Decentralized sludge treatment with efficient energy management and elimination of micro pollutants in sewage sludge – experience and lessons learned from the wastewater treatment plant in Linz Unkel Germany: PRESENTATION ONLY
Cadavid, G., Wigand, F., O´Brien, L., Knörle, U., Eliquo Water Group
(free)
On January 1, 2018, the German cabinet approved the new sewage sludge ordinance, which makes
phosphorus (P) recovery from sewage sludge obligatory for all German wastewater treatment plants
(WWTP) larger than 50,000 person equivalents (p.e.). The regulation will require these plants to
recover the phosphorus by 2029 if the sludge contains more than 2% phosphorus /DS (dry solids)
and prohibits land application of sewage sludge. The new legislation is driving up the sludge disposal
cost to more than 100€/ton in many regions. As a result, WWTPs in Germany are exploring
decentralized sludge management solutions. ELIQUO has implemented such solutions, which
include a proprietary low-temperature belt Dryer: EloDry®, together with a Carbonization technology
PYREG® at several WWTPs. These installations are characterised by small footprint, flexibility,
modular design and efficient energy management. At Linz-Unkel WWTP, the sludge undergoes
drying and then staged combustion using the carbonization technology at around 6,500C, which
reduces the sludge to a fraction of its original volume while disinfecting it and removing micro
pollutants, such as pharmaceutical residues. Moreover, the residual ash has a high percentage of
plant-available phosphorus. This paper details the data and findings from the full-scale
implementation at Linz Unkel, as well as some lessons learned from the regulatory landscape in
Germany that can be applicable to the sludge management practices in the UK.
