Pollution Zones Research Articles

Numerical Modeling of Dust Propagation in the Atmosphere of a City with Complex Terrain. The Case of Background Eastern Light Air

Micro-scale processes of dust distribution in the city of Tbilisi with very complex topography are modeled using a 3D regional model of atmospheric processes and numerical integration of the transport-diffusion equation of the impurity. The Terrain-following coordinate system is used to take into account the influence of a very complex relief on the process of atmospheric pollution. Modeling is carried out using horizontal grid steps of 300 m and 400 m along latitude and longitude, respectively. Cases of the stationary background eastern light air are considered. In the model, motor transport is considered as a nonstationary source of pollution from which dust is emitted into the atmosphere. Modeling of dust micro-scale diffusion process showed that the city air pollution depends on the spatial distribution of the main sources of city pollution, i.e. on vehicle traffic intensity, as well as on the spatial distribution of highways, and micro-orography of city and relief of the surrounding territories. It is shown that the dust pollution level in the surface layer of the atmosphere is minimal at 6 a.m. Ground-level concentration rapidly grows with the increase of vehicle traffic intensity and at 12 a.m. reaches maximum allowable concentration (MAC = 0.5 mg/m3) in the vicinity of central city mains. From 12 a.m. to 9 p.m. maximum dust concentration values are within the limits of 0.9 - 1.2 MAC. In the mentioned time interval formation of the high pollution zones, the slow growth of their areas and the value of ground-level concentrations take place. These zones are located in both central and peripheral parts of the city. Their disposition and area sizes depend on the spatial distribution of local wind-generated under the action of complex terrain, as well as on the processes of turbulent and advective dust transfer. From 9 p.m. to 24 p.m. reduction of dust pollution and ground-level concentration takes place. After midnight the city dust pollution process continues quasi-periodically.

Residential areas environmental safety improvement in the atmospheric air intensive pollution zones

Residential areas environmental safety improvement in the atmospheric air intensive pollution zones

Biomass quality index: Searching for suitable biomass as an energy source in Chile

A Biomass Quality Index (BQI) developed using a previously reported tool was shown to be a promising method to rank biomass suitable for solid biofuel production. The BQI was developed by selecting 12 chemical parameters to be analyzed among ten available biomasses produced in the north, central and south of Chile. Furthermore, a Parameter Quality Index (PQI) was calculated to estimate the contribution of each parameter in the BQI. The sum of all PQIs for each biomass allowed the BQI to be determined, and biomasses with lower BQIs were more highly ranked. The results showed that the first 3 ranks were dominated by biomasses collected in central Chile, hazelnut shell, cherry pits and corn cobs (BQI ≤ 16.1). Furthermore, a promising candidate that was ranked fourth place was wheat straw (BQI = 17.7), which may be able to be used the highly polluted southern zone. Meanwhile, grass and the microalgae N. gaditana were ranked last (BQI ≥ 69.5). The low BQI obtained for the studied biomasses were related to their low PQIs regarding moisture content, low trace element content, low ash percentage and high carbon content and HHV. By contrast, high BQI values were related to high PQIs for moisture, Cl, Na and K content. K had a high contribution and Cu had a low contribution in the index. Due to the difficulty of milling the top ranked biomass, further studies should include a grindability analysis or other physical parameters to complete the BQI methodology.

Quantifying fate and transport of nitrate in saturated soil systems using fractional derivative model

Natural soil systems usually exhibit complex properties such as fractal geometry, resulting in complex dynamics for the movement of solutes and colloids in soils, such as the well-documented non-Fickian or anomalous diffusion for contaminant transport in saturated soils. The development of robust mathematical models to simulate anomalous diffusion for reactive contaminants at all relevant scales presents a contemporary problem in computational hydrology. This study aims to develop and validate a novel fractional derivative, advection-dispersion-reaction equation (fADRE) with first order decay to quantify nitrate contaminants transport in various soil systems. As an essential nutrient for crop growth, nitrogen in various forms (i.e., fertilizers) is typically applied to agricultural plots but a certain fraction or excess that is converted to nitrate or nitrite will serve as a critical pollutant to surface-water and groundwater. Applications show that the fADRE model can consider both hydrological and biogeochemical processes describing the fate and transport of nitrate in saturated soil. Here “fate” is a commonly used terminology in hydrology to describe the transformation and destination of pollutants in surface and subsurface water systems. The model is tested and validated using the results from three independent studies including: (1) nitrate transport in natural soil columns collected from the North China Plain agricultural pollution zone, (2) nitrate leaching from aridisols and entisols soil columns, and (3) two bacteria (Escherichia coli and Klebsiella sp.) transport through saturated soil columns. The qualitative relationship between model parameters and the target system properties (including soil physical properties, experimental conditions, and nitrate/bacteria physical and chemical properties) is also explored in detail, as well as the impact of chemical reactions on nitrate transport and fate dynamics. Results show that the fADRE can be a reliable mathematical model to quantify non-Fickian and reactive transport of chemicals in various soil systems, and it can also be used to describe other biological degradation and decay processes in soil. Hence, the mathematical model proposed by this study may help provide valuable insight on the quantification of various biogeochemical dynamics in complex soil systems, but needs to be tested in real-world applications in the future.

Material Composition and Geochemical Characteristics of Technogenic River Silts

Abstract—The paper discusses the results of many years of studying the material composition and geochemical characteristics, conditions, and processes in the formation of technogenic river silts: a new type of modern river sediments formed in riverbeds within the boundaries and zones of influence of industrial–urbanized areas. The article examines the main sources and most important characteristics of technogenic sedimentary material flowing into rivers, as well as the geochemical conditions of technogenic alluvial sedimentation, the morphology and structure of technogenic silts, the extent of their spatial distribution in riverbeds, their grain size characteristics, and mineral and chemical composition. Special attention is paid to analyzing the group composition of organic matter in river sediments and the features of its transformation in pollution zones. The study analyzes the technogenic geochemical associations that form in silts in zones of influence of various impact sources, the features of the concentration and distribution of chemical elements, heavy metal speciation, the composition of exchangeable cations in technogenic silts and natural (background) alluvium, and the composition of silt water. Possible secondary transformations of technogenic silts and their significance as a long-term source of pollution of the water mass and hydrobionts are substantiated.

Multiyear Impact Monitoring of Pine Forests in the Central Part of the Kola Peninsula

The spatiotemporal dynamics of structural and functional parameters of undamaged pine forests and those exposed to industrial emissions containing highly aggressive sulfur compounds in combination with heavy metals, Cu and Ni, were studied. The current condition of different components of undamaged pine forests is determined by natural succession processes. Technogenic air pollution is a significant factor in determining the life state of forest stands, and in the proximity of a large copper–nickel plant in the central part of Kola Peninsula, it is main factor causing weakening and even destruction of pine forest communities. There is a clear trend of improving life condition of the pine forests, even in the zone of strong pollution, on the background of significant reduction of emissions into the athmosphere.

Emergency measure of soft isolation controlling pollution diffusion response to sudden water pollution accidents.

The frequent occurrence of sudden water pollution accidents has become a major threat to water environment safety. Although most researches have focused on constructing a pollutant source identification model and risk assessment methods for dealing with sudden water pollution accidents, a real-time, effective emergency measure for controlling pollutant diffusion, isolating and removing the pollutant, aiming at sudden water pollution accidents, has not been emphasized. Therefore, in this paper, a novel emergency approach of soft isolation was investigated to control pollution diffusion and decrease damage as soon as the accident occurred. In stage 1, the feature of pollution diffusion regarding a sudden water accident was predicted through a water quality model using computational fluid dynamics (CFD). Then, a design scheme of soft isolation was constructed in stage 2 to isolate the polluted zone and attention was paid to optimizing the parameters of soft isolation. Ultimately, the mathematical model of complete purification was formulated in stage 3 to remove the pollution from the impacted zone. The results indicated that the emergency measure of soft isolation could have significant potential to control and isolate pollution occurring in a sudden water pollution accident in the future.

ESTIMATION OF THE MAIN GAS PIPELINE OPERATION UNDER EMERGENCY CONDITIONS OF GAS LEAKAGE

The characteristics of the gas transportation system of Ukraine are presented, the emergency risks of domestic gas transportation pipeline sys­tems are established. The analysis of the accident rate of gas pipeline trans­port in Ukraine and Russia was carried out. Presented technique of deter­mining the emergency pressure in the pipeline, depending on the amount of gas losses from pipeline at the point of its leakage provides an opportunity to determine the volume of gas losses from the pipeline and to evaluate the environmental risks due to emergency situations of gas pipeline transport. This technique makes it possible to calculate the pressure at each point of pipeline under nonstationary conditions caused by changes in pressure at the beginning and at the end of the sector and the emergence of concentrated gas leakage.
 Based on the results of calculations, a graph of pressure change of the oscillatory process in the gas pipeline caused by jump of pressures at the beginning and at the end of the sector, and the presence of probable lea­kages at the determined point of the trace was constructed. The linear part of the main gas pipelines is the most dangerous object, as all emergency sit­uations are associated with emergency processes of different intensity in the form of gas leakage into the environment and in fact are dangerous when system failures appear. The process and the time period for the formation of the gas pollution zone depend on the amount of gas leakage, its intensity and depth of the gas pipeline.
 The filtration resistance of the soil as a porous medium, in particular its permeability, have a significant effect on the amount of gas leakage through corrosive orifice. As a result, there is a correlation between the amount of gas losses associated with the leakage, and the laws of its filtra­tion in the surrounding soil.
 As a result, the effect of gas filtration process in the soil in the event of leakage from pipelines has been investigated. The graphic dependence of change in pressure of the filtration resistance of the medium and the time-changing leakage which are designed for different soil characteristics is obtained.

NUMERICAL MODELING OF AIR POLLUTION FROM DUMPS

Purpose. Rock dumps are long-term sources of air pollution. A significant amount of harmful substances enters the atmosphere. Particularly intense is the pollution of atmospheric air due to dusting dumps. An important task is the development of methods for predicting the dynamics of atmospheric air pollution during the emission of harmful impurities from dumps. When developing methods for predicting the dynamics of air pollution from dumps. It is very important to create a universal model that would allow on a single computing platform to calculate the process of atmospheric air pollution for various impurities that are released from dumps. Another important problem is the choice of the place for optimal placement of future dumps in order to minimize their negative impact on the environment. Methodology. Numerical modeling of the formation of atmospheric pollution zones near rock dumps is based on the application of the equation of turbulent dispersion of an impurity in the atmosphere. To solve the problem of choosing the rational location of the dumps, the conjugate equation is used. Numerical integration is carried out using an implicit difference scheme. Findings. Numerical models are developed. The first numerical model allows one to evaluate the effect of rock dumps on air pollution. The second numerical model allows, on the basis of a one-time calculation, to determine the rational location of the future dump from the point of view of its minimal impact on air pollution. Originality. Two numerical models are proposed that are based on the application of the turbulent diffusion equation and the conjugate equation. These models make it possible to quickly determine the effect of rock dumps on air pollution. The models take into account the convective transport of the pollutant, atmospheric turbulent diffusion, the intensity of the emission of impurities from the dump. Practical value. The developed numerical models are implemented in the form of program codes. These program codes can be used when performing serial calculations on computers of low and medium power, i.e. computer technology, which is available to organizations involved in environmental issues in technologically saturated regions. When carrying out calculations based on the constructed numerical models, typical initial data are used regarding the intensity of the emission of impurities from dumps, weather conditions characteristic of a specific region of the country.

COMPUTER MODELING OF AIR POLLUTION IN CASE OF DUST CLOUD MOVEMENT IN OPEN PIT MINE

Purpose. Explosions in open pits lead to the formation of dust clouds. These clouds lead to intense air pollution. An important task is the development of methods for predicting the dynamics of atmospheric air pollution during explosions in open pits. The purpose of this work is development of a numerical model to predict atmosphere pollution after explosion in open mine pit. The task is to develop a numerical model that would allow for the calculation to take into account the geometrical shape of the open pit mine, the parameters of the meteorological situation (wind speed, atmosphere), the shape of the dust cloud that is formed in the open pit mine at the site of the explosion. Methodology. Mathematical modeling of dust cloud dispersion during an explosion in an open pit mine is based on the use of fundamental equations of aerodynamics and mass transfer. The airflow velocity field in the open pit mine is modeled using the Laplace equation for the velocity potential. The formation of the concentration field of dust is modeled on the basis of the equation of convective-diffusion dispersion of an impurity. For numerical integration of modeling equations, difference schemes are used. The Laplace equation for the velocity potential is numerically integrated using the Richardson method. For the numerical integration of the convective-diffusion dispersion equation for an impurity, an implicit difference splitting scheme is used. Findings. A CFD model has been developed that allows you to calculate the formation of pollution zones during the movement of a dust cloud in the open pit mine. A feature of the developed model is the speed of calculation. For practical use of the developed model, standard input information is required. Originality. In contrast to the existing models in Ukraine, the developed numerical model allows taking into account the geometrical shape of the open pit mine and the geometrical shape of the dust cloud when making predictive calculations to assess the level of air pollution caused by explosions in open pits. Practical value. The developed numerical model can be implemented on computers of low and medium power. For practical use of the numerical model, standard information on meteorological conditions in open pit mine is required. The numerical model can be used for environmental assessment of the effect of explosions in open pit mine on environmental pollution and work areas.

X ray microanalysis of northeastern Quintana Roo aquatic biota, Mexico: evidence of hazard metals presence

The microanalysis of elemental composition by means of energy dispersive X-ray is a biomonitoring tool to identify inorganic pollutants, owing to this the present report studies the lorica of diatoms, dinoflagellates, rotifers, cladocerans, copepods and fish scales by means of scanning electron microscopy/energy dispersive X-ray spectrometry in view of finding out which toxic metals are bio-accumulating in the aquatic ecosystems of northeastern Quintana Roo, Mexico. The study was carried in the coastal zone, where samples were collected in 16 exposed water bodies: dolines, mangroves and lagoons from 2014 to 2016. Later on, the microanalysis was undertaken for the most abundant organisms. Our results for lorica and scales evince the presence of essential trace elements and toxic metals: Ag, Al, Br, Cd, Cu, Fe, Hg, Pb and Zn. Furthermore, interpolation maps of the northeastern zone of Quintana Roo were produced for Cd, Cu, Hg, and Pb, in which critical pollution zones with Cd, Hg and Pb are pinpointed; such elements are deemed toxic for human and aquatic ecosystems’ health. As a conclusion, X-ray microanalysis in lorica and scales of species native to the State is a good indication of the presence of metals in water.

ANALYSIS OF THE ECOLOGICAL STATE OF FOREST ECOSYSTEMS OF THE EASTERN PODILLIA

On the basis of literary sources, the article provides a brief analysis of the ecological state of the forest ecosystems of the Eastern Podillia. Today, one of the main problems of Ukrainian forests is the low level of pollution. There are many environmental factors that reduce forest area, such as forest fires, pests and diseases, natural disasters, illegal logging. Forests dry up, they are ill, often they are uncontrolledly crushed, so today the average rate of pollution in the country - 15.7%, while in order to reach the optimal indicators this percentage should be at level 20. And this means that in the near future it is necessary to plant the young forest about 2 million hectares of Ukrainian lands. In Ukraine, forests are in the zone of industrial pollution, and their general condition does not meet ecological and economic requirements. Particularly relevant forest problems of Ukraine have come about due to the formation of catastrophic floods on the rivers of the Carpathian region, large-scale manifestation of erosion processes, radioactive contamination of the territory, etc. Therefore, in order to increase forest productivity, improve their useful properties and meet the needs of the community in forest resources, reproduction, protection and protection of forests are important. Forests are extremely important. Forests are a national treasure, and in their destination and location, they mainly perform water protection, protection, sanitation, health, recreation, aesthetics, education, other functions, and provide a source for meeting the needs of the community in forest resources.

Pollution indicandum and marble waste polluted ecosystem; role of selected indicator plants in phytoremediation and determination of pollution zones

Abstract The absence or presence of particular plant species indicates specific level of pollution. It was hypothesized that the marble waste polluted ecosystem also host specific plant indicators that can grow, survive and tolerate more successfully than others and can be utilized in better managements of such systems. The current research work was therefore, conducted to determine the indicators of marble polluted region of Buner, Pakistan. Ecological techniques using varying sized quadrats i.e., 1 × 1 m2, 5 × 2 m2 and 10 × 2 m2 for herbs, shrubs and tree species were used respectively. Standard protocols were used to prepare soil samples and plant parts (root, leaf and shoot) for Atomic Absorption Spectrophotometry. Indicator i.e., Populus alba L., Arundo donax L., Erigeron canadensis L and Morus alba L. were identified via Indicator Species Analyses (ISA) in various polluted zones. All the collected data were put in MS Excel for analyses in PCORD through Cluster Analysis (CA), Two Way Cluster Analysis (TWCA) and ISA. CANOCO software was used to examine the impact of miscellaneous environmental variables in zonation via both direct and indirect gradient techniques i.e., Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA). A total of 102 plant species belonging to 95 genera and 48 families were recorded in the marble waste polluted ecosystem. CA and TWCA through Jaccard Distance measurements and Wards Linkage methods gave rise to 3 major polluted zones. These zones were i) Heavily Polluted Zone (HPZ), ii) Moderate Polluted Zone (MPZ) and iii) Less Polluted Zone (LPZ). The recorded values of Biological Concentration Factor (BCF), Translocation Factor (TF) and Bioaccumulation Coefficient (BAC) for analyzed heavy metals i.e. Fe, Mg, Ca, Na and Cu in root and shoot of P. alba L., A. donax L., and M. alba L. showed that these species were significant phytostabilizers and E. canadensis L. was phytoextracters and hence best indicandum of marble waste polluted ecosystems. It was concluded that among all the measured environmental variables, higher phosphorus level, higher pH, moderate potassium and lower electrical conductivity (EC) had significant effects (p 0.05 ) on the functions of these indicators as phytoremediaters. It is recommended to develop green belts of these indicators around the marble industrial areas for the better management and hazardous free environment.

Bioindication of soil pollution in the delta of the Don River and the coast of the Taganrog Bay with heavy metals based on anatomical, morphological and biogeochemical studies of macrophyte (Typha australis Schum. & Thonn).

The results of biogeochemical and bioindication studies on the resistance of natural populations of macrophyte plant-cattail (Typha australis Schum. & Thonn) on the coast of the Taganrog Bay of the Sea of Azov and the sea edge of the Don River delta with regard to local pollution zones are presented. Plant resistance has been assessed through manifestation of their protective functions in relation to heavy metals. An excess in the lithospheric Clarkes and MPC in Zn, Cd and Pb in Fluvisols has been found. The total index of soil pollution (Zc) has made it possible to identify areas with different categories of contamination within the study area exposed to human impact. High mobility of Zn, Cd, Pb, Cr and Ni in Fluvisols has been revealed, which is confirmed by the significant bioavailability of Zn, Cr and Cd that are accumulated in the macrophyte plant tissues. The absorption of heavy metals by cattail plants is allowed for both the soil and the water of the nearby reservoir, where aquatic systems are a kind of "biological filter" contributing to water purification from pollutants. The impact of the environmental stress factor has been found to be manifested not only in the features of heavy metal accumulation and distribution in plant tissues, but also at the morphological and anatomical level according to the type of prolification. Changes in the cell membranes as well as in main cytoplasmic organelles (mitochondria, plastids, pyroxis, etc.) of the root and leaf cells have been identified, the most significant changes in the ultrastructure being noted in the tissues of leaf chlorenchyma. It is assumed that the identified structural changes contribute to slowing down of the ontogenetic development of plants and reduction in their morphometric parameters when exposed to anthropogenic pollution. Therefore, cattails can be effectively used as biological indicators while determining environmental pressures.

Mapping and Analysis of Vegetation Spectral Reflectance in Oil and Gas Seepage Polluted Zones Using Six Vegetation Indices

The growth and health of vegetation may be adversely influenced by oil and gas pollution or leakage. Thus, when an environment is contaminated with oil and gas pollution, growing vegetation often exhibit signs of stress. Satellite remote sensing has proven to be an effective tool and approach to detect and monitor vegetation health and status in oil and gas polluted zones. Previous studies have adopted vegetation indices which are obtained from remotely sensed satellite data to monitor vegetation health. This study is aimed at demonstrating the potential of vegetation spectral techniques for detecting and monitoring of oil and gas pollution from Landsat 8 OLI/TIRS remotely sensed data. To determine the influence of oil and gas pollution on vegetation reflectance, few polluted sites were analyzed and their reflectance were compared in all the TM bands against the non – polluted sites. The mean and standard deviation reflectance of each of the bands in two groups of sites and t – test are calculated to determine if there are any significant differences between the reflectance from the polluted and non – polluted sites. Thus, the study shows that in all the spectral bands, the vegetation reflectance from polluted and non – polluted areas exhibit small significant difference with a p-value >0.005. To further analyze the impacts of oil and gas on vegetation, six spectral indices including NDVI, SRI, MSAVI2, SAVI, ARVI2 and EVI2 were utilized. SRI, SAVI and EVI2 showed no significant relationship between polluted and non-polluted areas with a p-value > 0.05 higher than the alpha level of 0.05 and the calculated t - test value is lower than the t-critical value of 2.09 while NDVI, MSAVI2 and ARVI2 showed a significant relationship between the polluted and non-polluted areas. Keywords: oil and gas pollution, Ground Truthing, Vegetation Indices, Landsat 8 OLI/TIRS, Remote Sensing and Vegetation Cover. DOI : 10.7176/JEES/9-7-05 Publication date :July 31 st 2019

ESTIMATE OF THE ENVIRONMENTAL CONDITION OF CITIES ON THE BASIS OF BRYOPHYTE COMMUNITIES

The results of biomonitoring studies in urban ecosystems of Myrhorod and Luben cities (Poltava region) by brioindication methods are presented. Ecological coefficients of bryophytes were determined and calculations of the Air Purity Index (API) were performed. Totally five zones in the cities mentioned are found. They are differentiated by the degree of environmental pollution.The first zone is heavily polluted (API = 0–0.9); zone of sufficient contamination (API = 1,0-2,6); medium contaminated area (API = 2.7-4.9); poorly contaminated area (API = 5.0-10.0); unpolluted area (API > 10).The enclosed zoning maps of cities indicate their uneven contamination. In the city of Myrhorod, the heavily and sufficiently contaminated area is sparsely expressed and confined to the central Gogol Street and its intersection with other streets. at least in the central part. The unpolluted area with islets is located in the eastern and southeastern part of the city, and its main area is concentrated on the territory of the forest park zone of the territory of the resort “Myrgorod”, which is correlated with the valley of the river Khorol. The main area of the city is in a lightly polluted area, which, in our opinion, contributes to the development of the resort town. In Lubny, the heavily and sufficiently polluted zones occupy much larger areas than in Myrhorod, and they are confined to the main motorways of the city. The poorly polluted area occupies a small area throughout the city, its largest areas being confined to its northern part. The unpolluted area occupies much smaller areas in Lubny than in Myrhorod and is concentrated mainly in the southwestern part of the city, where the woodlands of its main green zone are located: Morozovskaya and Zhovtneva Reserves, as well as occurring with separate inclusions in the east and the west of the city.The main square of the city of Lubny, unlike the city of Myrhorod, is in the middle-contaminated zone, which is obviously connected with the significant influence of the international highway Kiev - Kharkiv - Rostov on the Don, as well as the developed transport network of roads of local and regional importance. The flow of air is also of great importance in Lubny, which is mostly dominated by the international M-03 highway.

Hydrogeochemical processes regulating the spatial distribution of groundwater contamination, using pollution index of groundwater (PIG) and hierarchical cluster analysis (HCA): A case study

Groundwater quality investigation has been carried out from a sub-urban area of Visakhapatnam, Andhra Pradesh, India, to find out the controlling processes of groundwater chemistry spatially, leading to groundwater contamination. The groundwater quality is characterized by fresh to brackish and hard types, with Ca2+ > Na+ > Mg2+ > K+: HCO3− >Cl− >SO42− >NO3− facies. According to the pollution index of groundwater (PIG), most of the study area (70%) comes under the insignificant pollution zone and the rest (30%) under the low pollution zone. The chemical variables from the hierarchical cluster analysis (HCA) demonstrate three distinct clusters, which measure TDS in Cluster I, HCO3− and TH in Cluster II, and Cl−, Na+, Ca2+, SO42−, Mg2+, NO3−, K+ and pH in Cluster III, representing the salinity, carbonate hardness and pollution processes, respectively. Groundwater samples from the HCA are categorized into three groups, which show less, moderately and highly mineralized groundwater qualities in Group I, II and III, respectively, depending upon the geogenic processes and the anthropogenic activities. The groundwater samples of Group III influenced by low pollution activity, which support the low pollution zone of PIG, establish the fact that the controlling processes of groundwater chemistry lead to groundwater contamination spatially. The present study helps taking the strategic management measures at specific sites for sustainable development of groundwater resources.

ATMOSPHERE PROTECTION FROM POLLUTION IN ACCIDENTAL SITUATIONS AT CHEMICALLY HAZARDOUS OBJECTS

Purpose. The work involves the development of numerical models to assess the effectiveness of the air curtain usage near the building in the event of chemical pollution. Methodology. To describe the process of dispersion of a chemically hazardous substance, emitted in emergency situations, the three-dimensional equation of impurity mass transfer in atmospheric air is used. To calculate the air velocity field near the building in the presence of an air curtain, a potential-flow model is used. The modelling equations take into account the velocity field of the wind flow, atmospheric diffusion, and the intensity of the emission of a chemically hazardous substance into the atmosphere. For the numerical integration of the mass transfer equations, implicit difference schemes are used. The complex of programs was created to solve the problem of calculating pollution zones near buildings in the presence of an air curtain. The application of the developed model allows you to quickly calculate this field of concentration of a chemically hazardous substance near the building in the presence of an air curtain. Findings. Numerical models for calculating the aerodynamics of the air flow and the concentration field near the building when using an air curtain were constructed. They can be used to carry out operational calculations of the size, intensity of pollution zones, which are formed in the atmosphere during the emission of chemicals at industrial sites. The developed numerical models can be implemented on computers of low and medium power, which allows it to be widely used for solving problems in developing an emergency response plan (ERP). For practical application of the developed numerical models, standard input information is required. Authors present the results of a laboratory experiment. Originality. Effective three-dimensional numerical models are proposed for estimating the level of atmospheric air pollution when emission of chemically hazardous substances into the atmosphere and using an air curtain near an industrial building. Models allow you to quickly calculate the effectiveness of the air curtain usage. Practical value. The developed numerical models allow solving applied problems arising in the development of ERP for chemically hazardous objects.

Monitoring of aerial technogenic zone of influence of the production facility as a tool of ecological engineering

The actuality of the extended research of spatial factor of formation of the territory of the maximum long-term air pollution, as a prerequisite of health risks to residents in industrial cities and the corresponding indicator is specified. Due to the heterogeneity of the dispersion conditions, the real boundaries of the zones of negative impact of emission sources turn out to be more controllable, and due to the overlapping and layering of contamination fields, the concentration of impurities may exceed the norms. It was proposed to correct the known index of the ratio of the industrial site area and the pollution zone and use it to calculate the average annual area of the such fields, taking into account key meteorological parameters. Recommended correction factors that characterize the proportion of polluted urban areas, highlighted the key elements of the industrial hub as objects of environmental engineering and specified the direction of search for organizational and technical solutions.

Fresh underground light non-aqueous liquid (LNAPL) pollution source zone monitoring in an outdoor experiment using cross-hole electrical resistivity tomography.

Real-time monitoring of source zone of light non-aqueous liquids (LNAPLs) is important for preventing accidental pollution and taking effective underground pollution remediation measures. As a high-precision monitoring technology, cross-hole electrical resistivity tomography (CHERT) has been widely used to obtain static information regarding underground stratigraphic structures and dynamic information regarding fluid motion. The time-lapse data processing method can be used to obtain pollution zone dynamic change information. Since the leakage rate directly affects the diffusion range of pollution, this study simulated the initial evolution process of LNAPL pollution source regions under two different leakage rates. The time-lapse monitoring of the above process was performed using CHERT. The test results show that CHERT can be used to observe the migration of LNAPLs and the initial evolution of the contaminated area. Differences in leakage rate will result in variation in soil wettability and fluid distribution, which will cause changes in soil resistivity in the corresponding region. The low-saturation LNAPL-contaminated area may exhibit low-resistivity characteristics and is easily overlooked in field investigations. In addition, the degree of contamination in the saturated zone can be quantitatively evaluated by CHERT; however, the pollution range and oil saturation value determined by CHERT are underestimated. The results showed the electrical variation characteristics of the initial evolution process of the fresh pollution source area and provide data that will enable early warnings of LNAPL leakage. This shows that CHERT is a promising tool for monitoring LNAPL pollution source leakage even if further research is needed to fully understand the effect of hydrological processes on electronic signals.