Question

Arrange the processes involved in a correct sequence that is followed in the wastewater treatment plant.

• A. Chemical $\to$ biological $\to$ physical
• B. Biological $\to$ chemical $\to$ physical
• C. Physical $\to$ biological $\to$ chemical
• D. Biological $\to$ physical $\to$ chemical

Answer 1

The correct option is C Physical $\to$ biological $\to$ chemical

Wastewater treatment is the process of removing harmful contaminants from water. Physical, chemical and biological processes are used to treat wastewater.

Wastewater treatment starts with screening and followed by removal of sand and grit which are physical processes. It is then followed by biological process where waste is decomposed by bacteria.

Finally, it is treated with chemicals like chlorine to disinfect water before releasing water to natural waterbodies. Hence, correct sequence is physical, biological and then chemical.