Sewage contains valuable substances that can be used circularly as a raw material for biobased products. However, this potential is currently underused. In the European Interreg project WOW! we wanted to change this by demonstrating that it is technically feasible to extract raw materials from sewage, by showing that there is a market these materials and by addressing legal barriers for the market uptake.
The potential of raw materials from sewage
We have shown that the recovery of carbon-based elements from sewage results in valuable products such as biodiesel, biochar and PHA. These products can replace items that are currently made from natural resources (i.e. oil, coal). The use of raw materials from sewage therefore contribute to a circular economy in the EU and cost prices proof that extracting them at the right place in the right way is profitable.
Extracting raw materials from sewage successfully done!
Three pilots were preformed at different sewage treatment plants (STP’s):
PHA bioplastics pilot at Buchenhofen STP (GER)
Cellulose pilot at STP Ede (NL)
Lipids pilot at STP Audun le Tiche (Fr)
All pilots were successfully implemented.
Decision support for operators and market organisations
To help sewage treatment plant operators with the circular possibilities at their STP we have developed a Decision Support Tool. Market potential studies have been developed to get insight in market requirements for raw materials from sewage and to get insight in cost prices and market prices.
What holds us back?
Currently the re-use of sewage and sludge arising from wastewater treatment is only very limited and a free option to choose. There are barriers that hold back the transition towards a circular water economy. In “calls for action” on national level we have the proof that EU end of waste frameworks are interpreted differently in the member states, resulting in different national rules. In our European policy roadmap we address the need for a clear EU legal framework to reach policy harmonization and a mind shift towards thinking in values instead of waste.