Question

Water sample is called cleanest on the basis of which one of the BOD values is given below.

Options

• 11 ppm

• 15 ppm

• 3 ppm

• 21 ppm

Answer 1

3 ppm

Explanation:

A BOD value of less than 5 ppm indicates clean water, whereas a BOD value of 17 ppm or higher indicates highly polluted water.