Dilute Seawater Research Articles

Chemical enhanced oil recovery from shale‐rich tight carbonate reservoirs using 2‐butoxyethanol as a mutual solvent and diluted seawater

AbstractOil production from tight reservoirs due to their very low permeability and high capillary pressure requires complex operations and materials, so that hydraulic fracturing in these reservoirs is recommended before any chemical injection. This operation turns the reservoir into a fractured one that can produce more oil by activating the imbibition mechanism. The interfacial tension (IFT) of oil and water and reservoir rock wettability as key parameters of overproduction from this type of reservoir can affect this mechanism. In this study, the potential of 2‐butoxyethanol as a mutual solvent for enhanced oil recovery (EOR) was investigated with a focus on the oil production under imbibition in this type of reservoir through performing experiments and calculations of IFT, oil swelling, contact angle, and oil production. The analysis of the results shows that the mechanisms of IFT reduction, wettability alteration, and oil swelling, which all directly affect the oil production under imbibition, reached the desired values using 2‐butoxyethanol in the appropriate concentration along with the dilution of seawater. The lowest values for interfacial tension and contact angle at 0.03 M concentration of the solvent and 5000 ppm salinity at 90°C temperature were 1.315 mN/m and 71.57°, respectively. These values are much lower compared to the values obtained by similar additives, while solvents, unlike 2‐butoxyethanol, are effective in much higher volume ratios. The oil swelling increased by about 14% using 2‐butoxyethanol due to its mass transfer between water and oil phases through the interface. Finally, the oil recovery factors of 42% and 59% were achieved under one‐ and multi‐dimensional spontaneous imbibition (ODSI and MDSI), respectively.

Rare earth elements as indicators of post-Marinoan (∼635 Ma) paleoceanographic changes from the Amazon Craton

The extensive deglaciation linked to the Snowball Earth climate that elapsed in the terminal Neoproterozoic caused dramatic changes in ocean chemistry, exceptionally recorded in globally distributed cap carbonate successions. One of the most spectacular examples is the Puga cap carbonate (∼635 Ma), which is exposed in the Amazon Craton and associated with extensive sea level changes related to glacial-isostatic adjustment and local ice gravity, resulting in continuously mixed waters. This study meticulously evaluates complex post-Marinoan dynamics using a comprehensive multiproxy approach. The rare earth element + yttrium (REE+Y) patterns in the Puga cap carbonate do not accurately reflect the global ocean water composition; instead, they primarily fractionate in response to local expression of the post-Snowball Earth event, including alkalinity levels and freshwater mixing in the aftermath of the Marinoan glaciation. The flattened REE+Y pattern, accompanied by a positive Eu anomaly, may suggest the influence of continental weathering. Specifically, low Y/Ho ratios in the cap dolostone are consistent with seawater dilution due to meltwater influx (Y/Ho ∼ 29–32). Conversely, superchondritic Y/Ho ratios up to 71 in the basal cap dolostones suggest upwelling of hypersaline seawater in coastal areas. The shallow-water recurrence influenced by ice gravity resulted in continuous coastal uplift, forming isolated shelves and the deformation in diamicton, resulting in irregular substrate relief morphologies. This post-glaciation scenario was succeeded by significant landward shoreline migration concomitant with rapid recovery of primary productivity, with large microbial communities flourishing, inducing dolomite precipitation under restricted paleoenvironmental conditions on dolomitic platforms. The rapid rise in sea level led to the dilution of evaporative fluids, ultimately halting dolomicrite precipitation. Following the pos-tglacial transgression, the stratified waters gradually became more mixed, resulting in the termination of dolomitic platform deposition and coinciding with an increase in detrital components, as indicated by the increase of insoluble elements (e.g., REE, Zr, and Th), followed by abrupt replacement by CaCO3-oversaturated seas during the post-glacial transgression. These observations elucidate the interplay between post-glaciation and paleoceanographic dynamics during the Cryogenian-Ediacaran boundary.

Calcium carbonate is a liming product as good as calcium hydroxide in eutrophic CO2-rich waters

Currently, there is still much debate over the correct liming procedures to perform in shrimp ponds, concerning product, dosage, and timing, especially about the use of hydrated lime. The objective of this work was to determine the dissolution rates of Ca(OH)2 and CaCO3 in eutrophic CO2-rich waters with increasing Langelier saturation indexes (LSI), and discuss its importance to the rational liming of shrimp ponds. Three dilutions of seawater were prepared with increasing LSI values, namely −2.0, −1.0 and ≈ 0.0. The study was carried out in three consecutive phases of 5 weeks each. In the first, second and third phases, the flasks were filled with the LSI-2, LSI − 1 and LSI0 waters, respectively. In each phase, eight 2000-mL Erlenmeyer flasks received 1.0 g Ca(OH)2 p.a. and eight flasks received 1.0 g CaCO3 p.a. In four of the flasks that received Ca(OH)2 or CaCO3, one gram of a highly degradable organic matter (HDOM) was added. There were also four control flasks with no liming product but HDOM. The waters' temperature, pH, specific conductance, total alkalinity (TA), total hardness (TH), and the concentrations of Ca+2 and Mg+2 were monitored once a week. HDOM has moderated the increasing effect of Ca(OH)2 on the waters' pH. Regardless the water's LSI, and the liming product, the increase rate of TA was significantly greater in the HDOM-flasks. In all LSI-1 and LSI0 flasks, TH has decreased after the application of the liming products, despite the addition of HDOM. After one week, there was a marked Ca+2 drop in the Ca(OH)2 flasks with no HDOM. In all waters, the concentrations of Mg+2 have decreased significantly after the applications of Ca(OH)2 or CaCO3. Only the HDOM treatments have increased their initial LSI over time. The applications of Ca(OH)2 and CaCO3 in eutrophic CO2-rich waters have produced a total alkalinity higher than 100 mg L−1. Therefore, the anecdotal knowledge that hydrated lime is a superior liming product than agricultural limestone for shrimp ponds has not been supported by the present work.

Combined effect of magmatic fluid–seawater mixing and host rock alteration on the formation of gold-enriched massive sulfides in the Forecast vent field, southern Mariana Trough

Massive sulfides and sulfide-bearing breccia were collected from the Forecast vent field in the southern Mariana Trough. These samples exhibit varying degrees of hydrothermal alteration and/or mineralization, with the former type having significant enrichments in Au (up to 101 ppm). In this study, detailed analyses of mineralogy, geochemistry, S isotope, and fluid inclusion were conducted to understand the unusual Au-rich mineralization. Mineralogical investigations and geochemical analyses (LA–ICP–MS and EPMA) of dominant sulfide minerals indicate that electrums, the main phase of Au mineralization, are characterized by two different generations based on mineralogical relationships and fineness. Early-stage high fineness electrums (930–981 ‰) are associated with sphalerite under relatively high-temperature fluid conditions, whereas galena is main host mineral related to late-stage low fineness electrums (773–868 ‰). Sphalerite geothermometry (231–264 °C), the occurrence of colloform textured sulfides, and microthermometric characteristics of fluid inclusions (Th = 220–304 °C; Salinity = 1.4–6.6 wt% NaCl equivalent; a general trend of decreasing salinity with decreasing Th) indicate that significant decreases in H2S activity, attributed to seawater dilution and rapid precipitation of sulfide minerals, facilitated the efficient destabilization and deposition of Au transported as sulfide complexes from hydrothermal fluids. In particular, the lower 34S values (+0.2 ‰ to + 1.3 ‰) of sulfides compared to those of arc/back-arc lavas (δ34S = +5‰ to + 11 ‰), along with the prevalence of CO2 in the vapor phase of fluid inclusions, reflect that the significant contribution of magmatic volatile influx supplied most of the sulfur and metals (including Au) to the Forecast hydrothermal fluids. Additionally, the abundance of montmorillonite and varying proportions of sulfide and gangue minerals observed in hydrothermal samples suggest that the chemical buffering of fluids by associated substrates and/or sediments could be another significant factor in promoting Au-rich mineralization. Therefore we conclude that the combination of magmatic fluid–seawater mixing and host rock alteration plays an important role in the formation of Au-enriched massive sulfides in the Forecast vent field.

From flood to turbidity current: combined models to simulate continent to ocean sediment transport in the Var system, France

Turbidity currents are a form of gravity-driven flow that occurs in subaqueous environments. These currents contain a low volumetric percentage of particles but are very important in transporting them from coastal to deep-marine environments. In the Var sediment routing system, southeastern France, there is a sedimentary record of turbidity currents formed by submarine landslides and flooding of the Var River. In 2006, there was continuous monitoring of the marine section that recorded four turbidity currents. To explore the connectivity between the terrestrial source and marine basin we linked two reduced complexity models of sediment transport and landscape change. The aim of the paper is to combine two models, one dedicated to the prediction of river water and sediment run-off, and the second dedicated to the transport, erosion, and sedimentation by a turbidity current. The landscape evolution model CAESAR-Lisflood was used to model discharge and sediment yield. The behaviour of turbidity currents was modelled with the cellular automata model CATS. From calibration of the two models against observations of discharge and suspended sediment in the Var River system, we find that in 2006, two rainfall events would have led to hyperpycnal turbidity currents. These two events match well with two of the four-recorded events. Focusing on the largest event we find that the source pulse of sediment from the terrestrial environment is short-lived, less than half a day, but contains a significant quantity of fine particles. The event transferred on the order of 105 m3 of suspended sediment from source to sink. This study demonstrates that hyperpycnal turbidity currents can be generated with concentrations as low as 2-6 kg/m3 at the Var River mouth far below the theoretical 40 kg/m3 threshold, suggesting active convective sedimentation in the surface plume and sea-water dilution at the flooding river mouth. A substantial amount of sediment (35% of the input volume) is directly transferred towards the deepest part of the system during a short-living hyperpycnal turbidity current. However, a considerable (65%) part remains in the surface as a hypopycnal plume feeding the hemipelagic sedimentation.

Climatic-hydrologic influence on redox condition in the Cryogenian interglacial Nanhua Basin: Insights from the Datangpo Formation in the northwestern Yangtze Block, South China

Tracking climatic and oceanic redox changes throughout the Neoproterozoic Cryogenian is crucial to a better understanding of the coevolution of life and environment in geological history. However, the processes and driven mechanisms of redox evolution in the Cryogenian interglacial ocean still remain uncertain. Here, we present a combined study of geochemical proxies, such as paleoclimatic proxies (CIA and Zr/Al) and paleosalinity proxies (B/Ga and Sr/Ba), from the interglacial Datangpo Formation in the shallow-water Zuojiawan section exposed in the northwestern Yangtze Block, to constrain climatic and hydrologic changes on redox conditions. Our data indicate that two apparently climatic cycles from warming to cooling occurred during the deposition of the Datangpo Formation, supplementing the monotonous climatic warming in previous research during the Cryogenian interglaciation. The low B/Ga and Sr/Ba ratios throughout Datangpo Formation suggest a continuous freshwater condition, which is in contrast to a transition of marine condition to brackish condition in relatively deep-water sections. Compiled salinity reconstructions at different paleo-depths imply the salinity gradient in the Nanhua Basin with a density stratification like modern Baltic Sea, at least during the early Cryogenian interglacial period. We find that the climate-driven local riverine freshwater input may be a significant driver for maintaining long-term freshwater condition in the Zuojiawan section. Accompanied by synchronously climatic warming, the progressive desalinization with declining B/Ga and Sr/Ba ratios in the middle to upper deposition of the Datangpo Formation are probably attributed to the persistent freshwater input to a nearshore shallow-water paleogeographic setting. Combined the improving oceanic oxygenation backdrop with the elevating seawater sulfate concentration in the Nanhua Basin in this period, we conclude that the continuous dilution of seawater in the restrict (semi-) Nanhua Basin could attenuate the density stratification and enhance the vertical mixing of watermass, favoring the ventilation of deepwater and penetration of sulfate. This contribution provides a new insight for the study of salinity changes on redox conditions in the Yangtze Block during the Cryogenian interglacial period, and provides new data for supporting a systematic understanding of the evolutional mechanism of oceanic redox state.

Insights on physiological, antioxidant and flowering response to salinity stress of two candidate ornamental species: the native coastal geophytes Pancratium maritimum L. and Eryngium maritimum L

Increasing seawater influence in coastal areas is an ongoing environmental issue. Gardening is a widespread activity mainly in touristic areas such as the Mediterranean coasts. However, the use of exotic species well adapted to salinity encompasses the risk of invasive species introduction. This study aimed to evaluate salinity tolerance of native geophytes, Pancratium maritimum L. and Eryngium maritimum L., to assess their use as ornamental species in salt affected coastal areas. Experiments were conducted using cultivated plants for flowering response and physiological and enzymatic antioxidant response. Six treatments were applied for two months, exposing plants to seawater (SW) dilutions (Tap-Water, 6.25%SW, 12.5%SW, 25%SW, 50%SW and 100%SW). Taxa decreased inflorescence production being this effect more architectonical in E. maritimum and affecting all inflorescence integrity in P. maritimum. Flowering time was strongly delayed and reduced in P. maritimum, while E. maritimum showed smaller effects among treatments. Physiological and biochemical response showed at moderate salinity levels (1/4SW) variation concomitant with late stress response and senescence in P. maritimum, with decreased water use efficiency, NPQ values, and enzymatic activity, and increased malondialdehyde (MDA) levels. In contrast, E. maritimum showed early stress response with steady gas exchange response, increasing NPQ values and catalase (CAT) and superoxide dimutase (SOD) activity, and decreasing MDA levels with salinity. Glutathione enzymes showed limited participation in both species. The results of this study suggest that neither species can be classified as halophytes, but they exhibit tolerance to low and moderate salinity levels, making them suitable for ornamental use.

Design, fabrication, and performance assessment for green hydrogen production unit

Creating and building an integrated system that consists of a storage tank, an electrolysis cell with many electrolyzer types, and a green hydrogen generator that produces clean, sustainable gas using solar photovoltaic (PV) energy and renewable energy sources. Three different electrolyzer modules with six, eleven, and twenty-one plates each were created locally and meant to be utilized in the production of green hydrogen. The hydrogen storage system's design was also created. It is clear that the maximum value of hydrogen production is recorded in the following ordered: KOH (5.5 L/min) > NaOH (1.2 L/min) > NaCl (0.7 L/min) > MgSO4 (0.4 L/min). Also, sea water was used as electrolyte solution with different dilution 5, 10, 15, and 20% using a natural sea water sample collected from the Mediterranean Sea. It is found that 15% sea water dilution reaches the maximum value of H2 production (3.4 L/min). Using distilled water and tap water, respectively, the volume of generated H2 gas reached its maximum value of 8 L/min and 6.5 L/min at 0.4 mols of KOH. It was observed that with increased time durations (0–90 min), enhance the rate of hydrogen production to be reaches 8.2 and 11.5 L/min when using 0.05 and 0.1 mols KOH, respectively. This approach reduces environmental effect and operational costs, providing a sustainable solution to the water and energy problems.

Enhanced oil recovery and mitigating challenges in sandstone oil reservoirs employing EDTA chelating agent/ seawater flooding

While low salinity water (LSW) holds promise for improving oil recovery, its implementation is comparatively costly due to the substantial volumes of fresh water required to dilute seawater (SW). Additionally, concerns arise regarding potential issues related to LSW, including fines migration in sandstone reservoirs and scale formation in carbonate reservoirs. Chelating agents can be introduced into undiluted SW to bind with metal ions, thereby lowering its salinity. This approach mimics the behavior of LSW injection while overcoming associated challenges. This study involves measuring oil/injected solution interfacial tension (IFT), evaluating sandstone surface wettability alteration, along with conducting different sand pack flooding scenarios using Ethylenediaminetetraacetic acid (EDTA) chelating agent. The aim was to comprehend the EDTA oil recovery mechanisms and determine the optimal concentration of EDTA that minimizes chemical consumption while maximizing oil recovery. The findings indicated that incorporating 5 wt% EDTA into SW significantly reduced IFT from 29.52 mN/m to 4.75 mN/m, making the oil nearly miscible in the solution. Moreover, wettability tests confirmed that a minimum EDTA concentration of 5 wt% is required to shift wettability from oil-wet to strongly water-wet conditions. Sand pack flooding experiments, on the other hand, further demonstrated that this optimized fluid system can potentially recover an additional 16.1 % of oil following SW flooding. Finally, inductively coupled plasma (ICP) analysis revealed a notable increase in metal ion concentration during EDTA flooding, indicating enhanced leaching of metals from the sandstone surface and improved wettability characteristics.

Determining the optimization of seawater concentrate discharge of coastal desalination plants into the marine environment, based on numerical modeling.

In recent years, due to a decrement in water quality and scarcity, desalination systems have gained popularity for desalination purposes. Synchronously, with the development of this system, particularly, in concern with the littoral regions, seawater concentrate disposal consisting of various pollutants was taken into consideration. In this research, two desalination plants near each other were selected and four scenarios have been foreseen, for the discharge of seawater concentrate and the desalination intake, which are taken under study in the Ramin-Chabahar region, based on dual-dimensional hydrodynamic simulation, comprising of diffusion and release, by utilizing the MIKE 21 Software. Due to the proximity of the two desalination plants, to reduce the costs of piping in the sea, the location of discharge and intake were considered common. On the grounds pertaining to the modeling results, the discharge of seawater concentrates, at a distance of 300m (5m of depth) from the coast and the intake point, at a distance of 800m, in elongation, has had the minimum environmental impact; as well as having no undesirable effect on the water quality of the intake, in addition to being cost-effective, from the economic viewpoint. To dilute seawater concentrate to a standardized level, it is appropriate to discharge through a diffuser with 10 nozzles, which are spaced out at 3.25m from each other, being positioned linearly on one side, at an angle of 60 degrees. With the optimal selection of intake and discharge points of seawater concentrate in marine desalination plants, in addition to increasing the quality of treated water and reducing adverse environmental effects, construction and operation costs are also reduced.

Experimental investigation of carbamide-assisted smart water flooding for enhancing heavy oil recovery from carbonate reservoirs

This study explores the impact of carbamide at different concentrations on smart water flooding into carbonate reservoirs. The aim is to find out how the presence of carbamide can influence the mechanisms of smart water flooding at rock/brine and oil/brine interfaces. The results revealed that interfacial tension (IFT) reduces as the carbamide concentration increases in the brine. Indeed, the carbamide decomposes at elevated temperatures, and in-situ surface active agents are formed at the oil/brine interface, reducing IFT values. Further, while the dilution of seawater (SW) is unable to change the oil-wet wettability, the carbamide can make the carbonate surface more water-wet by elevating its concentration. Additionally, the corresponding mechanisms of this wettability alteration would be the formation of in-situ surface active agents, electrostatic interactions, and hydrogen bond formation at the rock/brine interface. Among K+, Mg2+, and SO42−, adjusting the concentration of sulfate ions in SW leads to greater IFT reduction in the presence of carbamide. In addition, the contact angle is further reduced as K+ concentration is doubled in the solution; however, this reduction is not significant as compared to Mg2+ and SO42−. Also, ten-times diluted seawater (10dsw) produced more micro-dispersions in the oil phase. Nevertheless, the presence of carbamide in 10dws had a negative impact on the micro-dispersion formation, which is one of the driving mechanisms of smart water flooding. At a lower carbamide concentration (1000 ppm), more carboxylic acids and ketones were observed in the brines due to the partitioning and dissociation of naphthenic acids. On the contrary, as carbamide concentration increased to 10000 ppm, amounts of carboxylic acids declined due to the production of in-situ surface active agents at the oil/brine interface. Bottle test experiments indicated that water-in-oil emulsions were generated in the presence of carbamide. The mean water droplet size grew as carbamide concentration rose to 25000 ppm; nonetheless, further increase in the carbamide concentration resulted in mean droplet size reduction. Calcite-coated micromodel flooding illustrated that oil recovery of 21.6, 24, and 27.2 % was found at carbamide concentrations of 1000, 10000, and 100000 ppm. Furthermore, a three-time increase in SO42− concentration at 10000 ppm of carbamide offered a better performance in boosting oil recovery than tuning K+ and Mg2+ concentrations in carbamide/SW solutions. The findings of this study underscore the promising prospects of leveraging carbamide to enhance the efficacy of smart water solutions in carbonate reservoirs, particularly regarding IFT modification, wettability alteration, and oil recovery enhancement.

Response to Seawater Exposure During the Flowering Stage of Two Dune-Building Grasses: Calamagrostis arenaria (L.) Roth and Thinopyrum junceum (L.) Á.Löve

Human disturbance and seawater intrusion have unpredictable effects on coastal species. Dune systems are crucial coastal habitats because they provide natural front protection against seawater influence. Adult plant stands in dunes are important since they maintain dune structure. This study evaluated salinity stress responses in adult plants of two key dune-building grasses differing in salt tolerance: Thinopyrum junceum (tolerant) and Calamagrostis arenaria (less tolerant). Cultivated plants were exposed to various seawater (SW) dilutions (Tap-Water, 6.25%, 12.5%, 25%, 50%, and 100%) and gas exchange measurements and oxidative stress biomarkers were determined after two months of treatment. Stress conditions were maintained until flowering to assess effects on the reproductive effort. The reproductive response showed high plasticity at various inflorescence stages in T. junceum, minimizing abortion processes. C. arenaria showed lower plasticity and higher abortion rates. Physiological traits responded similarly to salinity in both species, with greater effect on Fv/Fm decrease and non-photochemical quenching increase for T. junceum. Biochemical patterns of response were also similar, with increasing enzymatic activities at 25% SW treatment, mainly for glutathione reductase and peroxidase (GSH and GPx), and stress damage occurring at 50% and 100% SW treatments for increased malonaldehyde (MDA) levels. These findings provide insight into the salinity tolerance mechanisms of dune-building grasses. Higher salinity tolerance is suggested for T. junceum based on better reproductive effort. Higher juvenile tolerance, faster growth, and plant cycle adjustments are indicated as key traits for higher salinity tolerance of T. junceum in contrast to C. arenaria.

α-Tocopherol mediates alleviation of salt stress effects in Glycine max through up-regulation of the antioxidant defense system and secondary metabolites

α-Tocopherol (αT) has been reported to overcome the adverse effects of many environmental stresses, including salinity. A pot experiment was performed to investigate the response of salt-stressed soybean plants to the foliar application using 50, 100, or 200 mg αT L–1. The stress was applied by irrigation with three different dilutions of seawater [e.g., EC = 0.23 (tap water as a control), 3.13, or 6.25 dS m–1]. The gradual increase in salinity level gradually increased net carbon dioxide (CO2) assimilation, relative growth rate, antioxidant capacity, secondary metabolites (total phenolic compounds, flavonoids, and tannins), enzymatic activities, and DNA fragmentation due to the gradual increase in lipid peroxidation as a result of an increase in hydrogen peroxide (H2O2). On the contrary, yield components (number and weight of seeds plant–1) and photosynthetic pigment (total chlorophyll and carotenoids) contents gradually decreased with increasing salinity level. However, leaf treatment with αT, especially at 200 mg αT L‒1, preserved the highest antioxidant activities (antioxidant capacity, secondary metabolites, and enzymes), which were associated with the preservation of soybean yield and leaf pigments. These positive results occurred due to the reduction in lipid peroxidation as a result of a significant decrease in the level of H2O2. Therefore, our results recommend the use of 200 mg αT L–1 as a commercial formula for soybeans grown under saline irrigation of no more than 6.25 dS m–1.

Клінічне значення деблокади носового дихання в дітей грудного і раннього віку на тлі гострих респіраторних вірусних інфекцій: переваги ізотонічного розчину морської води

Acute respiratory viral infections (ARVI) are an urgent problem in young children, which is due to their significant prevalence, they have a constant tendency to increase and occupy the first places in the structure of infectious diseases. Damage to the mucous membranes of the upper respiratory tract in children with ARVI lead to numerous problems that require adequate replacement of the main functions of the child’s body, which determined the relevance of our study. Purpose - to analyze the effectiveness of the use of isotonic dilution of sea water (Pshyk Mini medicine) for irrigation therapy in nasal congestion in infants and young children caused by acute respiratory infections. Materials and methods. A comprehensive examination of 100 infants and young children with influenza and other ARVI was conducted in the infectious diseases department of the Chernivtsi Regional Children’s Clinical Hospital. The children were randomly divided into 2 clinical groups: the Group I included 55 children (average age - 1.09±0.3 years, the proportion of boys - 58.1%), who, as part of complex standard therapy, received nasal irrigation using 2-3 drops of Pshyk mini medicine in each nostril 3 times/day. The Group II included 45 patients (average age - 1.15±0.2 years (p>0.05), the proportion of boys - 59.1% (p>0.05)), in whom isotonic sodium chloride solution was used for the purpose of the nasal sanitation. Results. The conducted studies showed that starting from the 3-4th day of hospitalization, a statistically significant decrease in catarrhal manifestations and the severity of nasal obstruction was noted in patients of the Group I who received Pshyk Mini in complex treatment. In particular, in relation to the results of the Group II, in the children of the Group I, on the 4th day of inpatient treatment, the chances of reducing the severity of catarrhal manifestations (estimated ≤2 points) increased: the absolute risk increase - 53.0%, the relative risk increase - 67.9% (95% CI: 57.8-76.9) with the minimum number of patients who need to be treated to obtain a positive result - 1.5. We also established that compared to the representatives of the Group II, children of the Group I had almost a 4-fold increase in the chances of restoring tolerance to feeding (estimation of feeding difficulties ≤2 points): attributive risk - 30.5%, relative risk - 1.6 (95% CI: 0.6-4.8), odds ratio - 3.9 (95% CI: 1.2-12.3). Conclusions. For the purpose of unblocking of nasal breathing in infants and children of early age at the background of acute respiratory viral infections, the use of an isotonic solution of sea water (Pshyk Mini medicine) has a number of significant advantages compared to the use of an isotonic solution of sodium chloride for this purpose. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Osmoregulatory physiology of the angel wing bivalve Cyrtopleura costata (Pholadidae), an estuarine intertidal burrowing mollusc

ABSTRACT Cyrtopleura costata is a pholadid bivalve that inhabits tidal flats inside burrows c. 40 cm deep, and its visceral mass outgrows its shell significantly. Thus, unlike other bivalves, it cannot isolate its soft tissues from the external environment through complete valve closure. One can thus hypothesize that this bivalve would be inevitably more exposed and susceptible to the tidal changes in salinity. No information regarding its osmoregulatory physiology has been found in the literature. We thus investigated how its fluids would respond to seawater dilution and seawater concentration, and how its tissues would be able to keep their moisture content. Individuals of C. costata were acclimated to 30‰ and then independently exposed stepwise (1 h for each 5‰ change) to 25, 20, 15 and 10‰ or to 35, 40, 45 and 50‰. Isolated tissue slices obtained from control animals (30‰) of siphon, mantle and muscle were exposed in vitro to salines corresponding to salinities of 10, 30 and 50‰. Cyrtopleura costata responded as a typical euryhaline osmoconformer between 25 and 40‰, with haemolymph and mantle cavity water being isosmotic to the external medium. However, some ‘buffering’ of haemolymph osmolality was displayed in the most extreme salinities, 10–20‰ and 45–50‰. This could result from muscle contraction and other cellular responses, reducing ‘apparent permeability’ and diffusive fluxes; the muscle was the tissue with the highest capacity to maintain constant hydration despite significant osmotic challenge. Both in vivo and in vitro experiments indicated a higher tolerance of salinity increases than decreases. Thus, if global and local changes in climate and precipitation rates result in more frequent seawater dilution in its habitat, the area occupied by its realized niche may be reduced.

Adaptation mechanism of Phan Rang sheep to salinity in drinking water under tropical conditions.

The aims of this study were to determine adaptation mechanism of sheep to salinity in drinking water. A group of 10 male sheep were used in a 6-week of experiment, with 1week for pre-treatment period (Week 1), 4weeks for during treatment period (Week 2 to Week 5), and 1week for posttreatment period (Week 6). During the pre- and posttreatment periods, sheep consumed with fresh water. However, during treatment period, they were given with diluted seawater (DSW) at concentrations of 0.5%, 1.0%, 1.5%, and 2% for Weeks 2, 3, 4, and 5, respectively. Animal was offered 300 g concentrate and corn stover silage for ab libitum. Dry matter intake decreased as DSW increased, whereas sheep drinking DSW showed an increase in water intake and urine volume (p < 0.05). Body weight change decreased in 2% DSW. Sheep consuming 2% DSW exhibited higher plasma electrolyte levels compared to other groups. But plasma levels of AST, ALT, and creatinine were unaffected by DSW (p > 0.05). The elevated levels and excretions of urinary electrolytes were found in DSW groups (p < 0.05). Water balance was unaffected by DSW, except during the recovery period. It concluded that adapted sheep can consume DSW up to 1.5% without harmful effects.

Determine the Essential Micronutrients Intake by Vibrio cholerae in Association with Algae in Different Waters

Phosphate, nitrite, nitrate are the micronutrients for Vibrio cholerae and algal growth. Current study intended to determine the utilization of these micronutrients by V. cholerae in association with algae in four different water (Distilled water, River water, Aritificial sea water and BOD dilution water). Amount of these micronutrients were estimated from stock water, control water and algal water by developing standard curve method. Among these four stock water, orthophosphate was the highest in amount (10.44µg/L) in BOD dilution stock water and significant positive changes (0.06 µg/L) from stock found in the algal water in River water microcosm. In stock sample , the highest amount of nitrite was found in both River and BOD dilution water (6.486µg/L) and the most significant increase ( 388.014µg/L) from stock was found in the control water of BOD dilution water. River stock water contained the maximum nitrate (1865.204µg/L) among four water types and the highest increase was found in the control water of River. In brief, the amount of phosphate, nitrite and nitrate varied with the types of water. Most cases amount of nitrite- nitrate increased by the decay of V. cholerae which used by algae for their growth and overloaded algae did not use phosphate from the surrounding water.

Ameliorating effect of nanoparticles and seeds’ heat pre-treatment on soybean plants exposed to sea water salinity

Impairing plant growth and reducing crop production, salinity is considered as major problem in modern agriculture. The current study aimed to investigate the role of seeds' heat pretreatment at 45 °C as well as application of two different nanoparticles nanosilica (N1) and nanoselenium (N2) in reducing salinity stress in three genotypes of Egyptian commercial soybeans (Glycine max L.). Two levels of salt stress using diluted sea water (1/12 and 1/6) were tested either alone or in combination with protective treatments. Obtained results revealed that salinity caused a significant reduction in all tested physiological parameters such as germination rate and membrane stability in soybean plants. A significant reduction in mitotic index and arrest in metaphase were recorded under both tested levels of salinity. It was also revealed that chromosomal abnormalities in soybean plants were positively correlated with the applied salinity concentrations. The fragmentation effect of salinity on the nuclear DNA was investigated and confirmed using Comet assay analysis. Seeds heat pre-treatment (45 °C) and both types of nanoparticles' treatments yielded positive effects on both the salt-stressed and unstressed plants. Quantitative real-time reverse transcription PCR (qRT-PCR) analysis for salt stress responsive marker genes revealed that most studied genes (CAT, APX, DHN2, CAB3, GMPIPL6 and GMSALT3) responded favorably to protective treatments. The modulation in gene expression pattern was associated with improving growth vigor and salinity tolerance in soybean plants. Our results suggest that seeds’ heat pretreatment and nanoparticle applications support the recovery against oxidative stresses and represent a promising strategy for alleviating salt stress in soybean genotypes.

SARS-CoV-2 RNA in Wastewater and Bivalve Mollusk Samples of Campania, Southern Italy.

SARS-CoV-2 can be detected in the feces of infected people, consequently in wastewater, and in bivalve mollusks, that are able to accumulate viruses due to their ability to filter large amounts of water. This study aimed to monitor SARS-CoV-2 RNA presence in 168 raw wastewater samples collected from six wastewater treatment plants (WWTPs) and 57 mollusk samples obtained from eight harvesting sites in Campania, Italy. The monitoring period spanned from October 2021 to April 2022, and the results were compared and correlated with the epidemiological situation. In sewage, the ORF1b region of SARS-CoV-2 was detected using RT-qPCR, while in mollusks, three targets-RdRp, ORF1b, and E-were identified via RT-dPCR. Results showed a 92.3% rate of positive wastewater samples with increased genomic copies (g.c.)/(day*inhabitant) in December-January and March-April 2022. In the entire observation period, 54.4% of mollusks tested positive for at least one SARS-CoV-2 target, and the rate of positive samples showed a trend similar to that of the wastewater samples. The lower SARS-CoV-2 positivity rate in bivalve mollusks compared to sewages is a direct consequence of the seawater dilution effect. Our data confirm that both sample types can be used as sentinels to detect SARS-CoV-2 in the environment and suggest their potential use in obtaining complementary information on SARS-CoV-2.

Nitrogen accumulation and attenuation in the Ganges-Brahmaputra-Meghna river system: An evaluation with multiple stable isotopes and microbiota

We examined dissolved inorganic nitrogen (DIN) accumulation and attenuation in the lower stream and estuary of the Ganges-Brahmaputra-Meghna River system. In the lower stream of Ganges, Meghna and Brahmaputra rivers, nitrate (NO3−) was the dominant component in the DIN pool apart from the site near an industrial center. Concentrations of NO3− displayed minor differences between surface and bottom water, accounting for >90 % of the riverine DIN pool. Sources of NO3− were likely to be municipal wastewater and fertilizer based on signals of 15N-NO3− and 18O-NO3−. In the Meghna River, ammonium concentration in river water increased due to sewage discharge from local industrial centers. In the estuary, likely due to the high-abundance nitrifiers, nitrification rates overwhelmed removal rates and led to NO3− accumulation. Towards coastal ocean, DIN concentrations decreased due to seawater dilution and biological assimilation, indicating a tight linkage between the riverine input and ecological stability in the receiving water.