Enhancement effect and mechanism of 1-Hydroxyethylidene-1,1-diphosphonic acid on Fe2+activated O2 degrading pollutants
1-Hydroxyethylidene-1,1-diphosphonic acid(HEDP)often formed Fe2+-HEDP complexes with Fe2+.In this study,HEDP was verified to promote the production of reactive oxygen species(ROS)from Fe2+activated molecular oxygen.The results showed that after adding 2mmol/L of HEDP,the degradation effect of phenol(10mg/L)in the Fe2+/O2 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 O2·-,and the two-electron transfer pathway(O2 →H2O2 → 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.