Which of the following are typical steps involved in tertiary treatment?

The correct answer involves typical steps found in tertiary treatment, which targets the final stage of wastewater treatment. Tertiary treatment is designed to improve the quality of effluent by removing residual contaminants that remain after primary and secondary treatment processes.

Nutrient removal is a key step in this stage, specifically aimed at reducing nitrogen and phosphorus levels to prevent issues like algae blooms in receiving water bodies. Disinfection is another essential component, commonly performed using methods such as chlorination, ultraviolet light, or ozonation, to eliminate pathogens and ensure that the treated water is safe for discharge or potential reuse.

While filtration and BOD reduction are important aspects of wastewater treatment, they are generally associated with earlier treatment stages. Pre-treatment and aeration also pertain to initial phases that focus on the preliminary removal of solids and organic load. Raw sewage pumping and screening are foundational tasks meant for the primary stage, dealing with the inflow of raw sewage. Overall, tertiary treatment specifically emphasizes polishing the effluent through nutrient removal and disinfection to achieve higher water quality standards.