Question

The BOD values for pure water and highly polluted water are respectively:

• A. \(>5 \, {ppm}, \leq 17 \, {ppm} \)
• B. \(>5 \, {ppm}, \geq 17 \, {ppm} \)
• C. \(<5 \, {ppm},>17 \, {ppm} \)
• D. \(<5 \, {ppm}, \leq 17 \, {ppm} \)

Hint:

BOD values provide insight into the level of organic pollutants in water. Pure water has a low BOD, while highly polluted water has a high BOD.

Answer 1

The Correct Option is C

BOD (Biochemical Oxygen Demand) is a measure of the amount of oxygen required by microorganisms to decompose organic matter in water. In pure water, the BOD value is low, typically less than 5 ppm, as it contains fewer organic pollutants. For highly polluted water, the BOD value is high, typically greater than 17 ppm, because of the increased amount of organic material present. 
Step 1: For pure water, the BOD is generally less than 5 ppm. For highly polluted water, the BOD is generally greater than 17 ppm. 
Step 2: Thus, the correct relationship between the BOD values for pure and highly polluted water is \(<5 \, {ppm},>17 \, {ppm} \).

Answer 2

The Biochemical Oxygen Demand (BOD) is an important parameter for assessing water quality, particularly in determining how polluted a body of water is. BOD measures the amount of oxygen that microorganisms require to decompose the organic matter present in water.

For different types of water, the BOD values generally differ:

• Pure Water: Typically has a BOD value of less than \(5 \, \text{ppm}\). This is because pure water contains minimal organic matter, thus requiring less oxygen for decomposition.
• Highly Polluted Water: Exhibits a BOD value greater than \(17 \, \text{ppm}\). The presence of a large amount of organic pollutants increases the oxygen demand for microbial decomposition.

Therefore, the correct relationship for the BOD values of pure water and highly polluted water is \(\lt 5 \, \text{ppm}, \gt 17 \, \text{ppm}\).