Ion exchange treatment of saline solutions using lanxess S108H strong acid cation resin

Common to many types of water and wastewater is the presence of sodium ions which can be removed by desalination technologies, such as reverse osmosis and ion exchange. The focus of this investigation was ion exchange as it potentially offered several advantages compared to competing methods. The equilibrium and column behaviour of a strong acid cation (SAC) resin was examined for the removal of sodium ions from aqueous sodium chloride solutions of varying normality as well as a coal seam gas water sample. The influence of the bottle-point method to generate the sorption isotherms was evaluated and data interpreted with the Langmuir Vageler, Competitive Langmuir, Freundlich, and Dubinin-Astakhov models. With the constant concentration bottle point method, the predicted maximum exchange levels of sodium ions on the resin ranged from 61.7 to 67.5 g Na/kg resin. The general trend was that the lower the initial concentration of sodium ions in the solution, the lower the maximum capacity of the resin for sodium ions. In contrast, the constant mass bottle point method was found to be problematic in that the isotherm profiles may not be complete, if experimental parameters were not chosen carefully. Column studies supported the observations of the equilibrium studies, with maximum sodium loading of ca. 62.9 g Na/kg resin measured, which was in excellent agreement with the predictions of the data from the constant concentration bottle point method. Equilibria involving coal seam gas water were more complex due to the presence of sodium bicarbonate in solution, albeit the maximum loading capacity for sodium ions was in agreement with the results from the more simple sodium chloride solutions.

Saturated salt solutions for humidity control and the survival of dry powder and oil formulations of Beauveria bassiana conidia

Oil-based formulated conidia sprayed on steel plates and conidia powder (control) of Beauveria bassiana isolate IMI 386243 were stored at temperatures from 10 to 40 degrees C in desiccators over saturated salt solutions providing relative humidities from 32 to 88%, or in hermetic storage at 40 degrees C, and moisture contents in equilibrium with 33 or 77% relative humidity. The negative semi-logarithmic relation (P < 0.005) between conidia longevity (at 40 degrees C) and equilibrium relative humidity did not differ (P > 0.25) between formulated conidia and conidia powder. Despite this, certain saturated salts provided consistently greater longevity (NaCl) and others consistently shorter longevity (KCl) for formulated conidia compared to conidia powder. These results, analysis of previous data, and comparison with hermetic storage, indicate that storage of conidia over saturated salt solutions provides inconsistent responses to environment and so may be problematic for bio-pesticide research. In hermetic storage, oil formulation was not deleterious to longevity and in the more moist environment enhanced survival periods. (c) 2005 Elsevier Inc. All rights reserved.

Structure of the electrical double layer at aqueous gold and silver interfaces for saline solutions

We report the structure of the electrical double layer, determined from molecular dynamics simulations, for a range of saline solutions (NaCl, KCl, MgCl2 and CaCl2) at both 0.16 and 0.60molkg(-1) on different facets of the gold and silver aqueous interfaces. We consider the Au/Ag(111), native Au/Ag(100) and reconstructed Au(100)(5×1) facets. For a given combination of metallic surface and facet, some variations in density profile are apparent across the different cations in solution, with the corresponding chloride counterion profiles remaining broadly invariant. All density profiles at the higher concentration are predicted to be very similar to their low-concentration counterparts. We find that each electrolyte responds differently to the different metallic surface and facets, particularly those of the divalent metal ions. Our findings reveal marked differences in density profiles between facets for a given metallic interface for both Mg(2+) and Ca(2+), with Na(+) and K(+) showing much less distinction. Mg(2+) was the only ion for which we find evidence of materials-dependent differences in interfacial solution structuring between the Ag and Au.

RHEOLOGICAL CHARACTERIZATION of SUSPENSIONS of SUCROSE CRYSTALS IN SATURATED SUCROSE SOLUTIONS

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Alternative saline solutions to float foraminiferal tests

Flotation has been widely used in studies of recent foraminifera in order to concentrate tests and save time during picking. In this paper, four flotation agents with different densities were compared: (1) trichloroethylene, TCE (C2HCl3), with a density of 1.46 g mL(-1); (2) sodium nitrate/sodium thiosulfate solution, SNT (NaNO3 + Na2O3S2 center dot 5H(2)O), with a density of 1.46 g mL(-1); (3) zinc chloride Solution, ZC (ZHCl(2)), with a density of 1.70 g mL(-1); and (4) sodium polytungstate solution, SPT (3Na(2)WO(4) center dot 9WO(3) center dot 5H(2)O), with a density of 2.50 g mL(-1). Comparison was carried out by means of qualitative and quantitative data. Results showed that ZC and SPT were the best flotation agents, recovering 91% and 96% of the total tests, respectively, whereas TCE and SNT recovered 59.1% and 72.8%, respectively. Both quantitative and qualitative results significantly improved with a higher density of the flotation liquid. Therefore, substitution of TCE with ZC or SPT solutions is strongly encouraged, because they are, additionally, less harmful to health and the environment. ZC is the most cost-effective, since its results were not significantly different from those of the SPT treatment. Carbon tetrachloride (CCl4) was not considered in this comparative study, because it has been banned in many countries and it is highly harmful to health and the environment.

Variations in peak nasal inspiratory flow among healthy students after using saline solutions

Nasal hygiene with saline solutions has been shown to relieve congestion, reduce the thickening of the mucus and keep nasal cavity clean and moist. Evaluating whether saline solutions improve nasal inspiratory flow among healthy children. Students between 8 and 11 years of age underwent 6 procedures with saline solutions at different concentrations. The peak nasal inspiratory flow was measured before and 30min after each procedure. Statistical analysis was performed by means of t test, analysis of variance, and Tukey's test, considering p<0.05. We evaluated 124 children at all stages. There were differences on the way a same concentration was used. There was no difference between 0.9% saline solution and 3% saline solution by using a syringe. The 3% saline solution had higher averages of peak nasal inspiratory flow, but it was not significantly higher than the 0.9% saline solution. It is important to offer various options to patients.

Recovery of uranium from saline solutions by biological slimes : final report /

"October 1, 1955."

Experimental researches on the specific gravity and the displacement of some saline solutions,

Reprinted from the Transactions of the Royal society of Edinburgh, vol. XLIX, part I, 1912.

Bases fisiológicas para a conservação a longo prazo de sementes Cariniana legalis (Mart.) O. Kuntze

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Are we getting accurate measurements of Ksat for sodic clay soils?

In this paper we discuss the use of a series of column experiments to improve understanding of the effect irrigation water chemistry (saline solutions) has on measurements of saturated hydraulic conductivity (Ksat) of a sodic clay soil. We highlight in particular the use of extended leaching periods to determine whether the duration of leaching affects the results. In the experiments, mixed cation solutions of two different salinity levels, 50 meq/L and 100 meq/L, were applied under constant head to columns of a repacked sodic clay soil using three replicates for each treatment. The maximum Ksat measured during leaching with the 100 meq/L solution was approximately double the maximum Ksat measured during leaching with the 50 meq/L solution. Measured flow rates were found to increase rapidly after flow commenced then decrease gradually until flow rates became stable. The final, stable flow rate was roughly 80% less than the maximum flow rate measured. Reasons for these changes in saturated hydraulic conductivity are discussed. The key finding from these experiments is that long term leaching, involving significantly more pore volumes than is commonly reported in the literature, is required to obtain a ‘stable’ Ksat. We recommend that further studies be carried out to (1) determine whether similar behaviour in Ksat occurs in a wide range of sodic clay soils and (2) to help build a better understanding of the causes and implications of the observed behaviour in Ksat.

Smear layer removal capacity of disinfectant solutions used with and without EDTA for the irrigation of canals: a SEM study.

The purpose of this study was to carry out a scanning electron microscopic (SEM) analysis of the cleaning qualities and smear layer removal from root canal walls, instrumented and irrigated with 2.5% NaOCl, 2.0% chlorhexidine and saline solutions. Fifty extracted teeth were used in this study. All teeth were radiographed to determine the existence of a single canal. The crowns were cut at the cervical limit and the root canals were instrumented with K-type files up to size 45. During root canal preparation, irrigations were made with the different solutions being evaluated: Group 1: 2.5% NaOCl (10 roots); Group 2: 2.5% NaOCl and 17% EDTA for 2 minute (10 roots); Group 3: 2.0% chlorhexidine (10 roots); Group 4: 2.0% chlorhexidine and 17% EDTA for 2 minutes (10 roots); Group 5: saline solution (5 roots); Group 6: saline solution and 17% EDTA for 2 minutes (5 roots). After instrumentation, the canals were irrigated with each one of the solutions and the roots were cut in the buccolingual direction for SEM analysis, at the cervical, middle and apical thirds, to ascertain the presence or absence of smear layer and debris. SEM analysis was performed by three calibrated examiners and scores were submitted to Kruskal-Wallis test at the significance level of p = 5%. Results showed that the use of 17% EDTA decreased the smear layer significantly (p < 0.05) for all evaluated solutions in all thirds. When EDTA was not used, a significantly higher quantity of smear layer on the apical third was observed only in the NaOCl groups. The use of 17% EDTA was significant for debris removal except for the chlorhexidine groups. The following conclusion could be drawn: the use of 17% EDTA was necessary to enhance cleanness of the root canals.

Proton flux across artificial vesicle bilayers

The study of proton conductance across artificial membranes has revealed a surprisingly high permeability for H+, (Pnet H+). A high Pnet H+ is difficult to reconcile with the biological requirement for the maintenance of pH gradients across the plasma membranes of cells, organellar study was undertaken to examine the role played by cholesterol and phospholipid fatty acid side chain composition in determining how well a membrane will function as a barrier to acid. The effects of counter-ion movement on acidification rates were examined in order to interpret the data obtained from variations in membrane composition. In phosphate buffered saline solutions, vesicle membranes composed of unsaturated fatty acid phosphatidylcholines proved to be poorer barriers to acid than membranes composed of saturated fatty acids. The barrier properties of these membranes could be ranked in the following order: DPL, (palmitic) $>$ Egg PC, (mixed chains) $>$ DLL, (linoleic), with DPL being the most effective in maintaining a one pH unit gradient near neutrality. Cholesterol decreased acidification rates of membranes made from the unsaturated phosphatidylcholines Egg PC and DLL, but enhanced acidification rates in vesicle membranes composed of the saturated phospholipid DPL. The cholesterol and fatty acid side chain effects were mediated by changes in membrane fluidity, with more rigid bilayers forming better barriers to acid. Experimental evidence was obtained which confirmed the Pnet H+ is very high relative to the permeabilities of other ions. Counter-ion controlled acidification rates depended on the size and charge of the ion which was moving in order to maintain electroneutrality. The biological relevance of a high intrinsic Pnet H+ and the possible role of counter-ion controlled acidification were discussed. ^

Desalination by a solar thermally driven distillation process

Desalination processes to remove dissolved salts from seawater or brackish water includes common industrial scale processes such as reverse osmosis, thermal processes (i.e. multi-stage flash, multiple-effect distillation) and mechanical vapour compression. These processes are very energy intensive. The Institute for Future Environments (IFE) has evaluated various alternative processes to accomplish desalination using renewable or sustainable energy sources. A new process - a solar, thermally driven distillation system . based on the principles of a solar still – has been examined. This work presents an initial evaluation of the process.

Desalination by a solar thermal membrane distillation process

A solar thermal membrane distillation pilot plant was operated for over 70 days in field conditions. The pilot plant incorporated a single spiral wound permeate gap membrane distillation style of module. All energy used to operate the unit was supplied by solar hot water collectors and photovoltaic panels. The process was able to produce a distillate stream of product water with a conductivity less than 10 µS/cm. Feed water concentration varied from 2,400 µS/cm to 106,000 µS/cm. The process is expected to find application in the production of drinking water for remote island and arid regions without the consumption of electrical energy.