Inactivation And Biochemical Effects Of Dielectric Barrier Discharge Plasma On Microcystis Aeruginosa And Microcystis Panniformis

The dominant algae species in freshwater lakes in China,including Chaohu Lake,Taihu Lake and Dianchi Lake,are Microcystis aeruginosa.The algae blooms pose a serious threat to the environment,ecosystem and human health,while traditional algae removal methods are difficult to remove safely and economically.The effects of plasma treatment alone and different catalysts(Graphene-gamma Fe₂O₃,H₂O₂ and Fe²⁺)on the degradation of microcystins MC-LR and MC-RR were studied.In addition,based on the above studies,the changes of physiological and biochemical characteristics?including ROS oxidative damage in algae cells,changes in membrane structure and metabolic capacity?and the relative expression of genes related to the main physiological functions of algae cells after plasma treatment were detected in this paper.And the two kinds of algae cells were cultured after plasma treatment by detecting the relative expression of genes related to the main physiological functions of algae cells.The long-term effects of microdose plasma treatment on Microcystis aeruginosa and Microcystis panniformis were studied.?1?The concentration of three long live liquid-phase active substances(H₂O₂,Compared with plasma treatment alone,the concentration of three long-lived active substances in plasma-assisted Graphene-?Fe₂O₃ and Fe²⁺systems decreased to varying degrees,probably because these three active substances were catalyzed to produce other active substances such as·OH,and the concentration of three long-lived liquid-phase active substances in plasma-assisted hydrogen peroxide system increased to varying degrees.?2?The number of Microcystis aeruginosa and Microcystis panniformis decreased rapidly with the treatment.The content of MC-LR and MC-RR in the solution increased first and then decreased with the increase of treatment time.After adding different catalysts(Graphene-?Fe₂O₃,H₂O₂ and Fe²⁺),the inactivation rate of algae cells and the degradation rate of microcystins in solution were improved.?3?The concentration of ROS,NO and MDA in Microcystis aeruginosa and Microcystis panniformis increased significantly after plasma treatment,while the proportion of algae cells with complete membrane structure and metabolic ability decreased rapidly.The relative expression of the representative genes of algae toxin synthesis,community growth,photosynthesis and nutrient uptake in both algae cells decreased to varying degrees,indicating that microdose plasma treatment could affect the nucleic acid transcription and expression in algae cells.?4?The microcystins synthesis ability,cell growth rate,photosynthesis-related pigment synthesis ability and nutrient uptake ability of Microcystis aeruginosa and Microcystis panniformis descended in different degrees after micro-dose plasma treatment,and the relative expression of related representative genes decreased in different degrees,indicating that the expression of related genes in algae cells was inhibited.