2026-04-27T21:42:50Zhttps://uvadoc.uva.es/oai/request

oai:uvadoc.uva.es:10324/467522022-07-18T09:33:09Zcom_10324_35294com_10324_952com_10324_894col_10324_35295

Rodríguez Muñoz, Yadira Firmino, Paulo Igor Milen Pérez, Víctor Lebrero Fernández, Raquel Muñoz Torre, Raúl Producción Científica Creating additional value out of biogas during waste treatment has become a priority in past years. Biogas bioconversion into valuable bioproducts such as biopolymers has emerged as a promising strategy. This work assessed the operational feasibility of a bubble column bioreactor (BCB) implemented with gas recirculation and inoculated with a polyhydroxybutyrate (PHB)-producing strain using biogas as substrate. The BCB was initially operated at empty bed residence times (EBRTs) ranging from 30 to 120 min and gas recirculation ratios (R) from 0 to 30 to assess the gas-to-liquid mass transfer and bioconversion of CH4. Subsequently, the BCB was continuously operated at a R of 30 and an EBRT of 60 min under excess of nitrogen and nitrogen feast-famine cycles of 24 h:24 h to trigger PHB synthesis. Gas recirculation played a major role in CH4 gas–liquid transfer, providing almost fourfold higher CH4 elimination capacities (~41 g CH4 m−3 h−1) at the highest R and EBRT of 60 min. The long-term operation under N excess conditions entailed nitrite accumulation (induced by O2 limiting conditions) and concurrent methanotrophic activity inhibition above ~60 mg N-NO2− L−1. Adjusting the N-NO3− supply to match microbial N demand successfully prevented nitrite accumulation. Finally, the N feast-famine 24 h:24 h strategy supported a stable CH4 conversion with a removal efficiency of 70% along with a continuous PHB production, which yielded PHB accumulations of 14.5 ± 2.9% (mg PHB mg−1 total suspended solids × 100). These outcomes represent the first step towards the integration of biogas biorefineries into conventional anaerobic digestion plants. 2021-06-04 2021-06-04 2020 info:eu-repo/semantics/article Waste Management, 2020, vol. 113, p. 395-403 0956-053X https://uvadoc.uva.es/handle/10324/46752 10.1016/j.wasman.2020.06.009 395 403 Waste Management 113 eng https://www.sciencedirect.com/science/article/abs/pii/S0956053X20303196 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-nd/4.0/ © 2020 Elsevier Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier