Search

Small intermountain river basins are most suitable for developing new methods to estimate water balance due to their well-defined catchment boundaries, relatively rapid runoff processes, and accessible landscapes for study. In general terms, dissecting the hydrograph of a small mountain river requires calibration of the flow model against multi-year data sets, including (a) glacier mass balance and snow water content, (b) radiation balance calculation, (c) estimation of the groundwater contribution, and (d) water discharge measurements. The minimum primary data set is limited to the precipitation and temperature distributions at the catchment. This approach postulates that the conditions for the formation of all components of river flow are known in advance. It is reduced to calculating the dynamic balance between precipitation (input part) and runoff, ablation, and evaporation (output part). In practice, accurately accounting for the inflow and outflow components of the balance, as well as the impact of regulating reservoirs, can be a challenging task that requires significant effort and expense, even for the extensively researched catchments. Our studies indicate the potential benefits of an approach based on one-time, but detailed, observations of stable isotope composition, temperature, and water chemistry, in addition to standard datasets. This paper presents the results of the 2022–2023 work conducted in the basin of the small mountain river Ala-Archa, located on the northern slope of the Kyrgyz Range in Tien-Shan, which was chosen as an example due to its well-studied nature. Our approach could identify previously unknown factors of flow formation and assess the time and effectiveness of work in similar conditions. [ABSTRACT FROM AUTHOR]

Springs provide ideal monitoring points for groundwater chemistry, which are important for managing groundwater resources. The chemistry of these spring waters aggregate geochemical reactions along the flow path. In this paper, part two of a two-part investigation, 104 perennial springs in the classic karst landscape of the Mitchell Plateau, Indiana, USA were sampled at base flow. Many of these springs are historically important for domestic, agricultural, commercial, and recreational use. Multifactor analysis of field measurements, principal ions, and stable isotopes revealed five primary clusters of springs emerging from the Mitchell Aquifer. Two clusters represented earth-alkaline-type karst groundwater that were discriminated by temperature and inorganic carbon concentration. Two other clusters comprised mineralized alkaline-earth-type groundwater with excess alkalis and elevated sulfate. The fifth cluster appeared to be groundwater that included meteoric and mineralized sources. Using the longitudinal data over two years from part one of this investigation, two mixing lines were used to describe the data set. The mixing lines pointed to sources of sulfur in mineralized springs from deep brines and from evaporite dissolution. Collectively, these regional data allow for a better delineation of water types and differentiation between the Upper and Lower Mitchell Aquifer. [ABSTRACT FROM AUTHOR]

Flotation performance can significantly be affected by seasonal variations due to the changes in water temperature and pulp temperature, type and concentration of dissolved ions in process water. Extreme temperature conditions could be the major factor affecting flotation performance and mask the influence of water chemistry. Therefore, the interactive effects of the temperature and water chemistry should be taken into consideration, particularly for mine sites experiencing extreme temperature conditions. In this paper, effects of temperature, sulphate (SO42−), thiosulphate (S2O32−) and calcium (Ca2+) ions on the flotation performance of a Cu-Pb-Zn complex sulfide ore were investigated using a statistical experimental design and modelling approach. The results were evaluated using ANOVA and regression analysis to determine the significant parameters and derive individual regression models for each flotation response using Design Expert software version 6.0.8. Individual regression models were developed for mass pull, water recovery, grade and recovery of the sulfide minerals using the statistically significant main effects and their interactions. The models were used to determine the concentration of the dissolved ions and pulp temperature required to achieve the maximum zinc recovery, maximum zinc grade or the optimum zinc grade and recovery. The results showed that the water chemistry (i.e., the concentrations of Ca2+, SO42− and S2O32−) affected the flotation performance significantly at low temperature (25 °C). At high pulp temperature (60 °C), however, the temperature was the dominant parameter and masked the effects of water chemistry. Details of the statistical experimental design, discussions of the effects of experimental factors and their interactions on flotation performance, and the development of regression models are presented in this paper. [ABSTRACT FROM AUTHOR]

During the power operation of the primary loop of a water cooled–water moderated energy reactor (WWER), the water chemistry evolves from a high-boron high-potassium composition to significantly lower concentrations of both constituents at the end of a campaign, and the Li concentration reaches ca. 0.7–0.9 ppm. In the present paper, the effect of primary water chemistry evolution during operation on the corrosion rate and conduction mechanism of oxides on Alloy 690 is studied by in situ impedance spectroscopy at 300 °C/9 MPa during 1-week exposures in an autoclave connected to a re-circulation loop. At the end of exposure, the samples were anodically polarized at potentials −0.8 to −0.1 V vs. SHE to evaluate the stability of the passive oxide. Simultaneously exposed samples of Alloy 690 were subsequently analyzed by XPS to estimate the thickness and in-depth composition of oxides. Impedance data were quantitatively interpreted using the mixed-conduction model (MCM) for oxide films. The effect of water chemistry evolution on the corrosion rate and conduction mechanism in the oxide on Alloy 690 in a primary coolant is discussed based on the obtained parameters. [ABSTRACT FROM AUTHOR]

Zirconium alloy (Zircaloy-4) is widely used for fuel cladding in the Canadian Deuterium Uranium (CANDU) heavy water reactors. However, degradation due to waterside corrosion can limit the in-reactor design life of the nuclear fuel. For this reason, efforts must be made to understand the mechanisms of corrosion and to mitigate its effects. The purpose of the experimental research related to this work consists of the assessment of corrosion of the CANDU fuel cladding material. The paper presents the results obtained by in-situ monitoring of the Pressurized Heavy Water Reactor (PHWR) water chemistry effect on fuel cladding corrosion, Zircaloy-4. Optical metallographic and Scanning Electron Microscopies (SEM), as well as X-ray diffraction (XRD) analysis, were used to evaluate the corrosion behavior of the fuel cladding material, Zircaloy-4 coupons, exposed in a Primary Heat Transport System (PHTS) autoclave system. The obtained results are useful for characterizing the corrosion behavior of Zircaloy-4 coupons exposed in the autoclave system at Cernavoda NPP for long periods. [ABSTRACT FROM AUTHOR]

Primary water stress corrosion cracking (PWSCC) of Alloy 600 remains an important degradation phenomenon in PWRs. In particular, the susceptibility to the PWSCC initiation at 290°C is of recent interest because that is one of the typical temperatures of the primary water in contact with Alloy 600 which remains in PWRs. In this paper, oxide film formed on Alloy 600 in simulated primary water at 290°C was analyzed by X-ray absorption fine structure (XAFS) measurements at the Fe K-edge. For the preparation of the oxide film, Alloy 600 was immersed in simulated primary water with dissolved hydrogen (DH) concentration of 5 or 30 ml/kg-H2O. The near edge region of the XAFS suggested that the oxide film for 5 ml/kg-H2O DH had a larger Fe3+/Fe2+ ratio than for 30 ml/kg-H2O DH. Additionally, the extended region of the XAFS revealed that Fe3+ mainly occupied the octahedral site of the spinel oxide. Previous reports indicate that an Fe3+-rich spinel oxide is less defective and protective against PWSCC initiation. Therefore, our results suggest that the lower DH concentration (5 ml/kg-H2O) could potentially mitigate the susceptibility of Alloy 600 to the PWSCC initiation at 290°C. [ABSTRACT FROM AUTHOR]

Sandstone from the Longshan Grottoes in Taiyuan, China, was the research object of this paper. The sandstone samples were soaked in distilled water, Na2SO4 solution, and NaCl solution and subjected to freeze–thaw testing. Sandstone specimens were treated with 0, 5, 10, 15, 20, 25, and 30 freeze–thaw cycles. The mass ratio, P-wave velocity, surface hardness, uniaxial compressive strength, and other physical-mechanical features of rock samples were measured after different numbers of cycles. The results of mercury injection, scanning electron microscopy, and X-ray diffraction were combined to explore the damage mechanisms and characteristics of the rock samples under the combined action of chemicals and freeze–thaw cycles. It was found that the damage degree of sandstone increased logarithmically with the number of cycles, with Na2SO4 solution causing the most damage. Damage variables D of the samples soaked in distilled water, Na2SO4 solution, and NaCl solution after 30 freeze–thaw cycles were 3.89%, 6.51%, and 4.74%, respectively. The difference in damage between the solutions is caused by the combination of frost heave, dissolution, and salt crystallization, and the damage process generally occurs from the inside and the outside and is manifested as an increase in the number of macropores and the appearance of new pores. Freezing–thawing and salt action are important causes of the powdering and detachment of sandstone in the Longshan Grottoes. [ABSTRACT FROM AUTHOR]

Climate change is predicted to have dramatic effects on Arctic freshwater ecosystems through changes to the abiotic template that are expected to influence biodiversity. Changes are already ongoing in Arctic systems, but there is a lack of coordinated monitoring of Arctic freshwaters that hinders our ability to assess changes in biodiversity.To address the need for coordinated monitoring on a circumpolar scale, the Arctic Council working group, Conservation of Arctic Flora and Fauna, established the Circumpolar Biodiversity Monitoring Program, which is an adaptive monitoring program for the Arctic centred around four ecosystem themes (i.e., Freshwater, Terrestrial, Coastal, Marine). The freshwater theme developed a monitoring plan for Arctic freshwater biodiversity and recently completed the first assessment of status and trends in Arctic freshwater biodiversity.Circumpolar Biodiversity Monitoring Program–Freshwater has compiled and analysed a database of Arctic freshwater monitoring data to form the first report of the state of circumpolar Arctic freshwater biodiversity. This special issue presents the scientific analyses that underlie the Circumpolar Biodiversity Monitoring Program–Freshwater report and provides analyses of spatial and temporal diversity patterns and the multiple‐stressor scenarios that act on the biological assemblages and biogeochemistry of Arctic lakes and rivers.This special issue includes regional patterns for selected groups of organisms in Arctic rivers and lakes of northern Europe, Russia, and North America. Circumpolar assessments for benthic diatoms, macrophytes, plankton, benthic macroinvertebrates, and fish demonstrate how climate change and associated environmental drivers affect freshwater biodiversity. Also included are papers on spatial and temporal trends in water chemistry across the circumpolar region, and a systematic review of documented Indigenous Knowledge that demonstrates its potential to support assessment and conservation of Arctic freshwaters.This special issue includes the first circumpolar assessment of trends in Arctic freshwater biodiversity and provides important baseline information for future assessments and studies. It represents the largest compilation and assessment of Arctic freshwater biodiversity data to date and strives to provide a holistic view of ongoing change in these ecosystems to support future monitoring efforts. By identifying gaps in monitoring data across the circumpolar region, as well as identifying best practices for monitoring and assessment, this special issue presents an important resource for researchers, policy makers, and Indigenous and local communities that can support future assessments of ecosystem change. [ABSTRACT FROM AUTHOR]

The Okavango Delta in southern Africa has been the subject of geomorphological and hydrological investigations since the 1970s. In the early 1990s, McCarthy and co‐workers developed a geomorphological and hydrological model which describes the processes that give rise to the gently undulating topography and the lack of saline surface water in this semi‐arid environment. This model is based on extensive investigations of soil and water chemistry conducted across the Okavango Delta, and has been subject to rigorous testing by a number of independent researchers. In their recent paper, Jolivet et al. (2023, https://doi.org/10.1029/2023GC010978) proposed an alternative hydrological model based on chemical and mineralogical analyses of samples from six auger holes drilled at a site on the lower fringe of the permanent swamp. We provide a critique of their model and explain how this model cannot describe the geohydrological functioning of the Okavango Delta. Jolivet et al. suggest there are two shallow aquifers, one hosted in sand and the other in clay‐rich material. Previous studies of subsurface soils on 18 islands have failed to reveal a deeper clay‐rich layer. Rather, the shallow groundwater is laterally fully connected and salinity varies in response to evapotranspiration. We attribute REE fractionation in subsurface soils observed by Jolivet et al. to be caused by the precipitation of calcite from groundwater which strongly accumulates REE. We are of the opinion that Jolivet et al. have insufficient data to suggest revisions to the current understanding of the functioning of the Okavango hydrological and sedimentological system. Key Points: The model proposed by Jolivet et al. cannot describe the geohydrological functioning of the Okavango DeltaPrevious studies of subsurface soils on 18 islands have failed to reveal the presumed deeper clay‐rich layerWe attribute REE fractionation in subsurface soils observed by Jolivet et al. to be caused by the precipitation of calcite from groundwater [ABSTRACT FROM AUTHOR]

Groundwater age or residence time is important for identifying flow and contaminant pathways through groundwater systems. Typically, groundwater age and age distributions are inferred via lumped parameter models based on measured age tracer concentrations. However, due to cost and time constraints, age tracers are usually only sampled at a small percentage of the wells in a catchment. This paper describes and compares two methods to increase the number of groundwater age data points and assist with validating age distributions inferred from lumped parameter models. Two machine learning techniques with different strengths were applied to develop two independent metamodels that each aim to establish relationships between the hydrochemical parameters and the modelled groundwater age distributions in one test catchment. Ensemble medians from the best model realisations per age distribution percentile were used for comparison with the results from traditional lumped parameter models based on age tracers. Results show that both metamodelling techniques predict age distributions from hydrochemistry with good correspondence to traditional lumped parameter model (LPM)-derived age distributions. Therefore, these techniques can be used to assist with the interpretation of lumped parameter models where age tracers have been sampled, and they can also be applied to predict groundwater age distributions for wells in a similar hydrogeological regime that have hydrochemistry data available but no age tracer data. [ABSTRACT FROM AUTHOR]

The ExoMars Trace Gas Orbiter instruments, Nadir and Occultation for Mars Discovery and Atmospheric Chemistry Suite have provided vertical profiles of H2O and HDO mixing ratios in the presence and absence of Global Dust Storm 2018. These observations are carried out in the lower atmosphere at SZA ∼ 71° of northern mid latitude (∼55°N, 130°E). Using NOMAD observations, we developed chemical models 1 and 2 for dust and non‐dust storm conditions, respectively. The production/loss rates of H2O, HDO and D2O and the densities of water, nitrogenated and deuterated cluster ions (H2O+, D2O+, HDO+, H+(H2O)n, D+(D2O)n, H+(HDO)n, CO4−, CO3−, CO3−(H2O)n, CO3−(D2O)n, CO3−(HDO)n, NO2−(H2O), NO2−(HDO), and NO2−(D2O) (for n = 1 to 5)) are estimated from these models between 10 and 70 km. We have used two ionization sources: (a) Galactic Cosmic Rays (GCR) and (b) hard X‐ray in both models. The D peak density produced by GCR is lower by a factor of ∼5 than that produced by the hard X‐rays. In model 1, the electron densities were increased by a factor of ∼2–3 than that produced by model 2. The estimated production/loss rates of H2O, HDO, and D2O are also larger by an order of magnitude in model 1 than that estimated by model 2. Plain Language Summary: The chemistry of the lower ionosphere of Mars is very complex because of the rapidly increasing number of ion species at larger masses. It couples ion‐neutral, electron‐neutral, dissociation of positive/negative ions, electron detachment, ion‐ion and ion‐electron recombination processes through various chemical reactions. In this paper we have performed ionospheric modeling and used Nadir and Occultation for Mars Discovery observations as inputs for the model. The chemistry of water, nitrogenated and deuterated cluster ions were studied. The production/loss of H2O, HDO, and D2O are also estimated during Global Dust Storm 2018. One‐dimensional chemical model 1 and 2 have been developed to estimate the densities of these cluster ions in the presence and absence of dust storm respectively. In this modeling, two ionization sources, (a) Galactic Cosmic Rays and (b) hard X‐ray, are used. In model 1 estimated production/loss rates of H2O, HDO, and D2O are increased by an order of magnitude than that estimated by model 2. The estimated densities are also larger in model 1 by a factor of 2–3 than that produced by model 2. There is no measurement of ion/electron density in the lower ionosphere of Mars. In the absence of measurements, predicted results improve our understanding of the ionospheric chemistry of Mars and its environment. Key Points: The densities of water, nitrogenated and deuterated cluster ions in the presence and absence of Global Dust Storm 2018 are estimatedThe Trace Gas Orbiter data (H2O and HDO) are used for the first time in the modeling of the lower ionosphere of MarsThe production and loss rates of H2O, HDO, and D2O are increased by one order of magnitude during the dust storm [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Naturalium Universitatis Pekinensis is the property of Editorial Office of Acta Scientiarum Naturalium Universitatis Pekinensis and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carbonic acid and sulfuric acid speleogenesis describe a dichotomy between epigenetic and hypogenetic caves and carbon and sulfur cycling in karst, but do not acknowledge the global spectrum of cave formation. This paper, part one of a two-part investigation, tests and revises speleogenetic models from a classic karst landscape using dissolved ion concentrations δ13CDIC, and δ34S in water samples collected at four sites across the Bluespring and Lost River karst basins in the Mitchell Plateau, Indiana, USA. Analyses revealed elevated sulfur in both karst basins but differently sourced; H2S (δ34S = −14.2‰) evolved from petroleum seeps in Bluespring Caverns accounted for up to 61% of sulfur in the cave stream, while evaporite beds (δ34S = [+14.50‰, +17.91‰]) of the St. Louis Limestone contributed up to 100% of sulfur at Orangeville Rise, a terminal spring of the Lost River karst basin. These results have implications for carbon–sulfur cycle linkages, particularly the potential acceleration of carbon flux from sulfuric acid dissolution in otherwise epigenetic settings. We suggest a new paradigm for speleogenesis in the North American midcontinent—speleogenesis in the Mitchell Plateau and similar settings is not epigenetic or hypogenetic, but instead polygenetic with competing chemical processes varying across space and time. [ABSTRACT FROM AUTHOR]

Groundwater resource management is crucial for promoting sustainable development in areas with surface water scarcity, such as Hua County in China. This paper aims to estimate groundwater recharge and evaporation during the pre- and post-rainy seasons in Hua County. The non-equilibrium evaporation model was established to quantify the degree of evaporation. Ternary end-member mixing analysis (EMMA) was used to evaluate the contributions of recharge sources to groundwater recharge. The concentrations of major ions in surface water and groundwater showed some differences, which may be due to differences in their lithological classes and hydrogeochemical evolution. The ion concentrations of both surface water and groundwater were observed to be lower in the post-rainy season, because rainfall infiltration during the rainy season diluted ion concentrations. The Gibbs diagram, end-member diagram, and δ2H versus δ18O diagram all revealed that groundwater was affected by evaporation to some extent, especially in the pre-rainy season. The non-equilibrium evaporation model showed that the remaining proportions of evaporation calculated using 18O and 2H were 0.96 and 0.94%, respectively, during the pre-rainy season and 0.97% and 0.96%, respectively, during the post-rainy season. According to EMMA, the mean contributions of subsurface lateral flow, precipitation infiltration, and river percolation to groundwater were 47%, 28%, and 25%, respectively, during the pre-rainy season and 57%, 30%, and 13%, respectively, in the post-rainy season. The findings of the present study demonstrated that integration of hydrochemistry and isotopic signatures supports better understanding of groundwater recharge and evaporation processes. [ABSTRACT FROM AUTHOR]

Copyright of Hydrogeology & Engineering Geology / Shuiwendizhi Gongchengdizhi is the property of Hydrogeology & Engineering Geology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Monitoring the condition (water quality, biodiversity, hydromorphology) of small water bodies presents a challenge for the relevant authorities in terms of time and resources (labour and financial) due to the extensive length of the stream network or the sheer number of small standing water bodies. Citizen science can help address information gaps, but the effort required should not be underestimated if such projects are to generate reliable and sustained data collection. The overall aim of this paper is to propose a framework for operationalisation of citizen science targeting collection of data from small water bodies. We first consider the data gaps and the elements (water chemistry, ecology, hydromorphology) to be addressed, in order to define where citizen science could best make an impact. We review examples of tools and methods that are appropriate for small water bodies, based on experience from a selection of freshwater citizen science projects, and the support that is needed for effective and sustained small water body projects across Europe. [ABSTRACT FROM AUTHOR]

Reservoir modeling consists of two key components: the reproduction of the historical performance and the prediction of the future reservoir performance. Industry-standard reservoir simulators must run fast on enormous and possibly unstructured grids while yet guaranteeing a reasonable representation of physical and chemical processes. However, computational demands limit simulators in capturing involved physical and geochemical mechanisms, especially when chemical reactions interfere with reservoir flow. This paper presents a mathematical workflow, implemented in IORSim, that makes it possible to add geochemical calculations to porous media flow simulators without access to the source code of the original host simulator. An industry-standard reservoir simulator calculates velocity fields of the fluid phases (e.g., water, oil, and gas), while IORSim calculates the transport and reaction of geochemical components. Depending on the simulation mode, the geochemical solver estimates updated relative and/or capillary pressure curves to modify the global fluid flow. As one of the key innovations of the coupling mechanism, IORSim uses a sorting algorithm to permute the grid cells along flow directions. Instead of solving an over-dimensionalized global matrix calling a Newton–Raphson solver, the geochemical software tool treats the species balance as a set of local nonlinear problems. Moreover, IORSim applies basis swapping and splay tree techniques to accelerate geochemical computations in complex full-field reservoir models. The presented work introduces the mathematical IORSim concept, verifies the chemical species advection, and demonstrates the IORSim computation efficiency. After validating the geochemical solver against reference software, IORSim is used to investigate the impact of seawater injection on the NCS Ekofisk reservoir chemistry. Article Highlights: The IORSim sorting algorithm decouples the nonlinear geochemical reaction calculations into recurring one-dimensional problems to assure numerical stability and computation efficiency. To the best of our knowledge, this work presents the mathematical concept, implementation, and application of topological sorting for the first time on (industry) field-scale problems. IORSim combines topological sorting with basis swapping and splay trees to significantly reduce computation times. Moreover, a high-speed forward simulation mode was developed to allow the post-advection of chemical components to visualize species distribution, water chemistry, and mineral interactions. If the geochemical reactions interfere with the fluid flow, the IORSim backward mode uses relative permeability curves to update the global fluid flow at each time step. We validate the implemented topological scheme on a reservoir grid, show the computation efficiency, and compare the impact of explicit, implicit, and grid refinement on numerical dispersion. The decoupled flow simulator and geochemical reaction calculations allow seamless integration of full-field reservoir models that contain complex geological structures, a large number of wells, and long production histories. The computation capabilities of IORSim are demonstrated by simulating and reproducing the impact of seawater injection in the southern segment of the giant Ekofisk field (more than 50 years of injection and production history). IORSim shows that seawater injection changed the Ekofisk mineralogy and impacted the produced water chemistry. In the investigated Ekofisk case, seawater promoted calcite dissolution and led to the precipitation of magnesite and anhydrite. Moreover, surface complexation modeling revealed that sulfate is adsorbed on the calcite surface. [ABSTRACT FROM AUTHOR]

Three quarters of the world's significant urban centers are located in coastal regions where clay minerals are prevalent. The microstructures and physico-mechanical properties of clay sediments are highly susceptible to alterations in pore water chemistry. The pore water chemistry in soil changes easily due to groundwater pollution, seawater erosion, degradation, etc. However, there are several inconsistencies in the literature on the change of physical and mechanical properties of clay soils caused by the change of pore water chemical properties, i.e., disparate experimental results were reported for the same soil property, or varying explanations were proposed for the identical experimental results. Currently, the research in this field mainly focuses on the macroscopic behavioral modifications while lacking the explanations of microscopic mechanism. Therefore, this paper presents a comprehensive review of researches conducted over the past four decades on the impact of pore water chemistry (including salt type, salinity, ion valence, pH) on soil properties such as the microstructure, settlement, Atterberg limits, shear strength, conductivity, unsaturated soil mechanics properties and thermal properties. The fundamental mechanisms underlying the varied experimental observations on clay sediments affected by salt and pH are systematically explored, and deficiencies in this field are identified. The observed dispersion in the literatures is attributed to the spatial variation and heterogeneity of soil compositions, different test methods, and insufficiency of the fundamental microscopic mechanisms of the observed soil behaviors, etc. Therefore, it is necessary to further explore the essential mechanisms of the test results in the future to establish a unified conclusion. [ABSTRACT FROM AUTHOR]

The aim of the BrineRIS project is to explore brines in RIS countries potential for critical metal extraction In the frame of this project the concentration of mineral brines in three geothermal wells located in the Beiuş Basin (northwestern Romania) was determined by analyzing the water from the wells. Until recently no reliable trace element data were available from Beiuş basin. Following the new analyses, the geothermal water extracted by TRANSGEX SA company from wells F-3001H, F-3003H, and F-3005H revealed exceptionally low concentrations of associated chemical compounds. The Liconcentration is only ~ 22 -- 32 µg/l. Zn, I, Rb and As present in similar concentrations, while other trace elements (e.g. Co, V, Ti) are below detection limit. The Sr (~ 540 -- 680 µg/l), Ba (~ 170 -- 200 µg/l) and B (~ 70 -- 100 µg/l) concentrations are slightly elevated, but still low. Therefore, the water in this "geothermal reservoir" can be classified as relatively potable, but it is not appropriate for critical metal extraction. In this paper, some documented concentrations from previous years have been compared to recent concentrations. In addition, the relationship between geology and water chemistry is emphasized in order to determine the reason for the absence of solutes that were expected to be found in this water. [ABSTRACT FROM AUTHOR]

This paper describes the existence of high salinity in an inland aquifer system of a limited extent located in the granitic terrain of south India. Salinity levels observed in 55 water samples collected pre- and post-monsoon are discussed. Limited repeat sampling during the two seasons shows no significant change in hydrochemistry, probably due to the prevailing drought conditions during the study period (2017–18). As per the salinity classification based on total dissolved solids (TDS), only one sample indicates freshwater while ~ 40% of the samples are slightly saline, and the remaining have moderate salinity. All the high TDS samples are located over a limited area, and most show the water type as Ca–Mg–Na–Cl–SO4. Hydrochemical data indicate a gradual increase in salinity from west to east. Mainly two distinct processes (1) reverse ion exchange and (2) evaporation are likely to have influenced the groundwater chemistry. Variation in water chemistry between granite and gneiss formations indicates the influence of geology on hydrochemistry. Insignificant changes in hydrochemistry for the limited repeat sampling during pre and post-monsoon periods show a meagre recharge due to failed monsoon. However, depleted stable isotope values with reference to high TDS suggest faster recharge conditions in the granitic region than in the gneissic region. Accumulation of high salinity in the groundwater is restricted to the granitic area. We postulate that the presence of Hornblende Biotite Gneiss along the southern parts of the granitic region may be acting as a boundary for accumulating saline groundwater in a limited area in this region. However, it needs confirmation through further detailed geological and geophysical studies. [ABSTRACT FROM AUTHOR]

This work aims to analyze the quality of groundwater in the riparian areas of the bauxitic plateaus of N'Dangara and Boundou Wandé in operation by the CBG (Compagnie des Bauxites de Guinée). The geology of the study area consists mainly of sedimentary formations of the Devonian faro, Neogene and Quaternary. Three water measurement and sampling campaigns on the two plateaus were carried out with determination of piezometric measurements and physic-chemical parameters. This study showed that the general flow direction of groundwater is dispersed. The flows at Boundou Wandé are from the center of the plateau to the north and that at N'Dangara is from the center to the south and southwest. It can be seen that the direction of groundwater flow reflects overall the relief of the deposit conditioned by its geomorphological framework. It emerges from the analysis of physical and chemical parameters that well water is consumable. However, the water from wells MW15, MW16, MW17, MW18 and MW21 with a low pH (4.84 to 5.13) may present a certain nuisance for its consumption and because it can be corrosive. Analysis of the Piper diagram showed two hydrogeochemical facies (calcium and magnesium bicarbonate facies and sodium and potassium carbonate facies). However, this study strongly suggests continuous monitoring of groundwater in and around the study area in order to meet the demand for water supply to communities without compromising the ability of future generations to meet water quality requirements. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This document is an editorial published in the journal Frontiers in Environmental Chemistry. It discusses the environmental chemistry of mercury, including its sources, pathways, transformations, and impact. Mercury is a global pollutant that can be transported through the atmosphere, ocean, and river watersheds. It is released into the environment from anthropogenic sources, such as gold mining and the use of coal and ores. The editorial highlights the complexity of mercury's behavior in different environments and the need for further research to understand its fate and effects. The document also mentions several papers published in the journal that examine various aspects of mercury's environmental chemistry. [Extracted from the article]

Because of anthropogenic activity and seawater intrusion, coastal aquifers worldwide frequently face a threat to their water supply due to salinization. This paper investigates the assessment of the groundwater quality in coastal aquifers of the Hauturivien aquifer in the Essaouira basin. In this study, 56 groundwater samples collected from the Hauturivian aquifer across four campaigns in 2017, 2018, 2019, and 2020 were subjected to multivariate analyses involving principal component analysis (PCA) and cluster analysis (CA) using SPSS software. Among the three main water types, the mixed Ca-Mg-Cl classification was predominant in the investigated aquifer. In addition to the natural processes (such as the water–rock interaction, ion exchange, dissolution/precipitation dynamics, and evaporation) that govern groundwater quality, current land use practices have increased salinization in this poorly drained semi-arid area. Based on assessments using Water Quality Index (WQI) and Irrigation Water Quality Index (IWQI), the water quality is suitable for human consumption, but its use for irrigation is limited to crops that can tolerate high salt levels. The stable isotopes (δ2H and δ18O) of groundwater demonstrated that local precipitation is the primary recharge source. Nonetheless, the evaporation process, influenced by various geological conditions, affects groundwater recharge, regardless of the topographical differences in the study area. [ABSTRACT FROM AUTHOR]

We present here, and make freely available, two long‐term datasets on the hydrology and hydrochemistry of two small catchments totally or partially covered by holm oak (Quercus ilex) forests. Data have been collected over four decades of research on the ecology of Mediterranean evergreen forests. The datasets contain data on water fluxes in precipitation and runoff, and on the ion concentrations and fluxes in precipitation, throughfall and streamwater. Among other applications, these data have been used to obtain catchment budgets of water and elements, to document decadal changes in atmospheric deposition and streamwater chemistry, to assess the role of Saharo‐Sahelian dust on forest nutrient cycling, and to model habitat suitability for an endangered amphibian under future climates. To encourage their further use by the scientific community, in this paper we summarize the data context and methods, and give a nutshell of obtained results. We provide the links to these datasets on the Zenodo platform. [ABSTRACT FROM AUTHOR]

The presence of persistent heavy fog in northern India during winter creates hazardous situations for transportation systems and disrupts the lives of about 400 million people. The meteorological factors responsible for its genesis and predictability are not yet completely understood in this region. Given its high potential for socioeconomic impact, there is a pressing need for extensive research that understands the inherently complex nature of the phenomena through field observations and modeling exercises. WiFEX is a first-of-its-kind multi-institutional initiative dealing with intensive ground-based measurement campaigns for developing a suitable fog forecasting capability under the aegis of the smart cities mission of India. Measuring campaigns were conducted during the 2015–20 winters at the Indira Gandhi International Airport, New Delhi, covering more than 90 dense fog events. The field experiments involved extensive suites of in situ instruments and gathered simultaneous observations of micrometeorological conditions, radiative fluxes, turbulence, droplet/aerosol microphysics, aerosol optical properties, fog water chemistry, and vertical thermodynamical structure to describe the environmental stability in which fog develops. An operational modeling framework, the WRF Model, was set up to provide fog predictions during the measurement campaign. These field observations helped to interpret the strengths and deficiencies in the numerical modeling framework. Four scientific objectives were pursued: (i) the life cycle of optically thin and thick fog, (ii) microphysical properties in the polluted boundary layer, (iii) fog water chemistry, gas–aerosol partitioning during the fog life cycle, and (iv) numerical prediction of fog. This paper presents an overview of WiFEX and a synthesis of selected observational and modeling analyses/findings related to the abovementioned scientific topics. [ABSTRACT FROM AUTHOR]

From March 30th to April 9th, 2021, an estimated 215 million gallons of wastewater from the Piney Point phosphogypsum stacks were released into Tampa Bay to avoid catastrophic failure of the holding ponds. Ammonium concentrations in the wastewater were measured in excess of 200 mg/L and it was estimated that ~205 tons of total nitrogen were exported to Lower Tampa Bay, exceeding typical annual nitrogen load estimates in a matter of days. In response to these events, a coordinated environmental monitoring effort consisting of multiple government, university, and private sector partners began to assess conditions of surface waters around Piney Point to understand conditions prior to, during, and after the wastewater release. These efforts included sampling of surface water chemistry, surveys of algal community response, assessments of wastewater contaminants, and biological surveys of seagrass, macroalgae, benthic, and nekton communities. This resulted in many disparate data sets coming from multiple sources, which required the use of robust synthesis methods for assessment of current conditions, comparisons with the decades of baseline data available in Tampa Bay, and development of forward-facing reporting products to convey results of field sampling in near real time. This paper describes the open-source tools that were used to synthesize the environmental monitoring data, the online dashboard that was developed to report the data, and how these products were used to inform management response to rapidly changing environmental conditions. The specific challenges in combining data, both from a technical and philosophical perspective, are also presented as lessons learned from the Piney Point experience to inform future event-based monitoring responses, both in Tampa Bay and elsewhere. [ABSTRACT FROM AUTHOR]

This paper aims to characterize and test the stability of sulfuric natural water (SNW) from Sebau East Lombok as a sulfidation agent for several dissolved metals (Mn, Cu, Pb and Fe). The parameters used for SNW characterization are temperature, pH, DO, BOD, COD, TSS, and TDS. The sample was divided into two categories, namely the sample with preservation treatment and the sample without preservation, to study the stability of SNW. The SNW stability was determined by observing the SNW parameters in both samples at a storage time of 5, 10, 15 and 20 days and reacting them with dissolved metals. The SNW with preservation had reduced sulphide levels from day 1 to day 20, ranging from 59.24 mg/L to 17.70 mg/L, whereas the sample without preservation had decreased sulphide concentration from 52.46 mg/L to 9.56 mg/L. Furthermore, the SNW with preservation has a relatively superior metal reduction ratio than the sample without preservation. The maximum value of the deposition ratio for Mn metal was obtained on the fifth day with 57.60%, 83.45% for Cu, and 91.87% for Pb. This trend is not applicable for Fe, whereas the highest reduction (87.23%) was obtained on the the15th day's storage. [ABSTRACT FROM AUTHOR]

Combining environmental isotope analysis with principal component analysis can be an effective method to discriminate the inflows and sources of contamination in mining-affected watersheds. This paper presents a field-scale study conducted at an acid mine drainage (AMD)-contaminated site adjacent to a pyrite mine in South China. Samples of surface water and groundwater were collected to investigate transport in the vadose zone using stable isotopes of oxygen (δ18O) and hydrogen (δD) as environmental tracers. Principal component analysis of hydrogeochemical data was used to identify the probable sources of heavy metals in the AMD. The heavy metal pollution index (HPI) was applied to evaluate the pollution status of heavy metals in the groundwater. The groundwater associated with the Datai reservoir was recharged by atmospheric precipitation and surface water. On the side near the AMD pond, the groundwater was significantly affected by the soluble metals produced by pyrite oxidation. The concentrations of some metals (Al, Mn, and Pb) in all of the samples exceed the desirable limits prescribed by the World Health Organization (Guidelines for drinking-water quality, 4th edn. World Health Organization, Geneva, 2011). Among them, the concentration of Al is more than 30,000 times higher than the desirable limits prescribed by the World Health Organization (2011), and the concentration of Mn is more than 3000 times higher. The HPI values based on these heavy metal concentrations were found to be 10–1000 times higher than the critical pollution index value of 100. These findings provide a reference and guidance for research on the migration and evolution of heavy metals in vadose zone water in AMD-contaminated areas. [ABSTRACT FROM AUTHOR]

Certain properties of an object only emerge when a sufficient number of those objects are present in a definite arrangement. For example, one or two water molecules cannot said to be in a liquid state, but a drop of water can be. This concept of emergence has been studied extensively, but only occasionally discussed explicitly in the context of chemistry. In this paper, we aim to show the fruitfulness of the concept of emergence for chemical inquiry by considering four case studies of emergent chemical properties, i. e., the liquidity and freezing of water, structural properties of crystals, thermodynamical phase transitions and quantum mechanical phenomena. We show that some of these properties emerge gradually, some at discrete points, and some should be taken to emerge only when the number of constituents tends to infinity. We argue that studying the way in which chemical properties emerge presents a useful avenue for research that promises greater insight into the nature of those properties. [ABSTRACT FROM AUTHOR]

Wet sour gas pipelines are subjected to corrosion deterioration mechanisms resulting from interactions between the fluid and piping material. Acid gases, condensation rates, water chemistry, and temperature are the key factors in determining the corrosivity of sour gas streams. This work investigated the corrosion risk of a new wet gas pipeline through laboratory experiments and corrosion modeling. The tests were carried out in Hastelloy autoclave rotating cage system used to generate controlled dynamic conditions inside the reactor to mimic the environment inside the pipeline. The results showed high bottom of the line corrosion (BLC) rate reaching 38.9 mpy (0.99 mm/year), while the measured pitting rate was 17 mpy (0.43 mm/year). The corrosion modeling results showed a severe BLC rate exceeding 200 mpy (5.08 mm/year). The observed high BLC was attributed to the absence of bicarbonate which led to a low pH of 3.9. At this pH, the formation of stable iron sulfide is unlikely. Top of the line corrosion (TLC) rate was observed to be moderate reaching up to 7.8 mpy (0.20 mm/year). This is mainly because of the low condensation rate and formation of a protective iron sulfide layer, which confirmed that iron sulfide scale characteristics are the main factor influencing the TLC rate in sour environments. The expected threshold concentration required of bicarbonate to show some reducing effect on the corrosion rate and pH based on historical data analysis and predictive modeling of real-field conditions is discussed in this work. The results and conclusion detail the path forward for the findings. [ABSTRACT FROM AUTHOR]

This paper presents two case studies involving early-in-life failures in water-tube boilers, with an emphasis on the metallurgical analysis utilized in determining the root causes. The two failures presented here demonstrate different failure modes boilers can suffer, even after operating for just a fraction of their design lives. The first case presents a large rupture in a baffle header that occurred two years after plant startup. The failure exhibited the classic signs of hydrogen damage, likely caused by deficient water chemistry control. The second case presents a classic case of moderate temperature, long-term overheat in a boiler that had been operational for three years. [ABSTRACT FROM AUTHOR]

Agricultural water accounts for more than 80% of the available water in arid areas. Agricultural activities have a great impact on surface water and groundwater. If the impact of agricultural activities on hydrochemistry is not prevented, the risk of water quality change in arid areas may be greatly intensified. Based on the hydrochemical data of the whole Shiyang River Basin from April 2014 to October 2019, this paper analyzes the impact of agricultural activities on hydrochemistry in the basin. The results show that (i) in the middle and lower reaches of farmland with high intensity of agricultural activities, the ion concentration of groundwater in summer and autumn is significantly higher than that in winter and spring due to the influence of irrigation; (ii) the runoff ion concentration in the backflow of the river reaches recharged by irrigation water is significantly higher than that of other reaches; (iii) due to strong evaporation, different types of reservoirs will lead to an overall increase in ion concentration, which is more obvious in plain reservoirs and river tail lakes. In addition, the reservoirs have a certain removal effect on nitrates. [ABSTRACT FROM AUTHOR]

Copyright of Mine Water & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Iraqi National Journal of Earth Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a new heavy oil development technology, hot water chemistry flooding has great potential in offshore heavy oil fields development. In this paper, the adaptability of hot water chemical flooding was studied based on the typical model of offshore heavy oil fields. The main controlling factors affecting the hot water chemical flooding were analyzed and evaluated by single factor analysis. The technical boundary was established for offshore heavy oil fields. In addition, the hot water chemical flooding scheme was designed by a case study of a well group oilfield D. The results indicate that crude oil viscosity and well spacing have great influences on hot water chemical flooding performance. Hot water chemical flooding is favorable when the crude oil viscosity is between 300 and 1000 mPa·s and well spacing is around 200~400 m. The hot water chemical flooding scheme of the target well group results in 40.2 × 10 4 tons of incremental oil, and 6.3% of recovery factor being enhanced, which shows strong evidence that hot water chemical flooding enables great oilfield development performance. [ABSTRACT FROM AUTHOR]

The development of water‐soluble hosts for the selective recognition of aromatic amino acids is highly desirable and may serve as a tool to facilitate drug discovery and enable fabrication of sensors for point‐of‐care monitoring in the context of phenylketonuria disease. This paper presents the synthesis and characterization of a water‐soluble molecular cleft which is demonstrated to selectively bind aromatic amino acid guests over other amino acids in aqueous medium, favoring ʟ‐Trp over ʟ‐Phe and ʟ‐Tyr by a factor of approximately five. Host/guest‐interaction forces were studied by 1H‐NMR titrations complemented by fluorescence titrations and isothermal titration calorimetry. The here presented results provide a starting point for future optimizations in our efforts to selectively identify and quantify individual aromatic amino acids in aqueous medium. [ABSTRACT FROM AUTHOR]

Karst groundwater is the main water supply source for human consumption and living, and it is important to study the karst groundwater resources to ensure people's water supply needs. In this study, the northern part of the Baiquan spring area in Hebei Province was taken as a research object. Based on the hydrogeochemical approach, the characteristics and mechanism of seasonal variations of karst groundwater in the area were studied, and the groundwater quality was evaluated. This paper mainly uses multivariate statistics, the Piper trilinear diagram, the ion ratio coefficient, and the water quality index (WQI) as water quality assessment methods. The sequence of the main ion abundance is as follows: Ca2+ > Mg2+ > Na+ > K+, > > Cl–, and the ion content showed a downward trend from the dry season to the wet season. The hydrochemical type in the dry season has changed compared with that in the wet season. The rate of carbonate rock dissolving in most of the study area waters in the wet season was higher than in the dry season. WQI calculation results show that most of the groundwater belongs to class II water quality, and the water quality in the wet season is better than that in the dry season. Studying different seasonal changes in groundwater chemistry can provide a reference for an in-depth understanding of karst groundwater chemistry characteristics and water resources protection in the spring area. [ABSTRACT FROM AUTHOR]

This paper describes the spatial and temporal variability of the hydrogeochemistry of shallow aquifer in the western Po Plains, located in Piedmont (northwestern Italy), using groundwater monitoring network data for the main chemical--physical parameters. Hydrochemical maps for the 2015-2020 period were created to identify the main natural and anthropogenic factors responsible for the remarkable spatial variability. Temporal variations in the 2000-2020 period were defined to show the existence of variabilities that were previously not investigated. The spatial and temporal elaborations show significant and various variabilities. The hydrochemical maps confirm the existence of several natural and anthropogenic factors, including the lithological compositions of aquifers, agricultural practices and pressure from urban centres. The temporal variations suggest different resilience capacities of the aquifers to the several impacting factors. The availability of this knowledge is crucial to create the basis for groundwater protection. [ABSTRACT FROM AUTHOR]

The coal-dominated energy structure in the Beijing–Tianjin–Hebei region has caused serious air pollution and contradicts the construction of a clean, low-carbon, safe and efficient energy system. Substituting geothermal energy for fossil energy such as coal can effectively alleviate this problem. Located in the hinterland of the Beijing-Tianjin-Hebei region, the Jizhong Depression is rich in geothermal resources and has great development potential, though the degree of current development and utilization is not high. Vigorously developing geothermal energy can not only effectively alleviate the air pollution problem in the Beijing–Tianjin–Hebei region, but also optimize the regional energy structure. Geothermal reservoir temperature determines the development and utilization value of geothermal resources, and accurate evaluation of the geothermal reservoir temperature of geothermal resources can provide a reliable basis for the subsequent development of geothermal resources in the Jizhong Depression. Aiming at the commonly used sandstone geothermal reservoir and carbonate geothermal reservoir in the Jizhong Depression, this paper collected 24 sandstone geothermal reservoir geothermal fluids and 14 carbonate geothermal reservoir geothermal fluids in the central-southern area of the Jizhong Depression and a water chemistry test was carried out. According to the test results of water chemistry, the temperature of the geothermal reservoir is estimated by using the cation geothermometer, the SiO2 geothermometer and the multi-mineral equilibrium method, and it is compared with the actual temperature measurement results of the boreholes. The results show that the direct use of a geothermal geothermometer for calculation will cause large errors. Through water–rock balance analysis, the use of a Na-K-Mg balance diagram, SiO2 and 1000/T relationship diagram and Na/K and 1000/T relationship diagram can determine whether the geothermal fluid is suitable for the geothermometer, which can effectively reduce the error. The chalcedony geothermometer in the central and southern part of the Jizhong Depression is the most suitable. The multi-mineral balance method, the Na-K geothermometer and the K-Mg geothermometer have also achieved good results, while the quartz and Na-K-Ca geothermometers are not suitable for the south-central Jizhong Depression area. [ABSTRACT FROM AUTHOR]

Freshwater wetlands located in dryland environments are characterised by high evapotranspiration rates and frequent periods of desiccation, which strongly influence the water chemistry and solute budgets of these systems. The transpiration of groundwater, especially by trees, is an important mechanism through which dryland wetlands can lose water. This process can lead to groundwater salinization and the precipitation of substantial quantities of minerals within the soil, the accumulation of which can have profound consequences for wetland structure and function. This paper aims to bring together current knowledge on the processes that result in solute accumulation and chemical sedimentation which assist in maintaining freshwater conditions in many seasonal dryland wetlands. Examples from central and southern Africa, Australia and South America are presented to illustrate the geomorphically diverse settings under which chemical sedimentation can occur, and the importance of these processes for the resilience and longevity of dryland wetlands. We show that the localised development of saline groundwater and subsurface precipitation of minerals within soils can play a key role in creating and maintaining the habitat diversity of dryland wetlands. Wetland vegetation localises the accumulation of deleterious constituents, thereby preventing widespread salinization and playa-lake formation, and thus ensuring that the bulk of the surface water remains fresh. Although such processes remain widely understudied, we suggest that chemical sedimentation could be a common phenomenon in many dryland wetlands and have important implications for the future management of these ecosystems. [ABSTRACT FROM AUTHOR]

Ponds are often identified by their small size and shallow depths, but the lack of a universal evidence-based definition hampers science and weakens legal protection. Here, we compile existing pond definitions, compare ecosystem metrics (e.g., metabolism, nutrient concentrations, and gas fluxes) among ponds, wetlands, and lakes, and propose an evidence-based pond definition. Compiled definitions often mentioned surface area and depth, but were largely qualitative and variable. Government legislation rarely defined ponds, despite commonly using the term. Ponds, as defined in published studies, varied in origin and hydroperiod and were often distinct from lakes and wetlands in water chemistry. We also compared how ecosystem metrics related to three variables often seen in waterbody definitions: waterbody size, maximum depth, and emergent vegetation cover. Most ecosystem metrics (e.g., water chemistry, gas fluxes, and metabolism) exhibited nonlinear relationships with these variables, with average threshold changes at 3.7 ± 1.8 ha (median: 1.5 ha) in surface area, 5.8 ± 2.5 m (median: 5.2 m) in depth, and 13.4 ± 6.3% (median: 8.2%) emergent vegetation cover. We use this evidence and prior definitions to define ponds as waterbodies that are small (< 5 ha), shallow (< 5 m), with < 30% emergent vegetation and we highlight areas for further study near these boundaries. This definition will inform the science, policy, and management of globally abundant and ecologically significant pond ecosystems. [ABSTRACT FROM AUTHOR]

Control and mitigating crevice corrosion demand a thorough understanding of the prevailing chemistry conditions inside the crevice. To match and predict the dynamics in chemistry conditions occurring inside a crevice appropriately, good crevice models necessitate extensive experimental data. This paper presents the accurate determination of the ionic species in the minute volume of crevice solution and redox potential measurements in fabricated simulated crevices of different dimensions/geometry in different stainless steel alloys. Crevice geometries fabricated from carbon steel (CS) 106 B and stainless steel (SS) 316 materials were exposed to varying water chemistry conditions in a static autoclave at high temperatures. The change in pH, conductivity, ionic concentrations, electrochemical potential and effectof corrosion inhibitors inside the crevice were monitored after exposure in an alkaline medium with and without chloride. Bulk solution pH showed a reduction in alkalinity, conductivity and enhancement in anion concentrations. About 58 times increase in Cl− was measured. [ABSTRACT FROM AUTHOR]

With rapid urbanization and industrial development, waste discharges in west central Tunisia have multiplied. The focus here is on the waste manifestation from the National Company of Cellulose and Alfa Paper (SNCPA), which has been considered as a serious pollutant affecting natural resources as surface and groundwaters, human health and hygiene in the Kasserine land of semi‐arid climate. In order to preserve the quality assurance of available groundwater and determine its suitability for domestic an agricultural needs, a hydrogeochemical analysis was carried out to 30 samples for water samples taken from various source points of the study area (2018). This study attempt to assess the hydrogeochemical characteristics and ionic concentration with respect to WHO (2017) and Tunisian (NT.09.14) standards in the El Arich aquifer, in association with multivariate‐statistical‐analysis. Also DRASTIC model index was integrated with geographical information system (GIS) tools for the evaluation of the aquifer vulnerability to pollution. Results highlighted that only 17.65% of the groundwater samples are suitable for consumption purposes based on TDS, EC, Na+, K+, SO42–, and F–. The modeling of equilibrium geochemical processes elucidated that the groundwater's along flow‐paths are mostly in the oversaturated condition with respect to carbonate minerals, but they are undersaturated with evaporatic minerals. Based on some pre‐specified criteria and the validation by the water quality risk indices for soil salinization, the final vulnerability map shows four classes of vulnerability: very high, high, moderate, and low, depending on the intrinsic properties. HCA and FA suggest that high mineralization were related to rock‐water interactions and anthropogenic impact from the effluents discharged by the SNCPA. This multidisciplinary analysis would provide an overview for decision making authorities to take necessary action for the sustainable management and future planning in groundwater resource. [ABSTRACT FROM AUTHOR]

The data set represents the Regional Meteoric Water Line (RMWL) for the Yucatan Peninsula (Mexico), a region with karstic aquifers but little knowledge of the isotopic composition of meteoric water. This data paper comprises the isotopic composition of meteoric water collected from November 2018 to November 2019 as monthly composite samples expressed as weighted monthly mean precipitation from 16 locations across the Yucatan Peninsula. The RMWL was δ2H = 7.803 δ18O + 12.075, with a slope and intercept suggesting precipitation from air that has undergone condensation, air masses with variable moisture or recycled moisture. The average δ18O is −2.57‰ (−12.23 to 1.2‰) and δ2H is −7.94‰ (−83.39 to 18.32‰). This data set was collected by the implementation of an isotopic monitoring network, gathering information useful as a tool for better understanding of the hydrology and hydrogeochemistry of karstic aquifers, and to develop proxies for paleohydrology, ecohydrology, climate change and paleoclimate studies in the Gulf of Mexico and the Great Caribbean Area. [ABSTRACT FROM AUTHOR]