Since the population, average age and life standards are rising all over the world, we produce and use more and more complex compounds that eventually end up in our water systems. The risks for our environment and health are hard to determine because of a long list of compounds and low prevalent concentrations. Still, the scale of the problem and the potential effects show that we should do something to reduce the discharge of organic micropollutants (OMPs) into the environment. Cooperating with the consultancy company Royal Haskoning DHV, our study aims to contribute by further developing a hybrid tertiary treatment technology that can remove OMPs from wastewater treatment plant (WWTP) effluent.
This hybrid technology (Figure 2) combines the efficiency of biological removal and the effectivity of ozonation to remove a broad range of OMPs, with limited energy demand. WWTP effluent is fed into the first reactor (bio), where dissolved organic carbon (DOC) is removed to reduce the required ozone dose in the second reactor (ozone). In the third reactor (bio), potentially toxic ozone transformation products are further mineralized by microorganisms.
We want to increase our understanding of the processes inside the reactors to finally improve and upscale this hybrid technology by studying:
- Interactions between different types of DOC and ozone and how this affects ozonation of OMPs
- Formation and further break down of transformation products using both chemical and toxicological analyses
- The stability of the technology: e.g. over time and for different types of effluents
- Optimizing the reactor configuration; create a design that can be implemented and operated easily as a tertiary treatment step behind conventional WWTPs
- Upscaling the technology; working towards a pilot scale plant