TY - JOUR
T1 - Insight into the availability and desorption kinetics of Se and Cd in naturally-rich soils using diffusive gradients in thin-films technique
AU - Zhang, Chao
AU - Guan, Dong Xing
AU - Jiang, Yi Fan
AU - Menezes-Blackburn, Daniel
AU - Yu, Tao
AU - Yang, Zhongfang
AU - Ma, Lena Q.
N1 - Copyright © 2023 Elsevier B.V. All rights reserved.
PY - 2024/3/5
Y1 - 2024/3/5
N2 - Cadmium (Cd) contamination of selenium (Se)-rich soils may jeopardize the nutritional benefits of Se-biofortified crops. This study employed diffusive gradients in thin-films (DGT) technique and DIFS (DGT-induced fluxes in soils) model to understand the interdependency and driving factors of Se and Cd distribution and desorption kinetics across 50 soils from south China with naturally elevated levels. DGT-labile Se was the highest (up to 2.66 μg L−1) in non-carbonate/shale-derived soils, while Cd was maximal (5.53 μg L−1) in carbonate-based soils, reflecting soil background concentrations and soil characteristics. Over one-third of the soils showed labile Se:Cd molar ratio below 0.7, suggesting Cd phytotoxicity risks. The DIFS-derived response times (Tc) and desorption rate constants (k−1) suggested that Se was resupplied to the soil solution faster than Cd in soils with higher pH and SOM level, but Se resupply was still restricted due to the rapid depletion of its labile pool. As the first study of Se and Cd release kinetics in soils, our results reveal dependence on soil parent materials, with low labile Se:Cd soils presenting greater Cd hazards. By elucidating Se and Cd lability and interactions in soils, our findings help to inform management strategies to balance reduced Cd risk with adequate Se availability.
AB - Cadmium (Cd) contamination of selenium (Se)-rich soils may jeopardize the nutritional benefits of Se-biofortified crops. This study employed diffusive gradients in thin-films (DGT) technique and DIFS (DGT-induced fluxes in soils) model to understand the interdependency and driving factors of Se and Cd distribution and desorption kinetics across 50 soils from south China with naturally elevated levels. DGT-labile Se was the highest (up to 2.66 μg L−1) in non-carbonate/shale-derived soils, while Cd was maximal (5.53 μg L−1) in carbonate-based soils, reflecting soil background concentrations and soil characteristics. Over one-third of the soils showed labile Se:Cd molar ratio below 0.7, suggesting Cd phytotoxicity risks. The DIFS-derived response times (Tc) and desorption rate constants (k−1) suggested that Se was resupplied to the soil solution faster than Cd in soils with higher pH and SOM level, but Se resupply was still restricted due to the rapid depletion of its labile pool. As the first study of Se and Cd release kinetics in soils, our results reveal dependence on soil parent materials, with low labile Se:Cd soils presenting greater Cd hazards. By elucidating Se and Cd lability and interactions in soils, our findings help to inform management strategies to balance reduced Cd risk with adequate Se availability.
KW - Carbonate-based soils
KW - Cd phytotoxicity
KW - DIFS model
KW - Se:Cd molar ratio
KW - Shale-derived soils
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UR - https://www.mendeley.com/catalogue/8b95d211-7758-39b6-9e4c-0c34c63db866/
U2 - 10.1016/j.jhazmat.2023.133330
DO - 10.1016/j.jhazmat.2023.133330
M3 - Article
C2 - 38147757
AN - SCOPUS:85180549845
SN - 0304-3894
VL - 465
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
M1 - 133330
ER -