2. Review: Conservation of Matter
• Matter cannot be created or destroyed it can only
change form
– The amount of matter in the universe is finite
(unchanging)
– Atoms (of certain elements) are recycled over and
over again.
– 92 naturally occurring elements make up nearly all matter.
– Go through innumerable chemical reactions to both form and
breakdown compounds.
– For example some of the atoms that now make up your body may
have once been part of a dinosaur, a rock, a tree, and a panda
bear at one point in their existence.
3. Review: Biogeochemical Cycle
• Bio = Biosphere (Living
Things)
• Geo = Geosphere (Rocks /
Earth)
• Chem= Chemical Factors
• Biogeochemical Cycles:
Track the repeating
movement of atoms and
energy through both the
living and nonliving parts of
the earth system.
• Biogeochemical Cycles are
the basis for nutrient
recycling and support all
life on earth!
4. Factors Affecting Cycles: Consumption
• Consumption: The rate at which a particular resource is
being used.
• Recharge Rate: The rate at which a particular resource is
replenished by the biogeochemical cycle.
• Sustainable Use: When consumption is the same, or lower,
than recharge rate. Can be maintained indefinitely.
– Renewable Resource: A resource that can be used sustainably.
Usually recharge quickly.
• Mining (Over Consumption): When the rate of
consumption for particular resource exceeds the recharge
rate. Tap into stored reserves (reservoirs) that will
eventually run out.
– Non-Renewable Resource: A resource that is not used
sustainably. Usually recharge very slowly.
5. Water Consumption
• We’ve looked in depth at
water consumption, in
short most of the world’s
water supply is not being
sustainably managed.
• This is important because
we have a very limited
supply of fresh water.
• Excessive consumption is
only half the problem
however....
6. Pollution
• The EPA defines pollution as the
“presence of a substance in the
environment that, because of its
chemical composition or
quantity, prevents the
functioning of natural processes
and produces undesirable
environmental and health
effects.”
• Pollution: The contamination of
air, water, or soil by substances
that are harmful to living
organisms and ecosystems.
• Pollutant: Any substance that
causes pollution.
7. Pollution is a Major Problem!
• Contamination further reduces the limited
amount of resources available for human use.
• Water pollution for example renders much of,
the already small amount, of the earth’s total
fresh water unsafe for human consumption.
– Water requires costly treatment and filtration
before use.
8. Types of Water Pollution
• Pollution can come from natural sources, such as
volcanic eruptions, or from human actions, such
as disposal of industrial waste.
• There are 3 main types of water pollution that
render fresh water unfit for human use:
– Inorganic Pollutants: (Ex. Heavy Metals like Lead)
• Chemical (Ex. Benzene)
• Physical (Ex. Non-Biodegradable Materials like Plastic)
– Organic Pollutants: (Ex. Fertilizer and Sewage)
– Biologic Pollutants: (Ex. Bacteria and Viruses)
• Heat and Sediment Load can also be a dangerous
pollutants for aquatic organisms.
9. Natural Sources of Pollution
• There are many naturally occurring
pollution sources.
- Sulfur springs
- Oil Seeps
- Sedimentation
- Volcanoes
• These pollution sources, however,
have been around for millions of
years.
- Ecosystems have evolved to
accommodate
them.
- Therefore, they represent less of a
threat than anthropogenic sources.
11. Point vs. Non-Point Sources of Pollutants:
• Point Sources involve the
discharge of substances from
specific areassuch as factories,
sewage systems, power plants,
underground coal mines, and oil
wells.
• Non-Point Sources are poorly
defined and scattered over broad
areas. Pollution occurs as rainfall
and snowmelt move over and
through the ground, picking up
pollutants as they go. (agriculture
runoff, storm-water drainage, and
atmospheric deposition)
12. Point Sources:
• Discharge from specific
location directly into
waterway
o Drain pipes, sewer outlets,
chemical spills.
• Can be traced back to the
source and dealt with.
– Often use aerial or satellite
imagery.
– Trace concentration levels
upstream.
• Some sources are mobile.
13. Non-Point Sources
• Runoff of pollutants
into waterway
• Farm runoff, feedlots,
golf courses, lawns
• Construction sites,
logging areas, roads,
parking lots.
• Much more difficult to
manage because they
are diffuse (spread
out).
16. What is a Physical Pollutant?
• Physical or Macroscopic
Pollution refers to
pollutants that are large
enough to be seen with
the naked eye.
– large visible items polluting
the water.
– Generally refers to human
“garbage”.
• Plastic is the most common
17. Plastic
• Man-made from petroleum,
produced through complex
(and often dangerous) chemical
processes.
• The first fully synthetic plastic,
Bakelite, was introduced by
Belgian Chemist Leo Baekeland
in the early 1900s.
• Development of Modern
Plastics
• Today plastics have
innumerable uses.
– Over 100 million tons produced
in the US per year.
18. Pros vs. Cons
• Pro:
– Easy to produce
– Cheap
– Malleable
– Waterproof and Durable
• Makes a good container
• Con:
– Not biodegradable.
– Hard to recycle.
• Costs more to recycle a plastic bag than to
make a new one.
– Production releases dangerous chemical
pollutants.
– Not very cheap when you factor in
disposal costs.
– Becomes dangerous pollutant.
19. Problems With Plastic
• The vast majority of plastics are not
biodegradable.
– They cannot be broken down by the environment.
– Stays in environment forever.
• Despite the fact that the plastic itself endures for
long periods of time most plastic products are
treated as single use disposable items.
• Less than 1% of the total plastic produced each
year is recycled.
– Americans throw away 2.5 million plastic bottles
every hour.
20.
21.
22. Once this plastic is released into
the environment it becomes a
dangerous pollutant....
