Simulation and Prediction of the Groundwater Pollution Caused by the Leakage from a Sewage Plant in an Aluminum Factory Under the Action of Ocean Tide Support

In order to predict the impact of wastewater from an aluminum plant treatment station on the groundwater environment under abnormal conditions (i.e., sewage leakage accident). Through the investigation of hydrogeological conditions, and then the permeability coefficient of the aquifer was measured through borehole injection tests. Finally, the groundwater pollution transport halo was obtained by numerical simulation based GMS software. The simulation results showed that the groundwater aquifer will be seriously polluted by COD and fluoride (F-) after the sudden sewage seepage accident. What’s more, the simulation results showed that the pollution concentration is getting higher and higher with time, which is analyzed to be caused by the small permeability of the water-bearing medium in the aquifer and the groundwater flow field was supported by seawater tide.

An application research for near-surface repository of strontium-90 sorption kinetic model on mudrocks

In this study,90Sr was used as the test radionuclide to characterize the sorption kinetics and effects of initial 90Sr activity and remaining 90Sr in solid concentration were simulated for a near-surface repository. The study focused on the sorption characteristics of radionuclides in unsaturated groundwater environment (or vadose zone) is the important information for investigating the near-surface disposal of intermediate and low-level radioactive waste (ILLW). Moreover, the 90Sr sorption experiments reached equilibrium within 56 h, which fit to the first order sorption kinetic model, and the remaining 90Sr in mudrock samples showed obvious sorption equilibrium hysteresis, which fit to the second order sorption kinetic model. Before reaching the maximum sorption capacity, the sorption rate constant increases with 90Sr increasing; the distribution coefficient (Kd) of 56 h decreases with the remaining 90Sr decreasing. In addition, it showed that the slow sorption process dominated before the sorption reaches equilibrium. In fact, a reliable safety assessment methodology for on-going near-surface repository required a lot of the radionuclides parameters with local environment including the radionuclides sorption/desorption rate constant and maximum sorption capacity.

Characterization and Cause Analysis of Shallow Groundwater Hydrochemistry in the Plains of Henan Province, China

With the development of the human population and society, groundwater environmental problems have become an important factor limiting global socioeconomic development, and the study of groundwater hydrochemical characteristics and pollution is a current hot issue. In this study, data regarding shallow groundwater quality in 76 instances were used to evaluate the quality of shallow groundwater in the plains of Henan Province, China, by using a combination of subjective and objective assignments, mathematical statistics, Piper trilinear diagram, Gibbs diagram, ion ratio analysis, and other methods to study the hydrochemical characteristics of groundwater and its formation mechanism. The results showed that the groundwater quality in most areas of the plains of Henan Plain is in good condition, and the proportion of samples with excellent grades and good grades is as high as 43.42% and 35.53%. The range of poor and extremely poor water quality is small, and only five samples are judged as poor and extremely poor grades, mainly distributed in Jiaozuo City, Xinxiang City, Zhoukou City, and Puyang City. The groundwater anionic hydrochemistry is mainly of the HCO3 type, accounting for 61.84% of the samples and locally transformed downstream to HCO3·SO4, HCO3·SO4·Cl, HCO3·Cl·SO4, and Cl·SO4·HCO3. Cations are predominantly of the Ca/Mg and Ca–Mg/Mg–Ca type, and gradually transformed to the Na–Ca/Ca–Na and Na–Mg/Mg–Na type along the runoff direction. Water–rock interactions and anthropogenic factors dominate the hydrochemistry evolution, with major geochemical processes involving the precipitation of calcite and dolomite as well as the weathering dissolution of rock salt and fluorite. Human activity is an important factor affecting the distribution of NO3–N and Fe3+. It is recommended that groundwater be continuously monitored to provide scientific data for sustainable groundwater quality management and that appropriate measures be developed to prevent further degradation of the groundwater environment.

Research Advances in the Analysis of Nitrate Pollution Sources in a Freshwater Environment Using δ15N-NO3− and δ18O-NO3−

Nitrate is usually the main pollution factor in the river water and groundwater environment because it has the characteristics of stable properties, high solubility and easy migration. In order to ensure the safety of water supply and effectively control nitrate pollution, it is very important to accurately identify the pollution sources of nitrate in freshwater environment. At present, as the most accurate source analysis method, isotope technology is widely used to identify the pollution sources of nitrate in water environment. However, the complexity of nitrate pollution sources and nitrogen migration and transformation in the water environment, coupled with the isotopic fractionation, has changed the nitrogen and oxygen isotopic values of nitrate in the initial water body, resulting in certain limitations in the application of this technology. This review systematically summarized the typical δ15N and δ18O-NO3− ranges of NO3− sources, described the progress in the application of isotope technique to identify nitrate pollution sources in water environment, analyzed the application of isotope technique in identifying the migration and transformation of nitrogen in water environment, and introduced the method of quantitative source apportionment. Lastly, we discussed the deficiency of isotope technique in nitrate pollution source identification and described the future development direction of the pollution source apportionment of nitrate in water environment.

Hydrochemical Characteristics of Groundwater at the Epicenter of the 2021 Biru M6.1 Earthquake in Central Tibet

Groundwater is undoubtedly important for water security and eco-environmental protection, especially in areas that experience earthquakes. Analyzing the characteristics and variation of groundwater after an earthquake is significant to obtain a better understanding of the seismic risk and rational management of groundwater resources. This study investigated the hydrogeochemical characteristics of groundwater at the epicenter of the 2021 Biru M6.1 earthquake in central Tibet, southwest China, using 23 water samples. The results showed that: (1) the hydrochemical type, hydrogen and oxygen isotope ratios, and SiO2 concentrations of three hot spring water samples in the study area were significantly different from those of samples taken elsewhere, indicating that the hot spring water originates from deeper geothermal reservoirs and has undergone more distant migration and longer fractionation processes; (2) the geochemical characteristics of groundwater from some sampling sites in the epicentral area were apparently distinct from those of other shallow groundwater or surface water samples, suggesting that the groundwater environment in the epicentral area has been affected by the earthquake. Along with the macroscopic groundwater responses in the epicentral area after the earthquake, we investigated the influencing mechanisms of the earthquake on the regional groundwater environment. We conclude that a shorter distance from the epicenter to the seismogenic fault leads to a greater possibility of the generation of new fractures, which then induce macroscopic responses and chemical characteristic variations for groundwater.

Preliminary Evaluation of the Possible Occurrence of Pesticides in Groundwater Contaminated with Nitrates—A Case Study from Southern Poland

This paper addresses groundwater pollution and the potential presence of pesticides within the catchment areas of two reservoirs that are sources of drinking water. The two reservoirs are Goczałkowice and Kozłowa Góra, both in Southern Poland. Agricultural and rural areas dominate both catchments. Archival data showed local groundwater contamination with nitrates. This indicated the possible presence of pesticides in shallow groundwater. In total, 13 groundwater samples from shallow sandy aquifers were collected. All the samples were tested for the presence of 35 organophosphate pesticides and 28 organochlorine pesticides. Additionally, in order to determine the current groundwater conditions, physicochemical parameters were measured in the field, and water samples were subjected to analysis of their chemical composition (incl. the determination of nitrates). The research outcomes showed that pesticides were not detected above the detection limits in any of the samples. Due to variations in the persistence and degradation rates of pesticides, the occurrence of these substances in the groundwater environment and the possibility of their migration to aquifers should not be completely excluded. Natural processes and factors (e.g., sorption, biodegradation, hydrolysis and redox conditions) may gradually reduce the pesticide concentrations in groundwater. The chemical analyses revealed high concentrations of nitrates in the groundwater. This suggests the possible influence of agriculture and fertilizer application on groundwater quality; however, a proportion of NO3- ions may be connected with improper sewage management within the two catchments. The absence of pesticides in groundwater impacted by agriculture may result from processes occurring in the aquifer and the rapid degradation of these compounds due to photolysis and prevailing weather conditions. In the vicinity of dwellings, nitrates also originate from domestic wastewater. Thus, the occurrence of pesticides in groundwater contaminated with NO3 cannot always be expected.

Evaluation of the Impact of Ecological Water Supplement on Groundwater Restoration Based on Numerical Simulation: A Case Study in the Section of Yongding River, Beijing Plain

Ecological water supplement relies on river channels to introduce surface water, to make a reasonable supplement of groundwater, to repair the regional groundwater environment and urban river ecosystem. Evaluating the degree of groundwater restoration after ecological water supplement (by taking appropriate measures) is a critical problem that needs to be solved. Thus, based on the Yongding River ecological water supplement in 2019 and 2020, we analyzed the groundwater monitoring situates in the ecological water supplement region. We established an unstructured groundwater flow numerical model in the study area through the quadtree grids. The model was calibrated with the measured water level. The simulated results could accurately reflect the real groundwater dynamic characteristics, and it showed that the water level rise was concentrated in the 3–6 km range of the Yongding River after the ecological water supplement. In 2019, the calculated ecological water infiltration amount was 101.28 × 106 m3, the affected area was 265.19 km2, and the average groundwater level rise in the affected area was 2.10 m. In 2020, the calculated ecological water infiltration amount was 102.64 × 106 m3, the affected area was 506.88 km2, and the average groundwater level rise in the affected area was 1.25 m. While the ecological water supplement had a positive impact on groundwater level restoration, the groundwater level around the typical buildings within the study area, including Beijing West Railway Station and Beijing Daxing International Airport, would not be significantly affected.

Geotechnical and Environmental Assessment of Blast Furnace Slag for Engineering Applications

The increasing demand for building materials in the road industry creates interest for a new source of high-quality aggregates. In order to conserve natural resources, more attention is focused on anthropogenic soils and industrial solid wastes. For the successful application of these types of soil, a series of geotechnical and environmental tests have to be conducted. A potential hazard in the reuse of wastes from thermal degradation in the construction industry, particularly in reinforced concrete (RC) construction, is the migration of heavy metals into the groundwater environment. In this article, a geotechnical assessment of blast furnace slag (BFS) properties is presented. We conducted a series of CBR, and oedometric tests to evaluate the feasibility of BFS application in earth construction. The oedometric test results show acceptable compression characteristics which are in the range of natural aggregates. The CBR shows that this material may be used as a pavement subbase. We also noticed the preconsolidation pressure phenomenon in both Proctor and vibro-compacted soil during the oedometric test. The compression index and recompression index value show that the compression characteristics are close to those of dense sand. Based on the results described in the article, blast furnace slag is a candidate for technological application and can become one of the elements of sustainable development by contributing to a reduction in the negative environmental impact of production and use of building materials.

Groundwater development, use, and its quality in Korea: tasks for sustainable use

In this study, the current state of groundwater development and use and groundwater quality has been examined based on official groundwater data collected from the Republic of Korea. The groundwater data indicate a steady increase in the number of groundwater wells and an increase in groundwater pumping. The well diameters also increase with increasing well depth, owing to the development of drilling technology. Although groundwater is predominantly used for agricultural and living purposes, the former has recently outnumbered the latter. According to the groundwater quality monitoring stations covering the entire country, the groundwater levels, dissolved oxygen, and oxidation–reduction potential decrease with a steady increase in the water temperature, pH, and electrical conductivity, indicating an aggravating groundwater environment in this region. The most concerning contaminants found are nitrate, ammonia, arsenic, zinc, toluene, xylene, chloroform, and fluoride. Thus, based on these observations, we propose three essential tasks for sustainable groundwater use: a paradigm shift in groundwater management, conjunctive use and integrated management of groundwater and stream water, and groundwater governance and data quality control.