The very diluted sludge (solid concentration 0,5 – 1,5% DS) is concentrated to obtain a solids content variable from 6 to 8% DS. This operation reduces the sludge volume from 5 to 15 times. The consistency of the thickened sludge is still fluid or semi-fluid and usually requires further treatment. Giotto Water offers the rotating drum thickener – Rototik and the belt thickener – Gravity Table.
Mechanical rotating sludge thickener, capable to thicken the sludge up to a concentration of 10%. The construction is entirely in stainless steel. The sludge is delivered to the external mixer to be conditioned with chemicals and then discharged inside the thickening drum. The drum consists of 4 zones separated by anular rings, each of which has an adjustable opening to adapt the sludge retention time according with its characteristics.
Continuous sludge belt thickener, where the water drains through a moving polyester filtering belt, separating the solids contained in the sludge from the filtrate. The use of special plows improves the drainage by alternately compressing, reversing and distributing the sludge on the belt. Even the most unstable sludge can be easily treated with this unit. The Gravity Table separates fast over 95% of the suspended solids from the sewage sludge, with a minimum consumption of polyelectrolyte.