DAF unit for municipal wastewater treatment plant
The city of Ajaccio at Corsica is operating with large fluctuations in the influent of their municipal wastewater treatment plant. During the holiday season the quantity of wastewater to the municipality is significantly higher than in the rest of the year. The design of the new biological treatment system at this municipality has to operate with these variable flows during all seasons in a year. A biological treatment system based on MBBR technology is selected. MBBR stands for Moving Bed Bio(film) Reactor
- Small footprint.
- Adaptable to changing loads.
- Stable for flow variations
The effluent quality after a typical well designed MBBR is in accordance with the European Regulations, except for the amount of suspended solids.
In cooperation with the main contractor for the project, Vinci Environment from Paris, Nijhuis Water Technology designed two dissolved air flotation systems to remove the suspended solids from the MBBR effluent. The polished effluent quality is within the required discharge levels.
Nijhuis Water Technology supplied two units type NPF 600 HX. These high rate flotation units are equipped with a special designed discharge valve and can handle the large flow variations of 50 to 815 m3/hr for each unit. The two dissolved air flotation units are reducing the total suspended solids amount from 100 – 350 mg/l down to less than 20 mg/l.