Recovery of the sludge of a wastewater treatment plant by anaerobic digestion and biogas production

The aim of our research work is the realization of anaerobic digestion by using the organic sludge of the urban wastewater treatment plant as a substrate.The biodegradable nature of the wastewater sludge allowed flammable biogas to be recovered after 24 hours of digestion and biogas production reached almost 5 liters for an initial concentration of 70 g / L The rate of reduction in COD (chemical demand in oxygen) of the sludge was estimated at 87.3% .For the good functioning of the digestion one must control the following parameters: type of substrate, pH of the medium, the organic load expressed in COD or BOD, the temperature.Once the operation is conducted we must follow the VFA / CAT (Volatile Fatty Acid/ Complete Alcalimetric Title) parameter which shows if the process will continue or will be stopped.And finally, the C / N ratio gives us an indication if there is more carbon in the medium, this will indicate that the residence time is going to be very long in the reactor and if nitrogen is abundant in the organic matter it is will produce in the digestion medium ammonia which inhibits the degradation process and stops it in the acidogenic phase and the production of biogas.The use of anaerobic digestion can be an interesting solution to dispose of energy from organic waste, while effectively participating in the remediation of these effluents.This renewable energy, inexpensive, non-polluting can replace conventional and nonrenewable fossil fuels.