- Client: EYDAP
- Solution: CambiTHP - B6
The wastewater treatment plant of Psyttalia, is the final recipient of domestic sewage and pre-treated industrial wastewater of the greater Athens area in Greece, receiving an average wastewater flow of 730.000 m³/d, with a biological treatment capacity of 3,500,000 Equivalent Population.
In order to improve the energy footprint of the WWTP, the application of Thermal Hydrolysis Process (THP) was preferred to the option of constructing additional anaerobic digestion tanks. Since August 2015 approximately half of the generated Waste Activated Sludge has been treated by a Cambi Thermal Hydrolysis B6-4 system, while the thickened Primary Sludge stream is by-passing THP and is mixed with the hydrolysed WAS stream before entering the 4 digesters. The 4 other conventional digesters have treated the remaining sludge
After more than a year since the introduction of WAS in the installed THP Unit, the dewaterability of the mixed digested sludge has significantly been improved, in addition, biogas generation and digester efficiency in terms of solids destruction has been increased.
The following key performance indicators, as measured and calculated during the period of operation (May 2016 – March 2017) summarize the benefits of the WAS-Only configuration:
- Improved dewaterability from 22% dry solids to 31%
- Increased Volatile Solids reduction from 45% to over 52%
Increased biogas production from approximately 390 Nm3 / kg TS fed to 450 Nm³ / kg TS fed, 15,4% increase (by treating approximately only 20% of the generated sludge amounts)
This is providing substantial reduction of energy use and cost savings at the sludge drying plant of Psyttalia.