Photochemical transformation and immobilization of thallium in the presence of iron and arsenic : Mechanistic insights from the coupled formation of arsenate complexes

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Despite the occurrence of thallium (Tl) in the acidic mining-affected areas being highly positively correlated with iron (Fe) and arsenic (As), the effects of the two accompanying elements on Tl redox transformation and immobilization remain largely unknown. Here, we investigated the photochemical redox kinetics and immobilization efficiency of Tl for a wide range of As/Fe and As/Tl ratios under acidic conditions. We provided the first experimental confirmation of the complexation of Tl(III) with As(V) by the spectrophotometric method and revealed the role of Tl(III)-As(V) complexes in decreasing the photoreduction rate of Tl(III) under sunlight. Additionally, the negative impact of colloidal Fe(III)-As(V) and Fe(III)-As(III) complexes formation on decreasing photoactive Fe(III) speciation and thus the apparent quantum yield of •OH was highlighted, which consequently hindered the oxidative conversion of Tl(I) to Tl(III). We rationalize the kinetics results by developing the model which quantitatively describes the photochemistry of Tl. Furthermore, we demonstrated the colloid-facilitated immobilization of Tl(III) through the formation of Tl(III)-As(V) clusters and surface adsorption onto the complexes. This study broadens the mechanistic understanding of redox transformation and immobilization potential of Tl and aids in assessing Tl speciation as well as its coupled transformation with Fe and As species in the sunlit water environment.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:469

Enthalten in:

Journal of hazardous materials - 469(2024) vom: 05. Apr., Seite 134081

Sprache:

Englisch

Beteiligte Personen:

Ma, Chengxue [VerfasserIn]
Li, Hongye [VerfasserIn]
Huangfu, Xiaoliu [VerfasserIn]
Huang, Ruixing [VerfasserIn]
Ma, Jun [VerfasserIn]

Links:

Volltext

Themen:

Arsenate-iron complexes
Arsenate-thallium complexes
Immobilization
Journal Article
Photochemical transformation
Thallium

Anmerkungen:

Date Revised 06.04.2024

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1016/j.jhazmat.2024.134081

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM37011776X