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Huang X, Zhu J, Li Q, Wei X, Yang Z, Yang W, Liao Q, Si M, Wang Q. Efficient mineralization of cadmium and arsenic by poorly crystalline CaFe-layered double hydroxide in soil: Performance and mechanism. ENVIRONMENTAL RESEARCH 2024; 262:119994. [PMID: 39276828 DOI: 10.1016/j.envres.2024.119994] [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: 07/02/2024] [Revised: 09/06/2024] [Accepted: 09/11/2024] [Indexed: 09/17/2024]
Abstract
The co-contamination of arsenic (As) and cadmium (Cd) in the environment is of most concern. In this work, poorly crystalline CaFe-layered double hydroxide (CaFe-LDH) was synthesized with a Ca-to-Fe molar ratio of 4 to ensure effective immobilization of Cd and As in soil. The application of Ca4Fe-LDH in soil remediation demonstrated that the targeted heavy metals gradually mineralized into a relatively stable oxidizable and residual state. At a soil remediation dosage of 1.6%, the availability levels of Cd and As decreased significantly, achieving stabilization efficiencies of 99% and 85.2% respectively. Cd is trapped through isomorphic substitution and dissolution-reprecipitation of calcium (Ca) laminate, resulting in the formation of CdCaFe-LDH mineralization products. As is immobilized through ion exchange with interlayer anions, redox with Fe(III), and Fe-Cd-As complexation. Moreover, the results of the characterization and density functional theoretical (DFT) calculations demonstrate that the CdCaFe-LDH formed by isomeric substitution of Ca for Cd enhanced the adsorption of As on the (110) plane of LDH, indicating that the trap mechanism of Cd and As by Ca4Fe-LDH is synergistically promoted. Overall, the above results prove that mineralization using Ca4Fe-LDH is a promising method to remediate soils combined contaminated by both Cd and As.
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Affiliation(s)
- Xiaofeng Huang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
| | - Jian Zhu
- Hunan Institute of Agri-Environment and Ecology, Changsha, 410125, China
| | - Qingzhu Li
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, 410083, China; State Key Laboratory of Advanced Metallurgy for Non-ferrous Metals, Changsha, 410083, China.
| | - Xiaohua Wei
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China
| | - Zhihui Yang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, 410083, China; State Key Laboratory of Advanced Metallurgy for Non-ferrous Metals, Changsha, 410083, China
| | - Weichun Yang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, 410083, China; State Key Laboratory of Advanced Metallurgy for Non-ferrous Metals, Changsha, 410083, China
| | - Qi Liao
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, 410083, China; State Key Laboratory of Advanced Metallurgy for Non-ferrous Metals, Changsha, 410083, China
| | - Mengying Si
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, 410083, China; State Key Laboratory of Advanced Metallurgy for Non-ferrous Metals, Changsha, 410083, China
| | - Qingwei Wang
- School of Metallurgy and Environment, Central South University, Changsha, 410083, China; National Engineering Research Centre for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, 410083, China; State Key Laboratory of Advanced Metallurgy for Non-ferrous Metals, Changsha, 410083, China
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Zhang Y, Tong D, Zou L, Ji H, Zhou X, Gustave W, Tang X. Low-molecular-weight organic acids inhibit the methane-dependent arsenate reduction process in paddy soils. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 282:116716. [PMID: 39018734 DOI: 10.1016/j.ecoenv.2024.116716] [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: 04/17/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/19/2024]
Abstract
Anaerobic methane oxidation (AOM) can drive soil arsenate reduction, a process known as methane-dependent arsenate reduction (M-AsR), which is a critical driver of arsenic (As) release in soil. Low molecular weight organic acids (LMWOAs), an important component of rice root exudates, have an unclear influence and mechanism on the M-AsR process. To narrow this knowledge gap, three typical LMWOAs-citric acid, oxalic acid, and acetic acid-were selected and added to As-contaminated paddy soils, followed by the injection of 13CH4 and incubation under anaerobic conditions. The results showed that LMWOAs inhibited the M-AsR process and reduced the As(III) concentration in soil porewater by 35.1-65.7 % after 14 days of incubation. Among the LMWOAs, acetic acid exhibited the strongest inhibition, followed by oxalic and citric acid. Moreover, LMWOAs significantly altered the concentrations of ferrous iron and dissolved organic carbon in the soil porewater, consequently impacting the release of As in the soil. The results of qPCR and sequencing analysis indicated that LMWOAs inhibited the M-AsR process by simultaneously suppressing microbes associated with ANME-2d and arrA. Our findings provide a theoretical basis for modulating the M-AsR process and enhance our understanding of the biogeochemical cycling of As in paddy soils under rhizosphere conditions.
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Affiliation(s)
- Yu Zhang
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, China
| | - Di Tong
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, China
| | - Lina Zou
- Zhejiang Institute of Landscape Plants and Flowers, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Haofeng Ji
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, China
| | - Xinyao Zhou
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, China
| | - Williamson Gustave
- School of Chemistry, Environmental & Life Sciences, University of the Bahamas, Nassau, New Providence, The Bahamas
| | - Xianjin Tang
- Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment, Zhejiang University, Hangzhou, China.
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Dong L, Hua Y, Gao Z, Wu H, Hou Y, Chu Y, Zhang J, Cui G. The Multiple Promoting Effects of Suaeda glauca Root Exudates on the Growth of Alfalfa under NaCl Stress. PLANTS (BASEL, SWITZERLAND) 2024; 13:752. [PMID: 38592745 PMCID: PMC10974879 DOI: 10.3390/plants13060752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 04/10/2024]
Abstract
Under abiotic stress, plant root exudates can improve plant growth performance. However, studies on the effect of root exudates on the stress resistance of another plant are insufficient. In this study, root exudates (REs) were extracted from Suaeda glauca to explore their effect on alfalfa seedlings under salt stress. The results showed that the plant height and fresh weight of alfalfa significantly increased by 47.72% and 53.39% after 7 days of RE treatment at a 0.4% NaCl concentration. Under 1.2% salt stress, REs reduced the Malondialdehyde content in alfalfa by 30.14% and increased the activity of its antioxidant enzymes (peroxidase and catalase) and the content of its osmotic regulators (soluble sugar and proline) by 60.68%, 52%, 45.67%, and 38.67%, respectively. Soil enzyme activity and the abundance of soil-beneficial bacteria were increased by REs. Spearman analysis showed that urease and neutral phosphatase were related to the richness of beneficial bacteria. Redundancy analysis confirmed that urease affected the composition of the soil bacterial community. The partial least squares structural equation model (PLS-SEM) revealed that REs had a direct positive effect on alfalfa growth under salt stress by regulating the plant's injury and antioxidant systems, and the soil bacterial community had an indirect positive effect on alfalfa growth through soil enzyme activity.
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Affiliation(s)
| | | | | | | | | | | | | | - Guowen Cui
- College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China; (L.D.); (Y.H.); (Z.G.); (H.W.); (Y.H.); (Y.C.); (J.Z.)
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