APPLICATION OF METHODS BASED ON SYNCHROTRON RADIATION FOR SPECIATION OF HEAVY METAL IN SOIL

The study is aimed at analyze atomic and electronic structure of Cu (II) and Pb (II) ions in the artificially contaminated soil and its mineral components using X-ray absorption spectroscopy methods based on synchrotron radiation. Soil sampling was taken in the 0-20 cm topsoil of the Haplic Chernozem of the South Russia. In a model experiment the samples taken were artificially contaminated with higher portions (2000 and 10000 mg/kg) of nitrates and oxides of Cu and Pb. The experimental X-ray absorption (XANES and EXAFS) spectra at the K-edge of Cu and LIII-edge of Pb were performed at the Structural Materials Science beamline of the Kurchatov Center for Synchrotron Radiation (Moscow) in the fluorescence regime. The features of XANES spectra indicate different orbital transitions in the electron shells of Pb (II) and Cu (II) ions for monoxide and soluble salt, which affect the ion properties and determine the individual structure of the coordination sphere. Analysis of the EXAFS revealed that Cu (II) ions are incorporated in the octahedral and tetrahedral sites of minerals and bonded with humic materials at the expense of covalent bond and the formation of coordination humate copper complexes. Lead ions in soil are incorporated in the positions of the inner-sphere complex replacing some aluminum ions in the octahedral sites. This results in changes the Pb–O distances in Pb-bearing octahedrons. We may suggest that Pb (II) is also sorbed by dimer (Pb–Pb) silicate and/or aluminum groups

Water Quality in Hydroameliorated Agricultural Areas

Three-year investigations (2007-2009) of water quality in hydroameliorated agricultural areas were carried out at the experimental amelioration field “Jelenščak” Kutina, on hydroameliorated Gleyic Podzoluvisol. Soil was drained in four different drainpipe spacing variants (15 m, 20 m, 25 m and 30 m), set up in four replications. The areas of spacing variants were: 1425 m2, 1900 m2, 2375 m2 and 2850 m2. The same crop was grown in each research year in all variants and the same agricultural management practices were applied. Winter wheat was grown in 2007 and in 2009 and soybean in 2008. Samples of drainage water were taken at drainpipe outlets into the canal. The following parameters were determined in the samples: nitrate concentration and concentration of chlortoluron. Based on the drainage water analysis, it was established that nitrate concentration as well as chlortoluron concentration exceeded the prescribed MAC values (10 mg.dm-3 NO3-N) in each year and in all variants. Nitrogen concentration in drainage water exceeded the MAC in five months (2006/07), in two months (2008) and in seven months (2008/09). Concentration of chlortoluron in drainage water exceeded the MAC (100 ŋg.dm-3) in five months (2006/07) and in seven months (2008/09). Maximum nitrate concentration was up to 28.42 mg.dm-3, and that of chlortoluron up to 365 ŋg.dm-3

The Influence of Zn and Cd Accumulation on the Growth and Development of Medicinal Plants in the Impact Zone of the Novocherkassk Power Station

Over the pastdecade, particular attention has been paid to studies of the chemical composition of medical plants to identify the possible negative consequences of using raw plant material polluted with heavy metals for the production of medical drugs. In our study, we analyzed the chemical composition of the medical plants growing in the impact area of the Novocherkassk power station. Specifically, the plants Artemisia austriaca, Poa pratensis and Elytrigia repenswere examined for the analysis.The content and distribution of Zn and Cd, which are most distributed in industrial emissions and belong to the first class of hazardous elements, were measured. The maximum permissible content (MPC) of Zn in the raw material of Artemisia austriaca and Elytrigia repens was found, as was the maximum content of Cd in all analyzed plants growing in the 5km area around thepower station. The plant Artemisia austriacawasfound to have Zn and Cd accumulation in itsabovegroundcomponents, while in Poa pratensis and Elytrigia repens, accumulation was in the roots. The morphobiometric parameters of the plants were mostly dependent on the soil properties, followed by the degree of technogenic load. The content of Zn and Cd in the medical drugs was higher than the MPC without visible features of heavy metal pollution and so these plants weredangerous for human health. Keywords: heavy metals, technogenic load, phytoreagents, morphometric parameter

Influence of Copper Pollution of Haplic Calcic Chernozem With Various Contents of Sand Fractions on Morphobiometric Indicators of Spring Barley

The growth and development of plants is one of the criteria for assessing the degree of soil pollution with heavy metals. Morphological and anatomical changes in test plants affected by pollutants, such as growth retardation, shoot bending, and decreased root length and mass, indicate the worsening of environmental conditions. The effect of various ratios of soil and sand polluted with copper (Cu) on morphobiometric parameters of spring barley (Hordeum sativum distichum), Ratnik variety, was studied in a model vegetative experiment. Haplic calcic chernozem was used as a substrate with different ratios of soil/sand. It was determined that an addition of sand into the soil in the amounts of 25%, 50% and 75% of soil mass resulted in the alteration of the physical properties of the chernozem, which was reflected in the morphometric parameters of the plants. The most notable changes in the parameters were observed after pollution of soil-sand substrates with Cu(CH3COO)2 in the amounts of 250 mg/kg, 500 mg/kg, 1000 mg/kg and 2000 mg/kg. The maximum growth and development retardation of the barley plants was found at the maximum content of sand and the maximum concentration of Cu. The pollutant reduced the root length and, to a lesser degree, the height of the aboveground components of the plant, which as a result, decreased the total plant biomass. Keywords: trace elements, soil, agricultural crops, particle size distributio

Solubility of Benzo[a]pyrene and Organic Matter of Soil in Subcritical Water

A dynamic subcritical water extraction method of benzo[a]pyrene from soils is under consideration. The optimum conditions for benzo[a]pyrene extraction from soil are described including the soil treatment by subcritical water at 250 °C and 100 atm for 30 min. The effectiveness of developed method was determined using the matrix spiking recovery technique. A comparative analysis was made to evaluate the results of benzo[a]pyrene extraction from soils using the subcritical water and organic solvents. The advantages of the subcritical water extraction involve the use of ecologically friendly solvent, a shorter time for the analysis and a higher amount of benzo[a]pyrene extracted from soil (96 %). The influence of subcritical water extraction on soil properties was measured the investigation of the processes occurring within soil under the influence the high temperature and pressure. Under appropriate conditions of the experiment there is the destruction of the soil organic matter while the composition of the soil mineral fraction remains practically unchanged

Assessment of the Soil Buffer Capacity in the Sea of Azov Basin Under Heavy Metal Pollution

Heavy metals (HM) are among the most hazardous soil pollutants. The intensity of accumulation and distribution of HM in soils directly depends on the ecological conditions of pedogenesis and its buffering properties. At the same time, a significant accumulation of HM in the soil as a result of anthropogenic impacts reduces the buffering capacity of the soil and its resistance to pollution. The purpose of this work was to assess the buffering capacity of soils to HM pollution in the Don River delta and the coast of the Taganrog Bay of the Sea of Azov undergoing the great anthropogenic impact. The buffer capacity of experimental soils was carried out using the Il’in’s method (1995), based on the calculation of the inactivation ability of soils: organic matter, clay fraction (particle size < 0.01 mm), carbonates, sesquioxides, and pH. The content of HM was compared with soil Clarke and the maximum permissible concentration of HM in soils accepted in the Russian Federation. It was found that the experimental soils could be ordered by buffer capacity value as following (in decreasing order): haplic chernozem ≥ alluvial-meadow light loamy ≥ solonchak > alluvial-meadow sandy and sandy loamy > sandy primitive soil ≥ stratified alluvial soil. Keywords: trace elements, contamination, impact territorie

Wetlands as nature-based solutions for water management in different environments

Wetlands are multifunctional systems performing as nature-based solutions (NBS) for water management. This paper provides an overview of natural and constructed wetlands and their potential to support the regulation of hydrological fluxes and water quality. Wetlands can modulate peak flows by storing runoff and slowly releasing it over time, with positive impacts on soil moisture. They can also change the overall water balance by influencing evapotranspiration, infiltration, and groundwater recharge. They can enhance resilience of a catchment to floods and torrents, especially with relative low return periods (<50 years), and safeguard water availability during droughts. Wetlands may remove or reduce a number of organic and inorganic pollutants (e.g., nutrients, heavy metals, hydrocarbons, pesticides) by different physical, chemical, and biological processes developed between vegetation, microorganisms, soil/growth substrate, and water. They have proven to be efficient and effective in improving the quality of water from different sources, such as runoff from agriculture and urban areas, and domestic and industrial wastewater. The overall performance of wetlands is determined by their characteristics (e.g., size, design, type of vegetation), within-catchment position, type and amount of water and pollutants, and local conditions (e.g., climate). A focus on wetlandscape, rather than individual wetlands, is required for optimal water management and maximization of other ecosystem services

Water Quality in Hydroameliorated Agricultural Areas

Three-year investigations (2007-2009) of water quality in hydroameliorated agricultural areas were carried out at the experimental amelioration field “Jelenščak” Kutina, on hydroameliorated Gleyic Podzoluvisol. Soil was drained in four different drainpipe spacing variants (15 m, 20 m, 25 m and 30 m), set up in four replications. The areas of spacing variants were: 1425 m2, 1900 m2, 2375 m2 and 2850 m2. The same crop was grown in each research year in all variants and the same agricultural management practices were applied. Winter wheat was grown in 2007 and in 2009 and soybean in 2008. Samples of drainage water were taken at drainpipe outlets into the canal. The following parameters were determined in the samples: nitrate concentration and concentration of chlortoluron. Based on the drainage water analysis, it was established that nitrate concentration as well as chlortoluron concentration exceeded the prescribed MAC values (10 mg.dm-3 NO3-N) in each year and in all variants. Nitrogen concentration in drainage water exceeded the MAC in five months (2006/07), in two months (2008) and in seven months (2008/09). Concentration of chlortoluron in drainage water exceeded the MAC (100 ŋg.dm-3) in five months (2006/07) and in seven months (2008/09). Maximum nitrate concentration was up to 28.42 mg.dm-3, and that of chlortoluron up to 365 ŋg.dm-3

A review on coagulation/flocculation in dewatering of coal slurry

Coal slurry is an essential component of mining operations, accounting for more than half of operating costs. Dewatering technology is simultaneously confronted with obstacles and possibilities, and it may yet be improved as the crucial step for reducing the ultimate processing cost. Coagulation/flocculation is used as a dewatering process that is reasonably cost-effective and user-friendly. This paper reviews application of different coagulants/flocculants and their combinations in dewatering mechanisms. In this context, various polymeric flocculants are discussed in the coal slurry in depth. Many operational parameters that influence the performance of coal slurry flocculation are also presented. Furthermore, a discussion is provided on the mechanism of flocculants’ interaction, the strategy of combining flocculants, and efficient selection methods of flocculants. Finally, coagulation/flocculation remaining challenges and technological improvements for the better development of highly efficient treatment methods were highlighted, focusing on the intricate composition of slurry and its treatment difficulties