Contribution of sediments in the removal of microcystin-LR from water

Haihong Song; Elke S Reichwaldt; Anas Ghadouani

doi:10.1016/j.toxicon.2014.02.019

Contribution of sediments in the removal of microcystin-LR from water

Toxicon. 2014 Jun:83:84-90. doi: 10.1016/j.toxicon.2014.02.019. Epub 2014 Mar 13.

Authors

Haihong Song¹, Elke S Reichwaldt², Anas Ghadouani³

Affiliations

¹ Aquatic Ecology and Ecosystem Studies, M015, School of Civil, Environmental and Mining Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia. Electronic address: 20467553@student.uwa.edu.au.
² Aquatic Ecology and Ecosystem Studies, M015, School of Civil, Environmental and Mining Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia. Electronic address: elke.reichwaldt@uwa.edu.au.
³ Aquatic Ecology and Ecosystem Studies, M015, School of Civil, Environmental and Mining Engineering, The University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia. Electronic address: anas.ghadouani@uwa.edu.au.

PMID: 24631598
DOI: 10.1016/j.toxicon.2014.02.019

Abstract

Microcystins are produced by several species of cyanobacteria and can harm aquatic organisms and human beings. Sediments have the potential to contribute to the removal of dissolved microcystins from the water body through either adsorption to sediment particles or biodegradation by the sediment's bacterial community. However, the relative contribution of these two removal processes remains unclear and little is known about the significance of sediment's overall contribution. To study this, changes in the concentration of microcystin-LR (MCLR) in the presence of sediment, sediment with microbial inhibitor, and non-sterile lake water were quantified in a laboratory experiment. Our results show that, in the presence of sediment, MCLR concentration decreased significantly in an exponential way without a lag phase, with an average degradation rate of 9 μg d(-1) in the first 24 h. This indicates that sediment can contribute to the removal of MCLR from the water immediately and effectively. Whilst both, the biodegradation and adsorption ability of the sediment contributed significantly to the removal of MCLR from the water body, biodegradation was shown to be the dominant removal process. Also, the sediment's ability to degrade MCLR from the water was shown to be faster than the biodegradation through the bacterial community in the water. The present study emphasizes the importance of sediments for the removal of microcystins from a water body. This will be especially relevant in shallow systems where the interaction between the water and the sediment is naturally high. Our results are also useful for the application of sediments to remove microcystins at water treatment facilities.

Keywords: Adsorption; Biodegradation; Cyanobacterial toxins; Environmental fate; Microcystins; Sediment.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Biodegradation, Environmental
Cyanobacteria / chemistry
Geologic Sediments*
Marine Toxins / chemistry*
Microcystins / chemistry*
Water Pollutants / chemistry*

Substances

Marine Toxins
Microcystins
Water Pollutants
cyanoginosin LR