Technical Details

Technical details

Thanks to its tried and tested design, Biosep™ offers a highly compact water treatment solution, enabling the treatment to be carried out with high concentrations of biomass (8 to 12 g SS/l). Biosep™ is a solution suitable for compact installations.

Operating principle

Biosep™ uses a biological tank and a membrane system which can be presented in different configurations depending on the application and local conditions. In the immersed version (the most common), these modules are directly immersed in the biological tank or in a separate tank.

  • After pre-treatment (e.g. screening sand removal), raw water flows into the biological tank where carbon, nitrogen and phosphorus pollutants are removed.
  • Membrane filtration then separates the water from the activated sludge: the treated water is drawn off using a low-pressure (< 0.6 bar) pump. The sludge retained by the membrane creates a sludge cake on the outside membrane surface. The excess sludge is directly removed from the biological tank for dewatering.
  • Sustainable membrane filtration performance is key to the process; this is based on different automated functions which provide for membrane washing and backwashing: backwash, air injection and chemical cleaning (usually bleach and citric acid). This is Veolia knowledge and expertise.

An optimized and simplified treatment line

By replacing the conventional gravitational clarification stage, membrane separation goes away with the limitations surrounding sludge settling: discharge quality is completely controlled.

Compact treatment line

Conventional activated sludge versus Biosep™

A physical barrier at the core of the system

The choice of the filtration membranes (organic flat sheet or hollow fiber membranes) is an important factor.

The main selection criteria are:

  • Sustainable mechanical characteristics (integrity maintained over time)
  • Sustainable hydraulic performances
  • Hydraulic flow recovery after a peak
  • Related operational costs controlled

Veolia has no partnership established with a particular membrane supplier, which allows us to choose and provide the most suitable membrane, depending on technological evolution and feedback from operational sites. Veolia has more than 120 references, both municipal and industrial, with more than a dozen membrane suppliers.