The flotation is a physicochemical method of treating highly polluted wastewater. It is mainly used for treatment of industrial wastewater or for the initial stage of treatment of municipal wastewater. The process is most effective for the separation of the suspended solids in the water. Before the flotator, the water goes through a flocculater, where is is efficiently mixed with chemical agents, serving to speed up the process of flocculation and coagulation.
Flotation is a process of adhesion of the solid phase of the suspension to the gas bubbles and its floating to the surface together with the bubbles.
It was found that the smaller solid particles adhere with a higher probability to a small gas bubbles, therefore, to extract fine-dispersed particles small gas bubbles are needed. To make these bubbles, compressed air is entering special pump, where it mixes with a conditionally clean water, after that, this water (saturated with dissolved air with bubbles size of 20 to 60 microns) is mixed with the wastewater. Feeded by a pump, at the inlet of the flotator. On their way to the surface, the bubbles drag the suspended solids out of the water thus forming a layer of thickened sludge which removed by a scraper.
Generally the system consists of:
- Feeding pump
- Flocculation pipe
- Automatic station for preparation and dosing of polyelectrolyte
- Tanks for the reagents
- Dosing pumps for reagents
- Pump for the thickened sludge
- Electrical board for processes management
AQUARIUS ND Ltd. offers flotation systems with a capacity from 2 to 160 m3 per hour together with all necessary equipment.
For process optimization, the system is equipped with PLC and a display type “touch screen” from SIEMENS.