While coal provides an affordable and easily accessible form of fuel for electricity generation, there are severe environmental, human health and economic effects of coal. The combustion of coal contributes more pollution than any other type of fossil fuel. Fifty percent of all U.S. electricity comes from coal combustion. Just one 500-megawatt coal-fired power plant produces about 3 million tons of carbon dioxide per year. Using this much coal for electricity generation causes environmental problems such as acid rain, land pollution, and global climate change. Coal has also been linked to increased incidence of respiratory ailments such as asthma, shortness of breath, and chest pains. Finally, remediating the damage done by coal combustion can cost thousands to millions of dollars.
The first major environmental problem associated with coal combustion is acid rain. This occurs when nitrogen oxides and sulfur oxides produced in burning coal are released into the atmosphere. These oxides then react with atmospheric moisture to produce dilute acids such as sulfuric acid, nitrous acid, and nitric acid. Dry particles can fall to Earth's surface as precipitation, as well. This is referred to as acid deposition or dry deposition. When these particles interact with clouds, the resulting rain events can have a lower pH than normal. The pH of normal rain is slightly acidic, usually between pH 5-6; however acid rain can have a pH as low as pH 2.
This can decrease the pH of water bodies, thus changing the aquatic chemistry, killing plants, fish, and other aquatic organisms. Because most freshwater lakes and ponds do not have high buffering capacities, small additions of acid have significant impacts. Acid rain can also cause the number of forest species to decline. This happens for a variety of reasons. First, acid rain can harm the leaves, bark, and seeds of trees, thus hindering both individual growth and community regeneration. Acid deposition can also affect root growth and impair nutrient uptake. Finally, years of prolonged exposure to acid rain can acidify the soil, thus leaching nutrients and releasing harmful miner als that may have been bound in the cation and anion exchange capacities.
Acid deposition and acid rain can fall upon buildings and monuments, reacting with building materials such as marble, concrete, and iron. In the United States, damages caused by acid deposition are estimated to be around $10 billion each year. Industrialized nations such as most of Europe, Russia, North America, and China are subject to the majority of effects of acid deposition and acid rain.
Land use and land-based pollution issues are the second problem created by the heavy use of coal for electricity production. The mountaintop removal method, for example, causes irreparable damage to the landscape. Once the topsoil and other soil horizons are removed, usually only the bedrock or other impermeable surfaces remain. In these areas, vegetation cannot grow, so erosion from water and wind usually carries away any remaining soil.
Also, abandoned mines can fill with water and then drain throughout the topography into nearby streams and valleys, creating acid mine drainage problems. This situation occurs when rainwater permeates the iron-sulfide-laden materials deep within subsurface mines and in mine waste. The water and iron sulfide react, creating sulfuric acid. Acid mine drainage can occur in most places where coal or metals have been mined. This is because carbon and metal compounds usually occur as sulfides. Acid mine drainage can quickly reduce the pH of an affected water body, devastating local fish, waterfowl, and plants in the watershed. Intense, or chronic, rain events can lead to highly-acidic conditions into a watershed.
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Your Alternative Fuel Solution for Saving Money, Reducing Oil Dependency, and Helping the Planet. Ethanol is an alternative to gasoline. The use of ethanol has been demonstrated to reduce greenhouse emissions slightly as compared to gasoline. Through this ebook, you are going to learn what you will need to know why choosing an alternative fuel may benefit you and your future.