Which bacteria is widely used as an indicator of wastewater disinfection effectiveness?

Fecal coliform bacteria are widely used as an indicator of wastewater disinfection effectiveness due to their association with fecal contamination. This group of bacteria, which primarily includes species such as Escherichia coli, is commonly found in the intestines of warm-blooded animals. Their presence in water indicates that human or animal waste has entered the water supply, suggesting a potential risk for pathogens that could pose a health threat to humans.

The use of fecal coliform as an indicator is grounded in several key factors: they are relatively easy to detect, their levels correlate well with the presence of other harmful microorganisms that may not be easily tested for, and they typically respond to the same disinfection methods used to treat wastewater. By monitoring fecal coliform levels after disinfection processes, operators can gauge the effectiveness of those processes in removing pathogens from the wastewater.

While Escherichia coli is indeed a member of the fecal coliform group and is also used as an indicator, fecal coliform encompasses a broader range and is thus the primary term used for this purpose. The other bacteria listed—Salmonella and Staphylococcus—are not used as standard indicators of wastewater disinfection effectiveness due to their specific pathogenic behaviors and the complexity