Deciphering the Formation of Fe(IV) in the Fe(II)/Peroxydisulfate Process: The Critical Role of Sulfate Radical.

Environ Sci Technol

Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao 266237, P. R. China.

Published: September 2024

This study delves into the formation of ferryl ions (Fe(IV)) within the Fe(II)/peroxydisulfate (PDS) process, a pivotal reaction in advanced oxidation processes (AOPs) aimed at organic pollutant removal. Our findings challenge the conventional view that Fe(IV) predominantly forms through oxygen transfer from PDS to Fe(II), revealing that sulfate radicals (SO) play a crucial role in Fe(IV) generation. By employing competitive kinetics, the second-order rate constant for Fe(III) oxidation by SO was quantified as 4.58 × 10 M s. Factors such as the probe compound concentration, chloride presence, and iron species influence Fe(IV) generation, all of which were systematically evaluated. Additionally, the study explores Fe(IV) formation in various Fe(II)-activated AOPs, demonstrating that precursors like peroxymonosulfate and HO can also directly oxidize Fe(II) to Fe(IV). Through experimental data, kinetic modeling, and oxygen-18 labeling experiments, this research offers a comprehensive understanding of the Fe(II)/PDS system, facilitating the optimization of AOPs for pollutant degradation. Finally, introducing HSO was proposed to shift the Fe(II)/PDS process from Fe(IV)-dominated to SO-dominated mechanisms, thereby enhancing pollutant removal efficiencies.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.est.4c06675DOI Listing

Publication Analysis

Top Keywords

feiv feii/peroxydisulfate
8
pollutant removal
8
feiv generation
8
feiv
7
deciphering formation
4
formation feiv
4
feii/peroxydisulfate process
4
process critical
4
critical role
4
role sulfate
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!