Bioremediation of acid mine drainage using sulfatereducing bacteria pdf 72 pp, 1. The ph scale actually measures hydrogen ion concentration in water solutions. An example of acid mine drainage flowing into shamokin. Recovery of rare earth elements rees from coal mine. The south african human rights commission acknowledges mariette liefferink and eugene viljoen for providing the photographs that appear in this booklet. Acid mine drainage amd is the flow, or seepage, of polluted water from old mining areas. These sulfates dissolve in water forming sulfuric acid which then leaches heavy metals from rock exposed by mining. Treated water running into a lake at a acid mine drainage plant near krugersdorp. There are four chemical reactions that represent the chemistry of pyrite weathering to form acid mine drainage. Some mine drainage has been seen to have ph in the 2. The chemicals allow copper minerals to rise to the top and stick to. Development of an ree recovery industry around pre and postlaw mines will incentivize capture of these drainage sources, treatment of amd and discharge of.
This is a natural chemical reaction which can proceed. Acid mine drainage is the acidic water that is produced in mining areas from the oxidation of pyrite. Evaluation of the efficacy of acid mine drainage abatement measures is difficult even empirical analytical data may not reflect the actual measure of success of a mitigative endeavor. Handbook for constructed wetlands receiving acid mine drainage. Acid mine drainage can be released anywhere on the mine where sulfides are exposed to air and water including waste rock piles, tailings, open pits, underground tunnels, and leach pads. Prevention of acid mine drainage generation from open. Treatment of acidic coal mine drainage with ver7cal flow ponds. Acid mine drainage amd is a problem occurring across the globe, including in southeastern ohio. In order to achieve the usage of mining waste and to reduce the discharges to the environment, we have developed acid water treatment systems that allow recovering byproducts that can provide an added economic value, called phased treatment.
Lovett department of chemistry west virginia university morgantown, wv 26506 i. In pennsylvania, reported aluminum concentrations in discharge samples from 140 abandoned coal mines showed that over. Acid mine drainage and human rights south african human. In some regions, it is the most common form of stream and river pollution. How does acid mine drainage impact on human rights. The following is an overview of information on some major. 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.
Acid mine drainage effects, types, plants, marine, oxygen. Acid mine drainage amd refers to the outflow of acidic water from a mining site. This was achieved by the determination of some physicochemical properties and anion abundance in the water, the investigation of some heavy metal levels in the water and sediments, and the potential risks of sediment bound heavy metals to biota. Mine acid drainage mad is the runoff produced when water comes into contact with exposed rocks containing sulfurbearing minerals that react with water and air to form sulfuric acid, dissolved fe and al, and other chemical elements blowes et al. Acid mine drainage is a major problem with many hardrock mines, including almost all.
Acid metalliferous mine drainage management abbreviations and definitions acronym term definition determination unit aba by sobek the acid base accounting test was developed in 1974 to evaluate coal mine waste and was modified et al. Acid mine drainage prevention and control options nural kuyucak golder associates ltd. Amd comes mainly from abandoned coal mines and currently active mining. In the eastern united states alone, amd from coal mines has adversely impacted fisheries associated with over,000 kilometers 8,000 miles of streams in pennsylvania, west virginia, ohio, and maryland. Acid mine drainage solutions for the mineral industry. The life cycle of acid mine drainage copper ore from arizona concentrating ground up rock is mixed with water, air bubbles and small amounts of chemicals. Acid mine drainage amd is currently the main pollutant of surface water in the midatlantic region.
Acid drainage is often marked by yellow boy, an orangeyellow substance visible in the photo on this page that occurs when the ph of acidic mine. Chemical reaction of pyrite with water and oxygen forms sulfuric acid and dissolved iron. This is a natural chemical reaction which can proceed when minerals are exposed to air and water. Acid mine drainage mines built as early as the 1800s were developed in a manner which utilized gravity drainage, to avoid excessive water accumulation in the mines as a result, water polluted by acid, iron, sulfur and aluminum drained away from the mines and into streams results of acid mine drainage. Fact sheet acid mine drainage the problem the formation of acid mine drainage and the contaminants associated with it have been described as the largest environmental problem facing the u. This occurs along outcrops or scree slopes where sulfidebearing rock is naturally weathered. Its oxidation occurs spontaneously in nature, causing environmental problems like acid mine drainage amd and mine tailing leachate containing heavy metals. So, to better understand amd and ard, lets begin by defining some terms like ph the standard measure of acidity.
Prevention of acid mine drainage generation from openpit highwallsfinal report mine waste technology program activity iii, project 26 by. Pdf acid mine drainage management in indonesian mines. By far the most common mine drainage problem is that of acid mine drainage amd. The objective of this phd research was to investigate the leaching of acid clays with acid mine rock drainages amdard typically found in u. The ph of amd is usually in the range of 26, but mine impacted waters at circumneutral ph 58 are also common. Jun 17, 2016 what is acid mine drainage amd, why is it such a serious threat to south africa and more importantly why has been it been silenced and kept under wraps by the mining industry and south african government for so long. Sulfuric acid is produced when water interacts with sulfurbearing materials in the presence of oxygen and common bacteria 1.
Sources of acid mine drainage at the company are from the oxidation of water and oxygen on the wall of rock at pit, water. Environmental assessment of acid mine drainage pollution. Major environmental incidents caused by acid mine drainage. When the acid forming materials of a surface or underground mine are completely flooded, the acid production tends to cease. This included sites where effluent limits were not being met for any established parameter, not just ph alkalinity. The major areas of research on amd are prediction of amd and preventionmitigation.
Treatment of acidic coal mine drainage with ver7cal flow. Another waterquality parameter that is useful for characterizing water quality of acid mine drainage. Mariette is the ceo of the federation for a sustainable environment and was a member of the sahrc section 05 committee on human rights and acid mine drainage. Prevention of acid mine drainage generation from openpit. Acid mine drainage is an extensively documented environmental issue, commonly originated by the weathering of sulfide ores both in active and abandoned mining sites. Acid mine drainage an overview sciencedirect topics. Acid mine drainage biofilm this biofilm sequencing project was designed to explore the distribution and diversity of metabolic pathways in acidophilic biofilms e.
Acid base accounting is a test to assess the potential of a material to. Acid mine drainage is the second most important source of stream impairment in the appalachian basin. This requires sampling of the waste rock zones and submitting the samples for a series of tests. What can be done to prevent or clean up acid mine drainage. Mcsurdy department of energy pittsburgh research center p. Amd is caused when water flows over or through sulfurbearing materials forming solutions of net acidity. A study of environmental assessment of acid mine drainage. Acid mine drainage amd may form in underground workings groundwaters of deep mines, although this is generally of minor importance when a mine is in active production and water tables are kept artificially low by pumping. Another waterquality parameter that is useful for characterizing water quality of acid mine drainage is specific conductance.
Acid rock drainage and acid mine drainage acid rock drainage ard is a natural process in which sulfuric acid is produced when sulfides in rocksfor example, pyrite fes 2 are exposed to air and water. The iron in the water stream is in soluble form known as ferrous iron fe2. Acid mine drainage overview acid rock drainage ard is produced by the oxidation of sulfide minerals, chiefly iron pyrite or iron disulfide fes2. Author links open overlay panel ilhwan park a carlito baltazar tabelin b sanghee jeon a xinlong li a kensuke seno a mayumi ito b naoki hiroyoshi b. Acid mine drainage prediction compares acid rock drainage factors of waste rock piles and tailings impoundments. Pdf acid mine drainage amd occurs after mining exposes metal sulfides. Acid mine drainage amd consists of metalladen 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. Acid rock drainage as a concern and part of all metals and mining operations. An example of acid mine drainage flowing into shamokin creek. Acid mine drainage amd is typically characterized by low ph and high dissolved iron. Residents left in dark over acid mine drainage treatment.
An example of an extreme case is a tin mine in england that was mined by the romans more than 2,000 years ago and it still produces amd from pyrite oxidation. Wieder 1992 documents that the mechanism and efficiency of amd treatment varies. Amd is a problem now because of the increasing numbers of closed mines and the eventual closure of whole coalfields. This lesson covers the basic chemistry behind amd and the remediation processes, as. 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. The tools were used to estimate postcleanup water quality in two streamscement creek and mineral creek impacted by abandoned mines in colorado. Acid mine drainage research began prior to this century gleason 1976. A bench scale evaluation of organic substrates for use in constructed wetlands for the treatment of acid mine drainage 1991 197432284. Timothy bernard residents left in dark over acid mine drainage treatment. Acid mine drainage coal combustion products program. Effects of acid mine drainage on the release of aluminum. I acid mine drainage the generation of acid mine drainage amd and its discharge into the environment surrounding abandoned mines is likely to cause serious environmental pollution.
Pdf acid mine drainage control and treatment researchgate. The water then transports the contaminated mine materials to nearby rivers before eventually depositing the materials downstream. How acid mine drainage has affected the greater susquehanna. Handson experiments to test for acid mine drainage dr. As a result, the water becomes very acidic and damages downstream aquatic ecosystems.
Acid mine drainage is caused by both abandoned mines and mines in current excavation. Pdf acid mine drainage formation, control and treatment. The sulfuric acid causes leaching of iron, manganese, lead, copper, zinc and cadmium from the rock it interacts with. Jul 11, 20 process of acid mine drainage geochemical and microbial reactions during weathering of sulfide minerals pyrite in coal, refuse, or mine overburden oxidation of sulfide minerals in the presence of air, water, and bacteria formation of sulfuric acid and increase in acidity solubilization of metals due to low ph 5. Acid mine drainage causes, consequences and remediation. Geological survey usgs scientists were shown to be effective for evaluating strategies to reduce acid mine drainage in streams. The problem and the cleanup acid mine drainage is a global problem. Acid mine drainage results when surface and ground water combine with sulfuric rock from the mines, causing a sulfuric acid.
Recovery of rare earth elements rees from coal mine drainage. Water flowing through active or abandoned mine sites can become polluted by the material being mined 1. Pure neutral water has a ph of 7, acids have a ph less than 7 and. Ferrous or soluble iron is the first pollutant associated with acid mine drainage as it starts to make streams too acidic to support aquatic life figure 1. Acid mine drainage amd occurs when mining operations result in sulfide bearing ores, such as pyrite and chalcopyrite, being exposed to oxygen and water.
Media in category acid mine drainage the following 51 files are in this category, out of 51 total. A northeast acid mine drainage amd treatment facility was using calcium hydroxide lime to precipitate iron from the mine pool water. Acid mine drainage in lower salem, oh tej gautam, petroleum engineering and geology, marietta college summary acid mine drainage problem is very common in coal mining areas. Research efforts have proceeded recently through the acid drainage technology initiative. Ard is often mislabelled amd or acid mine drainage too. Acid mine drainage environmental notes on mining, updated september 2009 pyrite fes2 is commonly associated with coal and metal ore deposits. In a nutshell, acid mine drainage is a form of water pollution that happens when rain, runoff, or streams come in contact with rock that is rich in sulfur. In most cases, this acid comes primarily from oxidation of iron sulfide fes2, also known as pyrite or fools gold, which is often found in conjunction with valuable metals. Removal of manganese from acid mine drainage raymond j. 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. Introduction a previous study 1 revealed that the acid mine drainage amd phenomenon occurs in the old ngwenya mine, swaziland. Development of an ree recovery industry around pre and postlaw mines will incentivize capture of these drainage sources, treatment of amd and discharge of clean water.
The acid mine drainage amd inventory included all sites where water quality was a concern to the inspector. To assess the risk of acid and metalliferous mine drainage amd, most new mining projects require an initial assessment of the locations and volumes of potentially acid forming paf waste that is likely to be moved and dumped in waste stockpiles. Certain southern west virginia drainages which are not acidic contain more than the maximum allowable. Over time, sulfides react with oxygen and oxidise to form sulfates. In addition to low ph and high acidity, acid mine drainage from metal mines often contains dissolved heavy metals in toxic concentrations table 1. The acid mine drainage may also contain high amounts of co2 which forms carbonic acid and further depresses the ph. Acid mine drainage research acid mine drainage amd has been the subject of intensive research since the 1960s. Acid mine drainage biofilm metagenomics ncbi bookshelf. Introduction manganese is a common component of both neutral and acid mine drainage. Premine prediction of acid mine drainage springerlink. Acid mine drainage amd forms when sulfide minerals are exposed to. Acid mine drainage from coal and mineral mining operations is a difficult and costly.
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