Miscanthus x giganteus phytoremediation of soil contaminated with petroleum was assessed in this study. A method of soil sample preparation for determining the total content of petroleum products by infrared spectrophotometry has been developed. It is a one-stage extraction method with minimal use of carbon tetrachloride as an extractant. This soil sample preparation method was environmentally friendly and cost-effective, as it required a significantly lower amount of extractant (15-30 ml of tetrachloromethane) compared to the commonly used threefold extraction method, which uses up to 150 ml of extractant. The extraction degree of petroleum products (PP) was determined to be from 81.78 % to 94.22 % after two days of extraction using the additive method of determining PP. It was observed that the presence of different fertilizer additives in the soil samples led to a reduction in the determined PP content in the following series: "without fertilizer" - "Biochar" additive - "Biohumus" additive. These results were compared with reference samples that did not involve the use of Miscanthus x giganteus. Furthermore, the main thermolysis stages of petroleum products sorbed by the soil matrix and the thermal behavior of an artificial soil sample spiked with PP were examined. Detailed interpretation of thermograms of laboratory soil samples was conducted at various phytoremediation stages.

• Keywords
• Extraction, Infrared spectrophotometry, Miscanthus x giganteus, Petroleum products, Phytoremediation, Thermal analysis,
• Publication type
• Journal Article MeSH

Miscanthus × giganteus demonstrated good phytostabilization potentials by decreasing the trace elements (T.E.s) mobility and enhancing the degraded soil quality. Nevertheless, most of the published work was performed under controlled conditions in ex situ pot experiments and/or with soils being spiked. Hence, data about the plant's tolerance to increased T.E. concentrations in real conditions is still scarce and requires further investigation. For this sake, a field experiment was established by cultivating miscanthus plants in three different agricultural plots representing gradient trace element (Cd, Pb and Zn) concentrations. Another uncontaminated plot was also introduced. Results showed that T.E. concentrations in the leaves were tolerable to the plant. In addition, no variations were detected between the miscanthus cultivated in the contaminated and uncontaminated soils at the level of antioxidant enzymatic activities (ascorbate peroxidase and superoxide dismutase), photosynthetic pigments (chlorophyll a and b and carotenoids), and secondary metabolites (phenolic compounds, flavonoids, anthocyanins, and tannins). These outcomes validate the high capacity of miscanthus to resist and tolerate contaminated conditions. Such results may contribute to further understanding of the miscanthus tolerance mechanisms.

• Keywords
• Miscanthus × giganteus, phytoremediation, stress tolerance, trace element contamination,
• Publication type
• Journal Article MeSH

The positive impact on restoring soil functionality, decreasing toxic elements (TE) bioaccessibility, and enhancing soil physicochemical and biological parameters established a consensus on considering a Miscanthus × giganteus convenient species for phytomanaging wide TE contaminated areas. Nevertheless, information about the plant's mode of reaction to elevated soil multi-TE concentrations is still scarce. For the sake of investigating the miscanthus response to stressful TE concentrations, an ex-situ pot experiment was initiated for 18 months, with three miscanthus cultivars referred to as B, U, and A planted in soils with gradient Cd, Pb, and Zn concentrations. A non-contaminated control soil was introduced as well, and plants were cultivated within. Results revealed that the long exposure to increasing soil TE concentrations caused the number of tillers per plant to decline and the TE concentrations in the leaves to boost progressively with the soil contamination. The photosynthetic pigments (chlorophyll a, b, and carotenoids) were negatively affected as well. However, the phenolic compounds, flavonoids, tannins, and anthocyanins, along with the antioxidant enzymatic activities of superoxide dismutase, ascorbate peroxidase, and glutathione reductase elevated progressively with the TE concentration and exposure duration. Conclusively, miscanthus plants demonstrated an intensified and synchronized antioxidative activity against the TE concentration.

• Keywords
• Miscanthus × giganteus, TE contamination, antioxidative response, pot experiment,
• Publication type
• Journal Article MeSH

Miscanthus × giganteus demonstrated good phytostabilization potentials in toxic element (TE) contaminated soils. However, information about its tolerance to elevated concentrations is still scarce. Therefore, an ex-situ pot experiment was launched using three cultivars (termed B, U, and A) grown in soils with a gradient Cd, Pb and Zn concentrations. Control plants were also cultivated in non-contaminated soil. Results show that the number of tillers per plant, stem diameter as well as leaf photosynthetic pigments (chlorophyll a, b and carotenoids) were negatively impacted by soil contamination. On the other hand, phenolic compounds, flavonoids, tannins, and anthocyanins levels along with the antioxidant enzymatic activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase increased in the plants grown on contaminated soils. Altogether, these data demonstrate that miscanthus is impacted by concentrations of toxic elements yet is able to tolerate high levels of soil contamination. These results may contribute to clarifying the miscanthus tolerance strategy against high contamination levels and its efficiency in phytoremediation.

• Keywords
• Miscanthus × giganteus, antioxidant enzymes, photosynthetic pigments, secondary metabolites, toxic elements (TE),
• Publication type
• Journal Article MeSH