Treatment process combination
The recently constructed wastewater treatment plant on the island of Thirasia comprises a number of innovative unconventional treatment methods. Mechanically pre-treated wastewater will undergo solar heterogeneous photo-catalysis with TiO2 as catalyst followed by a constructed wetlands (CWs).
Wastewater treatment is followed by ultrafiltration membranes for the tertiary treatment and the further quality upgrade of effluents. The final effluent is then disinfected and will be reused for irrigation in the proximity of the treatment unit, while subsurface disposal of the surplus of the treated effluent will also take place contributing to aquifer recharge.
Aims and ambition
The combination of natural and engineering treatment systems in the WWTP of Thirasia is expected to achieve high pollutant removal efficiency and compliance with the Greek water reuse legislation. In particular, the demonstration of solar photocatalysis and ultrafiltration as pre- and post-treatment for CWs at full scale helps
- to evaluate the overall reliability of the system
- to validate the positive impact of solar photo-catalysis as pre-treatment for CWs (recycling of photo-catalyst, improved biodegradation, reduced land requirements)
- to assess the operational stability of ultrafiltration process and the suitability of constructed wetlands as pre-treatment
- to increase the system marketability in similar conditions