UNIT # 2 Environmental Science – Matter and Energy

A ) CASE STUDY – Easter Island

Easter Island or Rapa Nui

Basic Information:

- Relatively large Island – 163.6 km2 - 64 square miles

Stillwater – 28.4 square miles

Sandyston – 43.3 SM

- Located in a subtropical region 270 S. Latitude (mild climate)

- 3600 km – 2000 miles West of Chile

- rich Volcanic soils

Inhabitation:

- 2 Estimates

- ~ 800 A.D. – radiocarbon dating / linguistic studies

- ~ 1200 A.D. – updated radiocarbon dating

- Population estimated 6000 – 20,000 – some as low as 3,000

Stillwater ~ 4300

Sandyston ~ 1900

- Polynesians

Life on the island before inhabitation:

- Pollen studies show rich subtropical forest on island for 35,00 years before

inhabitation

- Large palm in family Jubaea

- Large basswood trees

- Numerous land and pelagic birds

Frigate birds, Albatross, terns

Life during early inhabitation:

- Early fire pits showed remains of – Fish >1/4 , porpoise ~ 1/3, birds – frigate birds, albatross, boobies, terns at east 25 species

- Also showed rats (possibly imported as food) Chickens

- Around 1280 deforestation begins to occur

* Used for fuel

* Used for canoes

* Used to move famous Easter Island Statues – Moai

* possibly deforested by imported rats

- Deforestation led to some erosion

- ½ native species became extinct

- 1722 Dutch explorer Jacob Roggeveen found

* Island of grasses little to no trees

* 2-3 thousand malnourished natives

- Some evidence of cannibalism

WHAT CAN BE LEARNED?

B) Matter and the hierarchy of the Earth

Matter- anything that has volume and mass

- All life is made up of matter

- Matter must be looked at as finite

- Matter is cycled through biogeochemical cycles of the Earth

* High Quality Matter – highly concentrated (refined, pure )

- easily gathered

- easily concentrated and purified for use

- Fuel, aluminum cans, coal, salt

ALUMINUM RECYCLING

Recycling requires less than 5 percent

one can, can save enough energy to keep a 100-watt bulb burning about three and a half hours.

one-tenth the cost of the facilities to mine and refine ore

* Low quality Matter – dilute / dispersed matter

- tough to concentrate

- requires quite a bit of energy to make useful

- Bauxite ore, exhaust gas, salt solution

Atoms – Smallest unit of matter which holds the chemical properties of the atom

Biologically important – C,H,O,N,P,S, Ca, K, Na, Cl, Mg - 99%

All other 81 natural

* Isotopes – atoms with unequal # of protons to neutrons

Examples – H1 1P 0N – hydrogen

H2 1P 1N – deuterium

H3 1P 2N – tritium

Molecule- two or more atoms bonded together in a specific ratio

Organic – Molecule made up of carbon rings or chains by living things

Inorganic – all other molecules

Organelle –

Cell –

Tissue –

Organ –

Organ System –

Organism –

Populations – a group of like organisms living in a given region

Communities – all of the populations in a given area

Ecosystem – The organisms of a region as well as the abiotic environment

Biosphere – anywhere on Earth which life can be found

III. Pollution and the law of conservation of mass

·  Matter cannot be created nor destroyed

What does this mean for pollutants?

Pollutants must be dealt with. What we need to analyze.

-  Toxicity

-  Concentration of pollution

-  Persistence of pollution

How can we deal with pollution.

1-  Matter must either stay as a pollutant

2-  Be collected and recycled

3-  Be collected and interned

4-  Degrade naturally

·  Degradable

broken down through biological means

chemical means

radioactive

physical means

·  Slowly degradable (persistent pollution)

DDT

Plastics

Nuclear waste

·  Non-degradable

Elements Pb Hg As

IV. Special consideration Nuclear waste

Radioactive material – Atoms which have unstable nuclei which degrade releasing matter (alpha and beta particles) and radiant energy gamma rays.

Half life – the time required for ½ of the material to change into another isotope.

·  Steady

·  Cannot be changed

·  Often 10 half lives is thought about as bringing material to safe level

C14 - 4730 +/- 40 yr

I 131 – 8.0197 days

Pu 239 – 24110 Yrs

Danger – Radioactive materials are mutagenic carcinogenic and teratogenic

Energy and particles disrupt DNA

Where do these toxins come from?

·  Fission – The splitting of large nuclei of isotopes

-  Produces smaller elements / isotopes

-  Produces energy

-  Produces neutrons

+ Neutrons cause other fission reactions – chain reaction

+ Controlled Nuclear reactor

+ Uncontrolled nuclear bomb - atomic bombs – A bombs

August 6th 1945 – Uranium based bomb – Hiroshima

August 9th 1945 – Plutonium Based bomb – Nagasaki

100,000-200,000 deaths

·  Fusion – The building of a larger nucleus from two smaller nuclei

+ High pressures and temperatures

+ H2 – Deuterium + H3 Tritium à He4 + neutrons + energy

1P/1N + 1P/2N à 2P/2N + N

+ Hydrogen Bomb – H bomb – thermonuclear bomb

These are a thousand times more powerful than H bombs

V. Energy and the environment

Energy- The ability to do work or cause motion

2 Types

Kinetic energy – The energy of movement

- Mechanical

Wind

Water

- Heat

- Electromagnetic spectrum

Cosmic rays à radio waves

High energy Low energy

- Electrical – movement of electrons

Potential energy – Stored energy

- Stored due to position – rock, hydroelectric

- Chemical energy – stored in the bonds of molecules

- Nuclear energy – energy stored in the nucleus of atoms

Laws governing the use of energy

1st law of thermodynamics – energy cannot be created nor destroyed

Energy in = energy out

Finite energy on Earth

Energy can be transformed but not created

2nd law of thermodynamics – in any energy conversion some energy

will be “lost” as low grade energy

Energy going through transformations is degraded in process

Degradation is called Entropy

Entropy usually results in heat

Examples:

Fuel oil – oil (chemical potential energy) burned to release

heat for heating your home

Heat = low quality kinetic energy

- cannot be harnessed and reused

- escapes into atmosphere

Gasoline – High quality CPE burned

Some energy as movement of vehicle

Some as chemical potential energy (battery)

Some as light

Most as heat

Photoautotrophs – Solar energy (kinetic energy)

Converted to chemical potential energy

Some lost as heat during chemical reactions

Trophic levels – food chains

Rule of 10%

Most lost as heat – organism movement

Homeotherms

Chemical reactions

VI. What does the law of conservation of matter and the laws of

thermodynamics mean to mankind?

Focus must be on reducing matter and energy use.

5 “R’s”

* Refuse – do not purchase materials that are high pollution causers

* Replace – Find alternate sources for materials

* Reduce – Attempt to find ways to reduce initial

* Reuse – Use products for full life / find alternate uses for them

* Recycle – Reforming materials

Increase efficiencies

* Look to maximize amount of energy obtained from high quality

Energy

* Look to maximize matter resource – reduce waste

Move towards Low- throughput society

- Increase efficiencies of resource use

- Put in place matter feedback loops

- Look to reduce overall use of all products