Which pumping systems are suitable for thickened sludge of 8% TS?

100 m³ of secondary sludge (8 kg/m³) are thickened in a gravity thickener to 32 kg/m³. How much is the percentage of TS? How much sludge volume is left?

Compute the required surface area and the depth of a round, static thickener:
- primary sludge: 200 m³, 2.5% TS withdrawn twice a day for one hour
- secondary sludge: 500 m³, 0.6% TS withdrawn continuously