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Tian S, Liu Z, Mao Q, Ye H, Tian C, Zhu Y, Zhang L. Leaching characteristics and environmental impact of heavy metals in tailings under rainfall conditions: A case study of an ion-adsorption rare earth mining area. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 281:116642. [PMID: 38941660 DOI: 10.1016/j.ecoenv.2024.116642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 06/21/2024] [Accepted: 06/22/2024] [Indexed: 06/30/2024]
Abstract
Following ion-adsorption rare earth mining, the residual tailings experience considerable heavy metal contamination and gradually evolve into a pollution source. Therefore, the leaching characteristics and environmental impact of heavy metals in ion-adsorption rare earth tailings require immediate and thorough investigation. This study adopted batch and column experiments to investigate the leaching behaviour of heavy metals in tailings and assess the impact of tailings on paddy soil, thereby providing a scientific basis for environmental protection in mining areas. The results showed that Mn, Zn, and Pb contents were 431.67, 155.05, and 264.33 mg·kg-1, respectively, which were several times higher than their respective background values, thereby indicating significant heavy metal contamination in the tailings. The batch leaching experiment indicated that Mn and Pb were priority control heavy metals. Heavy metals were divided into fast and slow leaching stages. The Mn and Pb leaching concentrations far exceeded environmental limits. The DoseResp model perfectly fitted the leaching of all heavy metals from the tailings (R2 > 0.99). In conjunction with the findings of the column experiment and correlation analysis, the chemical form, rainfall pH, ammonia nitrogen, and mineral properties were identified as the primary factors controlling heavy metal release from tailings. Rainfall primarily caused heavy metal migration in the acid-extraction form from the tailings. The tailing leachate not only introduced heavy metals into the paddy soil but also caused the transformation of the chemical form of heavy metals in the paddy soil, further exacerbating the environmental risk posed by heavy metals. The study findings are significant for environmental conservation in mining areas and implementing environmentally friendly practices in rare earth mining.
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Affiliation(s)
- Shuai Tian
- Jiangxi Provincial Key Laboratory of Environmental Pollution Prevention and Control in Mining and Metallurgy, Jiangxi University of Science and Technology, Ganzhou 341000, China; School of Resources Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
| | - Zuwen Liu
- Jiangxi Provincial Key Laboratory of Environmental Pollution Prevention and Control in Mining and Metallurgy, Jiangxi University of Science and Technology, Ganzhou 341000, China; School of Resources Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China; Jiangxi Province Key Laboratory of Environmental Geotechnical Engineering and Hazards Control, Jiangxi University of Science and Technology, Ganzhou 341000, China; National-local Joint Engineering Laboratory of Water Engineering Safety and Efficient Utilization of Resources in Poyang Lake Watershed, Nanchang Institute of Technology, Nanchang 330099, China.
| | - Qing Mao
- Jiangxi Province Key Laboratory of Environmental Geotechnical Engineering and Hazards Control, Jiangxi University of Science and Technology, Ganzhou 341000, China
| | - Hongmei Ye
- Jiangxi Provincial Key Laboratory of Environmental Pollution Prevention and Control in Mining and Metallurgy, Jiangxi University of Science and Technology, Ganzhou 341000, China; School of Resources Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
| | - Changshun Tian
- School of Resources and Architectural Engineering, Gannan University of Science and Technology, Ganzhou 341000, China.
| | - Yichun Zhu
- School of Resources Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China; Jiangxi Province Key Laboratory of Environmental Geotechnical Engineering and Hazards Control, Jiangxi University of Science and Technology, Ganzhou 341000, China
| | - Linan Zhang
- Jiangxi Provincial Key Laboratory of Environmental Pollution Prevention and Control in Mining and Metallurgy, Jiangxi University of Science and Technology, Ganzhou 341000, China; School of Resources Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China
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Ge J, Wu S, Wu H, Lin J, Cai Y, Zhou D, Gu X. Prediction of As and Cd dissolution in various soils under flooding condition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 948:174853. [PMID: 39038669 DOI: 10.1016/j.scitotenv.2024.174853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Revised: 07/10/2024] [Accepted: 07/15/2024] [Indexed: 07/24/2024]
Abstract
Although the mobility of arsenic (As) and cadmium (Cd) in soils during the flooding-drainage process has been intensively studied, predicting their dissolution among various soils still remains a challenge. After comprehensively monitoring multiple parameters related to As and Cd dissolution in 8 soils for a 60-day anaerobic incubation, the redundancy analysis (RDA) and structural equation model (SEM) were employed to identify the key factors and influencing pathways controlling the dynamic release of As and Cd. Results showed that pH alone explained 90.5 % Cd dissolution, while the dissolved-Fe(II) and 5 M-HCl extractable Fe(II) jointly only explained 50.6 % As dissolution. After data normalization, the ratio of Fe(II) to 5 M-HCl extracted total Fe (i.e. FetotII/Fetot) significantly improved the correlation to R2 = 0.824 (p < 0.001) with a fixed slope of 0.393 among the 8 soils. Our results highlight the crucial role played by the reduction degree of total iron contents in determining both the reduction and dissolution of As during flooding. In contrast, dissolved-Fe(II) was too vulnerable to soil properties to be a stable indicator of As dissolution. Therefore, we propose to replace the dissolved-Fe(II) with this novel ratio as the key index to quantitatively assess the kinetic change of As solubility potential across various soils under flooding conditions.
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Affiliation(s)
- Jingwen Ge
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, China
| | - Song Wu
- Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China.
| | - Haotian Wu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, China
| | - Jianyu Lin
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, China
| | - Yijun Cai
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, China
| | - Dongmei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, China
| | - Xueyuan Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, China.
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Yang H, Zhou J, Zhou J. Interactive effects of ammonium sulfate and lead on alfalfa in rare earth tailings: Physiological responses and toxicity thresholds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 947:174439. [PMID: 38971260 DOI: 10.1016/j.scitotenv.2024.174439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 06/26/2024] [Accepted: 06/30/2024] [Indexed: 07/08/2024]
Abstract
Ion-adsorption rare earth ore contains significant levels of leaching agents and heavy metals, leading to substantial co-contamination. This presents significant challenges for ecological rehabilitation, yet there is limited understanding of the toxicity thresholds associated with the co-contamination of ammonium sulfate (AS) and lead (Pb) on pioneer plants. Here, we investigated the toxicity thresholds of various aspects of alfalfa, including growth, ultrastructural changes, metabolism, antioxidant system response, and Pb accumulation. The results indicated that the co-contamination of AS-Pb decreased the dry weight of shoot and root by 26 %-77 % and 18 %-92 %, respectively, leading to irregular root cell morphology and nucleus disintegration. The high concentration and combined exposures to AS and Pb induced oxidative stress on alfalfa, which stimulated the defense of the antioxidative system and resulted in an increase in proline levels and a decrease in soluble sugars. Structural equation modeling analysis and integrated biomarker response elucidated that the soluble sugars, proline, and POD were the key physiological indicators of alfalfa under stresses and indicated that co-exposure induced more severe oxidative stress in alfalfa. The toxicity thresholds under single exposure were 496 (EC5), 566 (EC10), 719 (EC25), 940 (EC50) mg kg-1 for AS and 505 (EC5), 539 (EC10), 605 (EC25), 678 (EC50) mg kg-1 for Pb. This study showed that AS-Pb pollution notably influenced plant growth performance and had negative impacts on the growth processes, metabolite levels, and the antioxidant system in plants. Our findings contribute to a theoretical foundation and research necessity for evaluating ecological risks in mining areas and assessing the suitability of ecological restoration strategies.
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Affiliation(s)
- Huixian Yang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing Zhou
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Zhou
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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Gao P, Yan X, Xia X, Liu D, Guo S, Ma R, Lou Y, Yang Z, Wang H, Yang Q, Pan H, Zhuge Y. Effects of the three amendments on NH 3 volatilization, N 2O emissions, and nitrification at four salinity levels: An indoor experiment. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 354:120399. [PMID: 38387357 DOI: 10.1016/j.jenvman.2024.120399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/16/2024] [Accepted: 02/12/2024] [Indexed: 02/24/2024]
Abstract
The marked salinity and alkaline pH of coastal saline soil profoundly impact the nitrogen conversion process, leading to a significantly reduced nitrogen utilization efficiency and substantial gaseous nitrogen loss. The application of soil amendments (e.g. biochar, manure, and gypsum) was proved to be effective for the remediation of saline soils. However, the effects of the three amendments on soil nitrogen transformation in soils with various salinity levels, especially on NH3 volatilization and N2O emission, remain elusive. Here, we reported the effects of biochar, manure, and gypsum on NH3 volatilization and N2O emission under four natural salinity gradients in the Yellow River Delta. Also, high-throughput sequencing and qPCR analysis were performed to characterize the response of nitrification (amoA) and denitrification (nirS, nirK, and nosZ) functional genes to the three amendments. The results showed that the three amendments had little effect on NH3 volatilization in low- and moderate-salinity soils, while biochar stimulated NH3 volatilization in high-salinity soils and reduced NH3 volatilization in severe-salinity soils. Spearman correlation analysis demonstrated that AOA was significantly and positively correlated with the NO3--N content (r = 0.137, P < 0.05) and N2O emissions (r = 0.174, P < 0.01), which indicated that AOA dominated N2O emissions from nitrification in saline soils. Structural equation modeling indicated that biochar, manure, and gypsum affected N2O emission by influencing soil pH, conductivity, mineral nitrogen content, and functional genes (AOA-amoA and nosZ). Two-way ANOVA further showed that salinity and amendments (biochar, manure, and gypsum) had significant effects on N2O emissions. In summary, this study provides valuable insights to better understand the effects of gaseous N changes in saline soils, thereby improving the accuracy and validity of future GHG emission predictions and modeling.
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Affiliation(s)
- Panpan Gao
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China
| | - Xianghui Yan
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China
| | - Xuejing Xia
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China
| | - Dan Liu
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China
| | - Songnian Guo
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China
| | - Ronghui Ma
- Agricultural Technology Promotion Center of Shandong Province, Jinan, 252199, China
| | - Yanhong Lou
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China
| | - Zhongchen Yang
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China
| | - Hui Wang
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China
| | - Quangang Yang
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China
| | - Hong Pan
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China.
| | - Yuping Zhuge
- National Engineering Research Center for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Daizong Road, Tai'an, 271018, China.
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Gao Y, Jiang M, Luo Z, Lyu B, Yang Y, Liao J, Jia X, Chen Q. Sasa argenteostriata - A potential plant for phytostabilization remediation of lead-zinc tailing-contaminated soil. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 271:115969. [PMID: 38219621 DOI: 10.1016/j.ecoenv.2024.115969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/04/2024] [Accepted: 01/07/2024] [Indexed: 01/16/2024]
Abstract
Phytoremediation is an effective way to remediate metal-contaminated soils. During phytoremediation, plants immobilize heavy metals through the roots to reduce the mobility, toxicity and dispersal of the metals, and the changes in the activity of the roots are often accompanied by changes in the rhizosphere ecosystems, in which rhizobacteria are essential components and interact with roots to maintain the stability of the rhizosphere ecosystem and improve soil health. In this study, the phytoremediation potential of Sasa argenteostriata (Regel) E.G. Camu and the response of rhizobacteria were revealed with different levels of lead-zinc tailing contamination (Pb, Zn, and Cd concentrations of 1197.53, 3243.40, and 185.44 mg/kg for M1 and 2301.71, 6087.95, and 364.00 mg/kg for M2, respectively). The BCF of Sasa argenteostriata increased with increasing soil pollution, and the BCFPb, BCFZn, and BCFCd were 0.19, 0.27, and 0.08, respectively, under the M2 treatment; in contrast, the TF decreased with increasing soil pollution, and the TFPb, TFZn, and TFCd were 0.39, 0.85, and 0.07, respectively, under the M1 treatment. The mobility of Pb in the rhizosphere was higher than that of Zn and Cd, and the percentage of residual (Res) Zn and Cd in the rhizosphere increased, while the acid-soluble (Aci) Pb was significantly higher, leading to obvious uptake of Pb by the roots. Correlation analysis showed that Sasa argenteostriata affected the rhizobacterial community by changing the rhizosphere soil pH, the contents of organic matter and NRFM, and bacteria such as Proteobacteria and MND1, which are highly resistant to heavy metals (HMs), became the dominant species in the community. Further PICRUSt2 analysis showed that reducing metal transport across the membranes and increasing the efficiency of cellular reproduction were the main metabolic mechanisms of bacterial tolerance to HMs. Overall, the roots of Sasa argenteostriata were able to immobilize more heavy metals in PbZn tailing-contaminated soil, reducing the toxicity of HMs in the soil, and then influencing the rhizobacteria to change the community structure and metabolism mechanism to adapt to the HM-contaminated environment, and the soil fertility was increased, which together promoted the health and stability of the soil. This study is the first to illustrate the phytoremediation potential and response of the rhizobacterial community of Sasa argenteostriata under multimetal contamination of PbZn tailings. The results of the study provide some guidance for the practice of lead-zinc tailing-phytoremediation and soil health.
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Affiliation(s)
- Yedan Gao
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Mingyan Jiang
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.
| | - Zhenghua Luo
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Bingyang Lyu
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Yixiong Yang
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Jiarong Liao
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Xiaonuo Jia
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Qibing Chen
- College of Landscape Architecture, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
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