The present work investigated the efficiency of algal flocs biomass for the treatment of primary and secondary effluent in static and mixing conditions under different hydraulic retention time (HRT). Primary effluent fed cultures created a high-density biomass of 2.8 and 3.8 g L-1 under static and mixing conditions, respectively. Secondary effluent was more effective in order to create even higher density biomass of 7.8 and 6 g L-1 under static and mixing conditions, respectively. The algal floc biomass developed was quite effective for organic matter and nutrient removal. Primary effluent fed cultures seemed to be more efficient for chemical oxygen demand (COD) and ammonia nitrogen removal, while secondary effluent fed cultures for nitrates removal. At an HRT of 8 days using primary effluent, the removal of COD, ammonia nitrogen and total phosphorus was 86.2, 100 and 97.4%, respectively. The cultures fed with secondary effluent, even at low HRT of 1.2 days, achieved removals of 88.4, 77.5, 100 and 98.6% for COD, nitrates, ammonia, and total phosphorus, respectively.
Supplementary information: The online version contains supplementary material available at 10.1007/s10811-023-02931-2.
Keywords: Biomass characteristics; Kinetics; Nutrient uptake; Wastewater treatment; Μicroalgae.
© The Author(s), under exclusive licence to Springer Nature B.V. 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.