Exploring the dynamics of reactive oxygen species from CaviPlasma and their disinfection and degradation potential — the case of cyanobacteria and cyanotoxins

We investigated the production of highly reactive oxygen species (ROS) in solutions undergoing treatment using CaviPlasma (CP) technology. This technology combines plasma discharge with hydrodynamic cavitation. This study focused on factors such as pH, conductivity, presence of salts and organic matter affecting ROS formation and their stability in solutions. Depending on the used matrix, CP produces 450-580 µg L^-1 s^-1 of hydrogen peroxide and 1.9 µg L^-1 s^-1 of hydroxyl radicals dissolved in liquid. Using cyanobacteria and cyanotoxins as example, we proved that CP technology is a highly efficient method for destroying microorganisms and persistent toxins. The biocidal effect of the CP treatment was confirmed on two species of cyanobacteria, Synechococcus elongatus and Merismopedia minutissima. The effectiveness of the technology in degrading microcystins was also demonstrated. The potential of this technology is based on its high energy efficiency, G(H₂O₂) ≈ 10 g kWh^-1 and G(O₃) ≈ 0.03 g kWh^-1 (in deionised water), realistic applicability with throughput rates (> 1 m³ h^-1), and comparatively easy scalability system.