The inhibition of Microcystis aeruginos by electrochemical oxidation using boron-doped diamond electrode

Abstract

Electrooxidation is used to study the inhibition behavior of Microcystis aeruginosa, a dominant algae species during water blooms mainly caused by non-point source pollution. The inhibitory effect of current density, A/V ratio, initial algae concentration, and algae growth phase on the growth of algae by electrochemical oxidation was investigated, respectively. Further, the effect of electrolysis on the photosynthesis of algae cells and the degradation of Microcystin-LR (MC-LR) in solution were also studied. The results showed that the inhibitory effect increased with the increase of current density and A/V ratio. The damage of cell structure and the leakage of intracellular substances were observed when the current density was 17 mA/cm². The intracellular chlorophyll a decreased significantly during the culture period. Only when the A/V ratio was 9.75 m⁻¹, the algal growth could be completely inhibited. The inhibitory effect of algae was decreased with the increase of initial algal concentration, and the inhibitory effect of algae in the log growth phase was better than that in the stationary phase. The degradation efficiency of total MC-LR was 91.7% at 90 min. Some other substances could be degraded simultaneously along with the degradation of MC-LR in electrochemical oxidation.