Ozonation in drinking-water treatment: select the incorrect statement about the effects of ozone on water quality.

Introduction / Context:
Ozone is a strong oxidant used in advanced drinking-water treatment for primary disinfection and control of taste-and-odour-causing compounds. It decomposes rapidly, leaving no long-lived residual in distribution.

Given Data / Assumptions:

• Properly applied ozone doses within conventional treatment trains.
• Downstream filtration and, if needed, a secondary disinfectant (e.g., chloramine) may be applied.

Concept / Approach:
Ozone effectively inactivates many microbes and oxidizes certain organics, improving taste and odour. However, it does not render water “tasteless”; rather, it removes off-flavours without imparting a chlorine-like taste since it leaves minimal residual.

Step-by-Step Assessment:

Verification / Alternative check:
Utility practice shows ozonated water is often described as “fresh” without chlorine taste, not “tasteless”.

Why Other Options Are Wrong:

• (a), (b), and (e) are generally true within standard practice.
• (d) “None of these” is false because (c) is indeed incorrect.

Common Pitfalls:
Confusing absence of chlorine taste with the notion of tasteless water; minerals and temperature still influence taste.

Final Answer:
Ozonised water becomes tasteless