The Study On Regeneration Of Spent Activated Carbon And Adsorption Property Of Regenerated Activated Carbon

The regeneration of spent activated carbon was considered as a promising way,which could not only lower cost,but also protect environment and save resource.There is almost no carbon loss in chemical regeneration,but the regeneration efficiency is lower,while there would gain a higher efficiency in thermal regeneration,but the high regenerated temperature would cause severe carbon loss.In this work,the combination of chemical regeneration and thermal regeneration method was applied for regeneration of spent activated carbon,the effect of pretreatment,temperature of thermal regeneration,parameters of steam activated regeneration on property of regenerated activated carbons was quested and the adsorption property of regenerated activated carbon was studied.The main research contents are as follows:(1)The effect of H2SO4/NaOH pretreatment on physical and chemical property of SPAC.TThe DTG curves of pretreated activated carbon illustrated that H2SO4-treatment just weaken the physical interaction force between activated carbon and adsorbate,NaOH-treatment not only waken physical interaction force,but also change electron cloud density of chemical bond between adsorbent and adsorbate.The FTIR spectrum showed that the concent of O-H and C=C decreased.(2)The effect of regenerated temperature on porosity structure and chemical property of regenerated activated carbon.The iodine value of SPAC?SPAC-H2SO4?SPAC-NaOH increased with regenerated temperature at first,SBET of SPAC-H2SO4 obtained at 600? was maximum,which accounted for 87%of the original value,however,the higher temperature would result in decreasing of the value.The FTIR spectrum of regenerated carbons showed the surface functional groups were pyrolyzed in process of thermal regeneration,especially hydroxyl.(3)The effect of process parameters on iodine value of regenerated carbons in stream activated thermal regeneration of PSAC?SPAC-H2SO4 using orthogonal design.The result of variance analysis illustrated that temperaturexwater volume was the most prominent influence parameter on iodine value of regenerated carbons of SPAC;Temperature was the most prominent influence parameter for SPAC-H2SO4.The maximum of iodine value at optimum level were 1682.94 mg/g?2031.84 mg/g,respectively.(4)The study on adsorption property of regenerated samples.Compared with Langmuir isothermal mode,the relative coefficients of Freundlich model were larger,which were larger than 0.9.The result of adsorption kinetics experiment showed that the pseudo-second-order kinetics fitted well with experiment date compared to the pseudo-first-order kinetics,initial adsorption rate of SPAC-H2SO4-H2O-22 was 20 times as fast as PAC.There,the combonation of acid pretreatment and thermal regeneration could be as a method to improve regeneration efficience.