Innovative treatment technologies october 2003 prepared by. Acid mine drainage amd forms when sulfide minerals, particularly pyrite and marcasite, have been exposed to oxidizing conditions during mining and other excavation. Acid mine drainage amd can result when the mining process exposes mine wastes, tailings, or workings which contain quantities of reactive sulphides. When the rocks made of sulfur are excavated from a mine surface or an underground mine, they react with water and oxygen to form sulfuric acid. The sulfide minerals oxidize in the presence of water and oxygen to form acidic, sulfaterich drainage. Enhanced immobilization of arsenic from acid mine drainage.
Acidic mining lakes acid mine drainage, limnology and. This will provide a framework upon which decision makers, acting as either mine staff or regulators may quickly determine which method should be adopted to address the issue of acid mine drainage. Article views are the countercompliant sum of full text article downloads since november 2008 both pdf and html across all institutions and individuals. This is a natural chemical reaction which can proceed when minerals are exposed to air and water. You can see from equation 1 that in order for these reactions to happen, the pyrite must be exposed to both air and mining is one of south africas most important industries, but it comes with a cost. Using macroinvertebrates to assess ecological integrity of. Fundamentals of minedrainage formation and chemistry. When uranium ores are mined, the ores are crushed into a powdery substance, thus increasing surface area to easily extract uranium. Guideline document for monitoring acid mine drainage. Studies assessing stream restoration of acid mine drainage amd usually use community metrics that emphasize only a few attributes of ecological integrity. The geochemistry of acid mine drainage request pdf. Bioremediation of acid mine drainage using sulfatereducing bacteria list of tables table 1. Introduction manganese is a common component of both neutral and acid mine drainage. So, to better understand amd and ard, lets begin by defining some terms like ph the standard measure of acidity.
Acid mine drainage amd has been a detrimental byproduct of coal mining for many years. Releases of amd have low ph, high specific conductivity, high. Certain southern west virginia drainages which are not acidic contain more than the maximum allowable. Seasonal patterns of recovery evident in the fall after the summer treatment season reverted in the next spring after overwinter periods when sources were not captured. Bioremediation of acid mine drainage using sulfate. Pure neutral water has a ph of 7, acids have a ph less than 7 and. Acid mine drainage project lab chemistry libretexts. Thus, this study applied some simple testing methods to the. Mine drainage waters in scandinavia and the united kingdom are of three main types. Acid mine drainage overview acid rock drainage ard is produced by the oxidation of sulfide minerals, chiefly iron pyrite or iron disulfide fes2.
Bioremediation of acid mine drainage using sulfatereducing bacteria pdf 72 pp, 1. Amd is caused when water flows over or through sulfurbearing materials forming solutions of net acidity. We used a variety of measures to examine recovery of macroinvertebrate communities in a watershed receiving passive treatment for amd. Acid mine drainage amd is a typical source of environmental pollution ascribing to its characteristics of high acidity and heavy metal content. This springerbrief focuses on acid mine drainage amd in the three basins in the witwatersrand, south africa. View acid mine drainage research papers on academia. Acid mine drainage prediction compares acid rock drainage factors of waste rock piles and tailings impoundments.
Acid mine drainage amd forms when sulfide m inerals are exposed to oxidizing conditions in coal and metal mining, highway construction, and other largescale excavations. The drainage chemistry of areas in which these minerals have the ability to neutralize acid differs sharply from that of areas in which they do not. The ratedetermining step in the oxidation of iron pyrite and the formation of acidity in streams associated with coal and copper mines is the oxidation of ferrous iron. Acid mine drainage may form within mine wastes tailings and rock dumps that are impacted with surface water or in underground workings groundwater, and its production can continue long after. The ph scale actually measures hydrogen ion concentration in water solutions. To model the effect of carbonate minerals on drainage chemistry, we continue our calculations from the previous task in which we reacted pyrite with a hypothetical groundwater in contact with. It describes how to predict, prevent, and remediate the environmental impact of acid drainage and the oxidation of sulfides, offering the latest. Lovett department of chemistry west virginia university morgantown, wv 26506 i. Handbook for constructed wetlands receiving acid mine drainage. Techniques to correct and prevent acid mine drainage. Summary of passive treatment technologiespg 3 table 2.
Define acid mine drainage constructed wetlands as passive treatment systems acid tolerant aquatic plants benhar ironstone mine spoil in central scotland. Uranium acid mine drainage refers to acidic water released from a uranium mining site using processes like underground mining and insitu leaching. Underground, the ores are not as reactive due to isolation from atmospheric oxygen and water. Acid mine drainage research acid mine drainage amd has been the subject of intensive research since the 1960s.
Effect of phospholipid on pyrite oxidation and microbial. Acid mine drainage amd is produced when sulfidebearing material is exposed to oxygen and water. Both arsenite and arsenate forms coexist in many mine drainage localities, with the latter oxidation state more. Students set up experiments that mimic the process of metal sulfide mineral oxidative dissolution. Drainage flowing from or caused by mining that is typically highly acidic with elevated metal levels increased concentrations of cadmium, nickel, lead. This report aims to identify abandoned mine sites that utilize innovative technologies to treat mine drainage or contaminated soils and to put that information into a database. At present, acid mine drainage continues to pose a potential problem in some areas, despite improved prediction and prevention techniques. Characterization of mine waste rocks and prediction of acid mine drainage amd play an important role in preventing amd. Removal of manganese from acid mine drainage raymond j. These metrics are regularly updated to reflect usage leading up to the last few days. In examining this table, it is important to note that diffusion of oxygen into water is slow and, therefore, oxidation of iron sulfide is inhibited until the water level drops, which can occur periodically or seasonally in some cases. Currently, most strategies for amd treatment merely focus on metal removal rather than metal recovery. Sulfide oxidation, the mechanism for acid drainage, is a portion of that important sulphur chemistry that is an abundant source of energy to microbes and is also a major biochemical reaction in the changing geochemistry on earth.
An international workshop was held in september 1995 at the department for inland water research of the ufzcentre for environmental research. This laboratory project uses the context of acid mine drainage to teach concepts important to analytical chemistry and quantitative analysis. The chemistry of oxidation of pyrites, the production of. Arsenic release from mine waste occurs after oxidative dissolution of sulphide minerals. Despite these severe risks, predicting amd properties of mine wastes is typically not an. However, bioelectrochemical system bes is a promising technology to simultaneously remove and recover metal ions from amd. When mine and mine waste drainage have neutral ph, with a high concentration of dissolved metals, they are called neutral or alkaline mine drainage lottermoser, 2010. Due to geochemical similarity between arsenic and sulphur, polymetallic sulphide deposits and pyritearsenopyritebearing coal beds often contain exceptionally high concentrations of arsenic. Years of high flow resulted in degraded biological status when acid mine drainage capture was incomplete and metal loading had increased with runoff.
Arsenic geochemistry of acid mine drainage springerlink. Exposure of these reactive sulphides to oxygen and water may result in acid generation. Although hightech analytical methods have been highlighted for mineral characterization and quantification, simple testing methods are still practical ways to perform in a field laboratory in mines. This acid drainage, commonly referred to as acid mine drainage amd, has become an economic and environmental burden.
We also acknowledge previous national science foundation support under grant numbers 1246120, 1525057. Acid mine drainage in south africa development actors. Acid rock drainage as a concern and part of all metals and mining operations. Amd comes mainly from abandoned coal mines and currently active mining. Case study of acid mine drainage amd and remediation.
Characterization of mine waste and acid mine drainage. Acidification is a universal problem at all mining sites in which oxygenated water comes in contact with sulfide minerals or other reduced sulfur compounds. Acid mine drainage amd is produced when minerals such as pyrite fes 2, pyrrhotite fe 1x s, chalcopyrite cufes 2 and marcasite fes 2 are exposed to oxygen and water valente and gomes, 2009. Current methods for the remediation of acid mine drainage. Acid mine drainage, acid and metalliferous drainage amd, or acid rock drainage ard is the outflow of acidic water from metal mines or coal mines acid rock drainage occurs naturally within some environments as part of the rock weathering process but is exacerbated by largescale earth disturbances characteristic of mining and other large construction activities, usually within rocks. Wheal jane pptp, water chemistry for entire system, 20002002pg 15. The south african government and nongovernmental organizations response to amd is assessed, as well the socioeconomic and developmental effects of amd. Effective pollution abatement necessitates control ling this reaction. Acid mine drainage amd is currently the main pollutant of surface water in the midatlantic region. Yellow creek 2b bioreactor, water chemistry pg 11 table 3.
The role of acidophilic protozoa and other indigenous microflora. Hydraulic conductivity and selfhealing performance of. Contaminative mine drainage waters have become one of the major hydrogeological and geochemical problems arising from mankinds intrusion into the geosphere. Provides the tools needed to analyze and solve acid drainage problems featuring contributions from leading experts in science and engineering, this book explores the complex biogeochemistry of acid mine drainage, rock drainage, and acid sulfate soils. Scavenging of as from acid mine drainage by schwertmannite. Schwertmannite formation was favored at ph 34, but its structure was degraded at high as levels. The effect of phospholipid on the biogeochemistry of pyrite oxidation, which leads to acid mine drainage amd chemistry in the environment, was investigated.
Acid mine drainage, rock drainage, and acid sulfate soils. Consequences of failing to predict amd for individual operations and for the mining industry include unplanned spending on remedial measures and reputational damage. It provides a background to amd and its impactsfrom a social science perspective. Metagenomic analyses were carried out to understand how the microbial community structure, which developed during the oxidation of pyritecontaining coal mining overburdenwaste rock owr, was affected by the presence of adsorbed. A series of coprecipitates were therefore prepared from mixed iron arsenatesulfate solutions to define the limits of schwertmannite stability. Ard is often mislabelled amd or acid mine drainage too.
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