Correct Answer: Option A - 2 and 3 only
Biodegradable pollutants are always harmless in any quantity. - This statement is False. Biodegradable pollutants can be harmful when present in excess quantities, even though they can eventually break down naturally. For example, excessive organic waste in water bodies can deplete oxygen levels and harm aquatic life before being fully degraded.
They can cause pollution if present in excess amounts. - This statement is True. Even though biodegradable pollutants can be broken down by natural processes, when they exceed the environment's capacity to degrade them quickly enough, they cause pollution. Examples include sewage discharge, agricultural runoff, or food waste that overwhelm natural systems.
Microorganisms play a key role in degrading biodegradable pollutant - This statement is true. Bacteria, fungi, and other microorganisms are the primary agents that break down biodegradable materials through processes like decomposition, fermentation, and oxidation.