Accelerated oxidation of microcystin-LR by Fe(II)-tetrapolyphosphate/oxygen in the presence of magnesium and calcium ions
- Authors
- Kim, Min Sik; Lee, Ki-Myeong; Kim, Hak-Hyeon; Lee, Hongshin; Kim, Dae Won; Kim, Jae-Hong; Lee, Changha
- Issue Date
- 1-10월-2020
- Publisher
- PERGAMON-ELSEVIER SCIENCE LTD
- Keywords
- Microcystin-LR; Oxidation; Tetrapolyphosphate; Ferryl ion; Magnesium; Calcium
- Citation
- WATER RESEARCH, v.184
- Indexed
- SCIE
SCOPUS
- Journal Title
- WATER RESEARCH
- Volume
- 184
- URI
- https://scholar.korea.ac.kr/handle/2021.sw.korea/52522
- DOI
- 10.1016/j.watres.2020.116172
- ISSN
- 0043-1354
- Abstract
- Fe(II)-tetrapolyphosphate complexes are known to activate molecular oxygen (Fe(II)-TPP/O-2) to produce reactive oxidants (most likely, Fe(IV)-TPP complexes) that are capable of degrading refractory organic contaminants in water. This study found that magnesium and calcium ions (Mg2+ and Ca2+) accelerate the degradation of micfrocystin-LR (MC-LR), the most toxic and abundant cyanotoxin, by the Fe(II)-TPP/O-2 system. The addition of Mg2+ and Ca2+ increased the observed rate constant of MC-LR degradation by up to 4.3 and 14.8 folds, respectively. Mg2+ and Ca2+ accelerated the MC-LR degradation in the entire pH range, except for the alkaline region with pH > ca. 10. The addition of Mg2+ and Ca2+ also reshaped the pH-dependency of the MC-LR degradation, greatly increasing the rate of MC-LR degradation at neutral pH. It was found that Mg2+ and Ca2+ accelerate the reaction of Fe(II)-TPP complexes with oxygen, resulting in faster production of reactive oxidants. The findings from cyclic voltammetry and potentiometric titration suggest that Mg2+ and Ca2+ form ternary complexes with Fe(II)-TPP, which exhibit higher reactivity with oxygen. Due to the effects of Mg2+ and Ca2+, the rate of MC-LR degradation by the Fe(II)-TPP/O-2 system was even higher in natural water than in deionized water. (c) 2020 Elsevier Ltd. All rights reserved.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - ETC > 1. Journal Articles
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.