Effect of Power Plant Ash and Slag Disposal on the Environment and Population Health in Ukraine

Background. Ash and slag disposal areas of Ukrainian thermal power plants accumulate large amounts of waste annually. Objectives. The aim of the present study was to analyze the composition of ash and slag wastes generated during combustion of coal at Ukrainian thermal power plants and the potential affects of disposal areas on the environment. Methods. A literature search was conducted using the Google search engine to access online academic publications indexed in Google Scholar, PubMed, Scopus, Clarivate Analytics (Web of Science), ScienceDirect, ResearchGate and Springer Link from 2011 in English and Ukrainian. Results. After analyzing the 25 academic articles included in the present review, the results indicated that hazardous constituents (oxides of silicon, aluminium, iron, calcium and magnesium) of ash can migrate from the ash dump surface by air and water to contaminate the atmosphere, soil, groundwater and surface water in areas located within a few kilometers from the waste site. Conclusions. By-products of the fuel and energy complex of Ukraine are potentially dangerous sources of environmental pollution. They create risks to the health of the population living in the surrounding territories. Further studies should focus on the features of pollutant transfer from ash dumps, and development of appropriate mathematical models of the pollutant migration to assess pollution levels in soil, groundwater and air. Competing Interests. The authors declare no competing financial interests.

Variational principle of the one-dimensional convection–dispersion equation with fractal derivatives

The convection–dispersion equation has always been a classic equation for studying pollutant migration models. There are certain deviations in scientific research because of the existence of the impurity of the medium and the nonsmooth boundary. In this paper, we introduced the one-dimensional convection–dispersion equation with fractal derivatives in fractal space, and established the fractal variational formula of the equation through the semi-inverse method. The fractal variational formula we have obtained can provide the conservation laws in an energy form in the fractal space and possible solution structures of the given equation. An analytical solution is obtained through the two-scale transform method and Laplace transform.

Physicochemical indicators of the influence of a lined municipal landfill on groundwater quality: a case study from Poland

The paper aims to determine the most significant physicochemical indicators of the effects that a lined landfill in southern Poland has had on groundwater quality. The results of the tests of groundwater and leachate water from the landfill for the period 2009 to 2016 were subjected to a detailed statistical analysis based on the 10 physicochemical parameters. A factor analysis was conducted considering the European Union and national requirements for landfills using analytical and statistical tools. The leachate contamination indicators from a landfill were analysed to reveal their interaction with the groundwater. The assessment indicated that there was an elevated and statistically significantly higher electrical conductivity and copper and total organic carbon concentrations in groundwater hydraulically downgradient of the landfill. The assessment also indicated that there were significant differences in the correlations between chemical parameters downgradient of the landfill and that there was a trend of increasing concentrations of some chemical constituents in groundwater. The adverse effects of the landfill were due to the deposited amount of waste exceeding 10 Mg per day. The impact was noticeable despite low and decreasing concentrations of heavy metals (Hg, Cu, Cd, Pb and Zn) in the leachate. The deterioration of the chemical state of the groundwater in the landfill vicinity could result in the extended time of pollutant migration or mass transport in the irrigated soil medium due to the limited efficiency of the leachate intake system or sealing screen after more than 20 years of landfill operation.

Exploring the Air Pollution Control Direction of Two Typical Cities, Beijing and Wuhan, from the Air Pollution under Emergency Responses during COVID-19

: During the period of COVID-19, the Chinese government implemented a series of actions to prevent the spread of the virus. It is noticed that these preventive actions have generated positive effects on air pollution in Wuhan and Beijing. And, due to the differences in city functions, geographic locations, meteorological conditions, and preventive action details between the two cities, noticeable difference is observed on how they reduced air pollution. This unfortunate incident has become a social sample for studying the industrial and livelihood activities impact on air pollution, otherwise would be highly impossible. This paper starts from observing data from NASA's real-time fine particulate matter (PM2.5) and NO2, and comparing the air pollution in this special time domain with previous years. It is discovered that both PM2.5 and NO2 have been reduced in Wuhan, while only NO2 has significant reduction in Beijing, during the COVID-19 responses. This suggests that the human activity suppression by the COVID-19 control yields different effects on different pollutants and in different cities. Possible reasons for such effects are analysed by considering the public health control levels as well as the pollutant migration, industrial activities, and the weather conditions.

GAS EMISSION FROM THE SURFACE OF THE ROCK DUMPS

Rock dumps are formed from a heterogeneous rock mass, in which, due to its crushing and mixing in the presence of air oxygen, physicochemical processes are activated. The dumps are characterized by significant emission of gases and dust into the atmosphere. Environmental models of dumps and geo-technological periods of mine operation have been developed, which are the basis for physical models of pollutant migration processes and their mathematical description. Sources of emission of gas hazards from the surfaces of dumps of coal mines are the centers of combustion of the dump mass, which contains large quantities of organic compounds. The developed model of the mass transfer of gases emitted from the combustion center makes it possible to estimate the gross and maximum one-time emissions of pollutants into the atmosphere from the surface of burning dumps.

Transport of Contamination under the Influence of Sea Level Rise in Coastal Heterogeneous Aquifer

This paper provided for the first time an experimental study on the influence of sea level rise on transport of contamination in the heterogeneous unconfined aquifer of the coastal zone. The experiments were conducted using the tank, considering the difference between sea level and inland head 1 cm for Case 1 and 2 cm for Case 2. Observed data were validated using the numerical model, which matched well with the toe length of seawater wedge and the shape of the contaminant plume. The results showed that the observed and simulated values of Cl− concentration at the sampling points increased sharply at the initial time, and then they increased slowly and tended to be stable. The seawater wedge migrated inland with time under the effects of the hydraulic gradient toward the inland and the density difference between saltwater and freshwater. The steady state length of the 50% isoline of the seawater wedge was 167 cm in Case 2, which was larger than that of Case 1. The maximum area of plume in Case 2 was 0.13 m2, larger than that in Case 1, which indicated that the velocity of diffusion of the contaminant plume increased as the sea level increased. As the velocity of diffusion increased, the time for pollutant migration to the intersection between seawater and freshwater became shorter. The maximum area and vertical depth of pollutant plume were sensitive to the hydraulic conductivity, dispersivity, and contamination concentration. The infiltration depth and range of the contaminant plume in the heterogeneous aquifer were greater than those in the homogeneous aquifer of the actual beach.