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.

Ni(II)-Salophen-Comprehensive Analysis on Electrochemical and Spectral Characterization and Biological Studies.

New aspects of the Ni(II)-salophen complex and salophen ligand precursor were found during deep electrochemical and optical characterization, as well as biological studies for new pharmacological applications. Physicochemical and spectroscopic methods (1H- and 13C-NMR, FT-IR and UV-Vis, electrospray ionization mass spectroscopy, thermogravimetric analysis, and molar conductance measurements) were also used to prove that the salophen ligand acts as a tetradentate and coordinates to the central metal through nitrogen and oxygen atoms. The electrochemical behavior of the free Schiff salophen ligand (H2L) and its Ni(II) complex (Ni(II)L) was deeply studied in tetrabutylammonium perchlorate solutions in acetonitrile via CV, DPV, and RDE. Blue films on the surfaces of the electrodes as a result of the electropolymerization processes were put in evidence and characterized via CV and DPV. (H2L) and Ni(II)L complexes were tested for their antimicrobial, antifungal, and antioxidant activity, showing good antimicrobial and antifungal activity against several bacteria and fungi.

Overall assessment of surface water quality in the Lower Danube River.

Water is an important receptor of environmental problems generated by anthropogenic activities, the water quality being affected by their magnitude and impact as well as by climate change. Given the international and cross-border nature of the Danube River and being aware that the pollution risk assessment is one of the key elements of the ecology and health of the people in its region, this paper assessed the state of water quality in the Lower Danube River in accordance with Water Framework Directive (Directive 2000/60/EC). The intensive monitoring program applied by the National Institute for Research and Development in Environmental Protection (INCDPM) took place during the period 2011-2017, in which approximately 1500 samples were taken and processed from 10 monitoring sites and the quality indicators stipulated in M.O. 161/2006 were analysed according to the standards in force. In this monitoring area (km 375-km 175), hydrotechnical works have been done in order to improve navigation conditions. Therefore, on the basis of the data obtained from the monitoring campaigns, multivariate statistical methods of water quality assessment were applied on the complex set of data, and at the same time, the multiparametric quality index (ICPM) was applied, an index of global comparative assessment of water quality over historical trends, developed by INCDPM. Following the evaluation of the results, the water quality in the Lower Danube River was characterized as moderately polluted and corresponds to Class III of surface water quality. The ecosystem approach indicates that the values of the monitored indicators did not correspond to the target values according to the Water Framework Directive.

Aided phytostabilization using Miscanthus sinensis × giganteus on heavy metal-contaminated soils.

A field experiment was carried out to evaluate the use of red mud, a by-product of the alumina industry, as a soil amendment on highly contaminated soils in the vicinity of a former Pb-Zn smelter in Copșa Mica (Romania). Changes in the distribution of Zn, Cd and Pb in various soil fractions, mobility of heavy metals in the soil, and their uptake and effects on growth and productivity of Miscanthus sinensis × giganteus were evaluated. Uptake of Zn, Cd and Pb was determined in different tissues of M. sinensis × giganteus cultivated in field plots situated at increasing distance from the pollution source and with different levels of contamination and metal availabilities. Soluble metal concentrations were determined in centrifugates, whereas potentially soluble fractions were analyzed by diffusive gradients in thin films. In terms of the biomass productivity there were significant differences among the plants obtained in plots with different characteristics and pollution levels. Bioconcentration factors were much lower than 1, indicating that M. sinensis × giganteus is an excluder of heavy metals, especially Pb. Amending soils with red mud reduced the exchangeable or phytoavailable fractions of Zn, Cd and Pb. Overall the results suggest that M. sinensis × giganteus is a valuable energy plant and can be successfully grown on heavily contaminated soils with Zn, Cd and Pb. Moreover, the addition of red mud to these soils can lead to a significant decrease in the concentration of heavy metals in the soil and in metal uptake by plant tissues.