Assessment of single- vs. two-stage process for the anaerobic digestion of liquid cow manure and cheese wheyAssessment of single- vs. two-stage process for the anaerobic digestion of liquid cow manure and cheese whey Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2022-10-052021enThis research has been co-financed by the European Union (European Social Fund—ESF) and Greek national funds through the Operational Program “Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF)—Research Funding Program: Heracleitus II. Investing in knowledge society through the European Social Fund.The growing interest in processes that involve biomass conversion to renewable energy, such as anaerobic digestion, has stimulated research in this field in order to assess the optimum conditions for biogas production from abundant feedstocks, like agro-industrial wastes. Anaerobic digestion is an attractive process for the decomposition of organic wastes via a complex microbial consortium and subsequent conversion of metabolic intermediates to hydrogen and methane. The present study focused on the exploitation of liquid cow manure (LCM) and cheese whey (CW) as noneasily and easily biodegradable sources, respectively, using continuous stirred-tank reactors for biogas production, and a comparison was presented between single- and two-stage anaerobic digestion systems. No significant differences were found concerning LCM treatment, in a two-stage system compared to a single one, concluding that LCM can be treated by implementing a single-stage process, as a recalcitrant substrate, with the greatest methane production rate of 0.67 L CH4/(LR·d) at an HRT of 16 d. On the other hand, using the easily biodegradable CW as a monosubstrate, the two-stage process was considered a better treatment system compared to a single one. During the single-stage process, operational problems were observed due to the limited buffering capacity of CW. However, the two-stage anaerobic digestion of CW produced a stable methane production rate of 0.68 L CH4/(LR·d) or 13.7 L CH4/Lfeed, while the total COD was removed by 76%. http://creativecommons.org/licenses/by/4.0/Energies1417Dareioti _et_al_Energies_ 14(17)_2021.pdfChania [Greece]Library of TUC2022-10-05application/pdf1.2 MBfree Dareioti Margarita A. Vavouraki Aikaterini Βαβουρακη Αικατερινη Tsigkou Konstantina Kornaros Michael MDPI Cheese whey Anaerobic digestion Liquid cow manure Easily biodegradable substrates Single-stage Two-stage process