What Causes Acid Rain ?

WHAT CAUSES ACID RAIN ?

ACID RAIN http://www.youtube.com/watch?v=893KB3s_jIA http://www.youtube.com/watch?v=-EEYGrtvRMo The primary causes of acid rain are sulfur dioxide and nitrogen oxides. Overloading the Nitrogen and Sulfur cycles causes acid rain. Each year, the U.S. discharges about 20 million tons of sulfur dioxide into the atmosphere. Two thirds of it discharged from power plants burning coal or oil. The rest is largely a byproduct of industrial boilers, smelters, and refineries. Volcanoes, fires, bacterial decomposition, lightening, and hot springs also release sulfur dioxide and nitrogen dioxide into the atmosphere, but human industrial activities account for 90% of the sulfur dioxide in the atmosphere. Twenty four million tons of nitrogen oxides are also released from vehicles, power plants, and industry in the U.S. annually. Power plants that burn fossil fuels also contribute significantly to nitrogen oxide emission.

Excess production of these substances was identified in the late 1960s as the cause of a growing environmental threat: acid rain. When combined with water vapor in the atmosphere nitrogen oxide and sulfur oxide are converted to nitric acid and sulfuric acid respectively. Days later, and often hundreds of miles from the source, these acids fall with rainwater.

Acid rain comes down to the earth in the form of rain, snow, hail, fog, frost, or dew.

Effects of acid rain

 Acid rain can destroy both natural ecosystems and manmade products like statues and building.

 Acid rain can damage trees and crops, and rendering lakes lifeless.

 Acid rain can make the lakes and ponds too acidic to support fish. But by the time the fish die, much of the food web that sustains them has been destroyed. Clams, snails, crayfish, and insect larvae die first, then amphibians, and finally fish. The result is a crystal clear lake- beautiful but dead

 Acid rain interferes with the growth and yield of many farm crops by leeching out essential nutrients such as calcium and potassium and killing decomposer organisms, thus preventing the return of nutrients to the soil. Plants poisoned and deprived of nutrients, become weak and vulnerable to infection and insect attack. High in the Green Mountains of Vermont, scientists have witnessed the death of about half of the red spruce and beech trees one-third of the sugar maples since 1965.

sugar maple

 At a monitoring station atop Mount Mitchell in North Carolina, the pH of fog has been recorded at 2.9, more acidic than vinegar.

 Acid deposition increases the exposure of organisms to toxic metals, including aluminum, led, mercury, and cadmium, which are far more soluble in acidified water than in water of neutral pH. Aluminum dissolved from rock may inhibit plant growth and killed fish. Drinking water in some households has been found to be dangerously contaminated with lead dissolved by acidic water from lead solder in old pipes. Fish in acidified water have been found to have dangerous levels of mercury in their bodies, which is subject to biological magnification as it is passed through trophic levels.

The limestone statue at Rheims Cathedral in France is being dissolved by acid deposition.

 Many scientific studies have identified a relationship between elevated levels of sulfur dioxide and nitrogen dioxide and increased illness and premature death from heart and lung disorders, such as asthma and bronchitis.

 Sulfates and nitrates that form in the atmosphere from sulfur dioxide

(SO2) and nitrogen oxides (NOx) emissions contribute to visibility impairment, meaning we cannot see as far or as clearly through the air. Sulfate particles account for 50 to 70 percent of the visibility reduction in the eastern part of the U.S., affecting our enjoyment of national parks, such as the Shenandoah and the Great Smoky Mountains.

 Acid rain and the dry deposition of acidic particles contribute to the corrosion of metals (such as bronze) and the deterioration of paint and stone (such as marble and limestone). These effects significantly reduce the societal value of buildings, bridges, cultural objects (such as statues, monuments, and tombstones), and cars. Dry deposition of acidic compounds can also dirty buildings and other structures, leading to increased maintenance costs. To reduce damage to automotive paint caused by acid rain and acidic dry deposition, some manufacturers use acid-resistant paints, at an average cost of $5 for each new vehicle (or a total of $61 million per year for all new cars and trucks sold in the U.S.). Prevention of acid rain  One side of prevention is government environmental regulations, to limit the quantity of emissions released into the atmosphere. To follow these regulations, industries can add “scrubbers” to their smoke stacks to reduce the amount of sulfur released. Another option is washing the coal before it is burned, which reduces the amount of sulfur in the coal. To reduce the amount of car exhaust pollution, catalytic converters can be used in vehicles to make the exhaust less harmless.  Reduce coal and use and increase the use of natural gas and renewable resources.  If the need to burn coal is still necessary then the using a a low- sulfur coal would be an alternative.

 On a personal level, there are many things you can do to help prevent acid rain. Try to use your car as little possible: walk, use public transportation, and carpool turn the heat down in your house, and don’t use air conditioning (these things require more gas burning). Conserve water by running a washing machine or dishwasher only with a full load. And remember to turn off lights, and use energy efficient lightbulbs! By following these tips, you will reduce the emissions of fossil fuels by using less energy.

 Along with these prevention methods, clean up needs to take place on the areas where acid rain has already caused damage.

 Add lime to acidified lakes to neutralize the water.  Instead of driving by yourself , you should carpool like these

dudes.

In the U.S., amendments to the Clean Air Act in 1900 have resulted in substantial reductions in emissions of both sulfur dioxide and nitrogen oxides from power plants. Air quality and rain acidity has improved in some regions. However nitrogen oxide emissions remain high, primarily because more gasoline is being burned by automobiles. Damaged ecosystems recover very slowly. Many freshwater ecosystems in New York’s Adirondack Mountains continue to grow more acidic. Many scientists believe that considerable additional reduction in emissions will be needed to allow the recovery of damaged ecosystems. http://www.authorstream.com/Presentation/aSGuest2119-101404-acid-rain- consequences-air-pollution-rains-science-technology-ppt-powerpoint/

For High School PPT on acid rain http://www.slideshare.net/guest6d3ed48/acid-rain-powerpoint-presentation

For APES students PPT on acid rain.

PPT ON ACID RAIN SIMPLE ONE