Research On The Synthesis And Characterization Of Formaldehyde Adsorbents And Their Formaldehyde Adsorption Capability

Formaldehyde is one of the most important pollutant gas in air and it is considered as a cancer-lead material. However, there are a lot of formaldehyde resources in indoor environment including indoor decorating materials and the processing of decorating, which always lead to exceeding the standards of national indoor formaldehyde concentration. Physical adsorption is the way that always leads to repeated pollution.Photocatalysis degrades formaldehyde coming with UV, however, there are some place light can not reach and one day only has 12 hours sunlight supply; electrical degradation cost too much power and the degradation equipments are easy to be out of work; micromolecular absorbents are poisonous and unsuitable for storage. The products between them and formaldehyde are liable. Adsorption using amino-polymers is a promising technology for removing formaldehyde from indoor air because of their self- non-poisonous and high property on reacting with fonnaldehyde. The major goal of this work is to use amino-polymers adsorbing fonnaldehyde so that the indoor formaldehyde concentration can reach the national requirement.In order to achieve the goal, several amino-polymers was synthetized at first in this study and their construction and composites was characterized with FTIR,DSC,NMR and titration. The result has shown that AM055-TETA has the maximum amine value among 16 amino-polymers, which is 4.77 mmol/g.The capacity of adsorption fonnaldehyde in water and air was measured respectively, so that the amino-polymers which has the maximum adsorption formaldehyde capacity can be found and it is necessary to analyze the relationship between the construction of amino-polymers and their adsorption fonnaldehyde capacity.The result has shown that at 25℃,in water, Freundlich model could well describe the adsorption process in which HCPE-TETA has the top adsorption combination capacity. At 25℃, in water, when the original fonnaldehyde concentration is 2.12mg/ml, HCPE-EDA has the maximum adsorption ratio 70.9% at the equilibrium adsorption among amino-HCPE.At 25℃,in water, the process of amino-PVC, amino-AM-EDTA and amino-AM- TETA formaldehyde adsorption-reaction was approximated toⅡclass kinetic reaction model and 4h was the equilibrium time of this type reaction. Their adsorption isotherms belong to typeⅢand Freundlich model could well describe the adsorption process. In amino-PVC, PVC-TETA has the largest reaction velocity and PVC-TETA has the top adsorption combination capacity. In amino-AM-EDTA, AM055-EDTA has the largest reaction velocity and the top adsorption combination capacity. In amino-AM-TETA, AM055-TETA has the largest reaction velocity the top adsorption combination capacity. Among all of them, at 25℃,in water, when the original formaldehyde concentration is 2.12mg/ml, AM055-TETA has the maximum adsorption ratio 75.27% at the equilibrium adsorption.At 25℃,in air,16 amino-polymers formaldehyde adsorption isotherm are belong to type I and Langmuir model could well describe the adsorption process. Among all of them, HCPE-EDA has the highest adsorption capacity 159.48mg/g. At 25℃,in air, when the original formaldehyde concentration is 0.21mg/ml, AM037-EDTA has the highest adsorption ration 76.75%. Among composite adsorbent, at 25℃,in water, HCPE-EDA/H-HPC with mass ratio 4/1 had the highest adsorption ratio 79.18% when the adsorption time is 3h and when the time is 5h, PVC-EDA/PVA with mass ratio 4/1 had the highest adsorption ratio 73.83%.