Leaching Of Sodium Research Articles

Air-Stable Prussian White Cathode Materials for Sodium-Ion Batteries Enabled by ZnO Surface Modification.

Iron-based Prussian white (PW) is one of the promising cathodes for sodium-ion batteries, owing to its high capacity and low cost. However, the practical application of PW is hindered by its poor air stability. The metal-oxide coating has been proven to be an effective way to improve the air stability of electrode materials. Whereas, the target electrode materials conventionally need to be dissolved in the aqueous solution to obtain precursor composites and subsequently calcined at a high temperature during the metal-oxide coating process, which could destroy the phase structure of PW as a result of the sodium leaching into the water and thermal decomposition at the high temperature. In this work, we propose a facile method to construct a ZnO surface layer on PW by utilizing ethanol as a solvent and a mild post-treatment temperature. The ZnO coating layer effectively enhances the air stability of PW and induces the formation of the stable interface on PW. The PW-5 wt % ZnO-E (exposed in 60% humidity air after 30 days) cathode demonstrates a much higher capacity retention (94.1%) at 1 C after 200 cycles than that of PW-E (54%). This work lays a solid foundation for further application of PW.

Leaching of base and metal cations from litter and soils vary in two forest stands with different tree species

Understanding the distribution of cations in forest soils is important for forest management. Here, we evaluated the leaching of cations, potassium (K+), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), iron (Fe3+), aluminium (Al3+), and manganese (Mn2+), from litter through soils in two forest stands with different tree species. We incubated Castanopsis carlesii leaf litter in a Castanopsis carlesii stand and Cunninghamia lanceolata needle litter in a Cunninghamia lanceolata stand using a microcosm method with monthly collections of litter and soil leachates, and the concentrations of cations and fluxes of these cations were assessed separately. We found more Ca2+ but less Na+, Mg2+, and Fe3+ fluxes in litter leaching solutions in Cunninghamia lanceolata than in Castanopsis carlesii stand because of their different initial concentrations in fresh litter. Although cations leached from leaf litter differed among tree species, the leaching fluxes did not vary between stands. Moreover, annual fluxes of cations leached from soils were significantly higher than those from leaf litter, leading to a net loss of soil nutrients to downstream environment. Therefore, the results suggest that reforestation with mixed stands by introducing broadleaved trees in Chinese fir monoculture plantations might reduce soil nutrient loss through the leaching pathway.

Revealing the structure of the sodium-leached layer of soda lime silica glass: A comprehensive spectroscopic analysis

Acid treatment of soda lime silica glass results in incongruent leaching of sodium from the surface, with minimal dissolution of the silicate network or the other cationic network modifiers. The structure of this sodium-leached region was probed using nanoscale-FTIR and Raman spectroscopy. After accounting for interfacial interference, the resultant spectra were compared with molecular dynamics simulations to connect the observed spectral changes to the structure. This comparison showed that the correlations between spectral features and bond parameter distributions derived from the melt-quench formed glass can also be applied to a chemically-modified glass. Additionally, the IR active shoulder at ∼950 cm-1 which was traditionally attributed to the non-bridging oxygen stretch mode, was confidently correlated to perturbations in the silicate network which results from the network modifiers which charge compensate those non-bridging oxygen. The decrease in this spectral feature after acid treatment then corresponds to localized structural relaxations as the glass network becomes more silica-like.

Research on the Removal of Sodium from Vanadium Tailings by Calcification Roasting and NaOH Leaching

Vanadium tailings are a common solid waste in the vanadium industry. As they are rich in Fe, vanadium tailings could be a potential raw material for the blast furnace. However, the presence of approximately 4% Na2O in vanadium tailings is a major impediment to its return to the blast furnace. A novel method for removing sodium from vanadium tailings by calcification roasting and subsequent NaOH leaching was proposed in this work. The method demonstrated that calcification roasting of vanadium tailings can not only volatilize a part of sodium but also facilitate the dissolution of sodium during the subsequent NaOH leaching process. The thermodynamic analysis and behaviors of vanadium tailings during calcification roasting were systematically investigated. The transformation of sodium-containing phases in vanadium tailings during calcification roasting was studied. Further, the promoting effect of calcification roasting on sodium leaching by NaOH was clarified. The total removal efficiency of sodium was 80.37% under optimal conditions, and the residue obtained after sodium removal can be used as a raw material in the blast furnace process for in-plant recycling.

Afforestation affects vertical distribution of basic soil characteristics and taxonomic status of sodic soils

Afforestation, settled before 60–90 years and adjacent solonetzic grasslands, representing the natural vegetation cover were compared in this study based on their basic soil characteristics (pH, CaCO3 content, soil organic carbon (SOC), and exchangeable sodium percentage (ESP)) up to 2 m depth. The assumption was that the plantings of arbour vegetation can change soil characteristics of sodic soils not only in superficial layers but even in larger depths. Grasslands and forest soils were compared by standardised depths. Afforested soils showed lower pH in the depth at 0–100 cm, and slightly higher SOC content in subsoil (20–100 cm). CaCO3 content was significantly different (higher) only at the depth of 50–100 cm in afforested soils. Remarkable differences in ESP values were measured. Afforestation had in almost every layer (0–20, 20–50, 50–100 and 150–200 cm) a significant lower ESP value than grassland soil samples from the same depths. As the value of the ESP is relevant from soil classification purposes as well, the leaching of sodium also can change the taxonomic status of the soils from soils with natric horizon, to soils with Sodic or Bathysodic qualifiers.

Evaluation of leaching potential of penoxsulam and bispyribac sodium in Punjab soils under laboratory conditions

ABSTRACT For developing mitigation methods to decrease or eliminate the risk of water contamination around crop areas, a thorough understanding of the leaching process is required. It also affects the efficacy of herbicides towards the target weeds. The study investigated the leaching of penoxsulam and bispyribac sodium in soils with varied physicochemical properties. Quantification was done using liquid chromatography tandem mass spectrometer. Penoxsulam was found to be moderately mobile and 86.3–90.2% of the applied herbicide was detected in soil column and residues in leachate were below the limit of quantification (0.008 µg mL−1). On the contrary, only 20.8–29.9% of the applied bispyribac sodium was detected in the soil columns and 62.8–87.12% was present in leachates. The highest leachability of penoxsulam and bispyribac sodium was found in loamy sand followed by sandy loam, loam, silt loam and clay loam. The results corroborated well with index-based leaching model using principal component analysis. Therefore, it is important to propose remediation method to avoid the potential adverse effect of herbicide behaving as leachar compound.

Vibrational Spectral Analysis of Natisite (Na2TiSiO5) and its Structure Evolution in Water and Sulfuric Acid Solutions.

Natisite (Na2TiSiO5) is a layered sodium titanosilicate containing TiO5 square pyramids. The structure evolution of natisite in water and acid solutions is the basis for its potential applications. With Na2SiO3 as the silicon source, natisite with the shape of the square sheet was selectively prepared from the hydrothermal method with 14.3 mol/L NaOH solution at 240 °C. Natisite has 20 Raman active modes and 22 infrared active modes from the first-principles calculations within density functional theory, and the calculated Raman and infrared spectra agree well with the experimental ones. The characteristic Raman peak at 844 cm−1 is caused by the symmetric stretching of the apical Ti–O bond in the TiO5 unit, assigning to A1g and B2g modes. Natisite remains relatively stable in water with a sodium leaching percentage of lower than 6%. When washing with sulfuric acid solutions, the interlayer spacing of natisite is reduced due to the extensive removal of sodium ions, and an intermediate composed of SiO4 and newly formed TiO6 units may be formed. Moreover, after washing with water and acid solutions, 95.5%, 63.4%, and 35.2% of Na, Si, and Ti in natisite can be leached in total, respectively, resulting in the structural disintegration of natisite.

Effects of Soil Amendment on Early Growth of Moringa Oleifera in Nasarawa State, Nigeria

In recent times, Moring aoleifera has gained a lot of popularity due to recent discovery of its usefulness to mankind resulting in rapid interest in growing of plant either for local or export purposes. It is highly nutritious and medicinal plant with great agricultural industrial and domestic uses. One factor required for optimum yield of the crop is adequate nutrient in the soil and its proper management. This can be achieved through incorporation of organic matter into the soil to improve the nutrient status in a sustainable manner. Therefore, the objective of the study is to determine the effect of combined application of Biochar and NPK 15:15:15 on growth performance of Moringa oleifera. Data obtained were subjected to statistical analysis using the analysis of variance. Means that were significantly different were separated using the Least Significant Difference (L.S.D. The research revealed Significant different on Leaf Number, Plant Height, Stem Girth) of Moring growth parameters. On Plant Height, T7 = (Biochar16tons/ha 6.4kg + NPK120gs + Urea: 13.5gs) (8WAP) show significant difference (0.049**) at 1% level of significant compared to T3 andT4 that received only biochar at the rate of 8tons/ha and 16tons/ha and T0 (control) which received neither biochar nor NPK 15:15:15 + Urea having the lowest Plant height. Furthermore, the study showed that application of biochar to soil increased soil pH of acidic soil and reduced leaching of Organic Carbon, Organic Matter, Nitrogen, Sodium, Potassium and Cations Exchange Capacity (C.E.C) compared to non-amended treatments. It could be recommended that biochar can be used as soil amendments to improved soil quality and crop productivity such as Moringa oleifera in a variety of soil.

Sodification and solodization processes: Pedogenesis or natural soil degradation?

Sodium-affected soils occur predominantly in arid and semi-arid regions. Sodification and solodization are the two main pedogenetic processes in the formation and evolution of these types of soils, in the landscape. In this study, we used soil morphological, physical, and hydraulic analyses to test the hypothesis that sodification and solodization are natural processes of soil degradation, constituting a form of regressive pedogenesis. Sodium-affected Solonetz, Vertisol, and Planosol profiles were sampled and subjected to morphological, physical, and hydraulic analyses. Under the influence of sodification, Solonetz and Planosol showed signs of regressive pedogenesis, including the formation of a surface horizon with sandy texture, weak structure, reduced available water capacity, and evident characteristics of natural erosion. The morphological, physical, and hydraulic properties of Vertisol were not influenced by sodification. Solodization (sodium leaching and topsoil acidification) had a positive effect on the structural characteristics of Planosol, increasing the degree of flocculation (55–100%); thus, solodization was not associated with natural degradation. Sodification and solodization are antagonistic processes. Whereas sodification can be regarded as a form of regressive pedogenesis leading to natural degradation of sodium-affected soils, solodization is a progressive process of profile evolution. Degradation is a natural phenomenon caused by regressive evolution factors during the formation of Solonetz and Planosol profiles. Our results may guide the development of land management strategies for sodium-affected soils in semi-arid regions according to their use capability.

Hydration and reaction mechanisms on sodium silicate glass surfaces from molecular dynamics simulations with reactive force fields

AbstractRecent development of reactive force fields have enabled molecular dynamics simulations of interactions between silicate glasses and water at the atomistic scale. While multicomponent silicate glasses encompass a wide variety of compositions and properties, one common structural feature in these glasses is the combination of the network structure that is made up of silica tetrahedra linked through corner sharing interspersed with network modifiers like alkali and alkaline‐earth ions that break up the Si–O–Si linkages by forming nonbridging oxygen. In reactions with water, ion exchange between alkali ions in the glass and proton or hydronium in the solution, as well as hydrolysis reaction of the Si–O–Si linkages and subsequent silanol formation, is observed and well documented. We have used a set of recently developed reactive force field to investigate the reactions between water and the surfaces of silica and sodium silicate glasses of different compositions for reactions up to 8 nanoseconds. Our results indicate sodium leaching into water and diffusion of water molecules up to 25 Å into the glass surface. We examined the structural and compositional changes inside the glass and around the diffused ions and use these to explain the rates of silanol formation at the surface. We also observed proton transport in the glass which has an indirect influence on the silanol formation rates. While the surface of the glass was rough to start with, it undergoes further modification into a hydrated gel‐like structure in the glass for up to 5 Å in the higher alkali containing glasses. It was found that the leached sodium ions remain close to the interface and that fragments of silicate network from the surface is capable of dislodging from the bulk glass and enter the aqueous solution. These simulations thus provide insights into the formation and structure of an alteration layers commonly observed in multicomponent silicate glasses corroded in aqueous solutions.

Effect of heat processing on the nutrient composition, colour, and volatile odour compounds of the long-horned grasshopper Ruspolia differens serville.

Heat processing is commonly used to prepare edible insects for consumption. This study aimed at determining the effect of boiling and subsequent oven roasting on Ruspolia differens' nutrient composition, colour and odor compounds. Boiling leads to: a significant increase in protein and decrease in fat content on a dry matter basis; a minimal influence on its amino and fatty acids profile; a significant reduction in its ash content due to leaching of phosphorus, potassium and sodium; a significant increase in iron, zinc, copper, manganese and calcium content; and a fivefold reduction in the amount of vitamin B12. Roasting leads to a relative increase in the amount of calcium and trace mineral elements but doesn't affect other nutrients. Roasting results into a more uniform colour intensity when green and brown polymorphs are roasted together. Lipid oxidation is responsible for the colour and aroma of heat processed R. differens.

Leaching characteristics of biomass ash-based binder in neutral and acidic media

Biomass ash results from the combustion of agricultural residues, which, in many developing countries, are a primary source of power generation for small and medium size industries. This study focuses on the performance of a binder synthesized from an Indian biomass ash, Indo-Gangetic clay, hydrated lime, and aqueous 1M NaOH solution. To measure the extent of leaching and its impact on physicochemical properties, the biomass ash binder in powder form (<45 μm size) was exposed to two different leaching media: deionized water and 0.1M HNO3 at two different solution-to-sample ratios (by wt.) of 10 and 100. Sodium leaching was found to be prominent in the biomass ash binder irrespective of leaching medium and solution-to-sample ratio. However, calcium leaching was significantly higher in 0.1M HNO3 than in deionized water. Calcium silicate hydrate present in the biomass ash binder was found to be less chemically stable in 0.1M HNO3, exhibiting complete calcium leaching at a solution-to-sample ratio of 100. Furthermore, significant leaching of calcium in 0.1M HNO3 solution resulted in phase modification of calcium silicate hydrate, the main reaction product of the biomass ash binder.

Mechanistic study of ultrasound-assisted solvent leaching of sodium and potassium from an Indian coal using continuous and pulsed modes of operation

Unburnt coal in a boiler gets converted to fly ash and bottom ash. Fly ash particles travel along with flue gas and get deposited on heat transfer surfaces along the way. Fouling and slagging are phenomena associated with fly ash deposits which could potentially damage the heat transfer surface, if left unattended. Sodium and potassium are directly linked to the deposition of fly ash, as they form a molten salt film which aids in sticking of fly ash particles. Ultrasound is one of the mitigation techniques used to prevent ash deposition. This study aims at reducing the concentrations of alkali metals in coal as a pretreatment method, using ultrasound. Two modes of operation are chosen: continuous and pulsed. A solvent has been used to enhance the leaching process. In the pulsed mode, the sample is alternated between periods of exposure and nonexposure. A maximum leaching rate of 62% for potassium and 24.5% for sodium was observed in the continuous mode at 360 kHz of operation while pulsed mode of operation showed a maximum leaching rate of 91.3% and 54.4% for potassium and sodium operated at 360 kHz, respectively. The experimental data have been fit to the shrinking core model, and the rate-controlling step has been found to be surface diffusion of reactants into the core. The effect of various parameters is analyzed and compared for pulsed and continuous modes of operation. Order of the reaction, activation energy, and leaching kinetics are obtained by fitting the data into the shrinking core model.

Effect of ammonium chloride on leaching behavior of alkaline anion and sodium ion in bauxite residue

Abstract This study focused on leaching behavior of alkaline anion and sodium in bauxite residue through ammonium chloride treatment. The results showed that the pH of bauxite residue decreased from 10.49 to 8.93, total alkaline anion ( HCO 3 − , CO 3 2 − , OH−, A 1 O 2 − ) concentration reduced from 38.89 to 25.50 mmol/L, leaching rate of soluble sodium was 80.86% with ammonium chloride addition of 0.75%, liquid/solid (L/S) ratio of 3 (mL/g), temperature of 30 °C and reaction time of 18 h; L/S ratio was the main factor affecting the removal of alkaline anion and the leaching of sodium. Furthermore, ammonium chloride promoted the dissolution of diaspore and changed the micro/morphological characteristics with the increase of massive structure. The findings of this work will contribute to achieve soil-formation of bauxite residue.

Chemical Properties of the Salt-affected Soils and Performance of Wheat (Triticum aestivum) with Saline and Alkali Water Irrigation

Effect of different quality of irrigation water viz., normal tap water (NTW, EC 0.7 dS m−1), dilute saline water (DSW, EC 5.0 dS m−1; SAR 5.0 mmol½ L−½), concentrated saline water (CSW, EC 10.0 dS m−1; SAR 5.0 mmol½ L−½), dilute alkali water (DAW, RSC 2.5 me L−1) and concentrated alkali water (CAW, RSC 10.0 me L−1) on the soil chemical properties and its impact on growth and yield of wheat (cv. KRL 213) was evaluated in normal (pHs 7.5, ECe 1.0 dS m−1), saline (pHs 7.7, ECe 10.6 dS m−1) and alkali (pHs 9.15, ECe 2.9 dS m−1) sandy loam soils in the micro-lysimeter. The ECe increased by 9.5, 12.5 and 5.5, 7.0 times due to DSW and CSW irrigation in normal and alkali soils, respectively as compared to initial values, whereas decrease in ECe was observed in all water treatments except CSW in saline soil. Increase in pHs of normal and saline soils was more pronounced in case of NTW, DAW and CAW as compared to alkali soil. On application of DSW and CSW, decrease in pHs was observed in alkali soil, whereas it remained constant in normal and saline soils as compared to initial. Exchangeable sodium percentage (ESP) increased with all water treatments in normal, saline and alkali soils. This increase was more pronounced under NTW, DAW and CAW in alkali soil as compared to normal and saline soils. Sodium concentration in saturation paste increased by 15 to 17 times in normal soil, 3.5 to 4.5 times in alkali soil under DSW and CSW, respectively. Sodium leaching was observed in saline soil under all water treatments except under CSW where it increased to 1.2 times. Sodium build-up was increased 1.5 to 2.0 times under all water treatments in normal, saline and alkali soils as compared to post rice sodium concentration. Increase in organic carbon content was observed in surface samples in normal soil, whereas it was not as pronounced in saline and alkali soils. Calcium carbonate increased significantly in all depths in three soils under DAW and CAW. Wheat yield reduced approximately by 4, 11 and 34 per cent under normal, saline and alkali soils, respectively in DAW as compared to NTW, whereas CAW reduced grain yield by 31 per cent in normal, 87 per cent in saline and near total loss of crop was observed in case of alkali soil as compared to NTW. The DSW reduced yield by about 22 per cent each in normal and saline soils and about 70 per cent in alkali soil. Application of CSW reduced yield by 70 per cent in normal soil, whereas near complete loss of crop was observed in saline and alkali soils as compared to NTW.

Kinetics of desilification pretreatment from high-aluminium coal fly ash in alkaline medium under pressure

In this paper, desilification for high-aluminium coal fly ash in alkaline media under pressure was reported to improve the efficiency of sodium leaching. Factors such as the alkaline quantity, reaction temperature, time and liquid-to-solid ratio on desilification were studied in detail. At the same time, the kinetics of desilification were analysed to further reveal the leaching mechanism. The results showed that the alkaline quantity, reaction temperature and liquid-to-solid ratio had significant effects on the desilification efficiency with increasing reaction time. The maximum SiO2 leaching rate was 65.78% under the optimal experimental conditions. According to the shrinking core model, the process of leaching is controlled by surface chemical reactions in the earlier stage and diffusion of the solid layer in the later stage.

DETERMINATION OF TRANSPORT PARAMETERS FOR SOLUTES IN SALT-TREATED SOIL COLUMNS

A laboratory experiment was carried out at the Department of Soil Sciences and Water Resources, College of Agriculture, University of Baghdad. Silty clay soil was treated with three salt solutions (NaCl, CaCl2 and mixed NaCl–CaCl2). Homogeneously packed soil columns (10 cm, 40 cm) were leached six times using tap water. Effluent samples were collected to determine ion concentration Cl-, Ca++, Na+, K+ and Mg++. Breakthrough curves were used to estimate solute transport parameters (retardation factor, peclet number) using an analytical solution of convection-dispersion equation (CDE) by CXTFIT program. The results showed that relative concentration of chloride was increased rapidly with calcium chloride, which increased sodium leaching rate at starting of breakthrough curve. Sodium chloride increased water requirements for calcium displacement. Results indicated a good fitting of convection-dispersion equation with breakthrough curves data. The best-fit were used to calculate peclet number, retardation factor and dispersion coefficient. When soil was treated with calcium chloride, Peclet number of chloride was increased from 3.13 to 6.48, while it has been decreased for calcium, sodium and potassium. Sodium chloride decreased peclet numbers of chloride, calcium and sodium. Also mixed salts increased sodium peclet number from 1.01 to 9.02. Results showed, calcium chloride decreased retardation factor of chloride from 1.59 to 0.50, while it has been increased from 1.39, 1.58 to 175.00, 493.36 for each of sodium and potassium, respectively. Retardation factor of calcium was decreased when soil was treated with sodium chloride or mixed salts. Dispersion coefficient was decreased for chloride, and increased for calcium and magnesium. When soil was treated with calcium chloride, dispersion coefficients have been increased from 24.29, 25.56 to 40.51, 40.89 cm2hr-1 for sodium and potassium, respectively.

Improvement of Sodium Leaching Ratio of Ferric Bauxite Sinter after Direct Reduction

The sodium leaching ratio (ηN) of ferric bauxite direct reduction process is much lower than that of ordinary bauxite; thus, the former consumes more sodium than the latter. ηN can be promoted by increasing the dosage of sodium or restricted by increasing the heating temperature and time. However, the restriction effect of heating temperature is 16.67 times larger than that of heating time, and the restriction effect decreases 47.03 times faster when heating temperature increases than that process of heating time. These imply that ηN improves with the increasing sodium carbonate dosage and the decreasing heating temperature.

Investigation of CaO-based sorbents derived from eggshells and red mud for CO2 capture

A series of CaO-based sorbents, using low-cost eggshells and red mud (Rm) pretreated by the acid leaching process as raw materials, were synthesized by the dry mixing method. The effects of different sodium leaching ratios, Rm doping contents, and eggshells as calcium precursors on CO2 capture properties of the CaO-based sorbents are discussed in this paper. The cyclic carbonation/calcination performance of the as-prepared sorbents was evaluated by a thermogravimetric analyzer. The phase compositions and morphologies of the sorbents were characterized by XRD and SEM, respectively. The as-prepared sorbents doped with 10 wt% Rm3 (with a sodium leaching ratio of 99.91%) showed a superior cyclic conversion of 46.67% after 100 carbonation/calcination cycles. The existence of the Ca12Al14O33 phase was probably responsible for the excellent CO2 cyclic performance.

Investigation of damp heat effects on glass properties for photovoltaic applications

ABSTRACTDamp heat test was performed on soda-lime glass to characterise functional properties of glass in photovoltaic applications and define the ageing mechanism. In addition to the optical property measurements, SEM-EDX, XPS and FTIR analyses were carried out. The damp heat exposed samples presented an increased transmittance in UV, visible and near-IR ranges namely within (1900–2100 nm). The results were explained by hydration of glass network with heat. An ageing mechanism based on glass corrosion theories is discussed. Molecular water adsorption involves a leaching process of network modifier cations and especially sodium ions. Hydrolysis also occurs in silica network by reacting free molecular water. This phenomenon enhances concentration of hydroxyl groups in glass highlighted by FTIR measurements and promotes formation of silanol groups. A tin side dependence on sodium leaching which acts as a passivating barrier for ionic transport is highlighted which may be taken into consideration for photovoltaic module design.