RT info:eu-repo/semantics/article
T1 Photosynthetic upgrading of biogas from anaerobic digestion of mixed sludge in an outdoors algal-bacterial photobioreactor at pilot scale
A1 Méndez, Lara
A1 García, Dimas
A1 Pérez, Enrique
A1 Blanco, Saúl
A1 Muñoz Torre, Raúl
K1 Photobioreactors
K1 Fotobioreactores
K1 Biogas
K1 Biogás
K1 Biomethane
K1 Biometano
AB Anaerobic digestion can biotransform the biodegradable fraction of sewage sludge into biogas, while the symbiotic action of algal-bacterial consortia can remove both the CO2 and H2S from biogas and nutrients from digestate. A 100 L anaerobic digester operated at 20 days of retention time coupled with a 180 L high-rate algal pond (HRAP) engineered to upgrade the biogas and treat the liquid fraction of the pilot digester was optimized along four operational stages: (I) operation with a greenhouse during winter; (II) operation without greenhouse; (III) process supplementation with NaHCO3; (IV) process supplementation with Na2CO3. The biogas produced was composed of 63.7 ± 2.9% CH4, 33.7 ± 1.9% CO2, 0.5 ± 0.3% O2 and 1.6 ± 1.1% N2. An average methane productivity of 324.7 ± 75.8 mL CH4 g VSin−1 and total COD removals of 48 ± 20% were recorded in the digester. The CH4 concentration in the biomethane gradually decreased to 87.6 ± 2.0% and 85.1 ± 1.3% at the end of stage I and II, respectively, attributed to the loss of inorganic carbon in the HRAP. The supplementation of NaHCO3 and Na2CO3 mediated an increase in the CH4 content to 90.4 ± 1.5 and 91.2 ± 0.7% in stages III and IV, respectively. Steady state CO2 removals of 90% and 88% in stages I and II, and 95.7 and 97.6% in stages III and IV, respectively, were recorded. A constant biomass productivity of 22 g m−2 d−1, set by daily harvesting 26.5 g dry algal-bacterial biomass from the bottom of the settler, was maintained concomitantly with a complete removal of the N and P supplied via centrate.
PB Elsevier
SN 2214-7144
YR 2022
FD 2022
LK https://uvadoc.uva.es/handle/10324/53596
UL https://uvadoc.uva.es/handle/10324/53596
LA eng
NO Journal of Water Process Engineering, 2022, vol. 48, 102891
NO Producción Científica
DS UVaDOC
RD 25-abr-2024