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In present study, sodium carbonate (Na2CO3) and ammonium carbonate ((NH4)2CO3) are separately selected as precipitant to synthesize the strontium oxide (SrO) based solid catalyst, namely, SrO–M/Na and SrO–M/NH4 for biodiesel production through transesterification. The influence of precipitant on catalyst physicochemical property, catalytic activity as well as reusability are investigated and compared. To begin with, transesterification parameters of catalyst amount, molar ratio of methanol to oil, reaction time, and reaction temperature are concerned to comprehensively evaluate catalytic performance of the two catalysts. Moreover, catalyst reusability is evaluated under the optimal conditions. With catalyst amount of 4 wt.%, molar ratio of methanol to oil of 9 at 65 ℃ within 30 min, SrO–M/Na exhibits a better catalytic activity in comparison to SrO–M/NH4, whereas, the reusability is in reverse sequence. In order to reveal the reason behind, catalysts are characterized by thermogravimetric/differential thermogravimetric/scanning calorimetry (TG/DTG/DSC), X–ray diffraction (XRD), X–ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), N2–adsorption/desorption, basic strength, basicity and vibrating sample magnetometer (VSM).

This study presents the experimental investigation of the effect of curing conditions on the properties of mortar mixtures made with sodium carbonate activated slag–glass powder as a binder. Slag and glass powder were used at an equal percentage as the aluminosilicate precursor and the binary blend was activated with sodium carbonate. The corresponding compressive strength and ultrasonic pulse velocity of the mixtures cured in different conditions were investigated. The curing conditions used in this study are dry, moist, and submerged curing. Microstructural investigations were also carried out to understand the microstructural properties of the mixtures exposed to these curing conditions. Results from this study showed that moist curing is the most effective curing method for mortar made with sodium carbonate alkali-activated slag–glass powder as a binder. Microstructural evaluations further confirm the strength results as mortar samples cured in a moist condition exhibited a denser microstructure.

Leaching experiments were performed in calcium aluminate slag with a high-sodium carbonate adaptation of the Pedersen process. A theoretical thermodynamic study of the pregnant leaching solution was conducted to specify the thermodynamically favored species that exist within. Using the HSC 9.0 software, a carbonation process simulation (neutralization of the aluminate solution with CO2 gas) was simulated. Laboratory carbonation experiments were conducted to verify the theoretical predictions. According to the thermodynamic study, at temperatures below 50 °C gibbsite precipitates in the first stages of carbonation and then is transformed to dawsonite. Temperatures over 65 °C favor the direct precipitation of dawsonite. The same route (thermodynamic analysis, carbonation simulation, and experimental verification) was followed by a synthetic solution containing lower amount of sodium carbonate to prove that dawsonite precipitation occurred as a result of the high free carbonate content, to investigate the effect of temperature and to precipitate alumina hydrate phases. Graphical Abstract

The polythermal crystallization method has been used to extract sodium and potassium carbonate salts as valuable by-products. The salt production was carried out using an alkaline carbonate solutio...

Sodium carbonate pretreatment, an environmentally-friendly and efficient pretreatment, was used to improve solid-state ethanol production from corn stover (CS). To further enhance ethanol yield from the pretreated CS, especially at low enzyme loadings, a combined pretreatment, including steam and sodium carbonate pretreatments, was developed. The removal/modification of lignin by sodium carbonate pretreatment (at 100 °C for 3 h) helped to obtain high ethanol titer at high solids and low enzymes loadings. The maximum ethanol concentration was about 44 g/L, obtained after 72 h simultaneous saccharification and fermentation (SSF) of CS pretreated with sodium carbonate without mixing and prehydrolysis at 30% solid and 15 FPU/g enzyme loadings. Applying prehydrolysis and increasing the SSF time to 120 h improved ethanol concentration to 59 and 67 g/L, respectively. Steam pretreatment at 190 °C for 10 min before sodium carbonate pretreatment led to 76% increase in ethanol concentration. At the enzyme loading of only 5 FPU/g substrate, the modified pretreatment increased the ethanol concentration from 24 g/L to 41 g/L, compared with that of sodium carbonate pretreatment. The results showed that hemicellulose removal and delignification by steam and sodium carbonate pretreatment, respectively, considerably improved ethanol concentration at high solids and low enzyme loadings.

Eupatorium adenophorum (EA) has been spread widely in China and its increasing number has posed potential threats and damages to the ecosystem and environment. Therefore, it is urgent to develop an economical and efficient method to convert low-value biomass into high-value products. In this paper, pyrolysis of EA with non-catalytic and with sodium chloride (NaCl) catalyst and sodium carbonate (Na2CO3) catalyst was carried out in a conventional resistance furnace. The maximum yield of bio-oil was obtained with 3 wt% NaCl and 3 wt% Na2CO3, respectively. The composition of bio-oil indicated that NaCl and Na2CO3 promoted the formation of hydrocarbon, alcohol substitution leading to a decrease in the yield of phenol and acid. For bio-gas, the addition of NaCl and Na2CO3 could reduce the elimination of CO and CH4 and promote the formation of H2 and CO2. The results indicated that NaCl and Na2CO3 had the potential to be used as a pretreatment of pyrolysis of EA to generate more resources with low cost.

Hydrothermal liquefaction (HTL) or hydrous pyrolysis is a thermochemical de-polymerisation process in conversion of wet biomass into bio-crude oil and chemicals at moderate temperatures and high pressures. The notable applications of these bio-oils are in boilers, engines and turbines for generation of heat and power or for extraction of chemicals. In this HTL process, experiments were conducted using rice straw as biomass, glycerol as co-solvent and sodium carbonate as catalyst. The effect of temperature (220°C, 240°C, 260°C, 280°C), reaction time (15 min, 30 min, 45 min, 60 min), catalyst dosage (5wt%, 12.5wt%), biomass to water ratio (1:5, 1:10) and glycerol to water ratio (0:10, 5:5) were systematically studied and analysed for evaluation of process performance in terms of yield and selectivity of bio-oil. Central composite design (CCD) was further used to optimize the process variables like temperature, reaction time, catalyst, solvent and co-solvent. Finally, the optimal operating conditions of 12.5 wt% of Na2CO3 at 260°C for 60 min at equal ratios of water and glycerol are established using CCD and were experimentally verified. The obtained product was analysed using elemental analysis, FTIR, GC-MS for determination of properties and it was found that the main compounds constitute ketones, alcohols, phenolics and aldehydes as main compounds in the HTL process.

Sodium bicarbonate is among the alkali chemicals used for dry scrubbing in incineration flue gas treatment. It is generally pulverized into fine particles of ~ 20 µm to increase the specific surface area for higher reaction efficiency with acid gases. However, problems such as bridging or blocking in the storage and supply system can easily occur with pulverized sodium bicarbonate (PSB). Pulverization with the addition of a dispersing agent is performed as a measure that leads to an increase in chemical cost. In this paper, vacuum thermal treatment was examined to produce porous sodium carbonate from coarse sodium bicarbonate (CSB). Pressure, temperature, and heating time were tested to produce sodium carbonate with a specific surface area that is equal to or higher than that of the sodium carbonate (REF) obtained from PSB by spraying it into a fabric filter at 180 °C. Sodium carbonate (P30) with a higher specific surface area than REF was obtained by treating CSB at 180 °C under 30 kPa for 1 h. P30 was proven to have 1.8 times higher HCl removal efficiency than REF. This novel method is expected to resolve the existing issues through both spraying PSB and reducing the air resistance at the fabric filters.

Capturing flue gases often require multiple stages of scrubbing, increasing the capital and operating costs. So far, no attempt has been made to study the absorption characteristics of all the three gases (NO, SO2 and CO2) in a single stage absorption unit at alkaline pH conditions. We have attempted to capture all the three gases with a single wet scrubbing column. The absorption of all three gases with sodium carbonate solution promoted with oxidizers was investigated in a tall absorption column. The absorbance was found to be 100% for CO2, 30% for NO and 95% for SO2 respectively. The capture efficiency of sodium carbonate solution was increased by 40% for CO2 loading, with the addition of oxidizer. Absorption kinetics and reaction pathways of all the three gases were discussed individually in detail.

The present paper illustrates an unconventional but green exhaust dyeing process of cotton, in which the conventional reduction step of the indigo dyeing process is eliminated following the substitution of the insoluble indigo by the soluble indigo carmine. Indigo carmine can meet ecological requirements in terms of chemical consumption reduction, cleaner releases, and biodegradability. However, this dye produces unsatisfactory dyeing quality compared to indigo. In order to enhance dyeing quality, cotton samples were treated with Sera Fast GMX (a cationic agent) before they were dyed with indigo carmine. The influence of dyeing parameters (i.e., indigo carmine concentration, dyeing temperature, dyeing duration, and sodium carbonate concentration) on the evolution of the color strength (K/S) was studied. A response surface design was employed to optimize this unconventional dyeing process. The addition of salt to the dye bath appeared to improve both color strength and fastness properties. Finally, the effect of treating cationized cotton samples with microwave radiations was investigated. The results showed that exposure to microwave radiation for 5 min resulted in improvements in dyeing quality.

The paper focuses on the competitive influence of SO₂ and HCl during their removal from flue gas by sodium bicarbonate. The experimental investigation was conducted at a unique combination of conditions: the experiments were conducted on a large scale, with real flue gas, and the removal of SO₂ and HCl was studied simultaneously. The aim was to ensure that experimental conditions are reasonably realistic and therefore transferable to practice. The results from experiments at various temperatures within the range from 170 to 255 °C did not indicate a significant influence of temperature. The sorbent conversion varied significantly with the lowest achieved conversion of 26% and the highest conversion of 85%. There was a clear trend showing that higher concentrations of HCl make it more difficult to achieve the selected target concentration of SO₂ in clean flue gas, suggesting the preferred reaction of formed sodium carbonate with HCl. The influence of HCl on the removal of SO₂ was quantified and is presented in the form of regression models. The found regressors were the initial concentrations of HCl and SO₂ in raw flue gas and the target concentration of SO₂ in the clean flue gas. The regression models are in good agreement with the experimental data and can be used for the prediction of the behavior of a flue gas treatment system or its optimization.

We investigated the discharge characteristics, parameters, water content, and mechanism of liquefying biomass by plasma electrolysis under alkaline conditions. Compared with the liquefaction of sawdust under acidic conditions, the discharge changed from corona to spark discharge, the liquefaction time was a little longer (8 min), and the pondus Hydrogenii (pH) of the bio-oil was 7.54 under sodium hydroxide catalyst. We identified the optimal parameters for sawdust liquefaction by sodium hydroxide, sodium carbonate, and sodium bicarbonate using a single factor method and found that the optimal parameters for sodium hydroxide and carbonate were quite different, apparently because they have different liquefaction mechanisms. When the water content increased, the liquefaction rate remained constant, so the water content prolonged the treatment time but did not affect the liquefaction rate or product quality. To analyze the universality of liquefied cellulose biomass under alkaline conditions, corn cob, rice straw, and cotton were liquefied separately. We found that the liquefaction time increased significantly with an increase in cellulose content. Notably, plasma electrolytic liquefaction efficiently heated the solution and effectively catalyzed the liquefaction of biomass with high energy efficiency, making this a promising biomass conversion technology.

Carbonate is the main anionic impurity in alumina produced by the Bayer process. The phase composition, morphology, and precipitation activity of desilication products (DSPs) precipitated at 245°C in sodium aluminate solution with different carbonate concentrations have been investigated by x-ray diffraction (XRD) and scanning electron microscopy–energy-dispersive x-ray spectroscopy (SEM–EDS) methods. The crystalline DSPs without carbonate are composed of zeolite, sodalite, and hydroxy-sodalite, but only zeolite and cancrinite precipitate in the presence of carbonate. Increasing the carbonate concentration promotes the precipitation of cancrinite but reduces the crystallinity of various DSPs. The cell parameters and the Na2O/Al2O3 ratios of DSPs are significantly increased because of the entry of sodium carbonate during crystallization, especially for the cancrinite. The morphology of various DSPs is greatly changed by the carbonate. The amorphous phase content and precipitation activity of DSPs increase with increasing carbonate concentration. This contributes to the effective removal of carbonate from sodium aluminate solution by controlling the desilication process.

The requirements for using noncyanide imitation gold plating as decorative electroplating are increasing; thus, continuously improving the quality of the coating of the imitation gold plating and optimizing the coating process have become the current priority. In this experiment, hydroxyethylidene diphosphonic acid (HEDP) was used as the main complexing agent; CuSO4·5H2O, ZnSO4·7H2O, and NaSnO3·3H2O were the main salts; and NaOH and sodium carbonate were used as the buffers to prepare the electroplating solution. Using sodium citrate (SC), sodium potassium tartrate (SS), sodium gluconate (SG), and glycerol (Gl) as four additives, the effects of the number of carboxyl groups on the properties of a Cu-Zn-Sn alloy coating were compared. The electrochemical analysis showed that Cu-Zn-Sn alloy codeposition occurred at -0.50 Vvs.Hg|HgO. The scanning electron microscopy (SEM) results showed that the grain size of the coatings obtained with carboxyl-containing additives was more uniform than that obtained with the electroplating solution without additives. The X-ray fluorescence spectrometry (XRF) analysis revealed that the composition of the Cu-Zn-Sn alloy coating obtained by using SC as an additive in the electroplating solution was 89.75 wt% Cu, 9.61 wt% Zn, and 0.64 wt% Sn, and the color of the coating was golden yellow. The X-ray diffraction (XRD) pattern showed that the coating was a mixture of Cu, Cu5Zn8, CuSn, Cu6Sn5, and CuZn phases. The analysis of the electroplating solution by UV, IR, and NMR spectroscopy methods indicates that the additives improve the coating by affecting the complexation reaction of metal ions. These results can provide technical guidance for developing Cu-Zn-Sn ternary alloy electrodeposition technology with the new cyanide-free HEDP alkaline electroplating system.

In the present study, bio-oil and biochar have been produced from microwave-assisted catalytic pyrolysis of corn stover (CS). The effects of microwave power (MWP) and mixing of sodium carbonate as a catalyst at different ratios have been examined. Both MWP and the catalyst improved the heating and increased the maximum temperatures of pyrolysis process. Rise in MWP increased the gas yield but decreased the biochar yield, while the bio-oil yield was not significantly affected. The use of catalyst increased the bio-oil yield and enhanced its properties. Increase in the ratios of catalyst from 10% to 30%, did not contribute a significant effect either on the yield or on the properties of the products. The water content in bio-oil was found to be in the range of 53.09–73.79%, while the minimum viscosity was observed to be 3.31 mPa s. The maximum higher heating value (HHV) of bio-oil and biochar were 13.17 MJ/kg and 29.77 MJ/kg respectively. The bio-oil samples were characterized chemically by a gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FTIR). Most of the chemical group compounds in the bio-oil were identified to be alcohol, phenols, alkynes, acids, and aromatic. The net energy recovery from the raw CS was in the range of 28.29–42.97%.

According to the Chinese traditional black jelly production process, a critical step to ensure the quality of jelly is to add alkali to it. In this study, the effects of sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) on the pasting, rheological, textural, and structural properties of sweet potato starch (SPS)-Mesona chinensis Benth polysaccharide (MCP) gels were evaluated. Adding Na2CO3 at low concentration reduced the final viscosity (FV) of SPS-MCP gels, whereas adding it at a high concentration increased the FV. Adding NaHCO3 can increase the FV of SPS-MCP gels in a concentration-dependent manner. Rheological results indicated that adding NaHCO3 at a low concentration decreased the storage modulus of SPS-MCP gels, whereas adding it at a high concentration increased the storage modulus. The storage modulus of SPS-MCP gels increased with increasing concentration of NaHCO3. The addition of Na2CO3 and NaHCO3 improved the textural properties of SPS-MCP gels and decreased the water mobility. Infrared results indicated that adding alkali can enhance the hydrogen bonding between SPS and MCP. Scanning electron microscopy results suggested that alkali can reduce the size of gels, and make the structure more compact.

Lithium carbonate (Li2CO3) was synthesised by adding sodium (Na) and magnesium (Mg) ions into a lithium chloride solution at different concentrations, followed by the addition of an appropriate sodium carbonate solution. Then, the morphology, purity and particle size of Li2CO3 crystals were investigated. The Na and Mg ions had negligible and remarkable effects, respectively, on the product purity; however they both greatly influenced its morphology. Their effects on the nucleation and growth rates, the radial distribution function and the diffusion behaviour of the synthesised Li2CO3 were investigated via molecular dynamics methods; the Na ions slowed down the crystal nucleation and growth rates, while the Mg ions accelerated them. Moreover, the Mg ions rendered the system short-range ordered and long-range disordered and also increased the diffusion coefficient. The results of this study showed that Mg ions are one of the most important factors influencing the purity and yield of Li2CO3.

The present study reports the partial purification and characterisation of a novel xylanase from Bacillus subtilis subsp. subtilis JJBS250 followed by its applicability in the saccharification of rice straw. Bacterial xylanase was partially purified by gel filtration chromatography using Sephadax G-50 matrix that displayed optimal activity at 60 °C and pH 7.0 with half-life values of 1420 and 718 min at 60 °C and 80 °C, respectively. Bacterial xylanase showed high tolerance to ethanol with Km and Vmax values of 1.62 mg/ml and 23.92 U/ml, respectively, for beechwood xylan. Maximum amount of reducing sugars was obtained from sodium carbonate pretreated rice straw (151.65 mg/g substrate) as compared to untreated biomass (90.49 mg/g substrate) using 20 U/g enzyme dose at 60 °C and pH 7.0 after 48 h. Furthermore, the saccharification of pretreated rice straw was improved by synergistic action of bacterial and fungal xylanases. Analysis of rice straw using scanning electron microscopy (SEM), x-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy clearly showed the morphological changes and delignification in rice straw after pretreatment. Bacterial xylanase exhibiting novel properties including ethanol tolerance and high thermostability is highly suitable for the production of second generation biofuels in simultaneous saccharification and fermentation process using lignocellulosic substrates.

Hydrogen sulphide is a toxic gas often present in coal seams and seriously threatens the lives and health of underground workers in coal mines. In this study, we theoretically modelled hydrogen sulphide generation in extremely thick underground coal mines with the +575 level #45 coal seam of Wudong Coal Mine as an example and obtained the on-site hydrogen sulphide emission pattern and spatial distribution features by combining field measurements and computational fluid dynamics simulation. The results showed that hydrogen sulphide mainly exists in the coal porous system in an adsorbed state. Because hydrogen sulphide has a molecular weight greater than the average molecular weight of air molecules, its concentration decreases with the increase of altitude to the bottom plate. When mining the upper stratified coal stratum, it diffuses widely in the working space; while when mining the lower coal stratum, it mainly concentrates at the bottom of the working face. Based on these analyses, on-site treatments were carried out using mixtures with different concentrations of sodium carbonate and sodium bicarbonate. In addition, different combinations of catalysts as well as type A and type B wetting agents were also tested. Eventually, a neutral KXL-I absorbent was developed, and the process of preinjecting absorbent and spraying absorbent was designed. The results showed that the newly developed KXL-I absorbent has high hydrogen sulphide absorption ability and is suitable for use as an absorbent in Wudong Coal Mine; preinjecting and spraying the absorbent can effectively prevent hydrogen sulphide disasters in the +575 level #45 coal seam in Wudong Coal Mine with the optimal final concentration of 0.9% and the absorption rate of 87% at the shearer of 66.6% at the support. Overall, our study provides valuable information for the prevention and control of hydrogen sulphide disasters in coal mines.

2-Amino-5-mercapto-1,3,4-thiadiazole (M1) was prepared by the cyclization of thiosemicarbazide with carbon disulfide and anhydrous sodium carbonate in ethanol. The compound (M1) was used as precursor to react with different aromatic aldehydes to yield hydrazones (M2-M4). Thereafter, hydrazones (M2-M4) is reacted with chloro acetyl chloride to obtain 5-(sub. benzylidene) amino]-2-thioacetyl chloride-1,3,4-thiadiazole compounds (M5–M7). The compounds (M8–M10) and (M11–M13) were synthesized by the reaction of compounds (M5–M7) with benzotriazole or Indole, respectively. All the synthesized compounds were identified according to their physical properties, spectroscopic data (FT-IR). At the same time, some of these prepared compounds were identified by the use of 1H NMR spectroscopy. In addition to the systematic identification of some active functional groups in these compounds. Biological activity for some of the synthesized compounds was evaluated against two types of bacterial and two types of fungal.

Sodium carbonate is a material that is very good sorbent of carbon dioxide from the atmosphere, and it is a reason of it is increasing importance in environmental protection. In order to improve it is sorption characteristics, activation of Na2CO3 was performed by mechanochemical procedure and monitoring of changes during the relaxation time. This research is based on differential thermal analysis with thermogravimetry, in order to determine the changes that occurred on the activated samples during the relaxation period under controlled conditions. Sodium carbonate was activated for 2 and 7 minutes in a vibro mill, and then the activated samples were deposited in at room temperature and atmosphere of carbon dioxide at a humidity of 95% for 96h.

In this study, we report on the synthesis and evaluation of a sodium, magnesium, and aluminum (Na-Mg-Al) layered double hydroxide (LDH) based sorbent for hydrogen chloride (HCl) removal at concentrations found in lignocellulosic biomass derived syngas. The LDH was synthesized by a spontaneous self-assembly method and further calcined at 700 °C to produce a mixed metal oxide sorbent that we evaluated in the hot gas cleanup of hydrogen chloride at 100 parts per million. The performance of this sorbent was evaluated in a fixed bed reactor from 400 to 600 °C against that of a commercial magnesium and aluminum LDH (ComLDH) material that does not contain sodium in the matrix as well as two other commercial sorbents, sodium carbonate (Na2CO3) and sodium aluminate (NaAlO2). Our Na-Mg-Al LDH is thermally stable in the hot gas cleanup temperature range. During fixed bed experiments, our calcined LDH mixed metal oxide was effective in reducing hydrogen chloride’s concentration below the breakthrough concentration of 1 ppm from 400 to 600 °C for more than 14 h. The better performance of our calcined LDH compared to calcined commercial LDH supported our hypothesis that sodium incorporation in the LDH matrix enhances HCl sorption. Based on comparison against the commercial Na-based sorbents, the following rankings by temperature observed: LDH > NaAlO2 > Na2CO3 at 400 °C; LDH = NaAlO2 > Na2CO3 at 500 °C; and Na2CO3 = NaAlO2 = LDH at 600 °C.

The current study was conducted to assess the groundwater for irrigation purposes in the village of Ein Al-Husaan in Talafar district in Nineveh Governorate, based on the Water Quality Index (WQI) as an effective method for determining the suitability of water for irrigation. Ten wells were selected for five months with a sample site for each month and some physical, chemical, and biological tests were performed that include: pH, EC25, bicarbonate, chloride, and F. colif. In addition to calculating the irrigation coefficients of % Na, SAR (Sodium Adsorption Ratio), KR (Kelly Ratio), MAR (Magnesium Adsorption Ratio), RSC (Residual Sodium Carbonate), PI (Permeability index), and PS (Potenial Salinity), the results showed that the PS was higher than the permissible limits for irrigation as a result of the passage of water with the rocks of evaporators that contain sulfates, while the water quality index ranged between (54.83–61.58). This indicates that all the water from wells was of good quality according to the classification.

The co-presence of geopolymers and cellulose in clay-based materials could improve their performances. Thus, cured NaOH-activated heated clay-cellulose (up to 10 mass%) composites were prepared, and their microstructural characteristics were investigated. Moreover, the effect of waste glass addition on the composites characteristics was evaluated. The results showed that zeolite (chabazite) and sodium carbonate were formed from metakaolin and by carbonation respectively, and the zeolization process slowed down after 5 days of curing because of ions immobilization. The coating of metakaolin particles by the amorphous cellulose II-Na formed reduced drastically the formation of zeolite. The presence of cellulose II-Na resulted in the porosity decrease, and consequently the mechanical strength and density enhanced. The results also showed that the kinetics of water absorption by the composites followed the pseudo-first order equation, and the rate constant was found to be 4.3 × 10−3 s−1. Moreover, the reinforcing effect of the cellulose fibbers was annihilated by the formation of glass derivatives. Resumen: La co-presencia de geopolímeros y celulosa en materiales a base de arcilla podría mejorar sus rendimientos. De este modo, se prepararon compuestos de arcilla-celulosa calentada activados con NaOH (hasta un 10% en masa) y se investigaron sus características microestructurales. Además, se evaluó el efecto de la adición de residuos de vidrio sobre las características de los composites. Los resultados mostraron que la zeolita (chabasita) y el carbonato de sodio se formaron a partir de metacaolín y por carbonación, respectivamente, y el proceso de zeolización se ralentizó después de 5 días de curado debido a la inmovilización de iones. El recubrimiento de partículas de metacaolín por la celulosa amorfa II-Na formada redujo drásticamente la formación de zeolita. La presencia de celulosa II-Na resultó en la disminución de la porosidad y, en consecuencia, la resistencia mecánica y la densidad aumentaron. Los resultados también mostraron que la cinética de la absorción de agua por los compuestos siguió la ecuación de pseudo primer orden, y se encontró que la constante de velocidad era 4,3 × 10−3 s−1. Además, el efecto de refuerzo de las fibras de celulosa fue aniquilado por la formación de derivados de vidrio.

An electrosynthesis is presented to transform CO2 into an unusual nano and micron dimensioned morphology of carbon, termed Carbon Nano-Scaffold (CNS) with wide a range of high surface area graphene potential usages including batteries, supercapacitors, compression devices, electromagnetic wave shielding and sensors. Current CNS value is over $323 per milligram. The morphology consists of a series of asymmetric 20 to 100 nm thick flat multilayer graphene platelets 2 to 20 µm long orthogonally oriented in a 3D neoplasticism-like geometry, and appears distinct from the honeycomb, foam, or balsa wood cell structures previously attributed to carbon scaffolds. The CNS synthesis splits CO2 by electrolysis in molten carbonate and has a carbon negative footprint. It is observed that transition metal nucleated, high yield growth of carbon nanotubes (CNTs) is inhibited in electrolytes containing over 50 wt% of sodium or 30 wt% of potassium carbonate, or at electrolysis temperatures less than 700 °C. Here, it is found that a lower temperature of synthesis, lower concentrations of lithium carbonate, and higher current density promotes CNS growth while suppressing CNT growth. Electrolyte conditions of 50 wt% sodium carbonate relative to lithium carbonate at an electrolysis temperature of 670 °C produced over 80% of the CNS desired product at 85% faradaic efficiency with a Muntz brass cathode and an Inconel anode.

Bu çalışmada, kalsiyum karbonatın polimorfik faz dönüşümü katkı maddesi olarak kullanılan prolin varlığında incelenmiştir. Deneyler 1L kapasiteli çift ceketli kristalizörde, 30 C sıcaklık ve pH 8,5’da yürütülmüştür. 50 ve 100 ppm olmak üzere iki farklı katkı konsantrasyonunda deneyler gerçekleştirilmiştir. Reaktan olarak kalsiyum klorür dihidrat ve sodyum karbonat kullanılmıştır. Deney süresince belirli zaman aralıklarında numuneler alınarak, kristallerin yapısı, fonksiyonel grupları, morfolojisi, tane boyutları ve yüzey yüklerinin değişimi belirlenmiştir. XRD ve FTIR analiz sonuçları, kalsiyum karbonat kristallerinin prolin varlığında kalsit formundan vaterit formuna dönüştüğünü göstermiştir. SEM görüntüleri saf ortamda üretilen kalsit kristallerinin kübik formda olduğunu buna karşın prolin varlığında kristallerin yuvarlak görünümlü vaterit morfolojisine sahip kristallere dönüştüğünü göstermiştir. Ayrıca, prolinin kalsiyum karbonat kristallerinin yüzey alanına ve yüzey yüküne olan etkisi BET analizi ve zeta potansiyeli ölçümleri yapılarak belirlenmiştir. Saf ortamda üretilen kalsit kristallerinin BET yüzey alanı ve zeta potansiyeli değeri sırasıyla 0,7 m2/g ve –8,0 ± 2,1 mV olarak ölçülmüştür. Buna karşın, 100 ppm prolin varlığında kristallerin BET yüzey alanı 3.7 m2/g’a yükselmiş ve prolinin kristallerin yüzeyine fiziksel olarak adsorplanmasından dolayı zeta potansiyel değerleri daha negatif (–24,0 ± 2,6 mV) hale gelmiştir. Sonuç olarak, katkı maddesi olarak kullanılan prolinin kalsiyum karbonatın hem fiziksel hem de morfolojik özelliklerini önemli ölçüde değiştirdiği gösterilmiş ve farklı formlarda kalsiyum karbonat kristallerinin üretilmesine imkân sağlayacağı tespit edilmiştir., In this study, the polymorphic phase transformation of calcium carbonate was analyzed in the presence of proline used as an additive. The experiments were carried out in a 1-litre double-jacketed crystallizerat 30 C and pH 8.5. The experiments were performed at two different concentrations of 50 and 100 ppm. Calcium chloride dihydrate and sodium carbonate were used as the reactants. During the polymorphic transformation process, the samples were withdrawn from the crystallizer at regular time intervals and the structure, functional group, morphology, particle size and surface charges of the calcium carbonate were determined as a function of the time. XRD and FTIR results showed that calcium carbonate crystals transformed from calcite to vaterite structures in the presence of proline. SEM images indicated that the calcium carbonate crystals prepared in pure media was cubic shaped crystals and the morphology transformed into spherical like vaterite crystals in the presence of proline. Moreover, the effects of proline on the surface area and surface charge of calcium carbonate were investigated by BET and zeta potential analysis. BET surface area and zeta potential for calcite crystals prepared in pure media were 0.7 m2/ g and - 8.0 ± 2.1 mV, respectively. By the addition of proline to the crystallization media, BET surface area increased to 3.7 m2/g, and the surface became more negative (- 24.0 ± 2.6 mV).

This study aimed to compare the time-related corrosive resistance in different corrosive solution environments after sintering of zirconia with different crystal structures. The zirconia samples were produced in pellet form as 12.7 × 3 mm. To determine the time-related corrosion resistance of the sintered samples in sodium carbonate (Na2 CO3 ), sodium chloride (NaCl), and citric acid (C6 H8 O7 ) solutions, the weights were measured at baseline then on the first and fifth days and the microhardness values were calculated. For the evaluation of surface appearance, images were obtained with a scanning electron microscope. The baseline microhardness values of the groups with 3 and 10 mol% yttria-stabilized zirconia samples were found to be 1,064 VHN and 1,079 VHN, respectively. The microhardness values of the groups with 3 mol% yttria-stabilized zirconia samples immersed in Na2 CO3 1d (1,010 VHN) and 5d (1,060 VHN), and NaCl (1d (1,010 VHN) and 5d (1,055 VHN) were found to be affected more. The microhardness values of the sample group (1,064 VHN) with 10 mol% yttria doped zirconia which was left for 5 days in citric acid were found to be lower than the sample group (1,120 VHN) with 3 mol% yttria added. C6 H8 O7 was seen to have a greater corrosive effect with increased yttria content and the microhardness value decreased. With longer duration of the samples of all the groups in C6 H8 O7 , NaCl, and Na2 CO3 solutions, the surface characteristics of the samples were affected negatively. With prolonged immersion in the corrosive solutions, the resistance to the corrosion causing the changes in the surface topography of the samples was seen to decrease.

Applying spent lithium iron phosphate battery as raw material, valuable metals in spent lithium ion battery were effectively recovered through separation of active material, selective leaching, and stepwise chemical precipitation. Using stoichiometric Na2S2O8 as an oxidant and adding low-concentration H2SO4 as a leaching agent was proposed. This route was totally different from the conventional methods of dissolving all of the elements into solution by using excess mineral acid. When experiments were done under optimal conditions (Na2S2O8-to-Li molar ratio 0.45, 0.30 mol/L H2SO4, 60 °C, 1.5 h), leaching efficiencies of 97.53% for Li+, 1.39% for Fe3+, and 2.58% for PO43− were recorded. FePO4 was then recovered by a precipitation method from the leachate while maintaining the pH at 2.0. The mother liquor was concentrated and maintained at a temperature of approximately 100 °C, and then a saturated sodium carbonate solution was added to precipitate Li2CO3. The lithium recovery yield was close to 80%.

It was shown by ATR FTIR, XRD and 11B MAS NMR methods that increasing contents of sodium polyborate and sodium carbonate impurities were formed in solid sodium borohydride upon its storage and contact with the air. To increase the NaBH4 purity after storage, it was re-crystallized in diglyme using the well-known Brown's procedure. The purification efficiency was further improved by ammonia treatment during NaBH4 dissolution. It was found that the advantages of using the gaseous ammonia consisted in an increased NaBH4 solubility in diglyme and a more efficient reduction in the content of impurities to form a material consisting of uniform highly dispersed particles of the hydride having a regular cubic shape. It was found for the process of catalytic hydrolysis of NaBH4 that the rate of hydrogen generation and its yield increased with the decreasing content of impurities. These results demonstrate the importance of investigations aimed at improving the existing methods of NaBH4 purification and creating new ones.

Manganese is one of the most difficult elements to be recovered from its respective solutions, due to its high solubility in both acid and neutral conditions. However, metal carbonate precipitation...

Currently, the urgent problem is the secondary use of distillation liquid - a waste product from the production of sodium carbonate, which is an aqueous solution containing about 10 % calcium chloride and a small amount of other salts. It is proposed to use a solution based on a distiller liquid as a coolant in a heat exchange system in the production of soda. The introduction of potassium dichromate into the system creates an inhibitory effect and prevents pipe corrosion. To study phase equilibria in the CaCl2 - K2Cr2O7 - H2O system, state diagrams were constructed at temperatures of 20, 3, and -7°C. With decreasing temperature, the homogeneous region noticeably decreases and shifts to the CaCl2 - H2O axis. The eutectic point is limited to a very narrow area in which the weight fraction of potassium dichromate does not exceed 3%.Using the Skrynemakers method, it was found that in a region with a calcium chloride content of less than 40 %, potassium dichromate crystallizes. For the region adjacent to the apex of calcium chloride, it is impossible to establish the composition of the solid phase and the boundaries of its crystallization using the Skrynemakers method. This is due to the fact that the binary system CaCl2 - K2Cr2O7 is a ternary reciprocal system K +, Ca2 + Cl-, Cr2O72- . In this area, the formation of solid solutions or compounds based on the binary system K2Cr2O7 - CaCr2O7 is supposed. For the temperature range from -7 ?С to 50 ?С, the refrigerant composition was proposed: 3 % K2Cr2O7 - 10.2 % CaCl2 - 86.8 % H2O. In the temperature range from 20 ?С to 60 ?С, the composition of the solution is: 6 % K2Cr2O7 – 10 % CaCl2 – 84 % H2O.

We evaluated the performance of a resorcinol–formaldehyde (RF) hydrogel as an adsorbent for removing aqueous cesium ions (Cs+), by synthesizing cylindrical pellets of RF gels under different molar ratios (R/C) between resorcinol (R) and sodium carbonate (C) as the catalyst for the sol–gel polycondensation in the range from 2.5 to 400. The RF gel prepared at R/C = 2.5, containing the greatest amount of sodium ion (Na+), had the greatest Cs+ adsorption amount (0.660 mmol g−1), because Cs+ could be adsorbed on the network structure in the gel through exchange with Na+ at an equal molar ratio, but with the smallest effective diffusion coefficient of Cs+ (1.45 × 10–12 m2 s−1). Kinetic analyses based on the Dryden–Kay and intra-particle diffusion models revealed that the diffusivity of Cs+ in the RF gel depended strongly on the density of the network structure, which can be controlled by varying the R/C ratio.

Scaling caused by sodium carbonate and sodium sulphate salts is a common problem during black liquor evaporation and mills currently have no proper tools to monitor or follow it up. The method proposed enables automatic evaluation of scaling rates and behaviours, together with washing performance, by using measurements that are already available at most mills, such as the boiling point elevation and the overall heat transfer coefficient. The method identified the scaling correctly in most cases, normally >90 %, although fast and sudden scaling proved to be challenging; its performance was also dependent on the quality of the data used. Historical data from three mills was evaluated and it was found that the scaling rate generally increased at higher concentrations of black liquor: one of the mills had almost no scaling below 70 % dry solids content. Another mill, however, deviated from this trend and had significant problems with fast and sudden scaling in one effect at around 60 % dry solids content. The correlation of process parameters revealed that this scaling was triggered, to a large extent, by the absence of tall oil brine, which is a side stream from the production of tall oil that is normally fed to the evaporators.

Batch biosorption studies of methyl orange (MO) dye removal using newly formed micro-grooved chitosan (GCS) gel beads were synthesized by using NaOH-based gelling solution supplemented with Na2CO3 at different volume ratios (v/v) of NaOH-to-Na2CO3. The newly formed GCS gel beads with the best adsorption capacity corresponding to the volume ratio of NaOH–Na2CO3 were selected as potential biosorbent in subsequent adsorption studies. Taguchi orthogonal array of L9 (33) was adopted to investigate the simultaneous variations of three controlling factors, namely: pH of MO (pH 3, 7, 11), initial concentration of MO (30 ppm, 50 ppm, 90 ppm) and new GCS adsorbent dosage (0.35 g, 0.5 g, 1 g). The dye removal percentage (removal%) was found to be between (30.09 ± 4.66)% and (98.15 ± 0.23)%. The average uptake capacity (qe) of MO by GCS adsorbent was varied from (1.22 ± 0.03)mg/g to (9.14 ± 0.00)mg/g. The highest mean of S/N ratio was selected to obtain maximum adsorption performance. The optimum operating condition for the highest removal% was achieved at pH 3 with 1 g of adsorbent dosage and 30 ppm of MO concentration, whereas the maximum qe was identified at pH 3 with adsorbent dose of 0.35 g and 90 ppm of MO concentration. The morphology of GCS gel beads before and after adsorption was analysed using field emission scanning electron microscopy (FESEM). The adsorption results were best fit to two parameter Harkins–Jura isotherm (R2 = 0.9979). This affirmed that the adsorption of MO dye solution by GCS gel beads was a multilayer adsorption.

The use of sodium carbonate as an alkali activator for slag to produce alkali-activated slag is promising due to its sustainable, economic and user-friendly properties. However, the lower early age performance of composites made with such binder has limited its use especially in applications where higher early age is required. Hence, in order to propel the application of this sustainable binder, it is imperative to find ways in which the early age performance can be enhanced without having a detrimental effect on later age performance. One of the effective and sustainable ways to enhance the early age strength of sodium carbonate activated slag is by incorporation of various additives as partial replacement of sodium carbonate on/and slag. In order to propel more application of sodium carbonate slag for various applications, this current study was undertaken. In this paper, an overview of the types of various additives that can be used to enhance the early age compressive strength of sodium carbonate activated slag composites was discussed. The mechanism and dosage of each of the additives were briefly discussed alongside the limitation and advantages of the additives. Findings from this overview showed that the early age compressive strength of sodium carbonate activated slag can be enhanced with the use of additives such as calcium oxide, calcium hydroxide, Portland cement, sodium hydroxide and sodium silicate.

Thermal decomposition and phase transformation for the mixture of Bayan Obo rare earth concentrate (BORC) and sodium carbonate (Na2CO3) roasted at different temperatures with weight ratio of 100:20 were studied in detail in our study. The aim of our study is to reveal the nature of roasting reaction between BORC and Na2CO3 and thus providing a new method for processing BORC. The results indicate that BORC can be decomposed completely with Na2CO3 at around 600 °C after 3 h. During the calcination process, Ce0.5Nd0.5O1.75, NaF, Na3PO4, and a rare earth double phosphate phase Na3RE(PO4)2 are formed after the decomposition of BORC with Na2CO3. In addition, the thermal decomposition mechanism is determined in the paper. Based on these facts, a clean technique processing BORC was developed. And a CeF3 powder, whose composition was measured and stability was also evaluated, was obtained for some potential application from the new technique. This research is of significance in terms of the Na2CO3-roasting BORC solid reaction study and sheds a light on a potential clean technique for BORC.

The aim of this study is to present the design, optimization and modelling of a chemical recovery system for a novel CS2-free viscose-type process that entails dissolution of pre-treated dissolving pulp in a continuous-flow reactor in cold alkali and wet spinning of cellulose in sodium carbonate solutions. Technologies already known to other industries for the recovery and reuse of chemicals, such as causticizing, recalcination, recarbonization and freeze-separation, were used. Chemical equilibria simulations were performed with OLI Studio 9.5, with the purpose to select experimental conditions which avoid undesired precipitations in each unit operation. Synthetic solutions mimicking the spent coagulation liquor were used in the laboratorial experiments. The proposed chemical recovery system was shown to be technically feasible and reduce chemical make-ups to a minimum of 45 kg/ton of NaOH and 4 kg/ton of H2SO4. Small amounts of Zn are expected to precipitate during recarbonization of the coagulation liquor at 30 °C and causticizing at 98 °C. Thus, a filter for ZnO particles should be included in the design of the recarbonization unit and a continuous purge of lime mud and input of fresh lime make-up should be needed to keep burnt lime availability at an acceptable level. Overall, the results presented in this study portray a solution to reduce operating costs and the environmental impact of novel viscose-type processes with alkaline spin dopes and wet spinning of cellulose in sodium carbonate solutions.

Sodium titanate nanotubes (STN) modified by the addition of sodium carbonate (3–10 wt. %) were tested as catalysts for the transesterification of soybean oil with methanol giving good results. Prepared catalysts were characterized by N2 physisorption, X-ray diffraction, FT-IR, temperature-programmed desorption of CO2, scanning and transmission electron microscopy. The STN catalysts modified with sodium carbonate were significantly more active in the transesterification reaction than the reference catalyst containing 5 wt. % of Na2CO3 on alumina. The most active catalyst, STN with 10 wt. % of Na2CO3, resulted in the 97% yield of methyl esters at a short reaction time (30 min) in mild conditions (80 °C). High activity of the prepared catalysts was attributed to a synergetic effect between the support and the deposited sodium carbonate leading to a noticeable increase in the amount of strong basic sites able to generate methoxide anions required for the transformation of triglycerides to methyl esters. According to the FT-IR characterization, the above synergy was attributed to the presence of different types of carbonate species in the alumina and STN-supported catalysts. Upon reutilization, Na2CO3-containing STN catalysts showed a decrease in their activity due to leaching of the active phase in the reaction media.

A method for the preparation of extra-pure Na2CO3 powder has been developed. The method is based on a fractional crystallization of Na2CO3 from its saturated solutions and its conversion into sodium formate, followed by a melt crystallization. To obtain the final product Na2CO3, the recrystallized sodium formate was thermally decomposed. The contents of Th and U in the purified powder were below 10 ppt, the concentrations of Mn, Co, Ba, and Pb were not above 3 ppb, the concentrations of Cu and Sr were on the level of tens of ppb, and the K concentration was about 200 ppb. The ICP-MS analysis showed that the purity of the obtained powder significantly surpasses that for commercial products in 99.997 and 99.999% purity grades. The sodium carbonate powder thus obtained is going to be used as initial material for growing scintillation single crystals in experiments searching for the neutrinoless double beta decay (0νββ) or dark matter.

This research work analysed groundwater quality in Al-Kasik district northeastern of Mosul city, Iraq. The area is agricultural land which uses well water for livestock watering and irrigation. Groundwater samples were collected from five wells during dry season to determine the following parameters: pH, electrical conductivity (EC25,), anions, cations, soluble sodium percentage (SSP), sodium absorption ratio (SAR), residual sodium carbonate (RSC) and potential salinity, permeability index and Kelly Ratio, IWQ index model was applied for the evaluation. The well water samples were evaluated for agricultural uses according to universal standard classification. Results indicated that most of the measured parameters were high especially electrical conductivity (5369μS/cm), with P. Salinity, Sodium, Calcium and Sulfate ions having 30.7, 15.3, 34.0, 29.3 meq. l-1 respectively. These have an effect on water quality hence considered being of very high salinity (C4) according to United State Salinity Laboratory (USSL). According to the water quality index (IWQ index), the analyzed water was specified as low restriction (LR) to Severe restriction (SR) for irrigation. Keywords: Water Quality; Groundwater; Quality Index; Water Quality Models.

In order to obtain the modified surface structure of the 20Cr2Ni4A steel plasma electrolytic hardening (PEH) method was used. The surface hardening process was conducted in the aqueous electrolyte solution of 20% sodium carbonate and 20% urea. The sample consists of a ferritic-pearlitic structure, i.e. the part retains its viscous core, and the surface layer contains carbide particles. Hardening process induces martensite transformation and creation of carbide particles in the surface layer. The presence of carbide particles in the surface layers has a positive effect on the tribo-mechanical performance. Hardened structure 600 μm long was obtained with hardness increase up to 520 HV and 2.5 times higher wear resistance. Tribological test results showed the difference of the coefficient of friction as a function of surface roughness determined by plasma-electrolytic hardening process.

The main purpose of the work reported herein is to use kaolin to produce one-part alkali-activated cement. Thermal activation was performed on kaolin in the presence of alkalis (calcium oxide, sodium silicate, and sodium carbonate). Optimization experimental investigations were undertaken with selected alkalis to maximize the mechanical properties as well as minimize the cost of the resultant alkali-activated cement. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) test techniques were used to get insight into the binder chemical phases and their microstructure. The results showed that the optimal formulation for the alkali-activated kaolin cement developed consists of 62.5 wt.% kaolin, 30 wt.% calcium oxide, 5 wt.% sodium carbonate and 2.5 wt.% sodium silicate. The 7-day compressive strength at heat and room-curing temperatures reached 19.83 and 16.47 MPa, respectively. The competitive merits of the kaolin-based cement assessed against Portland cement considering the raw materials and production processing contributions to carbon footprint, cost, and energy content. The carbon footprint of the alkali-activated kaolin cement was 70% less than that of Portland cement. The cost and energy content of the alkali-activated kaolin cement was 45% and 70%, respectively, less than those of Portland cement.

This work was an attempt to prepare a new eco-friendly adsorbent for the recovery of uranium from the Egyptian radioactive deposits. So, cellulose/p-toluidine was prepared as a potential sorbent for uranium (VI) in highly alkaline solutions, from a condensation reaction of p-toluene with dialdehyde cellulose which resulting from periodate selective oxidative of cellulose. We have studied the kinetics, isotherm models, and thermodynamic of uranium adsorption from aqueous solutions by dissolved the deposits uranium in sodium carbonate aqueous solution. The effect of adsorption time, and temperature, pH, as well as uranium concentration on adsorption capacity were investigated. The adsorption capacity of uranium by cellulose p-toluidine has been found to attain 80 mg/g. Scanning electron microscopy, X-ray diffractometer, and Fourier transform infrared spectroscopy were used to study the morphological characterization, and chemical structure of the prepared adsorbent. In addition, the computational calculation of dialdehyde cellulose, p-toluidine, and cellulose/p-toluidine by DFT/B3LYP/6-31G (d) basis sets was studied. The adsorption of uranium using cellulose p-toluidine followed fitted with pseudo-second-order reaction as well as Langmuir isotherm. Also, the prepared adsorbent displayed excellent antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, E. coli and Candida albicans.

Drilling additives play a unique role during drilling operations, from aiding in the control of various drilling challenges to successfully enhancing downhole drilling efficiency. pH enhancers are amongst the plethora of additives imported into Nigeria at exorbitant prices to aid in drilling operations. These additives includes NaOH, Na2CO3, Ca (OH)2 etc. These additives are used to improve the mud pH and mitigates drill string corrosion. The high cost of importation of these additives, has warranted the need for product substitution which should take advantage of the locally available resources. This paper evaluated the suitability of locally-sourced Trona, as a mud additive in drilling mud. Trona is known chemically as Sodium Sesquicarbonate or Sodium Hydrogen Carbonate. A distinguishing factor in this research work was the purification of Trona by extracting the compound of interest (Na2CO3) from it using the monohydrate process. The purification method involved crushing and screening of Trona as well as calcination, filtration and evaporation processes. The analysis of the Trona and the extracted product was performed using quantitative analysis and characterization tools such as FTIR and EDX. Further experimentation was carried out to evaluate the effects of the extracted sodium carbonate on the mud pH, rheology, and density of the water-based mud. The results were also compared to the results gotten from the addition of conventional Na2CO to similar mud samples. The extracted Na2CO was observed to increase the pH of the mud samples from 8.73 to 9.52 and the commercial Na2CO increased it from 8.73 to 10 and this value is still in the range of API standard. The pH enhancers from both sources also had effect on the mud rheological properties. This indeed showed that the extracted Na2CO from Trona acted as drilling fluid pH enhancer and hence possess the potential for usage in the industry.

Hydrogeochemical characteristics of Groundwater analyzed in the study area of Coimbatore district by collecting 60 samples from agricultural belt. Groundwater quality for irrigation is determined by several key factors like pH, Electrical conductivity (EC), Total suspended solids (TDS). The cations such as Sodium (Na+), Potassium (K+), Calcium (Ca2+), Magnesium (Mg2+ ) and anions are Hydrocarbon (HCO3), Carbonate (CO3 -), Chlorides (Cl-)and Sulphates (SO4 2-) are tested. The irrigation water quality parameters such as Residual Sodium Carbonate (RSC), Sodium Absorption Ratio (SAR), Chloro Alkali Indices (CA I & CAII), Kelley’s Ratio (KR), Magnesium Hazard (MH), Percent sodium (%Na) and Permeability Index (PI), Soluble sodium Percent (SSP) are computed from the key factors, anions and cations. From the USSL Diagram the samples fall in C2S1, C3S1, C4S1 range. Salinity hazard is too elevated in the study area, all the samples are categorized under high to very high with the values greater than 750 μS/cm. Total dissolved solid in the study area indicated that only 2 locations are unfit for irrigation. SAR and % Na shows that there is no hazard related to irrigation watering. Magnesium hazard in the groundwater is high and indicates 51 sample out of 60 is unsuitable for irrigation. From the study it indicates the groundwater is contaminated with salt content and in most of the area it can be used for irrigation. Keywords: Groundwater, Irrigation water quality, Salinity hazard, Kelley’s ratio, Magnesium hazard

The effect of sodium carbonate (Na2CO3) treatment of short bamboo fibres on mechanical properties and water absorption character of polyester composite is investigated. Treatment time and Na2CO3 co...

The effects of a series of co-catalysts: iron(III)chloride, zinc chloride, sodium borate, acetic acid, oxalic acid, 10% Pd-C, sodium carbonate, and Raney-Ni as well as H2 at 200 psi reductive conditions were studied on the iron(0)-catalyzed hydrothermal liquefaction of switchgrass at 210 °C. The addition 10% (w/w) iron(III)chloride as a co-catalyst in 60% aq. ethanol, without a hydrogen atmosphere enhanced the liquefaction yield from 55.7 ± 1.5 to 67.6 ± 2.5%. The use of Pd/C (5% w/w) and Raney-Ni (5% w/w) as co-catalysts could also enhance the liquefaction yields to 67.0 ± 3.0 and 72.3 ± 1.8% respectively, in reactions carried out under hydrogen atmosphere at 200 psi, in H2O, 210 °C, 24 h. GC-MS analysis of the liquefaction products revealed that C5-C10 range partially oxygenated products are formed and the composition of the liquefaction product depends on the co-catalyst used. The thermogravimetric and FT-IR analysis of liquefaction residues indicated that polysaccharide fraction is mainly liquefied in these iron(0)-catalyzed liquefactions of switchgrass at 210 °C.

The encapsulation of phase change materials (PCMs) as thermal energy storage materials is a big issue. PCM is usually encapsulated to avoid spillage, flammability and its reaction with the surrounding environment to improve its application. In the last decade, various methods have been employed and all kinds of microencapsulated PCM are produced. In this paper, we present a facile route to produce an encapsulated PCM with an organic and inorganic shell. The encapsulated phase change material (PCM) was prepared using a coaxial micro-fluidic system combined with an ionic cross-linking process. The alginate was used as the basic shell and a range of capsules was obtained by modifying the original shell using two inorganic components such as sodium carbonate and sodium silicate. Various samples, each with a different surrounding layer, were prepared by combining alginate calcium (Alg–Ca) as an organic shell with an inorganic component such as alginate calcium carbonate (Alg–CaCO3) and alginate calcium silicate (Alg–CaSiO3). In these experimental works, we have investigated the compatibility and the stability of capsules modified with the inorganic component. The scanning electron microscopy (SEM) technique and optical microscopy were utilized to study the capsule morphology. The chemical composition of the shell was evaluated by Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetry analysis and SEM coupled with the EDX analysis, and the capsule stability was estimated under an accelerated thermal cycling.

Bentonite is the most widely used foundry binder. Most of the iron castings are made in greensand systems which make use of bentonite as a binder. The bentonite used in greensand moulding is usually activated with sodium carbonate to achieve desirable properties. Activation of bentonite is known to improve mould related properties like giving a high wet tensile strength and improving the durability. The practice of activation is more common with calcium bentonite. A number of bentonite deposits tend to remain unbeneficiated due to their low cation exchange capacity (CEC) which are regarded as low quality commercial grade. The primary characteristic that shows the increased activation is the swelling index of the bentonite. This study investigated the influence of rehydration and activation in improving the quality of low commercial grade sodium bentonite. The bentonite samples were activated with sodium carbonate. Rehydration and activation was seen to improve the CEC and swelling index. The increase in CEC and swelling index was however not consistent with the gains in sodium.

Porous alumina bodies, intended for use as heat-insulating refractory materials, were fabricated by a high-temperature evaporation method and characterized. A series of flux systems was used by adding a third component to Na2O–B2O3 glass in addition to boric acid and sodium carbonate. When SiO2 was added as the third component, the primary alumina particles grew anisotropically, forming a plate-like shape, and the house-of-cards structure was self-organized. The anisotropic growth of alumina platelets was promoted by the solid solution of Si4+ ions in the flux on the α-Al2O3 surface. Furthermore, the bonding between the alumina platelets was strengthened by the high-SiO2-concentration flux. Our typical alumina body had a porosity of 71.5%, a compressive strength of 3.7 MPa, a shrinkage rate of 2.6% when reheated at 1700 °C, and a thermal conductivity of 0.24 W m−1•K−1 at 1000 °C. Thus, the present alumina bodies are expected to find application as high-performance heat-insulating refractory materials.