Study On Performance And Influencing Factors Of Chitosan In Purifying Formaldehyde

Along with the improvement of peoples requirements for indoor air quality,the treatment of indoor pollutants has been attracting extensive attention at home and abroad,and the purification method for formaldehyde,the main pollutant in VOCs,has become a research focus.Chitosan,as a kind of natural degradable polymer material,shows a good chemical adsorption property to formaldehyde,and its fiber material is of great application value in the field of air purification.Combined theoretical analysis with experimental research,pure chitosan fiber material and self-made loaded chitosan material were used to explore the purification effect of chitosan on formaldehyde and the influencing factors,in order to optimize the purification performance of formaldehyde,and contrastively analyze the two kinds of chitosan materials.First of all,according to the design of single factor experiment condition,pure chitosan fiber was taken as experimental object,and the effects of the types,pretreatment liquid ph of chitosan materials on the dynamic and static adsorption performance of formaldehyde was studied in the air duct and lab system;in the air duct system,the relative humidity and initial concentration of it on the dynamic adsorption performance of formaldehyde was studied.Subsequently,water-soluble chitosan and polypropylene substrate were used to prepare polypropylene-chitosan(PP-CS)materials,whose purification effect on formaldehyde was studied,and the resistance of the two kinds of filter materials were tested.Finally,through the characterization of the materials,the preparation of PP-CS material was analyzed,and the degree of deacetylation was determined with the element analysis method to analyze the reasons for the difference in purification effect.The results showed that chitosan fibers from red crab and snow crab had different purification effects on formaldehyde,which was caused by different amino contents in the two materials.In the air duct system,the one-time purification efficiency of formaldehyde tended to rise first and then fall with the decrease of ph value of pretreatment solution,and the purification performance was the best when ph=6 approximately.With the increase of the air relative humidity and the initial concentration of formaldehyde,the one-time purification efficiency was increased with quadratic function and power function respectively.For the prepared PP-CS material,chitosan was successfully loaded on the substrate through physical interaction.In the dynamic adsorption experiment,it had a good purification effect on formaldehyde.Under the same resistance condition,it was found that the purification ability of PP-CS was better than that of pure chitosan fiber;at the same level of purification efficiency,the resistance of PP-CS material was relatively less than the former one.