treating waste water

Question 1

what has to be done to waste water to be released back to the environment

Answer 1

Harmful chemicals and organic matter muse be removed before it is released back into the environment.

Question 2

what is the process of treating waste water

Answer 2

1.goes through the sewage system

2. goes through screening and grit removal (removes objects such as rags, paper, plastics, and metals to prevent damage and clogging of downstream equipment, piping, and appurtenances.)
3. and sedimentation (the process of separating small particles and sediments in water.)
4. then it splints 2 ways 1 to liquid effluent and one to sludge
5. liquid effluent; water goes through aerobic treatment
6. sludge(solid): treated by anaerobic digestion