Level Of Soil Pollution Research Articles

Heavy metal determination in agricultural soil collected from Brăila County

This is a study conducted on agricultural soil collected from village of Dudescu, Zăvoaia Commune, Însurăței City, Brăila County. In this case soybeans, sunflowers, corn and wheat have been cultivated prior the soil sampling. The soil was analyzed using an ED-XRF and the results indicated, in general, elements concentrations within normal values, indicating a good soil quality. The exceptions in this study, which have exceeded the normal legal values, were: chromium (Cr), nickel (Ni) and arsenic (As). To assess the level of soil pollution, different types of indexes were calculated such as the migration index (MI) and the ecological risk potential (RI).

Interest of the appropriate sampling strategy and analysis procedure for a representative assessment of the agricultural soil pollution level of the Pb-Zn mining site of Jbel Ressas (NE Tunisia)

Interest of the appropriate sampling strategy and analysis procedure for a representative assessment of the agricultural soil pollution level of the Pb-Zn mining site of Jbel Ressas (NE Tunisia)

Potential mobilization of water-dispersible colloidal thallium and arsenic in contaminated soils and sediments in mining areas of southwest China

Water-dispersible colloids (WDCs) are vital for trace element migration, but there is limited information about the abundance, size distribution and elemental composition of WDC-bound thallium (Tl) and arsenic (As) in mining-contaminated soils and sediments solutions. Here, we investigated the potential mobilization of WDC-bound Tl and As in soils and sediments in a typical Tl/As-contaminated area. Ultrafiltration results revealed on average > 60% of Tl and As in soil solution (< 220 nm) coexisted in colloidal form whereas Tl and As in sediment solution primarily existed in the truly dissolved state (< 10 kDa) due to increased acidity. Using AF4-UV-ICP-MS and STEM-EDS, we identified Fe-bearing WDCs in association with aluminosilicate minerals and organic matter were main carriers of Tl and As. SAED further verified jarosite nanoparticles were important components of soil WDC, directly participating in the migration of Tl and As. Notably, high pollution levels and solution pH promoted the release of Tl/As-containing WDCs. This study provides quantitative and visual insights into the distribution of Tl and As in WDC, highlighting the important roles of Fe-bearing WDC, soil solution pH and pollution level in the potential mobilization of Tl and As in contaminated soils and sediments.

Profile distribution of polycyclic aromatic hydrocarbons in coastal soils of the Lower Don and Taganrog Bay, Russia

The main regularities of pollutant distribution through the soil profile were established based on the analysis of the content of 15 priority PAHs in 29 soil sections of different soil types located in the coastal zone of the Lower Don and Taganrog Bay with different anthropogenic loads. It was shown that the total content of PAHs in the 0-20 cm layer of soils of coastal territories varies from 172 µg kg-1 to 16006 µg kg-1. In addition, according to the total pollution indicator, (Zc) determines the level of soil pollution, which varies from "not polluted" to "extremely polluted". The influence of pollution sources falls on the 0-20 cm layer of soils of different types and is especially pronounced for subordinate landscapes. With increasing sampling depth, the total PAH content decreases with the redistribution of individual compounds of the PAH group towards the dominance of low molecular weight and 4-ring compounds in the composition of the sum of 15 PAHs and depends largely on the content of organic matter and soil pH. Based on the cluster analysis results, the main factor determining the profile distribution of PAHs is the type of pollutant origin source and its intensity.

METAL ACCUMULATION ASSESSMENT IN PLANTS AND SOIL AT KUDUKU MINING SITE, NASARAWA, NIGERIA

Mining activities usually alter ecosystems through the disruption of the vegetations and the deposition of potentially toxic elements. This study investigated the soil pollution level and evaluated the phytoremediation potential of some native plant species on a mining site at Kuduku, which is located in Keana local government area of Nasarawa State. Plant samples and associated soils were collected from the mining site and analyzed for the presence of metals such as Pb, Cd, Cr and Mn. The Bioconcentration factor (BCF), Translocation Factor (TF) and Enrichment Factor (EF) were also analyzed. They were generally higher concentration of the heavy metal in most of the plants than in soils which indicates the ability of the plant to tolerate and accumulate these metals. Most of the investigated plants have potentials of been phytostabilizers or phytoextractors. Lead recorded the following plants as phytostabilizers; Acalypha indica. Copper had the following plants as good phytoextractors; Sida acuta, Fumaria parviflora, Triumfetta rhomboidea, Acalypha indica and Ageratum conyzoides. For Manganese, the phytoextractors includes: Calopogonium mucunoides, Fumaria parviflora, Ageratum conyzoides while phytostablizers includes: Triumfetta rhomboidea and Sida acuta. Most of the investigated plants had an enrichment factor (EF) greater than one which also emphasizes on the extent of metal uptake by the plants. For the majority of the plants investigated, their EF was greater than one except in few cases.

Microbiological assessment of the state of urban soils of the oil and gas region on the example of the territory of Kogalym

In the course of this work, the total numbers of heterotrophic microorganisms and the numbers of microbes participating in the nitrogen cycle (ammonifying, denitrifying, nitrifying and nitrogen-fixing ones) in urban and natural (background) soils of Kogalym were estimated. A relation between the obtained results with geochemical indicators was revealed. Our microbiological analysis showed the predominance of nitrogen-fixing microorganisms in urban soils (5.0×104 – 2.0×106 CFU/g of soil), which were on average 44 less than in natural soils. In the last ones the average number of denitrifying microorganisms was 7.0×104 CFU/g of soil, exceeding 1.3 times their number in urban soils. Based on the information obtained, microbial contents in the soils of Kogalym were established as a row: nitrogen fixators &gt; ammonifiers &gt; heterotrophs &gt; denitrifiers; in background samples: denitrifiers &gt; ammonifiers &gt; heterotrophs &gt; nitrogen fixators. According to the data of ecological and geochemical analysis, an excess of the MPC of mobile forms of heavy metals, such as Cu, Ni and Zn, was revealed in the Eastern Industrial zone of the city. A significant inverse correlation was revealed between the number of denitrifying microorganisms in the Kogalym soil microbiocenoses and the content of mobile Ni and Cu forms, which points to a possible negative effect of these metals on the development of denitrifiers. The minimum number of ammonifying, denitrifying and nitrogen-fixing microorganisms was found in the Eastern Industrial zone, especially in the soil samples that were taken near the railway. On the whole, the absence of noticeable differences in the microorganisms` content of the studied groups in urban and natural soils indicates a low level of soil pollution in Kogalym. The obtained results represent the basis for subsequent ecological monitoring of the soils in the city and adjacent oil-producing areas, forecasting the environmental consequences of anthropogenic activities in these territories.

Analysis of the spatiotemporal fields of chemical soil pollution as a basic component of urban ecosystems

The soil is a depositing medium and an indicator of geochemical load. The fulfillment of important ecosystem functions by urban soils ensures the ecological safety of urban ecosystems as a whole. The purpose of the work is to forecast soil pollution as a basic component of the urban ecosystem with a high level of technogenic load. The calculation of the spatio-temporal fields of chemical pollution of soils in the city of Kolchugino, Vladimir region, was carried out using a balance model based on ecological and analytical data utilizing the results of area surveys of soils and snow cover. The content of heavy metals of hazard classes 1 and 2 in soil and snow samples (solid and liquid phases) was determined by atomic absorption method according to standard methods. The analysis of spatio-temporal fields of soil contamination for each heavy metal is performed on the basis of map diagrams constructed using the INTEGRO GIS software-technological complex. Taking into account aerotechnogenic intake, an assessment of the degree of accumulation of heavy metals in soils and their time to reach the critical level is given. In the soils of Kolchugino, an excess of sanitary and hygienic standards (gross forms) is revealed for all the metals studied. Analysis of the data of spatio-temporal fields of soil pollution with heavy metals in the city of Kolchugino showed that the established level of soil pollution exceeding the MPC is primarily associated with the past economic activity of non-ferrous metallurgy enterprises and will remain at the same level in the near future.

Effect of manganese-rich solid waste on soil phosphorus availability applied as monopotassium and rock phosphate in two contrasting soils

Manganese (Mn) mining produces a large amount of Mn-rich solid waste contributing to soil and groundwater pollution. Adding Mn-rich waste to soils could reduce mining pollution by allowing specialised plants to take up this mineral for growth, that is, phytoremediation. However, Mn interacts with other soil major and trace minerals. The interaction with phosphorus (P), a key element for plant nutrition and growth, has received less attention. In this study, we aimed to evaluate the effects of P sources (i.e. rock phosphate and monopotassium [KH2PO4]) and application rates on the P and Mn relationships in clay and sandy soils mixed with Mn-rich waste. Soils differing in texture were incubated for 60 days at room temperature (±20 °C), and changes in available P, Mn and soil pH were determined at 0, 30 and 60 days. The addition of Mn-rich solid waste significantly decreased available soil P in both soils with the greatest reduction of 62% and 52% from the sandy soil subjected to KH2PO4 and rock phosphate, respectively. In the clayey soil, the reduction was higher for the rock phosphate source implying more P was released from the rock phosphate in Mn-rich soils. This explanation was supported by the significant positive correlation between P and Mn for both soils when P is added in the form of rock phosphate. Our results suggest that Mn-rich waste is better in clay soils subjected to rock phosphate addition. Further research is needed to control Mn solid waste pollution levels in soils using specific crops with known phytoremediation properties. Significance: South African mining and smelting processes produce a lot of Mn-rich waste as a by-product that harms the environment if not appropriately managed. The efficient use of Mn-rich solid waste in agricultural soils is poorly studied; hence, this study focused on the role of soil type and Mn-rich waste addition on phosphorus release and availability.

ECOTOXICOLOGICAL ASSESSMENT OF THE INFLUENCE OF FUEL STATIONS ON THE POLLUTION OF URBAN SOILS WITH HEAVY METALS

Problem Statement and Purpose. In modern cities, there is a rapid increase in the number of gas stations (gas stations), which are also located in residential areas of cities, causing a high level of local pollution. The growing demand for gas station services leads to the expansion of their network and maximum proximity to consumers. Among the specific features of environmental pollution near gas stations are: a high concentration of pollutants in the surface layer of the atmosphere with subsequent deposition on the soil cover and the surface of plants, the absence of dispersion of pollutants by wind currents, the presence of a significant traffic load and toxic emissions from motor vehicles during refueling, etc. Among pollutants, heavy metals have a particularly negative impact, which, due to participation in various migration cycles, pollute all vital spheres: atmosphere, hydrosphere, pedosphere. The high content of heavy metals negatively affects the main functions of living organisms and human health. Soluble forms of HM are especially toxic. The purpose of this study is to assess the ecological state of urban soils in relation to their contamination by soluble forms of heavy metals within the influence of gas stations in the city of Odessa. Data &amp; Methods. As a methodological basis, the developments presented in the scientific works of A. Antropchenko, I. Rabosh, O. Chaika and others regarding the assessment of the ecological state of the territories in the zone of influence of gas stations were used. When determining the impact of gas stations on soil pollution, the HM used both general scientific methods of research (systemic, analysis, observation) and special ones (laboratory-analytical, comparative-geographical, statistical, cartographic). Results. The conducted studies showed that urban soils within the influence of all gas stations have a significantly higher content of movable forms of HM compared to background values. Thus, the manganese content is 1.3–1.7 levels of the background content; zinc – 7–51; cobalt – 0.6–4; copper – 4–24; cadmium – 0–4; lead – 1.5–14. It was established that by the concentration factor, the most polluted are the soils with the content of zinc, copper, and lead, which is from 100% to 50% of the studied territory. 55% of the studied territory has a dangerous level of soil pollution according to the indicator of total pollution. The priority polluting elements that have the highest level of pollution intensity are zinc (Рj = 121.64) and copper (Рj = 51.01), which according to the scale of assessment of ecological danger of soil pollution belong to the fourth – very dangerous category of pollution, which can significantly influence the increase of the total morbidity of children and adults of the city. The average intensity of contamination of the investigated soils with lead (Рj = 24.92) corresponds to the second level (safe); manganese (Рj = 3.63), cobalt (Рj = 8.22) and cadmium (Рj = 9.46) – the first (permissible level of intensity of soil pollution). The correlation between the intensity of urban soil pollution and the total pollution index is 0.99, which confirms the negative impact of gas station operations on the ecological state of the city’s soil cover. Therefore, the conducted studies indicate a high probability of technogenic influence of gas stations on the soils of the studied territory and a high degree of their contamination with heavy metals, which can cause a negative impact on the health of the urban population. The danger of environmental pollution during gas station operation is currently, in our opinion, underestimated, and the issue of environmental safety of gas station operation requires further study. We believe that in order to increase the ecotoxicological safety of gas stations, it is necessary to conduct constant monitoring studies of the urban environment in order to assess the man-made load on the «soil-plant-human » system.

Soil pollution by heavy metals

An increase in the content of heavy metals in soils is an environmental threat to agriculture, as it is associated with the accumulation of toxicants in plants, which negatively affects the quality of crop production and poses a danger to human health. Each region has its own specifics, expressed by the types of pollution and trends in their changes. The article presents data on the analysis and evaluation of the categories of Primorsky Krai lands for their intended purpose, the problem of soil pollution with heavy metals is considered. On the basis of open data, the levels of soil pollution by territorial formations were determined, the main sources of heavy metal pollution were identified, unsatisfactory soil samples that did not meet hygienic standards for the content of heavy metals for ten years were analyzed, and the trend of their change was revealed. The main types of pollution, the boundaries of the spread of pollution and the differences in the presence of heavy metals such as lead, copper, nickel, zinc and manganese in the soils of territorial formations of the region are revealed. Recommendations are formulated to reduce the technogenic negative impact of industry, which will reduce the content of heavy metals in soils. Proposals have also been made to improve the monitoring system for the content of heavy metals in the soil to obtain more complete information.

Environmental quality assessment of Assuit governorate using data observation and geospatial techniques

The present paper aims to assess the quality characteristics of the available water bodies, air, and agricultural lands of Assuit governorate using spatial and laboratory analyses integrated with remote sensing techniques. To fulfill this aim, a field survey was conducted for identifying the dominant anthropogenic activities, collecting water and soil for further lab analyses of physical and chemical characteristics. Contamination indices and ecological risk of heavy metals in soil were calculated and assessed. Further, calibrated space-borne multispectral Landsat images dated 1999, 2009, 2019 and 2023 were processed to retrieve the Particulate Matter (PM10) to assess air quality over the governorate. A similar spatial distribution of PM10 over Assuit governorate was recorded during the four investigated years; 1999, 2009, 2019 and 2023. PM10 exceeded the allowable Egyptian threshold limits over the desert lands (150 µg/m3). Results reported the discharge of domestic wastewater into some irrigation canals as the main reason for elevating turbidity and Organic matter levels. Reasonable Electric Conductivity (EC) levels were recorded (277 to 1094.00 µs/cm) which showed good to permissible levels for irrigation. The investigated water parameters of the River Nile are coinciding with the Egyptian threshold limits. Remarkable fluctuations were observed in the levels of most of the soil characteristics in Assuit and the spatial analyses showed that levels of soil pollution are increasing southward which is confirmed by the positive correlation between the indicators of pollution. However, soil contamination and ecological indices were low in the whole governorate.

A Novel Approach for Predicting Heavy Metal Contamination Based on Adaptive Neuro-Fuzzy Inference System and GIS in an Arid Ecosystem

The issue of agricultural soil pollution is especially important as it directly affects the quality of food and the lives of humans and animals. Soil pollution is linked to human activities and agricultural practices. The main objective of this study is to assess and predict soil contamination by heavy metals utilizing an innovative method based on the adaptive neuro-fuzzy inference system (ANFIS), an effective artificial intelligence technology, and GIS in a semiarid and dry environment. A total of 150 soil samples were randomly collected in the neighboring area of the Bahr El-Baqar drain. Ordinary kriging (OK) was employed to generate spatial pattern maps for the following heavy metals: chromium (Cr), iron (Fe), cadmium (Cd), and nickel (Ni). The adaptive neuro-fuzzy inference system (ANFIS), known as one of the most effective applications of artificial intelligence (AI), was utilized to predict soil contamination by the selected heavy metals (Cr, Fe, Cd, and Ni). In total 150 samples were used, 136 soil samples were used for training and 14 for testing. The ANFIS predicting results were compared with the experimental results; this comparison proved its effectiveness, as a root mean square error (RMSE) was 0.048594 in training, and 0.0687 in testing, which is an acceptable result. The results showed that both the exponential and spherical models were quite suitable for Cr, Fe, and Ni. The correlation values (R2) were close to one in training and test; however, the stable model performed well with Cd. The high concentration of heavy metals was the most prevalent, encompassing approximately 51.6% of the study area. Furthermore, the average concentration of heavy metals in this degree was 82.86 ± 15.59 mg kg−1 for Cr, 20,963.84 ± 4447.83 mg kg−1 for Fe, 1.46 ± 0.42 mg kg−1 for Cd, and 48.71 ± 11.88 mg kg−1 for Ni. The comparison clearly demonstrates that utilizing the ANFIS model is a superior option for predicting the level of soil pollution. Ultimately, these findings can serve as a foundation for decision-makers to develop acceptable measures for mitigating heavy metal contamination.

Risk Assessment of Heavy Metals in Acid Soils Collected from Different Agricultural Systems in the Piedemonte Llanero in Colombia

Agricultural soils may become polluted by heavy metals as a result of receiving a significant amount of pollutants from different sources of land applications, such as fertilizers, animal manure, sewage sludge, pesticides, and wastewater irrigation. Given that information on the distribution of heavy metals (HMs) in the Piedemonte Llanero of Colombia is still quite limited, the main objectives of this work were to characterize the content of these elements and their potential pollution level in acidic soils under different agricultural systems. The hypothesis is to verify if the type of land use poses an environmental threat. To achieve these goals, the concentrations of seven metals were determined in the soils of three agricultural production systems: oil palm, pastures, and semi-annual crops. Soil contamination was evaluated based on the Geo-Accumulation Index (I-geo), contamination factor (CF), Pollution Load Index (PLI), and Nemerov Integrated Pollution Index (NIPI). One outstanding result was that the average concentrations of HMs in the collected topsoil samples were as follows: Mn (110.5 mg kg-1), Zn (31.93 mg kg-1), Cr (8.85 mg kg-1), Ni (11.68 mg kg-1), Cu (11.28 mg kg-1), Pb (9.42 mg kg-1) and Cd (0.21 mg kg-1). The results obtained from this study provide an estimation of the pollution status of HMs. Agricultural activities, especially the overuse of phosphate fertilizer, were the main source of nutrients across the study area. This information can become a fundamental tool to establish monitoring and follow-up processes for sustainable soil management in the Piedemonte Llanero. In conclusion, the present study highlights and provides specific information in a hyperhumid environment.

Assessment of Soils of Mining Regions for the Content of Heavy Metals (On the Example of Akmola Region and the Northern Part of Karaganda Region)

The work is devoted to the assessment of soil pollution by heavy metals of the first hazard class in the territory of Akmola region and northern parts of the Karaganda region. In order to study the distribution of toxic elements in soils, we studied 20 soil samples taken in the Akmola and northern parts of the Karaganda region. We used atomic emission analysis, water extraction and analysis for the content of petroleum products. Atomic emission analysis made it possible to establish the presence of 29 elements in the soil of the object, two elements were revealed, lead and zinc, the content of which is close to or exceeds the MPC. The level of soil pollution was also determined by hazard and pollution indicators in the soils of the cities of Nur-Sultan and Karaganda by the content of five heavy metals: beryllium, lead, zinc, arsenic, cadmium. According to the ecological and geochemical survey of the Akmola and northern parts of the Karaganda region, it was found that the soils of these regions can be classified as relatively hazardous in terms of danger. Recommendations are given on reducing and preventing soil pollution with heavy metals

Assessment of the risk to human health from the accumulation of heavy metals in and around the “2 July” neighborhood (Mitrovica-Kosovo, Kosovo)

Purpose. Determining the level of soil pollution with heavy metals in the “2 July” neighborhood, as well as researching the impact of pollution on the health of the neighborhood’s residents. The scope of the research was to know which age is most at risk from pollution based on the Theory of Risk Assessment, Non-carcinogenic risk assessment, and Carcinogenic risk assessment. Methodology. The soil samples in the neighborhood “2 July” were taken spontaneously. After the preparation of the samples, lead, arsenic, zinc, copper, nickel, manganese, chromium, and cadmium were determined with ICP-OES. Analytical formulas were applied for the calculation of specific indicators, which include Geo-accumulation index, Enrichment factor, Chronic daily intake, Hazard index, Carcinogenic risk assessment, the total lifetime cancer risk. They show the level of soil pollution, and the risk of heavy metals affecting human health. Findings. The results show that the content of lead, arsenic, zinc, nickel, manganese, chromium, and cadmium in the soil of the “2 July” neighborhood, in addition to copper, exceeds the values set by FAO/WHO. The value of the hazard index and total lifetime cancer risk for children for non-carcinogenic and carcinogenic risk is high, while that for adults are lower, which shows that children are more at risk. Originality. Soil pollution in the “2 July” basin comes from three industrial dumps. This pollution affects human health through inhalation, skin, and ingestion route. Practical value. The particular indicators of the influence of heavy metals on human health are discerned as a plausible notification for the inhabitants that they live in a highly harmful and polluted environment inducing health consequences.

WASTEWATER TREATMENT OF THERMAL POWER PLANTS (TPP)

An analysis of TPP wastewater, as well as technologies and equipment for their treatment, for choosing a rational mode and determining the maximum permissible concentrations of harmful substances characteristic of the energy industry before discharge into reservoirs was carried out. The compositions of the listed effluents are different and are determined by the type of thermal power plants (TPP) and the main equipment, its capacity, type of fuel, composition of the source water, method of water treatment, etc. For example, water after cooling turbine condensers and air coolers usually carries so-called thermal pollution, since its temperature is 8...10 ºС higher than the temperature of water in the water source. In some cases, cooling water can introduce foreign substances into natural reservoirs. In order to reduce the level of soil and groundwater pollution, local wastewater treatment facilities were constructed at thermal power stations. The second method is the collection of waste water in specially created containers with subsequent purification using sedimentation tanks and filters, which have anthracite or activated carbon as a filter material.&#x0D; TPP waste water is diverse and the chemical composition of each of the effluents is different. Wastewater treatment technology is complex and multi-stage and requires a large amount of various equipment.&#x0D; The ITTF of the National Academy of Sciences has developed a multi-purpose rotor-type aeration and oxidation plant (AORT), which works according to the method of discrete-pulse energy input (DPEI). This installation makes it possible to speed up the rate of heat and mass exchange of chemical reactions in water and water systems by 25-30 %. It makes it possible to reduce the duration of cleaning processes, reduce energy consumption by 2-3 times and consumption of reagents by 20-25 %. The AORT installation is used to clean sewage from iron, manganese, hydrogen sulfide, carbon dioxide, sulfates, and nitrates.

Modeling the Distribution of Radionuclides in the Air and on the Soil Surface

Mathematical and numerical methods are used to simulate physical and chemical processes when building models of pollutants dispersion in the air and on the soil surface. Based on meteorological data and information on the source of emissions, these models characterize both the primary pollutants entering the atmosphere directly and the secondary ones formed as the result of complex chemical reactions. These models are important for the air quality management system, as they allow monitoring emissions into the atmosphere, predicting their distribution, as well as developing effective strategies intended for reducing harmful substances in the atmosphere. The article presents an overview of computational methods used to simulate the pollutants dispersion in atmospheric air and on the soil surface, such as the Gaussian torch model, the Lagrangian dispersion stochastic model, and the Eulerian model of atmospheric diffusion. The practical application of the considered models showed sufficient reliability and validity of the air and soil pollution levels forecast. The simulation uses computer programs that include algorithms for solving the mathematical equations that control pollutant dispersion. The dispersion models are used to estimate the concentration of air pollutants or toxins. They can also be used to predict future concentrations under certain scenarios. They are useful for studying the pollutants that disperse over long distances and can initiate reactions in the atmosphere. Such software products are as follows: AEROPOL, AERMOD, GRAL, TAPM CSIRO, CALPUFF, HYSPLIT, etc. A method of processing information about the pollution sources and the environmental parameters, based on the HYSPLIT program, is proposed to form maps of the volume and surface activity of radionuclides. This method was applied to analyze the process of the plutonium isotopes dispersion as a result of the movement of air masses in the places of fires in April 2020 in the exclusion zone of the Chornobyl NPP, as well as the associated hazard for the population health and the environment.

Environmental impact assessment of active dumpsite in Ondo City, Nigeria: geochemical and geophysical approaches.

An assessment of the heavy metal levels associated with municipal waste in the vicinity of the Pele dumpsite, Ondo State, Nigeria, has been undertaken with the view of evaluating the environmental hazards associated with the dumpsite. A total of 23 composite soil samples were collected, measured, and analyzed for six toxic metals, and three dipole-dipole profiles were occupied within the study area. Six different pollution indices were used to evaluate the soil pollution level and ecological risk associated with the dumpsite. The 2D electrical resistivity method was used to delineate the extent of the pollution plume. The mean concentration (in µg/g) of the metals followed a descending order as Zn (75.78) > Cu (37.09) > Pb (25.96) > Cr (6.77) > Ni (5.43) > Cd (0.38). The geoaccumulation indexes revealed Cu (0.56-2.88), Pb (0.49-2.52), and Zn (0.58-2.37) as low to moderate pollutants, while Cd (1.70-6.80) was classified as a moderate-to-considerable high-level pollutant. The ecological assessment indicated moderate risk at most of the sampling points. The 2D resistivity model revealed the weathered layer, which makes up the primary aquifer units, had relatively low resistivity zones, indicating the influence of leachates from the dumpsite, and the vertical expanse of leachate movement was evaluated to be > 25m. The existence of this pollution plume poses threat to the ecosystem and the health of the surrounding population. Proper management is recommended to resolve this probable ecosystem and health issue.

Impacts of mining activities on the spatial distribution and source apportionment of soil organic matter in a karst farmland

Worldwide mining activities produce vast quantities of mine tailings, which pose a threat to soil quality, crop yields, and the regional environment in the adjacent agricultural soil, but little is known about the impact of mining activities on the SOM source and migration. In this study, soil samples of the topsoil (0–15 cm) and soil profiles (0–50 cm), as well as the potential sources samples (C3 plants, C4 plants and mining tailings) were collected from mine-contaminated karst farmland of four different pollution levels (NP, non-polluted; SP, slightly polluted; MP, moderately polluted; and HP, heavily polluted). Total organic carbon (TOC), total organic nitrogen (TON), and stable isotopic compositions (δ13Corg and δ15Norg) of soil and potential sources samples were determined. In the topsoil, the concentrations of TOC (1.9 ± 1.4 %) and TON (0.1 ± 0.1 %), and the value of δ13Corg (−25.4 ± 0.9 ‰) and δ15Norg (−3.6 ± 3.6 ‰), were not significantly different among HP, MP and SP farmland (P > 0.05). C3 plants (42.1 %–49.9 %) and mine tailings (32.3 %–40.1 %) were identified as the dominant source of topsoil SOM. In the soil profile, TOC%, TON%, δ13Corg, and δ15Norg were affected by soil depth and pollution level. TOC% and TON% in the soil profiles of NP changed slightly with soil depth, while that in the other soil profiles was decreased with the increasing of soil depth. The δ15Norg value in the SP soil dropped sharply when the soil depth was >15 cm, while that in the HP and MP soil was fluctuated and no obvious vertical pattern. Our findings provide valuable information regarding the impact of mining activities on SOM distribution and source apportionment in karst farmlands. The effects of mine tailings on SOM should be considered when the soil quality was estimated in the mine-grain composite area.

Перспективы использования метода фиторемедиации для дезактивации загрязненных радионуклидами территорий

Soil contamination with radionuclides, the main cause of which is the accident at the Chernobyl nuclear power plant, is one of the most dangerous negative environment impact factors. Phytoremediation including cultivation of «energy» crops is an effective method for decontamination of territories contaminated with radionuclides. The advantage of this approach is the possibility of using biomass as a renewable source of green energy in combination with the gradual reclamation of polluted soils. A promising crop for the purposes of phytoremediation is willow, the fast-growing species of which provide a high yield of biomass from a production plantation. A problematic issue is the safe use of willow biomass. The assessment of the conditions for the transition of radioactive cesium into willow biomass was carried out on the territories of Belarus contaminated after the Chernobyl accident. Experiments have shown that the predicted content of 137Cs in the wood of a fast-growing willow is significantly lower than the level allowed for wood fuel according to the standards established for the Republic of Belarus (740 Bq/kg). Even at the level of soil pollution at which they are removed from agricultural use (40 Ci/km2), the content of 137Cs in wood will be from 35 to 120 Bq/kg (depending on the dose of potash fertilizers).