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Penstemon, with more than 250 species native to North America, holds significant aesthetic and ecological value in Utah, supporting diverse pollinators. Despite their significance, the survival of penstemon is threatened by challenges such as habitat loss, climate change, and Utah’s naturally high soil salinity. To address these challenges and understand their adaptability, this study evaluated the salt tolerance of two penstemon species [Penstemon davidsonii (Davidson’s penstemon) and Penstemon heterophyllus (foothill penstemon)] under controlled greenhouse conditions. The aim was to develop baseline information for nursery production and landscape use that utilize reclaimed water for irrigation. Plants were irrigated weekly with a nutrient solution at an electrical conductivity (EC) of 1.0 dS·m-1 as control or a saline solution at an EC of 2.5, 5.0, 7.5, or 10.0 dS·m-1 for 8 weeks. Half of the plants were harvested after four irrigation events, and the remaining plants were harvested after eight irrigation events. At harvest, visual rating (0 = dead and 5 = excellent without foliage salt damage), plant width, number of shoots, leaf area, shoot dry weight, leaf greenness [Soil Plant Analysis Development (SPAD)], stomatal conductance, and canopy temperature were collected to assess the impact of salinity stress. In both species, salt damage was dependent on the salinity levels and length of exposure. After four irrigation events, both species exhibited foliage damage that increased in severity with rising EC. The most severe damage was observed in plants receiving saline solution at an EC of 10.0 dS·m-1. After eight irrigation events, P. davidsonii exposed to a saline solution with an EC of 10.0 dS·m-1 received a visual rating of 0, whereas P. heterophyllus had a visual rating of 0.4. Both species exhibited salinity-induced effects, with variations observed in the specific parameters and the degree of response. Penstemon davidsonii exhibited significant salinity stress, as indicated by reduced leaf area, shoot dry weight, SPAD reading, and stomatal conductance with increasing EC of the saline solution. In addition, in both species, at both harvests, canopy temperatures increased either linearly or quadratically by 8% to 36% as the EC levels of the saline solution increased. These results indicate that P. davidsonii was more sensitive to salinity stress than P. heterophyllus. [ABSTRACT FROM AUTHOR]

Momordica charantia (bitter cucumber) is a tropical and subtropical plant with a long history of use in traditional medicine. Salinity is a major problem that limits plant growth and biomass production. The aim of this work was to determine the salinity tolerance of bitter cucumber, through the spectral analyses of some metabolites involved in their response to abiotic stress factors. To carry out the experiment, two varieties of bitter cucumber and three experimental lines were subjected to saline stress by applying treatments with saline solutions in different concentrations (control—0 mM NaCl; V1—100 mM NaCl; and V2—200 mM NaCl). After applying the treatments, analyses were carried out on the amount of free proline (Pro), ascorbic acid, and aromatic amino acids. For proline and ascorbic acid, the tendency was for their concentration to decrease in the variants treated with saline solutions" with "the tendency was for their absorbance to decrease in the variants treated with saline solutions. The differences between the controls and the treated variants, as well as between the studied genotypes, highlight their capacity for resistance and adaptation to saline stress. [ABSTRACT FROM AUTHOR]

In this study, two laterites (LA)-based geopolymers were synthesized using alkalination (GPAL) and phosphoric acid-activation (GPAC) approaches and applied to scavenge malachite green (MG) dye from aqueous (non-saline) and saline water. The precursor (LA) and geopolymers were characterized by XRF, XRD, TG/DTA SEM, and FTIR techniques. Alkalination and acid-activation resulted in morphologically distinguishable geopolymers with different porosity structures. The dissolution of mineral phases and chemical composition was dependent on the activation medium, resulting in Na-polyferrosialate and polyferrophosphosialate geopolymers for GPAL and GPAC, respectively. The adsorption kinetics data were best described by the pseudo-first-order (PFO) model wherein the adsorption rate, denoted by rate constant (k 1), increased with an increase in ionic strength (salinity). The equilibrium data were best modelled by the Sips isotherm. GPAL had a higher maximum adsorption capacity (Q ms) than GPAC in both aqueous (non-saline) and saline water. The adsorption capacities were increased in saline solution relative to aqueous solutions without NaCl, from 12.4 to 54.1 mg/g and from 57.1 to 92.0 mg/g for GPAC and GPAL, respectively. The adsorption mechanism entailed electrostatic interactions, hydrogen bonding and hydrophobic interactions. Salinity decreased the solubility of MG and increased the hydrophobic interactions and affinity of MG, implied by apparent equilibrium constant (K a), resulting in increased adsorption density (Q ms). These results indicate that alkaline-based geopolymers are better candidates for scavenging MG dye from water, especially in saline environments. [ABSTRACT FROM AUTHOR]

Penstemons are a diverse group of flowering plants valued for their ability to enhance the visual appearance of urban landscapes. Penstemon barbatus (Cav.) Roth 'Novapenblu' (rock candy blueVR penstemon) and Penstemon strictus Benth 'Rocky Mountain' (rocky mountain beardtongue) are widely used in landscapes, but their tolerance to soil salinity remains poorly understood. This study aimed to investigate the effects of salinity levels at electrical conductivities (ECs) of 1.0 (nutrient solution), 2.5, 5.0, 7.5, and 10.0 dS·m21 on two penstemons (P. barbatus and P. strictus). Penstemons were irrigated with nutrient or saline solution for 8 weeks and various growth and physiological data were recorded before harvest. Salinity stress degraded the visual quality of penstemon species and led to a reduction in the growth rate and biomass production. Leaf burn and necrosis were observed in penstemons because of salinity stress. The visual score of P. barbatus and P. strictus decreased with increasing EC levels in the saline solution. When irrigated with saline solution at an EC of 7.5 dS·m21, Penstemon barbatus and P. strictus had severe-to-moderate foliar salt damage with average visual scores of 1.7 and 2.5, respectively (0 5 dead plant; 5 5 excellent plant without any foliar damage). The two penstemon species had severe foliar salt damage or were dead when irrigated with saline solution at an EC of 10.0 dS·m21. There were 87% and 92% decreases in the leaf area of P. barbatus and P. strictus, respectively, when irrigated with saline solution at an EC of 10.0 dS·m21 compared with those in the control. Although not statistically significant, there were 7% to 18% decreases in shoot dry weight of P. barbatus when irrigated with saline solutions at ECs of 2.5 to 10.0 dS·m21 compared with control. However, P. strictus displayed declines of 13% to 31% in shoot dry weight as the salinity levels of the irrigation solution increased. As the salinity levels increased, the net photosynthetic rate (Pn), stomatal conductance (gs), and transpiration (E) rates decreased. Furthermore, sodium (Na+) and chloride (Cl2) contents of P. barbatus and P. strictus increased with the increase in salinity levels of the treatment solution. Consequently, P. barbatus and P. strictus demonstrated sensitivity to salinity stress at ECs of 7.5 and 10.0 dS·m21. This study provides important insights for their effective utilization in landscaping practices within saline-prone areas. [ABSTRACT FROM AUTHOR]

Three small-scale mock-up tests were carried out on artificially fractured Opalinus Clay samples from the lower sandy facies of Mont Terri site: the first with the synthetic water of neutral pH and at an osmotic suction of 1 MPa, the second with a highly NaNO3 saline solution with a neutral pH and at osmotic suction of 34 MPa, and the third with a hyperalkaline solution at pH = 13.5 and at osmotic suction of 1.16 MPa. The radial swelling pressure was monitored using a total pressure sensor along with the fracture opening using a displacement transducer. The tests ran for over 290 days. After that, the three tests were dismantled. A detailed petrophysical characterization of 45 subsamples was conducted, and the pore size distribution was determined at different positions. X-ray diffractometry measurements were also conducted to identify any mineralogical changes. Results show that, in the case of the synthetic water and the alkaline solution, the friction forces exerted by the lid and the base on the sample were significant and probably hampered the self-sealing of the fracture. Saline solutions affect the self-sealing process of claystones. Indeed, even though increasing the salinity caused the contraction of the diffuse double layer and generated additional fractures within the sample, which increased the permeability and thus accelerated the hydration process, a complete self-sealing of the fracture opening was not observed. [ABSTRACT FROM AUTHOR]

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

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

Background: Quinoa (Chenopodium quinoa Willd.) is a facultative halophyte showing various mechanisms of salt resistance among different ecotype cultivars. This study aimed to determine salt resistance limits for a Peruvian sea level ecotype "Hualhuas" and a Bolivian salar ecotype "Real" and elucidate individual mechanisms conferring differences in salt resistance between these cultivars. The plants were grown in sandy soil and irrigated with various saline solutions concentrations (0, 100, 200, 300, 400, and 500 mM NaCl) under controlled conditions. Results: High salinity treatment (500 mM NaCl) reduced the plant growth by 80% and 87% in Hualhuas and Real cultivars, respectively. EC50 (water salinity which reduces the maximum yield by 50%) was at a salinity of 300 mM NaCl for Hualhuas and between 100 and 200 mM NaCl for Real plants. Both cultivars were able to lower the osmotic potential of all organs due to substantial Na+ accumulation. However, Hualhuas plants exhibited distinctly lower Na+ contents and consequently a higher K+/Na+ ratio compared to Real plants, suggesting a more efficient control mechanism for Na+ loading and better K+ retention in Hualhuas plants. Net CO2 assimilation rates (Anet) were reduced, being only 22.4% and 36.2% of the control values in Hualhuas and Real, respectively, at the highest salt concentration. At this salinity level, Hualhuas plants showed lower stomatal conductance (gs) and transpiration rates (E), but higher photosynthetic water use efficiency (PWUE), indicative of an efficient control mechanism over the whole gas-exchange machinery. Conclusion: These results reveal that Hualhuas is a promising candidate in terms of salt resistance and biomass production compared to Real. [ABSTRACT FROM AUTHOR]

Coupling between solution salinity and the mechanics of charged hydrogels presents an opportunity to harvest osmotic energy in a clean and sustainable way. By applying mechanical pressure to retard the swelling or deswelling of hydrogels in saline solutions, the free energy of mixing is converted into mechanical work. This study developed a theoretical framework and experimentally investigated the potential of hydrogels for energy production from salinity gradients. Mathematical modeling revealed the effect of parameters including the charge and elastic modulus of hydrogels, applied pressure, and the solution salinity on energy conversion using different thermodynamic cycles. With proper material design and process control, the thermodynamic efficiency of an ideal process was predicted to exceed 5% with 10 mM and 600 mM NaCl solutions. Experiments with poly (styrene sulfonate) hydrogels verified the theoretically predicted trends and demonstrated more than 10% thermodynamic efficiency for moderate-salinity sources, due to the unique swelling-strengthened mechanical properties of the gels. The study suggests the potential of polyelectrolyte hydrogels in the extraction of energy from low- to moderate-salinity sources and provides a framework for their design. [ABSTRACT FROM AUTHOR]

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

The low seed germination response and seedling growth of crops to salinity is common problem in Pakistan. To overcome this problem, seed priming is used as an economic and effective approach. Present study was conducted to evaluate the effects of halopriming of seeds on germination, growth and yield of tomato under saline conditions. The seeds of tomato variety ‘Raja’ were primed with 0, 50 mM and 100mM of NH4NO3, KNO3, and (NH4)2SO4 solutions for 12 and 24 hours. The primed seeds were irrigated separately with tap water, saline water, and Hoagland solution with saline water. The results indicated that halopriming of tomato seeds with KNO3, NH4NO3 and (NH4)2SO4 significantly increased the germination percentage (GP) from 58% (unprimed) to 95% (primed) while decreased the mean germination time (MGT) from 7.44 days (unprimed) to 4.6 days (primed). A significant increase was observed in the height of plant, leaf area, number of leaves, shoot and root biomass, number of fruits per plant, etc. in primed plants irrigated with Hoagland solution under saline conditions. Similarly, the halopriming with NH4NO3 and KNO3 also enhanced the chlorophyll pigments, lycopene contents, total soluble sugars, total proteins, total phenolic contents and total flavonoids in primed plants irrigated with Hoagland solutions under salt stress. Furthermore, proline contents were increased in primed plants irrigated with NaCl solution as compared to other treatments and control. In conclusion, KNO3 and NH4NO3 are more effective priming agents than (NH4)2SO4 were positively affected the germination, plant height, physiological and biochemical attributes in tomato plants under saline and non-saline conditions. The supplement of Hoagland solution under salt stress further improves the morphological, physiological and biochemical attributes of tomato. [ABSTRACT FROM AUTHOR]

Summary: Salinity is one of the major environmental stresses limiting growth and yield of rice. The objective of the present study was to analyze the impact of NaCl on yield-related parameters of Oryza glaberrima. Two contrasted cultivars of Oryza glaberrima previously tested for salt resistance at the vegetative stage [salt-resistant (TOG5307) and salt-sensitive (TOG5949)] were irrigated with a saline solution containing 30 mM NaCl (EC: 3 dS.m−1 NaCl). After 6 months of treatments, mineral nutrient and yield-related parameters were assessed. Proline was quantified in the panicle leaf at the start of the grain filling stage. NaCl treatment affected most yield-related parameters: panicle length, panicle leaf dry weight, number of branches per panicle, panicle leaf length, days to 50% heading, straw fresh weight per plant, grain yield per plant, number of spikelets per panicle, and number of filled grains per panicle. The weight of 1,000 grains decreased in the salt-sensitive cultivar only, suggesting that grain filling processes were compromised. The salt-resistant cultivar TOG5307 was less affected than the salt-sensitive TOG5949 and accumulated lower amounts of Na+ in the grains. For both cultivars, hulls contained higher concentration of Na+ and K+ than grains. TOG5307 also contained more proline in the panicle leaf than TOG5949, suggesting that TOG5307 can cope with the osmotic component of salt stress. The cultivar exhibiting the highest salt resistance at the vegetative stage also exhibited the highest resistance at the reproductive one. [ABSTRACT FROM AUTHOR]

In the current study, different combinations of three products (Lithovit-Standard: Litho, monopotassium-phosphate: MKP and acetyl salicylic acid: ASA) were tested on tomato plants irrigated with five saline solutions (2, 4, 6, 8, and 10 dS/m). The aim was to determine the possible complementary effects of these products applied separately and in different sequence at vegetative (11DAT: days after transplantation), flowering (25DAT) and fruit formation (39DAT). Control salt-stress plants were not subjected to product application. The data showed that the combination Asp-Litho-MKP improved total chlorophyll content and reduced the most cell electrolyte leakage compared to control. ASP-MKP-Litho treatment improved fruit number by an average of three to four fruits compared to control at all EC levels and maximized weight of individual fruits under EC 2, 4, and 10 dS/m. Yields in plants treated with ASP-MKP-Litho were higher by almost two to three folds than those of control plants. Plants treated by ASP-MKP-Litho had the highest contents of N, P, K, Ca, and Mg at all ECs. It was concluded that the three products had complementary effects on salt-stressed tomato crop if applied in combination. [ABSTRACT FROM AUTHOR]

The economically profitable production of crops is related, among other factors, to seed quality, the production system, and the water used in irrigation or preparation of nutrient solutions. Therefore, the objective was to evaluate the phenology, production, and vigor of seeds of mini watermelons grown in saline nutrient solution and different substrates. In the fruit and seed production phase, the experiment occurred in a greenhouse with five electrical conductivities of water for nutrient solution preparation, ECw (0.5, 2.4, 4.0, 5.5, and 6.9 dS m−1), and two growing substrates (coconut fiber and sand). We evaluated the physiological quality of seeds previously produced under the five electrical conductivities of water and two substrates. High salinities for the hydroponic cultivation of the mini watermelon cultivar 'Sugar Baby' accelerated fruit maturation and crop cycle, decreasing fruit size. However, in both substrates, the seed production of mini watermelons, seed viability, and seed vigor occurred adequately with a reject brine of 6.9 dS m−1 in the hydroponic nutrient solution. The seed production of 'Sugar Baby' mini watermelons using reject brine in a hydroponic system with coconut fiber and sand substrates is viable in regions with water limitations. [ABSTRACT FROM AUTHOR]

Soil salinity is considered crucial for seed germination, seedling growth, and crop production in arid and semi-arid regions. Seed priming can be an effective solution to improve maize germination and growth, under salinity stress. An experiment was conducted to study the effect of seed priming with NaCl and salinity stress on germination and growth of maize variety Arun-2. Before sowing, eighty maize seeds were soaked in 5g/L aqueous NaCl solution for 12 hours at 27-degree Celsius. Primed and unprimed seeds were sown in 10-liter capacity plastic pots and watered with 200mL of 0, 2, 4, 6, and 8 g/L saline solutions at two days intervals. Germination percentage, shoot length, and number of leaves per plant were measured to access the germination and growth parameters. The results showed that priming seeds with NaCl solution significantly (P<0.05) improved the germination of maize seeds. Whereas, germination of Arun-2 was not significantly affected by salinity stress. Salinity has negative impacts on shoot length and number of leaves. The shoot length at 38 DAS was found to be the longest at salinity level 0 mg/L (8.61cm) and it was found to be shortest at highest salinity level i.e. 8 mg/L (3.12 cm). Increasing salt stress has severe effects on the growth of maize, both during the seedling and vegetative growth stages of the plant. Seed priming alleviated the inhibitory effect of salt stress on germination and seedling growth of maize. Thus, seed priming with 5 g/L NaCl solution could be useful to improve the germination and growth of maize under saline stress conditions. [ABSTRACT FROM AUTHOR]

The aim of this study was to synthesize amphiphilic semi-IPN hydrogels based on acrylic acid (AA) and chitosan (CS) using AIBN as an initiator and N,N'methylene bis acrylamide as a crosslinking agent. The swelling behavior of the hydrogels was evaluated at a variety of pH values, temperature, the salinity of media and time, and the swelling mechanism was investigated using Fickian diffusion and Schott's 2nd-order-kinetics models. FTIR spectroscopy was used to confirm the synthesis of AA/CS hydrogel. The swelling results showed that, in the acidic media, as the CS content increase the hydrogel swelling ratio reduces. It was found that the maximum swelling ratio (8550%) is attained for the sample HAC2 with an AA/CS ratio of 1:0.001 in the alkaline Ph value. It also revealed that the absorption capacity is directly dependent on the temperature and inversely related to the salt concentration. Besides, the absorption capacity of the synthesized hydrogels in the saline solution of Na2SO4 was higher than NaCl. [ABSTRACT FROM AUTHOR]

Soil salinity has been a limiting barrier for the production of vegetables in protected environments. Thus, the understanding of the sensitivity of species to this stress factor must be explored, seeking better growing conditions. Under the hypothesis that beet and radish crops are sensitive to variations in soil salinity, even at low levels, the objective of this work was to evaluate the development and productivity of these two species in soils with different salinities in a protected environment. The experimental design was completely randomized and treatments were formed by the soil salinity levels, obtained with the application of saline solution (NaCl in water), considering the soil electrical conductivity of 0.36 dS m-1 as low salinity, of 1.05 dS m-1 as moderate salinity and 2.43 dS m-1 as elevated. For all variables analyzed, except for the relative chlorophyll index in beet plants, it was found that the increase in soil salinity resulted in significant development losses of beet and radish plants. Therefore, we concluded that beet and radish crops are sensitive to the variation in soil salinity, even in relatively low concentrations, making these species an unattractive choice for cultivation in systems that present this problem. [ABSTRACT FROM AUTHOR]

Salinity is one of the limiting factors that negatively affect the germination, emergence, and development of pastures in the lower part of the Lauca - Oruro River sub-basin, reducing the availability of forages for livestock. With the purpose of identifying salinity tolerant forage species, the germination capacity in saline solutions of eight species was evaluated: Agropyron elongatum (Host) P. Beauv., Hordeum muticum J. Presl., Bromus catharticus Vahl., X. Triticosecale Wittmarck , Hordeum vulgare L., Atriplex cristata, Trifolium amabile (L.) Kunth., and Suaeda foliosa Moq. The research was carried out in laboratories of the Faculty of Agricultural and Natural Sciences - Technical University of Oruro; Saline solutions with four concentrations of NaCl per one liter of distilled water were applied to the seeds: 2.56, 5.12, 7.68, and 10.54 g, and control without salinity. The results indicate that X. Triticosecale Wittmarck and H. vulgare have greater tolerance to solutions of extreme salinity and little affected in their germination capacity. The seeds of A. elongatum, B. catharticus and S. foliosa significantly reduce germination, however, they manage to germinate at all salinity levels. The seeds of A. cristata and T. amabile are the most sensitive to saline affectation, germination is significantly reduced at all salinity levels, even at the highest concentration. It is concluded that these species can be used as forage for the use of salinized soils, depending on the maximum tolerance determined.

Background: Phaseolus vulgaris L.-rhizobia symbiosis has effectively enhanced common bean productivity via multiple biological mechanisms. This study aims to assess the impacts of the strain of Rhizobium on the nodulation, growth, nitrogen (N2) fixation rate and ion accumulation within Phaseolus vulgaris L. under salt stress. Methods: The Coco Blanc cultivar of the common bean was inoculated with the Ar02 rhizobia strain at 15 days after germination. Bean plants were inoculated in perlite culture to which salt was added in concentrations of 0, 25, 50 and 75 mmol L-1 NaCl. Result: Inoculation with the Ar02 rhizobia strain led to infective and effective symbiosis with the common bean plants exposed to saline solutions and non-saline solutions, respectively. Nodule biomass and nitrogen content declined under salt stress but maintained a higher number of nodules and nodule biomass at 75 mM NaCl. Plant root and shoot length increased with higher biomass under saline conditions, significantly more than the non-inoculated plant without salt. However, the progressive addition of NaCl reduced the growth of the root and shoot and the biomass within the inoculated plant. Salinity led to increased Na+ within the plant's shoot, along with a reduction in Ca+2 and K+ concentrations. The shoot's Ca+2, Na+ and K+ content were higher in the inoculated plant than the noninoculated. The salt tolerance in common bean plants inoculated with Ar02 rhizobia was linked with the plant's capability to sustain nodulation and enhance Na+ concentration in the shoot. Furthermore, salt tolerance within the same variety inoculated with Rhizobium was linked to a decline in the Ca+ and K+ concentrations in the shoot region of salt-exposed plants. [ABSTRACT FROM AUTHOR]

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

Haloxylon ammodendron and Nitraria roborowskii Kom are dominant groups characterised in Qaidam Basin. Elucidating the salt-tolerant mechanism of these two plants, which can grow successfully in this desert area affected by salinity and alkalinity, contributes to the protection and restoration of local vegetation. In this paper, seed germination feature responses in saline-alkali conditions were tested. H. ammodendron seeds retained 72% of germination percentage (GP) under high salinity up to 500 mmol L−1 saline solution and other germination parameters showed a significant decrease under increasing salinity without alkaline stress (P < 0.05). GP of N. roborowskii Kom was significantly accelerated from 0 to 200 mmol L−1 saline solution (P < 0.05), while other germination parameters were significantly accelerated from 0 to 100 mmol L−1 saline solution without alkaline stress (P < 0.05). Germination parameters of H. ammodendron under low concentration (concentration < 300 mmol L−1) alkali stress (pH < 8.78) were accelerated than non-alkali stress. Germination parameters of N. roborowskii Kom seeds were significantly inhibited under alkali stress (P < 0.05); moreover, the facilitation of low salinity was diminished by alkali stress (P < 0.05). The regression models of germination parameters and salinity under different pH values presented cubic curves, quadratic curves, and linear model and all models were significant (P < 0.05) in both plants. [ABSTRACT FROM AUTHOR]

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

The interface transmissivity (θ) of two multicomponent geosynthetic clay liners (GCLs) is investigated upon hydration and permeation with a highly saline solution (TDS ≈ 260,000 mg/l; Na+ ~ 95,000 mg/l; K+~12,000 mg/l) at two stress levels (10 kPa and 150 kPa). One GCL had a smooth 0.2 mm-thick coating whereas the second GCL had a textured 1 mm-thick coating. For both GCLs, the interface transmissivity after 2-weeks is shown to be higher than at steady-state. The lower the geomembrane's (GMB) stiffness, the lower interface transmissivity. However, the effect is generally diminished at steady state and higher stress. The effect of GMB stiffness at 10 kPa is shown to be 1.6-times that at 150 kPa. Similarly, the 2-week and steady state interface transmissivity for the textured GMB was higher at 10 kPa than at 150 kPa. Coating texture and coating orientation are shown to have a significant effect on GMB/multicomponent GCL interface transmissivity. A hole in the coating aligned with GMB hole creates an additional flow path at the coating/GCL interface (θ Geofilm/GCL), however most of the flow occurs at the coating/GMB interface (θ Geofilm/GMB). [ABSTRACT FROM AUTHOR]

Mandacaru (Cereus jamacaru DC.) is a cactus widely found in the Caatinga, with its seeds usually subjected to adverse conditions. Therefore, the objective of this study was to evaluate the effect of water restriction on germination and vigor of mandacaru seeds by using different salts and osmotic potentials. To that end, we used saline solutions of NaCl, KCl, CaCl2 and MgCl2 prepared at the osmotic potentials of 0.0; -0.2; -0.4; -0.6; -0.8; -1.0 and -1.2 MPa. Four replicates of 50 seeds per treatment were used, distributed in "gerbox" boxes between blotter paper and under temperature of 25 °C. Counts of the number of germinated seeds were performed daily for 21 days after root protrusion. The variables analyzed were the following: water content (%), germination (%), mean germination time and normal seedlings (%). A completely randomized following the factorial scheme 4 × 7 (salts × osmotic potentials) was employed. Results obtained suggest that mandacaru seeds show the ability to germinate in saline soils, a characteristic found in arid and semi-arid areas. Decreased osmotic potential promoted reductions in germination (%) and vigor of Cereus jamacaru DC seeds. The MgCl2 salt was the one that most negatively affected the germination and initial seedling development. [ABSTRACT FROM AUTHOR]

The study was conducted to investigate the impact of Ca(NO3)2 on different levels of salt-stress in date palm. Three-years-old date palm plants were subjected to four NaCl levels: 50, 100, 150 and 200 mM. The saline solutions were supplemented with 0, 5, 10 and 20 mM Ca(NO3)2. The combined NaCl/Ca(NO3)2 treatments were conducted over a period of 10 weeks. Control plants were only subjected to the four salinity levels with no Ca (NO3)2 addition. Results showed an inhibitory effect of salinity on almost all plants' parameters under investigation, mainly the accumulation of ions such as N, K, Ca, plant dry weight, chlorophyll and net photosynthesis rate. Addition of Ca (NO3)2 in the solution was more beneficial when added in a moderate concentration (10 mM) compared to lower (5 mM) and higher (20 mM) under all salinity levels. The addition of 10 mM Ca (NO3)2 noticeably enhanced chlorophyll content under 50 mM Na Cl (2.5 mg/100 cm²) and 150 mM NaCl (2 mg/100 cm²). In addition, 10 mM Ca (NO3)2 reduced the accumulation of Na and Cl in plant parts. For instance, in trees subjected to 10 mM Ca (NO3)2, Cl content in leaves and stems under 50 mM Na Cl were 0.23% and 0.65%, respectively. On the other hand, Cl content under 100 mM Na Cl and 200 mM Na Cl were lower compared to their corresponding control treatments. It seems that the use of Ca (NO3)2 had ameliorative effects on salt-stressed date palm plants when used with moderate concentrations. [ABSTRACT FROM AUTHOR]

The study was conducted to evaluate the effect of lead (Pb) stress alone or in combination with salinity on the anatomical structure of roots and leaves of Date palm seedlings. Pb was added to soil at 100, 300 and 600 mg/kg concentrations as a pure aqueous solution or mixed with saline solution at 200 mM. Compared with the control, the microscopic study of root tissues showed that all treatments caused a significant increase in the thickness of epidermis, endodermis and pericycle, whereas the cortex thickness and diameters of the vascular cylinder, protoxylem and metaxylem decreased significantly. However, only the phloem diameter was affected significantly by 600 mg/kg Pb with or without salinity. Compared with the control, results on leaf tissues revealed that treatment with 300 and 600 mg/kg Pb alone or in combination with salinity led to a significant increase in the thickness of cuticle layer, upper epidermis and lower epidermis. Results also showed a significant increase in the diameter of tannin and palisade cells when treated with 100 mg/kg Pb with or without salinity. Small vascular bundle diameter decreased significantly in seedlings exposed to Pb at all examined concentrations with or without salinity. [ABSTRACT FROM AUTHOR]

The effects of high saline concentrations on the plasma osmolytes of the four populations of the Pacific Treefrog, Pseudacris regilla, were investigated. Two of the populations, Chris Wicht and Trabuco Canyon, were in fresh water environments and two populations, Newport Back Bay and Alkaline Marsh, were in brackish water environments. The Newport Backbay treefrogs were most tolerant of increased sodium chloride solutions with 11 of 15 individuals surviving at 240 mM sodium chloride at 72 hrs. The Trabuco Canyon population was the least tolerant with 10 of 15 specimens surviving 120 mM sodium chloride at 72 hrs but none at the 180 mM concentration at 72 hrs. The Chris Wicht and Alkaline Marsh treefrogs were intermediate in their survival times with frogs surviving in 180 mM saline solutions at 72 hrs. The Newport treefrogs appeared to be the most efficient in osmoregulating by mainstreaming the plasma sodium and increasing plasma urea to compensate for the osmotic gradient produced by the increased external saline concentrations. The Trabuco Canyon and the Chris Wicht treefrogs appeared to be intermediate in their osmoregulatory abilities with the Alkaline Marsh treefrogs being least efficient and more likely an osmoconformer. The difference in osmoregulatory responses appears to be a population difference and a function of habitat. Sodium chloride was the major plasma osmolyte in the four populations of treefrogs. Urea increased in importance as the external concentration of the saline media increased, thus the role of urea was significant in maintaining the internal osmoconcentration. These simple physiological mechanisms allow this widespread treefrog to occur in so many different habitats. [ABSTRACT FROM AUTHOR]

More than half of residential water in Utah is used for landscape irrigation. Reclaimed water has been used to irrigate urban landscapes to conserve municipal water. High salt levels in reclaimed water may pose osmotic stress and ion toxicity to saltsensitive plants. Viburnums are commonly used landscape plants, but salinity tolerance of species and cultivars is unclear. The objective of this study was to characterize gas exchanges and mineral nutrition responses of 12 viburnum taxa subjected to salinity stress in a greenhouse study. Plants were irrigated with a nutrient solution at an electrical conductivity (EC) of 1.3 dS·m-1 or saline solution at an EC of 5.0 dS·m-1 or 10.0 dS·m-1. The net photosynthesis rate (Pn), stomatal conductance (gS), and transpiration rate (E) of all viburnum taxa, except for Viburnum 3burkwoodii and V. 3'NCVX1', decreased to various degrees with increasing salinity levels. The Pn, gS, and E of V.3burkwoodii and V. 3'NCVX1' were unaffected by saline solutions of 5.0 dS·m-1 at the 4th and 9th week after treatment initiation, with the exception of the Pn of V. 3burkwoodii, which decreased at the 9th week. Leaf sodium (Na+) and chloride (Cl-) concentrations of all viburnum taxa increased as salinity levels increased. Viburnum 3burkwoodii had relatively low leaf Na+ and Cl- when irrigated with saline solutions of 10.0 dS·m-1. Plant growth and gas exchange parameters, including visual score, plant height, Pn, gS, E, and water use efficiency (WUE) correlated negatively with leaf Na+ and Cl- concentrations. The ratio of potassium (K+) to Na+ (K+/Na+) and ratio of calcium (Ca2+) to Na+ (Ca2+/Na+) decreased when salinity levels increased. Visual score, plant height, Pn, gS, E, and WUE correlated positively with the K+/Na+ and Ca2+/Na+ ratios. These results suggest excessive Na+ and Cl- accumulation inhibited plant photosynthesis and growth, and affected K+ and Ca2+ uptake negatively. [ABSTRACT FROM AUTHOR]

In this study, salt tolerance during germination of Aeluropus lagopoides (L.) Trin. was tested using fresh seeds collected from three different maternal habitats under three thermoperiods and two light regimes. Additionally, we tested the ability of non-germinated seeds that had been exposed to different concentrations of NaCl to recover their germination in distilled water. The results showed a significant effect of seed source, temperature, and salinity, and some of their two- and three-way interactions on final germination and recovery percentage. The seeds from non-saline provenances had the highest percentages for germination (ca. 79%) under the 35/25 °C temperature regime, whereas the lowest percentages for germination (ca. 21%) was recorded for seeds from saline conditions under the 25/15 °C treatment. Additionally, percent germination was significantly lower for the seeds incubated in the saline solutions (100, 200, 400, and 600 mmol/L NaCl) and germinated under colder conditions (15/25 °C), compared with the seeds incubated in non-saline solutions (control group, 0 mmol/L NaCl) and germinated under warmer conditions (35/25 °C). The highest recovery percentage was recorded for seeds of the hyper-saline habitat incubated at 35/25 °C. Thus, seeds maintained their viability despite experiencing a range of saline conditions and were able to germinate upon the arrival of suitable conditions, which can be an adaptation to its saline arid desert habitat. [ABSTRACT FROM AUTHOR]

Water scarcity in the world is a problem diagnosed especially in countries with large semi-arid regions such as Brazil. Research has been conducted with a view to making use of saline waters as an input for cultivation, particularly in hydroponics, with especial focus on lettuce, the most prominent leafy vegetable in Brazil. The objective of this study was to evaluate the development of lettuce in a semi-hydroponic system fertigated with saline water and under foliar fertilization with biofertilizer. The present study was carried out in a greenhouse located in the experimental area of the Department of Environmental and Technological Sciences (DCAT) of the Federal Rural University of the Semi-Arid Region, in the municipality of Mossoró, RN, Brazil. The experimental design was a randomized complete block design, with treatments arranged in a 2 x 4 factorial scheme, with 4 replicates, two salinity levels of the water used to prepare the nutrient solution (0.5 and 3.5 dS m-1) and four biofertilizer concentrations (0, 20, 40 and 60%) applied by foliar spraying. The evaluated characteristics were: shoot diameter, stem diameter, number of leaves, fresh mass, dry mass, leaf succulence, leaf area and specific leaf area. The use of saline water to prepare the nutrient solution reduces fresh mass and dry mass production in the lettuce crop. The biofertilizer can be applied through the leaves at concentration of up to 20%, promoting greater plant growth. [ABSTRACT FROM AUTHOR]

Salt stress affects the development and growth of plants in various ways as a result of its effect on water relationships, photosynthesis, and nutrient absorption by physiological and biochemical processes. Consequently, several researchers have increasingly studied the effect of plant growth promoting bacteria (PGPR) as promoters and enhancers under saline environment. The main goals of this study were to examine the manifested response of the broad bean plant under saline conditions and to evaluate the role of some Pseudomonas isolates in improving plant tolerance to salt stress. Three Pseudomonas strains were isolated (P1 and P7 from a saline soil and P15 from a vineyard soil). These isolates were screened by salinity and used as inoculums in Vicia faba plants (OTONO variety) irrigated with two saline solutions (NaCl; 100 and 150 mM L-1) and one without salinity. The results show that salinity decreased the fresh weight, total chlorophyll content, and the Na+/K+ ratio, but it increased proline accumulation in inoculated and noninoculated plants. The inoculation of V. faba plants with P1, P7, and P15 strains significantly increased the production of fresh biomass in the presence and absence of salt stress, and positively affected the accumulation of proline and the Na+/K+ ratio. The inoculation with bacterial strains increased the total chlorophyll content in plants at all salt treatment levels, especially the P1 strain that showed a significant effect. [ABSTRACT FROM AUTHOR]

The interface transmissivity (θ) and hydraulic conductivity (k) are measured for two geosynthetic clay liners (GCLs), one with polymer-enhanced bentonite, when hydrated and permeated with saline (brine) solutions at three different concentrations and Reverse Osmosis (RO) water. Two interface transmissivity values are reported, the 2-week (θ2-week) and the steady-state (θsteady-state) interface transmissivity. For saline solution (brine) permeation, the 2-week interface transmissivity (θ2-week) is one to two orders of magnitude higher than the steady-state values. In addition, the steady-state interface transmissivity (θsteady-state) with respect to brine is almost an order of magnitude higher than that for RO water permeation. Geomembrane (GMB) stiffness has a limited effect on interface transmissivity at 150 kPa, whereas at 10 kPa the interface transmissivity decreases as the GMB stiffness decreases. GMB texture has only a small effect on interface transmissivity at different stress levels. Water prehydration reduces the effect of brine permeation on interface transmissivity and hydraulic conductivity, especially at 150 kPa. Transmissivity tends to increase as the salt concentration increases but the effect was significant at all concentrations considered (440 to 4400 mmol/l). While the effect of bentonite enhancement on interface transmissivity is unclear, the hydraulic conductivity (k) is generally lower for enhanced bentonite. [ABSTRACT FROM AUTHOR]

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

One of the unique properties of earlier stages of plant growth is germination. Germination is morphological expression of various metabolic activities in seeds. Plants exposure to the abiotic stresses for instance salinity that influence physiological processes, anatomy, developmental systems and plant development. Agriculture production under arid and semi-arid zone is low owning to many factors for example accumulation of salts in soils and water, total of land area under salinity is about 953 million ha. The aim of this research was to evaluate the germination characters of five faba bean (Vicia faba L.) varieties [Nubaria (1), Giza (843), Sakha (1), Sakha (3) and, Sakha (4)] were using saline solution containing (0, 1000 and 2000 ppm NaCl), were utilized to examine their water uptake, germination percentage, germination index, relative salt injury rate, radicle length, sprout fresh and dry weight, weight losses and seed volume using saline solution. Results indicated that the higher concentrations of salt have a negative impact on water uptake, germination percentage, radical length, sprout fresh and dry weight, seed volume, and relative salt injury rate. At all salinity concentrations, all varieties showed different degrees of salt tolerance. Sakha (3), (4) and Giza (843) had a better salt tolerance index than the others. Nubaria (1) and Sakha (1). Nubaria (1), Giza (843) had the highest percentage and index of germination, while Sakha (1) had the shorter radical length and susceptible to salt injury rate. Moreover, Giza (843) and Sakha (3) genotypes can be considered as tolerant to salt stress compared to the other ones. These genotypes also could be used in the breeding program for enhancing faba bean cultivation in newly reclaimed lands. Data suggest a test of seed germination may be useful to use in developing new lines of faba bean to grow in saline soils. [ABSTRACT FROM AUTHOR]

To avoid structural changes within nanofiltration membranes during operation, pre-compaction of filtration membranes is usually performed. However, even after pre-compaction, the NF270 membrane has previously been shown to display a level of pressure susceptibility in pure water systems, particularly evident at low pressures. For the first time, this study provides experimental evidence for the effect of salinity on the pressure susceptibility of the NF270 membrane. Permeability was shown to decrease with increasing salinity up to 189 mM MgSO 4 , with the largest reduction (22 %) observed at the lowest MgSO 4 concentration (31.49 mM MgSO 4). A significant reduction (35 %) in the membrane susceptibility was also observed following the introduction of MgSO 4 to a concentration of 31.49 mM. A mathematical expression, developed for pure water systems, was modified to account for salinity effects and fitted the experimental data well for concentrations up to 0.2 M. These results are explained by compaction of the membrane polymer, due to either charge neutralisation at the membrane surface, or electric double layer compression, or both. However, further increases in salinity had no significant effect on membrane susceptibility, suggesting that salt induced membrane compaction occurs at very low concentrations. [Display omitted] • NF270 membranes were shown to have a susceptibility to pressure in pure water. • A novel pressure-flux expression was derived for elastic membranes in saline solution. • For the first time, the effect of salinity on membrane susceptibly to pressure was quantified. • Salinity caused membrane deswelling in NF270 significantly reducing permeability. • NF270 membranes susceptibility to pressure was reduced in saline solution. [ABSTRACT FROM AUTHOR]

We evaluated the salinity reduction of the experimental saline solutions through ion uptake capacity of two plant species, purslane (PU) (Portulaca oleraceae) and water hyacinth (WH) (Eichhornia crassipes). These species were grown in experimental hydroponic units simulating a floating system. The hydroponic system contained treatments with three nutrient solutions identified as A1, A2, and A3 composed of fixed concentrations of macro and micronutrients to which three different concentrations of sodium chloride had been added. After the experimental period, physicochemical and volume changes in the saline nutrient solutions were evaluated. The relative growth rate results were similar for both plant species, but with lower consumption of hydroponic nutrient solutions by PU. Despite higher solution volume loss, regardless of the nutrient solution applied, WH had greater weekly estimated potential of reduction of macronutrients (calcium and magnesium; >50%); however, PU showed the best weekly potential reduction of sodium (36%) with solution A2. Therefore, both plants present potential to be used for salinity reduction in the natural conditions. [ABSTRACT FROM AUTHOR]

Saline stress is recognized as one of the most important abiotic stresses for plants in some regions of the world. Recent studies showed that silicon (Si) can play an important role in plant resistance to environmental conditions, such as excessive salinity. In the present experiment, Sinapis nigra L. was exposed to two levels of salinity (50 and 100 mM NaCl). To study the effect of Si addition on the concentrations of K+, Ca2+, Na+, and P, in the vegetative parts of plants, 5 mM of Si in the form of fertilizer (Siliplant) was added to the nutrient solutions. The experiment was conducted in semi-controlled conditions. The results showed that both salinity levels significantly increased the concentration of Na+ in leaves, stems, and roots, whereas the concentration of Ca2+ and K+ were decreased (up to 55% and 90% in the presence of 100 mM NaCl). The addition of Siliplant to the saline nutrient solution (50 mM NaCl) was efficient in decreasing Na+ accumulation in leaves and stem, while in roots more alleviating effect of Si addition was pronounced in the presence of 100 mM NaCl (Na+ concentration decreased by 50%). The presence of Si in 50 mM NaCl containing nutrient solution enhanced the accumulation of K+ in leaves and stems, while Ca2+ concentration was decreased, or the addition of Si to a nutrient solution had a negligible effect. Based on the results of the present study, the application of Si in the form of fertilizer was found more efficient in the presence of lower salt concentration (50 mM NaCl). Therefore, higher doses of the fertilizer should be considered and tested in case of higher NaCl concentrations in the substrate. [ABSTRACT FROM AUTHOR]

The development and yield of plants is directly related to the effects of salinity. There are several reports in scientific studies of significant reduction in the growth and production of tomato in soils with high electrical conductivity. The correction or recovery of salinized soils, although technically possible, is a slow and very expensive process, making it necessary to develop new technologies. The objective of this study is to evaluate the production of tomato (Solanum lycopersicon L.) seedlings using seeds pelleted with a homeopathic preparation of Natrum muriaticum (Nat-m) submitted to saline stress. The treatments consisted of the pelletization of tomato seeds with six dynamizations of Nat-m (3cH, 5cH, 7cH, 9cH, 11cH and 13cH). Coated or uncoated seeds (controls) were placed in phenolic foam blocks, kept in plastic trays previously moistened with 50 mM NaCl saline solution (2.922 g.L-1 of NaCl, electrical conductivity = 4.5 dSm-1) and nutrient solution (0.15 dS.m-1) at half the ionic strength, containing 4, 1, 2, 1, 0.5, and 0.5 mmol.L-1 of N, P, K, Ca, Mg and S, and 17.5, 9.5, 10.5, 2, 0.45 and 0.35 mmol.L-1 of Fe, Mn, Zn, Cu and Mo, respectively. The variables evaluated were percentage of emerged plants, emergence speed index, shoot length, leaf area, number of leaves, root volume, root dry matter, and shoot dry matter. The treatments pelleted seeds/talc Nat-m 5cH and pelleted seeds/talc Nat-m 7cH increased all variables evaluated. They differed statistically from the controls, with a positive response for the development of tomato seedlings under disequilibrium conditions. [ABSTRACT FROM AUTHOR]

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

Abstract The phase equilibria of H 2 O CO 2 NaCl systems is of general interest to many scientific disciplines and technical fields. One aspect is the CO 2 -mediated corrosion of oil country tubular goods in deep saline aquifers. In this study, CO 2 solubility experiments were conducted in simulated oil and gas well environments using a novel experimental apparatus and method. The solubility of CO 2 in deionised water and NaCl solutions was measured at temperatures of 303.15–363.15 K and pressures of 50–250 bar. The impacts of temperature, pressure and salinity on CO 2 solubility are analysed quantitatively and qualitatively and are consistent with published data. CO 2 solubility increases with pressure in all cases, and pressure inhibits the effect of temperature on CO 2 solubility to some extent. An interesting phenomenon is that CO 2 solubility increases with pressure much faster at low pressures than at high ones. A transition pressure of 150 bar was determined at medium-low temperature and low salinity. Highlights • Test equipment and method of CO 2 solubility in wellbore environments are presented. • Tests of CO 2 solubility in three solutions are conducted at 303.15–363.15 K and 50–250 bar. • Correlations between CO 2 solubility and factors (T-P NaCl) are obtained. [ABSTRACT FROM AUTHOR]

A laboratory experiment investigates the influence of salinity on the characteristics of bubble clouds in varying saline solutions. Bubble clouds were generated with a water jet. Salinity, surface tension, and water temperature were monitored. Measured bubble cloud parameters include the number of bubbles, the void fraction, the penetration depth, and the cloud shape. The number of large (above 0.5 mm diameter) bubbles within a cloud increases by a factor of three from fresh to saline water of 20 psu (practical salinity units), and attains a maximum value for salinity of 12-25 psu. The void fraction also has maximum value in the range 12-25 psu. The results thus show that both the number of bubbles and the void fraction vary nonmonotonically with increasing salinity. The lateral shape of the bubble cloud does not change with increasing salinity; however, the lowest point of the cloud penetrates deeper as smaller bubbles are generated. [ABSTRACT FROM AUTHOR]

Fly ash from solid waste incineration plants is a source of a significant mass flow of Zn- and Pb-containing waste. Acidic leaching removes most heavy metals from fly ash, but leads to high concentrations of soluble salts in the solution, resulting in a saline solution enriched in heavy metals. Common treatment methods cause voluminous sludge that is mostly disposed of as hazardous waste and hence leads to a loss of Zn and other heavy metals. On a laboratory scale, precipitation experiments with 2000 mg/L Zn were performed to investigate the impact of salinity (0 to >70,000 mg/L Cl, 0 to 5400 mg/L SO4) and Pb concentration (0 to 800 mg/L) on the formation of mineral phases. The removal efficiency of Zn and Pb after alkalization of the solution was studied. Characterization of the precipitates showed that salinity has a significant impact on the phases produced. At a low salt concentration, zincite (ZnO) is formed. With increasing salinity, the higher concentration of chloride and sulfate increases the stability of various Zn sulphate hydroxides. At a medium salinity of 7000 mg/L, bechererite is predominantly formed, whereas a higher salinity leads to the formation of gordaite. Addition of low amounts of Pb enlarges the stability field of zincite to medium saline solutions but causes lower removal efficiency. The lower removal efficiency observed at low salinity increases at a higher salinity. In high saline solutions, high Pb concentrations (800 mg/L) are needed to form laurionite, a Pb-hydroxychloride phase. [ABSTRACT FROM AUTHOR]

Layer-by-layer (LBL) assembly is an essential method for the preparation of nanofiltration (NF) membranes, offering tunable charge and pore size, high water permeability, and good anti-fouling properties, making them highly suitable for resource recovery, seawater desalination, and other fields. Despite their advantages, LBL NF membranes suffer from salinity instability, limiting their use in highly saline streams. This perspective review provides a summary of the fundamental physical and chemical principles of LBL assembly related to the salinity stability of LBL NF membranes. We critically analyze the driving force of LBL assembly, the binding strength of polyelectrolyte (PE) pairs, and the overcompensation of LBL membranes. We also discuss the factors affecting overcompensation level with respect to two different time scales. Furthermore, we examine the relationship between overcompensation level and salinity stability of LBL membranes, considering physical (osmotic pressure) and chemical (Le Chatelier's principle) aspects. Our analysis demonstrates that the salinity stability of LBL NF membranes in highly saline solutions can be improved by selecting PEs with stronger binding strength, increasing the overcompensation level, and chemical crosslinking. These methods not only enhance the salinity stability of LBL NF membranes but also offer greater potential for their future application in highly saline streams. • The fundamental understanding of salinity stability for LBL assembly is reviewed. • Osmotic pressure and Le Chatelier's principle clarify the relation of overcompensation and salinity stability. • The methods to enhance the salinity stability of LBL NF membranes are proposed. [ABSTRACT FROM AUTHOR]

An empirical model is developed to predict the dissolution rate of calcite in saline solutions that are saturated with respect to dissolved $$\hbox {CO}_2$$ over a broad range of both subcritical and supercritical conditions. The focus is on determining the rate of calcite dissolution within a temperature range of 50-100 $$^\circ \hbox {C}$$ and pressures up to 600 bar, relevant for $$\hbox {CO}_2$$ sequestration in saline aquifers. A general reaction kinetic model is used that is based on the extension of the standard Arrhenius equation with an added, solubility-dependent, pH term to account for the saturated concentration of dissolved $$\hbox {CO}_2$$ . On the basis of this kinetic model, a new rate equation is obtained using multi-parameter, nonlinear regression of experimental data to determine the dissolution of calcite as a function of temperature, pressure and salinity. Different models for the activity coefficient of $$\hbox {CO}_2$$ dissolved in saline solutions are accounted for. The new rate equation helps us obtain good agreement with experimental data, and it is applied to study the geochemically induced alterations of fracture geometry due to calcite dissolution. [ABSTRACT FROM AUTHOR]

Adsorption ability of prepared magnetic nanoparticles supported on activated carbon (AC-MNPs) was evaluated to synthesize an efficient and a low cost adsorbent for removal of Pb(II) and Cr(VI) ions from single and binary component aqueous solutions in the presence of salinity. Magnetic adsorbent was prepared by co-precipitation over activated carbon derived from almond shell by physical activation method. AC-MNPs was modified by oxygen containing functional groups to enhance the adsorption capacity of adsorbent. XRD, XPS, BET, Boehm, TEM, FT-IR, DLS and XRF were used to characterize the AC@Fe 3 O 4 @SiO 2 -NH 2 -COOH. Characterization analyses indicated the high dispersion of Fe 3 O 4 crystallites on the activated carbon. TEM, XRD and DLS results revealed that size of Fe 3 O 4 crystallites were below 17 nm. XPS results of the adsorbents before and after Pb(II) and Cr(VI) ions adsorption indicated that these metal ions successfully adsorbed. There were found from operating experiments that Cr(VI) ions have a negligible effect on adsorption of Pb(II) ions in binary solutions. However, removal efficiency of metal ions was reduced which were reached 80% and 53% for Pb(II) and Cr(VI), respectively. Results also illustrated that the effect of salinity on the adsorption of metal ions at pH > 7 was negligible. [ABSTRACT FROM AUTHOR]