OPTIMIZATION OF BIOGAS PRODUCTION IN WASTEWATER TREATMENT PROCESS WITH MEMBRANE BIOREACTOR

The future wastewater treatment process should be more cost-effective and removal efficiency of environmentally harmful compounds better in comparison with the existing wastewater treatment plants. Anaerobic digestion of sludge to biogas (methane) is important part of the treatment chain. After anaerobic digestion treated sludge could be utilized e.g. as a fertilizer. Producing methane with high current efficiency needs optimizing of anaerobic digestion process. In this study primary sludge (pre-clarified sludge) produced in wastewater treatment plant and sludge produced by membrane bioreactor (MBR) were digested in wet process. It was observed that pre-clarified sludge could produce the highest amounts of biogas and methane during the experiments. MBR sludge and combination of pre-clarified sludge and MBR sludge could not produce as high amounts of biogas and methane. However, methane/biogas ratio was the highest with MBR sludge.