2026-04-27T21:58:19Zhttps://uvadoc.uva.es/oai/request

oai:uvadoc.uva.es:10324/464662025-02-20T07:11:53Zcom_10324_35294com_10324_952com_10324_894col_10324_35295

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 Toledo Cervantes, Alma Posadas Olmos, Esther Bertol, Isabel Turiel Santos, Sara Alcoceba, Ana Muñoz Torre, Raúl 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. 2021-05-04T12:39:27Z 2021-05-04T12:39:27Z 2019 info:eu-repo/semantics/article Algal Research, 2019, vol. 44. 8 p. 2211-9264 http://uvadoc.uva.es/handle/10324/46466 10.1016/j.algal.2019.101672 eng https://www.sciencedirect.com/science/article/pii/S2211926419302681?via%3Dihub info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-nd/4.0/ © 2019 Elsevier Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier SI