Which process significantly reduces pathogens in Class B biosolids?

Anaerobic digestion is a biological process that breaks down organic material in the absence of oxygen, which effectively reduces the number of pathogens in Class B biosolids. During this process, microorganisms decompose organic matter, resulting in a significant reduction of harmful bacteria and viruses. This not only aids in pathogen control but also stabilizes the biosolids, making them safer for certain agricultural applications.

Class B biosolids are treated to a level where they can be safely used in land applications, but they still contain some pathogens, hence the need for effective treatment processes like anaerobic digestion. This method also produces biogas, which can be captured and used for energy purposes, contributing to a more sustainable waste management system.

Other processes listed, such as aerobic digestion and thermal conditioning, also serve to treat biosolids but may not achieve the same level of pathogen reduction as anaerobic digestion within the framework of Class B biosolids regulations. While centrifugation is important for separating solids and liquids, it does not significantly reduce pathogens by itself without accompanying biological treatment processes.