Study On Adsorption Of Formaldehyde On Modified Activited Carbon

We are all threatened by the pollution of indoor air. Formaldehyde is one of the main pollutants in indoor air. The best way to remove formaldehyde is to turn it into carbon dioxide and water. Supported oxidation catalyst is selective, environment-friendly and easy to be recucle. At present titanium dioxide supported on porous materials (activated carbon, zeolite, alumina, etc.) is used for the removal of formaldehyde, but it needs ultraviolet radiation. Yoshika found, in all of metal oxides, manganese dioxide had the best reactivity to formaldehyde at room temperature under the conditions of no light, moreover, some data indicated that some other manganese oxides (MnOx, l≤x≤2) also had good catalytic activity.In order to determine the efficiency of formaldehyde removal and simplify the experimental equipment, the adsorption capacities were compared between gas phase method and liquid phase method. The results showed that the bigger the adsorption capacity from liquid phase method was, the bigger that of gas phase method was, so the preparation conditions of the best efficiency of formaldehyde removal in air could be deduced from the preparation conditions of liquid phase method. Besides, the effects of particle size and solution concentration of formaldehyde on the adsorption capacity were investigated. The results showed that the larger the particle size of sorbent was, the bigger the adsorption capacity was; the higher the formaldehyde concentration was, the bigger the amount adsorbed was. At the same time, the foregoing experimental results all showed the adsorption capacity on manganese dioxide was much bigger than that on activated carbon.The study results of manganese oxide supported on activated carbon used as formaldehyde sorbent showed that with the increase of mass percent concentration of potassium permanganate, the adsorption capacity rose at the begining, then reduced gradually, and lastly almost stabilized. With the increase of heat-treatment temperature, the amount adsorbed firstly rose and then reduced gradually. The maximum adsorption capacity was 5.51mg/g when heat-treatment temperature was 650℃ and mass percent concentration of...