title: Microalgae harvesting by flotation using natural saponin and chitosan.
abstract: This study aims to investigate the harvesting of microalgae by dispersed air flotation (DiAF) using natural biosurfactant saponin as the collector and chitosan as the flocculant. Two types of microalgae, Chlorella vulgaris and Scenedesmus obliquus, were used in this study. It was observed that saponin was a good frother, but not an effective collector when used alone for flotation separation of algae. However, with the pre-flocculation of 5 mg/L of chitosan, separation efficiency of >93% microalgae cells was found at 20 mg/L of saponin. Removal efficiency of >54.4% and >73.0% was found for polysaccharide and protein, respectively at 20 mg/L of saponin and chitosan each. Experimental results show that DiAF using saponin and chitosan is effective for separation of microalgae, and algogenic organic matter (AOM). It can potentially be applied in the integrated microalgae-based biorefinery.
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106, Taiwan.
authors.forename: H Agnes
authors.initials: HA
authors.lastname: Kurniawati
authors.affiliation: Department of Chemical Engineering, Widya Mandala Catholic University, Kalijudan 37, Surabaya 60114, Indonesia.
authors.forename: Suryadi
authors.initials: S
authors.lastname: Ismadji
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106, Taiwan. Electronic address: liu1958@mail.ntust.edu.tw.
authors.forename: J C
authors.initials: JC
authors.lastname: Liu
mesh_terms: D020418:Algal Proteins / Q000032:analysis; D056804:Biofuels; D048271:Chitosan / Q000737:chemistry*; D048408:Chlorella vulgaris / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D005427:Flocculation; D058086:Microalgae / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D011134:Polysaccharides / Q000032:analysis; D012503:Saponins / Q000737:chemistry*
chemical_list: D020418:Algal Proteins; D056804:Biofuels; D011134:Polysaccharides; D012503:Saponins; D048271:Chitosan
keywords: Chitosan; Flotation; Harvesting; Microalgae; Saponin