TEUTA BUSHI1*, AIDA BANI2, FRANZ OTTNER3
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1Department of Physics, Agricultural University of Tirana, Albania 2Department of Environment and Natural Resources. Agricultural University of Tirana, Tirana, Albania 3Institute of Applied Geology, Department of Civil Engineering and Natural Hazards, Austria Abstract Serpentine soils in Albania are naturally enriched in nickel (Ni), which limits agricultural productivity due to Ni toxicity. This study aimed to evaluate the effectiveness of nano-montmorillonite clay in remediating Ni-rich soils using the nickel hyperaccumulator Odontarrhena Chalcidica as a test plant. The experiment was conducted in a greenhouse under a completely randomized design with three replications. Each experimental unit consisted of a 2 kg plastic pot. Four doses of nano-montmorillonite were tested: 0.0, 21.4, 43.4, and 64.0 g kg⁻¹ (0%, 1.07%, 2.17%, and 3.2%), corresponding to field application rates of 0, 30, 60, and 90 t ha⁻¹, respectively. The effects of the treatments were evaluated at two time intervals: 60 days and 6 months. The main innovation of this study lies in the application of nano-clay technology for Ni immobilization and the assessment of its long-term efficiency. Results demonstrated a strong remediation effect of nano-montmorillonite. After 6 months, the application of 43.4 g kg⁻¹ clay reduced water-extractable Ni by 77.6% compared to the control (from 8.50 mg kg⁻¹ to 1.89 mg kg⁻¹). The highest dose (64.0 g kg⁻¹) further decreased the concentration to 1.64 mg kg⁻¹. In addition, the amendment significantly lowered Ni accumulation in plants and increased biomass production, confirming a substantial reduction in phytotoxicity. Overall, nano-montmorillonite proved to be an effective and sustainable strategy for improving soil safety and agricultural productivity in Ni-contaminated serpentine soils, aligning with EU environmental standards Keywords: clay, nano-montmorillonite, hyperaccumulator, Odontarrhena chalcidica, serpentine soil |
