Solubility Of Sulfate Research Articles

Comparative evaluation of the solubility and algal toxicity of copper sulfate and chelated copper

Concentrations of total copper in solutions of several pH values and concentrations of total alkalinity and total hardness were always higher when copper was applied as chelated copper than when copper was added in equal amounts as copper sulfate. Equilibrium calculations revealed that the increase in copper concentrations following chelated copper treatment resulted from an increase in the concentration of complexed copper; cupric ion (Cu 2+) concentration was the same with both algicides. When copper was applied to laboratory soil-water systems, copper was lost from solution slightly faster when copper sulfate was the source of copper than when chelated copper was used. Results of this study suggest that somewhat larger and more frequent doses of copper sulfate should be just as effective as chelated copper algicides.

Selective Removal of Free Dodecyl Sulfate from 2-Mercaptoethanol-SDS-Solubilized Proteins before KDS-Protein Precipitation

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the discontinuous system of Laemmli is used world-wide for analytical and preparative gel electrophoresis of polypeptides. A minor but disturbing problem is the difficulty of concentrating highly diluted solutions and determining their protein content after 2-mercaptoethanol-SDS solubilization. We describe a solution to both of these problems, detailing a two-step procedure which takes advantage of the low solubility of potassium dodecyl sulfate (KDS). Removal of excess of SDS and 2-mercaptoethanol, and concentration of proteins from even a nanomolar solution, is achieved by a two-step KDS precipitation. Free dodecyl sulfate is precipitated in step one, while KDS- proteins are pelleted in the second step, allowing the thiol agents to be discarded with the supernatant. The effects of changing [SDS] and [KCl], temperature, and pH were studied to optimize the separation of free SDS from proteins. After final precipitation, the hundred-or thousandfold concentrated proteins can be suspended in a small volume of any required medium. The procedure allows protein determination by the Lowry method, peptide mapping of 2-mercaptoethanol-SDS-solubilized polypeptides, and all other analyses which are otherwise hampered by excesses of SDS and/or thiol reagents.

Preparation, Characterization, and Dissolution Kinetics of Two Novel Albuterol Salts

The possibility of producing slowly dissolving albuterol salts was investigated as a potential means of extending the duration of action of the drug following aerosol delivery to the lung. Albuterol adipate and stearate were precipitated from alcoholic solutions of albuterol and adipic or stearic acids, respectively. Differential scanning calorimetry and hot stage microscopy showed that albuterol adipate and stearate produced single melting endotherms at 182 and 116 °C, respectively, which were distinct from those of albuterol (158 °C), adipic acid (152 °C), and stearic acid (70 °C). The aqueous solubilities of albuterol free base, sulfate, adipate, and stearate were 15.7,250,353, and 0.6 mg ⋅ mL-1, respectively, at room temperature. Only the solubilities of the adipate and the stearate increased significantly when the temperature was elevated to 37 °C (452.5 and 1.4 mg ⋅ mL-1, respectively). With a rotating disk dissolution method, albuterol free base, sulfate, and adipate were found to have intrinsic dissolution rates of 1.1, 20.4, and 24.0 mg-min-1 ⋅ cm-2, respectively, in pH 7.4 phosphate buffer at 37 °C. Albuterol stearate dissolved much more slowly and in a nonlinear fashion; this was explained by the deposition of a stearate-rich layer on the dissolving surface of the compacted salt.

Solubility of sodium chloride and sulfate in sub- and supercritical water vapor from 450–550°C and 100–250 bar

Abstract Armellini, F.J. and Tester,J.W., 1993. Solubility of sodium chloride and sulfate in sub- and supercritical water vapor from 450–550°C and 100–250 bar. Fluid Phase Equlibria, 84: 123-142. The solubility of sodium chloride in water vapor has been determined at supercritical temperatures ranging from 450–550°C and sub- and supercritical pressures varying from 100–250 bar. Measured sodium chloride concentrations ranged from 0.9–101 ppm (by weight). In the experiments, water vapor was saturated by continuously flowing it through a tube packed with solid salt. The results for sodium chloride agreed well with other studies which used continuous flow methods. Hydrolysis of the solid salt was found as a possible explanation for some of the reported discrepancies in the literature. Experiments with sodium sulfate at 500°C and 250 bar were also performed. Measured sodium sulfate concentrations were around 0.9 ppm, and exhibited unsteady behavior. Though only an estimate of Na2SO4 solubility could be obtained, this value was over two orders of magnitude lower than that for sodium chloride at identical conditions.

Hydration kinetics of calciumaluminate phases in the presence of various ratios of Ca 2+ and SO 42− ions in liquid phase

The kinetics of hydration processes of tricalcium aluminate and monocalcium aluminate in the presence of calcium sulphates and calcium hydroxide was studied at room temperature by differential calorimetry and X-ray diffraction analysis. Results indicate that the solubility of calcium sulphates (anhydrite, gypsum) and pH near the surface of calcium aluminates play an important role during hydration process. The high ratio of “basic” ions of Ca 2+ in the structure of aluminates lead to retardation of the transfer of ions into solution and enable formation of an ettringite layer on the surface.

Solubility of some lanthanide sulfates in polycomponent systems containing H2SO4

The paper presents data on the solubility of La, Ce, Pr, Nd sulfates in the polycomponent system La2(SO4)3·8H2O-Ce2(SO4)3·8H2O-Pr2(SO4)3·8H2O-Nd2(SO4)3· 8H2O-H2SO4-H2O (at 25°C and 64°C) as well as in the same polycomponent system but in the presence of CaSO4·2H2O. The solubility of the sulfates — ocathydrates of Pr at 25°C and 64°C and of La and Ce at 64°C in tricomponent systemLn2(SO4)3·8H2O-H2SO4-H2O are also reported.

Intestinal Solubility and Absorption of Ferrous Iron in Growing Rats Are Affected by Different Dietary Pectins

The effects of pectin structure on iron solubility were examined in vivo and in vitro using pectins differing in degree of esterification (DE) and molecular weight (MW). The pectins prepared differed (in DE and MW, respectively) as follows: P-A (73%, 860,000), P-B (75%, 89,000), P-C (22%, 1,260,000) and P-D (24%, 114,000). Weanling rats were trained to consume a basal diet containing ferrous sulfate as the iron source within 2 h. Food-deprived rats were presented the basal diet or the same diet containing one of the pectins at 80 g/kg diet. One hour after the meal, soluble, insoluble and tissue iron in intestinal segments and serum iron concentration in portal blood were determined and amounts of absorbed iron were calculated. Portal blood iron and calculated absorbed iron were highly correlated (r = 0.97). None of the pectins reduced iron solubility or absorption below that in rats fed the basal diet. Addition of P-B increased the amount of iron absorbed and postprandial serum iron concentration in portal blood. Solubility of ferrous sulfate in vitro was higher in solutions containing pectins than in a cornstarch solution (P < 0.05) and was also higher in diets containing pectin than in the basal diet (P < 0.05). The pectin with the high DE and low MW (P-B) improved iron solubility and absorption of solubilized iron.

Foaming in Glass Melts Produced by Sodium Sulfate Decomposition under Ramp Heating Conditions

Ramp heating a glass batch with sulfate permits determination of the foaming temperature and maximum foam height as a function of sulfate addition. Experiments revealed that, in the soda–lime glass studied, foam was produced when the mass fraction of SO3 in the glass was higher than 0.0027. With increasing sulfate content, the foaming temperature decreased and the maximum foam height increased until the mass fraction of SO3 was 0.01. Further additions of sulfate had little effect on foaming temperature and decreased maximum foam height. The results are discussed in terms of sulfate solubility and nonequilibrium effects.

Growth Kinetics of Adenine Sulphate Crystals

AbstractThe kinetics of growth and dissolution of adenine sulphate in 1.5 mol · 1−1 H2SO4 at different super‐ and undersaturations has been studied. The solubility of adenine sulphate in H2SO4 was determined over the temperature range 20–50 °C. The growth rate of the (100) face is by about 25% higher than that of (111) and the crystal habit is changed by a high supersaturation almost to a bipyramide. The surface diffusion was determined as a prevailing processes and the BaS model gives the best fit with experimental data.

Controlled cooling crystallization of ammonium sulfate in the ternary system ammonium sulfate-ammonium nitrate-water

The controlled cooling crystallization of ammonium sulfate in the ternary system: ammonium sulfate-ammonium nitrate-water considering the effect of the cooling rate was studied on the basis of the experimental nucleation and growth kinetics. For this, the solubility of ammonium sulfate in the ternary system was determined, and the maximum allowable undercooling was measured with the variations of the cooling rate and saturation temperature of the solution

Effective recovery by KCl precipitation of highly diluted muscle proteins solubilized with sodium dodecyl sulfate

A new, improved method is described, which takes advantage of the low solubility of potassium dodecyl sulfate (KDS), to concentrate sodium dodecyl sulfate-solubilized proteins from nanomolar solutions by KDS precipitation. The method was applied to proteins differing in Mr and pI. The effect of varying KCl, and the pH and/or concentration of the buffer on KDS-protein precipitation was studied. These parameters may be chosen to allow selective repartition of specific proteins in the pellet or supernatant. After precipitation, the hundred- or thousand-fold concentrated solutes are easily resuspended in small volumes of any required medium. Though initially experimented to recover muscle proteins from effluents of electroendosmotic preparative gel electrophoresis, the method proved to be of general interest as a powerful tool to recover proteins from highly diluted solutions.

Solubility of uranous sulfate in aqueous sulfuric acid solution

To provide important thermodynamic data for use in uranium hydrometallurgy, solubilities of uranous sulfate were determined as a function of free acid concentration and temperature. Two sets of experiments were performed in this study. One set was the precipitation experiments of uranous sulfate crystals, in which concentrated uranous sulfate solution was mixed with sulfuric acid solution of suitable concentration. The other set was the dissolution experiments of uranous sulfate crystals in aqueous sulfuric acid solutions. It is noteworthy that good agreement exists between the solubilities determined by the two methods. At elevated temperatures, say, 363 K, the presence of free sulfuric acid is required to avoid precipitation of uranous hydroxide resulting from the hydrolysis of uranous sulfate. Generally speaking, however, an increase in free sulfuric acid concentration results in a slight decrease in uranous sulfate solubility. The elevation of solution temperature causes a decrease in solubility of uranous sulfate. It should be noted that the solid uranous sulfates equilibrated with saturated solutions at 298 K were U(SO4)2 2H2O in dilute sulfuric acid solution and U(SO4)2 4H2O in concentrated sulfuric acid solution, while those at 333 K and 363 K were mainly U(SO4)2 4H2O.

Molten lithium nitrate-potassium nitrate eutectic: The reaction of magnesium compounds

Anhydrous and hydrated magnesium sulphate reacted as a Lux-Flood acid in molten lithium nitrate-potassium nitrate eutectic from 400 °C with precipitation of magnesium oxide. Stabilization to above 500 °C occurred with added sulphate but a lower temperature reaction took place with added sodium hydroxide. The solubility of magnesium sulphate was determined up to 400 °C and shown to be nearly an order of magnitude less than that of potassium sulphate. Magnesium nitride reacted only superficially with pure nitrate melt but reacted faster in melts containing added sodium hydroxide, magnesium oxide being the final product in both cases. In acidic melts (K 2S 2O 7 or K 2Cr 2O 7 added) reaction was complete with soluble magnesium being formed initially. Thermogravimetry of magnesium oxide in a hydroxide-containing melt suggested that magnesium hydroxide may have been an intermediate.

Solubility of Calcium Sulfate in Acidic Copper Sulfate Solutions over the Temperature Range of 298 to 333 K

Solubility of Calcium Sulfate in Acidic Copper Sulfate Solutions over the Temperature Range of 298 to 333 K

Ion interaction parameters for aluminum sulfate and application to the prediction of metal sulfate solubility in binary salt systems

The Pitzer ion interaction parameters for the Al 2 (SO 4 ) 3 −H 2 O system have been reevaluated by using all published isopiestic data at 25.0 o C. An analysis of the differences between model-calculated and experimental metal sulfate solubilities reveals that the ternary interaction parameter can be set to zero for all systems considered

Effect of Benzotriazole on the Anodic Dissolution of Iron in the Presence of Fluid Flow

The effect of benzotriazole (BTA) on repassivation of iron in was investigated under controlled hydrodynamic conditions. The presence of BTA was found to reduce the solubility of iron sulfate and thus to enhance the ability of the system to repassivate by the dissolution‐precipitation sequence. In addition, BTA was found to adsorb according to a Langmuir isotherm where the adsorption coefficient has a value, for the range of potential studied, which suggests that physical adsorption occurs. Repassivation experiments, carried out with a rotating disk system, were in agreement with theoretical predictions of flow conditions under which repassivation would, or would not, occur. It was concluded that the inhibiting action of benzotriazole in this system is caused both by adsorption, which shields a portion of the surface from experiencing the dissolution‐precipitation sequence, and by lowering the solubility of the dissolution product, which speeds repassivation of the active sites.

Heat capacity and other thermodynamic properties of Na 2SO 4(aq) in hydrothermal solutions and the solubilities of sodium sulfate minerals in the system Na-Cl-SO 4-OH-H 2O to 300°C

Heat capacities of Na 2SO 4(aq) solutions have been measured from 140°–300°C at 200 bars using a flowcalorimeter over the molality range of 0.05–1.5 mol·kg −1. Using the ion-interaction or virial coefficient approach developed by Pitzer (1973, 1979, 1987) and coworkers, and approximating the pressure-dependencies of the various Na 2SO 4(aq) thermodynamic quantities with those of NaCl(aq) calculated from the equations of Rogers and Pitzer (1982), our measured heat capacities were combined with literature values on heat capacities, enthalpies, and osmotic coefficients at temperatures to 225°C and at pressures mostly at 1 bar or vapor-saturation pressure to yield a comprehensive set of equations for the thermodynamic properties of Na 2SO 4(aq) at temperatures 25°–300°C, pressure to at least 200 bars, and molalities to 3.0 mol·kg −1. Standard state chemical potentials and activity and osmotic coefficients of Na 2SO 4(aq) derived from our model, together with standard state properties of the solids available in the literature, permit the calculation of sodium sulfate solubilities in water and in electrolyte mixtures to 300°C. Good agreement between experimental and predicted solubilities in water indicate that the ion-interaction model can be used successfully to predict mineral-solution equilibria to 300°C without an explicit accounting for ion-pairs, and demonstrates that heat capacity measurements can be used to obtain reliable high-temperature and high-pressure activity properties of electrolyte solutions. The binary and ternary mixing parameters θ ü and Ψ ük are required by the ion-interaction model for calculations for multicomponent mixtures. It was found sufficient to adopt previously determined values for θ ü at 25°C without temperature dependence and, from the solubility data, to determine temperature-dependent Ψ ük functions.

Change of solubility of potassium sulfate in water caused by traces of chromium(III)

Change of solubility of potassium sulfate in water caused by traces of chromium(III)

Aluminium sulphate solubility in acid forest soils in Denmark

Ion leaching in 3 sandy spruce forest soils of different origin and pH was investigated in the laboratory. Zero-tension lysimeters containing undisturbed soil columns of varying soil depth were subjected to H2SO4 loadings for a period of 9 weeks. The analysis of the resulting leachate supports the hypothesis that Al-sulphate minerals may form in acidic soils when exposed to acid (H2SO4) deposition. In the B horizon of a glaciofluvial sandy soil (pH 4.2), both H+ and sulphate ions were retained to maintain 2pH + PSO4 = 11.9 in the leachate solutions. This relation between H+ and sulphate activity may be due to an adsorption mechanism or a precipitation mechanism. The precipitation mechanism is favored by the good fit of leachate composition to the conditions for jurbanite [AlOHSO4] formation from gibbsite [Al(OH)3]. In the B horizon of a sandy till at pH 3.7, the Al in soil solution (0.5 mmol L−1) was leached with sulphate. As the sulphate load was increased, some sulphate was retained. This may also be due to the dissolution and precipitation of an Al-sulphate mineral. The ion activity products of leachate solutions from the B horizon of this soil were close to the pKs reported for jurbanite. The conditions for the possible existence and/or formation of Al-sulphate minerals in acidic soils are discussed.

Modeling Release of Chemical Constituents in Surface Mine Runoff

ABSTRACT THE dominant soluble inorganic compounds in geologic strata spoiled during surface mining of coal are gypsum CaS04-2H20) and magnesium sulfate (MgS04-nH20). The concentration of the soluble constituents in the runoff water or water stored in ponds are a function of the ratio of volume of water to weight of sediments, the thermodynamic interactions between solution ions and clay colloids, and the thermodynamic interactions between the various ions in the solution (water). The above consider the fact that water infiltration in many spoils is generally negligible. A computer model was developed based on thermodynamics of certain chemical reactions. The reactions include: (a) gypsum and magnesium sulfate solubility in water; (b) stability constants of the ion pairs calcium sulfate (CaSOJ), magnesium sulfate (MgSOS), potassium sulfate (KSO^, sodium sulfate (NaSO^, bisulfate (HSO^, ammonium sulfate (NH4SO~4), calcium chloride (CaCl+), and magnesium chloride (MgCl^); and (c) the exchange selectivity coefficients between solution ions and clay colloids for the Ca-Mg and Z-(CaH-Mg) systems, where Z deonotes any monovalent cation. The model was tested with data from the literature and dissolved constituent released into runoff water from coal spoils during simulated rainfall. The values predicted by the computer model correlated well with the experimental values. This project demonstrated that modeling water quality based on solution ion interactions, mineral precipitation-dissolution, and ion exchange has great potential for predictive purposes. This is especially true when multi-ion interactions are involved, which is the rule rather than the exception for natural water systems. Strength, weaknesses, and limitations of this particular model were also discussed.