Abiotic oxidation of Mn(II) and its effect on the oxidation of As(III) in the presence of nano-hematite

Xu Han*, Yi Liang Li, Ji Dong Gu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Manganese (hydr)oxides (MnOx) is a powerful oxidant in the oxidation of As(III) in natural environment. Under some circumstances, Mn(II) can be oxidized to MnOx which in turn accelerates the oxidation of As(III). However, to the best of our knowledge, little is known regarding how Mn(II) affects the oxidation of both the dissolved and the adsorbed As(III) in aquatic environments. In this study, effects of abiotic oxidation of Mn(II) on the oxidation of As(III) were investigated. Kinetic results as well as TEM and XRD analyses confirmed the formation of amorphous MnOx after sorption of Mn(II) on hematite nano-particles under oxic conditions. Mn(II) was oxidized to Mn(III) and then to Mn(IV), and this process was dependent upon pH and Mn(II) concentrations. The newly formed MnOx played an important role in the further oxidation of the dissolved and the adsorbed As(III) on hematite, and the oxidation rate of As(III) increased with the rising Mn(II) concentrations. As the adsorbed As(III) was oxidized to As(V), a fraction of As(V) was released into the solution, which increased the mobility of As. The present study reveals that abiotic oxidation of Mn(II) affects the oxidation of As(III) in aquatic environment.

Original languageEnglish
Pages (from-to)1753-1760
Number of pages8
JournalEcotoxicology
Volume21
Issue number6
DOIs
StatePublished - Aug 2012
Externally publishedYes

Keywords

  • Abiotic oxidation
  • Arsenate
  • Arsenite
  • Mn
  • Mobility

Fingerprint Dive into the research topics of 'Abiotic oxidation of Mn(II) and its effect on the oxidation of As(III) in the presence of nano-hematite'. Together they form a unique fingerprint.

Cite this