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Mesoporous activated carbon (MeAC) has good adsorption ability for heavy metal ions , its rich pore channels of the liquid phase mass channel , is conducive to the conduct of the liquid phase adsorption . Order to further improve the performance of its adsorption , oxidation , sulfonation and sodium of the surface chemistry MeAC modified , using the static method to study the adsorption properties of the heavy metals lead ions the MeAC before and after modification , and modified MeAC the regeneration research . Boehm titration , nitrogen adsorption-desorption , pore size distribution , infrared spectroscopy , Raman spectroscopy , TG-DTA and XRD method to characterize the various modified MeAC, was oxidized , sulfonated , sodium processing system . Boehm titration results show that the oxidation MeAC (MeAC-O) and sulfonated MeAC (MeAC-O- sulfo ) surface acidic groups the content than MeAC increased 5 -fold and 6 -fold . With the deepening of the degree of oxidation , sulfonation, sodium and other modified , the product of specific surface area , in the porosity and average pore size are reduced. Static adsorption of lead ions , MeAC and modified MeAC of , the modified MeAC lead ion adsorption performance than MeAC high . C 0 less than 140mg · L -1 , the MeAC - O -Na and MeAC - O - sulfonic -Na within 5min to reach equilibrium ; their the equilibrium adsorption capacity of 148.6mg · g -1 and 218.8mg g -1 5 -fold and 8 -fold increase , respectively, than MeAC ; in C 0 70mg · L -1 cases, they maintain high adsorption performance of lead ions in a wide pH range ( 3-5.7 ) , the removal rate of close to 100 %. MeAC adsorption of Pb 2 follow the ion exchange mechanism , as well as the physical adsorption of the carbon surface . The adsorption process chemisorption dominant surface functional groups affects more than the impact of the specific surface area . The regenerative effect of the acid-base two-step regeneration method is much better in dilute nitric acid regeneration method ; higher acid concentration on renewable favorable ; regeneration of the MeAC - O -Na and MeAC - O - sulfonic -Na three times , and still reach 80% renewable and more than 90% .
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