NOVELTY - Modular bioreactor comprises a pre-fabricated container module, a main container, a flute-type supply system for wastewater and deposit of biological sludge, lower part purge or evacuation system of excess sludge, an acquisition or compartment separator biogas, internal clarifier sludge to the clarified water outlet in the upper part uptake system of clarified effluent, conduction system of biogas and biogas filtration (odor control), and system for sludge level measurement, all the above in a sealed container.    USE - The modular bioreactor is useful for burning biogas which is selectively taken in or compartment separator for capturing biogas and conducted in duct system and filtering biogas (claimed). Generally, it can be used for treatment of domestic and/or industrial wastewater.    ADVANTAGE - A pre-fabricated, fully-sealed, modular anaerobic biological system for the treatment of domestic and/or industrial wastewater, which is portable, lightweight and easy to transport and install, takes up very little space and can be installed in the form of multiple modules in parallel for projects that exceed the individual modular capacity is provided. The system can be used to remove between 75 and 85% of contaminants from domestic wastewater, as well as a similar percentage in the case of industrial wastewater, depending on the type of wastewater being treated, without requiring the use of electricity.    DETAILED DESCRIPTION - Modular bioreactor comprises a pre-fabricated container module, a main container, a flute-type supply system for wastewater and deposit of biological sludge, lower part purge or evacuation system of excess sludge, an acquisition or compartment separator biogas, internal clarifier sludge to the clarified water outlet in the upper part uptake system of clarified effluent, conduction system of biogas and biogas filtration (odor control), and system for sludge level measurement, all the above in a sealed container constructed from high density polyethylene and/or low density polyethylene, polypropylene, polyvinyl chloride (PVC), fiberglass or any thermoplastic, either by rotational molding, extrusion or any prefabrication technique and/or thermoplastic welding.