对比考察了污泥基活性炭(SCAC)与3种商品活性炭表面官能团的种类、含量及其催化臭氧氧化去除对氯苯甲酸(p-CBA)效能的差异.同时采用(NH4)2S2O8和NaOH分别对SCAC表面进行酸、碱改性处理,探讨SCAC表面官能团对其催化臭氧氧化活性的影响.结果表明,SCAC表面酸性和碱性官能团含量均高于3种商品活性炭;SCAC和商品炭的加入对臭氧氧化去除p-CBA的效果均起到了促进作用,其中SCAC催化臭氧氧化效果最为明显.反应1.0 min时,p-CBA的去除率由单独臭氧氧化时的26.1%提高到60.2%.经(NH4)2S2O8和NaOH处理后,两种改性SCAC对p-CBA的催化氧化去除效果差异明显,NaOH改性后的SCAC表面碱性官能团丰富,其催化臭氧氧化去除p-CBA的效果得到加强,而经过(NH4)2S2O8改性的SCAC催化效果则有所下降.活性炭催化臭氧氧化反应Rct值([·OH]/[O3])计算结果进一步证明,SCAC表面的碱性官能团是其催化臭氧反应的主要活性位点,可以促进臭氧分子向·OH的转化.
This study investigated the differences of functional groups and contents among sludgecorncob activated carbon( SCAC) and three commercial activated carbons,and the removal efficiencies of p-chlorobenzoic( p-CBA) by catalytic ozonation with these activated carbons.Moreover,SCAC was modified with( NH4)2S2O8 and NaOH,to explore the influence of surface functional groups of SCAC on catalytic ozonation activity. The results showed that the amounts of acid and basic functional groups on SCAC were higher than those of the three commercial activated carbons. Results of catalytic ozonation indicated the presence of activated carbons accelerated the removal of p-CBA,and the greatest removal rate was obtained in the presence of SCAC. The removal rate of p-CBA by SCAC /O3 reached 60.2% after 1 min,while the rate was only 26.1% under sole ozonation condition. SCAC after modification with( NH4)2S2O8 and NaOH had an obvious influence on the removal of p-CBA. The basic functional groups on SCAC became abundant after modification with NaOH,and the removal efficiency of p-CBA remarkably increased. But the removal efficiency of p-CBA by SCAC with( NH4)2S2O8 treatment decreased by comparison with SCAC. From the Rct value( [·OH]/[O3]),it is confirmed that basic functional group on SCAC were the main catalytic active sites,which could promote the transformation of ozone into ·OH radicals.