Domestic sludge is dispersed onto reed beds. The reed plants grow through the overlying sludge and develop numerous roots in the substrate. This leads to a forced dewatering and mineralization of the sludge. The dewatering is driven by evapotranspiration and particularly by a drainage system on the bottom of the sealed reed beds (polyethylene liner).
The sludge volume declines to about 10 % of the initial volume. Usually the reed beds work for a period of 8 to 12 years without sludge removal. The resulting product of the dewatering is an earthy organic material. The sludge humus can be used for further composting, for fertilization, for thermal recycling, for recultivation, gardening and landscaping.
Sludge dewatering and mineralisation is achieved by applying sludge to the surface of specially designed vertical flow systems. The reeds absorb particularly high rates of water which they transpire into the air through their leaves. This process, in combination with an enhanced drainage function and the aerating action of the plants, results in an efficient low cost dewatering of the applied sludges.
Further technology explanation:
Download 1: Natural treatment of sewage sludge in reed planted dewatering and mineralization beds
An example for faecal sludge management (FSM) in India is given here.
Some of our realized projects you can find here.
Two more examples of reed based sludge treatment plants can be seen here:
Treatment plant Bechhofen
Treatment plant Fronhausen
For purchase of adapted reed plants (aquatic macrophytes) look at: