Issue 1, 2020

Predicting Cr(vi) adsorption on soils: the role of the competition of soil organic matter

Abstract

Cr(VI) has posed a serious risk for the environment and human beings because of its pollution and toxicity. It is essential to understand the equilibrium behavior of Cr(VI) in soils. In this study, the adsorption of Cr(VI) on fourteen soils was studied with batch experiments and quantitative modeling. The batch experiments included the adsorption edge and adsorption isotherm experiments, investigating the adsorption of Cr(VI) with varying soil properties, solution pH, and initial Cr(VI) concentrations. The experimental data were then modeled using the surface complexation models in Visual MINTEQ of CD-MUSIC by considering the adsorption of Cr(VI) and ions onto Fe (hydr)oxides and Al (hydr)oxides, and the Stockholm Humic Model and the fixed charge site model by accounting for the adsorption of the cations to soil organic matter and clay, respectively. Particularly, the modeling method of this study introduced an important parameter RO to account for the amount of soil organic matter irreversibly adsorbed on soil minerals. Overall, the model predicted reasonably well for the equilibrium partition of Cr(VI) under various conditions with a root-mean-square-error of 0.35 for the adsorption edge data and 0.19 for the adsorption isotherm data. According to the model calculations, ferrihydrite dominated the binding of Cr(VI) at pH of 3.0–7.0. The content of ferrihydrite and reactive soil organic matter was found to be the main factor influencing RO. The modeling results help to understand and predict Cr(VI) adsorption on different soils and are beneficial to environmental risk assessment and pollution remediation.

Graphical abstract: Predicting Cr(vi) adsorption on soils: the role of the competition of soil organic matter

Supplementary files

Article information

Article type
Paper
Submitted
19 okt. 2019
Accepted
07 des. 2019
First published
09 des. 2019

Environ. Sci.: Processes Impacts, 2020,22, 95-104

Predicting Cr(VI) adsorption on soils: the role of the competition of soil organic matter

Z. Shi, S. Peng, X. Lin, Y. Liang, S. Lee and H. E. Allen, Environ. Sci.: Processes Impacts, 2020, 22, 95 DOI: 10.1039/C9EM00477G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements