RT Journal Article T1 An optimised control system to steer the transition from anaerobic mono- to co-digestion in full-scale plants A1 Taboada Santos, Antón A1 Carballa Arcos, Marta A1 Morales Pereira, Nicolás A1 Vázquez Padín, José Ramón A1 Lema Rodicio, Juan Manuel A1 Gutiérrez Costa, Ramiro AB Traditional wastewater treatment plants (WWTPs) are electrical consumers, with a usual high demand in the range of 0.3 to 0.6 kWh/m3 of wastewater treated. Their digesters are commonly oversized, and consequently operated at low organic loading rates (OLRs). This opens a great opportunity for anaerobic co-digestion (AcoD) as an interesting technology to increase methane productivity and the electrical self-production in WWTPs. However, there is a quite limited implementation of AcoD at full-scale plants, since the transition from mono- to co-digestion and the further AcoD optimisation is a crucial and delicate step that could lead to the inhibition of the process if not thoroughly controlled. In this study, a methodology based on an optimum control strategy is explained in detail and it was applied to safely and optimally steer the transition from mono- to co-digestion and to maximize methane production during AcoD. A lab-scale anaerobic digester of 14 L mimicking the full-scale one (3,500 m3) was operated 30 days in advance to anticipate and if needed correct any operational destabilization that might occurr. As a result, the treatment of sewage sludge with two co-substrates (coming from a pig slaughterhouse and from a frying industry), which accounted for just 11% of the feeding flowrate, at a hydraulic retention time of 20 days allowed to raise the OLR and the methane production by 2-fold and 3-fold, respectively, increasing the self-produced electricity from 25% to 75% of the total demand of the WWTP. The diagnosis indicators proved to be accurate to take decisions concerning wastes blending and the strategy of increasing OLR. Besides, the proposed control system provides the steps to ensure a safe transition from anaerobic mono- to co-digestion and further optimisation at full-scale plants PB Royal Society of Chemistry SN 2053-1400 YR 2019 FD 2019-05-01 LK http://hdl.handle.net/10347/18756 UL http://hdl.handle.net/10347/18756 LA eng NO Taboada-Santos, A., Carballa, M., Morales, N., Vázquez-Padín, J., Gutierrez, R., & Lema, J. (2019). An optimised control system to steer the transition from anaerobic mono- to co-digestion in full-scale plants. Environ. Sci.: Water Res. Technol., 5, 1004-1011. doi: 10.1039/c9ew00033j NO Despite the rapid increase of anaerobic co-digestion works over the last years, the very small number of pilot- and full-scale studies available in the literature is a major barrier to its full-scale implementation. In this paper, a control strategy methodology was applied in a full-scale sludge digester to safely steer the transition from anaerobic mono- to co-digestion and to maximize methane production. NO This work was supported by SmartGreenGas project (Spanish Government, AEI, 2014-CE224). The authors from Universidade de Santiago de Compostela belong to the Galician Competitive Research Group ED431C 2017/029 and to the CRETUS Strategic Partnership (AGRUP2017/01). All these programs are co-funded by FEDER (EU) DS Minerva RD 29 abr 2026