The modeling of phytoremediation process for soils polluted with heavy metals

The state of bioavailability of heavy metals in soil is influenced by their concentration in soil solution. Some trace elements are involved in key metabolic activities such as respiration, photosynthesis and nutrient uptake and fixation. Transition metal group elements are known as enzyme activators or are incorporated in metallo-enzymes as electronic transfer systems. These metals can also serve as catalysts to change valence in the substrate. A basic requirement for optimal growth and development of plant is the chemical equilibrium, based on the interaction of elements found in the body. Each metallic element is accumulated differently by plants; the factors influencing their absorption are the species and metal content of soil. The absorption of Cu is strongly influenced by metal concentration in substrate and less by the species. Among other heavy metals, Ni and Cr in soil strongly influence the absorption of copper, and among the macronutrients, P has a synergistic effect. Zinc absorption is also dependent on the species and the metal concentration in soil. Among heavy metals, the Pb content in soil has the greatest synergistic effect on the absorption of Zn, as Mn and Cr in soil. The Sn absorption in plants is influenced most strongly by species than the presence of Sn in soil. Among the macronutrients, Ca and P have the greatest influence on the absorption of Sn in plants. Absorption of lead in plants is dependent on metal concentration in soil and is very strongly influenced by the content of Zn, Cr and Mn in the soil

The effect of metallic content of soil on the absorption and accumulation for some species of fungi used in soil’s bioremediation

The remediation of heavy metals polluted soil using biosystems involves the use of plants and fungi species for the extraction of metals from soil. To streamline the process of bioremediation of soil polluted with heavy metals using higher fungi, those species should be chosen with a high capacity to absorb metals and environmental factors can be controlled so that the accumulation of these elements to be favored. Heavy metal absorption by higher fungi is influenced primarily by the species, but also by soil pH and concentration of other metals in the soil. The interaction of chemical elements can be synergistic and / or antagonistic, and the reactions that lead to the creation of a chemical imbalance are a chemical stress for the fungi. The main correlations were observed between the Cu content in soil and concentration of Cu and Zn in fungi, elements which have a moderate positive correlation, but also between Sn content in the soil and the content of Co and Ni in the fungus. Moderate synergistic effects were observed between Co and Cr content in the soil on the absorption of Mn in higher fungi. Iron content in the soil has a synergistic effect on the absorption of Cr, Mn, Sn and antagonistic effect on the absorption of Cu, Co, Ni and Zn. Macronutrients affect the bioavailability of heavy metals in soil by changing the soil reaction. Fe and Mg have a synergistic effect on the absorption of most metals, while P, K and Ca have an antagonistic effect. Based on the synergistic and antagonistic effects between the soil components on metal bioavailability to higher fungi may be a modeling process of absorption and accumulation of heavy metals in tissues of biosystems

Heavy metals bioaccumulation in species of wild growing mushrooms

The study of some wild growing species of mushrooms from the Bucegi Mountain show important concentrations of heavy metals in the fruiting bodies. The zinc concentration range between 6.92 and 74.25 mg/kg (the highest concentration was for Calvatia excipuliformis); copper has concentration between 16.24 - 226.30 mg/kg (the highest values was also for species Calvatia excipuliformis); and tin concentration range between 16.23 - 14048.1 mg/kg (the highest values was for Hygrophorus virgineus species). The bioaccumulation factor of these metals in the fruiting body of analyzed species of mushrooms range according the metal concentrations in macrofungus and the metal content in soil. For the analyzed mushrooms, the bioaccumulation factor of zinc has values between 0.04 and 0.46, no results are important for bioremediation. The highest value was for Calvatia excipuliformis species. The copper bioaccumulation factor range between 0.83 and 3.19, the majority of analyzed species shows values of this factor higher than 1, and the most important results was for species Collybia butyracea. The bioaccumulation factor of tin has values between 0.06 and 49.61, only few species have this factor higher than 1. Hygrophorus virgineus species shows a very important value of tin bioaccumulation factor, up to 50, which make this species very efficient in bioremediation technologies

Research on soil pollution with heavy metals from main sources of pollution county Damboviţa

Metal transfer in the atmosphere, soil, vegetation, water and sediment from different sources, such as metallurgy, mining, quarrying and processing waste deposits and tailings dams, but also combustion of liquid, and solid waste. A part of total metals in the environment there as part of the natural background. Potentially toxic metals resulting from anthropogenic activities cause severe disturbance of ecosystems and therefore pollution sources must be identified, long-term pollution potential should be expected to be taken to reduce or stop pollution. Soil contamination with metals from various industrial activities is currently a major problem. Due to interactions between different environmental compartments, soil pollutants in all compartments redistribute implications on the functioning of natural biotic systems and human health. How metals are distributed and sustained change depending on physical-chemical properties of metals and environmental parameters. Today it is accepted that a number of features are its unique metals (some metals have remanence, toxicity) and that these unique properties, considered as principles to be considered in risk assessment work

Evaluation of bioaccumulation factor for some heavy metals at Lactarius piperatus species in the view of utilize it in environmental biotechnologies

The aim of this work is the evaluation of bioaccumulation factor for some heavy metals at Lactarius piperatus species. Biological samples consisted in Lactarius piperatus harvested from forestry ecosystems of Dambovita county. Were determinate the iron, manganese and nickel content of biological samples and of soil under them. Also were determinate the pH of soil samples. The chemical content was analyzed by EDXRF method with fluorescence spectrometer ELVAX. For the validation of results obtained by EDXRF were used the NIST SRM 1571-Orchard leaves standards of references. Was calculated the value of bioaccumulation factor for each metal species and for cap and stipe separated. The value of bioaccumulation factor for iron in case of Lactarius piperatus samples harvested from Bolboca forest was approximately 3510% in cap and 1532% in stipe of mushroom. At the samples prelevated from Mogoi forest, the value of bioaccumulation factor for iron was 686% in cap and 555% in stipe. It must be mention that the pH of soil samples was in all cases 6,7. In case of Lactarius piperatus samples harvested from Bolboca, the value of bioaccumulation factor for manganese was 130500% in cap. A part of samples prelevated from Mogoi had a value of bioaccumulation factor for manganese 36183% in cap. The results obtained for bioaccumulation factor of nickel indicated values between 0,5 şi 0,7% as well in stipe as in cap at all samples, no matter the sit of prelevation