Dewatering is one of the most important processes in the entire water treatment procedure. As the burning of sewage sludge, or its disposal at a landfill site, both involve costs, sludge dewatering pays off, particularly when several tons accrue each day.

After the sludge has been stabilised and thickened, as far possible, it still retains a fluid consistency. The mechanical sludge dewatering process then enables the separation / removal of a portion of the sludge water and thus reduces the total volume. Flocculating agents are added, which effect a separation of the water from the sludge as a result of different electric charges. Sewage sludge can be used in agriculture, in so far as it complies with statutory sewage sludge regulations. The disposal methods are either burning or landfill sites, depending on the local framework conditions.

Bilfinger Water Technologies, with its PASSAVANT® and JOHNSON SCREENS® brands, provides economic sludge dewatering processes which achieve optimal results with low polymer consumption. The technical procedure involves the separation of water in a continuous process with a combination of separation by gravity and by pressure. Mechanical dewatering is always recommended when there is a demand for economically viable volume and weight reduction, with a maximum possible solids concentration, combined with an optimal yield of clarified water. Our machines are universally adaptable and are, therefore, amongst the most utilized sludge dewatering machines worldwide.