1. Environmental Chemistry
Unit C
Environmental Chemistry

2. Chemicals in the Environment
1.1
Chemicals in the Environment

3. A. The Environment
everything in our environment is made up of chemicals
many chemicals in the environment support life
eg) CO2, H2O, O2, glucose etc.
there are also many chemicals that do not support living things
eg) CO2, sulphur dioxide, ash
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4. these chemicals can come from natural sources
eg) volcanoes, forest fires
can also come from human activity
eg) burning fossil fuels
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5. B. The Nitrogen Cycle
plants need nitrogen for growth & reproduction, but they can’t use “free nitrogen” (N2 gas) from the atmosphere
during nitrogen fixation, bacteria combine free nitrogen with other elements such as oxygen
plants then consume the fixed nitrogen through the water they take in
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6. animals eat plants, and make complex nitrogen compounds like proteins
microorganisms then break nitrogen compounds back down into free nitrogen, beginning the cycle again
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7. C. Human Activities
human activities can also change substances in the environment
pollution is any change in an environment, to produce conditions harmful to living things
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8. a fertilizer is a substance that enriches the soil so plants will grow
Fertilizers
a fertilizer is a substance that enriches the soil so plants will grow
too much fertilizer can harm a plant, or leach into water systems and harm other organisms
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9. pests are organisms that can harm humans, plants or structures
Pesticides
pests are organisms that can harm humans, plants or structures
pesticides are chemicals designed to kill pests: herbicides, insecticides or fungicides
pesticides that are incorrectly applied can cause damage to the environment
eg) DDT kills mosquitoes but takes 2-15 years to break down
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10. other waste is reused or recycled
Solid Waste
when we get rid of garbage, we can introduce chemicals into the environment
some waste is incinerated at high temperatures, which can cause pollution
other waste is reused or recycled
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11. remaining waste is put into landfill sites, and buried to biodegrade (which can be slow!!)
sanitary landfills use compacted clay and plastic liners to isolate hazardous chemicals
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12. sewage treatment plants remove harmful substances from wastewater
sewage is wastewater which contains dissolved and undissolved substances
septic tanks use bacteria to break down organic molecules in wastewater
sewage treatment plants remove harmful substances from wastewater
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13. effluent is treated wastewater that is released into streams and lakes
storm sewers are large pipes that take rainwater directly to rivers and lakes
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14. many industrial processes, especially in Alberta, use fossil fuels
eg) natural gas processing, electrical power generation
fossil fuels are combustible substances made from dead plants and animals
eg) coal, natural gas, oil
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15. fossil fuels need oxygen to combust
products are always carbon dioxide and water, which are both greenhouse gases
natural gas is composed of fossil fuel gases
when it contains deadly hydrogen sulphide, it is called “sour” gas
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