Besides disinfection, what other purposes does chlorine serve in public water systems?

Chlorine serves several important functions in public water systems beyond its well-known role in disinfection. By choosing the option that encompasses all listed purposes, it highlights the versatility of chlorine as a chemical treatment agent.

Chlorine is effective in taste and odor control by reacting with various compounds present in the water. When certain organic materials and compounds are present, they can impart unpleasant tastes and odors. Chlorine helps to oxidize these compounds, thereby improving the overall quality of drinking water.

Additionally, chlorine plays a critical role in the oxidation of iron. Iron often exists in water as dissolved ferrous iron, which can lead to staining and undesirable tastes. Chlorine can oxidize ferrous iron to ferric iron, which can then be precipitated out, effectively removing it from the water.

Chlorine's ability to oxidize hydrogen sulfide is another application. Hydrogen sulfide produces a rotten egg odor and can be harmful at high concentrations. Chlorine oxidizes hydrogen sulfide, converting it into sulfate, which is neither harmful nor odorous.

By recognizing all these functions together, it's clear that chlorine is a multifaceted treatment option in public water systems, addressing various water quality issues while ensuring it remains safe for consumption.