Sludge dewatering in sludge drying reed beds (SDRBs)

Abstract

Sludge dewatering in reed beds has been recently used in France. For activated sludge in extended aeration the design of such reed beds is based on a surface loading of 50 kg DM m-2 y-1, in France and Denmark as well when the growth of the reeds is well established. In Denmark, this type of dewatering process is used for much more larger cities than the ones in France. In each plant recently built in Denmark, the design is different and the number of beds is greater, at least eight. This distinctive feature seems to be of major interest to increase the dry matter content of the dewatered sludge and also to make easier the scheduled withdrawals of the beds separately.