New Insights into the FeO/Peroxymonosulfate Process for Organics Removal: The Synergistic Effect of Radicals and Fe(IV)

• Published in: ACS ES&T engineering 2023-11, Vol.3 (11), p.1886-1897
• Main Authors: Zeng, Baitian, Long, Liying, Chen, Yiqun, Liu, Zizheng, Luo, Liting, Shao, Qing, Xie, Pengchao, Ma, Jun
• Format: Article
• Language: English
• ISSN: 2690-0645; 2690-0645
• DOI: 10.1021/acsestengg.3c00260

The FeO/peroxymonosulfate (PMS) system was explored in this work for the removal of bisphenol A (BPA) as a target pollutant. FeO demonstrated the highest PMS activation ability among the common iron oxides. 95.4% of the BPA could be removed in 30 min at pH 4.0 with the addition of 300 mg/L FeO and 50 μM PMS, mostly due to heterogeneous catalysis. The coexisting inorganic anions and natural organic matter impacted BPA breakdown. In the FeO/PMS system, high-valent Fe­(IV), SO4 •–, and HO• were produced, which collectively caused the hydroxylation of the benzene ring in the BPA molecule. Remarkably, these reactive species had distinct effects on eliminating substrates, with electron-rich pollutants more likely to experience electrophilic reactions with Fe­(IV) and electron-deficient pollutants more susceptible to HO• attack. Compared to other FeO/peroxide systems, the FeO/PMS system had a better oxidation capacity under the experimental conditions, and it continued to function effectively in real water. Additionally, in a 96 h continuous flow treatment, the FeO/PMS system demonstrated a sustained effect. As a result, this system is anticipated to be a successful advanced oxidation technique for eliminating organic micropollutants existing in water.