Cloud point extraction of microalgae cultures

Publikationstyp
Journal Article
Date Issued
2012-10-23
Sprache
English
Author(s)
Glembin, Philipp  
Kerner, Martin  
Smirnova, Irina  orcid-logo
Institut
Thermische Verfahrenstechnik V-8  
TORE-URI
http://hdl.handle.net/11420/10426
Journal
Separation and purification technology  
Volume
103
Start Page
21
End Page
27
Citation
Separation and Purification Technology 103 (): 21-27 (2013)
Publisher DOI
10.1016/j.seppur.2012.10.017
Scopus ID
2-s2.0-84868549271
Publisher
Elsevier Science
The micellar in situ extraction of hydrophobic compounds from microalgae cultures (Chlamydomonas reinhardtii, Chlorella vulgaris, Scenedesmus obliquus) using nonionic surfactants (Triton X-114, Tergitol TMN 6, Tergitol 15-s-7) was studied in lab- and pilot scale. Therefore, phase separation behavior of the cloud point systems as well as the biocompatibility of the surfactants was investigated. It was shown that algae cells are concentrated in the aqueous phase, whereas the hydrophobic compounds (fatty acids) are enriched in the micellar phase. The thermodynamic model COSMO-RS was used to calculate partitioning coefficients of fatty acids between the phases. The biocompatibility of the surfactants applied was studied by monitoring the photosynthetic activity of algae upon contact with surfactants using puls amplitude modulation. Significant differences in growth and the photosynthetic activity of different algae strains after exposure to surfactants were determined. Whereas the photosynthetic activity of C. reinhardtii decreased rapidly upon contact with surfactants, the photosynthetic activity of S. obliquus, was 90% in comparison to a control after exposure for 240 min to all tested surfactants. C. vulgaris showed an intermediate decrease. Thus, besides extraction, surfactants might be applied to control the growth of certain algae enabling the monoalgal culturing in outdoor cultivation of microalgae since the growth of the less surfactant-tolerant microalgae could be suppressed. Overall, the results indicate that a micellar extraction with nonionic surfactants offers the opportunity for an in situ extraction of hydrophobic substances directly from the culture medium and might be a promising alternative to a classic solvent extraction of dried algal biomass.
Subjects
Cloud point system
In situ separation
Microalgae
Nonionic surfactants
Phase separation
DDC Class
600: Technik
620: Ingenieurwissenschaften