1. Environmental Chemistry

2. Air (Atmosphere) ** Water (Hydrosphere)
The Environment
Air (Atmosphere) ** Water (Hydrosphere)
Land (Lithosphere)

3. Parts of the Atmosphere
Troposphere:
From earth’s surface to 15 km
The air we breathe
Stratosphere
15 – 50 km
Ozone layer

4. Parts of the Atmosphere
Troposphere:
From earth’s surface to 15 km
The air we breathe
Stratosphere
15 – 50 km
Ozone layer

5. Composition of the Troposphere
Contains 75% of all gases
Mostly N2 and O2
Also dust, ice, salt, liquid water

6. Composition of the Stratosphere
Lighter gases (H2, He)
Ozone Layer – high concentration of ozone (O3)

7. Earth’s Water - Hydrosphere
Surface water: oceans, streams, rivers
Groundwater: beneath the surface

8. Earth’s Water - Hydrosphere
Most of the water on earth is undrinkable (salt water)

9. Water Cycle 3 3 2 5 6

10. Earth’s Crust - Lithosphere
Oxygen is most abundant element

11. Earth’s Crust - Lithosphere
Resources: - Minerals (gold, silver, diamonds)
- Fuels (crude oil, natural gas, coal)
- Groundwater

12. Earth’s Crust - Lithosphere
Groundwater: water located beneath the earth’s surface in the spaces between soil particles.

13. Pollution
Introduction of contaminants (chemicals) into the natural environment.
Types of pollution:
Air pollution
Water pollution
Soil contamination
Groundwater contamination

14. Pollution
Air Pollution Sources

15. Pollution
Water Pollution Sources

16. Pollution
In Southern California, all storm water drains to the ocean.

17. Pollution
Soil and Groundwater Pollution Sources

18. Pollution

19. Where does it go? Spill 20 gallons of gasoline on the dirt
Burning coal in a power plant
Burying hazardous chemicals in a landfill
Dumping toxic chemical in the gutter on your street
5. Spraying pesticides on crops

20. Where does it go? Driving your car
Dumping mercury down the drain in the chemistry lab sink
A leaking diesel tank on a boat in a lake
Using nail polish remover (acetone)
10. Waste discharge from a factory into a river

21. Making Air Pollution in a Cup
Nitrogen oxides (NO and NO2) – Cocoa
Hydrocarbons – Blue food coloring
Carbon monoxide (CO) – Red Food Coloring
Sulfur dioxide (SO2) – Drink mix
Dust – Charcoal
Ozone – Yellow color

22. Making Air Pollution in a Cup
If the air pollution around you were this apparent, would you want to breathe the air?
What other sources of air pollution, beyond those mentioned in this demonstration, could you think of as being produced in a single day?
What could you do to reduce the number of pollutants released each day?

23. Chemistry in the Troposphere
SMOG: Smoke + fog
- In London, known for centuries.
- In 1879 – 4 continuous months of smog
- In December 1952, smog killed 12,000 people in London.
- This led to the beginning of our Air Laws in the U.S.

24. Chemistry in the Troposphere
PHOTOCHEMICAL SMOG
- In Los Angeles (and Denver, Mexico City), smog is created when sunlight reacts with air pollutants.
Most pollutants are from vehicles:
Nitrogen oxides (NO and NO2)
Hydrocarbons
Carbon monoxide (CO)
Sulfur dioxide (SO2)
Dust particles

25. Chemistry in the Troposphere
PHOTOCHEMICAL SMOG (Ozone)
In the troposphere, ozone is produced in the atmosphere.
It irritates eyes & lungs and causes asthma and pneumonia
NO2 + UV light  NO + O
O + O2  O3

26. Pollution

27. Acid Rain
Acidic particles are produced when pollutants SO2 and NO2 mix with water vapor in the atmosphere.

28. Acid Rain SO2 forms sulfuric acid (H2SO4).
NO2 forms nitric acid (HNO3).

29. Acid Rain
Acidic particles fall to Earth in two different ways: wet deposition and dry deposition.

30. Acid Rain
Wet Deposition: Rain is naturally acidic because of dissolved CO2, but acid rain has a pH of less than 5.6. Can also be acidic hail, snow or fog.

31. Acid Rain
Dry deposition takes place when acidic particles attach to dust particles in the atmosphere and fall to the ground.
These particles stick to cars, buildings, and trees. The acidic particles make any rain water run off or wash water acidic.

32. Effects of Acid Rain

33. Effects of Acid Rain Lowers the pH of lakes and streams.
Most fish cannot survive if pH is less than 5

34. Effects of Acid Rain Harms trees and forests
Damages tree leaves and changes the chemistry of forest soil

35. Effects of Acid Rain
Damages buildings and statues, especially those containing calcium carbonate (limestone & marble).
1908
1968

36. Effects of Acid Rain
Damages metal structures (the copper Statue of Liberty) and automotive paint.

37. REVIEW What two ways do acidic particles fall to Earth?
- Wet deposition (rain) and dry deposition
2. What two pollutants cause acid rain?
- SO2 forms sulfuric acid (H2SO4) and NO2 forms nitric acid (HNO3).
3. Why is acid rain harmful to fish?
- Most fish cannot survive if the pH < 5
What else does acid rain damage?
- trees & forests, buildings & statues, automotive paint