In drinking water treatment, what is the correct process term for intentionally killing disease-causing organisms (pathogens) in water while not necessarily achieving complete sterilization of all forms of life?

Introduction / Context:
In municipal and industrial water treatment, we aim to supply safe water by inactivating microorganisms that cause disease. The technical term used for this targeted microbial control step is often confused with other unit processes like coagulation or sedimentation. This question checks whether you can distinguish the purpose and scope of disinfection from related processes and from the more absolute concept of sterilization.

Given Data / Assumptions:

• Context is potable water treatment.
• Goal is to kill or inactivate pathogens to make water safe.
• Complete elimination of all life is not required in routine potable treatment.

Concept / Approach:
Disinfection is the targeted inactivation of pathogens (bacteria, viruses, protozoa). Sterilization means destruction of all forms of microbial life including spores, which is not economical or necessary for drinking water. Coagulation and sedimentation remove particles but do not reliably kill pathogens.

Step-by-Step Solution:

Verification / Alternative check:
Typical disinfectants include free chlorine, chloramines, chlorine dioxide, ozone, and UV radiation. Regulatory frameworks use CT (concentration * time) or UV dose to verify adequate disinfection, not sterilization.

Why Other Options Are Wrong:
Coagulation: Aggregates fine particles; does not kill reliably.
Sterilization: Implies total kill including spores; unnecessary in drinking water practice.
Sedimentation: Settles floc; does not provide pathogen inactivation by itself.

Common Pitfalls:
Assuming clarification equals microbial safety; equating disinfectant residual with complete sterilization; overlooking the need to maintain a small disinfectant residual in the distribution system to control regrowth.

Final Answer:
Disinfection