| In recent years,the incidence of allergies has increased year by year,mainly manifested as allergic rhinitis,allergic asthma,dermatitis and bronchitis and other diseases.Numerous studies have shown that the occurrence of allergies is closely related to the inhalation of allergens.Indoor air contains a large amount of allergens.How to purify the allergens and reduce the incidence of allergies has become a research hotspot.Among many technologies for purifying allergens,TiO2 photocatalytic technology is most commonly used.TiO2 photocatalytic technology has the advantages of high purification efficiency,strong corrosion resistance,low cost,not easy decomposition and deterioration,safety and environmental protection,etc.It has a good purification effect on allergens in indoor air,and has broad development prospects.This article combines TiO2 photocatalytic technology with activated carbon filtration technology,and experimentally explores how to improve the efficiency of TiO2 photocatalytic technology in purifying allergens in indoor air,thereby reducing the incidence of allergic diseases.In this paper,natural bacteria in indoor air are used as a representative of allergens.Homemade photocatalytic devices are used to purify natural bacteria in indoor air.The device is cylindrical and consists of an ultraviolet lamp,a fan,a HEPA filter,and a TiO2-ACF photocatalytic material.The air volume can be adjusted according to the needs of the experiment.The TiO2-ACF photocatalytic material is the core of the photocatalytic device.The TiO2 gel is produced by the sol-gel method,and the activated carbon fiber is used as a carrier to support the TiO2.The self-made photocatalytic device was used to purify the natural bacteria in the indoor air.The effects of activated carbon fibers before and after TiO2 loading,types of light,light intensity,TiO2 loading,purification rate,and TiO2 modification treatment on the efficiency of natural bacteria purification,and analyze the service life and regeneration effect of TiO2-ACF photocatalytic material before and after modification.The research results show that when using only activated carbon fiber for purification,there is no obvious purification effect on natural bacteria in the air.Under ultraviolet light,the efficiency of purifying natural bacteria by the photocatalytic device is far greater than that under natural light and dark conditions.The purification efficiency of the photocatalytic device increases with the increase of the light intensity.When the light intensity is less than 15w,the purification efficiency increases significantly with the increase of the light intensity.After the light intensity exceeds 15w,the purification efficiency only slightly increases with the increase of the light intensity Increase.When the loading of TiO2 is less than 15.8%,the purification efficiency increases with the increase of the loading of TiO2.When the loading of TiO2 is higher than 15.8%,the purification efficiency decreases with the increase of the loading of TiO2.When the filtration speed is less than 0.5m/s,the purification efficiency increases as the filtration speed increases.When the filtration speed is more than 0.5m/s,the purification efficiency decreases as the filtration speed increases.During the first 80 minutes of the experiment,the purification efficiency increased significantly with the increase of purification time.During the 80-120 minutes of the experiment,the purification efficiency increased at a slow rate with time.After doping Fe3+ in TiO2 to modify TiO2,the purification efficiency is improved,and the purification efficiency under visible light irradiation is greatly improved.When the Fe3+doping amount is less than 0.3%,the purification efficiency increases as the Fe3+ doping amount increases.When the Fe3+ doping amount is greater than 0.3%,the purification efficiency decreases as the Fe3+doping amount increases.After 4 months of continuous use,the purification efficiency of TiO2-ACF photocatalytic materials decreased significantly.After the photocatalytic material is regenerated,the purification efficiency is improved to a certain extent,and it has a certain in-situ regeneration ability.This article explores the influence of various influencing factors on the efficiency of TiO2-ACF photocatalytic materials in purifying allergens in indoor air through experiments,and seeks ways to improve the purification efficiency. |
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