds SO(2)H)(2)Cu for Cu, with log K(M) values of -2.10, 3.36 and 4.65, respectively. The results presented in this study have demonstrated that the proposed model provides a good description of the sorption process of Zn and Cu onto the vegetal compost used in these experiments. PMID:15992854

  16. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence. Quarterly report, December 1, 1996--February 28, 1997

    SciTech Connect

    1997-12-31

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion -- FBC ash). Success will be measured in terms of technical feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). During Phase 3 the majority of the activity involves completing two full scale demonstration projects. The eleven acre Longridge mine in Preston County will be filled with 53,000 cubic yards of grout during the summer of 1997 and monitored for the following year. The second demonstration involves stowing 2,000 tons of ash into an abandoned mine to demonstrate the newly redesigned Burnett Ejector. This demonstration is anticipated to take place during Summer 1997, as well. This document will report on progress made during Phase 3. The report will be divided into four major sections. The first will be the Hydraulic Injection component. This section of the report will report on progress and milestones associated with the grouting activities of the project. The Phase 3 tasks of Economic Analysis and Regulatory Analysis will be covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase 3 (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  17. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence. Quarterly report, December 1, 1996--February 28, 1997

    SciTech Connect

    1997-12-31

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion-FBC ash). Success will be measured in terms of technical feasibility of the approach (i.e. % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). During Phase 3 the majority of the activity involves completing two full scale demonstration projects. The eleven acre Longridge mine in Preston County will be filled with 53,000 cubic yards of grout during the summer of 1997 and monitored for the following year. The second demonstration involves stowing 2,000 tons of ash into an abandoned mine to demonstrate the newly redesigned Burnett Ejector. This demonstration is anticipated to take place during Summer 1997, as well. This document will report on progress made during Phase 3. The report will be divided into four major sections. The first will be the Hydraulic Injection component. This section of the report will report on progress and milestones associated with the grouting activities of the project. The Phase 3 tasks of Economic Analysis and Regulatory Analysis is covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase 3 (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine. The Gantt Chart on the following page details progress by task.

  18. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence. Quarterly report, September 1--November 30, 1997

    SciTech Connect

    1997-12-31

    This project will evaluate the technical, economic and environmental feasibility of filling abandoned underground mine voids with alkaline, advanced coal combustion wastes (Fluidized Bed Combustion (FBC) ash). Success will be measured in terms of technical feasibility of the approach (i.e., % void filling), cost, environmental benefits (acid mine drainage and subsidence control) and environmental impacts (noxious ion release). During Phase 3 the majority of the activity involves completing two full scale demonstration projects. The eleven acre Longridge mine in Preston County will be filled with 53,000 cubic yards of grout during the spring of 1998 and monitored for following year. The second demonstration involves stowing 2,000 tons of ash into an abandoned mine to demonstrate the newly redesigned Burnett Ejector. This demonstration is anticipated to take place during the winter of 1997. This document will report on progress made during Phase 3. The report will be divided into four major sections. The first will be the Hydraulic Injection component. This section of the report will report on progress and milestones associated with the grouting activities of the project. The Phase 3 tasks of Economic Analysis and Regulatory Analysis will be covered under this section. The second component is Pneumatic Injection. This section reports on progress made towards completing the demonstration project. The Water Quality component involves background monitoring of water quality and precipitation at the Phase 3 (Longridge) mine site. The last component involves evaluating the migration of contaminants through the grouted mine. A computer model has been developed in earlier phases and will model the flow of water in and around the grouted Longridge mine.

  19. Community Genomic and Proteomic Analyses of Chemoautotrophic Iron-Oxidizing "Leptospirillum rubarum" (Group II) and "Leptospirillum ferrodiazotrophum" (Group III) Bacteria in Acid Mine Drainage Biofilms

    SciTech Connect

    Goltsman, Daniela; Denef, Vincent; Singer, Steven; Verberkmoes, Nathan C; Lefsrud, Mark G; Mueller, Ryan; Dick, Gregory J.; Sun, Christine; Wheeler, Korin; Zelma, Adam; Baker, Brett J.; Hauser, Loren John; Land, Miriam L; Shah, Manesh B; Thelen, Michael P.; Hettich, Robert {Bob} L; Banfield, Jillian F.

    2009-01-01

    We analyzed near-complete population (composite) genomic sequences for coexisting acidophilic iron-oxidizing Leptospirillum group II and III bacteria (phylum Nitrospirae) and an extrachromosomal plasmid from a Richmond Mine, Iron Mountain, CA, acid mine drainage biofilm. Community proteomic analysis of the genomically characterized sample and two other biofilms identified 64.6% and 44.9% of the predicted proteins of Leptospirillum groups II and III, respectively, and 20% of the predicted plasmid proteins. The bacteria share 92% 16S rRNA gene sequence identity and >60% of their genes, including integrated plasmid-like regions. The extrachromosomal plasmid carries conjugation genes with detectable sequence similarity to genes in the integrated conjugative plasmid, but only those on the extrachromosomal element were identified by proteomics. Both bacterial groups have genes for community-essential functions, including carbon fixation and biosynthesis of vitamins, fatty acids, and biopolymers (including cellulose); proteomic analyses reveal these activities. Both Leptospirillum types have multiple pathways for osmotic protection. Although both are motile, signal transduction and methyl-accepting chemotaxis proteins are more abundant in Leptospirillum group III, consistent with its distribution in gradients within biofilms. Interestingly, Leptospirillum group II uses a methyl-dependent and Leptospirillum group III a methyl-independent response pathway. Although only Leptospirillum group III can fix nitrogen, these proteins were not identified by proteomics. The abundances of core proteins are similar in all communities, but the abundance levels of unique and shared proteins of unknown function vary. Some proteins unique to one organism were highly expressed and may be key to the functional and ecological differentiation of Leptospirillum groups II and III.

  20. MINE DRAINAGE CONTROL FROM METAL MINES IN A SUBALPINE ENVIRONMENT - A FEASIBILITY STUDY

    EPA Science Inventory

    Investigations of the McLaren mine and mill areas and the Glengary mine area in the vicinity of Cooke City, Montana, were undertaken from July 1973 through September 1975, to examine the acid mine drainage (AMD) from these sources and determine the feasibility of rehabilitating t...

  1. Bioremediation of Acidic and Metalliferous Drainage (AMD) through organic carbon amendment by municipal sewage and green waste.

    PubMed

    McCullough, Clint D; Lund, Mark A

    2011-10-01

    Pit lakes (abandoned flooded mine pits) represent a potentially valuable water resource in hot arid regions. However, pit lake water is often characterised by low pH with high dissolved metal concentrations resulting from Acidic and Metalliferous Drainage (AMD). Addition of organic matter to pit lakes to enhance microbial sulphate reduction is a potential cost effective remediation strategy. However, cost and availability of suitable organic substrates are often limiting. Nevertheless, large quantities of sewage and green waste (organic garden waste) are often available at mine sites from nearby service towns. We treated AMD pit lake water (pH 2.4) from tropical, North Queensland, Australia, with primary-treated sewage sludge, green waste, and a mixture of sewage and green waste (1:1) in a controlled microcosm experiment (4.5 L). Treatments were assessed at two different rates of organic loading of 16:1 and 32:1 pit water:organic matter by mass. Combined green waste and sewage treatment was the optimal treatment with water pH increased to 5.5 in only 145 days with decreases of dissolved metal concentrations. Results indicated that green waste was a key component in the pH increase and concomitant heavy metal removal. Water quality remediation was primarily due to microbially-mediated sulphate reduction. The net result of this process was removal of sulphate and metal solutes to sediment mainly as monosulfides. During the treatment process NH(3) and H(2)S gases were produced, albeit at below concentrations of concern. Total coliforms were abundant in all green waste-treatments, however, faecal coliforms were absent from all treatments. This study demonstrates addition of low-grade organic materials has promise for bioremediation of acidic waters and warrants further experimental investigation into feasibility at higher scales of application such as pit lakes. PMID:21616580

  2. Spectral-IP Characteristics of Bacterial Activity on Sulfide Mineral Surfaces: Implications for Detection and Environmental Impact Assessment of Acid Mine Drainage.

    NASA Astrophysics Data System (ADS)

    Blackmore, S. R.; Southam, G.; Katsube, J.

    2004-12-01

    Spectral induced polarization (IP) measurements were carried out, over a frequency range of 1.0-106 Hz, on pyrite crystal surfaces colonized by thiobacilli at different growth stages and in `sedimentary systems' with different pyrite-quartz ratios. The purpose was to determine if these varied pyrite-bacteria conditions are reflected in the spectral-IP responses and whether IP, as a geophysical tool, is able to detect and assess the potential for acid mine drainage due to bacterial activity. The study used an Acidithiobacillus ferrooxidans subspecies, isolated from the Kam Kotia mine tailings, Timmins, Ontario, using limiting dilutions in 9K buffer medium (pH 3; (NH4)2SO4, 0.4 g; K2HPO4, 0.1 g; MgSO47H2O, 0.1 g) supplemented with 3.3 g/L of filter sterilized FeSO47H2O as their energy source. Duplicate syringe columns experiments were prepared using varying concentrations of acid-washed silica and/or pyrite (simulating either disseminated or stratified pyritic ore) and colonized with thiobacilli. All columns were maintained under saturating conditions with circumneutral 9K buffer. Each column began with an acidic pH and became more alkaline over the 2-month experiment, typically ending close to the circumneutral pH of the media. The spectral-IP measurements responded directly to bacterial activity, i.e., changes in impedance were observed in all samples. Samples that contained bacteria were higher in impedance (with significant differences observed between frequencies of 10-100000Hz). Over time, scanning electron microscopy revealed increases in the bacterial corrosion surface area, bacterial ferric-sulfate encasement, the number of bacteria colonies and abundance of ferric precipitates. Bacterially induced mineralization was observed as patches in all systems. In the disseminated and stratified environments, the patches covered 8-10% of the grains, predominantly along the fractured mineral edges. In the `massive' 100% pyrite systems, bacteria-mineral patches covered

  3. Major and trace-element analyses of acid mine waters in the Leviathan Mine drainage basin, California/Nevada; October, 1981 to October, 1982

    USGS Publications Warehouse

    Ball, J.W.; Nordstrom, D.K.

    1985-01-01

    Water issuing from the inactive Leviathan open-pit sulfur mine has caused serious degradation of the water quality in the Leviathan/Bryant Creek drainage basin which drains into the East Fork of the Carson River. As part of a pollution abatement project of the California Regional Water Quality Control Board, the U.S. Geological Survey collected hydrologic and water quality data for the basin during 1981-82. During this period a comprehensive sampling survey was completed to provide information on trace metal attenuation during downstream transport and to provide data for interpreting geochemical processes. This report presents the analytical results from this sampling survey. Sixty-seven water samples were filtered and preserved on-site at 45 locations and at 3 different times. Temperature, discharge, pH, and Eh and specific conductance were measured on-site. Concentrations of 37 major and trace constituents were determined later in the laboratory on preserved samples. The quality of the analyses was checked by using two or more techniques to determine the concentrations including d.c.-argon plasma emission spectrometry (DCP), flame and flameless atomic absorption spectrophotometry, UV-visible spectrophotometry, hydride-generation atomic absorption spectrophotometry and ion chromatography. Additional quality control was obtained by comparing measured to calculated conductance, comparing measured to calculated Eh (from Fe-2 +/Fe-3+ determinations), charge balance calculations and mass balance calculations for conservative constituents at confluence points. Leviathan acid mine waters contain mg/L concentrations of As, Cr, Co, Cu, Mn, Ni, T1, V and Zn, and hundreds to thousands of mg/L concentrations of Al, Fe, and sulfate at pH values as low as 1.8. Other elements including Ba, B, Be, Bi, Cd , Mo, Sb, Se and Te are elevated above normal background concentrations and fall in the microgram/L range. The chemical and 34 S/32 S isotopic analyses demonstrate that these

  4. Prediction of Coal ash leaching behavior in acid mine water, comparison of laboratory and field studies

    SciTech Connect

    ANNA, KNOX

    2005-01-10

    Strongly alkaline fluidized bed combustion ash is commonly used to control acid mine drainage in West Virginia coal mines. Objectives include acid neutralization and immobilization of the primary AMD pollutants: iron, aluminum and manganese. The process has been successful in controlling AMD though doubts remain regarding mobilization of other toxic elements present in the ash. In addition, AMD contains many toxic elements in low concentrations. And, each mine produces AMD of widely varying quality. So, predicting the effect of a particular ash on a given coal mine's drainage quality is of particular interest. In this chapter we compare the results of a site-specific ash leaching procedure with two large-scale field applications of FBC ash. The results suggested a high degree of predictability for roughly half of the 25 chemical parameters and poor predictability for the remainder. Of these, seven parameters were successfully predicted on both sites: acidity, Al, B, Ba, Fe, Ni and Zn while electrical conductivity, Ca, Cd, SO4, Pb and Sb were not successfully predicted on either site. Trends for the remaining elements: As, Ag, Be, Cu, Cr, Hg, Mg, Mn, pH, Se Tl and V were successfully predicted on one but not both mine sites.

  5. Dominance of Ferritrophicum populations at an AMD site with rapid iron oxidation

    NASA Astrophysics Data System (ADS)

    Grettenberger, C.; Pearce, A.; Bibby, K. J.; Burgos, W.; Jones, D. S.; Macalady, J.

    2015-12-01

    Acid mine drainage is a major environmental problem affecting watersheds across the globe. Bioremediation of AMD relies on microbial communities to oxidize and thus remove iron from the system. Iron-oxidation rates in AMD environments are highly variable across sites. At Scalp Level Run in Summerset County PA, iron-oxidation rates are five to eight times faster than other coal-associated AMD sites. We examined the microbial community at Scalp Level Run to determine whether a unique microbial community may be responsible for the observed rapid iron-oxidation rates. Using MiSeq sequence tags, 16S rRNA gene clone libraries, and fluorescence in situ hybridization, we found that Scalp Level Run sediments host microbial populations closely related to the betaproteobacterium Ferritrophicum radicicola, an iron-oxidizing species isolated from an acid mine drainage wetland in Virginia. Ferritrophicum spp. was not found at the four other coal-associated AMD sites in the study and is uncommon in the published literature. The influence of Ferritrophicum spp. populations in biogeochemical cycling, specifically their role in determining the iron-oxidation rate at Scalp Level Run is unknown. Therefore, we employed metagenomic sequencing to examine the metabolic potential of the microbial community at Scalp Level Run.

  6. Hydrogeology and geochemistry of acid mine drainage in ground water in the vicinity of Penn Mine and Camanche Reservoir, Calaveras County, California; first-year summary

    USGS Publications Warehouse

    Hamlin, S.N.; Alpers, C.N.

    1995-01-01

    Acid drainage from the Penn Mine in Calaveras County, California, has caused contamination of ground water between Mine Run Dam and Camanche Reservoir. The Penn Mine was first developed in the 1860's primarily for copper and later produced lesser amounts of zinc, lead, silver, and gold from steeply dipping massive sulfide lenses in metamorphic rocks. Surface disposal of sulfidic waste rock and tailings from mine operations has produced acidic drainage with pH values between 2.3 and 2.7 and elevated concentrations of sulfate and metals, including copper, zinc, cadmium, iron, and aluminum. During the mine's operation and after its subsequent abandonment in the late 1950's, acid mine drainage flowed down Mine Run into the Mokelumne River. Construction of Camanche Dam in 1963 flooded part of the Mokelumne River adjacent to Penn Mine. Surface-water diversions and unlined impoundments were constructed at Penn Mine in 1979 to reduce runoff from the mine, collect contaminated surface water, and enhance evaporation. Some of the contaminated surface water infiltrates the ground water and flows toward Camanche Reservoir. Ground- water flow in the study area is controlled by the local hydraulic gradient and the hydraulic characteristics of two principal rock types, a Jurassic metavolcanic unit and the underlying Salt Spring slate. The hydraulic gradient is west from Mine Run impoundment toward Camanche Reservoir. The median hydraulic conductivity was about 10 to 50 times higher in the metavolcanic rock (0.1 foot per day) than in the slate (0.002 to 0.01 foot per day); most flow occurs in the metavolcanic rock where hydraulic conductivity is as high as 50 feet per day in two locations. The contact between the two rock units is a fault plane that strikes N20?W, dips 20?NE, and is a likely conduit for ground-water flow, based on down-hole measurements with a heatpulse flowmeter. Analyses of water samples collected during April 1992 provide a comprehensive characterization of

  7. Removal of phosphorus from wastewater using ferroxysorb sorption media produced from amd sludge

    USGS Publications Warehouse

    Sibrell, P.L.; Tucker, T.W.; Kehler, T.; Fletcher, J.W.

    2008-01-01

    Treatment of acid mine drainage (AMD), whether with lime, limestone, caustic or simple aeration, nearly always results in generation of a metal hydroxide sludge. Disposal of the sludge often constitutes a significant fraction of the operating cost for the AMD treatment plant. Research at the USGS - Leetown Science Center has shown that AMD sludge, with its high content of aluminum and iron oxides, has a high affinity of phosphorus (P). Anthropogenic sources of P are associated with eutrophication and degradation of aquatic environments, resulting in anoxic dead zones in certain sensitive waterways. In this paper, we describe a method of converting the AMD sludge from a liability into an asset - Ferroxysorb P removal media - which can be used to remove excess P from wastewater. Three different Ferroxysorb media samples were produced from differing AMD sources and tested for P removal. Adsorption isotherms confirmed that the media had a high sorption capacity for P, as high as 19,000 mg/kg. The technology was demonstrated at an active fish hatchery, where the media remained in service for over three months without stripping or regeneration. Over that period of time, the calculated P removal was 50%, even at a very low influent P concentration of 60 parts per billion. In summary, use of the AMD-derived Ferroxysorb sorption media will reduce AMD treatment costs while at the same time helping to resolve the pressing environmental issue of eutrophication and degradation of sensitive waterways.

  8. GeoChip-Based Analysis of the Functional Gene Diversity and Metabolic Potential of Microbial Communities in Acid Mine Drainage▿ †

    PubMed Central

    Xie, Jianping; He, Zhili; Liu, Xinxing; Liu, Xueduan; Van Nostrand, Joy D.; Deng, Ye; Wu, Liyou; Zhou, Jizhong; Qiu, Guanzhou

    2011-01-01

    Acid mine drainage (AMD) is an extreme environment, usually with low pH and high concentrations of metals. Although the phylogenetic diversity of AMD microbial communities has been examined extensively, little is known about their functional gene diversity and metabolic potential. In this study, a comprehensive functional gene array (GeoChip 2.0) was used to analyze the functional diversity, composition, structure, and metabolic potential of AMD microbial communities from three copper mines in China. GeoChip data indicated that these microbial communities were functionally diverse as measured by the number of genes detected, gene overlapping, unique genes, and various diversity indices. Almost all key functional gene categories targeted by GeoChip 2.0 were detected in the AMD microbial communities, including carbon fixation, carbon degradation, methane generation, nitrogen fixation, nitrification, denitrification, ammonification, nitrogen reduction, sulfur metabolism, metal resistance, and organic contaminant degradation, which suggested that the functional gene diversity was higher than was previously thought. Mantel test results indicated that AMD microbial communities are shaped largely by surrounding environmental factors (e.g., S, Mg, and Cu). Functional genes (e.g., narG and norB) and several key functional processes (e.g., methane generation, ammonification, denitrification, sulfite reduction, and organic contaminant degradation) were significantly (P < 0.10) correlated with environmental variables. This study presents an overview of functional gene diversity and the structure of AMD microbial communities and also provides insights into our understanding of metabolic potential in AMD ecosystems. PMID:21097602

  9. Disposal of fluidized bed combustion ash in an underground mine to control acid mine drainage and subsidence - phase II - small scale field demonstration. Topical report, December 1, 1996--February 28, 1997

    SciTech Connect

    Ziemkiewicz, P.F.; Head, W.J.; Gray, D.D.; Siriwardane, H.J.; Sack, W.A.

    1998-01-01

    It has been proposed that a mix made from fly and bottom ash from atmospheric pressure fluidized bed coal combusters (FBC ash), water, and stabilizers be injected from the surface into abandoned room and pillar coal mines through boreholes. Besides ash disposal, this process would prevent subsidence and acid mine drainage. Such a mix (called `grout`) needs to be an adequately stable and flowable suspension for it to spread and cover large areas in the mine. This is necessary as the drilling of the boreholes will be an expensive operation and the number such holes should be minimized. Addition of bentonite was found to be needed for this purpose. A suitable grout mix was tested rheologically to determine its fluid flow properties. Finding little published information on such materials, tests were performed using a commercial rotational viscometer with a T-bar rotor and a stand which produced a helical rotor path. Existing mixer viscometer test methods were modified and adapted to convert the measurements of torque vs. angular speed to the material properties appearing in several non-Newtonian constitutive equations. Yield stress was measured by an independent test called the vane method. The rheological behavior was a close fit to the Bingham fluid model. Bleed tests were conducted to ascertain the stability of the mixtures. Spread tests were conducted to compare the flowability of various mixes. Using the flow parameters determined in the laboratory, numerical simulations of grout flow were performed and compared with the results of scale model and field tests. A field injection of this grout was performed at the Fairfax mines in Preston county, W.V.. The observations there proved that this FBC ash grout flows as desired, is a very economical way of disposing the environmentally menacing ash, while also preventing the subsidence and acid mine drainage of the mines.

  10. Practical applications of sulfate-reducing bacteria to control acid mine drainage at the Lilly/Orphan Boy Mine near Elliston, Montana

    SciTech Connect

    Canty, M.

    1994-12-31

    The overall purpose of this document is to provide a detailed technical description of a technology, biological sulfate reduction, which is being demonstrated under the Mine Waste Technology Pilot Program, and provide the technology evaluation process undertaken to select this technology for demonstration. In addition, this document will link the use of the selected technology to an application at a specific site. The purpose of this project is to develop technical information on the ability of biological sulfate reduction to slow the process of acid generation and, thus, improve water quality at a remote mine site. Several technologies are screened for their potential to treat acid mine water and to function as a source control for a specific acid-generating situation: a mine shaft and associated underground workings flooded with acid mine water and discharging a small flow from a mine opening. The preferred technology is the use of biological sulfate reduction. Sulfate-reducing bacteria are capable of reducing sulfate to sulfide, as well as increasing the pH and alkalinity of water affected by acid generation. Soluble sulfide reacts with the soluble metals in solution to form insoluble metal sulfides. The environment needed for efficient sulfate-reducing bacteria growth decreases acid production by reducing the dissolved oxygen in water and increasing pH. A detailed technical description of the sulfate-reducing bacteria technology, based on an extensive review of the technical literature, is presented. The field demonstration of this technology to be performed at the Lilly/Orphan Boy Mine is also described. Finally, additional in situ applications of biological sulfate reduction are presented.

  11. Application of AMDS mortar as a treatment agent for arsenic in subsurface environment

    NASA Astrophysics Data System (ADS)

    Choi, J.; Lee, H.; Choi, U. K.; Yang, I. J.

    2014-12-01

    Among the treatment technologies available for As in soil and groundwater, adsorption or precipitation using acid mine drainage (AMD) sludge has become a promised technique because of high efficiency, inexpensiveness and simple to handling. The adsorbents were prepared by addition of Cement, Joomoonjin sand, fly ash, and Ca(OH)2 to air dry AMD sludge. In this work, the adsorption of As (III) and As (V) on AMDS mortar has been studied as a function of kinetic, pH, and initial arsenic concentration. Results of batch study showed that 75-90% of both As (III) and As (V) were removed at pH 7. Arsenic adsorption capacities were the highest at neutral pH condition and the adsorption equilibrium time reached in 7 days using AMDS mortar. Additionally, the adsorption kinetic process is expressed well by pseudo-second-order model. The adsorption capacities of AMDS mortar for As(III) and As(V) were found 19.04 and 30.75 mg g-1, respectively. The results of As (III) adsorption isotherms were fitted well to the Freundlich model. Moreover, As (V) adsorption isotherms were fitted well to the Langmuir model rather than Freundlich model. Based on experimental results in this study, we could conclude that AMDS mortar can be effectively used for arsenic removal agent from subsurface environment.

  12. Recrystallization and stability of Zn and Pb minerals on their migration to groundwater in soils affected by Acid Mine Drainage under CO2 rich atmospheric waters.

    PubMed

    Goienaga, N; Carrero, J A; Zuazagoitia, D; Baceta, J I; Murelaga, X; Fernández, L A; Madariaga, J M

    2015-01-01

    The extent of vertical contamination is intimately related to the soil solution and surface chemistry of the soil matrix with reference to the metal and waste matrix in question. The present research demonstrated the impact that the dissolved CO2 of the meteoric waters, which acidify the environment with pH values below 4, has in the increase of the metal mobility. Although under the given conditions the Zn remains mainly dissolved, the initial PbS and ZnS have evolved into newly formed secondary carbonates and sulphates (i.e., hydrozincite, gunningite, hydrocerussite) that can be found in the efflorescences. The chemical simulation done on the weathering of the original sulphide ores for the formation of these secondary minerals has proved the transient storage mainly of Pb. Nonetheless, many of the minerals formed inside the galleries will be easily dissolved in the next rains and release in an ionic form to the groundwater. The analytical procedure exposed has been proved to be useful not only for the characterization of AMD but also for the prediction of the mobility of metals. PMID:25180824

  13. Microbial ecology of a novel sulphur cycling consortia from AMD: implications for acid generation

    NASA Astrophysics Data System (ADS)

    Loiselle, L. M.; Norlund, K. L.; Hitchcock, A. P.; Warren, L. A.

    2009-05-01

    Recent work1 identified a novel microbial consortia consisting of two bacterial strains common to acid mine drainage (AMD) environments (autotrophic sulphur oxidizer Acidithiobacillus ferrooxidans and heterotrophic Acidiphilium spp.) in an environmental enrichment from a mine tailings lake. The two strains showed a specific spatial arrangement within an EPS macrostructure or "pod" allowing linked metabolic redox cycling of sulphur. Sulphur species characterisation of the pods using scanning transmission X-ray microscopy (STXM) indicated that autotrophic tetrathionate disproportionation by A. ferrooxidans producing colloidal elemental sulphur (S0) is coupled to heterotrophic S0 reduction by Acidiphilium spp. Geochemical modelling of the microbial sulphur reactions indicated that if they are widespread in AMD environments, then global AMD-driven CO2 liberation from mineral weathering have been overestimated by 40-90%1. Given the common co-occurrence of these two bacteria in AMD settings, the purpose of this study was to evaluate if these pods could be induced in the laboratory by pure strains and if so, whether their combined sulphur geochemistry mimicked the previous findings. Laboratory batch experiments assessed the development of pods with pure strain type cultures (A. ferrooxidans ATCC 19859 with mixotroph Acidiphilium acidophilum ATCC 738 or strict heterotroph Acp. cryptum ATCC 2158) using fluorescent in situ hybridization (FISH) imaging. The microbial sulphur geochemistry was characterized under autotrophic conditions identical to those used with the environmental AMD enrichment in which the pods were discovered. Results showed that the combined pure strain A. ferrooxidans and Acp. acidophilum form pods identical in structure to the AMD enrichment. To test the hypothesis that these pods form for mutual metabolic benefit, experiments were performed amending pure strain and AMD enrichment bacterial treatments with organic carbon and/or additional sulphur to

  14. Analysis of substrate leachate from an innovative vertical flow AMD passive treatment system

    SciTech Connect

    Mercer, M.N.; Nairn, R.W.

    1999-07-01

    Although many organic substrate-based acid mine drainage (AMD) passive treatment systems have been constructed, analyses of initial leachate components has been limited. Labile organic materials, although providing an effective substrate for important bacterial processes in AMD treatment, may leach organic compounds, nutrients and other substances into receiving waters. Decreased dissolved oxygen levels, discoloration, nutrient enrichment and subsequent eutrophication may result. In this study, organic and inorganic components of substrate leachate from an innovative vertical flow acid mine drainage (AMD) passive treatment systems were determined during initial operation. A portion (approximately 17 L/minute) of an AMD discharge from an abandoned underground mine in southeastern Oklahoma was directed to a pilot-scale treatment system. The treatment system consists of four 185 m{sup 2} in-series cells and is comprised of alternating vertical flow anaerobic compost wetlands (VFs) and surface flow aerobic settling ponds (APs). the substrate in the VFs consists of spent mushroom substrate (SMS), high CaCO{sub 3} limestone gravel, and hydrated fly ash (HFA) in a 2:1:0.1 ratio by volume. HFA is a coal combustion product and has been identified as an effective alkalinity generating material in laboratory studies. Field data (pH, temperature, dissolved oxygen, conductivity and alkalinity) and water samples for subsequent analyses were collected at the discharge, at the inflow to each cell, and at several locations in the receiving waters. Initial data indicate pH increase to 7.3, and generation of approximately 150 mg/L alkalinity as CaCO{sub 3} eq. by the second aerobic settling pond. Total organic carbon, chemical oxygen demand, color, metals, and concentrations of other significant components were measured at all sampling locations.

  15. Quantification of Tinto River Sediment Microbial Communities: Importance of Sulfate-Reducing Bacteria and Their Role in Attenuating Acid Mine Drainage

    PubMed Central

    Sánchez-Andrea, Irene; Knittel, Katrin; Amann, Rudolf; Amils, Ricardo

    2012-01-01

    Tinto River (Huelva, Spain) is a natural acidic rock drainage (ARD) environment produced by the bio-oxidation of metallic sulfides from the Iberian Pyritic Belt. This study quantified the abundance of diverse microbial populations inhabiting ARD-related sediments from two physicochemically contrasting sampling sites (SN and JL dams). Depth profiles of total cell numbers differed greatly between the two sites yet were consistent in decreasing sharply at greater depths. Although catalyzed reporter deposition fluorescence in situ hybridization with domain-specific probes showed that Bacteria (>98%) dominated over Archaea (<2%) at both sites, important differences were detected at the class and genus levels, reflecting differences in pH, redox potential, and heavy metal concentrations. At SN, where the pH and redox potential are similar to that of the water column (pH 2.5 and +400 mV), the most abundant organisms were identified as iron-reducing bacteria: Acidithiobacillus spp. and Acidiphilium spp., probably related to the higher iron solubility at low pH. At the JL dam, characterized by a banded sediment with higher pH (4.2 to 6.2), more reducing redox potential (−210 mV to 50 mV), and a lower solubility of iron, members of sulfate-reducing genera Syntrophobacter, Desulfosporosinus, and Desulfurella were dominant. The latter was quantified with a newly designed CARD-FISH probe. In layers where sulfate-reducing bacteria were abundant, pH was higher and redox potential and levels of dissolved metals and iron were lower. These results suggest that the attenuation of ARD characteristics is biologically driven by sulfate reducers and the consequent precipitation of metals and iron as sulfides. PMID:22544246

  16. Chemical and mineralogical changes of waste and tailings from the Murgul Cu deposit (Artvin, NE Turkey): implications for occurrence of acid mine drainage.

    PubMed

    Sağlam, Emine Selva; Akçay, Miğraç

    2016-04-01

    Being one of the largest copper-producing resources in Turkey, the Murgul deposit has been a source of environmental pollution for very long time. Operated through four open pits with an annual production of about 3 million tons of ore at an average grade of about 0.5% Cu, the deposit to date has produced an enormous pile of waste (exceeding 100 million tons) with tailings composed of 36 % SiO2, 39% Fe2O3 and 32% S, mainly in the form of pyrite and quartz. Waters in the vicinity of the deposit vary from high acid-acid (2.71-3.85) and high-extremely metal rich (34.48-348.12 mg/l in total) in the open pits to near neutral (6.51-7.83) and low metal (14.39-973.52 μg/l in total) in downstream environments. Despite low metal contents and near neutral pH levels of the latter, their suspended particle loads are extremely high and composed mainly of quartz and clay minerals with highly elevated levels of Fe (3.5 to 24.5% Fe2O3; 11% on average) and S (0.5 to 20.6% S; 7% on average), showing that Fe is mainly in the form of pyrite and lesser hematite. They also contain high concentrations of As, Au, Ba, Cu, Pb, and Zn. Waters collected along the course of polluted drainages are supersaturated with respect to Fe phases such as goethite, hematite, maghemite, magnetite, schwertmannite and ferrihydrite. Secondary phases such as Fe-sulphates are only found near the pits, but not along the streams due to neutral pH conditions, where pebbles are covered and cemented by Fe-oxides and hydroxides indicating that oxidation of pyrite has taken place especially at times of low water load. It follows, then, that the pyrite-rich sediment load of streams fed by the waste of the Murgul deposit is currently a big threat to the aquatic life and environment and will continue to be so even after the closure of the deposit. In fact, the oxidation will be enhanced and acidity increased due to natural conditions, which necessitates strong remedial actions to be taken. PMID:26637995

  17. Effects of iron on arsenic speciation and redox chemistry in acid mine water

    USGS Publications Warehouse

    Bednar, A.J.; Garbarino, J.R.; Ranville, J.F.; Wildeman, T.R.

    2005-01-01

    Concern about arsenic is increasing throughout the world, including areas of the United States. Elevated levels of arsenic above current drinking-water regulations in ground and surface water can be the result of purely natural phenomena, but often are due to anthropogenic activities, such as mining and agriculture. The current study correlates arsenic speciation in acid mine drainage and mining-influenced water with the important water-chemistry properties Eh, pH, and iron(III) concentration. The results show that arsenic speciation is generally in equilibrium with iron chemistry in low pH AMD, which is often not the case in other natural-water matrices. High pH mine waters and groundwater do not always hold to the redox predictions as well as low pH AMD samples. The oxidation and precipitation of oxyhydroxides deplete iron from some systems, and also affect arsenite and arsenate concentrations through sorption processes. ?? 2004 Elsevier B.V. All rights reserved.

  18. Remediation of AMD using natural and waste material

    NASA Astrophysics Data System (ADS)

    Basir, Nur Athirah Mohamad; Yaacob, Wan Zuhairi Wan

    2014-09-01

    Acid Mine Drainage (AMD) is highly acidic, sulphate rich and frequently carries a high transition metal and heavy metal burden. These AMD's eventually migrate into streams and rivers and impact negatively on the quality of these water bodies. So it is dire necessary to treat this AMD. Various materials such as ladle furnace slag (LFS), bentonite, zeolite, active carbon and kaolinite are currently available to remove heavy metals from contaminated water. All these materials are capable to rise up the pH value and adsorb heavy metals. The process is divided into two stages; screening test and tank experiment. Screening test is conduct by using Batch Equilibrium Test (BET), X-Ray Fluorescene (XRF) identification also Scanning Electron Microscopic (SEM) characteristic. The results showed that all the concentration of heavy metal are decreasing extremely and pH value rise up except for kaolinite. From screening test only ladle furnace slag, bentonite, zeolite and active carbon are chosen for the tank experiment. Tank experiment design with 18cm (H) X 15cm (L) X 15cm (H) was made by silica glass. All these treatment materials were stirred in the tank for 30 days. Initial pH for all tanks is 2.4 and after 30 days is changing into 6.11, 3.91, 2.98 and 2.71 for LFS, bentonite, active carbon as well as zeolite respectively. LFS is the best material for absorption of Zn, Mn and Cu in the synthetic solution. Meanwhile, bentonite is the best absorbent for Ni, Fe and Cd. The conclusion shows that LFS might have big potentials to control AMD pollution base on neutralize pH resulting in a great improvement in the quality of the water.

  19. Remediation of AMD using natural and waste material

    SciTech Connect

    Basir, Nur Athirah Mohamad; Yaacob, Wan Zuhairi Wan

    2014-09-03

    Acid Mine Drainage (AMD) is highly acidic, sulphate rich and frequently carries a high transition metal and heavy metal burden. These AMD's eventually migrate into streams and rivers and impact negatively on the quality of these water bodies. So it is dire necessary to treat this AMD. Various materials such as ladle furnace slag (LFS), bentonite, zeolite, active carbon and kaolinite are currently available to remove heavy metals from contaminated water. All these materials are capable to rise up the pH value and adsorb heavy metals. The process is divided into two stages; screening test and tank experiment. Screening test is conduct by using Batch Equilibrium Test (BET), X-Ray Fluorescene (XRF) identification also Scanning Electron Microscopic (SEM) characteristic. The results showed that all the concentration of heavy metal are decreasing extremely and pH value rise up except for kaolinite. From screening test only ladle furnace slag, bentonite, zeolite and active carbon are chosen for the tank experiment. Tank experiment design with 18cm (H) X 15cm (L) X 15cm (H) was made by silica glass. All these treatment materials were stirred in the tank for 30 days. Initial pH for all tanks is 2.4 and after 30 days is changing into 6.11, 3.91, 2.98 and 2.71 for LFS, bentonite, active carbon as well as zeolite respectively. LFS is the best material for absorption of Zn, Mn and Cu in the synthetic solution. Meanwhile, bentonite is the best absorbent for Ni, Fe and Cd. The conclusion shows that LFS might have big potentials to control AMD pollution base on neutralize pH resulting in a great improvement in the quality of the water.

  20. Acid mine water aeration and treatment system

    DOEpatents

    Ackman, Terry E.; Place, John M.

    1987-01-01

    An in-line system is provided for treating acid mine drainage which basically comprises the combination of a jet pump (or pumps) and a static mixer. The jet pump entrains air into the acid waste water using a Venturi effect so as to provide aeration of the waste water while further aeration is provided by the helical vanes of the static mixer. A neutralizing agent is injected into the suction chamber of the jet pump and the static mixer is formed by plural sections offset by 90 degrees.

  1. Utilization of AMD sludges from the anthracite region of Pennsylvania for removal of phosphorus from wastewater

    USGS Publications Warehouse

    Sibrell, P.L.; Cravotta, C.A., III; Lehman, W.G.; Reichert, W.

    2010-01-01

    Excess phosphorus (P) inputs from human sewage, animal feeding operations, and nonpoint source discharges to the environment have resulted in the eutrophication of sensitive receiving bodies of water such as the Great Lakes and Chesapeake Bay. Phosphorus loads in wastewater discharged from such sources can be decreased by conventional treatment with iron and aluminum salts but these chemical reagents are expensive or impractical for many applications. Acid mine drainage (AMD) sludges are an inexpensive source of iron and aluminum hydrous oxides that could offer an attractive alternative to chemical reagent dosing for the removal of P from local wastewater. Previous investigations have focused on AMD sludges generated in the bituminous coal region of western Pennsylvania, and confirmed that some of those sludges are good sorbents for P over a wide range of operating conditions. In this study, we sampled sludges produced by AMD treatment at six different sites in the anthracite region of Pennsylvania for potential use as P sequestration sorbents. Sludge samples were dried, characterized, and then tested for P removal from water. In addition, the concentrations of acid-extractable metals and other impurities were investigated. Test results revealed that sludges from four of the sites showed good P sorption and were unlikely to add contaminants to treated water. These results indicate that AMD sludges could be beneficially used to sequester P from the environment, while at the same time decreasing the expense of sludge disposal.

  2. Soil stabilisation using AMD sludge, compost and lignite: TCLP leachability and continuous acid leaching.

    PubMed

    Tsang, Daniel C W; Olds, William E; Weber, Paul A; Yip, Alex C K

    2013-11-01

    Utilising locally available industrial by-products for in situ metal stabilisation presents a low-cost remediation approach for contaminated soil. This study explored the potential use of inorganic (acid mine drainage (AMD) sludge and zero-valent iron) and carbonaceous materials (green waste compost, manure compost, and lignite) for minimising the environmental risks of As and Cu at a timber treatment site. After 9-month soil incubation, significant sequestration of As and Cu in soil solution was accomplished by AMD sludge, on which adsorption and co-precipitation could take place. The efficacy of AMD sludge was comparable to that of zero-valent iron. There was marginal benefit of adding carbonaceous materials. However, in a moderately aggressive environment (Toxicity Characteristic Leaching Procedure), AMD sludge only suppressed the leachability of As but not Cu. Therefore, the provision of compost and lignite augmented the simultaneous reduction of Cu leachability, probably via surface complexation with oxygen-containing functional groups. Under continuous acid leaching in column experiments, combined application of AMD sludge with compost proved more effective than AMD sludge with lignite. This was possibly attributed to the larger amount of dissolved organic matter with aromatic moieties from lignite, which may enhance Cu and As mobility. Nevertheless, care should be taken to mitigate ecological impact associated with short-term substantial Ca release and continuous release of Al at a moderate level under acid leaching. This study also articulated the engineering implications and provided recommendations for field deployment, material processing, and assessment framework to ensure an environmentally sound application of reactive materials. PMID:24144464

  3. Definition of redox and pH influence in the AMD mine system using a fuzzy qualitative tool (Iberian Pyrite Belt, SW Spain).

    PubMed

    de la Torre, M L; Grande, J A; Valente, T; Perez-Ostalé, E; Santisteban, M; Aroba, J; Ramos, I

    2016-03-01

    Poderosa Mine is an abandoned pyrite mine, located in the Iberian Pyrite Belt which pours its acid mine drainage (AMD) waters into the Odiel river (South-West Spain). This work focuses on establishing possible reasons for interdependence between the potential redox and pH, with the load of metals and sulfates, as well as a set of variables that define the physical chemistry of the water-conductivity, temperature, TDS, and dissolved oxygen-transported by a channel from Poderosa mine affected by acid mine drainage, through the use of techniques of artificial intelligence: fuzzy logic and data mining. The sampling campaign was carried out in May of 2012. There were a total of 16 sites, the first inside the tunnel and the last at the mouth of the river Odiel, with a distance of approximately 10 m between each pair of measuring stations. While the tools of classical statistics, which are widely used in this context, prove useful for defining proximity ratios between variables based on Pearson's correlations, in addition to making it easier to handle large volumes of data and producing easier-to-understand graphs, the use of fuzzy logic tools and data mining results in better definition of the variations produced by external stimuli on the set of variables. This tool is adaptable and can be extrapolated to any system polluted by acid mine drainage using simple, intuitive reasoning. PMID:26566614

  4. Investigation into the use of cement kiln dust in high density sludge (HDS) treatment of acid mine water.

    PubMed

    Mackie, Allison L; Walsh, Margaret E

    2015-11-15

    The purpose of this study was to investigate the potential to replace lime with cement kiln dust (CKD) in high density sludge (HDS) treatment of acid mine drainage (AMD). The bench-scale study used two water samples: AMD sampled from a lead-zinc mine with high concentrations of iron (Fe), zinc (Zn), and arsenic (As) (Fe/Zn-AMD) and a synthetic AMD solution (Syn-AMD) spiked with ferric sulfate (Fe2(SO4)3). Arsenic was found to be significantly reduced with CKD-HDS treatment of Fe/Zn-AMD compared to lime-HDS treatment, to concentrations below the stringent mine effluent discharge regulation of 0.10 mg As/L (i.e., 0.04 ± 0.02 mg/L). Both CKD- and lime-HDS treatment of the two AMD samples resulted in settled water Fe concentrations above the stringent discharge guideline of 0.3 mg Fe/L. CKD addition in the HDS process also resulted in high settled water turbidity, above typical discharge guidelines of 15 mg TSS/L. CKD-HDS treatment was found to result in significantly improved settled solids (i.e., sludge) quality compared to that generated in the lime-HDS process. HDS treatment with CKD resulted in 25-88% lower sludge volume indices, 2 to 9 times higher % wet solids, and 10 to 20 times higher % dry solids compared to lime addition. XRD and XPS testing indicated that CKD-HDS sludge consisted of mainly CaCO3 and SiO2 with Fe(3+) precipitates attached at particle surfaces. XRD and XPS testing of the lime-HDS generated sludge showed that it consisted of non-crystalline Fe oxides typical of sludge formed from precipitates with a high water concentration. Increased sedimentation rates were also found for CKD (1.3 cm/s) compared to lime (0.3 cm/s). The increased solids loading with CKD addition compared to lime addition in the HDS process was suggested to both promote surface complexation of metal precipitates with insoluble CKD particles and increase compression effects during Type IV sedimentation. These mechanisms collectively contributed to the reduced water content of

  5. Precipitation, pH and metal load in AMD river basins: an application of fuzzy clustering algorithms to the process characterization.

    PubMed

    Grande, J A; Andújar, J M; Aroba, J; de la Torre, M L; Beltrán, R

    2005-04-01

    In the present work, Acid Mine Drainage (AMD) processes in the Chorrito Stream, which flows into the Cobica River (Iberian Pyrite Belt, Southwest Spain) are characterized by means of clustering techniques based on fuzzy logic. Also, pH behavior in contrast to precipitation is clearly explained, proving that the influence of rainfall inputs on the acidity and, as a result, on the metal load of a riverbed undergoing AMD processes highly depends on the moment when it occurs. In general, the riverbed dynamic behavior is the response to the sum of instant stimuli produced by isolated rainfall, the seasonal memory depending on the moment of the target hydrological year and, finally, the own inertia of the river basin, as a result of an accumulation process caused by age-long mining activity. PMID:15798799

  6. Prediction of AMD generation potential in mining waste piles, in the Sarcheshmeh porphyry copper deposit, Iran.

    PubMed

    Modabberi, Soroush; Alizadegan, Ali; Mirnejad, Hassan; Esmaeilzadeh, Esmat

    2013-11-01

    This study investigates the possibility of acid mine drainage (AMD) generation in active and derelict mine waste piles in Sarcheshmeh Copper Mine produced in several decades, using static tests including acid-base accounting (ABA) and net acid-generating pH (NAGpH). In this study, 51 composite samples were taken from 11 waste heaps, and static ABA and NAGpH tests were carried out on samples. While some piles are acid producing at present and AMD is discharging from the piles, most of them do not show any indication on their AMD potential, and they were investigated to define their acid-producing potential. The analysis of data indicates that eight waste piles are potentially acid generating with net neutralization potentials (NNPs) of -56.18 to -199.3, net acid generating of 2.19-3.31, and NPRs from 0.18 to 0.44. Other waste piles exhibited either a very low sulfur, high carbonate content or excess carbonate over sulfur; hence, they are not capable of acid production or they can be considered as weak acid producers. Consistency between results of ABA and NAGpH tests using a variety of classification criteria validates these tests as powerful means for preliminary evaluation of AMD/ARD possibilities in any mining district. It is also concluded that some of the piles with very negative NNPs are capable to produce AMD naturally, and they can be used in heap leaching process for economic recovery of trace amounts of metals without applying any biostimulation methods. PMID:23813094

  7. Biogeochemistry on the Interrelation between AMD and Sediments under Seasonal Variations

    NASA Astrophysics Data System (ADS)

    Cho, K. H.; Kim, B. J.; Wi, D. W.; Choi, N. C.; Park, C. Y.

    2012-04-01

    The objective of this study was to investigate the influence of the seasonal characteristic variations on heavy metals through geochemical property on the interrelation between acid mine drainage (AMD) and sediments in the abandoned Hwa-sun coal mine, Korea. We conducted to confirm the chemical and mineralogical property (XRD, SEM-EDS and IR) using AMD and sediments samples (per month). As high concentrations in AMD and sediments were showed a large variability from 168.12 to 2,500.12 mg/L and 5.25 ~179g/kg, respectively. Also Fe contents measured from 20.46 to 280.63 mg/L in AMD and 13.72 ~56.84 weight percents in sediments. Compared to effective precipitation, As and Fe content in AMD and sediments was appeared dry season was higher than rainy season. In XRD analyses of the sediments, x-ray diffracted d-value belong to Quartz, Ca-minerals (aragonite and calcite) and Fe-mineral (lepidocrocite) was observed. In the IR analysis, the OH-stretching vibration, the gamma-OH bending vibration and the delta-OH-bending vibration of diagnostic absorption bands for iron hydroxide were well found in the yellow-colored iron hydroxide. The results of SEM-EDS analysis revealed that Sheathed-filament and twist-stalk structures were observed in the amorphous iron-hydroxide. It is suggested that this is a microorganism that produces the iron-hydroxide. The EDS analysis detected Fe and As ions on the iron-hydroxide which were attached to the sheathed-filament and the twisted-stalk were detected.

  8. Localized effects of coal mine drainage on fish assemblages in a Cumberland Plateau stream in Tennessee

    SciTech Connect

    Schorr, M.S.; Backer, J.C.

    2006-03-15

    The upper watershed of North Chickamauga Creek (NCC), a fourth-order tributary to the Tennessee River, Tennessee, has been impacted by decades of acid mine drainage (AMD) from abandoned coal mines. We assessed fish assemblages, pH, conductivity, and sediment coverage at 12 study reaches (six AMD sites and six reference sites) in the Cumberland Plateau region of the NCC system, May-September 1998. Stream pH increased (3.6 to 6.0) and conductivity decreased (296 to 49 {mu}S/cm) downstream of the AMD-impacted area; however, no discernable gradient was observed in sediment cover. Elevated conductivity at AMD-impacted sites reflected increased concentrations of dissolved metals and other inorganic ions. Reference sites exhibited higher pH (6.0-6.4) and lower conductivity (13-28 {mu}S/cm). Acidified reaches were characterized by low fish species richness and abundance; no fish were observed at sites where the mean pH was {lt} 5. Centrarchids (mostly bluegill (Lepomis macrochirus) and green sunfish (L. cyanellus)) comprised {gt} 90 % of the catch at AMD sites, whereas cypriniids (creek chub (Semotilus atromaculatus) and blacknose dace (Rhinichthys atratulus)) accounted for {gt} 90 % of the catch at reference sites. Findings from this study document the negative effects of acid drainage from coal mines on fish assemblages in a Cumberland Plateau stream.

  9. Acid neutralization within limestone sand reactors receiving coal mine drainage

    USGS Publications Warehouse

    Watten, B.J.; Sibrell, P.L.; Schwartz, M.F.

    2005-01-01

    Pulsed bed treatment of acid mine drainage (AMD) uses CO2 to accelerate limestone dissolution and intermittent fluidization to abrade and carry away metal hydrolysis products. Tests conducted with a prototype of 60 L/min capacity showed effective removal of H+ acidity over the range 196-584 mg/L (CaCO3) while concurrently generating surplus acid neutralization capacity. Effluent alkalinity (mg/L CaCO3) rose with increases in CO2 (DC, mg/L) according to the model Alkalinity = 31.22 + 2.97(DC)0.5, where DC was varied from 11-726 mg/L. Altering fluidization and contraction periods from 30 s/30 s to 10 s/50 s did not influence alkalinity but did increase energy dissipation and bed expansion ratios. Field trials with three AMD sources demonstrated the process is capable of raising AMD pH above that required for hydrolysis and precipitation of Fe3+ and Al3+ but not Fe2+ and Mn2+. Numerical modeling showed CO2 requirements are reduced as AMD acidity increases and when DC is recycled from system effluent. ?? 2005 Elsevier Ltd. All rights reserved.

  10. Characterization of Fe(II) oxidizing bacterial activities and communities at two acidic Appalachian coalmine drainage-impacted sites

    SciTech Connect

    Senko, John M.; Wanjugi, Pauline; Lucas, Melanie; Bruns, Mary Ann; Burgos, William D.

    2008-06-12

    We characterized the microbiologically mediated oxidative precipitation of Fe(II) from coalminederived acidic mine drainage (AMD) along flow-paths at two sites in northern Pennsylvania. At the Gum Boot site, dissolved Fe(II) was efficiently removed from AMD whereas minimal Fe(II) removal occurred at the Fridays-2 site. Neither site received human intervention to treat the AMD. Culturable Fe(II) oxidizing bacteria were most abundant at sampling locations along the AMD flow path corresponding to greatest Fe(II) removal and where overlying water contained abundant dissolved O2. Rates of Fe(II) oxidation determined in laboratory-based sediment incubations were also greatest at these sampling locations. Ribosomal RNA intergenic spacer analysis and sequencing of partial 16S rRNA genes recovered from sediment bacterial communities revealed similarities among populations at points receiving regular inputs of Fe(II)-rich AMD and provided evidence for the presence of bacterial lineages capable of Fe(II) oxidation. A notable difference between bacterial communities at the two sites was the abundance of Chloroflexi-affiliated 16S rRNA gene sequences in clone libraries derived from the Gum Boot sediments. Our results suggest that inexpensive and reliable AMD treatment strategies can be implemented by mimicking the conditions present at the Gum Boot field site.

  11. Solubility of Fe(III) and Al in AMD by modelling and experimtn

    SciTech Connect

    Mitchell, K.G.; Wildeman, T.R.

    1995-12-01

    Studies of Fe(III) and Al species in acid mine drainage (AMD) alone and in contact with limestone were conducted by MINTEQA2 and by experiments. Using Fe(OH){sub 3} as the primary species and the standard values for MINTEQ, Fe(III) precipitates at pH 2.90 when the concentration is 453 mg/L. Al precipitates at a pH of 4.00 when the concentration is 108 mg/L. Experiments found that over 90 % of Fe(III) and 45 % of Al were precipitated at these pH`s. Experimental verification of Fe(III) concentrations at pH`s from 2.90 to 4.0 found that modelling agreed with experiment when ferrihydrite is the primary solid and the log Ksp is -38.9. For Al, gibbsite would be the primary solid and log Ksp is -34.1. For AMD in contact with CaCO{sub 3} when CO{sub 2} is conserved, final alkalinity is higher when mineral acidity is higher even though pH of the final solution is lower. This modelling result was confirmed by experiment. Higher mineral acidity causes generation of more CO{sub 2} that reacts with CaCO{sub 3} to generate more dissolved HCO{sub 3-}.

  12. Solubility of Fe(III) Al in AMD by modelling and experiment

    SciTech Connect

    Mitchell, K.G.; Wildeman, T.R.

    1996-12-31

    Studies of Fe(III) and Al species in acid mine drainage (AMD) alone and in contact with limestone were conducted by MINTEQA2 modelling and by experiments. The objectives of these studies were to: (1) determine at what pH Fe(III) and Al would be in solution in AMD such that the water would be harmful to an anoxic limestone drain (ALD), and (2) evaluate the theoretical limits to the amount of alkalinity that could be generated by an ALD. Using Fe(OH){sub 3} as the primary species and the standard values for MINTEQA2, Fe(III) precipitates at pH 2.90 when the concentration is over 453 mg/L. Al precipitates at a pH of 4.00 when the concentration is over 108 mg/L. Experiments found that over 90 % of Fe(III) and 45% of Al were precipitated at these pH`s. Experimental verification of Fe(III) concentrations of pH`s from 2.90 to 4.0 found that modelling agreed with experiment when ferrihydrite is the primary solid and the log Ksp (solubility product) is -38.9. For Al, gibbsite would be the primary solid and log Ksp is -34.1. For AMD in contact with CaCO{sub 3} when CO{sub 2} is conserved, final alkalinity is higher when mineral acidity is higher even though pH of the final solution is lower. This modelling result was confirmed by experiment. Higher mineral acidity causes generation of more CO{sub 2} that reacts with CaCO{sub 3} to generate more dissolved HCO{sub -3}.

  13. PRIORITY POLLUTANT REMOVAL FROM MINE DRAINAGE

    EPA Science Inventory

    A study of the removal of selected priority pollutants from acid mine drainage was conducted at EPA's Crown, West Virginia, site. The pollutants studied were the volatiles benzene, chloroform, methylene chloride, tetrachloroethene, toluene, trans-dichloroethene; the semivolatiles...

  14. Arsenic in an Alkaline AMD Treatment Sludge: Characterization and Stability Under Prolonged Anoxic Conditions

    SciTech Connect

    Beauchemin, S.; Fiset, J; Poirier, G; Ablett, J

    2010-01-01

    Lime treatment of acid mine drainage (AMD) generates large volumes of neutralization sludge that are often stored under water covers. The sludge consists mainly of calcite, gypsum and a widespread ferrihydrite-like Fe phase with several associated species of metal(loid) contaminants. The long-term stability of metal(loid)s in this chemically ill-defined material remains unknown. In this study, the stability and speciation of As in AMD sludge subjected to prolonged anoxic conditions is determined. The total As concentration in the sludge is 300 mg kg{sup -1}. In the laboratory, three distinct water cover treatments were imposed on the sludge to induce different redox conditions (100%N{sub 2}, 100%N{sub 2} + glucose, 95%N{sub 2}:5%H{sub 2}). These treatments were compared against a control of oxidized, water-saturated sludge. Electron micro-probe (EMP) analysis and spatially resolved synchrotron X-ray fluorescence (SXRF) results indicate that As is dominantly associated with Fe in the sludge. In all treatments and throughout the experiment, measured concentrations of dissolved As were less than 5 {micro}g L{sup -1}. Dissolved Mn concentration in the N{sub 2} + glucose treatment increased significantly compared to other treatments. Manganese and As K-edge X-ray absorption near edge structure spectroscopy (XANES) analyses showed that Mn was the redox-active element in the solid-phase, while As was stable. Arsenic(V) was still the dominant species in all water-covered sludges after 9 months of anoxic treatments. In contrast, Mn(IV) in the original sludge was partially reduced into Mn(II) in all water-covered sludges. The effect was most pronounced in the N{sub 2} + glucose treatment, suggesting microbial reduction. Micro-scale SXRF and XANES analysis of the treated sludge showed that Mn(II) accumulated in areas already enriched in Fe and As. Overall, the study shows that AMD sludges remain stable under prolonged anoxic conditions. External sources of chemical reductants

  15. Treated mine drainage effluent benefits Maryland and West Virginia fisherman

    SciTech Connect

    Ashby, J.C.

    1995-12-31

    In January of 1994, the Maryland Department of Natural Resources-Freshwater Fisheries Division and Mettiki Coal Corporation of Oakland, Maryland entered into a cooperative agreement to construct a trout rearing facility within Mettiki`s 10 million gallons per day acid mine drainage treatment system to supplement the DNR stockings in the newly revitalized North Branch of the Potomac River. Due to pyrite oxidation and a lack of alkaline buffering capacity in the Freeport coal strata, seven thousand gallons per minute of acidic water containing oxidized sulfide minerals must be pumped through Mettiki`s AMD treatment systems and elevated to Federal standards prior to discharge into the Upper North Branch of the Potomac River. Utilizing hydrated lime, aeration, flocculation, sedimentation, and sludge recirculation, Mettiki`s treatment imparts superior trout propagation qualities to the discharge (pH of 8.1, dissolved oxygen of 8.0 ppm, temperature ranges of from 52 to 60 degrees Fahrenheit) and has allowed for weight gain throughout the typically dormant winter months. Presently, 30,000 brown, rainbow, and cutthroat trout are suspended in floating net pens within the systems` discharge collection pond where pH, flow, temperature, feed assimilation, and growth rates were compared with typical stream diversion hatcheries. Growth rates, lack of significant disease, and quality parameters coupled with ideal temperatures suggests treated acidic mine effluent can offer successful fish propagation opportunities.

  16. Cu(II) incorporation to schwertmannite: Effect on stability and reactivity under AMD conditions

    NASA Astrophysics Data System (ADS)

    Antelo, Juan; Fiol, Sarah; Gondar, Dora; Pérez, Claudio; López, Rocío; Arce, Florencio

    2013-10-01

    The formation, transformation and surface chemistry of iron oxides is geologically important in surface waters polluted by acid mine drainage (AMD). The geochemical behaviour of these oxides controls the availability and mobility of contaminants in such highly polluted systems. The low pH values, together with the presence of large amounts of sulphate, favour the formation of schwertmannite, which is a metastable iron oxide that is transformed to goethite under oxic conditions. However, in copper mining environments, co-precipitation of iron and copper ions is expected and therefore the surface chemistry of the iron oxides present in these systems may be different. Several schwertmannite samples were prepared in the presence of high concentrations of sulphate and different concentrations of copper to simulate copper-rich mining environments. Long-term transformation experiments were conducted to study the mineral oxide stability and variations in surface chemistry produced over a period of 15 months. Schwertmannite-like particles were initially formed, but sulphate release and the dissolution and re-precipitation of iron and copper ions occurred under more acidic conditions throughout the experiment, which led to the formation of goethite-like particles. The capacity for arsenate adsorption was highest in the initial schwertmannite-like particles, and arsenate mobility increased in the presence of more stable iron mineral phases that were formed throughout the transformation experiment.

  17. Column leaching test to evaluate the use of alkaline industrial wastes to neutralize acid mine tailings

    SciTech Connect

    Doye, I.; Duchesne, J.

    2005-08-01

    Acid mine drainage is a serious environmental problem caused by the oxidation of sulfide minerals that releases highly acidic, sulfate, and metals-rich drainage. In this study, alkaline industrial wastes were mixed with acid mine tailings in order to obtain neutral conditions. A series of column leaching tests were performed to evaluate the behavior of reactive mine tailings amended with alkaline-additions under dynamic conditions. Column tests were conducted of oxidized mine tailings combined with cement kiln dust, red mud bauxite, and mixtures of cement kiln dust with red mud bauxite. The pH results show the addition of 10% of alkaline materials permits the maintenance of near neutral conditions. In the presence of 10% alkaline material, the concentration of toxic metals such as Al, Cu, Fe, Zn are significantly reduced as well as the number of viable cells (Thiobacillus ferrooxidans) compared to control samples.

  18. Proceedings, joint conference of the 21st annual meeting of the American Society of Mining and Reclamation and 25th West Virginia Surface Mine Drainage Task Force symposium

    SciTech Connect

    Barnhisel, R.I.

    2004-07-01

    Topics covered include: underground mine hydrology; valley fills; acid drainage technology initiative; reforestation/forestry; passive treatment of acid mine drainage; hydrology; selenium; acid mine drainage and remining; overburden/soils; forestry in West Virginia; revegetation and wildlife; mine soils; tailings; stream restoration; chemical treatment of acid mine drainage; watershed restoration; acidity; aquaculture; and stream characterisation. The poster papers and plenary session papers are also included.

  19. LIMESTONE-LIME TREATMENT OF ACID MINE DRAINAGE - FULL SCALE

    EPA Science Inventory

    The nation-wide problems related to acidic discharges from coal mining operations are well documented in both popular and technical literature. Neutralization is and will continue to be a necessary short-term measure in numerous instances, while long-range programs are being deve...

  20. Inorganic Nitrogen Cycling in an Extreme Acid Mine Drainage Site

    NASA Astrophysics Data System (ADS)

    Kalnejais, L. H.; Smith, R. L.; Nordstrom, D. K.; Banfield, J. F.

    2006-12-01

    Weathering of the massive sulfide ore body at Iron Mountain, northern California has generated sulfuric acid solutions with pH values ranging from 0.5 to 1, temperatures up to 50°C and high concentrations of toxic metals. Communities of microorganisms catalyze the oxidation of iron and sulfur that generates this extreme environment. The nitrogen requirements of these organisms and the nitrogen cycling within these waters are not understood. By adapting the chemiluminescence detection method of Baeseman (2004) we have constrained the stability of nitrate and nitrite species in acidic, high ferrous iron solutions and have measured a time series of the nitrate concentrations at sites within Iron Mountain. The half-life of nitrite is less than an hour due to reactions with ferrous ions, while nitrate is found at concentrations of up to 10 μM within the mine. By coupling this information with geochemical and microbial community information at each site together with culture enrichment studies using various nitrogen sources we hope to gain insight into the pathways of nitrogen utilization in this extreme environment. References Baeseman, J.L. (2004) Denitrification in acid-impacted mountain stream sediments. Ph.D. Dissertation, University of Colorado, Department of Civil, Environmental, and Architectural Engineering.

  1. PHYSICAL SOLUTIONS FOR ACID MINE DRAINAGE AT REMOTE MINE SITES

    EPA Science Inventory

    After completing extensive bench-scale testing to determine optimum treatment approaches, the technology has been taken to the field. Preliminary results show that calcium hydroxide precipitates the bulk of the arsenic and zinc; the granular ferric hydroxide removes the rest of ...

  2. ROTATING DISC BIOLOGICAL TREATMENT OF ACID MINE DRAINAGE

    EPA Science Inventory

    Pilot scale (0.5-m diameter) and prototype (2.0-m diameter) rotating biological contactors (RBC) were investigated for oxidation of ferrous Fe(II) iron contained in six heterogeneous mine waters located at three coal mining sites in Pennsylvania and West Virginia. Continuous biol...

  3. Acid mine drainage: An economic total resource recovery solution

    SciTech Connect

    Clarke, R.L.; Clarke, S.R.; Brackenbury, D.R.

    1995-12-31

    A common feature of abandoned hard rock mines and subterranean coal mines is the creation of toxic and acidic solution often containing iron, copper, zinc, lead, cadmium, manganese and alkaline earth and alkali metals. A process is described which sequentially removes heavy metals using electrochemical ion exchange and rotating cylinder electrodes. Studies summarized indicate recovery of copper, zinc, iron, and aluminum oxide; selective stripping of arsenic, cadmium, chromium, and lead; and recovery of water acceptable for drinking after removal of heavy metals.

  4. Field application of selective precipitation for recovering Cu and Zn in drainage discharged from an operating mine.

    PubMed

    Oh, Chamteut; Han, Young-Soo; Park, Jin Hee; Bok, Songmin; Cheong, Youngwook; Yim, Giljae; Ji, Sangwoo

    2016-07-01

    Acid mine drainage (AMD) generated from mining activities has been recognized as a serious problem due to its increased acidity and high concentration of heavy metals. In this research, a feasibility test of the selective precipitation (SP) process was performed using AMD discharged from a currently operating mine in Korea for the purpose of minimizing the environmental impact of AMD. For the SP process, a pilot scale equipment (100L reaction tank) was used in field and among various metals, Cu and Zn were the target metals. Through the research, it was confirmed that AMD from an operating mine has two disadvantages of being applied to the SP: altering water quality and unexpected inclusion of clay debris. Despite unfavorable conditions, Cu and Zn precipitate of 80% purity with 90% precipitation rate was able to be obtained from 1.4L/min (2.0tons/day) AMD. The recovered precipitates were identified as amorphous CuS and ZnS with small amounts of impurities (Si minerals, CuFeS2, and Fe/Al hydroxide). The strategies to reduce these impurities were also discussed. Recovery rate, which is the amount of precipitate collected per unit volume of AMD, was proposed as an indicator to evaluate the working efficiency of the SP process. It was confirmed that the recovery rate was strongly dependent on flow rate and dose of coagulant. The results of this study may be helpful in reducing the potential complications which occurs when SP is applied on field. PMID:26994808

  5. Signatures of Autotrophic and Heterotrophic Metabolic Activity in Enrichment Cultures from a Sulphur Oxidizing Acid Mine Site

    NASA Astrophysics Data System (ADS)

    Slater, G. F.; Bernier, L.; Cowie, B. R.; Warren, L. A.

    2006-12-01

    Delineating the role of microorganisms in geochemical processes of interest in natural environments requires the development of tools that provide the ability to distinguish amongst microbial activity associated with different metabolic guilds. The gap between phylogenetic characterization and phenotypic understanding remains, underscoring the need to consider alternative methods. Compound specific analysis of cellular components has the potential to differentiate between active metabolic processes supporting microbial communities and may be especially useful in extreme environments. The goal of this study was to determine whether the phospholipids fatty acid (PLFA) distribution and isotopic signatures associated with autotrophs and heterotrophs enriched from an acid mine drainage (AMD) system differed, and further whether natural consortial autotrophic isolates showed similar signatures to autotrophic pure strains of Acidithiobacillus ferrooxidans and A. thiooxidans. Two distinct initial enrichments with tetrathionate and CO2 yielded primarily autotrophic (95%) Acidithiobaccillus spp. sulphur oxidizing communities. The remaining microbial members of theses enrichments (<5%) were morphologically distinct and heterotrophic, as subculture of the consortial isolates in a medium amended with glucose but without tetrathionate selectively resulted in their visible growth. PLFA profiles and δ13C signatures from autotrophic (1) natural enrichments, pure cultures of (2) A. ferrooxidans and (3) A. thiooxidans were similar, but collectively differed from those of the natural heterotrophic enrichment cultures. The PLFA profiles for the heterotrophic communities were made up of primarily (88-99%) C16:0 and two isomers of C18:1. In contrast, the autotrophic communities had high proportions of C16:1 (up to 18%) as well as cyclo C17 and cyclo C19 PLFA that combined comprised 18 to 58% of the observed PLFA. The δ13C signatures of the PLFA also differed strongly between the two

  6. Microbial community analysis of two field-scale sulfate-reducing bioreactors treating mine drainage.

    PubMed

    Hiibel, Sage R; Pereyra, Luciana P; Inman, Laura Y; Tischer, April; Reisman, David J; Reardon, Kenneth F; Pruden, Amy

    2008-08-01

    The microbial communities of two field-scale pilot sulfate-reducing bioreactors treating acid mine drainage (AMD), Luttrell and Peerless Jenny King (PJK), were compared using biomolecular tools and multivariate statistical analyses. The two bioreactors were well suited for this study because their geographic locations and substrate compositions were similar while the characteristics of influent AMD, configuration and degree of exposure to oxygen were distinct. The two bioreactor communities were found to be functionally similar, including cellulose degraders, fermenters and sulfate-reducing bacteria (SRB). Significant differences were found between the two bioreactors in phylogenetic comparisons of cloned 16S rRNA genes and adenosine 5'-phosphosulfate reductase (apsA) genes. The apsA gene clones from the Luttrell bioreactor were dominated by uncultured SRB most closely related to Desulfovibrio spp., while those of the PJK bioreactor were dominated by Thiobacillus spp. The fraction of the SRB genus Desulfovibrio was also higher at Luttrell than at PJK as determined by quantitative real-time polymerase chain reaction analysis. Oxygen exposure at PJK is hypothesized to be the primary cause of these differences. This study is the first rigorous phylogenetic investigation of field-scale bioreactors treating AMD and the first reported application of multivariate statistical analysis of remediation system microbial communities applying UniFrac software. PMID:18430021

  7. AMD and micronutrient antioxidants.

    PubMed

    Hogg, Ruth; Chakravarthy, Usha

    2004-12-01

    Age-related maculopathy (ARM) is a common clinical entity. The late-stage manifestations of ARM, which are known as age-related macular degeneration (AMD), have devastating consequences for vision. Various risk factors have been identified in the development of the condition, which are consistent with the premise that oxidative stress plays an important role in its pathogenesis. Thus, the possibility that antioxidant balance can be manipulated through diet or supplementation has created much interest. Associations between diet and nutrition and the clinical features of ARM have been described. Scrutiny of the literature shows consistency in the report of notable reductions in serum micronutrients in wet AMD, however, the evidence for causation is still circumstantial. In this comprehensive review of the clinical literature, we have assessed the evidence for a link between diet and nutrition as risk factors for the development of ARM and AMD. All published case control, population-based, and interventional studies on ARM were examined. Although initial support appeared to be moderate and somewhat contradictory, the evidence that lifetime oxidative stress plays an important role in the development of ARM is now compelling. The positive outcomes in the Age-Related Eye Diseases Study, a major controlled clinical trial, have given hope that modulation of the antioxidant balance through supplementation can help prevent progression of ARM to AMD. PMID:15764083

  8. Physical and chemical limnological study of an acid mine lake in Sullivan County, Indiana

    SciTech Connect

    Broomall, P.A.

    1992-01-01

    Southwestern Indiana has numerous lakes developed in abandoned coal mine spoils which support recreational sports fisheries. Some lakes, due to exposure to acid mine drainage from coal wastes and pyritic spoils, are unsuitable habitats for fisheries development. This study examines a publicly owned acid mine lake with an area of approximately 51 ha, following reclamation and elimination of acid producing areas in its drainage basin. Fifteen physico-chemical sample collections were made over a thirteen month period (1991--1992). Parameters sampled included pH, total acidity, iron, manganese, and aluminum. Comparisons were made to historic pre-reclamation water quality data and to established models of acid mine lake recovery. Due to the local topography and exposure to prevailing winds, the lake was generally well mixed throughout the study. Virtually no summer stratification was found, but typical winter season stratification occurred. The water column was well oxygenated throughout the study. Secchi disk transparency varied from 2.5 m to clear to lake bottom (6 m). This study found no significant change in lake water pH (2.9--3.0 to 3.0--3.2 s.u.) since reclamation activities in 1988. However, changes in total acidity and total metal concentrations had occurred since reclamation which suggested that the lake was in early recovery stages. No trends in water quality improvement were determined which could assist in planning toward the eventual establishment of a sports fishery.

  9. Destabilization dynamics of clay and acid-free polymers of ferric and magnesium salts in AMD without pH adjustment.

    PubMed

    Ntwampe, I O; Waanders, F B; Bunt, J R

    2016-01-01

    The physicochemical treatment was employed to treat acid mine drainage (AMD) in the removal of turbid materials using clay only (exp A) and a combination of clay, FeCl3 and Mg(OH)2 (exp B) to form a polymer. A 5 g sample of clay (bentonite) was added to 1.2 L of AMD and treated in a jar test at 250 rpm for 2 min and reduced to 100 rpm for 10 min. A 200 mL sub-sample from the 1.2 L mother liquor was poured into five 500 mL glass beakers, and 20 mL dosages of a polymer of 0.1 M Fe(3+) in (FeCl3) and 0.1 M Mg(2+) in (Mg(OH)2) was added to the beakers. The samples were allowed to settle for 1 h, after which the supernatant was analyzed for pH, total suspended solids (TSS), dissolved oxygen (DO) and oxidation-reduction potential (ORP) (exp A). A similar set of experiments was conducted where 200 mL of the AMD sample was poured into 500 mL glass beakers and (20-60 mL) dosages of a combination of 5 g clay, 0.1 M Fe(3+) (FeCl3) and Mg(2+) (Mg(OH)2) polymer was added and similar mixing, settling time and measurements were conducted (exp B). The polymers used in exp A exhibited TSS removal efficiency (E%) which was slightly lower compared with the polymer used in exp B, above 90%. Clay has a high TSS removal efficiency in the treatment of the AMD, indicating that adsorption was a predominant process in exps A and B. The scanning electron microscope (SEM) micrographs of the AMD sludge of both exps A and B, with a rigid and compacted structure consisting of dense flocs surrounded by the smaller flocs bound together, corroborate the fact that adsorption is a predominant process. PMID:27533861

  10. Respiration of aquatic insect larvae (ephemeroptera, plecoptera) in acid mine water

    SciTech Connect

    Doherty, F.G.; Hummon, W.D.

    1980-09-01

    Ecotoxicology (Truhaut 1975) is the study of the harmful effects of natural substances and artificial pollutants experienced by organisms in the environment. The degree of response exhibited by an organism toward the presence of noxious substances can often be determined by monitoring a physiological parameter. One such parameter is respiration. The majority of studies dealing with the biological impact of acid mine drainage have been ecological surveys. No studies have been reported which deal with the physiological response of an organism to acid mine water other than acute toxicities of the various components expected in an effluent stream (Bell and Nebeker 1969; Kimmel and Hales 1973; Warnick and Bell 1969). These studies did not consider possible synergistic effects between individual components of acid mine water or the mode of action of pollutants involved. The work we report was undertaken to determine whether the toxic mode of action of an acid water effluent involves any aspect of the respiratory processes in three species of aquatic insect larvae. Although respirometry can be valuable in detecting signs of metabolic involvement, one must be aware that it is not a technique for the identification of specific toxic mechanisms.

  11. Inorganic pigments made from the recycling of coal mine drainage treatment sludge.

    PubMed

    Marcello, R R; Galato, S; Peterson, M; Riella, H G; Bernardin, A M

    2008-09-01

    Continuous industrial development increases energy consumption and, consequently, the consumption of fossil fuels. Coal mineral has been used in Brazil as a solid fuel for thermoelectric generators for several years. However, coal exploitation affects the environment intensely, mainly because Brazilian coal contains excess ash and pyrite (iron disulfide). According to the local coal industry syndicate, the average annual coal run per mine is 6 million ton/year; 3.5 million ton/year are rejected and disposed of in landfills. Besides pyrite, Brazilian coal contains Mn, Fe, Cu, Pb, Zn, Ge, Se, and Co. Additionally, the water used for coal beneficiation causes pyrite oxidation, forming an acid mine drainage (AMD). This drainage solubilizes the metals, transporting them into the environment, making treatment a requirement. This work deals with the use of sedimented residue from treated coal mine drainage sludge to obtain inorganic pigments that could be used in the ceramic industry. The residue was dried, ground and calcined ( approximately 1250 degrees C). The calcined pigment was then micronized (D(50) approximately 2mum). Chemical (XRF), thermal (DTA/TG), particle size (laser), and mineralogical (XRD) analyses were carried out on the residue. After calcination and micronization, mineralogical analyses (XRD) were used to determine the pigment structure at 1250 degrees C. Finally, the pigments were mixed with transparent glaze and fired in a laboratory roller kiln (1130 degrees C, 5min). The results were promising, showing that brown colors can be obtained with pigments made by residues. PMID:17703872

  12. Incorporating Geochemical And Microbial Kinetics In Reactive Transport Models For Generation Of Acid Rock Drainage

    NASA Astrophysics Data System (ADS)

    Andre, B. J.; Rajaram, H.; Silverstein, J.

    2010-12-01

    Acid mine drainage, AMD, results from the oxidation of metal sulfide minerals (e.g. pyrite), producing ferrous iron and sulfuric acid. Acidophilic autotrophic bacteria such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans obtain energy by oxidizing ferrous iron back to ferric iron, using oxygen as the electron acceptor. Most existing models of AMD do not account for microbial kinetics or iron geochemistry rigorously. Instead they assume that oxygen limitation controls pyrite oxidation and thus focus on oxygen transport. These models have been successfully used for simulating conditions where oxygen availability is a limiting factor (e.g. source prevention by capping), but have not been shown to effectively model acid generation and effluent chemistry under a wider range of conditions. The key reactions, oxidation of pyrite and oxidation of ferrous iron, are both slow kinetic processes. Despite being extensively studied for the last thirty years, there is still not a consensus in the literature about the basic mechanisms, limiting factors or rate expressions for microbially enhanced oxidation of metal sulfides. An indirect leaching mechanism (chemical oxidation of pyrite by ferric iron to produce ferrous iron, with regeneration of ferric iron by microbial oxidation of ferrous iron) is used as the foundation of a conceptual model for microbially enhanced oxidation of pyrite.