Study On Photocatalytic Purification Of Odor Pollutants From Domestic Waste

Odor pollution has become a worldwide concern of all countries around the world,Odor pollution is considered to be one of the seven major environmental hazards in the world.Garbage will produce large amounts of odor pollutants in the collection,transport and accumulation process,garbage odor pollutants not only cause serious impact on the atmospheric environment,and will cause a certain degree of impact and damage to human health,therefore the purification of garbage odor pollutants has become a hot research direction of development.Photocatalytic technology can effectively purify garbage odor pollutants,but the photocatalytic technology there is the problem of efficiency is not high,the catalyst is easy to inactivation and short service life of catalyst purification,so it needs further research and improvement.In this paper,photocatalysis and photocatalytic ozonation cleaning garbage odor pollutants respectively,the effects of TiO₂ modification,residence time,initial concentration of pollutants,relative humidity and the amount of ozone dosage on the purification efficiency of the foul odor pollutants were studied.The optimum operating parameters of the technology of photocatalytic purification of the foul odor pollutants from domestic waste are obtained through experiments and analysis.This paper adopts porous metal net as a photocatalyst carrier,was prepared by Sol-gel supported photocatalyst TiO₂,load layer is 3,the method of light catalyst by Fe³⁺doping and calcination modification.The kinetic equation of photocatalytic reaction was simplified,and the kinetic model of photocatalytic reaction was obtained for practical engineering,and the photocatalytic reactor was designed and fabricated according to the model.Test results show that,the photocatalytic activity of TiO₂ was significantly improved after modification,and the purification efficiency of 8 kinds of domestic waste odor pollutants was significantly improved,and the lifting range was more than 10%.The garbage odor pollutants purification efficiency with residence time increased,but the residence time is increased to a certain extent,the purification efficiency of the increase is no longer obvious,this study suggests that the optimal residence time is 3 to 4 seconds.The purification efficiency of polluted odors decreased with the increase of initial concentration,and decreased rapidly,so the photocatalytic oxidation technology is not suitable for the purification of high concentration waste odor pollutants.The relative humidity in the studied range?20%⁷5%?,odor pollutants purification efficiency with the increase of relative humidity,showing a decrease after the first increase in the phenomenon,the photocatalytic reaction in the process of the optimum relative humidity is 30%.In the photocatalytic reaction,the photocatalytic reaction with ozone has been added to produce a synergistic effect,and the purification efficiency of the pollutant has been greatly improved.With hydrogen sulfide as an example,the initial concentration of 0.6mg/m³,the relative humidity is 30%,the residence time is 2.88s,the photocatalytic reaction of the purification efficiency was 62.34%,the purification efficiency of photocatalytic and ozone oxidation reaction is77.65%.In the process of photo catalytic ozonation for the purification of the foul odor of municipal solid waste,the best ozone concentration in the 40mg/m³,the most suitable residence time is still between 3⁴ seconds,but the initial concentration of pollutant and relative humidity have no obvious effect on the purification efficiency,so photocatalytic ozonation technology is suitable for the treatment of high pollutant concentration and relative humidity.Combined process for the composition of ozone oxidation in the photocatalytic reaction,it is suitable for the purification of the foul odor pollutants,and has good application value and broad prospects for development.