WP2 will be on the development of superior biochemical conversion of (pre-treated) sludge into renewable chemicals (i.e., volatile fatty acids – VFA), nutrients (N, P) and fuels (i.e., NH3, CH4). Whereas the processes in this WP will in first instance be developed to tackle sludge streams, further bioconversion of the treated sludge coming from DCs 3 and 4 will also be researched.
A first research project will investigate the stress-induced anaerobic fermentation under naturally-induced internal stressors such as extreme pH-conditions to anaerobically degrade different sludges contaminated with pesticides, PFAS, and endocrine disruptors, while simultaneously producing high loads of VFA. The addition of hydrochar (produced by DC2) and engineered biochar (produced by DC7) will be explored for its potential to enhance the interspecies electron transfer and microbial colonisation rate and to alter operating conditions (e.g., pH), hereby increasing pollutant degradation during bioconversion (DC5).
Besides the above-mentioned pollutants, the problem of poor bioplastics (BP) degradation during anaerobic processes will be addressed in this WP. DC6 will investigate the performance of a novel anaerobic digester system towards the efficient biodegradation of bioplastics in sludge, and investigate the microbial mechanisms involved in the removal of such complex pollutants, and finally develop strategies to minimize the risk of BP spreading upon land application of sludge digestate. DC7 will finally design novel engineered biochar-based materials (EBM) that function as a catalyst to simultaneously (i) improve the methane yield during anaerobic digestion of sludge (i.e., tannery sludge with extreme levels of chromium and pulp & paper sludge containing high levels of AOX) and (ii) to efficiently capture and recover nitrogen (N) and phosphorous (P) from the sludge onto the EBMs for further use in agriculture as nutrient-enriched soil amender.