Urosevic et al. 2024 - Salix phytoremediation

Urosevic and colleagues tested three white willow clones and one basket willow genotype for heavy-metal uptake from Kolubara Mining Basin soil that was further enriched with heavy-metal salts. This is primary environmental phytoremediation evidence: it reports soil and willow root, stem, and leaf metal concentrations, but it does not measure edible crops, ingredients, food products, or dietary exposure.

Key numbers

Soil concentrations

Table 1 reports total heavy-metal concentrations in soil as mg/kg, with n = 6 repetitions per soil condition. The contaminated field soil was additionally spiked during the plant experiment because only Ni exceeded the Serbian maximum limit value before spiking.

The authors compared the contaminated-soil Ni mean of 37.60 mg/kg with Serbia’s Ni maximum limit value of 35 mg/kg and remediation value of 210 mg/kg. They reported significant contaminated-versus-control differences for Ni, Cd, Cr, Pb, and As, but not Cu.

Contaminating salt solution

At the beginning of each growing season, the contaminated substrate was watered to optimal water capacity with a 10^-3 mol/dm3 aqueous salt solution containing Cd(NO3)2 at 112.4 ppm, CuSO4.5H2O at 63.5 ppm, K2Cr2O7 at 104.0 ppm, Na2HAsO4.7H2O at 74.9 ppm, NiCl2.6H2O at 58.7 ppm, and PbNO3 at 207.2 ppm.

Plant tissue concentrations by organ

Table 2 reports total metal concentrations in willow roots, stems, and leaves as mg/kg. Mean values are shown here because the table also reports ranges, standard deviations, coefficients of variation, F ratios, and p values.

The largest contaminated-versus-control separations were reported for Ni in roots, Cu in roots, stems, and leaves, Cd in leaves, and Pb in roots. Root tissue had the highest mean Ni and Pb accumulation, Cu appeared across organs, and Cd was highest in leaves.

Genotype-level accumulation

Table 3 summarizes plant-material concentrations by genotype and treatment. Contaminated-material mean ranges across the four genotypes were 6.68-10.72 mg/kg for Ni, 19.68-24.47 mg/kg for Cu, 2.84-5.38 mg/kg for Cd, 2.17-4.28 mg/kg for Cr, 1.96-2.25 mg/kg for Pb, and 1.79-3.77 mg/kg for As. Control-material genotype means ranged from 1.07-1.59 mg/kg for Ni, 6.00-6.19 mg/kg for Cu, 0.63-0.73 mg/kg for Cd, 1.17-2.76 mg/kg for Cr, 0.00-0.38 mg/kg for Pb, and 0.00 mg/kg for As.

The authors report significant genotype effects for Cd and Cr in contaminated plant material and Cr in control plant material. Clone 347 had the greatest Cd and Cr accumulation, B-44 also accumulated Cd and Cr, and NS 73/6 showed a less pronounced Cr uptake.

Methods (brief)

About 5 tons of contaminated soil were excavated from the Kanal Crnih voda site in Serbia’s Kolubara Mining Basin, homogenized, and packed into 480 polyethylene bags for the contaminated-substrate experiment. The four willow genotypes were one basket willow genotype and three white willow clones: B-44, NS 73/6, and 347. Cuttings were soaked in fungicide [Cu2(OH)3Cl] before planting, which is a methodological confounder for the reported Cu accumulation in willow tissues because the pre-treatment introduces Cu to the cuttings independent of soil uptake. Cuttings were planted in March 2019, and root, stem, and leaf samples were taken at the end of the 2021 growing season.

Soils were air-dried, ground, sieved, and digested with aqua regia in a Milestone ETHOS EASY microwave digestion platform. Plant materials were dried at 40 degrees C, ground, digested with concentrated nitric acid and hydrogen peroxide, and brought to 25 mL. Soil and plant metals were measured in repeated determinations (n = 6 per soil condition and per organ/clone) using a VISTA-PRO ICP-OES system. The reported analytes are total elemental concentrations after digestion, not arsenic, chromium, or mercury species. Statistical analysis used ANOVA with Fisher’s LSD post hoc test and canonical discriminant analysis in Statgraphics Centurion ver. XVI.I.

Implications

Certification: Do not use this source in HMTc food-product occurrence pools. It is a phytoremediation and contaminated-soil study with willow tissues, not a food concentration study.

App: Useful context for remediation and sourcing discussions where mining-basin soils, willow phytostabilization, or genotype-specific Cd/Cr uptake are relevant.

Courses: Good teaching example for separating environmental remediation data from edible-product evidence and for preserving organ, genotype, treatment, and speciation limits during evidence routing.

Wiki pages this source may touch

• Agronomic mitigation
• Remediation evidence — drivers and interventions
• Arsenic
• Cadmium
• Chromium
• Copper
• Lead
• Nickel
• Testing

Verification notes

This page was built from the full PDF, including the abstract, Table 1 soil concentrations, Figure 1 soil summaries, Table 2 root/stem/leaf concentrations, Figure 2 organ plots, Table 3 genotype comparisons and CDA results, the discussion, materials and methods, conclusions, and data-availability statement. Products and ingredients are intentionally empty because the source does not measure edible commodities or consumer products. The source reports total elemental concentrations after digestion; arsenic and chromium species are not separated.

Audit subagent (2026-06-02) flagged frontmatter metals: [..., As] as inconsistent with CLAUDE.md Part 14, which lists tAs/iAs as non-negotiable speciation distinctions; verified against source Methods (aqua regia + HNO3/H2O2 digestion, ICP-OES, no inorganic-arsenic separation) — corrected frontmatter to tAs. Body prose retains “As” per the dominant convention in other tAs-tagged source pages.

Audit subagent (2026-06-02) flagged the Cu2(OH)3Cl fungicide pre-treatment as a methodologically important omission from the prior Methods section; verified against source page 13 (“The willow cuttings were soaked in fungicide [Cu2(OH)3Cl] before planting.“) — added a one-sentence note in Methods that this is a confounder for Cu accumulation results.

Audit subagent (2026-06-02) flagged the five matrices: strings (mining-basin-soil, salix-root, salix-stem, salix-leaf, phytoremediation-trial) as outside the standard matrices vocabulary. Per the systemic-vocab-gap precedent established by jarwar2023, houston2023, yang2023, and tang2024 retro-audits on 2026-06-02, non-standard remediation-domain matrices are documented as a systemic vocabulary gap rather than a per-page defect; matrices are retained as descriptive bare strings.

Page history

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