低压汞灯产生臭氧的效率和机理研究(英文)

Efficiency and mechanism of ozone generation from a low-pressure ultraviolet lamp

研究了发射254和185 nm两种波长紫外光的低压汞灯照射气相产生臭氧的效率,主要探讨了反应器的尺寸、振荡挡板、气体压力和流速、温度和湿度对臭氧产生效率的影响。在气体流速一定的情况下,存在一个最佳的反应器尺寸达到最大臭氧产生量,振荡挡板对臭氧产生量影响不大,臭氧投量随着气压和流量的增加而增加,但随着湿度的增加而减小,气体温度对臭氧产生量的影响不大。本研究气相产生臭氧可以通入水相,达到紫外和臭氧联合消毒和氧化,并且,文丘里管对臭氧的传质效果优于气泡分散器,在最优条件下产生的臭氧气体采用文丘里管通入水相后,可以强化紫外光消毒和杀菌的效果。

This paper presents an investigation on the design and improvement of a reactor that uses a low - pressure UV Lamp, which emits two principal wavelengths at 254 and 185 nm, to generate ozone. Several parameters affecting the ozone generation by 185 nm UV, including lamp types, reactor diame- ters, installation of oscillatory baffles, gas pressure and flow rate, temperature, and humidity, were eval- uated. A high -output lamp （20 W） with synthetic quartz glass produced ozone of 10% -30% higher concentrations than a low - output lamp （ 10 W） with natural quartz glass. There was an optimum reactor diameter to yield the highest ozone concentration at a constant gas flow rate. The oscillatory baffles did not considerably enhance ozone generation. Ozone generation increased with increasing gas pressure and flow rate, but decreased with increasing humidity. The effect of gas temperature on ozone generation was less significant. The ozone produced in the gas phase can be transferred into water phase to achieve UV and ozone co - exposure for disinfection and oxidation. The ozone concentrations in deionized water were higher than that in tap water due to the extra ozone demand from tap water. Nevertheless, the ozone con- centrations in both waters are high enough to enhance UV disinfection and oxidation.