Friday, June 10, 2011

4.11 Gas Pollution

Understand the biological consequences of pollution of air by sulfur dioxide and by carbon monoxide.

Sulfur Dioxide (major air pollutant & has impacts upon human health)
Chemical symbol:  SO2 (gas).
Produced when fuels that contain sulfur compounds burn. So this includes crude oil, & coal - fossil fuels eg:    in industrial processes.
                 + by vehicles.
                 + volcanoes.    

                 (example) Sulfur Dioxide Pie Chart.

 Local environmental effects
Sulphur dioxide is toxic to a variety of plant life & may produce visible signs of injury & reduce yields of certain crops.
The acid condition in eg: lakes results in the making of aluminum ions which clog up the fish gills enabling them to get oxygen.  Resulting in the fish to die.

Global Environmental Effect:
Sulfur dioxide gas dissolves in the water droplets in clouds causing the rain to be more acidic. It can then  be transported thousands of kilometers dispersing pollution in the atmosphere. Acid rain affects the natural balance of rivers, lakes and soils, resulting in damage to wildlife and vegetation being burnt.

Sulfuric Acid:  Chemical symbol: H2SO4
It is a strong mineral acid. The salts of sulfuric acid are called sulfates. Sulfuric acid is soluble in water at all concentrations.

Effects on Soils:
Trees/Plants take their nutrition from Calcium, Magnesium, & Potassium ions from the soil. 
With Acid Rain deposition, Hydrogen ions displace these important nutrients ^^ in a process called leaching. Leaching: means that the ions are washed out of the top soil. Resulting in the plant not being able to grow. 

Carbon Monoxide (pollution) : chemical symbol: CO
Produced: when an incomplete combustion occurs. 

Incomplete Combustion --> occurs when the supply of oxygen is poor. Water is still produced, but carbon monoxide and carbon are produced instead of carbon dioxide.

hydrocarbon + oxygen    →    carbon monoxide + carbon + water "

Human Effect: Toxic ---> Death.
Carbon Monoxide combines with hemoglobin inside the red blood cell, and forms a molecule called Carbanmino hemoglobin.


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