Purpose Understanding soil properties is essential for effective remediation planning and implementation under diverse environmental conditions. The objectives of this study were to evaluate how initial soil physicochemical properties influence changes after contamination with ZnCl₂ and CuCl₂ and to identify key properties that undergo the most significant changes. Materials and methods The chemical properties (Zn, Cu, Pb, Ni, chloride concentration Cl−, pHKCl,) and physical properties (specific surface area SSA (water sorption test method), SSAbm (methylene blue method), clay, silt, sand, the effective diameters: d10, d50, organic matter OM) of 42 different soil samples before and after contamination were studied. Metal concentrations were measured using Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and particle size distribution was analyzed by laser diffraction (LD). Factor analysis (FA) was used to determine which parameters change in response to contamination. Results Physicochemical properties of soils before contamination influence changes after ZnCl2 or CuCl2, leading to complex interactions. The FA showed significant variations in d10, d50, pH, and SSA in contaminated soils. In clays and silty clays (pH 6.7–7.6, d10 1.63–2.55 μm, d50 11.93–20.82 μm), contamination reduced d10, d50, and pH. Soils with SSA ≥ 138.2 m2/g (after ZnCl2) adsorb more Zn and Cl− but may release higher Zn in pH ≤ 6.42. Soils with SSA ~ 100 m2/g (pH 3.75–4.22) showed no significant physical changes after ZnCl2. For CuCl2, soils with SSA ≥ 114.5 m2/g retain Cu and Cl− better, while soils with SSA 86.8–105.7 m2/g may release more mobile Cu at pH = 7.55. Contamination increases Cu, Ni (after ZnCl2), and Zn, Ni (after CuCl2) concentrations, with Pb levels rising especially at pH ≥ 4, with the presence of OM (after CuCl2). Conclusion The initial properties of soils significantly influence their changes after contamination. Key factors include d10, d50, pH, and SSA. The reduction in d10 and d50 suggests that contaminants may form sediments or precipitate in soil pores, partially clogging them. Further research should assess the filtration coefficient, as it is directly influenced by changes in d10 and d50, which, in turn, affect soil permeability and flow dynamics. The soils most resistant to contamination seem to be with SSA ~ 100 m2/g (pH 3.75–4.22) (in ZnCl2) or with SSA ≥ 114.5 m2/g (in CuCl2). Secondary contaminants should be monitored, such as Cu and Ni (after ZnCl₂), Zn and Ni (after in CuCl₂), and Pb (after CuCl2 in the presence of OM).

Identification of factors affecting the properties of soils contaminated with Zn(II) and Cu(II) chlorides

期刊论文
发表日期：

2025年3月11日

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Edyta Nartowska,
Anna Podlasek,
Magdalena Daria Vaverková,
Eugeniusz Koda,
Maria Kanuchova,
Aleksandra Jakimiuk,
Jarosław Gawdzik

摘要

Purpose

Understanding soil properties is essential for effective remediation planning and implementation under diverse environmental conditions. The objectives of this study were to evaluate how initial soil physicochemical properties influence changes after contamination with ZnCl₂ and CuCl₂ and to identify key properties that undergo the most significant changes.

Materials and methods

The chemical properties (Zn, Cu, Pb, Ni, chloride concentration Cl⁻, pH_KCl,) and physical properties (specific surface area SSA (water sorption test method), SSA_bm (methylene blue method), clay, silt, sand, the effective diameters: d₁₀, d₅₀, organic matter OM) of 42 different soil samples before and after contamination were studied. Metal concentrations were measured using Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), and particle size distribution was analyzed by laser diffraction (LD). Factor analysis (FA) was used to determine which parameters change in response to contamination.

Results

Physicochemical properties of soils before contamination influence changes after ZnCl₂ or CuCl₂, leading to complex interactions. The FA showed significant variations in d₁₀, d₅₀, pH, and SSA in contaminated soils. In clays and silty clays (pH 6.7–7.6, d₁₀ 1.63–2.55 μm, d₅₀ 11.93–20.82 μm), contamination reduced d₁₀, d₅₀, and pH. Soils with SSA ≥ 138.2 m²/g (after ZnCl₂) adsorb more Zn and Cl⁻ but may release higher Zn in pH ≤ 6.42. Soils with SSA ~ 100 m²/g (pH 3.75–4.22) showed no significant physical changes after ZnCl₂. For CuCl₂, soils with SSA ≥ 114.5 m²/g retain Cu and Cl⁻ better, while soils with SSA 86.8–105.7 m²/g may release more mobile Cu at pH = 7.55. Contamination increases Cu, Ni (after ZnCl₂), and Zn, Ni (after CuCl₂) concentrations, with Pb levels rising especially at pH ≥ 4, with the presence of OM (after CuCl₂).

Conclusion

The initial properties of soils significantly influence their changes after contamination. Key factors include d₁₀, d₅₀, pH, and SSA. The reduction in d₁₀ and d₅₀ suggests that contaminants may form sediments or precipitate in soil pores, partially clogging them. Further research should assess the filtration coefficient, as it is directly influenced by changes in d₁₀ and d₅₀, which, in turn, affect soil permeability and flow dynamics. The soils most resistant to contamination seem to be with SSA ~ 100 m²/g (pH 3.75–4.22) (in ZnCl₂) or with SSA ≥ 114.5 m²/g (in CuCl₂). Secondary contaminants should be monitored, such as Cu and Ni (after ZnCl₂), Zn and Ni (after in CuCl₂), and Pb (after CuCl₂ in the presence of OM).