Which gas is known to be harmful and may be found in wastewater?

Hydrogen sulfide is a gas that can be found in wastewater and is known for its harmful properties. This gas is created during the decomposition of organic matter, especially under anaerobic conditions, which are commonly present in wastewater treatment processes. Hydrogen sulfide poses significant health risks, as it is toxic and can cause respiratory issues, irritation of the eyes and throat, and even more severe health effects at higher concentrations. Furthermore, it has a distinct rotten egg odor, which can serve as a warning sign, but it can also be deadly in high concentrations if not properly managed.

While oxygen and nitrogen are essential gases in biological processes and the environment, they do not carry the same harmful implications in the context of wastewater. Carbon monoxide, while also a toxic gas, is not typically associated with wastewater and is more commonly linked to combustion processes.