Study On UV Disinfection And Dark Repair Of Drinking Water

A waterworks raw water in guangzhou city as the research object,and simulated the actual water treatment process to build a small water treatment structures,determine to raw water precipitation(PAC)-barrels,-filter box-clarifying tank-uv sterilizer handling process,the various structures noninterference independent.Determine the turbidity,UV intensity,hydraulic retention time of the main factors affecting ultraviolet disinfection,the single factor and multiple factors interact to influence on the effect of ultraviolet disinfection,the influence of size:UV intensity>turbidity>hydraulic retention time.Change the value of turbidity.UV intensity and hydraulic retention time.through the center of combination-statistics and analysis on the response surface method of disinfection effect,establish the regression equation of the three factors affecting prediction model for y=-0.009603+0.72x1-1.47x2-0.21x3-0.27x1x2-0.05x1x3+0.025x2x3+0.52x12+1x22+0.17x32,the response surface model was set up at the same time,using SAS software to find out the disinfection effect of the optimal value.The results showed that when turbidity was 0-1.0NTU and UV intensity>3126.39μW cm-2 and the hydraulic retention time>1200s,UV sterilization was the best.The effects of different turbidity,ultraviolet intensity and hydraulic retention time on the dark resurrection of bacteria were studied.Change the value of turbidity、UV intensity and hydraulic retention time.According to the results,when the turbidity in 0～1.0 NTU,the greater the turbidity,bacteria dark resurrection rate faster,when turbidity>1.0 NTU,turbidity is not obvious effects on bacteria dark resurrection.The hydraulic retention time(or UV intensity)certain circumstances,increase the UV intensity(or hydraulic retention time),bacteria dark raised the longer.High UV doses can inhibit the bacteria dark resurrection,in the case of uv dose must be,the higher the uv intensity,bacteria dark raised the longer,the longer the hydraulic retention time,bacteria dark shorter resurrection time.When the culture time was 2d,the bacteria in the water was basically resurrected,and the turbidity,uv intensity and water retention time had no obvious effect on the dark resurrection of the bacteria.The content of organic matter in water body was analyzed by 3D fluorescence spectrometry(3D-EEM),and the change of organic matter in water body was studied under different ultraviolet intensity and water retention time.The results obtained,ultraviolet disinfection can remove the organic matter in the water,and the removal rate of organic matter is proportional to the uv dose.In the same uv dose,the higher the intensity of uv radiation,the higher the removal rate of organic matter.The influence of water retention time on the nutrient elements in the water was studied.The results showed that uv disinfection can reduce the total nitrogen concentration in water,and the longer the duration of the water,the longer the total nitrogen concentration decreases.The total nitrogen concentration in the water gradually increased with the increase of the cultivation time.Uv disinfection has little influence on total phosphorus and total organic carbon concentration in water bodies,and when the time of cultivation is 2d,the total phosphorus and total organic carbon concentration in the water is only beginning to change,and there is an upward trend.Study on the dominant species of dark resurrection in water.The results showed that the dominant species of dark resurrection included two major categories:Proteobacteria and Firmicutes.From the beginning of Betaproteobacteria,the bacterial community began to be unevenly distributed in the sample.When the UV intensity is low,the content of bacteria in the water will change greatly with the extension of dark reactivation time.Increasing ultraviolet intensity can reduce the fluctuation of strain content in water.