Which practice is used to free contaminated water of bacteria?

• A. Filtering.
• B. Passing it through Charcoal.
• C. Treating It With Chlorine.
• D. Allowing It To Settle.

Answer: (C)

Disinfection is the key idea here. Chlorine works because it forms hypochlorous acid in water, which penetrates bacterial cells and oxidizes essential enzymes and membranes. This disrupts metabolic processes and kills the bacteria, often with a residual effect that defensively protects the water from future contamination.

Filtration removes particles and can reduce some microbes, but it doesn’t reliably kill all bacteria unless the filter is extraordinarily fine and properly maintained. Charcoal filtration mainly adsorbs chemicals and improves taste and odor, not a guaranteed kill of bacteria. Letting water settle cleans out some solids, but bacteria can still be present, especially if they’re free-floating.