WorldWideScience

Sample records for acid rock drainage

  1. PASSIVE TREATMENT OF ACID ROCK DRAINAGE FROM A SUBSURFACE MINE

    Science.gov (United States)

    Acidic, metal-contaminated drainages are a critical problem facing many areas of the world. Acid rock drainage results when metal sulfide minerals, particularly pyrite, are oxidized by exposure to oxygen and water. The deleterious effects of these drainages on receiving streams a...

  2. Lignor process for acidic rock drainage treatment.

    Science.gov (United States)

    Zhuang, J M; Walsh, T

    2004-09-01

    The process using lignosulfonates for acidic rock drainage (ARD) treatment is referred to as the Lignor process. Lignosulfonates are waste by-products produced in the sulfite pulping process. The present study has shown lignosulfonates are able to protect lime from developing an external surface coating, and hence to favor its dissociation. Further, the addition of lignosulfonates to ARD solutions increased the dotting and settling rate of the formed sludge. The capability of lignosulfonates to form stable metal-lignin complexes makes them very useful in retaining metal ions and thus improving the long-term stability of the sludge against leaching. The Lignor process involves metal sorption with lignosulfonates, ARD neutralization by lime to about pH 7, pH adjustment with caustic soda to 9.4 - 9.6, air oxidation to lower the pH to a desired level, and addition of a minimum amount of FeCl3 for further removal of dissolved metals. The Lignor process removes all concerned metals (especially Al and Mn) from the ARD of the Britannia Mine (located at Britannia Beach, British Columbia, Canada) to a level lower than the limits of the B.C. Regulations. Compared with the high-density sludge (HDS) process, the Lignor process has many advantages, such as considerable savings in lime consumption, greatly reduced sludge volume, and improved sludge stability.

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

    Science.gov (United States)

    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.

  4. Acid rock drainage and climate change

    Science.gov (United States)

    Nordstrom, D. Kirk

    2009-01-01

    Rainfall events cause both increases and decreases in acid and metals concentrations and their loadings from mine wastes, and unmined mineralized areas, into receiving streams based on data from 3 mines sites in the United States and other sites outside the US. Gradual increases in concentrations occur during long dry spells and sudden large increases are observed during the rising limb of the discharge following dry spells (first flush). By the time the discharge peak has occurred, concentrations are usually decreased, often to levels below those of pre-storm conditions and then they slowly rise again during the next dry spell. These dynamic changes in concentrations and loadings are related to the dissolution of soluble salts and the flushing out of waters that were concentrated by evaporation. The underlying processes, pyrite oxidation and host rock dissolution, do not end until the pyrite is fully weathered, which can take hundreds to thousands of years. These observations can be generalized to predict future conditions caused by droughts related to El Ni??o and climate change associated with global warming. Already, the time period for dry summers is lengthening in the western US and rainstorms are further apart and more intense when they happen. Consequently, flushing of inactive or active mine sites and mineralized but unmined sites will cause larger sudden increases in concentrations that will be an ever increasing danger to aquatic life with climate change. Higher average concentrations will be observed during longer low-flow periods. Remediation efforts will have to increase the capacity of engineered designs to deal with more extreme conditions, not average conditions of previous years.

  5. Modeling acid mine drainage in waste rock dumps

    Energy Technology Data Exchange (ETDEWEB)

    Lefebvre, R. [INRS, Quebec (Canada)

    1995-03-01

    Acid mine drainage (AMD) results from the oxidation of sulfides present in mine wastes. The acidity generated by these reactions creates conditions under which metals can be leached and represent a threat for surface and ground waters. Even though leachate collection and neutralization are used to treat the problem, the industry is looking for methods to predict and prevent the generation of AMD at new sites and control methods for sites already producing AMD. Waste rock dumps are generally very large accumulations of barren rocks extracted from open pits to access ore bodies. These rocks contain sulfides, most commonly pyrite, and often generate AMD at rates much higher than in mine tailings which are fine grained by-products of milling operations. Numerous coupled physical processes are involved in AMD production in waste rocks. Sulfide oxidation reactions are strongly exothermic and temperatures beyond 70{degrees}C have been measured in some dumps. That heat is transfered by conduction and fluid advection. Dumps have thick partly saturated zones through which gases flow under thermal gradients and water infiltrates. Oxygen is required by the oxidation reactions and is supplied by diffusion and advection. The reaction products are carried in solution in very concentrated leachates. Numerical modeling of AMD aims to (1) provide a better understanding of the physical processes involved in AMD, (2) allow the integration of available waste rock characterization data, (3) indicate new data or studies which are required to fill the gaps in our quantitative understanding of AMD processes, and (4) supply a tool for the prediction of AMD production, taking into account the impact of control methods. These objectives can only be met through sustained research efforts. This study is part of a wider research effort which as been on-going at La Mine Doyon since 1991.

  6. Reduction of acid rock drainage using steel slag in cover systems over sulfide rock waste piles.

    Science.gov (United States)

    de Almeida, Rodrigo Pereira; Leite, Adilson do Lago; Borghetti Soares, Anderson

    2015-04-01

    The extraction of gold, coal, nickel, uranium, copper and other earth-moving activities almost always leads to environmental damage. In metal and coal extraction, exposure of sulfide minerals to the atmosphere leads to generation of acid rock drainage (ARD) and in underground mining to acid mine drainage (AMD) due to contamination of infiltrating groundwater. This study proposes to develop a reactive cover system that inhibits infiltration of oxygen and also releases alkalinity to increase the pH of generated ARD and attenuate metal contaminants at the same time. The reactive cover system is constructed using steel slag, a waste product generated from steel industries. This study shows that this type of cover system has the potential to reduce some of the adverse effects of sulfide mine waste disposal on land. Geochemical and geotechnical characterization tests were carried out. Different proportions of sulfide mine waste and steel slag were studied in leachate extraction tests. The best proportion was 33% of steel slag in dry weight. Other tests were conducted as follows: soil consolidation, saturated permeability and soil water characteristic curve. The cover system was numerically modeled through unsaturated flux analysis using Vadose/w. The solution proposed is an oxygen transport barrier that allows rain water percolation to treat the ARD in the waste rock pile. The results showed that the waste pile slope is an important factor and the cover system must have 5 m thickness to achieve an acceptable effectiveness. © The Author(s) 2015.

  7. COMPOST-FREE BIOREACTOR TREATMENT OF ACID ROCK DRAINAGE LEVIATHAN MINE, CALIFORNIA INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    As part of the Superfund Innovative Technology Evaluation (SITE) program, an evaluation of the compost-free bioreactor treatment of acid rock drainage (ARD) from the Aspen Seep was conducted at the Leviathan Mine Superfund site located in a remote, high altitude area of Alpine Co...

  8. COMPOST-FREE BIOLOGICAL TREATMENT OF ACID ROCK DRAINAGE, TECHNICAL EVALUATION BULLETIN

    Science.gov (United States)

    As part of the Superfund Innovative Technology Evaluation (SITE) program, an evaluation of the compost-free bioreactor treatment of acid rock drainage (ARD) from the Aspen Seep was conducted at the Leviathan Mine Superfund site located in a remote, high altitude area of Alpine Co...

  9. COMPOST-FREE BIOREACTOR TREATMENT OF ACID ROCK DRAINAGE - TECHNOLOGY CAPSULE

    Science.gov (United States)

    As part of the Superfund Innovative Technology Evaluation (SITE) program, an evaluation of the compost-free bioreactor treatment of acid rock drainage (ARD) from the Aspen Seep was conducted at the Leviathan Mine Superfund site located in a remote, high altitude area of Alpine Co...

  10. Microbial exoenzymes as bioindicators of acid rock drainage impacts in the Finniss River

    International Nuclear Information System (INIS)

    Hammerton, K.M.

    2002-01-01

    Sediment samples were collected from several sites along the East Branch of the Finniss River during the dry season (June, 1999), when the East Branch is drying into a series of ponds. The sites included those upstream from the Rum Jungle mine site (EB8A, EB8B, FCA, FCB), a site receiving acid leachate from the waste rock (WO), sites downstream from the mine that are impacted by acid and metal contamination (EB6, TCP, EB5D, EB4U, EB2) and reference sites not subject to acid rock drainage (HS, EB4S, LFRB). Exoenzyme activities were measured with a spectrofluorometric technique that involved measuring the increase in fluorescence when an artificial fluorogenic substrate (that mimics the natural substrate) is hydrolysed to a highly fluorescent product. The present findings indicate that the acid rock drainage impacted sediments contain acidophilic, heterotrophic microorganisms, bacteria and/or fungi, producing extracellular enzymes adapted to the acid conditions. This study has demonstrated that measurements of extracellular enzyme activities in river sediments provide a rapid, sensitive technique for determining microbial activity and productivity. In aquatic ecosystems some exoenzymes, particularly leucine-aminopeptidase, could be used as bioindicators of pollution from acid rock drainage

  11. Mixing-controlled uncertainty in long-term predictions of acid rock drainage from heterogeneous waste-rock piles

    Science.gov (United States)

    Pedretti, D.; Beckie, R. D.; Mayer, K. U.

    2015-12-01

    The chemistry of drainage from waste-rock piles at mine sites is difficult to predict because of a number of uncertainties including heterogeneous reactive mineral content, distribution of minerals, weathering rates and physical flow properties. In this presentation, we examine the effects of mixing on drainage chemistry over timescales of 100s of years. We use a 1-D streamtube conceptualization of flow in waste rocks and multicomponent reactive transport modeling. We simplify the reactive system to consist of acid-producing sulfide minerals and acid-neutralizing carbonate minerals and secondary sulfate and iron oxide minerals. We create multiple realizations of waste-rock piles with distinct distributions of reactive minerals along each flow path and examine the uncertainty of drainage geochemistry through time. The limited mixing of streamtubes that is characteristic of the vertical unsaturated flow in many waste-rock piles, allows individual flowpaths to sustain acid or neutral conditions to the base of the pile, where the streamtubes mix. Consequently, mixing and the acidity/alkalinity balance of the streamtube waters, and not the overall acid- and base-producing mineral contents, control the instantaneous discharge chemistry. Our results show that the limited mixing implied by preferential flow and the heterogeneous distribution of mineral contents lead to large uncertainty in drainage chemistry over short and medium time scales. However, over longer timescales when one of either the acid-producing or neutralizing primary phases is depleted, the drainage chemistry becomes less controlled by mixing and in turn less uncertain. A correct understanding of the temporal variability of uncertainty is key to make informed long-term decisions in mining settings regarding the management of waste material.

  12. A review of acid drainage from waste rock dumps and mine sites (Australian and Scandinavia)

    International Nuclear Information System (INIS)

    Harries, J.R.

    1990-05-01

    This report reviews the literature from Australia and Scandinavia on acid drainage from pyritic waste rock dumps with an emphasis on measurements and theory of processes that control the rage of oxidation and the release of pollutants. Conditions within waste rock dumps have been measured at several mine sites and a range of rehabilitation treatments have been tried to reduce the release of pollutants. A number of models have been proposed to calculate air flow, water transport and geochemistry. The data and experience at the mine sites are compared with predictions of the models. Details of Australian and Swedish mine sites where waste rock is a source of acid drainage are described in the Appendices. 92 refs., 2 tabs., 10 figs

  13. Assessment of two kinetic tests to predict the acid mine drainage in waste rock samples of a uranium mine

    OpenAIRE

    Abreu,Adriana Trópia de; Faria,Efigênia Miranda de; Chaves,Carla Thamilis Fonseca; Leite,Adilson do Lago; Lena,Jorge Carvalho de

    2014-01-01

    Acid mine drainage is the result of the oxidation process of sulfide bearing rocks. This process occurs when the sulfide material is exposed to atmospheric conditions. Under these conditions, successive oxidation reactions yield sulfuric acid generating acidic waters. This problem becomes more serious when the surrounding rocks are not able to neutralize the acid. The low pH condition of the drained water accelerates the solubility process of solid materials (rocks, soils and sediments) and f...

  14. Acidic Microenvironments in Waste Rock Characterized by Neutral Drainage: Bacteria–Mineral Interactions at Sulfide Surfaces

    Directory of Open Access Journals (Sweden)

    John W. Dockrey

    2014-03-01

    Full Text Available Microbial populations and microbe-mineral interactions were examined in waste rock characterized by neutral rock drainage (NRD. Samples of three primary sulfide-bearing waste rock types (i.e., marble-hornfels, intrusive, exoskarn were collected from field-scale experiments at the Antamina Cu–Zn–Mo mine, Peru. Microbial communities within all samples were dominated by neutrophilic thiosulfate oxidizing bacteria. However, acidophilic iron and sulfur oxidizers were present within intrusive waste rock characterized by bulk circumneutral pH drainage. The extensive development of microbially colonized porous Fe(III (oxyhydroxide and Fe(III (oxyhydroxysulfate precipitates was observed at sulfide-mineral surfaces during examination by field emission-scanning electron microscopy-energy dispersive X-ray spectroscopy (FE-SEM-EDS. Linear combination fitting of bulk extended X-ray absorption fine structure (EXAFS spectra for these precipitates indicated they were composed of schwertmannite [Fe8O8(OH6–4.5(SO41–1.75], lepidocrocite [γ-FeO(OH] and K-jarosite [KFe3(OH6(SO42]. The presence of schwertmannite and K-jarosite is indicative of the development of localized acidic microenvironments at sulfide-mineral surfaces. Extensive bacterial colonization of this porous layer and pitting of underlying sulfide-mineral surfaces suggests that acidic microenvironments can play an important role in sulfide-mineral oxidation under bulk circumneutral pH conditions. These findings have important implications for water quality management in NRD settings.

  15. Policy for metal leaching and acid rock drainage at mine sites in British Columbia

    International Nuclear Information System (INIS)

    1998-07-01

    One of the major environmental issues facing the provincial government of British Columbia is the prevention of environmental impacts from metal leaching and acid rock drainage (ML/ARD). The government's major challenge in regulating ML/ARD is to ensure that all mines are planned and operated in a manner that allows for effective problem detection and mitigation, and that the mines emphasize problem prevention at the outset. This paper reviews the legislated requirements regarding ML/ARD prevention and lists guiding principles for the regulation of ML/ARD in the province. Some of the measures to predict and to mitigate ML/ARD include underwater storage of problematic materials, engineered covers, blending of wastes and drainage collection and treatment. Requirements applicable to construction materials, backfill, geotechnical and hydrological considerations, and security of funds for ML/ARD measures are also discussed

  16. Acid Rock Drainage or Not—Oxidative vs. Reductive Biofilms—A Microbial Question

    Directory of Open Access Journals (Sweden)

    Margarete Kalin

    2018-05-01

    Full Text Available Measures to counteract Acid Rock Drainage (ARD generation need to start at the mineral surface, inhibiting mineral-oxidizing, acidophilic microbes. Laboratory and long-term field tests with pyrite-containing mining wastes—where carbonaceous phosphate mining waste (CPMW was added—resulted in low acidity and near neutral drainage. The effect was reproducible and confirmed by several independent research groups. The improved drainage was shown to involve an organic coating, likely a biofilm. The biofilm formation was confirmed when CPMW was added to lignite coal waste with an initial pH of 1. Forty-five days after the addition, the coal waste was dominated by heterotrophic microorganisms in biofilms. Reviewing the scientific literature provides ample support that CPMW has physical and chemical characteristics which can induce a strong inhibitory effect on sulphide oxidation by triggering the formation of an organic coating, a biofilm, over the mineral surface. CPMW characteristics provide the cornerstone of a new technology which might lead to reduction of sulphide oxidation in mine wastes. A hypothesis for testing this technology is presented. The use of such a technology could result in an economical and sustainable approach to mine waste and water management.

  17. Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron

    Energy Technology Data Exchange (ETDEWEB)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A., E-mail: jimfield@email.arizona.edu

    2016-05-05

    Highlights: • Electron donor from zero-valent iron (ZVI) drives sulfate reduction to sulfide. • Sulfide converts soluble heavy metals into sulfide minerals. • Excess sulfide is sequestered by iron preventing discharge. • Corrosion of ZVI consumes acidity in acid rock drainage. • ZVI as reactive material outlasted limestone in removing heavy metals. - Abstract: This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.

  18. Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron

    International Nuclear Information System (INIS)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A.

    2016-01-01

    Highlights: • Electron donor from zero-valent iron (ZVI) drives sulfate reduction to sulfide. • Sulfide converts soluble heavy metals into sulfide minerals. • Excess sulfide is sequestered by iron preventing discharge. • Corrosion of ZVI consumes acidity in acid rock drainage. • ZVI as reactive material outlasted limestone in removing heavy metals. - Abstract: This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.

  19. Effects of bacterial action on waste rock producing acid drainage in the Brazilian first uranium mine

    International Nuclear Information System (INIS)

    Rey-Silva, Daniela V.F.M.; Oliveira, Alexandre P. de; Geraldo, Bianca; Campos, Michele B.; Azevedo, Heliana de; Barreto, Rodrigo P.; Souza-Santos, Marcio L. de

    2009-01-01

    This work is an evolution of the methodology showed in the paper 'Study of waste of waste rock piles producing acid drainage in the Brazilian first uranium mine', also submitted for INAC2009. Therefore, the present work also related to the determination of chemical species leaching from waste rock pile 4 (WRP4) of the Uranium Mine and Milling Facility located in the Pocos de Caldas Plateau, as well as the generation of acid waters. With the previous experimental setup, it has been observed that not only water and available oxygen are significant to pyrite oxidation reaction, but bacterial activity as well. As a first approach, the present work addresses the same experiment, but now testing without the influence of bacterial action. Therefore, the new methodology and experimental setup is now capable of determining the acidity of water in contact with material from the WRP4 and the concentration of chemical species dissolved as function of time. Such would also show the extent of bacterial action interference on the pyrite oxidation reaction. Results are based on mass balances comparing concentrations of chemical species in the waste rock before the experiment and in the waste rock plus the remaining water after the experiment. In addition, the evolution of the pH and EMF (electromotive force) values along with chemical species quantified through the experiment are presented through graphics. That is followed by discussions on the significance of such results in terms of concentration of the involved chemical species. The present work has also shown the need of improving the injection of air into the system. A more sophisticated experimental setup should be assembled in the near future, which would allow the quantification of differences between experimental tests with and without bacterial action. (author)

  20. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage

    Energy Technology Data Exchange (ETDEWEB)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A., E-mail: jimfield@email.arizona.edu

    2016-11-05

    Highlights: • Algal biomass can serve as an electron donor to drive reduction of sulfate to sulfide. • Biogenic sulfide precipitates Cu{sup 2+} as stable sulfide mineral. • Cu{sup +2} removal in sulfidogenic bioreactors amended with algal biomass exceeded 99.5%. • Acidity in synthetic acid rock drainage was consumed by sulfate reduction. - Abstract: This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H{sub 2}SO{sub 4} and Cu{sup 2+}. Sulfate, sulfide, Cu{sup 2+} and pH were monitored throughout the experiment of 123 d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7 mg SO{sub 4}{sup 2−} d{sup −1}) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu{sup 2+} removal were observed in the endogenous control. In algae amended-columns, Cu{sup 2+} was precipitated with biogenic H{sub 2}S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry.

  1. Incorporating Geochemical And Microbial Kinetics In Reactive Transport Models For Generation Of Acid Rock Drainage

    Science.gov (United States)

    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. Using literature data, a rate expression for microbial consumption of ferrous iron is developed that accounts for oxygen, ferrous iron and pH limitation. Reaction rate expressions for oxidation of pyrite and chemical oxidation of ferrous iron are selected from the literature. A completely mixed stirred tank reactor (CSTR) model is implemented coupling the kinetic rate expressions, speciation calculations and flow. The model simulates generation of AMD and effluent chemistry that qualitatively agrees with column reactor and single rock experiments. A one dimensional reaction

  2. Revegetation of Acid Rock Drainage (ARD) Producing Slope Surface Using Phosphate Microencapsulation and Artificial Soil

    Science.gov (United States)

    Kim, Jae Gon

    2017-04-01

    Oxidation of sulfides produces acid rock drainage (ARD) upon their exposure to oxidation environment by construction and mining activities. The ARD causes the acidification and metal contamination of soil, surface water and groundwater, the damage of plant, the deterioration of landscape and the reduction of slope stability. The revegetation of slope surface is one of commonly adopted strategies to reduce erosion and to increase slope stability. However, the revegetation of the ARD producing slope surface is frequently failed due to its high acidity and toxic metal content. We developed a revegetation method consisting of microencapsualtion and artificial soil in the laboratory. The revegetation method was applied on the ARD producing slope on which the revegetation using soil coverage and seeding was failed and monitored the plant growth for one year. The phosphate solution was applied on sulfide containing rock to form stable Fe-phosphate mineral on the surface of sulfide, which worked as a physical barrier to prevent contacting oxidants such as oxygen and Fe3+ ion to the sulfide surface. After the microencapsulation, two artificial soil layers were constructed. The first layer containing organic matter, dolomite powder and soil was constructed at 2 cm thickness to neutralize the rising acidic capillary water from the subsurface and to remove the dissolved oxygen from the percolating rain water. Finally, the second layer containing seeds, organic matter, nutrients and soil was constructed at 3 cm thickness on the top. After application of the method, the pH of the soil below the artificial soil layer increased and the ARD production from the rock fragments reduced. The plant growth showed an ordinary state while the plant died two month after germination for the previous revegetation trial. No soil erosion occurred from the slope during the one year field test.

  3. Microbacter margulisiae gen. nov., sp. nov., a novel propionigenic bacterium isolated from sediments of an acid rock drainage pond

    NARCIS (Netherlands)

    Sanchez Andrea, I.; Luis Sanz, J.; Stams, A.J.M.

    2014-01-01

    A novel anaerobic propionigenic bacterium, strain ADRIT, was isolated from sediment of an acid rock drainage environment (Tinto River, Spain). Cells were small (0.4-0.6 x 1-1.7 µm), non-motile and non-spore forming rods. Cells possessed a Gram-negative cell wall structure and were vancomycin

  4. Study of waste rock piles producing acid drainage in the Brazilian first uranium mine

    International Nuclear Information System (INIS)

    Oliveira, Alexandre P. de; Rey-Silva, Daniela V.F.M.; Barreto, Rodrigo P.; Souza-Santos, Marcio L. de; Veronesi, Luciano da S.

    2009-01-01

    The Uranium Mine and Milling Facility located in the Pocos de Caldas Plateau stopped operating since mid-1990's and remediation actions for the mine areas are going to take place in the near future. However, environmental concerns should be addressed such as acid mine drainage (AMD) in the waste rock piles (WRPs), pit mine, and tailing dam, all driven by pyrite oxidation reactions. The AMD process leaches both heavy metals and radionuclides pollutants through the soil. This work shows the methodology applied for the determination of chemical species leaching from WRP4 as well the generation of acid waters. An experimental setup has been assembled to determine the acidity of water in contact with samples of material from the WRP4. Results are presented along a list of chemical species found in the remaining water. That is followed by discussions regarding its pH and chemical composition measured during the experiments. It has been observed that not only water and available oxygen are significant to the pyrite oxidation reaction, but also bacterial activity. This last effect should be addressed in the near future. Moreover, various important aspects regarding the experimental setup were noticed and are addressed as propositions for the continuation of the present work. (author)

  5. Automated classification of Acid Rock Drainage potential from Corescan drill core imagery

    Science.gov (United States)

    Cracknell, M. J.; Jackson, L.; Parbhakar-Fox, A.; Savinova, K.

    2017-12-01

    Classification of the acid forming potential of waste rock is important for managing environmental hazards associated with mining operations. Current methods for the classification of acid rock drainage (ARD) potential usually involve labour intensive and subjective assessment of drill core and/or hand specimens. Manual methods are subject to operator bias, human error and the amount of material that can be assessed within a given time frame is limited. The automated classification of ARD potential documented here is based on the ARD Index developed by Parbhakar-Fox et al. (2011). This ARD Index involves the combination of five indicators: A - sulphide content; B - sulphide alteration; C - sulphide morphology; D - primary neutraliser content; and E - sulphide mineral association. Several components of the ARD Index require accurate identification of sulphide minerals. This is achieved by classifying Corescan Red-Green-Blue true colour images into the presence or absence of sulphide minerals using supervised classification. Subsequently, sulphide classification images are processed and combined with Corescan SWIR-based mineral classifications to obtain information on sulphide content, indices representing sulphide textures (disseminated versus massive and degree of veining), and spatially associated minerals. This information is combined to calculate ARD Index indicator values that feed into the classification of ARD potential. Automated ARD potential classifications of drill core samples associated with a porphyry Cu-Au deposit are compared to manually derived classifications and those obtained by standard static geochemical testing and X-ray diffractometry analyses. Results indicate a high degree of similarity between automated and manual ARD potential classifications. Major differences between approaches are observed in sulphide and neutraliser mineral percentages, likely due to the subjective nature of manual estimates of mineral content. The automated approach

  6. Enriching acid rock drainage related microbial communities from surface-deposited oil sands tailings.

    Science.gov (United States)

    Dean, Courtney; Xiao, Yeyuan; Roberts, Deborah J

    2016-10-01

    Little is known about the microbial communities native to surface-deposited pyritic oil sands tailings, an environment where acid rock drainage (ARD) could occur. The goal of this study was to enrich sulfur-oxidizing organisms from these tailings and determine whether different populations exist at pH levels 7, 4.5, and 2.5. Using growth-based methods provides model organisms for use in the future to predict potential activities and limitations of these organisms and to develop possible control methods. Thiosulfate-fed enrichment cultures were monitored for approximately 1 year. The results showed that the enrichments at pH 4.5 and 7 were established quicker than at pH 2.5. Different microbial community structures were found among the 3 pH environments. The sulfur-oxidizing microorganisms identified were most closely related to Halothiobacillus neapolitanus, Achromobacter spp., and Curtobacterium spp. While microorganisms related to Chitinophagaceae and Acidocella spp. were identified as the only possible iron-oxidizing and -reducing microbes. These results contribute to the general knowledge of the relatively understudied microbial communities that exist in pyritic oil sands tailings and indicate these communities may have a potential role in ARD generation, which may have implications for future tailings management.

  7. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage.

    Science.gov (United States)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A

    2016-11-05

    This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H2SO4 and Cu(2+). Sulfate, sulfide, Cu(2+) and pH were monitored throughout the experiment of 123d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7mg SO4(2-) d(-1)) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu(2+) removal were observed in the endogenous control. In algae amended-columns, Cu(2+) was precipitated with biogenic H2S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Characterization of Green Liquor Dregs, Potentially Useful for Prevention of the Formation of Acid Rock Drainage

    Directory of Open Access Journals (Sweden)

    Maria Mäkitalo

    2014-04-01

    Full Text Available Using alternative materials such as residual products from other industries to mitigate the negative effects of acid rock drainage would simultaneously solve two environmental problems. The main residual product still landfilled by sulphate paper mills is the alkaline material green liquor dregs (GLD. A physical, mineralogical and chemical characterization of four batches of GLD was carried out to evaluate the potential to use it as a sealing layer in the construction of dry covers on sulphide-bearing mine waste. GLD has relatively low hydraulic conductivity (10−8 to 10−9 m/s, a high water retention capacity (WRC and small particle size. Whilst the chemical and mineralogical composition varied between the different batches, these variations were not reflected in properties such as hydraulic conductivity and WRC. Due to relatively low trace element concentrations, leaching of contaminants from the GLD is not a concern for the environment. However, GLD is a sticky material, difficult to apply on mine waste deposits and the shear strength is insufficient for engineering applications. Therefore, improving the mechanical properties is necessary. In addition, GLD has a high buffering capacity indicating that it could act as an alkaline barrier. Once engineering technicalities have been overcome, the long-term effectiveness of GLD should be studied, especially the effect of aging and how the sealing layer would be engineered in respect to topography and climatic conditions.

  9. Acid rock drainage passive remediation using alkaline clay and impacts of vegetation and saturated sand barrier

    Science.gov (United States)

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

    2017-12-01

    Acid rock drainage (ARD) caused by abundance of coal refuse (CR) deposits in mining regions requires adequate treatment to prevent serious water pollution due to its acidity and high concentrations of sulfate and metals/metalloids. Over the past decades, various approaches have been explored and developed to remediate ARD. This study uses laboratory experiments to investigate the effectiveness and impacts of ARD passive remediation using alkaline clay (AC), a by-product of the aluminum refining process. Twelve column kinetic leaching experiments were set up with CR/AC mixing ratios ranging from 1%AC to 10%AC. Samples were collected from these columns to measure the pH, sulfate, metals/metalloids, acidity and alkalinity. Additional tests of XRD and acid base accounting were also conducted to better characterize the mineral phase in terms of the alkalinity and acidity potential. Based on the leachate measurement results, these columns were further classified into two groups of neutral/near neutral pH and acidic pH for further analysis. In addition, impacts of the vegetation and saturated sand layer on the remediation effectiveness were explored. The results of our long-term (more than three years in some cases) laboratory experiments show that AC is an effective ARD remediation material for the neutralization of leachate pH and immobilization of sulfate and metals such as Fe, Mn, Cu, Zn, Ni, Pb, Cd, Co. The CR/AC mixing ratios higher than 3%AC are found to be effective, with 10% close to optimal. Moreover, the results demonstrate the benefits of using vegetation and a saturated sand barrier. Vegetation acted as a phytoaccumulation/phytoextraction agent, causing an additional immobilization of metals. The saturated sand barrier blocked the oxygen and water diffusion downwards, leading to a reduction of the pyrite oxidation rate. Finally, the proposed remediation approach shows that the acidity consumption will likely occur before all the alkalinity is exhausted

  10. Trace metal mobilization from oil sands froth treatment thickened tailings exhibiting acid rock drainage.

    Science.gov (United States)

    Kuznetsova, Alsu; Kuznetsov, Petr; Foght, Julia M; Siddique, Tariq

    2016-11-15

    Froth treatment thickened tailings (TT) are a waste product of bitumen extraction from surface-mined oil sands ores. When incubated in a laboratory under simulated moist oxic environmental conditions for ~450d, two different types of TT (TT1 and TT2) exhibited the potential to generate acid rock drainage (ARD) by producing acid leachate after 250 and 50d, respectively. We report here the release of toxic metals from TT via ARD, which could pose an environmental threat if oil sands TT deposits are not properly managed. Trace metal concentrations in leachate samples collected periodically revealed that Mn and Sr were released immediately even before the onset of ARD. Spikes in Co and Ni concentrations were observed both pre-ARD and during active ARD, particularly in TT1. For most elements measured (Fe, Cr, V, As, Cu, Pb, Zn, Cd, and Se), leaching was associated with ARD production. Though equivalent acidification (pH2) was achieved in leachate from both TT types, greater metal release was observed from TT2 where concentrations reached 10,000ppb for Ni, 5000ppb for Co, 3000ppb for As, 2000ppb for V, and 1000ppb for Cr. Generally, metal concentrations decreased in leachate with time during ARD and became negligible by the end of incubation (~450d) despite appreciable metals remaining in the leached TT. These results suggest that using TT for land reclamation purposes or surface deposition for volume reduction may unfavorably impact the environment, and warrants application of appropriate strategies for management of pyrite-enriched oil sands tailings streams. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Oil sands thickened froth treatment tailings exhibit acid rock drainage potential during evaporative drying.

    Science.gov (United States)

    Kuznetsov, Petr; Kuznetsova, Alsu; Foght, Julia M; Siddique, Tariq

    2015-02-01

    Bitumen extraction from oil sands ores after surface mining produces different tailings waste streams: 'froth treatment tailings' are enriched in pyrite relative to other streams. Tailings treatment can include addition of organic polymers to produce thickened tailings (TT). TT may be further de-watered by deposition into geotechnical cells for evaporative drying to increase shear strength prior to reclamation. To examine the acid rock drainage (ARD) potential of TT, we performed predictive analyses and laboratory experiments on material from field trials of two types of thickened froth treatment tailings (TT1 and TT2). Acid-base accounting (ABA) of initial samples showed that both TT1 and TT2 initially had net acid-producing potential, with ABA values of -141 and -230 t CaCO₃ equiv. 1000 t(-1) of TT, respectively. In long-term kinetic experiments, duplicate ~2-kg samples of TT were incubated in shallow trays and intermittently irrigated under air flow for 459 days to simulate evaporative field drying. Leachates collected from both TT samples initially had pH~6.8 that began decreasing after ~50 days (TT2) or ~250 days (TT1), stabilizing at pH~2. Correspondingly, the redox potential of leachates increased from 100-200 mV to 500-580 mV and electrical conductivity increased from 2-5 dS m(-1) to 26 dS m(-1), indicating dissolution of minerals during ARD. The rapid onset and prolonged ARD observed with TT2 is attributed to its greater pyrite (13.4%) and lower carbonate (1.4%) contents versus the slower onset of ARD in TT1 (initially 6.0% pyrite and 2.5% carbonates). 16S rRNA gene pyrosequencing analysis revealed rapid shift in microbial community when conditions became strongly acidic (pH~2) favoring the enrichment of Acidithiobacillus and Sulfobacillus bacteria in TT. This is the first report showing ARD potential of TT and the results have significant implications for effective management of pyrite-enriched oil sands tailings streams/deposits. Copyright © 2014

  12. Impact on sediments and water by release of copper from chalcopyrite bearing rock due to acidic mine drainage

    Science.gov (United States)

    Shukla, Anoop Kant; Pradhan, Manoj; Tiwari, Onkar Nath

    2018-04-01

    Mining activity causes transition of rock-mass from its original position in earth into open environment. The action of environmental elements such air, water, microorganisms leads to oxidation of minerals which constitute the rock. The oxidation of sulphide minerals in presence of moisture releases acidic mine discharge (AMD). The acidic nature of AMD causes leaching of metals from rock minerals. Dissolution of other minerals may occur upon reaction with AMD. Chalcopyrite (CuFeS2) undergoes oxidation in acidic condition releasing copper among other products. This study reveals contamination of copper in sediment samples and seepage water from the tailing dam of a large copper project in located in central India. Elevation was studied using GIS to ascertain to the topographic elevation of tailing dam area. It was located at relatively high altitude causing seepage to flow away from tailing dam. The seepage water from tailing dam was found to be acidic with mean pH value of 4.0 and elevated copper content. Similarly, sediments from seepage water flow displayed elevated copper concentration. The copper concentration in seepage water was found with a mean value of 10.73 mg/l. The sediments from seepage water flow also displayed elevated copper concentration with mean value of 26.92 g/kg. This indicates impact on sediments by release of copper due to acidic mine drainage.

  13. Acid mine drainage

    Science.gov (United States)

    Bigham, Jerry M.; Cravotta, Charles A.

    2016-01-01

    Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

  14. Geologic and mineralogic controls on acid and metal-rich rock drainage in an alpine watershed, Handcart Gulch, Colorado

    Science.gov (United States)

    Bove, Dana J.; Caine, Jonathan S.; Lowers, Heather

    2012-01-01

    The surface and subsurface geology, hydrothermal alteration, and mineralogy of the Handcart Gulch area was studied using map and drill core data as part of a multidisciplinary approach to understand the hydrology and affects of geology on acid-rock drainage in a mineralized alpine watershed. Handcart Gulch was the locus of intense hydrothermal alteration that affected an area of nearly 3 square kilometers. Hydrothermal alteration and accompanied weak mineralization are spatially and genetically associated with small dacite to low-silica rhyolite stocks and plugs emplaced about 37-36 Ma. Felsic lithologies are commonly altered to a quartz-sericite-pyrite mineral assemblage at the surface, but alteration is more variable in the subsurface, ranging from quartz-sericite-pyrite-dominant in upper core sections to a propylitic variant that is more typical in deeper drill core intervals. Late-stage, hydrothermal argillic alteration [kaolinite and(or) smectite] was superimposed over earlier-formed alteration assemblages in the felsic rocks. Smectite in this late stage assemblage is mostly neoformed resulting from dissolution of chlorite, plagioclase, and minor illite in more weakly altered rocks. Hydrothermally altered amphibolites are characterized by biotitic alteration of amphibole, and subsequent alteration of both primary and secondary biotite to chlorite. Whereas pyrite is present both as disseminations and in small veinlets in the felsic lithologies, it is mostly restricted to small veinlets in the amphibolites. Base-metal sulfides including molybdenite, chalcopyrite, sphalerite, and galena are present in minor to trace amounts in the altered rocks. However, geologic data in conjunction with water geochemical studies indicate that copper mineralization may be present in unknown abundance in two distinct areas. The altered rocks contain an average of 8 weight percent fine pyrite that is largely devoid of metals in the crystal structure, which can be a significant

  15. A geochemical characterization of cold-water natural acid rock drainage at the Zn–Pb XY deposit, Yukon, Canada

    International Nuclear Information System (INIS)

    Gault, Kristen B.; Gammon, Paul; Fortin, Danielle

    2015-01-01

    Highlights: • Characterizes the waters and minerals of a natural acid rock drainage (ARD). • Demonstrates that cold climate ARD is mostly similar to temperate systems. • Cold-climate differences impact kinetic rates and hydrologic seasonality. • Demonstrates that thermodynamic equilibrium governs the ARD system. • Demonstrates that extraneous inputs can be detected in the system. - Abstract: Acid rock drainage (ARD) is considered to be temperature-limited due to the diminished activity of Fe(II)-oxidizing microbes at low temperatures. Nonetheless, ARD streams are present in cold climates. This study presents a geochemical characterization of a cold climate ARD creek at the Zn–Pb XY deposit in Yukon, Canada, which showed highly elevated concentrations of dissolved zinc (up to 475 mg/L). Acid rock drainage at the XY deposit is likely generated via subsurface abiotic and biotic oxidation of sulfide minerals, and then exits as seeps at the headwaters of the creek. The uppermost reaches of the creek have the lowest pH levels (pH 3.3) and highest metal concentrations, with prolific precipitation of iron-hydroxysulfate and -oxyhydroxide mineral precipitates (schwertmannite, jarosite, and goethite), present as terraced iron formations (TIFs) at one sampling location. The lower reaches of the creek show a progressive pH increase (up to pH level 4.9) which occurs due to Fe(III)- and Al-hydrolysis, the neutralizing influence of carbonate-rich strata and/or ground waters, and dilution by surface waters entering the creek. Progressive pH neutralization causes a change in precipitate mineralogy to X-ray amorphous Al-hydroxysulfates, with a composition similar to aluminite and hydrobasaluminite, and amorphous Al(OH)_3. Natural attenuation of Cd, Zn, and Pb occurred downstream from the headwater seeps, which was likely influenced by adsorption reactions involving both metal-sulfate anions and metal-sulfate ternary complexes. Generally, the concentrations of Cd, Zn, and

  16. Temporal and spatial variability of acid rock drainage in a rehabilitated coal mine, Wangaloa, South Otago, New Zealand

    International Nuclear Information System (INIS)

    Begbie, M.; Craw, D.; Rufaut, C.; Martin, C.

    2007-01-01

    The Wangaloa open cast coal mine ceased operations in 1989, with no restoration of the 252 ha site, and moderate acid rock drainage developed. A major rehabilitation programme was initiated in 2002 with removal of exotic vegetation, and extensive planting (>60,000) of native seedlings was begun in 2003. By 2006, most seedlings were thriving, and, combined with adventive exotic weeds, a 70% vegetation cover had been achieved. The site substrates were highly variable on the 10-100 m 2 scale, and have been characterised by paste pH (>700 measurements). In 2003, substrates had moderate acidity (pH 4.5 ± 0.9) with distinctly acid patches (pH down to 100 samples from 15 sites) were also highly variable spatially and temporally. Incoming stream and rainwater (pH 5-6) chemically interacted with acid substrates, especially waste rock piles that contain pyrite-bearing material, and evolved to lower pH (pH down to 3.4), sulfate-rich waters. A pit lake on the site receives most surface and groundwater runoff, and this lake, with a water residence time of 1-2 yr, controls the site discharge water quality. The lake pH varies on a monthly time-scale from 4.5 to 6.5, synchronised with pH variations in groundwater boreholes in waste rock. In addition, there has been a general increase in pH of the lake during rehabilitation from consistent pH 4.6-4.8 before rehabilitation to near pH 6 during rehabilitation. The sulfate/chloride ratio of lake water has decreased from 20 to <10 during rehabilitation as well. These changes in lake water composition from year to year may be a result of increased input of rainwater that has had less interaction with substrate than runoff water had before rehabilitation began. (author). 23 refs., 10 figs., 1 tab

  17. Acid Mine Drainage Treatment

    National Research Council Canada - National Science Library

    Fripp, Jon

    2000-01-01

    .... Acid mine drainage (AMD) can have severe impacts to aquatic resources, can stunt terrestrial plant growth and harm wetlands, contaminate groundwater, raise water treatment costs, and damage concrete and metal structures...

  18. Acid rock drainage passive remediation using alkaline clay: Hydro-geochemical study and impacts of vegetation and sand on remediation.

    Science.gov (United States)

    Plaza, Fernando; Wen, Yipei; Liang, Xu

    2018-10-01

    Acid rock drainage (ARD) is one of the most adverse environmental problems of the mine industry, especially in regions with an abundance of coal refuse (CR) deposits (e.g. the Northern Appalachian Coalfield in the USA) where surface and ground waters are affected by this pollution due to the acidity and high content of sulfates and heavy metals. This study explores the effectiveness of the ARD passive remediation method using alkaline clay (AC) through a series of static and long-term kinetic laboratory experiments (over three years) complemented with field measurements and geochemical modeling. Two important issues associated with this passive and auto-sustainable ARD remediation method were investigated: 1) the hydrogeochemical study of the mixture in terms of the percentages of AC and CR, and, 2) impacts of vegetation cover and a saturated sand barrier on the remediation. Both the field measurements and the samples used for the experiments came from a local coal waste site. Through the analysis of the field measurements and the outcome of the laboratory experiments and the geochemical modeling, alkaline clay proved to be an effective remediation material for ARD, in terms of achieving a neutral pH in the leachate and immobilization of sulfate and metals such as Fe, Mn, Cu, Zn, Ni, Pb, Cd, Co. Moreover, it has been demonstrated that the use of vegetation and a saturated sand barrier are beneficial. Vegetation acted as a phytoaccumulation/phytoextraction agent, causing an additional immobilization of metals. The saturated sand barrier blocked downward the oxygen and water diffusion, reducing pyrite oxidation rates. The proposed remediation approach ensures that the acidity consumption will likely occur before all the alkalinity is exhausted. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Diel cycling of zinc in a stream impacted by acid rock drainage: Initial results from a new in situ Zn analyzer

    Science.gov (United States)

    Chapin, T.P.; Nimick, D.A.; Gammons, C.H.; Wanty, R.B.

    2007-01-01

    Recent work has demonstrated that many trace metals undergo dramatic diel (24-h) cycles in near neutral pH streams with metal concentrations reproducibly changing up to 500% during the diel period (Nimick et al., 2003). To examine diel zinc cycles in streams affected by acid rock drainage, we have developed a novel instrument, the Zn-DigiScan, to continuously monitor in situ zinc concentrations in near real-time. Initial results from a 3-day deployment at Fisher Creek, Montana have demonstrated the ability of the Zn-DigiScan to record diel Zn cycling at levels below 100 ??g/l. Longer deployments of this instrument could be used to examine the effects of episodic events such as rainstorms and snowmelt pulses on zinc loading in streams affected by acid rock drainage. ?? Springer Science+Business Media B.V. 2006.

  20. U.S. Geological Survey research in Handcart Gulch, Colorado—An alpine watershed with natural acid-rock drainage

    Science.gov (United States)

    Manning, Andrew H.; Caine, Jonathan S.; Verplanck, Philip L.; Bove, Dana J.; Kahn, Katherine G.

    2009-01-01

    Handcart Gulch is an alpine watershed along the Continental Divide in the Colorado Rocky Mountain Front Range. It contains an unmined mineral deposit typical of many hydrothermal mineral deposits in the intermountain west, composed primarily of pyrite with trace metals including copper and molybdenum. Springs and the trunk stream have a natural pH value of 3 to 4. The U.S. Geological Survey began integrated research activities at the site in 2003 with the objective of better understanding geologic, geochemical, and hydrologic controls on naturally occurring acid-rock drainage in alpine watersheds. Characterizing the role of groundwater was of particular interest because mountain watersheds containing metallic mineral deposits are often underlain by complexly deformed crystalline rocks in which groundwater flow is poorly understood. Site infrastructure currently includes 4 deep monitoring wells high in the watershed (300– 1,200 ft deep), 4 bedrock (100–170 ft deep) and 5 shallow (10–30 ft deep) monitoring wells along the trunk stream, a stream gage, and a meteorological station. Work to date at the site includes: geologic mapping and structural analysis; surface sample and drill core mineralogic characterization; geophysical borehole logging; aquifer testing; monitoring of groundwater hydraulic heads and streamflows; a stream tracer dilution study; repeated sampling of surface and groundwater for geochemical analyses, including major and trace elements, several isotopes, and groundwater age dating; and construction of groundwater flow models. The unique dataset collected at Handcart Gulch has yielded several important findings about bedrock groundwater flow at the site. Most importantly, we find that bedrock bulk permeability is nontrivial and that bedrock groundwater apparently constitutes a substantial fraction of the hydrologic budget. This means that bedrock groundwater commonly may be an underappreciated component of the hydrologic system in studies of

  1. Zinc isotope investigation of surface and pore waters in a mountain watershed impacted by acid rock drainage

    Energy Technology Data Exchange (ETDEWEB)

    Aranda, Suzan [Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968 (United States); Borrok, David M., E-mail: dborrok@utep.edu [Department of Geological Sciences, University of Texas at El Paso, El Paso, TX 79968 (United States); Wanty, Richard B. [US Geological Survey, MS 964d, Denver Federal Center, Denver, CO 80225 (United States); Balistrieri, Laurie S. [U.S. Geological Survey, University of Washington, School of Oceanography, Seattle, WA 98195 (United States)

    2012-03-15

    The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the {delta}{sup 66}Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30 Per-Mille-Sign {+-} 0.09 Per-Mille-Sign 2{sigma}). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The {delta}{sup 66}Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80 Per-Mille-Sign {+-} 0.09 Per-Mille-Sign 2{sigma}. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in

  2. Zinc isotope investigation of surface and pore waters in a mountain watershed impacted by acid rock drainage

    International Nuclear Information System (INIS)

    Aranda, Suzan; Borrok, David M.; Wanty, Richard B.; Balistrieri, Laurie S.

    2012-01-01

    The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the δ 66 Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30‰ ± 0.09‰ 2σ). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The δ 66 Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80‰ ± 0.09‰ 2σ. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in soil pore waters. - Highlights: ► Zinc isotopes of water were measured in

  3. Zinc isotope investigation of surface and pore waters in a mountain watershed impacted by acid rock drainage.

    Science.gov (United States)

    Aranda, Suzan; Borrok, David M; Wanty, Richard B; Balistrieri, Laurie S

    2012-03-15

    The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the δ(66)Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30‰±0.09‰ 2σ). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The δ(66)Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80‰±0.09‰ 2σ. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in soil pore waters. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Stochastic multicomponent reactive transport analysis of low quality drainage release from waste rock piles: Controls of the spatial distribution of acid generating and neutralizing minerals.

    Science.gov (United States)

    Pedretti, Daniele; Mayer, K Ulrich; Beckie, Roger D

    2017-06-01

    In mining environmental applications, it is important to assess water quality from waste rock piles (WRPs) and estimate the likelihood of acid rock drainage (ARD) over time. The mineralogical heterogeneity of WRPs is a source of uncertainty in this assessment, undermining the reliability of traditional bulk indicators used in the industry. We focused in this work on the bulk neutralizing potential ratio (NPR), which is defined as the ratio of the content of non-acid-generating minerals (typically reactive carbonates such as calcite) to the content of potentially acid-generating minerals (typically sulfides such as pyrite). We used a streamtube-based Monte-Carlo method to show why and to what extent bulk NPR can be a poor indicator of ARD occurrence. We simulated ensembles of WRPs identical in their geometry and bulk NPR, which only differed in their initial distribution of the acid generating and acid neutralizing minerals that control NPR. All models simulated the same principal acid-producing, acid-neutralizing and secondary mineral forming processes. We show that small differences in the distribution of local NPR values or the number of flow paths that generate acidity strongly influence drainage pH. The results indicate that the likelihood of ARD (epitomized by the probability of occurrence of pH<4 in a mixing boundary) within the first 100years can be as high as 75% for a NPR=2 and 40% for NPR=4. The latter is traditionally considered as a "universally safe" threshold to ensure non-acidic waters in practical applications. Our results suggest that new methods that explicitly account for mineralogical heterogeneity must be sought when computing effective (upscaled) NPR values at the scale of the piles. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Acid rock drainage in the uranium mining and milling site of Pocos de Caldas, Brazil -- duration assessment, pollutant generation modelling and remediation strategies

    International Nuclear Information System (INIS)

    Fernandes, H.M.; Franklin, M.R.

    2002-01-01

    This geochemical modeling work was carried out to simulate the acid drainage generation from one of the waste-rock piles at the Pocos de Caldas uranium mining site. The mathematical code STEADQYL was used. The estimated results were in good agreement for sulphate and uranium concentrations and the duration of the acid water generation was estimated to be about 500 years. The effect of covering the dump with a material that minimized oxygen diffusion was assessed. Projections indicated that covering the dump with a 1.0 m thickness of a material (like clay), which had an oxygen diffusion coefficient of 10 9 m 2 ·s 1 , would reduce the pollutant concentrations to acceptable values. The estimated cost, when using this strategy, would be about US $10 million. (author)

  6. Initial evaluations of the use of microbial measures to quantify impact of acid rock drainage on the Finniss River (east branch)

    International Nuclear Information System (INIS)

    Holden, P.J.; Wilde, K.L.; Stone, D.J.; Ben-David, E.A.; Foster, L.J.

    2002-01-01

    Biological measures assessing the impact of pollution on aquatic ecosystems have been increasingly used over the last ten years to examine ecosystem health. The focus, however, has been on diversity and abundance of higher organisms, such as fish, frogs and macroinvertebrates, and it is desirable that such measures be made across all trophic levels of the ecosystem. In this study, phospholipid-fatty acid analysis and microbial carbon substrate utilisation assays (BIOLOG) of sediment and water samples were conducted to evaluate their usefulness as a measure of the effect of acid rock drainage (ARD) on the East Branch of the Finniss River. Both PLFA, and BIOLOG assays, generate data well suited to multivariate analysis and previous studies of the impact of ARD from the Brukunga mine (South Australia) have demonstrated the ability to distinguish between the effect of ARD, nutrients and dry-land salinity on microbial populations

  7. Role of Lithology and Rock Structure in Drainage Development in ...

    African Journals Online (AJOL)

    Lithology and Rock structure play a vital role in the development of Drainage Network in any drainage basin. The drainage patterns upon land surface develop as directed by the underlying lithology and rock structure. In fact, lithology and rock structure together shape the basin and are decisive parameters of nature and ...

  8. The geochemistry of acid rock drainage and estimating its ecological impact at a uranium mine in tropical Australia

    International Nuclear Information System (INIS)

    Brown, P.L.; Twining, J.R.; Bennett, J.W.; Comarmond, M.J.

    2000-01-01

    Geochemical kinetic modelling of the effluent chemistry from waste rock dumps at the Rum Jungle copper/uranium mine has been undertaken. The modelling examined the periods both before and after the installation of covers being placed on the dumps. Effluent from the waste rock dump migrates into the adjacent East Branch of the Finniss River and may induce ecological detriment. The model predicts pollutant loads that are significantly greater than that currently observed in the field. The observed reduction of pollutant loads after the cover was placed on the dump is attributed to a decrease in the rate of water infiltration due to the cover placement. It is estimated that a significant increase in pollutant loads is likely to occur Ca. 35 years after remediation. A computer program for ecological risk assessment, AQUARISK, has been developed and applied to evaluate the likelihood of biotic detriment due to exposure to pollutants from the site. Measured and modelled water quality data have been used in AQUARISK, in conjunction with national water quality guidelines and literature derived ecotoxicological data, to estimate the ecological risk for copper, this being a key pollutant. Both the present and past copper concentrations in the East Branch have a 100% risk of exceeding current regulatory criteria in addition to criteria derived from available dose-response data. The predicted increase in copper is unlikely to change these risks. However, the present reduction has led to an appreciable increase in the measured diversity of species at the site (from 8 to 50% implied) as also reflected in the AQUARISK estimate of increased tolerance (from 5 to 36% predicted). Modelled bioavailable copper concentrations will have a deleterious impact on the present degree of recovery and a return to the previous, unacceptably low, system diversity. To achieve a situation where 67% of species are likely to tolerate the effluent from the site, the average target copper concentration

  9. Acid Mine Drainage Potential of the Coral Snake Waste Dump ...

    African Journals Online (AJOL)

    This paper assessed the Acid Mine Drainage (AMD) potential of the Coral Snake Waste Dump located close to the Enkansu and Kaw streams in Obuasi. Ten water and fifty rock samples were analysed for physico-chemical parameters. Acid Base Accounting (ABA) determinations using static methods were employed to ...

  10. Role of hydrous iron oxide formation in attenuation and diel cycling of dissolved trace metals in a stream affected by acid rock drainage

    Science.gov (United States)

    Parker, S.R.; Gammons, C.H.; Jones, Clain A.; Nimick, D.A.

    2007-01-01

    Mining-impacted streams have been shown to undergo diel (24-h) fluctuations in concentrations of major and trace elements. Fisher Creek in south-central Montana, USA receives acid rock drainage (ARD) from natural and mining-related sources. A previous diel field study found substantial changes in dissolved metal concentrations at three sites with differing pH regimes during a 24-h period in August 2002. The current work discusses follow-up field sampling of Fisher Creek as well as field and laboratory experiments that examine in greater detail the underlying processes involved in the observed diel concentration changes. The field experiments employed in-stream chambers that were either transparent or opaque to light, filled with stream water and sediment (cobbles coated with hydrous Fe and Al oxides), and placed in the stream to maintain the same temperature. Three sets of laboratory experiments were performed: (1) equilibration of a Cu(II) and Zn(II) containing solution with Fisher Creek stream sediment at pH 6.9 and different temperatures; (2) titration of Fisher Creek water from pH 3.1 to 7 under four different isothermal conditions; and (3) analysis of the effects of temperature on the interaction of an Fe(II) containing solution with Fisher Creek stream sediment under non-oxidizing conditions. Results of these studies are consistent with a model in which Cu, Fe(II), and to a lesser extent Zn, are adsorbed or co-precipitated with hydrous Fe and Al oxides as the pH of Fisher Creek increases from 5.3 to 7.0. The extent of metal attenuation is strongly temperature-dependent, being more pronounced in warm vs. cold water. Furthermore, the sorption/co-precipitation process is shown to be irreversible; once the Cu, Zn, and Fe(II) are removed from solution in warm water, a decrease in temperature does not release the metals back to the water column. ?? 2006 Springer Science+Business Media B.V.

  11. MODULAR FIELD-BIOREACTOR FOR ACID MINE DRAINAGE TREATMENT

    Science.gov (United States)

    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,...

  12. in remediating acid mine drainage

    African Journals Online (AJOL)

    The management and treatment of contaminated mine water is one of the most urgent problems facing the South African mining industry. The cost advantage of permeable reactive barriers (PRBs) has seen their increased application as means of passively treating mine drainage. A PRB is built by placing a reactive material ...

  13. Natural factors and mining activity bearings on the water quality of the Choapa basin, North Central Chile: insights on the role of mafic volcanic rocks in the buffering of the acid drainage process.

    Science.gov (United States)

    Parra, Amparo; Oyarzún, Jorge; Maturana, Hugo; Kretschmer, Nicole; Meza, Francisco; Oyarzún, Ricardo

    2011-10-01

    This contribution analyzes water chemical data for the Choapa basin, North Central Chile, for the period 1980-2004. The parameters considered are As, Cu Fe, pH, EC, SO₄⁻², Cl⁻¹, and HCO[Formula: see text], from samples taken in nine monitoring stations throughout the basin. Results show rather moderate contents of As, Cu, and Fe, with the exception of the Cuncumén River and the Aucó creek, explained by the influence of the huge porphyry copper deposit of Los Pelambres and by the presence of mining operations, respectively. When compared against results obtained in previous researches at the neighboring Elqui river basin, which host the El Indio Au-Cu-As district, a much reduced grade of pollution is recognized for the Choapa basin. Considering the effect of acid rock drainage (ARD)-related Cu contents on the fine fraction of the sediments of both river basins, the differences recorded are even more striking. Although the Los Pelambres porphyry copper deposit, on the headwaters of the Choapa river basin, is between one and two orders of magnitude bigger than El Indio, stream water and sediments of the former exhibit significantly lower copper contents than those of the latter. A main factor which may explain these results is the smaller degree of H( + )-metasomatism on the host rocks of the Los Pelambres deposit, where mafic andesitic volcanic rocks presenting propylitic hydrothermal alteration are dominant. This fact contrast with the highly altered host rocks of El Indio district, where most of them have lost their potential to neutralize ARD.

  14. GROUNDWATER IMPACTED BY ACID MINE DRAINAGE

    Science.gov (United States)

    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...

  15. Acid mine drainage: mining and water pollution issues in British Columbia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    The importance of protecting water quality and some of the problems associated with mineral development are described. Negative impacts of mining operations such as sedimentation, water disturbances, and water pollution from waste rock and tailings are considered. Mining wastes, types of water pollution from mining, the legacy of acid mine drainage, predicting acid mine drainage, preventing and mitigating acid mine drainage, examples from the past, and cyanide heap-leaching are discussed. The real costs of mining at the Telkwa open pit coal mine are assessed. British Columbia mines that are known for or are potentially acid generating are shown on a map. 32 refs., 10 figs.

  16. Acid drainage (AD) in nature and environmental impact of acid mine drainage (AMD) in Southern Tuscany

    International Nuclear Information System (INIS)

    Di Lella, Luigi Antonello; Protano, Giuseppe; Riccobono, Francesco

    2005-01-01

    Acid drainage (AD) is a natural process occurring locally at the Earth's surface. It consists in a substantial increase of acidity of surface waters as a result of chemical reactions occurring in the atmosphere (i.e. acid rain) or involving reactive phases (i.e. pyrite) present in the percolated medium. Acidic surface waters (usually pH < 4) can be produced by oxidation of sulphides (mainly pyrite and other iron sulphides) exposed to atmospheric oxygen, while human activities, such as mining, can greatly enhance this process. Acid drainage promoted by mining activities is called acid mine drainage (AMD) and is a primary source of environmental pollution and a world-wide problem in both active and abandoned mining areas. In fact, exposure of iron sulphides to oxidising conditions produces strongly acidic drainage waters rich in sulphate and a variety of heavy elements (i.e. As, Cd, Pb, Sb). Several occurrences of active acid mine drainage have been found in the Metalliferous Hills (southern Tuscany). The most important AMD phenomena were observed in the Fenice Capanne and Niccioleta mining areas

  17. Molybdenum and zinc stable isotope variation in mining waste rock drainage and waste rock at the Antamina mine, Peru

    International Nuclear Information System (INIS)

    Skierszkan, E.K.; Mayer, K.U.; Weis, D.; Beckie, R.D.

    2016-01-01

    The stable isotope composition of molybdenum (Mo) and zinc (Zn) in mine wastes at the Antamina Copper–Zn–Mo mine, Peru, was characterized to investigate whether isotopic variation of these elements indicated metal attenuation processes in mine drainage. Waste rock and ore minerals were analyzed to identify the isotopic composition of Mo and Zn sources, namely molybdenites (MoS_2) and sphalerites (ZnS). Molybdenum and Zn stable isotope ratios are reported relative to the NIST-SRM-3134 and PCIGR-1 Zn standards, respectively. δ"9"8Mo among molybdenites ranged from − 0.6 to + 0.6‰ (n = 9) while sphalerites showed no δ"6"6Zn variations (0.11 ± 0.01‰, 2 SD, n = 5). Mine drainage samples from field waste rock weathering experiments were also analyzed to examine the extent of isotopic variability in the dissolved phase. Variations spanned 2.2‰ in δ"9"8Mo (− 0.1 to + 2.1‰) and 0.7‰ in δ"6"6Zn (− 0.4 to + 0.3‰) in mine drainage over a wide pH range (pH 2.2–8.6). Lighter δ"6"6Zn signatures were observed in alkaline pH conditions, which was consistent with Zn adsorption and/or hydrozincite (Zn_5(OH)_6(CO_3)_2) formation. However, in acidic mine drainage Zn isotopic compositions reflected the value of sphalerites. In addition, molybdenum isotope compositions in mine drainage were shifted towards heavier values (0.89 ± 1.25‰, 2 SD, n = 16), with some overlap, in comparison to molybdenites and waste rock (0.13 ± 0.82‰, 2 SD, n = 9). The cause of heavy Mo isotopic signatures in mine drainage was more difficult to resolve due to isotopic heterogeneity among ore minerals and a variety of possible overlapping processes including dissolution, adsorption and secondary mineral precipitation. This study shows that variation in metal isotope ratios are promising indicators of metal attenuation. Future characterization of isotopic fractionation associated to key environmental reactions will improve the power of Mo and Zn isotope ratios to track the fate

  18. Molybdenum and zinc stable isotope variation in mining waste rock drainage and waste rock at the Antamina mine, Peru

    Energy Technology Data Exchange (ETDEWEB)

    Skierszkan, E.K., E-mail: eskiersz@eos.ubc.ca [Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, 2020-2207 Main Mall, Vancouver V6T 1Z4 (Canada); Mayer, K.U. [Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, 2020-2207 Main Mall, Vancouver V6T 1Z4 (Canada); Weis, D. [Pacific Centre for Isotopic and Geochemical Research (PCIGR), Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, 2020-2207 Main Mall, Vancouver V6T 1Z4 (Canada); Beckie, R.D. [Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, 2020-2207 Main Mall, Vancouver V6T 1Z4 (Canada)

    2016-04-15

    The stable isotope composition of molybdenum (Mo) and zinc (Zn) in mine wastes at the Antamina Copper–Zn–Mo mine, Peru, was characterized to investigate whether isotopic variation of these elements indicated metal attenuation processes in mine drainage. Waste rock and ore minerals were analyzed to identify the isotopic composition of Mo and Zn sources, namely molybdenites (MoS{sub 2}) and sphalerites (ZnS). Molybdenum and Zn stable isotope ratios are reported relative to the NIST-SRM-3134 and PCIGR-1 Zn standards, respectively. δ{sup 98}Mo among molybdenites ranged from − 0.6 to + 0.6‰ (n = 9) while sphalerites showed no δ{sup 66}Zn variations (0.11 ± 0.01‰, 2 SD, n = 5). Mine drainage samples from field waste rock weathering experiments were also analyzed to examine the extent of isotopic variability in the dissolved phase. Variations spanned 2.2‰ in δ{sup 98}Mo (− 0.1 to + 2.1‰) and 0.7‰ in δ{sup 66}Zn (− 0.4 to + 0.3‰) in mine drainage over a wide pH range (pH 2.2–8.6). Lighter δ{sup 66}Zn signatures were observed in alkaline pH conditions, which was consistent with Zn adsorption and/or hydrozincite (Zn{sub 5}(OH){sub 6}(CO{sub 3}){sub 2}) formation. However, in acidic mine drainage Zn isotopic compositions reflected the value of sphalerites. In addition, molybdenum isotope compositions in mine drainage were shifted towards heavier values (0.89 ± 1.25‰, 2 SD, n = 16), with some overlap, in comparison to molybdenites and waste rock (0.13 ± 0.82‰, 2 SD, n = 9). The cause of heavy Mo isotopic signatures in mine drainage was more difficult to resolve due to isotopic heterogeneity among ore minerals and a variety of possible overlapping processes including dissolution, adsorption and secondary mineral precipitation. This study shows that variation in metal isotope ratios are promising indicators of metal attenuation. Future characterization of isotopic fractionation associated to key environmental reactions will improve the power

  19. The non-participation of organic sulphur in acid mine drainage generation.

    Science.gov (United States)

    Casagrande, D J; Finkelman, R B; Caruccio, F T

    1989-12-01

    Acid mine drainage is commonly associated with land disturbances that encounter and expose iron sulphides to oxidising atmospheric conditions. The attendant acidic conditions solubilise a host of trace metals. Within this flow regime the potential exists to contaminate surface drinking water supplies with a variety of trace materials. Accordingly, in evaluating the applications for mines located in the headwaters of water sheds, the pre-mining prediction of the occurrence of acid mine drainage is of paramount importance.There is general agreement among investigators that coal organic sulphur is a nonparticipant in acid mine drainage generation; however, there is no scientific documentation to support this concensus. Using simulated weathering, kinetic, mass balance, petrographic analysis and a peroxide oxidation procedure, coal organic sulphur is shown to be a nonparticipant in acid mine drainage generation. Calculations for assessing the acid-generating potential of a sedimentary rock should not include organic sulphur content.

  20. Passive remediation of acid mine drainage using cryptocrystalline magnesite: a batch experimental and geochemical modelling approach

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2015-10-01

    Full Text Available Acid mine drainage is generated when mining activities expose sulphidic rock to water and oxygen leading to generation of sulphuric acid effluents rich in Fe, Al, SO (Sup4) and Mn with minor concentrations of Zn, Cu, Mg, Ca, Pb depending...

  1. CONSTRUCTION OF MODULAR FIELD-BIOREACTOR FOR ACID MINE DRAINAGE TREATMENT

    Science.gov (United States)

    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...

  2. Remediation of Acid Mine Drainage with Sulfate Reducing Bacteria

    Science.gov (United States)

    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…

  3. Copper isotope fractionation in acid mine drainage

    Science.gov (United States)

    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??? 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 resulting from Cu sulfide dissolution should be useful for acid mine drainage

  4. A case study of long-term geochemical evolution of coal waste rock drainage and its remediation

    International Nuclear Information System (INIS)

    Jarvis, A.P.; Gandy, C.J.

    2010-01-01

    The geochemical evolution of drainage from an 35 hectare orphan waste rock pile over a 15-year period was described. Spoil material at the site was generated during coal mining at 2 collieries between 1922 and 1970, and was comprised of grey and black shale, ash, coal, and coal dust. The heap was founded on an impermeable clay layer. Located in northern England, drainage from the rock heap was intercepted by a small compost wetland system installed in 1997. The waste rock heap was selectively capped in 1998. Water samples were collected and analyzed. Anion concentrations were determined using an ion chromatograph. The samples were filtered periodically. Acidity concentrations and flow rates were determined. Results of the study showed measurable improvements in water quality as a result of capping the heap. The study demonstrated that a combination of selective spoil capping and wetland treatment can serve as a low-cost solution to acid mine drainage at some abandoned mine sites. 9 refs., 1 tab., 1 fig.

  5. A case study of long-term geochemical evolution of coal waste rock drainage and its remediation

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, A.P.; Gandy, C.J. [Newcastle Univ. (United Kingdom). School of Civil Engineering and Geosciences, Hydrogeochemical Engineering Research and Outreach Group

    2010-07-01

    The geochemical evolution of drainage from an 35 hectare orphan waste rock pile over a 15-year period was described. Spoil material at the site was generated during coal mining at 2 collieries between 1922 and 1970, and was comprised of grey and black shale, ash, coal, and coal dust. The heap was founded on an impermeable clay layer. Located in northern England, drainage from the rock heap was intercepted by a small compost wetland system installed in 1997. The waste rock heap was selectively capped in 1998. Water samples were collected and analyzed. Anion concentrations were determined using an ion chromatograph. The samples were filtered periodically. Acidity concentrations and flow rates were determined. Results of the study showed measurable improvements in water quality as a result of capping the heap. The study demonstrated that a combination of selective spoil capping and wetland treatment can serve as a low-cost solution to acid mine drainage at some abandoned mine sites. 9 refs., 1 tab., 1 fig.

  6. Acid mine drainage as an important mechanism of natural radiation enhancement in mining areas

    International Nuclear Information System (INIS)

    Fernandes, H.M.; Franklin, M.R.

    2002-01-01

    Acid mine drainage (AMD) is a world wide problem that occurs whenever sulfidic material is present in association to the mined ore. The acidic waters generated by the process of sulfide minerals oxidation can mobilize important amounts of pollutants and cause significant environmental impacts. The composition of the drainage will depend, on a very large extent, on the mineralogy of the rocks. The purpose of this paper is to demonstrate that acid mine drainage has the potential to enhance the natural levels of environmental radioactivity. The paper revises some strategies to be used in the diagnostic of the problem. General mathematical formulations that can assist on the prediction of the duration of the problem, and the definition of the size of the oxidizing zones in a waste dump are given. A study case on a waste dump of the Pocos de Caldas Uranium Mining Site, Brazil is also presented. (author)

  7. The Role of Geochemical Modeling in Predicting Quality Evolution of Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Andrea Šlesárová

    2004-12-01

    Full Text Available In recent years the massive reduction of raw materials production brings a wide scale of problems. Among the most frequent exposes of mining activities belong besides old spoil heaps and sludge lagoons, also the drainage of acidic and highly mineralized mine waters known as “the Acid Mine Drainage” (thereinafter AMD from old mine workings. The acid mine drainage presents to the surrounding environment a massive problem. These waters are toxic to the plant and animal life, including fishes and aquatic insects. The primary control of the drainage pH and the metal content is the exposure of sulphide minerals to weathering, the availability of atmospheric oxygen, and the sensitivity of non-sulphide minerals to buffer acidity. A geochemical modeling software is increasingly used to solve evolution of the complex chemical systems such as the interaction of acid mine drainage with wall rocks, migration of AMD components. Beyond the better computer facilities it allows to study of thermodynamic properties substances and to enlarge thermodynamic databases. A model is a simplified version of reality based on its observation and experiments. A goal of the modeling process is the tendency to better understand processes taking place inside of the system, the attempt to assume the system’s behaviour in the future or to predict the effect of changed conditions in the system’s environment on the system itself.

  8. Techniques to correct and prevent acid mine drainage: A review

    OpenAIRE

    Pozo-Antonio, Santiago; Puente-Luna, Iván; Lagüela-López, Susana; Veiga-Ríos, María

    2014-01-01

    Acid mine drainage (AMD) from mining wastes is one of the current environmental problems in the field of mining pollution that requires most action measures. This term describes the drainage generated by natural oxidation of sulfide minerals when they are exposed to the combined action of water and atmospheric oxygen. AMD is characterized by acidic effluents with a high content of sulfate and heavy metal ions in solution, which can contaminate both groundwater and surface water. Minerals resp...

  9. Use of Natural and Applied Tracers to Guide Targeted Remediation Efforts in an Acid Mine Drainage System, Colorado Rockies, USA

    OpenAIRE

    Cowie, Rory; Williams, Mark; Wireman, Mike; Runkel, Robert

    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. ...

  10. Evaluating the Acid Mine Drainage Potential at Abosso Goldfields ...

    African Journals Online (AJOL)

    Evaluation of the potential for acid generation is therefore very important in any mine setting where sulphide minerals exist. Results of two Acid-Base Accounting (ABA) studies conducted at Abosso Goldfields Limited (AGL) on 120 rock and tailings samples reveal that on average, total sulphide values in rocks are low, with ...

  11. Acidity and alkalinity in mine drainage: Theoretical considerations

    Science.gov (United States)

    Kirby, Carl S.; Cravotta,, Charles A.

    2004-01-01

    Acidity, net acidity, and net alkalinity are widely used parameters for the characterization of mine drainage, but these terms are not well defined and are often misunderstood. Incorrect interpretation of acidity, alkalinity, and derivative terms can lead to inadequate treatment design or poor regulatory decisions. We briefly explain derivations of theoretical expressions of three types of alkalinities (caustic, phenolphthalein, and total) and acidities (mineral, CO2, and total). Theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined “CO2- acidity” is closely related to most standard titration methods used for mine drainage with an endpoint pH of 8.3, but it presents numerous interpretation problems, and it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/massaction approach and employing graphs for visualization, we explore the concept of principal components and how to assign acidity contributions to solution species, including aqueous complexes, commonly found in mine drainage. We define a comprehensive theoretical definition of acidity in mine drainage on the basis of aqueous speciation at the sample pH and the capacity of these species to undergo hydrolysis to pH 8.3. This definition indicates the computed acidity in milligrams per liter (mg L-1 ) as CaCO3 (based on pH and analytical concentrations of dissolved FeIII , FeII , Mn, and Al in mg L-1 ): Aciditycomputed = 50. (10(3-pH) + 3.CFeIII/55.8 + 2.CFeII/55.8 + 2.CMn/54.9 + 3.CAl/27.0) underestimates contributions from HSO4 - and H+ , but overestimates the acidity due to Fe3+. These errors tend to approximately cancel each other. We demonstrate that “net alkalinity” is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. We demonstrate that, for most mine-drainage solutions, a

  12. HANDBOOK FOR CONSTRUCTED WETLANDS RECEIVING ACID MINE DRAINAGE

    Science.gov (United States)

    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...

  13. Sulfate Reduction at Low Ph To Remediate Acid Mine Drainage

    NARCIS (Netherlands)

    Sánchez-Andrea, I.; Sanz, J.L.; Bijmans, M.F.M.; Stams, A.J.M.

    2014-01-01

    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,

  14. Induced Polarization Surveying for Acid Rock Screening in Highway Design

    Science.gov (United States)

    Butler, K. E.; Al, T.; Bishop, T.

    2004-05-01

    Highway and pipeline construction agencies have become increasingly vigilant in their efforts to avoid cutting through sulphide-bearing bedrock that has potential to produce acid rock drainage. Blasting and fragmentation of such rock increases the surface area available for sulphide oxidation and hence increases the risk of acid rock drainage unless the rock contains enough natural buffering capacity to neutralize the pH. In December, 2001, the New Brunswick Department of Transportation (NBOT) sponsored a field trial of geophysical surveying in order to assess its suitability as a screening tool for locating near-surface sulphides along proposed highway alignments. The goal was to develop a protocol that would allow existing programs of drilling and geochemical testing to be targeted more effectively, and provide design engineers with the information needed to reduce rock cuts where necessary and dispose of blasted material in a responsible fashion. Induced polarization (IP) was chosen as the primary geophysical method given its ability to detect low-grade disseminated mineralization. The survey was conducted in dipole-dipole mode using an exploration-style time domain IP system, dipoles 8 to 25 m in length, and six potential dipoles for each current dipole location (i.e. n = 1 - 6). Supplementary information was provided by resistivity and VLF-EM surveys sensitive to lateral changes in electrical conductivity, and by magnetic field surveying chosen for its sensitivity to the magnetic susceptibility of pyrrhotite. Geological and geochemical analyses of samples taken from several IP anomalies located along 4.3 line-km of proposed highway confirmed the effectiveness of the screening technique. IP pseudosections from a region of metamorphosed shales and volcaniclastic rocks identified discrete, well-defined mineralized zones. Stronger, overlapping, and more laterally extensive IP anomalies were observed over a section of graphitic and sulphide-bearing metasedimentary

  15. Origin of acid mine drainage in Enugu

    International Nuclear Information System (INIS)

    Uma, K.O.

    1992-01-01

    Mine flooding is a serious problem in the Enugu Coal Mines and has led to the abandonment of two of the four mines. About 1800 m 3 of water is pumped out daily from the mines into the nearby streams. The source of this enormous volume of water has been established based on the hydrodynamics and hydrology of the area. Two prolific aquifers - an unconfined and a confined system - overlie the mines, but the mine water is derived principally from the unconfined aquifer. The pathway of flow is, provided by the numerous fractures connecting the two aquifers and the mine tunnel. The major hydrochemical activity resulting in pollution of the mine water occurs within the sumps in the floor of the longwalls. These sumps act as oxidation chambers where groundwater from the fractures mixes and subsequently reacts with sulfur-rich solutes released by coal mining. Contrary to general belief, the mine drainage has not seriously degraded the chemistry of receiving streams. The pH and electric conductivity, representing, the dissolved ions, were increased less than 10% of the values in the unaffected region

  16. Allegheny woodrat (Neotoma magister) use of rock drainage channels on reclaimed mines in southern West Virginia

    Science.gov (United States)

    Chamblin, H.D.; Wood, P.B.; Edwards, J.W.

    2004-01-01

    Allegheny woodrats (Neotoma magister) currently receive protected status throughout their range due to population declines. Threats associated with habitat fragmentation (e.g., introduced predators, disease, loss of connectivity among subpopulations and habitat loss) may explain why Allegheny woodrats are no longer found in many areas where they existed just 25 y ago. In southern West Virginia, surface coal mining is a major cause of forest fragmentation. Furthermore, mountaintop mining, the prevalent method in the region, results in a loss of rock outcrops and cliffs within forested areas, typical habitat of the Allegheny woodrat To determine the extent that Allegheny woodrats make use of reclaimed mine land, particularly rock drainages built during reclamation, we sampled 24 drainage channels on reclaimed surface mines in southern West Virginia, collected habitat data at each site and used logistic regression to identify habitat variables related to Allegheny woodrat presence. During 187 trap nights, 13 adult, 2 subadult and 8 juvenile Allegheny woodrats were captured at 13 of the 24 sites. Percent of rock as a groundcover and density of stems >15 cm diameter-at-breast-height (DBH) were related to Allegheny woodrat presence and were significantly greater at sites where Allegheny woodrats were present than absent. Sites where Allegheny woodrats were present differed substantially from other described habitats in West Virginia, though they may simulate boulder piles that occur naturally. Our findings suggest the need for additional research to examine the dynamics between Allegheny woodrat populations inhabiting rock outcrops in forests adjacent to mines and populations inhabiting constructed drainage channels on reclaimed mines. However, if Allegheny woodrats can use human-created habitat, our results will be useful to surface mine reclamation and to other mitigation efforts where rocky habitats are lost or disturbed.

  17. Bioremediation of acid mine drainage using algae strains: A review

    Directory of Open Access Journals (Sweden)

    J.K. Bwapwa

    2017-12-01

    Full Text Available Acid mine drainage (AMD causes massive environmental concerns worldwide. It is highly acidic and contains high levels of heavy metals causing environmental damage. Conventional treatment methods may not be effective for AMD. The need for environmental remediation requires cost effective technologies for efficient removal of heavy metals. In this study, algae based systems were reviewed and analyzed to point out the potentials and gaps for future studies. Algae strains such as Spirulina sp., Chlorella, Scenedesmus, Cladophora, Oscillatoria, Anabaena, Phaeodactylum tricornutum have showed the capacity to remove a considerable volume of heavy metals from AMD. They act as “hyper-accumulators” and “hyper-adsorbents” with a high selectivity for different elements. In addition, they generate high alkalinity which is essential for precipitation of heavy metals during treatment. However, algae based methods of abating AMD are not the ultimate solution to the problem and there is room for more studies. : The bioremediation of acid mine drainage is achievable with the use of microalgae. Keywords: Acid mine drainage, Algae strains, Contamination, Heavy metals, Bioremediation

  18. Behaviour of U-Isotopes in an Estuary Affected by Acid Mine Drainage and Industrial Releases

    International Nuclear Information System (INIS)

    Hierro, A.; Bolivar, J.P.; Vaca, F.

    2011-01-01

    Tinto and Odiel rivers (SW of Spain) is an ecosystem of great interest that is seriously affected by acid mine drainage (AMD) from long-term mining activities (pH < 3). Additionally, a large industrial complex is located in the surroundings of this estuary and Huelva town, which includes two phosphate rock processing plants that produce about 3 millions of tons per year of a byproduct called phosphogypsum (PG) containing high U-series radionuclides concentrations. For these reasons, the estuary of Huelva is one of the most heavy metals and radionuclides polluted estuarine systems in Europe with extremely low pH.

  19. Riffle zoobenthos in streams receiving acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Koryak, M; Shapiro, M A; Sykora, J L

    1972-01-01

    The bottom fauna of a stream polluted by acid mine drainage, was studied, using the standard methods of sample collecting. In localities immediately influenced by mine drainage, where very low pH values and high acidities prevail, the effect of acid mine wastes on the ecology and composition of the benthic fauna is, in general, similar to the effect of organic pollution. In these areas we found high numbers of individuals comprised of a few species. In the zones of active neutralization, where iron hydroxides are deposited, species diversity slightly increases but the biomass is very low. The most numerous invertebrates in the stream sections exhibiting high acidity and low pH are midge larvae, especially Tendipes gr. riparius. The number of insect groups present increases steadily with progressive neutralization until crustacea (amphipoda) and oligochaeta appear, indicating considerable improvement in water quality. The supply of desirable benthic fish food (Tendipes ssp.) is very high in the parts of the stream where low pH, high acidity, and high ferrous iron concentrations prevail. Unfortunately, fish cannot survive under these conditions to utilize this abundant food supply. On the other hand, in the less acidic zones, where fish could possibly survive, the deposition of ferric iron drastically diminishes the total biomass of benthic organisms and therefore severely limits fish populations.

  20. Proceedings of the international land reclamation and mine drainage conference and third international conference on the abatement of acidic drainage. Volume 1: Mine drainage -- SP 06A-94

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Volume 1 of these proceedings is divided into the following sections: Modeling mine water quality; Water treatment with wetlands; Predicting mine water quality; Water treatment--Chemical; Control of acid mine drainage--Wet covers; Site characterization monitoring; Control of acid mine drainage--Alkaline addition; and Mine water geochemistry. Papers dealing with or applicable to coal or uranium mining have been processed separately for inclusion on the data base

  1. Ochre precipitates and Acid Mine Drainage in a mine environment

    Czech Academy of Sciences Publication Activity Database

    Máša, B.; Pulišová, Petra; Bezdička, Petr; Michalková, E.; Šubrt, Jan

    2012-01-01

    Roč. 56, č. 1 (2012), s. 9-14 ISSN 0862-5468 R&D Projects: GA MŠk(CZ) MEB0810136 Grant - others:Ministry of Education of the Slovak Republic(SK) VEGA 1/0529/09 Institutional research plan: CEZ:AV0Z40320502 Keywords : ochre precipitate * Acid Mine Drainage (AMD) * X-ray diffraction analysis (XRD) * Scanning electron microscopy (SEM) * specific surface area and porosity Subject RIV: CA - Inorganic Chemistry Impact factor: 0.418, year: 2012

  2. Imaging Preferential Flow Pathways of Contaminants from Passive Acid Mine Drainage Mitigation Sites Using Electrical Resistivity

    Science.gov (United States)

    Kelley, N.; Mount, G.; Terry, N.; Herndon, E.; Singer, D. M.

    2017-12-01

    The Critical Zone represents the surficial and shallow layer of rock, air, water, and soil where most interactions between living organisms and the Earth occur. Acid mine drainage (AMD) resulting from coal extraction can influence both biological and geochemical processes across this zone. Conservative estimates suggest that more than 300 million gallons of AMD are released daily, making this acidic solution of water and contaminants a common issue in areas with legacy or current coal extraction. Electrical resistivity imaging (ERI) provides a rapid and minimally invasive method to identify and monitor contaminant pathways from AMD remediation systems in the subsurface of the Critical Zone. The technique yields spatially continuous data of subsurface resistivity that can be inverted to determine electrical conductivity as a function of depth. Since elevated concentrations of heavy metals can directly influence soil conductivity, ERI data can be used to trace the flow pathways or perhaps unknown mine conduits and transport of heavy metals through the subsurface near acid mine drainage sources. This study aims to examine preferential contaminant migration from those sources through substrate pores, fractures, and shallow mine workings in the near subsurface surrounding AMD sites in eastern Ohio and western Pennsylvania. We utilize time lapse ERI measures during different hydrologic conditions to better understand the variability of preferential flow pathways in relation to changes in stage and discharge within the remediation systems. To confirm ERI findings, and provide constraint to geochemical reactions occurring in the shallow subsurface, we conducted Inductively Coupled Plasma (ICP) spectrometry analysis of groundwater samples from boreholes along the survey transects. Through these combined methods, we can provide insight into the ability of engineered systems to contain and isolate metals in passive acid mine drainage treatment systems.

  3. [Microeukaryotic biodiversity in the waste ore samples surrounding an acid mine drainage lake].

    Science.gov (United States)

    Li, Si-Yuan; Hao, Chun-Bo; Wang, Li-Hua; Lü, Zheng; Zhang, Li-Na; Liu, Ying; Feng, Chuan-Ping

    2013-10-01

    The abandoned mineral samples were collected in an acid mine drainage area in Anhui Province. Molecular ecological methods were used to construct 18S rDNA clone libraries after analyzing the main physicochemical parameters, and then the microeukaryotic diversity and community structure in the acid mine drainage area were studied. The results showed that the region was strongly acidic (pH <3), and the concentrations of Fe, SO2-(4), P, NO-(3) -N showed the same trend, all higher in the bare waste ore samples PD and 1 M than in the vegetation covered samples LW and XC. Four eukaryotic phyla were detected in the abandoned mineral samples: Ascomycota, Basidiomycota, Glomeromycota and Arthropoda. Glomeromycota can form an absolute symbiotic relationship with the plant, and it was a key factor for early plant to adapt the terrestrial environment. The biodiversity of the vegetation covered samples LW and XC, which contained Glomeromycota, was much higher than that of the bare abandoned rock samples PD and 1 M. Moreover, many sequences in the libraries were closely related to some isolated strains, which are tolerant to low pH and heavy metals, such as Penicillium purpurogenum, Chaetothyriales sp. and Staninwardia suttonii.

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. A novel approach for acid mine drainage pollution biomonitoring using rare earth elements bioaccumulated in the freshwater clam Corbicula fluminea.

    Science.gov (United States)

    Bonnail, Estefanía; Pérez-López, Rafael; Sarmiento, Aguasanta M; Nieto, José Miguel; DelValls, T Ángel

    2017-09-15

    Lanthanide series have been used as a record of the water-rock interaction and work as a tool for identifying impacts of acid mine drainage (lixiviate residue derived from sulphide oxidation). The application of North-American Shale Composite-normalized rare earth elements patterns to these minority elements allows determining the origin of the contamination. In the current study, geochemical patterns were applied to rare earth elements bioaccumulated in the soft tissue of the freshwater clam Corbicula fluminea after exposure to different acid mine drainage contaminated environments. Results show significant bioaccumulation of rare earth elements in soft tissue of the clam after 14 days of exposure to acid mine drainage contaminated sediment (ΣREE=1.3-8μg/gdw). Furthermore, it was possible to biomonitor different degrees of contamination based on rare earth elements in tissue. The pattern of this type of contamination describes a particular curve characterized by an enrichment in the middle rare earth elements; a homologous pattern (E MREE =0.90) has also been observed when applied NASC normalization in clam tissues. Results of lanthanides found in clams were contrasted with the paucity of toxicity studies, determining risk caused by light rare earth elements in the Odiel River close to the Estuary. The current study purposes the use of clam as an innovative "bio-tool" for the biogeochemical monitoring of pollution inputs that determines the acid mine drainage networks affection. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Geochemistry of acid mine drainage from a coal mining area and processes controlling metal attenuation in stream waters, southern Brazil

    Directory of Open Access Journals (Sweden)

    VERIDIANA P. CAMPANER

    2014-06-01

    Full Text Available Acid drainage influence on the water and sediment quality was investigated in a coal mining area (southern Brazil. Mine drainage showed pH between 3.2 and 4.6 and elevated concentrations of sulfate, As and metals, of which, Fe, Mn and Zn exceeded the limits for the emission of effluents stated in the Brazilian legislation. Arsenic also exceeded the limit, but only slightly. Groundwater monitoring wells from active mines and tailings piles showed pH interval and chemical concentrations similar to those of mine drainage. However, the river and ground water samples of municipal public water supplies revealed a pH range from 7.2 to 7.5 and low chemical concentrations, although Cd concentration slightly exceeded the limit adopted by Brazilian legislation for groundwater. In general, surface waters showed large pH range (6 to 10.8, and changes caused by acid drainage in the chemical composition of these waters were not very significant. Locally, acid drainage seemed to have dissolved carbonate rocks present in the local stratigraphic sequence, attenuating the dispersion of metals and As. Stream sediments presented anomalies of these elements, which were strongly dependent on the proximity of tailings piles and abandoned mines. We found that precipitation processes in sediments and the dilution of dissolved phases were responsible for the attenuation of the concentrations of the metals and As in the acid drainage and river water mixing zone. In general, a larger influence of mining activities on the chemical composition of the surface waters and sediments was observed when enrichment factors in relation to regional background levels were used.

  7. Geochemistry of acid mine drainage from a coal mining area and processes controlling metal attenuation in stream waters, southern Brazil.

    Science.gov (United States)

    Campaner, Veridiana P; Luiz-Silva, Wanilson; Machado, Wilson

    2014-05-14

    Acid drainage influence on the water and sediment quality was investigated in a coal mining area (southern Brazil). Mine drainage showed pH between 3.2 and 4.6 and elevated concentrations of sulfate, As and metals, of which, Fe, Mn and Zn exceeded the limits for the emission of effluents stated in the Brazilian legislation. Arsenic also exceeded the limit, but only slightly. Groundwater monitoring wells from active mines and tailings piles showed pH interval and chemical concentrations similar to those of mine drainage. However, the river and ground water samples of municipal public water supplies revealed a pH range from 7.2 to 7.5 and low chemical concentrations, although Cd concentration slightly exceeded the limit adopted by Brazilian legislation for groundwater. In general, surface waters showed large pH range (6 to 10.8), and changes caused by acid drainage in the chemical composition of these waters were not very significant. Locally, acid drainage seemed to have dissolved carbonate rocks present in the local stratigraphic sequence, attenuating the dispersion of metals and As. Stream sediments presented anomalies of these elements, which were strongly dependent on the proximity of tailings piles and abandoned mines. We found that precipitation processes in sediments and the dilution of dissolved phases were responsible for the attenuation of the concentrations of the metals and As in the acid drainage and river water mixing zone. In general, a larger influence of mining activities on the chemical composition of the surface waters and sediments was observed when enrichment factors in relation to regional background levels were used.

  8. Acid mine drainage biogeochemistry at Iron Mountain, California

    Directory of Open Access Journals (Sweden)

    Gihring Thomas M

    2004-06-01

    Full Text Available 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 (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 which

  9. Evolution of Acid Mine Drainage Formation in Sulphidic Mine Tailings

    Directory of Open Access Journals (Sweden)

    Bernhard Dold

    2014-07-01

    Full Text Available Sulphidic mine tailings are among the largest mining wastes on Earth and are prone to produce acid mine drainage (AMD. The formation of AMD is a sequence of complex biogeochemical and mineral dissolution processes. It can be classified in three main steps occurring from the operational phase of a tailings impoundment until the final appearance of AMD after operations ceased: (1 During the operational phase of a tailings impoundment the pH-Eh regime is normally alkaline to neutral and reducing (water-saturated. Associated environmental problems include the presence of high sulphate concentrations due to dissolution of gypsum-anhydrite, and/or effluents enriched in elements such as Mo and As, which desorbed from primary ferric hydroxides during the alkaline flotation process. (2 Once mining-related operations of the tailings impoundment has ceased, sulphide oxidation starts, resulting in the formation of an acidic oxidation zone and a ferrous iron-rich plume below the oxidation front, that re-oxidises once it surfaces, producing the first visible sign of AMD, i.e., the precipitation of ferrihydrite and concomitant acidification. (3 Consumption of the (reactive neutralization potential of the gangue minerals and subsequent outflow of acidic, heavy metal-rich leachates from the tailings is the final step in the evolution of an AMD system. The formation of multi-colour efflorescent salts can be a visible sign of this stage.

  10. Treatment of the acid mine drainage residue for uranium recovery

    International Nuclear Information System (INIS)

    Dias, M.M.; Horta, D.G.; Fukuma, H.T.; Villegas, R.A.S.; Carvalho, C.H.T. de; Silva, A.C. da

    2017-01-01

    Acid mine drainage (AMD) is a process that occurs in many mining that have sulfide ores. With water and oxygen, several metals are oxidized, one example being uranium. At the mine pit of the Osamu Utsumi Mine located at INB - Caldas and in two other boot-wastes (mining waste pile), AMD is present and currently, without a technological solution. The acidic water present in the pit is treated with hydrated lime, generating water for disposal and an alkaline residue called calcium diuranate - DUCA. The DUCA has a concentration of approximately 0.32% U 3 O 8 , which makes interesting the development of a process for extracting that metal. One of the processes that can be used is leaching. For this study, it was decided to evaluate the alkaline leaching to extract the uranium present in the residue. It is necessary to optimize operational parameters for the process: percentage of solids, concentration of leaching agent in solution, temperature and reaction time. With these parameters, it is possible to improve the leaching so that the largest amount of uranium is extracted from the sample, to help solve the environmental impact caused by the wastewater from the treatment of acid waters and, in addition, to give an economical destination for this metal that is contained in the deposited DUCA

  11. Major hydrogeochemical processes in an Acid Mine Drainage affected estuary

    International Nuclear Information System (INIS)

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

    2015-01-01

    Highlights: • Mixing of acid riverine water with alkaline seawater was studied in an estuary. • Combination of data and geochemical tools allowed modeling the water mixing. • The main geochemical processes were identified and for the first time quantified. • Water chemistry is the result of mixing, dissolution-precipitation and sorption. • Main reactions: gypsum and calcite dissolution and Al and Fe solids precipitation. - Abstract: 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)

  12. Bacteria and Acidic Drainage from Coal Refuse: Inhibition by Sodium Lauryl Sulfate and Sodium Benzoate

    OpenAIRE

    Dugan, Patrick R.; Apel, William A.

    1983-01-01

    The application of an aqueous solution of sodium lauryl sulfate and sodium benzoate to the surface of high-sulfur coal refuse resulted in the inhibition of iron-and sulfur-oxidizing chemoautotrophic bacteria and in the decrease of acidic drainage from the refuse, suggesting that acid drainage can be abated in the field by inhibiting iron- and sulfur-oxidizing bacteria.

  13. 40 CFR Appendix A to Part 434 - Alternate Storm Limitations for Acid or Ferruginous Mine Drainage

    Science.gov (United States)

    2010-07-01

    ... Storm Limitations for Acid or Ferruginous Mine Drainage EC01MY92.113 ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Alternate Storm Limitations for Acid or Ferruginous Mine Drainage A Appendix A to Part 434 Protection of Environment ENVIRONMENTAL...

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

    Science.gov (United States)

    Jin, Song [Fort Collins, CO; Fallgren, Paul H [Laramie, WY; Morris, Jeffrey M [Laramie, WY

    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.

  15. Integrated treatment of acid mine drainage using cryptocrystalline magnesite and barium chloride

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2017-08-01

    Full Text Available This study endeavours to report the efficiency of a hybrid approach in the treatment of acid mine drainage. Cryptocrystalline magnesite was used to pre-treat acid mine drainage and barium chloride was used to remove the residual sulphate through...

  16. Efficiency of ball milled South African bentonite clay for remediation of acid mine drainage

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2015-12-01

    Full Text Available The feasibility of using vibratory ball milled South African bentonite clay for neutralization and attenuation of inorganic contaminants from acidic and metalliferous mine effluents has been evaluated. Treatment of acid mine drainage (AMD...

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

    Science.gov (United States)

    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). Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Copper removal from acid mine drainage-polluted water using glutaraldehyde-polyethyleneimine modified diatomaceous earth particles

    Directory of Open Access Journals (Sweden)

    Mikael Larsson

    2018-02-01

    Full Text Available Mine waters and tailings generated from mining and mineral processing activities often have detrimental impact on the local environment. One example is acid mine drainage, in which sulphides in the mining waste react with water and oxygen to produce an acidic environment that subsequently dissolves host rock minerals from the waste containing toxic metals and trace elements. Copper is one such metal of significance, as it is mined at large volumes in sulphide containing ores. It has strong biocidal activity that greatly affects ecosystems. We have previously reported that glutaraldehyde (GA-crosslinked polyethyleneimine (PEI has strong affinity and selectivity for copper and that diatomaceous earth (DE particles can be modified with the material to form a copper-extraction resin. In this study, the copper uptake of GA-PEI-DE particles was investigated from synthetic and real acid mine drainage samples under different pHs and their copper removal performance was compared with that of selected commercial resins. The results revealed that copper could effectively and preferentially bind to the material at pH 4, and that the copper could be completely eluted by lowering of the pH. In addition, effective copper uptake and elution was demonstrated using real legacy acid mine drainage water from Mount Lyell in Tasmania.

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

    Science.gov (United States)

    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.

  20. Effectiveness of a constructed wetland for acid mine drainage reclamation

    International Nuclear Information System (INIS)

    Grant, A.J.; Ramey, B.A.; Jarrett, L.; Hart, G.

    1993-01-01

    Acid mine drainage (AMD) from an abandoned coal mine in southcentral Kentucky had pH levels as low as 2.5 and iron concentrations as high as 630 mg/L. In the summer of 1992, the SCS constructed a wetland system to treat the AMD that involved use of both physical and biological treatment. The AMD was fed into three anoxic limestone beds, followed by an aeration pond, before entering a series of four cattail cells and a polishing pond. Flow of AMD was initiated in the fall of 1992, and chemical and biological monitoring were conducted throughout the winter months. Chemical analysis of the water along the flow path of the AMD during the first six months of operation indicated that the limestone beds improved the pH substantially, and that most of the metals were removed prior to the water entering the cattail cells. The effectiveness of the wetland system to improve water quality also was monitored using the cladoceran (Ceriodaphnia dubia) survival and reproduction test. Determination of toxic levels indicated a substantial improvement in water quality below the limestone beds, and a slight decrease in toxicity throughout the cattail cells. However, toxic levels stayed the same or increased in the polishing pond. Water quality monitoring will continue through the growing season of 1993 to assess the impact of plant growth on the reclamation of the AMD

  1. Iron removal from acid mine drainage by wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Sexstone, A.J.; Skousen, J.G.; Calabrese, J.; Bhumbla, D.K.; Cliff, J.; Sencindiver, J.C.; Bissonnette, G.K.

    1999-07-01

    Neutralization of acid mine drainage (AMD) in man-made cattail (Typha) wetlands was investigated over a four-year period utilizing experimental models constructed in a greenhouse. A naturally occurring AMD (430 mg/L Fe, 5 mg/L Mn, 2,900 mg/L sulfate, pH 2.75) was collected in the field and added to the greenhouse wetlands at 60.5 L/day. Monthly water samples from four depths (10, 20, 30, and 40 cm) were obtained from the influent, midpoint, and effluent locations of the wetland. During the first year of AMD treatment, near neutral pH (6.5) and anoxic conditions ({minus}300 mV) were observed in subsurface sediments of wetlands. The wetlands retained an estimated 65% of the total applied iron in the first year, primarily in the exchangeable, organically bound, and oxide form. During later years, 20 to 30% of the influent iron was retained predominantly as precipitated oxides. Iron sulfides resulting form sulfate reduction accounted for less than 5% of the iron retained, and were recovered primarily as monosulfides during the first year and as disulfides in the fourth year. Improvement in effluent pH was primarily attributed to limestone dissolution in the anaerobic subsurface sediments, which decreased with time. Constructed wetlands exhibit finite lives for effective AMD treatment and provisions should be made for their periodic rejuvenation or replacement.

  2. Horizontal gene transfer in an acid mine drainage microbial community.

    Science.gov (United States)

    Guo, Jiangtao; Wang, Qi; Wang, Xiaoqi; Wang, Fumeng; Yao, Jinxian; Zhu, Huaiqiu

    2015-07-04

    Horizontal gene transfer (HGT) has been widely identified in complete prokaryotic genomes. However, the roles of HGT among members of a microbial community and in evolution remain largely unknown. With the emergence of metagenomics, it is nontrivial to investigate such horizontal flow of genetic materials among members in a microbial community from the natural environment. Because of the lack of suitable methods for metagenomics gene transfer detection, microorganisms from a low-complexity community acid mine drainage (AMD) with near-complete genomes were used to detect possible gene transfer events and suggest the biological significance. Using the annotation of coding regions by the current tools, a phylogenetic approach, and an approximately unbiased test, we found that HGTs in AMD organisms are not rare, and we predicted 119 putative transferred genes. Among them, 14 HGT events were determined to be transfer events among the AMD members. Further analysis of the 14 transferred genes revealed that the HGT events affected the functional evolution of archaea or bacteria in AMD, and it probably shaped the community structure, such as the dominance of G-plasma in archaea in AMD through HGT. Our study provides a novel insight into HGT events among microorganisms in natural communities. The interconnectedness between HGT and community evolution is essential to understand microbial community formation and development.

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

    Directory of Open Access Journals (Sweden)

    Celia eMendez-Garcia

    2015-05-01

    Full Text Available 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 technologies 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 ultra-micro-archaea demand their inclusion in the microbial characterisation of AMD systems. In this review, we present a complete overview of the bacterial, archaeal (including ultra-micro-archaeal 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.

  4. Membrane technology applied to acid mine drainage from copper mining.

    Science.gov (United States)

    Ambiado, K; Bustos, C; Schwarz, A; Bórquez, R

    2017-02-01

    The objective of this study is to evaluate the treatment of high-strength acid mine drainage (AMD) from copper mining by nanofiltration (NF) and reverse osmosis (RO) at pilot scale. The performances of two commercial spiral-wound membranes - NF99 and RO98pHt, both from Alfa Laval - were compared. The effects of pressure and feed flow on ion rejection and permeate flux were evaluated. The results showed high ion removal under optimum pressure conditions, which reached 92% for the NF99 membrane and 98% for the RO98pHt membrane. Sulfate removal reached 97% and 99% for NF99 and RO98pHt, respectively. In the case of copper, aluminum, iron and manganese, the removal percentage surpassed 95% in both membranes. Although concentration polarization limited NF performance at higher pressures, permeate fluxes observed in NF were five times greater than those obtained by RO, with only slightly lower divalent ion rejection rates, making it a promising option for the treatment of AMD.

  5. Challenges in recovering resources from acid mine drainage

    Science.gov (United States)

    Nordstrom, D. Kirk; Bowell, Robert J.; Campbell, Kate M.; Alpers, Charles N.

    2017-01-01

    Metal recovery from mine waters and effluents is not a new approach but one that has occurred largely opportunistically over the last four millennia. Due to the need for low-cost resources and increasingly stringent environmental conditions, mine waters are being considered in a fresh light with a designed, deliberate approach to resource recovery often as part of a larger water treatment evaluation. Mine water chemistry is highly dependent on many factors including geology, ore deposit composition and mineralogy, mining methods, climate, site hydrology, and others. Mine waters are typically Ca-Mg-SO4±Al±Fe with a broad range in pH and metal content. The main issue in recovering components of these waters having potential economic value, such as base metals or rare earth elements, is the separation of these from more reactive metals such as Fe and Al. Broad categories of methods for separating and extracting substances from acidic mine drainage are chemical and biological. Chemical methods include solution, physicochemical, and electrochemical technologies. Advances in membrane techniques such as reverse osmosis have been substantial and the technique is both physical and chemical. Biological methods may be further divided into microbiological and macrobiological, but only the former is considered here as a recovery method, as the latter is typically used as a passive form of water treatment.

  6. The use of hydrated lime in acid mine drainage treatment

    Science.gov (United States)

    Othman, Anuar; Sulaiman, Azli; Sulaiman, Shamsul Kamal

    2017-05-01

    Hydrated lime also known as calcium hydroxide with chemical formula Ca(OH)2 was used in this study as neutralization agent in acid mine drainage (AMD) treatment. Hydrated lime that is used to treat pool water samples from tin tailings located in Pengkalan Hulu, Perak was obtained from Simpang Pulai, Perak. The pH of water sample was around 2.6 to 2.8. Ten different variables of hydrated lime weights were used to treat 1 L of water sample. The weights of hydrated lime used were 0.2 g, 0.4 g, 0.6 g, 0.8 g, 1.0 g, 1.2 g, 1.4 g, 1.6 g, 1.8 g and 2.0 g. Time interval used was every 5 minutes up to minutes 30. Jar test method was used in this study. The maximum pH value of 5.93 ± 0.03 most approaches standard A and had complied standard B have been obtained using 2.0 g hydrated lime in 30-minute time interval. The concentration of arsenic, cadmium and chromium had decreased but only cadmium concentration did not comply with Standards A and B.

  7. Sequestration of phosphorus by acid mine drainage floc

    Science.gov (United States)

    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.

  8. Magnetic properties, acid neutralization capacity, and net acid production of rocks in the Animas River Watershed Silverton, Colorado

    Science.gov (United States)

    McCafferty, Anne E.; Yager, Douglas B.; Horton, Radley M.; Diehl, Sharon F.

    2006-01-01

    Federal land managers along with local stakeholders in the Upper Animas River watershed near Silverton, Colorado are actively designing and implementing mine waste remediation projects to mitigate the effects of acid mine drainage from several abandoned hard rock metal mines and mills. Local source rocks with high acid neutralization capacity (ANC) within the watershed are of interest to land managers for use in these remediation projects. A suite of representative samples was collected from propylitic to weakly sericitic-altered volcanic and plutonic rocks exposed in outcrops throughout the watershed. Acid-base accounting laboratory methods coupled with mineralogic and geochemical characterization provide insight into lithologies that have a range of ANC and net acid production (NAP). Petrophysical lab determinations of magnetic susceptibility converted to estimates for percent magnetite show correlation with the environmental properties of ANC and NAP for many of the lithologies. A goal of our study is to interpret watershed-scale airborne magnetic data for regional mapping of rocks that have varying degrees of ANC and NAP. Results of our preliminary work are presented here.

  9. Acid mine drainage in Australia: its extent and potential future liability. Supervising Scientist Report 125

    International Nuclear Information System (INIS)

    Harries, J.

    1997-01-01

    In order to better understand the impact of acid drainage in Australia and to provide a basis for assessing long-term management options, the Office of the Supervising Scientist (OSS) and the Australian Centre for Minesite Rehabilitation Research (ACMRR) initiated this study to prepare a status report on acid mine drainage in Australia. The study is supported by the Minerals Council of Australia. The coverage of this study includes all mine sites where sulphidic oxidation in mine wastes or mine workings leads to the release of contaminated drainage with off-site impacts. The objectives of the study were: 1. to quantify and characterise the generation of contaminated drainage by sulphidic oxidation from historic and current mining activities in Australia; 2. to develop a classification scheme to characterise the potential for off-site impacts from sulphidic oxidation in mine wastes; 3. to compare the cost at the national level of managing sulphidic oxidation in mine wastes and any resulting contaminated drainage with other mining and environmental costs; 4. to make recommendations based on the information received to improve the understanding and management of acid mine drainage in Australia. Information was collected on the extent and management of sulphidic oxidation and acid drainage at operating, historic and derelict mines in Australia. Mining operators, environmental officers, industry representatives, state government departments and others were asked about their experience with acid mine drainage and how it is currently managed at operating and historic mine sites. Based on the information collected, the additional cost of managing potentially acid generating wastes at operating mine sites is estimated to be about AUD 60 million per year. Potentially, the financial risk could be much greater if sulphide oxidation and release of pollutants is discovered after mine closure, as was the case for historic sites like Mt Lyell, Rum Jungle or Mt Morgan. The

  10. Development of a diatom-based multimetric index for acid mine drainage impacted depressional wetlands

    CSIR Research Space (South Africa)

    Riato, L

    2018-01-01

    Full Text Available Acid mine drainage (AMD) from coal mining in the Mpumalanga Highveld region of South Africa has caused severe chemical and biological degradation of aquatic habitats, specifically depressional wetlands, as mines use these wetlands for storage of AMD...

  11. Fractional and sequential recovery of inorganic contaminants from acid mine drainage using cryptocrystalline magnesite

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2017-06-01

    Full Text Available This study evaluated the fractional and sequential recovery of inorganic contaminants from acid mine drainage (AMD) using cryptocrystalline magnesite. Batch experimental approach was used to fulfil the goals of this study. The obtained results...

  12. Bacteria and Acidic Drainage from Coal Refuse: Inhibition by Sodium Lauryl Sulfate and Sodium Benzoate

    Science.gov (United States)

    Dugan, Patrick R.; Apel, William A.

    1983-01-01

    The application of an aqueous solution of sodium lauryl sulfate and sodium benzoate to the surface of high-sulfur coal refuse resulted in the inhibition of iron-and sulfur-oxidizing chemoautotrophic bacteria and in the decrease of acidic drainage from the refuse, suggesting that acid drainage can be abated in the field by inhibiting iron- and sulfur-oxidizing bacteria. PMID:16346347

  13. Potential risks of effluent from acid mine drainage treatment plants at abandoned coal mines.

    Science.gov (United States)

    Seo, Jaehwan; Kang, Sung-Wook; Ji, Wonhyun; Jo, Hun-Je; Jung, Jinho

    2012-06-01

    The lethal and sublethal toxicity of effluent from three acid mine drainage treatment plants were monitored from August 2009 to April 2010 using Daphnia magna (reference species) and Moina macrocopa (indigenous species). Acute lethal toxicity was observed in Samma effluent due to incomplete neutralization of acid mine drainages by the successive alkalinity producing system (SAPS). Additionally, there was no significant difference in toxicity values (TU) between D. magna and M. macrocopa (p water bodies.

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

    Science.gov (United States)

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

    2015-07-07

    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.

  15. Utilization of coal-biomass fly ash in reactive barriers for treating acid mine drainage

    International Nuclear Information System (INIS)

    Penney, K.; Mohammedelhassan, E.; Catalan, L.J.

    2009-01-01

    Coal- and biomass-derived fly ash (CBFA) was used as a reactive barrier system for treating acid mine drainage. Two reactive barriers were investigated, notably a flow-through reactive barrier with minimum disruption to the existing flow regime, and a low-permeability barrier for the construction of containment dams. A synthetic acid mine drainage system was prepared in a laboratory. Kinetic column tests were conducted to analyze the effects of acid mine drainage flow on the hydraulic conductivity and leachate composition for mixtures of mine tailings and CBFA. The tests demonstrated that a mixture of the CBFA of between 10 to 50 per cent with mine tailings increased the pH and decreased the dissolved concentrations of heavy metals in acid mine drainage. Mineral precipitation caused large reductions in hydraulic conductivity in relation to the cumulative amounts of acid mine drainage flowing through the columns. It was concluded that the number of progressive pore volumes of acid mine drainage required for achieving reductions in hydraulic conductivity is inversely related to the fly ash content of the column packs. 13 refs., 4 tabs., 7 figs.

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

    Science.gov (United States)

    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. Bioelectrochemical treatment of acid mine drainage dominated with iron

    International Nuclear Information System (INIS)

    Lefebvre, Olivier; Neculita, Carmen M.; Yue, Xiaodi; Ng, How Yong

    2012-01-01

    Highlights: ► Treatment of AMD dominated with Fe is problematic due to its low pH. ► The goal of AMD treatment is pH increasing and Fe controlled removal. ► An MFC could fulfill both these requirements by treating AMD at the aerated cathode. ► The performance was proportional to the charge transfer up to 880 C. ► The treated AMD met the discharge limits both for Fe (>99% recovery) and pH (7.9). - Abstract: Treatment of acid mine drainage (AMD) dominated with iron (Fe), the most common metal, is a long-term expensive commitment, the goal of which is to increase the pH and remove Fe. In the present study, a proton exchange membrane microbial fuel cell (MFC) showed promise for the efficient treatment of an AMD dominated with ferric iron (pH 2.4 ± 0.1; 500 mg L −1 Fe 3+ ). Briefly, Fe 3+ was reduced to Fe 2+ at the cathode of the MFC, followed by Fe 2+ re-oxidation and precipitation as oxy(hydroxi)des. Oxygen reduction and cation transfer to the cathode of the MFC further caused a rise in pH. A linear relationship was observed between the charge transferred in the MFC and the performance of the system up to 880 C. Optimal conditions were found at a charge of 662 C, achieved within 7 d at an acetate concentration of 1.6 g L −1 in a membrane MFC. This caused the pH to rise to 7.9 and resulted in a Fe removal of 99%. Treated effluent met the pH discharge limits of 6.5–9. The maximum power generation achieved under these conditions averaged 8.6 ± 2.3 W m −3 , which could help reduce the costs of full-scale bioelectrochemical treatment of AMD dominated with Fe.

  18. Integrated acid mine drainage management using fly ash.

    Science.gov (United States)

    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

  19. Oxic limestone drains for treatment of dilute, acidic mine drainage

    Science.gov (United States)

    Cravotta, Charles A.

    1998-01-01

    Limestone treatment systems can be effective for remediation of acidic mine drainage (AMD) that contains moderate concentrations of dissolved O2 , Fe3+ , or A13+ (1‐5 mg‐L‐1 ). Samples of water and limestone were collected periodically for 1 year at inflow, outflow, and intermediate points within underground, oxic limestone drains (OLDs) in Pennsylvania to evaluate the transport of dissolved metals and the effect of pH and Fe‐ and Al‐hydrolysis products on the rate of limestone dissolution. The influent was acidic and relatively dilute (pH 1 mg‐L‐1 ) but was near neutral (pH = 6.2‐7.0); Fe and Al decreased to less than 5% of influent concentrations. As pH increased near the inflow, hydrous Fe and Al oxides precipitated in the OLDs. The hydrous oxides, nominally Fe(OH)3 and AI(OH)3, were visible as loosely bound, orange‐yellow coatings on limestone near the inflow. As time elapsed, Fe(OH)3 and AI(OH)3 particles were transported downflow. During the first 6 months of the experiment, Mn 2+ was transported conservatively through the OLDs; however, during the second 6 months, concentrations of Mn in effluent decreased by about 50% relative to influent. The accumulation of hydrous oxides and elevated pH (>5) in the downflow part of the OLDs promoted sorption and coprecipitation of Mn as indicated by its enrichment relative to Fe in hydrous‐oxide particles and coatings on limestone. Despite thick (~1 mm) hydrous‐oxide coatings on limestone near the inflow, CaCO3 dissolution was more rapid near the inflow than at downflow points within the OLD where the limestone was not coated. The rate of limestone dissolution decreased with increased residence time, pH, and concentrations of Ca2+ and HCO3‐ and decreased PCO2. The following overall reaction shows alkalinity as an ultimate product of the iron hydrolysis reaction in an OLD:Fe2+ + 0.25 O2 +CaCO3 + 2.5 H2O --> Fe(OH)3 + 2 Ca2+ + 2 HCO3-where 2 moles of CaCO3 dissolve for each mole of Fe(OH)3 produced

  20. Exploring the effects of acid mine drainage on diatom teratology using geometric morphometry.

    Science.gov (United States)

    Olenici, Adriana; Blanco, Saúl; Borrego-Ramos, María; Momeu, Laura; Baciu, Călin

    2017-10-01

    Metal pollution of aquatic habitats is a major and persistent environmental problem. Acid mine drainage (AMD) affects lotic systems in numerous and interactive ways. In the present work, a mining area (Roșia Montană) was chosen as study site, and we focused on two aims: (i) to find the set of environmental predictors leading to the appearance of the abnormal diatom individuals in the study area and (ii) to assess the relationship between the degree of valve outline deformation and AMD-derived pollution. In this context, morphological differences between populations of Achnanthidium minutissimum and A. macrocephalum, including normal and abnormal individuals, were evidenced by means of valve shape analysis. Geometric morphometry managed to capture and discriminate normal and abnormal individuals. Multivariate analyses (NMDS, PLS) separated the four populations of the two species mentioned and revealed the main physico-chemical parameters that influenced valve deformation in this context, namely conductivity, Zn, and Cu. ANOSIM test evidenced the presence of statistically significant differences between normal and abnormal individuals within both chosen Achnanthidium taxa. In order to determine the relative contribution of each of the measured physico-chemical parameters in the observed valve outline deformations, a PLS was conducted, confirming the results of the NMDS. The presence of deformed individuals in the study area can be attributed to the fact that the diatom communities were strongly affected by AMD released from old mining works and waste rock deposits.

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

    OpenAIRE

    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.

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

    Science.gov (United States)

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

    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 treatment step is indicated to promote Al removal before diverting acidic mine water into alkalinity-producing materials. ?? 1998 Elsevier Science Ltd.

  3. Macroinvertebrate response to acid mine drainage: community metrics and on-line behavioural toxicity bioassay

    International Nuclear Information System (INIS)

    Gerhardt, A.; Janssens de Bisthoven, L.; Soares, A.M.V.M.

    2004-01-01

    The hypothesis is tested that toxicity of acid mine drainage can be detected by a selection of existing macroinvertebrate community and bioindicator metrices supplemented by toxicity tests with the local mosquitofish Gambusia holbrooki Girard and the shrimp Atyaephyra desmaresti Millet. The behavioural responses of A. desmaresti to acid mine drainage were recorded in the Multispecies Freshwater Biomonitor[reg], based on behaviour and survival as parameters. Bioassessment methods were based on community diversity, structure, function, and bioindicators and supplemented by chemical analysis (temperature, pH, metals). The Biological Monitoring Working Party adapted for the Iberian Peninsula, the number of predators (Coleoptera, Hemiptera) and the number of Ephemeroptera and Trichoptera taxa differentiated the sites well. The on-line toxicity test revealed pH-dependent acute toxicity of the acid mine drainage for the shrimp (LC 50 -48 h: pH-AMD=5.8) and a pH- dependent decrease in locomotory activity with the lowest-observed-response-times (LORTs) within 5 h of exposure. Shrimp were more sensitive to acid mine drainage than fish (LC 50 -48 h: pH-AMD=4.9). A new multimetric index combining toxicity testing and bioassessment methods is proposed. - Toxicity of acid mine drainage was evaluated by macroinvertebrate bioassessment and a new on-line rapid behavioural toxicity test with Atyaephyra desmaresti (Crustacea)

  4. Macroinvertebrate response to acid mine drainage: community metrics and on-line behavioural toxicity bioassay

    Energy Technology Data Exchange (ETDEWEB)

    Gerhardt, A.; Janssens de Bisthoven, L.; Soares, A.M.V.M

    2004-07-01

    The hypothesis is tested that toxicity of acid mine drainage can be detected by a selection of existing macroinvertebrate community and bioindicator metrices supplemented by toxicity tests with the local mosquitofish Gambusia holbrooki Girard and the shrimp Atyaephyra desmaresti Millet. The behavioural responses of A. desmaresti to acid mine drainage were recorded in the Multispecies Freshwater Biomonitor[reg], based on behaviour and survival as parameters. Bioassessment methods were based on community diversity, structure, function, and bioindicators and supplemented by chemical analysis (temperature, pH, metals). The Biological Monitoring Working Party adapted for the Iberian Peninsula, the number of predators (Coleoptera, Hemiptera) and the number of Ephemeroptera and Trichoptera taxa differentiated the sites well. The on-line toxicity test revealed pH-dependent acute toxicity of the acid mine drainage for the shrimp (LC{sub 50}-48 h: pH-AMD=5.8) and a pH- dependent decrease in locomotory activity with the lowest-observed-response-times (LORTs) within 5 h of exposure. Shrimp were more sensitive to acid mine drainage than fish (LC{sub 50}-48 h: pH-AMD=4.9). A new multimetric index combining toxicity testing and bioassessment methods is proposed. - Toxicity of acid mine drainage was evaluated by macroinvertebrate bioassessment and a new on-line rapid behavioural toxicity test with Atyaephyra desmaresti (Crustacea)

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

    Science.gov (United States)

    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.

  6. Ion exchange system design for removal of heavy metals from acid mine drainage wastewater

    Directory of Open Access Journals (Sweden)

    R. S. Sapkal

    2010-11-01

    Full Text Available This paper discusses the methodology used to determine the optimal ion-exchange column size to process all separate batchesof feeds from acid mine drainage wastewater.The optimal design ensures the best utilization of resin material and therefore results in a minimum amount of spent resins.Ion exchanger materials have been studied for removing heavy metals from a metal bearing wastes. For the current treatment,a facility has been designed for the removal of heavy metals from the acid mine drainage (AMD waste by the ion-exchange technology.

  7. Remediation of acid mine drainage using magnesite and its bentonite clay composite

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2015-12-01

    Full Text Available .............................. 46 Table 3.1: Synthetic acid mine drainage used in this study .................................................. 73 Table 3.2: Chemical compositions of acid mine drainage before and after contacting magnesite.... The reaction of AMD with magnesite at an optimum solid: liquid ratio of 1:100 and contact time of 60 min led to an increase in pH, reaching a maximum pH of 10, resulting in significant precipitation of most metal species. Increase of pH in solution...

  8. Hydrogeological assessment of Acid mine Drainage impacts in the West Rand Basin, Gauteng Province

    CSIR Research Space (South Africa)

    Hobbs, PJ

    2007-08-01

    Full Text Available HYDROGEOLOGICAL ASSESSMENT OF ACID MINE DRAINAGE IMPACTS IN THE WEST RAND BASIN, GAUTENG PROVINCE Principal Author PJ Hobbs (Pr.Sci.Nat.) Co-author JE Cobbing (Pr.Sci.Nat.) August 2007 Report prepared for CSIR / THRIP Document... it is published. A Hydrogeological Assessment of Acid Mine Drainage Report No. Impacts in the West Rand Basin, Gauteng Province CSIR/NRE/WR/ER/2007/0097/C CSIR Natural Resources and the Environment (i) The “Lodge” spring rising...

  9. Disinfectant properties of acid mine drainage: its effects on enteric bacteria in a sewage-contaminated stream

    Energy Technology Data Exchange (ETDEWEB)

    Keating, S.T.; Celements, C.M.; Ostrowski, D.; Hanlon, T. [St. Francis College, Loretto, PA (United States). Dept. of Biology

    1996-09-01

    Studies conducted in a Cambria County, Pennsylvania, acid mine drainage stream suggest that mine drainage rapidly reduces in situ populations of fecal bacteria associated with inputs of untreated sewage. The density of lactose-fermenting bacteria, mostly coliform species from sewage, declined 1000-fold over a distance of less than 100 m following the input of high acid (pH 3.5 to 4.0), high ferrous iron (45 mg/l) acid mine drainage. Enterobacteriaceae were isolated from the stream, identified, and tested for tolerance to acid mine drainage by exposing cells to drainage for 10 minutes at 0 or 37{degree}C. Populations of all tested isolates were reduced by this treatment, but some isolates were significantly less affected than others. Thus, while mine drainage may act as a disinfectant, it may not reduce all populations of disease-causing intestinal bacteria at an equal, rapid rate.

  10. Acid Water Neutralization Using Microbial Fuel Cells: An Alternative for Acid Mine Drainage Treatment

    Directory of Open Access Journals (Sweden)

    Eduardo Leiva

    2016-11-01

    Full Text Available Acid mine drainage (AMD is a complex environmental problem, which has adverse effects on surface and ground waters due to low pH, high toxic metals, and dissolved salts. New bioremediation approach based on microbial fuel cells (MFC can be a novel and sustainable alternative for AMD treatment. We studied the potential of MFC for acidic synthetic water treatment through pH neutralization in batch-mode and continuous-flow operation. We observed a marked pH increase, from ~3.7 to ~7.9 under batch conditions and to ~5.8 under continuous-flow operation. Likewise, batch reactors (non-MFC inoculated with different MFC-enriched biofilms showed a very similar pH increase, suggesting that the neutralization observed for batch operation was due to a synergistic influence of these communities. These preliminary results support the idea of using MFC technologies for AMD remediation, which could help to reduce costs associated with conventional technologies. Advances in this configuration could even be extrapolated to the recovery of heavy metals by precipitation or adsorption processes due to the acid neutralization.

  11. Attenuation of pollution arising from acid mine drainage by a natural wetland on the Witwatersrand

    Directory of Open Access Journals (Sweden)

    Marc S. Humphries

    2017-01-01

    Full Text Available Wetlands are well known to be efficient at sequestering pollutants from contaminated water. We investigated metal accumulation in the peats of the Klip River, a natural wetland that has received contaminated water from gold mining operations in Johannesburg for over 130 years. Previous work conducted in the downstream portion identified the wetland as an important system for sequestering metals. We focused on the upstream section of the wetland, more proximal to the source of acid mine drainage, to provide a better understanding of the pollutant sources and the role of the wetland in pollutant attenuation. Geochemical and mineralogical analyses of peat cores revealed considerable metal enrichments in the peat ash, particularly in Co, Ni, Zn, Pb, Cu and U. Metal concentrations are typically between 4 to 8 times higher than those previously reported for the downstream, more distal portion of the wetland. The distribution of metal accumulation within the peat profiles suggests that contamination arises from a combination of sources and processes. Elevated concentrations in the shallow peat are attributed to the input of contaminated surface water via tributaries that drain the Central Rand Goldfield, whereas enrichments in the deeper peat suggest significant sub-surface inflow of contaminated water through the underlying dolomitic rocks. Metal immobilisation occurs through a combination of mechanisms, which include the precipitation of gypsum, metal sulfides, Fe-Mn oxyhydroxides and phosphates. Our study highlights the environmental and economic importance of natural wetland systems which have the ability to accumulate large quantities of metals and thus remediate polluted waters.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

    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

  13. Macroinvertebrate response to acid mine drainage: community metrics and on-line behavioural toxicity bioassay

    Energy Technology Data Exchange (ETDEWEB)

    A. Gerhardt; L. Janssens de Bisthoven; A.M.V.M. Soares [University of Aveiro, Aveiro (Portugal). Department of Biology

    2004-07-01

    The hypothesis is tested that toxicity of acid mine drainage can be detected by a selection of existing macroinvertebrate community and bioindicator metrices supplemented by toxicity tests with the local mosquitofish Gambusia holbrooki Girard and the shrimp Atyaephyra desmaresti Millet. The behavioural responses of A. desmaresti to acid mine drainage were recorded in the Multispecies Freshwater Biomonitor{reg_sign}, based on behaviour and survival as parameters. Bioassessment methods were based on community diversity, structure, function, and bioindicators and supplemented by chemical analysis (temperature, pH, metals). The Biological Monitoring Working Party adapted for the Iberian Peninsula, the number of predators (Coleoptera, Hemiptera) and the number of Ephemeroptera and Trichoptera taxa differentiated the sites well. The on-line toxicity test revealed pH-dependent acute toxicity of the acid mine drainage for the shrimp (LC{sub 50}-48 h: pH-AMD=5.8) and a pH-dependent decrease in locomotory activity with the lowest-observed-response-times (LORTs) within 5 h of exposure. Shrimp were more sensitive to acid mine drainage than fish (LC{sub 50}-48 h: pH-AMD=4.9). A new multimetric index combining toxicity testing and bioassessment methods is proposed.

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  16. Influence of acid mine drainage, and its remediation on lakewater quality and benthic invertebrate communities

    Czech Academy of Sciences Publication Activity Database

    Mocq, Julien; Hare, L.

    2018-01-01

    Roč. 229, č. 2 (2018), č. článku 28. ISSN 0049-6979 Institutional support: RVO:60077344 Keywords : metals * benthos * acid mine drainage Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.702, year: 2016 https://link.springer.com/article/10.1007/s11270-017-3671-3

  17. Macroinvertebrate community response to acid mine drainage in rivers of the High Andes (Bolivia).

    NARCIS (Netherlands)

    Damme, P.A. van; Hamel, C.; Ayala, A.; Bervoets, L.

    2008-01-01

    Several High Andes Rivers are characterized by inorganic water pollution known as acid mine drainage (AMD). The aim of this study was to assess the relationship between metal concentrations in the sediments and the macroinvertebrate communities in two river basins affected by AMD. In general, the

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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 ...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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...

  2. Simulating the Fate and Transport of an Acid Mine Drainage Release

    Science.gov (United States)

    On August 5, 2015, approximately 3 million gallons of acid mine drainage were released from the Gold King Mine into Cement Creek in the San Juan River watershed (CO, NM, UT). The release further mobilized additional metals, which resulted in a large mass of solids and dissolved m...

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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...

  5. Metals Recovery from Acid Mine Drainage and Possibilities for their Utilization

    Czech Academy of Sciences Publication Activity Database

    Michalková, E.; Schwarz, M.; Pulišová, Petra; Máša, B.; Sudovský, P.

    2013-01-01

    Roč. 22, č. 4 (2013), s. 1111-1118 ISSN 1230-1485 R&D Projects: GA MŠk 7AMB12SK155 Institutional support: RVO:61388980 Keywords : acid mine drainage * ferric pigments * adsorbent Subject RIV: CA - Inorganic Chemistry Impact factor: 0.600, year: 2013

  6. Acid drainage from coal mining: Effect on paddy soil and productivity of rice.

    Science.gov (United States)

    Choudhury, Burhan U; Malang, Akbar; Webster, Richard; Mohapatra, Kamal P; Verma, Bibhash C; Kumar, Manoj; Das, Anup; Islam, Mokidul; Hazarika, Samarendra

    2017-04-01

    Overburden and acid drainage from coal mining is transforming productive agricultural lands to unproductive wasteland in some parts of Northeast India. We have investigated the adverse effects of acid mine drainage on the soil of rice paddy and productivity by comparing them with non-mined land and abandoned paddy fields of Jaintia Hills in Northeast India. Pot experiments with a local rice cultivar (Myngoi) as test crop evaluated biological productivity of the contaminated soil. Contamination from overburden and acid mine drainage acidified the soil by 0.5 pH units, increased the exchangeable Al 3+ content 2-fold and its saturation on clay complexes by 53%. Available sulfur and extractable heavy metals, namely Fe, Mn and Cu increased several-fold in excess of critical limits, while the availability of phosphorus, potassium and zinc contents diminished by 32-62%. The grain yield of rice was 62% less from fields contaminated with acid mine drainage than from fields that have not suffered. Similarly, the amounts of vegetation, i.e. shoots and roots, in pots filled with soil from fields that received acid mine drainage were 59-68% less than from uncontaminated land (average shoot weight: 7.9±2.12gpot -1 ; average root weight: 3.40±1.15gpot -1 ). Paddy fields recovered some of their productivity 4years after mining ceased. Step-wise multiple regression analysis affirmed that shoot weight in the pots and grain yield in field were significantly (p<0.01) and positively influenced by the soil's pH and its contents of K, N and Zn, while concentration of S in excess of threshold limits in contaminated soil significantly (p<0.01) reduced the weight of shoots in the pots and grain yield in the field. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Recovery of iron oxides from acid mine drainage and their application as adsorbent or catalyst.

    Science.gov (United States)

    Flores, Rubia Gomes; Andersen, Silvia Layara Floriani; Maia, Leonardo Kenji Komay; José, Humberto Jorge; Moreira, Regina de Fatima Peralta Muniz

    2012-11-30

    Iron oxide particles recovered from acid mine drainage represent a potential low-cost feedstock to replace reagent-grade chemicals in the production of goethite, ferrihydrite or magnetite with relatively high purity. Also, the properties of iron oxides recovered from acid mine drainage mean that they can be exploited as catalysts and/or adsorbents to remove azo dyes from aqueous solutions. The main aim of this study was to recover iron oxides with relatively high purity from acid mine drainage to act as a catalyst in the oxidation of dye through a Fenton-like mechanism or as an adsorbent to remove dyes from an aqueous solution. Iron oxides (goethite) were recovered from acid mine drainage through a sequential precipitation method. Thermal treatment at temperatures higher than 300 °C produces hematite through a decrease in the BET area and an increase in the point of zero charge. In the absence of hydrogen peroxide, the solids adsorbed the textile dye Procion Red H-E7B according to the Langmuir model, and the maximum amount adsorbed decreased as the temperature of the thermal treatment increased. The decomposition kinetics of hydrogen peroxide is dependent on the H(2)O(2) concentration and iron oxides dosage, but the second-order rate constant normalized to the BET surface area is similar to that for different iron oxides tested in this and others studies. These results indicate that acid mine drainage could be used as a source material for the production of iron oxide catalysts/adsorbents, with comparable quality to those produced using analytical-grade reagents. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. A full-scale porous reactive wall for prevention of acid mine drainage

    International Nuclear Information System (INIS)

    Benner, S.G.; Blowes, D.W.; Ptacek, C.J.

    1997-01-01

    The generation and release of acidic drainage containing high concentrations of dissolved metals from decommissioned mine wastes is an environmental problem of international scale. A potential solution to many acid drainage problems is the installation of permeable reactive walls into aquifers affected by drainage water derived from mine waste materials. A permeable reactive wall installed into an aquifer impacted by low-quality mine drainage waters was installed in August 1995 at the Nickel Rim mine site near Sudbury, Ontario. The reactive mixture, containing organic matter, was designed to promote bacterially mediated sulfate reduction and subsequent metal sulfide precipitation. The reactive wall is installed to an average depth of 12 feet (3.6 m) and is 49 feet (15 m) long perpendicular to ground water flow. The wall thickness (flow path length) is 13 feet (4 m). Initial results, collected nine months after installation, indicate that sulfate reduction and metal sulfide precipitation is occurring. The reactive wall has effectively removed the capacity of the ground water to generate acidity on discharge to the surface. Calculations based on comparison to previously run laboratory column experiments indicate that the reactive wall has potential to remain effective for at least 15 years

  9. Acid-neutralizing potential of minerals in intrusive rocks of the Boulder batholith in northern Jefferson County, Montana

    Science.gov (United States)

    Desborough, George A.; Briggs, Paul H.; Mazza, Nilah; Driscoll, Rhonda

    1998-01-01

    addition to that provided by the 0.36-1.4 weight percent calcite present in these samples. The total rock ANP is thus equivalent to that of many sedimentary rocks that are generally believed to be among the most efficient for attenuation of acidic waters. The long-term ANP contributed by biotite, tremolite, feldspars, and possibly unidentified minerals in these rocks, as well as calcite, are all important with regard to their natural remediation of degraded water quality originating from Fe-sulfide rich mineral deposits and the associated mine wastes and acid-mine drainage water.

  10. Pervious concrete reactive barrier for removal of heavy metals from acid mine drainage − column study

    Energy Technology Data Exchange (ETDEWEB)

    Shabalala, Ayanda N., E-mail: Ayanda.Shabalala@ump.ac.za [University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa); Ekolu, Stephen O. [University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa); Diop, Souleymane [Council for Geoscience, Private bag x112, Pretoria, 0001 (South Africa); Solomon, Fitsum [University of Johannesburg, PO Box 524, Auckland Park 2006 (South Africa)

    2017-02-05

    Highlights: • Pervious concrete raises the low pH of acid mine drainage up to 12; heavy metals precipitate. • Pervious concrete successfully removed greater than 99% of inorganic contaminants. • Ca(OH){sub 2} in pervious concrete reacts with SO{sub 4}{sup 2−} in acid mine drainage to form expansive gypsum. • Incorporating fly ash into pervious concrete mitigates damage caused by gypsum. • Pervious concrete reactive barrier offers a promising alternative method for treatment of acid mine drainage. - Abstract: This paper presents a column study conducted to investigate the potential use of pervious concrete as a reactive barrier for treatment of water impacted by mine waste. The study was done using acid mine drainage (AMD) collected from a gold mine (WZ) and a coalfield (TDB). Pervious concrete mixtures consisting of Portland cement CEM I 52.5R with or without 30% fly ash (FA) were prepared at a water-cementitious ratio of 0.27 then used to make cubes which were employed in the reactor columns. It was found that the removal efficiency levels of Al, Fe, Mn, Co and Ni were 75%, 98%, 99%, 94% and 95% for WZ; 87%, 96%, 99%, 98% and 90% for TDB, respectively. The high rate of acid reduction and metal removal by pervious concrete is attributed to dissolution of portlandite which is a typical constituent of concrete. The dominant reaction product in all four columns was gypsum, which also contributed to some removal of sulphate from AMD. Formation of gypsum, goethite, and Glauber’s salt were identified. Precipitation of metal hydroxides seems to be the dominant metal removal mechanism. Use of pervious concrete offers a promising alternative treatment method for polluted or acidic mine water.

  11. Pervious concrete reactive barrier for removal of heavy metals from acid mine drainage − column study

    International Nuclear Information System (INIS)

    Shabalala, Ayanda N.; Ekolu, Stephen O.; Diop, Souleymane; Solomon, Fitsum

    2017-01-01

    Highlights: • Pervious concrete raises the low pH of acid mine drainage up to 12; heavy metals precipitate. • Pervious concrete successfully removed greater than 99% of inorganic contaminants. • Ca(OH)_2 in pervious concrete reacts with SO_4"2"− in acid mine drainage to form expansive gypsum. • Incorporating fly ash into pervious concrete mitigates damage caused by gypsum. • Pervious concrete reactive barrier offers a promising alternative method for treatment of acid mine drainage. - Abstract: This paper presents a column study conducted to investigate the potential use of pervious concrete as a reactive barrier for treatment of water impacted by mine waste. The study was done using acid mine drainage (AMD) collected from a gold mine (WZ) and a coalfield (TDB). Pervious concrete mixtures consisting of Portland cement CEM I 52.5R with or without 30% fly ash (FA) were prepared at a water-cementitious ratio of 0.27 then used to make cubes which were employed in the reactor columns. It was found that the removal efficiency levels of Al, Fe, Mn, Co and Ni were 75%, 98%, 99%, 94% and 95% for WZ; 87%, 96%, 99%, 98% and 90% for TDB, respectively. The high rate of acid reduction and metal removal by pervious concrete is attributed to dissolution of portlandite which is a typical constituent of concrete. The dominant reaction product in all four columns was gypsum, which also contributed to some removal of sulphate from AMD. Formation of gypsum, goethite, and Glauber’s salt were identified. Precipitation of metal hydroxides seems to be the dominant metal removal mechanism. Use of pervious concrete offers a promising alternative treatment method for polluted or acidic mine water.

  12. OCHRE PRECIPITATES AND ACID MINE DRAINAGE IN A MINE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    BRANISLAV MÁŠA

    2012-03-01

    Full Text Available This paper is focused to characterize the ochre precipitates and the mine water effluents of some old mine adits and settling pits after mining of polymetallic ores in Slovakia. It was shown that the mine water effluents from two different types of deposits (adits; settling pits have similar composition and represent slightly acidic sulphate water (pH in range 5.60-6.05, sulphate concentration from 1160 to 1905 g.dm-3. The ochreous precipitates were characterized by methods of X-ray diffraction analysis (XRD, scanning electron microscopy (SEM and B.E.T. method for measuring the specific surface area and porosity. The dominant phases were ferrihydrite with goethite or goethite with lepidocrocide.

  13. Aquatic insect deversity and biomass in a stream marginally polluted by acid strip mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Tomkiewicz, S.M. Jr.; Dunson, W.A.

    1977-01-01

    Upper Three Runs receives a point source of acid mine drainage from a small acid feeder stream and the pH of the main stream falls from above 6 to about 4.5. Over the 1.2 km study section below the introduction of acid drainage, the pH rises to 5.0. This moderate degree of mine acid pollution has severely affected aquatic insect populations. The acid feeder itself (pH near 3.2) was inhabited only by a chironomid, a megalopteran (Sialis), and the caddisfly Ptilostomis. Biomass was very low (140 mg dry weight/m/sup 2/). The drainage of the acid feeder into the stream caused a drop in the Shannon-Weiner diversity index from 3.10 to 1.95, and a drop in biomass from 6.5 g/m/sup 2/ to 2.2 g/m/sup 2/. At the two stations further downstream, the diversity index remained relatively constant and the biomass leveled off at about 1.2 g/m/sup 2/. The number of taxa declined steadily from 30 at the control station to 13 at the lowest site. Populations of Coleoptera, Ephemeroptera and Trichoptera showed little or no recovery as the acid pollution ameliorated slightly. Representatives of the orders Diptera and Plecoptera (especially Nemoura) showed a decided recovery and increase in numbers near pH 5.0. If fish were able to survive in acid mine polluted waters of pH's between 4.5 and 5.0 they should find sufficient insect food for maintenance of a limited population.

  14. Techniques to correct and prevent acid mine drainage: A review

    Directory of Open Access Journals (Sweden)

    Santiago Pozo-Antonio

    2014-01-01

    Full Text Available En la actualidad uno de los problemas medioambientales con mayor necesidad de actuación es la contaminación por la formación de drenajes ácidos de mina (AMD: “Acid Mine Drainage” procedentes de estériles de mina. Este es el término utilizado para describir el drenaje generado por la oxidación natural de sulfuros minerales que son expuestos a la acción combinada de agua y oxígeno atmosférico. Los minerales responsables de la generación de AMD son los sulfuros de hierro (pirita, FeS2 y en menor medida la pirrotita, Fe1-XS, los cuales son estables e insolubles mientras no se encuentren en contacto con agua y oxígeno atmosférico. Sin embargo, como consecuencia de la actividad minera, estos dos sulfuros son expuestos a condiciones ambientales oxidantes. La necesidad de prevenir la formación de AMD ha desarrollado numerosas investigaciones sobre los mecanismos de oxidación y su prevención. En el presente trabajo además de realizar una explicación y valoración teórica del proceso de oxidación de la pirita también se realiza un compendio de las medidas preventivas y correctoras más empleadas.

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

    Science.gov (United States)

    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.

  16. Uniform particles formed by hydrolysis of acid mine drainage with urea

    Czech Academy of Sciences Publication Activity Database

    Šubrt, Jan; Michalková, E.; Boháček, Jaroslav; Lukáč, Jozef; Gánovská, Z.; Máša, B.

    2011-01-01

    Roč. 106, 1-2 (2011), s. 12-18 ISSN 0304-386X R&D Projects: GA MŠk LC523; GA MŠk(CZ) MEB0810136 Institutional research plan: CEZ:AV0Z40320502 Keywords : acid mine drainage * urea hydrolysis * morphology * particles * surface area Subject RIV: CA - Inorganic Chemistry Impact factor: 2.027, year: 2011

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

    Science.gov (United States)

    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. Published by Elsevier B.V.

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

    Science.gov (United States)

    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.

  19. Bioaccumulation of metals in constructed wetlands used to treat acid drainage

    International Nuclear Information System (INIS)

    Edwards, G.S.; Mays, P.A.

    1994-01-01

    Constructed wetlands are being used extensively as a potential mitigation for acid drainage. However, removal of metals to meet compliance requirements has varied among wetlands, ranging from partial to total success. In addition, wetlands are sinks for contaminants found in acid drainage, and bioaccumulation of these contaminants to levels that would adversely affect the food web is of growing concern. The primary objective of this project was to determine whether bioaccumulation of metals occurs in wetlands constructed for treatment of acid drainage. Water, sediment, plant and benthos samples were collected from two wetlands constructed by the Tennessee Valley Authority and a natural wetland in the spring and fall of 1992, and metal concentrations were determined. One of the constructed wetlands, Impoundment 1, has generally been in compliance for NPDES; the other, Widow's Creek, has never been in compliance. Preliminary results indicate similarities in sediment and plant metal concentrations between Impoundment 1 and the natural wetland and greater metal concentrations in the sediment and plants at Widow's Creek. Data also indicate that Mn, Zn, Cu, Ni, and Cr are being accumulated in the plants at each wetland. However, accumulation of metals by these plants probably accounts for only a small percentage of the removal of the annual metal load supplied to each wetland. Bioaccumulation of metals in the benthic organisms at each wetland is currently being investigated

  20. Environmental geochemistry of acid mine drainage water at Indus coal mine at Lakhra, Sindh Pakistan

    International Nuclear Information System (INIS)

    Siddique, I.; Shah, M.T.

    2000-01-01

    The annual coal production of Pakistan is about 3,637, 825 tones which is about 6% of the country's energy resources, out of this 1,241, 965 tones of coal was produced/ mined from the Lakhra coal field, District Dadu, Sindh which after the Thar coal field is the second largest coal field of Pakistan. At this coal field more than 58 mining companies are engaged in exploring the hidden wealth of the country. The problem of acid mine drainage, is caused by the passage or seepage of water, through mines where iron disulfides, usually pyrites, are exposed to the oxidizing action of water, air and bacteria, is the main problem faced by the mining companies. The geochemical analysis of acid mine drainage water collected from Indus coal mine no. 6 shows that beside its higher pH, total Dissolved Solids and Sulfates, it also posses higher amount of heavy metals like Cd, Cu, Pb, Co, Ni and Fe. This acid mine drainage water not only damages the mine structures but is also harmful to soil and ecology. (author)

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

    International Nuclear Information System (INIS)

    Tollin, S.

    1993-01-01

    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

  2. Study of environmental pollution and mineralogical characterization of sediment rivers from Brazilian coal mining acid drainage

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luis F.O., E-mail: felipeqma@hotmail.com [Environmental Science and Nanotechnology Department, Institute of Environmental Research and Human Development – IPADH, Capivari de Baixo, Santa Catarina (Brazil); Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Fdez- Ortiz de Vallejuelo, Silvia; Martinez-Arkarazo, Irantzu; Castro, Kepa [Department of Analytical Chemistry, University of the Basque Country (EHU/UPV), P.O. Box 644, 48080 Bilbao, Basque Country (Spain); Oliveira, Marcos L.S. [Environmental Science and Nanotechnology Department, Institute of Environmental Research and Human Development – IPADH, Capivari de Baixo, Santa Catarina (Brazil); Sampaio, Carlos H.; Brum, Irineu A.S. de [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Gonçalves, 9500, Bairro Agronomia, CEP: 91501-970, Porto Alegre, RS (Brazil); Leão, Felipe B. de; Taffarel, Silvio R. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Madariaga, Juan M. [Department of Analytical Chemistry, University of the Basque Country (EHU/UPV), P.O. Box 644, 48080 Bilbao, Basque Country (Spain)

    2013-03-01

    Acid drainage from coal mines and metal mining is a major source of underground and surface water contamination in the world. The coal mining acid drainage (CMAD) from mine contains large amount of solids in suspension and a high content of sulphate and dissolved metals (Al, Mn, Zn, Cu, Pb, Fe, etc.) that finally are deposited in the rivers. Since this problem can persist for centuries after mine abandonment, it is necessary to apply multidisciplinary methods to determine the potential risk in a determinate area. These multidisciplinary methods must include molecular and elemental analysis and finally all information must be studied statistically. This methodology was used in the case of coal mining acid drainage from the Tubarao River (Santa Catarina, Brazil). During molecular analysis, Raman Spectroscopy, electron bean, and X-ray diffraction (XRD) have been proven very useful for the study of minerals present in sediment rivers near this CMAD. The obtained spectra allow the precise identification of the minerals as jarosite, quartz, clays, etc. The elemental analysis (Al, As, Fe, K, Na, Ba, Mg, Mn, Ti, V, Zn, Ag, Co, Li, Mo, Ni, Se, Sn, W, B, Cr, Cu, Pb and Sr) was realised by inductively coupled plasma mass spectrometry (ICP-MS). Statistical analysis (Principal Component Analysis) of these dates of concentration reveals the existence of different groups of samples with specific pollution profiles in different areas of the Tubarao River. Highlights: ► Increasing coal drainage sediments geochemical information will increase human health information in this area. ► Brazilian coal mining information will increase recuperation planning information. ► The nanominerals showed strong sorption ability to aqueous hazardous elements.

  3. Study of environmental pollution and mineralogical characterization of sediment rivers from Brazilian coal mining acid drainage

    International Nuclear Information System (INIS)

    Silva, Luis F.O.; Fdez- Ortiz de Vallejuelo, Silvia; Martinez-Arkarazo, Irantzu; Castro, Kepa; Oliveira, Marcos L.S.; Sampaio, Carlos H.; Brum, Irineu A.S. de; Leão, Felipe B. de; Taffarel, Silvio R.; Madariaga, Juan M.

    2013-01-01

    Acid drainage from coal mines and metal mining is a major source of underground and surface water contamination in the world. The coal mining acid drainage (CMAD) from mine contains large amount of solids in suspension and a high content of sulphate and dissolved metals (Al, Mn, Zn, Cu, Pb, Fe, etc.) that finally are deposited in the rivers. Since this problem can persist for centuries after mine abandonment, it is necessary to apply multidisciplinary methods to determine the potential risk in a determinate area. These multidisciplinary methods must include molecular and elemental analysis and finally all information must be studied statistically. This methodology was used in the case of coal mining acid drainage from the Tubarao River (Santa Catarina, Brazil). During molecular analysis, Raman Spectroscopy, electron bean, and X-ray diffraction (XRD) have been proven very useful for the study of minerals present in sediment rivers near this CMAD. The obtained spectra allow the precise identification of the minerals as jarosite, quartz, clays, etc. The elemental analysis (Al, As, Fe, K, Na, Ba, Mg, Mn, Ti, V, Zn, Ag, Co, Li, Mo, Ni, Se, Sn, W, B, Cr, Cu, Pb and Sr) was realised by inductively coupled plasma mass spectrometry (ICP-MS). Statistical analysis (Principal Component Analysis) of these dates of concentration reveals the existence of different groups of samples with specific pollution profiles in different areas of the Tubarao River. Highlights: ► Increasing coal drainage sediments geochemical information will increase human health information in this area. ► Brazilian coal mining information will increase recuperation planning information. ► The nanominerals showed strong sorption ability to aqueous hazardous elements

  4. Development of a new methodology for mitigating acid mine drainage (AMD) at reclaimed surface mines

    International Nuclear Information System (INIS)

    Ackman, T.E.; Kim, A.G.

    1993-01-01

    A 1.2 hectare (ha) experimental site located on a 14.5 ha reclaimed surface mine in Greene County, PA was injected with a 141 cubic meters (m 3 ) of fly ash and fluidized bed combustion (FBC) ash grout that included acid mine drainage (AMD) sludge. An evaluation of this AMD abatement approach by the Bureau of Mines found that the average net acidity and concentrations of several metal ions at the discharge seep and monitoring wells decreased after grouting. Changes in metal concentrations were assumed to be related to alkaline addition and/or encapsulation. Initial results indicate that this technique is potentially an effective AMD abatement method

  5. Behaviour of U-Series Radionuclides in an Estuary Affected by Acid Mine Drainage and Industrial Releases

    Energy Technology Data Exchange (ETDEWEB)

    Hierro, A.; Bolivar, J. P.; Vaca, F. [Department of Applied Physics, University of Huelva, Huelva (Spain)

    2013-07-15

    The estuary formed by the Tinto and Odiel rivers is an ecosystem of great interest because it is seriously affected by the acid mine drainage (AMD) produced by the high mining activity in the watersheds of these rivers, generating in their waters an extremely low pH (2.5- 3.5), and consequently high concentrations of heavy metals and natural radionuclides in dissolution. Secondly, in their estuary there is a large chemical industrial complex, and in particular two phosphoric acid production plants, which use a sedimentary phosphate rock from Morocco as raw material containing at approximately 1.5 Bq/g of U-series radionuclides, which produce annually about 2.5-3 millions of tonnes of a byproduct, called phosphogypsum (PG). PG contains high concentrations of some U-series radionuclides as {sup 226}Ra (650 Bq/kg), {sup 210}Pb-{sup 210}Po (600 Bq/kg) or {sup 230}Th (450 Bq/kg). Seventeen sampling stations along the end of these rivers and this estuary were selected to study the behaviour of U-series radionuclides in the recent surface sediments and its waters. The most relevant results show a non-conservative behaviour of Uisotopes, precipitating in the zone where large pH changes (3-5) are produced. This behaviour is different from the majority of typical estuaries where only salinity changes are produced, and therefore, a conservative behaviour of uranium is observed. (author)

  6. Heavy Metals and Radioactivity Reduction from Acid Mine Drainage Lime Neutralized Sludge

    Science.gov (United States)

    Mashifana, T.; Sithole, N.

    2018-03-01

    The worldwide known treatment processes of acid mine drainage result into the formation of hydrous ferric oxides that is amorphous, poorly crystalline and into the generation of hazardous voluminous sludge posing threat to the environment. Applicable treatment technologies to treat hazardous solid material and produce useful products are limited and in most cases nonexistence. A chemical treatment process utilizing different reagents was developed to treat hazardous acid mine drainage (AMD) sludge with the objectives to conduct radioactivity assessment of the sludge generated from lime treatment process and determine the reagent that provides the best results. Leaching with 0.5 M citric acid, 0.4 M oxalic acid, 0.5 M sodium carbonate and 0.5 M sodium bicarbonate was investigated. The leaching time applied was 24 hours at 25 °C. The characterization of the raw AMD revealed that the AMD sludge from lime treatment process is radioactive. The sludge was laden with radioactive elements namely, 238U, 214Pb, 226Ra, 232Th, 40K and 214Bi. 0.5 M citric acid provided the best results and the hazardous contaminants were significantly reduced. The constituents in the sludge after treatment revealed that there is a great potential for the sludge to be used for other applications such as building and construction.

  7. The effect of electro-activation and eggshell powder on the neutralization of acid mine drainage

    Directory of Open Access Journals (Sweden)

    Alexey Kastyuchik

    2017-01-01

    Full Text Available Acid mine drainage (AMD production by sulfide mine tailing (SMT is a major environmental preoccupation because it can degrade water surface quality on account of its strong acidity and advanced content of sulfide, iron (Fe and other metals and metalloids. Acid neutralization and the precipitation of metals present in AMD were carried out by electro-activation with ion-exchange membranes, which is based on the self-generation of necessary conditions for acid neutralization and metal precipitation. The treatment of SMT was carried out by using an electro-activation cell generated alkaline solution in the cathode compartment. After 60 min of electro-activation, a pHcatholyte of 7.9–9.6, depending on the experimental conditions, was obtained. The absence of Fe and other trace metal ions in the catholyte provide evidence that the electro-activation of SMT promotes the precipitation of insoluble trace metals in the cathode compartment. This approach can be applied to real conditions in combination with a pretreatment of SMT neutralization, in which biological calcareous amendments are available. Finally, the electro-activation technology of acid mine drainage may be a feasible, cost-effective approach for SMT neutralization because it focuses on sustainable development.

  8. Acid mine drainage abatement resulting from pressure grouting of buried bituminous mine spoils

    International Nuclear Information System (INIS)

    Scheetz, B.; Silsbee, M.; Schueck, J.

    1998-01-01

    A 37 acre surface coal mine located in Clinton County, PA, USA, was mined and reclaimed between 1974 and 1977. Buried pyrite-rich pit floor cleanings and tipple refuse were found to be producing severe acid mine drainage. The pyritic material is located in discrete piles or pods in the backfill. The pods and the resulting contaminant plumes were initially defined using geophysical techniques and confirmed by drilling. The approach taken was to use a cementitious grout, composed of fluidized bed combustion ash and water, which would be placed in a manner which would prevent water and oxygen from contacting the pyritic materials. Statistically significant water quality improvements have been noted as a result of the grouting. After four years of post-grouting monitoring, reductions in concentrations of most of the mine drainage parameters range from 40 to 90%. 12 refs., 1 fig., 4 tabs

  9. Silicon Isotope Fractionation During Acid Water-Igneous Rock Interaction

    Science.gov (United States)

    van den Boorn, S. H.; van Bergen, M. J.; Vroon, P. Z.

    2007-12-01

    Silica enrichment by metasomatic/hydrothermal alteration is a widespread phenomenon in crustal environments where acid fluids interact with silicate rocks. High-sulfidation epithermal ore deposits and acid-leached residues at hot-spring settings are among the best known examples. Acid alteration acting on basalts has also been invoked to explain the relatively high silica contents of the surface of Mars. We have analyzed basaltic-andesitic lavas from the Kawah Ijen volcanic complex (East Java, Indonesia) that were altered by interaction with highly acid (pH~1) sulfate-chloride water of its crater lake and seepage stream. Quantitative removal of major elements during this interaction has led to relative increase in SiO2 contents. Our silicon isotope data, obtained by HR-MC-ICPMS and reported relative to the NIST RM8546 (=NBS28) standard, show a systematic increase in &δ&&30Si from -0.2‰ (±0.3, 2sd) for unaltered andesites and basalts to +1.5‰ (±0.3, 2sd) for the most altered/silicified rocks. These results demonstrate that silicification induced by pervasive acid alteration is accompanied by significant Si isotope fractionation, so that alterered products become isotopically heavier than the precursor rocks. Despite the observed enrichment in SiO2, the rocks have experienced an overall net loss of silicon upon alteration, if Nb is considered as perfectly immobile. The observed &δ&&30Si values of the alteration products appeared to correlate well with the inferred amounts of silicon loss. These findings would suggest that &28Si is preferentially leached during water-rock interaction, implying that dissolved silica in the ambient lake and stream water is isotopically light. However, layered opaline lake sediments, that are believed to represent precipitates from the silica-saturated water show a conspicuous &30Si-enrichment (+1.2 ± 0.2‰). Because anorganic precipitation is known to discriminate against the heavy isotope (e.g. Basile- Doelsch et al., 2006

  10. Metal speciation and potential bioavailability changes during discharge and neutralisation of acidic drainage water.

    Science.gov (United States)

    Simpson, Stuart L; Vardanega, Christopher R; Jarolimek, Chad; Jolley, Dianne F; Angel, Brad M; Mosley, Luke M

    2014-05-01

    The discharge of acid drainage from the farm irrigation areas to the Murray River in South Australia represents a potential risk to water quality. The drainage waters have low pH (2.9-5.7), high acidity (up to 1190 mg L(-1) CaCO3), high dissolved organic carbon (10-40 mg L(-1)), and high dissolved Al, Co, Ni and Zn (up to 55, 1.25, 1.30 and 1.10 mg L(-1), respectively) that represent the greatest concern relative to water quality guidelines (WQGs). To provide information on bioavailability, changes in metal speciation were assessed during mixing experiments using filtration (colloidal metals) and Chelex-lability (free metal ions and weak inorganic metal complexes) methods. Following mixing of drainage and river water, much of the dissolved aluminium and iron precipitated. The concentrations of other metals generally decreased conservatively in proportion to the dilution initially, but longer mixing periods caused increased precipitation or adsorption to particulate phases. Dissolved Co, Mn and Zn were typically 95-100% present in Chelex-labile forms, whereas 40-70% of the dissolved nickel was Chelex-labile and the remaining non-labile fraction of dissolved nickel was associated with fine colloids or complexed by organic ligands that increased with time. Despite the different kinetics of precipitation, adsorption and complexation reactions, the dissolved metal concentrations were generally highly correlated for the pooled data sets, indicating that the major factors controlling the concentrations were similar for each metal (pH, dilution, and time following mixing). For dilutions of the drainage waters of less than 1% with Murray River water, none of the metals should exceed the WQGs. However, the high concentrations of metals associated with fine precipitates within the receiving waters may represent a risk to some aquatic organisms. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  12. Acid drainages of the pyritic sterile from the Pocos de Caldas uranium mine: environmental interpretation and implications

    International Nuclear Information System (INIS)

    Souza, Vicente Paulo de

    1995-12-01

    Considering the planned closure of the first uranium mine and milling plant operating in Brazil, located in the Pocos de Caldas Plateau, in the State of Minas Gerais, in the next two years, there is the need to obtain basic information for its decommissioning. Special attention has been directed to the following critical areas: open pit, tailing, dam and waste rock piles, because these are the main sources of acid drainage generation. These waters cannot be allowed to flow in the external environment because in addition to sulphuric acid, there is a number of elements in concentration above those allowed by regulations. Among the waste piles (bota-foras BF) two of them BF-4 and BF-8, are in a process of acid generation, thus requiring more attention. The objective of this work was to simulate at the laboratory scale the oxidation and the reduction zones of BF-4. The experiments were conducted in acrylic columns, where the waste sample was kept under aerated and saturated conditions, in different columns. The control of the chemical (solubilized chemical species), physico-chemical (redox potential, pH, conductivity) and biological (bacterial activity) parameters has been carried out on the acid solutions generated by the chemical and biological reactions that occur at the waste. Although the results refer to a four month period, some relevant points can be highlighted, which will serve as a basis for further research. The mineralogical characterization identified the existence of other sulphides associated to pyrite with lower oxidation potential than the latter. The results obtained with the biological characterization for the two conditions studied revealed that the bacterial activity is more intense in the region in contact with air, than in saturated region. (author)

  13. Macroinvertebrate community response to acid mine drainage in rivers of the High Andes (Bolivia)

    International Nuclear Information System (INIS)

    Van Damme, Paul Andre; Hamel, Caroli; Ayala, Alfredo; Bervoets, Lieven

    2008-01-01

    Several High Andes Rivers are characterized by inorganic water pollution known as acid mine drainage (AMD). The aim of this study was to assess the relationship between metal concentrations in the sediments and the macroinvertebrate communities in two river basins affected by AMD. In general, the taxon diversity of the macroinvertebrate community at the family level was low. The concentrations of Cd, Cu, Zn, Pb and Ni at mining sites were higher than at unpolluted sites. The pH of the water was alkaline (7.0-8.5) in unpolluted sites, whereas it dropped to very low values (<3) at mining sites. Redundancy Analysis (RDA) showed that pH was the best predictor of macroinvertebrate community richness. The number of macroinvertebrate families decreased gradually with increasing acidity, both in pools and riffles, though it is suggested that riffle communities were more affected because they are in closer contact with the acid water. - Community response to AMD

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    Highlights: • Acid mine drainage (AMD) is an important environmental concern. • Remediation through biological sulfate reduction and metal recovery can be applied for AMD. • Microbial community composition has a major impact on the performance of bioreactors to treat AMD. • Acidophilic SRB are strongly influenced by proton, sulfide and organic acids concentration. - Abstract: 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Andrea, Irene, E-mail: irene.sanchezandrea@wur.nl [Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen (Netherlands); Sanz, Jose Luis [Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Bijmans, Martijn F.M. [Wetsus, Centre of Sustainable Water Technology, P.O. Box 1113, 8900 CC Leeuwarden (Netherlands); Stams, Alfons J.M. [Laboratory of Microbiology, Wageningen University, Dreijenplein 10, 6703 HB Wageningen (Netherlands); IBB – Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, 4710-057 Braga (Portugal)

    2014-03-01

    Highlights: • Acid mine drainage (AMD) is an important environmental concern. • Remediation through biological sulfate reduction and metal recovery can be applied for AMD. • Microbial community composition has a major impact on the performance of bioreactors to treat AMD. • Acidophilic SRB are strongly influenced by proton, sulfide and organic acids concentration. - Abstract: 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.

  17. Haematological and physiological responses of brook charr, to untreated and limestone-neutralized acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Cole, M.B.; Arnold, D.E.; Watten, B.J.; Krise, W.F. [ABR Inc, Forest Grove, OR (USA). Environmental Research and Services

    2001-07-01

    Brook charr, Salvelinus fontinalis, exhibited depressed plasma sodium and elevated plasma glucose concentrations in untreated acid mine drainage effluent (AMD), at two dilutions. Plasma sodium and glucose concentrations remained stable in treated AMD, pulsed, fluidized beds of limestone and carbon-dioxide pre-treatment of influent, and in AMD-free water. Results indicate that effluents produced by this treatment system were not toxic to these fish, despite still containing moderate concentrations of manganese (3-4 mg l{sup 1} following dilution in exposure systems), and provide justification for field deployment and further biological testing of this treatment in the field.

  18. Persistence of Metal-rich Particles Downstream Zones of Acid Drainage Mixing in Andean Rivers

    Science.gov (United States)

    Pasten, P.; Montecinos, M.; Guerra, P. A.; Bonilla, C. A.; Escauriaza, C. R.; Dabrin, A.; Coquery, M.

    2016-12-01

    The Andes mountain range provides the setting for watersheds with high natural background of metals and for mining operations that enhance contaminant mobilization, notably in Northern and Central Chile. Dissolved and solid metal species are actively transported by streams to the Pacific Ocean from area and point sources, like acid drainage. We examine the response of metal rich particle suspensions downstream zones of mixing where shifts in the chemical environment occur. We propose a conceptual model which is used to analyze the fate of copper in the upper Mapocho watershed. The main source of copper is the Yerba Loca river, a naturally impacted stream with pH ranging from 3 to 7 and high concentrations of Cu (0.8 - 6.3 mg/L), Al (1.3 - 7.6 mg/L) and Fe (0.4 - 4.2 mg/L). Steep chemical shifts occur after the confluences with the San Francisco and the Molina rivers. We characterized stream chemistry, hydrological variables and suspended particles, including particle size distribution (PSD), turbidity, and total suspended solids. A marked seasonal behavior was observed, with a higher total Cu flux during smelting periods and a shift towards the dissolved phase during summer. When acid drainage is discharged into a receiving stream, incomplete mixing occurs thereby promoting the formation of a range of metal-rich solids with a characteristic PSD. Similarly, areas of chemical heterogeneity control the partition of metals associated to suspended geomaterials coming from bank and slope erosion. A highly dynamic process ensues where metastable phases shift to new equilibria as fully mixed conditions are reached. Depending on the reaction kinetics, some particles persist despite being exposed to thermodynamically unfavorable chemical environments. The persistence of metal-rich particles downstream zones of acid drainage mixing is important because it ultimately controls the flux of metals being delivered to the ocean by watersheds impacted by acid drainage. Funding from

  19. Application of the novel mill tailings agglomeration technology for prevention of acid mine drainage

    International Nuclear Information System (INIS)

    Amaratunga, L.M.

    1994-01-01

    Acid generation and subsequent liberation of heavy metals results from the surface disposal of sulfide mineral bearing mill tailings. Most Canadian base metals such as Ni, Cu, Zn, and Pb, as well as uranium and precious metal milling operations are producers of reactive mill tailings containing the major sulfide gangue minerals such as pyrite, pyrrhotite and arsenopyrites. A novel disposal technology by cold-bond tailings agglomeration process (CBTA) is currently being developed at Laurentian University. This process has been adapted to prevent acid mine drainage from reactive mill tailings. A preliminary study was undertaken to evaluate the application of the concept of agglomeration of reactive mill tailings using various alkaline binders and incorporating suitable chemical additives. The binders and additives are selected for their effectiveness in the prevention or retardation of the initial chemical and biochemical oxidation reactions of sulfide mineral leading to acid generation. Following a cold-bond, cold curing tailings agglomeration process, various types and dosages of chemical binders and their additives were employed. The additives under investigation were lime, sodium lauryl sulfate, potassium phosphate dibasic, sodium chloride and sodium benzoate. Some of these chemicals are well known acid neutralizers and others are inexpensive anionic surfactants, detergents and fertilizers acting as bactericides. Most of these additives have been reported in the literature as effective chemical agents used in the prevention and control of acid mine drainage from sulfide minerals. The paper also presents a leachate study to investigate the acid generation potential from each batch of reactive tailings agglomerates containing various binders and non-toxic additives

  20. Concentration-Discharge Behavior of Contaminants in a Stream Impacted by Acid Mine Drainage

    Science.gov (United States)

    Shaw, M. E.; Klein, M.; Herndon, E.

    2017-12-01

    Acid mine drainage (AMD) has severely degraded streams throughout the Appalachian coal region of the United States. AMD occurs when pyrite contained in coal is exposed to water and air during mining activities and oxidized to release high concentrations of sulfate, metals, and acidity into water bodies. Little is known about the concentration-discharge (CQ) relationships of solutes in AMD-impacted streams due to the complicated nature of acid mine drainage systems. For example, streams may receive inputs from multiple sources that include runoff, constructed treatment systems, and abandoned mines that bypass these systems to continue to contaminate the streams. It is important to understand the CQ relationships of contaminants in AMD-impacted streams in order to elucidate contaminant sources and to predict effects on aquatic ecosystems. Here, we study the CQ behaviors of acid and metals in a contaminated watershed in northeastern Ohio where limestone channels have been installed to remediate water draining from a mine pool into the stream. Stream chemistry was measured in samples collected once per day or once per hour during storm events, and stream flow was measured continuously at the watershed outlet. Increases in stream velocity during storm events resulted in an increase in pH (from 3 to 6) that subsequently decreased back to 3 as flow decreased. Additionally, Fe and Mn concentrations in the stream were high during baseflow (7 and 15 mg/L, respectively) and decreased with increasing discharge during storm events. These results indicate that the treatment system is only effective at neutralizing stream acidity and removing metals when water flow through the limestone channel is continuous. We infer that the acidic and metal-rich baseflow derives from upwelling of contaminated groundwater or subsurface flow from a mine pool. Ongoing studies aim to isolate the source of this baseflow contamination and evaluate the geochemical transformations that occur as it

  1. Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids.

    Science.gov (United States)

    Xu, Ren-kou; Zhu, Yong-guan; Chittleborough, David

    2004-01-01

    Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the pKa values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was notcorrelated with pKa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

  2. Biochemical process for the removal of uranium from acid mine drainages

    International Nuclear Information System (INIS)

    Roig, M.G.; Manzano, T.; Diaz, M.

    1997-01-01

    A biochemical process has been assessed with a view to removing heavy metals from acid mine drainages in which the metal cation removed is accumulated in situ as insoluble metal phosphate on the surface of Citrobacter N 14 cells (Roig et al., 1995). The localized presence of inorganic phosphate (P i ) is brought about via the hydrolysis of a ''donor'' organic phosphate added to the solution of metals with precipitation as MHPO 4 bound to the cells. The present work explores the potential of immobilized Citrobacter biomass for the recovery of uranium from the acid drainage waters of the ''Faith'' mine exploited by ENUSA (Ciudad Rodrigo, Salamanca). A physicochemical characterization of the acid waste-water from ENUSA was carried out and flow injection analysis methods for the determination of uranium and P i in such water were developed and improved. The efficiencies of chemical precipitation (by the addition of P i to the acid water) with regard to bioinsolubilization (supplementing the water with an organic phosphate that is (later) hydrolysed to P i ) were investigated and compared. Additionally, the efficiency of chemical and biochemical precipitation as phosphates of uranium present in ENUSA acid drainage water were assessed. Furthermore, the relative importance of chemical precipitation (by the addition of P i to the acid water) with regard to bioinsolubilization (supplementing the water with an organic phosphate that is (later) hydrolysed to P i plus alcohol) was established. To do so, a series of mass balances for chemical precipitation and for bioinsolubilization of the metal phosphate was performed. Once the efficiency of the bioprocess as regards the removal of uranium when glycerol-2-phosphate is used as a substrate had been determined, a major question was forthcoming: the search for an efficient and much more economical substrate for the process. In this sense, sodium tripolyphosphate, one of the main components of many formulations of commercial

  3. Profiles of bile acids and their glucuronide and sulphate conjugates in the serum, urine and bile from patients undergoing bile drainage.

    OpenAIRE

    Takikawa, H; Beppu, T; Seyama, Y

    1985-01-01

    Bile acid profiles in serum, urine, and bile from patients undergoing bile drainage and the changes of serum bile acids after bile drainage were studied. Bile acids were separated into non-glucuronidate-non-sulphate, glucuronidated, and sulphated fractions and were measured by mass fragmentography using conjugates of deuterium labelled bile acids as internal standards. Glucuronidated and sulphated bile acids contribute 14-32% and 16-44% of serum bile acids, 4-11% and 61-82% of urine bile acid...

  4. Net Acid Production, Acid Neutralizing Capacity, and Associated Mineralogical and Geochemical Characteristics of Animas River Watershed Igneous Rocks Near Silverton, Colorado

    Science.gov (United States)

    Yager, Douglas B.; Choate, LaDonna; Stanton, Mark R.

    2008-01-01

    This report presents results from laboratory and field studies involving the net acid production (NAP), acid neutralizing capacity (ANC), and magnetic mineralogy of 27 samples collected in altered volcanic terrain in the upper Animas River watershed near Silverton, Colo., during the summer of 2005. Sampling focused mainly on the volumetrically important, Tertiary-age volcanic and plutonic rocks that host base- and precious-metal mineralization in the study area. These rocks were analyzed to determine their potential for neutralization of acid-rock drainage. Rocks in the study area have been subjected to a regional propylitic alteration event, which introduced calcite, chlorite (clinochlore), and epidote that have varying amounts and rates of acid neutralizing capacity (ANC). Locally, hydrothermal alteration has consumed any ANC and introduced minerals, mainly pyrite, that have a high net acid production (NAP). Laboratory studies included hydrogen pyroxide (H2O2) acid digestion and subsequent sodium hydroxide (NaOH) titration to determine NAP, and sulfuric acid (H2SO4) acid titration experiments to determine ANC. In addition to these environmental rock-property determinations, mineralogical, chemical, and petrographic characteristics of each sample were determined through semiquantitative X-ray diffractometry (Rietveld method), optical mineralogy, wavelength dispersive X-ray fluorescence, total carbon-carbonate, and inductively coupled plasma?mass spectrometric analysis. An ANC ranking was assigned to rock samples based on calculated ANC quantity in kilograms/ton (kg/t) calcium carbonate equivalent and ratios of ANC to NAP. Results show that talus near the southeast Silverton caldera margin, composed of andesite clasts of the Burns Member of the Silverton Volcanics, has the highest ANC (>100 kg/t calcium carbonate equivalent) with little to no NAP. The other units found to have moderate to high ANC include (a) andesite lavas and volcaniclastic rocks of the San Juan

  5. Acidity decay of above-drainage underground mines in West Virginia.

    Science.gov (United States)

    Mack, B; McDonald, L M; Skousen, J

    2010-01-01

    Acidity of water from abandoned underground mines decreases over time, and the rate of decrease can help formulate remediation approaches and treatment system designs. The objective of this study was to determine an overall acidity decay rate for above-drainage underground mines in northern West Virginia from a large data set of mines that were closed 50 to 70 yr ago. Water quality data were obtained from 30 Upper Freeport and 7 Pittsburgh coal seam mines in 1968, 1980, 2000, and 2006, and acidity decay curves were calculated. The mean decay constant, k, for Upper Freeport mines was 2.73 x 10(-2) yr(-1), with a 95% confidence interval of +/- 0.0052, whereas the k value for Pittsburgh mines was not significantly different at 4.26 x 10(-2) yr(-1) +/- 0.017. Acidity from the T&T mine, which was closed 12 yr ago, showed a k value of 11.25 x 10(-2) yr(-1). This higher decay rate was likely due to initial flushing of accumulated metal salts on reaction surfaces in the mine, rapid changes in mine hydrology after closure, and treatment. Although each site showed a specific decay rate (varying from 0.04 x 10(-2) yr(-1) to 13.1 x 10(-2) yr(-1)), the decay constants of 2.7 x 10(-2) yr(-1) to 4.3 x 10(-2) yr(-1) are useful for predicting water quality trends and overall improvements across a wide spectrum of abandoned underground mines. We found first-order decay models improve long-term prediction of acidity declines from above-drainage mines compared with linear or percent annual decrease models. These predictions can help to select water treatment plans and evaluate costs for these treatments over time.

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

    Science.gov (United States)

    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

  7. Biological manganese removal from acid mine drainage in constructed wetlands and prototype bioreactors.

    Science.gov (United States)

    Hallberg, Kevin B; Johnson, D Barrie

    2005-02-01

    Mine drainage waters vary considerably in the range and concentration of heavy metals they contain. Besides iron, manganese is frequently present at elevated concentrations in waters draining both coal and metal mines. Passive treatment systems (aerobic wetlands and compost bioreactors) are designed to remove iron by biologically induced oxidation/precipitation. Manganese, however, is problematic as it does not readily form sulfidic minerals and requires elevated pH (>8) for abiotic oxidation of Mn (II) to insoluble Mn (IV). As a result, manganese removal in passive remediation systems is often less effective than removal of iron. This was found to be the case at the pilot passive treatment plant (PPTP) constructed to treat water draining the former Wheal Jane tin mine in Cornwall, UK, where effective removal of manganese occurred only in one of the three rock filter components of the composite systems over a 1-year period of monitoring. Water in the two rock filter systems where manganese removal was relatively poor was generally system. These differences in water chemistry and manganese removal were due to variable performances in the compost bioreactors that feed the rock filter units in the composite passive systems at Wheal Jane. An alternative approach for removing soluble manganese from mine waters, using fixed bed bioreactors, was developed. Ferromanganese nodules (about 2 cm diameter), collected from an abandoned mine adit in north Wales, were used to inoculate the bioreactors (working volume ca. 700 ml). Following colonization by manganese-oxidizing microbes, the aerated bioreactor catalysed the removal of soluble manganese, via oxidation of Mn (II) and precipitation of the resultant Mn (IV) in the bioreactor, in synthetic media and mine water from the Wheal Jane PPTP. Such an approach has potential application for removing soluble Mn from mine streams and other Mn-contaminated water courses.

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

    Science.gov (United States)

    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...

  9. Pyrolusite Process® to remove acid mine drainage contaminants from Kimble Creek in Ohio: A pilot study

    Science.gov (United States)

    Shiv Hiremath; Kirsten Lehtoma; Mike Nicklow; Gary. Willison

    2013-01-01

    The Kimble Creek abandoned coal mine site, located on Wayne National Forest in southeastern Ohio, is among several abandoned coal mine sites that have been responsible for the acid mine drainage (AMD) polluting ground and surface water. Materials released by AMD include iron, aluminum, manganese, other hazardous substances, and acidity that are harmful to aquatic life...

  10. Rare Moss-Built Microterraces in a High-Altitude, Acid Mine Drainage-Polluted Stream (Cordillera Negra, Peru)

    NARCIS (Netherlands)

    Sevink, J.; Verstraten, J.M.; Kooijman, A.M.; Loayza-Muro, R.A.; Hoitinga, L.; Palomino, E.J.; Jansen, B.

    2015-01-01

    The Rio Santiago in the Cordillera Negra of Peru is severely contaminated by acid mine drainage in its headwaters. In a strongly acid stream, at about 3800 m above sea level (masl), microterraces were found with terrace walls built up of dead moss, with encrustations and interstitial fine, creamy

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

    Science.gov (United States)

    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...

  12. Enhancing the natural removal of As in a reactive fluvial confluence receiving acid drainage

    Science.gov (United States)

    Abarca, M. I.; Arce, G.; Montecinos, M.; Guerra, P. A.; Pasten, P.

    2014-12-01

    Fluvial confluences are natural reactors that can determine the fate of contaminants in watersheds receiving acid drainage. Hydrological, hydrodynamic and chemical factors determine distinct conditions for the formation of suspended particles of iron and aluminum oxyhydroxides. The chemical and physical properties of these particle assemblages (e.g. particle size, chemical composition) can vary according to inflow mixing ratios, hydrodynamic velocity profiles, and chemical composition of the flows mixing at the confluence. Due to their capacity to sorb metals, it is important to identify the optimal conditions for removing metals from the aqueous phase, particularly arsenic, a contaminant frequently found in acid drainage. We studied a river confluence in the Lluta watershed, located in the arid Chilean Altiplano. We performed field measurements and laboratory studies to find optimal mixing ratio for arsenic sorption onto oxyhydroxide particles at the confluence between the Azufre (pH=2, As=2 mg/L) and the Caracarani river (pH=8, Ascontaminants. An analogy between confluences and coagulation-flocculation-sedimentation drinking water plants could be used to engineer such intervention.Acknowledgements: Proyecto Fondecyt 1130936 and Proyecto CONICYT FONDAP 15110020

  13. Ion activity and distribution of heavy metals in acid mine drainage polluted subtropical soils

    International Nuclear Information System (INIS)

    Li Yongtao; Becquer, Thierry; Dai Jun; Quantin, Cecile; Benedetti, Marc F.

    2009-01-01

    The oxidative dissolution of mine wastes gives rise to acidic, metal-enriched mine drainage (AMD) and has typically posed an additional risk to the environment. The poly-metallic mine Dabaoshan in South China is an excellent test site to understand the processes affecting the surrounding polluted agricultural fields. Our objectives were firstly to investigate metal ion activity in soil solution, distribution in solid constituents, and spatial distribution in samples, secondly to determine dominant environment factors controlling metal activity in the long-term AMD-polluted subtropical soils. Soil Column Donnan Membrane Technology (SC-DMT) combined with sequential extraction shows that unusually large proportion of the metal ions are present as free ion in the soil solutions. The narrow range of low pH values prevents any pH effects during the binding onto oxides or organic matter. The differences in speciation of the soil solutions may explain the different soil degradation observed between paddy and non-paddy soils. - First evidence of the real free metal ion concentrations in acid mine drainage context in tropical systems

  14. Insights into the diversity of eukaryotes in acid mine drainage biofilm communities.

    Science.gov (United States)

    Baker, Brett J; Tyson, Gene W; Goosherst, Lindsey; Banfield, Jillian F

    2009-04-01

    Microscopic eukaryotes are known to have important ecosystem functions, but their diversity in most environments remains vastly unexplored. Here we analyzed an 18S rRNA gene library from a subsurface iron- and sulfur-oxidizing microbial community growing in highly acidic (pH morphological characterization. Results revealed that the populations vary significantly with the habitat and no group is ubiquitous. Surprisingly, many of the eukaryotic lineages (with the exception of the APC) are closely related to neutrophiles, suggesting that they recently adapted to this extreme environment. Molecular analyses presented here confirm that the number of eukaryotic species associated with the acid mine drainage (AMD) communities is low. This finding is consistent with previous results showing a limited diversity of archaea, bacteria, and viruses in AMD environments and suggests that the environmental pressures and interplay between the members of these communities limit species diversity at all trophic levels.

  15. Physico-chemical processes in acid mine drainage in coal mining, south Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Campaner, Veridiana Polvani; Luiz-silva, Wanilson. [Universidade Estadual de Campinas, Campinas (Brazil)

    2009-07-01

    Acid mine drainage generated from coal mine showed a pH of 3.2, high concentrations of SO{sub 4}{sup 2-}, Al, Fe, Mn, Zn and minor As, Cd, Co, Cr, Cu, Ni and Pb. The major reduction in the concentration occurred for Al, As, Cr, Fe and Pb after the treatment with CaO. The evolution of these acid waters within the tributary stream showed decreasing concentration for all soluble constituents, except Al. This natural attenuation was controlled by pH (6.4 to 10.8) as a result of concurrent mixing with tributary stream and reaction with local bedrock that contains limestone. Aluminum increasing concentration during this evolution seems to be related to an input of Al-enriched waters due to the leaching of silicate minerals in alkaline conditions. 47 refs., 3 figs., 3 tabs.

  16. Application of nanofiltration to the treatment of acid mine drainage waters

    International Nuclear Information System (INIS)

    Bastos, Edna T.R.; Barbosa, Celina C.R.; Oliveira, Elizabeth E.M.; Carvalho, Leonel M. de; Pedro Junior, Antonio; Queiroz, Vanessa B.C. de

    2009-01-01

    This study investigated the separation of uranium and other elements in high concentrations from acid mine waters at Caldas Uranium Mining, in the southeast of Brazil, using nanofiltration membranes. Nanofiltrarion is widely used in water treatment due to the lower energy requirements and higher yields than reverse osmosis. Separation characteristics are dependent on both the molecular size and charge of the dissolved species in the feed solution as well as membrane properties. In this investigation the potential of nanofiltration to removed dissolved species like uranium from acid mine water drainage was measured. Two composite aromatic polyamide commercially membranes of FilmTec/Dow were tested and it found that uranium rejections of greater than 90% and also showed potential for the separation of aluminum and manganese. (author)

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

    Science.gov (United States)

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

    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 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.

  18. Metal cycling during sediment early diagenesis in a water reservoir affected by acid mine drainage

    DEFF Research Database (Denmark)

    Torres, Ester; Ayora, Carlos; Canovas, C. R.

    2013-01-01

    The discharge of acid mine drainage (AMD) into a reservoir may seriously affect the water quality. To investigate the metal transfer between the water and the sediment, three cores were collected from the Sancho Reservoir (Iberian Pyrite Belt, SW Spain) during different seasons: turnover event......; oxic, stratified period; anoxic and under shallow perennially oxic conditions. The cores were sliced in an oxygen-free atmosphere, after which pore water was extracted by centrifugation and analyzed. A sequential extraction was then applied to the sediments to extract the water-soluble, monosulfide......, low crystallinity Fe(III)-oxyhydroxide, crystalline Fe(III)-oxide, organic, pyrite and residual phases. The results showed that, despite the acidic chemistry of the water column (pH

  19. 17,21-Secohopanoic acids, 25-norhopanoic acids, and 28-norhopanoic acids in source rocks and crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Xueming Pan; Philp, R.P. [University of Oklahoma, Norman, OK (United States). School of Geology and Geophysics

    2006-09-15

    The presence of three families of hopanoic acids, 17,21-secohopanoic acids, 25-norhopanoic acids, and 28-norhopanoic acids, is discussed. Oils from West Siberia and tar balls from the Seychelles Islands were found to contain relatively high proportions of 17,21-secohopanoic acids. These acids have not been previously reported in any oils or source rocks. A heavily biodegraded West Siberian oil, was found to contain an homologous series of 25-norhopanoic acids co-occurring with the 25-norhopanes as previously reported in only a small number of oils from Campos Basin, Brazil. 28-Norhopanoic acids have been reported in various sediments and extracts of the Monterey Shale, but in this study their occurrence has been extended to oils, degraded oils, and tar balls sourced from the Monterey Shale. The primary purpose herein is to report the occurrence of these acids and possible relationships between the acids and corresponding hydrocarbons. (Author)

  20. The effects of ferulic acid on the pharmacokinetics of warfarin in rats after biliary drainage

    Directory of Open Access Journals (Sweden)

    Li H

    2016-07-01

    Full Text Available Haigang Li,1,2 Yang Wang,1 Rong Fan,1 Huiying Lv,3 Hua Sun,4 Haitang Xie,4 Tao Tang,1 Jiekun Luo,1 Zian Xia1 1Department of Integrated Traditional Chinese and Western Medicine, Laboratory of Ethnopharmacology, Xiangya Hospital, Central South University, 2Department of Pharmacy, Changsha Medical University, 3Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha, 4Anhui Provincial Centre for Drug Clinical Evaluation, Yijishan Hospital of Wannan Medical College, Wuhu, People’s Republic of China Abstract: According to previous research studies, warfarin can be detected in human bile after oral administration. Ferulic acid (FA is the main bioactive component of many Chinese herbs for the treatment of cardiovascular disease. To elucidate the effects of FA on the pharmacokinetics of warfarin in rats after biliary drainage is necessary. Twenty rats were randomly divided into four groups: Group 1 (WN: healthy rats after the administration of warfarin sodium, Group 2 (WO: a rat model of biliary drainage after the administration of warfarin sodium, Group 3 (WFN: healthy rats after the administration of warfarin sodium and FA, and Group 4 (WFO: a rat model of biliary drainage after the administration of warfarin sodium and FA. Blood samples were collected at different time points after administration. The concentrations of blood samples were determined by ultraperformance liquid chromatography–tandem mass spectrometry. Comparisons between groups were performed according to the main pharmacokinetic parameters calculated by the DAS 2.1.1 software. The pharmacokinetic parameters showed a significant difference between the WN and WO groups, the WO group showed a decrease of 51% and 41.6% in area under the curve from 0 to time (AUC0–t and peak plasma concentration (Cmax, respectively, whereas time to Cmax (Tmax was delayed 3.27 folds. There were significant differences between the WFO and WFN groups, the WFO

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

    Science.gov (United States)

    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 water column. However extrapolation of this concept to a field

  2. Vascular riffle flora of Appalachian streams: the ecology and effects of acid mine drainage on Justificia americana (L. ) Vahl

    Energy Technology Data Exchange (ETDEWEB)

    Koryak, M.; Reilly, R.J.

    1984-06-01

    Justicia americana is a stout-based colonial plant, abundant in most of the larger, low to moderate gradient streams of the upper Ohio River basin. The distribution of J. americana is related to acid drainage from bituminous coal mining operations in the upper Ohio River drainage basin. Possible fluvial and biological consequences of the colonization or absence of Justicia are considered. Luxuriant growths were noted on gravel bars and riffles of larger, unpolluted streams in the basin. Acid mine drainage severely depresses the growth of the plant, leaving gravel shoals and riffles in the acid streams either barren or dominated by other emergent species. Particular among these new species is Elecocharis acicularis. The elimination of J. americana from suitable habitat adversely affects channel morphology, substrate composition, general aesthetic quality and aquatic stream life in the region. 16 references, 2 figures, 3 tables.

  3. Fate of the naturally occurring radioactive materials during treatment of acid mine drainage with coal fly ash and aluminium hydroxide.

    Science.gov (United States)

    Madzivire, Godfrey; Maleka, Peane P; Vadapalli, Viswanath R K; Gitari, Wilson M; Lindsay, Robert; Petrik, Leslie F

    2014-01-15

    Mining of coal is very extensive and coal is mainly used to produce electricity. Coal power stations generate huge amounts of coal fly ash of which a small amount is used in the construction industry. Mining exposes pyrite containing rocks to H2O and O2. This results in the oxidation of FeS2 to form H2SO4. The acidic water, often termed acid mine drainage (AMD), causes dissolution of potentially toxic elements such as, Fe, Al, Mn and naturally occurring radioactive materials such as U and Th from the associated bedrock. This results in an outflow of AMD with high concentrations of sulphate ions, Fe, Al, Mn and naturally occurring radioactive materials. Treatment of AMD with coal fly ash has shown that good quality water can be produced which is suitable for irrigation purposes. Most of the potentially toxic elements (Fe, Al, Mn, etc) and substantial amounts of sulphate ions are removed during treatment with coal fly ash. This research endeavours to establish the fate of the radioactive materials in mine water with coal fly ash containing radioactive materials. It was established that coal fly ash treatment method was capable of removing radioactive materials from mine water to within the target water quality range for drinking water standards. The alpha and beta radioactivity of the mine water was reduced by 88% and 75% respectively. The reduced radioactivity in the mine water was due to greater than 90% removal of U and Th radioactive materials from the mine water after treatment with coal fly ash as ThO2 and UO2. No radioisotopes were found to leach from the coal fly ash into the mine water. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. The use of constructed wetlands in the treatment of acid mine drainage

    International Nuclear Information System (INIS)

    Perry, A.; Kleinmann, R.L.P.

    1991-01-01

    US government regulations require that all effluents from industrial operations, including mining, meet certain water quality standards. Constructed wetlands have proven to be useful in helping to attain those standards. Application of this biotechnology to mine water drainage can reduce water treatment costs and improve water quality in streams and rivers adversely affected by acidic mine water drainage from abandoned mines. Over 400 constructed wetland water treatment systems have been built on mined lands largely as a result of research by the US Bureau of Mines. Wetlands are passive biological treatment systems that are relatively inexpensive to construct and require minimal maintenance. Chemical treatment costs are reduced sufficiently to repay the cost of construction in less than a year. The mine waste water is typically treated in a series of excavated ponds that resemble small marsh areas. The ponds are engineered to facilitate bacterial oxidation of iron. Ideally, the water then flows through a composted organic substrate supporting a population of sulphate-reducing bacteria which raises the pH. Constructed wetlands in the USA are described - their history, functions, construction methodologies, applicabilities, limitations and costs. (author). 26 refs, 2 figs

  5. The use of constructed wetlands in the treatment of acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Perry, A [Department of the Interior, Washington, DC (United States). Bureau of Mines; Kleinmann, R L.P. [Department of the Interior, Pittsburgh, PA (United States). Bureau of Mines

    1991-08-01

    US government regulations require that all effluents from industrial operations, including mining, meet certain water quality standards. Constructed wetlands have proven to be useful in helping to attain those standards. Application of this biotechnology to mine water drainage can reduce water treatment costs and improve water quality in streams and rivers adversely affected by acidic mine water drainage from abandoned mines. Over 400 constructed wetland water treatment systems have been built on mined lands largely as a result of research by the US Bureau of Mines. Wetlands are passive biological treatment systems that are relatively inexpensive to construct and require minimal maintenance. Chemical treatment costs are reduced sufficiently to repay the cost of construction in less than a year. The mine waste water is typically treated in a series of excavated ponds that resemble small marsh areas. The ponds are engineered to facilitate bacterial oxidation of iron. Ideally, the water then flows through a composted organic substrate supporting a population of sulphate-reducing bacteria which raises the pH. Constructed wetlands in the USA are described - their history, functions, construction methodologies, applicabilities, limitations and costs. (author). 26 refs, 2 figs.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Study of weathering velocity of rocks with uranium as a natural tracer. Application to two drainage basins of the north-east of Brazil

    International Nuclear Information System (INIS)

    Costa Pinto Moreira Nordemann, L.M. da.

    1977-01-01

    Study on rock weathering rate, i.e. rock-soil interface formation, by measuring the elements dissolved in river waters. These elements are used as natural tracers. This work has been carried out in the drainage basin of Preto and Salgado Rivers, in Brazil. Conventional elements, sodium, potassium, calcium and magnesium have been utilized first and all dissolved salts have been used as natural tracers to allow comparison with other scientific works. Then, uranium has been used because it is not found in rain waters so that corrections are not necessary and because its abundance can be measured by α and γ spectrometry, and the 234 U/ 238 U ratio obtained, 234 U being more rapidly dissolved during weathering. Another reason is that no interaction occurs between uranium and the biomass. It is then possible to find a geochemical balance for this area [fr

  8. Strategies for Reduced Acid and Metalliferous Drainage by Pyrite Surface Passivation

    Directory of Open Access Journals (Sweden)

    Gujie Qian

    2017-03-01

    Full Text Available Acid and metalliferous drainage (AMD is broadly accepted to be a major global environmental problem facing the mining industry, requiring expensive management and mitigation. A series of laboratory-scale kinetic leach column (KLC experiments, using both synthetic and natural mine wastes, were carried out to test the efficacy of our pyrite passivation strategy (developed from previous research for robust and sustainable AMD management. For the synthetic waste KLC tests, initial treatment with lime-saturated water was found to be of paramount importance for maintaining long-term circum-neutral pH, favourable for the formation and preservation of the pyrite surface passivating layer and reduced acid generation rate. Following the initial lime-saturated water treatment, minimal additional alkalinity (calcite-saturated water was required to maintain circum-neutral pH for the maintenance of pyrite surface passivation. KLC tests examining natural potentially acid forming (PAF waste, with much greater peak acidity than that of the synthetic waste, blended with lime (≈2 wt % with and without natural non-acid-forming (NAF waste covers, were carried out. The addition of lime and use of NAF covers maintained circum-neutral leachate pH up to 24 weeks. During this time, the net acidity generated was found to be significantly reduced by the overlying NAF cover. If the reduced rate of acidity production from the natural PAF waste is sustained, the addition of smaller (more economically-feasible amounts of lime, together with application of NAF wastes as covers, could be trialled as a potential cost-effective AMD mitigation strategy.

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Physiological and behavioral response of stonefly nymphs to enhanced limestone treatment of acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Cole, M.B.; Arnold, D.E.; Watten, B.J. [ABR Inc., PO Box 249, OR (USA). Environmental Research and Services

    2001-07-01

    A new acid mine drainage (AMD) treatment system uses pulsed, fluidized beds of limestone, and carbon dioxide pretreatment of influent AMD to enhance limestone neutralization of AMD. Laboratory studies were carried out to evaluate the behavior and physiology of larval stoneflies (Pteronarcys proteus, Plecoptera) exposed to effluents produced by the treatment system. Survival, sodium balance, drift, and feeding responses by P. proteus to treated and untreated AMD were examined. P. proteus nymphs exhibited significant losses of whole body sodium in exposures to untreated AMD. Nymphs exposed to treated effluents experienced no loss of whole-body sodium. No significant differences in feeding or drift behavior occurred between nymphs exposed to treated effluents and those exposed to AMD-free controls. The treatment system, with and without CO{sub 2} pretreatment, provided water that was not toxic to the test animals, and that allowed normal behavioral and physiological function.

  11. Iron oxides in acid mine drainage environments and their association with bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Ferris, F G; Tazaki, K; Fyfe, W S

    1989-01-20

    A variety of iron oxides were identified by X-ray diffraction in sediments receiving acid drainage from mine tailing and coal refuse impoundments. Small amounts of goethite and hematite were found in the sediment samples. However, the major iron oxide species was ferrihydrite which gave diffuse diffraction bands at angles corresponding to d2.5, 2.2 and 1.5 Angstrom. Main core line binding energies in Fe (2p) and O (1s) X-ray photoelectron spectra were consistent with the hydrous nature and predominance of ferrihydrite. Electron microscopy and energy-dispersive X-ray spectroscopy also showed that individual bacterial cells promoted the development of iron oxide mineralization. The bacterial associated iron oxides were similar to those in the bulk sediment samples, and exhibited structures conforming to the presence of chemisorbed sulfate or silicate anions. 23 refs., 3 figs.

  12. The Positive Environmental Contribution of Jarosite by Retaining Lead in Acid Mine Drainage Areas

    Directory of Open Access Journals (Sweden)

    Teresa Pereira da Silva

    2011-05-01

    Full Text Available Jarosite, KFe3(SO42(OH6, is a secondary iron sulphate often found in acid mine drainage (AMD environments, particularly in mining wastes from polymetallic sulphide ore deposits. Despite the negative environmental connotation usually ascribed to secondary sulphate minerals due to the release of hazardous elements to aquifers and soils, jarosite acts as an efficient remover and immobilizer of such metals, particularly lead. The mineral chemistry of jarosite is reviewed and the results of a Fe K-edge XANES (X-Ray Absorption Near-Edge Structure study of K-, Na- and Pb-jarosite are described and discussed within the context of the abandoned old mines of São Domingos and Aljustrel located in southern Portugal, in the Iberian Pyrite Belt (IPB.

  13. Water table lowering to improve excavation performance and to reduce acid mine drainage

    International Nuclear Information System (INIS)

    Koppe, J.C.; Costa, J.F.; Laurent, O. Jr.

    1995-01-01

    This paper analyses the water table level fluctuations using wells located adjacent to the stripping cuts at the Butia-Leste coal mine, southernmost of Brazil. Piezometers monitored the water table fluctuations. Geological mapping provided additional information aiding the interpretation of the results. A contouring software was also used as tool to aid the interpretation of the data and the results visualisation. The parameters necessary in selecting the location of the wells and pumping volumes were calculated from the data obtained in the water table lowering tests. The results were used to minimise two main problems: the generation of acid mine drainage and the reduction of the excavation performance of the fleet used in overburden removal. 7 refs., 5 figs., 3 tabs

  14. Acid mine drainage in South Africa: A test of legitimacy theory

    Directory of Open Access Journals (Sweden)

    Boitumelo Loate

    2015-04-01

    Full Text Available There is a large body of international literature which suggests that there is a correlation between organisational legitimacy, the nature and extent of non-financial disclosures in corporate reports, and the society’s awareness of social, governance and environmental concerns. Little studied, however, is corporate reporting in South Africa through the lens of legitimacy theory. This paper addresses this gap by exploring whether local mining companies are providing additional environmental information in their annual or integrated reports following media coverage on acid mine drainage and, if so, to what extent. A review of press articles released by the mining houses also reveals how claims to pragmatic, moral and cognitive legitimacy are employed to mitigate negative publicity. In this way, the paper offers additional material on the role of legitimacy theory for explaining developments in corporate reporting. It also contributes to the limited body of interpretive corporate governance research in a South African context.

  15. Evaluation of layered and mixed passive treatment systems for acid mine drainage.

    Science.gov (United States)

    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.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. - Highlights: • Efflorescent salts from mining areas have a great impact on the environment. • Secondary minerals are influenced by geology, hydrology, biology and climate. • AMD-precipitates samples were analyzed by XRD, SEM, Raman and NIR spectrometry. • The dehydration temperatures

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Buzatu, Andrei, E-mail: andrei.buzatu@uaic.ro [“Alexandru Ioan Cuza” University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi (Romania); Dill, Harald G. [Gottfried Wilhelm Leibniz University, Welfengarten 1 D-30167, Hannover (Germany); Buzgar, Nicolae [“Alexandru Ioan Cuza” University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi (Romania); Damian, Gheorghe [Technical University Cluj Napoca, North University Center of Baia Mare, 62A Dr. Victor Babeş Street, 430083 Baia Mare (Romania); Maftei, Andreea Elena; Apopei, Andrei Ionuț [“Alexandru Ioan Cuza” University of Iaşi, Department of Geology, 20A Carol I Blv., 700505 Iaşi (Romania)

    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. - Highlights: • Efflorescent salts from mining areas have a great impact on the environment. • Secondary minerals are influenced by geology, hydrology, biology and climate. • AMD-precipitates samples were analyzed by XRD, SEM, Raman and NIR spectrometry. • The dehydration temperatures

  19. Novel passive co-treatment of acid mine drainage and municipal wastewater.

    Science.gov (United States)

    Strosnider, William H J; Winfrey, Brandon K; Nairn, Robert W

    2011-01-01

    A laboratory-scale, four-stage continuous-flow reactor system was constructed to test the viability of high-strength acid mine drainage (AMD) and municipal wastewater (MWW) passive co-treatment. Synthetic AMD of pH 2.6 and acidity of 1870 mg L(-1) as CaCO3 equivalent containing a mean 46, 0.25, 2.0, 290, 55, 1.2, and 390 mg L(-1) of Al, As, Cd, Fe, Mn, Pb, and Zn, respectively, was added at a 1:2 ratio with raw MWW from the City of Norman, OK, to the system which had a total residence time of 6.6 d. During the 135-d experiment, dissolved Al, As, Cd, Fe, Mn, Pb, and Zn concentrations were consistently decreased by 99.8, 87.8, 97.7, 99.8, 13.9, 87.9, and 73.4%, respectively, pH increased to 6.79, and net acidic influent was converted to net alkaline effluent. At a wasting rate of 0.69% of total influent flow, the system produced sludge with total Al, As, Cd, Cr, Cu, Fe, Pb, and Zn concentrations at least an order of magnitude greater than the influent mix, which presents a metal reclamation opportunity. Results indicate that AMD and MWW passive co-treatment is a viable approach to use wastes as resources to improve water quality with minimal use of fossil fuels and refined materials.

  20. K-Ar dating on acidic rocks from the Western Aizu District, Fukushima Prefecture

    International Nuclear Information System (INIS)

    Shimada, Ikuro; Ueda, Yoshio

    1979-01-01

    K-Ar age determinations were carried out on twelve samples of various acidic rocks (six volcanic rocks, two pyroclastics and four granitic rocks) which were obtained from the western part of Aizu district. The district studied is one of the important acidic petrographic provinces in the Green tuff region of Northeast Japan, and is widely covered by the acidic volcanic rocks and pyroclastics of Neogene period. The ages of six volcanic rocks range from 8 to 23 m.y., and they are generally correlated to the stratigraphic units of the Neogene in Northeast Japan. Dating results on four granitic rocks from the Tagokura granitic body showed the age range of 39 to 65 m.y., corresponding to the Late Cretaceous to Eocene. A sample of dacitic welded tuff from the Miyako River area gave an age of 44 m.y. It is pointed out that the welded tuff may be correlated to the Late Cretaceous to Paleogene acidic igneous rocks such as Nohi rhyolites, Asahi rhyolites, Tagawa acidic rocks and others, on the basis of the age and lithofacies of the rock. However, further geological and geochronological data are necessary to settle the problem. (author)

  1. Nd and Sr isotopic variations in acidic rocks from Japan: significance of upper-mantle heterogeneity

    Science.gov (United States)

    Terakado, Yasutaka; Nakamura, Noboru

    1984-10-01

    Initial Nd and Sr isotopic ratios have been measured for Cretaceous acidic and related intermediate rocks (24 volcanic and two plutonic rocks) from the Inner Zone of Southwest Japan (IZSWJ) to investigate the genesis of acidic magmas. The initial Nd and Sr isotopic ratios for these rocks show three interesting features: (1) ɛ Nd values for acidic rocks (+2 to -9) are negatively correlated with ɛ Sr values (+10 to +90) together with those for intermediate rocks ( ɛ Nd=+3 to -8; ɛ Sr=0 to +65). (2) The ɛ Nd values for silica rich rocks (>60% SiO2) correlate with the longitude of the sample locality, decreasing from west to east in a stepwise fashion: Four areas characterized by uniform ɛ Nd values are discriminated. (3) Low silica rocks (Japan suggest that the acidic rocks can be formed neither by fractional crystallization processes from more basic magmas nor by crustal assimilation processes. The isotopic variations of the acidic rocks may reflect regional isotopic heterogeneity in the lower crust, and this heterogeneity may ultimately be attributed to the regional heterogeneity of the uppermost-mantle beneath the Japanese Islands.

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

    International Nuclear Information System (INIS)

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

    1995-01-01

    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

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

    DEFF Research Database (Denmark)

    Méndez-García, Celia; Mesa, Victoria; Sprenger, Richard Remko

    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...

  4. In situ studies with Asian clams (Carbacula fluminea) detect acid mine drainage and nutrient inputs in low-order streams

    International Nuclear Information System (INIS)

    Soucek, D. J.; Schmidt, T. S.; Cherry, D. S.

    2001-01-01

    This study evaluates the correlation between transplanted Asiatic clam and indigenous community responses to acid mine drainage and nutrient loading in first-to-third-order streams, by comparing the toxicological endpoints of clam survival and growth with benthic macro-invertebrate community indices as community responses to both acid mine drainage and nutrient loading. Clam survival was found to be positively correlated with water column pH and negatively correlated with conductivity and metal concentrations. There was also a positive correlation with the relative abundance of the macro-invertebrate Ephemeroptera, the most sensitive taxonomic group, to acid mine drainage in this watershed. No correlation was found between clam growth and acid mine drainage inputs, but there was evidence of positive correlation with nitrate concentrations and the relative abundance of collector-filterer functional feeding groups. These results suggest that clam growth is related to nutrient levels and accurately reflect benthic macro-invertebrate responses to nutrient loading. 28 refs., 5 tabs., 1 fig

  5. Preliminary Results: Release Of Metals From Acid-Mine Drainage Contaminated Streambed Sediments Under Anaerobic Conditions (Presentation)

    Science.gov (United States)

    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...

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

    NARCIS (Netherlands)

    Méndez-Garcia, C.; Mesa, V.; Sprenger, R.R.; Richter, M.; Suarez Diez, M.; Solano, J.; Bargiela, R.; Golyshina, O.V.; Manteca, A.; Ramos, J.L.; Gallego, J.R.; Llorente, I.; Martins Dos Santos, V.A.P.; Jensen, O.N.; Paláez, A.I.; Sánchez, J.; Ferrer, M.

    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

  7. Neutralization and attenuation of metal species in acid mine drainage and mine leachates using magnesite: a batch experimental approach

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2014-08-01

    Full Text Available International Mine Water Association Conference – An Interdisciplinary Response to Mine Water Challenges, China University of Mining and Technogy, China, China, 18-22 August 2014 Neutralization and Attenuation of Metal Species in Acid Mine Drainage and Mine...

  8. Acid mine drainage neutralization in a pilot sequencing batch reactor using limestone from a paper and pulp industry

    CSIR Research Space (South Africa)

    Vadapalli, VRK

    2015-10-01

    Full Text Available This study investigated the implications of using two grades of limestone from a paper and pulp industry for neutralization of acid mine drainage (AMD) in a pilot sequencing batch reactor (SBR). In this regard, two grades of calcium carbonate were...

  9. Mine drainage treatment

    OpenAIRE

    Golomeova, Mirjana; Zendelska, Afrodita; Krstev, Boris; Golomeov, Blagoj; Krstev, Aleksandar

    2012-01-01

    Water flowing from underground and surface mines and contains high concentrations of dissolved metals is called mine drainage. Mine drainage can be categorized into several basic types by their alkalinity or acidity. Sulfide rich and carbonate poor materials are expected to produce acidic drainage, and alkaline rich materials, even with significant sulfide concentrations, often produce net alkaline water. Mine drainages are dangerous because pollutants may decompose in the environment. In...

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

    International Nuclear Information System (INIS)

    Kim, A.G.

    1999-01-01

    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

  11. Influence of bouncing and assisted autogenic drainage on acid gastro-oesophageal reflux in infants.

    Science.gov (United States)

    Van Ginderdeuren, Filip; Vandenplas, Yvan; Deneyer, Michel; Vanlaethem, Sylvie; Buyl, Ronald; Kerckhofs, Eric

    2017-08-01

    To determine the influence of modern airway clearance techniques using assisted autogenic drainage (AAD), whether or not combined with bouncing, on acid gastro-oesophageal reflux (GOR) in infants reflux episodes (RE) and the refluxindex (RI) were the outcome measures. The results obtained during (T15) and 15 min after the intervention (T30) were compared to a period of 15 min before treatment (T0). The results of 150 infants, evenly distributed over the three treatment groups, were analyzed. No significant differences were found in number of RE at T15 and T30 compared to T0 in the bouncing group (P = 0.42), the AAD group (P = 0.14), and the BAAD group (P = 0.91). RI was significantly lower in the AAD group at T15 compared to T0 (P < 0.01). No differences in RI were found in the bouncing group (P = 0.28), nor in the BAAD group (P = 0.81). Bouncing, AAD and BAAD do not induce, nor aggravate acid GOR in infants under the age of 1 year. © 2017 Wiley Periodicals, Inc.

  12. Characterization of sulfur-oxidizing bacteria isolated from acid mine drainage and black shale samples

    International Nuclear Information System (INIS)

    Sajjad, W.; Bhatti, T. M.; Hasan, F.; Khan, S.; Badshah, M.

    2016-01-01

    Acid mine drainage (AMD) and black shale (BS) are the main habitats of sulfur-oxidizing bacteria. The aim of this study was to isolate and characterize sulfur-oxidizing bacteria from extreme acidic habitats (AMD and BS). Concentration of metals in samples from AMD and BS varied significantly from the reference samples and exceeded the acceptable limits set by the Environmental Protection Agency (EPA) and the World Health Organization (WHO). A total of 24 bacteria were isolated from these samples that were characterized both morphologically as well as through biochemical tests. All the bacteria were gram-negative rods that could efficiently oxidize sulfur into sulfate ions (SO/sub 4/-2), resulted into decrease in pH up to 1.0 when grown in thiosulfate medium with initial pH 4.0. Out of 24, only 06 isolates were selected for phylogenetic analysis through 16S rRNA sequencing, on the basis of maximum sulfur-oxidizing efficiency. The isolates were identified as the species from different genera such as Alcaligenes, Pseudomonas, Bordetella, and Stenotrophomonas on the basis of maximum similarity index. The concentration of sulfate ions produced was estimated in the range of 179-272 mg/L. These acidophiles might have various potential applications such as biological leaching of metals from low-grade ores, alkali soil reclamation and to minimize the use of chemical S-fertilizers and minimize environmental pollution. (author)

  13. [Experimental study on acid mine drainage treatment using mine tailings of Xiangsi Valley, Tongling, China].

    Science.gov (United States)

    Zhang, Nan; Chen, Tian-Hu; Zhou, Yue-Fei; Li, Shao-Jie; Jin, Jie; Wang, Yan-Ming

    2012-04-01

    Mine tailings in Xiangsi Valley, Tongling, China, is a typical skarn-type tailing with high contents of carbonates. This study designed dynamic leaching experiments to investigate the efficiency of this tailing under the acid mine drainage treatment. During 80 d trial period, the physical and chemical properties of influents were fixed and the effluents were monitored. After the trial, the speciation of Fe, Cu and Zn in solid was analyzed. The results showed that during the trial period, pH value maintained above 7.5. Moreover, the concentrations of Cu, Zn, Fe ions in effluents kept below 0.1, 0.4 and 1 mg x L(-1), respectively. In addition, the permeability coefficient of experimental column kept decreasing during the experimental period (from 0.23 cm x s(-1) to 0.10 cm x s(-1)). Five-step sequential extraction method was employed to study the distribution of elements at different depths. The results showed that Cu2+, Zn2+ were removed mainly through sorption and precipitation. This study indicates that Tongling skarn mine tailings have strong acid neutralization as well as heavy metal binding capacities. Therefore, the authors suggest that this mine tailing, which used to be waste, has a potential in AMD control and treatment.

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. In-stream chemical neutralization: A whole watershed approach to mitigating acid mine drainage

    International Nuclear Information System (INIS)

    Britt, D.L.

    1994-01-01

    The North Branch of the Potomac River is adversely affected by acid mine drainage (AMD) throughout its entire length. As an alternative to mine-mouth treatment methods an in-stream AMD-neutralization demonstration program for an approximately 25-mile segment of the North Branch of the Potomac River was designed and implemented. This river segment was ranked as the highest priority site in Maryland for a demonstration project owing to its combination of very poor water quality and excellent potential for supporting a recreational sport fishery in the absence of toxic metal and acid loadings. A whole-watershed approach employing Scandinavian doser technologies and calcium carbonate neutralizing agents is the basis for the North Branch Potomac River demonstration project. The project involves four phases: feasibility (1), design (2), implementation (3), and monitoring (4). This watershed approach to mitigating AMD is expected to restore circumneutrial water quality and to promote desirable fishery resources throughout the mainstem and selected tributaries of the North Branch of the Potomac River Upstream of Jennings Randolph Dam. This paper summarizes Phases 1--3 of the demonstration project

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

    Science.gov (United States)

    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

  17. The influence of biofilms on the migration of uranium in acid mine drainage (AMD) waters

    International Nuclear Information System (INIS)

    Krawczyk-Baersch, E.; Luensdorf, H.; Arnold, T.; Brendler, V.; Eisbein, E.; Jenk, U.; Zimmermann, U.

    2011-01-01

    The uranium mine in Koenigstein (Germany) is currently in the process of being flooded. Huge mass of Ferrovum myxofaciens dominated biofilms are growing in the acid mine drainage (AMD) water as macroscopic streamers and as stalactite-like snottites hanging from the ceiling of the galleries. Microsensor measurements were performed in the AMD water as well as in the biofilms from the drainage channel on-site and in the laboratory. The analytical data of the AMD water was used for the thermodynamic calculation of the predominance fields of the aquatic uranium sulfate (UO 2 SO 4 ) and UO 2 ++ speciation as well as of the solid uranium species Uranophane [Ca(UO 2 ) 2 (SiO 3 OH) 2 ·5H 2 O] and Coffinite [U(SiO 4 ) 1-x (OH) 4x ], which are defined in the stability field of pH > 4.8 and Eh 0 and Eh 4.8. Even analysis by Energy-filtered Transmission Electron Microscopy (EF-TEM) and electron energy loss spectroscopy (EELS) within the biofilms did not provide any microscopic or spectroscopic evidence for the presence of uranium immobilization. In laboratory experiments the first phase of the flooding process was simulated by increasing the pH of the AMD water. The results of the experiments indicated that the F. myxofaciens dominated biofilms may have a substantial impact on the migration of uranium. The AMD water remained acid although it was permanently neutralized with the consequence that the retention of uranium from the aqueous solution by the formation of solid uranium species will be inhibited. - Highlights: → Redox potential and pH of the biofilm differ significantly compared to the AMD water. → Formation of an aqueous uranium(VI) sulfate complex in the biofilm and in the AMD water. → Experiments revealed that the F. myxofaciens dominated biofilms have a substantial impact on the migration of uranium. → Due to homeostatic mechanisms the microbes maintain their intracellular pH even when the pH of the water increases.

  18. The influence of biofilms on the migration of uranium in acid mine drainage (AMD) waters

    Energy Technology Data Exchange (ETDEWEB)

    Krawczyk-Baersch, E., E-mail: E.Krawczyk-Baersch@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiochemistry, P.O. Box 51 01 19, D-01314 Dresden (Germany); Luensdorf, H. [Helmholtz Centre for Infection Research, Department of Vaccinology and Applied Microbiology, Inhoffenstr. 7, D-38124 Braunschweig (Germany); Arnold, T.; Brendler, V. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiochemistry, P.O. Box 51 01 19, D-01314 Dresden (Germany); Eisbein, E. [TU Bergakademie Freiberg, Institute of Physical Chemistry, Akademiestrasse 6, D-09596 Freiberg (Germany); Jenk, U.; Zimmermann, U. [Wismut GmbH, Jagdschaenkenstr. 29, D-09117 Chemnitz (Germany)

    2011-07-15

    The uranium mine in Koenigstein (Germany) is currently in the process of being flooded. Huge mass of Ferrovum myxofaciens dominated biofilms are growing in the acid mine drainage (AMD) water as macroscopic streamers and as stalactite-like snottites hanging from the ceiling of the galleries. Microsensor measurements were performed in the AMD water as well as in the biofilms from the drainage channel on-site and in the laboratory. The analytical data of the AMD water was used for the thermodynamic calculation of the predominance fields of the aquatic uranium sulfate (UO{sub 2}SO{sub 4}) and UO{sub 2}{sup ++} speciation as well as of the solid uranium species Uranophane [Ca(UO{sub 2}){sub 2}(SiO{sub 3}OH){sub 2}{center_dot}5H{sub 2}O] and Coffinite [U(SiO{sub 4}){sub 1-x}(OH){sub 4x}], which are defined in the stability field of pH > 4.8 and Eh < 960 mV and pH > 0 and Eh < 300 mV, respectively. The plotting of the measured redox potential and pH of the AMD water and the biofilm into the calculated pH-Eh diagram showed that an aqueous uranium(VI) sulfate complex exists under the ambient conditions. According to thermodynamic calculations a retention of uranium from the AMD water by forming solid uranium(VI) or uranium(IV) species will be inhibited until the pH will increase to > 4.8. Even analysis by Energy-filtered Transmission Electron Microscopy (EF-TEM) and electron energy loss spectroscopy (EELS) within the biofilms did not provide any microscopic or spectroscopic evidence for the presence of uranium immobilization. In laboratory experiments the first phase of the flooding process was simulated by increasing the pH of the AMD water. The results of the experiments indicated that the F. myxofaciens dominated biofilms may have a substantial impact on the migration of uranium. The AMD water remained acid although it was permanently neutralized with the consequence that the retention of uranium from the aqueous solution by the formation of solid uranium species will be

  19. A novel bioelectrochemical system for chemical-free permanent treatment of acid mine drainage.

    Science.gov (United States)

    Pozo, Guillermo; Pongy, Sebastien; Keller, Jürg; Ledezma, Pablo; Freguia, Stefano

    2017-12-01

    The mining sector is currently under unprecedented pressure due to stringent environmental regulations. As a consequence, a permanent acid mine drainage (AMD) treatment is increasingly being regarded as a desirable target with direct benefits for the environment and the operational and economic viability of the resources sector. In this study we demonstrate that a novel bioelectrochemical system (BES) can deliver permanent treatment of acid mine drainage without chemical dosing. The technology consists of a two-cell bioelectrochemical setup to enable the removal of sulfate from the ongoing reduction-oxidation sulfur cycle to less than 550 mg L -1 (85 ± 2% removal from a real AMD of an abandoned silver mine), thereby also reducing salinity at an electrical energy requirement of 10 ± 0.3 kWh kg -1 of SO 4 2- -S removed. In addition, the BES operation drove the removal and recovery of the main cations Al, Fe, Mg, Zn at rates of 151 ± 0 g Al m -3  d -1 , 179 ± 1 g Fe m -3  d -1 , 172 ± 1 g Mg m -3  d -1 and 46 ± 0 g Zn m -3  d -1 into a concentrate stream containing 263 ± 2 mg Al, 279 ± 2 mg Fe, 152 ± 0 mg Mg and 90 ± 0 mg Zn per gram of solid precipitated after BES fed-rate control treatment. The solid metal-sludge was twice less voluminous and 9 times more readily settleable than metal-sludge precipitated using NaOH. The continuous BES treatment also demonstrated the concomitant precipitation of rare earth elements together with yttrium (REY), with up to 498 ± 70 μg Y, 166 ± 27 μg Nd, 155 ± 14 μg Gd per gram of solid, among other high-value metals. The high-REY precipitates could be used to offset the treatment costs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Effects of acid mine drainage on a headwater stream ecosystem in Colorado

    International Nuclear Information System (INIS)

    Niyogi, D.K.; Lewis, W.M. Jr.; McKnight, D.M.

    1994-01-01

    The ecological effects of acid mine drainage were investigated during the summer of 1993 on St. Kevin Gulch, a headwater stream near Leadville, Colorado. The stream currently receives acidic water from an abandoned mine. The pH downstream of the mine is between 3.5 and 4.5, and several metals exceed concentrations toxic to aquatic organisms. Zinc is present at especially high concentrations (1 to 10 mg/L) Furthermore, the stream bottom is covered with a thick layer of iron hydroxide precipitates. Effects on stream biota have been dramatic. Aquatic flora in the affected reach is limited to a green filamentous alga, Ulothrix subtilissima. Macroinvertebrate densities are significantly lower in the affected reach (mean = 99 indiv/m 2 ; SD = 88 indiv/M 2 ) compared to an upstream (pristine) reference reach (mean = 1,735 indiv/m 2 ; SD = 652 indiv/M 2 ). Functional processes were also studied in the stream. Net primary production (NPP) was measured during midday with recirculating chambers. Production was significantly lower in the affected reach (mean NPP 13.3 MgO 2 hr -1 m -2 ; SD = 87 MgO 2 hr -1 m -2 ) than the upstream reference reach (NPP = 64.1 MgO 2 hr -1 m -2 ; SD = 27.7 MgO 2 hr -1 m -2 ). Decomposition, measured with litter bags, was also lower in the affected reach than the upstream site. In 1994, St. Kevin Gulch is scheduled to undergo remediation that will treat the acidic water from the mine. Further studies on this stream will provide information on the recovery processes in lotic ecosystems

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

  3. Role of rock texture and mineralogy on the hydrology and geochemistry of three neutral-drainage mesoscale experimental waste rock piles at the Antamina Mine, Peru

    Science.gov (United States)

    Peterson, H.; Bay, D. S.; Beckie, R. D.; Mayer, K. U.; Klein, B.; Smith, L.

    2009-12-01

    An ongoing study at the Antamina Cu-Zn-Mo mine in Peru investigates the hydrology and geochemistry of heterogeneous waste rock at multiple scales. Three of five instrumented mesoscale experimental waste rock piles (36m X 36m X 10m high) were constructed between 2006 and 2008. The coarsest-grained Pile 1 exhibits rapid, intense response to rain and returns to residual saturation relatively quickly, suggesting a significant influence of preferential flow in addition to high-conductivity matrix flow. Pile 2, the finest-grained of the three piles, exhibits signals from rain events that are significantly delayed and muted in comparison to those from Pile 1. Except for in the finest size fractions, the particle size distribution of Pile 3 closely resembles that of Pile 2, yet Pile 3 responds to rain events more similarly to Pile 1 than Pile 2. The presence of large boulders in Pile 3 could facilitate preferential flow, either through surface flow effects across boulders or by contributing to the formation of unfilled void space acting as macropores at high infiltration rates. The rapid rain event response of Pile 3 could also be attributed to a silt-clay percentage that is similar to Pile 1, which is less than half of the silt-clay percentage observed in Pile 2 (i.e., ~3%, ~8.5%, and ~4% for Piles 1, 2 and 3, respectively). For each of the three piles, the pH of effluent collected from bottom lysimeters and internal pore water sampled with suction lysimeters has remained circumneutral, with notable maximum concentrations of 2.8 mg/L Zn from Pile 1, which is comprised of slightly reactive hornfels and marble waste rock; 13.4 mg/L Zn and 22.7 mg/L Mo from Pile 2, comprised of reactive intrusive waste rock; and 42.5 mg/L Zn from Pile 3, comprised of reactive exoskarn waste rock. Ongoing work includes analysis of two additional mixed-rock experimental piles, studies to investigate the role of microbes on metal release (Dockrey et al., this session), analysis of pore gas

  4. Mechanism of removal and retention of heavy metals from the acid mine drainage to coastal wetland in the Patagonian marsh.

    Science.gov (United States)

    Idaszkin, Yanina L; Carol, Eleonora; María Del Pilar, Alvarez

    2017-09-01

    The attenuation of the acid mine drainage is one of the most important environmental challenges facing the mining industry worldwide. Mining waste deposits from an ancient metallurgical extraction of heavy metals were found near to the San Antonio marsh in Patagonia. The aim of this work was to determinate which mechanisms regulate the mobilization and retention of metals by acid drainage. A geological and geomorphological survey was carried out and samples from the mining waste deposits and the marsh were collected to determine soil texture, Eh pH, organic matter, Cu, Pb, Zn and Fe content, and soil mineralogical composition. Metals in marsh plants were determined in above- and below-ground structures. In the mining waste deposits polymetallic sulphides were recognized where the oxidation and formation of oxy-hydroxides and sulphates of Fe, Cu, Pb and Zn occurs. Then, by the alteration of those minerals, the metals enter in solution and are mobilized with the surface drainage towards the marsh where adsorption in the soils fine fraction and organic matter and/or by plants occurs. Locally, in the mining waste deposits, the precipitation/dissolution of Cu, Pb, and Zn sulphates take place in small centripetal drainage basins. In topographically lower portions of the marsh desorption and removal of metals by tidal flow could also be happen. The results allow to concluding that the marsh adjacent to the mining waste deposits is a geochemically active environment that naturally mitigates the contamination caused by acid drainage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Hydrochemical and isotopic study of groundwater impacted by the acid drainage of UrÂnio Mine - Osamu Utsumi, PoÇos de Caldas Plateau (MG), Brazil

    International Nuclear Information System (INIS)

    Alberti, Heber Luiz Caponi

    2017-01-01

    The Osamu Utsumi Mine - MOU, belonging to the Brazilian Nuclear Industries - INB, began in 1977 with pickling activities and remained in operation until 1995. During this period, 94 million tons of rocks were removed, which caused the generation of large wasted rock piles. The intense drainage and precipitation in the study region favored the oxidation and leaching of the wasted rock piles, causing the Acid Drainage of Mine - DAM and generating effluents with low pH and high concentrations of fluoride, aluminum, iron, manganese, sulfate, zinc, uranium and Radio, among others. Currently the MOU is in the process of decommissioning and environmental remediation. The understanding of the hydrogeochemical processes and the behavior of the water flow through different aquifers is extremely important so that the actions of environmental remediation and control of the DAM are really effective. In this sense, in this work, geoprocessing and hydrochemical techniques were used to propose a conceptual hydrogeochemical model in the MOU cavity system and wasted rock pile number 4 - BF4. The geoprocessing techniques allowed to characterize and size the area under study and to integrate information on geology and mineralogy with the hydrochemical data. The hydrochemical studies were based on three groundwater sampling campaigns, using the low flow method in 17 monitoring wells, as well as 3 water reservoirs in the study area. In the collected samples were determined: (1) the main cations and anions for groundwater classification using Piper and Stiff diagrams and multivariate statistical methods (cluster and Principal Component Analysis); (2) the major long half radionuclides and 222 Rn to assess radioactivity and imbalance between them; (3) the stable isotopes of 18 O and 2 H to provide information on the underground flows and water source; (4) the Tritium values found in the samples to estimate the age of the groundwater; (V) the sulfur and oxygen isotopes present in the

  6. Effects of remediation on the bacterial community of an acid mine drainage impacted stream.

    Science.gov (United States)

    Ghosh, Suchismita; Moitra, Moumita; Woolverton, Christopher J; Leff, Laura G

    2012-11-01

    Acid mine drainage (AMD) represents a global threat to water resources, and as such, remediation of AMD-impacted streams is a common practice. During this study, we examined bacterial community structure and environmental conditions in a low-order AMD-impacted stream before, during, and after remediation. Bacterial community structure was examined via polymerase chain reaction amplification of 16S rRNA genes followed by denaturing gradient gel electrophoresis. Also, bacterial abundance and physicochemical data (including metal concentrations) were collected and relationships to bacterial community structure were determined using BIO-ENV analysis. Remediation of the study stream altered environmental conditions, including pH and concentrations of some metals, and consequently, the bacterial community changed. However, remediation did not necessarily restore the stream to conditions found in the unimpacted reference stream; for example, bacterial abundances and concentrations of some elements, such as sulfur, magnesium, and manganese, were different in the remediated stream than in the reference stream. BIO-ENV analysis revealed that changes in pH and iron concentration, associated with remediation, primarily explained temporal alterations in bacterial community structure. Although the sites sampled in the remediated stream were in relatively close proximity to each other, spatial variation in community composition suggests that differences in local environmental conditions may have large impacts on the microbial assemblage.

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

    Energy Technology Data Exchange (ETDEWEB)

    Henry, T.B.; Irwin, E.R.; Grizzle, J.M.; Brumbaugh, W.G.; Wildhaber, M.L. [Auburn University, Auburn, AL (United States). Alabama Cooperative of Fish & Wildlife Research Unit

    2001-07-01

    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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  10. Seasonal factors controlling mineral precipitation in the acid mine drainage at Donghae coal mine, Korea

    International Nuclear Information System (INIS)

    Kim, J.J.; Kim, S.J.

    2004-01-01

    Monitoring over a 12 month period in the Sanae creek flow in acid mine drainage, Donghae coal mine area, demonstrates that the concentrations of dissolved metals and sulphate are highest during autumn when water flow in the creek is at its lowest. The highest pH values of the stream were measured in April and May, whereas the lowest pH was recorded in October. The Fe concentration of stream water rapidly decreased downstream due to the precipitation of Fe oxyhydroxide and/or oxyhydroxysulfate phases in the stream. Mineral precipitates in the creek in the Donghae mine area show various colours such as brownish yellow (Munsell colour 9.5 YR hues), reddish brown (Munsell colour 3.5 YR hues) and white depending on seasons and distance from the pollution source in the creek. Such phenomena are attributed to the variation in pH and chemical composition of stream water caused by seasonal factors. The measured pH ranges in stream water of the brownish yellow, white and reddish brown precipitates are pH 3.2-4.5, 4.5-6.0 and 5.3-6.9, respectively

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

    Science.gov (United States)

    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.

  12. Physiological and behavioral responses of stonefly nymphs to enhanced limestone treatment of acid mine drainage.

    Science.gov (United States)

    Cole, M B; Arnold, D E; Watten, B J

    2001-03-01

    A new acid mine drainage (AMD) treatment system uses pulsed, fluidized beds of limestone, and carbon dioxide pretreatment of influent AMD, to enhance limestone neutralization of AMD. We conducted laboratory studies to evaluate the behavior and physiology of larval stoneflies (Pteronarcys proteus, Plecoptera) exposed to effluents produced by the treatment system. Survival, sodium balance, drift, and feeding responses by P. proteus to treated and untreated AMD were examined. P. proteus nymphs exhibited significant losses of whole body sodium in exposures to untreated AMD. Nymphs exposed to treated effluents experienced no loss of whole-body sodium. Nymphs exposed to untreated AMD showed elevated drift rates and depressed feeding rates relative to those of nymphs exposed to treated AMD, and to AMD-free controls. No significant differences in feeding or drift behavior occurred between nymphs exposed to treated effluents and those exposed to AMD-free controls. The treatment system, with and without CO2 pretreatment, provided water that was not toxic to the test animals, and that allowed normal behavioral and physiological function.

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

    Science.gov (United States)

    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 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

  14. Cytotoxic and genotoxic affects of acid mine drainage on fish Channa punctata (Bloch).

    Science.gov (United States)

    Talukdar, B; Kalita, H K; Basumatary, S; Saikia, D J; Sarma, D

    2017-10-01

    The investigation deals with the effects of Acid Mine Drainage (AMD) of coal mine on fish Channa punctata (Bloch) by examining the incidence of haematological, morphological, histological changes and DNA fragmentation in tissues of C. punctata in laboratory condition. For this study fishes were exposed to 10% of AMD for a period of 30 days. The fusion of the primary and secondary gill lamellae, distortion, loss of alignment, deposition of worn out tissues and mucous on the surface of the lamella in the gills; degeneration of morphological architecture, loss of alignment of tubules, mucous deposition in the kidney; cellular damage, cellular necrosis, extraneous deposition on the surface, pore formation in the liver are some important changes detected by scanning electron microscopy. Fishes of AMD treated group showed gradual significant decrease in TEC, Hb and, increase in TLC and DLC as compared to that of the control. DNA fragmentation observed in kidney of fishes from treated group indicates an intricate pollutant present in the AMD. The high incidence of morphological and histological alterations, haematological changes along with DNA breakage in C. punctata is an evidence of the cytotoxic and genotoxic potential of AMD of coal mines. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Microbial community analysis in rice paddy soils irrigated by acid mine drainage contaminated water.

    Science.gov (United States)

    Sun, Min; Xiao, Tangfu; Ning, Zengping; Xiao, Enzong; Sun, Weimin

    2015-03-01

    Five rice paddy soils located in southwest China were selected for geochemical and microbial community analysis. These rice fields were irrigated with river water which was contaminated by Fe-S-rich acid mine drainage. Microbial communities were characterized by high-throughput sequencing, which showed 39 different phyla/groups in these samples. Among these phyla/groups, Proteobacteria was the most abundant phylum in all samples. Chloroflexi, Acidobacteria, Nitrospirae, and Bacteroidetes exhibited higher relative abundances than other phyla. A number of rare and candidate phyla were also detected. Moreover, canonical correspondence analysis suggested that pH, sulfate, and nitrate were significant factors that shaped the microbial community structure. In addition, a wide diversity of Fe- and S-related bacteria, such as GOUTA19, Shewanella, Geobacter, Desulfobacca, Thiobacillus, Desulfobacterium, and Anaeromyxobacter, might be responsible for biogeochemical Fe and S cycles in the tested rice paddy soils. Among the dominant genera, GOUTA19 and Shewanella were seldom detected in rice paddy soils.

  16. Identification of nitrogen-fixing genes and gene clusters from metagenomic library of acid mine drainage.

    Science.gov (United States)

    Dai, Zhimin; Guo, Xue; 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.

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

    Science.gov (United States)

    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 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.

  18. Investigating the formation of acid mine drainage of Toledo pyrite concentrate using column cells

    Science.gov (United States)

    Aguila, Diosa Marie

    2018-01-01

    Acid mine drainage (AMD) is an inevitable problem in mining and has adverse effects in water quality. Studying AMD formation will be valuable in controlling the composition of mine waters and in planning the rehabilitation method for a mine. In this research, kinetics of AMD formation of Toledo pyrite was studied using two column experiments. The mechanisms of AMD formation and the effects of various factors on pH drop were first studied. Another column test was done for validation and to study the role of Fe2+/Fe3+ ratio in the change of leachate pH. The first experiment revealed that time and particle size are the most significant factors. It was also observed that the sudden pH drop during the starting hours was due to cracks formed from beneficiation, and the formation of Fe(OH)3. The laddered behavior of pH thereafter was due to decrease in formation of Fe(OH)3, and the precipitates in pyrite surface that lowered the surface area available for pyrite oxidation. The results of the second experiment validated the laddered behavior of pH. It was also observed that particle size distribution and pyrite surface were affected by the change in pH. Fe2+/Fe3+ ratio of leachate generally decreased as pH dropped.

  19. Two-stage combined treatment of acid mine drainage and municipal wastewater.

    Science.gov (United States)

    Deng, Dongyang; Lin, Lian-Shin

    2013-01-01

    This study examined the feasibility of the combined treatment of field-collected acid mine drainages (AMD, pH = 4.2 ± 0.9, iron = 112 ± 118 mg/L, sulfate = 1,846 ± 594 mg/L) and municipal wastewater (MWW, avg. chemical oxygen demand (COD) = 234-333 mg/L) using a two-stage process. The process consisted of batch mixing of the two wastes to condition the mixture solutions, followed by anaerobic biological treatment. The mixings performed under a range of AMD/MWW ratios resulted in phosphate removal of 9 to ∼100%, the mixture pH of 6.2-7.9, and COD/sulfate concentration ratio of 0.05-5.4. The biological treatment consistently removed COD and sulfate by >80% from the mixture solutions for COD/sulfate ratios of 0.6-5.4. Alkalinity was produced in the biological treatment causing increased pH and further removal of metals from the solutions. Scanning electron microscopy of produced sludge with energy dispersion analysis suggested chemical precipitation and associated adsorption and co-precipitation as the mechanisms for metal removal (Fe: >99%, Al: ∼100%, Mn: 75 to ∼100%, Ca: 52-81%, Mg: 13-76%, and Na: 56-76%). The study showed promising results for the treatment method and denoted the potential of developing innovative technologies for combined management of the two wastes in mining regions.

  20. Silane-based coatings on the pyrite for remediation of acid mine drainage.

    Science.gov (United States)

    Diao, Zenghui; Shi, Taihong; Wang, Shizhong; Huang, Xiongfei; Zhang, Tao; Tang, Yetao; Zhang, Xiaying; Qiu, Rongliang

    2013-09-01

    Acid mine drainage (AMD) resulting from the oxidation of pyrite and other metal sulfides has caused significant environmental problems, including acidification of rivers and streams as well as leaching of toxic metals. With the goal of controlling AMD at the source, we evaluated the potential of tetraethylorthosilicate (TEOS) and n-propyltrimethoxysilane (NPS) coatings to suppress pyrite oxidation. The release of total Fe and SO4(-2) from uncoated and coated pyrite in the presence of a chemical oxidizing agent (H2O2) or iron-oxidizing bacteria (Acidithiobacillus ferrooxidans) was measured. Results showed that TEOS- and NPS-based coatings reduced chemical oxidation of pyrite by as much as 59 and 96% (based on Fe release), respectively, while biological oxidation of pyrite was reduced by 69 and 95%, respectively. These results were attributed to the formation of a dense network of Fe-O-Si and Si-O-Si bonds on the pyrite surface that limited permeation of oxygen, water, and bacteria. Compared with results for TEOS-coated pyrite, higher pH and lower concentrations of total Fe and SO4(-2) were observed for oxidation of NPS-coated pyrite, which was attributed to its crack-free morphology and the presence of hydrophobic groups on the NPS-based coating surface. The silane-based NPS coating was shown to be highly effective in suppressing pyrite oxidation, making it a promising alternative for remediation of AMD at its source. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  2. Identification of nitrogen-fixing genes and gene clusters from metagenomic library of acid mine drainage.

    Directory of Open Access Journals (Sweden)

    Zhimin Dai

    Full Text Available 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.

  3. Ball-milling effect on Indonesian natural bentonite for manganese removal from acid mine drainage

    Directory of Open Access Journals (Sweden)

    Prastistho Widyawanto

    2018-01-01

    Full Text Available The influences of mechanical milling on Indonesian Natural Bentonite (INB characteristics and manganese (Mn removal from acid mine drainage (AMD were investigated. The INB characteristics were observed by scanning electron microscope (SEM, X-ray diffraction (XRD, nitrogen adsorption-desorption for specific surface area (SSA and microporosity measurement, cation exchange capacity (CEC and particle size distribution (PSD analyzer. Four minutes milling with frequency 20 Hz on INB caused morphological change which showed more crumbled and destructed particle, lost the (001 peak but still retained the (100 peak that indicated delamination of montmorillonite mineral without breaking the tetrahedral-octahedral-tetrahedral (T-O-T structure, rose the CEC from 28.49 meq/100g to 35.51 meq/100g, increase in the SSA from 60.63 m2/g to 104.88 m2/g, significant increase in microporosity which described in the t plots and decrease in the mean particle size distribution peak from 49.28 μm to 38.84 μm. The effect of contact time and effect of adsorbent dosage on Mn sorption was studied. Both unmilled and milled samples reached equilibrium at 24 hours and the pH rose from 4 to 7 in first 30 minutes. The Mn removal percentage increased significantly after milling. Using Langmuir isotherm, the maximum adsorbed metals (qmax also increased from 0.570 to 4.219 mg/g.

  4. Oxidative Precipitation of Manganese from Acid Mine Drainage by Potassium Permanganate

    Directory of Open Access Journals (Sweden)

    Regeane M. Freitas

    2013-01-01

    Full Text Available Although oxidative precipitation by potassium permanganate is a widely recognised process for manganese removal, research dealing with highly contaminated acid mine drainage (AMD has yet to be performed. The present study investigated the efficiency of KMnO4 in removing manganese from AMD effluents. Samples of AMD that originated from inactive uranium mine in Brazil were chemically characterised and treated by KMnO4 at pH 3.0, 5.0, and 7.0. Analyses by Raman spectroscopy and geochemical modelling using PHREEQC code were employed to assess solid phases. Results indicated that the manganese was rapidly oxidised by KMnO4 in a process enhanced at higher pH. The greatest removal, that is, 99%, occurred at pH 7.0, when treated waters presented manganese levels as low as 1.0 mg/L, the limit established by the Brazilian legislation. Birnessite (MnO2, hausmannite (Mn3O4, and manganite (MnOOH were detected by Raman spectroscopy. These phases were consistently identified by the geochemical model, which also predicted phases containing iron, uranium, manganese, and aluminium during the correction of the pH as well as bixbyite (Mn2O3, nsutite (MnO2, pyrolusite (MnO2, and fluorite (CaF2 following the KMnO4 addition.

  5. The Regulation of Acid Mine Drainage in South Africa: Law and Governance Perspectives

    Directory of Open Access Journals (Sweden)

    Loretta Feris

    2014-12-01

    Full Text Available Acid mine drainage (AMD is arguably one of the most serious environmental concerns in South Africa. AMD is a legacy left behind by abandoned, derelict and defunct mines, and is a continuing by-product of existing mining activities. In addition to its environmental impacts, AMD will also impact on all the parameters of sustainability, including ecological, social and economic concerns. In particular, AMD is set to affect infrastructure, displace people and affect their livelihoods, influence economic activity, impact on the resource extraction industry, and affect South Africa's policies and actions in relation to climate change and its efforts to move towards a low carbon economy; and it will test the efficiency of regulatory interventions emanating from both the private and the public sector to the extreme. Given these pervasive challenges, in this article we provide a survey of the AMD problem in South Africa through the law and governance lens. We commence by highlighting the various issues and challenges that result from AMD in the environmental context on the one hand, and the law and governance context on the other hand. We then describe the many provisions of the regulatory framework that we believe would be instrumental in responding to the threat. We conclude the article with brief remarks on what we believe are important considerations in the future regulation of AMD.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Injection of alkaline ashes into underground coal mines for acid mine drainage abatement

    International Nuclear Information System (INIS)

    Aljoe, W.W.

    1996-01-01

    The injection of alkaline coal combustion waste products into abandoned underground coal mines for acid mine drainage (AMD) abatement has obvious conceptual appeal. This paper summarizes the findings of the baseline hydrogeologic and water quality evaluations at two sites--one in West Virginia and one in Maryland--where field demonstrations of the technique are being pursued in cooperative efforts among State and Federal agencies and/or private companies. The West Virginia site produces severe AMD from three to seven AMD sources that are spaced over about a 1.2 km stretch of the down-dip side of the mine workings. By completely filling the most problematic portion of the mine workings with coal combustion ashes, the State expects that the costs and problems associated with AMD treatment will be greatly reduced. At the Maryland site, it is expected that the AMD from a relatively small target mine will be eliminated completely by filling the entire mine void with a grout composed of a mixture of fly ash, fluidized-bed combustion ash, and flue gas desulfurization sludge. This project will also demonstrate the potential cost-effectiveness of the technique at other sites, both for the purpose of AMD remediation and control of land subsidence

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

    Directory of Open Access Journals (Sweden)

    Annika C. Mosier

    2016-03-01

    Full Text Available 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 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.

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

    Science.gov (United States)

    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

  11. Treatment of acid drainage in uranium deposit by means of a natural wetland

    International Nuclear Information System (INIS)

    Grudeva, V.I.; Stoyanova, A.D.; Grudev, S.N.

    2004-01-01

    Acid drainage waters generated in the uranium deposit G-1, Western Bulgaria, were treated by means of a natural wetland located in the deposit. The waters had a pH in the range of about 2.4-3.9 and contained uranium and radium radionuclides, heavy metals (copper, zinc , cadmium, iron, manganese) arsenic and sulfates in concentrations usually much higher than the relevant permissible levels for waters intended for use in agriculture and/or industry. The wetland was characterized by abundant and emergent vegetation and a diverse microflora. Typha latifolia, Typha augustifolia and Potamogeton australis were the main plant species in the wetland but representatives of the genera Scirpus, Juncus, Elepchoris, Potamogeton, Carex and Poa as well as different algae were also present. The water flows through the wetland varied in the range at about 0.2-1,2 l/s reflecting water residence times in the wetland of about 10-50 hours. An efficient water cleanup took place in the wetland even during the cold winter months at ambient temperatures close to 0 o C. The removal of pollutants was due to different processes but the microbial dissimilatory sulphate reduction and the sorption of pollutants on organic matter (living and dead plant and microbial biomass) and clays present in the wetland played the main role. (author)

  12. Magnetite and cobalt ferrite nanoparticles used as seeds for acid mine drainage treatment

    Energy Technology Data Exchange (ETDEWEB)

    Kefeni, Kebede K., E-mail: kkefeni@gmail.com; Mamba, Bhekie B.; Msagati, Titus A.M.

    2017-07-05

    Highlights: • Presence of α-Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} in AMD resulted in formation of crystalline ferrite. • Increasing settling time improved removal of Mg, Ca, Mn and Na from AMD. • Mixtures of ferrite nanoparticles were produced from AMD. • Formations of crystalline ferrite were more favored in the presence of heat. - Abstract: In this study, magnetite and cobalt ferrite nanoparticles were used as seeds for acid mine drainage (AMD) treatment at pH of 7.05 ± 0.35. Duplicate samples of AMD, one without heating and another with heating at 60 °C was treated under continuous stirring for 1 h. The filtrate analysis results from ICP-OES have shown complete removal of Al, Mg, and Mn, while for Fe, Ni and Zn over 90% removals were recorded. Particularly, settling time has significant effect on the removal of Mg, Ca and Na. The results from SQUID have shown superparamagnetic properties of the synthesised magnetic nanoparticles and ferrite sludge. The recovered nanoparticles from AMD are economically important and reduce the cost of waste disposal.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-01-01

    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 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.

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

    Science.gov (United States)

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

    2012-01-03

    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.

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

    Science.gov (United States)

    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.

  17. Study of acid mine drainage management with evaluating climate and rainfall in East Pit 3 West Banko coal mine

    Science.gov (United States)

    Rochyani, Neny

    2017-11-01

    Acid mine drainage is a major problem for the mining environment. The main factor that formed acid mine drainage is the volume of rainfall. Therefore, it is important to know clearly the main climate pattern of rainfall and season on the management of acid mine drainage. This study focuses on the effects of rainfall on acid mine water management. Based on daily rainfall data, monthly and seasonal patterns by using Gumbel approach is known the amount of rainfall that occurred in East Pit 3 West Banko area. The data also obtained the highest maximum daily rainfall on 165 mm/day and the lowest at 76.4 mm/day, where it is known that the rainfall conditions during the period 2007 - 2016 is from November to April so the use of lime is also slightly, While the low rainfall is from May to October and the use of lime will be more and more. Based on calculation of lime requirement for each return period, it can be seen the total of lime and financial requirement for treatment of each return period.

  18. The Application of Sulphate-Reducing Bacteria for the Heavy Metals Elimination from Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Alena Luptáková

    2004-12-01

    Full Text Available One of the most important problems affecting mining companies around the world is the treatment of acid mine drainage (AMD. AMD is characterised by its high acidity, high concentration of metals (Cu, Zn, Cd,… and high concentration of dissolved sulphates. The techniques traditionally used for the treatment of AMD have been based on chemical methods of neutralization and precipitation. A possible alternative to the chemical treatment of AMD is bioremediation using anaerobic sulphate-reducing bacteria (SRB. The treatment of AMD by SRB is based on the ability of SRB to reduce sulphates to hydrogen sulphide, which binds readily with metals to form sparingly soluble precipitates. In this study we have attempted to investigate the feasibility of anaerobic biotreatment of the copper contaminated model solution and a real effluent AMD from the shaft Pech (the locality Smolnik using SRB. This method involves three stages: The H2S production by sulphate-reducing bacteria, the metals precipitation by the biologically produced H2S and the metal sulphides filtration. The studies confirm that copper was effectively recovered from the solution using bacterial produced H2S. An initial copper concentration 10 mg.l-1 was decreased to less than 0.05 mg.l-1 after 3 hours. The most adequate pH value for cooper precipitation was 2.5. Results of the copper precipitation from the areal effluent indicates that the optimal pH value for the copper precipitation is 3.5, but the created precipitates contain a mixture of copper and iron sulphides.

  19. Bacterial, Archaeal, and Eukaryotic Diversity across Distinct Microhabitats in an Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Victoria Mesa

    2017-09-01

    Full Text Available Acid mine drainages are characterized by their low pH and the presence of dissolved toxic metallic species. Microorganisms survive in different microhabitats within the ecosystem, namely water, sediments, and biofilms. In this report, we surveyed the microbial diversity within all domains of life in the different microhabitats at Los Rueldos abandoned mercury underground mine (NW Spain, and predicted bacterial function based on community composition. Sediment samples contained higher proportions of soil bacteria (AD3, Acidobacteria, as well as Crenarchaeota and Methanomassiliicoccaceae archaea. Oxic and hypoxic biofilm samples were enriched in bacterial iron oxidizers from the genus Leptospirillum, order Acidithiobacillales, class Betaproteobacteria, and archaea from the class Thermoplasmata. Water samples were enriched in Cyanobacteria and Thermoplasmata archaea at a 3–98% of the sunlight influence, whilst Betaproteobacteria, Thermoplasmata archaea, and Micrarchaea dominated in acid water collected in total darkness. Stalactites hanging from the Fe-rich mine ceiling were dominated by the neutrophilic iron oxidizer Gallionella and other lineages that were absent in the rest of the microhabitats (e.g., Chlorobi, Chloroflexi. Eukaryotes were detected in biofilms and open-air water samples, and belonged mainly to clades SAR (Alveolata and Stramenopiles, and Opisthokonta (Fungi. Oxic and hypoxic biofilms displayed higher proportions of ciliates (Gonostomum, Oxytricha, whereas water samples were enriched in fungi (Paramicrosporidium and unknown microbial Helotiales. Predicted function through bacterial community composition suggested adaptive evolutive convergence of function in heterogeneous communities. Our study showcases a broad description of the microbial diversity across different microhabitats in the same environment and expands the knowledge on the diversity of microbial eukaryotes in AMD habitats.

  20. Bacterial, Archaeal, and Eukaryotic Diversity across Distinct Microhabitats in an Acid Mine Drainage

    Science.gov (United States)

    Mesa, Victoria; Gallego, Jose L. R.; González-Gil, Ricardo; Lauga, Béatrice; Sánchez, Jesús; Méndez-García, Celia; Peláez, Ana I.

    2017-01-01

    Acid mine drainages are characterized by their low pH and the presence of dissolved toxic metallic species. Microorganisms survive in different microhabitats within the ecosystem, namely water, sediments, and biofilms. In this report, we surveyed the microbial diversity within all domains of life in the different microhabitats at Los Rueldos abandoned mercury underground mine (NW Spain), and predicted bacterial function based on community composition. Sediment samples contained higher proportions of soil bacteria (AD3, Acidobacteria), as well as Crenarchaeota and Methanomassiliicoccaceae archaea. Oxic and hypoxic biofilm samples were enriched in bacterial iron oxidizers from the genus Leptospirillum, order Acidithiobacillales, class Betaproteobacteria, and archaea from the class Thermoplasmata. Water samples were enriched in Cyanobacteria and Thermoplasmata archaea at a 3–98% of the sunlight influence, whilst Betaproteobacteria, Thermoplasmata archaea, and Micrarchaea dominated in acid water collected in total darkness. Stalactites hanging from the Fe-rich mine ceiling were dominated by the neutrophilic iron oxidizer Gallionella and other lineages that were absent in the rest of the microhabitats (e.g., Chlorobi, Chloroflexi). Eukaryotes were detected in biofilms and open-air water samples, and belonged mainly to clades SAR (Alveolata and Stramenopiles), and Opisthokonta (Fungi). Oxic and hypoxic biofilms displayed higher proportions of ciliates (Gonostomum, Oxytricha), whereas water samples were enriched in fungi (Paramicrosporidium and unknown microbial Helotiales). Predicted function through bacterial community composition suggested adaptive evolutive convergence of function in heterogeneous communities. Our study showcases a broad description of the microbial diversity across different microhabitats in the same environment and expands the knowledge on the diversity of microbial eukaryotes in AMD habitats. PMID:28955322

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

    Science.gov (United States)

    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

  2. Sulfidogenic biotreatment of synthetic acid mine drainage and sulfide oxidation in anaerobic baffled reactor

    Energy Technology Data Exchange (ETDEWEB)

    Bekmezci, Ozan K.; Ucar, Deniz [Harran University, Environmental Engineering Department, Osmanbey Campus, 63000 Sanliurfa (Turkey); Kaksonen, Anna H. [CSIRO Land and Water, Underwood Avenue, Floreat, WA 6014 (Australia); Sahinkaya, Erkan, E-mail: erkansahinkaya@yahoo.com [Harran University, Environmental Engineering Department, Osmanbey Campus, 63000 Sanliurfa (Turkey)

    2011-05-30

    The treatment of synthetic acid mine drainage (AMD) water (pH 3.0-6.5) containing sulfate (3.0-3.5 g L{sup -1}) and various metals (Co, Cu, Fe, Mn, Ni, and Zn) was studied in an ethanol-fed sulfate-reducing 4-compartment anaerobic baffled reactor (ABR) at 32 {sup o}C. The reactor was operated for 160 days at different chemical oxygen demand (COD)/sulfate ratios, hydraulic retention times (HRT), pH, and metal concentrations to study the robustness of the process. The last compartment of the reactor was aerated at different rates to study the bio-oxidation of sulfide to elemental sulfur. The highest sulfate reduction efficiency (88%) was obtained with a feed sulfate concentration of 3.5 g L{sup -1}, COD/sulfate mass ratio of 0.737, feed pH of 3.0 and HRT of 2 days without aeration in the 4th compartment. The corresponding COD removal efficiency was about 92%. The alkalinity produced in the sulfidogenic ethanol oxidation neutralized the acidic mine water from pH 3.0-4.5 to pH 7.0-8.0. Effluent soluble and total heavy metal concentrations were substantially reduced with removal efficiencies generally higher than 99%, except for Mn (25-77%). Limited aeration in the 4th compartment of ABR promoted incomplete oxidation of sulfide to elemental sulfur rather than complete oxidation to sulfate. Depending on the aeration rate and HRT, 32-74% of produced sulfide was oxidized to elemental sulfur. This study demonstrates that by optimizing operating conditions, sulfate reduction, metal removal, alkalinity generation, and excess sulfide oxidation can be achieved in a single ABR treating AMD.

  3. Geochemical behavior of metals and metalloids in an estuary affected by acid mine drainage (AMD).

    Science.gov (United States)

    Hierro, A; Olías, M; Ketterer, M E; Vaca, F; Borrego, J; Cánovas, C R; Bolivar, J P

    2014-02-01

    The Tinto and Odiel rivers in southwest Spain drain the world's largest sulfide mineral formation: the Iberian Pyrite Belt which has been worked since 2,500 BC. The Tinto and Odiel estuarine zones include both an extensive area of salt marsh and an intensively industrialized urban area. As a consequence of pyrite oxidation, the Tinto and Odiel rivers are strongly acidic (pH major and trace elements were determined in the acid mine drainage affected estuary of the Ría de Huelva. During estuarine mixing, ore-derived metal concentrations exhibit excellent correlations with pH as the main controlling parameter. As pH increases, concentrations of dissolved ore-associated elements are attenuated, and this process is enhanced during the summer months. The decrease in Fe and Al concentrations ranged from 80 to 100 % as these elements are converted from dissolved to sediment-associated forms in the estuary. Coprecipitation/adsorption processes also removed between 60 and 90 % of the originally dissolved Co, Cu, Mn, Pb, Zn, and Th; however, Cd and Ni exhibited a greater propensity to remain in solution, with an average removal of approximately 60 %. On the other hand, As and U exhibited a different behavior; it is likely that these elements remain in dissolved forms because of the formation of U carbonates and soluble As species. Concentrations of As remain at elevated levels in the outer estuary (average = 48 μg L(-1)) which exceeds concentrations present in the Tinto River. Nevertheless, the estuary has recently witnessed improvements in water quality, as compared to results of several previous studies reported in the 1990s.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

    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

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

    Science.gov (United States)

    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.

  6. Acid neutralizing capacity and leachate results for igneous rocks, with associated carbon contents of derived soils, Animas River AML site, Silverton, Colorado

    Science.gov (United States)

    Yager, Douglas B.; Stanton, Mark R.; Choate, LaDonna M.; Burchell,

    2009-01-01

    Mine planning efforts have historically overlooked the possible acid neutralizing capacity (ANC) that local igneous rocks can provide to help neutralize acidmine drainage. As a result, limestone has been traditionally hauled to mine sites for use in neutralizing acid drainage. Local igneous rocks, when used as part of mine life-cycle planning and acid mitigation strategy, may reduce the need to transport limestone to mine sites because these rocks can contain acid neutralizing minerals. Igneous hydrothermal events often introduce moderately altered mineral assemblages peripheral to more intensely altered rocks that host metal-bearing veins and ore bodies. These less altered rocks can contain ANC minerals (calcite-chlorite-epidote) and are referred to as a propylitic assemblage. In addition, the carbon contents of soils in areas of new mining or those areas undergoing restoration have been historically unknown. Soil organic carbon is an important constituent to characterize as a soil recovery benchmark that can be referred to during mine cycle planning and restoration. This study addresses the mineralogy, ANC, and leachate chemistry of propylitic volcanic rocks that host polymetallic mineralization in the Animas River watershed near the historical Silverton, Colorado, mining area. Acid titration tests on volcanic rocks containing calcite (2 – 20 wt %) and chlorite (6 – 25 wt %), have ANC ranging from 4 – 146 kg/ton CaCO3 equivalence. Results from a 6-month duration, kinetic reaction vessel test containing layered pyritic mine waste and underlying ANC volcanic rock (saturated with deionized water) indicate that acid generating mine waste (pH 2.4) has not overwhelmed the ANC of propylitic volcanic rocks (pH 5.8). Sequential leachate laboratory experiments evaluated the concentration of metals liberated during leaching. Leachate concentrations of Cu-Zn-As-Pb for ANC volcanic rock are one-to-three orders of magnitude lower when compared to leached solution from

  7. Environmental Decision Making on Acid Mine Drainage Issues in South Africa: An Argument for the Precautionary Principle.

    Science.gov (United States)

    Morodi, T J; Mpofu, Charles

    2017-06-28

    This paper examines the issue of acid mine drainage in South Africa and environmental decision making processes that could be taken to mitigate the problem in the context of both conventional risk assessment and the precautionary principle. It is argued that conventional risk assessment protects the status quo and hence cannot be entirely relied upon as an effective tool to resolve environmental problems in the context of South Africa, a developing country with complex environmental health concerns. The complexity of the environmental issues is discussed from historical and political perspectives. An argument is subsequently made that the precautionary principle is an alternative tool, and its adoption can be used to empower local communities. This work, therefore, adds to new knowledge by problematising conventional risk assessment and proposing the framing of the acid mine drainage issues in a complex and contextual scenario of a developing country-South Africa.

  8. Using AVIRIS In The NASA BAA Project To Evaluate The Impact Of Natural Acid Drainage On Colorado Watersheds

    Science.gov (United States)

    Hauff, Phoebe L.; Coulter, David W.; Peters, Douglas C.; Sares, Matthew A.; Prosh, Eric C.; Henderson, Frederick B., III; Bird, David

    2004-01-01

    The Colorado Geological Survey and the co-authors of this paper were awarded one of 15 NASA Broad Agency Announcement (BAA) grants in 2001. The project focuses on the use of hyperspectral remote sensing to map acid-generating minerals that affect water quality within a watershed, and to identify the relative contributions of natural and anthropogenic sources to that drainage. A further objective is to define the most cost-effective remote sensing instrument configuration for this application.

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

    Science.gov (United States)

    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.

  10. Preliminary results of ecotoxicological assessment of an Acid Mine Drainage (AMD) passive treatment system testing water quality of depurated lixiviates

    OpenAIRE

    Miguel Sarmiento, Aguasanta; Bonnail, Estefanía; Nieto Liñán, José Miguel; Valls Casillas, Tomás Ángel del

    2017-01-01

    The current work reports on the preliminary results of a toxicity test using screening experiments to check the efficiency of an innovative passive treatment plant designed for acid mine drainage purification. Bioassays took place with water samples before and after the treatment system and in the river, once treated water is discharged. Due to the high toxicity of the water collected at the mouth of the mine (before the treatment plant), the bioassay was designed and developed with respect t...

  11. Geochemistry and microbial community composition across a range of acid mine drainage impact and implications for the Neoarchean-Paleoproterozoic transition

    Science.gov (United States)

    Havig, Jeff R.; Grettenberger, Christen; Hamilton, Trinity L.

    2017-06-01

    Streams impacted by acid mine drainage (AMD, also known as acid rock drainage) represent local environmental and ecological disasters; however, they may also present an opportunity to study microbial communities in environments analogous to past conditions. Neoarchean continents had streams and rivers replete with detrital pyrites. Following the emergence of oxygenic photosynthesis, Cyanobacteria colonized streams and rivers on continental surfaces. The combination of labile detrital pyrite grains and locally produced O2 generated by Cyanobacteria produced ideal conditions for pyrite oxidation similar to that found at modern AMD-impacted sites. To explore the connection of modern sites to ancient conditions, we sampled sites that exhibited a range of AMD-impact (e.g., pH from 2.1 to 7.9 [Fe2+] up to 5.2 mmol/L [SO42-] from 0.3 to 52.4 mmol/L) and found (i) nearly all analytes correlated to sulfate concentration; (ii) all sites exhibited the predominance of a single taxon most closely related to Ferrovum myxofaciens, an Fe-oxidixing betaproteoabacterium capable of carbon and nitrogen fixation, and (iii) signs of potential inorganic carbon limitation and nitrogen cycling. From these findings and building on the work of others, we present a conceptual model of continental surfaces during the Neoarchean and Paleoproterozoic linking local O2 production to pyrite oxidation on continental surfaces to sulfate production and delivery to nearshore environments. The delivery of sulfate drives sulfate reduction and euxinia—favoring anoxygenic photosynthesis over cyanobacterial O2 generation in near-continent/shelf marine environments.

  12. Uranium pollution in an estuary affected by pyrite acid mine drainage and releases of naturally occurring radioactive materials

    International Nuclear Information System (INIS)

    Villa, M.; Manjon, G.; Hurtado, S.; Garcia-Tenorio, R.

    2011-01-01

    Highlights: → Huelva estuary is affected by former phosphogypsum releases and pyrite acid mine drainage. → Time evolution of uranium concentration is analyzed after halting of NORM releases. → Two new contamination sources are preventing the complete uranium cleaning: (1) The leaching of phosphogypsum stacks located close to Tinto River. (2) Pyrite acid mine drainage. → High uranium concentrations are dissolved in water and precipitate subsequently. - Abstract: After the termination of phosphogypsum discharges to the Huelva estuary (SW Spain), a unique opportunity was presented to study the response of a contaminated environmental compartment after the cessation of its main source of pollution. The evolution over time of uranium concentrations in the estuary is presented to supply new insights into the decontamination of a scenario affected by Naturally Occurring Radioactive Material (NORM) discharges. The cleaning of uranium isotopes from the area has not taken place as rapidly as expected due to leaching from phosphogypsum stacks. An in-depth study using various techniques of analysis, including 234 U/ 238 U and 230 Th/ 232 Th ratios and the decreasing rates of the uranium concentration, enabled a second source of uranium contamination to be discovered. Increased uranium levels due to acid mine drainage from pyrite mines located in the Iberian Pyrite Belt (SW Spain) prevent complete uranium decontamination and, therefore, result in levels nearly twice those of natural background levels.

  13. Geochemistry of acid mine drainage and evaporated minerals in the Sangdong area

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cheon-Young; Jeong, Youn-Joong; Choi, Nag-Choul; Kang, Ji-Sung; Park, Shin-Sook; Kim, Seoung-Ku [Chosun University, Kwangju(Korea)

    2000-08-31

    This study investigated geochemical characteristics of acid mine drainage(AMD) discharged from the abandoned coal mine at the Sangdong area. Surface stream water samples were collected from 13 locations along Okdong creek. The yellowish and brown color of evaporated mineral was prepared by air dry for SJ-13 acid water sample during 121 days in the laboratory. As the SJ-13 acid water sample becomes fully drying, the concentration of this water become progressively more concentrated and its may be eventually reached saturation with respect to either gypsum or copiapite. At the upstream site, the Mg, Si, Ca, Fe, Mn, Al, Cr, Cu, Zn, As, Se, Cd, Se, Th, U, Fe and SO{sub 4} ion contents were relatively high but those contents decreased significantly with the distance from the coal mine. On the contrary, the Na, K and Cl ion contents were low in the upstream site, but those contents increased to the downstream. The value of saturation index for gypsum increase with increasing ion strength, TDS and TDI in this surface stream water. The x-ray powder diffraction studies identified that the evaporated minerals were well crystallized gypsum and copiapite. Diagnostic peaks used for identification of gypsum were the 7.62, 4.28 and 3.06 A.U. peaks. Diffraction peaks at 18.78, 9.30, 6.18, 4.51 and 3.58 A.U. may indicate copiapite. The IR absorption bands of evaporated mineral which indicated gypsum and copiapite were found from OH stretching, deformation of H{sub 2}O and SO{sub 4}{sup 2-} stretching vibration, respectively. In the SEM and EDS analysis, the crystals of acicular and columnar in the evaporated mineral probably shown the gypsum. The efflorescenting growth of thin tabular crystals and radiating clusters of fibrous crystals in the evaporated mineral may be identified as the copiapite. The fine-grained alabaster of crystals with large platy cleavable radiating of gypsum crystals were shown in EPMA. According to the EPMA analysis for gypsum, the atomic % ratios of Ca to S

  14. Isotope geochemistry of drainage from an acid mine impaired watershed, Oakland, California

    International Nuclear Information System (INIS)

    Butler, Thomas W.

    2007-01-01

    Oxidation of sulfides at the Leona Heights Sulfur Mine has resulted in the liberation of acid, SO 4 and metals to Leona Creek. Previous research at the site has indicated Fe(II) oxidation at rates faster than would be predicted by abiotic oxidation alone, particularly in the segment of stream between the Adit and Leona Street sample stations. In order to assess the mechanisms responsible for sulfide oxidation, samples were collected for isotopic analysis of water and SO 4 , the results of which were used to develop a stoichiometric isotope-balance model. This exercise indicated that the percentage of water-derived oxygen in SO 4 increased spatially from between 56% and 64% at the Adit to between 71% and 72% at Leona Street, illustrating that increased sulfide oxidation via Fe(III) was occurring within, or as water flows over, the waste rock, relative to water emanating directly from the former mine. The incorporation of water-derived oxygen in SO 4 during pyrite oxidation is a process controlled by Fe oxidizing bacteria such as A. ferrooxidans at low pH. The role of bacteria was further supported by estimates of the rate constant for Fe oxidation between sampling stations, yielding values that were approximately 10 6 faster than abiotic Fe oxidation alone. Stable isotopic analysis of water further indicates a close correlation of adit spring water to the local meteoric water line, while 3 H data indicate a groundwater apparent age, or time of travel from its primary zone of recharge, of 34 S data, in conjunction with reported albitized feldspars within the Leona Rhyolite host rock, indicate a magmatic origin of ore sulfur, contrary to previous interpretations at the site

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

    Science.gov (United States)

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

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    Sullivan, P.J.; Yelton, J.L.

    1988-01-01

    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 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. The results of 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

  18. Diatoms in acid mine drainage and their role in the formation of iron-rich stromatolites

    Energy Technology Data Exchange (ETDEWEB)

    Brake, S.S.; Hasiotis, S.T.; Dannelly, H.K. [Indiana State University, Terre Haute, IN (United States)

    2004-08-01

    Adverse conditions in the acid mine drainage (AMD) system at the Green Valley mine, Indiana, limit diatom diversity to one species, Nitzschia tubicola. It is present in three distinct microbial consortia: Euglena mutabilis-dominated biofilm, diatom-dominated biofilm, and diatom-exclusive biofilm. E. mutabilis dominates the most extensive biofilm, with lesser numbers of N. tubicola, other eukaryotes, and bacteria. Diatom-dominated biofilm occurs as isolated patches containing N. tubicola with minor fungal hyphae, filamentous algae, E. mutabilis, and bacteria. Diatom-exclusive biofilm is rare, composed entirely of N. tubicola. Diatom distribution is influenced by seasonal and intraseasonal changes in water temperature and chemistry. Diatoms are absent in winter due to cool water temperatures. In summer, isolated patchy communities are present due to warmer water temperatures. In 2001, the diatom community expanded its distribution following a major rainfall that temporarily diluted the effluent, creating hospitable conditions for diatom growth. After several weeks when effluent returned to preexisting conditions, the diatom biofilm retreated to isolated patches, and E. mutabilis biofilm flourished. Iron-rich stromatolites underlie the biofilms and consist of distinct laminae, recording spatial and temporal oscillations in physicochemical conditions and microbial activity. The stromatolites are composed of thin, wavy laminae with partially decayed E. mutabilis biofilm, representing microbial activity and iron precipitation under normal AMD conditions. Alternating with the wavy layers are thicker, porous, spongelike laminae composed of iron precipitated on and incorporated into radiating colonies of diatoms. These layers indicate episodic changes in water chemistry, allowing diatoms to temporarily dominate the system.

  19. Assessing the sustainability of acid mine drainage (AMD) treatment in South Africa.

    Science.gov (United States)

    Masindi, Vhahangwele; Chatzisymeon, Efthalia; Kortidis, Ioannis; Foteinis, Spyros

    2018-04-20

    The environmental sustainability of acid mine drainage (AMD) treatment at semi-industrial scale is examined by means of the life cycle assessment (LCA) methodology. An integrated process which includes magnesite, lime, soda ash and CO 2 bubbling treatment was employed to effectively treat, at semi-industrial scale, AMD originating from a coal mine in South Africa. Economic aspects are also discussed. AMD is a growing problem of emerging concern that cause detrimental effects to the environment and living organisms, including humans, and impose on development, health, access to clean water, thus also affect economic growth and cause social instability. Therefore, sustainable and cost effective treatment methods are required. A life cycle cost analysis (LCCA) revealed the viability of the system, since the levelized cost of AMD treatment can be as low as R112.78/m 3 (€7.60/m 3 or $9.35/m 3 ). Moreover, due to its versatility, the system can be used both at remote locales, at stand-alone mode (e.g. using solar energy), or can treat AMD at industrial scale, thus substantially improving community resilience at local and national level. In terms of environmental sustainability, 29.6 kg CO 2eq are emitted per treated m 3 AMD or its environmental footprint amount to 2.96 Pt/m 3 . South Africa's fossil-fuel depended energy mix and liquid CO 2 consumption were the main environmental hotspots. The total environmental footprint is reduced by 45% and 36% by using solar energy and gaseous CO 2 , respectively. Finally, AMD sludge valorisation, i.e. mineral recovery, can reduce the total environmental footprint by up to 12%. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Investigation of As(V) removal from acid mine drainage by iron (hydr) oxide modified zeolite.

    Science.gov (United States)

    Nekhunguni, Pfano Mathews; Tavengwa, Nikita Tawanda; Tutu, Hlanganani

    2017-07-15

    In this work, the synthesis of iron (hydr) oxide modified zeolite was achieved through precipitation of iron on the zeolite. The structure and surface morphology of iron (hydr) oxide modified zeolite (IHOMZ) was studied by scanning electron microscopy (SEM), coupled with an energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FT-IR) spectra. The efficiency of IHOMZ was then investigated through batch technique for the extraction of As(V) from mine waste water. The optimum parameters for maximum As(V) adsorption were: an initial As(V) concentration (10 mg L -1 ), adsorbent dosage (3.0 g), contact time (90 min) and temperature (53 °C). The initial pH of the solution had no compelling effect on As(V) adsorption by IHOMZ. However, adsorption capacity was significantly affected by the solution temperature with 53 °C registering the maximum removal efficiency. The thermodynamic parameters: Entropy (ΔS° = 0.00815 kJ (K mol) -1 ), variation of the Gibbs free energy (ΔG°) and enthalpy (ΔH° = 9.392 kJ mol -1 ) of As(V) adsorption onto IHOMZ system signified a non-spontaneous and endothermic process. It was noted that Freundlich isotherm model exhibited a better fit to the equilibrium experimental data, implying that the adsorption process occurred on a heterogeneous surface. The kinetic data from As(V) adsorption experiments was depicted by the pseudo-second-order kinetic model (R 2  > 0.999), suggesting a chemisorption adsorption process. The experimental batch equilibrium results indicated that IHOMZ could be used as an effective sorbent for As(V) ion extraction from acid mine drainage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Preservation procedures for arsenic speciation in a stream affected by acid mine drainage in southwestern Spain

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Rodas, Daniel; Oliveira, Vanesa; Gomez-Ariza, Jose Luis [University of Huelva, Department of Chemistry and Materials Science, Faculty of Experimental Sciences, Huelva (Spain); Sarmiento, Aguasanta M.; Nieto, Jose Miguel [University of Huelva, Department of Geology, Faculty of Experimental Sciences, Huelva (Spain)

    2006-04-15

    A preservation study has been performed for arsenic speciation in surface freshwaters affected by acid mine drainage (AMD), a pollution source characterized by low pH and high metallic content. Two sample preservation procedures described in the literature were attempted using opaque glass containers and refrigeration: i) addition of 0.25 mol L{sup -1} EDTA to the samples, which maintained the stability of the arsenic species for 3 h; and ii) in situ sample clean-up with a cationic exchange resin, in order to reduce the metallic load, which resulted in a partial co-adsorption of arsenic onto Fe precipitates. A new proposed method was also tried: sample acidification with 6 mol L{sup -1} HCl followed by in situ clean-up with a cationic exchange resin, which allowed a longer preservation time of at least 48 h. The proposed method was successfully applied to water samples with high arsenic content, taken from the Aguas Agrias Stream (Odiel River Basin, SW Spain), which is severely affected by AMD that originates at the nearby polymetallic sulfide mine of Tharsis. The speciation results obtained by liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS) indicated that during the summer the main arsenic species was As(V) at the hundred {mu}g L{sup -1} level, followed by DMA (dimethyl arsenic) and As(III) below the ten {mu}g L{sup -1} level. In winter, As(V) and As(III) increased at least fivefold, whereas the DMA was not detected. (orig.)

  2. Injection of FGD Grout to Abate Acid Mine Drainage in Underground Coal Mines

    Energy Technology Data Exchange (ETDEWEB)

    Mafi, S.; Damian, M.T.; Senita, R.E.; Jewitt, W.C.; Bair, S.; Chin, Y.C.; Whitlatch, E.; Traina, S.; Wolfe, W.

    1997-07-01

    Acid Mine Drainage (AMD) from abandoned underground coal mines in Ohio is a concern for both residents and regulatory agencies. Effluent from these mines is typically characterized by low pH and high iron and sulfate concentrations and may contaminate local drinking-water supplies and streams. The objective of this project is to demonstrate the technical feasibility of injecting cementitious alkaline materials, such as Flue Gas Desulfurization (FGD) material to mitigate current adverse environmental impacts associated with AMD in a small, abandoned deep mine in Coshocton County Ohio. The Flue Gas Desulfurization material will be provided from American Electric Power`s (AEP) Conesville Plant. It will be injected as a grout mix that will use Fixated Flue Gas Desulfurization material and water. The subject site for this study is located on the border of Coshocton and Muskingum Counties, Ohio, approximately 1.5 miles south-southwest of the town of Wills Creek. The study will be performed at an underground mine designated as Mm-127 in the Ohio Department of Natural Resources register, also known as the Roberts-Dawson Mine. The mine operated in the mid-1950s, during which approximately 2 million cubic feet of coal was removed. Effluent discharging from the abandoned mine entrances has low pH in the range of 2.8-3.0 that drains directly into Wills Creek Lake. The mine covers approximately 14.6 acres. It is estimated that 26,000 tons of FGD material will be provided from AEP`s Conesville Power Plant located approximately 3 miles northwest of the subject site.

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

    Energy Technology Data Exchange (ETDEWEB)

    Neculita, C.M.; Vigneaul, B.; Zagury, G.J. [Ecole Polytechnic, Montreal, PQ (Canada)

    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.

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

    Science.gov (United States)

    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.

  5. Trace metals of an acid mine drainage stream using a chemical model (WATEQ) and sediment analysis

    International Nuclear Information System (INIS)

    West, K.A.; Wilson, T.P.

    1992-01-01

    The high metal contents common to the discharge of acid-mine drainage (AMD) from mines and mine spoils is an environmental concern to both government and industry. This paper reports the results of investigation of the behavior of metals in an AMD system at a former surface coal mine in Tuscarawas County, Oh. AMD discharges from seeps travels, in respective order through a laminar flow stream; a Typha-dominated wetland; a turbulent flow stream; and a sediment retention pond. Dissolved metals (Fe, Mn, Zn, Cr, Cd, Cu, and Al) major and minor components, and other parameters (pH, dissolved oxygen and Eh) were measured in the AMD water at each sample location. A chemical mineral equilibrium model (WATEQ) was used to predict the minerals which should precipitate at each site. Results suggest that the seeps are supersaturated and should be precipitating hematite, goethite and magnetite (iron oxides), and siderite (iron carbonate), whereas water of the other downstream sites were at or below equilibrium conditions for these minerals. The hydrogeochemistry of the AMD was further studied using sequential chemical attacks on the precipitate sediment surface coatings, in order to determine metal concentrations in the exchangeable, carbonate, Fe-Mn oxyhydroxide, and oxidizable fractions. The carbonate and exchangeable fractions of the precipitate are dominated by Ca and Fe, as well as Mg in the carbonate fraction. The Fe-Mn oxyhydroxide fraction contained Fe, Al, Mn, Mg, and trace metals, and also contained the greatest concentration of total elements in the system. The Fe-Mn oxyhydroxide is therefore, the major sink for metals of this AMD system. The decrease in the concentration of metals in the sediment precipitates in the downstream locations, is consistent with WATEQ and water analysis results

  6. Injection of FGD Grout to Abate Acid Mine Drainage in Underground Coal Mines

    International Nuclear Information System (INIS)

    Mafi, S.; Damian, M.T.; Senita, R.E.; Jewitt, W.C.; Bair, S.; Chin, Y.C.; Whitlatch, E.; Traina, S.; Wolfe, W.

    1997-07-01

    Acid Mine Drainage (AMD) from abandoned underground coal mines in Ohio is a concern for both residents and regulatory agencies. Effluent from these mines is typically characterized by low pH and high iron and sulfate concentrations and may contaminate local drinking-water supplies and streams. The objective of this project is to demonstrate the technical feasibility of injecting cementitious alkaline materials, such as Flue Gas Desulfurization (FGD) material to mitigate current adverse environmental impacts associated with AMD in a small, abandoned deep mine in Coshocton County Ohio. The Flue Gas Desulfurization material will be provided from American Electric Power's (AEP) Conesville Plant. It will be injected as a grout mix that will use Fixated Flue Gas Desulfurization material and water. The subject site for this study is located on the border of Coshocton and Muskingum Counties, Ohio, approximately 1.5 miles south-southwest of the town of Wills Creek. The study will be performed at an underground mine designated as Mm-127 in the Ohio Department of Natural Resources register, also known as the Roberts-Dawson Mine. The mine operated in the mid-1950s, during which approximately 2 million cubic feet of coal was removed. Effluent discharging from the abandoned mine entrances has low pH in the range of 2.8-3.0 that drains directly into Wills Creek Lake. The mine covers approximately 14.6 acres. It is estimated that 26,000 tons of FGD material will be provided from AEP's Conesville Power Plant located approximately 3 miles northwest of the subject site

  7. Development of a diatom-based multimetric index for acid mine drainage impacted depressional wetlands.

    Science.gov (United States)

    Riato, Luisa; Leira, Manel; Della Bella, Valentina; Oberholster, Paul J

    2018-01-15

    Acid mine drainage (AMD) from coal mining in the Mpumalanga Highveld region of South Africa has caused severe chemical and biological degradation of aquatic habitats, specifically depressional wetlands, as mines use these wetlands for storage of AMD. Diatom-based multimetric indices (MMIs) to assess wetland condition have mostly been developed to assess agricultural and urban land use impacts. No diatom MMI of wetland condition has been developed to assess AMD impacts related to mining activities. Previous approaches to diatom-based MMI development in wetlands have not accounted for natural variability. Natural variability among depressional wetlands may influence the accuracy of MMIs. Epiphytic diatom MMIs sensitive to AMD were developed for a range of depressional wetland types to account for natural variation in biological metrics. For this, we classified wetland types based on diatom typologies. A range of 4-15 final metrics were selected from a pool of ~140 candidate metrics to develop the MMIs based on their: (1) broad range, (2) high separation power and (3) low correlation among metrics. Final metrics were selected from three categories: similarity to reference sites, functional groups, and taxonomic composition, which represent different aspects of diatom assemblage structure and function. MMI performances were evaluated according to their precision in distinguishing reference sites, responsiveness to discriminate reference and disturbed sites, sensitivity to human disturbances and relevancy to AMD-related stressors. Each MMI showed excellent discriminatory power, whether or not it accounted for natural variation. However, accounting for variation by grouping sites based on diatom typologies improved overall performance of MMIs. Our study highlights the usefulness of diatom-based metrics and provides a model for the biological assessment of depressional wetland condition in South Africa and elsewhere. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Chemical characterisation of natural organic substrates for biological mitigation of acid mine drainage.

    Science.gov (United States)

    Gibert, Oriol; de Pablo, Joan; Luis Cortina, José; Ayora, Carlos

    2004-11-01

    The current approach of the biological treatment of acid mine drainage by means of a passive remediation system involves the choice of an appropriate organic substrate as electron donor for sulphate reducers. Nowadays this selection is one of the critical steps in the performance of such treatment, as this depends to a great extent on the degradability of the organic substrate. Thus, a prior characterisation of the organic substrate predicting its biodegradability would be desirable before embarking on an extensive large-scale application. The aim of this study was to correlate the chemical composition (lignin content) of four different natural organic substrates (compost, sheep and poultry manures, oak leaf) and their capacity to sustain bacterial activity in an attempt to predict biodegradation from chemical characterisation. The results showed that the lower the content of lignin in the organic substrate, the higher its biodegradability and capacity for developing bacterial activity. Of the four organic materials, sheep and poultry manures and oak leaf evolved reducing conditions and sustained active sulphidogenesis, which coupled with the decrease in sulphate concentration indicated bacterial activity. Sheep manure was clearly the most successful organic material as electron donor (sulphate removal >99%), followed by poultry manure and oak leaf (sulphate removal of 80%). Compost appeared to be too poor in carbon to promote sulphate-reducing bacteria activity by itself. Column experiments emphasised the importance of considering the residence time as a key factor in the performance of continuous systems. With a residence time of 0.73 days, sheep manure did not promote sulphidogenesis. However, extending residence time to 2.4 and 9.0 days resulted in an increase in the sulphate removal to 18% and 27%, respectively.

  9. The impacts of neutralized acid mine drainage contaminated water on the expression of selected endocrine-linked genes in juvenile Mozambique tilapia Oreochromis mossambicus exposed in vivo

    CSIR Research Space (South Africa)

    Truter, JC

    2014-02-01

    Full Text Available Acid mine drainage (AMD) is a global environmental concern due to detrimental impacts on river ecosystems. Little is however known regarding the biological impacts of neutralized AMD on aquatic vertebrates despite excessive discharge...

  10. Synthesis of porous magnesite-bentonite clay composite and its application for neutralisation and attenuation of inorganic contaminants in acidic and metalliferous mine drainage

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2015-08-01

    Full Text Available This paper evaluated the application of cryptocrystalline magnesite-bentonite clay composite for treatment of acid mine drainage (AMD). Bench laboratory studies were used to evaluate the treatment of AMD....

  11. Biogeochemistry of the compost bioreactor components of a composite acid mine drainage passive remediation system

    International Nuclear Information System (INIS)

    Johnson, D. Barrie; Hallberg, Kevin B.

    2005-01-01

    The compost bioreactor ('anaerobic cell') components of three composite passive remediation systems constructed to treat acid mine drainage (AMD) at the former Wheal Jane tin mine, Cornwall, UK were studied over a period of 16 months. While there was some amelioration of the preprocessed AMD in each of the three compost bioreactors, as evidenced by pH increase and decrease in metal concentrations, only one of the cells showed effective removal of the two dominant heavy metals (iron and zinc) present. With two of the compost bioreactors, concentrations of soluble (ferrous) iron draining the cells were significantly greater than those entering the reactors, indicating that there was net mobilisation (by reductive dissolution) of colloidal and/or solid-phase ferric iron compounds within the cells. Soluble sulfide was also detected in waters draining all three compost bioreactors which was rapidly oxidised, in contrast to ferrous iron. Oxidation and hydrolysis of iron, together with sulfide oxidation, resulted in reacidification of processed AMD downstream of the compost bioreactors in two of the passive treatment systems. The dominant cultivatable microorganism in waters draining the compost bioreactors was identified, via analysis of its 16S rRNA gene, as a Thiomonas sp. and was capable of accelerating the dissimilatory oxidation of both ferrous iron and reduced sulfur compounds. Sulfate-reducing bacteria (SRB) were also detected, although only in the bioreactor that was performing well were these present in significant numbers. This particular compost bioreactor had been shut down for 10 months prior to the monitoring period due to operational problems. This unforeseen event appears to have allowed more successful development of AMD-tolerant and other microbial populations with critical roles in AMD bioremediation, including neutrophilic SRB (nSRB), in this compost bioreactor than in the other two, where the throughput of AMD was not interrupted. This study has

  12. Drone-Borne Hyperspectral Monitoring of Acid Mine Drainage: An Example from the Sokolov Lignite District

    Directory of Open Access Journals (Sweden)

    Robert Jackisch

    2018-03-01

    Full Text Available This contribution explores the potential of unmanned aerial systems (UAS to monitor areas affected by acid mine drainage (AMD. AMD is an environmental phenomenon that usually develops in the vicinity of mining operations or in post-mining landscapes. The investigated area covers a re-cultivated tailing in the Sokolov lignite district of the Czech Republic. A high abundance of AMD minerals occurs in a confined space of the selected test site and illustrates potential environmental issues. The mine waste material contains pyrite and its consecutive weathering products, mainly iron hydroxides and oxides. These affect the natural pH values of the Earth’s surface. Prior research done in this area relies on satellite and airborne data, and our approach focuses on lightweight drone systems that enables rapid deployment for field campaigns and consequently-repeated surveys. High spatial image resolutions and precise target determination are additional advantages. Four field and flight campaigns were conducted from April to September 2016. For validation, the waste heap was probed in situ for pH, X-ray fluorescence (XRF, and reflectance spectrometry. Ground truth was achieved by collecting samples that were characterized for pH, X-ray diffraction, and XRF in laboratory conditions. Hyperspectral data were processed and corrected for atmospheric, topographic, and illumination effects using accurate digital elevation models (DEMs. High-resolution point clouds and DEMs were built from drone-borne RGB data using structure-from-motion multi-view-stereo photogrammetry. The supervised classification of hyperspectral image (HSI data suggests the presence of jarosite and goethite minerals associated with the acidic environmental conditions (pH range 2.3–2.8 in situ. We identified specific iron absorption bands in the UAS-HSI data. These features were confirmed by ground-truth spectroscopy. The distribution of in situ pH data validates the UAS-based mineral

  13. Biogeochemistry of the compost bioreactor components of a composite acid mine drainage passive remediation system.

    Science.gov (United States)

    Johnson, D Barrie; Hallberg, Kevin B

    2005-02-01

    The compost bioreactor ("anaerobic cell") components of three composite passive remediation systems constructed to treat acid mine drainage (AMD) at the former Wheal Jane tin mine, Cornwall, UK were studied over a period of 16 months. While there was some amelioration of the preprocessed AMD in each of the three compost bioreactors, as evidenced by pH increase and decrease in metal concentrations, only one of the cells showed effective removal of the two dominant heavy metals (iron and zinc) present. With two of the compost bioreactors, concentrations of soluble (ferrous) iron draining the cells were significantly greater than those entering the reactors, indicating that there was net mobilisation (by reductive dissolution) of colloidal and/or solid-phase ferric iron compounds within the cells. Soluble sulfide was also detected in waters draining all three compost bioreactors which was rapidly oxidised, in contrast to ferrous iron. Oxidation and hydrolysis of iron, together with sulfide oxidation, resulted in reacidification of processed AMD downstream of the compost bioreactors in two of the passive treatment systems. The dominant cultivatable microorganism in waters draining the compost bioreactors was identified, via analysis of its 16S rRNA gene, as a Thiomonas sp. and was capable of accelerating the dissimilatory oxidation of both ferrous iron and reduced sulfur compounds. Sulfate-reducing bacteria (SRB) were also detected, although only in the bioreactor that was performing well were these present in significant numbers. This particular compost bioreactor had been shut down for 10 months prior to the monitoring period due to operational problems. This unforeseen event appears to have allowed more successful development of AMD-tolerant and other microbial populations with critical roles in AMD bioremediation, including neutrophilic SRB (nSRB), in this compost bioreactor than in the other two, where the throughput of AMD was not interrupted. This study has

  14. WATER DRAINAGE MODEL

    International Nuclear Information System (INIS)

    Case, J.B.

    2000-01-01

    The drainage of water from the emplacement drift is essential for the performance of the EBS. The unsaturated flow properties of the surrounding rock matrix and fractures determine how well the water will be naturally drained. To enhance natural drainage, it may be necessary to introduce engineered drainage features (e.g. drilled holes in the drifts), that will ensure communication of the flow into the fracture system. The purpose of the Water Drainage Model is to quantify and evaluate the capability of the drift to remove water naturally, using the selected conceptual repository design as a basis (CRWMS M andO, 1999d). The analysis will provide input to the Water Distribution and Removal Model of the EBS. The model is intended to be used to provide postclosure analysis of temperatures and drainage from the EBS. It has been determined that drainage from the EBS is a factor important to the postclosure safety case

  15. A coupled hydrodynamic-hydrochemical modeling for predicting mineral transport in a natural acid drainage system.

    Science.gov (United States)

    Zegers Risopatron, G., Sr.; Navarro, L.; Montserrat, S., Sr.; McPhee, J. P.; Niño, Y.

    2017-12-01

    The geochemistry of water and sediments, coupled with hydrodynamic transport in mountainous channels, is of particular interest in central Chilean Andes due to natural occurrence of acid waters. In this paper, we present a coupled transport and geochemical model to estimate and understand transport processes and fate of minerals at the Yerba Loca Basin, located near Santiago, Chile. In the upper zone, water presentes low pH ( 3) and high concentrations of iron, aluminum, copper, manganese and zinc. Acidity and minerals are the consequence of water-rock interactions in hydrothermal alteration zones, rich in sulphides and sulphates, covered by seasonal snow and glaciers. Downstream, as a consequence of neutral to alkaline lateral water contributions (pH >7) along the river, pH increases and concentration of solutes decreases. The mineral transport model has three components: (i) a hydrodynamic model, where we use HEC-RAS to solve 1D Saint-Venant equations, (ii) a sediment transport model to estimate erosion and sedimentation rates, which quantify minerals transference between water and riverbed and (iii) a solute transport model, based on the 1D OTIS model which takes into account the temporal delay in solutes transport that typically is observed in natural channels (transient storage). Hydrochemistry is solved using PHREEQC, a software for speciation and batch reaction. Our results show that correlation between mineral precipitation and dissolution according to pH values changes along the river. Based on pH measurements (and according to literature) we inferred that main minerals in the water system are brochantite, ferrihydrite, hydrobasaluminite and schwertmannite. Results show that our model can predict the transport and fate of minerals and metals in the Yerba Loca Basin. Mineral dissolution and precipitation process occur for limited ranges of pH values. When pH values are increased, iron minerals (schwertmannite) are the first to precipitate ( 2.5

  16. The 2005 catastrophic acid crater lake drainage, lahar, and acidic aerosol formation at Mount Chiginagak volcano, Alaska, USA: Field observations and preliminary water and vegetation chemistry results

    Science.gov (United States)

    Schaefer, J.R.; Scott, W.E.; Evans, William C.; Jorgenson, J.; McGimsey, R.G.; Wang, B.

    2008-01-01

    A mass of snow and ice 400-m-wide and 105-m-thick began melting in the summit crater of Mount Chiginagak volcano sometime between November 2004 and early May 2005, presumably owing to increased heat flux from the hydrothermal system, or possibly from magma intrusion and degassing. In early May 2005, an estimated 3.8??106 m3 of sulfurous, clay-rich debris and acidic water, with an accompanying acidic aerosol component, exited the crater through a tunnel at the base of a glacier that breaches the south crater rim. Over 27 km downstream, the acidic waters of the flood inundated an important salmon spawning drainage, acidifying Mother Goose Lake from surface to depth (approximately 0.5 km3 in volume at a pH of 2.9 to 3.1), killing all aquatic life, and preventing the annual salmon run. Over 2 months later, crater lake water sampled 8 km downstream of the outlet after considerable dilution from glacial meltwater was a weak sulfuric acid solution (pH = 3.2, SO4 = 504 mg/L, Cl = 53.6 mg/L, and F = 7.92 mg/L). The acid flood waters caused severe vegetation damage, including plant death and leaf kill along the flood path. The crater lake drainage was accompanied by an ambioructic flow of acidic aerosols that followed the flood path, contributing to defoliation and necrotic leaf damage to vegetation in a 29 km2 area along and above affected streams, in areas to heights of over 150 m above stream level. Moss species killed in the event contained high levels of sulfur, indicating extremely elevated atmospheric sulfurcontent. The most abundant airborne phytotoxic constituent was likely sulfuric acid aerosols that were generated during the catastrophic partial crater lake drainage event. Two mechanisms of acidic aerosol formation are proposed: (1) generation of aerosol mist through turbulent flow of acidic water and (2) catastrophic gas exsolution. This previously undocumented phenomenon of simultaneous vegetationdamaging acidic aerosols accompanying drainage of an acidic crater

  17. Remediation of acid mine drainage from the Santa Fe tin mine, Bolivia

    Science.gov (United States)

    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

  18. Biological attenuation of arsenic and iron in a continuous flow bioreactor treating acid mine drainage (AMD).

    Science.gov (United States)

    Fernandez-Rojo, L; Héry, M; Le Pape, P; Braungardt, C; Desoeuvre, A; Torres, E; Tardy, V; Resongles, E; Laroche, E; Delpoux, S; Joulian, C; Battaglia-Brunet, F; Boisson, J; Grapin, G; Morin, G; Casiot, C

    2017-10-15

    Passive water treatments based on biological attenuation can be effective for arsenic-rich acid mine drainage (AMD). However, the key factors driving the biological processes involved in this attenuation are not well-known. Here, the efficiency of arsenic (As) removal was investigated in a bench-scale continuous flow channel bioreactor treating As-rich AMD (∼30-40 mg L -1 ). In this bioreactor, As removal proceeds via the formation of biogenic precipitates consisting of iron- and arsenic-rich mineral phases encrusting a microbial biofilm. Ferrous iron (Fe(II)) oxidation and iron (Fe) and arsenic removal rates were monitored at two different water heights (4 and 25 mm) and with/without forced aeration. A maximum of 80% As removal was achieved within 500 min at the lowest water height. This operating condition promoted intense Fe(II) microbial oxidation and subsequent precipitation of As-bearing schwertmannite and amorphous ferric arsenate. Higher water height slowed down Fe(II) oxidation, Fe precipitation and As removal, in relation with limited oxygen transfer through the water column. The lower oxygen transfer at higher water height could be partly counteracted by aeration. The presence of an iridescent floating film that developed at the water surface was found to limit oxygen transfer to the water column and delayed Fe(II) oxidation, but did not affect As removal. The bacterial community structure in the biogenic precipitates in the bottom of the bioreactor differed from that of the inlet water and was influenced to some extent by water height and aeration. Although potential for microbial mediated As oxidation was revealed by the detection of aioA genes, removal of Fe and As was mainly attributable to microbial Fe oxidation activity. Increasing the proportion of dissolved As(V) in the inlet water improved As removal and favoured the formation of amorphous ferric arsenate over As-sorbed schwertmannite. This study proved the ability of this bioreactor

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

    Science.gov (United States)

    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

  20. Effects of acid mine drainage on dissolved inorganic carbon and stable carbon isotopes in receiving streams

    International Nuclear Information System (INIS)

    Fonyuy, Ernest W.; Atekwana, Eliot A.

    2008-01-01

    Dissolved inorganic carbon (DIC) constitutes a significant fraction of a stream's carbon budget, yet the role of acid mine drainage (AMD) in DIC dynamics in receiving streams remains poorly understood. The objective of this study was to evaluate spatial and temporal effects of AMD and its chemical evolution on DIC and stable isotope ratio of DIC (δ 13 C DIC ) in receiving streams. We examined spatial and seasonal variations in physical and chemical parameters, DIC, and δ 13 C DIC in a stream receiving AMD. In addition, we mixed different proportions of AMD and tap water in a laboratory experiment to investigate AMD dilution and variable bicarbonate concentrations to simulate downstream and seasonal hydrologic conditions in the stream. Field and laboratory samples showed variable pH, overall decreases in Fe 2+ , alkalinity, and DIC, and variable increase in δ 13 C DIC . We attribute the decrease in alkalinity, DIC loss, and enrichment of 13 C of DIC in stream water to protons produced from oxidation of Fe 2+ followed by Fe 3+ hydrolysis and precipitation of Fe(OH) 3(s) . The extent of DIC decrease and 13 C enrichment of DIC was related to the amount of HCO 3 - dehydrated by protons. The laboratory experiment showed that lower 13 C enrichment occurred in unmixed AMD (2.7 per mille ) when the amount of protons produced was in excess of HCO 3 - or in tap water (3.2 per mille ) where no protons were produced from Fe 3+ hydrolysis for HCO 3 - dehydration. The 13 C enrichment increased and was highest for AMD-tap water mixture (8.0 per mille ) where Fe 2+ was proportional to HCO 3 - concentration. Thus, the variable downstream and seasonal 13 C enrichment in stream water was due in part to: (1) variations in the volume of stream water initially mixed with AMD and (2) to HCO 3 - input from groundwater and seepage in the downstream direction. Protons produced during the chemical evolution of AMD caused seasonal losses of 50 to >98% of stream water DIC. This loss of DIC

  1. Development and Validation of an Acid Mine Drainage Treatment Process for Source Water

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Ann [Battelle Memorial Institute, Columbus, OH (United States)

    2016-03-01

    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

  2. Using a mass balance to understand the geology and geochemistry of a reservoir receiving and discharging acid mine drainage

    International Nuclear Information System (INIS)

    Turney, D.C.; Edwards, K.

    1996-01-01

    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 3 , total alkalinity as CaCO 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

  3. Effect Of Imposed Anaerobic Conditions On Metals Release From Acid-Mine Drainage Contaminated Streambed Sediments

    Science.gov (United States)

    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...

  4. Isotope geochemistry of waters affected by acid mine drainage in old labour sites (SE, Spain).

    Science.gov (United States)

    Pérez-Sirvent, Carmen; Martinez-Sanchez, Maria Jose; Garcia-Lorenzo, Maria Luz; Agudo, Ines; Hernandez-Cordoba, Manuel; Recio, Clemente

    2015-04-01

    The ore deposits of this zone have iron, lead and zinc as the main metal components. Iron is present in oxides, hydroxides, sulfides, sulfates, carbonates, and silicates; lead and zinc occur in sulfides (galena and sphalerite, respectively), carbonates, sulfates, and lead or zinc-bearing (manganese, iron) oxides. Mining started with the Romans and activity peaked in the second half of the 19th century and throughout the 20th century until the 1980's. From 1940 to 1957, mineral concentration was made by froth flotation and, prior to this, by gravimetric techniques. The mining wastes, or tailings, with a very fine particle size were deposited inland (tailings dams) and, since 1957, huge releases were made in directly the sea coast. The objective of this work was to evaluate processes affecting waters from abandoned mine sites by way of stable isotopic analysis, particularly H and O stable isotopes from water and S and O from dissolved sulfates. Several common chemical and physical processes, such as evaporation, water-rock interaction and mixing could alter water isotopic composition. Evaporation, which causes an enrichment in δD and δ18O in the residual water, is an important process in semiarid areas. The results obtained indicate that, for sites near the coast, waters are meteoric, and marine infiltration only takes place in the deepest layers near the shore or if water remains stagnated in sediments with low permeability. The main source of sulfate was the oxidation of sulfides, resulting in the liberation of acid, sulfate and metals. In order to assess the mechanism responsible for sulfide oxidation, the stoichiometric isotope balance model and the general isotope balance model were tested, suggesting that the oxidation via Fe3+ was predominant in the surface, and controlled by A. ferrooxidans, while at depth, sulfate reduction occurred.

  5. Contribution to the study of the weathering rate of minerals and rocks in the drainage basin of the Paraguacu river - Bahia - Brazil

    International Nuclear Information System (INIS)

    Novaes, A.B.

    1978-12-01

    The concentrations of Na + , Mg ++ , Ca ++ , K + , SiO 2 , SO sup(=) 4 , alcalinity and pH have been determined for twenty-nine surface water samples of the Paraguacu river drainage basin, mainly in the Utinga River sub-basin. The stable isotope ratio of carbon 13 C/ 12 C as well as concentration of 14 C was determined for some samples. The ion influence on local aerosol chemistry has also been subtracted from all samples. The analytical results were used to determine the current rate of weathering the rocks of this region and study the sources of dissolved carbon in this water. The analysis of the data shows that weathering processes are influenced by the local lithology. The data from them Utinga river suggests that dissolution of limestone contributes a large percentage of ions. The influence of groundwater in the river flow also brings high concentrations of Na + , Mg ++ and Ca ++ ions from aerosols, presumeably concentrated by evapo-transpiration. The presence of aerosols in the samples used is remarkable, the contribution of salts from silicate weathering is rather small. It is proposed that the dissolution of limestone and decomposition of organic matter might explain the origin of carbon in some of the samples but others appear to have suffered equilibration with atmospheric CO 2 . (Author) [pt

  6. Adsorption Kinetics of Fe and Mn with Using Fly Ash from PT Semen Baturaja in Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Indah Purnamasari

    2017-11-01

    Full Text Available One used method to reduce heavy metal ions in acid mine drainage is to adsorb them by coal fly ash. This research aimed to study the isotherms equilibrium and the adsorpstion kinetics that fit with decreasing metals ion. Acid mine draigane and fly ash were charge into batch coloumn adsorption with specified comparison. Variables investigated were dactivated and activated fly ash, adsorption times (0, 20, 30, 40,50, and 60 minutes, adsorben weights (10, 20, 30, 40, 50, and 60 gram, and pH (1, 3, 5, 7, and 9. The results showed that fly ash can be used to reduce the levels of heavy metal ions Fe and Mn. Coal fly ash adsorption model of acid mine drainage fits to Freundlich adsorption isotherm in all condition. First order pseudo model kinetics is suitable for Fe and Mn adsorption processes. The value of adsorpsi rate constants vary around : Fe and Mn (deactivated fly ash 0.2388 min-1 with R2 = 0.4455 and 0.4173 min-1 with R2 = 0.9781, Fe and Mn (activated fly ash 0.5043 min-1 dengan R2 = 1 and  0.2027 min-1 with R2 = 0.8803.

  7. Sustainable rehabilitation of mining waste and acid mine drainage using geochemistry, mine type, mineralogy, texture, ore extraction and climate knowledge.

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Effect of ursodeoxycholic acid on bile secretion after endoscopic nasobiliary drainage in patients with cholestatic liver disease of various causes

    Directory of Open Access Journals (Sweden)

    LI Lei

    2016-03-01

    Full Text Available ObjectiveTo observe the effect of ursodeoxycholic acid (UDCA on bile secretion in patients with cholestatic liver disease of various causes. MethodsA total of 48 patients who underwent endoscopic nasobiliary drainage (ENBD in Beijing You′an Hospital Affiliated to Capital Medical University from July 2013 to May 2014 were enrolled and divided into UDCA treatment group (n=36 and control group (n=12. The patients in the UDCA group were further divided into common bile duct stone group (n=9, cholangiocarcinoma group (n=7, sclerosing cholangitis group (n=7, and post-liver transplantation group (n=13. The patients in the UDCA treatment group received oral UDCA capsules (250 mg, 3 times/day since the second day after surgery, and the daily volume of bile drainage was recorded for 7 days after surgery. Serum levels of total bilirubin (TBil, total bile acid (TBA, gamma-glutamyl transpeptidase (GGT, and alkaline phosphatase (ALP were measured on the day before surgery and the 7th day after surgery, and the effects of UDCA on volume of bile drainage, TBil, TBA, GGT, and ALP were compared between groups. The t-test was applied for comparison between groups, comparison of continuous data between these groups was made by analysis of variance; the chi-square test was applied for comparison of categorical data between groups. ResultsCompared with the control group, the UDCA treatment group had a significantly increased volume of bile drainage on the 3rd, 4th, and 5th days after surgery (t=2.461, 3.896, and 2.760; P=0.048, 0.021, and 0.034, and the increase in volume of bile drainage was more significant in the common bile duct stone group, the cholangiocarcinoma group, and the post-liver transplantation group, with peak values appearing on the 4th day after surgery. The patients in the common bile duct stone group and the post-liver transplantation group had significantly lower serum levels of TBil, GGT, and ALP on the 7th day after surgery (t=3.340, 2

  9. Drainage, liming and fertilization of organic soils. 1. Long-term effects on acid/base relations

    International Nuclear Information System (INIS)

    Braekke, F.H.

    1999-01-01

    Long-term changes of the acid/base relations of organic soils after drainage, fertilization and/or liming at three experimental sites - two ombrogenous and one soligenous - in south-central Norway are discussed. These sites were drained, fertilized and/or limed in 1953-1956 and sampled in 1991-1992. Drainage at the ombrogenous sites caused: insignificant shifts of pH, higher bulk densities to 40 cm depth, higher ash percentage, higher contents of N and P to 20 cm depth and reduced concentrations of total Ca, K, Mg, Na, Al and Fe in soil layers deeper than 20 cm. The soligenous site was not effectively drained; despite this, pH dropped about 0.5 unit in the surface and subsurface soil layers of the control plots, while small changes were measured for most other soil variables. The suggested reason for the pH drop is limited sulphide oxidation in the upper 20 cm drained layer. Base saturation at actual soil pH, when all treatments were included, was estimated with good precision by four regressors: pH, extractable Al, extractable Fe and extractable Ca (R 2 = 0.90-0.95). Similar models explained 97-99% of the variation in base saturation at soil pH = 7.0. The lime effects at the properly drained oligotrophic sites were proportional to applied doses; for pH to 40 cm, base saturation to 60 cm, and Ca concentration to 60 cm depth. At the less well-drained soligenous site, effects were limited to the upper 30 cm layer. Both drainage and liming caused higher cation exchange capacities and proper drainage seems to be a prerequisite for the liming effect. Estimated recovery of calcium to 60 cm depth was 64-79% at the ombrogenous sites and 42-46% at the soligenous site 28 refs, 3 figs, 8 tabs

  10. Role of dissimilatory sulfate reduction in wetlands constructed for acid coal mine drainage (AMD) treatment. Master's thesis

    International Nuclear Information System (INIS)

    Taddeo, F.J.

    1991-01-01

    Five constructed wetlands with different organic substrates were exposed to the same quantity/quality of acid mine drainage (AMD). During the 16-month exposure to AMD, all wetlands accumulated S in the forms of organic and reduced inorganic S and Fe in the form of iron sulfides. Iron sulfide and probably most of the organic S(C-bonded S) accumulation were end products of bacterial dissimilatory sulfate reduction. Results of study support the notion that sulfate reduction and accumulation of Fe sulfides contribute to Fe retention in wetlands exposed to AMD. Detailed information is provided

  11. Quantifying heavy metals sequestration by sulfate-reducing bacteria in an acid mine drainage-contaminated wetland

    Directory of Open Access Journals (Sweden)

    John W Moreau

    2013-03-01

    Full Text Available 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.

  12. The potential of acidophilic macroalgae as part of passive bioremediation technology for acid mine drainage in constructed wetlands

    CSIR Research Space (South Africa)

    Cheng, Po-Hsun

    2012-10-01

    Full Text Available macroalgae as part of passive bioremediation technology for acid mine drainage in constructed wetlands PH CHENG1,3, PJ OBERHOLSTER1,2, A-M BOTHA3 1CSIR Natural Resources and the Environment, PO Box 320, Stellenbosch, 7599, South Africa 2Department... of diverse benthic algal species to AMD provides the option to utilise them in AMD remediation as part of passive bioremediation technology in constructed wetlands. The purpose of the study was to investigate the bioaccumulation of metals and trace metal...

  13. Reexamination of the source material of acid igneous rocks, based on the selected Sr isotopic data

    International Nuclear Information System (INIS)

    Kagami, Hiroo; Shuto, Kenji; Gorai, Masao

    1975-01-01

    The relation between the ages and the initial strontium isotopic compositions obtained from acid igneous rocks by the whole-rock isochron method is re-examined, on the basis of the selected data. The points based on the data having high values of standard deviation (on the isochrons) show considerable scattering. This is probably ascribed to admixture of sialic materials, or secondary alteration and other geologic causes. The points based on the data having lower values of standard deviation (sigma value: 0.0001 - 0.0019), on the other hand, are evidently plotted within a narrow region just above the presumed Sr evolutional region of the source material of oceanic tholeiites. It is noteworthy that the former region meets the latter region at an earlier stage of the evolutional history of the earth (about 40 x 10 8 yrs. ago or older). It may be conceivable that the former region is the Sr evolutional region of the source material of acid igneous rocks. Considering from the inclination of the above Sr evolutional region, the source material of most of acid igneous rocks may possibly be a certain basic material, chemically similar to the continental tholeiitic basalts or basaltic andesites. On the other hand, the source material of a few acid igneous rocks with low initial strontium isotopic ratios may be a certain basic material resembling the oceanic tholeiites. Another possibility is that these acid igneous rocks and oceanic tholeiites may have been formed, under different physical conditions, directly from a certain common source material presumably of peridotitic composition. (auth.)

  14. Flow and geochemical modeling of drainage from Tomitaka mine, Miyazaki, Japan.

    Science.gov (United States)

    Yamaguchi, Kohei; Tomiyama, Shingo; Metugi, Hideya; Ii, Hiroyuki; Ueda, Akira

    2015-10-01

    The chemistry and flow of water in the abandoned Tomitaka mine of Miyazaki, western Japan were investigated. This mine is located in a non-ferrous metal deposit and acid mine drainage issues from it. The study was undertaken to estimate the quantities of mine drainage that needs to be treated in order to avoid acidification of local rivers, taking into account seasonal variations in rainfall. Numerical models aimed to reproduce observed water levels and fluxes and chemical variations of groundwater and mine drainage. Rock-water interactions that may explain the observed variations in water chemistry are proposed. The results show that: (1) rain water infiltrates into the deeper bedrock through a highly permeable zone formed largely by stopes that are partially filled with spoil from excavations (ore minerals and host rocks); (2) the water becomes acidic (pH from 3 to 4) as dissolved oxygen oxidizes pyrite; (3) along the flow path through the rocks, the redox potential of the water becomes reducing, such that pyrite becomes stable and pH of the mine drainage becomes neutral; and (4) upon leaving the mine, the drainage becomes acidic again due to oxidation of pyrite in the rocks. The present numerical model with considering of the geochemical characteristics can simulate the main variations in groundwater flow and water levels in and around the Tomitaka mine, and apply to the future treatment of the mine drainage. Copyright © 2015. Published by Elsevier B.V.

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

    Institute of Scientific and Technical Information of China (English)

    Huarong Zhao; Beicheng Xia; Jianqiao Qin; Jiaying Zhang

    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 initial water 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 SO42- and high heavy metal content and oxidation as determined by the Fe2+/Fe3+ couple.Heavy metal and SO42- 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.

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

    Science.gov (United States)

    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

  17. Fate of pollutants post treatment of acid mine drainage with basic oxygen furnace slag: Validation of experimental results with a geochemical model

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2017-01-01

    Full Text Available (PRK) for the remediation of acid mine drainage. J. Hazard. Mater. 301, 332–341. Madzivire, G., Gitari, W.M., Vadapalli, V.R.K., Ojumu, T.V., Petrik, L.F., 2011. Fate of sulphate removed during the treatment of circumneutral mine water and acid mine...

  18. Formation of hydroxyl radical (sm-bulletOH) in illuminated surface waters contaminated with acidic mine drainage

    International Nuclear Information System (INIS)

    Allen, J.M.; Lucas, S.; Allen, S.K.

    1996-01-01

    Formation rates and steady-state concentrations of hydroxyl radical ( sm-bullet OH) in illuminated surface water samples collected in west-central Indiana that receive acidic mine drainage runoff are reported. Formation rates for sm-bullet OH in samples were measured by the addition of 1 x 10 -3 M benzene prior to illuminate in order to effectively scavenge all of the sm-bullet OH formed, thereby yielding phenol. The sm-bullet OH formation rates were calculated from the measured phenol formation rates. Steady-state concentrations of sm-bullet OH were measured by the addition of 5 x 10 -7 M nitrobenzene to the samples prior to illumination. Estimated sunlight sm-bullet OH formation rates range from 16 microM h -1 to 265 microM h -1 . Estimated sunlight steady-state sm-bullet OH concentrations range from 6.7 x 10 -15 to 4.0 x 10 -12 M. Both the formation rates and steady-state concentrations for sm-bullet OH are thus two to three orders of magnitude higher than values reported in the literature for other sunlit surface water samples. Due to the very high rates of formation and steady-state concentrations for sm-bullet OH in these samples, the authors conclude that aqueous-phase reactions involving sm-bullet OH represent a significant pathway by which organic pollutants in illuminated surface waters receiving acidic mine drainage runoff may be consumed

  19. Formation of iron oxides from acid mine drainage and magnetic separation of the heavy metals adsorbed iron oxides

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hee Won; Kim, Jeong Jin; Kim, Young Hun [Andong National University, Andong (Korea, Republic of); Ha, Dong Woo [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

    2016-03-15

    There are a few thousand abandoned metal mines in South Korea. The abandoned mines cause several environmental problems including releasing acid mine drainage (AMD), which contain a very high acidity and heavy metal ions such as Fe, Cu, Cd, Pb, and As. Iron oxides can be formed from the AMD by increasing the solution pH and inducing precipitation. Current study focused on the formation of iron oxide in an AMD and used the oxide for adsorption of heavy metals. The heavy metal adsorbed iron oxide was separated with a superconducting magnet. The duration of iron oxide formation affected on the type of mineral and the degree of magnetization. The removal rate of heavy metal by the adsorption process with the formed iron oxide was highly dependent on the type of iron oxide and the solution pH. A high gradient magnetic separation (HGMS) system successfully separated the iron oxide and harmful heavy metals.

  20. Influence of the Trojan Nickel Mine on surface water quality, Mazowe valley, Zimbabwe: Runoff chemistry and acid generation potential of waste rock

    Science.gov (United States)

    Lupankwa, Keretia; Love, David; Mapani, Benjamin; Mseka, Stephen; Meck, Maideyi

    The impacts of mining on the environment depend on the nature of the ore body, the type of mining and the size of operation. The focus of this study is on Trojan Nickel Mine which is located 90 km north of Harare, Zimbabwe. It produces nickel from iron, iron-nickel and copper-nickel sulphides and disposes of waste rock in a rock dump. Surface water samples were taken at 11 points selected from a stream which drains the rock dump, a stream carrying underground water and the river into which these streams discharge. Samples were analysed for metals using atomic absorption spectrometry, for sulphates by gravitation and for carbonates and bicarbonates by back titration. Ninteen rock samples were collected from the dump and static tests were performed using the Sobek acid base accounting method. The results show that near neutral runoff (pH 7.0-8.5) with high concentrations of sulphate (over 100 mg/L) and some metals (Pb > 1.0 mg/L and Ni > 0.2 mg/L) emanates from the dump. This suggests that acid mine drainage is buffered in the dump (probably by carbonates). This is supported by the static tests, which show that the fine fraction of dump material neutralises acid. Runoff from the dump flows into a pond. Concentrations of sulphates and metals decrease after the dump runoff enters the pond, but sufficient remains to increase levels of calcium, sulphate, bicarbonate, iron and lead in the Pote River. The drop in concentrations at the pond indicates that the settling process has a positive effect on water quality. This could be enhanced by treating the pond water to raise pH, thus precipitating out metals and decreasing their concentrations in water draining from the pond.

  1. THE RESPONSE OF THE PERIPHYTIC DIATOM COMMUNITY TO ACID MINE DRAINAGE POLLUTION

    Directory of Open Access Journals (Sweden)

    Andreea Ciorba

    2004-01-01

    Full Text Available This paper proposes to relate the principal characteristics of diatom community (species richness, biodiversity, community biomass, diatom indices to the stress induced by acidification and high levels of metal. The study was done in a mine drainage affected area in Galicia (NW Spain by comparing periphytic diatom communities from polluted streams to ones in supposedly clean waters. The change in the dominant species was the clearest response to AMD pollution while species richness and diversity were sensitive only to high levels of pollution.

  2. Passive neutralization of acid mine drainage using basic oxygen furnace slag as neutralization material: experimental and modelling.

    Science.gov (United States)

    Zvimba, John N; Siyakatshana, Njabulo; Mathye, Matlhodi

    2017-03-01

    This study investigated passive neutralization of acid mine drainage using basic oxygen furnace slag as neutralization material over 90 days, with monitoring of the parameters' quality and assessment of their removal kinetics. The quality was observed to significantly improve over time with most parameters removed from the influent during the first 10 days. In this regard, removal of acidity, Fe(II), Mn, Co, Ni and Zn was characterized by fast kinetics while removal kinetics for Mg and SO 4 2- were observed to proceed slowly. The fast removal kinetics of acidity was attributed to fast release of alkalinity from slag minerals under mildly acidic conditions of the influent water. The removal of acidity through generation of alkalinity from the passive treatment system was also observed to generally govern the removal of metallic parameters through hydroxide formation, with overall percentage removals of 88-100% achieved. The removal kinetics for SO 4 2- was modelled using two approaches, yielding rate constant values of 1.56 and 1.53 L/(day mol) respectively, thereby confirming authenticity of SO 4 2- removal kinetics experimental data. The study findings provide insights into better understanding of the potential use of slags and their limitations, particularly in mine closure, as part of addressing this challenge in South Africa.

  3. SOLUBILIZATION OF POTASSIUM FROM ALTERNATIVE ROCKS BY HUMIC AND CITRIC ACIDS AND COFFEE HUSK

    Directory of Open Access Journals (Sweden)

    Rodrigo Souza Pessoa

    2015-12-01

    Full Text Available ABSTRACT Brazil imports most of the potassium that it consumes in agriculture, however, such huge external dependence can be minimized with the use of alternative local K bearing rocks. This experiment was conducted with the objective of evaluating the solubility of nepheline syenite and glauconite as a function of three organic matrices, humic acid, citric acid and coffee husk. Incubation of low grade K rocks and organic matrices were done in laboratory conditions, in a completely randomized design. Each rock was mixed with five different doses of each organic matrix and the potassium solubilized was measured periodically, during 180 days. Regardless of the organic matrix and its dose investigated, nepheline syenite samples released more K than the modified glauconite. Soluble K increased as the incubation time increased and its release was greater as the organic matrix dose increased. There was more soluble K when the coffee husk was mixed with the potassic rocks, in relation to the humic and citric acids.

  4. Acidic volcanic rock and its potential as an objective for uranium prospecting

    International Nuclear Information System (INIS)

    Rodriguez Torres, R.; Yza Dominguez, R.; Chavez Aguirre, R.; Constantino, H.E.S.E.

    1976-01-01

    The geographical distribution of recent Mexican volcanic rocks is continuous; the older formations are dispersed in isolated outcrops. Continental volcanic events, acidic and basal, took place in the Caenozoic, Mesozoic and Palaeozoic; basic submarine volcanism predominated in the Mesozoic, Palaeozoic and late Precambrian. Access to the Sierra Madre Occidental, a circum-Pacific mountain range covered by rhyolitic rocks, is limited, which restricts the sections studied. Calderas, sources of volcanic emission and preliminary litho-stratigraphic sections have been delimited on the eastern edge of the range. Subduction by the ocean magmatized the continent from the Permian onwards, extravasating and depositing cyclically various magmata through inverted and normal cortical throws. The Sierra Pena Blanca (Chihuahua) section consists of epiclastic and pyroclastic rocks. A calcareous conglomerate is overburdened by alternate basal tuffs and imbricates, forming five units. In the uraniferous district of the Sierra Pena Blanca the hydrothermal alteration argillitized both components of the ''Nopal'' formation. Primary minerals (pitchblende) are found together with silicification. Leaching favours secondary mineralization (uranium silicates) associated with opals. After extrapolation of the features, the following are considered worth-while objectives: the faces, offsets and prolongations of the Sierra Madre Occidental and the southern volcanic mesetas south of the Mexican Transcontinental Rift. Similar objectives of Mesozoic or Palaeozoic age exist in central and southern Mexico. Possible objectives for uranium are: the acidic volcanic rock of the southern and south-western United States of America, the circum-Pacific acidic volcanic rocks of North America and the acidic volcanic mesetas of Central America and in the Andes. (author)

  5. Stable Carbon Isotope Characterization of CO2 Loss in Acid Mine Drainage Impacted Stream Water: Observations from a Laboratory Experiment

    Science.gov (United States)

    Ali, H. N.; Atekwana, E. A.

    2007-05-01

    Water from an acid mine drainage spring, ground water from a mine tailings pile, stream water and tap water were acidified to simulate acid mine drainage (AMD) contamination. The objective was to determine how acidification of stream water by AMD affected DIC loss and carbon isotope fraction. Two 20 L HDP containers (reactors) containing samples from each source were left un-acidified and allowed to evolve under ambient conditions for several weeks in the laboratory and two others were acidified. Acidification was carried out progressively with sulfuric acid to pH <3. For acidified samples, one reactor was acidified open to the atmosphere and the other closed from contact with atmosphere and CO2(g) was collected under vacuum. The un-acidified samples did not show significant alkalinity and DIC loss, and the 13C of DIC was enriched with time. The acidified samples showed decrease in alkalinity and DIC and increase in the 13C of DIC and CO2(g) with progressive acidification. The enrichment of 13C of DIC for un-acidified samples was due to exchange with atmospheric CO2. On the other hand, the 13C enrichment in the acidified samples was due to fractionation during dehydration of HCO3- and diffusive loss of CO2(g) from the aqueous phase. The actual values measured depended on the amount of CO2 lost from the aqueous phase during acidification. Samples with greater CO2 loss (closed acidification) had greater 13C enrichment. Beyond the HCO3- titration end point, the δ13C of DIC and CO2(g) was similar and nearly constant. The result of this study suggests that AMD effects on DIC can be modeled as a first order kinetic reaction and the isotope enrichment modeled using Rayleigh distillation.

  6. Effects of humic acid on adsorption of actinide elements on rocks and others

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Masakazu; Sato, Seichi; Ohashi, Hiroshi [Hokkaido Univ., Sapporo (Japan). Faculty of Engineering; Sakamoto, Yoshiaki; Nagao, Seiya; Onuki, Toshihiko; Senoo, Muneaki

    1996-01-01

    Since the transfer rates of radionuclides are reduced by their adsorption to rocks and soils, it is essential to elucidate the adsorption process for safety assessment of their geological disposal. In this study, adsorption of Np(V) to goethite, one of the widely distributed minerals was investigated as functions of pH and humic acid concentration. The surface charge density of goethite was determined and the zero charge point was 6.2 for synthesized and 6.4 for natural goethite. Since the point for humic acid was 4.5, adsorption sites for humic acid were reduced as the increase of negative charge density above pH6, resulting in a decrease in its adsorption rate. Np(V) adsorption to goethite was raised by the presence of humic acid in the range of 0-10ppm because the surface charge on the rock was shifted to negative by the adsorption of humic acid, resulting in easy adsorption of NpO{sub 2}{sup +}, which is stable in the condition below pH 9.5. On the other hand, humic acid adsorption was saturated at a concentration higher than 50 ppm, but its content in the solution would increase. Thus, it was thought that Np(V)-humic acid complex becomes more stable, resulting in the decrease in Np(V) adsorption rate. (M.N.)

  7. Benthic Communities of Low-Order Streams Affected by Acid Mine Drainages: A Case Study from Central Europe

    Directory of Open Access Journals (Sweden)

    Marek Svitok

    2014-05-01

    Full Text Available Only little attention has been paid to the impact of acid mine drainages (AMD on aquatic ecosystems in Central Europe. In this study, we investigate the physico-chemical properties of low-order streams and the response of benthic invertebrates to AMD pollution in the Banská Štiavnica mining region (Slovakia. The studied streams showed typical signs of mine drainage pollution: higher conductivity, elevated iron, aluminum, zinc and copper loads and accumulations of ferric precipitates. Electric conductivity correlated strongly with most of the investigated elements (weighted mean absolute correlation = 0.95 and, therefore, can be recommended as a good proxy indicator for rapid AMD pollution assessments. The diversity and composition of invertebrate assemblages was related to water chemistry. Taxa richness decreased significantly along an AMD-intensity gradient. While moderately affected sites supported relatively rich assemblages, the harshest environmental conditions (pH < 2.5 were typical for the presence of a limited number of very tolerant taxa, such as Oligochaeta and some Diptera (Limnophyes, Forcipomyiinae. The trophic guild structure correlated significantly with AMD chemistry, whereby predators completely disappeared under the most severe AMD conditions. We also provide a brief review of the AMD literature and outline the needs for future detailed studies involving functional descriptors of the impact of AMD on aquatic ecosystems.

  8. Biosorption of Fe, Al and Mn of acid drainage from coal mine using brown seaweed sargassum sp. in continuous process

    International Nuclear Information System (INIS)

    Diaz, Andrea; Arias, John; Gelves, Genaro; Maldonado, Alfonso; Laverde, Dionisio; Pedraza, Julio; Escalante, Humberto

    2003-01-01

    The acid mine drainage (AMD) are leaches as result of a coal mining running, it have low ph and high concentrations of heavy metals that convert them in strong polluter; with the purpose of reduce its concentration, a continuous biosorption system was designed by removing heavy metals from drainages using a cheap biosorbent material. The brown seaweed was pre-treatment with solutions 0,1 N of NaOH, Ca(OH) 2 NaCl, CaCl 2 , NaSO 4 y H 2 SO 4 for to study the effect on biosorption process; the removal percentage were determined, which are better than 80% with the exception of pre-treatment with H 2 SO 4 who cancel the algae sorption capacity. The seaweed was packed in plastic mesh and polyester tulle in the shape of a rectangular prism; there isn't effect on the biosorption process by using this packet. The continuous biosorption process was studied in two units of operation: a packed-bed flow-through sorption column and an horizontal vessel like a canal with baffles, which treated adequately 3,5 and 4,71 of AMD respectively, using in each one of them 100 g of algae. The burning of algae was studied like an alternative for the problem of handling of residual algae. The ashes kept the metals removed from AMD, furthermore keep stable too by the attack of solutions of different pH

  9. In situ proteo-metabolomics reveals metabolite secretion by the acid mine drainage bio-indicator, Euglena mutabilis

    Science.gov (United States)

    Halter, David; Goulhen-Chollet, Florence; Gallien, Sébastien; Casiot, Corinne; Hamelin, Jérôme; Gilard, Françoise; Heintz, Dimitri; Schaeffer, Christine; Carapito, Christine; Van Dorsselaer, Alain; Tcherkez, Guillaume; Arsène-Ploetze, Florence; Bertin, Philippe N

    2012-01-01

    Euglena mutabilis is a photosynthetic protist found in acidic aquatic environments such as peat bogs, volcanic lakes and acid mine drainages (AMDs). Through its photosynthetic metabolism, this protist is supposed to have an important role in primary production in such oligotrophic ecosystems. Nevertheless, the exact contribution of E. mutabilis in organic matter synthesis remains unclear and no evidence of metabolite secretion by this protist has been established so far. Here we combined in situ proteo-metabolomic approaches to determine the nature of the metabolites accumulated by this protist or potentially secreted into an AMD. Our results revealed that the secreted metabolites are represented by a large number of amino acids, polyamine compounds, urea and some sugars but no fatty acids, suggesting a selective organic matter contribution in this ecosystem. Such a production may have a crucial impact on the bacterial community present on the study site, as it has been suggested previously that prokaryotes transport and recycle in situ most of the metabolites secreted by E. mutabilis. Consequently, this protist may have an indirect but important role in AMD ecosystems but also in other ecological niches often described as nitrogen-limited. PMID:22237547

  10. Porous reactive wall for prevention of acid mine drainage: Results of a full-scale field demonstration

    International Nuclear Information System (INIS)

    Benner, S.G.; Blowes, D.W.; Ptacek, C.J.

    1997-01-01

    A porous reactive wall was installed in August, 1995, to treat mine drainage flowing within an aquifer at the Nickel Rim mine site, near Sudbury, Ontario. The reactive mixture was designed to maximize removal of metals and acid generating capacity from the groundwater by enhancing sulfate reduction and metal sulfide precipitation. The installed structure, composed of a mixed organic substrate, is 15 meters long, 3.6 meters deep and the flow path length (wall width) is 4 meters. Results of sampling nine months after installation, indicate that sulfate reduction and metal sulfide precipitation is occurring. Comparing the chemistry of water entering the wall to treated water exiting the wall nine months after installation: SO 4 concentrations decrease by >50% (from 2400-4800 mg/L to 60-3600 mg/L), Fe concentrations decrease by >95% (from 260-1300 mg/L to 1.0-40 mg/L), pH increased from 5.8 to 7.0 and alkalinity increased from 0-60 mg/L to 700-3200 mg/L as CaCO 3 . After passing through the reactive wall, the net acid generating potential of the aquifer water was converted from acid producing to acid consuming

  11. Impact of Acid Attack on the Shear Behaviour of a Carbonate Rock Joint

    Science.gov (United States)

    Nouailletas, O.; Perlot, C.; Rivard, P.; Ballivy, G.; La Borderie, C.

    2017-06-01

    The mechanical behaviour of structural discontinuities in rock mass is a key element of the stability analysis in civil engineering, petroleum engineering and mining engineering. In this paper, the mechanical analysis is coupled with the acidic attack of a rock joint associated with leakage of CO2 through a geological fault in the context of carbon sequestration. Experiments were conducted at the laboratory scale to assess the shear behaviour of degraded joint: direct shear tests were performed on rock joints that have been previously immersed into water or into an acidic solution (pH 0.2). The shear behaviour of joints is governed by the roughness of its walls: the parameters Z2, Z3, Z4 and RL characterize the rough surfaces. They are calculated from the scans of joint surfaces after and before immersion. Their comparison pointed out a slight impact of the acidic attack. However, the results of the direct shear tests show significant modifications in the shear behaviour for the degraded joints: the tangential stress peak disappears, the tangential stiffness decreases in the stress/displacement curve, and the contraction increases, the dilation angle decreases in the dilation curve. Acid attack has a greater impact on the mechanical properties of the asperities than their geometric characteristics. The results of this study will be used to improve chemo-mechanical modelling to better simulate with higher accuracy the fault stability in different cases of civil engineering, petroleum engineering and mining engineering.

  12. BIOREMEDIATION FOR ACID MINE DRAINAGE: ORGANIC SOLID WASTE AS CARBON SOURCES FOR SULFATE-REDUCING BACTERIA: A REVIEW

    Directory of Open Access Journals (Sweden)

    I. N. Jamil

    2013-12-01

    Full Text Available Biological sulfate reduction has been slowly replacing chemical unit processes to treat acid mine drainage (AMD. Bioremediations for AMD treatment are favored due to their low capital and maintenance cost. This paper describes the available AMD treatment, current SRB commercialization such as THIOPAQ® and BioSulphide® technologies, and also the factors and limitations faced. THIOPAQ® and BioSulphide® technologies use expensive carbon sources such as hydrogen as the electron donor. This paper discusses the possibility of organic solid waste as an alternative substrate as it is cheaper and abundant. A possible AMD treatment system setup was also proposed to test the efficiency of sulfate-reducing bacteria utilizing organic solid substrate.

  13. Thermodynamic data for modeling acid mine drainage problems: compilation and estimation of data for selected soluble iron-sulfate minerals

    Science.gov (United States)

    Hemingway, Bruch S.; Seal, Robert R.; 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.

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

    Science.gov (United States)

    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%.

  15. IMPACT OF ADDITIONALS CONTAMINANTS DUE TO ACID MINE DRAINAGE IN TRIBUTARIES OF THE PILCOMAYO RIVER FROM CERRO RICO, POTOSÍ, BOLIVIA

    Directory of Open Access Journals (Sweden)

    William H.J. Strosnider

    2014-09-01

    Full Text Available Intensive mining and processing of the polymetallic sulfide ore body of Cerro Rico de Potosí (Bolivia has occurred since 1545. To further investigate acid mine drainage (AMD discharges and their link to downstream contamination, data were gathered during two sampling events during the most extreme periods of the dry and wet seasons of one year. Concentrations of Ag, B, Ba, Mo, Sb, Se, Sn and V in AMD and receiving streams were greater than Bolivian discharge limits and receiving water body guidelines as well as international agricultural use standards. High concentrations of rare earth metals have been documented in this area. Results indicate that contamination from mining has a larger scope than previously thought and underscore the importance of remediation.

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

    Science.gov (United States)

    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 treatment costs while at the same time ameliorating the impacts of P contamination.

  17. Bio-Remediation of Acid Mine Drainage in the Sarcheshmeh Porphyry Copper Mine by Fungi: Batch and Fixed Bed Process

    Directory of Open Access Journals (Sweden)

    Hanieh Soleimanifar

    2012-12-01

    Full Text Available Acid mine drainage (AMD containing high concentrations of iron and sulphate, low pH and variableconcentrations of heavy metals leads to many environmental problems. The concentrations of Cu and Mnare high in the AMD of the Sarcheshmeh porphyry copper mine, Kerman province, south of Iran. In thisstudy, the bio-remediation of Cu and Mn ions from acid mine drainage was investigated using two nativefungi called Aspergillus niger and Phanerochaete chrysosporium which were extracted from the soil andsediment samples of the Shour River at the Sarcheshmeh mine. The live fungi was first harvested andthen killed by boiling in 0.5 N NaOH solution. The biomass was finally dried at 60 C for 24 h andpowdered. The optimum biosorption parameters including pH, temperature, the amount of biosorbent andcontact time were determined in a batch system. The optimum pH varied between 5 and 6. It was foundthat the biosorption process increased with an increase in temperature and the amount of biosorbent.Biosorption data were attempted by Langmuir and Freundlich isotherm models and showed a good match.Kinetic studies were also carried out in the present study. The results show that the second-order kineticsmodel fits well the experimental data. The biosorption experiments were further investigated with acontinuous system to compare the biosorption capacities of two systems. The results show thatbiosorption process using a continuous system increases efficiency up to 99%. A desorption process waseventually performed in order to recover Copper and Manganese ions. This process was successful andfungi could be used again.

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

    Science.gov (United States)

    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.

  19. Complete removal of arsenic and zinc from a heavily contaminated acid mine drainage via an indigenous SRB consortium

    Energy Technology Data Exchange (ETDEWEB)

    Le Pape, Pierre, E-mail: pierrelp.hm@gmail.com [Sorbonne Universités – Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR IRD 206, UPMC Université Paris VI, 4 place Jussieu, 75252 Paris cedex 05 (France); Battaglia-Brunet, Fabienne; Parmentier, Marc; Joulian, Catherine; Gassaud, Cindy [French Geological Survey (BRGM), 3 av. Claude Guillemin, 45060, BP 36009, Orléans Cedex 2 (France); Fernandez-Rojo, Lidia [HydroSciences Montpellier, UMR 5569 CNRS-IRD-UM, CC57, 163 rue Auguste Broussonet, 34090 Montpellier (France); Guigner, Jean-Michel; Ikogou, Maya; Stetten, Lucie [Sorbonne Universités – Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR IRD 206, UPMC Université Paris VI, 4 place Jussieu, 75252 Paris cedex 05 (France); Olivi, Luca [Sincrotrone Trieste ELETTRA, I-34012 Trieste (Italy); Casiot, Corinne [HydroSciences Montpellier, UMR 5569 CNRS-IRD-UM, CC57, 163 rue Auguste Broussonet, 34090 Montpellier (France); Morin, Guillaume [Sorbonne Universités – Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR IRD 206, UPMC Université Paris VI, 4 place Jussieu, 75252 Paris cedex 05 (France)

    2017-01-05

    Highlights: • SRB activity is evidenced at acidic pH in acid mine drainage water. • Total arsenic and zinc removal from solution is observed. • As, Zn and Fe are observed to precipitate as biogenic sulfides. • Amorphous orpiment (As{sup III}{sub 2}S{sub 3}) and realgar (As{sup II}S) are observed as main As-bearing sulfides. • A mechanism is proposed for the reduction of As{sub 2}S{sub 3} to AsS by biogenic H{sub 2}S under acidic conditions. - Abstract: Acid mine drainages (AMD) are major sources of pollution to the environment. Passive bio-remediation technologies involving sulfate-reducing bacteria (SRB) are promising for treating arsenic contaminated waters. However, mechanisms of biogenic As-sulfide formation need to be better understood to decontaminate AMDs in acidic conditions. Here, we show that a high-As AMD effluent can be decontaminated by an indigenous SRB consortium. AMD water from the Carnoulès mine (Gard, France) was incubated with the consortium under anoxic conditions and As, Zn and Fe concentrations, pH and microbial activity were monitored during 94 days. Precipitated solids were analyzed using electron microscopy (SEM/TEM-EDXS), and Extended X-Ray Absorption Fine Structure (EXAFS) spectroscopy at the As K-edge. Total removal of arsenic and zinc from solution (1.06 and 0.23 mmol/L, respectively) was observed in two of the triplicates. While Zn precipitated as ZnS nanoparticles, As precipitated as amorphous orpiment (am-As{sup III}{sub 2}S{sub 3}) (33–73%), and realgar (As{sup II}S) (0–34%), the latter phase exhibiting a particular nanowire morphology. A minor fraction of As is also found as thiol-bound As{sup III} (14–23%). We propose that the formation of the As{sup II}S nanowires results from As{sup III}{sub 2}S{sub 3} reduction by biogenic H{sub 2}S, enhancing the efficiency of As removal. The present description of As immobilization may help to set the basis for bioremediation strategies using SRB.

  20. Hydrochemistry, mineralogy and sulfur isotope geochemistry of acid mine drainage at the Mt. Morgan mine environment, Queensland, Australia

    International Nuclear Information System (INIS)

    Edraki, M.; Golding, S.D.; Baublys, K.A.; Lawrence, M.G.

    2005-01-01

    Mineralogical, hydrochemical and S isotope data were used to constrain hydrogeochemical processes that produce acid mine drainage from sulfidic waste at the historic Mount Morgan Au-Cu mine, and the factors controlling the concentration of SO 4 and environmentally hazardous metals in the nearby Dee River in Queensland, Australia. Some highly contaminated acid waters, with metal contents up to hundreds of orders of magnitude greater than the Australia-New Zealand environmental standards, by-pass the water management system at the site and drain into the adjacent Dee River. Mine drainage precipitates at Mt. Morgan were classified into 4 major groups and were identified as hydrous sulfates and hydroxides of Fe and Al with various contents of other metals. These minerals contain adsorbed or mineralogically bound metals that are released into the water system after rainfall events. Sulfate in open pit water and collection sumps generally has a narrow range of S isotope compositions (δ 34 S = 1.8-3.7%o) that is comparable to the orebody sulfides and makes S isotopes useful for tracing SO 4 back to its source. The higher δ 34 S values for No. 2 Mill Diesel sump may be attributed to a difference in the source. Dissolved SO 4 in the river above the mine influence and 20 km downstream show distinctive heavier isotope compositions (δ 34 S = 5.4-6.8%o). The Dee River downstream of the mine is enriched in 34 S (δ 34 S = 2.8-5.4%o) compared with mine drainage possibly as a result of bacterial SO 4 reduction in the weir pools, and in the water bodies within the river channel. The SO 4 and metals attenuate downstream by a combination of dilution with the receiving waters, SO 4 reduction, and the precipitation of Fe and Al sulfates and hydroxides. It is suggested here that in subtropical Queensland, with distinct wet and dry seasons, temporary reducing environments in the river play an important role in S isotope systematics

  1. Isolation and identification of a Candida digboiensis strain from an extreme acid mine drainage of the Lignite Mine, Gujarat.

    Science.gov (United States)

    Patel, Mitesh J; Tipre, Devayani R; Dave, Shailesh R

    2009-12-01

    An extremely acidic mine drainage (AMD) water sample was collected in 1998 and 2008 from Panandhro lignite mine, Gujarat, India. The yeast isolated from this sample was identified using mini API identification system, as a member of genus Candida. The major cellular fatty acids detected by FAME from the isolate are C(16:0) and C(18:2) (cis 9,12)/C(18:0alpha) as 25.23 and 19.5%, respectively. The isolate was identified as Candida digboiensis by 18S rRNA gene sequence analysis and designated as Candida digboiensis SRDyeast1. Phylogenetic analysis using D1/D2 variable domains showed that the closest relative of this strain is Candida blankii with 3% divergence. This organism has been reported for the first time from the lignite mine AMD sample, and for cellular fatty acid analysis. This yeast is able to survive in the AMD sample preserved at 10-42 degrees C temperature since last 10 years along with iron oxidizing microorganisms. It can grow in the presence of 40% glucose, 10% NaCl and in the pH range of 1 to 10. The isolate is capable of producing enzymes like protease and lipase. This isolate differs from the type strain Candida digboiensis in as many as six physiological and metabolic characteristics.

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

    Science.gov (United States)

    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).

  3. Single-cell sequencing unveils the lifestyle and CRISPR-based population history of Hydrotalea sp. in acid mine drainage.

    Science.gov (United States)

    Medeiros, J D; Leite, L R; Pylro, V S; Oliveira, F S; Almeida, V M; Fernandes, G R; Salim, A C M; Araújo, F M G; Volpini, A C; Oliveira, G; Cuadros-Orellana, S

    2017-10-01

    Acid mine drainage (AMD) is characterized by an acid and metal-rich run-off that originates from mining systems. Despite having been studied for many decades, much remains unknown about the microbial community dynamics in AMD sites, especially during their early development, when the acidity is moderate. Here, we describe draft genome assemblies from single cells retrieved from an early-stage AMD sample. These cells belong to the genus Hydrotalea and are closely related to Hydrotalea flava. The phylogeny and average nucleotide identity analysis suggest that all single amplified genomes (SAGs) form two clades that may represent different strains. These cells have the genomic potential for denitrification, copper and other metal resistance. Two coexisting CRISPR-Cas loci were recovered across SAGs, and we observed heterogeneity in the population with regard to the spacer sequences, together with the loss of trailer-end spacers. Our results suggest that the genomes of Hydrotalea sp. strains studied here are adjusting to a quickly changing selective pressure at the microhabitat scale, and an important form of this selective pressure is infection by foreign DNA. © 2017 John Wiley & Sons Ltd.

  4. Acid mine drainage in the Iberian Pyrite Belt: 1. Hydrochemical characteristics and pollutant load of the Tinto and Odiel rivers.

    Science.gov (United States)

    Nieto, Jose M; Sarmiento, Aguasanta M; Canovas, Carlos R; Olias, Manuel; Ayora, Carlos

    2013-11-01

    Acid mine drainage in the Iberian Pyrite Belt is probably the worst case in the world of surface water pollution associated with mining of sulphide mineral deposits. The Iberian Pyrite Belt is located in SW Iberian Peninsula, and it has been mined during the last 4,500 years. The central and eastern part of the Iberian Pyrite Belt is drained by the Tinto and Odiel rivers, which receive most of the acidic leachates from the mining areas. As a result, the main channels of the Tinto and Odiel rivers are very rich in metals and highly acidic until reaching the Atlantic Ocean. A significant amount of the pollutant load transported by these two rivers is delivered during the rainy season, as is usual in rivers of Mediterranean climate regions. Therefore, in order to have an accurate estimation of the pollutant loads transported by the Tinto and Odiel rivers, a systematic sampling on a weekly basis and a high temporal resolution sampling of floods events were both performed. Results obtained show that metal fluxes are strongly dependent on the study period, highlighting the importance of inter-annual studies involving dry and wet years.

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

    Science.gov (United States)

    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.

  6. Microbial communities associated with uranium in-situ recovery mining process are related to acid mine drainage assemblages.

    Science.gov (United States)

    Coral, Thomas; Descostes, Michaël; De Boissezon, Hélène; Bernier-Latmani, Rizlan; de Alencastro, Luiz Felippe; Rossi, Pierre

    2018-07-01

    A large fraction (47%) of the world's uranium is mined by a technique called "In Situ Recovery" (ISR). This mining technique involves the injection of a leaching fluid (acidic or alkaline) into a uranium-bearing aquifer and the pumping of the resulting solution through cation exchange columns for the recovery of dissolved uranium. The present study reports the in-depth alterations brought to autochthonous microbial communities during acidic ISR activities. Water samples were collected from a uranium roll-front deposit that is part of an ISR mine in operation (Tortkuduk, Kazakhstan). Water samples were obtained at a depth of ca 500 m below ground level from several zones of the Uyuk aquifer following the natural redox zonation inherited from the roll front deposit, including the native mineralized orebody and both upstream and downstream adjacent locations. Samples were collected equally from both the entrance and the exit of the uranium concentration plant. Next-generation sequencing data showed that the redox gradient shaped the community structures, within the anaerobic, reduced, and oligotrophic habitats of the native aquifer zones. Acid injection induced drastic changes in the structures of these communities, with a large decrease in both cell numbers and diversity. Communities present in the acidified (pH values acid mine drainage, with the dominance of Sulfobacillus sp., Leptospirillum sp. and Acidithiobacillus sp., as well as the archaean Ferroplasma sp. Communities located up- and downstream of the mineralized zone under ISR and affected by acidic fluids were blended with additional facultative anaerobic and acidophilic microorganisms. These mixed biomes may be suitable communities for the natural attenuation of ISR mining-affected subsurface through the reduction of metals and sulfate. Assessing the effect of acidification on the microbial community is critical to evaluating the potential for natural attenuation or active bioremediation strategies

  7. Aluminium (Al) fractionation and speciation: getting closer to describing the factors influencing Al(sup3+) in water impacted by acid mine drainage

    CSIR Research Space (South Africa)

    Chamier, J

    2015-07-01

    Full Text Available 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...

  8. Integrated treatment of acid mine drainage using BOF slag, lime/soda ash and reverse osmosis (RO): Implication for the production of drinking water

    CSIR Research Space (South Africa)

    Masindi, Vhahangwele

    2017-12-01

    Full Text Available -up with environmental friendly and zeroliquid-discharge technologies. The purpose of this novel study was to produce drinking water and recover valuable minerals from acid mine drainage using an integration of Basic Oxygen Furnace (BOF) slag, lime, soda ash and Reverse...

  9. Acid mine drainage arising from gold mining activity in Johannesburg, South Africa and environs

    International Nuclear Information System (INIS)

    Naicker, K.; Cukrowska, E.; McCarthy, T.S.

    2003-01-01

    Ground water within the mining district is heavily contaminated and acidified. - The Witwatersrand region of South Africa is famous for its gold production and a major conurbation, centred on Johannesburg, has developed as a result of mining activity. A study was undertaken of surface and ground water in a drainage system in this area. Soils were also analysed from a site within the mining district. This study revealed that the ground water within the mining district is heavily contaminated and acidified as a result of oxidation of pyrite (FeS 2 ) contained within mine tailings dumps, and has elevated concentrations of heavy metals. Where the water table is close to surface, the upper 20 cm of soil profiles are severely contaminated by heavy metals due to capillary rise and evaporation of the ground water. The polluted ground water is discharging into streams in the area and contributes up to 20% of stream discharge, causing a lowering of pH of the stream water. Much of the metal load is precipitated in the stream: Fe and Mn precipitate as a consequence of oxidation, while other heavy metals are being removed by co-precipitation. The oxidation of iron has created a redox buffer which controls the pH of the stream water. The rate of oxidation and of dilution is slow and the deleterious effect of the addition of contaminated water persists for more than 10 km beyond the source

  10. Spatial and Temporal Analysis of the Microbial Community in the Tailings of a Pb-Zn Mine Generating Acidic Drainage ▿ †

    Science.gov (United States)

    Huang, Li-Nan; Zhou, Wen-Hua; Hallberg, Kevin B.; Wan, Cai-Yun; Li, Jie; Shu, Wen-Sheng

    2011-01-01

    Analysis of spatial and temporal variations in the microbial community in the abandoned tailings impoundment of a Pb-Zn mine revealed distinct microbial populations associated with the different oxidation stages of the tailings. Although Acidithiobacillus ferrooxidans and Leptospirillum spp. were consistently present in the acidic tailings, acidophilic archaea, mostly Ferroplasma acidiphilum, were predominant in the oxidized zones and the oxidation front, indicating their importance to generation of acid mine drainage. PMID:21705549

  11. Measured and simulated effects of sophisticated drainage techniques on groundwater level and runoff hydrochemistry in areas of boreal acid sulphate soils

    Directory of Open Access Journals (Sweden)

    I. BÄRLUND

    2008-12-01

    Full Text Available To abate the environmental problems caused by the severe acidity and high metal concentrations in rivers draining acid sulphate (AS soils of Western Finland, control drainage (CD and lime filter drainage (LFD, and their combination, were investigated. The effectiveness of these best management practices (BMP’s on drainage water quality was studied on plot scale in two locations. In Ilmajoki, where the sulphidic materials are more than 2 m below the soil surface, CD efficiently reduced the concentrations of sulphate, aluminium, manganese and iron concentrations and to some extent also increased the pH of the drainage waters. LFD, in contrast, effectively reduced the drainage water acidity and raised the pH level. Decrease of the groundwater level owing to strong evapotranspiration in summer could, however, not be properly prevented by CD. In Mustasaari where sulphidic materials were as shallow as 1 m below soil surface, the positive effects of LFD recognised in Ilmajoki were hardly seen. This shows, that the tested BMP’s work properly, and can thus be recommended, for intensively artificially drained AS soils like in Ilmajoki where most of the acidity has already been transported to watercourses. LFD can, however, not be recommended for as yet poorly leached and thus particularly problematic AS soils like in Mustasaari. This is, of course, a drawback of the tested BMP, as it is not effective for the soils which would need it most. The field data were tentatively utilised to test the performance of the HAPSU (Ionic Flow Model for Acid Sulphate Soils simulation model developed to estimate the loads of harmful substances from AS soils.;

  12. The development of bio-carbon adsorbents from Lodgepole Pine to remediate acid mine drainage in the Rocky Mountains

    International Nuclear Information System (INIS)

    Shin, Eun-Jae; Lauve, Alexander; Carey, Maxwell; Bukovsky, Eric; Ranville, James F.; Evans, Robert J.; Herring, Andrew M.

    2008-01-01

    Activated carbon adsorbents were produced from biomass locally available in the Rocky Mountain West, e.g. Lodgepole Pine (Pinus contorta), by vacuum pyrolysis at moderate temperatures followed by steam activation, for use as metal adsorbents for acid mine drainage (AMD). Wood cubes from fresh cut Lodgepole Pine (P. contorta) with different sizes, 3 and 12 mm, were made. Sawdust was also used to study the effect of sample size as well as sample material. We applied chemical pretreatment with potassium hydroxide before charring to improve the quality of the activated carbons. We compared the characteristics of the activated carbons, which were chemically pretreated, before and after washing with water. After washing, the BET surface area was found to increase and diffuse reflectance infrared spectroscopy showed changes in the carbon matrix. We then tested the samples for metal adsorption from AMD sampled from AMD sites in Colorado, Clear Creek County and the Leadville mine drainage tunnel, along with a commercial activated carbon for comparison. We used a batch method to measure maximum metal adsorption of the activated carbons. The metals chosen to be monitored were copper, cadmium, manganese, nickel, lead, and zinc, because they are the principal metals of interest for the test areas, and metal concentrations were determined by ion coupled plasma-atomic emission spectroscopy. The samples produced in this work outperformed the commercial activated carbon in two AMD water treatment tests and for the six metals monitored. This metal adsorption data indicate that locally produced inexpensive activated carbons can be used as adsorbents for AMD successfully

  13. The development of bio-carbon adsorbents from Lodgepole Pine to remediate acid mine drainage in the Rocky Mountains

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Eun-Jae [Department of Chemical Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401 (United States)], E-mail: eshin@mines.edu; Lauve, Alexander; Carey, Maxwell [Department of Chemical Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401 (United States); Bukovsky, Eric; Ranville, James F. [Department of Chemistry and Geochemistry, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401 (United States); Evans, Robert J.; Herring, Andrew M. [Department of Chemical Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401 (United States)

    2008-03-15

    Activated carbon adsorbents were produced from biomass locally available in the Rocky Mountain West, e.g. Lodgepole Pine (Pinus contorta), by vacuum pyrolysis at moderate temperatures followed by steam activation, for use as metal adsorbents for acid mine drainage (AMD). Wood cubes from fresh cut Lodgepole Pine (P. contorta) with different sizes, 3 and 12 mm, were made. Sawdust was also used to study the effect of sample size as well as sample material. We applied chemical pretreatment with potassium hydroxide before charring to improve the quality of the activated carbons. We compared the characteristics of the activated carbons, which were chemically pretreated, before and after washing with water. After washing, the BET surface area was found to increase and diffuse reflectance infrared spectroscopy showed changes in the carbon matrix. We then tested the samples for metal adsorption from AMD sampled from AMD sites in Colorado, Clear Creek County and the Leadville mine drainage tunnel, along with a commercial activated carbon for comparison. We used a batch method to measure maximum metal adsorption of the activated carbons. The metals chosen to be monitored were copper, cadmium, manganese, nickel, lead, and zinc, because they are the principal metals of interest for the test areas, and metal concentrations were determined by ion coupled plasma-atomic emission spectroscopy. The samples produced in this work outperformed the commercial activated carbon in two AMD water treatment tests and for the six metals monitored. This metal adsorption data indicate that locally produced inexpensive activated carbons can be used as adsorbents for AMD successfully.

  14. Distribution, ecology and inhibition of Thiobacillus ferrooxidans in relation to acid drainage from Witwatersrand gold mine dumps

    International Nuclear Information System (INIS)

    Whillier, P.A.

    1987-03-01

    The distribution and ecology of Thiobacillus ferrooxidans in gold mine dumps and possible means for its inhibition were investigated. A literature survey of the micro-ecology of mine waste dumps in various parts of the world was undertaken. A linear alkylbenzene sulphonate (LAS), NANSA 80/S, and a cetyl pyridinium chloride, Ceepryn, were tested as possible inhibitors for mine dump application. The LAS was rejected because it is poorly soluble in water and required higher concentrations than SLS for the inhibition of T.ferrooxidans. Ceepryn was an efficient inhibitor, but its efficiency was dramatically impeded in the presence of mine dump sand making it unsuitable for application on dumps. The SLS and LAS were tested against a mixed population of T.ferrooxidans from gold mine dumps and these bacteria were shown to be marginally more resistant to the inhibitors than the pure T.ferrooxidans culture. Sampling from mine dumps on the Witwatersrand suggested that the major T.ferrooxidans populations occurred in the moist sand of the drainage areas at the base of dumps, with few viable iron-oxidising bacteria located on the surfaces or in the centre of dumps. Sites of low moisture in dumps contained few or no viable bacteria. In the laboratory the bacterial viability decreased rapidly with loss of moisture from the sand. Moisture was shown to be important to bacterial activity and should be considered with respect to acid drainage control. Experimental sand columns showed that iron was leached with water from mine dump sand in the absence and presence of bacteria. In this study substrates, moisture, oxygen and carbon dioxide availability, ph, temperature, microorganisms and metal pollutants of uranium waste dumps are also covered

  15. Plan for injection of coal combustion byproducts into the Omega Mine for the reduction of acid mine drainage

    International Nuclear Information System (INIS)

    Gray, T.A.; Moran, T.C.; Broschart, D.W.; Smith, G.A.

    1998-01-01

    The Omega Mine Complex is located outside of Morgantown, West Virginia. The mine is in the Upper Freeport Coal, an acid-producing coal seam. The coal was mined in a manner that has resulted in acid mine drainage (AMD) discharges at multiple points. During the 1990's, the West Virginia Division of Environmental Protection (WVDEP) assumed responsibility for operating a collection and treatment system for the AMD. Collection and treatment costs are approximately $300,000 per year. Injecting grout into the mine workings to reduce AMD (and thus reducing treatment costs) is proposed. The procedure involves injecting grout mixes composed primarily of coal combustion byproducts (CCB's) and water, with a small quantity of cement. The intention of the injection program is to fill the mine voids in the north lobe of the Omega Mine (an area where most of the acidity is believed to be generated) with the grout, thus reducing the contact of air and water with potentially acidic material. The grout mix design consists of an approximate 1:1 ratio of fly ash to byproducts from fluidized bed combustion. Approximately 100 gallons of water per cubic yard of grout is used to achieve flowability. Observation of the mine workings via subsurface borings and downhole video camera confirmed that first-mined areas were generally open while second-mined areas were generally partially collapsed. The injection program was developed to account for this by utilizing closer injection hole spacing in second-mined areas. Construction began in January 1998, with grout injection expected to commence in mid-April 1998

  16. Rho Kinase ROCK2 Mediates Acid-Induced NADPH Oxidase NOX5-S Expression in Human Esophageal Adenocarcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Jie Hong

    Full Text Available Mechanisms of the progression from Barrett's esophagus (BE to esophageal adenocarcinoma (EA are not fully understood. We have shown that NOX5-S may be involved in this progression. However, how acid upregulates NOX5-S is not well known. We found that acid-induced increase in NOX5-S expression was significantly decreased by the Rho kinase (ROCK inhibitor Y27632 in BE mucosal biopsies and FLO-1 EA cells. In addition, acid treatment significantly increased the Rho kinase activity in FLO-1 cells. The acid-induced increase in NOX5-S expression and H2O2 production was significantly decreased by knockdown of Rho kinase ROCK2, but not by knockdown of ROCK1. Conversely, the overexpression of the constitutively active ROCK2, but not the constitutively active ROCK1, significantly enhanced the NOX5-S expression and H2O2 production. Moreover, the acid-induced increase in Rho kinase activity and in NOX5-S mRNA expression was blocked by the removal of calcium in both FLO-1 and OE33 cells. The calcium ionophore A23187 significantly increased the Rho kinase activity and NOX5-S mRNA expression. We conclude that acid-induced increase in NOX5-S expression and H2O2 production may depend on the activation of ROCK2, but not ROCK1, in EA cells. The acid-induced activation of Rho kinase may be mediated by the intracellular calcium increase. It is possible that persistent acid reflux present in BE patients may increase the intracellular calcium, activate ROCK2 and thereby upregulate NOX5-S. High levels of reactive oxygen species derived from NOX5-S may cause DNA damage and thereby contribute to the progression from BE to EA.

  17. Thallium release from acid mine drainages: Speciation in river and tap water from Valdicastello mining district (northwest Tuscany).

    Science.gov (United States)

    Campanella, Beatrice; Casiot, Corinne; Onor, Massimo; Perotti, Martina; Petrini, Riccardo; Bramanti, Emilia

    2017-08-15

    In this work we present an advantageous method for the simultaneous separation and detection of Tl(I) and Tl(III) species through ion chromatography coupled with on-line inductively coupled plasma - mass spectrometry. Chromatographic separation between Tl(III) and Tl(I) was achieved in less than two minutes. The method was validated by recovery experiments on real samples, and by comparing the sum of the concentrations of individual Tl species with total thallium values obtained from continuous flow ICP-MS. The experimental procedure offers an accurate, sensitive and interference-free method for Tl speciation at trace levels in environmental samples. This allowed us to investigate the Tl speciation in acid mine drainages (AMD), surface waters and springs in a mining catchment in Valdicastello Carducci (Tuscany, Italy), where severe Tl contamination ad been evidenced previously. This study shows for the first time that Tl(III), in addition to Tl(I), is present in considerable amounts in water samples affected by acid mining outflow, raising the question of the origin of this thermodynamically unstable species. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    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.

  19. Impact of acid mine drainage from mining exploitations on the Margajita River basin and the Hatillo reservoir (Dominican Republic)

    International Nuclear Information System (INIS)

    Grandia, F.; Salas, J.; Arcos, D.; Archambault, A.; Cottard, F.

    2009-01-01

    Mining of the Pueblo Viejo high-sulphidation epithermal deposit (Dominican Republic) leads to environmental impact due to the formation of acid mine drainage associated with the oxidative dissolution of sulphides and sulpho salts. In addition to the very low pH, the acid waters are capable of transporting away from the mining areas high concentrations of metals and metalloids in solution. In the present work, a geochemical study of sediments deposited in the Hatillo reservoir is carried out. This reservoir is fed by the Margajita and Yuna streams which transport leachates from the Pueblo Viejo and Falcondo-Bonao (Cr-Ni) mining areas, respectively. The results show that these sediments have very high concentrations of Fe, Al and sulphate, along with significant amounts of As, Zn and Te, which are of especial environmental concern. The main contributor to this metal discharge into the reservoir is the Margajita stream, whereas the Yuna stream does not transport significant amounts of metals in solution due to its neutral pH, although it is likely that metals such as Mn, Cr, Ni and Co can be mobilised as a particulate. (Author) 5 refs.

  20. Neutralization of acid mine drainage using the final product from CO2 emissions capture with alkaline paper mill waste

    International Nuclear Information System (INIS)

    Perez-Lopez, Rafael; Castillo, Julio; Quispe, Dino; Nieto, Jose Miguel

    2010-01-01

    In this study, experiments were conducted to investigate the applicability of low-cost alkaline paper mill wastes as acidity neutralizing agents for treatment of acid mine drainage (AMD). Paper wastes include a calcium mud by-product from kraft pulping, and a calcite powder from a previous study focused on sequestering CO 2 by carbonation of calcium mud. The neutralization process consisted of increase of pH by alkaline additive dissolution, decrease of metals solubility and precipitation of gypsum and poorly crystallized Fe-Al oxy-hydroxides/oxy-hydroxysulphates, which acted as a sink for trace elements to that extent that solutions reached the pre-potability requirements of water for human consumption. This improvement was supported by geochemical modelling of solutions using PHREEQC software, and observations by scanning electron microscope and X-ray diffraction of reaction products. According to PHREEQC simulations, the annual amount of alkaline additive is able to treat AMD (pH 3.63, sulphate 3800 mg L -1 , iron 348 mg L -1 ) with an average discharge of about 114 and 40 L s -1 for calcium mud and calcite powder, respectively. Likewise, given the high potential of calcium mud to sequester CO 2 and of resulting calcite powder to neutralize AMD, paper wastes could be a promising solution for facing this double environmental problem.

  1. An overview of the western Maryland coal combustion by-products/acid mine drainage initiative, Part 1 of 3

    International Nuclear Information System (INIS)

    Petzrick, P.; Rafalko, L.G.; Lyons, C.

    1996-01-01

    The western Maryland coal combustion by-products (CCB)/acid mine drainage (AMD) initiative (the Initiative) is a public-private partnership exploring the use of CCBs to eliminate AMD from Maryland's abandoned coal mines. This dynamic partnership will sponsor a series of large scale experiments and demonstrations addressing the engineering problems that characterize the beneficial application of CCBs to prevent acid formation on a scale that is consistent with the large quantity of these materials that will be produced by power plants in or near western Maryland. The initial demonstration is the filling and sealing of a small hand dug mine (the Frazee Mine) under approximately ninety feet of overburden on Winding Ridge near Friendsville, Maryland. A second demonstration is being planned for the Kempton mine complex. Subsequent demonstrations will focus on reducing the cost of materials handling and mine injection and solving the engineering problems characteristic of filling abandoned mines in Maryland. The Initiative is the flagship activity in Maryland's overall Ash Utilization Program, the goal of which is to promote beneficial use of all coal combustion by-products

  2. ANALYSIS OF MUNICIPAL WASTEWATER AND ACID MINE DRAINAGE PASSIVE CO-TREATMENT AT CERRO RICO DE POTOSÍ, BOLIVIA

    Directory of Open Access Journals (Sweden)

    William H.J. Strosnider

    2015-06-01

    Full Text Available Acid mine drainage (AMD is a worldwide environmental problem. The passive co-treatment of AMD with municipal waste water (MWW is a cost effective approach that uses nutrients in MWW in order to treat high concentrations of metals and sulfate found in AMD. Cerro Rico de Potosí in Bolivia is one of the biggest mining cities in the world, and it is constantly facing problems with AMD. The goal of this study was to determine the reaction rates of Al, Fe, Mn, Zn, and other metals found in an AMD discharge from Cerro Rico by a three-stage reactor system. The AMD had a pH of 3.58 and acidity of 1080 mg/L as CaCO3 equivalent containing 12, 68, 17 and 550 mg/L of dissolved Al, Fe, Mn, and Zn respectively. The reaction rates of Al, Fe, Mn, and Zn were 1.43, 2.09, 0.01, and 0.10 d-1, respectively.

  3. Fluidized bed ash and passive treatment reduce the adverse effects of acid mine drainage on aquatic organisms.

    Science.gov (United States)

    Porter, Clint M; Nairn, Robert W

    2010-10-15

    Elevated concentrations of acidity and metals in acid mine drainage (AMD) may be effectively addressed by active and passive treatment technologies. However, typical evaluations consider only chemical water quality with little if any regard for biological metrics. Robust evaluations including both chemical and biological indicators of water quality improvement are needed. In this study, injection of alkaline fluidized bed ash (FBA) into a flooded underground coal mine was coupled with a five-cell passive treatment system to ameliorate an abandoned AMD discharge in eastern Oklahoma. The passive system included process units promoting both aerobic and anaerobic treatment mechanisms. Resulting water quality changes and biological responses were evaluated. Organisms of two distinct functional groups (the filter-feeding mollusk Corbicula fluminea and the wide-spectrum feeding fish Lepomis macrochirus) were exposed to mine waters in several treatment cells. The combination of treatment technologies was hypothesized to limit potential negative effects on these aquatic organisms. Tissues were harvested and analyzed for concentrations of several metals (Al, Fe, Mn, Mg, Ca, Ni, Cu and Zn) of interest. Organismal responses, such as hepatosomatic index, condition factor, and condition index, did not vary significantly among organisms exposed within different treatment cells when compared to non-AMD impaired waters. Metal tissue accumulation trends, compared to aqueous concentrations, were observed for Fe, Ni and Zn. Exposure experiments with these two organisms indicated that FBA introductions coupled with passive treatment decreased the potential adverse effects of AMD to biological systems. Copyright © 2010 Elsevier B.V. All rights reserved.

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

    CSIR Research Space (South Africa)

    Mulopo, J

    2012-06-01

    Full Text Available The conversion of steelmaking slag (a waste product of the steelmaking process) to calcium carbonate (CaCO3) was tested using hydrochloric acid, ammonium hydroxide and carbon dioxide via a pH-swing process. Batch reactors were used to assess...

  5. 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

    International Nuclear Information System (INIS)

    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)

  6. Risk assessment and vertical distribution of thallium in paddy soils and uptake in rice plants irrigated with acid mine drainage.

    Science.gov (United States)

    Huang, Xuexia; Li, Ning; Wu, Qihang; Long, Jianyou; Luo, Dinggui; Zhang, Ping; Yao, Yan; Huang, Xiaowu; Li, Dongmei; Lu, Yayin; Liang, Jianfeng

    2016-12-01

    The objective of this paper is to assess the influence of irritating paddy fields with acid mine drainage containing thallium (Tl) to rice plant-soil system and potential health risks for local residents. Vertical distribution of Tl, pH, organic matter (OM), and cation exchange capacity (CEC) in 24 paddy soil profiles around Yunfu pyrite mine area was investigated. Rice plant samples were collected from the corresponding soil sampling site. The results showed that Tl concentrations in paddy soils at 0-60 cm depth range from 3.07 to 9.42 mg kg -1 , with a mean of 5.74 mg kg -1 , which were significantly higher than the background value of soil in China (0.58 mg kg -1 ). On the whole, Tl contents in paddy soil profiles increased quickly with soil depth from 0 to 30 cm and decreased slowly with soil depth from 30 to 60 cm. The soil Tl content was significant negatively correlated with soil pH. The mean content of Tl in the root, stem, leaf, and rice was 4.36, 1.83, 2.74, and 1.42 mg kg -1 , respectively, which exceeded the proposed permissible limits for foods and feedstuffs in Germany. The Tl content in various tissues of the rice plants followed the order root > leaf > stem (rice), which suggested that most Tl taken up by rice plants retained in the root, and a little migrated to the leaf, stem, and rice. Correlation analysis showed that Tl content in root was significant positively correlated with Tl content in leaf and rice. The ranges of hazard quotient (HQ) values were 4.08∼24.50 and 3.84∼22.38 for males and females, respectively. Males have higher health risk than females in the same age group. In childhood age groups (2 to <21 years) and adult age groups (21 to <70 years), the highest health risk level was observed in the 11 to 16 age group and 21 to 50 age group, respectively. The findings indicated that regular irrigation with Tl-bearing acid mine drainage led to considerable contamination of Tl in paddy soil and rice plant. Local government

  7. Acid mine drainage prevention, control and treatment technology development for the Stockett/Sand Coulee area. Topical report, March 1, 1995 - March 31, 1996

    International Nuclear Information System (INIS)

    Brown, T.

    1996-01-01

    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. The effects of acidic mine drainage from historical mines in the Animas River watershed, San Juan County, Colorado—What is being done and what can be done to improve water quality?

    Science.gov (United States)

    Church, Stanley E.; Owen, Robert J.; Von Guerard, Paul; Verplanck, Philip L.; Kimball, Briant A.; Yager, Douglas B.

    2007-01-01

    Historical production of metals in the western United States has left a legacy of acidic drainage and toxic metals in many mountain watersheds that are a potential threat to human and ecosystem health. Studies of the effects of historical mining on surface water chemistry and riparian habitat in the Animas River watershed have shown that cost-effective remediation of mine sites must be carefully planned. of the more than 5400 mine, mill, and prospect sites in the watershed, ∼80 sites account for more than 90% of the metal loads to the surface drainages. Much of the low pH water and some of the metal loads are the result of weathering of hydrothermally altered rock that has not been disturbed by historical mining. Some stream reaches in areas underlain by hydrothermally altered rock contained no aquatic life prior to mining.Scientific studies of the processes and metal-release pathways are necessary to develop effective remediation strategies, particularly in watersheds where there is little land available to build mine-waste repositories. Characterization of mine waste, development of runoff profiles, and evaluation of ground-water pathways all require rigorous study and are expensive upfront costs that land managers find difficult to justify. Tracer studies of water quality provide a detailed spatial analysis of processes affecting surface- and ground-water chemistry. Reactive transport models were used in conjunction with the best state-of-the-art engineering solutions to make informed and cost-effective remediation decisions.Remediation of 23% of the high-priority sites identified in the watershed has resulted in steady improvement in water quality. More than $12 million, most contributed by private entities, has been spent on remediation in the Animas River watershed. The recovery curve for aquatic life in the Animas River system will require further documentation and long-term monitoring to evaluate the effectiveness of remediation projects implemented.

  9. The role of scientists in acid mine drainage policy response in Gauteng, South Africa: Presentation

    CSIR Research Space (South Africa)

    Funke, Nicola S

    2012-10-01

    Full Text Available . This government response came after considerable publicity in the media and threats of legal action by NGOs. • Complexity: historical link between government and mines, lack of inter-departmental coordination, scientific uncertainty, many actors involved... stream_source_info Funke3_2012.pdf.txt stream_content_type text/plain stream_size 6180 Content-Encoding UTF-8 stream_name Funke3_2012.pdf.txt Content-Type text/plain; charset=UTF-8 The role of scientists in Acid Mine...

  10. PRINCIPAL COMPONENT ANALYSIS OF FACTORS DETERMINING PHOSPHATE ROCK DISSOLUTION ON ACID SOILS

    Directory of Open Access Journals (Sweden)

    Yusdar Hilman

    2016-10-01

    Full Text Available Many of the agricultural soils in Indonesia are acidic and low in both total and available phosphorus which severely limits their potential for crops production. These problems can be corrected by application of chemical fertilizers. However, these fertilizers are expensive, and cheaper alternatives such as phosphate rock (PR have been considered. Several soil factors may influence the dissolution of PR in soils, including both chemical and physical properties. The study aimed to identify PR dissolution factors and evaluate their relative magnitude. The experiment was conducted in Soil Chemical Laboratory, Universiti Putra Malaysia and Indonesian Center for Agricultural Land Resources Research and Development from January to April 2002. The principal component analysis (PCA was used to characterize acid soils in an incubation system into a number of factors that may affect PR dissolution. Three major factors selected were soil texture, soil acidity, and fertilization. Using the scores of individual factors as independent variables, stepwise regression analysis was performed to derive a PR dissolution function. The factors influencing PR dissolution in order of importance were soil texture, soil acidity, then fertilization. Soil texture factors including clay content and organic C, and soil acidity factor such as P retention capacity interacted positively with P dissolution and promoted PR dissolution effectively. Soil texture factors, such as sand and silt content, soil acidity factors such as pH, and exchangeable Ca decreased PR dissolution.

  11. Remediation of acid mine drainage at the friendship hill national historic site with a pulsed limestone bed process

    Science.gov (United States)

    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 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 process in treatment of acid impaired waters that were

  12. Remediation of acid mine drainage at the friendship hill national historic site with a pulsed limestone bed process

    Science.gov (United States)

    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 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 process in treatment of acid impaired waters that were previously not amenable to low cost limestone treatment.

  13. Removal of arsenic from synthetic acid mine drainage by electrochemical pH adjustment and coprecipitation with iron hydroxide.

    Science.gov (United States)

    Wang, Jenny Weijun; Bejan, Dorin; Bunce, Nigel J

    2003-10-01

    Acid mine drainage (AMD), which is caused by the biological oxidation of sulfidic materials, frequently contains arsenic in the form of arsenite, As(III), and/or arsenate, As(V), along with much higher concentrations of dissolved iron. The present work is directed toward the removal of arsenic from synthetic AMD by raising the pH of the solution by electrochemical reduction of H+ to elemental hydrogen and coprecipitation of arsenic with iron(III) hydroxide, following aeration of the catholyte. Electrolysis was carried out at constant current using two-compartment cells separated with a cation exchange membrane. Four different AMD model systems were studied: Fe(III)/As(V), Fe(III)/As(III), Fe(II)/As(V), and Fe(II)/As(III) with the initial concentrations for Fe(III) 260 mg/L, Fe(II) 300 mg/L, As(V), and As(III) 8 mg/L. Essentially quantitative removal of arsenic and iron was achieved in all four systems, and the results were independent of whether the pH was adjusted electrochemically or by the addition of NaOH. Current efficiencies were approximately 85% when the pH of the effluent was 4-7. Residual concentrations of arsenic were close to the drinking water standard proposed by the World Health Organization (10 microg/L), far below the mine waste effluent standard (500 microg/L).

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

    Science.gov (United States)

    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.

  15. Arsenic scavenging by aluminum-substituted ferrihydrites in a circumneutral pH river impacted by acid mine drainage.

    Science.gov (United States)

    Adra, Areej; Morin, Guillaume; Ona-Nguema, Georges; Menguy, Nicolas; Maillot, Fabien; Casiot, Corinne; Bruneel, Odile; Lebrun, Sophie; Juillot, Farid; Brest, Jessica

    2013-11-19

    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 of aluminum-rich Fh, and their role in arsenic scavenging in river-bed sediments from 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. TEM-EDXS elemental mapping and SEM-EDXS analyses combined with EXAFS analysis indicates that Al(3+) substitutes for Fe(3+) ions into the Fh structure in the natural sediment samples, with local aluminum concentration within the 25-30 ± 10 mol %Al range. Synthetic aluminous Fh prepared in the present study are found to be less Al-substituted (14-20 ± 5 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 evidence for the scavenging of arsenic by natural Al-Fh, which emphasize the possible implication of such material for scavenging pollutants in natural or engineered systems.

  16. Mineralogical characteristics of sediments and heavy metal mobilization along a river watershed affected by acid mine drainage.

    Directory of Open Access Journals (Sweden)

    Yingying Xie

    Full Text Available Trace-element concentrations in acid mine drainage (AMD are primarily controlled by the mineralogy at the sediment-water interface. Results are presented for a combined geochemical and mineralogical survey of Dabaoshan Mine, South China. Developed sequential extraction experiments with the analysis of the main mineralogical phases by semi-quantitative XRD, differential X-ray diffraction (DXRD and scanning electron microscopy (SEM were conducted to identify the quantitative relationship between iron minerals and heavy metals. Results showed that schwertmannite, jarosite, goethite and ferrihydrite were the dominant Fe-oxyhydroxide minerals which were detected alternately in the surface sediment with the increasing pH from 2.50 to 6.93 along the Hengshi River. Decreasing contents of schwertmannite ranging from 35 wt % to 6.5 wt % were detected along the Hengshi River, which was corresponding to the decreasing metal contents. The easily reducible fractions exert higher affinity of metals while compared with reducible and relatively stable minerals. A qualitative analysis of heavy metals extracted from the sediments indicated that the retention ability varied: Pb > Mn > Zn > As ≈ Cu > Cr > Cd ≈ Ni. Results in this study are avail for understanding the fate and transport of heavy metals associated with iron minerals and establishing the remediation strategies of AMD systems.

  17. Optimization of the operation of packed bed bioreactor to improve the sulfate and metal removal from acid mine drainage.

    Science.gov (United States)

    Dev, Subhabrata; Roy, Shantonu; Bhattacharya, Jayanta

    2017-09-15

    The present study discusses the potentiality of using anaerobic Packed Bed Bioreactor (PBR) for the treatment of acid mine drainage (AMD). The multiple process parameters such as pH, hydraulic retention time (HRT), concentration of marine waste extract (MWE), total organic carbon (TOC) and sulfate were optimized together using Taguchi design. The order of influence of the parameters towards biological sulfate reduction was found to be pH > MWE > sulfate > HRT > TOC. At optimized conditions (pH - 7, 20% (v/v) MWE, 1500 mg/L sulfate, 48 h HRT and 2300 mg/L TOC), 98.3% and 95% sulfate at a rate of 769.7 mg/L/d. and 732.1 mg/L/d. was removed from the AMD collected from coal and metal mine, respectively. Efficiency of metal removal (Fe, Cu, Zn, Mg and Ni) was in the range of 94-98%. The levels of contaminants in the treated effluent were below the minimum permissible limits of industrial discharge as proposed by Bureau of Indian Standards (IS 2490:1981). The present study establishes the optimized conditions for PBR operation to completely remove sulfate and metal removal from AMD at high rate. The study also creates the future scope to develop an efficient treatment process for sulfate and metal-rich mine wastewater in a large scale. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Influence of acid mine drainage on microbial communities in stream and groundwater samples at Guryong Mine, South Korea

    Science.gov (United States)

    Kim, Jaisoo; Koo, So-Yeon; Kim, Ji-Young; Lee, Eun-Hee; Lee, Sang-Don; Ko, Kyung-Seok; Ko, Dong-Chan; Cho, Kyung-Suk

    2009-10-01

    The effects of acid mine drainage (AMD) in a stream and groundwater near an abandoned copper mine were characterized by physicochemical properties, bacterial community structure using denaturing gel gradient electrophoresis (DGGE), and microbial activity/diversity using Ecoplate technique. Based on DGGE fingerprints, the eubacterial community structures grouped into the stream water (GRS1, GRS2 and GRS3) and groundwater samples (GW1 and GW2), apparently based on differences in water temperature and the concentrations of dissolved oxygen, nitrate and sulfate. The most highly AMD-contaminated sample (GRS1) had additional α-Proteobacteria whereas the groundwater samples included additional β-Proteobacteria, suggesting the development of populations resistant to AMD toxicity under aerobic and anaerobic conditions, respectively. Community level physiological activities on the 31 Ecoplate substrates suggested that the activities decreased with increasing concentrations of sulfate and heavy metals derived from AMD. The Shannon index showed that microbial diversity was greatest in GRS2, and lowest in GRS1, and was probably related to the level of AMD.

  19. Can behavioural responses of Lumbriculus variegatus (Oligochaeta) assess sediment toxicity? A case study with sediments exposed to acid mine drainage

    International Nuclear Information System (INIS)

    Sardo, A.M.; Soares, A.M.V.M.

    2010-01-01

    The Sao Domingos mine (Portugal) is, potentially, a good site for ecotoxicological studies, due to a pH and metal gradient of acid mine drainage. In this study, the toxicity of several mine sediments was evaluated using the aquatic oligochaete Lumbriculus variegatus as a test organism. Our hypothesis was that exposure to contaminated sediments would cause behavioural early warning responses in L. variegatus. Five sites, with pH ranging from 2.5 to 6.5, and with associated metals, were investigated. The results showed poor sediment quality in most of the collected sediments and Fe, S and As were the dominant elements in the samples. High mortalities were observed, ranging from 32.6 to 100%, indicating severe contamination. The collected sediments did not support good L. variegatus growth and significantly changed its behaviour. Early warning responses consisted of decreased locomotion and decreased peristaltic movements. A behaviour inhibition will affect the ecosystem balance by limiting the organisms' ability to avoid capture, which leads to a higher risk of predation. - Behavioural responses of the aquatic oligochaeta Lumbriculus variegatus may be used to detect early warning responses.

  20. Donnan membrane speciation of Al, Fe, trace metals and REEs in coastal lowland acid sulfate soil-impacted drainage waters.

    Science.gov (United States)

    Jones, Adele M; Xue, Youjia; Kinsela, Andrew S; Wilcken, Klaus M; Collins, Richard N

    2016-03-15

    Donnan dialysis has been applied to forty filtered drainage waters collected from five coastal lowland acid sulfate soil (CLASS) catchments across north-eastern NSW, Australia. Despite having average pH values70%) as negatively-charged complexes. In contrast, the speciation of the divalent trace metals Co, Mn, Ni and Zn was dominated by positively-charged complexes and was strongly correlated with the alkaline earth metals Ca and Mg. Thermodynamic equilibrium speciation calculations indicated that natural organic matter (NOM) complexes dominated Fe(III) speciation in agreement with that obtained by Donnan dialysis. In the case of Fe(II), however, the free cation was predicted to dominate under thermodynamic equilibrium, whilst our results indicated that Fe(II) was mainly present as neutral or negatively-charged complexes (most likely with sulfate). For all other divalent metals thermodynamic equilibrium speciation calculations agreed well with the Donnan dialysis results. The proportion of Al and REEs predicted to be negatively-charged was also grossly underestimated, relative to the experimental results, highlighting possible inaccuracies in the stability constants developed for these trivalent Me(SO4)2(-) and/or Me-NOM complexes and difficulties in modeling complex environmental samples. These results will help improve metal mobility and toxicity models developed for CLASS-affected environments, and also demonstrate that Australian CLASS environments can discharge REEs at concentrations an order of magnitude greater than previously reported. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Guo, Lin; Cutright, Teresa J

    2016-01-01

    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.

  2. Mineralogical characteristics of sediments and heavy metal mobilization along a river watershed affected by acid mine drainage.

    Science.gov (United States)

    Xie, Yingying; Lu, Guining; Yang, Chengfang; Qu, Lu; Chen, Meiqin; Guo, Chuling; Dang, Zhi

    2018-01-01

    Trace-element concentrations in acid mine drainage (AMD) are primarily controlled by the mineralogy at the sediment-water interface. Results are presented for a combined geochemical and mineralogical survey of Dabaoshan Mine, South China. Developed sequential extraction experiments with the analysis of the main mineralogical phases by semi-quantitative XRD, differential X-ray diffraction (DXRD) and scanning electron microscopy (SEM) were conducted to identify the quantitative relationship between iron minerals and heavy metals. Results showed that schwertmannite, jarosite, goethite and ferrihydrite were the dominant Fe-oxyhydroxide minerals which were detected alternately in the surface sediment with the increasing pH from 2.50 to 6.93 along the Hengshi River. Decreasing contents of schwertmannite ranging from 35 wt % to 6.5 wt % were detected along the Hengshi River, which was corresponding to the decreasing metal contents. The easily reducible fractions exert higher affinity of metals while compared with reducible and relatively stable minerals. A qualitative analysis of heavy metals extracted from the sediments indicated that the retention ability varied: Pb > Mn > Zn > As ≈ Cu > Cr > Cd ≈ Ni. Results in this study are avail for understanding the fate and transport of heavy metals associated with iron minerals and establishing the remediation strategies of AMD systems.

  3. Ecological benefits of passive wetland treatment systems designed for acid mine drainage: With emphasis on watershed restoration

    International Nuclear Information System (INIS)

    McCleary, E.C.; Kepler, D.A.

    1994-01-01

    Western Pennsylvania has been a large source of coal for much of the US since the late 1800's. During the extraction of the coal resources, acid mine drainage (AMD) often resulted. AMD from abandoned discharges has effectively rendered thousands of kilometers of streams lifeless in the Appalachian coal region. Restoration of these streams has been limited in previous years primarily because of the lack of cost-effective treatment for AMD. Conventional treatment can treat AMD effectively but is costly to operate and maintain and is effective only when receiving human attention. Passive wetland treatment systems have proven to be the only realistic AMD treatment strategy, in terms of watershed restoration activities. If ecosystem health is the reason for implementing effluent standards then it can be reasonably argued that passive wetland treatment systems supply the most effective overall treatment, even if they do not meet one or more of the current effluent standards. Recent advancements in passive wetland treatment system technology have provided a management tool that could be used to treat the majority of AMD discharges cost-effectively, and when used strategically could reasonably be employed to restore the thousands of kilometers of AMD-affected streams in the coal regions of Appalachia. Secondary benefits that have been observed with passive wetland treatment systems suggest that these systems may be providing for accelerated ecological recovery independent of regulated effluent standards

  4. Biologically-induced precipitation of sphalerite-wurtzite nanoparticles by sulfate-reducing bacteria: implications for acid mine drainage treatment.

    Science.gov (United States)

    Castillo, Julio; Pérez-López, Rafael; Caraballo, Manuel A; Nieto, José M; Martins, Mónica; Costa, M Clara; Olías, Manuel; Cerón, Juan C; Tucoulou, Rémi

    2012-04-15

    Several experiments were conducted to evaluate zinc-tolerance of sulfate-reducing bacteria (SRB) obtained from three environmental samples, two inocula from sulfide-mining districts and another inoculum from a wastewater treatment plant. The populations of SRB resisted zinc concentrations of 260 mg/L for 42 days in a sulfate-rich medium. During the experiments, sulfate was reduced to sulfide and concentrations in solution decreased. Zinc concentrations also decreased from 260 mg/L to values below detection limit. Both decreases were consistent with the precipitation of newly-formed sphalerite and wurtzite, two polymorphs of ZnS, forming <2.5-μm-diameter spherical aggregates identified by microscopy and synchrotron-μ-XRD. Sulfate and zinc are present in high concentrations in acid mine drainage (AMD) even after passive treatments based on limestone dissolution. The implementation of a SRB-based zinc removal step in these systems could completely reduce the mobility of all metals, which would improve the quality of stream sediments, water and soils in AMD-affected landscapes. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Electrochemically active microorganisms from an acid mine drainage-affected site promote cathode oxidation in microbial fuel cells

    KAUST Repository

    Rojas, Claudia; Vargas, Ignacio T.; Bruns, Mary Ann; Regan, John M.

    2017-01-01

    The limited database of acidophilic or acidotolerant electrochemically active microorganisms prevents advancements on microbial fuel cells (MFCs) operated under low pH. In this study, three MFCs were used to enrich cathodic biofilms using acid mine drainage (AMD) sediments as inoculum. Linear sweep voltammetry showed cathodic current plateaus of 5.5 (± 0.7) mA at about − 170 mV vs Ag/AgCl and 8.5 (± 0.9) mA between − 500 mV to − 450 mV vs Ag/AgCl for biofilms developed on small graphite fiber brushes. After gamma irradiation, biocathodes exhibited a decrease in current density approaching that of abiotic controls. Electrochemical impedance spectroscopy showed six-fold lower charge transfer resistance with viable biofilm. Pyrosequencing data showed that Proteobacteria and Firmicutes dominated the biofilms. Acidithiobacillus representatives were enriched in some biocathodes, supporting the potential importance of these known iron and sulfur oxidizers as cathodic biocatalysts. Other acidophilic chemolithoautotrophs identified included Sulfobacillus and Leptospirillum species. The presence of chemoautotrophs was consistent with functional capabilities predicted by PICRUSt related to carbon fixation pathways in prokaryotic microorganisms. Acidophilic or acidotolerant heterotrophs were also abundant; however, their contribution to cathodic performance is unknown. This study directs subsequent research efforts to particular groups of AMD-associated bacteria that are electrochemically active on cathodes.

  6. Electrochemically active microorganisms from an acid mine drainage-affected site promote cathode oxidation in microbial fuel cells

    KAUST Repository

    Rojas, Claudia

    2017-08-03

    The limited database of acidophilic or acidotolerant electrochemically active microorganisms prevents advancements on microbial fuel cells (MFCs) operated under low pH. In this study, three MFCs were used to enrich cathodic biofilms using acid mine drainage (AMD) sediments as inoculum. Linear sweep voltammetry showed cathodic current plateaus of 5.5 (± 0.7) mA at about − 170 mV vs Ag/AgCl and 8.5 (± 0.9) mA between − 500 mV to − 450 mV vs Ag/AgCl for biofilms developed on small graphite fiber brushes. After gamma irradiation, biocathodes exhibited a decrease in current density approaching that of abiotic controls. Electrochemical impedance spectroscopy showed six-fold lower charge transfer resistance with viable biofilm. Pyrosequencing data showed that Proteobacteria and Firmicutes dominated the biofilms. Acidithiobacillus representatives were enriched in some biocathodes, supporting the potential importance of these known iron and sulfur oxidizers as cathodic biocatalysts. Other acidophilic chemolithoautotrophs identified included Sulfobacillus and Leptospirillum species. The presence of chemoautotrophs was consistent with functional capabilities predicted by PICRUSt related to carbon fixation pathways in prokaryotic microorganisms. Acidophilic or acidotolerant heterotrophs were also abundant; however, their contribution to cathodic performance is unknown. This study directs subsequent research efforts to particular groups of AMD-associated bacteria that are electrochemically active on cathodes.

  7. Metal transport and remobilisation in a basin affected by acid mine drainage

    DEFF Research Database (Denmark)

    Consani, Sirio; Carbone, Cristina; Dinelli, Enrico

    2017-01-01

    Metal-polluted mine waters represent a major threat to the quality of waters and sediments in a downstream basin. At the confluence between acidic mine waters and the unpolluted waters of the Gromolo Torrent (Liguria, North-West Italy), the massive formation of an ochreous amorphous precipitate...... takes place. This precipitate forms a soft blanket that covers the torrent bed and can be observed down to its mouth in the sea. The aim of this work is to evaluate the dispersion of metals in the Gromolo Torrent basin from the abandoned Cu-Fe sulphide mine of Libiola to the Ligurian Sea and to assess...... the metal remobilisation from the amorphous precipitates. The mineralogy of the superficial sediments collected in the torrent bed and the concentrations of different elements of environmental concern (Cu, Zn, Cd, Co, Cr, Mn, Ni, Pb, As, and Sb) were therefore analysed. The results showed...

  8. Bioremediation of Acidic and Metalliferous Drainage (AMD) through organic carbon amendment by municipal sewage and green waste.

    Science.gov (United States)

    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. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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

  10. Towards "Precision Mining" of wastewater: Selective recovery of Cu from acid mine drainage onto diatomite supported nanoscale zerovalent iron particles.

    Science.gov (United States)

    Crane, R A; Sapsford, D J

    2018-07-01

    This paper introduces the concept of 'Precision Mining' of metals which can be defined as a process for the selective in situ uptake of a metal from a material or media, with subsequent retrieval and recovery of the target metal. In order to demonstrate this concept nanoscale zerovalent iron (nZVI) was loaded onto diatomaceous earth (DE) and tested for the selective uptake of Cu from acid mine drainage (AMD) and subsequent release. Batch experiments were conducted using the AMD and nZVI-DE at 4.0-16.0 g/L. Results demonstrate nZVI-DE as highly selective for Cu removal with >99% uptake recorded after 0.25 h when using nZVI-DE concentrations ≥12.0 g/L, despite appreciable concentrations of numerous other metals in the AMD, namely: Co, Ni, Mn and Zn. Cu uptake was maintained in excess of 4 and 24 h when using nZVI-DE concentrations of 12.0 and 16.0 g/L respectively. Near-total Cu release from the nZVI-DE was then recorded and attributed to the depletion of the nZVI component and the subsequent Eh, DO and pH recovery. This novel Cu uptake and release mechanism, once appropriately engineered, holds great promise as a novel 'Precision Mining' process for the rapid and selective Cu recovery from acidic wastewater, process effluents and leach liquors. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    Science.gov (United States)

    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.

  12. Tetrathionate and Elemental Sulfur Shape the Isotope Composition of Sulfate in Acid Mine Drainage

    Directory of Open Access Journals (Sweden)

    Nurgul Balci

    2017-08-01

    Full Text Available Sulfur compounds in intermediate valence states, for example elemental sulfur, thiosulfate, and tetrathionate, are important players in the biogeochemical sulfur cycle. However, key understanding about the pathways of oxidation involving mixed-valance state sulfur species is still missing. Here we report the sulfur and oxygen isotope fractionation effects during the oxidation of tetrathionate (S4O62− and elemental sulfur (S° to sulfate in bacterial cultures in acidic conditions. Oxidation of tetrathionate by Acidithiobacillus thiooxidans produced thiosulfate, elemental sulfur and sulfate. Up to 34% of the tetrathionate consumed by the bacteria could not be accounted for in sulfate or other intermediate-valence state sulfur species over the experiments. The oxidation of tetrathionate yielded sulfate that was initially enriched in 34S (ε34SSO4−S4O6 by +7.9‰, followed by a decrease to +1.4‰ over the experiment duration, with an average ε34SSO4−S4O6 of +3.5 ± 0.2‰ after a month of incubation. We attribute this significant sulfur isotope fractionation to enzymatic disproportionation reactions occurring during tetrathionate decomposition, and to the incomplete transformation of tetrathionate into sulfate. The oxygen isotope composition of sulfate (δ18OSO4 from the tetrathionate oxidation experiments indicate that 62% of the oxygen in the formed sulfate was derived from water. The remaining 38% of the oxygen was either inherited from the supplied tetrathionate, or supplied from dissolved atmospheric oxygen (O2. During the oxidation of elemental sulfur, the product sulfate became depleted in 34S between −1.8 and 0‰ relative to the elemental sulfur with an average for ε34SSO4−S0 of −0.9 ± 0.2‰ and all the oxygen atoms in the sulfate derived from water with an average normal oxygen isotope fractionation (ε18OSO4−H2O of −4.4‰. The differences observed in δ18OSO4 and the sulfur isotope composition of sulfate (δ34SSO4

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

    Science.gov (United States)

    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

  14. Geochemistry of REE in Acid Mine Drainage: Sorption onto Basaluminite and Schwertmannite.

    Science.gov (United States)

    Lozano Letellier, A.; Ayora, C.; Fernandez-Martinez, A.

    2017-12-01

    The geochemistry of Rare Earth Elements (REE) has been investigated in natural streams and in mine areas during the last decades. Most of these studies agree that REE are mobile in acidic waters and they transferred to a solid phase when pH increases. However, there is no agreement on the pH range, on which precipitates can retain REE and the mechanisms responsible for the retention. Thus, whereas some authors determined that hydrous ferric oxides (HFOs) scavenge REE from pH 3, other authors observed REE retention by hydrous aluminum oxides (HAOs) from pH 4 to 6.1. A field survey conducted in the Odiel River in the SW Spain showed that pH values higher than 5, REE, Cu, Al and Fe concentrations in the river were lower than expected from a theoretical mixture because they were trapped in the precipitates. For pH below 4, however, only schwertmannite (Fe8O8OH6SO4) and no basaluminite (Al4SO4OH10·5H2O) precipitated. Then, REE, Cu and Al behaved conservatively and Fe does not, indicating that REE are trapped in the Al but not in the Fe solid phase. These observations are perfectly consistent with the REE accumulation in the Al-rich precipitates in the AMD treatment systems. Taking into account these observations, sorption experiments with synthetic basaluminite and schwertmannite at different pH were performed in the laboratory. For Lanthanides and Yttrium, sorption edge took place at pH higher than 5, whereas Sc sorption started at pH 4. A surface complexation model is proposed to explain the retention mechanism onto these two precipitates. Both minerals, schwertmannite and basaluminite showed similar sorption behavior. However, as schwertmannite formation occurs at pH lower than 4, no REE elements are sorbed on it.

  15. Quantitative microbial community analysis of three different sulfidic mine tailing dumps generating acid mine drainage.

    Science.gov (United States)

    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.

  16. 13 Morphometric Analysis of Ogunpa and Ogbere Drainage Basins ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    form and process of drainage basins that may be widely ... ferruginous tropical soil on basement complex rock (Areola ... landuse pattern control the infiltration loss, the distribution of ... the water intercepted by Ogbere drainage basin to longer ...

  17. Mineral-microorganism interactions in Acid Mine Drainage environments: preliminary results

    Science.gov (United States)

    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

  18. Hydrogeochemistry and microbiology of mine drainage: An update

    Science.gov (United States)

    Nordstrom, D. Kirk; Blowes, D.W; Ptacek, C.J.

    2015-01-01

    The extraction of mineral resources requires access through underground workings, or open pit operations, or through drillholes for solution mining. Additionally, mineral processing can generate large quantities of waste, including mill tailings, waste rock and refinery wastes, heap leach pads, and slag. Thus, through mining and mineral processing activities, large surface areas of sulfide minerals can be exposed to oxygen, water, and microbes, resulting in accelerated oxidation of sulfide and other minerals and the potential for the generation of low-quality drainage. The oxidation of sulfide minerals in mine wastes is accelerated by microbial catalysis of the oxidation of aqueous ferrous iron and sulfide. These reactions, particularly when combined with evaporation, can lead to extremely acidic drainage and very high concentrations of dissolved constituents. Although acid mine drainage is the most prevalent and damaging environmental concern associated with mining activities, generation of saline, basic and neutral drainage containing elevated concentrations of dissolved metals, non-metals, and metalloids has recently been recognized as a potential environmental concern. Acid neutralization reactions through the dissolution of carbonate, hydroxide, and silicate minerals and formation of secondary aluminum and ferric hydroxide phases can moderate the effects of acid generation and enhance the formation of secondary hydrated iron and aluminum minerals which may lessen the concentration of dissolved metals. Numerical models provide powerful tools for assessing impacts of these reactions on water quality.

  19. Combined effects of spatially variable flow and mineralogy on the attenuation of acid mine drainage in groundwater

    International Nuclear Information System (INIS)

    Malmstroem, Maria E.; Berglund, Sten; Jarsjoe, Jerker

    2008-01-01

    Quantifications of the spreading of acid mine drainage (AMD) in groundwater are needed for risk assessments of mining sites. However, due to subsurface heterogeneity, available field data may prove insufficient for deterministic process descriptions, even at well-characterized sites. Here, the probabilistic LaSAR-PHREEQC model is used to consider multicomponent reactions and transport in heterogeneous (flow and geochemistry) groundwater surrounding a mine waste site, with specific focus on the spreading of Zn. Model results, using field data from a mill tailings impoundment in northern Sweden (including major component geochemistry), indicate that precipitation of smithsonite (ZnCO 3 ) may drastically delay the downstream arrival of Zn, but may also cause a peak concentration once the retained Zn is released. The amount of smithsonite formed is, however, minute and its spatial variation large, such that detection of smithsonite in soil samples may be difficult. Results further show that even a low degree of flow heterogeneity can effectively smooth otherwise distinctive temporal concentration changes attributed to the considered chemical reactions, and thereby mask the attenuation processes. By contrast, the existence of preferential flow paths can cause temporally separated concentration peaks in response to a single chemical reaction chain, even in a geochemically homogeneous domain, making the interpretation of the concentration curves non-trivial. The stochastic modelling results for Zn considering flow and/or mineralogical heterogeneity indicate a less efficient Zn attenuation than predicted by standard, deterministic reactive-transport models. In addition, in all considered probabilistic Zn and SO 4 2- scenarios, the spatial variability in downstream pollutant concentration was high, implying that a relatively large number of point samples are needed to determine field-scale mean concentrations

  20. Monitoring the Extent of Contamination from Acid Mine Drainage in the Iberian Pyrite Belt (SW Spain Using Hyperspectral Imagery

    Directory of Open Access Journals (Sweden)

    Asuncion Riaza

    2011-10-01

    Full Text Available Monitoring mine waste from sulfide deposits by hyperspectral remote sensing can be used to predict surface water quality by quantitatively estimating acid drainage and metal contamination on a yearly basis. In addition, analysis of the mineralogy of surface crusts rich in soluble salts can provide a record of annual humidity and temperature. In fact, temporal monitoring of salt efflorescence from mine wastes at a mine site in the Iberian Pyrite Belt (Huelva, Spain has been achieved using hyperspectral airborne Hymap data. Furthermore, climate variability estimates are possible based on oxidation stages derived from well-known sequences of minerals, by tracing sulfide oxidation intensity using archive spectral libraries. Thus, airborne and spaceborne hyperspectral remote sensing data can be used to provide a short-term record of climate change, and represent a useful set of tools for assessing environmental geoindicators in semi-arid areas. Spectral and geomorphological indicators can be monitored on a regular basis through image processing, supported by field and laboratory spectral data. In fact, hyperspectral image analysis is one of the methods selected by the Joint Research Centre of the European Community (Ispra, Italy to study abandoned mine sites, in order to assess the enforcement of the European Mine Waste Directive (2006/21/EC of the European Parliament and of the Council 15 March 2006 on the management of waste from extractive industries (Official Journal of the European Union, 11 April 2006. The pyrite belt in Andalucia has been selected as one of the core mission test sites for the PECOMINES II program (Cracow, November 2005, using imaging spectroscopy; and this technique is expected to be implemented as a monitoring tool by the Environmental Net of Andalucía (REDIAM, Junta de Andalucía, Spain.

  1. The precipitation of indium at elevated pH in a stream influenced by acid mine drainage

    Science.gov (United States)

    White, Sarah Jane O.; Hussain, Fatima A.; Hemond, Harold F.; Sacco, Sarah A.; Shine, James P.; Runkel, Robert L.; Walton-Day, Katherine; Kimball, Briant A.

    2017-01-01

    Indium is an increasingly important metal in semiconductors and electronics and has uses in important energy technologies such as photovoltaic cells and light-emitting diodes (LEDs). One significant flux of indium to the environment is from lead, zinc, copper, and tin mining and smelting, but little is known about its aqueous behavior after it is mobilized. In this study, we use Mineral Creek, a headwater stream in southwestern Colorado severely affected by heavy metal contamination as a result of acid mine drainage, as a natural laboratory to study the aqueous behavior of indium. At the existing pH of ~ 3, indium concentrations are 6–29 μg/L (10,000 × those found in natural rivers), and are completely filterable through a 0.45 μm filter. During a pH modification experiment, the pH of the system was raised to > 8, and > 99% of the indium became associated with the suspended solid phase (i.e. does not pass through a 0.45 μm filter). To determine the mechanism of removal of indium from the filterable and likely primarily dissolved phase, we conducted laboratory experiments to determine an upper bound for a sorption constant to iron oxides, and used this, along with other published thermodynamic constants, to model the partitioning of indium in Mineral Creek. Modeling results suggest that the removal of indium from the filterable phase is consistent with precipitation of indium hydroxide from a dissolved phase. This work demonstrates that nonferrous mining processes can be a significant source of indium to the environment, and provides critical information about the aqueous behavior of indium.

  2. Assessment of acid mine drainage remediation schemes on ground water flow regimes at a reclaimed mine site

    International Nuclear Information System (INIS)

    Gabr, M.A.; Bowders, J.J.

    1994-01-01

    Ground water modeling and a field monitoring program were conducted for a 35-acre reclaimed surface mine site that continues to produce acid mine drainage (AMD). The modeling effort was focused on predicting the effectiveness of various remedial measures implemented at the site for the abatement of AMD on predicting the effectiveness of various remedial measures implemented at the site for the abatement of AMD production. The field work included surface surveys and monitoring of ground water levels with time, seepage areas, and sedimentation ponds located on the site. The surveys provided the physical and topographic characteristics of the site. Pump tests conducted at the site provided general hydraulic conductivities (k) for two major areas of the site; undisturbed area (k ≅ 2.9 x 10 -5 ft/s) and disturbed area (k ≅ 3.3 x 10 -4 ft/s to 2.0 x 10 -3 ft/s). The monitored ground water data indicated rapid change in ground water levels during recharge events. Such behavior is indicative of flow regime that is dominated by fracture flow. Modeling of an approximately 700 ft by 1,500 ft area of the site was achieved using the US GS code MODFLOW, and ground water field measurements were used to calibrate the model. A hydraulic conductivity of about 1.15 x 10 -3 ft/s was estimated for the undisturbed area and 1.15 x 10 -2 ft/s for the reclaimed area. Remedial measures for diverting the ground water away from the areas of spoil included the use of a subsurface seepage cutoff wall and discrete sealing techniques. Modeling results indicated that the most effective remedial technique for this site is the use of a subsurface seepage cutoff wall installed at the interface (highwall) between the disturbed and undisturbed zones. Using this scheme caused a dewatering effect in the reclaimed area and therefore reduction in the volume of the AMD generated at the site

  3. Population genomic analysis of strain variation in Leptospirillum group II bacteria involved in acid mine drainage formation.

    Science.gov (United States)

    Simmons, Sheri L; Dibartolo, Genevieve; Denef, Vincent J; Goltsman, Daniela S Aliaga; Thelen, Michael P; Banfield, Jillian F

    2008-07-22

    Deeply sampled community genomic (metagenomic) datasets enable comprehensive analysis of heterogeneity in natural microbial populations. In this study, we used sequence data obtained from the dominant member of a low-diversity natural chemoautotrophic microbial community to determine how coexisting closely related individuals differ from each other in terms of gene sequence and gene content, and to uncover evidence of evolutionary processes that occur over short timescales. DNA sequence obtained from an acid mine drainage biofilm was reconstructed, taking into account the effects of strain variation, to generate a nearly complete genome tiling path for a Leptospirillum group II species closely related to L. ferriphilum (sampling depth approximately 20x). The population is dominated by one sequence type, yet we detected evidence for relatively abundant variants (>99.5% sequence identity to the dominant type) at multiple loci, and a few rare variants. Blocks of other Leptospirillum group II types ( approximately 94% sequence identity) have recombined into one or more variants. Variant blocks of both types are more numerous near the origin of replication. Heterogeneity in genetic potential within the population arises from localized variation in gene content, typically focused in integrated plasmid/phage-like regions. Some laterally transferred gene blocks encode physiologically important genes, including quorum-sensing genes of the LuxIR system. Overall, results suggest inter- and intrapopulation genetic exchange involving distinct parental genome types and implicate gain and loss of phage and plasmid genes in recent evolution of this Leptospirillum group II population. Population genetic analyses of single nucleotide polymorphisms indicate variation between closely related strains is not maintained by positive selection, suggesting that these regions do not represent adaptive differences between strains. Thus, the most likely explanation for the observed patterns of

  4. Population genomic analysis of strain variation in Leptospirillum group II bacteria involved in acid mine drainage formation.

    Directory of Open Access Journals (Sweden)

    Sheri L Simmons

    2008-07-01

    Full Text Available Deeply sampled community genomic (metagenomic datasets enable comprehensive analysis of heterogeneity in natural microbial populations. In this study, we used sequence data obtained from the dominant member of a low-diversity natural chemoautotrophic microbial community to determine how coexisting closely related individuals differ from each other in terms of gene sequence and gene content, and to uncover evidence of evolutionary processes that occur over short timescales. DNA sequence obtained from an acid mine drainage biofilm was reconstructed, taking into account the effects of strain variation, to generate a nearly complete genome tiling path for a Leptospirillum group II species closely related to L. ferriphilum (sampling depth approximately 20x. The population is dominated by one sequence type, yet we detected evidence for relatively abundant variants (>99.5% sequence identity to the dominant type at multiple loci, and a few rare variants. Blocks of other Leptospirillum group II types ( approximately 94% sequence identity have recombined into one or more variants. Variant blocks of both types are more numerous near the origin of replication. Heterogeneity in genetic potential within the population arises from localized variation in gene content, typically focused in integrated plasmid/phage-like regions. Some laterally transferred gene blocks encode physiologically important genes, including quorum-sensing genes of the LuxIR system. Overall, results suggest inter- and intrapopulation genetic exchange involving distinct parental genome types and implicate gain and loss of phage and plasmid genes in recent evolution of this Leptospirillum group II population. Population genetic analyses of single nucleotide polymorphisms indicate variation between closely related strains is not maintained by positive selection, suggesting that these regions do not represent adaptive differences between strains. Thus, the most likely explanation for the

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

    Science.gov (United States)

    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. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Sulfate migration in a river affected by acid mine drainage from the Dabaoshan mining area, South China.

    Science.gov (United States)

    Chen, Meiqin; Lu, Guining; Guo, Chuling; Yang, Chengfang; Wu, Jingxiong; Huang, Weilin; Yee, Nathan; Dang, Zhi

    2015-01-01

    Sulfate, a major component of acid mine drainage (AMD), its migration in an AMD-affected river which located at the Dabaoshan mine area of South China was investigated to pursue the remediation strategy. The existing factors of relatively low pH values of 2.8-3.9, high concentrations of SO4(2-) (∼1940 mg L(-1)) and Fe(3+) (∼112 mg L(-1)) facilitated the precipitation of schwertmannite (Fe8O8(OH)6SO4·nH2O) in the upstream river. Geochemical model calculations implied the river waters were supersaturated, creating the potential for precipitation of iron oxyhydroxides. These minerals evolved from schwertmannite to goethite with the increasing pH from 2.8 to 5.8 along the river. The concentration of heavy metals in river waters was great reduced as a result of precipitation effects. The large size of the exchangeable sulfate pool suggested that the sediments had a strong capacity to bind SO4(2-). The XRD results indicated that schwertmannite was the predominant form of sulfate-bearing mineral phases, which was likely to act as a major sulfate sink by incorporating water-borne sulfate into its internal structure and adsorbing it onto its surface. The small size of reduced sulfur pools and strong oxidative status in the surface sediments further showed that SO4(2-) shifting from water to sediment in form of sulfate reduction was not activated. In short, precipitation of sulfate-rich iron oxyhydroxides and subsequent SO4(2-) adsorption on these minerals as well as water dilution contributed to the attenuation of SO4(2-) along the river waters. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Exploration of diffuse and discrete sources of acid mine drainage to a headwater mountain stream in Colorado, USA

    Science.gov (United States)

    Johnston, Allison; Runkel, Robert L.; Navarre-Sitchler, Alexis; Singha, Kamini

    2017-01-01

    We investigated the impact of acid mine drainage (AMD) contamination from the Minnesota Mine, an inactive gold and silver mine, on Lion Creek, a headwater mountain stream near Empire, Colorado. The objective was to map the sources of AMD contamination, including discrete sources visible at the surface and diffuse inputs that were not readily apparent. This was achieved using geochemical sampling, in-stream and in-seep fluid electrical conductivity (EC) logging, and electrical resistivity imaging (ERI) of the subsurface. The low pH of the AMD-impacted water correlated to high fluid EC values that served as a target for the ERI. From ERI, we identified two likely sources of diffuse contamination entering the stream: (1) the subsurface extent of two seepage faces visible on the surface, and (2) rainfall runoff washing salts deposited on the streambank and in a tailings pile on the east bank of Lion Creek. Additionally, rainfall leaching through the tailings pile is a potential diffuse source of contamination if the subsurface beneath the tailings pile is hydraulically connected with the stream. In-stream fluid EC was lowest when stream discharge was highest in early summer and then increased throughout the summer as stream discharge decreased, indicating that the concentration of dissolved solids in the stream is largely controlled by mixing of groundwater and snowmelt. Total dissolved solids (TDS) load is greatest in early summer and displays a large diel signal. Identification of diffuse sources and variability in TDS load through time should allow for more targeted remediation options.

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

    Science.gov (United States)

    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.

  9. ADSORPTION OF MANGANESE FROM ACID MINE DRAINAGE EFFLUENTS USING BONE CHAR: CONTINUOUS FIXED BED COLUMN AND BATCH DESORPTION STUDIES

    Directory of Open Access Journals (Sweden)

    D. C. Sicupira

    2015-06-01

    Full Text Available AbstractIn the present study, continuous fixed bed column runs were carried out in an attempt to evaluate the feasibility of using bone char for the removal of manganese from acid mine drainage (AMD. Tests using a laboratory solution of pure manganese at typical concentration levels were also performed for comparison purposes. The following operating variables were evaluated: column height, flow rate, and initial pH. Significant variations in resistance to the mass transfer of manganese into the bone char were identified using the Thomas model. A significant effect of the bed height could only be observed in tests using the laboratory solution. No significant change in the breakthrough volume could be observed with different flow rates. By increasing the initial pH from 2.96 to 5.50, the breakthrough volume was also increased. The maximum manganese loading capacity in continuous tests using bone char for AMD effluents was 6.03 mg g-1, as compared to 26.74 mg g-1 when using the laboratory solution. The present study also performed desorption tests, using solutions of HCl, H2SO4, and water, aimed at the reuse of the adsorbent; however, no promising results were obtained due to low desorption levels associated with a relatively high mass loss. Despite the desorption results, the removal of manganese from AMD effluents using bone char as an adsorbent is technically feasible and attends to environmental legislation. It is interesting to note that the use of bone char for manganese removal may avoid the need for pH corrections of effluents after treatment. Moreover, bone char can also serve to remove fluoride ions and other metals, thus representing an interesting alternative material for the treatment of AMD effluents.

  10. Magmatic and petrologic evolution of the mesozvic vulcanic acid rocks from Piraju-Ourinhos region (SP-PR)

    International Nuclear Information System (INIS)

    Raposo, M.I.B.

    1987-01-01

    This work presents the result of geological, petrological and geochemical studies, on the volcanic rocks from Piraju-Ourinhos region, SP, with special emphasis on the rocks. A geological mapping was carried out by using images from Landsat satellite. Petrographic and chemical analyses have defined a suite represented by basic lithotype - tholeutic andesibasalt - with high TiO 2 , rich in incompable elements - mainly Sr, Zr, La, Ce, and Ba - and by acid lithotype - rhyolite - rhyodacite. k-Ar ages are determined in feldspar concentrated, and indicate an age of 133+- 4m,y, for the volcanic acid rocks. Determinations of Sr isotopes. In order to explain the genesis of Chapeco type acid magnas quantitative models were tested using both fractional Crystallization [pt

  11. A Novel Uncultured Bacterium of the Family Gallionellaceae: Description and Genome Reconstruction Based on the Metagenomic Analysis of Microbial Community in Acid Mine Drainage.

    Science.gov (United States)

    Kadnikov, V V; Ivasenko, D A; Beletsky, A V; Mardanov, A V; Danilova, E V; Pimenov, N V; Karnachuk, O V; Ravin, N V

    2016-07-01

    Drainage waters at the metal mining areas often have low pH and high content of dissolved metals due to oxidation of sulfide minerals. Extreme conditions limit microbial diversity in- such ecosystems. A drainage water microbial community (6.5'C, pH 2.65) in an open pit at the Sherlovaya Gora polymetallic open-cast mine (Transbaikal region, Eastern Siberia, Russia) was studied using metagenomic techniques. Metagenome sequencing provided information for taxonomic and functional characterization of the micro- bial community. The majority of microorganisms belonged to a single uncultured lineage representing a new Betaproteobacteria species of the genus Gallionella. While no.acidophiles are known among the cultured members of the family Gallionellaceae, similar 16S rRNA gene sequences were detected in acid mine drain- ages. Bacteria ofthe genera Thiobacillus, Acidobacterium, Acidisphaera, and Acidithiobacillus,-which are com- mon in acid mine drainage environments, were the minor components of the community. Metagenomic data were -used to determine the almost complete (-3.4 Mb) composite genome of the new bacterial. lineage desig- nated Candidatus Gallionella acididurans ShG14-8. Genome analysis revealed that Fe(II) oxidation probably involved the cytochromes localized on the outer membrane of the cell. The electron transport chain included NADH dehydrogenase, a cytochrome bc1 complex, an alternative complex III, and cytochrome oxidases of the bd, cbb3, and bo3 types. Oxidation of reduced sulfur compounds probably involved the Sox system, sul- fide-quinone oxidoreductase, adenyl sulfate reductase, and sulfate adenyltransferase. The genes required for autotrophic carbon assimilation via the Calvin cycle were present, while no pathway for nitrogen fixation was revealed. High numbers of RND metal transporters and P type ATPases were probably responsible for resis- tance to heavy metals. The new microorganism was an aerobic chemolithoautotroph of the group of

  12. Sulfide oxidation and acid mine drainage formation within two active tailings impoundments in the Golden Quadrangle of the Apuseni Mountains, Romania.

    Science.gov (United States)

    Sima, Mihaela; Dold, Bernhard; Frei, Linda; Senila, Marin; Balteanu, Dan; Zobrist, Jurg

    2011-05-30

    Sulfidic mine tailings have to be classified as one of the major source of hazardous materials leading to water contamination. This study highlights the processes leading to sulfide oxidation and acid mine drainage (AMD) formation in the active stage of two tailings impoundments located in the southern part of the Apuseni Mountains, in Romania, a well-known region for its long-term gold-silver and metal mining activity. Sampling was undertaken when both impoundments were still in operation in order to assess their actual stage of oxidation and long-term behavior in terms of the potential for acid mine drainage generation. Both tailings have high potential for AMD formation (2.5 and 3.7 wt.% of pyrite equivalent, respectively) with lesser amount of carbonates (5.6 and 3.6 wt.% of calcite equivalent) as neutralization potential (ABA=-55.6 and -85.1 tCaCO(3)/1000 t ) and showed clear signs of sulfide oxidation yet during operation. Sequential extraction results indicate a stronger enrichment and mobility of elements in the oxidized tailings: Fe as Fe(III) oxy-hydroxides and oxides (transformation from sulfide minerals, leaching in oxidation zone), Ca mainly in water soluble and exchangeable form where gypsum and calcite are dissolved and higher mobility of Cu for Ribita and Pb for Mialu. Two processes leading to the formation of mine drainage at this stage could be highlighted (1) a neutral Fe(II) plume forming in the impoundment with ferrihydrite precipitation at its outcrop and (2) acid mine drainage seeping in the unsaturated zone of the active dam, leading to the formation of schwertmannite at its outcrop. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. BIOGEOCHEMICAL PROCESSES CONTROLLING MIDDAY FERROUS IRON MAXIMA IN STREAM WATERS AFFECTED BY ACID ROCK DRAINAGE. (R829640)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. Phosphorus availability in an acid tropical soil amended with phosphate rocks

    International Nuclear Information System (INIS)

    Zaharah, A.R.; Sharifuddin, H.A.H.

    2002-01-01

    The fate of P from phosphate rocks applied to Malaysian soils has not been studied in detail. Since the plantation sector is the major consumer of phosphate rock (PR) in Malaysia, studies on the dissolution and agronomic effectiveness of PR are of great interest to the country. Thus a series of greenhouse and laboratory experiments involving conventional chemical extractants and 32 P isotopic techniques was carried out to evaluate the agronomic effectiveness of PR sources of different reactivity. Phosphorus and other chemical properties of the soil and PRs studied were determined. The P solubility tests by 2% formic acid, 2% citric acid and neutral ammonium citrate gave positive correlation with P uptake by one-year old oil palm seedlings. Neutral ammonium citrate proved to be a better indicator of PR solubility and its correlation coefficient with P uptake improved by expressing citrate solubility as a percentage of the rock rather than as a percentage of total P 2 0 5 content. The agronomic effectiveness of TSP and 6 PR sources was evaluated in glasshouse conditions with oil palm seedlings for one year-period. The percentage of PR dissolution varied greatly among PR sources. The PR dissolution was assessed by 0.5 M NaOH, Pi strip, L-value and 1 M ammonium citrate-dissolved Ca. Irrespective of the methods used, the more reactive PR such as North Carolina and Tunisia dissolved more P than the lower reactive sources such as Christmas Island and China PR. All the four methods used gave positive correlation with plant P uptake, with 0.5M NaOH being the best indirect method for determining PR dissolution. Less than 30% of the applied P was dissolved during the one-year period, with only about 15 to 40% of the dissolved P being taken up by the oil palm seedlings. A laboratory 32 P isotopic exchange method was also carried out in this acid soil to assess the soil P status parameters. A low water soluble P concentration (Cp) was found for all PRs used. The ratio of the

  15. Donnan membrane speciation of Al, Fe, trace metals and REEs in coastal lowland acid sulfate soil-impacted drainage waters

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Adele M.; Xue, Youjia [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Kinsela, Andrew S. [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Institute for Environmental Research (IER), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234 (Australia); Wilcken, Klaus M. [Institute for Environmental Research (IER), Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234 (Australia); Collins, Richard N., E-mail: richard.collins@unsw.edu.au [School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052 (Australia)

    2016-03-15

    Donnan dialysis has been applied to forty filtered drainage waters collected from five coastal lowland acid sulfate soil (CLASS) catchments across north-eastern NSW, Australia. Despite having average pH values < 3.9, 78 and 58% of Al and total Fe, respectively, were present as neutral or negatively-charged species. Complementary isotope dilution experiments with {sup 55}Fe and {sup 26}Al demonstrated that only soluble (i.e. no colloidal) species were present. Trivalent rare earth elements (REEs) were also mainly present (> 70%) as negatively-charged complexes. In contrast, the speciation of the divalent trace metals Co, Mn, Ni and Zn was dominated by positively-charged complexes and was strongly correlated with the alkaline earth metals Ca and Mg. Thermodynamic equilibrium speciation calculations indicated that natural organic matter (NOM) complexes dominated Fe(III) speciation in agreement with that obtained by Donnan dialysis. In the case of Fe(II), however, the free cation was predicted to dominate under thermodynamic equilibrium, whilst our results indicated that Fe(II) was mainly present as neutral or negatively-charged complexes (most likely with sulfate). For all other divalent metals thermodynamic equilibrium speciation calculations agreed well with the Donnan dialysis results. The proportion of Al and REEs predicted to be negatively-charged was also grossly underestimated, relative to the experimental results, highlighting possible inaccuracies in the stability constants developed for these trivalent Me(SO{sub 4}){sub 2}{sup −} and/or Me–NOM complexes and difficulties in modeling complex environmental samples. These results will help improve metal mobility and toxicity models developed for CLASS-affected environments, and also demonstrate that Australian CLASS environments can discharge REEs at concentrations an order of magnitude greater than previously reported. - Highlights: • CLASS discharge large amounts of metals and their speciation is poorly

  16. Long term remediation of highly polluted acid mine drainage: A sustainable approach to restore the environmental quality of the Odiel river basin

    Energy Technology Data Exchange (ETDEWEB)

    Caraballo, Manuel A., E-mail: manuel.caraballo@dgeo.uhu.es [Geology Department, University of Huelva, Avenida 3 de Marzo s/n, Campus ' El Carmen' , E-21071 Huelva (Spain); Macias, Francisco [Geology Department, University of Huelva, Avenida 3 de Marzo s/n, Campus ' El Carmen' , E-21071 Huelva (Spain); Roetting, Tobias S. [Technical University of Catalonia (UPC), Hydrogeology Group, E-08034 Barcelona (Spain); Nieto, Jose Miguel [Geology Department, University of Huelva, Avenida 3 de Marzo s/n, Campus ' El Carmen' , E-21071 Huelva (Spain); Ayora, Carlos [Institute of Environmental Assessment and Water Research, IDAEA - CSIC, Jordi Girona 18, 08034 Barcelona (Spain)

    2011-12-15

    During 20 months of proper operation the full scale passive treatment in Mina Esperanza (SW Spain) produced around 100 mg/L of ferric iron in the aeration cascades, removing an average net acidity up to 1500 mg/L as CaCO{sub 3} and not having any significant clogging problem. Complete Al, As, Cd, Cr, Cu, Ti and V removal from the water was accomplished through almost the entire operation time while Fe removal ranged between 170 and 620 mg/L. The system operated at a mean inflow rate of 43 m{sup 3}/day achieving an acid load reduction of 597 g.(m{sup 2} day){sup -1}, more than 10 times higher than the generally accepted 40 g.(m{sup 2} day){sup -1} value commonly used as a passive treatment system designing criteria. The high performance achieved by the passive treatment system at Mina Esperanza demonstrates that this innovative treatment design is a simple, efficient and long lasting remediation option to treat highly polluted acid mine drainage. - Highlights: > Novel reactive mixture enable 20 month of high hydraulic conductivity. > Acid load reduction improved 10 times comparing to vertical flow wetland. > High biotic and abiotic iron oxidation and removal. > Complete Al, As, Cd, Cr, Cu, Ti and V water removal. - A high permeable alkaline reactive substrate offers a sustainable option to remediate severely polluted acid mine drainage in the Odiel basin

  17. Long term remediation of highly polluted acid mine drainage: A sustainable approach to restore the environmental quality of the Odiel river basin

    International Nuclear Information System (INIS)

    Caraballo, Manuel A.; Macias, Francisco; Roetting, Tobias S.; Nieto, Jose Miguel; Ayora, Carlos

    2011-01-01

    During 20 months of proper operation the full scale passive treatment in Mina Esperanza (SW Spain) produced around 100 mg/L of ferric iron in the aeration cascades, removing an average net acidity up to 1500 mg/L as CaCO 3 and not having any significant clogging problem. Complete Al, As, Cd, Cr, Cu, Ti and V removal from the water was accomplished through almost the entire operation time while Fe removal ranged between 170 and 620 mg/L. The system operated at a mean inflow rate of 43 m 3 /day achieving an acid load reduction of 597 g.(m 2 day) -1 , more than 10 times higher than the generally accepted 40 g.(m 2 day) -1 value commonly used as a passive treatment system designing criteria. The high performance achieved by the passive treatment system at Mina Esperanza demonstrates that this innovative treatment design is a simple, efficient and long lasting remediation option to treat highly polluted acid mine drainage. - Highlights: → Novel reactive mixture enable 20 month of high hydraulic conductivity. → Acid load reduction improved 10 times comparing to vertical flow wetland. → High biotic and abiotic iron oxidation and removal. → Complete Al, As, Cd, Cr, Cu, Ti and V water removal. - A high permeable alkaline reactive substrate offers a sustainable option to remediate severely polluted acid mine drainage in the Odiel basin

  18. Behavioural responses of indigenous benthic invertebrates (Echinogammarus meridionalis, Hydropsyche pellucidula and Choroterpes picteti) to a pulse of Acid Mine Drainage: A laboratorial study

    International Nuclear Information System (INIS)

    Macedo-Sousa, Joaquim A.; Gerhardt, Almut; Brett, Christopher M.A.; Nogueira, Antonio J.A.; Soares, Amadeu M.V.M.

    2008-01-01

    The drainage of abandoned mines leads to several ecological problems, particularly the acidification of surface freshwater systems and heavy metal contamination. In order to study the possibility of using the behavioural early warning responses of Portuguese indigenous benthic invertebrates to detect an acute short-term pulse of Acid Mine Drainage (AMD), experiments with the Multispecies Freshwater Biomonitor MFB TM were performed and locomotion and ventilation were measured as endpoints. AMD was collected from the 'Sao Domingos' mine (Southeast Portugal) and the following species were selected: Echinogammarus meridionalis (Pinkster, 1973), Hydropsyche pellucidula (Curtis, 1834) and Choroterpes picteti (Eaton, 1870). For simulating the pulsed exposure, AMD was added to river water where invertebrates were collected and pH was lowered until reaching 3.5. The effects of H + and heavy metals were discriminated using HCl positive controls. In addition to behaviour, mortality was registered. E. meridionalis was the most sensitive species in terms of mortality and behavioural endpoints, followed by C. picteti and H. pellucidula. E. meridionalis early warning responses consisted of increased locomotion with subsequent increase in ventilation, whereas for C. picteti only an increase in locomotion was observed. H. pellucidula showed no early warning responses. This work demonstrates the suitableness of using benthic invertebrates' behavioural early warning responses for detecting spikes of pollutants like AMD. - Behavioural responses of aquatic invertebrates may be used to detect spikes of Acid Mine Drainage

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

    Science.gov (United States)

    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.

  20. Acid drainages of the pyritic sterile from the Pocos de Caldas uranium mine: environmental interpretation and implications; Drenagens acidas do esteril piritoso da mina de uranio de Pocos de Caldas: interpretacao e implicacoes ambientais

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Vicente Paulo de

    1995-12-01

    Considering the planned closure of the first uranium mine and milling plant operating in Brazil, located in the Pocos de Caldas Plateau, in the State of Minas Gerais, in the next two years, there is the need to obtain basic information for its decommissioning. Special attention has been directed to the following critical areas: open pit, tailing, dam and waste rock piles, because these are the main sources of acid drainage generation. These waters cannot be allowed to flow in the external environment because in addition to sulphuric acid, there is a number of elements in concentration above those allowed by regulations. Among the waste piles (bota-foras BF) two of them BF-4 and BF-8, are in a process of acid generation, thus requiring more attention. The objective of this work was to simulate at the laboratory scale the oxidation and the reduction zones of BF-4. The experiments were conducted in acrylic columns, where the waste sample was kept under aerated and saturated conditions, in different columns. The control of the chemical (solubilized chemical species), physico-chemical (redox potential, pH, conductivity) and biological (bacterial activity) parameters has been carried out on the acid solutions generated by the chemical and biological reactions that occur at the waste. Although the results refer to a four month period, some relevant points can be highlighted, which will serve as a basis for further research. The mineralogical characterization identified the existence of other sulphides associated to pyrite with lower oxidation potential than the latter. The results obtained with the biological characterization for the two conditions studied revealed that the bacterial activity is more intense in the region in contact with air, than in saturated region. (author) 30 refs., 29 figs., 8 tabs.

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

    Science.gov (United States)

    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

  2. Oral tranexamic acid is equivalent to topical tranexamic acid without drainage in primary total hip arthroplasty: A double-blind randomized clinical trial.

    Science.gov (United States)

    Luo, Ze-Yu; Wang, Duan; Meng, Wei-Kun; Wang, Hao-Yang; Pan, Hui; Pei, Fu-Xing; Zhou, Zong-Ke

    2018-05-01

    To compare the efficacy of multiple doses of oral tranexamic acid (TXA) with topical TXA administration in reducing blood loss following total hip arthroplasty (THA). In this double-blinded trial, 117 patients undergoing primary THA were randomized to receive 2 g TXA orally 2 h preoperatively, and two doses of 1 g TXA postoperatively (oral group) or 3 g of TXA topical administration in the operating room (topical group). The primary outcome was a reduction in hemoglobin concentration. Other outcomes-such as blood loss, TXA-related cost (¥), length of hospital stay (days), complications such as pulmonary thromboembolism (PE), deep vein thrombosis (DVT), and infection, blood coagulation and fibrinolysis, and hip function-were recorded. The mean reduction in hemoglobin level was similar between the oral and topical groups (3.07 g/dL compared with 3.12 g/dL; p = 0.85). Similarly, there was no significant difference in the mean total blood loss between oral and topical administration (863 mL compared with 902 mL; p = 0.62). Three patients received an allogeneic blood transfusion, including one patient in the oral group and two patients in the topical group (p = 0.55). The oral group had a significantly lower TXA-related cost than the topical group: ¥944 and ¥4359, respectively (p = 0.01). No PE, DVT, cardiac infarction or renal failure occurred during the 90-day follow-up. The coagulation and fibrinolysis parameters were similar between the two groups. Oral TXA is equivalent to topical TXA administration in the reduction of blood loss in the setting of primary THA without drainage. Copyright © 2018. Published by Elsevier Ltd.

  3. The availability of second generation feedstocks for the treatment of acid mine drainage and to improve South Africa's bio-based economy.

    Science.gov (United States)

    Westensee, Dirk Karl; Rumbold, Karl; Harding, Kevin G; Sheridan, Craig M; van Dyk, Lizelle D; Simate, Geoffrey S; Postma, Ferdinand

    2018-10-01

    South Africa has a wide range of mining activities making mineral resources important economic commodities. However, the industry is responsible for several environmental impacts; one of which is acid mine drainage (AMD). Despite several years of research, attempts to prevent AMD generation have proven to be difficult. Therefore, treatment of the resulting drainage has been common practice over the years. One of the recommended treatment methods is the use of second generation feedstocks (lignocellulosic biomass). This biomass is also acknowledged to be an important feedstock for bio-refineries as it is abundant, has a high carbon content and is available at minimal cost. It can also potentially be converted to fermentable sugars (e.g. glucose) through different treatment steps, which could further yield other valuable commodities (cellulase, poly-β-hydroxybutyric acid (PHB) and penicillin V). It is estimated by a generic flowsheet model that 7 tons of grass biomass can produce 1400 kg of glucose which can subsequently produce 205 kg, 438 kg and 270 kg of cellulase, PHB and Penicillin V, respectively. In this paper we investigate the feasibility of grass as feedstock for AMD treatment and the subsequent conversion of this acid pre-treated grass into valuable bio-products. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Separation of Mn(II) in presence of Al(III) in acid drainage from an Uranium mine with the use of chelating resins

    International Nuclear Information System (INIS)

    Soares, Eliane Pavesi B.; Gomes, Viviane T.; Vaitsman, Delmo S.

    2011-01-01

    The acid drainage of Osamu Utsumi mine is the main environmental impact from mining activities in Pocos de Caldas - MG - Brazil. The water produced in this process is characterized by high acidity and heavy metal concentration. To minimize this environmental impact, new technologies directed towards treatment of acid drainage of mine (ADM) have been studied. However, due to the presence of Al 3+ (which has a high charge) in the ADM, these resins get quickly saturated, preventing stripping of divalent cations like Mn 2+ . This study proposes the synthesis of chelating resins that provide preferential retention of Mn 2+ instead of Al 3+ . It was synthesized resins functionalized with amidoxime and dithiocarbamate. The capacity of retention of Mn 2+ e Al 3+ ions at different pH values was assessed for each resin. The stripping of Mn 2+ at 2, 3 and 4 (pH ADM range) by studied resins was not preferential for Mn 2+ in relation to Al 3+ , probably due to the strong electrostatic interaction between this last type of high charge density and the active sites from extractor agents and resins. However at pH 6 (stated by environmental norms for liquid effluents discharge) the synthesized resins had a good retention capacity for Mn 2+ . So it is proposed that the extraction technique using chelating resins could be employed to strip Mn 2+ from ADM at pH 6,0, since at this condition , Al 3+ is precipitated as Al(OH) 3 . (author)

  5. Prediction of acid generation potential

    International Nuclear Information System (INIS)

    Nalbandyan, V.B.

    1992-01-01

    This paper discusses acid rock drainage (ARD), a term used to describe leachate, seepage, or drainage that has been affected by the natural oxidation of sulfide minerals contained in rock which is exposed to air and water. The principal ingredients for ARD formation are reactive sulfide minerals, oxygen, and water. The oxidation reactions responsible for the formation of ARD are often accelerated by biological activity. These reactions yield low pH (acidic) water that has the potential to mobilize heavy metals that may be contained in the geologic materials that are contacted. ARD can cause a detrimental impact on the quality of ground or surface water to which it discharges. ARD likely has been associated with mines since mining began. ARD is not necessarily confined to mining activities, but can occur naturally wherever sulfide-bearing rock is exposed to air and water. It is important to recognize that not all operations that expose sulfide-bearing rock will result in ARD

  6. Subsurface drainage

    CSIR Research Space (South Africa)

    Van Der

    1993-09-01

    Full Text Available and long term behavior were evaluated. Laboratory tests for geotextile selection are recommended and tentative criteria given. The use of fin drains was evaluated in the laboratory and a field study to monitor the efficacy of drainage systems was started...

  7. Use of radioactive 32P technique to study phosphate rock dissolution in acid soils

    International Nuclear Information System (INIS)

    Mahisarakul, J.; Mullins, G.L.; Chien, S.H.

    2002-01-01

    A laboratory experiment was conducted to evaluate the dissolution of six sources of phosphate rock in two acid soils (Ultisols): a sandy soil and a red clay soil. Labile P was determined using the radioactive 32 P technique for Pi extractable P and resin extractable P. Incubations were conducted for 0, 1, 2, 3, 4 and 5 weeks for 32 P exchangeable technique, 0 and 5 weeks for Pi technique and 5 weeks for resin technique. Rates of PR were 0 and 400 mgP/ha. The results showed that labile P in the sandy soil decreased from 0-1 weeks for all the PRs except Hahotoe PR and Hazara PR's. Between 1 and 5 weeks labile P remained relatively constant. The ranking of labile P from PRs was: North Carolina = Kouribga > Matam > Hahotoe = Hazara> Patos de Minas. In the red soil, labile P from all PRs appeared to be relatively unchanged during the 0-5 week incubation. Pi extractable P in sandy soil showed no significant differences due to incubation time. In the red clay soil, there was a significant decrease in Pi-P extracted from soil mixtures with PRs after 5 weeks as compared to 0 weeks. Results of the Resin-extractable P in both sandy and red soils were in agreement with labile P as measured by 32 P exchange technique. (author)

  8. Using environmental isotopes to characterize hydrologic processes of the Nelson Tunnel acid mine drainage site, West Willow Creek watershed, Creede, CO

    Science.gov (United States)

    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.

  9. Water - rock interaction in different rock environments

    International Nuclear Information System (INIS)

    Lamminen, S.

    1995-01-01

    The study assesses the groundwater geochemistry and geological environment of 44 study sites for radioactive waste disposal. Initially, the study sites were divided by rock type into 5 groups: (1) acid - intermediate rocks, (2) mafic - ultramafic rocks, (3) gabbros, amphibolites and gneisses that contain calc-silicate (skarn) rocks, (4) carbonates and (5) sandstones. Separate assessments are made of acid - intermediate plutonic rocks and of a subgroup that comprises migmatites, granite and mica gneiss. These all belong to the group of acid - intermediate rocks. Within the mafic -ultramafic rock group, a subgroup that comprises mafic - ultramafic plutonic rocks, serpentinites, mafic - ultramafic volcanic rocks and volcanic - sedimentary schists is also evaluated separately. Bedrock groundwaters are classified by their concentration of total dissolved solids as fresh, brackish, saline, strongly saline and brine-class groundwaters. (75 refs., 24 figs., 3 tabs.)

  10. Inorganic contaminants attenuation in acid mine drainage by fly ash and fly ash-ordinary Portland cement (OPC) blends : column experiments

    International Nuclear Information System (INIS)

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

    2010-01-01

    The infiltration of acid mine drainage (AMD) material into mine voids is one of the environmental impacts of underground coal mining. In this study, the mitigation of AMD in a mine void was simulated in laboratory conditions. Various mixtures of fly ash, solid residues, and Portland cement were added to packed columns over a 6-month period. The fly ash additions generated near-neutral to alkaline pH levels, which in turn induced precipitation, co-precipitation, and adsorption contaminant attenuation mechanisms. A modelling study demonstrated that the precipitation of ferrihydrite, Al-hydroxides, Al-oxyhydroxysulphates, gypsum, ettringite, manganite, and rhodochrosite lowered contaminant levels. Results of the study indicated that the pH regime and acidity level of the AMD strongly influenced both the leaching of the toxic trace elements as well as the attenuation of the AMD. 3 refs., 2 figs.

  11. Exploring plant factors for increasing phosphorus utilization from rock phosphates and native soil phosphates in acidic soils

    International Nuclear Information System (INIS)

    Feng Guanglin; Xiong Liming

    2002-01-01

    Six plant species with contrasting capacity in utilizing rock phosphates were compared with regard to their responses to phosphorus starvation in hydroponic cultures. Radish, buckwheat and oil rapeseed are known to have strong ability to use rock phosphates while ryegrass, wheat and sesbania are less efficient. Whereas other plants acidified their culture solution under P starvation (-P), radish plants make alkaline the solution. When neutralizing the pH of the solutions cultured with plants under either -P or + P conditions, solutions with P starved buckwheat, rapeseed, and radish had a higher ability to solubilize Al and Fe phosphates than did those cultured with sesbania, ryegrass and wheat. Characterization of organic ligands in the solutions identified that citrate and malate were the major organic anions exuded by rapeseed and radish. Besides citrate and malate, buckwheat exuded a large amount of tartrate under P starvation. In contrast, ryegrass, wheat and sesbania secreted only a limited amount of oxalic acid, regardless of P status. Changes in activities of phosphoenolpyruvate carboxylase, acid phosphatase, and nitrate reductase in these plants were also compared under P- sufficient or -deficient conditions. The results indicated that plant ability to use rock phosphates or soil phosphates is closely related to their responses toward P starvation. The diversity of P starvation responses was discussed in the context of co-evolution between plants and their environment. Approaches to use plant factors to enhance the effectiveness of rock phosphates were also discussed. (author)

  12. Radiological, chemical and morphological characterizations of phosphate rock and phosphogypsum from phosphoric acid factories in SW Spain

    Energy Technology Data Exchange (ETDEWEB)

    Renteria-Villalobos, Marusia, E-mail: marusia@us.es [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Departamento de Fisica Aplicada, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Advanced Materials Research Center (CIMAV), Miguel de Cervantes 120, 31109 Chihuahua (Mexico); Vioque, Ignacio, E-mail: ivioque@us.es [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Departamento de Fisica Aplicada, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Mantero, Juan, E-mail: manter@us.es [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Departamento de Fisica Aplicada, Avda. Reina Mercedes s/n, 41012 Seville (Spain); Manjon, Guillermo, E-mail: manjon@us.es [Applied Nuclear Physics Group, University of Seville, ETS Arquitectura, Departamento de Fisica Aplicada, Avda. Reina Mercedes s/n, 41012 Seville (Spain)

    2010-09-15

    In this work, radiological, chemical, and also morphological characterization was performed in phosphate rock and phosphogypsum samples, in order to understand the behavior of toxic elements. Characterization was carried out using X-ray diffraction (XRD), X-ray fluorescence (XRF), gamma spectrometry and scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). Our results show that the phosphate rock was mainly composed of fluorapatite, calcite, perovskite, quartz, magnetite, pyrite and kaolinite, whereas phosphogypsum only exhibited dihydrated calcium sulfate. The activity concentration of U-series radioisotopes in phosphate rock was around 1640 Bq/kg. {sup 226}Ra and {sup 210}Pb tend to be distributed into phosphogypsum by up to 80%, whereas the fraction of U-isotopes is 10%. The most abundant trace elements in phosphate rock were Sr, Cr, V, Zn, Y, Ni and Ba. Some elements, such as Ba, Cd, Cu, La, Pb, Se, Sr, Th and Y, were enriched in the phosphogypsum. This enrichment may be attributed to an additional input associated to the sulfuric acid used for the phosphoric acid production. Furthermore, results from SEM-EDX demonstrated that toxic elements are not distributed homogeneously into phosphogypsum. Most of these elements are concentrated in particles <20 {mu}m of high porosity, and could be easily mobilized by leaching and/or erosion.

  13. Radiological, chemical and morphological characterizations of phosphate rock and phosphogypsum from phosphoric acid factories in SW Spain

    International Nuclear Information System (INIS)

    Renteria-Villalobos, Marusia; Vioque, Ignacio; Mantero, Juan; Manjon, Guillermo

    2010-01-01

    In this work, radiological, chemical, and also morphological characterization was performed in phosphate rock and phosphogypsum samples, in order to understand the behavior of toxic elements. Characterization was carried out using X-ray diffraction (XRD), X-ray fluorescence (XRF), gamma spectrometry and scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX). Our results show that the phosphate rock was mainly composed of fluorapatite, calcite, perovskite, quartz, magnetite, pyrite and kaolinite, whereas phosphogypsum only exhibited dihydrated calcium sulfate. The activity concentration of U-series radioisotopes in phosphate rock was around 1640 Bq/kg. 226 Ra and 210 Pb tend to be distributed into phosphogypsum by up to 80%, whereas the fraction of U-isotopes is 10%. The most abundant trace elements in phosphate rock were Sr, Cr, V, Zn, Y, Ni and Ba. Some elements, such as Ba, Cd, Cu, La, Pb, Se, Sr, Th and Y, were enriched in the phosphogypsum. This enrichment may be attributed to an additional input associated to the sulfuric acid used for the phosphoric acid production. Furthermore, results from SEM-EDX demonstrated that toxic elements are not distributed homogeneously into phosphogypsum. Most of these elements are concentrated in particles <20 μm of high porosity, and could be easily mobilized by leaching and/or erosion.

  14. Influence of carbon source and inoculum type on anaerobic biomass adhesion on polyurethane foam in reactors fed with acid mine drainage.

    Science.gov (United States)

    Rodriguez, Renata P; Zaiat, Marcelo

    2011-04-01

    This paper analyzes the influence of carbon source and inoculum origin on the dynamics of biomass adhesion to an inert support in anaerobic reactors fed with acid mine drainage. Formic acid, lactic acid and ethanol were used as carbon sources. Two different inocula were evaluated: one taken from an UASB reactor and other from the sediment of a uranium mine. The values of average colonization rates and the maximum biomass concentration (C(max)) were inversely proportional to the number of carbon atoms in each substrate. The highest C(max) value (0.35 g TVS g(-1) foam) was observed with formic acid and anaerobic sludge as inoculum. Maximum colonization rates (v(max)) were strongly influenced by the type of inoculum when ethanol and lactic acid were used. For both carbon sources, the use of mine sediment as inoculum resulted in a v(max) of 0.013 g TVS g(-1) foam day(-1), whereas 0.024 g TVS g(-1) foam day(-1) was achieved with anaerobic sludge. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. 8,9-Epoxyeicosatrienoic acid analog protects pulmonary artery smooth muscle cells from apoptosis via ROCK pathway

    International Nuclear Information System (INIS)

    Ma, Jun; Zhang, Lei; Li, Shanshan; Liu, Shulin; Ma, Cui; Li, Weiyang; Falck, J.R.; Manthati, Vijay L.; Reddy, D. Sudarshan; Medhora, Meetha; Jacobs, Elizabeth R.; Zhu, Daling

    2010-01-01

    Epoxyeicosatrienoic acids (EETs), metabolites of arachidonic acid (AA) catalyzed by cytochrome P450 (CYP), have many essential biologic roles in the cardiovascular system including inhibition of apoptosis in cardiomyocytes. In the present study, we tested the potential of 8,9-EET and derivatives to protect pulmonary artery smooth muscle cells (PASMCs) from starvation induced apoptosis. We found 8,9-epoxy-eicos-11(Z)-enoic acid (8,9-EET analog (214)), but not 8,9-EET, increased cell viability, decreased activation of caspase-3 and caspase-9, and decreased TUNEL-positive cells or nuclear condensation induced by serum deprivation (SD) in PASMCs. These effects were reversed after blocking the Rho-kinase (ROCK) pathway with Y-27632 or HA-1077. Therefore, 8,9-EET analog (214) protects PASMC from serum deprivation-induced apoptosis, mediated at least in part via the ROCK pathway. Serum deprivation of PASMCs resulted in mitochondrial membrane depolarization, decreased expression of Bcl-2 and enhanced expression of Bax, all effects were reversed by 8,9-EET analog (214) in a ROCK dependent manner. Because 8,9-EET and not the 8,9-EET analog (214) protects pulmonary artery endothelial cells (PAECs), these observations suggest the potential to differentially promote apoptosis or survival with 8,9-EET or analogs in pulmonary arteries.

  16. 8,9-Epoxyeicosatrienoic acid analog protects pulmonary artery smooth muscle cells from apoptosis via ROCK pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jun; Zhang, Lei; Li, Shanshan [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, Heilongjiang 150081 (China); Liu, Shulin [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, Heilongjiang 150081 (China); Bio-pharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China); Ma, Cui [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, Heilongjiang 150081 (China); Li, Weiyang [Mudanjiang Medical College, Mudanjiang 157011 (China); Falck, J.R.; Manthati, Vijay L.; Reddy, D. Sudarshan [University of Texas Southwestern Medical Center, Dallas, TX 75390 (United States); Medhora, Meetha; Jacobs, Elizabeth R. [Division of Pulmonary and Critical Care, Department of Medicine, Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226 (United States); Zhu, Daling, E-mail: dalingz@yahoo.com [Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang District, Harbin, Heilongjiang 150081 (China); Bio-pharmaceutical Key Laboratory of Heilongjiang Province, Harbin 150081 (China)

    2010-08-15

    Epoxyeicosatrienoic acids (EETs), metabolites of arachidonic acid (AA) catalyzed by cytochrome P450 (CYP), have many essential biologic roles in the cardiovascular system including inhibition of apoptosis in cardiomyocytes. In the present study, we tested the potential of 8,9-EET and derivatives to protect pulmonary artery smooth muscle cells (PASMCs) from starvation induced apoptosis. We found 8,9-epoxy-eicos-11(Z)-enoic acid (8,9-EET analog (214)), but not 8,9-EET, increased cell viability, decreased activation of caspase-3 and caspase-9, and decreased TUNEL-positive cells or nuclear condensation induced by serum deprivation (SD) in PASMCs. These effects were reversed after blocking the Rho-kinase (ROCK) pathway with Y-27632 or HA-1077. Therefore, 8,9-EET analog (214) protects PASMC from serum deprivation-induced apoptosis, mediated at least in part via the ROCK pathway. Serum deprivation of PASMCs resulted in mitochondrial membrane depolarization, decreased expression of Bcl-2 and enhanced expression of Bax, all effects were reversed by 8,9-EET analog (214) in a ROCK dependent manner. Because 8,9-EET and not the 8,9-EET analog (214) protects pulmonary artery endothelial cells (PAECs), these observations suggest the potential to differentially promote apoptosis or survival with 8,9-EET or analogs in pulmonary arteries.

  17. Long term field evaluation of phosphate rock and superphosphate in acid soils of Hungary; Incubation and pot experiments

    International Nuclear Information System (INIS)

    Nemeth, T.; Osztoics, E.; Csatho, P.; Radimszky, L.; Baczo, G.Y.

    2002-01-01

    A series of experiments was conducted to compare the agronomic effectiveness of phosphate rock (from Algeria) and of single superphosphate (from Russia, Kola) on a moderately acidic pseudogley brown forest soil (Szentgyoergyvoelgy) and on a slightly acidic chernozem brown forest soil (Kompolt). Dynamics of water-soluble and ammonium lactate-soluble P-contents (AL-P) and soil pH-H 2 O changes were studied in a half-year long incubation experiment. A follow-up pot experiment with the same soils was carried out with winter rape as test plants. Both experiments were set up with similar P fertilizer sources and P rates (100, 200, and 400 mg mineral acid soluble P 2 O 5 per kg soil). At the beginning of incubation experiment, the water-soluble P content of the pseudogley brown forest soil was influenced by both the sources of P and the experimental conditions. The water-soluble P content decreased with time. After the 15 th to 20 th day of incubation, when the fast binding process of the water-soluble P ended, the effects of the P forms decreased. In this stage, the effects of environmental conditions depended on the form of the P fertilizer. The water-soluble P content of the phosphate rock-treated samples was affected to a great extent by soil water content, while the incubation temperature had a greater effect in soils treated with superphosphate. The AL-P content of soils was increased similarly by addition of equal rates of phosphate rock and super-phosphate at the beginning of incubation. The AL-P content of phosphate rock-treated soils was higher throughout the incubation period than of the superphosphate-treated soils -treated. Temperature had a greater effect on the AL-P content of soils than soil water content. As the AL-extraction may dissolve a substantial amount of the undecomposed phosphate rock, this method is not applicable to soil testing of available P forms from phosphate rock-treated soils. Initial soil pH decreased on average by 0.5 units in the

  18. Application of Potential Phosphate-Solubilizing Bacteria and Organic Acids on Phosphate Solubilization from Phosphate Rock in Aerobic Rice