Anaerobic membrane bioreactor or AnMBR is the name of a technology utilized in wastewater treatment. AnMBR works by using a membrane bioreactor (MBR). The sewage is filtered and separated leaving the effluent and sludge apart. This sludge is treated anaerobically by mesophilic bacteria which release methane as a byproduct. The biogas can later be combusted to generate heat or electricity. AnMBR is considered to be a sustainable alternative for sewage treatment because the energy that can be generated by the methane combustion can exceed the energy required for maintaining the process.