Tsukamoto, T. K., & Miller, G. C. (1999). Methanol as a Carbon Source for Microbiological Treatment of Acid Mine Drainage. Water Res., 33(6), 1365–1370.
Abstract: Sulfate reducing passive bioreactors are increasingly being used to remove metals and raise the pH of acidic waste streams from abandoned mines. These systems commonly use a variety of organic substrates (i.e. manure, wood chips) for sulfate reduction. The effectiveness of these systems decreases as easily accessible reducing equivalents are consumed in the substrate through microbial activity. Using column studies at room temperature (23-26 degrees C), we investigated the addition of lactate and methanol to a depleted manure substrate as a method to reactivate a bioreactor that had lost >95% of sulfate reduction activity. A preliminary experiment compared sulfate removal in gravity fed, flow through bioreactors in which similar masses of each substrate were added to the influent solution. Addition of 148 mg/l lactate resulted in a 69% reduction in sulfate concentration from 300 to 92 mg/l, while addition of 144 mg/l methanol resulted in an 88% reduction in sulfate concentration from 300 to 36 mg/l. Because methanol was found to be an effective sulfate reducing substrate, it was chosen for further experiments due to its inherent physical properties (cost, low freezing point and low viscosity liquid) that make it a superior substrate for remote, high elevation sites where freezing temperatures would hamper the use of aqueous solutions. In these column studies, water containing sulfate and ferrous iron was gravity-fed through the bioreactor columns, along with predetermined methanol concentrations containing reducing equivalents to remove 54% of the sulfate. Following an acclimation period for the columns, sulfate concentrations were reduced from of 900 mg/l in the influent to 454 mg/l in the effluent, that reflects a 93% efficiency of electrons from the donor to the terminal electron acceptor. Iron concentrations were reduced from 100 to 2 mg/l and the pH increased nearly 2 units. (C) 1999 Elsevier Science Ltd.
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Sibrell, P. L. (2000). ARD remediation with limestone in a CO2 pressurized reactor. ICARD 2000, Vols I and II, Proceedings, , 1017–1026.
Abstract: We evaluated a new process for remediation of acid rock drainage (ARD). The process treats ARD with intermittently fluidized beds of granular limestone maintained within a continuous now reactor pressurized with CO2. Tests were performed over a thirty day period at the Toby Creek mine drainage treatment plant, Elk County, Pennsylvania in cooperation with the Pennsylvania Department of Environmental Protection. Equipment performance was established at operating pressures of 0, 34, 82, and 117 kPa using an ARD flow of 227 L/min. The ARD had the following characteristics: pH, 3.1; temperature, 10 OC; dissolved oxygen, 6.4 mg/L; acidity, 260 mg/L; total iron, 21 mg/L; aluminum, 22 mg/L; manganese, 7.5 mg/L; and conductivity, 1400 muS/cm. In all cases tested, processed ARD was net alkaline with mean pH and alkalinities of 6.7 and 59 mg/L at a CO2 pressure of 0 kPa, 6.6 and 158 mg/L at 34 kPa, 7.4 and 240 mg/L at 82 kPa, and 7.4 and 290 mg/L at 117 kPa. Processed ARD alkalinities were correlated to the settled bed depth (p <0.001) and CO2 pressure (p <0.001). Iron, aluminum, and manganese removal efficiencies of 96%, 99%, and 5%, respectively, were achieved with filtration following treatment. No indications of metal hydroxide precipitation or armoring of the limestone were observed. The surplus alkalinity established at 82 kPa was successful in treating an equivalent of 1136 L/min (five-fold dilution) of the combined three ARD streams entering the Toby Creek Plant. This side-stream capability provides savings in treatment unit scale as well as flexibility in treatment effect. The capability of the system to handle higher influent acidity was tested by elevating the acidity to 5000 mg/L with sulfuric acid. Net alkaline effluent was produced, indicating applicability of the process to highly acidic ARD.
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Ciftci, H., & Akcil, A. (2006). Asidik maden drenajinin (AMD) giderilmesinde uygulanan biyolojik yontemler. Biological methods applied in the treatment of acid mine drainage (AMD). Madencilik = The = Journal of the Chamber of Mining Engineers of Turkey, 45(1), 35–45.
Abstract: Acidic mine drainage (AMD) is a serious environmental problem in mining areas throughout the world. AMD occurs as a result of the natural oxidation of sulfide minerals when they are exposed to oxygen and water during their disposal and storage at the mining areas. Because it includes low pH and high concentrations of dissolved metals and sulphates, AMD can potentially damage to the environment. If the formation of AMD can't be prevented and controlled, it must be collected and treated to remove acidity and reduce the concentration of heavy metals and suspended solids before its release to the environment. Different types of microorganisms in the treatment of AMD can play a very important role in the development and the application of microbiological prevention, control and treatment technologies. The purpose of this article is to give information about the passive biological methods used in the treatment and the control of AMD and the role of microorganisms in these methods.
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Bennett, J. W., & Lawton, M. D. (1995). Assessment of the Rum Jungle strategy for acid mine drainage control. Bewertung der Sanierungsstrategie von Rum Jungle zur Beherrschung des Problems der Freisetzung saurer Grubenwässer. In Second Australian Acid Mine Drainage Workshop, Charters Towers, AU, 28 31 March 1995 (pp. 179–190).
Abstract: Das 1971 stillgelegte Uran- und Kupferbergwerk Rum Jungle kontaminierte durch aus dem Bergbau, der Aufbereitung und der Haufenlaugung resultierende saure Grubenwässer das Grundwasser und die Vorfluter. Die von 1983 bis 1986 durchgeführten Sanierungsarbeiten werden ausführlich unter Angabe der zeitlichen Veränderung der Meßwerte für den Schadstoffaustrag beschrieben. Das anschließend (bis 1993) realisierte Monitoringprogramm (mit staatlich gestützten Forschungsaktivitäten) zeigte, daß die Sanierung erfolgreich abgeschlossen worden war und alle Anforderungen erfüllte. Gegenwärtig ist ein neues Forschungsprogramm für weitere 5 Jahre angelaufen, bei dem es vorrangig darum geht, eine Quantifizierung der Schadstoffgenerierungsmengen und der Schadstoffbelastung zu erreichen sowie die Transportmechanismen zu untersuchen.
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Parker, G., Noller, B., & Waite, T. D. (1999). Assessment of the use of fast-weathering silicate minerals to buffer AMD in surface waters in tropical Australia. In D. E. Goldsack, N. Belzile, P. Yearwood, & G. J. Hall (Eds.), Sudbury '99; Mining and the environment II; Conference proceedings.
Abstract: Surface waters in the Pine Creek Geosyncline (located in Australia's “Top End”, defined as the area of Australia north of 15 degrees S) are characterized by their low carbonate buffering capacity. These waters are buffered by silicate weathering and hence are slightly acidic, ranging in pH from 4.0 to 6.0. The Pine Creek Geosyncline contains most of the Top Ends' economic mineral deposits and characteristically shows no correlation between carbonate minerals and sulfidic orebodies hosting gold deposits (unlike uranium deposits). Thus many gold mines do not have ready access to carbonate minerals for buffering acid mine drainage (AMD). It is possible that locally available fast-weathering silicate minerals may be used to buffer AMD seeps. The buffering intensity of silicate minerals exceeds that of carbonate minerals, but their slow dissolution kinetics has ensured that these materials have received little attention in treating AMD. In addition, carbonate mineral dissolution is retarded when contacted with intense AMD solutions due to the formation of surface coatings of iron minerals. The lower pH range of silicate mineral dissolution may prevent the formation of such coatings. The Pine Creek Geosyncline consists of a complex geochemistry, and a number of fast-weathering silicate minerals have been noted in various areas. The difficulty in assessing such minerals for use in buffering AMD is the lack of kinetic data available under conditions prevalent AMD (i.e., low pH solutions saturated with aluminium and silica). This study sets out to evaluate the applicability of using such minerals to treat AMD surface seeps.
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