For as long as anybody can remember, anaerobic handling has been used to separate various substrates, including sewage sludge. We both agree that an anaerobic digester is the best option because it uses a gas engine to burn methane to produce energy. Since then, endlessly seemingly forever, anaerobic handling has been used to isolate many substrates, including sewage sludge. We both agree that an anaerobic digester is the best option because it uses a gas engine to burn methane to produce energy. In India, anaerobic assimilation is essentially always possible, and it will most likely occur when the temperature is higher than 25 °C.