Sorption of 137Cs and 90Sr on Organic Sorbents

The present study examines the sorption of Cs (I) and Sr (II) on organic sorbents in the pH range from 2 to 10, as well as the mechanisms of their binding. In order to determine the influence of the physical properties and the quantity of functional groups of the organic sorbents on sorption, experiments were carried out on organic materials of varying degrees of metamorphism: high-moor peat, hard and brown coals and shungite. A detailed description of their mineral composition, cation exchange capacity, buffering capacity and elemental composition of sorbents is provided. XRD, XRF, SEM and BET adsorption methods were used for assaying. As a result of the conducted research, it can be concluded that Sr (II) showed a higher sorption per unit specific surface area than Cs (I) in the studied range of concentrations and pH values. Sr (II) sorption decreases in the following order: high-moor peat > brown coal > shungite > hard coal. The sorption of Cs (I) is highest on brown coal and lesser for high-moor peat, shungite and hard coal. It is suggested that Cs (I) and Sr (II) can be fixed on carboxyl functional groups and Cs (I), possibly, in insignificant amounts on phenolic hydroxyls of all four studied organic sorbents.

Changes in the content of heavy metals in soils due to the application of waste from the pulp and paper industry

This paper presents the results of a study of changes in the heavy metals content of soils of Karelia (podzolic loamy and peats high moor). Waste from wood processing, pulp and paper industry was added to the soils as organic additives using sodium lignosulfonate as an example. The results showed that no correlation with the additive dose was found in the series of total (Fe, Mn, Cu, Zn, Ti, Al, Ni, Co, Cr, Cd, Mo) and available forms of metals (Cu, Zn, Ti, Al, Ni, Co, Cr, Cd, Mo). Nevertheless, there is a positive correlation between the total and available forms of Pb and the available forms of Fe and Mn (r = 0.9), which can be explained by their initial content in the industrial plant material. It should be noted that the content of all forms of the studied metals did not exceed the requirements of sanitary-hygienic standards and geochemical background typical for soils in Karelia. Keywords: PODZOLIC LOAMY SOIL, PEATS HIGH MOOR SOIL, SODIUM LIGNOSULFONATE, HEAVY METALS

The Effect of Neutralising Materials on the Reaction of the Peat Substrate Medium when Growing Ball-Rooted Seedlings

The use of various types of neutralising materials in the cultivation of standard planting material of high-quality forest wood species has a significant effect on substrate acidity. Therefore, the study sets a goal to select peat substrates with different dosages of the neutralising component and determine their effect on the reaction of the peat substrate medium. The paper presents the results of the influence of neutralising materials of dolomitic meal and chalk of various doses with the use of mineral fertilisers. Dolomitic meal was used as a neutralising component, the pH of the peat substrate was 6.6 and chalk was 7.5. It was found that when neutralising a peat substrate created based on high-moor milled peat (pH 2.5) with the introduction of dolomitic meal in doses of 2-4 kg/m3 (European spruce), 3-4. 5 kg/m3 (Scots pine), optimal acidity can be achieved in a month. An increase in the concentration of lime material was recorded, which leads to an increase in the neutralisation of the substrate at a dose of 2.5 g and 3.0 g per 125 g of peat. The best indicators were demonstrated by options of doses of 1.5-2.5 g per 125 g of peat for 7-8 days of use and a dose of 3.0 g per 125 g of peat for 5-6 days compared with the control. An increase in the concentration of chalk in the neutralising material from 30% to 70% leads to a faster deoxidation of the substrate (pH 3.2), and an increase in the dosage of chalk increases substrate neutralisation. The electrical conductivity of the substrate at a dosage of 6-8 kg/m3 when applying chalk and dolomitic meal increases by 1.6-2.0 and 1.2-1.4 times, respectively. At the rate of application of 6-10 kg/m3, it has a lesser effect on the change in the electrical conductivity of the high-moor peat, and the introduction of dolomitic meal 2-4.5 kg/m3 into the milled peat during neutralisation does not lead to a change in the electrical conductivity of the peat. This data allows choosing neutralising materials of a certain concentration that will enable the cultivation of standard planting material of European quality and thereby ensure the proper quality of future stands

INFLUENCE OF PEATS HUMIC SUBSTANCES ON THE STATE OF DROPS OF CRUDE OIL AND OIL PRODUCTS IN THE PRESENCE OF OIL DEGRADING MICROORGANISMS OF THE GENUS RHODOCOCCUS

Максимальное диспергирование капель модельных нефтепродуктов в присутствии микроорганизмов Rhodococcus erythropolis X5 и гуминовых кислот сфагнового верхового торфа, а также микроорганизмов Rhodococcus erythropolis S67 и гуминовых кислот тростникового низинного торфа. Проведенный экспресс-тест доказал, что уменьшение пленки нефтепродуктов может быть использовано для проверки диспергирующей способности микроорганизмов Rhodococcus X5 или S67 и молекул гуминовых кислот. Установлено, что биокомпозиция на основе гуминовых кислот и микроорганизмов-нефтедеструкторов рода Rhodococcus способна адсорбироваться на границе раздела нефть-вода, переводя нефть в водную толщу, где она разлагается микроорганизмами-нефтедеструкторами. Maximum dispersion of droplets of model petroleum products has been observed in the presence of microorganisms Rhodococcus erythropolis X5 and humic substances of sphagnum high-moor peat, and microorganisms Rhodococcus erythropolis S67 and humic substances of reed fen peat. The express test proved that the reduction of the oil sheen can be used to the test the dispersing ability of microorganisms Rhodococcus X5 or S67 and humic substances. It has been established that a biocomposition based on humic substances and oil degrading microorganisms of the genus Rhodococcus is capable of adsorbing at the oil-water interface, transferring oil into the water column, where it is decomposed by oil degrading microorganisms.

Influence of thin-layer soil analogues on the production process of lettuce plants in intensive artificial-light culture

Relevance.The solution to the problem of providing the population of our country with high - quality plant production all year round is possible when creating high-tech automated phytotechnological complexes based on innovative, resource-saving technologies for growing plants in an artificial climate, including the development of a new generation of root inhabited thin-layer analogues of soils.Materials and methods. The research was carried out under controlled conditions of intensive artificial-light culture, when growing lettuce plants of the Typhoon variety on thin - layer analogs of soil of various composition and a low-volume soil analogue based on high-moor peat with a low degree of decomposition "Agrofit", selected as a reference for comparison, in plant growing light equipment developed at Agrophysical Institute.Results. Evaluation of the influence of thin-film analogues of the soil based on the suspensions Cambrian clay, and /or sapropel in different ratios on the production process of lettuces showed when compared with control (hydrophilic fabric): a positive tendency to increase of height, number of leaves per plant; a significant increase in wet mass by 25-35%, dry mass in 54-80%, percent dry matter in 16-36%; increase of leaf area and photosynthetic capacity at 20-36%, net productivity of photosynthesis by 16-45%; a significant or in a form of tendency to increase in the content of potassium by 14-17%, calcium by 27-35%, zinc by 29-53% and disaccharides by 28-68%. In comparison with the low-volume analogue of the soil based on high-moor peat of a low degree of decomposition "Agrophyte" (standard), it was found an increase in the form of a pronounced positive trend in growth indicators - the height and number of leaves. wet, dry mass of plants, percentage of dry matter; net productivity of photosynthesis, a reliable or in form of trend to increase in leaf area, photosynthetic potential by 20-30%; an increase in the content of mineral elements in lettuce leaves. Possible reasons for the lower productivity of lettuce plants in the control were determined, and it associated with an increase in water intake in leaf tissues against the background of the absence of additional mineral and / or organic nutrition. The content of heavy metals and nitrates did not exceed the maximum permissible concentration (MPC) in all variants. All thin-layer analogs of the soil with the application of suspensions of various compositions can be recommended for growing lettuce in any cultivation facilities in conditions of intensive artificial-light culture.

Optimization Of Plant Development In Case Of Soil Salinization

This article discusses the improvement of the development of biotests in saline soils with the addition of zeolite, phosphogypsum, organic fertilizers. The development of biotests on seawater with a concentration of 1-10 g / l improved when humates, KNO3, and water extracts from crop residues were added to the water. A decrease in the salinity of the upper soil layer is shown when an interlayer with large pores from high moor peat is created at a depth of 25 cm.

STABILIZING ABILITY OF HUMIC SUBSTANCES AND MICRO-ORGANISMS OF THE GENUS RHODOCOCCUS IN THE RELATION TO OIL PRODUCTS

Изучено влияние микроорганизмов рода Rhodococcus на стабилизирующую способность гуминовых веществ торфов по отношению к углеводородам нефти. Установлено, что наиболее стабильными являются водные эмульсии гексадекана и нефти в присутствии микроорганизмов Rhodococcus erythropolis S67 и гуминовые вещества тростникового низинного торфа, а по отношению к водной эмульсии дизельного топлива - гуминовые вещества сфагнового верхового торфа и Rhodococcus erythropolis Х5. Доказано, что полученная биокомпозиция на основе гуминовых веществ торфов и микроорганизмов рода Rhodococcus способна стабилизировать эмульсии углеводородов нефти в воде за счет связывания их гуминовыми веществами торфов в нетоксичные комплексы. The effect of microorganisms of the genus Rhodococcus on the stabilization ability of humic substances of peats in the relation to oil hydrocarbons was studied. It was found that the most stable aqueous emulsions of hexadecane and oil in the presence of microorganisms Rhodococcus erythropolis S67 and humic substances of reed fen peat and emulsion in the relation to fuel - humic substances of sphagnum high-moor peat and Rhodococcus erythropolis X5 . It is proved that the obtained biocomposition based on humic substances of peats and microorganisms of the genus Rhodococcus is able to stabilize emulsions of oil hydrocarbons in water by binding them with humic substances of peat to non-toxic complexes.

THE INFLUENCE OF HUMIC ACIDS IN THE PRESENCE OF OIL-DEGRADING MICROORGANISMS OF THE GE-NUS RHODOCOCCUS ON THE SOWING QUALITIES OF COCKWEED IN OIL POLLUTION

By the method of biotesting, it has been established that the addition of oil-degrading microorganisms of the genus Rhodococcus to the soil contaminated with hydrocarbonshas a positive effect on morphogenesis and sowing qualities of the cockweed test culture, which is associated with the microbiological oxidation of oil by bacteria of the studied strains. It was revealed that a positive effect was observed in 5 of 8 variants of the experiment on the medium with hexadecane with the joint introduction of humic acids and microorganisms. Under the conditions of oil pollution, the introduction of Rh. erythropolis X5 and Rh. erythropolis S67 microorganisms into the substrate with the addition of humic acids as a whole has a stimulating effect on the morphogenesis and sowing qualities of cockweed. It should be noted that it was in the “oil + humic acids + microorganism” variant that the indicators were obtained that maximally exceeded the values of the contaminated control. Reducing the toxicity of oil and hexadecane, and in some cases, the complete removal of the negative effects of toxicants in the relation to the test culture are apparently connected with the intensification of the process of oil biodegradation due to the stimulating effect of humic acids on the microorganisms. It is proved that the introduced humic acids act as adaptogens in the relation to the microorganisms Rh. erythropolis X5 and Rh. erythropolis S67, increasing their resistance to stress loads under conditions of oil stress. Thus, the results show that the introduction of humic acids can contribute to more effective biodegradation of oil pollution of soils. At the same time, in order to increase the efficiency of humic acids, the use of humic acids of sphagnum transitional peat + Rh.erythropolis X5, humic acids of sphagnum high-moor peat + Rh. erythropolis X5, humic acids of reed fen peat + Rh. erythropolis S67 in the conditions of oil pollution seems more promising. On a substrate with hexadecane, it is advisable to consider the use of humic acids of sphagnum high-moor peat, because in this variant, the parameters that maximally exceed the contaminated control were noted.