To avoid the instability and failure of anaerobic digestion, a process of monitoring and controlling is strongly required. State indicators including biogas yield, methane content, hydrogen (H2), hydrogen sulphide (H2S), pH, total volatile fatty acids (TVFAs) and individual volatile fatty acids were studied under different types of load disturbances in order to find the most effective indicator(s). During load disturbances, biogas yield increased quickly in response to the easily degradable compounds while slowly to the complex compounds. Relat...
