Electrochemical Degradation of Cyanobacterial Toxin Microcystin-LR Using Ti/RuO 2 Electrodes in a Continuous Tubular Reactor

Abstract

Occurrence of cyanobacteria and their potent toxins has imposed a risk to human health and raised concerns in drinking water treatment. In this study, the applicability of electrochemical oxidation on microcystin-LR produced by cyanobacteria was examined using Ti/RuO₂ as anodes. The experiments focused on the variation and elimination of extracellular and intracellular microcystin-LR during the cyanobacterial inactivation by electrooxidation. The effects of applied current density, cell density, as well as electrolyte type on toxin degradation have been studied. The complete elimination of extracellular and intracellular microcystin-LR was achieved and 100% removal for total microcystin-LR was obtained at current density 5 mA/cm². The results showed that when the cell densities decreased or the applied current densities increased, the efficiency of total microcystin-LR removal could be increased. More than 98% removal for total microcystin-LR was also achieved even if the cyanobacteria were inoculated in lake water or drinking water without adding any chemicals. It can be concluded that electro-oxidation of microcystin-LR is quite an efficient method, and can be applied to remove microcystin-LR from waters during the cyanobacterial inactivation.