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Harvesting of Chlorella vulgaris using Fe3O4 coated with modified plant polyphenol

Author:
Zhao, Yuan, Wang, Xiaoyu, Jiang, Xiaoxue, Fan, Qianlong, Li, Xue, Jiao, Liyang, Liang, Wenyan
Source:
Environmental science and pollution research international 2018 v.25 no.26 pp. 26246-26258
ISSN:
0944-1344
Subject:
Chlorella vulgaris, X-ray photoelectron spectroscopy, chemical bonding, harvesting, iron oxides, magnetic separation, neutralization, pH, polyphenols, thermogravimetry, ultrasonic treatment, zeta potential
Abstract:
The Chlorella vulgaris harvesting was explored by magnetic separation using Fe₃O₄ particles coated with the plant polyphenol chemically modified by a Mannich reaction followed by quaternization (Fe₃O₄@Q-PP). The –N(R)₄⁺ and Cl–N⁺–C perssad of the Q-PP were linked to the Fe₃O₄ particles by N–O bonds, as suggested by the X-ray photoelectron spectroscopy spectra. The thermogravimetric analysis displayed the mass percentage of the Q-PP coated on the Fe₃O₄ surface was close to ~ 5%. Compared with the naked Fe₃O₄ particles, zeta potentials of the Fe₃O₄@Q-PP particles were improved from the range of − 17.5~− 25.6 mV to 1.9~36.3 mV at pH 2.1~13.1. A 70.2 G coercive force was obtained for the Fe₃O₄@Q-PP composite, which demonstrated its ferromagnetic behavior. The use of Fe₃O₄@Q-PP resulted in a harvesting efficiency of 90.9% of C. vulgaris cells (3.06 g/L). The Fe₃O₄ particles could be detached from the cell flocs by ultrasonication leading to a recovery efficiency of 96.1% after 10 cycles. The recovered Fe₃O₄ could be re-coated with Q-PP and led to a harvesting efficiency of 80.2% after 10 cycles. The magnetic separation using Fe₃O₄@Q-PP included charge neutralization followed by bridging and then colloid entrapment.
Agid:
6116911