International Journal of Chemical Engineering (Jan 2014)

Growing Chlorella vulgaris in Photobioreactor by Continuous Process Using Concentrated Desalination: Effect of Dilution Rate on Biochemical Composition

  • Ângelo Paggi Matos,
  • Regina Coeli de Oliveira Torres,
  • Luiz Rodrigo Ito Morioka,
  • Elisa Helena Siegel Moecke,
  • Kepler Borges França,
  • Ernani Sebastião Sant’Anna

DOI
https://doi.org/10.1155/2014/310285
Journal volume & issue
Vol. 2014

Abstract

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Desalination wastewater, which contains large amount of salt waste, might lead to severely environmental pollution. This study evaluated the effect of dilution rate (0.1≤D≤0.3 day−1) on microalgal biomass productivity, lipid content, and fatty acid profile under steady-state condition of Chlorella vulgaris supplemented with concentrated desalination. Continuous culture was conducted for 55 days. Results show that the biomass productivity (Px) varied from 57 to 126 mg L−1 d−1 (dry mass) when the dilution rate ranged from 0.1 to 0.3 day−1. At lowest dilution rate (D=0.1 day−1), the continuous culture regime ensured the highest values of maximum biomass concentration (Xm=570±20 mL−1) and protein content (52%). Biomass lipid content was an increasing function of D. The most abundant fatty acids were the palmitic (25.3±0.6%) at D=0.1 day−1 and the gamma-linolenic acid (23.5±0.1%) at D=0.3 day−1 ones. These fatty acids present 14 to 18 carbons in the carbon chain, being mainly saturated and polyunsaturated, respectively. Overall, the results show that continuous culture is a powerful tool to investigate the cell growth kinetics and physiological behaviors of the algae growing on desalination wastewater.