Transcript Water Pollution

Pollution
Pollution
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Can be described as any material or product
produced by humans in quantity and disposed
of in such a way that it interferes with the
health of living organisms and with the natural
environments and processes of Earth.
Causes
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Technological advancements of the industrial
age
Increase population densities associated with
urbanization
Types of Pollutants
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Persistent pollutants
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Materials that remain in the environment for many
years with out breaking down.
Made by humans and come from industrial
activity.
Stable and often toxic compounds
Ex. DDT (pesticide) PCB’s (polychlorinated
biphenyls) CFC’s (chlorofluorocarbons)
Types of Pollutants
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Non-persistent
pollutants
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Biodegradable (do not
remain in the
environment for long
periods of time)
Ex. Human waste, food,
compost
Some human-made
pesticides and chemical
compounds that break
down quickly
Air Pollution
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Two Types:
 Primary air pollutants
 Secondary air pollutants
Primary Air Pollutants
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Carbon dioxide – burning fossil fuels
Carbon monoxide – when burning fossil fuels
are not completely oxidized
Hydrocarbons – compound of hydrogen and
carbon (car exhaust and factory smokestacks)
Primary Air Pollutants
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Particulates – tiny pieces of debris that are
dispersed into atmosphere (asbestos, dust from
construction/demolition sites, mining)
Sulphur dioxide – when fossil fuels containing
sulphur are burned; creates suphurous acids
(factories, power plants)
Nitrogen oxides – form from burning fossil
fuels when combustion takes place in the air.
Reddish brown, smog
Secondary Air Pollutants
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Smog
 Industrial smog
 Photochemical smog
Industrial Smog
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Buildup of particles, smoke, and dust from
industries released into the air
Was common in the industrial cities of MDC’s
until emission-control regulations
An increasing problem in LDC’s because
many do not have pollution-control laws in
place
Photochemical Smog
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Yellowish-brown haze that forms over cites on
hot, calm days
Forms when nitrogen oxides and hydrocarbons
combine due to sunlight to create ozone and
PAN (peroxyacetyl nitrate)
Continue to build up due to “thermal
inversion”
Thermal Inversion
Acid Rain and Deposition
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Acid rain – burning of fossil fuels release compounds
containing oxides, sulphur and nitrogen into the
atmosphere which dissolve in cloud droplets and fall
to Earth
Acid Rain and Deposition
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Deposition – When sulphur and nitrogen particulates
travel through the atmosphere and fall kilometers
from their point of origin.
Effects of Acid Rain and Deposition
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Damage to many kinds of plants, especially new
growth.
Affects root systems (unable to get proper nutrients)
Plants have lower resistance to disease and weather
Effects of Acid Rain and Deposition
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Fish become “acidified” (Atlantic Salmon)
Acid causes metals (aluminum and mercury) to
“leach” into water. (toxic, Loons in Kejimkujik
Lake)
Corroding effect on stone and cement and
metal (cars)
Respiratory problems
Water Pollution
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For a long time people believed that the
Earth’s water resources were capable of
absorbing and purifying waste without
suffering damage.
Rivers – Rhine in Europe, Hudson in USA,
Vistula in Poland, Volga in Russia, and Ganges
in India – all large, all polluted.
Water Pollution
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Lakes – susceptible to pollution because they
do not have “outflows” or currents to wash
away pollutants.
Water Pollution
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Great Lakes system is seriously polluted. 1950’s
algal blooms (eutrophication), fish killed, floating
waste, oil slicks, foul odours, beach closures.
1972 “Great Lakes Water Quality Agreement”
Water Pollution
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Oceans – Polluted rivers flow into them. The
Rhine in Germany discharges 100t of toxic
heavy metals into the North Sea each year.
Pollutants are also directly discharged from
ships or from shores
Hazards of Water Pollution
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Disease-causing bacteria, viruses and protozoa
pose heath risks (Cholera, Hepititis)
Nitrogen and phosphorus cause algae blooms –
eutrophication
Sediment can suffocate fish and aquatic plants
Hazards of Water Pollution
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Oil spills kill fish, seabirds, aquatic animals
Synthetic chemicals and heavy metals are toxic
to many life forms – cause health problems
(congenital)
Waste Disposal
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Waste falls into three main categories:
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Domestic sewage
Solid waste
Toxic and hazardous waste
Domestic Sewage
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Anything passing through toilets, sinks,
showers, and bathtub drains.
Until the “Harbour Solutions Project” raw
sewage was dumped straight into Halifax
Harbour
Some municipalities “treat” their sewage first
– remove solids, add chemicals/bacteria
Solid Waste
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The waste that goes to landfills, gets
incinerated, or recycled
“packaging revolution”
Solid Waste
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Landfills – used to be holes in the ground
where disease, odour, and chemical leakage
happened regularly
Now landfills are “sanitary” pits lined with
impermeable material to prevent leakage.
Waste is compacted and layered with soil.
Recycling
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Lifestyle commitment – reduce, reuse, recycle
Infrastructure needed – containers, labour,
vehicles, sorting, storage.
Affects other industries (ex. recycling paper
affects pulp and paper mills)
Hazardous and Toxic Waste
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Hazardous waste - any materials that have
dangerous properties (ex. flammable,
explosive, health risks)
Toxic waste – materials that are poisonous.
Mining, metal smelting, laboratories, hospitals
Hazardous and Toxic Waste
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No satisfactory way of managing or getting rid
of them
1980’s MDC’s shipped millions of tonnes of
waste to LDC’s who accepted it for financial
gain
Hazardous and Toxic Waste
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MDC’s dispose of H&T waste in the following
ways:
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Dump them into sanitary landfills (not designed
for them)
Discharge untreated or partially treated waste into
water (sewers, streams, rivers, lakes)
Use high-pressure injections to force waste into
deep wells (under ground)
Hazardous and Toxic Waste
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MDC’s dispose of H&T waste in the following
ways:
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Store in pits, ponds or lagoons (Sydney Tar Ponds)
Place in specially designed dumps and cover with
soil
Store in containers in abandoned mines or other
underground caverns
Hazardous and Toxic Waste
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Thermal testament – burn it at high
temperatures. Costly, causes dangerous fumes,
and you are still left with the ash to dispose of.
Neutralization – neutralize with chemicals
(acid and alkaline), micro-organisms, or
bacteria. Some waste can be reused by another
industry.