Inhibition of Alkaline Flocculation by Algal Organic Matter for Chlorella vulgaris

Journal Article · Fri Jan 01 00:00:00 EST 2016 · Water Research

DOI:https://doi.org/10.1016/j.watres.2015.10.032· OSTI ID:1229546

Vandamme, Dries ^[1]; Beuckels, Annelies ^[1]; Vadelius, Eric ^[2]; Depraetere, Orily ^[1]; Noppe, Wim ^[3]; Dutta, Abhishek ^[4]; Foubert, Imogen ^[5]; Laurens, Lieve ^[2]; Muylaert, Koenraad ^[1]

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1. KU Leuven Kulak, Kortrijk (Belgium)
2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
3. IRF Life Siences, Kortrijk (Belgium)
4. KU Leuven, Leuven (Belgium)
5. KU Leuven Kulak, Kortrijk (Belgium); Leuven Food Science and Nutrition Research Centre (LFoRCe), Heverlee (Belgium)

Alkaline flocculation is a promising strategy for the concentration of microalgae for bulk biomass production. However, previous studies have shown that biological changes during the cultivation negatively affect flocculation efficiency. The influence of changes in cell properties and in the quality and composition of algal organic matter (AOM) were studied using Chlorella vulgaris as a model species. In batch cultivation, flocculation was increasingly inhibited over time and mainly influenced by changes in medium composition, rather than biological changes at the cell surface. Total carbohydrate content of the organic matter fraction sized bigger than 3 kDa increased over time and this fraction was shown to be mainly responsible for the inhibition of alkaline flocculation. The monosaccharide identification of this fraction mainly showed the presence of neutral and anionic monosaccharides. An addition of 30–50 mg L^-1 alginic acid, as a model for anionic carbohydrate polymers containing uronic acids, resulted in a complete inhibition of flocculation. Furthermore, these results suggest that inhibition of alkaline flocculation was caused by interaction of anionic polysaccharides leading to an increased flocculant demand over time.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Bioenergy Technologies Office
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1229546
• Report Number(s): NREL/JA-5100-65510
• Journal Information: Water Research, Vol. 88; Related Information: Water Research; ISSN 0043-1354
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
59 BASIC BIOLOGICAL SCIENCES
Extracellular polymeric substances
Dissolved organic matter
Coagulation
Harvesting
Microalgae
Biofuels