What process uses anaerobic bacteria to stabilize sludge?

Anaerobic digestion is the correct process that uses anaerobic bacteria to stabilize sludge. In this treatment method, organic matter in the sludge is broken down by bacteria in an oxygen-free environment. This process not only reduces the organic content of the sludge but also generates biogas, which consists mainly of methane and carbon dioxide. This biogas can then be captured and used as a renewable energy source.

The anaerobic digestion process also results in a stabilized solid material, which can be further processed for use as a fertilizer or soil amendment. This stabilization is vital in reducing odors, pathogens, and the volume of waste, making it more manageable for disposal or further treatment.

In contrast, aerobic digestion relies on oxygen and different types of bacteria to break down organic material, while composting involves aerobic processes typically using yard waste or food scraps. Filtration is a physical separation process separate from biological treatment methods and does not utilize bacteria for stabilizing sludge.