Periodic Reporting for period 1 - INCLUE (From waste to resource: Training young researchers on developing innovative, circular solutions for waste sludge)
Reporting period: 2023-10-01 to 2025-09-30
The overarching aim of INCLUE is to provide top-level training to a new generation of high-potential doctoral candidates (DCs) in a crucial field of today’s society: the exploitation of organic waste streams as a resource.
In this training through research program, INCLUE doctoral candidates will focus on sustainable and circular solutions to treat wastewater treatment sludge containing a wide variety of (in)organic pollutants, enabling the application of this untapped resource for renewable chemicals, materials, fuels and fertilisers.
INCLUE hereby responds to the European Green Deal and Farm-to-Fork strategy, in which sludge has been identified as a prime biogenic renewable resource to boost circular economy in terms of renewable energy generation and organic fertilisers production.
INCLUE entails an intersectoral consortium of 6 academic and 11 non-academic partners from 7 countries, who have developed an interdisciplinary training program, encompassing the fields of chemical & environmental engineering, (nano)materials science, chemistry, environmental biotechnology, microbial ecology, life sciences, modelling and
ecotoxicology.
The success of the program is guaranteed via a unique combination of state-of-the-art PhD research, intersectoral secondments, international mobility and interdisciplinary platform-wide courses.
The Research objectives are:
• To develop and optimise sustainable techniques to enhance the properties and composition of sludge through removal of (in)organic pollutants to eliminate any adverse effects for sludge application (i) in a subsequent bioconversion process or (ii) directly as a fertiliser on land.
• To develop augmented fermentative bioconversion processes to produce renewable chemicals and fuels, and to recover nutrients from municipal and industrial sludges, potentially combined with pre-treatment technologies.
• To create tools to assess the overall environmental performance of treated sludges towards toxicity, pollutant soil dynamics and agricultural fertilising value in a combined decision support tool (WP3) for 5 different types of pollutants: pesticides, endocrine disrupting compounds, heavy metals, PFAS and antibiotics. Develop a socio-economic evaluation tool, to support decision-making and societal acceptance.
In this training through research program, INCLUE doctoral candidates will focus on sustainable and circular solutions to treat wastewater treatment sludge containing a wide variety of (in)organic pollutants, enabling the application of this untapped resource for renewable chemicals, materials, fuels and fertilisers.
INCLUE hereby responds to the European Green Deal and Farm-to-Fork strategy, in which sludge has been identified as a prime biogenic renewable resource to boost circular economy in terms of renewable energy generation and organic fertilisers production.
INCLUE entails an intersectoral consortium of 6 academic and 11 non-academic partners from 7 countries, who have developed an interdisciplinary training program, encompassing the fields of chemical & environmental engineering, (nano)materials science, chemistry, environmental biotechnology, microbial ecology, life sciences, modelling and
ecotoxicology.
The success of the program is guaranteed via a unique combination of state-of-the-art PhD research, intersectoral secondments, international mobility and interdisciplinary platform-wide courses.
The Research objectives are:
• To develop and optimise sustainable techniques to enhance the properties and composition of sludge through removal of (in)organic pollutants to eliminate any adverse effects for sludge application (i) in a subsequent bioconversion process or (ii) directly as a fertiliser on land.
• To develop augmented fermentative bioconversion processes to produce renewable chemicals and fuels, and to recover nutrients from municipal and industrial sludges, potentially combined with pre-treatment technologies.
• To create tools to assess the overall environmental performance of treated sludges towards toxicity, pollutant soil dynamics and agricultural fertilising value in a combined decision support tool (WP3) for 5 different types of pollutants: pesticides, endocrine disrupting compounds, heavy metals, PFAS and antibiotics. Develop a socio-economic evaluation tool, to support decision-making and societal acceptance.
WP1:
• First experimental campaigns completed for all pre-treatment technologies: ultrasound, microwave-assisted HTC, electrochemical treatment, and thermal/torrefaction processes.
• Optimal operating conditions for pollutant removal
• Analytical workflows for micropollutant detection in sludge refined, especially methods for PFAS in complex matrices.
• Initial results show promising removal efficiencies for PFAS, pharmaceuticals, heavy metals, pesticides and microplastics.
• Common challenges identified: matrix complexity, analytical limitations, and need to address potential formation of toxic by-products.
• All DCs completed first round of experiments and defined plans for next phase.
Main achievements:
• Validation of feasibility of four non-chemical, energy-driven pre-treatment concepts.
• First proof of concept results for pollutant degradation and removal in realistic sludge matrices.
• Harmonised experimental protocols and analytical workflows across partners.
WP2:
• Anaerobic fermentation studies performed using the pesticide Diuron; adaptation of microbial communities monitored over time.
• Inhibition trials, VFA/methane productivity and stress response analysed; metagenomic characterisation planned next.
• Assessment of biodegradable plastic bags under AD conditions completed at mesophilic and thermophilic temperatures; digestate quality and biogas yield studied.
• First production and characterisation of sludge-derived biochar achieved and batch digestion assays started.
• DCs engaged in courses, conferences, and collaboration activities.
Main achievements:
• Initial demonstration that sludge-associated pollutants (pesticides, plastics) can be addressed without compromising bioconversion performance.
• Insights into microbial behaviour, inhibition, and adaptation dynamics under realistic sludge conditions.
• First step towards engineered microbial consortia and optimised reactor operations.
WP3:
• Foundational work started for ecotoxicity, environmental impact assessment and modelling of treatment scenarios.
• First results for biosensor concept using Indicator Displacement Assays for multipollutant detection and toxicity screening.
• Limitations in real sludge matrices identified and strategies for improving selectivity defined.
• Embryotoxicity, endocrine disruption and toxicity assays applied across a full-scale WWTP; persistence of endocrine-active compounds observed in sludge streams.
• Database creation and sample characterisation underway for sludge and sludge-derived products (physicochemical properties, pollutants, toxicity, nutrient value).
• LCA models for AD and THP developed and compared; environmental hotspots and advantages mapped.
• First version of multi-criteria decision-making framework drafted.
Main achievements:
• Strong methodological foundation for a combined environmental-techno-economic decision support tool.
• Multi-layer data integration platform established: analytical, toxicological, agricultural and socio-economic dimensions.
• First experimental campaigns completed for all pre-treatment technologies: ultrasound, microwave-assisted HTC, electrochemical treatment, and thermal/torrefaction processes.
• Optimal operating conditions for pollutant removal
• Analytical workflows for micropollutant detection in sludge refined, especially methods for PFAS in complex matrices.
• Initial results show promising removal efficiencies for PFAS, pharmaceuticals, heavy metals, pesticides and microplastics.
• Common challenges identified: matrix complexity, analytical limitations, and need to address potential formation of toxic by-products.
• All DCs completed first round of experiments and defined plans for next phase.
Main achievements:
• Validation of feasibility of four non-chemical, energy-driven pre-treatment concepts.
• First proof of concept results for pollutant degradation and removal in realistic sludge matrices.
• Harmonised experimental protocols and analytical workflows across partners.
WP2:
• Anaerobic fermentation studies performed using the pesticide Diuron; adaptation of microbial communities monitored over time.
• Inhibition trials, VFA/methane productivity and stress response analysed; metagenomic characterisation planned next.
• Assessment of biodegradable plastic bags under AD conditions completed at mesophilic and thermophilic temperatures; digestate quality and biogas yield studied.
• First production and characterisation of sludge-derived biochar achieved and batch digestion assays started.
• DCs engaged in courses, conferences, and collaboration activities.
Main achievements:
• Initial demonstration that sludge-associated pollutants (pesticides, plastics) can be addressed without compromising bioconversion performance.
• Insights into microbial behaviour, inhibition, and adaptation dynamics under realistic sludge conditions.
• First step towards engineered microbial consortia and optimised reactor operations.
WP3:
• Foundational work started for ecotoxicity, environmental impact assessment and modelling of treatment scenarios.
• First results for biosensor concept using Indicator Displacement Assays for multipollutant detection and toxicity screening.
• Limitations in real sludge matrices identified and strategies for improving selectivity defined.
• Embryotoxicity, endocrine disruption and toxicity assays applied across a full-scale WWTP; persistence of endocrine-active compounds observed in sludge streams.
• Database creation and sample characterisation underway for sludge and sludge-derived products (physicochemical properties, pollutants, toxicity, nutrient value).
• LCA models for AD and THP developed and compared; environmental hotspots and advantages mapped.
• First version of multi-criteria decision-making framework drafted.
Main achievements:
• Strong methodological foundation for a combined environmental-techno-economic decision support tool.
• Multi-layer data integration platform established: analytical, toxicological, agricultural and socio-economic dimensions.
Across the three scientific work packages, the project already demonstrates several advances towards exceeding current scientific and technological practice:.
In Work Package 1:
• Application of multiple non-chemical, energy-driven pre-treatment techniques (ultrasound, MW-HTC, thermal, electrochemical) specifically tailored for multi-pollutant removal in sludge is still largely unexplored at this level of integration.
• Development of improved analytical methods for PFAS, heavy metals and microplastics in complex sludge matrices contributes to enhanced detection capability where standard methods are insufficient.
• Initial indication that treatment conditions can be tuned to affect pollutant fate and transformation rather than merely extract or dilute them.
In Work Package 2:
• Novel coupling of sludge pre-treatments with targeted bioconversion strategies for simultaneous pollutant removal and resource recovery.
• Generation of new knowledge on microbial adaptation and community responses to pesticides and biodegradable plastics under anaerobic conditions — areas where available research is still fragmented.
• Systematic assessment of bioplastics degradation in AD and impact on digestate quality is a relevant advancement for real-world deployment of organic waste systems.
In Work Package 3:
• Introduction of biosensor-based toxicity indicators for sludge matrices (IDAs) and integration with endocrine-disruption assays creates a new framework for ecotoxicity and regulatory compliance monitoring.
• Implementation of a multi-database and multi-method evaluation (embryotoxicity, biosensing, phytotoxicity, LCA, LCC, MCDM) surpasses conventional single-indicator sludge evaluation approaches.
• Development of an integrated decision-support methodology that explicitly combines technical, environmental, economic and policy criteria is a clear step beyond current decision-making practice for sludge valorisation.
In Work Package 1:
• Application of multiple non-chemical, energy-driven pre-treatment techniques (ultrasound, MW-HTC, thermal, electrochemical) specifically tailored for multi-pollutant removal in sludge is still largely unexplored at this level of integration.
• Development of improved analytical methods for PFAS, heavy metals and microplastics in complex sludge matrices contributes to enhanced detection capability where standard methods are insufficient.
• Initial indication that treatment conditions can be tuned to affect pollutant fate and transformation rather than merely extract or dilute them.
In Work Package 2:
• Novel coupling of sludge pre-treatments with targeted bioconversion strategies for simultaneous pollutant removal and resource recovery.
• Generation of new knowledge on microbial adaptation and community responses to pesticides and biodegradable plastics under anaerobic conditions — areas where available research is still fragmented.
• Systematic assessment of bioplastics degradation in AD and impact on digestate quality is a relevant advancement for real-world deployment of organic waste systems.
In Work Package 3:
• Introduction of biosensor-based toxicity indicators for sludge matrices (IDAs) and integration with endocrine-disruption assays creates a new framework for ecotoxicity and regulatory compliance monitoring.
• Implementation of a multi-database and multi-method evaluation (embryotoxicity, biosensing, phytotoxicity, LCA, LCC, MCDM) surpasses conventional single-indicator sludge evaluation approaches.
• Development of an integrated decision-support methodology that explicitly combines technical, environmental, economic and policy criteria is a clear step beyond current decision-making practice for sludge valorisation.