KUBOTA Submerged Membrane Unit (Kubota SMU)

is applied to multiple wastewater treatment processes including domestic/rural, sewage and industrial all over the world. The flow pattern across the membrane is a cross-flow type, separating the mixed liquor into permeate (treated water) and activated sludge. The membrane unit consists of a diffuser case and a membrane case (membrane case incorporates multiple membrane cartridges).  

The nominal pore size of the membrane sheet is 0.4 µm, by which not only activated sludge but also coliform bacteria and virus can be shut out. The mixed liquor from the biological treatment with maximum MLSS of 20 000 mg/litre (in the case of ES and EK series) can be separated clearly into solid and liquid. It assures almost 100% removal of SS and no carryover of SS into the effluent.

This process, therefore, assures stable treated water quality, which enables the treated water to be reused as reclamation water, often without the needs of post-MBR treatment. 


KUBOTA Submerged Membrane Unit System removes not only SS but also substances difficult to biodegrade such as detergent, by taking advantage of its longer Sludge Retention Time (SRT). Moreover, nutrients such as nitrogen and phosphorus can be treated, which enables the treated water to be re-used.

Volume control of return sludge or microscopic observation of the microorganism is not necessary. All that is required is control of trans-membrane pressure and basic water quality analysis, both of which you can easily learn. Telemetry can be used to remotely control and check the operational conditions.

KUBOTA Submerged Membrane Unit System is designed for energy conservation. Aeration plays two roles in order to save energy; oxygen supply for biological treatment and cleaning of membrane surface with turbulent flow.

KUBOTA Submerged Membrane Unit is installed in an aeration tank. Since it performs high-concentration activated sludge treatment, no settling tank or sludge thickening tank is required. The size of the aeration tank is also minimized. Consequently, the whole treatment system becomes simple and compact.