Groundwater Pollution Problems Research Articles

Analysis of groundwater pollution caused by mine leachate leakage considering natural impermeable layer

Aiming at the problem of groundwater pollution caused by mine leachate leakage, a numerical model of saturated-unsaturated groundwater is established by using FEFLOW software, and the spatial and temporal distribution of pollutants in vadose zone and aquifer is predicted, in this paper. The results show that the impervious layer of natural clay can slow down the entry of pollutants into the aquifer and reduce the impact of pollutants diffusion on the aquifer. This paper can provide some references for mine groundwater pollution prevention and control.

Groundwater pollution: Occurrence, detection, and remediation of organic and inorganic pollutants

Groundwater pollution is a result of natural and anthropogenic activities. While the elevated levels of various inorganic constituents could be attributed to natural processes, such as geological weathering and aquifer characteristics, many times, anthropogenic activities also substantially pollute the groundwater. On the contrary, the occurrence of organic pollutants is primarily due to various anthropogenic activities. Extensive groundwater mining, the hydraulic connection between groundwater and other surface water bodies, and leaking underground buried infrastructure also contribute to groundwater pollution. Water resources are scarce commodities, and preserving groundwater quality is of critical concern. This paper documents instances of groundwater quality impact during the year 2019 due to both natural and anthropogenic activities throughout the world. PRACTITIONER POINTS: Groundwater pollution problems reported during the year 2019 are reviewed and documented. Occurrence of organic, inorganic, and microbial pollutants in groundwater is reported. Remediation technologies for selected inorganic pollutants are reviewed and documented.

Compact finite-difference method for 2D time-fractional convection–diffusion equation of groundwater pollution problems

In this work, we provide a compact finite-difference scheme (CFDS) of 2D time-fractional convection–diffusion equation (TF-CDE) for solving fluid dynamics problem, especially groundwater pollution. The successful predication of the pollutants concentration in groundwater will greatly benefit the protection of water resources for provide the fast and intuitive decision-makings in response to sudden water pollution events. Here, we creatively use the dimensionality reduction technology (DRT) to rewrite the original 2D problem as two equations, and we handle each one as a 1D problem. Particularly, the spatial derivative is approximated by fourth-order compact finite-difference method (CFDM) and time-fractional derivative is approximated by $$L_{1}$$ interpolation of Caputo fractional derivative. Based on the approximations, we obtain the CFDS with fourth-order in spatial and $$(2-\alpha )$$ -order in temporal by adding two 1D results. In addition, the unique solvability, unconditional stability, and convergence order $${\mathscr {O}}(\tau ^{2-\alpha } + h_{1}^4 + h_{2}^4)$$ of the proposed scheme are studied. Finally, several numerical examples are carried out to support the theoretical results and demonstrate the effectiveness of the CFDS based DRT strategy. Obviously, the method developed in 2D TF-CDE of groundwater pollution problem can be easily extended for the other complex problems.

Ecological assessment of the condition of soil and field crops cultivation with application of mineral fertilizers in the conditions of the northern steppe of Ukraine

In order to obtain a higher level of crop yields in crop rotation, there is a need to increase the application of fertilizers and pesticides, which, in turn, creates environmental problems of soil and groundwater pollution by harmful chemical elements and compounds. The purpose of the study was to study the influence of fertilizer systems with different tillage systems on the accumulation of heavy metals and nitrates in the soil and the main products of field crops. Bookmarking and conducting field experiments were carried out in accordance with generally accepted methods of research. The maximum increase in grain yield from the use of N48Р18K18 on the shelf tillage system was – 0.25 (8.7%), grain units – 0.36 (9.9%), feed units – 0.41 (10.3%), digestible protein – 0.02 (5.0%) t/ha of crop rotation area. The use of N48Р18K18 in a differentiated tillage system increased grain yield by 0.34 (12.2%), grain units – 0.49 (13.5%), feed units – 1.12 (28.0%), digestible protein – 0.06 (13.6%) t/ha of crop rotation area. The use of N48Р18K18 in crop rotation with a shallow (mulching) tillage system gave an increase in grain yield by 0.38 (13.6%), grain units – 0.51 (14.2%), feed units – 0.57 (14.5%), digestible protein – 0.07 (15.9%) t/ha of crop rotation area. According to the results of research, the highest increases in mineral fertilizers in terms of productivity were characteristic of a shallow (mulching) background with a characteristic stricter nutrient regime. Our research has not found a significant increase in the content of heavy metals and nitrates in the main and by-products of field crops when applying mineral fertilizers, because their content in the products was within acceptable concentrations. The content of nitrates in the grain of different crops ranged from 18 to 40.4 mg/kg at a maximum concentration limit of 300 mg/kg. High culture of agriculture, improvement and development of new, more effective technologies of application of fertilizers in crop rotation and under each field crop taking into account soil and climatic conditions of the region, biological features of cultures and grades, specialization of crop rotations, etc. prevent environmental pollution. Rational use of mineral and organic fertilizers helps to increase soil fertility and is a major and indispensable factor in significantly increasing plant productivity and crop quality, maintaining an active biological and economic balance of nutrients without contamination of the environment with nitrates and heavy metals.

Physico-chemical Characteristics of Ground Water Quality in District Satna (M.P.)

The problem of ground water pollution in several parts of the country has become so acute that unless urgent steps for detailed identification and abatement are taken, extensive ground water resources may be damaged. The quality of ground water depends on a large number of individual hydrological, physical, chemical and biological factors. Generally higher proportions of dissolved constituents are found in ground water than in surface water because of greater interaction of ground water with various materials in geologic strata. The work done on ground water of Satna District covering various inorganic non metallic constituents covered are pH, TS, TDS, TSS, TH, DO, BOD, COD, Alkinity, Conductivity.

Analysis of the Groundwater Resource Pollution of Coal-Fired Power Plants and Its Impact on Geotechnical Engineering Properties by Numerical Simulation Technology

Objective: The objective is to investigate the impact of groundwater resource pollution of coal-fired power plants and its impact on the properties of geotechnical engineering based on numerical simulation technology, thereby proving the effectiveness and superiority of numerical simulation technology in preventing groundwater resource pollution and forecasting the related information, which would provide direction and guidance for the treatment and management of groundwater resource pollution. Method: First, the regions to be investigated are divided and generalized. Then, relevant experiments are carried out for the calculations of hydrogeological parameters to establish the hydrogeological conceptual model. Next, the real-time water level data recorded by the observations are used to identify and verify the model effectively. Afterward, the numerical simulation of groundwater solute transportation is carried out again. During the process, the establishment of the groundwater quality model is the focus, followed by the application of numerical simulation technology to forecast the environmental impacts of groundwater pollution, including the forecasting of groundwater environmental pollutions caused by Chemical Oxygen Demand (COD) leakage, ash yard, and power plants. Results: Through the application of numerical simulation technology, the current information about groundwater pollution, such as the scope of impact and the movement law of pollution, can be understood clearly and timely. Conclusion: By applying the numerical simulation technology in forecasting groundwater pollution, the groundwater pollution problems can be prevented effectively, which offers great help to the correct and reasonable operation and development of coal-fired power plants, which provides a significant reference for the preventive treatment of groundwater pollution.

The Impact of Poor Waste Management Practice on the Campus Students: The Case of Gondar University of “Tewodros” Campus, Ethiopia

This study aimed to examine the impact of poor solid waste management on students’ health care at the Gondar University of campus. The study used a mixed-method approach. To recruit sample respondents, both probability and non-probability sampling methods have been employed. In the meantime, the study revealed the sources of solid waste, It is understood that the poorly collected and managed solid waste of the study area, due to the lack of necessary materials and facilities for waste collection, lack of laborers engaged in street sweeping, and daily removal of solid waste, is now becoming the major cause of environmental problems such as surface and groundwater pollution problems. Besides, the student's health office personnel in the interview approached the general health status of the on the campus for this year. As a result, the most common diseases on the Tewodros campus are dysentery, the common cold, and typhoid. Therefore, there should be a students committee at the campus level to control illegal dumping and to develop practice and habits of poor waste handling and disposal in the community, and there must be apparent regulation and policy frameworks that prohibit poor waste management.

Soil sodicity originating from marginal groundwater

AbstractSoil salinity and sodicity are among the oldest soil and groundwater pollution problems and are widespread across the globe. Where salinity affects crop water uptake and yield, sodicity may additionally cause poorly reversible soil structure degradation and a severely reduced hydraulic conductivity. We use the model HYDRUS‐1D to simulate sodicity development in soils with shallow, Na‐rich groundwater under a normal weather regime with distinct dry seasons. Attention is given to the impact of a sudden fresh water input on the formation of a sodic layer. The complex interplay between soil chemistry, soil physics, soil mechanics (as far as swell–shrink behavior is concerned), and fluctuating atmospheric conditions results in a remarkably regular relation between depth, location, and severity of a sodic layer that forms within the soil as a function of rainfall intensity. A threshold behavior is observed: sodic layer formation is absent at rainfall intensities below this threshold, whereas sodic layer thickness and hydraulic conductivity reduction increase rapidly with intensities exceeding this threshold. This is the case even for different soil types and groundwater depths. Field observations agree with our simulations: the properties of the layer with sodicity‐induced structure degradation are more strongly developed, as this layer is situated at a shallower depth. The implementation of hydraulic conductivity reduction as a function of exchangeable Na percentage and ionic strength in HYDRUS‐1D can be improved towards a smooth reduction function, changing soil physical parameters due to swelling and dispersion of clay and reconsideration of the reversibility of sodicity development.

Modeling of transport of first-order reaction networks in porous media using meshfree radial point collocation method

First-order reaction networks are often encountered in groundwater pollution problems. The members of the network transform/degrade from one species to another. In this paper a strong form meshfree numerical method named radial point collocation method (RPCM) is introduced to model such reactions. In the proposed method, the entire domain is decomposed into a number of overlapping local support domains surrounding each node. The concentrations of species at each node and its directional derivatives are approximated using multiquadrics radial basis functions (MQ-RBF) within the local support domain. 1D models are verified against existing analytical solutions. Further, the 2D model simulations are compared with widely used RT3D (Reactive Transport in 3 Dimensions) for a benchmark problem. Sensitivity analysis is also performed for model parameters. The proposed model solves species-wise governing equations and boundary conditions without operator splitting, unlike the popular grid/mesh-based models. The RPCM-based models are found to be very effective in modeling first-order reaction network problems.

Assessment, formation mechanism, and different source contributions of dissolved salt pollution in the shallow groundwater of Hutuo River alluvial-pluvial fan in the North China Plain.

With rapid urbanization and industrialization processes, the problem of groundwater pollution under the influence of various human activities has become increasingly severe in most developed areas of China. However, the problem of dissolved salt pollution caused by increasing concentrations of conventional ions is often overlooked and easier to be seen as a high background of natural formation rather than pollution. The Hutuo River alluvial fan in North China was selected as the study area; dissolved salt pollution is evaluated based on the factor analysis method (FA); groundwater exploitation, pollutant input, and the attenuation of the vadose zone were discussed to explain the salt pollution; the formation mechanism and different source contributions were also explored. The results show that the total hardness (TH) and nitrate are the main contributing indicators of salt pollution in the Hutuo River alluvial fan. The long-term overexploitation of groundwater promoted the leaching and nitrification reactions, resulting in a large area of moderate to strong salt pollution in the top unit of the alluvial fan, which accounted for 51.6% of the salt pollution according to the multivariate regression model. In addition, the input pollution generated by various types of pollution sources along with rainfall infiltration is also an important driving factor. The surface pollution load and hydrogeological conditions affected the cation exchange and leaching, resulting in a point distribution of strong salt pollution, with a contribution rate of 37.6%. The analysis of the factors that affect salt pollution and the specific contributions in different regions cannot only help decision-makers understand the causes of water quality deterioration but also propose solutions in a targeted manner.

Berkeley pit and its impact on the environment

The article tells about the Berkeley Pit and its environmental impact. The main chemical characteristics of mine water and water treatment systems are outlined. Possible ways of dealing with problem of ground water pollution are discussed.

Control Effects of Hydraulic Interception Wells on Groundwater Pollutant Transport in the Dawu Water Source Area

Based on the comprehensive analysis of hydrogeological data of the Dawu water source in Zibo city, the Modflow module in Groundwater Modeling System is used to carry out three-dimensional geological modeling of the Dawu water source, and the flow field model and solute transport model of the Dawu water source are established. Aiming at the problem of groundwater pollution in the key polluted area of the Hougao region—the Dawu water source—the pollutant transport model is established to explore the process of pollution transport. There are many types of groundwater pollutants in the Hougao area. Among them, ammonia nitrogen, chloride, petroleum, and benzene exceed the standard most seriously. In order to facilitate the research, we selected typical pollutants for in-depth study. The ammonia nitrogen is used as the control index of domestic and industrial waste water in the policy documents of pollution emission. It can show the specific situation of industrial waste water and domestic waste water pollution changing with time. Thus, the ammonia nitrogen with a higher exceeding standard is selected as the pollution factor in this simulation. Pollutant transport under the conditions of strong pumping and stop pumping is simulated. It is found that the pollutant is effectively controlled due to the pumping and discharging effects under the action of strong pumping, from 4 to 5 times exceeding the standard to slightly exceeding the standard. However, there is still a trend of migration to the eastern water supply area. After the pumping is stopped, the pollutant quickly migrates to the Xixia centralized water supply area, causing serious pollution to the water supply area. Finally, four other hydraulic interception wells are set up in the 500 m east of Hougao’s four wells to further control the pollutant transport. When hydraulic interception wells and strong pumping wells are used together, the scope of ammonia nitrogen pollution is basically controlled near the interception wells, and it does not continue to spread to the eastern water supply area. The maximum monitoring value of pollution is 0.11 mg/L, which is controlled within the standard limit of three types of groundwater, and the pollutant control effect is the best, providing certain reference for similar pollution control work.

Occurrence and distribution of organic and inorganic pollutants in groundwater.

Depletion of groundwater resources and continued decline in overall groundwater quality is a cause of concern because large human population around the world uses groundwater as a source of drinking water. This paper presents a comprehensive review of studies published in the year 2018 that documented issues of groundwater pollution, sources, and distribution reported from across the world due to anthropogenic, hydroclimatogical, and natural processes. Groundwater pollution due to organic contaminants focuses particularly on pesticides, herbicides, and contaminants of emerging concern. Pollution due to inorganic pollutants such as arsenic and other heavy metals is also reviewed with particular emphasis on regions that have reported a significantly higher incidence of these pollutants in groundwater. A compilation of various studies is also included in the review paper that showed increased incidences of waterborne illnesses due to fecal and microbial contamination due to poor sanitary practices. Reviews of groundwater contaminants such as fluoride and nitrate are included to provide readers a holistic understanding of groundwater pollution problem around the world. PRACTITIONER POINTS: Groundwater pollution issues during 2018 are reviewed and documented. Occurrence of organic and inorganic pollutants in groundwater is reported. Groundwater pollution vulnerability remains a critical issue.

A Multiscale Assessment of Shallow Groundwater Salinization in Michigan

Managing nonpoint-source (NPS) pollution of groundwater systems is a significant challenge because of the heterogeneous nature of the subsurface, high costs of data collection, and the multitude of scales involved. In this study, we assessed a particularly complex NPS groundwater pollution problem in Michigan, namely, the salinization of shallow aquifer systems due to natural upwelling of deep brines. We applied a system-based approach to characterize, across multiple scales, the integrated groundwater quantity-quality dynamics associated with the brine upwelling process, assimilating a variety of modeling tools and data-including statewide water well datasets scarcely used for larger scientific analysis. Specifically, we combined (1) data-driven modeling of massive amounts of groundwater/geologic information across multiple spatial scales with (2) detailed analysis of groundwater salinity dynamics and process-based flow modeling at local scales. Statewide "hotspots" were delineated and county-level severity rankings were developed based on dissolved chloride (Cl- ) concentration percentiles. Within local hotspots, the relative impact of upwelling was determined to be controlled by: (1) streams-which act as "natural pumps" that bring deeper (more mineralized) groundwater to the surface; (2) the occurrence of nearly impervious geologic material at the surface-which restricts fresh water dilution of deeper, saline groundwater; and (3) the space-time evolution of water well withdrawals-which induces slow migration of saline groundwater from its natural course. This multiscale, data-intensive approach significantly improved our understanding of the brine upwelling processes in Michigan, and has applicability elsewhere given the growing availability of statewide water well databases.

Influence of hydro-geochemical processes on groundwater quality through geostatistical techniques in Kadava River basin, Western India

Hydrogeochemistry and groundwater quality of the Kadava River Basin have been performed by analyzing 40 groundwater samples for pre- and post-monsoon seasons of 2011 through different geostatistical techniques. Analyses showed that the concentrations of Mg2+ exceeded Ca2+ in both the seasons suggesting silicate weathering as a source of ions. Average Ca + Mg values contribute 73.53% of total cations and signify the major supply of mafic minerals. Elevated TDS and TH limit drinking potential and other beneficial uses indicate permanently hard water. The average concentrations of the anions were found within Indian PL except NO3, attributed to use of fertilizers. The spatial distribution maps show the EC, Mg, Na, Cl, and SO4 to be generally higher for both the seasons in flood plain deposits than denuded landforms and middle-level/high-level plateaus containing fractured basalt aquifers. It is confirmed that silicate weathering is the dominant process followed by carbonate weathering. Inputs of TDS, Cl, SO4, Mg, Na, and NO3 are influenced by rainfall and human activities. Groundwater sample numbers 20, 37, and 38 have been severely impacted from agricultural runoff as these samples are located along the surface water flow path. The high loading of TDS and TH is controlled by the Mg, Na, Cl, and SO4 ions. Elevated concentration of Na over Ca represents the ion exchange between Ca and Na. High contents of Mg, Na, Cl, and SO4 corroborate that the groundwater is influenced by anthropogenic sources. This study is an insight for water managers to address groundwater pollution problems.

GIS-based DRASTIC model for groundwater vulnerability and pollution risk assessment in the Peshawar District, Pakistan

Groundwater is the most economic natural source of drinking in urban and rural areas which are degraded due to high population growth and increased industrial development. We applied a GIS-based DRASTIC model in a populated urban area of Pakistan (Peshawar) to assess groundwater vulnerability to pollution. Six input parameters—depth to phreatic/groundwater level, groundwater recharge, aquifer material, soil type, slope, and hydraulic conductivity—were used in the model to generate the groundwater vulnerable zones. Each parameter was divided into different ranges or media types, and ratings R = 1 – 10 were assigned to each factor where 1 represented the very low impact on pollution potential and 10 represented very high impact. Weight multipliers W = 1 – 5 were also used to balance and enhance the importance of each factor. The DRASTIC model scores obtained varied from 47 to 147, which were divided into three different zones: low, moderate, and high vulnerability to pollution. The final results indicate that about 31.22, 39.50, and 29.27% of the total area are under low, moderate, and high vulnerable zones, respectively. Our method presents a very simple and robust way to assess groundwater vulnerability to pollution and helps the decision-makers to select appropriate landfill sites for waste disposals, and manage groundwater pollution problems efficiently.

Fourth-order compact finite difference method for solving two-dimensional convection\u2013diffusion equation

A fourth-order compact finite difference scheme of the two-dimensional convection–diffusion equation is proposed to solve groundwater pollution problems. A suitable scheme is constructed to simulate the law of movement of pollutants in the medium, which is spatially fourth-order accurate and temporally second-order accurate. The matrix form and solving methods for the linear system of equations are discussed. The theoretical analysis of unconditionally stable character of the scheme is verified by the Fourier amplification factor method. Numerical experiments are given to demonstrate the efficiency and accuracy of the scheme proposed, and these show excellent agreement with the exact solution.

Numerical Simulation for Impact of Groundwater Environment in a Chemical Industry Park in the Southwest of Shandong Province Based on GMS

The establishment of chemical industry park can bring great pressure on local groundwater environment, and even cause serious groundwater pollution problems. This study armed at a chemical industry park in southeast of Shandong province and developed a three-dimensional groundwater solute transport model through GMS software, selected dichloromethane as the typical contaminant, simulated and predicated the transport characteristic of groundwater contaminant in different conditions. The results showed that after 20 years, the dichloromethane can separately transport 820m and 1,000m under different hypothetical conditions, the greatest affected area can separately reach 32×104 m2 and 21×104 m2; it indicated that the studied area would be polluted under these simulated conditions, so measures must be done to improve the ability of seepage-proofing of this chemical industry park and to enhance the management and the monitoring of groundwater in this studied area.

The applicability assessment of technical solutions for a feasibility study on the purification of groundwater in the Ilek river valley from boron for the modern hydro geochemical situation

This scientific article is devoted to the problem of pollution of the Aktobe basin with boron by thewaters of the Ilek River, which drains contaminated groundwater. In connection with not full implementation of the decisions taken to reduce the concentration of pollutants, in particular boron, the problemof groundwater pollution is exacerbated. The monitoring datas fix the increased level of pollution. Initiative field studies and the results of the determination of sampling samples showed an excess of thresholdlimit value of boron both in the zone of the old sludge accumulator and in the Aktobe basin. To justifythe need to develop and implement a qualitatively new approach to the solution of the problem ofgroundwater contamination in the Ilek river valley and the Aktobe Basin, boron made estimates for thetopographic and hydrogeological, combined with the technical solutions, the feasibility study, maps. It isshown that now the front of groundwater pollution from the industrial site and the new sludge collectorhas approached the river, and therefore the technical solution of the feasibility study for the second section no longer corresponds to reality. The dynamics of the pollution processes of the Ilek River in the oldsludge accumulator zone is analyzed. Based on the regression model, a forecast is made of the changesin boron content in the right bank of the Ilek River. It is shown that the technical feasibility study on thefirst site requires a revision.As a new approach to solving the problem, it is proposed to develop a system from a constantlyoperating model of geo-filtration and a model of turbulent macro diffusion combined with it. Mappingizoconcentrate of boron and other pollutants of groundwater will provide an opportunity to considerthem from the standpoint of alternative environmental technologies, for example, as the basis of boronfertilizers.Key words: ground water, pollution, boron, basin, feasibility study.

Current situation and control measures of groundwater pollution in gas station

In recent years, pollution accidents caused by gas station leakage has occurred worldwide which can be persistent in groundwater. Numerous studies have demonstrated that the contaminated groundwater is threatening the ecological environment and human health. In this article, current status and sources of groundwater pollution by gas station are analyzed, and experience of how to prevent groundwater pollution from gas stations are summarized. It is demonstrated that installation of secondary containment measures for the oil storage of the oil tank system, such as installation of double-layer oil tanks or construction of impermeable ponds, is a preferable method to prevent gas stations from groundwater pollution. Regarding to the problems of groundwater pollution caused by gas station, it is proposed that it is urgent to investigate the leakage status of gas station. Relevant precise implementation regulations shall be issued and carried out, and supervision management of gas stations would need to be strengthened. Then single-layer steel oil tanks shall be replaced by double-layer tanks, and the impermeable ponds should be constructed according to the risk ranking. From the control methodology, the groundwater environment monitoring systems, supervision level, laws and regulations as well as pollution remediation should also be carried out and strengthened.