title: Performance of a microalgal photobioreactor treating toilet wastewater: Pharmaceutically active compound removal and biomass harvesting.
abstract: In this study, a 1200L outdoor pilot scale microalgal photobioreactor (PBR) was used for toilet wastewater (WW) treatment and evaluate its ability to remove pharmaceutically active compounds (PhACs). The PBR was operated at two different hydraulic retention times (HRTs), which were 8 and 12days, during Period I (September-October) and Period II (October-December), respectively. Algal biomass concentrations varied by operating period because of seasonal changes. Nutrients (ammonia, nitrogen and total phosphorous) and chemical oxygen demand (COD) were monitored and efficiently removed in both periods (>80%), attaining the legislation limits. At the theoretical hydraulic steady state in both periods, pharmaceutical removal reached high levels (>48%). Two harvesting techniques were applied to the PBR microalgae effluent. Gravity sedimentation was efficient for biomass removal (>99% in 7min) in Period I when large particles, flocs and aggregates were present. In contrast, a longer sedimentation time was required when biomass was mainly composed of single cells (88% clarification in a 24h in Period II). The second harvesting technique investigated was the co-pelletization of algal biomass with the ligninolytic fungus Trametes versicolor, attaining >98% clarification for Period II biomass once pellets were formed. The novel technology of co-pelletization enabled the complete harvesting of single algae cells from the liquid medium in a sustainable way, which benefits the subsequent use of both biomass and the clarified effluent.
authors.affiliation: Chemical, Biological and Environmental Engineering Department, Escola d'Enginyeria, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
authors.forename: Andrea
authors.initials: A
authors.lastname: Hom-Diaz
authors.affiliation: Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, Girona, Spain.
authors.forename: Adrián
authors.initials: A
authors.lastname: Jaén-Gil
authors.affiliation: Chemical, Biological and Environmental Engineering Department, Escola d'Enginyeria, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
authors.forename: Iris
authors.initials: I
authors.lastname: Bello-Laserna
authors.affiliation: Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, Girona, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Rodríguez-Mozaz
authors.affiliation: Chemical, Biological and Environmental Engineering Department, Escola d'Enginyeria, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Vicent
authors.affiliation: Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, Girona, Spain; Water and Soil Quality Research Group, Department of Environmental Chemistry (IDAEA-CSIC), Barcelona, Spain.
authors.forename: Damià
authors.initials: D
authors.lastname: Barceló
authors.affiliation: Chemical, Biological and Environmental Engineering Department, Escola d'Enginyeria, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain. Electronic address: paqui.blanquez@uab.cat.
authors.forename: Paqui
authors.initials: P
authors.lastname: Blánquez
mesh_terms: D018533:Biomass; D058086:Microalgae; D058433:Photobioreactors; D055454:Trametes; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater
chemical_list: D062065:Wastewater
keywords: Microalgae; Microalgae harvesting; Pharmaceutical removal; Photobioreactor; Wastewater treatment