title: Recycling harvest water to cultivate Chlorella zofingiensis under nutrient limitation for biodiesel production.
abstract: Harvest water recycling for Chlorella zofingiensis re-cultivation under nutrient limitation was investigated. Using 100% harvest water, four cultures were prepared: Full medium, P-limited medium, N-limited medium and N- and P-limited medium, while another full medium was also prepared using 50% harvest water. The results showed that the specific growth rate and biomass productivity ranged from 0.289 to 0.403 day(-1) and 86.30 to 266.66 mg L(-1) day(-1), respectively. Nutrient-limited cultures witnessed much higher lipid content (41.21-46.21% of dry weight) than nutrient-full cultures (26% of dry weight). The N- and P-limited medium observed the highest FAME yield at 10.95% of dry weight, while the N-limited culture and P-limited culture shared the highest biodiesel productivity at 20.66 and 19.91 mg L(-1) day(-1), respectively. The experiment on harvest water recycling times demonstrated that 100% of the harvest water could be recycled twice with the addition of sufficient nutrients.
authors.affiliation: Faculty of Technology, University of Vaasa and Vaasa Energy Institute, FI-65101 Vaasa, Finland. liandongzhu@gmail.com
authors.forename: L D
authors.initials: LD
authors.lastname: Zhu
authors.forename: J
authors.initials: J
authors.lastname: Takala
authors.forename: E
authors.initials: E
authors.lastname: Hiltunen
authors.forename: Z M
authors.initials: ZM
authors.lastname: Wang
mesh_terms: D000818:Animals; D056804:Biofuels; D018533:Biomass; D002708:Chlorella / Q000254:growth & development*; D004952:Esters / Q000032:analysis; D008055:Lipids / Q000096:biosynthesis; D009584:Nitrogen / Q000032:analysis / Q000172:deficiency*; D010758:Phosphorus / Q000032:analysis / Q000172:deficiency*; D059027:Recycling; D034421:Sus scrofa; D062065:Wastewater / Q000737:chemistry*
chemical_list: D056804:Biofuels; D004952:Esters; D008055:Lipids; D009584:Nitrogen; D010758:Phosphorus; D062065:Wastewater
keywords: Biodiesel production; Chlorella zofingiensis; Harvest water recycling; Microalgae; Nutrient limitation