Study On Regeneration And Mechanism Of Formaldehyde Activated Carbon Modified With Copper And Iron By Using Microwave Irradiation

With the development of economy,living standard is improving and decoration is more luxurious.However,indoor air health problem can not be ignored.The furniture and paint needed for decoration are the main sources of indoor formaldehyde.And the formaldehyde has the characteristics of long release cycle and strong toxicity,which makes it difficult to remove the formaldehyde at a time.Although formaldehyde is common,its harm can not be ignored.Formaldehyde is not only irritating,but also can cause gene mutation,cancer,leukemia and other diseases.Control of formaldehyde indoor becomes a difficult problem which plagued the people.At present,activated carbon is commonly used to adsorb indoor formaldehyde.But if you want to remove formaldehyde completely,not only a large amount of activated carbon is needed,but also new activated carbon needs to be changed from time to time.When activated carbon is used,it will not only reduce the utilization rate of carbon resources,but also cause the release of adsorbents and pollute the environment.If the activated carbon after adsorbing formaldehyde is not removed in time,the formaldehyde adsorbed under certain conditions will be released into the indoor air,which is counterproductive.Therefore,the collection and regeneration of wasted activated carbon plays an important role in the development of circular economy and environmental health.On the basis of biomass activated carbon,activated carbon is modified before the stage of adsorption.Copper and iron oxide loaded on activated carbon is used as catalyst to improve the regeneration effect of activated carbon.After loading,the activated carbon was scanned under electron microscope to observe the load of copper iron oxide.After modified activated carbons were adsorbed to saturation,they were regenerated by conventional heating and microwave irradiation respectively.The changes of adsorption capacity under different experimental conditions were explored,and the best regeneration conditions were determined.In the conventional heating regeneration experiment,the optimum regeneration condition is :size 40~80 mesh,carrier flow 35 ml/min,regenerative temperature 270?,regenerative time 35 min.In the microwave regeneration experiment,the best regeneration conditions obtained by orthogonal experiment were: carrier flow 25ml/min,radiation power 450 W,regeneration time 8min,moisture content 6g.The adsorption value of original,modified,regenerated by two methods AC are 4.87 mg/g,5.04 mg/g,5.54 mg/g and 5.80 mg/g respectively.Finally,the activated carbon was adsorption and regenerated under the optimal regeneration condition.Results shows that after two cycles of regeneration,the adsorption values of two kinds of regenerated activated carbons were all higher than those of modified activated carbons,and then began to decrease.But after nine times of regeneration,the regeneration rate of conventional heating and microwave regeneration is still higher than 74% and 85%.It shows that the two regeneration methods are all feasible,and the microwave regeneration effect is better than the conventional heating regeneration.After measuring the regenerated activated carbon's mass loss rate and the number of functional groups,it was found that the quality and the number of functional groups in the microwave regeneration were all lower than that of the conventional heating regeneration.It shows that the adsorption effect of microwave regeneration is better.