Effect of hydraulic retention time and treated urban wastewater ratio on progressive adaptation of an inoculated microalgae in membrane photobioreactors Díaz, Verónica Antiñolo, Laura Poyatos, José Manuel Muñío, María del Mar Martín-Pascual, Jaime Photobioreactor Microalgae Adaptation Biomass Nutrient removal Currently, there is a growing concern about water scarcity. The rising demand for wastewater treatment systems that facilitate the reuse of wastewater has resulted in a focus on the use of microalgae in sustainable treatments. These methods not only eliminate nutrients from the wastewater but also produce biomass that can be used to obtain high-value products. This study aimed to observe the effect of different hydraulic retention times (HRTs) and treated urban wastewater (TUWW) percentages on the growth of microalgae biomass and nutrient consumption in membrane photobioreactors. Microalgae biomass growth increases with HRT regardless of the percentage of TUWW. Biomass concentration stabilises at between 40% and 60% TUWW but significantly increases when 100% TUWW is used, resulting in the highest biomass concentrations. As HRT increases, ammonium and total nitrogen consumption also rise. A positive trend in ammonium consumption was observed with increasing TUWW, reaching its peak with 100% TUWW. The optimal conditions for biomass growth and nutrient removal are achieved with a 7-day HRT and 100% TUWW as influent, which was confirmed as optimal with the response surface methodology. 2024-11-04T07:29:13Z 2024-11-04T07:29:13Z 2024-12 journal article https://hdl.handle.net/10481/96559 https://doi.org/10.1016/j.jenvman.2024.123005 eng MCIN/AEI/10.13039/501100011033 and by the Junta de Andalucía and the European Regional Development Fund (ERDF) [P18-TP-4732]. Grant PID2021-124740NB-I00 funded by MCIN/AEI/10.13039/501100011033/and by FEDER, UE (and by ERDF, EU). http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional ELSEVIER