Impacts of the Acid Mine Drainage on the Temperature and Acidity - Example

IMPACTS OF THE ACID MINE DRAINAGE ON THE TEMPERATURE, ACIDITY, IRON(III) HYDROXIDE AND METAL CONTAMINATION ABSTRACT Acid mine drainage may take place in nature via rock weathering process or during broad mechanical earth interruption like construction, transportation passageways, subdividing, deep excavation, coal mining, metal mining and others. Acid mine drainage can form from both surface and underground sites when the sulphide-bearing minerals in rock are exposed to water and air, thereby transforming the sulphide to sulphuric acid. Acid Mine Drainage is affecting the temperature and acidity when the FeS2 mineral pyrite oxidized. Another effect of the acid mine drainage is when its pH is raised beyond 3 either through contact with fresh water or neutralizing minerals, previously soluble Iron(III) ions precipitate as Iron (III) hydroxide. Semi-metal and trace metal contaminations afftects all levels of biological organization such as the molecular, subcellular, cellular, individual, population, community and ecosystem-level responses. To address these adverse effects, active and passive treatments are being done. It was found through long years of battling with this acid mine drainage that a more efficient and effective treatment need to be developed and implemented. Acid Mine Drainage and its Sources Acid mine drainage (AMD) is a phenomenon that occurs naturally in the environment as part of the rock weathering process. The process of chemical weathering takes place as minerals in rocks are chemically changed and eventually decompose. Intensifying rainfall hastens the chemical weathering of minerals in rocks. The speed up effect of the rain on the weathering process is because of water which is an important factor of this natural process. Another weathering process factor that also speed up the chemical reaction that causes decomposition of minerals is temperature. Hence, tropical climates have more weathered soils, buildings and landforms. However, in places where there is large-scale disturbance of the earth, outflow of acidic water the coal mines, metal mines, coal stocks, coal handling facilities, coal washeries, waste rock piles, tailing piles, coal waste tips, open pits, ponds, underground tunnels, underground workings, open pit mine faces, waste rock dumps, tailings deposits, ore stockpiles and the like happen (Lapakko, 1988). This occurs in transportation corridors, construction sites, subdivisions, coal sites, mining sites, deep excavation activities and other large activitieswithin rocks containing an abundance of sulfide minerals. AMD can form from both surface and underground mines. To illustrate the effects of mining on rainfall, please refer to Figure 1 below. Figure 1. Effects of Mining on the Rainfall Drainage Source: UNEP/GRID-Arendal AMD happens when the sulphide-bearing minerals in rock are exposed to water and air. The reactions would change the sulphide to sulphuric acid. AMD can progress at the various phases throughout the mining process. AMD refers to the acidic water with pH Read More