Immobilization of Cr(VI) on engineered silicate nanoparticles : Microscopic mechanisms and site energy distribution

Copyright © 2019 Elsevier B.V. All rights reserved..

Engineered nanoparticles-mediated contaminant transport has been recognized as a significant process governing the mobility of metals and radionuclides in groundwater. Engineered silicate nanoparticles (ESNPs) are attractive materials for the sequestration or extraction of Cr(VI) and other metals and radionuclides from groundwater. While great efforts have been devoted toward the application of these materials for Cr(VI) sequestration, the underlying interface adsorption mechanism is not thoroughly elucidated. This study investigates the immobilization mechanisms of Cr(VI) on a representative ESNPs, NH2-MCM-41, over a range of water chemistry conditions. By combining batch adsorption experiments with an array of complementary characterizations, we provided spectroscopic and microscopic evidence that the electrostatic interactions between the positively charged NH2-MCM-41 surface derived from amino functionality and the negatively charged Cr(VI) species was the dominant mechanism responsible for Cr(VI) immobilization. In addition, the weak hydrogen bonding interactions may also contribute to adsorption to a degree. Furthermore, thermodynamic studies suggested a favorable, spontaneous, and exothermic adsorption process. Site energy analysis illustrated that the distribution of energy binding sites on NH2-MCM-41 is Cr(VI) loading dependent. The new insights provided here can advance understanding of the transport of Cr(VI) associated NH2-MCM-41 that benefits the application of ESNPs-based technologies for metals immobilization in groundwater.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:383

Enthalten in:

Journal of hazardous materials - 383(2020) vom: 05. Feb., Seite 121145

Sprache:

Englisch

Beteiligte Personen:

Liao, Peng [VerfasserIn]
Li, Binrui [VerfasserIn]
Xie, Lin [VerfasserIn]
Bai, Xiaoao [VerfasserIn]
Qiao, Han [VerfasserIn]
Li, Qianqian [VerfasserIn]
Yang, Biwei [VerfasserIn]
Liu, Chongxuan [VerfasserIn]

Links:

Volltext

Themen:

Engineered silicate nanoparticles
Hexavalent chromium
Immobilization
Journal Article
Microscopic mechanism
Research Support, Non-U.S. Gov't
Site energy distribution

Anmerkungen:

Date Completed 03.03.2020

Date Revised 03.03.2020

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1016/j.jhazmat.2019.121145

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM301305218