We provide Dissolved Air Flotation Thickener (DAFT) for sludge thickening specially prior to digestor tank. This unit separates sludge by floating it through the Dissolved Air Flotation process and the inert grits settle down at the bottom which are removed separately. The process has the advantage that it separates inert grit from the organic solids before entering the Digestors. The inert grit accumulates inside the Digestor and reduces the available volume over time and need to be cleaned from the tank time to time. This can be avoided by deploying DAFT prior to the Digestor tank. The salient features of this unit is similar to DAF Separator which has been described in the separate section.