Environmental Chemistry Part Two Flashcards
What is the ozone layer?
It’s function is to shield the Earth from damaging ultraviolet radiation from the sun.
What is water quality determined by?
What it is used for:
- human drinking water
- recreation
- livestock drinking water
- irrigation
- protection of aquatic life
What are biological indicators?
Organisms that live in water and help determine it’s quality.
Types of biological indicators?
1) Microbiological- samples used to determine number and type of microscopic organism to avoid illness (ex. bacteria)
2) Aquatic- invertebrates (no backbones) indicate water quality since different types prefer different living conditions.
What are Chemical factors that indicate water quality?
1) Measuring chemicals
2) dissolved oxygen
3) phosphorus and nitrogen content
4) acidity
5) pesticides
6) Measuring toxicity
7) Heavy metals
How are chemicals measured?
concentration of chemicals is measured in ppm (parts per million) or milligrams per Liter (mg/L)
Dissolved Oxygen?
Amount of oxygen in a body of water depends upon:
- water temperature (more oxygen in cold water)
- turbulence (more oxygen in turbulent water)
-amount of phosphorus
- number of organisms living in it
Phosphorus and Nitrogen Content in water quality?
Added by sewage and fertilizer runoff. High concentration makes algae, green plants, dead matter to grow= more decomposers= less dissolved oxygen.
Acidity?
Lower the pH, the less diversity. At 4.5 most fish are gone.
Problem with Pesticides?
Some don’t degrade and have long term toxic effects. Resistance= more chemicals added to soil.
Measuring toxicity? LD50
Different chemicals affect organisms differently. LD50. LD=Lethal Does
50= 50%
LD50= amount of substance that kills 50% of test subjects.
Heavy metals?
Metals greater than 5g/cm are considered heavy. (copper, zinc)Occur naturally but not in large amounts- human activity increases amounts. (lead pipes get dissolved by acid water)
What is air made up of?
78% nitrogen
21% oxygen
less than 1% argon
0.03% other trace gases
What is air quality determined by?
1) Measuring the pollutants
2) Estimating the amount of emissions from pollution sources
What are pollutants in the air?
- Sulfur Dioxide (SO2)
- Nitrogen Oxide (NOx)
- Carbon monoxide (CO)
- Ground-level Ozone (O3)
Sulfur dioxide?
From industrial processes (oil&gas industry) contributes to smog, affects the respiratory system, scrubbers use limestone to convert it into something useful (gypsum)
Nitrogen Oxide?
Formed from fossil fuel emissions, combustion at generating plants, industrial processes, brown gas and gives smog its color. Affects respiratory system, eyes.
Carbon Monoxide?
Silent killer. Colorless odorless causes headache, sleepiness, brain damage, death) made by burning fossil fuels or when anything with carbon is burned (forest fires). Catalytic converters use platinum and palladium to remove pollutants from vehicle exhaust.
Ground Level Ozone?
Formed by reactions between oxygen, nitrogen, volatile organic chemicals (VOC- solvents and gasoline). Affects respiratory system of people with asthma, lung disease, cold. Affects crops. Causes materials to deteriorate (plastic).
