The Release and Migration of Cr in the Soil under Alternating Wet–Dry Conditions
In recent decades, chromium contamination in soil has emerged as a serious environmental issue, demanding an exploration of chromium’s behavioral patterns in different soil conditions. This study aims to simulate the release, migration, and environmental impact of chromium (Cr) in contaminated soils...
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| Format: | Article |
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MDPI AG
2024-02-01
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| Series: | Toxics |
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| Online Access: | https://www.mdpi.com/2305-6304/12/2/140 |
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| author | Zhe Chen Ying Chen Jing Liang Zhiyu Sun Haoren Zhao Yi Huang |
| author_facet | Zhe Chen Ying Chen Jing Liang Zhiyu Sun Haoren Zhao Yi Huang |
| author_sort | Zhe Chen |
| collection | DOAJ |
| description | In recent decades, chromium contamination in soil has emerged as a serious environmental issue, demanding an exploration of chromium’s behavioral patterns in different soil conditions. This study aims to simulate the release, migration, and environmental impact of chromium (Cr) in contaminated soils under natural rainfall conditions (wet–dry cycles). Clean soils sourced from Panzhihua were used to cultivate chromium-containing soils. Simulated rainfall, prepared in the laboratory, was applied to the cultivated chromium-containing soils in indoor simulated leaching experiments. The experiments simulated three years of rainfall in Panzhihua. The results indicate that soils with higher initial Cr contents result in higher Cr concentrations in the leachate, but all soils exhibit a low cumulative Cr release. The leachate shows similar patterns in total organic carbon (TOC), pH, electrical conductivity, and Cr content changes. An analysis of the speciation of Cr in the soil after leaching reveals a significant decrease in the exchangeable fraction for each Cr species, while the residual and oxidizable Cr fractions exhibit notable increases. The wet–dry cycle has the following effects on the soil: it induces internal reduction reactions in the soil, leading to the reduction of Cr(VI) to Cr(III); it alters the binding of Cr ions to the soil, affecting the migration of chromium; and it involves microorganisms in chemical processes that consume organic matter in the soil. After three years of rainwater leaching, chromium-containing soils released a relatively low cumulative amount of total chromium, resulting in a reduced potential risk of groundwater system contamination. Most of the chromium in the chromium-containing soil is fixed within the soil, leading to less biotoxicity. |
| first_indexed | 2024-03-07T22:12:20Z |
| format | Article |
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| institution | Directory Open Access Journal |
| issn | 2305-6304 |
| language | English |
| last_indexed | 2024-03-07T22:12:20Z |
| publishDate | 2024-02-01 |
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| record_format | Article |
| series | Toxics |
| spelling | doaj.art-b1f1ad662e8c4709a8db4c5bcc4c293a2024-02-23T15:36:25ZengMDPI AGToxics2305-63042024-02-0112214010.3390/toxics12020140The Release and Migration of Cr in the Soil under Alternating Wet–Dry ConditionsZhe Chen0Ying Chen1Jing Liang2Zhiyu Sun3Haoren Zhao4Yi Huang5State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, ChinaState Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, ChinaState Key Laboratory of Collaborative Control and Joint Remediation of Soil and Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, ChinaState Key Laboratory of Collaborative Control and Joint Remediation of Soil and Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, ChinaState Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, ChinaState Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, ChinaIn recent decades, chromium contamination in soil has emerged as a serious environmental issue, demanding an exploration of chromium’s behavioral patterns in different soil conditions. This study aims to simulate the release, migration, and environmental impact of chromium (Cr) in contaminated soils under natural rainfall conditions (wet–dry cycles). Clean soils sourced from Panzhihua were used to cultivate chromium-containing soils. Simulated rainfall, prepared in the laboratory, was applied to the cultivated chromium-containing soils in indoor simulated leaching experiments. The experiments simulated three years of rainfall in Panzhihua. The results indicate that soils with higher initial Cr contents result in higher Cr concentrations in the leachate, but all soils exhibit a low cumulative Cr release. The leachate shows similar patterns in total organic carbon (TOC), pH, electrical conductivity, and Cr content changes. An analysis of the speciation of Cr in the soil after leaching reveals a significant decrease in the exchangeable fraction for each Cr species, while the residual and oxidizable Cr fractions exhibit notable increases. The wet–dry cycle has the following effects on the soil: it induces internal reduction reactions in the soil, leading to the reduction of Cr(VI) to Cr(III); it alters the binding of Cr ions to the soil, affecting the migration of chromium; and it involves microorganisms in chemical processes that consume organic matter in the soil. After three years of rainwater leaching, chromium-containing soils released a relatively low cumulative amount of total chromium, resulting in a reduced potential risk of groundwater system contamination. Most of the chromium in the chromium-containing soil is fixed within the soil, leading to less biotoxicity.https://www.mdpi.com/2305-6304/12/2/140chromiumleachinghexavalent chromiumsequential extraction |
| spellingShingle | Zhe Chen Ying Chen Jing Liang Zhiyu Sun Haoren Zhao Yi Huang The Release and Migration of Cr in the Soil under Alternating Wet–Dry Conditions Toxics chromium leaching hexavalent chromium sequential extraction |
| title | The Release and Migration of Cr in the Soil under Alternating Wet–Dry Conditions |
| title_full | The Release and Migration of Cr in the Soil under Alternating Wet–Dry Conditions |
| title_fullStr | The Release and Migration of Cr in the Soil under Alternating Wet–Dry Conditions |
| title_full_unstemmed | The Release and Migration of Cr in the Soil under Alternating Wet–Dry Conditions |
| title_short | The Release and Migration of Cr in the Soil under Alternating Wet–Dry Conditions |
| title_sort | release and migration of cr in the soil under alternating wet dry conditions |
| topic | chromium leaching hexavalent chromium sequential extraction |
| url | https://www.mdpi.com/2305-6304/12/2/140 |
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