Waste Water Treatment

This lesson covers:

  1. The three main sources of waste water: households, agriculture, and industry 
  2. The different stages of waste water treatment
  3. What happens to the water after it's been treated

Is nutrient run-off from fields an example of domestic, agricultural, or industrial waste? 

Agricultural 

Domestic

Industrial 

0

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1

Is used shower water an example of domestic, agricultural, or industrial waste? 

Domestic

Agricultural 

Industrial 

0

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1

Illustration of a test tube containing an orange chemical substance.

Are the chemicals released from manufacturing factories an example of domestic, agricultural, or industrial waste? 

Domestic

Agricultural 

Industrial 

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1

True or false? Waste water is usually returned to the environment without processing.

True

False

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1

Which two of the following are removed from sewage and agricultural waste water before the water is returned to the environment?

Salts

Organic matter

Harmful microbes

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2

Steps in the treatment of sewage


sealed / oxygen / nitrogen / large / effluent / sludge


  1. Screening - The sewage is passed through gratings and meshes to remove anything .
  2. Sedimentation - The sewage is left to sit in a settlement tank, so that the heavier particles settle at the bottom as , while the lighter particles settle at the top as . 
  3. Aerobic digestion - Air is pumped through the effluent to supply the bacteria with
  4. Anaerobic digestion - The sludge is in a container to prevent the entry of air, which ensures anaerobic respiration. 
large
sludge
effluent
oxygen
sealed

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5

Which gaseous product does the anaerobic digestion of sludge produce?

Oxygen

Sulfur dioxide

Nitrogen

Methane

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True or false? Anaerobic digestion of sludge results in fertiliser that be spread on fields.

True

False

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1