Jump to main content
US EPA
United States Environmental Protection Agency
Search
Search
Main menu
Environmental Topics
Laws & Regulations
About EPA
Health & Environmental Research Online (HERO)
Contact Us
Print
Feedback
Export to File
Search:
This record has one attached file:
Add More Files
Attach File(s):
Display Name for File*:
Save
Citation
Tags
HERO ID
7854519
Reference Type
Journal Article
Title
Transformation of Hexagonal Birnessite upon Reaction with Thallium(I): Effects of Birnessite Crystallinity, pH, and Thallium Concentration
Author(s)
Ruiz-Garcia, M; Villalobos, M; Voegelin, A; Pi-Puig, T; Martínez-Villegas, N; Göttlicher, J
Year
2021
Is Peer Reviewed?
1
Journal
Environmental Science & Technology
ISSN:
0013-936X
EISSN:
1520-5851
Volume
55
Issue
8
Page Numbers
4862-4870
Language
English
PMID
33764067
DOI
10.1021/acs.est.0c07886
Web of Science Id
WOS:000643546400066
URL
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104913078&doi=10.1021%2facs.est.0c07886&partnerID=40&md5=478477082106dfab64ce6dc84cb49b48
Exit
Abstract
We examined the uptake of Tl(I) by two hexagonal birnessites and related phase transformations in laboratory experiments over 12 sequential additions of 0.01 M Tl(I)/Mn at pH 4.0, 6.0, and 8.0. The Tl-reacted Mn oxides were characterized for their structure, Tl binding, and morphology using X-ray diffraction, X-ray photoelectron and X-ray absorption spectroscopies, and transmission electron microscopy. Very limited Tl oxidation was observed in contrast to previous works, where equal Tl(I)/Mn was added in a single step. Instead, both birnessites transformed into a 2 × 2 tunneled phase with dehydrated Tl(I) in its tunnels at pH 4, but only partially at pH 6, and at pH 8.0 they remained layered. The first four to nine sequential Tl(I)/Mn additions resulted in lower residual dissolved Tl+ concentrations than when the same amounts of Tl(I)/Mn were added in single steps. This study thus shows that the repeated reaction of hexagonal birnessites with smaller Tl(I)/Mn at ambient temperature triggers a complete phase conversion with Tl(I) as the sole reacting cation. The novel pathway found may be more relevant for contaminated environments and may help explain the formation of minerals like thalliomelane [Tl+(Mn7.54+Cu0.52+)O16]; it also points to the possibility that other reducing species trigger similar Mn oxide transformation reactions.
Home
Learn about HERO
Using HERO
Search HERO
Projects in HERO
Risk Assessment
Transparency & Integrity