Organic chem

  • Study of carbon containing compounds

    • Often containing hydrogen and oxygen

      • Hydrocarbons = hydrogen and oxygen

      • Hydrocarbon derivatives = hydrogen, carbon, and other atoms

    • Carbon is unique because it forms 4 bonds with other elements

Benzene rings

  • Ex) Gasoline, plastic, rubber cement, bug repellant, fungicides

    • Why are these compounds dangerous?

      • Stable

      • Can leach into drinker water and is carcinogenic(cancer causing)

      • Found in the incomplete combustion fuels and gasoline

    • Benzene is classified as a persistent organic pollutants(POP) because it is stable and not easily broken down by chemical or biological means

Halogenated hydrocarbons

  • Ex) CFC(chlorofluorocarbons)

    • Used as refrigerants in refrigerators, air conditioners, and aerosol cans

    • Linked to stratospheric ozone depletion


    • PVC(polyvinyl chloride)

    • Carbon tetrachloride used as cleaning solvents, now known to be carcinogenic

Other substance that contain harmful halogenated hydrocarbons

Halogenated compound

Incineration(burning garbage)



PCB’s(polychlorinated biphenyl)



Dioxins and furans


DDT

What is it used for?

Burning garbage can release chlorine into the air


Manufacturing plastics and old electrical transformers


Pulp and paper bleaching


Pesticides for insects

  • All of these can bioaccumulate in the food chain

What are some effects of insecticides?

  • Many pesticides get rid of insects by affecting their nervous system

  • Overuse can lead to pesticide resistant organisms

  • Spray pesticides can be carried by wind or water currents to other areas and affect other components of the ecosystem

Biomagnification

  • Biomagnification is the increase of concentration of pesticides, dioxins, furans, and heavy metals as we move up the food chain

  • Toxins accumulate in fatty tissue and are not released in wastes

  • The animal at the top of the food chain has the highest concentration of accumulated toxins

Ozone and concerns regarding CFC’s

  • We have 2 types of ozone that exist in our atmosphere

  1. Tropospheric(low level) ozone - Bad, helps trap greenhouse gasses and contributes to smog

  2. Stratospheric(high level) ozone - good

  • UV radiation helps to form stratospheric ozone layer

  • By absorbing excess UV radiation, the upper ozone, O3 protects us from excess levels of UV radiation

  • Chlorofluorocarbons(CFC) in the upper atmosphere can lose a Cl atoms which can breakdown the ozone

Esters

  • Commonly founds in fats, polyester, plastic, soap, and used as flavor and aroma


Fertilizers and organic matter/wastes

  • Water quality can be negatively affected by acid deposition, leaching of metal ions, and pesticides

  • Contaminating water with fertilizers or organic matter can also negatively impact aquatic ecosystems

  • Excess use of fertilizers rich in nitrates and phosphates can leach from fields into our water systems

    • This results in what is known as an algal bloom(increase in algae)

    • This is negative as it uses up all the oxygen available in water

What is biological oxygen demand(BOD) “Bacteria”

  • BOD is the measure of the amount of oxygen used by microorganisms as they decompose waste

  • High BOD indicates that there is high amount of organic matter or sewage in our water systems

  • 3 things that increase BOD

  1. Large amounts of organic waste

  2. Nitrates and phosphates from run off and fertilizers(=high algae growth)

  3. Warm temperatures

  • High BOD = dirty, high organic water and high bacteria