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One of the heavy metals immobilizing methods, apart from the conventional methods such as liming and organic fertilization, is the usage of unconventional binding agents. Modified alluminiumsilicates, such as Al-montmorillonite and Polynuclear aluminium form (Al₁₃⁷⁺) offer some promising results. The main goal of this work was to evaluate the influence of the used mineral sorbents: sodium silicate and modified aluminium silicates compounds on single fractions of cadmium and zinc content changes in the soil under heavy wheat. The experiment’s scheme included 18 scenarios (A) and two plant development stages (B) within two repetitions. Scenarios (A) of the experiment were created by the insertion of soluble zinc and cadmium salts, as well as the immobilising agents into the chosen pots. The Al₁₃ addition at the level I proved to be most effective in decreasing the contents of mobile cadmium forms in the soil environment. Whereas, the addition of Al₁₃ at the level II and Al-montmorillonite, instead of the expected cadmium immobilization, boosted the mobility of this element’s ions in the soil.
Zakwaszenie gleb prowadzi do występowania niedoborów selenu w środowisku przyrodniczym. O mobilności selenu w glebie w znacznym stopniu decyduje, oprócz pH, działalność bakterii. Rośliny są ważnym ogniwem decydującym o niedoborze lub nadmiarze omawianego pierwiastka śladowego w paszy zwierząt i w diecie ludzi. Zarówno nadmiar, jak i niedobór selenu w środowisku ma niekorzystny wpływ na zdrowie i życie zwierząt i ludzi.
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Aluminium solubility in the presence of citric acid

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The present study points to an important role of citric acid in limiting toxicity of aluminium ions for pea plants which was confirmed by the plants’ growth, development and yield. Excess of aluminium influenced plant nutrition with Ca, P, Mg, and K as this toxic element did not only gather in the roots of the studied plants but also in their above-ground parts. Limitation of aluminium toxicity by its complexing with citric acid clearly influenced a increase in the Fe uptake by plants and an decrease in the Mn uptake which was statistically proved.
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A significant increase of pHKCl values was noted by the transfer from objects A (the plants fell completely out) to objects C (the plants grew normally). In the places where the arable layer of soil contained over 70 mg A1 kg⁻¹ the grains showed distinct symptoms of physiological illness, and at the content over 90 mg A1 kg⁻¹ the plants fell out completely. In spite of distinct differences in the growth and development of plants between several objects (A, B, C), the content of basic macroelements and aluminium in the above-ground parts and roots of plants proved stable. The increase of physiological illness symptoms in the particular grain plants was mostly connected with the occurrence of mobile aluminium. The increaes in Al³⁺ concentration in soil limited the growth and development of plants and, in extreme cases, drying and falling out proceded.
The aim presentated investigcations was the determination of the effect of high concentrations of aluminium in the soil on the content of available magnesium in the soil and in cereals plants and formation of K: (Ca + Mg) ratio in four basic growth stages of plants. The apperance of mobile aluminium in the soil in amount more than 40 mg Al kg-1 effected increasing of ralue of K: (Ca + Mg) ratio in barley, wheat and rye.
In order to immobilize heavy metals, sorbents that meet the following three criteria can be used: 1) they are non-toxic 2) they cannot make the physicochemical properties of soil worse, and even improve them 3) they have an immobilizing and specific impact on heavy metals. This study compares the influence of mineral and organic sorbents, as well as the presence of selenates (VI), on limiting lead toxicity in a soil. The investigations have also focused on evaluating the effects of these sorbents on select physicochemical and chemical properties of studied soil material collected during the two- year strict pot experiment. Achieved results indicate greater affinity of lead to mineral rather than organic sorbents, although it has depended on zealot and humic acid rates, as well as on physicochemical properties such as soil acidity or soil sorption capacity. Sodium selenate (VI) affected the mobilization of Pb' ions in the pot experiment and the effect was probably associated with subsoil pH changes and excessive doses of the sorbent used in the experiments. The study also has aimed at evaluating soil conditions, under which cadmium toxicity appears, as well as at presenting the possibilities of reducing their activities through the use of unconventional immobilizing agents such as zeolites, humic acids, and selenates (VI). The immobilization of Cd2 ions has been affected both by zeolites and humic acids, but only when applied at lower rates. The influences of cadmium mobilization and immobilization on changes in Cd:Zn and Fe:Mn ratios in soil also have been indicated. Clinoptilolit has appeared to be a promising binding agent for immobilizing the cadmium ions. Applying the selenium compounds has given hope as well, because the element is more often considered as required for living. However, the selenium action mechanism is complicated and not uniform, which needs to be further examined.
The application of some of the agents such as the organic substance or silicon compounds may, under certain conditions, control the level of ions of toxic matter in the soil solution. The aim of this work was to explore the influence of the artificial humic acids and sodium silicate present in the soil on the modification of the content of various fractions of aluminium and manganese in the soil samples collected after harvesting two varieties of wheat (HeliaandIsmena) within two phases: earing and full maturity. The scheme of the experiment research included 11 scenarios (A), two varieties of spring wheat (B), as well as two of the plants development stages (C) within two repetitions. Scenarios (A) of the experiment were designed through the insertion into the selected pots of the soluble aluminium and manganese salts, as well as the immobilising agents. The concurrent addition of the organic substance (humic acid sodium salt) and the mineral substance (sodium metasilicate) reduced to the highest degree the level of the mobile forms of aluminium and manganese in the soil environment. Moreover, it influenced the creation of the largest number of ‘weak’ and ‘strong’ bondings between Al and the organic substance, as well as ‘weak’ bondings between Mn and the organic substance.
The aim of the present study was to determine the influence of the reaction and organic substance on the effectiveness of zinc and cadmium binding by Al₁₃ The presence of organic substance in the combinations with Al₁₃ and toxic elements did not block the binding Al₁₃ activity. However, its type and amount influenced the effects of cadmium and zinc immobilisation and mobilisation. Cadmium in the solution was antagonistically related to zinc and other microelements in the plant which was confirmed in the mineral composition and presentation of the studied plants.
The aim of this research was to show, that sorption and desorption processes of organic hydrophobic compounds on humic acid fraction can influence the microbial degradation rates of contaminants. This study was carried out in the Netherlands in 1996. Chlorinated benzene (pentachlorobenzene QCB) and a polychlorinated biphenyl (2.5-dichlorobiphenyl) were used as a model compounds.
This article studies the effect of Aln, sodium humate, and sodium silicate on metal solubility and their bioaccumulation in pea plants. Research was carried out in 1997 using water cultures. There were three series of quick 2-week tests of plant reactions towards Zn2+, Cd2+ (series I), Al3+ (series II) and Mn2+ (series III) added in the form of soluble salts into modified Knopp's substrate. The toxic amounts of Zn and Cd were added into the basic substrate in a form of soluble nitrate. Toxic quantities of Al and Mn were added into the substrate in a form of soluble salts: A1C13 • 6H2O and MnSO4 • H2O, respectively. Sodium humate, AI13 or both preparates were added into some objects to study zinc and cadmium immobilization (series I). Sodium silicate (IV), humic acid (Aldrich) or both were added into some objects in order to differentiate aluminum and manganese contents in the environment (series II and III). Accumulation coefficients calculated for Zn and Cd showed that zinc presence in the substrate inhibited cadmium accumulation in the plant. Cadmium was easily accumulated in over-ground parts. Zinc was released due to Ali3 with humic acid presence and then it accumulated in roots. Silicon compound, especially along with humic acid presence, was the factor determining the mobilization or immobilization of Al and Mn in the environment and thus it affected the yields of plants under study.
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