Phytoremediation of soils amended with landfill leachate sludge using Nicotiana alata L. under different heavy metal loads

ABRILE, M. G.; ORECCHIA, D. S.; OSORIO, J.; CLEMENTI, L.; FIASCONARO, M. L.; LOVATO, M. E.

INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY

CTR ENVIRONMENT & ENERGY RESEARCH & STUDIES

Año: 2024

1735-1472

The application of sludge to infertile and organically defcient soils, combined with phytoremediation techniques to support soil restoration, shows promise for rehabilitating extensively disturbed sites, such as landflls. This study aimed to evaluate the efects of biosolid-amended soils with varying levels of heavy metal contamination on the phytoextraction efciency, growth, and development of Nicotiana alata L. The sludge-amended soil was artifcially contaminated with varying con￾centrations of Pb, Cr, and Ni. A Box-Behnken experimental design was employed with three factors, each representing a specifc metal added at three levels: 0, 150 and 300 mg kg−1 of dry mass. At harvest time, phenological and physiological parameters were measured in plant tissues. Heavy metal content, along with bioconcentration and translocation factors were determined to assess phytoextraction efcacy. The highest concentrations of Pb, Cr, and Ni observed in the roots were 269 mg kg⁻1, 273 mg kg⁻1, and 273 mg kg⁻1, respectively. However, in aerial tissues, the maximum values found were 38, 8, and 81 mg kg⁻1 for Pb, Cr, and Ni, respectively. Overall, N. alata exhibited a greater afnity for extracting and translocating Ni in its tissues, followed by Pb and, lastly, Cr. These diferences may be associated with specifc biological roles of Ni and variations in metal mobility in soils. Metal extraction variables were statistically linked to metal concentrations in the soil. Interaction efects among contaminants were observed, highlighting the importance of their joint assessment rather than one-dimensional analyses.