Effect Of Salt Content Research Articles

Vulnerabilities in the Production of Biogas from the Fat-Containing Tannery Waste

Background. The problem of disposal of the fat-containing tannery waste can be solved by anaerobic fermentation. This raises the important question of the effect of inhibitor compounds on the process of methanogenesis and on the output of biogas. In particular, the effects of NaCl and NaHCO3 used in technology and antibiotics that accumulate in subcutaneous fat when used in animal husbandry for digestion of fat-containing raw materials have not yet been studied.Objective. The purpose of the paper is determination of possible influence of salts and antibiotics on the process of methanogenesis and on the output of biogas and methane.Methods. The study was conducted in laboratory reactors with a volume of 0.5 dm3 under anaerobic conditions at 38 ± 1 °С with the addition of different concentrations of salts and antibiotics (the sample was used without the addition of test compounds to control the process). The anaerobic association of microorganisms in the form of an inoculum served as the biological agent.Results. The effect of salt content on the destabilization of methanogenesis during digestion of fat-containing raw materials and the effect of the antibiotic content of tetracycline and norfloxacin on the yield of biogas from fatty raw materials were determined. Thus, with the use of NaCO3, the greatest inhibition occurs at a concentration of 11.4 g/dm3 (decrease in biogas output by 54%), with a further increase in the concentration to 22.8 g/dm3 an increase of 18.2% is observed compared to the concentration of 11.4 g/dm3. It is shown that the concentration of methane in biogas with the use of NaCO3 decreases with increasing concentration of the inhibitor, which confirms its negative impact on the process of methanogenesis.Conclusions. Biogas yield is increased by 17% at a NaCl concentration of 3.8 g/dm3, and biogas and methane production decreases even more at NaCl concentrations of 7.6 g/dm3. When using antibiotics, tetracycline and norfloxacin, the allowable rate in raw materials is 2.5 mg/dm3 for both antibiotics.

Effects of salt content on secondary structure of protein in sodium alginate/antarctic krill protein composite system and characterization of fiber properties

The sodium alginate (SA)/antarctic krill protein (AKP) composite fibers were prepared by wet spinning in 5% (w/w) CaCl2 coagulation bath. In this work, salt regulated protein secondary structure to prepare high performance fiber, and the relative content of secondary structure in the composite system was calculated by fourier transform infrared spectroscopy (FT-IR). The surface morphology, crystallinity, thermal stability, mechanical properties, thermal conductivity and conductivity of the composite fibers were characterized by scanning electron microscope (SEM), x-ray diffraction (XRD), differential scanning calorimeter (DSC), orientation tester, thermal conductivity meter and resistivity test bench. The results revealed that the salt changed the secondary structure of protein by affecting the intermolecular interaction and cross-linking degree of the SA/AKP composite system. After the fine partitioning of the salt content range, with the NaCl mass fraction of 0.7–1.0%, the controllable range of α-helix content, β-sheet content and random coil content are 8.14–25.15%, 52.58–60.87%, 21.53–30.99% for the SA/AKP composite solution, respectively. And the controllable range of α-helix content, β-sheet content and random coil content are 5.62–10.32%, 50.31–57.69%, 33.71–44.07% for the SA/AKP composite fiber, respectively. With the increase of salt content, the crystallinity showed an increasing-decreasing-increasing trend, the thermal conductivity, mechanical properties and orientation degree exhibited a trend of increase-to-decrease, and the thermal stability changed little. Besides, the conductivity of the composite fibers is affected more by the crystallinity of the material, and the surface morphology is also related to the salt content.

Crude Oil Desalting Using Multi-Surfactant Based on a Best Dosage, Solvent and Mixing Ratio

Crude oil desalting is the first processing step in a refinery. The objectives of crude desalting are the removal of salts, solids, and the formation of water from unrefined crude oil before the crude is introduced in the crude distillation unit of the refinery. The experimental work is divided into three schemes covering the effect of surfactant dosage, test different types of surfactants, and the effect of salt content on desalting efficiency. The results show that the crude oil desalting efficiency, increased with increasing surfactant quantity. The results indicate that desalting efficiency has lowered with increasing the salt content in crude oil. Also, the results show that the best solvent was toluene, and the best mixing ratio of solvent was 10 Vol. %.

Stimulation of Native Microorganisms for Improving Loose Salty Sand

Prolonged droughts and excessive water harvesting in western Asia has accelerated desertification and caused longer dry seasons of salt lakes. The Aral Sea experience has proven that dust from saline soil is a serious health issue. Various stabilization techniques to reduce wind erosion have been used in the past. However, in recent years, a potentially viable method has been developed; microbial induced calcite precipitation (MICP) has been introduced as a method of soil stabilization, though its effectiveness in saline soils remains to be examined. The effect of salt content in loose sandy soil on calcite precipitation of calcite through stimulation of native bacteria is investigated in this article. Samples with salinity up to 30% salt content were prepared and treated with different culture medium compounds. A number of tests were used to evaluate the effect of the mentioned parameters. The results show that improvement increases with increasing salinity up to 5% salt, and further increase in salinity reduces the effectiveness of improvement. It is also shown that the addition of urea in the culture medium has a significant effect on the urea hydrolysis which resulted in a five-fold increase in compressive strength. Four native strains of halotolerant urease-positive bacteria were also identified.

Static and cyclic shear behaviour of saline dredged sand

ABSTRACT Large amounts of dredged sand accumulate along the banks of the Suez Canal in Egypt, which can be used in engineering applications subject to monotonic and cyclic loading. This research studied static and cyclic shear behaviour of reconstituted saline dredged sand. Constant volume direct simple shear tests were conducted to evaluate the effects of salt content (SC), relative density (Dr ), cyclic stress ratio (CSR), and normal effective stress (σvc’) on static and cyclic resistances of saline sand. Tests were conducted on specimens prepared at Dr of 40 and 80% with SC ranging from 0.25% to 20%. Specimens were consolidated at different σvc’, then sheared statically or cyclically at different CSR values. The results of conducted tests showed that the angle of shearing resistance decreased as SC increased beyond 4%. Failure under cyclic loading was governed by liquefaction rather than cyclic mobility. The cyclic resistance increased as SC increased beyond 9%.

Drying kinetics, adsorption isotherms and quality characteristics of vacuum-dried beef slices with different salt contents

In this study, the effect of salt content (0, 5, 10, 15 and 20 g/100 g dry basis) on the drying kinetics, adsorption isotherms, and quality characteristics of beef slices were investigated. Beef slices were salted and vacuum-dried at 70 °C, until a moisture content of 32% (dry basis). The adsorption isotherms of the dried beef slices were described at 25 °C. The drying time for beef slices at the salt contents of 0, 5, 10, 15 and 20 g NaCl/100 g d.b. were 212, 207, 194, 160 and 137 min respectively. Modified Henderson and Pabis, and Page models exhibited a better fit for the drying kinetics of beef slices than the other drying models tested. The adsorption isotherm of dried beef slices is typical Type-II, but the addition of salt led to this behavior to change to type III. The BET model (R2 > 0.98 and %E ≤ 13.40) for all samples exhibited a good fit to the experimental data.

Structure, electrical properties and reaction mechanism of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 ceramics synthesized by the molten salt method

Abstract Lead-free (Ba 0.85 Ca 0.15 )(Zr 0.1 Ti 0.9 )O 3 (BCZT) ceramics with excellent electrical properties were successfully synthesized by a molten salt method (MSS). The submicron BCZT powders with pure perovskite phase were obtained by adjusting the KCl-NaCl content that was used as the eutectic salt. The effects of salt content and reaction temperature on the structure and properties of the BCZT materials were systematically investigated. Comparing with BCZT ceramics prepared by solid state method (SS), the reaction temperature of BCZT ceramics synthesized by MSS decreased approximately 200 °C. Moreover, BCZT ceramics sintered at 1360 °C with 50% eutectic salt showed the most outstanding electrical properties, which are as follows: d 33 = 604 pC/N, k p = 57%, P s = 17.11 µC/cm 2 , P r = 9.98 µC/cm 2 , e m = 15872, e r = 2654 and tan δ = 0.013. In addition, this work revealed a possible reaction course processes and mechanism about MSS. The results provide a new design to optimize the performance of BCZT lead-free piezoelectric ceramics.

Effect of salt content and type on emulsifying properties of hull soy soluble polysaccharides at acidic pH

Hull soluble polysaccharide (HSPS) is a novel product consisting in a mixture of polysaccharides and proteins extracted from soy hulls by using a methodology based on the extraction of citric pectins. In this work we studied the effect of the addition of two different salts (NaCl and CaCl2) on the emulsifying properties of HSPS at acidic conditions. Low and high homogenization energies were used, obtaining coarse and fine emulsions, respectively. Mean droplet size, the stability against destabilizing processes (creaming, flocculation and coalescence) and the rheological properties of the emulsions were analyzed. Also, the rheology of the O/W interface was studied by using du Noüy ring geometry. Coarse HSPS emulsions were unstable to creaming, being more stable in the presence of salts. In contrast, fine HSPS emulsions showed long-term creaming stability similar to those performed with commercial citric pectin (CCP), although they differ in particle size distribution and flocculation degree. The presence of CaCl2 reduced the mean size of droplets in fine HSPS emulsions and improved their stability to flocculation and coalescence. Significant differences were observed in the rheological behavior of O/W emulsions and interfaces of HSPS and CCP with respect to the salt addition.Our results indicate that HSPS can be used in the formulation and stabilization of acidic O/W emulsions. Besides, HSPS generates emulsions with different characteristics than those obtained with citric pectins. The use of HSPS provides a suitable alternative in food engineering contributing to the exploitation and valorization of soy hulls, which represents an important waste material in soybean processing.

Performance of ceramic nanofiltration membrane for desalination of dye solutions containing NaCl and Na2SO4

Removing mixture salts from dye solutions using membrane technology still need to be improved for high dye rejection and low salt rejection. In this work, ceramic membrane with pore size of 1.5nm presented a satisfactory desalination of dye solutions containing NaCl and Na2SO4 compared with two commercial organic nanofiltration membrane elements (DK and DL). Effect of salt content, salt type, molar ratio of NaCl and Na2SO4, dye concentration and pH on performance of ceramic membrane for desalination of Eriochrome black T (EBT) were investigated. The results showed that dye rejection decreased by increasing salt content, dye concentration and solution pH. Compared with dye-NaCl solutions, a relative high flux and low rejection of dye were observed when treating dye-Na2SO4 solutions. For the mixture salt-dye solutions, the flux, which was higher than that for the single salt-dye solutions, first increased then decreased with decreasing CNaCl/CNa2SO4 due to the change of structure of cake layer. Supper-molecule aggregates of EBT formed by hydrogen-bond is mainly responsible for the high rejection of EBT (>99%) at acid conditions. The rejection of NaCl and Na2SO4 was below 20% and 40%, respectively. These promising results demonstrates that the new ceramic membrane has a potential application in dye purification.

A new generalized Henry-Setschenow equation for predicting the solubility of air gases (oxygen, nitrogen and argon) in seawater and saline solutions

A generalized expression for estimating the solubility or air gases (oxygen, nitrogen and argon) in saline solutions at atmospheric pressure is presented. The generalization is done for the Henry's constant (to consider the effect of temperature) and for the Setschenow parameter (to consider the effect of salt content in the solution), in terms of the acentric factor, the temperature, and the salinity expressed as the total content of salt. Accurate correlation and prediction of gas solubility is important in various scientific and technological fields and for the design of separation equipment in the chemical and mining-related industries. As a measure of the accuracy of the generalized model, the average deviation, the absolute average deviation and the maximum absolute deviation between correlated and experimental data are evaluated. The proposed model give absolute deviations lower than 1% with some few exceptions, and maximum deviations are always below 4%.

Effect of salt contents on enzymatic activities and halophilic microbial community structure during phenanthrene degradation

The halophilic bacteria could be useful for bioremediation of polycyclic aromatic hydrocarbons (PAHs) pollution in hypersaline environments, which has posed a significant environmental problem. The effect of salt contents on a halophilic bacterial consortium, which was enriched from an oil-contaminated saline soil, was investigated. At 20 per cent salt contents, the consortium maintained lower PAHs dioxygenase (PDO), catechol 2, 3-dioxygenase (C23O) and catechol 1, 2-dioxygenase (C12O) activity than at 10 per cent salt contents before complete degradation. Pyrosequencing results indicated that the predominant bacteria were closely related to genera Thalassospira, Rhodobium, Mariprofundus and Psychroflexus at 10 per cent salt contents, while at 20 per cent salt contents, the dominant bacteria were Chromohalobacter and Methylohalomonas, suggesting some bacteria could not survive at higher salt contents. Increased salt contents decreased the diversity of the bacterial consortium and favored the growth of bacteria in class Gammaproteobacteria. Three-dimensional excitation-emission matrix fluorescence spectra (3DEEMs) showed that elevated salt contents also made some intermediate products accumulated during degradation and then lowered the phenanthrene degradation rate. This study extended the knowledge on decontamination of PAHs in saline environments by an applicable halophilic bacterial consortium.

The effect of salt content on nectar intake of a New World generalist avian nectarivore (Cyanerpes cyaneus: Thraupidae)

ABSTRACT Generalist avian nectarivores visit flowers that produce copious sugar-dilute nectar, and some species can not compensate energy intake when fed solutions with low sugar content (≥5% w/w). Intake of dilute sugar diets by specialist avian nectarivores is limited by salt content, but the potential role of salt on nectar intake of generalist nectarivores has not been tested. We examined intake rate and digestion of solutions with varying sucrose concentrations (2.5–30% w/w) by Red-legged Honeycreeper (Cyanerpes cyaneus) and the effect of salt content (20 and 40 mM L−1 NaCl) on the intake rate and digestion of dilute sucrose solutions (2.5% w/w) of this generalist nectarivore. We tested the hypothesis that Red-legged Honeycreepers do not show compensatory feeding when fed dilute sugar diets, and that salt limits the intake rate and digestion of these solutions. We found that this generalist nectarivore showed compensatory feeding when fed sucrose diets ≥5%, but they did not compensate sugar intake wh...

Effect of salt and moisture content reduction on physical and microbiological properties of salted, pressed and freeze dried turkey meat

Abstract The effect of salt content, pressing and moisture content on textural, micro structural and color characteristics, adsorption isotherms and microbiological count of turkey breast meat were studied. There were no statistically significant differences (P ≥ 0.05) between samples including high salt-moisture and low salt-moisture for color (lightness, redness and yellowness) and textural properties of hardness, cohesiveness, springiness and chewiness parameters and they were determined as 59.10–65.76, 0.30–0.28, 1.27–1.19 and 22.44–22.21, respectively. Total mesophilic aerobic counts, Micrococcus/Staphylococcus counts and yeast/mold counts of samples including low salt and moisture were detected as 3.23, 0, 2.98 (log cfu/g) and they were lower than the same counts of samples including high salt and moisture which were found as 6.66, 6.69, 5.95 (log cfu/g) after 70 days of storage. The reduction of salt content did not increase the growth of these microorganisms if we also decrease the moisture content of turkey meat by freeze drying process. Increase of hardness of turkey meat by drying is not found related to shrinkages according to comparison of air and freeze drying. Reduction of moisture content to 40% reduced freeze dying time to 7 h from 27 h of complete drying in freeze dryer.

Effects of molten salt content and reaction temperature on molten salt preparation of CaNaBi2Nb3O12 powder

Pure bismuth layer-structured ferroelectric CaNaBi2Nb3O12 ceramic powders with anisotropy were prepared by the molten salt method in molten salt fluxes of NaCI–KCl at 750–900 °C. The effects of salt content and calcination temperature on the microstructure and morphology of CaNaBi2Nb3O12 powder were investigated. The phase and the microstructure of reaction products were detected by X-ray diffraction and scanning electron microscopy. The results show that the particle size of CaNaBi2Nb3O12 powders and the level of anisotropy increase with increasing reaction temperature. The sample dispersion gets better with the increase of molten salt content. The CaNaBi2Nb3O12 powders with good micromorphologies were obtained when the mass ratio of salt to raw materials is 1:1.05, calcined at 800 °C for 1 h. The grain is regularly flake-like, with uniform particle size and single good dispersion.

Determination of Effect of Salt Content in Cooling Liquid on the Result of Cable Capacitance per Unit Length Measurement

Capacitance per unit length and related wave resistance refer to the main characteristics of a number of cable products, such as communication cables, control cables or radio-frequency cables. The capacitance per unit length value is regulated by the standards for appropriate types of cables. This study describes the technical implementation of the electrical method of measuring of the capacitance per unit length of the electric cable directly on the production line. It is shown that the change in specific electrical conductivity of water, which a capacitance transducer is dipped into, has a significant impact on the outcome of in-process control of cable capacitance per unit length. A method of offset from the impact of this measurement on the control results is suggested.

Functional hydrogel microspheres: Parameters affecting electrostatic assembly of biopolymer particles fabricated from gelatin and pectin

Hydrogel microspheres may be used for various applications within foods, cosmetics, and pharmaceuticals, such as texture modification, encapsulation, or controlled release. The aim of this research was to examine the key parameters affecting the formation and properties of hydrogel microspheres fabricated by electrostatic complexation of gelatin and pectin. Hydrogel microspheres were formed by mixing 0.5 wt% gelatin and 0.01 wt% pectin at pH 10.0 and 30°C, and then acidifying to pH 5.0 with continuous stirring. The effects of salt content (0–100mM NaCl), shear rate (150–600rpm), and acidification rate (fast, medium, and slow) on the formation and properties of the hydrogel microspheres were investigated. Increased salt content perturbed the complexation process due to electrostatic screening and ion-binding effects, which meant that lower pH values were needed to induce complexation. Optical microscopy and static light scattering showed that salt content also altered hydrogel particle microstructure. The largest particles were formed at an intermediate shear rate (300rpm), which was attributed to the influence of shearing on mixing, particle disruption, and particle coalescence. Hydrogel microsphere size decreased as the acidification rate increased, which was attributed to an alteration in the balance of particle formation and particle growth. The parameters identified in this study facilitate the design of hydrogel microspheres with specific sizes and morphologies, which might be useful for tailoring their functional properties for different commercial applications.

Effect of Salt and Sucrose Content on the Dielectric Properties of Salted Duck Egg White Protein Relevant to Radio Frequency Drying

The dielectric properties of salted duck egg dispersions were measured at the selected frequency range of 10 to 300 MHz by the open-ended coaxial probe method using a network analyzer. The effect of salt content (0–8%) and sucrose content (0–8%) on radio frequency drying (RFD) and the variation of the dielectric properties of the salted duck egg white samples were studied. These results showed that both dielectric constant and dielectric loss factor decreased with the increase of frequency, and the influence was more significant at the lower frequency ranges. At 27.14 MHz, the dielectric constant and dielectric loss factor were increased but the electric penetration depth was increased with the addition of salt and sucrose. The RFD drying rate was significant increased after the adding of salt and sucrose.

Effects of salt content on leaching properties of synthetic bituminized wastes

The leaching properties of soluble components (Na+, NO−3, and NO−2) in synthetic bituminized wastes with various characteristics, such as salt content, salt composition, and bitumen matrix, were quantitatively evaluated by means of an aqueous leaching test. Micropores were formed in the bituminized waste by the leaching of soluble salts. The penetrability of bitumen and the salt content affected the size and the shape of the micropores observed by scanning electron microscopy. The linear relationship between leaching fraction of the soluble components and square root of leaching time was observed, and the diffusion coefficient of the soluble component was determined by Fick's law. The diffusion coefficients of ionic species of interest were similar to each other. Moreover, the diffusion coefficient agreed among bituminized wastes with the same salt content, even if salt composition and bitumen matrix were different. The diffusion coefficient of the component was proportional to the salt content in the synthetic bituminized wastes. It was found that the salt content in the bituminized waste was one of the key factors to determine the diffusion coefficient.

The effects of low salt concentrations on the mechanism of adhesion between two pieces of pork semimembranosus muscle following tumbling and cooking

The aim of this research was to gain deeper insight into the effect of salt content on the adhesion between pieces of semimembranosus pork muscle bound by a tumbling exudate gel. Hydrophobic site number, free thiol and carbonyl content were measured in tumbling exudate and meat protein to evaluate the protein–protein interactions involved in the adhesion process. Proteins were far more oxidized in exudate than in meat, and under our experimental conditions, salt content increased protein bonding in the exudate but not in the meat. Breaking stress increased between non-salted meat and 0.8%-salted meat but did not depend on the protein physicochemical properties of the tumbling exudate. Modifying the meat surface by tumbling alone, tumbling and salting, or scarification had no effect on breaking stress. It is suggested that the break between the meat pieces occurred between the tumbling exudate and the meat surface due to weaker chemical bonds at this location.

Solid phase microextraction method for characterizing the organic fraction of an industrial brine stream

The manufacturing process of DOW Chemical Company in Portugal produces a brine stream containing organic contaminants. For recovering the sodium chloride by-product, it is necessary to fully characterize this brine stream. With this purpose, a direct immersion-solid phase microextraction-gas chromatograph (SPME-GC) analytical method was successfully optimized and implemented, being possible to quantify accurately, with reproducibility, the organic fraction at ppb levels. The effects of salt content, extraction time, temperature, and pH were investigated, and the SPME experimental conditions optimized. For the poly(dimethylsyloxane-co-divinylbenzene) fiber utilized, the resulting parameters were: 25% (wt.) of NaCl, 30 min, 20°C, and pH 11. The fiber desorption was performed at 250°C for 15 min. The calibration curves of the representative organics of the brine (benzenamine, cyclohexanamine, 2-methylbenzenamine, N–cyclohexylcyclohexanamine, cyclohexyl alcohol, nitrobenzene, cyclohexanone, and 4-phenylcyclohexylamine) presented good correlation coefficients (0.991 ⩽ R2 ⩽ 0.997). The detection limits of the method were determined for each species for the optimized analytical conditions; the detection limits vary from 0.21 to 3.22 ppb, respectively for N–cyclohexylcyclohexanamine and benzenamine, the, precision ranged from 4.4 to 8.7% RSD and the validation criteria was obeyed for all analytes. The industrial brine stream was then characterized during several days to register the concentration history of contaminants. Independently of the stream composition fluctuations, the SPME methodology developed and optimized in this work was able to assess accurately their concentrations at ppb levels.