Foam fractionator as a tool to remove dissolved organic matter and improve the flocculation of the marine microalga Nannochloropsis oceanica

  • Milene RoseletEmail author
  • Fabio Roselet
  • Paulo Cesar Abreu


Microalgae have great biotechnological potential, yet they are difficult to harvest. Flocculation is a promising technology, but the dissolved organic matter (DOM) released by microalgae during growth interacts with the flocculant, hindering the process. This DOM is composed mostly of proteins and carbohydrates which may present a polarity ranging from hydrophobic to hydrophilic. In aquaculture, foam fractionators are routinely employed to remove DOM from cultures, improving the water quality. However, this equipment has never been employed in microalgae cultures. Therefore, the present study aimed to evaluate the use of the foam fractionator to remove DOM from a Nannochloropsis oceanica culture to improve the flocculation process. First, DOM accumulation was monitored for 33 days in a 330 L outdoor culture to characterize the dissolved organic carbon (DOC) and protein and carbohydrate contents. Samples from logarithmic (day 13) and stationary (day 29) growth phases were fractionated by polarity (hydrophobic, transphilic, and hydrophilic), the DOC and protein and carbohydrate contents of each fraction were measured, and flocculation was performed. Then the culture was treated with a foam fractionator at bench (11 L) and pilot scales (1600 L), and the composition and flocculation were compared with the non-treated culture. Proteins strongly hindered flocculation, and the foam fractionator was effective in removing this element and significantly improved the flocculation efficiency. Furthermore, N. oceanica cell integrity was not affected by the foam fractionator. These results indicate that DOM can be efficiently removed by foam fractionation, improving the microalgae harvesting process.


Nannochloropsis oceanica Foam fractionator Dissolved organic matter Flocculation 



The authors would like to thank Professor Adalto Bianchini, Dr. Patrícia Costa, and Dr. Cinthia da Silva for their support in the analysis of dissolved organic carbon and proteins. Also, to M.Sc. Bruno Kubelka and M.Sc. Bruno Cruz for maintaining the photobioreactors.

Funding information

M. Roselet was funded by a M.Sc. grant from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Process no. 1647027). P.C. Abreu is a research fellow at the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). F. Roselet is a postdoctoral fellow at the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Process no. 150531/2016-8).

Supplementary material

10811_2019_1801_MOESM1_ESM.pdf (3.6 mb)
ESM 1 (PDF 3.56 mb)


  1. Andersen RA (ed) (2005) Algal culturing techniques. Elsevier/Academic Press, BurlingtonGoogle Scholar
  2. Borowitzka MA (2013) High-value products from microalgae—their development and commercialisation. J Appl Phycol 25:743–756CrossRefGoogle Scholar
  3. Børsheim KY, Vadstein O, Myklestad SM, Reinertsen H, Kirkvold S, Olsen Y (2005) Photosynthetic algal production, accumulation and release of phytoplankton storage carbohydrates and bacterial production in a gradient in daily nutrient supply. J Plankton Res 27:743–755CrossRefGoogle Scholar
  4. Brown MR (1991) The amino-acid and sugar composition of 16 species of microalgae used in mariculture. J Exp Mar Biol Ecol 145:79–99CrossRefGoogle Scholar
  5. Edzwald JK (1993) Coagulation in drinking water treatment: particles, organics and coagulants. Water Sci Technol 27:21–35CrossRefGoogle Scholar
  6. Faé Neto WA, Borges Mendes CR, Abreu PC (2018) Carotenoid production by the marine microalgae Nannochloropsis oculata in different low-cost culture media. Aquac Res 49:2527–2535CrossRefGoogle Scholar
  7. Garzon-Sanabria AJ, Ramirez-Caballero SS, Moss FEP, Nikolov ZL (2013) Effect of algogenic organic matter (AOM) and sodium chloride on Nannochloropsis salina flocculation efficiency. Bioresour Technol 143:231–237CrossRefGoogle Scholar
  8. Ghernaout D (2014) The hydrophilic/hydrophobic ratio vs. dissolved organics removal by coagulation – a review. J King Saud Univ - Sci 26:169–180CrossRefGoogle Scholar
  9. Greenwell HC, Laurens LML, Shields RJ, Lovitt RW, Flynn KJ (2010) Placing microalgae on the biofuels priority list: a review of the technological challenges. J R Soc Interface 7:703–726CrossRefGoogle Scholar
  10. Gregory J (2013) Flocculation fundamentals. In: Encyclopedia of colloid and interface science. Springer, Berlin, pp 459–491CrossRefGoogle Scholar
  11. Henderson RK, Baker A, Parsons SA, Jefferson B (2008a) Characterisation of algogenic organic matter extracted from cyanobacteria, green algae and diatoms. Water Res 42:3435–3445CrossRefGoogle Scholar
  12. Henderson RK, Parsons SA, Jefferson B (2008b) The impact of algal properties and pre-oxidation on solid–liquid separation of algae. Water Res 42:1827–1845CrossRefGoogle Scholar
  13. Henderson RK, Parsons SA, Jefferson B (2010) The impact of differing cell and algogenic organic matter (AOM) characteristics on the coagulation and flotation of algae. Water Res 44:3617–3624CrossRefGoogle Scholar
  14. Kubelka BG, Pinto WT, Abreu PC (2017) Hydrodynamic performance of two air nozzles diameters on the massive microalgae culture: computational and experimental approaches. Algal Res 27:318–324CrossRefGoogle Scholar
  15. Lekang OI (2013) Aquaculture engineering: second edition. John Wiley & Sons, OxfordCrossRefGoogle Scholar
  16. Leloup M, Nicolau R, Pallier V, Yéprémian C, Feuillade-Cathalifaud G (2013) Organic matter produced by algae and cyanobacteria: quantitative and qualitative characterization. J Environ Sci 25:1089–1097CrossRefGoogle Scholar
  17. Malcolm RL, MacCarthy P (1992) Quantitative evaluation of XAD-8 and XAD-4 resins used in tandem for removing organic solutes from water. Environ Int 18:597–607CrossRefGoogle Scholar
  18. Mathimani T, Bhumathi D, Shan Ahamed T, Dineshbabu G, Deviram G, Uma L, Prabaharan D (2017) Semicontinuous outdoor cultivation and efficient harvesting of marine Chlorella vulgaris BDUG 91771 with minimum solid co-precipitation and high floc recovery for biodiesel. Energy Convers Manag 149:13–25CrossRefGoogle Scholar
  19. Moheimani NR, Borowitzka MA, Isdepsky A, Fon Sing S (2013) Standard methods for measuring growth of algae and their composition. In: Borowitzka MA, Moheimany NR (eds) Algae for biofuels and energy. Springer, Dordrecht, pp 265–284CrossRefGoogle Scholar
  20. Muniain-Mujika I, Girones R, Tofiño-Quesada G, Calvo M, Lucena F (2002) Depuration dynamics of viruses in shellfish. Int J Food Microbiol 77:125–133CrossRefGoogle Scholar
  21. Pivokonsky M, Safarikova J, Bubakova P, Pivokonska L (2012) Coagulation of peptides and proteins produced by Microcystis aeruginosa : interaction mechanisms and the effect of Fe–peptide/protein complexes formation. Water Res 46:5583–5590CrossRefGoogle Scholar
  22. Pivokonsky M, Safarikova J, Baresova M, Pivokonska L, Kopecka I (2014) A comparison of the character of algal extracellular versus cellular organic matter produced by cyanobacterium, diatom and green alga. Water Res 51:37–46CrossRefGoogle Scholar
  23. Pivokonsky M, Naceradska J, Kopecka I, Baresova M, Jefferson B, Li X, Henderson RK (2016) The impact of algogenic organic matter on water treatment plant operation and water quality: a review. Crit Rev Environ Sci Technol 46:291–335CrossRefGoogle Scholar
  24. Rawat I, Ranjith Kumar R, Mutanda T, Bux F (2013) Biodiesel from microalgae: a critical evaluation from laboratory to large scale production. Appl Energy 103:444–467CrossRefGoogle Scholar
  25. Roselet F, Vandamme D, Roselet M, Muyalert K, Abreau PC (2017) Effects of pH, salinity, biomass concentration, and algal organic matter on flocculant efficiency of synthetic versus natural polymers for harvesting microalgae biomass. Bioenergy Res 10:427–437CrossRefGoogle Scholar
  26. Takaara T, Sano D, Masago Y, Omura T (2010) Surface-retained organic matter of Microcystis aeruginosa inhibiting coagulation with polyaluminum chloride in drinking water treatment. Water Res 44:3781–3786CrossRefGoogle Scholar
  27. Vandamme D, Foubert I, Muylaert K (2013) Flocculation as a low-cost method for harvesting microalgae for bulk biomass production. Trends Biotechnol 31:233–239CrossRefGoogle Scholar
  28. Xiao R, Zheng Y (2016) Overview of microalgal extracellular polymeric substances (EPS) and their applications. Biotechnol Adv 34:1225–1244CrossRefGoogle Scholar
  29. Zar J (2010) Biostatistical analysis, 5th edn. Prentice-Hall/Pearson, Upper Saddle RiverGoogle Scholar

Copyright information

© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Laboratory of Microalgae Production, Institute of OceanographyFederal University of Rio Grande – FURGRio GrandeBrazil

Personalised recommendations