Articles

Heavy metal toxicity in plants is well known due to their severe phytotoxic effects and also because of their capability to accumulate in vegetables. The use of aromatic plants in remediation techniques has increased in the context of environmental pollution issues, including metal soil contamination. Cadmium is known as a toxic and bio accumulative element provided by natural or anthropic sources. In this context, the paper presents a laboratory experimental study aiming to evaluate the accumulating and transfer behavior of Cd in the plant organs of Sinapis alba L. (white mustard) and in the presence of essential elements (Ca, Mg, Fe, Zn, Mn, Cu, Ni). The study involves a comparison between white mustard cultivated in unpolluted soil and in two Cd polluted soils at values above the alert (2.8 mg/Kg), respectively intervention threshold for soils with sensitive use (5.6 mg/kg) according to the legislation in force in Romania. While Cd accumulated predominantly in roots (TC values 1.46 and 2.22), its transfer to the stem and leaves was observed too, the TF values for the aerial part of the plant being greater than 1. Moreover, the study showed that certain elements (Zn, Ca, Mg, Mn) were found in higher concentrations in plants subjected to Cd pollution than in the control sample indicating antagonistic effects and Cd toxicity limiting. Other essential metals, such as Cu, Fe and Ni were found in lower concentrations in intoxicated plants compared to control plants. Their translocation from soil in plant organs could be reduced by the Cd toxicity. Contrariwise, the mobility of these elements from roots to leaves could support the tolerance effect of plants to Cd stress. The study allows us to consider that Sinapis alba L. aromatic plants are suitable for soil phytoremediation technologies used in Cd decontamination.

The present study investigates the distribution of some toxic metals such as As, Cd, Cu, Cr, Co, Hg, Ni, Pb, Ti within sediments and surface water from Baiaga stream, situated near an abandoned mining site from Certeju de Jos, Hunedoara County, in the vicinity of two mining sterile dumps and Coranda Pit. The entire studied area indicates an acid pH, both in surface water and sediments. Mobile metallic concentrations were evaluated using first step of BCR 701 sequential extraction modified scheme. The total and mobile content of metals from sediments were determinate using inductively coupled plasma optical emission spectrometry. Calculated bioavailability index (Ibio) was used in order to correlate the presence of toxic metal in surface water. The experimental data shows important concentrations of metals (Cd, Co, Cu, Ni, Pb) in surface water correlated with relatively high bioavailability index, that include the surface water in fifth quality class (the worst) according to Romanian Order 161/2006. Low content of metals (As, Hg, Ti) in surface water despite the high concentrations presented in sediments represents the effect of lack of mobility (Ibio less than 0.1%). The bioavailability index represents a useful tool for sediment control in acidic mining sites.

The paper presents a comparative bioaccumulation study between the growth of chamomile (Matricaria Chamomilla L.) exposed to toxic metals (Cd, Ni and Pb) and the growth of same plant species unexposed to metals. The soil was contaminated within three independent experiments with Cd, Ni and Pb at the intervention threshold value for sensitive use. Each of the toxic metal was added by watering the seeds, and subsequently the germinated plants. The experiments targeted the effects of soil pollution on the growth of chamomile during three months period. The results showed that in the first month of the study, all three metals accumulated in plants. After the seeds germination and plant growth, high Cd concentration in chamomile plants was detected. Moreover, Ni and Pb were detected in soil in the percentage of 96%. Overall, it was observed that chamomile plants were Cd accumulators at the tested concentrations of 6 mg/kg with no phytotoxic effects. Matricaria Chamomilla L. could be used in phytoremediation of polluted soils, with limitations of use for human consumption, except for the extracts.

Mining activities are recognized as generating adverse effects on the environmental quality. The waste resulted from ore processing activities settled on the ponds was established as a significant pollution source of the soil and groundwater in the site areas. The paper presents the spatio-temporal variation of the characteristics of groundwater in the area of a waterproofed pond, located near two other tailings ponds, unenriched, of an age of over 30 years. Groundwater quality is highlighted in an area situated in the north of the country in terms of metals content determined in several seasonal campaigns.

The paper presents a monitoring study of the platinum group metals concentrations in 17 samples of road dust and vegetation from areas with heavy car traffic on several European and national roads in eastern Romania. The Ir, Pd, Pt, Rh, Ru concentrations were determined by the ICP-MS technique, the reported values being below the method’s limit of determination for Ir, Pt and Ru both in soil and vegetation. As regards the Pd content, it showed a maximum of 794µg / kg dry matter in Focsani area (DN2), an area where, according to national data published by National Road Infrastructure Management Company, the traffic average is 16,000 vehicles / 24 h. Approximately 50% of the collected vegetation samples showed a Pd transfer factor from the solid part to the vegetation higher than 0.5, thus indicating the existence of Pd toxic compounds bioavailable for vegetation. The highest concentrations of Rh in soil were recorded on a high traffic section on the E85, in Ramnicu Sarat area, where the traffic interval ranges from 8,001 to 16,000 vehicles / 24 h

The soils situated near the abandoned mines are highly polluted with metals due to the discharge and dispersion of mine waste into nearby air, water (surface and groundwater) and soil. Heavy metals may be transferred to humans through ingestion, inhalation or dermal absorption and can produce serious health problems affect the nervous, endocrine and immune systems, hematopoietic function and cellular metabolism. This paper investigates the presence of metallic elements from fourteen soil samples (seven sampling points) and thirty-six vegetation samples (different types of leaves, plants, roots and tree barks). The samples were collected from six different sites located in an abandoned mining area and from a point (blank sample) located 5 km in the SV direction of the quarry. The results obtained for soil samples show an overrun of the alert and / or intervention threshold for the following metals: arsenic, cadmium, cobalt, copper, manganese, nickel, lead and zinc. The analytical investigation for vegetation samples indicated that concentration for calcium, magnesium, cadmium, chromium, manganese, nickel, lead, zinc were situated over the normal range in some samples. The analytical investigations were performed by optical emission spectrometry (ICP-OES). The study’s conclusion indicates that, as result of soil acidic pH and high mobility of some metals, metallic elements migrate from soil to vegetation.

The Danube River is the major source of drinking water supply for the cities in the southern part of Romania. The study was a descriptive-analytical one and lasted for 9 month. Samples were taken monthly between March 2016 and November 2016. Six sampling sites were selected to evaluate the spatial and temporal changes of water quality along the river. The samples were analyzed based on the standard methods for the following parameters: pH, conductivity (EC), NH4+, NO3-, Cl-, suspended solids, PO43-, SO42-, metals (Fe, Cd, Cr, Pb, Ni, Hg, As, Zn, Cu, Mn). The obtained values were compared with those imposed by the Romanian environmental legislation. An efficient and simplified method to express the quality of water used for consumption is provided by the Water Quality Index (WQI). WQI reflects the quality of water in a single value by comparing data obtained from the investigation of a number of physico-chemical parameters to the existing limits. The evaluation of water quality was performed using the Water Quality Index of the Canadian Council of Ministries of the Environment (CCME WQI). Water quality indices were classified as: excellent, good, medium, bad and very bad. The results indicated the water quality classification as “good” in all six sampling selected sites.