Title: Flocculation properties of bioflocculant MBF-7 produced by Penicillium purpurogenum in kaolin suspension

Authors: Yongyou Hu, Xiaomin Yan, Wen Chen, Xiaowu Huang

Addresses: College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510640, PR China. ' College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510640, PR China. ' College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510640, PR China. ' College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510640, PR China

Abstract: The properties and modes of flocculation for kaolin suspension with bioflocculant MBF-7 produced by Penicillium purpurogenum, were investigated. The results showed that the optimum pH and dosage for flocculation was above 8 and more than 40 mg L−1, respectively. Flocculating activity of MBF-7 was increased in the presence of Mg2+, Ca2+, Al3+, or Fe3+, especially in the presence of Ca2+, while monovalent Na+ and K+ had little enhancement. According to the zeta potential, FTIR and electrovalent bond tests, the mechanism of flocculation is suggested that coordination electrovalent bond is formed between Ca2+ and MBF-7, and then through coordination bridging between Ca2+ and kaolin, thus three-dimensional reticular flocs are formed via long chains of MBF-7.

Keywords: Penicillium purpurogenum; bioflocculant; polysaccharides; flocculation mechanism; electrovalent bond; kaolin suspension.

DOI: 10.1504/IJEP.2009.025119

International Journal of Environment and Pollution, 2009 Vol.37 No.2/3, pp.166 - 176

Published online: 13 May 2009 *

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