Groundwater Contamination Research Papers - Academia.edu (original) (raw)

2025, Global Scientific Journals

La pollution des eaux souterraines dans les zones où des activités de maraîchage sont pratiquées de manière permanente, due aux résidus de pesticides, constitue une préoccupation croissante. Cela soulève des inquiétudes quant à la qualité des eaux de puits utilisées pour la production agricole. Entre juin et septembre 2024, le Laboratoire Central Vétérinaire (LCV) a mené une étude à Sotuba (Bamako), comprenant des enquêtes et des analyses d'échantillons d'eau. Les enquêtes auprès des maraîchers avaient pour objectif d'identifier les pratiques agricoles et les pesticides utilisés. Trente puits maraîchers, d'une profondeur variant de 6 à 10 mètres, ont été géoréférencés et échantillonnés. Les échantillons ont été prélevés et analysés à l'aide d'un chromatographe en phase gazeuse couplé à un spectromètre de masse (GC-MS) de marque Agilent 7890.Les résultats des analyses ont révélé un taux de contamination général d'environ 90 %. Cinq molécules de pesticides ont été détectées et quantifiées, dont trois homologués (chlorpyriphos, deltaméthrine et lambda-cyhalothrine) et deux non homologués (glufosinate et dicofort). Le chlorpyriphos est la molécule la plus fréquemment détectée (9 échantillons, 0,006-0,013 µg/L), tandis que la deltaméthrine est la moins répandue (4 échantillons, 0,004-0,041 µg/L). Trois puits ne présentaient aucune trace de résidus. La présence de pesticides dans les eaux de puits de Sotuba indique un risque sanitaire potentiel. Un encadrement plus strict de l'utilisation des pesticides est nécessaire pour protéger les ressources en eau et la santé publique des consommateurs des produits maraîchers.

2025, Journal of Contaminant Hydrology

The potential contamination of groundwater by herbicides is often controlled by processes in the vadose zone, through which herbicides travel before entering groundwater. In the vadose zone, both physical and chemical processes affect the fate and transport of herbicides, therefore it is important to represent these processes by mathematical models to predict contaminant movement. To simulate the movement of simazine, a herbicide commonly used in Chilean vineyards, batch and miscible displacement column experiments were performed on a disturbed sandy soil to quantify the primary parameters and processes of simazine transport. Chloride (Cl -) was used as a non-reactive tracer, and simazine as the reactive tracer. The Hydrus-1D model was used to estimate the parameters by inversion from the breakthrough curves of the columns and to evaluate the potential groundwater contamination in a sandy soil from the Casablanca Valley, Chile. The two-site, chemical non-equilibrium model was observed to best represent the experimental results of the miscible displacement experiments in laboratory soil columns. Predictions of transport under hypothetical field conditions using the same soil from the column experiments were made for 40 years by applying herbicide during the first 20 years, and then halting the application and considering different rates of groundwater recharge. For recharge rates smaller than 84 mm year -1 , the predicted concentration of simazine at a depth of 1 m is below the U.S. EPA's maximum contaminant levels (4 μg L -1 ). After eight years of application at a groundwater recharge rate of 180 mm year -1 (approximately 50% of the annual rainfall), simazine was found to reach the groundwater (located at 1 m depth) at a higher concentration (more than 40 μg L -1 ) than the existing guidelines in the USA and Europe.

2025, Groundwater

Sequential time‐step images acquired using nuclear magnetic resonance (NMR) show the displacement of deuterated water (D2O) by fresh water within two limestone samples characterized by a porous and permeable limestone matrix of peloids and ooids. These samples were selected because they have a macropore system representative of some parts of the eogenetic karst limestone of the Biscayne Aquifer in southeastern Florida. The macroporosity, created by the trace fossil Ophiomorpha, is principally well connected and of centimeter scale. These macropores occur in broadly continuous stratiform zones that create preferential flow layers within the hydrogeologic units of the Biscayne. This arrangement of porosity is important because in coastal areas, it could produce a preferential pathway for salt water intrusion. Two experiments were conducted in which samples saturated with D2O were placed in acrylic chambers filled with fresh water and examined with NMR. Results reveal a substantial flu...

2025

In this study, we use an innovative, non-invasive technology, nuclear magnetic resonance imaging (NMRI), to visualize the direction and magnitude of groundwater flow in field samples of late Pleistocene limestone of the Biscayne aquifer.... more

2025, Science of The Total Environment

Total bacterial cells most related variable to tryptophan-like fluorescence (TLF) • TLF and humic-like fluorescence strongly correlate with dissolved organic carbon. • Thermotolerant coliforms are not strongly related to other variables.... more

2025, Water Supply

This research explores the possibility of creating an underground water reservoir by injecting treated wastewater and evaluates the recovery efficiency and water quality under different injection/recovery scenarios. An injection/recovery well was established in the Dammam Formation aquifer in Kuwait. Six observation wells were also drilled nearby to monitor the water levels and quality. A three-dimensional (3D) numerical hydraulic and transport model was set up using the coupled version of MODFLOW and MT3DMS. Four scenarios of cyclic and continuous injection with different injection and pumping rates stretching over 5,400 days were investigated. Two dispersivity values, low (10 m) and high (200 m), were used in each scenario in order to establish the minimum and maximum recovery limits of useful water that can be expected from the site. The combination of injection rate of 650 m3/d and subsequent recovery at 1,000 m3/d proved to be the optimum option for the storage of water, result...

2025

Introduction: Groundwater contamination by potentially toxic elements (PTEs) poses serious health risks in Bangladesh, yet limited studies have addressed their seasonal and spatial variability. In the Barind Tract, Rajshahi, groundwater is a critical resource for drinking and irrigation,emphasizing the need for a comprehensive evaluation of contamination patterns and health implications.
Methods: A total of 244 groundwater samples (122 per season) were analyzed for As, Al, Cu, Mn, Cr, and B using Atomic Absorption Spectrophotometry and VIS Spectrophotometry. Contamination was assessed using Metal Evaluation Index (MEI), Nemerow Pollution Index (NPI), Contamination Degree (CD), and Poseidon Index (PoS).
Statistical analyses included ANOVA, effect size (η ², f²), PCA, and HCA. Monte Carlo simulation (10,000 iterations, 95% CI) estimated probabilistic health risks for adults and children.
Results: Boron (1.034 mg L⁻¹) and manganese (0.824 mg L⁻¹) dominated during the wet season, while manganese (0.735 mg L⁻¹) and aluminum (0.605 mg L⁻¹) were highest in the dry season. MEI, NPI, and CD indices indicated significant contamination in Sirajganj, Chapai Nawabganj, and Natore, with Chapai Nawabganj (PoS 9.01) and Natore (PoS 8.223) showing extensive groundwater degradation. Statistical analyses confirmed significant seasonal variations, with aluminum, copper, chromium, and boron showing the most fluctuation due to hydrological
and geochemical changes. Health risk assessments identified 64 samples unsafe for children and 32 for adults, with Monte Carlo simulations indicating hazard indices reaching up to 4.68 for children in certain hotspots.
Conclusions: Pronounced seasonal variations in groundwater contamination underscore the necessity of targeted, season-specific monitoring and mitigation measures. Tailored interventions are essential to safeguard public health, especially for children who face higher exposure risks. The findings offer critical insights for policy- makers and stakeholders, promoting sustainable groundwater management in the Barind Tract.

2025, Plant, Soil and Environment

This study attempted to evaluate the efficiency of zeolite and pyrophyllite ore materials in reducing the mobility of heavy metals in soil near the lignite mining dumps, and consequently in their availability for plants. Extraction of pseudo-total and available forms of heavy metals from soil samples was performed by using aqua regia and ethylenediaminetetraacetic acid, respectively. Concentrations of heavy metals in soil and plant samples were determined by atomic absorption spectrophotometry. The results of this study illustrate that application of zeolite and pyrophyllite could be a suitable technique to reduce heavy metals availability in soils. Zeolite treatments have been shown to be significantly effective in reducing cadmium (Cd) mobility, as well as pyrophyllite treatments in reducing lead (Pb) mobility in the studied soil, regardless of applied rates. The accumulation of heavy metals in leaves of maize grown on soil plots treated by zeolite and pyrophyllite, was found to be lower compared to the untreated plots. This finding was to be expected, considering the effects of these treatments on heavy metals mobility in the studied soil.

2025, Analytical Chemistry

-phase extraction (SPE) and liquid chromatography in combination with ion trap mass spectrometry (LC/MS/ MS) conditions were optimized for the simultaneous analysis of 13 antibiotics belonging to multiple classes and caffeine in 3 different water matrixes. The single-cartridge extraction step was developed using a reversed-phase cartridge, resulting in recoveries for the 14 compounds ranging from 71 to 119% with relative standard deviations of 16% or lower. The analytes were separated in one chromatographic run, and the SPE-LC/MS/MS detection limits ranged from 0.03 to 0.19 µg/L. The SPE procedure was validated in groundwater, surface water, and wastewater. The analysis of samples from each of the three water matrixes revealed clindamycin (1.1 µg/L) in surface water and multiple antibiotics in wastewater (0.10-1.3 µg/L). The use of identification points to unambiguously assign the identity of antibiotics in various water matrixes was applied to an ion trap data-dependent scanning method, which simultaneously collects full scan and full scan MS/MS data for the unequivocal identification of target analytes.

2025, Environmental Earth Sciences

The occurrence of dental/skeletal fluorosis among the people in the study area provided the motivation to assess the distribution, severity and impact of fluoride contamination in groundwater of Bankura district at Simlapal block, West Bengal, India. To meet the desired objective, groundwater samples were collected from different locations of Laxmisagar, Machatora and Kusumkanali regions of Simlapal block at different depths of tube wells in both pre-and post-monsoon seasons. Geochemical results reveal that the groundwaters are mostly moderate-to hard-water type. Of total groundwater samples, 37% are situated mainly in relatively higher elevated region containing fluoride above 1.5 mg/L, indicating that host aquifers are severely affected by fluoride contamination. Machatora region is highly affected by fluoride contamination with maximum elevated concentration of 12.2 mg/L. Several symptoms of fluorosis among the different age-groups of people in Laxmisagar and Machatora areas are indicating consumption of fluoridated water for prolonged period. The groundwater samples were mainly Na-Ca-HCO 3 type and rock dominance indicating the dissolution of minerals taking place. Ion exchange between OH -ion and F -ion present in fluoride-bearing mineral is the most dominant mechanism of fluoride leaching. High concentration of Na + and HCO 3 -increases the alkalinity of the water, providing a favorable condition for fluoride to leach into groundwater from its host rocks and minerals.

2025

The study investigated the importance and image behavior of integrated geophysical methods in mapping contaminant spread beneath the surface of a pollution site in Ogoniland, Southern Nigeria. Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar (GPR) techniques constrained by Vertical Electrical Sounding (VES) data were employed to investigate the electrical properties of hydrocarboncontaminated soils that resulted from recent oil spills/leakage into the environment. Five (5) ERT and GPR lines and twenty-nine (29) VES data were acquired at the spill site. Basically, the electrical signatures from the resistivity measurements were able to image the subsurface layers and the associated contamination zone. GPR equally imaged the subsurface stratigraphy to a depth of 10.0 m beneath the surface. The interpretation of the five (5) ERT data showed consistency in the resistivity structure indicative of contaminant plumes with anomalously high electrical resistivity in the range of 1000-10,000 Ωm, a possible indication of hydrocarbon contamination. On the GPR radargram, regions of high electrical resistivities were in agreement with reduced GPR reflection behavior (shadow zones) and were limited to the near surface of the surveyed areas. Vertical electrical sounding delineated layers with high resistivity predominantly within the second and fourth geoelectric layers within pollution depths of 2.4 m and 11.9 m, respectively. As a result, the underground aquifer, relatively between 7.5 and 10.5 m, has been infiltrated by hydrocarbons. It can be seen from the study that geoelectric measurements on the surface can describe the distribution of hydrocarbon resistive zones as well as their conductive behavior that may be linked with the biodegradation of oil spills in the subsurface. Thus, the employment of these integrated methods for contaminant monitoring, hydrogeologic studies and remediation planning reduced the uncertainties, and they are of extensive relevance in mapping the geological behavior of polluted soils in contamination sites.

2025

The Jessore district in Bangladesh is facing a critical issue due to saline intrusion in its southwest coastal area. This research paper presents a groundwater vulnerability assessment in the salinity-affected southwest coastal region of Bangladesh, focusing on the application of the DRASTIC index method in the Jessore district. The analysis reveals that 1654.91 km 2 or around 64.38 % of the Jessore district is moderately vulnerable, and 31.62% is at high risk. The results of the groundwater vulnerability assessment revealed that the study area is highly vulnerable to groundwater salinization due to the presence of shallow aquifers, low recharge, and high permeability. The findings of the study provide valuable information to the groundwater management authorities to identify and prioritize the areas of high vulnerability.

2025, Ecological Engineering & Environmental Technology

Groundwater salinity is a serious problem for water quality in the irrigated parts of arid and semi-arid regions, especially in the aquifers of Berrechid, Morocco. This study used a variety of techniques, including the Water Quality Index (WQI) and World Health Organization (WHO) recommended limits, Principal Component Analysis (PCA), and Geographic Information System (GIS) to evaluate the quality of the groundwater for irrigation and domestic use in the Berrechid region in central Morocco. The goal of this study was to evaluate the quality of groundwater for irrigation and human consumption. The collection and analysis of twenty-two samples for ions was carried out, including, EC, Cl-, NO 3 -, NH 4 + , NO 2 -, Ca 2+ , Mg 2+ , pH, SO 4 2-, Na + , K + , CO 3 -, HCO 3 -, and Mn 2+ . The Water Quality Index (WQI) was used to classify the water quality vis: excellent, good, average, poor and very poor. The research area's water quality index (WQI) ranges from 43.89 to 439.34, with around 40.90% of samples having excellent water quality, 45.45% having poor water quality, 4.54% showing extremely bad water quality, and 9.09% having unsuitable quality for human consumption. The principal component analysis reveals that the average concentration of cations in groundwater was Na + > Mg 2+ > Ca 2+ > K + > Mn 2+ > NH 4 + , whereas the concentration of anions was Cl -> HCO 3 -> SO 4 2-> NO 3 -> NO 2 -> CO 3 2-. The correlation matrix was created and analyzed to determine its significance in groundwater quality assessment. The primary sources of pollution are household waste, exposed septic tanks, landfill leachate, and excessive fertilizer usage in agriculture and industrial operations. The current analysis demonstrates that the deteriorating groundwater quality in the region needs pre-consumption treatment and contamination risk prevention.

2025, Journal of Water Resource and Protection

A quantitative analytical data from the alluvial aquifers of Ganga-Sot Sub-Basin (GSSB) is subjected to multivariate statistical analysis in order to ascertain the groundwater quality characterization depending on the top soil/physiographic divisions. The matrix consists of ten variables of 34 groundwater samples collected from evenly spaced locations. The Hierarchical cluster analysis resulted in six clusters. Each cluster group is individually subjected to Principal component analysis (PCA). PCA of group A explains cumulative variance of 83%, and 95% of group of B, 82% of group C, 91% of group of D. Dissimilarity among the clusters is due to anthropogenic influence on the groundwater regime. The PCA is done for the groundwater quality data of the whole area and on the data of sub-divided area. The PCA of the whole area resulted in five components with cumulative variance of 69.19%. The area is sub divided on the basis of soil type/physiography and data falling in each sub-division is subjected to PCA. The PCA of clay loam soil/Ganga Mahwa low land resulted in five PCs explaining cumulative variance of 91%. The PCA of sandy soil/central upland data extracted four PCs with 80% of cumulative variance. The PCA of loam type of soil/Sot plain extracted three PCs explaining cumulative variance of 91.751%. The three physiographic units of the alluvium setting reflect distinct groundwater quality as manifested by the PCA. From this study it can be ascertained that PCA can be used for the characterization of groundwater quality information.

2025, Water, Air, & Soil Pollution: Focus

The paper deals with the problem of minimizing the cost of pumping groundwater from a number of wells. A genetic algorithm approach is presented with the following characteristics: (a) Well locations are treated as optimization parameters and the well configurations are represented by a single integer combinatorial variable. (b) The objective function chosen is flat and appropriate scaling is performed. (c) No penalty functions are involved in constraint handling. Instead, the feasible region is transformed into an n-dimensional cube and at the same time a suitable boundary extension is introduced. Finally, the optimal well configuration is rapidly approached.

2025, Water

Groundwater contamination with sub-lethal dissolved contaminants poses significant health risks globally, especially in rural India, where access to safe drinking water remains a critical challenge. This study explores the hydrogeochemical characterization and associated health risks of groundwater from shallow aquifers in the Marginal Ganga Alluvial Plain (MGAP) of northern India. The groundwater chemistry is dominated by Ca-Mg-CO 3 and Ca-Mg-Cl types, where there is dominance of silicate weathering and the ion-exchange processes are responsible for this solute composition in the groundwater. All the ionic species are within the permissible limits of the World Health Organization, except fluoride (F -) and nitrate (NO 3 -). Geochemical analysis using bivariate relationships and saturation plots attributes the occurrence of F -to geogenic sources, primarily the chemical weathering of granite-granodiorite, while NO 3 -contaminants are linked to anthropogenic inputs, such as nitrogen-rich fertilizers, in the absence of a large-scale urban environment. Multivariate statistical analyses, including hierarchical cluster analysis and factor analysis, confirm the predominance of geogenic controls, with NO 3 --enriched samples derived from anthropogenic factors. The spatial distribution and probability predictions of F -and NO 3 were generated using a non-parametric co-kriging technique approach, aiding in the delineation of contamination hotspots. The integration of the USEPA human health risk assessment methodology with the urbanization index has revealed critical findings, identifying approximately 23% of the study area as being at high risk. This comprehensive approach, which synergizes geospatial analysis and statistical methods, proves to be highly effective in delineating priority zones for health intervention. The results highlight the pressing need for targeted mitigation measures and the implementation of sustainable groundwater management practices at regional, national, and global levels.

2025, Advances in Geoethics and Groundwater Management : Theory and Practice for a Sustainable Development

The Cape Flats Aquifer (CFA) is a primary coastal aquifer under the low-lying eastern suburbs and townships in the City of Cape Town (South Africa). It was identified as a major groundwater source since the 1970s but only intermittently explored and monitored until 2018, when Cape Town initiated an emergency programme in response to a prolonged drought. The objectives in this programme-still in progress-include detailed mapping of aquifer extent and properties, establishment and maintenance of a monitoring programme, and design and implementation of a Managed Aquifer Recharge abstraction scheme. Sustaining the potential of the CFA requires a holistic approach, considerate of the social, cultural and economic context. Support from the local communities is essential if this natural resource is to be harnessed for the benefit of all, as a supply and a means to store water for reuse from wastewater treatment works situated above the aquifer. CFA development can potentially help heal many of the historic societal wounds arising from the apartheid system of segregation and discrimination. The practices of transformative art may provide a practical and useful way to consider and structure the necessary "edges of engagement" in the socio-hydrogeological and environmental context.

2025, TELKOMNIKA Telecommunication Computing Electronics and Control

In theory, the resistivity value of the soil is one of the factors that must be taken into account when planning a grounding installation. The resistivity value of swamp soil is 30 Ωm, as per the general requirements for electrical installation of 2011 (PUIL 2011). This value is identical to the resistivity of the soil type in The Institute of Electrical and Electronics Engineers (IEEE standard 80 in 2000), where the wet soil type has a resistivity value of 100 Ωm. It is difficult for electrical engineers to design construction on swamp land because the standard's representation of the features of swamp land does not accurately reflect the types of swamps or wetlands that exist in reality. The focus of this investigation is the resistivity value of swamp soil types. The results of this investigation will make a scientific contribution to the clustering of land at each soil resistivity value in freshwater, brackish water, saltwater, and acidic water swamp land. These soils have pH values that range from 3.5 to above 6. The research on swamp land clustering has revealed that each swamp has a distinctive resistivity value for the different types of swamp soil.

2025, Environmental Science & Technology

This study investigates, for the first time, dual C-Cl isotope fractionation during anaerobic biodegradation of 1,2dichloroethane (1,2-DCA) via dihaloelimination by Dehalococcoides and Dehalogenimonas-containing enrichment cultures. Isotopic fractionation of 1,2-DCA (ε bulk C and ε bulk Cl ) for Dehalococcoides (-33.0 ± 0.4‰ and -5.1 ± 0.1‰) and Dehalogenimonas-containing microcosms (-23 ± 2‰ and -12.0 ± 0.8‰) resulted in distinctly different dual element C-Cl isotope correlations (Λ = Δδ 13 C/Δδ 37 Cl ≈ ε bulk C /ε bulk Cl ), 6.8 ± 0.2 and 1.89 ± 0.02, respectively. Determined isotope effects and detected products suggest that the difference on the obtained Λ values for biodihaloelimination could be associated with a different mode of concerted bond cleavage rather than two different reaction pathways (i.e., stepwise vs concerted). Λ values of 1,2-DCA were, for the first time, determined in two field sites under reducing conditions (2.1 ± 0.1 and 2.2 ± 2.9). They were similar to the one obtained for the Dehalogenimonas-containing microcosms (1.89 ± 0.02) and very different from those reported for aerobic degradation pathways in a previous laboratory study (7.6 ± 0.1 and 0.78 ± 0.03). Thus, this study illustrates the potential of a dual isotope analysis to differentiate between aerobic and anaerobic biodegradation pathways of 1,2-DCA in the field and suggests that this approach might also be used to characterize dihaloelimination of 1,2-DCA by different bacteria, which needs to be confirmed in future studies.

2025, Applied Water Science

Groundwater is considered the most important natural resource to mankind. Groundwater constitutes an important part of the hydrological cycle and is more prone to pollution. Dumpsite located in close proximity to groundwater resources is highly susceptible to leachates pollution. Predicting the susceptibility of groundwater pollution is crucial to address industrystandard codes for groundwater flow, contaminant transport, local to regional-scale water quality, and source water protection issues. Therefore, predicting heavy metal transport in groundwater around Lemna dumpsite in Cross River State, Nigeria, was examined. Soil samples were purposively collected with a soil Auger, along a straight line at (5 m, 25 m and 50 m) in the dumpsite. Water samples were purposively collected from five (5) boreholes close to Lemna dumpsite. The study utilized pumping test method to obtain data for the analysis of heavy metal transport in groundwater. Data analysis of the laboratory results of soil and borehole water quality focuses on arsenic, lead, cadmium, chromium, nickel, and mercury. Paired sample t test was used to analyse the soil and borehole water quality. Visual Modflow was also used to analyse the solute transport of heavy metals in groundwater around Lemna dumpsite. The paired sample t test of the analysis of heavy metals in soil exhibited a significant difference (p < 0.05) compared to National Environmental Standard Regulation and Enforcement Agency limits. The paired sample t test of the analysis of heavy metals in borehole water exhibited a significant difference (p < 0.05) compared to World Health Organization limits. The significant level indicates contamination of the soil and borehole water. The findings revealed a spatial spread of 259.2000 m 2 /day, with the contaminant travelling up to 94,608 m 2 /year. The extent of heavy metals concentration exhibited a maximum of 0.991 mg/l to a minimum of (-6.72 × 10-18 mg/l), with concentrations decreasing as the plume extend. The study recommends the need for remediation and stringent monitoring to mitigate heavy metal contamination of boreholes near Lemna dumpsite.

2025

Pengamatan terhadap uji aktivitas enzimatis mikroorganisme dilakukan untuk mengetahui kemampuan mikroba dalam menghasilkan enzim tertentu yang berperan dalam proses biokimia. Aktivitas enzim ditunjukkan melalui perubahan media uji, baik secara visual (misalnya zona bening atau perubahan warna) maupun secara kuantitatif. Hasil uji ini memberikan informasi penting mengenai potensi mikroorganisme dalam aplikasi industri, lingkungan, dan bioteknologi.

2025

Spatial Analysis Neural Network (SANN) is a specified neural network for conducting the spatial analysis of any type of variable. It provides a nonparametric mean estimator and also estimators of higher order statistics such as standard deviation and skewness. In addition, it provides a decision-making tool, including an estimator of posterior probability that a spatial variable at a given point will belong to various classes representing the severity of the problem of interest, and a Bayesian classifier to define the boundaries of subregions belonging to the classes. In this paper, the use of SANN as a decision-making tool to investigate an area contaminated by viruses in a groundwater system is illustrated. SANN provides two pieces of information; the contamination probability that the virus decay rate at a given point is less than a predefined threshold value, and the classification map defining contaminated and noncontaminated regions. The method is applied to several cases with varying threshold levels of the observed virus decay rate values, and the results show graphically the extent of the contaminated region and the change of the contamination probabilities.

2025, Geology Today

The title of this article is designed to provoke. Naturally occurring parameters are, by definition, not contamination. Nevertheless, nature is not necessarily nice, and naturally occurring trace toxins can be every bit as undesirable as... more

2025, Environmental Pollution

Mineralisation of the groundwater contaminant 2,6-dichlorobenzamide (BAM), a metabolite from the herbicide 2,6-dichlorobenzonitrile (dichlobenil), was studied in soil samples obtained from 39 locations previously exposed to dichlobenil. Rapid BAM mineralisation was detected in samples from six locations with 5.2e64.6% of the added BAM mineralised within 48e50 days. From one location rapid BAM mineralisation was observed in soil samples down to a depth of 2 m below the surface. One location with fast BAM mineralisation showed significant dichlobenil degradation activity with 25.5% of the added dichlobenil being mineralised within 50 days. By inoculating soil showing the fastest mineralisation of BAM into a mineral medium with BAM as the only carbon and nitrogen source an enrichment culture was established. Community analysis based on extracted DNA revealed a change of the bacterial community but without any clear indication of key members within the BAM-mineralising culture. Parallel cultivation resulted for the first time in the isolation of a BAM-mineralising bacterium, identified as an Aminobacter sp.

2025, Malaysian Journal of Microbiology

In Nigeria, inadequate supply of pipe borne water is a major concern; hence many homes have wells as a source of water for household uses. The groundwater of forty wells in Agbowo community was assessed for Total Aerobic Bacteria Counts (TABC) and Total Coliform Counts (TCC). The location and distances of wells from septic tanks were determined using the Global Positioning System (GPS) device and a tape rule respectively. All the wells sampled had high TABC (4.76±1.41 log CFU/mL) and TCC (2.29±0.67 log CFU/mL) counts which exceeded the international standard of 0 per 100 mL of potable water. There were no significant differences in the bacterial counts between covered and uncovered wells (p>0.05). The mean distance (8.93±3.61m) of wells from the septic tanks was below the limit (15.24 m or 50 ft) set by United State Environmental Protection Agency (USEPA). TABC increased with a decrease in distance between the wells and septic tanks though not significant (p<0.05). A very weak positive correlation (r 2 =0.021) ensued between the distance from septic tank and CC, while a weak negative correlation (r 2 = -0.261) was obtained between the TCC and TABC. This study accentuates the need to set standards for the siting of wells from septic tanks while considering all possible sources of well contamination as well as treatment of ground water before use.

2025, International Journal of Engineering Research and

Higher amount of nitrate in drinking water can cause severe methaemoglobinaemia and cancer in infants and adults. Land-uses and anthropogenic activities accompanied by hydrogeological conditions cause nitrate contamination in groundwater. This study aimed at estimating and identifying using box-plot, empirical approach and nitrate:chloride ratio (1:1 -8:1) as feasible methods to prove the possible sources in the western coastal area in Sri Lanka from Katana to Negombo. The outputs show that a high nitrate in groundwater of the area is originated mainly from on-site sanitations (i.e. soakage, pit latrine, septic tank) under denser populated settlements, while agriculture plays as a secondary source. Current groundwater nitrate levels from analyzed water wells indicated that about 30% of the water samples exceed the Maximum allowable value of 10 mg/L NO3 -, however, samples with nitrate greater than 50 mg/L were not found. Denitrification processes may also contribute regulate nitrate levels in the area. Although nitrate concentration at present is not alarmingly high in the area, an increasing trend of contamination is expected with population, settlements and agriculture growth. Therefore, appropriate management and special care from relevant parties should be set up to rectify the problems and to use precious groundwater resource sustainably.

2025

In this paper, we present an experimental approach on the study of the evolution of residual deformations through the wall of polyethylene pipes- HDPE 80 on the mechanical behavior on one hand, and on the other hand, on the effect of chemical agents present in the soil and which can enter into interaction with the embedded tubes. The results indicate that the polyethylene is highly influenced by the presence of acids and solvents that degrade it. The modeling of constraints and residual deformations obeys to very different equations in comparison with those governing the solute shaping.

2025, Int.J.Curr.Microbiol.App.Sci

Water pollution due to chemical constituents, Metal ions and micro organisms is
one of the serious environmental problems, which has greatly impacted human
health. The aim of the present study is to characterize the Rural Water Supply
waters collected before and after treatment from Mandal Head Quarters of
Iragavaram and Undrajavaram of Eluru Revenue division in West Godavari district
during pre and post monsoon seasons to estimate the chemical contamination status
and metal toxicity. The parameters characterized include pH, Electrical
conductivity (EC), Total Dissolved solids (TDS), Total hardness (TH), Total
Alkalinity (TA), Na, K, Calcium and Magnesium, Chloride, Sulphate, Nitrate,
Fluoride, Phosphate and Metal ions Viz., Li, Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn,
As, Rb, Sr, Ag, Cd, Cs, Ba, Tl, Pb and U. The waters are further characterized for
identification of Bacterial spps. The research results revealed that the presence of
higher levels of certain chemical parameters and presence of bacteria confirmed
their unsuitability for drinking and domestic applications. The waters are to be
treated by ultra and nano filtration techniques to reduce the total dissolved solids
and disinfection and sterilization methods are to be applied for removing bacterial
contamination before use of these waters for drinking and domestic purposes

2025, Environmental Pollution

Twenty-two years after the last application of ring-14 C-labeled atrazine at customary rate (1.7 kg ha -1 ) on an agriculturally used outdoor lysimeter, atrazine is still detectable by means of accelerated solvent extraction and LC-MS/MS analysis. Extractions of the 0-10 cm soil layer yielded 60% of the residual 14 C-activity. The extracts contained atrazine (1.0 µg kg -1 ) and 2-hydroxy-atrazine (42.5 µg kg -1 ). Extractions of the material of the lowest layer 55-60 cm consisting of fine gravel yielded 93% of residual 14 C-activity, of which 3.4 µg kg -1 was detected as atrazine and 17.7 µg kg -1 was 2-hydroxy-atrazine. The detection of atrazine in the lowest layer was of almost four times higher mass than in the upper soil layer. These 1 findings highlight the fact that atrazine is unexpectedly persistent in soil. The overall persistence of atrazine in the environment might represent a potential risk for successive groundwater contamination by leaching even after 22 years of environmental exposure.

2025

The expansion of the Integrated Groundwater Monitoring Network (RIMAS), a project by the Geological Survey of Brazil, made possible the construction of eight piezometers in the sedimentary basin of Acre, Acre state, Brazil, in 2013 and 2014. Their allocations took into account criteria intrinsic to hydrogeology, superficial distribution in the aquifer, logistical aspects of access and security, as well as socio-economic aspects and agreements with the surface owners.

2025

Se han realizado varios modelos numericos con el fin de probar conjeturas o integrar los datos que se han ido recogiendo en relacion con los trabajos hidrogeologicos asociados a la rotura de la balsa de residuos mineros. Las escalas de los modelos son muy variables y abarcan desde los 30 cm de las columnas de laboratorio hasta los casi 100 km del acuifero regional. En este capitulo se recogen cuatro modelos. El mayor es el del acuifero de Almonte-Marismas, que ha permitido representar con gran precision el funcionamiento del acuifero durante 30 anos. Los resultados confirman que la posible contaminacion quedara en todo caso confinada al acuifero aluvial del Guadiamar y que solo puede descargar al sector del acuifero Almonte-Marismas confinado bajo las marismas. Por ello, se ha simulado en detalle la conexion entre estos dos acuiferos, mediante un modelo 3D que incorpora la geologia con un gran nivel de detalle. Este segundo modelo muestra que, suponiendo que la contaminacion llegue ...

2025

The sealing mechanisms for soils being infiltrated by dairy and swine slurries were investigated using laboratory infiltration columns. Physical mechanisms were found to be predominant especially for dairy slurries. Biological mechanismsinterveneto strengthen physical seals only where ambienttemperatures exceed 15°C. Biological mechanisms are especially important in the sealing of soils by swine slurries as their physical mechanisms are weaker than those of dairy slurries. Chemical mechanisms were found to be insignificant.

2025, Environmental Geology

The Gaza Strip is a very narrow and highly populated area along the coast of the Mediterranean Sea (360 kin2). Human activities greatly threaten the groundwater resources in the area, while the unconfined nature of some parts of the coastal main aquifer favors groundwater contamination. Recent investigations show contamination of the aquifer with organic substances from detergents, agrochemicals, sewage (cesspools), and waste degradation. These effects enhance each other because there is no recycling industry, sewage system, or any type of environmental protection management at present. Inorganic contamination results from overpumping, which increases the salinity of the groundwater. Seawater intrusion also increases the salinity of the groundwater that are used for drinking and agricultural purposes. Consequently, at present about 80 percent of the groundwater in the Gaza Strip is unfit for both human and animal consumption. Solutions are very urgently needed for these problems in order to prevent the spread of dangerous diseases.

2025, Environmental and planning law journal

2025, Journal of Contaminant Hydrology

The Upper Tietê is prominent for being the basin with the highest contaminated areas in São Paulo, Brazil, and these areas significantly compromise the quality of groundwater in the basin, directly affecting the resident population. Acknowledging the criticality of formulating indicators for effective aquifer management, we attempted to identify and assess the risk, vulnerability, and contamination degrees of aquifers and wells in the Upper Tietê Basin. To do this, we applied the aquifer vulnerability index (AVI) method to evaluate the aquifer vulnerability in the region; the delineation and identification of wellhead protection areas and at-risk wells, respectively; and the integrated risk index by integrating the data on social and aquifer vulnerabilities, hazards, and exposure. As inputs for AVI analysis, we estimated the hydraulic conductivity and unsaturated-sedimentary-layer thickness of the aquifers. The hydraulic activity, which was estimated by an empirical flow method incorporating pipe-radius data, was interpolated by co-kriging (using well-flow parameters as auxiliary variables), and unsaturated thickness was interpolated by ordinary kriging. The results revealed the high vulnerability of the aquifers to contamination, mainly because of their minimal unsaturated-layer thicknesses. Furthermore, 7958 at-risk wells were identified around the basin (77.15 %), and the outskirts of the basin accounted for the most vulnerable municipalities. Further, the wellhead protection areas were also delimited by interpolating stabilization flow by indicator kriging. Furthermore, we developed an innovative social vulnerability indicator for groundwater usage and integrated it with AVI analysis. Overall, our findings offer relevant insights into aquifer management and contamination control, mainly because of the holistic approach, serving as a basis for identifying regions with the highest contamination risks for timely prevention and mitigation through appropriate actions.

2025, Journal of Sciences, Islamic Republic of Iran

Dar-Zarrouk criteria were used to explore a study region in southwestern Nigeria that was covered by a crystalline groundwater basement complex to illustrate the possibility for groundwater protection. This was accomplished by determining if the research area's protective potentials were predominantly low, weak, moderate, or good. The study's protective potential was calculated using physical subsoil layer data such as apparent resistivity and layer thickness values. For vertical electrical probes, the Schlumberger electrode array arrangement was employed, and twenty probe locations were defined depending on the spread allowed and subsurface depth. The Dar-Zarrouk parameters revealed that there was 70% evidence of poor/weak groundwater protection potential within the study area, implying that the availability of profitable groundwater quality within the study area is envisaging a tragic development due to contaminating activities that could percolate from the topsoil to the subsoil in the near future. As a result, frequent assessment of adequate water quality development and standards is recommended within the environment for the safe use of groundwater resources.

2025, 1st International Conference on Transformative Applied Research

The main water resource of Chunnakam, Sri Lanka is the groundwater supply of the Chunnakam aquifer, which is used for all drinking, domestic, agricultural, and industrial purposes. However, due to the fuel smell of water, which has been continuously observed in the agro wells near the Chunnakam Power Station (CPS), many researches have been conducted and have witnessed that the wells near the CPS are contaminated and not suitable for usage. This has occurred mainly due to the improper waste discharge of the CPS. This study analyzes the variation of contamination levels of the groundwater in Chunnakam area with the distance to the CPS, concerning time, and according to the type of wells, and further the risk analysis of environmental, economic, and social impact of this contamination. By analyzing the data collected by previous researches, it was observed that, the oil and grease contamination levels decreased with the increase of the distance from CPS, while limiting the contaminated wells within a 1.5 km radius with CPS. The 73% of contaminated wells, in which the oil and grease concentration is more than the standard value of 1.0 mg/l, in 2013/14 has been reduced to 4% in 2016/17, expressing the decreasing pattern of oil and grease contamination level with time. Further, according to the analysis, the type of well does not affect the contamination level significantly. While the Lead, Chromium, and Arsenic concentrations of the groundwater in Chunnakam area are at safe levels, the nitrate-nitrogen concentration and aerobic and anaerobic bacterial counts are higher than the standard values making the water not suitable for usage. Moreover, all these contaminations have created environmental, economic, and social impacts among the residents of Chunnakam area.

2025, Frontiers in Scientific Research and Technology

Water from the Nile River is a fundamental water supply, while groundwater is a secondary source used for domestic, industrial, and agricultural uses in the Sohag region. Groundwater quality assessment requires additional focus due to the expanding urbanization, agriculture, and population in these dry regions, as well as the scarcity of water resources and water pollution. The evaluation of groundwater quality was implemented to determine suitable safety factors for different uses. Geographically, Araya and Gz.Shandwil regions relate to Sohag governorate and is important for residence and agriculture communities to supplement water for drinking, livestock, domestic, and irrigation uses, so great efforts were performed to evaluate water resources in the studied area. Even some large settlements use groundwater for irrigation and drinking purposes. Araya and Gz.Shandwilvillages have groundwater that founds in a Pleistocene aquifer. In all groundwater samples, the principal ions (Na + , K + , Ca 2+ , Mg 2+ , HCO3-, SO4 2-, and Cl-) and minor chemical components (NO3-, NH4 +) were analyzed. The investigation goals are to explain the potential impact of urbanization, and industrial and agricultural activities on groundwater characteristics and their purposes in different fields. The water quality is influence by natural and anthropogenic sources, which govern groundwater characteristics in the area. Na+K+HCO3 facies predominance in Arya village and Ca+Mg+HCO3 facies predominance in Gz.Shandwil village. Most of groundwater samples are suitable for drinking and Araya samples are low suitable for irrigation purposes and unsuitable for paper,fruits and vegetables industries, while Gz.Shandwil are suitable for irrigation, paper, fruits and vegetables industries.

2025

Agricultural production with excessive amounts of fertilizers and agrochemicals has become a serious concern all over the world. Statistics show that applications of fertilizers have grown over the years and remarkably in Asia. Therefore, this research attempted to study the relationship between the knowledge of farmers on the environmental issues or 'environmental awareness' on environmentally responsible behavior or 'environmental stewardship', by considering a sample of farmers from Kalpitiya, Sri Lanka, where soil and ground water is rapidly degrading due to overuse of fertilizer. Environmental awareness was measured in terms of an index developed using the answers to a set of Likert type statements and was related to stewardship behavior measured in terms of willingness to adopt ecofriendly agricultural practices in a Bayesian framework. A Bayesian probit model was estimated with non-informative priors for model parameters with a post burn-in sample of 80,000 iterations. Results revealed that environmental awareness is strongly linked with the intention to adopt ecofriendly agricultural practices. Human capital available to farmer moderates the impacts positively, while the farm size moderates it negatively.

2025, Water Research

A novel aerated treatment pond for enhanced biodegradation of groundwater contaminants was tested under field conditions. Coconut fibre and polypropylene textiles were used to encourage the development of contaminant-degrading biofilms. Groundwater contaminants targeted for removal were benzene, methyl tert-butyl ether (MTBE) and ammonium. Here, we present data from the first 14 months of operation and compare contaminant removal rates, volatilization losses, and biofilm development in one pond equipped with coconut fibre to another pond with polypropylene textiles. Oxygen concentrations were constantly monitored and adjusted by automated aeration modules. A natural transition from anoxic to oxic zones was simulated to minimize the volatilization rate of volatile organic contaminants. Both ponds showed constant reductions in benzene concentrations from 20 mg/L at the inflow to about 1 mg/L at the outflow of the system. A dynamic air chamber (DAC) measurement revealed that only 1% of benzene loss was due to volatilization, and suggests that benzene loss was predominantly due to aerobic mineralization. MTBE concentration was reduced from around 4 mg/L at the inflow to 3.4-2.4 mg/L in the system effluent during the first 8 months of operation, and was further reduced to 1.2 mg/L during the subsequent 6 months of operation. Ammonium concentrations decreased only slightly from around 59 mg/L at the inflow to 56 mg/L in the outflow, indicating no significant nitrification during the first 14 months of continuous operation. Confocal laser scanning microscopy (CLSM) demonstrated that microorganisms rapidly colonized both the coconut fibre and polypropylene textiles. Microbial community structure analysis performed using denaturing gradient gel electrophoresis (DGGE) revealed little similarity between patterns from water and textile samples. Coconut textiles were shown to be more effective than polypropylene fibre textiles for promoting the recruitment and development of MTBE-degrading biofilms. Biofilms of both textiles contained high numbers of benzene metabolizing bacteria suggesting that these materials provide favourable growth conditions for benzene degrading microorganisms.

2025, Biodegradation

BTEX compounds such as benzene are frequent soil and groundwater contaminants that are easily biodegraded under oxic conditions by bacteria. In contrast, benzene is rather recalcitrant under anaerobic conditions. The analysis of anoxic degradation is often hampered by difficult sampling conditions, limited amounts of biomass and interference of matrix compounds with proteomic approaches. In order to improve the procedure for protein extraction we established a scheme consisting of the following steps: dissociation of cells from lava granules, cell lysis by ultrasonication and purification of proteins by phenol extraction. The 2D-gels revealed a resolution of about 240 proteins spots and the spot patterns showed strong matrix dependence, but still differences were detectable between the metaproteomes obtained after growth on benzene and benzoate. Using direct data base search as well as de novo sequencing approaches we were able to identify several proteins. An enoyl-CoA hydratase with cross species homology to Azoarcus evansii, is known to be involved in the anoxic degradation of xenobiotics. Thereby the identification confirmed that this procedure has the capacity to analyse the metaproteome of an anoxic living microbial community.

2025, Revista de la …

Resumen. Se estudió la extracción de hierro (II) y níquel (II) a partir de sulfatos empleando como extractante al ácido di-2-etil hexil fosfórico (D2EHPA) y al queroseno como diluyente, a 298 K, mediante la implementación de un proceso... more

2025, Journal of environment and earth science

This research involved the use of electrical resistivity technique which is considered most appropriate for subsurface investigation of structures and/or lithologies associated with the occurrence of groundwater; to investigate the geo-electric characteristics of the subsurface formations that underlie the study area. The aim was to provide a data base for sustainable groundwater development in the study area. The geophysical investigation involved the acquisition of twenty two ( ) vertical electrical sounding (VES) data via the ABEM terrameter SAS 300C model using the Schlumberger configuration. These were quantitatively and qualitatively analysed using partial curve matching and computer iteration to obtain subsurface information in the study area. The results obtained from the interpretation of the VES data show earth models with geo electric layers ranging from three (3) to four (4). The representative type curves are H, A, HA, QH, HK and KH types. The subsurface is made up of four layers, namely the topsoil, the weathered layer, the partially weathered/fractured bedrock and the fresh bedrock, with the weathered layer and the partially weathered/fractured bedrock layers constituting the aquifer units of generally low, medium and high groundwater yielding capacities.

2025, HAL (Le Centre pour la Communication Scientifique Directe)

HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

2025

This research have been done onusingwild-typebacteriaand endomycchorhiza; oil bacter1 (Pseudomonas sp., Alcaligenessp., Flavobacteriumsp.,), Oilbacter2 (Bacillus megaterium, Alcaligenessp., Flavobacteriumsp.)and endomycchorhiza biounpadin oily sludge phytoremediationdose30%, 35%withplantsengon(Paraserianthes falcatariaL.Nielsen). The study was conductedwithan experimental methoduse a Completely RandomizedDesign(CRD) with 4combinationbetween the consortiumof bacteriain different doses with 3replications.The mediumused is amixture ofoily sludgewith soilandsandin the ratio2:1. Mediumiscompostedfor 1month, then plantedsengoninoculated endomycchorhiza aged1 monthand leftfor 8months. The parametersanalyzedwere:biosurfactantproduction, oil content/TPH(Total Petroleumhydrocarbon(%),the population of bacteria/TPC(Total PlateCount) (CFU /colonyformingunits), pH, humidity(%), infectionendomyccorhizapercentage(%). The resultsupto 8monthsshowedthat thecombination of consortiumof oilbacter 1(Pseu...