Lesson 4: Waste Water Treatment

Question 1

True or False

Waste water can be released into environment without being treated.

Answer 1

• False!!
• Waste water must be treated before being released into the environment.

Question 2

What **2 main things ** produce a large amount of waste water?

Answer 2

1.) Urban lifestyles.
2.) Industrial processes.

Question 3

What 2 things need to be removed from sewage waste water and agricultural waste water?

Answer 3

1.) Organic matter.
2.) Harmful microbes.

Question 4

What may industrial waste water require the removal of…?

Answer 4

1.) Organic matter.
2.) Harmful chemicals.

Question 5

What are the 4 main steps of **sewage treatment? **

Answer 5

1.) Screening/ grit removal.
2.) Sedimentation to produce sewage sludge and effluent.
3.) anaerobic digestion of sewage sludge.
4.) Aerobic biological treatment of effluent.

Question 6

What is the relative ease of obtaining potable water from: waste, ground and salt water?

Answer 6

• Sewage treatment requires more processes than treating fresh water.
• Sewage treatment uses less energy than the desalination/ distilation of salt water so could be used in areas where there isn’t much fresh water.