By what percentage can digestion reduce the total mass of biosolids?

Digestion is a crucial process in wastewater treatment, particularly for the reduction of sludge or biosolids. The process involves breaking down organic materials in the biosolids through anaerobic or aerobic digestion, leading to a significant reduction in the total mass of these solids.

Typically, digestion can effectively reduce the total mass of biosolids by around 40%. This reduction occurs as microorganisms consume and decompose the organic matter within the sludge, resulting in the generation of biogas, primarily methane and carbon dioxide, which is then released. What remains after digestion is a more stabilized product that is less odorous and has lower pathogen levels, making it easier to handle and possibly more suitable for land application or further processing.

While some digestion processes may reduce biosolid mass by less than this amount, the commonly referenced percentage for effective digestion, indicating a well-managed process, is 40%. Therefore, this answer accurately reflects the typical outcomes of biosolid digestion in wastewater treatment systems.