1. ACID PRECIPITATION movie

2. ACIDS & BASES  Acid – loses a H + when dissolved in H 2 O organic (contain C) e.g. amino acids or acetic acid (CH 3 COOH) organic (contain C) e.g. amino acids or acetic acid (CH 3 COOH) inorganic like HCl or H 2 SO 4 inorganic like HCl or H 2 SO 4  Base – releases OH - when dissolved in water eg. NaOH or NaHCO 3 eg. NaOH or NaHCO 3  amount of acidity is measured on pH scale  low pH (< 7) indicates acidity  high pH (> 7) indicates alkalinity (basic)  pH of 7 is neutral

3. Deposition  source: pollution associated with burning of fossil fuels; leads to acid deposition.  Wet Deposition - acids with a pH below 5.6 are removed from the atmosphere in the form of rain, snow, sleet, and mist.  Dry Deposition - particles such as volcanic ash, sulphates, and nitrates are deposited onto a surface and then converted into acids when they contact water.

4. Acid Deposition

5. Sulphur dioxide (SO 2 )  sulphur from coal burning power plants is the greatest amount of SO 2 entering the atmosphere  need to reduce sulphur emissions  best way: conserve energy or use alternative sources

6. 3 ways to reduce sulphur emissions from coal-fired plants: 1. Wash the sulphur from the coal before combustion 2. Wash the sulphur from the smoke before it leaves the smokestacks 3. Remove the sulphur after combustion by using scrubbers - sprays a mixture of water and limestone (basic) into the smokestack

7. Nitrogen Oxides (NO X )  from vehicle emissions and burning coal  catalytic converters on vehicles help to reduce the emissions of carbon monoxide, hydrocarbons, and the nitrogen oxides  ON vehicles have to pass an emissions test every two years Movie

8. Govt. policies  Canada-Wide Acid Rain strategy: implemented in 1991 implemented in 1991 targeted reduction by 50% in most provinces targeted reduction by 50% in most provinces 1990-2000 AP decreased by 60% in some eastern provinces 1990-2000 AP decreased by 60% in some eastern provinces  Canada – US Clean Air Quality Agreement: US emissions declined by 27% between 1991-1996. US emissions declined by 27% between 1991-1996.

9. Changes in SO 2 1990-2000

10. Acid Rain in Canada THE EAST:  Canadian Shield & East Coast provinces (Ontario, Quebec, Nova Scotia, New Brunswick) are hardest hit  their water and soil systems can't neutralize the effects of the acid rain  > 150 lakes are “dead” and 48 000 are at risk of acid rain destruction  > 90% of the acid deposition in eastern Canada originates from emissions in the US Midwest

14. THE WEST  western provinces are relatively unharmed  soils are more alkaline - able to neutralize acid rain  lower levels of industrialization and natural factors such as eastwardly moving weather patterns (moves the air pollution to the east)

15. Natural Acid Precipitation (SO 2 ) Volcanic Fog “vog” (SO 2 ) Lightning (NO x ) Recap Movie Clip