In wastewater treatment, what type of system often uses anaerobic digesters?

Anaerobic digesters are commonly used in secondary treatment systems because they are specifically designed to treat wastewater that has already undergone primary treatment. In this context, secondary treatment focuses on the removal of dissolved and suspended organic matter, and anaerobic digestion is a biological process that breaks down organic material in the absence of oxygen. This process not only helps reduce the volume of sludge produced during wastewater treatment but also generates biogas, which can be used for energy production.

In contrast, the other types of systems do not primarily utilize anaerobic digesters. Aerobic treatment systems operate with oxygen and involve different biological treatment processes. Preliminary treatment systems are focused on the initial screening and removal of large solids from the influent. Primary treatment systems primarily deal with the settling of solids and floating materials, allowing for the removal of larger particles but not leveraging the anaerobic digestion process for further treatment. Therefore, secondary treatment systems are best suited for the use of anaerobic digesters.