This project belongs to the technical field of environmental pollutant treatment and detection.  Due to the seriousness of the problem of biological invasion caused by ballast water discharge, in February 2004, the International Maritime Organization (IMO) adopted the International Convention for the Control and Management of Ships 'Ballast Water and Sediments in London. In order to meet the requirements of the Convention, it is necessary to install ballast water treatment devices on ships and develop ballast water testing equipment to achieve ballast water treatment and effect evaluation. As the largest exporter and importer of ballast water, my country's development of complete ballast water treatment and testing technologies with excellent comprehensive performance is of great significance to ensuring the biosecurity of my country's oceans and the sustainability of China's marine economy.  However, implementing the Convention faces two major technical bottlenecks. First, although there are more than 30 ship ballast water treatment methods that have been proposed so far, considering effectiveness, reliability, cost, environment, health and safety, the Marine Environment Protection Committee affiliated to IMO and the Global Ballast Water Management Project Team believe that there is currently no ideal ballast water treatment technology and process. Second, the Convention limits the concentration of living organisms with individual size of 10 - 50um and gt;50um in discharged ballast water. However, existing detection methods, such as widely used fluorescent staining + microscopic examination, have shortcomings such as long detection time, too high detection limit, poor accuracy, large subjective errors among testers, and high testing labor intensity, which cannot achieve rapid and accurate counting of living microorganisms in ballast water.  The research team has carried out long-term research and development on the problems existing in ballast water treatment and testing, and has achieved the following innovative results: (1) A new type of conical orifice plate has been developed, which is used for the first time to generate hydraulic cavitation to inactivate microorganisms in water., found an ideal method for pretreatment of ship ballast water. Compared with conventional orifice plates, the pre-orifice pressure required for hydraulic cavitation of conical orifice plates is reduced by 90%, and the energy consumption is only 6.84% of that of the former. In addition, hydraulic cavitation is a physical inactivation technology that is truly environmentally friendly, and only needs to install orifice plates on the pipeline, which basically does not occupy space;(2) pulsed strong light inactivation technology treats ballast water. It solves the problem that the utilization efficiency of injected light energy needs to be improved in the currently widely used commercial UV treatment technology. Some microorganisms after irradiation are not completely inactivated, and cysts and spores cannot be effectively inactivated. In addition, the UV lamp contains toxic substance mercury, which is scrapped. It may pollute the environment and other issues during disposal, while retaining the advantages of environmentally friendly UV treatment. The innovative built-in pulsed xenon lamps into the reactor not only achieves rapid cooling and efficient inactivation of microorganisms, but also effectively reduces the energy consumption and floor space of the treatment device.  (3) Composite fluorescent staining + flow cytometry quickly and accurately detect ballast water. Based on the fact that the characteristic fluorescence intensity and wavelength generated by the combination of fluorescent probes and different active microorganisms will be significantly different, rapid and accurate counting of living microorganisms in ship ballast water can be achieved. The entire detection time is lt;30 minutes, and the detection accuracy is lt;10%, which is much higher than the currently most widely used fluorescent staining + microscopy method. Moreover, this method can automatically detect batches and simultaneously realize the counting of living organisms in the range of 10 to 50um and gt;50um.  A total of 5 invention patents and utility model patents have been applied for the project, and 4 have been authorized. After scientific and technological novelty search, the overall results of the project have reached the international advanced level. Comprehensive technology has been successfully applied in the fields of ship ballast water treatment and drinking water disinfection, with an added output value of 33.12 million yuan, an added profit of 16.32 million yuan, and an added tax revenue of 5.769 million yuan. In addition, the results of this project have enhanced my country's ability to implement the ballast water convention and provided strong technical support for the daily law enforcement of regulatory authorities.