Nova tecnologia híbrida que combina micro/nano-arejamento e anaerobiose para intensificar a produção de biometano a partir de águas residuais ricas em lípidos

There are thousands of biogas and biomethane plants across Europe and significant challenges concerning the AD of lipid-rich wastewater still exist. It is necessary to overcome the limitations of lipid rich wastewater treatment and valorization to biomethane. This demands research and development to attain urgent European goals related to the EU Green Deal and REPowerEU. In HyTech4Methane, a novel hybrid approach will be conceived, combining micro/nano-aeration and anaerobiosis to boost biomethane production from lipid-rich wastewaters (Fig.1). This represents a completely novel concept, based on previous results obtained by the team, combining multidisciplinary fundamental and applied research aligned to the needs of wastewater treatment companies. HyTech4Methane will answer the following research questions: RQ1: What are the best O2 range and operating conditions to accelerate conversion of LCFA? RQ2: Is biofilm formation required to potentiate the process? Which is the biofilm composition? RQ3: What is the best material and operating conditions for the PFR, to accelerate and maximize overall LCFA conversion in biofilm and further biofilm detachment ? RQ4: Does this novel hybrid process (micro/nano-aerated + anaerobic steps) accelerate and maximize overall lipids conversion to methane? RQ5: Is this process economically viable? Three experimental tasks are defined to address the specific RQ. This structure is represented in the supplementary file “Work Plan_Scheme”. In Task 1, RQ1 and RQ2 will be answered. For that, we will evaluate the effect of several defined micro/nano-concentrations of O2 in the activity and gene expression of FAB, to establish a direct link between O2 and FAB dynamics. OL to PAL conversion, associated to biofilm formation, will be promoted by fine-tuning O2 levels, and the best aeration conditions for intensifying this conversion will be defined. The biofilm will be deeply characterized. In Task 2, the micro/nano-aerobic treatment step will be further optimized in continuous biofilm PFR, by testing different materials and reactor operating conditions, with the goal of maximizing overall OL to PAL conversion in biofilm, and its further detachment for the subsequent anaerobic treatment step. RQ3 will be answered. In Task 3, as a proof of concept, biomethane production from a real dairy wastewater will be studied. Pilot-scale PFR will be scaled-up, integrating the information from the previous tasks. The IASB, a pilot-scale bioreactor, available at CEB (UMinho), will be adapted to incorporate the PFR in its interior. This will result in the conceptualization of the hybrid technology composed by a compact, modular bioreactor, integrating 2 steps, presenting several advantages related with less space need, less costs of operation and implementation, and more profits allied to more energy production. This task will be done in collaboration with the biotech company Colsen and the end-user Lacticínios do Paiva engaged in this project, that will provide the wastewater samples. Letters of support are attached. In the end RQ4 will be answered. A demonstration site will be created, exploiting the pilot scale trials, to showcase good practices and inspire practitioners, raise awareness, and promote citizens’ engagement. In the end of Task 3, a techno-economic assessment will be performed to answer RQ5. These results will greatly impact the operation and control of full-scale reactors.