Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag

Soil contamination poses an increasing challenge for global sustainable development. Traditional remediation methods, such as using ordinary Portland cement (OPC) for treating contaminated soils, are limited by high CO2 emissions, significant energy consumption, and natural resource depletion. A sus...

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Main Authors: Xu, Bo, Yi, Yaolin
Other Authors: School of Civil and Environmental Engineering
Format: Journal Article
Language:English
Published: 2025
Subjects:
Online Access:https://hdl.handle.net/10356/182266
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author Xu, Bo
Yi, Yaolin
author2 School of Civil and Environmental Engineering
author_facet School of Civil and Environmental Engineering
Xu, Bo
Yi, Yaolin
author_sort Xu, Bo
collection NTU
description Soil contamination poses an increasing challenge for global sustainable development. Traditional remediation methods, such as using ordinary Portland cement (OPC) for treating contaminated soils, are limited by high CO2 emissions, significant energy consumption, and natural resource depletion. A sustainable approach utilizing steel production waste (ladle slag, LS) to efficiently remediate copper (Cu)-contaminated soils was proposed in this study. The efficacy of this remediation using carbonation and conventional curing methods was compared. Cu-contaminated soils, spiked with varying initial concentrations, were treated with 10 % LS and subjected to both conventional and carbonation curing for different durations. Leaching behavior, strength development, and chemical and mineral properties of LS-remediated Cu-contaminated soils were assessed. The results demonstrated that both CO2 and conventional curing significantly reduced Cu leaching in contaminated soils by 4–5 orders of magnitude compared to untreated soils. CO2 curing achieved these reductions in a shorter time (56–72 hours) than conventional curing (28–56 days). Additionally, CO2 curing sequestered up to 8 % CO2 in the soils. However, higher Cu concentrations hindered carbonation reactions, lowering CO2 sequestration. While CO2 curing improved soil strength, increased initial Cu concentration diminished this effect. During CO2 curing, the formation of Ca- and Mg-carbonates contributed to microstructural densification and binding, thereby improving strength. These carbonates also encapsulated Cu, preventing its leaching. In contrast, the addition of Cu enhanced hydration reactions and improved the strength development of Cu-contaminated soils subjected to conventional curing. Conventional curing produced calcium aluminum silicate hydrate, which effectively bound soil particles, filled pores, and encapsulated Cu, reducing its leaching.
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spelling ntu-10356/1822662025-01-24T15:34:11Z Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag Xu, Bo Yi, Yaolin School of Civil and Environmental Engineering Engineering Carbon capture Ladle slag Soil contamination poses an increasing challenge for global sustainable development. Traditional remediation methods, such as using ordinary Portland cement (OPC) for treating contaminated soils, are limited by high CO2 emissions, significant energy consumption, and natural resource depletion. A sustainable approach utilizing steel production waste (ladle slag, LS) to efficiently remediate copper (Cu)-contaminated soils was proposed in this study. The efficacy of this remediation using carbonation and conventional curing methods was compared. Cu-contaminated soils, spiked with varying initial concentrations, were treated with 10 % LS and subjected to both conventional and carbonation curing for different durations. Leaching behavior, strength development, and chemical and mineral properties of LS-remediated Cu-contaminated soils were assessed. The results demonstrated that both CO2 and conventional curing significantly reduced Cu leaching in contaminated soils by 4–5 orders of magnitude compared to untreated soils. CO2 curing achieved these reductions in a shorter time (56–72 hours) than conventional curing (28–56 days). Additionally, CO2 curing sequestered up to 8 % CO2 in the soils. However, higher Cu concentrations hindered carbonation reactions, lowering CO2 sequestration. While CO2 curing improved soil strength, increased initial Cu concentration diminished this effect. During CO2 curing, the formation of Ca- and Mg-carbonates contributed to microstructural densification and binding, thereby improving strength. These carbonates also encapsulated Cu, preventing its leaching. In contrast, the addition of Cu enhanced hydration reactions and improved the strength development of Cu-contaminated soils subjected to conventional curing. Conventional curing produced calcium aluminum silicate hydrate, which effectively bound soil particles, filled pores, and encapsulated Cu, reducing its leaching. Ministry of Education (MOE) Published version This research work is supported by the Ministry of Education, Singapore, under its Academic Research Fund Tier 2 (MOE-T2EP50220-0004). 2025-01-20T04:28:13Z 2025-01-20T04:28:13Z 2024 Journal Article Xu, B. & Yi, Y. (2024). Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag. Journal of CO2 Utilization, 90, 102981-. https://dx.doi.org/10.1016/j.jcou.2024.102981 2212-9820 https://hdl.handle.net/10356/182266 10.1016/j.jcou.2024.102981 2-s2.0-85209948959 90 102981 en MOE-T2EP50220-0004 Journal of CO2 Utilization © 2024 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/). application/pdf
spellingShingle Engineering
Carbon capture
Ladle slag
Xu, Bo
Yi, Yaolin
Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag
title Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag
title_full Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag
title_fullStr Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag
title_full_unstemmed Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag
title_short Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag
title_sort comparison of the efficacy of carbonation and conventional curing for remediation of copper contaminated soils by ladle slag
topic Engineering
Carbon capture
Ladle slag
url https://hdl.handle.net/10356/182266
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