045

Title:

In-situ self-assembly of Fe3O4@plant polyphenol particles for Chlorella vulgaris harvesting

Discipline: Environmental Engineering

Presenter:

Xiaoyu Wang

Abstract:

Oleaginous microalgae have received significant attention as promising alternative resources of biofuel and magnetic separation shows obvious advantages in microalgae harvesting. In this study, a preparation of Fe3O4@plant polyphenol (PP) submicron particles via in-situ self assembly was investigated to harvest the Chlorella. vulgaris cells. The technique chose ferrocene as the iron source, and PP as the surfactant which is a naturally degradable polymer with a large number of phenolic hydroxyl groups. The cubic inverse spinel structure and nearly spherical shape with average diameter around 145 nm of Fe3O4@PP particles were confirmed from XRD and FESEM patterns. The FTIR, VSM, TG together with XPS analyses verified the full attachment of PP onto Fe3O4 surface and showed a saturated magnetization of 40.0 emu g−1. Compared to the synthesized Fe3O4 without PP, the Fe3O4@PP could overcome the negative effects of extracellular organic matters secreted by microalgae. The harvesting efficiency of microalgae (2.0 ± 0.3×1010 cells/L) from the culture reached 92.4% within 3 min at the dosage of 20.0 g/L. The acidic environment was more beneficial for harvesting and the maximum harvesting efficiency reached 96.6% at pH 3.01. The cells were detached from harvested flocs by adjusting pH values to 11.0 and the recovery efficiency of C. vulgaris could reach 95.6%. The FTIR spectra and Zeta potentials of recycled Fe3O4@PP were almost unchanged, which made the recycled Fe3O4@PP still obtained 87.5% of harvesting efficiency after five cycles.

Author(s):

Xiaoyu Wang, Wenyan Liang, Wen Zhang

Funding Acknowledgements:

This work is financially supported by the Chinese National Natural Science Foundation (51672028) and Fundamental Research Funds for the Central Universities (2015ZCQ-HJ-02 and 2015PY-08).