Research On The Microwave Regeneration Mechanism Of Organic Polluted Waste Activated Carbon

Organic wastewater is one of the pollution factors in industry,and using activated carbon to treat the organic wastewater is an effective method and has been widely used,thus there are a large number of organic pollutants:waste activated carbon,and it is very valuable for environmental protection and waste recycling.Spent carbon sample is taken from the zinc sulfite plant.It mainly contains organics.Microwave-ultrasound assisted way is adopted in regeneration process,conventional thermal regeneration way is considered as contrast.The SEM-EDS,GC-MS analysis was used to explore the types and distribution of spent activated carbon pollutants,including microporous structure of carbon,and mechanism of carbon inactivation.The main organic species are ethers,esters,ketones and alcohols,area ratio are15.52%,13.37%,7.9%and 3.1%,respectively,the sulfur-based compounds,nitrogen-based compounds,phenols and benzenes are accounted as 4.52%,0.6%and 2.56%.There are also metal elements including Zn,Mn,Fe,Al,Ga,and Na.Specific surface area,pore volume,pore size of spent carbon are 417cm~2/g,0.22cm~3/g,4.04nm.Dielectric properties of spent carbon,one of the important parameters is dielectric loss,it is positively correlated with microwave absorbing property,there are two temperature ranges:100?-200?and 600?-800?,where dielectric loss reaches the maximum value,indicating how exactly the contaminants volatilize and transform with the effects of microwave energy theory.Combined with microwave assisted way,ultrasound assisted way is used to break the molecular bond energy between organics and carbon molecules.One of its most effects is cavitation effects that deduct the surface tension between solid carbon and liquid adsorbent ethanol,transferring ultrasonic energy and turn to heating energy or other energy to keep breaking the bubbles that quickly produce in spent carbon solution because of pressure difference.In the regeneration process,the yield and adsorption amount of regenerated carbon that regenerate by microwave is better than of conventional method,the calculated adsorption amount are almost 210mg/g,compared with the result of conventional 150mg/g.The BET surface,total volume,pore diameter of microwave-assisted regenerated carbon and conventional regenerated carbon are 923cm~2/g?0.91cm~3/g?3.27nm and724cm~2/g?0.73cm~3/g?3.77nm,both belong to the criterion of mesoporous.