Biochemical Oxygen Demand (B.O.D.): What is the permissible value of B.O.D. in safe drinking water according to environmental engineering standards?
Civil Engineering
Water Supply Engineering
Difficulty: Easy
Choose an option
-
ANil
-
B5
-
C10
-
D15
-
E20
Answer
Correct Answer: Nil
Explanation
Introduction / Context:B.O.D. measures the oxygen consumed by microorganisms while decomposing organic matter in water. In safe drinking water, B.O.D. should ideally be zero to ensure purity and safety.
Given Data / Assumptions:
- B.O.D. values indicate pollution levels.
- Standards prescribe safe limits for potable water.
Concept / Approach:B.O.D. is critical for wastewater quality but should be absent in drinking water. Hence, safe drinking water must have nil B.O.D.
Step-by-Step Solution:
1. Identify water type → drinking water.2. Standard → B.O.D. should be absent.3. Hence, permissible value = Nil.Verification / Alternative check:BIS standards confirm B.O.D. must be nil in potable water, while wastewater may allow measurable values.
Why Other Options Are Wrong:
- 5, 10, 15, 20: These values are acceptable for wastewater, not drinking water.
Common Pitfalls:
- Confusing wastewater B.O.D. with drinking water standards.
Final Answer:Nil