Flocculation properties of several microalgae and a cyanobacterium species during ferric chloride, chitosan and alkaline flocculation.
Flocculation holds great potential as a low-cost harvesting method for microalgae biomass production. Three flocculation methods (ferric chloride, chitosan, and alkaline flocculation) were compared in this study for the harvesting of 9 different freshwater and marine microalgae and one cyanobacterium species. Ferric chloride resulted in a separation efficiency greater than 90% with a concentration factor (CF) higher than 10 for all species. Chitosan flocculation worked generally very well for freshwater microalgae, but not for marine species. Alkaline flocculation was most efficient for harvesting of Nannochloropsis, Chlamydomonas and Chlorella sp. The concentration factor was highly variable between microalgae species. Generally, minimum flocculant dosages were highly variable across species, which shows that flocculation may be a good harvesting method for some species but not for others. This study shows that microalgae and cyanobacteria species should not be selected solely based on their productivity but also on their potential for low-cost separation.
Laboratory for Aquatic Biology, KU Leuven Campus Kulak, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium; Department of Biotechnology, School of Science, Kathmandu University, Dhulikhel, Nepal.
Sanjaya
S
Lama
Laboratory for Aquatic Biology, KU Leuven Campus Kulak, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium.
Koenraad
K
Muylaert
Department of Biotechnology, School of Science, Kathmandu University, Dhulikhel, Nepal.
Tika Bahadur
TB
Karki
KU Leuven Kulak, Research Unit Food & Lipids, Department of Molecular and Microbial Systems Kulak, Etienne Sabbelaan 53, B-8500 Kortrijk, Belgium; Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
Imogen
I
Foubert
bioMASS lab, School of Chemical Engineering, The University of New South Wales, Sydney 2052, Australia.
Rita K
RK
Henderson
Laboratory for Aquatic Biology, KU Leuven Campus Kulak, Etienne Sabbelaan 53, 8500 Kortrijk, Belgium. Electronic address: dries.vandamme@kuleuven.be.
Dries
D
Vandamme
D000468:Alkalies / Q000737:chemistry*; D018533:Biomass; D048271:Chitosan / Q000737:chemistry*; D002712:Chlorides / Q000737:chemistry*; D000458:Cyanobacteria / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D005427:Flocculation; D058086:Microalgae / Q000737:chemistry* / Q000254:growth & development; D013045:Species Specificity
D000468:Alkalies; D002712:Chlorides; D005290:Ferric Compounds; D048271:Chitosan; C024555:ferric chloride
Biofuels; Coagulation; Dewatering; Dose-response; Microalgae; Settling