Study On Removal Of Indoor Formaldehyde By Photocatalysis Combined With Plasma

Indoor formaldehyde gas pollution caused by interior decoration materials is slowly filling the indoor environment of our lives.Formaldehyde has many adverse effects on human health,including damage to respiratory system,liver function and immune function,as well as carcinogenic and teratogenic effects.Photocatalytic technology and plasma technology,as effective methods for purifying indoor organic gas pollutants,are widely used in the formaldehyde pollutant degradation process.The combination of photocatalytic technology and plasma technology can integrate the advantages of both,reduce the disadvantages of the technology,and has the advantages of improving the reaction rate,complete purification,short reaction time,reducing power consumption and by-products.In this thesis,photocatalysis and plasma degradation of formaldehyde is the research topic.First,we designed and built gas pollutants lab,provided the experimental site for degradation experiment.Second,through literature review,preparation of experiment materials,design of experimental scheme,determination of the experimental steps,we studied the photocatalytic synergy plasma effect on the degradation of formaldehyde,and made the comparative analysis on the degradation of formaldehyde by single photocatalysis and single plasma.Third,in the formaldehyde photocatalytic synergy plasma experiment,we choose the initial concentration,relative humidity and light catalyst load as three controllable factors to design the orthogonal test,trend analysis and variance analysis was carried out on the experimental data,then we determined the best proportion of the experiment condition.Under this condition,we determined the optimal purification effect of target condition of photocatalytic co-plasma.The main conclusions of this thesis are as follows:（1）Single photocatalytic degradation process mainly concentrated in the first 60 minutes,a single from the initial concentration of the formaldehyde photocatalytic has promoting effect,the higher the initial concentration,the higher the formaldehyde purification rate,the higher the amount of degradation and the average degradation rate,and the relative humidity can hinder single photocatalytic degradation.when the load is greater than 3.0mg/cm2,increasing the photocatalyst load has little effect on the reaction system.（2）The single plasma degradation process is mainly concentrated in the first 40 min,the higher the initial concentration of formaldehyde,the lower the formaldehyde purification rate,and the relative humidity has an obstruction effect on the single plasma degradation.（3）Compared to a single light catalysis and single plasma degradation experiment,the plasma basically not continue to react after 40 min,photocatalytic reaction can be maintained for 100 min,even longer,in a short period of time,plasma can degrade more formaldehyde gas,and has better degradation effect.Photocatalysis has more obvious advantages in the longterm degradation process of formaldehyde.Relative humidity inhibits both photocatalysis and plasma.（4）The trend chart of influencing factors obtained from the orthogonal experiment of photocatalysis and plasma degradation of formaldehyde shows that the degradation effect of formaldehyde increases with the increase of initial concentration;With the increase of relative humidity,the degradation effect gradually weakened.Under the condition of catalyst loading,the degradation effect increased and then decreased.The significance levels of initial concentration of formaldehyde,relative humidity and photocatalyst load were as follows:initial concentration>Relative humidity>Photocatalyst loading capacity.Under the optimal experimental conditions,the purification rate of formaldehyde reached 68.1%.The research results of this thesis can be used as the research basis for the degradation of formaldehyde by photocatalytic technology and plasma technology,providing reference for the combined technology to degrade pollutants,supporting the exploration of the influence factors of photocatalytic collaborative plasma,and providing guidance for the further improvement and application of combined technology.