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Xu ZL, Xu DM, Li HX, Li HK, Fu RB. The longevity evaluation of multi-metal stabilization by MgO in Pb/Zn smelter-contaminated soils. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:28153-28165. [PMID: 38528219 DOI: 10.1007/s11356-024-32790-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 03/01/2024] [Indexed: 03/27/2024]
Abstract
The re-mobilization risks of potentially toxic elements (PTEs) during stabilization deserve to be considered. In this study, artificial simulation evaluation methods based on the environmental stress of freeze-thaw (F-T), acidification and variable pH were conducted to assess the long-term effectiveness of PTEs stabilized by MgO in Pb/Zn smelter contaminated soils. Among common stabilizing materials, MgO was considered as the best remediation material, since PTEs bioavailability reduced by 55.48% for As, 19.58% for Cd, 10.57% for Cu, and 26.33% for Mn, respectively. The stabilization effects of PTEs by MgO were best at the dosage of 5 wt%, but these studied PTEs would re-mobilize after 30 times F-T cycles. Acid and base buffering capacity results indicated that the basicity of contaminated soils with MgO treatment reduced under F-T action, and the leached PTEs concentrations would exceed the safety limits of surface water quality standard in China (GB3838-2002) after acidification of 2325 years. No significant changes were found in the pH-dependent patterns of PTEs before and after F-T cycles. However, after F-T cycles, the leaching concentrations of PTEs increased due to the destruction of soil microstructure and the functionality of hydration products formed by MgO, as indicated by scanning electron microscopy (SEM) coupled with energydispersive Xray spectroscopy (EDS) results. Hence, these findings would provide beneficial references for soil remediation assessments of contaminated soils under multi-environmental stress.
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Affiliation(s)
- Ze-Lin Xu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China
- Centre for Environmental Risk Management and Remediation of Soil and Groundwater, Tongji University, Shanghai, 200092, People's Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China
| | - Da-Mao Xu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China
- Centre for Environmental Risk Management and Remediation of Soil and Groundwater, Tongji University, Shanghai, 200092, People's Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China
| | - Hai-Xuan Li
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China
- Centre for Environmental Risk Management and Remediation of Soil and Groundwater, Tongji University, Shanghai, 200092, People's Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China
| | - Hao-Kai Li
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China
- Centre for Environmental Risk Management and Remediation of Soil and Groundwater, Tongji University, Shanghai, 200092, People's Republic of China
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China
| | - Rong-Bing Fu
- State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China.
- Centre for Environmental Risk Management and Remediation of Soil and Groundwater, Tongji University, Shanghai, 200092, People's Republic of China.
- Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, People's Republic of China.
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Xu Z, Nie N, Liu K, Li Q, Cui H, Du H. Analog soil organo-ferrihydrite composites as suitable amendments for cadmium and arsenic stabilization in co-contaminated soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 877:162929. [PMID: 36934932 DOI: 10.1016/j.scitotenv.2023.162929] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 05/06/2023]
Abstract
Remediation of CdAs co-contaminated soils has long been considered a difficult problem to solve, as Cd and As have distinctly different metallic characters. Amending contaminated soils with traditional single passivation materials may not always work well in the stabilization of both Cd and As. Here, we reported that analog soil organo-ferrihydrite composites made with either living or non-living organics (bacterial cells or humic acid) could achieve stabilization of both Cd and As in contaminated soils. BCR and Wenzel sequential extractions showed that organo-ferrihydrite, particularly at 1 wt% loading, shifted liable Cd and As to more stable phases. Organo-ferrihydrite amendments significantly (p < 0.05) increased soil urease, alkaline phosphatase and catalase enzyme activities. With organo-ferrihydrite amendments, the bioavailable fraction of Cd decreased to 35.3 % compared with the control (65.1 %), while the bioavailable As declined from 29.4 % to 12.4%. Soil pH, microbial community abundance and diversity were almost unaffected by organo-ferrihydrite. Ferrihydrite and organo fractions both contributed to direct Cd-binding, while the organo fraction probably maintained the Fe-bound As via lowering ferrihydrite phase transformation. Compared to pure ferrihydrite, organo-ferrihydrite composites performed better not only in reducing liable Cd and As, but also in maintaining soil quality and ecosystem functions. This study demonstrates the applications of organo-ferrihydrite composites in eco-friendly remediation of CdAs contaminated soils, and provides a new direction in selecting appropriate soil amendments.
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Affiliation(s)
- Zelin Xu
- College of Resources and Environment, Hunan Agricultural University, 410127 Changsha, China; College of Environmental Science and Engineering, Tongji University, 200092 Shanghai, China
| | - Ning Nie
- College of Resources and Environment, Hunan Agricultural University, 410127 Changsha, China
| | - Kaiyan Liu
- College of Resources and Environment, Hunan Agricultural University, 410127 Changsha, China
| | - Qi Li
- Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
| | - Haojie Cui
- College of Resources and Environment, Hunan Agricultural University, 410127 Changsha, China
| | - Huihui Du
- College of Resources and Environment, Hunan Agricultural University, 410127 Changsha, China.
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