Anaerobic digestion is a biological process that uses microorganisms to break down organic matter in the absence of oxygen. The microorganisms involved in this process include various types of bacteria and archaea that can degrade complex organic compounds into simpler molecules such as methane, carbon dioxide and other volatile fatty acids.
The anaerobic digestion process involves several distinct stages.
Hydrolysis: The complex organic matter in the waste is broken down into smaller molecules, such as sugars, by hydrolytic bacteria.
Acidogenesis: The smaller molecules produced in the hydrolysis stage are further degraded into volatile fatty acids and other organic acids by acidogenic bacteria.
Acetogenesis: The organic acids produced in the acidogenesis stage are converted into acetic acid and other short-chain fatty acids by acetogenic bacteria.
Methanogenesis: The final stage of anaerobic digestion involves the conversion of acetic acid and other short-chain fatty acids into methane and carbon dioxide by methanogenic bacteria.
