Assessing the influence of the hydraulic retention time and carbon/nitrogen ratio on urban wastewater treatment in a new anoxic-aerobic algal-bacterial photobioreactor configuration
Autor: | Isabel Bertol, Esther Posadas, Ana Alcoceba, Raúl Muñoz, Alma Toledo-Cervantes, Sara Turiel |
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Rok vydání: | 2019 |
Předmět: |
Suspended solids
education.field_of_study Carbon-to-nitrogen ratio Hydraulic retention time Chemistry 0208 environmental biotechnology Chemical oxygen demand Population Fotobiorreactor anóxico-aerobio Photobioreactor 02 engineering and technology 010501 environmental sciences 01 natural sciences 020801 environmental engineering Relación carbono/nitrógeno Animal science Anoxic-aerobic photobioreactor Wastewater Procesos alga-bacteria Sewage treatment Algal-bacterial processes education Agronomy and Crop Science 0105 earth and related environmental sciences |
Zdroj: | UVaDOC. Repositorio Documental de la Universidad de Valladolid instname UVaDOC: Repositorio Documental de la Universidad de Valladolid Universidad de Valladolid |
Popis: | Producción Científica The influence of the hydraulic retention time (HRT) (2 and 4 days) and the carbon/nitrogen ratio (C/N) (7, 8 and 9) of the wastewater on the treatment of synthetic domestic wastewater was evaluated in a new anoxic-aerobic algal-bacterial photobioreactor configuration operated at solids retention time of 10 d by biomass recycling and withdrawal. The removal of chemical oxygen demand remained between 84% and 89% regardless of the operational conditions. However, the decrease in the HRT from 4 to 2 d entailed reductions in the removal of total nitrogen (TN) and P-PO43− from 87 ± 2% to 62 ± 2% and from 22 ± 5% to 11 ± 1%, respectively. On the other hand, the decrease in the C/N ratio of the wastewater from 9 to 8 and 7 at a HRT of 2 d induced TN removals of 62 ± 4% and 48 ± 4%, respectively. In contrast, P-PO43- removals unexpectedly increased from 11 ± 1% at a C/N ratio of 9 to 53 ± 3% and 47 ± 5% at C/N ratios of 8 and 7, respectively. Finally, biomass settling and recycling supported the enrichment of an algal-bacterial population with good settleability characteristics (suspended solids removals in the settler ∼98%), being Chlorella vulgaris the dominant microalga specie at a C/N ratio of 9 which was gradually replaced by Phormidium sp., as a result of the reduction in the C/N ratio of the wastewater. Junta de Castilla y León - Fondo Europeo de Desarrollo Regional (projects CLU-2017-09 and UIC 71) CEMIE-Bio (project 247006) |
Databáze: | OpenAIRE |
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