title: Synergistic effects and optimization of nitrogen and phosphorus concentrations on the growth and nutrient uptake of a freshwater Chlorella vulgaris.
abstract: The synergistic effects and optimization of nitrogen (N) and phosphorus (P) concentrations on the growth of Chlorella vulgaris (CCAP 211/11B, CS-42) and nutrient removal have been investigated under different concentrations of N (0-56 mg/L) and P (0-19 mg/L). The study showed that N/P ratio has a crucial effect on the biomass growth and nutrient removal. When N/P=10, a complete P and N removal was achieved at the end of cultivation with specific growth rate (SGR) of 1 d-1and biomass concentration of 1.58 g/L. It was also observed that when the N content <2.5 mg/L, the SGR significantly reduced from 1.04 to 0.23 d-1and the maximum biomass produced was decreased more than three-fold to 0.5 g/L. The Box-Behnken experimental design and response surface method were used to study the effects of the initial concentrations (P, N and C) on P and N removal efficiencies. The optimized P, N and C concentrations supporting 100% removal of both P and N at an SGR of 0.95 were 7, 55 and 10 mg/L respectively, with desirability value of 0.94. The results and analysis obtained could be very useful when applying the microalgae for efficient wastewater treatment and nutrient removal.
authors.affiliation: a Department of Chemical Engineering , Curtin University , Perth , WA , Australia.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Alketife
authors.affiliation: b Chemical Engineering Department , Qatar University , Doha, Qatar.
authors.forename: Simon
authors.initials: S
authors.lastname: Judd
authors.affiliation: a Department of Chemical Engineering , Curtin University , Perth , WA , Australia.
authors.forename: Hussein
authors.initials: H
authors.lastname: Znad
mesh_terms: D018533:Biomass; D048408:Chlorella vulgaris / Q000187:drug effects* / Q000254:growth & development; D004357:Drug Synergism; D005618:Fresh Water; D058086:Microalgae / Q000187:drug effects / Q000254:growth & development; D009584:Nitrogen / Q000494:pharmacology*; D010758:Phosphorus / Q000494:pharmacology*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000494:pharmacology*
chemical_list: D014874:Water Pollutants, Chemical; D010758:Phosphorus; D009584:Nitrogen
keywords: Box–Behnken design; Chlorella vulgaris; nutrient removal; optimization