Q168
General ScienceEnvironment & Ecology
Water purity is denoted by the absence of
- a.CO$_2$
- b.CO
- c.Coliform
- d.Entero bacter
Answer: (C) Coliform
Coliform bacteria are the standard indicator of faecal contamination, so their absence is used to certify drinking water as pure. Dissolved CO$_2$ is harmless, CO is not a water-quality test, and Enterobacter is just one genus within the coliform group.