活性炭的表面处理对二苯并噻吩催化氧化脱除的影响

将一种木质活性炭经过三种表面处理，即高锰酸钾稀硫酸溶液液相氧化、浓硝酸液相氧化和350℃低温气相氧化处理。实验所选活性炭及相应的表面改性炭使用氮气吸附和Boehm滴定分别进行了结构性质和表面化学表征。研究了所选活性炭和相应的表面改性炭催化过氧化氢氧化脱除二苯并噻吩（DBT）。实验结果表明，活性炭表面化学对二苯并噻吩的氧化脱除影响很大；炭表面化学对DBT吸附脱除的影响不同于对DBT氧化脱除的影响，表面酸性越强越有利于DBT的吸附；表面羰基能加速过氧化氢产生自由基，表面羰基量的增加明显有利于DBT的氧化脱除。活性炭经过热处理后，在二苯并噻吩的氧化脱除中催化活性明显增加，正辛烷溶液中硫的体积质量从0.556g·L-1降到0.009g·L-1。

Effect of surface treatments of activated carbon on the catalytic performance of dibenzothiophene removal

An activated carbon of wood origin was treated by a diluted sulfuric acid solution of KMnO4 (KS), concentrated nitric acid (CN) and thermal oxidation at 350℃ (HT). The structural properties and surface chemistry of the samples with different treatments were characterized by using sorption of nitrogen and Boehm titration, respectively. Oxidative removal of dibenzothiopene (DBT) with hydrogen peroxide catalyzed by the activated carbons was studied. The results showed that the oxidative removal of DBT is dependent on carbon surface properties. The effect of carbon surface properties on the adsorption of DBT is different from its effect on the oxidative removal of DBT; the increase of total acidic groups is favorable for DBT adsorption. The increase of the amount of carbonyl groups is obviously favorable for the oxidative removal of DBT due to a factor: surface carbonyl groups can accelerate hydrogen peroxide to produce hydroxyl radicals. The catalytic performance of activated carbon for the oxidative removal of DBT is improved significantly with the treatment of thermal oxidation at 350℃; the sulfur content in the n octane solution is decreased from 0.556g·L-1 to 0.009g·L-1.