Sludge drying reed beds (SDRBs) are a combination of traditional sludge drying beds and constructed wetlands.
Theirmain advantages include low investment, infrequent biosolids removal (of the order of years), dewatering
and mineralization of biosolids, minimization of biosolid volume, simplicity and economy, and production of a
beneficial, well-composted side product. A constructed wetland facility is used to treat the sewage from the
municipality ofNeaMadytos, Thessaloniki Province,NorthGreece. The primarily produced biosolids in the Imhoff
tank of this facility are treated with a vertical flow SDRB. The performance and dewatering efficiency of this
systemwasmonitored for 1year.Over the 12 years of operation of the treatment plant, 7884m3 of biosolids from
the Imhoff tank were transferred to the SDRBs. Until today, no biosolids were removed, and the level of the
dewatered sludge on the bed is built to about 20 cm, with a volume of residue sludge of 28m3. Thiscorresponds to
a biosolid reduction of 99.64%. At the end of the examination period the TS (VS) content varied from55% (40%) in
the top layer to 65% (35%) in the bottom layer. The heavy metal concentration meets the European Union
standards for heavy metals in case of agricultural disposal of the treated sludge.