title: Nitrification and microalgae cultivation for two-stage biological nutrient valorization from source separated urine.
abstract: Urine contains the majority of nutrients in urban wastewaters and is an ideal nutrient recovery target. In this study, stabilization of real undiluted urine through nitrification and subsequent microalgae cultivation were explored as strategy for biological nutrient recovery. A nitrifying inoculum screening revealed a commercial aquaculture inoculum to have the highest halotolerance. This inoculum was compared with municipal activated sludge for the start-up of two nitrification membrane bioreactors. Complete nitrification of undiluted urine was achieved in both systems at a conductivity of 75mScm(-1) and loading rate above 450mgNL(-1)d(-1). The halotolerant inoculum shortened the start-up time with 54%. Nitrite oxidizers showed faster salt adaptation and Nitrobacter spp. became the dominant nitrite oxidizers. Nitrified urine as growth medium for Arthrospira platensis demonstrated superior growth compared to untreated urine and resulted in a high protein content of 62%. This two-stage strategy is therefore a promising approach for biological nutrient recovery.
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Joeri
authors.initials: J
authors.lastname: Coppens
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Ralph
authors.initials: R
authors.lastname: Lindeboom
authors.affiliation: Research Group of Sustainable Energy, Air and Water Technology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Maarten
authors.initials: M
authors.lastname: Muys
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Wout
authors.initials: W
authors.lastname: Coessens
authors.affiliation: Research Group of Sustainable Energy, Air and Water Technology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium.
authors.forename: Abbas
authors.initials: A
authors.lastname: Alloul
authors.affiliation: Technologiecluster Bioengineering Technologie, KU Leuven, Jan De Nayerlaan 5, 2860 Sint-Katelijne-Waver, Belgium.
authors.forename: Ken
authors.initials: K
authors.lastname: Meerbergen
authors.affiliation: Technologiecluster Bioengineering Technologie, KU Leuven, Jan De Nayerlaan 5, 2860 Sint-Katelijne-Waver, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Lievens
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Clauwaert
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Nico
authors.initials: N
authors.lastname: Boon
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium; Research Group of Sustainable Energy, Air and Water Technology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium. Electronic address: Siegfried.Vlaeminck@Uantwerpen.be.
authors.forename: Siegfried E
authors.initials: SE
authors.lastname: Vlaeminck
mesh_terms: D017756:Aquaculture; D019149:Bioreactors; D058086:Microalgae / Q000254:growth & development / Q000378:metabolism*; D058465:Nitrification; D009573:Nitrites / Q000378:metabolism; D009576:Nitrobacter / Q000254:growth & development / Q000378:metabolism*; D010084:Oxidation-Reduction; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D053545:Spirulina / Q000254:growth & development / Q000378:metabolism; D014556:Urine / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D009573:Nitrites; D012722:Sewage; D062065:Wastewater
keywords: Nitrogen recovery; Salt adaptation; Single cell protein; Source separation; Spirulina