Question

According to drinking water standards, the desirable residual chlorine at the consumer end is about

• A. \(0.05\ \mathrm{mg/L}\)
• B. \(1.5\ \mathrm{mg/L}\)
• C. \(0.2-0.5\ \mathrm{mg/L}\)
• D. \(5\ \mathrm{mg/L}\)

Hint:

Recommended residual chlorine: \[ \boxed{ 0.2-0.5\ \mathrm{mg/L} } \] at the consumer end after at least 30 minutes of contact time.

Answer 1

The Correct Option is C

To ensure effective disinfection and protect against microbial contamination, drinking water should maintain a residual chlorine concentration of about \[ 0.2\text{ to }0.5\ \mathrm{mg/L} \] at the consumer's tap. Hence, \[ \boxed{0.2-0.5\ \mathrm{mg/L}} \] is the correct answer. Therefore, \[ \boxed{(C)} \]