Photorespiration in an outdoor alkaline open-photobioreactor used for biogas upgrading.
Sci Total Environ
; 667: 613-621, 2019 Jun 01.
Article
em En
| MEDLINE
| ID: mdl-30833260
The rates of oxygenic and carbon fixation photosynthetic processes of a microalgae consortium were simultaneously evaluated under steady-state performance in an bench scale alkaline open-system exposed to outdoor conditions in Mexico City. A synthetic methane-free gaseous stream (SMGS) similar to biogas was used as inorganic carbon source and model of biogas upgrading. The microalgae CO2 fixation rates were calculated through a novel methodology based on an inorganic carbon mass balance under continuous scrubbing of a SMGS similar to biogas, where the influence of pH and temperature time-depended oscillations were successfully incorporated into the mass balances. The oxygenic activity and carbon fixation occurred at different non-stoichiometric rates during the diurnal phase, in average carbon fixation predominated over oxygen production (photosynthesis quotient PQ≈ 0.5â¯mol O2 mol-1 CO2) indicating photorespiration occurrence mainly under dissolved oxygen concentrations higher than 10â¯mgâ¯L-1. The oxygen and inorganic carbon mass balances demonstrated that photorespiration and endogenous respiration were responsible for losing up to 66% and 7% respectively of the biomass grew at diurnal periods under optimal conditions. In favoring photorespiration conditions, the microalgae biomass productivity (CO2 effectively captured) can be severely decreased. A kinetic mathematical model as a function of temperature and irradiance of the oxygenic photosynthetic activity indicated the optimal operation zone for this outdoor alkaline open-photobioreactor, where irradiance was found being the most influential parameter.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Biocombustíveis
/
Fotobiorreatores
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
México
País de publicação:
Holanda