Experimental Studies Of OMS Type UV Sterilizer For The Drinking Water Treatment

With the improvement of human's health awareness,people pay more attention to the safety of drinking water,traditional chlorine disinfection technology would produce by-products and seriously affect human health.UV disinfection technology has gradually been recognized among the field of water treatment with the advantages of great sterilization effect,simple and safe operation as well as no disinfection by-products.An independently developed OMS type ultraviolet sterilizer was applied in this experiment,the inlet and outlet of instrument are set on different sides,A plurality of annular components are installed inside the instrument,which solves the problem of short flow.Component separation design solves the problem of maintenance difficulties;the inner cylinder of the device is covered with a reflective aluminum plate for multiple reflections,which can improve the utilization of ultraviolet light.This experiment mainly studies the sterilization effect of OMS UV sterilizer on drinking water.The water used in the experiment is prepared in the laboratory.The change of HRT is achieved by both adjusting sampling locations and water flow rate.The internal UV intensity is adjusted by the amount of lighted UV lamps.Considering the two variables above,the relationship between UV dose and disinfection effect was studied.By analyzing the experimental data,when the UV dose reached 55.3mJ/cm2,the removal rate of E.coli and bacteria in water came to 100%and 99.9%,respectively.And this dose wasrecognized as the optimal one of E.coli sterilization.Due to the strong resistance of UV light,Bacillus subtilis is more difficult to inactivate compared to E.Coli when the exposure dose was same.When Bacillus subtilis content is higher,Bacillus subtilis should be selected as indicator bacterium.Otherwise,E.Coli should be selected.The effect of three influence factor including turbidity,bioburden and bacterial culture time on UV disinfection are studied in this experiment.The effect of turbidity on the disinfection efficiency of E.coli is related to the UV dose and turbidity.When the turbidity is higher than 3.58 NTU,the turbidity has obvious interference to the disinfection effect.The interference of turbidity changes with the dose of UV radiation.The bioburden had some impact on the removal rate of E.coli and Bacillus subtilis.The removal rate increases with the increase of bioburden.When the bioburden is determined,the inactivation effect of bacteria is defined under a certain range of UV irradiation.Bacillus subtilis under 48 hours cultivation has stronger resistance against UV than bacilli of 24h's cultivation,nevertheless,when the UV irradiation dose is large enough,the inactivation effect of two different stages bacterium had little difference.By fitting analysis,the inactivation of E.coli and Bacillus subtilis under different bioburden loads is studied.By analysis the date of E.Coil inactivation experiment using Chick-Watson equation and Abdennaceu equation,we prove that Chick-Watson equation is only applicable to higher bioburden conditions.Because of the fluctuation of reaction rate,segmentation fitting of Abdennaceu equation can accurately describe the overall effect of bacterial inactivation reaction.Compared with the traditional disinfection device,the sterilization time of OMS type UV disinfection device is shorter,and the disinfection effect is stable.The inactivation process of E.Coli and Bacillus subtilis follow the rules of Abdennaceu equation.When E.Coli content is higher in the water,E.Coli should be selected as indicator bacterium.