Journal of South China University of Technology (Natural Science Edition) ›› 2011, Vol. 39 ›› Issue (6): 100-105.doi: 10.3969/j.issn.1000-565X.2011.06.018

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Inactivation Mechanism of Microcystis aeruginosa by Chlorination and UVC Irradiation

Ou Hua-se1  Gao Nai-yun1  Guo Jian-wei1  Mei Hong2  Li Tian1  Dong Lei1   

  1. 1. College of Environmental Science and Engineering∥State Key Laboratory of Pollution Control and Resources Reuse,Tongji University,Shanghai 200092,China; 2. College of Environmental and Chemical Engineering,Shanghai University,Shanghai 200444,China
  • Received:2010-08-18 Revised:2010-11-19 Online:2011-06-25 Published:2011-05-06
  • Contact: 欧桦瑟(1984-) ，男，博士生，主要从事水处理理论与技术研究． E-mail:ouhuase@ yahoo.com.cn
  • About author:欧桦瑟(1984-) ，男，博士生，主要从事水处理理论与技术研究．
  • Supported by:

    国家科技重大专项项目( 2008ZX07421-002， 2008ZX07421-004) ; 国家“863”计划项目( 2008AA06A412) ; 住房和城乡建设部研究开发项目( 2009-K7-4)

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Abstract:

In this paper,the fluorescent characteristics of intracellular and extracellular dissolved organic matters of Microcystis aeruginosa were investigated by means of the EEM ( Excitation Emission Matrix) fluorescence spectroscopy,and the inactivation mechanism of Microcystis aeruginosa by chlorination and UVC irradiation was analyzed according to the cyanobacterial biochemical indexes such as the contents of total protein,phycocyanin,chlorophylla
and microcystin-LR. The results indicate that ( 1) the characteristic materials associated with Microcystis aeruginosa are mainly protein-like matters corresponding to peaks A and B and humic-like matters corresponding to peaks C and D; ( 2) the inactivation of Microcystis aeruginosa by UVC irradiation is mainly due to the photodegradation and advanced oxidation; ( 3) after a UVC irradiation for 60 min,the intracellular protein-like matters are transformed into extracellular humic-like ones,and few residuals are found after 120min; ( 4) the removals of phycocyanin and microcystin-LR respectively reach 83.55% and 94.70% after 30 min,while the removals of total protein and chlorophyll-a are relatively low; ( 5) the inactivation of Microcystis aeruginosa by chlorination is mainly due to the chemical ablation and degradation of cyanobacteria cells by the permeated HClO; ( 6) after a chlorination for 60 min,both the intracellular and the extracellular protein-like matters decline with significant remain of extracellular humic-like matters; ( 7) the removals of phycocyanin and total protein respectively reach 96. 44% and 60. 36% after 30min,while the removals of microcystin-LR and chlorophyll-a are relatively low; ( 8) the UVC irradiation with medium intensity is effective in the removal of cyanobacteria and the purification of dissolved organic matters; and ( 9) the HClO permeated into cyanobacteria cells is also effective in the removal of cyanobacteria but is ineffective
in the purification of dissolved organic matters.

Key words: cyanobacteria, fluorescence spectrum, ultraviolet irradiation, chlorination, Microcystis aeruginosa