title: Carbon dioxide pressure-induced coagulation of microalgae.
abstract: The move to a low-carbon economy has generated renewed interest in microalgae for the production of biofuels with the potential mutual benefit of wastewater treatment. However, harvesting has been identified as a limiting factor to the economic viability of this process. This paper explores the harvesting of microalgae using high-pressure gas without the addition of coagulants. Coagulation of microalgae under high-pressure gas was found to be an efficient method to separate algae from suspension. The critical coagulation pressures (CCPs) for H(2) and CO(2) were determined to be 6.1 and 6.2 MPa, respectively. The CO(2)-induced decrease in solution pH positively influenced coagulation rates, without appearing to affect the CCP. This approach could be beneficial for the economic removal of microalgae from solution for the production of both biofuels and biomedical compounds without the addition of non-environmentally friendly chemicals.
authors.affiliation: Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6 Department of Civil Engineering, Queen's University, Kingston, Ontario, Canada K7L 3N6.
authors.forename: Roland
authors.initials: R
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Queen's University, Kingston, Ontario, Canada K7L 3N6 jessop@queensu.ca.
authors.forename: Philip G
authors.initials: PG
authors.lastname: Jessop
authors.affiliation: Department of Civil Engineering, Queen's University, Kingston, Ontario, Canada K7L 3N6 pascale.champagne@queensu.ca.
authors.forename: Pascale
authors.initials: P
authors.lastname: Champagne
mesh_terms: D056804:Biofuels; D018533:Biomass; D002245:Carbon Dioxide / Q000737:chemistry*; D048408:Chlorella vulgaris; D005740:Gases; D006859:Hydrogen / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D058086:Microalgae / Q000502:physiology*; D011312:Pressure; D013056:Spectrophotometry, Ultraviolet
chemical_list: D056804:Biofuels; D005740:Gases; D002245:Carbon Dioxide; D006859:Hydrogen
keywords: biomass; carbon dioxide; coagulation; compressed gas; critical coagulation pressure; microalgae