吡啶强化亚铁活化过硫酸盐降解有机污染物

Bipyridine Enhanced the Degradation of Organic Contaminants in the Fe(Ⅱ)/Peroxymonosulfate Process

适用p H范围窄是限制亚铁/过一硫酸盐(Fe(Ⅱ)/PMS)体系进一步推广应用的关键因素之一,亟需开发拓宽Fe(Ⅱ)/PMS体系适用p H范围的策略。该文旨在探究含氮络合剂1,10-邻菲罗啉(phen)和2,2'-联吡啶(bipy)对Fe(Ⅱ)/PMS体系降解有机污染物效能和机制的影响。结果表明,引入phen和bipy可显著促进Fe(Ⅱ)/PMS体系对富含供电子基团的有机污染物苯酚和双氯芬酸的降解。当phen/Fe(Ⅱ)和bipy/Fe(Ⅱ)的摩尔比分别为3.0和4.5时,phen/Fe(Ⅱ)/PMS和bipy/Fe(Ⅱ)/PMS体系对苯酚的去除效果最佳。phen/Fe(Ⅱ)/PMS和bipy/Fe(Ⅱ)/PMS体系在p H 3.0~9.0条件下均能有效降解苯酚。化学探针、电子顺磁共振和淬灭剂实验结果表明,phen/Fe(Ⅱ)/PMS和bipy/Fe(Ⅱ)/PMS体系产生的活性氧化剂包括^(1)O_(2)和Fe(Ⅳ),且^(1)O_(2)对这2个体系中苯酚的降解起主要作用。

The narrow working pH range is one of the key factors limiting the widespread application of the ferrous iron/peroxymonosulfate(Fe(Ⅱ)/PMS)system,and there is an urgent need to develop strategies to broaden the working pH range of the Fe(Ⅱ)/PMS system.This study aims to investigate the impact of nitrogen-containing complexing agents,1,10-phenanthroline(phen)and 2,2'-bipyridine(bipy),on the efficiency and mechanism of organic pollutant degradation in the Fe(Ⅱ)/PMS process.The results indicate that the introduction of phen and bipy significantly enhances the degradation of organic pollutants containing electron-donating groups,such as phenol and diclofenac in the Fe(Ⅱ)/PMS system.When the molar ratios of phen/Fe(Ⅱ)and bipy/Fe(Ⅱ)are 3.0 and 4.5,respectively,the phen/Fe(Ⅱ)/PMS and bipy/Fe(Ⅱ)/PMS systems achieve the best removal for phenol.Both phen/Fe(Ⅱ)/PMS and bipy/Fe(Ⅱ)/PMS systems could efficiently degrade phenol within the pH range of 3.0~9.0.The results obtained from chemical probe,electron paramagnetic resonance,and quenching experiments reveal that ^(1)O_(2) and Fe(Ⅳ)are the primary active oxidants in the phen/Fe(Ⅱ)/PMS and bipy/Fe(Ⅱ)/PMS systems and that ^(1)O_(2) plays a major role in the degradation of phenol in both systems.