Study On Sampling Detection And Multi Band Ultraviolet Inactivation Technology Of Ship Ballast Water

The ballast water convention has come into force,but there is no common method for ballast water sampling and testing in the national standard.The ballast water treatment technology also has problems such as low treatment efficiency and lack of stable and long-term treatment.Based on this,in order to find a stable and reliable ballast water sampling and detection method,ballast water sampling and detection research was carried out.At the same time,a multi band UV catalytic reactor was designed and simulated to investigate its inactivation effect and mechanism on the microorganisms in ballast water,thus providing a theoretical basis for seeking an efficient ballast water inactivation process.In view of the problems of irrationality and inaccuracy in ballast water sampling and testing,the staining effect of 10～50μm plankton by fluorescence staining and neutral red staining was investigated.It was found that the two staining methods can achieve high accuracy in the staining of 10～50μm plankton,and neutral red staining can be used as a supplement to fluorescence staining.In addition,ballast water sampling method and real ship sampling test were carried out,and the effects of flow velocity,plankton concentration and size on the results were investigated,so as to provide help for the formation of ballast water sampling test standard proposal in China.A UV catalytic reactor was designed and CFD flow field simulation and TracePro light intensity simulation were carried out for the main structure of the reactor with three kinds of UV lamp arrangement.The analysis results showed that the fluid velocity distribution in the effective inactivation area of linear,wavy and square UV catalytic reactors was uniform,which met the design requirements.The average UV radiation dose of square reactor was the largest,which reached the inactivation standard.Based on the design and Simulation of the reactor,a multi band UV photocatalytic biological inactivation system was established.The inactivation effect and mechanism of the system on microorganisms in ballast water were investigated through experiments.The results showed that the combination of UVA,UVC and VUV and the addition of Cu-N-TiO₂ had the best inactivation effect.The content of malondialdehyde（MDA）increased to 4.36μmol/L,the activity of superoxide dismutase（SOD）decreased to 89 U/Mg prot,and the chlorophyll-a of microalgae was degraded to 3.4μg/L.Therefore,a multi band UV photocatalytic Cu,N-doped TiO₂（UVA+UVC+VUV/Cu-N-TiO₂）biological inactivation system could effectively treat microorganisms in ballast water.Finally,the demonstration test of port ballast water reception is completed.