If the wastewater stream of a wastewater treatment plant is treated both conventionally and with a membrane filtration, the combination is called a Hybrid System. The system can consist of either two parallel systems with individual biological treatment steps, or of a common aeration step with split biomass separation, which is effected by conventional treatment and membrane filtration.

Hybrid Systems are particularly suited for upgrades or capacity increases of existing conventional plants. The only investment necessary (compared to a completely new plant) are the costs for treatment of the additional hydraulic or organic load.

Further advantages are the low footprint requirements and the production of high-quality process water for many re-use applications.