Evaluation of the Phytoremediation Potential of the Sinapis alba Plant Using Extractable Metal Concentrations

Testing the feasibility of soil phytoremediation requires the development of models applicable
on a large scale. Phytoremediation mechanisms include advanced rhizosphere biodegradation,
phytoaccumulation, phytodegradation, and phytostabilization. The aim of this study was to evaluate
the phytoremediation potential of the Sinapis alba. Identification of the factors influencing the extraction
process of metals from contaminated soils in a laboratory system suitable for evaluating the
phytoavailability of these metals in three solutions (M1-CaCl2, M2-DTPA, and M3-EDTA) included
the following: distribution of metals in solution (Kd), soil properties and mobile fractions (SOC, CEC,
pH), response surface methodology (RSM), and principal component analysis (PCA). The evaluation
of the phytoremediation potential of the Sinapis alba plant was assessed using bioaccumulation
coefficients (BACs). The accumulation of heavy metals in plants corresponds to the concentrations
and soluble fractions of metals in the soil. Understanding the extractable metal fractions and the
availability of metals in the soil is important for soil management. Extractable soluble fractions may
be more advantageous in total metal content as a predictor of bioconcentrations of metals in plants.
In this study, the amount of metal available in the most suitable extractors was used to predict the
absorption of metals in the Sinapis alba plant. Multiple regression prediction models have been
developed for estimating the amounts of As and Cd in plant organs. The performance of the predictive
models generated based on the experimental data was evaluated by the adjusted coefficient of
determination (aR2), model efficiency (RMSE), Durbin–Watson (DW) test, and Shapiro–Wilk (SW) test.
The accumulation of the analyzed metals followed the pattern Root > Pods > Leaves > Seeds, stems >
Flowers for As and Leaves > Root > Stem > Pods > Seeds > Flowers for Cd in soil contaminated with
different metal concentrations. The obtained results showed a phytoremediation potential of the
Sinapis alba plant.