Harvesting microalgae by centrifugation and filtration is very costly, affecting technical and economical feasibility of downstream processing of algal biomas to bioproducts. Flocculation is a potential technique for recovery of algae biomass. Particularly, flocculation using magnetic nanoparticles offers high separation efficiency due to their high surface area and magnetic properties. I | Cite this paper Vietnam J. Chem. 2023 61 S3 116-125 Research Article DOI Recovery of Chlorella biomass using Fe3O4 and Fe3O4@SiO2 magnetic nanoparticles isotherm and thermodynamic characteristics of adsorption Do Thi Cam Van1 Lam Van Toan2 Nguyen Thi Phuong Dung2 3 Tran Dang Thuan4 Dinh Thi Cuc4 Dang Thi Mai4 Pham Thi Mai Huong5 Pham Thi Thanh Yen5 1 HaUI Institute of Technology Hanoi University of Industry HaUI 298 Cau Dien Bac Tu Liem Hanoi 11900 Viet Nam 2 Graduate University of Science and Technology Vietnam Academy of Science and Technology VAST 18 Hoang Quoc Viet Cau Giay Hanoi 10000 Viet Nam 3 Department of Applied Science University of Transport Technology 54 Trieu Khuc Thanh Xuan Hanoi Viet Nam 4 Institute of Chemistry Vietnam Academy of Science and Technology VAST 18 Hoang Quoc Viet Cau Giay Hanoi 10000 Viet Nam 5 Faculty of Chemical Technology Hanoi University of Industry HaUI 298 Cau Dien Bac Tu Liem Hanoi 11900 Viet Nam Submitted February 19 2023 Revised May 2 2023 Accepted July 21 2023 Abstract Harvesting microalgae by centrifugation and filtration is very costly affecting technical and economical feasibility of downstream processing of algal biomas to bioproducts. Flocculation is a potential technique for recovery of algae biomass. Particularly flocculation using magnetic nanoparticles offers high separation efficiency due to their high surface area and magnetic properties. In this work the synthesized magnetic nanoparticles including Fe 3O4 and Fe3O4@SiO2 were used to harvest C. sorokiniana TH01 from aqueous suspension. The effects of pH adsorbent dosage algal biomass concentration temperature and reaction time on harvesting performance were investigated. It was revealed that the optimal C. sorokiniana TH01 harvesting conditions for Fe3O4 were pH of 5 adsorbent dosage of g L biomass concentration of g L temperature 25oC and reaction time 20-30 min. For Fe3O4@SiO2 the optimal conditions were pH of 7 adsorbent dosage
