Halide-induced dissolution of lead(IV) oxide in frozen solution

Sunil Paul M Menacherry; Dae Wi Min; Daun Jeong; Charuvila T Aravindakumar; Woojin Lee; Wonyong Choi

doi:10.1016/j.jhazmat.2019.121298

Halide-induced dissolution of lead(IV) oxide in frozen solution

J Hazard Mater. 2020 Feb 15:384:121298. doi: 10.1016/j.jhazmat.2019.121298. Epub 2019 Sep 24.

Authors

Sunil Paul M Menacherry¹, Dae Wi Min², Daun Jeong², Charuvila T Aravindakumar³, Woojin Lee⁴, Wonyong Choi⁵

Affiliations

¹ Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea; School of Environmental Sciences, Mahatma Gandhi University, Kottayam, India.
² Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea.
³ School of Environmental Sciences, Mahatma Gandhi University, Kottayam, India.
⁴ Department of Civil and Environmental Engineering, Nazarbayev University, Astana, 010000, Kazakhstan.
⁵ Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea. Electronic address: wchoi@postech.edu.

PMID: 31585282
DOI: 10.1016/j.jhazmat.2019.121298

Abstract

The dark dissolution behavior of plattnerite (ß-PbO₂) was investigated in frozen solutions containing halide ions and compared with those in aqueous solution. The amount of dissolved lead in the frozen solutions varied depending on the solution pH and the kind and concentration of halide ions. The presence of bromide and iodide ions enhanced the dissolution of lead in the aqueous phase, whereas the effect of chloride was insignificant. Compared with the aqueous phase dissolution, ß-PbO₂ dissolution in the frozen solution was slightly enhanced in the presence of bromide but suppressed in the presence of iodide. Iodide ions seemed to be relatively more trapped in the bulk ice (ice-crystal lattice) than bromide ions, which might be related to the suppressed dissolution of lead oxide in the presence of iodide. The co-existence of bromide (or iodide) and chloride ions in the frozen solution enhanced the dissolution of lead, which seems to be enabled by an additional reaction pathway involving the formation of mixed halide radicals, whereas such kind of synergistic enhancements were not observed in aqueous solution. The halide-induced lead oxide dissolution in frozen solutions can be related to the behavior of lead ions found in various media of frozen environments.

Keywords: Chemical reactions in frozen solution; Freeze concentration; Ice; Lead oxide; Mineral dissolution.

Publication types

Research Support, Non-U.S. Gov't