title: Additive-free harvesting of oleaginous phagotrophic microalga by oil and air flotation.
abstract: A unique oleaginous phagotrophic microalga Ochromonas danica is poised for effective lipid production from waste. Cell harvesting and dewatering are major costs in making algae-based products. In this work an effective additive-free harvesting method was developed, taking advantage of O. danica's comparatively more hydrophobic surface and larger size. The algal cells' partitioning to oil/water interface was evaluated. Recovery by flotation with waste cooking oil was optimized using an L-9 Taguchi orthogonal-array design. Further, additive-free cell collection and concentrating by air flotation was studied for the effects of both physical factors (column dimension, air-stone pore size, sample-to-column volume ratio) and culture properties (pH, culture growth stage, cell concentration, and pure versus impure cultures). The optimized process consistently achieved >90 % recovery in a single stage. 98+ % recovery could be achieved when starting concentrations were >10(8) cells/ml, or potentially using a two- or multi-stage process for diluter cultures.
authors.affiliation: Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH, 44325, USA.
authors.forename: Majid
authors.initials: M
authors.lastname: Hosseini
authors.affiliation: Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH, 44325, USA.|Bridgestone Americas Tire Operations, 10 E. Firestone Blvd., Akron, OH, 44317, USA.
authors.forename: Haley A
authors.initials: HA
authors.lastname: Starvaggi
authors.affiliation: Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH, 44325, USA. ju@uakron.edu.
authors.forename: Lu-Kwang
authors.initials: LK
authors.lastname: Ju
mesh_terms: D018533:Biomass; D005427:Flocculation; D057927:Hydrophobic and Hydrophilic Interactions; D058086:Microalgae / Q000378:metabolism*; D009821:Oils
chemical_list: D009821:Oils
keywords: Algae; Biofuel; Cell hydrophobicity; Flotation; Waste cooking oil