Solids removal by flotation
Flotation is an effective method for the removal of suspended solids (SS), fats, oils and greases (FOG) from liquid effluents, thereby reducing the associated Chemical Oxygen Demand (COD).
Flotation can also be used following anaerobic digestion in order to separate and remove the residual suspended matter, prior to additional biological treatment or discharge to sewer.
The Cavitation Air Flotation (CAF) unit offered by Clearfleau has a number of advantages over other types of flotation: lower capital costs, ease of start-up/shutdown and reduced operating costs. Clearfleau's CAF units are provided by Hydro International and are manufactured in Ireland based on a design developed in the US. For further information visit http://www.hydrointernational.com/
The self-contained, skid mounted CAF, fitted with feed pump, dosing pumps, sludge removal pump and control panel, also includes a flash mixing tank for coagulant addition. In the CAF, conditioned effluent is aerated and suspended and flocculated solids are floated and then removed.
Typically the CAF, will reduce COD by up to 60% and SS by 80-90%, depending on the application. Units are constructed from stainless or coated mild steel (with capacity from 2 m3/h to 200 m3/h). Lower cost, glass reinforced plastic (GRP) units are offered for flow rates up to 10 m3/h.
The CAF can be used in a range of treatment situations:
- For primary handling of effluent prior to treatment for sewer or watercourse discharge
- For a secondary stage, after anaerobic treatment to further remove solids
- For water recycling, pre-treatment of effluent prior to a Membrane Bio Reactor (MBR)
- As part of a sludge thickening and dewatering process
CAF units have applications in many different sectors including food, brewing and dairy. Reference installations are available. We can offer a 2-4 m3/h pilot unit for trials on your site.
For more information and to arrange a site visit, please call 0844 477 6292 or email info@clearfleau.com
