羟基乙叉二膦酸对Fe^(2+)活化O_(2)降解污染物的强化效果及机制

Enhancement effect and mechanism of 1-Hydroxyethylidene-1,1-diphosphonic acid on Fe^(2+)activated O_(2) degrading pollutants

羟基乙叉二膦酸(HEDP)常与Fe^(2+)形成Fe^(2+)-HEDP配合物,本文验证了HEDP存在可以促进Fe^(2+)活化分子氧产生活性自由基(ROS),研究结果显示添加2mmol/L HEDP后,Fe^(2+)/O_(2)体系中苯酚(10mg/L)的降解效果从0.69%提升到69.31%,在此过程中,体系中的HEDP还能够实现部分自降解.电子自旋共振(ESR)和掩蔽实验结果表明体系中主要ROS为HO^(•)和O_(2)^(•–),双电子传递途径(O_(2)→H_(2)O_(2)→HO^(•))是体系中产生HO^(•)的主要方式.在3.0~9.0的pH值范围内,HEDP都能够促进ROS的产生和污染物的降解,常见环境阴离子对体系影响较小.

1-Hydroxyethylidene-1,1-diphosphonic acid(HEDP)often formed Fe^(2+)-HEDP complexes with Fe^(2+).In this study,HEDP was verified to promote the production of reactive oxygen species(ROS)from Fe^(2+)activated molecular oxygen.The results showed that after adding 2mmol/L of HEDP,the degradation effect of phenol(10mg/L)in the Fe^(2+)/O_(2)system increased from 0.69%to 69.31%.In the process,the HEDP in the system was partially self-degraded.The results of electron spin resonance(ESR)and quenching experiments indicated that the main ROS in the system were HO^(•)and O_(2)^(•-),and the two-electron transfer pathway(O_(2)→H_(2)O_(2)→HO^(•))was the main way to generate HO•.Within the pH range of 3.0~9.0,HEDP stimulated the generation of ROS and facilitated the degradation of pollutants.Besides,the presence of common environmental anions had minimal influence on the system.