Constructed wetlands for treating acid mine drainage. The ideal neutralization first combines one of the reactants with previously precipitated solids. Amd is recognized as one of the most serious environmental problem in the. Prediction of water quality at surface mine sites pdf format acid mine drainage abatement projects. May 17, 2016 the first step in the acid mine drainage flowsheet is decarbonation. Many different types of acid water treatment systems have been developed over the past 30 years to combat this problem. Unfortunately, they tolerate only low metal concentrations or acidity loads, because they are prone to passivation loss of reactivity due to coating andor clogging loss of permeability by precipitates. Hydrated lime is the most commonly used chemical for treating amd and is used to treat more than 90% of the acid mine drainage worldwide.
Passive treatment of acidmine drainage virginia tech. The applications include mine drainage water from underground mines, intrusion water in open pit mines and excess water from tailing storage facilities. Most water remediation techniques are timely and costly, and amd can continue over a period of many years, therefore requiring treatment of amd to continue until well after the land has been abandoned by mining activities. Acid mine drainage prediction compares acid rock drainage factors of waste rock piles and tailings impoundments. Skousen and others published acid mine drainage treatment systems.
Research efforts have proceeded recently through the acid drainage technology initiative. 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 document, initially drafted in 2009, was reevaluated and. Amd causes severe environmental impacts, particularly on soil. A northeast acid mine drainage amd treatment facility was using calcium hydroxide lime to. Acid mine drainage sometimes forms when certain minerals in the soil and rocks around mines are exposed to weathering processes during mining. Treating acid mine drainage from abandoned mines in.
These exposed minerals release their contents into creeks causing them to become acidic. 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. As such, it is critical that chemical usage be optimized. Acid mine water drainage debating a sustainable solution to a.
Acid mine drainage will continue to be a problem in the future and treatment technologies will be important for everything from the health of the stream and. This guidance document provides the framework for the acid mine drainage and. This paper describes acid mine drainage amd generation and its associated technical issues. Acid mine drainage amd is currently the main pollutant of surface water in the midatlantic region. Handbook of technologies for avoidance and remediation of acid mine drainage. Pdf acid mine drainage control and treatment researchgate.
It also addresses metal leaching caused by sulphide mineral oxidation. Passive treatment of acidmine drainage vtechworks virginia. This is a natural chemical reaction which can proceed. As this mine water reaches the surface it comes into contact with the air. Understanding mine water treatment mine water, acid mine drainage and ochre as coal mining in the uk has reduced, some arrangements to pump water out of the mines have stopped. The first step in the acid mine drainage flowsheet is decarbonation. The gard guide deals with the prediction, prevention and management of drainage produced from sulphide mineral oxidation, often termed acid rock drainage ard. Above a ferrous iron concentration of 50100 mgl, limestone treatment does not appear applicable. 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. Coal mine drainage prediction and pollution prevention in pennsylvania. 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.
The formation of acid mine drainage and the contaminants associated with it have been described as the largest environmental problem facing the u. Acid mine drainage the center for rural pennsylvania. 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. Typically, with acid mine water, there is a high amount of co 2 in the waste stream.
It occurs when water flows over or through sulfurbearing materials, such as the pyritic rocks uncovered by the large earth movements involved in mining. 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. These products react with host rock and surface and groundwater to create a range of water chemistries from ph 2 to 8 and elevated ion concentrations. This acid leaches out metals in the rock, which can enter nearby. This paper focusses on the description of reliable, safe and economical treatment of mine water from different types of mines and applications by advanced membrane systems. Acid mine drainage research acid mine drainage amd has been the subject of intensive research since the 1960s. Acid mine drainage will continue to be a problem in the future and treatment technologies will be important for everything from the health of the stream and wildlife in it, to human health of those near that water. As amd is recognized as one of the more serious environmental problems in the mining industry, its causes, prediction and treatment have become the focus of a number of research initiatives commissioned by governments, the mining industry, universities and research establishments, with additional. Passive treatment of acid mine drainage with high metal. 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.
The acid mine drainage waste is characterized by red water. Alkalinity can result from hydroxyl ions oh, carbonate, silicate. Acid mine drainage overview acid rock drainage ard is produced by the oxidation of sulfide minerals, chiefly iron pyrite or iron disulfide fes2. Acid mine drainage amd is a major problem all over the world, especially where coal and gold mine activities are common. Contents 20180327 220 acid mine drainage formation problems associated with acid mine drainage treatment methods neutralization neutralization with polishing treatment sulfide precipitation conclusions. Acid mine drainage amd has been considered one of the industries toughest problems to solve. Passive treatment methods for acid water in pennsylvania. Treating acid mine drainage from abandoned mines in remote areas. This has allowed iron, found in the rocks within mine workings, to mix with underground water. Acid mine drainage treatment westech engineering, inc. Of the eight chemicals used most frequently, cost varies widely table 1, skousen et al. As a result, the water becomes very acidic and damages downstream aquatic ecosystems. Acid mine drainage amd is an environmental pollutant that impairs water resources in mining regions throughout the world. Amd treatment costs can have a significant impact on the.
Mine water treatment solutions for discharge and reuse. The major areas of research on amd are prediction of amd and preventionmitigation. As this discussion demonstrates, the appropriate treatment chemical can depend on both the oxidation state and concentrations of metals in the amd u. Acid mine drainage is a natural consequence of mining activity where the excavation of mineral deposits metal bearing or coal, below the natural groundwater level, exposes sulphur containing compounds to oxygen. The acid mine drainage setaside program implementation guidelines pdf establish uniform procedures to ensure the amd set aside program is implemented in a scientifically sound and cost effective manner in order to maximize the stream miles restored with the funds available. The gard guide is intended as a stateoftheart summary of the best practices and technology to assist mine. Chemical treatment of acid mine drainage anna gulkova, water and environmental engineering, aalto university 1. Always consider source control, closure of subsidence holes, mine sealing. Acid mine water drainage debating a sustainable solution. Once amd is generated, it is difficult to control the process and the treatment also requires high cost aguiar et al. In mining areas with high concentrations of pollutants. All of the limestone processes described are applicable to the low iron acid mine drainage situation. Amd is caused when water flows over or through sulfurbearing materials forming solutions of net acidity.
Residents left in dark over acid mine drainage treatment. Innovative treatment technologies notice this document was prepared by a national network of environmental management studies grantee under a fellowship from the u. Effective treatment options for acid mine drainage in the. Usps acid mine drainage program is a successful, cost effective solution turnkey program reduced chemical expenses, solids, and energy costs. Treated water running into a lake at a acid mine drainage plant near krugersdorp. Acid mine drainage abatement and treatment plans odnr mineral. The south african human rights commission acknowledges mariette liefferink and eugene viljoen for providing the photographs that appear in this booklet. Amd comes mainly from abandoned coal mines and currently active mining. Most water remediation techniques are timely and costly, and amd can continue over a period of many years, therefore requiring treatment of amd to continue until well after the. Where such treatment is required legally, treatment must be efficient. In some regions, it is the most common form of stream and river pollution. Nov, 2019 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.
Detailed laboratory investigations should follow to study the recovery of various byproducts, to develop a treatment process flowsheet and to. Acid mine drainage oxidation of pyritic materials during and after mining produces sulfuric acid and metal ions. This report presents the results of two grant projects on acid mine drainage remediation, sponsored by the center for rural pennsylvania. In many cases, chemical consumption is the number one operating cost of an acid mine drainage treatment system.
Acid mine drainage solutions for the mineral industry. Effective treatment options for acid mine drainage in the coal. Acid mine drainage amd is the flow, or seepage, of polluted water from old mining areas. Acid mine drainage amd has been a detrimental byproduct of coal mining for many. Treatment methods are commonly divided into either. Overview of acid mine drainage treatment with chemicals. Reference guide to treatment technologies for mining. Acid mine drainage prevention and control options nural kuyucak golder associates ltd.
The following is an overview of information on some major. Review of passive systems for acid mine drainage treatment. The agency notes that this report may be revised periodically without public notice. Acid mine drainage will continue to be a problem in the future and treatment. Expanded beds, tumblers and pulverized limestone systems are applicable to ferric iron acid mine drainage situations. Where such treatment is required legally, treatment must be efficient and continual. 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.
Chemical treatment of acid mine drainage vesiyhdistys. Techniques to correct and prevent acid mine drainage. This kind of pollution damages aquatic life and makes the water useless or harmful for others who depend on it for recreation or drinking water. Acid mine drainage, environmental effects, treatment.
Acid rain and acid mine drainage have polluted thousands of miles of pennsylvania streams with acid water. Skousen and others published acid mine drainage control and treatment find, read and cite all the research you need on. Acid mine drainage report1 acid mine drainage amd is the primary source of surface water pollution in the midatlantic region, and affects over 10,000 miles of streams across the country. However, the presence of bacteria will shorten the reaction time down to 8 minutes brick 1998. Existing treatment technologies for mine drainage are generally poorly documented and not readily available. The simplest treatment is neutralization and clarification. Pdf acid mine drainage treatment with chemicals jeff. Turner and a team of researchers with the department of biology at clarion university, evaluated passive treatment systems for their effectiveness. 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. A better organization centralized and exchange of information could greatly improve and guide future advances in the development of better and less.