title: Nutrient removal and microalgal biomass production on urine in a short light-path photobioreactor.
abstract: Due to the high nitrogen and phosphorus content, source-separated urine can serve as a major nutrient source for microalgae production. The aim of this study was to evaluate the nutrient removal rate and the biomass production rate of Chlorella sorokiniana being grown continuously in urine employing a short light-path photobioreactor. The results demonstrated, for the first time, the possibility of continuous microalgae cultivation in human urine. The lowest dilution factor successfully employed was a factor of 2 (50% v/v urine). Microalgae dominated a smaller bacterial population and were responsible for more than 90% of total nitrogen and phosphorus removal. With a light-path of 10 mm, a maximum volumetric biomass productivity as high as 9.3 g L(-1) d(-1) was achieved. The co-existing bacterial population removed up to 70% of organic pollutants from the urine at a rate of 1300 mg COD L(-1) d(-1). Enriching the urine with magnesium, adjusting the N:P molar ratio, and shortening the reactor light-path further increased the volumetric biomass productivity to 14.8 g L(-1) d(-1). The corresponding nitrogen and phosphorus removal rates were 1300 and 150 mg L(-1) d(-1), respectively. The subsequently produced biomass contained 43-53% w/w proteins and 16-25% w/w total fatty acids.
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, The Netherlands. Electronic address: kanjana.tuantet@wur.nl.
authors.forename: Kanjana
authors.initials: K
authors.lastname: Tuantet
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, The Netherlands.
authors.forename: Hardy
authors.initials: H
authors.lastname: Temmink
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, The Netherlands.
authors.forename: Grietje
authors.initials: G
authors.lastname: Zeeman
authors.affiliation: Bioprocess Engineering, AlgaePARC, Wageningen University, The Netherlands(1).
authors.forename: Marcel
authors.initials: M
authors.lastname: Janssen
authors.affiliation: Bioprocess Engineering, AlgaePARC, Wageningen University, The Netherlands(1).
authors.forename: René H
authors.initials: RH
authors.lastname: Wijffels
authors.affiliation: Sub-department of Environmental Technology, Wageningen University, The Netherlands.
authors.forename: Cees J N
authors.initials: CJ
authors.lastname: Buisman
mesh_terms: D018533:Biomass; D002708:Chlorella / Q000378:metabolism; D006801:Humans; D058086:Microalgae / Q000378:metabolism*; D058433:Photobioreactors / Q000382:microbiology*; D014556:Urine
keywords: Chlorella sorokiniana; Microalgae productivity; Nutrient removal; Short light-path photobioreactor; Source-separated urine