| PurposesIn view of the security problems of outdoor water use in the army,especially the difficulty in obtaining clean water and the possible biological pollution of water source during special operations,this paper studies the luminous performance of deep ultraviolet LED and the disinfection effect of drinking water,and makes a small portable design and preliminary trial-manufacture,tests its disinfection efficiency and discusses the influencing factors,thus providing a scientific and effective method of research and development ideas for ensuring the biological safety of outdoor drinking water.Methods1.The literature research on ultraviolet disinfection and the difference between deep ultraviolet LED and traditional ultraviolet mercury lamp.Through literature research on ultraviolet mercury lamp disinfection,the disinfection characteristics,microbial disinfection dosage and disinfection application specifications of ultraviolet mercury lamp were understood.The related research and application progress of deep ultraviolet LED drinking water disinfection were summarized.The performance differences between deep ultraviolet LED with specific luminous wavelength and traditional ultraviolet mercury lamp were compared,which provided guidance for subsequent research.2.According to the germicidal dose characteristics of deep ultraviolet LED,the preliminary device were designed,the development and application were carried out.According to the above literature research,the engineering design software(UG,NX10.0)was used to design a new type of deep ultraviolet LED drinking water disinfection device,including the structural design of ultraviolet reactor,LED lamp bead array arrangement and heat dissipation accessories design,finally,combined with 3D printing technology,a deep ultraviolet LED military kettle cover and an over-flow drinking water disinfection device were manufactured.3.The disinfection effect of the device is verified by experiments.The disinfection experiment of common drinking water pathogens cultured in laboratory was carried out by using deep ultraviolet LED,and the disinfection effect of deep ultraviolet LED was observed.The disinfection effect of bacteria-contaminated water samples in laboratory was observed and the disinfection effect and influencing factors were evaluated by using the preliminarily developed deep ultraviolet LED military kettle cover and the over-flow drinking water disinfection device.According to the national standard method of ultraviolet disinfection of drinking water(GB28235-2020),the disinfection effect of drinking water was verified.4.The luminous intensity and characteristics of deep ultraviolet LED lamp beads are tested and simulated.According to the factory parameters and luminous characteristics of the deep ultraviolet LED lamp beads,the pearlescent intensity distribution of the deep ultraviolet LED lamp used in the experiment is tested by using the ultraviolet LED illuminance meter,and the light field distribution of the deep ultraviolet LED lamp beads is simulated by using matlab software,so as to intuitively understand the luminous characteristics of the deep ultraviolet LED light source and the light intensity distribution in space,analyze the defects of the device and further guide the design.5.Evaluation of ultraviolet radiation dose of deep ultraviolet LED disinfection device.The equivalent ultraviolet irradiation dose provided by disinfection device under certain irradiation time and flow rate was evaluated by using the method of ultraviolet parallel beam meter and equivalent biological verification dose measurement.The relation diagram of kettle irradiation time-ultraviolet dose and flow rate-dose of over-flow drinking water disinfection device were drawn.The use method of the device when reaching effective dose was evaluated,and suggestions for improvement were put forward.ResultsThrough this study,it was confirmed that 280 nm deep ultraviolet LED could quickly and effectively inactivate pathogenic bacteria in drinking water,and a single 5m W deep ultraviolet LED could inactivate E.coli 3log in military kettle within 3min.In the experiment,it was found that there was tailing phenomenon in drinking water disinfection of military kettle with deep ultraviolet LED,that is,a small amount of E.coli could still be detected in water samples after irradiation for 8 min or even longer.The concentration of Escherichia coli can be reduced from 10~5 CFU/100m L to 0 CFU/100m L at a flow rate of 300 m L/min,and 2log inactivation of MS2 phage can be achieved at a flow rate of 60 m L/min,which is equivalent to the equivalent bioassay dose of 40 m J/cm~2.ConclusionThe deep ultraviolet LED military kettle and the over-flow drinking water disinfection device can quickly and effectively disinfect drinking water,and provide a new method for individual soldiers’drinking water safety.Compared with traditional drinking water disinfection methods for individual soldiers,such as adding chlorine preparation and filtering,ultraviolet disinfection has the characteristics of safety,no toxicity,no addition,simple operation and reusability.Moreover,the deep ultraviolet LED drinking water disinfection device for individual soldiers is small in size,portable and easy to use,and has excellent military application prospects.At present,deep ultraviolet LED still has some shortcomings,such as low luminous efficiency and high energy consumption.The wider application depends on improving the light emitting efficiency of deep ultraviolet LED and optimizing the structural design,so as to achieve better disinfection effect and improve energy utilization efficiency. |
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