Studies On Decoloration Of Jujube Polysaccharide By Non-thermal Plasma-photocatalysis-adsorption Integration Technology

According to the principle that dielectric barrier discharge (DBD) cangenerate non-thermal plasma (NTP),three types of NTP decoloration devices weredesigned and made and applied in the study of jujube polysaccharide solutiondecoloration, named “hollow”,“stream-line”and“steam-film”, Meanwhile, in theguide of the theory that free radical can be produced by photocatalysis in thestimulation of the ultraviolet which is generated through dielectric barrierdischarge,the study of jujube polysaccharide solution decoloration was conductedthrough the non-thermal plasma-photocatalysis-adsorption integration technologywhen the activated alumina particles were added into the NTP devices whichloaded the TiO2photocatalyst.The NTP devices was used in the research of jujube polysaccharide solutiondecoloration, and the result indicates that,“stream-film” stype device is betterthan “hollow” and “stream-line” stype devices in the jujube polysaccharidesolution decoloration study.When the applied voltage was24kV and treatment25min, the decoloration rate of jujube polysaccharide solution was42.4%and thesugar loss rate was9.6%.The non-theraml plasma-adsorption technology, formed when the activatedalumina particles was first added into the NTP devices, can increase decoloreffect.In the study of jujube polysaccharide solution decoloration withNTP-adsorption technology and the orthogonal analysis done based on the thesingle-factor tests. According to the results of analysis, the optimal combination ofthe level is that, the NTP devices filled with activated alumina with an averageparticle size of3.01mm, sugar concentration with the density of24.21g/L,30-mindecoloration, and the imposed voltage of18kV, achiveing the decoloration rate as57.0%and sugar loss rate as9.8%.The use of NTP-photocatalysis-adsorption integration technology has obviousadvantages in the application of jujube polysaccharide decolorization.Use of TiO2photocatalyst can improve the decoloration rate of jujube polysaccharide solutionwith NTP-adsorption technolog by15%. The calcination temperature has great impact on the TiO2photocatalyst catalytic action,and then affect the result ofjujube polysaccharide solution decoloration. Experimental results show that: Whenthe calcination temperature is500℃and and the imposed voltage of24kV,boththe TiO2photocatalyst and jujube polysaccharide solution decoloration have thebest effects with the decolor rate as much as71.0%and the sugar loss rate as16.5%.Relevant research show that decolorization of jujube polysaccharide withactivated carbon,the decoloration rate was31.2%and sugar loss68.4%. H2O2wasapplied in the system of NTP-photocatalysis-adsorption integration technology,canimprove jujube polysaccharide solution decoloration result, the decoloration ratewas89.7%, and the sugar loss rate was only20.6%.It was not only a higher rate ofdecolorization, but also good to avoid the loss of polysaccharide jujube.NTP-photocatalysis-adsorption integration technology has the followingadvantages:low energy consumption,simple operation,no secondary pollution andso on.Therefore it will be of significance in generalizing and the application ofNTP-photocatalysis-adsorption integration technology in the field of bleaching.