Flotation Units, type GWL

The GWL flotation units are robustly built and characterised by large "free surface" areas. For wastewater containing large solids contents, the design provides sufficient retention time for separation and pre-dewatering of the skimming.

The GWL units have been designed for wastewater with COD contents of 10 000 mg/l and higher. In the same system, suspended solids, fat, oil, grease and other dispersed and/or flocculated materials are removed. Also small amounts of settled materials can be removed.

Typical GWL features are the very efficient micro aeration system and a stainless steel sediment transport auger operating over part of the base of the flotation system.

The complete design of the GWL systems is based on elimination of hydraulic disturbances, resulting in a complete stable and laminar flow at all cross sections of the system. Depending on the application, specially with respect to the solids amount to be removed, either a special multistage gas/liquid pump or a pressure vessel type saturation unit is applied to generate a supersaturated water/air (gas) mixture.