Which water quality parameter is primarily used to evaluate the effectiveness of disinfection?

The evaluation of disinfection effectiveness primarily relies on the presence of coliform bacteria. Coliforms are a group of microorganisms often found in the environment, including soil, on plants, and in the feces of warm-blooded animals. Their presence in water is an indicator of fecal contamination and the potential presence of pathogenic microorganisms that can cause disease.

When a wastewater treatment plant utilizes disinfection methods, such as chlorination or ultraviolet (UV) light, the goal is to reduce or eliminate these harmful pathogens. Monitoring the levels of coliform bacteria after disinfection provides a clear indication of how well the disinfection process has worked. If coliform levels are significantly reduced or eliminated, it suggests that the disinfection process is effectively killing or inactivating pathogens.

In contrast, other parameters like Biochemical Oxygen Demand (BOD), pH, and Total Suspended Solids (TSS) are essential for assessing different aspects of water quality but do not directly measure the effectiveness of disinfection. BOD measures the amount of oxygen consumed by microorganisms in the water, which reflects organic matter levels rather than pathogen presence. pH indicates the acidity or alkalinity of the water, which can influence the efficiency of certain disinfection processes but does not serve