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Wu B, Li X, Lin S, Jiao R, Yang X, Shi A, Nie X, Lin Q, Qiu R. Miscanthus sp. root exudate alters rhizosphere microbial community to drive soil aggregation for heavy metal immobilization. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 949:175009. [PMID: 39053533 DOI: 10.1016/j.scitotenv.2024.175009] [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: 05/16/2024] [Revised: 07/18/2024] [Accepted: 07/22/2024] [Indexed: 07/27/2024]
Abstract
The heavy metals (HMs) spatial distribution in soil is intricately shaped by aggregation processes involving chemical reactions and biological activities, which modulate HMs toxicity, migration, and accumulation. Pioneer plants play a central role in preventing HMs at source, yet the precise mechanisms underlying their involvement in soil aggregation remain unclear. This study investigates HMs distribution within rhizosphere and bulk soil aggregates of Miscanthus sp. grown in tailings to elucidate the impact of root exudates (REs) and rhizosphere microbes. The results indicate that Miscanthus sp. enhance soil stability, increasing the proportion of macroaggregates by 4.06 %-9.78 %. HMs tend to concentrate in coarse-aggregates, particularly within rhizosphere environments, while diminishing in fine-aggregates. Under HMs stress, lipids and lipid-like molecules are the most abundant REs produced by Miscanthus sp., accounting for under up to 26.74 %. These REs form complex with HMs, promoting microaggregates formation. Charged components such as sugars and amino acids further contribute to soil aggregation. REs also regulates rhizosphere bacteria and fungi, with Acidobacteriota, Chloroflexi were the dominant bacterial phyla, while Ascomycota and Basidiomycota dominate the fungal community. The synergistic effect of REs and microorganisms impact soil organic matter and nutrient content, facilitating HMs nanoparticle heteroaggregation and macroaggregates formation. Consequently, soil structure and REs shape the distribution of HMs in soil aggregation. Pioneer plants mediate REs interaction with rhizosphere microbes, promoting the distribution of HMs into macroaggregates, leading to immobilization. This study sheds light on the role of pioneer plants in regulating soil HMs, offering valuable insights for soil remediation strategies.
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Affiliation(s)
- Bohan Wu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Xiao Li
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Shukun Lin
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Ruifang Jiao
- Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Guangzhou 510650, China
| | - Xu Yang
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Aoao Shi
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Xinxing Nie
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Qingqi Lin
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
| | - Rongliang Qiu
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China; School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China.
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Ammar A, Nouira A, El Mouridi Z, Boughribil S. Recent trends in the phytoremediation of radionuclide contamination of soil by cesium and strontium: Sources, mechanisms and methods: A comprehensive review. CHEMOSPHERE 2024; 359:142273. [PMID: 38750727 DOI: 10.1016/j.chemosphere.2024.142273] [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: 02/23/2024] [Revised: 05/03/2024] [Accepted: 05/05/2024] [Indexed: 05/19/2024]
Abstract
This comprehensive review examines recent trends in phytoremediation strategies to address soil radionuclide contamination by cesium (Cs) and strontium (Sr). Radionuclide contamination, resulting from natural processes and nuclear-related activities such as accidents and the operation of nuclear facilities, poses significant risks to the environment and human health. Cs and Sr, prominent radionuclides involved in nuclear accidents, exhibit chemical properties that contribute to their toxicity, including easy uptake, high solubility, and long half-lives. Phytoremediation is emerging as a promising and environmentally friendly approach to mitigate radionuclide contamination by exploiting the ability of plants to extract toxic elements from soil and water. This review focuses specifically on the removal of 90Sr and 137Cs, addressing their health risks and environmental implications. Understanding the mechanisms governing plant uptake of radionuclides is critical and is influenced by factors such as plant species, soil texture, and physicochemical properties. Phytoremediation not only addresses immediate contamination challenges but also provides long-term benefits for ecosystem restoration and sustainable development. By improving soil health, biodiversity, and ecosystem resilience, phytoremediation is in line with global sustainability goals and environmental protection initiatives. This review aims to provide insights into effective strategies for mitigating environmental hazards associated with radionuclide contamination and to highlight the importance of phytoremediation in environmental remediation efforts.
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Affiliation(s)
- Ayyoub Ammar
- Laboratory of Virology, Microbiology, Quality and Biotechnology /Eco-toxicology and Biodiversity (LVMQB/EB), Faculty of Sciences and Techniques Mohammedia, University Hassan II, Casablanca, Morocco; National Center for Energy, Sciences, and Nuclear Techniques (CNESTEN), Rabat, Morocco; Laboratory of Environment and Conservation of Natural Resources, National Institute of Agronomique Research (INRA), Rabat, Morocco.
| | - Asmae Nouira
- National Center for Energy, Sciences, and Nuclear Techniques (CNESTEN), Rabat, Morocco
| | - Zineb El Mouridi
- Laboratory of Environment and Conservation of Natural Resources, National Institute of Agronomique Research (INRA), Rabat, Morocco
| | - Said Boughribil
- Laboratory of Virology, Microbiology, Quality and Biotechnology /Eco-toxicology and Biodiversity (LVMQB/EB), Faculty of Sciences and Techniques Mohammedia, University Hassan II, Casablanca, Morocco
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3
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Luo Y, He Y, Zhou D, Pan L, Wu Y. Organic amendment application affects the release behaviour, bioavailability, and speciation of heavy metals in zinc smelting slag: Insight into dissolved organic matter. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133105. [PMID: 38056253 DOI: 10.1016/j.jhazmat.2023.133105] [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: 09/13/2023] [Revised: 11/12/2023] [Accepted: 11/26/2023] [Indexed: 12/08/2023]
Abstract
Organic amendments are commonly used in assisted phytostabilization of mine wastes by improving their physicochemical and biological properties. These amendments are susceptible to leaching and degradation, resulting in the generation of dissolved organic matter (DOM), which significantly influences the geochemical behaviour of heavy metals (HMs). However, the geochemical behaviour of HMs in metal smelting slag driven by organic amendment-derived DOM remains unclear. In this study, we investigated the impact of cow manure-derived DOM on the release behaviour, bioavailability, and speciation of HMs (Cu, Pb, Zn, and Cd) in zinc smelting slag using a multidisciplinary approach. The results showed that DOM enhanced the weathering of the slag, with a minimal impact on the slag's mineral phases, except for causing gypsum dissolution. The DOM addition resulted in a slight increase in HM release from the slag during the initial inoculation period, followed by a reduction in HM release during the later period. Furthermore, the DOM addition increased the diversity and relative abundance of the bacterial community. This, in turn, led to a decrease in the dissolved organic carbon (DOC) content and enhanced the transformation of labile DOM compounds into recalcitrant compounds. The variation in HM release during various inoculation periods can be attributed to the bacterial decomposition and transformation of DOM, which further enhanced the transformation of HM fractions. Specifically, during the later period, DOM promoted the conversion of a portion of the reducible and oxidizable fractions of Cu, Pb, and Zn into the acid-soluble and residual fractions. Moreover, it partially transformed the reducible, oxidizable, and residual fractions of Cd into the acid-soluble fraction. Overall, this study provides new insights into the geochemical behaviour of HMs in slag governed by the coupling effect of DOM and the bacterial community. These findings have implications for the use of organic amendments in assisted phytostabilization of metal smelting slag. ENVIRONMENTAL IMPLICATION: Metal smelting slag is hazardous due to its high levels of HMs, and its improper disposal has serious consequences for the ecosystem. Organic amendments are employed in assisted phytostabilization of the slag site by improving its microecological properties. However, the impact of organic amendment-derived DOM on HM migration and transformation in slag remains unclear. This study indicated that the coupling effects of DOM and microbes governed the geochemical behaviour of HMs in slag. These findings provide new insights into how organic amendments impact the geochemical behaviour of HMs in slag, contributing to the development of phytostabilization technology.
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Affiliation(s)
- Youfa Luo
- Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou, University, Guiyang 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang 550025, China.
| | - Yu He
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Dongran Zhou
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Lishan Pan
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Yonggui Wu
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou, University, Guiyang 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang 550025, China
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4
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Yin F, Li J, Wang Y, Yang Z. Biodegradable chelating agents for enhancing phytoremediation: Mechanisms, market feasibility, and future studies. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 272:116113. [PMID: 38364761 DOI: 10.1016/j.ecoenv.2024.116113] [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: 08/25/2023] [Revised: 02/08/2024] [Accepted: 02/11/2024] [Indexed: 02/18/2024]
Abstract
Heavy metals in soil significantly threaten human health, and their remediation is essential. Among the various techniques used, phytoremediation is one of the safest, most innovative, and effective. In recent years, the use of biodegradable chelators to assist plants in improving their remediation efficiency has gained popularity. These biodegradable chelators aid in the transformation of metal ions or metalloids, thereby facilitating their mobilization and uptake by plants. Developed countries are increasingly adopting biodegradable chelators for phytoremediation, with a growing emphasis on green manufacturing and technological innovation in the chelating agent market. Therefore, it is crucial to gain a comprehensive understanding of the mechanisms and market prospects of biodegradable chelators for phytoremediation. This review focuses on elucidating the uptake, translocation, and detoxification mechanisms of chelators in plants. In this study, we focused on the effects of biodegradable chelators on the growth and environmental development of plants treated with phytoremediation agents. Finally, the potential risks associated with biodegradable chelator-assisted phytoremediation are presented in terms of their availability and application prospects in the market. This study provides a valuable reference for future research in this field.
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Affiliation(s)
- Fengwei Yin
- School of Life Sciences, Taizhou University, Taizhou 318000, People's Republic of China
| | - Jianbin Li
- Jiaojiang Branch of Taizhou Municipal Ecology and Environment Bureau, Taizhou 318000, People's Republic of China
| | - Yilu Wang
- School of Life Sciences, Taizhou University, Taizhou 318000, People's Republic of China; Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China
| | - Zhongyi Yang
- School of Life Sciences, Taizhou University, Taizhou 318000, People's Republic of China.
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5
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Li X, Li R, Zhan M, Hou Q, Zhang H, Wu G, Ding L, Lv X, Xu Y. Combined magnetic biochar and ryegrass enhanced the remediation effect of soils contaminated with multiple heavy metals. ENVIRONMENT INTERNATIONAL 2024; 185:108498. [PMID: 38402711 DOI: 10.1016/j.envint.2024.108498] [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: 11/10/2023] [Revised: 02/09/2024] [Accepted: 02/10/2024] [Indexed: 02/27/2024]
Abstract
Biochar is a very promising material for soil remediation. However, most studies mainly focus on the adsorption ability of biochar on one heavy metal, which is difficult to evaluate the actual remediation effect since soils were contaminated with multiple heavy metals. In order to improve the soil remediation efficiency, we used the joint remediation method of magnetically modified biochar and ryegrass to remediate the soil polluted by compound heavy metals (chromium, nickel, copper, zinc, arsenic and cadmium), and evaluate the effect on the process of organic carbon mineralization in polluted soils. It was found that magnetic biochar and ryegrass together decreased the concentrations of Cr, Ni, Cu, Zn, As, and Cd in soils by 24.12 %, 23.30 %, 22.01 %, 9.98 %, 14.83 %, and 15.08 %, respectively, and reduced the available fractions. Ryegrass roots were the main accumulation part of heavy metals, and the order of enrichment effect was ranked as Zn > As > Cr > Cu > Ni > Cd. In addition, magnetic biochar can maintained the stability of the organic carbon pool, and inhibited the emission of volatile organic compounds from ryegrass. Overall, this study indicates that magnetic biochar spheres combined with ryegrass is an effective method for heavy metals co-contaminated soils, and has the excellent remediation ability for actual co-contaminated soils.
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Affiliation(s)
- Xuening Li
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao 266071, China
| | - Ruipu Li
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao 266071, China
| | - Mengqi Zhan
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao 266071, China
| | - Qian Hou
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao 266071, China
| | - Haoyu Zhang
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao 266071, China
| | - Guangqi Wu
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao 266071, China
| | - Liqun Ding
- Marine Chemical Research Institute Co., LTD, Qingdao 266071, China
| | - Xiaofei Lv
- Department of Environmental Engineering, China Jiliang University, Hangzhou 310018, China
| | - Yan Xu
- College of Environmental Sciences and Engineering, Qingdao University, Qingdao 266071, China.
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6
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Qiu J, De Souza MF, Wang X, Ok YS, Meers E. Influence of biochar addition and plant management (cutting and time) on ryegrass growth and migration of As and Pb during phytostabilization. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 913:169771. [PMID: 38176551 DOI: 10.1016/j.scitotenv.2023.169771] [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: 09/22/2023] [Revised: 12/21/2023] [Accepted: 12/28/2023] [Indexed: 01/06/2024]
Abstract
Phytostabilization of metal-contaminated soils can be enabled or improved by biochar application. However, biochar-aided effects vary on biochar types, and little attention has been paid to plant management (time and cutting) to enhance phytostabilization efficiency in synergy with biochar. Therefore, biochars derived from pig manure (PM), Japanese knotweed (JK), and a mixture of both (P1J1) were applied to Pb and As mining soil with ryegrass cultivation to assess the biochar-induced effects on plant growth, dissolved organic matter (DOM), As and Pb mobility, and bioaccumulation within a phytostabilization strategy. Additional treatments involving the combined biochar (P1J1) and ryegrass were conducted to explore the influence of sequential cutting and growing time on facilitating phytostabilization efficacy. Biochar applications promoted plant growth, progressively increasing over time, but were not enhanced by cutting. Short and long-wavelength humic-like DOM substances identified in the soil pore water after biochar application varied depending on the biochar types used, providing evidence for the correlation among DOM changes, biochar origin, and metal immobilization. Biochar-treated soils exhibited reduced Pb availability and enhanced As mobility, with P1J1 stabilizing Pb significantly similar to PM while causing less As mobilization as JK did. The mobilized As did not result in increased plant As uptake; instead, all biochar-added plants showed a significant decrease in As and Pb concentrations compared to those without biochar. Soil available As decreased while available Pb increased with time, and cutting did not influence soil As behavior but did reduce soil Pb release. Nevertheless, plant As and Pb concentrations decreased over time, whereas those in multiple-cut plants were generally higher than those without cuts. Biochar, especially P1J1, along with growth time, holds promise in promoting plant biomass, reducing plant Pb and As concentrations, and minimizing the migration of PbAs within the soil.
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Affiliation(s)
- Jing Qiu
- Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium.
| | - Marcella Fernandes De Souza
- Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
| | - Xiaolin Wang
- Future Energy Center, School of Business, Society and Engineering, Mälardalen University, 722 23 Västerås, Sweden
| | - Yong Sik Ok
- Korea Biochar Research Center, APRU Sustainable Waste Management Program & Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Erik Meers
- Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium
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Zhang B, Sun Q, Chen Z, Shu F, Chen J. Evaluation of zinc tolerance and accumulation in eight cultivars of bermudagrass (Cynodon spp.): implications for zinc phytoremediation. Biometals 2023; 36:1377-1390. [PMID: 37530928 DOI: 10.1007/s10534-023-00524-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 07/24/2023] [Indexed: 08/03/2023]
Abstract
Zinc (Zn) is a vital element for plant growth and development, however, excessive Zn is toxic to plants. Common bermudagrass (Cynodon dactylon (L.) Pers.) and hybrid bermudagrass (C. dactylon (L.) Pers. × C. transvaalensis Burtt-Davy) are widely used turfgrass species with strong tolerance to diverse abiotic stresses, including excessive Zn2+ stress. However, the variation of zinc tolerance and accumulation in different bermudagrass cultivars remain unclear. In this study, we systematically analyzed the growth performance, physiological index and ion concentration in eight commercial cultivars of common and hybrid bermudagrass under different concentration of Zn2+ treatments using pot experiments. The results indicated that four cultivars of common bermudagrass could tolerate 20 mM Zn2+, whereas four cultivars of hybrid bermudagrass could only tolerate 10 mM Zn2+. Among the four common bermudagrass cultivars, cultivar Guanzhong and Common showed stronger Zn tolerance and accumulation abilities than other two cultivars. Further analyses of the expression of selected Zn homeostasis-related genes indicated that bermudagrass cultivars with stronger tolerance to excessive Zn have at least one expression-elevated gene involved in Zn homeostasis. These results not only expanded our understanding of Zn tolerance and accumulation in bermudagrass but also facilitated the application of commercial bermudagrass cultivars in phytoremediation of Zn pollution.
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Affiliation(s)
- Bing Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China.
| | - Qixue Sun
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Zhuoting Chen
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Fangzhi Shu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Jingbo Chen
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, 210014, China
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Luo Y, Xing R, Wu Y. Effect of simulated root exudates on the distribution, bioavailability, and fractionation of potentially toxic elements (PTEs) in various particle size fractions of zinc smelting slag: Implication of direct revegetation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 344:118642. [PMID: 37480634 DOI: 10.1016/j.jenvman.2023.118642] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 07/09/2023] [Accepted: 07/15/2023] [Indexed: 07/24/2023]
Abstract
Direct revegetation is a promising strategy for phytostabilization of metal smelting slag sites. Slag comes into direct contact with root exudates when slag sites undergo direct revegetation. The slag particle size fractions are considered the key factor influencing the geochemical behaviour of potentially toxic elements (PTEs). However, the effects of root exudates on the geochemical behaviours of PTEs in various slag particle size fractions remain unclear. Here, the effects of simulated root exudates of perennial ryegrass (Lolium perenne) directly revegetated at a zinc smelting slag site on the distribution, bioavailability, and fractionation of PTEs (Cu, Pb, Zn, and Cd) in various slag particle size fractions were investigated. The results showed that PTEs mainly occurred in the <1 mm slag particles; the mass loads of PTEs in the <1 mm slag particles were higher than those in the >1 mm slag particles. The bioavailability of Cu, Zn, and Cd rather than Pb in the slag increased as the particle size decreased. There was a decrease in the <0.25 and 1-2 mm slag particles and an increase in the 0.25-0.5, 0.5-1, and >2 mm slag particles in the presence of root exudates. Root exudates enhanced the transformation of acid-soluble PTEs into other more stable fractions in various slag particle size fractions. Root exudates enhanced the aggregation of slag particles associated with the migration of PTEs, causing differences in the geochemical behaviour of PTEs in various slag particle size fractions. These findings are beneficial for understanding the geochemical behaviour of PTEs in metal smelting slags undergoing direct revegetation and provide an important basis for the guidance of environmental risk management of the revegetated metal smelting slag sites.
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Affiliation(s)
- Youfa Luo
- Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang, 550025, China.
| | - Rongrong Xing
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Yonggui Wu
- College of Resource and Environmental Engineering, Guizhou University, Guiyang, 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guiyang, 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang, 550025, China.
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9
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He Y, Luo Y, Wei C, Long L, Wang C, Wu Y. Effects of dissolved organic matter derived from cow manure on heavy metal(loid)s and bacterial community dynamics in mercury-thallium mining waste slag. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:5857-5877. [PMID: 37178440 DOI: 10.1007/s10653-023-01607-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 05/04/2023] [Indexed: 05/15/2023]
Abstract
Organic amendments in aided phytostabilization of waste slag containing high levels of heavy metal (loid)s (HMs) are an important way to control the release of HMs in situ. However, the effects of dissolved organic matter (DOM) derived from organic amendments on HMs and microbial community dynamics in waste slag are still unclear. Here, the effect of DOM derived from organic amendments (cow manure) on the geochemical behaviour of HMs and the bacterial community dynamics in mercury (Hg)-thallium (Tl) mining waste slag were investigated. The results showed that the Hg-Tl mining waste slag without the addition of DOM continuously decreased the pH and increased the EC, Eh, SO42-, Hg, and Tl levels in the leachate with increasing incubation time. The addition of DOM significantly increased the pH, EC, SO42-, and arsenic (As) levels but decreased the Eh, Hg, and Tl levels. The addition of DOM significantly increased the diversity and richness of the bacterial community. The dominant bacterial phyla (Proteobacteria, Firmicutes, Acidobacteriota, Actinobacteriota, and Bacteroidota) and genera (Bacillus, Acinetobacter, Delftia, Sphingomonas, and Enterobacter) were changed in association with increases in DOM content and incubation time. The DOM components in the leachate were humic-like substances (C1 and C2), and the DOC content and maximum fluorescence intensity (FMax) values of C1 and C2 in the leachate decreased and first increased and then decreased with increasing incubation time. The correlations between HMs and DOM and the bacterial community showed that the geochemical behaviours of HMs in Hg-Tl mining waste slag were directly influenced by DOM-mediated properties and indirectly influenced by DOM regulation of bacterial community changes. Overall, these results indicated that DOM properties associated with bacterial community changes increased As mobilization but decreased Hg and Tl mobilization from Hg-Tl mining waste slag.
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Affiliation(s)
- Yu He
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Youfa Luo
- Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang, 550025, China.
- Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang, 550025, China.
- Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang, 550025, China.
| | - Chaoxiao Wei
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Licui Long
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Chi Wang
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
| | - Yonggui Wu
- College of Resources and Environmental Engineering, Guizhou University, Guiyang, 550025, China
- Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang, 550025, China
- Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang, 550025, China
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Luo Y, Xing R, Wan Z, Chen Y. Vertical distribution of nutrients, enzyme activities, microbial properties, and heavy metals in zinc smelting slag site revegetated with two herb species: Implications for direct revegetation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 879:163206. [PMID: 37011682 DOI: 10.1016/j.scitotenv.2023.163206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 05/17/2023]
Abstract
Direct revegetation is an important measure to immobilize heavy metals and improve the microecological properties of metal smelting slag sites. However, the vertical distribution of nutrients, microecological properties, and heavy metals at a directly revegetated metal smelting slag site remains unclear. Here, the distribution characteristics of nutrients, enzyme activities, microbial properties, and heavy metals in the vertical profile at a zinc smelting slag site directly revegetated with two herb species (Lolium perenne and Trifolium repens) for 5 years were investigated. The results showed that the nutrient contents, enzyme activities, and microbial properties decreased with increasing slag depth after revegetation with the two herb species. The nutrient contents, enzyme activities, and microbial properties of the surface slag revegetated with Trifolium repens were better than those in the surface slag revegetated with Lolium perenne. The higher root activity in the surface slag (0-30 cm) resulted in relatively higher contents of pseudo-total and available heavy metals in the surface slag. Moreover, the contents of pseudo-total heavy metals (except for Zn) and available heavy metals in the slag revegetated with Trifolium repens were lower than those in the slag revegetated with Lolium perenne at most slag depths. Overall, the greater phytoremediation efficiency of the two herb species occurred mainly in the surface slag (0-30 cm), and the phytoremediation efficiency of Trifolium repens was higher than that of Lolium perenne. The findings are beneficial for understanding the phytoremediation efficiency of direct revegetation strategies for metal smelting slag sites.
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Affiliation(s)
- Youfa Luo
- Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Karst Environmental Ecosystems Observation and Research Station, Ministry of Education, Guizhou University, Guiyang 550025, China; Guizhou Hostile Environment Ecological Restoration Technology Engineering Research Centre, Guizhou University, Guiyang 550025, China.
| | - Rongrong Xing
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Zuyan Wan
- College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China
| | - Yulu Chen
- Key Laboratory of Kast Georesources and Environment, Ministry of Education, Guizhou University, Guiyang 550025, China
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Zeng J, Ke W, Deng M, Tan J, Li C, Cheng Y, Xue S. A practical method for identifying key factors in the distribution and formation of heavy metal pollution at a smelting site. J Environ Sci (China) 2023; 127:552-563. [PMID: 36522085 DOI: 10.1016/j.jes.2022.06.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/20/2022] [Accepted: 06/20/2022] [Indexed: 06/17/2023]
Abstract
Smelting activities are the main pathway for the anthropogenic release of heavy metals (HMs) into the soil-groundwater environment. It is vital to identify the factors affecting HMs pollution to better prevent and manage soil pollution. The present study conducted a comprehensive investigation of HMs in soil from a large abandoned Zn smelting site. An integrated approach was proposed to classify and quantify the factors affecting HMs pollution in the site. Besides, the quantitative relationship between hydrogeological characteristics, pollution transmission pathways, smelting activities and HMs pollution was established. Results showed that the soils were highly contaminated by HMs with a pollution index trend of As > Zn > Cd > Pb > Hg. In identifying the pollution hotspots, we conclude that the pollution hotspots of Pb, As, Cd, and Hg present a concentrated distribution pattern. Geo-detector method results showed that the dominant driving factors for HMs distribution and accumulation were the potential pollution source and soil permeability. Additionally, the main drivers are variable for different HMs, and the interaction among factors also enhanced soil HMs contamination. Our analysis illustrates how the confounding influences from complex environmental factors can be distilled to identify key factors in pollution formation to guide future remediation strategies.
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Affiliation(s)
- Jiaqing Zeng
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Wenshun Ke
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Min Deng
- School of Geosciences and Info-physics, Central South University, Changsha 410083, China
| | - Jingqiang Tan
- School of Geosciences and Info-physics, Central South University, Changsha 410083, China
| | - Chuxuan Li
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Yizhi Cheng
- New World Environment Protection Group of Hunan, Changsha 410083, China
| | - Shengguo Xue
- School of Metallurgy and Environment, Central South University, Changsha 410083, China.
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Proto M, Newsome L, Jensen E, Courtney R. Geochemical analyses of metal(loid) fractions do not predict plant uptake behavior: Are plant bioassays better tools to predict mine rehabilitation success? THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 861:160679. [PMID: 36481156 DOI: 10.1016/j.scitotenv.2022.160679] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/28/2022] [Accepted: 11/30/2022] [Indexed: 06/17/2023]
Abstract
Management of metal(loid) tailings at historic sites presents environmental hazards usually requiring rehabilitation to mitigate pollution risks. Strategies employed include capping or establishing vegetation directly, which requires tailings assessments to determine suitable rehabilitation approaches. Assessments are typically geochemical analyses, but plant based approaches may provide a more accurate measure of revegetation success although they are often limited to germination indices. This study uses the plant bioassay (Rhizotest™) with common geochemical assessment to predict plant uptake of metal(loid)s and the subsequent likely rehabilitation success. Pb/Zn tailings from five legacy sites within the UK and Ireland were characterized for pH, EC, water soluble and CaCl2-extractable content and aqua regia extractable content. Uptake of Sb, As, Cd, Cu, Ca, Mg, Mn, Zn, Pb was determined in shoots and roots of Lolium perenne. Total Zn, Pb, Sb, Cd and As in tailings ranged from 694 to 2683 mg kg-1, 1252 to 8072 mg kg-1, 14 to 148 mg kg-1, 1.3 to 44 mg kg-1 and 1.3 to 45 mg kg-1, respectively. The only correlation found between total and water soluble or CaCl2-extractable metal(loid) contents was for Cd, where r = 0.8 for total and CaCl2-extractable fractions. Limited uptake and translocation risk was identified for major contaminants Zn and Pb in most tailings samples but in some cases exceedance of phytotoxic threshold values occurred that was not reflected in geochemical analysis. Crucially, although total Cd and Sb content was relatively low (< 20 mg kg-1) in some tailings, elevated plant content for some samples highlights phytotoxic risk from minor elements. Results indicate that screening based on geochemical content is not sufficiently predictive of metal(loid) phytoavailability to reliably inform mine rehabilitation strategies. We therefore strongly recommend that geochemical analyses are supplemented with plant based bioassay to plan mine tailings revegetation and reduce risk of wider ecosystem metal(loid) transfer.
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Affiliation(s)
- M Proto
- Department of Biological Sciences and Bernal Institute, University of Limerick, Ireland
| | - L Newsome
- Camborne School of Mines, University of Exeter, United Kingdom of Great Britain and Northern Ireland
| | - E Jensen
- Aberystwyth University, United Kingdom of Great Britain and Northern Ireland
| | - R Courtney
- Department of Biological Sciences and Bernal Institute, University of Limerick, Ireland.
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Luyckx M, Hausman JF, Guerriero G, Lutts S. Silicon reduces zinc absorption and triggers oxidative tolerance processes without impacting growth in young plants of hemp (Cannabis sativa L.). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:943-955. [PMID: 35907072 DOI: 10.1007/s11356-022-21797-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/28/2022] [Indexed: 06/15/2023]
Abstract
Hemp (Cannabis sativa L.) is a promising crop for non-food agricultural production on soils contaminated by moderate doses of heavy metals, while silicon, as a beneficial element, is frequently reported to improve stressed plant behavior. Using a hydroponic system, plants of Cannabis sativa (cv. Santhica 27) were exposed for 1 week to 100 µM Zn in the presence or absence of 2 mM Si. Zinc accumulated in all plant organs but was mainly sequestered in the roots. Additional Si reduced Zn absorption but had no impact on Zn translocation. Zn accumulation had a slight negative impact on leaf number, stem length, and chlorophyll content, and additional Si did not mitigate these symptoms. Exogenous Si reduced the Zn-induced membrane lipid peroxidation (assessed by malondialdehyde quantification) and increased the total antioxidant activities estimated by the FRAP index. In the absence of Si, leaf phytochelatin and total glutathione were the highest in Zn-treated plants and Si significantly decreased their concentrations.
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Affiliation(s)
- Marie Luyckx
- Groupe de Recherche en Physiologie végétale, Earth and Life Institute - Agronomy (ELIA), Université Catholique de Louvain, 5 (Bte13) Place Croix du Sud, 1348, Louvain-la-Neuve, Belgium.
| | - Jean-François Hausman
- Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 5 Avenue des Hauts-Fourneaux, 4362, Esch/Alzette, Luxembourg
| | - Gea Guerriero
- Environmental Research and Innovation (ERIN) Department, Luxembourg Institute of Science and Technology (LIST), 5 Avenue des Hauts-Fourneaux, 4362, Esch/Alzette, Luxembourg
| | - Stanley Lutts
- Groupe de Recherche en Physiologie végétale, Earth and Life Institute - Agronomy (ELIA), Université Catholique de Louvain, 5 (Bte13) Place Croix du Sud, 1348, Louvain-la-Neuve, Belgium
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Rashid MS, Liu G, Yousaf B, Hamid Y, Rehman A, Arif M, Ahmed R, Ashraf A, Song Y. A critical review on biochar-assisted free radicals mediated redox reactions influencing transformation of potentially toxic metals: Occurrence, formation, and environmental applications. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 315:120335. [PMID: 36202269 DOI: 10.1016/j.envpol.2022.120335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
Potentially toxic metals have become a viable threat to the ecosystem due to their carcinogenic nature. Biochar has gained substantial interest due to its redox-mediated processes and redox-active metals. Biochar has the capacity to directly adsorb the pollutants from contaminated environments through several mechanisms such as coprecipitation, complexation, ion exchange, and electrostatic interaction. Biochar's electron-mediating potential may be influenced by the cyclic transition of surface moieties and conjugated carbon structures. Thus, pyrolysis configuration, biomass material, retention time, oxygen flow, and heating time also affect biochar's redox properties. Generally, reactive oxygen species (ROS) exist as free radicals (FRs) in radical and non-radical forms, i.e., hydroxyl radical, superoxide, nitric oxide, hydrogen peroxide, and singlet oxygen. Heavy metals are involved in the production of FRs during redox-mediated reactions, which may contribute to ROS formation. This review aims to critically evaluate the redox-mediated characteristics of biochar produced from various biomass feedstocks under different pyrolysis conditions. In addition, we assessed the impact of biochar-assisted FRs redox-mediated processes on heavy metal immobilization and mobility. We also revealed new insights into the function of FRs in biochar and its potential uses for environment-friendly remediation and reducing the dependency on fossil-based materials, utilizing local residual biomass as a raw material in terms of sustainability.
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Affiliation(s)
- Muhammad Saqib Rashid
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China
| | - Guijian Liu
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi, 710075, China.
| | - Balal Yousaf
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi, 710075, China
| | - Yasir Hamid
- Ministry of Education (MOE) Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Abdul Rehman
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China
| | - Muhammad Arif
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China; Department of Soil and Environmental Sciences, Muhammad Nawaz Shareef University of Agriculture, Multan, 60000, Pakistan
| | - Rafay Ahmed
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China
| | - Aniqa Ashraf
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China
| | - Yu Song
- CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China; School of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang, 621010, Sichuan, PR China
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