Which oxidant has the potential to produce chlorate (CLO3) by-products?

Chlorine dioxide is the correct oxidant associated with the potential to produce chlorate (ClO3) by-products during water treatment processes. When chlorine dioxide is used for disinfection or oxidation, it can undergo various chemical reactions, particularly in the presence of organic materials or certain conditions like high pH. One of those reactions can lead to the formation of chlorate as a by-product, especially when chlorine dioxide is used in excess or when it's subjected to certain environmental conditions.

Chlorate formation is a particular concern in water treatment, as it relates to water quality regulations and potential health implications. Knowing that chlorine dioxide, as a powerful oxidant, can result in chlorate production helps water treatment professionals manage and mitigate these by-products effectively, ensuring compliance with safety standards.

In contrast, while other substances listed might also have various reactions in water treatment processes, they do not lead to significant chlorate production. Ammonium hydroxide is primarily used for pH adjustment and does not oxidize to produce chlorate. Chlorine, though it produces other by-products like trihalomethanes when reacting with organic compounds, does not typically form chlorate as a primary by-product. Similarly, ozone, while an effective oxidant, mainly leads to