Study On Preparation And Activation Of Activated Carbons From Jujube And The Adsorption Performance For Formaldehyde

Activated carbon is a kind of renewable adsorbing material,which has high adsorption capacity and high recovery rate.these characteristics make it widely used in the prevention and control of atmospheric pollution,pharmaceutical industry and solvent regeneration,etc.Until now there is still a lot of researches and preparations of active carbon.Formaldehyde is one kind of dangerous allergic reaction to the original,which is concluded as the chemical cause of high carcinogenic and deformity.At the same time it is one of the subtle strong mutagenic material,and widely exist in our decoration and furniture materials.Biomass has very extensive distribution,whose own tube bundle is also very rich,which is conducive to form rich carbon channel.Thus it can be produce the high performance activated carbon at a lower cost,and its development is worth in-depth study in the future.At present,more and more researchers using the biomass to produce activated carbon.Microwave heating has many heating advantages such as rapidity,efficiency and environmental protection.but the microwave heating is selective,so extra microwave absorbing materials often should be added in.Microwave heating is more uniform and relatively has better product features than conventional heating,so it has greater potential for development.In this paper the preparation of activated carbon is based on common jujube as raw materials,and conventional heating is used to make jujube carbonize in order to get common initial activated carbon.Then it fully mixed with different activator,and generated to activated carbon under microwave heating.First,impregnation ratio of zinc chloride to material,zinc chloride solution concentration,carbonization temperature,carbonization time are choosed as investigation object under the condition of the conventional heating,after which the elements of the initial active methylene blue adsorption and the effect of iodine adsorption capacity arestudied respectively.Then though orthogonal analysis method,the better technological parameter was confirmed as the following: zinc chloride concentration is 60%,solid-liquid ratio is 2:1,dipping time is 90 minutes,carbonization temperature is 600 ? and coking time is 40 minutes.Secondly,use microwave heating to activate them,and explore the influence of different activator,impregnation ratio,irradiation power and irradiation time on methylene blue and iodine adsorption ability of active carbon.The preparation of activated carbon process was optimized by using response surface method,finally the optimal preparation condition was confirmed as the following: sodium hydroxide concentration is 1.5:1,the radiation power is400 w,radiation time is 30 min.Modified activated carbon adsorption of methylene blue was198.97 mg/g,iodine adsorption capacity of 1308.5 mg/g.Eventually,activated carbon adsorption formaldehyde experiment platform is set up to measure gaseous formaldehyde equilibrium adsorption value of different activated carbon,formaldehyde adsorption isotherm model,and establish a formaldehyde adsorption isotherm models to conclude the equilibrium adsorption capacity of sodium hydroxide modified activated carbon,potassium oxalate modified activated carbon and nitric acid modified activated carbon were 13.46,12.33,and 9.03 mg/g.Besides,with the activated carbon particle size decreasing,the formaldehyde adsorption capacity increases.