COMPARATIVE ANALYSIS OF THE CHEMICAL COMPOSITION OF WATERWATER IN THE SLAVSKY DISTRICT OF THE KALININGRAD REGION BY HYDROLOGICAL SEASONS

The aim of the work is to research the chemical composition of surface watercourses in the Slavsky district of the Kaliningrad region in the winter hydrological season, and to compare the results with the data previously obtained by the authors for the autumn hydrological season and partly for the summer hydrological season. Watercourses and monitoring points for research have been identified: r. Zlaya, r. Shluzovaya, r. Nemoninka and r. Osa. In the winter season, water samples were taken, hydrometric characteristics were measured, and primary hydrochemical indicators were determined. On the basis of the obtained hydrochemical data, integral indicators were calculated to assess the quality of water, using combined lists of maximum permissible concentrations of pollutants. When monitoring hydrochemical indicators, it was revealed that the studied watercourses are, to one degree or another, subject to pollution. The water quality class in them varies from "moderately polluted" to "extremely dirty". When comparing the seasons, a tendency was revealed to improve the quality of water, which is associated with the water content of rivers, as well as with the cycles of natural and anthropogenic activity. The work has theoretical and practical significance. The data can participate in the planning of rational use of natural resources and the selection of measures to improve the geoecological state of the river network of the Slavsky region. The research can serve as a supplement to the formation of the general geoecological picture of the Kaliningrad region.

Appraisal of the Quality Parameters of the Groundwater used for Domestic and Irrigation Purposes in the Hard Rock Aquifer System of the Vasishta sub- basin of the Vellar River, Tamil Nadu

This article presents an appraisal of the quality of groundwater in the hard Received in revised form: 15.07.2021 rock aquifer system of the Vasishta sub basin, of the Vellar River Basin. Seventy nine representative groundwater samples were collected from dug and bore wells which are intensively used for domestic and irrigational purposes. The physical parameters viz. PH, EC and TDS were estimated in the field using a portable multiparameter meter. The groundwater samples were transported to the laboratory for measuring major ionic concentrations viz, Ca, Mg, Na, K, CO3, HCO3, Cl, SO4, F and NO3. The hydrochemical data were graphically projected and spatial temporal thematic maps generated with reference to the World Health Organization (WHO) and Bureau of Indian (BIS) Standards. The peoples living in the sub basin engage in agricultural activities where the groundwater availability is sufficient. The groundwater is a major source for meeting their basic needs, such as for domestic, irrigational and industrial purposes. Good correlation is exhibited between EC and TDS Cl, SO4.Cl exhibits good correlation with Mg and Ca (0.817), (0.751) indicating leaching of secondary salts. TDS and EC showed strong correlation with Cl, SO4. Clustering groundwater samples based on their similarity is known as Q-mode type clustering method. Spatial and temporal maps of the water quality index reveal that the majority of the groundwater samples fall under the categories excellent to good.

Simulation of Density and Flow Dynamics in a Lagoon Aquifer Environment and Implications for Nutrient Delivery From Land to Sea

The near coastal zone, hosting the saltwater-freshwater interface, is an important zone that nutrients from terrestrial freshwaters have to pass to reach marine environments. This zone functions as a highly reactive biogeochemical reactor, for which nutrient cycling and budget is controlled by the water circulation within and across that interface. This study addresses the seasonal variation in water circulation, salinity pattern and the temporal seawater-freshwater exchange dynamics at the saltwater-wedge. This is achieved by linking geophysical exploration and numerical modeling to hydrochemical and hydraulic head observations from a lagoon site at the west coast of Denmark. The hydrochemical data from earlier studies suggests that increased inland recharge during winter drives a saltwater-wedge regression (seaward movement) whereas low recharge during summer causes a wedge transgression. Transient variable density model simulations reproduce only the hydraulic head dynamics in response to recharge dynamics, while the salinity distribution across the saltwater wedge cannot be reproduced with accuracy. A dynamic wedge is only simulated in the shallow part of the aquifer (<5 m), while the deeper parts are rather unaffected by fluctuations in freshwater inputs. Fluctuating salinity concentrations in the lagoon cause the development of a temporary intertidal salinity cell. This leads to a reversed density pattern in the underlying aquifer and the development of a freshwater containing discharge tube, which is confined by an overlying and underlying zone of saltwater. This process can explain observed trends in the in-situ data, despite an offset in absolute concentrations. Geophysical data indicates the presence of a deeper low hydraulic conductive unit, which coincides with the stagnant parts of the simulated saltwater-wedge. Thus, exchange fluxes refreshing the deeper low permeable areas are reduced. Consequently, this study suggests a very significant seasonal water circulation within the coastal aquifer near the seawater-freshwater interface, which is governed by the hydrogeological setting and the incoming freshwater fluxes, where nutrient delivery is limited to a small corridor of the shallow part of the aquifer.

Artificial Intelligence In Source Discrimination of Mine Water: A Deep Learning Algorithm For Water Source Discrimination

With increasing coal mining depth, the source of mine water inrush becomes increasingly complex. The problem of distinguishing the source of mine water in mines and tunnels has been addressed by studying the hydrochemical components of the Pingdingshan Coalfield and applying the artificial intelligence (AI) method to discriminate the source of the mine water. 496 data of mine water have been collected. Six ions of mine water are used as the input data set: Na++K+, Ca2+, Mg2+, Cl-, SO2- 4, and HCO- 3. The type of mine water in the Pingdingshan coalfield is classified into surface water, Quaternary pore water, Carboniderous limestone karst water, Permian sandstone water, and Cambrian limestone karst water. Each type of water is encoded with the number 0 to 4. The one-hot code method is used to encode the numbers, which is the output set. On the basis of hydrochemical data processing, a deep learning model was designed to train the hydrochemical data. Ten new samples of mine water were tested to determine the precision of the model. Nine samples of mine water were predicted correctly. The deep learning model presented here provides significant guidance for the discrimination of mine water.

Seawater Intrusion Assessment based on Hydrochemical Data in Gapura Sub-district of Sumenep Regency, East Java, Indonesia

Gapura is a sub-district with a large salt pond in Sumenep Regency, Madura Island, Indonesia. In this area, many residents’ houses have drilled wells to meet their water needs. One factor is that Municipal Waterwork (PDAM) does not reach the area due to limited water sources and difficult accessibility. Residents in the area claimed to have found some groundwater that tasted brackish. This study aims to apply hydrochemical analysis to identify the possibility of seawater intrusion in the area. The assessment of seawater intrusion uses the total dissolved solids (TDS) value and major ion of groundwater samples. In the analysis of thirty samples, two samples have different values from the samples of freshwater. However, the value of these two samples is relatively low to be classified as seawater intrusion. It is described on the TDS values that belong to the class of brackish water, from Simpson ratio values classified as slightly contaminated, and from the piper diagram plot that is still in the mixing zone in the middle of the diagram. The presence of brackish water in these samples can be caused by a location close to salt pond activities.

Quali-quantitative considerations on low-flow well purging and sampling

This article deals with both the main advantages and issues related to groundwater purging and sampling that are usually carried out through the so-called low-flow methodology or with the method based on the purging of 3-5 well volumes, which is still widely used in environmental monitoring. A review of the recent literature concerning the technical characteristics, innovations and modelling related to low-flow sampling is presented. The aim is to provide to the reader a broad overview on this specific field application and offer a new vision, which considers two aspects: 1. The qualitative aspect, relating to the representativeness of the sample taken through a correct purging of the monitoring well and the consequent correct interpretation of hydrochemical data; 2. The quantitative aspect, related to the possibility of using water level data during purging and low-flow sampling operations to estimate the soil horizontal hydraulic conductivity, without further investigations. Low-flow sampling methodology can be very useful especially for alluvial aquifers, providing representative samples of groundwater and hydrodynamic characteristics of the aquifer, with reduced costs and times. These two aspects are both important in the context of an environmental monitoring plan for a potentially contaminated site.

Temporal and Spatial Groundwater Contamination Assessment Using Geophysical and Hydrochemical Methods: The Industrial Chemical Complex of Estarreja (Portugal) Case Study

With more than a half-century in operation, the industrial chemical complex of Estarreja (ICCE) in northern Portugal has left serious environmental liabilities in the region. Although protective measures were implemented, soils, surface, and groundwater contamination caused by persistent pollutants are still prevalent. This study presents data from several geophysical and hydrochemical campaigns carried out to monitor groundwater contamination in the Estarreja region over a period of 30 years. Both geophysical and hydrochemical data showed a good agreement and revealed an important anomaly caused by groundwater contamination (high levels of Na, Cl, SO4, and Fe, among others) in 2006–2007, likely caused by the remobilization of waste pollutants (roasted pyrites, soils, and sludge) during their deposition in a sealed landfill (operating between 2003 and 2005). More recently, in 2016, this impact persists, but was more attenuated and showed a general migration pattern from E to SW according to one of the main groundwater flow paths. Groundwater flow in this region has a local radial behaviour. Drainage effluent systems, such as ditches and buried pipes formerly used by ICCE, are also likely to contribute to some contamination “hotspots”. Finally, the results obtained by the combined use of these two approaches allowed for the delineation of the contamination plume for future monitoring.

Technogenic transformation of the underground hydrosphere of Kazan. Lower Kazanian aquifer complex

Relevance. By the beginning of the XXI century, the growth of cities, population concentration and the revival of industrial production led to an intense technogenic pressure on the underground hydrosphere. In ecological and hydrogeological studies, it becomes necessary to conduct monitoring observations of groundwater based on GIS technologies. Purpose of the work: study of the hydrogeochemical characteristics of underground waters of the aquiferous lower Kazanian carbonate-terrigenous complex to provide Kazan with high-quality drinking water from protected underground sources. Research methodology. Hydrochemical data from geological reports and archival materials for the period from 1960 years to 2019 years were used. Methods of mathematical statistics (basic, cluster and factor analyzes) made it possible to differentiate into natural and man-made components. Geographic information modeling using the “ArcGisMap” package showed the spatial variability of the main components in the waters of the Neogene complex at the turn of the 20th and 21st centuries. Conclusion. The hydrochemical parameters of the aquiferous lower Kazanian complex are assessed as favorable, since practically all the main components do not exceed the MPC values for drinking water.

Comparison Of Isotope And Hydrochemical Characteristics Of Springs In Sembalun – Rinjani Area, East Lombok, West Nusa Tenggara, Indonesia Before And After The Earthquake Events In 2018

The current 2019 isotope and hydrochemical study of hot and cold springs in Sembalun - Rinjani area is a re-assessment of previous similar study in 2012. The aim of this study is to assess the isotope and hydrochemical characteristics of springs due to the earthquake events in 2018. After the earthquake events in 2018, the stable isotopes δ18O and δ2H composition of Sebau hot spring and most of cold springs is shifted into more depleted values which may indicate water-rock interaction or interaction with cold waters which has more depleted δ18O and δ2H values. Also, Sebau hot spring is still plotted at mixing line of meteoric and andesitic water, but still dominant meteoric water. The hydrochemical data of all cold springs and Orok river show the enrichment of Na, probably from silicates weathering or the cation exhchange. While hydrochemical composition of Sebau hot spring is significantly decreased, except SO4, probably due to dilution with cold waters before the thermal water reach the surface. The Piper diagram showed that cold springs and Orok river are Ca-Mg-HCO3 type before and after the earthquake events. While Sebau hot spring is shifted from Ca-Cl type into mixed Ca-Mg-Cl type after the earthquake events. The temperature of Sebau hot spring slightly decreased from 35.5 °C to 34.8 °C after the earthquake events, while Na/K geothermometer calculation also indicate decreasing of sub-surface temperature, i.e. from 146–165 °C to 130–150 °C.