Microalgae Recovery from Water for Biofuel Production Using CO2-Switchable Crystalline Nanocellulose.
There is a pressing need to develop efficient and sustainable approaches to harvesting microalgae for biofuel production and water treatment. CO2-switchable crystalline nanocellulose (CNC) modified with 1-(3-aminopropyl)imidazole (APIm) is proposed as a reversible coagulant for harvesting microalgae. Compared to native CNC, the positively charged APIm-modified CNC, which dispersed well in carbonated water, showed appreciable electrostatic interaction with negatively charged Chlorella vulgaris upon CO2-treatment. The gelation between the modified CNC, triggered by subsequent air sparging, can also enmesh adjacent microalgae and/or microalgae-modified CNC aggregates, thereby further enhancing harvesting efficiencies. Moreover, the surface charges and dispersion/gelation of APIm-modified CNC could be reversibly adjusted by alternatively sparging CO2/air. This CO2-switchability would make the reusability of redispersed CNC for further harvesting possible. After harvesting, the supernatant following sedimentation can be reused for microalgal cultivation without detrimental effects on cell growth. The use of this approach for harvesting microalgae presents an advantage to other current methods available because all materials involved, including the cellulose, CO2, and air, are natural and biocompatible without adverse effects on the downstream processing for biofuel production.
Department of Civil Engineering, Queen's University , 58 University Avenue, Kingston, Ontario K7L 3N6, Canada.
Shijian
S
Ge
Department of Civil Engineering, Queen's University , 58 University Avenue, Kingston, Ontario K7L 3N6, Canada.|Department of Chemical Engineering, Queen's University , 19 Division Street, Kingston, Ontario K7L 3N6, Canada.
Pascale
P
Champagne
Department of Chemical Engineering, Queen's University , 19 Division Street, Kingston, Ontario K7L 3N6, Canada.
Haidong
H
Wang
Department of Chemistry, Queen's University , 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada.
Philip G
PG
Jessop
Department of Chemical Engineering, Queen's University , 19 Division Street, Kingston, Ontario K7L 3N6, Canada.
Michael F
MF
Cunningham
D056804:Biofuels; D018533:Biomass; D048408:Chlorella vulgaris; D058086:Microalgae; D014867:Water
D056804:Biofuels; D014867:Water