First-principles investigations of arsenate doping into the ettringite lattice

Zhao, Yingliang; Sun, Yong; Guo, Z.; Qiu, Jingping; Sun, Xiaogang

doi:10.1016/j.jclepro.2023.138266

First-principles investigations of arsenate doping into the ettringite lattice

Title

First-principles investigations of arsenate doping into the ettringite lattice

Author

Zhao, Yingliang (The Hong Kong Polytechnic University; Northeastern University)
Sun, Yong (Northeastern University)
Guo, Z. (TU Delft Rivers, Ports, Waterways and Dredging Engineering; Northeastern University)
Qiu, Jingping (Northeastern University)
Sun, Xiaogang (Northeastern University)

Date

2023

Abstract

Hazardous wastes are commonly immobilized using cementitious materials. Ettringite (Ca₆Al₂(OH)₁₂(SO₄)₃∙26H₂O) is one of the main components of hydrated cement and is known to stabilize anionic species. Thus, it is a promising material for the stabilization of arsenate (As(V)) in cementitious waste streams. However, the effects of As(V) incorporation into the ettringite structure on the structural properties of As and ettringite remain unclear. Herein, As(V) doping into the structure of ettringite was investigated based on the first-principles calculations using density functional theory (DFT), and the results suggested that the mechanism involving the substitution of AsO₄ ³⁻ by SO₄ ²⁻ was energetically favorable and that As doping increased the total bond order of ettringite, leading to a more stable structure. The elastic properties and anisotropy of ettringite and As-doped ettringite were also investigated using DFT calculations. The results showed that the mechanical properties of the As-doped ettringite structure were stable according to Born's criterion. Moreover, As doping increased the elastic constants and elastic modulus of ettringite but reduced its elastic anisotropy. These results provide valuable insights into the long-term stabilization of As species and their migration in cementitious wastes.

Subject

Arsenate
Elastic properties
Ettringite
First-principles calculations
Isomorphic substitution

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DOI

https://doi.org/10.1016/j.jclepro.2023.138266

Embargo date

2024-01-26

ISSN

0959-6526

Source

Journal of Cleaner Production, 419

Bibliographical note

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Part of collection

Institutional Repository

Document type

journal article

Rights

Files

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