The EU’s new Urban Waste Water Treatment Directive (2024/3019) sets strict requirements for micropollutant removal. From 2033 onwards, wastewater treatment plants serving populations above 150,000 must achieve at least 80% removal of specified indicator substances. By 2045, all such plants must comply. Thousands of treatment plants across Europe must now upgrade their systems.
Activated carbon and ozonation are established technologies for meeting these targets, and ozonation is often complemented by activated carbon to remove harmful by-products. Currently, activated carbon is mainly produced from coal and coconut shells. Coal-based products dominate the market but have a large carbon footprint. Coconut shell-derived activated carbon have gained market share as a renewable alternative, but the risks in the supply-chain complicate the sustainability picture. With the directive driving demand for activated carbon in the 2030s, the need for local and climate-friendly solutions is becoming critical.
Bio4All’s Approach: From Biomass to Activated Carbon
The Bio4All project aims to develop value chains from biomass side streams into fuels and chemicals using fast pyrolysis. As part of this work, researchers investigated whether biochar produced as a side stream from fast pyrolysis, typically with high ash content, could be upgraded to activated carbon for wastewater treatment using steam activation.
“The activation process significantly improved the pore structure and surface area of the biochar—properties essential for efficient micropollutant removal. Tests showed that these biobased activated carbons successfully removed pharmaceutical residues from wastewater, demonstrating their potential to meet the EU’s tightening requirements,” say Senior Scientist Virpi Siipola and Research Trainee Väinö Rintala from VTT.
Bio4All research also revealed that the ash concentration of the feed material influences the pore development and can be used to tailor activated carbon properties for different biomass sources. This approach turns a challenge into an opportunity: natural variability in biomass is not a barrier but a design parameter.
Why It Matters
“Utilizing domestic biomass reduces dependence on imported materials, lowers environmental impacts, and creates value from waste. As member states prepare national implementation plans by 2028, locally produced, climate-friendly activated carbon could become a key solution,” Siipola explains.
The Bio4All project is building value chains from biomass residues into fuels, chemicals, and now activated carbon for water purification. Work continues at VTT in follow-up projects, supported by the acquisition of a pilot-scale pyrolysis and activation unit that enables flexible, on-site testing. The coming years will show how far these integrated, biomass-based solutions can advance clean water and sustainable wastewater management.
