Transcript Water-soluble Inorganic Chemicals – acids

WATER POLLUTION
Contaminant vs. Pollutant
• Contaminant- any constituent in the water that is
harmful to its end use. (radon, coliform bacteria
from animals, arsenic & other metals naturally in
rock/soil)
• Pollutant- any constituent in the water that is
harmful to its end use and is anthropogenic in
origin. (septic waste, gasoline, oil, industrial
waste, herbicide/pesticides)
Water Pollution
Any chemical, biological and physical
change in water quality that has a
harmful effect on living organisms or
makes it unusable for agriculture
Point vs. Non-Point
Pollution
• Point
– Discharged from a specific
location
– Usually from a pipe directly
into water
– Sources identifiable which
makes it easier to monitor
& regulate
– EX: factories, sewage
treatment plants, coal
mines, oil wells
• Non-Point
– Discharged from scattered
or diffuse locations
– No specific location where
the discharge came from
– Harder to monitor &
regulate; may be episodic
• 1st heavy rainfall washes
lots of gas, oil, trash into
river
– EX: runoff from feedlots,
farm fields, golf courses,
lawns, construction sites,
logging areas, streets,
parking lots, atmospheric
deposition (grasshopper
effect)
Types of Pollution
• Disease-causing Agents – pathogens
• Oxygen Demanding Agents – organic waste: manure
• Water-soluble Inorganic Chemicals – acids, toxic
metals
• Inorganic Plant Nutrients – nitrogen and phosphorus
• Organic Chemicals – oil, pesticides, detergents
• Sediment or Suspended Material – erosion, soil
• Water-soluble Radioactive Isotopes – radon uranium
• Thermal– electric and nuclear power plants
• Genetic Pollution
Disease-Causing Pathogens
• Most serious water pollutant
• Types: typhoid, cholera, dysentery, enteritis, polio, hepatitis,
schistosomiasis, filariasis, yellow fever, and esp. malaria.
• Sources: untreated or improperly treated human waste; animal
waste from feedlots, fields near waterways
• MDC- not as common due to WWTP
• LDC- WWTP non-existent or primitive; 80% of illness
contributed to waterborne pathogens and inadequate sanitation
• Test for coliform bacteria (live in colon or intestine of humans or
other warm-blooded animals); if coliform bacteria present,
assume that infectious pathogens also present
Waterborne Pathogens
• Disease symptoms usually are explosive
emissions from either end of the
digestive tract
Escherichia coli
Giardia
Hepatitis A
Norwalk Virus
Types of Pollution
• Disease-causing Agents – pathogens
• Oxygen Demanding Agents – organic
waste: manure
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Water-soluble Inorganic Chemicals – acids, toxic metals
Inorganic Plant Nutrients – nitrogen and phosphorus
Organic Chemicals – oil, pesticides, detergents
Sediment or Suspended Material – erosion, soil
Water-soluble Radioactive Isotopes – radon uranium
Thermal– electric and nuclear power plants
Genetic Pollution
Oxygen in Water
• Amt of O2 in water good indicator of water quality
• 6ppm supports game fish & other aquatic life.
• 2ppm or less supports worms, bacteria, fungi,
decomposers.
• How does O2 get into water?
– Dissolves from air
– Turbulence over rocks traps air in bubbles
– Photosynthesis from algae & plants
• How is O2 removed from water?
– Respiration by plants & animals
– Chemical processes
– A lot by bacteria & other decomposers
Measuring Oxygen in Water
• Biological Oxygen Demand (BOD)Standard test of the amt of DO
consumed by aquatic
microorganisms over a 5-day
period.
– If BOD levels are high, DO levels
are low because there are too
many bacteria using O2 in water
• Called Oxygen sag
– Pristine waters register 1 mg/l or
less BOD
– Sewage water has 20 mg/l or
more.
• Dissolved Oxygen Content (DO)directly measures O2 content in
water with chemicals or electrodes.
• Fast moving waters are more likely
to recover from oxygen depleting
event because they are able to
easily replenish O2 with bubbles.
BOD Effects on Water Quality
Oxygen
sag
All streams have some capability to degrade organic waste.
Problems occur when stream is overloaded with biochemical
oxygen-demanding waste.
Sources of Organic Matter Pollution
that lowers DO levels
• Natural inputs-- bogs, swamps, leaf fall,
and vegetation aligning waterways.
• Human inputs-- pulp and paper mills,
meat-packing plants, food processing
industries, and sewage treatment plants.
• Nonpoint inputs-- runoff from urban
areas, fertilizer from farms, manure from
feedlots.
Inorganic Plant Nutrients
• Eutrophication: occurs
naturally over 100’s1,000’s years
• Cultural Eutrophicationcaused by human
pollution; occurs over
decades
• Sources of cultural
eutrophication:
– Increased nitrate or
phosphates from
sewage, manure, or
fertilizer
– Higher temperatures
– Increased sunlight
Steps of Cultural Eutrophication
• Nitrogen & phosphorous from fertilizer, manure, sewage
enter ecosystem
• Algae bloom- grow excessively
• Cover top of water & keep sun out
• Algae outcompete each other
• Algae die & water plants die b/c get no sunlight
• Decomposers use up O2 in water when decomposing
their bodies
• Lake becomes hypoxic and fish & other organisms die.
• Clear lakes with low biological productivity are called
oligotrophic.
• As organisms die and siltation occurs from erosion, lake
fills in & becomes forest
Cultural Eutrophication & Oceans
• Can occur near shore or
in bays or estuaries
• “Dead zones” are
common
– Largest in Gulf of Mexico
near Mississippi River
(about 7,000mi2- size of
New Jersey)
– Watershed of Mississippi
allows lots of fertilizer into
river which dumps into
Gulf.
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Cultural Eutrophication & Oceans
• Red Tide- caused by
dinoflagellates that release
toxin; shellfish poisonous
• Pfiesteria piscicida
– Piscicida means “fish killer”
– Most notably found in 1980’s &
90’s off coast of North Carolina
& Maryland
– Type of algae that produces
toxins when fish enter bloom.
Toxins paralyze fish so they
can’t escape & produce skin
lesions that cause secondary
infections leading to death.
– Humans: blurred vision,
burning muscles, difficulty
breathing, memory loss, major
organ damage- just breathing it
in is dangerous
Types of Pollution
• Disease-causing Agents – pathogens
• Oxygen Demanding Agents – organic waste: manure
or sewage
• Inorganic Plant Nutrients – nitrogen and phosphorus
• Water-soluble Inorganic Chemicals –
acids, toxic metals
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Organic Chemicals – oil, pesticides, detergents
Sediment or Suspended Material – erosion, soil
Water-soluble Radioactive Isotopes – radon uranium
Thermal– electric and nuclear power plants
Genetic Pollution
Inorganic Pollutants
metals, salts, acids
• Metals– Mercury, lead, cadmium, nickel
– Persistent; bioaccumulate
– Minamata disease- mercury poisoning
– South America- use mercury to mine
for gold, mercury now contaminating
Amazon river
– Tin was used as antifouling agent on
boat hulls but now banned due to
negative health effects.
– Cadmium poisoning in Japan from
mining & smelting waste-water
discharge
– Lead pipes, solder, can cause lead
poisoning. Acidic water can leach
lead out of pipes.
– Mine drainage & leaching of mining
waste
Inorganic Pollutants
metals, salts, acids
• Salt
– Arsenic
• Found naturally in some
bedrock (Bengal, India) as
insoluble salts
• When they are exposed to air
they become soluble & cause
problems: inflamed eyes,
gastrointestinal problems,
scaly skin, skin tumors,
anemia, death
– NaCl
• Sources: deicing roads,
aquifers used for irrigation
• As aquifer becomes depleted,
salt concentrates. When
pumped up for irrigation,
water evaporates, leaving salt
behind making soil unsuitable
for crops.
Inorganic Pollutants
metals, salts, acids
• Sources: metal
smelting, coal mining,
power plants,
petroleum distillation
• Acid leaches out
aluminum from soil &
rocks harming aquatic
life or soil
• See notes on acid
rain & acid mine
drainage
Types of Pollution
• Disease-causing Agents – pathogens
• Oxygen Demanding Agents – organic waste: manure or
sewage
• Inorganic Plant Nutrients – nitrogen and phosphorus
• Water-soluble Inorganic Chemicals – acids, toxic metals
• Organic Chemicals – oil, pesticides,
detergents
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Sediment or Suspended Material – erosion, soil
Water-soluble Radioactive Isotopes – radon uranium
Thermal– electric and nuclear power plants
Genetic Pollution
Organic Chemicals
• Sources: pesticides
(atrazine, DDT, dioxins),
plastics, pharmaceuticals,
oils
• Problems: birth defects,
genetic disorders, cancer
• Resistant to degradation;
bioaccumulate
• Come from: improper
disposal of industrial &
household waste, runoff
from pesticides from
farms, golf courses, etc.
Sediments
• Erosion from
– Poor farming & grazing techniques
– Urbanization- excessive construction
– Deforestation
• Problems caused for people:
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Fills in lakes, reservoirs
Obstructs shipping channels
Clogs hydroelectric turbines
Purification of drinking water more expensive
Aesthetic degradation
• Problems caused for ecosystems:
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Blocks sunlight; makes water turbid (cloudy)
No photosynthesis- plants die
Less oxygen in water, fish die
Covers gravel which is place some fish & insects
lay eggs
• Can be good
– Sediment creates fertile flood plain
– Replenishes islands in bays & estuaries
Radioactive Isotopes
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Uranium- from mine tailings into
surface water
Plutonium Case Study- Savannah
River Site
– 1950’s plutonium reactors built
along river in S.C. Plutonium
used for H-bombs
– William Lawless was put in charge
of radioactive waste disposal even
though he had no prior experience
– He was told to dump high-level
water waste in unlined canals and
to bury high level solid waste in
cardboard boxes. Radioactive
waste leached into groundwater
supply
– When he questioned this he was
told to keep quiet.
– He went public, was fired, and the
plutonium reactors have since
been shut down.
– Many people affected by rare
cancers associated with radiation
poisoning
Thermal pollution
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Sources:
– Mostly from power plants
(especially nuclear)
• Withdraw water, cools systems,
discharge hot water if they don’t
have cooling towers. Sometimes
cooling towers fail & release
thermal plumes.
– Removal of vegetation over river
for construction
• Now required to keep riparian
zone on either side of river
– Concrete/parking lots heat up
during day, afternoon rains wash
hot water into river
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Effects:
– Many fish species sensitive to one
degree change in temp. die
– High temps decrease DO levels in
water causing fish suffocation
Thermal Pollution
This 1988 thermal image of the Hudson River
highlights temperature changes caused by discharge
of 2.5 billion gallons of water each day from the
Indian Point power plant. The plant sits in the upper
right of the photo — hot water in the discharge canal
is visible in yellow and red, spreading and cooling
across the entire width of the river. Two additional
outflows from the Lovett coal-fired power plant are
also clearly visible against the natural temperature of
the water, in green and blue.
OCEAN POLLUTION
Ocean Pollution
• Coastal areas most impacted –
especially wetlands and
estuaries, coral reefs, and
mangrove swamps
– Heavily used, little circulation
• About 35% of U.S. municipal
sewage discharged virtually
untreated in ocean waters
• Dumping of industrial waste
directly into ocean off U.S.
coasts stopped, but many
countries still dump large
quantities of toxic substances
• Ocean is the ultimate
repository of waste
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Main Types of Ocean
Pollution
Petroleum (oil)
Sewage sludge
DDT and PCBs
Mercury
Point source: obvious origin- usually pipe
(municipal sewage outfall pipe, oil tanker spills,
offshore oil well blowouts)
• Non-point-source pollution: ill-defined or diffused
sources, runoff (harbors and marinas, powerboat
pollution, invasive species, agriculture, forestry,
urban runoff, ocean debris, air pollution, noise
pollution, dredging
Ocean Pollution: Petroleum
• Oil spills can
be caused
by:
– Tanker
accidents
– Intentional
dumping
– Drilling/
pumping
operations
bss.sfsu.edu/ehines/geog600/
Freshwater%20and%20ocean%20Pollution.ppt
Effects of Oil Spills
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Volatile Organics Compounds
immediately kill many of the
aquatic organisms (especially
plankton and larvae) and
contaminate fish
Floating oil coats birds and
ocean mammal; destroys natural
insulation and buoyancy and
causes deaths
Heavy oil sinks to ocean bottom
and washes into estuaries where it
contaminates crabs, oysters,
mussels, clams, etc.
Oil slicks on beaches harm
intertidal life and cause economic
losses to tourism and fishing
industries
Ocean Pollution:
Petroleum
• Petroleum is
biodegradable
• Many pollution experts
consider oil to be among
the least damaging
ocean pollutants
• Data from the 1989
Exxon Valdez oil spill
shows the recovery of
key organisms
bss.sfsu.edu/ehines/geog600/
Freshwater%20and%20ocean%20Pollution.ppt
BP Deepwater Horizon Oil Spill
April 24, 2010-Worst spill in US
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The Deepwater Horizon, a semi-submersible drilling rig, sank on April 22,
after an April 20th explosion on the vessel. Eleven people died in the blast.
When the rig sank, the riser—the 5,000-foot-long pipe that connects the
wellhead to the rig—became detached and began leaking oil. In addition,
U.S. Coast Guard investigators discovered a leak in the wellhead itself. As
much as 60,000 barrels of oil per day were leaking into the water,
threatening wildlife along the Louisiana
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BP (British Petroleum), which leased the Deepwater Horizon, is responsible
for the cleanup, but the U.S. Navy supplied the company with resources to
help contain the slick. Oil reached the Louisiana shore on April 30, affected
about 125 miles of coast. By early June, oil had also reached Florida,
Alabama, and Mississippi. It is the largest oil spill in U.S. history.
Some estimates say 205.8 million gallons!!!
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CASE STUDY: Exxon Valdez
• 2nd Worst oil spill in U.S.
history:
– March 24, 1989 from oil tanker
Exxon Valdez in Prince
William Sound, Alaska.
– Spilled 11.6 million gallons of
oil.
– 3000 miles of coastline
polluted.
– Killed 1000’s of birds,
mammals, plankton, etc.
– Exxon spent $2.2 billion on
direct cleanup + $1 billion
fines and damages
– Region will probably be
affected for 10-15 more years.
– Now, tankers must have
double hull to decrease
chance of spills.
Cleaning Up Oil Spills
1. Shoreline
•Wiping with paper towels
•Spraying back into sea w/high powered hose.
2. Open Ocean
•Drop boom to contain oil.
•Burn it off- causes air pollution
•Vacuum it up & separate
•Bioremediation- bacteria “eat” oil
Exxon Valdez only #53????
Where does BP oil spill rank?
bss.sfsu.edu/ehines/geog600/
Freshwater%20and%20ocean%20Pollution.ppt
Ocean Pollution: Sewage
Sludge
• Sewage sludge is
the semisolid
material that
remains after
sewage treatment
• Much sewage
sludge was dumped
offshore until laws
restricted sewage
dumping
Ocean Pollution: DDT
• DDT was a widely used
pesticide that became
concentrated in ocean fish
• DDT caused brown pelicans
and ospreys to produce thin
egg shells
• Worldwide, DDT has been
banned from agricultural use
but is still found in developing
countries…
• Same general problems with
PCB’s but these come from
industrial coolants, not
pesticide use
Plastic in the Ocean Environment
• Plastic:
– Either does not
biodegrade or not in
human time…
– Floats- sea turtles
mistake it for
jellyfish
– Has high strength
– Is ingested by and
entangles ocean
animals
Plastic Pollution
• http://www.montereybayaquarium.org/cr/o
ceanissues/plastics_albatross/
Plastic Alternatives
• Biodegradablebreakdown with
biological organism
like bacteria
• Photodegradablebreakdown with light
• Degradable- can be
broken down with
chemicals