Rapid activation of peroxymonosulfate with iron(Ⅲ) complex for organic pollutants degradation via a non-radical pathway.

Developing high-performance catalytic systems for eliminating contaminants effectively in water has received a lot of attention. However, the complexity of practical wastewater poses a challenge for degrading organic pollutants. Non-radical active species with strong resistance to interference have shown great advantages in degrading organic pollutants under complex aqueous conditions. Herein, a novel system was constructed by Fe(dpa)Cl (FeL, dpa = N, N'-(4-nitro-1,2-phenylene) dipicolinamide) activating peroxymonosulfate (PMS). The mechanism study verified that the FeL/PMS system had high efficiency in producing high-valent iron-oxo and singlet oxygen (O) to degrade various organic pollutants. In addition, the chemical bonding between PMS and FeL was elucidated by the density functional theory (DFT) calculations. The FeL/PMS system could remove 96% Reactive Red 195 (RR195) in 2 min, which was much higher than other systems involved in this study. More attractively, the FeL/PMS system demonstrated general resistance to interference from common anions (Cl, HCO, NO and SO), humic acid (HA) and pH changes and were thus compatible with various natural waters. This work provides a new approach for producing non-radical active species, which is a promising catalytic system for water treatment.