Study On The Inhibitory Effect Of Different Wavelengths Of UV-Photocatalysis On Dicrateria Under Light And Dark

With the aggravation of eutrophication,the frequent occurrence of red tide events and the fulfillment of the Convention on Ship Ballast Water "Treatment,more and more water treatment areas are facing the problem of algae treatment.For example,in order to avoid the potential risk brought by no-load,ballast water are often required during the oceangoing voyage,which is likely to bring these organisms into off-site waters when being discharged and cause aquatic invasion of local ecosystems,particularly in plankton and pathogens.In this paper,the inhibitory effect of Dicrateria cultivated under the light-dark environment has been studied by the UV-photocatalysis and the effective Ultraviolet radiation area has been determined by analyzing the distribution and attenuation law of Ultraviolet radiation with different bands when given different media.The intensity of ultraviolet radiation decreases significantly with increasing vertical distance.Irradiation intensity is greatly influenced by different media,and the order of air>seawater>high suspended substance seawater>high algae density seawater is from high to low.In this paper,the influential result of the inhibitory effect of Dicrateria cultured under light and dark conditions has been measured by FDA staining,Ultraviolet Spectro-photometry,acetone extraction method and chlorophyll fluorescence.Besides,a further analysis of the inner structure and a comparison of the damaged degree of the algae when being disposed via different methods have been made through Scanning Electron Microscopy(SEM).In conclusion,the combination of UVC and photocatalyst enhances the processing ability,which has a certain amount of destructive effect on the internal structure of algal cells and a noticeable inhibitive effect on the photosynthetic activity.The dual-wave UV-photocatalytic method damages both the outer structure and the inner tissue of algae cells by UV irradiation,and weaken the photosynthetic capacity by motivating the photocatalyst,thus has a further damage on cells activity and inhibitive influence on their reproductive capacity,which making dual-wave UV-photocatalytic better than single-wavelength UV-photocatalytic.