- Method one – Physical treatment. Physical treatment of acidic waters uses artificial waterfalls to add turbulence into the water coming out of the mine.
- Method two – Chemical treatment. Acidic discharge from mines is often treated using common alkali chemicals such as limestone, quicklime, caustic soda or soda ash.
- Method three – Biological treatment. There are various options for using microorganisms to oxidise metals, especially iron, into insoluble oxides.
How can acid mine drainage be treated?
What to do?
- Find an acid stream by using litmus paper to measure the pH.
- Collect the water in bottles.
- Add one natural material to each bottle. Measure the initial pH.
- Label each bottle and write down its pH.
- Every few days for about two weeks, measure the pH to see what happens in each bottle. Write down the results.
What are the effects of acid - mine drainage?
Substances
- Calcium Compounds
- Oxides
- Soil
- Soil Pollutants
- Phosphorus
- Magnesium Oxide
- lime
What is acid mine drainage caused by?
Mine drainage is formed when pyrite (an iron sulfide) is exposed and reacts with air and water to form sulfuric acid and dissolved iron. Some or all of this iron can precipitate to form the red, orange, or yellow sediments in the bottom of streams containing mine drainage. The acid runoff further dissolves heavy metals such as copper, lead, and mercury into groundwater or surface water.
Will the project create acid mine drainage?
The process will collect acid mine drainage from the Northern and Central Appalachian Coal Basin, treat it to meet clean water standards and harvest the rare earth elements and the critical minerals cobalt and manganese. Acid mine drainage treatment plants would feed the resulting concentrates into a central facility.
What is being done to solve acid mine drainage?
Some common methods include: Reclamation of contaminated land by (1) adding lime or other alkaline materials to neutralize the acidity, and (2) adding uncontaminated top soil, planting vegetation, and modifying slopes to stabilize the soil and reduce infiltration of surface water into underlying contaminated material.
How long will acid mine drainage continue?
At some mines, acidic drainage is detected within 2–5 years after mining begins, whereas at other mines, it is not detected for several decades. In addition, acidic drainage may be generated for decades or centuries after it is first detected.
Is acid mine drainage regulated in the US?
Acid mine drainage is considered nonpoint source pollution, which is pollution from several separated sources, such as precipitation, atmospheric deposition, and land runoff. As such, the drainage is regulated by the federal government through mine site cleanup projects.
What chemicals are involved in developing acid mine drainage?
Mine drainage is formed when pyrite (an iron sulfide) is exposed and reacts with air and water to form sulfuric acid and dissolved iron. Some or all of this iron can precipitate to form the red, orange, or yellow sediments in the bottom of streams containing mine drainage.
What would the steps be to restore a surface mine?
Reclamation includes the following steps: contouring of land; placement of topsoil or an approved substitute on the graded area; reseeding with native vegetation, crops and/or trees; and years of careful monitoring to assure success.
What is the pH of acid mine drainage?
The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common.
What laws prevent mining issues such as acid drainage and the displacement of tailings?
What laws prevent mining issues such as acid drainage and the displacement of tailings? Mining Law of 1872 and the Surface Mining Control and Reclamation Act of 1977.
Why do environmentalists oppose the mining of Antarctic mineral resources?
Why do environmentalists oppose the mining of Antarctic mineral resources? The demand for minerals is expected to decline as the world's nations become more industrialized. The Antarctic environment is fragile and extremely vulnerable to the disturbance that would accompany development.
How is AMD formed?
Acid mine drainage (AMD) is the runoff produced when water comes in contact with exposed rocks containing sulfur-bearing minerals that react with water and air to form sulfuric acid and dissolved iron. This acidic run-off dissolves heavy metals including copper, lead, and mercury which pollute ground and surface water.
What is AMD in environmental science?
What is Acid Mine Drainage (AMD)? AMD is a term used to describe drainage flowing from or caused by surface mining, deep mining or coal refuse piles that are typically highly acidic with elevated levels of dissolved metals. Formation of acid mine drainage.
How does AMD affect the environment?
AMD is the biggest environmental challenge ever which impacts negatively on the quality of water resources (both ground and surface) and plays a role in flooding and decanting. AMD can lead to instability in the geology of an area and can destroy ecosystems and heritage sites.
Which useful products can be produced from AMD?
Desalinating acid mine water produces useful by-productsacid mine drainage.JoJo Tanks.plastic water tanks.South Africa water.water scarcity.water tanks.
What are passive treatments?
There are also less expensive methods known as ( passive treatments ) that can help improve our rivers and streams. Passive treatment methods are used most often for treating pollution from abandoned mines (prior to SMRA-1977) but the methods are used in other situations as well.
How to find the pH of an acid stream?
Find an acid stream by using litmus paper to measure the pH. Collect the water in bottles. Add one natural material to each bottle. Measure the initial pH. Label each bottle and write down its pH. Every few days for about two weeks, measure the pH to see what happens in each bottle. Write down the results.
Why is acid mine drainage bad?
Acid mine drainage poses severe environmental pollution problems due to its high acidity, toxic metals and sulphate contents. In this review, the available prevention of acid mine drainage generation, treatment options and their importance in light of the future perspectives are briefly discussed. The possible resources to be recovered such as ...
What is the most promising technology for reducing effluent discharge?
Application of membrane process is the most promising technologies to reduce effluent discharge, and minimize water requirement through wastewater reclamation ( Liu et al., 2011 ). AMD treatment using membrane technology is not common due to the relatively high cost of the membrane and high membrane fouling due to the susceptibility of membrane systems to low pH of AMD; however, application of nanofiltration (NF) and reverse osmosis (RO) processes for AMD treatment recently attracted more researchers due to their high capacity of salt and metal retention. In recent study, high membrane fouling and risk of performance failure was reduced by pre-treatment of AMD using sand filtration equipped by rice husk-ash and coal fly-ash adsorbent columns followed by ultrafiltration (UF) and RO ( Nasir et al., 2016 ). The pre-treatment increased the final pH permeate of RO in the range of 6.0–6.8, and also removed 98.00, 94.11, and 95.8% sulphate, iron, and Mn, respectively. Furthermore, the small-scale AMD plant was capable of producing high quality of permeate and met the environmental standard.
How does AMD affect the environment?
The generated AMD water elevates the level of dissolved metal in the receiving surface water stream and negatively affects the stream biota. The degree of environmental pollution by AMD is dependent on its composition and pH, which in turn may vary depending on the geology of the mine sites or sources.
What are the natural resources used for AMD?
There are many naturally available resources which have been tested for AMD treatment and found to be effective such as crushed seashell, lignite , attapulgite, zeolite and bentonite . In addition to their effectiveness, the application of these naturally available resources aid to decrease the cost of treatment. For example, AMD has been treated using crushed seashells as an efficient and cost-effective adsorption medium in batch and column studies ( Masukume et al., 2014 ). Seashell is a hard material in which the main constituent is calcium carbonate and it can be crushed to small pieces for increased capacity to adsorb trace metals. The results of AMD treatment by means of crushed seashell revealed that the seashell-derived adsorbent has great potential as an alternative low-cost material in such treatment.
What are the resources that can be recovered from mining?
The possible resources to be recovered such as ferric hydroxide, ferrite, rare earth metals, sulphur and sulphuric acid and their economic benefit are discussed. Furthermore, the importance of mine tailing for stabilisation of contaminated soil and production of building materials are highlighted.
Can you remove Zn and Mn at pH 6?
For example, metals such as Zn and Mn are not easily removed at lower pH < 6, therefore, passive treatment in which limestone drains is used, is not the method of choice for the removal of high concentration of Zn and Mn.
Is SRB a good treatment for AMD?
Biological passive treatment using SRB has recently emerged as one of the most promising alternative technologies for AMD remediation. The feasibility of passive treatment options is evaluated on the basis of the capacity of a particular system to produce the required alkalinity and the removal capacity of dissolved metals ( Kalin et al., 2006 ). A number of experimental tests approved SRB as an effective AMD treatment option and have been reported by several researchers ( Bai et al., 2013, Castillo et al., 2012, Clyde et al., 2016, Deng et al., 2016, Hao et al., 2014, Johnson, 2014, Kieu et al., 2011, Sahinkaya et al., 2015, Zhang and Wang, 2016, Zhang and Wang, 2014 ). The utilisation of SRB for the remediation of industrial sulphate containing sewage and sulphur contaminated groundwater and their environmental preferences with regard to bioreactors on different operational parameters has recently been reviewed by Hao et al. (2014). The review summarised the advantage of SRB over the conventional method of wastewater treatment in sulphur bioconversion systems for simultaneous removal of carbon and toxic trace metals existing in industrial wastewater. Furthermore, the utilisation of SRB results in minimal biological sludge production and greenhouse gas emission relative to conventional carbon cycle based treatment technologies.