Microalgae Recovery from Water for Biofuel Production Using CO2-Switchable Crystalline Nanocellulose.

Environ Sci Technol. 2016 Jul 19;50(14):7896-903. doi: 10.1021/acs.est.6b00732. Epub 2016 Jun 29.

Author

Ge S1, Champagne P1,2, Wang H2, Jessop PG3, Cunningham MF2.

Author information

1

Department of Civil Engineering, Queen's University , 58 University Avenue, Kingston, Ontario K7L 3N6, Canada.

2

Department of Chemical Engineering, Queen's University , 19 Division Street, Kingston, Ontario K7L 3N6, Canada.

3

Department of Chemistry, Queen's University , 90 Bader Lane, Kingston, Ontario K7L 3N6, Canada.

Abstract

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.

PMID:

 

27314988

 

DOI:

 

10.1021/acs.est.6b00732

For further details logon website :
https://www.ncbi.nlm.nih.gov/pubmed/27314988