Question

Biochemical Oxygen Demand, $(BOD)$ is a measure of organic material present in water. $BOD$ value less than $5\, ppm$ indicates a water sample to be_______.

• A. rich in dissolved oxygen
• B. poor in dissolved oxygen
• C. highly polluted
• D. not suitable for aquatic life

Answer 1

Answer: (A)

rich in dissolved oxygen

Answer 2

Clean water rich in dissolved oxygen would have $BOD$ value of less than $5\,ppm$ whereas highly polluted water could have a $BOD$ value of $17\,ppm$ or more.