Manganese oxide application reduces cadmium bioavailability in rice rhizosphere: Insights from desorption kinetics and high-resolution imaging

IF 7.6 2区环境科学与生态学 Q1 ENVIRONMENTAL SCIENCES

Environmental Pollution Pub Date : 2025-03-22 DOI:10.1016/j.envpol.2025.126110

Chao Zhang , Xing-Yue Li , Dong-Xing Guan , Jia-Lu Gao , Qiong Yang , Xiao-Lei Chen , Lena Q. Ma

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引用次数: 0

Abstract

Cadmium (Cd) contamination in paddy soils threatens global food safety. While manganese (Mn)-based materials show promise in reducing soil Cd bioavailability, their efficacy requires further evaluation. Traditional ex situ sampling methods often overlook metal desorption kinetics and rhizosphere biochemical heterogeneity, potentially misinterpreting Mn's regulatory influence on Cd dynamics. This study employed in situ monitoring tools, including diffusive gradients in thin-films (DGT) measurements, DIFS (DGT-induced fluxes in soils) modeling, and high-resolution DGT and planar optode (PO) imaging, to assess the impact of two Mn oxides (MnO₂ and Mn₂O₃) on Cd bioavailability in rice rhizosphere. Application of MnO₂ and Mn₂O₃ reduced bioavailable Cd by 28.9 % and 15.3 %, respectively, attributed to elevated soil Mn and Fe levels fostering Cd immobilization. DGT-DIFS results revealed that Mn oxide application prolonged Cd replenishment time and reduced its desorption rate from soil solids. PO imaging identified pH heterogeneity in rice rhizosphere, confirming that Mn oxides mediated Cd bioavailability reduction by increasing pH. High-resolution DGT imaging revealed distinct spatial distribution patterns of Cd, Mn, and Fe fluxes, demonstrating Mn's inhibitory effects on Cd bioavailability. These findings highlight the potential of Mn oxides to mitigate Cd uptake by rice, offering a promising strategy for managing Cd-contaminated soils.

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来源期刊

Environmental Pollution 环境科学-环境科学

CiteScore

16.00

自引率

6.70%

发文量

2082

审稿时长

2.9 months

期刊介绍： Environmental Pollution is an international peer-reviewed journal that publishes high-quality research papers and review articles covering all aspects of environmental pollution and its impacts on ecosystems and human health. Subject areas include, but are not limited to: • Sources and occurrences of pollutants that are clearly defined and measured in environmental compartments, food and food-related items, and human bodies; • Interlinks between contaminant exposure and biological, ecological, and human health effects, including those of climate change; • Contaminants of emerging concerns (including but not limited to antibiotic resistant microorganisms or genes, microplastics/nanoplastics, electronic wastes, light, and noise) and/or their biological, ecological, or human health effects; • Laboratory and field studies on the remediation/mitigation of environmental pollution via new techniques and with clear links to biological, ecological, or human health effects; • Modeling of pollution processes, patterns, or trends that is of clear environmental and/or human health interest; • New techniques that measure and examine environmental occurrences, transport, behavior, and effects of pollutants within the environment or the laboratory, provided that they can be clearly used to address problems within regional or global environmental compartments.