What are the 3 causing sources of acid mine drainage?
Acid mine drainage is the formation and movement of highly acidic water rich in heavy metals. This acidic water forms through the chemical reaction of surface water (rainwater, snowmelt, pond water) and shallow subsurface water with rocks that contain sulfur-bearing minerals, resulting in sulfuric acid.
How acidic is 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 is the main reason for acid mine drainage?
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 are the 2 main ways that acid mine drainage treated?
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 does acid mine drainage affect water quality?
Water Pollution: Acid Mine Drainage Acid mine drainage impacts stream and river ecosystems by increasing acidity, depleting oxygen, and releasing heavy metals such as aluminum (Al3+), iron (Fe3+), manganese (Mn2+), and zinc (Zn2+).
How can we prevent acid mine drainage?
The most prevalent method for treating AMD contamination is the addition of alkaline reagents such as lime, limestone, sodium carbonate or sodium hydroxide. This treatment aims at neutralizing acidic water and the precipitation of heavy metals.
What is the impact of acid mine drainage on the environment?
Environmental and Human Impacts The most immediate and serious impacts of acid mine drainage are on natural waterways. High levels of dissolved metals may kill off all of the resident fish and aquatic life. Migratory creatures not resident to mining sites are also affected.
What is the impact on the environment of acid mine drainage during mining?
What is the current standard treatment for acid mine drainage contaminated water?
“Currently, the standard treatment for AMD is to aerate the water to oxidise the iron and add lime to bring the pH up. The iron then precipitates out – and most heavy metals along with it – in a deep red colour.
What is acid mine drainage?
Acid mine drainage can change the color of a stream into red or orange. Mine drainage refers to any surface water or groundwater that drains from an active or abandoned mining operation.
What does the USGS do to help manage mine drainage?
The USGS helps track the sources of acidic mine drainage and helps land managers develop better mitigation strategies. Acid mine drainage can change the color of a stream into red or orange.
How is mine drainage measured in the field?
Because the chemistry of water samples can rapidly change if removed from the mine, many mine drainage measurements are made in the field. The first measurement typically looks at acidity, which is reported as pH. A neutral pH has a value of 7. Any sample that reads below a pH of 7 is characterized as being acidic.
How polluted is mine drainage?
Polluted mine drainage can be extremely acidic and is often laden with high concentrations of toxic, heavy metals. In general, the more acidic the water, the more likely it is to be harmful to living organisms.