Waste water treatment:

Question 1

What does waste water contain?

Answer 1

= large amount of organic molecules.
= microorganisms.
= must be craefully treated before being released into an envrioment.

Question 2

How is waste water treated?

Answer 2

= screened by passing through mesh- removes solids and grit

= settled in large sedimentation tanks- produces a liquid effluent + semi-solid sludge that sinks

Question 3

What happens to the ‘sludge’?

Answer 3

= digested by anaerobic bacteria
=can be used as fertilisers and farming
= absence of oxygen: bacteria produce biogas can be burned for electricity

Question 4

What happens to the liquid ‘effluent’?`

Answer 4

= contains organic molecules + harmful microorganisms
= reduced before returned
= air is bubbled through- allows aerobic bacteria to multiply
= pressence of oxygen: aerobic bacteria digest the organic molecules + harmful microorganisms/
= water is released into river and streams``

Question 5

How is water used in industry treated?

Answer 5

FIRST: harmful chemicals need to be removed
= enter general sewage treatment
=