A semi-mechanistic aging model of Pb added to soil by a modified stable isotope dilution technique

Autor: Xuezhi Ji, Jumei Li, Shuo Sun, Ying Zhong, Yibing Ma
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Scientific Reports, Vol 14, Iss 1, Pp 1-13 (2024)
Druh dokumentu: article
ISSN: 2045-2322
DOI: 10.1038/s41598-024-69375-7
Popis: Abstract The aging of Pb added to soils has not been studied by the isotopic technology because of difficulties in determination of isotopically exchangeable Pb in soil, so that a set of 10 typical agricultural soils in China and a one-year aging experiment with the addition of water-soluble Pb to the soils were carried out. A modified stable isotope dilution technique to determine isotopically exchangeable Pb in soil was developed where 0.2 mM EDTA (ethylenediaminetetraacetic acid) as the extractant. When water-soluble Pb was added to soil, the isotopically exchangeable Pb (Eadd%, the percentage of isotopically exchangeable Pb to total Pb added to soil) initially decreased rapidly and gradually slowly. A semi-mechanistic aging model of Pb added to soils, including precipitation/nucleation (Y1), micropore diffusion (Y2), and organic matter encapsulation processes (Y3) was developed with the root mean square error 8.3% where Y1, Y2, and Y3 accounted for 0.02~26.9%, 1.4~21.8% and 3.8~11.3%, respectively, when the pH 4.0~8.0 and organic matter 2.0~6.0%. Soil pH was a vital factor affecting the aging rate. When the pH increased by 1 unit, the Eadd value decreased by approximately 9%. The model could be used to scale ecotoxicological data of Pb in soil generated in different aging times.
Databáze: Directory of Open Access Journals
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