The wastewater treatment plant equipped with ultrafiltration membrane module are an excellent alternative to the conventional activated sludge processes, MBR modules fulfilling a dual function: secondary settler and disinfection. The membrane modules are easy to integrate into the wastewater plant technological flow and can be mounted into the biological reactor or into a secondary filtrantion tank.
Unlike the classical solution with gravitational separation, with a reduced efficiency (due to the inefficient gravitational separation or due to sludge flotation in the secondary settler), the physical separation through ultrafiltration membranes is a more complete process, resulting a treated water free of suspension matter. During the biological and ultrafiltration process, the activated sludge concentration increases. In order to ensure a constant concentration the discharge of excess sludge resulted from MBR module is required. The sludge concentration is determined through solid matter sampler and at the time this exceeds 10-12 g/l, the drain pumping system starts feeding the sludge storage tank and after then the dehydrating unit, where the sludge humidity is reduced.
The resulted effluent is discharged into the permeat tank and then a part of the treated water goes to the membranes backwash and the other is drained into the emissary. The membrane cleaning process is automatic and takes place through the pneumatic electrovalves.
