Multiple choice

Which of the following techniques cannot be used to make water germ free?

  1. Chlorination

  2. Sedimentation

  3. Ultraviolet purification

  4. By boiling

  5. Ozone treatment

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Depletion of oxygen is caused by different pollutions like chemical contamination, garbage contamination, and agricultural contamination, which kills aerobic bacteria that are eco friendly and develops anaerobic bacteria which are harmful bacteria.