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C10: Quiz 5 – Answers
C10: Quiz 5 – Answers
1)
a) Sewage is wet waste from homes and industry
b) Organic matter, chemicals and harmful pathogens
c) Industrial sewage contains chemicals in greater quantities so requires more stages to be treated
2)
a) The screen removes grit and large objects (debris)
b)
i) Sedimentation
ii) Effluent
iii) Sludge
c)
i) Oxygen
ii) The bacteria break down all of the organic matter in the effluent
iii) The products are released into water ways (rivers and the sea)
d)
i) Lack of oxygen
ii) The products are:
a) Sewage is wet waste from homes and industry
b) Organic matter, chemicals and harmful pathogens
c) Industrial sewage contains chemicals in greater quantities so requires more stages to be treated
2)
a) The screen removes grit and large objects (debris)
b)
i) Sedimentation
ii) Effluent
iii) Sludge
c)
i) Oxygen
ii) The bacteria break down all of the organic matter in the effluent
iii) The products are released into water ways (rivers and the sea)
d)
i) Lack of oxygen
ii) The products are:
- Methane – that can be used as a fuel (heat a home or cook food)
- Fertilisers – they can be spread on crops to increase the growth of the crops
Questions
1)
a) What is sewage?
b) What 3 substances need to be removed from sewage before it enters into water ways?
c) Why are there more stages when treating industrial sewage compared to household sewage?
2) This question is all about the treating of sewage.
a) The first step in treating sewage is that the sewage passes through a screen; why?
b) After passing through the screen, the sewage enters a settling tank where the contents of the sewage settle.
i) What is the name of this process?
Whilst the sewage is in the settling tank, the sewage settles and splits into two.
ii) What is the name of the stuff that settles at the top of the settling tank?
iii) What is the name of the stuff that settles at the bottom of the settling tank?
c) The stuff that settles at the top of the settling tank enters another tank that contains bacteria that engage in aerobic digestion.
i) Air is pumped through this tank; what gas in air is required for aerobic digestion?
ii) What do the bacteria do in the tank?
iii) After the aerobic digestion has taken place, where are the products released?
d) The stuff that settles at the bottom of the settling tank enters another tank (a different tank to the stuff that settles at the top of the settling tank). This tank contains bacteria that engage in anaerobic digestion.
i) What gas does there need to be a lack of for anaerobic digestion to take place?
ii) This process produces 2 products. Give the names and uses of the two products.
1)
a) What is sewage?
b) What 3 substances need to be removed from sewage before it enters into water ways?
c) Why are there more stages when treating industrial sewage compared to household sewage?
2) This question is all about the treating of sewage.
a) The first step in treating sewage is that the sewage passes through a screen; why?
b) After passing through the screen, the sewage enters a settling tank where the contents of the sewage settle.
i) What is the name of this process?
Whilst the sewage is in the settling tank, the sewage settles and splits into two.
ii) What is the name of the stuff that settles at the top of the settling tank?
iii) What is the name of the stuff that settles at the bottom of the settling tank?
c) The stuff that settles at the top of the settling tank enters another tank that contains bacteria that engage in aerobic digestion.
i) Air is pumped through this tank; what gas in air is required for aerobic digestion?
ii) What do the bacteria do in the tank?
iii) After the aerobic digestion has taken place, where are the products released?
d) The stuff that settles at the bottom of the settling tank enters another tank (a different tank to the stuff that settles at the top of the settling tank). This tank contains bacteria that engage in anaerobic digestion.
i) What gas does there need to be a lack of for anaerobic digestion to take place?
ii) This process produces 2 products. Give the names and uses of the two products.