Anaerobic processes refer to biological processes that occur in the absence of oxygen. These processes are carried out by anaerobic microorganisms that can survive and thrive in oxygen-free environments. Anaerobic digestion is a well-known anaerobic process that breaks down organic matter into biogas and digestate. This process is commonly used in wastewater treatment, solid waste management, and biogas production. Additionally, anaerobic fermentation is another anaerobic process used in the production of biofuels and chemicals. Overall, anaerobic processes play a crucial role in various environmental and industrial applications.