Chitosan as coagulant on cyanobacteria in lake restoration management may cause rapid cell lysis

WATER RESEARCH

卷:118

Article

Mucci, Maira¹  Noyma, Natalia Pessoa³  de Magalhaes, Leonardo³  Miranda, Marcela³  van Oosterhout, Frank¹  Guedes, Iame Alves⁴  Huszar, Vera L. M.⁵  Marinho, Marcelo Manzi³  Lurling, Miguel^1,2 

[1] Wageningen Univ, Dept Environm Sci, Aquat Ecol & Water Qual Management Grp, POB 47, NL-6700 AA Wageningen, Netherlands

[2] Netherlands Inst Ecol NIOO KNAW, Dept Aquat Ecol, POB 50, NL-6700 AB Wageningen, Netherlands

[3] Univ Estado Rio De Janeiro, Dept Plant Biol, Lab Ecol & Physiol Phytoplankton, Rua Sao Francisco Xavier 524 PHLC Sala 511a, BR-20550900 Rio De Janeiro, Brazil

[4] Univ Fed Rio de Janeiro, Carlos Chagas Filho Biophys Inst, BR-21949902 Rio De Janeiro, Brazil

[5] Univ Fed Rio de Janeiro, Museu Nacl, BR-20940040 Rio De Janeiro, Brazil

关键词: Cell lysis;    Cell viability;    Cyanobacterial blooms;    Eutrophication;    Lake restoration;    Photosystem II efficiency;   

DOI  :  10.1016/j.watres.2017.04.020

来源: Elsevier

【 摘 要 】

Combining coagulant and ballast to remove cyanobacteria from the water column is a promising restoration technique to mitigate cyanobacterial nuisance in surface waters. The organic, biodegradable polymer chitosan has been promoted as a coagulant and is viewed as non-toxic. In this study, we show that chitosan may rapidly compromise membrane integrity and kill certain cyanobacteria leading to release of cell contents in the water. A strain of Cylindrospermopsis raciborskii and one strain of Planktothrix agardhii were most sensitive. A 1.3 h exposure to a low dose of 0.5 mg l(-1) chitosan already almost completely killed these cultures resulting in release of cell contents. After 24 h, reductions in PSII efficiencies of all cyanobacteria tested were observed. EC50 values varied from around 0.5 mg l(-1) chitosan for the two sensitive strains, via about 5 mg l(-1) chitosan for an Aphanizomenon flos-aquae strain, a toxic P. agardhii strain and two Anabaena cylindrica cultures, to more than 8 mg l(-1) chitosan for a Microcystis aeruginosa strain and another A. flos-aquae strain. Differences in sensitivity to chitosan might be related to polymeric substances that surround cyanobacteria. Rapid lysis of toxic strains is likely and when chitosan flocking and sinking of cyanobacteria is considered in lake restoration, flocculation efficacy studies should be complemented with investigation on the effects of chitosan on the cyanobacteria assemblage being targeted. (C) 2017 The Authors. Published by Elsevier Ltd.

【 授权许可】

Free