Question

Water pollution can be identified by testing its
A) pH level
B) Biological Oxygen Demand (BOD)
C) Both a and b
D) None of these

Answer 1

Hint: The water pollution can be measured by acidity or basicity of water and the amount of oxygen dissolved in it.

Complete answer:
The contamination of water bodies is known as water pollution which occurs due to human activities. The water samples are analyzed to measure the amount of water pollution present in them. The most frequently used method is pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), nutrients, metals, etc.
Additional information
-The water samples are first collected and then followed by analytical tests.
-A sampling of water is simply dependent upon the characteristic of contaminants.
-Biochemical oxygen demand (BOD) is the amount of dissolved oxygen that is required by biological organisms to break down organic material under aerobic conditions.
-The increase in BOD means the increase in dead and decaying matters thus resulting in enough oxygen being dissolved. The more the BOD, the less is the oxygen required.
-pH level also measures the water pollution, as the pH drops, the weak plants and animals will die. The higher the pH the more basic water will be while the lower the pH the more acidic water will be.
-The more pollution will be the more the water will be acidic.

So, the correct answer is ‘Both a and b'.

Note: The measurement of water pollution can also be done by several other testings which include: physical, chemical, and biological testing. Physical testing can be done by temperature, solid concentrations while biological testing involves the use of the plant, animal, or microbial indicators. The chemical testing involves the presence of organic substances and the number of minerals present in the water bodies affecting the quality of water.