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Sea purslane (Sesuvium portulacastrum) was cultivated for two 90-day sequences at two spacings, and with various soil amendments, to evaluate its potential to arrest the increase in soil salinity and sodicity associated with irrigation using paper- and pulp-mill effluent. Its phytodesalination capacity (PDC) with respect to Na ranged from 162 to 226 kg/ha in the first sequence and 167 to 250 kg/ha in the second sequence; the PDC is reliable even under drought stress. Addition of amendments, in particular pressmud compost, increased the average Na+ uptake by 38%, leading to the highest PDC of 250 kg/ha for a single crop sequence. [ABSTRACT FROM AUTHOR]

Paper and pulp mills use a huge quantity of water in the manufacturing process and release a substantial quantity of salts in the effluent. The use of industrial effluents for irrigating crops due to the nutrient content in arid zones is under practice. The long-term use of paper and pulp mill effluent as a source of irrigation accumulates salts in the soil surface and rhizospheric zone. In this study, halophytes, namely Sesuvium portulacastrum, Salicornia brachiata, and Suaeda maritima were evaluated for their phytodesalination potential in paper and pulp mill effluent irrigated soil. Among these Sesuvium portulacastrum recorded the highest dry matter production (8.21 g pot-1), and the sodium accumulation was 6.7% greater than S. brachiata on 120th day. Furthermore, the soil EC was also 7.7 % lower in pots cultivated with S. portulacastrum than pots cultivated with S. brachiata. Hence, Sesuvium portulacastrum could effectively be used to phytodesalinate saline soils and ensure the sustainable cultivation of crops using paper and pulp mill effluent. [ABSTRACT FROM AUTHOR]

Key Message: Integrated omics analyses outline the cellular and metabolic events of hemp plants in response to salt stress and highlight several photosynthesis and energy metabolism related pathways as key regulatory points. Soil salinity affects many physiological processes of plants and leads to crop yield losses worldwide. For hemp, a crop that is valued for multiple aspects, such as its medical compounds, fibre, and seed, a comprehensive understanding of its salt stress responses is a prerequisite for resistance breeding and tailoring its agronomic performance to suit certain industrial applications. Here, we first observed the phenotype of salt-stressed hemp plants and found that under NaCl treatment, hemp plants displayed pronounced growth defects, as indicated by the significantly reduced average height, number of leaves, and chlorophyll content. Next, we conducted comparative proteomics and metabolomics to dissect the complex salt-stress response mechanisms. A total of 314 proteins and 649 metabolites were identified to be differentially behaving upon NaCl treatment. Functional classification and enrichment analysis unravelled that many differential proteins were proteases associated with photosynthesis. Through metabolic pathway enrichment, several energy-related pathways were found to be altered, such as the biosynthesis and degradation of branched-chain amino acids, and our network analysis showed that many ribosomal proteins were involved in these metabolic adaptations. Taken together, for hemp plants, influences on chloroplast function probably represent a major toxic effect of salinity, and modulating several energy-producing pathways possibly through translational regulation is presumably a key protective mechanism against the negative impacts. Our data and analyses provide insights into our understanding of hemp's stress biology and may lay a foundation for future functional genomics studies., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Environmental contamination by chromium represents a serious public health problem. Therefore, it is crucial to develop and optimize remediation technologies to reduce its concentration in the environment. The aims of this study were to evaluate the uptake of chromium by live and complete microbial mats in experimental mesocosms under different pH and salinity conditions to understand how these factors affect the microphytobenthic community and, consequently, how chromium removal process is influenced. Microbial mats from the estuarine environment were exposed to 15 mg Cr/L under different pH (2, 4, and 8) and salinity (2, 15, and 33) conditions. Salinity, redox potential, and pH were measured throughout the trial in solutions and in microbial mats, while total Cr determinations were performed at the end of the assay. The results demonstrated that the removal efficiency of Cr by microbial mats was significantly improved in solutions at pH 2, remaining unaffected by variations in salinity. Notably, both cyanobacteria and diatoms showed remarkable resistance to Cr exposure under all conditions tested, highlighting their exceptional adaptability. Microbial mats have proved to be effective filters for reducing the concentration of chromium in aqueous solutions with varying pH and salinity levels., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Coastal aquifers with high hydraulic conductivities on the order of 10 -2  m s -1 have unconventional salinity distributions with the presence of non-fresh groundwater at the water table over a wide swath near the coast. This study aims to unravel the mechanisms underlying the phenomenon via numerical simulations for variably saturated, density-driven flow and solute transport in porous media. The simulation results indicate that the existence of non-fresh groundwater at the water table is attributed to the upward mass flux in the saturated zone near the coast, which transports solute from deeper groundwater toward the water table. With high hydraulic conductivity, the upward mass flux becomes prominent at shallower elevations because of the high Darcy flux and the shallow saline groundwater. The upward mass flux has two main drivers, upward advection by the upward flow component and transverse dispersion by the seaward flow component. The advective mass flux dominates over the transverse dispersion in the deep part of the saturated zone where only groundwater with sea water salinity exists. In contrast, the transverse dispersion becomes more pronounced than the upward advection in the shallow saturated zone just beneath the water table and in the unsaturated zone immediately above the water table. Our findings help interpret the unconventional salinity distributions observed and elucidate the unique dynamics of groundwater flow and solute transport in highly permeable coastal aquifers., (© 2023 The Authors. Groundwater published by Wiley Periodicals LLC on behalf of National Ground Water Association.)

The degradation of freshwater systems by salt pollution is a threat to global freshwater resources. Salinization is commonly identified by increased specific conductance (conductivity), a proxy for salt concentrations. However, conductivity fails to account for the diversity of salts entering freshwaters and the potential implications this has on microbial communities and functions. We tested 4 types of salt pollution-MgCl 2 , MgSO 4 , NaCl, and Na 2 SO 4 -on bacterial taxonomic and functional α-, β-diversity of communities originating from streams in two distinct localities (Nebraska [NE] and Ohio [OH], USA). Community responses depended on the site of origin, with NE and OH exhibiting more pronounced decreases in community diversity in response to Na 2 SO 4 and MgCl 2 than other salt amendments. A closer examination of taxonomic and functional diversity metrics suggests that core features of communities are more resistant to induced salt stress and that marginal features at both a population and functional level are more likely to exhibit significant structural shifts based on salt specificity. The lack of uniformity in community response highlights the need to consider the compositional complexities of salinization to accurately identify the ecological consequences of instances of salt pollution., (© 2024 The Authors. Environmental Microbiology published by John Wiley & Sons Ltd.)

Reverse osmosis (RO) effectively provides clean drinking water. Different RO membrane types are tailored to treat saline water feeds with varying characteristics. In the context of low brackish water feeds, the objective is to remove only a minimal excess of salinity through the membrane. Our study introduces a method of membrane post-treatments capable of achieving controlled salt rejection while concurrently enhancing permeate flux, which is vital for achieving effective and energy-efficient desalination of low brackish water. The post-treatments were conducted on our in-house-developed membranes using aqueous solutions of N,N-Dimethylformamide and glycerol for different drying times at the coupon level. The process was scaled up at the module level, allowing us to assess its potential for commercial application. At the coupon level, the permeate flux increased significantly from 3.7 ± 0.9 to 10.6 ± 0.2 L/m 2 ·h·bar, while the salt rejection decreased from 95.6 ± 1% to 70.5 ± 1% when measured with a feed of 2,000 ppm NaCl concentration. At the module level, we observed a higher flux of 12.8 L/m 2 ·h·bar, alongside a salt rejection of 55.5% with a similar feed. Varying post-treatment parameters at the coupon level allowed us to attain the desired salt rejection and permeate flux values. Physical changes in both pristine and post-treated membranes, including polymer swelling, were observed without chemical alterations, enhancing our understanding of the post-treatment effect and its potential for broader commercial use. PRACTITIONER POINTS: Post-treatment of RO membranes enhances flux. Physical structuring through polymer swelling was observed with the chemical structure unaltered. Post-treatment of RO opens doors for broader energy-efficient desalination application., (© 2024 Water Environment Federation.)

In 2011, Texas experienced record heat and drought that escalated concerns about environmental flows for rivers. In response to these worries, fishes and water quality were sampled in the Lower Neches River, Texas, from May-August 2012 during continued drought. Potential effects of hydrology on environmental parameters and assemblages of small (seine samples) and large (gillnet samples) fishes were evaluated at multiple locations. Approximately 1 km downstream from the saltwater barrier, paper mill effluent discharges into the river. Salinity was higher and dissolved oxygen lower below the saltwater barrier during low-flow intervals. Fish species richness in seine samples, was higher when the barrier was open, and species richness for both gear types was lowest at sites closest to the paper mill effluent discharge. Overall, species richness was higher at sites below the barrier, with more estuarine and marine species present. When the barrier was closed, richness and abundance of sensitive freshwater species were lower below the barrier. Closure of the barrier during drought results in accumulation of dissolved organic compounds from paper mill effluent and lower dissolved oxygen in the reach below the barrier. To sustain biodiversity in the system, subsistence flows must pass across the saltwater barrier during droughts.

Purpose: Water retention capacity (WRC) is crucial for assessing the hydro-physical behavior of unsaturated soils. Dispersive soil, erodible and found mainly in arid regions, lacks sufficient WRC knowledge, hindering its stability evaluation in unsaturated state. This study aimed to explore the WRC of dispersive soil by measuring its matric suction (ψ) under coupling effects of dry density (ρd) and soluble salt content (η). Materials and method: Compacted specimens with different ρd and η were prepared. For each ρd-η case, six levels of soil mass water content were considered and the ψ was measured via filter paper method. Soil water characteristic curves (SWCCs) were fitted by van Genuchten model. Results and discussion: The WRC of dispersive soil enhances as ρd increases. Increasing η first weakens then strengthens the WRC, showing suction dependence. The air-entry value and residual state suction range within 0.95–17.8 kPa and 15.7–98.4 MPa, respectively. As for the air-entry value, increasing η from 0.3% to 2.0% decreases it from 36.0% to 58.7% when ρd increases, and its average growth rate changes from 174.5% to 265.3% when ρd exceeds 1.53 g/cm3. Increasing ρd reduces the average water loss rate of SWCC transition stage, while the impact of η is nonmonotonic, with an inflection point at 1.0%. Conclusions: The ρd and η influenced the WRC of dispersive soil individually and interactively. The effect of ρd links to the water release sequence from pores of different sizes, whereas that of η, rather complex and non-monotonic, relates to clay electrochemistry and salt phase. [ABSTRACT FROM AUTHOR]

Plants cannot move, so they must endure abiotic stresses such as drought, salinity and extreme temperatures. These stressors greatly limit the distribution of plants, alter their growth and development, and reduce crop productivity. Recent progress in our understanding of the molecular mechanisms underlying the responses of plants to abiotic stresses emphasizes their multilevel nature; multiple processes are involved, including sensing, signalling, transcription, transcript processing, translation and post-translational protein modifications. This improved knowledge can be used to boost crop productivity and agricultural sustainability through genetic, chemical and microbial approaches., (© 2021. Springer Nature Limited.)

Groundwater salinization is one of the most severe environmental problems in coastal aquifers worldwide, causing exceeding salinity in groundwater supply systems for many purposes. High salinity concentration in groundwater can be detected several kilometers inland and may result in an increased risk for coastal water supply systems and human health problems. This study investigates the impacts of groundwater pumping practices and regional groundwater flow dynamics on groundwater flow and salinity intrusion in the coastal aquifers of the Vietnamese Mekong Delta using the SEAWAT model-a variable-density groundwater flow and solute transport model. The model was constructed in three dimensions (3D) and accounted for multi-aquifers, variation of groundwater levels in neighboring areas, pumping, and paleo-salinity. Model calibration was carried for 13 years (2000 to 2012), and validation was conducted for 4 years (2013 to 2016). The best-calibrated model was used to develop prediction models for the next 14 years (2017 to 2030). Six future scenarios were introduced based on pumping rates and regional groundwater levels. Modeling results revealed that groundwater pumping activities and variation of regional groundwater flow systems strongly influence groundwater level depletion and saline movement from upper layers to lower layers. High salinity (>2.0 g/L) was expected to expand downward up to 150 m in depth and 2000 m toward surrounding areas in the next 14 years under increasing groundwater pumping capacity. A slight recovery in water level was also observed with decreasing groundwater exploitation. The reduction in the pumping rate from both local and regional scales will be necessary to recover groundwater levels and protect fresh aquifers from expanding paleo-saline in groundwater., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Migration of clay fines can be a concern when less saline fluids are injected into brine-saturated sandstone formations containing clays. If the salinity near fluid injection wells decreases below a critical value, the clay fines near the injection may detach, start migrating, and finally clog the pores. This effect can cause permeability decline near the well and may rapidly reduce the well injectivity. The focus of this work is on evaluating the impacts of clay fines migration on permeability decline in the field, using a numerical model and pressure buildup data collected during successive variable-rate water injections in a deep sandstone reservoir. The numerical model accounts for the mixing of low-salinity water with native brine and the migration of clay fines with the detachment and pore-clogging processes. The model interpretation of the pressure buildup data implies that the observed reduction in well injectivity is mainly associated with the clay fines migration and related pore clogging near the well. The model reasonably well represents the pressure buildup data during the injections. Our simulations demonstrate that the permeability near the well can rapidly decline within the first hour of injection. The measured pressure buildup in post-injection periods appears to decay more rapidly, compared to the simulation results of the model that assume irreversible permeability damage. This raises the question whether the permeability damage may be partly reversible near the well by backflow of brine after the injection of low-salinity water., (© 2021 National Ground Water Association.)

Rice is the most salt-sensitive cereal, suffering yield losses above 50% with soil salinity of 6 dS/m. Thus, understanding the mechanisms of rice salinity tolerance is key to address food security. In this chapter, we provide guidelines to assess rice salinity tolerance using a high-throughput phenotyping platform (HTP) with digital imaging at seedling/early tillering stage and suggest improved analysis methods using stress indices. The protocols described here also include computer scripts for users to improve their experimental design, run genome-wide association studies (GWAS), perform multi-testing corrections, and obtain the Manhattan plots, enabling the identification of loci associated with salinity tolerance. Notably, the computer scripts provided here can be used for any stress or GWAS experiment and independently of HTP.

I thank the discussors for their critique of the above paper. In geology there are rarely any absolute models but working hypotheses, which will be modified with new data. The paper under discussion, Charrach (Carbonates Evaporites 33:727–766, 2018a), presents a very new large data set, which is multi-disciplinary and integrated the most recent research. The critique by Möller et al. (Carbonates Evaporites 10.1007/s13146-019-00486-3, 2019) and their paper of 2018 (Int J Earth Sci 107:2409–2431, 2018), presents a computer simulation, which must be validated with field evidence and recent research in the area, and not based on assumptions, which have turned into facts over time. The discussors may be unfamiliar with the geological research that has been published over the last 20 years in the areas under consideration. Furthermore, the research on marine–non-marine evaporite formations is hardly considered in their discussion, yet much has been published. [ABSTRACT FROM AUTHOR]

Paper-based microfluidic devices have many advantages such as low cost, flexibility, light weight and easy disposability. Especially, since they can intrinsically generate capillary-driven flow (no pumps are needed), paper-based microfluidic devices are widely used in analytical or diagnostic platforms. Along with advancements in microfluidic paper-based analytical devices (μPADs), energy generation using paper materials has received significant attention. In this study, environment-friendly and flexible paper-based energy harvesting with a simple configuration is demonstrated by using the principle of reverse electrodialysis (RED). RED is a promising clean energy generation method, which converts Gibbs free energy into electricity by salinity gradients without discharging any pollutants. However, the power efficiency in a conventional RED device is limited by the essential requirement of active pumping for providing high and low concentration electrolytes. Capillary pumping from the proposed paper-based RED can save this waste of energy, and moreover, the flexible device is realized with cost effective materials and a simple fabrication step, and is environmentally friendly. By thoughtful analysis of voltage–current experiments and capillary flow rates in paper channels, the optimized channel width interfacing with a selective membrane is determined as 2 mm and the maximum power and power density are achieved as 55 nW and 275 nW cm−2, respectively. 25.8% of the generated maximum power is successfully saved by realizing the pumpless RED system. This paper-based RED device can be integrated directly with μPADs as a practical application. [ABSTRACT FROM AUTHOR]

Along with sea-level rise, one of the most detrimental effects of climate change, is salinity leakage, which significantly affects agricultural activities throughout most of the world. This occurrence is becoming increasingly dangerous. The purpose of this study was to use Geographical Information Systems (GIS) to assess the current situation of agricultural lands in the province of Al-Diwaniyah, by employing GIS to document the salt-affected sites and arrive at the most important criteria affecting those lands as well as build an application model for suitability to clarify the affected sites and come up with paper and digital maps. To accomplish this, the study relied on the available data by extrapolating and analyzing remote sensing images using salt equations to analyze the Landsat 8 satellite images, after which these data were subjected to spatial statistical treatment in ArcGIS software. Moreover, 20 samples were taken from ground sampling points and subjected to laboratory analysis to compare and document the results. The research resulted in the creation of an up-to-date database for the locations of salt ratio growth or decrease in the province of Al-Diwaniyah, which can be relied on, starting from and expanding in the future. Land maps, both paper and digital, have been created and can be used and inferred. The findings demonstrated the model's ability to steadily discriminate among all salinity groups while maintaining consistency with the ground truth data. Each of the four major salinity categories was highlighted. The best-performing indicators were used to build the MLR model, which was then used to anticipate soil salinity. The salt levels may be determined by the MLR combining NDVI and SI-5 with a high correlation value (R2 = 75.29%). Finally, it is shown that by combining spectral indicators with field measurements, it is possible to chart and forecast soil salinity on a large scale. [ABSTRACT FROM AUTHOR]

Groundwater resources are increasingly under demand to support human activities and economic development. This naturally clean resource is threatened by human and natural pollutions. Protecting groundwater has become a challenge for both urban and rural communities. This work aims to develop a simple and effective approach to assess the risk of aquifer pollution and the delineation of risk zones. To do so, an aquifer risk index (ARI) was presented as an overall indicator of the risk of groundwater pollution. The ARI is calculated using the groundwater vulnerability index (GVI) and the normalized water quality index (WQI). The multi-linear regression (MLR) model was used to assign weights to each parameter. This model has been applied and validated in the Koutine area of southern Tunisia. The results revealed that the groundwater in the study area is characterized by low and moderate risk. Fifty-six percent (56%) of the total study area presents a low risk. The remaining 44% of the study area is classified as medium risk, primarily in the Wadi and Lowland plains. ARI considers the intrinsic characteristics of the aquifer and groundwater quality when assessing the risk of pollution. The approach developed for assessing groundwater risks is simple to implement, realistic, and efficient. AVI is a parametric approach that uses aquifer data without losing information. This method can assist academics and groundwater resource managers in delineating risk areas to protect groundwater resources from pollution., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: The experiment was conducted at the Faculty of Agriculture and Veterinary Medicine, An-Najah National University, Palestine under growth chamber and greenhouse conditions. Methods: To study the effect of NaCl on germination, fifty seeds in each treatment for each cultivar were germinated on a filter paper in petri dishes moistened with the different NaCl concentration levels (0.0, 50 and 100 mM ). To study the effect of NaCl on plant growth and productivity, 2 seeds per variety were grown in 10 liter pots filled with peat moss-sand. Pots were irrigated with the different NaCl levels. Result: The tested chickpea cultivars showed different tolerance levels in response to NaCl stress levels. NaCl reduced final germination percentage (FGP) and germination index (GI). The highest plant height was obtained by Einalbeda (38.63 cm) in the control group, while the lowest one was found in Arij (28.25 cm) under 100 mM NaCl. NaCl did not affect root/shoot ratio in all genotypes. Reduction in fresh weight ranged between 25.6 and 74.2% under 50 and 100 mM NaCl. [ABSTRACT FROM AUTHOR]

In 2011, Texas experienced record heat and drought that escalated concerns about environmental flows for rivers. In response to these worries, fishes and water quality were sampled in the Lower Neches River, Texas, from May-August 2012 during continued drought. Potential effects of hydrology on environmental parameters and assemblages of small (seine samples) and large (gillnet samples) fishes were evaluated at multiple locations. Approximately 1 km downstream from the saltwater barrier, paper mill effluent discharges into the river. Salinity was higher and dissolved oxygen lower below the saltwater barrier during low-flow intervals. Fish species richness in seine samples, was higher when the barrier was open, and species richness for both gear types was lowest at sites closest to the paper mill effluent discharge. Overall, species richness was higher at sites below the barrier, with more estuarine and marine species present. When the barrier was closed, richness and abundance of sensitive freshwater species were lower below the barrier. Closure of the barrier during drought results in accumulation of dissolved organic compounds from paper mill effluent and lower dissolved oxygen in the reach below the barrier. To sustain biodiversity in the system, subsistence flows must pass across the saltwater barrier during droughts. [ABSTRACT FROM AUTHOR]

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Energy is one of the critical resources determining the overall socioeconomic development. Global warming and natural resource demand had made the world to look into renewable energy like solar, wind, and fuel cells. Salinity gradient energy is the concept of extraction of energy from the concentration gradient between saline and clean solution. In this review, we present different novel systems to generate electricity by salinity gradients by reverse electrodialysis technology integrated with capacitive electrodes and also different types of reverse electro dialysis. This capacitive reverse electrodialysis system synergistically combines previous developments in capacitive mixing and reverse electrodialysis. This review work consists of the study of various reverse electrodialyses, comparing the recent advancements with the novel process and integrates the various results and experiments, and reviews of all reverse electrodialysis are incorporated., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Three trials were conducted to evaluate the performances of red snapper, Lutjanus campechanus, in low salinities. The median lethal concentration (96 h LC50) of salinity was determined by trimmed Spearman-Karber method using survival data of fish (18.9 ± 0.2 g) collected after 96 h from acclimation to 2, 4, 8, and 32 ppt salinities in 800 L tanks (n = 3), while the serum osmolality of fish (74.1 ± 3.9 g) was determined after 48 h from acclimation to 6, 8, 16, 24, and 32 ppt salinities in 150 L tanks (n = 3). The growth trial was conducted for 6 weeks in 800 L tanks to determine the growth and survival of fish (18.8 ± 0.2 g) at 8 ppt salinity compared to the control (32 ppt salinity). At the conclusion, the isosmotic point of fish was estimated as 357.2 mmol/kg (correspond to 11.0 ppt salinity), while the 96 h LC50 was estimated as 5.65 ppt salinity. No significant differences were noted for survival and FCR of fish reared in 8 and 32 ppt salinities. However, growth was significantly lower in fish reared in 8 ppt salinity compared to the fish reared in 32 ppt salinity. The reduced growth could be, at least partially, due to the increased osmoregulatory energy expenditure at lower salinities., (© 2021. The Author(s), under exclusive licence to Springer Nature B.V.)

This study was conducted during 2019-2020 on the vegetative shoots of date palm Phoenix dactylifera L. cultivar 'Barhee', which were grown on MS salt media containing sodium chloride (0-25-50-100-150-200 mM) supplemented with 5% sucrose. Genetic variances were assessed using molecular markers RAPD using 8 random primers. The RAPD analysis did not result a polymorphism between the amplified bundles and the absence of genetic differences. The primer (OPE-19 and OPD-10) scored the lowest similarity rate 97%, while the genetic matching was 100% in the other primers. The morphological indicators recorded a significant and gradual decrease in the growth indicators (buds number, bud length and stem length) and a significant increase in (bud diameter and branches number) in the propagation and elongation stages. Also, the chemical growth indicators recorded an increase in the chemical content (abscisic acid and proline), the effect of Sodium chloride was negative on photosynthesis, as the chlorophyll content gradually decreased with increasing sodium chloride concentration. [ABSTRACT FROM AUTHOR]

Roots have important roles for plants to withstand adverse environmental conditions, including salt stress. Biostimulant application was shown to enhance plant resilience towards abiotic stresses. Here, we studied the effect of a tannin-based biostimulant on tomato (Solanum lycopersicum L.) grown under salt stress conditions. We investigated the related changes at both root architecture (via imaging and biometric analysis) and gene expression (RNA-Seq/qPCR) levels. Moreover, in order to identify the main compounds potentially involved in the observed effects, the chemical composition of the biostimulant was evaluated by UV/Vis and HPLC-ESI-Orbitrap analysis. Sixteen compounds, known to be involved in root development and having a potential antioxidant properties were identified. Significant increase of root weight (+ 24%) and length (+ 23%) was observed when the plants were grown under salt stress and treated with the biostimulant. Moreover, transcriptome analysis revealed that the application of the biostimulant upregulated 285 genes, most of which correlated to root development and salt stress tolerance. The 171 downregulated genes were mainly involved in nutrient uptake. These data demonstrated that the biostimulant is able not only to restore root growth in salty soils, but also to provide the adequate plant nourishment by regulating the expression of essential transcription factors and stress responsive genes.

Saltwater intrusion (SWI) is a global coastal problem caused by aquifer overpumping, land-use change, and climate change impacts. Given the complex pathways that lead to SWI, coastal urban areas with poorly monitored aquifers are in need of probabilistic-based decision support tools that can assist in better understanding and predicting SWI, while exploring effective means for sustainable aquifer management. In this study, we develop a Bayesian Belief Network (BBN) to account for the complex interactions of climatic and anthropogenic processes leading to SWI, while relating the severity of SWI to associated socioeconomic impacts and possible adaptation strategies. The BBN is further expanded into a Dynamic Bayesian Network (DBN) to assess the temporal progression of SWI and account for the compounding uncertainties over time. The proposed DBN is then tested at a pilot coastal aquifer underlying a highly urbanized water-stressed metropolitan area along the Eastern Mediterranean coastline (Beirut, Lebanon). The results show that the future impacts of climate change are largely secondary when compared to the persistent water deficits. While both supply and demand management could halt the progression of salinity, the potential for reducing or reversing SWI is not evident. The indirect socioeconomic burden associated with aquifer salinity was observed to improve, albeit heterogeneously, with the application of various adaptation strategies; however, this was at a cost associated with the implementation and operation of these strategies. The proposed DBN acts as an effective decision support tool that can promote sustainable aquifer management in coastal regions through its robust representation of the main drivers of SWI and linking them to expected socioeconomic burdens and management options. Integr Environ Assess Manag 2021;17:202-220. © 2020 SETAC., (© 2020 SETAC.)

The present study first describes the variations in concentrations of 12 chemical elements in groundwater relative to salinity levels in Southern Quebec (Canada) groundwater systems, and then uses this data to develop an empirical predictive model for evaluating groundwater chemical composition relative to salinity levels. Data is drawn from a large groundwater chemistry database containing 2608 samples. Eight salinity classes were established from lowest to highest chloride (Cl) concentrations. Graphical analyses were applied to describe variations in major, minor, and trace element concentrations relative to salinity levels. Results show that the major elements were found to be dominant in the lower salinity classes, whereas Cl becomes dominant at the highest salinity classes. For each of the major elements, a transitional state was identified between domination of the major elements and domination of Cl. This transition occurred at a different level of salinity for each of the major elements. Except for Si, the minor elements Ba, B, and Sr generally increase relative to the increase of Cl. The highest Mn concentrations were found to be associated with only the highest levels of Cl, whereas F was observed to be more abundant than Mn. Based on this analysis of the data, a correlation table was established between salinity level and concentrations of the chemical constituents. We thus propose a predictive empirical model, identifying a profile of the chemical composition of groundwater relative to salinity levels, to help homeowners and groundwater managers evaluate groundwater quality before resorting to laborious and costly laboratory analyses. [ABSTRACT FROM AUTHOR]

The stratigraphic and temporal framework of the sedimentary filling of the Messinian–Zanclean transition in Malaga basin is discussed. From this framework, the main features of an alternative model for the Lago-Mare event in the Mediterranean are outlined. [ABSTRACT FROM AUTHOR]

Salinity is a crucial environmental problem leading to profound consequences in wetland plants and aquatic habitats including the rapid development of Phragmites australis in the marshland. These Phragmites australis are extremely vulnerable to capture fire, which might eventually affect the overall ecosystem of the marsh. However, in order to restore the marsh, a hydrologic investigation is needed, which is possible if a watershed is gauged, and long-term data are available. In this study, a systematic approach has been presented to conduct hydrologic modeling and salinity prediction in an ungauged watershed in order to implement the possible removal of salt fill sites. The stage and electrical conductivity were measured continuously, whereas stream cross sections and velocity of the streamflow were recorded intermittently in the Blackbrook Creek to develop a rating curve and generate continuous streamflow data. The watershed model Soil and Water Assessment Tool (SWAT) was calibrated and validated to a monthly scale with good model performance. In the next step, critical sources of salinity were identified from the two tributaries in order to implement the removal of salt fill sites for the possible reduction of salinity in the marsh. While salinity loading was approximately 10 times higher from Marsh Creek (65.63 tons to 2028.13 tons per month) compared with Blackbrook Creek (10.23 tons to 163.98 per month), the analysis suggested that salinity concentration was higher from Blackbrook Creek, which was particularly due to abandoned salt fill sites near the Creek. The salinity loadings were linearly correlated with streamflow on a monthly (R 2  = 0.81) scale, which was utilized to generate the salinity loadings that were diverted due to the rerouting of the Creek through the new location in order to avoid salt fill sites and reduce salinity in the Mentor Marsh. Our analysis suggested that approximately 74 kg/day salinity was being rerouted from the Marsh; however, the salt fill sites contribute salinity to the Marsh equivalent to 63 kg/day, which still needs to be removed. The research findings are expected to be helpful for monitoring small ungauged watersheds.

This paper introduces a potential method for the remote sensing of sea surface salinity (SSS) using measured propagation delay of low-frequency Loran-C signals transmitted over an all-seawater path between the Sylt station in Germany and an integrated Loran-C/GPS receiver located in Harwich, UK. The overall delay variations in Loran-C surface waves along the path may be explained by changes in sea surface properties (especially the temperature and salinity), as well as atmospheric dynamics that determine the refractive index of the atmosphere. After removing the atmospheric and sea surface temperature (SST) effects, the residual delay revealed a temporal variation similar to that of SSS data obtained by the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) satellite. [ABSTRACT FROM AUTHOR]

A compilation of several cruises data from 1998 to 2013 was used to derive polynomial fits that estimate total alkalinity (AT) and total inorganic carbon (CT) from measurements of salinity and temperature in the Mediterranean Sea surface waters. The optimal equations were chosen based on the 10-fold cross validation results and revealed that a second and third order polynomials fit the AT and CT data respectively. The AT surface fit showed an improved root mean square error (RMSE) of ±10.6 μmol kg-1. Furthermore we present the first annual mean CT parameterization for the Mediterranean Sea surface waters with a RMSE of ±14.3 μmol kg-1. Excluding the marginal seas of the Adriatic and the Aegean, these equations can be used to estimate AT and CT in case of the lack of measurements. The seven years averages (2005-2012) mapped using the quarter degree climatologies of the World Ocean Atlas 2013 showed that in surface waters AT and CT have similar patterns with an increasing eastward gradient. The surface variability is influenced by the inflow of cold Atlantic waters through the Strait of Gibraltar and by the oligotrophic and thermohaline gradient that characterize the Mediterranean Sea. The summer-winter seasonality was also mapped and showed different patterns for AT and CT. During the winter, the AT and CT concentrations were higher in the western than in the eastern basin, primarily due to the deepening of the mixed layer and upwelling of dense waters. The opposite was observed in the summer where the eastern basin was marked by higher AT and CT concentrations than in winter. The strong evaporation that takes place in this season along with the ultra-oligotrophy of the eastern basin determines the increase of both AT and CT concentrations. [ABSTRACT FROM AUTHOR]

The marine context of the Lago Mare deposit near Malaga has received agreement as well as its ascription to the third Lago Mare event of Clauzon et al. (2005). This deposit is not a “transitional unit towards normal marine conditions” but followed the marine reflooding of the Mediterranean Basin, allowing the connection with the Dacic Basin (Eastern Paratethys). We show that this Lago Mare event did not result from a climatic change leading to a dilution episode but from a high sea-level connection. Different interpretations on the respective effects of tectonics and eustatism on the sedimentary archives linked to the Messinian Salinity Crisis (MSC) are once more debated. They depend on (1) the duration assigned to the MSC and its subdivisions, (2) the amplitude of the successive sea level variations, and at last (3) the dimensional (local or regional) view of the MSC. Such discrepancies concern subsidiary matters which cannot mask first order facts and progresses in their knowledge. [ABSTRACT FROM AUTHOR]

Aiming at the problem of long soil–water characteristic curve (SWCC) testing times and the difficulty of prediction accuracy in complex environments, this paper establishes a SWCC prediction model based on a neural network machine learning algorithm which can take into account the influence of multiple factors such as temperature, deformation, and salinity. The input layer of the model can reflect the physical properties of the soil and the influence of the external environment, while the suction is taken as an input variable, which in turn can directly obtain the water content under the corresponding conditions. The predictive ability of the model is verified by comparing and analyzing the predicted results of the SWCC under different temperature, void ratio, and salinity conditions with the experimental results. The research in this paper provides a new method for predicting the SWCC considering multiple factors, and the prediction accuracy of the model is related to the amount of experimental data. [ABSTRACT FROM AUTHOR]

The thickness of the thin wetting film depends on disjoining pressure forces, and it evolves with pH evolution due to brine acidification at the physical and chemical conditions of geological carbon dioxide storage becoming thinner in response to dewetting. In the literature, molecular dynamic simulation (MDS) studies have been employed to understand the effect of pressure/capillary pressure on the thin wetting film evolution. In this paper, a theoretical approach based on the Frumkin–Derjaguin Equation (FDE), models of electric double layer repulsion, and van der Waals forces have been used for the calculation of the wetting film thickness. The approach excluded hydration forces contribution to disjoining pressure forces due partly to its poorly understood nature, and partly to the high salinity conditions encountered in geological carbon storage. Due to its promising global storage capacity compared to other lithologies, the carbon dioxide–brine–silica systems was chosen to simulate sandstone saline aquifers. The validation of the model benefited much from literature resources on data and a universal model of carbon dioxide–brine interfacial tension. Calculated results confirm pH-induced dewetting and they follow trends controlled by pH and pressure as found in the literature. The novelty of the paper can be seen from the fact that it has demonstrated a theoretical supplement to MDS studies in addition to justifying the fundamental utility and versatility of the FDE. Moreover, the paper links for the first time, a transcendental equation to the thin wetting film theory encountered in the carbon dioxide–solid–brine system found in geological carbon storage. [ABSTRACT FROM AUTHOR]