Electrochemical monitoring of metal ions removal in Fe-0/H2O systems: competitive effects of cations Zn2+, Pb2+, and Cd2+

0536196 - ÚFCH JH 2021 RIV AT eng J - Journal Article
Touomo-Wouafo, M. - Donkeng Dazie, Joel - Jirka, Ivan - Btatkeu-K, B.D. - Tchatchueng, J. B. - Noubactep, Ch. - Ludvík, Jiří
Electrochemical monitoring of metal ions removal in Fe-0/H2O systems: competitive effects of cations Zn2+, Pb2+, and Cd2+.
Monatshefte fur Chemie. Roč. 151, č. 10 (2020), s. 1511-1523. ISSN 0026-9247. E-ISSN 1434-4475
Institutional support: RVO:61388955
Keywords : zero-valent iron * aqueous-solution * environmental remediation * adsorption * cu * corrosion * water * contamination * spectroscopy * efficiency * Heavy metals * Multiple cations * Electrochemistry * Water treatment * Aged zero-valent iron
OECD category: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)
Impact factor: 1.451, year: 2020
Method of publishing: Limited access

Metallic iron (Fe-0) is a reactive material that is widely used for industrial water treatment. The course of the metal ion removal process using Fe-0(iron powder) was monitored electrochemically (differential pulse polarography). As probe species, Zn2+, Pb2+, and Cd(2+)were selected for their different (1) adsorptive affinity to iron corrosion products (FeCPs), (2) redox properties, (3) precipitation ability at various pH. Batch experiments were carried out with binary (Zn2+/ Pb(2+)and Zn2+/ Cd2+) and ternary (Zn2+/Cd2+/Pb2+) systems to reveal the mutual interference of these cations. Detailed time monitoring of iron aging for up to 14 days as well as concentration decay of individual removed cations represent important data for mechanistic discussions. The aqueous concentration of Fe(2+)was also monitored. FeCPs were characterized using X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Results showed that the presence of Pb(2+)delays the Zn(2+)removal whereas the presence of Cd(2+)in solution accelerates its removal. The removal of Pb(2+)by FeCPs was not affected by the presence of Zn(2+)and Cd2+, moreover, the Pb(2+)inhibited the effect of Cd(2+)on the removal of Zn2+. XPS has proven existence of Fe(2)O(3)and hydrated Fe oxidic phase, whilst the SEM showed that the original Fe grains were partly dissolved into buffered ambient under formation of fine particles of FeCPs. Results confirm that reductive transformation of any contaminant in a Fe-0/H2O system is the consequence and not the cause of iron corrosion.
Permanent Link: http://hdl.handle.net/11104/0314003