Electrochemical degradation of cyanobacterial toxin microcystin-LR using Ti/RuO2 electrodes in a continuous tubular reactor

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 electro-oxidation. 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/cm(2). 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.