A multi-wire-to-cylindrical type packed-bed plasma reactor for the inactivation of M. aeruginosa

Eutrophication in drinking water supplies brings about serious impact on the drinking water safety. In this study, a new multi-wire-to-cylindrical type packed-bed plasma reactor has been proposed and experimentally investigated its ability to control excessive growth of Microcystis aeruginosa (M. aeruginosa). Experimental results show the removal efficiency of M. aeruginosa and the inactivation constant were increased with the increased electrode number and air flow rate. More than 93% of optical density was removed at an air flow rate of 0.75 m3/h with treatment for 40 min at the end of the fifth day and the inactivation constant 16.20 was obtained in the multi-wire-to-cylindrical type packed-bed plasma reactor with 3 mm diameter 6-wire high-voltage electrodes; the difference in the electrode material on the removal efficiency of M. aeruginosa was unobvious, but the effects of pulse repetitive rate and applied peak pulse voltage on the inactivation of M. aeruginosa were significant. The changes in the visible spectra of M. aeruginosa solution demonstrated that photosynthetic pigments, such as chlorophyll-a, phycocyanins, carotenoids have been damaged, indicating the inhibitive behaviors of discharge on the algal growth. These results implicate that M. aeruginosa cells were inactivated by a multi-wire-to-cylindrical type packed-bed plasma reactor, demonstrating the considerable potential of such an alternative process for efficient water purification.