water pollution. types of pollution microbiological chemical oxygen depleting substances ...
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Oxygen Depleting Substances
Microorganisms that live in water feed on biodegradable substances.
When too much biodegradable material is added to water, the number of microorganisms increase and they use up the available oxygen. This is called oxygen depletion.
…Addition of biodegradable substance
O2
O2
O2
O2
# of microorganisms INCREASES…
..begin using up all the OXYGEN!!
Oxygen depletion
When oxygen levels in the water are lowered, relatively harmless aerobic microorganisms die and anaerobic microorganisms begin to thrive.
Some anaerobic microorganisms are
harmful to people, animals and the environment, as they produce harmful toxins such as ammonia and sulfides.
Suspended Matter
Some pollutants do not dissolve in water because their molecules are too big to mix between the water molecules.
This material is called particulate matter.
The suspended particles eventually settle and cause a thick silt at the bottom. This is harmful to marine life that lives on the floor of rivers or lakes.
Think about a typical day, when do we use water? (list as many examples as you can)
When we use water, what gets added to it before it returns to wherever it goes?
Where does our used water end up? How does it get there?
Sewage & Wastewater
Homes, industrial (factories) and agricultural (farming) practices produce wastewater that can cause pollution of many lakes and rivers.
Sewage is the term used for wastewater that often contains feces, urine & laundry waste
(soap/chemicals)
What happens to Sewage?
Sewage disposal is a major problem in developing countries as many people in these areas don’t have access to sanitary conditions and clean water. Toilets, sinks, running water (so plumbing)
Sewage & Pollution
In developed countries, sewage often causes problems when people flush chemical and pharmaceutical substances down the toilet/drain.
Microbial pollution
When people are ill, sewage often carries harmful viruses and bacteria into the environment that can eventually cause health problems for other organisms/people
Water Treatment:
The two main reasons for collecting and treating wastewater are to: prevent water-borne transmission of disease
preserve the aquatic environment.
Wastewater Treatment System The wastewater treatment
system has three major parts: collection, treatment, and return to the environment.
Collection:
The Collection System uses water to transport wastes to the treatment system.
This is accomplished through a complex network of pipes, tunnels and pumping stations.
At home, at school or at work, everyone contributes to the flow of wastewater. Household sources include bath, laundry,
toilet flushing, dishwashing, etc.