Lookup NU author(s): Dr Sharon Velasquez Orta,
Dr Peter Leary
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND).
© 2019Currently over 80% of wastewater generated globally, is discharged into surface waters without adequate treatment. Major environmental and public health risks associated with such releases are particularly prevalent in developing countries where the infrastructure and financing for effective treatment is lacking. Novel low cost integrated wastewater treatment and biorefinery processes could provide a sustainable solution. This study investigated, for the first time, the feasibility of simultaneous wastewater treatment and bioethanol production in non-sterile, heterotrophic bioreactors using either microalgae, wild yeast, or a co-culture of microalgae and wild yeast. Scenedesmus sp. are known to achieve high biomass concentrations under sterile heterotrophic conditions. However, under the non-sterile conditions proposed, relatively low nutrient removal rates (60% nitrate, 53% total ammonia nitrogen (TAN) and 46% orthophosphate) and biomass yields (0.98 ± 0.10 g/L) were achieved. Wastewater grown microalgae and yeast co-cultures achieved high nutrient removal rates (96% nitrate, 100% TAN and 93% orthophosphate). Wastewater grown yeast cultures produced consistently promising results, achieving high biomass concentrations of 3.7 ± 0.1 and 4.2 ± 0.1 g/L along with 100% nitrate, 100% TAN and 92.6% orthophosphate removal. Yeast provided the additional advantage of aerobic fermentation, possibly allowing integrated wastewater treatment and bioethanol production.
Author(s): Walls L, Velasquez-Orta SB, Romero-Frasca E, Leary P, Noguez IY, Ledesma MT
Publication type: Article
Publication status: Published
Journal: Biochemical Engineering Journal
Online publication date: 15/11/2019
Acceptance date: 25/07/2019
Date deposited: 22/10/2019
ISSN (electronic): 1369-703X
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