Transcript Handing in Homework

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Topics, Concepts, Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
According to
•Waterborne diseases are
WHO (World
common in India.
Health
Diarrhea kills 500,000
Organization), 1
Indian children each year.
billion people do
Very few of India’s cities
not have safe
have sewer systems & most
drinking water:
of those systems are not
treated.
•More than 67% of
Africa’s population lacks
sanitary disposal of
sewage.
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Topics, Concepts, Review
Questions
Information, Vocabulary, Main Points: YOUR NOTES
Typhoid A disease caused by the
fever- bacteria, Salmonella typhi,
transmitted in water
contaminated with human
waste.
Cholera- A disease caused by the
bacteria, Vibrio cholerae,
found in water
contaminated by human
waste.
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Topics, Concepts, Review
Questions
Information, Vocabulary, Main Points: YOUR NOTES
Cholera
outbreaks
have
occurred
here:
•People who traveled to parts
of Latin America, Asia, or
Africa brought it back.
U.S. Safe
Drinking
Water Act
(SDWA):
•Passed in 1974.
•Travelers bringing food back
have caused foodborne
outbreaks.
•Requires EPA to regulate
substances in the water supply
that may threaten health.
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Topics, Concepts, Review
Questions
Coliform
bacteria:
Information, Vocabulary, Main Points: YOUR NOTES
Are indicator organisms
because their presence indicates
poor water quality.
Are normally found in the
intestines of humans & other
animals.
If present in the water......may
be contaminated with human or
animal waste along w/other
harmful organisms.
Water is only fit to drink if
tests confirm zero coliform!
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Topics, Concepts, Review
Questions
Information, Vocabulary, Main Points: YOUR NOTES
Parasitic Unfiltered water may contain
protozoa: these tiny microbes.
Once inside the human intestine,
Cryptosporidium parvum causes
cryptosporidiosis, a flu-like illness
accompanied by diarrhea.
400,000 people became ill w/this
protozoan & 50 died when the
filtration process at Milwaukee
water treatment plant became
ineffective due to a period of heavy
rainfall & runoff in 1993.
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Topics, Concepts,
Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Most common water-related disease
in U.S. today is from a one-celled
Giardia lamblia.
They live in protective capsules (cysts) &
can survive for over two months in water,
especially cold mountain streams.
The parasite lives in the intestines of
humans & other mammals (beavers, deer,
dogs, etc.).
It causes giardiasis (beaver fever) –
abdominal cramping, nausea, gas, diarrhea.
Cysts have been found in surface water in
all regions of U.S.
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Topics, Concepts, Review
Questions
EPA
(Environmental
Protection
Agency):
Information, Vocabulary, Main Points: YOUR NOTES
Sets legal limits for
substances found in public
water supplies.
Determines water testing
schedules.
Prescribes treatment
methods.
Has set health goals for
more than 80 inorganic &
organic chemicals.
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Topics, Concepts, Review
Questions
Information, Vocabulary, Main Points: YOUR NOTES
What is Refers to safe drinking water.
potable
All surface water should be
water?
treated 1st before drinking.
Well or spring water may be safe
to drink without treatment—it
depends upon the soil type, depth
& distance from any pollution
source.
If well water contains high levels of
nitrates, it should be tested for
pesticides.
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Topics, Concepts, Review
Questions
Information, Vocabulary, Main Points: YOUR NOTES
Physical & Chlorination
chemical
Most common method, but it
water
changes the taste of water.
treatment Ultraviolet light
processes:
Water passes through a chamber
with UV lights that kills bacteria.
Must be filtered 1st so bacteria
cannot be hidden from light.
More expensive than
chlorination.
Heat
Water is heated to a rolling boil
for at least 1 minute.
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Topics, Concepts,
Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Filtration
Activated carbon filters remove
organic chemicals that cause color,
taste, or odor; the organic chemicals
stick to the surface of the carbon
particles a called absorption.
Sediment filters work like a
coffee filter or tea bag; they allow
the water to pass through & hold
back the particles; they do not
remove chemicals dissolved in the
water.
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Filtration Methods:
Particles may be physically removed
by installing cartridge-type sediment
filters in the water line. These
filters work in the same way as a
coffee filter or tea bag. They allow
the water to pass through and hold
back the particles. They do not
remove chemicals dissolved in the
water. Large water treatment
systems use graded sand filters to
remove particles.
Activated carbon filters are designed to
remove organic chemicals that cause color,
taste, or odor. The organic chemicals stick
or adhere to the surface of the carbon
particles. The process is called adsorption.
The EPA requires all water supply systems
serving populations over 10,000 people to
install carbon filtration systems if their
water supplies are contaminated with
organic chemicals.
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Water Treatment Processes at the Waterworks
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Is Bottled Water the Answer?
 Some bottled water is not as pure as tap
water and costs much more.
 1/4th of it is ordinary tap water.
 Bacteria & fungi contaminate 40% of it.
 1.4 million metric tons of plastic bottles are
thrown away.
 Fossil fuels are used to make plastic
bottles.

The oil used to produce plastic bottles in the
U.S. each year would fuel 100,000 cars for a
year!!!
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Topics, Concepts, Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Some cities with older water
systems do not have meters, &
residents pay a flat rate
regardless of the amount used.
Studies show the use of water
declines as water rates increase.
Water use dropped 36% after
Boulder, CO installed water
meters.
Making people pay more for the
water they use encourages them to
use water more efficiently.
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Topics, Concepts, Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Leaky
Much water is wasted
water
through leaky pipes &
systems: fixtures.
Leaky faucets & toilets misuse
water.
A faucet w/a slow leak can
waste 5 gallons/day, while a
leaking toilet can waste 22
gallons.
Distribution systems in
many big cities are old &
need replacement.
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Topics, Concepts, Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Water- By installing these, a typical
saving
family of 4 can reduce their
fixtures: water usage by 90-140
gallons/day.
Depending on the area’s
water rate, these fixtures can
save $100-$300 per year.
Low-flow shower heads can
also decrease electric bill
because you’ll use less hot
water.
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Topics, Concepts, Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Flow control aerators on
kitchen & bathroom faucets
reduce water flow rate by 60%.
New manufactured toilets
limit flow to 1.6 gallons per
flush instead of the old 5
gallons/flush.
Xeriscape
Uses native, drought-tolerant
landscaping: plants; uses 30-80% less water
than conventional lawns.
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Topics, Concepts, Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Irrigation By improving this, farmers
efficiency: can reduce erosion, prevent
loss of fertilizer, & save
their cost of energy to
pump the excess water.
Gravity-flow systems
reduces water needs by 30%
by capturing water that
normally runs off the crop’s
field.
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Topics, Concepts,
Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Computerized irrigation systems
detect leaks, adjust water flow for
wind speed & soil moisture.
Most efficient method of irrigation
= subsurface drip irrigation system
which has buried perforated plastic
pipes that feed water directly to the
plant roots.
TX farmers have cut evaporation
losses by using low-energy precision
application (LEPA) = a new centerpivot irrigation system that delivers
water closer to the ground.
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Center pivot with drip sprinklers
(LEPA)
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Topics, Concepts, Review Questions
The sea is
a very
large
reservoir,
but it is
not fit to
drink.
Information, Vocabulary, Main Points: YOUR NOTES
90% of the dissolved salts
are sodium (Na) and chlorine
(Cl) ions; the other 10%
include calcium (Ca),
magnesium (Mg), potassium
(K), phosphate, & nitrate ions
that come from the
weathering of rocks & erosion
of the soil.
When water evaporates, the
ions are left behind making
seawater highly saline (salty).
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Topics, Concepts, Review Questions
Desalting
the sea:
(removing
dissolved ions
from saline
water)
Information, Vocabulary, Main Points: YOUR NOTES
Reverse osmosis – water is
forced through a membrane
with openings large enough
to allow water molecules to
pass through , but too small
to allow the ions to pass
through.
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Topics, Concepts, Review Questions
Desalting
the sea:
(removing
dissolved ions
from saline
water)
Information, Vocabulary, Main Points: YOUR NOTES
Electrodialysis – water
flows through a chamber
that contains electrodes
w/positive & negative
charges.
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Topics, Concepts, Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Flash distillation – water is
superheated in chambers
where reduced pressure
causes it to change into steam
which condenses on coils of
pipe cooled by seawater.
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Topics, Concepts, Review Questions
Information, Vocabulary, Main Points: YOUR NOTES
Solar distillation – uses the
sun’s energy for evaporation
and a dome-shaped surface
for condensation of the water
vapor.
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Topics, Concepts, Review Questions
The
downside
to
desalting
factories:
Information, Vocabulary, Main Points: YOUR NOTES
All processes except for
solar distillation require huge
inputs of energy.
Cost of energy makes
desalted water very
expensive.
Solar is less expensive, but it
requires large amounts of
space.
Brine (salt wastewater)
disposal—where to put it, what
to do w/it?
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Topics, Concepts, Review Questions
Removing
salts from
saline
water
makes it
taste flat.
Information, Vocabulary, Main Points: YOUR NOTES
To improve the flavor, it
is mixed with water from
local wells before being
piped to consumers.
It can also flow over
broken coral pieces to
replace some minerals &
give it a more pleasant
taste.
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