Το work with title Enhanced biogas production in pilot digesters treating a mixture of olive mill wastewater and agro-industrial or agro-livestock by-products in Greece by Thanos Dimitris, Maragkaki Angeliki, Venieri Danai, Fountoulakis, Michael, Manios Thrassyvoulos is licensed under Creative Commons Attribution 4.0 International
Bibliographic Citation
D. Thanos, A. Maragkaki, D. Venieri, M. Fountoulakis, and T. Manios, “Enhanced biogas production in pilot digesters treating a mixture of olive mill wastewater and agro-industrial or agro-livestock by-products in Greece,” Waste Biomass Valor., vol. 12, no. 1, pp. 135–143, Jan. 2021. doi: 10.1007/s12649-020-00963-0
https://doi.org/10.1007/s12649-020-00963-0
The selection of appropriate co-substrates is very important to the feasibility of an anaerobic co-digestion process. A proper choice of co-substrate compositions leads to system balance and increased methane generation. To valorize agricultural wastes and byproducts in southern Greece, anaerobic co-digestion of four feedstocks (olive mill wastewater—OMW, poultry manure—PM, liquid pig manure—LPM, and cheese whey—CW) was studied to produce biogas for renewable energy generation. Pilot- scale continuous co-digestion approaches were adopted to carry out the investigation under mesophilic temperatures (35 ± 2 °C) for 30 days. The feedstocks were mixed at different percentages according to their availabilities in southern Greece with a total solids (TS) ratio of approximately 10% and an OLR of 2.2 kg VS m−3 day−1. The main agro-industrial feedstock of this study is OMW. Two types of influent feedstock were utilized: a mixture of 30% v/v OMW and 70% PM and LPM, and a mixture of 40% v/v of OMW and 60% PM and CW. Therefore, optimization of biogas production from OMW was attempted by co-digesting with PM and LPM or CW. The aim of this study was to investigate the effect of different liquid feedstocks in order to have a total solids (TS) ratio of approximately 10%. Reduction in the volatile solids ranged between 50 and 57%. The average removal of dissolved chemical oxygen demand (COD) was 50% and 58% for the two examined scenarios, while the biogas production rate at the steady state reached 0.7 ± 0.4 and 1.2 ± 0.3 L/Lreactor/day respectively.