Bicarbonate Water Research Articles

Assessment of Antigout, Antioxidant and Production Performance Augmenting Activity of Piper betle L. in Gout Induced Broiler Chicken

Background: The gout is commonly reported in birds and causes severe economic losses to the farmers. Hence to prevent the gout occurrence P.betle L. herb was selected and its antigout potential was studied in comparison with Allopurinol.Methods: The biological experiment was conducted with 120 broiler chicks and was divided into 5 treatment groups of 8 birds each with triplicate study for six weeks. The groups were control (T1), gout control (T2), Allopurinol (T3), P.betle L. - 10 g/kg (T4) and P.betle L. - 12.5 g/kg of feed (T5). The gout was induced using toxic dose of sodium bicarbonate in water (20 g/litre). The clinical signs and production performance were recorded and gross and histopathology studies were conducted. Serum biochemical parameters viz., uric acid and creatinine were periodically estimated (day 10, 15, 18 and 42 of trial) and anti-oxidant and xanthine oxidase enzyme activity were measured.Result: The production performances and the antioxidant activity were improved in P.betle L. groups and even better than Allopurinol. Also progressive reduction of uric acid and equivalent suppression of xanthine oxidase activity as that of Allopurinol were observed. Hence P.betle L. herb can be used effectively in the prevention of gout in birds.

Beneficial Effects of Natural Mineral Waters on Intestinal Inflammation and the Mucosa-Associated Microbiota.

Natural mineral water (NMWs) intake has been traditionally used in the treatment of various gastrointestinal diseases. We investigated the effect of two French NMWs, one a calcium and magnesium sulphate, sodium chloride, carbonic, and ferruginous water (NMW1), the other a mainly bicarbonate water (NMW2) on the prevention of intestinal inflammation. Intestinal epithelial cells stimulated with heat inactivated Escherichia coli or H2O2 were treated with NMWs to evaluate the anti-inflammatory effects. Moderate colitis was induced by 1% dextran sulfate sodium (DSS) in Balbc/J mice drinking NMW1, NWW2, or control water. General signs and histological features of colitis, fecal lipocalin-2 and pro-inflammatory KC cytokine levels, global mucosa-associated microbiota, were analyzed. We demonstrated that both NMW1 and NMW2 exhibited anti-inflammatory effects using intestinal cells. In induced-colitis mice, NMW1 was effective in dampening intestinal inflammation, with significant reductions in disease activity scores, fecal lipocalin-2 levels, pro-inflammatory KC cytokine release, and intestinal epithelial lesion sizes. Moreover, NMW1 was sufficient to prevent alterations in the mucosa-associated microbiota. These observations, through mechanisms involving modulation of the mucosa-associated microbiota, emphasize the need of investigation of the potential clinical efficiency of such NMWs to contribute, in human beings, to a state of low inflammation in inflammatory bowel disease.

Measurements of Bicarbonate in Water Containing Ocean-Level Sulfate Using a Simple Multi-Pass Optical Raman System

The concentration of dissolved inorganic carbon in the oceans at depths of a few meters to thousands of meters is a critical parameter for understanding global warming. The concentration is both pH dependent and depth dependent. Current analysis that employs pH meters must account for several other parameters, such as salinity, temperature, pressure, and the dissolved carbon’s form, carbon dioxide, bicarbonate, or carbonate. Recently, Raman spectroscopy has been used to measure these forms directly in water at ~1000 ppm, which is unfortunately insufficient for typical ocean concentrations, such as ~115 ppm bicarbonate near the surface. Here, we employed a simple multi-pass optical system, a flat mirror to reflect the laser back through the sample, and a concave mirror opposite the entrance slit that effectively doubled the laser power and the collected Raman photons, respectively. This multi-pass optical Raman system with a 1.5 W, 532 nm laser was used to measure 30 ppm bicarbonate in water that contained 2650 ppm sulfate to simulate ocean water, a bicarbonate concentration well below that near the ocean surface. Furthermore, spectral analysis employed the bicarbonate C=O symmetric stretch at 1360 cm−1 instead of the C–OH stretch at 1015 cm−1 to avoid the intense, overlapping sulfate SO4 symmetric stretch at 985 cm−1. The calculated standard deviation of ~5 ppm for the described approach suggests that accurate measurement of bicarbonate in situ is possible, which has been, heretofore, either calculated based on pH or measured in a lab.

Etermination of Geothermal Reservoir Zone of Sorik Marapi, Mandailing Natal, North Sumatra

The Sorik Marapi Geothermal Power (SMGP) Field is located in Mandailing Natal (350 km to the southeast from Medan), North Sumatra. This study needed alteration mineral data validation with fluid geochemical characteristics from surface manifestations, and production wells were determined the geothermal reservoir zone. Therefore geothermometer and geoindicator calculations were used. Laboratory tests were carried out on 38 surface manifestations and 11 cutting samples of exploration well. Manifestations in this area include hot springs, fumaroles, and steaming ground. Alteration minerals found in the study area are anhydrite, epidote, calcite,chlorite, muscovite, pyrophyllite, and zeolite. The alteration zone is located in the zeolite zone, the epidote zone,and the anhydrite-sericite zone. Geochemical manifestations of surface and production wells containing chloride water, sulfate water, sulfate-chloride water, and bicarbonate water. The estimated reservoir temperature of SH-01 well shows temperatures ranging from 240–280˚C, SH-02 well shows temperatures of 249.89–302.92˚C, SH-03 well show temperatures of 231.09–280˚C. The mineral geothermometer calculation, which is correlated with the geochemical fluid geothermometer, shows valid results. This is evident from the estimated reservoir temperatures of the two geothermometers.

Bamboo culm vertical lever flattening mechanism with sodium bicarbonate softening process

Some constructions require flattening bamboo culms to be used for constructing flat surfaces. With such need for flattened bamboo culms, the aim of this research is to develop a cost-effective and novel way of flattening bamboo culms for the species, Schizostachyum lumampao or buho, by integrating a softening process using sodium bicarbonate water solution and application of steam, then be pressed by a pressing mechanism using counter-bending technique to eliminate spring back effect of the bamboo culm. An open vessel was filled with sodium bicarbonate and water solution tested at concentrations between 15% and 26% by volume and then heated by 1.5 kW immersion heater. Pressure vessel partially filled with water and a 3-kW immersion heater were used to generate steam for the bamboo culm to maintain its flexibility as it is pressed. The bamboo culms reached a mean degree of flatness of 0.91. Thinner “Buho” (bamboo culm) submerged at around 20% of NaHCO3 concentration was successfully flattened within an average flattening time of ten (10) minutes, similar with thicker bamboo culm but submerged at concentration greater than 20% of NaHCO3. The machine had been incorporated with batch-type process and showed an efficiency of 90.75%.

Arsenic Adsorption on Modified Clay Minerals in Contaminated Soil and Water: Impact of pH and Competitive Anions

AbstractThis study evaluates the arsenic adsorption behavior of Fe‐exchanged smectite and phosphate‐bound kaolinite, in soil, tap water and double distilled water in the presence of competing anions such as silicate, phosphate, and sulfate, and at variable pH values. The maximum amounts of As adsorbed in soil are 620.6 and 607.6 µg g–1 at pH 5 by Fe‐exchanged smectite and phosphate‐bound kaolinite, respectively. The pH‐modified Freundlich equation fits well (R2 > 0.96) to the adsorption data, distinguishing the effect of pH on adsorption. The coefficients of pH‐value are 0.04 and 0.05 for phosphate‐bound kaolinite and Fe‐exchanged smectite, suggesting that low pH is suitable for the adsorption. The As adsorption is decreased in tap water at low pH compared to the soil due to the presence of iron (Fe2+/3+), sulfate, and bicarbonate in tap water. Among the competing anions in distilled water, phosphate is the most interfering anion for As adsorption. The competition coefficients of As‐phosphate binary adsorption derived from the Sheindorf equation are 3.93 and 0.56 for Fe‐exchanged smectite and phosphate‐bound kaolinite at pH 5. The Fe‐exchanged smectite can be used more effectively than phosphate‐bound kaolinite for As remediation in systems having low pH (pH ≈5) and high phosphate concentration.

Adsorption of hexavalent chromium from water using manganese-aluminum coated sand: Kinetics, equilibrium, effect of pH and ionic strength

Removal of hexavalent chromium [Cr(VI)] from water was evaluated using a low-cost coated sand adsorbent for potential application in a flow-through filter system using permeable adsorption media. Manganese-aluminum coated sand (MACS) was investigated as a hybrid metal oxide based adsorbent due to the potential efficacy of manganese oxide and aluminum oxide for adsorption of Cr(VI) from water. Adsorbent characterization was performed using XRD, SEM/EDX, XPS and BET. Adsorption experiments were performed to determine adsorption capacity and kinetics. The effect of pH, common co-existing ions found in natural water, and the recyclability of adsorbent were investigated. Adsorbent characterization showed that the MACS sorbent contained aluminum oxide, manganese (III) oxide and manganese (IV) oxide. Adsorption followed the Langmuir and Freundlich adsorption equations, indicating favorable adsorption of Cr(VI) onto the MACS sorbent, while results from the Dubinin–Radushkevich equation were suggestive of physical adsorption of Cr(VI). Cr(VI) adsorption onto the MACS sorbent followed pseudo-second order kinetics. The adsorbent was effective in removing Cr(VI) over a broad pH range from 3 to 9.5, while surface charge analysis confirmed the adsorption of Cr(VI) onto the acidic surface of the MACS sorbent with a pHPZC of 9.72. The presence of co-existing ions bicarbonate, sulfate and phosphate in water resulted in a decrease in Cr(VI) uptake in the following order: phosphate > bicarbonate > sulfate. The presence of calcium resulted in a slight increase in Cr(VI) uptake. The MACS sorbent is a recyclable sorbent for adsorption and removal of Cr(VI) from water within 30 minutes of contact time.

ОЦЕНКА МАССОПЕРЕНОСА ГЛАВНЫХ ИОНОВ, ЖЕЛЕЗА И МЕТАНА ПРИ РАЗГРУЗКЕ ПОДЗЕМНЫХ ВОД ЧЕТВЕРТИЧНОГО ВОДОНОСНОГО КОМПЛЕКСА В АЗОВСКОЕ МОРЕ

The specificity of the chemical composition of underground waters of the Quaternary aquifer complex of the Azov sea catchment basin, which dominates the flow volume, is considered. Using deterministic models, the volumes of runoff of the main ions, common iron, and methane are calculated. The predominant ones are sulphate, chloride-sulphate or sulphate-chloride, less often bicarbonate and chloride waters, usually of a sodium or calcium cationic composition. The average annual volume of underground water flow in the Quaternary complex is about 0.024 km3/year (66,300 m3/day). The average annual value of underground ion runoff is ~387,000 t/year, with 47.2% of this value being accounted for by sulfate ions. The average annual underground runoff of total iron and methane is ~0.968 t/year and ~0.037 t/year, respectively. The dominant contribution (over 98%) to the volume of underground runoff of the main ions, common iron and methane is made by their runoff from the Northern sections of the sea catchment basin, which is mainly due to the distribution of the module of underground water flow.

Mechanisms of the Formation of Sodium Bicarbonate Groundwaters in the Southeast of West Siberia

The research data are presented on the chemical and isotope composition of sodium bicarbonate groundwaters in the southeast of West Siberia. It is shown that the studied waters occur ubiquitously within Mesozoic–Cenozoic sedimentary deposits at a depth roughly from 50–300 m to 1.0–2.3 km. Various geochemical characteristics and conditions of occurrence made it possible to distinguish five types of waters: (I) fresh, (II) brackish, (III) high-alkaline low-saline, (IV) coal-deposit saline, and (V) carbonated waters. Types I and II are characterized by regional occurrence and a quite typical chemical composition. Types III–V have specific compositions and occur locally throughout the region. The genesis of all types of bicarbonate waters was determined as infiltration based on isotope data (δ18O, δD, and δ13С). Type IV is characterized by a positive “oxygen shift” and the carbon source is biogenic, except for type V. Calculations of equilibrium in the water-host minerals system showed that all bicarbonate waters were nonequilibrium for a number of primary aluminosilicate minerals and equilibrium for a wide variety of carbonates and clays. It was found that the amount of water-equilibrium minerals increased from type I to type IV with increasing water total dissolved solids (TDS) and pH values. The studies identified the governing characteristics of the formation of secondary minerals and hence of bicarbonate waters, including the main (pH value, Si, Ca, HCO3, and Al) and additional parameters of the medium (organic matter and gases). The same mechanism for all types of bicarbonate waters was determined: dissolution of water-nonequilibrium aluminosilicate minerals of sedimentary deposits and simultaneous precipitation of carbonates. The diversity of manifestations of bicarbonate waters is related to different interaction times in the water–rock system (types I and II), even during the bicarbonate stage, as well as additional overprinting of environmental features, i.e., the occurrence of supplementary sources of CO2 and organic matter for types IV and V, respectively, or their absence for type III. The presented formation schemes for different types of bicarbonate waters were also confirmed by the data of 18O and 13С isotope studies.

Geochemical assessment of groundwater in the Kuiseb River basin in Namibia

Groundwater is one of the most valuable natural resources in the world, and, a limited resource, particularly for Namibia. For this reason, this resource should be protected and monitored on a regular basis for sustainability. One of Sustainable Development Goals (SDGs) aims to ensure availability and sustainable management of water and sanitation for all with specific emphasis on data and good governance. Therefore, this study was conducted in the Kuiseb Basin, Namibia to assess the physical and chemical quality of groundwater, chemical water type and chemical characteristics of sediment to determine its suitability for human consumption. Water and sediments samples from 20 sampling sites (boreholes) were analysed for physical and chemical characteristics and the following mean values were obtained for temperature (26.66 °C), electrical conductivity (396.85 mS/m), pH (7.26), total dissolved solid (494.45 mg/L) and dissolved oxygen (7.46 mg/L). Physico-chemical results suggest that the Kuiseb Basin is predominantly a calcium bicarbonate water type (Ca (HCO3)2) and most of the physico-chemical parameters tested fell within the permissible limits for drinking water set by the World Health Organisation (WHO). Analysis of the major ion chemistry (Mg2+ > + Ca2+ > + Na+ > + K+ and HCO3− > CO3− > SO4 2− > Cl−) indicated the dominance of rock-water interaction and the influence of anthropogenic activities as the main processes controlling groundwater chemistry in the area. It is recommended that the Basin, as a heavily used and sensitive environment, requires basin-wide river management.

A Detailed Assessment of Groundwater Quality in the Kabul Basin, Afghanistan, and Suitability for Future Development

Kabul is one of the most populated cities in Afghanistan and providing resources to support this population in an arid climate presents a serious environmental challenge. The current study evaluated the quality of local Kabul Basin groundwater to determine its suitability water for drinking and irrigation purposes now and into the future. This aim was aided through groundwater parameter assessment as well as determination of Water Quality Index (WQI) developed from 15 observation points near the city. The results of our physicochemical analysis illustrate that groundwater in the majority of areas of the Kabul Basin is not generally suitable for human consumption, and in some cases the concentrations of many contaminants are higher than accepted health standards or water quality benchmarks. The aquifer underlies an arid landscape, and because of this 85% of the samples tested are very hard while just over 13% are classified as hard. Groundwater in the Kabul Basin is typically high in calcium and magnesium and overall classified as a calcium bicarbonate water type. Overall, more than 60% of the analyzed samples had concentrations higher than the World Health Organization (WHO) standard of total dissolved solids (TDS), 10% in total hardness (TH), about 30% in turbidity and more than 90% in magnesium. The results show that based on WQI, without treatment, roughly 5% of groundwater in the studied area is unsuitable for human consumption, while 13.3% is very poor and 40% is poor quality water. Approximately 40% of the assessed groundwater has good quality and could be used as drinking water for future development. Groundwater in some areas shows evidence of pollution and high dissolved solids content, rendering these sources unsuitable for either drinking or irrigation purposes.

Hydrogeochemistry and chemical weathering in a periglacial environment of Maritime Antarctica

Recent pedological investigation indicated that the presence of sulfides and additions of seabird guano in Maritime Antarctica accelerates the weathering process, but chemical weathering remains little studied, underestimated and underdiagnosed in cold environments. The present work evaluates characteristics of soils and hydrogeochemical processes in Barton Peninsula, a typical periglacial environment of Maritime Antarctica. Four pedons were selected, described, sampled and classified according to the U.S. Soil Taxonomy. Soil morphological, physical and chemical properties were analyzed. Fifty eight surface water samples were collected and analyzed. Samples were filtered, acidified and analyzed (Al, Ca, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, S, Si and Zn) by ICP-OES after the appropriate treatments. We identified four different water groups: i) calcium and magnesium bicarbonate waters on non-sulfated substrates; ii) acidic sodium sulfate or magnesium calcium sulfate waters in sulfate substrates; iii) neutral alkaline waters on phosphatic substrates; iv) sodium hyperchloride alkaline waters in coastal marine areas. The hydrogeochemical composition can be predicted by lithology, landform and bird nesting density. Higher concentrations of metals in running waters indicate the process of sulfide oxidation. Our results show that seabirds activity promotes a sea-land bio-transfer of nutrients resulting in ornitheutrophication, identified by positive hydrogeochemical anomaly (high nutrients) in soils and waters. Sulfated and ornithogenic soils present deeper weathering (sulfurization and phosphatization processes), which cannot be underestimated. The assessment of hydrogeochemical background is a suitable tool for preservation of terrestrial ecosystems in this part of Antarctica.

Development and validation of an LC-MS/MS method for the quantitative analysis of milciclib in human and mouse plasma, mouse tissue homogenates and tissue culture medium

Milciclib is a promising cyclin-dependent kinase inhibitor currently in phase II clinical trials to treat several types of cancer. The first bioanalytical method for the quantitative analysis of milciclib in several biomatrices using liquid chromatography-tandem mass spectrometry is described here. This method was fully validated in human plasma according to FDA and EMA guidelines, and partially validated in mouse plasma, homogenates of mouse brain, kidney, liver, small intestine, spleen, and tissue culture medium. Palbociclib, an analog compound, was used as internal standard. A simple and fast sample pre-treatment by protein precipitation with acetonitrile was used, leading to efficient extraction of the analyte with recoveries between 95–100%. Chromatographic separation was achieved with a C18 analytical column and a gradient elution using 10 mM ammonium bicarbonate in water and 10 mM ammonium bicarbonate in water-methanol (1:9, v/v). This assay was selective, accurate, precise and linear in the concentration range of 1−1000 ng/mL. Moreover, samples above the upper limit of quantification can be integrally diluted up to 10-fold prior to analysis. The use of human plasma as a surrogate matrix to quantify milciclib in tissue culture medium and mouse matrices resulted in acceptable accuracy and precision, however tissue culture medium samples required a dilution with human plasma prior the pre-treatment. All performance parameters of the method complied with the acceptance criteria recommended by the guidelines, except for the carry-over, which was slightly above (22.9% of the lower limit of quantification) the recommended percentage (20%). Therefore, additional measures were taken to assure data integrity. Stability of milciclib in all matrices was evaluated, and in some matrices the analyte was unstable under the tested conditions. It is therefore recommended to keep these samples as briefly as possible at room temperature during the pre-treatment, and to store them at –70 °C to avoid analyte degradation. This method was successfully applied to support preclinical pharmacokinetic studies of milciclib.

Application of isotope techniques to enhance the conceptual hydrogeological model and to assess groundwater sustainability in the Pampean plain in Córdoba, Argentina

ABSTRACT The objective of this work is to enhance the conceptual hydrogeological model in the Río Cuarto River basin by using isotope and hydrochemical techniques. The precipitation pattern, as reflected in the average values of δ 2H and δ 18O in stations located in the plains and in the mountains, showed an isotope depletion from the East to the West, attributed to continental and altitude effects. Groundwater quality is mainly the result of two controlling factors: lithology and flow distances from recharge. The aquifers show fresh calcium/sodium bicarbonate water in the upper and medium basin (coarse fluvial sediments) which evolve to sodium sulphate and chloride waters in the low basin (mainly loess and fine alluvial sediments). The confined aquifer systems in the lower basin (C and D systems) averaged more negative stable isotope values, indicating that groundwater recharged during colder climatic conditions (Pleistocene period). Groundwater dating with 14C confirmed that groundwater ages range from modern to 45,000 years BP showing that as the water flows towards deeper layers and farther from the mountainous recharge area, groundwater age increases. The confined aquifers can potentially be exploited in order to partly cover different water needs but they should be managed in a sustainable way.

Identification Distribution of Hot Spring in Cisarua Using Magnetic Method

Lampung is one of the provinces which have hot spring resource. One of the unique hot springs in Lampung is Cisarua hot spring. Its location is far from volcanic which makes researcher curious with the system of hot spring from Cisarua. Based on the geology map, the location of hot spring is in Lampung Panjang Fault. The aim of this research is to know about type, zone and distribution of hot spring. The method used in this research is magnetic method with combined geochemistry. From geochemical analysis, the type of hot spring in Cisarua is bicarbonate water. It correlates with outflow and shallow zone. Based on 3D modelling of low magnetic anomaly, distribution of hot water is in Center and Southeast research area. Hot water is interpreted by low anomaly.

Major, trace and rare earth elements geochemistry of geothermal waters from the Rehai high-temperature geothermal field in Tengchong of China

Major and trace elements geochemistry of high-temperature geothermal waters are important for understanding the subsurface transport and transfer of mass during groundwater circulation. The major constituents and trace elements, including rare earth elements, are discussed to reveal the source of elements and the hydrogeochemical processes occurring in the geothermal waters in the Rehai high-temperature geothermal field in Southwest China. Neutral-alkaline bicarbonate geothermal waters and acid sulfate waters are observed in Rehai due to different genesises. The bicarbonate waters contain higher concentrations of Na, K, Cl, HCO3, Li, Be, F, Sc, Ti, V, Cr, Ga, Rb, Nb, Sb, Cs, W, Tl, Zr and Si and less SO4 than the sulfate waters. The hydrogeochemical analyses show that the recharge of magmatic fluids, mixing with cold water and water-rock interaction affect the concentration of the elements. The geothermal waters and host rock REE chondrite-normalized patterns and the Eu anomalies are inherited from the host rock signature. Negative Ce anomalies may result from oxidative scavenging process of Ce and/or adsorbtion by the precipitation of Fe oxyhydroxides. T, TDS, pH and Fe/Mn minerals all affect the REE concentrations of geothermal waters. Calculations of REE speciation show that in the alkaline waters, Ln(CO3)2- is the major speciation. In the neutral waters, Ln(CO3)2- and LnCO3+ are the main speciation. In the weak acid waters, LnCO3+ is the main speciation and LnSO4+ are the major speciation in the strong acid water.

Amorphous High-Surface-Area Aluminum Hydroxide-Bicarbonates for Highly Efficient Methyl Orange Removal from Water.

Amorphous high-surface-area aluminum hydroxide-bicarbonates were synthesized starting from AlCl3, base, and bicarbonate in water. Composites with a chemical formulas of [Al13O4(μ-OH)24(H2O)6.5(OH)5.5](HCO3)1.5 (I-NaOH) and [Al13O4(μ-OH)24(H2O)6(OH)6](HCO3) (I-NH3) were obtained by the use of NaOH/NaHCO3 and NH3/NH4HCO3 as base/bicarbonate, respectively. The surface area of the composites was highly dependent on the pH level of the synthetic solution, and composites with high surface areas (ca. 200 m2 g-1) were obtained around pH 7-8. Pore-size distributions determined from the N2 adsorption isotherms showed that I-NH3 and I-NaOH possess mainly large (pore radius rp > 3 nm) and small (rp < 3 nm) pores, respectively, despite similar surface areas. While SEM images showed that both I-NH3 and I-NaOH were aggregates of nanoparticles, the particles were more fused in I-NaOH, which is in line with the existence of small pores and the use of a stronger base (NaOH), which would facilitate the dehydration condensation reaction. The composites were applied as adsorbents to remove methyl orange (MO) from water. The time course of MO adsorption was readily fitted with a pseudo-second-order model, and over 90% MO removal was attained within 10 min with I-NH3, while I-NaOH showed much less MO removal (26%). The MO adsorption isotherm of I-NH3 was reproduced with a Langmuir model with an adsorption capacity of 154 mg g-1. Notably, the aluminum hydroxide-bicarbonates could not absorb methylene blue, which is a cationic dye, while anions (MO and PO43-) were readily absorbed. Solid-state 27Al MAS NMR spectra showed that the concentration of 5-coordinated aluminum species, which may serve as guest binding sites, was higher for I-NH3. These results show that electrostatic interaction between anionic MO and coordinatively unsaturated 5-coordinated cationic aluminum species and the large external surface area of I-NH3 contribute to the highly efficient MO adsorption.

Groundwater Hydrogeochemistry in Bukit Raya and Tenayan Raya, Pekanbaru, Indonesia

Pekanbaru is growing rapidly and one of the largest in industry and commercial sector on Sumatera Island. Hydrogeological mapping and major elements in groundwater samples from protected wells were used to determine hydrochemical facies in Bukit Raya and Tenayan Raya sub-districts in Pekanbaru. A total of 14 groundwater samples were collected in May 2017. A Piper Trilinear diagram was employed to evaluate the hydrogeochemical evolution of groundwater. Results show that water table varies from 7.02 to 46.67 m in depth and flow toward the middle of research area which is Sail River. Based on groundwater table, the relationship between groundwater and river water was effluent. Hydrochemical facies of groundwater in the study area are dominated by sodium chloride, calcium chloride, and calcium bicarbonate water type. Dominance of Na+ elements in facies is from the dissolution of Feldspar or Pyroxene in sand, and the Ca2+ element in facies is from the dissolution of Feldspar and Plagioclase in sand. The presence of Cl− element in facies is from salt crystals in rainwater, and the HCO3 − element in facies has contact with air and is dominated by rainwater. Lithology conditions in the study area are generally weathered so that the influence of rocks on rainwater is quite high.

Ion Pairing and Multiple Ion Binding in Calcium Carbonate Solutions Based on a Polarizable AMOEBA Force Field and Ab Initio Molecular Dynamics.

The speciation of calcium carbonate in water is important to the geochemistry of the world's oceans and has ignited significant debate regarding the mechanism by which nucleation occurs. Here, it is vital to be able to quantify the thermodynamics of ion pairing versus higher order association processes in order to distinguish between possible pathways. Given that it is experimentally challenging to quantify such species, here we determine the thermodynamics for ion pairing and multiple binding of calcium carbonate species using bias-enhanced molecular dynamics. In order to examine the uncertainties underlying these results, we derived a new polarizable force field for both calcium carbonate and bicarbonate in water based on the AMOEBA model to compare against our earlier rigid ion model, both of which are further benchmarked against ab initio molecular dynamics for the ion pair. Both force fields consistently indicate that the association of calcium carbonate ion pairs to form larger species is stable, though with an equilibrium constant that is lower than for ion pairing itself.

INTERCONECTIVIDADE DE AQUÍFEROS E OS EFEITOS DA DRENAGEM ÁCIDA DE MINA NA QUALIDADE DAS ÁGUAS DA BACIA CARBONÍFERA DE SANTA CATARINA (SC)

A atividade carbonífera no sul de Santa Catarina se desenvolve há mais de um século e a falta de gerenciamento ambiental nos empreendimentos mineiros causou significativas alterações de qualidade nos recursos hídricos da Bacia Hidrográfica do Araranguá. Além da alteração na qualidade das águas, ocorreram fenômenos de colapso e abatimento de minas subterrâneas que ocasionaram fraturamento das camadas sobrejacentes, e permitiram a ampliação dos processos de circulação dos sistemas aquíferos com corpos hídricos superficiais. Com objetivo de melhorar o entendimento destes processos, foram analisadas amostras das águas de 9 poços do Sistema Aquífero Rio Bonito, 4 poços do Sistema Aquífero de Leques Aluviais e 6 amostras de águas superficiais das mesmas microbacias onde estão instalados os poços. As análises hidroquímicas indicam uma predominância de águas bicarbonatadas cálcicas e sódicas, que quando em contato com a drenagem ácida de mina são transformadas em águas sulfatadas. A composição isotópica em termos de isótopos de oxigênio e de hidrogênio das amostras evidencia semelhança com a composição isotópica das águas meteóricas. Este fato contribui com a hipótese da forte interação da água subterrânea com as águas freáticas e superficiais, que ocorre devido à tectônica rúptil que afeta as litologias gonduânicas, e é intensificada pela presença das minas de subsolo.