title: A novel method to harvest Chlorella sp. by co-flocculation/air flotation.
abstract: OBJECTIVE
  To develop a more effective dissolved air flotation process for harvesting microalgae biomass, a co-flocculation/air flotation (CAF) system was developed that uses an ejector followed by a helix tube flocculation reactor (HTFR) as a co-flocculation device to harvest Chlorella sp. 64.01.
  
  
  RESULTS
  The optimal size distribution of micro-bubbles and an air release efficiency of 96 % were obtained when the flow ratio of inlet fluid (raw water) to motive fluid (saturated water) of the ejector was 0.14. With a reaction time of 24 s in the HTFR, microalgae cells and micro-bubbles were well flocculated, and these aerated flocs caused a fast rising velocity (96 m/h) and high harvesting efficiency (94 %).
  
  
  CONCLUSIONS
  In a CAF process, micro-bubbles can be encapsulated into microalgae flocs, which makes aerated flocs more stable. CAF is an effective approach to harvesting microalgae.
authors.affiliation: Key Laboratory of Solid Waste Treatment and Resource Recycle Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, Sichuan, China.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China. z.lin@cumt.edu.cn.
authors.forename: Zhe
authors.identifier: http://orcid.org/0000-0001-7450-0508
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Key Laboratory of Solid Waste Treatment and Resource Recycle Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, Sichuan, China.
authors.forename: Daoyong
authors.initials: D
authors.lastname: Tan
authors.affiliation: School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, Sichuan, China.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Liu
authors.affiliation: School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, 221116, Jiangsu, China.
authors.forename: Yali
authors.initials: Y
authors.lastname: Kuang
authors.affiliation: Key Laboratory of Solid Waste Treatment and Resource Recycle Ministry of Education, Southwest University of Science and Technology, Mianyang, 621010, Sichuan, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Li
mesh_terms: D018533:Biomass; D002708:Chlorella / Q000254:growth & development* / Q000378:metabolism*; D005427:Flocculation; D058086:Microalgae / Q000254:growth & development* / Q000378:metabolism*; D008962:Models, Theoretical
keywords: Aerated floc; Chlorella; Ejector; Flotation; Harvesting; Helix tube flocculation reactor; Microalgae