Filtration of biologically treated wastewater serves for removal of suspended solids (suspensa) remaining in clarifier effluents. Such suspensa contain about 50 % carbon, almost 10 % nitrogen and over 1 % phosphorus.

Around 1 mg/L (ppm) of phosphorus remain in the effluent, even if the biological treatment stage is designed for enhanced biological phosphorus removal and/or chemical phosphorus precipitation. Subsequent filtration is necessary where stringent phosphorus limits must be reliably maintained.

• Our RoDisc® Rotary Mesh Screen is provided with fabric of a mesh size between 0.01 and 0.1 mm. The fabric is applied on both sides of slowly rotating discs.
• Wastewater flows continuously upstream through our Sand Filter, and its sand bed is continuously backwashed.
• Membrane Bio-Reactors perform biological treatment and filtration. Our Membrane Filters retain not only all solids but also all bacteria within the bio-reactor.