Cadmium and zinc isotope compositions indicate metal sources and retention mechanisms in different soil particle size fractions.
Cadmium and zinc isotope compositions indicate metal sources and retention mechanisms in different soil particle size fractions.
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DOI：
10.1016/j.jhazmat.2023.132560
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发表时间：
2023-09
影响因子：
13.6
通讯作者：
Jiawen Zhou;Rebekah E. T. Moore;M. Rehkämper;K. Kreissig;Barry Coles;Longhua Wu;Yongming Luo;Peter Christie
中科院分区：
文献类型：
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作者：
Jiawen Zhou;Rebekah E. T. Moore;M. Rehkämper;K. Kreissig;Barry Coles;Longhua Wu;Yongming Luo;Peter Christie
土壤颗粒大小对金属元素的分布和稳定同位素行为有重要影响。在这里，将两种土壤分成四个粒径部分，即细砂、粉砂、细粉砂和胶体颗粒，并用于测定镉（Cd）和锌（Zn）浓度和同位素组成。Cd和Zn的浓度一般富集在较细的颗粒，并与铁（Fe）和锰（Mn）的氧化物含量呈正相关。而细砂中Cd的含量高于粉砂中Cd的含量，这是由于细砂中有机质含量较高所致。两种土壤胶体颗粒的δ114/110 Cd值最大（-0.02和0.01‰），粉粒最小（-0.12和0.06 ‰）。掺入矿物晶格的铁和锰氧化物的建议，以解释轻微富集重镉同位素的胶体部分。4种颗粒的δ 66 Zn值相近（0.20-0.29‰，平均0.25‰），表明不同粒径的Zn来源相似。不同土壤粒度组分的金属同位素指纹可以进一步了解土壤微区中金属的固持机制，并有助于追踪金属来源和地球化学过程。
Soil particle size may significantly affect metal distribution and stable isotopic behavior. Here, two soils were separated into four particle size fractions, namely fine sand, silt, fine silt, and colloidal particles and used to determine cadmium (Cd) and zinc (Zn) concentrations and isotope compositions. Concentrations of Cd and Zn were generally enriched in the finer particles and positively correlated with the iron (Fe) and manganese (Mn) oxide contents. However, Cd concentration in the fine sand was higher than in the silt fraction due to the higher soil organic matter contents in the former particle fraction. The maximum δ114/110Cd value was found in the colloidal particles (−0.02 and 0.01‰) of both soils while the minimum was in the silt particles (−0.12 and single bond0.06‰). Incorporation into the mineral lattice of Fe and Mn oxides is suggested to explain the slight enrichment of heavy Cd isotopes in the colloidal fraction. The similar δ66Zn values of the four particle fractions (0.20–0.29‰ with a mean of 0.25‰) indicate similar Zn sources in different particle sizes. Metal isotopic fingerprint of different soil particle size fractions provides further insight into the underlying metal retention mechanisms within soil micro-zones and helps in tracing metal sources and biogeochemical processes.