What is the effect of nitrite presence in final effluent on disinfection?

The presence of nitrite in final effluent significantly impacts disinfection because it increases chlorine demand. Chlorine is commonly used as a disinfecting agent in wastewater treatment to kill pathogenic microorganisms. When nitrite is present in the effluent, it reacts with chlorine, which can lead to a higher consumption of chlorine to achieve the same level of disinfection.

This increased demand for chlorine can necessitate the addition of more chlorine than would normally be required in the absence of nitrite, making the disinfection process less efficient and potentially compromising the effectiveness of pathogen removal. Properly accounting for the presence of nitrite is crucial for operators to ensure that adequate disinfection is achieved, which aligns with regulatory standards for treated wastewater.

In contrast, other effects such as increased bacterial growth, decreased chlorine demand, and neutralization of chlorine do not accurately describe the role of nitrite in the disinfection process in wastewater treatment.