Environmental Chemistry

1. Environmental Chemistry

2. Environmental Chemistry…in Hollywood… • http://www.youtube.com/watch?v=PvpzcapmTUI • http://www.youtube.com/watch?v=5Jdk3riKKwo • What does this have to do with me??? • Hmmmm….

3. Big Ideas for Unit C • Investigate the role of beneficial and harmful substances in the environment. • Identify processes of measuring the quantity of substances in the environment. • Identify processes for monitoring air and water quality. • Analyze the distribution of of potentially harmful substances within an environment.

4. GO C1 Investigate and describe, in general terms, the role of different substances in the environment in supporting or harming humans and other living things. http://www.chem4kids.com/files/art/etcetera_envirochem1_240.jpg 1.1 Chemicals in the Environment

5. Guided Question How do harmful substances enter and interfere with an ecosystem through the water, carbon, and nitrogen cycles?

6. Environmental Cycles • Essential nutrients are naturally recycled in our environment. • The Earth runs into pollution problems when harmful substances interfere with these cycles or enter an ecosystem through these cycles.

7. Water cycle http://pmm.nasa.gov/education/sites/default/files/article_images/Water-Cycle-Art2A.png http://www.youtube.com/watch?v=oaDkph9yQBs

8. The Carbon Cycle http://www.ucar.edu/learn/images/carboncy.gif http://www.youtube.com/watch?v=mldBE9Ee3zY

9. Nitrogen Cycle http://www.youtube.com/watch?v=tSzLQojOItg

10. Most organisms are unable to use nitrogen (N2) unless it is joined to other elements. • Nitrogen-Fixation is the process of changing free nitrogen so that the atoms can combine with other elements to form compounds that organisms can use (NH3) • Nitrogen-fixing bacteria found in the plant nodes or nodules of legumes such as peas, beans, clover and alfalfa, convert nitrogen from the air into nitrates. • Lightning, too, converts nitrogen gas into nitrates.

11. Human Activities Agricultural activities • A fertilizer is a substance that enriches the soil so that plants will grow better. • Fertilizers contain three elements: nitrogen, phosphorous, and potassium. • Too much fertilizer can damage organisms (burn) in the soil and even damage crops. If too much fertilizer gets into ponds, streams, etc. it can damage ecosystems.

12. Healthy coral Dead Coral – Fertilizers??

13. The three numbers indicate the percentage of each element contained in the fertilizer • In this fertilizer there would be 16% Nitrogen, 0 % Phosphorus and 8% Potassium

14. Pesticides are chemicals used to kill or control pests. A pest is an organism that harms people, crops, or structures. Some pesticides are non-selective – they kill both pest and non-pest species. Some pests become resistant to pesticides so new and stronger pesticides must be developed.

15. Pesticides • Pesticides are grouped according to the pest that they control or kill. • Herbicides kill or control weeds • Insecticides kill or control insects • Fungicides kill fungi

16. DDT DDT was a popular insecticide for mosquitoes until it was found to weaken the shells of bird’s eggs, causing rapid decline of bird populations

17. Solid wastes • Solid waste includes the solid garbage that is collected form households, industrial plants, commercial buildings, institutions etc. • The safest way to dispose of solid waste is to reuse or recycle it • Waste that can’t be reused or recycled is placed in landfill sites • Sanitary landfills use plastic liners and compacted clay to prevent water from moving through the solid waste and bringing chemicals into the soil and ground water

19. Wastewater • The major pollutants affect the water by depleting valuable oxygen in the water and at the same time adding poisons to the water. • When oxygen is present, bacteria will decompose raw sewage. However, where there is an overload of sewage, so much oxygen is used up that fish and other aquatic life will die.

21. Waste H2O containing dissolved and undissolved materials is called sewage and must be treated. • In cities sewage moves to a sewage treatment plant or a septic tank in rural areas • During heavy rainstorms, overflow wastewater is sometimes carried directly to a body of water without treatment by storm sewers.

22. Sewage Septic tank Bacteria break down organic materials Sewage treatment plant Treats waste form homes, businesses etc After treatment effluent is released

23. The treatment process involves three stages: • Physical: much of the larger material is filtered out by screens. • Biological: organic sewage material is decomposed by the action of bacteria. • Chemical: chemicals are added to remove inorganic phosphates and nitrates.

24. Fuel combustion Fossil fuels are non-renewable resources and are formed from dead plants and animals. When fossil fuels are burned, they produce CO2 and water vapour. Combustion of fuels Hydrocarbon + oxygen carbon dioxide + water + ENERGY (Any fuel) **Could be methane, propane, gasoline - doesn’t matter

25. Industrial Processes • Natural gas is processed to separate its components for different uses. • When hydrogen sulfide is found in natural gas it is referred to as sour gas. • H2S(g) must be removed because it is poisonous. This results in sweet gas. • With removal of H2S(g) , SO2 and S are released and need to be monitored.